WO2012132387A1 - Electrode material, method for producing same, electrode, secondary battery, and vehicle - Google Patents

Electrode material, method for producing same, electrode, secondary battery, and vehicle Download PDF

Info

Publication number
WO2012132387A1
WO2012132387A1 PCT/JP2012/002074 JP2012002074W WO2012132387A1 WO 2012132387 A1 WO2012132387 A1 WO 2012132387A1 JP 2012002074 W JP2012002074 W JP 2012002074W WO 2012132387 A1 WO2012132387 A1 WO 2012132387A1
Authority
WO
WIPO (PCT)
Prior art keywords
active material
carbon
electrode
sample
negative electrode
Prior art date
Application number
PCT/JP2012/002074
Other languages
French (fr)
Japanese (ja)
Inventor
森口　勇
山田　博俊
幸幾 瓜田
宏隆 曽根
佑介 杉山
村瀬　仁俊
直人 安田
Original Assignee
株式会社豊田自動織機
国立大学法人 長崎大学
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社豊田自動織機, 国立大学法人 長崎大学 filed Critical 株式会社豊田自動織機
Priority to JP2013507168A priority Critical patent/JPWO2012132387A1/en
Publication of WO2012132387A1 publication Critical patent/WO2012132387A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H01M4/1391—Processes of manufacture of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/366—Composites as layered products
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a suitable electrode material for a negative electrode and a positive electrode provided with a surface-coated active material, a manufacturing method thereof, an electrode having these electrode materials, a secondary battery, and a vehicle using the same.
  • lithium (secondary) ion secondary batteries have been widely used as a power source for small electronic devices such as mobile phones and notebook computers with high energy density. Aiming for applications such as power sources for electric vehicles and storage battery systems for natural energy load leveling, it is desired to increase the output and capacity of Li-ion secondary batteries. In particular, in order to apply to a power source for electric vehicles, further increase in capacity of the Li ion secondary battery is desired.
  • the Li ion secondary battery generally includes a negative electrode made of a negative electrode material and a negative electrode current collector, a positive electrode made of a positive electrode material and a positive electrode current collector, a separator, and an electrolyte.
  • a negative electrode active material is used as the negative electrode material. Since the negative electrode active material generally has low electronic conductivity, carbon particles such as acetylene black are mixed as a conductive additive.
  • a negative electrode active material such as graphite, a conductive agent such as acetylene black, and a binder such as polytetofluoroethine (PTFE) and polyvinylidene fluoride resin (PVDF) are used as appropriate solvents.
  • the slurry is made into a slurry, and this slurry is applied to a negative electrode current collector such as a copper foil having a predetermined thickness and dried.
  • a positive electrode active material for example, a positive electrode active material, a conductive agent such as acetylene black, and a binder such as PTFE and PVDF are slurried with an appropriate solvent, and the slurry is made of an aluminum foil having a predetermined thickness. It is applied to a positive electrode current collector such as, and dried.
  • a positive electrode active material for example, a positive electrode active material, a conductive agent such as acetylene black, and a binder such as PTFE and PVDF are slurried with an appropriate solvent, and the slurry is made of an aluminum foil having a predetermined thickness. It is applied to a positive electrode current collector such as, and dried.
  • the negative electrode and the positive electrode are disposed so as to face each other in a battery can, for example.
  • An electrolyte is provided between the positive electrode and the negative electrode.
  • a separator is provided in the approximate center of the electrolyte. It uses for a separator as needed.
  • As the separator polyethylene (PE) or polypropylene (PP) formed into a microporous shape is used.
  • a predetermined electrolytic solution is used as the electrolyte.
  • the carbothermal method is a method in which carbon and positive electrode active material are mixed by ball milling and then heat-treated to generate carbon on the particle surface of the positive electrode active material.
  • carbon (C) adhere to the active material and carbonizing the electrode material as much as possible, it is easy to make electronic contact between the active materials. Thereby, it is possible to reduce the amount of conductive aid while ensuring a certain degree of conductivity.
  • Japanese Patent Application Publication No. 2010-528967 discloses a method for producing nanoparticles coated with carbon and coated with a transition metal oxide.
  • the method for producing nanoparticles includes preparing a liquid mixture containing, as a precursor, an alkoxide of one transition metal, an alcohol, and an excess amount of acetic acid with respect to the transition metal, and the prepared liquid mixture A step of diluting with water to form an aqueous solution, a step of freeze-drying the aqueous solution, and a step of thermally decomposing the lyophilized product obtained in the freeze-drying step under a vacuum or an inert atmosphere to obtain nanoparticles.
  • Nanoparticles contain transition metal elements, carbon elements, and oxygen elements in stoichiometric ratios.
  • Nanoparticles made of an oxide of a transition element selected from (Zn) and coated with amorphous carbon can be produced.
  • group 14 silicon (Si) in the Periodic Table of Elements has a theoretical charge / discharge capacity of 4200 mAh / g, and more than 10 times the graphite (theoretical capacity 372 mAh / g) currently used as a negative electrode material. However, it is expected as a large capacity negative electrode active material.
  • the Li ion secondary battery according to the conventional example has the following problems. i.
  • the active material since the active material has low electron conductivity, the amount of materials other than the active material should be reduced as much as possible in the electrode material. This is because the capacity per electrode and cell increases as the amount of materials other than the active material is reduced.
  • the Li ion diffusion length is shortened, Li ions can efficiently react with the active material in a short time, so that the refinement of the active material particles is effective in improving the charge / discharge characteristics.
  • a large amount of a binder and a conductive aid are required, and as a result, the capacity per electrode and the capacity per cell are reduced.
  • the fine particles easily aggregate, it is difficult to uniformly mix with the conductive additive, and it is difficult to secure an electron transfer path from the current collector to the active material. Therefore, in order to use the fine particle active material, a device for reducing the amount of materials other than the active material is necessary.
  • Si has a theoretical capacity about 10 times that of graphite (theoretical capacity: 370 mAh / g) used as a negative electrode material.
  • Si-based materials are highly expected as negative electrode materials for next-generation Li ion secondary batteries.
  • the Si-based material has a large volume change due to alloying / dealloying with Li.
  • the Li ion secondary battery using Si-type material as an electrode material has a problem that it does not show a stable charge / discharge cycle.
  • the present invention solves the above-described problems, and devise an electrode formation method to make it possible to manufacture a large capacity secondary battery, its manufacturing method, electrode, and lithium ion secondary battery.
  • the purpose is to provide.
  • the electrode material of the present invention comprises an active material and a carbon-based material that covers the entire surface of the active material or a part of the surface, and the carbon-based material is added to an aromatic organic solvent to which the active material is added. It is generated by performing a vibration process.
  • the method for producing an electrode material of the present invention is a carbon-based material generated from the aromatic organic solvent by subjecting the aromatic organic solvent to which the active material has been added, to the entire surface of the active material or It has the process of covering the one part surface, It is characterized by the above-mentioned.
  • the electrode of the present invention is an electrode comprising a current collector and an electrode material provided on the current collector, the electrode material comprising an active material and the entire surface of the active material or a partial surface thereof
  • the carbonaceous material is formed by subjecting the aromatic organic solvent to which the active material is added to vibration treatment.
  • the secondary battery of the present invention includes a positive electrode and a negative electrode, and an electrolyte provided between the positive electrode and the negative electrode.
  • the positive electrode or / and the negative electrode are on a current collector and the current collector.
  • the electrode material comprises an active material and an active material and a carbon-based material covering the entire surface of the active material or a part of the active material, and the carbon-based material includes the active material. It is produced by subjecting an aromatic organic solvent to which a substance is added to vibration treatment.
  • the vehicle of the present invention is equipped with the secondary battery.
  • the present invention since the entire surface or a part of the surface of the active material is covered with the carbon-based material, it is possible to provide an electrode material and an electrode having excellent conductivity and stability.
  • a secondary battery using such an electrode material and electrode can have a high capacity.
  • the vehicle carrying the said secondary battery can exhibit a high output.
  • FIG. 6 is a graph showing a Raman spectrum of a C—Si (X) Y [h] Z [W] ⁇ 600 [° C.] heat-treated sample.
  • FIG. 4 is a photograph taken by TEM of unmodified Si nanoparticles 4 and C—Si (100) 9 [h] 300 [W] samples. It is a particle size distribution figure which shows the comparative example of the average particle diameter of the sample before and behind surface coating.
  • FIG. 6 is a photograph taken by a TEM in the vicinity of a particle gap of a C—Si (100) 9 [h] 300 [W] sample.
  • FIG. 6 is a photograph taken by TEM of a C—Si (100) 9 [h] 300 [W] —H sample.
  • FIG. 4 is a photograph taken by TEM of unmodified Si nanoparticles 4 and C—Si (100) 9 [h] 300 [W] samples. It is a particle size distribution figure which shows the comparative example of the average particle diameter of the sample before and behind surface coating.
  • FIG. 6 is a photograph taken by a TEM in the vicinity of a particle gap of a C—Si (100) 9 [h] 300 [
  • FIG. 6 is a photograph taken by TEM of C—Si (100) 9 [h] 200 [W] and C—Si (100) 9 [h] 200 [W] —H samples. It is the photograph taken by TEM of the C-Si (100) 3 [h] 300 [W] sample. It is a graph which shows a X-ray photoelectron spectroscopy (XPS) analysis result. It is process drawing which shows the formation method of the negative electrode 11 as 2nd Embodiment. 3 is a configuration diagram illustrating an electrochemical measurement method for a negative electrode 11.
  • XPS X-ray photoelectron spectroscopy
  • FIG. 5 is a photograph taken by TEM of a C-LMO-LNMCO (300-12) sample. It is a graph which shows the XRD pattern of a C-LMO-LNMCO type
  • FIG. 2 is a configuration diagram illustrating an electrochemical measurement method for a positive electrode material 12.
  • FIG. It is a graph which shows the constant current charging / discharging characteristic of a LMO-LNMCO and a C-LMO-LNMCO (300-12) sample. It is a graph which shows the rate characteristic of a C-LMO-LNMCO type
  • an electrode material, a manufacturing method thereof, an electrode, and a lithium ion secondary battery according to an embodiment of the present invention will be described with reference to the drawings.
  • the inventors of the present invention by applying surface coating of Si nanoparticles with a carbon-based material with a thickness of nanometer order using ultrasonic waves, suppresses structural collapse due to volume expansion and contraction during alloying / dealloying processes. By providing conductivity, we succeeded in stabilizing the charge / discharge cycle while maintaining a high Si capacity to some extent.
  • the inventors of the present invention ultrasonically disperse an active material selected from silicon and a compound containing silicon, which is actually expected as a negative electrode material with a large capacity, in an aromatic organic solvent, and further, several ultrasonic waves are continuously generated.
  • an active material selected from silicon and a compound containing silicon which is actually expected as a negative electrode material with a large capacity, in an aromatic organic solvent, and further, several ultrasonic waves are continuously generated.
  • the entire surface of the active material or a partial surface (at least a part of the surface) of the active material was successfully coated with a carbon-based material having a thickness of several nm to several tens nm.
  • the electrode material includes an active material constituting the electrode and a carbon-based material covered on the entire surface or a part of the surface of the active material.
  • the carbon-based material is added to an aromatic organic solvent to which the active material is added. It is generated by performing the vibration process.
  • An electrode material having excellent conductivity can be provided by infiltrating (depositing) the carbon-based material into every corner of the active material crystal.
  • the active material expands and contracts with the Li ion insertion / desorption reaction.
  • By coating the active material with a carbon-based material structural collapse due to expansion and contraction of the active material can be suppressed, and a stable electrode material can be provided. Thereby, an active material is covered to every corner with a carbonaceous material, and a high capacity
  • the active material is preferably in the form of particles, and the carbon-based material is preferably formed on the surface of the particulate active material.
  • the thickness of the carbon-based material is preferably 1.0 nm or more and 50 nm or less, more preferably 2.5 nm or more and 25 nm or less, and preferably 5.0 nm or more and 10 nm or less. When the thickness of the carbon-based material is too small, there is a possibility that the influence on the improvement of the conductivity of the electrode material is reduced. When the thickness of the carbon-based material is excessive, the mass of the active material used in the electrode is relatively reduced, and the battery capacity may be reduced.
  • the carbon-based material may be further formed in the gaps between the particulate active materials. That is, the carbon-based material may be formed not only on the surface of the particulate active material but also on the gap between the active materials.
  • the carbonaceous material is amorphous, the occlusion rate of Li may be improved. Further, when the carbon-based material contains graphite, the conductivity is improved. In the Raman shift, it is preferable that the relative intensity of the peak (G band) near 1580 [cm ⁇ 1 ] with respect to the peak (D band) near 1360 [cm ⁇ 1 ] is high. Since a large amount of graphite is contained, conductivity is further increased.
  • the active material may be a negative electrode active material capable of inserting / extracting lithium ions or a positive electrode active material capable of inserting / extracting lithium ions.
  • the active material may be composed of a negative electrode active material that can occlude and release lithium ions, or a positive electrode active material that can occlude and release lithium ions.
  • the positive electrode active material may be an active material containing lithium.
  • the positive electrode active material may be made of, for example, a lithium manganese composite oxide such as a Li 2 MnO 3 active material.
  • the electrode material is formed by coating the surface of the Li 2 MnO 3 based active material a carbon-based material, and Li 2 MnO 3 based active material / carbon composite.
  • the electrode material has higher capacity and higher rate characteristics than the Li 2 MnO 3 -based active material.
  • the negative electrode active material may be an active material selected from silicon and a compound containing silicon.
  • the theoretical capacity of graphite currently used as a negative electrode material is 372 [mAh / g].
  • the theoretical capacity of the Si negative electrode active material is 4200 [mAh / g], and has a capacity 10 times or more that of graphite. For this reason, a large capacity electrode material can be provided.
  • the negative electrode active material is a lithium-containing silicon oxide
  • the lithium-containing silicon oxide is represented by a composition formula LixSiOy
  • the lithium content x and the oxygen content y are preferably 0 ⁇ x and 0 ⁇ y ⁇ 2, respectively.
  • the negative electrode active material may be Li 2 SiO 3 .
  • the electrode may include an electrode material for a negative electrode including a negative electrode active material whose entire surface or a part of the surface thereof is covered with a carbon-based material.
  • the negative electrode is preferably formed by providing an electrode material for a negative electrode on a negative electrode current collector. In this case, it greatly contributes to the stabilization of the alloy-based negative electrode active material.
  • the electrode is an electrode composed of a current collector and an electrode material provided on the current collector, and the electrode material is carbon that covers the active material and the entire surface of the active material or a part of the surface thereof. It is preferable that the carbon material is generated by subjecting the aromatic material to an aromatic organic solvent to which the active material is added.
  • the electrode may have a positive electrode material in which the entire surface or a part of the surface of the positive electrode active material containing lithium is covered with a carbon-based material.
  • the positive electrode material made of a positive electrode active material covered with a carbon-based material may be a positive electrode provided on a positive electrode current collector. In this case, it greatly contributes to the stabilization of the positive electrode active material.
  • the method for producing an electrode material includes a step of subjecting an active organic material to a surface treatment with a carbon-based material generated from the aromatic organic solvent by oscillating the aromatic organic solvent to which the active material is added. Have. When the aromatic organic solvent to which the active material is added is subjected to vibration treatment, ultrasonic waves having a predetermined frequency and a predetermined output may be irradiated for a predetermined time in the aromatic organic solvent to which the active material is added.
  • the frequency f When the frequency of the ultrasonic wave is f, the frequency f may be selected from a frequency range of 20 [kHz] ⁇ f ⁇ 800 [kHz]. For example, the frequency f may be set to 40 [kHz]. .
  • the output Z may be selected from an output range of 100 [W] ⁇ Z ⁇ 800 [W].
  • the output Z may be set to 300 [W]. .
  • a carbon-based material can be infiltrated into every corner of the crystal of the active material, providing an electrode material with excellent conductivity, and an active material associated with Li ion insertion / desorption reaction It is possible to provide a stable electrode material in which structural collapse due to expansion / contraction of the material is suppressed. Thereby, an active material is covered to every corner with a carbonaceous material, and a high capacity
  • the method for producing the electrode material may further include a step of heat-treating the surface-treated active material in which the entire surface or a part of the surface thereof is covered with the carbon-based material.
  • the temperature H is preferably selected from a heat treatment temperature range of 200 [° C.] ⁇ H ⁇ 600 [° C.].
  • the heat treatment is preferably performed in an inert atmosphere such as a halogen atmosphere such as Ar, an oxygen-free atmosphere, or a reduced oxygen atmosphere.
  • Electrode material can be provided.
  • Aromatic organic solvents have benzene halides including chloride, bromide and iodide, halogenated aromatic derivatives, vinyl groups, acetylene groups, hydroxyl groups, amino groups, nitro groups, carboxyl groups, and sulfone groups.
  • a liquid containing at least one aromatic compound selected from an aromatic derivative, a 5-membered ring aromatic compound, and a 6-membered ring aromatic compound; a solution in which the aromatic compound is dissolved may be used.
  • Organic solvent molecules can be polymerized and carbonized under local high temperature and high pressure conditions by cavitation under ultrasonic irradiation, and the surface of the active material particles can be preferentially covered with the carbon-based material.
  • dispersibility can be improved by releasing aggregation of active materials such as Si nanoparticles (C is difficult to enter the gap) under ultrasonic irradiation.
  • the carbon-based material can be made to enter the gaps between the nanoparticles as thin as possible and have conductivity, and the carbon-based material can be uniformly coated with a thickness of nanometer order. it can.
  • the secondary battery of the present invention includes a positive electrode and a negative electrode, and an electrolyte provided between the positive electrode and the negative electrode.
  • the positive electrode or / and the negative electrode are on a current collector and the current collector.
  • the electrode material comprises an active material and an active material and a carbon-based material covering the entire surface of the active material or a part of the active material, and the carbon-based material includes the active material. It may be generated by subjecting an aromatic organic solvent to which a substance has been added to vibration treatment.
  • the secondary battery of the present invention can be applied to a secondary battery such as a sodium ion secondary battery in addition to the lithium ion secondary battery described below.
  • a lithium ion secondary battery includes a positive electrode in which an electrode material made of a positive electrode active material containing lithium is provided on a positive electrode current collector, and an electrode made of a negative electrode active material in which the entire surface or a part of the surface is covered with a carbon-based material
  • the material may include a negative electrode provided on a negative electrode current collector and an electrolyte provided between the positive electrode and the negative electrode.
  • the entire surface or a part of the surface of the positive electrode active material containing lithium is covered with a carbon-based material, and an electrode material made of the positive electrode active material covered with the carbon-based material is disposed on the positive electrode current collector.
  • the positive electrode provided on the negative electrode, the negative electrode provided with the negative electrode active material on the negative electrode current collector, and the electrolyte provided between the positive electrode and the negative electrode may be provided.
  • conductivity is imparted to the positive electrode by the carbon nano-coating on the entire surface or a part of the surface of the positive electrode active material, and the positive electrode active material is stabilized. Stability can be improved. Thereby, a high capacity
  • the entire surface or a part of the surface of the positive electrode active material containing lithium is covered with a carbon-based material, and an electrode material made of the positive electrode active material covered with the carbon-based material is disposed on the positive electrode current collector.
  • conductivity is imparted to the negative electrode and the positive electrode by the carbon nano-coating on the entire surface of each of the negative electrode active material and the positive electrode active material or a part of the surface, and an alloy-based negative electrode active material
  • the positive electrode active material can be stabilized, and the stability of the charge / discharge cycle can be improved. Thereby, a high capacity
  • the electrode material may include an active material and a carbon-based material that covers the entire surface or a part of the surface of the active material.
  • the electrode material has an active material and a carbon-based material that covers the entire surface of the active material or a part of the active material, and the carbon-based material is further formed in a gap between the particulate active materials. Also good.
  • the average particle diameter of the particulate active material is preferably 3 nm or more and 500 nm or less. In X-ray photoelectron spectroscopy (XPS), a peak derived from a C ⁇ C bond may be expressed.
  • the above non-aqueous electrolyte secondary battery may be mounted on a vehicle. By driving the driving motor with the non-aqueous electrolyte secondary battery, it can be used for a long time with a large capacity and a large output.
  • the vehicle may be a vehicle that uses electric energy generated by a non-aqueous electrolyte secondary battery for all or a part of its power source.
  • the vehicle may be an electric vehicle or a hybrid vehicle.
  • Examples of non-aqueous electrolyte secondary batteries include various home electric appliances, office equipment, and industrial equipment driven by batteries, such as personal computers and portable communication devices, in addition to vehicles.
  • FIG. 1 is a diagram schematically showing the structure of the electrode material 10.
  • the electrode material 10 includes an active material 1 and a carbon-based material (hereinafter referred to as carbon-based material 2).
  • the active material 1 is a part that accumulates electricity in the battery, and is a substance that directly participates in the transfer of electrons. In general, the active material has low resistance.
  • the active material 1 constitutes a negative electrode material (electrode material for negative electrode) and a positive electrode material (electrode material for positive electrode) of the battery.
  • the negative electrode material is made of, for example, a silicon-based material.
  • the silicon-based material refers to one or more selected from Si, SiOx (0 ⁇ x ⁇ 2), and SiO 2 or a compound thereof.
  • SiO 2 is electrochemically inactive and cannot directly become the active material 1, but has a function of preventing the active material 1 from collapsing with the active material 1 together with Si and SiOx. In the examples described below, SiO 2 is present on the Si surface.
  • the surface of the active material 1 is covered with a carbon-based material 2 having a thickness of nanometer order (surface carbon coating).
  • the carbon-based material 2 is generated by, for example, subjecting the aromatic organic solvent to free radical reaction (radical reaction) by irradiating the aromatic organic solvent with a predetermined frequency and a predetermined output ultrasonic wave for a predetermined time. It is thought that.
  • the frequency range of ultrasonic waves is a frequency range that is inaudible to the human ear, for example, exceeds 20 kHz and reaches several GHz.
  • the preferable frequency range of the ultrasonic wave irradiated to the aromatic organic solvent differs depending on the Si-based active material 1, the Li 2 MnO 3 -based active material 1, the aromatic organic solvent, and the like.
  • the frequency f may be selected from a frequency range of 20 [kHz] ⁇ f ⁇ 800 [kHz].
  • the ultrasonic frequency f may be set to 40 [kHz].
  • the preferable output range of ultrasonic waves irradiated to the aromatic organic solvent varies depending on the active material 1, the aromatic organic solvent, and the like.
  • the output Z may be selected from an output range of 100 [W] ⁇ Z ⁇ 800 [W].
  • the ultrasonic output Z may be set to 200 [W] to 300 [W].
  • the range of the preferable irradiation time of the ultrasonic wave irradiated to the aromatic organic solvent varies depending on the active material 1, the aromatic organic solvent, and the like.
  • the irradiation time Y is preferably selected from an irradiation time range of 0 [h] ⁇ Y ⁇ 16 [h].
  • the ultrasonic irradiation time Y may be set to 2 [h] to 9 [h]. The reason for setting the upper limit value 16 [h] of the irradiation time Y will be described with reference to FIG.
  • the electrode material 10 when forming an electrode material for a negative electrode of a lithium (hereinafter referred to as Li) ion secondary battery, includes an active material selected from silicon and a compound containing silicon, and carbon (hereinafter referred to as Si-based / C). It is good that it is composed of a complex.
  • the compound containing silicon includes SiOx (0 ⁇ x ⁇ 2) and the like.
  • a negative electrode material containing only Si is unstable and breaks immediately.
  • the purpose of coating the active material selected from silicon and a compound containing silicon with the carbon-based material 2 is to protect Si and to impart conductivity to the Si.
  • aromatic organic solvents include halogenated benzenes including chloride, bromide and iodide, for example, dichlorobenzene (monochlorobenzene confirms only carbonization of the solvent), aromatics such as halogenated benzene and naphthalene.
  • An ultrasonic wave which is an example of a vibration treatment, is applied to a solution in which at least one aromatic compound is dissolved.
  • organic solvent molecules can be polymerized and carbonized in a local high temperature / high pressure state by cavitation, and the carbon-based material 2 is preferentially applied to the particle surface of the active material 1.
  • the dispersibility can be improved by solving the aggregation of the active material 1 such as the Si nanoparticles 4 (C is difficult to enter the gap).
  • the carbon-based material 2 can be made to enter the gap between the Si nanoparticles 4 in the thinnest possible state so as to have conductivity, and the carbon-based material 2 can be evenly distributed with a thickness of nanometer order.
  • Coating can be performed.
  • the vibration treatment is not limited to ultrasonic irradiation, but a container obtained by adding an active material to an aromatic organic solvent is placed on the vibrating body of the vibration device, and the container is subjected to vibration treatment in an Ar atmosphere.
  • the active material may be surface-treated with the carbon-based material generated by doing so.
  • Si nanoparticles in o-dichlorobenzene by adding Si nanoparticles in o-dichlorobenzene and irradiating with ultrasonic waves, the surface of the Si nanoparticles is coated with a carbon-based material 2 having a thickness on the order of nanometers to obtain a Si / C composite.
  • the modification state of the Si nanoparticle surface is TEM (transmission electron microscope), XPS (X-ray photoelectron spectroscopy), Raman spectroscopy, XRD (X-ray diffraction), elemental analysis, TG (thermogravimetric analysis), EDX (energy) (Dispersive X-ray analysis).
  • TEM transmission electron microscope
  • XPS X-ray photoelectron spectroscopy
  • Raman spectroscopy Raman spectroscopy
  • XRD X-ray diffraction
  • elemental analysis TG (thermogravimetric analysis)
  • EDX energy
  • the modification amount of the carbon-based material 2 in the above depends on the ultrasonic irradiation conditions (Si dispersion amount, output, time, etc.).
  • the temperature H is preferably selected from a heat treatment temperature range of 100 [° C.] ⁇ H ⁇ 1200 [° C.]. .
  • the lower limit temperature of 100 ° C. in the above heat treatment temperature range is the drying treatment temperature of the Si / C composite obtained by coating Si nanoparticles with the carbon-based material 2.
  • SiO 2 reacts with carbon at 1200 ° C. or more, and SiC which is undesirable in the present invention is generated.
  • the temperature is not more than this upper limit temperature.
  • the heat treatment temperature described above varies depending on the active material 1, the aromatic organic solvent, and the like. For this reason, what is necessary is just to heat-process the active material after surface carbon coating by setting optimal temperature according to the active material 1, an aromatic organic solvent, etc.
  • the heat treatment temperature is preferably less than 400 ° C.
  • the highest possible temperature is preferable in the temperature range where SiC is not generated. The reason is that carbonization proceeds with higher reproducibility at higher temperatures.
  • the heat treatment temperature is 600 ° C., for example, the chlorine component liberated from dichlorobenzene is reduced (eliminated) as described in the examples (see Table 1). Therefore, the heat treatment temperature is preferably 600 ° C. for the purpose of carbonizing the Si nanoparticles 4.
  • sample after surface carbon coating is heat-treated at a high temperature, thermal agglomeration occurs, so the sample after surface carbon coating is not only at the point of carbonization but also at the optimum temperature based on the condition of uniform surface carbon coating. May be heat-treated.
  • the structural example of the manufacturing apparatus 60 for manufacturing the electrode material 10 is demonstrated.
  • a case where the negative electrode material is formed and a composite made of silicon and carbon (Si / C) is manufactured for the negative electrode material 10 will be described as an example.
  • the manufacturing apparatus 60 shown in FIG. 2 is an apparatus that realizes a surface modification method for the carbon-based material 2 using ultrasonic waves.
  • the manufacturing apparatus 60 includes an ultrasonic adjustment device 61, a quartz cell 62, and a cooling device 63.
  • An ultrasonic vibrator 64 is attached to the quartz cell 62.
  • the ultrasonic transducer 64 is connected to the ultrasonic adjustment device 61.
  • the ultrasonic adjustment device 61 adjusts and sets the ultrasonic frequency, its output, and its irradiation time.
  • the frequency, output, and irradiation time are set by, for example, an adjustment volume provided in the ultrasonic adjustment device 61.
  • the quartz cell 62 is provided with a stirring bar 65 in addition to the ultrasonic vibrator 64.
  • reference numeral 3 denotes an aromatic organic solvent.
  • transparent colorless o-dichlorobenzene hereinafter also referred to as o-DCB3
  • the active material 1 constitutes an electrode material.
  • Si nanoparticles 4 are employed as an example of the active material 1 that is a target for surface coating.
  • the target active material 1 is not limited to the Si nanoparticles 4.
  • the active material 1 is a material that forms an alloy with Li such as Sn, an oxide such as SiOx (0 ⁇ x ⁇ 2), Nb, Fe, Ti, or the like.
  • Metal oxides, metal nitrides, and metal sulfides may be used.
  • the cooling device 63 has an upper open container 66 and a heat exchanger 67. Water 5 is placed in the upper open container 66. A lower portion of the quartz cell 62 is disposed inside the upper open container 66, and the lower portion of the quartz cell 62 is cooled. A heat exchanger 67 is provided in the upper open container 66. A cooling medium, for example, cooling water 6 is introduced (circulated) into the heat exchanger 67.
  • the ultrasonic vibrator 64 continues to irradiate ultrasonic waves in the quartz cell 62, the solution temperature in the quartz cell 62 rises. Therefore, in order to prevent deterioration of the ultrasonic transducer 64, for example, the temperature of the water 5 is maintained at 5 ° C.
  • the manufacturing apparatus 60 which implement
  • Si nanoparticle is added as the active material 1 in o-dichlorobenzene, and the surface of the Si nanoparticle is nanometer by irradiating with ultrasonic waves.
  • An Si / C composite is obtained by coating with a carbon-based material 2 having an order thickness. This Si / C composite is a sample composed of a Si nanoparticle / carbon composite.
  • powder of 100 to 150 [mg] Si nanoparticles (30 to 50 [nm]) was mixed with 200 [mL] o-DCB3. Then, in an argon (Ar) atmosphere, ultrasonic waves were irradiated under stirring under the following irradiation conditions.
  • the irradiation conditions were an ultrasonic output of 200 to 300 [W], a frequency of 40 kHz, and an irradiation time of 0 to 9 hours (hereinafter referred to as [h]).
  • Si nano-particle powder was added (mixed) to replace the atmosphere with Ar.
  • the mixed atmosphere is replaced with an Ar atmosphere.
  • SAMPLE a sample in which Si nanoparticles 4 were charged in o-DCB3 was used.
  • the sample was sonicated in step # 2.
  • the irradiation time was set to 3 [h] to 9 [h] for two types of ultrasonic output, 200 [W] and 300 [W]. It has long been known that when an aromatic organic solvent is irradiated with ultrasonic waves, it becomes black. Si nanoparticles 4 were dispersed in o-DCB3 and ultrasonic irradiation was started. After 30 minutes from the start of ultrasonic irradiation, the colorless and transparent o-DCB3 turned yellow.
  • o-DCB3 turned yellow and then turned black after several hours.
  • the organic solvent molecules were polymerized and carbonized by the radical reaction of o-DCB3, and the resulting carbon-based material 2 surface-treated the Si nanoparticles 4 (active material 1).
  • carbon C could be detected from the surface of the Si nanoparticles 4.
  • a black-colored solution containing the Si nanoparticles 4 was obtained.
  • the sample was centrifuged using a centrifuge in step # 3. Separation conditions were set such that the rotational speed of the centrifuge was set to 10,000 [rpm] and the separation time was 1 hour.
  • the black solution containing the Si nanoparticles 4 was centrifuged at 10,000 [rpm] for 1 hour to collect the precipitate.
  • the previously collected sample was dried at a temperature of 100 [° C.]. By this drying treatment, a black sample containing Si nanoparticles 4 before heat treatment at a high temperature (for example, 200 [° C.] to 600 [° C.]) was obtained.
  • Step # 6 the process was branched depending on whether the heat treatment was performed in Step # 5 or not.
  • the process proceeds to step # 6, and a notation process is performed in which a notation is given to the sample before the heat treatment.
  • C is added to the head (head)
  • the charged amount of the Si nanoparticles 4 is X [mg]
  • the ultrasonic irradiation time is Y [h].
  • the ultrasonic output is Z [W]
  • equation (1) that is, C-Si (X) Y [h] Z [W] (1)
  • the process proceeds to step # 7, and the Si nanoparticles 4 (active material 1) surface-treated with the carbon-based material 2 are heat-treated.
  • the heat treatment conditions were an electric tubular furnace, a heating rate of 10 ° C./min, a temperature of 600 [° C.], a heat treatment time of 4 hours, and an Ar atmosphere.
  • the Si nanoparticles 4 after the heat treatment showed higher capacity and higher rate characteristics than the Si nanoparticles 4 before the heat treatment.
  • the present inventors analyzed the modified state of the carbon-based material 2 by TEM observation, XPS, Raman spectroscopic analysis, XRD, elemental analysis, TG measurement, and EDX. While maintaining the Si crystal structure, the surface modification by the carbon-based material 2 and the modification to the particle gap were confirmed.
  • an XRD pattern of a C-Si (X) Y [h] Z [W] sample or the like will be described.
  • an XRD (X-ray diffraction) pattern of a C—Si (X) Y [h] Z [W] sample or the like was obtained in order to examine whether or not the Si nanoparticles 4 were present in the sample.
  • an X-ray diffractometer (Rigaku RINT-2200 (source: CuK ⁇ )) was used.
  • the XRD analysis conditions were as follows: counter cathode: CuK ⁇ , scan speed: 2.0 [degree / min], tube voltage: 40 [kV], tube current: 40 [mA], sampling interval: 0.010 [degree].
  • the vertical axis represents the X-ray diffraction intensity (Intensity)
  • the horizontal axis represents the X-ray incident angle [2 ⁇ / degree (CuK ⁇ )].
  • Comparative Example 1 is an XRD pattern of Si nanoparticles 4 without coating treatment (unmodified).
  • Example 1 is an XRD pattern of C—Si (100) 9 [h] 200 [W] only by coating treatment.
  • Example 2 is an XRD pattern of C—Si (150) 9 [h] 300 [W] only by coating treatment.
  • Example 3 is an XRD pattern of C—Si (100) 9 [h] 300 [W] only by coating treatment.
  • Example 4 is an XRD pattern of C—Si (100) 3 [h] 300 [W] only by coating treatment.
  • Comparative Example 2 is an XRD pattern of Si nanoparticles 4 without coating treatment (unmodified) + heat treatment 600 [° C.].
  • Example 5 is an XRD pattern of a C—Si (100) 9 [h] 200 [W] —H sample subjected to a coating treatment and a heat treatment of 600 [° C.].
  • Example 6 is an XRD pattern of a C—Si (150) 9 [h] 300 [W] —H sample subjected to a coating treatment and a heat treatment of 600 [° C.].
  • Example 7 is an XRD pattern of a C—Si (100) 9 [h] 300 [W] —H sample subjected to coating treatment + heat treatment 600 [° C.].
  • Example 8 is an XRD pattern of a C—Si (100) 3 [h] 300 [W] —H sample subjected to coating treatment + heat treatment 600 [° C.].
  • a Raman spectrum of a C—Si (X) Y [h] Z [W] sample or the like was acquired in order to examine whether or not the carbon-based material 2 was satisfactorily coated.
  • a Raman spectrum apparatus JASCO JASCO RMP-210 (laser light wavelength: 532 [nm]) was used. The acquisition conditions were an exposure time of 10 sec (seconds), an integration count of 20 times, and a wave number of 100 to 2000 [cm ⁇ 1 ].
  • the vertical axis represents intensity (Intensity: [Arb. Unit]), and the horizontal axis represents Raman shift ([cm ⁇ 1 ]).
  • the right figure of FIG. 5 shows an enlarged Raman spectrum of 1300 to 1800 [cm ⁇ 1 ] region.
  • Comparative Example 3 is a Raman spectrum of the Si nanoparticles 4 without coating treatment (unmodified).
  • Example 9 is a Raman spectrum of C—Si (100) 9 [h] 200 [W] only by coating treatment.
  • Example 10 is a Raman spectrum of C—Si (150) 9 [h] 300 [W] only by coating treatment.
  • Example 11 is a Raman spectrum of C—Si (100) 9 [h] 300 [W] only by coating treatment.
  • Example 12 is a Raman spectrum of C—Si (100) 3 [h] 300 [W] only by coating treatment.
  • Comparative Example 3 is a Raman spectrum of the Si nanoparticles 4 without coating treatment (unmodified). In Comparative Example 3, the carbon-based material 2 is not confirmed.
  • Example 9 is a Raman spectrum of C—Si (100) 9 [h] 200 [W] only by coating treatment.
  • Example 10 is a Raman spectrum of C—Si (150) 9 [h] 300 [W] only by coating treatment.
  • Example 11 is a Raman spectrum of C—Si (100) 9 [h] 300 [W] only by coating treatment.
  • Example 12 is a Raman spectrum of C—Si (100) 3 [h] 300 [W] only by coating treatment.
  • the peak (G band) in the vicinity of the Raman shift 1580 [cm ⁇ 1 ] in Examples 9 to 12 is graphitic carbon.
  • the peak (D band) near the Raman shift of 1360 cm ⁇ 1 is a peak derived from amorphous carbon. That is, it was found that in Examples 9 to 12, the carbon-based material 2 remained.
  • Raman such as a C—Si (X) Y [h] Z [W] —H sample is used to examine whether the carbon-based material 2 after heat treatment at 600 [° C.] remains excellent. A spectrum was acquired.
  • the Raman spectrum apparatus and acquisition conditions at that time are as described above.
  • Comparative Example 4 is a Raman spectrum of Si nanoparticles 4 without coating treatment (unmodified) + heat treatment 600 [° C.].
  • Example 13 is a Raman spectrum of a C—Si (100) 9 [h] 200 [W] —H sample subjected to a coating treatment and a heat treatment of 600 [° C.].
  • Example 14 is a Raman spectrum of a C—Si (150) 9 [h] 300 [W] —H sample subjected to a coating treatment and a heat treatment of 600 [° C.].
  • Example 15 is a Raman spectrum of a C—Si (100) 9 [h] 300 [W] —H sample subjected to a coating treatment and a heat treatment of 600 [° C.].
  • Example 16 is a Raman spectrum of a C—Si (100) 3 [h] 300 [W] —H sample subjected to coating treatment + heat treatment 600 [° C.].
  • Comparative Example 4 is a Raman spectrum of the Si nanoparticles 4 without coating treatment (unmodified) + heat treatment 600 [° C.]. In Comparative Example 4, the carbon-based material 2 was not confirmed.
  • Example 13 is a Raman spectrum of a C—Si (100) 9 [h] 200 [W] —H sample subjected to a coating treatment and a heat treatment of 600 [° C.].
  • Example 14 is a Raman spectrum of a C—Si (150) 9 [h] 300 [W] —H sample subjected to a coating treatment and a heat treatment of 600 [° C.].
  • Example 15 is a Raman spectrum of a C—Si (100) 9 [h] 300 [W] —H sample subjected to a coating treatment and a heat treatment of 600 [° C.].
  • Example 16 is a Raman spectrum of a C—Si (100) 3 [h] 300 [W] —H sample subjected to coating treatment + heat treatment 600 [° C.].
  • the amount of modification of the carbon-based material 2 described above depends on the ultrasonic irradiation conditions (Si dispersion amount, output, time, etc.). Then, with reference to FIG. 7, the relationship between ultrasonic irradiation conditions and a surface modification amount is demonstrated.
  • thermogravimetric analysis (TG) analysis in air is used to measure the weight change of the sample while changing the temperature or at a constant temperature, and estimate it from the weight change due to the decomposition of the organic matter part.
  • the amount of modification of the carbon-based material 2 was determined. From this result, as shown in the left and right diagrams of FIG. 7, the relationship between the modification amount [wt%] of the carbon-based material 2 and the ultrasonic irradiation time [hour] was created.
  • the vertical axis represents the modification amount [wt%] of the carbon-based material 2.
  • the horizontal axis represents the ultrasonic irradiation time [hour].
  • TG thermogravimetric
  • Example 17 is a white square mark and C—Si (100) 3 [h] 300 [ W].
  • Example 18 is the case of C—Si (100) 9 [h] 300 [W] with white circles.
  • Example 19 is a case of C-Si (150) 9 [h] 300 [W] with white triangle marks.
  • Example 20 is a case where C—Si (100) 9 [h] 200 [W] is indicated by white diamond marks.
  • the ultrasonic irradiation time was 3 [h]
  • the modification amount of the carbon-based material 2 was 12 [wt%].
  • the ultrasonic irradiation time is 9 [h].
  • the modification amount of the carbon-based material 2 was about 40 [wt%] in Example 18, about 5 [wt%] in Example 19, and about 12 [wt%] in Example 20.
  • Example 21 is a black square mark and C—Si (100) 3 [h] 300. This is the case of [W] -H sample.
  • Example 22 is a case of a C—Si (100) 9 [h] 300 [W] —H sample indicated by black circles.
  • Example 23 is a case of a C—Si (150) 9 [h] 300 [W] —H sample with black triangle marks.
  • Example 24 is the case of a C—Si (100) 9 [h] 200 [W] —H sample with black rhombus marks.
  • the ultrasonic irradiation time was 3 [h]
  • the modification amount of the carbon-based material 2 was 10 [wt%].
  • the ultrasonic irradiation time is 9 [h].
  • the modification amount of the carbon-based material 2 was about 30 [wt%] in Example 22, and about 8 [wt%] in both Example 23 and Example 24.
  • the modification compositions of the C-Si (100) 9 [h] 300 [W] sample and the C-Si (100) 9 [h] 300 [W] -H sample were compared.
  • the composition of the modification was analyzed by examining the relative number of moles of Si and Cl by EDX analysis (fluorescence X-ray analysis method).
  • Table 1 shows the EDX analysis results of the C—Si (100) 9 [h] 300 [W] sample and the C—Si (100) 9 [h] 300 [W] —H sample.
  • Table 2 shows organic element analysis results of the C—Si (100) 9 [h] 300 [W] sample and the C—Si (100) 9 [h] 300 [W] —H sample.
  • the meaning of carbonization means that the ratio of C in the carbon-based material is increased.
  • the ratio of H decreases, and the normal carbonization forms a graphene structure linked to the benzene skeleton, so this figure is used as a guide for carbonization .
  • the H / C weight ratio in the coating (without heat treatment) sample was 0.020, whereas the H / C ratio decreased to 0.008 after coating + heat treatment. It was found that carbonization was progressing. A carbon component was deposited on the Si nanoparticles 4 by the coating treatment of the carbon-based material 2. Even after the coating treatment, the Si crystal phase was retained. It was found that the carbonization was further advanced by the heat treatment.
  • TEM transmission electron microscope observation of the unmodified Si nanoparticles 4 and the C—Si (100) 9 [h] 300 [W] sample will be described.
  • the Si nanoparticles 4 used as the electrode material 10 had an average particle diameter of 30-50 nm.
  • a lattice image showing that the Si nanoparticles 4 had a crystal structure was observed.
  • a SiO 2 layer having a thickness of about 1 to 2 nm was observed on the surface of the Si crystal phase (lattice crystal) before the coating treatment.
  • An enlarged view of the SiO 2 layer is also shown in the photograph shown on the left side of FIG.
  • the surface of the Si crystal phase (Si nanoparticles) is covered with an amorphous layer having a thickness of about 5 nm. It was. It was found that the carbon-based material 2 has a thickness of about 5 nm and coats the surface of the Si crystal phase.
  • An enlarged view of the carbon-based material 2 is shown in the right diagram of FIG. According to this sample, an SiO 2 layer was also observed by XPS analysis.
  • the particle diameter of about 15 to 20 nm in thickness was increased. From this, it is considered that a coating layer having an average thickness of about 5 to 10 nm is formed. Thus, the carbonaceous material 2 having a thickness of nanometer order could be uniformly formed on the surface of the Si nanoparticles 4.
  • the vertical axis represents the ratio [%] of the sample (Si nanoparticle 4) showing the particle diameter
  • the horizontal axis represents the average particle diameter [nm] of the sample.
  • the ratio of the average particle diameter of the sample before surface coating shown in the upper diagram of FIG. 9, the ratio of the sample having an average particle diameter of 10 to 20 [nm] is 8 [%], and the average particle diameter of 20 to 30 [ nm] is 35 [%], the average particle size is 30 to 40 [nm], the sample is 35 [%], and the average particle size is 40 to 50 [nm]. [%], The ratio of samples having an average particle diameter of 50 to 60 [nm] was 5 [%], and the ratio of samples having an average particle diameter of 60 to 70 [nm] was also 3 [%].
  • the ratio of the average particle diameter of the sample after surface coating shown in the lower part of FIG. 9, the ratio of the sample having an average particle diameter of 20 to 30 [nm] is 1 [%], and the average particle diameter of 30 to 40 [nm] ] Is also 5 [%], the ratio of samples having an average particle diameter of 40 to 50 [nm] is 13 [%], and the ratio of samples having an average particle diameter of 50 to 60 [nm] is 33 [%]. %], The ratio of samples having an average particle diameter of 60 to 70 [nm] is 25 [%], the ratio of samples having an average particle diameter of 70 to 80 [nm] is 16 [%], and the average particle diameter is The ratio of the sample of 80 to 90 [nm] was also 5 [%].
  • the ratio of the average particle diameter of the sample before the surface coating shown in the upper part of FIG. 9 was compared with the ratio of the average particle diameter of the sample after the surface coating shown in the lower part of FIG. It was found that the average particle diameter of the sample after the surface coating shown in the lower diagram of FIG. 9 is shifted to the right as compared with the sample before the surface coating shown in the upper diagram of FIG. That is, it was found that the average particle size of the sample after the surface coating was larger than that of the sample before the surface coating.
  • the surface of the Si crystal phase (Si nanoparticles) is an amorphous layer of about 5 to 7 nm. It was found that amorphous was formed in the particle gaps of the Si nanoparticles 4 while being uniformly covered.
  • the surface coating method according to the present invention not only coats the surface of the Si nanoparticles 4 with the carbon-based material 2, but also shows that the carbon-based material 2 can be generated in the normally difficult nanoparticle gaps. As described above, the carbon-based material 2 can be formed also between the Si nanoparticles 4.
  • FIG. 11 is a TEM photograph of the C-Si (100) 9 [h] 300 [W] -H sample. According to the TEM observation example of the C—Si (100) 9 [h] 300 [W] —H sample shown in the right diagram of FIG. 11, the carbon-based material 2 could be confirmed even after the heat treatment.
  • FIG. 11 is an enlarged view near the boundary between the Si crystal phase and the carbon-based material 2.
  • the carbon-based material 2 is a portion surrounding the black Si nanoparticles of about 30-50 [nm] with a light gray color.
  • the lower left diagram in FIG. 11 is an enlarged view of the Si nanoparticles 4 and the surroundings.
  • Si nanoparticles 4 having a thickness of about 30-50 [nm] are observed, and the amorphous part around the Si nanoparticles 4 where the lattice image is confirmed is the carbon-based material 2.
  • the carbonization of the Si nanoparticles 4 can be further advanced, and the conductivity can be increased.
  • the surface of the Si nanoparticles 4 is covered with the carbon-based material 2.
  • carbonization further proceeds due to the heat treatment of the carbon-based material 2, and thermal agglomeration occurs to make it nonuniform.
  • the ultrasonic power 200 [W] +600 [° C.] even after heat treatment Si nano-particles 4 having the above were observed, and the carbon-based material 2 was also confirmed.
  • the round part is the Si nanoparticle 4
  • the surrounding amorphous part is the carbon-based material 2.
  • amorphous particles were also generated in the particle gaps.
  • the amorphous portion is the carbon-based material 2. Since the heat treatment time was as short as 3 hours, the amount of the carbon-based material 2 modified was small, but there were few completely adhered portions. As described above, when the ultrasonic wave irradiation time was short, the surface of the Si crystal phase was only partially coated, and the thickness was thin. Except for the haze on the surface of the Si crystal phase in the oblique lattice portion, it is considered that the SiO 2 layer is not coated with the carbon-based material 2.
  • XPS X-ray photoelectron spectroscopy
  • Example 25 According to the sample of C—Si (100) 9 [h] 300 [W] as Example 25 shown in the left middle diagram of FIG. 14, two peaks are observed even in the Si nanoparticle 4 only with the coating treatment. It was. The left peak is the Si crystal phase and the lower right peak is the SiO 2 layer. Further, according to the sample of Example 25 shown in the upper right diagram of FIG. 14, a C1s signal composed of several peaks due to the coating of the carbon-based material 2 was observed.
  • the peak near the binding energy of 287 eV is derived from the C—Cl bond, and the broad peak near 289 eV is derived from the C ⁇ C bond, indicating that the carbon-based material 2 contains components such as chlorine and C ⁇ C. ing.
  • the C ⁇ C bond is considered to form part of the structure of o-dichlorobenzene, which is an aromatic organic solvent. That is, the surface of the Si nanoparticle 4 is covered with the carbon-based material 2. This is because, in XPS analysis, the signal is larger at the outermost surface and becomes exponentially smaller with respect to the distance in the depth direction.
  • the active material 1 constituting the electrode for example, a material in which the carbon-based material 2 is covered on the surface of the Si nanoparticles 4 is used.
  • the carbon-based material 2 penetrates (deposits) to every corner of the crystal of the Si nanoparticle 4 and is excellent in electrical conductivity.
  • the structure collapses due to expansion / contraction of the active material accompanying Li ion insertion / desorption reaction. It is now possible to provide a stable Si nanoparticle electrode material that suppresses the above.
  • the Si / carbon composite is formed by dispersing the Si nanoparticles 4 in the organic solvent by strong ultrasonic irradiation and simultaneously polymerizing and carbonizing the organic solvent molecules. I was able to synthesize. That is, carbon having a thickness on the order of nanometers can be formed on the surface of the Si nanoparticles 4.
  • the organic solvent used for the surface modification of the Si nanoparticles 4 with the carbon-based material 2 is not limited to dichlorobenzene, and may be other aromatic compounds.
  • the surface modification method using the carbon-based material 2 is a simple method in which Si nanoparticles 4 are added to a non-polymerizable organic solvent (dichlorobenzene) and irradiated with ultrasonic waves. It is an available method.
  • the amount of carbon produced can be changed depending on the ultrasonic output, the ultrasonic irradiation time, the concentration of the active material 1, and the like.
  • the active material 1 is the Si nanoparticles 4 has been described.
  • the present invention is not limited to this, and the active material 1 is selected from compounds containing Si. SiOx (0 ⁇ x ⁇ 2 Or the like.
  • Li2SiO3 particles (particle size 1 to 10 [ ⁇ m]) were also subjected to experiments under the same conditions as in the method for producing the electrode material 10 in the Si nanoparticles 4 described above. Carbon of the order thickness could be formed. That is, a Li2SiO3 particle / carbon composite could be synthesized by dispersing Li2SiO3 particles in an organic solvent by strong ultrasonic irradiation and simultaneously polymerizing and carbonizing organic solvent molecules. From this, the present invention can also be applied to a lithium-containing silicon oxide represented by the composition formula LixSiOy and having a lithium content x and an oxygen content y of 0 ⁇ x and 0 ⁇ y ⁇ 2, respectively.
  • the formation method of the negative electrode 11 as 2nd Embodiment is demonstrated.
  • the negative electrode 11 is formed of a C—Si (X) Y [h] Z [W] sample.
  • the electrode material 10 is an electrode material for a negative electrode, that is, a negative electrode material, and is composed of Si nanoparticles 4 (negative electrode active material) whose entire surface or a part of the surface thereof is covered with the carbon-based material 2.
  • the electrode material 10 the C—Si (X) Y [h] Z [W] sample described in FIGS. 1 to 14 is used.
  • the negative electrode 11 is formed by providing an electrode material 10 on a negative electrode current collector.
  • the negative electrode 11 is formed from a (C—Si (100) 9 [h] 300 [W]) sample
  • the C ⁇ (100) 9 [h] 300 [W]) sample and the conductive auxiliary material acetylene black (AB) and a binder such as polyvinylidene fluoride resin (PVDF) or polytetrafloor styrene (PTFE) were mechanically mixed and kneaded to form a mixed paste.
  • the mixed paste was applied or pressure-bonded to the Ni mesh 7 shown in the lower part of FIG. Further, the mixed paste on the Ni mesh 7 was dried in an electric tubular furnace at a temperature of 150 [° C.], a drying time of 2 [h], and an Ar atmosphere. Thereafter, in a cold trap, the mixed paste on the Ni mesh 7 was further vacuum-dried at a temperature of 150 [° C.] and a drying time of 2 [h]. Thereby, the negative electrode 11 in which the (C—Si (100) 9 [h] 300 [W]) sample was deposited on the Ni mesh 7 was completed.
  • the entire surface or a part of the surface thereof includes the negative electrode active material covered with the carbon-based material 2, which greatly contributes to the stabilization of the alloy-based negative electrode active material.
  • the electrode material 10 has a large capacity Si negative electrode active material having a theoretical charge / discharge capacity of 4200 [mAh / g], 10 of graphite having a theoretical capacity of 372 [mAh / g] which is currently used as a negative electrode material.
  • the negative electrode 11 having a double or more capacity can be provided.
  • a tripolar cell 20 shown in FIG. 16 performs electrochemical measurement of the negative electrode 11 shown in FIG.
  • the tripolar cell 20 forms the charge / discharge principle of a Li ion secondary battery.
  • a charge / discharge measuring device 21 is used for electrochemical measurement of the negative electrode 11 (working electrode).
  • the triode cell 20 includes a clip 13, a cell container 22, a lid 23 for drawing out an electrode, an electrolyte solution 24 (Electrolyte), a counter electrode 25 (Counter electrode), a reference electrode 26 (Reference electrode), and a Lugin tube 27. ing.
  • the clip 13 sandwiched the lead wire of the negative electrode 11.
  • the clip 13 was connected to the charge / discharge measuring device 21 via a predetermined lead wire.
  • the counter electrode 25 and the reference electrode 26 were connected to a predetermined lead wire and connected to the charge / discharge measuring device 21 via the electrode lead-out lid 23.
  • metal Li bonded to Ni mesh Lion Ni mesh
  • the negative electrode 11, the counter electrode 25 and the reference electrode 26 were immersed in the electrolytic solution 24.
  • 1M LiPF 6 / [EC: DMC (1: 1)] was used as the electrolytic solution 24.
  • the weight ratio of ethylene carbonate (EC) to dimethyl carbonate (DMC) is 50:50.
  • the cell preparation was performed in an Ar atmosphere in a glove box.
  • the reference electrode 26 was brought as close as possible to the negative electrode 11 through the Lugin tube 27. Electrochemical measurement of the negative electrode 11 was performed in the triode cell 20 in an argon atmosphere. The measurement voltage range of the C—Si (100) 9 [h] 300 [W] sample constituting the negative electrode 11 is 3 to 0.01 [V]. The voltage measurement voltage range of the other sample electrodes is 2 to 0.01 [V].
  • the charge / discharge measuring device 21 For the charge / discharge measuring device 21, an electrochemical analyzer (HJ-SM8) manufactured by Hokuto Denko was used, and the measurement was performed in a constant current electricity measurement (CC) mode.
  • the charge / discharge measuring device 21 has a potentiostat or galvanostat function, and can measure at a constant potential or a constant current.
  • the current density based on the weight of Si is 210 [mA / g] and 420 [mA / g], the potential range is 0.01 [V] to 3.0 [V] vs Li / Li +, and room temperature conditions
  • the constant current charge / discharge measurement was performed. According to the constant current charge / discharge measurement, the current is made constant by the galvanostat of the charge / discharge measuring device 21, and a constant current is passed from the charge / discharge measuring device 21 to the tripolar cell 20. A method of monitoring the change in coulomb amount with the charge / discharge measuring device 21 was adopted.
  • CC mode a constant current was passed through the triode cell 20 and the amount of electricity was measured.
  • CC-CV mode in the CC mode, after a current is passed to a certain potential, the measurement is continued in the CC mode after a quantity of electricity that is held at a constant potential and not fully charged / discharged is passed.
  • Si-based electrode was subjected to electrochemical measurement in the CC mode.
  • the present inventors confirmed that the surface coating of the carbon-based material 2 improves both the charge / discharge capacity and the cycle stability as compared with the case of using only the Si negative electrode active material. Further, it was confirmed that the charge / discharge capacity of the sample subjected to the heat treatment was further increased.
  • FIG. 17 shows a charge / discharge curve (curve) of each sample under a current density condition of 420 [mA / g].
  • three electrodes of an unmodified Si nanoparticle-based sample, a C—Si (100) 9 [h] 300 [W] sample, and a C—Si (100) 9 [h] 300 [W] —H sample Material was used.
  • these charge / discharge operations were performed once to four times, and the charge / discharge characteristics were compared (considered).
  • the counter electrode 25 and the reference electrode 26 are metal Li bonded to a Ni mesh.
  • the measurement voltage range is 3 to 0.01 [V].
  • the charging current density is 420 [mA / g]. Electrochemical measurements were performed in CC mode.
  • the vertical axis represents the potential of the triode cell 20 (Potential / [V vs Li / Li + ].
  • the horizontal axis shown in the left diagram of FIG. 17 represents the Si weight of the Si nanoparticles 4.
  • the horizontal axis shown in the middle and right diagrams of Fig. 17 is the discharge capacity [mAh / g] per unit weight of the Si + -modified carbon-based material 2. It is.
  • the left diagram in FIG. 17 shows the charge / discharge characteristics of the Si nanoparticle sample.
  • numerals (1), (2), (3), (4) in the figure indicate the order of the charge / discharge cycles.
  • (1) is an initial charge / discharge curve of the Si nanoparticle sample.
  • (2) is a second charge / discharge curve of the Si nanoparticle sample.
  • (3) is the third charge / discharge curve of the Si nanoparticle sample.
  • (4) is a fourth charge / discharge curve of the Si nanoparticle sample.
  • the charge curve of the Si nanoparticle sample shown in the left diagram of FIG. It is shifted to the left as compared with the charge / discharge curve.
  • (1) is the initial charge / discharge curve of the C—Si (100) 9 [h] 300 [W] sample.
  • (2) is the second charge / discharge curve of the C—Si (100) 9 [h] 300 [W] sample.
  • (3) is the third charge / discharge curve of the C—Si (100) 9 [h] 300 [W] sample.
  • (4) is the fourth charge / discharge curve of the C—Si (100) 9 [h] 300 [W] sample.
  • the charge curve is the charge / discharge curve of the Si nanoparticle-based sample shown in the left diagram of FIG. It is shifted to the right compared to In the right diagram of FIG. 17, (1) is the initial charge / discharge curve of the C—Si (100) 9 [h] 300W—H sample. (2) is the second charge / discharge curve of the C—Si (100) 9 [h] 300W—H sample. (3) is the third charge / discharge curve of the C—Si (100) 9 [h] 300 [W] —H sample. (4) is the fourth charge / discharge curve of the C—Si (100) 9 [h] 300W—H sample.
  • the charging curve of the negative electrode 11 is due to an alloy reaction (Si + xLi ⁇ LixSi) in which the Si nanoparticles 4 occlude Li.
  • the initial charge curve also includes the capacity of the interfacial film (SEI) formation caused by electrolyte decomposition.
  • the alloy reaction (Si + xLi ⁇ LixSi) between the Si nanoparticle 4 and Li usually occurs at 0.3 [V] or less at a potential based on Li.
  • the leveling characteristics (capacity increase) of 0.3 [V] or less in the charging curves shown in each diagram of FIG. 17 indicate that this reaction occurs.
  • the characteristic that increases in capacity as the electric potential increases is a curve at the time of discharge (discharge curve).
  • the discharge curve of the negative electrode 11 is due to a dealloying reaction (LixSi ⁇ Si + xLi) that releases Li. Since the weight of the negative electrode 11 serving as a reference is different in the charge / discharge characteristics of a composite such as a Si nanoparticle 4 and a C—Si (X) Y [h] Z [W] sample, in FIG. Both figures were compared and considered.
  • the discharge characteristics of the Si-based sample will be described with reference to FIG.
  • the discharge cycle characteristics of two Si-based samples at a charging current density of 420 [mA / g] were obtained and compared. That is, the discharge cycle characteristic of each sample was determined from the charge / discharge curve (curve) of each sample measured under a current density condition of 420 [mA / g].
  • the change with the charge / discharge cycle of the discharge capacity (capacity per Si weight) of the Si nanoparticles obtained here was compared with the discharge capacity per weight of the complex of the Si + -modified carbon-based material 2.
  • the sample is C—Si (100) 9 [h] 300 [W].
  • the left figure of FIG. 18 is a discharge characteristic diagram showing the discharge capacity (SOC (charge rate): 0 to 100%) per weight of the composite (Si / C) of the Si-based sample in measurement of 1 to 10 charge / discharge cycles. It is.
  • the vertical axis represents the discharge capacity (Capacity) [mAh (g-Si) ⁇ 1 ], and the horizontal axis represents the number of cycles (Cycle Number).
  • Comparative Example 10 is a sample containing only Si (no coating), the discharge capacity per unit weight of Si is shown.
  • Comparative Example 10 indicated by a square mark is the discharge cycle characteristics of the Si nanoparticles 4 as they are.
  • the characteristic of shifting from the middle stage to the lower stage was a capacity of 100 mAh / g or less in the tenth discharge cycle.
  • Example 35 indicated by a triangle mark shows the characteristics after the coating treatment, and the capacity is low at the initial number of times, but is reversed from the characteristics of the Si nanoparticles 4 after the fourth time.
  • the discharge capacity was maintained at 200 [mAh / g] or more at the 10th time.
  • Example 36 indicated by an ellipse is a characteristic after coating treatment + heat treatment, and maintained a discharge capacity of 300 [mAh / g] or more for 10 times.
  • the right figure of FIG. 18 is a discharge characteristic diagram showing the discharge capacity (SOC: 0 to 100%) per Si weight for extracting and comparing discharge characteristics between Si.
  • the vertical axis represents the discharge capacity (Capacity) [mAh (g-Si) ⁇ 1 ], and the horizontal axis represents the number of cycles (Cycle Number).
  • Comparative Example 10 indicated by a square mark is a discharge cycle characteristic in the case of Si nanoparticles 4. According to this discharge cycle characteristic, the discharge capacity was high at 1200 [mAh / g] for the first time, but the discharge capacity rapidly decreased to 100 [mAh / g] or less at the 10th time.
  • Example 37 indicated by a triangle mark is a discharge cycle characteristic after the coating treatment.
  • the discharge capacity was high at 1250 [mAh / g] at the first time, and the discharge capacity was 400 [mAh / g] at the 10th time.
  • Example 38 indicated by a circle on the solid line shows the discharge cycle characteristics after coating and heat treatment. According to this discharge cycle characteristic, 400 [mAh / g] was maintained at the discharge capacity of the 10th time.
  • the discharge capacity rapidly decreased with an increase in the number of cycles, and almost no capacity was obtained after 10 cycles.
  • Li for example, Li 4.4 Si expands the volume four times.
  • the Si nanoparticles 4 are dealloyed, the volume shrinks to 1/4 compared to Li 4.4 Si. Due to this large volume change, pulverization occurs, resulting in a loss from the current collector and in-electrode electron conductivity due to poor contact.
  • the C—Si (100) 9 [h] 300 [W] sample shown in Example 35 on the left side of FIG. 18 had a small discharge capacity at the beginning of the cycle, but the capacity decrease with the passage of the cycle was small. After 5 cycles, rather, the discharge capacity was larger than the discharge cycle characteristics of the Si nanoparticles 4. It is considered that the surface coating with the carbon-based material 2 suppresses the structural breakdown accompanying the alloy / dealloying reaction of the Si nanoparticles 4 and enables stable charge / discharge.
  • the right diagram in FIG. 18 shows the cycle characteristics per Si weight in Comparative Example 10 in order to compare the discharge cycle characteristics on the same weight basis.
  • the Si in the C—Si (100) 9 [h] 300 [W] sample of Example 37 initially shows the same discharge capacity as that of the unmodified Si nanoparticles 4, but the cycle progresses. The capacity drop was small. That is, the cycle stability was improved by the coating of the carbon-based material 2.
  • the conductivity of the C—Si (100) 9 [h] 300 [W] —H sample of Example 38 was improved by heat treatment. As a result, it was found that the initial capacity was greatly increased.
  • the charge / discharge characteristics of the Si-based sample will be described with reference to FIG.
  • the present inventors generally increase the polarization in the electrode, thereby reducing the charge / discharge capacity.
  • the higher the charging current density the faster the alloy and dealloying reaction. Therefore, it was considered that the volume change rate is large and the structure collapse is likely to occur. Therefore, measurement was performed at a lower current density.
  • the discharge cycle characteristics of two Si-based samples at a charging current density of 210 [mA / g] were obtained, and the discharge cycle characteristics of the Si-based samples were compared. That is, the discharge cycle characteristics were determined from the charge / discharge curves of each sample measured under a current density condition of 210 [mA / g].
  • the vertical axis represents potential (Potential / [VvsLi / Li + ] and the horizontal axis represents discharge capacity (mAh / (g-Si)].
  • the unmodified Si nanoparticles 4 and the C-Si (100) 9 [h] 300 [W] sample shown in the figure and the middle figure were compared with the current density set at 210 mA / g.
  • the charging and discharging curves in the first cycle to the tenth cycle are sequentially performed from the right curve.
  • the charging curve of the negative electrode 11 with the Si nanoparticles 4 remains is due to an alloy reaction (Si + xLi ⁇ LixSi) in which the Si nanoparticles 4 occlude Li.
  • the initial charge curve also includes the capacity of the interfacial film (SEI) formation caused by electrolyte decomposition.
  • the downward-sloping characteristic in which the capacity increases as the electric potential decreases is a curve (charge curve) during charging.
  • the charging curve of the negative electrode 11 is due to an alloy reaction (Si + xLi ⁇ LixSi) between the Si nanoparticles 4 and Li.
  • the alloy reaction usually occurs at a potential based on Li of 0.3 [V] or less, and a leveling portion (capacity increase) of 0.3 [V] or less in the charging curve shown in each diagram of FIG. Indicates that a reaction is taking place.
  • a curve that rises to the right and increases in capacity as the potential increases is a curve during discharge (discharge curve).
  • the discharge curve of the negative electrode 11 is due to a dealloying reaction (LixSi ⁇ Si + xLi) that releases Li.
  • FIG. 19 is a charge / discharge curve of the negative electrode 11 after coating treatment (before heat treatment), measured under a current density condition of 210 [mA / g].
  • the charge / discharge curve shown in the right diagram of FIG. 19 is shifted to the right as compared to the charge / discharge curve shown in the left diagram of FIG.
  • the vertical axis represents discharge capacity per Si weight (Capacity) [mAh / (g-Si)], and the horizontal axis represents the number of charge / discharge cycles (Cycle Number).
  • the comparative example 12 of the round mark shown in FIG. 20 is a cycling characteristic in case the negative electrode 11 is only Si nanoparticle 4.
  • FIG. According to this cycle characteristic even at a low current density, the discharge capacity of the Si nanoparticles 4 suddenly decreased with the cycle. That is, the discharge capacity was as high as 2000 [mAh / (g-Si)] for the first time, but rapidly decreased to 100 [mAh / g] or less after the 15th time. 30 times showed almost no capacity.
  • the negative electrode 11 is a C—Si (100) 9 [h] 300 [W] sample, and the cycle characteristics of the Si nanoparticles after the coating treatment.
  • the discharge capacity was as high as 3250 [mAh / (g-Si)] at the first time, and the discharge capacity was maintained at 1000 [mAh / (g-Si)] or more at the 15th time. After 35 times, the discharge capacity was almost constant and after 60 times the discharge capacity 700 [mAh / (g-Si)] was maintained.
  • the existing graphite negative electrode material has a discharge capacity of 372 to 350 [mAh / g].
  • the electrode material in which the carbon-based material 2 is covered on the entire surface or a part of the surface of the Si nanoparticles 4 as the active material 1 is used.
  • the carbon-based material 2 is irradiated with o-DCB3 under the conditions of an ultrasonic frequency of 40 kHz, an output of 200 to 300 [W], and an irradiation time of 3 [h] to 9 [h]. It is produced by the radical reaction.
  • the carbon-based material 2 penetrates (deposits) into every corner of the crystal of the Si nanoparticle 4, so that the crystal structure of the Si nanoparticle 4 is protected from alloying and dealloying reactions, and
  • the negative electrode 11 excellent in conductivity can be provided.
  • the Si / carbon composite is synthesized by dispersing the Si nanoparticles 4 in the organic solvent by strong ultrasonic irradiation and simultaneously polymerizing and carbonizing the organic solvent molecules. That is, carbon having a thickness of nanometer order can be formed on the surface of the Si nanoparticles 4.
  • the organic solvent used for the surface modification of the Si nanoparticles 4 with the carbon-based material 2 is not limited to dichlorobenzene, and may be other aromatic compounds.
  • the surface modification method using the carbon-based material 2 is a simple method in which Si nanoparticles 4 are added to a non-polymerizable organic solvent (dichlorobenzene) and irradiated with ultrasonic waves. It is an available method.
  • the amount of carbon produced can be changed depending on the ultrasonic output, the ultrasonic irradiation time, the concentration of the active material 1, and the like.
  • the surface modification method using the carbon-based material 2 is a technology that has a high impact in practical use as a surface nano-coating method for the active material 1 of the battery.
  • a flow-type device such as a circulation device
  • the negative electrode 11 is formed. Can be produced in large quantities.
  • conductivity is imparted by the surface nano-coating of the active material 1, and stability of charge / discharge cycle characteristics can be improved.
  • the surface modification method for the carbon-based material 2 according to the present invention is also effective for stabilizing the alloy-based negative electrode active material and the negative electrode.
  • the collapse of the Si crystal structure of the negative electrode 11 can be suppressed, and the reversible characteristics of alloying and dealloying are favorably performed.
  • the negative electrode having Si nanoparticles 4 covered and protected in every corner by the carbon-based material 2 greatly contributes to the increase in capacity of Li-ion secondary batteries and the production of high-capacity Li-ion secondary batteries. .
  • the formation method of the electrode material for positive electrodes as 3rd Embodiment is demonstrated.
  • carbonization of the LMO-LNMCO particles can be further advanced by the positive electrode active material + ultrasonic carbon coating method, and the conductivity of the electrode material for the positive electrode can be increased.
  • This example is an electrode material for a positive electrode as an example of the electrode material 10, that is, a positive electrode material.
  • the positive electrode material the entire surface or a part of the surface of the positive electrode active material which is the active material 1 is covered with the carbon-based material 2.
  • the positive electrode 12 is obtained by providing a positive electrode material 10 on a positive electrode current collector.
  • Li 2 MnO 3 -based active material 1 is used as the positive electrode active material.
  • a positive electrode active material composed of a Li 2 MnO 3 based active material is covered with a carbon based material 2 to form a positive electrode material. Therefore in comparison with the active material of Li 2 MnO 3 system can provide a cathode material 12 including a high-rate characteristic Li 2 MnO 3 is obtained based active material / carbon composites with showing a higher capacity.
  • the positive electrode material according to the present invention the entire surface or a part of the surface thereof is made of the positive electrode active material covered with the carbon-based material 2, which greatly contributes to the stabilization of the positive electrode active material.
  • the method for forming a positive electrode material according to the present invention is a method for surface modification of a Li 2 MnO 3 -based active material with a carbon-based material 2.
  • a Li 2 MnO 3 -based active material with a carbon-based material 2.
  • o- dichlorobenzene by irradiating for example ultrasound after addition of Li 2 MnO 3 -based grain body as the active material 1, with ultrasonically dispersed Li 2 MnO 3 system particles of Li 2 MnO 3 system particles all The surface or a part of the surface is coated with a carbon-based material 2 having a thickness on the order of nanometers to obtain a Li 2 MnO 3 -based active material / C composite (preparation of a sample composed of Li 2 MnO 3 particles / carbon composite) .
  • o-DCB3 500 [mL] of o-DCB3 (hereinafter, o-DCB3 is also simply referred to as C) is charged as 1 [g] of 0.5Li 2 MnO 3 -0.5Li 2 Ni 1/3 Co.
  • a powder of 1/3 O 2 (hereinafter referred to as LMO-LNMCO) was mixed.
  • LMO-LNMCO 1/3 O 2
  • the irradiation conditions were an ultrasonic output of 300 [W], a frequency of 40 [kHz], and an irradiation time of 9 [h].
  • a sample in which LMO-LNMCO particles are charged in o-DCB3 is referred to as a sample (SAMPLE).
  • the sample was sonicated in step # 12.
  • the frequency f was set to 40 [kHz]
  • the output was set to 300 [W]
  • the irradiation time was set to 9 [h].
  • the color of the o-DCB3 changed to yellow and then changed to black after several hours.
  • organic solvent molecules were polymerized and carbonized by the radical reaction of o-DCB3.
  • the resulting carbon-based material 2 surface-treated the LMO-LNMCO particles (active material 1), and carbon C could be detected from the surface of the LMO-LNMCO particles as described later.
  • a black-colored solution containing LMO-LNMCO particles was obtained.
  • the sample was centrifuged using a centrifuge in step # 13. Separation conditions were set such that the rotational speed of the centrifuge was set to 10,000 [rpm] and the separation time was set to 1 hour. The solution which turned to black containing LMO-LNMCO particles was centrifuged at 10,000 [rpm] for 1 hour to collect the precipitate.
  • step # 14 the previously collected sample was dried at a temperature of 120 [° C.].
  • a black sample containing C-LMO-LNMCO particles before heat treatment at a high temperature for example, 300 [° C.] to 500 [° C.] was obtained.
  • step # 15 the process was branched depending on whether the heat treatment was performed in step # 15 or not.
  • the process proceeds to step # 16, and a notation process is performed in which a notation is given to the sample before the heat treatment.
  • C the sample not subjected to the heat treatment is expressed by the equation (3), that is, C-LMO-LNMCO (3)
  • electrochemical analysis was performed.
  • Step # 17 When performing heat treatment of the sample, the process proceeds to Step # 17, and the C-LMO-LNMCO particles (active material 1) surface-treated with the carbon-based material 2 are heat-treated.
  • the heat treatment conditions were as follows: the temperature was 300 to 500 [° C.] in an electric tubular furnace, the heat treatment time was maintained for 3 to 12 hours, and the sample was fired in an Ar atmosphere. It was possible to provide a positive electrode material that showed higher capacity and higher rate characteristics than C-LMO-LNMCO particles before heat treatment.
  • the LMO-LNMCO particles used as the active material 1 had an average particle diameter of about 30-50 [nm]. .
  • the amorphous phase is composed of the carbon-based material 2 when considered together with the results of Raman spectrum measurement and composition analysis.
  • formation of an amorphous phase was also observed in the particle gap, and carbon coating by ultrasonic treatment was confirmed also in the electrode material for the positive electrode.
  • the carbonaceous material 2 having a thickness of nanometer order could be uniformly formed on the surface of the LMO-LNMCO particles.
  • the XRD pattern of the C-LMO-LNMCO (300-12) sample or the like will be described with reference to FIG.
  • an XRD pattern of a C-LMO-LNMCO (HY) sample or the like was acquired in order to examine whether or not LMO-LNMCO particles were present in the sample.
  • the acquisition conditions are the counter cathode: CuK ⁇ , scan speed: 2.0 [degree / min], tube voltage: 40 [kV], tube current: 40 [mA], and sampling interval: 0.010 [degree].
  • the vertical axis represents the X-ray diffraction intensity (Intensity), and the horizontal axis represents the X-ray incident angle [2 ⁇ / degree (CuK ⁇ )].
  • Example 23 is an XRD pattern of LMO-LNMCO particles without coating treatment (unmodified).
  • Example 41 is an XRD pattern of C-LMO-LNMCO with only coating treatment.
  • Example 42 is an XRD pattern of a C + LMO-LNMCO (300-12) sample with coating + heat treatment.
  • Example 43 is an XRD pattern of a C + LMO-LNMCO (400-12) sample with coating plus heat treatment.
  • Example 44 is an XRD pattern of a C + LMO-LNMCO (500-12) sample with coating plus heat treatment.
  • the Raman spectrum of the C-LMO-LNMCO sample (300 [° C.]) will be described with reference to FIG.
  • a Raman spectrum of a C-LMO-LNMCO sample (300 [° C.]) was obtained in order to check whether or not the carbon-based material 2 was satisfactorily coated.
  • a Raman spectrum apparatus (JASCO Corp. JASCORMP-210 (laser beam wavelength: 532 [nm])) was used.
  • the acquisition conditions were an exposure time of 10 sec, an integration count of 20, and a wave number of 100 to 2000 [cm ⁇ 1 ].
  • the vertical axis is intensity (Intensity: [Arb. Unit]), and the horizontal axis is Raman shift (Raman shift: [cm ⁇ 1 ]. Note that FIG. 24 shows 1200 to 2000 [cm ⁇ 1 ] region. 24 is a Raman spectrum of LMO-LNMCO particles without coating treatment (unmodified), and no peak derived from the carbonaceous material 2 is confirmed in Comparative Example 14.
  • Example 45 is a Raman spectrum of C-LMO-LNMCO particles that are only coated.
  • Example 46 is the Raman spectrum of a C + LMO-LNMCO (300-3) sample with coating + heat treatment.
  • Example 47 is the Raman spectrum of a C + LMO-LNMCO (300-6) sample with coating + heat treatment.
  • Example 48 is the Raman spectrum of a C + LMO-LNMCO (300-12) sample with coating plus heat treatment.
  • the modified composition of the C-LMO-LNMCO sample will be described.
  • the composition of the carbon-based material 2 was examined by organic element analysis.
  • the content of the carbon (C), hydrogen (H), and nitrogen (N) contained in the sample was examined [wt%], and the composition of the modification was analyzed.
  • Samples of C-LMO-LNMCO before heat treatment, samples of C-LMO-LNMCO (300-3), C-LMO-LNMCO (300-6), and C-LMO-LNMCO (300-12) after heat treatment The results of organic element analysis are shown in Table 3.
  • the element content of C is 2.7 [wt%] and the element content of H is 0.0 [wt%].
  • the element content of N was 0.0 [wt%].
  • the element content of C is 2.6 [wt%] and the element content of H is 0.8 [wt%].
  • the elemental content of N was 0.0 [wt%].
  • the element content of C is 2.2 [wt%] and the element content of H is 0.8 [wt%].
  • the elemental content of N was 0.0 [wt%].
  • the element content of C is 2.4 [wt%] and the element content of H is 0.8 [wt%]. Yes, the elemental content of N was 0.0 [wt%].
  • C-LMO-LNMCO and C-LMO-LNMCO (300-Y) samples confirmed C and H elements not present in the unmodified LMO-LNMCO, and carbon-based material 2 was produced. I found out.
  • EDX analysis results of C-LMO-LNMCO sample before heat treatment C-LMO-LNMCO (300-3), C-LMO-LNMCO (300-6), and C-LMO-LNMCO (300-12) after heat treatment are shown in Table 4.
  • the Mn content is 40.33 [wt%]
  • the Co content is 12.61 [wt%]
  • the Ni content was 15.72 [wt%]
  • the Cl content was 29.29 [wt%].
  • the Mn content is 48.61 [wt%]
  • the Co content is 15.67 [wt%]
  • the Ni content was 15.72 [wt%]
  • the Cl content was 19.62 [wt%].
  • the Mn content is 50.21 [wt%]
  • the Co content is 16.21 [wt%]
  • the Ni content was 16.22 [wt%]
  • the Cl content was 14.33 [wt%].
  • C-LMO-LNMCO and C-LMO-LNMCO (300-Y) samples confirmed C and H elements not present in the unmodified LMO-LNMCO, and the carbon-based substance 2 It was found that it was generated. Further, the presence of Cl element was confirmed, and it was found that it decreased with the heat treatment time of 300 [° C.].
  • the specific surface area was 8.87 [m 2 / g].
  • the specific surface area was 15.03 [m 2 / g].
  • the specific surface area was 15.23 [m 2 / g]
  • C-LMO-LNMCO (300-6) after coating and heat treatment According to the sample, the specific surface area is 15.04 [m 2 / g]
  • the specific surface area is 15.18 [m 2 / g].
  • the electrochemical measurement of the positive electrode 12 using a positive electrode material is demonstrated.
  • the positive electrode material 12 is formed using a C—LMO-LNMCO (300-Y) sample obtained by subjecting a Li 2 MnO 3 based active material to ultrasonic carbon coating and heat treatment will be described as an example.
  • a tripolar cell 20 shown in FIG. 25 performs electrochemical measurement of the positive electrode 12 instead of the negative electrode 11 shown in FIG. Since the same reference numerals and the same names have the same functions, the description thereof is omitted.
  • the positive electrode 12 (Working electrode), the counter electrode 25 (Counter electrode), and the reference electrode 26 (Reference electrode) were connected to the charge / discharge measuring device 21 via a predetermined lead wire.
  • metal Li bonded to Ni mesh (Lion Ni mesh) was used.
  • the positive electrode material 12, the counter electrode 25, and the reference electrode 26 were immersed in the electrolytic solution 24.
  • the positive electrode 12 was subjected to electrochemical measurement in the CC-CV mode, and was charged up to 4.7 [V] only for the first time for activation.
  • the measurement was continued in the CC mode after a quantity of electricity that was held at a constant potential and was not fully charged / discharged was passed.
  • the reference electrode 26 was brought as close as possible to the positive electrode material 12 through the Lugin tube 27. Electrochemical measurement of the positive electrode 12 was performed in the triode cell 20 in an argon atmosphere.
  • C rate based on LMO-LNMCO weight is 0.2 to 5C (converted to 200 [mAh / g]), and potential range is 2.0 [V] to 4.5 [V] vs Li / Li + ,
  • Constant current charge / discharge measurement was performed under conditions of room temperature (25 ° C.). According to the constant current charge / discharge measurement, the current is made constant by the galvanostat of the charge / discharge measuring device 21, and a constant current is passed from the charge / discharge measuring device 21 to the tripolar cell 20. A method of monitoring the change in coulomb amount with the charge / discharge measuring device 21 was adopted.
  • the constant current charge / discharge characteristics of the C-LMO-LNMCO sample will be described with reference to FIG.
  • the charge / discharge capacity of the unmodified LMO-LNMCO sample (capacity per LMO-LNMCO weight) with the charge / discharge cycle and the discharge capacity of the LMO-LNMCO + modified carbon-based material 2 (LMO-LNMCO weight) (Capacity per unit) was compared with the change accompanying the charge / discharge cycle.
  • the positive electrode 12 of C-LMO-LNMCO (300-12) shown in FIG. 25 was used.
  • the vertical axis represents potential (Potential / [V vs Li / Li + ], and the horizontal axis represents discharge capacity (mAh / g), which is a capacity per LMO-LNMCO weight.
  • the curve in which the capacity increases as the potential decreases is the discharge curve, and the curve in which the capacity increases as the potential increases is the charge curve. Is the opposite.
  • the C rates are 0.2, 0.5C, 1C, 2C, and 5C in order from the curve on the right side.
  • the difference in the start potential is due to the voltage drop (IR).
  • the C-LMO-LNMCO (300-12) of Example 49 shown on the right side of FIG. 26 has both charge and discharge curves compared to the unmodified LMO-LNMCO of Comparative Example 15 shown on the left side of FIG. Shifted to the right.
  • the discharge capacity of C-LMO-LNMCO (300-12) was significantly increased as compared with unmodified LMO-LNMCO by heat treatment at 300 [° C.].
  • the voltage drop (IR drop) at the start of discharge has a small value at a high C rate in the C-LMO-LNMCO sample, indicating that polarization is suppressed. That is, it can be said that the surface modification of the carbon-based material 2 by the ultrasonic carbon coating method according to the present invention is effective for increasing the capacity by improving the conductivity. When polarization occurs, the electrode reaction cannot catch up. Further, as described in the rate characteristics shown in FIG. 27, the capacity drop at a high rate is small.
  • Example 50 is a C-LMO-LNMCO sample before heat treatment
  • Example 51 is a C-LMO-LNMCO (300-12) sample after heat treatment.
  • the rate characteristics are shown.
  • the vertical axis represents the discharge capacity (Capacity) [mAh / g] per LMO-LNMCO weight
  • the horizontal axis represents the current density [mA / g].
  • the discharge capacity of the LMO-LNMCO sample decreased with the current density. That is, the discharge capacity was as high as 215 [mAh / g] under the condition of a current density of 40 [mA / g], but the discharge capacity rapidly decreased to 100 [mAh / g] at a current density of 400 [mA / g]. . At a current density of 1000 [mA / g], the discharge capacity decreased to about 50 [mAh / g].
  • Example 50 indicated by the square marks shows the rate characteristics of the sample obtained by coating the positive electrode material 12 with the C-LMO-LNMCO sample before the heat treatment.
  • the discharge capacity is higher than that of the untreated LMO-LNMCO sample (Comparative Example 15) at 250 [mAh / g] at a current density of 40 [mA / g], and the untreated LMO-LNMCO sample (Comparative Example) even at a higher current density. 15) Higher discharge capacity was shown.
  • Example 51 indicated by triangles shows the rate characteristics of the sample after the coating and heat treatment in which the positive electrode material 12 is a C-LMO-LNMCO (300-12) sample after heat treatment.
  • the initial capacity was high and the rate characteristics were improved. That is, according to the rate characteristics after coating and heat treatment, the discharge capacity is as high as 250 [mAh / g] at a current density of 40 [mA / g] and about 150 [mAh / g] at a current density of 400 [mA / g].
  • the discharge capacity was greatly improved. Even at a current density of 1000 [mA / g], the discharge capacity was significantly improved as compared with Comparative Example 15 at about 125 [mAh / g].
  • the carbon-based material 2 is covered on the entire surface or a part of the surface of the LMO-LNMCO particles as the active material 1. Is generated by the radical reaction of o-DCB3 by irradiating the o-DCB3 with ultrasonic waves having an ultrasonic frequency of 40 kHz and an ultrasonic output of 200 to 300 [W] for an irradiation time of 9 [h].
  • the carbon-based material 2 penetrates (deposits) into every corner of the crystal of the LMO-LNMCO particles, so that the crystal structure of the LMO-LNMCO particles is protected from alloying and dealloying reactions, and An electrode material for a positive electrode having excellent conductivity can be provided.
  • a C-LMO-LNMCO composite is obtained by dispersing LMO-LNMCO particles in an organic solvent by strong ultrasonic irradiation and polymerizing / carbonizing the organic solvent molecules.
  • the organic solvent used for the surface modification with the carbonaceous material 2 is not limited to dichlorobenzene, and may be other aromatic compounds.
  • the surface modification method using the carbon-based material 2 is a simple method in which LMO-LNMCO particles are added to a non-polymerizable organic solvent (dichlorobenzene) and irradiated with ultrasonic waves. It is an available method.
  • the amount of carbon produced can be changed depending on the ultrasonic output, the ultrasonic irradiation time, the concentration of the active material 1, and the like.
  • the surface modification method using the carbon-based material 2 is a technology that has a high impact in practice as a surface nano-coating method for the active material 1 of the battery.
  • a circulation type device such as a circulation device, the positive electrode material 12 can be produced in large quantities.
  • the surface nano-coating of the active material 1 can provide conductivity and improve the stability of charge / discharge cycle characteristics. It was confirmed that the surface modification method for the carbon-based material 2 according to the present invention is effective in improving the charge / discharge characteristics of the positive electrode material.
  • the surface nano-coating of the positive electrode active material exhibits higher capacity and improves rate characteristics. This greatly contributes to increasing the capacity of a Li-ion secondary battery equipped with a positive electrode of LMO-LNMCO particles covered and protected by the carbon-based material 2 and manufacturing a high-capacity Li-ion secondary battery. .
  • a configuration example of the lithium ion secondary battery 40 as the fourth embodiment will be described with reference to FIG. 28 includes a negative electrode material 41, a positive electrode material 42, a negative electrode current collector 43, a positive electrode current collector 44, a separator 45, an electrolyte member 46, a main body housing member 47, a negative electrode.
  • a terminal 48 and a positive electrode terminal 49 are included (partially cut out).
  • the negative electrode of the Li ion secondary battery 40 has a negative electrode material 41, a negative electrode current collector 43, and a negative electrode terminal 48.
  • a negative electrode active material whose surface is covered with the carbon-based material 2 is provided on the negative electrode current collector 43.
  • the negative electrode material 41 for example, the electrode material 10 for negative electrode described in the first and second embodiments is used.
  • O-DCB3 is irradiated and generated by radical reaction of the o-DCB3.
  • a negative electrode active material such as Si nanoparticle 4 after ultrasonic carbon coating and heat treatment, a conductive agent such as acetylene black, a binder such as PVdf, Is applied to the negative electrode current collector 43 and dried.
  • a copper foil or the like band electrode having a thickness of about several tens of ⁇ m is used (see FIG. 15).
  • a foil plate such as Ni (nickel) or SUS (stainless steel) may be used in addition to the copper foil.
  • a negative electrode terminal 48 is connected to the negative electrode current collector 43.
  • the positive electrode of the Li ion secondary battery 40 has a positive electrode material 42, a positive electrode current collector 44, and a positive electrode terminal 49.
  • the positive electrode is configured by providing a positive electrode material 42 having a positive electrode active material containing lithium on a positive electrode current collector 44.
  • the positive electrode material 10 described in the third embodiment is used as the positive electrode material 42.
  • a positive electrode active material such as a C-LMO-LNMCO composite after ultrasonic carbon coating and heat treatment, a conductive agent such as acetylene black, PVdf, etc.
  • a positive electrode current collector 44 is applied to a positive electrode current collector 44 which is made into a slurry with an appropriate solvent and dried.
  • the positive electrode current collector 44 is made of an aluminum foil (band electrode) having a thickness of about several tens of ⁇ m, and a positive electrode terminal 49 is connected to the positive electrode current collector 44.
  • the positive electrode material 42 combined with the negative electrode material 41 is not limited to the positive electrode material 12 described in the third embodiment.
  • an active material such as LiCoO 2 , a conductive agent such as acetylene black, and a binder such as PVdf are slurried in an appropriate solvent. You may apply what was made to aluminum foil etc., and may dry it.
  • the positive electrode active material at that time includes, for example, a composite metal oxide containing Li, a polyanionic material such as a metal phosphate or metal silicate containing Li, a metal sulfide containing Li, or an organic polymer containing Li Substances are used.
  • the negative electrode active material used for the negative electrode material 41 includes, for example, Si particles and thin films, particles and thin films of alloy materials such as Sn, and oxides such as SiOx (0 ⁇ x ⁇ 2) in addition to the Si nanoparticles 4.
  • Si particles and thin films particles and thin films of alloy materials such as Sn, and oxides such as SiOx (0 ⁇ x ⁇ 2) in addition to the Si nanoparticles 4.
  • Lithium metal, graphite, carbon-based materials, metal oxides such as Nb, Fe, and Ti, metal nitrides, metal sulfides, and organic polymer materials may also be used.
  • the negative electrode active material may be composed of an element capable of occluding and releasing lithium ions and capable of being alloyed with lithium or / and an element compound capable of being alloyed with lithium.
  • Elements capable of alloying with lithium include Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Ti, Ag, Zn, Cd, Al, Ga, In, Si, Ge, Sn, Pb, Sb, Bi are mentioned.
  • the main body housing member 47 is arranged so that the negative electrode material 41 and the positive electrode material 42 face each other.
  • An electrolyte 46 is provided between the positive electrode and the negative electrode.
  • a separator 45 is provided at substantially the center of the electrolyte 46.
  • the separator 45 porous membrane
  • PE polyethylene
  • PP polypropylene
  • the electrolyte 46 includes a mixed solvent with a chain carbonate or an ether compound (aprotic organic solvent), a lithium salt composed of an anion having a large ionic radius, LiClO 4 , LiPF.
  • a non-aqueous solution in which 6 etc. is dissolved is used.
  • the electrolyte 46 includes an ionic liquid electrolyte in which a Li salt is dissolved in an ionic liquid composed of a cation such as 1-ethyl-3-methylimidazolium (EMI) and an anion such as (CF 3 SO 2 ) 2 N.
  • EMI 1-ethyl-3-methylimidazolium
  • the electrolyte 46 may be selected depending on the active material 1.
  • the body housing member 47 constitutes a battery can.
  • the battery can may have a cylindrical shape, a casing shape, or a flat shape.
  • a body member formed of a negative electrode material 41, a positive electrode material 42, a negative electrode current collector 43, a positive electrode current collector 44, a separator 45, and an electrolyte 46 is stored.
  • the above-mentioned main body member formed in a folded shape is stored.
  • the negative electrode material 41, the positive electrode material 42, and the like may be shared within the main body housing member 47.
  • a battery may be formed by forming a common electrode current collector coated with the negative electrode material 41 or the positive electrode material 42 and sandwiching the common electrode current collector between two electrode current collectors of the same polarity.
  • the electrolyte 46 and the separator 45 are interposed. Suitable for cylindrical battery cans.
  • different negative electrode materials 41 or positive electrode materials 42 may be arranged for one electrode current collector, and electrodes may be arranged in series to form a battery.
  • a battery having a high output voltage can be formed while being suitable for a battery-shaped battery can.
  • the negative electrode material is made of C—Si (X) y [h] Z [W] or the like, and the Si nanoparticles 4 The entire surface of the (negative electrode active material) or a part of the surface is covered with the carbon-based material 2.
  • the surface carbon nano-coating of the Si nanoparticles 4 imparts conductivity to the negative electrode, stabilizes the alloy-based negative electrode active material, and improves the stability of the charge / discharge cycle. Thereby, the high capacity
  • the positive electrode material is covered with the carbon-based material 2 on the entire surface or a part of the surface of the C-CMO-LNMCO-based CMO-LNMCO particles (positive electrode active material). ing.
  • the surface carbon nanocoating of CMO-LNMCO particles imparts conductivity to the positive electrode, stabilizes the positive electrode active material, and improves the stability of the charge / discharge cycle. Thereby, the high capacity
  • the third Li ion secondary battery includes a negative electrode and an electrolyte 46 provided between the positive electrode and the negative electrode.
  • the positive electrode material is formed by covering the entire surface or a part of the surface of C-CMO-LNMCO-based CMO-LNMCO particles (positive electrode active material) containing lithium with the carbon-based material 2.
  • the positive electrode material is provided on the positive electrode current collector 44.
  • the negative electrode material is composed of Si nanoparticles 4 whose entire surface or a part of the surface thereof is covered with the carbonaceous material 2.
  • the negative electrode is formed by providing a negative electrode material on the negative electrode current collector 43.
  • the surface carbon nano-coating of each of the Si nanoparticles 4 (negative electrode active material) and CMO-LNMCO particles (positive electrode active material) imparts conductivity to the negative electrode and the positive electrode, and the alloy-based negative electrode active material and the positive electrode active material. Stabilization is achieved, and the stability of the charge / discharge cycle can be improved. Thereby, the high capacity
  • the additive-free state refers to a state in which no active material 1 is added to o-dichlorobenzene.
  • the left diagram of FIG. 29 is an explanatory diagram showing a change in the color of o-dichlorobenzene and its ultraviolet-visible absorption spectrum during ultrasonic irradiation.
  • the vertical axis represents absorbance [arb.unit]
  • the horizontal axis represents wavelength [nm].
  • the photograph in the figure shows the ultrasonic wave of an o-dichlorobenzene-only liquid in the non-added state from the left side to the right side during six irradiation times of 20, 90, 180, 360, 540, and 1080 [min].
  • a time change of the color of the sample subjected to ultrasonic treatment is shown at an output of 300 [W] and a frequency of 40 [kHz].
  • the color of the sample in the ultrasonic treatment changed as transparent (color) ⁇ yellow ⁇ ocher ⁇ dark brown ⁇ gray ⁇ black etc. as the time of ultrasonic irradiation elapsed (black and white display: gray scale) (White ⁇ gray ⁇ black).
  • black and white display: gray scale gray scale
  • FIG. 29 is a graph showing an example of the relationship between the absorbance at each wavelength and the ultrasonic irradiation time.
  • the vertical axis represents absorbance [arb.unit]
  • the horizontal axis represents ultrasonic irradiation time [min].
  • the sample was extracted from the long wavelength side of the UV-visible absorption spectrum shown in FIG. 29A with a wavelength of 500 nm or more in which the absorbance [arb.unit] decreased and the carbon-based material 2 increased.
  • four samples having wavelengths of 500 [nm], 600 [nm], 700 [nm], and 800 [nm] are listed.
  • the upper limit of the ultrasonic irradiation time Y will be considered from this relationship graph.
  • the wavelengths are 500 [nm], 600 [nm], and 700 [nm] associated with the polymerization and the generation of the carbon-based material 2.
  • 800 [nm] it was confirmed by experiment that the ultrasonic wave irradiation time was about 16 to 18 hours and was almost saturated from the change with time of the absorption on the long wavelength side of the four samples.
  • the upper limit value Y 16 [h] (960 [min]) of the ultrasonic irradiation time is selected from the change in absorption time on the long wavelength side.
  • the upper limit value of the ultrasonic irradiation time depends on the type of the aromatic organic solvent and the frequency and output of the ultrasonic wave to be irradiated, and is not limited to this.
  • the type of active material 1 added to the aromatic organic solvent also affects.
  • the carbon-based material 2 is generated in a shorter time.
  • the range of ultrasonic irradiation conditions, the optimum conditions, and the like vary depending on the active material 1 and the aromatic organic solvent.
  • the present invention is applied to a novel surface coating method of an active material, a negative electrode material and a positive electrode material provided with a surface-coated active material, and further applied to a secondary battery including these negative electrode material and positive electrode material. Is preferred.

