WO2021187407A1 - Composition for power storage device, slurry for power storage device electrode, power storage device electrode, and power storage device - Google Patents

Composition for power storage device, slurry for power storage device electrode, power storage device electrode, and power storage device Download PDF

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Publication number
WO2021187407A1
WO2021187407A1 PCT/JP2021/010328 JP2021010328W WO2021187407A1 WO 2021187407 A1 WO2021187407 A1 WO 2021187407A1 JP 2021010328 W JP2021010328 W JP 2021010328W WO 2021187407 A1 WO2021187407 A1 WO 2021187407A1
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Prior art keywords
storage device
power storage
mass
polymer
parts
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PCT/JP2021/010328
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French (fr)
Japanese (ja)
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香奈 増田
卓哉 中山
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Jsr株式会社
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Priority to JP2022508339A priority Critical patent/JPWO2021187407A1/ja
Publication of WO2021187407A1 publication Critical patent/WO2021187407A1/en

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F222/00—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; Salts, anhydrides, esters, amides, imides, or nitriles thereof
    • C08F222/36—Amides or imides
    • C08F222/38—Amides
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/134—Electrodes based on metals, Si or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • 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
    • H01M4/1395—Processes of manufacture of electrodes based on metals, Si or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • 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
    • 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 composition for a power storage device, a slurry for a power storage device electrode containing the composition, a power storage device electrode formed by applying and drying the slurry to a current collector, and a power storage device provided with the electrode. ..
  • Lithium-ion batteries, lithium-ion capacitors, and the like are expected as such power storage devices.
  • the electrodes used in such a power storage device are manufactured by applying a composition (slurry for electrodes) containing an active material and a polymer functioning as a binder to the surface of a current collector and drying it.
  • the properties required for the polymer used as a binder include the ability to bond the active materials to each other, the ability to adhere the active material to the current collector, the abrasion resistance in the process of winding the electrodes, and the subsequent cutting. Examples include powder drop resistance in which fine powder of the active material does not fall off from the coated / dried composition coating film (hereinafter, also referred to as “active material layer”).
  • an active material using such a material having a large amount of lithium occlusion is accompanied by a large volume change due to the occlusion and release of lithium.
  • a conventionally used electrode binder is applied to such a material having a large lithium occlusion, the active material cannot be maintained and the active material is peeled off, which is remarkable with charging and discharging. Capacity drop occurs.
  • Patent Documents 2 and 3 As a technique for improving the adhesion of the binder for the electrode, a technique for controlling the surface acid amount of the particulate binder particles (see Patent Documents 2 and 3) and a binder having an epoxy group or a hydroxy group are used. Therefore, techniques for improving the above characteristics (see Patent Document 4 and Patent Document 5) and the like have been proposed. Further, a technique has been proposed in which the active material is bound by the rigid molecular structure of polyimide to suppress the volume change of the active material (see Patent Document 6).
  • Japanese Unexamined Patent Publication No. 2004-185810 International Publication No. 2011/096463 International Publication No. 2013/191080
  • Japanese Unexamined Patent Publication No. 2010-205722 Japanese Unexamined Patent Publication No. 2010-3703 Japanese Unexamined Patent Publication No. 2011-204592
  • the binder for electrodes as disclosed in Patent Documents 1 to 6 is a new active material typified by a silicon material having a large amount of lithium occlusion and a large volume change due to occlusion and release of lithium. Adhesion was not sufficient for practical use. When such an electrode binder is used, the electrode deteriorates due to the active material falling off due to repeated charging and discharging, so that there is a problem that the durability required for practical use cannot be sufficiently obtained.
  • some aspects of the present invention provide a binder composition for a power storage device capable of producing a power storage device electrode which is excellent in flexibility and adhesion and exhibits good charge / discharge durability characteristics.
  • some aspects of the present invention provide a slurry for a power storage device electrode containing the composition.
  • some aspects of the present invention provide a power storage device electrode that is excellent in flexibility and adhesion and exhibits good charge / discharge durability characteristics. Further, some aspects of the present invention provide a power storage device having excellent charge / discharge durability characteristics.
  • the present invention has been made to solve at least a part of the above-mentioned problems, and can be realized as any of the following aspects.
  • One aspect of the composition for a power storage device is Containing the polymer (A) and the liquid medium (B),
  • the polymer (A) is:
  • the repeating unit (a1) derived from the compound having a cyclic carbonate group is 1 to 50 parts by mass.
  • At least one repeating unit selected from the group consisting of (a5) is 50 to 99 parts by mass. Contains.
  • the pH may be 5-11.
  • the viscosity of the 10% by mass aqueous solution of the polymer (A) at pH 9 may be 200,000 to 200,000 mPa ⁇ s.
  • the liquid medium (B) may be water.
  • One aspect of the slurry for power storage device electrodes according to the present invention is The composition for a power storage device according to any one of the above embodiments, At least one polymer (C) selected from the group consisting of a styrene-butadiene copolymer, an acrylic polymer, and a fluorine-based polymer, and Contains.
  • the polymer (A) may be contained in an amount of 5 to 100 parts by mass with respect to 100 parts by mass of the polymer (C).
  • the energy storage device electrode slurry may contain an active material.
  • a silicon material may be contained as the active material.
  • the energy storage device electrode slurry may contain a thickener.
  • One aspect of the power storage device electrode according to the present invention is A current collector and an active material layer formed by applying and drying a slurry for a power storage device electrode according to any one of the above on the surface of the current collector are provided.
  • One aspect of the power storage device according to the present invention is The storage device electrode of the above-described embodiment is provided.
  • composition for a power storage device since flexibility and adhesion can be improved, a power storage device electrode exhibiting good charge / discharge durability characteristics can be manufactured.
  • the composition for a power storage device according to the present invention exerts the above-mentioned effect particularly when the power storage device electrode contains a material having a large lithium occlusion as an active material, for example, a carbon material such as graphite or a silicon material.
  • a material having a large lithium occlusion can be used as the active material of the power storage device electrode, the battery performance is also improved.
  • (meth) acrylic acid- in the present specification is a concept that includes both “acrylic acid-” and “methacrylic acid-”.
  • -(meth) acrylate is a concept that includes both “-acrylate” and “-methacrylate”.
  • (meth) acrylamide is a concept that includes both “acrylamide” and “methacrylamide”.
  • composition for power storage device contains a polymer (A) and a liquid medium (B), and is a repeating unit contained in the polymer (A).
  • the polymer (A) has 1 to 50 parts by mass of a repeating unit (a1) derived from a compound having a cyclic carbonate group, and a repeating unit derived from an unsaturated carboxylic acid (a repeating unit (a1).
  • a2 a repeating unit derived from (meth) acrylamide (a3), a repeating unit derived from a compound having a sulfo group (a4), and a repeating unit derived from a compound having a hydroxyl group (a5). It contains at least one repeating unit of 50 to 99 parts by mass.
  • the composition for a power storage device according to the present embodiment is for producing a power storage device electrode (active material layer) having improved binding ability between active materials, adhesion ability between the active material and a current collector, and powder drop resistance. It can be used as a material, or it can be used as a material for forming a protective film for suppressing a short circuit caused by dendrites generated during charging and discharging.
  • a power storage device electrode active material layer
  • the composition for a power storage device electrode is for producing a power storage device electrode (active material layer) having improved binding ability between active materials, adhesion ability between the active material and a current collector, and powder drop resistance. It can be used as a material, or it can be used as a material for forming a protective film for suppressing a short circuit caused by dendrites generated during charging and discharging.
  • the composition for a power storage device contains a polymer (A).
  • the polymer (A) is a repeating unit (a1) derived from a compound having a cyclic carbonate group, assuming that the total of the repeating units contained in the polymer (A) is 100 parts by mass (hereinafter, simply “repeating unit”).
  • (A1) ”) is derived from 1 to 50 parts by mass, a repeating unit (a2) derived from an unsaturated carboxylic acid (hereinafter, also simply referred to as a“ repeating unit (a2) ”), and (meth) acrylamide.
  • Repeat unit (a3) (hereinafter, also simply referred to as “repeating unit (a3)"), repeating unit (a4) derived from a compound having a sulfo group (hereinafter, also simply referred to as “repeating unit (a4)”).
  • repeating unit (a5) derived from a compound having a hydroxyl group (hereinafter, also simply referred to as “repeating unit (a5)”) is 50 to 99 parts by mass. Contains.
  • the polymer (A) may contain a repeating unit derived from another monomer copolymerizable therewith, in addition to the repeating unit.
  • examples of other monomers include unsaturated carboxylic acid esters, conjugated diene compounds, aromatic vinyl compounds, ⁇ , ⁇ -unsaturated nitrile compounds, and cationic monomers.
  • the polymer (A) contained in the composition for a power storage device according to the present embodiment may be in the form of latex dispersed in the liquid medium (B), or may be in a state of being dissolved in the liquid medium (B). However, it is preferably in a state of being dissolved in the liquid medium (B).
  • the slurry for a power storage device hereinafter, also simply referred to as “slurry” produced by mixing with an active material or an inorganic filler is stable. It is preferable because the property is good and the property of the slurry to be applied to the current collector is good.
  • Repeating unit (a1) derived from a compound having a cyclic carbonate group The content ratio of the repeating unit (a1) derived from the compound having a cyclic carbonate group is 1 to 50 parts by mass when the total of the repeating units contained in the polymer (A) is 100 parts by mass.
  • the lower limit of the content ratio of the repeating unit (a1) is preferably 2 parts by mass, more preferably 5 parts by mass, further preferably 7 parts by mass, and particularly preferably 10 parts by mass. preferable.
  • the upper limit of the content ratio of the repeating unit (a1) is preferably 48 parts by mass, more preferably 45 parts by mass, and particularly preferably 40 parts by mass.
  • the active material can be coated with the polymer (A) having a cyclic carbonate group, and a good film is formed on the surface of the active material due to the decomposition of the cyclic carbonate group during charging. Since it is formed, decomposition of the electrolytic solution component can be suppressed, and depletion of the electrolytic solution can be prevented, the capacity retention rate when the charge / discharge cycle is carried out becomes good. Further, since the polymer (A) having a low glass transition temperature can exist in the state of an aqueous solution, the dispersibility of the active material and the filler becomes good. Further, since the polymer (A) becomes excellent in flexibility, it is possible to suppress the occurrence of structural defects of the electrode plate by expanding and contracting even if the polymer (A) coats the active material, and has good charge / discharge durability. Shows the characteristics.
  • the compound having a cyclic carbonate group is not particularly limited, and examples thereof include a compound represented by the following general formula (1) and a compound represented by the following general formula (2).
  • R 1 represents a hydrogen atom or a methyl group.
  • R 2 represents a single bond or a divalent linking group.
  • R 3 represents a monovalent organic group having a cyclic carbonate structure.
  • R 3 examples include groups represented by the following general formula (3) or the following general formula (4).
  • n1 represents an integer of 0 to 2
  • n2 to n5 independently represent an integer of 0 to 2
  • "*" represents the general formula (1).
  • it represents a bond that binds to R 2 in the above general formula (2).
  • the groups represented by the general formula (3) and the general formula (4) may have a substituent.
  • the compound represented by the following general formula (7) or the following general formula (8) is preferable.
  • R 1 represents a hydrogen atom or a methyl group.
  • the polymer (A) can contain a repeating unit (a2) derived from an unsaturated carboxylic acid.
  • the content ratio of the repeating unit (a2) derived from the unsaturated carboxylic acid is preferably 5 to 90 parts by mass when the total of the repeating units contained in the polymer (A) is 100 parts by mass.
  • the lower limit of the content ratio of the repeating unit (a2) is preferably 7 parts by mass, more preferably 10 parts by mass.
  • the upper limit of the content ratio of the repeating unit (a2) is preferably 85 parts by mass, more preferably 80 parts by mass.
  • the dispersibility of the active material and the filler becomes good. Further, it exhibits good charge / discharge durability characteristics by improving the affinity with the silicon material as an active material and suppressing the swelling of the silicon material.
  • the unsaturated carboxylic acid is not particularly limited, and examples thereof include mono- or dicarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid, and one or more selected from these. There can be.
  • the polymer (A) can contain a repeating unit (a3) derived from (meth) acrylamide.
  • the content ratio of the repeating unit (a3) derived from (meth) acrylamide is preferably 5 to 90 parts by mass when the total of the repeating units contained in the polymer (A) is 100 parts by mass.
  • the lower limit of the content ratio of the repeating unit (a3) is preferably 7 parts by mass, more preferably 10 parts by mass.
  • the upper limit of the content ratio of the repeating unit (a3) is preferably 85 parts by mass, more preferably 80 parts by mass.
  • the glass transition degree (Tg) of the polymer (A) becomes suitable, and as a result, the dispersibility of the active material and the filler becomes good.
  • the flexibility of the obtained active material layer becomes appropriate, and the adhesion ability between the current collector and the active material layer becomes good. Further, since the bonding ability between the active materials containing the carbon material such as graphite and the silicon material can be enhanced, the obtained active material layer has better flexibility and adhesion to the current collector. ..
  • the (meth) acrylamide is not particularly limited, but is limited to acrylamide, methacrylamide, N-isopropylacrylamide, N, N-dimethylacrylamide, N, N-dimethylmethacrylicamide, N, N-diethylacrylamide, N, N-diethylmethacryl.
  • Examples thereof include amide, N, N-dimethylaminopropyl acrylamide, N, N-dimethylaminopropyl methacrylamide, N-methylol methacrylamide, N-methylol acrylamide, diacetone acrylamide, maleic acid amide, acrylamide tert-butyl sulfonic acid and the like. ..
  • These (meth) acrylamides may be used alone or in combination of two or more.
  • Repeating unit (a4) derived from a compound having a sulfo group The polymer (A) can contain a repeating unit (a4) derived from a compound having a sulfo group.
  • the compound having a sulfo group has an ethylenically unsaturated group that contributes to the polymerization reaction, strictly speaking, it is a compound having an ethylenically unsaturated group and a sulfo group.
  • the content ratio of the repeating unit (a4) derived from the compound having a sulfo group is preferably 5 to 90 parts by mass when the total of the repeating units contained in the polymer (A) is 100 parts by mass. ..
  • the lower limit of the content ratio of the repeating unit (a4) is preferably 7 parts by mass, more preferably 10 parts by mass.
  • the upper limit of the content ratio of the repeating unit (a4) is preferably 85 parts by mass, more preferably 80 parts by mass.
  • the flexibility of the obtained active material layer becomes appropriate, and the adhesion ability between the current collector and the active material layer becomes good. Further, since the bonding ability between the active materials containing the carbon material such as graphite and the silicon material can be enhanced, the obtained active material layer has better flexibility and adhesion to the current collector. ..
  • the compound having a sulfo group are not particularly limited, but vinyl sulfonic acid, styrene sulfonic acid, allyl sulfonic acid, sulfoethyl (meth) acrylate, sulfopropyl (meth) acrylate, sulfobutyl (meth) acrylate, 2-acrylamide.
  • Compounds having a sulfonic acid group such as -2-methylpropanesulfonic acid, 2-hydroxy-3-acrylamidepropanesulfonic acid, 3-allyloxy-2-hydroxypropanesulfonic acid, and alkali salts thereof may be used.
  • Repeating unit (a5) derived from a compound having a hydroxyl group The polymer (A) can contain a repeating unit (a5) derived from a compound having a hydroxyl group.
  • the compound having a hydroxyl group has an ethylenically unsaturated group that contributes to the polymerization reaction, strictly speaking, it is a compound having an ethylenically unsaturated group and a hydroxyl group.
  • the content ratio of the repeating unit (a5) derived from the compound having a hydroxyl group is preferably 5 to 90 parts by mass when the total of the repeating units contained in the polymer (A) is 100 parts by mass.
  • the lower limit of the content ratio of the repeating unit (a5) is preferably 7 parts by mass, more preferably 10 parts by mass.
  • the upper limit of the content ratio of the repeating unit (a5) is preferably 85 parts by mass, more preferably 80 parts by mass.
  • the flexibility of the obtained active material layer becomes appropriate, and the adhesion ability between the current collector and the active material layer becomes good. Further, since the bonding ability between the active materials containing the carbon material such as graphite and the silicon material can be enhanced, the obtained active material layer has better flexibility and adhesion to the current collector. ..
  • the compound having a hydroxyl group are not particularly limited, but are 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate.
  • 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate 5-Hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, glycerin mono (meth) acrylate, glycerin di (meth) acrylate and other unsaturated carboxylic acid esters; vinyl alcohol, 2-vinylphenol, 3- Examples thereof include vinylphenol and 4-vinylphenol.
  • 2-hydroxyethyl (meth) acrylate and glycerin mono (meth) acrylate are preferable.
  • the polymer (A) has a repeating unit (a2) and a repeating unit (a2) when the total of the repeating units contained in the polymer (A) is 100 parts by mass. It contains 50 to 99 parts by mass of at least one repeating unit selected from the group consisting of a3), a repeating unit (a4) and a repeating unit (a5).
  • the lower limit of the content ratio of the repeating units (a2) to (a5) is preferably 55 parts by mass, more preferably 60 parts by mass.
  • the upper limit of the content ratio of the repeating units (a2) to (a5) is preferably 95 parts by mass, more preferably 90 parts by mass.
  • the glass transition temperature (Tg) of the polymer (A) becomes more suitable, and an electrode plate having excellent flexibility can be produced. As a result, an electrode plate having excellent charge / discharge durability characteristics can be obtained. Further, the affinity between the polymer (A) and the active material or filler becomes better, and a slurry having better dispersibility of the active material or filler can be obtained.
  • the polymer (A) may contain repeating units derived from other monomers copolymerizable with the repeating units (a1) to (a5) in addition to the repeating units (a1) to (a5).
  • a repeating unit is a repeating unit derived from an unsaturated carboxylic acid ester (excluding those corresponding to the repeating units (a1) to (a5).
  • it is also simply referred to as “repeating unit (a6)”).
  • the repeating unit (a7) derived from the conjugated diene compound hereinafter, also simply referred to as “repeating unit (a7)
  • the repeating unit (a8) derived from the aromatic vinyl compound (hereinafter, simply “repeating unit (a8)).
  • repeating unit (a9) derived from ⁇ , ⁇ -unsaturated nitrile compound (hereinafter, also simply referred to as“ repeating unit (a9) ”), repeating unit derived from cationic monomer (hereinafter, also referred to as“ repeating unit ”). , Simply referred to as “repeating unit (a10)”) and the like.
  • the unsaturated carboxylic acid ester is not particularly limited, but a (meth) acrylic acid ester is preferable.
  • Specific examples of the (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n-butyl (meth) acrylate.
  • methyl (meth) acrylate one or more selected from methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, cyclohexyl (meth) acrylate and 2-ethylhexyl (meth) acrylate. It is preferably present, and particularly preferably methyl (meth) acrylate.
  • the conjugated diene compound is not particularly limited, but 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-chlor-1,3-butadiene and the like can be used. It can be listed and can be one or more selected from these. Of these, 1,3-butadiene is particularly preferable.
  • the aromatic vinyl compound is not particularly limited, and examples thereof include styrene, ⁇ -methylstyrene, p-methylstyrene, vinyltoluene, chlorostyrene, and divinylbenzene, and one or more selected from these can be used. There can be. Of these, styrene is particularly preferable.
  • the ⁇ , ⁇ -unsaturated nitrile compound is not particularly limited, and examples thereof include acrylonitrile, methacrylonitrile, ⁇ -chloroacrylonitrile, ⁇ -ethylacrylonitrile, vinylidene cyanide, and the like, and are selected from these 1 Can be more than a seed. Of these, one or more selected from acrylonitrile and methacrylonitrile is preferable, and acrylonitrile is particularly preferable.
  • the cationic monomer is not particularly limited, but is at least one monomer selected from the group consisting of a secondary amine (salt), a tertiary amine (salt) and a quaternary ammonium salt. Is preferable. Specific examples of these cationic monomers are not particularly limited, but are 2- (dimethylamino) ethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate methyl quaternary chloride quaternary salt, and 2- (meth) acrylate.
  • the polymer (A) has a repeating unit (a6), a repeating unit (a7), a repeating unit (a8), and a repeating unit (a6), assuming that the total of the repeating units contained in the polymer (A) is 100 parts by mass. It is preferable to contain 20 parts by mass or less of a9) and the repeating unit (a10) in total.
  • the content ratio of the repeating units (a6) to (a10) is more preferably 0 to 15 parts by mass, and particularly preferably 0 to 10 parts by mass.
  • the polymer (A) is preferably a water-soluble polymer.
  • the "water-soluble polymer” in the present invention refers to a polymer having a solubility in water at 25 ° C. and 1 atm of 1 g or more with respect to 100 g of water.
  • the surface of the active material is easily coated by the polymer (A) having excellent flexibility and adhesion, so that the active material can be effectively removed by expansion and contraction during charging and discharging. It is easy to obtain a power storage device that can be effectively suppressed and exhibits good charge / discharge durability characteristics. Further, the stability of the slurry is improved, and the applicability of the slurry to the current collector is also improved, which is preferable.
  • the viscosity of the 10% by mass aqueous solution of the polymer (A) at pH 9 is preferably 20 to 200,000 mPa ⁇ s, more preferably 50 to 150,000 mPa ⁇ s, and 1,000 to 150, It is particularly preferably 000 mPa ⁇ s.
  • the viscosity of the 10% by mass aqueous solution of the polymer (A) at pH 9 is in the above range, the dispersibility of the active material and the filler becomes good, and a uniform active material layer and a protective film can be easily formed. As a result, an electrode or the like having no structural defects can be obtained, which is preferable because it exhibits good charge / discharge characteristics.
  • the viscosity of the 10% by mass aqueous solution of the polymer (A) is a value measured at a temperature of 25.0 ° C. using a B-type viscometer in accordance with JIS Z8803.
  • a B-type viscometer for example, "RB-80L” or “TVB-10” manufactured by Toki Sangyo Co., Ltd. can be used.
  • the number average molecular weight (Mn) of the polymer (A) is preferably 10,000 or more and 2,000,000 or less, more preferably 50,000 or more and 1,500,000 or less, and particularly preferably 100, It is 000 or more and 1,000,000 or less.
  • the number average molecular weight of the polymer (A) can be measured, for example, by using the GPC method under the following conditions.
  • the polymer (A) preferably has only one endothermic peak in the temperature range of 60 ° C. to 160 ° C. as measured by differential scanning calorimetry (DSC) according to JIS K 7121.
  • the temperature of this endothermic peak (that is, the glass transition temperature (Tg)) is more preferably in the range of 70 ° C. to 150 ° C.
  • the polymer (A) exhibits good adhesion and has good adhesion to the active material layer. It is preferable because it can impart better flexibility and adhesiveness.
  • the method for producing the polymer (A) is not particularly limited, but for example, polymerization performed in a solvent containing water as a main component in the presence of a known chain transfer agent, polymerization initiator, or the like can be performed. preferable.
  • the polymer (A) may be synthesized by one-step polymerization, two-step polymerization or multi-step polymerization, and a polymerization initiator, a molecular weight modifier, an emulsifier (surfactant) and the like known in each polymerization. Can be synthesized in the presence of.
  • the amount and type of the polymerization initiator As for the amount and type of the polymerization initiator, the molecular weight adjusting agent, the emulsifier (surfactant) and the like, and the synthesis method, the components and methods described in Japanese Patent No. 5477610 and the like can be used.
  • the pH may be adjusted to 5 to 11 by adding a neutralizing agent to the polymerization mixture obtained by the above synthesis method.
  • the neutralizing agent used here is not particularly limited, and examples thereof include metal hydroxides such as sodium hydroxide and potassium hydroxide; ammonia and the like.
  • the polymer (A) can be dissolved in the liquid medium (B) to thicken it. Further, by concentrating the polymerization mixture after the neutralization treatment, the solid content concentration can be increased while maintaining the good stability of the polymer (A).
  • a slurry for a power storage device is prepared using the composition for a power storage device as it is without adding a neutralizer to the polymerization mixture obtained by the above synthesis method, and then a neutralizer is added to the slurry for the power storage device. It may be added to increase the viscosity by adjusting the pH to 5-11. In this case, since the composition for the power storage device is not thickened, it may be easy to prepare the slurry for the power storage device.
  • the composition for a power storage device according to the present embodiment contains a liquid medium (B).
  • the liquid medium (B) is preferably an aqueous medium containing water, and more preferably water.
  • the aqueous medium may contain a non-aqueous medium other than water. Examples of this non-aqueous medium include amide compounds, hydrocarbons, alcohols, ketones, esters, amine compounds, lactones, sulfoxides, sulfone compounds, and the like, and one or more selected from these may be used. Can be done.
  • an aqueous medium as the liquid medium (B) in the composition for a power storage device according to the present embodiment, the degree of adverse effect on the environment is reduced, and the safety for the handling operator is also increased.
  • the content ratio of the non-aqueous medium contained in the aqueous medium is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and particularly preferably not substantially contained in 100 parts by mass of the aqueous medium. preferable.
  • substantially free means that a non-aqueous medium is not intentionally added as a liquid medium, and the non-aqueous medium is inevitably mixed when preparing a composition for a power storage device. May include.
  • composition for a power storage device may contain additives other than the above-mentioned components, if necessary.
  • additives include polymers other than the polymer (A), preservatives, thickeners and the like.
  • the composition for a power storage device may contain a polymer other than the polymer (A) (hereinafter, also referred to as “polymer (C)”).
  • a polymer (C) is not particularly limited, but is an acrylic polymer containing a styrene-butadiene copolymer such as SBR (styrene butadiene rubber), an unsaturated carboxylic acid ester or a derivative thereof as a constituent unit.
  • SBR styrene butadiene rubber
  • Fluorine-based polymers such as PVDF (polyvinylidene fluoride) and the like can be mentioned.
  • PVDF polyvinylidene fluoride
  • the content ratio of the polymer (A) in the composition for a power storage device according to the present embodiment is 1 to 70 parts by mass with respect to 100 parts by mass in total of the polymer (A), the polymer (C) and the thickener. It is preferably 1 to 40 parts by mass, and particularly preferably 2 to 10 parts by mass.
  • the content ratio of the polymer (A) is 5 to 100 parts by mass with respect to 100 parts by mass of the polymer (C). It is preferably 10 to 80 parts by mass, and particularly preferably 10 to 60 parts by mass.
  • flexibility and adhesion may be effectively improved, and the amount of lithium stored as an active material is particularly large.
  • a material such as a carbon material such as graphite or a silicon material is used, it may be possible to manufacture a power storage device electrode exhibiting good charge / discharge durability characteristics.
  • the composition for a power storage device may contain a preservative.
  • a preservative By containing the preservative, it may be possible to suppress the growth of bacteria, mold and the like to generate foreign substances when the composition for a power storage device is stored.
  • Specific examples of the preservative include compounds described in Japanese Patent No. 5477610.
  • the composition for a power storage device according to the present embodiment may contain a thickener. By containing the thickener, the coatability thereof and the charge / discharge characteristics of the obtained power storage device may be further improved.
  • the thickener include cellulose compounds such as carboxymethyl cellulose, methyl cellulose, and hydroxypropyl cellulose; poly (meth) acrylic acid; the cellulose compound or the ammonium salt or alkali metal salt of the poly (meth) acrylic acid; polyvinyl.
  • Polyvinyl alcohol-based (co) polymers such as alcohol, modified polyvinyl alcohol, and ethylene-vinyl alcohol copolymers; copolymers of unsaturated carboxylic acids such as (meth) acrylic acid, maleic acid, and fumaric acid and vinyl esters. Examples thereof include water-soluble polymers such as saponified products.
  • alkali metal salts of carboxymethyl cellulose, alkali metal salts of poly (meth) acrylic acid and the like are preferable.
  • the content ratio of the thickener shall be 5 parts by mass or less with respect to 100 parts by mass of the total solid content of the composition for a power storage device. Is preferable, and 0.1 to 3 parts by mass is more preferable.
  • the pH of the composition for a power storage device according to the present embodiment is preferably 5 to 11, more preferably 6 to 11, and particularly preferably 7 to 10.5.
  • the polymer (A) dissolves in the liquid medium (B), so that the viscosity of the composition for a power storage device can be increased.
  • PH in the present specification refers to physical properties measured as follows. It is a value measured in accordance with JIS Z8802: 2011 with a pH meter using a glass electrode calibrated with a neutral phosphate standard solution and a borate standard solution as a pH standard solution at 25 ° C. Examples of such a pH meter include “HM-7J” manufactured by DKK-TOA CORPORATION and "D-51” manufactured by HORIBA, Ltd.
  • the pH of the composition for a power storage device is affected by the monomer composition constituting the polymer (A), but it is not determined only by the monomer composition. That is, it is generally known that the pH of the composition for a power storage device changes depending on the polymerization conditions and the like even if the monomer composition is the same, and the examples of the present specification show only one example. No.
  • the polymer composition is the same, all the unsaturated carboxylic acids are charged into the polymerization reaction solution from the beginning, and then other monomers are added in sequence, or a monomer other than the unsaturated carboxylic acid is added.
  • the amount of carboxyl groups derived from the unsaturated carboxylic acid exposed on the surface of the obtained polymer is different from that in the case of charging the polymerization reaction solution and finally adding the unsaturated carboxylic acid. It is considered that the pH of the composition for a power storage device is significantly different even if the order in which the monomers are added is changed by the polymerization method.
  • the slurry for power storage device according to the embodiment of the present invention contains the above-mentioned composition for power storage device.
  • the composition for a power storage device according to the present embodiment can be used as a material for forming a protective film for suppressing a short circuit caused by dendrites generated during charging and discharging. It can also be used as a material for producing a power storage device electrode (active material layer) having improved binding ability between active materials, adhesion ability between the active material and a current collector, and powder drop resistance.
  • a slurry for a power storage device for forming a protective film (hereinafter, also referred to as a “slurry for forming a protective film”) and a slurry for a power storage device for forming an active material layer of a power storage device electrode (hereinafter, “storage”). It is also referred to as “device electrode slurry”).
  • Slurry for forming a protective film refers to a slurry for forming a protective film, which is applied to the surface of an electrode or a separator or both, and then dried to apply a protective film to the surface of an electrode or a separator or both.
  • the slurry for forming a protective film according to the present embodiment may be composed only of the above-mentioned composition for a power storage device, or may further contain an inorganic filler.
  • each component contained in the protective film forming slurry according to the present embodiment will be described in detail. Since the composition for the power storage device is as described above, the description thereof will be omitted.
  • the slurry for forming a protective film according to the present embodiment can improve the toughness of the protective film formed by containing the inorganic filler.
  • the inorganic filler it is preferable to use at least one kind of particles selected from the group consisting of silica, titanium oxide (titania), aluminum oxide (alumina), zirconium oxide (zirconia), and magnesium oxide (magnesia).
  • titanium oxide and aluminum oxide are preferable from the viewpoint of further improving the toughness of the protective film.
  • rutile type titanium oxide is more preferable.
  • the average particle size of the inorganic filler is preferably 1 ⁇ m or less, more preferably 0.1 to 0.8 ⁇ m.
  • the average particle size of the inorganic filler is preferably larger than the average pore size of the separator which is a porous film. This can reduce damage to the separator and prevent the inorganic filler from clogging the microporous separator.
  • the slurry for forming a protective film according to the present embodiment preferably contains 0.1 to 20 parts by mass of the above-mentioned composition for a power storage device in terms of solid content with respect to 100 parts by mass of the inorganic filler. More preferably, it is contained in an amount of about 10 parts by mass.
  • the content ratio of the composition for the power storage device is within the above range, the balance between the toughness of the protective film formed and the permeability of lithium ions is good, and as a result, the resistance increase rate of the obtained power storage device is lowered. can do.
  • the slurry for forming a protective film according to the present embodiment may further contain a liquid medium, and is described in the section "1.2. Liquid medium (B)" of the above-mentioned composition for a power storage device.
  • the material can be used as needed.
  • the amount of the liquid medium added can be adjusted as necessary so that the optimum viscosity of the slurry can be obtained according to the coating method and the like.
  • Slurry for power storage device electrodes The term "slurry for power storage device electrodes" as used herein is used to apply this to the surface of a current collector and then dry it to form an active material layer on the surface of the current collector. It refers to the dispersion liquid that is produced.
  • the slurry for a power storage device electrode according to the present embodiment contains the above-mentioned composition for a power storage device and an active material.
  • a slurry for a power storage device electrode often contains a binder component such as an SBR-based copolymer and a thickener such as carboxymethyl cellulose in order to improve adhesion.
  • the slurry for the power storage device electrode according to the present embodiment can improve the flexibility and the adhesiveness only by the above-mentioned polymer (A).
  • the slurry for the power storage device electrode according to the present embodiment may contain a polymer other than the polymer (A) or a thickener in order to further improve the adhesion.
  • the composition, properties, and production method of the polymer (A) are as described above, and thus the description thereof will be omitted.
  • the content ratio of the polymer (A) in the slurry for the power storage device electrode according to the present embodiment is preferably 1 to 8 parts by mass and 1 to 7 parts by mass with respect to 100 parts by mass of the active material. It is more preferably 1.5 to 6 parts by mass, and particularly preferably 1.5 to 6 parts by mass.
  • the content ratio of the polymer (A) is within the above range, the dispersibility of the active material in the slurry becomes good, and the coatability of the slurry becomes also excellent.
  • the slurry for the power storage device electrode according to the present embodiment contains a polymer other than the polymer (A) or a thickener.
  • active material used in the slurry for the power storage device electrode according to the present embodiment include a carbon material, a silicon material, an oxide containing a lithium atom, a lead compound, a tin compound, an arsenic compound, an antimony compound, and an aluminum compound. Can be mentioned. Specific examples of these include compounds described in Japanese Patent No. 5999399.
  • the active material layer may contain the active material exemplified below.
  • active material conductive polymers such as polyacene; A X B Y O Z (where, A is an alkali metal or a transition metal, B is cobalt, nickel, aluminum, tin, at least one selected from the transition metals manganese, O Represents an oxygen atom, where X, Y and Z are numbers in the range 1.10>X> 0.05, 4.00>Y> 0.85 and 5.00>Z> 1.5, respectively.)
  • Examples thereof include composite metal oxides represented by and other metal oxides.
  • the slurry for the power storage device electrode according to the present embodiment can be used when producing any power storage device electrode of the positive electrode and the negative electrode, and is preferably used for both the positive electrode and the negative electrode.
  • Lithium iron phosphate has a fine primary particle size and is known to be a secondary aggregate thereof. When charging and discharging are repeated, the aggregation collapses in the active material layer and the active materials are separated from each other. It is considered that one of the causes is that it is easily peeled off from the current collector and the conductive network inside the active material layer is easily broken.
  • the power storage device electrode produced by using the slurry for the power storage device electrode according to the present embodiment exhibits good electrical characteristics without causing the above-mentioned problems even when lithium iron phosphate is used. be able to.
  • the reason for this is that the polymer (A) can firmly bind lithium iron phosphate, and at the same time, it can maintain a state in which lithium iron phosphate is firmly bound even during charging and discharging. it is conceivable that.
  • the active material exemplified above contains a silicon material. Since the silicon material has a large occlusion amount of lithium per unit weight as compared with other active materials, the storage capacity of the obtained power storage device can be increased by containing the silicon material as the negative electrode active material. As a result, the output and energy density of the power storage device can be increased.
  • the negative electrode active material is more preferably a mixture of a silicon material and a carbon material. Since the volume change of the carbon material due to charge and discharge is small, the influence of the volume change of the silicon material can be mitigated by using a mixture of the silicon material and the carbon material as the negative electrode active material, and the active material layer and the collection. The ability to adhere to the electric body can be further improved.
  • silicon When silicon (Si) is used as an active material, silicon has a high capacity, but causes a large volume change when it occludes lithium. For this reason, the silicon material has a property that the conductive network inside the active material layer is easily broken by causing micronization, peeling from the current collector, and peeling between the active materials by repeating expansion and contraction. As a result, the cycle characteristics are extremely deteriorated in a short time.
  • the power storage device electrode produced by using the slurry for the power storage device electrode according to the present embodiment can exhibit good electrical characteristics without causing the above-mentioned problems even when a silicon material is used. can.
  • the reason for this is that the polymer (A) can firmly bind the silicon material, and at the same time, the polymer (A) expands and contracts even if the silicon material expands in volume due to occlusion of lithium, resulting in silicon. It is considered that this is because the material can be maintained in a tightly bound state.
  • the content ratio of the silicon material in 100% by mass of the active material is preferably 1% by mass or more, more preferably 1 to 50% by mass, further preferably 5 to 45% by mass, and 10%. It is particularly preferable to set it to 40% by mass.
  • the content ratio of the silicon material in 100% by mass of the active material is within the above range, a power storage device having an excellent balance between the improvement of the output and energy density of the power storage device and the charge / discharge durability characteristics can be obtained.
  • the shape of the active material is preferably granular.
  • the average particle size of the active material is preferably 0.1 to 100 ⁇ m, more preferably 1 to 20 ⁇ m.
  • the average particle size of the active material is a volume average particle size calculated from the particle size distribution measured by using a particle size distribution measuring device based on a laser diffraction method. Examples of such a laser diffraction type particle size distribution measuring device include the HORIBA LA-300 series and the HORIBA LA-920 series (all manufactured by HORIBA, Ltd.).
  • the liquid medium that can be additionally added to the slurry for the power storage device electrode according to the present embodiment may be the same as or different from the liquid medium (B) contained in the composition for the power storage device. It is preferable to select and use the liquid medium exemplified in the above section "1.2. Liquid medium (B)".
  • the ratio of the liquid medium (including the amount brought in from the composition for the power storage device) in the slurry for the power storage device electrode according to the present embodiment is the solid content concentration in the slurry (the total mass of the components other than the liquid medium in the slurry). Refers to the ratio of the slurry to the total mass. The same shall apply hereinafter) is preferably a ratio of 30 to 70% by mass, and more preferably 40 to 60% by mass.
  • the slurry for a power storage device electrode according to the present embodiment may contain a pH adjuster and / or a corrosion inhibitor for the purpose of suppressing corrosion of the current collector according to the type of active material.
  • pH adjuster examples include hydrochloric acid, phosphoric acid, sulfuric acid, acetic acid, formic acid, ammonium phosphate, ammonium sulfate, ammonium acetate, ammonium formate, ammonium chloride, sodium hydroxide, potassium hydroxide and the like. Sulfate, ammonium sulfate, sodium hydroxide and potassium hydroxide are preferred. Further, it can be selected and used from the compounds described in the method for producing the polymer (A).
  • Corrosion inhibitors include ammonium metavanadate, sodium metavanadate, potassium metavanadate, ammonium metatungstate, sodium metatungstate, potassium metatungstate, ammonium paratungstate, sodium paratungstate, potassium paratungstate, molybdate. Examples thereof include ammonium, sodium molybdate, and potassium molybdate. Among these, ammonium paratungstate, ammonium metavanadate, sodium metavanadate, potassium metavanadate, and ammonium molybdate are preferable.
  • the slurry for power storage device electrode according to the present embodiment is produced by any method as long as it contains the above-mentioned composition for power storage device and an active material. However, it can be produced by the method described in, for example, Japanese Patent No. 5999399.
  • the power storage device electrode according to an embodiment of the present invention includes a current collector, an active material layer formed by applying and drying the above-mentioned storage device electrode slurry on the surface of the current collector. Is provided. Such a power storage device electrode is formed by applying the above-mentioned slurry for a power storage device electrode to the surface of a current collector such as a metal foil to form a coating film, and then drying the coating film to form an active material layer. Can be manufactured.
  • the power storage device electrode produced in this manner is formed by bonding an active material layer containing the above-mentioned polymer (A), an active material, and an optional component added as needed, on a current collector. Therefore, it is excellent in flexibility and adhesion, and exhibits good charge / discharge durability characteristics.
  • the current collector is not particularly limited as long as it is made of a conductive material, and examples thereof include the current collector described in Japanese Patent No. 5999399.
  • the slurry for the power storage device electrode there is no particular limitation on the method of applying the slurry for the power storage device electrode to the current collector, and the slurry can be applied by the method described in, for example, Japanese Patent No. 5999399.
  • the power storage device electrode manufactured in this manner is excellent in flexibility and adhesion, and exhibits good charge / discharge durability characteristics.
  • the content ratio of the silicon element in 100 parts by mass of the active material layer is preferably 2 to 30 parts by mass, and 3 to 25 parts by mass. Is more preferable.
  • the content of the silicon element in the active material layer is within the above range, in addition to improving the storage capacity of the power storage device produced by using the silicon element, an active material layer having a uniform distribution of silicon elements can be obtained. ..
  • the content of the silicon element in the active material layer can be measured by, for example, the method described in Japanese Patent No. 5999399.
  • the power storage device according to the embodiment of the present invention can be manufactured according to a conventional method by providing the above-mentioned power storage device electrode, further containing an electrolytic solution, and using parts such as a separator.
  • a specific manufacturing method for example, a negative electrode and a positive electrode are overlapped with each other via a separator, and the negative electrode and the positive electrode are stored in a battery container by winding or folding according to the shape of the battery, and an electrolytic solution is injected into the battery container.
  • the method of sealing the battery can be mentioned.
  • the shape of the battery can be an appropriate shape such as a coin type, a cylindrical type, a square type, or a laminated type.
  • the electrolytic solution may be in the form of a liquid or a gel, and depending on the type of the active material, a known electrolytic solution used in the power storage device that effectively exhibits the function as a battery may be selected.
  • the electrolytic solution can be a solution in which the electrolyte is dissolved in a suitable solvent. Examples of these electrolytes and solvents include compounds described in Japanese Patent No. 5999399.
  • Example 1 5.1.1. Preparation of composition for power storage device and measurement of viscosity (1) Preparation of composition for power storage device In a 100 L autoclave, 900 parts by mass of water, 0.1 part by mass of sodium persulfate, 0.5 part by mass of dodecylbenzene sulfonic acid, 4- 5 parts by mass of vinyl-1,3-dioxolan-2-one, 20 parts by mass of acrylic acid, 32 parts by mass of acrylamide, and 43 parts by mass of methacrylicamide were added, and the reaction was carried out at 70 ° C. for 18 hours. Then, it was cooled and adjusted to pH 7.0 using a 5 wt% sodium hydroxide aqueous solution.
  • the residual monomer was removed by steam distillation and concentrated under reduced pressure to obtain a composition for a storage device having a pH of 7.0 containing 10% by mass of the polymer (A1).
  • the pH was adjusted by dropping a 5 wt% sodium hydroxide aqueous solution while measuring the pH at 25 ° C. using a pH meter (manufactured by HORIBA, Ltd.).
  • a stirring defoaming machine manufactured by Shinky Co., Ltd., trade name "Awatori Rentaro" was used at 200 rpm for 2 minutes. , 1,800 rpm for 5 minutes, and further under reduced pressure (about 2.5 ⁇ 10 4 Pa) at 1,800 rpm for 1.5 minutes to prepare a slurry for a positive electrode.
  • This positive electrode slurry was uniformly applied to the surface of the current collector made of aluminum foil by the doctor blade method so that the film thickness after removing the solvent was 150 ⁇ m, and heated at 120 ° C. for 20 minutes to remove the solvent. ..
  • a counter electrode positive electrode was obtained by press working with a roll press machine so that the density of the active material layer was 3.0 g / cm 3.
  • a Ni tab is welded to a glove box made by punching and molding the negative electrode manufactured above to 50 mm ⁇ 25 mm, and 56 mm. It was placed on a sheet made of polypropylene of ⁇ 32 mm. Next, a separator made of a polypropylene porous film punched to 55 mm ⁇ 30 mm (manufactured by Cellguard Co., Ltd., trade name “Cellguard # 2400”) was placed, and the positive electrode manufactured above was punched to 48 mm ⁇ 23 mm and then manufactured by Al.
  • a welded tab was placed, and a polypropylene sheet of 56 mm ⁇ 32 mm was further placed.
  • the structure is fixed by sticking 2 mm ⁇ 5 mm Kapton tape on the top and bottom of the long side portion of the structure, sandwiched between two 6 cm ⁇ 11 cm laminated films so as to be in the center, and three sides at 180 ° C. Was heat-sealed with a width of 1 cm. Then, after injecting 650 ⁇ L of the electrolytic solution, the remaining one side was vacuum-sealed to assemble a lithium ion battery cell (storage device).
  • Capacity retention rate (%) (Discharge capacity in the 100th cycle) / (Discharge capacity in the 1st cycle) (Evaluation criteria) ⁇ 5 points: Capacity retention rate is 90% or more. -4 points: Capacity retention rate is 88% or more and less than 90%. -3 points: Capacity retention rate is 86% or more and less than 88%. -2 points: Capacity retention rate is 84% or more and less than 86%. -1 point: Capacity retention rate is 82% or more and less than 84%. -0 points: Capacity retention rate is less than 82%.
  • “1C” indicates a current value at which a cell having a certain electric capacity is discharged with a constant current and the discharge is completed in 1 hour.
  • “0.1C” is a current value at which the discharge is completed over 10 hours
  • “10C” is a current value at which the discharge is completed over 0.1 hours.
  • a contact sensor manufactured by KEYENCE, product name "GT2-H12KLF" was attached to the power storage device, and the film thickness at that time was taken as the film thickness after chemical conversion. Then, charging is started at a constant current (0.2C), and when the voltage reaches 4.2V, charging is continued at a constant voltage (4.2V), and when the current value reaches 0.01C. Was considered to be fully charged (cutoff). After that, discharging is started at a constant current (0.2C) in a constant temperature bath adjusted to 25 ° C., and when the voltage reaches 2.5V, the discharging is completed (cutoff), and at the time of discharging in the 10th cycle.
  • the electrode plate expansion coefficient was calculated by the following formula and evaluated according to the following criteria. The evaluation results are shown in Table 2 below.
  • Plate expansion coefficient (%) ((film thickness at 10th cycle discharge)-(film thickness after chemical conversion) / (initial film thickness)) ⁇ 100 (Evaluation criteria)
  • ⁇ 5 points The coefficient of expansion of the electrode plate is 28% or less.
  • ⁇ 4 points The coefficient of expansion of the electrode plate is more than 28% to 30% or less.
  • ⁇ 3 points The coefficient of expansion of the electrode plate is more than 30% to 32% or less.
  • -2 points The coefficient of expansion of the electrode plate is more than 32% to 34% or less.
  • ⁇ 1 point The coefficient of expansion of the electrode plate exceeds 34%.
  • composition for power storage device (1) Preparation of composition for power storage device", the types and amounts of each monomer are as shown in Table 1 below. A composition for each power storage device containing 10% by mass of the polymer was obtained in the same manner except for the above. Further, the viscosity and number average molecular weight of the composition for a power storage device thus obtained were measured in the same manner as in Example 1 above.
  • the polymer (A) obtained in Example * is referred to as "polymer (A *)”
  • polymer (B) the polymer obtained in Comparative Example * is referred to as "polymer (B)”. *) ”. That is, * corresponds to the number of the example or the comparative example.
  • the slurry for the power storage device electrode was prepared in the same manner as in Example 1 above except that the polymer composition of the slurry for the power storage device electrode was changed as shown in Table 2 below, and the power storage device electrode and the power storage device were respectively prepared. Then, it was evaluated in the same manner as in Example 1 above.
  • Example 2 5.3.1. Synthesis of Acrylic Polymer 150 parts by mass of water and 0.2 parts by mass of sodium dodecylbenzenesulfonate were placed in a separable flask having a capacity of 7 liters, and the inside of the separable flask was sufficiently replaced with nitrogen. On the other hand, in another container, 60 parts by mass of water and an ether sulfate type emulsifier (trade name "Adecaria Soap SR1025", manufactured by ADEKA Co., Ltd.) as an emulsifier were added to 0.8 parts by mass in terms of solid content as a monomer.
  • an ether sulfate type emulsifier trade name "Adecaria Soap SR1025", manufactured by ADEKA Co., Ltd.
  • BA butyl acrylate
  • CHMA cyclohexyl methacrylate
  • AN acrylonitrile
  • MMA methyl methacrylate
  • EHA 2-ethylhexyl acrylate
  • AA acid
  • composition for power storage device In the above "5.1.1. Preparation and evaluation of composition for power storage device (1) Preparation of composition for power storage device", the type and amount of each monomer are determined. A composition for a power storage device having a pH of 10.0 containing 10% by mass of the polymer (A2) was obtained in the same manner except as shown in Table 1 below. Further, the viscosity and number average molecular weight of the composition for a power storage device thus obtained were measured in the same manner as in Example 1 above.
  • Example 5 Comparative Example 2
  • the polymer was prepared in the same manner except that the type and amount of each monomer were as shown in Table 1 below. A composition for each power storage device containing mass% was obtained. Further, the viscosity and number average molecular weight of the composition for a power storage device thus obtained were measured in the same manner as in Example 1 above.
  • the slurry for the power storage device electrode was prepared in the same manner as in Example 2 above except that the polymer composition of the slurry for the power storage device electrode was changed as shown in Table 2 below, and the power storage device electrode and the power storage device were respectively prepared. Then, it was evaluated in the same manner as in Example 2 above.
  • Example 3 5.5.1. Synthesis of Fluorine-Containing Acrylic Polymer After sufficiently replacing the inside of an autoclave with an internal volume of about 6 L equipped with an electromagnetic stirrer with nitrogen, 2.5 L of deoxygenated pure water and 25 g of ammonium perfluorodecanoate as an emulsifier are charged. , The temperature was raised to 60 ° C. with stirring at 350 rpm. Next, a mixed gas composed of 70% vinylidene fluoride (VDF) and 30% propylene hexafluoride (HFP), which are monomers, was charged until the internal pressure reached 20 kg / cm 2.
  • VDF 70% vinylidene fluoride
  • HFP propylene hexafluoride
  • the aqueous dispersion containing the fine particles of the polymer F obtained above was added to the aqueous dispersion having 25 parts by mass in terms of polymer F in terms of polymer F, and the emulsifier "Adecaria Soap SR1025".
  • MMA methyl methacrylate
  • EHA 2-ethylhexyl acrylate
  • MAA methacrylic acid
  • composition for power storage device In the above "5.1.1. Preparation and evaluation of composition for power storage device (1) Preparation of composition for power storage device", the type and amount of each monomer are determined. A composition for a power storage device having a pH of 5.0 containing 10% by mass of the polymer (A3) was obtained in the same manner except as shown in Table 1 below. Further, the viscosity and number average molecular weight of the composition for a power storage device thus obtained were measured in the same manner as in Example 1 above.
  • Example 5 Manufacture and Evaluation of Power Storage Device Electrodes and power storage devices were produced in the same manner as in Example 1 except that the slurry for power storage device electrodes prepared above was used, and evaluated in the same manner as in Example 1.
  • Example 6 Comparative Example 3
  • the polymer components were similarly prepared in the same manner except that the types and amounts of each monomer were as shown in Table 1 below.
  • a composition for each power storage device containing 10% by mass was obtained. Further, the viscosity of the composition for a power storage device thus obtained was measured in the same manner as in Example 1 above.
  • the slurry for the power storage device electrode was prepared in the same manner as in Example 3 above except that the polymer composition of the slurry for the power storage device electrode was changed as shown in Table 2 below, and the power storage device electrode and the power storage device were respectively prepared. Then, it was evaluated in the same manner as in Example 3 above.
  • Table 1 shows the composition and physical property values of the polymers used in Examples 1 to 10 and Comparative Examples 1 to 5.
  • Table 2 shows the polymer composition and each evaluation result of the slurry for power storage device electrodes used in Examples 1 to 10 and Comparative Examples 1 to 6.
  • the slurry for the electricity storage device electrode prepared by using the composition for the electricity storage device according to the present invention shown in Examples 1 to 10 is the case of Comparative Examples 1 to 6. It was found that the active materials having a large volume change due to charging and discharging can be suitably bonded to each other, and the adhesion between the active material layer and the current collector can be maintained well. As a result, even if the active material repeatedly expands and contracts in volume by repeating charging and discharging, a power storage device electrode capable of effectively suppressing peeling of the active material layer and maintaining good charging and discharging characteristics was obtained. ..
  • the power storage device (lithium ion secondary battery) provided with these power storage device electrodes also has good charge / discharge rate characteristics.
  • the reason for this is that the energy storage device electrodes according to Examples 1 to 10 shown in Table 1 have a film of an active material layer due to charge and discharge, as compared with the cases of Comparative Examples 1 to 6, based on the evaluation results of the electrode plate expansion coefficient. It is presumed that the change in thickness can be reduced and the conductive network inside the active material layer can be maintained.
  • the power storage device (lithium ion secondary battery) provided with these power storage device electrodes also has a good capacity retention rate when the charge / discharge cycle is carried out.
  • the present invention is not limited to the above embodiment, and various modifications are possible.
  • the present invention includes substantially the same configurations as those described in the embodiments (eg, configurations with the same function, method and result, or configurations with the same purpose and effect).
  • the present invention also includes a configuration in which a non-essential part of the configuration described in the above embodiment is replaced with another configuration.
  • the present invention also includes a configuration that exhibits the same effects as the configuration described in the above embodiment or a configuration that can achieve the same object.
  • the present invention also includes a configuration in which a known technique is added to the configuration described in the above embodiment.

