WO2018155714A1 - エネルギーデバイス電極用複合樹脂、エネルギーデバイス電極形成用組成物、エネルギーデバイス用正極及びエネルギーデバイス - Google Patents
エネルギーデバイス電極用複合樹脂、エネルギーデバイス電極形成用組成物、エネルギーデバイス用正極及びエネルギーデバイス Download PDFInfo
- Publication number
- WO2018155714A1 WO2018155714A1 PCT/JP2018/007323 JP2018007323W WO2018155714A1 WO 2018155714 A1 WO2018155714 A1 WO 2018155714A1 JP 2018007323 W JP2018007323 W JP 2018007323W WO 2018155714 A1 WO2018155714 A1 WO 2018155714A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- energy device
- positive electrode
- resin
- structural unit
- unit derived
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/621—Binders
- H01M4/622—Binders being polymers
-
- 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
- C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
- C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
- C08F220/42—Nitriles
- C08F220/44—Acrylonitrile
- C08F220/46—Acrylonitrile with carboxylic acids, sulfonic acids or salts thereof
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L27/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers
- C08L27/02—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers not modified by chemical after-treatment
- C08L27/12—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
- C08L27/16—Homopolymers or copolymers or vinylidene fluoride
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L35/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a carboxyl radical, and containing at least one other carboxyl radical in the molecule, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
- C08L35/04—Homopolymers or copolymers of nitriles
-
- 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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/139—Processes of manufacture
- H01M4/1391—Processes of manufacture of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
- H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
-
- 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
- H01M4/621—Binders
- H01M4/622—Binders being polymers
- H01M4/623—Binders being polymers fluorinated polymers
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2203/00—Applications
- C08L2203/20—Applications use in electrical or conductive gadgets
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/028—Positive electrodes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Definitions
- the present invention relates to a composite resin for energy device electrodes, a composition for forming energy device electrodes, a positive electrode for energy devices, and an energy device.
- Lithium ion secondary batteries which are non-aqueous electrolyte type energy devices having a high energy density, are widely used as power sources for portable information terminals such as notebook computers, mobile phones, and PDAs (Personal Digital Assistants).
- a carbon material having a multilayer structure capable of inserting lithium ions between layers (forming a lithium intercalation compound) and releasing is mainly used as the negative electrode active material.
- lithium-containing metal composite oxide is mainly used as the positive electrode active material.
- the electrode of the lithium ion secondary battery is prepared by kneading these active materials, binder resin, solvent (N-methyl-2-pyrrolidone, water, etc.), etc., and then collecting this with a transfer roll or the like. It is applied to one or both sides of a metal foil, which is a body, and after removing the solvent by drying to form a mixture layer, it is produced by compression molding with a roll press or the like.
- lithium-containing metal composite oxide examples include lithium cobaltate (LiCoO 2 ), lithium manganate (LiMn 2 O 4 ), nickel manganese lithium cobaltate (LiNi 1/3 Mn 1/3 Co 1/3 O 2 ), phosphorus such as lithium iron (LiFePO 4) and is frequently used, alone one according to the purpose, or used in combination of two or more.
- PVDF polyvinylidene fluoride
- the alkali metal hydroxide such as LiOH used when producing the lithium-containing metal composite oxide
- PVDF which is frequently used as a binder resin
- the positive electrode for energy devices of a nonaqueous electrolyte system is produced by applying a positive electrode slurry containing a lithium-containing metal composite oxide and PVDF on a current collector.
- the positive electrode slurry becomes basic.
- a method for producing a positive electrode active material capable of preventing gelation of the positive electrode slurry a method for producing a positive electrode active material comprising a specific layered compound, in which the synthesized positive electrode active material powder is stirred and mixed in pure water. Thereafter, when the pH of a supernatant obtained by standing is measured, only a positive electrode active material having a pH within a specific range is selected, and a method for producing a positive electrode active material is disclosed (for example, see Patent Document 2.)
- JP 2008-235147 A Japanese Patent No. 4951823
- Patent Document 2 may cause a decrease in capacity density or a decrease in cycle characteristics.
- the present invention has been made in view of the above circumstances, and a composite resin for an energy device electrode in which gelation of slurry and sedimentation of the slurry are suppressed, a composition for forming an energy device electrode using the same, and a positive electrode for energy device And an energy device.
- One embodiment of the present invention relates to the following, for example.
- a composite resin for energy device electrodes containing a resin containing a structural unit derived from a nitrile group-containing monomer and a fluororesin.
- ⁇ 2> Used for forming a positive electrode mixture layer containing a positive electrode active material containing a lithium-containing metal composite oxide having lithium and nickel, and the proportion of nickel in the metal excluding lithium being 50 mol% or more
- Composite resin for energy device electrodes ⁇ 3> The composite resin for energy device electrodes according to ⁇ 2>, wherein the lithium-containing metal composite oxide contains a compound represented by the following formula (I).
- M is at least one selected from the group consisting of Al, Mn, Mg, and Ca, and a, b, c, d, and e are 0.2 ⁇ a ⁇ 1,.
- the resin including a structural unit derived from a nitrile group-containing monomer further includes a structural unit derived from a monomer represented by the following formula (II): Any one of ⁇ 1> to ⁇ 3> The composite resin for energy device electrodes described in 1.
- R 1 represents a hydrogen atom or a methyl group
- R 2 represents a hydrogen atom or a monovalent hydrocarbon group
- n represents an integer of 1 to 50.
- the resin including a structural unit derived from a nitrile group-containing monomer further includes a structural unit derived from a monomer represented by the following formula (III): Any one of ⁇ 1> to ⁇ 5>
- R 3 represents a hydrogen atom or a methyl group
- R 4 represents an alkyl group having 4 to 30 carbon atoms.
- ⁇ 7> The structure derived from the monomer represented by the formula (III) with respect to 1 mol of the structural unit derived from the nitrile group-containing monomer contained in the resin containing the structural unit derived from the nitrile group-containing monomer.
- ⁇ 8> The composite resin for energy device electrodes according to any one of ⁇ 1> to ⁇ 7>, wherein the nitrile group-containing monomer includes acrylonitrile.
- ⁇ 9> The composite resin for energy device electrodes according to any one of ⁇ 1> to ⁇ 8>, wherein the fluororesin includes polyvinylidene fluoride (PVDF).
- PVDF polyvinylidene fluoride
- a positive electrode active material comprising a lithium-containing metal composite oxide having lithium and nickel, wherein the proportion of nickel in the metal excluding lithium is 50 mol% or more, and any one of ⁇ 1> to ⁇ 9>
- a composition for forming an energy device electrode comprising the composite resin for an energy device electrode according to Item.
- ⁇ 14> The energy device according to ⁇ 13>, wherein the energy device is a lithium ion secondary battery.
- a composite resin for an energy device electrode in which gelation of slurry and sedimentation of the slurry are suppressed, an energy device electrode forming composition using the same, a positive electrode for energy device, and an energy device.
- the term “process” includes a process that is independent of other processes and includes the process if the purpose of the process is achieved even if it cannot be clearly distinguished from the other processes. It is.
- numerical values indicated by using “to” include numerical values described before and after “to” as the minimum value and the maximum value, respectively.
- the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of another numerical range. Good. Further, in the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range may be replaced with the values shown in the examples.
- the content of each component in the composition is the sum of the plurality of substances present in the composition unless there is a specific indication when there are a plurality of substances corresponding to each component in the composition. It means the content rate of.
- the particle diameter of each component in the composition is a mixture of the plurality of types of particles present in the composition unless there is a specific indication when there are a plurality of types of particles corresponding to each component in the composition. Means the value of.
- the term “layer” or “film” refers to a part of the region in addition to the case where the layer or the film is formed when the region where the layer or film exists is observed. It is also included when it is formed only.
- (meth) acryl means at least one of acryl and methacryl
- (meth) acrylate means at least one of acrylate and methacrylate
- the “binder resin” refers to a resin having a function of binding particles such as an active material.
- the composite resin for energy device electrodes of the present disclosure contains a resin containing a structural unit derived from a nitrile group-containing monomer and a fluororesin.
- the composite resin for energy device electrodes of the present disclosure includes lithium and nickel, and a lithium-containing metal composite oxide (hereinafter referred to as a specific metal oxide) in which the proportion of nickel in the metal excluding lithium is 50 mol% or more. May be used for forming a positive electrode mixture layer containing a positive electrode active material.
- the composite resin for energy device electrodes of the present disclosure When the composite resin for energy device electrodes of the present disclosure is used for forming the positive electrode mixture layer, gelation of the slurry and sedimentation of the slurry are suppressed.
- the composite resin for energy device electrodes of the present disclosure is particularly useful when used for forming a positive electrode mixture layer containing a positive electrode active material containing a specific metal oxide.
- slurry sedimentation means that the positive electrode active material settles in a slurry in which a positive electrode active material, a conductive material, a binder resin, etc. are mixed in a solvent such as N-methyl-2-pyrrolidone (NMP). It refers to the phenomenon.
- NMP N-methyl-2-pyrrolidone
- a fluororesin such as PVDF tends to be altered by the elimination reaction of HF when it comes into contact with a basic substance such as LiOH. Therefore, when forming a mixture layer using fluororesins, such as PVDF, the slurry containing fluororesins, such as PVDF, tends to gel. In particular, when a positive electrode active material containing a specific metal oxide is used, the slurry is easily gelled.
- a nitrile group in a resin containing a structural unit derived from a nitrile group-containing monomer is less likely to undergo a elimination reaction when contacting with a basic substance as compared with a fluorine atom. Therefore, a resin containing a structural unit derived from a nitrile group-containing monomer tends to be harder to change when it comes into contact with a basic substance than a fluororesin.
- a resin containing a structural unit derived from a nitrile group-containing monomer tends to be adsorbed on the particulate conductive material and tends to disperse the particulate conductive material excessively in the slurry.
- the particulate conductive material is in an excessively dispersed state, it is difficult to form a higher order structure of the conductive material, and it is difficult to hold the positive electrode active material in the higher order structure of the conductive material. Therefore, when forming a mixture layer using a resin containing a structural unit derived from a nitrile group-containing monomer, a slurry using a resin containing a structural unit derived from a nitrile group-containing monomer tends to settle.
- the slurry tends to settle when the content of the conductive material in the mixture layer is 1.5% by mass or less.
- a fluororesin such as PVDF does not easily disperse the particulate conductive material because fluorine atoms are contained in the fluororesin, and easily forms a higher order structure of the conductive material. Therefore, the positive electrode active material is easily held in the higher-order structure of the conductive material, and the slurry tends not to settle.
- the composite resin for energy device electrodes of the present disclosure contains a resin containing a structural unit derived from a nitrile group-containing monomer and a fluororesin
- a gel of a slurry having a resin containing a structural unit derived from a nitrile group-containing monomer It is presumed that the effect of suppressing the crystallization and the effect of suppressing the sedimentation of the slurry of the fluororesin are exhibited, and the gelation of the slurry and the sedimentation of the slurry are suppressed.
- the slurry is difficult to gel.
- the content of the conductive material in the mixture layer is a slurry having a content of 1.5% by mass or less, the slurry is unlikely to settle.
- the fluororesin refers to a resin including a structural unit in which some or all of the hydrogen atoms in the polyethylene skeleton are substituted with fluorine atoms in the main chain.
- the resin including a structural unit derived from a nitrile group-containing monomer includes a structural unit derived from a nitrile group-containing monomer in the main chain, and a part or all of the hydrogen atoms in the polyethylene skeleton are fluorine.
- the composite resin for energy device electrodes of the present disclosure contains a resin containing a structural unit derived from a nitrile group-containing monomer.
- nitrile group-containing monomer- There is no restriction
- nitrile group-containing monomers include acrylic nitrile group-containing monomers such as acrylonitrile and methacrylonitrile, cyan nitrile group-containing monomers such as ⁇ -cyanoacrylate and dicyanovinylidene, and fumarate nitrile groups such as fumaronitrile. Containing monomers and the like.
- acrylonitrile is preferable in terms of ease of polymerization, cost performance, electrode flexibility, flexibility, oxidation resistance, resistance to swelling with respect to an electrolytic solution, and the like.
- the ratio of acrylonitrile in the nitrile group-containing monomer is, for example, preferably 5% by mass to 100% by mass, more preferably 50% by mass to 100% by mass, and 70% by mass to 100% by mass. More preferably it is.
- One of these nitrile group-containing monomers may be used alone, or two or more thereof may be used in combination.
- the content of acrylonitrile is preferably, for example, 5% by mass to 95% by mass with respect to the total amount of the nitrile group-containing monomer. 50 mass% to 95 mass% is more preferable.
- the resin including a structural unit derived from a nitrile group-containing monomer used in the present disclosure preferably further includes a structural unit derived from a monomer represented by the formula (II) from the viewpoint of flexibility of the electrode.
- R 1 represents a hydrogen atom or a methyl group.
- n represents an integer of 1 to 50.
- n is preferably an integer of 2 to 30, more preferably an integer of 2 to 15, and further preferably an integer of 2 to 10.
- n is preferably an integer of 1 to 30, more preferably an integer of 1 to 15, and further preferably an integer of 1 to 10.
- R 2 represents a hydrogen atom or a monovalent hydrocarbon group, for example, monovalent hydrocarbon preferably a monovalent hydrocarbon group with a carbon number 1 to 30, carbon atoms is 1 to 25 A hydrogen group is more preferable, and a monovalent hydrocarbon group having 1 to 12 carbon atoms is more preferable.
- the carbon number of the monovalent hydrocarbon group does not include the carbon number contained in the substituent.
- R 2 is a hydrogen atom or a monovalent hydrocarbon group having 1 to 30 carbon atoms, sufficient swelling resistance to the electrolytic solution tends to be obtained.
- examples of the monovalent hydrocarbon group include an alkyl group and a phenyl group.
- R 2 is preferably an alkyl group having 1 to 12 carbon atoms or a phenyl group.
- the alkyl group may be linear, branched or cyclic. In the alkyl group and phenyl group represented by R 2 , a part of hydrogen atoms may be substituted with a substituent.
- the substituent of R 2 is an alkyl group, a fluorine atom, a chlorine atom, a bromine atom, a halogen atom, a substituent containing a nitrogen atom such as an iodine atom, a substituent containing a phosphorus atom and an aromatic ring .
- substituent when R 2 is a phenyl group include a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, a substituent containing a nitrogen atom, a substituent containing a phosphorus atom, an aromatic ring, and a carbon number. Examples thereof include 3 to 10 linear, branched or cyclic alkyl groups.
- a monomer represented by the formula (II) a commercially available product or a synthetic product may be used. Specific examples of commercially available monomers represented by the formula (II) include 2-methoxyethyl acrylate, ethoxydiethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: Light acrylate EC-).
- methoxytriethylene glycol acrylate (R 1 in the general formula (II) is H, R 2 is CH 3 , in terms of reactivity when copolymerized with a nitrile group-containing monomer such as acrylonitrile. n is more preferably 3).
- R 1 in the general formula (II) is H
- R 2 is CH 3
- n is more preferably 3
- One of these monomers represented by the formula (II) may be used alone, or two or more thereof may be used in combination.
- the resin including a structural unit derived from a nitrile group-containing monomer used in the present disclosure preferably further includes a structural unit derived from a monomer represented by the formula (III) from the viewpoint of flexibility of the electrode.
- R 3 represents a hydrogen atom or a methyl group.
- R 4 has a carbon number represents an alkyl group having 4 to 30, preferably an alkyl group having 5-25 carbon atoms, more preferably an alkyl group having a carbon number of 6 to 20, more preferably carbon number Is an alkyl group of 8 to 16. If the alkyl group represented by R 4 has 4 or more carbon atoms, sufficient flexibility tends to be obtained. If the number of carbon atoms of the alkyl group represented by R 4 is 30 or less, sufficient swelling resistance to the electrolytic solution tends to be obtained. Note that when the alkyl group represented by R 4 has a substituent, the carbon number of the alkyl group does not include the carbon number included in the substituent.
- the alkyl group represented by R 4 may be linear, branched or cyclic. In the alkyl group represented by R 4 , some hydrogen atoms may be substituted with a substituent.