Abstract

The purpose of the present invention is to produce a secondary battery having a high capacity by devising a method for forming an electrode material. This electrode material comprises both an active material which constitutes a negative or positive electrode material or the like and a carbonaceous substance which covers the surface of the active material, wherein the carbonaceous substance is a substance formed by irradiating an aromatic organic solvent such as o-dichlorobenzene with an ultrasonic wave at a frequency of 40kHz and an output of 200 to 300W with an irradiation time of 2 to 9h and thus carrying out the radical reaction of the aromatic organic solvent. By this configuration, the carbonaceous substance can penetrate everywhere among the crystals of the active material to adhere thereto. Thus, an electrode material with excellent electrical conductivity can be provided. Further, stable negative and positive electrode materials wherein the structural collapse of an active material is minimized can be provided. Incidentally, the structural collapse of an active material is caused by the expansion and shrinkage thereof which are associated with insertion/extraction of Li ions.

Description

電極材料及びその製造方法、並びに電極、二次電池及び車両ELECTRODE MATERIAL AND ITS MANUFACTURING METHOD, AND ELECTRODE, SECONDARY BATTERY AND VEHICLE
　この発明は、表面コーティングされた活物質を備えた負極用及び正極用の好適な電極材料及びその製造方法、これらの電極材料を有する電極、二次電池、並びにこれを用いた車両に関する。 The present invention relates to a suitable electrode material for a negative electrode and a positive electrode provided with a surface-coated active material, a manufacturing method thereof, an electrode having these electrode materials, a secondary battery, and a vehicle using the same.
　近年、エネルギー密度が高く、携帯電話やノートパソコン等の小型電子機器の電源として、リチウム（以下Ｌｉという）イオン二次電池が幅広く利用される場合が多くなってきた。電気自動車用電源や、自然エネルギー負荷平準用の蓄電池システムなどの応用を目指して、Ｌｉイオン二次電池の高出力・大容量化が望まれている。特に、電気自動車用電源へ応用するために、Ｌｉイオン二次電池の更なる大容量化が望まれている。 In recent years, lithium (secondary) ion secondary batteries have been widely used as a power source for small electronic devices such as mobile phones and notebook computers with high energy density. Aiming for applications such as power sources for electric vehicles and storage battery systems for natural energy load leveling, it is desired to increase the output and capacity of Li-ion secondary batteries. In particular, in order to apply to a power source for electric vehicles, further increase in capacity of the Li ion secondary battery is desired.
　Ｌｉイオン二次電池は、一般に、負極材料及び負極集電体からなる負極、正極材料及び正極集電体からなる正極、セパレータ、及び電解質を備えている。負極材料には負極活物質が用いられる。負極活物質は、一般的に電子伝導性が低いために、アセチレンブラックなどのカーボン粒子が導電助剤として混合される。負極を製造するにあたっては、例えば、黒鉛等の負極活物質と、アセチレンブラック等の導電剤と、ポリテトフルオロエチン（ＰＴＦＥ）、ポリフッ化ビニデリン樹脂（ＰＶＤＦ）等の結着剤とを適当な溶剤でスラリー状にして、このスラリーを所定の厚みの銅箔等の負極集電体に塗布しそれを乾燥する。 The Li ion secondary battery generally includes a negative electrode made of a negative electrode material and a negative electrode current collector, a positive electrode made of a positive electrode material and a positive electrode current collector, a separator, and an electrolyte. A negative electrode active material is used as the negative electrode material. Since the negative electrode active material generally has low electronic conductivity, carbon particles such as acetylene black are mixed as a conductive additive. In producing the negative electrode, for example, a negative electrode active material such as graphite, a conductive agent such as acetylene black, and a binder such as polytetofluoroethine (PTFE) and polyvinylidene fluoride resin (PVDF) are used as appropriate solvents. The slurry is made into a slurry, and this slurry is applied to a negative electrode current collector such as a copper foil having a predetermined thickness and dried.
　正極を製造するに当たっては、例えば、正極活物質と、アセチレンブラック等の導電剤と、ＰＴＦＥ、ＰＶＤＦ等の結着剤とを適当な溶剤でスラリー状にして、このスラリーを所定の厚みのアルミ箔等の正極集電体に塗布し、乾燥する。 In producing the positive electrode, for example, a positive electrode active material, a conductive agent such as acetylene black, and a binder such as PTFE and PVDF are slurried with an appropriate solvent, and the slurry is made of an aluminum foil having a predetermined thickness. It is applied to a positive electrode current collector such as, and dried.
　負極と正極とは、例えば、電池缶内において対峙するように配置される。正極と負極との間には電解質が設けられる。電解質のほぼ中央にはセパレータが設けられる。セパレータには、必要に応じて使用される。セパレータは、ポリエチレン（ＰＥ）や、ポリプロピレン（ＰＰ）を微多孔質状に形成したものが使用される。電解質には所定の電解液が使用される。以上の構成により、Ｌｉイオン二次電池が構成される（図２８参照）。 The negative electrode and the positive electrode are disposed so as to face each other in a battery can, for example. An electrolyte is provided between the positive electrode and the negative electrode. A separator is provided in the approximate center of the electrolyte. It uses for a separator as needed. As the separator, polyethylene (PE) or polypropylene (PP) formed into a microporous shape is used. A predetermined electrolytic solution is used as the electrolyte. With the above configuration, a Li-ion secondary battery is configured (see FIG. 28).
　最近では、効率的なカーボン複合化方法として、カーボサーマル方法も開発されている。カーボサーマル方法は、カーボンと正極活物質とをボールミリングで混合した後に熱処理して正極活物質の粒子表面にカーボンを生成させる方法である。炭素（Ｃ）を活物質に付着させて、極力、電極材料を炭素化することで、活物質間の電子的コンタクトを取り易くしている。これにより、ある程度の導電性を確保しつつ、導電助材量を減らすことができる。 Recently, a carbothermal method has also been developed as an efficient carbon composite method. The carbothermal method is a method in which carbon and positive electrode active material are mixed by ball milling and then heat-treated to generate carbon on the particle surface of the positive electrode active material. By making carbon (C) adhere to the active material and carbonizing the electrode material as much as possible, it is easy to make electronic contact between the active materials. Thereby, it is possible to reduce the amount of conductive aid while ensuring a certain degree of conductivity.
　この種のカーボンコーティングに関連して、特表２０１０－５２８９６７号公報には、カーボンコーティングされ遷移金属酸化物からなるナノ粒子の製造方法が開示されている。このナノ粒子の製造方法は、前駆体として、１つの遷移金属のアルコキシドと、アルコールと、遷移金属に対して過剰な量の酢酸と、を含む液体混合物を準備する工程と、準備された液体混合物を水で希釈して水溶液を形成する工程と、水溶液を凍結乾燥する工程と、凍結乾燥工程で得られた凍結乾燥物を真空下もしくは不活性雰囲気下において熱分解してナノ粒子を得る工程とを有する。 In connection with this type of carbon coating, Japanese Patent Application Publication No. 2010-528967 discloses a method for producing nanoparticles coated with carbon and coated with a transition metal oxide. The method for producing nanoparticles includes preparing a liquid mixture containing, as a precursor, an alkoxide of one transition metal, an alcohol, and an excess amount of acetic acid with respect to the transition metal, and the prepared liquid mixture A step of diluting with water to form an aqueous solution, a step of freeze-drying the aqueous solution, and a step of thermally decomposing the lyophilized product obtained in the freeze-drying step under a vacuum or an inert atmosphere to obtain nanoparticles. Have
　水溶液を凍結乾燥できるように、前駆体は、ゾルの形成を防ぐモル比又は、実質的に形成させないようなモル比でもって水溶液に含まれる。ナノ粒子には、遷移金属元素、炭素元素、および、酸素元素が化学量論比でもって含まれる。 The precursor is contained in the aqueous solution at a molar ratio that prevents the formation of the sol or a molar ratio that does not substantially form the sol so that the aqueous solution can be lyophilized. Nanoparticles contain transition metal elements, carbon elements, and oxygen elements in stoichiometric ratios.
　このようなナノ粒子の製造方法により、元素周期律表の４族のチタン（Ｔｉ）、ハフニウム（Ｈｆ）、５族のバナジウム（Ｖ）、ニオブ（Ｎｂ）、タンタル（Ｔａ）、１２族の亜鉛（Ｚｎ）の中から選択された遷移元素の酸化物からなり、アモルファスカーボンによってコーティングされたナノ粒子を製造できる。 According to such a method for producing nanoparticles, group 4 titanium (Ti), hafnium (Hf), group 5 vanadium (V), niobium (Nb), tantalum (Ta), group 12 zinc in the periodic table of elements Nanoparticles made of an oxide of a transition element selected from (Zn) and coated with amorphous carbon can be produced.
　なお、元素周期律表の１４族のシリコン（Ｓｉ）は、４２００ｍＡｈ／ｇの理論充放電容量をもち、現在の負極材料として利用されている黒鉛（理論容量３７２ｍＡｈ／ｇ）の１０倍以上を有し、大容量の負極活物質材料として期待されている。 Note that group 14 silicon (Si) in the Periodic Table of Elements has a theoretical charge / discharge capacity of 4200 mAh / g, and more than 10 times the graphite (theoretical capacity 372 mAh / g) currently used as a negative electrode material. However, it is expected as a large capacity negative electrode active material.
特表２０１０－５２８９６７号公報（第８頁）JP 2010-528967 A (page 8)
　ところで、従来例に係るＬｉイオン二次電池によれば、次のような問題がある。　
　ｉ．一般に活物質は電子伝導性が低いため、電極材料においては、活物質以外の材料の量は極力減らしたい。これは活物質以外の材料の量を減らした分、電極及びセル当りの容量が増えるためである。また、Ｌｉイオン拡散長を短くすればＬｉイオンが短時間で活物質と効率よく反応できることより、活物質粒子の微細化は充放電特性の向上に有効である。しかし、微粒子からなる電極を作製するためには、結着材や導電助剤を多く必要とし、結果的に電極当たりの容量及びセル当りの容量が減ることになる。さらに微粒子は凝集しやすいため、導電助剤との均一混合が困難であり，集電体から活物質に至る電子移動経路の確保が困難となる。従って，微粒子活物質を利用するためには活物質以外の材料量を減らすための工夫が必要である。 Incidentally, the Li ion secondary battery according to the conventional example has the following problems.
i. In general, since the active material has low electron conductivity, the amount of materials other than the active material should be reduced as much as possible in the electrode material. This is because the capacity per electrode and cell increases as the amount of materials other than the active material is reduced. Further, if the Li ion diffusion length is shortened, Li ions can efficiently react with the active material in a short time, so that the refinement of the active material particles is effective in improving the charge / discharge characteristics. However, in order to produce an electrode composed of fine particles, a large amount of a binder and a conductive aid are required, and as a result, the capacity per electrode and the capacity per cell are reduced. Furthermore, since the fine particles easily aggregate, it is difficult to uniformly mix with the conductive additive, and it is difficult to secure an electron transfer path from the current collector to the active material. Therefore, in order to use the fine particle active material, a device for reducing the amount of materials other than the active material is necessary.
　ii．Ｌｉイオン二次電池の電極活物質にＳｉやＳｎなどのＬｉと合金を形成する物質を選択した場合、充放電に伴うＬｉとの合金化・脱合金化反応において、大きな体積膨張収縮による活物質の構造崩壊が生じて、電極から活物質が剥離したり導電パス等が減少したりする。このため、充放電サイクルに伴い急激に容量が低下するという問題がある。この問題は、合金系活物質のみならず活物質全般において少なからず生じ、活物質の安定性に影響を及ぼす。 Ii. When a material that forms an alloy with Li, such as Si or Sn, is selected as the electrode active material of the Li ion secondary battery, the active material due to large volume expansion and contraction in the alloying / dealloying reaction with Li accompanying charge / discharge As a result, the active material is peeled off from the electrode or the conductive path is reduced. For this reason, there exists a problem that a capacity | capacitance falls rapidly with a charging / discharging cycle. This problem occurs not only in the active material of the alloy but also in the active material as a whole, and affects the stability of the active material.
　iii．活物質を粉砕すると同時に、カーボンを粒子表面に高分散させ、熱処理によって担持させるカーボサーマル方法によれば、活物質表面全体の均一なカーボンコーティングまで至らず、十分な導電性が付与できない問題がある。特に強い凝集性があるＳｉナノ粒子等、リチウム含有ケイ素酸化物に至ってはマイクロメートルオーダーでも問題は顕著となる。因みに、特表２０１０－５２８９６７号公報に見られるような遷移金属元素、炭素元素、および、酸素元素が化学量論比でもって凍結乾燥物を所定の雰囲気下で熱分解してナノ粒子を得る方法においても、Ｓｉナノ粒子のカーボンコーティングについての報告がなされていない。 Iii. According to the carbothermal method in which the active material is pulverized and at the same time, carbon is highly dispersed on the particle surface and supported by heat treatment, there is a problem that uniform carbon coating on the entire active material surface is not achieved and sufficient conductivity cannot be imparted. . The problem becomes remarkable even in the micrometer order for lithium-containing silicon oxides such as Si nanoparticles having particularly strong cohesiveness. Incidentally, a method for obtaining nanoparticles by thermally decomposing a lyophilized product in a predetermined atmosphere with a stoichiometric ratio of transition metal elements, carbon elements, and oxygen elements as found in JP 2010-528967 A No report has been made on carbon coating of Si nanoparticles.
　iv．電気自動車用電源や、自然エネルギー負荷平準用の蓄電池システム等への応用を目指して、Ｌｉイオン二次電池の高出力・大容量化が活発に研究開発されている。しかし、活物質のナノサイズ化は、重要なキーテクノジーとなりつつあり、いかに活物質に導電性を付与するかが大きな問題となっている。 Iv. With the aim of applying it to power sources for electric vehicles, storage battery systems for leveling natural energy loads, etc., high output and large capacity of Li-ion secondary batteries are being actively researched and developed. However, nano-sizing of the active material is becoming an important key technology, and how to impart conductivity to the active material is a big problem.
　ｖ．現在、負極材料として利用されているグラファイト（理論容量３７０ｍＡｈ／ｇ）に対して、Ｓｉは約１０倍の理論容量を有する。このため、Ｓｉ系材料は、次世代Ｌｉイオン二次電池の負極材料として大いに期待されている。しかし、Ｓｉ系材料は、Ｌｉとの合金・脱合金化による体積変化が大きい。このため、Ｓｉ系材料を電極材料として用いたＬｉイオン二次電池は、安定した充放電サイクルを示さないという問題がある。 V. Currently, Si has a theoretical capacity about 10 times that of graphite (theoretical capacity: 370 mAh / g) used as a negative electrode material. For this reason, Si-based materials are highly expected as negative electrode materials for next-generation Li ion secondary batteries. However, the Si-based material has a large volume change due to alloying / dealloying with Li. For this reason, the Li ion secondary battery using Si-type material as an electrode material has a problem that it does not show a stable charge / discharge cycle.
　そこで、この発明は上述した課題を解決したものであって、電極形成方法を工夫して、大容量の二次電池を製造できるようにした電極材料及びその製造方法、電極及びリチウムイオン二次電池を提供することを目的とする。 Accordingly, the present invention solves the above-described problems, and devise an electrode formation method to make it possible to manufacture a large capacity secondary battery, its manufacturing method, electrode, and lithium ion secondary battery. The purpose is to provide.
　本発明の電極材料は、活物質と、前記活物質の全表面あるいはその一部表面を覆う炭素系物質とを備え、前記炭素系物質は、前記活物質を加えた芳香族系有機溶媒に加振処理することにより生成されてなることを特徴とする。 The electrode material of the present invention comprises an active material and a carbon-based material that covers the entire surface of the active material or a part of the surface, and the carbon-based material is added to an aromatic organic solvent to which the active material is added. It is generated by performing a vibration process.
　本発明の電極材料の製造方法は、活物質が加えられた芳香族系有機溶媒を加振処理することにより、前記芳香族系有機溶媒より生じた炭素系物質で、前記活物質の全表面或いはその一部表面を覆う工程を有することを特徴とする。 The method for producing an electrode material of the present invention is a carbon-based material generated from the aromatic organic solvent by subjecting the aromatic organic solvent to which the active material has been added, to the entire surface of the active material or It has the process of covering the one part surface, It is characterized by the above-mentioned.
　本発明の電極は、集電体と、前記集電体上に設けられた電極材料とからなる電極であって、前記電極材料は、活物質と、前記活物質の全表面あるいはその一部表面を覆う炭素系物質とからなり、前記炭素系物質は、前記活物質を加えた芳香族系有機溶媒に加振処理することにより生成されてなることを特徴とする。 The electrode of the present invention is an electrode comprising a current collector and an electrode material provided on the current collector, the electrode material comprising an active material and the entire surface of the active material or a partial surface thereof The carbonaceous material is formed by subjecting the aromatic organic solvent to which the active material is added to vibration treatment.
　本発明の二次電池は、正極及び負極と、前記正極と前記負極との間に設けられた電解質とを備え、前記正極又は／及び前記負極は、集電体と、前記集電体上に設けられた電極材料とからなる電極であって、前記電極材料は、活物質と、前記活物質の全表面あるいはその一部表面を覆う炭素系物質とからなり、前記炭素系物質は、前記活物質を加えた芳香族系有機溶媒に加振処理することにより生成されてなることを特徴とする。 The secondary battery of the present invention includes a positive electrode and a negative electrode, and an electrolyte provided between the positive electrode and the negative electrode. The positive electrode or / and the negative electrode are on a current collector and the current collector. The electrode material comprises an active material and an active material and a carbon-based material covering the entire surface of the active material or a part of the active material, and the carbon-based material includes the active material. It is produced by subjecting an aromatic organic solvent to which a substance is added to vibration treatment.
　本発明の車両は、前記二次電池を搭載したことを特徴とする。 The vehicle of the present invention is equipped with the secondary battery.
　本発明によれば、活物質の全表面あるいはその一部表面が炭素系物質により覆われているため、導電性に優れ且つ安定な電極材料及び電極を提供できる。かかる電極材料及び電極を用いた二次電池は、高い容量をもつことができる。また、上記二次電池を搭載した車両は、高い出力を発揮することができる。 According to the present invention, since the entire surface or a part of the surface of the active material is covered with the carbon-based material, it is possible to provide an electrode material and an electrode having excellent conductivity and stability. A secondary battery using such an electrode material and electrode can have a high capacity. Moreover, the vehicle carrying the said secondary battery can exhibit a high output.
本発明の第１の実施形態としての電極材料１０の構成例を示す説明図である。It is explanatory drawing which shows the structural example of the electrode material 10 as the 1st Embodiment of this invention. 電極材料１０の製造装置の構成例を示す説明図である。It is explanatory drawing which shows the structural example of the manufacturing apparatus of the electrode material. 電極材料１０の形成方法を示す工程フローチャートである。3 is a process flowchart showing a method for forming an electrode material 10. Ｃ－Ｓｉ（Ｘ）Ｙ［ｈ］Ｚ［Ｗ］試料等のＸＲＤパターンを示すグラフ図である。It is a graph which shows XRD patterns, such as a C-Si (X) Y [h] Z [W] sample. Ｃ－Ｓｉ（Ｘ）Ｙ［ｈ］Ｚ［Ｗ］試料のラマンスペクトルを示すグラフ図である。It is a graph which shows the Raman spectrum of a C-Si (X) Y [h] Z [W] sample. Ｃ－Ｓｉ（Ｘ）Ｙ［ｈ］Ｚ［Ｗ］－６００［℃］熱処理試料のラマンスペクトルを示すグラフ図である。FIG. 6 is a graph showing a Raman spectrum of a C—Si (X) Y [h] Z [W] −600 [° C.] heat-treated sample. 超音波照射条件と表面修飾量との関係例を示すグラフ図である。It is a graph which shows the example of a relationship between ultrasonic irradiation conditions and surface modification amount. 未修飾のＳｉナノ粒子４及びＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料のＴＥＭにより撮影した写真図である。FIG. 4 is a photograph taken by TEM of unmodified Si nanoparticles 4 and C—Si (100) 9 [h] 300 [W] samples. 表面コーティング前後における試料の平均粒子径の比較例を示す粒度分布図である。It is a particle size distribution figure which shows the comparative example of the average particle diameter of the sample before and behind surface coating. Ｃ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料の粒子間隙付近のＴＥＭにより撮影した写真図である。FIG. 6 is a photograph taken by a TEM in the vicinity of a particle gap of a C—Si (100) 9 [h] 300 [W] sample. Ｃ－Ｓｉ（１００）９［ｈ］３００［Ｗ］－Ｈ試料のＴＥＭにより撮影した写真図である。FIG. 6 is a photograph taken by TEM of a C—Si (100) 9 [h] 300 [W] —H sample. Ｃ－Ｓｉ（１００）９［ｈ］２００［Ｗ］及び、Ｃ－Ｓｉ（１００）９［ｈ］２００［Ｗ］－Ｈ試料のＴＥＭにより撮影した写真図である。FIG. 6 is a photograph taken by TEM of C—Si (100) 9 [h] 200 [W] and C—Si (100) 9 [h] 200 [W] —H samples. Ｃ－Ｓｉ（１００）３［ｈ］３００［Ｗ］試料のＴＥＭにより撮影した写真図である。It is the photograph taken by TEM of the C-Si (100) 3 [h] 300 [W] sample. Ｘ線光電子分光（ＸＰＳ）分析結果を示すグラフ図である。It is a graph which shows a X-ray photoelectron spectroscopy (XPS) analysis result. 第２の実施形態としての負極１１の形成方法を示す工程図である。It is process drawing which shows the formation method of the negative electrode 11 as 2nd Embodiment. 負極１１の電気化学測定方法を示す構成図である。3 is a configuration diagram illustrating an electrochemical measurement method for a negative electrode 11. FIG. Ｓｉ系試料の充放電特性（電流密度４２０ｍＡ／ｇ）を示すグラフ図である。It is a graph which shows the charge / discharge characteristic (current density of 420 mA / g) of Si type | system | group sample. Ｓｉ系試料の放電特性（電流密度４２０ｍＡ／ｇ）を示すグラフ図である。It is a graph which shows the discharge characteristic (current density 420mA / g) of Si type | system | group sample. Ｓｉ系試料の充放電特性（電流密度２１０ｍＡ／ｇ）を示すグラフ図である。It is a graph which shows the charge / discharge characteristic (current density 210mA / g) of Si type | system | group sample. Ｓｉ系試料のサイクル特性を示すグラフ図である。It is a graph which shows the cycling characteristics of Si type | system | group sample. 第３の実施形態としての正極材料１２の形成方法を示す工程フローチャートである。It is a process flowchart which shows the formation method of the positive electrode material 12 as 3rd Embodiment. Ｃ－ＬＭＯ－ＬＮＭＣＯ（３００－１２）試料のＴＥＭにより撮影した写真図である。FIG. 5 is a photograph taken by TEM of a C-LMO-LNMCO (300-12) sample. Ｃ－ＬＭＯ－ＬＮＭＣＯ系試料のＸＲＤパターンを示すグラフ図である。It is a graph which shows the XRD pattern of a C-LMO-LNMCO type | system | group sample. Ｃ－ＬＭＯ－ＬＮＭＣＯ系試料（３００［℃］）のラマンスペクトルを示すグラフ図である。It is a graph which shows the Raman spectrum of a C-LMO-LNMCO type | system | group sample (300 [degreeC]). 正極材料１２の電気化学測定方法を示す構成図である。2 is a configuration diagram illustrating an electrochemical measurement method for a positive electrode material 12. FIG. ＬＭＯ－ＬＮＭＣＯ及びＣ－ＬＭＯ－ＬＮＭＣＯ（３００－１２）試料の定電流充放電特性を示すグラフ図である。It is a graph which shows the constant current charging / discharging characteristic of a LMO-LNMCO and a C-LMO-LNMCO (300-12) sample. Ｃ－ＬＭＯ－ＬＮＭＣＯ系試料のレート特性を示すグラフ図である。It is a graph which shows the rate characteristic of a C-LMO-LNMCO type | system | group sample. 第４の実施形態としてのリチウムイオン二次電池４０の構成を示す一部切り欠きの斜視図である。It is a partially cutaway perspective view showing a configuration of a lithium ion secondary battery 40 as a fourth embodiment. ｏ－ジクロロベンゼンのみの液体に係る超音波処理を示す説明図である。It is explanatory drawing which shows the ultrasonic treatment concerning the liquid of only o-dichlorobenzene.
　以下、図面を参照しながら、この発明の実施形態に係る電極材料及びその製造方法、電極及びリチウムイオン二次電池について説明をする。本発明者らは、超音波を利用してＳｉナノ粒子をカーボン系物質によりナノメートルオーダーの厚みで表面被覆することにより、合金化・脱合金化過程の体積膨張収縮による構造崩壊を抑制するとともに導電性付与を行うことで、Ｓｉの高容量をある程度保持しつつ充放電サイクルの安定化を図ることに成功した。 Hereinafter, an electrode material, a manufacturing method thereof, an electrode, and a lithium ion secondary battery according to an embodiment of the present invention will be described with reference to the drawings. The inventors of the present invention, by applying surface coating of Si nanoparticles with a carbon-based material with a thickness of nanometer order using ultrasonic waves, suppresses structural collapse due to volume expansion and contraction during alloying / dealloying processes. By providing conductivity, we succeeded in stabilizing the charge / discharge cycle while maintaining a high Si capacity to some extent.
　本発明者らは、実際に大容量の負極材料として期待される珪素及び珪素を含む化合物から選択される活物質を芳香族系有機溶媒に超音波分散させ、更に、超音波を連続して数時間照射させることにより、数ｎｍ～数十ｎｍ厚みの炭素系物質で活物質の全表面あるいはその一部表面（少なくとも一部の表面）を被覆することに成功した。 The inventors of the present invention ultrasonically disperse an active material selected from silicon and a compound containing silicon, which is actually expected as a negative electrode material with a large capacity, in an aromatic organic solvent, and further, several ultrasonic waves are continuously generated. By irradiating for a long time, the entire surface of the active material or a partial surface (at least a part of the surface) of the active material was successfully coated with a carbon-based material having a thickness of several nm to several tens nm.
　電極材料は、電極を構成する活物質と、活物質の全表面あるいはその一部表面に覆われた炭素系物質とを備え、炭素系物質は、活物質を加えた芳香族系有機溶媒に加振処理することにより生成されたものである。活物質の結晶の隅々まで炭素系物質が浸入（被着）されることにより、導電性に優れた電極材料を提供できる。また、活物質は、Ｌｉイオン挿入・脱離反応に伴い膨張・収縮する。活物質を炭素系物質で被覆することで、活物質の膨張・収縮による構造崩壊を抑制することができ、安定な電極材料を提供できる。これにより、活物質が、炭素系物質で隅々まで覆われて、高容量のリチウムイオン二次電池を得ることができる。 The electrode material includes an active material constituting the electrode and a carbon-based material covered on the entire surface or a part of the surface of the active material. The carbon-based material is added to an aromatic organic solvent to which the active material is added. It is generated by performing the vibration process. An electrode material having excellent conductivity can be provided by infiltrating (depositing) the carbon-based material into every corner of the active material crystal. The active material expands and contracts with the Li ion insertion / desorption reaction. By coating the active material with a carbon-based material, structural collapse due to expansion and contraction of the active material can be suppressed, and a stable electrode material can be provided. Thereby, an active material is covered to every corner with a carbonaceous material, and a high capacity | capacitance lithium ion secondary battery can be obtained.
　活物質は、粒子状をなし、炭素系物質は、粒子状の前記活物質の表面に形成されているとよい。炭素系物質の厚みは、１．０ｎｍ以上５０ｎｍ以下であることがよく、更には２．５ｎｍ以上２５ｎｍ以下であることが好ましく、５．０ｎｍ以上１０ｎｍ以下であることが望ましい。炭素系物質の厚みが過小の場合には、電極材料の導電性の改善への影響が少なくなるおそれがある。炭素系物質の厚みが過大である場合には、電極中で用いられる活物質の質量が相対的に少なくなり、電池容量が低下するおそれがある。 The active material is preferably in the form of particles, and the carbon-based material is preferably formed on the surface of the particulate active material. The thickness of the carbon-based material is preferably 1.0 nm or more and 50 nm or less, more preferably 2.5 nm or more and 25 nm or less, and preferably 5.0 nm or more and 10 nm or less. When the thickness of the carbon-based material is too small, there is a possibility that the influence on the improvement of the conductivity of the electrode material is reduced. When the thickness of the carbon-based material is excessive, the mass of the active material used in the electrode is relatively reduced, and the battery capacity may be reduced.
　炭素系物質は、更に、粒子状の前記活物質の間隙に形成されているとよい。即ち、炭素系物質は、粒子状の活物質の表面だけでなく、活物質の間隙にも形成されているとよい。 The carbon-based material may be further formed in the gaps between the particulate active materials. That is, the carbon-based material may be formed not only on the surface of the particulate active material but also on the gap between the active materials.
　炭素系物質は、アモルファスであるとLiの吸蔵率が向上するのでよい。また、炭素系物質は、グラファイトを含むと導電性が高まり良い。ラマンシフトにおいて、１３６０［ｃｍ-1］付近のピーク（Ｄバンド）に対する１５８０［ｃｍ-1］付近のピーク（Ｇバンド）の相対強度が高いとよい。グラファイトが多く含まれるのでより導電性が高まる。 If the carbonaceous material is amorphous, the occlusion rate of Li may be improved. Further, when the carbon-based material contains graphite, the conductivity is improved. In the Raman shift, it is preferable that the relative intensity of the peak (G band) near 1580 [cm −1 ] with respect to the peak (D band) near 1360 [cm −1 ] is high. Since a large amount of graphite is contained, conductivity is further increased.
　活物質は、リチウムイオンを挿入・脱離し得る負極活物質、又はリチウムイオンを挿入・脱離し得る正極活物質からなるとよい。活物質は、リチウムイオンを吸蔵・放出し得る負極活物質、又はリチウムイオンを吸蔵・放出し得る正極活物質からなるとよい。負極は、正極活物質は、リチウムを含む活物質であるとよい。 The active material may be a negative electrode active material capable of inserting / extracting lithium ions or a positive electrode active material capable of inserting / extracting lithium ions. The active material may be composed of a negative electrode active material that can occlude and release lithium ions, or a positive electrode active material that can occlude and release lithium ions. In the negative electrode, the positive electrode active material may be an active material containing lithium.
　正極活物質は、例えば、Ｌｉ2ＭｎＯ3系活物質などのリチウムマンガン系複合酸化物からなるとよい。この場合、電極材料は、Ｌｉ2ＭｎＯ3系活物質の表面を炭素系物質で被覆してなる、Ｌｉ2ＭｎＯ3系活物質／カーボンの複合体となる。電極材料は、Ｌｉ2ＭｎＯ3系活物質に比べて、より高容量及び高レート特性を有する。 The positive electrode active material may be made of, for example, a lithium manganese composite oxide such as a Li 2 MnO 3 active material. In this case, the electrode material is formed by coating the surface of the Li 2 MnO 3 based active material a carbon-based material, and Li 2 MnO 3 based active material / carbon composite. The electrode material has higher capacity and higher rate characteristics than the Li 2 MnO 3 -based active material.
　負極活物質は、珪素及び珪素を含む化合物から選択される活物質であるとよい。現在負極材料として利用されている黒鉛の理論容量は３７２［ｍＡｈ／ｇ］である。Ｓｉ負極活物質の理論容量は４２００［ｍＡｈ／ｇ］であり、黒鉛の１０倍以上の容量を有する。このため、大容量の電極材料を提供できる。 The negative electrode active material may be an active material selected from silicon and a compound containing silicon. The theoretical capacity of graphite currently used as a negative electrode material is 372 [mAh / g]. The theoretical capacity of the Si negative electrode active material is 4200 [mAh / g], and has a capacity 10 times or more that of graphite. For this reason, a large capacity electrode material can be provided.
　前記負極活物質は、リチウム含有ケイ素酸化物であり、リチウム含有ケイ素酸化物は組成式ＬｉxＳｉＯyで表され、リチウム含有量ｘと酸素量ｙがそれぞれ０≦ｘ、０＜ｙ≦２であるとよい。また、前記負極活物質は、Ｌｉ２ＳｉＯ３であるとよい。 The negative electrode active material is a lithium-containing silicon oxide, the lithium-containing silicon oxide is represented by a composition formula LixSiOy, and the lithium content x and the oxygen content y are preferably 0 ≦ x and 0 <y ≦ 2, respectively. . The negative electrode active material may be Li 2 SiO 3 .
　電極は、炭素系物質により全表面あるいはその一部表面が覆われた負極活物質を含む負極用の電極材料を有するとよい。負極は、負極用の電極材料が負極集電体上に設けられて形成されているとよい。この場合には、合金系負極活物質の安定化に大きく寄与する。 The electrode may include an electrode material for a negative electrode including a negative electrode active material whose entire surface or a part of the surface thereof is covered with a carbon-based material. The negative electrode is preferably formed by providing an electrode material for a negative electrode on a negative electrode current collector. In this case, it greatly contributes to the stabilization of the alloy-based negative electrode active material.
　電極は、集電体と、前記集電体上に設けられた電極材料とからなる電極であって、前記電極材料は、活物質と、前記活物質の全表面あるいはその一部表面を覆う炭素系物質とからなり、前記炭素系物質は、前記活物質を加えた芳香族系有機溶媒に加振処理することにより生成されてなるとよい。 The electrode is an electrode composed of a current collector and an electrode material provided on the current collector, and the electrode material is carbon that covers the active material and the entire surface of the active material or a part of the surface thereof. It is preferable that the carbon material is generated by subjecting the aromatic material to an aromatic organic solvent to which the active material is added.
　電極は、リチウムを含む正極活物質の全表面あるいはその一部表面が炭素系物質により覆われてなる正極用の電極材料を有するとよい。炭素系物質により覆われた正極活物質からなる正極用の電極材料が正極集電体上に設けられる正極であるとよい。この場合には、正極活物質の安定化に大きく寄与する。 The electrode may have a positive electrode material in which the entire surface or a part of the surface of the positive electrode active material containing lithium is covered with a carbon-based material. The positive electrode material made of a positive electrode active material covered with a carbon-based material may be a positive electrode provided on a positive electrode current collector. In this case, it greatly contributes to the stabilization of the positive electrode active material.
　電極材料の製造方法は、活物質が加えられた芳香族系有機溶媒を加振処理することにより、前記芳香族系有機溶媒より生じた炭素系物質で、当該活物質を表面処理する工程とを有する。活物質を加えた芳香族系有機溶媒を加振処理する際に、当該活物質を加えた芳香族系有機溶媒中で、所定周波数及び所定出力の超音波を所定時間照射するとよい。 The method for producing an electrode material includes a step of subjecting an active organic material to a surface treatment with a carbon-based material generated from the aromatic organic solvent by oscillating the aromatic organic solvent to which the active material is added. Have. When the aromatic organic solvent to which the active material is added is subjected to vibration treatment, ultrasonic waves having a predetermined frequency and a predetermined output may be irradiated for a predetermined time in the aromatic organic solvent to which the active material is added.
　超音波の周波数をｆとしたとき、前記周波数ｆは２０［ｋＨｚ］≦ｆ≦８００［ｋＨｚ］の周波数範囲から選択されるとよく、例えば、周波数ｆが４０［ｋＨｚ］に設定されるとよい。 When the frequency of the ultrasonic wave is f, the frequency f may be selected from a frequency range of 20 [kHz] ≦ f ≦ 800 [kHz]. For example, the frequency f may be set to 40 [kHz]. .
　超音波の出力をＺとしたとき、前記出力Ｚは１００［Ｗ］≦Ｚ≦８００［Ｗ］の出力範囲から選択されるとよく、例えば、出力Ｚが３００［Ｗ］に設定されるとよい。 When the ultrasonic output is Z, the output Z may be selected from an output range of 100 [W] ≦ Z ≦ 800 [W]. For example, the output Z may be set to 300 [W]. .
　超音波の照射時間をＹとしたとき、０［ｈ］＜Ｙ≦１６［ｈ］の照射時間範囲から選択されるとよく、例えば、Ｙ＝９［ｈ］に設定されるとよい。 When the ultrasonic irradiation time is Y, it may be selected from an irradiation time range of 0 [h] <Y ≦ 16 [h]. For example, Y = 9 [h] may be set.
　電極材料の製造方法によれば、活物質の結晶の隅々まで炭素系物質を浸入させることができ、導電性に優れた電極材料を提供するとともに、Ｌｉイオン挿入・脱離反応に伴う活物質の膨張・収縮による構造崩壊を抑制した安定な電極材料を提供できる。これにより、活物質が、炭素系物質で隅々まで覆われて、高容量のリチウムイオン二次電池を得ることができる。 According to the method for producing an electrode material, a carbon-based material can be infiltrated into every corner of the crystal of the active material, providing an electrode material with excellent conductivity, and an active material associated with Li ion insertion / desorption reaction It is possible to provide a stable electrode material in which structural collapse due to expansion / contraction of the material is suppressed. Thereby, an active material is covered to every corner with a carbonaceous material, and a high capacity | capacitance lithium ion secondary battery can be obtained.
　電極材料の製造方法は、更に、炭素系物質で全表面或いはその一部表面が覆われた表面処理された活物質を熱処理する工程を有するとよい。活物質の熱処理の温度をＨとしたとき、温度Ｈは１００［℃］≦Ｈ≦１２００［℃］の熱処理温度範囲から選択されるとよく、例えば、Ｌｉ2ＭｎＯ3系の熱処理の実施例では、Ｈ＝３００［℃］に設定され、Ｓｉ系の熱処理の実施例では、Ｈ＝６００［℃］に設定されるとよい。 The method for producing the electrode material may further include a step of heat-treating the surface-treated active material in which the entire surface or a part of the surface thereof is covered with the carbon-based material. When the temperature of the heat treatment of the active material is H, the temperature H is preferably selected from a heat treatment temperature range of 100 [° C.] ≦ H ≦ 1200 [° C.], for example, in the embodiment of the Li 2 MnO 3 heat treatment H = 300 [° C.], and in the embodiment of the Si-based heat treatment, H = 600 [° C.] may be set.
　更に、温度Ｈは２００［℃］≦Ｈ≦６００［℃］の熱処理温度範囲から選択されることが好ましい。また、熱処理は、Ａｒなどのハロゲン雰囲気、無酸素雰囲気、減酸素雰囲気などの不活性雰囲気下で行うことが好ましい。 Furthermore, the temperature H is preferably selected from a heat treatment temperature range of 200 [° C.] ≦ H ≦ 600 [° C.]. The heat treatment is preferably performed in an inert atmosphere such as a halogen atmosphere such as Ar, an oxygen-free atmosphere, or a reduced oxygen atmosphere.
　炭素系物質で表面処理された活物質、例えば、Ｓｉ系の実施例では、Ｈ＝６００［℃］で熱処理するので、熱処理前の活物質に比べてより高容量を示すと共に高レート特性が得られる電極材料を提供できる。 In an active material surface-treated with a carbon-based material, for example, a Si-based embodiment, heat treatment is performed at H = 600 [° C.], so that a higher capacity and higher rate characteristics can be obtained than the active material before heat treatment. Electrode material can be provided.
　芳香族系有機溶媒には、塩化物、臭化物及びヨウ化物を含むハロゲン化ベンゼン、ハロゲン化された芳香族誘導体、ビニル基、アセチレン基、水酸基、アミノ基、ニトロ基、カルボキシル基、スルホン基を有する芳香族誘導体、５員環芳香族化合物、６員環芳香族化合物から選択される少なくとも一種からなる芳香族系化合物を含む液体；芳香族系化合物を溶解させた溶液を使用するとよい。 Aromatic organic solvents have benzene halides including chloride, bromide and iodide, halogenated aromatic derivatives, vinyl groups, acetylene groups, hydroxyl groups, amino groups, nitro groups, carboxyl groups, and sulfone groups. A liquid containing at least one aromatic compound selected from an aromatic derivative, a 5-membered ring aromatic compound, and a 6-membered ring aromatic compound; a solution in which the aromatic compound is dissolved may be used.
　超音波照射の下で、キャビテーションによる局所的な高温・高圧状態で、有機溶媒分子を重合・カーボン化させることができ、活物質の粒子表面に優先的に炭素系物質を覆うことができる。また、超音波照射の下で、Ｓｉナノ粒子等の活物質の凝集（Ｃが隙間に入りにくい）を解いて分散性を高めることができる。これにより、ナノ粒子の間隙にも炭素系物質を可能な限り薄く、かつ、導電性を持たせるために進入させることができ、炭素系物質のナノメートルオーダーの厚みでの均一コーティングを行うことができる。 ∙ Organic solvent molecules can be polymerized and carbonized under local high temperature and high pressure conditions by cavitation under ultrasonic irradiation, and the surface of the active material particles can be preferentially covered with the carbon-based material. In addition, dispersibility can be improved by releasing aggregation of active materials such as Si nanoparticles (C is difficult to enter the gap) under ultrasonic irradiation. As a result, the carbon-based material can be made to enter the gaps between the nanoparticles as thin as possible and have conductivity, and the carbon-based material can be uniformly coated with a thickness of nanometer order. it can.
　本発明の二次電池は、正極及び負極と、前記正極と前記負極との間に設けられた電解質とを備え、前記正極又は／及び前記負極は、集電体と、前記集電体上に設けられた電極材料とからなる電極であって、前記電極材料は、活物質と、前記活物質の全表面あるいはその一部表面を覆う炭素系物質とからなり、前記炭素系物質は、前記活物質を加えた芳香族系有機溶媒に加振処理することにより生成されてなるとよい。本発明の二次電池は、以下に述べるリチウムイオン二次電池の他、例えば、ナトリウムイオン二次電池などの二次電池にも適用できる。 The secondary battery of the present invention includes a positive electrode and a negative electrode, and an electrolyte provided between the positive electrode and the negative electrode. The positive electrode or / and the negative electrode are on a current collector and the current collector. The electrode material comprises an active material and an active material and a carbon-based material covering the entire surface of the active material or a part of the active material, and the carbon-based material includes the active material. It may be generated by subjecting an aromatic organic solvent to which a substance has been added to vibration treatment. The secondary battery of the present invention can be applied to a secondary battery such as a sodium ion secondary battery in addition to the lithium ion secondary battery described below.
　リチウムイオン二次電池は、リチウムを含む正極活物質からなる電極材料が正極集電体上に設けられた正極と、全表面あるいはその一部表面を炭素系物質により覆った負極活物質からなる電極材料が負極集電体上に設けられた負極と、前記正極と負極との間に設けられた電解質とを備えるとよい。このリチウムイオン二次電池によれば、負極活物質表面のカーボンナノコーティングにより負極に導電性が付与されると共に、合金系負極活物質の安定化が図られ、充放電サイクルの安定性の向上が図れる。これにより、高容量のリチウムイオン二次電池を提供できる。 A lithium ion secondary battery includes a positive electrode in which an electrode material made of a positive electrode active material containing lithium is provided on a positive electrode current collector, and an electrode made of a negative electrode active material in which the entire surface or a part of the surface is covered with a carbon-based material The material may include a negative electrode provided on a negative electrode current collector and an electrolyte provided between the positive electrode and the negative electrode. According to this lithium ion secondary battery, conductivity is imparted to the negative electrode by the carbon nano coating on the surface of the negative electrode active material, the alloy negative electrode active material is stabilized, and the stability of the charge / discharge cycle is improved. I can plan. Thereby, a high capacity | capacitance lithium ion secondary battery can be provided.
　リチウムイオン二次電池は、リチウムを含む正極活物質の全表面あるいはその一部表面が炭素系物質により覆われ、当該炭素系物質により覆われた正極活物質からなる電極材料が正極集電体上に設けられた正極と、負極活物質からなる電極材料が負極集電体上に設けられた負極と、正極と負極との間に設けられた電解質とを備えるとよい。このリチウムイオン二次電池によれば、正極活物質の全表面あるいはその一部表面のカーボンナノコーティングにより正極に導電性が付与されると共に、正極活物質の安定化が図られ、充放電サイクルの安定性の向上が図れる。これにより、高容量のリチウムイオン二次電池を提供できる。 In the lithium ion secondary battery, the entire surface or a part of the surface of the positive electrode active material containing lithium is covered with a carbon-based material, and an electrode material made of the positive electrode active material covered with the carbon-based material is disposed on the positive electrode current collector. The positive electrode provided on the negative electrode, the negative electrode provided with the negative electrode active material on the negative electrode current collector, and the electrolyte provided between the positive electrode and the negative electrode may be provided. According to this lithium ion secondary battery, conductivity is imparted to the positive electrode by the carbon nano-coating on the entire surface or a part of the surface of the positive electrode active material, and the positive electrode active material is stabilized. Stability can be improved. Thereby, a high capacity | capacitance lithium ion secondary battery can be provided.
　リチウムイオン二次電池は、リチウムを含む正極活物質の全表面あるいはその一部表面が炭素系物質により覆われ、当該炭素系物質により覆われた正極活物質からなる電極材料が正極集電体上に設けられた正極と、表面が炭素系物質により覆われた負極活物質からなる電極材料が負極集電体上に設けられた負極と、正極と負極との間に設けられた電解質とを備えるとよい。このリチウムイオン二次電池によれば、負極活物質及び正極活物質の各々の全表面あるいはその一部表面のカーボンナノコーティングにより、負極及び正極に導電性が付与されると共に、合金系負極活物質及び正極活物質の安定化が図られ、充放電サイクルの安定性の向上が図れる。これにより、高容量のリチウムイオン二次電池を提供できる。 In the lithium ion secondary battery, the entire surface or a part of the surface of the positive electrode active material containing lithium is covered with a carbon-based material, and an electrode material made of the positive electrode active material covered with the carbon-based material is disposed on the positive electrode current collector. A negative electrode provided on a negative electrode current collector, and an electrolyte provided between the positive electrode and the negative electrode. Good. According to this lithium ion secondary battery, conductivity is imparted to the negative electrode and the positive electrode by the carbon nano-coating on the entire surface of each of the negative electrode active material and the positive electrode active material or a part of the surface, and an alloy-based negative electrode active material In addition, the positive electrode active material can be stabilized, and the stability of the charge / discharge cycle can be improved. Thereby, a high capacity | capacitance lithium ion secondary battery can be provided.
　また、電極材料は、活物質と、前記活物質の全表面あるいはその一部表面を覆う炭素系物質とを有してもよい。電極材料は、活物質と、前記活物質の全表面あるいはその一部表面を覆う炭素系物質とを有しており、炭素系物質は、更に、粒子状の活物質の間隙に形成されていてもよい。粒子状の前記活物質の平均粒径は、３ｎｍ以上５００ｎｍ以下であるとよい。Ｘ線光電子分光分析（ＸＰＳ）において、Ｃ＝Ｃ結合に由来するピークが発現されるとよい。 In addition, the electrode material may include an active material and a carbon-based material that covers the entire surface or a part of the surface of the active material. The electrode material has an active material and a carbon-based material that covers the entire surface of the active material or a part of the active material, and the carbon-based material is further formed in a gap between the particulate active materials. Also good. The average particle diameter of the particulate active material is preferably 3 nm or more and 500 nm or less. In X-ray photoelectron spectroscopy (XPS), a peak derived from a C═C bond may be expressed.
　上記の非水系電解質二次電池は、車両に搭載してもよい。上記の非水系電解質二次電池で走行用モータを駆動することにより、大容量、大出力で、長時間使用することができる。車両は、その動力源の全部あるいは一部に非水系電解質二次電池による電気エネルギーを使用している車両であれば良く，例えば、電気車両、ハイブリッド車両などであるとよい。非水系電解質二次電池は、車両以外にも、パーソナルコンピュータ，携帯通信機器など，電池で駆動される各種の家電製品，オフィス機器，産業機器が挙げられる。 The above non-aqueous electrolyte secondary battery may be mounted on a vehicle. By driving the driving motor with the non-aqueous electrolyte secondary battery, it can be used for a long time with a large capacity and a large output. The vehicle may be a vehicle that uses electric energy generated by a non-aqueous electrolyte secondary battery for all or a part of its power source. For example, the vehicle may be an electric vehicle or a hybrid vehicle. Examples of non-aqueous electrolyte secondary batteries include various home electric appliances, office equipment, and industrial equipment driven by batteries, such as personal computers and portable communication devices, in addition to vehicles.
