WO2021187273A1 - 全固体二次電池用バインダー組成物、全固体二次電池用スラリー、全固体二次電池用固体電解質シート及びその製造方法、並びに全固体二次電池及びその製造方法 - Google Patents
全固体二次電池用バインダー組成物、全固体二次電池用スラリー、全固体二次電池用固体電解質シート及びその製造方法、並びに全固体二次電池及びその製造方法 Download PDFInfo
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- H—ELECTRICITY
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- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/621—Binders
- H01M4/622—Binders being polymers
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- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/621—Binders
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F236/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds
- C08F236/02—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds
- C08F236/04—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds conjugated
- C08F236/06—Butadiene
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- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F236/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds
- C08F236/02—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds
- C08F236/04—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds conjugated
- C08F236/10—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds conjugated with vinyl-aromatic monomers
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- C08F8/00—Chemical modification by after-treatment
- C08F8/42—Introducing metal atoms or metal-containing groups
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- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/0008—Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59
- C08K5/005—Stabilisers against oxidation, heat, light, ozone
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- C—CHEMISTRY; METALLURGY
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- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/04—Oxygen-containing compounds
- C08K5/13—Phenols; Phenolates
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/16—Nitrogen-containing compounds
- C08K5/17—Amines; Quaternary ammonium compounds
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/16—Nitrogen-containing compounds
- C08K5/17—Amines; Quaternary ammonium compounds
- C08K5/18—Amines; Quaternary ammonium compounds with aromatically bound amino groups
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L7/00—Compositions of natural rubber
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
- C08L9/06—Copolymers with styrene
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- 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
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- 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
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0561—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of inorganic materials only
- H01M10/0562—Solid materials
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- H—ELECTRICITY
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- 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
- H01M10/058—Construction or manufacture
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- 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
- H01M10/058—Construction or manufacture
- H01M10/0585—Construction or manufacture of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
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- 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
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
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- 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
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/139—Processes of manufacture
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- H—ELECTRICITY
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- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
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- H—ELECTRICITY
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- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0065—Solid electrolytes
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- 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
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- 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
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Definitions
- the present invention is an all-solid secondary battery binder composition, an all-solid secondary battery slurry containing the composition and a solid electrolyte, and an all-solid secondary formed by applying and drying the slurry on a substrate.
- the present invention relates to a solid electrolyte sheet for a secondary battery and a method for producing the same, and an all-solid secondary battery provided with the sheet and a method for producing the same.
- the all-solid-state secondary battery uses a solid electrolyte that exhibits high ionic conductivity, there is no risk of liquid leakage or ignition, and it is excellent in safety and reliability.
- the all-solid-state secondary battery is also suitable for increasing the energy density by stacking electrodes.
- the battery can have a structure in which the active material layer and the solid electrolyte layer are arranged side by side and serialized. At this time, since the metal package for sealing the battery cell, the copper wire for connecting the battery cell, and the bus bar can be omitted, the energy density of the battery can be significantly increased. Another advantage is good compatibility with a positive electrode material capable of increasing the potential.
- compositions and slurries containing the binder component disclosed in Patent Documents 1 to 4 have a problem that the storage stability is likely to be impaired due to the deterioration of the polymer as the binder component with time. Further, even in the case of an all-solid-state secondary battery, the polymer deteriorates with time due to repeated charging and discharging, and ionic conduction between solid electrolytes is likely to be hindered. In addition, it is required for all-solid-state secondary batteries these days. It was not possible to satisfy the high level of cycle life characteristics under high voltage, and further improvement was required.
- some aspects of the present invention are for all-solid-state secondary batteries, which are excellent in storage stability for a long period of time, excellent in lithium ion conductivity, and can realize good cycle life characteristics even under high voltage. It provides a binder composition.
- the present invention has been made to solve at least a part of the above-mentioned problems, and can be realized as any of the following aspects.
- One aspect of the binder composition for an all-solid-state secondary battery according to the present invention is A polymer (A) having an aromatic vinyl unit based on an aromatic vinyl compound and a conjugated diene unit based on a conjugated diene compound,
- the anti-aging agent (B) is 200 ppm or more and 5,000 ppm or less with respect to the total mass of the binder composition for an all-solid secondary battery.
- the anti-aging agent (B) may contain at least one selected from the group consisting of a phenol-based anti-aging agent and an amine-based anti-aging agent.
- the polymer (A) is a structural unit represented by the following formula (1), a structural unit represented by the following formula (2), a structural unit represented by the following formula (3), and the following formula (4).
- the composition ratios (molar ratios) of the structural units represented by are p, q, r, and s, respectively, even if the value ⁇ represented by the following mathematical formula (i) is less than 0.9. good.
- ⁇ (p + (0.5 ⁇ r)) / (p + q + (0.5 ⁇ r) + s) ⁇ ⁇ ⁇ (i)
- the bonded styrene content of the polymer (A) may be 5 to 40%.
- the polymer (A) may have a unit based on a modifier containing at least one atom selected from the group consisting of nitrogen atom, oxygen atom, silicon atom, germanium atom and tin atom.
- the liquid medium (C) may be at least one selected from the group consisting of aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, ketones, esters and ethers.
- the polymer (A) may be dissolved in the liquid medium (C).
- One aspect of the slurry for an all-solid-state secondary battery according to the present invention is It contains a binder composition for an all-solid-state secondary battery according to any one of the above embodiments, and a solid electrolyte.
- a sulfide-based solid electrolyte or an oxide-based solid electrolyte may be contained.
- One aspect of the all-solid-state secondary battery according to the present invention is At least a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer are provided. At least one of the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer is a layer formed by applying and drying an all-solid-state secondary battery slurry of any of the above embodiments. ..
- One aspect of the solid electrolyte sheet for an all-solid secondary battery according to the present invention is It has a layer formed by applying and drying an all-solid-state secondary battery slurry of any of the above aspects on a base material.
- One aspect of the method for producing a solid electrolyte sheet for an all-solid secondary battery according to the present invention is: The step of applying and drying the slurry for an all-solid-state secondary battery according to any one of the above aspects on a substrate is included.
- One aspect of the method for manufacturing an all-solid-state secondary battery according to the present invention is It is a method of manufacturing an all-solid-state secondary battery through the method of manufacturing a solid electrolyte sheet for an all-solid-state secondary battery of the said aspect.
- the binder composition for an all-solid-state secondary battery according to the present invention the long-term storage stability of the polymer as a binder component is improved. Further, even in the case of an all-solid-state secondary battery, deterioration of the polymer over time due to repeated charging and discharging can be suppressed, so that lithium ion conductivity is excellent and good cycle life characteristics can be realized even under high voltage. An all-solid-state secondary battery can be manufactured.
- Binder composition for all-solid-state secondary battery The binder composition for all-solid-state secondary battery according to the present embodiment has a weight having an aromatic vinyl unit based on an aromatic vinyl compound and a conjugated diene unit based on a conjugated diene compound. It contains the coalescence (A), the anti-aging agent (B) of 200 ppm or more and 5,000 ppm or less with respect to the total mass of the binder composition for an all-solid-state secondary battery, and the liquid medium (C).
- the binder composition for an all-solid-state secondary battery according to the present embodiment may further contain an arbitrary component as long as the effects of the present invention are not impaired.
- each component contained in the binder composition for an all-solid-state secondary battery according to the present embodiment will be described in detail.
- the binder composition for an all-solid-state secondary battery according to the present embodiment contains the polymer (A).
- the polymer (A) has an aromatic vinyl unit based on an aromatic vinyl compound and a conjugated diene unit based on a conjugated diene compound.
- the polymer (A) may contain a structural unit based on another monomer copolymerizable therewith.
- the order of arrangement of the structural units of the polymer (A) is not particularly limited. That is, the polymer (A) may be a block copolymer or a random copolymer.
- the polymer (A) was obtained, for example, by polymerizing an aromatic vinyl compound and a conjugated diene compound to obtain a conjugated diene-based copolymer having an active terminal (polymerization step). It can be produced by a method including a step of modifying the end of the conjugated diene-based copolymer (modification step) and a step of hydrogenating the conjugated diene-based copolymer (hydrohydration step). Specifically, according to the method described in International Publication No. 2014/133097, the molecular weight, the amount of aromatic vinyl compound, the content of vinyl bond, the hydrogenation rate, the type of denaturing agent, etc. are adjusted so as to suit the purpose of use. It can be manufactured by modifying it as appropriate.
- the method for producing the polymer (A) will be described in detail.
- the polymerization step is a step of polymerizing a monomer containing an aromatic vinyl compound and a conjugated diene compound to obtain a conjugated diene-based copolymer having an active terminal.
- the polymerization method for obtaining the conjugated diene-based copolymer any of a solution polymerization method, a gas phase polymerization method, and a bulk polymerization method may be used, but the solution polymerization method is particularly preferable.
- the polymerization type either a batch type or a continuous type may be used.
- a monomer containing an aromatic vinyl compound and a conjugated diene compound is used as a polymerization initiator and, if necessary, a vinyl control agent in an organic solvent (hereinafter referred to as a vinyl control agent).
- a vinyl control agent in an organic solvent
- randomizer a method of polymerizing can be mentioned.
- aromatic vinyl compound examples include styrene, divinylbenzene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, ⁇ -methylstyrene, N, N-dimethylaminoethylstyrene, diphenylethylene and the like.
- the aromatic vinyl compound is particularly preferably one or more compounds selected from styrene and divinylbenzene.
- one type can be used alone or two or more types can be used in combination.
- a conjugated diene compound other than 1,3-butadiene may be used.
- a conjugated diene compound is not particularly limited as long as it can be copolymerized with 1,3-butadiene and an aromatic vinyl compound, and for example, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-. Examples include pentazine. Among these, isoprene is preferable as the conjugated diene compound other than 1,3-butadiene.
- the conjugated diene compound one type may be used alone or two or more types may be used in combination.
- the conjugated diene-based copolymer obtained by the polymerization step may be a copolymer of 1,3-butadiene and an aromatic vinyl compound, or a conjugated diene other than 1,3-butadiene and 1,3-butadiene. It may be a copolymer of a compound and an aromatic vinyl compound. From the viewpoint of high living property in anionic polymerization, the conjugated diene-based copolymer is preferably a copolymer using 1,3-butadiene and styrene.
- the content of the aromatic vinyl compound is preferably 5 to 40% by mass, preferably 8 to 30% by mass, based on the total amount of the monomers used for the polymerization. Is more preferable, and 10 to 27% by mass is particularly preferable. Further, by setting the content of the aromatic vinyl compound within the above range, it is possible to achieve both adhesion and flexibility of the electrode.
- the monomers used in the production of conjugated diene copolymers before hydrogenation are 60 to 95 parts by mass of butadiene, 5 to 40 parts by mass of aromatic vinyl compounds, and 0 to 35 parts by mass of conjugated diene compounds other than butadiene. It is preferable to include a portion. It is preferable to use such a blending amount because it is possible to achieve both adhesion and flexibility of the electrodes.
- monomers other than aromatic vinyl compounds and conjugated diene compounds can be used.
- examples of other monomers include acrylonitrile, methyl (meth) acrylate, ethyl (meth) acrylate and the like.
- the amount of the other monomer used is preferably 20% by mass or less, more preferably 18% by mass or less, and particularly preferably 15% by mass or less, based on the total amount of the monomers used for the polymerization. preferable.
- the polymerization initiator at least one of an alkali metal compound and an alkaline earth metal compound can be used.
- an alkali metal compound and the alkaline earth metal compound those usually used as an initiator of anion polymerization can be used, for example, methyllithium, ethyllithium, n-propyllithium, n-butyllithium, sec-butyllithium, and the like.
- Alkyllithium such as tert-butyllithium; 1,4-dilithiobutane, phenyllithium, stillbenlithium, naphthyllithium, sodium naphthyl, naphthylpotassium, di-n-butylmagnesium, di-n-hexylmagnesium, ethoxypotassium, calcium stearate, etc.
- a lithium compound is preferable.
- At least one of the above-mentioned alkali metal compound and alkaline earth metal compound and a compound that introduces a functional group that interacts with a current collector, a solid electrolyte, or the like at the starting end of the polymer (hereinafter, "compound”).
- (C1) ”) may be mixed and obtained in the presence of a compound (hereinafter, also referred to as“ compound (R) ”).
- compound (R) By carrying out the polymerization in the presence of the compound (R), a functional group having an interaction with a current collector, a solid electrolyte or the like can be introduced into the polymerization initiation terminal of the conjugated diene-based copolymer.
- interaction means an intermolecular force which forms a covalent bond between molecules or is weaker than a covalent bond (for example, ion-dipole interaction, bipolar-dipole interaction, etc. It means forming an electromagnetic force acting between molecules such as a hydrogen bond and a van der Waals force.
- the "functional group that interacts with a current collector, a solid electrolyte, or the like” indicates a group having at least one atom such as a nitrogen atom, an oxygen atom, a silicon atom, a sulfur atom, and a phosphorus atom.
- the compound (C1) is not particularly limited as long as it has a partial structure in which a nitrogen atom, an oxygen atom, a silicon atom, a sulfur atom and a phosphorus atom and a hydrogen atom are directly bonded.
- a nitrogen-containing compound such as a secondary amine, a compound having a hydroxyl group, a silicon-containing compound such as a tertiary silane, a compound having a thiol group, and a compound such as a secondary phosphine can be used.
- a nitrogen-containing compound such as a secondary amine compound is preferable.
- nitrogen-containing compound examples include, for example, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dioctylamine, dihexylamine, dodecamethyleneimine, N, N'-dimethyl-N'-trimethylsilyl-1, 6-diaminohexane, piperidine, 3,3-dimethylpiperidin, 2,6-dimethylpiperidin, 1-methyl-4- (methylamino) piperidine, 2,2,6,6-tetramethylpiperidin, pyrrolidine, piperazin, 2 , 6-Dimethylpiperazin, 1-ethylpiperazine, 2-methylpiperazine, 1-benzylpiperazine, 2,6-dimethylmorpholin, hexamethyleneimine, heptamethyleneimine, dicyclohexylamine, N-methylbenzylamine, di- (2-) Ethylhexyl) amine, diallylamine, morpholin, morph
- the compound (R) is preferably a reaction product of a lithium compound such as alkyllithium and the compound (C1).
- the compound (R) is prepared by mixing the alkali metal compound or the alkaline earth metal compound and the compound (C1) in advance, and the prepared compound ( R) may be added to the polymerization system to carry out the polymerization.
- the compound (R) may be prepared and polymerized by adding an alkali metal compound or an alkaline earth metal compound and the compound (C1) to the polymerization system and mixing the two in the polymerization system. good.
- the randomizer can be used for the purpose of adjusting the vinyl bond content (vinyl bond content) and the like.
- randomizers include dimethoxybenzene, tetrahydrofuran, dimethoxyethane, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, diethylene glycol dimethyl ether, 2,2-di (tetrahydrofuryl) propane, 2- (2-ethoxyethoxy).