- substituents include a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, a substituent containing a nitrogen atom, a substituent containing a phosphorus atom, an aromatic ring, and a cycloalkyl group having 3 to 10 carbon atoms. Can be mentioned.
- alkyl group represented by R 4 examples include linear, branched or cyclic alkyl groups, and halogenated alkyl groups such as fluoroalkyl groups, chloroalkyl groups, bromoalkyl groups, and alkyl iodide groups. It is done.
- a commercially available product or a synthetic product may be used.
- Specific examples of commercially available monomers represented by formula (III) include n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, and amyl (meth) ) Acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) ) Acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, hexadecyl (meth) acrylate, stearyl (meth) acryl
- R 4 is a fluoroalkyl group, 1,1-bis (trifluoromethyl) -2,2,2-trifluoroethyl acrylate, 2,2,3,3,4,4,4-heptafluoro Butyl acrylate, 2,2,3,4,4,4-hexafluorobutyl acrylate, nonafluoroisobutyl acrylate, 2,2,3,3,4,4,5,5-octafluoropentyl acrylate, 2,2 , 3,3,4,4,5,5,5-nonafluoropentyl acrylate, 2,2,3,3,4,4,5,5,6,6,6-undecafluorohexyl acrylate, 2, 2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluorooctyl acrylate, 3,3,4,4,5,5,6,6 7, 7, 8, 8, 9, 9, 10, 10, 10-heptadecafluorodecyl acrylate, 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9
- the resin including a structural unit derived from a nitrile group-containing monomer used in the present disclosure is derived from a carboxy group-containing monomer and includes a carboxy group from the viewpoint of adhesion between the current collector and the mixture layer. Units may be included.
- the carboxy group-containing monomer is not particularly limited, and includes acrylic carboxy group-containing monomers such as acrylic acid and methacrylic acid, croton carboxy group-containing monomers such as crotonic acid, maleic acid, and anhydrides thereof.
- Maleic carboxy group-containing monomers such as itaconic acid and its anhydride, and citraconic carboxy group-containing monomers such as citraconic acid and its anhydride.
- acrylic acid is preferable in terms of ease of polymerization, cost performance, electrode flexibility, flexibility, and the like.
- a carboxy group containing monomer may be used individually by 1 type, and may be used in combination of 2 or more type.
- the acrylic acid content is determined as follows: For example, the content is preferably 5% by mass to 95% by mass, and more preferably 50% by mass to 95% by mass with respect to the total amount.
- the resin containing a structural unit derived from a nitrile group-containing monomer used in the present disclosure is derived from a structural unit derived from a nitrile group-containing monomer, or a monomer represented by the formula (II) included as necessary.
- Structural units, structural units derived from the monomer represented by formula (III), and structural units derived from a carboxy group-containing monomer and containing a carboxy group, as well as other single quantities different from these monomers The structural units derived from the body can be appropriately combined.
- monomers are not particularly limited, and short chain (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, vinyl chloride, bromide Vinyl halides such as vinyl and vinylidene chloride, maleic acid imide, phenylmaleimide, (meth) acrylamide, styrene, ⁇ -methylstyrene, vinyl acetate, sodium (meth) allylsulfonate, sodium (meth) allyloxybenzenesulfonate , Sodium styrenesulfonate, 2-acrylamido-2-methylpropanesulfonic acid and its salts.
- These other monomers may be used individually by 1 type, and may be used in combination of 2 or more type.
- the resin containing a structural unit derived from a nitrile group-containing monomer used in the present disclosure is a structural unit derived from a monomer represented by formula (II), or a structure derived from a monomer represented by formula (III)
- the ratio to 1 mol of the structural unit derived from the nitrile group-containing monomer is as follows: A molar ratio is preferred.
- the resin containing a structural unit derived from a nitrile group-containing monomer used in the present disclosure contains a structural unit derived from a monomer represented by the formula (II), 1 mol of the structural unit derived from a nitrile group-containing monomer
- the ratio of the structural unit derived from the monomer represented by the formula (II) with respect to is preferably 0.001 mol to 0.2 mol, and more preferably 0.003 mol to 0.05 mol. More preferably, the amount is 0.005 mol to 0.02 mol.
- the positive electrode current collector When the ratio of the structural unit derived from the monomer represented by the formula (II) to 1 mol of the structural unit derived from the nitrile group-containing monomer is in the range of 0.001 mol to 0.2 mol, the positive electrode current collector In particular, the flexibility and flexibility of the electrode tend to be improved without impairing the adhesion to the positive electrode current collector using an aluminum foil and the swelling resistance against the electrolyte.
- the resin containing a structural unit derived from a nitrile group-containing monomer used in the present disclosure contains a structural unit derived from a monomer represented by the formula (III), 1 mol of the structural unit derived from a nitrile group-containing monomer
- the ratio of the structural unit derived from the monomer represented by the formula (III) to is preferably 0.001 mol to 0.2 mol, more preferably 0.003 mol to 0.05 mol. More preferably, the amount is 0.005 mol to 0.02 mol.
- the positive electrode current collector When the ratio of the structural unit derived from the monomer represented by the formula (III) to 1 molar structural unit derived from the nitrile group-containing monomer is in the range of 0.001 mol to 0.2 mol, the positive electrode current collector There is a tendency that the flexibility and flexibility of the electrode are improved without impairing the adhesion with the positive electrode current collector using an aluminum foil, particularly the swelling resistance against the electrolytic solution.
- the resin containing a structural unit derived from a nitrile group-containing monomer used in the present disclosure is derived from a carboxy group-containing monomer and contains a structural unit containing a carboxy group
- the structural unit 1 derived from a nitrile group-containing monomer
- the ratio of the structural unit derived from the carboxy group-containing monomer to the mole and containing the carboxy group is preferably 0.01 mol to 0.2 mol, and preferably 0.02 mol to 0.1 mol. More preferably, it is 0.03 mol to 0.06 mol.
- the ratio of the structural unit derived from the carboxy group-containing monomer and containing the carboxy group to 1 mol of the structural unit derived from the nitrile group-containing monomer is in the range of 0.01 mol to 0.2 mol, the flexibility of the electrode Therefore, it tends to be excellent in adhesion to a positive electrode current collector, in particular, a positive electrode current collector using an aluminum foil, and swelling resistance to an electrolytic solution without impairing the properties and flexibility.
- the ratio of the structural unit derived from the carboxy group-containing monomer and containing the carboxy group to 1 mol of the structural unit derived from the nitrile group-containing monomer May be less than 0.01 mol, 0.005 mol or less, or 0 mol.
- the resin containing a structural unit derived from a nitrile group-containing monomer used in the present disclosure contains a structural unit derived from another monomer, the other monomer with respect to 1 mol of the structural unit derived from the nitrile group-containing monomer
- the ratio of the derived structural unit is preferably 0.005 mol to 0.1 mol, more preferably 0.01 mol to 0.06 mol, and 0.03 mol to 0.05 mol. More preferably.
- the content of the structural unit derived from the nitrile group-containing monomer in the resin including the structural unit derived from the nitrile group-containing monomer used in the present disclosure is the same as that of the resin including the structural unit derived from the nitrile group-containing monomer. Based on the total amount, it is preferably 80 mol% or more, and more preferably 90 mol% or more.
- the resin containing a structural unit derived from a nitrile group-containing monomer used in the present disclosure is a structural unit derived from a cross-linking component for complementing the swelling resistance to the electrolyte solution, to complement the flexibility and flexibility of the electrode.
- the structural unit derived from the rubber component may be included.
- Examples of the polymerization mode for synthesizing a resin containing a structural unit derived from a nitrile group-containing monomer used in the present disclosure include precipitation polymerization, bulk polymerization, suspension polymerization, emulsion polymerization, solution polymerization, and the like. There is no. Precipitation polymerization in water is preferred in terms of ease of synthesis, ease of post-treatment such as recovery and purification. Hereinafter, the precipitation polymerization in water will be described in detail.
- Water-soluble polymerization initiator As the polymerization initiator for carrying out precipitation polymerization in water, a water-soluble polymerization initiator is preferable in view of polymerization initiation efficiency and the like.
- Water-soluble polymerization initiators include persulfates such as ammonium persulfate, potassium persulfate and sodium persulfate, water-soluble peroxides such as hydrogen peroxide, 2,2′-azobis (2-methylpropionamidine hydrochloride) A combination of water-soluble azo compounds such as persulfate, etc.
- reducing agents such as sodium bisulfite, ammonium bisulfite, sodium thiosulfate, hydrosulfite and polymerization accelerators such as sulfuric acid, iron sulfate, copper sulfate Redox type (redox type) and the like.
- persulfates water-soluble azo compounds, and the like are preferable in terms of ease of resin synthesis.
- ammonium persulfate is particularly preferred.
- acrylonitrile is selected as the nitrile group-containing monomer
- acrylic acid is selected as the carboxy group-containing monomer
- methoxytriethylene glycol acrylate is selected as the monomer represented by the formula (II) to precipitate in water.
- all the three monomers are water-soluble in the state of monomers (also referred to as monomers), so that the water-soluble polymerization initiator acts effectively and the polymerization starts smoothly. Since the polymer precipitates as the polymerization proceeds, the reaction system becomes suspended, and finally a resin containing a structural unit derived from a nitrile group-containing monomer with little unreacted substance is obtained in a high yield. It is done.
- the polymerization initiator should be used, for example, in the range of 0.001 mol% to 5 mol% with respect to the total amount of monomers used for the synthesis of the resin including the structural unit derived from the nitrile group-containing monomer. It is preferable to use in the range of 0.01 mol% to 2 mol%.
- a chain transfer agent when carrying out precipitation polymerization in water, a chain transfer agent can be used for the purpose of adjusting the molecular weight.
- the chain transfer agent include mercaptan compounds, carbon tetrachloride, ⁇ -methylstyrene dimer and the like. Of these, ⁇ -methylstyrene dimer is preferred from the viewpoint of low odor.
- a solvent other than water can be added as necessary for adjusting the particle diameter of the resin to be precipitated.
- solvents other than water include amides such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, N, N-dimethylethyleneurea, N, N-dimethylpropyleneurea, tetra Ureas such as methylurea, lactones such as ⁇ -butyrolactone and ⁇ -caprolactone, carbonates such as propylene carbonate, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-butyl acetate , Esters such as butyl cellosolve acetate, butyl carbitol acetate, ethyl cellosolve
- -Polymerization method- Precipitation polymerization in water includes, for example, a nitrile group-containing monomer and a carboxy group-containing monomer used as necessary, a monomer represented by formula (II), a monomer represented by formula (III) And other monomers are introduced into the solvent, and the polymerization temperature is preferably 0 to 100 ° C., more preferably 30 to 95 ° C., preferably 1 to 50 hours, more preferably 2 to 12 hours. Done by holding time.
- the polymerization temperature is 0 ° C. or higher, the polymerization reaction tends to be accelerated. Further, when the polymerization temperature is 100 ° C. or lower, even when water is used as a solvent, the water tends to evaporate so that it becomes difficult to perform polymerization.
- the weight average molecular weight of the resin containing a structural unit derived from a nitrile group-containing monomer used in the present disclosure is preferably 10,000 to 1,000,000, more preferably 100,000 to 800,000, and preferably 250,000 to 700,000. Further preferred.
- the weight average molecular weight is a value measured by the following method. A measurement object is dissolved in N-methyl-2-pyrrolidone, and a PTFE (polytetrafluoroethylene) filter (manufactured by Kurashiki Boseki Co., Ltd., HPLC (high performance liquid chromatography) pretreatment, chromatodisc, model number: 13N, pore size: 0.45 ⁇ m] to remove insoluble matter.
- PTFE polytetrafluoroethylene
- GPC Pump: L6200 Pump (manufactured by Hitachi, Ltd.), detector: differential refractive index detector L3300 RI Monitor (manufactured by Hitachi, Ltd.), column: TSKgel-G5000HXL and TSKgel-G2000HXL (both in total) (Manufactured by Co., Ltd.) in series, column temperature: 30 ° C., eluent: N-methyl-2-pyrrolidone, flow rate: 1.0 ml / min, standard material: polystyrene], and the weight average molecular weight is measured.
- the acid value of the resin containing a structural unit derived from a nitrile group-containing monomer used in the present disclosure is preferably 0 mgKOH / g to 40 mgKOH / g, more preferably 0 mgKOH / g to 10 mgKOH / g, More preferably, it is 0 mgKOH / g to 5 mgKOH / g.
- the acid value refers to a value measured by the following method. First, after precisely weighing 1 g of a measurement object, 30 g of acetone is added to the measurement object, and the measurement object is dissolved. Next, an appropriate amount of an indicator, phenolphthalein, is added to the solution to be measured and titrated with a 0.1N aqueous KOH solution.
- an indicator phenolphthalein
- A The nonvolatile content of the solution to be measured is calculated from the residue mass by weighing about 1 ml of the solution to be measured in an aluminum pan, drying it on a hot plate heated to 160 ° C. for 15 minutes.
- a nitrile group-containing monomer and a carboxy group-containing monomer used as necessary a monomer represented by formula (II), a monomer represented by formula (III), and other monomers
- a monomer represented by formula (II) a monomer represented by formula (III)
- other monomers When polymerizing, since the polymerization heat of the nitrile group-containing monomer and the carboxy group-containing monomer used as necessary is particularly large, it is preferable to proceed the polymerization while dropping these monomers into the solvent.
- the resin containing a structural unit derived from a nitrile group-containing monomer used in the present disclosure is produced by polymerization as described above, and is usually used in the form of a varnish dissolved in a solvent.
- the solvent used for the preparation of the resin containing a structural unit derived from a varnish-like nitrile group-containing monomer is not particularly limited.
- the solvent and water that can be added when the above-described precipitation polymerization in water is performed. Can be used.
- amides, ureas, lactones, or a mixed solvent containing them is preferable in terms of solubility in a resin including a structural unit derived from a nitrile group-containing monomer used in the present disclosure.
- N-methyl-2-pyrrolidone, ⁇ -butyrolactone or a mixed solvent containing them is more preferable.
- These solvent may be used individually by 1 type, and may be used in combination of 2 or more type.
- the amount of the solvent used is not particularly limited as long as the amount of the resin including the structural unit derived from the nitrile group-containing monomer is not less than a necessary minimum amount capable of maintaining a dissolved state at room temperature (25 ° C.).
- the viscosity of the slurry is usually adjusted while adding a solvent. Therefore, it is preferable that the amount is not excessively diluted.
- the composite resin for energy device electrodes of the present disclosure includes a fluororesin.
- the fluororesin used in the present disclosure is not particularly limited as long as the main chain includes a structural unit in which some or all of the hydrogen atoms in the polyethylene skeleton are substituted with fluorine atoms.
- Fluororesin includes homopolymers such as polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), polychlorotrifluoroethylene (PCTFE), tetrafluoroethylene-perfluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoropropylene copolymer (PFA), tetrafluoroethylene-ethylene copolymer (ETFE), chlorotrifluoroethylene-ethylene copolymer and the like, and carboxy group And the like.
- PVDF is preferable from the viewpoint of solubility in a solvent, swelling property in an electrolytic solution, flexibility of a resin, and the like.
- these fluororesins may be used individually by 1 type, and may be used in combination of 2 or more type.
- the composition of the composite resin for energy device electrodes of the present disclosure is not particularly limited as long as it includes a resin containing a structural unit derived from a nitrile group-containing monomer and a fluororesin.
- a mass-based mixing ratio of a resin containing a structural unit derived from a nitrile group-containing monomer and a fluororesin is 90:10 to Preferably it is 50:50.
- the property of the slurry containing the composite resin for energy device electrodes of the present disclosure is that the more the proportion of the resin containing a structural unit derived from a nitrile group-containing monomer, the more difficult it is to gel. The active material tends to settle.
- the resin containing a structural unit derived from a nitrile group-containing monomer and the fluororesin have different swellability with respect to the electrolytic solution, and as a battery characteristic, there are many resins containing a structural unit derived from a nitrile group-containing monomer. As the number of fluororesins increases, the battery resistance tends to decrease.
