WO2019188545A1 - Composition pour former un film mince conducteur - Google Patents

Composition pour former un film mince conducteur Download PDF

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WO2019188545A1
WO2019188545A1 PCT/JP2019/011339 JP2019011339W WO2019188545A1 WO 2019188545 A1 WO2019188545 A1 WO 2019188545A1 JP 2019011339 W JP2019011339 W JP 2019011339W WO 2019188545 A1 WO2019188545 A1 WO 2019188545A1
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group
composition
thin film
conductive thin
energy storage
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PCT/JP2019/011339
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Japanese (ja)
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辰也 畑中
康志 境田
瞬 藤田
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日産化学株式会社
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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/02—Elements
    • C08K3/04—Carbon
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L101/00—Compositions of unspecified macromolecular compounds
    • C08L101/12—Compositions of unspecified macromolecular compounds characterised by physical features, e.g. anisotropy, viscosity or electrical conductivity
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D1/00—Coating compositions, e.g. paints, varnishes or lacquers, based on inorganic substances
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
    • C09D5/24—Electrically-conducting paints
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
    • C09D7/40—Additives
    • C09D7/60—Additives non-macromolecular
    • C09D7/63—Additives non-macromolecular organic
    • 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
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B5/00—Non-insulated conductors or conductive bodies characterised by their form
    • H01B5/16—Non-insulated conductors or conductive bodies characterised by their form comprising conductive material in insulating or poorly conductive material, e.g. conductive rubber
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-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
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-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
    • H01G11/30—Electrodes characterised by their material
    • H01G11/32—Carbon-based
    • H01G11/36—Nanostructures, e.g. nanofibres, nanotubes or fullerenes
    • 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
    • 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
    • H01M4/04—Processes of manufacture in general
    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a composition for forming a conductive thin film.
  • a lithium ion secondary battery is a secondary battery that has been developed most vigorously at present because it has a high energy density and a high voltage and has no memory effect during charging and discharging.
  • the development of electric vehicles has been actively promoted due to recent efforts to deal with environmental problems, and higher performance has been demanded for secondary batteries as a power source.
  • a lithium ion secondary battery contains a positive electrode and a negative electrode capable of occluding and releasing lithium, and a separator interposed therebetween in a container, and an electrolyte solution (liquid in the case of a lithium ion polymer secondary battery) therein. It has a structure filled with a gel-like or all solid electrolyte instead of the electrolyte.
  • an active material capable of occluding and releasing lithium, a conductive material mainly composed of a carbon material, and a composition containing a polymer binder are generally applied on a current collector such as a copper foil or an aluminum foil. It is manufactured by doing.
  • This binder is used to bond an active material and a conductive material, and further to the metal foil, and is a fluorine-based resin soluble in N-methylpyrrolidone (NMP) such as polyvinylidene fluoride (PVdF) or an olefin-based heavy polymer.
  • NMP N-methylpyrrolidone
  • PVdF polyvinylidene fluoride
  • olefin-based heavy polymer Combined aqueous dispersions are commercially available.
  • the adhesive strength of the binder to the current collector is not sufficient, and a part of the active material or conductive material is peeled off from the current collector during the manufacturing process such as the electrode cutting process or the winding process. , Causing a short circuit and variation in battery capacity.
  • the contact resistance between the electrode mixture and the current collector increases due to the volume change of the electrode mixture due to the swelling of the binder due to the electrolytic solution and the volume change due to the lithium occlusion and release of the active material after long-term use.
  • battery capacity is deteriorated due to part of the active material or conductive material peeling off from the current collector or dropping off, and further, there is a problem in terms of safety.
  • Patent Document 1 discloses a technique in which a conductive layer containing carbon as a conductive filler is used as an undercoat layer and disposed between a current collector and an electrode mixture layer, and the undercoat layer is provided.
  • a conductive layer containing carbon as a conductive filler is used as an undercoat layer and disposed between a current collector and an electrode mixture layer, and the undercoat layer is provided.
  • Patent Document 2 and Patent Document 3 disclose similar techniques.