Abstract

Provided is a composition for a power storage device which has excellent flexibility and adhesion and from which a power storage device electrode exhibiting good charge-and-discharge durability characteristics can be produced.　A composition for a power storage device according to the present invention contains a polymer (A) and a liquid medium (B), wherein when the total amount of repeating units contained in the polymer (A) is 100 parts by mass, the polymer (A) contains: 1-50 parts by mass of a repeating unit (a1) derived from a compound having a cyclic carbonate group; and 50-99 parts by mass of at least one repeating unit selected from the group consisting of a repeating unit (a2) derived from an unsaturated carboxylic acid, a repeating unit (a3) derived from a (meth)acrylamide, a repeating unit (a4) derived from a compound having a sulfo group, and a repeating unit (a5) derived from a compound having a hydroxyl group.

Description

蓄電デバイス用組成物、蓄電デバイス電極用スラリー、蓄電デバイス電極、及び蓄電デバイスComposition for power storage device, slurry for power storage device electrode, power storage device electrode, and power storage device
　本発明は、蓄電デバイス用組成物、該組成物を含有する蓄電デバイス電極用スラリー、該スラリーを集電体に塗布及び乾燥させて形成された蓄電デバイス電極、並びに該電極を備えた蓄電デバイスに関する。 The present invention relates to a composition for a power storage device, a slurry for a power storage device electrode containing the composition, a power storage device electrode formed by applying and drying the slurry to a current collector, and a power storage device provided with the electrode. ..
　近年、電子機器の駆動用電源として、高電圧かつ高エネルギー密度を有する蓄電デバイスが要求されている。このような蓄電デバイスとしては、リチウムイオン電池やリチウムイオンキャパシタなどが期待されている。 In recent years, a power storage device having a high voltage and a high energy density has been required as a power source for driving an electronic device. Lithium-ion batteries, lithium-ion capacitors, and the like are expected as such power storage devices.
　このような蓄電デバイスに使用される電極は、活物質と、バインダーとして機能する重合体とを含有する組成物（電極用スラリー）を集電体の表面へ塗布及び乾燥させることにより製造される。バインダーとして使用される重合体に要求される特性としては、活物質同士の結合能力及び活物質と集電体との密着能力、電極を巻き取る工程における耐擦性、その後の裁断などによっても、塗布・乾燥された組成物塗膜（以下、「活物質層」ともいう。）から活物質の微粉などが脱落しない粉落ち耐性などを挙げることができる。 The electrodes used in such a power storage device are manufactured by applying a composition (slurry for electrodes) containing an active material and a polymer functioning as a binder to the surface of a current collector and drying it. The properties required for the polymer used as a binder include the ability to bond the active materials to each other, the ability to adhere the active material to the current collector, the abrasion resistance in the process of winding the electrodes, and the subsequent cutting. Examples include powder drop resistance in which fine powder of the active material does not fall off from the coated / dried composition coating film (hereinafter, also referred to as “active material layer”).
　なお、上記の活物質同士の結合能力及び活物質と集電体との密着能力、並びに粉落ち耐性については、性能の良否がほぼ比例関係にあることが経験上明らかになっている。従って、本明細書では、以下これらを包括して「密着性」という用語を用いて表す場合がある。 It has been empirically clarified from experience that the quality of the performance is almost proportional to the binding ability between the active materials, the adhesion ability between the active material and the current collector, and the resistance to powder dropping. Therefore, in the present specification, these may be comprehensively expressed by using the term “adhesion”.
　近年、蓄電デバイスの更なる高出力化及び高エネルギー密度化を達成する観点から、リチウム吸蔵量の大きい材料を活物質として利用する検討が進められている。例えば、特許文献１に開示されているようにリチウムの理論吸蔵量が最大で約４，２００ｍＡｈ／ｇであるケイ素材料を活物質として活用する手法が有望視されている。 In recent years, from the viewpoint of achieving higher output and higher energy density of power storage devices, studies on using a material having a large lithium occlusion as an active material have been promoted. For example, as disclosed in Patent Document 1, a method of utilizing a silicon material having a maximum theoretical occlusion of lithium of about 4,200 mAh / g as an active material is promising.
　しかしながら、このようなリチウム吸蔵量の大きい材料を利用した活物質は、リチウムの吸蔵・放出により大きな体積変化を伴う。このため、従来使用されている電極用バインダーを、このようなリチウム吸蔵量の大きい材料に適用すると、密着性を維持することができずに活物質が剥離するなどし、充放電に伴って顕著な容量低下が発生する。 However, an active material using such a material having a large amount of lithium occlusion is accompanied by a large volume change due to the occlusion and release of lithium. For this reason, when a conventionally used electrode binder is applied to such a material having a large lithium occlusion, the active material cannot be maintained and the active material is peeled off, which is remarkable with charging and discharging. Capacity drop occurs.
　電極用バインダーの密着性を改良するための技術としては、粒子状のバインダー粒子の表面酸量を制御する技術（特許文献２及び特許文献３参照）や、エポキシ基やヒドロキシ基を有するバインダーを用いて上記特性を向上させる技術（特許文献４及び特許文献５参照）などが提案されている。また、ポリイミドの剛直な分子構造で活物質を束縛し、活物質の体積変化を押さえ込もうとする技術（特許文献６参照）が提案されている。 As a technique for improving the adhesion of the binder for the electrode, a technique for controlling the surface acid amount of the particulate binder particles (see Patent Documents 2 and 3) and a binder having an epoxy group or a hydroxy group are used. Therefore, techniques for improving the above characteristics (see Patent Document 4 and Patent Document 5) and the like have been proposed. Further, a technique has been proposed in which the active material is bound by the rigid molecular structure of polyimide to suppress the volume change of the active material (see Patent Document 6).
特開２００４－１８５８１０号公報Japanese Unexamined Patent Publication No. 2004-185810 国際公開第２０１１／０９６４６３号International Publication No. 2011/096463 国際公開第２０１３／１９１０８０号International Publication No. 2013/191080 特開２０１０－２０５７２２号公報Japanese Unexamined Patent Publication No. 2010-205722 特開２０１０－３７０３号公報Japanese Unexamined Patent Publication No. 2010-3703 特開２０１１－２０４５９２号公報Japanese Unexamined Patent Publication No. 2011-204592
　しかしながら、上記特許文献１～６に開示されているような電極用バインダーは、リチウム吸蔵量が大きく、かつ、リチウムの吸蔵・放出に伴う体積変化が大きいケイ素材料に代表される新たな活物質を実用化するにあたり密着性が十分とは言えなかった。このような電極用バインダーを使用すると、充放電を繰り返すことにより活物質が脱落するなどして電極が劣化するため、実用化に必要な耐久性が十分に得られないという課題があった。 However, the binder for electrodes as disclosed in Patent Documents 1 to 6 is a new active material typified by a silicon material having a large amount of lithium occlusion and a large volume change due to occlusion and release of lithium. Adhesion was not sufficient for practical use. When such an electrode binder is used, the electrode deteriorates due to the active material falling off due to repeated charging and discharging, so that there is a problem that the durability required for practical use cannot be sufficiently obtained.
　そこで、本発明に係る幾つかの態様は、柔軟性及び密着性に優れるとともに、良好な充放電耐久特性を示す蓄電デバイス電極を製造可能な蓄電デバイス用バインダー組成物を提供する。また、本発明に係る幾つかの態様は、該組成物を含有する蓄電デバイス電極用スラリーを提供する。また、本発明に係る幾つかの態様は、柔軟性及び密着性に優れるとともに、良好な充放電耐久特性を示す蓄電デバイス電極を提供する。さらに、本発明に係る幾つかの態様は、充放電耐久特性に優れる蓄電デバイスを提供する。 Therefore, some aspects of the present invention provide a binder composition for a power storage device capable of producing a power storage device electrode which is excellent in flexibility and adhesion and exhibits good charge / discharge durability characteristics. In addition, some aspects of the present invention provide a slurry for a power storage device electrode containing the composition. In addition, some aspects of the present invention provide a power storage device electrode that is excellent in flexibility and adhesion and exhibits good charge / discharge durability characteristics. Further, some aspects of the present invention provide a power storage device having excellent charge / discharge durability characteristics.
　本発明は上述の課題の少なくとも一部を解決するためになされたものであり、以下のいずれかの態様として実現することができる。 The present invention has been made to solve at least a part of the above-mentioned problems, and can be realized as any of the following aspects.
　本発明に係る蓄電デバイス用組成物の一態様は、
　重合体（Ａ）と、液状媒体（Ｂ）と、を含有し、
　前記重合体（Ａ）中に含まれる繰り返し単位の合計を１００質量部としたときに、前記重合体（Ａ）が、
　環状カーボネート基を有する化合物に由来する繰り返し単位（ａ１）を１～５０質量部と、
　不飽和カルボン酸に由来する繰り返し単位（ａ２）、（メタ）アクリルアミドに由来する繰り返し単位（ａ３）、スルホ基を有する化合物に由来する繰り返し単位（ａ４）、及び水酸基を有する化合物に由来する繰り返し単位（ａ５）からなる群より選択される少なくとも１種の繰り返し単位を５０～９９質量部と、
を含有する。 One aspect of the composition for a power storage device according to the present invention is
Containing the polymer (A) and the liquid medium (B),
When the total of the repeating units contained in the polymer (A) is 100 parts by mass, the polymer (A) is:
The repeating unit (a1) derived from the compound having a cyclic carbonate group is 1 to 50 parts by mass.
A repeating unit derived from an unsaturated carboxylic acid (a2), a repeating unit derived from (meth) acrylamide (a3), a repeating unit derived from a compound having a sulfo group (a4), and a repeating unit derived from a compound having a hydroxyl group. At least one repeating unit selected from the group consisting of (a5) is 50 to 99 parts by mass.
Contains.
　前記蓄電デバイス用組成物の一態様において、
　ｐＨが５～１１であってもよい。 In one aspect of the composition for a power storage device,
The pH may be 5-11.
　前記蓄電デバイス用組成物のいずれかの態様において、
　前記重合体（Ａ）の１０質量％水溶液の、ｐＨ９における粘度が、２０～２００，０００ｍＰａ・ｓであってもよい。 In any of the above-mentioned compositions for power storage devices,
The viscosity of the 10% by mass aqueous solution of the polymer (A) at pH 9 may be 200,000 to 200,000 mPa · s.
　前記蓄電デバイス用組成物のいずれかの態様において、
　前記液状媒体（Ｂ）が水であってもよい。 In any of the above-mentioned compositions for power storage devices,
The liquid medium (B) may be water.
　本発明に係る蓄電デバイス電極用スラリーの一態様は、
　前記いずれかの態様の蓄電デバイス用組成物と、
　スチレン－ブタジエン共重合体、アクリル系重合体及びフッ素系重合体からなる群より選択される少なくとも１種の重合体（Ｃ）と、
を含有する。 One aspect of the slurry for power storage device electrodes according to the present invention is
The composition for a power storage device according to any one of the above embodiments,
At least one polymer (C) selected from the group consisting of a styrene-butadiene copolymer, an acrylic polymer, and a fluorine-based polymer, and
Contains.
　前記蓄電デバイス電極用スラリーの一態様において、
　前記重合体（Ｃ）１００質量部に対し、前記重合体（Ａ）を５～１００質量部含有してもよい。 In one aspect of the storage device electrode slurry,
The polymer (A) may be contained in an amount of 5 to 100 parts by mass with respect to 100 parts by mass of the polymer (C).
　前記蓄電デバイス電極用スラリーのいずれかの態様において、
　さらに、活物質を含有してもよい。 In any aspect of the energy storage device electrode slurry,
In addition, it may contain an active material.
　前記蓄電デバイス電極用スラリーのいずれかの態様において、
　前記活物質としてケイ素材料を含有してもよい。 In any aspect of the energy storage device electrode slurry,
A silicon material may be contained as the active material.
　前記蓄電デバイス電極用スラリーのいずれかの態様において、
　さらに、増粘剤を含有してもよい。 In any aspect of the energy storage device electrode slurry,
In addition, it may contain a thickener.
　本発明に係る蓄電デバイス電極の一態様は、
　集電体と、前記集電体の表面上に前記いずれかの態様の蓄電デバイス電極用スラリーが塗布及び乾燥されて形成された活物質層と、を備える。 One aspect of the power storage device electrode according to the present invention is
A current collector and an active material layer formed by applying and drying a slurry for a power storage device electrode according to any one of the above on the surface of the current collector are provided.
　本発明に係る蓄電デバイスの一態様は、
　前記態様の蓄電デバイス電極を備える。 One aspect of the power storage device according to the present invention is
The storage device electrode of the above-described embodiment is provided.
　本発明に係る蓄電デバイス用組成物によれば、柔軟性及び密着性を向上できるため、良好な充放電耐久特性を示す蓄電デバイス電極を製造することができる。本発明に係る蓄電デバイス用組成物は、蓄電デバイス電極が活物質としてリチウム吸蔵量の大きい材料、例えばグラファイトのような炭素材料やケイ素材料を含有する場合に特に上記の効果を発揮する。このように、蓄電デバイス電極の活物質としてリチウム吸蔵量の大きい材料を使用できるので、電池性能も向上する。 According to the composition for a power storage device according to the present invention, since flexibility and adhesion can be improved, a power storage device electrode exhibiting good charge / discharge durability characteristics can be manufactured. The composition for a power storage device according to the present invention exerts the above-mentioned effect particularly when the power storage device electrode contains a material having a large lithium occlusion as an active material, for example, a carbon material such as graphite or a silicon material. As described above, since a material having a large lithium occlusion can be used as the active material of the power storage device electrode, the battery performance is also improved.
　以下、本発明に係る好適な実施形態について詳細に説明する。なお、本発明は、下記に記載された実施形態のみに限定されるものではなく、本発明の要旨を変更しない範囲において実施される各種の変形例も含むものとして理解されるべきである。 Hereinafter, preferred embodiments according to the present invention will be described in detail. It should be noted that the present invention is not limited to the embodiments described below, but should be understood to include various modifications implemented without changing the gist of the present invention.
　なお、本明細書における「（メタ）アクリル酸～」とは、「アクリル酸～」及び「メタクリル酸～」の双方を包括する概念である。同様に「～（メタ）アクリレート」とは、「～アクリレート」及び「～メタクリレート」の双方を包括する概念である。同様に「（メタ）アクリルアミド」とは、「アクリルアミド」及び「メタクリルアミド」の双方を包括する概念である。 Note that "(meth) acrylic acid-" in the present specification is a concept that includes both "acrylic acid-" and "methacrylic acid-". Similarly, "-(meth) acrylate" is a concept that includes both "-acrylate" and "-methacrylate". Similarly, "(meth) acrylamide" is a concept that includes both "acrylamide" and "methacrylamide".
　本明細書において、「Ａ～Ｂ」のように記載された数値範囲は、数値Ａを下限値として含み、かつ、数値Ｂを上限値として含むものとして解釈される。 In the present specification, the numerical range described as "AB" is interpreted as including the numerical value A as the lower limit value and the numerical value B as the upper limit value.
　１．蓄電デバイス用組成物
　本発明の一実施形態に係る蓄電デバイス用組成物は、重合体（Ａ）と、液状媒体（Ｂ）とを含有し、前記重合体（Ａ）中に含まれる繰り返し単位の合計を１００質量部としたときに、前記重合体（Ａ）が、環状カーボネート基を有する化合物に由来する繰り返し単位（ａ１）を１～５０質量部と、不飽和カルボン酸に由来する繰り返し単位（ａ２）、（メタ）アクリルアミドに由来する繰り返し単位（ａ３）、スルホ基を有する化合物に由来する繰り返し単位（ａ４）、及び水酸基を有する化合物に由来する繰り返し単位（ａ５）からなる群より選択される少なくとも１種の繰り返し単位を５０～９９質量部と、を含有する。 1. 1. Composition for power storage device The composition for power storage device according to one embodiment of the present invention contains a polymer (A) and a liquid medium (B), and is a repeating unit contained in the polymer (A). When the total is 100 parts by mass, the polymer (A) has 1 to 50 parts by mass of a repeating unit (a1) derived from a compound having a cyclic carbonate group, and a repeating unit derived from an unsaturated carboxylic acid (a repeating unit (a1). It is selected from the group consisting of a2), a repeating unit derived from (meth) acrylamide (a3), a repeating unit derived from a compound having a sulfo group (a4), and a repeating unit derived from a compound having a hydroxyl group (a5). It contains at least one repeating unit of 50 to 99 parts by mass.
　本実施形態に係る蓄電デバイス用組成物は、活物質同士の結合能力及び活物質と集電体との密着能力並びに粉落ち耐性を向上させた蓄電デバイス電極（活物質層）を作製するための材料として使用することもできるし、充放電に伴って発生するデンドライトに起因する短絡を抑制するための保護膜を形成するための材料として使用することもできる。以下、本実施形態に係る蓄電デバイス用組成物に含まれる各成分について詳細に説明する。 The composition for a power storage device according to the present embodiment is for producing a power storage device electrode (active material layer) having improved binding ability between active materials, adhesion ability between the active material and a current collector, and powder drop resistance. It can be used as a material, or it can be used as a material for forming a protective film for suppressing a short circuit caused by dendrites generated during charging and discharging. Hereinafter, each component contained in the composition for a power storage device according to the present embodiment will be described in detail.
　１．１．重合体（Ａ）
　本実施形態に係る蓄電デバイス用組成物は、重合体（Ａ）を含有する。重合体（Ａ）は、重合体（Ａ）中に含まれる繰り返し単位の合計を１００質量部としたときに、環状カーボネート基を有する化合物に由来する繰り返し単位（ａ１）（以下、単に「繰り返し単位（ａ１）」ともいう。）を１～５０質量部と、不飽和カルボン酸に由来する繰り返し単位（ａ２）（以下、単に「繰り返し単位（ａ２）」ともいう。）、（メタ）アクリルアミドに由来する繰り返し単位（ａ３）（以下、単に「繰り返し単位（ａ３）」ともいう。）、スルホ基を有する化合物に由来する繰り返し単位（ａ４）（以下、単に「繰り返し単位（ａ４）」ともいう。）、及び水酸基を有する化合物に由来する繰り返し単位（ａ５）（以下、単に「繰り返し単位（ａ５）」ともいう。）からなる群より選択される少なくとも１種の繰り返し単位を５０～９９質量部と、を含有する。 1.1. Polymer (A)
The composition for a power storage device according to this embodiment contains a polymer (A). The polymer (A) is a repeating unit (a1) derived from a compound having a cyclic carbonate group, assuming that the total of the repeating units contained in the polymer (A) is 100 parts by mass (hereinafter, simply "repeating unit"). (A1) ”) is derived from 1 to 50 parts by mass, a repeating unit (a2) derived from an unsaturated carboxylic acid (hereinafter, also simply referred to as a“ repeating unit (a2) ”), and (meth) acrylamide. Repeat unit (a3) (hereinafter, also simply referred to as "repeating unit (a3)"), repeating unit (a4) derived from a compound having a sulfo group (hereinafter, also simply referred to as "repeating unit (a4)"). , And at least one repeating unit selected from the group consisting of repeating units (a5) derived from a compound having a hydroxyl group (hereinafter, also simply referred to as “repeating unit (a5)”) is 50 to 99 parts by mass. Contains.
　また、重合体（Ａ）は、前記繰り返し単位の他に、それと共重合可能な他の単量体に由来する繰り返し単位を含有してもよい。他の単量体としては、例えば、不飽和カルボン酸エステル、共役ジエン化合物、芳香族ビニル化合物、α，β－不飽和ニトリル化合物、カチオン性単量体等が挙げられる。 Further, the polymer (A) may contain a repeating unit derived from another monomer copolymerizable therewith, in addition to the repeating unit. Examples of other monomers include unsaturated carboxylic acid esters, conjugated diene compounds, aromatic vinyl compounds, α, β-unsaturated nitrile compounds, and cationic monomers.
　本実施形態に係る蓄電デバイス用組成物に含まれる重合体（Ａ）は、液状媒体（Ｂ）中に分散されたラテックス状であってもよいし、液状媒体（Ｂ）中に溶解された状態であってもよいが、液状媒体（Ｂ）中に溶解された状態であることが好ましい。重合体（Ａ）が液状媒体（Ｂ）中に溶解された状態であると、活物質や無機フィラーと混合して作製される蓄電デバイス用スラリー（以下、単に「スラリー」ともいう。）の安定性が良好となり、またスラリーの集電体への塗布性が良好となるため好ましい。 The polymer (A) contained in the composition for a power storage device according to the present embodiment may be in the form of latex dispersed in the liquid medium (B), or may be in a state of being dissolved in the liquid medium (B). However, it is preferably in a state of being dissolved in the liquid medium (B). When the polymer (A) is dissolved in the liquid medium (B), the slurry for a power storage device (hereinafter, also simply referred to as “slurry”) produced by mixing with an active material or an inorganic filler is stable. It is preferable because the property is good and the property of the slurry to be applied to the current collector is good.
　以下、重合体（Ａ）を構成する各繰り返し単位、重合体（Ａ）の物性、製造方法の順に説明する。 Hereinafter, each repeating unit constituting the polymer (A), the physical properties of the polymer (A), and the production method will be described in this order.
　１．１．１．重合体（Ａ）を構成する繰り返し単位
　１．１．１．１．環状カーボネート基を有する化合物に由来する繰り返し単位（ａ１）
　環状カーボネート基を有する化合物に由来する繰り返し単位（ａ１）の含有割合は、重合体（Ａ）中に含まれる繰り返し単位の合計を１００質量部としたときに、１～５０質量部である。繰り返し単位（ａ１）の含有割合の下限値は、２質量部であることが好ましく、５質量部であることがより好ましく、７質量部であることがさらに好ましく、１０質量部であることが特に好ましい。繰り返し単位（ａ１）の含有割合の上限値は、４８質量部であることが好ましく、４５質量部であることがより好ましく、４０質量部であることが特に好ましい。繰り返し単位（ａ１）を前記範囲で含有することにより、活物質に環状カーボネート基を有する重合体（Ａ）を被覆させることができ、充電時に環状カーボネート基の分解により活物質表面に良好な被膜が形成され、電解液成分の分解を抑制し、電解液の枯渇を防ぐことができるため、充放電サイクルを実施した際の容量維持率が良好となる。また、ガラス転移温度の低い重合体（Ａ）が水溶液の状態で存在できるようになるため、活物質やフィラーの分散性が良好となる。さらに、重合体（Ａ）が柔軟性に優れるようになるため、重合体（Ａ）が活物質を被覆しても伸縮することによって電極板の構造欠陥の発生を抑制でき、良好な充放電耐久特性を示す。 1.1.1. Repeating unit constituting the polymer (A) 1.1.1.1. Repeating unit (a1) derived from a compound having a cyclic carbonate group
The content ratio of the repeating unit (a1) derived from the compound having a cyclic carbonate group is 1 to 50 parts by mass when the total of the repeating units contained in the polymer (A) is 100 parts by mass. The lower limit of the content ratio of the repeating unit (a1) is preferably 2 parts by mass, more preferably 5 parts by mass, further preferably 7 parts by mass, and particularly preferably 10 parts by mass. preferable. The upper limit of the content ratio of the repeating unit (a1) is preferably 48 parts by mass, more preferably 45 parts by mass, and particularly preferably 40 parts by mass. By containing the repeating unit (a1) in the above range, the active material can be coated with the polymer (A) having a cyclic carbonate group, and a good film is formed on the surface of the active material due to the decomposition of the cyclic carbonate group during charging. Since it is formed, decomposition of the electrolytic solution component can be suppressed, and depletion of the electrolytic solution can be prevented, the capacity retention rate when the charge / discharge cycle is carried out becomes good. Further, since the polymer (A) having a low glass transition temperature can exist in the state of an aqueous solution, the dispersibility of the active material and the filler becomes good. Further, since the polymer (A) becomes excellent in flexibility, it is possible to suppress the occurrence of structural defects of the electrode plate by expanding and contracting even if the polymer (A) coats the active material, and has good charge / discharge durability. Shows the characteristics.
　環状カーボネート基を有する化合物としては、特に限定されないが、下記一般式（１）で表される化合物又は下記一般式（２）で表される化合物が挙げられる。 The compound having a cyclic carbonate group is not particularly limited, and examples thereof include a compound represented by the following general formula (1) and a compound represented by the following general formula (2).
Figure JPOXMLDOC01-appb-C000001
  
Figure JPOXMLDOC01-appb-C000001
  
　上記一般式（１）及び上記一般式（２）中、Ｒ１は水素原子又はメチル基を表す。Ｒ２は単結合又は２価の連結基を表す。Ｒ３は環状カーボネート構造を有する１価の有機基を表す。 In the general formula (1) and the above general formula (2), R 1 represents a hydrogen atom or a methyl group. R 2 represents a single bond or a divalent linking group. R 3 represents a monovalent organic group having a cyclic carbonate structure.
　Ｒ３としては、下記一般式（３）又は下記一般式（４）で表される基が挙げられる。 Examples of R 3 include groups represented by the following general formula (3) or the following general formula (4).
Figure JPOXMLDOC01-appb-C000002
  
Figure JPOXMLDOC01-appb-C000002
  
　上記一般式（３）及び上記一般式（４）中、ｎ１は０～２の整数を表し、ｎ２～ｎ５はそれぞれ独立に０～２の整数を表し、「＊」は上記一般式（１）又は上記一般式（２）中のＲ２に結合する結合手を表す。また、上記一般式（３）及び上記一般式（４）で表される基は置換基を有していてもよい。 In the general formula (3) and the general formula (4), n1 represents an integer of 0 to 2, n2 to n5 independently represent an integer of 0 to 2, and "*" represents the general formula (1). Alternatively, it represents a bond that binds to R 2 in the above general formula (2). Further, the groups represented by the general formula (3) and the general formula (4) may have a substituent.
　上記一般式（３）で表される基の具体例としては、下記式（５）で表される基を挙げることができる。上記一般式（４）で表される基の具体例としては、下記式（６）で表される基を挙げることができる。 As a specific example of the group represented by the above general formula (3), a group represented by the following formula (5) can be mentioned. Specific examples of the group represented by the general formula (4) include a group represented by the following formula (6).
Figure JPOXMLDOC01-appb-C000003
  
Figure JPOXMLDOC01-appb-C000003
  
　これらの化合物の中でも、下記一般式（７）又は下記一般式（８）で表される化合物であることが好ましい。 Among these compounds, the compound represented by the following general formula (7) or the following general formula (8) is preferable.
Figure JPOXMLDOC01-appb-C000004
  