- -2-Methylpropane triethylamine, pyridine, N-methylmorpholine, tetramethylethylenediamine and the like. These can be used alone or in combination of two or more.
- the organic solvent used for the polymerization may be any organic solvent that is inert to the reaction, and for example, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons and the like can be used. Of these, hydrocarbons having 3 to 8 carbon atoms are preferable, and specific examples thereof include n-pentane, isopentane, n-hexane, n-hexene, cyclohexane, propene, 1-butene, isobutene, and trans-2.
- -Butene cis-2-butene, 1-pentine, 2-pentine, 1-hexene, 2-hexene, benzene, toluene, xylene, ethylbenzene, cyclopentane, methylcyclopentane, methylcyclohexane, 1-pentene, 2-pentene , Cyclohexene and the like.
- the organic solvent one type can be used alone or two or more types can be used in combination.
- the monomer concentration in the reaction solvent is preferably 5 to 50% by mass, more preferably 10 to 30% by mass, because the balance between productivity and ease of polymerization control can be maintained.
- the temperature of the polymerization reaction is preferably ⁇ 20 to 150 ° C., more preferably 0 to 120 ° C., and particularly preferably 20 to 100 ° C. Further, it is preferable that the polymerization reaction is carried out under a pressure sufficient to keep the monomer in a substantially liquid phase. Such pressure can be obtained by a method such as pressurizing the inside of the reactor with a gas that is inert to the polymerization reaction.
- the 1,2-vinyl bond content in the structural unit derived from butadiene is preferably 5 to 70% by mass, and preferably 10 to 65% by mass. It is more preferably 20 to 60% by mass, and particularly preferably 20 to 60% by mass.
- the 1,2-vinyl bond content is a value measured by 1 1 H-NMR.
- the conjugated diene-based copolymer before hydrogenation preferably has a random copolymerized portion of a structural unit derived from butadiene and a structural unit derived from an aromatic vinyl compound. Having such a specific random copolymerization moiety is preferable in that the dispersibility of the active material and the solid electrolyte can be improved.
- the modification step is a compound in which a functional group that interacts with a current collector, a solid electrolyte, or the like is introduced into the active end of the conjugated diene copolymer obtained by the above polymerization step and the end of the polymerization (hereinafter, "Compound (C2)”. ) ”), which is the process of reacting.
- a functional group that interacts with a current collector, a solid electrolyte, or the like can be introduced into the polymerization-terminated terminal of the conjugated diene-based copolymer.
- the active terminal means a portion (more specifically, a carbon anion) other than the structure derived from the monomer having a carbon-carbon double bond, which is present at the end of the molecular chain.
- the conjugated diene-based copolymer used in the modification reaction may have an unmodified polymerization initiation terminal or is modified as long as it has an active terminal. It may be a polymer.
- the compound (C2) is not particularly limited as long as it is a compound capable of reacting with the active terminal of the conjugated diene copolymer, but is an amino group, a group having a carbon-nitrogen double bond, a nitrogen-containing heterocyclic group, and a phosphino group.
- the compound (C2) at least one selected from the group consisting of the compound represented by the following general formula (5) and the compound represented by the following general formula (6) can be preferably used.
- a 1 has at least one atom selected from the group consisting of nitrogen, phosphorus, oxygen, sulfur and silicon, and has a nitrogen atom, a phosphorus atom, an oxygen atom, with respect to R 5. It is a monovalent functional group bonded with a carbon atom contained in a sulfur atom, a silicon atom or a carbonyl group, or a (thio) epoxy group.
- R 3 and R 4 are hydrocarbyl groups, and R 5 is a hydrocarbi. an alkylene group, r is an integer of 0-2. However, if R 3 and R 4 there are a plurality, the plurality of R 3 and R 4 may be the same or different.
- a 2 has at least one atom selected from the group consisting of nitrogen, phosphorus, oxygen, sulfur and silicon, has no active hydrogen, and has a nitrogen atom with respect to R 9.
- R 6 and R 7 are independently hydrocarbyl groups, and R 8 and R 9 are independent of each other.
- a hydrocarbylene group, m is 0 or 1. However, if R 7 there is a plurality, a plurality of R 7 may be the same or different.
- the hydrocarbyl groups of R 3 , R 4 , R 6 and R 7 are linear or branched alkyl groups having 1 to 20 carbon atoms and 3 to 20 carbon atoms. Is preferably a cycloalkyl group or an aryl group having 6 to 20 carbon atoms.
- r and m are preferably 0 or 1 because the reactivity with the active terminal can be enhanced.
- a 1 is the above monovalent functional group
- at least one atom selected from the group consisting of nitrogen, phosphorus, oxygen, sulfur and silicon possessed by A 1 is not bonded to active hydrogen and is not bonded to active hydrogen. It is preferably protected with a protecting group (eg, a trisubstituted hydrocarbylsilyl group, etc.).
- at least one atom selected from the group consisting of nitrogen, phosphorus, oxygen, sulfur and silicon possessed by A 2 is not bonded to active hydrogen and is a protecting group (for example, a trisubstituted hydrocarbylsilyl group). It is preferably protected by.
- active hydrogen means a hydrogen atom bonded to an atom other than a carbon atom, and preferably has a bond energy lower than that of a carbon-hydrogen bond of polymethylene.
- the protecting group is a functional group that converts A 1 and A 2 into a functional group that is inactive with respect to the polymerization active terminal.
- the (thio) epoxy group means to include an epoxy group and a thioepoxy group.
- a 1 may be a group that can be turned into an onium ion by an onium salt producing agent.
- the compound (C2) has such a group (A 1 )
- excellent adhesion to the conjugated diene-based copolymer can be imparted.
- a 1 for example, a nitrogen-containing group in which two hydrogen atoms of a primary amino group are substituted by two protective groups, and one hydrogen atom of a secondary amino group is substituted by one protective group.
- a phosphorus-containing group consisting of two hydrogen atoms of a nitrogen-containing group, a tertiary amino group, an imino group, a pyridyl group, and a primary phosphino group substituted with two protective groups, and one hydrogen atom of a secondary phosphino group is one.
- Examples include a containing group and a hydrocarbyloxycarbonyl group.
- a containing group and a hydrocarbyloxycarbonyl group since it has good affinity with solid electrolytes and active materials, it is preferably a group having a nitrogen atom, and two hydrogen atoms, a tertiary amino group or a primary amino group, are two protecting groups. More preferably, it is a nitrogen-containing group substituted with.
- Preferred specific examples of the compound (C2) include dibutyldichlorosilicon, methyltrichlorosilicon, dimethyldichlorosilicon, tetrachlorosilicon, triethoxymethylsilane, triphenoxymethylsilane, trimethoxysilane, methyltriethoxysilane, and the above general formula ( Examples thereof include a compound represented by 5) and a compound represented by the above general formula (6).
- Examples of the compound represented by the general formula (5) include N, N-bis (trimethylsilyl) aminopropyltrimethoxysilane, N, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane, and N-trimethylsilyl-N.
- examples of the compound represented by the above general formula (6) include 2,2-dimethoxy-1- (3-trimethoxysilylpropyl) -1,2-azacilolidine and 2,2-dimethoxy-1- (3).
- the compound (C2) may be used alone or in combination of two or more.
- a Germanium compound, a stannane compound and the like can be preferably used in addition to the compound (C2).
- germanium atoms and tin atoms can be introduced into the polymer (A).
- a compound group of a compound (R), a compound (C2), a Germanium compound and a stannane compound is also referred to as a "denaturing agent”.
- German compound examples include an alkoxy German compound such as a monoalkoxy German compound, a dialkoxy German compound, a trialkoxy German compound, and a tetraalkoxy German compound; a halogenated triorganic German compound, a dihalogenated diorganic German compound, and a trihalogenated compound. Examples thereof include organic German compounds and tetrahalogenated German compounds. Further, the Germanium compound is the same as the compound exemplified as the silane compound, and examples thereof include a compound having a germanium atom instead of a silicon atom.
- the stunnan compound examples include alkoxy stannan compounds such as monoalkoxy stannan compounds, dialkoxy stannan compounds, trialkoxy stannan compounds, and tetraalkoxy stannan compounds; halogenated triorganic stannan compounds and dihalogenated diorganic stannans. Examples thereof include compounds, trihalogenated organic stannan compounds, and tetrahalogenated stannan compounds.
- the stannane compound is the same as the compound exemplified as the silane compound, and examples thereof include a compound having a tin atom instead of a silicon atom.
- stannan compounds include tetrachlorotin, tetrabromotin, trichlorobutyltin, trichloromethyltin, trichlorooctyltin, dibromodimethyltin, dichlorodimethyltin, dichlorodibutyltin, dichlorodioctyltin, 1,2-bis (trichloro).
- Stanyl) ethane 1,2-bis (methyldichlorostanylethane), 1,4-bis (trichlorostanyl) butane, 1,4-bis (methyldichlorostanyl) butane, ethyltin tristearate, butyltin
- Preferable examples include trisoctanoate, butyltin tristearate, butyltin trislaurate, dibutyltin bisoctanoate, dibutyltin bisstearate, dibutyltin bislaurate and the like. Of these, it is particularly preferable to use tetrachlorotin (SnCl 4).
- the above terminal denaturation reaction can be carried out as, for example, a solution reaction.
- This solution reaction may be carried out using a solution containing an unreacted monomer after the completion of the polymerization reaction in the above polymerization step, and the conjugated diene copolymer contained in the solution is isolated and an appropriate solvent such as cyclohexane is used. It may be carried out after being dissolved in. Further, the terminal denaturation reaction may be carried out by either a batch type or a continuous type.
- the method of adding the compound (C2), the Germanium compound or the stannane compound is not particularly limited, and examples thereof include a method of adding the compound (C2) collectively, a method of adding the compound in a divided manner, and a method of continuously adding the compound (C2).
- the amount of the compound (C2), German compound or stannane compound used in the terminal modification reaction may be appropriately set according to the type of the compound used in the reaction, but it may be a metal atom involved in the polymerization reaction of the polymerization initiator. On the other hand, it is preferably 0.1 molar equivalent or more, more preferably 0.3 molar equivalent or more. By setting the amount to be used to 0.1 molar equivalent or more, the denaturation reaction can be sufficiently proceeded, and the dispersion stability of the slurry can be suitably improved.
- the temperature of the terminal denaturation reaction is usually the same as the temperature of the above-mentioned polymerization reaction, preferably ⁇ 20 to 150 ° C., more preferably 0 to 120 ° C., and particularly preferably 20 to 100 ° C. preferable.
- the reaction time of the denaturation reaction is preferably 1 minute to 5 hours, more preferably 2 minutes to 1 hour.
- the polymer (A) preferably has a unit based on a modifier containing at least one atom selected from the group consisting of nitrogen atom, oxygen atom, silicon atom, germanium atom and tin atom.
- the polymer (A) may be hydrogenated from the modified or unmodified conjugated diene-based copolymer obtained above.
- any method and conditions can be used as long as a conjugated diene-based copolymer having a desired hydrogenation rate can be obtained.
- a method using a catalyst containing an organic metal compound of titanium as a main component as a hydrogenation catalyst; a catalyst composed of an organic compound of iron, nickel, cobalt and an organic metal compound such as alkylaluminum is used.
- Method to be used Method using an organic complex of an organic metal compound such as ruthenium and rhodium; Method using a catalyst in which a metal such as palladium, platinum, ruthenium, cobalt and nickel is supported on a carrier such as carbon, silica and alumina. and so on.
- a homogeneous catalyst composed of a titanium organometallic compound alone or a titanium organometallic compound and an organometallic compound of lithium, magnesium, and aluminum (Japanese Patent Publication No. 63-4841, Japanese Patent Publication No. 1-377970).
- the method of hydrogenating under mild conditions of low pressure and low temperature using Japanese Patent Application Laid-Open No. 2000-37632) is industrially preferable, and the hydrogenation selectivity to the double bond of butadiene is high, and the object of the present invention is Are suitable.
- the hydrogenation reaction of the modified conjugated diene-based copolymer is carried out in a solvent that is inert to the catalyst and in which the conjugated diene-based copolymer is soluble.
- Preferred solvents include aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane and n-octane, alicyclic hydrocarbons such as cyclohexane and cycloheptane, and aromatic hydrocarbons such as benzene and toluene. It is a single ether such as diethyl ether and tetrahydrofuran, or a mixture containing them as a main component.
- the conjugated diene-based copolymer is maintained at a predetermined temperature under hydrogen or an inert atmosphere, a hydrogenation catalyst is added under stirring or non-stirring, and then hydrogen gas is introduced. It is performed by pressurizing to a predetermined pressure.
- the inert atmosphere means an atmosphere that does not react with the substances involved in the hydrogenation reaction, and examples thereof include helium, neon, and argon. Air and oxygen are not preferable because they oxidize the catalyst and cause the catalyst to be deactivated. In addition, nitrogen acts as a catalytic poison during the hydrogenation reaction and reduces the hydrogenation activity, which is not preferable. In particular, it is most preferable that the inside of the hydrogenation reactor has an atmosphere of hydrogen gas alone.
- the hydrogenation reaction process for obtaining a hydrogenated conjugated diene-based copolymer can be used in any of a batch process, a continuous process, and a combination thereof.
- a titanocene diaryl compound used as the hydrogenation catalyst, it may be added alone to the reaction solution or as a solution of an inert organic solvent.
- an inert organic solvent used when the catalyst is used as a solution, various solvents that do not react with the substances involved in the hydrogenation reaction can be used. It is preferably the same solvent as the solvent used for the hydrogenation reaction.
- the amount of the catalyst added is 0.02 to 20 mmol per 100 g of the conjugated diene-based copolymer before hydrogenation.
- the polymer (A) is a structural unit represented by the following formula (1), a structural unit represented by the following formula (2), a structural unit represented by the following formula (3), and the following formula (4).
- the constituent ratios (molar ratios) of the structural units represented by) in the polymer are p, q, r, and s, respectively, the value ⁇ represented by the following mathematical formula (i) is less than 0.9. Is preferable.
- ⁇ (p + (0.5 ⁇ r)) / (p + q + (0.5 ⁇ r) + s) ⁇ ⁇ ⁇ (i)
- ⁇ is preferably less than 0.9, more preferably less than 0.8, and particularly preferably less than 0.7.
- ⁇ of the said formula (i) corresponds to the hydrogenation ratio of the conjugated diene-based copolymer. For example, when ⁇ is 0.6, the hydrogenation rate of the conjugated diene-based copolymer is 60%. Further, ⁇ may be 0.
- the hydrogenation rate in the conjugated diene-based copolymer can be adjusted by adjusting the time of the hydrogenation reaction, the amount of hydrogen supplied, or the like. This hydrogenation rate can be measured by 1 1 H-NMR.
- the anti-aging agent (B) may be added after the above-mentioned modification step or hydrogenation step.
- the polymer (A) is subjected to a solvent removal step by steam stripping, a drying step by a heat roll, and a subsequent long-term storage in a veil shape, which is performed after the synthesis of the polymer (A).
- a solvent removal step by steam stripping a drying step by a heat roll
- a subsequent long-term storage in a veil shape which is performed after the synthesis of the polymer (A).