  • Patent Document 4 and Patent Document 5 disclose an undercoat layer using carbon nanotubes (hereinafter also abbreviated as CNT) as a conductive filler.
  • CNT carbon nanotubes
  • the undercoat is expected not only to lower the resistance of the battery but also to suppress the increase in resistance, but depending on the conductive carbon material used, the resistance of the battery is increased and the resistance increase is accelerated. There is a case to let you. In this regard, it is not clear what conductive carbon material is used to reduce the resistance of the battery and suppress the increase in resistance.
  • This invention is made
  • the present inventors have used a carbon nanotube having an average diameter in a specific range in the composition for forming a conductive thin film, thereby reducing the resistance and increasing the resistance.
  • the inventors have found that a composition capable of providing an undercoat layer exhibiting an inhibitory effect can be obtained, and the present invention has been completed.
  • the present invention 1. Including carbon nanotubes, carbon nanotube dispersant, and solvent, A composition for forming a conductive thin film, wherein the carbon nanotube has an average diameter of 5 to 23 nm, 2. 1. The composition for forming a conductive thin film having an average diameter of 5 to 22.5 nm, 3. 1 or 2 composition for forming a conductive thin film, wherein the standard deviation of the average diameter is 4 nm or less, 4). 3. The composition for forming a conductive thin film according to 3, wherein the standard deviation of the average diameter is 3.5 nm or less, 5. The composition for forming a conductive thin film according to any one of 1 to 4 having a solid content concentration of 20% by mass or less; 6). 5.
  • composition for forming an electroconductive thin film wherein the solid content concentration is 15% by mass or less, 7. 6.
  • the composition for forming a conductive thin film, wherein the solid content concentration is 10% by mass or less, 8).
  • undercoat layers for energy storage devices wherein the weight per unit area is 300 mg / m 2 or less, 17. 16 undercoat layers for energy storage devices, wherein the basis weight is 200 mg / m 2 or less, 18.
  • a composite current collector for an electrode of an energy storage device comprising the undercoat layer of any one of 13 to 17, 19.
  • An electrode for an energy storage device comprising a composite current collector for an electrode of 18 energy storage devices; 20.
  • Energy storage device comprising 19 energy storage device electrodes, 21. Twenty energy storage devices that are lithium ion batteries are provided.
  • the composition for forming an electroconductive thin film of the present invention is suitable as a composition for forming an undercoat layer that joins a current collector constituting an electrode of an energy storage device and an active material, etc.
  • a composition for forming an undercoat layer on the current collector By using and forming an undercoat layer on the current collector, the resistance of the energy storage device can be reduced, and an increase in resistance can be suppressed.
  • 2 is a transmission electron microscope image of VGCF-X (manufactured by Showa Denko KK), which is a multilayer CNT.
  • It is a transmission electron microscope image of C-100 (manufactured by Arkema Co.), which is a multilayer CNT.
  • Baytubes made by BAYER which is multilayer CNT.
  • the composition for forming a conductive thin film according to the present invention includes CNT, a CNT dispersant, and a solvent, and the average diameter of the CNT is 5 to 23 nm.
  • the diameter of the CNT is based on an image taken at a magnification of 50,000 to 100,000 by observation with a transmission electron microscope (TEM), for example, H-8000 manufactured by Hitachi, Ltd. It can be determined by direct measurement.
  • the average diameter of CNT is obtained by photographing a plurality of randomly selected CNTs by TEM observation, measuring the diameter at a plurality of locations randomly selected for each photographed CNT, It is an average value obtained from the value. For example, four randomly selected CNTs are photographed, the diameter is measured at five randomly selected points for each photographed CNT, and an average value may be obtained from the measured values obtained at a total of 20 points. .
  • the average diameter of the CNT is 5 to 23 nm, preferably 5 to 22.5 nm, from the viewpoint of reducing the resistance of the device and exhibiting the resistance increase suppressing effect.
  • the standard deviation of the average diameter is preferably 4 nm or less, more preferably 3.8 nm or less, and still more preferably 3.5 nm or less.