- the mass-based mixing ratio of the resin containing the structural unit derived from the nitrile group-containing monomer and the fluororesin is 90:10. More preferably, it is ⁇ 55: 45, more preferably 80:20 to 60:40, and particularly preferably 75:25 to 65:35.
- the mixing ratio of the resin containing the structural unit derived from the nitrile group-containing monomer and the fluororesin based on the mass (resin containing the structural unit derived from the nitrile group-containing monomer: fluororesin) is 10: 90 to 50:50 is preferable, 10:90 to 45:55 is more preferable, 10:90 to 40:60 is further preferable, and 10:90 to 35:65 is preferable. Particularly preferred.
- the composite resin for energy device electrodes of the present disclosure in which the mixing ratio of the resin containing the structural unit derived from the nitrile group-containing monomer and the fluororesin based on the mass is 10:90 to 50:50 When combined with a metal oxide, the generation of gas from the energy device tends to be suppressed.
- composition for energy device electrode formation of this indication contains the positive electrode active material containing a specific metal oxide, and the composite resin for energy device electrodes of this indication. Below, each component contained in the composition for energy device electrode formation of this indication is demonstrated. In addition, the preferable aspect of the composite resin for energy device electrodes of this indication contained in the composition for energy device electrode formation of this indication is as above-mentioned.
- the positive electrode active material contained in the composition for forming an energy device electrode of the present disclosure contains a specific metal oxide.
- the specific metal oxide as the positive electrode active material, for example, the energy density of a lithium ion secondary battery which is an example of an energy device can be improved.
- the slurry containing the energy device electrode forming composition of the present disclosure can be obtained by combining the specific metal oxide and the composite resin for the energy device electrode of the present disclosure. Gelation and slurry settling are suppressed.
- the specific metal oxide preferably contains a compound represented by the following formula (I).
- the ratio (b) of Ni is preferably 0.5 ⁇ b ⁇ 0.9, more preferably 0.55 ⁇ b ⁇ 0.85, and 0.6 ⁇ b ⁇ 0. More preferably, it is .8. Further, the discharge performance of the positive electrode active material is improved as the ratio of Co increases, and the capacity density of the positive electrode active material tends to increase as the ratio of Co decreases, so the ratio (c) of Co is 0. 0.05 ⁇ c ⁇ 0.4 is preferable, and 0.1 ⁇ c ⁇ 0.4 is more preferable.
- At least one element selected from the group consisting of Al, Mn, Mg and Ca can be contained as M in the formula (I).
- the thermodynamic stability of the positive electrode active material tends to be high, and the resistance increase caused by nickel entering the lithium site tends to be suppressed.
- the smaller the M ratio the larger the capacity density of the positive electrode active material. From such a viewpoint, the ratio (d) of M is preferably 0 ⁇ d ⁇ 0.2.
- the compound represented by the formula (I) can be produced by a method commonly used in the field of energy devices. An example of production is shown below.
- a metal salt solution of a metal to be introduced into the positive electrode active material is prepared.
- the metal salt those commonly used in the field of energy devices can be used, and examples thereof include sulfates, chloride salts, nitrates, and acetates.
- nitrate is preferable because it functions as an oxidant in the subsequent firing step, so that the oxidation of the metal in the firing raw material is easily promoted, and since it volatilizes by firing, it is difficult to remain in the positive electrode active material.
- the molar ratio of each metal contained in the metal salt solution is preferably equal to the molar ratio of each metal of the positive electrode active material to be produced.
- the lithium source is suspended in pure water.
- the lithium source those commonly used in the field of energy devices can be used, and lithium carbonate, lithium nitrate, lithium hydroxide, lithium acetate, alkyl lithium, fatty acid lithium, lithium lithium and the like can be mentioned.
- the metal salt solution of the said metal is added and lithium salt solution slurry is produced.
- fine lithium-containing carbonate precipitates in the slurry.
- the average particle diameter of the lithium-containing carbonate in the slurry can be adjusted by the shear rate of the slurry.
- the precipitated lithium-containing carbonate is filtered off and dried to obtain a precursor of the positive electrode active material.
- the obtained lithium-containing carbonate is filled in a firing container and fired in a firing furnace. Firing is preferably held in a heated state for a predetermined time in an oxygen-containing atmosphere, preferably in an oxygen atmosphere. Further, the firing is preferably performed under a pressure of 101 kPa to 202 kPa. The amount of oxygen in the composition can be increased by heating under pressure.
- the firing temperature is preferably 850 ° C. to 1200 ° C., more preferably 850 ° C. to 1100 ° C., and further preferably 850 ° C. to 1000 ° C. When firing in such a temperature range, the crystallinity of the positive electrode active material tends to be improved.
- the specific metal oxide one washed with a washing liquid may be used.
- a washing liquid By cleaning the specific metal oxide with the cleaning liquid, basic substances such as LiOH that may be present in the specific metal oxide are removed.
- the cleaning liquid used for cleaning the specific metal oxide conventionally used cleaning liquids for positive electrode active materials such as pure water, water adjusted to be acidic or alkaline, and organic solvents such as alcohol are used. From the viewpoint of purity and economical viewpoint, pure water is preferable as the cleaning liquid. For example, after sufficiently stirring a predetermined amount of the specific metal oxide and the cleaning liquid, let stand, and then collect the specific metal oxide by solid-liquid separation by a known method such as filtration, decantation, The specific metal oxide can be washed.
- the mixing ratio of the resin containing the structural unit derived from the nitrile group-containing monomer and the fluororesin based on the mass is 10:90 to 50:50. Even if the ratio of the fluororesin is large, the slurry is difficult to gel, and further, the generation of gas from the energy device tends to be suppressed.
- the composition for forming an energy device electrode of the present disclosure can be used in combination with a lithium-containing metal composite oxide other than the specific metal oxide commonly used in the field of energy devices as a positive electrode active material.
- a lithium-containing metal composite oxide other than the specific metal oxide commonly used in the field of energy devices as a positive electrode active material.
- Commonly used lithium-containing metal composite oxides include LiCoO 2 , LiNiO 2 , LiMnO 2 , LiNi 1/3 Mn 1/3 Co 1/3 O 2 , LiMn 2 O 4 and the like.
- the ratio of the specific metal oxide in the positive electrode active material is preferably 70% by mass or more, and 80% by mass. More preferably, it is more preferably 90% by mass or more.
- lithium-containing metal composite oxides can be arbitrarily selected in accordance with characteristics such as capacity, input / output characteristics, cycle life, voltage, and safety of the target energy device.
- a positive electrode active material may be used individually by 1 type, and may be used in combination of 2 or more type.
- the composition for forming an energy device electrode of the present disclosure may include a conductive material from the viewpoint of reducing the resistance of the electrode.
- a conductive material those commonly used in the field of energy devices can be used. Specific examples include carbon black, graphite, carbon fiber, and metal fiber. Examples of carbon black include acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal black. Examples of graphite include natural graphite and artificial graphite.
- a conductive material may be used individually by 1 type, and may be used in combination of 2 or more type.
- the composition for forming an energy device electrode of the present disclosure may contain a solvent.
- a solvent used for a slurry What is necessary is just a solvent which can melt
- a solvent used for preparing a resin solution by dissolving the composite resin for energy device electrodes of the present disclosure is often used as it is, for example, N-methyl-2-pyrrolidone and ⁇ -Butyrolactone is preferred.
- These solvent may be used individually by 1 type, and may be used in combination of 2 or more type.
- the composition for forming an energy device electrode of the present disclosure includes a crosslinking component for complementing swelling resistance to an electrolytic solution, a rubber component for complementing flexibility and flexibility of the electrode, and electrode coating property of the slurry.
- Various additives such as an anti-settling agent, an antifoaming agent, and a leveling agent for improvement can be blended as necessary.
- a thickener can be added to the slurry in order to improve the dispersion stability and coating property of the slurry.
- thickeners include polyacrylic acid and polyacrylic acid derivatives such as alkali metal salts thereof, polyvinyl alcohol copolymers such as ethylene- (meth) acrylic acid copolymer, polyvinyl alcohol, and ethylene-vinyl alcohol copolymer. Examples include coalescence.
- carbon dioxide gas is dissolved in the composition for forming an energy device electrode, and a strong basic substance such as LiOH that may be present in the composition for forming an energy device electrode is neutralized to obtain Li 2 CO 3 or the like. It may be changed to a weakly basic substance. By performing the neutralization treatment, the generation of gas from the energy device tends to be suppressed.
- Neutralization treatment is a mass-based mixing ratio of a resin containing a structural unit derived from a nitrile group-containing monomer and a fluororesin in a composition for forming an energy device electrode (resin containing a structural unit derived from a nitrile group-containing monomer: This is particularly effective when the fluororesin is in the range of 10:90 to 50:50.
- carbon dioxide as a neutralizing agent for the basic substance, there is an advantage that the acid component hardly remains as an impurity in the composition for forming an energy device electrode.
- the pressure of carbon dioxide when introducing carbon dioxide into the composition for forming an energy device electrode is preferably 0.12 MPa to 100 MPa, more preferably 0.2 MPa to 50 MPa, and 0.3 MPa to 10 MPa. More preferably it is.
- carbon dioxide gas is dissolved in the composition for forming an energy device electrode in a pressurized state, the concentrations of carbon dioxide, carbonic acid, carbonate ions and bicarbonate ions in the composition for forming an energy device electrode can be increased.
- excess carbon dioxide gas in the energy device electrode forming composition may be removed.
- the method for removing excess carbon dioxide from the composition for forming an energy device electrode is not particularly limited.
- a cavitation method in which cavitation (local boiling) is generated in the composition for forming an energy device electrode and deaerated may be used.
- the composition for energy device electrode formation may contain the solvent. Since carbon dioxide gas can be dissolved in a solvent such as N-methyl-2-pyrrolidone in addition to water, the neutralization treatment is a composition for forming an energy device electrode containing water, N-methyl-2-pyrrolidone, etc. as a solvent. It is especially effective for things.
- the specific metal oxide contained in the composition for forming an energy device electrode to be subjected to the neutralization treatment may be washed or not washed.
- an appropriate viscosity to be adjusted in the slurry preparation step is 25 ° C. in the case of an N-methyl-2-pyrrolidone (NMP) solution to which 10% by mass of the composite resin for energy device electrodes is added with respect to the total amount.
- NMP N-methyl-2-pyrrolidone
- it is preferably 500 mPa ⁇ s to 50000 mPa ⁇ s, more preferably 1000 mPa ⁇ s to 20000 mPa ⁇ s, and still more preferably 2000 mPa ⁇ s to 10000 mPa ⁇ s.
- the viscosity is measured at 25 ° C. and a shear rate of 1.0 s ⁇ 1 using a rotary shear viscometer.
- the positive electrode for an energy device of the present disclosure (hereinafter sometimes simply referred to as a positive electrode) is provided on at least one surface of a positive electrode current collector and the positive electrode current collector, and the composition for forming an energy device electrode of the present disclosure A positive electrode material mixture layer containing a product.
- the positive electrode for an energy device of the present disclosure can be manufactured using a known electrode manufacturing method without particular limitation. For example, a positive electrode slurry containing the active material, the composite resin for energy device electrodes, a conductive material used as necessary, and a solvent is applied onto at least one surface of the positive electrode current collector, and then the solvent is removed by drying. And it can manufacture by rolling as needed and forming a positive mix layer on the positive electrode collector surface.
- the positive electrode slurry can be applied using, for example, a comma coater.
- the coating is suitably performed so that the ratio between the positive electrode capacity and the negative electrode capacity (negative electrode capacity / positive electrode capacity) is 1 or more in the opposing electrode.
- the coating amount of the positive electrode slurry for example, as a dry mass of the positive electrode mixture layer is preferably 5g / m 2 ⁇ 500g / m 2, more preferably from 50g / m 2 ⁇ 300g / m 2, 100g More preferably, it is / m 2 to 200 g / m 2 .
- the larger the coating amount the easier it is to obtain a large capacity lithium ion secondary battery, and the smaller the coating amount, the easier it is to obtain a high output lithium ion secondary battery.
- the solvent is removed, for example, preferably by drying at 50 ° C. to 150 ° C., more preferably 80 ° C. to 120 ° C., preferably for 1 minute to 20 minutes, more preferably for 3 minutes to 10 minutes. Rolling is performed using, for example, a roll press.
- the bulk density of the positive electrode mixture layer is, for example, preferably 2 g / cm 3 to 5 g / cm 3 , and more preferably 2.5 g / cm 3 to 4 g / cm 3 .
- vacuum drying may be performed at 100 to 150 ° C. for 1 to 20 hours.
- the positive electrode current collector those commonly used in the field of energy devices can be used. Specifically, a sheet containing stainless steel, aluminum, titanium, or the like, a foil, or the like can be given. Among these, an aluminum sheet or foil is preferable from an electrochemical viewpoint and cost.
- the thickness of the sheet and foil is not particularly limited and is, for example, preferably 1 ⁇ m to 500 ⁇ m, more preferably 2 ⁇ m to 100 ⁇ m, and still more preferably 5 ⁇ m to 50 ⁇ m.
- the energy device of this indication contains the positive electrode for energy devices of this indication.
- Examples of the energy device of the present disclosure include a lithium ion secondary battery, an electric double layer capacitor, a solar cell, and a fuel cell.
- a lithium ion secondary battery that is an example of the energy device of the present disclosure can be obtained by combining the positive electrode for energy device of the present disclosure, the negative electrode for energy device, and the electrolytic solution.
- the energy device of the present disclosure is preferably applied to a non-aqueous electrolyte-based energy device.
- a non-aqueous electrolyte-type energy device refers to an electricity storage or power generation device (apparatus) that uses an electrolyte containing a solvent other than water.
- the lithium ion secondary battery includes, for example, a positive electrode for energy device, a negative electrode for energy device, a separator interposed between the positive electrode for energy device and the negative electrode for energy device, and an electrolytic solution.
- the positive electrode for energy devices of this indication is used as a positive electrode for energy devices.
- the negative electrode for energy devices (hereinafter sometimes simply referred to as a negative electrode) has a negative electrode current collector and a negative electrode mixture layer provided on at least one surface of the negative electrode current collector.
- the negative electrode mixture layer has a negative electrode active material, a binder resin, and, if necessary, a conductive material.
- the negative electrode active material those commonly used in the field of energy devices can be used. Specific examples include lithium metal, lithium alloy, metal compound, carbon material, metal complex, and organic polymer compound.
- a negative electrode active material may be used individually by 1 type, and may be used in combination of 2 or more type. Among these, a carbon material is preferable as the negative electrode active material.
- Carbon materials include natural graphite (flaky graphite, etc.), graphite such as artificial graphite, carbon black such as acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, amorphous carbon, carbon fiber Etc.
- the average particle size of the carbon material is preferably 0.1 ⁇ m to 60 ⁇ m, more preferably 0.3 ⁇ m to 45 ⁇ m, and even more preferably 0.5 ⁇ m to 30 ⁇ m.
- the BET specific surface area of the carbon material is preferably 1 m 2 / g to 10 m 2 / g.
- the distance between the carbon hexagonal planes (d 002 ) in the X-ray wide angle diffraction method is 3.35 to 3.40 cm, and the c-axis Graphite having a direction crystallite (Lc) of 100 or more is preferable.
- amorphous carbon spacing carbon hexagonal plane in the X-ray wide angle diffraction method (d 002) is at 3.50 ⁇ ⁇ 3.95 ⁇ Is preferred.
- the average particle size is a volume-based particle size distribution measured with a laser diffraction particle size distribution analyzer (for example, SALD-3000J, manufactured by Shimadzu Corporation) by dispersing a sample in purified water containing a surfactant. , The value when the integration from the small diameter side becomes 50% (median diameter (D50)).
- a BET specific surface area can be measured from nitrogen adsorption capacity according to JIS Z 8830: 2013, for example.
- the evaluation apparatus for example, AUTOSORB-1 (trade name) manufactured by QUANTACHROME can be used.
- pretreatment for removing water by heating when measuring the BET specific surface area.
