WO2020179409A1 - Structure de sioc et composition pour électrode négative utilisant celle-ci, électrode négative et batterie secondaire - Google Patents

Structure de sioc et composition pour électrode négative utilisant celle-ci, électrode négative et batterie secondaire Download PDF

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WO2020179409A1
WO2020179409A1 PCT/JP2020/005738 JP2020005738W WO2020179409A1 WO 2020179409 A1 WO2020179409 A1 WO 2020179409A1 JP 2020005738 W JP2020005738 W JP 2020005738W WO 2020179409 A1 WO2020179409 A1 WO 2020179409A1
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silicon
sioc
negative electrode
based fine
substituted
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PCT/JP2020/005738
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Japanese (ja)
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浩綱 山田
三和子 西村
正一 近藤
創一朗 佐藤
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Jnc株式会社
Jnc石油化学株式会社
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    • 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
    • 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
    • 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
    • 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 disclosure relates to a SiOC structure, and a negative electrode composition, a negative electrode, and a secondary battery used therein.
  • This application is based on the Japanese Patent Application No. submitted to the Japan Patent Office on March 1, 2019. The priority is claimed based on JP2019-038011 (Japanese Patent Application No. 2019-038011), and the contents of the above-mentioned Japanese patent application are incorporated herein for all purposes.
  • Secondary batteries are used as a drive power source in various electronic devices, communication devices, and eco-cars such as hybrid vehicles.
  • a lithium intercalation compound that releases lithium ions from the layers is mainly used as the positive electrode material, and a carbonaceous material capable of storing and releasing lithium ions between the crystal planes during charging and discharging (for example,).
  • Various lithium-ion batteries using graphite or the like as the negative electrode material have been developed and put into practical use.
  • Patent Document 1 describes a SiOC composite material obtained by physically mixing various polysilsesquioxane and silicon particles and heat-treating the resulting mixture under predetermined conditions, and the same.
  • a negative electrode and a lithium-ion battery using a SiOC composite material as a negative electrode active material are disclosed.
  • Patent Document 1 shows that the use of the negative electrode active material can improve the battery capacity and cycle durability in a battery cycle test.
  • Patent Document 1 describes that in the disclosed SiOC composite material, silicon particles are embedded in a SiOC matrix derived from polysilsesquioxane, but silicon in the SiOC matrix is described.
  • Embedding of particles refers to a structure realized by physical mixing of polysilsesquioxane and silicon particles as described above, that is, a structure in which silicon particles are simply dispersed in a SiOC matrix. Understood to do.
  • Patent Document 2 discloses a negative electrode material composed of composite particles in which all or a part of inorganic particles capable of occluding/desorbing lithium ions are coated with ceramics. More specifically, the negative electrode material disclosed in Patent Document 2 contains at least one of the inorganic particles selected from the group consisting of Si, Sn and Zn as a constituent element, and the ceramics include Si, Ti, Al and A negative electrode material for a non-aqueous electrolyte secondary battery, which is composed of an oxide, a nitride or a carbide containing at least one element selected from the group consisting of Zr.
  • Patent Document 2 according to the negative electrode material having such a configuration, the volume change of the negative electrode material that may occur due to intercalation / deintercalation of lithium ions or the like can be reduced, and the battery characteristics such as charge / discharge cycle characteristics can be improved. Is suggested.
  • Patent Document 2 discloses some examples in which inorganic fine particles made of Si or the like are coated with SiOC ceramics. In view of these examples, Patent Document 2 discloses it. The obtained negative electrode material is manufactured through the following manufacturing steps.
  • phenyltrimethoxysilane is solized as a precursor organic molecule
  • the above-mentioned inorganic fine particles are added to the sol obtained thereby, and the hydrolysis reaction and the polycondensation reaction are further promoted to gelle to form a bulk gel.
  • the hydrolysis reaction and the polycondensation reaction are further promoted to gelle to form a bulk gel.
  • the negative electrode material disclosed in Patent Document 2 it is considered that the inorganic fine particles are held in a state of being dispersed in the SiOC ceramics derived from the bulk gel.
  • Patent Document 3 describes silicon composite particles obtained by sintering fine particles of silicon, a silicon alloy or silicon oxide together with an organosilicon compound or a mixture thereof, and a non-aqueous electrolyte using the silicon composite particles.
  • a negative electrode material for a secondary battery is disclosed.
  • a silicon-based inorganic compound formed by sintering the organosilicon compound or a mixture thereof serves as a binder, and silicon or silicon alloy fine particles are dispersed therein. It is characterized by having a structure in which voids are present in the particles.
  • Patent Document 3 shows that good cycle characteristics can be obtained by using such silicon composite particles as a negative electrode material.
  • the silicon composite particles disclosed in Patent Document 3 are obtained by curing a mixture of silicon fine particles and a curable siloxane composition composed of various organosilicon compounds such as a siloxane compound, and obtaining a mass obtained by curing the mixture. It is a crushed silicon composite obtained by heat treatment. Therefore, also in the negative electrode material disclosed in Patent Document 3, it is recognized that fine particles such as silicon exist in a state as if they were dispersed in the silicon composite.
  • Patent Document 4 discloses a negative electrode active material for a non-aqueous electrolyte secondary battery made of a ceramic composite material in which metallic silicon and SiC are dispersed in SiOC ceramics. More specifically, the ceramic composite material disclosed in Patent Document 4 has a peak intensity of the (111) plane diffraction line of the metallic silicon in b1 and (111) of the SiC in the X-ray diffraction using CuK ⁇ characteristic X-ray. ) When the peak intensity of the surface diffraction line is b2, the ratio represented by b1 / b2 and the density when compressed at 30 MPa are each within a predetermined numerical range.
  • Patent Document 4 suggests that a secondary battery using such a negative electrode active material made of a ceramic composite material exhibits excellent initial efficiency, charge / discharge capacity, and cycle characteristics.
  • the ceramic composite material disclosed in Patent Document 4 is manufactured through the following manufacturing steps. That is, the polymer obtained by adding metallic silicon particles to a carbon precursor solution in which a novolak type phenol resin as a carbon source is dissolved, then adding tetraethoxysilane, and polymerizing the silane compound is heat-cured and subjected to heat curing.
  • the ceramic composite material obtained by firing through the step of desolvation treatment is used as the negative electrode active material. Therefore, the ceramic composite material disclosed in Patent Document 4 is also one in which particles of metallic silicon and SiC are dispersed in SiOC ceramics.
  • Patent Document 5 which is a publication of a Chinese patent application, is considered to disclose a nanosilicon energy storage material having a core-shell structure as shown in each figure and a lithium ion battery containing the storage material.
  • the nanosilicon energy occlusion material disclosed in Patent Document 5 is obtained by subjecting Si nanoparticles to a surface treatment with a silane coupling agent and then subjecting the hydrolyzate of various organic silane compounds to the surface treatment. It is considered that the polycondensate obtained by uniformly dispersing Si nanoparticles and further polycondensing the hydrolyzate is coated with petroleum pitch and then fired to obtain a composite material.
  • the composite material has an intermediate layer derived from a core of silicon nanoparticles and a polymerizable organic siloxane, and an outer shell derived from petroleum pitch located outside the intermediate layer.
  • Patent Document 5 contains an SEM photograph showing the appearance of the actually obtained composite material (Fig. 5 of the document), but the result of examining the internal structure thereof. Is not shown at all, and there are many unclear points as to whether the core-shell structure as shown in the schematic views of FIGS. 3 and 4 of the relevant document is actually formed.
  • the present inventors have developed various negative electrode active materials including the negative electrode active material described in Patent Document 1, and in particular, the negative electrode active material using the SiOC composite material is industrially used.
  • the inventors of the present invention are developing various SiOC composite materials obtained by firing a composite material of silicon nanoparticles and polysilsesquioxane for use as a negative electrode active material.
  • the present inventors hydrolyzed a functional silane compound as a starting material for polysilsesquioxane synthesis, and then hydrolyzed the hydrolyzed product in the presence of silicon-based nanoparticles.
  • the silicon-based nanoparticles When the step of polycondensing polysilsesquioxane by polycondensation of polysilsesquioxane is performed under standing conditions instead of stirring conditions, the silicon-based nanoparticles have a polysilsesquioxane coat layer having a relatively smooth outer surface. A silicon-based nanoparticle/polysilsesquioxane complex uniformly coated with is produced, and the uniform coating structure of the silicon-based nanoparticle by such a coating layer is converted into a SiOC structure by heat treatment. Also found that it will be maintained.
  • the present inventors produced a lithium ion secondary battery using a SiOC structure having such a structure as a negative electrode active material, the battery characteristics such as cycle capacity retention rate and average Coulombic efficiency were improved to a certain extent. I have discovered that this can happen. That is, the present invention has been completed by the above discovery, and one of the main objects of the present disclosure is to provide a material for a negative electrode active material capable of realizing a good capacity retention rate and Coulomb efficiency, and a method for producing the material. , And a composition for a negative electrode using the material as a negative electrode active material, a negative electrode, and a secondary battery.
  • BET specific surface area is 20 m 2 / g or less,
  • the cumulative 10% particle size (D10), cumulative 50% particle size (D50), and cumulative 90% particle size (D90) obtained by the laser diffraction scattering particle size distribution measurement method are 1 nm ⁇ D50 ⁇ 990 ⁇ m and D90/D10. Satisfy the condition of ⁇ 13.0, SiOC structure.
  • a plurality of secondary particles are formed by completely covering the at least one silicon-based fine particle with the SiOC coat layer, and the plurality of secondary particles are connected to each other via the SiOC coat layer.
  • the secondary battery according to [16] which is a lithium ion secondary battery.