Figure JPOXMLDOC01-appb-C000004
  
　上記一般式（７）及び上記一般式（８）中、Ｒ１は水素原子又はメチル基を表す。 In the general formula (7) and the above general formula (8), R 1 represents a hydrogen atom or a methyl group.
　１．１．１．２．不飽和カルボン酸に由来する繰り返し単位（ａ２）
　重合体（Ａ）は、不飽和カルボン酸に由来する繰り返し単位（ａ２）を含有することができる。不飽和カルボン酸に由来する繰り返し単位（ａ２）の含有割合は、重合体（Ａ）中に含まれる繰り返し単位の合計を１００質量部としたときに、５～９０質量部であることが好ましい。繰り返し単位（ａ２）の含有割合の下限値は、７質量部であることが好ましく、１０質量部であることがより好ましい。繰り返し単位（ａ２）の含有割合の上限値は、８５質量部であることが好ましく、８０質量部であることがより好ましい。繰り返し単位（ａ２）を前記範囲で含有することにより、活物質やフィラーの分散性が良好となる。さらに、活物質としてのケイ素材料との親和性を向上させ、該ケイ素材料の膨潤を抑制することで良好な充放電耐久特性を示す。 1.1.1.2. Repeating unit derived from unsaturated carboxylic acid (a2)
The polymer (A) can contain a repeating unit (a2) derived from an unsaturated carboxylic acid. The content ratio of the repeating unit (a2) derived from the unsaturated carboxylic acid is preferably 5 to 90 parts by mass when the total of the repeating units contained in the polymer (A) is 100 parts by mass. The lower limit of the content ratio of the repeating unit (a2) is preferably 7 parts by mass, more preferably 10 parts by mass. The upper limit of the content ratio of the repeating unit (a2) is preferably 85 parts by mass, more preferably 80 parts by mass. By containing the repeating unit (a2) in the above range, the dispersibility of the active material and the filler becomes good. Further, it exhibits good charge / discharge durability characteristics by improving the affinity with the silicon material as an active material and suppressing the swelling of the silicon material.
　不飽和カルボン酸としては、特に限定されないが、アクリル酸、メタクリル酸、クロトン酸、マレイン酸、フマル酸、イタコン酸等のモノ又はジカルボン酸を挙げることができ、これらから選択される１種以上であることができる。 The unsaturated carboxylic acid is not particularly limited, and examples thereof include mono- or dicarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid, and one or more selected from these. There can be.
　１．１．１．３．（メタ）アクリルアミドに由来する繰り返し単位（ａ３）
　重合体（Ａ）は、（メタ）アクリルアミドに由来する繰り返し単位（ａ３）を含有することができる。（メタ）アクリルアミドに由来する繰り返し単位（ａ３）の含有割合は、重合体（Ａ）中に含まれる繰り返し単位の合計を１００質量部としたときに、５～９０質量部であることが好ましい。繰り返し単位（ａ３）の含有割合の下限値は、７質量部であることが好ましく、１０質量部であることがより好ましい。繰り返し単位（ａ３）の含有割合の上限値は、８５質量部であることが好ましく、８０質量部であることがより好ましい。繰り返し単位（ａ３）を前記範囲で含有することにより、重合体（Ａ）のガラス転移度（Ｔｇ）が好適となり、その結果、活物質やフィラーの分散性が良好となる。また、得られる活物質層の柔軟性が適度となり、集電体と活物質層との密着能力が良好となる。さらに、グラファイトのような炭素材料とケイ素材料を含有する活物質同士の結合能力を高めることができるため、得られる活物質層は、柔軟性や集電体に対する密着能力がより良好なものとなる。 1.1.1.3. Repeat unit derived from (meth) acrylamide (a3)
The polymer (A) can contain a repeating unit (a3) derived from (meth) acrylamide. The content ratio of the repeating unit (a3) derived from (meth) acrylamide is preferably 5 to 90 parts by mass when the total of the repeating units contained in the polymer (A) is 100 parts by mass. The lower limit of the content ratio of the repeating unit (a3) is preferably 7 parts by mass, more preferably 10 parts by mass. The upper limit of the content ratio of the repeating unit (a3) is preferably 85 parts by mass, more preferably 80 parts by mass. By containing the repeating unit (a3) in the above range, the glass transition degree (Tg) of the polymer (A) becomes suitable, and as a result, the dispersibility of the active material and the filler becomes good. In addition, the flexibility of the obtained active material layer becomes appropriate, and the adhesion ability between the current collector and the active material layer becomes good. Further, since the bonding ability between the active materials containing the carbon material such as graphite and the silicon material can be enhanced, the obtained active material layer has better flexibility and adhesion to the current collector. ..
　（メタ）アクリルアミドとしては、特に限定されないが、アクリルアミド、メタクリルアミド、Ｎ－イソプロピルアクリルアミド、Ｎ，Ｎ－ジメチルアクリルアミド、Ｎ，Ｎ－ジメチルメタクリルアミド、Ｎ，Ｎ－ジエチルアクリルアミド、Ｎ，Ｎ－ジエチルメタクリルアミド、Ｎ，Ｎ－ジメチルアミノプロピルアクリルアミド、Ｎ，Ｎ－ジメチルアミノプロピルメタクリルアミド、Ｎ－メチロールメタクリルアミド、Ｎ－メチロールアクリルアミド、ジアセトンアクリルアミド、マレイン酸アミド、アクリルアミドｔｅｒｔ－ブチルスルホン酸等が挙げられる。これらの（メタ）アクリルアミドは、１種単独で用いてもよく、２種以上を併用してもよい。 The (meth) acrylamide is not particularly limited, but is limited to acrylamide, methacrylamide, N-isopropylacrylamide, N, N-dimethylacrylamide, N, N-dimethylmethacrylicamide, N, N-diethylacrylamide, N, N-diethylmethacryl. Examples thereof include amide, N, N-dimethylaminopropyl acrylamide, N, N-dimethylaminopropyl methacrylamide, N-methylol methacrylamide, N-methylol acrylamide, diacetone acrylamide, maleic acid amide, acrylamide tert-butyl sulfonic acid and the like. .. These (meth) acrylamides may be used alone or in combination of two or more.
　１．１．１．４．スルホ基を有する化合物に由来する繰り返し単位（ａ４）
　重合体（Ａ）は、スルホ基を有する化合物に由来する繰り返し単位（ａ４）を含有することができる。ここで、スルホ基を有する化合物は、重合反応に寄与するエチレン性不飽和基を有するので、厳密に言えば、エチレン性不飽和基及びスルホ基を有する化合物である。 1.1.1.4. Repeating unit (a4) derived from a compound having a sulfo group
The polymer (A) can contain a repeating unit (a4) derived from a compound having a sulfo group. Here, since the compound having a sulfo group has an ethylenically unsaturated group that contributes to the polymerization reaction, strictly speaking, it is a compound having an ethylenically unsaturated group and a sulfo group.
　スルホ基を有する化合物に由来する繰り返し単位（ａ４）の含有割合は、重合体（Ａ）中に含まれる繰り返し単位の合計を１００質量部としたときに、５～９０質量部であることが好ましい。繰り返し単位（ａ４）の含有割合の下限値は、７質量部であることが好ましく、１０質量部であることがより好ましい。繰り返し単位（ａ４）の含有割合の上限値は、８５質量部であることが好ましく、８０質量部であることがより好ましい。繰り返し単位（ａ４）を前記範囲で含有することにより、重合体（Ａ）のガラス転移温度（Ｔｇ）が好適となり、その結果、活物質やフィラーの分散性が良好となる。また、得られる活物質層の柔軟性が適度となり、集電体と活物質層との密着能力が良好となる。さらに、グラファイトのような炭素材料とケイ素材料を含有する活物質同士の結合能力を高めることができるため、得られる活物質層は、柔軟性や集電体に対する密着能力がより良好なものとなる。 The content ratio of the repeating unit (a4) derived from the compound having a sulfo group is preferably 5 to 90 parts by mass when the total of the repeating units contained in the polymer (A) is 100 parts by mass. .. The lower limit of the content ratio of the repeating unit (a4) is preferably 7 parts by mass, more preferably 10 parts by mass. The upper limit of the content ratio of the repeating unit (a4) is preferably 85 parts by mass, more preferably 80 parts by mass. By containing the repeating unit (a4) in the above range, the glass transition temperature (Tg) of the polymer (A) becomes suitable, and as a result, the dispersibility of the active material and the filler becomes good. In addition, the flexibility of the obtained active material layer becomes appropriate, and the adhesion ability between the current collector and the active material layer becomes good. Further, since the bonding ability between the active materials containing the carbon material such as graphite and the silicon material can be enhanced, the obtained active material layer has better flexibility and adhesion to the current collector. ..
　スルホ基を有する化合物の具体例としては、特に限定されないが、ビニルスルホン酸、スチレンスルホン酸、アリルスルホン酸、スルホエチル（メタ）アクリレート、スルホプロピル（メタ）アクリレート、スルホブチル（メタ）アクリレート、２－アクリルアミド－２－メチルプロパンスルホン酸、２－ヒドロキシ－３－アクリルアミドプロパンスルホン酸、３－アリロキシ－２－ヒドロキシプロパンスルホン酸等のスルホン酸基を有する化合物、及びこれらのアルカリ塩などを用いてもよい。 Specific examples of the compound having a sulfo group are not particularly limited, but vinyl sulfonic acid, styrene sulfonic acid, allyl sulfonic acid, sulfoethyl (meth) acrylate, sulfopropyl (meth) acrylate, sulfobutyl (meth) acrylate, 2-acrylamide. Compounds having a sulfonic acid group such as -2-methylpropanesulfonic acid, 2-hydroxy-3-acrylamidepropanesulfonic acid, 3-allyloxy-2-hydroxypropanesulfonic acid, and alkali salts thereof may be used.
　１．１．１．５．水酸基を有する化合物に由来する繰り返し単位（ａ５）
　重合体（Ａ）は、水酸基を有する化合物に由来する繰り返し単位（ａ５）を含有することができる。ここで、水酸基を有する化合物は、重合反応に寄与するエチレン性不飽和基を有するので、厳密に言えば、エチレン性不飽和基及び水酸基を有する化合物である。 1.1.1.5. Repeating unit (a5) derived from a compound having a hydroxyl group
The polymer (A) can contain a repeating unit (a5) derived from a compound having a hydroxyl group. Here, since the compound having a hydroxyl group has an ethylenically unsaturated group that contributes to the polymerization reaction, strictly speaking, it is a compound having an ethylenically unsaturated group and a hydroxyl group.
　水酸基を有する化合物に由来する繰り返し単位（ａ５）の含有割合は、重合体（Ａ）中に含まれる繰り返し単位の合計を１００質量部としたときに、５～９０質量部であることが好ましい。繰り返し単位（ａ５）の含有割合の下限値は、７質量部であることが好ましく、１０質量部であることがより好ましい。繰り返し単位（ａ５）の含有割合の上限値は、８５質量部であることが好ましく、８０質量部であることがより好ましい。繰り返し単位（ａ５）を前記範囲で含有することにより、重合体（Ａ）のガラス転移温度（Ｔｇ）が好適となり、その結果、活物質やフィラーの分散性が良好となる。また、得られる活物質層の柔軟性が適度となり、集電体と活物質層との密着能力が良好となる。さらに、グラファイトのような炭素材料とケイ素材料を含有する活物質同士の結合能力を高めることができるため、得られる活物質層は、柔軟性や集電体に対する密着能力がより良好なものとなる。 The content ratio of the repeating unit (a5) derived from the compound having a hydroxyl group is preferably 5 to 90 parts by mass when the total of the repeating units contained in the polymer (A) is 100 parts by mass. The lower limit of the content ratio of the repeating unit (a5) is preferably 7 parts by mass, more preferably 10 parts by mass. The upper limit of the content ratio of the repeating unit (a5) is preferably 85 parts by mass, more preferably 80 parts by mass. By containing the repeating unit (a5) in the above range, the glass transition temperature (Tg) of the polymer (A) becomes suitable, and as a result, the dispersibility of the active material and the filler becomes good. In addition, the flexibility of the obtained active material layer becomes appropriate, and the adhesion ability between the current collector and the active material layer becomes good. Further, since the bonding ability between the active materials containing the carbon material such as graphite and the silicon material can be enhanced, the obtained active material layer has better flexibility and adhesion to the current collector. ..
　水酸基を有する化合物の具体例としては、特に限定されないが、２－ヒドロキシエチル（メタ）アクリレート、２－ヒドロキシプロピル（メタ）アクリレート、３－ヒドロキシプロピル（メタ）アクリレート、４－ヒドロキシブチル（メタ）アクリレート、５－ヒドロキシペンチル（メタ）アクリレート、６－ヒドロキシヘキシル（メタ）アクリレート、グリセリンモノ（メタ）アクリレート、グリセリンジ（メタ）アクリレート等の不飽和カルボン酸エステル；ビニルアルコール、２－ビニルフェノール、３－ビニルフェノール、４－ビニルフェノール等が挙げられる。これらの中でも、２－ヒドロキシエチル（メタ）アクリレート、グリセリンモノ（メタ）アクリレートが好ましい。なお、これらの単量体は、１種単独でまたは２種以上を組み合わせて用いることができる。 Specific examples of the compound having a hydroxyl group are not particularly limited, but are 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. , 5-Hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, glycerin mono (meth) acrylate, glycerin di (meth) acrylate and other unsaturated carboxylic acid esters; vinyl alcohol, 2-vinylphenol, 3- Examples thereof include vinylphenol and 4-vinylphenol. Among these, 2-hydroxyethyl (meth) acrylate and glycerin mono (meth) acrylate are preferable. In addition, these monomers can be used individually by 1 type or in combination of 2 or more types.
　１．１．１．６．繰り返し単位（ａ２）～（ａ５）の含有割合
　重合体（Ａ）は、重合体（Ａ）中に含まれる繰り返し単位の合計を１００質量部としたときに、繰り返し単位（ａ２）、繰り返し単位（ａ３）、繰り返し単位（ａ４）及び繰り返し単位（ａ５）からなる群より選択される少なくとも１種の繰り返し単位を５０～９９質量部含有する。繰り返し単位（ａ２）～（ａ５）の含有割合の下限値は、５５質量部であることが好ましく、６０質量部であることがより好ましい。繰り返し単位（ａ２）～（ａ５）の含有割合の上限値は、９５質量部であることが好ましく、９０質量部であることがより好ましい。繰り返し単位（ａ２）～（ａ５）を前記範囲で含有することにより、重合体（Ａ）のガラス転移温度（Ｔｇ）がより好適となり、柔軟性に優れる電極板の作製が可能となる。これにより、充放電耐久特性に優れた電極板が得られる。また、重合体（Ａ）と活物質やフィラーとの親和性がより良好となり、活物質やフィラーの分散性がより良好なスラリーが得られる。 1.1.1.6. Content ratio of repeating units (a2) to (a5) The polymer (A) has a repeating unit (a2) and a repeating unit (a2) when the total of the repeating units contained in the polymer (A) is 100 parts by mass. It contains 50 to 99 parts by mass of at least one repeating unit selected from the group consisting of a3), a repeating unit (a4) and a repeating unit (a5). The lower limit of the content ratio of the repeating units (a2) to (a5) is preferably 55 parts by mass, more preferably 60 parts by mass. The upper limit of the content ratio of the repeating units (a2) to (a5) is preferably 95 parts by mass, more preferably 90 parts by mass. By containing the repeating units (a2) to (a5) in the above range, the glass transition temperature (Tg) of the polymer (A) becomes more suitable, and an electrode plate having excellent flexibility can be produced. As a result, an electrode plate having excellent charge / discharge durability characteristics can be obtained. Further, the affinity between the polymer (A) and the active material or filler becomes better, and a slurry having better dispersibility of the active material or filler can be obtained.
　１．１．１．７．その他の繰り返し単位
　重合体（Ａ）は、前記繰り返し単位（ａ１）～（ａ５）の他に、これらと共重合可能な他の単量体に由来する繰り返し単位を含有してもよい。このような繰り返し単位としては、不飽和カルボン酸エステルに由来する繰り返し単位（前記繰り返し単位（ａ１）～（ａ５）に該当するものを除く。以下、単に「繰り返し単位（ａ６）」ともいう。）、共役ジエン化合物に由来する繰り返し単位（ａ７）（以下、単に「繰り返し単位（ａ７）」ともいう。）、芳香族ビニル化合物に由来する繰り返し単位（ａ８）（以下、単に「繰り返し単位（ａ８）」ともいう。）、α，β－不飽和ニトリル化合物に由来する繰り返し単位（ａ９）（以下、単に「繰り返し単位（ａ９）」ともいう。）、カチオン性単量体に由来する繰り返し単位（以下、単に「繰り返し単位（ａ１０）」ともいう。）等が挙げられる。 11.1.7. Other Repeating Units The polymer (A) may contain repeating units derived from other monomers copolymerizable with the repeating units (a1) to (a5) in addition to the repeating units (a1) to (a5). Such a repeating unit is a repeating unit derived from an unsaturated carboxylic acid ester (excluding those corresponding to the repeating units (a1) to (a5). Hereinafter, it is also simply referred to as “repeating unit (a6)”). , The repeating unit (a7) derived from the conjugated diene compound (hereinafter, also simply referred to as “repeating unit (a7)”), the repeating unit (a8) derived from the aromatic vinyl compound (hereinafter, simply “repeating unit (a8)). ”), Repeating unit (a9) derived from α, β-unsaturated nitrile compound (hereinafter, also simply referred to as“ repeating unit (a9) ”), repeating unit derived from cationic monomer (hereinafter, also referred to as“ repeating unit ”). , Simply referred to as "repeating unit (a10)") and the like.
　不飽和カルボン酸エステルとしては、特に限定されないが、（メタ）アクリル酸エステルが好ましい。（メタ）アクリル酸エステルの具体例としては、（メタ）アクリル酸メチル、（メタ）アクリル酸エチル、（メタ）アクリル酸ｎ－プロピル、（メタ）アクリル酸イソプロピル、（メタ）アクリル酸ｎ－ブチル、（メタ）アクリル酸イソブチル、（メタ）アクリル酸ｎ－アミル、（メタ）アクリル酸イソアミル、（メタ）アクリル酸ヘキシル、（メタ）アクリル酸シクロヘキシル、（メタ）アクリル酸２－エチルヘキシル、（メタ）アクリル酸ｎ－オクチル、（メタ）アクリル酸ノニル、（メタ）アクリル酸デシル、（メタ）アクリル酸アリル等を挙げることができ、これらの中から選択される１種以上であることができる。これらのうち、（メタ）アクリル酸メチル、（メタ）アクリル酸エチル、（メタ）アクリル酸ｎ－ブチル、（メタ）アクリル酸シクロヘキシル及び（メタ）アクリル酸２－エチルヘキシルから選択される１種以上であることが好ましく、（メタ）アクリル酸メチルであることが特に好ましい。 The unsaturated carboxylic acid ester is not particularly limited, but a (meth) acrylic acid ester is preferable. Specific examples of the (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and n-butyl (meth) acrylate. , (Meta) isobutyl acrylate, (meth) n-amyl acrylate, (meth) isoamyl acrylate, (meth) hexyl acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) Examples thereof include n-octyl acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, and allyl (meth) acrylate, and one or more of these can be selected. Of these, one or more selected from methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, cyclohexyl (meth) acrylate and 2-ethylhexyl (meth) acrylate. It is preferably present, and particularly preferably methyl (meth) acrylate.
　共役ジエン化合物としては、特に限定されないが、１，３－ブタジエン、２－メチル－１，３－ブタジエン、２，３－ジメチル－１，３－ブタジエン、２－クロル－１，３－ブタジエンなどを挙げることができ、これらの中から選択される１種以上であることができる。これらの中でも、１，３－ブタジエンが特に好ましい。 The conjugated diene compound is not particularly limited, but 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-chlor-1,3-butadiene and the like can be used. It can be listed and can be one or more selected from these. Of these, 1,3-butadiene is particularly preferable.
　芳香族ビニル化合物としては、特に限定されないが、スチレン、α－メチルスチレン、ｐ－メチルスチレン、ビニルトルエン、クロルスチレン、ジビニルベンゼン等を挙げることができ、これらの中から選択される１種以上であることができる。これらのうち、スチレンであることが特に好ましい。 The aromatic vinyl compound is not particularly limited, and examples thereof include styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, chlorostyrene, and divinylbenzene, and one or more selected from these can be used. There can be. Of these, styrene is particularly preferable.
　α，β－不飽和ニトリル化合物としては、特に限定されないが、アクリロニトリル、メタクリロニトリル、α－クロルアクリロニトリル、α－エチルアクリロニトリル、シアン化ビニリデン等を挙げることができ、これらの中から選択される１種以上であることができる。これらのうち、アクリロニトリル及びメタクリロニトリルから選択される１種以上であることが好ましく、アクリロニトリルであることが特に好ましい。 The α, β-unsaturated nitrile compound is not particularly limited, and examples thereof include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethylacrylonitrile, vinylidene cyanide, and the like, and are selected from these 1 Can be more than a seed. Of these, one or more selected from acrylonitrile and methacrylonitrile is preferable, and acrylonitrile is particularly preferable.
　カチオン性単量体としては、特に限定されないが、第二級アミン（塩）、第三級アミン（塩）及び第四級アンモニウム塩からなる群より選択される少なくとも１種の単量体であることが好ましい。これらカチオン性単量体の具体例としては、特に限定されないが、（メタ）アクリル酸２－（ジメチルアミノ）エチル、ジメチルアミノエチル（メタ）アクリレート塩化メチル４級塩、（メタ）アクリル酸２－（ジエチルアミノ）エチル、（メタ）アクリル酸３－（ジメチルアミノ）プロピル、（メタ）アクリル酸３－（ジエチルアミノ）プロピル、（メタ）アクリル酸４－（ジメチルアミノ）フェニル、（メタ）アクリル酸２－［（３，５－ジメチルピラゾリル）カルボニルアミノ］エチル、（メタ）アクリル酸２－（０－［１’－メチルプロピリデンアミノ］カルボキシアミノ）エチル、（メタ）アクリル酸２－（１－アジリジニル）エチル、メタクロイルコリンクロリド、イソシアヌル酸トリス（２－アクリロイルオキシエチル）、２－ビニルピリジン、キナルジンレッド、１，２－ジ（２－ピリジル）エチレン、４’－ヒドラジノ－２－スチルバゾール二塩酸塩水和物、４－（４－ジメチルアミノスチリル）キノリン、１－ビニルイミダゾール、ジアリルアミン、ジアリルアミン塩酸塩、トリアリルアミン、ジアリルジメチルアンモニウムクロリド、ジクロルミド、Ｎ－アリルベンジルアミン、Ｎ－アリルアニリン、２，４－ジアミノ－６－ジアリルアミノ－１，３，５－トリアジン、Ｎ－ｔｒａｎｓ－シンナミル－Ｎ－メチル－（１－ナフチルメチル）アミン塩酸塩、ｔｒａｎｓ－Ｎ－（６，６－ジメチル－２－ヘプテン－４－イニル）－Ｎ－メチル－１－ナフチルメチルアミン塩酸塩等が挙げられる。これらの単量体は、１種単独で用いてもよく、２種以上を併用してもよい。 The cationic monomer is not particularly limited, but is at least one monomer selected from the group consisting of a secondary amine (salt), a tertiary amine (salt) and a quaternary ammonium salt. Is preferable. Specific examples of these cationic monomers are not particularly limited, but are 2- (dimethylamino) ethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate methyl quaternary chloride quaternary salt, and 2- (meth) acrylate. (Diethylamino) ethyl, 3- (dimethylamino) propyl (meth) acrylate, 3- (diethylamino) propyl (meth) acrylate, 4- (dimethylamino) phenyl (meth) acrylate, 2- (meth) acrylate [(3,5-Dimethylpyrazolyl) carbonylamino] ethyl, (meth) acrylate 2- (0- [1'-methylpropyridaneamino] carboxyamino) ethyl, (meth) acrylate 2- (1-aziridinyl) Ethyl, metachlorocholine chloride, tris isocyanurate (2-acryloyloxyethyl), 2-vinylpyridine, quinaldine red, 1,2-di (2-pyridyl) ethylene, 4'-hydrazino-2-stilbazole dihydrochloride water Japanese product, 4- (4-dimethylaminostyryl) quinoline, 1-vinylimidazole, diallylamine, diallylamine hydrochloride, triallylamine, diallyldimethylammonium chloride, dichloromid, N-allylbenzylamine, N-allylaniline, 2,4- Diamino-6-diallylamino-1,3,5-triazine, N-trans-cinnamyl-N-methyl- (1-naphthylmethyl) amine hydrochloride, trans-N- (6,6-dimethyl-2-heptene-) 4-Inyl) -N-methyl-1-naphthylmethylamine hydrochloride and the like can be mentioned. These monomers may be used alone or in combination of two or more.
　重合体（Ａ）は、重合体（Ａ）中に含まれる繰り返し単位の合計を１００質量部としたときに、繰り返し単位（ａ６）、繰り返し単位（ａ７）、繰り返し単位（ａ８）、繰り返し単位（ａ９）及び繰り返し単位（ａ１０）を合計で２０質量部以下含有することが好ましい。この繰り返し単位（ａ６）～（ａ１０）の含有割合は、０～１５質量部であることがより好ましく、０～１０質量部であることが特に好ましい。 The polymer (A) has a repeating unit (a6), a repeating unit (a7), a repeating unit (a8), and a repeating unit (a6), assuming that the total of the repeating units contained in the polymer (A) is 100 parts by mass. It is preferable to contain 20 parts by mass or less of a9) and the repeating unit (a10) in total. The content ratio of the repeating units (a6) to (a10) is more preferably 0 to 15 parts by mass, and particularly preferably 0 to 10 parts by mass.
　１．１．２．重合体（Ａ）の物性
＜水に対する溶解度＞
　重合体（Ａ）は、水溶性重合体であることが好ましい。本発明における「水溶性重合体」とは、２５℃、１気圧における水に対する溶解度が、水１００ｇに対し１ｇ以上である重合体のことをいう。重合体（Ａ）が水溶性重合体であると、柔軟性や密着性に優れる重合体（Ａ）によって活物質の表面がコーティングされやすくなるので、充放電時における活物質の伸縮による脱落を効果的に抑制でき、良好な充放電耐久特性を示す蓄電デバイスが得られやすい。また、スラリーの安定性が良好となり、スラリーの集電体への塗布性も良好となるため好ましい。 1.1.2. Physical characteristics of polymer (A) <Solubility in water>
The polymer (A) is preferably a water-soluble polymer. The "water-soluble polymer" in the present invention refers to a polymer having a solubility in water at 25 ° C. and 1 atm of 1 g or more with respect to 100 g of water. When the polymer (A) is a water-soluble polymer, the surface of the active material is easily coated by the polymer (A) having excellent flexibility and adhesion, so that the active material can be effectively removed by expansion and contraction during charging and discharging. It is easy to obtain a power storage device that can be effectively suppressed and exhibits good charge / discharge durability characteristics. Further, the stability of the slurry is improved, and the applicability of the slurry to the current collector is also improved, which is preferable.
＜粘度＞
　重合体（Ａ）の１０質量％水溶液の、ｐＨ９における粘度は、２０～２００，０００ｍＰａ・ｓであることが好ましく、５０～１５０，０００ｍＰａ・ｓであることがより好ましく、１，０００～１５０，０００ｍＰａ・ｓであることが特に好ましい。重合体（Ａ）の１０質量％水溶液の、ｐＨ９における粘度が前記範囲であると、活物質やフィラーの分散性が良好となり、均一な活物質層や保護膜を作成しやすい。その結果、構造欠陥のない電極等が得られ、良好な充放電特性を示すため好ましい。 <Viscosity>
The viscosity of the 10% by mass aqueous solution of the polymer (A) at pH 9 is preferably 20 to 200,000 mPa · s, more preferably 50 to 150,000 mPa · s, and 1,000 to 150, It is particularly preferably 000 mPa · s. When the viscosity of the 10% by mass aqueous solution of the polymer (A) at pH 9 is in the above range, the dispersibility of the active material and the filler becomes good, and a uniform active material layer and a protective film can be easily formed. As a result, an electrode or the like having no structural defects can be obtained, which is preferable because it exhibits good charge / discharge characteristics.
　重合体（Ａ）の１０質量％水溶液の粘度は、温度２５．０℃において、Ｂ型粘度計を用いて、ＪＩＳ　Ｚ　８８０３に準拠して測定した値である。Ｂ型粘度計としては、例えば東機産業社製「ＲＢ－８０Ｌ」や「ＴＶＢ－１０」等を使用することができる。 The viscosity of the 10% by mass aqueous solution of the polymer (A) is a value measured at a temperature of 25.0 ° C. using a B-type viscometer in accordance with JIS Z8803. As the B-type viscometer, for example, "RB-80L" or "TVB-10" manufactured by Toki Sangyo Co., Ltd. can be used.
＜数平均分子量（Ｍｎ）＞
　重合体（Ａ）の数平均分子量（Ｍｎ）は、好ましくは１０，０００以上２，０００，０００以下であり、より好ましくは５０，０００以上１，５００，０００以下であり、特に好ましくは１００，０００以上１，０００，０００以下である。重合体（Ａ）の数平均分子量（Ｍｎ）が前記範囲にあると、密着性が良好となり、充放電特性に優れた蓄電デバイスが得られやすい。重合体（Ａ）の数平均分子量は、例えば、以下の条件によるＧＰＣ法を用いて測定することができる。
（測定条件）
・測定機器：東ソー株式会社製、ＧＰＣ（型番：ＨＬＣ－８２２０）
・カラム：ＴＳＫｇｅｌ　ｇｕａｒｄｃｏｌｕｍ　ＰＷＸＬ　（東ソー株式会社製）、ＴＳＫ－ＧＥＬ　Ｇ２５００ＰＷＸＬ（東ソー株式会社製）、ＴＳＫ－ＧＥＬ　ＧＭＰＷＸＬ（東ソー株式会社製）
・溶離液：０．１Ｍ　ＮａＮＯ３水溶液
・検量線：標準ポリエチレンオキシド
・測定方法：重合体（Ａ）の固形分が０．３ｗｔ％となるように溶離液に溶解し、フィルターろ過後に測定する。 <Number average molecular weight (Mn)>
The number average molecular weight (Mn) of the polymer (A) is preferably 10,000 or more and 2,000,000 or less, more preferably 50,000 or more and 1,500,000 or less, and particularly preferably 100, It is 000 or more and 1,000,000 or less. When the number average molecular weight (Mn) of the polymer (A) is within the above range, the adhesion is good and it is easy to obtain a power storage device having excellent charge / discharge characteristics. The number average molecular weight of the polymer (A) can be measured, for example, by using the GPC method under the following conditions.
(Measurement condition)
-Measuring equipment: GPC (model number: HLC-8220) manufactured by Tosoh Corporation
-Column: TSKgel guardcolum PW XL (manufactured by Tosoh Co., Ltd.), TSK-GEL G2500PW XL (manufactured by Tosoh Co., Ltd.), TSK-GEL GMPW XL (manufactured by Tosoh Co., Ltd.)
-Eluent: 0.1 M NaNO 3 aqueous solution-Calibration curve: Standard polyethylene oxide-Measurement method: Dissolve the polymer (A) in the eluent so that the solid content is 0.3 wt%, and measure after filtering.
＜ガラス転移温度＞
　重合体（Ａ）は、ＪＩＳ　Ｋ　７１２１に準拠する示差走査熱量測定（ＤＳＣ）によって測定したときに、６０℃～１６０℃の温度範囲において吸熱ピークを１つのみ有するものであることが好ましい。この吸熱ピークの温度（すなわち、ガラス転移温度（Ｔｇ））は、７０℃～１５０℃の範囲にあることがより好ましい。ＤＳＣ分析における重合体（Ａ）の吸熱ピークが１つのみであり、かつ、該ピーク温度が前記範囲にある場合、重合体（Ａ）は良好な密着性を示すとともに、活物質層に対してより良好な柔軟性及び粘着性を付与することができるので好ましい。 <Glass transition temperature>
The polymer (A) preferably has only one endothermic peak in the temperature range of 60 ° C. to 160 ° C. as measured by differential scanning calorimetry (DSC) according to JIS K 7121. The temperature of this endothermic peak (that is, the glass transition temperature (Tg)) is more preferably in the range of 70 ° C. to 150 ° C. When the polymer (A) has only one endothermic peak in the DSC analysis and the peak temperature is in the above range, the polymer (A) exhibits good adhesion and has good adhesion to the active material layer. It is preferable because it can impart better flexibility and adhesiveness.
　１．１．３．重合体（Ａ）の製造方法
　重合体（Ａ）の製造方法は、特に限定されないが、例えば水を主成分とした溶媒中で公知の連鎖移動剤、重合開始剤などの存在下で行う重合が好ましい。重合体（Ａ）は、一段重合で合成してもよく、二段重合もしくは多段重合で合成してもよく、それぞれの重合において公知の重合開始剤、分子量調整剤、乳化剤（界面活性剤）等の存在下で合成することができる。重合開始剤、分子量調整剤、乳化剤（界面活性剤）等の量や種類、合成方法については、特許第５４７７６１０号公報等に記載された成分や方法を用いることができる。 11.3. Method for Producing Polymer (A) The method for producing the polymer (A) is not particularly limited, but for example, polymerization performed in a solvent containing water as a main component in the presence of a known chain transfer agent, polymerization initiator, or the like can be performed. preferable. The polymer (A) may be synthesized by one-step polymerization, two-step polymerization or multi-step polymerization, and a polymerization initiator, a molecular weight modifier, an emulsifier (surfactant) and the like known in each polymerization. Can be synthesized in the presence of. As for the amount and type of the polymerization initiator, the molecular weight adjusting agent, the emulsifier (surfactant) and the like, and the synthesis method, the components and methods described in Japanese Patent No. 5477610 and the like can be used.