- anti-aging agent examples include the anti-aging agents described in the section “1.2. Anti-aging agent (B)” described later.
- the anti-aging agent (B) can be added in a solid state, a molten state, or a solution state in which the anti-aging agent (B) is dissolved in a solvent.
- the state of the polymer (A) when the anti-aging agent (B) is added may be either a solid state or a solution state, but it is preferably in a solution state from the viewpoint of dispersibility of the anti-aging agent (B).
- the lower limit of the content ratio of the anti-aging agent is preferably 0.05 parts by mass with respect to 100 parts by mass of the polymer (A), preferably 0.1. It is more preferably parts by mass, and particularly preferably 0.2 parts by mass.
- the upper limit of the content ratio of the antiaging agent is preferably 2 parts by mass, more preferably 1.5 parts by mass, and particularly preferably 1.2 parts by mass.
- a suitable method for obtaining the polymer (A) is a method in which a monomer containing butadiene is solution-polymerized in the presence of an alkali metal compound, and the obtained polymer solution is used as it is for a modification step, which is industrial. It is useful for. Further, it may be subjected to a hydrogenation step if necessary. In these cases, the polymer (A) can be obtained by removing the solvent from the solution obtained above and isolating the polymer (A). The polymer (A) can be isolated by a known desolvation method such as steam stripping and a drying operation such as heat treatment.
- the polymer (A) is composed of a group consisting of an amino group, a nitrogen-containing heterocyclic group, a phosphino group, a hydroxyl group, a thiol group and a hydrocarbyloxysilyl group in that the dispersion stability of the slurry and the adhesion of the electrodes can be improved. It is preferable to have one or more functional groups selected, and it is more preferable to have one or more functional groups selected from the group consisting of an amino group, a nitrogen-containing heterocyclic group and a hydrocarbyloxysilyl group. It is particularly preferable that these functional groups are introduced at the ends of the polymer (A).
- the bonded styrene content of the polymer (A) is preferably 5 to 40%, more preferably 8 to 30%, and particularly preferably 10 to 27%.
- the bound styrene content can be measured by 1 1 H-NMR measurement.
- the weight average molecular weight of the polymer (A) (Mw) is preferably 1.0 ⁇ 10 5 ⁇ 2.0 ⁇ 10 6, more preferably be 1.0 ⁇ 10 5 ⁇ 1.5 ⁇ 10 6 , particularly preferably 1.5 ⁇ 10 5 ⁇ 1.0 ⁇ 10 6.
- weight average molecular weight (Mw) is at least the above lower limit value, the adhesion of the electrodes tends to be improved.
- weight average molecular weight (Mw) is not more than the above upper limit value, the flexibility of the electrode tends to be maintained.
- “weight average molecular weight (Mw)” means polystyrene-equivalent weight average molecular weight measured by gel permeation chromatography (GPC).
- the polymer (A) is preferably in a state of being dissolved in a liquid medium (C) described later.
- the polymer (A) dissolves in the liquid medium (C) means that the solubility of the polymer (A) in the liquid medium (C) is 1 g or more with respect to 100 g of the liquid medium (C). .. Since the polymer (A) is in a state of being dissolved in the liquid medium (C), the surface of the active material can be easily coated by the polymer (A) having excellent flexibility and adhesion. It is easy to obtain an all-solid-state secondary battery that can effectively suppress dropping due to expansion and contraction and exhibits good charge / discharge durability characteristics. Further, the stability of the slurry is improved, and the applicability of the slurry to the current collector is also improved, which is preferable.
- the binder composition for an all-solid-state secondary battery according to the present embodiment contains an antiaging agent (B) of 200 ppm or more and 5,000 ppm or less with respect to the total mass of the binder composition.
- an antiaging agent (B) of 200 ppm or more and 5,000 ppm or less with respect to the total mass of the binder composition.
- the polymer (A) when used as a binder for an all-solid secondary battery, it is usually liquefied, but the anti-aging agent contained in the polymer (A) is consumed by heating in the solution step. Since the concentration is diluted by solution formation, it is necessary to control the concentration of the anti-aging agent again. If the concentration is not controlled, microgels may be generated during storage of the solution of the polymer (A), and protrusions and craters may be generated on the coating film of the slurry using the polymer (A).
- the antiaging agent having a concentration equal to or higher than the lower limit is not added, the stability of the slurry is also poor, and the polymer (A) is deteriorated when the electrode plate is dried or when the battery is charged and discharged, and the battery characteristics are deteriorated.
- the binder of the negative electrode and the solid electrolyte layer needs to follow the volume change (expansion / contraction) of the negative electrode active material due to charge / discharge, and if the followability is poor, the conduction path of lithium ions cannot be maintained, and lithium. Ion conductivity decreases and resistance increases.
- anti-aging agent (B) examples include phenol-based anti-aging agents, amine-based anti-aging agents, quinone-based anti-aging agents, organic phosphorus-based anti-aging agents, sulfur-based anti-aging agents, phenothiazine-based anti-aging agents, and the like. Be done. Among these, at least one selected from the group consisting of phenol-based anti-aging agents and amine-based anti-aging agents is preferable.
- phenolic anti-aging agent examples include p-methoxyphenol, 2,6-di-tert-butyl-p-cresol, phenol, hydroquinone, p-cresol, butylhydroxyanisole, propyl castorate, chlorogenic acid and catechin.
- Caffeic acid genquanin, luteolin, tocopherol, catechol, resorcinol, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, pyrogallol, 4,4'-butylidenebis (6-tert-butyl-m-cresol), 2,2 '-Methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis (6-tert-butyl-4-ethylphenol), 4,4'-thiobis (6-tert-butyl-m-cresol) ), 2,5-Di-tert-amylhydroquinone, styrene phenol, 2,5-di-tert-butylhydroquinone, 2-methyl-4,6-bis [(n-octylthio) methyl] phenol, 2,4 -Bis (dodecylthiomethyl) -6-methylphenol, 2-tert-butyl-6- (3-
- amine-based antioxidants examples include 1-naphthylamine, 2-naphthylamine, phenylenediamine, 4,4'-diaminobenzophenone, 4,4'-bis (dimethylamino) benzophenone, and N-isopropyl-N'-phenylbenzene.
- Aromatic amines such as -2,2,4-trimethyl-1,2-dihydroquinoline can be mentioned.
- amine-based antiaging agents such as a light stabilizer (HALS), a hindered amine compound, and a nitroxyl radical (2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO)) can also be preferably used. ..
- HALS light stabilizer
- TEMPO nitroxyl radical
- Examples of phosphorus-based antiaging agents include phosphite compounds.
- Examples of the sulfur-based antiaging agent include thiol compounds and sulfide compounds such as pentaerythrityl tetrakis (3-laurylthiopropionate).
- the lower limit of the concentration of the antiaging agent (B) is 200 ppm, preferably 300 ppm, and more preferably 400 ppm with respect to the total mass of the binder composition for the all-solid-state secondary battery.
- the upper limit of the concentration of the antiaging agent (B) is 5,000 ppm, preferably 4,500 ppm, and more preferably 4,200 ppm with respect to the total mass of the binder composition for the all-solid-state secondary battery. ..
- the interaction between the polymer (A) and the anti-aging agent (B) can prevent the anti-aging agent (B) from bleeding out after the slurry is applied. As a result, it is possible to prevent the antiaging agent (B) from reacting with the solid electrolyte and deteriorating the battery performance.
- the lower limit of the content ratio of the anti-aging agent (B) is preferably 2,000 ppm, more preferably 3,000 ppm, and particularly preferably 4,000 ppm with respect to 100 parts by mass of the polymer (A). be.
- the upper limit of the content ratio of the anti-aging agent (B) is preferably 50,000 ppm, more preferably 45,000 ppm, and particularly preferably 42,000 ppm with respect to 100 parts by mass of the polymer (A). be.
- the interaction between the polymer (A) and the anti-aging agent (B) can prevent the anti-aging agent (B) from bleeding out after the slurry is applied. As a result, it is possible to prevent the antiaging agent (B) from reacting with the solid electrolyte and deteriorating the battery performance.
- the liquid medium (C) is not particularly limited, but is an aliphatic hydrocarbon such as hexane, heptane, octane, decane, and dodecane; an alicyclic hydrocarbon such as cyclohexane, cycloheptane, cyclooctane, and cyclodecane; toluene, xylene, etc.
- Aromatic hydrocarbons such as mesitylene, naphthalene and tetralin; ketones such as 3-pentanone, 4-heptanone, methylhexyl ketone and diisobutyl ketone; butyl acetate, butyl butyrate, methyl butanoate, butyl pentanate, butyl hexanoate, butyric acid Esters such as pentyl, pentyl pentanate, pentyl hexanoate, hexyl butyrate, hexyl pentanate, hexyl hexanoate; ethers such as dibutyl ether, tetrahydrofuran, anisole and the like can be used. These solvents can be used alone or in combination of two or more.
- the content of the liquid medium (C) is preferably 100 to 10,000 parts by mass, more preferably 150 to 5,000 parts by mass, and 200 to 4,000 parts by mass with respect to 100 parts by mass of the polymer (A). More preferably, 300 to 3,000 parts by mass is particularly preferable.
- the binder composition for an all-solid-state secondary battery according to the present embodiment may contain additives such as a thickener, if necessary.
- the thickener examples include cellulosic polymers such as carboxymethyl cellulose, methyl cellulose, ethyl cellulose, and hydroxypropyl cellulose; poly (meth) acrylic acid; the cellulose compound or the ammonium salt or alkali metal salt of the poly (meth) acrylic acid; Modified polyvinyl alcohol, polyethylene oxide; polyvinylpyrrolidone, polycarboxylic acid, oxidized starch, phosphate starch, casein, various modified starches, chitin, chitosan derivatives and the like. Among these, cellulosic polymers are preferable.
- the content ratio of the thickener is based on 100 parts by mass of the total solid content of the binder composition for an all-solid secondary battery. It is preferably 5 parts by mass or less, and more preferably 0.1 to 3 parts by mass.
- an antiaging agent (B) and a liquid medium (C) are added to the polymer (A). If necessary, other additives are further added, and the mixture is appropriately stirred to dissolve the polymer (A) and the antiaging agent (B) in the liquid medium (C).
- the binder composition for an all-solid-state secondary battery according to the present embodiment can form a binder having high adhesion not only to the current collector of the electrode but also to the solid electrolyte material, and the amount used. Can be reduced and the conductivity of the solid electrolyte layer can be improved, so that it can be suitably used for an all-solid-state battery.
- a step of removing a particulate metal component in the binder composition (hereinafter, also referred to as a “particulate metal removing step”) is performed. It may be included.
- the “particulate metal component” refers to those existing in the form of particles in the binder composition, and does not include those present in the molten metal ion state. ..
- the method of removing the particulate metal component from the binder composition for an all-solid secondary battery in the particulate metal removing step is not particularly limited, and for example, a method of removing by filtration using a filter, a method of removing by a vibrating sieve. , A method of removing by centrifugation, a method of removing by magnetic force, and the like. Above all, since the object to be removed is a metal component, a method of removing by magnetic force is preferable.
- the method of removing the metal component by magnetic force is not particularly limited as long as it can remove the metal component, but in consideration of productivity and removal efficiency, a magnetic filter is installed in the production line of the binder composition for an all-solid-state secondary battery.
- a method of arranging and removing by passing the polymer solution is preferable.
- the step of removing the particulate metal component from the polymer solution with a magnetic filter is preferably performed by passing a magnetic filter that forms a magnetic field having a magnetic flux density of 100 gauss or more. If the magnetic flux density is low, the removal efficiency of the metal component is lowered, so that it is preferably 1000 gauss or more, more preferably 2000 gauss or more, and most preferably 5000 gauss or more in consideration of removing stainless steel having weak magnetism.
- the magnetic filter When arranging the magnetic filter in the production line, it is preferable to include a step of removing coarse foreign substances or metal particles by a filter such as a cartridge filter on the upstream side of the magnetic filter. This is because the coarse metal particles may pass through the magnetic filter depending on the flow rate of filtration.
- the magnetic filter is effective even if it is filtered only once, it is more preferable that it is a circulation type. This is because the efficiency of removing metal particles is improved by adopting the circulation type.
- the place where the magnetic filter is placed is not particularly limited, but the binder composition for an all-solid-state secondary battery is preferably filled in the container.
- the binder composition for an all-solid-state secondary battery is preferably filled in the container.
- it is preferably placed in front of the filtration filter. This is to prevent mixing into the product when the metal component is desorbed from the magnetic filter.
- the particulate metal component include metals such as Fe, Ni, and Cr, or metal compounds thereof.
- the above-mentioned particulate metal component may remain in the binder composition for an all-solid secondary battery according to the present embodiment, but the content of the particulate metal component having a particle size of 20 ⁇ m or more is increased by the particle metal removing step. It is preferable to remove the particulate metal component so as to be 10 ppm or less.
- the content of the particulate metal component having a particle size of 20 ⁇ m or more is such that the obtained binder composition for an all-solid secondary battery is further filtered with a mesh having a mesh size of 20 ⁇ m, and the elements of the metal particles meshed on are separated. Elemental analysis can be performed using an X-ray microanalyzer (EPMA), and the metal dissolved in a soluble acid can be measured using ICP (Inductively Coupled Plasma).
- EPMA X-ray microanalyzer
- ICP Inductively Coupled Plasma
- All-solid-state secondary battery slurry contains the above-mentioned all-solid-state secondary battery binder composition and a solid electrolyte.
- the slurry for an all-solid secondary battery according to the present embodiment can be used as a material for forming any active material layer of the positive electrode active material layer and the negative electrode active material layer, and also forms a solid electrolyte layer. It can also be used as a material for.
- the slurry for an all-solid-state secondary battery for forming the positive electrode active material layer includes the above-mentioned binder composition for an all-solid-state secondary battery, a solid electrolyte, and an active material for a positive electrode (hereinafter, also simply referred to as “positive electrode active material”). ) And. Further, the slurry for the all-solid secondary battery for forming the negative electrode active material layer includes the above-mentioned binder composition for the all-solid-state secondary battery, the solid electrolyte, and the active material for the negative electrode (hereinafter, simply "negative negative active material”). ”).
- the all-solid-state secondary battery slurry for forming the solid-state electrolyte layer contains the above-mentioned all-solid-state secondary battery binder composition and the solid electrolyte.
- the components that can be contained in the slurry for an all-solid-state secondary battery according to the present embodiment will be described.
- Active material ⁇ Positive electrode active material>
- the positive electrode active material include MnO 2 , MoO 3 , V 2 O 5 , V 6 O 13 , Fe 2 O 3 , Fe 3 O 4 , Li (1-x) CoO 2 , Li (1-x) NiO.
- the average particle size of the positive electrode active material is not particularly limited, but is preferably 0.1 ⁇ m to 50 ⁇ m because the contact area of the solid interface can be increased.
- a crusher such as a mortar, a ball mill, a sand mill, a vibrating ball mill, a satellite ball mill, or a swirling air jet mill, or a classifier such as a sieve or a wind classifier can be used. good.