- a measurement cell charged with 0.05 g of a measurement sample is depressurized to 10 Pa or less with a vacuum pump, heated at 110 ° C. and held for 3 hours or more, and then kept at a normal temperature ( Cool to 25 ° C).
- the evaluation temperature is 77K
- the evaluation pressure range is measured as a relative pressure (equilibrium pressure with respect to saturated vapor pressure) of less than 1.
- the surface spacing d 002 of the 002 plane of the carbon material is such that the diffraction angle 2 ⁇ appears in the vicinity of 24 ° to 26 ° from the diffraction profile obtained by irradiating the sample with X-rays (CuK ⁇ rays) and measuring the diffraction lines with a goniometer. It can be calculated from the diffraction peak corresponding to the carbon 002 plane using the Bragg equation.
- the negative electrode current collector used for the negative electrode for energy devices those commonly used in the field of energy devices can be used.
- a sheet containing stainless steel, nickel, copper, or the like, a foil, or the like can be given.
- the average thickness of the sheet and foil is not particularly limited, and is, for example, preferably 1 ⁇ m to 500 ⁇ m, more preferably 2 ⁇ m to 100 ⁇ m, and further preferably 5 ⁇ m to 50 ⁇ m.
- a conductive material may be used from the viewpoint of reducing the resistance of the electrode.
- the conductive material those commonly used in the field of energy devices can be used. Specific examples include carbon black, graphite, carbon fiber, and metal fiber. Examples of carbon black include acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal black. Examples of graphite include natural graphite and artificial graphite.
- a conductive material may be used individually by 1 type, and may be used in combination of 2 or more type.
- binder resin used for the negative electrode for energy devices those commonly used in the field of energy devices can be used. Specific examples include polytetrafluoroethylene, polyvinylidene fluoride, styrene butadiene rubber, and acrylic rubber. Among these binder resins, styrene butadiene rubber and acrylic rubber are preferable from the viewpoint of further improving the characteristics of the lithium ion secondary battery.
- the negative electrode for an energy device can be manufactured using a known electrode manufacturing method without any particular limitation.
- a negative electrode active material, a binder resin, and a slurry containing a conductive material and a solvent used as necessary are applied on at least one surface of the negative electrode current collector, and then the solvent is removed by drying. It can manufacture by rolling as needed and forming a negative mix layer on the negative electrode collector surface.
- the solvent used in the negative electrode slurry is not particularly limited as long as it can uniformly dissolve or disperse the binder resin.
- styrene butadiene rubber is used for the binder resin
- water widely used as a dispersion medium for the binder resin is preferable.
- a solvent may be used individually by 1 type and may be used in combination of 2 or more type.
- a thickener can be added to the negative electrode slurry for producing the negative electrode mixture layer in order to improve the dispersion stability and coating property of the negative electrode slurry.
- thickeners include carboxymethylcellulose, carboxymethylcellulose derivatives such as sodium carboxymethylcellulose, polyvinyl alcohol, polyvinylpyrrolidone, water-soluble alginic acid derivatives, gelatin, carrageenan, glucomannan, pectin, curdlan, gellan gum, polyacrylic acid and alkali metals thereof.
- examples thereof include polyacrylic acid derivatives such as salts, ethylene- (meth) acrylic acid copolymers, polyvinyl alcohol copolymers such as polyvinyl alcohol and ethylene-vinyl alcohol copolymers.
- a carboxymethyl cellulose derivative is preferable.
- coating of a negative electrode slurry can be performed using a comma coater etc., for example.
- the coating is suitably performed so that the ratio between the positive electrode capacity and the negative electrode capacity (negative electrode capacity / positive electrode capacity) is 1 or more in the opposing electrode.
- the coating amount of the negative electrode slurry is, for example, that the dry mass of the negative electrode mixture layer is preferably 5 g / m 2 to 300 g / m 2 , more preferably 25 g / m 2 to 200 g / m 2 , and 50 g More preferably, it is / m 2 to 150 g / m 2 .
- the larger the coating amount the easier it is to obtain a large capacity lithium ion secondary battery, and the smaller the coating amount, the easier it is to obtain a high output lithium ion secondary battery.
- the removal of the solvent is performed, for example, preferably by drying at 50 ° C. to 150 ° C., more preferably 80 ° C. to 120 ° C., preferably 1 minute to 20 minutes, more preferably 3 minutes to 10 minutes. Rolling is performed using, for example, a roll press.
- the bulk density of the negative electrode mixture layer is, for example, is preferably 1g / cm 3 ⁇ 2g / cm 3, more preferably from 1.2g / cm 3 ⁇ 1.8g / cm 3, 1.4g / More preferably, it is cm 3 to 1.6 g / cm 3 .
- vacuum drying may be performed at 100 ° C. to 150 ° C. for 1 hour to 20 hours.
- the separator is not particularly limited as long as it has ion permeability while electronically insulating between the positive electrode and the negative electrode, and has resistance to oxidation on the positive electrode side and reducibility on the negative electrode side.
- a material (material) of the separator that satisfies such characteristics a resin, an inorganic substance, or the like is used.
- an olefin polymer As the resin, an olefin polymer, a fluorine polymer, a cellulose polymer, polyimide, nylon, or the like is used. Specifically, it is preferable to select from materials that are stable with respect to the electrolytic solution and have excellent liquid retention properties, and it is preferable to use a porous sheet made of polyolefin such as polyethylene and polypropylene, a nonwoven fabric, and the like.
- inorganic substances include oxides such as alumina and silicon dioxide, nitrides such as aluminum nitride and silicon nitride, sulfates such as barium sulfate and calcium sulfate, and glass.
- oxides such as alumina and silicon dioxide
- nitrides such as aluminum nitride and silicon nitride
- sulfates such as barium sulfate and calcium sulfate
- glass glass
- thin film-shaped base materials such as a nonwoven fabric, a woven fabric, and a microporous film
- the thin film-shaped substrate those having an average pore diameter of 0.01 ⁇ m to 1 ⁇ m and an average thickness of 5 ⁇ m to 50 ⁇ m are preferably used.
- the composite porous layer using binders, such as resin can be used as a separator.
- this composite porous layer may be formed on the surface of the positive electrode or the negative electrode to form a separator.
- this composite porous layer may be formed on the surface of another separator to form a multilayer separator.
- a separator in which a composite porous layer obtained by binding alumina particles having a 90% diameter (D90) of less than 1 ⁇ m using a fluororesin as a binder may be used as a separator.
- the electrolyte solution is not particularly limited as long as it functions as a lithium ion secondary battery that is an energy device, for example.
- an electrolytic solution containing a solvent other than water nonaqueous electrolytic solution
- non-aqueous electrolytes include carbonates such as propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, and methyl ethyl carbonate, lactones such as ⁇ -butyrolactone, trimethoxymethane, and 1,2-dimethoxy.
- Ethers such as ethane, diethyl ether, 2-ethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, sulfoxides such as dimethyl sulfoxide, oxolanes such as 1,3-dioxolane, 4-methyl-1,3-dioxolane, acetonitrile, Nitrogen-containing compounds such as nitromethane and N-methyl-2-pyrrolidone, esters such as methyl formate, methyl acetate, butyl acetate, methyl propionate, ethyl propionate, and phosphate triester, di Glymes such as lime, triglyme and tetraglyme, ketones such as acetone, diethyl ketone, methyl ethyl ketone and methyl isobutyl ketone, sulfones such as sulfolane, oxazolidinones such as 3-methyl-2-
- VC vinylene carbonate
- the content when vinylene carbonate (VC) is contained is preferably 0.1% by mass to 2% by mass, and more preferably 0.2% by mass to 1.5% by mass with respect to the total amount of the electrolytic solution.
- two electrodes are wound through a separator made of a polyethylene microporous film.
- the obtained spiral wound group is inserted into a battery can, and a tab terminal previously welded to a negative electrode current collector is welded to the bottom of the battery can.
- An electrolytic solution is injected into the obtained battery can.
- a tab terminal that has been previously welded to the positive electrode current collector is welded to the battery lid, and the lid is placed on the top of the battery can via an insulating gasket.
- a lithium ion secondary battery is obtained by caulking and sealing.
- a resin (resin 1) containing a structural unit derived from a nitrile group-containing monomer a resin containing a structural unit derived from a nitrile group-containing monomer.
- a resin containing a structural unit derived from a nitrile group-containing monomer is referred to as a PAN-based resin.
- NMP N-methyl methacrylate
- 27 g of powder of PAN resin (resin 1) was added, and 300 g
- the mixture was stirred for 5 hours at a rotation / min to obtain an NMP solution of a PAN-based resin (resin 1).
- the obtained lithium-containing carbonate was put in a firing furnace, heated to 850 ° C. over 6 hours, then heated and held for 2 hours, and then cooled to obtain an oxide.
- the obtained oxide was crushed to obtain a positive electrode active material A.
- the positive electrode active material A is referred to as NCA.
- the metal salt solution was prepared using a nitrate hydrate of nickel, cobalt, and manganese.
- a positive electrode active material B was obtained in the same manner as the positive electrode active material A except that the composition ratio was adjusted to mol%: 10 mol%: 10 mol%.
- the positive electrode active material B is referred to as NMC (811).
- Example 1 NCA (positive electrode active material), acetylene black (conductive material, Denka Black HS-100, manufactured by Denka Co., Ltd.), PAN-based resin (resin 1) (resin containing a structural unit derived from a nitrile group-containing monomer), and PVDF (Fluororesin) is mixed so that the ratio of the solid content is 98.0% by mass: 1.0% by mass: 0.8% by mass: 0.2% by mass, and NMP is added to adjust the viscosity.
- a slurry was prepared.
- NMP uses an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., TV-35), and the viscosity of the slurry is 2000 mPa ⁇ s to 5000 mPa ⁇ s measured at 25 ° C. and 0.5 rpm. The amount was added. The room temperature and humidity when producing the positive electrode slurry were 55 ⁇ 1% RH at 25 ⁇ 1 ° C.
- Example 2 The same method as in Example 1 except that NCA, acetylene black, PAN-based resin, and PVDF had a solid content ratio of 98.0% by mass: 1.0% by mass: 0.7% by mass: 0.3% by mass. A positive electrode slurry was prepared.
- Example 3 The same method as in Example 1 except that NCA, acetylene black, PAN resin, and PVDF had a solid content ratio of 98.0% by mass: 1.0% by mass: 0.6% by mass: 0.4% by mass. A positive electrode slurry was prepared.
- Example 4 The same method as in Example 1 except that NCA, acetylene black, PAN-based resin, and PVDF had a solid content ratio of 98.0% by mass: 1.0% by mass: 0.5% by mass: 0.5% by mass. A positive electrode slurry was prepared.
- Example 5 A positive electrode slurry was prepared in the same manner as in Example 1 except that the positive electrode active material was NMC (811).
- Example 6 A positive electrode slurry was prepared in the same manner as in Example 2 except that the positive electrode active material was NMC (811).
- Example 7 A positive electrode slurry was prepared in the same manner as in Example 3 except that the positive electrode active material was NMC (811).
- Example 8 A positive electrode slurry was prepared in the same manner as in Example 4 except that the positive electrode active material was NMC (811).
- Example 9 to Example 16 A positive electrode slurry was prepared in the same manner as in Examples 1 to 8 except that the PAN resin (resin 2) was used instead of the PAN resin (resin 1).
- Examples 17 to 24 A positive electrode slurry was prepared in the same manner as in Examples 1 to 8 except that the PAN resin (resin 3) was used instead of the PAN resin (resin 1).
- NMC 811 W (positive electrode active material) and acetylene black (conductive material, Denka Black HS-100, manufactured by Denka Co., Ltd.) and PAN resin (resin 1) (including structural units derived from nitrile group-containing monomers) Resin) and PVDF (fluororesin) are mixed so that the ratio of the solid content is 98.0% by mass: 1.0% by mass: 0.15% by mass: 0.85% by mass, and NMP is used for viscosity adjustment.
- NMP is used for viscosity adjustment.
- NMP uses an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., TV-35), and the viscosity of the slurry is 2000 mPa ⁇ s to 5000 mPa ⁇ s measured at 25 ° C. and 0.5 rpm. The amount was added. The room temperature and humidity when producing the positive electrode slurry were 55 ⁇ 1% RH at 25 ⁇ 1 ° C.
- Example 26 A positive electrode slurry was prepared in the same manner as in Example 25 except that the positive electrode active material was NCA (W).
- Example 2 Example 1 except that NCA, acetylene black, PAN-based resin (resin 1), and PVDF had a solid content ratio of 98.0% by mass: 1.0% by mass: 0% by mass: 1.0% by mass.
- a positive electrode slurry was prepared by this method.
- Comparative Example 3 A positive electrode slurry was prepared in the same manner as in Comparative Example 1, except that the positive electrode active material was NMC (811).
- Comparative Example 4 A positive electrode slurry was prepared in the same manner as in Comparative Example 2, except that NMC (811) was used as the positive electrode active material.
- Viscosity stability of positive electrode slurry 20 g of the prepared positive electrode slurry was put into a glass sample tube bottle (manufactured by ASONE Co., Ltd., 30 cc) and sealed in a substantially horizontal environment at 25 ⁇ 1 ° C. The mixture was allowed to stand on a table, and the viscosity one day after production was measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., TV-35) at 25 ° C. and 0.5 rpm. The rate of change in viscosity was calculated according to the following equation, and the viscosity stability of the positive electrode slurry was evaluated according to the following criteria.
