WO2017002959A1 - リチウムイオン電池用負極材及びその用途 - Google Patents
リチウムイオン電池用負極材及びその用途 Download PDFInfo
- Publication number
- WO2017002959A1 WO2017002959A1 PCT/JP2016/069633 JP2016069633W WO2017002959A1 WO 2017002959 A1 WO2017002959 A1 WO 2017002959A1 JP 2016069633 W JP2016069633 W JP 2016069633W WO 2017002959 A1 WO2017002959 A1 WO 2017002959A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- negative electrode
- particles
- electrode material
- less
- lithium ion
- Prior art date
Links
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
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/364—Composites as mixtures
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/20—Graphite
- C01B32/205—Preparation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/02—Silicon
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/113—Silicon oxides; Hydrates thereof
- C01B33/12—Silica; Hydrates thereof, e.g. lepidoic silicic acid
- C01B33/18—Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- 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
- H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
-
- 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
- H01M4/134—Electrodes based on metals, Si or alloys
-
- 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
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
- H01M4/386—Silicon or alloys based on silicon
-
- 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
- H01M4/483—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides for non-aqueous cells
-
- 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
- H01M4/58—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
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/74—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by peak-intensities or a ratio thereof only
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/78—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by stacking-plane distances or stacking sequences
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/51—Particles with a specific particle size distribution
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/62—Submicrometer sized, i.e. from 0.1-1 micrometer
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/12—Surface area
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/14—Pore volume
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/16—Pore diameter
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/40—Electric properties
-
- 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
- H01M2004/021—Physical characteristics, e.g. porosity, surface area
-
- 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
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/028—Positive electrodes
-
- 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 negative electrode material for a lithium ion battery and its use. More specifically, the present invention relates to a negative electrode material capable of obtaining a lithium ion battery having a large charge / discharge capacity and excellent charge / discharge cycle characteristics, a paste containing the negative electrode material, and a negative electrode sheet formed by applying the paste. And a lithium ion battery having the negative electrode sheet.
- the power consumption of portable electronic devices is increasing due to the multi-functionalization of portable electronic devices at a speed exceeding the power saving of electronic components. Therefore, higher capacity and smaller size of the lithium ion battery, which is the main power source of portable electronic devices, are more strongly demanded than ever. In addition, the demand for electric vehicles is increasing, and the lithium-ion batteries used there are also strongly required to have a high capacity.
- Patent Document 1 proposes a negative electrode material obtained by fixing Si ultrafine particles formed by a gas evaporation method to the surface of graphite particles by mechanochemical treatment, mixing petroleum mesophase pitch, and then carbonizing.
- ultrafine particles have a very large surface activity, so that the particles aggregate and are difficult to disperse into single particles. That is, even when the mechanochemical treatment is employed, the ultrafine particles are not adhered to the graphite surface in a state of being dispersed in a single particle, but are adhered as aggregated particles. Even in Patent Document 1, even if mechanochemical treatment is performed, since the surface activity of the Si ultrafine particles themselves is not controlled, the Si ultrafine particles themselves adhere to the graphite surface in a state of being dispersed in a single particle. Because it is attached as aggregated particles, the expansion and contraction associated with the insertion / desorption (occlusion / release) of lithium ions occurs in the aggregated particle state and the composite structure is destroyed. not enough. Thus, the improvement of the charge / discharge cycle life when Si is used as the negative electrode material as a metal element capable of forming an alloy with lithium is not yet sufficient, and further improvement is required.
- a negative electrode material for a lithium ion battery including silicon-containing particles, artificial graphite particles, and a carbonaceous material, wherein at least a part of the silicon-containing particles, the artificial graphite particles, and the carbonaceous material are combined.
- Composite particles, The silicon-containing particles are silicon particles having a SiOx layer (0 ⁇ x ⁇ 2) on the particle surface, and an oxygen content is 1.0% by mass or more and 18.0% by mass or less, and a primary particle of 200 nm or less.
- the main component is a particle having a diameter
- the said artificial graphite particle is a negative electrode material for lithium ion batteries whose particle diameter D50 at the time of 50% accumulation in the volume reference
- standard accumulation particle size distribution by a laser diffraction method is 1.0 micrometer or more and 15.0 micrometers or less.
- a ratio I 110 / I 004 between the peak intensity I 110 of the ( 110 ) plane and the peak intensity I 004 of the (004) plane of the graphite crystal obtained from powder XRD measurement is 0.10 or more and 0.
- Non-flaky artificial graphite particles having a total pore volume of 5.0 ⁇ L / g or more and 40.0 ⁇ L / g or less, and the optical structure observed in the cross section of the artificial graphite particles has a small area The area from the tissue is accumulated, the area of the optical tissue when the cumulative area is 60% of the total optical tissue area is SOP, and the number of tissues is counted from the tissue with a small aspect ratio to 60% of the total number of tissues.
- a particle size of 50% cumulative time a volume-based cumulative particle size distribution by laser diffraction method was D50, 1.5 ⁇ AROP ⁇ 6.0 and 0.2 ⁇ D50 ⁇ (SOP ⁇ AROP) 1/2 ⁇ 2 ⁇ D50 2.
- the negative electrode material for a lithium ion battery as described in 1 above which has the following relationship: [3] The negative electrode material for a lithium ion battery according to the above 1 or 2, wherein the artificial graphite particles have a particle diameter D50 at 50% accumulation in a volume-based cumulative particle size distribution by laser diffraction method of 10.0 ⁇ m or less.
- the amount of the carbonaceous material is 2.0% by mass or more and 40.0% by mass or less based on the total of the silicon-containing particles, the artificial graphite particles, and the carbonaceous material.
- the negative electrode material for a lithium ion battery has a peak intensity ID of a peak in the range of 1300 to 1400 cm ⁇ 1 measured by a Raman spectroscopic spectrum when the composite particles are measured with a microscopic Raman spectrophotometer, and 1580 to The lithium according to any one of 1 to 9 above, wherein a ratio I D / I G (R value) with a peak intensity I G of a peak in the range of 1620 cm ⁇ 1 is 0.15 or more and 1.00 or less.
- Negative electrode material for ion batteries [11] A paste comprising the negative electrode material for a lithium ion battery according to any one of 1 to 10 and a binder. [12] A negative electrode for a lithium ion battery, comprising the molded article of the paste as described in 11 above. [13] A lithium ion battery including the negative electrode described in 12 as a constituent element.
- the negative electrode material of the present invention has a large discharge capacity per mass and excellent initial efficiency. By using this negative electrode material, a lithium ion battery having a large capacity and excellent charge / discharge cycle characteristics can be obtained.
- the particle surface layer contains SiOx (0 ⁇ x ⁇ 2).
- the portion (core) other than the surface layer may be made of elemental silicon or SiOx (0 ⁇ x ⁇ 2).
- the average thickness of the surface layer containing SiOx is preferably 0.5 nm or more and 10.0 nm or less.
- the average thickness of the surface layer containing SiOx is 0.5 nm or more, oxidation due to air or an oxidizing gas can be suppressed.
- capacitance at the time of an initial cycle can be suppressed as the average thickness of the surface layer containing SiOx is 10.0 nm or less. This average thickness can be measured by a TEM photograph.
- the silicon-containing particles have an oxygen content of preferably 1.0% by mass or more and 18.0% by mass or less, more preferably 2.0% by mass or more and 10.0% by mass or less. Within this range, an increase in irreversible capacity during the initial cycle can be suppressed.
- the oxygen content can be quantified by, for example, an oxygen-nitrogen simultaneous analyzer (inert gas melting-infrared absorption method).
- the silicon-containing particles are preferably composed mainly of particles having a primary particle size of 200 nm or less. Specifically, the 90% diameter is preferably 200 nm or less in the number-based cumulative distribution of the primary particle diameter.
- the primary particle diameter can be measured by observation with a microscope such as SEM or TEM.
- the primary particle diameter of the silicon-containing particles formed into a composite can be calculated by image analysis of an image of spherical particles observed with a transmission electron microscope having a magnification of 100,000 times.
- the silicon-containing particles can contain, in addition to silicon, an element M selected from other metal elements and metalloid elements (such as carbon elements).
- an element M selected from other metal elements and metalloid elements (such as carbon elements).
- Specific examples of the element M include nickel, copper, iron, tin, aluminum, and cobalt.
- the content of the element M is not particularly limited as long as it does not significantly inhibit the action of silicon, and is, for example, 1 mol or less per 1 mol of silicon atoms.
- the silicon-containing particles are not particularly limited by the production method.
- it can be produced by the method disclosed in WO2012 / 000858A1.
- the amount of silicon-containing particles contained in the negative electrode material is preferably 5.0 parts by mass or more and 30.0 parts by mass or less, more preferably 7.0 parts by mass or more and 25.0 parts by mass with respect to 100 parts by mass of the artificial graphite particles. Or less.
- the amount of silicon-containing particles is small, the effect of improving battery capacity by adding the particles tends to be poor.
- the amount of silicon-containing particles is large, the volume change associated with the insertion and desorption of lithium ions tends to increase.
- the graphite particles Since the graphite particles are hard when the structure is complicated, it is preferable that the graphite particles have a large structure in order to improve the electrode density.
- the structures observed in the graphite particles include optical anisotropy due to the development of crystals and alignment of the graphite network surface, and the occurrence of crystals that are undeveloped or due to large crystal turbulence such as hard carbon. It has been known for a long time that there is an organization showing isotropic properties. For the observation of these structures, it is possible to measure the size of the crystallite by using X-ray diffraction method.
- the artificial graphite particles according to a preferred embodiment of the present invention have an optical structure having a size and a shape within a specific range, and further having an appropriate degree of graphitization, so that both the crushing characteristics as an electrode material and the battery characteristics are excellent. Become a material.
- the artificial graphite particles in the preferred embodiment of the present invention satisfy the following formula. 1.5 ⁇ AROP ⁇ 6.0 and 0.2 ⁇ D50 ⁇ (SOP ⁇ AROP) 1/2 ⁇ 2 ⁇ D50
- SOP refers to an optical structure observed using a polarizing microscope in a cross section of the molded body of the artificial graphite particles, and the area is accumulated from a small area structure, and the accumulated area is 60% of the total optical structure area. Represents the area of the optical structure.
- AROP represents the aspect ratio in the tissue that is 60% of the total number of tissues by counting the number of tissues from the tissues having a small aspect ratio.
- D50 is the particle diameter at the time of 50% accumulation in the volume-based cumulative particle size distribution by the laser diffraction method.
- the optical structure in the carbon material hardens while flowing, it often has a band shape, and when the cross section of the carbon material is observed, the shape of the optical structure is generally rectangular, and the area is short of the optical structure. It can be estimated that the diameter is multiplied by the major axis.
- the minor axis is the major axis / aspect ratio. If it is assumed that the optical structure to be subjected to the area SOP and the optical structure to be subjected to the aspect ratio AROP are the same, the major axis in the optical structure is (SOP ⁇ AROP) 1/2 . That is, (SOP ⁇ AROP) 1/2 assumes a long axis of an optical structure having a specific size, and the above formula shows that the optical structure has a certain size or more depending on the ratio of DSOP to D50. It prescribes.
- (SOP ⁇ AROP) 1/2 assuming the major axis of the optical texture is usually smaller than D50, but when (SOP ⁇ AROP) 1/2 and the value of D50 are close, the particles in the carbon material are more It means that it consists of a small number of optical structures, and when (SOP ⁇ AROP) 1/2 is small relative to D50, it means that the particles in the carbon material contain a large number of optical structures.
- the value of (SOP ⁇ AROP) 1/2 is 0.2 ⁇ D50 or more, there are few boundaries of the optical structure, which is convenient for the diffusion of lithium ions, so that charge / discharge can be performed at a high speed. Moreover, the larger the value, the more lithium ions that can be retained.
- the value is preferably 0.25 ⁇ D50 or more, more preferably 0.28 ⁇ D50 or more, and further preferably 0.35 ⁇ D50 or more.
- the upper limit is less than 2 ⁇ D50, but is preferably 1 ⁇ D50 or less.
- D50 represents the 50% cumulative diameter measured on a volume basis in a laser diffraction particle size distribution meter, and indicates the apparent diameter of the particle.
- the laser diffraction type particle size distribution analyzer for example, Mastersizer (registered trademark) manufactured by Malvern can be used.
- D50 of the artificial graphite particles in a preferred embodiment of the present invention is 1 ⁇ m or more and 15 ⁇ m or less. Preferably they are 1 micrometer or more and 10 micrometers or less, More preferably, they are 1 micrometer or more and 7 micrometers or less. In order to make D50 less than 1 ⁇ m, it is necessary to pulverize with special equipment at the time of pulverization, and more energy is required. In addition, handling such as agglomeration and coatability is difficult, the specific surface area becomes excessively large, and the initial charge / discharge efficiency is lowered.
- the aspect ratio AROP of the artificial graphite particles is 1.5 or more and 6.0 or less. More preferably, it is 2.0 or more and 4.0 or less, More preferably, it is 2.0 or more and 2.3 or less.
- AROP is larger than the above lower limit value, it is preferable because the structures slip and it is easy to obtain a high-density electrode, and when it is not more than the upper limit value, the energy required for synthesizing the raw material is small.
- the optical tissue observation and analysis method is as follows. [Preparation of polarizing microscope observation sample]
- the “cross section of the carbon material” in the present invention is prepared as follows. A double-sided tape is affixed to the bottom of a plastic sample container having an internal volume of 30 cm 3 , and about 2 cups of spatula (about 2 g) are placed on the sample.
- Cold embedding resin (trade name: cold embedding resin # 105, manufacturer: Japan Composite Co., Ltd., sales company: Marumoto Struers Co., Ltd.)
- curing agent trade name: curing agent (M agent), Manufacturing company: Nippon Oil & Fats Co., Ltd., sales company: Marumoto Struers Co., Ltd.) and knead for 30 seconds.
- the obtained mixture (about 5 ml) is slowly poured into the sample container until it reaches a height of about 1 cm, and allowed to stand for 1 day to solidify.
- the solidified sample is taken out and the double-sided tape is peeled off.
- the surface to be measured is polished using a polishing plate rotating type polishing machine.
- Polishing is performed by pressing the polishing surface against the rotating surface.
- the polishing plate is rotated at 1000 rpm.
