WO2015146787A1 - Conductive adhesive composition for electrochemical element electrodes and collector for electrochemical element electrodes - Google Patents

Conductive adhesive composition for electrochemical element electrodes and collector for electrochemical element electrodes Download PDF

Info

Publication number
WO2015146787A1
WO2015146787A1 PCT/JP2015/058279 JP2015058279W WO2015146787A1 WO 2015146787 A1 WO2015146787 A1 WO 2015146787A1 JP 2015058279 W JP2015058279 W JP 2015058279W WO 2015146787 A1 WO2015146787 A1 WO 2015146787A1
Authority
WO
WIPO (PCT)
Prior art keywords
conductive adhesive
weight
adhesive composition
monomer
meth
Prior art date
Application number
PCT/JP2015/058279
Other languages
French (fr)
Japanese (ja)
Inventor
吉田　直樹
Original Assignee
日本ゼオン株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日本ゼオン株式会社 filed Critical 日本ゼオン株式会社
Priority to JP2016510285A priority Critical patent/JP6519581B2/en
Publication of WO2015146787A1 publication Critical patent/WO2015146787A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J9/00—Adhesives characterised by their physical nature or the effects produced, e.g. glue sticks
    • C09J9/02—Electrically-conducting adhesives
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/02—Non-macromolecular additives
    • C09J11/04—Non-macromolecular additives inorganic
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • C09J133/24—Homopolymers or copolymers of amides or imides
    • C09J133/26—Homopolymers or copolymers of acrylamide or methacrylamide
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/20—Conductive material dispersed in non-conductive organic material
    • H01B1/24—Conductive material dispersed in non-conductive organic material the conductive material comprising carbon-silicon compounds, carbon or silicon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/22—Electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/22—Electrodes
    • H01G11/26—Electrodes characterised by their structure, e.g. multi-layered, porosity or surface features
    • H01G11/28—Electrodes characterised by their structure, e.g. multi-layered, porosity or surface features arranged or disposed on a current collector; Layers or phases between electrodes and current collectors, e.g. adhesives
    • 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
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/665—Composites
    • H01M4/667—Composites in the form of layers, e.g. coatings
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L2203/00—Applications
    • C08L2203/20—Applications use in electrical or conductive gadgets
    • 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 conductive adhesive composition for an electrochemical element electrode for forming a conductive adhesive layer provided between an electrode active material layer and a current collector, and the conductive adhesive composition for an electrochemical element electrode.
  • the present invention relates to a current collector for an electrochemical element electrode having a conductive adhesive layer formed of a material.
  • Electrochemical elements typified by lithium ion secondary batteries have high energy density and output density, so they are expected to be used in small applications such as mobile phones and notebook personal computers, and in large applications such as in-vehicle applications. Yes. For this reason, these electrochemical devices are required to be further improved, such as low resistance, high capacity, high withstand voltage and mechanical properties, and longer cycle life, as their applications expand and develop. It has been.
  • Electrodes for electrochemical devices are usually formed by laminating an electrode active material layer formed by binding an electrode active material and conductive carbon used as necessary with a binder on a current collector. It is.
  • the electrochemical element can increase the operating voltage and the energy density by using an organic electrolytic solution, but on the other hand, since the viscosity of the electrolytic solution is high, the internal resistance tends to increase. there were. Therefore, it has been proposed to provide a conductive adhesive layer between the electrode active material layer and the current collector in order to reduce the internal resistance and improve the adhesion between the electrode active material layer and the current collector. ing.
  • Patent Document 1 a copolymer containing conductive carbon, an ethylenically unsaturated rubonic acid monomer unit, a (meth) acrylic acid ester monomer unit, and a fluorine-containing (meth) acrylic acid ester monomer unit.
  • a conductive adhesive layer is formed using a conductive adhesive composition for an electrochemical element electrode containing a water-soluble polymer as a polymer and a binder.
  • a high potential active material such as LCO (LiCoO 2 ) may be used as an electrode active material.
  • LCO LiCoO 2
  • the kind of binder is not prescribed
  • An object of the present invention is to provide a conductive adhesive composition for an electrochemical element electrode capable of forming a conductive adhesive layer having good stability even when a high-potential active material is used, and the conductive for the electrochemical element electrode. It is providing the electrical power collector for electrochemical element electrodes which has the conductive adhesive layer formed of the conductive adhesive composition.
  • the present inventors have found that the above object can be achieved by using a specific particulate copolymer, and have completed the present invention.
  • a conductive adhesive composition for electrochemical element electrodes characterized in that it is a coalescence
  • a monomer mixture in which the particulate binder comprises 5 to 70 parts by weight of a (meth) acrylamide monomer and 1 to 50 parts by weight of a (meth) acrylate monomer provided that the monomer
  • the conductive adhesive composition for electrochemical element electrodes according to (1) obtained by polymerizing a total of 100 parts by weight of the components
  • Adhesive composition (4) A monomer mixture wherein the particulate binder further comprises 10 to 50 parts by weight of a monomer component containing at least one of vinyl alcohol, styrene and (meth) acrylonitrile (provided that the monomer).
  • the conductive adhesive composition for electrochemical element electrodes according to any one of (1) to (3) obtained by polymerizing a total of 100 parts by weight of the components, (5) The conductive adhesive composition for electrochemical element electrodes according to any one of (1) to (4), wherein the volume average particle diameter of the particulate binder is 5 to 500 nm, (6)
  • the conductive carbon content is 8 to 38% by weight, the particulate binder content is 0.5 to 10% by weight, and the water content is 60 to 90% by weight.
  • the conductive adhesive composition for electrochemical element electrodes according to any one of (1) to (5), (7) The conductive adhesive composition for electrochemical element electrodes according to any one of (1) to (6), further comprising 0.05 to 1% by weight of a nonionic surfactant, (8)
  • an electrochemical device electrode current collector obtained by applying and drying the electroconductive adhesive composition for electrochemical device electrodes according to any one of (1) to (8).
  • the conductive adhesive composition for electrochemical element electrodes of the present invention a conductive adhesive layer having good stability can be formed even when a high potential active material is used. Moreover, according to this invention, the electrical power collector for electrochemical element electrodes which has the conductive adhesive layer formed with this electrically conductive adhesive composition for electrochemical element electrodes is provided.
  • the conductive adhesive composition for electrochemical element electrodes of the present invention comprises conductive carbon, a particulate binder, and water, and the particulate binder is a (meth) acrylamide monomer and (meth) acrylic. It is a polymer containing a structural unit derived from an acid salt monomer.
  • (meth) acryl means “acryl” or “methacryl”.
  • the form of conductive carbon used in the conductive adhesive composition for electrochemical device electrodes according to the present invention is not particularly limited, but carbon Particles are preferred.
  • a carbon particle is a particle which consists only of carbon, or consists only of carbon substantially. Specific examples include graphite (specifically natural graphite, artificial graphite, etc.), carbon black (specifically acetylene black, ketjen black, other furnace blacks, channel black, thermal lamp black, etc.), carbon fiber. Is mentioned. Among these, it is preferable to use graphite and acetylene black.
  • the conductive carbon used in the present invention in addition to the above-described conductive carbon components, further, it preferably contains carbon nanotubes and graphene, and more preferably contains graphene.
  • the content of the conductive carbon in the adhesive composition is preferably 8 to 38% by weight from the viewpoint of improving the conductivity of the conductive adhesive layer and improving the output characteristics of the obtained electrochemical element. More preferably, it is 10 to 35% by weight, and further preferably 12 to 30% by weight.
  • the content ratio of the carbon nanotubes and graphene in the adhesive composition is the viewpoint that the conductivity of the conductive adhesive layer is improved and the output of the obtained electrochemical device From the viewpoint of improving the characteristics, it is preferably 0.1 to 10% by weight, more preferably 0.5 to 9% by weight, and still more preferably 1 to 8% by weight.
  • the volume average particle diameter of the conductive carbon is preferably 0.01 to 20 ⁇ m, more preferably 0.05 to 15 ⁇ m, and particularly preferably 0.1 to 10 ⁇ m from the viewpoint of maintaining good conductivity.
  • the volume average particle diameter is a volume average particle diameter calculated by measuring with a laser diffraction particle size distribution analyzer (SALD-3100, manufactured by Shimadzu Corporation).
  • the electrical resistivity of the conductive carbon is preferably 0.0001 to 1 ⁇ ⁇ cm from the viewpoint of further reducing the electron transfer resistance of the conductive adhesive layer and further reducing the internal resistance of the lithium ion secondary battery. More preferably, it is 0.0005 to 0.5 ⁇ ⁇ cm, and particularly preferably 0.001 to 0.1 ⁇ ⁇ cm.
  • the electrical resistivity is a resistance value converged with respect to the pressure measured by continuously applying pressure to the carbon particles using a powder resistance measurement system (MCP-PD51 type: manufactured by Dia Instruments).
  • the particulate binder used in the adhesive composition according to the present invention is a polymer containing structural units derived from a (meth) acrylamide monomer and a (meth) acrylate monomer.
  • acrylamide monomers having an N-methylol group such as N-methylol (meth) acrylamide, N, N-dimethylol (meth) acrylamide, and (meth) of primary amines such as (meth) acrylamide It is preferable to use an acrylamide monomer.
  • the content of the structural unit derived from the (meth) acrylamide monomer in the particulate binder can provide a conductive adhesive layer with good adhesion between the current collector and the electrode active material layer,
  • the particulate binder is a (meth) acrylamide monomer, preferably 5 to It is obtained by polymerizing a monomer mixture containing 70 parts by weight, more preferably 10 to 60 parts by weight, still more preferably 20 to 50 parts by weight.
  • the polymerization conversion rate of the monomer is preferably 90% or more, more preferably 93% or more, and still more preferably 95% or more, and the constituent unit ratio of the monomer of the obtained polymer is the single unit charged. It corresponds to the mixing ratio of the body.
  • the (meth) acrylate monomer a conductive adhesive layer having good adhesion between the current collector and the electrode active material layer is obtained, and a high-temperature cycle of the obtained lithium ion secondary battery From the viewpoint of good characteristics, it is preferable to use lithium (meth) acrylate and sodium (meth) acrylate, and more preferably lithium (meth) acrylate.
  • the content of the structural unit derived from the (meth) acrylate monomer in the particulate binder is a conductive adhesive layer with good adhesion between the current collector and the electrode active material layer,
  • the particulate binder has a total of monomer components as 100 parts by weight, and a (meth) acrylate monomer, It is preferably obtained by polymerizing a monomer mixture containing 1 to 50 parts by weight, more preferably 5 to 45 parts by weight, still more preferably 10 to 40 parts by weight, and particularly preferably 20 to 40 parts by weight.
  • the polymerization conversion rate of the monomer is preferably 90% or more, more preferably 93% or more, and still more preferably 95% or more, and the constituent unit ratio of the monomer of the obtained polymer is the single unit charged. It corresponds to the mixing ratio of the body.
  • the particulate binder used in the present invention is a monomer copolymerizable with a (meth) acrylamide monomer and a (meth) acrylate monomer (hereinafter referred to as “third monomer”). It may contain a structural unit derived from.
  • the third monomer is not particularly limited as long as the effects of the present invention are not significantly impaired. From the viewpoint of improving the dispersibility of the conductive carbon and improving the output characteristics of the obtained lithium ion secondary battery.
  • Vinyl alcohol, styrene, and (meth) acrylonitrile can be preferably used.
  • (meth) acrylonitrile is used in the meaning including both acrylonitrile and methacrylonitrile. That is, (meth) acrylonitrile may be either acrylonitrile or methacrylonitrile, or may contain both at the same time.
  • These third monomers can be used alone or in combination of two or more.
  • the content of the structural unit derived from the third monomer in the particulate binder is such that the dispersibility of the conductive carbon is good and the output characteristics of the resulting lithium ion secondary battery are good.
  • the binder is a single monomer containing 100 parts by weight of the total of the monomer components, preferably containing 10 to 50 parts by weight, more preferably 15 to 45 parts by weight, and even more preferably 20 to 40 parts by weight of the third monomer. It is obtained by polymerizing a monomer mixture.
  • the polymerization conversion rate of the monomer is preferably 90% or more, more preferably 93% or more, and still more preferably 95% or more, and the constituent unit ratio of the monomer of the obtained polymer is the single unit charged. It corresponds to the mixing ratio of the body.
  • the content ratio of the particulate binder in the adhesive composition is preferably from the viewpoint that the adhesion between the current collector and the electrode active material layer is good, and the cycle characteristics of the resulting electrochemical device are good. It is 0.5 to 10% by weight, more preferably 1 to 9% by weight, still more preferably 2 to 8% by weight.
  • the volume average particle diameter of the particulate binder is preferably 5 to 500 nm, more preferably 50 to 400 nm, and still more preferably 100 to 100 from the viewpoint of improving the adhesion between conductive carbons in the adhesive composition. 300 nm.
  • the production method of the particulate binder is not particularly limited.
  • the method for emulsion polymerization is not particularly limited, and a conventionally known emulsion polymerization method may be employed.
  • Examples of the polymerization initiator used for emulsion polymerization include inorganic peroxides such as sodium persulfate, potassium persulfate, ammonium persulfate, potassium perphosphate, and hydrogen peroxide; t-butyl peroxide, cumene hydroperoxide, p-menthane hydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, benzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide Organic peroxides such as oxide and t-butylperoxyisobutyrate; azo compounds such as azobisisobutyronitrile, azobis-2,4-dimethylvaleronitrile, azobiscyclohexanecarbonitrile, methyl azobisisobutyrate, etc. Et That.
  • inorganic peroxides can be preferably used.
  • These polymerization initiators can be used alone or in combination of two or more.
  • the peroxide initiator can also be used as a redox polymerization initiator in combination with a reducing agent such as sodium bisulfite.
  • the amount of the polymerization initiator used is preferably 0.05 to 5 parts by weight, more preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the total amount of the monomer mixture used for the polymerization.
  • a chain transfer agent at the time of emulsion polymerization in order to adjust the amount of insoluble tetrahydrofuran in the resulting particulate binder.
  • the chain transfer agent include alkyl mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, t-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-stearyl mercaptan; dimethylxanthogen disulfide, diisopropylxanthogendi Xanthogen compounds such as sulfide; thiuram compounds such as terpinolene, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetramethylthiuram monosulfide; phenols such as 2,6-di-t-but
  • alkyl mercaptans are preferable, and t-dodecyl mercaptan can be more preferably used.
  • chain transfer agents can be used alone or in combination of two or more.
  • the amount of chain transfer agent used is preferably 0.05 to 2 parts by weight, more preferably 0.1 to 1 part by weight, per 100 parts by weight of the monomer mixture.
  • anionic surfactant it is preferable to use an anionic surfactant during emulsion polymerization.
  • anionic surfactant By using an anionic surfactant, the polymerization stability can be improved.
  • anionic surfactant conventionally known anionic surfactants can be used in emulsion polymerization.
  • anionic surfactant examples include sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecyl sulfate, ammonium dodecyl sulfate, sodium octyl sulfate, sodium decyl sulfate, sodium tetradecyl sulfate, sodium hexadecyl sulfate, sodium octadecyl sulfate and the like.
  • alkylbenzene sulfonates such as sodium dodecylbenzene sulfonate, sodium lauryl benzene sulfonate, sodium hexadecyl benzene sulfonate
  • fats such as sodium lauryl sulfonate, sodium dodecyl sulfonate, sodium tetradecyl sulfonate Group sulfonates; and the like.
  • the amount of the anionic surfactant used is preferably 0.5 to 10 parts by weight, more preferably 1 to 5 parts by weight with respect to 100 parts by weight of the monomer mixture.
  • the amount used is small, the particle diameter of the obtained particles is large, and when the amount is large, the particle diameter tends to be small.
  • a nonionic surfactant, a cationic surfactant, an amphoteric surfactant, etc. can also be used together.
  • a pH adjusting agent such as sodium hydroxide and ammonia
  • a dispersing agent such as sodium hydroxide and ammonia
  • a chelating agent such as sodium hydroxide and ammonia
  • an oxygen scavenger such as sodium hydroxide and ammonia
  • a seed latex for adjusting the particle size
  • seed latex refers to a dispersion of fine particles that becomes the nucleus of the reaction during emulsion polymerization.
  • the fine particles often have a particle size of 100 nm or less.
  • the fine particles are not particularly limited, and general-purpose polymers such as acrylic polymers are used.
  • a particulate binder having a relatively uniform particle diameter can be obtained.
  • the polymerization temperature for carrying out the polymerization reaction is not particularly limited, but is usually 0 to 100 ° C., preferably 40 to 80 ° C. Emulsion polymerization is performed in such a temperature range, and the polymerization reaction is stopped at a predetermined polymerization conversion rate by adding a polymerization terminator or cooling the polymerization system.
  • the polymerization conversion rate for stopping the polymerization reaction is preferably 93% by weight or more, more preferably 95% by weight or more.
  • the unreacted monomer is removed, the pH and solid content concentration are adjusted, and the particulate binder is obtained in a form (latex) dispersed in a dispersion medium. Thereafter, if necessary, the dispersion medium may be replaced, or the dispersion medium may be evaporated to obtain the particulate binder in powder form.
  • the conductive adhesive composition for electrochemical element electrodes according to the present invention contains conductive carbon, a particulate binder, and water.
  • the adhesive composition is preferably a slurry composition in which conductive carbon and a particulate binder are dispersed in water.
  • the content ratio of each component is not particularly limited, but from the viewpoint of dispersibility and coatability of each component, the content ratio described above is preferable. That is, the content of the conductive carbon in the adhesive composition is preferably 8 to 38% by weight, more preferably 10 to 35% by weight, and further preferably 12 to 30% by weight. The ratio is preferably 0.5 to 10% by weight, more preferably 1 to 9% by weight, and still more preferably 2 to 8% by weight.
  • the balance is water and various components added as necessary.
  • the water content is preferably 60 to 90% by weight, more preferably 62 to 88% by weight from the viewpoint that the viscosity of the adhesive composition is desired and a uniform conductive adhesive layer can be formed. More preferably, it is 65 to 85% by weight.
  • the content ratio of the dispersion medium is too large, the conductivity of the conductive adhesive layer formed by the adhesive composition is lowered, and the wettability of the adhesive composition to the current collector substrate made of aluminum or the like is reduced. Decreases. Moreover, when the content rate of a dispersion medium is too small, the viscosity of an adhesive composition will increase and it is not suitable for coating.
  • the adhesive composition can be directly produced by using water as the dispersion medium, the production process can be simplified. Moreover, the working environment can be improved by using water as a dispersion medium.
  • the conductive adhesive composition for electrochemical element electrodes of the present invention may contain a surfactant.
  • a surfactant a nonionic surfactant can be preferably used.
  • Nonionic surfactants include polyoxyalkylene alkyl aryl ether surfactants, polyoxyalkylene alkyl ether surfactants, polyoxyalkylene fatty acid ester surfactants, sorbitan fatty acid ester surfactants, silicone surfactants, acetylenes Examples include alcohol surfactants and fluorine-containing surfactants.
  • polyoxyalkylene alkyl aryl ether surfactant examples include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, and polyoxyethylene dodecyl phenyl ether.
  • polyoxyalkylene alkyl ether surfactant examples include polyoxyethylene oleyl ether and polyoxyethylene lauryl ether.
  • polyoxyalkylene fatty acid ester surfactant examples include polyoxyethylene oleate, polyoxyethylene laurate, and polyoxyethylene distearate.
  • sorbitan fatty acid ester surfactant examples include sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, and polyoxyethylene stearate.
  • silicone surfactants include dimethylpolysiloxane.
  • acetylene alcohol surfactants examples include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5- Examples thereof include dimethyl-1-hexyne-3ol.
  • fluorine-containing surfactants include fluorine alkyl esters. These surfactants can be used alone or in combination of two or more.
  • the content ratio of the surfactant in the adhesive composition is preferably from the viewpoint that foaming is suppressed and the uniform conductive adhesive layer is obtained without the adhesive composition being repelled by the current collector substrate. 0.05 to 1% by weight, more preferably 0.1 to 0.9% by weight, still more preferably 0.2 to 0.8% by weight.
  • the adhesive composition of the present invention preferably contains a preservative.
  • the preservative include isothiazoline compounds and halogenated aliphatic nitro alcohols.
  • isothiazoline compounds can be preferably used.
  • antiseptics other than those described above can be used as long as the effects of the present invention are not hindered, and the antiseptics can be used alone or in combination of two or more.
  • the adhesive composition of the present invention requires binders, thickeners, anti-aging agents, antifoaming agents, antibacterial agents, anti-blistering agents, pH adjusting agents and the like other than those described above. Can be added accordingly.
  • the current collector of the present invention can be obtained, for example, by applying and drying the above adhesive composition on a current collector substrate. That is, it can be obtained by forming a conductive adhesive layer on the current collector substrate.
  • the material of the current collector base material is, for example, metal, carbon, conductive polymer, etc., and metal is preferably used.
  • metal aluminum, platinum, nickel, tantalum, titanium, stainless steel, copper, other alloys and the like are usually used. Among these, it is preferable to use copper, aluminum, or an aluminum alloy in terms of conductivity and voltage resistance.
  • the thickness of the current collector substrate is 1 to 100 ⁇ m, preferably 2 to 70 ⁇ m, particularly preferably 5 to 50 ⁇ m.
  • the method for forming the conductive adhesive layer is not particularly limited.
  • the conductive adhesive layer is formed on the current collector substrate by a doctor blade method, a dip method, a reverse roll method, a direct roll method, a gravure method, an extrusion method, a brush coating, or the like.
  • it may be transferred to the current collector substrate.
  • Examples of the method for drying the conductive adhesive layer include drying by hot air, hot air, low-humidity air, vacuum drying, and drying by irradiation with (far) infrared rays or electron beams. Of these, a drying method using hot air and a drying method using irradiation with far infrared rays are preferable.
  • the drying temperature and the drying time are preferably a temperature and a time at which the dispersion medium (water) in the adhesive composition coated on the current collector substrate can be completely removed, and the drying temperature is preferably 50 to 300 ° C.
  • the temperature is preferably 80 to 250 ° C.
  • the drying time is preferably 2 hours or less, more preferably 5 seconds to 30 minutes.
  • the thickness of the conductive adhesive layer is preferably 0 from the viewpoint of good adhesion between the electrode active material layer and the current collector through the conductive adhesive layer, and the output characteristics of the resulting electrochemical element are good. 0.5 to 5 ⁇ m, more preferably 0.6 to 4 ⁇ m, and even more preferably 0.7 to 3 ⁇ m.
  • the conductive adhesive layer has a composition corresponding to the solid composition of the adhesive composition, and includes conductive carbon, a particulate binder, and components used as necessary.
  • the electrode for an electrochemical element of the present invention has an electrode active material layer on the conductive adhesive layer of the current collector.
  • the electrode active material layer is composed of an electrode active material, an electrode binder, and an electrode conductive material used as necessary, and is formed using an electrode active material layer slurry containing these components.
  • the electrode active material may be a negative electrode active material or a positive electrode active material.
  • the electrode active material is a material that transfers electrons in the battery.
  • the positive electrode active material an active material capable of occluding and releasing lithium ions is used, and the positive electrode active material for lithium ion secondary batteries is roughly classified into those made of inorganic compounds and those made of organic compounds. .
  • Examples of the positive electrode active material made of an inorganic compound include transition metal oxides, transition metal sulfides, lithium-containing composite metal oxides of lithium and transition metals, and the like.
  • Examples of the transition metal include Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Mo.
  • transition metal oxide examples include MnO, MnO 2 , V 2 O 5 , V 6 O 13 , TiO 2 , Cu 2 V 2 O 3 , amorphous V 2 O—P 2 O 5 , MoO 3 and the like.
  • the lithium-containing composite metal oxide include a lithium-containing composite metal oxide having a layered structure, a lithium-containing composite metal oxide having a spinel structure, and a lithium-containing composite metal oxide having an olivine structure.
  • lithium-containing composite metal oxide having a layered structure examples include lithium-containing cobalt oxide (LiCoO 2 , (hereinafter sometimes referred to as “LCO”)), lithium-containing nickel oxide (LiNiO 2 ), and Co—Ni—.
  • LCO lithium-containing cobalt oxide
  • LiNiO 2 lithium-containing nickel oxide
  • Co—Ni— Co—Ni—.
  • (1-x) Li 2 MbO 3 (0 ⁇ x ⁇ 1, Ma is one or more transition metals whose average oxidation state is 3+
  • Mb is one or more transition metals whose average oxidation state is 4+).
  • Li a was replaced with Mn in Fe Fe x Mn 2-x O 4-z (0 ⁇ a ⁇ 1,0 ⁇ x ⁇ 1,0 ⁇ z ⁇ 0.1 ) is preferably since the cost is inexpensive, such as LiNi 0.5 Mn 1.5 O 4 obtained by replacing Mn with Ni can be replaced all the Mn 3+, which is thought to factor structural deterioration, the Ni 2+