- Viscosity change rate (%) [(viscosity after standing-viscosity before standing) / viscosity after standing] ⁇ 100
- D Viscosity change rate is less than -60% or 300% or more
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Inorganic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Composite Materials (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Abstract
Description
<1> ニトリル基含有単量体由来の構造単位を含む樹脂及びフッ素樹脂を含有するエネルギーデバイス電極用複合樹脂。
<2> リチウムとニッケルとを有しリチウムを除く金属に占めるニッケルの割合が50モル%以上であるリチウム含有金属複合酸化物を含む正極活物質を含有する正極合剤層の形成に用いられる<1>に記載のエネルギーデバイス電極用複合樹脂。
<3> 前記リチウム含有金属複合酸化物が、下記式(I)で表される化合物を含む<2>に記載のエネルギーデバイス電極用複合樹脂。
LiaNibCocMdO2+e 式(I)
(式(I)中、Mは、Al、Mn、Mg及びCaからなる群より選択される少なくとも1種であり、a、b、c、d及びeは、各々0.2≦a≦1.2であり、0.5≦b≦0.9であり、0.05≦c≦0.4であり、0≦d≦0.2であり、-0.2≦e≦0.2であり、b+c+d=1である。)
<4> 前記ニトリル基含有単量体由来の構造単位を含む樹脂が、下記式(II)で表される単量体由来の構造単位をさらに含む<1>~<3>のいずれか1項に記載のエネルギーデバイス電極用複合樹脂。
<5> 前記ニトリル基含有単量体由来の構造単位を含む樹脂に含有される前記ニトリル基含有単量体由来の構造単位1モルに対する前記式(II)で表される単量体由来の構造単位の比率が、0.001モル~0.2モルである<4>に記載のエネルギーデバイス電極用複合樹脂。
<6> 前記ニトリル基含有単量体由来の構造単位を含む樹脂が、下記式(III)で表される単量体由来の構造単位をさらに含む<1>~<5>のいずれか1項に記載のエネルギーデバイス電極用複合樹脂。
<7> 前記ニトリル基含有単量体由来の構造単位を含む樹脂に含有される前記ニトリル基含有単量体由来の構造単位1モルに対する前記式(III)で表される単量体由来の構造単位の比率が、0.001モル~0.2モルである<6>に記載のエネルギーデバイス電極用複合樹脂。
<8> 前記ニトリル基含有単量体が、アクリロニトリルを含む<1>~<7>のいずれか1項に記載のエネルギーデバイス電極用複合樹脂。
<9> 前記フッ素樹脂が、ポリフッ化ビニリデン(PVDF)を含む<1>~<8>のいずれか1項に記載のエネルギーデバイス電極用複合樹脂。
<10> リチウムとニッケルとを有しリチウムを除く金属に占めるニッケルの割合が50モル%以上であるリチウム含有金属複合酸化物を含む正極活物質と、<1>~<9>のいずれか1項に記載のエネルギーデバイス電極用複合樹脂と、を含有するエネルギーデバイス電極形成用組成物。
<11> 前記リチウム含有金属複合酸化物が、下記式(I)で表される化合物を含む<10>に記載のエネルギーデバイス電極形成用組成物。
LiaNibCocMdO2+e 式(I)
(式(I)中、Mは、Al、Mn、Mg及びCaからなる群より選択される少なくとも1種であり、a、b、c、d及びeは、各々0.2≦a≦1.2であり、0.5≦b≦0.9であり、0.05≦c≦0.4であり、0≦d≦0.2であり、-0.2≦e≦0.2であり、b+c+d=1である。)
<12> 正極集電体と、
前記正極集電体の少なくとも一方の表面上に設けられ、<10>又は<11>に記載のエネルギーデバイス電極形成用組成物を含む正極合剤層と、
を有するエネルギーデバイス用正極。
<13> <12>に記載のエネルギーデバイス用正極を含むエネルギーデバイス。
<14> 前記エネルギーデバイスが、リチウムイオン二次電池である<13>に記載のエネルギーデバイス。
本明細書において「~」を用いて示された数値範囲には、「~」の前後に記載される数値がそれぞれ最小値及び最大値として含まれる。
本明細書中に段階的に記載されている数値範囲において、一つの数値範囲で記載された上限値又は下限値は、他の段階的な記載の数値範囲の上限値又は下限値に置き換えてもよい。また、本明細書中に記載されている数値範囲において、その数値範囲の上限値又は下限値は、実施例に示されている値に置き換えてもよい。
本明細書において組成物中の各成分の含有率は、組成物中に各成分に該当する物質が複数種存在する場合、特に断らない限り、組成物中に存在する当該複数種の物質の合計の含有率を意味する。
本明細書において組成物中の各成分の粒子径は、組成物中に各成分に該当する粒子が複数種存在する場合、特に断らない限り、組成物中に存在する当該複数種の粒子の混合物についての値を意味する。
本明細書において「層」又は「膜」との語には、当該層又は膜が存在する領域を観察したときに、当該領域の全体に形成されている場合に加え、当該領域の一部にのみ形成されている場合も含まれる。
本明細書において「(メタ)アクリル」はアクリル及びメタクリルの少なくとも一方を意味し、「(メタ)アクリレート」はアクリレート及びメタクリレートの少なくとも一方を意味する。
本明細書において「バインダ樹脂」とは、活物質等の粒子同士を結着させる機能を有する樹脂をいう。
本開示のエネルギーデバイス電極用複合樹脂は、ニトリル基含有単量体由来の構造単位を含む樹脂及びフッ素樹脂を含有する。本開示のエネルギーデバイス電極用複合樹脂は、リチウムとニッケルとを有しリチウムを除く金属に占めるニッケルの割合が50モル%以上であるリチウム含有金属複合酸化物(以下、特定金属酸化物と称することがある。)を含む正極活物質を含有する正極合剤層の形成に用いてもよい。
その理由は明確ではないが、以下のように推察される。
なお、本開示において「スラリーの沈降」とは、N-メチル-2-ピロリドン(NMP)等の溶媒に正極活物質、導電性材料、バインダ樹脂等を混合したスラリー内で、正極活物質が沈降する現象を指す。正極活物質が沈降したスラリーを用いて集電箔上に正極合剤層を形成した場合、正極合剤層の均質性が損なわれることがあり、場合によっては、塗工機の不具合を誘発する恐れがある。
一方、ニトリル基含有単量体由来の構造単位を含む樹脂中のニトリル基は、フッ素原子に比較して塩基性物質と接触した際の脱離反応が生じにくい。そのため、ニトリル基含有単量体由来の構造単位を含む樹脂は、フッ素樹脂に比較して、塩基性物質と接触した際に変質しにくい傾向にある。
一方、PVDF等のフッ素樹脂は、フッ素樹脂中にフッ素原子が含まれるため粒子状の導電性材料を分散させにくく、導電性材料の高次構造を形成しやすい。そのため、導電性材料の高次構造内で正極活物質が保持されやすくなり、スラリーが沈降しにくい傾向にある。
特に、特定金属酸化物を含む正極活物質を用いた場合であっても、スラリーがゲル化しにくい。さらには、合剤層に占める導電性材料の含有率が1.5質量%以下のスラリーであっても、スラリーの沈降が生じにくい。
さらに、本開示においてニトリル基含有単量体由来の構造単位を含む樹脂は、ニトリル基含有単量体由来の構造単位を主鎖に含み、且つポリエチレン骨格中における水素原子の一部又は全部をフッ素原子に置換した構造単位を主鎖に含まない樹脂をいう。
本開示のエネルギーデバイス電極用複合樹脂は、ニトリル基含有単量体由来の構造単位を含む樹脂を含有する。
本開示で用いられるニトリル基含有単量体としては、特に制限はない。ニトリル基含有単量体としては、アクリロニトリル、メタクリロニトリル等のアクリル系ニトリル基含有単量体、α-シアノアクリレート、ジシアノビニリデン等のシアン系ニトリル基含有単量体、フマロニトリル等のフマル系ニトリル基含有単量体などが挙げられる。
これらの中では、重合のし易さ、コストパフォーマンス、電極の柔軟性、可とう性、耐酸化性、電解液に対する耐膨潤性等の点で、アクリロニトリルが好ましい。ニトリル基含有単量体に占めるアクリロニトリルの比率は、例えば、5質量%~100質量%であることが好ましく、50質量%~100質量%であることがより好ましく、70質量%~100質量%であることがさらに好ましい。これらのニトリル基含有単量体は、1種を単独で用いてもよく、2種以上を組み合わせて用いてもよい。
ニトリル基含有単量体としてアクリロニトリルとメタクリロニトリルとを併用する場合、アクリロニトリルの含有率は、ニトリル基含有単量体の全量に対して、例えば、5質量%~95質量%であることが好ましく、50質量%~95質量%であることがより好ましい。
本開示で用いられるニトリル基含有単量体由来の構造単位を含む樹脂は、電極の柔軟性の観点から、式(II)で表される単量体由来の構造単位をさらに含むことが好ましい。
nは1~50の整数を示し、ある態様では、2~30の整数であることが好ましく、2~15の整数であることがより好ましく、2~10の整数であることがさらに好ましい。また、その他の態様では、nは1~30の整数であることが好ましく、1~15の整数であることがより好ましく、1~10の整数であることがさらに好ましい。
R2は、水素原子又は1価の炭化水素基を示し、例えば、炭素数が1~30である1価の炭化水素基であることが好ましく、炭素数が1~25である1価の炭化水素基であることがより好ましく、炭素数が1~12である1価の炭化水素基であることがさらに好ましい。なお、1価の炭化水素基が置換基を有する場合、当該1価の炭化水素基の炭素数には、置換基に含まれる炭素数は含まれないものとする。
R2が水素原子であるか、又は炭素数が1~30である1価の炭化水素基であれば、電解液に対する十分な耐膨潤性を得ることができる傾向にある。ここで、1価の炭化水素基としては、例えば、アルキル基及びフェニル基が挙げられる。R2は、炭素数が1~12のアルキル基又はフェニル基であることが好ましい。アルキル基は、直鎖であっても分岐鎖であっても環状であってもよい。
R2で示されるアルキル基及びフェニル基は、一部の水素原子が置換基で置換されていてもよい。R2がアルキル基である場合の置換基としては、フッ素原子、塩素原子、臭素原子、ヨウ素原子等のハロゲン原子、窒素原子を含む置換基、リン原子を含む置換基、芳香環などが挙げられる。R2がフェニル基である場合の置換基としては、フッ素原子、塩素原子、臭素原子、ヨウ素原子等のハロゲン原子、窒素原子を含む置換基、リン原子を含む置換基、芳香環、炭素数が3~10の直鎖、分岐鎖又は環状のアルキル基などが挙げられる。
これらの中では、アクリロニトリル等のニトリル基含有単量体と共重合させる場合の反応性などの点から、メトキシトリエチレングリコールアクリレート(一般式(II)のR1がH、R2がCH3、nが3)がより好ましい。これらの式(II)で表される単量体は、1種を単独で用いてもよく、2種以上を組み合わせて用いてもよい。
本開示で用いられるニトリル基含有単量体由来の構造単位を含む樹脂は、電極の柔軟性の観点から、式(III)で表される単量体由来の構造単位をさらに含むことが好ましい。
R4で示されるアルキル基は、直鎖状であっても分岐鎖状であっても環状であってもよい。
R4で示されるアルキル基は、一部の水素原子が置換基で置換されていてもよい。置換基としては、フッ素原子、塩素原子、臭素原子、ヨウ素原子等のハロゲン原子、窒素原子を含む置換基、リン原子を含む置換基、芳香環、炭素数が3~10のシクロアルキル基などが挙げられる。R4で示されるアルキル基としては、直鎖状、分岐鎖状又は環状のアルキル基の他、フルオロアルキル基、クロロアルキル基、ブロモアルキル基、ヨウ化アルキル基等のハロゲン化アルキル基などが挙げられる。
また、R4がフルオロアルキル基である場合、1,1-ビス(トリフルオロメチル)-2,2,2-トリフルオロエチルアクリレート、2,2,3,3,4,4,4-ヘプタフルオロブチルアクリレート、2,2,3,4,4,4-へキサフルオロブチルアクリレート、ノナフルオロイソブチルアクリレート、2,2,3,3,4,4,5,5-オクタフルオロペンチルアクリレート、2,2,3,3,4,4,5,5,5-ノナフルオロペンチルアクリレート、2,2,3,3,4,4,5,5,6,6,6-ウンデカフルオロヘキシルアクリレート、2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-ペンタデカフルオロオクチルアクリレート、3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-ヘプタデカフルオロデシルアクリレート、2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-ノナデカフルオロデシルアクリレート等のアクリレート化合物、ノナフルオロ-t-ブチルメタクリレート、2,2,3,3,4,4,4-ヘプタフルオロブチルメタクリレート、2,2,3,3,4,4,5,5-オクタフルオロペンチルメタクリレート、2,2,3,3,4,4,5,5,6,6,7,7-ドデカフルオロヘプチルメタクリレート、ヘプタデカフルオロオクチルメタクリレート、2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-ペンタデカフルオロオクチルメタクリレート、2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-ヘキサデカフルオロノニルメタクリレート等のメタクリレート化合物などが挙げられる。
式(III)で表されるこれらの単量体は、1種を単独で用いてもよく、2種以上を組み合わせて用いてもよい。
本開示で用いられるニトリル基含有単量体由来の構造単位を含む樹脂は、集電体と合剤層との密着性の観点から、カルボキシ基含有単量体由来であってカルボキシ基を含む構造単位を含んでいてもよい。
カルボキシ基含有単量体としては、特に制限はなく、アクリル酸、メタクリル酸等のアクリル系カルボキシ基含有単量体、クロトン酸等のクロトン系カルボキシ基含有単量体、マレイン酸及びその無水物等のマレイン系カルボキシ基含有単量体、イタコン酸及びその無水物等のイタコン系カルボキシ基含有単量体、シトラコン酸及びその無水物等のシトラコン系カルボキシ基含有単量体などが挙げられる。
これらの中では、重合のし易さ、コストパフォーマンス、電極の柔軟性、可とう性等の点で、アクリル酸が好ましい。カルボキシ基含有単量体は、1種を単独で用いてもよく、2種以上を組み合わせて用いてもよい。本開示で用いられるニトリル基含有単量体由来の構造単位を含む樹脂がカルボキシ基含有単量体としてアクリル酸とメタクリル酸とを併用する場合、アクリル酸の含有率は、カルボキシ基含有単量体の全量に対して、例えば、5質量%~95質量%であることが好ましく、50質量%~95質量%であることがより好ましい。
本開示で用いられるニトリル基含有単量体由来の構造単位を含む樹脂は、ニトリル基含有単量体由来の構造単位、必要に応じて含まれる式(II)で表される単量体由来の構造単位、式(III)で表される単量体由来の構造単位及びカルボキシ基含有単量体由来であってカルボキシ基を含む構造単位の他、これらの単量体とは異なるその他の単量体由来の構造単位を適宜組合せることもできる。
その他の単量体としては、特に限定されるものではなく、メチル(メタ)アクリレート、エチル(メタ)アクリレート、プロピル(メタ)アクリレート等の短鎖(メタ)アクリル酸エステル類、塩化ビニル、臭化ビニル、塩化ビニリデン等のハロゲン化ビニル類、マレイン酸イミド、フェニルマレイミド、(メタ)アクリルアミド、スチレン、α-メチルスチレン、酢酸ビニル、(メタ)アリルスルホン酸ナトリウム、(メタ)アリルオキシベンゼンスルホン酸ナトリウム、スチレンスルホン酸ナトリウム、2-アクリルアミド-2-メチルプロパンスルホン酸及びその塩などが挙げられる。これらその他の単量体は、1種を単独で用いてもよく、2種以上を組み合わせて用いてもよい。
本開示で用いられるニトリル基含有単量体由来の構造単位を含む樹脂が、式(II)で表される単量体由来の構造単位、式(III)で表される単量体由来の構造単位及びカルボキシ基含有単量体由来であってカルボキシ基を含む構造単位からなる群より選択される少なくとも1種を含む場合、ニトリル基含有単量体由来の構造単位1モルに対する比率は、以下のモル比であることが好ましい。
ニトリル基含有単量体由来の構造単位1モルに対する式(II)で表される単量体由来の構造単位の比率が0.001モル~0.2モルの範囲であると、正極集電体、特にアルミニウム箔を用いた正極集電体との接着性及び電解液に対する耐膨潤性を損ねることなく、電極の柔軟性及び可とう性が良好となる傾向にある。
ニトリル基含有単量体由来の構造単位1モルに対する式(III)で表される単量体由来の構造単位の比率が、0.001モル~0.2モルの範囲であると、正極集電体、特にアルミニウム箔を用いた正極集電体との接着性及び電解液に対する耐膨潤性を損ねることなく、電極の柔軟性及び可とう性が良好となる傾向にある。
ニトリル基含有単量体由来の構造単位1モルに対するカルボキシ基含有単量体由来であってカルボキシ基を含む構造単位の比率が0.01モル~0.2モルの範囲であると、電極の柔軟性及び可とう性を損ねることなく、正極集電体、特にアルミニウム箔を用いた正極集電体との接着性及び電解液に対する耐膨潤性に優れる傾向にある。