　以下、本発明の実施形態及び実施例について図面を用いて説明する。 Hereinafter, embodiments and examples of the present invention will be described with reference to the drawings.
　＜第１の実施形態＞
　［電極材料］
　図１は、電極材料１０の構造を模式的に表した図である。電極材料１０は、活物質１及び炭素系物質（以下カーボン系物質２という）からなる。活物質１は電池において、電気をためる部分であって、電子の受け渡しに直接関与する物質である。一般に活物質は抵抗が低い。活物質１は、電池の負極材料（負極用の電極材料）や正極材料（正極用の電極材料）を構成する。負極材料は、例えば、シリコン系材料から構成される。ここにシリコン系材料とは、Ｓｉ，ＳｉＯｘ（０＜ｘ＜２），ＳｉＯ2から選択される一種以上、又は、それらの化合物をいう。ＳｉＯ2は電気化学的に不活性であり、直接、活物質１になり得ないが、ＳｉやＳｉＯｘとともに活物質１に混入して活物質１の崩壊を防止する機能がある。以下に述べる実施例でもＳｉ表面にＳｉＯ2が存在している。 <First Embodiment>
[Electrode material]
FIG. 1 is a diagram schematically showing the structure of the electrode material 10. The electrode material 10 includes an active material 1 and a carbon-based material (hereinafter referred to as carbon-based material 2). The active material 1 is a part that accumulates electricity in the battery, and is a substance that directly participates in the transfer of electrons. In general, the active material has low resistance. The active material 1 constitutes a negative electrode material (electrode material for negative electrode) and a positive electrode material (electrode material for positive electrode) of the battery. The negative electrode material is made of, for example, a silicon-based material. Here, the silicon-based material refers to one or more selected from Si, SiOx (0 <x <2), and SiO 2 or a compound thereof. SiO 2 is electrochemically inactive and cannot directly become the active material 1, but has a function of preventing the active material 1 from collapsing with the active material 1 together with Si and SiOx. In the examples described below, SiO 2 is present on the Si surface.
　活物質１の表面は、ナノメートルオーダーの厚みのカーボン系物質２によって覆われて（表面カーボンコーティングされて）いる。カーボン系物質２は、所定周波数及び所定出力の超音波が所定時間、芳香族系有機溶媒に照射されることで、例えば、当該芳香族系有機溶媒が遊離基反応（ラジカル反応）して生成されたものと考えられる。 The surface of the active material 1 is covered with a carbon-based material 2 having a thickness of nanometer order (surface carbon coating). The carbon-based material 2 is generated by, for example, subjecting the aromatic organic solvent to free radical reaction (radical reaction) by irradiating the aromatic organic solvent with a predetermined frequency and a predetermined output ultrasonic wave for a predetermined time. It is thought that.
　一般に超音波の周波数域は、人間の耳に聞こえない、例えば、２０ｋＨｚを越え、数ＧＨｚに至る周波数範囲である。芳香族系有機溶媒に照射される超音波の好ましい周波数の範囲は、Ｓｉ系の活物質１や、Ｌｉ2ＭｎＯ3系の活物質１や、芳香族系有機溶媒等で異なる。ここで超音波の周波数をｆとしたとき、以下に述べる実施例では、周波数ｆは２０［ｋＨｚ］≦ｆ≦８００［ｋＨｚ］の周波数範囲から選択されるとよい。例えば、Ｓｉ系の活物質１や、Ｌｉ2ＭｎＯ3系の活物質１の加振処理において、超音波の周波数ｆが４０［ｋＨｚ］に設定されてもよい。 In general, the frequency range of ultrasonic waves is a frequency range that is inaudible to the human ear, for example, exceeds 20 kHz and reaches several GHz. The preferable frequency range of the ultrasonic wave irradiated to the aromatic organic solvent differs depending on the Si-based active material 1, the Li 2 MnO 3 -based active material 1, the aromatic organic solvent, and the like. Here, assuming that the frequency of the ultrasonic wave is f, in the embodiment described below, the frequency f may be selected from a frequency range of 20 [kHz] ≦ f ≦ 800 [kHz]. For example, in the vibration treatment of the Si-based active material 1 or the Li 2 MnO 3 -based active material 1, the ultrasonic frequency f may be set to 40 [kHz].
　また、芳香族系有機溶媒に照射される超音波の好ましい出力の範囲は、活物質１や、芳香族系有機溶媒等によって異なる。超音波の出力をＺとしたとき、出力Ｚは１００［Ｗ］≦Ｚ≦８００［Ｗ］の出力範囲から選択されるとよい。例えば、活物質１の加振処理において、超音波の出力Ｚは２００［Ｗ］～３００［Ｗ］に設定されるとよい。 In addition, the preferable output range of ultrasonic waves irradiated to the aromatic organic solvent varies depending on the active material 1, the aromatic organic solvent, and the like. When the ultrasonic output is Z, the output Z may be selected from an output range of 100 [W] ≦ Z ≦ 800 [W]. For example, in the vibration processing of the active material 1, the ultrasonic output Z may be set to 200 [W] to 300 [W].
　更に、芳香族系有機溶媒に照射される超音波の好ましい照射時間の範囲は、活物質１や、芳香族系有機溶媒等によって異なる。超音波の照射時間をＹとしたとき、照射時間Ｙは、０［ｈ］＜Ｙ≦１６［ｈ］の照射時間範囲から選択されるとよい。例えば、活物質１の加振処理において、超音波の照射時間Ｙは２［ｈ］～９［ｈ］に設定されるとよい。照射時間Ｙの上限値１６［ｈ］については、図２９でその設定理由を説明する。 Furthermore, the range of the preferable irradiation time of the ultrasonic wave irradiated to the aromatic organic solvent varies depending on the active material 1, the aromatic organic solvent, and the like. When the ultrasonic irradiation time is Y, the irradiation time Y is preferably selected from an irradiation time range of 0 [h] <Y ≦ 16 [h]. For example, in the vibration treatment of the active material 1, the ultrasonic irradiation time Y may be set to 2 [h] to 9 [h]. The reason for setting the upper limit value 16 [h] of the irradiation time Y will be described with reference to FIG.
　この例で、リチウム（以下Ｌｉという）イオン二次電池の負極用の電極材料を形成する場合、電極材料１０は、珪素及び珪素を含む化合物から選択される活物質及び炭素（以下Ｓｉ系／Ｃという）の複合体によって構成されるとよい。珪素を含む化合物には、ＳｉＯｘ（０＜ｘ＜２）等が含まれる。Ｓｉのみの負極材料は不安定で、直ぐに壊れてしまう。珪素及び珪素を含む化合物から選択される活物質をカーボン系物質２でコーティングする目的は、Ｓｉを保護すること、及び、当該Ｓｉに導電性を付与することである。 In this example, when forming an electrode material for a negative electrode of a lithium (hereinafter referred to as Li) ion secondary battery, the electrode material 10 includes an active material selected from silicon and a compound containing silicon, and carbon (hereinafter referred to as Si-based / C). It is good that it is composed of a complex. The compound containing silicon includes SiOx (0 <x <2) and the like. A negative electrode material containing only Si is unstable and breaks immediately. The purpose of coating the active material selected from silicon and a compound containing silicon with the carbon-based material 2 is to protect Si and to impart conductivity to the Si.
　上述の芳香族系有機溶媒には、塩化物、臭化物及びヨウ化物を含むハロゲン化ベンゼン、例えば、ジクロロベンゼン（モノクロロベンゼンは溶媒の炭素化のみを確認）、ハロゲン化されたベンゼンやナフタレン等の芳香族誘導体、ビニル基、アセチレン基、水酸基、アミノ基、ニトロ基、カルボキシル基、スルホン基を有する芳香族誘導体、５員環芳香族化合物（ピロール、チオフェン、フランの誘導体）、６員環芳香族化合物（ピリジン誘導体等）から選択される少なくとも一種を含む液体、あるいは、塩化物、臭化物及びヨウ化物を含むハロゲン化ベンゼン、ハロゲン化された芳香族誘導体、ビニル基、アセチレン基、水酸基、アミノ基、ニトロ基、カルボキシル基、スルホン基を有する芳香族誘導体、５員環芳香族化合物、６員環芳香族化合物から選択される少なくとも一種を溶解させた溶液が使用されるとよい。 The above aromatic organic solvents include halogenated benzenes including chloride, bromide and iodide, for example, dichlorobenzene (monochlorobenzene confirms only carbonization of the solvent), aromatics such as halogenated benzene and naphthalene. Aromatic derivatives, vinyl groups, acetylene groups, hydroxyl groups, amino groups, nitro groups, carboxyl groups, sulfone groups, 5-membered aromatic compounds (pyrrole, thiophene, furan derivatives), 6-membered aromatic compounds (Liquid containing at least one selected from pyridine derivatives, etc.), or halogenated benzene containing chloride, bromide and iodide, halogenated aromatic derivative, vinyl group, acetylene group, hydroxyl group, amino group, nitro Group, carboxyl group, aromatic derivative having sulfone group, 5-membered aromatic compound, 6-membered ring aromatic Solution prepared by dissolving at least one selected from the group compounds may be used.
　電極材料１０の製造方法によれば、芳香族誘導体、５員環芳香族化合物、６員環芳香族化合物から選択される少なくとも一種からなる芳香族系化合物を含む液体、あるいは、これらから選択される少なくとも一種からなる芳香族系化合物を溶解させた溶液に、加振処理の一例となる超音波を照射する。この場合、この超音波照射の下で、キャビテーションによる局所的な高温・高圧状態で、有機溶媒分子を重合・カーボン化させることができ、活物質１の粒子表面に優先的にカーボン系物質２を覆うことができる。また、超音波照射の下で、Ｓｉナノ粒子４等の活物質１の凝集（Ｃが隙間に入りにくい）を解いて分散性を高めることができる。 According to the manufacturing method of the electrode material 10, the liquid containing the aromatic compound which consists of at least 1 type selected from an aromatic derivative, a 5-membered aromatic compound, and a 6-membered aromatic compound, or selected from these An ultrasonic wave, which is an example of a vibration treatment, is applied to a solution in which at least one aromatic compound is dissolved. In this case, under this ultrasonic irradiation, organic solvent molecules can be polymerized and carbonized in a local high temperature / high pressure state by cavitation, and the carbon-based material 2 is preferentially applied to the particle surface of the active material 1. Can be covered. Further, under ultrasonic irradiation, the dispersibility can be improved by solving the aggregation of the active material 1 such as the Si nanoparticles 4 (C is difficult to enter the gap).
　これにより、Ｓｉナノ粒子４の間隙にも、カーボン系物質２を可能な限り薄い状態で、導電性を持たせるために進入させることができ、カーボン系物質２のナノメートルオーダーの厚みでの均一コーティングを行うことができる。なお、加振処理については超音波照射に限られることはなく、振動装置の振動体上に、芳香族系有機溶媒に活物質を加えた容器を載置し、この容器をＡｒ雰囲気で振動処理することにより生じた炭素系物質で当該活物質を表面処理してもよい。 As a result, the carbon-based material 2 can be made to enter the gap between the Si nanoparticles 4 in the thinnest possible state so as to have conductivity, and the carbon-based material 2 can be evenly distributed with a thickness of nanometer order. Coating can be performed. The vibration treatment is not limited to ultrasonic irradiation, but a container obtained by adding an active material to an aromatic organic solvent is placed on the vibrating body of the vibration device, and the container is subjected to vibration treatment in an Ar atmosphere. The active material may be surface-treated with the carbon-based material generated by doing so.
　［負極活物質＋超音波カーボンコート法］
　本発明の主な特徴は次の通りである。 [Negative electrode active material + ultrasonic carbon coating method]
The main features of the present invention are as follows.
　ｉ．ｏ－ジクロロベンゼン中に、例えば、Ｓｉナノ粒子を加え、超音波照射することにより、Ｓｉナノ粒子表面をナノメートルオーダーの厚みのカーボン系物質２でコーティングしてＳｉ／Ｃ複合体を得る。 I. For example, by adding Si nanoparticles in o-dichlorobenzene and irradiating with ultrasonic waves, the surface of the Si nanoparticles is coated with a carbon-based material 2 having a thickness on the order of nanometers to obtain a Si / C composite.
　ii．Ｓｉナノ粒子表面の修飾状態は、ＴＥＭ（透過型電子顕微鏡）、ＸＰＳ（Ｘ線光電子分光分析）、ラマン分光分析、ＸＲＤ（Ｘ線回折）、元素分析、ＴＧ（熱重量分析）、ＥＤＸ（エネルギー分散型Ｘ線分析）により分析した。分析の結果、Ｓｉ結晶構造を保持しつつカーボン系物質２による表面修飾、粒子間隙への修飾を確認した。 Ii. The modification state of the Si nanoparticle surface is TEM (transmission electron microscope), XPS (X-ray photoelectron spectroscopy), Raman spectroscopy, XRD (X-ray diffraction), elemental analysis, TG (thermogravimetric analysis), EDX (energy) (Dispersive X-ray analysis). As a result of the analysis, the surface modification by the carbon-based material 2 and the modification to the particle gap were confirmed while maintaining the Si crystal structure.
　iii．上記におけるカーボン系物質２の修飾量は、超音波照射条件（Ｓｉ分散量、出力、時間など）に依存する。 Iii. The modification amount of the carbon-based material 2 in the above depends on the ultrasonic irradiation conditions (Si dispersion amount, output, time, etc.).
　iv．定電流充放電測定において、上記コーティングにより、Ｓｉのみと比べて、充放電容量、サイクル安定性ともに向上することを確認した。 Iv. In the constant current charge / discharge measurement, it was confirmed that both the charge / discharge capacity and the cycle stability were improved by the coating as compared with Si alone.
　ｖ．Ｓｉナノ粒子の表面修飾を行った後に熱処理を行った試料は、充放電容量がさらに増加する。 V. The charge / discharge capacity of the sample subjected to the heat treatment after the surface modification of the Si nanoparticles is further increased.
　本発明に係る電極材料１０の製造方法において、活物質１の熱処理の温度をＨとしたとき、温度Ｈは１００［℃］≦Ｈ≦１２００［℃］の熱処理温度範囲から選択されることがよい。好ましくは、Ｌｉ2ＭｎＯ3系試料の熱処理の実施例で、Ｈ＝３００［℃］に設定され、Ｓｉ系試料の熱処理の実施例で、Ｈ＝６００［℃］に設定されるとよい。 In the method for manufacturing the electrode material 10 according to the present invention, when the temperature of the heat treatment of the active material 1 is H, the temperature H is preferably selected from a heat treatment temperature range of 100 [° C.] ≦ H ≦ 1200 [° C.]. . Preferably, H = 300 [° C.] is set in the embodiment of the heat treatment of the Li 2 MnO 3 sample, and H = 600 [° C.] is set in the embodiment of the heat treatment of the Si sample.
　上記熱処理温度範囲の下限温度１００℃は、カーボン系物質２でＳｉナノ粒子をコーティングして得たＳｉ／Ｃ複合体の乾燥処理温度である。上限温度１２００℃では、例えばＳｉＯ2が１２００℃以上でカーボンと反応して、本発明で望ましくないＳｉＣが生成する。少なくとも、以下で述べる実施例のＳｉ粒子系においては、この上限温度以下であるとよい。 The lower limit temperature of 100 ° C. in the above heat treatment temperature range is the drying treatment temperature of the Si / C composite obtained by coating Si nanoparticles with the carbon-based material 2. At an upper limit temperature of 1200 ° C., for example, SiO 2 reacts with carbon at 1200 ° C. or more, and SiC which is undesirable in the present invention is generated. At least in the Si particle system of the embodiment described below, it is preferable that the temperature is not more than this upper limit temperature.
　上述の熱処理温度は、活物質１や、芳香族系有機溶媒等で異なる。このため、活物質１や、芳香族系有機溶媒等に応じて、最適な温度を設定して、表面カーボンコーティング後の活物質を熱処理すればよい。Ｌｉ2ＭｎＯ3系試料の場合、実施例（図２３のＸＲＤ参照）でも説明するように、温度４００℃以上の熱処理では不純物相が生成するので、熱処理温度は、４００℃未満が好ましい。 The heat treatment temperature described above varies depending on the active material 1, the aromatic organic solvent, and the like. For this reason, what is necessary is just to heat-process the active material after surface carbon coating by setting optimal temperature according to the active material 1, an aromatic organic solvent, etc. In the case of a Li 2 MnO 3 sample, an impurity phase is generated in a heat treatment at a temperature of 400 ° C. or higher as described in the examples (see XRD in FIG. 23). Therefore, the heat treatment temperature is preferably less than 400 ° C.
　Ｓｉ系試料では、ＳｉＣが生成しない温度域で可能な限り高温が好ましい。その理由は、高温ほどカーボン化が再現性良く進行するためである。熱処理温度が６００℃である場合には、実施例（表１参照）で説明するように、例えば、ジクロロベンゼンから遊離される塩素成分が低減される（無くなる）。このため、熱処理温度は６００℃であることは、Ｓｉナノ粒子４のカーボン化という目的で好ましい。 In the Si-based sample, the highest possible temperature is preferable in the temperature range where SiC is not generated. The reason is that carbonization proceeds with higher reproducibility at higher temperatures. When the heat treatment temperature is 600 ° C., for example, the chlorine component liberated from dichlorobenzene is reduced (eliminated) as described in the examples (see Table 1). Therefore, the heat treatment temperature is preferably 600 ° C. for the purpose of carbonizing the Si nanoparticles 4.
　ただし、表面カーボンコーティング後の試料を高温で熱処理すると、熱的な凝集が起こるので、カーボン化の観点だけでなく、均一な表面カーボンコーティングの状況を踏まえた最適温度で、表面カーボンコーティング後の試料を熱処理すればよい。 However, if the sample after surface carbon coating is heat-treated at a high temperature, thermal agglomeration occurs, so the sample after surface carbon coating is not only at the point of carbonization but also at the optimum temperature based on the condition of uniform surface carbon coating. May be heat-treated.
　ここで、図２を参照して、電極材料１０を製造するための製造装置６０の構成例について説明する。この例では、負極材料を形成する場合であって、シリコン及び炭素（Ｓｉ／Ｃ）から成る複合体を負極用の電極材料１０を製造する場合を例に挙げる。 Here, with reference to FIG. 2, the structural example of the manufacturing apparatus 60 for manufacturing the electrode material 10 is demonstrated. In this example, a case where the negative electrode material is formed and a composite made of silicon and carbon (Si / C) is manufactured for the negative electrode material 10 will be described as an example.
　図２に示す製造装置６０は、超音波を利用したカーボン系物質２の表面修飾方法を実現する装置である。製造装置６０は超音波調整装置６１、石英セル６２及び冷却装置６３を備える。 The manufacturing apparatus 60 shown in FIG. 2 is an apparatus that realizes a surface modification method for the carbon-based material 2 using ultrasonic waves. The manufacturing apparatus 60 includes an ultrasonic adjustment device 61, a quartz cell 62, and a cooling device 63.
　石英セル６２には、超音波振動子６４が取り付けられている。超音波振動子６４は超音波調整装置６１に接続される。超音波調整装置６１では、超音波の周波数、その出力及びその照射時間が調整され設定される。周波数、出力及び照射時間は、例えば、超音波調整装置６１に設けられた調整用のボリューム等で設定する。石英セル６２には超音波振動子６４の他に撹拌子６５が設けられる。 An ultrasonic vibrator 64 is attached to the quartz cell 62. The ultrasonic transducer 64 is connected to the ultrasonic adjustment device 61. The ultrasonic adjustment device 61 adjusts and sets the ultrasonic frequency, its output, and its irradiation time. The frequency, output, and irradiation time are set by, for example, an adjustment volume provided in the ultrasonic adjustment device 61. The quartz cell 62 is provided with a stirring bar 65 in addition to the ultrasonic vibrator 64.
　図中、３は芳香族系有機溶媒であり、この例では、透明無色のｏ－ジクロロベンゼン（以下でｏ－ＤＣＢ３ともいう）が使用される。活物質１は、電極材料を構成する。本実施形態で、表面コーティングのターゲットとなる活物質１の一例として、Ｓｉナノ粒子４が採用される。ターゲットとなる活物質１はＳｉナノ粒子４に限られない。例えば、負極活物質として利用できるものを挙げるとすれば、活物質１は、ＳｎなどのＬｉと合金を形成する物質、ＳｉＯx（０＜x＜２）などの酸化物、ＮｂやＦｅやＴｉなどの金属酸化物、金属窒化物、金属硫化物であってもよい。 In the figure, reference numeral 3 denotes an aromatic organic solvent. In this example, transparent colorless o-dichlorobenzene (hereinafter also referred to as o-DCB3) is used. The active material 1 constitutes an electrode material. In this embodiment, Si nanoparticles 4 are employed as an example of the active material 1 that is a target for surface coating. The target active material 1 is not limited to the Si nanoparticles 4. For example, if what can be utilized as a negative electrode active material is given, the active material 1 is a material that forms an alloy with Li such as Sn, an oxide such as SiOx (0 <x <2), Nb, Fe, Ti, or the like. Metal oxides, metal nitrides, and metal sulfides may be used.
　冷却装置６３は、上部開放容器６６及び熱交換器６７を有している。上部開放容器６６には水５が入れられている。上部開放容器６６の内部には、石英セル６２の下方部分が配置されて、石英セル６２の下方部分が冷却される。上部開放容器６６には熱交換器６７が設けられている。熱交換器６７には冷却用の媒体、例えば、冷却水６が導入（循環）される。石英セル６２内で超音波振動子６４により超音波を照射し続けると石英セル６２内の溶液温度が上昇する。そこで、超音波振動子６４の劣化を防止するために、例えば、水５の温度を５℃に維持するようになされる。これらにより、超音波を利用したカーボン系物質２の表面修飾方法を実現する製造装置６０を構成する。 The cooling device 63 has an upper open container 66 and a heat exchanger 67. Water 5 is placed in the upper open container 66. A lower portion of the quartz cell 62 is disposed inside the upper open container 66, and the lower portion of the quartz cell 62 is cooled. A heat exchanger 67 is provided in the upper open container 66. A cooling medium, for example, cooling water 6 is introduced (circulated) into the heat exchanger 67. When the ultrasonic vibrator 64 continues to irradiate ultrasonic waves in the quartz cell 62, the solution temperature in the quartz cell 62 rises. Therefore, in order to prevent deterioration of the ultrasonic transducer 64, for example, the temperature of the water 5 is maintained at 5 ° C. By these, the manufacturing apparatus 60 which implement | achieves the surface modification method of the carbonaceous material 2 using an ultrasonic wave is comprised.
　続いて、図３を参照して、本発明に係るカーボン系物質２による活物質の表面修飾方法について説明をする。本発明に係るカーボン系物質２による活物質の表面修飾方法によれば、ｏ－ジクロロベンゼン中に、活物質１としてＳｉナノ粒子を加え、超音波照射することにより、Ｓｉナノ粒子表面をナノメートルオーダーの厚みのカーボン系物質２でコーティングしてＳｉ／Ｃ複合体を得る。このＳｉ／Ｃ複合体は、Ｓｉナノ粒子／カーボン複合体から成る試料である。 Subsequently, the surface modification method of the active material with the carbon-based material 2 according to the present invention will be described with reference to FIG. According to the surface modification method of the active material by the carbon-based material 2 according to the present invention, Si nanoparticle is added as the active material 1 in o-dichlorobenzene, and the surface of the Si nanoparticle is nanometer by irradiating with ultrasonic waves. An Si / C composite is obtained by coating with a carbon-based material 2 having an order thickness. This Si / C composite is a sample composed of a Si nanoparticle / carbon composite.
　この例では、２００［ｍＬ］のｏ－ＤＣＢ３に、仕込み量として１００～１５０［ｍｇ］のＳｉナノ粒子（３０～５０［ｎｍ］）の粉体を混合した。そして、アルゴン（Ａｒ）雰囲気で、攪拌下、次の照射件の下で超音波を照射した。照射条件は、超音波の出力が２００～３００［Ｗ］、その周波数が４０ｋＨｚ及び、その照射時間が０～９時間（以下で［ｈ］と表記）とした。 In this example, powder of 100 to 150 [mg] Si nanoparticles (30 to 50 [nm]) was mixed with 200 [mL] o-DCB3. Then, in an argon (Ar) atmosphere, ultrasonic waves were irradiated under stirring under the following irradiation conditions. The irradiation conditions were an ultrasonic output of 200 to 300 [W], a frequency of 40 kHz, and an irradiation time of 0 to 9 hours (hereinafter referred to as [h]).
　これらを表面修飾条件にして、まず、図３に示す工程＃１で、石英セル６２内に２００［ｍＬ］のｏ－ＤＣＢ３を入れると共に、仕込み量（導入量）＝１００～１５０［ｍｇ］のＳｉナノ粒子の粉体を加えて（混合して）、雰囲気をＡｒ置換した。Ａｒ置換では当該混合雰囲気がＡｒ雰囲気に置き換えられる。以下でｏ－ＤＣＢ３内にＳｉナノ粒子４が仕込まれたものを試料(SAMPLE)とした。 With these as surface modification conditions, first, in Step # 1 shown in FIG. 3, 200 [mL] of o-DCB3 is placed in the quartz cell 62, and the charged amount (introduced amount) = 100 to 150 [mg]. Si nano-particle powder was added (mixed) to replace the atmosphere with Ar. In the Ar substitution, the mixed atmosphere is replaced with an Ar atmosphere. Hereinafter, a sample (SAMPLE) in which Si nanoparticles 4 were charged in o-DCB3 was used.
　次に、工程＃２で試料の超音波処理を行った。この例では、超音波の出力が２００［Ｗ］及び３００［Ｗ］の２通りについて、照射時間を３［ｈ］～９［ｈ］に設定した。芳香族系有機溶媒に超音波を照射すると黒くなることは古くより知られている。Ｓｉナノ粒子４をｏ－ＤＣＢ３に分散させ、超音波の照射を開始した。超音波照射を開始して３０分経過した後、無色透明のｏ－ＤＣＢ３が黄色に変化した。 Next, the sample was sonicated in step # 2. In this example, the irradiation time was set to 3 [h] to 9 [h] for two types of ultrasonic output, 200 [W] and 300 [W]. It has long been known that when an aromatic organic solvent is irradiated with ultrasonic waves, it becomes black. Si nanoparticles 4 were dispersed in o-DCB3 and ultrasonic irradiation was started. After 30 minutes from the start of ultrasonic irradiation, the colorless and transparent o-DCB3 turned yellow.
　石英セル６２内では、ｏ－ＤＣＢ３が黄色に変色した後、数時間を経過した後に黒色に変化した。このとき、ｏ－ＤＣＢ３のラジカル反応により、有機溶媒分子が重合・カーボン化し、これにより生じたカーボン系物質２がＳｉナノ粒子４（活物質１）を表面処理した。後述するようにＳｉナノ粒子４の表面から炭素Ｃを検出することができた。ここに、Ｓｉナノ粒子４を含む黒色に変化した溶液が得られた。 In the quartz cell 62, o-DCB3 turned yellow and then turned black after several hours. At this time, the organic solvent molecules were polymerized and carbonized by the radical reaction of o-DCB3, and the resulting carbon-based material 2 surface-treated the Si nanoparticles 4 (active material 1). As described later, carbon C could be detected from the surface of the Si nanoparticles 4. Here, a black-colored solution containing the Si nanoparticles 4 was obtained.
　更に、工程＃３で遠心分離器を用いて試料の遠心分離を行った。分離条件は、遠心分離器の回転数を１００００［ｒｐｍ］に設定し、その分離時間を１時間とした。Ｓｉナノ粒子４を含む黒色に変化した溶液を１００００［ｒｐｍ］で、１時間遠心分離して沈殿物を回収した。その後、工程＃４で、先に回収された試料を温度１００［℃］により乾燥した。この乾燥処理により、高温度（例えば、２００［℃］～６００［℃］）による熱処理を行う前のＳｉナノ粒子４を含む黒色の試料が得られた。 Furthermore, the sample was centrifuged using a centrifuge in step # 3. Separation conditions were set such that the rotational speed of the centrifuge was set to 10,000 [rpm] and the separation time was 1 hour. The black solution containing the Si nanoparticles 4 was centrifuged at 10,000 [rpm] for 1 hour to collect the precipitate. Thereafter, in step # 4, the previously collected sample was dried at a temperature of 100 [° C.]. By this drying treatment, a black sample containing Si nanoparticles 4 before heat treatment at a high temperature (for example, 200 [° C.] to 600 [° C.]) was obtained.
　更に、工程＃５で熱処理を行う場合と、熱処理を行わない場合とで工程を分岐した。熱処理を行わない場合は、工程＃６に移行して、熱処理前の試料に表記を付す表記処理を実行した。ここで、上記工程＃４までの処理を経験した場合に「Ｃ」を最初（ヘッド）に付し、Ｓｉナノ粒子４の仕込み量をＸ［ｍｇ］とし、超音波照射時間をＹ［ｈ］とし、超音波出力をＺ［Ｗ］としたとき、熱処理を行わない試料を（１）式、すなわち、
　　　　　　　　　Ｃ－Ｓｉ（Ｘ）Ｙ［ｈ］Ｚ［Ｗ］・・・・・（１）
と表記して、後述の各実施例において電気化学分析に供した。 Furthermore, the process was branched depending on whether the heat treatment was performed in Step # 5 or not. When heat treatment is not performed, the process proceeds to step # 6, and a notation process is performed in which a notation is given to the sample before the heat treatment. Here, when experiencing the process up to the step # 4, “C” is added to the head (head), the charged amount of the Si nanoparticles 4 is X [mg], and the ultrasonic irradiation time is Y [h]. And when the ultrasonic output is Z [W], a sample not subjected to heat treatment is expressed by equation (1), that is,
C-Si (X) Y [h] Z [W] (1)
And was subjected to electrochemical analysis in each of the examples described later.
　試料の熱処理を行う場合は、工程＃７に移行して、カーボン系物質２で表面処理されたＳｉナノ粒子４（活物質１）を熱処理した。熱処理条件は、電気管状炉で、昇温速度が１０　℃／ｍｉｎで、温度が６００［℃］、熱処理時間が４時間保持、Ａｒ雰囲気とした。熱処理後のＳｉナノ粒子４は、熱処理前のＳｉナノ粒子４に比べて、より高容量を示すと共に高レート特性が得られた。 When performing heat treatment of the sample, the process proceeds to step # 7, and the Si nanoparticles 4 (active material 1) surface-treated with the carbon-based material 2 are heat-treated. The heat treatment conditions were an electric tubular furnace, a heating rate of 10 ° C./min, a temperature of 600 [° C.], a heat treatment time of 4 hours, and an Ar atmosphere. The Si nanoparticles 4 after the heat treatment showed higher capacity and higher rate characteristics than the Si nanoparticles 4 before the heat treatment.
　その後、工程＃８で熱処理後の試料に表記を付す表記処理を実行した。ここでも、工程＃４までの処理を経験した場合に「Ｃ」を最初に付した。Ｓｉナノ粒子４の仕込み量をＸ［ｍｇ］（式中の［ｍｇ］を省略する）とし、超音波照射時間をＹ［ｈ］とし、その出力をＺ［Ｗ］とし、熱処理時の温度をＨ［℃］（式中の［℃］を省略する）としたとき、熱処理後の試料を（２）式、すなわち、
　　　　　　　　Ｃ－Ｓｉ（Ｘ）Ｙ［ｈ］Ｚ［Ｗ］－Ｈ・・・・（２）
と表記して、後述の各実施例において電気化学分析に供した。 Then, the notation process which attaches description to the sample after heat processing in process # 8 was performed. Again, “C” was added first when experiencing the process up to step # 4. The charged amount of Si nanoparticles 4 is X [mg] ([mg] in the formula is omitted), the ultrasonic irradiation time is Y [h], the output is Z [W], and the temperature during heat treatment is When H [° C.] ([° C.] in the formula is omitted), the sample after the heat treatment is expressed by the formula (2), that is,
C-Si (X) Y [h] Z [W] -H (2)
And was subjected to electrochemical analysis in each of the examples described later.
　本発明者らは、カーボン系物質２の修飾状態に関して、ＴＥＭ観察、ＸＰＳ、ラマン分光分析、ＸＲＤ、元素分析、ＴＧ測定、ＥＤＸにより分析を行った。Ｓｉ結晶構造を保持しつつカーボン系物質２による表面修飾、粒子間隙への修飾を確認した。 The present inventors analyzed the modified state of the carbon-based material 2 by TEM observation, XPS, Raman spectroscopic analysis, XRD, elemental analysis, TG measurement, and EDX. While maintaining the Si crystal structure, the surface modification by the carbon-based material 2 and the modification to the particle gap were confirmed.
　ここで、図４を参照して、Ｃ－Ｓｉ（Ｘ）Ｙ［ｈ］Ｚ［Ｗ］試料等のＸＲＤパターンについて説明する。この例で、試料にＳｉナノ粒子４が存在しているか否かを調べるために、Ｃ－Ｓｉ（Ｘ）Ｙ［ｈ］Ｚ［Ｗ］試料等のＸＲＤ（Ｘ線回折）パターンを取得した。 Here, with reference to FIG. 4, an XRD pattern of a C-Si (X) Y [h] Z [W] sample or the like will be described. In this example, an XRD (X-ray diffraction) pattern of a C—Si (X) Y [h] Z [W] sample or the like was obtained in order to examine whether or not the Si nanoparticles 4 were present in the sample.
　その際に、Ｘ線回折装置（リガク　ＲＩＮＴ－２２００（線源：ＣｕＫα）製）を使用した。ＸＲＤ分析条件は、対陰極：ＣｕＫα、スキャンスピード：２．０［degree／min］、管電圧：４０［ｋＶ］、管電流：４０［ｍＡ］、サンプリング間隔：０．０１０［degree］とした。図４の左図及び右図において、縦軸はＸ線の回折強度（Intensity）であり、横軸はＸ線の入射角［２θ／degree（ＣｕＫα）］である。 At that time, an X-ray diffractometer (Rigaku RINT-2200 (source: CuKα)) was used. The XRD analysis conditions were as follows: counter cathode: CuKα, scan speed: 2.0 [degree / min], tube voltage: 40 [kV], tube current: 40 [mA], sampling interval: 0.010 [degree]. In the left diagram and the right diagram of FIG. 4, the vertical axis represents the X-ray diffraction intensity (Intensity), and the horizontal axis represents the X-ray incident angle [2θ / degree (CuKα)].
　図４の左図において、比較例１はコーティング処理無し（未修飾）のＳｉナノ粒子４のＸＲＤパターンである。実施例１はコーティング処理のみのＣ－Ｓｉ（１００）９［ｈ］２００［Ｗ］のＸＲＤパターンである。実施例２はコーティング処理のみのＣ－Ｓｉ（１５０）９［ｈ］３００［Ｗ］のＸＲＤパターンである。実施例３はコーティング処理のみのＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］のＸＲＤパターンである。実施例４はコーティング処理のみのＣ－Ｓｉ（１００）３［ｈ］３００［Ｗ］のＸＲＤパターンである。 4, Comparative Example 1 is an XRD pattern of Si nanoparticles 4 without coating treatment (unmodified). Example 1 is an XRD pattern of C—Si (100) 9 [h] 200 [W] only by coating treatment. Example 2 is an XRD pattern of C—Si (150) 9 [h] 300 [W] only by coating treatment. Example 3 is an XRD pattern of C—Si (100) 9 [h] 300 [W] only by coating treatment. Example 4 is an XRD pattern of C—Si (100) 3 [h] 300 [W] only by coating treatment.
　図４の右図において、比較例２はコーティング処理無し（未修飾）＋熱処理６００［℃］のＳｉナノ粒子４のＸＲＤパターンである。実施例５はコーティング処理＋熱処理６００［℃］のＣ－Ｓｉ（１００）９［ｈ］２００［Ｗ］－Ｈ試料のＸＲＤパターンである。実施例６はコーティング処理＋熱処理６００［℃］のＣ－Ｓｉ（１５０）９［ｈ］３００［Ｗ］－Ｈ試料のＸＲＤパターンである。実施例７はコーティング処理＋熱処理６００［℃］のＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］－Ｈ試料のＸＲＤパターンである。実施例８はコーティング処理＋熱処理６００［℃］のＣ－Ｓｉ（１００）３［ｈ］３００［Ｗ］－Ｈ試料のＸＲＤパターンである。 4, Comparative Example 2 is an XRD pattern of Si nanoparticles 4 without coating treatment (unmodified) + heat treatment 600 [° C.]. Example 5 is an XRD pattern of a C—Si (100) 9 [h] 200 [W] —H sample subjected to a coating treatment and a heat treatment of 600 [° C.]. Example 6 is an XRD pattern of a C—Si (150) 9 [h] 300 [W] —H sample subjected to a coating treatment and a heat treatment of 600 [° C.]. Example 7 is an XRD pattern of a C—Si (100) 9 [h] 300 [W] —H sample subjected to coating treatment + heat treatment 600 [° C.]. Example 8 is an XRD pattern of a C—Si (100) 3 [h] 300 [W] —H sample subjected to coating treatment + heat treatment 600 [° C.].
　各超音波処理条件で得た試料（実施例１～８）において、いずれも、未修飾のＳｉナノ粒子４と同じ回折ピークが観測され、Ｓｉ結晶構造が保持されていることが確認できた。すなわち、比較例１によれば、２θ／degree（ＣｕＫα）＝２８，４７，５６，６９，７７，８８付近に各々ピークを有していた。コーティング処理後の実施例１～４においても、各々対応する位置にピークを有するパターンが取得できた。 In the samples (Examples 1 to 8) obtained under the respective ultrasonic treatment conditions, the same diffraction peaks as those of the unmodified Si nanoparticles 4 were observed, and it was confirmed that the Si crystal structure was retained. That is, according to the comparative example 1, it had peaks in the vicinity of 2θ / degree (CuKα) = 28, 47, 56, 69, 77, 88. Also in Examples 1 to 4 after the coating treatment, patterns having peaks at corresponding positions could be obtained.
　また、コーティング処理＋熱処理６００［℃］後の各試料（実施例５～８）においても、各々対応する位置にピークを有するパターンを取得できた。実施例５～８では、実施例１～４と同様に、Ｓｉ結晶構造が保持されていることが確認でき、Ｓｉナノ粒子４を同定できた。 Also, in each sample (Examples 5 to 8) after the coating treatment and the heat treatment 600 [° C.], a pattern having a peak at each corresponding position could be obtained. In Examples 5 to 8, as in Examples 1 to 4, it was confirmed that the Si crystal structure was retained, and Si nanoparticles 4 could be identified.
　続いて、図５を参照して、Ｃ－Ｓｉ（Ｘ）Ｙ［ｈ］Ｚ［Ｗ］試料のラマンスペクトルについて説明する。この例で、カーボン系物質２が良好にコーティングされているか否かを調べるために、Ｃ－Ｓｉ（Ｘ）Ｙ［ｈ］Ｚ［Ｗ］試料等のラマンスペクトルを取得した。その際に、ラマンスペクトル装置（日本分光ＪＡＳＣＯ　ＲＭＰ－２１０（レーザー光波長：５３２［ｎｍ］））を使用した。取得条件は、露光時間が１０sec（秒）で、積算回数が２０回で、波数が１００～２０００［ｃｍ-1］とした。 Next, the Raman spectrum of the C—Si (X) Y [h] Z [W] sample will be described with reference to FIG. In this example, a Raman spectrum of a C—Si (X) Y [h] Z [W] sample or the like was acquired in order to examine whether or not the carbon-based material 2 was satisfactorily coated. At that time, a Raman spectrum apparatus (JASCO JASCO RMP-210 (laser light wavelength: 532 [nm])) was used. The acquisition conditions were an exposure time of 10 sec (seconds), an integration count of 20 times, and a wave number of 100 to 2000 [cm −1 ].
　図５の左図及び右図において、縦軸は強度（Intensity：［Arb.　unit］）で、横軸はラマンシフト（Raman　shift：［ｃｍ-1］である。なお、図５の左図は、４００～１８００［ｃｍ-1］領域のラマンスペクトルを示し、図５の右図は１３００～１８００［ｃｍ-1］領域を拡大したラマンスペクトルを示している。 5, the vertical axis represents intensity (Intensity: [Arb. Unit]), and the horizontal axis represents Raman shift ([cm −1 ]). , 400 to 1800 [cm −1 ] region, and the right figure of FIG. 5 shows an enlarged Raman spectrum of 1300 to 1800 [cm −1 ] region.
　図５の左図において、比較例３はコーティング処理無し（未修飾）のＳｉナノ粒子４のラマンスペクトルである。実施例９はコーティング処理のみのＣ－Ｓｉ（１００）９［ｈ］２００［Ｗ］のラマンスペクトルである。実施例１０はコーティング処理のみのＣ－Ｓｉ（１５０）９［ｈ］３００［Ｗ］のラマンスペクトルである。実施例１１はコーティング処理のみのＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］のラマンスペクトルである。実施例１２はコーティング処理のみのＣ－Ｓｉ（１００）３［ｈ］３００［Ｗ］のラマンスペクトルである。 5, Comparative Example 3 is a Raman spectrum of the Si nanoparticles 4 without coating treatment (unmodified). Example 9 is a Raman spectrum of C—Si (100) 9 [h] 200 [W] only by coating treatment. Example 10 is a Raman spectrum of C—Si (150) 9 [h] 300 [W] only by coating treatment. Example 11 is a Raman spectrum of C—Si (100) 9 [h] 300 [W] only by coating treatment. Example 12 is a Raman spectrum of C—Si (100) 3 [h] 300 [W] only by coating treatment.
　図５の右図に示す１３００～１８００［ｃｍ-1］領域の拡大例において、比較例３はコーティング処理無し（未修飾）のＳｉナノ粒子４のラマンスペクトルである。比較例３では、カーボン系物質２が確認されない。実施例９はコーティング処理のみのＣ－Ｓｉ（１００）９［ｈ］２００［Ｗ］のラマンスペクトルである。実施例１０はコーティング処理のみのＣ－Ｓｉ（１５０）９［ｈ］３００［Ｗ］のラマンスペクトルである。実施例１１はコーティング処理のみのＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］のラマンスペクトルである。実施例１２はコーティング処理のみのＣ－Ｓｉ（１００）３［ｈ］３００［Ｗ］のラマンスペクトルである。 In the enlarged example of the 1300 to 1800 [cm −1 ] region shown in the right diagram of FIG. 5, Comparative Example 3 is a Raman spectrum of the Si nanoparticles 4 without coating treatment (unmodified). In Comparative Example 3, the carbon-based material 2 is not confirmed. Example 9 is a Raman spectrum of C—Si (100) 9 [h] 200 [W] only by coating treatment. Example 10 is a Raman spectrum of C—Si (150) 9 [h] 300 [W] only by coating treatment. Example 11 is a Raman spectrum of C—Si (100) 9 [h] 300 [W] only by coating treatment. Example 12 is a Raman spectrum of C—Si (100) 3 [h] 300 [W] only by coating treatment.
　比較例３及び実施例９～１２において、ラマンシフト５２０［ｃｍ-1］付近のシャープなピークはＳｉ結晶の存在を示している。このことから、Ｓｉナノ粒子４が存在していることがわかった。実施例９～１２に示す超音波照射試料に見られるラマンシフト１５８０，１３６０［ｃｍ-1］付近のピークは、カーボン由来のピークである。いずれの超音波照射条件においても、Ｓｉナノ粒子４＋カーボン系物質２の複合体が生成されていることが確認できた。 In Comparative Example 3 and Examples 9 to 12, a sharp peak near the Raman shift 520 [cm −1 ] indicates the presence of Si crystals. From this, it was found that Si nanoparticles 4 were present. The peaks in the vicinity of the Raman shifts 1580 and 1360 [cm −1 ] seen in the ultrasonic irradiation samples shown in Examples 9 to 12 are carbon-derived peaks. It was confirmed that a composite of Si nanoparticles 4 + carbon-based material 2 was generated under any ultrasonic irradiation condition.
　なお、図５の右図において、実施例９～１２におけるラマンシフト１５８０［ｃｍ-1］付近のピーク（Ｇバンド）は、グラファイト性カーボンである。実施例９～１２におけるラマンシフト１３６０ｃｍ-1付近のピーク（Ｄバンド）は、アモルファス性カーボン由来のピークである。すなわち、実施例９～１２において、カーボン系物質２が残っていることがわかった。 In the right diagram of FIG. 5, the peak (G band) in the vicinity of the Raman shift 1580 [cm −1 ] in Examples 9 to 12 is graphitic carbon. In Examples 9 to 12, the peak (D band) near the Raman shift of 1360 cm −1 is a peak derived from amorphous carbon. That is, it was found that in Examples 9 to 12, the carbon-based material 2 remained.
　続いて、図６を参照して、Ｃ－Ｓｉ（Ｘ）Ｙ［ｈ］Ｚ［Ｗ］－Ｈ試料のラマンスペクトルについて説明する。この例で、６００［℃］の熱処理後のカーボン系物質２が良好に残存しているか否かを調べるために、Ｃ－Ｓｉ（Ｘ）Ｙ［ｈ］Ｚ［Ｗ］－Ｈ試料等のラマンスペクトルを取得した。その際のラマンスペクトル装置及び取得条件は、上述した通りである。 Subsequently, the Raman spectrum of the C—Si (X) Y [h] Z [W] —H sample will be described with reference to FIG. In this example, Raman such as a C—Si (X) Y [h] Z [W] —H sample is used to examine whether the carbon-based material 2 after heat treatment at 600 [° C.] remains excellent. A spectrum was acquired. The Raman spectrum apparatus and acquisition conditions at that time are as described above.
　図６の左図において、比較例４はコーティング処理無し（未修飾）＋熱処理６００［℃］のＳｉナノ粒子４のラマンスペクトルである。実施例１３はコーティング処理＋熱処理６００［℃］のＣ－Ｓｉ（１００）９［ｈ］２００［Ｗ］－Ｈ試料のラマンスペクトルである。実施例１４はコーティング処理＋熱処理６００［℃］のＣ－Ｓｉ（１５０）９［ｈ］３００［Ｗ］－Ｈ試料のラマンスペクトルである。実施例１５はコーティング処理＋熱処理６００［℃］のＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］－Ｈ試料のラマンスペクトルである。実施例１６はコーティング処理＋熱処理６００［℃］のＣ－Ｓｉ（１００）３［ｈ］３００［Ｗ］－Ｈ試料のラマンスペクトルである。 6, Comparative Example 4 is a Raman spectrum of Si nanoparticles 4 without coating treatment (unmodified) + heat treatment 600 [° C.]. Example 13 is a Raman spectrum of a C—Si (100) 9 [h] 200 [W] —H sample subjected to a coating treatment and a heat treatment of 600 [° C.]. Example 14 is a Raman spectrum of a C—Si (150) 9 [h] 300 [W] —H sample subjected to a coating treatment and a heat treatment of 600 [° C.]. Example 15 is a Raman spectrum of a C—Si (100) 9 [h] 300 [W] —H sample subjected to a coating treatment and a heat treatment of 600 [° C.]. Example 16 is a Raman spectrum of a C—Si (100) 3 [h] 300 [W] —H sample subjected to coating treatment + heat treatment 600 [° C.].
　図６の右図に示す１３００～１８００［ｃｍ-1］領域において、比較例４はコーティング処理無し（未修飾）＋熱処理６００［℃］のＳｉナノ粒子４のラマンスペクトルである。比較例４では、カーボン系物質２が確認されなかった。実施例１３はコーティング処理＋熱処理６００［℃］のＣ－Ｓｉ（１００）９［ｈ］２００［Ｗ］－Ｈ試料のラマンスペクトルである。実施例１４はコーティング処理＋熱処理６００［℃］のＣ－Ｓｉ（１５０）９［ｈ］３００［Ｗ］－Ｈ試料のラマンスペクトルである。実施例１５はコーティング処理＋熱処理６００［℃］のＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］－Ｈ試料のラマンスペクトルである。実施例１６はコーティング処理＋熱処理６００［℃］のＣ－Ｓｉ（１００）３［ｈ］３００［Ｗ］－Ｈ試料のラマンスペクトルである。 In the 1300-1800 [cm −1 ] region shown in the right diagram of FIG. 6, Comparative Example 4 is a Raman spectrum of the Si nanoparticles 4 without coating treatment (unmodified) + heat treatment 600 [° C.]. In Comparative Example 4, the carbon-based material 2 was not confirmed. Example 13 is a Raman spectrum of a C—Si (100) 9 [h] 200 [W] —H sample subjected to a coating treatment and a heat treatment of 600 [° C.]. Example 14 is a Raman spectrum of a C—Si (150) 9 [h] 300 [W] —H sample subjected to a coating treatment and a heat treatment of 600 [° C.]. Example 15 is a Raman spectrum of a C—Si (100) 9 [h] 300 [W] —H sample subjected to a coating treatment and a heat treatment of 600 [° C.]. Example 16 is a Raman spectrum of a C—Si (100) 3 [h] 300 [W] —H sample subjected to coating treatment + heat treatment 600 [° C.].
　熱処理後の比較例４及び実施例１３～１６においても、ラマンシフト５２０［ｃｍ-1］付近のシャープなピークがＳｉ結晶の存在を示し、Ｓｉナノ粒子４が存在していることがわかった。また、実施例１３～１６に示す超音波照射＋熱処理後試料では、ラマンシフト１５８０，１３６０［ｃｍ-1］付近のカーボン由来のピークが確認された。いずれの超音波照射条件＋熱処理条件においても、Ｓｉナノ粒子４＋カーボン系物質２の複合体が生成されていることが確認できた。 In Comparative Example 4 and Examples 13 to 16 after the heat treatment, it was found that a sharp peak near the Raman shift 520 [cm −1 ] indicates the presence of Si crystals, and Si nanoparticles 4 are present. In addition, in the samples after ultrasonic irradiation and heat treatment shown in Examples 13 to 16, carbon-derived peaks in the vicinity of Raman shifts 1580 and 1360 [cm −1 ] were confirmed. It was confirmed that a composite of Si nanoparticles 4 + carbon-based material 2 was generated under any ultrasonic irradiation condition + heat treatment condition.
　上述したカーボン系物質２の修飾量は、超音波照射条件（Ｓｉ分散量、出力、時間など）に依存する。そこで、図７を参照して、超音波照射条件と表面修飾量との関係について説明する。この例では、空気中での熱重量（Thermogravimetric　analysis：ＴＧ）分析により、温度を変化させながら、あるいは一定の温度に保って、試料の重量変化を測定し、有機物部分の分解による重量変化から見積もったカーボン系物質２の修飾量を求めた。この結果から、図７の左図及び右図に示すように、カーボン系物質２の修飾量［ｗｔ％］と超音波照射時間[hour]との関係を作成した。 The amount of modification of the carbon-based material 2 described above depends on the ultrasonic irradiation conditions (Si dispersion amount, output, time, etc.). Then, with reference to FIG. 7, the relationship between ultrasonic irradiation conditions and a surface modification amount is demonstrated. In this example, thermogravimetric analysis (TG) analysis in air is used to measure the weight change of the sample while changing the temperature or at a constant temperature, and estimate it from the weight change due to the decomposition of the organic matter part. The amount of modification of the carbon-based material 2 was determined. From this result, as shown in the left and right diagrams of FIG. 7, the relationship between the modification amount [wt%] of the carbon-based material 2 and the ultrasonic irradiation time [hour] was created.
　図７の左図及び右図において、縦軸はカーボン系物質２の修飾量［ｗｔ％］である。横軸は超音波照射時間[hour]である。熱重量（ＴＧ）分析では、Ｃ－Ｓｉ（Ｘ）Ｙ［ｈ］Ｚ［Ｗ］試料の熱処理無しの場合とその熱処理有りの場合とで、カーボン系物質２の修飾量を比較した。 7, the vertical axis represents the modification amount [wt%] of the carbon-based material 2. The horizontal axis represents the ultrasonic irradiation time [hour]. In the thermogravimetric (TG) analysis, the modification amount of the carbon-based material 2 was compared between the C—Si (X) Y [h] Z [W] sample without heat treatment and the heat treatment.
　図７の左図において、熱処理前のＣ－Ｓｉ（Ｘ）Ｙ［ｈ］Ｚ［Ｗ］試料によれば、実施例１７が白抜き四角印でＣ－Ｓｉ（１００）３［ｈ］３００［Ｗ］の場合である。実施例１８は白抜き丸印でＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］の場合である。実施例１９は白抜き三角印でＣ－Ｓｉ（１５０）９［ｈ］３００［Ｗ］の場合である。実施例２０は白抜き菱形印でＣ－Ｓｉ（１００）９［ｈ］２００［Ｗ］の場合である。 In the left diagram of FIG. 7, according to the C—Si (X) Y [h] Z [W] sample before the heat treatment, Example 17 is a white square mark and C—Si (100) 3 [h] 300 [ W]. Example 18 is the case of C—Si (100) 9 [h] 300 [W] with white circles. Example 19 is a case of C-Si (150) 9 [h] 300 [W] with white triangle marks. Example 20 is a case where C—Si (100) 9 [h] 200 [W] is indicated by white diamond marks.
　実施例１７によれば、超音波照射時間が３[ｈ]で、カーボン系物質２の修飾量は１２［ｗｔ％］であった。実施例１８～２０によれば、超音波照射時間が９[ｈ]である。カーボン系物質２の修飾量は、実施例１８が約４０［ｗｔ％］であり、実施例１９が約５［ｗｔ％］であり、実施例２０が約１２［ｗｔ％］であった。 According to Example 17, the ultrasonic irradiation time was 3 [h], and the modification amount of the carbon-based material 2 was 12 [wt%]. According to Examples 18 to 20, the ultrasonic irradiation time is 9 [h]. The modification amount of the carbon-based material 2 was about 40 [wt%] in Example 18, about 5 [wt%] in Example 19, and about 12 [wt%] in Example 20.
　図７の右図において、熱処理後のＣ－Ｓｉ（Ｘ）Ｙ［ｈ］Ｚ［Ｗ］－Ｈ試料によれば、実施例２１が黒四角印でＣ－Ｓｉ（１００）３［ｈ］３００［Ｗ］－Ｈ試料の場合である。実施例２２は黒丸印でＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］－Ｈ試料の場合である。実施例２３は黒三角印でＣ－Ｓｉ（１５０）９［ｈ］３００［Ｗ］－Ｈ試料の場合である。実施例２４は黒菱形印でＣ－Ｓｉ（１００）９［ｈ］２００［Ｗ］－Ｈ試料の場合である。 In the right diagram of FIG. 7, according to the C—Si (X) Y [h] Z [W] —H sample after the heat treatment, Example 21 is a black square mark and C—Si (100) 3 [h] 300. This is the case of [W] -H sample. Example 22 is a case of a C—Si (100) 9 [h] 300 [W] —H sample indicated by black circles. Example 23 is a case of a C—Si (150) 9 [h] 300 [W] —H sample with black triangle marks. Example 24 is the case of a C—Si (100) 9 [h] 200 [W] —H sample with black rhombus marks.
　実施例２１によれば、超音波照射時間が３[ｈ]で、カーボン系物質２の修飾量は１０［ｗｔ％］であった。実施例２２～２４によれば、超音波照射時間が９[ｈ]である。カーボン系物質２の修飾量は、実施例２２が約３０［ｗｔ％］であり、実施例２３及び実施例２４が共に約８［ｗｔ％］であった。 According to Example 21, the ultrasonic irradiation time was 3 [h], and the modification amount of the carbon-based material 2 was 10 [wt%]. According to Examples 22 to 24, the ultrasonic irradiation time is 9 [h]. The modification amount of the carbon-based material 2 was about 30 [wt%] in Example 22, and about 8 [wt%] in both Example 23 and Example 24.