  • the electrochemical reaction to Ni 4+ is preferable because it can have a high operating voltage and a high capacity.
  • An olivine type lithium phosphate compound represented by ⁇ 2 may be mentioned.
  • Mn, Co or Fe may be partially substituted with other metals, and examples of metals that can be substituted include Cu, Mg, Zn, V, Ca, Sr, Ba, Ti, Al, Si, B, and Mo. Can be mentioned.
  • a positive electrode active material having a polyanion structure such as Li 2 MeSiO 4 (where Me is Fe, Mn), LiFeF 3 having a perovskite structure, Li 2 Cu 2 O 4 having an orthorhombic structure, and the like.
  • a conductive polymer such as polyacetylene or poly-p-phenylene can be used.
  • An iron-based oxide having poor electrical conductivity may be used as an electrode active material covered with a carbon material by allowing a carbon source material to be present during reduction firing. These compounds may be partially element-substituted.
  • the positive electrode active material may be a mixture of the above inorganic compound and organic compound.
  • the active material for high potential represents an active material that can be charged to a higher potential.
  • lithium that can be charged to a potential of usually 4.0 V or higher, preferably 4.2 V or higher, more preferably 4.3 V or higher is desirable.
  • potential with respect to lithium is a value with respect to the potential that lithium metal exhibits in the non-aqueous electrolyte
  • potential that can be charged refers to the operating potential of the positive electrode using each positive electrode active material. Represents the value on the high potential side.
  • preferable positive electrode active materials include olivine type lithium phosphate compounds, lithium-containing cobalt oxides, lithium-containing nickel oxides, and lithium-manganese composite oxides. Further, a lithium-manganese-nickel composite oxide or the like may be used as a positive electrode active material that can be charged to a higher potential. These positive electrode active materials have a large energy density in addition to a high working potential, a large battery capacity. Among these, lithium-containing cobalt oxide, lithium-containing nickel oxide and lithium-manganese-nickel composite oxide are preferable, and lithium-containing cobalt oxide (LCO) is particularly preferable in that it can be charged to a higher potential.
  • LCO lithium-containing cobalt oxide
  • the volume average particle diameter of the electrode active material is preferably 0.01 to 100 ⁇ m, more preferably 0.05 to 50 ⁇ m, and still more preferably 0.1 to 20 ⁇ m for both the positive electrode active material and the negative electrode active material.
  • These electrode active materials can be used alone or in combination of two or more.
  • the conductive material for an electrode is made of an allotrope of particulate carbon that has conductivity and does not have pores that can form an electric double layer.
  • carbon black, furnace black, acetylene black, and Examples thereof include conductive carbon such as Ketjen Black (registered trademark of Akzo Nobel Chemicals Beslo Tenfen Note Shap).
  • Ketjen Black registered trademark of Akzo Nobel Chemicals Beslo Tenfen Note Shap.
  • acetylene black and furnace black are preferable.
  • the electrode binder is not particularly limited as long as it is a compound that can bind the electrode active material and the electrode conductive material to each other.
  • a suitable binder for electrodes is a dispersion-type binder having a property of being dispersed in a solvent.
  • the dispersion-type binder include polymer compounds such as a fluoropolymer, a diene polymer, an acrylate polymer, a polyimide, a polyamide, and a polyurethane polymer, and a fluoropolymer, a diene polymer, or an acrylate polymer is preferable.
  • a polymer or an acrylate polymer is more preferable in that the withstand voltage can be increased and the energy density of the lithium ion secondary battery can be increased.
  • the diene polymer is a homopolymer of a conjugated diene or a copolymer obtained by polymerizing a monomer mixture containing a conjugated diene, or a hydrogenated product thereof.
  • the ratio of the conjugated diene in the monomer mixture is preferably 40% by weight or more, more preferably 50% by weight or more, and further preferably 60% by weight or more.
  • the diene polymer include conjugated diene homopolymers such as polybutadiene and polyisoprene; aromatic vinyl / conjugated diene copolymers such as carboxy-modified styrene / butadiene copolymer (SBR); acrylonitrile -Vinyl cyanide * conjugated diene copolymers, such as a butadiene copolymer (NBR); Hydrogenated SBR, hydrogenated NBR, etc. are mentioned.
  • conjugated diene homopolymers such as polybutadiene and polyisoprene
  • aromatic vinyl / conjugated diene copolymers such as carboxy-modified styrene / butadiene copolymer (SBR); acrylonitrile -Vinyl cyanide *
  • the compound represented by the general formula examples include ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-amyl acrylate, isoamyl acrylate, hexyl acrylate, 2- Acrylates such as ethylhexyl acrylate, hexyl acrylate, nonyl acrylate, lauryl acrylate, stearyl acrylate; ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-amyl methacrylate, isoamyl methacrylate, Hexyl methacrylate, 2-ethylhexyl methacrylate, o
  • acrylate is preferable, and butyl acrylate and 2-ethylhexyl acrylate are particularly preferable in that the strength of the obtained electrode can be improved.
  • the proportion of the monomer unit derived from the acrylate ester and / or methacrylic acid ester in the acrylate polymer is preferably 50% by weight from the viewpoint of high heat resistance and low internal resistance of the obtained electrode for an electrochemical device. % Or more, more preferably 70% by weight or more.
  • a copolymerizable carboxylic acid group-containing monomer can be used in addition to the compound represented by the general formula (1).
  • Specific examples thereof include acrylic acid and methacrylic acid.
  • Examples include basic acid-containing monomers, and dibasic acid-containing monomers such as maleic acid, fumaric acid, and itaconic acid.
  • a dibasic acid-containing monomer is preferable, and itaconic acid is particularly preferable in terms of improving the binding property with the conductive adhesive layer and improving the electrode strength.
  • These monobasic acid-containing monomers and dibasic acid-containing monomers can be used alone or in combination of two or more.
  • the amount of the carboxylic acid group-containing monomer in the monomer mixture at the time of copolymerization is excellent in binding properties with the conductive adhesive layer, and from the viewpoint of increasing the obtained electrode strength, the general formula (1)
  • the amount is preferably 0.1 to 50 parts by weight, more preferably 0.5 to 20 parts by weight, and still more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the compound represented by formula (1).
  • a copolymerizable nitrile group-containing monomer can be used for the acrylate polymer.
  • the nitrile group-containing monomer include acrylonitrile, methacrylonitrile, and the like. Among them, acrylonitrile is preferable in that the binding strength with the conductive adhesive layer is increased and the electrode strength can be improved.
  • the amount of acrylonitrile in the monomer mixture is excellent in the binding property with the conductive adhesive layer, and the compound 100 represented by the general formula (1) from the viewpoint of increasing the electrode strength obtained.
  • the amount is preferably 0.1 to 40 parts by weight, more preferably 0.5 to 30 parts by weight, and still more preferably 1 to 20 parts by weight with respect to parts by weight.
  • the shape of the binder for the electrode is not particularly limited, but it has good binding properties with the conductive adhesive layer, and can suppress deterioration of the capacity of the prepared electrode and deterioration due to repeated charge and discharge. It is preferable that it is a shape.
  • the glass transition temperature (Tg) of the binder for the electrode is excellent in binding property with a small amount of use, strong in the electrode strength, rich in flexibility, and the viewpoint that the electrode density can be easily increased by the press process at the time of electrode formation. Therefore, it is preferably 50 ° C. or lower, more preferably ⁇ 40 to 0 ° C.
  • the number average particle diameter is not particularly limited. However, from the viewpoint that an excellent binding force can be imparted to the electrode even with a small amount of use, it is preferably 0.0001 to 100 ⁇ m, More preferably, it is 0.001 to 10 ⁇ m, and still more preferably 0.01 to 1 ⁇ m.
  • the number average particle diameter is a number average particle diameter calculated as an arithmetic average value obtained by measuring the diameter of 100 electrode binder particles randomly selected from a transmission electron micrograph. The shape of the particles can be either spherical or irregular.
  • the amount of the electrode binder used is from the viewpoint that the adhesion between the obtained electrode active material layer and the conductive adhesive layer can be sufficiently secured, the capacity of the lithium ion secondary battery can be increased, and the internal resistance can be decreased.
  • the amount is preferably 0.1 to 50 parts by weight, more preferably 0.5 to 20 parts by weight, and still more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the electrode active material.
  • the electrode active material layer is provided on the conductive adhesive layer, but the formation method is not limited.
  • the electrode active material layer slurry may contain an electrode active material and an electrode binder as essential components, and if necessary, an electrode conductive material and other dispersants and additives.
  • specific examples of other dispersants include cellulosic polymers such as carboxymethylcellulose, methylcellulose, ethylcellulose and hydroxypropylcellulose, and ammonium or alkali metal salts thereof; poly (meth) acrylic such as sodium poly (meth) acrylate. Acid salts; polyvinyl alcohol, modified polyvinyl alcohol, polyethylene oxide, polyvinyl pyrrolidone, polycarboxylic acid, oxidized starch, phosphate starch, casein, various modified starches and the like.
  • These dispersants can be used alone or in combination of two or more.
  • a cellulose polymer is preferable, and carboxymethyl cellulose or an ammonium salt or an alkali metal salt thereof is particularly preferable.
  • the amount of these dispersants is not particularly limited, but is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, and still more preferably 0 to 100 parts by weight of the electrode active material. 8 to 2 parts by weight.
  • the paste slurry for the electrode active material layer contains the essential components of the electrode active material and the electrode binder, and the electrode conductive material, dispersant and additive used as necessary. It can be produced by kneading in water or an organic solvent such as N-methyl-2-pyrrolidone or tetrahydrofuran.
  • the solvent used for obtaining the electrode active material layer slurry is not particularly limited, but when the above-described dispersant is used, a solvent capable of dissolving the dispersant is preferably used. Specifically, water is usually used, but an organic solvent may be used, or a mixed solvent of water and an organic solvent may be used.
  • organic solvent examples include alkyl alcohols such as methyl alcohol, ethyl alcohol and propyl alcohol; alkyl ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran, dioxane and diglyme; diethylformamide, dimethylacetamide and N-methyl- Amides such as 2-pyrrolidone and dimethylimidazolidinone; sulfur solvents such as dimethyl sulfoxide and sulfolane; and the like.
  • alkyl alcohols such as methyl alcohol, ethyl alcohol and propyl alcohol
  • alkyl ketones such as acetone and methyl ethyl ketone
  • ethers such as tetrahydrofuran, dioxane and diglyme
  • diethylformamide dimethylacetamide and N-methyl- Amides
  • sulfur solvents such as dimethyl sulfoxide and sulfolane; and the like.
  • the slurry for the electrode active material layer is preferably an aqueous slurry using water as a dispersion medium from the viewpoint of easy drying of the electrode active material layer and excellent environmental load.
  • water and an organic solvent having a lower boiling point than water are used in combination, the drying rate can be increased.
  • the dispersibility of the binder or the solubility of the dispersant varies depending on the amount or type of the organic solvent used in combination with water. Thereby, the viscosity and fluidity
  • the amount of the solvent used when preparing the slurry is such that the solid content concentration of the slurry is preferably 1 to 90% by weight, more preferably 5 to 85% by weight, and still more preferably, from the viewpoint of uniformly dispersing each component.
  • the amount is 10 to 80% by weight.
  • a method or procedure for dispersing or dissolving the electrode active material and the electrode binder, the electrode conductive material used as necessary, and other dispersants and additives in the solvent is not particularly limited.
  • the electrode active material in the solvent Method of adding and mixing electrode conductive material, electrode binder and other dispersant or additive; dissolving the dispersant in the solvent, then adding and mixing the electrode binder dispersed in the solvent, and finally the electrode
  • a method of adding and mixing an active material and a conductive material for an electrode adding and mixing an electrode active material and a conductive material for an electrode to a binder dispersed in a solvent, and dissolving the dispersant dissolved in the solvent into the mixture
  • the method of adding and mixing is mentioned.
  • Examples of the mixing means include mixing equipment such as a ball mill, a sand mill, a bead mill, a pigment disperser, a crusher, an ultrasonic disperser, a homogenizer, a homomixer, and a planetary mixer.
  • the mixing is preferably performed at room temperature to 80 ° C. for 10 minutes to several hours.
  • the viscosity of the electrode active material layer slurry is preferably 10 to 100,000 mPa ⁇ s, more preferably 30 to 50,000 mPa ⁇ s, and still more preferably 50 to 20,000 mPa ⁇ s from the viewpoint of increasing productivity at room temperature. s.
  • the method for applying the electrode active material layer slurry onto the conductive adhesive layer is not particularly limited. Examples thereof include a doctor blade method, a dip method, a reverse roll method, a direct roll method, a gravure method, an extrusion method, and a brush coating method.
  • the coating thickness of the electrode active material layer slurry is appropriately set according to the target thickness of the electrode active material layer.
  • drying method examples include drying with warm air, hot air, low-humidity air, vacuum drying, and drying by irradiation with (far) infrared rays or electron beams. Among these, a drying method by irradiation with far infrared rays is preferable.
  • the drying temperature and the drying time are preferably a temperature and a time at which the solvent in the slurry for the electrode active material layer applied to the conductive adhesive layer of the current collector can be completely removed.
  • the drying temperature is preferably 100 to 300 ° C., More preferably, the temperature is 120 to 250 ° C.
  • the drying time is preferably 10 minutes to 100 hours, more preferably 20 minutes to 20 hours.
  • the density of the electrode active material layer is not particularly limited, but is preferably 0.30 to 10 g / cm 3 , more preferably 0.35 to 8.0 g / cm 3 , and still more preferably 0.40 to 6.0 g / cm 3 . 3 .
  • the thickness of the electrode active material layer is not particularly limited, but is preferably 5 to 1000 ⁇ m, more preferably 20 to 500 ⁇ m, and still more preferably 30 to 300 ⁇ m.
  • Electrochemical element Examples of usage of the electrode for an electrochemical element include a lithium ion secondary battery, an electric double layer capacitor, a lithium ion capacitor, a sodium battery, and a magnesium battery using the electrode, and a lithium ion secondary battery is preferable. is there.
  • a lithium ion secondary battery is composed of the electrochemical element electrode, a separator, and an electrolytic solution.
  • a separator will not be specifically limited if it can insulate between the electrodes for electrochemical elements, and can allow a cation and an anion to pass through.
  • a porous separator having pores (a) a porous separator having pores, (b) a porous separator having a polymer coating layer formed on one or both sides, or (c) a porous resin coating layer containing inorganic ceramic powder A porous separator in which is formed.
  • Non-limiting examples of these include solids such as polypropylene, polyethylene, polyolefin, or aramid porous separators, polyvinylidene fluoride, polyethylene oxide, polyacrylonitrile, or polyvinylidene fluoride hexafluoropropylene copolymers.
  • a separator is arrange
  • the thickness of the separator is appropriately selected depending on the purpose of use, but is preferably 1 to 100 ⁇ m, more preferably 10 to 80 ⁇ m, and still more preferably 20 to 60 ⁇ m.
  • the electrolytic solution is not particularly limited.
  • a solution obtained by dissolving a lithium salt as a supporting electrolyte in a non-aqueous solvent can be used.
  • the lithium salt include LiPF 6 , LiAsF 6 , LiBF 4 , LiSbF 6 , LiAlCl 4 , LiClO 4 , CF 3 SO 3 Li, C 4 F 9 SO 3 Li, CF 3 COOLi, (CF 3 CO) 2 NLi , (CF 3 SO 2 ) 2 NLi, (C 2 F 5 SO 2 ) NLi, and other lithium salts.
  • LiPF 6 , LiClO 4 , and CF 3 SO 3 Li that are easily soluble in a solvent and exhibit a high degree of dissociation are preferably used. These can be used alone or in admixture of two or more.
  • the amount of the supporting electrolyte is preferably 1% by weight or more, more preferably 5% by weight or more, and preferably 30% by weight or less, more preferably 20% by weight or less with respect to the electrolytic solution. If the amount of the supporting electrolyte is too small or too large, the ionic conductivity is lowered, and the charging characteristics and discharging characteristics of the battery are degraded.
  • the solvent used in the electrolytic solution is not particularly limited as long as it can dissolve the supporting electrolyte.
  • Alkyl carbonates such as carbonate (BC) and methyl ethyl carbonate (MEC); esters such as ⁇ -butyrolactone and methyl formate; ethers such as 1,2-dimethoxyethane; tetrahydrofuran; sulfolane and dimethyl sulfoxide Sulfur-containing compounds are used.
  • dimethyl carbonate, ethylene carbonate, propylene carbonate, diethyl carbonate, and methyl ethyl carbonate are preferable because high ion conductivity is easily obtained and the use temperature range is wide. These can be used alone or in admixture of two or more. Moreover, it is also possible to use an electrolyte containing an additive.
  • the additive is preferably a carbonate compound such as vinylene carbonate (VC).
  • Examples of the electrolytic solution other than the above include a gel polymer electrolyte obtained by impregnating a polymer electrolyte such as polyethylene oxide and polyacrylonitrile with an electrolytic solution, and an inorganic solid electrolyte such as lithium sulfide, LiI, and Li 3 N.
  • a lithium ion secondary battery is obtained by stacking a negative electrode and a positive electrode through a separator, winding this according to the shape of the battery, folding it into a battery container, pouring the electrolyte into the battery container and sealing it. It is done. Further, if necessary, an expanded metal, an overcurrent prevention element such as a fuse or a PTC element, a lead plate and the like can be inserted to prevent an increase in pressure inside the battery and overcharge / discharge.
  • the shape of the battery may be any of a laminated cell type, a coin type, a button type, a sheet type, a cylindrical type, a square type, a flat type, and the like.
  • the lithium ion secondary batteries of the laminate type cells produced in the examples and comparative examples were allowed to stand for 24 hours in an environment at 25 ° C., and then 4.25 V, 0.1 C, 5 hours in an environment at 25 ° C.
  • the charging operation was performed, and the voltage V 0 at that time was measured.
  • a discharge operation was performed at a discharge rate of 1 C in an environment of ⁇ 10 ° C., and the voltage V 1 15 seconds after the start of discharge was measured.
  • Voltage drop ⁇ V is 100 mV to less than 120 mV
  • B Voltage drop ⁇ V is 120 mV to less than 140 mV
  • C Voltage drop ⁇ V is 140 mV to less than 160 mV
  • D Voltage drop ⁇ V is 160 mV to less than 180 mV
  • E Voltage drop ⁇ V is 180 mV to less than 200 mV
  • F Voltage drop ⁇ V is 200 mV or more
  • D50 was obtained from the volume distribution of the average particle diameter measured with a laser diffraction particle size distribution measuring device (LS 13, 320, manufactured by Beckman Coulter, Inc.). The value of was used.
  • Example 1 Manufacture of particulate binder
  • ion-exchanged water and sodium dodecylbenzenesulfonate were added to a reaction vessel equipped with a stirrer, a thermometer, and a cooling tube, heated to 60 ° C., and kept warm.
  • ammonium persulfate was added as a polymerization initiator, and 40 parts of an acrylamide monomer having an N-methylol group (N-methylolacrylamide), 30 parts of lithium methacrylate and 30 parts of vinyl alcohol were heated. The solution was added dropwise over 2 hours.
  • the mixture was vigorously stirred at 70 ° C. for 5 hours and kept at the same temperature.
  • the polymerization conversion rate of the monomer was 95%.
  • the reaction solution was filtered off. An emulsion in which the particulate binder was dispersed in water and sodium dodecylbenzenesulfonate was obtained. Further, the particle diameter of the particulate binder was measured and found to be 130 nm.
  • the conductive adhesive is applied to a current collector base material made of aluminum on a current collector base material at a molding speed of 20 m / min with a roll bar using a cast method, and at 60 ° C. for 1 minute. Subsequently, the film was dried at 120 ° C. for 2 minutes to form a 1 ⁇ m thick conductive adhesive layer. As a result, a current collector in which a conductive adhesive layer was formed on the current collector substrate was obtained.
  • the electrode active material layer slurry for the positive electrode was applied onto the conductive adhesive layer of the current collector at a molding speed of 20 m / min on the aluminum current collector on which the conductive adhesive layer was formed, and 120 ° C. After being dried for 5 minutes, a 5 cm square was punched out to obtain a positive electrode for a lithium ion secondary battery having an electrode active material layer having a thickness of 100 ⁇ m.
  • graphite (KS-6: manufactured by Timcal) having a volume average particle diameter of 3.7 ⁇ m is used as an active material for the negative electrode, and 1.5% aqueous solution of carboxymethyl cellulose ammonium as a dispersant (DN-800H: Daicel Chemical).
  • DN-800H Daicel Chemical
  • Kogyo Co., Ltd. 2.0 parts in terms of solid content, 5 parts of acetylene black (denka black powder: manufactured by Denki Kagaku Kogyo Co., Ltd.) as the electrode conductive material, and a glass transition temperature of ⁇ 48 ° C.
  • a 40% aqueous dispersion of a diene polymer having a number average particle size of 0.18 ⁇ m is mixed to a solid content equivalent of 3.0 parts, and ion-exchanged water is mixed so that the total solid content concentration is 35%.
  • a slurry for the electrode active material layer was prepared.
  • the negative electrode active material layer slurry was applied to one side of a 18 ⁇ m thick copper foil so that the film thickness after drying was about 100 ⁇ m. And it dried at 60 degreeC for 20 minutes, Then, it heat-processed at 150 degreeC for 20 minutes, and formed the negative electrode active material layer. Subsequently, it was rolled with a roll press and punched into a 5.2 cm square to obtain a negative electrode for a lithium ion secondary battery having a single-sided thickness of 50 ⁇ m.
  • a laminated laminate cell-shaped lithium ion secondary battery was produced.
  • an electrolytic solution a solution obtained by dissolving LiPF 6 at a concentration of 1.0 mol / liter in a mixed solvent of ethylene carbonate and diethyl carbonate in a volume ratio of 1: 2 was used.
  • the obtained lithium ion secondary battery was evaluated for high temperature cycle characteristics and low temperature output characteristics.
  • Example 2 In the production of the particulate binder, a particulate binder was produced in the same manner as in Example 1 except that styrene was used instead of vinyl alcohol. The polymerization conversion rate of the monomer was 95%. Moreover, except having used the particulate-form binder obtained in Example 2, manufacture of an adhesive composition, formation of an electroconductive adhesive layer, preparation of an electrode, and a lithium ion secondary battery similarly to Example 1 was manufactured.
  • Example 3 In the production of the particulate binder, acrylonitrile was used instead of vinyl alcohol, and the monomer charge composition in the production of the particulate binder was 33 parts N-methylolacrylamide, 17 parts lithium methacrylate and 50 parts acrylonitrile. A particulate binder was produced in the same manner as in Example 1 except that. The polymerization conversion rate of the monomer was 95%. Moreover, except having used the particulate-form binder obtained in Example 3, manufacture of an adhesive composition, formation of an electroconductive adhesive layer, preparation of an electrode, and a lithium ion secondary battery similarly to Example 1 Was manufactured.
  • Example 4 In the production of the particulate binder, an acrylamide monomer of a primary amine is used instead of an acrylamide monomer having an N-methylol group (N-methylol acrylamide), and methacrylic acid is used instead of lithium methacrylate.
  • a particulate binder was produced in the same manner as in Example 1 except that sodium was used. The polymerization conversion rate of the monomer was 95%.
  • manufacture of an adhesive composition, formation of an electroconductive adhesive layer, preparation of an electrode, and a lithium ion secondary battery similarly to Example 1 was manufactured.
  • Example 5 Particles were produced in the same manner as in Example 1 except that a primary amine acrylamide monomer was used instead of the acrylamide monomer having an N-methylol group (N-methylol acrylamide) in the production of the particulate binder.
  • the binder was produced.
  • the polymerization conversion rate of the monomer was 95%.
  • the adhesive was the same as in Example 1 except that the particulate binder obtained in Example 5 was used and carbon nanotubes (hereinafter sometimes referred to as “CNT”) were used instead of graphene.
  • CNT carbon nanotubes
  • Example 5 Except for using the adhesive composition obtained in Example 5, a conductive adhesive layer was formed, an electrode was produced, and a lithium ion secondary battery was produced in the same manner as in Example 1.
  • Example 6 Production of particulate binder in the same manner as in Example 1, except that the monomer charge composition in the production of particulate binder was changed to 50 parts N-methylolacrylamide, 30 parts lithium methacrylate, and 20 parts vinyl alcohol. Went. The polymerization conversion rate of the monomer was 95%. Moreover, except having used the particulate-form binder obtained in Example 6, manufacture of an adhesive composition, formation of an electroconductive adhesive layer, preparation of an electrode, and a lithium ion secondary battery similarly to Example 1. Was manufactured.
  • Example 7 Production of particulate binder in the same manner as in Example 1, except that the monomer charge composition in the production of particulate binder was 20 parts N-methylolacrylamide, 40 parts lithium methacrylate, and 40 parts vinyl alcohol. Went. The polymerization conversion rate of the monomer was 95%. Moreover, except having used the particulate-form binder obtained in Example 7, manufacture of an adhesive composition, formation of an electroconductive adhesive layer, preparation of an electrode, and a lithium ion secondary battery similarly to Example 1 Was manufactured.
  • Example 2 Example 1 except that N-methylolacrylamide was not used in the production of the particulate binder, and the monomer charge composition in the production of the particulate binder was changed to 70 parts lithium methacrylate and 30 parts vinyl alcohol. Similarly, a particulate binder was produced. The polymerization conversion rate of the monomer was 95%. Moreover, manufacture of an adhesive composition, formation of a conductive adhesive layer, preparation of an electrode, and a lithium ion secondary battery were performed in the same manner as in Example 1 except that the particulate binder obtained in Comparative Example 2 was used. Was manufactured.
  • the composition contains conductive carbon, a particulate binder, and water, and the particulate binder is derived from a (meth) acrylamide monomer and a (meth) acrylate monomer.
  • the lithium ion secondary battery having a conductive adhesive layer formed using an adhesive composition that is a polymer containing units had good high-temperature cycle characteristics and low-temperature output characteristics.