  • the CNT is not particularly limited as long as the average diameter satisfies the above range.
  • CNTs are generally produced by arc discharge, chemical vapor deposition (CVD), laser ablation, etc., but the CNTs used in the present invention may be obtained by any method.
  • a single-layer CNT hereinafter also abbreviated as SWCNT
  • SWCNT single-layer CNT
  • DWCNT single carbon film
  • MWCNT multi-layer CNT
  • each of SWCNT, DWCNT, and MWCNT is used alone or a plurality Can be used in combination.
  • catalyst metal such as nickel, iron, cobalt, yttrium may remain, and thus purification for removing this impurity is required.
  • ultrasonic treatment is effective together with acid treatment with nitric acid, sulfuric acid and the like.
  • acid treatment with nitric acid, sulfuric acid or the like destroys the ⁇ -conjugated system constituting CNT and may impair the original characteristics of CNT. Therefore, it is desirable to purify and use under appropriate conditions.
  • the CNT it is preferable to use a CNT that is easy to disperse in the dispersion liquid in order to exert an effect of lowering the battery resistance when the dispersion liquid is used as an undercoat layer.
  • Such CNTs preferably have many crystal discontinuities that can be easily cut with small energy.
  • the CNT used in the composition of the present invention preferably has a constricted portion.
  • the CNT having a constricted portion is a CNT wall having a constricted portion having a tube outer diameter of 90% or less of the parallel portion and the tube outer diameter of the parallel portion. Since this constricted part is a part created by changing the growth direction of CNTs, it has a discontinuous crystal part and becomes an easily breakable part that can be easily cut with a small mechanical energy.
  • FIG. 1 shows a schematic cross-sectional view of a CNT having a parallel portion 1 and a constricted portion 3.
  • the parallel part 1 is a part where the wall can be recognized as two parallel straight lines or two parallel curves.
  • the distance between the outer walls of the parallel line in the normal direction is the tube outer diameter 2 of the parallel part 1.
  • the constricted portion 3 is a portion where both ends thereof are connected to the parallel portion 1 and the distance between the walls is closer than that of the parallel portion 1, more specifically, the tube outer diameter 2 of the parallel portion 1 is increased.
  • it is a portion having a tube outer diameter 4 of 90% or less.
  • the tube outer diameter 4 of the constricted portion 3 is the distance between the outer walls of the constricted portion 3 where the wall constituting the outer wall is closest. As shown in FIG. 1, many of the constricted portions 3 have portions where crystals are discontinuous.
  • the shape of the CNT wall and the outer diameter of the tube can be observed with a transmission electron microscope or the like. Specifically, it is possible to prepare a 0.5% dispersion of CNT, dry the dispersion on a sample stage, and confirm the constricted portion by an image taken at 50,000 times with a transmission electron microscope. it can.
  • the CNT For the CNT, a 0.1% dispersion of CNT was prepared, the dispersion was placed on a sample stage and dried, and an image taken at 20,000 times with a transmission electron microscope was divided into 100 nm square sections, and 100 nm When 300 sections with CNT occupying 10% to 80% in all four sections are selected, the total number of easily breakable portions depends on the ratio of the section with at least one constricted portion in one section to 300 sections. The ratio (the ratio of the presence of easily breakable parts) is determined. When the area occupied by CNTs in the compartment is less than 10%, measurement is difficult because the amount of CNTs is too small.
  • the existence ratio of easily breakable portions is 60% or more.
  • the proportion of easily breakable portions is less than 60%, CNT is difficult to disperse, and when excessive mechanical energy is applied to disperse, it leads to the destruction of the crystal structure of the graphite surface, which is a characteristic of CNT. Characteristics such as electrical conductivity are reduced.
  • the presence ratio of easily breakable portions is preferably 70% or more.
  • CNTs usable in the present invention include TC-2010, TC-2020, TC-, which are CNTs having a constricted structure disclosed in International Publication Nos. 2016/076393 and JP-A-2017-206413.