　このＴＧ分析によれば、Ｓｉ分散量（仕込み量）や、超音波出力を同じ条件（Ｃ－Ｓｉ（１００）Ｙ［ｈ］３００［Ｗ］）で比較すると、超音波照射時間と共に修飾量が増加した。超音波照射時間や超音波出力等を同じ条件（Ｃ－Ｓｉ（Ｘ）Ｙ［ｈ］３００［Ｗ］）で比較すると、Ｓｉ分散量が少ない方が修飾量が多かった。また、Ｓｉ分散量や、超音波照射時間を同じ条件（Ｃ－Ｓｉ（１００）９［ｈ］Ｚ［Ｗ］）で比較すると、超音波出力が大きい方が修飾量が多かった。 According to this TG analysis, when the amount of Si dispersion (preparation amount) and ultrasonic output are compared under the same conditions (C-Si (100) Y [h] 300 [W]), the modification amount increases with the ultrasonic irradiation time. Increased. When the ultrasonic irradiation time, ultrasonic output, etc. were compared under the same conditions (C—Si (X) Y [h] 300 [W]), the amount of modification was greater when the Si dispersion amount was smaller. Further, when the Si dispersion amount and the ultrasonic irradiation time were compared under the same conditions (C-Si (100) 9 [h] Z [W]), the amount of modification was larger when the ultrasonic output was larger.
　図７の左図に示した熱処理前と、図７の右図に示した熱処理後とを比較すると、熱処理により修飾量が減少するが、上述の超音波条件に依存する傾向は熱処理前後で同様となった。このことは、熱処理により、Ｈ／Ｃ及びＣｌ存在量が減少することから、カーボン化が更に進行していることと一致する。 When the heat treatment shown in the left diagram of FIG. 7 is compared with the heat treatment shown in the right diagram of FIG. 7, the amount of modification is reduced by the heat treatment, but the tendency depending on the above-described ultrasonic conditions is the same before and after the heat treatment. It became. This is consistent with the further progress of carbonization because the amount of H / C and Cl is reduced by heat treatment.
　ここで、Ｃ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料と、Ｃ－Ｓｉ（１００）９［ｈ］３００［Ｗ］－Ｈ試料との修飾の組成について比較した。まず、ＥＤＸ分析（ケイ光Ｘ線分析方法）により、ＳｉとＣｌとの相対モル数を調べて修飾の組成を分析した。Ｃ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料と、Ｃ－Ｓｉ（１００）９［ｈ］３００［Ｗ］－Ｈ試料とのＥＤＸ分析結果を表１に示した。 Here, the modification compositions of the C-Si (100) 9 [h] 300 [W] sample and the C-Si (100) 9 [h] 300 [W] -H sample were compared. First, the composition of the modification was analyzed by examining the relative number of moles of Si and Cl by EDX analysis (fluorescence X-ray analysis method). Table 1 shows the EDX analysis results of the C—Si (100) 9 [h] 300 [W] sample and the C—Si (100) 9 [h] 300 [W] —H sample.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１のコーティング＋熱処理前のＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料によれば、Ｓｉの相対モル数が８３．３９［ｍｏｌ％］であり、Ｃｌの相対モル数が１４．３４［ｍｏｌ％］であった。コーティング＋熱処理後のＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］－６００［℃］試料によれば、Ｓｉの相対モル数が９９．３３［ｍｏｌ％］であり、Ｃｌの相対モル数が０．００（ｍｏｌ％）であった。このＥＤＸ分析の結果、超音波処理＋熱処理前は共に塩素（Ｃｌ）が存在するが、超音波処理＋熱処理後は、熱処理によりＣｌ成分が除去されていることがわかった。 According to the sample of C—Si (100) 9 [h] 300 [W] before coating + heat treatment in Table 1, the relative mole number of Si is 83.39 [mol%], and the relative mole number of Cl is 14 .34 [mol%]. According to the sample of C—Si (100) 9 [h] 300 [W] -600 [° C.] after coating and heat treatment, the relative mole number of Si is 99.33 [mol%], and the relative mole number of Cl. Was 0.00 (mol%). As a result of this EDX analysis, it was found that chlorine (Cl) was present before both the ultrasonic treatment and the heat treatment, but the Cl component was removed by the heat treatment after the ultrasonic treatment and the heat treatment.
　次に、有機元素分析により、カーボン系物質２の組成を調べるために、炭素（Ｃ）、水素（Ｈ）及び窒素（Ｎ）の含有重量［ｗｔ％］を調べた。Ｃ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料と、Ｃ－Ｓｉ（１００）９［ｈ］３００［Ｗ］－Ｈ試料との有機元素分析結果を表２に示した。 Next, in order to investigate the composition of the carbon-based material 2 by organic elemental analysis, the content weight [wt%] of carbon (C), hydrogen (H) and nitrogen (N) was examined. Table 2 shows organic element analysis results of the C—Si (100) 9 [h] 300 [W] sample and the C—Si (100) 9 [h] 300 [W] —H sample.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表２のコーティング＋熱処理前のＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料（サンプル）によれば、Ｃの元素含有量が１９．３２［ｗｔ％］であり、Ｈの元素含有量が０．３９［ｗｔ％］であり、Ｎの元素含有量が０．００［ｗｔ％］であった。 According to the C—Si (100) 9 [h] 300 [W] sample (sample) before coating + heat treatment in Table 2, the element content of C is 19.32 [wt%] and the element content of H The amount was 0.39 [wt%], and the element content of N was 0.00 [wt%].
　コーティング＋熱処理後のＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］－６００［℃］試料によれば、Ｃの元素含有量が１８．５１［ｗｔ％］であり、Ｈの元素含有量が０．１４［ｗｔ％］であり、Ｎの元素含有量が０．００［ｗｔ％］であった。 According to the C + Si (100) 9 [h] 300 [W] -600 [° C.] sample after coating and heat treatment, the C element content was 18.51 [wt%], and the H element content Was 0.14 [wt%], and the elemental content of N was 0.00 [wt%].
　一般に、カーボン化の意味はカーボン系物質中のＣの割合が高くなることをいう。Ｃ－Ｃ結合よりもＣ＝Ｃ結合が増えると、Ｈの割合が減り、通常のカーボン化はベンゼン骨格が繋がったグラフェン構造が形成されて行くため、この数値がカーボン化の目安に利用される。 Generally, the meaning of carbonization means that the ratio of C in the carbon-based material is increased. When the C = C bond increases compared to the C—C bond, the ratio of H decreases, and the normal carbonization forms a graphene structure linked to the benzene skeleton, so this figure is used as a guide for carbonization .
　有機元素分析によれば、コーティング（熱処理なし）処理試料において、Ｈ／Ｃの重量比が０．０２０であるのに対し、コーティング＋熱処理後はＨ／Ｃ比は０．００８に減少しており、カーボン化が進行していることがわかった。カーボン系物質２のコーティング処理により、Ｓｉナノ粒子４上にカーボン成分が析出された。コーティング処理後も、Ｓｉ結晶相は保持されていた。熱処理によりカーボン化が更に進行していることがわかった。 According to the organic element analysis, the H / C weight ratio in the coating (without heat treatment) sample was 0.020, whereas the H / C ratio decreased to 0.008 after coating + heat treatment. It was found that carbonization was progressing. A carbon component was deposited on the Si nanoparticles 4 by the coating treatment of the carbon-based material 2. Even after the coating treatment, the Si crystal phase was retained. It was found that the carbonization was further advanced by the heat treatment.
　続いて、図８の左図及び右図を参照して、未修飾のＳｉナノ粒子４及びＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料のＴＥＭ（透過型電子顕微鏡）観察について説明する。図８の左図に示す未修飾のＳｉナノ粒子４のＴＥＭ写真によれば、電極材料１０として用いたＳｉナノ粒子４は、３０－５０ｎｍの平均粒子径を有していた。Ｓｉナノ粒子４は、結晶構造であること示す格子像が見られた。コーティング処理前のＳｉ結晶相（格子結晶）表面に、厚み１～２ｎｍ程度のＳｉＯ2層が観測された。図８の左図に示す写真の中に、ＳｉＯ2層の拡大図も示している。 Next, with reference to the left and right diagrams of FIG. 8, TEM (transmission electron microscope) observation of the unmodified Si nanoparticles 4 and the C—Si (100) 9 [h] 300 [W] sample will be described. To do. According to the TEM photograph of the unmodified Si nanoparticles 4 shown in the left diagram of FIG. 8, the Si nanoparticles 4 used as the electrode material 10 had an average particle diameter of 30-50 nm. A lattice image showing that the Si nanoparticles 4 had a crystal structure was observed. A SiO 2 layer having a thickness of about 1 to 2 nm was observed on the surface of the Si crystal phase (lattice crystal) before the coating treatment. An enlarged view of the SiO 2 layer is also shown in the photograph shown on the left side of FIG.
　図８の右図に示すＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料のＴＥＭ写真によれば、Ｓｉ結晶相（Ｓｉナノ粒子）の表面が厚み５ｎｍ程度のアモルファス層で覆われていた。カーボン系物質２は厚み５ｎｍ程度を有し、Ｓｉ結晶相の表面をコーティングしていることがわかった。図８の右図の中に、カーボン系物質２の拡大図を示している。この試料によれば、ＸＰＳ分析でＳｉＯ2層も観測された。 According to the TEM photograph of the C—Si (100) 9 [h] 300 [W] sample shown on the right side of FIG. 8, the surface of the Si crystal phase (Si nanoparticles) is covered with an amorphous layer having a thickness of about 5 nm. It was. It was found that the carbon-based material 2 has a thickness of about 5 nm and coats the surface of the Si crystal phase. An enlarged view of the carbon-based material 2 is shown in the right diagram of FIG. According to this sample, an SiO 2 layer was also observed by XPS analysis.
　コーティング処理後のＳｉ結晶相粒度分布によれば、厚み１５～２０ｎｍ程度の粒子径が増加していた。このことから、平均として厚み５～１０ｎｍ程度のコーティング層が形成されていると考えられる。このように、Ｓｉナノ粒子４の表面にナノメートルオーダーの厚みのカーボン系物質２を均一に形成できた。 According to the Si crystal phase particle size distribution after the coating treatment, the particle diameter of about 15 to 20 nm in thickness was increased. From this, it is considered that a coating layer having an average thickness of about 5 to 10 nm is formed. Thus, the carbonaceous material 2 having a thickness of nanometer order could be uniformly formed on the surface of the Si nanoparticles 4.
　ここで、図９を参照して、表面コーティング前後における試料の平均粒子径の比較例について説明する。図９の上図及び下図に示す粒度分布図において、縦軸は当該粒子径を示す試料（Ｓｉナノ粒子４）の割合［％］であり、横軸は試料の平均粒子径［ｎｍ］である。 Here, a comparative example of the average particle diameter of the sample before and after the surface coating will be described with reference to FIG. In the particle size distribution chart shown in the upper and lower diagrams of FIG. 9, the vertical axis represents the ratio [%] of the sample (Si nanoparticle 4) showing the particle diameter, and the horizontal axis represents the average particle diameter [nm] of the sample. .
　図９の上図に示す表面コーティング前における試料の平均粒子径の割合によれば、平均粒子径１０～２０［ｎｍ］の試料の割合が８［％］であり、平均粒子径２０～３０［ｎｍ］の試料の割合が３５［％］であり、平均粒子径３０～４０［ｎｍ］の試料の割合も３５［％］であり、平均粒子径４０～５０［ｎｍ］の試料の割合が１６［％］であり、平均粒子径５０～６０［ｎｍ］の試料の割合が５［％］であり、平均粒子径６０～７０［ｎｍ］の試料の割合も３［％］であった。 According to the ratio of the average particle diameter of the sample before surface coating shown in the upper diagram of FIG. 9, the ratio of the sample having an average particle diameter of 10 to 20 [nm] is 8 [%], and the average particle diameter of 20 to 30 [ nm] is 35 [%], the average particle size is 30 to 40 [nm], the sample is 35 [%], and the average particle size is 40 to 50 [nm]. [%], The ratio of samples having an average particle diameter of 50 to 60 [nm] was 5 [%], and the ratio of samples having an average particle diameter of 60 to 70 [nm] was also 3 [%].
　図９の下図に示す表面コーティング後における試料の平均粒子径の割合によれば、平均粒子径２０～３０［ｎｍ］の試料の割合が１［％］であり、平均粒子径３０～４０［ｎｍ］の試料の割合も５［％］であり、平均粒子径４０～５０［ｎｍ］の試料の割合が１３［％］であり、平均粒子径５０～６０［ｎｍ］の試料の割合が３３［％］であり、平均粒子径６０～７０［ｎｍ］の試料の割合が２５［％］であり、平均粒子径７０～８０［ｎｍ］の試料の割合が１６［％］であり、平均粒子径８０～９０［ｎｍ］の試料の割合も５［％］であった。 According to the ratio of the average particle diameter of the sample after surface coating shown in the lower part of FIG. 9, the ratio of the sample having an average particle diameter of 20 to 30 [nm] is 1 [%], and the average particle diameter of 30 to 40 [nm] ] Is also 5 [%], the ratio of samples having an average particle diameter of 40 to 50 [nm] is 13 [%], and the ratio of samples having an average particle diameter of 50 to 60 [nm] is 33 [%]. %], The ratio of samples having an average particle diameter of 60 to 70 [nm] is 25 [%], the ratio of samples having an average particle diameter of 70 to 80 [nm] is 16 [%], and the average particle diameter is The ratio of the sample of 80 to 90 [nm] was also 5 [%].
　図９の上図に示した表面コーティング前における試料の平均粒子径の割合と、図９の下図に示す表面コーティング後における試料の平均粒子径の割合とを比較した。図９の上図に示した表面コーティング前の試料に比べて、図９の下図に示す表面コーティング後における試料の平均粒子径が右側にシフトしていることがわかった。すなわち、表面コーティング前における試料よりも、表面コーティング後の試料の平均粒子径が大きくなったことがわかった。 The ratio of the average particle diameter of the sample before the surface coating shown in the upper part of FIG. 9 was compared with the ratio of the average particle diameter of the sample after the surface coating shown in the lower part of FIG. It was found that the average particle diameter of the sample after the surface coating shown in the lower diagram of FIG. 9 is shifted to the right as compared with the sample before the surface coating shown in the upper diagram of FIG. That is, it was found that the average particle size of the sample after the surface coating was larger than that of the sample before the surface coating.
　ここで、図１０を参照して、Ｃ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料の粒子間隙付近のＴＥＭ観察例について説明する。図１０に示すＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料の粒子間隙付近のＴＥＭ観察例によれば、Ｓｉ結晶相（Ｓｉナノ粒子）の表面が５～７ｎｍ程度のアモルファス層で均一に覆われていると共にＳｉナノ粒子４の粒子間隙にも、アモルファスが生成していることがわかった。本発明に係る表面コーティング方法は、Ｓｉナノ粒子４の表面をカーボン系物質２でコーティングするのみならず、通常困難なナノ粒子間隙にもカーボン系物質２を生成できることを示している。このようにＳｉナノ粒子４の粒子間にもカーボン系物質２を形成できるようになった。 Here, with reference to FIG. 10, an example of TEM observation in the vicinity of the particle gap of the C-Si (100) 9 [h] 300 [W] sample will be described. According to the TEM observation example in the vicinity of the particle gap of the C—Si (100) 9 [h] 300 [W] sample shown in FIG. 10, the surface of the Si crystal phase (Si nanoparticles) is an amorphous layer of about 5 to 7 nm. It was found that amorphous was formed in the particle gaps of the Si nanoparticles 4 while being uniformly covered. The surface coating method according to the present invention not only coats the surface of the Si nanoparticles 4 with the carbon-based material 2, but also shows that the carbon-based material 2 can be generated in the normally difficult nanoparticle gaps. As described above, the carbon-based material 2 can be formed also between the Si nanoparticles 4.
　続いて、図１１は、Ｃ－Ｓｉ（１００）９［ｈ］３００［Ｗ］－Ｈ試料のＴＥＭ写真である。図１１の右図に示すＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］－Ｈ試料のＴＥＭ観察例によれば、熱処理後もカーボン系物質２を確認できた。 Subsequently, FIG. 11 is a TEM photograph of the C-Si (100) 9 [h] 300 [W] -H sample. According to the TEM observation example of the C—Si (100) 9 [h] 300 [W] —H sample shown in the right diagram of FIG. 11, the carbon-based material 2 could be confirmed even after the heat treatment.
　図１１の左上図は、Ｓｉ結晶相とカーボン系物質２との境界付近の拡大図である。図中、黒色の３０－５０［ｎｍ］程度のＳｉナノ粒子の回りを薄いグレー色で取り囲んでいる部分がカーボン系物質２である。図１１の左下図は、Ｓｉナノ粒子４及びその周囲の拡大図である。図中、厚み３０－５０［ｎｍ］程度のＳｉナノ粒子４が観測され、格子像が確認されるＳｉナノ粒子４の周囲のアモルファス部分がカーボン系物質２である。熱処理によって、Ｓｉナノ粒子４の炭化を更に進めることができ、導電性を高めることができる。このように、熱処理後の試料においても、Ｓｉナノ粒子４の表面がカーボン系物質２で覆われているが、図１１の右図に示すように熱処理前と比較して幾分不均一になっている。カーボン系物質２の熱処理により更にカーボン化が進行し、熱的な凝集が生じて不均一化しているものと考えられる。 11 is an enlarged view near the boundary between the Si crystal phase and the carbon-based material 2. In the figure, the carbon-based material 2 is a portion surrounding the black Si nanoparticles of about 30-50 [nm] with a light gray color. The lower left diagram in FIG. 11 is an enlarged view of the Si nanoparticles 4 and the surroundings. In the figure, Si nanoparticles 4 having a thickness of about 30-50 [nm] are observed, and the amorphous part around the Si nanoparticles 4 where the lattice image is confirmed is the carbon-based material 2. By the heat treatment, the carbonization of the Si nanoparticles 4 can be further advanced, and the conductivity can be increased. As described above, even in the sample after the heat treatment, the surface of the Si nanoparticles 4 is covered with the carbon-based material 2. However, as shown in the right diagram of FIG. ing. It is considered that carbonization further proceeds due to the heat treatment of the carbon-based material 2, and thermal agglomeration occurs to make it nonuniform.
　続いて、図１２を参照して、Ｃ－Ｓｉ（１００）９［ｈ］２００［Ｗ］及び、Ｃ－Ｓｉ（１００）９［ｈ］２００［Ｗ］－Ｈ各々試料のＴＥＭ観察について説明する。図１２の左図に示すＣ－Ｓｉ（１００）９［ｈ］２００［Ｗ］の試料のＴＥＭ像によれば、熱処理前、超音波出力＝２００［Ｗ］のコーティング処理のみの試料においても、Ｓｉ結晶相（Ｓｉナノ粒子）の表面が厚み５ｎｍ程度のアモルファス層で覆われていることがわかった。カーボン系物質２は厚み５～１０ｎｍ程度を有し、Ｓｉ結晶相の表面をコーティングしていることがわかった。 Next, referring to FIG. 12, TEM observation of each sample of C—Si (100) 9 [h] 200 [W] and C—Si (100) 9 [h] 200 [W] —H will be described. . According to the TEM image of the sample of C—Si (100) 9 [h] 200 [W] shown in the left diagram of FIG. 12, even in the sample of only the coating treatment with ultrasonic output = 200 [W] before the heat treatment, It was found that the surface of the Si crystal phase (Si nanoparticles) was covered with an amorphous layer having a thickness of about 5 nm. It was found that the carbon-based material 2 had a thickness of about 5 to 10 nm and coated the surface of the Si crystal phase.
　図１２の右図に示すＣ－Ｓｉ（１００）９［ｈ］２００［Ｗ］－Ｈ試料のＴＥＭ像によれば、超音波出力＝２００［Ｗ］＋６００［℃］熱処理後も、大きな粒子径を有するＳｉナノ粒子４が観察され、カーボン系物質２も確認できた。図中、丸い部分がＳｉナノ粒子４であり、その周囲のアモルファス部分がカーボン系物質２である。 According to the TEM image of the C—Si (100) 9 [h] 200 [W] −H sample shown in the right diagram of FIG. 12, the ultrasonic power = 200 [W] +600 [° C.] even after heat treatment Si nano-particles 4 having the above were observed, and the carbon-based material 2 was also confirmed. In the figure, the round part is the Si nanoparticle 4, and the surrounding amorphous part is the carbon-based material 2.
　このように、図１２の左図に示した超音波出力が２００［Ｗ］条件で得た試料のＴＥＭ像においても、超音波出力＝３００［Ｗ］の場合と同様にして表面が５～７ｎｍ程度のアモルファスで均一に覆われていると共に、粒子間隙にもアモルファスが生成していた。また、図１２の右図に示した６００［℃］の熱処理後の試料においては、超音波出力＝３００［Ｗ］の場合と同様に多少不均一であるが、表面がカーボン系物質２でコーティングされている様子が確認できた。 Thus, even in the TEM image of the sample obtained under the condition where the ultrasonic output is 200 [W] shown in the left diagram of FIG. 12, the surface has a surface of 5 to 7 nm as in the case of the ultrasonic output = 300 [W]. In addition to being uniformly covered with an amorphous material, amorphous particles were also generated in the particle gaps. In addition, the sample after heat treatment at 600 [° C.] shown in the right diagram of FIG. 12 is somewhat non-uniform as in the case of ultrasonic output = 300 [W], but the surface is coated with the carbon-based material 2. I was able to confirm that it was being done.
　ここで、図１３を参照して、Ｃ－Ｓｉ（１００）３［ｈ］３００［Ｗ］試料のＴＥＭ観察について説明する。図１３に示すＣ－Ｓｉ（１００）３［ｈ］３００［Ｗ］試料のＴＥＭ観察例によれば、超音波照射時間＝３時間と短いことから、Ｓｉ結晶相（Ｓｉナノ粒子）の表面に厚み２ｎｍ程度のアモルファスが部分的に覆われていることがわかった。カーボン系物質２は厚み１～２ｎｍ程度を有し、Ｓｉ結晶相の表面を部分的にコーティングしていることがわかった Here, referring to FIG. 13, TEM observation of a C-Si (100) 3 [h] 300 [W] sample will be described. According to the TEM observation example of the C—Si (100) 3 [h] 300 [W] sample shown in FIG. 13, since the ultrasonic irradiation time is as short as 3 hours, the surface of the Si crystal phase (Si nanoparticles) It was found that an amorphous film having a thickness of about 2 nm was partially covered. It was found that the carbon-based material 2 has a thickness of about 1 to 2 nm and partially coats the surface of the Si crystal phase.
　斜め格子部分のＳｉ結晶相において、アモルファス部分がカーボン系物質２である。熱処理時間が３時間と短いため、カーボン系物質２の修飾量が有るものの完全に付着した部分が少なかった。このように超音波照射時間が短い場合は、Ｓｉ結晶相の表面を部分的にしかコーティングできておらず、また、厚みも薄かった。斜め格子部分のＳｉ結晶相の表面のもやもや以外は、カーボン系物質２がコーティングされていないＳｉＯ2層と考えられる。 In the Si crystal phase of the oblique lattice portion, the amorphous portion is the carbon-based material 2. Since the heat treatment time was as short as 3 hours, the amount of the carbon-based material 2 modified was small, but there were few completely adhered portions. As described above, when the ultrasonic wave irradiation time was short, the surface of the Si crystal phase was only partially coated, and the thickness was thin. Except for the haze on the surface of the Si crystal phase in the oblique lattice portion, it is considered that the SiO 2 layer is not coated with the carbon-based material 2.
　続いて、図１４を参照して、Ｘ線光電子分光（ＸＰＳ）分析例について説明する。図１４の各図において、縦軸は光電子強度で、横軸は電子の束縛エネルギー［ｅＶ］である。また、図１４の各図において、（１）は実測による分析パターンであり、（２）はピーク波形を分離したものである。 Subsequently, an example of X-ray photoelectron spectroscopy (XPS) analysis will be described with reference to FIG. In each diagram of FIG. 14, the vertical axis represents the photoelectron intensity, and the horizontal axis represents the electron binding energy [eV]. Moreover, in each figure of FIG. 14, (1) is the analysis pattern by measurement, (2) isolate | separates the peak waveform.
　図１４の左上図に示す比較例５としてのＳｉナノ粒子４のピーク波形によれば、Ｓｉ結晶由来のＳｉ２ｐ1/2，Ｓｉ２ｐ3/2の２つのピークが束縛エネルギー９８－１００ｅＶに表れ、ＳｉＯ2層のＳｉ２ｐのピークが１０３ｅＶに見られた。実際の試料中のＳｉＯ2層の量はＳｉ結晶相に比べて少ないが、ＸＰＳ分析では表面近傍の情報を得るため、表面にＳｉＯ2層が形成されていることが反映して、ＳｉＯ2層由来のピークも明確に観測された。 According to the peak waveform of Si nanoparticle 4 as Comparative Example 5 shown in the upper left diagram of FIG. 14, two peaks of Si2p 1/2 and Si2p 3/2 derived from Si crystal appear at a binding energy of 98-100 eV, and SiO 2 A two- layer Si2p peak was observed at 103 eV. While the actual amount of the SiO 2 layer in the sample is small as compared with the Si crystal phase, to obtain information of the vicinity of the surface by XPS analysis, reflecting that the SiO 2 layer is formed on the surface, the SiO 2 layer Origin peaks were also clearly observed.
　図１４の左中図に示す実施例２５としてのＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］の試料によれば、コーティング処理のみのＳｉナノ粒子４においても、２つピークが観測された。左側のピークがＳｉ結晶相で右側が低いピークがＳｉＯ2層である。また、図１４の右上図に示す実施例２５の試料によれば、カーボン系物質２のコーティングによるいくつかのピークによりなるＣ１ｓシグナルが観測された。 According to the sample of C—Si (100) 9 [h] 300 [W] as Example 25 shown in the left middle diagram of FIG. 14, two peaks are observed even in the Si nanoparticle 4 only with the coating treatment. It was. The left peak is the Si crystal phase and the lower right peak is the SiO 2 layer. Further, according to the sample of Example 25 shown in the upper right diagram of FIG. 14, a C1s signal composed of several peaks due to the coating of the carbon-based material 2 was observed.
　束縛エネルギー２８７ｅＶ付近のピークは、Ｃ－Ｃｌ結合、２８９ｅＶ付近のブロードなピークは、Ｃ＝Ｃ結合に由来し、カーボン系物質２中に塩素や、Ｃ＝Ｃなどの成分が含まれることを示している。Ｃ＝Ｃ結合は、芳香族有機溶媒であるｏ－ジクロロベンゼンの構造の一部を成すと考えられる。すなわち、Ｓｉナノ粒子４の表面がカーボン系物質２に覆われていることを示している。これはＸＰＳ分析では、最表面ほど、シグナルが大きく、深さ方向の距離に対して指数関数的に信号が小さくなることによる。 The peak near the binding energy of 287 eV is derived from the C—Cl bond, and the broad peak near 289 eV is derived from the C═C bond, indicating that the carbon-based material 2 contains components such as chlorine and C═C. ing. The C═C bond is considered to form part of the structure of o-dichlorobenzene, which is an aromatic organic solvent. That is, the surface of the Si nanoparticle 4 is covered with the carbon-based material 2. This is because, in XPS analysis, the signal is larger at the outermost surface and becomes exponentially smaller with respect to the distance in the depth direction.
　図１４の左下図に示す実施例２６としてのＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］－Ｈ試料の試料によれば、コーティング処理＋熱処理後のＳｉナノ粒子４においても、２つピークが観測された。左側のピークがＳｉで右側が低いピークがＳｉＯ2層である。また、図１４の右下図においても、実施例２５のＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料と同様にして、Ｓｉナノ粒子４の表面にカーボン系物質２が生成していた。また、Ｃ－Ｃｌ由来のピークが消失していた。このことにより、カーボン系物質２のカーボン化がより進行していることが確認できた。これは図１１に示したＴＥＭ像の観察結果と矛盾していない。 According to the sample of C—Si (100) 9 [h] 300 [W] —H sample as Example 26 shown in the lower left diagram of FIG. A peak was observed. The peak on the left side is Si and the peak on the right side is the SiO 2 layer. Also in the lower right diagram of FIG. 14, the carbon-based material 2 was generated on the surface of the Si nanoparticles 4 in the same manner as the C—Si (100) 9 [h] 300 [W] sample of Example 25. . In addition, the peak derived from C—Cl disappeared. From this, it was confirmed that the carbonization of the carbon-based material 2 was further progressed. This is consistent with the observation result of the TEM image shown in FIG.
　このように第１の実施形態に係る電極材料１０によれば、電極を構成する活物質１として、例えば、Ｓｉナノ粒子４の表面にカーボン系物質２が覆われたものを用いている。このカーボン系物質２は、超音波が周波数＝４０ｋＨｚ及び出力２００～３００［Ｗ］の照射時間３［ｈ］～９［ｈ］の条件でｏ－ＤＣＢ３に照射され、当該ｏ－ＤＣＢ３のラジカル反応により生成されたものである。 Thus, according to the electrode material 10 according to the first embodiment, as the active material 1 constituting the electrode, for example, a material in which the carbon-based material 2 is covered on the surface of the Si nanoparticles 4 is used. This carbon-based material 2 is irradiated to o-DCB3 under the conditions of ultrasonic waves of frequency = 40 kHz and an irradiation time of 3 [h] to 9 [h] at an output of 200 to 300 [W], and the radical reaction of the o-DCB3. Is generated.
　この構成によって、Ｓｉナノ粒子４の結晶の隅々までカーボン系物質２が浸入（被着）して、導電性に優れ、Ｌｉイオン挿入・脱離反応に伴う活物質の膨張・収縮による構造崩壊を抑制した安定なＳｉナノ粒子電極材料を提供できるようになった。 With this configuration, the carbon-based material 2 penetrates (deposits) to every corner of the crystal of the Si nanoparticle 4 and is excellent in electrical conductivity. The structure collapses due to expansion / contraction of the active material accompanying Li ion insertion / desorption reaction. It is now possible to provide a stable Si nanoparticle electrode material that suppresses the above.
　また、電極材料１０の製造方法によれば、強力な超音波照射により有機溶媒中にＳｉナノ粒子４を分散させると同時に有機溶媒分子を重合・カーボン化させることにより、Ｓｉ／カーボンの複合体を合成できた。すなわち、Ｓｉナノ粒子４の表面にナノメートルオーダーの厚みのカーボンを形成できるようになった。カーボン系物質２によるＳｉナノ粒子４の表面修飾に用いられる有機溶媒は、ジクロロベンゼンに限定されることはなく、他の芳香族系化合物でもよい。 Moreover, according to the manufacturing method of the electrode material 10, the Si / carbon composite is formed by dispersing the Si nanoparticles 4 in the organic solvent by strong ultrasonic irradiation and simultaneously polymerizing and carbonizing the organic solvent molecules. I was able to synthesize. That is, carbon having a thickness on the order of nanometers can be formed on the surface of the Si nanoparticles 4. The organic solvent used for the surface modification of the Si nanoparticles 4 with the carbon-based material 2 is not limited to dichlorobenzene, and may be other aromatic compounds.
　しかも、カーボン系物質２による表面修飾方法は、非重合性の有機溶媒（ジクロロベンゼン）にＳｉナノ粒子４を加え、超音波を照射するだけの簡単な方法であって、簡便かつ大量生産にも利用できる方法である。また、超音波出力や、超音波照射時間、活物質１の濃度等に依存して、カーボン生成量を変化させることができる。第１の実施形態では、活物質１がＳｉナノ粒子４である場合について説明したが、これに限られることはなく、活物質１がＳｉを含む化合物から選択されるＳｉＯｘ（０＜ｘ＜２）等であってもよい。尚、Ｓｉナノ粒子４に代えて、Ｌｉ2ＳｉＯ３粒子（粒径１～１０［μｍ］）でも前述のＳｉナノ粒子４における電極材料１０の製造方法と同条件で実験を行い、Ｌｉ2ＳｉＯ３粒子表面にナノメートルオーダーの厚みのカーボンを形成できた。すなわち、強力な超音波照射により有機溶媒中にＬｉ2ＳｉＯ３粒子を分散させると同時に有機溶媒分子を重合・カーボン化させることにより、Ｌｉ2ＳｉＯ３粒子／カーボンの複合体を合成できた。このことから、組成式ＬｉxＳｉＯyで表され、リチウム含有量ｘと酸素量ｙがそれぞれ０≦ｘ、０＜ｙ≦２であるリチウム含有ケイ素酸化物においても本発明を適用可能である。 In addition, the surface modification method using the carbon-based material 2 is a simple method in which Si nanoparticles 4 are added to a non-polymerizable organic solvent (dichlorobenzene) and irradiated with ultrasonic waves. It is an available method. In addition, the amount of carbon produced can be changed depending on the ultrasonic output, the ultrasonic irradiation time, the concentration of the active material 1, and the like. In the first embodiment, the case where the active material 1 is the Si nanoparticles 4 has been described. However, the present invention is not limited to this, and the active material 1 is selected from compounds containing Si. SiOx (0 <x <2 Or the like. It should be noted that, instead of the Si nanoparticles 4, Li2SiO3 particles (particle size 1 to 10 [μm]) were also subjected to experiments under the same conditions as in the method for producing the electrode material 10 in the Si nanoparticles 4 described above. Carbon of the order thickness could be formed. That is, a Li2SiO3 particle / carbon composite could be synthesized by dispersing Li2SiO3 particles in an organic solvent by strong ultrasonic irradiation and simultaneously polymerizing and carbonizing organic solvent molecules. From this, the present invention can also be applied to a lithium-containing silicon oxide represented by the composition formula LixSiOy and having a lithium content x and an oxygen content y of 0 ≦ x and 0 <y ≦ 2, respectively.
　＜第２の実施形態＞
　［負極］
　ここで、図１５を参照して、第２の実施形態としての負極１１の形成方法について説明する。この例では、Ｃ－Ｓｉ（Ｘ）Ｙ［ｈ］Ｚ［Ｗ］試料で負極１１を形成する場合を前提とする。まず、図１５の上図に示す電極材料１０を準備する。電極材料１０は、負極用の電極材料、即ち負極材料であり、全表面あるいはその一部表面がカーボン系物質２により覆われたＳｉナノ粒子４（負極活物質）からなる。電極材料１０は、図１～図１４で説明したＣ－Ｓｉ（Ｘ）Ｙ［ｈ］Ｚ［Ｗ］試料を使用する。負極１１は、電極材料１０を負極集電体上に設けてなる。 <Second Embodiment>
[Negative electrode]
Here, with reference to FIG. 15, the formation method of the negative electrode 11 as 2nd Embodiment is demonstrated. In this example, it is assumed that the negative electrode 11 is formed of a C—Si (X) Y [h] Z [W] sample. First, an electrode material 10 shown in the upper diagram of FIG. 15 is prepared. The electrode material 10 is an electrode material for a negative electrode, that is, a negative electrode material, and is composed of Si nanoparticles 4 (negative electrode active material) whose entire surface or a part of the surface thereof is covered with the carbon-based material 2. As the electrode material 10, the C—Si (X) Y [h] Z [W] sample described in FIGS. 1 to 14 is used. The negative electrode 11 is formed by providing an electrode material 10 on a negative electrode current collector.
　例えば、（Ｃ－Ｓｉ（１００）９［ｈ］３００［Ｗ］）試料で負極１１を形成する場合、Ｃ－（１００）９［ｈ］３００［Ｗ］）試料と、導電助材のアセチレンブラック（ＡＢ）と、ポリフッ化ビニデリン樹脂（ＰＶＤＦ）あるいはポリテトラフロアスチレン（ＰＴＦＥ）等の結着材とを機械的に混合して練り合わせて混合ペーストを形成した。ＡＢや、ＰＴＦＥ、ＰＶＤＦ等のサンプルの混合比は、試料：ＡＢ：（ＰＴＦＥ又はＰＶＤＦ）＝４：４：２（ｗｔ％：ｗｔ％：ｗｔ％）である。 For example, in the case where the negative electrode 11 is formed from a (C—Si (100) 9 [h] 300 [W]) sample, the C− (100) 9 [h] 300 [W]) sample and the conductive auxiliary material acetylene black (AB) and a binder such as polyvinylidene fluoride resin (PVDF) or polytetrafloor styrene (PTFE) were mechanically mixed and kneaded to form a mixed paste. The mixing ratio of samples such as AB, PTFE, and PVDF is sample: AB: (PTFE or PVDF) = 4: 4: 2 (wt%: wt%: wt%).
　そして、図１５の下図に示すＮｉメッシュ７に混合ペーストを塗布あるいは圧着した。更に、電気管状炉において、温度１５０［℃］、乾燥時間２［ｈ］、Ａｒ雰囲気でＮｉメッシュ７上の混合ペーストを乾燥した。その後、コールドトラップにおいて、温度１５０［℃］で、乾燥時間２［ｈ］で、Ｎｉメッシュ７上の混合ペーストを更に真空乾燥した。これにより、Ｎｉメッシュ７上に（Ｃ－Ｓｉ（１００）９［ｈ］３００［Ｗ］）試料が被着した負極１１が完成した。 Then, the mixed paste was applied or pressure-bonded to the Ni mesh 7 shown in the lower part of FIG. Further, the mixed paste on the Ni mesh 7 was dried in an electric tubular furnace at a temperature of 150 [° C.], a drying time of 2 [h], and an Ar atmosphere. Thereafter, in a cold trap, the mixed paste on the Ni mesh 7 was further vacuum-dried at a temperature of 150 [° C.] and a drying time of 2 [h]. Thereby, the negative electrode 11 in which the (C—Si (100) 9 [h] 300 [W]) sample was deposited on the Ni mesh 7 was completed.
　実際のＬｉイオン二次電池に適用する場合は、図１５の下図に示すＮｉメッシュ７に代えて、厚み数十μｍのＣｕ、Ｎｉ、ＳＵＳ等の箔状の集電体に混合ペーストを塗布する。その後、当該試料を乾燥することにより、Ｌｉイオン二次電池の負極１１（負極集電体ｅ－）を得ることができる。 When applied to an actual Li ion secondary battery, instead of the Ni mesh 7 shown in the lower part of FIG. 15, a mixed paste is applied to a foil-like current collector of Cu, Ni, SUS or the like having a thickness of several tens of μm. . Thereafter, the negative electrode 11 (negative electrode current collector e-) of the Li ion secondary battery can be obtained by drying the sample.
　負極１１に用いられる電極材料１０によれば、全表面あるいはその一部表面がカーボン系物質２により覆われた負極活物質を含むので、合金系負極活物質の安定化に寄与するところが大きい。しかも、電極材料１０は、理論充放電容量４２００［ｍＡｈ／ｇ］の大容量のＳｉ負極活物質を有するため、現在の負極材料として利用されている理論容量３７２［ｍＡｈ／ｇ］の黒鉛の１０倍以上の容量を有する負極１１を提供できる。 According to the electrode material 10 used for the negative electrode 11, the entire surface or a part of the surface thereof includes the negative electrode active material covered with the carbon-based material 2, which greatly contributes to the stabilization of the alloy-based negative electrode active material. Moreover, since the electrode material 10 has a large capacity Si negative electrode active material having a theoretical charge / discharge capacity of 4200 [mAh / g], 10 of graphite having a theoretical capacity of 372 [mAh / g] which is currently used as a negative electrode material. The negative electrode 11 having a double or more capacity can be provided.
　続いて、図１６を参照して、負極１１の電気化学測定装置について説明する。図１６に示す三極式セル２０は、図１５に示した負極１１の電気化学測定をするものである。三極式セル２０は、Ｌｉイオン二次電池の充放電原理を成す。 Subsequently, an electrochemical measurement apparatus for the negative electrode 11 will be described with reference to FIG. A tripolar cell 20 shown in FIG. 16 performs electrochemical measurement of the negative electrode 11 shown in FIG. The tripolar cell 20 forms the charge / discharge principle of a Li ion secondary battery.
　負極１１（作用電極（Working electrode））等の電気化学測定には、三極式セル２０の他に充・放電測定装置２１が使用される。三極式セル２０は、クリップ１３、セル容器２２、電極引き出し用の蓋体２３、電解液２４（Electrolyte）、対極２５（Counter　electrode）、参照極２６（Reference electrode）及びルギン管２７を有している。クリップ１３は負極１１の引き出し線を挟持させた。クリップ１３は所定のリード線を介して充・放電測定装置２１に接続した。 In addition to the tripolar cell 20, a charge / discharge measuring device 21 is used for electrochemical measurement of the negative electrode 11 (working electrode). The triode cell 20 includes a clip 13, a cell container 22, a lid 23 for drawing out an electrode, an electrolyte solution 24 (Electrolyte), a counter electrode 25 (Counter electrode), a reference electrode 26 (Reference electrode), and a Lugin tube 27. ing. The clip 13 sandwiched the lead wire of the negative electrode 11. The clip 13 was connected to the charge / discharge measuring device 21 via a predetermined lead wire.
　対極２５及び参照極２６は、所定のリード線に接続し、電極引き出し用の蓋体２３を介して充・放電測定装置２１に接続した。対極２５及び参照極２６には、金属ＬｉをＮｉメッシュに圧着したもの（Ｌｉon　Ｎｉ　mesh）を用いた。負極１１、対極２５及び参照極２６は電解液２４内に浸した。電解液２４は、１Ｍ　ＬｉＰＦ6／［ＥＣ：ＤＭＣ（１：１）］を用いた。エチレンカーボネート（ＥＣ）とジメチルカーボネート（ＤＭＣ）の重量比は５０：５０である。上記セル作成はグローブボックス中でＡｒ雰囲気で行った。 The counter electrode 25 and the reference electrode 26 were connected to a predetermined lead wire and connected to the charge / discharge measuring device 21 via the electrode lead-out lid 23. As the counter electrode 25 and the reference electrode 26, metal Li bonded to Ni mesh (Lion Ni mesh) was used. The negative electrode 11, the counter electrode 25 and the reference electrode 26 were immersed in the electrolytic solution 24. As the electrolytic solution 24, 1M LiPF 6 / [EC: DMC (1: 1)] was used. The weight ratio of ethylene carbonate (EC) to dimethyl carbonate (DMC) is 50:50. The cell preparation was performed in an Ar atmosphere in a glove box.
　この例では、電解液抵抗をできるだけ小さくするために、参照極２６を可能な限りルギン管２７を介して負極１１に近づけた。アルゴン雰囲気で三極式セル２０にて負極１１の電気化学測定を行った。負極１１を構成するＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料の測定電圧範囲は、３～０．０１［Ｖ］である。その他のサンプル極の電圧測定電圧範囲は２～０．０１［Ｖ］である。 In this example, in order to make the electrolyte resistance as small as possible, the reference electrode 26 was brought as close as possible to the negative electrode 11 through the Lugin tube 27. Electrochemical measurement of the negative electrode 11 was performed in the triode cell 20 in an argon atmosphere. The measurement voltage range of the C—Si (100) 9 [h] 300 [W] sample constituting the negative electrode 11 is 3 to 0.01 [V]. The voltage measurement voltage range of the other sample electrodes is 2 to 0.01 [V].
　充・放電測定装置２１には、北斗電工製のエレクトロケミカルアナライザー（ＨＪ－ＳＭ８）を用い、定電流電気量測定（ＣＣ）モードで測定を行った。充・放電測定装置２１は、ポテンショスタットやガルバノスタット機能を有しており、電位一定や、電流一定での測定ができるものである。 For the charge / discharge measuring device 21, an electrochemical analyzer (HJ-SM8) manufactured by Hokuto Denko was used, and the measurement was performed in a constant current electricity measurement (CC) mode. The charge / discharge measuring device 21 has a potentiostat or galvanostat function, and can measure at a constant potential or a constant current.
　Ｓｉ重量基準の電流密度は２１０［ｍＡ／ｇ］および４２０［ｍＡ／ｇ］であり、電位域は０．０１［Ｖ］～３．０［Ｖ］　ｖｓ　Ｌｉ／Ｌｉ+であり、室温の条件の下で、定電流充放電測定を行った。定電流充放電測定によれば、充・放電測定装置２１のガルバノスタットで電流を一定にし、充・放電測定装置２１から三極式セル２０へ一定電流を流し、三極式セル２０の電位とクーロン量の変化を充・放電測定装置２１でモニターする方法を採った。 The current density based on the weight of Si is 210 [mA / g] and 420 [mA / g], the potential range is 0.01 [V] to 3.0 [V] vs Li / Li +, and room temperature conditions The constant current charge / discharge measurement was performed. According to the constant current charge / discharge measurement, the current is made constant by the galvanostat of the charge / discharge measuring device 21, and a constant current is passed from the charge / discharge measuring device 21 to the tripolar cell 20. A method of monitoring the change in coulomb amount with the charge / discharge measuring device 21 was adopted.
　一般に、電池関連の電気化学測定では、ＣＣモードや、ＣＣ－ＣＶモード等の２種類が採用された。ＣＣモードでは、三極式セル２０へ一定電流を流し、その電気量を測定した。ＣＣ－ＣＶモードでは、ＣＣモードで、ある電位まで電流を流した後に、一定電位で保持して充放電しきれていない電気量を流したのちにＣＣモードで測定を続ける。本測定では、Ｓｉ系電極は、ＣＣモードで電気化学測定が行った。 Generally, two types of battery-related electrochemical measurements such as CC mode and CC-CV mode were adopted. In the CC mode, a constant current was passed through the triode cell 20 and the amount of electricity was measured. In the CC-CV mode, in the CC mode, after a current is passed to a certain potential, the measurement is continued in the CC mode after a quantity of electricity that is held at a constant potential and not fully charged / discharged is passed. In this measurement, the Si-based electrode was subjected to electrochemical measurement in the CC mode.
　本発明者らは、定電流充放電測定において、カーボン系物質２の表面コーティングにより、Ｓｉ負極活物質のみの場合と比べて、充放電容量、サイクル安定性ともに向上することを確認した。さらに、熱処理を行った試料は、充放電容量がさらに増加することを確認した。 In the constant current charge / discharge measurement, the present inventors confirmed that the surface coating of the carbon-based material 2 improves both the charge / discharge capacity and the cycle stability as compared with the case of using only the Si negative electrode active material. Further, it was confirmed that the charge / discharge capacity of the sample subjected to the heat treatment was further increased.
　ここで、図１７を参照して、Ｓｉ系試料の充放電特性について説明する。図１７の各図は電流密度条件４２０［ｍＡ／ｇ］時の各試料の充放電曲線（カーブ）を示している。この例では、未修飾のＳｉナノ粒子系試料、Ｃ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料及びＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］－Ｈ試料の３つの電極材料を用いた。各電極材料を有する負極１１について、これらの充放電動作を１回～４回を行って、充放電特性を比較（考察）した。 Here, the charge / discharge characteristics of the Si-based sample will be described with reference to FIG. Each figure in FIG. 17 shows a charge / discharge curve (curve) of each sample under a current density condition of 420 [mA / g]. In this example, three electrodes of an unmodified Si nanoparticle-based sample, a C—Si (100) 9 [h] 300 [W] sample, and a C—Si (100) 9 [h] 300 [W] —H sample Material was used. For the negative electrode 11 having each electrode material, these charge / discharge operations were performed once to four times, and the charge / discharge characteristics were compared (considered).
　負極１１（作用電極）については、図１６で説明したように、Ｃ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料４０ｗｔ％＋導電助材４０ｗｔ％＋結着材２０ｗｔ％である。対極２５及び参照極２６は、金属ＬｉをＮｉメッシュに圧着したものである。その測定電圧範囲は、３～０．０１［Ｖ］である。電解液２４は、１．０Ｍ　ＬｉＰＦ6（ＥＣ：ＤＭＣ＝１：１）である。充電電流密度は、４２０［ｍＡ／ｇ］である。ＣＣモードで電気化学測定を行った。 For the negative electrode 11 (working electrode), as described with reference to FIG. 16, C—Si (100) 9 [h] 300 [W] sample 40 wt% + conducting aid 40 wt% + binder 20 wt%. The counter electrode 25 and the reference electrode 26 are metal Li bonded to a Ni mesh. The measurement voltage range is 3 to 0.01 [V]. The electrolyte solution 24 is 1.0M LiPF 6 (EC: DMC = 1: 1). The charging current density is 420 [mA / g]. Electrochemical measurements were performed in CC mode.
　図１７の各図において、縦軸は三極式セル２０の電位（Potential/［Ｖ vs Ｌｉ／Ｌｉ+］である。図１７の左図に示す横軸は、Ｓｉナノ粒子４のＳｉ重量当たりの放電容量（Capacity）[ｍＡｈ／ｇ］である。図１７の中図及び右図に示す横軸は、Ｓｉ＋修飾済みのカーボン系物質２の複合体重量を当たりの放電容量［ｍＡｈ／ｇ］である。 17, the vertical axis represents the potential of the triode cell 20 (Potential / [V vs Li / Li + ]. The horizontal axis shown in the left diagram of FIG. 17 represents the Si weight of the Si nanoparticles 4. The horizontal axis shown in the middle and right diagrams of Fig. 17 is the discharge capacity [mAh / g] per unit weight of the Si + -modified carbon-based material 2. It is.
　図１７の左図は、Ｓｉナノ粒子系試料の充放電特性である。図１７の左図において、図中の数字（１），（２），（３），（４）は、充放電サイクルの順番を示している。（１）は、Ｓｉナノ粒子系試料の初回の充放電曲線である。（２）は、Ｓｉナノ粒子系試料の２回目の充放電曲線である。（３）は、Ｓｉナノ粒子系試料の３回目の充放電曲線である。（４）は、Ｓｉナノ粒子系試料の４回目の充放電曲線である。 The left diagram in FIG. 17 shows the charge / discharge characteristics of the Si nanoparticle sample. In the left figure of FIG. 17, numerals (1), (2), (3), (4) in the figure indicate the order of the charge / discharge cycles. (1) is an initial charge / discharge curve of the Si nanoparticle sample. (2) is a second charge / discharge curve of the Si nanoparticle sample. (3) is the third charge / discharge curve of the Si nanoparticle sample. (4) is a fourth charge / discharge curve of the Si nanoparticle sample.
　図１７の中図に示すコーティング処理後（熱処理前）のＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料によれば、充電曲線が図１７の左図に示したＳｉナノ粒子系試料の充放電曲線に比べて左側にシフトしている。図１７の中図において、（１）はＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料の初回の充放電曲線である。（２）はＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料の２回目の充放電曲線である。（３）はＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料の３回目の充放電曲線である。（４）はＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料の４回目の充放電曲線である。 According to the C—Si (100) 9 [h] 300 [W] sample after the coating treatment (before the heat treatment) shown in the middle diagram of FIG. 17, the charge curve of the Si nanoparticle sample shown in the left diagram of FIG. It is shifted to the left as compared with the charge / discharge curve. In the middle diagram of FIG. 17, (1) is the initial charge / discharge curve of the C—Si (100) 9 [h] 300 [W] sample. (2) is the second charge / discharge curve of the C—Si (100) 9 [h] 300 [W] sample. (3) is the third charge / discharge curve of the C—Si (100) 9 [h] 300 [W] sample. (4) is the fourth charge / discharge curve of the C—Si (100) 9 [h] 300 [W] sample.
　図１７の右図に示すコーティング＋熱処理後のＣ－Ｓｉ（１００）９［ｈ］３００Ｗ－Ｈ試料によれば、充電曲線が図１７の左図に示したＳｉナノ粒子系試料の充放電曲線に比べて右側にシフトしている。図１７の右図において、（１）はＣ－Ｓｉ（１００）９［ｈ］３００Ｗ－Ｈ試料の初回の充放電曲線である。（２）はＣ－Ｓｉ（１００）９［ｈ］３００Ｗ－Ｈ試料の２回目の充放電曲線である。（３）はＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］－Ｈ試料の３回目の充放電曲線である。（４）はＣ－Ｓｉ（１００）９［ｈ］３００Ｗ－Ｈ試料の４回目の充放電曲線である。 According to the C + Si (100) 9 [h] 300W—H sample after coating + heat treatment shown in the right diagram of FIG. 17, the charge curve is the charge / discharge curve of the Si nanoparticle-based sample shown in the left diagram of FIG. It is shifted to the right compared to In the right diagram of FIG. 17, (1) is the initial charge / discharge curve of the C—Si (100) 9 [h] 300W—H sample. (2) is the second charge / discharge curve of the C—Si (100) 9 [h] 300W—H sample. (3) is the third charge / discharge curve of the C—Si (100) 9 [h] 300 [W] —H sample. (4) is the fourth charge / discharge curve of the C—Si (100) 9 [h] 300W—H sample.
　図１７の各図に示す充放電曲線において、電位が小さくなるにつれて、容量が増えている右下がりの曲線が充電時の曲線（充電曲線）である。負極１１の充電曲線は、Ｓｉナノ粒子４がＬｉを吸蔵する合金反応（Ｓｉ＋ｘＬｉ→ＬｉｘＳｉ）によるものである。初回の充電曲線には、電解液分解により生じる界面皮膜（ＳＥＩ）形成の容量も含まれる。 In the charging / discharging curves shown in each diagram of FIG. 17, the curve at the lower right where the capacity increases as the potential decreases is the curve during charging (charging curve). The charging curve of the negative electrode 11 is due to an alloy reaction (Si + xLi → LixSi) in which the Si nanoparticles 4 occlude Li. The initial charge curve also includes the capacity of the interfacial film (SEI) formation caused by electrolyte decomposition.
　Ｓｉナノ粒子４とＬｉとの合金反応（Ｓｉ＋ｘＬｉ→ＬｉｘＳｉ）は、Ｌｉ基準の電位では、通常０．３［Ｖ］以下で生じる。図１７の各図に各々示す充電曲線における０．３［Ｖ］以下の横ばいの特性（容量増加）は、この反応が起きていることを示している。 The alloy reaction (Si + xLi → LixSi) between the Si nanoparticle 4 and Li usually occurs at 0.3 [V] or less at a potential based on Li. The leveling characteristics (capacity increase) of 0.3 [V] or less in the charging curves shown in each diagram of FIG. 17 indicate that this reaction occurs.