　上記合成方法によって得られた重合混合物に中和剤を添加することにより、ｐＨを５～１１に調整してもよい。ここで使用する中和剤としては、特に限定されるものではないが、例えば水酸化ナトリウム、水酸化カリウムなどの金属水酸化物；アンモニア等を挙げることができる。上記のｐＨ範囲に調整することにより、重合体（Ａ）を液状媒体（Ｂ）に溶解させて増粘させることができる。また、中和処理を行った後に、重合混合物を濃縮することにより、重合体（Ａ）の良好な安定性を維持しながら固形分濃度を高くすることができる。 The pH may be adjusted to 5 to 11 by adding a neutralizing agent to the polymerization mixture obtained by the above synthesis method. The neutralizing agent used here is not particularly limited, and examples thereof include metal hydroxides such as sodium hydroxide and potassium hydroxide; ammonia and the like. By adjusting to the above pH range, the polymer (A) can be dissolved in the liquid medium (B) to thicken it. Further, by concentrating the polymerization mixture after the neutralization treatment, the solid content concentration can be increased while maintaining the good stability of the polymer (A).
　上記合成方法によって得られた重合混合物に中和剤を添加せずに、そのままの状態の蓄電デバイス用組成物を用いて蓄電デバイス用スラリーを調製した後、該蓄電デバイス用スラリーに中和剤を添加してｐＨを５～１１に調整することにより増粘させてもよい。この場合、蓄電デバイス用組成物は増粘していないので、蓄電デバイス用スラリーの調製が容易となる場合がある。 A slurry for a power storage device is prepared using the composition for a power storage device as it is without adding a neutralizer to the polymerization mixture obtained by the above synthesis method, and then a neutralizer is added to the slurry for the power storage device. It may be added to increase the viscosity by adjusting the pH to 5-11. In this case, since the composition for the power storage device is not thickened, it may be easy to prepare the slurry for the power storage device.
　１．２．液状媒体（Ｂ）
　本実施形態に係る蓄電デバイス用組成物は、液状媒体（Ｂ）を含有する。液状媒体（Ｂ）としては、水を含有する水系媒体であることが好ましく、水であることがより好ましい。前記水系媒体には、水以外の非水系媒体を含有させることができる。この非水系媒体としては、例えばアミド化合物、炭化水素、アルコール、ケトン、エステル、アミン化合物、ラクトン、スルホキシド、スルホン化合物などを挙げることができ、これらの中から選択される１種以上を使用することができる。本実施形態に係る蓄電デバイス用組成物は、液状媒体（Ｂ）として水系媒体を使用することにより、環境に対して悪影響を及ぼす程度が低くなり、取扱作業者に対する安全性も高くなる。 1.2. Liquid medium (B)
The composition for a power storage device according to the present embodiment contains a liquid medium (B). The liquid medium (B) is preferably an aqueous medium containing water, and more preferably water. The aqueous medium may contain a non-aqueous medium other than water. Examples of this non-aqueous medium include amide compounds, hydrocarbons, alcohols, ketones, esters, amine compounds, lactones, sulfoxides, sulfone compounds, and the like, and one or more selected from these may be used. Can be done. By using an aqueous medium as the liquid medium (B) in the composition for a power storage device according to the present embodiment, the degree of adverse effect on the environment is reduced, and the safety for the handling operator is also increased.
　水系媒体中に含まれる非水系媒体の含有割合は、水系媒体１００質量部中、１０質量部以下であることが好ましく、５質量部以下であることがより好ましく、実質的に含有しないことが特に好ましい。ここで、「実質的に含有しない」とは、液状媒体として非水系媒体を意図的に添加しないという程度の意味であり、蓄電デバイス用組成物を調製する際に不可避的に混入する非水系媒体を含んでいてもよい。 The content ratio of the non-aqueous medium contained in the aqueous medium is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and particularly preferably not substantially contained in 100 parts by mass of the aqueous medium. preferable. Here, "substantially free" means that a non-aqueous medium is not intentionally added as a liquid medium, and the non-aqueous medium is inevitably mixed when preparing a composition for a power storage device. May include.
　１．３．その他の添加剤
　本実施形態に係る蓄電デバイス用組成物は、必要に応じて上述した成分以外の添加剤を含有することができる。このような添加剤としては、例えば、重合体（Ａ）以外の重合体、防腐剤、増粘剤等が挙げられる。 1.3. Other Additives The composition for a power storage device according to the present embodiment may contain additives other than the above-mentioned components, if necessary. Examples of such additives include polymers other than the polymer (A), preservatives, thickeners and the like.
＜重合体（Ａ）以外の重合体＞
　本実施形態に係る蓄電デバイス用組成物は、重合体（Ａ）以外の重合体（以下、「重合体（Ｃ）」ともいう。）を含有してもよい。このような重合体（Ｃ）としては、特に限定されないが、ＳＢＲ（スチレンブタジエンゴム）等のスチレン－ブタジエン共重合体、不飽和カルボン酸エステルまたはこれらの誘導体を構成単位として含むアクリル系重合体、ＰＶＤＦ（ポリフッ化ビニリデン）等のフッ素系重合体等が挙げられる。これらの重合体（Ｃ）は、１種単独で用いてもよく、２種以上併用してもよい。重合体（Ｃ）を含有することにより、柔軟性や密着性がより向上する場合がある。 <Polymer other than polymer (A)>
The composition for a power storage device according to the present embodiment may contain a polymer other than the polymer (A) (hereinafter, also referred to as “polymer (C)”). Such a polymer (C) is not particularly limited, but is an acrylic polymer containing a styrene-butadiene copolymer such as SBR (styrene butadiene rubber), an unsaturated carboxylic acid ester or a derivative thereof as a constituent unit. Fluorine-based polymers such as PVDF (polyvinylidene fluoride) and the like can be mentioned. These polymers (C) may be used alone or in combination of two or more. By containing the polymer (C), flexibility and adhesion may be further improved.
　本実施形態に係る蓄電デバイス用組成物における重合体（Ａ）の含有割合は、重合体（Ａ）、重合体（Ｃ）及び増粘剤の合計１００質量部に対して、１～７０質量部であることが好ましく、１～４０質量部であることがより好ましく、２～１０質量部であることが特に好ましい。 The content ratio of the polymer (A) in the composition for a power storage device according to the present embodiment is 1 to 70 parts by mass with respect to 100 parts by mass in total of the polymer (A), the polymer (C) and the thickener. It is preferably 1 to 40 parts by mass, and particularly preferably 2 to 10 parts by mass.
　また、本実施形態に係る蓄電デバイス用組成物が重合体（Ｃ）を含有する場合、重合体（Ａ）の含有割合は、重合体（Ｃ）１００質量部に対して、５～１００質量部であることが好ましく、１０～８０質量部であることがより好ましく、１０～６０質量部であることが特に好ましい。重合体（Ａ）と重合体（Ｃ）との含有割合を前記範囲とすることにより、柔軟性や密着性を効果的に向上させることができる場合があり、特に活物質としてリチウム吸蔵量の大きい材料、例えばグラファイトのような炭素材料やケイ素材料を使用する場合に、良好な充放電耐久特性を示す蓄電デバイス電極を製造できる場合がある。 When the composition for a power storage device according to the present embodiment contains the polymer (C), the content ratio of the polymer (A) is 5 to 100 parts by mass with respect to 100 parts by mass of the polymer (C). It is preferably 10 to 80 parts by mass, and particularly preferably 10 to 60 parts by mass. By setting the content ratio of the polymer (A) and the polymer (C) within the above range, flexibility and adhesion may be effectively improved, and the amount of lithium stored as an active material is particularly large. When a material such as a carbon material such as graphite or a silicon material is used, it may be possible to manufacture a power storage device electrode exhibiting good charge / discharge durability characteristics.
＜防腐剤＞
　本実施形態に係る蓄電デバイス用組成物は、防腐剤を含有してもよい。防腐剤を含有することにより、蓄電デバイス用組成物を貯蔵した際に、細菌や黴などが増殖して異物が発生することを抑制できる場合がある。防腐剤の具体例としては、特許第５４７７６１０号公報等に記載された化合物が挙げられる。 <Preservative>
The composition for a power storage device according to the present embodiment may contain a preservative. By containing the preservative, it may be possible to suppress the growth of bacteria, mold and the like to generate foreign substances when the composition for a power storage device is stored. Specific examples of the preservative include compounds described in Japanese Patent No. 5477610.
＜増粘剤＞
　本実施形態に係る蓄電デバイス用組成物は、増粘剤を含有してもよい。増粘剤を含有することにより、その塗布性や得られる蓄電デバイスの充放電特性等をさらに向上できる場合がある。 <Thickener>
The composition for a power storage device according to the present embodiment may contain a thickener. By containing the thickener, the coatability thereof and the charge / discharge characteristics of the obtained power storage device may be further improved.
　増粘剤の具体例としては、例えばカルボキシメチルセルロース、メチルセルロース、ヒドロキシプロピルセルロース等のセルロース化合物；ポリ（メタ）アクリル酸；前記セルロース化合物又は前記ポリ（メタ）アクリル酸のアンモニウム塩もしくはアルカリ金属塩；ポリビニルアルコール、変性ポリビニルアルコール、エチレン－ビニルアルコール共重合体等のポリビニルアルコール系（共）重合体；（メタ）アクリル酸、マレイン酸、フマル酸等の不飽和カルボン酸とビニルエステルとの共重合体の鹸化物等の水溶性ポリマーを挙げることができる。これらの中でも、カルボキシメチルセルロースのアルカリ金属塩、ポリ（メタ）アクリル酸のアルカリ金属塩等が好ましい。 Specific examples of the thickener include cellulose compounds such as carboxymethyl cellulose, methyl cellulose, and hydroxypropyl cellulose; poly (meth) acrylic acid; the cellulose compound or the ammonium salt or alkali metal salt of the poly (meth) acrylic acid; polyvinyl. Polyvinyl alcohol-based (co) polymers such as alcohol, modified polyvinyl alcohol, and ethylene-vinyl alcohol copolymers; copolymers of unsaturated carboxylic acids such as (meth) acrylic acid, maleic acid, and fumaric acid and vinyl esters. Examples thereof include water-soluble polymers such as saponified products. Among these, alkali metal salts of carboxymethyl cellulose, alkali metal salts of poly (meth) acrylic acid and the like are preferable.
　本実施形態に係る蓄電デバイス用組成物が増粘剤を含有する場合、増粘剤の含有割合は、蓄電デバイス用組成物の全固形分量１００質量部に対して、５質量部以下であることが好ましく、０．１～３質量部であることがより好ましい。 When the composition for a power storage device according to the present embodiment contains a thickener, the content ratio of the thickener shall be 5 parts by mass or less with respect to 100 parts by mass of the total solid content of the composition for a power storage device. Is preferable, and 0.1 to 3 parts by mass is more preferable.
　１．４．蓄電デバイス用組成物のｐＨ
　本実施形態に係る蓄電デバイス用組成物のｐＨは、５～１１であることが好ましく、６～１１であることがより好ましく、７～１０．５であることが特に好ましい。ｐＨが前記範囲内にあると、重合体（Ａ）が液状媒体（Ｂ）に溶解することで、蓄電デバイス用組成物の粘度を高めることができる。これにより、スラリーを塗布する際にレベリング性不足や液ダレ等の問題の発生を抑制することができ、良好な電気的特性と密着性とを両立させた蓄電デバイス電極を製造することが容易となる。また、スラリーの安定性も向上する。 1.4. PH of composition for power storage device
The pH of the composition for a power storage device according to the present embodiment is preferably 5 to 11, more preferably 6 to 11, and particularly preferably 7 to 10.5. When the pH is within the above range, the polymer (A) dissolves in the liquid medium (B), so that the viscosity of the composition for a power storage device can be increased. As a result, it is possible to suppress the occurrence of problems such as insufficient leveling property and liquid dripping when applying the slurry, and it is easy to manufacture a power storage device electrode having both good electrical characteristics and adhesion. Become. It also improves the stability of the slurry.
　本明細書における「ｐＨ」とは、以下のようにして測定される物性をいう。２５℃で、ｐＨ標準液として中性リン酸塩標準液及びほう酸塩標準液で校正したガラス電極を用いたｐＨ計で、ＪＩＳ　Ｚ８８０２：２０１１に準拠して測定した値である。このようなｐＨ計としては、例えば東亜ディーケーケー株式会社製「ＨＭ－７Ｊ」や株式会社堀場製作所製「Ｄ－５１」等が挙げられる。 "PH" in the present specification refers to physical properties measured as follows. It is a value measured in accordance with JIS Z8802: 2011 with a pH meter using a glass electrode calibrated with a neutral phosphate standard solution and a borate standard solution as a pH standard solution at 25 ° C. Examples of such a pH meter include "HM-7J" manufactured by DKK-TOA CORPORATION and "D-51" manufactured by HORIBA, Ltd.
　なお、蓄電デバイス用組成物のｐＨは、重合体（Ａ）を構成する単量体組成に影響を受けることを否定しないが、単量体組成のみで定まるものではないことを付言しておく。すなわち、一般的に同じ単量体組成であっても重合条件等で蓄電デバイス用組成物のｐＨが変化することが知られており、本願明細書の実施例はその一例を示しているに過ぎない。 It should be noted that the pH of the composition for a power storage device is affected by the monomer composition constituting the polymer (A), but it is not determined only by the monomer composition. That is, it is generally known that the pH of the composition for a power storage device changes depending on the polymerization conditions and the like even if the monomer composition is the same, and the examples of the present specification show only one example. No.
　例えば、同じ単量体組成であっても、重合反応液に最初から不飽和カルボン酸を全て仕込み、その後他の単量体を順次添加して加える場合と、不飽和カルボン酸以外の単量体を重合反応液へ仕込み、最後に不飽和カルボン酸を添加する場合とでは、得られる重合体の表面に露出する不飽和カルボン酸に由来するカルボキシル基の量は異なる。このように重合方法で単量体を加える順番を変更するだけでも、蓄電デバイス用組成物のｐＨは大きく異なると考えられる。 For example, even if the polymer composition is the same, all the unsaturated carboxylic acids are charged into the polymerization reaction solution from the beginning, and then other monomers are added in sequence, or a monomer other than the unsaturated carboxylic acid is added. The amount of carboxyl groups derived from the unsaturated carboxylic acid exposed on the surface of the obtained polymer is different from that in the case of charging the polymerization reaction solution and finally adding the unsaturated carboxylic acid. It is considered that the pH of the composition for a power storage device is significantly different even if the order in which the monomers are added is changed by the polymerization method.
　２．蓄電デバイス用スラリー
　本発明の一実施形態に係る蓄電デバイス用スラリーは、上述の蓄電デバイス用組成物を含有するものである。本実施形態に係る蓄電デバイス用組成物は、上述したように、充放電に伴って発生するデンドライトに起因する短絡を抑制するための保護膜を形成するための材料として使用することもできるし、活物質同士の結合能力及び活物質と集電体との密着能力並びに粉落ち耐性を向上させた蓄電デバイス電極（活物質層）を作製するための材料として使用することもできる。そのため、保護膜を形成するための蓄電デバイス用スラリー（以下、「保護膜形成用スラリー」ともいう。）と、蓄電デバイス電極の活物質層を形成するための蓄電デバイス用スラリー（以下、「蓄電デバイス電極用スラリー」ともいう。）とに分けて説明する。 2. Slurry for power storage device The slurry for power storage device according to the embodiment of the present invention contains the above-mentioned composition for power storage device. As described above, the composition for a power storage device according to the present embodiment can be used as a material for forming a protective film for suppressing a short circuit caused by dendrites generated during charging and discharging. It can also be used as a material for producing a power storage device electrode (active material layer) having improved binding ability between active materials, adhesion ability between the active material and a current collector, and powder drop resistance. Therefore, a slurry for a power storage device for forming a protective film (hereinafter, also referred to as a “slurry for forming a protective film”) and a slurry for a power storage device for forming an active material layer of a power storage device electrode (hereinafter, “storage”). It is also referred to as "device electrode slurry").
　２．１．保護膜形成用スラリー
　本明細書における「保護膜形成用スラリー」とは、これを電極またはセパレータの表面もしくはその両方に塗布した後、乾燥させて、電極またはセパレータの表面もしくはその両方に保護膜を形成するために用いられる溶液または分散液のことをいう。本実施形態に係る保護膜形成用スラリーは、上述した蓄電デバイス用組成物のみから構成されていてもよく、無機フィラーをさらに含有してもよい。以下、本実施形態に係る保護膜形成用スラリーに含まれる各成分について詳細に説明する。なお、蓄電デバイス用組成物については、上述した通りであるので説明を省略する。 2.1. Slurry for forming a protective film The term "slurry for forming a protective film" as used herein refers to a slurry for forming a protective film, which is applied to the surface of an electrode or a separator or both, and then dried to apply a protective film to the surface of an electrode or a separator or both. A solution or dispersion used to form. The slurry for forming a protective film according to the present embodiment may be composed only of the above-mentioned composition for a power storage device, or may further contain an inorganic filler. Hereinafter, each component contained in the protective film forming slurry according to the present embodiment will be described in detail. Since the composition for the power storage device is as described above, the description thereof will be omitted.
　２．１．１．無機フィラー
　本実施形態に係る保護膜形成用スラリーは、無機フィラーを含有することにより、形成される保護膜のタフネスを向上させることができる。無機フィラーとしては、シリカ、酸化チタン（チタニア）、酸化アルミニウム（アルミナ）、酸化ジルコニウム（ジルコニア）、及び酸化マグネシウム（マグネシア）からなる群より選択される少なくとも１種の粒子を用いることが好ましい。これらの中でも、保護膜のタフネスをより向上させる観点から、酸化チタン、酸化アルミニウムが好ましい。また、酸化チタンとしてはルチル型の酸化チタンがより好ましい。 2.1.1. Inorganic filler The slurry for forming a protective film according to the present embodiment can improve the toughness of the protective film formed by containing the inorganic filler. As the inorganic filler, it is preferable to use at least one kind of particles selected from the group consisting of silica, titanium oxide (titania), aluminum oxide (alumina), zirconium oxide (zirconia), and magnesium oxide (magnesia). Among these, titanium oxide and aluminum oxide are preferable from the viewpoint of further improving the toughness of the protective film. Further, as the titanium oxide, rutile type titanium oxide is more preferable.
　無機フィラーの平均粒子径は、１μｍ以下であることが好ましく、０．１～０．８μｍの範囲内であることがより好ましい。なお、無機フィラーの平均粒子径は、多孔質膜であるセパレータの平均孔径よりも大きいことが好ましい。これにより、セパレータへのダメージを軽減し、無機フィラーがセパレータの微多孔に詰まることを防ぐことができる。 The average particle size of the inorganic filler is preferably 1 μm or less, more preferably 0.1 to 0.8 μm. The average particle size of the inorganic filler is preferably larger than the average pore size of the separator which is a porous film. This can reduce damage to the separator and prevent the inorganic filler from clogging the microporous separator.
　本実施形態に係る保護膜形成用スラリーは、無機フィラー１００質量部に対して、上述の蓄電デバイス用組成物が、固形分換算で０．１～２０質量部含有されていることが好ましく、１～１０質量部含有されていることがより好ましい。蓄電デバイス用組成物の含有割合が前記範囲であることにより、形成される保護膜のタフネスとリチウムイオンの透過性とのバランスが良好となり、その結果、得られる蓄電デバイスの抵抗上昇率をより低くすることができる。 The slurry for forming a protective film according to the present embodiment preferably contains 0.1 to 20 parts by mass of the above-mentioned composition for a power storage device in terms of solid content with respect to 100 parts by mass of the inorganic filler. More preferably, it is contained in an amount of about 10 parts by mass. When the content ratio of the composition for the power storage device is within the above range, the balance between the toughness of the protective film formed and the permeability of lithium ions is good, and as a result, the resistance increase rate of the obtained power storage device is lowered. can do.
　２．１．２．液状媒体
　本実施形態に係る保護膜形成用スラリーは、液状媒体をさらに含有してもよく、上述の蓄電デバイス用組成物の「１．２．液状媒体（Ｂ）」の項に記載されている材料を必要に応じて用いることができる。液状媒体の添加量は、塗工方法等に応じて最適なスラリーの粘度が得られるように、必要に応じて調整することができる。 2.1.2. Liquid medium The slurry for forming a protective film according to the present embodiment may further contain a liquid medium, and is described in the section "1.2. Liquid medium (B)" of the above-mentioned composition for a power storage device. The material can be used as needed. The amount of the liquid medium added can be adjusted as necessary so that the optimum viscosity of the slurry can be obtained according to the coating method and the like.
　２．１．３．その他の成分
　本実施形態に係る保護膜形成用スラリーは、上述の蓄電デバイス用組成物の「１．３．その他の添加剤」の項に記載されている材料を必要に応じて適量用いることができる。 2.1.3. Other Ingredients For the protective film-forming slurry according to the present embodiment, an appropriate amount of the material described in the section "1.3. Other additives" of the above-mentioned composition for power storage device may be used as needed. can.
　２．２．蓄電デバイス電極用スラリー
　本明細書における「蓄電デバイス電極用スラリー」とは、これを集電体の表面に塗布した後、乾燥させて、集電体表面上に活物質層を形成するために用いられる分散液のことをいう。本実施形態に係る蓄電デバイス電極用スラリーは、上述の蓄電デバイス用組成物と、活物質と、を含有する。 2.2. Slurry for power storage device electrodes The term "slurry for power storage device electrodes" as used herein is used to apply this to the surface of a current collector and then dry it to form an active material layer on the surface of the current collector. It refers to the dispersion liquid that is produced. The slurry for a power storage device electrode according to the present embodiment contains the above-mentioned composition for a power storage device and an active material.
　一般的に、蓄電デバイス電極用スラリーは、密着性を向上させるために、ＳＢＲ系共重合体などのバインダー成分と、カルボキシメチルセルロース等の増粘剤とを含有することが多い。一方、本実施形態に係る蓄電デバイス電極用スラリーは、上述した重合体（Ａ）のみでも柔軟性及び密着性を向上させることができる。もちろん、本実施形態に係る蓄電デバイス電極用スラリーは、さらに密着性を向上させるために、重合体（Ａ）以外の重合体や増粘剤を含有してもよい。 In general, a slurry for a power storage device electrode often contains a binder component such as an SBR-based copolymer and a thickener such as carboxymethyl cellulose in order to improve adhesion. On the other hand, the slurry for the power storage device electrode according to the present embodiment can improve the flexibility and the adhesiveness only by the above-mentioned polymer (A). Of course, the slurry for the power storage device electrode according to the present embodiment may contain a polymer other than the polymer (A) or a thickener in order to further improve the adhesion.
　２．２．１．重合体（Ａ）
　重合体（Ａ）の組成、特性、製造方法については、上述した通りであるので、説明を省略する。本実施形態に係る蓄電デバイス電極用スラリー中の重合体（Ａ）の含有割合は、活物質１００質量部に対し、１～８質量部であることが好ましく、１～７質量部であることがより好ましく、１．５～６質量部であることが特に好ましい。重合体（Ａ）の含有割合が前記範囲にあると、スラリー中の活物質の分散性が良好となり、スラリーの塗布性も優れたものとなる。本実施形態に係る蓄電デバイス電極用スラリーが、重合体（Ａ）以外の重合体や増粘剤を含有する場合も同様である。 2.2.1. Polymer (A)
The composition, properties, and production method of the polymer (A) are as described above, and thus the description thereof will be omitted. The content ratio of the polymer (A) in the slurry for the power storage device electrode according to the present embodiment is preferably 1 to 8 parts by mass and 1 to 7 parts by mass with respect to 100 parts by mass of the active material. It is more preferably 1.5 to 6 parts by mass, and particularly preferably 1.5 to 6 parts by mass. When the content ratio of the polymer (A) is within the above range, the dispersibility of the active material in the slurry becomes good, and the coatability of the slurry becomes also excellent. The same applies when the slurry for the power storage device electrode according to the present embodiment contains a polymer other than the polymer (A) or a thickener.
　２．２．２．活物質
　本実施形態に係る蓄電デバイス電極用スラリーに使用される活物質としては、例えば炭素材料、ケイ素材料、リチウム原子を含む酸化物、鉛化合物、錫化合物、砒素化合物、アンチモン化合物、アルミニウム化合物などが挙げられる。これらの具体例としては、特許第５９９９３９９号公報等に記載された化合物が挙げられる。 2.2.2. Active material Examples of the active material used in the slurry for the power storage device electrode according to the present embodiment include a carbon material, a silicon material, an oxide containing a lithium atom, a lead compound, a tin compound, an arsenic compound, an antimony compound, and an aluminum compound. Can be mentioned. Specific examples of these include compounds described in Japanese Patent No. 5999399.
　また、活物質層中には、以下に例示する活物質を含んでもよい。例えばポリアセン等の導電性高分子；ＡＸＢＹＯＺ（但し、Ａはアルカリ金属または遷移金属、Ｂはコバルト、ニッケル、アルミニウム、スズ、マンガン等の遷移金属から選択される少なくとも１種、Ｏは酸素原子を表し、Ｘ、Ｙ及びＺはそれぞれ１．１０＞Ｘ＞０．０５、４．００＞Ｙ＞０．８５、５．００＞Ｚ＞１．５の範囲の数である。）で表される複合金属酸化物や、その他の金属酸化物等が挙げられる。 Further, the active material layer may contain the active material exemplified below. For example conductive polymers such as polyacene; A X B Y O Z (where, A is an alkali metal or a transition metal, B is cobalt, nickel, aluminum, tin, at least one selected from the transition metals manganese, O Represents an oxygen atom, where X, Y and Z are numbers in the range 1.10>X> 0.05, 4.00>Y> 0.85 and 5.00>Z> 1.5, respectively.) Examples thereof include composite metal oxides represented by and other metal oxides.
　本実施形態に係る蓄電デバイス電極用スラリーは、正極及び負極のいずれの蓄電デバイス電極を作製する際にも使用することができ、正極及び負極の両方に使用することが好ましい。 The slurry for the power storage device electrode according to the present embodiment can be used when producing any power storage device electrode of the positive electrode and the negative electrode, and is preferably used for both the positive electrode and the negative electrode.
　正極活物質としてリン酸鉄リチウムを使用する場合、充放電特性が十分ではなく密着性が劣るという課題があった。リン酸鉄リチウムは、微細な一次粒径を有し、その二次凝集体であることが知られており、充放電を繰り返す際に活物質層中で凝集が崩壊し活物質同士の剥離を引き起こし、集電体からの剥離や、活物質層内部の導電ネットワークが寸断されやすいことが要因の一つであると考えられる。 When lithium iron phosphate was used as the positive electrode active material, there was a problem that the charge / discharge characteristics were not sufficient and the adhesion was inferior. Lithium iron phosphate has a fine primary particle size and is known to be a secondary aggregate thereof. When charging and discharging are repeated, the aggregation collapses in the active material layer and the active materials are separated from each other. It is considered that one of the causes is that it is easily peeled off from the current collector and the conductive network inside the active material layer is easily broken.
　しかしながら、本実施形態に係る蓄電デバイス電極用スラリーを用いて作製された蓄電デバイス電極では、リン酸鉄リチウムを使用した場合でも上述のような問題が発生することなく、良好な電気的特性を示すことができる。この理由としては、重合体（Ａ）がリン酸鉄リチウムを強固に結着させることができると同時に、充放電中においてもリン酸鉄リチウムを強固に結着させた状態を維持できるからであると考えられる。 However, the power storage device electrode produced by using the slurry for the power storage device electrode according to the present embodiment exhibits good electrical characteristics without causing the above-mentioned problems even when lithium iron phosphate is used. be able to. The reason for this is that the polymer (A) can firmly bind lithium iron phosphate, and at the same time, it can maintain a state in which lithium iron phosphate is firmly bound even during charging and discharging. it is conceivable that.
　一方、負極を作製する場合には、上記例示した活物質の中でもケイ素材料を含有するものであることが好ましい。ケイ素材料は単位重量当たりのリチウムの吸蔵量がその他の活物質と比較して大きいことから、負極活物質としてのケイ素材料を含有することにより、得られる蓄電デバイスの蓄電容量を高めることができ、その結果、蓄電デバイスの出力及びエネルギー密度を高くすることができる。 On the other hand, when producing a negative electrode, it is preferable that the active material exemplified above contains a silicon material. Since the silicon material has a large occlusion amount of lithium per unit weight as compared with other active materials, the storage capacity of the obtained power storage device can be increased by containing the silicon material as the negative electrode active material. As a result, the output and energy density of the power storage device can be increased.
　また、負極活物質としては、ケイ素材料と炭素材料との混合物であることがより好ましい。炭素材料は充放電に伴う体積変化が小さいから、負極活物質としてケイ素材料と炭素材料との混合物を使用することにより、ケイ素材料の体積変化の影響を緩和することができ、活物質層と集電体との密着能力をより向上させることができる。 Further, the negative electrode active material is more preferably a mixture of a silicon material and a carbon material. Since the volume change of the carbon material due to charge and discharge is small, the influence of the volume change of the silicon material can be mitigated by using a mixture of the silicon material and the carbon material as the negative electrode active material, and the active material layer and the collection. The ability to adhere to the electric body can be further improved.