- the counts of the polishing plates are # 500, # 1000, and # 2000 in order, and finally alumina (trade name: Baikalox (registered trademark) type 0.3CR, particle size 0.3 ⁇ m, manufacturer: Baikowski Polishing using a sales company: Baikowski Japan).
- the polished sample is fixed with clay on a preparation and observed using a polarizing microscope (OLYMPUS, BX51).
- Statistic processing for the detected organization is performed using an external macro.
- the black portion that is, the portion corresponding to the resin portion instead of the optical structure is excluded from the statistical object, and the area and aspect ratio of each structure are calculated for each of the blue, yellow, and red optical structures.
- the artificial graphite particles in a preferred embodiment of the present invention are non-flaky artificial graphite particles. This is to prevent the orientation of the carbon network layer during electrode production using the negative electrode material. Orientation is used as an index for evaluation of scalyness. That is, the artificial graphite particles according to a preferred embodiment of the present invention have a ratio of the peak intensity I 110 of the ( 110 ) plane and the peak intensity I 004 of the (004) plane in the XRD pattern obtained from the powder X-ray diffraction measurement. I 110 / I 004 is 0.10 or more and 0.35 or less. The ratio is preferably 0.18 or more and 0.30 or less, and more preferably 0.21 or more and 0.30 or less.
- the electrode Since the artificial graphite particles having a ratio lower than 0.1 have too high orientation, the electrode is caused by expansion and contraction accompanying insertion / desorption (occlusion / release) of lithium ions into / from Si and graphite in the negative electrode material. Electrode expansion in the direction perpendicular to the current collector surface tends to occur, which is disadvantageous in cycle life. Further, since the carbon network surface is parallel to the electrode surface, Li insertion is difficult to occur, and the rapid charge / discharge characteristics are deteriorated. Since the artificial graphite particles having a value higher than 0.35 have an orientation too low, the electrode density is difficult to increase when pressing is performed when an electrode is produced using the negative electrode material.
- the orientation of the particles is related to the optical structure described above.
- the artificial graphite particles in a preferred embodiment of the present invention have an average circularity of 0.80 to 0.95.
- the average circularity is small, but when the particles are scale-like, as described above, the electrode using the negative electrode material is likely to expand and the cycle life or In the case where the rapid charge / discharge property is reduced and the strain is generated, the gap between the particles becomes large at the time of producing the electrode, so that the electrode density is hardly increased.
- the average circularity is too high, the contact between the particles becomes small when the electrode is produced, and the resistance is high and the input / output characteristics are deteriorated. It is preferably 0.83 to 0.93, more preferably 0.85 to 0.90.
- the average circularity is calculated from the frequency distribution of circularity analyzed for 10,000 or more particles in the LPF mode using FPIA-3000 (manufactured by Sysmex Corporation).
- the circularity is obtained by dividing the circumference of a circle having the same area as the area of the observed particle image by the circumference of the particle image, and the closer to 1, the closer to a perfect circle.
- the artificial graphite particles have an average interplanar spacing d002 of (002) plane of 0.3360 nm or less by X-ray diffraction.
- the artificial graphite particles themselves in the negative electrode material also have a large amount of lithium insertion / extraction per mass, that is, the weight energy density of the negative electrode material also increases.
- the expansion and contraction accompanying the insertion and desorption of lithium into Si as the negative electrode material can be easily relaxed, and the cycle life is improved.
- the thickness Lc in the C-axis direction of the crystallites of the artificial graphite particles is preferably from 50 nm to 1000 nm from the viewpoint of weight energy density and collapsibility.
- d002 and Lc can be measured by a known method using a powder X-ray diffraction (XRD) method (Inada Inokichi, Michio Inagaki, Japan Society for the Promotion of Science, 117th Committee Sample, 117-71-A-1 (1963), Michio Inagaki et al., Japan Society for the Promotion of Science, 117th Committee Sample, 117-121-C-5 (1972), Michio Inagaki, “Carbon”, 1963, No. 36, pages 25-34).
- XRD powder X-ray diffraction
- the artificial graphite particles have a BET specific surface area of 1.0 m 2 / g or more and 9.0 m 2 / g or less, and more preferably 3.0 m 2 / g or more and 7.5 m 2 / g or less. . If the BET specific surface area of the artificial graphite particles is less than 1.0 m 2 / g, the silicon-containing particles and the pitch that is the precursor of the carbonaceous material are difficult to be combined with the artificial graphite particles, and the cycle life is not improved sufficiently. .
- the BET specific surface area of the artificial graphite particles exceeds 9.0 m 2 / g, the BET specific surface area as the negative electrode material also increases, causing irreversible side reactions on the surface of the active material, Excessive use is required. Furthermore, when the BET specific surface area of the artificial graphite particles is in the above range, the input / output characteristics are improved because a large area in contact with the electrolytic solution can be secured while suppressing irreversible side reactions as the negative electrode material.
- the BET specific surface area is measured by a general method of measuring the amount of adsorption / desorption of gas per unit mass.
- NOVA-1200 can be used as the measuring device.
- the total pore volume of pores having a diameter of 0.4 ⁇ m or less by a nitrogen gas adsorption method under liquid nitrogen cooling is 5.0 ⁇ L / g or more and 40.0 ⁇ L / g or less. . More preferably, it is 25.0 ⁇ L / g or more and 40.0 ⁇ L / g or less.
- the silicon-containing particles and the pitch that is the precursor of the carbonaceous material are easily combined with the artificial graphite particles, which is preferable in terms of improving the cycle life.
- the total pore volume is 40.0 ⁇ L / g or less in a carbon material having an Lc measured by an X-ray diffraction method of 100 nm or more, a structure resulting from anisotropic expansion and contraction of the graphite layer during charge and discharge The irreversible change is less likely to occur, and the cycle characteristics as the negative electrode material are further improved.
- the total pore volume of the artificial graphite particles is within this range, the electrolyte solution is likely to penetrate even when the negative electrode material is used as an active material, which is preferable in terms of rapid charge / discharge characteristics.
- the artificial graphite particles have a peak intensity (peak height) ID and 1580 to 1620 cm ⁇ derived from an amorphous component in the range of 1300 to 1400 cm ⁇ 1 as measured by Raman spectroscopy.
- the ratio I D / I G (R value) to the intensity (peak height) I G of the peak derived from the graphite component in the range of 1 is preferably 0.04 or more and 0.18 or less, and 0.08 or more and 0.0. 16 or less is more preferable. When the R value is less than 0.04, the rapid charge / discharge characteristics tend to deteriorate because the graphite crystallinity is too high.
- the Raman spectrum can be measured, for example, by observing with an attached microscope using NRS-5100 manufactured by JASCO Corporation.
- the artificial graphite particles in a preferred embodiment of the present invention can be produced by heating particles obtained by pulverizing coke having a heat history of 1000 ° C. or less.
- a raw material for coke for example, petroleum pitch, coal pitch, coal pitch coke, petroleum coke, and a mixture thereof can be used. Among these, those subjected to delayed coking under specific conditions are desirable.
- decant oil obtained by removing the catalyst after carrying out fluidized bed catalytic cracking on heavy distillate during refining of crude oil, or coal tar extracted from bituminous coal, etc. has a temperature of 200 ° C or higher. And those having sufficient fluidity by raising the temperature of the tar obtained to 100 ° C. or higher.
- these liquids are heated to 450 ° C. or higher, more preferably 500 ° C., and even more preferably 510 ° C. or more at least at the inlet in the drum, so The charcoal rate is increased and the yield is improved.
- the pressure in the drum is preferably maintained at normal pressure or higher, more preferably 300 kPa or higher, and further preferably 400 kPa or higher. Thereby, the capacity
- coke is performed under conditions severer than usual, so that the liquid can be reacted more and coke having a higher degree of polymerization can be obtained.
- the obtained coke is cut out from the drum by a jet water flow, and the obtained lump is roughly pulverized to about 5 cm with a hammer.
- a biaxial roll crusher or a jaw crusher can be used, but pulverization is preferably performed so that the amount on a 1 mm sieve is 90% by mass or more. If excessive pulverization is performed to such an extent that fine powder with a particle size of 1 mm or less is generated in large quantities, there is a risk that in the subsequent heating process, after drying, coke powder will rise or burnout will increase. There is.
- the coke preferably has a specific optical texture area and aspect ratio in a specific range.
- the area and aspect ratio of the optical structure can be calculated by the above-described method. However, when coke is obtained as a mass of several centimeters in size, it is embedded in resin as it is and mirrored. The cross section is observed with a polarizing microscope, and the area and aspect ratio of the optical structure are calculated.
- an optical structure in which the area is accumulated from a small area, and the accumulated area is 60% of the total optical structure area preferably the area of is 50 [mu] m 2 or more 5000 .mu.m 2 or less, more preferably 100 [mu] m 2 or more 3000 .mu.m 2 or less, and most preferably 100 [mu] m 2 or more 160 .mu.m 2 or less.
- the number of tissues is counted from a structure with a small aspect ratio, and the aspect ratio in the 60th tissue of the total number of tissues is 1.5 or more and 6 or less. It is more preferably 0.0 or more and 3.0 or less, and most preferably 2.3 or more and 2.6 or less.
- the coke is ground.
- the coke has a high heat history, the crushing strength will be strong and the grindability will be poor, and the crystal anisotropy will develop, so that the cleaving property will be strong and the powder will be flaky.
- pulverize there is no restriction
- the pulverization is preferably performed so that D50 is 1.0 ⁇ m or more and 15.0 ⁇ m or less. More preferably, it is pulverized so as to be 1.0 ⁇ m or more and 10.0 ⁇ m or less, and more preferably 1.0 ⁇ m or more and 7.0 ⁇ m or less.
- Graphitization is preferably performed at a temperature of 2400 ° C. or higher, more preferably 2800 ° C. or higher, more preferably 3050 ° C. or higher, and most preferably 3150 ° C. or higher.
- the treatment is performed at a higher temperature, a graphite crystal grows more, and an electrode capable of storing lithium ions at a higher capacity can be obtained.
- the graphitization temperature is preferably 3600 ° C. or lower.
- the carbon raw material is calcined prior to graphitization and the organic volatiles are removed, that is, the fixed carbon content is 95% or more, more preferably 98% or more, More preferably, it is 99% or more.
- This calcination can be performed by heating at 700 to 1500 ° C., for example. Since the mass reduction at the time of graphitization is reduced by firing, it is possible to increase the amount of treatment once in the graphitization apparatus.
- the carbonaceous material in a preferred embodiment of the present invention is a carbon material that is different from the artificial graphite particles and has a low growth of crystals formed by carbon atoms, and has a peak in the vicinity of 1360 cm ⁇ 1 due to Raman scattering. Have.
- the carbonaceous material can be produced, for example, by carbonizing a carbon precursor.
- the carbon precursor is not particularly limited, but is a hot heavy oil, pyrolysis oil, straight asphalt, blown asphalt, petroleum-derived substances such as tar or petroleum pitch produced during ethylene production, coal tar produced during coal dry distillation, A heavy component obtained by distilling off a low boiling point component of coal tar and a coal-derived substance such as coal tar pitch (coal pitch) are preferable, and petroleum-based pitch or coal-based pitch is particularly preferable.
- the pitch is a mixture of a plurality of polycyclic aromatic compounds. If pitch is used, a carbonaceous material with few impurities can be manufactured with a high carbonization rate. Since pitch has a low oxygen content, silicon-containing particles are less likely to be oxidized when silicon-containing particles are coated with a carbonaceous material.
- the pitch as the carbonaceous material precursor has a softening point of preferably 80 ° C. or higher and 300 ° C. or lower.
- a pitch having a softening point that is too low has a low average molecular weight and a high volatile content of the polycyclic aromatic compound constituting the pitch, resulting in a low carbonization rate, an increased production cost, and a large number of pores. It is easy to obtain a carbonaceous material having a large specific surface area. Pitches having a softening point that is too high tend to be difficult to mix uniformly with silicon-containing particles because of their high viscosity.
- the pitch softening point can be measured by the Mettler method described in ASTM-D3104-77.
- the pitch as the precursor of the carbonaceous material has a residual carbon ratio of preferably 20% by mass to 70% by mass, and more preferably 25% by mass to 60% by mass.
- a pitch with a low residual carbon ratio When a pitch with a low residual carbon ratio is used, the manufacturing cost is increased, and a carbonaceous material having a large specific surface area is easily obtained.
- a pitch having a high residual carbon ratio generally has a high viscosity, and therefore, it tends to be difficult to uniformly mix the silicon-containing particles.
- the remaining coal rate is determined by the following method.
- the solid pitch is pulverized with a mortar or the like, and the pulverized product is subjected to mass thermal analysis under a nitrogen gas flow.
- the ratio of the mass at 1100 ° C. to the charged mass is defined as the residual carbon ratio.
- the residual carbon ratio corresponds to the amount of fixed carbon measured at a carbonization temperature of 1100 ° C. in JIS K2425.
- the pitch used in the present invention has a QI (quinoline insoluble content) content of preferably 10% by mass or less, more preferably 5.0% by mass or less, and further preferably 2.0% by mass or less.
- the QI content of the pitch is a value corresponding to the amount of free carbon.
- the pitch used in the present invention has a TI (toluene insoluble content) content of preferably 10.0% by mass or more and 70.0% by mass or less.
- a pitch with a low TI content has a low average molecular weight of the polycyclic aromatic compound constituting it and a large amount of volatile matter, resulting in a low carbonization rate, an increase in production cost, and a large specific surface area containing many pores. It is easy to obtain a carbonaceous material.
- a pitch with a high TI content has a high carbonization rate because the average molecular weight of the polycyclic aromatic compound constituting it is high, but a pitch with a high TI content has a high viscosity and is difficult to mix uniformly with silicon-containing particles. Tend. When the TI content is in the above range, the pitch and other components can be uniformly mixed, and a negative electrode material exhibiting characteristics suitable as a battery active material can be obtained.
- the QI content and TI content of the pitch used in the present invention can be measured by the method described in JIS K2425 or a method based thereon.
- the amount of the carbonaceous material is preferably 2.0% by mass or more and 40.0% by mass or less, more preferably 4.0% by mass or more, based on the total of the silicon-containing particles, the artificial graphite particles, and the carbonaceous material. It is 30.0 mass% or less.
- the amount of the carbonaceous material is less than 2.0% by mass, the bonding between the silicon-containing particles and the artificial graphite particles is not sufficient, and the surface of the silicon-containing particles cannot be covered with the carbonaceous material. It is difficult to impart electrical conductivity to the surface, and the effect of suppressing the surface reactivity of Si and the effect of relaxing expansion and contraction tend to be low, and the cycle characteristics tend to deteriorate.