ある態様では、ニトリル基含有単量体由来の構造単位を含む樹脂における、ニトリル基含有単量体由来の構造単位1モルに対するカルボキシ基含有単量体由来であってカルボキシ基を含む構造単位の比率は、0.01モル未満であってもよく、0.005モル以下であってもよく、0モルであってもよい。
本開示で用いられるニトリル基含有単量体由来の構造単位を含む樹脂を合成するための重合様式としては、沈殿重合、塊状重合、懸濁重合、乳化重合、溶液重合等が挙げられ、特に制限はない。合成のし易さ、回収、精製等の後処理のし易さなどの点で、水中沈殿重合が好ましい。
以下、水中沈殿重合について詳細に説明する。
水中沈殿重合を行う際の重合開始剤としては、重合開始効率等の点で水溶性重合開始剤が好ましい。
水溶性重合開始剤としては、過硫酸アンモニウム、過硫酸カリウム、過硫酸ナトリウム等の過硫酸塩、過酸化水素等の水溶性過酸化物、2,2’-アゾビス(2-メチルプロピオンアミジンハイドロクロライド)等の水溶性アゾ化合物、過硫酸塩等の酸化剤と亜硫酸水素ナトリウム、亜硫酸水素アンモニウム、チオ硫酸ナトリウム、ハイドロサルファイト等の還元剤と硫酸、硫酸鉄、硫酸銅等の重合促進剤とを組合せた酸化還元型(レドックス型)などが挙げられる。
なお、ニトリル基含有単量体としてアクリロニトリルを選択し、カルボキシ基含有単量体としてアクリル酸を選択し、式(II)で表される単量体としてメトキシトリエチレングリコールアクリレートを選択して水中沈殿重合を行った場合、単量体(モノマーともいう)の状態では3者ともに水溶性であることから、水溶性重合開始剤が有効に作用し、重合がスムーズに始まる。そして、重合が進むにつれて重合物が析出してくるため、反応系が懸濁状態となり、最終的に未反応物の少ないニトリル基含有単量体由来の構造単位を含む樹脂が高収率で得られる。
また、水中沈殿重合を行う際には、分子量調節等の目的で、連鎖移動剤を用いることができる。連鎖移動剤としては、メルカプタン化合物、四塩化炭素、α-メチルスチレンダイマー等が挙げられる。これらの中では、臭気が少ない等の点で、α-メチルスチレンダイマーが好ましい。
水中沈殿重合を行う際には、析出する樹脂の粒子径の調節等のため、必要に応じて、水以外の溶媒を加えることもできる。
水以外の溶媒としては、N-メチル-2-ピロリドン、N,N-ジメチルアセトアミド、N,N-ジメチルホルムアミド等のアミド類、N,N-ジメチルエチレンウレア、N,N-ジメチルプロピレンウレア、テトラメチルウレア等のウレア類、γ-ブチロラクトン、γ-カプロラクトン等のラクトン類、プロピレンカーボネート等のカーボネート類、アセトン、メチルエチルケトン、メチルイソブチルケトン、シクロヘキサノン等のケトン類、酢酸メチル、酢酸エチル、酢酸n-ブチル、ブチルセロソルブアセテート、ブチルカルビトールアセテート、エチルセロソルブアセテート、エチルカルビトールアセテート等のエステル類、ジグライム、トリグライム、テトラグライム等のグライム類、トルエン、キシレン、シクロヘキサン等の炭化水素類、ジメチルスルホキシド等のスルホキシド類、スルホラン等のスルホン類、メタノール、イソプロパノール、n-ブタノール等のアルコール類などが挙げられる。これらの溶媒は、1種を単独で用いてもよく、2種以上を組み合わせて用いてもよい。
水中沈殿重合は、例えば、ニトリル基含有単量体並びに必要に応じて用いられるカルボキシ基含有単量体、式(II)で表される単量体、式(III)で表される単量体及びその他の単量体を溶媒中に導入し、重合温度を、好ましくは0℃~100℃、より好ましくは30℃~95℃として、好ましくは1時間~50時間、より好ましくは2時間~12時間保持することによって行われる。
本開示において、重量平均分子量は下記方法により測定された値をいう。
測定対象をN-メチル-2-ピロリドンに溶解し、PTFE(ポリテトラフルオロエチレン)製フィルタ〔倉敷紡績株式会社製、HPLC(高速液体クロマトグラフィー)前処理用、クロマトディスク、型番:13N、孔径:0.45μm〕を通して不溶分を除去する。GPC〔ポンプ:L6200 Pump(株式会社日立製作所製)、検出器:示差屈折率検出器L3300 RI Monitor(株式会社日立製作所製)、カラム:TSKgel-G5000HXLとTSKgel-G2000HXL(計2本)(共に東ソー株式会社製)を直列に接続、カラム温度:30℃、溶離液:N-メチル-2-ピロリドン、流速:1.0ml/分、標準物質:ポリスチレン〕を用い、重量平均分子量を測定する。
まず、測定対象1gを精秤した後、その測定対象にアセトンを30g添加し、測定対象を溶解する。次いで、指示薬であるフェノールフタレインを測定対象の溶液に適量添加して、0.1NのKOH水溶液を用いて滴定する。そして、滴定結果より下記式(A)により酸価を算出する(式中、Vfはフェノールフタレインの滴定量(mL)を示し、Wpは測定対象の溶液の質量(g)を示し、Iは測定対象の溶液の不揮発分の割合(質量%)を示す。)。
酸価(mgKOH/g)=10×Vf×56.1/(Wp×I) (A)
なお、測定対象の溶液の不揮発分は、測定対象の溶液をアルミパンに約1ml量り取り、160℃に加熱したホットプレート上で15分間乾燥させ、残渣質量から算出する。
本開示のエネルギーデバイス電極用複合樹脂は、フッ素樹脂を含む。本開示で用いられるフッ素樹脂は、主鎖に、ポリエチレン骨格中における水素原子の一部又は全部をフッ素原子に置換した構造単位を含む樹脂であれば、特に制限がない。
フッ素樹脂としては、ポリテトラフルオロエチレン(PTFE)、ポリフッ化ビニリデン(PVDF)、ポリビニルフルオライド(PVF)、ポリクロロトリフルオロエチレン(PCTFE)等のホモポリマー、テトラフルオロエチレン-パーフルオロプロピレン共重合体(FEP)、テトラフルオロエチレン-パーフルオロプロピレン共重合体(PFA)、テトラフルオロエチレン-エチレン共重合体(ETFE)、クロロトリフルオロエチレン-エチレン共重合体等の共重合体、またこれらにカルボキシ基等を変性した変性物などが挙げられる。これらの中でも、溶媒への溶解性、電解液への膨潤性、樹脂の柔軟性等の観点から、PVDFが好ましい。また、これらフッ素樹脂は、1種を単独で用いてもよく、2種以上を組み合わせて用いてもよい。
本開示のエネルギーデバイス電極用複合樹脂の組成は、ニトリル基含有単量体由来の構造単位を含む樹脂及びフッ素樹脂を含むものであれば特に限定されるものではない。
ある態様では、ニトリル基含有単量体由来の構造単位を含む樹脂及びフッ素樹脂の質量基準の混合比(ニトリル基含有単量体由来の構造単位を含む樹脂:フッ素樹脂)は、90:10~50:50であることが好ましい。本開示のエネルギーデバイス電極用複合樹脂を含むスラリーの性状は、ニトリル基含有単量体由来の構造単位を含む樹脂の割合が多いほど、ゲル化しにくい傾向にあり、フッ素樹脂が多いほど、スラリー中の活物質が沈降し難い傾向にある。
また、ニトリル基含有単量体由来の構造単位を含む樹脂とフッ素樹脂とでは、電解液に対する膨潤性が異なるため、電池特性としては、ニトリル基含有単量体由来の構造単位を含む樹脂が多いほど、サイクル特性が向上する傾向にあり、フッ素樹脂が多いほど、電池抵抗が低くなる傾向にある。これらの傾向から、ニトリル基含有単量体由来の構造単位を含む樹脂及びフッ素樹脂の質量基準の混合比(ニトリル基含有単量体由来の構造単位を含む樹脂:フッ素樹脂)は、90:10~55:45であることがより好ましく、80:20~60:40であることがさらに好ましく、75:25~65:35であることが特に好ましい。
ニトリル基含有単量体由来の構造単位を含む樹脂及びフッ素樹脂の質量基準の混合比が10:90~50:50である本開示のエネルギーデバイス電極用複合樹脂は、後述する洗浄処理された特定金属酸化物と組み合わせた場合に、エネルギーデバイスからのガスの発生が抑制される傾向にある。
本開示のエネルギーデバイス電極形成用組成物は、特定金属酸化物を含む正極活物質と、本開示のエネルギーデバイス電極用複合樹脂と、を含有する。
以下に、本開示のエネルギーデバイス電極形成用組成物に含まれる各成分について説明する。なお、本開示のエネルギーデバイス電極形成用組成物に含まれる本開示のエネルギーデバイス電極用複合樹脂の好ましい態様は、上述の通りである。
本開示のエネルギーデバイス電極形成用組成物に含まれる正極活物質は、特定金属酸化物を含む。特定金属酸化物を正極活物質として用いることで、例えば、エネルギーデバイスの一例であるリチウムイオン二次電池のエネルギー密度を向上することができる。
また、特定金属酸化物を正極活物質として用いた場合でも、特定金属酸化物と本開示のエネルギーデバイス電極用複合樹脂とを組み合わせることで、本開示のエネルギーデバイス電極形成用組成物を含むスラリーのゲル化及びスラリーの沈降が抑制される。
式(I)中、Mは、Al、Mn、Mg及びCaからなる群より選択される少なくとも1種であり、a、b、c、d及びeは、各々0.2≦a≦1.2であり、0.5≦b≦0.9であり、0.05≦c≦0.4であり、0≦d≦0.2であり、-0.2≦e≦0.2であり、b+c+d=1である。また、リチウムのモル比を示すaは、充放電により増減する。
また、Coの割合が大きくなるほど、正極活物質の放電性能が向上し、Coの割合が小さいほど、正極活物質の容量密度が大きくなる傾向にあることから、Coの割合(c)は、0.05≦c≦0.4であることが好ましく、0.1≦c≦0.4であることがより好ましい。
中でも硝酸塩は、後の焼成工程中で酸化剤として機能するため焼成原料中の金属の酸化を促進させやすく、また、焼成により揮発するため正極活物質中に残存し難いことから好ましい。金属塩溶液に含まれる各金属のモル比は、作製する正極活物質の各金属のモル比と同等にすることが好ましい。
例えば、所定量の特定金属酸化物と洗浄液とを十分に撹拌した後、静置し、次いで、濾過、デカンテーション等の公知の方法により固液分離して特定金属酸化物を採取することで、特定金属酸化物を洗浄することができる。
特定金属酸化物を洗浄することによって、特定金属酸化物の結晶間等に残存し電池特性の低下の要因となるLiOH等の塩基性物質を低減させることができる。そのため、ニトリル基含有単量体由来の構造単位を含む樹脂及びフッ素樹脂の質量基準の混合比(ニトリル基含有単量体由来の構造単位を含む樹脂:フッ素樹脂)が10:90~50:50とフッ素樹脂の比率が大きくてもスラリーがゲル化しにくく、さらにエネルギーデバイスからのガスの発生が抑制される傾向にある。
本開示のエネルギーデバイス電極形成用組成物がその他のリチウム含有金属複合酸化物を併用する場合、正極活物質に占める特定金属酸化物の割合は、70質量%以上であることが好ましく、80質量%以上であることがより好ましく、90質量%以上であることがさらに好ましい。
正極活物質は1種を単独で用いてもよく、2種以上を組み合わせて用いてもよい。
本開示のエネルギーデバイス電極形成用組成物は、電極の抵抗を低減する観点から、導電性材料を含んでもよい。導電性材料としては、エネルギーデバイスの分野で常用されるものを使用できる。具体的には、カーボンブラック、黒鉛、炭素繊維、金属繊維等が挙げられる。カーボンブラックとしては、例えば、アセチレンブラック、ケッチェンブラック、チャンネルブラック、ファーネスブラック、ランプブラック及びサーマルブラックが挙げられる。黒鉛としては、例えば、天然黒鉛及び人造黒鉛が挙げられる。導電性材料は1種を単独で用いてもよく、2種以上を組み合わせて用いてもよい。
本開示のエネルギーデバイス電極形成用組成物を電極形成用のスラリーとして用いる場合、エネルギーデバイス電極形成用組成物は溶媒を含んでいてもよい。
スラリーに用いられる溶媒としては、特に制限はなく、本開示のエネルギーデバイス電極用複合樹脂を均一に溶解又は分散できる溶媒であればよい。このような溶媒としては、本開示のエネルギーデバイス電極用複合樹脂を溶解して樹脂溶液を調製する際に用いられる溶媒がそのまま使用されることが多く、例えば、N-メチル-2-ピロリドン及びγ-ブチロラクトンが好ましい。これらの溶媒は、1種を単独で用いてもよく、2種以上を組み合わせて用いてもよい。
本開示のエネルギーデバイス電極形成用組成物には、電解液に対する耐膨潤性を補完するための架橋成分、電極の柔軟性及び可とう性を補完するためのゴム成分、スラリーの電極塗工性を向上させるための沈降防止剤、消泡剤、レベリング剤等の各種添加剤を必要に応じて配合することもできる。
塩基性物質の中和剤として炭酸ガスを用いることで、酸成分がエネルギーデバイス電極形成用組成物内に不純物として残存しにくい利点がある。
エネルギーデバイス電極形成用組成物に炭酸ガスを導入する際における炭酸ガスの圧力は、0.12MPa~100MPaであることが好ましく、0.2MPa~50MPaであることがより好ましく、0.3MPa~10MPaであることがさらに好ましい。加圧状態でエネルギーデバイス電極形成用組成物に炭酸ガスを溶存させると、エネルギーデバイス電極形成用組成物中の二酸化炭素、炭酸、炭酸イオン及び重炭酸イオンの濃度を高くすることができる。
エネルギーデバイス電極形成用組成物に炭酸ガスを溶存させて中和処理を実施した後、エネルギーデバイス電極形成用組成物中の余剰の炭酸ガスを除去してもよい。エネルギーデバイス電極形成用組成物中から余剰の炭酸ガスを除去するための方法としては特に限定されるものではない。例えば、エネルギーデバイス電極形成用組成物中にキャビテーション(局所沸騰)を生じさせて脱気するキャビテーション法を用いてもよい。
エネルギーデバイス電極形成用組成物を中和処理する場合、エネルギーデバイス電極形成用組成物は溶媒を含有していてもよい。炭酸ガスは水以外にN-メチル-2-ピロリドン等の溶媒にも溶解可能であることから、中和処理は、水、N-メチル-2-ピロリドン等を溶媒として含むエネルギーデバイス電極形成用組成物に特に有効である。
中和処理を実施されるエネルギーデバイス電極形成用組成物に含まれる特定金属酸化物は、洗浄処理されたものであっても洗浄処理されていないものであってもよい。
なお、粘度は回転式せん断粘度計を用いて、25℃、せん断速度1.0s-1で測定される。
本開示のエネルギーデバイス用正極(以下、単に正極と略すこともある)は、正極集電体と、前記正極集電体の少なくとも一方の表面上に設けられ、本開示のエネルギーデバイス電極形成用組成物を含む正極合剤層と、を有する。
圧延は、例えばロールプレス機を用いて行われる。正極合剤層のかさ密度は、例えば、2g/cm3~5g/cm3であることが好ましく、2.5g/cm3~4g/cm3であることがより好ましい。さらに、正極内の残留溶媒、吸着水の除去等のため、例えば、100℃~150℃で1時間~20時間真空乾燥してもよい。
シート及び箔の厚さは、特に限定されず、例えば、1μm~500μmであることが好ましく、2μm~100μmであることがより好ましく、5μm~50μmであることがさらに好ましい。
本開示のエネルギーデバイスは、本開示のエネルギーデバイス用正極を含む。
本開示のエネルギーデバイスとしては、リチウムイオン二次電池、電気二重層キャパシタ、太陽電池、燃料電池等が挙げられる。
本開示のエネルギーデバイス用正極と、エネルギーデバイス用負極と、電解液とを組み合わせることで、本開示のエネルギーデバイスの一例であるリチウムイオン二次電池を得ることができる。
本開示のエネルギーデバイスは、非水電解液系のエネルギーデバイスに適用されることが好ましい。非水電解液系のエネルギーデバイスとは、水以外の溶媒を含む電解液を用いる蓄電又は発電デバイス(装置)をいう。
リチウムイオン二次電池は、例えば、エネルギーデバイス用正極と、エネルギーデバイス用負極と、エネルギーデバイス用正極とエネルギーデバイス用負極との間に介在するセパレータと、電解液と、を備える。エネルギーデバイス用正極として、本開示のエネルギーデバイス用正極が用いられる。
エネルギーデバイス用負極(以下、単に負極と略すこともある)は、負極集電体と、負極集電体の少なくとも一方の表面上に設けられた負極合剤層とを有するものである。負極合剤層は、負極活物質とバインダ樹脂と必要に応じて導電性材料とを有するものである。
これらの中でも、負極活物質としては、炭素材料が好ましい。炭素材料としては、天然黒鉛(鱗片状黒鉛等)、人造黒鉛等の黒鉛、アセチレンブラック、ケッチェンブラック、チャンネルブラック、ファーネスブラック、ランプブラック、サーマルブラック等のカーボンブラック、非晶質炭素、炭素繊維などが挙げられる。
炭素材料の平均粒子径は、0.1μm~60μmであることが好ましく、0.3μm~45μmであることがより好ましく、0.5μm~30μmであることがさらに好ましい。
また、炭素材料のBET比表面積は、1m2/g~10m2/gであることが好ましい。
炭素材料の中でも特に、リチウムイオン二次電池の放電容量をより向上できる観点からは、X線広角回折法における炭素六角平面の間隔(d002)が3.35Å~3.40Åであり、c軸方向の結晶子(Lc)が100Å以上である黒鉛が好ましい。
一方、炭素材料の中でも特に、サイクル特性及び安全性をより向上できる観点からは、X線広角回折法における炭素六角平面の間隔(d002)が3.50Å~3.95Åである非晶質炭素が好ましい。
BET比表面積は、例えば、JIS Z 8830:2013に準じて窒素吸着能から測定することができる。評価装置としては、例えば、QUANTACHROME社製:AUTOSORB-1(商品名)を用いることができる。試料表面及び構造中に吸着している水分がガス吸着能に影響を及ぼすと考えられることから、BET比表面積の測定を行う際には、まず加熱による水分除去の前処理を行うことが好ましい。
前処理では、0.05gの測定試料を投入した測定用セルを、真空ポンプで10Pa以下に減圧した後、110℃で加熱し、3時間以上保持した後、減圧した状態を保ったまま常温(25℃)まで自然冷却する。この前処理を行った後、評価温度を77Kとし、評価圧力範囲を相対圧(飽和蒸気圧に対する平衡圧力)にて1未満として測定する。