  • R 1 is a hydrogen, a hydroxyl group, or a substituted or unsubstituted hydrocarbon having 1 to 45 carbon atoms, and in the hydrocarbon having 1 to 45 carbon atoms, any hydrogen may be replaced with a halogen.
  • Any —CH 2 — may be replaced with —O—, —CH ⁇ CH—, cycloalkylene or cycloalkenylene
  • X 1 is a halogen, an alkyloxy having 1 to 6 carbon atoms, or an acetoxy.
  • n is an integer from 0 to 3.
  • the silane compound represented by the general formula (I) has the following general formula (II): R 10 Si (R 7 ) (R 8 ) (R 9 ) ⁇ ⁇ ⁇ (II) (In the formula, R 7 , R 8 and R 9 are each independently hydrogen, halogen, a hydroxyl group or alkyloxy having 1 to 4 carbons, and R 10 is substituted or unsubstituted alkyl having 1 to 45 carbons.
  • the silicon-containing polymer has the following general formulas (III), (IV), (V), and (VI).
  • R 1 and R 4 are each independently selected from the group consisting of substituted or unsubstituted alkyl having 1 to 45 carbon atoms, substituted or unsubstituted aryl, and substituted or unsubstituted arylalkyl; In the number 1 to 45 alkyl, any hydrogen may be replaced with a halogen and any —CH 2 — may be replaced with —O—, —CH ⁇ CH—, cycloalkylene or cycloalkenylene.
  • any hydrogen in the alkylene in the substituted or unsubstituted arylalkyl may be replaced by halogen, and any —CH 2 — may be replaced by —O—, —CH ⁇ CH— or cycloalkylene.
  • R 2 , R 3 , R 5 and R 6 are each independently selected from the group consisting of hydrogen, substituted or unsubstituted alkyl having 1 to 45 carbon atoms, substituted or unsubstituted aryl, and substituted or unsubstituted arylalkyl.
  • any hydrogen may be replaced by halogen, and any —CH 2 — is —O—, —CH ⁇ CH—, cycloalkylene, cycloalkenylene or — SiR 1 2 — may be replaced, and in the alkylene in the substituted or unsubstituted arylalkyl, any hydrogen may be replaced by halogen, and any —CH 2 — may be —O—, —CH ⁇ . It may be replaced with CH-, cycloalkylene, cycloalkenylene or -SiR 1 2- , and n represents an integer of 1 or more.
  • the method according to [18] or [19] comprising at least one selected from the group consisting of polysilsesquioxanes each having a polysilsesquioxane structure represented by
  • (P-3′) The pH of the mixed solution is adjusted to 2 or less by adding a predetermined amount of acid or a solution thereof to the mixed solution obtained in the step (p-2′), and then the mixed solution is mixed. By allowing the solution to stand for a predetermined time and at a predetermined temperature, polycondensation of the silane compound is allowed to proceed, and the silicon-based fine particle / silicon-containing polymer composite is produced.
  • the silane compound represented by the general formula (I) contains at least one silane compound selected from the group consisting of methyltrimethoxysilane and phenyltrimethoxysilane, [18] to The method according to any one of [24].
  • the non-oxidizing gas atmosphere in the step (q) is an atmosphere containing an inert gas.
  • the non-oxidizing gas atmosphere in the step (q) is an atmosphere containing nitrogen gas and/or argon gas.
  • the silicon-based fine particles/silicon-containing polymer composite is heated to a temperature in the range of 400° C. to 1800° C., and is heated at the temperature for 30 minutes to 10 hours.
  • a method for producing a negative electrode composition which comprises using the SiOC structure according to any one of [1] to [12] as a negative electrode active material to obtain the negative electrode composition.
  • a good cycle capacity retention rate and Coulombic efficiency can be realized in the secondary battery.
  • FIG. 7 is a view showing an SEM photograph (10,000 times) of the SiOC material obtained in Comparative Example 1.
  • FIG. 6 is a view showing a SEM photograph (20,000 times) of a silicon nanoparticle/methylpolysilsesquioxane complex obtained in Comparative Example 2. It is a figure which shows the SEM photograph (50,000 times) of the SiOC structure acquired in Example 1.
  • FIG. 6 is a diagram showing the results of measuring the particle size distributions of the SiOC structures obtained in Examples 1 and 2 and the SiOC material obtained in Comparative Example 1.
  • FIG. It is a figure which shows the result of having measured each particle size distribution of each SiOC structure acquired in Example 3 and 4, respectively.
  • FIG. 6 is a diagram showing the results of measuring the battery capacity by a charge/discharge cycle test for each lithium ion secondary battery produced in Examples 1 to 4 and Comparative Example 1.
  • FIG. 5 is a diagram showing the results of measuring Coulombic efficiency by a charge/discharge cycle test for each lithium ion secondary battery produced in Examples 1 to 4 and Comparative Example 1. It is a figure which shows the structural example of a coin type lithium ion battery.
  • SiOC structure According to the first aspect of the present invention, (A) With at least one silicon-based fine particle, (B) A SiOC coat layer containing at least Si (silicon), O (oxygen) and C (carbon) as constituent elements, and Including, The at least one silicon-based fine particle is coated with the SiOC coat layer. BET specific surface area is 20 m 2 / g or less, The cumulative 10% particle size (D10), cumulative 50% particle size (D50), and cumulative 90% particle size (D90) obtained by the laser diffraction scattering particle size distribution measurement method are 1 nm ⁇ D50 ⁇ 990 ⁇ m and D90/D10. Satisfy the condition of ⁇ 13.0, A SiOC structure is provided.
  • the SiOC structure according to the first aspect of the present invention will be described in detail.
  • SiOC structure contains at least one silicon-based fine particle.
  • silicon-based fine particles is a concept that includes silicon fine particles substantially consisting of only silicon, and fine particles consisting of a compound containing silicon (silicon) in the atomic composition (for example, silica, a silicon-containing metal compound). is there.
  • the particle size (volume-based average particle size) of silicon-based particles can be used as long as it is in the range of nanometer scale to micrometer scale.
  • silicon-based fine particles having a volume-based average particle diameter in the range of 1 nm to 2 ⁇ m can be used.
  • the volume-based average particle diameter (average particle diameter) of the silicon-based fine particles is, for example, 10 nm to 500 nm, preferably 10 nm to 200 nm, and more preferably 20 nm to 20 nm. It is preferably in the range of 100 nm.
  • the SiOC structure according to the first aspect of the present invention includes a SiOC coating layer that covers the at least one silicon-based fine particle.
  • the SiOC coating layer contains at least Si (silicon), O (oxygen), and C (carbon) as constituent elements, but in addition to these, the inclusion of other elements It is not excluded.
  • the SiOC coat layer is not particularly limited, but specifically, as described below, the coat layer containing at least one silicon-containing polymer and coating the silicon-based fine particles has a predetermined thickness. Anything may be ceramicized by the heat treatment of.
  • the SiOC structure according to the first aspect of the present invention is characterized in that "the at least one silicon-based fine particle is completely covered by the SiOC coating layer".
  • the SiOC structure has a structural portion in which at least one silicon-based fine particle is completely covered by the SiOC coating layer, and the SiOC structure is not necessarily required. It is not necessary that all of the silicon-based fine particles contained in the above are completely covered with the SiOC coat layer. That is, in some embodiments of the present invention, specific examples of the mode of coating the silicon-based fine particles with the SiOC coated layer include the following embodiments. (I) An embodiment in which all of the silicon-based fine particles contained in the SiOC structure are completely covered with a SiOC coating layer; and (ii) At least one of the silicon-based fine particles contained in the SiOC structure is covered with a SiOC coating layer.
  • the form of coating the silicon-based fine particles with the SiOC coat layer can be confirmed by observing with an electron microscope such as SEM.
  • Specific examples of the form of the SiOC structure observed in this way include the form observed in the SEM photographs shown in FIGS. 2A and 3. More specifically, in the SiOC structure according to the first aspect of the present invention, at least one silicon-based fine particle is coated with the SiOC coat layer, as observed in the SEM photographs of FIGS. 2A and 3. It is preferable that a plurality of secondary particles are formed by the method, and the plurality of secondary particles are connected to each other via the SiOC coat layer.
  • the SiOC structure When the SiOC structure exhibits a form in which silicon-based fine particles are covered with the SiOC coating layer and connected to each other through the SiOC coating layer, the SiOC structure has excellent performance as an active material for negative electrode. This is because it can be expected to improve the capacity retention rate and the Coulomb efficiency in the secondary battery.
  • the silicon-based fine particles and the SiOC coating layer are preferably chemically bonded to each other.
  • the SiOC structure in which the silicon-based fine particles and the SiOC coat layer are chemically bonded to each other can be produced by the method described later. More specifically, a predetermined functional silane compound is hydrolyzed using an acidic catalyst and polycondensed in the presence of silicon-based fine particles to form a coating layer containing a silicon-containing polymer around the silicon-based fine particles. By doing so, a composite of silicon-based fine particles / silicon-containing polymer is obtained.
  • the surface of the silicon-based fine particles and the silicon-containing fine particles produced by the polycondensation reaction are contained.
  • a state in which the polymer is chemically bonded is developed.
  • the silicon-based fine particles/silicon-containing polymer composite is heat-treated under a predetermined condition to convert the coating layer into a ceramic to be converted into a SiOC structure.
  • the structure in which the surface and the silicon-containing polymer are chemically bonded can be maintained even after the silicon-based fine particle / silicon-containing polymer composite is converted into the SiOC structure.
  • the silicon-based fine particles and the SiOC coat layer are connected by a chemical skeleton generated by the formation of the silicon-containing polymer.