　シリコン（Ｓｉ）を活物質として使用する場合、シリコンは、高容量である一方、リチウムを吸蔵する際に大きな体積変化を生じる。このため、ケイ素材料は膨張と収縮の繰り返しによって微粉化、集電体からの剥離や、活物質同士の剥離を引き起こし、活物質層内部の導電ネットワークが寸断されやすいという性質がある。これにより、短時間でサイクル特性が極端に劣化してしまうのである。 When silicon (Si) is used as an active material, silicon has a high capacity, but causes a large volume change when it occludes lithium. For this reason, the silicon material has a property that the conductive network inside the active material layer is easily broken by causing micronization, peeling from the current collector, and peeling between the active materials by repeating expansion and contraction. As a result, the cycle characteristics are extremely deteriorated in a short time.
　しかしながら、本実施形態に係る蓄電デバイス電極用スラリーを用いて作製された蓄電デバイス電極では、ケイ素材料を使用した場合でも上述のような問題が発生することなく、良好な電気的特性を示すことができる。この理由としては、重合体（Ａ）がケイ素材料を強固に結着させることができると同時に、リチウムを吸蔵することによりケイ素材料が体積膨張しても重合体（Ａ）が伸び縮みしてケイ素材料を強固に結着させた状態を維持できるからであると考えられる。 However, the power storage device electrode produced by using the slurry for the power storage device electrode according to the present embodiment can exhibit good electrical characteristics without causing the above-mentioned problems even when a silicon material is used. can. The reason for this is that the polymer (A) can firmly bind the silicon material, and at the same time, the polymer (A) expands and contracts even if the silicon material expands in volume due to occlusion of lithium, resulting in silicon. It is considered that this is because the material can be maintained in a tightly bound state.
　活物質１００質量％中に占めるケイ素材料の含有割合は、１質量％以上とすることが好ましく、１～５０質量％とすることがより好ましく、５～４５質量％とすることがさらに好ましく、１０～４０質量％とすることが特に好ましい。活物質１００質量％中に占めるケイ素材料の含有割合が前記範囲内であると、蓄電デバイスの出力及びエネルギー密度の向上と充放電耐久特性とのバランスに優れた蓄電デバイスが得られる。 The content ratio of the silicon material in 100% by mass of the active material is preferably 1% by mass or more, more preferably 1 to 50% by mass, further preferably 5 to 45% by mass, and 10%. It is particularly preferable to set it to 40% by mass. When the content ratio of the silicon material in 100% by mass of the active material is within the above range, a power storage device having an excellent balance between the improvement of the output and energy density of the power storage device and the charge / discharge durability characteristics can be obtained.
　活物質の形状としては、粒状であることが好ましい。活物質の平均粒子径としては、０．１～１００μｍであることが好ましく、１～２０μｍであることがより好ましい。ここで、活物質の平均粒子径とは、レーザー回折法を測定原理とする粒度分布測定装置を用いて粒度分布を測定し、その粒度分布から算出される体積平均粒子径である。このようなレーザー回折式粒度分布測定装置としては、例えばＨＯＲＩＢＡ　ＬＡ－３００シリーズ、ＨＯＲＩＢＡ　ＬＡ－９２０シリーズ（以上、株式会社堀場製作所製）などを挙げることができる。 The shape of the active material is preferably granular. The average particle size of the active material is preferably 0.1 to 100 μm, more preferably 1 to 20 μm. Here, the average particle size of the active material is a volume average particle size calculated from the particle size distribution measured by using a particle size distribution measuring device based on a laser diffraction method. Examples of such a laser diffraction type particle size distribution measuring device include the HORIBA LA-300 series and the HORIBA LA-920 series (all manufactured by HORIBA, Ltd.).
　２．２．３．その他の成分
　本実施形態に係る蓄電デバイス電極用スラリーには、上述した成分以外に、必要に応じてその他の成分を添加してもよい。このような成分としては、例えば重合体（Ａ）以外の重合体、増粘剤、導電付与剤、液状媒体（但し、蓄電デバイス用組成物からの持ち込み分を除く。）、ｐＨ調整剤、腐食防止剤などが挙げられる。重合体（Ａ）以外の重合体及び増粘剤としては、上述の「１．３．その他の添加剤」の項で例示した化合物の中から選択して、同様の目的及び含有割合で用いることができる。導電付与剤としては、特許第５９９９３９９号公報等に記載された化合物が挙げられる。 2.2.3. Other Components In addition to the above-mentioned components, other components may be added to the slurry for the power storage device electrode according to the present embodiment, if necessary. Examples of such components include polymers other than the polymer (A), thickeners, conductivity-imparting agents, liquid media (excluding those brought in from the composition for power storage devices), pH adjusters, and corrosion. Examples include preventive agents. As the polymer and thickener other than the polymer (A), select from the compounds exemplified in the above section "1.3. Other additives" and use them for the same purpose and content ratio. Can be done. Examples of the conductivity-imparting agent include compounds described in Japanese Patent No. 5999399.
＜液状媒体＞
　本実施形態に係る蓄電デバイス電極用スラリーに追加で添加し得る液状媒体は、蓄電デバイス用組成物に含まれていた液状媒体（Ｂ）と同種であってもよく、異なっていてもよいが、上述の「１．２．液状媒体（Ｂ）」の項で例示した液状媒体の中から選択して使用されることが好ましい。 <Liquid medium>
The liquid medium that can be additionally added to the slurry for the power storage device electrode according to the present embodiment may be the same as or different from the liquid medium (B) contained in the composition for the power storage device. It is preferable to select and use the liquid medium exemplified in the above section "1.2. Liquid medium (B)".
　本実施形態に係る蓄電デバイス電極用スラリーにおける液状媒体（蓄電デバイス用組成物からの持ち込み分を含む。）の使用割合は、スラリー中の固形分濃度（スラリー中の液状媒体以外の成分の合計質量がスラリーの全質量に占める割合をいう。以下同じ。）が、３０～７０質量％となる割合とすることが好ましく、４０～６０質量％となる割合とすることがより好ましい。 The ratio of the liquid medium (including the amount brought in from the composition for the power storage device) in the slurry for the power storage device electrode according to the present embodiment is the solid content concentration in the slurry (the total mass of the components other than the liquid medium in the slurry). Refers to the ratio of the slurry to the total mass. The same shall apply hereinafter) is preferably a ratio of 30 to 70% by mass, and more preferably 40 to 60% by mass.
＜ｐＨ調整剤・腐食防止剤＞
　本実施形態に係る蓄電デバイス電極用スラリーは、活物質の種類に応じて集電体の腐食を抑制することを目的として、ｐＨ調整剤及び／又は腐食防止剤を含有することができる。 <pH adjuster / corrosion inhibitor>
The slurry for a power storage device electrode according to the present embodiment may contain a pH adjuster and / or a corrosion inhibitor for the purpose of suppressing corrosion of the current collector according to the type of active material.
　ｐＨ調整剤としては、例えば、塩酸、リン酸、硫酸、酢酸、ギ酸、リン酸アンモニウム、硫酸アンモニウム、酢酸アンモニウム、ギ酸アンモニウム、塩化アンモニウム、水酸化ナトリウム、水酸化カリウムなどを挙げることでき、これらの中でも硫酸、硫酸アンモニウム、水酸化ナトリウム、水酸化カリウムが好ましい。また、重合体（Ａ）の製造方法中に記載された化合物の中から選択して使用することもできる。 Examples of the pH adjuster include hydrochloric acid, phosphoric acid, sulfuric acid, acetic acid, formic acid, ammonium phosphate, ammonium sulfate, ammonium acetate, ammonium formate, ammonium chloride, sodium hydroxide, potassium hydroxide and the like. Sulfate, ammonium sulfate, sodium hydroxide and potassium hydroxide are preferred. Further, it can be selected and used from the compounds described in the method for producing the polymer (A).
　腐食防止剤としては、メタバナジン酸アンモニウム、メタバナジン酸ナトリウム、メタバナジン酸カリウム、メタタングステン酸アンモニウム、メタタングステン酸ナトリウム、メタタングステン酸カリウム、パラタングステン酸アンモニウム、パラタングステン酸ナトリウム、パラタングステン酸カリウム、モリブデン酸アンモニウム、モリブデン酸ナトリウム、モリブデン酸カリウムなどが挙げられ、これらの中でもパラタングステン酸アンモニウム、メタバナジン酸アンモニウム、メタバナジン酸ナトリウム、メタバナジン酸カリウム、モリブデン酸アンモニウムが好ましい。 Corrosion inhibitors include ammonium metavanadate, sodium metavanadate, potassium metavanadate, ammonium metatungstate, sodium metatungstate, potassium metatungstate, ammonium paratungstate, sodium paratungstate, potassium paratungstate, molybdate. Examples thereof include ammonium, sodium molybdate, and potassium molybdate. Among these, ammonium paratungstate, ammonium metavanadate, sodium metavanadate, potassium metavanadate, and ammonium molybdate are preferable.
　２．２．４．蓄電デバイス電極用スラリーの調製方法
　本実施形態に係る蓄電デバイス電極用スラリーは、上述の蓄電デバイス用組成物と活物質とを含有するものである限り、どのような方法によって製造されたものであってもよいが、例えば特許第５９９９３９９号公報等に記載されている方法により製造することができる。 2.2.4. Method for Preparing Slurry for Power Storage Device Electrode The slurry for power storage device electrode according to the present embodiment is produced by any method as long as it contains the above-mentioned composition for power storage device and an active material. However, it can be produced by the method described in, for example, Japanese Patent No. 5999399.
　３．蓄電デバイス電極
　本発明の一実施形態に係る蓄電デバイス電極は、集電体と、前記集電体の表面上に上述の蓄電デバイス電極用スラリーが塗布及び乾燥されて形成された活物質層と、を備えるものである。かかる蓄電デバイス電極は、金属箔などの集電体の表面に、上述の蓄電デバイス電極用スラリーを塗布して塗膜を形成し、次いで該塗膜を乾燥して活物質層を形成することにより製造することができる。このようにして製造された蓄電デバイス電極は、集電体上に、上述の重合体（Ａ）及び活物質、さらに必要に応じて添加した任意成分を含有する活物質層が結着されてなるものであるから、柔軟性及び密着性に優れるとともに、良好な充放電耐久特性を示す。 3. 3. Storage device electrode The power storage device electrode according to an embodiment of the present invention includes a current collector, an active material layer formed by applying and drying the above-mentioned storage device electrode slurry on the surface of the current collector. Is provided. Such a power storage device electrode is formed by applying the above-mentioned slurry for a power storage device electrode to the surface of a current collector such as a metal foil to form a coating film, and then drying the coating film to form an active material layer. Can be manufactured. The power storage device electrode produced in this manner is formed by bonding an active material layer containing the above-mentioned polymer (A), an active material, and an optional component added as needed, on a current collector. Therefore, it is excellent in flexibility and adhesion, and exhibits good charge / discharge durability characteristics.
　集電体としては、導電性材料からなるものであれば特に制限されないが、例えば特許第５９９９３９９号公報等に記載されている集電体が挙げられる。 The current collector is not particularly limited as long as it is made of a conductive material, and examples thereof include the current collector described in Japanese Patent No. 5999399.
　蓄電デバイス電極用スラリーの集電体への塗布方法についても特に制限はなく、例えば特許第５９９９３９９号公報等に記載されている方法により塗布することができる。このようにして製造された蓄電デバイス電極は、柔軟性及び密着性に優れるとともに、良好な充放電耐久特性を示す。 There is no particular limitation on the method of applying the slurry for the power storage device electrode to the current collector, and the slurry can be applied by the method described in, for example, Japanese Patent No. 5999399. The power storage device electrode manufactured in this manner is excellent in flexibility and adhesion, and exhibits good charge / discharge durability characteristics.
　本実施形態に係る蓄電デバイス電極において、活物質としてケイ素材料を用いる場合、活物質層１００質量部中のシリコン元素の含有割合が、２～３０質量部であることが好ましく、３～２５質量部であることがより好ましい。活物質層中のシリコン元素の含有量が前記範囲内であると、それを用いて作製される蓄電デバイスの蓄電容量が向上することに加え、シリコン元素の分布が均一な活物質層が得られる。本発明において活物質層中のシリコン元素の含有量は、例えば特許第５９９９３９９号公報等に記載された方法により測定することができる。 When a silicon material is used as the active material in the power storage device electrode according to the present embodiment, the content ratio of the silicon element in 100 parts by mass of the active material layer is preferably 2 to 30 parts by mass, and 3 to 25 parts by mass. Is more preferable. When the content of the silicon element in the active material layer is within the above range, in addition to improving the storage capacity of the power storage device produced by using the silicon element, an active material layer having a uniform distribution of silicon elements can be obtained. .. In the present invention, the content of the silicon element in the active material layer can be measured by, for example, the method described in Japanese Patent No. 5999399.
　４．蓄電デバイス
　本発明の一実施形態に係る蓄電デバイスは、上述の蓄電デバイス電極を備え、さらに電解液を含有し、セパレータなどの部品を用いて、常法に従って製造することができる。具体的な製造方法としては、例えば、負極と正極とをセパレータを介して重ね合わせ、これを電池形状に応じて巻く、折るなどして電池容器に収納し、該電池容器に電解液を注入して封口する方法などを挙げることができる。電池の形状は、コイン型、円筒型、角形、ラミネート型など、適宜の形状であることができる。 4. Power storage device The power storage device according to the embodiment of the present invention can be manufactured according to a conventional method by providing the above-mentioned power storage device electrode, further containing an electrolytic solution, and using parts such as a separator. As a specific manufacturing method, for example, a negative electrode and a positive electrode are overlapped with each other via a separator, and the negative electrode and the positive electrode are stored in a battery container by winding or folding according to the shape of the battery, and an electrolytic solution is injected into the battery container. The method of sealing the battery can be mentioned. The shape of the battery can be an appropriate shape such as a coin type, a cylindrical type, a square type, or a laminated type.
　電解液は、液状でもゲル状でもよく、活物質の種類に応じて、蓄電デバイスに用いられる公知の電解液の中から電池としての機能を効果的に発現するものを選択すればよい。電解液は、電解質を適当な溶媒に溶解した溶液であることができる。これら電解質や溶媒については、例えば、特許第５９９９３９９号公報等に記載された化合物が挙げられる。 The electrolytic solution may be in the form of a liquid or a gel, and depending on the type of the active material, a known electrolytic solution used in the power storage device that effectively exhibits the function as a battery may be selected. The electrolytic solution can be a solution in which the electrolyte is dissolved in a suitable solvent. Examples of these electrolytes and solvents include compounds described in Japanese Patent No. 5999399.
　５．実施例
　以下、本発明を実施例に基づいて具体的に説明するが、本発明はこれらの実施例に限定されるものではない。実施例、比較例中の「部」及び「％」は、特に断らない限り質量基準である。 5. Examples Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" and "%" in Examples and Comparative Examples are based on mass.
　５．１．実施例１
　５．１．１．蓄電デバイス用組成物の調製及び粘度測定
（１）蓄電デバイス用組成物の調製
　１００Ｌオートクレーブに、水９００質量部、過硫酸ナトリウム０．１質量部、ドデシルベンゼンスルホン酸０．５質量部、４－ビニル－１，３－ジオキソラン－２－オン５質量部、アクリル酸２０質量部、アクリルアミド３２質量部、メタクリルアミド４３質量部を加え、７０℃で１８時間反応を行った。その後、冷却し、５ｗｔ％水酸化ナトリウム水溶液を用いて、ｐＨ７．０となるように調整した。その後、残留単量体を水蒸気蒸留によって除去し、減圧下で濃縮することにより、重合体（Ａ１）を１０質量％含有するｐＨ７．０の蓄電デバイス用組成物を得た。なお、ｐＨの調整は、ｐＨメーター（株式会社堀場製作所製）を用いて２５℃においてｐＨを測定しながら、５ｗｔ％水酸化ナトリウム水溶液を滴下することにより行った。 5.1. Example 1
5.1.1. Preparation of composition for power storage device and measurement of viscosity (1) Preparation of composition for power storage device In a 100 L autoclave, 900 parts by mass of water, 0.1 part by mass of sodium persulfate, 0.5 part by mass of dodecylbenzene sulfonic acid, 4- 5 parts by mass of vinyl-1,3-dioxolan-2-one, 20 parts by mass of acrylic acid, 32 parts by mass of acrylamide, and 43 parts by mass of methacrylicamide were added, and the reaction was carried out at 70 ° C. for 18 hours. Then, it was cooled and adjusted to pH 7.0 using a 5 wt% sodium hydroxide aqueous solution. Then, the residual monomer was removed by steam distillation and concentrated under reduced pressure to obtain a composition for a storage device having a pH of 7.0 containing 10% by mass of the polymer (A1). The pH was adjusted by dropping a 5 wt% sodium hydroxide aqueous solution while measuring the pH at 25 ° C. using a pH meter (manufactured by HORIBA, Ltd.).
（２）粘度測定
　上記で得られた蓄電デバイス用組成物について、重合体（Ａ１）が１０質量％となるように水を加え、５ｗｔ％水酸化ナトリウム水溶液を滴下してｐＨが９．０となるように調整した。このようにして得られた蓄電デバイス用組成物について、Ｂ型粘度計を用いて２５℃における粘度を測定した。その結果を下表１に示す。 (2) Viscosity measurement With respect to the composition for a power storage device obtained above, water was added so that the polymer (A1) was 10% by mass, and a 5 wt% sodium hydroxide aqueous solution was added dropwise to bring the pH to 9.0. Adjusted to be. The viscosity of the composition for a power storage device thus obtained was measured at 25 ° C. using a B-type viscometer. The results are shown in Table 1 below.
（３）数平均分子量の測定
　上記で得られた蓄電デバイス用組成物について、ＧＰＣを用いて分子量を測定したところ、数平均分子量は１５０，０００であった。なお、測定条件は以下の通りとした。
（測定条件）
・測定機器：東ソー株式会社製、ＧＰＣ（型番：ＨＬＣ－８２２０）
・カラム：ＴＳＫｇｅｌ　ｇｕａｒｄｃｏｌｕｍ　ＰＷＸＬ（東ソー株式会社製）、ＴＳＫ－ＧＥＬ　Ｇ２５００ＰＷＸＬ（東ソー株式会社製）、ＴＳＫ－ＧＥＬ　ＧＭＰＷＸＬ（東ソー株式会社製）
・溶離液：０．１Ｍ　ＮａＮＯ３水溶液
・検量線：標準ポリエチレンオキシド
・測定方法：重合体（Ａ）の固形分が０．３ｗｔ％となるように溶離液に溶解し、フィルターろ過後に測定する。 (3) Measurement of Number Average Molecular Weight When the molecular weight of the composition for a power storage device obtained above was measured using GPC, the number average molecular weight was 150,000. The measurement conditions were as follows.
(Measurement condition)
-Measuring equipment: GPC (model number: HLC-8220) manufactured by Tosoh Corporation
-Column: TSKgel guardcolum PW XL (manufactured by Tosoh Co., Ltd.), TSK-GEL G2500PW XL (manufactured by Tosoh Co., Ltd.), TSK-GEL GMPW XL (manufactured by Tosoh Co., Ltd.)
-Eluent: 0.1 M NaNO 3 aqueous solution-Calibration curve: Standard polyethylene oxide-Measurement method: Dissolve the polymer (A) in the eluent so that the solid content is 0.3 wt%, and measure after filtering.
　５．１．２．蓄電デバイス電極用スラリーの調製
（１）ケイ素材料（活物質）の合成
　粉砕した二酸化ケイ素粉末（平均粒子径１０μｍ）と炭素粉末（平均粒子径３５μｍ）との混合物を、温度を１１００℃～１６００℃の範囲に調整した電気炉中で、窒素気流下（０．５ＮＬ／分）、１０時間の加熱処理を行い、組成式ＳｉＯｘ（ｘ＝０．５～１．１）で表される酸化ケイ素の粉末（平均粒子径８μｍ）を得た。この酸化ケイ素の粉末３００ｇをバッチ式加熱炉内に仕込み、真空ポンプにより絶対圧１００Ｐａの減圧を維持しながら、３００℃／ｈの昇温速度にて室温（２５℃）から１１００℃まで昇温した。次いで、加熱炉内の圧力を２０００Ｐａに維持しつつ、メタンガスを０．５ＮＬ／分の流速にて導入しながら、１１００℃、５時間の加熱処理（黒鉛被膜処理）を行った。黒鉛被膜処理終了後、５０℃／ｈの降温速度で室温まで冷却することにより、黒鉛被膜酸化ケイ素の粉末約３３０ｇを得た。この黒鉛被膜酸化ケイ素は、酸化ケイ素の表面が黒鉛で被覆された導電性の粉末（活物質）であり、その平均粒子径は１０．５μｍであり、得られた黒鉛被膜酸化ケイ素の全体を１００質量％とした場合の黒鉛被膜の割合は２質量％であった。 5.1.2. Preparation of slurry for power storage device electrode (1) Synthesis of silicon material (active material) A mixture of crushed silicon dioxide powder (average particle size 10 μm) and carbon powder (average particle size 35 μm) is heated at a temperature of 1100 ° C to 1600 ° C. Silicon oxide represented by the composition formula SiO x (x = 0.5 to 1.1) after heat treatment for 10 hours under a nitrogen stream (0.5 NL / min) in an electric furnace adjusted to the range of Powder (average particle size 8 μm) was obtained. 300 g of this silicon oxide powder was charged into a batch type heating furnace, and the temperature was raised from room temperature (25 ° C.) to 1100 ° C. at a heating rate of 300 ° C./h while maintaining a reduced pressure of 100 Pa by a vacuum pump. .. Next, while maintaining the pressure in the heating furnace at 2000 Pa, heat treatment (graphite coating treatment) was performed at 1100 ° C. for 5 hours while introducing methane gas at a flow rate of 0.5 NL / min. After the graphite coating treatment was completed, the mixture was cooled to room temperature at a temperature lowering rate of 50 ° C./h to obtain about 330 g of graphite-coated silicon oxide powder. This graphite-coated silicon oxide is a conductive powder (active material) whose surface is coated with graphite, and its average particle size is 10.5 μm. The proportion of the graphite coating in the mass% was 2% by mass.
（２）蓄電デバイス電極用スラリーの調製
　二軸型プラネタリーミキサー（プライミクス株式会社製、商品名「ＴＫハイビスミックス　２Ｐ－０３」）に重合体（Ａ１）を０．２質量部（固形分換算値、上記で得られた重合体（Ａ１）を１０質量％含有するｐＨ７．０の蓄電デバイス用組成物として添加）、増粘剤（商品名「ＣＭＣ２２００」、株式会社ダイセル製）を１．０質量部、負極活物質として結晶性の高いグラファイトである人造黒鉛（昭和電工マテリアルズ株式会社製、商品名「ＭＡＧ」）７７質量部（固形分換算値）、上記で得られた黒鉛被膜酸化ケイ素の粉末を１９質量部（固形分換算値）、導電付与剤であるカーボン（デンカ株式会社製、アセチレンブラック）を１質量部投入し、６０ｒｐｍで１時間攪拌を行い、ペーストを得た。得られたペーストにＳＢＲ（ＪＳＲ株式会社製、商品名「ＴＲＤ１０５Ａ」）を１．８質量部（固形換算値）、水を投入し、固形分濃度を４８質量％に調整した後、攪拌脱泡機（株式会社シンキー製、商品名「泡とり練太郎」）を使用して、２００ｒｐｍで２分間、１，８００ｒｐｍで５分間、さらに減圧下（約２．５×１０４Ｐａ）において１，８００ｒｐｍで１．５分間攪拌混合することにより、負極活物質中にＳｉを２０質量％含有する蓄電デバイス電極用スラリー（Ｃ／Ｓｉ＝８０／２０）を調製した。 (2) Preparation of slurry for power storage device electrode 0.2 parts by mass (solid content conversion value) of polymer (A1) was added to a biaxial planetary mixer (manufactured by Primex Co., Ltd., trade name "TK Hibismix 2P-03"). , Add 10% by mass of the polymer (A1) obtained above as a composition for a storage device having a pH of 7.0), and 1.0 mass of a thickener (trade name "CMC2200", manufactured by Daicel Co., Ltd.). 77 parts by mass (solid content conversion value) of artificial graphite (manufactured by Showa Denko Materials Co., Ltd., trade name "MAG"), which is highly crystalline graphite as the negative electrode active material, of the graphite-coated silicon oxide obtained above. 19 parts by mass (solid content conversion value) of the powder and 1 part by mass of carbon (acetylene black manufactured by Denka Co., Ltd.) as a conductivity-imparting agent were added, and the mixture was stirred at 60 rpm for 1 hour to obtain a paste. 1.8 parts by mass (solid conversion value) of SBR (manufactured by JSR Corporation, trade name "TRD105A") and water were added to the obtained paste to adjust the solid content concentration to 48% by mass, and then stirring and defoaming. machine using the (Corporation Thinky Ltd., trade name "bubble tori Rentaro"), for 2 minutes at 200rpm, 5 minutes at 1,800rpm, in further under reduced pressure (about 2.5 × 10 4 Pa) 1,800rpm A slurry (C / Si = 80/20) for a power storage device electrode containing 20% by mass of Si in the negative electrode active material was prepared by stirring and mixing for 1.5 minutes.
　５．１．３．蓄電デバイスの製造及び評価
（１）蓄電デバイス電極（負極）の製造
　厚み２０μｍの銅箔よりなる集電体の表面に、上記で得られた蓄電デバイス電極用スラリー（Ｃ／Ｓｉ＝８０／２０）を、乾燥後の膜厚が６０μｍとなるようにドクターブレード法によって均一に塗布し、６０℃で１０分間乾燥し、次いで１２０℃で１０分間乾燥処理した。その後、活物質層の密度が１．６ｇ／ｃｍ３となるようにロールプレス機によりプレス加工することにより、蓄電デバイス電極（負極）を得た。 5.1.3. Manufacture and evaluation of power storage device (1) Manufacture of power storage device electrode (negative electrode) On the surface of a current collector made of copper foil with a thickness of 20 μm, the slurry for power storage device electrode (C / Si = 80/20) obtained above. Was uniformly applied by the doctor blade method so that the film thickness after drying was 60 μm, dried at 60 ° C. for 10 minutes, and then dried at 120 ° C. for 10 minutes. Then, a power storage device electrode (negative electrode) was obtained by pressing with a roll press so that the density of the active material layer was 1.6 g / cm 3.
（２）負極塗工層の密着強度の評価
　上記で得られた電極シートの表面に、ナイフを用いて活物質層から集電体に達する深さまでの切り込みを２ｍｍ間隔で縦横それぞれ１０本入れて碁盤目の切り込みを作った。この切り込みに幅１８ｍｍの粘着テープ（ニチバン（株）製、商品名「セロテープ」（登録商標）ＪＩＳ　Ｚ１５２２に規定）を貼り付けて直ちに引き剥がし、活物質の脱落の程度を目視判定で評価した。評価基準は以下の通りである。評価結果を下表２に示す。
（評価基準）
・５点：活物質層の脱落が０個である。
・４点：活物質層の脱落が１～５個である。
・３点：活物質層の脱落が６～２０個である。
・２点：活物質層の脱落が２１～４０個である。
・１点：活物質層の脱落が４１個以上である。 (2) Evaluation of Adhesion Strength of Negative Electrode Coating Layer Using a knife, make 10 cuts in each of the vertical and horizontal directions at 2 mm intervals from the active material layer to the depth reaching the current collector on the surface of the electrode sheet obtained above. I made a notch on the grid. An adhesive tape having a width of 18 mm (manufactured by Nichiban Co., Ltd., trade name "Cellotape" (registered trademark) specified in JIS Z1522) was attached to this notch and immediately peeled off, and the degree of shedding of the active material was visually evaluated. The evaluation criteria are as follows. The evaluation results are shown in Table 2 below.
(Evaluation criteria)
-5 points: No dropout of the active material layer.
・ 4 points: 1 to 5 pieces of active material layer are shed.
・ 3 points: 6 to 20 active material layers were dropped.
-2 points: 21 to 40 pieces of active material layer are shed.
-Point 1: The number of active material layers dropped is 41 or more.
（３）対極（正極）の製造
　二軸型プラネタリーミキサー（プライミクス株式会社製、商品名「ＴＫハイビスミックス　２Ｐ－０３」）に、電気化学デバイス電極用バインダー（株式会社クレハ製、商品名「ＫＦポリマー＃１１２０」、以下「ＰＶＤＦ」と略す。）４．０質量部（固形分換算値）、導電助剤（デンカ株式会社製、商品名「デンカブラック５０％プレス品」）３．０質量部、正極活物質として平均粒子径５μｍのＬｉＣｏＯ２（ハヤシ化成株式会社製）１００質量部（固形分換算値）及びＮ－メチルピロリドン（ＮＭＰ）３６質量部を投入し、６０ｒｐｍで２時間攪拌を行った。得られたペーストにＮＭＰを追加し、固形分濃度を６５質量％に調整した後、攪拌脱泡機（株式会社シンキー製、商品名「泡とり練太郎」）を使用して、２００ｒｐｍで２分間、１，８００ｒｐｍで５分間、さらに減圧下（約２．５×１０４Ｐａ）において１，８００ｒｐｍで１．５分間攪拌混合することにより、正極用スラリーを調製した。アルミニウム箔よりなる集電体の表面に、この正極用スラリーを、溶媒除去後の膜厚が１５０μｍとなるようにドクターブレード法によって均一に塗布し、１２０℃で２０分間加熱して溶媒を除去した。その後、活物質層の密度が３．０ｇ／ｃｍ３となるようにロールプレス機によりプレス加工することにより、対極（正極）を得た。 (3) Manufacture of counter electrode (positive electrode) A biaxial planetary mixer (manufactured by Primex Co., Ltd., trade name "TK Hibismix 2P-03") and a binder for electrochemical device electrodes (manufactured by Kureha Corporation, product name "KF") Polymer # 1120 ”, hereinafter abbreviated as“ PVDF ”) 4.0 parts by mass (solid content conversion value), conductive aid (manufactured by Denka Co., Ltd., trade name“ Denka Black 50% Pressed Product ”) 3.0 parts by mass , 100 parts by mass (solid content conversion value) of LiCoO 2 (manufactured by Hayashi Kasei Co., Ltd.) and 36 parts by mass of N-methylpyrrolidone (NMP) having an average particle diameter of 5 μm were added as the positive electrode active material, and the mixture was stirred at 60 rpm for 2 hours. rice field. After adding NMP to the obtained paste and adjusting the solid content concentration to 65% by mass, a stirring defoaming machine (manufactured by Shinky Co., Ltd., trade name "Awatori Rentaro") was used at 200 rpm for 2 minutes. , 1,800 rpm for 5 minutes, and further under reduced pressure (about 2.5 × 10 4 Pa) at 1,800 rpm for 1.5 minutes to prepare a slurry for a positive electrode. This positive electrode slurry was uniformly applied to the surface of the current collector made of aluminum foil by the doctor blade method so that the film thickness after removing the solvent was 150 μm, and heated at 120 ° C. for 20 minutes to remove the solvent. .. Then, a counter electrode (positive electrode) was obtained by press working with a roll press machine so that the density of the active material layer was 3.0 g / cm 3.
（４）リチウムイオン電池セルの組立て