　また、図１７の各図に示す充放電曲線において、電位が大きくなるにつれて容量が大きくなる右上がりの特性が放電時の曲線（放電曲線）である。負極１１の放電曲線は、Ｌｉを離脱する脱合金反応（ＬｉｘＳｉ→Ｓｉ＋ｘＬｉ）によるものである。基準となる負極１１の重量がＳｉナノ粒子４とＣ－Ｓｉ（Ｘ）Ｙ［ｈ］Ｚ［Ｗ］試料等の複合体では充放電特性が異なるため、図１８において、Ｓｉ重量基準で放電容量の数値を比較し両者を考察した。 Further, in the charge / discharge curves shown in each diagram of FIG. 17, the characteristic that increases in capacity as the electric potential increases is a curve at the time of discharge (discharge curve). The discharge curve of the negative electrode 11 is due to a dealloying reaction (LixSi → Si + xLi) that releases Li. Since the weight of the negative electrode 11 serving as a reference is different in the charge / discharge characteristics of a composite such as a Si nanoparticle 4 and a C—Si (X) Y [h] Z [W] sample, in FIG. Both figures were compared and considered.
　図１８を参照して、Ｓｉ系試料の放電特性について説明する。この例では、充電電流密度４２０［ｍＡ／ｇ］時の２つのＳｉ系試料の放電サイクル特性を得て、両者を比較した。すなわち、４２０［ｍＡ／ｇ］の電流密度条件で測定した各試料の充放電曲線（カーブ）から各試料の放電サイクル特性を求めた。ここで求めたＳｉナノ粒子の放電容量（Ｓｉ重量当たりの容量）の充放電サイクルに伴う変化と、Ｓｉ＋修飾済みのカーボン系物質２の複合体重量当たりの放電容量とを比較した。試料はＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］である。 The discharge characteristics of the Si-based sample will be described with reference to FIG. In this example, the discharge cycle characteristics of two Si-based samples at a charging current density of 420 [mA / g] were obtained and compared. That is, the discharge cycle characteristic of each sample was determined from the charge / discharge curve (curve) of each sample measured under a current density condition of 420 [mA / g]. The change with the charge / discharge cycle of the discharge capacity (capacity per Si weight) of the Si nanoparticles obtained here was compared with the discharge capacity per weight of the complex of the Si + -modified carbon-based material 2. The sample is C—Si (100) 9 [h] 300 [W].
　図１８の左図は、充放電サイクル１～１０回の測定におけるＳｉ系試料の複合体（Ｓｉ／Ｃ）重量当たりの放電容量（ＳＯＣ（充電率）：０～１００％）を示す放電特性図である。Ｓｉ系試料の放電サイクル特性において、縦軸は放電容量（Capacity）[ｍＡｈ（ｇ－Ｓｉ）-1］であり、横軸は回数（Cycle Number）である。ただし、比較例１０はＳｉのみ（コーティングなし）の試料なので、Ｓｉ重量当りの放電容量で示している。 The left figure of FIG. 18 is a discharge characteristic diagram showing the discharge capacity (SOC (charge rate): 0 to 100%) per weight of the composite (Si / C) of the Si-based sample in measurement of 1 to 10 charge / discharge cycles. It is. In the discharge cycle characteristics of the Si-based sample, the vertical axis represents the discharge capacity (Capacity) [mAh (g-Si) −1 ], and the horizontal axis represents the number of cycles (Cycle Number). However, since Comparative Example 10 is a sample containing only Si (no coating), the discharge capacity per unit weight of Si is shown.
　図１８の左図において、四角印で示された比較例１０は、Ｓｉナノ粒子４のままの放電サイクル特性である。比較例１０によれば、中段から下段に移行する特性は１０回目の放電サイクルで容量が１００ｍＡｈ／ｇ以下であった。また、三角印で示された実施例３５は、コーティング処理後の特性であり、初期回数で容量が低いが、４回目以降でＳｉナノ粒子４の特性と反転した。１０回目で放電容量２００［ｍＡｈ／ｇ］以上を維持していた。更に、楕円印で示された実施例３６は、コーティング処理＋熱処理後の特性であり、１０回の放電容量３００［ｍＡｈ／ｇ］以上を維持していた。 In the left diagram of FIG. 18, Comparative Example 10 indicated by a square mark is the discharge cycle characteristics of the Si nanoparticles 4 as they are. According to Comparative Example 10, the characteristic of shifting from the middle stage to the lower stage was a capacity of 100 mAh / g or less in the tenth discharge cycle. In addition, Example 35 indicated by a triangle mark shows the characteristics after the coating treatment, and the capacity is low at the initial number of times, but is reversed from the characteristics of the Si nanoparticles 4 after the fourth time. The discharge capacity was maintained at 200 [mAh / g] or more at the 10th time. Further, Example 36 indicated by an ellipse is a characteristic after coating treatment + heat treatment, and maintained a discharge capacity of 300 [mAh / g] or more for 10 times.
　図１８の右図は、Ｓｉ同士の放電特性を抽出して比較するためのＳｉ重量当たりの放電容量（ＳＯＣ：０～１００％）を示す放電特性図である。Ｓｉ重量当たりの放電サイクル特性において、縦軸は放電容量（Capacity）[ｍＡｈ（ｇ－Ｓｉ）-1］であり、横軸は回数（Cycle Number）である。図１８の右図において、四角印で示された比較例１０は、Ｓｉナノ粒子４の場合の放電サイクル特性である。この放電サイクル特性によれば、初回で１２００［ｍＡｈ／ｇ］と放電容量が高いが、１０回目で１００［ｍＡｈ／ｇ］以下と急激に放電容量が低くなった。 The right figure of FIG. 18 is a discharge characteristic diagram showing the discharge capacity (SOC: 0 to 100%) per Si weight for extracting and comparing discharge characteristics between Si. In the discharge cycle characteristics per Si weight, the vertical axis represents the discharge capacity (Capacity) [mAh (g-Si) −1 ], and the horizontal axis represents the number of cycles (Cycle Number). In the right diagram of FIG. 18, Comparative Example 10 indicated by a square mark is a discharge cycle characteristic in the case of Si nanoparticles 4. According to this discharge cycle characteristic, the discharge capacity was high at 1200 [mAh / g] for the first time, but the discharge capacity rapidly decreased to 100 [mAh / g] or less at the 10th time.
　また、三角印で示された実施例３７は、コーティング処理後の放電サイクル特性である。初回で１２５０［ｍＡｈ／ｇ］と放電容量が高く、１０回目で放電容量４００［ｍＡｈ／ｇ］を維持していた。更に、実線に丸印の実施例３８は、コーティング処理＋熱処理後の放電サイクル特性である。この放電サイクル特性によれば、１０回目の放電容量で４００［ｍＡｈ／ｇ］を維持していた。 Further, Example 37 indicated by a triangle mark is a discharge cycle characteristic after the coating treatment. The discharge capacity was high at 1250 [mAh / g] at the first time, and the discharge capacity was 400 [mAh / g] at the 10th time. Further, Example 38 indicated by a circle on the solid line shows the discharge cycle characteristics after coating and heat treatment. According to this discharge cycle characteristic, 400 [mAh / g] was maintained at the discharge capacity of the 10th time.
　図１８の左図の比較例１０に示したＳｉナノ粒子４の放電サイクル特性によれば、サイクル回数の増加と共に急激に放電容量が減少し、１０サイクル後はほとんど容量を有していなかった。Ｓｉナノ粒子４はＬｉと合金化すると、例えば、Ｌｉ4.4Ｓｉでは、体積が４倍に膨張する。また、Ｓｉナノ粒子４は脱合金化すると、Ｌｉ4.4Ｓｉに比べて体積が１／４に収縮する。この大きな体積変化により微粉化が生じ、集電体からの欠落や、接触不良による電極内電子伝導性が低下する。 According to the discharge cycle characteristics of the Si nanoparticles 4 shown in Comparative Example 10 in the left diagram of FIG. 18, the discharge capacity rapidly decreased with an increase in the number of cycles, and almost no capacity was obtained after 10 cycles. When the Si nanoparticles 4 are alloyed with Li, for example, Li 4.4 Si expands the volume four times. Further, when the Si nanoparticles 4 are dealloyed, the volume shrinks to 1/4 compared to Li 4.4 Si. Due to this large volume change, pulverization occurs, resulting in a loss from the current collector and in-electrode electron conductivity due to poor contact.
　一方、図１８の左図の実施例３５に示したＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料は、サイクル初期の放電容量は小さいものの、サイクル経過に伴う容量減少が少なかった。５サイクル以降では、むしろ、Ｓｉナノ粒子４の放電サイクル特性に比べて、より放電容量が大きくなった。カーボン系物質２による表面コーティングにより、Ｓｉナノ粒子４の合金・脱合金化反応に伴う構造破壊が抑制され、安定な充放電ができるようになったものと考えられる。 On the other hand, the C—Si (100) 9 [h] 300 [W] sample shown in Example 35 on the left side of FIG. 18 had a small discharge capacity at the beginning of the cycle, but the capacity decrease with the passage of the cycle was small. After 5 cycles, rather, the discharge capacity was larger than the discharge cycle characteristics of the Si nanoparticles 4. It is considered that the surface coating with the carbon-based material 2 suppresses the structural breakdown accompanying the alloy / dealloying reaction of the Si nanoparticles 4 and enables stable charge / discharge.
　更に、図１８の左図の実施例３６に示したＣ－Ｓｉ（１００）９ｈ３００Ｗ－Ｈによれば、熱処理により初期容量が増加した（導電性が向上した）。すなわち、カーボン系物質２の熱処理によるカーボン化の進行により、導電性が向上したため、放電容量の値がＳｉナノ粒子４や、未焼成の放電サイクル特性等よりも向上した。しかし、ＴＥＭ観察で見られるように、コーティングが必ずしも均一でないため、サイクル劣化が大きいものとなった。 Furthermore, according to C-Si (100) 9h300W-H shown in Example 36 in the left diagram of FIG. 18, the initial capacity was increased by heat treatment (conductivity was improved). That is, since the conductivity is improved by the progress of carbonization by the heat treatment of the carbon-based material 2, the value of the discharge capacity is improved more than the Si nanoparticles 4 and the unfired discharge cycle characteristics. However, as can be seen by TEM observation, the coating is not necessarily uniform, resulting in large cycle degradation.
　図１８の右図は、同じ重量基準で放電サイクル特性を比較するために、比較例１０でＳｉ重量当たりのサイクル特性を示した。実施例３７のＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料中のＳｉは、未修飾のＳｉナノ粒子４と比べて初期は、同程度の放電容量を示すものの、サイクル経過に伴う容量低下が小さかった。すなわち、カーボン系物質２のコーティングにより、サイクル安定性が向上した。これに対して、実施例３８のＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］－Ｈ試料は、熱処理を行うことにより、導電性が向上した。これにより、大幅に初期容量が増加していることがわかった。 The right diagram in FIG. 18 shows the cycle characteristics per Si weight in Comparative Example 10 in order to compare the discharge cycle characteristics on the same weight basis. The Si in the C—Si (100) 9 [h] 300 [W] sample of Example 37 initially shows the same discharge capacity as that of the unmodified Si nanoparticles 4, but the cycle progresses. The capacity drop was small. That is, the cycle stability was improved by the coating of the carbon-based material 2. On the other hand, the conductivity of the C—Si (100) 9 [h] 300 [W] —H sample of Example 38 was improved by heat treatment. As a result, it was found that the initial capacity was greatly increased.
　続いて、図１９を参照して、Ｓｉ系試料の充放電特性について説明する。本発明者らは、充電電流密度が高くなると、一般に電極内の分極が大きくなるため、充放電容量が小さくなり、また、Ｓｉ系では、充電電流密度が高いほど合金、脱合金化反応を高速で行わせるため、体積変化速度が大きく、構造崩壊が生じ易くなると考えた。そこで、より低い電流密度での測定を行った。 Subsequently, the charge / discharge characteristics of the Si-based sample will be described with reference to FIG. As the charging current density increases, the present inventors generally increase the polarization in the electrode, thereby reducing the charge / discharge capacity. In the Si system, the higher the charging current density, the faster the alloy and dealloying reaction. Therefore, it was considered that the volume change rate is large and the structure collapse is likely to occur. Therefore, measurement was performed at a lower current density.
　この例では、充電電流密度２１０［ｍＡ／ｇ］時の２つのＳｉ系試料の放電サイクル特性を得て、Ｓｉ系試料の放電サイクル特性を比較した。すなわち、２１０［ｍＡ／ｇ］の電流密度条件で測定した各試料の充放電曲線（カーブ）から、放電サイクル特性を求めた。ここで求めたＳｉナノ粒子の放電容量（Ｓｉ重量当たりの容量）の充放電サイクルに伴う変化と、カーボン系物質２で修飾されたＳｉナノ粒子のＳｉ重量当たりの放電容量の充放電サイクルとを比較した。試料には、４２０［ｍＡ／ｇ］条件の測定でサイクル安定性が優れていた、図１７の中図に示したＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］を有する負極１１を使用した。 In this example, the discharge cycle characteristics of two Si-based samples at a charging current density of 210 [mA / g] were obtained, and the discharge cycle characteristics of the Si-based samples were compared. That is, the discharge cycle characteristics were determined from the charge / discharge curves of each sample measured under a current density condition of 210 [mA / g]. The change accompanying the charge / discharge cycle of the discharge capacity (capacity per Si weight) of the Si nanoparticles obtained here and the charge / discharge cycle of the discharge capacity per Si weight of the Si nanoparticles modified with the carbon-based material 2 Compared. As the sample, the negative electrode 11 having C—Si (100) 9 [h] 300 [W] shown in the middle of FIG. 17, which was excellent in cycle stability under the measurement of 420 [mA / g], was used. did.
　図１９の左図及び右図において、縦軸は電位（Potential／［ＶvsＬｉ／Ｌｉ+］であり、横軸は放電容量（Capacity）[ｍＡｈ／（ｇ－Ｓｉ）］である。図１７の左図及び中図に示した未修飾のＳｉナノ粒子４とＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料に関して、電流密度を２１０ｍＡ／ｇに設定して測定を比較した。図１９の左図及び右図に示す充放電曲線において、右側のカーブから順に、サイクル１回目から１０回目の充放電曲線である。 19, the vertical axis represents potential (Potential / [VvsLi / Li + ] and the horizontal axis represents discharge capacity (mAh / (g-Si)]. The unmodified Si nanoparticles 4 and the C-Si (100) 9 [h] 300 [W] sample shown in the figure and the middle figure were compared with the current density set at 210 mA / g. In the charging / discharging curves shown in the left and right diagrams, the charging and discharging curves in the first cycle to the tenth cycle are sequentially performed from the right curve.
　図１９の左図に示す比較例１１は、２１０［ｍＡ／ｇ］の電流密度条件で測定した、Ｓｉナノ粒子４のままの負極１１の充放電曲線である。Ｓｉナノ粒子４のままの負極１１の充電曲線は、Ｓｉナノ粒子４がＬｉを吸蔵する合金反応（Ｓｉ＋ｘＬｉ→ＬｉｘＳｉ）によるものである。初回の充電曲線には、電解液分解により生じる界面皮膜（ＳＥＩ）形成の容量も含まれる。 19 is a charge / discharge curve of the negative electrode 11 with the Si nanoparticles 4 as measured under a current density condition of 210 [mA / g]. The charging curve of the negative electrode 11 with the Si nanoparticles 4 remains is due to an alloy reaction (Si + xLi → LixSi) in which the Si nanoparticles 4 occlude Li. The initial charge curve also includes the capacity of the interfacial film (SEI) formation caused by electrolyte decomposition.
　図１９の左図及び右図に示す充放電曲線において、電位が小さくなるにつれて、容量が増えている右下がりの特性が充電時の曲線（充電曲線）である。負極１１の充電曲線は、Ｓｉナノ粒子４とＬｉとの合金反応（Ｓｉ＋ｘＬｉ→ＬｉｘＳｉ）によるものである。当該合金反応は、Ｌｉ基準の電位で通常０．３［Ｖ］以下で生じ、図１９の各図に各々示す充電曲線における０．３［Ｖ］以下の横ばいの部分（容量増加）は、この反応が起きていることを示している。 In the charge / discharge curves shown in the left and right diagrams of FIG. 19, the downward-sloping characteristic in which the capacity increases as the electric potential decreases is a curve (charge curve) during charging. The charging curve of the negative electrode 11 is due to an alloy reaction (Si + xLi → LixSi) between the Si nanoparticles 4 and Li. The alloy reaction usually occurs at a potential based on Li of 0.3 [V] or less, and a leveling portion (capacity increase) of 0.3 [V] or less in the charging curve shown in each diagram of FIG. Indicates that a reaction is taking place.
　また、図１９の左図及び右図に示す充放電曲線において、電位が大きくなるにつれて容量が大きくなる右上がりの曲線が放電時の曲線（放電曲線）である。負極１１の放電曲線は、Ｌｉを離脱する脱合金反応（ＬｉｘＳｉ→Ｓｉ＋ｘＬｉ）によるものである。 Further, in the charge / discharge curves shown in the left and right diagrams of FIG. 19, a curve that rises to the right and increases in capacity as the potential increases is a curve during discharge (discharge curve). The discharge curve of the negative electrode 11 is due to a dealloying reaction (LixSi → Si + xLi) that releases Li.
　図１９の右図に示す実施例３９は、２１０［ｍＡ／ｇ］の電流密度条件で測定した、コーティング処理後（熱処理前）の負極１１の充放電曲線である。図１９の右図に示す充放電曲線は、図１９の左図に示した充放電曲線に比べて右側にシフトしている。 19 is a charge / discharge curve of the negative electrode 11 after coating treatment (before heat treatment), measured under a current density condition of 210 [mA / g]. The charge / discharge curve shown in the right diagram of FIG. 19 is shifted to the right as compared to the charge / discharge curve shown in the left diagram of FIG.
　この例では、２１０［ｍＡ／ｇ］の電流密度条件において、比較例１１及び実施例３９共に充電電流密度４２０［ｍＡ／ｇ］の条件よりも、充放電容量が増加する。しかし、実施例３９に示したＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料は、Ｓｉナノ粒子４のままの負極１１の充放電特性に比べて、その充放電曲線が共に右側にシフトしており、Ｓｉナノ粒子４より大幅に容量が大きくなっていることがわかった。なお、図２０では、負極１１のサイクル安定性について説明する。 In this example, in the current density condition of 210 [mA / g], the charge / discharge capacity increases in both Comparative Example 11 and Example 39 than in the condition of the charging current density of 420 [mA / g]. However, the C—Si (100) 9 [h] 300 [W] sample shown in Example 39 has both charge and discharge curves on the right side compared to the charge and discharge characteristics of the negative electrode 11 with the Si nanoparticles 4 as it is. It was found that the capacity was significantly larger than that of the Si nanoparticles 4. In FIG. 20, the cycle stability of the negative electrode 11 will be described.
　続いて、図２０を参照して、Ｓｉ系試料のサイクル特性について説明する。この例では、２１０［ｍＡ／ｇ］の電流密度条件で測定した、未修飾のＳｉナノ粒子系試料、Ｃ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料の２つの負極１１について、これらのサイクル特性について、充放電動作を１回～３０回を行って、充放電特性を比較（考察）した。 Subsequently, the cycle characteristics of the Si-based sample will be described with reference to FIG. In this example, two negative electrodes 11 of an unmodified Si nanoparticle sample and a C—Si (100) 9 [h] 300 [W] sample measured under a current density condition of 210 [mA / g] were used. Regarding the cycle characteristics, charge / discharge operations were performed 1 to 30 times, and the charge / discharge characteristics were compared (considered).
　図２０において、縦軸はＳｉ重量当りの放電容量（Capacity）[ｍＡｈ／（ｇ－Ｓｉ）］であり、横軸は充放電の回数（Cycle Number）である。図２０に示す丸印の比較例１２は、負極１１がＳｉナノ粒子４のみの場合のサイクル特性である。このサイクル特性によれば、低い電流密度においても、Ｓｉナノ粒子４はサイクルと共に急激に放電容量が低下した。すなわち、初回で２０００［ｍＡｈ／（ｇ－Ｓｉ）］と放電容量が高いが、１５回目以降で１００［ｍＡｈ／ｇ］以下と急激に放電容量が低くなった。３０回ではほとんど容量を示さなかった。 In FIG. 20, the vertical axis represents discharge capacity per Si weight (Capacity) [mAh / (g-Si)], and the horizontal axis represents the number of charge / discharge cycles (Cycle Number). The comparative example 12 of the round mark shown in FIG. 20 is a cycling characteristic in case the negative electrode 11 is only Si nanoparticle 4. FIG. According to this cycle characteristic, even at a low current density, the discharge capacity of the Si nanoparticles 4 suddenly decreased with the cycle. That is, the discharge capacity was as high as 2000 [mAh / (g-Si)] for the first time, but rapidly decreased to 100 [mAh / g] or less after the 15th time. 30 times showed almost no capacity.
　これに対して、楕円印の実施例４０は、負極１１がＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料で、コーティング処理後のＳｉナノ粒子のサイクル特性である。コーティング処理後のサイクル特性によれば、初回で３２５０［ｍＡｈ／（ｇ－Ｓｉ）］と放電容量が高く、１５回目で放電容量１０００［ｍＡｈ／（ｇ－Ｓｉ）］以上を維持していた。３５回以降はほぼ一定で６０回後も放電容量７００［ｍＡｈ／（ｇ－Ｓｉ）］を維持していた。因みに、既存のグラファイト負極材料は放電容量が３７２～３５０［ｍＡｈ／ｇ］である。 On the other hand, in Example 40 indicated by an ellipse, the negative electrode 11 is a C—Si (100) 9 [h] 300 [W] sample, and the cycle characteristics of the Si nanoparticles after the coating treatment. According to the cycle characteristics after the coating treatment, the discharge capacity was as high as 3250 [mAh / (g-Si)] at the first time, and the discharge capacity was maintained at 1000 [mAh / (g-Si)] or more at the 15th time. After 35 times, the discharge capacity was almost constant and after 60 times the discharge capacity 700 [mAh / (g-Si)] was maintained. Incidentally, the existing graphite negative electrode material has a discharge capacity of 372 to 350 [mAh / g].
　上述した２１０［ｍＡ／ｇ］の電流密度条件においても、Ｓｉナノ粒子４は、比較例１２に示したようにサイクル回数の増加とともに急激に放電容量が減少し、２０サイクル後はほとんど容量を示さなかった。これに対して、実施例４０に示したＣ－Ｓｉ（１００）９［ｈ］３００［Ｗ］試料は、サイクル初期の放電容量が未修飾のＳｉナノ粒子４よりも大幅に向上した。また、３５サイクル以降は７００［ｍＡ／ｇ］の容量で、５０サイクル以上においても、７００［ｍＡｈ／ｇ］の大容量を安定して維持した。本コーティング処理により、サイクル安定性が向上することは明らかであり、７００［ｍＡｈ／ｇ］と安定した放電容量の負極１１を製造することを達成できた。 Even under the current density condition of 210 [mA / g] described above, the Si nanoparticles 4 rapidly decreased in discharge capacity as the number of cycles increased, as shown in Comparative Example 12, and almost exhibited capacity after 20 cycles. There wasn't. On the other hand, the C—Si (100) 9 [h] 300 [W] sample shown in Example 40 significantly improved the discharge capacity at the beginning of the cycle as compared with the unmodified Si nanoparticles 4. Further, the capacity was 700 [mA / g] after 35 cycles, and the large capacity of 700 [mAh / g] was stably maintained even after 50 cycles. It is clear that the cycle stability is improved by this coating treatment, and it was possible to produce the negative electrode 11 having a stable discharge capacity of 700 [mAh / g].
　このように第２の実施形態に係る負極１１によれば、活物質１としてのＳｉナノ粒子４の全表面あるいはその一部表面にカーボン系物質２が覆われた電極材料を用いている。このカーボン系物質２は、超音波が、周波数＝４０ｋＨｚ、出力２００～３００［Ｗ］、及び照射時間３［ｈ］～９［ｈ］の条件で、ｏ－ＤＣＢ３に照射され、当該ｏ－ＤＣＢ３のラジカル反応により生成されたものである。 Thus, according to the negative electrode 11 according to the second embodiment, the electrode material in which the carbon-based material 2 is covered on the entire surface or a part of the surface of the Si nanoparticles 4 as the active material 1 is used. The carbon-based material 2 is irradiated with o-DCB3 under the conditions of an ultrasonic frequency of 40 kHz, an output of 200 to 300 [W], and an irradiation time of 3 [h] to 9 [h]. It is produced by the radical reaction.
　この構成によって、Ｓｉナノ粒子４の結晶の隅々までカーボン系物質２が浸入（被着）することにより、当該Ｓｉナノ粒子４の結晶構造が合金化や脱合金化反応から保護され、かつ、導電性に優れた負極１１を提供できるようになった。 With this configuration, the carbon-based material 2 penetrates (deposits) into every corner of the crystal of the Si nanoparticle 4, so that the crystal structure of the Si nanoparticle 4 is protected from alloying and dealloying reactions, and The negative electrode 11 excellent in conductivity can be provided.
　また、負極１１の製造方法によれば、強力な超音波照射により有機溶媒中にＳｉナノ粒子４を分散させると同時に有機溶媒分子を重合・カーボン化させることにより、Ｓｉ／カーボンの複合体を合成、すなわち、Ｓｉナノ粒子４の表面にナノメートルオーダーの厚みのカーボンを形成できるようになった。カーボン系物質２によるＳｉナノ粒子４の表面修飾に用いる有機溶媒はジクロロベンゼンに限定されることはなく、他の芳香族系化合物でもよい。 Moreover, according to the manufacturing method of the negative electrode 11, the Si / carbon composite is synthesized by dispersing the Si nanoparticles 4 in the organic solvent by strong ultrasonic irradiation and simultaneously polymerizing and carbonizing the organic solvent molecules. That is, carbon having a thickness of nanometer order can be formed on the surface of the Si nanoparticles 4. The organic solvent used for the surface modification of the Si nanoparticles 4 with the carbon-based material 2 is not limited to dichlorobenzene, and may be other aromatic compounds.
　しかも、カーボン系物質２による表面修飾方法は、非重合性の有機溶媒（ジクロロベンゼン）にＳｉナノ粒子４を加え、超音波を照射するだけの簡単な方法であって、簡便かつ大量生産にも利用できる方法である。また、超音波出力や、超音波照射時間、活物質１の濃度等に依存して、カーボン生成量を変化させることができる。 In addition, the surface modification method using the carbon-based material 2 is a simple method in which Si nanoparticles 4 are added to a non-polymerizable organic solvent (dichlorobenzene) and irradiated with ultrasonic waves. It is an available method. In addition, the amount of carbon produced can be changed depending on the ultrasonic output, the ultrasonic irradiation time, the concentration of the active material 1, and the like.
　カーボン系物質２による表面修飾方法は、電池の活物質１の表面ナノコーティング方法として実用的にもインパクトの高い技術であり、循環装置等の流通式装置でカーボン修飾を行うことにより、負極１１を大量に生産できる。また、活物質１の表面ナノコーティングにより導電性が付与されるとともに、充放電サイクル特性の安定性向上が図れる。 The surface modification method using the carbon-based material 2 is a technology that has a high impact in practical use as a surface nano-coating method for the active material 1 of the battery. By performing carbon modification with a flow-type device such as a circulation device, the negative electrode 11 is formed. Can be produced in large quantities. In addition, conductivity is imparted by the surface nano-coating of the active material 1, and stability of charge / discharge cycle characteristics can be improved.
　本発明に係るカーボン系物質２の表面修飾方法は、合金系負極活物質の安定化及び負極にも効果がある。しかも、負極１１のＳｉ結晶構造の崩壊を抑制でき、合金化及び脱合金化の可逆特性が良好に行われる。これにより、カーボン系物質２で隅々まで覆われ保護されたＳｉナノ粒子４をもつ負極は、Ｌｉイオン二次電池の高容量化及び、高容量のＬｉイオン二次電池の製造に大きく寄与する。 The surface modification method for the carbon-based material 2 according to the present invention is also effective for stabilizing the alloy-based negative electrode active material and the negative electrode. In addition, the collapse of the Si crystal structure of the negative electrode 11 can be suppressed, and the reversible characteristics of alloying and dealloying are favorably performed. As a result, the negative electrode having Si nanoparticles 4 covered and protected in every corner by the carbon-based material 2 greatly contributes to the increase in capacity of Li-ion secondary batteries and the production of high-capacity Li-ion secondary batteries. .
　＜第３の実施形態＞
　［正極］
　本発明者らは、大容量の正極用の電極材料として注目されているＬｉ2ＭｎＯ3系粒子にも、カーボン性物質２による表面修飾方法を適用し、正極活物質＋超音波カーボンコート法により充放電特性が向上することも明らかにした。 <Third Embodiment>
[Positive electrode]
The present inventors also applied a surface modification method using the carbonaceous material 2 to Li 2 MnO 3 -based particles that have been attracting attention as an electrode material for a large-capacity positive electrode by a positive electrode active material + ultrasonic carbon coating method. It was also clarified that the charge / discharge characteristics were improved.
　ここで、図２１を参照して、第３の実施形態としての正極用の電極材料の形成方法について説明する。正極１２については、図２５を参照されたい。この例では、正極活物質＋超音波カーボンコート法により、ＬＭＯ－ＬＮＭＣＯ粒子の炭化を更に進めることができ、正極用の電極材料の導電性を高めることができる。 Here, with reference to FIG. 21, the formation method of the electrode material for positive electrodes as 3rd Embodiment is demonstrated. Refer to FIG. 25 for the positive electrode 12. In this example, carbonization of the LMO-LNMCO particles can be further advanced by the positive electrode active material + ultrasonic carbon coating method, and the conductivity of the electrode material for the positive electrode can be increased.
　本例は、電極材料１０の一例の正極用の電極材料、即ち正極材料である。正極材料は、活物質１である正極活物質の全表面あるいはその一部表面がカーボン系物質２により覆われている。正極１２は、正極用の電極材料１０を正極集電体上に設けたものである。正極活物質には、例えば、Ｌｉ2ＭｎＯ3系の活物質１が使用される。 This example is an electrode material for a positive electrode as an example of the electrode material 10, that is, a positive electrode material. In the positive electrode material, the entire surface or a part of the surface of the positive electrode active material which is the active material 1 is covered with the carbon-based material 2. The positive electrode 12 is obtained by providing a positive electrode material 10 on a positive electrode current collector. For example, Li 2 MnO 3 -based active material 1 is used as the positive electrode active material.
　この例では、Ｌｉ2ＭｎＯ3系活物質から構成される正極活物質がカーボン系物質２により覆われて正極材料が構成される。このためＬｉ2ＭｎＯ3系の活物質に比べて、より高容量を示すと共に高レート特性が得られるＬｉ2ＭｎＯ3系活物質／カーボンの複合体を含む正極材料１２を提供できる。本発明に係る正極材料によれば、全表面あるいはその一部表面がカーボン系物質２により覆われた正極活物質からなるので、正極活物質の安定化に大きく寄与する。 In this example, a positive electrode active material composed of a Li 2 MnO 3 based active material is covered with a carbon based material 2 to form a positive electrode material. Therefore in comparison with the active material of Li 2 MnO 3 system can provide a cathode material 12 including a high-rate characteristic Li 2 MnO 3 is obtained based active material / carbon composites with showing a higher capacity. According to the positive electrode material according to the present invention, the entire surface or a part of the surface thereof is made of the positive electrode active material covered with the carbon-based material 2, which greatly contributes to the stabilization of the positive electrode active material.
　［正極活物質＋超音波カーボンコート法］
　本発明に係る正極材料の形成方法は、カーボン系物質２によるＬｉ2ＭｎＯ3系活物質の表面修飾方法である。ｏ－ジクロロベンゼン中に、活物質１としてＬｉ2ＭｎＯ3系粒体を加えた後例えば超音波照射することにより、Ｌｉ2ＭｎＯ3系粒子を超音波分散させるとともにＬｉ2ＭｎＯ3系粒子の全表面あるいはその一部表面をナノメートルオーダーの厚みのカーボン系物質２でコーティングしてＬｉ2ＭｎＯ3系活物質／Ｃ複合体を得る（Ｌｉ2ＭｎＯ3粒子／カーボン複合体から成る試料の作製）。 [Positive electrode active material + ultrasonic carbon coating method]
The method for forming a positive electrode material according to the present invention is a method for surface modification of a Li 2 MnO 3 -based active material with a carbon-based material 2. During o- dichlorobenzene, by irradiating for example ultrasound after addition of Li 2 MnO 3 -based grain body as the active material 1, with ultrasonically dispersed Li 2 MnO 3 system particles of Li 2 MnO 3 system particles all The surface or a part of the surface is coated with a carbon-based material 2 having a thickness on the order of nanometers to obtain a Li 2 MnO 3 -based active material / C composite (preparation of a sample composed of Li 2 MnO 3 particles / carbon composite) .
　この例では、５００［ｍＬ］のｏ－ＤＣＢ３（以下ｏ－ＤＣＢ３を単にＣともいう）に、仕込み量として、１［ｇ］の０．５Ｌｉ2ＭｎＯ3－０．５Ｌｉ2Ｎｉ1/3Ｃｏ1/3Ｏ2（以下でＬＭＯ－ＬＮＭＣＯという）の粉体を混合した。そして、アルゴン（Ａｒ）雰囲気で、攪拌下、次の照射件下で超音波を照射した。照射条件は、超音波の出力が３００［Ｗ］、その周波数が４０［ｋＨｚ］及び、その照射時間が９［ｈ］であった。 In this example, 500 [mL] of o-DCB3 (hereinafter, o-DCB3 is also simply referred to as C) is charged as 1 [g] of 0.5Li 2 MnO 3 -0.5Li 2 Ni 1/3 Co. A powder of 1/3 O 2 (hereinafter referred to as LMO-LNMCO) was mixed. Then, in an argon (Ar) atmosphere, ultrasonic waves were irradiated under stirring and under the following irradiation conditions. The irradiation conditions were an ultrasonic output of 300 [W], a frequency of 40 [kHz], and an irradiation time of 9 [h].
　これらを表面修飾条件にして、まず、図２１に示す工程＃１１で、石英セル６２内に５００［ｍＬ］のｏ－ＤＣＢ３を入れると共に、仕込み量（導入量）＝１［ｇ］のＬＭＯ－ＬＮＭＣＯ粒子の粉体を加えた（混合した）。以下でｏ－ＤＣＢ３内にＬＭＯ－ＬＮＭＣＯ粒子が仕込まれたものを試料(SAMPLE)という。 Using these as surface modification conditions, first, in Step # 11 shown in FIG. 21, 500 [mL] of o-DCB3 is placed in the quartz cell 62, and the charged amount (introduced amount) = 1 [g] of LMO- LNMCO particle powder was added (mixed). Hereinafter, a sample in which LMO-LNMCO particles are charged in o-DCB3 is referred to as a sample (SAMPLE).
　次に、工程＃１２で試料の超音波処理を行った。この例では、超音波の条件について、周波数ｆを４０［ｋＨｚ］に、出力を３００［Ｗ］に、照射時間を９［ｈ］に各々設定した。ＬＭＯ－ＬＮＭＣＯ粒子をｏ－ＤＣＢ３に分散させ、超音波を照射してから３０分経過した後、無色透明のｏ－ＤＣＢ３が黄色に変化した。 Next, the sample was sonicated in step # 12. In this example, regarding the ultrasonic conditions, the frequency f was set to 40 [kHz], the output was set to 300 [W], and the irradiation time was set to 9 [h]. After 30 minutes had passed since the LMO-LNMCO particles were dispersed in o-DCB3 and irradiated with ultrasonic waves, the colorless and transparent o-DCB3 turned yellow.
　石英セル６２内はｏ－ＤＣＢ３の黄色に変色後、数時間を経過した後に黒色に変化した。このとき、ｏ－ＤＣＢ３のラジカル反応により、有機溶媒分子が重合・カーボン化した。これにより生じたカーボン系物質２がＬＭＯ－ＬＮＭＣＯ粒子（活物質１）を表面処理し、後述するようにＬＭＯ－ＬＮＭＣＯ粒子の表面から炭素Ｃを検出することができた。ここに、ＬＭＯ－ＬＮＭＣＯ粒子を含む黒色に変化した溶液が得られた。 In the quartz cell 62, the color of the o-DCB3 changed to yellow and then changed to black after several hours. At this time, organic solvent molecules were polymerized and carbonized by the radical reaction of o-DCB3. The resulting carbon-based material 2 surface-treated the LMO-LNMCO particles (active material 1), and carbon C could be detected from the surface of the LMO-LNMCO particles as described later. Here, a black-colored solution containing LMO-LNMCO particles was obtained.
　更に、工程＃１３で遠心分離器を用いて試料の遠心分離を行った。分離条件は、遠心分離器の回転数を１００００［ｒｐｍ］に設定し、その分離時間を１時間に設定した。ＬＭＯ－ＬＮＭＣＯ粒子を含む黒色に変化した溶液を１００００［ｒｐｍ］で、１時間遠心分離して沈殿物を回収した。 Furthermore, the sample was centrifuged using a centrifuge in step # 13. Separation conditions were set such that the rotational speed of the centrifuge was set to 10,000 [rpm] and the separation time was set to 1 hour. The solution which turned to black containing LMO-LNMCO particles was centrifuged at 10,000 [rpm] for 1 hour to collect the precipitate.
　その後、工程＃１４で、先に回収された試料を温度１２０［℃］により乾燥した。この乾燥処理により、高温度（例えば、３００［℃］～５００［℃］）による熱処理を行う前のＣ－ＬＭＯ－ＬＮＭＣＯ粒子を含む黒色の試料が得られた。 Thereafter, in step # 14, the previously collected sample was dried at a temperature of 120 [° C.]. By this drying treatment, a black sample containing C-LMO-LNMCO particles before heat treatment at a high temperature (for example, 300 [° C.] to 500 [° C.]) was obtained.
　更に、工程＃１５で熱処理を行う場合と、熱処理を行わない場合とで工程を分岐した。熱処理を行わない場合は、工程＃１６に移行して、熱処理前の試料に表記を付す表記処理を実行した。ここで、上記工程＃１１～＃１４の処理を経験した場合に、「Ｃ」を最初に付し、熱処理を行っていない試料を（３）式、すなわち、
　　　　　　　　　Ｃ－ＬＭＯ－ＬＮＭＣＯ・・・・・（３）
と表記して、各実施例において電気化学分析した。 Furthermore, the process was branched depending on whether the heat treatment was performed in step # 15 or not. When the heat treatment is not performed, the process proceeds to step # 16, and a notation process is performed in which a notation is given to the sample before the heat treatment. Here, when experiencing the processes of the above steps # 11 to # 14, “C” is attached first, and the sample not subjected to the heat treatment is expressed by the equation (3), that is,
C-LMO-LNMCO (3)
In each example, electrochemical analysis was performed.
　試料の熱処理を行う場合は、工程＃１７に移行して、カーボン系物質２で表面処理されたＣ－ＬＭＯ－ＬＮＭＣＯ粒子（活物質１）を熱処理した。熱処理条件は、電気管状炉で温度が３００～５００［℃］、熱処理時間が３～１２時間保持、Ａｒ雰囲気で試料を焼成した。熱処理前のＣ－ＬＭＯ－ＬＮＭＣＯ粒子に比べてより高容量を示すと共に高レート特性が得られる正極材料を提供できた。 When performing heat treatment of the sample, the process proceeds to Step # 17, and the C-LMO-LNMCO particles (active material 1) surface-treated with the carbon-based material 2 are heat-treated. The heat treatment conditions were as follows: the temperature was 300 to 500 [° C.] in an electric tubular furnace, the heat treatment time was maintained for 3 to 12 hours, and the sample was fired in an Ar atmosphere. It was possible to provide a positive electrode material that showed higher capacity and higher rate characteristics than C-LMO-LNMCO particles before heat treatment.
　その後、工程＃１８で熱処理後の試料に表記を付す表記処理を実行した。ここで、工程＃１１～１４の処理）を経験した場合に「Ｃ」を最初に付した。Ｃ－ＬＭＯ－ＬＮＭＣＯ粒子の熱処理時の温度をＨ［℃］（式中［℃］を省略する）とし、熱処理時間をＹ［ｈ］（式中［ｈ］を省略する）としたとき、熱処理後の試料を（４）式、すなわち、
　　　　　　　　Ｃ－ＬＭＯ－ＬＮＭＣＯ（Ｈ－Ｙ）・・・・（４）
と表記して、各実施例において電気化学分析した。 Then, the notation process which attaches description to the sample after heat processing in process # 18 was performed. Here, “C” was added first when experiencing the processes of Steps # 11 to # 14). When the temperature during the heat treatment of C-LMO-LNMCO particles is H [° C.] (where [° C.] is omitted) and the heat treatment time is Y [h] (where [h] is omitted), the heat treatment The later sample is expressed by equation (4), that is,
C-LMO-LNMCO (HY) (4)
In each example, electrochemical analysis was performed.
　続いて、図２２を参照して、Ｃ－ＬＭＯ－ＬＮＭＣＯ（３００－１２）試料のＴＥＭ観察について説明する。図２２に示すＣ－ＬＭＯ－ＬＮＭＣＯ（３００－１２）試料のＴＥＭ像によれば、活物質１として用いたＬＭＯ－ＬＮＭＣＯ粒子は、３０－５０［ｎｍ］程度の平均粒子径を有していた。 Subsequently, TEM observation of the C-LMO-LNMCO (300-12) sample will be described with reference to FIG. According to the TEM image of the C-LMO-LNMCO (300-12) sample shown in FIG. 22, the LMO-LNMCO particles used as the active material 1 had an average particle diameter of about 30-50 [nm]. .
　正極用の電極材料として用いたＣ－ＬＭＯ－ＬＮＭＣＯ粒子は、結晶構造であること示す格子像が見られた。温度３００［℃］及び１２時間の熱処理後においても、Ｃ－ＬＭＯ－ＬＮＭＣＯ粒子の表面が厚み数ｎｍ程度のアモルファス相で覆われていることもわかった。カーボン系物質２は厚み数ｎｍ程度を有し、ＬＭＯ－ＬＮＭＣＯ粒子の表面をコーティングしていることがわかった。 A lattice image showing that the C-LMO-LNMCO particles used as the positive electrode material had a crystalline structure was observed. It was also found that the surface of the C-LMO-LNMCO particles was covered with an amorphous phase having a thickness of several nanometers even after the heat treatment at a temperature of 300 [° C.] and 12 hours. It was found that the carbon-based material 2 has a thickness of about several nm and coats the surface of the LMO-LNMCO particles.
　ラマンスペクトル測定や組成分析結果と合わせて考えると、このアモルファス相はカーボン系物質２からなる。また、粒子間隙にもアモルファス相の形成が見られ、正極用の電極材料においても、超音波処理によるカーボンコーティングが確認された。これにより、ＬＭＯ－ＬＮＭＣＯ粒子の表面にナノメートルオーダーの厚みのカーボン系物質２を均一に形成できた。 The amorphous phase is composed of the carbon-based material 2 when considered together with the results of Raman spectrum measurement and composition analysis. In addition, formation of an amorphous phase was also observed in the particle gap, and carbon coating by ultrasonic treatment was confirmed also in the electrode material for the positive electrode. As a result, the carbonaceous material 2 having a thickness of nanometer order could be uniformly formed on the surface of the LMO-LNMCO particles.
　ここで、図２３を参照して、Ｃ－ＬＭＯ－ＬＮＭＣＯ（３００－１２）試料等のＸＲＤパターンについて説明する。この例で、試料にＬＭＯ－ＬＮＭＣＯ粒子が存在しているか否かを調べるために、Ｃ－ＬＭＯ－ＬＮＭＣＯ（Ｈ－Ｙ）試料等のＸＲＤパターンを取得した。取得条件は、対陰極：ＣｕＫα、スキャンスピード：２．０［degree／min］、管電圧：４０［ｋＶ］、管電流：４０［ｍＡ］、サンプリング間隔：０．０１０［degree］である。図２３において、縦軸はＸ線の回折強度（Intensity）であり、横軸はＸ線の入射角［２θ／degree（ＣｕＫα）］である。 Here, the XRD pattern of the C-LMO-LNMCO (300-12) sample or the like will be described with reference to FIG. In this example, an XRD pattern of a C-LMO-LNMCO (HY) sample or the like was acquired in order to examine whether or not LMO-LNMCO particles were present in the sample. The acquisition conditions are the counter cathode: CuKα, scan speed: 2.0 [degree / min], tube voltage: 40 [kV], tube current: 40 [mA], and sampling interval: 0.010 [degree]. In FIG. 23, the vertical axis represents the X-ray diffraction intensity (Intensity), and the horizontal axis represents the X-ray incident angle [2θ / degree (CuKα)].
　図２３に示す比較例１３はコーティング処理無し（未修飾）のＬＭＯ－ＬＮＭＣＯ粒子のＸＲＤパターンである。実施例４１はコーティング処理のみのＣ－ＬＭＯ－ＬＮＭＣＯのＸＲＤパターンである。実施例４２はコーティング＋熱処理のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－１２）試料のＸＲＤパターンである。実施例４３はコーティング＋熱処理のＣ－ＬＭＯ－ＬＮＭＣＯ（４００－１２）試料のＸＲＤパターンである。実施例４４はコーティング＋熱処理のＣ－ＬＭＯ－ＬＮＭＣＯ（５００－１２）試料のＸＲＤパターンである。 23 is an XRD pattern of LMO-LNMCO particles without coating treatment (unmodified). Example 41 is an XRD pattern of C-LMO-LNMCO with only coating treatment. Example 42 is an XRD pattern of a C + LMO-LNMCO (300-12) sample with coating + heat treatment. Example 43 is an XRD pattern of a C + LMO-LNMCO (400-12) sample with coating plus heat treatment. Example 44 is an XRD pattern of a C + LMO-LNMCO (500-12) sample with coating plus heat treatment.
　各超音波処理条件で得た試料（実施例４１～４４）において、いずれも、未修飾のＬＭＯ－ＬＮＭＣＯ粒子と同じ回折ピークが観測され、ＬＭＯ－ＬＮＭＣＯ結晶構造が保持されていることが確認できた。 In each of the samples (Examples 41 to 44) obtained under each sonication condition, the same diffraction peak as that of the unmodified LMO-LNMCO particles was observed, and it was confirmed that the LMO-LNMCO crystal structure was retained. It was.
　しかしながら、Ｃ－ＬＭＯ－ＬＮＭＣＯ（４００－１２）、Ｃ－ＬＭＯ－ＬＮＭＣＯ（５００－１２）では、ＬＭＯ－ＬＮＭＣＯに帰属されない不純物相のピーク（未同定）が確認された。従って、４００［℃］以上では、結構構造の崩壊や不純物相の影響などが危惧されるため、以下の正極活物質＋超音波カーボンコート法における熱処理条件は３００［℃］とした。 However, in C-LMO-LNMCO (400-12) and C-LMO-LNMCO (500-12), an impurity phase peak (unidentified) that was not assigned to LMO-LNMCO was confirmed. Therefore, at 400 [° C.] or higher, there is a concern about the collapse of the structure or the influence of the impurity phase. Therefore, the heat treatment conditions in the following positive electrode active material + ultrasonic carbon coating method were set to 300 [° C.].
　続いて、図２４を参照して、Ｃ－ＬＭＯ－ＬＮＭＣＯ系試料（３００［℃］）のラマンスペクトルについて説明する。この例で、カーボン系物質２が良好にコーティングされているか否かを調べるために、Ｃ－ＬＭＯ－ＬＮＭＣＯ系試料（３００［℃］）のラマンスペクトルを取得した。その際に、ラマンスペクトル装置（日本分光ＪＡＳＣＯＲＭＰ－２１０（レーザー光波長：５３２［ｎｍ］））を使用した。取得条件は、露光時間が１０secで、積算回数が２０回で、波数が１００～２０００［ｃｍ-1］とした。 Next, the Raman spectrum of the C-LMO-LNMCO sample (300 [° C.]) will be described with reference to FIG. In this example, a Raman spectrum of a C-LMO-LNMCO sample (300 [° C.]) was obtained in order to check whether or not the carbon-based material 2 was satisfactorily coated. At that time, a Raman spectrum apparatus (JASCO Corp. JASCORMP-210 (laser beam wavelength: 532 [nm])) was used. The acquisition conditions were an exposure time of 10 sec, an integration count of 20, and a wave number of 100 to 2000 [cm −1 ].
　図２４において、縦軸は強度（Intensity：［Arb.　unit］）で、横軸はラマンシフト（Raman　shift：［ｃｍ-1］である。なお、図２４は１２００～２０００［ｃｍ-1］領域のスペクトルを示している。図２４に示す比較例１４はコーティング処理無し（未修飾）のＬＭＯ－ＬＮＭＣＯ粒子のラマンスペクトルである。比較例１４では、カーボン系物質２の由来のピークが確認されない。 24, the vertical axis is intensity (Intensity: [Arb. Unit]), and the horizontal axis is Raman shift (Raman shift: [cm −1 ]. Note that FIG. 24 shows 1200 to 2000 [cm −1 ] region. 24 is a Raman spectrum of LMO-LNMCO particles without coating treatment (unmodified), and no peak derived from the carbonaceous material 2 is confirmed in Comparative Example 14.
　実施例４５はコーティング処理のみのＣ－ＬＭＯ－ＬＮＭＣＯ粒子のラマンスペクトルである。実施例４６はコーティング＋熱処理のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－３）試料のラマンスペクトルである。実施例４７はコーティング＋熱処理のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－６）試料のラマンスペクトルである。実施例４８はコーティング＋熱処理のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－１２）試料のラマンスペクトルである。 Example 45 is a Raman spectrum of C-LMO-LNMCO particles that are only coated. Example 46 is the Raman spectrum of a C + LMO-LNMCO (300-3) sample with coating + heat treatment. Example 47 is the Raman spectrum of a C + LMO-LNMCO (300-6) sample with coating + heat treatment. Example 48 is the Raman spectrum of a C + LMO-LNMCO (300-12) sample with coating plus heat treatment.
　上述の実施例４５のＣ－ＬＭＯ－ＬＮＭＣＯ、及び、実施例４６～４８のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－Ｙ）の試料では、未修飾ＬＭＯ－ＬＮＣＭＯでは観測されない１５８０、１３６０ｃｍ-1付近のカーボン由来のピークが見られており、超音波照射および３００［℃］熱処理によりカーボン系物質２が生成していることが確認できた。 In the sample of C-LMO-LNMCO of Example 45 and C-LMO-LNMCO (300-Y) of Examples 46 to 48, carbons near 1580 and 1360 cm −1 that are not observed with unmodified LMO-LNCMO The origin peak was seen, and it was confirmed that the carbon-based material 2 was produced by ultrasonic irradiation and 300 [° C.] heat treatment.
　また、１５８０ｃｍ-1付近のピーク（Ｇバンド）はグラファイト性カーボン、１３６０ｃｍ-1付近のピーク（Ｄバンド）はアモルファス性カーボン由来のピークである。いずれの超音波照射条件においても、ＬＭＯ－ＬＮＭＣＯ粒子＋カーボン系物質２の複合体が生成されていることが確認できた。すなわち、実施例４５～４８において、カーボン系物質２が生成していることがわかった。 Further, 1580 cm -1 vicinity of the peak (G band) of graphitic carbon, 1360 cm -1 vicinity of the peak (D band) is the peak derived from amorphous carbon. It was confirmed that a composite of LMO-LNMCO particles + carbon-based material 2 was generated under any ultrasonic irradiation condition. That is, it was found that in Examples 45 to 48, the carbon-based material 2 was generated.
　ここで、Ｃ－ＬＭＯ－ＬＮＭＣＯ系試料の修飾組成について説明する。Ｃ－ＬＭＯ－ＬＮＭＣＯ系試料の修飾組成については、有機元素分析により、カーボン系物質２の組成を調べた。この例では、試料に含まれる炭素（Ｃ）、水素（Ｈ）及び窒素（Ｎ）の含有重量［ｗｔ％］を調べて、修飾の組成を分析した。熱処理前のＣ－ＬＭＯ－ＬＮＭＣＯ試料、熱処理後のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－３）、Ｃ－ＬＭＯ－ＬＮＭＣＯ（３００－６）及び、Ｃ－ＬＭＯ－ＬＮＭＣＯ（３００－１２）の各々の試料の有機元素分析結果を表３に示した。 Here, the modified composition of the C-LMO-LNMCO sample will be described. Regarding the modified composition of the C-LMO-LNMCO sample, the composition of the carbon-based material 2 was examined by organic element analysis. In this example, the content of the carbon (C), hydrogen (H), and nitrogen (N) contained in the sample was examined [wt%], and the composition of the modification was analyzed. Samples of C-LMO-LNMCO before heat treatment, samples of C-LMO-LNMCO (300-3), C-LMO-LNMCO (300-6), and C-LMO-LNMCO (300-12) after heat treatment The results of organic element analysis are shown in Table 3.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　表３に示すコーティング＋熱処理前のＣ－ＬＭＯ－ＬＮＭＣＯ試料（サンプル）によれば、Ｃの元素含有量が２．７［ｗｔ％］であり、Ｈの元素含有量が０．０［ｗｔ％］であり、Ｎの元素含有量が０．０［ｗｔ％］であった。 According to the C + LMO-LNMCO sample (sample) before coating + heat treatment shown in Table 3, the element content of C is 2.7 [wt%] and the element content of H is 0.0 [wt%]. The element content of N was 0.0 [wt%].
　コーティング＋熱処理後のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－３）試料によれば、Ｃの元素含有量が２．６［ｗｔ％］であり、Ｈの元素含有量が０．８［ｗｔ％］であり、Ｎの元素含有量が０．０［ｗｔ％］であった。コーティング＋熱処理後のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－６）試料によれば、Ｃの元素含有量が２．２［ｗｔ％］であり、Ｈの元素含有量が０．８［ｗｔ％］であり、Ｎの元素含有量が０．０［ｗｔ％］であった。 According to the C + LMO-LNMCO (300-3) sample after coating and heat treatment, the element content of C is 2.6 [wt%] and the element content of H is 0.8 [wt%]. Yes, the elemental content of N was 0.0 [wt%]. According to the C + LMO-LNMCO (300-6) sample after coating and heat treatment, the element content of C is 2.2 [wt%] and the element content of H is 0.8 [wt%]. Yes, the elemental content of N was 0.0 [wt%].