  • a chemical skeleton include chemical skeletons containing Si—O—C, Si—O, Si—O—Si and the like.
  • the BET specific surface area of the SiOC structure needs to be 20 m 2 /g or less.
  • the lower limit of the BET specific surface area of the SiOC structure is not particularly limited, but may be, for example, 1 m 2 /g, that is, the BET specific surface area may be in the range of 1 to 20 m 2 /g. Good.
  • the SiOC structure has a structural portion in which at least one silicon-based fine particle is completely covered with the SiOC coat layer.
  • the SiOC structure according to the first aspect of the present invention has a smooth and uniform surface as a whole without being roughened even after being subjected to a physical treatment such as a crushing treatment. It leads to being able to hold.
  • the BET specific surface area of the SiOC structure is preferably 15 m 2 /g or less, more preferably 10 m 2 /g or less.
  • the range of the surface area is preferably 1 to 15 m 2 /g, more preferably 1 to 10 m 2 /g.
  • the BET specific surface area means a specific surface area according to the Brunauer-Emmett-Teller (BET) method which is well known to those skilled in the art.
  • the cumulative 10% particle size (D10), the cumulative 50% particle size (D50), and the cumulative value obtained by the laser diffraction/scattering particle size distribution measurement method are used.
  • the 90% particle size (D90) satisfies the conditions of 1 nm ⁇ D50 ⁇ 990 ⁇ m and D90/D10 ⁇ 13.0.
  • the cumulative 10% particle size (D10), the cumulative 50% particle size (D50, so-called median diameter), and the cumulative 90% particle size (D90) are laser diffraction scattering techniques that are well known in the field of particle size distribution measurement technology. It is a particle size that can be measured and calculated by the formula particle size distribution measurement method. These particle sizes are not particularly limited, but can be measured using a commercially available laser diffraction / scattering type particle size distribution measuring device (for example, MT-3300EX II manufactured by Microtrac Bell).
  • the cumulative 50% particle size (D50) is preferably 500 nm ⁇ D50 ⁇ 100 ⁇ m, more preferably 500 nm ⁇ D50 ⁇ 50 ⁇ m, and even more preferably 500 nm ⁇ D50 ⁇ .
  • the conditions of 20 ⁇ m, and in some cases 1 ⁇ m ⁇ D50 ⁇ 20 ⁇ m, 2 ⁇ m ⁇ D50 ⁇ 18 ⁇ m, 2 ⁇ m ⁇ D50 ⁇ 17 ⁇ m, 3 ⁇ m ⁇ D50 ⁇ 16 ⁇ m, 4 ⁇ m ⁇ D50 ⁇ 16 ⁇ m may be satisfied.
  • the cumulative 50% particle size (D50) and the cumulative 90% particle size (D90) are preferably 2.0 ⁇ D90 / D10 ⁇ 12.0. More preferably 2.0 ⁇ D90/D10 ⁇ 11.0, even more preferably 2.0 ⁇ D90/D10 ⁇ 10.0, particularly preferably 2.0 ⁇ D90/D10 ⁇ 9.5, for example, 2. 0 ⁇ D90 / D10 ⁇ 9.0, 2.0 ⁇ D90 / D10 ⁇ 8.5, 2.5 ⁇ D90 / D10 ⁇ 8.0, 2.5 ⁇ D90 / D10 ⁇ 7.0, 3.0 ⁇
  • the condition of D90/D10 ⁇ 7.0 and 3.0 ⁇ D90/D10 ⁇ 6.0 may be satisfied in some cases.
  • the cumulative 10% particle size (D10), the cumulative 50% particle size (D50, so-called median diameter), and the cumulative 90% particle size (D90) are as described above. When these conditions are satisfied, a relatively uniform particle size distribution is exhibited, and when the SiOC structure is used as a negative electrode material, good battery characteristics can be realized.
  • the cumulative 10% particle diameter (D10), the cumulative 50% particle diameter (D50, so-called median diameter), and the cumulative 90% particle diameter (D90) are as described above.
  • the volume-based average particle diameter in the particle size distribution represented by the frequency (%) may be in the range of 1 nm to 990 ⁇ m, although it is not particularly limited as long as the condition (1) is satisfied.
  • the average particle size is preferably in the range of 500 nm to 100 ⁇ m, more preferably 1 ⁇ m to 50 ⁇ m, even more preferably 1 ⁇ m to 20 ⁇ m, and particularly preferably 1 ⁇ m to 15 ⁇ m. It may be.
  • the average particle size is the same as the cumulative 10% particle size (D10), the cumulative 50% particle size (D50, so-called median size), and the cumulative 90% particle size (D90). It can be measured by a laser diffraction / scattering method using a measuring device.
  • the elemental composition of the SiOC structure according to the first aspect of the present invention is not particularly limited, but the SiOC structure is based on the total mass of the SiOC structure, for example, in the range of 50% by mass to 90% by mass. Si, O in the range of 5% by mass to 35% by mass, and C in the range of 2% by mass to 35% by mass may be contained as main constituent elements. Further, in some embodiments, the SiOC structure according to the first aspect of the present invention is Si in the range of 60% by mass to 90% by mass and 10% by mass to 10% by mass based on the total mass of the SiOC structure.
  • the SiOC structure according to the first aspect of the present invention may contain other elements as constituent elements in addition to Si, O and C.
  • R 1 is a hydrogen, a hydroxyl group, or a substituted or unsubstituted hydrocarbon having 1 to 45 carbon atoms, and in the hydrocarbon having 1 to 45 carbon atoms, any hydrogen may be replaced with a halogen.
  • Any —CH 2 — may be replaced with —O—, —CH ⁇ CH—, cycloalkylene or cycloalkenylene
  • X 1 is a halogen, an alkyloxy having 1 to 6 carbon atoms, or an acetoxy group.
  • n is an integer from 0 to 3.
  • a method for producing a SiOC structure hereinafter, sometimes referred to as “a method for producing a SiOC structure”
  • a method for producing a SiOC structure which includes converting into a SiOC structure.
  • the silane compound represented by the general formula (I) is hydrolyzed as the hydrolyzable silane compound. Then, the obtained hydrolyzate is polycondensed in the presence of the silicon-based fine particles to coat at least one silicon-based fine particle with a coating layer containing at least one silicon-containing polymer. / Silicon-containing polymer composite is produced.
  • R 1 is a hydrocarbon having 1 to 10 carbon atoms, and there are three. It is possible to adopt a mode in which X 1 is independently halogen, alkyloxy having 1 to 6 carbons, or acetoxy.
  • the silane compound represented by the following general formula (II) may be adopted as the silane compound represented by the general formula (I).
  • the substituent of the substituted alkyl group is halogen, alkyl having 1 to 10 carbons, alkenyl having 2 to 10 carbons, alkoxy having 1 to 5 carbons, phenyl or naphthyl.
  • Aromatic groups such as
  • examples of the silane compound represented by the general formula (I) include organotrichlorosilane and organotrialkoxysilane. More specifically, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, trimethoxy(propyl)silane, n-butyltriethoxysilane, isobutyltrimethoxysilane, n-pentyltriethoxysilane, n-hexyltrimethoxysilane, isooctyltriethoxysilane, decyltrimethoxysilane, methyldimethoxyethoxysilane, methyldiethoxymethoxysilane, 2-chloroethyltriethoxysilane, methoxymethyltriethoxysilane, methylthiomethyltriethoxysilane, methoxy Substi
  • the silane compound represented by the general formula (I) preferably contains at least one silane compound selected from the group consisting of methyltrimethoxysilane and phenyltrimethoxysilane.
  • other types of silane compounds such as dialkoxydialkylsilane may be used in addition to or in place of the above-mentioned organotrichlorosilane or organotrialkoxysilane.
  • the solvent constituting the reaction liquid in step (p) is not particularly limited as long as it promotes hydrolysis/polycondensation of the silane compound. Specifically, it may contain water to assist the hydrolysis of the silane compound, but in addition to water, alcohols such as methanol, ethanol and 2-propanol, ethers such as diethyl ether, acetone and methyl ethyl ketone, etc. Examples thereof include organic solvents containing aromatic hydrocarbon solvents such as ketones, hexane, DMF and toluene. These may be used alone or in combination of two or more.
  • the acidic catalyst is not an essential component, but can be used in some cases in order to preferably control the hydrolysis and / or polycondensation reaction.
  • the acidic catalyst either an organic acid or an inorganic acid can be used.
  • organic acids include formic acid, acetic acid, propionic acid, oxalic acid, and citric acid
  • inorganic acids include hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid.
  • hydrochloric acid and / or acetic acid is preferably used because the hydrolysis reaction and the subsequent polycondensation reaction can be easily controlled, the cost is low, and the treatment after the reaction is easy.
  • a halogenated silane such as trichlorosilane
  • an acidic aqueous solution is formed in the presence of water, and "acidic conditions" in which hydrolysis and polycondensation of the silane compound can proceed are realized.
  • the halogenated silane is used as described above, the hydrolysis and the polycondensation reaction proceed without adding an acidic catalyst to the reaction system, so that it is not necessary to add a catalyst separately. That is, in such a case, the acidic catalyst is not an essential element in the step (p) as described above.
  • silicon-based fine particles As for the silicon-based fine particles, as described above, it is a concept that includes silicon fine particles consisting essentially of only silicon, and fine particles consisting of a compound containing silicon (silicon) in the atomic composition (for example, silica, a silicon-containing metal compound), It can be used without particular limitation within the scope of this concept.
  • silicon-based fine particles silicon fine particles substantially composed of only silicon can be preferably used, and in particular, since various silicon powders are commercially available, it is convenient to use them.
  • the conditions such as the average particle size are as described above.