  • TC series such as 3210L and TC-1210LN (manufactured by Toda Kogyo Co., Ltd.), spar-growth CNT (manufactured by New Energy and Industrial Technology Development Organization), eDIPS-CNT (new energy and industry, national research and development corporation) SWNT series (made by Meijo Nanocarbon Co., Ltd .: trade name), VGCF series (made by Showa Denko KK: trade name), FloTube series (made by CNano Technology Co., Ltd .: trade name), AMC ( Ube Industries, Ltd.
  • the dispersant can be appropriately selected from those conventionally used as a dispersant for conductive carbon materials such as CNTs.
  • CMC carboxymethylcellulose
  • PVP polyvinylpyrrolidone
  • acrylic resin emulsion water-soluble Acrylic polymer
  • styrene emulsion silicone emulsion
  • acrylic silicone emulsion fluororesin emulsion
  • EVA emulsion vinyl acetate emulsion
  • vinyl chloride emulsion urethane resin emulsion
  • triarylamine hyperbranched polymer described in International Publication No. 2014/04280
  • polymers having an oxazoline group in the side chain described in International Publication No. 2015/029949 polymers having an oxazoline group in the side chain described in International Publication No. 2015/029949.
  • the side chain described in International Publication No. 2015/029949 is included in the side chain.
  • Dispersing agents and comprising a polymer having a Kisazorin group it is preferable to use a dispersant comprising a triarylamine hyperbranched polymer of WO 2014/04280 Patent forth.
  • a polymer having an oxazoline group in the side chain (hereinafter referred to as oxazoline polymer) is obtained by radical polymerization of an oxazoline monomer having a polymerizable carbon-carbon double bond-containing group at the 2-position as shown in Formula (1).
  • oxazoline polymer is obtained by radical polymerization of an oxazoline monomer having a polymerizable carbon-carbon double bond-containing group at the 2-position as shown in Formula (1).
  • Preferred is a vinyl polymer having a repeating unit bonded to the polymer main chain or spacer group at the 2-position of the oxazoline ring and having an oxazoline group in the side chain.
  • X represents a polymerizable carbon-carbon double bond-containing group
  • R 1 to R 4 are independently of each other a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a 6 to 20 carbon atoms.
  • An aryl group or an aralkyl group having 7 to 20 carbon atoms is represented.
  • the polymerizable carbon-carbon double bond-containing group of the oxazoline monomer is not particularly limited as long as it contains a polymerizable carbon-carbon double bond, but a chain containing a polymerizable carbon-carbon double bond.
  • a hydrocarbon group having 2 to 8 carbon atoms such as vinyl group, allyl group and isopropenyl group is preferable.
  • examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
  • the alkyl group having 1 to 5 carbon atoms may be linear, branched or cyclic, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group. Tert-butyl group, n-pentyl group, cyclohexyl group and the like.
  • Specific examples of the aryl group having 6 to 20 carbon atoms include phenyl group, xylyl group, tolyl group, biphenylyl group, naphthyl group and the like.
  • Specific examples of the aralkyl group having 7 to 20 carbon atoms include benzyl group, phenylethyl group, phenylcyclohexyl group and the like.
  • oxazoline monomer having a polymerizable carbon-carbon double bond-containing group at the 2-position represented by the formula (1) include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-4-ethyl-2-oxazoline, 2-vinyl-4-propyl-2-oxazoline, 2-vinyl-4-butyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2- Vinyl-5-ethyl-2-oxazoline, 2-vinyl-5-propyl-2-oxazoline, 2-vinyl-5-butyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4- Methyl-2-oxazoline, 2-isopropenyl-4-ethyl-2-oxazoline, 2-isopropenyl-4-propyl-2-oxazoline, 2- Sopropenyl-4-butyl
  • the oxazoline polymer is also preferably water-soluble.
  • a water-soluble oxazoline polymer may be a homopolymer of the oxazoline monomer represented by the above formula (1), but has a oxazoline monomer and a hydrophilic functional group in order to further enhance the solubility in water (meta ) It is preferable to be obtained by radical polymerization of at least two monomers with an acrylate monomer.