- wet pulverization in which a solvent such as water or methanol coexists may be performed, if necessary. Both the dry type and the wet type can be used for the classification.
- the positive electrode active material obtained by the firing method may be used after being washed with water, an acidic aqueous solution, an alkaline aqueous solution, or an organic solvent.
- the average particle size of the active material is the volume average particle size measured using a particle size distribution measuring device based on the laser diffraction method.
- a particle size distribution measuring device examples include the HORIBA LA-300 series and the HORIBA LA-920 series (all manufactured by HORIBA, Ltd.).
- the content ratio of the positive electrode active material is preferably 20 to 90 parts by mass when the total of the solid components is 100 parts by mass. More preferably, it is 40 to 80 parts by mass.
- the negative electrode active material is not particularly limited as long as it can reversibly occlude and release lithium ions and the like, but for example, carbonaceous materials, metal oxides such as tin oxide and silicon oxide, lithium alone, lithium aluminum alloys and the like. Examples thereof include a lithium alloy, a metal capable of forming an alloy with lithium such as Sn, Si or In, and the like. Of these, a carbonaceous material is preferably used from the viewpoint of reliability, and a silicon-containing material is preferably used from the viewpoint of increasing the battery capacity.
- the carbonaceous material is not particularly limited as long as it is a material substantially composed of carbon, but for example, artificial graphite such as petroleum pitch, natural graphite and vapor-grown graphite, PAN-based resin, furfuryl alcohol resin and the like. Examples thereof include a carbonaceous material obtained by firing various synthetic resins. Furthermore, various carbon fibers such as PAN-based carbon fibers, cellulose-based carbon fibers, pitch-based carbon fibers, vapor-grown carbon fibers, dehydrated PVA-based carbon fibers, lignin carbon fibers, glassy carbon fibers, and activated carbon fibers, mesophase. Examples thereof include microspheres, graphite whisker, and flat plate-shaped graphite.
- Silicon-containing materials can occlude more lithium ions than commonly used graphite and acetylene black. That is, since the lithium ion occlusion amount per unit weight increases, the battery capacity can be increased. As a result, there is an advantage that the battery drive time can be lengthened, and it is expected to be used for an in-vehicle battery or the like in the future.
- silicon-containing materials have a large volume change due to occlusion and release of lithium ions
- graphite and acetylene black have a volume expansion of about 1.2 to 1.5 times due to occlusion of lithium ions.
- the negative electrode active material containing silicon may be about three times as much.
- the durability of the negative electrode active material layer may be insufficient, for example, contact shortage may easily occur, or the cycle life (battery life) may be shortened.
- the negative electrode active material layer formed by using the slurry for an all-solid-state secondary battery according to the present embodiment exhibits high durability (strength) because the binder component follows even if such expansion and contraction are repeated. Therefore, it has an excellent effect that good cycle life characteristics can be realized even under a high voltage.
- the average particle size of the negative electrode active material is not particularly limited, but is preferably 0.1 ⁇ m to 60 ⁇ m because the contact area of the solid interface can be increased.
- the above-exemplified crusher or classifier can be used.
- the content ratio of the negative electrode active material is preferably 20 to 90 parts by mass when the total of the solid components is 100 parts by mass. More preferably, it is 40 to 80 parts by mass.
- the slurry for an all-solid secondary battery according to the present embodiment contains a solid electrolyte.
- a solid electrolyte generally used for an all-solid secondary battery can be appropriately selected and used, but a sulfide-based solid electrolyte or an oxide-based solid electrolyte is preferable.
- the lower limit of the average particle size of the solid electrolyte is preferably 0.01 ⁇ m, more preferably 0.1 ⁇ m.
- the upper limit of the average particle size of the solid electrolyte is preferably 100 ⁇ m, more preferably 50 ⁇ m.
- the lower limit of the content ratio of the solid electrolyte is such that the battery performance and the effect of reducing / maintaining the interface resistance can be compatible with each other. Therefore, when the total of the solid components is 100 parts by mass. , 50 parts by mass, more preferably 70 parts by mass, and particularly preferably 90 parts by mass. Due to the same effect, the upper limit of the content ratio of the solid electrolyte is preferably 99.9 parts by mass, more preferably 99.5 parts by mass, when the total of the solid components is 100 parts by mass. It is particularly preferably 99.0 parts by mass. However, when used together with the positive electrode active material or the negative electrode active material, it is preferable that the total sum thereof is in the above concentration range.
- the sulfide-based solid electrolyte preferably contains a sulfur atom (S) and a metal element of Group 1 or Group 2 of the periodic table, has ionic conductivity, and has electron insulation.
- the composition ratio of each element can be controlled by adjusting the blending amount of the raw material compound when producing the sulfide-based solid electrolyte.
- the sulfide-based solid electrolyte may be amorphous (glass), crystalline (glass ceramics), or only partially crystallized.
- the ratio of Li 2 S and P 2 S 5 is, Li 2 S: at a molar ratio of P 2 S 5, preferably 65: 35 ⁇ It is 85:15, more preferably 68:32 to 80:20.
- the lithium ion conductivity of the sulfide-based solid electrolyte is preferably 1 ⁇ 10 -4 S / cm or more, and more preferably 1 ⁇ 10 -3 S / cm or more.
- a Li 2 S made by using the raw material composition containing a sulfide of group 13 to group 15 element, and the like.
- Specific examples include Li 2 SP 2 S 5 , Li 2 S-GeS 2 , Li 2 S-GeS 2- ZnS, Li 2 S-Ga 2 S 3 , Li 2 S-GeS 2 -Ga 2 S 3 , Li 2 S-GeS 2- P 2 S 5 , Li 2 S-GeS 2- Sb 2 S 5 , Li 2 S-GeS 2- Al 2 S 3 , Li 2 S-SiS 2 , Li 2 S-Al 2 S 3 , Li 2 S-SiS 2- Al 2 S 3 , Li 2 S-SiS 2- P 2 S 5 , Li 2 S-SiS 2 -Li I, Li 2 S-SiS 2 -Li 4 SiO 4 , Li 2 Examples thereof include S-SiS 2 -Li 3 PO 4 , Li 10 GeP 2 S 12
- Li 2 SP 2 S 5 , Li 2 S-GeS 2- Ga 2 S 3 , Li 2 S-GeS 2- P 2 S 5 , Li 2 S-SiS 2- P 2 S 5 , Li 2 S-SiS 2 -Li 4 SiO 4 , Li 2 S-SiS 2 -Li 3 PO of four crystalline and / or amorphous raw material composition is preferred because it has high lithium ion conductivity.
- Examples of the method for synthesizing a sulfide-based solid electrolyte using such a raw material composition include an amorphization method.
- Examples of the amorphization method include a mechanical milling method and a melt quenching method. Above all, the mechanical milling method is preferable because it enables processing at room temperature and simplifies the manufacturing process.
- the sulfide-based solid electrolyte is, for example, T.I. Ohtomo, A.M. Hayashi, M. et al. Tassumisago, Y. et al. Tsuchida, S.A. Hama, K.K. Kawamoto, Journal of Power Sources, 233, (2013), pp231-235 or A.I. Hayashi, S.A. Hama, H. Morimoto, M.D. Tatsumi sago, T. et al. Minami, Chem. Lett. , (2001), pp872-873, etc., and can be synthesized with reference to the literature.
- the oxide-based solid electrolyte contains an oxygen atom (O) and a metal element of Group 1 or Group 2 of the periodic table, and preferably has ionic conductivity and electron insulation.
- Lithium super ionic conductor Lithium super ionic conductor type Li 3.5 Zn 0.25 GeO 4 having a crystal structure
- NASICON Near super ionic conductor
- crystal structure having LiTi 2 P 3 O 12, Li ( 1 + xb + yb) (Al, Ga) xb (Ti, Ge) (2-xb) Siyb P (3-yb) O 12 (however, 0 ⁇ xb ⁇ 1, 0 ⁇ yb ⁇ 1), and has a garnet-type crystal structure. Examples thereof include Li 7 La 3 Zr 2 O 12.
- a phosphorus compound containing Li, P and O is also preferable.
- lithium phosphate Li 3 PO 4
- LiPON in which a part of the oxygen atom of lithium phosphate is replaced with a nitrogen atom
- LiPOD LiPOD
- D is Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Ag, Ta, W, Pt and at least one selected from Au
- LiAON (A represents at least one selected from Si, B, Ge, Al, C and Ga) and the like can also be preferably used.
- Li (1 + xb + yb) Al, Ga) xb (Ti, Ge) (2-xb) Si yb P (3-yb) O 12 (where 0 ⁇ xb ⁇ 1 and 0 ⁇ yb ⁇ 1).
- the lithium ion conductivity of the oxide-based solid electrolyte is preferably 1 ⁇ 10 -6 S / cm or more, more preferably 1 ⁇ 10 -5 S / cm or more, and particularly preferably 5 ⁇ 10 -5 S / cm or more.
- the slurry for an all-solid-state secondary battery according to the present embodiment may contain other additives, if necessary, in addition to the above-mentioned components.
- other additives include a conductivity-imparting agent, a thickener, a liquid medium (however, the amount brought in from the binder composition for an all-solid secondary battery is excluded) and the like.
- the conductivity-imparting agent Since the conductivity-imparting agent has an effect of assisting the conductivity of electrons, it is added to an all-solid-state secondary battery slurry for forming a positive electrode active material layer or a negative electrode active material layer.
- Specific examples of the conductivity-imparting agent include activated carbon, acetylene black, ketjen black, furnace black, graphite, carbon fiber, and carbon such as fullerene. Among these, acetylene black and furnace black are preferable.
- the content ratio of the conductivity-imparting agent is preferably 20 parts by mass or less with respect to 100 parts by mass of the active material. It is more preferably 15 parts by mass, and particularly preferably 2 to 10 parts by mass.
- the thickener include the thickener exemplified in the section ⁇ Thickener> in "1.4. Other Additives" described above.
- the content ratio of the thickener is 5 parts by mass with respect to 100 parts by mass of the total solid content of the slurry for an all-solid secondary battery.
- the amount is preferably 0.1 to 3 parts by mass, and more preferably 0.1 to 3 parts by mass.
- liquid medium examples include the same liquid medium as the liquid medium (C) exemplified in the above-mentioned section “1.3. Liquid medium (C)”.
- the same liquid medium as the liquid medium (C) contained in the binder composition for the all-solid secondary battery may be added, which is different.
- a liquid medium may be added, but it is preferable to add the same liquid medium.
- the content ratio of the liquid medium in the slurry for the all-solid-state secondary battery according to the present embodiment makes the coating property good and suppresses the concentration gradient of the polymer (A) and the active material in the drying treatment after coating. Therefore, it can be adjusted to any ratio.
- a solid electrolyte and optionally used in the binder composition for all-solid-state secondary batteries described above are optionally used. It is preferable to produce by adding additional components and mixing them. In order to mix the binder composition for an all-solid-state secondary battery with other components, it can be carried out by stirring by a known method.
- a mixer capable of stirring to the extent that agglomerates of solid electrolyte particles do not remain in the slurry and necessary and sufficient dispersion conditions are selected.
- the degree of dispersion can be measured by a grain gauge, but it is preferable to mix and disperse so as to eliminate agglomerates larger than at least 100 ⁇ m.
- mixers suitable for such conditions include ball mills, bead mills, sand mills, defoamers, pigment dispersers, grinders, ultrasonic dispersers, homogenizers, planetary mixers, hobbert mixers, and the like. can.
- the preparation of the slurry for an all-solid-state secondary battery is preferably performed under reduced pressure for at least a part of the step. Thereby, it is possible to prevent bubbles from being generated in the obtained positive electrode active material layer, negative electrode active material layer or solid electrolyte layer.
- the degree of depressurization is preferably about 5.0 ⁇ 10 3 to 5.0 ⁇ 10 5 Pa as an absolute pressure.
- the solid electrolyte sheet according to the present embodiment has a layer formed by applying and drying the above-mentioned slurry for an all-solid secondary battery on a base material.
- the above-mentioned slurry for an all-solid secondary battery is formed on a film as a base material by a blade method (for example, a doctor blade method), a calendar method, a spin coating method, a dip coating method, and the like. It can be produced by applying it by an inkjet method, an offset method, a die coating method, a spray method or the like, drying it to form a layer, and then peeling off the film.
- a film for example, a general film such as a PET film that has been released from the mold can be used.
- the all-solid-state secondary battery slurry containing the solid electrolyte is directly applied to the surface of the green sheet on which the solid-state electrolyte sheet is laminated, or other components of the all-solid-state secondary battery, and dried to solidify. It is also possible to mold an electrolyte sheet.
- the solid electrolyte sheet according to the present embodiment is preferably coated with the above-mentioned slurry for an all-solid secondary battery so that the layer thickness is preferably in the range of 1 to 500 ⁇ m, more preferably 1 to 100 ⁇ m.
- the thickness of the layer is within the above range, conduction ions such as lithium ions easily move, so that the output of the battery increases.
- the thickness of the layer is within the above range, the entire battery can be thinned, so that the capacity per unit volume can be increased.
- the drying of the slurry for an all-solid secondary battery is not particularly limited, and any means such as heat drying, vacuum drying, and heat vacuum drying can be used.
- the dry atmosphere is not particularly limited, and can be performed in an air atmosphere, for example.
- the solid electrolyte sheet contains a positive electrode active material and a solid electrolyte
- the solid electrolyte sheet has a function as a positive electrode active material layer.
- the solid electrolyte sheet contains a negative electrode active material and a solid electrolyte
- the solid electrolyte sheet has a function as a negative electrode active material layer.
- the solid electrolyte sheet does not contain the positive electrode active material and the negative electrode active material and contains the solid electrolyte
- the solid electrolyte sheet has a function as a solid electrolyte layer.
- All-solid-state secondary battery electrode and all-solid-state secondary battery has a current collector and the above-mentioned all-solid-state secondary battery slurry on the surface of the current collector. It comprises an active material layer formed by coating and drying.
- the above-mentioned slurry for an all-solid-state secondary battery is applied to the surface of a current collector such as a metal foil to form a coating film, and then the coating film is dried to form an active material. It can be manufactured by forming a layer.
- the all-solid-state secondary battery electrode produced in this manner is added on the current collector with the above-mentioned polymer (A), anti-aging agent (B), solid electrolyte, and active material, and if necessary. Since the active material layer containing any of the above-mentioned optional components is bound, it is excellent in flexibility, abrasion resistance and powder falling resistance, and exhibits good charge / discharge durability characteristics.
- the current collector for the positive electrode and the negative electrode it is preferable to use an electron conductor that does not cause a chemical change.
- the current collector of the positive electrode aluminum, stainless steel, nickel, titanium, alloys thereof, etc., and those obtained by treating the surface of aluminum, stainless steel with carbon, nickel, titanium, or silver are preferable. Aluminum and aluminum alloys are more preferable.