炭素材料の002面の面間隔d002は、X線(CuKα線)を試料に照射し、回折線をゴニオメーターにより測定し得た回折プロファイルより、回折角2θが24°~26°付近に現れる炭素002面に対応する回折ピークより、ブラッグの式を用いて算出することができる。
圧延は、例えばロールプレス機を用いて行われる。負極合剤層のかさ密度は、例えば、1g/cm3~2g/cm3であることが好ましく、1.2g/cm3~1.8g/cm3であることがより好ましく、1.4g/cm3~1.6g/cm3であることがさらに好ましい。さらに、負極内の残留溶媒、吸着水の除去等のため、例えば、100℃~150℃で1時間~20時間真空乾燥してもよい。
セパレータは、正極及び負極間を電子的には絶縁しつつもイオン透過性を有し、かつ、正極側における酸化性及び負極側における還元性に対する耐性を備えるものであれば特に制限はない。このような特性を満たすセパレータの材料(材質)としては、樹脂、無機物等が用いられる。
薄膜形状の基材としては、平均孔径が0.01μm~1μmであり、平均厚さが5μm~50μmのものが好適に用いられる。また、繊維形状又は粒子形状の上記無機物を、樹脂等の結着剤を用いて複合多孔層としたものをセパレータとして用いることができる。さらに、この複合多孔層を、正極又は負極の表面に形成し、セパレータとしてもよい。あるいは、この複合多孔層を他のセパレータの表面に形成し、多層セパレータとしてもよい。例えば、90%径(D90)が1μm未満のアルミナ粒子を、結着剤としてフッ素樹脂を用いて結着させた複合多孔層を正極の表面に形成したものを、セパレータとしてもよい。
電解液としては、例えば、エネルギーデバイスであるリチウムイオン二次電池としての機能を発揮させるものであれば特に制限はない。電解液としては、水以外の溶媒を含む電解液(非水電解液)を用いることが好ましい。非水電解液の具体例としては、プロピレンカーボネート、エチレンカーボネート、ブチレンカーボネート、ジメチルカーボネート、ジエチルカーボネート、メチルエチルカーボネート等のカーボネート類、γ-ブチロラクトン等のラクトン類、トリメトキシメタン、1,2-ジメトキシエタン、ジエチルエーテル、2-エトキシエタン、テトラヒドロフラン、2-メチルテトラヒドロフラン等のエーテル類、ジメチルスルホキシド等のスルホキシド類、1,3-ジオキソラン、4-メチル-1,3-ジオキソラン等のオキソラン類、アセトニトリル、ニトロメタン、N-メチル-2-ピロリドン等の含窒素化合物類、ギ酸メチル、酢酸メチル、酢酸ブチル、プロピオン酸メチル、プロピオン酸エチル、リン酸トリエステル等のエステル類、ジグライム、トリグライム、テトラグライム等のグライム類、アセトン、ジエチルケトン、メチルエチルケトン、メチルイソブチルケトン等のケトン類、スルホラン等のスルホン類、3-メチル-2-オキサゾリジノン等のオキサゾリジノン類、1,3-プロパンスルトン、4-ブタンスルトン、ナフタスルトン等のスルトン類などの有機溶媒に、LiClO4、LiBF4、LiI、LiPF6、LiCF3SO3、LiCF3CO2、LiAsF6、LiSbF6、LiAlCl4、LiCl、LiBr、LiB(C2H5)4、LiCH3SO3、LiC4F9SO3、Li(CF3SO2)2N、Li[(CO2)2]2B等の電解質を溶解した溶液などが挙げられる。これらの中では、カーボネート類にLiPF6を溶解した電解液が好ましい。
電解液は、例えば有機溶媒と電解質とを、それぞれ1種を単独で又は2種以上組み合わせて用いることで調製される。
撹拌機、温度計及び冷却管を装着した0.5リットルのセパラブルフラスコ内に、精製水(和光純薬工業株式会社製)397.2gを加えた後、系内を窒素置換し、72.0℃まで昇温した。系内の水温が72.0℃になっていることを確認後、精製水2.5gに重合開始剤の過硫酸アンモニウム(和光純薬工業株式会社製)347.0mgを溶解した溶液を系内に加えた後、250回転/分で撹拌した。次いで、系内にモノマー(ニトリル基含有単量体のアクリロニトリル(和光純薬工業株式会社製)41.4g(0.78モル)及びメトキシトリエチレングリコールアクリレート(新中村化学工業株式会社製、NKエステルAM-30G)1.4g(0.006モル))を2時間かけて滴下し、1時間かけて反応させた。次いで、精製水7.8gに重合開始剤の過硫酸アンモニウム(和光純薬工業株式会社製)420mgを溶解した溶液を系内に加えた後、1時間反応させた。次いで、系内の温度を92.0℃まで昇温し、1時間かけて反応させた。次いで、精製水1.5gに重合開始剤の過硫酸アンモニウム(和光純薬工業株式会社製)210mgを溶解した溶液を系内に加えた後、1時間反応させた。上記工程中は、系内を窒素雰囲気で保ち、250回転/分で撹拌を続けた。室温(25℃)に冷却後、反応液を吸引ろ過し、析出した樹脂をろ別した。ろ別した樹脂を精製水(和光純薬工業株式会社製)1000gで洗浄した。洗浄した樹脂を60℃、150Paに設定した真空乾燥機で24時間乾燥して、ニトリル基含有単量体由来の構造単位を含む樹脂(樹脂1)を得た。以下、ニトリル基含有単量体由来の構造単位を含む樹脂をPAN系樹脂と記載する。撹拌機、温度計及び冷却管を装着した0.5リットルのセパラブルフラスコ内に、NMP423gを加え、100±5℃に昇温した後、PAN系樹脂(樹脂1)の粉末27gを加え、300回転/分で5時間撹拌し、PAN系樹脂(樹脂1)のNMP溶液とした。
メトキシトリエチレングリコールアクリレートを、2-メトキシエチルアクリレート1.4g(0.011モル)に替えた以外は「ニトリル基含有単量体由来の構造単位を含む樹脂(樹脂1)の調製」と同様にして、ニトリル基含有単量体由来の構造単位を含む樹脂(樹脂2)及びそのNMP溶液を得た。
メトキシトリエチレングリコールアクリレートを、メトキシポリ(n=9)エチレングリコールアクリレート(新中村化学工業株式会社製、商品名:NKエステルAM-90G)1.4g(0.003モル)に替えた以外は「ニトリル基含有単量体由来の構造単位を含む樹脂(樹脂1)の調製」と同様にして、ニトリル基含有単量体由来の構造単位を含む樹脂(樹脂3)及びそのNMP溶液を得た。
(1)正極活物質Aの作製
炭酸リチウム1390gを純水に懸濁させた後、金属塩溶液を1.6L/時間で投入した。金属塩溶液は、ニッケル、コバルト及びアルミニウムの硝酸塩の水和物を用いて調製した。正極活物質Aとして得られる化合物がLiNi0.8Co0.15Al0.05O2となるように、金属塩溶液に含まれるニッケル、コバルト及びアルミニウムの比率を、Ni:Co:Al=80モル%:15モル%:5モル%の組成比に調整した。
金属塩溶液は、ニッケル、コバルト及びマンガンの硝酸塩の水和物を用いて調製した。正極活物質Bとして得られる化合物がLiNi0.8Co0.1Mn0.1O2となるように、金属塩溶液に含まれるニッケル、コバルト及びマンガンの比率を、Ni:Co:Mn=80モル%:10モル%:10モル%の組成比に調整した以外は、正極活物質Aと同様の方法で正極活物質Bを得た。以下、正極活物質BをNMC(811)と記載する。
得られたNMC(811)100g及び純水1000mlをビーカーに入れ、30分間撹拌した後、ろ過し固形物を得た。得られた固形物を同様の操作で2回洗浄した後、固形分を200℃にて12時間乾燥させ、正極活物質Cを得た。以下、正極活物質CをNMC(811)Wと記載する。
得られたNCA100g及び純水1000mlをビーカーに入れ、30分間撹拌した後、ろ過し固形物を得た。得られた固形物を同様の操作で2回洗浄した後、固形分を200℃にて12時間乾燥させ、正極活物質Dを得た。以下、正極活物質DをNCA(W)と記載する。
(実施例1)
NCA(正極活物質)とアセチレンブラック(導電性材料、デンカ株式会社製、デンカブラック HS-100)とPAN系樹脂(樹脂1)(ニトリル基含有単量体由来の構造単位を含む樹脂)とPVDF(フッ素樹脂)を固形分の比率が98.0質量%:1.0質量%:0.8質量%:0.2質量%となるよう混合し、さらに粘度調整のためにNMPを加えて正極スラリーを作製した。NMPは、E型粘度計(東機産業株式会社製、TV-35)を用いて、25℃、0.5回転/分の条件で測定したスラリーの粘度が2000mPa・s~5000mPa・sとなる量を加えた。
正極スラリーを作製した際の室温及び湿度は、25±1℃で55±1%RHであった。
NCAとアセチレンブラックとPAN系樹脂とPVDFを固形分比率が98.0質量%:1.0質量%:0.7質量%:0.3質量%とした以外は実施例1と同様の方法で正極スラリーを作製した。
NCAとアセチレンブラックとPAN系樹脂とPVDFを固形分比率が98.0質量%:1.0質量%:0.6質量%:0.4質量%とした以外は実施例1と同様の方法で正極スラリーを作製した。
NCAとアセチレンブラックとPAN系樹脂とPVDFを固形分比率が98.0質量%:1.0質量%:0.5質量%:0.5質量%とした以外は実施例1と同様の方法で正極スラリーを作製した。
正極活物質をNMC(811)とした以外は、実施例1と同様の方法で正極スラリーを作製した。
正極活物質をNMC(811)とした以外は、実施例2と同様の方法で正極スラリーを作製した。
正極活物質をNMC(811)とした以外は、実施例3と同様の方法で正極スラリーを作製した。
正極活物質をNMC(811)とした以外は、実施例4と同様の方法で正極スラリーを作製した。
PAN系樹脂(樹脂1)に替えてPAN系樹脂(樹脂2)を用いた以外は実施例1~実施例8と同様にして、正極スラリーを作製した。
PAN系樹脂(樹脂1)に替えてPAN系樹脂(樹脂3)を用いた以外は実施例1~実施例8と同様にして、正極スラリーを作製した。
NMC(811)W(正極活物質)とアセチレンブラック(導電性材料、デンカ株式会社製、デンカブラック HS-100)とPAN系樹脂(樹脂1)(ニトリル基含有単量体由来の構造単位を含む樹脂)とPVDF(フッ素樹脂)を固形分の比率が98.0質量%:1.0質量%:0.15質量%:0.85質量%となるよう混合し、さらに粘度調整のためにNMPを加えて正極スラリーを作製した。NMPは、E型粘度計(東機産業株式会社製、TV-35)を用いて、25℃、0.5回転/分の条件で測定したスラリーの粘度が2000mPa・s~5000mPa・sとなる量を加えた。
正極スラリーを作製した際の室温及び湿度は、25±1℃で55±1%RHであった。
正極活物質をNCA(W)とした以外は、実施例25と同様の方法で正極スラリーを作製した。
NCAとアセチレンブラックとPAN系樹脂(樹脂1)とPVDFを固形分比率が98.0質量%:1.0質量%:1.0質量%:0質量%とした以外は実施例1と同様の方法で正極スラリーを作製した。
NCAとアセチレンブラックとPAN系樹脂(樹脂1)とPVDFを固形分比率が98.0質量%:1.0質量%:0質量%:1.0質量%とした以外は実施例1と同様の方法で正極スラリーを作製した。
正極活物質をNMC(811)とした以外は、比較例1と同様の方法で正極スラリーを作製した。
正極活物質をNMC(811)とした以外は、比較例2と同様の方法で正極スラリーを作製した。
(1)正極スラリーのゲル化有無
作製した正極スラリーのゲル化有無は、正極スラリーの粘度及び希釈の可否で判定した。作製した正極スラリーの粘度をE型粘度計(東機産業株式会社製、TV-35)を用いて、25℃、0.5回転/分の条件で測定した。正極スラリーの粘度が5000mPa・sよりも高く、また、NMPでの希釈が困難な正極スラリーをゲル化有と判定した。
作製した正極スラリー20gをガラス製のサンプル管瓶(アズワン株式会社製、30cc)に入れ密閉した状態で、25±1℃の環境下において実質的に水平な台に静置し、作製1日後のスラリーの外観を観察した。スラリーが上澄みと沈殿物とに分離したスラリーは沈降ありと判断した。沈降の起きたスラリーは安定性が低いと判定した。
作製した正極スラリー20gをガラス製のサンプル管瓶(アズワン株式会社製、30cc)に入れ、密閉した状態で、25±1℃の環境下において実質的に水平な台に静置し、作製1日後の粘度をE型粘度計(東機産業株式会社製、TV-35)を用いて、25℃、0.5回転/分の条件で測定した。粘度の変化率を下式により算出し、以下の基準で正極スラリーの粘度安定性を評価した。
粘度変化率(%)=[(静置後粘度-静置前粘度)/静置後粘度] × 100
A:粘度変化率が-20%以上100%未満
B:粘度変化率が-40%以上-20%未満又は100%以上200%未満
C:粘度変化率が-60%以上-40%未満又は200%以上300%未満
D:粘度変化率が-60%未満又は300%以上
以上の結果から、本開示によれば、正極活物質として、特定金属酸化物を含む正極活物質を用いる場合において、正極スラリーのゲル化及び沈降が抑制できるエネルギーデバイス電極用複合樹脂を提供できることが示唆された。
本明細書に記載された全ての文献、特許出願、及び技術規格は、個々の文献、特許出願、及び技術規格が参照により取り込まれることが具体的かつ個々に記された場合と同程度に、本明細書中に参照により取り込まれる。
Claims (14)
- ニトリル基含有単量体由来の構造単位を含む樹脂及びフッ素樹脂を含有するエネルギーデバイス電極用複合樹脂。
- リチウムとニッケルとを有しリチウムを除く金属に占めるニッケルの割合が50モル%以上であるリチウム含有金属複合酸化物を含む正極活物質を含有する正極合剤層の形成に用いられる請求項1に記載のエネルギーデバイス電極用複合樹脂。
- 前記リチウム含有金属複合酸化物が、下記式(I)で表される化合物を含む請求項2に記載のエネルギーデバイス電極用複合樹脂。
LiaNibCocMdO2+e 式(I)
(式(I)中、Mは、Al、Mn、Mg及びCaからなる群より選択される少なくとも1種であり、a、b、c、d及びeは、各々0.2≦a≦1.2であり、0.5≦b≦0.9であり、0.05≦c≦0.4であり、0≦d≦0.2であり、-0.2≦e≦0.2であり、b+c+d=1である。) - 前記ニトリル基含有単量体由来の構造単位を含む樹脂に含有される前記ニトリル基含有単量体由来の構造単位1モルに対する前記式(II)で表される単量体由来の構造単位の比率が、0.001モル~0.2モルである請求項4に記載のエネルギーデバイス電極用複合樹脂。
- 前記ニトリル基含有単量体由来の構造単位を含む樹脂に含有される前記ニトリル基含有単量体由来の構造単位1モルに対する前記式(III)で表される単量体由来の構造単位の比率が、0.001モル~0.2モルである請求項6に記載のエネルギーデバイス電極用複合樹脂。
- 前記ニトリル基含有単量体が、アクリロニトリルを含む請求項1~請求項7のいずれか1項に記載のエネルギーデバイス電極用複合樹脂。
- 前記フッ素樹脂が、ポリフッ化ビニリデン(PVDF)を含む請求項1~請求項8のいずれか1項に記載のエネルギーデバイス電極用複合樹脂。
- リチウムとニッケルとを有しリチウムを除く金属に占めるニッケルの割合が50モル%以上であるリチウム含有金属複合酸化物を含む正極活物質と、請求項1~請求項9のいずれか1項に記載のエネルギーデバイス電極用複合樹脂と、を含有するエネルギーデバイス電極形成用組成物。
- 前記リチウム含有金属複合酸化物が、下記式(I)で表される化合物を含む請求項10に記載のエネルギーデバイス電極形成用組成物。
LiaNibCocMdO2+e 式(I)
(式(I)中、Mは、Al、Mn、Mg及びCaからなる群より選択される少なくとも1種であり、a、b、c、d及びeは、各々0.2≦a≦1.2であり、0.5≦b≦0.9であり、0.05≦c≦0.4であり、0≦d≦0.2であり、-0.2≦e≦0.2であり、b+c+d=1である。) - 正極集電体と、
前記正極集電体の少なくとも一方の表面上に設けられ、請求項10又は請求項11に記載のエネルギーデバイス電極形成用組成物を含む正極合剤層と、
を有するエネルギーデバイス用正極。 - 請求項12に記載のエネルギーデバイス用正極を含むエネルギーデバイス。
- 前記エネルギーデバイスが、リチウムイオン二次電池である請求項13に記載のエネルギーデバイス。
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201880014040.8A CN110326140B (zh) | 2017-02-27 | 2018-02-27 | 能量装置电极用复合树脂、能量装置电极形成用组合物、能量装置用正极以及能量装置 |
JP2019501875A JP6988879B2 (ja) | 2017-02-27 | 2018-02-27 | エネルギーデバイス電極用樹脂混合物、エネルギーデバイス電極形成用組成物、エネルギーデバイス用正極及びエネルギーデバイス |
US16/488,335 US20200235397A1 (en) | 2017-02-27 | 2018-02-27 | Composite resin for energy device electrode, composition for forming energy device electrode, positive electrode for energy device, and energy device |
EP18758204.4A EP3588638A4 (en) | 2017-02-27 | 2018-02-27 | COMPOSITE RESIN FOR ENERGY DEVICE ELECTRODE, COMPOSITION FOR FORMING AN ENERGY DEVICE ELECTRODE, POSITIVE ELECTRODE FOR ENERGY DEVICE, AND ENERGY DEVICE |