- it exceeds 40.0 mass% there exists a tendency for initial efficiency to become low depending on the amount of carbonaceous materials.
- a negative electrode material includes silicon-containing particles, artificial graphite particles, and a carbonaceous material, and at least a part of the silicon-containing particles, the artificial graphite particles, and the carbonaceous material are combined with each other. It is preferable that the composite particles are formed.
- Compounding means, for example, a state in which silicon-containing particles and artificial graphite particles are fixed and bonded by a carbonaceous material to form composite particles, or silicon-containing particles and / or artificial graphite particles are carbonaceous materials. The state which is coat
- the silicon-containing particles are completely covered with the carbonaceous material and Si is not exposed.
- the silicon-containing particles and the artificial graphite particles are connected via the carbonaceous material.
- the whole is coated with the carbonaceous material to form composite particles, and the silicon-containing particles and the artificial graphite particles are in direct contact, and the whole is coated with the carbonaceous material to form composite particles.
- the state is preferable.
- the surface of the silicon-containing particles is not exposed, so that the electrolytic decomposition reaction is suppressed and coulomb efficiency can be maintained high, and artificial graphite particles and silicon-containing particles can be maintained via carbonaceous materials.
- the conductivity between them can be increased, and the silicon-containing particles can be covered with the carbonaceous material, so that the volume change accompanying expansion and contraction can be buffered.
- the negative electrode material according to an embodiment of the present invention may include artificial graphite particles, carbonaceous material, or silicon-containing particles that are not combined. It is preferable that the amount of artificial graphite particles, carbonaceous material, or silicon-containing particles contained alone without being composited is smaller, specifically, preferably 10% by mass or less with respect to the mass of the negative electrode material. is there.
- the particle diameter D50 at 50% accumulation in the volume-based cumulative particle size distribution by the laser diffraction method is preferably 2.0 ⁇ m or more and 18.0 ⁇ m or less. More preferably, it is 4.0 ⁇ m or more and 10.0 ⁇ m or less. If the D50 is less than 2.0 ⁇ m, the negative electrode material production is inferior in economic efficiency, and handling such as a decrease in coating property becomes difficult, and a large amount of binder is required for electrode production, the electrode density is difficult to increase, and the specific surface area is excessive. The initial charge / discharge efficiency decreases due to side reactions with the electrolyte.
- the BET specific surface area is preferably 2.0 m 2 / g or more and 10.0 m 2 / g or less. More preferably not more than 4.0 m 2 / g or more 8.0 m 2 / g.
- the BET specific surface area is less than 2.0 m 2 / g, the input / output characteristics are lowered, the uniform distribution in the electrode is lowered, and the cycle characteristics are lowered.
- the BET specific surface area exceeds 10.0 m 2 / g, handling becomes difficult, such as a decrease in coating properties, and it becomes difficult to increase the electrode density by requiring a large amount of binder for electrode preparation. Discharge efficiency decreases.
- the composite surface is excessively crushed and the Si surface is exposed, the effect of suppressing the surface reactivity of the silicon-containing particles and the effect of relaxing expansion and contraction are reduced, so that the cycle characteristics are likely to deteriorate. .
- the average interplanar spacing d002 of the (002) plane of the graphite particles by X-ray diffraction method is preferably 0.3360 nm or less.
- the artificial graphite particles themselves in the negative electrode material also have a large amount of lithium insertion / extraction per mass, that is, the weight energy density of the negative electrode material also increases.
- expansion and contraction associated with insertion / extraction of lithium into / from Si can be easily relaxed, and cycle life is improved.
- a ratio I D / I G (R value) with a peak intensity (peak height) I G of a peak in the range of 1620 cm ⁇ 1 is preferably 0.15 or more and 1.00 or less. More preferably, it is 0.20 or more and 1.00 or less, More preferably, it is 0.40 or more and 1.00 or less. If the R value is too small, it means that the surface of the artificial graphite particles is not sufficiently covered with the coating layer made of the carbonaceous material including the silicon-containing particles.
- the bond between the artificial graphite particles and the silicon-containing particles is not sufficient, and it is difficult to obtain the effect of imparting conductivity to the silicon-containing particles, and it is also due to the coating layer of the carbonaceous material. Since the effect of suppressing the surface reactivity of the silicon-containing particles and the effect of alleviating expansion and contraction are reduced, the cycle characteristics are liable to deteriorate.
- an R value that is too large indicates that the surface of the artificial graphite particles is covered with a large amount of amorphous carbon having a large initial irreversible capacity. Therefore, when the R value exceeds 1.00 and is large, the initial discharge efficiency tends to be low.
- a negative electrode material according to an embodiment of the present invention includes silicon-containing particles, artificial graphite particles, and a carbonaceous material, and at least a part of the silicon-containing particles, artificial graphite particles, and carbonaceous material is combined. It is preferable to form composite particles.
- the negative electrode material having such a configuration can be manufactured according to a known method.
- the negative electrode material can be obtained by a method including mixing silicon-containing particles, artificial graphite particles, and a precursor of a carbonaceous material, and heat-treating the obtained mixture to form the precursor into a carbonaceous material. .
- the mixture of silicon-containing particles, artificial graphite particles, and carbon precursor is obtained by, for example, melting a pitch which is one of carbon precursors, mixing the molten pitch and silicon-containing particles in an inert atmosphere, and then mixing the mixture. And mixing the pulverized product with the artificial graphite particles; mixing the silicon-containing particles and the artificial graphite particles; and then mixing the silicon-containing particles and the mixture of the artificial graphite particles with the carbon precursor to obtain a mechanochemical Or by dissolving the carbon precursor with a solvent, adding and mixing silicon-containing particles and artificial graphite particles in the liquid phase, and then grinding.
- a known device such as a hybridizer (registered trademark) manufactured by Nara Machinery can be used.
- pulverization and mixing can be used for pulverization and mixing, but a method that does not increase the degree of oxidation of silicon-containing particles.
- a means for pulverizing mainly by impact such as a rod mill and a hammer mill, tends to transmit the impact force preferentially to the large particle size particles and not to the small particle size particles.
- Means for pulverizing mainly by impact and shear such as a pin mill and a rotary cutter mill, tend to transmit shear force preferentially to large particle size particles and not to small particle size particles.
- the negative electrode material according to the present invention can be obtained by using such an apparatus and pulverizing and mixing without proceeding the oxidation of the silicon-containing particles.
- the non-oxidizing atmosphere include an atmosphere filled with an inert gas such as argon gas or nitrogen gas.
- the heat treatment for forming the carbon precursor into the carbonaceous material is preferably performed at a temperature of 200 ° C. or higher and 2000 ° C. or lower, more preferably 500 ° C. or higher and 1500 ° C. or lower, and particularly preferably 600 ° C. or higher and 1200 ° C. or lower.
- the carbonaceous material coats the silicon-containing particles and / or the artificial graphite particles, and the carbonaceous material is formed between the silicon-containing particles, between the artificial graphite particles, and between the silicon-containing particles and the artificial graphite particles. It is possible to adopt a form in which the gaps are inserted and connected.
- the heat treatment is preferably performed in a non-oxidizing atmosphere.
- the non-oxidizing atmosphere include an atmosphere filled with an inert gas such as argon gas or nitrogen gas. Since it may be agglomerated by fusion by heat treatment, it is preferable to crush in order to use the heat-treated product as an electrode active material.
- a pulverizer using an impact force such as a hammer, a jet mill using collision between objects to be crushed, and the like are preferable.
- the negative electrode paste according to an embodiment of the present invention includes the negative electrode material, a binder, a solvent, and a conductive aid as necessary.
- This negative electrode paste can be obtained, for example, by kneading the negative electrode material, a binder, a solvent, and a conductive additive as necessary.
- the negative electrode paste can be formed into a sheet shape or a pellet shape.
- the binder is not particularly limited, and examples thereof include polyethylene, polypropylene, ethylene propylene terpolymer, butadiene rubber, styrene butadiene rubber, butyl rubber, acrylic rubber, and a polymer compound having high ionic conductivity.
- examples of the polymer compound having a large ionic conductivity include polyvinylidene fluoride, polyethylene oxide, polyepichlorohydrin, polyphasphazene, polyacrylonitrile and the like.
- the amount of the binder is preferably 0.5 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the negative electrode material.
- the conductive auxiliary agent is not particularly limited as long as it has a function of imparting conductivity and electrode stability to the electrode (buffering action against volume change in insertion / extraction of lithium ions).
- carbon nanotubes, carbon nanofibers, vapor grown carbon fibers for example, “VGCF (registered trademark)” manufactured by Showa Denko KK
- conductive carbon for example, “DENKA BLACK (registered trademark)” manufactured by Denki Kagaku Kogyo Co., Ltd., “Super C65” manufactured by TIMCAL, “Super C45” manufactured by TIMCAL, and “KS6L” manufactured by TIMCAL).
- the amount of the conductive auxiliary is preferably 10 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the negative electrode material.
- the solvent is not particularly limited and includes N-methyl-2-pyrrolidone, dimethylformamide, isopropanol, water and the like.
- a thickener it is preferable to use a thickener together. The amount of the solvent is adjusted so that the viscosity of the paste can be easily applied to the current collector.
- a negative electrode sheet according to an embodiment of the present invention includes a current collector and an electrode layer that covers the current collector.
- the current collector include nickel foil, copper foil, nickel mesh, or copper mesh.
- the electrode layer contains a binder and the negative electrode material.
- the electrode layer can be obtained, for example, by applying the paste and drying it.
- the method for applying the paste is not particularly limited.
- the thickness of the electrode layer is usually 50 to 200 ⁇ m. If the electrode layer becomes too thick, the negative electrode sheet may not be accommodated in a standardized battery container.
- the thickness of the electrode layer can be adjusted by the amount of paste applied. It can also be adjusted by drying the paste and then press molding. Examples of the pressure molding method include molding methods such as roll pressing and press pressing.
- the pressure during press molding is preferably (about 1 to 5 ton / cm 2 ).
- the electrode density of the negative electrode sheet can be calculated as follows. That is, the negative electrode sheet after pressing is punched into a circular shape having a diameter of 16 mm, and its mass is measured. Further, the thickness of the electrode is measured. From this, the mass and thickness of the electrode layer can be determined by subtracting the mass and thickness of the current collector foil separately measured, and the electrode density is calculated based on the values.
- a lithium ion battery according to an embodiment of the present invention includes at least one selected from the group consisting of a non-aqueous electrolyte and a non-aqueous polymer electrolyte, a positive electrode sheet, and the negative electrode sheet.
- the positive electrode sheet used in the present invention those conventionally used for lithium ion batteries, specifically, a sheet containing a positive electrode active material can be used.
- the positive electrode active material include LiNiO 2 , LiCoO 2 , LiMn 2 O 4 , LiNi 0.34 Mn 0.33 Co 0.33 O 2 , and LiFePO 4 .
- the non-aqueous electrolyte and non-aqueous polymer electrolyte used for the lithium ion battery are not particularly limited.
- lithium salts such as LiClO 4 , LiPF 6 , LiAsF 6 , LiBF 4 , LiSO 3 CF 3 , CH 3 SO 3 Li, CF 3 SO 3 Li can be converted into ethylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, propylene.
- Organic electrolytes dissolved in non-aqueous solvents such as carbonate, butylene carbonate, acetonitrile, propyronitrile, dimethoxyethane, tetrahydrofuran, and ⁇ -butyrolactone; polyethylene oxide, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, etc.
- non-aqueous solvents such as carbonate, butylene carbonate, acetonitrile, propyronitrile, dimethoxyethane, tetrahydrofuran, and ⁇ -butyrolactone
- polyethylene oxide polyacrylonitrile
- polyvinylidene fluoride polymethyl methacrylate
- a small amount of a substance that causes a decomposition reaction when the lithium ion battery is initially charged may be added to the electrolytic solution.
- the substance include vinylene carbonate (VC), biphenyl, propane sultone (PS), fluoroethylene carbonate (FEC), ethylene sultone (ES), and the like.
- VC vinylene carbonate
- PS propane sultone
- FEC fluoroethylene carbonate
- ES ethylene sultone
- 0.01 mass% or more and 50 mass% or less are preferable.
- a separator can be provided between the positive electrode sheet and the negative electrode sheet.
- the separator include non-woven fabrics, cloths, microporous films, or combinations thereof, which are mainly composed of polyolefins such as polyethylene and polypropylene.
- the lithium ion battery of the present invention is powered by a power source of an electronic device such as a mobile phone, a portable personal computer, or a personal digital assistant; a power source of an electric motor such as an electric drill, a vacuum cleaner or an electric vehicle; a fuel cell, solar power generation, wind power generation, etc. It can be used for storing the obtained electric power.
- a power source of an electronic device such as a mobile phone, a portable personal computer, or a personal digital assistant
- a power source of an electric motor such as an electric drill, a vacuum cleaner or an electric vehicle
- a fuel cell solar power generation, wind power generation, etc. It can be used for storing the obtained electric power.
- the carbon material is passed through a 106 ⁇ m filter to remove fine dust and purified, and 0.1 g of the sample is added to 20 ml of ion-exchanged water and uniformly added by adding 0.1 to 0.5% by mass of a surfactant.
- the sample solution for measurement was prepared by dispersing. Dispersion was performed by using an ultrasonic cleaner UT-105S (manufactured by Sharp Manufacturing System) for 5 minutes. The obtained sample solution for measurement was put into a flow particle image analyzer FPIA-3000 (manufactured by Sysmex Corporation), and image analysis of particles was performed on 10,000 particles in the LPF mode. The median circularity was defined as the average circularity.
- Styrene butadiene rubber SBR
- CMC carboxymethyl cellulose
- the negative electrode sheet is evaluated in advance for the discharge amount per weight of the active material in a half cell of the counter electrode Li, and the negative electrode with respect to the capacity (Q C ) of the positive electrode sheet
- the capacity of the negative electrode sheet was finely adjusted so that the ratio of the capacity (Q A ) of the sheet was 1.2 and a constant value.
- the electrolytic solution is a solvent in which ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate are mixed at a volume ratio of 3: 5: 2, and 1% by mass of vinylene carbonate (VC) and 30% of fluoroethylene carbonate (FEC).