- the current collector of the negative electrode aluminum, copper, stainless steel, nickel, titanium, and alloys thereof are preferable, and aluminum, copper, and copper alloys are more preferable.
- a film sheet shape is usually used, but a net, a punched body, a lath body, a porous body, a foam body, a molded body of a fiber group, etc. can also be used.
- the thickness of the current collector is not particularly limited, but is preferably 1 ⁇ m to 500 ⁇ m. Further, it is also preferable that the surface of the current collector is made uneven by surface treatment.
- the treatment temperature is preferably 20 to 250 ° C, more preferably 50 to 150 ° C, and the treatment time is 1 to 120 minutes. It is preferably present, and more preferably 5 to 60 minutes.
- the active material layer formed on the current collector may be pressed and compressed.
- a means for press working a high-pressure super press, a soft calendar, a 1-ton press machine, or the like can be used.
- the conditions for press working can be appropriately set according to the processing machine used.
- the active material layer thus formed on the current collector has, for example, a thickness of 40 to 100 ⁇ m and a density of 1.3 to 2.0 g / cm 3 .
- the electrodes for an all-solid secondary battery manufactured in this manner are electrodes in an all-solid secondary battery configured by sandwiching a solid electrolyte layer between a pair of electrodes, specifically, for an all-solid secondary battery. It is preferably used as a positive electrode and / or a negative electrode. Further, the solid electrolyte layer formed by using the above-mentioned slurry for the all-solid secondary battery is suitably used as the solid electrolyte layer for the all-solid secondary battery.
- the all-solid-state secondary battery according to this embodiment can be manufactured by using a known method. Specifically, the following manufacturing method can be used.
- an all-solid-state secondary battery positive electrode slurry containing a solid electrolyte and a positive electrode active material is applied and dried on a current collector to form a positive electrode active material layer, and a positive electrode for an all-solid secondary battery is prepared.
- a slurry for an all-solid-state secondary battery solid electrolyte layer containing a solid electrolyte is applied and dried on the surface of the positive electrode active material layer of the positive electrode for the all-solid-state secondary battery to form a solid electrolyte layer.
- the slurry for the negative electrode of the all-solid secondary battery containing the solid electrolyte and the negative electrode active material is applied and dried on the surface of the solid electrolyte layer to form the negative electrode active material layer.
- the current collector metal foil
- a solid electrolyte sheet is prepared on a release PET film and bonded onto a positive electrode for an all-solid secondary battery or a negative electrode for an all-solid secondary battery prepared in advance. After that, the desired structure of the all-solid-state secondary battery can be obtained by peeling off the release PET.
- the method of applying each of the above compositions may be a conventional method. At this time, it is preferable to perform heat treatment after each coating of the slurry for the positive electrode of the all-solid-state secondary battery, the slurry for the solid electrolyte layer of the all-solid-state secondary battery, and the slurry for the negative electrode of the all-solid-state secondary battery.
- the heating temperature is preferably equal to or higher than the glass transition temperature of the polymer (A).
- the polymer (A) can be softened and its shape can be maintained. As a result, good adhesion and lithium ion conductivity can be obtained in the all-solid-state secondary battery.
- the discharge capacity indicates a value per active material weight of the electrode, and in a half cell, it indicates a value per active material weight of the negative electrode.
- the 1,2-vinyl bond content (unit: mol%) in the polymer is determined by 1 H-NMR at 500 MHz using deuterated chloroform as a solvent. rice field.
- Weight average molecular weight (Mw) It was determined in terms of polystyrene from the retention time corresponding to the apex of the maximum peak of the GPC curve obtained by using gel permeation chromatography (GPC) (trade name "HLC-8120 GPC", manufactured by Tosoh Corporation). (GPC conditions) -Column: 2 product names "GMHXL” (manufactured by Tosoh Corporation) -Column temperature: 40 ° C -Mobile phase: tetrahydrofuran-Flow velocity: 1.0 ml / min-Sample concentration: 10 mg / 20 ml
- the hydrogenation rate of the double bond in the polymer is calculated by measuring 1 H-NMR at 500 MHz using deuterated chloroform as a solvent and calculating ⁇ from the peak area of the obtained spectrum. The value was calculated based on this and used as the hydrogenation rate.
- the hydrogen gas supply pressure was set to 0.7 MPa (gauge pressure)
- the reaction solution was set to 90 ° C.
- the hydrogenation reaction was started by adding a hydrogenation catalyst mainly composed of titanosendichloride to start the hydrogenation reaction, and the modified conjugated diene copolymer.
- a polymer containing a hydrogenated modified conjugated diene copolymer by substituting hydrogen in the reaction vessel when the absorption of hydrogen in the reaction vessel reaches the integrated amount at the target hydrogenation rate (85 mol%).
- a solution was obtained.
- Desolvation was performed to obtain a rubber-like hydrogenated modified conjugated diene-based copolymer. Then, the hydrogenated modified conjugated diene-based copolymer was dried using a heat roll adjusted to 110 ° C. to obtain a polymer (A-2).
- a polymer (A-3) was synthesized by appropriately applying the synthesis method of Synthesis Example 1 above, except that the types and amounts of the components used were as shown in Table 1.
- a polymer (A-4) was synthesized by appropriately applying the synthesis method of Synthesis Example 1 above, except that the types and amounts of the components used were as shown in Table 1.
- a polymer (A-5) was synthesized by appropriately applying the synthesis method of Synthesis Example 2 above, except that the types and amounts of the components used were as shown in Table 1.
- a polymer (A-6) was synthesized by appropriately applying the synthesis method of Synthesis Example 2 above, except that the types and amounts of the components used were as shown in Table 1.
- ⁇ Synthesis example 7> A polymer (A-7) was synthesized by appropriately applying the synthesis method of Synthesis Example 1 above, except that the types and amounts of the components used were as shown in Table 1.
- a polymer (A-8) was synthesized by appropriately applying the synthesis method of Synthesis Example 2 above, except that the types and amounts of the components used were as shown in Table 1.
- ⁇ Synthesis example 9> A polymer (A-9) was synthesized by appropriately applying the synthesis method of Synthesis Example 1 above, except that the types and amounts of the components used were as shown in Table 1.
- a polymer (A-10) was synthesized by appropriately applying the synthesis method of Synthesis Example 2 above, except that the types and amounts of the components used were as shown in Table 1.
- a polymer (A-12) was synthesized by appropriately applying the synthesis method of Synthesis Example 1 above, except that the types and amounts of the components used were as shown in Table 1.
- a polymer (A-13) was synthesized by appropriately applying the synthesis method of Synthesis Example 2 above, except that the types and amounts of the components used were as shown in Table 1.
- a polymer (A-14) which is a copolymer of acrylonitrile and 1,3-butadiene was obtained.
- the polymerization conversion rate was 85%.
- the obtained aqueous dispersion of the copolymer was subjected to steam stripping to remove unreacted monomers, and then concentrated under reduced pressure to adjust the total solid content concentration to 40%.
- 1500 parts of mesitylene was added to the aqueous dispersion of the copolymer and concentrated under reduced pressure to perform solvent substitution, and 1500 ppm of the simmerer GM and 1500 ppm of IPPD were added to 10.1% of the polymer (A-14).
- a mesitylene solution was obtained.
- the polymer (A-14), the weight average molecular weight (Mw) of 214 ⁇ 10 3, 1,2- vinyl bond content was 9 mol%.
- Neostan U-600 (trade name, manufactured by Nitto Kasei, inorganic bismuth) was added over 10 minutes, and the mixture was heated and stirred at 60 ° C. for 5 hours.
- 10 mL of methanol was added to the obtained polymer solution, and the mixture was stirred at 60 ° C. for 1 hour to stop the polymerization.
- the polymer solution was crystallized into 1 L of methanol, and the polymer solid was vacuum dried at 80 ° C. for 6 hours.
- the weight average molecular weight of the obtained polymer (A-15) was 38,000, and the glass transition temperature was 25 ° C. This was redissolved in THF and 1500 ppm of 2,6-di-tert-butyl-p-cresol and 1500 ppm of the simulator GS were added to prepare a 10.1% THF solution.
- Example 1 Preparation of binder composition> The polymer (A-1) obtained in Synthesis Example 1 and 2,6-di-tert-butyl-p-cresol as an antioxidant (B) were added to the binder composition immediately after preparation at 400 ppm. The polymer (A-1) and the anti-aging agent (B) were dissolved in anisole by adding it to anisole, which is a liquid medium (C), and stirring at 90 ° C. for 3 hours to prepare a binder composition.
- anisole anisole
- this binder composition is passed through a cartridge filter having a filter film having an average pore size of 3.00 ⁇ m (manufactured by Advantech, an all-fluororesin cartridge filter, product name “TCF-300-H5MF”), and then magnetically applied.
- a filter manufactured by Tok Engineering Co., Ltd., magnetic flux density 8000 gauss was transmitted.
- the whole binder composition was 100% by mass, the total solid content was 10.1%.
- the concentration of the anti-aging agent immediately after the preparation of the binder composition was measured by the above method, it was 600 ppm.
- ⁇ Viscosity of binder composition> Within 5 minutes after the preparation of the binder composition obtained above, the viscosity was measured at 25 ° C. with a B-type viscometer (manufactured by Toki Sangyo Co., Ltd.) at 50 rpm.
- binder composition immediately after preparation is a 1 L clean barrier (registered trademark) bottle (barrier container for ultra-high purity solvent) commercially available from Aicello Chemical Corporation. ) Was filled with 500 g and stored in a constant temperature bath set at 40 ° C. for 6 months.
- ⁇ Mw is 97% or more and less than 103%.
- B ⁇ Mw is 95% or more and less than 97% or 103% or more and less than 105%.
- C ⁇ Mw is less than 95% or 105% or more.
- the "binder composition” in the subsequent operations of the examples means either one of the above-mentioned "binder composition immediately after preparation” and the above-mentioned "binder composition after long-term storage”.
- Table 1 below shows the characteristics of the all-solid-state secondary battery manufactured using the binder composition immediately after preparation (“Characteristics of power storage device (immediately after manufacturing)” in Table 1 below) and after long-term storage.
- the results showing the characteristics of the all-solid-state secondary battery manufactured by using the binder composition (“Characteristics of power storage device (after long-term storage)” in Table 1 below) are described separately.
- the mixture was mixed with a rotating and revolving mixer (manufactured by THINKY, Awatori Rentaro ARV-310) for 10 minutes to prepare a slurry for the positive electrode of an all-solid secondary battery.
- a rotating and revolving mixer manufactured by THINKY, Awatori Rentaro ARV-310
- ⁇ Preparation of slurry for solid-state secondary battery solid electrolyte layer> 100 parts by mass of sulfide glass (Li 2 S / P 2 S 5 75 mol% / 25 mol%, average particle diameter 5 ⁇ m) composed of Li 2 S and P 2 S 5 as a solid electrolyte, and the binder composition prepared above.
- ⁇ Preparation of slurry for negative electrode of all-solid-state secondary battery> 65 parts by mass of artificial graphite (average particle size: 20 ⁇ m) as a negative electrode active material, sulfide glass composed of Li 2 S and P 2 S 5 as a solid electrolyte (Li 2 S / P 2 S 5 75 mol% / 25 mol%, (Average particle size 5 ⁇ m) 35 parts by mass, the binder composition prepared above is mixed with 2 parts by mass equivalent to the solid content, and anisole is further added as a liquid medium to adjust the solid content concentration to 65%, and then the rotation revolves.
- a slurry for the negative electrode of an all-solid secondary battery was prepared by mixing with a mixer (manufactured by THINKY, Awatori Rentaro ARV-310) for 10 minutes.
- Viscosity change rate ⁇ (%) ( ⁇ 1 / ⁇ 0 ) ⁇ 100 was calculated and evaluated according to the following criteria. The smaller the viscosity change rate ⁇ , the better the slurry stability. (Evaluation criteria) AA: ⁇ is 80% or more and less than 120%. A: ⁇ is 70% or more and less than 80% or 120% or more and less than 130%. B: ⁇ is 60% or more and less than 70% or 130% or more and less than 140%. C: ⁇ is less than 60% or 140% or more.
- the all-solid-state secondary battery positive electrode slurry prepared above is applied onto an aluminum foil by the doctor blade method, and anisole is evaporated under reduced pressure at 120 ° C. and dried over 3 hours to dry a positive electrode having a thickness of 0.1 mm.
- An all-solid-state secondary battery positive electrode on which an active material layer was formed was produced.
- the slurry for the solid electrolyte of the all-solid-state secondary battery prepared above was applied onto the release PET film by the doctor blade method, and the anisole was evaporated under reduced pressure at 120 ° C. and dried over 3 hours to obtain a thickness of 0.
- a 1 mm solid electrolyte layer was prepared.
- the slurry for the negative electrode of the all-solid-state secondary battery prepared above is applied onto the stainless steel foil by the doctor blade method, and the anisole is evaporated under reduced pressure at 120 ° C. and dried over 3 hours to dry the negative electrode having a thickness of 0.1 mm.
- An all-solid-state secondary battery negative electrode on which an active material layer was formed was produced.
- Lithium ion conductivity is 0.5 ⁇ 10 -4 S / cm or more and less than 0.8 ⁇ 10 -4 S / cm.
- the positive electrode of the all-solid-state secondary battery prepared above was cut out into a disk shape having a diameter of 13 mm, and the negative electrode of the all-solid-state secondary battery and the solid electrolyte layer peeled off from the PET film were cut out into a disk shape having a diameter of 15 mm.
- the cut out all-solid-state secondary battery positive electrode was attached to one surface of the cut-out solid electrolyte layer so that the surface of the positive electrode active material layer of the all-solid-state secondary battery positive electrode was in contact with the solid electrolyte layer.
- the cut out all-solid secondary battery negative electrode is attached to the other side of the cut out solid electrolyte layer so that the surface of the negative electrode active material layer of the all-solid secondary battery negative electrode is in contact with the solid electrolyte layer, and a heat press machine is used. Then, pressurize while heating (120 ° C.) (600 MPa, 1 minute), and have a laminated structure of aluminum foil / positive electrode active material layer / solid electrolyte layer / negative electrode active material layer / stainless steel foil. It was created. Next, the all-solid-state secondary battery laminate thus created is placed in a stainless steel 2032-inch coin case incorporating a spacer and washer, and the 2032-inch coin case is crimped to create an all-solid-state secondary battery. bottom.
- Capacity retention rate after 20 cycles (%) (B / A) x 100
- C in the C rate is a time rate, and is defined as (1 / X)
- C rated capacity (Ah) / X (h).
- X represents the time required to charge or discharge the rated capacity of electricity.
- 0.1C means that the current value is the rated capacity (Ah) / 10 (h).
- AA Capacity retention rate is 95% or more and 100% or less.
- C Capacity retention rate is less than 85%.
- a binder composition for the all-solid-state secondary battery containing an active material and a solid electrolyte is used as the slurry for the all-solid-state secondary battery electrode. Then, in the active material layer formed by the slurry, the active material layer itself becomes brittle when the peel strength is measured, and the active material and the solid electrolyte do not fall off or cracks occur, and the active material and the solid electrolyte do not occur. It was confirmed that sufficient binding property was obtained for the polymer in any of the above.