  • step (p) (Conditions for hydrolysis and polycondensation reaction) Next, the reaction conditions for hydrolysis and polycondensation in step (p) will be described.
  • the ratio of the silane compound in the reaction solution is not particularly limited, but is, for example, about 0.1 part by mass to about 30 parts by mass, preferably about 0.1 part by mass with respect to 100 parts by mass of the reaction solution. To about 25 parts by weight, more preferably about 0.5 to about 20 parts by weight. With such a range as a guide, it may be appropriately set together with the addition ratio of the silicon-based fine particles in view of the atomic composition ratio to be realized in the finally formed SiOC structure.
  • the addition ratio of the silicon-based fine particles is not particularly limited, and may be appropriately set together with the silane compound in consideration of the elemental composition ratio desired to be realized in the finally produced SiOC structure and the desired battery characteristics. ..
  • the addition ratio of the silicon-based fine particles is, for example, about 0.1 part by mass to about 70 parts by mass, preferably about 1.0 part by mass to about 60.0 parts by mass, more preferably about 100 parts by mass of the silane compound. It is about 5.0 parts by mass to about 55 parts by mass, particularly preferably about 10 parts by mass to about 50 parts by mass.
  • the ratio of the solvent contained in the reaction solution at the time of the hydrolysis or polycondensation is not particularly limited as long as the hydrolysis or polycondensation reaction suitably proceeds, but 100 parts by mass of the silane compound.
  • about 50 parts by mass to about 2500 parts by mass preferably about 100 parts by mass to about 2400 parts by mass, more preferably about 100 parts by mass to about 2300 parts by mass, particularly preferably about 150 parts by mass to about 2200 parts by mass.
  • the range of parts by mass can be mentioned.
  • the ratio of the solvent contained in the reaction liquid during the hydrolysis reaction is, for example, about 50 parts by mass to about 1500 parts by mass, preferably about 100 parts by mass, relative to 100 parts by mass of the silane compound.
  • Parts to about 1000 parts by mass, more preferably about 150 parts by mass to about 800 parts by mass, particularly preferably about 150 parts by mass to about 600 parts by mass, and the ratio of the solvent contained in the reaction solution at the polycondensation reaction is the above.
  • 100 parts by mass of the silane compound for example, about 400 parts by mass to about 2500 parts by mass, preferably about 500 parts by mass to about 2400 parts by mass, more preferably about 550 parts by mass to about 2300 parts by mass, particularly preferably about 600 parts by mass. It may be about 2200 parts by mass, and in some cases, about 700 parts by mass to about 2000 parts by mass.
  • water may be used as the solvent as described above, or a mixed solvent of water and another solvent (alcohol, organic solvent, etc.) may be used.
  • the ratio thereof may be appropriately adjusted so as to obtain a desired hydrolysis or polycondensation reaction, and the ratio is not particularly limited, but is not particularly limited, but the above-mentioned silane compound 100
  • parts by mass for example, about 0.02 parts to about 15 parts by mass, preferably about 0.02 parts to about 10 parts by mass, more preferably about 0.02 to about 8 parts by mass, and in some cases about 0 parts. It is about 7 parts by mass from .04 parts by mass and about 6 parts by mass from about 0.08 parts by mass.
  • each component and the method of addition are not particularly limited, but generally, for example, a solvent (catalyst solution in which a solvent and a catalyst are mixed) is charged into a reaction vessel, and the atmosphere in the reaction vessel is set to a predetermined value in some cases. Gas atmosphere (for example, inert gas such as nitrogen, argon, helium, etc.), and then add (drop) the above silane compound to the solution in the reaction vessel under stirring, and stir the reaction solution or In the stationary state, the hydrolysis and / or polycondensation reaction can be carried out at a predetermined reaction temperature and reaction time. Preferred embodiments are described in detail below for the order of addition of each component and the method of hydrolysis / polycondensation reaction.
  • reaction temperature of hydrolysis and / or polycondensation is not particularly limited, but is, for example, about -20 ° C to about 80 ° C, preferably about 0 ° C to about 70 ° C, and in some cases about 0 ° C to about. 40° C., about 10° C. to about 30° C., for example, room temperature (eg room temperature; about 20° C. to 25° C.).
  • the reaction time is also not particularly limited, and examples thereof include about 0.5 hours to about 100 hours, and in some cases, about 1 hour to about 80 hours, and about 1 hour to about 6 hours.
  • the pH of the reaction solution may be appropriately adjusted so that the hydrolysis and polycondensation reaction of the silane compound can proceed favorably, and is not particularly limited, but is usually in the range of 0.8 to 12 It may be selected according to the shape and properties of a specific silane compound or a desired organosilicon compound (polysilsesquioxane) product.
  • the pH of the reaction solution can be adjusted by using an acid containing the above-mentioned acidic catalyst.
  • step (p) first, the hydrolysis reaction of the silane compound is allowed to proceed under predetermined conditions, and then the polycondensation reaction is carried out in the presence of the silicon-based fine particles to obtain some of the present invention.
  • a predetermined silicon-based fine particle / silicon-containing polymer composite according to the embodiment can be synthesized. More specifically, in some embodiments, the following (p-1) to (p-3) may be performed in the step (p).
  • step (P-1) adding a silane compound represented by the general formula (I) to an acidic solution having a pH of 3 to 6 to hydrolyze the silane compound;
  • P-2) Add silicon-based fine particles or a dispersion thereof to the reaction solution obtained in step (p-1);
  • step (P-3) By adding a predetermined amount of an acid or a solution thereof to the mixed solution obtained in the step (p-2), the pH of the mixed solution is 2 or less (in some cases, 1.5 or less, for example, 0 or less). .9 to 2.0, 0.9 to 1.5), and allowing the mixed solution to stand for a predetermined time at a predetermined temperature to promote polycondensation of the silane compound and To produce a silicon-containing polymer composite.
  • (P-1') A silane compound represented by the general formula (I) is added stepwise to an acidic solution having a pH of 3 to 6 under stirring conditions, and the mixture is stirred under stirring conditions for a predetermined time at a predetermined temperature. Hydrolyzing the silane compound; (P-2′) Silicon fine particles or a dispersion thereof is added to the reaction liquid obtained in the step (p-1′) to uniformly disperse the silicon fine particles or a dispersion thereof in the reaction liquid.
  • the pH of the mixed solution is 2 or less (and 1.5 or less in some cases, For example, it is adjusted to 0.9 to 2.0, 0.9 to 1.5), and then the mixed solution is allowed to stand for a predetermined time at a predetermined temperature to promote polycondensation of the silane compound, To generate a silicon-based fine particle / silicon-containing polymer composite.
  • an acetic acid solution having a predetermined concentration (preferably an aqueous acetic acid solution) is used as the “acidic solution having a pH of 3 to 6” in the step (p-1) or (p-1′).
  • the acetic acid concentration range may be, for example, about 0.001M to about 0.1M concentration, preferably about 0.005M to about 0.09M concentration.
  • a hydrochloric acid solution of a predetermined concentration preferably a hydrochloric acid aqueous solution
  • the concentration range of hydrochloric acid is not particularly limited, but may be, for example, about 10% by mass to about 40% by mass, preferably about 20% by mass to about 40% by mass.
  • a hydrolyzate can be produced by hydrolyzing the silane compound in an acidic aqueous medium, and the hydrolyzate of the silane compound can be produced.
  • the decomposition reaction can be carried out, for example, by dropping the silane compound into an acidic aqueous medium.
  • the hydrolysis reaction rate is higher than the polycondensation reaction rate so that the desired hydrolysis sufficiently proceeds, and the hydrolysis reaction predominantly proceeds. It employs acidic conditions.
  • the pH range for realizing such acidic conditions varies depending on the type of the silane compound used as the raw material, but can be adjusted to pH 3 to 6, preferably pH 4 to 6, normally.
  • the degree of acidity affects the equilibrium of hydrolyzate formation, the reaction time, the amount of partial condensate, the number of condensations, etc., but does not significantly affect the particle size.
  • the above-mentioned acidic catalyst may be used, but the hydrolysis reaction and the subsequent polycondensation reaction can be easily performed by controlling, Acetic acid is most preferably used because it is easy to obtain and adjust the pH.
  • the pH value is about 5.0 to 5.8.
  • silicon-based fine particles (preferably) with respect to the reaction solution containing the hydrolyzate obtained in the step (p-1).
  • a dispersion liquid of silicon-based fine particles prepared in advance) is added, and the obtained mixed solution is stirred, for example, for 10 seconds to 2 hours, preferably for 1 minute to 1.5 hours.
  • step (p-3) or (p-3') a predetermined amount of acid or acid solution is added to the mixed solution obtained in step (p-2) or (p-2'). After stirring the mixed solution for, for example, 1 to 30 seconds, preferably about 1 to 15 seconds, for example, 2 hours to 36 hours, preferably 4 hours to 24 hours, more preferably about 4 hours to 12 hours, without stirring.
  • the hydrolyzate produced in the step (p-1) is polycondensed in the presence of the silicon-based fine particles, and the silicon-based fine particles having a predetermined structure according to some embodiments of the present invention / Obtain a silicon-containing polymer composite.
  • the reaction solution is polycondensed with the hydrolyzate of the silane compound in the presence of silicon-based fine particles in a stationary state without stirring.
  • the reaction proceeds, at least one silicon-based fine particle is uniformly coated with a coat layer containing a silicon-containing polymer, and a silicon-based fine particle / silicon-containing polymer composite (more specifically, shown in FIG. 1). Structure) is produced, which ensures the production of a SiOC structure with a defined structure according to some embodiments of the invention as a final product.
  • the silicon-based fine particle / silicon-containing polymer composite produced in the step (p) contains a coat layer containing the silicon-containing polymer as a constituent element.