　露点が－８０℃以下となるようＡｒ置換されたグローブボックス内で、上記で製造した負極を５０ｍｍ×２５ｍｍに打ち抜き成形したものにＮｉ製タブを溶接し、５６ｍｍ×３２ｍｍのポリプロピレン製のシート上に載置した。次いで、５５ｍｍ×３０ｍｍに打ち抜いたポリプロピレン製多孔膜からなるセパレータ（セルガード株式会社製、商品名「セルガード＃２４００」）を載置し、上記で製造した正極を４８ｍｍ×２３ｍｍに打ち抜き成形したのちＡｌ製タブを溶接したものを載置し、更に５６ｍｍ×３２ｍｍのポリプロピレン製のシートを載置した。前記構造体の長辺部分の上下に２ｍｍ×５ｍｍのカプトンテープを貼り付けることによって構造体を固定し、２枚の６ｃｍ×１１ｃｍのラミネートフィルムの間に中央になるよう挟み、１８０℃で３辺を１ｃｍ幅で熱シールした。その後、電解液を６５０μＬ注入した後、残り１辺を真空シールすることにより、リチウムイオン電池セル（蓄電デバイス）を組み立てた。ここで使用した電解液は、エチレンカーボネート／ジメチルカーボネート＝３／７（質量比）の溶媒に、ＬｉＰＦ６を１モル／Ｌの濃度で溶解し、フルオロエチルカーボネートを２質量％、ビニルカーボネートを１質量％溶解させた溶液である。 (4) Assembly of Lithium Ion Battery Cell In a glove box Ar-substituted so that the dew point is -80 ° C or less, a Ni tab is welded to a glove box made by punching and molding the negative electrode manufactured above to 50 mm × 25 mm, and 56 mm. It was placed on a sheet made of polypropylene of × 32 mm. Next, a separator made of a polypropylene porous film punched to 55 mm × 30 mm (manufactured by Cellguard Co., Ltd., trade name “Cellguard # 2400”) was placed, and the positive electrode manufactured above was punched to 48 mm × 23 mm and then manufactured by Al. A welded tab was placed, and a polypropylene sheet of 56 mm × 32 mm was further placed. The structure is fixed by sticking 2 mm × 5 mm Kapton tape on the top and bottom of the long side portion of the structure, sandwiched between two 6 cm × 11 cm laminated films so as to be in the center, and three sides at 180 ° C. Was heat-sealed with a width of 1 cm. Then, after injecting 650 μL of the electrolytic solution, the remaining one side was vacuum-sealed to assemble a lithium ion battery cell (storage device). The electrolytic solution used here was prepared by dissolving LiPF 6 at a concentration of 1 mol / L in a solvent of ethylene carbonate / dimethyl carbonate = 3/7 (mass ratio), 2% by mass of fluoroethyl carbonate, and 1 by mass of vinyl carbonate. It is a solution in which mass% is dissolved.
（５）充放電サイクル特性（１００サイクル容量維持率）の評価
　上記で製造した蓄電デバイスにつき、２５℃に調温された恒温槽にて、定電流（１．０Ｃ）にて充電を開始し、電圧が４．２Ｖになった時点で引き続き定電圧（４．２Ｖ）にて充電を続行し、電流値が０．０１Ｃとなった時点を充電完了（カットオフ）とした。その後、４５℃に調温された恒温槽にて定電流（１．０Ｃ）にて放電を開始し、電圧が３．０Ｖになった時点を放電完了（カットオフ）とし、１サイクル目の放電容量を算出した。このようにして１００回充放電を繰り返した。下記式により容量保持率を計算し、下記の基準で評価した。評価結果を下表２に示す。
　容量保持率（％）＝（１００サイクル目の放電容量）／（１サイクル目の放電容量）
（評価基準）
・５点：容量保持率が９０％以上。
・４点：容量保持率が８８％以上～９０％未満。
・３点：容量保持率が８６％以上～８８％未満。
・２点：容量保持率が８４％以上～８６％未満。
・１点：容量保持率が８２％以上～８４％未満。
・０点：容量保持率が８２％未満。 (5) Evaluation of charge / discharge cycle characteristics (100 cycle capacity retention rate) The power storage device manufactured above was charged at a constant current (1.0 C) in a constant temperature bath adjusted to 25 ° C. When the voltage reached 4.2 V, charging was continued at a constant voltage (4.2 V), and when the current value reached 0.01 C, charging was completed (cutoff). After that, discharge is started at a constant current (1.0 C) in a constant temperature bath adjusted to 45 ° C., and when the voltage reaches 3.0 V, discharge is completed (cutoff), and discharge in the first cycle is performed. The capacity was calculated. In this way, charging and discharging were repeated 100 times. The capacity retention rate was calculated by the following formula and evaluated according to the following criteria. The evaluation results are shown in Table 2 below.
Capacity retention rate (%) = (Discharge capacity in the 100th cycle) / (Discharge capacity in the 1st cycle)
(Evaluation criteria)
・ 5 points: Capacity retention rate is 90% or more.
-4 points: Capacity retention rate is 88% or more and less than 90%.
-3 points: Capacity retention rate is 86% or more and less than 88%.
-2 points: Capacity retention rate is 84% or more and less than 86%.
-1 point: Capacity retention rate is 82% or more and less than 84%.
-0 points: Capacity retention rate is less than 82%.
　なお、測定条件において「１Ｃ」とは、ある一定の電気容量を有するセルを定電流放電して１時間で放電終了となる電流値のことを示す。例えば「０．１Ｃ」とは、１０時間かけて放電終了となる電流値のことであり、「１０Ｃ」とは、０．１時間かけて放電完了となる電流値のことをいう。 In the measurement conditions, "1C" indicates a current value at which a cell having a certain electric capacity is discharged with a constant current and the discharge is completed in 1 hour. For example, "0.1C" is a current value at which the discharge is completed over 10 hours, and "10C" is a current value at which the discharge is completed over 0.1 hours.
（６）極板膨張率の評価
　上記で製造した負極の膜厚を計測し、初期膜厚とした。そして上記で製造した蓄電デバイスにつき、２５℃で調温された恒温槽にて、定電流（０．２Ｃ）にて充電を開始し、電圧が４．２Ｖになった時点で引き続き定電圧（４．２Ｖ）にて充電を続行し、電流値が０．０１Ｃとなった時点を充電完了（カットオフ）とした。その後、２５℃に調温された恒温槽にて定電流（０．２Ｃ）にて放電を開始し、電圧が２．５Ｖになった時点を放電完了（カットオフ）とし、化成充放電を完了させた。その後、蓄電デバイスに接触センサ（キーエンス社製、製品名「ＧＴ２－Ｈ１２ＫＬＦ」）を取り付け、その時点の膜厚を化成後の膜厚とした。そして定電流（０．２Ｃ）にて充電を開始し、電圧が４．２Ｖになった時点で引き続き定電圧（４．２Ｖ）にて充電を続行し、電流値が０．０１Ｃとなった時点を充電完了（カットオフ）とした。その後、２５℃に調温された恒温槽にて定電流（０．２Ｃ）にて放電を開始し、電圧が２．５Ｖになった時点を放電完了（カットオフ）とし、１０サイクル目放電時の膜厚を計測することで、下記式により極板膨張率を計算し、下記の基準で評価した。評価結果を下表２に示す。
　極板膨張率（％）＝（（１０サイクル目放電時の膜厚）－（化成後の膜厚）/（初期膜厚））×１００
（評価基準）
・５点：極板膨張率が２８％以下。
・４点：極板膨張率が２８％超～３０％以下。
・３点：極板膨張率が３０％超～３２％以下。
・２点：極板膨張率が３２％超～３４％以下。
・１点：極板膨張率が３４％超。 (6) Evaluation of electrode plate expansion coefficient The film thickness of the negative electrode manufactured above was measured and used as the initial film thickness. Then, the power storage device manufactured above is charged at a constant current (0.2C) in a constant temperature bath regulated at 25 ° C., and when the voltage reaches 4.2V, the constant voltage (4) is continued. Charging was continued at .2V), and charging was completed (cutoff) when the current value reached 0.01C. After that, discharging is started at a constant current (0.2C) in a constant temperature bath adjusted to 25 ° C., and when the voltage reaches 2.5V, the discharge is completed (cutoff), and the chemical charging / discharging is completed. I let you. After that, a contact sensor (manufactured by KEYENCE, product name "GT2-H12KLF") was attached to the power storage device, and the film thickness at that time was taken as the film thickness after chemical conversion. Then, charging is started at a constant current (0.2C), and when the voltage reaches 4.2V, charging is continued at a constant voltage (4.2V), and when the current value reaches 0.01C. Was considered to be fully charged (cutoff). After that, discharging is started at a constant current (0.2C) in a constant temperature bath adjusted to 25 ° C., and when the voltage reaches 2.5V, the discharging is completed (cutoff), and at the time of discharging in the 10th cycle. By measuring the film thickness of, the electrode plate expansion coefficient was calculated by the following formula and evaluated according to the following criteria. The evaluation results are shown in Table 2 below.
Plate expansion coefficient (%) = ((film thickness at 10th cycle discharge)-(film thickness after chemical conversion) / (initial film thickness)) × 100
(Evaluation criteria)
・ 5 points: The coefficient of expansion of the electrode plate is 28% or less.
・ 4 points: The coefficient of expansion of the electrode plate is more than 28% to 30% or less.
・ 3 points: The coefficient of expansion of the electrode plate is more than 30% to 32% or less.
-2 points: The coefficient of expansion of the electrode plate is more than 32% to 34% or less.
・ 1 point: The coefficient of expansion of the electrode plate exceeds 34%.
　５．２．実施例４、７～１０、比較例１、４～６
　上記「５．１．１．蓄電デバイス用組成物の調製及び評価　（１）蓄電デバイス用組成物の調製」において、各単量体の種類及び量を、それぞれ下表１に記載の通りとした以外は同様にして重合体を１０質量％含有する各蓄電デバイス用組成物を得た。また、このようにして得られた蓄電デバイス用組成物について、上記実施例１と同様にして粘度及び数平均分子量を測定した。なお、本明細書において、実施例＊で得られた重合体（Ａ）を「重合体（Ａ＊）」と呼称し、同様に、比較例＊で得られた重合体を「重合体（Ｂ＊）」と呼称するものとする。すなわち、＊は実施例又は比較例の番号に対応している。 5.2. Examples 4, 7-10, Comparative Examples 1, 4-6
In the above "5.1.1. Preparation and evaluation of composition for power storage device (1) Preparation of composition for power storage device", the types and amounts of each monomer are as shown in Table 1 below. A composition for each power storage device containing 10% by mass of the polymer was obtained in the same manner except for the above. Further, the viscosity and number average molecular weight of the composition for a power storage device thus obtained were measured in the same manner as in Example 1 above. In the present specification, the polymer (A) obtained in Example * is referred to as "polymer (A *)", and similarly, the polymer obtained in Comparative Example * is referred to as "polymer (B)". *) ”. That is, * corresponds to the number of the example or the comparative example.
　次いで、蓄電デバイス電極用スラリーの重合体組成を下表２に示すように変更した以外は上記実施例１と同様にして蓄電デバイス電極用スラリーをそれぞれ調製し、蓄電デバイス電極及び蓄電デバイスをそれぞれ作製し、上記実施例１と同様に評価した。 Next, the slurry for the power storage device electrode was prepared in the same manner as in Example 1 above except that the polymer composition of the slurry for the power storage device electrode was changed as shown in Table 2 below, and the power storage device electrode and the power storage device were respectively prepared. Then, it was evaluated in the same manner as in Example 1 above.
　５．３．実施例２
　５．３．１．アクリル系重合体の合成
　容量７リットルのセパラブルフラスコに、水１５０質量部及びドデシルベンゼンスルホン酸ナトリウム０．２質量部を仕込み、セパラブルフラスコの内部を十分に窒素置換した。一方、別の容器に、水６０質量部、乳化剤としてエーテルサルフェート型乳化剤（商品名「アデカリアソープＳＲ１０２５」、（株）ＡＤＥＫＡ製）を固形分換算で０．８質量部、単量体として、ブチルアクリレート（ＢＡ）２０質量部、メタクリル酸シクロヘキシル（ＣＨＭＡ）２２質量部、アクリロニトリル（ＡＮ）８質量部、メタクリル酸メチル（ＭＭＡ）５質量部、アクリル酸２－エチルヘキシル（ＥＨＡ）４０質量部及びアクリル酸（ＡＡ）５質量部を加え、十分に攪拌して上記単量体の混合物を含有する単量体乳化液を調製した。 5.3. Example 2
5.3.1. Synthesis of Acrylic Polymer 150 parts by mass of water and 0.2 parts by mass of sodium dodecylbenzenesulfonate were placed in a separable flask having a capacity of 7 liters, and the inside of the separable flask was sufficiently replaced with nitrogen. On the other hand, in another container, 60 parts by mass of water and an ether sulfate type emulsifier (trade name "Adecaria Soap SR1025", manufactured by ADEKA Co., Ltd.) as an emulsifier were added to 0.8 parts by mass in terms of solid content as a monomer. 20 parts by mass of butyl acrylate (BA), 22 parts by mass of cyclohexyl methacrylate (CHMA), 8 parts by mass of acrylonitrile (AN), 5 parts by mass of methyl methacrylate (MMA), 40 parts by mass of 2-ethylhexyl acrylate (EHA) and acrylic. 5 parts by mass of acid (AA) was added, and the mixture was sufficiently stirred to prepare a monomeric emulsion containing a mixture of the above monomers.
　上記セパラブルフラスコ内部の昇温を開始し、内部の温度が６０℃に到達した時点で、重合開始剤として過硫酸アンモニウム０．５質量部を加えた。そして、セパラブルフラスコの内部の温度が７０℃に到達した時点で、上記で調製した単量体乳化液の添加を開始し、セパラブルフラスコの内部の温度を７０℃に維持したまま単量体乳化液を３時間かけてゆっくりと添加した。その後、セパラブルフラスコの内部の温度を８５℃に昇温し、この温度を３時間維持して重合反応を行った。３時間後、セパラブルフラスコを冷却して反応を停止した後、アンモニウム水を加えてｐＨを７．６に調整することにより、アクリル系重合体からなる粒子を３０質量％含有する水系分散体を得た。 When the temperature inside the separable flask was started and the temperature inside reached 60 ° C., 0.5 part by mass of ammonium persulfate was added as a polymerization initiator. Then, when the temperature inside the separable flask reaches 70 ° C., the addition of the monomer emulsion prepared above is started, and the monomer is maintained while maintaining the temperature inside the separable flask at 70 ° C. The emulsion was added slowly over 3 hours. Then, the temperature inside the separable flask was raised to 85 ° C., and this temperature was maintained for 3 hours to carry out the polymerization reaction. After 3 hours, the separable flask was cooled to stop the reaction, and then ammonium water was added to adjust the pH to 7.6 to obtain an aqueous dispersion containing 30% by mass of particles made of an acrylic polymer. Obtained.
　５．３．２．蓄電デバイス用組成物の調製及び物性評価
　上記「５．１．１．蓄電デバイス用組成物の調製及び評価　（１）蓄電デバイス用組成物の調製」において、各単量体の種類及び量を、それぞれ下表１に記載の通りとした以外は同様にして重合体（Ａ２）を１０質量％含有するｐＨ１０．０の蓄電デバイス用組成物を得た。また、このようにして得られた蓄電デバイス用組成物について、上記実施例１と同様にして粘度及び数平均分子量を測定した。 5.3.2. Preparation and evaluation of physical properties of composition for power storage device In the above "5.1.1. Preparation and evaluation of composition for power storage device (1) Preparation of composition for power storage device", the type and amount of each monomer are determined. A composition for a power storage device having a pH of 10.0 containing 10% by mass of the polymer (A2) was obtained in the same manner except as shown in Table 1 below. Further, the viscosity and number average molecular weight of the composition for a power storage device thus obtained were measured in the same manner as in Example 1 above.
　５．３．３．蓄電デバイス電極用スラリーの調製
　次いで、二軸型プラネタリーミキサー（プライミクス株式会社製、商品名「ＴＫハイビスミックス　２Ｐ－０３」）に、先添加成分として、増粘剤（商品名「ＣＭＣ２２００」、株式会社ダイセル製）を１質量部（固形分換算値、濃度２質量％の水溶液として添加）、重合体（Ａ２）を０．２質量部（固形分換算値、上記で得られた重合体（Ａ２）を１０質量％含有するｐＨ１０．０の蓄電デバイス用組成物として添加）、負極活物質として結晶性の高いグラファイトである人造黒鉛（昭和電工マテリアルズ株式会社製、商品名「ＭＡＧ」）を７７質量部（固形分換算値）、上記で得られた黒鉛被膜酸化ケイ素の粉末を１９質量部（固形分換算値）、導電付与剤であるカーボン（デンカ株式会社製、アセチレンブラック）を１質量部投入し、６０ｒｐｍで１時間攪拌を行った。次いで、後添加成分として上記で合成したアクリル系重合体を１．８質量部（固形分換算）に相当する量だけ加え、さらに１時間攪拌しペーストを得た。得られたペーストに水を投入し、固形分濃度を４８質量％に調整した後、攪拌脱泡機（株式会社シンキー製、商品名「泡とり練太郎」）を使用して、２００ｒｐｍで２分間、１，８００ｒｐｍで５分間、さらに減圧下（約２．５×１０４Ｐａ）において１，８００ｒｐｍで１．５分間攪拌混合することにより、負極活物質中にＳｉを２０質量％含有する蓄電デバイス電極用スラリー（Ｃ／Ｓｉ＝８０／２０）を調製した。 5.3.3. Preparation of slurry for power storage device electrodes Next, a thickener (trade name "CMC2200", stock name "CMC2200", trade name, stock name " 1 part by mass (solid content conversion value, added as an aqueous solution with a concentration of 2% by mass) (manufactured by Daicel Co., Ltd.), 0.2 parts by mass (solid content conversion value, solid content conversion value, polymer (A2) obtained above) ) Is added as a composition for a power storage device containing 10% by mass of pH 10.0), and artificial graphite (manufactured by Showa Denko Materials Co., Ltd., trade name "MAG"), which is highly crystalline graphite as a negative electrode active material, is 77. Parts by mass (solid content conversion value), 19 parts by mass (solid content conversion value) of the graphite-coated silicon oxide powder obtained above, and 1 part by mass of carbon (made by Denka Co., Ltd., acetylene black) as a conductivity-imparting agent. It was charged and stirred at 60 rpm for 1 hour. Next, the acrylic polymer synthesized above was added as a post-addition component in an amount corresponding to 1.8 parts by mass (in terms of solid content), and the mixture was further stirred for 1 hour to obtain a paste. Water is added to the obtained paste to adjust the solid content concentration to 48% by mass, and then a stirring defoaming machine (manufactured by Shinky Co., Ltd., trade name "Awatori Rentaro") is used at 200 rpm for 2 minutes. , A storage device containing 20% by mass of Si in the negative electrode active material by stirring and mixing at 1,800 rpm for 5 minutes and further under reduced pressure (about 2.5 × 10 4 Pa) at 1,800 rpm for 1.5 minutes. An electrode slurry (C / Si = 80/20) was prepared.
　５．３．４．蓄電デバイスの製造及び評価
　上記で調製した蓄電デバイス電極用スラリーを用いた以外は、上記実施例１と同様にして、蓄電デバイス電極及び蓄電デバイスを作製し、上記実施例１と同様に評価した。 5.3.4. Manufacture and Evaluation of Power Storage Device Electrodes and power storage devices were produced in the same manner as in Example 1 except that the slurry for power storage device electrodes prepared above was used, and evaluated in the same manner as in Example 1.
　５．４．実施例５、比較例２
　上記「５．３．２．蓄電デバイス用組成物の調製及び粘度測定」において、各単量体の種類及び量を、それぞれ下表１に記載の通りとした以外は同様にして重合体を１０質量％含有する各蓄電デバイス用組成物を得た。また、このようにして得られた蓄電デバイス用組成物について、上記実施例１と同様にして粘度及び数平均分子量を測定した。 5.4. Example 5, Comparative Example 2
In the above "5.3.2.2 Preparation of composition for power storage device and measurement of viscosity", the polymer was prepared in the same manner except that the type and amount of each monomer were as shown in Table 1 below. A composition for each power storage device containing mass% was obtained. Further, the viscosity and number average molecular weight of the composition for a power storage device thus obtained were measured in the same manner as in Example 1 above.
　次いで、蓄電デバイス電極用スラリーの重合体組成を下表２に示すように変更した以外は上記実施例２と同様にして蓄電デバイス電極用スラリーをそれぞれ調製し、蓄電デバイス電極及び蓄電デバイスをそれぞれ作製し、上記実施例２と同様に評価した。 Next, the slurry for the power storage device electrode was prepared in the same manner as in Example 2 above except that the polymer composition of the slurry for the power storage device electrode was changed as shown in Table 2 below, and the power storage device electrode and the power storage device were respectively prepared. Then, it was evaluated in the same manner as in Example 2 above.
　５．５．実施例３
　５．５．１．フッ素含有アクリル系重合体の合成
　電磁式撹拌機を備えた内容積約６Ｌのオートクレーブの内部を十分に窒素置換した後、脱酸素した純水２．５Ｌ及び乳化剤としてパーフルオロデカン酸アンモニウム２５ｇを仕込み、３５０ｒｐｍで撹拌しながら６０℃まで昇温した。次いで、単量体であるフッ化ビニリデン（ＶＤＦ）７０％及び六フッ化プロピレン（ＨＦＰ）３０％からなる混合ガスを、内圧が２０ｋｇ／ｃｍ２に達するまで仕込んだ。重合開始剤としてジイソプロピルパーオキシジカーボネートを２０％含有するフロン１１３溶液２５ｇを窒素ガスを使用して圧入し、重合を開始した。重合中は内圧が２０ｋｇ／ｃｍ２に維持されるようＶＤＦ６０．２％及びＨＦＰ３９．８％からなる混合ガスを逐次圧入して、圧力を２０ｋｇ／ｃｍ２に維持した。また、重合が進行するに従って重合速度が低下するため、３時間経過後に、先と同じ重合開始剤溶液の同量を窒素ガスを使用して圧入し、さらに３時間反応を継続した。その後、反応液を冷却すると同時に撹拌を停止し、未反応の単量体を放出した後に反応を停止することにより、重合体Ｆの微粒子を４０％含有する水系分散体を得た。得られた重合体につき、１９Ｆ－ＮＭＲにより分析した結果、各単量体の質量組成比はＶＤＦ／ＨＦＰ＝２１／４であった。 5.5. Example 3
5.5.1. Synthesis of Fluorine-Containing Acrylic Polymer After sufficiently replacing the inside of an autoclave with an internal volume of about 6 L equipped with an electromagnetic stirrer with nitrogen, 2.5 L of deoxygenated pure water and 25 g of ammonium perfluorodecanoate as an emulsifier are charged. , The temperature was raised to 60 ° C. with stirring at 350 rpm. Next, a mixed gas composed of 70% vinylidene fluoride (VDF) and 30% propylene hexafluoride (HFP), which are monomers, was charged until the internal pressure reached 20 kg / cm 2. 25 g of a Freon 113 solution containing 20% of diisopropylperoxydicarbonate as a polymerization initiator was press-fitted using nitrogen gas to initiate polymerization. A mixed gas consisting of 60.2% VDF and 39.8% HFP was sequentially press-fitted so that the internal pressure was maintained at 20 kg / cm 2 during the polymerization, and the pressure was maintained at 20 kg / cm 2 . Further, since the polymerization rate decreases as the polymerization progresses, after 3 hours, the same amount of the same polymerization initiator solution as before was press-fitted using nitrogen gas, and the reaction was continued for another 3 hours. Then, the reaction solution was cooled and the stirring was stopped at the same time, and the reaction was stopped after releasing the unreacted monomer to obtain an aqueous dispersion containing 40% of the fine particles of the polymer F. As a result of analyzing the obtained polymer by 19 F-NMR, the mass composition ratio of each monomer was VDF / HFP = 21/4.
　次いで、容量７Ｌのセパラブルフラスコの内部を十分に窒素置換した後、上記で得られた重合体Ｆの微粒子を含有する水系分散体を重合体Ｆ換算で２５質量部、乳化剤「アデカリアソープＳＲ１０２５」（商品名、株式会社ＡＤＥＫＡ製）０．５質量部、メタクリル酸メチル（ＭＭＡ）３０質量部、アクリル酸２－エチルヘキシル（ＥＨＡ）４０質量部、メタクリル酸（ＭＡＡ）５質量部、及び水１３０質量部を順次仕込み、７０℃で３時間攪拌し、重合体Ｆに単量体を吸収させた。次いで、油溶性重合開始剤であるアゾビスイソブチロニトリル０．５質量部を含有するテトラヒドロフラン溶液２０ｍＬを添加し、７５℃に昇温して３時間反応を行い、さらに８５℃で２時間反応を行った。その後、冷却した後に反応を停止し、２．５Ｎ水酸化ナトリウム水溶液でｐＨ７．０に調節することにより、フッ素含有アクリル系重合体を４０％含有する重合体組成物を得た。 Next, after sufficiently replacing the inside of the separable flask having a capacity of 7 L with nitrogen, the aqueous dispersion containing the fine particles of the polymer F obtained above was added to the aqueous dispersion having 25 parts by mass in terms of polymer F in terms of polymer F, and the emulsifier "Adecaria Soap SR1025". (Product name, manufactured by ADEKA Co., Ltd.) 0.5 parts by mass, methyl methacrylate (MMA) 30 parts by mass, 2-ethylhexyl acrylate (EHA) 40 parts by mass, methacrylic acid (MAA) 5 parts by mass, and water 130. The parts by mass were sequentially charged and stirred at 70 ° C. for 3 hours to allow the polymer F to absorb the monomer. Next, 20 mL of a tetrahydrofuran solution containing 0.5 parts by mass of azobisisobutyronitrile as an oil-soluble polymerization initiator was added, the temperature was raised to 75 ° C., the reaction was carried out for 3 hours, and the reaction was further carried out at 85 ° C. for 2 hours. Was done. Then, after cooling, the reaction was stopped, and the pH was adjusted to 7.0 with a 2.5N aqueous sodium hydroxide solution to obtain a polymer composition containing 40% of a fluorine-containing acrylic polymer.
　５．５．２．蓄電デバイス用組成物の調製及び物性評価
　上記「５．１．１．蓄電デバイス用組成物の調製及び評価　（１）蓄電デバイス用組成物の調製」において、各単量体の種類及び量を、それぞれ下表１に記載の通りとした以外は同様にして重合体（Ａ３）を１０質量％含有するｐＨ５．０の蓄電デバイス用組成物を得た。また、このようにして得られた蓄電デバイス用組成物について、上記実施例１と同様にして粘度及び数平均分子量を測定した。 5.5.2. Preparation and evaluation of physical properties of composition for power storage device In the above "5.1.1. Preparation and evaluation of composition for power storage device (1) Preparation of composition for power storage device", the type and amount of each monomer are determined. A composition for a power storage device having a pH of 5.0 containing 10% by mass of the polymer (A3) was obtained in the same manner except as shown in Table 1 below. Further, the viscosity and number average molecular weight of the composition for a power storage device thus obtained were measured in the same manner as in Example 1 above.
　５．５．３．蓄電デバイス電極用スラリーの調製
　次いで、二軸型プラネタリーミキサー（プライミクス株式会社製、商品名「ＴＫハイビスミックス　２Ｐ－０３」）に、先添加成分として、増粘剤（商品名「ＣＭＣ２２００」、株式会社ダイセル製）を１質量部（固形分換算値、濃度２質量％の水溶液として添加）、重合体（Ａ３）を０．２質量部（固形分換算値、上記で得られた重合体（Ａ３）を１０質量％含有するｐＨ５．０の蓄電デバイス用組成物として添加）、負極活物質として結晶性の高いグラファイトである人造黒鉛（昭和電工マテリアルズ株式会社製、商品名「ＭＡＧ」）を７７質量部（固形分換算値）、上記で得られた黒鉛被膜酸化ケイ素の粉末を１９質量部（固形分換算値）、導電付与剤であるカーボン（デンカ株式会社製、アセチレンブラック）を１質量部投入し、６０ｒｐｍで１時間攪拌を行った。次いで、後添加成分として上記で合成したフッ素含有アクリル系重合体を１．８質量部（固形分換算）に相当する量だけ加え、さらに１時間攪拌しペーストを得た。得られたペーストに水を投入し、固形分濃度を４８質量％に調整した後、攪拌脱泡機（株式会社シンキー製、商品名「泡とり練太郎」）を使用して、２００ｒｐｍで２分間、１，８００ｒｐｍで５分間、さらに減圧下（約２．５×１０４Ｐａ）において１，８００ｒｐｍで１．５分間攪拌混合することにより、負極活物質中にＳｉを２０質量％含有する蓄電デバイス電極用スラリー（Ｃ／Ｓｉ＝８０／２０）を調製した。 5.5.3. Preparation of slurry for power storage device electrodes Next, a thickener (trade name "CMC2200", stock name "CMC2200", trade name, stock name " 1 part by mass (solid content conversion value, added as an aqueous solution with a concentration of 2% by mass) (manufactured by Daicel Co., Ltd.), 0.2 parts by mass (solid content conversion value, solid content conversion value, polymer (A3) obtained above) ) Is added as a composition for a power storage device having a pH of 5.0 containing 10% by mass), and artificial graphite (manufactured by Showa Denko Materials Co., Ltd., trade name "MAG"), which is highly crystalline graphite as a negative electrode active material, is 77. Parts by mass (solid content conversion value), 19 parts by mass (solid content conversion value) of the graphite-coated silicon oxide powder obtained above, and 1 part by mass of carbon (made by Denka Co., Ltd., acetylene black) as a conductivity-imparting agent. It was charged and stirred at 60 rpm for 1 hour. Next, the fluorine-containing acrylic polymer synthesized above was added as a post-addition component in an amount corresponding to 1.8 parts by mass (in terms of solid content), and the mixture was further stirred for 1 hour to obtain a paste. Water is added to the obtained paste to adjust the solid content concentration to 48% by mass, and then a stirring defoaming machine (manufactured by Shinky Co., Ltd., trade name "Awatori Rentaro") is used at 200 rpm for 2 minutes. , A storage device containing 20% by mass of Si in the negative electrode active material by stirring and mixing at 1,800 rpm for 5 minutes and further under reduced pressure (about 2.5 × 10 4 Pa) at 1,800 rpm for 1.5 minutes. An electrode slurry (C / Si = 80/20) was prepared.
　５．５．４．蓄電デバイスの製造及び評価
　上記で調製した蓄電デバイス電極用スラリーを用いた以外は、上記実施例１と同様にして、蓄電デバイス電極及び蓄電デバイスを作製し、上記実施例１と同様に評価した。 5.5.4. Manufacture and Evaluation of Power Storage Device Electrodes and power storage devices were produced in the same manner as in Example 1 except that the slurry for power storage device electrodes prepared above was used, and evaluated in the same manner as in Example 1.
　５．６．実施例６、比較例３
　上記「５．５．２．蓄電デバイス用組成物の調製及び物性評価」において、各単量体の種類及び量を、それぞれ下表１に記載の通りとした以外は同様にして重合体成分を１０質量％含有する各蓄電デバイス用組成物を得た。また、このようにして得られた蓄電デバイス用組成物について、上記実施例１と同様にして粘度を測定した。 5.6. Example 6, Comparative Example 3
In the above "5.5.2.2 Preparation and evaluation of physical properties of composition for power storage device", the polymer components were similarly prepared in the same manner except that the types and amounts of each monomer were as shown in Table 1 below. A composition for each power storage device containing 10% by mass was obtained. Further, the viscosity of the composition for a power storage device thus obtained was measured in the same manner as in Example 1 above.
　次いで、蓄電デバイス電極用スラリーの重合体組成を下表２に示すように変更した以外は上記実施例３と同様にして蓄電デバイス電極用スラリーをそれぞれ調製し、蓄電デバイス電極及び蓄電デバイスをそれぞれ作製し、上記実施例３と同様に評価した。 Next, the slurry for the power storage device electrode was prepared in the same manner as in Example 3 above except that the polymer composition of the slurry for the power storage device electrode was changed as shown in Table 2 below, and the power storage device electrode and the power storage device were respectively prepared. Then, it was evaluated in the same manner as in Example 3 above.
　５．７．評価結果
　下表１に、実施例１～１０及び比較例１～５で使用した重合体の組成及び物性値を示す。下表２に、実施例１～１０及び比較例１～６で使用した蓄電デバイス電極用スラリーの重合体組成及び各評価結果を示す。 5.7. Evaluation Results Table 1 below shows the composition and physical property values of the polymers used in Examples 1 to 10 and Comparative Examples 1 to 5. Table 2 below shows the polymer composition and each evaluation result of the slurry for power storage device electrodes used in Examples 1 to 10 and Comparative Examples 1 to 6.
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
　上表１～上表２における単量体の略称は、それぞれ以下の化合物を表す。
＜環状カーボネート基を有する化合物＞
・ＶＤＯ：下記式（９）で表される化合物、４－ビニル－１，３－ジオキソラン－２－オン
・Ｍ－１：下記式（１０）で表される化合物
Figure JPOXMLDOC01-appb-C000007
  