　コーティング＋熱処理後のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－１２）試料によれば、Ｃの元素含有量が２．４［ｗｔ％］であり、Ｈの元素含有量が０．８［ｗｔ％］であり、Ｎの元素含有量が０．０［ｗｔ％］であった。有機元素分析より、Ｃ－ＬＭＯ－ＬＮＭＣＯ及びＣ－ＬＭＯ－ＬＮＭＣＯ（３００－Ｙ）の試料では、未修飾ＬＭＯ－ＬＮＭＣＯ中には存在しないＣやＨ元素が確認され、カーボン系物質２が生成していることがわかった。 According to the C + LMO-LNMCO (300-12) sample after coating and heat treatment, the element content of C is 2.4 [wt%] and the element content of H is 0.8 [wt%]. Yes, the elemental content of N was 0.0 [wt%]. From the organic element analysis, C-LMO-LNMCO and C-LMO-LNMCO (300-Y) samples confirmed C and H elements not present in the unmodified LMO-LNMCO, and carbon-based material 2 was produced. I found out.
　次に、ＥＤＸ分析（ケイ光Ｘ線分析方法）により、Ｍｎ，Ｃｏ，ＮｉとＣｌとの含有量［ｗｔ％］を調べて修飾組成を分析した。熱処理前のＣ－ＬＭＯ－ＬＮＭＣＯ試料、熱処理後のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－３）、Ｃ－ＬＭＯ－ＬＮＭＣＯ（３００－６）及び、Ｃ－ＬＭＯ－ＬＮＭＣＯ（３００－１２）のＥＤＸ分析結果を表４に示した。 Next, the modified composition was analyzed by examining the content [wt%] of Mn, Co, Ni and Cl by EDX analysis (fluorescence X-ray analysis method). EDX analysis results of C-LMO-LNMCO sample before heat treatment, C-LMO-LNMCO (300-3), C-LMO-LNMCO (300-6), and C-LMO-LNMCO (300-12) after heat treatment Are shown in Table 4.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　表４に示すコーティング＋熱処理前のＣ－ＬＭＯ－ＬＮＭＣＯ試料（サンプル）によれば、Ｍｎの含有量が３９．５５［ｗｔ％］であり、Ｃｏの含有量が１１．７６［ｗｔ％］であり、Ｎｉの含有量が１１．９２［ｗｔ％］であり、Ｃｌの含有量が３２．９５［ｗｔ％］であった。 According to the C + LMO-LNMCO sample (sample) before coating + heat treatment shown in Table 4, the Mn content was 39.55 [wt%] and the Co content was 11.76 [wt%]. Yes, the Ni content was 11.92 [wt%], and the Cl content was 32.95 [wt%].
　コーティング＋熱処理後のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－３）試料によれば、Ｍｎの含有量が４０．３３［ｗｔ％］であり、Ｃｏの含有量が１２．６１［ｗｔ％］であり、Ｎｉの含有量が１５．７２［ｗｔ％］であり、Ｃｌの含有量が２９．２９［ｗｔ％］であった。コーティング＋熱処理後のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－６）試料によれば、Ｍｎの含有量が４８．６１［ｗｔ％］であり、Ｃｏの含有量が１５．６７［ｗｔ％］であり、Ｎｉの含有量が１５．７２［ｗｔ％］であり、Ｃｌの含有量が１９．６２［ｗｔ％］であった。 According to the C + LMO-LNMCO (300-3) sample after coating + heat treatment, the Mn content is 40.33 [wt%], the Co content is 12.61 [wt%] The Ni content was 15.72 [wt%], and the Cl content was 29.29 [wt%]. According to the C + LMO-LNMCO (300-6) sample after coating + heat treatment, the Mn content is 48.61 [wt%], the Co content is 15.67 [wt%], The Ni content was 15.72 [wt%], and the Cl content was 19.62 [wt%].
　コーティング＋熱処理後のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－１２）試料によれば、Ｍｎの含有量が５０．２１［ｗｔ％］であり、Ｃｏの含有量が１６．２１［ｗｔ％］であり、Ｎｉの含有量が１６．２２［ｗｔ％］であり、Ｃｌの含有量が１４．３３［ｗｔ％］であった。上述のＥＤＸ分析より、Ｃ－ＬＭＯ－ＬＮＭＣＯ及びＣ－ＬＭＯ－ＬＮＭＣＯ（３００－Ｙ）の試料では、未修飾のＬＭＯ－ＬＮＭＣＯ中には存在しないＣやＨ元素が確認され、カーボン系物質２が生成していることがわかった。また、Ｃｌ元素の存在が確認され、３００［℃］の熱処理時間とともに減少することがわかった。 According to the C + LMO-LNMCO (300-12) sample after coating + heat treatment, the Mn content is 50.21 [wt%], the Co content is 16.21 [wt%], The Ni content was 16.22 [wt%], and the Cl content was 14.33 [wt%]. From the above EDX analysis, C-LMO-LNMCO and C-LMO-LNMCO (300-Y) samples confirmed C and H elements not present in the unmodified LMO-LNMCO, and the carbon-based substance 2 It was found that it was generated. Further, the presence of Cl element was confirmed, and it was found that it decreased with the heat treatment time of 300 [° C.].
　次に、比表面積測定により、ＬＭＯ－ＬＮＭＣＯ系試料の比表面積［ｍ2／ｇ］を調べて当該試料を分析した。熱処理前のＣ－ＬＭＯ－ＬＮＭＣＯ試料、熱処理後のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－３）、Ｃ－ＬＭＯ－ＬＮＭＣＯ（３００－６）及び、Ｃ－ＬＭＯ－ＬＮＭＣＯ（３００－１２）の比表面積測定結果を表５に示している。 Next, the specific surface area [m 2 / g] of the LMO-LNMCO sample was examined by measuring the specific surface area, and the sample was analyzed. Specific surface area measurement of C-LMO-LNMCO sample before heat treatment, C-LMO-LNMCO (300-3), C-LMO-LNMCO (300-6) and C-LMO-LNMCO (300-12) after heat treatment The results are shown in Table 5.
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
　表５に示すコーティング未処理のＬＮＭＣＯ試料（サンプル）によれば、比表面積が８．８７［ｍ2／ｇ］であった。 According to the untreated LNMCO sample (sample) shown in Table 5, the specific surface area was 8.87 [m 2 / g].
　コーティング＋熱処理前のＣ－ＬＭＯ－ＬＮＭＣＯ試料によれば、比表面積が１５．０３［ｍ2／ｇ］であった。コーティング＋熱処理後のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－３）試料によれば、比表面積が１５．２３［ｍ2／ｇ］であり、コーティング＋熱処理後のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－６）試料によれば、比表面積が１５．０４［ｍ2／ｇ］であり、コーティング＋熱処理後のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－１２）試料によれば、比表面積が１５．１８［ｍ2／ｇ］であった。 According to the C-LMO-LNMCO sample before coating + heat treatment, the specific surface area was 15.03 [m 2 / g]. According to the C + LMO-LNMCO (300-3) sample after coating and heat treatment, the specific surface area was 15.23 [m 2 / g], and C-LMO-LNMCO (300-6) after coating and heat treatment According to the sample, the specific surface area is 15.04 [m 2 / g], and according to the C + LMO-LNMCO (300-12) sample after coating + heat treatment, the specific surface area is 15.18 [m 2 / g]. g].
　上述の比表面積測定結果から、コーティング処理により、比表面積が増加することがわかった。一般にカーボン系物質２は細孔を多く有することより、カーボン系物質が共存することにより比表面積が増加する結果となった。 From the above specific surface area measurement results, it was found that the specific surface area was increased by the coating treatment. In general, since the carbon-based material 2 has many pores, the specific surface area is increased by the coexistence of the carbon-based material.
　続いて、図２５を参照して、正極材料を用いた正極１２の電気化学測定について説明する。この例では、Ｌｉ2ＭｎＯ3系活物質を超音波カーボンコーティング＋熱処理したＣ－ＬＭＯ－ＬＮＭＣＯ（３００－Ｙ）試料を用いて正極材料１２を形成する場合を例に挙げる。図２５に示す三極式セル２０は、図１６に示した負極１１に代えて正極１２の電気化学測定をするものである。同じ符号及び同じ名称のものは同じ機能を有するのでその説明を省略する。 Then, with reference to FIG. 25, the electrochemical measurement of the positive electrode 12 using a positive electrode material is demonstrated. In this example, a case where the positive electrode material 12 is formed using a C—LMO-LNMCO (300-Y) sample obtained by subjecting a Li 2 MnO 3 based active material to ultrasonic carbon coating and heat treatment will be described as an example. A tripolar cell 20 shown in FIG. 25 performs electrochemical measurement of the positive electrode 12 instead of the negative electrode 11 shown in FIG. Since the same reference numerals and the same names have the same functions, the description thereof is omitted.
　正極１２（作用電極（Working electrode））、対極２５（Counter　electrode）、参照極２６（Reference electrode）は、所定のリード線を介して充・放電測定装置２１に接続された。正極１２には、Ｌｉ2ＭｎＯ3系活物質を超音波カーボンコーティング＋熱処理したＣ－ＬＭＯ－ＬＮＭＣＯ（３００－Ｙ）試料を使用する場合を例に挙げた。対極２５及び参照極２６には、金属ＬｉをＮｉメッシュに圧着したもの（Ｌｉon　Ｎｉ　mesh）を用いた。正極材料１２、対極２５及び参照極２６は電解液２４内に浸された。 The positive electrode 12 (Working electrode), the counter electrode 25 (Counter electrode), and the reference electrode 26 (Reference electrode) were connected to the charge / discharge measuring device 21 via a predetermined lead wire. For the positive electrode 12, a case where a C—LMO-LNMCO (300-Y) sample obtained by subjecting a Li 2 MnO 3 based active material to ultrasonic carbon coating and heat treatment was used as an example. As the counter electrode 25 and the reference electrode 26, metal Li bonded to Ni mesh (Lion Ni mesh) was used. The positive electrode material 12, the counter electrode 25, and the reference electrode 26 were immersed in the electrolytic solution 24.
　電解液２４は、１Ｍ　ＬｉＰＦ6／［ＥＣ：ＤＭＣ（１：１）］を用いた。エチレンカーボネート（ＥＣ）とジメメチルカーボネート（ＤＭＣ）の重量比は５０：５０とした。正極１２を構成するＣ－ＬＭＯ－ＬＮＭＣＯ（３００－Ｙ）試料の測定電圧範囲は、４．５［Ｖ］～２．０［Ｖ］（vsＬｉ／Ｌｉ＋）とした。 As the electrolytic solution 24, 1M LiPF 6 / [EC: DMC (1: 1)] was used. The weight ratio of ethylene carbonate (EC) to dimethyl methyl carbonate (DMC) was 50:50. The measurement voltage range of the C-LMO-LNMCO (300-Y) sample constituting the positive electrode 12 was 4.5 [V] to 2.0 [V] (vsLi / Li + ).
　正極１２は、ＣＣ－ＣＶモードで電気化学測定を行い、活性化のため、初回のみ４．７［Ｖ］まで充電処理を行った。ＣＣ－ＣＶモードでは、ＣＣモードで、ある電位まで電流を流した後に、一定電位で保持して充放電しきれていない電気量を流したのちにＣＣモードで測定を続けた。 The positive electrode 12 was subjected to electrochemical measurement in the CC-CV mode, and was charged up to 4.7 [V] only for the first time for activation. In the CC-CV mode, in the CC mode, after a current was passed to a certain potential, the measurement was continued in the CC mode after a quantity of electricity that was held at a constant potential and was not fully charged / discharged was passed.
　この例でも、電解液抵抗をできるだけ小さくするために、参照極２６を可能な限りルギン管２７を介して正極材料１２に近づけた。アルゴン雰囲気で三極式セル２０にて正極１２の電気化学測定を行った。 Also in this example, in order to make the electrolyte resistance as small as possible, the reference electrode 26 was brought as close as possible to the positive electrode material 12 through the Lugin tube 27. Electrochemical measurement of the positive electrode 12 was performed in the triode cell 20 in an argon atmosphere.
　ＬＭＯ－ＬＮＭＣＯ重量基準のＣレートは０．２～５Ｃ（２００［ｍＡｈ／ｇ］換算）であり、電位域は２．０［Ｖ］～４．５［Ｖ］　ｖｓ　Ｌｉ／Ｌｉ+であり、室温（２５℃）の条件の下で、定電流充放電測定を行った。定電流充放電測定によれば、充・放電測定装置２１のガルバノスタットで電流を一定にし、充・放電測定装置２１から三極式セル２０へ一定電流を流し、三極式セル２０の電位とクーロン量の変化を充・放電測定装置２１でモニターする方法を採った。 C rate based on LMO-LNMCO weight is 0.2 to 5C (converted to 200 [mAh / g]), and potential range is 2.0 [V] to 4.5 [V] vs Li / Li + , Constant current charge / discharge measurement was performed under conditions of room temperature (25 ° C.). According to the constant current charge / discharge measurement, the current is made constant by the galvanostat of the charge / discharge measuring device 21, and a constant current is passed from the charge / discharge measuring device 21 to the tripolar cell 20. A method of monitoring the change in coulomb amount with the charge / discharge measuring device 21 was adopted.
　続いて、図２６を参照して、Ｃ－ＬＭＯ－ＬＮＭＣＯ系試料の定電流充放電特性について説明する。この例では、未修飾ＬＭＯ－ＬＮＭＣＯ試料の充放電容量（ＬＭＯ－ＬＮＭＣＯ重量当たりの容量）の充放電サイクルに伴う変化と、ＬＭＯ－ＬＮＭＣＯ＋修飾済みのカーボン系物質２の放電容量（ＬＭＯ－ＬＮＭＣＯ重量当たりの容量）の充放電サイクルに伴う変化とを比較した。試料には図２５に示したＣ－ＬＭＯ－ＬＮＭＣＯ（３００－１２）の正極１２を使用した。 Subsequently, the constant current charge / discharge characteristics of the C-LMO-LNMCO sample will be described with reference to FIG. In this example, the charge / discharge capacity of the unmodified LMO-LNMCO sample (capacity per LMO-LNMCO weight) with the charge / discharge cycle and the discharge capacity of the LMO-LNMCO + modified carbon-based material 2 (LMO-LNMCO weight) (Capacity per unit) was compared with the change accompanying the charge / discharge cycle. As the sample, the positive electrode 12 of C-LMO-LNMCO (300-12) shown in FIG. 25 was used.
　図２６の各図は、各Ｃレート（１Ｃ＝２００［ｍＡ／ｇ］）での各試料の充放電曲線を示している。図２６の各図において、縦軸は電位（Potential／［Ｖ vs Ｌｉ／Ｌｉ+］であり、横軸は放電容量（Capacity）[ｍＡｈ／ｇ］であり、ＬＭＯ－ＬＮＭＣＯ重量当りの容量である。電位が小さくなるにつれ容量が増えているカーブが放電カーブであり、電位が大きくなるにつれ容量が大きくなるカーブが充電カーブである。正極１２の放電カーブと充電カーブとは、負極１１のＳｉとは逆となる。 Each figure of FIG. 26 has shown the charging / discharging curve of each sample in each C rate (1C = 200 [mA / g]). In each diagram of FIG. 26, the vertical axis represents potential (Potential / [V vs Li / Li + ], and the horizontal axis represents discharge capacity (mAh / g), which is a capacity per LMO-LNMCO weight. The curve in which the capacity increases as the potential decreases is the discharge curve, and the curve in which the capacity increases as the potential increases is the charge curve. Is the opposite.
　図２６の各図に示す充放電特性において、右側のカーブから順に、Ｃレートは０．２，０．５Ｃ，１Ｃ，２Ｃ，５Ｃである。スタート電位に差が出るのは、電圧降下（ＩＲ）による。図２６の右図に示す実施例４９のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－１２）は、図２６の左図に示した比較例１５の未修飾ＬＭＯ－ＬＮＭＣＯに比べて、その充放電曲線が共に右側にシフトしていた。各Ｃレート（電流密度）において、Ｃ－ＬＭＯ－ＬＮＭＣＯ（３００－１２）は、３００［℃］の熱処理により、未修飾ＬＭＯ－ＬＮＭＣＯよりも大幅に放電容量が増加した。 In the charge / discharge characteristics shown in each figure of FIG. 26, the C rates are 0.2, 0.5C, 1C, 2C, and 5C in order from the curve on the right side. The difference in the start potential is due to the voltage drop (IR). The C-LMO-LNMCO (300-12) of Example 49 shown on the right side of FIG. 26 has both charge and discharge curves compared to the unmodified LMO-LNMCO of Comparative Example 15 shown on the left side of FIG. Shifted to the right. At each C rate (current density), the discharge capacity of C-LMO-LNMCO (300-12) was significantly increased as compared with unmodified LMO-LNMCO by heat treatment at 300 [° C.].
　放電開始における電圧降下（ＩＲドロップ）は、Ｃ－ＬＭＯ－ＬＮＭＣＯ系試料において高いＣレートでの値は小さく、分極が抑制されていることを示している。すなわち、本発明に係る超音波カーボンコーティング方法によるカーボン系物質２の表面修飾は、導電性の向上等による容量増大に有効であると言える。なお、分極が起きると、電極反応が追いつかなくなる。また、図２７に示すレート特性でも述べるように、高レートでの容量低下が小さい。 The voltage drop (IR drop) at the start of discharge has a small value at a high C rate in the C-LMO-LNMCO sample, indicating that polarization is suppressed. That is, it can be said that the surface modification of the carbon-based material 2 by the ultrasonic carbon coating method according to the present invention is effective for increasing the capacity by improving the conductivity. When polarization occurs, the electrode reaction cannot catch up. Further, as described in the rate characteristics shown in FIG. 27, the capacity drop at a high rate is small.
　続いて、図２７を参照して、ＬＭＯ－ＬＮＭＣＯ系試料のレート特性について説明する。図２７に示す比較例１６は未処理のＬＭＯ－ＬＮＭＣＯ試料、実施例５０は熱処理前のＣ－ＬＭＯ－ＬＮＭＣＯ試料、実施例５１は熱処理後のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－１２）試料の各々のレート特性を示している。図２７において、縦軸はＬＭＯ－ＬＮＭＣＯ重量当りの放電容量（Capacity）[ｍＡｈ／ｇ］であり、横軸は電流密度（Current　density）［ｍＡ／ｇ］である。電流密度は、１Ｃ＝２００［ｍＡ／ｇ］として図２６のＣレートから換算したものである。図２７に示す丸印の比較例１６は、電極材料が未処理のＬＭＯ－ＬＮＭＣＯ試料のレート特性である。このレート特性によれば、ＬＭＯ－ＬＮＭＣＯ試料は電流密度と共に放電容量が低下した。すなわち、電流密度４０［ｍＡ／ｇ］の条件では２１５［ｍＡｈ／ｇ］と放電容量が高いが、電流密度４００［ｍＡ／ｇ］で１００［ｍＡｈ／ｇ］と急激に放電容量が低くなった。電流密度１０００［ｍＡ／ｇ］では５０［ｍＡｈ／ｇ］程度まで放電容量が低くなった。 Subsequently, the rate characteristics of the LMO-LNMCO sample will be described with reference to FIG. 27 is an untreated LMO-LNMCO sample, Example 50 is a C-LMO-LNMCO sample before heat treatment, and Example 51 is a C-LMO-LNMCO (300-12) sample after heat treatment. The rate characteristics are shown. In FIG. 27, the vertical axis represents the discharge capacity (Capacity) [mAh / g] per LMO-LNMCO weight, and the horizontal axis represents the current density [mA / g]. The current density is converted from the C rate in FIG. 26 with 1C = 200 [mA / g]. A comparative example 16 indicated by a circle in FIG. 27 is a rate characteristic of the LMO-LNMCO sample in which the electrode material is not processed. According to this rate characteristic, the discharge capacity of the LMO-LNMCO sample decreased with the current density. That is, the discharge capacity was as high as 215 [mAh / g] under the condition of a current density of 40 [mA / g], but the discharge capacity rapidly decreased to 100 [mAh / g] at a current density of 400 [mA / g]. . At a current density of 1000 [mA / g], the discharge capacity decreased to about 50 [mAh / g].
　これに対して、四角印の実施例５０は、正極材料１２が熱処理前のＣ－ＬＭＯ－ＬＮＭＣＯ試料で、コーティング処理後した試料のレート特性である。電流密度４０［ｍＡ／ｇ］で２５０［ｍＡｈ／ｇ］と未処理のＬＭＯ－ＬＮＭＣＯ試料（比較例１５）より放電容量が高く、より高い電流密度においても未処理のＬＭＯ－ＬＮＭＣＯ試料（比較例１５）より高い放電容量を示した。 On the other hand, Example 50 indicated by the square marks shows the rate characteristics of the sample obtained by coating the positive electrode material 12 with the C-LMO-LNMCO sample before the heat treatment. The discharge capacity is higher than that of the untreated LMO-LNMCO sample (Comparative Example 15) at 250 [mAh / g] at a current density of 40 [mA / g], and the untreated LMO-LNMCO sample (Comparative Example) even at a higher current density. 15) Higher discharge capacity was shown.
　また、三角印の実施例５１は、正極材料１２が熱処理後のＣ－ＬＭＯ－ＬＮＭＣＯ（３００－１２）試料で、コーティング＋熱処理後の試料のレート特性である。コーティング＋熱処理後は初期容量も高いし、レート特性も向上した。すなわち、コーティング＋熱処理後のレート特性によれば、電流密度４０［ｍＡ／ｇ］で２５０［ｍＡｈ／ｇ］と放電容量が高く、電流密度４００［ｍＡ／ｇ］で１５０［ｍＡｈ／ｇ］程度と比較例１５に比べて放電容量が大幅に改善した。電流密度１０００［ｍＡ／ｇ］でも１２５［ｍＡｈ／ｇ］程度と比較例１５に比べて大幅に放電容量が改善した。 Also, Example 51 indicated by triangles shows the rate characteristics of the sample after the coating and heat treatment in which the positive electrode material 12 is a C-LMO-LNMCO (300-12) sample after heat treatment. After coating and heat treatment, the initial capacity was high and the rate characteristics were improved. That is, according to the rate characteristics after coating and heat treatment, the discharge capacity is as high as 250 [mAh / g] at a current density of 40 [mA / g] and about 150 [mAh / g] at a current density of 400 [mA / g]. Compared with Comparative Example 15, the discharge capacity was greatly improved. Even at a current density of 1000 [mA / g], the discharge capacity was significantly improved as compared with Comparative Example 15 at about 125 [mAh / g].
　Ｃ－ＬＭＯ－ＬＮＭＣＯ系試料においても、各レート特性において、ＬＭＯ－ＬＮＭＣＯ系試料よりも高い放電容量が観測され、超音波カーボンコーティング方法の有効性が確認された。さらに熱処理されたＣ－ＬＭＯ－ＬＮＭＣＯ（３００－１２）試料は、３００［℃］熱処理により、さらなる導電性の向上等の理由により、高レートでの放電容量が増加し、より優れたレート特性が得られることが明確になった。 Also in the C-LMO-LNMCO sample, a higher discharge capacity was observed in each rate characteristic than in the LMO-LNMCO sample, confirming the effectiveness of the ultrasonic carbon coating method. Further, the heat-treated C-LMO-LNMCO (300-12) sample has an increased discharge capacity at a high rate due to a further improvement in conductivity, etc. due to the heat treatment at 300 [° C.], resulting in better rate characteristics. It became clear that it was obtained.
　このように第３の実施形態に係る正極用の電極材料によれば、活物質１としてのＬＭＯ－ＬＮＭＣＯ粒子の全表面あるいはその一部表面にカーボン系物質２が覆われ、このカーボン系物質２は、超音波周波数＝４０ｋＨｚ及び超音波出力２００～３００［Ｗ］の超音波が照射時間９［ｈ］、ｏ－ＤＣＢ３に照射され、当該ｏ－ＤＣＢ３のラジカル反応により生成されたものである。 As described above, according to the electrode material for a positive electrode according to the third embodiment, the carbon-based material 2 is covered on the entire surface or a part of the surface of the LMO-LNMCO particles as the active material 1. Is generated by the radical reaction of o-DCB3 by irradiating the o-DCB3 with ultrasonic waves having an ultrasonic frequency of 40 kHz and an ultrasonic output of 200 to 300 [W] for an irradiation time of 9 [h].
　この構成によって、ＬＭＯ－ＬＮＭＣＯ粒子の結晶の隅々までカーボン系材料２が浸入（被着）することにより、当該ＬＭＯ－ＬＮＭＣＯ粒子の結晶構造が合金化や脱合金化反応から保護され、かつ、導電性に優れた正極用の電極材料を提供できるようになった。 With this configuration, the carbon-based material 2 penetrates (deposits) into every corner of the crystal of the LMO-LNMCO particles, so that the crystal structure of the LMO-LNMCO particles is protected from alloying and dealloying reactions, and An electrode material for a positive electrode having excellent conductivity can be provided.
　また、正極材料の製造方法によれば、強力な超音波照射により有機溶媒中にＬＭＯ－ＬＮＭＣＯ粒子を分散させるとともに有機溶媒分子を重合・カーボン化させることにより、Ｃ－ＬＭＯ－ＬＮＭＣＯ系の複合体の合成ができた。すなわち、ＬＭＯ－ＬＮＭＣＯ粒子の表面にナノメートルオーダーの厚みのカーボンの形成ができるようになった（ＬＭＯ－ＬＮＭＣＯ／カーボン）。カーボン性物質２による表面修飾に用いられる有機溶媒はジクロロベンゼンに限定されることはなく、他の芳香族系化合物でもよい。 In addition, according to the method for producing a positive electrode material, a C-LMO-LNMCO composite is obtained by dispersing LMO-LNMCO particles in an organic solvent by strong ultrasonic irradiation and polymerizing / carbonizing the organic solvent molecules. Has been synthesized. That is, carbon having a thickness of nanometer order can be formed on the surface of LMO-LNMCO particles (LMO-LNMCO / carbon). The organic solvent used for the surface modification with the carbonaceous material 2 is not limited to dichlorobenzene, and may be other aromatic compounds.
　しかも、カーボン系物質２による表面修飾方法は、非重合性の有機溶媒（ジクロロベンゼン）にＬＭＯ－ＬＮＭＣＯ粒子を加え、超音波を照射するだけの簡単な方法であって、簡便かつ大量生産にも利用できる方法である。また、超音波出力や、超音波照射時間、活物質１の濃度等に依存して、カーボン生成量を変化させることができる。 Moreover, the surface modification method using the carbon-based material 2 is a simple method in which LMO-LNMCO particles are added to a non-polymerizable organic solvent (dichlorobenzene) and irradiated with ultrasonic waves. It is an available method. In addition, the amount of carbon produced can be changed depending on the ultrasonic output, the ultrasonic irradiation time, the concentration of the active material 1, and the like.
　カーボン系物質２による表面修飾方法は、電池の活物質１の表面ナノコーティング方法として実用的にもインパクトの高い技術である。循環装置等の流通式装置でカーボン修飾行うことにより、正極材料１２を大量に生産できる。 The surface modification method using the carbon-based material 2 is a technology that has a high impact in practice as a surface nano-coating method for the active material 1 of the battery. By performing the carbon modification with a circulation type device such as a circulation device, the positive electrode material 12 can be produced in large quantities.
　また、活物質１の表面ナノコーティングにより導電性の付与とともに、充放電サイクル特性の安定性向上が図れる。本発明に係るカーボン系物質２の表面修飾方法は、正極材料の充放電特性の向上に効果があることを確認した。正極活物質の表面ナノコーティングにより、より高容量を示すと共に、レート特性が向上する。これにより、カーボン系物質２で隅々まで覆われ保護されたＬＭＯ－ＬＮＭＣＯ粒子の正極を備えたＬｉイオン二次電池の高容量化及び、高容量のＬｉイオン二次電池の製造に大きく寄与する。 Moreover, the surface nano-coating of the active material 1 can provide conductivity and improve the stability of charge / discharge cycle characteristics. It was confirmed that the surface modification method for the carbon-based material 2 according to the present invention is effective in improving the charge / discharge characteristics of the positive electrode material. The surface nano-coating of the positive electrode active material exhibits higher capacity and improves rate characteristics. This greatly contributes to increasing the capacity of a Li-ion secondary battery equipped with a positive electrode of LMO-LNMCO particles covered and protected by the carbon-based material 2 and manufacturing a high-capacity Li-ion secondary battery. .
　＜第４の実施形態＞
 ［リチウムイオン二次電池］
　続いて、図２８を参照して、第４の実施形態としてのリチウムイオン二次電池４０の構成例について説明する。図２８に示すリチウム（以下Ｌｉという）イオン二次電池４０は、負極材料４１、正極材料４２、負極集電体４３、正極集電体４４、セパレータ４５、電解質部材４６、本体収容部材４７、負極端子４８及び正極端子４９を有して構成される（一部切り欠き部を含む）。 <Fourth Embodiment>
[Lithium ion secondary battery]
Subsequently, a configuration example of the lithium ion secondary battery 40 as the fourth embodiment will be described with reference to FIG. 28 includes a negative electrode material 41, a positive electrode material 42, a negative electrode current collector 43, a positive electrode current collector 44, a separator 45, an electrolyte member 46, a main body housing member 47, a negative electrode. A terminal 48 and a positive electrode terminal 49 are included (partially cut out).
　Ｌｉイオン二次電池４０の負極は負極材料４１、負極集電体４３及び負極端子４８を有する。負極は、表面をカーボン系物質２により覆った負極活物質が負極集電体４３上に設けられている。負極材料４１には、例えば、第１及び第２の実施形態で説明し負極用の電極材料１０が使用される。負極活物質の全表面あるいはその一部表面を覆うカーボン性物質２は、超音波が、周波数＝４０ｋＨｚ、出力２００～３００［Ｗ］、及び照射時間３［ｈ］～９［ｈ］の条件で、ｏ－ＤＣＢ３に照射され、当該ｏ－ＤＣＢ３のラジカル反応により生成されたものである。 The negative electrode of the Li ion secondary battery 40 has a negative electrode material 41, a negative electrode current collector 43, and a negative electrode terminal 48. In the negative electrode, a negative electrode active material whose surface is covered with the carbon-based material 2 is provided on the negative electrode current collector 43. As the negative electrode material 41, for example, the electrode material 10 for negative electrode described in the first and second embodiments is used. The carbonaceous material 2 covering the entire surface of the negative electrode active material or a part of the surface thereof has ultrasonic waves under the conditions of frequency = 40 kHz, output 200 to 300 [W], and irradiation time 3 [h] to 9 [h]. , O-DCB3 is irradiated and generated by radical reaction of the o-DCB3.
　負極集電体４３上に負極材料４１を形成するにあたっては、超音波カーボンコーティング＋熱処理後のＳｉナノ粒子４等の負極活物質と、アセチレンブラック等の導電剤と、ＰＶｄｆ等の結着剤とを適当な溶剤でスラリー状にしたものを負極集電体４３に塗布し、それを乾燥する。負極集電体４３は、厚み数十μｍ程度の銅箔等（帯状電極）が用いられる（図１５参照）。負極集電体４３には銅箔の他にＮｉ（ニッケル）やＳＵＳ（ステンレス）等の箔板を使用してもよい。負極集電体４３には負極端子４８が接続される。 In forming the negative electrode material 41 on the negative electrode current collector 43, a negative electrode active material such as Si nanoparticle 4 after ultrasonic carbon coating and heat treatment, a conductive agent such as acetylene black, a binder such as PVdf, Is applied to the negative electrode current collector 43 and dried. For the negative electrode current collector 43, a copper foil or the like (band electrode) having a thickness of about several tens of μm is used (see FIG. 15). For the negative electrode current collector 43, a foil plate such as Ni (nickel) or SUS (stainless steel) may be used in addition to the copper foil. A negative electrode terminal 48 is connected to the negative electrode current collector 43.
　Ｌｉイオン二次電池４０の正極は正極材料４２、正極集電体４４及び正極端子４９を有する。正極は、リチウムを含む正極活物質を有する正極材料４２を正極集電体４４上に設けることにより構成されている。正極材料４２には、例えば、第３の実施形態で説明した正極用の電極材料１０が使用される。正極活物質の全表面あるいはその一部表面を覆うカーボン系物質２は、超音波が、周波数＝４０ｋＨｚ、出力３００［Ｗ］、及び照射時間９［ｈ］の条件で、ｏ－ＤＣＢ３に照射され、当該ｏ－ＤＣＢ３のラジカル反応により生成されたものである。 The positive electrode of the Li ion secondary battery 40 has a positive electrode material 42, a positive electrode current collector 44, and a positive electrode terminal 49. The positive electrode is configured by providing a positive electrode material 42 having a positive electrode active material containing lithium on a positive electrode current collector 44. For example, the positive electrode material 10 described in the third embodiment is used as the positive electrode material 42. The carbon-based material 2 covering the entire surface or a part of the surface of the positive electrode active material is irradiated with o-DCB 3 under the conditions of the frequency = 40 kHz, the output 300 [W], and the irradiation time 9 [h]. , And produced by the radical reaction of o-DCB3.
　正極集電体４４上に正極材料４２を形成するに当たっては、超音波カーボンコーティング＋熱処理後のＣ－ＬＭＯ－ＬＮＭＣＯ系の複合体等の正極活物質と、アセチレンブラック等の導電剤と、ＰＶｄｆ等の結着剤とを適当な溶剤でスラリー状にしたものを正極集電体４４に塗布し、それを乾燥する。正極集電体４４は、厚み数十μｍ程度のアルミ箔（帯状電極）が用いられ、正極集電体４４には正極端子４９が接続される。 In forming the positive electrode material 42 on the positive electrode current collector 44, a positive electrode active material such as a C-LMO-LNMCO composite after ultrasonic carbon coating and heat treatment, a conductive agent such as acetylene black, PVdf, etc. A positive electrode current collector 44 is applied to a positive electrode current collector 44 which is made into a slurry with an appropriate solvent and dried. The positive electrode current collector 44 is made of an aluminum foil (band electrode) having a thickness of about several tens of μm, and a positive electrode terminal 49 is connected to the positive electrode current collector 44.
　もちろん、負極材料４１と組み合わされる正極材料４２は、第３の実施形態で説明した正極材料１２に限られることはない。正極集電体４４（帯状電極）上に正極材料４２を形成するにあたっては、ＬｉＣｏＯ2等の活物質と、アセチレンブラック等の導電剤と、ＰＶｄｆ等の結着剤とを適当な溶剤でスラリー状にしたものをアルミ箔等に塗布し、それを乾燥してもよい。 Of course, the positive electrode material 42 combined with the negative electrode material 41 is not limited to the positive electrode material 12 described in the third embodiment. In forming the positive electrode material 42 on the positive electrode current collector 44 (band electrode), an active material such as LiCoO 2 , a conductive agent such as acetylene black, and a binder such as PVdf are slurried in an appropriate solvent. You may apply what was made to aluminum foil etc., and may dry it.
　その際の正極活物質には、例えば、Ｌｉを含む複合金属酸化物、Ｌｉを含む金属リン酸塩や金属ケイ酸塩などのポリアニオン系物質、Ｌｉを含む金属硫化物、Ｌｉを含む有機高分子物質などが用いられる。 The positive electrode active material at that time includes, for example, a composite metal oxide containing Li, a polyanionic material such as a metal phosphate or metal silicate containing Li, a metal sulfide containing Li, or an organic polymer containing Li Substances are used.
　もちろん、正極材料４２と組み合わされる負極材料４１は、第１及び第２の実施形態で説明した負極用の電極材料１０に限られることはない。負極材料４１に用いられる負極活物質は、Ｓｉナノ粒子４の他に、例えば、Ｓｉの粒子や薄膜、Ｓｎなどの合金系物質の粒子や薄膜、ＳｉＯｘ（０＜ｘ＜２）などの酸化物、リチウム金属、グラファイトやカーボン系物質、ＮｂやＦｅやＴｉなどの金属酸化物、金属窒化物、金属硫化物、有機高分子物質などを用いてもよい。 Of course, the negative electrode material 41 combined with the positive electrode material 42 is not limited to the negative electrode material 10 described in the first and second embodiments. The negative electrode active material used for the negative electrode material 41 includes, for example, Si particles and thin films, particles and thin films of alloy materials such as Sn, and oxides such as SiOx (0 <x <2) in addition to the Si nanoparticles 4. Lithium metal, graphite, carbon-based materials, metal oxides such as Nb, Fe, and Ti, metal nitrides, metal sulfides, and organic polymer materials may also be used.
　また、負極活物質は、リチウムイオンを吸蔵・放出可能であってリチウムと合金化反応可能な元素又は／及びリチウムと合金化反応可能な元素化合物からなるとよい。リチウムと合金化反応可能な元素にはＮａ、Ｋ、Ｒｂ、Ｃｓ、Ｆｒ、Ｂｅ、Ｍｇ、Ｃａ、Ｓｒ、Ｂａ、Ｒａ、Ｔｉ、Ａｇ、Ｚｎ、Ｃｄ、Ａｌ、Ｇａ、Ｉｎ、Ｓｉ、Ｇｅ、Ｓｎ、Ｐｂ、Ｓｂ、Ｂｉが挙げられる。 Further, the negative electrode active material may be composed of an element capable of occluding and releasing lithium ions and capable of being alloyed with lithium or / and an element compound capable of being alloyed with lithium. Elements capable of alloying with lithium include Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Ti, Ag, Zn, Cd, Al, Ga, In, Si, Ge, Sn, Pb, Sb, Bi are mentioned.
　本体収容部材４７には、負極材料４１と正極材料４２とが対峙するように配置される。正極と負極との間には電解質４６が設けられる。電解質４６のほぼ中央にはセパレータ４５が設けられる。セパレータ４５（多孔性隔膜）には、ポリエチレン（ＰＥ）や、ポリプロピレン（ＰＰ）を微多孔質状に形成したものが使用される。 The main body housing member 47 is arranged so that the negative electrode material 41 and the positive electrode material 42 face each other. An electrolyte 46 is provided between the positive electrode and the negative electrode. A separator 45 is provided at substantially the center of the electrolyte 46. As the separator 45 (porous membrane), polyethylene (PE) or polypropylene (PP) formed in a microporous shape is used.
　電解質４６には図１６で説明した電解液の他に、鎖状カーボネート又はエーテル系化合物（非プロトン性有機溶媒）との混合溶媒に、イオン半径の大きいアニオンから成るリチウム塩や、ＬｉＣｌＯ4、ＬｉＰＦ6等を溶解した非水溶液が使用される。電解質４６には、１－エチル－３－メチルイミダゾリウム（ＥＭＩ）などのカチオンと（ＣＦ3ＳＯ2）2Ｎなどのアニオンからなるイオン性液体に、Ｌｉ塩を溶解させたイオン性液体電解質や、有機高分子のゲルあるいは固体に、Ｌｉ塩を溶解させたポリマー電解質、Ｌｉ2Ｏ－ＳｉＯ2やＬｉ2Ｓ－ＳｉＳ2などのＬｉイオン伝導性ガラス、ＮＡＳＩＣＯＮ（Ｎａ3Ｚｒ2Ｓｉ2ＰＯ12）などのセラミックス系固体電解質でもよい。電解質４６は活物質１によって選択すればよい。 In addition to the electrolytic solution described in FIG. 16, the electrolyte 46 includes a mixed solvent with a chain carbonate or an ether compound (aprotic organic solvent), a lithium salt composed of an anion having a large ionic radius, LiClO 4 , LiPF. A non-aqueous solution in which 6 etc. is dissolved is used. The electrolyte 46 includes an ionic liquid electrolyte in which a Li salt is dissolved in an ionic liquid composed of a cation such as 1-ethyl-3-methylimidazolium (EMI) and an anion such as (CF 3 SO 2 ) 2 N. A polymer electrolyte in which a Li salt is dissolved in an organic polymer gel or solid, Li ion conductive glass such as Li 2 O—SiO 2 or Li 2 S—SiS 2 , NASICON (Na 3 Zr 2 Si 2 PO 12 Or other ceramic solid electrolytes. The electrolyte 46 may be selected depending on the active material 1.
　本体収容部材４７は電池缶を構成する。電池缶の形状は、筒形状でも、筺体形状でも、扁平形状でもよい。筒形状の電池缶の場合は、負極材料４１、正極材料４２、負極集電体４３、正極集電体４４、セパレータ４５及び電解質４６から成る本体部材をロール状に形成したものを収納する。筺体形状の電池缶の場合は、上述の本体部材を折り畳み状に形成したものを収納する。 The body housing member 47 constitutes a battery can. The battery can may have a cylindrical shape, a casing shape, or a flat shape. In the case of a cylindrical battery can, a body member formed of a negative electrode material 41, a positive electrode material 42, a negative electrode current collector 43, a positive electrode current collector 44, a separator 45, and an electrolyte 46 is stored. In the case of a case-shaped battery can, the above-mentioned main body member formed in a folded shape is stored.
　負極材料４１や正極材料４２等は、本体収容部材４７内で共用する形態であってもよい。例えば、負極材料４１又は正極材料４２を塗布した共通電極集電体を形成し、これを同極の２つの電極集電体で挟み込んで電池を形成してもよい。もちろん、電解質４６及びセパレータ４５を介在させる。筒形状の電池缶に適している。 The negative electrode material 41, the positive electrode material 42, and the like may be shared within the main body housing member 47. For example, a battery may be formed by forming a common electrode current collector coated with the negative electrode material 41 or the positive electrode material 42 and sandwiching the common electrode current collector between two electrode current collectors of the same polarity. Of course, the electrolyte 46 and the separator 45 are interposed. Suitable for cylindrical battery cans.
　また、１つの電極集電体に対して相互に異なる負極材料４１又は正極材料４２を配置して、シリーズ（直列）に電極を配置して電池を構成するようにしてもよい。筺体形状の電池缶に適していると共に、出力電圧の高い電池が形成できる。 Alternatively, different negative electrode materials 41 or positive electrode materials 42 may be arranged for one electrode current collector, and electrodes may be arranged in series to form a battery. A battery having a high output voltage can be formed while being suitable for a battery-shaped battery can.
　このように、第４の実施形態に係る第１のＬｉイオン二次電池４０によれば、負極材料は、Ｃ－Ｓｉ（Ｘ）ｙ［ｈ］Ｚ［Ｗ］等からなり、Ｓｉナノ粒子４（負極活物質）の全表面あるいはその一部表面がカーボン系物質２により覆われて形成されている。負極材料は、例えば、超音波が、周波数＝４０ｋＨｚ、出力２００～３００［Ｗ］、及び照射時間３［ｈ］～９［ｈ］の条件で、ｏ－ＤＣＢ３に照射され、当該ｏ－ＤＣＢ３のラジカル反応により生成される。 Thus, according to the first Li ion secondary battery 40 according to the fourth embodiment, the negative electrode material is made of C—Si (X) y [h] Z [W] or the like, and the Si nanoparticles 4 The entire surface of the (negative electrode active material) or a part of the surface is covered with the carbon-based material 2. As the negative electrode material, for example, ultrasonic waves are applied to the o-DCB 3 under the conditions of a frequency = 40 kHz, an output of 200 to 300 [W], and an irradiation time of 3 [h] to 9 [h]. Generated by radical reaction.
　Ｓｉナノ粒子４（負極活物質）の表面カーボンナノコーティングにより負極に導電性が付与されると共に、合金系負極活物質の安定化が図られ、充放電サイクルの安定性の向上が図れる。これにより、高容量のＬｉイオン二次電池４０を提供できる。 The surface carbon nano-coating of the Si nanoparticles 4 (negative electrode active material) imparts conductivity to the negative electrode, stabilizes the alloy-based negative electrode active material, and improves the stability of the charge / discharge cycle. Thereby, the high capacity | capacitance Li ion secondary battery 40 can be provided.
　また、第２のＬｉイオン二次電池によれば、正極材料が、Ｃ－ＣＭＯ－ＬＮＭＣＯ系のＣＭＯ－ＬＮＭＣＯ粒子（正極活物質）の全表面あるいはその一部表面がカーボン系物質２により覆われている。カーボン系物質２は、超音波が、周波数＝４０ｋＨｚ、出力３００［Ｗ］及び照射時間９［ｈ］の条件で、ｏ－ＤＣＢ３に照射され、当該ｏ－ＤＣＢ３のラジカル反応により生成されたものである。 Further, according to the second Li ion secondary battery, the positive electrode material is covered with the carbon-based material 2 on the entire surface or a part of the surface of the C-CMO-LNMCO-based CMO-LNMCO particles (positive electrode active material). ing. The carbon-based material 2 is generated by the radical reaction of the o-DCB3 by irradiating the o-DCB3 with ultrasonic waves under the conditions of frequency = 40 kHz, output 300 [W] and irradiation time 9 [h]. is there.
　ＣＭＯ－ＬＮＭＣＯ粒子（正極活物質）の表面カーボンナノコーティングにより正極に導電性が付与されると共に、正極活物質の安定化が図られ、充放電サイクルの安定性の向上が図れる。これにより、高容量のＬｉイオン二次電池４０を提供できる。 The surface carbon nanocoating of CMO-LNMCO particles (positive electrode active material) imparts conductivity to the positive electrode, stabilizes the positive electrode active material, and improves the stability of the charge / discharge cycle. Thereby, the high capacity | capacitance Li ion secondary battery 40 can be provided.
　更に、第３のＬｉイオン二次電池は、負極と、正極と負極との間に設けられた電解質４６とを備えている。正極材料は、リチウムを含むＣ－ＣＭＯ－ＬＮＭＣＯ系のＣＭＯ－ＬＮＭＣＯ粒子（正極活物質）の全表面あるいはその一部表面がカーボン系物質２により覆われて形成されている。正極は、正極材料が正極集電体４４上に設けられている。負極材料は、全表面あるいはその一部表面がカーボン性物質２により覆われたＳｉナノ粒子４から成る。負極は、負極材料が負極集電体４３上に設けられてなる。正極材料及び負極材料のいずれの場合でも、カーボン系物質２は、超音波が、周波数＝４０ｋＨｚ、出力２００～３００［Ｗ］、及び照射時間３［ｈ］～９［ｈ］の条件で、ｏ－ＤＣＢ３に照射され、当該ｏ－ＤＣＢ３のラジカル反応により生成されたものである。 Furthermore, the third Li ion secondary battery includes a negative electrode and an electrolyte 46 provided between the positive electrode and the negative electrode. The positive electrode material is formed by covering the entire surface or a part of the surface of C-CMO-LNMCO-based CMO-LNMCO particles (positive electrode active material) containing lithium with the carbon-based material 2. In the positive electrode, the positive electrode material is provided on the positive electrode current collector 44. The negative electrode material is composed of Si nanoparticles 4 whose entire surface or a part of the surface thereof is covered with the carbonaceous material 2. The negative electrode is formed by providing a negative electrode material on the negative electrode current collector 43. In both cases of the positive electrode material and the negative electrode material, the carbon-based substance 2 is obtained under the condition that the ultrasonic wave has a frequency = 40 kHz, an output of 200 to 300 [W], and an irradiation time of 3 [h] to 9 [h]. It is generated by the radical reaction of o-DCB3 by irradiation with -DCB3.
　Ｓｉナノ粒子４（負極活物質）及びＣＭＯ－ＬＮＭＣＯ粒子（正極活物質）の各々の表面カーボンナノコーティングにより、負極及び正極に導電性が付与されると共に、合金系負極活物質及び正極活物質の安定化が図られ、充放電サイクルの安定性の向上が図れる。これにより、高容量のＬｉイオン二次電池４０を提供できる。 The surface carbon nano-coating of each of the Si nanoparticles 4 (negative electrode active material) and CMO-LNMCO particles (positive electrode active material) imparts conductivity to the negative electrode and the positive electrode, and the alloy-based negative electrode active material and the positive electrode active material. Stabilization is achieved, and the stability of the charge / discharge cycle can be improved. Thereby, the high capacity | capacitance Li ion secondary battery 40 can be provided.
　ここで、図２９を参照して、超音波照射時間Ｙ［ｈ］の上限値について、ｏ－ジクロロベンゼンのみ（無添加状態）の液体に係る超音波処理例について説明する。ここでは無添加状態とは、ｏ－ジクロロベンゼンに一切の活物質１が加えられていない状態をいう。図２９の左図は、超音波照射時のｏ－ジクロロベンゼンの色の変化と、その紫外可視吸収スペクトルを示す説明図である。図２９の左図において、縦軸は吸光度［arb.unit］であり、横軸は波長［ｎｍ］である。 Here, with reference to FIG. 29, an example of ultrasonic treatment relating to a liquid containing only o-dichlorobenzene (no addition state) as an upper limit value of the ultrasonic irradiation time Y [h] will be described. Here, the additive-free state refers to a state in which no active material 1 is added to o-dichlorobenzene. The left diagram of FIG. 29 is an explanatory diagram showing a change in the color of o-dichlorobenzene and its ultraviolet-visible absorption spectrum during ultrasonic irradiation. In the left diagram of FIG. 29, the vertical axis represents absorbance [arb.unit], and the horizontal axis represents wavelength [nm].
　図中の写真図は、左側から右側へ、無添加状態のｏ－ジクロロベンゼンのみの液体を、２０，９０，１８０，３６０，５４０，１０８０［min］の６種類の照射時間で、超音波の出力３００［Ｗ］、その周波数４０［ｋＨｚ］で、超音波処理した試料の色の時間変化等を示している。超音波処理における試料の色は、超音波の照射時間が経過する程、透明（色）→黄色→黄土色→暗茶色→灰色→黒色等のように変化した（図は白黒表示：グレースケールで白色→灰色→黒色）。紫外可視吸収スペクトルによれば、５００［ｎｍ］等の長波長側で吸光度［arb.unit］が低下し、カーボン系物質２が増加することがわかった。 The photograph in the figure shows the ultrasonic wave of an o-dichlorobenzene-only liquid in the non-added state from the left side to the right side during six irradiation times of 20, 90, 180, 360, 540, and 1080 [min]. A time change of the color of the sample subjected to ultrasonic treatment is shown at an output of 300 [W] and a frequency of 40 [kHz]. The color of the sample in the ultrasonic treatment changed as transparent (color) → yellow → ocher → dark brown → gray → black etc. as the time of ultrasonic irradiation elapsed (black and white display: gray scale) (White → gray → black). According to the ultraviolet-visible absorption spectrum, it was found that the absorbance [arb.unit] decreased and the carbon-based substance 2 increased on the long wavelength side such as 500 [nm].
　図２９の右図は、各波長における吸光度と超音波照射時間との関係例を示すグラフ図である。図２９の右図において、縦軸は吸光度［arb.unit］であり、横軸は超音波照射時間［min］である。試料は、図２９Ａに示した紫外可視吸収スペクトルの長波長側で吸光度［arb.unit］が低下してカーボン系物質２が増加した波長５００［ｎｍ］以上のものを抽出したものである。この例では、波長５００［ｎｍ］，６００［ｎｍ］，７００［ｎｍ］，８００［ｎｍ］の４つの試料を挙げている。この関係グラフから超音波照射時間Ｙの上限値を考察する。 29 is a graph showing an example of the relationship between the absorbance at each wavelength and the ultrasonic irradiation time. In the right diagram of FIG. 29, the vertical axis represents absorbance [arb.unit], and the horizontal axis represents ultrasonic irradiation time [min]. The sample was extracted from the long wavelength side of the UV-visible absorption spectrum shown in FIG. 29A with a wavelength of 500 nm or more in which the absorbance [arb.unit] decreased and the carbon-based material 2 increased. In this example, four samples having wavelengths of 500 [nm], 600 [nm], 700 [nm], and 800 [nm] are listed. The upper limit of the ultrasonic irradiation time Y will be considered from this relationship graph.
　図２９の右図によれば、ｏ－ジクロロベンゼンのみの液体に超音波を照射したとき、重合およびカーボン系物質２の生成に伴う、波長５００［ｎｍ］，６００［ｎｍ］，７００［ｎｍ］，８００［ｎｍ］の４つの試料の長波長側の吸収の時間変化から、超音波照射時間が１６～１８時間程度で、ほぼ飽和することが実験で確かめられた。この長波長側の吸収の時間変化から超音波照射時間の上限値Ｙ＝１６［ｈ］（９６０［min］）を選択したものである。ただし、超音波照射時間の上限値は、芳香族系有機溶媒の種類や照射する超音波の周波数や出力にも依存するので、これに限定されることはない。 According to the right diagram of FIG. 29, when ultrasonic waves are applied to a liquid containing only o-dichlorobenzene, the wavelengths are 500 [nm], 600 [nm], and 700 [nm] associated with the polymerization and the generation of the carbon-based material 2. , 800 [nm], it was confirmed by experiment that the ultrasonic wave irradiation time was about 16 to 18 hours and was almost saturated from the change with time of the absorption on the long wavelength side of the four samples. The upper limit value Y = 16 [h] (960 [min]) of the ultrasonic irradiation time is selected from the change in absorption time on the long wavelength side. However, the upper limit value of the ultrasonic irradiation time depends on the type of the aromatic organic solvent and the frequency and output of the ultrasonic wave to be irradiated, and is not limited to this.
　また、芳香族系有機溶媒に加える活物質１の種類も影響する。例えば、Ｓｎ粒子をｏ－ジクロロベンゼンを分散させたＳｎ系では、より短時間でカーボン系物質２が生成することが実験で確かめられている。このように、超音波の照射条件の範囲や最適条件等は、活物質１や、芳香族系有機溶媒によって変わってくることは言うまでもない。 Also, the type of active material 1 added to the aromatic organic solvent also affects. For example, in an Sn system in which o-dichlorobenzene is dispersed in Sn particles, it has been confirmed by experiments that the carbon-based material 2 is generated in a shorter time. Thus, it goes without saying that the range of ultrasonic irradiation conditions, the optimum conditions, and the like vary depending on the active material 1 and the aromatic organic solvent.
　本発明は、活物質の新規表面コーティング方法、表面コーティングされた活物質を備えた負極材料及び正極材料に適用し、更に、これらの負極材料及び正極材料を備えた二次電池に適用して極めて好適である。 The present invention is applied to a novel surface coating method of an active material, a negative electrode material and a positive electrode material provided with a surface-coated active material, and further applied to a secondary battery including these negative electrode material and positive electrode material. Is preferred.
　１・・・活物質、２・・・カーボン系物質、３・・・ｏ－ＤＣＢ、４・・・Ｓｉナノ粒子、１０・・・電極材料、１１・・・負極材料、１２・・・正極材料、４０・・・Ｌｉイオン二次電池、６１・・・超音波調整装置 DESCRIPTION OF SYMBOLS 1 ... Active material, 2 ... Carbon type material, 3 ... o-DCB, 4 ... Si nanoparticle, 10 ... Electrode material, 11 ... Negative electrode material, 12 ... Positive electrode Material: 40 ... Li-ion secondary battery, 61 ... Ultrasonic adjustment device