Abstract

The objective of the present invention is to provide: a conductive adhesive composition for electrochemical element electrodes, which is capable of forming a conductive adhesive layer that has good stability even in cases where a high-potential active material is used; and a collector for electrochemical element electrodes, which has a conductive adhesive layer that is formed from this composition. A conductive adhesive composition for electrochemical element electrodes according to the present invention contains a conductive carbon, a particulate binder and water. The particulate binder is a polymer that contains constituent units derived from a (meth)acrylic amide monomer and a (meth)acrylate monomer.

Description

電気化学素子電極用導電性接着剤組成物及び電気化学素子電極用集電体Electroconductive element electrode conductive adhesive composition and electrochemical element electrode collector
　本発明は、電極活物質層と集電体との間に設ける導電性接着剤層を形成するための電気化学素子電極用導電性接着剤組成物、この電気化学素子電極用導電性接着剤組成物により形成される導電性接着剤層を有する電気化学素子電極用集電体に関するものである。 The present invention relates to a conductive adhesive composition for an electrochemical element electrode for forming a conductive adhesive layer provided between an electrode active material layer and a current collector, and the conductive adhesive composition for an electrochemical element electrode. The present invention relates to a current collector for an electrochemical element electrode having a conductive adhesive layer formed of a material.
　小型で軽量、且つエネルギー密度が高く、さらに繰り返し充放電が可能な電気化学素子、特にリチウムイオン二次電池は、その特性を活かして急速に需要を拡大している。また、リチウムイオン二次電池に代表される電気化学素子は、エネルギー密度、出力密度が大きいことから、携帯電話やノート型パーソナルコンピュータの小型用途から、車載などの大型用途での利用が期待されている。そのため、これらの電気化学素子には、用途の拡大や発展に伴い、低抵抗化、高容量化、高耐電圧特性及び機械的特性の向上、サイクル寿命の長期化など、よりいっそうの改善が求められている。 Demand for electrochemical devices, especially lithium ion secondary batteries, which are small and light, have a high energy density, and can be repeatedly charged and discharged, is rapidly expanding due to their characteristics. Electrochemical elements typified by lithium ion secondary batteries have high energy density and output density, so they are expected to be used in small applications such as mobile phones and notebook personal computers, and in large applications such as in-vehicle applications. Yes. For this reason, these electrochemical devices are required to be further improved, such as low resistance, high capacity, high withstand voltage and mechanical properties, and longer cycle life, as their applications expand and develop. It has been.
　電気化学素子用電極は、通常、電極活物質と、必要に応じて用いられる導電性カーボンとをバインダーで結着することにより形成された電極活物質層を集電体上に積層してなるものである。ここで、電気化学素子は、有機系電解液を用いることで作動電圧を高め、かつ、エネルギー密度を高めることができるが、一方では電解液の粘度が高いために、内部抵抗が大きくなる傾向があった。そこで、内部抵抗を低減させるため、及び電極活物質層と集電体との密着性向上のために、電極活物質層と集電体との間に導電性接着剤層を設けることが提案されている。 Electrodes for electrochemical devices are usually formed by laminating an electrode active material layer formed by binding an electrode active material and conductive carbon used as necessary with a binder on a current collector. It is. Here, the electrochemical element can increase the operating voltage and the energy density by using an organic electrolytic solution, but on the other hand, since the viscosity of the electrolytic solution is high, the internal resistance tends to increase. there were. Therefore, it has been proposed to provide a conductive adhesive layer between the electrode active material layer and the current collector in order to reduce the internal resistance and improve the adhesion between the electrode active material layer and the current collector. ing.
　例えば、特許文献１においては、導電性カーボン、エチレン性不飽和力ルボン酸単量体単位、（メタ）アクリル酸エステル単量体単位およびフッ素含有（メタ）アクリル酸エステル単量体単位を含む共重合体である水溶性重合体及びバインダーを含む電気化学素子電極用導電性接着剤組成物を用いて導電性接着剤層を形成している。 For example, in Patent Document 1, a copolymer containing conductive carbon, an ethylenically unsaturated rubonic acid monomer unit, a (meth) acrylic acid ester monomer unit, and a fluorine-containing (meth) acrylic acid ester monomer unit. A conductive adhesive layer is formed using a conductive adhesive composition for an electrochemical element electrode containing a water-soluble polymer as a polymer and a binder.
国際公開第２０１３／０６２０８８号International Publication No. 2013/062088
　ところで、電気化学素子の出力を向上させるために電極活物質としてＬＣＯ（ＬｉＣｏＯ2）等の高電位活物質を用いることがある。特許文献１においてはバインダーの種類が規定されておらず、高電位活物質を使用した場合に、特許文献１の導電性接着剤層に含まれるバインダーが酸化され、導電性接着剤層の密着性が低下する虞があった。そのため、得られる電気化学素子のサイクル特性が悪化する虞があった。 By the way, in order to improve the output of an electrochemical element, a high potential active material such as LCO (LiCoO 2 ) may be used as an electrode active material. In patent document 1, the kind of binder is not prescribed | regulated, When a high potential active material is used, the binder contained in the conductive adhesive layer of patent document 1 is oxidized, and the adhesiveness of a conductive adhesive layer There was a possibility that it might fall. Therefore, the cycle characteristics of the obtained electrochemical device may be deteriorated.
　本発明の目的は、高電位活物質を用いた場合でも安定性が良好な導電性接着剤層を形成することができる電気化学素子電極用導電性接着剤組成物及びこの電気化学素子電極用導電性接着剤組成物により形成された導電性接着剤層を有する電気化学素子電極用集電体を提供することである。 An object of the present invention is to provide a conductive adhesive composition for an electrochemical element electrode capable of forming a conductive adhesive layer having good stability even when a high-potential active material is used, and the conductive for the electrochemical element electrode. It is providing the electrical power collector for electrochemical element electrodes which has the conductive adhesive layer formed of the conductive adhesive composition.
　本発明者は、上記課題を解決すべく鋭意検討を続けた結果、特定の粒子状共重合体を用いることにより、上記目的を達成できることを見出し、本発明を完成するに至った。 As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by using a specific particulate copolymer, and have completed the present invention.
　即ち、本発明によれば、
（１）　導電性カーボン、粒子状結着剤、及び水を含み、前記粒子状結着剤が（メタ）アクリルアミド単量体及び（メタ）アクリル酸塩単量体に由来する構成単位を含む重合体であることを特徴とする電気化学素子電極用導電性接着剤組成物、
（２）　前記粒子状結着剤が、（メタ）アクリルアミド単量体５～７０重量部及び（メタ）アクリル酸塩単量体１～５０重量部を含む単量体混合物（但し、単量体成分の合計を１００重量部とする）を重合して得られるものである（１）に記載の電気化学素子電極用導電性接着剤組成物、
（３）　前記（メタ）アクリル酸塩単量体が、（メタ）アクリル酸リチウム、または／および、（メタ）アクリル酸ナトリウムである（１）または（２）に記載の電気化学素子電極用導電性接着剤組成物、
（４）　前記粒子状結着剤が、ビニルアルコール、スチレンまたは（メタ）アクリロニトリルのいずれか１種類以上を含む単量体成分をさらに１０～５０重量部含む単量体混合物（但し、単量体成分の合計を１００重量部とする）を重合して得られるものである（１）～（３）のいずれかに記載の電気化学素子電極用導電性接着剤組成物、
（５）　前記粒子状結着剤の体積平均粒子径が５～５００ｎｍであることを特徴とする（１）～（４）のいずれかに記載の電気化学素子電極用導電性接着剤組成物、
（６）　前記導電性カーボンの含有割合が８～３８重量％、前記粒子状結着剤の含有割合が０．５～１０重量％、前記水の含有割合が６０～９０重量％であることを特徴とする（１）～（５）のいずれかに記載の電気化学素子電極用導電性接着剤組成物、
（７）　さらに非イオン性界面活性剤を０．０５～１重量％含むことを特徴とする（１）～（６）のいずれかに記載の電気化学素子電極用導電性接着剤組成物、
（８）　前記導電性カーボンがグラフェン、カーボンナノチューブを更に含むことを特徴とする（１）～（７）のいずれかに記載の電気化学素子電極用導電性接着剤組成物、
（９）　（１）～（８）のいずれかに記載の電気化学素子電極用導電性接着剤組成物を塗布・乾燥してなる電気化学素子電極用集電体
が提供される。 That is, according to the present invention,
(1) Heavy metal containing conductive carbon, a particulate binder, and water, wherein the particulate binder contains a structural unit derived from a (meth) acrylamide monomer and a (meth) acrylate monomer. A conductive adhesive composition for electrochemical element electrodes, characterized in that it is a coalescence,
(2) A monomer mixture in which the particulate binder comprises 5 to 70 parts by weight of a (meth) acrylamide monomer and 1 to 50 parts by weight of a (meth) acrylate monomer (provided that the monomer The conductive adhesive composition for electrochemical element electrodes according to (1), obtained by polymerizing a total of 100 parts by weight of the components,
(3) The electroconductivity for an electrochemical element electrode according to (1) or (2), wherein the (meth) acrylate monomer is lithium (meth) acrylate and / or sodium (meth) acrylate. Adhesive composition,
(4) A monomer mixture wherein the particulate binder further comprises 10 to 50 parts by weight of a monomer component containing at least one of vinyl alcohol, styrene and (meth) acrylonitrile (provided that the monomer The conductive adhesive composition for electrochemical element electrodes according to any one of (1) to (3), obtained by polymerizing a total of 100 parts by weight of the components,
(5) The conductive adhesive composition for electrochemical element electrodes according to any one of (1) to (4), wherein the volume average particle diameter of the particulate binder is 5 to 500 nm,
(6) The conductive carbon content is 8 to 38% by weight, the particulate binder content is 0.5 to 10% by weight, and the water content is 60 to 90% by weight. The conductive adhesive composition for electrochemical element electrodes according to any one of (1) to (5),
(7) The conductive adhesive composition for electrochemical element electrodes according to any one of (1) to (6), further comprising 0.05 to 1% by weight of a nonionic surfactant,
(8) The conductive adhesive composition for electrochemical element electrodes according to any one of (1) to (7), wherein the conductive carbon further contains graphene and carbon nanotubes,
(9) There is provided an electrochemical device electrode current collector obtained by applying and drying the electroconductive adhesive composition for electrochemical device electrodes according to any one of (1) to (8).
　本発明の電気化学素子電極用導電性接着剤組成物によれば、高電位活物質を用いた場合でも安定性が良好な導電性接着剤層を形成することができる。また、本発明によれば、この電気化学素子電極用導電性接着剤組成物により形成された導電性接着剤層を有する電気化学素子電極用集電体が提供される。 According to the conductive adhesive composition for electrochemical element electrodes of the present invention, a conductive adhesive layer having good stability can be formed even when a high potential active material is used. Moreover, according to this invention, the electrical power collector for electrochemical element electrodes which has the conductive adhesive layer formed with this electrically conductive adhesive composition for electrochemical element electrodes is provided.
　以下、本発明の電気化学素子電極用導電性接着剤組成物について説明する。本発明の電気化学素子電極用導電性接着剤組成物は、導電性カーボン、粒子状結着剤、及び水を含み、前記粒子状結着剤が（メタ）アクリルアミド単量体及び（メタ）アクリル酸塩単量体に由来する構成単位を含む重合体であることを特徴とする。なお、本発明において、「（メタ）アクリル」は、「アクリル」又は「メタアクリル」を意味する。 Hereinafter, the conductive adhesive composition for electrochemical element electrodes of the present invention will be described. The conductive adhesive composition for electrochemical element electrodes of the present invention comprises conductive carbon, a particulate binder, and water, and the particulate binder is a (meth) acrylamide monomer and (meth) acrylic. It is a polymer containing a structural unit derived from an acid salt monomer. In the present invention, “(meth) acryl” means “acryl” or “methacryl”.
　（導電性カーボン）
　本発明に係る電気化学素子電極用導電性接着剤組成物（以下、単に「接着剤組成物」と記載することがある。）に用いる導電性カーボンは、その形態は特に限定はされないが、炭素粒子であることが好ましい。炭素粒子とは、炭素のみからなるか、又は実質的に炭素のみからなる粒子である。その具体例としては、グラファイト（具体的には天然黒鉛、人造黒鉛など）、カーボンブラック（具体的にはアセチレンブラック、ケッチェンブラック、その他のファーネスブラック、チャンネルブラック、サーマルランプブラックなど）、炭素繊維が挙げられる。これらの中でも、グラファイト、アセチレンブラックを用いることが好ましい。 (Conductive carbon)
The form of conductive carbon used in the conductive adhesive composition for electrochemical device electrodes according to the present invention (hereinafter sometimes simply referred to as “adhesive composition”) is not particularly limited, but carbon Particles are preferred. A carbon particle is a particle which consists only of carbon, or consists only of carbon substantially. Specific examples include graphite (specifically natural graphite, artificial graphite, etc.), carbon black (specifically acetylene black, ketjen black, other furnace blacks, channel black, thermal lamp black, etc.), carbon fiber. Is mentioned. Among these, it is preferable to use graphite and acetylene black.
　また、本発明に用いる導電性カーボンは、導電性接着剤層の導電性が向上する観点及び得られる電気化学素子の出力特性が良好となる観点から、上記の導電性カーボンの成分に加えて、さらにカーボンナノチューブ、グラフェンを含むことが好ましく、グラフェンを含むことがさらに好ましい。 In addition, from the viewpoint of improving the conductivity of the conductive adhesive layer and improving the output characteristics of the obtained electrochemical element, the conductive carbon used in the present invention, in addition to the above-described conductive carbon components, Further, it preferably contains carbon nanotubes and graphene, and more preferably contains graphene.
　接着剤組成物中の導電性カーボンの含有割合は、導電性接着剤層の導電性が向上する観点及び得られる電気化学素子の出力特性が良好となる観点から、好ましくは８～３８重量％、より好ましくは１０～３５重量％、さらに好ましくは１２～３０重量％である。 The content of the conductive carbon in the adhesive composition is preferably 8 to 38% by weight from the viewpoint of improving the conductivity of the conductive adhesive layer and improving the output characteristics of the obtained electrochemical element. More preferably, it is 10 to 35% by weight, and further preferably 12 to 30% by weight.
　また、導電性カーボンがカーボンナノチューブ、グラフェンを含む場合における、接着剤組成物中のカーボンナノチューブ、グラフェンの含有割合は、導電性接着剤層の導電性が向上する観点及び得られる電気化学素子の出力特性が良好となる観点から、好ましくは０．１～１０重量％、より好ましくは０．５～９重量％、さらに好ましくは１～８重量％である。 Further, when the conductive carbon contains carbon nanotubes and graphene, the content ratio of the carbon nanotubes and graphene in the adhesive composition is the viewpoint that the conductivity of the conductive adhesive layer is improved and the output of the obtained electrochemical device From the viewpoint of improving the characteristics, it is preferably 0.1 to 10% by weight, more preferably 0.5 to 9% by weight, and still more preferably 1 to 8% by weight.
　導電性カーボンの体積平均粒子径は、良好な導電性を保つ観点から、好ましくは０．０１～２０μｍ、より好ましくは０．０５～１５μｍ、特に好ましくは０．１～１０μｍである。ここで体積平均粒子径は、レーザー回折式粒度分布測定装置（ＳＡＬＤ－３１００島津製作所製）にて測定し、算出される体積平均粒子径である。 The volume average particle diameter of the conductive carbon is preferably 0.01 to 20 μm, more preferably 0.05 to 15 μm, and particularly preferably 0.1 to 10 μm from the viewpoint of maintaining good conductivity. Here, the volume average particle diameter is a volume average particle diameter calculated by measuring with a laser diffraction particle size distribution analyzer (SALD-3100, manufactured by Shimadzu Corporation).
　導電性カーボンの電気抵抗率は、導電性接着剤層の電子移動抵抗をより低減し、リチウムイオン二次電池の内部抵抗をより低減する観点から、好ましくは０．０００１～１Ω・ｃｍであり、より好ましくは０．０００５～０．５Ω・ｃｍ、特に好ましくは０．００１～０．１Ω・ｃｍである。ここで、電気抵抗率は、粉体抵抗測定システム（ＭＣＰ－ＰＤ５１型：ダイアインスツルメンツ社製）を用いて、炭素粒子に圧力をかけ続けながら抵抗値を測定し、圧力に対して収束した抵抗値Ｒ（Ω）と、圧縮された炭素粒子層の面積Ｓ（ｃｍ2）と厚みｄ（ｃｍ）から電気抵抗率ρ（Ω・ｃｍ）＝Ｒ×（Ｓ／ｄ）を算出する。 The electrical resistivity of the conductive carbon is preferably 0.0001 to 1 Ω · cm from the viewpoint of further reducing the electron transfer resistance of the conductive adhesive layer and further reducing the internal resistance of the lithium ion secondary battery. More preferably, it is 0.0005 to 0.5 Ω · cm, and particularly preferably 0.001 to 0.1 Ω · cm. Here, the electrical resistivity is a resistance value converged with respect to the pressure measured by continuously applying pressure to the carbon particles using a powder resistance measurement system (MCP-PD51 type: manufactured by Dia Instruments). The electrical resistivity ρ (Ω · cm) = R × (S / d) is calculated from R (Ω), the area S (cm 2 ) of the compressed carbon particle layer, and the thickness d (cm).
　（粒子状結着剤）
　本発明に係る接着剤組成物に用いる粒子状結着剤は（メタ）アクリルアミド単量体及び（メタ）アクリル酸塩単量体に由来する構成単位を含む重合体である。 (Particulate binder)
The particulate binder used in the adhesive composition according to the present invention is a polymer containing structural units derived from a (meth) acrylamide monomer and a (meth) acrylate monomer.
　（メタ）アクリルアミド単量体としては、集電体と電極活物質層との密着性が良好な導電性接着剤層が得られ、また、得られるリチウムイオン二次電池の高温サイクル特性が良好となる観点から、Ｎ－メチロール（メタ）アクリルアミド、Ｎ，Ｎ－ジメチロール（メタ）アクリルアミド等のＮ－メチロール基を有するアクリルアミド単量体、及び、（メタ）アクリルアミド等の第一級アミンの（メタ）アクリルアミド単量体を用いることが好ましい。 As the (meth) acrylamide monomer, a conductive adhesive layer having good adhesion between the current collector and the electrode active material layer is obtained, and the high-temperature cycle characteristics of the obtained lithium ion secondary battery are good. In view of the above, acrylamide monomers having an N-methylol group such as N-methylol (meth) acrylamide, N, N-dimethylol (meth) acrylamide, and (meth) of primary amines such as (meth) acrylamide It is preferable to use an acrylamide monomer.
　粒子状結着剤中の（メタ）アクリルアミド単量体に由来する構成単位の含有量は、集電体と電極活物質層との密着性が良好な導電性接着剤層が得られ、また、得られるリチウムイオン二次電池の高温サイクル特性が良好となる観点から、粒子状結着剤は、単量体成分の合計を１００重量部として、（メタ）アクリルアミド単量体を、好ましくは５～７０重量部、より好ましくは１０～６０重量部、さらに好ましくは２０～５０重量部含む単量体混合物を重合して得られたものである。なお、単量体の重合転化率は好ましくは９０％以上、より好ましくは９３％以上、さらに好ましくは９５％以上であり、得られる重合体の単量体の構成単位割合は、仕込んだ単量体の混合比と一致する。 The content of the structural unit derived from the (meth) acrylamide monomer in the particulate binder can provide a conductive adhesive layer with good adhesion between the current collector and the electrode active material layer, From the viewpoint of improving the high-temperature cycle characteristics of the obtained lithium ion secondary battery, the particulate binder is a (meth) acrylamide monomer, preferably 5 to It is obtained by polymerizing a monomer mixture containing 70 parts by weight, more preferably 10 to 60 parts by weight, still more preferably 20 to 50 parts by weight. The polymerization conversion rate of the monomer is preferably 90% or more, more preferably 93% or more, and still more preferably 95% or more, and the constituent unit ratio of the monomer of the obtained polymer is the single unit charged. It corresponds to the mixing ratio of the body.
　また、（メタ）アクリル酸塩単量体としては、集電体と電極活物質層との密着性が良好な導電性接着剤層が得られ、また、得られるリチウムイオン二次電池の高温サイクル特性が良好となる観点から、（メタ）アクリル酸リチウム、（メタ）アクリル酸ナトリウムを用いることが好ましく、（メタ）アクリル酸リチウムを用いることがより好ましい。 In addition, as the (meth) acrylate monomer, a conductive adhesive layer having good adhesion between the current collector and the electrode active material layer is obtained, and a high-temperature cycle of the obtained lithium ion secondary battery From the viewpoint of good characteristics, it is preferable to use lithium (meth) acrylate and sodium (meth) acrylate, and more preferably lithium (meth) acrylate.
　粒子状結着剤中の（メタ）アクリル酸塩単量体に由来する構成単位の含有量は、集電体と電極活物質層との密着性が良好な導電性接着剤層が得られ、また、得られるリチウムイオン二次電池の高温サイクル特性が良好となる観点から、粒子状結着剤は、単量体成分の合計を１００重量部として、（メタ）アクリル酸塩単量体を、好ましくは１～５０重量部、より好ましくは５～４５重量部、さらに好ましくは１０～４０重量部、特に好ましくは２０～４０重量部含む単量体混合物を重合して得られたものである。なお、単量体の重合転化率は好ましくは９０％以上、より好ましくは９３％以上、さらに好ましくは９５％以上であり、得られる重合体の単量体の構成単位割合は、仕込んだ単量体の混合比と一致する。 The content of the structural unit derived from the (meth) acrylate monomer in the particulate binder is a conductive adhesive layer with good adhesion between the current collector and the electrode active material layer, In addition, from the viewpoint of improving the high-temperature cycle characteristics of the obtained lithium ion secondary battery, the particulate binder has a total of monomer components as 100 parts by weight, and a (meth) acrylate monomer, It is preferably obtained by polymerizing a monomer mixture containing 1 to 50 parts by weight, more preferably 5 to 45 parts by weight, still more preferably 10 to 40 parts by weight, and particularly preferably 20 to 40 parts by weight. The polymerization conversion rate of the monomer is preferably 90% or more, more preferably 93% or more, and still more preferably 95% or more, and the constituent unit ratio of the monomer of the obtained polymer is the single unit charged. It corresponds to the mixing ratio of the body.
　また、本発明に用いる粒子状結着剤は、さらに（メタ）アクリルアミド単量体及び（メタ）アクリル酸塩単量体と共重合可能な単量体（以下、「第３モノマー」ということがある。）に由来する構成単位を含んでいてもよい。 Further, the particulate binder used in the present invention is a monomer copolymerizable with a (meth) acrylamide monomer and a (meth) acrylate monomer (hereinafter referred to as “third monomer”). It may contain a structural unit derived from.
　第３モノマーとしては、本発明の効果を著しく損なわない限り特に制限はないが、導電性カーボンの分散性が良好となり、また、得られるリチウムイオン二次電池の出力特性が良好となる観点から、ビニルアルコール、スチレン、（メタ）アクリロニトリルを好ましく用いることができる。ここで、（メタ）アクリロニトリルとは、アクリロニトリルおよびメタアクリロニトリルの両者を含む意味で用いられる。すなわち、（メタ）アクリロニトリルは、アクリロニトリルあるいはメタアクリロニトリルのいずれか一方であってもよく、また両者を同時に含むものであってもよい。これらの第３モノマーは、それぞれ単独でまたは２種以上を組み合わせて使用することができる。 The third monomer is not particularly limited as long as the effects of the present invention are not significantly impaired. From the viewpoint of improving the dispersibility of the conductive carbon and improving the output characteristics of the obtained lithium ion secondary battery. Vinyl alcohol, styrene, and (meth) acrylonitrile can be preferably used. Here, (meth) acrylonitrile is used in the meaning including both acrylonitrile and methacrylonitrile. That is, (meth) acrylonitrile may be either acrylonitrile or methacrylonitrile, or may contain both at the same time. These third monomers can be used alone or in combination of two or more.
　粒子状結着剤中の第３モノマーに由来する構成単位の含有量は、導電性カーボンの分散性が良好となり、また、得られるリチウムイオン二次電池の出力特性が良好となる観点から、粒子状結着剤は、単量体成分の合計を１００重量部として、第３モノマーを、好ましくは１０～５０重量部、より好ましくは１５～４５重量部、さらに好ましくは２０～４０重量部含む単量体混合物を重合して得られたものである。なお、単量体の重合転化率は好ましくは９０％以上、より好ましくは９３％以上、さらに好ましくは９５％以上であり、得られる重合体の単量体の構成単位割合は、仕込んだ単量体の混合比と一致する。 The content of the structural unit derived from the third monomer in the particulate binder is such that the dispersibility of the conductive carbon is good and the output characteristics of the resulting lithium ion secondary battery are good. The binder is a single monomer containing 100 parts by weight of the total of the monomer components, preferably containing 10 to 50 parts by weight, more preferably 15 to 45 parts by weight, and even more preferably 20 to 40 parts by weight of the third monomer. It is obtained by polymerizing a monomer mixture. The polymerization conversion rate of the monomer is preferably 90% or more, more preferably 93% or more, and still more preferably 95% or more, and the constituent unit ratio of the monomer of the obtained polymer is the single unit charged. It corresponds to the mixing ratio of the body.
　接着剤組成物中の粒子状結着剤の含有割合は、集電体と電極活物質層との密着性が良好であり、得られる電気化学素子のサイクル特性が良好となる観点から、好ましくは０．５～１０重量％、より好ましくは１～９重量％、さらに好ましくは２～８重量％である。 The content ratio of the particulate binder in the adhesive composition is preferably from the viewpoint that the adhesion between the current collector and the electrode active material layer is good, and the cycle characteristics of the resulting electrochemical device are good. It is 0.5 to 10% by weight, more preferably 1 to 9% by weight, still more preferably 2 to 8% by weight.
　また、粒子状結着剤の体積平均粒子径は、接着剤組成物において導電性カーボン同士の密着性が向上する観点から、好ましくは５～５００ｎｍ、より好ましくは５０～４００ｎｍ、さらに好ましくは１００～３００ｎｍである。 The volume average particle diameter of the particulate binder is preferably 5 to 500 nm, more preferably 50 to 400 nm, and still more preferably 100 to 100 from the viewpoint of improving the adhesion between conductive carbons in the adhesive composition. 300 nm.
　（粒子状結着剤の製造）
　粒子状結着剤の製法は特に限定はされないが、例えば、（メタ）アクリルアミド単量体及び（メタ）アクリル酸塩単量体、必要に応じて用いられる第３モノマーを含む単量体混合物を乳化重合して得ることができる。乳化重合の方法としては、特に限定されず、従来公知の乳化重合法を採用すれば良い。 (Manufacture of particulate binder)
The production method of the particulate binder is not particularly limited. For example, a monomer mixture containing a (meth) acrylamide monomer and a (meth) acrylate monomer, and a third monomer used as necessary. It can be obtained by emulsion polymerization. The method for emulsion polymerization is not particularly limited, and a conventionally known emulsion polymerization method may be employed.
　乳化重合に使用する重合開始剤としては、たとえば、過硫酸ナトリウム、過硫酸カリウム、過硫酸アンモニウム、過リン酸カリウム、過酸化水素等の無機過酸化物；ｔ－ブチルパーオキサイド、クメンハイドロパーオキサイド、ｐ－メンタンハイドロパーオキサイド、ジ－ｔ－ブチルパーオキサイド、ｔ－ブチルクミルパーオキサイド、アセチルパーオキサイド、イソブチリルパーオキサイド、オクタノイルパーオキサイド、ベンゾイルパーオキサイド、３，５，５－トリメチルヘキサノイルパーオキサイド、ｔ－ブチルパーオキシイソブチレート等の有機過酸化物；アゾビスイソブチロニトリル、アゾビス－２，４－ジメチルバレロニトリル、アゾビスシクロヘキサンカルボニトリル、アゾビスイソ酪酸メチル等のアゾ化合物等が挙げられる。 Examples of the polymerization initiator used for emulsion polymerization include inorganic peroxides such as sodium persulfate, potassium persulfate, ammonium persulfate, potassium perphosphate, and hydrogen peroxide; t-butyl peroxide, cumene hydroperoxide, p-menthane hydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, benzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide Organic peroxides such as oxide and t-butylperoxyisobutyrate; azo compounds such as azobisisobutyronitrile, azobis-2,4-dimethylvaleronitrile, azobiscyclohexanecarbonitrile, methyl azobisisobutyrate, etc. Et That.