- the active material layer formed by using the binder composition for an all-solid-state secondary battery according to the present invention has sufficient adhesion to the solid electrolyte layer, and the all-solid-state secondary battery according to the present invention. It is presumed that high workability can be obtained even when the solid electrolyte layer is formed by using the binder composition for use, and that the solid electrolyte formed has sufficient adhesion to the active material layer.
- the present invention is not limited to the above embodiment, and various modifications are possible.
- the present invention includes substantially the same configurations as those described in the embodiments (eg, configurations with the same function, method and result, or configurations with the same purpose and effect).
- the present invention also includes a configuration in which a non-essential part of the configuration described in the above embodiment is replaced with another configuration.
- the present invention also includes a configuration that exhibits the same effects as the configuration described in the above embodiment or a configuration that can achieve the same object.
- the present invention also includes a configuration in which a known technique is added to the configuration described in the above embodiment.
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Abstract
Description
芳香族ビニル化合物に基づく芳香族ビニル単位と、共役ジエン化合物に基づく共役ジエン単位と、を有する重合体(A)と、
老化防止剤(B)を全固体二次電池用バインダー組成物の全質量に対して200ppm以上5,000ppm以下と、
液状媒体(C)と、
を含有する。
前記老化防止剤(B)が、フェノール系老化防止剤及びアミン系老化防止剤よりなる群から選ばれる少なくとも1種を含んでもよい。
前記重合体(A)が、下記式(1)で表される構造単位、下記式(2)で表される構造単位、下記式(3)で表される構造単位、及び下記式(4)で表される構造単位の重合体中の構成比(モル比)をそれぞれp、q、r、sとしたとき、下記数式(i)で表される値αが0.9未満であってもよい。
α=(p+(0.5×r))/(p+q+(0.5×r)+s) ・・・(i)
前記重合体(A)の結合スチレン含量が5~40%であってもよい。
前記重合体(A)が、窒素原子、酸素原子、ケイ素原子、ゲルマニウム原子及びスズ原子よりなる群から選ばれる少なくとも1種の原子を含む変性剤に基づく単位を有してもよい。
前記液状媒体(C)が、脂肪族炭化水素、脂環式炭化水素、芳香族炭化水素、ケトン類、エステル類及びエーテル類よりなる群から選ばれる少なくとも1種であってもよい。
前記重合体(A)が前記液状媒体(C)に溶解してなるものであってもよい。
前記いずれかの態様の全固体二次電池用バインダー組成物と、固体電解質とを含有する。
前記固体電解質として、硫化物系固体電解質又は酸化物系固体電解質を含有してもよい。
正極活物質層と、固体電解質層と、負極活物質層とを少なくとも備え、
前記正極活物質層、前記固体電解質層、及び前記負極活物質層の少なくともいずれか1層が、前記いずれかの態様の全固体二次電池用スラリーを塗布及び乾燥させて形成された層である。
基材上に、前記いずれかの態様の全固体二次電池用スラリーを塗布及び乾燥させて形成された層を有するものである。
前記いずれかの態様の全固体二次電池用スラリーを基材上に塗布及び乾燥させる工程を含む。
前記態様の全固体二次電池用固体電解質シートの製造方法を介して全固体二次電池を製造する方法である。
本実施形態に係る全固体二次電池用バインダー組成物は、芳香族ビニル化合物に基づく芳香族ビニル単位と、共役ジエン化合物に基づく共役ジエン単位と、を有する重合体(A)と、老化防止剤(B)を全固体二次電池用バインダー組成物の全質量に対して200ppm以上5,000ppm以下と、液状媒体(C)と、を含有する。本実施形態に係る全固体二次電池用バインダー組成物は、本発明の効果を損なわない範囲において、任意成分をさらに含有していてもよい。以下、本実施形態に係る全固体二次電池用バインダー組成物に含まれる各成分について詳細に説明する。
本実施形態に係る全固体二次電池用バインダー組成物は、重合体(A)を含有する。重合体(A)は、芳香族ビニル化合物に基づく芳香族ビニル単位と、共役ジエン化合物に基づく共役ジエン単位とを有する。重合体(A)は、前記芳香族ビニル単位及び前記共役ジエン単位のほかに、それと共重合可能な他の単量体に基づく構造単位を含有してもよい。重合体(A)の構造単位の配列順については、特に限定されない。すなわち、重合体(A)は、ブロック共重合体であってもよく、ランダム共重合体であってもよい。
重合体(A)は、例えば、芳香族ビニル化合物及び共役ジエン化合物を重合して活性末端を有する共役ジエン系共重合体を得る工程(重合工程)、得られた共役ジエン系共重合体の末端を変性する工程(変性工程)、及び共役ジエン系共重合体を水素添加する工程(水添工程)を含む方法により製造することができる。具体的には、国際公開第2014/133097号に記載された方法に従って、使用目的に合うように、分子量、芳香族ビニル化合物量、ビニル結合の含有量、水添率、変性剤の種類等を適宜変更して製造することができる。以下、重合体(A)の製造方法について詳細に説明する。
重合工程は、芳香族ビニル化合物と共役ジエン化合物とを含むモノマーを重合して、活性末端を有する共役ジエン系共重合体を得る工程である。共役ジエン系共重合体を得るための重合法としては、溶液重合法、気相重合法、バルク重合法のいずれを用いてもよいが、溶液重合法が特に好ましい。また、重合形式としては、回分式及び連続式のいずれを用いてもよい。溶液重合法を用いる場合、具体的な重合方法の一例としては、有機溶媒中において、芳香族ビニル化合物及び共役ジエン化合物を含むモノマーを、重合開始剤及び必要に応じて用いられるビニル制御剤(以下、「ランダマイザー」ともいう。)の存在下、重合を行う方法が挙げられる。
変性工程は、上記重合工程により得られた共役ジエン系共重合体の活性末端と、重合終了末端に集電体や固体電解質等と相互作用する官能基を導入する化合物(以下、「化合物(C2)」ともいう。)と、を反応させる工程である。この工程により、共役ジエン系共重合体の重合終了末端に、集電体や固体電解質等と相互作用する官能基を導入することができる。なお、本明細書において活性末端とは、分子鎖の端に存在する、炭素-炭素二重結合を有するモノマーに由来する構造以外の部分(より具体的には炭素アニオン)を意味する。
(式(5)中、A1は、窒素、リン、酸素、硫黄及びケイ素からなる群より選択される少なくとも一種の原子を有し、かつR5に対して窒素原子、リン原子、酸素原子、硫黄原子、ケイ素原子若しくはカルボニル基に含まれる炭素原子で結合する1価の官能基であるか、又は(チオ)エポキシ基である。R3及びR4はヒドロカルビル基であり、R5はヒドロカルビレン基であり、rは0~2の整数である。ただし、R3及びR4が複数存在する場合、複数のR3及びR4は、それぞれ同じでも異なっていてもよい。)
(式(6)中、A2は、窒素、リン、酸素、硫黄及びケイ素からなる群より選択される少なくとも一種の原子を有し、活性水素を有さず、かつR9に対して窒素原子、リン原子、酸素原子、硫黄原子又はケイ素原子で結合する1価の官能基である。R6及びR7は、それぞれ独立してヒドロカルビル基であり、R8及びR9は、それぞれ独立してヒドロカルビレン基であり、mは0又は1である。ただし、R7が複数存在する場合、複数のR7は、それぞれ同じでも異なっていてもよい。)
重合体(A)は、上記で得られた変性又は未変性の共役ジエン系共重合体を水素添加したものであってもよい。水添反応の方法及び条件は、所望の水添率の共役ジエン系共重合体が得られるのであれば、いずれの方法及び条件を用いることも可能である。それらの水添方法の例としては、チタンの有機金属化合物を主成分とする触媒を水添触媒として使用する方法;鉄、ニッケル、コバルトの有機化合物とアルキルアルミニウム等の有機金属化合物からなる触媒を使用する方法;ルテニウム、ロジウム等の有機金属化合物の有機錯体を使用する方法;パラジウム、白金、ルテニウム、コバルト、ニッケル等の金属を、カーボン、シリカ、アルミナ等の担体に担持した触媒を使用する方法などがある。各種の方法の中では、チタンの有機金属化合物単独、またはチタンの有機金属化合物とリチウム、マグネシウム、アルミニウムの有機金属化合物とから成る均一触媒(特公昭63-4841号公報、特公平1-37970号公報、特開2000-37632号公報)を用い、低圧、低温の穏和な条件で水添する方法は工業的に好ましく、またブタジエンの二重結合への水添選択性も高く本発明の目的に適している。
α=(p+(0.5×r))/(p+q+(0.5×r)+s) ・・・(i)
αを0.9未満とすることにより、スラリーの分散安定性及び電極の柔軟性に優れると共に、高いリチウムイオン伝導性及び良好なサイクル寿命特性を実現することができる。このような理由から、αは0.9未満であることが好ましく、0.8未満であることがより好ましく、0.7未満であることが特に好ましい。なお、上記数式(i)のαは、共役ジエン系共重合体の水添率に相当する。例えば、αが0.6の場合、共役ジエン系共重合体の水添率は60%である。また、αは0であってもよい。共役ジエン系共重合体中の水添率は、水添反応の時間又は水素の供給量等により調整することができる。この水添率は1H-NMRにより測定することができる。
<結合スチレン含量>
重合体(A)の結合スチレン含量は、好ましくは5~40%であり、より好ましくは8~30%であり、特に好ましくは10~27%である。重合体(A)の結合スチレン含量が上記範囲内であると、電極の密着性と柔軟性との両立を図ることができる。なお、結合スチレン含量は、1H-NMR測定によって測定することができる。
重合体(A)の重量平均分子量(Mw)は、好ましくは1.0×105~2.0×106であり、より好ましくは1.0×105~1.5×106であり、特に好ましくは1.5×105~1.0×106である。重量平均分子量(Mw)が上記下限値以上であると、電極の密着性が向上しやすい傾向にある。重量平均分子量(Mw)が上記上限値以下であると、電極の柔軟性が保たれる傾向にある。なお、本明細書において、「重量平均分子量(Mw)」とは、ゲルパーミエーションクロマトグラフィー(GPC)により測定したポリスチレン換算の重量平均分子量のことをいう。
重合体(A)は、後述する液状媒体(C)に溶解した状態であることが好ましい。「重合体(A)が液状媒体(C)に溶解する」とは、重合体(A)の液状媒体(C)に対する溶解度が、液状媒体(C)100gに対し1g以上であることを意味する。重合体(A)が液状媒体(C)に溶解した状態であることにより、柔軟性や密着性に優れる重合体(A)によって活物質の表面がコーティングされやすくなるので、充放電時における活物質の伸縮による脱落を効果的に抑制でき、良好な充放電耐久特性を示す全固体二次電池が得られやすい。また、スラリーの安定性が良好となり、スラリーの集電体への塗布性も良好となるため好ましい。
本実施形態に係る全固体二次電池用バインダー組成物は、該バインダー組成物の全質量に対し、老化防止剤(B)を200ppm以上5,000ppm以下含有する。老化防止剤(B)を前記濃度範囲内で含有することにより、該バインダー組成物中の重合体(A)の劣化を抑制できる。
液状媒体(C)としては、特に限定されないが、ヘキサン、ヘプタン、オクタン、デカン、ドデカン等の脂肪族炭化水素;シクロヘキサン、シクロヘプタン、シクロオクタン、シクロデカン等の脂環式炭化水素;トルエン、キシレン、メシチレン、ナフタレン、テトラリン等の芳香族炭化水素;3-ペンタノン、4-ヘプタノン、メチルヘキシルケトン、ジイソブチルケトン等のケトン類;酢酸ブチル、酪酸ブチル、ブタン酸メチル、ペンタン酸ブチル、ヘキサン酸ブチル、酪酸ペンチル、ペンタン酸ペンチル、ヘキサン酸ペンチル、酪酸ヘキシル、ペンタン酸ヘキシル、ヘキサン酸ヘキシル等のエステル類;ジブチルエーテル、テトラヒドロフラン、アニソール等のエーテル類などを用いることができる。これらの溶媒は、1種単独であるいは2種類以上を組み合わせて用いることができる。
本実施形態に係る全固体二次電池用バインダー組成物は、必要に応じて、増粘剤等の添加剤を含有してもよい。
増粘剤を含有することにより、その塗布性や得られる全固体二次電池の充放電特性を更に向上できる場合がある。
本実施形態に係る全固体二次電池用バインダー組成物は、重合体(A)に、老化防止剤(B)及び液状媒体(C)を加え、必要に応じてその他の添加剤を更に加え、適宜撹拌を行って重合体(A)及び老化防止剤(B)を液状媒体(C)中に溶解させる工程により調製することができる。
本実施形態に係る全固体二次電池用スラリーは、上述の全固体二次電池用バインダー組成物と、固体電解質とを含有する。本実施形態に係る全固体二次電池用スラリーは、正極活物質層及び負極活物質層のいずれの活物質層を形成するための材料として使用することもできるし、また固体電解質層を形成するための材料として使用することもできる。
<正極活物質>
正極活物質としては、例えば、MnO2、MoO3、V2O5、V6O13、Fe2O3、Fe3O4、Li(1-x)CoO2、Li(1-x)NiO2、LixCoySnzO2、Li(1-x)Co(1-y)NiyO2、Li(1+x)Ni1/3Co1/3Mn1/3O2、TiS2、TiS3、MoS3、FeS2、CuF2、NiF2等の無機化合物;フッ化カーボン、グラファイト、気相成長炭素繊維及び/又はその粉砕物、PAN系炭素繊維及び/又はその粉砕物、ピッチ系炭素繊維及び/又はその粉砕物等の炭素材料;ポリアセチレン、ポリ-p-フェニレン等の導電性高分子などを用いることができる。これらの正極活物質は、1種を単独で用いてもよく、又は2種以上組み合わせて用いてもよい。