- VC vinylene carbonate
- FEC fluoroethylene carbonate
- Example 1 A crude oil produced in Liaoningzhou, China (API28, wax content 17% by mass, sulfur content 0.66% by mass) was distilled at atmospheric pressure, using a sufficient amount of Y-type zeolite catalyst for heavy distillate, 510 Fluidized bed catalytic cracking was performed at °C and normal pressure. The solid content of the catalyst and the like was centrifuged until the obtained oil became clear to obtain a decant oil. This oil was put into a small delayed coking process. The drum inlet temperature was maintained at 505 ° C. and the drum internal pressure was maintained at 600 kPa (6 kgf / cm 2 ) for 10 hours, and then cooled with water to obtain a black lump.
- API28 wax content 17% by mass, sulfur content 0.66% by mass
- the resulting black mass was crushed with a hammer to a maximum of about 5 cm and then dried at 200 ° C. in a kiln. This was designated as coke 1.
- the coke 1 was pulverized with a bantam mill manufactured by Hosokawa Micron, and then coarse powder was cut using a sieve having an opening of 45 ⁇ m.
- the pulverized coke 1 was further pulverized by a jet mill manufactured by Seishin Corporation.
- This powder coke 1 was filled in a graphite crucible and subjected to heat treatment for 1 week in an Atchison furnace so that the maximum temperature reached about 3300 ° C., and non-flaky artificial graphite particles (B1) were obtained.
- the graphite crucible is provided with a plurality of vent holes.
- Table 1 shows various physical properties of the obtained non-flaky artificial graphite particles (B1). D50 is 6.4 ⁇ m, BET specific surface area is 6.1 m 2 / g, d002 is 0.3357 nm, Lc is 104 nm, total pore volume is 32.0 ⁇ L / g, average circularity is 0.88, orientation I 110 / I 004 was 0.28.
- This powder coke 2 was filled in a graphite crucible and subjected to heat treatment for 1 week in an Atchison furnace so that the maximum temperature reached about 3300 ° C., thereby obtaining non-flaky artificial graphite particles (B2). .
- the graphite crucible is provided with a plurality of vent holes.
- Various physical properties of the obtained non-flaky artificial graphite particles (B2) are shown in Table 1.
- D50 is 12.2 ⁇ m
- BET specific surface area is 2.5 m 2 / g
- d002 is 0.3357 nm
- Lc is 108 nm
- total pore volume is 10.5 ⁇ L / g
- average circularity is 0.89
- orientation I 110 / I 004 was 0.11.
- Example 3 The powder coke 2 described in Example 2 was filled in a graphite crucible, and was heated in an Atchison furnace for 1 week so that the maximum temperature reached about 3300 ° C.
- the particles were non-flaky artificial graphite particles (B3 )
- Table 1 shows various physical properties of the obtained non-flaky artificial graphite particles (B3).
- D50 is 12.2 ⁇ m
- BET specific surface area is 1.0 m 2 / g
- d002 is 0.3357 nm
- Lc is 108 nm
- total pore volume is 5.0 ⁇ L / g
- average circularity is 0.89
- orientation I 110 / I 004 was 0.11.
- Comparative Example 1 For the coke 1 described in Example 1, a rotary kiln (electric heater external heating type, aluminum oxide SSA-S, ⁇ 120 mm inner tube) with an outer wall temperature at the center of the inner tube set to 1450 ° C. was used, and the residence time was 15 minutes. The coke was calcined by adjusting the feed amount and the inclination angle so as to be, and heating was performed, whereby calcined coke 1 was obtained. The calcined coke 1 was pulverized with a bantam mill manufactured by Hosokawa Micron, and then coarse powder was cut using a sieve having an opening of 45 ⁇ m.
- a rotary kiln electric heater external heating type, aluminum oxide SSA-S, ⁇ 120 mm inner tube
- D50 is 19.3 ⁇ m
- BET specific surface area is 2.1 m 2 / g
- d002 is 0.3357 nm
- Lc is 105 nm
- total pore volume is 9.2 ⁇ L / g
- average circularity is 0.83
- orientation I 110 / I004 was 0.04. Then, it replaced with the artificial graphite particle (B1) of Example 1, and obtained the composite material (4) by the method similar to Example 1 except having used the artificial graphite particle (B4).
- Table 2 shows the results of evaluating the powder physical properties and battery characteristics of this composite material (4).
- Comparative Example 2 Table 1 shows the results of measuring various physical properties of spherical natural graphite (B5) as graphite particles. D50 16.8 ⁇ m, d002 0.3355 nm, BET specific surface area 1.8 m 2 / g, Lc 109 nm, total pore volume 0.13 ⁇ L / g, average circularity 0.92, orientation I 110 / I 004 was 0.29.
- a composite material (5) was obtained in the same manner as in Example 1 except that spherical natural graphite particles (B5) were used instead of the artificial graphite particles (B1) of Example 1. Table 2 shows the results of evaluating the powder physical properties and battery characteristics of this composite material (5).
- Comparative Example 3 Table 1 shows the results of measuring various physical properties of mesophase spherical graphite (B6) as graphite particles. D50 is 16.2 ⁇ m, d002 is 0.3365 nm, BET specific surface area is 1.5 m 2 / g, Lc is 60 nm, total pore volume is 9.3 ⁇ L / g, average circularity is 0.97, orientation I 110 / I 004 was 0.65.
- a composite material (6) was obtained in the same manner as in Example 1 except that mesophase spherical graphite (B6) was used in place of the artificial graphite particles (B1) of Example 1. Table 2 shows the results of evaluating the powder physical properties and battery characteristics of this composite material (6).
- Comparative Example 4 Table 1 shows the results of measuring various physical properties of the massive graphite (B7) as the graphite particles. D50 is 3.0 ⁇ m, d002 is 0.3365 nm, BET specific surface area is 1.4 m 2 / g, Lc is 65 nm, total pore volume is 11.8 ⁇ L / g, average circularity is 0.90, orientation I 110 / I 004 was 0.38.
- a composite material (7) was obtained in the same manner as in Example 1 except that lump graphite (B7) was used instead of the artificial graphite particles (B1) of Example 1. Table 2 shows the results of evaluating the powder physical properties and battery characteristics of this composite material (7).
- Comparative Example 5 Table 1 shows the results of measuring various physical properties of the small particle size massive graphite (B8) as the graphite particles. D50: 6.2 ⁇ m, d002: 0.3363 nm, BET specific surface area: 3.2 m 2 / g, Lc: 65 nm, total pore volume: 25.0 ⁇ L / g, average circularity: 0.90, orientation I 110 / I 004 was 0.48.
- a composite material (8) was obtained in the same manner as in Example 1 except that small-grained massive graphite (B8) was used instead of the artificial graphite particles (B1) in Example 1. Table 2 shows the results of evaluating the powder physical properties and battery characteristics of this composite material (8).
- Comparative Example 6 In place of the silicon-containing particles of Example 2, the number-based average particle size of the primary particle size is 500 nm, the BET specific surface area is 5.2 m 2 / g, and the oxygen content in the Si fine particles determined by ICP (inductively coupled plasma) is 2 A composite material (9) was obtained in the same manner as in Example 2 except that the silicon-containing particles (A2) of .6% by mass were used. Table 2 shows the results of evaluating the powder physical properties and battery characteristics of this composite material (9).
- Comparative Example 7 In Example 2, petroleum pitch was not added, that is, silicon-containing particles and artificial graphite particles (B2) were simply mixed to obtain a mixed material (10). Table 2 shows the results of evaluating the powder physical properties and battery characteristics of this mixed material (10).
- Comparative Example 8 In Example 2, a mixture obtained by uniformly heating and melting and mixing silicon-containing particles with 24.0 parts by mass of petroleum pitch and 78.0 parts by mass of artificial graphite particles (B2) were fired after mixing. The fired product was repeatedly pulverized with a rotary cutter mill, and the pulverized product was repeatedly pulverized until the specific surface area of the sieving recovered product was 10.1 m 2 / g to obtain a composite material (11). Table 2 shows the results of evaluating the powder physical properties and battery characteristics of this composite material (11).
- a negative electrode material having a large discharge amount per mass can be obtained. Further, by using the negative electrode material in the present invention, a lithium ion battery having a large capacity, excellent initial efficiency and charge / discharge cycle characteristics can be produced.
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Composite Materials (AREA)
- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Silicon Compounds (AREA)
- Carbon And Carbon Compounds (AREA)
Abstract
Description
例えば、特許文献1には、ガス中蒸発法により形成されたSi超微粒子を黒鉛粒子の表面にメカノケミカル処理により固定し、石油メソフェーズピッチを混合した後炭化した負極材が提案されている。
特許文献1でも同様であり、メカノケミカル処理を行っていたとしても、Si超微粒子自身の表面活性制御を行っていないために、Si超微粒子自体は単粒子分散した状態で黒鉛表面に付着しているのではなく、凝集粒子として付着しているので、リチウムイオンの挿入・脱離(吸蔵・放出)に伴う膨張収縮が凝集粒子状態で起こって複合構造が破壊されてしまい、サイクル寿命の改善は十分でない。
このように、リチウムと合金形成可能な金属元素としてSiを負極材料に用いた時の充放電サイクル寿命の改善は未だ十分ではなく、一層の改善が求められている。
[1] ケイ素含有粒子と人造黒鉛粒子と炭素質材料とを含むリチウムイオン電池用負極材であって、前記のケイ素含有粒子と人造黒鉛粒子と炭素質材料はその少なくとも一部が複合化している複合粒子であり、
前記ケイ素含有粒子は、粒子表面にSiOx層(0<x≦2)を有するケイ素粒子であって、酸素含有率が1.0質量%以上18.0質量%以下であり、200nm以下の一次粒子径を有する粒子を主成分とするものであり、
前記人造黒鉛粒子は、レーザー回折法による体積基準累積粒度分布における50%累積時の粒子径D50が1.0μm以上15.0μm以下の非鱗片状人造黒鉛粒子である、リチウムイオン電池用負極材。
[2] 前記人造黒鉛粒子は、粉末XRD測定から得られる黒鉛結晶の(110)面のピーク強度I110と(004)面のピーク強度I004の比I110/I004が0.10以上0.35以下、X線回折法による(002)面の平均面間隔d002が0.3360nm以下、平均円形度が0.80以上0.95以下、窒素ガス吸着法によって測定される直径0.4μm以下の細孔の全細孔容積が5.0μL/g以上40.0μL/g以下である非鱗片状人造黒鉛粒子であって、前記人造黒鉛粒子の断面において観察される光学組織について、面積の小さな組織から面積を累積し、その累計面積が全光学組織面積の60%の面積となるときの光学組織の面積をSOPとし、アスペクト比の小さな組織から組織の数を数え組織全体の数の60%番目の組織におけるアスペクト比をAROP、レーザー回折法による体積基準累積粒度分布における50%累積時の粒子径をD50としたとき、
1.5≦AROP≦6.0 および
0.2×D50≦(SOP×AROP)1/2<2×D50
の関係を有するものである、前記1に記載のリチウムイオン電池用負極材。
[3] 前記人造黒鉛粒子は、、レーザー回折法による体積基準累積粒度分布における50%累積時の粒子径D50が10.0μm以下である、前記1または2に記載のリチウムイオン電池用負極材。
[4] 前記ケイ素含有粒子の含有量が、前記人造黒鉛粒子を100質量部としたとき5.0質量部以上30.0質量部以下である、前記1乃至3のいずれか1項に記載のリチウムイオン電池用負極材。
[5] 前記炭素質材料が、石油ピッチまたは石炭ピッチを熱処理してなるものである、前記1乃至4のいずれか1項に記載のリチウムイオン電池用負極材。
[6] 前記炭素質材料の量が、前記のケイ素含有粒子と人造黒鉛粒子と炭素質材料との合計に対し2.0質量%以上40.0質量%以下である、前記1乃至5のいずれか1項に記載のリチウムイオン電池用負極材。
[7] 前記リチウムイオン電池用負極材は、、レーザー回折法による体積基準累積粒度分布における50%累積時の粒子径D50が2.0μm以上18.0μm以下である、前記1乃至6のいずれか1項に記載のリチウムイオン電池用負極材。
[8] 前記リチウムイオン電池用負極材は、BET比表面積が2.0m2/g以上10.0m2/g以下である、前記1乃至7のいずれか1項に記載のリチウムイオン電池用負極材。
[9] 前記リチウムイオン電池用負極材は、X線回折法による前記黒鉛粒子の(002)面の平均面間隔d002が0.3360nm以下である前記1乃至8のいずれか1項に記載のリチウムイオン電池用負極材。
[10] 前記リチウムイオン電池用負極材は、顕微ラマン分光測定器で前記複合粒子を測定した際ラマン分光スペクトルで測定される1300~1400cm-1の範囲にあるピークのピーク強度IDと1580~1620cm-1の範囲にあるピークのピーク強度IGとの比ID/IG(R値)が0.15以上1.00以下である、前記1乃至9のいずれか1項に記載のリチウムイオン電池用負極材。
[11] 前記1乃至10のいずれか1項に記載のリチウムイオン電池用負極材とバインダーとを含むペースト。
[12] 前記11に記載のペーストの成形体を含むリチウムイオン電池用負極。
[13] 前記12に記載の負極を構成要素として含むリチウムイオン電池。
ケイ素含有粒子は、粒子表層がSiOx(0<x≦2)を含有するものである。表層以外の部分(コア)は、元素状ケイ素からなっていてもよいし、SiOx(0<x≦2)からなっていてもよい。SiOxを含有する表層の平均厚さは0.5nm以上10.0nm以下が好ましい。SiOxを含有する表層の平均厚さが0.5nm以上であると、空気や酸化性ガスによる酸化を抑制することができる。また、SiOxを含有する表層の平均厚さが10.0nm以下であると、初期サイクル時の不可逆容量の増加を抑制することができる。この平均厚さはTEM写真により測定することができる。
Dav=6/(ρ×Ssa)
Dav:粒子が稠密な球であると仮定したときの直径
Ssa:ケイ素含有粒子のBET比表面積(m2/g)
ρ:ケイ素の真密度(理論値としての2.33g/cm3)
直径Davがこの範囲にあることにより、Si結晶相へのLiの挿入に伴う体積歪を緩和することができ、Siを負極活物質に用いたときの最大の欠点である充放電に伴う膨張収縮を抑制することができる。
黒鉛粒子は、組織が入り組んでいると硬いため、電極密度を向上させるためには大きな組織を持つ黒鉛粒子とすることが好ましい。黒鉛粒子中に観察される組織としては、結晶が発達し黒鉛網面が整うことにより光学的異方性を示す組織と、結晶が未発達もしくはハードカーボンのような結晶の乱れが大きいことにより光学的等方性を示す組織があることは古くから知られている。これら組織の観察について、X線回折法を使用して、結晶子のサイズを測ることも可能であるが、例えば“最新の炭素材料実験技術(分析・解析偏)炭素材料学会偏(2001年),出版:サイペック株式会社,1~8頁”等に記載されている偏光顕微鏡観察法により観察することができる。本明細書においては、偏光顕微鏡のクロスニコル状態で試料を観察した場合に黒色以外の色(鋭敏色検板を使用している場合は鋭敏色以外の色)が観察される個々の領域(ドメイン)を光学組織と呼ぶ。
1.5≦AROP≦6.0 および
0.2×D50≦(SOP×AROP)1/2<2×D50
[偏光顕微鏡観察試料作製]
本発明における「炭素材料の断面」は以下のようにして作製する。
内容積30cm3のプラスチック製サンプル容器の底に両面テープを貼り、その上にスパチュラ2杯ほど(2g程度)の観察用サンプルを乗せる。冷間埋込樹脂(商品名:冷間埋込樹脂#105、製造会社:ジャパンコンポジット(株)、販売会社:丸本ストルアス(株))に硬化剤(商品名:硬化剤(M剤)、製造会社:日本油脂(株)、販売会社:丸本ストルアス(株))を加え、30秒練る。得られた混合物(5ml程度)を前記サンプル容器に高さ約1cmになるまでゆっくりと流し入れ、1日静置して凝固させる。次に凝固したサンプルを取り出し、両面テープを剥がす。そして、研磨板回転式の研磨機を用いて、測定する面を研磨する。
観察は200倍で行う。偏光顕微鏡で観察した画像は、OLYMPUS製CAMEDIA(登録商標) C-5050 ZOOMデジタルカメラをアタッチメントで偏光顕微鏡に接続し、撮影する。シャッタータイムは1.6秒で行う。撮影データのうち、1200ピクセル×1600ピクセルの画像を解析対象とする。これは480μm×640μmの視野に相当する。解析に使用する画像は多いほど好ましく、40枚以上で測定誤差が小さくなる。画像解析はImageJ(アメリカ国立衛生研究所製)を用いて,青色部,黄色部,赤色部,黒色部を判定した。
各色のImageJ使用時に各色を定義したパラメーターは以下の通りである。
また、鱗片状になると嵩密度が小さくなるので扱いにくくなり、電極作製のためにスラリーにする際に溶媒との親和性が低く、電極の剥離強度が弱くなることもある。
この粒子の配向性は、先述の光学組織とも関わりがある。
なお、平均円形度はFPIA-3000(シスメックス社製)を用いてLPFモードで10000個以上の粒子に対して解析された円形度の頻度分布により算出される。ここで円形度とは、観測された粒子像の面積と同面積を有する円の周長を粒子像の周長で割ったものであり、1に近い程真円に近い。粒子像の面積をS、周長をLとすると、以下の式で表すことができる。
円形度=(4πS)1/2/L
人造黒鉛粒子の結晶子のC軸方向の厚みLcとしては50nm以上1000nm以下が、重量エネルギー密度やつぶれ性の観点から好ましい。
d002及びLcは、既知の方法により粉末X線回折(XRD)法を用いて測定することができる(野田稲吉、稲垣道夫、日本学術振興会、第117委員会試料、117-71-A-1(1963)、稲垣道夫他、日本学術振興会、第117委員会試料、117-121-C-5(1972)、稲垣道夫、「炭素」、1963、No.36、25-34頁参照)。
ラマンスペクトルは、例えば日本分光社製NRS-5100を用いて、付属の顕微鏡で観察しながら、観察することによって、測定することが可能である。
本発明の好ましい実施態様における人造黒鉛粒子は、熱履歴が1000℃以下のコークスを粉砕した粒子を加熱することにより製造することができる。
コークスの原料としては、例えば、石油ピッチ、石炭ピッチ、石炭ピッチコークス、石油コークス及びこれらの混合物を用いることができる。これらの中でも、特定の条件下でディレイドコーキングを行ったものが望ましい。
乾式で粉砕を行う場合、粉砕時にコークスに水が含まれていると粉砕性が著しく低下するので、100~1000℃程度で乾燥させることが好ましい。より好ましくは100~500℃である。コークスが高い熱履歴を有していると圧砕強度が強くなり粉砕性が悪くなり、また結晶の異方性が発達してしまうので劈開性が強くなり鱗片状の粉末になり易くなる。粉砕する手法に特に制限はなく、公知のジェットミル、ハンマーミル、ローラーミル、ピンミル、振動ミル等が用いて行うことができる。
粉砕は、D50が1.0μm以上15.0μm以下となるように行うことが好ましい。より好ましくは1.0μm以上10.0μm以下、さらに好ましくは1.0μm以上7.0μm以下となるように粉砕する。
黒鉛化後に粉砕されていない黒鉛粒子を活物質として用いて電極を作製すると、電極圧縮時に電極内部で活物質が均一に分布しやすくなり、また隣接する粒子との接触も安定し、よって繰り返し充放電に一層優れた電池とすることができる。
本発明の好ましい実施態様における炭素質材料は、前記人造黒鉛粒子とは異なるものであって、炭素原子により形成される結晶の発達が低い炭素材料であり、ラマン散乱による1360cm-1近傍にピークを持つ。
炭素質材料は、例えば、炭素前駆体を炭素化することによって製造することができる。前記炭素前駆体は、特に限定されないが、熱重質油、熱分解油、ストレートアスファルト、ブローンアスファルト、エチレン製造時に副生するタールまたは石油ピッチなどの石油由来物質、石炭乾留時に生成するコールタール、コールタールの低沸点成分を蒸留除去した重質成分、コールタールピッチ(石炭ピッチ)などの石炭由来物質が好ましく、特に石油系ピッチまたは石炭系ピッチが好ましい。ピッチは複数の多環芳香族化合物の混合物である。ピッチを用いると、高い炭素化率で、不純物の少ない炭素質材料を製造できる。ピッチは酸素含有率が少ないので、ケイ素含有粒子を炭素質材料で被覆する際に、ケイ素含有粒子が酸化されにくい。
残炭率は以下の方法で決定される。固体状のピッチを乳鉢等で粉砕し、粉砕物を窒素ガス流通下で質量熱分析する。1100℃における質量の仕込み質量に対する割合を残炭率と定義する。残炭率はJIS K2425において炭化温度1100℃にて測定される固定炭素量に相当する。
炭素質材料の量が2.0質量%未満であると、ケイ素含有粒子と人造黒鉛粒子との結合が十分でなく、また、ケイ素含有粒子の表面を炭素質材料で覆うことができないため、Siに導電性が付与されにくくなったり、Siの表面反応性を抑制する効果や膨張収縮を緩和する効果が低くサイクル特性が低下する傾向がある。一方、40.0質量%を超えると、炭素質材料量に依存して初期効率が低くなる傾向がある。
本発明の一実施形態に係る負極材は、ケイ素含有粒子と人造黒鉛粒子と炭素質材料とを含んでなり、前記のケイ素含有粒子と人造黒鉛粒子と炭素質材料は少なくともその一部が互いに複合化して複合粒子を形成していることが好ましい。複合化とは、例えば、ケイ素含有粒子と人造黒鉛粒子とが炭素質材料により固定されて結合して複合粒子を形成している状態や、あるいはケイ素含有粒子及び/または人造黒鉛粒子が炭素質材料により被覆されて複合粒子を形成している状態を挙げることができる。本発明においてはケイ素含有粒子が炭素質材料によって完全に被覆され、Siが露出していない状態となっていることが好ましく、その中でもケイ素含有粒子と人造黒鉛粒子とが炭素質材料を介して連結し、その全体が炭素質材料により被覆されて複合粒子を形成している状態、及びケイ素含有粒子と人造黒鉛粒子とが直接接触し、その全体が炭素質材料により被覆されて複合粒子を形成している状態が好ましい。負極材として電池に用いた際に、ケイ素含有粒子の表面が露出しないことにより電解液分解反応が抑制されクーロン効率を高く維持することができ、炭素質材料を介して人造黒鉛粒子及びケイ素含有粒子が連結することによりそれぞれの間の導電性を高めることができ、またケイ素含有粒子が炭素質材料により被覆されることによりその膨張及び収縮に伴う体積変化を緩衝することができる。
本発明の一実施形態に係る負極材は、ケイ素含有粒子と人造黒鉛粒子と炭素質材料とを含んでなり、前記のケイ素含有粒子と人造黒鉛粒子と炭素質材料はその少なくとも一部が複合化している複合粒子を形成していることが好ましい。このような構成を有する負極材は公知の方法に従って製造することができる。
例えば、ケイ素含有粒子と人造黒鉛粒子と炭素質材料の前駆体とを混ぜ合わせ、得られた混合物を熱処理して前記前駆体を炭素質材料に成すことを含む方法によって負極材を得ることができる。
ケイ素含有粒子と人造黒鉛粒子と炭素前駆体との混合物は、例えば、炭素前駆体の一つであるピッチを溶融させ、該溶融ピッチとケイ素含有粒子とを不活性雰囲気にて混合し、該混合物を粉砕し、該粉砕物を人造黒鉛粒子と混合することによって;ケイ素含有粒子と人造黒鉛粒子とを混合し、次いでケイ素含有粒子及び人造黒鉛粒子の混合物と炭素前駆体とを混合してメカノケミカル処理を行うことによって;または炭素前駆体を溶媒により溶解し、該液相にてケイ素含有粒子と人造黒鉛粒子を添加混合し、次いで粉砕することによって;得ることができる。メカノケミカル処理は、例えば、奈良機械製ハイブリダイザー(登録商標)などの公知の装置を用いることができる。
本発明の一実施形態に係る負極用ペーストは、前記負極材とバインダーと溶媒と必要に応じて導電助剤などを含むものである。この負極用ペーストは、例えば、前記負極材とバインダーと溶媒と必要に応じて導電助剤などを混練することによって得られる。負極用ペーストは、シート状、ペレット状などの形状に成形することができる。
本発明の一実施形態に係る負極シートは、集電体と、該集電体を被覆する電極層とを有するものである。
集電体としては、例えば、ニッケル箔、銅箔、ニッケルメッシュまたは銅メッシュなどが挙げられる。
電極層は、バインダーと前記の負極材とを含有するものである。電極層は、例えば、前記のペーストを塗布し乾燥させることによって得ることができる。ペーストの塗布方法は特に制限されない。電極層の厚さは、通常、50~200μmである。電極層が厚くなりすぎると、規格化された電池容器に負極シートを収容できなくなることがある。電極層の厚さは、ペーストの塗布量によって調整できる。また、ペーストを乾燥させた後、加圧成形することによっても調整することができる。加圧成形法としては、ロール加圧、プレス加圧などの成形法が挙げられる。プレス成形するときの圧力は、好ましくは(1~5ton/cm2程度)である。
負極シートの電極密度は次のようにして計算することができる。すなわち、プレス後の負極シートを直径16mmの円形状に打ち抜き、その質量を測定する。また、電極の厚みを測定する。そこから別途測定しておいた集電箔の質量と厚みを引き算すれば電極層の質量と厚みを知ることができ、その値を元に電極密度を計算する。
本発明の一実施形態に係るリチウムイオン電池は、非水系電解液及び非水系ポリマー電解質からなる群から選ばれる少なくとも一つ、正極シート、及び前記負極シートを有するものである。
本発明に用いられる正極シートには、リチウムイオン電池に従来から使われていたもの、具体的には正極活物質を含んでなるシートを用いることができる。正極活物質としては、LiNiO2、LiCoO2、LiMn2O4、LiNi0.34Mn0.33Co0.33O2、LiFePO4などが挙げられる。
(1)ケイ素含有粒子
下式によって定義される直径Dav:50nm
dav=6/(ρ×BET)
微粒子が平均直径davの稠密な球であると仮定
BET:窒素吸着によるBET比表面積(51.5m2/g)
ρ:ケイ素粒子の真密度(理論値としての2.33g/cm3);
ICP(誘導結合プラズマ)により定量したSi微粒子に含まれる酸素含有率:5.8質量%;
また、電子顕微鏡にて倍率10万倍により観察し、任意に一次粒子200個を抽出して画像解析により定量化した結果、数基準累積分布において50%径は48nmであり、90%径は182nmであった。
(2)ピッチ
石油ピッチ(軟化点220℃)。この石油ピッチについて、窒素ガス流通下の熱分析により1100℃における残炭率を測定したところ、52%であった。
また、JIS K2425に記載されている方法またはそれに準じた方法で測定した石油ピッチのQI含量は0.62%、TI含量は48.9%であった。
(粒子径)
粉体を極小型スパーテル2杯分、及び非イオン性界面活性剤(TRITON(登録商標)-X;Roche Applied Science製)2滴を水50mlに添加し、3分間超音波分散させた。この分散液をセイシン企業社製レーザー回折式粒度分布測定器(LMS-2000e)に投入し、体積基準累積粒度分布を測定した。
日本分光株式会社製レーザーラマン分光測定装置(NRS-3100)を用いて、励起波長532nm、入射スリット幅200μm、露光時間15秒、積算回数2回、回折格子600本/mmの条件で測定を行った。測定されたスペクトルから1360cm-1付近のピークの強度ID(非晶質成分由来)と1580cm-1付近のピークの強度IG(黒鉛成分由来)の比ID/IGを算出した。それをR値として黒鉛化度合いの指標とした。
Quantachrome製Surface Area & Pore Size Analyzer/NOVA 4200eにより、窒素ガスをプローブとして相対圧0.1、0.2、及び0.3のBET多点法により測定した。
炭素粉末試料をガラス製試料板(試料板窓18×20mm、深さ0.2mm)に充填し、以下のような条件で測定を行った。
XRD装置:Rigaku製SmartLab
X線種:Cu-Kα線
Kβ線除去方法:Niフィルター
X線出力:45kV、200mA
測定範囲:5.0~10.0deg.
スキャンスピード:10.0deg./min.