　これらのなかでも、無機過酸化物が好ましく使用できる。これらの重合開始剤は、それぞれ単独でまたは２種類以上を組み合わせて使用することができる。また、過酸化物開始剤は、重亜硫酸ナトリウム等の還元剤と組み合わせて、レドックス系重合開始剤として使用することもできる。
　重合開始剤の使用量は、重合に使用する単量体混合物の全量１００重量部に対して、好ましくは０．０５～５重量部、より好ましくは０．１～２重量部である。 Among these, inorganic peroxides can be preferably used. These polymerization initiators can be used alone or in combination of two or more. The peroxide initiator can also be used as a redox polymerization initiator in combination with a reducing agent such as sodium bisulfite.
The amount of the polymerization initiator used is preferably 0.05 to 5 parts by weight, more preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the total amount of the monomer mixture used for the polymerization.
　得られる粒子状結着剤のテトラヒドロフラン不溶解分量を調節するために、乳化重合時に連鎖移動剤を使用することが好ましい。連鎖移動剤としては、たとえば、ｎ－ヘキシルメルカプタン、ｎ－オクチルメルカプタン、ｔ－オクチルメルカプタン、ｎ－ドデシルメルカプタン、ｔ－ドデシルメルカプタン、ｎ－ステアリルメルカプタン等のアルキルメルカプタン；ジメチルキサントゲンジサルファイド、ジイソプロピルキサントゲンジサルファイド等のキサントゲン化合物；ターピノレンや、テトラメチルチウラムジスルフィド、テトラエチルチウラムジスルフィド、テトラメチルチウラムモノスルフィド等のチウラム系化合物；２，６－ジ－ｔ－ブチル－４－メチルフェノール、スチレン化フェノール等のフェノール系化合物；アリルアルコール等のアリル化合物；ジクロルメタン、ジブロモメタン、四臭化炭素等のハロゲン化炭化水素化合物；チオグリコール酸、チオリンゴ酸、２－エチルヘキシルチオグリコレート、ジフェニルエチレン、α－メチルスチレンダイマーなどが挙げられる。 It is preferable to use a chain transfer agent at the time of emulsion polymerization in order to adjust the amount of insoluble tetrahydrofuran in the resulting particulate binder. Examples of the chain transfer agent include alkyl mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, t-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-stearyl mercaptan; dimethylxanthogen disulfide, diisopropylxanthogendi Xanthogen compounds such as sulfide; thiuram compounds such as terpinolene, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetramethylthiuram monosulfide; phenols such as 2,6-di-t-butyl-4-methylphenol and styrenated phenol Compounds; allyl compounds such as allyl alcohol; halogenated hydrocarbon compounds such as dichloromethane, dibromomethane, carbon tetrabromide; thioglycolic acid, Oringo acid, 2-ethylhexyl thioglycolate, diphenylethylene, etc. α- methylstyrene dimer.
　これらのなかでも、アルキルメルカプタンが好ましく、ｔ－ドデシルメルカプタンがより好ましく使用できる。これらの連鎖移動剤は、単独または２種以上組み合わせて使用することができる。連鎖移動剤の使用量は、単量体混合物１００重量部に対して、好ましくは０．０５～２重量部、より好ましくは０．１～１重量部である。 Of these, alkyl mercaptans are preferable, and t-dodecyl mercaptan can be more preferably used. These chain transfer agents can be used alone or in combination of two or more. The amount of chain transfer agent used is preferably 0.05 to 2 parts by weight, more preferably 0.1 to 1 part by weight, per 100 parts by weight of the monomer mixture.
　乳化重合時に、さらにアニオン性界面活性剤を使用することが好ましい。アニオン性界面活性剤を使用することにより、重合安定性を向上させることができる。アニオン性界面活性剤としては、乳化重合において従来公知のものが使用できる。アニオン性界面活性剤の具体例としては、ナトリウムラウリルサルフェート、アンモニウムラウリルサルフェート、ナトリウムドデシルサルフェート、アンモニウムドデシルサルフェート、ナトリウムオクチルサルフェート、ナトリウムデシルサルフェート、ナトリウムテトラデシルサルフェート、ナトリウムヘキサデシルサルフェート、ナトリウムオクタデシルサルフェートなどの高級アルコールの硫酸エステル塩；ドデシルベンゼンスルホン酸ナトリウム、ラウリルベンゼンスルホン酸ナトリウム、ヘキサデシルベンゼンスルホン酸ナトリウムなどのアルキルベンゼンスルホン酸塩；ラウリルスルホン酸ナトリウム、ドデシルスルホン酸ナトリウム、テトラデシルスルホン酸ナトリウムなどの脂肪族スルホン酸塩；などが挙げられる。 It is preferable to use an anionic surfactant during emulsion polymerization. By using an anionic surfactant, the polymerization stability can be improved. As the anionic surfactant, conventionally known anionic surfactants can be used in emulsion polymerization. Specific examples of the anionic surfactant include sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecyl sulfate, ammonium dodecyl sulfate, sodium octyl sulfate, sodium decyl sulfate, sodium tetradecyl sulfate, sodium hexadecyl sulfate, sodium octadecyl sulfate and the like. Sulfuric acid ester salts of higher alcohols; alkylbenzene sulfonates such as sodium dodecylbenzene sulfonate, sodium lauryl benzene sulfonate, sodium hexadecyl benzene sulfonate; fats such as sodium lauryl sulfonate, sodium dodecyl sulfonate, sodium tetradecyl sulfonate Group sulfonates; and the like.
　アニオン性界面活性剤の使用量は、単量体混合物１００重量部に対して、好ましくは０．５～１０重量部、より好ましくは１～５重量部である。この使用量が少ないと、得られる粒子の粒子径が大きくなり、使用量が多いと粒子径が小さくなる傾向がある。また、アニオン性界面活性剤に加えて、ノニオン性界面活性剤、カチオン性界面活性剤、両性界面活性剤などを併用することもできる。 The amount of the anionic surfactant used is preferably 0.5 to 10 parts by weight, more preferably 1 to 5 parts by weight with respect to 100 parts by weight of the monomer mixture. When the amount used is small, the particle diameter of the obtained particles is large, and when the amount is large, the particle diameter tends to be small. Moreover, in addition to an anionic surfactant, a nonionic surfactant, a cationic surfactant, an amphoteric surfactant, etc. can also be used together.
　さらに乳化重合の際に、水酸化ナトリウム、アンモニアなどのｐＨ調整剤；分散剤、キレート剤、酸素捕捉剤、ビルダー、粒子径調節のためのシードラテックスなどの各種添加剤を適宜使用することができる。特にシードラテックスを用いた乳化重合が好ましい。シードラテックスとは、乳化重合の際に反応の核となる微小粒子の分散液をいう。微小粒子は粒子径が１００ｎｍ以下であることが多い。微小粒子は特に限定はされず、アクリル系重合体などの汎用の重合体が用いられる。シード重合法によれば、比較的粒子径の揃った粒子状結着剤が得られる。 Further, in the emulsion polymerization, various additives such as a pH adjusting agent such as sodium hydroxide and ammonia; a dispersing agent, a chelating agent, an oxygen scavenger, a builder, and a seed latex for adjusting the particle size can be appropriately used. . In particular, emulsion polymerization using a seed latex is preferred. Seed latex refers to a dispersion of fine particles that becomes the nucleus of the reaction during emulsion polymerization. The fine particles often have a particle size of 100 nm or less. The fine particles are not particularly limited, and general-purpose polymers such as acrylic polymers are used. According to the seed polymerization method, a particulate binder having a relatively uniform particle diameter can be obtained.
　重合反応を行う際の重合温度は、特に限定されないが、通常、０～１００℃、好ましくは４０～８０℃とする。このような温度範囲で乳化重合し、所定の重合転化率で、重合停止剤を添加したり、重合系を冷却したりして、重合反応を停止する。重合反応を停止する重合転化率は、好ましくは９３重量％以上、より好ましくは９５重量％以上である。 The polymerization temperature for carrying out the polymerization reaction is not particularly limited, but is usually 0 to 100 ° C., preferably 40 to 80 ° C. Emulsion polymerization is performed in such a temperature range, and the polymerization reaction is stopped at a predetermined polymerization conversion rate by adding a polymerization terminator or cooling the polymerization system. The polymerization conversion rate for stopping the polymerization reaction is preferably 93% by weight or more, more preferably 95% by weight or more.
　重合反応を停止した後、所望により、未反応単量体を除去し、ｐＨや固形分濃度を調整して、粒子状結着剤が分散媒に分散された形態（ラテックス）で得られる。その後、必要に応じ、分散媒を置換してもよく、また分散媒を蒸発し、粒子状結着剤を粉末形状で得ても良い。 After stopping the polymerization reaction, if desired, the unreacted monomer is removed, the pH and solid content concentration are adjusted, and the particulate binder is obtained in a form (latex) dispersed in a dispersion medium. Thereafter, if necessary, the dispersion medium may be replaced, or the dispersion medium may be evaporated to obtain the particulate binder in powder form.
　得られる粒子状結着剤の分散液には、公知の分散剤、増粘剤、老化防止剤、消泡剤、防腐剤、抗菌剤、ブリスター防止剤、ｐＨ調整剤などを必要に応じて添加することができる。 Addition of known dispersants, thickeners, anti-aging agents, antifoaming agents, antiseptics, antibacterial agents, anti-blistering agents, pH adjusters, etc., to the resulting particulate binder dispersion can do.
　（接着剤組成物）
　本発明に係る電気化学素子電極用導電性接着剤組成物は、導電性カーボン、粒子状結着剤、及び水を含む。また、接着剤組成物は、導電性カーボン、粒子状結着剤が水に分散されたスラリー状の組成物であることが好ましい。 (Adhesive composition)
The conductive adhesive composition for electrochemical element electrodes according to the present invention contains conductive carbon, a particulate binder, and water. The adhesive composition is preferably a slurry composition in which conductive carbon and a particulate binder are dispersed in water.
　各成分の含有割合は特に限定はされないが、各成分の分散性や塗工性の観点から、上記した含有割合であることが好ましい。即ち、接着剤組成物中の導電性カーボンの含有割合は好ましくは８～３８重量％、より好ましくは１０～３５重量％、さらに好ましくは１２～３０重量％であり、粒子状結着剤の含有割合は、好ましくは０．５～１０重量％、より好ましくは１～９重量％、さらに好ましくは２～８重量％である。残部は、水および必要に応じて添加される各種成分である。水の含有割合は、接着剤組成物の粘度を所望のものとし、均一な導電性接着剤層の形成が可能である観点から、好ましくは６０～９０重量％、より好ましくは６２～８８重量％、さらに好ましくは６５～８５重量％である。 分散媒の含有割合が大きすぎると、接着剤組成物により形成される導電性接着剤層の導電性が低下し、また、接着剤組成物のアルミニウム等からなる集電体用基材に対する濡れ性が低下する。また、分散媒の含有割合が小さすぎると、接着剤組成物の粘度が増加し、塗工に適さない。 The content ratio of each component is not particularly limited, but from the viewpoint of dispersibility and coatability of each component, the content ratio described above is preferable. That is, the content of the conductive carbon in the adhesive composition is preferably 8 to 38% by weight, more preferably 10 to 35% by weight, and further preferably 12 to 30% by weight. The ratio is preferably 0.5 to 10% by weight, more preferably 1 to 9% by weight, and still more preferably 2 to 8% by weight. The balance is water and various components added as necessary. The water content is preferably 60 to 90% by weight, more preferably 62 to 88% by weight from the viewpoint that the viscosity of the adhesive composition is desired and a uniform conductive adhesive layer can be formed. More preferably, it is 65 to 85% by weight. If the content ratio of the dispersion medium is too large, the conductivity of the conductive adhesive layer formed by the adhesive composition is lowered, and the wettability of the adhesive composition to the current collector substrate made of aluminum or the like is reduced. Decreases. Moreover, when the content rate of a dispersion medium is too small, the viscosity of an adhesive composition will increase and it is not suitable for coating.
　分散媒として水を用いることにより、直接接着剤組成物を製造することができるため、製造工程の簡素化を図ることができる。また、水を分散媒として用いることにより、作業環境の向上を図ることができる。 Since the adhesive composition can be directly produced by using water as the dispersion medium, the production process can be simplified. Moreover, the working environment can be improved by using water as a dispersion medium.
　さらに本発明の電気化学素子電極用導電性接着剤組成物には、界面活性剤が含まれていても良い。界面活性剤としては、ノニオン系界面活性剤を好ましく用いることができる。ノニオン系界面活性剤としては、ポリオキシアルキレンアルキルアリールエーテル界面活性剤、ポリオキシアルキレンアルキルエーテル界面活性剤、ポリオキシアルキレン脂肪酸エステル界面活性剤、ソルビタン脂肪酸エステル界面活性剤、シリコーン系界面活性剤、アセチレンアルコール系界面活性剤、含フッ素界面活性剤等が挙げられる。 Furthermore, the conductive adhesive composition for electrochemical element electrodes of the present invention may contain a surfactant. As the surfactant, a nonionic surfactant can be preferably used. Nonionic surfactants include polyoxyalkylene alkyl aryl ether surfactants, polyoxyalkylene alkyl ether surfactants, polyoxyalkylene fatty acid ester surfactants, sorbitan fatty acid ester surfactants, silicone surfactants, acetylenes Examples include alcohol surfactants and fluorine-containing surfactants.
　ポリオキシアルキレンアルキルアリールエーテル界面活性剤としては、ポリオキシエチレンノニルフェニルエーテル、ポリオキシエチレンオクチルフェニルエーテル、ポリオキシエチレンドデシルフェニルエーテルを挙げることができる。 Examples of the polyoxyalkylene alkyl aryl ether surfactant include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, and polyoxyethylene dodecyl phenyl ether.
　ポリオキシアルキレンアルキルエーテル界面活性剤としては、ポリオキシエチレンオレイルエーテル、ポリオキシエチレンラウリルエーテルを挙げることができる。 Examples of the polyoxyalkylene alkyl ether surfactant include polyoxyethylene oleyl ether and polyoxyethylene lauryl ether.
　ポリオキシアルキレン脂肪酸エステル界面活性剤としては、ポリオキシエチレンオレイン酸エステル、ポリオキシエチレンラウリン酸エステル、ポリオキシエチレンジステアリン酸エステルを挙げることができる。 Examples of the polyoxyalkylene fatty acid ester surfactant include polyoxyethylene oleate, polyoxyethylene laurate, and polyoxyethylene distearate.
　ソルビタン脂肪酸エステル界面活性剤としては、ソルビタンラウレート、ソルビタンモノステアレート、ソルビタンモノオレエート、ソルビタンセスキオレエート、ポリオキシエチレンモノオレエート、ポリオキシエチレンステアレート等を挙げることができる。
　シリコーン系界面活性剤としては、ジメチルポリシロキサン等を挙げることができる。 Examples of the sorbitan fatty acid ester surfactant include sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, and polyoxyethylene stearate.
Examples of silicone surfactants include dimethylpolysiloxane.
　アセチレンアルコール系界面活性剤としては、２，４，７，９－テトラメチル－５－デシン－４，７－ジオール、３，６－ジメチル－４－オクチン－３，６－ジオール、３，５－ジメチル－１－ヘキシン－３オール等を挙げることができる。
　含フッ素系界面活性剤としては、フッ素アルキルエステル等を挙げることができる。
　これらの界面活性剤は、それぞれ単独でまたは２種以上を組み合わせて使用できる。 Examples of acetylene alcohol surfactants include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5- Examples thereof include dimethyl-1-hexyne-3ol.
Examples of fluorine-containing surfactants include fluorine alkyl esters.
These surfactants can be used alone or in combination of two or more.
　接着剤組成物における界面活性剤の含有割合は、接着剤組成物が集電体用基材にはじかれることなく、泡立ちが抑制され、均一な導電性接着剤層が得られる観点から、好ましくは０．０５～１重量％、より好ましくは０．１～０．９重量％、さらに好ましくは０．２～０．８重量％である。 The content ratio of the surfactant in the adhesive composition is preferably from the viewpoint that foaming is suppressed and the uniform conductive adhesive layer is obtained without the adhesive composition being repelled by the current collector substrate. 0.05 to 1% by weight, more preferably 0.1 to 0.9% by weight, still more preferably 0.2 to 0.8% by weight.
　また、本発明の接着剤組成物は、防腐剤を含んでいることが好ましい。防腐剤の具体例としては、イソチアゾリン系化合物やハロゲン化脂肪族ニトロアルコールなどが挙げられるが、本発明において、イソチアゾリン系化合物を好ましく用いることができる。 The adhesive composition of the present invention preferably contains a preservative. Specific examples of the preservative include isothiazoline compounds and halogenated aliphatic nitro alcohols. In the present invention, isothiazoline compounds can be preferably used.
　なお、本発明において、本発明の効果を妨げない範囲において、上記以外の防腐剤も使用することができ、さらに防腐剤は、それぞれ単独でまたは２種以上の組み合わせで使用することもできる。 In the present invention, antiseptics other than those described above can be used as long as the effects of the present invention are not hindered, and the antiseptics can be used alone or in combination of two or more.
　さらに、本発明の接着剤組成物には、上記の成分に加えて、上記以外のバインダー、増粘剤、老化防止剤、消泡剤、抗菌剤、ブリスター防止剤、ｐＨ調整剤などを必要に応じて添加することができる。 Furthermore, in addition to the above components, the adhesive composition of the present invention requires binders, thickeners, anti-aging agents, antifoaming agents, antibacterial agents, anti-blistering agents, pH adjusting agents and the like other than those described above. Can be added accordingly.
　（集電体）
　本発明の集電体は、例えば、上記の接着剤組成物を集電体用基材上に塗布乾燥することにより得られる。即ち、集電体用基材上に導電性接着剤層を形成することにより得られる。 (Current collector)
The current collector of the present invention can be obtained, for example, by applying and drying the above adhesive composition on a current collector substrate. That is, it can be obtained by forming a conductive adhesive layer on the current collector substrate.
　集電体用基材の材料は、例えば、金属、炭素、導電性高分子などであり、好適には金属が用いられる。集電体用金属としては、通常、アルミニウム、白金、ニッケル、タンタル、チタン、ステンレス鋼、銅、その他の合金等が使用される。これらの中で導電性、耐電圧性の面から銅、アルミニウムまたはアルミニウム合金を使用するのが好ましい。
　集電体用基材の厚みは、１～１００μｍで、好ましくは２～７０μｍ、特に好ましくは５～５０μｍである。 The material of the current collector base material is, for example, metal, carbon, conductive polymer, etc., and metal is preferably used. As the current collector metal, aluminum, platinum, nickel, tantalum, titanium, stainless steel, copper, other alloys and the like are usually used. Among these, it is preferable to use copper, aluminum, or an aluminum alloy in terms of conductivity and voltage resistance.
The thickness of the current collector substrate is 1 to 100 μm, preferably 2 to 70 μm, particularly preferably 5 to 50 μm.
　導電性接着剤層の形成方法は、特に制限されない。例えば、ドクターブレード法、ディップ法、リバースロール法、ダイレクトロール法、グラビア法、エクストルージョン法、ハケ塗りなどによって、集電体用基材上に導電性接着剤層が形成される。また、剥離紙上に、導電性接着剤層を形成した後に、これを集電体用基材に転写してもよい。 The method for forming the conductive adhesive layer is not particularly limited. For example, the conductive adhesive layer is formed on the current collector substrate by a doctor blade method, a dip method, a reverse roll method, a direct roll method, a gravure method, an extrusion method, a brush coating, or the like. Moreover, after forming the conductive adhesive layer on the release paper, it may be transferred to the current collector substrate.
　導電性接着剤層の乾燥方法としては、例えば温風、熱風、低湿風による乾燥、真空乾燥、（遠）赤外線や電子線などの照射による乾燥法が挙げられる。中でも、熱風による乾燥法、遠赤外線の照射による乾燥法が好ましい。乾燥温度と乾燥時間は、集電体用基材上に塗布した接着剤組成物中の分散媒（水）を完全に除去できる温度と時間が好ましく、乾燥温度は好ましくは５０～３００℃、より好ましくは８０～２５０℃である。乾燥時間は、好ましくは２時間以下、より好ましくは５秒～３０分である。 Examples of the method for drying the conductive adhesive layer include drying by hot air, hot air, low-humidity air, vacuum drying, and drying by irradiation with (far) infrared rays or electron beams. Of these, a drying method using hot air and a drying method using irradiation with far infrared rays are preferable. The drying temperature and the drying time are preferably a temperature and a time at which the dispersion medium (water) in the adhesive composition coated on the current collector substrate can be completely removed, and the drying temperature is preferably 50 to 300 ° C. The temperature is preferably 80 to 250 ° C. The drying time is preferably 2 hours or less, more preferably 5 seconds to 30 minutes.
　導電性接着剤層の厚みは、導電性接着剤層を介して電極活物質層と集電体とが良好に密着し、得られる電気化学素子の出力特性が良好となる観点から、好ましくは０．５～５μｍ、より好ましくは０．６～４μｍ、さらに好ましくは０．７～３μｍである。
　導電性接着剤層は、接着剤組成物の固形分組成に応じた組成を有し、導電性カーボン、粒子状結着剤、及び必要に応じて用いられる成分を含む。 The thickness of the conductive adhesive layer is preferably 0 from the viewpoint of good adhesion between the electrode active material layer and the current collector through the conductive adhesive layer, and the output characteristics of the resulting electrochemical element are good. 0.5 to 5 μm, more preferably 0.6 to 4 μm, and even more preferably 0.7 to 3 μm.
The conductive adhesive layer has a composition corresponding to the solid composition of the adhesive composition, and includes conductive carbon, a particulate binder, and components used as necessary.
　（電気化学素子用電極）
　本発明の電気化学素子用電極は、上記集電体の導電性接着剤層上に電極活物質層を有する。電極活物質層は、電極活物質および電極用バインダー、必要に応じて用いられる電極用導電材とからなり、これら成分を含む電極活物質層用スラリーを用いて形成される。 (Electrodes for electrochemical devices)
The electrode for an electrochemical element of the present invention has an electrode active material layer on the conductive adhesive layer of the current collector. The electrode active material layer is composed of an electrode active material, an electrode binder, and an electrode conductive material used as necessary, and is formed using an electrode active material layer slurry containing these components.
　（電極活物質）
　電極活物質は負極活物質であってもよく、また正極活物質であってもよい。電極活物質は、電池内で電子の受け渡しをする物質である。 (Electrode active material)
The electrode active material may be a negative electrode active material or a positive electrode active material. The electrode active material is a material that transfers electrons in the battery.
　正極活物質としては、リチウムイオンの吸蔵放出が可能な活物質が用いられ、リチウムイオン二次電池用の正極活物質としては、無機化合物からなるものと有機化合物からなるものとに大別される。 As the positive electrode active material, an active material capable of occluding and releasing lithium ions is used, and the positive electrode active material for lithium ion secondary batteries is roughly classified into those made of inorganic compounds and those made of organic compounds. .
　無機化合物からなる正極活物質としては、遷移金属酸化物、遷移金属硫化物、リチウムと遷移金属とのリチウム含有複合金属酸化物などが挙げられる。上記の遷移金属としては、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ、Ｍｏ等が使用される。 Examples of the positive electrode active material made of an inorganic compound include transition metal oxides, transition metal sulfides, lithium-containing composite metal oxides of lithium and transition metals, and the like. Examples of the transition metal include Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Mo.
　遷移金属酸化物としては、ＭｎＯ、ＭｎＯ2、Ｖ2Ｏ5、Ｖ6Ｏ13、ＴｉＯ2、Ｃｕ2Ｖ2Ｏ3、非晶質Ｖ2Ｏ－Ｐ2Ｏ5、ＭｏＯ3等が挙げられる。 Examples of the transition metal oxide include MnO, MnO 2 , V 2 O 5 , V 6 O 13 , TiO 2 , Cu 2 V 2 O 3 , amorphous V 2 O—P 2 O 5 , MoO 3 and the like. .
　遷移金属硫化物としては、ＴｉＳ2、ＴｉＳ3、非晶質ＭｏＳ2、ＦｅＳ等が挙げられる。リチウム含有複合金属酸化物としては、層状構造を有するリチウム含有複合金属酸化物、スピネル構造を有するリチウム含有複合金属酸化物、オリビン型構造を有するリチウム含有複合金属酸化物などが挙げられる。 The transition metal sulfide, TiS 2, TiS 3, amorphous MoS 2, FeS, and the like. Examples of the lithium-containing composite metal oxide include a lithium-containing composite metal oxide having a layered structure, a lithium-containing composite metal oxide having a spinel structure, and a lithium-containing composite metal oxide having an olivine structure.
　層状構造を有するリチウム含有複合金属酸化物としては、リチウム含有コバルト酸化物（ＬｉＣｏＯ2、（以下、「ＬＣＯ」ということがある。））、リチウム含有ニッケル酸化物（ＬｉＮｉＯ2）、Ｃｏ－Ｎｉ－Ｍｎのリチウム複合酸化物、Ｎｉ－Ｍｎ－Ａｌのリチウム複合酸化物、Ｎｉ－Ｃｏ－Ａｌのリチウム複合酸化物、ＬｉＭａＯ2とＬｉ2ＭｂＯ3の固溶体である、ｘＬｉＭａＯ2・（１－ｘ）Ｌｉ2ＭｂＯ3　（０＜ｘ＜１、Ｍａは平均酸化状態が３＋である一つ以上の遷移金属、Ｍｂは平均酸化状態が４＋である一つ以上の遷移金属）等が挙げられる。二次電池のサイクル特性を向上させるという観点からは、ＬｉＣｏＯ2、を用いることが好ましく、二次電池のエネルギー密度を向上させるという観点からは、ＬｉＭａＯ2とＬｉ2ＭｂＯ3の固溶体が好ましい。また、ＬｉＭａＯ2とＬｉ2ＭｂＯ3の固溶体としては、特に、ｘＬｉＭａＯ2・（１－ｘ）Ｌｉ2ＭｂＯ3（０＜ｘ＜１、Ｍａ＝Ｎｉ，Ｃｏ，Ｍｎ，Ｆｅ，Ｔｉ等、Ｍｂ＝Ｍｎ、Ｚｒ、Ｔｉ等）が好ましく、中でもｘＬｉＭａＯ2・（１－ｘ）Ｌｉ2ＭｎＯ3（０＜ｘ＜１、Ｍａ＝Ｎｉ，Ｃｏ，Ｍｎ，Ｆｅ，Ｔｉ等）が好ましい。また、容量が高く、入手しやすいという観点から、Ｃｏ－Ｎｉ－Ｍｎのリチウム複合酸化物を用いることが好ましい。 Examples of the lithium-containing composite metal oxide having a layered structure include lithium-containing cobalt oxide (LiCoO 2 , (hereinafter sometimes referred to as “LCO”)), lithium-containing nickel oxide (LiNiO 2 ), and Co—Ni—. Mn lithium composite oxide, Ni—Mn—Al lithium composite oxide, Ni—Co—Al lithium composite oxide, a solid solution of LiMaO 2 and Li 2 MbO 3 , xLiMaO 2. (1-x) Li 2 MbO 3 (0 <x <1, Ma is one or more transition metals whose average oxidation state is 3+, and Mb is one or more transition metals whose average oxidation state is 4+). From the viewpoint of improving the cycle characteristics of the secondary battery, LiCoO 2 is preferably used, and from the viewpoint of improving the energy density of the secondary battery, a solid solution of LiMaO 2 and Li 2 MbO 3 is preferable. Further, as a solid solution of LiMaO 2 and Li 2 MbO 3 , in particular, xLiMaO 2. (1-x) Li 2 MbO 3 (0 <x <1, Ma = Ni, Co, Mn, Fe, Ti, etc., Mb = Mn, Zr, Ti, etc.) are preferred, and xLiMaO 2. (1-x) Li 2 MnO 3 (0 <x <1, Ma = Ni, Co, Mn, Fe, Ti, etc.) is particularly preferred. In view of high capacity and easy availability, it is preferable to use a Co—Ni—Mn lithium composite oxide.
　スピネル構造を有するリチウム含有複合金属酸化物としては、リチウムマンガン複合酸化物であるマンガン酸リチウム(ＬｉＭｎ2Ｏ4）のＭｎの一部を他の遷移金属で置換したＬｉa［Ｍｎ2-xＭｄx］Ｏ4（ここでＭｄは平均酸化状態が４＋である１つ以上の遷移金属、Ｍｄ＝Ｎｉ，Ｃｏ，Ｆｅ，Ｃｕ，Ｃｒ等、０＜ｘ＜１、０≦ａ≦１）等が挙げられる。スピネル構造を有するリチウム含有金属酸化物の中でも、ＭｎをＦｅで置換したＬｉaＦｅxＭｎ2-xＯ4-z（０≦ａ≦１、０＜ｘ＜１、０≦ｚ≦０．１）は、コストが安価であることから好ましく、ＭｎをＮｉで置換したＬｉＮｉ0.5Ｍｎ1.5Ｏ4などは構造劣化の因子と考えられているＭｎ3+を全て置換することができ、Ｎｉ2+からＮｉ4+への電気化学反応をすることから高い作動電圧で、かつ、高い容量を有することができるので、好ましい。 As the lithium-containing composite metal oxide having a spinel structure, Li a [Mn 2−x Md in which part of Mn of lithium manganate (LiMn 2 O 4 ), which is a lithium manganese composite oxide, is substituted with another transition metal. x ] O 4 (where Md is one or more transition metals having an average oxidation state of 4+, Md = Ni, Co, Fe, Cu, Cr, etc., 0 <x <1, 0 ≦ a ≦ 1) Can be mentioned. Among the lithium-containing metal oxide having a spinel structure, Li a was replaced with Mn in Fe Fe x Mn 2-x O 4-z (0 ≦ a ≦ 1,0 <x <1,0 ≦ z ≦ 0.1 ) is preferably since the cost is inexpensive, such as LiNi 0.5 Mn 1.5 O 4 obtained by replacing Mn with Ni can be replaced all the Mn 3+, which is thought to factor structural deterioration, the Ni 2+ The electrochemical reaction to Ni 4+ is preferable because it can have a high operating voltage and a high capacity.
　オリビン型構造を有するリチウム含有複合金属酸化物としては、ＬｉyＭｃＰＯ4（式中、Ｍｃは平均酸化状態が３＋である１つ以上の遷移金属、Ｍｃ＝Ｍｎ，Ｃｏ，Ｆｅ等、０≦ｙ≦２）であらわされるオリビン型燐酸リチウム化合物が挙げられる。Ｍｎ，ＣｏまたはＦｅは他の金属で一部置換されていてもよく、置換しうる金属としてはＣｕ，Ｍｇ，Ｚｎ，Ｖ，Ｃａ，Ｓｒ，Ｂａ，Ｔｉ，Ａｌ，Ｓｉ，Ｂ及びＭｏなどが挙げられる。 Examples of lithium-containing composite metal oxides having an olivine structure include Li y McPO 4 (wherein Mc is one or more transition metals having an average oxidation state of 3+, Mc = Mn, Co, Fe, etc., 0 ≦ y An olivine type lithium phosphate compound represented by ≦ 2) may be mentioned. Mn, Co or Fe may be partially substituted with other metals, and examples of metals that can be substituted include Cu, Mg, Zn, V, Ca, Sr, Ba, Ti, Al, Si, B, and Mo. Can be mentioned.
　その他、Ｌｉ2ＭｅＳｉＯ4（ここでＭｅは、Ｆｅ，Ｍｎ）等のポリアニオン構造を有する正極活物質や、ペロブスカイト構造を有するＬｉＦｅＦ3、斜方晶構造を有するＬｉ2Ｃｕ2Ｏ4などが挙げられる。 Other examples include a positive electrode active material having a polyanion structure such as Li 2 MeSiO 4 (where Me is Fe, Mn), LiFeF 3 having a perovskite structure, Li 2 Cu 2 O 4 having an orthorhombic structure, and the like. .
　有機化合物としては、例えば、ポリアセチレン、ポリ－ｐ－フェニレンなどの導電性高分子を用いることもできる。電気伝導性に乏しい、鉄系酸化物は、還元焼成時に炭素源物質を存在させることで、炭素材料で覆われた電極活物質として用いてもよい。また、これら化合物は、部分的に元素置換したものであってもよい。正極活物質は、上記の無機化合物と有機化合物の混合物であってもよい。 As the organic compound, for example, a conductive polymer such as polyacetylene or poly-p-phenylene can be used. An iron-based oxide having poor electrical conductivity may be used as an electrode active material covered with a carbon material by allowing a carbon source material to be present during reduction firing. These compounds may be partially element-substituted. The positive electrode active material may be a mixture of the above inorganic compound and organic compound.