＜不飽和カルボン酸＞
・ＴＡ：イタコン酸
・ＡＡ：アクリル酸
・ＭＡＡ：メタクリル酸
＜（メタ）アクリルアミド＞
・ＡＡＭ：アクリルアミド
・ＭＡＭ：メタクリルアミド
・ＤＡＡＭ：Ｎ，Ｎ－ジメチルアクリルアミド
＜スルホ基を有する化合物＞
・ＮＡＳＳ：スチレンスルホン酸ナトリウム
＜水酸基を有する化合物＞
・ＨＥＡ：アクリル酸２－ヒドロキシエチル
・ＨＥＭＡ：メタクリル酸２－ヒドロキシエチル
・ＶＡ：ビニルアルコール
＜不飽和カルボン酸エステル＞
・ＭＭＡ：メタクリル酸メチル
・ＣＨＭＡ：メタクリル酸シクロヘキシル
・ＢＡ：アクリル酸ｎ－ブチル
・ＥＡ：アクリル酸エチル
・２ＥＨＡ：アクリル酸２－エチルヘキシル
＜共役ジエン化合物＞
・ＢＤ：１，３－ブタジエン
＜芳香族ビニル化合物＞
・ＳＴ：スチレン
＜α，β－不飽和ニトリル化合物＞
・ＡＮ：アクリロニトリル The abbreviations of the monomers in Tables 1 and 2 above represent the following compounds, respectively.
<Compound having a cyclic carbonate group>
-VDO: Compound represented by the following formula (9), 4-vinyl-1,3-dioxolane-2-one-M-1: Compound represented by the following formula (10)
Figure JPOXMLDOC01-appb-C000007
<Unsaturated carboxylic acid>
-TA: Itaconic acid-AA: Acrylic acid-MAA: Methacrylic acid <(meth) acrylamide>
-AAM: Acrylamide-MAM: Methacrylamide-DAAM: N, N-dimethylacrylamide <Compound having a sulfo group>
-NASS: Sodium styrene sulfonate <Compound with hydroxyl group>
-HEA: 2-hydroxyethyl acrylate-HEMA: 2-hydroxyethyl methacrylate-VA: Vinyl alcohol <unsaturated carboxylic acid ester>
-MMA: Methyl methacrylate-CHMA: Cyclohexyl methacrylate-BA: n-butyl acrylate-EA: Ethyl acrylate-2EHA: 2-ethylhexyl acrylate <conjugated diene compound>
-BD: 1,3-butadiene <aromatic vinyl compound>
・ ST: Styrene <α, β-unsaturated nitrile compound>
・ AN: Acrylonitrile
　上表１及び上表２から明らかなように、実施例１～１０に示した本発明に係る蓄電デバイス用組成物を用いて調製された蓄電デバイス電極用スラリーは、比較例１～６の場合と比較して、充放電に伴う体積変化が大きい活物質同士を好適に結着させることができ、しかも活物質層と集電体の密着性を良好に維持できることが判明した。その結果、充放電を繰り返して、活物質が体積の膨張と収縮を繰り返したとしても、活物質層の剥離を効果的に抑制し、良好な充放電特性を維持できる蓄電デバイス電極が得られた。また、これらの蓄電デバイス電極を備える蓄電デバイス（リチウムイオン二次電池）は、充放電レート特性も良好となることが判明した。この理由としては、表１に示す実施例１～１０に係る蓄電デバイス電極は、極板膨張率の評価結果より、比較例１～６の場合と比較して、充放電による活物質層の膜厚変化を低減できており、活物質層内部の導電ネットワークを維持できるためと推測される。更に、これらの蓄電デバイス電極を備える蓄電デバイス（リチウムイオン二次電池）は、充放電サイクルを実施した際の容量維持率も良好となることが判明した。活物質に環状カーボネート基を有する重合体を被覆させることにより、充電時に環状カーボネート基の分解により活物質表面に良好な被膜が形成され、電解液成分の分解を抑制し、電解液枯渇を防いだためであると推測される。 As is clear from the above Tables 1 and 2, the slurry for the electricity storage device electrode prepared by using the composition for the electricity storage device according to the present invention shown in Examples 1 to 10 is the case of Comparative Examples 1 to 6. It was found that the active materials having a large volume change due to charging and discharging can be suitably bonded to each other, and the adhesion between the active material layer and the current collector can be maintained well. As a result, even if the active material repeatedly expands and contracts in volume by repeating charging and discharging, a power storage device electrode capable of effectively suppressing peeling of the active material layer and maintaining good charging and discharging characteristics was obtained. .. Further, it was found that the power storage device (lithium ion secondary battery) provided with these power storage device electrodes also has good charge / discharge rate characteristics. The reason for this is that the energy storage device electrodes according to Examples 1 to 10 shown in Table 1 have a film of an active material layer due to charge and discharge, as compared with the cases of Comparative Examples 1 to 6, based on the evaluation results of the electrode plate expansion coefficient. It is presumed that the change in thickness can be reduced and the conductive network inside the active material layer can be maintained. Furthermore, it was found that the power storage device (lithium ion secondary battery) provided with these power storage device electrodes also has a good capacity retention rate when the charge / discharge cycle is carried out. By coating the active material with a polymer having a cyclic carbonate group, a good film was formed on the surface of the active material by the decomposition of the cyclic carbonate group during charging, the decomposition of the electrolyte component was suppressed, and the electrolyte depletion was prevented. It is presumed to be due to this.
　本発明は、上記の実施形態に限定されるものではなく、種々の変形が可能である。本発明は、実施形態で説明した構成と実質的に同一の構成（例えば、機能、方法および結果が同一の構成、あるいは目的および効果が同一の構成）を包含する。また本発明は、上記の実施形態で説明した構成の本質的でない部分を他の構成に置き換えた構成を包含する。さらに本発明は、上記の実施形態で説明した構成と同一の作用効果を奏する構成または同一の目的を達成することができる構成をも包含する。さらに本発明は、上記の実施形態で説明した構成に公知技術を付加した構成をも包含する。
  The present invention is not limited to the above embodiment, and various modifications are possible. The present invention includes substantially the same configurations as those described in the embodiments (eg, configurations with the same function, method and result, or configurations with the same purpose and effect). The present invention also includes a configuration in which a non-essential part of the configuration described in the above embodiment is replaced with another configuration. Further, the present invention also includes a configuration that exhibits the same effects as the configuration described in the above embodiment or a configuration that can achieve the same object. Further, the present invention also includes a configuration in which a known technique is added to the configuration described in the above embodiment.