負極活物質としては、可逆的にリチウムイオン等を吸蔵・放出できるものであれば特に限定されないが、例えば炭素質材料、酸化錫や酸化ケイ素等の金属酸化物、リチウム単体やリチウムアルミニウム合金等のリチウム合金、Sn、Si若しくはIn等のリチウムと合金形成可能な金属等が挙げられる。中でも、信頼性の点から炭素質材料が、電池容量を大きくできる点からケイ素含有材料が、好ましく用いられる。
本実施形態に係る全固体二次電池用スラリーは、固体電解質を含有する。固体電解質としては、一般に全固体二次電池に使用される固体電解質を適宜選択して用いることができるが、硫化物系固体電解質又は酸化物系固体電解質であることが好ましい。
硫化物系固体電解質は、硫黄原子(S)及び周期表第1族又は第2族の金属元素を含み、イオン伝導性を有し、かつ、電子絶縁性を有するものが好ましい。このような硫化物系固体電解質としては、例えば、下記一般式(7)で表される組成式の硫化物系固体電解質が挙げられる。
LiaMbPcSd ・・・・・(7)
(式(7)中、Mは、B、Zn、Si、Cu、Ga及びGeから選択される元素を表す。a~dは各元素の組成比を表し、a:b:c:d=1~12:0~1:1:2~9を満たす。)
酸化物系固体電解質は、酸素原子(O)及び周期表第1族又は第2族の金属元素を含み、イオン伝導性を有し、かつ、電子絶縁性を有するものが好ましい。このような酸化物系固体電解質としては、例えば、LixaLayaTiO3〔xa=0.3~0.7、ya=0.3~0.7〕(LLT)、Li7La3Zr2O12(LLZ)、LISICON(Lithium super ionic conductor)型結晶構造を有するLi3.5Zn0.25GeO4、NASICON(Natrium super ionic conductor)型結晶構造を有するLiTi2P3O12、Li(1+xb+yb)(Al,Ga)xb(Ti,Ge)(2-xb)SiybP(3-yb)O12(ただし、0≦xb≦1、0≦yb≦1)、ガーネット型結晶構造を有するLi7La3Zr2O12が挙げられる。
本実施形態に係る全固体二次電池用スラリーは、前述した成分以外に、必要に応じてその他の添加剤を含有してもよい。その他の添加剤としては、例えば、導電付与剤、増粘剤、液状媒体(ただし、全固体二次電池用バインダー組成物からの持ち込み分を除く。)等が挙げられる。
導電付与剤は、電子の導電性を助ける効果を有するため、正極活物質層又は負極活物質層を形成するための全固体二次電池用スラリーに添加される。導電付与剤の具体例としては、活性炭、アセチレンブラック、ケッチェンブラック、ファーネスブラック、黒鉛、炭素繊維、フラーレン等のカーボンが挙げられる。これらの中でも、アセチレンブラック、ファーネスブラックが好ましい。本実施形態に係る全固体二次電池用スラリーが導電付与剤を含有する場合、導電付与剤の含有割合は、活物質100質量部に対して、20質量部以下であることが好ましく、1~15質量部であることがより好ましく、2~10質量部であることが特に好ましい。
増粘剤の具体例としては、上述の「1.4.その他の添加剤」の<増粘剤>の項で例示した増粘剤が挙げられる。本実施形態に係る全固体二次電池用スラリーが増粘剤を含有する場合、増粘剤の含有割合は、全固体二次電池用スラリーの全固形分量100質量部に対して、5質量部以下であることが好ましく、0.1~3質量部であることがより好ましい。
液状媒体の具体例としては、上述の「1.3.液状媒体(C)」の項で例示した液状媒体(C)と同様の液状媒体が挙げられる。本実施形態に係る全固体二次電池用スラリーに液状媒体を添加する場合、全固体二次電池用バインダー組成物に含まれる液状媒体(C)と同一の液状媒体を添加してもよく、異なる液状媒体を添加してもよいが、同一の液状媒体を添加することが好ましい。本実施形態に係る全固体二次電池用スラリー中の液状媒体の含有割合は、その塗布性を良好なものとし、塗布後の乾燥処理における重合体(A)や活物質の濃度勾配を抑制するために、任意の割合に調整することができる。
本実施形態に係る全固体二次電池用スラリーは、上述の全固体二次電池用バインダー組成物と固体電解質とを含有するものである限り、どのような方法によって製造されたものであってもよい。
本実施形態に係る固体電解質シートは、基材上に上述の全固体二次電池用スラリーを塗布及び乾燥させて形成された層を有するものである。
本実施形態に係る全固体二次電池用電極は、集電体と、前記集電体の表面上に上述の全固体二次電池用スラリーが塗布及び乾燥されて形成された活物質層と、を備えるものである。かかる全固体二次電池用電極は、金属箔などの集電体の表面に、上述の全固体二次電池用スラリーを塗布して塗膜を形成し、次いで該塗膜を乾燥して活物質層を形成することにより製造することができる。このようにして製造された全固体二次電池用電極は、集電体上に、上述の重合体(A)、老化防止剤(B)、固体電解質、及び活物質、さらに必要に応じて添加した任意成分を含有する活物質層が結着されてなるものであるから、柔軟性、耐擦性及び粉落ち耐性に優れるとともに、良好な充放電耐久特性を示す。
以下、本発明を実施例に基づいて具体的に説明するが、本発明はこれらの実施例に限定されるものではない。実施例、比較例中の「部」及び「%」は、特に断らない限り質量基準である。
以下の実施例及び比較例において、各物性値の測定法は以下の通りである。
重合体中の1,2-ビニル結合含有量(単位:モル%)は、重水素化クロロホルムを溶媒として用い、500MHzの1H-NMRにより求めた。
重合体中の結合スチレン含量(単位:%)は、重水素化クロロホルムを溶媒として用い、500MHzの1H-NMRにより求めた。
ゲルパーミエーションクロマトグラフィー(GPC)(商品名「HLC-8120GPC」、東ソー株式会社製)を使用して得られたGPC曲線の最大ピークの頂点に相当する保持時間から、ポリスチレン換算で求めた。
(GPCの条件)
・カラム:商品名「GMHXL」(東ソー社製)2本
・カラム温度:40℃
・移動相:テトラヒドロフラン
・流速:1.0ml/分
・サンプル濃度:10mg/20ml
重合体における二重結合の水素添加率は、重水素化クロロホルムを溶媒として用い、500MHzの1H-NMRを測定し、得られたスペクトルのピーク面積からαの計算式に基づき値を算出し、水素添加率とした。
後述のようにして得られた全固体二次電池用バインダー組成物10gを撹拌した100mLのメタノール中に投入して重合体を沈殿させた。ステンレスメッシュを用いて沈殿した重合体を濾別して、得られた濾液について液体クロマトグラフィー(HPLC)による分析を行った。液体クロマトグラフィーのための液体クロマトグラフには、島津製作所株式会社製の商品名「CBM-20A」を用いた。HPLCの条件は、以下の通りとした。
(HPLCの条件)
・流速:1mL/min
・カラムオーブン温度:40℃
・検出器:吸光度検出器(280nmにおける吸光度を計測)
・溶離液:メタノール(MeOH)と水との混合液(MeOH/水=9/1)
<合成例1>
窒素置換された内容積50リットルのオートクレーブ反応器に、炭化水素溶媒としてのシクロヘキサン25kg、ビニル制御剤としてのテトラヒドロフラン75g、スチレン600g、1,3-ブタジエン1800gを仕込んだ。反応器内容物の温度を10℃に調整した後、重合開始剤としてのn-ブチルリチウム27.4mmolを添加して重合を開始した。重合は断熱条件で実施し、最高温度は85℃に達した。重合転化率が99%に達した時点(重合開始から26分経過後)で、1,3-ブタジエン100gを2分間かけて追加し、更に3分間重合させた後、四塩化スズ4mmolを加えて30分間反応を行い、更にN,N-ビス(トリメチルシリル)アミノプロピルメチルジエトキシシラン(BTADS)11.4mmolを加えて30分間反応を行って、変性共役ジエン系共重合体を含む重合体溶液を得た。
窒素置換された内容積50リットルのオートクレーブ反応器に、炭化水素溶媒としてのシクロヘキサン25kg、ビニル制御剤としてのテトラヒドロフラン30g、スチレン600g、1,3-ブタジエン1800gを仕込んだ。反応器内容物の温度を10℃に調整した後、重合開始剤としてのn-ブチルリチウム27.4mmolを添加して重合を開始した。重合は断熱条件で実施し、最高温度は85℃に達した。重合転化率が99%に達した時点(重合開始から26分経過後)で、1,3-ブタジエン100gを2分間かけて追加し、更に3分間重合させた後、四塩化スズ2mmolを加えて30分間反応を行い、更にN-トリメチルシリル-N-メチルアミノプロピルメチルジエトキシシラン(TMADS)19.4mmolを加えて30分間反応を行って、変性共役ジエン系共重合体を含む重合体溶液を得た。
使用する成分の種類及び量をそれぞれ表1に記載の通りとした以外は、上記合成例1の合成方法を適宜応用して重合体(A-3)を合成した。重合体(A-3)の、重量平均分子量(Mw)は331×103であり、1,2-ビニル結合含量は62モル%であった。
使用する成分の種類及び量をそれぞれ表1に記載の通りとした以外は、上記合成例1の合成方法を適宜応用して重合体(A-4)を合成した。重合体(A-4)の、重量平均分子量(Mw)は284×103であり、1,2-ビニル結合含量は40モル%であった。
使用する成分の種類及び量をそれぞれ表1に記載の通りとした以外は、上記合成例2の合成方法を適宜応用して重合体(A-5)を合成した。重合体(A-5)の、重量平均分子量(Mw)は278×103であり、1,2-ビニル結合含量は42モル%であり、水素添加率は80モル%であった。
使用する成分の種類及び量をそれぞれ表1に記載の通りとした以外は、上記合成例2の合成方法を適宜応用して重合体(A-6)を合成した。重合体(A-6)の、重量平均分子量(Mw)は354×103であり、1,2-ビニル結合含量は41モル%であり、水素添加率は81モル%であった。
使用する成分の種類及び量をそれぞれ表1に記載の通りとした以外は、上記合成例1の合成方法を適宜応用して重合体(A-7)を合成した。重合体(A-7)の、重量平均分子量(Mw)は311×103であり、1,2-ビニル結合含量は42モル%であった。
使用する成分の種類及び量をそれぞれ表1に記載の通りとした以外は、上記合成例2の合成方法を適宜応用して重合体(A-8)を合成した。重合体(A-8)の、重量平均分子量(Mw)は299×103であり、1,2-ビニル結合含量は43モル%であり、水素添加率は85モル%であった。
使用する成分の種類及び量をそれぞれ表1に記載の通りとした以外は、上記合成例1の合成方法を適宜応用して重合体(A-9)を合成した。重合体(A-9)の、重量平均分子量(Mw)は387×103であり、1,2-ビニル結合含量は41モル%であった。
使用する成分の種類及び量をそれぞれ表1に記載の通りとした以外は、上記合成例2の合成方法を適宜応用して重合体(A-10)を合成した。重合体(A-10)の、重量平均分子量(Mw)は349×103であり、1,2-ビニル結合含量は41モル%であり、水素添加率は86モル%であった。
窒素置換された内容積50リットルのオートクレーブ反応器に、炭化水素溶媒としてのシクロヘキサン25kg、ビニル制御剤としてのテトラヒドロフラン75g、スチレン400g、1,3-ブタジエン2000gを仕込んだ。反応器内容物の温度を10℃に調整した後、重合開始剤としてのn-ブチルリチウム27.4mmolを添加して重合を開始した。重合は断熱条件で実施し、最高温度は85℃に達した。重合転化率が99%に達した時点(重合開始から26分経過後)で、1,3-ブタジエン100gを2分間かけて追加し、更に3分間重合させて共役ジエン系共重合体を含む重合体溶液を得た。
使用する成分の種類及び量をそれぞれ表1に記載の通りとした以外は、上記合成例1の合成方法を適宜応用して重合体(A-12)を合成した。重合体(A-12)の、重量平均分子量(Mw)は342×103であり、1,2-ビニル結合含量は61モル%であった。
使用する成分の種類及び量をそれぞれ表1に記載の通りとした以外は、上記合成例2の合成方法を適宜応用して重合体(A-13)を合成した。重合体(A-13)の、重量平均分子量(Mw)は505×103であり、1,2-ビニル結合含量は41モル%であり、水素添加率は95モル%であった。
撹拌機付きのオートクレーブ反応器に、イオン交換水240部、乳化剤としてのアルキルベンゼンスルホン酸ナトリウム2.5部、ニトリル基含有単量体としてのアクリロニトリル35部、連鎖移動剤としてのtert-ドデシルメルカプタン0.25部をこの順で入れ、内部を窒素置換した後、共役ジエン単量体としての1,3-ブタジエン65部を圧入し、重合開始剤としての過硫酸アンモニウム0.25部を添加して、反応温度40℃で重合反応させた。そして、アクリロニトリルと1,3-ブタジエンとの共重合体である重合体(A-14)を得た。なお、重合転化率は85%であった。得られた共重合体の水分散液にスチームストリッピングを行い、未反応の単量体を除去した後、減圧濃縮を行い、全固形分濃度を40%に調整した。次に、共重合体の水分散液にメシチレン1500部を加えて減圧濃縮を行うことで溶剤置換を行い、スミライザーGM 1500ppmとIPPD 1500ppmを加えて、重合体(A-14)の10.1%メシチレン溶液を得た。重合体(A-14)の、重量平均分子量(Mw)は214×103であり、1,2-ビニル結合含量は9モル%であった。
200mLの3口フラスコに、ジシクロヘキシルメタン-4,4'-ジイソシアネート13.2g、1,4-ブタンジオール0.9g、DURANOLT5650J(旭化成社製、質量平均分子量800)24g、2,2-(ビスヒドロキシメチル)ブタン酸1.5gを加え、さらにテトラヒドロフラン56gを加えて60℃で加熱溶解した。これに触媒としてネオスタンU-600(商品名、日東化成製、無機ビスマス)50mgを10分間かけて加え、5時間60℃で加熱攪拌した。得られた重合体溶液にメタノール10mLを加えて1時間60℃で撹拌し重合を停止させた。この重合体溶液をメタノール1Lに晶析させ、ポリマー固体を80℃で6時間真空乾燥した。得られた重合体(A-15)の重量平均分子量は38,000、ガラス転移温度は25℃であった。これをTHFに再溶解させて、2,6-ジ-tert-ブチル-p-クレゾール1500ppmとスミライザーGS1500ppmを加えて、10.1%THF溶液とした。
メタノール10mLに代えてEPOL(登録商標、出光興産社製)1.9gを用いた以外は合成例15と同様にして、1時間60℃で撹拌し重合を行った。得られた重合体溶液をオクタン500mLに滴下し分散させた。これを減圧濃縮後、2,6-ジ-tert-ブチル-p-クレゾール1500ppmとスミライザーGS1500ppmを加えて、オクタンに分散された10.2%ポリウレタンラテックスを得た。得られた重合体(A-16)の重量平均分子量は17,000、ガラス転移温度は15℃、ラテックスの平均粒子径は190nmであった。
<バインダー組成物の調製>
合成例1で得た重合体(A-1)と、老化防止剤(B)として2,6-ジ-tert-ブチル-p-クレゾールを、調製直後のバインダー組成物に対して400ppmと、を液状媒体(C)であるアニソール中に添加し、90℃で3時間撹拌することにより、重合体(A-1)と老化防止剤(B)をアニソールに溶解させ、バインダー組成物を調製した。その後、このバインダー組成物を、平均孔径が3.00μmであるフィルター膜を有するカートリッジフィルター(アドバンテック社製、オールフッ素樹脂カートリッジフィルター、製品名「TCF-300-H5MF」)を透過させた後、磁気フィルター(トックエンジニアリング株式会社製、磁束密度8000ガウス)を透過させた。このバインダー組成物全体を100質量%としたときの、全固形分は10.1%であった。また、上記の方法により、バインダー組成物調製直後の老化防止剤の濃度を測定したところ、600ppmであった。