得られた波形に対し、平滑化、バックグラウンド除去、Kα2除去を行い、プロファイルフィッティングを行った。
粉末X線回折における002回折線から、面間隔d002及び結晶子のc軸方向の大きさLcを求めた。
また、(004)面のピーク強度I004と(110)面のピーク強度I110から配向性の指標となる強度比I110/I004を算出した。なお、各面のピークは以下の範囲のうち最大の強度のものをそれぞれのピークとして選択した。
(004)面:54.0~55.0deg.
(110)面:76.5~78.0deg
炭素材料を106μmのフィルターに通して微細なゴミを取り除いて精製し、その試料0.1gを20mlのイオン交換水中に添加し、界面活性剤0.1~0.5質量%加えることによって均一に分散させ、測定用試料溶液を調製した。分散は超音波洗浄機UT-105S(シャープマニファクチャリングシステム社製)を用い、5分間処理することにより行った。
得られた測定用試料溶液をフロー式粒子像分析装置FPIA-3000(シスメックス社製)に投入し、LPFモードで10000個の粒子に対して粒子の画像解析を行い、得られた各々の粒子の円形度の中央値を平均円形度とした。
炭素材料約5gをガラス製セルに秤量し、1kPa以下の減圧下300℃で約3時間乾燥して、水分等の吸着成分を除去した後、炭素材料の質量を測定した。その後、液体窒素冷却下における乾燥後の炭素材料の窒素ガスの吸着等温線をカンタクローム(Quantachrome)社製Autosorb-1で測定した。得られた吸着等温線のP/P0=0.992~0.995での測定点における窒素吸着量と乾燥後の炭素材料の質量から直径0.4μm以下の全細孔容積を求めた。
LiCoO2を90gと導電助剤としてカーボンブラック(TIMCAL社製)5g、及び結着材としてポリフッ化ビニリデン(PVdF)5gにN-メチル-ピロリドンを適宜加えながら攪拌・混合し、スラリー状の正極用ペーストを得た。
前記の正極用ペーストを厚さ20μmのアルミ箔上にロールコーターにより塗布し、乾燥させて正極用シートを得た。乾燥した電極はロールプレスにより密度を3.6g/cm3とし、電池評価用正極シートを得た。
バインダーとしてスチレンブタジエンゴム(SBR)及びカルボキシメチルセルロース(CMC)を用いた。具体的には、固形分比40%のSBRを分散した水溶液、及び、固形分CMC粉末を溶解した水溶液を得た。
導電助剤としてカーボンブラック及び気相成長法炭素繊維(VGCF(登録商標)-H,昭和電工株式会社製)を用意し、両者を3:2(質量比)で混合したものを混合導電助剤とした。
実施例及び比較例で製造した複合材料90質量部、混合導電助剤5質量部、CMC固形分2.5質量部となるようにCMC水溶液、SBR固形分2.5質量部となるようにSBR水溶液を混合し、これに粘度調整のための水を適量加え、自転・公転ミキサーにて混練し負極用ペーストを得た。
前記の負極用ペーストを厚み20μmの銅箔上にドクターブレードを用いて厚さ150μmとなるよう均一に塗布し、ホットプレートにて乾燥後、真空乾燥させて負極シートを得た。乾燥した電極は3ton/cm2の圧力にて一軸プレス機によりプレスして電池評価用負極シートを得た。
正極シートと負極シートを対向させてリチウムイオン電池を作製する際、両者の容量バランスを考慮する必要がある。すなわち、リチウムイオンを受け入れる側の負極が少な過ぎれば過剰なLiが負極側に析出してサイクル劣化の原因となり、逆に負極が多過ぎればサイクル特性は向上するものの負荷の小さい状態での充放電となるためエネルギー密度は低下する。これを防ぐため、正極シートは同一のものを使用しつつ、負極シートは対極Liのハーフセルにて事前に活物質重量当たりの放電量を評価しておき、正極シートの容量(QC)に対する負極シートの容量(QA)の比が1.2で一定値となるよう負極シートの容量を微調整した。
露点-80℃以下の乾燥アルゴンガス雰囲気に保ったグローブボックス内で下記の操作を実施した。
[二極セル]
上記負極シート及び正極シートを打ち抜いて面積20cm2の負極片及び正極片を得た。正極片のAl箔にAlタブを、負極片のCu箔にNiタブをそれぞれ取り付けた。ポリプロピレン製フィルム微多孔膜を負極片と正極片との間に挟み入れ、その状態でアルミラミネートにパックした。そして、それに電解液を注液した。その後、開口部を熱融着によって封止して評価用の電池を作製した。なお、電解液は、エチレンカーボネート、エチルメチルカーボネート、及びジエチルカーボネートが体積比で3:5:2の割合で混合した溶媒にビニレンカーボネート(VC)を1質量%、フルオロエチレンカーボネート(FEC)を30質量%混合し、さらにこれに電解質LiPF6を1mol/Lの濃度になるように溶解させて得られた液である。
[対極リチウムセル]
ポリプロピレン製のねじ込み式フタつきのセル(内径約18mm)内において、上記負極2と16mmφに打ち抜いた金属リチウム箔をセパレータ(ポリプロピレン製マイクロポーラスフィルム(セルガード2400))で挟み込んで積層し、電解液を加えて試験用セルとした。なお、電解液は、エチレンカーボネート、エチルメチルカーボネート、及びジエチルカーボネートが体積比で3:5:2の割合で混合した溶媒にフルオロエチレンカーボネート(FEC)を1質量%混合し、さらにこれに電解質LiPF6を1mol/Lの濃度になるように溶解させて得られた液である。
対極リチウムセルを用いて試験を行った。レストポテンシャルから0.005Vまで電流値0.1CでCC(コンスタントカレント:定電流)充電を行った。次に0.005VでCV(コンスタントボルト:定電圧)充電に切り替え、カットオフ電流値0.005Cで充電を行った。
上限電圧1.5VとしてCCモードで電流値0.1Cで放電を行った。
試験は25℃に設定した恒温槽内で行った。この際、初回放電時の容量を初期放電容量とした。また初回充放電時の電気量の比率、すなわち放電電気量/充電電気量を百分率で表した結果を初期クーロン効率とした。
二極セルを用いて試験を行った。0.2Cの電流値で5回の充放電を繰り返すエージングを行った後、次の方法で充放電サイクル試験を行った。
充電は、上限電圧4.2Vとして電流値1CのCC(コンスタントカレント)モード及びカットオフ電流0.05CのCV(コンスタントボルテージ)モードで行った。
放電は、下限電圧2.8Vとして電流値1CのCCモードで行った。
この充放電操作を1サイクルとして100サイクル行い、Nサイクル目の放電量維持率を次式で定義して計算した。
(Nサイクル後放電量維持率(%))=
(Nサイクル時放電容量)/(初回放電容量)×100
中国遼寧省産原油(API28、ワックス含有率17質量%、硫黄含有率0.66質量%)を常圧蒸留し、重質溜分に対して、十分な量のY型ゼオライト触媒を用い、510℃、常圧で流動床接触分解を行った。得られたオイルが澄明となるまで触媒等の固形分を遠心分離し、デカントオイルを得た。このオイルを小型ディレイドコーキングプロセスに投入した。ドラム入り口温度は505℃、ドラム内圧は600kPa(6kgf/cm2)に10時間維持した後、水冷して黒色塊を得た。得られた黒色塊を最大5cm程度になるように金槌で粉砕した後キルンにて200℃で乾燥を行った。これをコークス1とした。
このコークス1をホソカワミクロン製バンタムミルで粉砕し、その後45μmの目開きの篩を用いて粗粉をカットした。この粉砕後のコークス1をさらにセイシン企業製ジェットミルで粉砕した。次に、日清エンジニアリング製ターボクラシファイアーTC-15Nで気流分級し、粒径が1.0μm以下の粒子を実質的に含まない粉末コークス1(D50=6.3μm)を得た。
この粉末コークス1を黒鉛るつぼに充填し、アチソン炉にて最高到達温度が約3300℃となるように1週間かけて加熱処理を行い、非鱗片状の人造黒鉛粒子(B1)を得た。このとき、黒鉛るつぼには複数の通気孔が設けられている。得られた非鱗片状の人造黒鉛粒子(B1)の各種物性を表1に示す。D50が6.4μm、BET比表面積が6.1m2/g、d002が0.3357nm、Lcが104nm全細孔容積が32.0μL/g、平均円形度が0.88、配向性I110/I004が0.28であった。
次に、前記のケイ素含有粒子10.0質量部と前記の石油ピッチ11.5質量部をセパラブルフラスコに投入した。窒素ガスを流通させて不活性雰囲気を保ち、250℃まで昇温した。ミキサーを500rpmで回転させて撹拌し、ピッチとケイ素含有粒子とを均一に混合させた。これを冷却し固化させて混合物を得た。
この混合物に、前記の人造黒鉛粒子(B1)86.0質量部を加え、ロータリーカッターミルに投入し、窒素ガスを流通させて不活性雰囲気を保ちつつ25000rpmで高速撹拌し混合させた。
これを焼成炉に入れ、窒素ガス流通下で、150℃/hで1100℃まで上げ、1100℃にて1時間保持した。室温まで冷やし焼成炉から取り出しロータリーカッターミルで解砕後、45μm目開きの篩にて篩分した篩下を複合材料(1)として得た。
この複合材料(1)について、粉体物性及び電池特性を評価した結果を表2に示す。
実施例1記載のコークス1をホソカワミクロン製バンタムミルで粉砕し、その後45μmの目開きの篩を用いて粗粉をカットした。この粉砕後のコークス1をさらにセイシン企業製ジェットミルで粉砕した。次に、日清エンジニアリング製ターボクラシファイアーTC-15Nで気流分級し、粒径が1.0μm以下の粒子を実質的に含まない粉末コークス2(D50=12.0μm)を得た。
この粉末コークス2を黒鉛るつぼに充填し、アチソン炉にて最高到達温度が約3300℃となるように1週間かけて加熱処理を行い、粒子が非鱗片状の人造黒鉛粒子(B2)を得た。このとき、黒鉛るつぼには複数の通気孔が設けられている。得られた非鱗片状の人造黒鉛粒子(B2)の各種物性を表1に示す。D50が12.2μm、BET比表面積が2.5m2/g、d002が0.3357nm、Lcが108nm、全細孔容積が10.5μL/g、平均円形度が0.89、配向性I110/I004が0.11であった。
その後、実施例1の人造黒鉛粒子(B1)に代えて、人造黒鉛粒子(B2)を用いた以外は実施例1と同様の方法により複合材料(2)を得た。
この複合材料(2)について、粉体物性及び電池特性を評価した結果を表2に示す。
実施例2記載の粉末コークス2を黒鉛るつぼに充填し、アチソン炉にて最高到達温度が約3300℃となるように1週間かけて加熱処理を行い、粒子が非鱗片状の人造黒鉛粒子(B3)を得た。この得られた非鱗片状の人造黒鉛粒子(B3)の各種物性を表1に示す。D50が12.2μm、BET比表面積が1.0m2/g、d002が0.3357nm、Lcが108nm、全細孔容積が5.0μL/g、平均円形度が0.89、配向性I110/I004が0.11であった。
その後、実施例1の人造黒鉛粒子(B1)に代えて、人造黒鉛粒子(B3)を用いた以外は実施例1と同様の方法により複合材料(3)を得た。
この複合材料(3)について、粉体物性及び電池特性を評価した結果を表2に示す。
実施例1に記載のコークス1に対し、内筒中心部外壁温度を1450℃に設定したロータリーキルン(電気ヒーター外熱式、酸化アルミニウムSSA-S、φ120mm内筒管)を用い、滞留時間が15分となるようにフィード量及び傾斜角を調整し、加熱を行うことでコークスをか焼し、か焼コークス1を得た。
このか焼コークス1をホソカワミクロン製バンタムミルで粉砕し、その後45μm目開きの篩を用いて粗粉をカットした。次に、日清エンジニアリング製ターボクラシファイアーTC-15Nで気流分級し、粒径が1.0μm以下の粒子を実質的に含まない粉末か焼コークス1を得た。
この粉末か焼コークス1を黒鉛るつぼに充填し、アチソン炉にて最高到達温度が約3300℃となるように1週間かけて加熱処理を行い、粒子が鱗片状である人造黒鉛粒子(B4)を得た。このとき、黒鉛るつぼには複数の通気孔が設けられている。得られた鱗片状の人造黒鉛粒子(B4)の各種物性を測定した結果を表1に示す。D50が19.3μm、BET比表面積が2.1m2/g、d002が0.3357nm、Lcが105nm、全細孔容積が9.2μL/g、平均円形度が0.83、配向性I110/I004が0.04であった。
その後、実施例1の人造黒鉛粒子(B1)に代えて、人造黒鉛粒子(B4)を用いた以外は実施例1と同様の方法により複合材料(4)を得た。
この複合材料(4)について、粉体物性及び電池特性を評価した結果を表2に示す。
黒鉛粒子として球状天然黒鉛(B5)の各種物性を測定した結果を表1に示す。D50が16.8μm、d002が0.3355nm、BET比表面積が1.8m2/g、Lcが109nm、全細孔容積が0.13μL/g、平均円形度が0.92、配向性I110/I004が0.29であった。
実施例1の人造黒鉛粒子(B1)に代えて、球状天然黒鉛粒子(B5)を用いた以外は実施例1と同様の方法により複合材料(5)を得た。
この複合材料(5)について、粉体物性及び電池特性を評価した結果を表2に示す。
黒鉛粒子としてメソフェーズ球状黒鉛(B6)の各種物性を測定した結果を表1に示す。D50が16.2μm、d002が0.3365nm、BET比表面積が1.5m2/g、Lcが60nm、全細孔容積が9.3μL/g、平均円形度が0.97、配向性I110/I004が0.65であった。
実施例1の人造黒鉛粒子(B1)に代えて、メソフェーズ球状黒鉛(B6)を用いた以外は実施例1と同様の方法により複合材料(6)を得た。
この複合材料(6)について、粉体物性及び電池特性を評価した結果を表2に示す。
黒鉛粒子として塊状黒鉛(B7)の各種物性を測定した結果を表1に示す。D50が3.0μm、d002が0.3365nm、BET比表面積が1.4m2/g、Lcが65nm、全細孔容積が11.8μL/g、平均円形度が0.90、配向性I110/I004が0.38であった。
実施例1の人造黒鉛粒子(B1)に代えて、塊状黒鉛(B7)を用いた以外は実施例1と同様の方法により複合材料(7)を得た。
この複合材料(7)について、粉体物性及び電池特性を評価した結果を表2に示す。
黒鉛粒子として小粒径塊状黒鉛(B8)の各種物性を測定した結果を表1に示す。D50が6.2μm、d002が0.3363nm、BET比表面積が3.2m2/g、Lcが65nm、全細孔容積が25.0μL/g、平均円形度が0.90、配向性I110/I004が0.48であった。
実施例1の人造黒鉛粒子(B1)に代えて、小粒径塊状黒鉛(B8)を用いた以外は実施例1と同様の方法により複合材料(8)を得た。
この複合材料(8)について、粉体物性及び電池特性を評価した結果を表2に示す。
実施例2のケイ素含有粒子に代えて、一次粒子径の数基準平均粒子径500nm、BET比表面積5.2m2/g、ICP(誘導結合プラズマ)により定量したSi微粒子に含まれる酸素含有率2.6質量%であるケイ素含有粒子(A2)を用いた以外は実施例2と同様の方法により複合材料(9)を得た。
この複合材料(9)について、粉体物性及び電池特性を評価した結果を表2に示す。
実施例2において、石油ピッチを加えない、つまり、ケイ素含有粒子と人造黒鉛粒子(B2)を単純混合して混合材料(10)を得た。
この混合材料(10)について、粉体物性及び電池特性を評価した結果を表2に示す。
実施例2において、石油ピッチを24.0質量部にしてケイ素含有粒子と均一に加熱溶融混合させた混合物と人造黒鉛粒子(B2)78.0質量部を混合後に焼成した。焼成品をロータリーカッターミルで何度も繰り返して解砕して、篩下回収品の比表面積が10.1m2/gになるまで解砕を繰り返すことで複合材料(11)とした。
この複合材料(11)について、粉体物性及び電池特性を評価した結果を表2に示す。
Claims (13)
- ケイ素含有粒子と人造黒鉛粒子と炭素質材料とを含むリチウムイオン電池用負極材であって、前記のケイ素含有粒子と人造黒鉛粒子と炭素質材料はその少なくとも一部が複合化している複合粒子であり、
前記ケイ素含有粒子は、粒子表面にSiOx層(0<x≦2)を有するケイ素粒子であって、酸素含有率が1.0質量%以上18.0質量%以下であり、200nm以下の一次粒子径を有する粒子を主成分とするものであり、
前記人造黒鉛粒子は、レーザー回折法による体積基準累積粒度分布における50%累積時の粒子径D50が1.0μm以上15.0μm以下の非鱗片状人造黒鉛粒子である、リチウムイオン電池用負極材。 - 前記人造黒鉛粒子は、粉末XRD測定から得られる黒鉛結晶の(110)面のピーク強度I110と(004)面のピーク強度I004の比I110/I004が0.10以上0.35以下、X線回折法による(002)面の平均面間隔d002が0.3360nm以下、平均円形度が0.80以上0.95以下、窒素ガス吸着法によって測定される直径0.4μm以下の細孔の全細孔容積が5.0μL/g以上40.0μL/g以下である非鱗片状人造黒鉛粒子であって、前記人造黒鉛粒子の断面において観察される光学組織について、面積の小さな組織から面積を累積し、その累計面積が全光学組織面積の60%の面積となるときの光学組織の面積をSOPとし、アスペクト比の小さな組織から組織の数を数え組織全体の数の60%番目の組織におけるアスペクト比をAROP、レーザー回折法による体積基準累積粒度分布における50%累積時の粒子径をD50としたとき、
1.5≦AROP≦6.0 および
0.2×D50≦(SOP×AROP)1/2<2×D50
の関係を有するものである、請求項1に記載のリチウムイオン電池用負極材。 - 前記人造黒鉛粒子は、レーザー回折法による体積基準累積粒度分布における50%累積時の粒子径D50が10.0μm以下である、請求項1または2に記載のリチウムイオン電池用負極材。
- 前記ケイ素含有粒子の含有量が、前記人造黒鉛粒子を100質量部としたとき5.0質量部以上30.0質量部以下である、請求項1乃至3のいずれか1項に記載のリチウムイオン電池用負極材。
- 前記炭素質材料が、石油ピッチまたは石炭ピッチを熱処理してなるものである、請求項1乃至4のいずれか1項に記載のリチウムイオン電池用負極材。
- 前記炭素質材料の量が、前記のケイ素含有粒子と人造黒鉛粒子と炭素質材料との合計に対し2.0質量%以上40.0質量%以下である、請求項1乃至5のいずれか1項に記載のリチウムイオン電池用負極材。
- 前記リチウムイオン電池用負極材は、レーザー回折法による体積基準累積粒度分布における50%累積時の粒子径D50が2.0μm以上18.0μm以下である、請求項1乃至6のいずれか1項に記載のリチウムイオン電池用負極材。