　上述した正極活物質の中でも、高電位向けの活物質（高電位活物質）を用いることが好ましい。ここで、高電位向けの活物質とは、より高電位まで充電され得る活物質を表す。具体的には、リチウムに対して、通常４．０Ｖ以上、好ましくは４．２Ｖ以上、より好ましくは４．３Ｖ以上の電位まで充電され得るものが望ましい。ここで、「リチウムに対する電位」とは、リチウム金属が非水電解液中で示す電位に対しての値であり、「充電され得る電位」とは、それぞれの正極活物質を用いる正極の作動電位において高電位側の値を表す。 Among the positive electrode active materials described above, it is preferable to use an active material for high potential (high potential active material). Here, the active material for high potential represents an active material that can be charged to a higher potential. Specifically, lithium that can be charged to a potential of usually 4.0 V or higher, preferably 4.2 V or higher, more preferably 4.3 V or higher is desirable. Here, “potential with respect to lithium” is a value with respect to the potential that lithium metal exhibits in the non-aqueous electrolyte, and “potential that can be charged” refers to the operating potential of the positive electrode using each positive electrode active material. Represents the value on the high potential side.
　正極活物質の好ましい具体例としては、オリビン型燐酸リチウム化合物、リチウム含有コバルト酸化物、リチウム含有ニッケル酸化物、およびリチウムマンガン複合酸化物などが挙げられる。また、さらに高電位まで充電し得る正極活物質として、リチウム－マンガン－ニッケル複合酸化物などを用いてもよい。これらの正極活物質は、作用電位が高いことに加えて電池容量も大きく、大きなエネルギー密度を有する。これらの中でも、より高電位まで充電され得る点で、リチウム含有コバルト酸化物、リチウム含有ニッケル酸化物及びリチウム－マンガン－ニッケル複合酸化物が好ましく、リチウム含有コバルト酸化物（ＬＣＯ）が特に好ましい。 Specific examples of preferable positive electrode active materials include olivine type lithium phosphate compounds, lithium-containing cobalt oxides, lithium-containing nickel oxides, and lithium-manganese composite oxides. Further, a lithium-manganese-nickel composite oxide or the like may be used as a positive electrode active material that can be charged to a higher potential. These positive electrode active materials have a large energy density in addition to a high working potential, a large battery capacity. Among these, lithium-containing cobalt oxide, lithium-containing nickel oxide and lithium-manganese-nickel composite oxide are preferable, and lithium-containing cobalt oxide (LCO) is particularly preferable in that it can be charged to a higher potential.
　負極活物質としては、グラファイトやコークス等の炭素の同素体が挙げられる。前記炭素の同素体からなる負極活物質は、金属、金属塩、酸化物などとの混合体や被覆体の形態で利用することも出来る。また、負極活物質としては、ケイ素、錫、亜鉛、マンガン、鉄、ニッケル等の酸化物や硫酸塩、金属リチウム、Ｌｉ－Ａｌ、Ｌｉ－Ｂｉ－Ｃｄ、Ｌｉ－Ｓｎ－Ｃｄ等のリチウム合金、リチウム遷移金属窒化物、シリコーン等を使用できる。 Examples of the negative electrode active material include carbon allotropes such as graphite and coke. The negative electrode active material composed of the allotrope of carbon can also be used in the form of a mixture with a metal, a metal salt, an oxide, or the like or a cover. Further, as the negative electrode active material, oxides and sulfates such as silicon, tin, zinc, manganese, iron, and nickel, lithium alloys such as lithium metal, Li—Al, Li—Bi—Cd, and Li—Sn—Cd, Lithium transition metal nitride, silicone, etc. can be used.
　電極活物質の体積平均粒子径は、正極活物質、負極活物質ともに好ましくは０．０１～１００μｍ、より好ましくは０．０５～５０μｍ、さらに好ましくは０．１～２０μｍである。これらの電極活物質は、それぞれ単独でまたは二種類以上を組み合わせて使用することができる。 The volume average particle diameter of the electrode active material is preferably 0.01 to 100 μm, more preferably 0.05 to 50 μm, and still more preferably 0.1 to 20 μm for both the positive electrode active material and the negative electrode active material. These electrode active materials can be used alone or in combination of two or more.
　（電極用導電材）
　電極用導電材は、導電性を有し、電気二重層を形成し得る細孔を有さない、粒子状の炭素の同素体からなり、具体的には、カーボンブラック、ファーネスブラック、アセチレンブラック、及びケッチェンブラック（アクゾノーベルケミカルズベスローテンフェンノートシャップ社の登録商標）などの導電性カーボンが挙げられる。これらの中でも、アセチレンブラックおよびファーネスブラックが好ましい。 (Conductive material for electrodes)
The conductive material for an electrode is made of an allotrope of particulate carbon that has conductivity and does not have pores that can form an electric double layer. Specifically, carbon black, furnace black, acetylene black, and Examples thereof include conductive carbon such as Ketjen Black (registered trademark of Akzo Nobel Chemicals Beslo Tenfen Note Shap). Among these, acetylene black and furnace black are preferable.
　（電極用バインダー）
　電極用バインダーは、電極活物質、電極用導電材を相互に結着させることができる化合物であれば特に制限はない。好適な電極用バインダーは、溶媒に分散する性質のある分散型バインダーである。分散型バインダーとして、例えば、フッ素重合体、ジエン重合体、アクリレート重合体、ポリイミド、ポリアミド、ポリウレタン重合体等の高分子化合物が挙げられ、フッ素重合体、ジエン重合体又はアクリレート重合体が好ましく、ジエン重合体又はアクリレート重合体が、耐電圧を高くでき、かつリチウムイオン二次電池のエネルギー密度を高くすることができる点でより好ましい。
　ジエン重合体は、共役ジエンの単独重合体もしくは共役ジエンを含む単量体混合物を重合して得られる共重合体、またはそれらの水素添加物である。 (Binder for electrode)
The electrode binder is not particularly limited as long as it is a compound that can bind the electrode active material and the electrode conductive material to each other. A suitable binder for electrodes is a dispersion-type binder having a property of being dispersed in a solvent. Examples of the dispersion-type binder include polymer compounds such as a fluoropolymer, a diene polymer, an acrylate polymer, a polyimide, a polyamide, and a polyurethane polymer, and a fluoropolymer, a diene polymer, or an acrylate polymer is preferable. A polymer or an acrylate polymer is more preferable in that the withstand voltage can be increased and the energy density of the lithium ion secondary battery can be increased.
The diene polymer is a homopolymer of a conjugated diene or a copolymer obtained by polymerizing a monomer mixture containing a conjugated diene, or a hydrogenated product thereof.
　前記単量体混合物における共役ジエンの割合は、好ましくは４０重量％以上、より好ましくは５０重量％以上、さらに好ましくは６０重量％以上である。ジエン重合体の具体例としては、ポリブタジエンやポリイソプレンなどの共役ジエン単独重合体；カルボキシ変性されていてもよいスチレン・ブタジエン共重合体（ＳＢＲ）などの芳香族ビニル・共役ジエン共重合体；アクリロニトリル・ブタジエン共重合体（ＮＢＲ）などのシアン化ビニル・共役ジエン共重合体；水素化ＳＢＲ、水素化ＮＢＲ等が挙げられる。 The ratio of the conjugated diene in the monomer mixture is preferably 40% by weight or more, more preferably 50% by weight or more, and further preferably 60% by weight or more. Specific examples of the diene polymer include conjugated diene homopolymers such as polybutadiene and polyisoprene; aromatic vinyl / conjugated diene copolymers such as carboxy-modified styrene / butadiene copolymer (SBR); acrylonitrile -Vinyl cyanide * conjugated diene copolymers, such as a butadiene copolymer (NBR); Hydrogenated SBR, hydrogenated NBR, etc. are mentioned.
　アクリレート重合体は、一般式（１）：ＣＨ2＝ＣＲ1－ＣＯＯＲ2（式（１）中、Ｒ1は水素原子またはメチル基を、Ｒ2はアルキル基またはシクロアルキル基を表す。）で表される化合物を含む単量体混合物を重合して得られる重合体である。一般式で表される化合物の具体例としては、エチルアクリレート、ｎ－プロピルアクリレート、イソプロピルアクリレート、ｎ－ブチルアクリレート、イソブチルアクリレート、ｔ－ブチルアクリレート、ｎ－アミルアクリレート、イソアミルアクリレート、ヘキシルアクリレート、２－エチルヘキシルアクリレート、ヘキシルアクリレート、ノニルアクリレート、ラウリルアクリレート、ステアリルアクリレートなどのアクリレート；エチルメタクリレート、ｎ－プロピルメタクリレート、イソプロピルメタクリレート、ｎ－ブチルメタクリレート、イソブチルメタクリレート、ｔ－ブチルメタクリレート、ｎ－アミルメタクリレート、イソアミルメタクリレート、ヘキシルメタクリレート、２－エチルヘキシルメタクリレート、オクチルメタクリレート、イソデシルメタクリレート、ラウリルメタクリレート、トリデシルメタクリレート、ステアリルメタクリレートなどのメタアクリレート等が挙げられる。これらの中でも、アクリレートが好ましく、ブチルアクリレートおよび２－エチルヘキシルアクリレートが、得られる電極の強度を向上できる点で、特に好ましい。アクリレート重合体中のアクリル酸エステルおよび／またはメタクリル酸エステル由来の単量体単位の割合は、耐熱性が高く、かつ得られる電気化学素子用電極の内部抵抗を小さくできる観点から、好ましくは５０重量％以上、より好ましくは７０重量％以上である。 The acrylate polymer is represented by the general formula (1): CH 2 = CR 1 —COOR 2 (in the formula (1), R 1 represents a hydrogen atom or a methyl group, and R 2 represents an alkyl group or a cycloalkyl group). It is a polymer obtained by polymerizing a monomer mixture containing the represented compound. Specific examples of the compound represented by the general formula include ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-amyl acrylate, isoamyl acrylate, hexyl acrylate, 2- Acrylates such as ethylhexyl acrylate, hexyl acrylate, nonyl acrylate, lauryl acrylate, stearyl acrylate; ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-amyl methacrylate, isoamyl methacrylate, Hexyl methacrylate, 2-ethylhexyl methacrylate, octyl Methacrylate, isodecyl methacrylate, lauryl methacrylate, tridecyl methacrylate, methacrylate such as stearyl methacrylate, and the like. Among these, acrylate is preferable, and butyl acrylate and 2-ethylhexyl acrylate are particularly preferable in that the strength of the obtained electrode can be improved. The proportion of the monomer unit derived from the acrylate ester and / or methacrylic acid ester in the acrylate polymer is preferably 50% by weight from the viewpoint of high heat resistance and low internal resistance of the obtained electrode for an electrochemical device. % Or more, more preferably 70% by weight or more.
　前記アクリレート重合体は、一般式（１）で表される化合物の他に、共重合可能なカルボン酸基含有単量体を用いることができ、具体例としては、アクリル酸、メタクリル酸などの一塩基酸含有単量体、マレイン酸、フマル酸、イタコン酸などの二塩基酸含有単量体が挙げられる。なかでも、二塩基酸含有単量体が好ましく、導電性接着剤層との結着性を高め、電極強度を向上できる点で、イタコン酸が特に好ましい。これらの一塩基酸含有単量体、二塩基酸含有単量体は、それぞれ単独でまたは２種以上を組み合わせて使用できる。共重合の際の、前記単量体混合物におけるカルボン酸基含有単量体の量は、導電性接着剤層との結着性に優れ、得られる電極強度が高まる観点から、一般式（１）で表される化合物１００重量部に対して、好ましくは０．１～５０重量部、より好ましくは０．５～２０重量部、さらに好ましくは１～１０重量部である。 As the acrylate polymer, a copolymerizable carboxylic acid group-containing monomer can be used in addition to the compound represented by the general formula (1). Specific examples thereof include acrylic acid and methacrylic acid. Examples include basic acid-containing monomers, and dibasic acid-containing monomers such as maleic acid, fumaric acid, and itaconic acid. Among these, a dibasic acid-containing monomer is preferable, and itaconic acid is particularly preferable in terms of improving the binding property with the conductive adhesive layer and improving the electrode strength. These monobasic acid-containing monomers and dibasic acid-containing monomers can be used alone or in combination of two or more. The amount of the carboxylic acid group-containing monomer in the monomer mixture at the time of copolymerization is excellent in binding properties with the conductive adhesive layer, and from the viewpoint of increasing the obtained electrode strength, the general formula (1) The amount is preferably 0.1 to 50 parts by weight, more preferably 0.5 to 20 parts by weight, and still more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the compound represented by formula (1).
　前記アクリレート重合体は、一般式（１）で表される化合物の他に、共重合可能なニトリル基含有単量体を用いることができる。ニトリル基含有単量体の具体例としては、アクリロニトリルやメタクリロニトリルなどが挙げられ、中でもアクリロニトリルが、導電性接着剤層との結着性が高まり、電極強度が向上できる点で好ましい。共重合の際の、前記単量体混合物におけるアクリロニトリルの量は、導電性接着剤層との結着性に優れ、得られる電極強度が高まる観点から、一般式（１）で表される化合物１００重量部に対して、好ましくは０．１～４０重量部、より好ましくは０．５～３０重量部、さらに好ましくは１～２０重量部である。 In addition to the compound represented by the general formula (1), a copolymerizable nitrile group-containing monomer can be used for the acrylate polymer. Specific examples of the nitrile group-containing monomer include acrylonitrile, methacrylonitrile, and the like. Among them, acrylonitrile is preferable in that the binding strength with the conductive adhesive layer is increased and the electrode strength can be improved. In the copolymerization, the amount of acrylonitrile in the monomer mixture is excellent in the binding property with the conductive adhesive layer, and the compound 100 represented by the general formula (1) from the viewpoint of increasing the electrode strength obtained. The amount is preferably 0.1 to 40 parts by weight, more preferably 0.5 to 30 parts by weight, and still more preferably 1 to 20 parts by weight with respect to parts by weight.
　電極用バインダーの形状は、特に制限はないが、導電性接着剤層との結着性が良く、また、作成した電極の容量の低下や充放電の繰り返しによる劣化を抑えることができるため、粒子状であることが好ましい。 The shape of the binder for the electrode is not particularly limited, but it has good binding properties with the conductive adhesive layer, and can suppress deterioration of the capacity of the prepared electrode and deterioration due to repeated charge and discharge. It is preferable that it is a shape.
　電極用バインダーのガラス転移温度（Ｔｇ）は、少量の使用量で結着性に優れ、電極強度が強く、柔軟性に富み、電極形成時のプレスエ程により電極密度を容易に高めることができる観点から、好ましくは５０℃以下、さらに好ましくは－４０～０℃である。 The glass transition temperature (Tg) of the binder for the electrode is excellent in binding property with a small amount of use, strong in the electrode strength, rich in flexibility, and the viewpoint that the electrode density can be easily increased by the press process at the time of electrode formation. Therefore, it is preferably 50 ° C. or lower, more preferably −40 to 0 ° C.
　電極用バインダーが粒子状である場合、その数平均粒子径は、格別な限定はないが、少量の使用でも優れた結着力を電極に与えることができる観点から、好ましくは０．０００１～１００μｍ、より好ましくは０．００１～１０μｍ、さらに好ましくは０．０１～１μｍである。ここで、数平均粒子径は、透過型電子顕微鏡写真で無作為に選んだ電極用バインダー粒子１００個の径を測定し、その算術平均値として算出される個数平均粒子径である。粒子の形状は球形、異形、どちらでもかまわない。これらの電極用バインダーは単独でまたは二種類以上を組み合わせて用いることができる。 When the electrode binder is in the form of particles, the number average particle diameter is not particularly limited. However, from the viewpoint that an excellent binding force can be imparted to the electrode even with a small amount of use, it is preferably 0.0001 to 100 μm, More preferably, it is 0.001 to 10 μm, and still more preferably 0.01 to 1 μm. Here, the number average particle diameter is a number average particle diameter calculated as an arithmetic average value obtained by measuring the diameter of 100 electrode binder particles randomly selected from a transmission electron micrograph. The shape of the particles can be either spherical or irregular. These electrode binders can be used alone or in combination of two or more.
　電極用バインダーの使用量は、得られる電極活物質層と導電性接着剤層との密着性が十分に確保でき、リチウムイオン二次電池の容量を高く且つ内部抵抗を低くすることができる観点から、電極活物質１００重量部に対して、好ましくは０．１～５０重量部、より好ましくは０．５～２０重量部、さらに好ましくは１～１０重量部である。 The amount of the electrode binder used is from the viewpoint that the adhesion between the obtained electrode active material layer and the conductive adhesive layer can be sufficiently secured, the capacity of the lithium ion secondary battery can be increased, and the internal resistance can be decreased. The amount is preferably 0.1 to 50 parts by weight, more preferably 0.5 to 20 parts by weight, and still more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the electrode active material.
　（電極活物質層）
　電極活物質層は、導電性接着剤層上に設けられるが、その形成方法は制限されない。電極活物質層用スラリーは、電極活物質及び電極用バインダーを必須成分として、必要に応じて電極用導電材、その他の分散剤および添加剤を配合することができる。その他の分散剤の具体例としては、カルボキシメチルセルロース、メチルセルロース、エチルセルロースおよびヒドロキシプロピルセルロースなどのセルロース系ポリマー、ならびにこれらのアンモニウム塩またはアルカリ金属塩；ポリ（メタ）アクリル酸ナトリウムなどのポリ（メタ）アクリル酸塩；ポリビニルアルコール、変性ポリビニルアルコール、ポリエチレンオキシド、ポリビニルピロリドン、ポリカルボン酸、酸化スターチ、リン酸スターチ、カゼイン、各種変性デンプンなどが挙げられる。 (Electrode active material layer)
The electrode active material layer is provided on the conductive adhesive layer, but the formation method is not limited. The electrode active material layer slurry may contain an electrode active material and an electrode binder as essential components, and if necessary, an electrode conductive material and other dispersants and additives. Specific examples of other dispersants include cellulosic polymers such as carboxymethylcellulose, methylcellulose, ethylcellulose and hydroxypropylcellulose, and ammonium or alkali metal salts thereof; poly (meth) acrylic such as sodium poly (meth) acrylate. Acid salts; polyvinyl alcohol, modified polyvinyl alcohol, polyethylene oxide, polyvinyl pyrrolidone, polycarboxylic acid, oxidized starch, phosphate starch, casein, various modified starches and the like.
　これらの分散剤は、それぞれ単独でまたは２種以上を組み合わせて使用できる。中でも、セルロース系ポリマーが好ましく、カルボキシメチルセルロースまたはそのアンモニウム塩もしくはアルカリ金属塩が特に好ましい。これらの分散剤の量は、格別な限定はないが、電極活物質１００重量部に対して、好ましくは０．１～１０重量部、より好ましくは０．５～５重量部、さらに好ましくは０．８～２重量部である。 These dispersants can be used alone or in combination of two or more. Among these, a cellulose polymer is preferable, and carboxymethyl cellulose or an ammonium salt or an alkali metal salt thereof is particularly preferable. The amount of these dispersants is not particularly limited, but is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, and still more preferably 0 to 100 parts by weight of the electrode active material. 8 to 2 parts by weight.
　電極活物質層を形成する場合、ペースト状の電極活物質層用スラリーは、電極活物質および電極用バインダーの必須成分、並びに必要に応じて用いられる電極用導電材、分散剤および添加剤を、水またはＮ－メチル－２－ピロリドンやテトラヒドロフランなどの有機溶媒中で混練することにより製造することができる。 When forming the electrode active material layer, the paste slurry for the electrode active material layer contains the essential components of the electrode active material and the electrode binder, and the electrode conductive material, dispersant and additive used as necessary. It can be produced by kneading in water or an organic solvent such as N-methyl-2-pyrrolidone or tetrahydrofuran.
　電極活物質層用スラリーを得るために用いる溶媒は、特に限定されないが、上記の分散剤を用いる場合には、分散剤を溶解可能な溶媒が好適に用いられる。具体的には、通常水が用いられるが、有機溶媒を用いることもできるし、水と有機溶媒との混合溶媒を用いてもよい。有機溶媒としては、例えば、メチルアルコール、エチルアルコール、プロピルアルコール等のアルキルアルコール類；アセトン、メチルエチルケトン等のアルキルケトン類；テトラヒドロフラン、ジオキサン、ジグライム等のエーテル類；ジエチルホルムアミド、ジメチルアセトアミド、Ｎ－メチル－２－ピロリドン、ジメチルイミダゾリジノン等のアミド類；ジメチルスルホキサイド、スルホラン等のイオウ系溶剤；等が挙げられる。この中でも有機溶媒としては、アルコール類が好ましい。電極活物質層用スラリーは、電極活物質層の乾燥の容易さと環境への負荷に優れる点から水を分散媒とした水系スラリーが好ましい。水と、水よりも沸点の低い有機溶媒とを併用すると、乾燥速度を速くすることができる。また、水と併用する有機溶媒の量または種類によって、バインダーの分散性または分散剤の溶解性が変わる。これにより、スラリーの粘度や流動性を調整することができ、生産効率を向上させることができる。 The solvent used for obtaining the electrode active material layer slurry is not particularly limited, but when the above-described dispersant is used, a solvent capable of dissolving the dispersant is preferably used. Specifically, water is usually used, but an organic solvent may be used, or a mixed solvent of water and an organic solvent may be used. Examples of the organic solvent include alkyl alcohols such as methyl alcohol, ethyl alcohol and propyl alcohol; alkyl ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran, dioxane and diglyme; diethylformamide, dimethylacetamide and N-methyl- Amides such as 2-pyrrolidone and dimethylimidazolidinone; sulfur solvents such as dimethyl sulfoxide and sulfolane; and the like. Among these, alcohols are preferable as the organic solvent. The slurry for the electrode active material layer is preferably an aqueous slurry using water as a dispersion medium from the viewpoint of easy drying of the electrode active material layer and excellent environmental load. When water and an organic solvent having a lower boiling point than water are used in combination, the drying rate can be increased. Further, the dispersibility of the binder or the solubility of the dispersant varies depending on the amount or type of the organic solvent used in combination with water. Thereby, the viscosity and fluidity | liquidity of a slurry can be adjusted and production efficiency can be improved.
　スラリーを調製するときに使用する溶媒の量は、各成分を均一に分散させる観点から、スラリーの固形分濃度が、好ましくは１～９０重量％、より好ましくは５～８５重量％、さらに好ましくは１０～８０重量％となる量である。 The amount of the solvent used when preparing the slurry is such that the solid content concentration of the slurry is preferably 1 to 90% by weight, more preferably 5 to 85% by weight, and still more preferably, from the viewpoint of uniformly dispersing each component. The amount is 10 to 80% by weight.
　電極活物質および電極用バインダー、必要に応じて用いられる電極用導電材、その他の分散剤や添加剤を溶媒に分散または溶解する方法または手順は特に限定されず、例えば、溶媒に電極活物質、電極用導電材、電極用バインダーおよびその他の分散剤や添加剤を添加し混合する方法；溶媒に分散剤を溶解した後、溶媒に分散させた電極用バインダーを添加して混合し、最後に電極活物質および電極用導電材等を添加して混合する方法；溶媒に分散させたバインダーに電極活物質および電極用導電材等を添加して混合し、この混合物に溶媒に溶解させた分散剤を添加して混合する方法等が挙げられる。混合の手段としては、例えば、ボールミル、サンドミル、ビーズミル、顔料分散機、らい潰機、超音波分散機、ホモジナイザー、ホモミキサー、プラネタリーミキサー等の混合機器が挙げられる。混合は、好ましくは、室温～８０℃で、１０分～数時間行う。 A method or procedure for dispersing or dissolving the electrode active material and the electrode binder, the electrode conductive material used as necessary, and other dispersants and additives in the solvent is not particularly limited. For example, the electrode active material in the solvent, Method of adding and mixing electrode conductive material, electrode binder and other dispersant or additive; dissolving the dispersant in the solvent, then adding and mixing the electrode binder dispersed in the solvent, and finally the electrode A method of adding and mixing an active material and a conductive material for an electrode; adding and mixing an electrode active material and a conductive material for an electrode to a binder dispersed in a solvent, and dissolving the dispersant dissolved in the solvent into the mixture The method of adding and mixing is mentioned. Examples of the mixing means include mixing equipment such as a ball mill, a sand mill, a bead mill, a pigment disperser, a crusher, an ultrasonic disperser, a homogenizer, a homomixer, and a planetary mixer. The mixing is preferably performed at room temperature to 80 ° C. for 10 minutes to several hours.
　電極活物質層用スラリーの粘度は、室温において、生産性を上げる観点から、好ましくは１０～１００，０００ｍＰａ・ｓ、より好ましくは３０～５０，０００ｍＰａ・ｓ、さらに好ましくは５０～２０，０００ｍＰａ・ｓである。 The viscosity of the electrode active material layer slurry is preferably 10 to 100,000 mPa · s, more preferably 30 to 50,000 mPa · s, and still more preferably 50 to 20,000 mPa · s from the viewpoint of increasing productivity at room temperature. s.
　電極活物質層用スラリーの導電性接着剤層上への塗布方法は特に制限されない。例えば、ドクターブレード法、ディップ法、リバースロール法、ダイレクトロール法、グラビア法、エクストルージョン法、ハケ塗り法などの方法が挙げられる。電極活物質層用スラリーの塗布厚は、目的とする電極活物質層の厚みに応じて適宜に設定される。 The method for applying the electrode active material layer slurry onto the conductive adhesive layer is not particularly limited. Examples thereof include a doctor blade method, a dip method, a reverse roll method, a direct roll method, a gravure method, an extrusion method, and a brush coating method. The coating thickness of the electrode active material layer slurry is appropriately set according to the target thickness of the electrode active material layer.
　乾燥方法としては例えば温風、熱風、低湿風による乾燥、真空乾燥、（遠）赤外線や電子線などの照射による乾燥法が挙げられる。中でも、遠赤外線の照射による乾燥法が好ましい。乾燥温度と乾燥時間は、集電体の導電性接着剤層状に塗布した電極活物質層用スラリー中の溶媒を完全に除去できる温度と時間が好ましく、乾燥温度としては好ましくは１００～３００℃、より好ましくは１２０～２５０℃である。乾燥時間としては、好ましくは１０分～１００時間、より好ましくは２０分～２０時間である。 Examples of the drying method include drying with warm air, hot air, low-humidity air, vacuum drying, and drying by irradiation with (far) infrared rays or electron beams. Among these, a drying method by irradiation with far infrared rays is preferable. The drying temperature and the drying time are preferably a temperature and a time at which the solvent in the slurry for the electrode active material layer applied to the conductive adhesive layer of the current collector can be completely removed. The drying temperature is preferably 100 to 300 ° C., More preferably, the temperature is 120 to 250 ° C. The drying time is preferably 10 minutes to 100 hours, more preferably 20 minutes to 20 hours.
　電極活物質層の密度は、特に制限されないが、好ましくは０．３０～１０ｇ／ｃｍ3、より好ましくは０．３５～８．０ｇ／ｃｍ3、さらに好ましくは０．４０～６．０ｇ／ｃｍ3である。また、電極活物質層の厚みは、特に制限されないが、好ましくは５～１０００μｍ、より好ましくは２０～５００μｍ、さらに好ましくは３０～３００μｍである。 The density of the electrode active material layer is not particularly limited, but is preferably 0.30 to 10 g / cm 3 , more preferably 0.35 to 8.0 g / cm 3 , and still more preferably 0.40 to 6.0 g / cm 3 . 3 . The thickness of the electrode active material layer is not particularly limited, but is preferably 5 to 1000 μm, more preferably 20 to 500 μm, and still more preferably 30 to 300 μm.
　（電気化学素子）
　前記電気化学素子用電極の使用態様としては、かかる電極を用いたリチウムイオン二次電池、電気二重層キャパシタ、リチウムイオンキャパシタ、ナトリウム電池、マグネシウム電池などが挙げられ、リチウムイオン二次電池が好適である。たとえばリチウムイオン二次電池は、上記電気化学素子用電極、セパレーターおよび電解液で構成される。 (Electrochemical element)
Examples of usage of the electrode for an electrochemical element include a lithium ion secondary battery, an electric double layer capacitor, a lithium ion capacitor, a sodium battery, and a magnesium battery using the electrode, and a lithium ion secondary battery is preferable. is there. For example, a lithium ion secondary battery is composed of the electrochemical element electrode, a separator, and an electrolytic solution.
　（セパレーター）
　セパレーターは、電気化学素子用電極の間を絶縁でき、陽イオンおよび陰イオンを通過させることができるものであれば特に限定されない。具体的には、（ａ）気孔部を有する多孔性セパレーター、（ｂ）片面または両面に高分子コート層が形成された多孔性セパレーター、または（ｃ）無機セラミック粉末を含む多孔質の樹脂コート層が形成された多孔性セパレーターが挙げられる。これらの非制限的な例としては、ポリプロピレン系、ポリエチレン系、ポリオレフィン系、またはアラミド系多孔性セパレーター、ポリビニリデンフルオリド、ポリエチレンオキシド、ポリアクリロニトリルまたはポリビニリデンフルオリドヘキサフルオロプロピレン共重合体などの固体高分子電解質用またはゲル状高分子電解質用の高分子フィルム、ゲル化高分子コート層がコートされたセパレーター、または無機フィラー、無機フィラー用分散剤からなる多孔膜層がコートされたセパレーターなどを用いることができる。セパレーターは、上記一対の電極活物質層が対向するように、電気化学素子用電極の間に配置され、素子が得られる。セパレーターの厚みは、使用目的に応じて適宜選択されるが、好ましくは１～１００μｍ、より好ましくは１０～８０μｍ、さらに好ましくは２０～６０μｍである。 (separator)