上記で得られたバインダー組成物を調製後5分以内に、50rpmのB型粘度計(東機産業株式会社製)により25℃にて粘度測定を行った。
上記で調製したバインダー組成物(以下、「調製直後のバインダー組成物」ともいう。)をアイセロ化学株式会社より市販されている1Lのクリーンバリア(登録商標)ボトル(超高純度溶剤用バリア性容器)に500g充填し、40℃に設定した恒温槽で6ヶ月間貯蔵した。6ヶ月間貯蔵後のバインダー組成物(以下、「長期貯蔵後のバインダー組成物」ともいう。)の重量平均分子量(Mw1)を、ゲルパーミエーションクロマトグラフィー(GPC:温度条件50℃、カラム:東ソー株式会社製「GMHHR-H」、ポリスチレン換算)によって測定を行い、貯蔵前の重量平均分子量(Mw0)と貯蔵後の重量平均分子量(Mw1)の変化率ΔMw(%)=(Mw1/Mw0)×100を算出し、下記基準により評価した。重量平均分子量の変化率ΔMwが小さいものほどバインダー組成物の貯蔵安定性に優れる。
(評価基準)
A :ΔMwが97%以上103%未満。
B :ΔMwが95%以上97%未満または103%以上105%未満。
C :ΔMwが95%未満または105%以上。
正極活物質としてLiCoO2(平均粒子径:10μm)70質量部と、固体電解質としてLi2SとP2S5からなる硫化物ガラス(Li2S/P2S5=75mol%/25mol%、平均粒子径5μm)30質量部と、導電助剤としてアセチレンブラック2質量部と、上記で調製したバインダー組成物を固形分相当で2質量部とを混合し、さらに液状媒体としてアニソールを加えて、固形分濃度を75%に調整した後に自転公転ミキサー(THINKY社製、あわとり練太郎ARV-310)で10分間混合して全固体二次電池正極用スラリーを調製した。
固体電解質としてLi2SとP2S5からなる硫化物ガラス(Li2S/P2S5=75mol%/25mol%、平均粒子径5μm)100質量部と、上記で調製したバインダー組成物を固形分相当で2質量部とを混合し、さらに液状媒体としてアニソールを加えて、固形分濃度を55%に調整した後に自転公転ミキサー(THINKY社製、あわとり練太郎ARV-310)で10分間混合して全固体二次電池固体電解質層用スラリーを調製した。
負極活物質としての人造黒鉛(平均粒子径:20μm)65質量部、固体電解質としてLi2SとP2S5からなる硫化物ガラス(Li2S/P2S5=75mol%/25mol%、平均粒子径5μm)35質量部、上記で調製したバインダー組成物を固形分相当で2質量部とを混合し、さらに液状媒体としてアニソールを加えて、固形分濃度を65%に調整した後に自転公転ミキサー(THINKY社製、あわとり練太郎ARV-310)で10分間混合して全固体二次電池負極用スラリーを調製した。
上記で得られた全固体二次電池固体電解質層用スラリーを調製後5分以内に50rpmのB型粘度計(東機産業株式会社製)により25℃にて粘度測定を行い、その粘度をη0とした。この全固体二次電池固体電解質層用スラリーを25℃恒温槽で48時間保管し、保管後50rpmのB型粘度計で粘度η1を算出した。この測定温度も25℃とした。粘度変化率Δη(%)=(η1/η0)×100を算出し、下記基準により評価した。粘度変化率Δηが小さいものほどスラリー安定性に優れる。
(評価基準)
AA:Δηが80%以上120%未満。
A :Δηが70%以上80%未満または120%以上130%未満。
B :Δηが60%以上70%未満または130%以上140%未満。
C :Δηが60%未満または140%以上。
上記で調製した全固体二次電池正極用スラリーをドクターブレード法によりアルミニウム箔上に塗布し、120℃の減圧下でアニソールを蒸発させて3時間かけて乾燥することにより、厚み0.1mmの正極活物質層が形成された全固体二次電池正極を作製した。
上記で調製した全固体二次電池固体電解質用スラリーをドクターブレード法により離型PETフィルム上に塗布し、120℃の減圧下でアニソールを蒸発させて3時間かけて乾燥することにより、厚み0.1mmの固体電解質層を作製した。
上記で調製した全固体二次電池負極用スラリーをドクターブレード法によりステンレス箔上に塗布し、120℃の減圧下でアニソールを蒸発させて3時間かけて乾燥することにより、厚み0.1mmの負極活物質層が形成された全固体二次電池負極を作製した。
上記で得られた全固体二次電池正極のアルミニウム箔上に形成された正極活物質層について、正極活物質層上に幅20mmのテープを貼り、これを剥離角度90°、剥離速度50mm/minの条件で剥離するときの剥離強度を測定した。評価基準は下記の通りである。結果を表1に示す。
(評価基準)
AA:剥離強度が20N/m以上。
A :剥離強度が10N/m以上20N/m未満。
B :剥離強度が5N/m以上10N/m未満。
C :剥離強度が5N/m未満。
正極試験片のアルミニウム箔側を直径1.0mmの金属棒に沿わせ、この金属棒に巻き付けて正極活物質層が割れるか否か、巻き付け端部に損傷があるか否かを評価した。評価基準は下記の通りである。結果を表1に示す。正極活物質層の損傷が見られないものは、試験片の柔軟性が高く、全固体二次電池組み立てのプロセス適性が良好であることを示す。
(評価基準)
A:正極活物質層の割れなし、巻き付け端部の損傷なし。
B:正極活物質層の割れなし、巻き付け端部の損傷あり。
C:正極活物質層の割れあり。
PETフィルムから剥がした固体電解質層を2枚のステンレス鋼製の平板からなるセルで挟み、インピーダンスアナライザーを使用して測定し、ナイキストプロットからリチウムイオン伝導度を算出した。評価基準は下記の通りである。結果を表1に示す。リチウムイオン伝導度が大きい程、電池性能が良好な全固体二次電池が得られることを示す。
(評価基準)
AA:リチウムイオン伝導度が0.8×10-4S/cm以上1.0×10-4S/cm以下。
A:リチウムイオン伝導度が0.5×10-4S/cm以上0.8×10-4S/cm未満。
B:リチウムイオン伝導度が0.2×10-4S/cm以上0.5×10-4S/cm未満。
C:リチウムイオン伝導度が0.2×10-4S/cm未満。
上記で作成した全固体二次電池正極を直径13mmの円板状に切り出し、全固体二次電池負極とPETフィルムから剥がした固体電解質層を直径15mmの円板状に切り出した。次に、全固体二次電池正極の正極活物質層の面が固体電解質層と接するように、切り出した全固体二次電池正極を切り出した固体電解質層の一方の面に貼り合わせた。全固体二次電池負極の負極活物質層の面が固体電解質層と接するように、切り出した全固体二次電池負極を切り出した固体電解質層のもう一方の面に貼り合わせ、ヒートプレス機を用いて、加熱(120℃)しながら加圧し(600MPa、1分)、アルミニウム箔/正極活物質層/固体電解質層/負極活物質層/ステンレス箔の積層構造を有する全固体二次電池用積層体を作成した。次いで、このようにして作成した全固体二次電池用積層体をスペーサーとワッシャーを組み込んだステンレス製の2032型コインケースに入れ、2032型コインケースをかしめることで、全固体二次電池を作成した。
上記で作成した全固体二次電池を用い、30℃の環境下、充放電試験を実施した。充放電は、4.2V~3.0Vの電位範囲で、0.1Cレートで測定を行った。この0.1Cレートの充放電を繰り返し行い、1サイクル目の放電容量をA(mAh/g)、20サイクル目の放電容量をB(mAh/g)としたとき、20サイクル後の容量維持率を下記式によって算出した。評価基準は以下の通りである。結果を表1に示す。
20サイクル後の容量維持率(%)=(B/A)×100
なお、CレートのCとは時間率であり、(1/X)C=定格容量(Ah)/X(h)と定義される。Xは定格容量分の電気を充電又は放電する際の時間を表す。例えば、0.1Cとは、電流値が定格容量(Ah)/10(h)であることを意味する。
(評価基準)
AA:容量維持率が95%以上100%以下。
A :容量維持率が90%以上95%未満。
B :容量維持率が85%以上90%未満。
C :容量維持率が85%未満。
上記で作成した全固体二次電池を用い、30℃の環境下、4.2V~3.0Vの電位範囲で、0.1Cレートで充放電を20サイクル繰り返した。その後、0℃の環境下、0.1Cレートで4.2Vまで充電した後、30℃の環境下、0.1Cレートで3.0Vまで放電する充放電を行い、異常発生の有無について、下記基準により評価した。結果を表1に示す。なお、「異常」とは、充電時または放電時に電池電圧が0.1V以上低下したことを意味する。
(評価基準)
AA:10個の全固体二次電池のうち、9~10個が異常なく充放電を行った。
A :10個の全固体二次電池のうち、7~8個が異常なく充放電を行った。
B :10個の全固体二次電池のうち、4~6個が異常なく充放電を行った。
C :10個の全固体二次電池のうち、0~3個が異常なく充放電を行った。
表1に示す重合体を用いた以外は、上記実施例1と同様にして全固体二次電池用バインダー組成物を得て、全固体二次電池用スラリー、全固体二次電池電極及び全固体二次電池を作製し、上記実施例1と同様に評価した。それぞれの結果を表1に示す。
下表1に、実施例1~10及び比較例1~6で使用した重合体組成、各物性及び各評価結果をまとめた。
<重合開始剤>
・ピペラジン誘導体a:N-トリメチルシリルピペラジン
・ピペラジン誘導体b:N’-[2-N,N-ビス(トリメチルシリル)アミノエチル]ピペラジン
<変性剤>
・BTADS:N,N-ビス(トリメチルシリル)アミノプロピルメチルジエトキシシラン
・TMADS:N-トリメチルシリル-N-メチルアミノプロピルメチルジエトキシシラン
・DATMS:[3-(N,N-ジメチルアミノ)プロピル]トリメトキシシラン
<老化防止剤>
・BHT:2,6-ジ-tert-ブチル-p-クレゾール
・MBMTBP:2,2’-メチレンビス(4-メチル-6-tert-ブチルフェノール)
・スミライザーGM:2-tert-ブチル-6-(3-tert-ブチル-2-ヒドロキシ-5-メチルベンジル)-4-メチルフェニル=アクリレート
・スミライザーGS:2-[1-(2-ヒドロキシ-3,5-ジ-tert-ペンチルフェニル)エチル]-4,6-ジ-tert-ペンチルフェニル=アクリレート
・IPPD:N-イソプロピル-N’-フェニルベンゼン-1,4-ジアミン
・TMDQ:2,2,4-トリメチル-1,2-ジヒドロキノリン重合体
・ETMDQ:6-エトキシ-2,2,4-トリメチル-1,2-ジヒドロキノリン
<液状媒体(C)>
・DIBK:ジイソブチルケトン
・THF:テトラヒドロフラン
Claims (13)
- 芳香族ビニル化合物に基づく芳香族ビニル単位と、共役ジエン化合物に基づく共役ジエン単位と、を有する重合体(A)と、
老化防止剤(B)を全固体二次電池用バインダー組成物の全質量に対して200ppm以上5,000ppm以下と、
液状媒体(C)と、
を含有する、全固体二次電池用バインダー組成物。 - 前記老化防止剤(B)が、フェノール系老化防止剤及びアミン系老化防止剤よりなる群から選ばれる少なくとも1種を含む、請求項1に記載の全固体二次電池用バインダー組成物。
- 前記重合体(A)の結合スチレン含量が5~40%である、請求項1ないし請求項3のいずれか一項に記載の全固体二次電池用バインダー組成物。
- 前記重合体(A)が、窒素原子、酸素原子、ケイ素原子、ゲルマニウム原子及びスズ原子よりなる群から選ばれる少なくとも1種の原子を含む変性剤に基づく単位を有する、請求項1ないし請求項4のいずれか一項に記載の全固体二次電池用バインダー組成物。
- 前記液状媒体(C)が、脂肪族炭化水素、脂環式炭化水素、芳香族炭化水素、ケトン類、エステル類及びエーテル類よりなる群から選ばれる少なくとも1種である、請求項1ないし請求項5のいずれか一項に記載の全固体二次電池用バインダー組成物。
- 前記重合体(A)が前記液状媒体(C)に溶解してなる、請求項1ないし請求項6のいずれか一項に記載の全固体二次電池用バインダー組成物。
- 請求項1ないし請求項7のいずれか一項に記載の全固体二次電池用バインダー組成物と、固体電解質とを含有する、全固体二次電池用スラリー。
- 前記固体電解質として、硫化物系固体電解質又は酸化物系固体電解質を含有する、請求項8に記載の全固体二次電池用スラリー。
- 正極活物質層と、固体電解質層と、負極活物質層とを少なくとも備える全固体二次電池において、
前記正極活物質層、前記固体電解質層、及び前記負極活物質層の少なくともいずれか1層が、請求項8又は請求項9に記載の全固体二次電池用スラリーを塗布及び乾燥させて形成された層である、全固体二次電池。 - 基材上に、請求項8又は請求項9に記載の全固体二次電池用スラリーを塗布及び乾燥させて形成された層を有する、全固体二次電池用固体電解質シート。
- 請求項8又は請求項9に記載の全固体二次電池用スラリーを基材上に塗布及び乾燥させる工程を含む、全固体二次電池用固体電解質シートの製造方法。
- 請求項12に記載の全固体二次電池用固体電解質シートの製造方法を介して全固体二次電池を製造する、全固体二次電池の製造方法。
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CN114976225A (zh) * | 2022-07-29 | 2022-08-30 | 江苏蓝固新能源科技有限公司 | 一种混合导电浆料、其制备方法及应用 |
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WO2022138896A1 (ja) * | 2020-12-25 | 2022-06-30 | 旭化成株式会社 | 共役ジエン系重合体を用いた全固体電池バインダーおよびそのバインダーを用いた正極層、負極層、電解質層、およびこれらを含む全固体電池 |
CN114181487A (zh) * | 2021-12-25 | 2022-03-15 | 温州市瓯海金龙鞋业有限公司 | 一种抗老化鞋及其生产工艺 |
WO2023249014A1 (ja) * | 2022-06-23 | 2023-12-28 | 富士フイルム株式会社 | 二次電池用バインダー組成物、二次電池用固体電解質含有組成物、全固体二次電池用シート及び全固体二次電池 |
CN114976225A (zh) * | 2022-07-29 | 2022-08-30 | 江苏蓝固新能源科技有限公司 | 一种混合导电浆料、其制备方法及应用 |
CN114976225B (zh) * | 2022-07-29 | 2022-10-14 | 江苏蓝固新能源科技有限公司 | 一种混合导电浆料、其制备方法及应用 |
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KR20220155590A (ko) | 2022-11-23 |
JPWO2021187273A1 (ja) | 2021-09-23 |
CN115362578A (zh) | 2022-11-18 |
US20230178737A1 (en) | 2023-06-08 |
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