- 前記リチウムイオン電池用負極材は、BET比表面積が2.0m2/g以上10.0m2/g以下である、請求項1乃至7のいずれか1項に記載のリチウムイオン電池用負極材。
- 前記リチウムイオン電池用負極材は、X線回折法による前記黒鉛粒子の(002)面の平均面間隔d002が0.3360nm以下である請求項1乃至8のいずれか1項に記載のリチウムイオン電池用負極材。
- 前記リチウムイオン電池用負極材は、顕微ラマン分光測定器で前記複合粒子を測定した際ラマン分光スペクトルで測定される1300~1400cm-1の範囲にあるピークのピーク強度IDと1580~1620cm-1の範囲にあるピークのピーク強度IGとの比ID/IG(R値)が0.15以上1.00以下である、請求項1乃至9のいずれか1項に記載のリチウムイオン電池用負極材。
- 請求項1乃至10のいずれか1項に記載のリチウムイオン電池用負極材とバインダーとを含むペースト。
- 請求項11に記載のペーストの成形体を含むリチウムイオン電池用負極。
- 請求項12に記載の負極を構成要素として含むリチウムイオン電池。
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201680037961.7A CN107710467B (zh) | 2015-07-02 | 2016-07-01 | 锂离子电池用负极材料和其用途 |
JP2017526449A JP6703988B2 (ja) | 2015-07-02 | 2016-07-01 | リチウムイオン電池用負極材及びその用途 |
EP16818067.7A EP3319154A4 (en) | 2015-07-02 | 2016-07-01 | NEGATIVE ELECTRODE MATERIAL FOR LITHIUM ION BATTERIES AND USE THEREOF |
US15/740,868 US11031587B2 (en) | 2015-07-02 | 2016-07-01 | Negative electrode material for lithium-ion batteries including non-flaky artificial graphite including silicon-containing particles, artificial graphite particles and carbonaceous material |
KR1020187000527A KR102132618B1 (ko) | 2015-07-02 | 2016-07-01 | 리튬 이온 전지용 부극재 및 그 용도 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2015133590 | 2015-07-02 | ||
JP2015-133590 | 2015-07-02 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2017002959A1 true WO2017002959A1 (ja) | 2017-01-05 |
Family
ID=57608261
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2016/069633 WO2017002959A1 (ja) | 2015-07-02 | 2016-07-01 | リチウムイオン電池用負極材及びその用途 |
Country Status (6)
Country | Link |
---|---|
US (1) | US11031587B2 (ja) |
EP (1) | EP3319154A4 (ja) |
JP (1) | JP6703988B2 (ja) |
KR (1) | KR102132618B1 (ja) |
CN (1) | CN107710467B (ja) |
WO (1) | WO2017002959A1 (ja) |
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20190074118A (ko) * | 2017-12-19 | 2019-06-27 | 주식회사 엘지화학 | 리튬이차전지용 음극 활물질, 이의 제조방법 및 이를 사용하여 제조된 리튬이차전지 |
WO2019131863A1 (ja) * | 2017-12-28 | 2019-07-04 | 昭和電工株式会社 | リチウムイオン二次電池用負極材 |
WO2019131860A1 (ja) * | 2017-12-28 | 2019-07-04 | 昭和電工株式会社 | リチウムイオン二次電池用負極材 |
WO2019131864A1 (ja) * | 2017-12-28 | 2019-07-04 | 昭和電工株式会社 | リチウムイオン二次電池用負極材 |
EP3518328A1 (en) * | 2018-01-26 | 2019-07-31 | Samsung Electronics Co., Ltd. | Silicon-containing structure, method of preparing the same, carbon composite using the same, and electrode, lithium battery, and device each including the same |
WO2019220576A1 (ja) * | 2018-05-16 | 2019-11-21 | 日立化成株式会社 | リチウムイオン二次電池用負極材、リチウムイオン二次電池用負極材の製造方法、リチウムイオン二次電池用負極及びリチウムイオン二次電池 |
JPWO2019131862A1 (ja) * | 2017-12-28 | 2019-12-26 | 昭和電工株式会社 | リチウムイオン二次電池用負極材 |
JP2020102312A (ja) * | 2018-12-20 | 2020-07-02 | トヨタ自動車株式会社 | 非水系リチウム二次電池の負極材料 |
JP2020114804A (ja) * | 2020-05-12 | 2020-07-30 | 株式会社 東北テクノアーチ | 多孔質炭素材料 |
JPWO2019186828A1 (ja) * | 2018-03-28 | 2021-03-18 | 昭和電工マテリアルズ株式会社 | リチウムイオン二次電池用負極材、リチウムイオン二次電池用負極材の製造方法、リチウムイオン二次電池用負極材スラリー、リチウムイオン二次電池用負極、及びリチウムイオン二次電池 |
JPWO2021125333A1 (ja) * | 2019-12-20 | 2021-06-24 | ||
JP6911221B1 (ja) * | 2020-01-28 | 2021-07-28 | Jfeケミカル株式会社 | 炭素質材料、炭素質材料の製造方法、リチウムイオン二次電池用負極およびリチウムイオン二次電池 |
WO2021153080A1 (ja) * | 2020-01-28 | 2021-08-05 | Jfeケミカル株式会社 | 炭素質材料、炭素質材料の製造方法、リチウムイオン二次電池用負極およびリチウムイオン二次電池 |
US11899038B2 (en) | 2019-12-20 | 2024-02-13 | Resonac Corporation | Acceleration sensor, acceleration evaluation method using same, and load provided with acceleration sensor |
Families Citing this family (37)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3142174B1 (en) * | 2015-09-14 | 2021-02-17 | Toyota Jidosha Kabushiki Kaisha | All-solid-state battery system and method of manufacturing the same |
KR101995373B1 (ko) * | 2016-07-04 | 2019-09-24 | 주식회사 엘지화학 | 이차 전지용 음극 |
US11495792B2 (en) | 2017-02-16 | 2022-11-08 | Global Graphene Group, Inc. | Method of manufacturing a lithium secondary battery having a protected high-capacity anode active material |
US10840502B2 (en) | 2017-02-24 | 2020-11-17 | Global Graphene Group, Inc. | Polymer binder for lithium battery and method of manufacturing |
US11978904B2 (en) | 2017-02-24 | 2024-05-07 | Honeycomb Battery Company | Polymer binder for lithium battery and method of manufacturing |
US10985373B2 (en) | 2017-02-27 | 2021-04-20 | Global Graphene Group, Inc. | Lithium battery cathode and method of manufacturing |
US11742475B2 (en) | 2017-04-03 | 2023-08-29 | Global Graphene Group, Inc. | Encapsulated anode active material particles, lithium secondary batteries containing same, and method of manufacturing |
US10483533B2 (en) | 2017-04-10 | 2019-11-19 | Global Graphene Group, Inc. | Encapsulated cathode active material particles, lithium secondary batteries containing same, and method of manufacturing |
US10862129B2 (en) | 2017-04-12 | 2020-12-08 | Global Graphene Group, Inc. | Lithium anode-protecting polymer layer for a lithium metal secondary battery and manufacturing method |
US10964951B2 (en) | 2017-08-14 | 2021-03-30 | Global Graphene Group, Inc. | Anode-protecting layer for a lithium metal secondary battery and manufacturing method |
US11721832B2 (en) | 2018-02-23 | 2023-08-08 | Global Graphene Group, Inc. | Elastomer composite-encapsulated particles of anode active materials for lithium batteries |
KR20190113391A (ko) * | 2018-03-28 | 2019-10-08 | 삼성전자주식회사 | 디플루오로실란계 첨가제를 포함하는 리튬이차전지 |
US11043694B2 (en) | 2018-04-16 | 2021-06-22 | Global Graphene Group, Inc. | Alkali metal-selenium secondary battery containing a cathode of encapsulated selenium particles |
US11450849B2 (en) * | 2018-06-15 | 2022-09-20 | Umicore | Active material powder for use in a negative electrode of a battery and a battery comprising such an active material powder |
US11121398B2 (en) | 2018-06-15 | 2021-09-14 | Global Graphene Group, Inc. | Alkali metal-sulfur secondary battery containing cathode material particulates |
US10978744B2 (en) | 2018-06-18 | 2021-04-13 | Global Graphene Group, Inc. | Method of protecting anode of a lithium-sulfur battery |
KR102486245B1 (ko) * | 2018-08-13 | 2023-01-10 | 주식회사 엘지에너지솔루션 | 리튬 이차전지용 음극 및 이를 포함하는 리튬 이차전지 |
US11043662B2 (en) | 2018-08-22 | 2021-06-22 | Global Graphene Group, Inc. | Electrochemically stable elastomer-encapsulated particles of cathode active materials for lithium batteries |
US11239460B2 (en) | 2018-08-22 | 2022-02-01 | Global Graphene Group, Inc. | Method of producing electrochemically stable elastomer-encapsulated particles of cathode active materials for lithium batteries |
US11223049B2 (en) | 2018-08-24 | 2022-01-11 | Global Graphene Group, Inc. | Method of producing protected particles of cathode active materials for lithium batteries |
US10971724B2 (en) * | 2018-10-15 | 2021-04-06 | Global Graphene Group, Inc. | Method of producing electrochemically stable anode particulates for lithium secondary batteries |
US10629899B1 (en) * | 2018-10-15 | 2020-04-21 | Global Graphene Group, Inc. | Production method for electrochemically stable anode particulates for lithium secondary batteries |
CN109616614B (zh) * | 2018-12-14 | 2020-12-11 | 宁德新能源科技有限公司 | 负极极片和使用其的电化学装置和电子装置 |
JP7178271B2 (ja) * | 2019-01-15 | 2022-11-25 | Eneos株式会社 | 人造黒鉛材料、人造黒鉛材料の製造方法、リチウムイオン二次電池用負極およびリチウムイオン二次電池 |
US10971725B2 (en) | 2019-01-24 | 2021-04-06 | Global Graphene Group, Inc. | Lithium metal secondary battery containing elastic polymer foam as an anode-protecting layer |
EP3981038A4 (en) * | 2019-06-11 | 2023-12-20 | The Regents of the University of Michigan | 3-D COMPOSITE ANODES OF HIGH CAPACITY AND FAST CHARGING LI-ION BATTERIES |
CN111430677B (zh) * | 2019-09-30 | 2022-05-24 | 蜂巢能源科技有限公司 | 负极材料及其制备方法、负极和锂离子电池 |
CN110931742B (zh) * | 2019-11-28 | 2021-03-02 | 宁德新能源科技有限公司 | 负极及包含其的电化学装置和电子装置 |
CN113540426B (zh) * | 2019-11-28 | 2022-09-09 | 宁德新能源科技有限公司 | 负极材料及包含其的电化学装置和电子装置 |
EP3859827B1 (en) * | 2019-12-06 | 2022-08-17 | Contemporary Amperex Technology Co., Limited | Secondary battery and apparatus including the secondary battery |
JP7396009B2 (ja) * | 2019-12-10 | 2023-12-12 | 三菱マテリアル株式会社 | シリコン微粒子及びその製造方法 |
WO2021127991A1 (zh) | 2019-12-24 | 2021-07-01 | 东莞新能源科技有限公司 | 电化学装置和电子装置 |
CN111082129B (zh) * | 2019-12-24 | 2021-01-12 | 东莞新能源科技有限公司 | 电化学装置和电子装置 |