Claims (11)

  1. 　重合体（Ａ）と、液状媒体（Ｂ）と、を含有し、
    　前記重合体（Ａ）中に含まれる繰り返し単位の合計を１００質量部としたときに、前記重合体（Ａ）が、
    　環状カーボネート基を有する化合物に由来する繰り返し単位（ａ１）を１～５０質量部と、
    　不飽和カルボン酸に由来する繰り返し単位（ａ２）、（メタ）アクリルアミドに由来する繰り返し単位（ａ３）、スルホ基を有する化合物に由来する繰り返し単位（ａ４）、及び水酸基を有する化合物に由来する繰り返し単位（ａ５）からなる群より選択される少なくとも１種の繰り返し単位を５０～９９質量部と、
    を含有する、蓄電デバイス用組成物。     Containing the polymer (A) and the liquid medium (B),
    When the total of the repeating units contained in the polymer (A) is 100 parts by mass, the polymer (A) is:
    The repeating unit (a1) derived from the compound having a cyclic carbonate group is 1 to 50 parts by mass.
    A repeating unit derived from an unsaturated carboxylic acid (a2), a repeating unit derived from (meth) acrylamide (a3), a repeating unit derived from a compound having a sulfo group (a4), and a repeating unit derived from a compound having a hydroxyl group. At least one repeating unit selected from the group consisting of (a5) is 50 to 99 parts by mass.
    A composition for a power storage device containing.
  2. 　ｐＨが５～１１である、請求項１に記載の蓄電デバイス用組成物。 The composition for a power storage device according to claim 1, wherein the pH is 5 to 11.
  3. 　前記重合体（Ａ）の１０質量％水溶液の、ｐＨ９における粘度が、２０～２００，０００ｍＰａ・ｓである、請求項１または請求項２に記載の蓄電デバイス用組成物。 The composition for a power storage device according to claim 1 or 2, wherein the 10% by mass aqueous solution of the polymer (A) has a viscosity at pH 9 of 200,000 to 200,000 mPa · s.
  4. 　前記液状媒体（Ｂ）が水である、請求項１ないし請求項３のいずれか一項に記載の蓄電デバイス用組成物。 The composition for a power storage device according to any one of claims 1 to 3, wherein the liquid medium (B) is water.
  5. 　請求項１ないし請求項４のいずれか一項に記載の蓄電デバイス用組成物と、
    　スチレン－ブタジエン共重合体、アクリル系重合体及びフッ素系重合体からなる群より選択される少なくとも１種の重合体（Ｃ）と、
    を含有する、蓄電デバイス電極用スラリー。     The composition for a power storage device according to any one of claims 1 to 4.
    At least one polymer (C) selected from the group consisting of a styrene-butadiene copolymer, an acrylic polymer, and a fluorine-based polymer, and
    Slurry for power storage device electrodes.
  6. 　前記重合体（Ｃ）１００質量部に対し、前記重合体（Ａ）を５～１００質量部含有する、請求項５に記載の蓄電デバイス電極用スラリー。 The slurry for a power storage device electrode according to claim 5, which contains 5 to 100 parts by mass of the polymer (A) with respect to 100 parts by mass of the polymer (C).
  7. 　さらに、活物質を含有する、請求項５または請求項６に記載の蓄電デバイス電極用スラリー。 The slurry for a power storage device electrode according to claim 5 or 6, further containing an active material.
  8. 　前記活物質としてケイ素材料を含有する、請求項７に記載の蓄電デバイス電極用スラリー。 The slurry for a power storage device electrode according to claim 7, which contains a silicon material as the active material.
  9. 　さらに、増粘剤を含有する、請求項５ないし請求項８のいずれか一項に記載の蓄電デバイス電極用スラリー。 The slurry for a power storage device electrode according to any one of claims 5 to 8, further containing a thickener.
  10. 　集電体と、前記集電体の表面上に請求項５ないし請求項９のいずれか一項に記載の蓄電デバイス電極用スラリーが塗布及び乾燥されて形成された活物質層と、を備える蓄電デバイス電極。 A current collector comprising an active material layer formed by applying and drying the slurry for a power storage device electrode according to any one of claims 5 to 9 on the surface of the current collector. Device electrode.
  11. 　請求項１０に記載の蓄電デバイス電極を備える蓄電デバイス。
          A power storage device including the power storage device electrode according to claim 10.
PCT/JP2021/010328 2020-03-19 2021-03-15 Composition for power storage device, slurry for power storage device electrode, power storage device electrode, and power storage device WO2021187407A1 (en)

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