  • the silicon-containing polymer is produced through hydrolysis and polycondensation of the above predetermined hydrolyzable silane compound.
  • the silicon-containing polymer may more specifically include at least one polymer selected from the group consisting of polycarbosilanes, polysilanes, polysiloxanes, and polysilsesquioxanes. ..
  • the polycarbosilane contains at least one of the structural units represented by the following (1) to (3).
  • R 1 R 2 SiC 2 (2) (R 1 Si (CH 2 ) 1.5 ) (3) (R 1 R 2 R 3 Si (CH 2 ) 0.5 )
  • R 1 , R 2 and R 3 are each independently hydrogen or a hydrocarbon having 1 to 20 carbon atoms (preferably 1 to 6 carbon atoms).
  • hydrocarbons include alkyl such as methyl, ethyl, propyl and butyl; alkenyl such as vinyl and allyl; aryl such as phenyl.
  • the hydrocarbon may be optionally substituted with a heteroatom such as silicon, nitrogen or boron.
  • the polycarbosilane may be optionally substituted with various metal groups such as aluminum, chromium and titanium. Since various kinds of polycarbosilane substituted with such a metal group are known in the prior art together with the synthesis process thereof, in the method for producing a SiOC structure according to the second aspect of the present invention, Known synthesis processes may be combined.
  • examples of the polysilane that can be used as the silicon-containing polymer include various polysilanes containing at least one of the structural units shown in (4) to (6) below.
  • the polysilane of the silicon-containing polymer may include a that (PhViSi), and (Me 3 Si) at least one structural unit selected from the group consisting of.
  • Me represents methyl
  • Ph represents phenyl
  • Vi represents vinyl.
  • the polysilane may be substituted by any metal group, that is, it may contain a predetermined number of any metal-Si repeating units. Examples of suitable metal groups include aluminum, chromium and titanium. ..
  • examples of the polysiloxane that can be adopted as the silicon-containing polymer include various polysiloxanes containing the structural units shown in (7) below.
  • (7) (R 1 R 2 R 3 SiO 0.5 ) w (R 4 R 5 SiO) x (R 6 SiO 1.5 ) y (SiO 4/2 ) z
  • R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are each independently hydrogen or a carbon number of 1 to 20 (preferably 1 to 20) as described for R 1 , R 2 and R 3. It is a hydrocarbon having 1 to 6 carbon atoms.
  • siloxane units that may be employed in some embodiments of the present invention include (MeSiO 1.5 ), (PhSiO 1.5 ), (ViSiO 1.5 ), (HSiO 1.5 ), (PhMeSiO ). ), (MeHSiO), (PhViSiO ), (MeViSiO), (Ph 2 SiO), (Me 2 SiO), (Me 3 SiO 0.5), (Ph 2 ViSiO 0.5), (Ph 2 HSiO 0. 5 ), (H 2 ViSiO 0.5 ), (Me 2 ViSiO 0.5 ), (SiO 4/2 ) and the like.
  • Me indicates methyl
  • Ph indicates phenyl
  • Vi indicates vinyl.
  • polysilsesquioxanes that can be employed as the silicon-containing polymer mainly include polysilsesquioxanes containing (RSiO 3/2 ) X units.
  • R is a saturated or unsaturated, straight-chain, branched or cyclic hydrocarbon group, for example, —C n H 2n+1 (n is an integer in the range of 1 to 20), and more specifically.
  • R can contain therein heteroatoms, in particular nitrogen or halogen, preferably R is methyl, ethyl, propyl or phenyl. R may be a combination of two or more different groups.
  • x is the number of repeating units, is an integer of 1 or more, and can be any integer selected from the range of 4 to 10,000, for example.
  • the silicon-containing polymer which is the main component of the coating layer that coats the silicon-based fine particles, contains polysilsesquioxane.
  • the silicon-containing polymer is substantially made of polysilsesquioxane and at least one silicon-based by a coat layer thus composed of the silicon-containing polymer composed of polysilsesquioxane. It is preferable that a silicon-based fine particle / silicon-containing polymer composite coated with fine particles is produced in the step (p).
  • the silicon-based fine particle / silicon-containing polymer composite having such a structure can be subjected to any trifunctional organosilane (organotrialkoxysilane, organotrichlorosilane, etc.) within the above-mentioned conditions and procedures. It can be obtained by hydrolysis and polycondensation.
  • organosilane organotrialkoxysilane, organotrichlorosilane, etc.
  • polysilsesquioxane examples include ladder-type polysilsesquioxane, cage-type polysilsesquioxane such as POSS (T R 8 ), incomplete cage-type polysilsesquioxane, and other types of polysilsesquioxane. It may contain at least one selected from the group consisting of. Since various types of polysilsesquioxanes are known along with their methods of synthesis, those methods of synthesis can be utilized in some embodiments of the present invention (chemistry and applications of silsesquioxane materials). Development, CMC Publishing, 2013 popular edition, etc.).
  • the silicon-containing polymer has a polysilsesquioxane structure represented by the following general formulas (III), (IV), (V), and (VI), respectively. It may contain at least one selected from the group consisting of polysilsesquioxane having.
  • R 1 and R 4 are each independently selected from the group consisting of substituted or unsubstituted alkyl having 1 to 45 carbon atoms, substituted or unsubstituted aryl, and substituted or unsubstituted arylalkyl,
  • any hydrogen may be replaced by halogen
  • any —CH 2 — may be replaced by —O—, —CH ⁇ CH—, cycloalkylene or cycloalkenylene.
  • R 2 , R 3 , R 5, and R 6 are each independently a group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 45 carbon atoms, a substituted or unsubstituted aryl group, and a substituted or unsubstituted arylalkyl group.
  • halogen is understood literally and indicates fluorine, chlorine, bromine, iodine and the like, but among them, fluorine or chlorine is preferable.
  • the method for producing a SiOC structure according to the second aspect of the present invention may further include at least one of the following steps.
  • the liquid fraction is separated and removed by a method such as the above, and the obtained solid fraction is subjected to the step (q) as an object to be heat treated.
  • filtration separation for example, pressure filtration
  • solid-liquid separation solvent distillation
  • centrifugation or decantation e.g., solvent distillation, centrifugation or decantation.
  • the liquid fraction is separated and removed by a method such as the above, and the obtained solid fraction is subjected to the step (q) as an object to be heat treated.
  • Various general-purpose techniques are known to those skilled in the art for such a method of separating a solid
  • the heat treatment conditions in the embodiment of the step (q) may be appropriately set in consideration of the type and capacity of the heat treatment apparatus used, but for example, in a non-oxidizing atmosphere, 0.5°C/min to 200°C/ Min, preferably 0.5°C/min to 100°C/min, more preferably 1°C/min to 50°C/min, even more preferably 1°C/min to 30°C/min, particularly preferably 2°C/min. It is heated to a temperature in the range of 400 ° C. to 1800 ° C., preferably 600 ° C. to 1400 ° C., more preferably 900 ° C. to 1300 ° C. at a heating rate of about 10 ° C./min, and the temperature is 5 minutes to 20 hours.
  • the heat treatment may be carried out in the range of preferably 30 minutes to 10 hours, more preferably 1 hour to 8 hours.
  • the heat treatment conditions such as the heating rate, the heat treatment temperature, and the heating time, the properties of the polysilsesquioxane used as a raw material, the physical properties and other properties of the desired SiOC structure, and the productivity and economy are taken into consideration. There is no particular limitation as long as the minimum necessary heat treatment conditions are appropriately selected.
  • the “non-oxidizing gas atmosphere” in the present disclosure includes an inert gas atmosphere, a reducing atmosphere, and a mixed atmosphere in which these atmospheres are used in combination.
  • the inert gas atmosphere include inert gases such as nitrogen, argon, and helium, and these inert gases may be used alone or in combination of two or more.
  • the inert gas may be any commonly used gas, but a high-purity standard gas is preferable.
  • the reducing atmosphere also includes an atmosphere containing a reducing gas such as hydrogen.
  • a mixed gas atmosphere of 2 volume% or more of hydrogen gas and an inert gas can be mentioned.
  • the hydrogen gas atmosphere itself may be used as the reducing atmosphere in some cases.
  • the environment of the non-oxidizing atmosphere can be created by replacing the atmosphere in the heat treatment furnace or supplying the predetermined gas into the furnace.
  • the gas flow rate may be appropriately adjusted to an appropriate range according to the specifications of the heat treatment furnace to be used (for example, the shape and size of the furnace), and is not particularly limited.
  • the capacity of the furnace can be about 5% to 100% / min, preferably about 5 to 30% / min.
  • the gas flow rate (purge amount) is, for example, about 50 mL to 1 L/min, preferably about 100 mL to 500 mL/min. can do.
  • the SiOC structure according to the embodiment of the present invention is manufactured by using the heat treatment furnace having an inner volume of about 40 L, the gas flow rate (purge amount) is, for example, about 10 to 15 L/min. can do.
  • Examples of the heat treatment furnace that can be used in the step (q) include a rotary kiln type, a roller harsher kiln type, a batch kiln type, a pusher kiln type, a mesh belt kiln type, a carbon furnace, a tunnel kiln type, and a shuttle.
  • Various types of heat treatment furnaces such as a kiln type and a trolley lifting type kiln type can be used. These heat treatment furnaces may be used alone or in combination of two or more. When two or more types are combined, each heat treatment furnace may be connected in series or in parallel.
  • the method for producing a SiOC structure according to the second aspect of the present invention may further include additional steps such as crushing and / or classifying the SiOC structure obtained by the heat treatment in the above step (q). Good.