CN112858077A (zh) * | 2020-12-31 | 2021-05-28 | 合肥国轩高科动力能源有限公司 | 一种极片表面粉尘异物探测及评估方法 |
KR20220109698A (ko) * | 2021-01-29 | 2022-08-05 | 주식회사 엘지에너지솔루션 | 음극 및 이를 포함하는 이차전지 |
CN113745468B (zh) * | 2021-09-08 | 2023-09-26 | 珠海冠宇电池股份有限公司 | 一种锂离子电池和电子装置 |
WO2024049235A1 (ko) * | 2022-08-31 | 2024-03-07 | 주식회사 엘지에너지솔루션 | 음극 활물질, 음극 활물질의 제조 방법, 음극 조성물, 이를 포함하는 리튬 이차 전지용 음극 및 음극을 포함하는 리튬 이차 전지 |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005108774A (ja) * | 2003-10-01 | 2005-04-21 | Samsung Sdi Co Ltd | リチウム二次電池用負極活物質及びリチウム二次電池及びリチウム二次電池用負極活物質の製造方法 |
WO2009063902A1 (ja) * | 2007-11-12 | 2009-05-22 | Hitachi Maxell, Ltd. | 非水二次電池用電極およびそれを用いた非水二次電池、並びに電極の製造方法 |
JP2012009457A (ja) * | 2011-10-07 | 2012-01-12 | Gs Yuasa Corp | 非水電解質二次電池 |
JP2012099452A (ja) * | 2010-11-04 | 2012-05-24 | Samsung Sdi Co Ltd | 2次電池用負極活物質およびこれを含むリチウム2次電池 |
WO2015016182A1 (ja) * | 2013-07-29 | 2015-02-05 | 昭和電工株式会社 | 炭素材料、電池電極用材料、及び電池 |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4137350B2 (ja) | 2000-06-16 | 2008-08-20 | 三星エスディアイ株式会社 | リチウム二次電池用の負極材料及びリチウム二次電池用の電極及びリチウム二次電池並びにリチウム二次電池用の負極材料の製造方法 |
KR101107041B1 (ko) | 2002-05-08 | 2012-01-25 | 가부시키가이샤 지에스 유아사 | 비수전해질 2차전지 |
US20050074672A1 (en) | 2003-10-01 | 2005-04-07 | Keiko Matsubara | Negative active material for rechargeable lithium battery, method of preparing same and rechargeable lithium battery using same |
JP4519592B2 (ja) * | 2004-09-24 | 2010-08-04 | 株式会社東芝 | 非水電解質二次電池用負極活物質及び非水電解質二次電池 |
KR101384216B1 (ko) * | 2009-03-02 | 2014-04-14 | (주)포스코켐텍 | 복합 흑연 입자 및 이를 이용한 리튬 2차 전지 |
EP2413403B1 (en) | 2009-03-27 | 2018-03-07 | Mitsubishi Chemical Corporation | Negative electrode material for non-aqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery using same |
WO2011035876A1 (en) * | 2009-09-23 | 2011-03-31 | Umicore | New silicon based electrode formulations for lithium-ion batteries and method for obtaining it |
JP5494343B2 (ja) * | 2010-08-12 | 2014-05-14 | 日立化成株式会社 | リチウム二次電池用負極材、リチウムイオン二次電池用負極、およびリチウムイオン二次電池 |
JP6085994B2 (ja) | 2012-04-27 | 2017-03-01 | 日産自動車株式会社 | 非水電解質二次電池の製造方法 |
KR101857981B1 (ko) * | 2013-08-05 | 2018-05-15 | 쇼와 덴코 가부시키가이샤 | 리튬 이온 전지용 부극재 및 그 용도 |
-
2016
- 2016-07-01 CN CN201680037961.7A patent/CN107710467B/zh active Active
- 2016-07-01 WO PCT/JP2016/069633 patent/WO2017002959A1/ja active Application Filing
- 2016-07-01 JP JP2017526449A patent/JP6703988B2/ja active Active
- 2016-07-01 KR KR1020187000527A patent/KR102132618B1/ko active IP Right Grant
- 2016-07-01 EP EP16818067.7A patent/EP3319154A4/en active Pending
- 2016-07-01 US US15/740,868 patent/US11031587B2/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005108774A (ja) * | 2003-10-01 | 2005-04-21 | Samsung Sdi Co Ltd | リチウム二次電池用負極活物質及びリチウム二次電池及びリチウム二次電池用負極活物質の製造方法 |
WO2009063902A1 (ja) * | 2007-11-12 | 2009-05-22 | Hitachi Maxell, Ltd. | 非水二次電池用電極およびそれを用いた非水二次電池、並びに電極の製造方法 |
JP2012099452A (ja) * | 2010-11-04 | 2012-05-24 | Samsung Sdi Co Ltd | 2次電池用負極活物質およびこれを含むリチウム2次電池 |
JP2012009457A (ja) * | 2011-10-07 | 2012-01-12 | Gs Yuasa Corp | 非水電解質二次電池 |
WO2015016182A1 (ja) * | 2013-07-29 | 2015-02-05 | 昭和電工株式会社 | 炭素材料、電池電極用材料、及び電池 |
Non-Patent Citations (1)
Title |
---|
See also references of EP3319154A4 * |
Cited By (27)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20190074118A (ko) * | 2017-12-19 | 2019-06-27 | 주식회사 엘지화학 | 리튬이차전지용 음극 활물질, 이의 제조방법 및 이를 사용하여 제조된 리튬이차전지 |
US11916222B2 (en) | 2017-12-19 | 2024-02-27 | Lg Energy Solution, Ltd. | Negative electrode active material for lithium secondary battery, method for preparing the same and lithium secondary battery obtained by using the same |
CN110892562B (zh) * | 2017-12-19 | 2023-03-28 | 株式会社Lg新能源 | 锂二次电池用负极活性材料、其制造方法和通过使用其而获得的锂二次电池 |
US11424440B2 (en) | 2017-12-19 | 2022-08-23 | Lg Energy Solution, Ltd. | Negative electrode active material for lithium secondary battery, method for preparing the same and lithium secondary battery obtained by using the same |
CN110892562A (zh) * | 2017-12-19 | 2020-03-17 | 株式会社Lg化学 | 锂二次电池用负极活性材料、其制造方法和通过使用其而获得的锂二次电池 |
KR102321502B1 (ko) * | 2017-12-19 | 2021-11-02 | 주식회사 엘지에너지솔루션 | 리튬이차전지용 음극 활물질, 이의 제조방법 및 이를 사용하여 제조된 리튬이차전지 |
WO2019131863A1 (ja) * | 2017-12-28 | 2019-07-04 | 昭和電工株式会社 | リチウムイオン二次電池用負極材 |
WO2019131860A1 (ja) * | 2017-12-28 | 2019-07-04 | 昭和電工株式会社 | リチウムイオン二次電池用負極材 |
WO2019131864A1 (ja) * | 2017-12-28 | 2019-07-04 | 昭和電工株式会社 | リチウムイオン二次電池用負極材 |
JPWO2019131862A1 (ja) * | 2017-12-28 | 2019-12-26 | 昭和電工株式会社 | リチウムイオン二次電池用負極材 |
US10974965B2 (en) | 2018-01-26 | 2021-04-13 | Samsung Electronics Co., Ltd. | Silicon-containing structure, method of preparing the same, carbon composite using the same, and electrode, lithium battery, and device each including the same |
EP3518328A1 (en) * | 2018-01-26 | 2019-07-31 | Samsung Electronics Co., Ltd. | Silicon-containing structure, method of preparing the same, carbon composite using the same, and electrode, lithium battery, and device each including the same |
CN110085856A (zh) * | 2018-01-26 | 2019-08-02 | 三星电子株式会社 | 含硅结构体、其制备方法、使用其的碳复合物及各自包括其的电极、锂电池和设备 |
JPWO2019186828A1 (ja) * | 2018-03-28 | 2021-03-18 | 昭和電工マテリアルズ株式会社 | リチウムイオン二次電池用負極材、リチウムイオン二次電池用負極材の製造方法、リチウムイオン二次電池用負極材スラリー、リチウムイオン二次電池用負極、及びリチウムイオン二次電池 |
EP3780184A4 (en) * | 2018-03-28 | 2021-10-20 | Showa Denko Materials Co., Ltd. | NEGATIVE ELECTRODE MATERIAL FOR LITHIUM ION SECONDARY BATTERY, METHOD FOR PRODUCING THE NEGATIVE ELECTRODE MATERIAL FOR LITHIUM ION SECONDARY BATTERY, NEGATIVELEKTRODENMATERIALSCHLÄMME FOR LITHIUM-ION SECONDARY BATTERY, NEGATIVE ELECTRODE FOR LITHIUM-ION SEKUNDÄBATTERIE AND LITHIUM-ION SECONDARY BATTERY |
JP7226431B2 (ja) | 2018-03-28 | 2023-02-21 | 株式会社レゾナック | リチウムイオン二次電池用負極材、リチウムイオン二次電池用負極材の製造方法、リチウムイオン二次電池用負極材スラリー、リチウムイオン二次電池用負極、及びリチウムイオン二次電池 |
WO2019220576A1 (ja) * | 2018-05-16 | 2019-11-21 | 日立化成株式会社 | リチウムイオン二次電池用負極材、リチウムイオン二次電池用負極材の製造方法、リチウムイオン二次電池用負極及びリチウムイオン二次電池 |
JP7265697B2 (ja) | 2018-12-20 | 2023-04-27 | トヨタ自動車株式会社 | 非水系リチウム二次電池の負極材料 |
JP2020102312A (ja) * | 2018-12-20 | 2020-07-02 | トヨタ自動車株式会社 | 非水系リチウム二次電池の負極材料 |
JPWO2021125333A1 (ja) * | 2019-12-20 | 2021-06-24 | ||
WO2021125333A1 (ja) * | 2019-12-20 | 2021-06-24 | 昭和電工株式会社 | 透明材料中のナノワイヤの配向性評価方法、並びにそれを用いた工程管理方法、及び樹脂硬化物の製造方法 |
US11899038B2 (en) | 2019-12-20 | 2024-02-13 | Resonac Corporation | Acceleration sensor, acceleration evaluation method using same, and load provided with acceleration sensor |
JP7279819B2 (ja) | 2019-12-20 | 2023-05-23 | 株式会社レゾナック | 透明材料中のナノワイヤの配向性評価方法、並びにそれを用いた工程管理方法、及び樹脂硬化物の製造方法 |
JP6911221B1 (ja) * | 2020-01-28 | 2021-07-28 | Jfeケミカル株式会社 | 炭素質材料、炭素質材料の製造方法、リチウムイオン二次電池用負極およびリチウムイオン二次電池 |
WO2021153080A1 (ja) * | 2020-01-28 | 2021-08-05 | Jfeケミカル株式会社 | 炭素質材料、炭素質材料の製造方法、リチウムイオン二次電池用負極およびリチウムイオン二次電池 |
JP7093085B2 (ja) | 2020-05-12 | 2022-06-29 | 株式会社 東北テクノアーチ | 多孔質炭素材料 |
JP2020114804A (ja) * | 2020-05-12 | 2020-07-30 | 株式会社 東北テクノアーチ | 多孔質炭素材料 |
Also Published As
Publication number | Publication date |
---|---|
US20180190975A1 (en) | 2018-07-05 |
KR20180015251A (ko) | 2018-02-12 |
JP6703988B2 (ja) | 2020-06-03 |
CN107710467A (zh) | 2018-02-16 |
JPWO2017002959A1 (ja) | 2018-04-12 |
EP3319154A4 (en) | 2019-03-20 |
CN107710467B (zh) | 2021-07-09 |
EP3319154A1 (en) | 2018-05-09 |
US11031587B2 (en) | 2021-06-08 |
KR102132618B1 (ko) | 2020-07-13 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
KR102132618B1 (ko) | 리튬 이온 전지용 부극재 및 그 용도 | |
JP6442419B2 (ja) | リチウムイオン二次電池用負極活物質 | |
JP6664040B2 (ja) | リチウムイオン電池用負極材及びその用途 | |
WO2018047939A1 (ja) | リチウムイオン二次電池用負極材 | |
JP5461746B1 (ja) | 炭素材料、電池電極用炭素材料、及び電池 | |
JP6476116B2 (ja) | 炭素材料、電池電極用材料、及び電池 | |
WO2015019993A1 (ja) | 複合体の製造方法及びリチウムイオン電池用負極材 | |
JP5877284B1 (ja) | 炭素材料、その製造方法及びその用途 | |
JP5571270B1 (ja) | 炭素材料、電池電極用炭素材料、及び電池 | |
JP6605512B2 (ja) | 炭素材料、その製造方法及びその用途 |
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: 16818067 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2017526449 Country of ref document: JP Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: 20187000527 Country of ref document: KR Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2016818067 Country of ref document: EP |