A separator will not be specifically limited if it can insulate between the electrodes for electrochemical elements, and can allow a cation and an anion to pass through. Specifically, (a) a porous separator having pores, (b) a porous separator having a polymer coating layer formed on one or both sides, or (c) a porous resin coating layer containing inorganic ceramic powder A porous separator in which is formed. Non-limiting examples of these include solids such as polypropylene, polyethylene, polyolefin, or aramid porous separators, polyvinylidene fluoride, polyethylene oxide, polyacrylonitrile, or polyvinylidene fluoride hexafluoropropylene copolymers. Use a polymer film for a polymer electrolyte or gel polymer electrolyte, a separator coated with a gelled polymer coating layer, or a separator coated with a porous membrane layer made of a dispersant for inorganic filler or inorganic filler. be able to. A separator is arrange | positioned between the electrodes for electrochemical elements so that said pair of electrode active material layer may oppose, and an element is obtained. The thickness of the separator is appropriately selected depending on the purpose of use, but is preferably 1 to 100 μm, more preferably 10 to 80 μm, and still more preferably 20 to 60 μm.
　（電解液）
　電解液は、特に限定されないが、例えば、非水系の溶媒に支持電解質としてリチウム塩を溶解したものが使用できる。リチウム塩としては、例えば、ＬｉＰＦ6、ＬｉＡｓＦ6、ＬｉＢＦ4、ＬｉＳｂＦ6、ＬｉＡｌＣｌ4、ＬｉＣｌＯ4、ＣＦ3ＳＯ3Ｌｉ、Ｃ4Ｆ9ＳＯ3Ｌｉ、ＣＦ3ＣＯＯＬｉ、（ＣＦ3ＣＯ）2ＮＬｉ、（ＣＦ3ＳＯ2）2ＮＬｉ、（Ｃ2Ｆ5ＳＯ2）ＮＬｉなどのリチウム塩が挙げられる。特に溶媒に溶けやすく高い解離度を示すＬｉＰＦ6、ＬｉＣｌＯ4、ＣＦ3ＳＯ3Ｌｉは好適に用いられる。これらは、単独、または２種以上を混合して用いることができる。支持電解質の量は、電解液に対して、好ましくは１重量％以上、より好ましくは５重量％以上、また好ましくは３０重量％以下、より好ましくは２０重量％以下である。支持電解質の量が少なすぎても多すぎてもイオン導電度は低下し電池の充電特性、放電特性が低下する。 (Electrolyte)
The electrolytic solution is not particularly limited. For example, a solution obtained by dissolving a lithium salt as a supporting electrolyte in a non-aqueous solvent can be used. Examples of the lithium salt include LiPF 6 , LiAsF 6 , LiBF 4 , LiSbF 6 , LiAlCl 4 , LiClO 4 , CF 3 SO 3 Li, C 4 F 9 SO 3 Li, CF 3 COOLi, (CF 3 CO) 2 NLi , (CF 3 SO 2 ) 2 NLi, (C 2 F 5 SO 2 ) NLi, and other lithium salts. In particular, LiPF 6 , LiClO 4 , and CF 3 SO 3 Li that are easily soluble in a solvent and exhibit a high degree of dissociation are preferably used. These can be used alone or in admixture of two or more. The amount of the supporting electrolyte is preferably 1% by weight or more, more preferably 5% by weight or more, and preferably 30% by weight or less, more preferably 20% by weight or less with respect to the electrolytic solution. If the amount of the supporting electrolyte is too small or too large, the ionic conductivity is lowered, and the charging characteristics and discharging characteristics of the battery are degraded.
　電解液に使用する溶媒としては、支持電解質を溶解させるものであれば特に限定されないが、通常、ジメチルカーボネート（ＤＭＣ）、エチレンカーボネート（ＥＣ）、ジエチルカーボネート（ＤＥＣ）、プロピレンカーボネート（ＰＣ）、ブチレンカーボネート（ＢＣ）、およびメチルエチルカーボネート（ＭＥＣ）などのアルキルカーボネート類；γ－ブチロラクトン、ギ酸メチルなどのエステル類、１，２－ジメトキシエタン、およびテトラヒドロフランなどのエーテル類；スルホラン、およびジメチルスルホキシドなどの含硫黄化合物類；が用いられる。特に高いイオン伝導性が得易く、使用温度範囲が広いため、ジメチルカーボネート、エチレンカーボネート、プロピレンカーボネート、ジエチルカーボネート、メチルエチルカーボネートが好ましい。これらは、単独、または２種以上を混合して用いることができる。また、電解液には添加剤を含有させて用いることも可能である。また、添加剤としてはビニレンカーボネート（ＶＣ）などのカーボネート系の化合物が好ましい。 The solvent used in the electrolytic solution is not particularly limited as long as it can dissolve the supporting electrolyte. Usually, dimethyl carbonate (DMC), ethylene carbonate (EC), diethyl carbonate (DEC), propylene carbonate (PC), butylene. Alkyl carbonates such as carbonate (BC) and methyl ethyl carbonate (MEC); esters such as γ-butyrolactone and methyl formate; ethers such as 1,2-dimethoxyethane; tetrahydrofuran; sulfolane and dimethyl sulfoxide Sulfur-containing compounds are used. In particular, dimethyl carbonate, ethylene carbonate, propylene carbonate, diethyl carbonate, and methyl ethyl carbonate are preferable because high ion conductivity is easily obtained and the use temperature range is wide. These can be used alone or in admixture of two or more. Moreover, it is also possible to use an electrolyte containing an additive. The additive is preferably a carbonate compound such as vinylene carbonate (VC).
　上記以外の電解液としては、ポリエチレンオキシド、ポリアクリロニトリルなどのポリマー電解質に電解液を含浸したゲル状ポリマー電解質や、硫化リチウム、ＬｉＩ、Ｌｉ3Ｎなどの無機固体電解質を挙げることができる。 Examples of the electrolytic solution other than the above include a gel polymer electrolyte obtained by impregnating a polymer electrolyte such as polyethylene oxide and polyacrylonitrile with an electrolytic solution, and an inorganic solid electrolyte such as lithium sulfide, LiI, and Li 3 N.
　リチウムイオン二次電池は、負極と正極とをセパレーター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入れ、電池容器に電解液を注入して封口して得られる。さらに必要に応じてエキスパンドメタルや、ヒューズ、ＰＴＣ素子などの過電流防止素子、リード板などを入れ、電池内部の圧力上昇、過充放電の防止をすることもできる。電池の形状は、ラミネートセル型、コイン型、ボタン型、シート型、円筒型、角形、扁平型などいずれであってもよい。 A lithium ion secondary battery is obtained by stacking a negative electrode and a positive electrode through a separator, winding this according to the shape of the battery, folding it into a battery container, pouring the electrolyte into the battery container and sealing it. It is done. Further, if necessary, an expanded metal, an overcurrent prevention element such as a fuse or a PTC element, a lead plate and the like can be inserted to prevent an increase in pressure inside the battery and overcharge / discharge. The shape of the battery may be any of a laminated cell type, a coin type, a button type, a sheet type, a cylindrical type, a square type, a flat type, and the like.
　以下、実施例および比較例により本発明をさらに具体的に説明するが、これらの実施例に限定されるものではない。なお、実施例および比較例における部および％は、特に断りのない限り重量基準である。実施例および比較例における各特性は、下記の方法に従い測定した。 Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but is not limited to these Examples. In the examples and comparative examples, “part” and “%” are based on weight unless otherwise specified. Each characteristic in an Example and a comparative example was measured in accordance with the following method.
　（高温サイクル特性）
　実施例および比較例で製造したラミネート型セルのリチウムイオン二次電池を２４時間静置させた後に、４．２５Ｖ、０．１Ｃの充放電レートにて充放電の操作を行い、初期容量Ｃ0を測定した。さらに、６０℃の環境下で充放電を繰り返し、１００サイクル後の容量Ｃ2を測定した。高温サイクル特性は、ΔＣC＝Ｃ2／Ｃ0×１００（％）で示す充放電容量保持率ΔＣCを、下記基準により評価した。結果を表１に示す。この充放電容量保持率ΔＣCの値が高いほど、高温サイクル特性に優れることを示す。
Ａ：充放電容量保持率が８０％以上
Ｂ：充放電容量保持率が７５％以上８０％未満
Ｃ：充放電容量保持率が７０％以上７５％未満
Ｄ：充放電容量保持率が７０％未満 (High temperature cycle characteristics)
The lithium ion secondary batteries of the laminate type cells produced in the examples and comparative examples were allowed to stand for 24 hours, and then charge / discharge operation was performed at a charge / discharge rate of 4.25 V and 0.1 C to obtain an initial capacity C 0. Was measured. Furthermore, charge / discharge was repeated under an environment of 60 ° C., and the capacity C 2 after 100 cycles was measured. For the high-temperature cycle characteristics, the charge / discharge capacity retention ratio ΔC C represented by ΔC C = C 2 / C 0 × 100 (%) was evaluated according to the following criteria. The results are shown in Table 1. It shows that it is excellent in high temperature cycling characteristics, so that the value of this charge / discharge capacity retention ratio (DELTA) CC is high.
A: Charge / discharge capacity retention is 80% or more B: Charge / discharge capacity retention is 75% or more and less than 80% C: Charge / discharge capacity retention is 70% or more and less than 75% D: Charge / discharge capacity retention is less than 70%
　（低温出力特性）
　実施例および比較例で製造したラミネート型セルのリチウムイオン二次電池を２５℃の環境下で２４時間静置させた後に、２５℃の環境下で、４．２５Ｖ、０．１Ｃ、５時間の充電の操作を行い、その時の電圧Ｖ0を測定した。その後、－１０℃環境下で、１Ｃの放電レートにて放電の操作を行い、放電開始１５秒後の電圧Ｖ1を測定した。低温出力特性は、ΔＶ＝Ｖ0－Ｖ1で示す電圧降下を下記基準に評価し、結果を表１に示した。この値が小さいほど低温出力特性に優れることを示す。
Ａ：電圧降下ΔＶが１００ｍＶ以上１２０ｍＶ未満
Ｂ：電圧降下ΔＶが１２０ｍＶ以上１４０ｍＶ未満
Ｃ：電圧降下ΔＶが１４０ｍＶ以上１６０ｍＶ未満
Ｄ：電圧降下ΔＶが１６０ｍＶ以上１８０ｍＶ未満
Ｅ：電圧降下ΔＶが１８０ｍＶ以上２００ｍＶ未満
Ｆ：電圧降下ΔＶが２００ｍＶ以上 (Low temperature output characteristics)
The lithium ion secondary batteries of the laminate type cells produced in the examples and comparative examples were allowed to stand for 24 hours in an environment at 25 ° C., and then 4.25 V, 0.1 C, 5 hours in an environment at 25 ° C. The charging operation was performed, and the voltage V 0 at that time was measured. Thereafter, a discharge operation was performed at a discharge rate of 1 C in an environment of −10 ° C., and the voltage V 1 15 seconds after the start of discharge was measured. The low-temperature output characteristics were evaluated based on the following voltage drop indicated by ΔV = V 0 −V 1 , and the results are shown in Table 1. It shows that it is excellent in low temperature output characteristics, so that this value is small.
A: Voltage drop ΔV is 100 mV to less than 120 mV B: Voltage drop ΔV is 120 mV to less than 140 mV C: Voltage drop ΔV is 140 mV to less than 160 mV D: Voltage drop ΔV is 160 mV to less than 180 mV E: Voltage drop ΔV is 180 mV to less than 200 mV F: Voltage drop ΔV is 200 mV or more
　また、実施例及び比較例において粒子状結着剤の体積平均粒子径として、レーザー回折式粒度分布測定装置（ＬＳ　１３　３２０　ベックマンコールター社製）により測定した平均粒子径の体積分布から求めた、Ｄ５０の値を用いた。 In addition, as the volume average particle diameter of the particulate binder in Examples and Comparative Examples, D50 was obtained from the volume distribution of the average particle diameter measured with a laser diffraction particle size distribution measuring device (LS 13, 320, manufactured by Beckman Coulter, Inc.). The value of was used.
　（実施例１）
　（粒子状結着剤の製造）
　窒素雰囲気下（窒素気流下）において、攪拌機、温度計、冷却管を装着した反応容器に、イオン交換水、ドデシルベンゼンスルホン酸ナトリウムを加え、６０℃まで加熱し、保温した。６０℃に達した所で、重合開始剤として過硫酸アンモニウムを加え、Ｎ－メチロール基を有するアクリルアミド単量体（Ｎ－メチロールアクリルアミド）４０部、メタクリル酸リチウム３０部及びビニルアルコール３０部を、昇温しながら２時間かけて滴下した。 Example 1
(Manufacture of particulate binder)
In a nitrogen atmosphere (under a nitrogen stream), ion-exchanged water and sodium dodecylbenzenesulfonate were added to a reaction vessel equipped with a stirrer, a thermometer, and a cooling tube, heated to 60 ° C., and kept warm. When the temperature reached 60 ° C., ammonium persulfate was added as a polymerization initiator, and 40 parts of an acrylamide monomer having an N-methylol group (N-methylolacrylamide), 30 parts of lithium methacrylate and 30 parts of vinyl alcohol were heated. The solution was added dropwise over 2 hours.
　滴下後７０℃で５時間激しく攪拌し、同温度で保温した。単量体の重合転化率は９５％であった。室温（２５℃）に冷却後、反応液をろ別した。粒子状結着剤が、水及びドデシルベンゼンスルホン酸ナトリウムに分散したエマルションを得た。また、この粒子状結着剤の粒子径を測定したところ、１３０ｎｍであった。 After dripping, the mixture was vigorously stirred at 70 ° C. for 5 hours and kept at the same temperature. The polymerization conversion rate of the monomer was 95%. After cooling to room temperature (25 ° C.), the reaction solution was filtered off. An emulsion in which the particulate binder was dispersed in water and sodium dodecylbenzenesulfonate was obtained. Further, the particle diameter of the particulate binder was measured and found to be 130 nm.
　（接着剤組成物の製造）
　イオン交換水にノニオン系界面活性剤０．３部を溶かした水溶液へ、導電性カーボンＡ（グラファイト／アセチレンブラック＝５０／５０、平均粒子径２μｍ）を１８．５部及び導電性カーボンＢ（グラフェン）を１．２部添加し、ディスパーを使用して１５００ｒｐｍで１５分間撹拌した後、粒子状結着剤を固形分相当で７部添加して、さらにディスパーにて１５００ｒｐｍで１５分間撹拌した。さらにイオン交換水の量が７３部となるようにイオン交換水を加え、接着剤組成物を作製した。 (Manufacture of adhesive composition)
18.5 parts of conductive carbon A (graphite / acetylene black = 50/50, average particle diameter 2 μm) and conductive carbon B (graphene) were added to an aqueous solution in which 0.3 part of a nonionic surfactant was dissolved in ion-exchanged water. 1.2 parts) was added and stirred at 1500 rpm for 15 minutes using a disper, and then 7 parts of a particulate binder was added corresponding to the solid content, and further stirred at 1500 rpm for 15 minutes with a disper. Furthermore, ion-exchange water was added so that the quantity of ion-exchange water might be 73 parts, and the adhesive composition was produced.
（導電性接着剤層の形成）
　アルミニウムからなる集電体用基材に前記導電性接着剤を、キャスト法を用いてロールバーにて２０ｍ／分の成形速度で集電体用基材上に塗布し、６０℃で１分間、引き続き１２０℃で２分間乾燥して、厚さ１μｍの導電性接着剤層を形成した。これにより集電体用基材上に導電性接着剤層が形成された集電体を得た。 (Formation of conductive adhesive layer)
The conductive adhesive is applied to a current collector base material made of aluminum on a current collector base material at a molding speed of 20 m / min with a roll bar using a cast method, and at 60 ° C. for 1 minute. Subsequently, the film was dried at 120 ° C. for 2 minutes to form a 1 μm thick conductive adhesive layer. As a result, a current collector in which a conductive adhesive layer was formed on the current collector substrate was obtained.
　（電極の作製）
　プラネタリーミキサーにコバルト酸リチウム１００部、アセチレンブラック２部（電気化学工業社製、ＨＳ－１００）、ポリフッ化ビニリデン（ＰＶＤＦ）２部（クレハ社製、ＫＦ－１１００）、さらに全固形分濃度が６７％となるようにＮ－メチル－２－ピロリドンを加えて混合し、正極用の電極活物質層用スラリーを調製した。 (Production of electrodes)
Planetary mixer with 100 parts of lithium cobaltate, 2 parts of acetylene black (manufactured by Denki Kagaku Kogyo Co., Ltd., HS-100), 2 parts of polyvinylidene fluoride (PVDF) (manufactured by Kureha Co., Ltd., KF-1100), and total solids concentration N-methyl-2-pyrrolidone was added and mixed so as to be 67% to prepare a slurry for an electrode active material layer for a positive electrode.
　前記にて導電性接着剤層を形成したアルミニウム集電体に前記正極用の電極活物質層用スラリーを２０ｍ／分の成形速度で集電体の導電性接着剤層上に塗布し、１２０℃で５分間乾燥した後、５ｃｍ正方に打ち抜いて、厚さ１００μｍの電極活物質層を有するリチウムイオン二次電池用の正極を得た。 The electrode active material layer slurry for the positive electrode was applied onto the conductive adhesive layer of the current collector at a molding speed of 20 m / min on the aluminum current collector on which the conductive adhesive layer was formed, and 120 ° C. After being dried for 5 minutes, a 5 cm square was punched out to obtain a positive electrode for a lithium ion secondary battery having an electrode active material layer having a thickness of 100 μm.
　一方負極の活物質として、体積平均粒子径が３．７μｍであるグラファイト（ＫＳ－６：ティムカル社製）を１００部、分散剤としてカルボキシメチルセルロースアンモニウムの１．５％水溶液（ＤＮ－８００Ｈ：ダイセル化学工業社製）を固形分相当で２．０部、電極用導電材としてアセチレンブラック（デンカブラック粉状：電気化学工業社製）を５部、電極用バインダーとしてガラス転移温度が－４８℃で、数平均粒子径が０．１８μｍのジエン重合体の４０％水分散体を固形分相当で３．０部、およびイオン交換水を全固形分濃度が３５％となるように混合し、負極用の電極活物質層用スラリーを調製した。 On the other hand, graphite (KS-6: manufactured by Timcal) having a volume average particle diameter of 3.7 μm is used as an active material for the negative electrode, and 1.5% aqueous solution of carboxymethyl cellulose ammonium as a dispersant (DN-800H: Daicel Chemical). Kogyo Co., Ltd.) 2.0 parts in terms of solid content, 5 parts of acetylene black (denka black powder: manufactured by Denki Kagaku Kogyo Co., Ltd.) as the electrode conductive material, and a glass transition temperature of −48 ° C. as the electrode binder A 40% aqueous dispersion of a diene polymer having a number average particle size of 0.18 μm is mixed to a solid content equivalent of 3.0 parts, and ion-exchanged water is mixed so that the total solid content concentration is 35%. A slurry for the electrode active material layer was prepared.
　コンマコーターを用いて、上記負極用の電極活物質層用スラリーを厚さ１８μｍの銅箔の片面に乾燥後の膜厚が１００μｍ程度になるように塗布した。そして、６０℃で２０分乾燥後、１５０℃で２０分間加熱処理して負極活物質層を形成した。次いで、ロールプレスで圧延して５．２ｃｍ正方に打ち抜いて、片面厚さ５０μｍのリチウムイオン二次電池用の負極を得た。 Using a comma coater, the negative electrode active material layer slurry was applied to one side of a 18 μm thick copper foil so that the film thickness after drying was about 100 μm. And it dried at 60 degreeC for 20 minutes, Then, it heat-processed at 150 degreeC for 20 minutes, and formed the negative electrode active material layer. Subsequently, it was rolled with a roll press and punched into a 5.2 cm square to obtain a negative electrode for a lithium ion secondary battery having a single-sided thickness of 50 μm.
　（リチウムイオン二次電池の製造）
　前記正極、負極及びセパレーターを用いて、積層型ラミネートセル形状のリチウムイオン二次電池を作製した。電解液としてはエチレンカーボネート、ジエチルカーボネートを体積比で１：２とした混合溶媒にＬｉＰＦ6を１．０ｍｏｌ／リットルの濃度で溶解させたものを用いた。得られたリチウムイオン二次電池について高温サイクル特性及び低温出力特性の評価を行った。 (Manufacture of lithium ion secondary batteries)
Using the positive electrode, negative electrode, and separator, a laminated laminate cell-shaped lithium ion secondary battery was produced. As an electrolytic solution, a solution obtained by dissolving LiPF 6 at a concentration of 1.0 mol / liter in a mixed solvent of ethylene carbonate and diethyl carbonate in a volume ratio of 1: 2 was used. The obtained lithium ion secondary battery was evaluated for high temperature cycle characteristics and low temperature output characteristics.
　（実施例２）
　粒子状結着剤の製造において、ビニルアルコールに代えて、スチレンを用いた以外は実施例１と同様に粒子状結着剤の製造を行った。単量体の重合転化率は９５％であった。また、実施例２において得られた粒子状結着剤を用いた以外は、実施例１と同様に接着剤組成物の製造、導電性接着剤層の形成、電極の作製及びリチウムイオン二次電池の製造を行った。 (Example 2)
In the production of the particulate binder, a particulate binder was produced in the same manner as in Example 1 except that styrene was used instead of vinyl alcohol. The polymerization conversion rate of the monomer was 95%. Moreover, except having used the particulate-form binder obtained in Example 2, manufacture of an adhesive composition, formation of an electroconductive adhesive layer, preparation of an electrode, and a lithium ion secondary battery similarly to Example 1 Was manufactured.
　（実施例３）
　粒子状結着剤の製造において、ビニルアルコールに代えて、アクリロニトリルを用い、粒子状結着剤の製造における単量体の仕込み組成をＮ－メチロールアクリルアミド３３部、メタクリル酸リチウム１７部及びアクリロニトリル５０部とした以外は実施例１と同様に粒子状結着剤の製造を行った。単量体の重合転化率は９５％であった。また、実施例３において得られた粒子状結着剤を用いた以外は、実施例１と同様に接着剤組成物の製造、導電性接着剤層の形成、電極の作製及びリチウムイオン二次電池の製造を行った。 Example 3
In the production of the particulate binder, acrylonitrile was used instead of vinyl alcohol, and the monomer charge composition in the production of the particulate binder was 33 parts N-methylolacrylamide, 17 parts lithium methacrylate and 50 parts acrylonitrile. A particulate binder was produced in the same manner as in Example 1 except that. The polymerization conversion rate of the monomer was 95%. Moreover, except having used the particulate-form binder obtained in Example 3, manufacture of an adhesive composition, formation of an electroconductive adhesive layer, preparation of an electrode, and a lithium ion secondary battery similarly to Example 1 Was manufactured.
　（実施例４）
　粒子状結着剤の製造において、Ｎ－メチロール基を有するアクリルアミド単量体（Ｎ－メチロールアクリルアミド）に代えて、第一級アミンのアクリルアミド単量体を用い、さらにメタクリル酸リチウムに代えてメタクリル酸ナトリウムを用いた以外は実施例１と同様に粒子状結着剤の製造を行った。単量体の重合転化率は９５％であった。また、実施例４において得られた粒子状結着剤を用いた以外は、実施例１と同様に接着剤組成物の製造、導電性接着剤層の形成、電極の作製及びリチウムイオン二次電池の製造を行った。 Example 4
In the production of the particulate binder, an acrylamide monomer of a primary amine is used instead of an acrylamide monomer having an N-methylol group (N-methylol acrylamide), and methacrylic acid is used instead of lithium methacrylate. A particulate binder was produced in the same manner as in Example 1 except that sodium was used. The polymerization conversion rate of the monomer was 95%. Moreover, except having used the particulate-form binder obtained in Example 4, manufacture of an adhesive composition, formation of an electroconductive adhesive layer, preparation of an electrode, and a lithium ion secondary battery similarly to Example 1 Was manufactured.
　（実施例５）
　粒子状結着剤の製造において、Ｎ－メチロール基を有するアクリルアミド単量体（Ｎ－メチロールアクリルアミド）に代えて、第一級アミンのアクリルアミド単量体を用いた以外は実施例１と同様に粒子状結着剤の製造を行った。単量体の重合転化率は９５％であった。 (Example 5)
Particles were produced in the same manner as in Example 1 except that a primary amine acrylamide monomer was used instead of the acrylamide monomer having an N-methylol group (N-methylol acrylamide) in the production of the particulate binder. The binder was produced. The polymerization conversion rate of the monomer was 95%.
　また、実施例５において得られた粒子状結着剤を用い、さらにグラフェンに代えてカーボンナノチューブ（以下、「ＣＮＴ」ということがある。）を用いた以外は、実施例１と同様に接着剤組成物の製造を行った。 The adhesive was the same as in Example 1 except that the particulate binder obtained in Example 5 was used and carbon nanotubes (hereinafter sometimes referred to as “CNT”) were used instead of graphene. The composition was manufactured.
　また、実施例５において得られた接着剤組成物を用いた以外は、実施例１と同様に導電性接着剤層の形成、電極の作製及びリチウムイオン二次電池の製造を行った。 Further, except for using the adhesive composition obtained in Example 5, a conductive adhesive layer was formed, an electrode was produced, and a lithium ion secondary battery was produced in the same manner as in Example 1.
　（実施例６）
　粒子状結着剤の製造における単量体の仕込み組成をＮ－メチロールアクリルアミド５０部、メタクリル酸リチウム３０部、及びビニルアルコール２０部とした以外は実施例１と同様に粒子状結着剤の製造を行った。単量体の重合転化率は９５％であった。また、実施例６において得られた粒子状結着剤を用いた以外は、実施例１と同様に接着剤組成物の製造、導電性接着剤層の形成、電極の作製及びリチウムイオン二次電池の製造を行った。 (Example 6)
Production of particulate binder in the same manner as in Example 1, except that the monomer charge composition in the production of particulate binder was changed to 50 parts N-methylolacrylamide, 30 parts lithium methacrylate, and 20 parts vinyl alcohol. Went. The polymerization conversion rate of the monomer was 95%. Moreover, except having used the particulate-form binder obtained in Example 6, manufacture of an adhesive composition, formation of an electroconductive adhesive layer, preparation of an electrode, and a lithium ion secondary battery similarly to Example 1. Was manufactured.
　（実施例７）
　粒子状結着剤の製造における単量体の仕込み組成をＮ－メチロールアクリルアミド２０部、メタクリル酸リチウム４０部、及びビニルアルコール４０部とした以外は実施例１と同様に粒子状結着剤の製造を行った。単量体の重合転化率は９５％であった。また、実施例７において得られた粒子状結着剤を用いた以外は、実施例１と同様に接着剤組成物の製造、導電性接着剤層の形成、電極の作製及びリチウムイオン二次電池の製造を行った。 (Example 7)
Production of particulate binder in the same manner as in Example 1, except that the monomer charge composition in the production of particulate binder was 20 parts N-methylolacrylamide, 40 parts lithium methacrylate, and 40 parts vinyl alcohol. Went. The polymerization conversion rate of the monomer was 95%. Moreover, except having used the particulate-form binder obtained in Example 7, manufacture of an adhesive composition, formation of an electroconductive adhesive layer, preparation of an electrode, and a lithium ion secondary battery similarly to Example 1 Was manufactured.
　（比較例１）
　粒子状結着剤の製造において、メタクリル酸リチウムを用いず、粒子状結着剤の製造における単量体の仕込み組成をＮ－メチロール基を有するアクリルアミド単量体（Ｎ－メチロールアクリルアミド）７０部及びビニルアルコール３０部とした以外は実施例１と同様に粒子状結着剤の製造を行った。単量体の重合転化率は９５％であった。また、比較例１において得られた粒子状結着剤を用いた以外は、実施例１と同様に接着剤組成物の製造、導電性接着剤層の形成、電極の作製及びリチウムイオン二次電池の製造を行った。 (Comparative Example 1)
In the production of the particulate binder, lithium methacrylate was not used, and the charge composition of the monomer in the production of the particulate binder was 70 parts of an acrylamide monomer having an N-methylol group (N-methylolacrylamide) and A particulate binder was produced in the same manner as in Example 1 except that 30 parts of vinyl alcohol was used. The polymerization conversion rate of the monomer was 95%. Moreover, manufacture of an adhesive composition, formation of a conductive adhesive layer, preparation of an electrode, and a lithium ion secondary battery were performed in the same manner as in Example 1 except that the particulate binder obtained in Comparative Example 1 was used. Was manufactured.
　（比較例２）
　粒子状結着剤の製造において、Ｎ－メチロールアクリルアミドを用いず、粒子状結着剤の製造における単量体の仕込み組成をメタクリル酸リチウム７０部及びビニルアルコール３０部とした以外は実施例１と同様に粒子状結着剤の製造を行った。単量体の重合転化率は９５％であった。また、比較例２において得られた粒子状結着剤を用いた以外は、実施例１と同様に接着剤組成物の製造、導電性接着剤層の形成、電極の作製及びリチウムイオン二次電池の製造を行った。 (Comparative Example 2)
Example 1 except that N-methylolacrylamide was not used in the production of the particulate binder, and the monomer charge composition in the production of the particulate binder was changed to 70 parts lithium methacrylate and 30 parts vinyl alcohol. Similarly, a particulate binder was produced. The polymerization conversion rate of the monomer was 95%. Moreover, manufacture of an adhesive composition, formation of a conductive adhesive layer, preparation of an electrode, and a lithium ion secondary battery were performed in the same manner as in Example 1 except that the particulate binder obtained in Comparative Example 2 was used. Was manufactured.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１に示すように、導電性カーボン、粒子状結着剤、及び水を含み、前記粒子状結着剤が（メタ）アクリルアミド単量体及び（メタ）アクリル酸塩単量体に由来する構成単位を含む重合体である接着剤組成物を用いて形成された導電性接着剤層を有するリチウムイオン二次電池の高温サイクル特性及び低温出力特性は良好であった。 As shown in Table 1, the composition contains conductive carbon, a particulate binder, and water, and the particulate binder is derived from a (meth) acrylamide monomer and a (meth) acrylate monomer. The lithium ion secondary battery having a conductive adhesive layer formed using an adhesive composition that is a polymer containing units had good high-temperature cycle characteristics and low-temperature output characteristics.