  • the crushing method and the classification method that can be used in these steps are not particularly limited, and for example, various known methods may be adopted, and a mortar, various crushers, a sieve, a cyclone classification device, and the like can be used.
  • a composition for a negative electrode contains the SiOC structure as a negative electrode active material.
  • a method for producing a composition for a negative electrode is also disclosed. The method for producing the negative electrode composition includes obtaining the negative electrode composition by using the SiOC structure as a negative electrode active material.
  • the negative electrode composition may further include additional components such as a carbon-based conductive additive and/or a binder described below.
  • carbon-based substances that function as carbon-based conductive aids include carbon-based substances such as graphite, carbon black, fullerene, carbon nanotubes, carbon nanoforms, pitch-based carbon fibers, polyacrylonitrile-based carbon fibers, and amorphous carbon. Are preferred. These carbon-based substances may be used alone or as a mixture of two or more kinds.
  • any binder that can be used in a secondary battery is sufficient, for example, carboxymethyl cellulose, polyacrylic acid, alkaline acid, glucomannan, amylose, saccharose and derivatives thereof. , Polymers, and each alkali metal salt, as well as polyimide resin and polyimide amide resin. These binders may be used alone or as a mixture of two or more kinds.
  • the binder for example, by improving the binding property between the current collector and the negative electrode active material, improving the dispersibility of the negative electrode active material, and improving the conductivity of the binder itself.
  • An additive capable of imparting a function can be added if necessary. Specific examples of such additives include styrene-butadiene/rubber-based polymers and styrene-isoprene/rubber-based polymers.
  • the method for producing the negative electrode composition is as follows. It may include step (r). Step (r): mixing the SiOC structure according to the embodiment of the present invention with the additional component, or compounding or coating the SiOC structure with the additional component.
  • the SiOC structure and the carbon-based material are subjected to a mechanical mixing method using various stirrers, stirring blades, mechanofusions, ball mills, vibration mills, and the like.
  • a dispersion treatment by a thin film rotation method that can be realized by using a thin film rotation type high-speed mixer [Filmix (registered trademark) series] manufactured by PRIMIX Corporation is preferably used.
  • a thin film rotation type high-speed mixer [Filmix (registered trademark) series] manufactured by PRIMIX Corporation is preferably used.
  • one of these mechanical mixing methods and dispersion methods may be used alone to obtain a negative electrode composition, or stepwise.
  • the negative electrode composition may be obtained by combining a plurality of methods.
  • step (r) the SiOC structure according to the embodiment of the present invention and optionally a carbon-based conductive auxiliary agent are added in predetermined amounts to an aqueous solution of a binder having a concentration of about 1 to 5% by mass, and a stirrer is used. Or other mixers may be used for mixing. Further, water may be further added to the obtained mixture as necessary so as to have a predetermined solid content concentration, and further stirring may be continued to obtain a slurry-like composition, which may be used as a negative electrode composition. Further, a composition obtained by subjecting the slurry-like composition to a dispersion treatment by the above-mentioned thin film swirling method may be used as a negative electrode composition.
  • the SiOC structure and the carbonaceous material may be mixed in an arbitrary ratio depending on the purpose and in order to obtain desired battery characteristics.
  • the method for producing the composition for a negative electrode according to the fourth aspect of the present invention may optionally include, prior to the above steps, each step that can be included in the method for producing the SiOC structure. Embodiments including the above steps are also expressly disclosed herein.
  • the negative electrode is disclosed. Furthermore, according to a sixth aspect of the present invention, a method for producing a negative electrode is also disclosed, and in some embodiments of the present invention, the negative electrode is the method for producing a negative electrode according to the sixth aspect of the present invention. It can be acquired. The method includes obtaining a negative electrode using the SiOC structure or the composition for a negative electrode. An example of a specific manufacturing process is shown below.
  • the negative electrode in some embodiments of the present invention is specifically manufactured by using the SiOC structure as the negative electrode active material or the negative electrode composition containing the SiOC structure as the negative electrode active material.
  • the negative electrode may be manufactured based on a method of molding the above-mentioned SiOC structure or the composition for a negative electrode into a certain shape, or a method of applying it to a current collector such as a copper foil.
  • the method for molding the negative electrode is not particularly limited, and any method may be used, and various known methods may be used.
  • a negative electrode composition prepared in advance, a doctor blade method, a slurry on a current collector such as a rod-shaped body, a plate-shaped body, a foil-shaped body, a reticulated body mainly composed of copper, nickel, stainless steel, or the like.
  • Direct coating may be performed by a method such as a casting method or a screen printing method.
  • the negative electrode composition is separately cast on a support, the negative electrode composition film formed on the support is peeled off, and the peeled negative electrode composition film is laminated on the current collector to form a negative electrode.
  • An electrode plate may be formed.
  • the negative electrode composition coated on the current collector or the support is subjected to an air-drying treatment or a drying treatment step at a predetermined temperature, and / or, if necessary, a pressing treatment or a punching treatment or the like.
  • the final negative electrode body may be obtained by performing the processing step according to.
  • the method for producing the negative electrode according to the sixth aspect of the present invention includes each step that can be included in the above-mentioned method for producing a SiOC structure and the method for producing a negative electrode composition prior to the above-mentioned step. It may optionally be included, and those embodiments are also expressly disclosed herein. In addition, it is needless to say that the form of the negative electrode is merely an example, and the form of the negative electrode is not limited to these and may be provided in other forms.
  • a secondary battery is provided. Furthermore, according to the eighth aspect of the present invention, a method for manufacturing a secondary battery is also provided. The method includes manufacturing a secondary battery by using the above negative electrode.
  • the secondary battery according to the seventh aspect of the present invention is provided with at least one negative electrode according to the embodiment of the present invention.
  • the secondary battery includes at least one negative electrode according to the embodiment of the present invention and functions as a secondary battery, other components and structures are not particularly limited, but more specifically. Includes at least one positive electrode and at least one separator in addition to the above negative electrode.
  • the secondary battery of the present invention has a laminated structure in which the negative electrode of the present invention and, when a plurality of positive electrodes and separators are provided, the constituent elements are alternately laminated in the order of positive electrode / separator / negative electrode / separator. May be adopted. Alternatively, a laminated structure in which the positive electrode and the negative electrode are wound in a coil shape via a separator may be adopted.
  • the secondary battery of the present invention may include an electrolytic solution or a solid electrolyte.
  • the secondary battery can be specifically a secondary battery obtained by the method for manufacturing a secondary battery according to an eighth aspect of the present invention.
  • the secondary battery may be appropriately designed in consideration of a desired application, function, etc., and its configuration is not particularly limited, but the present invention can be implemented by referring to the configuration of an existing secondary battery.
  • a secondary battery can be constructed by using the negative electrode according to the embodiment.
  • the type of the secondary battery of the present invention is not particularly limited as long as the above negative electrode can be applied, and examples thereof include a lithium ion secondary battery and a lithium ion polymer secondary battery. As demonstrated in the following examples, these batteries can be said to be a particularly preferable embodiment because they can exhibit desired effects.
  • an embodiment in which the secondary battery and the method for manufacturing the secondary battery are particularly a lithium ion secondary battery will be illustrated.
  • a positive electrode active material composition capable of reversibly occluding and releasing lithium ions, a conductive auxiliary agent, a binder and a solvent are mixed to prepare a positive electrode active material composition.
  • the positive electrode active material composition is directly coated on the metal current collector and dried by various methods to prepare a positive electrode plate. It is also possible to separately cast the positive electrode active material composition on a support, peel off the film formed on the support, and laminate the film on a metal current collector to produce a positive electrode. ..
  • the method for forming the positive electrode is not particularly limited, but it can be formed by using various known methods.
  • a lithium metal composite oxide generally used in the field of the secondary battery can be used.
  • compounds capable of de-inserting lithium ions such as V 2 O 5 , TiS and MoS can also be used.
  • a conductive auxiliary agent may be added, and those generally used in lithium ion batteries can be used. It is preferably an electron conductive material that does not decompose or deteriorate in the manufactured battery. Specific examples include carbon black (acetylene black and the like), graphite fine particles, vapor-grown carbon fibers, and a combination of two or more of these.
  • the binder include vinylidene fluoride/propylene hexafluoride copolymer, polyvinylidene fluoride (PVDF), polyacrylonitrile, polymethylmethacrylate, polytetrafluoroethylene and mixtures thereof, styrene butadiene rubber type. Examples include, but are not limited to, polymers.
  • the solvent examples include, but are not limited to, N-methylpyrrolidone, acetone, water and the like.
  • the contents of the positive electrode active material, the conductive additive, the binder and the solvent are not particularly limited, but can be appropriately selected with the amounts generally used in lithium ion batteries as a guide. ..
  • the separator interposed between the positive electrode and the negative electrode those generally used in lithium ion batteries may be used, but are not particularly limited, and in consideration of the desired application and function, etc., appropriate Just select it. Those having low resistance to ion transfer of the electrolyte or having excellent electrolyte impregnation ability are preferable. Specifically, it is a material selected from glass fiber, polyester, polyethylene, polypropylene, polytetrafluoride ethylene, polyimide, or a compound thereof, and may be in the form of a non-woven fabric or a woven fabric.
  • a rollable separator made of a material such as polyethylene or polypropylene is used, and in the case of a lithium-ion polymer battery, a separator excellent in organic electrolyte impregnation ability. Is preferably used.