Claims (22)

  1. 　活物質と、
    　前記活物質の全表面あるいはその一部表面を覆う炭素系物質とを備え、
    　前記炭素系物質は、前記活物質を加えた芳香族系有機溶媒に加振処理することにより生成されてなることを特徴とする電極材料。     Active material,
    A carbon-based material covering the entire surface of the active material or a partial surface thereof,
    The carbon material is produced by subjecting an aromatic organic solvent to which the active material has been added to vibration treatment.
  2. 　前記活物質は、粒子状をなし、
    　前記炭素系物質は、粒子状の前記活物質の表面に形成されている請求項１記載の電極材料。     The active material is in the form of particles,
    The electrode material according to claim 1, wherein the carbon-based material is formed on a surface of the particulate active material.
  3. 　前記炭素系物質の厚みは、１．０ｎｍ以上５０ｎｍ以下である請求項２記載の電極材料。 The electrode material according to claim 2, wherein the carbon-based material has a thickness of 1.0 nm to 50 nm.
  4. 　前記炭素系物質は、更に、粒子状の前記活物質の間隙に形成されている請求項２又は３記載の電極材料。 The electrode material according to claim 2 or 3, wherein the carbon-based material is further formed in a gap between the particulate active materials.
  5. 　前記炭素系物質は、グラファイトを含む請求項１～４のいずれか１項に記載の電極材料。 The electrode material according to any one of claims 1 to 4, wherein the carbon-based substance includes graphite.
  6. 　前記炭素系物質は、ラマンシフトにおいて、１３６０［ｃｍ-1］付近のピーク（Ｄバンド）に対する１５８０［ｃｍ-1］付近のピーク（Ｇバンド）の相対強度が高い請求項１～５のいずれか１項に記載の電極材料。 The carbon-based material according to any one of claims 1 to 5, wherein a relative intensity of a peak (G band) near 1580 [cm -1 ] to a peak (D band) near 1360 [cm -1 ] is high in Raman shift. 2. The electrode material according to item 1.
  7. 　前記活物質は、リチウムイオンを挿入・脱離し得る負極活物質、又はリチウムイオンを挿入・脱離し得る正極活物質からなる請求項１～６のいずれか１項に記載の電極材料。 7. The electrode material according to claim 1, wherein the active material comprises a negative electrode active material capable of inserting / extracting lithium ions or a positive electrode active material capable of inserting / extracting lithium ions.
  8. 　前記負極活物質は、珪素及び珪素を含む化合物から選択される活物質からなる請求項７に記載の電極材料。 The electrode material according to claim 7, wherein the negative electrode active material is made of an active material selected from silicon and a compound containing silicon.
  9. 　前記負極活物質は、リチウム含有ケイ素酸化物であり、
    　リチウム含有ケイ素酸化物は組成式ＬｉxＳｉＯyで表され、リチウム含有量ｘと酸素量ｙがそれぞれ０≦ｘ、０＜ｙ≦２である請求項８に記載の電極材料。     The negative electrode active material is a lithium-containing silicon oxide,
    9. The electrode material according to claim 8, wherein the lithium-containing silicon oxide is represented by a composition formula LixSiOy, and the lithium content x and the oxygen content y are 0 ≦ x and 0 <y ≦ 2, respectively.
  10. 　前記負極活物質は、Ｌｉ２ＳｉＯ３である請求項９に記載の電極材料。 The electrode material according to claim 9, wherein the negative electrode active material is Li 2 SiO 3 .
  11. 　前記正極活物質は、Ｌｉ2ＭｎＯ3系活物質からなる請求項７～１０のいずれか1項に記載の電極材料。 The electrode material according to any one of claims 7 to 10, wherein the positive electrode active material comprises a Li 2 MnO 3 -based active material.
  12. 　活物質が加えられた芳香族系有機溶媒を加振処理することにより、前記芳香族系有機溶媒より生じた炭素系物質で、前記活物質の全表面或いはその一部表面を覆う工程を有することを特徴とする電極材料の製造方法。 A step of covering the entire surface of the active material or a part of the surface thereof with a carbon-based material generated from the aromatic organic solvent by subjecting the aromatic organic solvent to which the active material has been added to vibration treatment. A method for producing an electrode material.
  13. 　前記活物質を加えた芳香族系有機溶媒を加振処理する際に、
    　当該活物質を加えた芳香族系有機溶媒中で超音波を照射する請求項１２に記載の電極材料の製造方法。     When the aromatic organic solvent to which the active material is added is vibrated,
    The manufacturing method of the electrode material of Claim 12 which irradiates an ultrasonic wave in the aromatic organic solvent which added the said active material.
  14. 　前記超音波の周波数をｆとしたとき、前記周波数ｆは２０［ｋＨｚ］≦ｆ≦８００［ｋＨｚ］の周波数範囲から選択される請求項１３に記載の電極材料の製造方法。 14. The method for producing an electrode material according to claim 13, wherein the frequency f is selected from a frequency range of 20 [kHz] ≦ f ≦ 800 [kHz], where f is the frequency of the ultrasonic wave.
  15. 　前記超音波の出力をＺとしたとき、前記出力Ｚは１００［Ｗ］≦Ｚ≦８００［Ｗ］の出力範囲から選択される請求項１３又は１４に記載の電極材料の製造方法。 15. The method for producing an electrode material according to claim 13, wherein the output Z is selected from an output range of 100 [W] ≦ Z ≦ 800 [W], where Z is an output of the ultrasonic wave.
  16. 　前記超音波の照射時間をＹとしたとき、前記照射時間Ｙは０［ｈ］＜Ｙ≦１６［ｈ］の照射時間範囲から選択される請求項１３～１５のいずれか１項に記載の電極材料の製造方法。 The electrode according to any one of claims 13 to 15, wherein the irradiation time Y is selected from an irradiation time range of 0 [h] <Y ≤ 16 [h], where Y is the ultrasonic irradiation time. Material manufacturing method.
  17. 　前記炭素系物質で全表面或いはその一部表面が覆われた前記活物質を熱処理する工程を有する請求項１２～１６のいずれか１項に記載の電極材料の製造方法。 The method for producing an electrode material according to any one of claims 12 to 16, further comprising a step of heat-treating the active material whose entire surface or a part of the surface thereof is covered with the carbon-based material.
  18. 　前記活物質の熱処理時の温度をＨとしたとき、前記温度Ｈは１００［℃］≦Ｈ≦１２００［℃］の熱処理温度範囲から選択される請求項１７に記載の電極材料の製造方法。 18. The method for producing an electrode material according to claim 17, wherein the temperature H is selected from a heat treatment temperature range of 100 [° C.] ≦ H ≦ 1200 [° C., where H is a temperature during heat treatment of the active material.
  19. 　前記芳香族系有機溶媒には、塩化物、臭化物及びヨウ化物を含むハロゲン化ベンゼン、ハロゲン化された芳香族誘導体、ビニル基、アセチレン基、水酸基、アミノ基、ニトロ基、カルボキシル基、スルホン基を有する芳香族誘導体、５員環芳香族化合物、６員環芳香族化合物から選択される少なくとも一種からなる芳香族系化合物を含む液体；あるいは、前記芳香族系化合物を溶解させた溶液を用いる請求項１２～１８のいずれか１項に記載の電極材料の製造方法。 The aromatic organic solvent includes halogenated benzene including chloride, bromide and iodide, halogenated aromatic derivatives, vinyl group, acetylene group, hydroxyl group, amino group, nitro group, carboxyl group and sulfone group. A liquid containing at least one aromatic compound selected from an aromatic derivative, a 5-membered aromatic compound, and a 6-membered aromatic compound; or a solution in which the aromatic compound is dissolved. 19. The method for producing an electrode material according to any one of 12 to 18.
  20. 　集電体と、前記集電体上に設けられた電極材料とからなる電極であって、
    　前記電極材料は、活物質と、前記活物質の全表面あるいはその一部表面を覆う炭素系物質とからなり、前記炭素系物質は、前記活物質を加えた芳香族系有機溶媒に加振処理することにより生成されてなることを特徴とする電極。     An electrode comprising a current collector and an electrode material provided on the current collector,
    The electrode material includes an active material and a carbon-based material that covers the entire surface of the active material or a part of the active material, and the carbon-based material is subjected to vibration treatment in an aromatic organic solvent to which the active material is added. An electrode produced by performing the steps.
  21. 　正極及び負極と、前記正極と前記負極との間に設けられた電解質とを備え、
    　前記正極又は／及び前記負極は、集電体と、前記集電体上に設けられた電極材料とからなる電極であって、
    　前記電極材料は、活物質と、前記活物質の全表面あるいはその一部表面を覆う炭素系物質とからなり、前記炭素系物質は、前記活物質を加えた芳香族系有機溶媒に加振処理することにより生成されてなることを特徴とする二次電池。     A positive electrode and a negative electrode, and an electrolyte provided between the positive electrode and the negative electrode,
    The positive electrode and / or the negative electrode is an electrode composed of a current collector and an electrode material provided on the current collector,
    The electrode material includes an active material and a carbon-based material that covers the entire surface of the active material or a part of the active material, and the carbon-based material is subjected to vibration treatment in an aromatic organic solvent to which the active material is added. A secondary battery produced by performing the process.
  22. 　請求項２１に記載の二次電池を搭載したことを特徴とする車両。 A vehicle equipped with the secondary battery according to claim 21.
PCT/JP2012/002074 2011-03-28 2012-03-26 Electrode material, method for producing same, electrode, secondary battery, and vehicle WO2012132387A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2013507168A JPWO2012132387A1 (en) 2011-03-28 2012-03-26 ELECTRODE MATERIAL AND ITS MANUFACTURING METHOD, AND ELECTRODE, SECONDARY BATTERY AND VEHICLE