Claims (9)

  1. 　導電性カーボン、粒子状結着剤、及び水を含み、
    　前記粒子状結着剤が（メタ）アクリルアミド単量体及び（メタ）アクリル酸塩単量体に由来する構成単位を含む重合体であることを特徴とする電気化学素子電極用導電性接着剤組成物。     Including conductive carbon, particulate binder, and water,
    The conductive binder composition for an electrochemical element electrode, wherein the particulate binder is a polymer containing a structural unit derived from a (meth) acrylamide monomer and a (meth) acrylate monomer object.
  2. 　前記粒子状結着剤が、（メタ）アクリルアミド単量体５～７０重量部及び（メタ）アクリル酸塩単量体１～５０重量部を含む単量体混合物（但し、単量体成分の合計を１００重量部とする）を重合して得られるものである請求項１に記載の電気化学素子電極用導電性接着剤組成物。 The particulate binder comprises a monomer mixture containing 5 to 70 parts by weight of a (meth) acrylamide monomer and 1 to 50 parts by weight of a (meth) acrylate monomer (provided that the total amount of monomer components) The conductive adhesive composition for electrochemical device electrodes according to claim 1, wherein the conductive adhesive composition is obtained by polymerization.
  3. 　前記（メタ）アクリル酸塩単量体が、（メタ）アクリル酸リチウム、または／および、（メタ）アクリル酸ナトリウムである請求項１または請求項２に記載の電気化学素子電極用導電性接着剤組成物。 The conductive adhesive for an electrochemical element electrode according to claim 1, wherein the (meth) acrylate monomer is lithium (meth) acrylate and / or sodium (meth) acrylate. Composition.
  4. 　前記粒子状結着剤が、ビニルアルコール、スチレンまたは（メタ）アクリロニトリルのいずれか１種類以上を含む単量体成分をさらに１０～５０重量部含む単量体混合物（但し、単量体成分の合計を１００重量部とする）を重合して得られるものである請求項１～３のいずれかに記載の電気化学素子電極用導電性接着剤組成物。 The particulate binder further comprises a monomer mixture containing 10 to 50 parts by weight of a monomer component containing at least one of vinyl alcohol, styrene and (meth) acrylonitrile (however, the total of the monomer components) The conductive adhesive composition for electrochemical device electrodes according to any one of claims 1 to 3, wherein the conductive adhesive composition is obtained by polymerizing (100 parts by weight).
  5. 　前記粒子状結着剤の体積平均粒子径が５～５００ｎｍであることを特徴とする請求項１～４のいずれかに記載の電気化学素子電極用導電性接着剤組成物。 5. The conductive adhesive composition for an electrochemical element electrode according to claim 1, wherein the volume average particle diameter of the particulate binder is 5 to 500 nm.
  6. 　前記導電性カーボンの含有割合が８～３８重量％、前記粒子状結着剤の含有割合が０．５～１０重量％、前記水の含有割合が６０～９０重量％であることを特徴とする請求項１～５のいずれかに記載の電気化学素子電極用導電性接着剤組成物。 The conductive carbon content is 8 to 38% by weight, the particulate binder content is 0.5 to 10% by weight, and the water content is 60 to 90% by weight. The conductive adhesive composition for electrochemical element electrodes according to any one of claims 1 to 5.
  7.  さらに非イオン性界面活性剤を０．０５～１重量％含むことを特徴とする請求項１～６のいずれかに記載の電気化学素子電極用導電性接着剤組成物。 The conductive adhesive composition for electrochemical device electrodes according to any one of claims 1 to 6, further comprising 0.05 to 1% by weight of a nonionic surfactant.
  8. 　前記導電性カーボンがグラフェン、カーボンナノチューブを更に含むことを特徴とする請求項１～７のいずれかに記載の電気化学素子電極用導電性接着剤組成物。 The conductive adhesive composition for an electrochemical element electrode according to any one of claims 1 to 7, wherein the conductive carbon further contains graphene and carbon nanotubes.
  9. 　請求項１～８のいずれかに記載の電気化学素子電極用導電性接着剤組成物を塗布・乾燥してなる電気化学素子電極用集電体。 A current collector for an electrochemical element electrode obtained by applying and drying the conductive adhesive composition for an electrochemical element electrode according to any one of claims 1 to 8.
PCT/JP2015/058279 2014-03-28 2015-03-19 Conductive adhesive composition for electrochemical element electrodes and collector for electrochemical element electrodes WO2015146787A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2016510285A JP6519581B2 (en) 2014-03-28 2015-03-19 Conductive adhesive composition for electrochemical element electrode and current collector for electrochemical element electrode