  • Electrolytes include propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methylpropyl carbonate, butylene carbonate, dibutyl carbonate, benzonitrile, acetonitrile, tetrahydrofuran, 2-methyl tetrahydrofuran, ⁇ -butyrolactone, dioxolane, 4 -Methyldioxolane, N, N-dimethylformamide, dimethylacetamide, dimethylsulfoxide, dioxane, 1,2-dimethoxyethane, sulfolane, dichloroethane, chlorobenzene, nitrobenzene, or a mixed solvent thereof, and hexafluoride Lithium phosphate, lithium borate tetrafluoride, antimonium hexafluoride, lithium arsenide hexafluoride, lithium perchlorate, lithium trifluoromethan
  • various non-aqueous electrolytes and solid electrolytes can be used instead of the electrolyte.
  • various ionic liquids to which lithium ions are added can be used, pseudo solid electrolytes in which ionic liquids and fine powders are mixed, lithium ion conductive solid electrolytes, and the like can be used.
  • the above-mentioned electrolytic solution may appropriately contain a compound that promotes stable film formation on the surface of the negative electrode active material.
  • a compound that promotes stable film formation on the surface of the negative electrode active material For example, vinylene carbonate (VC), fluorobenzene, cyclic fluorinated carbonate [fluoroethylene carbonate (FEC), trifluoropropylene carbonate (TFPC), etc.], or chain fluorinated carbonate [trifluorodimethyl carbonate (TFDMC), etc.], Fluorinated carbonates such as trifluorodiethyl carbonate (TFDEC) and trifluoroethylmethyl carbonate (TFEMC) are effective.
  • the cyclic fluorinated carbonate and the chain fluorinated carbonate can also be used as a solvent, such as ethylene carbonate.
  • a separator is arranged between the positive electrode plate and the negative electrode plate as described above to form a battery structure, and the battery structure is wound or folded into a cylindrical battery case or a square battery case.
  • a lithium ion battery may be completed by injecting an electrolytic solution.
  • the battery structure is laminated on a bicell structure, impregnated with an organic electrolytic solution, and the obtained product is placed in a pouch and sealed to form a lithium ion as a secondary battery according to an embodiment of the present invention.
  • a polymer battery may be obtained.
  • the method for manufacturing a secondary battery according to the embodiment of the present invention precedes each step included in the above-mentioned method for manufacturing a SiOC structure, the method for manufacturing a composition for a negative electrode, and the method for manufacturing a negative electrode. It may further include.
  • SEM observation was performed for each material produced in Examples and Comparative Examples.
  • Ultra-high resolution analytical scanning electron microscope SU-70 manufactured by Hitachi High-Technologies Corporation
  • 3D real surface view microscope VE-9800 manufactured by Keyence Corporation were used as SEMs and measured at a predetermined acceleration voltage.
  • the particle size distribution was measured for each SiOC structure and SiOC material produced in Examples 1 to 4 and Comparative Example 1 below, and 10%, 50% and 90% cumulative mass particle size distribution diameters (D10, D50 and D90) was calculated.
  • the method for measuring the particle size distribution is as follows. A small amount of the prepared hydrogenated polysilsesquioxane containing silicon nanoparticles was placed in a beaker, a few drops of water and 0.5% Triton X-100 aqueous solution were added, and an ultrasonic homogenizer US-150 manufactured by Nippon Seiki Co., Ltd. was used. A sample for measurement was prepared by dispersion treatment for 3 minutes. This measurement sample was measured using a laser diffraction/scattering type particle size distribution measuring device MT3300II manufactured by Microtrac Bell Co., Ltd.
  • Negative electrode active materials containing the materials produced in the examples and comparative examples were prepared, and a negative electrode and a lithium ion secondary battery using the negative electrode active materials were subjected to a charge/discharge cycle test as described below to evaluate battery characteristics.
  • the procedure is shown below. Hokuto Denko HJR-110mSM, HJ1001SM8A or HJ1010mSM8A was used, and both charging and discharging were measured at a constant current. At that time, a current value of 0.05 C was adopted so as to be 1/20 of the theoretical capacity per 1 g of the negative electrode active material (SiOC particles).
  • the charge was the capacity until the battery voltage dropped to 0V
  • the discharge was the capacity until the battery voltage reached 1.5V. At the time of switching between charge and discharge, the battery was discharged after being paused in the open circuit for 30 minutes.
  • the reversible capacity is the initial discharge capacity
  • the initial charge/discharge rate is the ratio of the discharge capacity to the charge capacity in the first cycle
  • the capacity maintenance rate after the cycle test is the charge after the cycle for the initial charge amount. Displayed by capacity.
  • Example 1 (MeSiO 0.5 ) (Manufacture of silicon nanoparticles / methylpolysilsesquioxane complex)
  • 100 g of 0.01 M acetic acid aqueous solution and 10 g of silicon nanopowder (manufactured by Sigma-Aldrich Co.; volume-based average particle size is less than 100 nm; particle size is more than 10 nm) are put, and an ultrasonic cleaner is used.
  • a silicon nanoparticle dispersion was prepared.
  • a fired product of the silicon nanoparticles / methylpolysilsesquioxane complex (1) was obtained. Then, the obtained fired product is crushed and pulverized in a mortar for 5 minutes and classified using a stainless steel sieve having openings of 32 ⁇ m to obtain silicon nanoparticles having a maximum particle diameter of 32 ⁇ m/methyl polysilsesquioxy. 18.9 g of a fired product [SiOC structure (1)] powder of the sun composite (1) was obtained. A part of the SiOC structure (1) powder was subjected to SEM observation, particle size distribution measurement, elemental analysis, and BET specific surface area measurement by the above-mentioned method.
  • composition for negative electrode and negative electrode body To 20 g of a 2% by weight aqueous solution of carboxymethyl cellulose, 3.2 g of SiOC particles (3) and 0.4 g of acetylene black manufactured by Denka Co., Ltd. were added and mixed in a flask for 15 minutes using a stirrer, and then the solid content concentration was increased. Distilled water was added so that the concentration was 15% by weight, and the mixture was further stirred for 15 minutes to prepare a slurry composition. This slurry composition was transferred to a thin film swirl type high speed mixer (Filmix 40-40 type) manufactured by Primix Co., Ltd., and stirred and dispersed at a rotation speed of 20 m/s for 30 seconds. The slurry after the dispersion treatment was applied onto a copper foil roll by a doctor blade method so as to have a thickness of 150 ⁇ m.
  • the negative electrode sheet was pressed with a 2t small precision roll press (manufactured by Thunk Metal Co., Ltd.). After pressing, the electrodes were punched with an electrode punching punch HSNG-EP having a diameter of 14.50 mm, and dried under reduced pressure at 80 ° C. for 12 hours or more in a glass tube oven GTO-200 (SIBATA) to prepare a negative electrode body.
  • a 2t small precision roll press manufactured by Thunk Metal Co., Ltd.
  • the electrodes were punched with an electrode punching punch HSNG-EP having a diameter of 14.50 mm, and dried under reduced pressure at 80 ° C. for 12 hours or more in a glass tube oven GTO-200 (SIBATA) to prepare a negative electrode body.
  • a 2032 type coin battery (lithium ion secondary battery) 300 having the structure shown in FIG. 6 was produced.
  • Lithium was used as the positive electrode (lithium counter electrode) 303, a microporous polypropylene film was used as the separator 302, and the negative electrode body was used as the negative electrode (negative electrode material) 301.
  • LiPF6 was dissolved at a ratio of 1 mol/L as the electrolytic solution.
  • a mixed solvent of ethylene carbonate and diethyl carbonate 1: 1 (volume ratio) was used.
  • the battery characteristics of the lithium ion secondary battery were evaluated.
  • As the charge / discharge tester HJ1001SM8A manufactured by Hokuto Denko was used.
  • As charging/discharging conditions both charging and discharging were performed at a constant current of 0.05 C, and the discharge end voltage was 1 mV and the charge end voltage was 1500 mV.
  • Example 2 (MePhSiO 0.5 ) In the production of the silicon nanoparticles / methylpolysilsesquioxane complex (1) in Example 1, 14.4 g (142 mmol) of methyltrimethoxysilane and phenyltrimethoxysilane 7 were used instead of 24.3 g of methyltrimethoxysilane. . Silicon nanoparticles / methylpolysilsesquioxane complex (2) and its calcined product [SiOC structure (2)] powder in the same procedure as in Example 1 except that a mixture of 1 g (36 mmol) was used. Manufactured the body.
  • Example 2 a part of the silicon nanoparticle/methylpolysilsesquioxane composite (2) was subjected to SEM observation, and a part of the SiOC structure (2) powder was added. It was used for SEM observation, particle size distribution measurement, elemental analysis and BET specific surface area measurement by the above method. Further, in the same manner as in Example 1 except that the SiOC structure (1) obtained in Example 1 was replaced by the SiOC structure (2) obtained in this example, the composition for a negative electrode and A negative electrode body and a lithium ion secondary battery were produced and the battery characteristics were evaluated.
  • Example 3 (MeSiO 0.7 )
  • silicon was prepared by the same procedure as in Example 1 except that the dropping amount of methyltrimethoxysilane was changed to 42.5 g.
  • a nanoparticle/methylpolysilsesquioxane composite (3) and its fired product [SiOC structure (3)] powder were produced.
  • a part of the silicon nanoparticles/methylpolysilsesquioxane composite (3) was subjected to a SEM observation test, and a part of the SiOC structure (3) powder was added.
  • Example 2 The test was performed by the above-mentioned method for SEM observation, particle size distribution measurement, and BET specific surface area measurement. Further, in the same manner as in Example 1 except that the SiOC structure (1) obtained in Example 1 was replaced by the SiOC structure (3) obtained in this example, the composition for a negative electrode and A negative electrode body and a lithium ion secondary battery were prepared, and the battery characteristics were evaluated.