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2011-071173 2011-03-28
JP2011071173 2011-03-28

Publications (1)

Publication Number Publication Date
WO2012132387A1 true WO2012132387A1 (en) 2012-10-04

Family

ID=46930163

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2012/002074 WO2012132387A1 (en) 2011-03-28 2012-03-26 Electrode material, method for producing same, electrode, secondary battery, and vehicle

Country Status (2)

Country Link
JP (1) JPWO2012132387A1 (en)
WO (1) WO2012132387A1 (en)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014099368A (en) * 2012-11-15 2014-05-29 Sumitomo Metal Mining Co Ltd Positive electrode active material for nonaqueous electrolytic secondary battery use, and manufacturing method thereof
JP2014526783A (en) * 2011-09-13 2014-10-06 ワイルドキャット・ディスカバリー・テクノロジーズ・インコーポレイテッド Battery positive electrode
WO2015025443A1 (en) * 2013-08-21 2015-02-26 信越化学工業株式会社 Negative-electrode active substance, negative electrode active substance material, negative electrode, lithium ion secondary battery, negative electrode active substance manufacturing method, and lithium ion secondary battery manufacturing method
US20150099179A1 (en) * 2013-10-04 2015-04-09 Semiconductor Energy Laboratory Co., Ltd. Lithium manganese composite oxide, secondary battery, electronic device, and method for forming layer
WO2015063979A1 (en) * 2013-10-29 2015-05-07 信越化学工業株式会社 Negative electrode active material, production method for negative electrode active material, and lithium ion secondary battery
WO2016136226A1 (en) * 2015-02-27 2016-09-01 三洋電機株式会社 Method for manufacturing nonaqueous electrolyte secondary battery
WO2016157743A1 (en) * 2015-03-31 2016-10-06 ソニー株式会社 Negative electrode active material, method for producing same, negative electrode and battery
JP2016222530A (en) * 2015-05-28 2016-12-28 コリア インスティチュート オブ エナジー リサーチ Nitrogen-doped porous graphene cover formation process
JP2017506423A (en) * 2014-02-18 2017-03-02 ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツングＲｏｂｅｒｔ Ｂｏｓｃｈ Ｇｍｂｈ Graphene / HE-NCM composite for lithium ion battery, method for producing composite, electrode material including graphene / HE-NCM composite, and lithium ion battery
KR101839000B1 (en) * 2013-03-15 2018-04-26 나노 원 머티리얼즈 코포레이션. Complexometric precursor formulation methodology for industrial production of fine and ultrafine powders and nanopowders of layered lithium mixed metal oxides for battery applications
US10367188B2 (en) 2015-01-09 2019-07-30 Semiconductor Energy Laboratory Co., Ltd. Storage battery electrode, manufacturing method thereof, storage battery, and electronic device
WO2020149133A1 (en) * 2019-01-16 2020-07-23 信越化学工業株式会社 Negative electrode active substance for non-aqueous electrolyte secondary cell, non-aqueous electrolyte secondary cell, and method for manufacturing negative electrode material for non-aqueous electrolyte secondary cell
US10741828B2 (en) 2016-07-05 2020-08-11 Semiconductor Energy Laboratory Co., Ltd. Positive electrode active material including lithium cobaltate coated with lithium titanate and magnesium oxide
US11094927B2 (en) 2016-10-12 2021-08-17 Semiconductor Energy Laboratory Co., Ltd. Positive electrode active material particle and manufacturing method of positive electrode active material particle
JP7101821B2 (en) 2018-05-18 2022-07-15 国家能源投資集団有限責任公司 Silicon-carbon composite material, its manufacturing method and use
US11444274B2 (en) 2017-05-12 2022-09-13 Semiconductor Energy Laboratory Co., Ltd. Positive electrode active material particle
CN115974239A (en) * 2023-02-23 2023-04-18 广东工业大学 Particle electrode and preparation method and application thereof
US11670770B2 (en) 2017-06-26 2023-06-06 Semiconductor Energy Laboratory Co., Ltd. Method for manufacturing positive electrode active material, and secondary battery
US11799080B2 (en) 2017-05-19 2023-10-24 Semiconductor Energy Laboratory Co., Ltd. Positive electrode active material, method for manufacturing positive electrode active material, and secondary battery
CN115974239B (en) * 2023-02-23 2024-04-19 广东工业大学 Particle electrode and preparation method and application thereof

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004265733A (en) * 2003-02-28 2004-09-24 Tdk Corp Manufacturing method of electrode and manufacturing method of battery
JP2006228505A (en) * 2005-02-16 2006-08-31 Hitachi Chem Co Ltd Graphite particles for anode of lithium-ion secondary battery, its manufacturing method, as well as anode for lithium-ion secondary battery and lithium-ion secondary battery using the same
JP2008198610A (en) * 2007-02-14 2008-08-28 Samsung Sdi Co Ltd Negative electode active material, its manufacturing method, and negative electrode and lithium battery adopting it
JP2009212074A (en) * 2008-02-07 2009-09-17 Shin Etsu Chem Co Ltd Negative electrode material for nonaqueous electrolyte secondary battery, manufacturing method therefor, lithium ion secondary battery, and electrochemical capacitor
JP2010501970A (en) * 2006-08-22 2010-01-21 ビーティーアール・ニュー・エナジー・マテリアルズ・インク Silicon / carbon composite cathode material for lithium ion battery and method for producing the same
JP2010212228A (en) * 2009-02-13 2010-09-24 Hitachi Maxell Ltd Nonaqueous secondary battery
WO2012039477A1 (en) * 2010-09-24 2012-03-29 日立化成工業株式会社 Lithium ion battery, and battery module utilizing same

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004265733A (en) * 2003-02-28 2004-09-24 Tdk Corp Manufacturing method of electrode and manufacturing method of battery
JP2006228505A (en) * 2005-02-16 2006-08-31 Hitachi Chem Co Ltd Graphite particles for anode of lithium-ion secondary battery, its manufacturing method, as well as anode for lithium-ion secondary battery and lithium-ion secondary battery using the same
JP2010501970A (en) * 2006-08-22 2010-01-21 ビーティーアール・ニュー・エナジー・マテリアルズ・インク Silicon / carbon composite cathode material for lithium ion battery and method for producing the same
JP2008198610A (en) * 2007-02-14 2008-08-28 Samsung Sdi Co Ltd Negative electode active material, its manufacturing method, and negative electrode and lithium battery adopting it
JP2009212074A (en) * 2008-02-07 2009-09-17 Shin Etsu Chem Co Ltd Negative electrode material for nonaqueous electrolyte secondary battery, manufacturing method therefor, lithium ion secondary battery, and electrochemical capacitor
JP2010212228A (en) * 2009-02-13 2010-09-24 Hitachi Maxell Ltd Nonaqueous secondary battery
WO2012039477A1 (en) * 2010-09-24 2012-03-29 日立化成工業株式会社 Lithium ion battery, and battery module utilizing same

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PENGFEI GAO ET AL.: "Microporous carbon coated silicon core/shell nanocomposite via in situ polymerization for advanced Li-ion battery anode material", PHYSICAL CHEMISTRY CHEMICAL PHYSICS, vol. 11, no. 47, 21 December 2009 (2009-12-21), pages 11101 - 11105 *

Cited By (44)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014526783A (en) * 2011-09-13 2014-10-06 ワイルドキャット・ディスカバリー・テクノロジーズ・インコーポレイテッド Battery positive electrode
JP2014099368A (en) * 2012-11-15 2014-05-29 Sumitomo Metal Mining Co Ltd Positive electrode active material for nonaqueous electrolytic secondary battery use, and manufacturing method thereof
KR101839000B1 (en) * 2013-03-15 2018-04-26 나노 원 머티리얼즈 코포레이션. Complexometric precursor formulation methodology for industrial production of fine and ultrafine powders and nanopowders of layered lithium mixed metal oxides for battery applications
WO2015025443A1 (en) * 2013-08-21 2015-02-26 信越化学工業株式会社 Negative-electrode active substance, negative electrode active substance material, negative electrode, lithium ion secondary battery, negative electrode active substance manufacturing method, and lithium ion secondary battery manufacturing method
CN105474438B (en) * 2013-08-21 2018-07-31 信越化学工业株式会社 The manufacturing method of negative electrode active material, negative electrode active material material, negative electrode, lithium rechargeable battery, the manufacturing method of negative electrode active material and lithium rechargeable battery
US10566607B2 (en) 2013-08-21 2020-02-18 Shin-Etsu Chemical Co., Ltd. Negative electrode active material, raw material for a negative electrode active material, negative electrode, lithium ion secondary battery, method for producing a negative electrode active material, and method for producing a lithium ion secondary battery
US9935309B2 (en) 2013-08-21 2018-04-03 Shin-Etsu Chemical Co., Ltd. Negative electrode active material, raw material for a negative electrode active material, negative electrode, lithium ion secondary battery, method for producing a negative electrode active material, and method for producing a lithium ion secondary battery
CN105474438A (en) * 2013-08-21 2016-04-06 信越化学工业株式会社 Negative-electrode active substance, negative electrode active substance material, negative electrode, lithium ion secondary battery, negative electrode active substance manufacturing method, and lithium ion secondary battery manufacturing method
JP2015092468A (en) * 2013-10-04 2015-05-14 株式会社半導体エネルギー研究所 Lithium manganese composite oxide, secondary battery, and electronic apparatus, and method of manufacturing layer
TWI678836B (en) * 2013-10-04 2019-12-01 日商半導體能源研究所股份有限公司 Method for forming electrode material
US10454102B2 (en) 2013-10-04 2019-10-22 Semiconductor Energy Laboratory Co., Ltd. Lithium manganese composite oxide, secondary battery, electronic device, and method for forming layer
CN105594028A (en) * 2013-10-04 2016-05-18 株式会社半导体能源研究所 Lithium manganese composite oxide, secondary battery, electronic device, and method for forming layer
TWI648900B (en) * 2013-10-04 2019-01-21 日商半導體能源研究所股份有限公司 Method for forming an electrode material
WO2015050176A1 (en) * 2013-10-04 2015-04-09 Semiconductor Energy Laboratory Co., Ltd. Lithium manganese composite oxide, secondary battery, electronic device, and method for forming layer
US20150099179A1 (en) * 2013-10-04 2015-04-09 Semiconductor Energy Laboratory Co., Ltd. Lithium manganese composite oxide, secondary battery, electronic device, and method for forming layer
US10283756B2 (en) 2013-10-29 2019-05-07 Shin-Etsu Chemical Co., Ltd. Negative electrode active material, method for producing a negative electrode active material, and lithium ion secondary battery
US9929399B2 (en) 2013-10-29 2018-03-27 Shin-Etsu Chemical Co., Ltd. Negative electrode active material, method for producing a negative electrode active material, and lithium ion secondary battery
WO2015063979A1 (en) * 2013-10-29 2015-05-07 信越化学工業株式会社 Negative electrode active material, production method for negative electrode active material, and lithium ion secondary battery
JP2017506423A (en) * 2014-02-18 2017-03-02 ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツングＲｏｂｅｒｔ Ｂｏｓｃｈ Ｇｍｂｈ Graphene / HE-NCM composite for lithium ion battery, method for producing composite, electrode material including graphene / HE-NCM composite, and lithium ion battery
US11881578B2 (en) 2015-01-09 2024-01-23 Semiconductor Energy Laboratory Co., Ltd. Storage battery electrode, manufacturing method thereof, storage battery, and electronic device
US10923706B2 (en) 2015-01-09 2021-02-16 Semiconductor Energy Laboratory Co., Ltd. Storage battery electrode, manufacturing method thereof, storage battery, and electronic device
US10367188B2 (en) 2015-01-09 2019-07-30 Semiconductor Energy Laboratory Co., Ltd. Storage battery electrode, manufacturing method thereof, storage battery, and electronic device
US11545655B2 (en) 2015-01-09 2023-01-03 Semiconductor Energy Laboratory Co., Ltd. Storage battery electrode, manufacturing method thereof, storage battery, and electronic device
JPWO2016136226A1 (en) * 2015-02-27 2017-12-28 三洋電機株式会社 Method for producing non-aqueous electrolyte secondary battery
CN107431249A (en) * 2015-02-27 2017-12-01 三洋电机株式会社 The manufacture method of rechargeable nonaqueous electrolytic battery
WO2016136226A1 (en) * 2015-02-27 2016-09-01 三洋電機株式会社 Method for manufacturing nonaqueous electrolyte secondary battery
WO2016157743A1 (en) * 2015-03-31 2016-10-06 ソニー株式会社 Negative electrode active material, method for producing same, negative electrode and battery
US11804598B2 (en) 2015-03-31 2023-10-31 Murata Manufacturing Co., Ltd. Negative electrode active material and method for producing the same, negative electrode, and battery
JP2016222530A (en) * 2015-05-28 2016-12-28 コリア インスティチュート オブ エナジー リサーチ Nitrogen-doped porous graphene cover formation process
US9947926B2 (en) 2015-05-28 2018-04-17 Korea Institute Of Energy Research Method of forming nitrogen-doped porous graphene envelope
US11043660B2 (en) 2016-07-05 2021-06-22 Semiconductor Energy Laboratory Co., Ltd. Positive electrode active material including lithium cobaltate coated with lithium titanate and magnesium oxide
US10741828B2 (en) 2016-07-05 2020-08-11 Semiconductor Energy Laboratory Co., Ltd. Positive electrode active material including lithium cobaltate coated with lithium titanate and magnesium oxide
US11094927B2 (en) 2016-10-12 2021-08-17 Semiconductor Energy Laboratory Co., Ltd. Positive electrode active material particle and manufacturing method of positive electrode active material particle
US11444274B2 (en) 2017-05-12 2022-09-13 Semiconductor Energy Laboratory Co., Ltd. Positive electrode active material particle
US11489151B2 (en) 2017-05-12 2022-11-01 Semiconductor Energy Laboratory Co., Ltd. Positive electrode active material particle
US11799080B2 (en) 2017-05-19 2023-10-24 Semiconductor Energy Laboratory Co., Ltd. Positive electrode active material, method for manufacturing positive electrode active material, and secondary battery
US11670770B2 (en) 2017-06-26 2023-06-06 Semiconductor Energy Laboratory Co., Ltd. Method for manufacturing positive electrode active material, and secondary battery
JP7101821B2 (en) 2018-05-18 2022-07-15 国家能源投資集団有限責任公司 Silicon-carbon composite material, its manufacturing method and use
EP3913709A4 (en) * 2019-01-16 2022-10-12 Shin-Etsu Chemical Co., Ltd. Negative electrode active substance for non-aqueous electrolyte secondary cell, non-aqueous electrolyte secondary cell, and method for manufacturing negative electrode material for non-aqueous electrolyte secondary cell
JP2020113495A (en) * 2019-01-16 2020-07-27 信越化学工業株式会社 Negative electrode active material for nonaqueous electrolyte secondary battery, nonaqueous electrolyte secondary battery, and manufacturing method of negative electrode material for nonaqueous electrolyte secondary battery
WO2020149133A1 (en) * 2019-01-16 2020-07-23 信越化学工業株式会社 Negative electrode active substance for non-aqueous electrolyte secondary cell, non-aqueous electrolyte secondary cell, and method for manufacturing negative electrode material for non-aqueous electrolyte secondary cell
JP7098543B2 (en) 2019-01-16 2022-07-11 信越化学工業株式会社 A method for manufacturing a negative electrode active material for a non-aqueous electrolyte secondary battery, a non-aqueous electrolyte secondary battery, and a negative electrode material for a non-aqueous electrolyte secondary battery.
CN115974239A (en) * 2023-02-23 2023-04-18 广东工业大学 Particle electrode and preparation method and application thereof
CN115974239B (en) * 2023-02-23 2024-04-19 广东工业大学 Particle electrode and preparation method and application thereof

Also Published As

Publication number Publication date
JPWO2012132387A1 (en) 2014-07-24

Similar Documents

Publication Publication Date Title
WO2012132387A1 (en) Electrode material, method for producing same, electrode, secondary battery, and vehicle
Wang et al. NASICON-structured NaTi2 (PO4) 3@ C nanocomposite as the low operation-voltage anode material for high-performance sodium-ion batteries
CN108140786B (en) Method for producing lithium battery with ultra-high energy density
JP6448057B2 (en) Porous silicon-based negative electrode active material, manufacturing method thereof, and lithium secondary battery including the same
JP6593330B2 (en) Nanocarbon composite and method for producing the same
EP2874211B1 (en) Transition metal-pyrophosphate anode active material, manufacturing method therefor, and lithium secondary battery or hybrid capacitor comprising same
US20140072879A1 (en) Encapsulated phthalocyanine particles, high-capacity cathode containing these particles, and rechargeable lithium cell containing such a cathode
JP6511726B2 (en) Negative electrode material for lithium ion secondary battery, negative electrode for lithium ion secondary battery and lithium ion secondary battery
JP5534363B2 (en) Composite nanoporous electrode material, production method thereof, and lithium ion secondary battery
KR20220020407A (en) Carbon material for negative electrode of nonaqueous rechargeable battery, negative electrode for nonaqueous rechargeable battery, and nonaqueous rechargeable battery
KR20120128125A (en) High capacity anode materials for lithium ion batteries
JP5756781B2 (en) Silicon composite, method for producing the same, negative electrode active material, and non-aqueous secondary battery
JP6288257B2 (en) Nanosilicon material, method for producing the same, and negative electrode of secondary battery
TWI485919B (en) Process for producing cathode active material for use in lithium secondary battery
Zhang et al. A facile approach to nanoarchitectured three-dimensional graphene-based Li–Mn–O composite as high-power cathodes for Li-ion batteries
US10923720B2 (en) Graphene-enabled selenium cathode active material for an alkali metal-selenium secondary battery
Hsieh et al. Electrochemical performance of lithium iron phosphate cathodes at various temperatures
JP5725075B2 (en) Secondary battery negative electrode binder, secondary battery negative electrode, and lithium ion secondary battery
Chen et al. Anatase-TiO2 nanocoating of Li4Ti5O12 nanorod anode for lithium-ion batteries
KR20220143991A (en) The immobilization selenium, and the use of the immobilization selenium in the manufacturing method thereof and recharging battery
WO2013161749A1 (en) Anode for secondary battery, method for producing same, and secondary battery
TWI670894B (en) Positive electrode active material for secondary battery and method for producing same
WO2019199770A1 (en) Graphene-enabled selenium cathode active material for an alkali metal-selenium secondary battery
US20190312267A1 (en) Production process for graphene-enabled selenium cathode active material for an alkali metal-selenium secondary battery
KR102365020B1 (en) Method for Preparing Composite Materials Using Slurries Containing Reduced Graphene Oxide

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12762926

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2013507168

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12762926

Country of ref document: EP

Kind code of ref document: A1