KR1020197024724A KR102381115B1 (ko) | 2017-02-27 | 2018-02-27 | 에너지 디바이스 전극용 복합 수지, 에너지 디바이스 전극 형성용 조성물, 에너지 디바이스용 정극 및 에너지 디바이스 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JPPCT/JP2017/007558 | 2017-02-27 | ||
PCT/JP2017/007558 WO2018154787A1 (ja) | 2017-02-27 | 2017-02-27 | エネルギーデバイス電極用複合樹脂、エネルギーデバイス電極形成用組成物、エネルギーデバイス用正極及びエネルギーデバイス |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2018155714A1 true WO2018155714A1 (ja) | 2018-08-30 |
Family
ID=63252545
Family Applications (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2017/007558 WO2018154787A1 (ja) | 2017-02-27 | 2017-02-27 | エネルギーデバイス電極用複合樹脂、エネルギーデバイス電極形成用組成物、エネルギーデバイス用正極及びエネルギーデバイス |
PCT/JP2018/007324 WO2018155715A1 (ja) | 2017-02-27 | 2018-02-27 | エネルギーデバイス電極形成用組成物、エネルギーデバイス用正極及びエネルギーデバイス |
PCT/JP2018/007323 WO2018155714A1 (ja) | 2017-02-27 | 2018-02-27 | エネルギーデバイス電極用複合樹脂、エネルギーデバイス電極形成用組成物、エネルギーデバイス用正極及びエネルギーデバイス |
Family Applications Before (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2017/007558 WO2018154787A1 (ja) | 2017-02-27 | 2017-02-27 | エネルギーデバイス電極用複合樹脂、エネルギーデバイス電極形成用組成物、エネルギーデバイス用正極及びエネルギーデバイス |
PCT/JP2018/007324 WO2018155715A1 (ja) | 2017-02-27 | 2018-02-27 | エネルギーデバイス電極形成用組成物、エネルギーデバイス用正極及びエネルギーデバイス |
Country Status (7)
Country | Link |
---|---|
US (1) | US20200235397A1 (ja) |
EP (1) | EP3588638A4 (ja) |
JP (1) | JP6988879B2 (ja) |
KR (1) | KR102381115B1 (ja) |
CN (1) | CN110326140B (ja) |
TW (2) | TWI785014B (ja) |
WO (3) | WO2018154787A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2023282248A1 (ja) * | 2021-07-06 | 2023-01-12 | 日産化学株式会社 | 電極形成用組成物 |
WO2023282246A1 (ja) * | 2021-07-06 | 2023-01-12 | 日産化学株式会社 | 電極形成用組成物 |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2018154786A1 (ja) * | 2017-02-27 | 2018-08-30 | 日立化成株式会社 | エネルギーデバイス電極用樹脂、エネルギーデバイス電極形成用組成物、エネルギーデバイス電極及びエネルギーデバイス |
WO2024203178A1 (ja) * | 2023-03-31 | 2024-10-03 | 富士フイルム株式会社 | 顔料分散物及びインク組成物 |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2006033173A1 (ja) * | 2004-09-22 | 2006-03-30 | Hitachi Chemical Company, Ltd. | 非水電解液系エネルギーデバイス電極用バインダ樹脂組成物、非水電解液系エネルギーデバイス電極及び非水電解液系エネルギーデバイス |
JP2008235147A (ja) | 2007-03-23 | 2008-10-02 | Sanyo Electric Co Ltd | 非水電解質二次電池 |
JP2008293719A (ja) * | 2007-05-23 | 2008-12-04 | Sony Corp | ゲル状電解質二次電池 |
JP2009117159A (ja) * | 2007-11-06 | 2009-05-28 | Sony Corp | 正極及びリチウムイオン二次電池 |
JP2010251280A (ja) * | 2009-03-23 | 2010-11-04 | Sanyo Electric Co Ltd | 非水電解質二次電池 |
JP2012028225A (ja) * | 2010-07-26 | 2012-02-09 | Hitachi Vehicle Energy Ltd | 非水電解質二次電池及び正極合剤の製造方法 |
JP4951823B2 (ja) | 2001-07-17 | 2012-06-13 | 住友金属鉱山株式会社 | 非水電解質二次電池用正極活物質の製造方法 |
WO2012114651A1 (ja) * | 2011-02-25 | 2012-08-30 | 株式会社豊田自動織機 | 硫黄変性ポリアクリロニトリルおよびその評価方法ならびに硫黄変性ポリアクリロニトリルを用いた正極、非水電解質二次電池、および車両 |
WO2014142281A1 (ja) * | 2013-03-15 | 2014-09-18 | 日産自動車株式会社 | 非水電解質二次電池用正極およびこれを用いた非水電解質二次電池 |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS4951823A (ja) | 1972-09-19 | 1974-05-20 | ||
JP4433509B2 (ja) * | 1999-04-15 | 2010-03-17 | 日本ゼオン株式会社 | リチウムイオン二次電池電極用バインダー組成物及びその利用 |
JP4311002B2 (ja) * | 2002-11-29 | 2009-08-12 | 日本ゼオン株式会社 | 電極用スラリー組成物、電極および二次電池 |
JP2007194202A (ja) * | 2005-12-20 | 2007-08-02 | Sony Corp | リチウムイオン二次電池 |
JP5412853B2 (ja) * | 2009-01-30 | 2014-02-12 | ダイキン工業株式会社 | リチウム二次電池の正極の製造方法および正極ならびにリチウム二次電池 |
KR101666877B1 (ko) * | 2011-10-12 | 2016-10-18 | 삼성에스디아이 주식회사 | 리튬 이차 전지 |
JP6048070B2 (ja) * | 2012-10-29 | 2016-12-21 | 日本ゼオン株式会社 | リチウムイオン二次電池負極用スラリー組成物及びその製造方法、リチウムイオン二次電池用負極、並びにリチウムイオン二次電池 |
US10056614B2 (en) * | 2013-09-26 | 2018-08-21 | Ube Industries, Ltd. | Polyimide binder for power storage device, electrode sheet using same, and power storage device |
CN107078276A (zh) * | 2014-10-27 | 2017-08-18 | 日立化成株式会社 | 锂离子电池 |
WO2016147857A1 (ja) * | 2015-03-18 | 2016-09-22 | 日立化成株式会社 | バインダ樹脂組成物、リチウムイオン二次電池用電極、及びリチウムイオン二次電池 |
JP2016213027A (ja) * | 2015-05-07 | 2016-12-15 | 日立化成株式会社 | 非水電解液系エネルギーデバイス電極用バインダ樹脂組成物、これを用いた非水電解液系エネルギーデバイス電極及び非水電解液系エネルギーデバイス |
KR20190000377A (ko) * | 2015-06-29 | 2019-01-02 | 니폰 제온 가부시키가이샤 | 2차 전지 전극용 바인더 조성물, 2차 전지 전극용 슬러리 조성물, 2차 전지용 전극 및 2차 전지 |
-
2017
- 2017-02-27 WO PCT/JP2017/007558 patent/WO2018154787A1/ja active Application Filing
-
2018
- 2018-02-27 TW TW107106672A patent/TWI785014B/zh active
- 2018-02-27 KR KR1020197024724A patent/KR102381115B1/ko active IP Right Grant
- 2018-02-27 WO PCT/JP2018/007324 patent/WO2018155715A1/ja active Application Filing
- 2018-02-27 WO PCT/JP2018/007323 patent/WO2018155714A1/ja unknown
- 2018-02-27 EP EP18758204.4A patent/EP3588638A4/en not_active Withdrawn
- 2018-02-27 TW TW107106667A patent/TW201842702A/zh unknown
- 2018-02-27 US US16/488,335 patent/US20200235397A1/en not_active Abandoned
- 2018-02-27 JP JP2019501875A patent/JP6988879B2/ja active Active
- 2018-02-27 CN CN201880014040.8A patent/CN110326140B/zh active Active
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4951823B2 (ja) | 2001-07-17 | 2012-06-13 | 住友金属鉱山株式会社 | 非水電解質二次電池用正極活物質の製造方法 |
WO2006033173A1 (ja) * | 2004-09-22 | 2006-03-30 | Hitachi Chemical Company, Ltd. | 非水電解液系エネルギーデバイス電極用バインダ樹脂組成物、非水電解液系エネルギーデバイス電極及び非水電解液系エネルギーデバイス |
JP2008235147A (ja) | 2007-03-23 | 2008-10-02 | Sanyo Electric Co Ltd | 非水電解質二次電池 |
JP2008293719A (ja) * | 2007-05-23 | 2008-12-04 | Sony Corp | ゲル状電解質二次電池 |
JP2009117159A (ja) * | 2007-11-06 | 2009-05-28 | Sony Corp | 正極及びリチウムイオン二次電池 |
JP2010251280A (ja) * | 2009-03-23 | 2010-11-04 | Sanyo Electric Co Ltd | 非水電解質二次電池 |
JP2012028225A (ja) * | 2010-07-26 | 2012-02-09 | Hitachi Vehicle Energy Ltd | 非水電解質二次電池及び正極合剤の製造方法 |
WO2012114651A1 (ja) * | 2011-02-25 | 2012-08-30 | 株式会社豊田自動織機 | 硫黄変性ポリアクリロニトリルおよびその評価方法ならびに硫黄変性ポリアクリロニトリルを用いた正極、非水電解質二次電池、および車両 |
WO2014142281A1 (ja) * | 2013-03-15 | 2014-09-18 | 日産自動車株式会社 | 非水電解質二次電池用正極およびこれを用いた非水電解質二次電池 |
Non-Patent Citations (2)
Title |
---|
"Various analyses of electrode binder", THE TRC NEWS, September 2013 (2013-09-01) |
See also references of EP3588638A4 |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2023282248A1 (ja) * | 2021-07-06 | 2023-01-12 | 日産化学株式会社 | 電極形成用組成物 |
WO2023282246A1 (ja) * | 2021-07-06 | 2023-01-12 | 日産化学株式会社 | 電極形成用組成物 |
Also Published As
Publication number | Publication date |
---|---|
KR102381115B1 (ko) | 2022-03-30 |
TW201838234A (zh) | 2018-10-16 |
TWI785014B (zh) | 2022-12-01 |
WO2018155715A1 (ja) | 2018-08-30 |
JP6988879B2 (ja) | 2022-01-05 |
JPWO2018155714A1 (ja) | 2019-12-26 |
EP3588638A1 (en) | 2020-01-01 |
US20200235397A1 (en) | 2020-07-23 |
KR20190103451A (ko) | 2019-09-04 |
EP3588638A4 (en) | 2021-01-13 |
TW201842702A (zh) | 2018-12-01 |
WO2018154787A1 (ja) | 2018-08-30 |
CN110326140B (zh) | 2023-01-13 |
CN110326140A (zh) | 2019-10-11 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
KR100935986B1 (ko) | 비수전해액계 에너지장치 전극용 바인더 수지 조성물, 비수전해액계 에너지장치 전극 및 비수전해액계 에너지장치 | |
KR102381115B1 (ko) | 에너지 디바이스 전극용 복합 수지, 에너지 디바이스 전극 형성용 조성물, 에너지 디바이스용 정극 및 에너지 디바이스 | |
JP2011134492A (ja) | 非水電解液系エネルギーデバイス電極用バインダ樹脂組成物、非水電解液系エネルギーデバイス電極及び非水電解液系エネルギーデバイス | |
JP6789498B2 (ja) | エネルギーデバイス電極形成用組成物、エネルギーデバイス用正極及びエネルギーデバイス | |
JP6908102B2 (ja) | エネルギーデバイス電極用樹脂、エネルギーデバイス電極形成用組成物、エネルギーデバイス電極及びエネルギーデバイス | |
JP2010174058A (ja) | ポリマー粒子及びこのポリマー粒子を用いた非水電解液エネルギーデバイス用バインダ樹脂組成物 | |
JP6885411B2 (ja) | エネルギーデバイス用電極及びエネルギーデバイス | |
JP2015003998A (ja) | アクリルポリマー粒子の製造方法及びそれにより得られるアクリルポリマー粒子 | |
JP7091602B2 (ja) | エネルギーデバイス用電極及びエネルギーデバイス | |
WO2018087897A1 (ja) | エネルギーデバイス電極用樹脂、エネルギーデバイス電極形成用組成物、エネルギーデバイス電極及びエネルギーデバイス |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 18758204 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2019501875 Country of ref document: JP Kind code of ref document: A |
|
ENP | Entry into the national phase |
Ref document number: 20197024724 Country of ref document: KR Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: 2018758204 Country of ref document: EP Effective date: 20190927 |