  • Example 4 (MePhSiO 0.7 )
  • SiPhSiO 0.7 silicon nanoparticles/methylpolysilsesquioxane composite (1) in Example 1
  • 34.0 g of methyltrimethoxysilane and 12.4 g of phenyltrimethoxysilane were used instead of 24.3 g of methyltrimethoxysilane.
  • Silicon nanoparticles/methylpolysilsesquioxane composite (4) and its fired product [SiOC structure (4)] powder were produced by the same procedure as in Example 1 except that the mixture was used.
  • Example 2 In addition, in the same manner as in Example 1, a part of the silicon nanoparticles/methylpolysilsesquioxane composite (4) was subjected to SEM observation, and a part of the SiOC structure (4) powder was added. The test was performed by the above-mentioned method for SEM observation, particle size distribution measurement, and BET specific surface area measurement. Further, in the same manner as in Example 1 except that the SiOC structure (1) obtained in Example 1 was replaced by the SiOC structure (4) obtained in this example, the composition for a negative electrode and A negative electrode body and a lithium ion secondary battery were produced and the battery characteristics were evaluated.
  • the boat After placing the obtained silicon nanoparticles / methylpolysilsesquioxane complex (5) on an SSA-S grade alumina boat, the boat is placed in a vacuum purge type tube furnace KTF43N1-VPS (manufactured by Koyo Thermo System).
  • the heat treatment condition is as follows: under an argon gas atmosphere (high-purity argon gas 99.999%), while supplying argon gas at a flow rate of 250 ml/min, the temperature is raised at a rate of 4° C./min. By calcining at 5° C. for 5 hours, a calcined product of the silicon nanoparticles/methylpolysilsesquioxane composite (5) was prepared.
  • the calcined product of the silicon nanoparticles / methylpolysilsesquioxane composite (5) obtained as described above was pulverized in a mortar and classified using a stainless sieve having an opening of 32 ⁇ m to obtain the largest particles. 7.2 g of a powder of the SiOC composite material (5) having a diameter of 32 ⁇ m was obtained.
  • Example 1 For a part of the SiOC composite material thus obtained, SEM observation, particle size distribution measurement, and BET specific surface area measurement were performed in the same manner as in Example 1. Furthermore, the composition for a negative electrode, the negative electrode body, and the lithium ion dioxin were prepared in the same manner as in Example 1 except that the SiOC composite material obtained in this Comparative Example was used instead of the SiOC structure obtained in Example 1. The next battery was prepared and the battery characteristics were evaluated.
  • FIG. 1 shows SEM photographs of the respective silicon nanoparticles/methylpolysilsesquioxane composites (1) to (4) produced in Examples 1 to 4.
  • FIGS. 2A and 2B SEM photographs (10, 10) of the SiOC structures (1) to (4) manufactured in Examples 1 to 4 and the SiOC composite material (5) manufactured in Comparative Example 1 are shown. 000 times) are shown respectively.
  • FIG. 2C shows a SEM photograph (20,000 times) of the silicon nanoparticle/methylpolysilsesquioxane composite (6) produced in Comparative Example 2. Further, for each SiOC structure manufactured in Example 1, an SEM photograph (50,000 times) obtained by increasing the magnification is shown in FIG.
  • the compound is coated with polysilsesquioxane produced by the hydrolysis and polycondensation reaction of the compound, and that a plurality of silicon nanoparticles are linked through the polysilsesquioxane coat layer. It was In other words, the SiOC coating layers in the SiOC structures (1) to (4) obtained by the heat treatment are converted into the SiOC coating layers by the heat treatment of the polysilsesquioxane coating layers into ceramics, It is considered that the coating structure of the silicon nanoparticles by the coat layer was maintained without undergoing a large morphological change.
  • the SiOC portion derived from polysilsesquioxane is silicon nanoparticles.
  • the state in which the particles were covered was not observable, and many silicon nanoparticles in which many parts were exposed to the outside were confirmed. That is, in the SiOC composite material manufactured in Comparative Example 1, it was confirmed that the silicon nanoparticles were not uniformly coated with the SiOC portions, but that the both were randomly aggregated with each other.
  • Comparative Example 1 the expression of such an aggregation-like structure was achieved by uniformly adding methyltrimethoxysilane and hydrochloric acid to the silicon nanoparticle dispersion and proceeding with hydrolysis and polycondensation of methyltrimethoxysilane. This is due to the synthesis of a silicon nanoparticles / methylpolysilsesquioxane complex having the form of a bulk gel.
  • the silicon nanoparticles are uniformly coated on the SiOC coating layer derived from polysilsesquioxane, and a plurality of silicon nanoparticles are connected via the SiOC coating layer. It was possible to manufacture a SiOC structure having the structure shown in FIG. Here, the SiOC coat layer had a relatively smooth surface without surface roughness or the like.
  • FIGS. 4A and 4B show graphs of particle size distributions obtained by particle size distribution measurement for each of the SiOC structures manufactured in Examples 1 to 4 and the SiOC composite material manufactured in Comparative Example 1.
  • Table 1 shows the measured volume-based average particle diameter ( ⁇ m), BET specific surface area (m 2 /g) and elemental analysis (mass %) of these SiOC structures and SiOC composite materials.
  • the BET specific surface area shows a value of 23.2 m 2 /g, although the average particle diameter is relatively large. It was confirmed that it was remarkably large compared to the SiOC structure of. The reason for such a result is that, as observed in the SEM photograph (FIG. 2B), since the composite material was crushed to be finely divided, fine powder and surface roughness were generated. Seem. This is because in the particle size distribution graphs shown in FIGS. 4A and 4B, in the particle size distribution of Comparative Example 1, the peak shifts in the direction of larger particle size, while sandwiching the peak on the left side (that is, in the region where the particle size is small). ) Also shows a distribution at a predetermined level, which is considered to be consistent with the result of a broad distribution.
  • the SiOC structures manufactured in Examples 1 to 4 all have a BET specific surface area of less than 10 m 2 /g, which is a relatively low value.
  • the SiOC structures according to Examples 1 to 4 have sharp particle size distribution peaks and are provided as a more uniform particle size morphology.
  • the silicon nanoparticles are uniformly coated with the polysilsesquioxane moiety produced by polycondensation to form a uniform structure without surface roughness. This is consistent with the fact that such a uniform and surface-free structure is maintained even after firing.
  • Example 4 has a relatively large average particle diameter than the SiOC structures manufactured in Examples 1 to 3, and a value larger than that of Comparative Example 1 (17.71 ⁇ m). showed that.
  • Example 4 has a BET specific surface area of 1.3 m 2 /g, which is a remarkably small value (Table 1), and it is understood that the peak of the particle size distribution is also sharp ( FIG. 4B). That is, it is understood that, in Example 4, a structure having a uniform particle size and a uniform surface without roughness is formed as a whole as in Examples 1 to 3, although the particle size is relatively large. This is clear from the SEM photograph shown in FIG. 2A.
  • the capacity retention rate in 5 to 50 cycles was a value of 65% or more in the charge / discharge cycle test. And showed a very good capacity retention rate.
  • the average coulombic efficiencies of these lithium-ion batteries in the 5 to 50 cycles all showed values of around 99%, and maintained extremely good averaged coulombic efficiencies (Table 2 and FIG. 5B).
  • the capacity retention ratio in 5 to 50 cycles was higher than that in Examples 1 to 4 in which the predetermined SiOC structure of the present invention was used as the negative electrode material. It showed only a value of 32.9% and was extremely inferior (Table 2 and FIG. 5A). Furthermore, the lithium-ion battery of Comparative Example 1 also showed a coulombic efficiency of only 97.2% in 5 to 50 cycles, which was inferior to that of the lithium-ion batteries of Examples 1 to 4 (Table 2 and). FIG. 5B).
  • the present invention has high industrial applicability in the field of materials / chemicals for producing SiOC materials, negative electrode active materials, negative electrode materials, etc., and in the field of electrical and electronic equipment such as secondary batteries and various electronic devices.
  • Lithium-ion secondary battery (coin battery 300) 301 Negative electrode material 302 Separator 303 Lithium counter electrode

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Abstract

La présente invention concerne une structure de SiOC qui comprend (A) au moins une particule fine à base de silicium et (B) une couche de revêtement de SiOC contenant au moins Si (silicium), O (oxygène) et C (carbone) en tant qu'éléments constitutifs. La ou les particule(s) fine(s) à base de silicium sont recouvertes par la couche de revêtement de SiOC, la surface spécifique BET étant inférieure ou égale à 20 m2/g, et la taille des particules cumulative à 10 % (D10), la taille des particules cumulative à 50 % (D50) et la taille des particules cumulative à 90 % (D90) obtenues par un procédé de mesure de la distribution des tailles de particules par diffraction/diffusion laser satisfont les conditions 1 nm ≦ D50 ≦ 990 µm et D90/D10 ≦ 13,0.
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CN113248257A (zh) * 2021-05-12 2021-08-13 浙江大学 锂离子电池共连续大孔SiOC负极材料及其制备方法
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CN113034205A (zh) * 2021-04-20 2021-06-25 上海交通大学 一种考虑容载比动态调整的储能站与变电站联合规划方法
CN113034205B (zh) * 2021-04-20 2022-03-11 上海交通大学 一种考虑容载比动态调整的储能站与变电站联合规划方法
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CN113248257B (zh) * 2021-05-12 2022-09-30 浙江大学 锂离子电池共连续大孔SiOC负极材料及其制备方法
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WO2023017694A1 (fr) 2021-08-11 2023-02-16 Dic株式会社 Matériau de batterie secondaire, matériau actif d'électrode négative et batterie secondaire
KR20240042054A (ko) 2021-08-11 2024-04-01 디아이씨 가부시끼가이샤 이차 전지용 재료, 음극 활물질 및 이차 전지

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