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2014-067478 2014-03-28
JP2014067478 2014-03-28

Publications (1)

Publication Number Publication Date
WO2015146787A1 true WO2015146787A1 (en) 2015-10-01

Family

ID=54195308

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2015/058279 WO2015146787A1 (en) 2014-03-28 2015-03-19 Conductive adhesive composition for electrochemical element electrodes and collector for electrochemical element electrodes

Country Status (2)

Country Link
JP (1) JP6519581B2 (en)
WO (1) WO2015146787A1 (en)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108155386A (en) * 2018-01-24 2018-06-12 广州鹏辉能源科技股份有限公司 Anode material for lithium-ion batteries, based lithium-ion battery positive plate and preparation method thereof and lithium ion battery
CN108172837A (en) * 2018-01-24 2018-06-15 广州鹏辉能源科技股份有限公司 Lithium ion battery negative material, anode plate for lithium ionic cell and preparation method thereof and lithium ion battery
US20180351177A1 (en) * 2015-12-24 2018-12-06 Lg Chem, Ltd. Binder composition for secondary battery, and electrode for secondary battery and lithium secondary battery comprising the same
KR20190064012A (en) * 2017-11-30 2019-06-10 주식회사 엘지화학 Binder comprising random copolymer, anode for lithium-ion secondary battery comprising the same, lithium-ion secondary battery comprising the anode, and method for polymerizing the copolymer
JP2019216035A (en) * 2018-06-13 2019-12-19 三洋化成工業株式会社 Resin collector, lamination type resin collector, and lithium ion battery
CN111886719A (en) * 2018-03-29 2020-11-03 日产化学株式会社 Composition for forming undercoat layer of energy storage device
JP2021039861A (en) * 2019-09-02 2021-03-11 Jsr株式会社 Composition for power storage device, slurry for power storage device electrode, power storage device electrode, and power storage device
WO2021108987A1 (en) * 2019-12-03 2021-06-10 宁德时代新能源科技股份有限公司 Composite graphite material, secondary battery, device, and preparation method
WO2021108990A1 (en) * 2019-12-03 2021-06-10 宁德时代新能源科技股份有限公司 Secondary battery and preparation method therefor, and copolymer and device
CN113169302A (en) * 2019-03-28 2021-07-23 日本瑞翁株式会社 Conductive material paste for lithium ion secondary battery electrode, slurry composition for lithium ion secondary battery electrode, electrode for lithium ion secondary battery, and lithium ion secondary battery
WO2021253616A1 (en) * 2020-06-17 2021-12-23 Guangdong Haozhi Technology Co. Limited Binder composition for secondary battery
WO2024062881A1 (en) * 2022-09-22 2024-03-28 株式会社豊田自動織機 Electrode for power storage device, and method for producing composite material for active material layer
CN113207315B (en) * 2019-12-03 2024-05-10 宁德时代新能源科技股份有限公司 Composite graphite material, secondary battery, device and preparation method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58225563A (en) * 1982-06-23 1983-12-27 Fuji Elelctrochem Co Ltd Production method of nonaqueous electrolyte cell
JP2012124133A (en) * 2010-12-10 2012-06-28 Furukawa Sky Kk Collector, electrode structure, nonaqueous electrolyte battery and power storage component
WO2012133030A1 (en) * 2011-03-31 2012-10-04 東洋インキＳｃホールディングス株式会社 Aqueous composition for forming secondary battery electrode, secondary battery electrode, and secondary battery
JP2013023654A (en) * 2011-07-25 2013-02-04 Showa Denko Kk Binder for carbon coat foil coating solution, carbon coat foil coating solution, carbon coat foil, electrode for lithium ion secondary battery, and lithium ion secondary battery

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015106488A (en) * 2013-11-29 2015-06-08 Jsr株式会社 Slurry for electricity storage device negative electrode and electricity storage device negative electrode, slurry for electricity storage device positive electrode and electricity storage device positive electrode, and electricity storage device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58225563A (en) * 1982-06-23 1983-12-27 Fuji Elelctrochem Co Ltd Production method of nonaqueous electrolyte cell
JP2012124133A (en) * 2010-12-10 2012-06-28 Furukawa Sky Kk Collector, electrode structure, nonaqueous electrolyte battery and power storage component
WO2012133030A1 (en) * 2011-03-31 2012-10-04 東洋インキＳｃホールディングス株式会社 Aqueous composition for forming secondary battery electrode, secondary battery electrode, and secondary battery
JP2013023654A (en) * 2011-07-25 2013-02-04 Showa Denko Kk Binder for carbon coat foil coating solution, carbon coat foil coating solution, carbon coat foil, electrode for lithium ion secondary battery, and lithium ion secondary battery

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180351177A1 (en) * 2015-12-24 2018-12-06 Lg Chem, Ltd. Binder composition for secondary battery, and electrode for secondary battery and lithium secondary battery comprising the same
US10862126B2 (en) * 2015-12-24 2020-12-08 Lg Chem, Ltd. Binder composition for secondary battery, and electrode for secondary battery and lithium secondary battery comprising the same
KR20190064012A (en) * 2017-11-30 2019-06-10 주식회사 엘지화학 Binder comprising random copolymer, anode for lithium-ion secondary battery comprising the same, lithium-ion secondary battery comprising the anode, and method for polymerizing the copolymer
KR102328256B1 (en) 2017-11-30 2021-11-18 주식회사 엘지에너지솔루션 Binder comprising random copolymer, anode for lithium-ion secondary battery comprising the same, lithium-ion secondary battery comprising the anode, and method for polymerizing the copolymer
CN108155386A (en) * 2018-01-24 2018-06-12 广州鹏辉能源科技股份有限公司 Anode material for lithium-ion batteries, based lithium-ion battery positive plate and preparation method thereof and lithium ion battery
CN108172837A (en) * 2018-01-24 2018-06-15 广州鹏辉能源科技股份有限公司 Lithium ion battery negative material, anode plate for lithium ionic cell and preparation method thereof and lithium ion battery
CN111886719A (en) * 2018-03-29 2020-11-03 日产化学株式会社 Composition for forming undercoat layer of energy storage device
JP2019216035A (en) * 2018-06-13 2019-12-19 三洋化成工業株式会社 Resin collector, lamination type resin collector, and lithium ion battery
JP6998278B2 (en) 2018-06-13 2022-02-10 三洋化成工業株式会社 Resin current collectors, laminated resin current collectors, and lithium-ion batteries
CN113169302A (en) * 2019-03-28 2021-07-23 日本瑞翁株式会社 Conductive material paste for lithium ion secondary battery electrode, slurry composition for lithium ion secondary battery electrode, electrode for lithium ion secondary battery, and lithium ion secondary battery
JP2021039861A (en) * 2019-09-02 2021-03-11 Jsr株式会社 Composition for power storage device, slurry for power storage device electrode, power storage device electrode, and power storage device
WO2021108990A1 (en) * 2019-12-03 2021-06-10 宁德时代新能源科技股份有限公司 Secondary battery and preparation method therefor, and copolymer and device
CN113207315A (en) * 2019-12-03 2021-08-03 宁德时代新能源科技股份有限公司 Composite graphite material, secondary battery, device and preparation method
WO2021108987A1 (en) * 2019-12-03 2021-06-10 宁德时代新能源科技股份有限公司 Composite graphite material, secondary battery, device, and preparation method
CN114175312A (en) * 2019-12-03 2022-03-11 宁德时代新能源科技股份有限公司 Secondary battery, method for producing same, copolymer, and device
JP2022551581A (en) * 2019-12-03 2022-12-12 寧徳時代新能源科技股▲分▼有限公司 SECONDARY BATTERY, METHOD FOR MANUFACTURING THE SAME, COPOLYMER, AND APPARATUS
EP4024532A4 (en) * 2019-12-03 2022-12-28 Contemporary Amperex Technology Co., Limited Secondary battery and preparation method therefor, and copolymer and device
US11710822B2 (en) 2019-12-03 2023-07-25 Contemporary Amperex Technology Co., Limited Composite graphite material, secondary battery, apparatus and preparation method thereof
CN113207315B (en) * 2019-12-03 2024-05-10 宁德时代新能源科技股份有限公司 Composite graphite material, secondary battery, device and preparation method
CN114175312B (en) * 2019-12-03 2024-05-17 宁德时代新能源科技股份有限公司 Secondary battery, method for preparing the same, and copolymer and device
WO2021253616A1 (en) * 2020-06-17 2021-12-23 Guangdong Haozhi Technology Co. Limited Binder composition for secondary battery
WO2024062881A1 (en) * 2022-09-22 2024-03-28 株式会社豊田自動織機 Electrode for power storage device, and method for producing composite material for active material layer

Also Published As

Publication number Publication date
JPWO2015146787A1 (en) 2017-04-13
JP6519581B2 (en) 2019-05-29

Similar Documents

Publication Publication Date Title
JP6519581B2 (en) Conductive adhesive composition for electrochemical element electrode and current collector for electrochemical element electrode
JP6152855B2 (en) Conductive adhesive composition for electrochemical element electrode, current collector with adhesive layer, and electrode for electrochemical element
JP5967098B2 (en) Conductive adhesive composition, current collector with adhesive layer, and electrochemical element electrode
JP5761197B2 (en) Secondary battery negative electrode binder composition, secondary battery negative electrode slurry composition, secondary battery negative electrode, secondary battery, and method for producing secondary battery negative electrode binder composition
JP6417943B2 (en) Slurry for positive electrode of lithium ion secondary battery
JP5942992B2 (en) Conductive adhesive composition for electrochemical element electrode, current collector with adhesive layer, and electrochemical element electrode
KR102184050B1 (en) Lithium ion secondary battery
TWI431842B (en) Electrode binder composition, electrode slurry, electrode, and electrical storage device
WO2014051067A1 (en) Lithium ion secondary battery
WO2013183717A1 (en) Negative electrode slurry composition, lithium ion secondary cell negative electrode, and lithium ion secondary cell
CN110383546B (en) Conductive material dispersion for electrochemical element electrode, slurry composition and method for producing same, electrode, and electrochemical element
JP6417722B2 (en) Conductive adhesive composition for electrochemical element electrode, current collector with adhesive layer, and electrode for electrochemical element
JP6070204B2 (en) Conductive adhesive composition for electrochemical element electrode
JP5459526B1 (en) Binder composition for power storage device, slurry for power storage device electrode, power storage device electrode, slurry for protective film formation, protective film, and power storage device
JP5862909B2 (en) Lithium ion secondary battery
JP6048636B2 (en) Electrode binder composition, electrode slurry, electrode, and method for producing electricity storage device
JP2014212132A (en) Lithium ion secondary battery
JP6759589B2 (en) Conductive composition for electrochemical element, composition for electrochemical element electrode, current collector with adhesive layer and electrode for electrochemical element
JP6273948B2 (en) Conductive adhesive composition for electrochemical element electrode, current collector with adhesive layer, and electrode for electrochemical element
JP6822892B2 (en) Secondary battery negative electrode slurry, secondary battery electrode, secondary battery, secondary battery electrode manufacturing method, and use of water-soluble binder as secondary battery negative electrode slurry
JP6582879B2 (en) Electroconductive element conductive composition, electrochemical element electrode composition, current collector with adhesive layer, and electrochemical element electrode
JP6197725B2 (en) Method for producing slurry composition for secondary battery
JP5880900B2 (en) Lithium ion secondary battery
JP2012169292A (en) Binder composite for secondary battery electrode, slurry for secondary battery electrode, and secondary battery electrode

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15769667

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2016510285

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase
122 Ep: pct application non-entry in european phase

Ref document number: 15769667

Country of ref document: EP

Kind code of ref document: A1