  • (meth) acrylic monomer having a hydrophilic functional group examples include (meth) acrylic acid, 2-hydroxyethyl acrylate, methoxypolyethylene glycol acrylate, monoesterified product of acrylic acid and polyethylene glycol, acrylic acid 2-aminoethyl and its salt, 2-hydroxyethyl methacrylate, methoxypolyethylene glycol methacrylate, monoesterified product of methacrylic acid and polyethylene glycol, 2-aminoethyl methacrylate and its salt, sodium (meth) acrylate, ( Ammonium methacrylate, (meth) acrylonitrile, (meth) acrylamide, N-methylol (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide, sodium styrenesulfonate, etc. The like, which may be used singly or may be used in combination of two or more. Among these, (meth) acrylic acid methoxypolyethylene glycol and mono
  • (Meth) acrylic acid ester monomers such as perfluoroethyl acid and phenyl (meth) acrylate; ⁇ -olefin monomers such as ethylene, propylene, butene and pentene; haloolefins such as vinyl chloride, vinylidene chloride and vinyl fluoride Monomers: Styrene monomers such as styrene and ⁇ -methylstyrene; Vinyl ester monomers such as vinyl acetate and vinyl propionate; Vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether, and the like. Even two or more You may use it in combination.
  • the content of the oxazoline monomer is preferably 10% by mass or more, more preferably 20% by mass or more from the viewpoint of further increasing the CNT dispersibility of the obtained oxazoline polymer. Preferably, 30% by mass or more is even more preferable.
  • the upper limit of the content rate of the oxazoline monomer in a monomer component is 100 mass%, and the homopolymer of an oxazoline monomer is obtained in this case.
  • the content of the (meth) acrylic monomer having a hydrophilic functional group in the monomer component is preferably 10% by mass or more, more preferably 20% by mass or more from the viewpoint of further increasing the water solubility of the obtained oxazoline polymer. 30% by mass or more is even more preferable.
  • the content of other monomers in the monomer component is a range that does not affect the CNT dispersibility of the obtained oxazoline polymer, and since it varies depending on the type, it cannot be determined unconditionally. What is necessary is just to set suitably in the range of 5-95 mass%, Preferably it is 10-90 mass%.
  • the average molecular weight of the oxazoline polymer is not particularly limited, but the weight average molecular weight is preferably 1,000 to 2,000,000, and more preferably 2,000 to 1,000,000.
  • the weight average molecular weight is a polystyrene conversion value determined by gel permeation chromatography.
  • the oxazoline polymer that can be used in the present invention can be synthesized by a conventional radical polymerization of the above-mentioned monomers, but can also be obtained as a commercial product, and as such a commercial product, for example, Epocross WS-300 (Manufactured by Nippon Shokubai Co., Ltd., solid content concentration 10% by mass, aqueous solution), Epocross WS-700 (manufactured by Nippon Shokubai Co., Ltd., solid content concentration 25% by mass, aqueous solution), Epocross WS-500 (manufactured by Nippon Shokubai Co., Ltd.) Manufactured, solid content concentration 39% by mass, water / 1-methoxy-2-propanol solution), Poly (2-ethyl-2-oxazoline) (Aldrich), Poly (2-ethyl-2-oxazoline) (AlfaAesar), Poly (2-ethyl-2-oxazole) (
  • a triarylamine-based hyperbranched polymer obtained by condensation polymerization of triarylamines and aldehydes and / or ketones represented by the following formulas (2) and (3) under acidic conditions is also suitable. Used.
  • Ar 1 to Ar 3 each independently represents any divalent organic group represented by formulas (4) to (8).
  • the substituted or unsubstituted phenylene group represented by (4) is preferred.
  • Z 1 and Z 2 are each independently a hydrogen atom, an alkyl group which may have a branched structure having 1 to 5 carbon atoms, or the formula (9) (1) represents any monovalent organic group represented by (12) (provided that Z 1 and Z 2 do not simultaneously become the above alkyl group), but Z 1 and Z 2 are each independently A hydrogen atom, a 2- or 3-thienyl group, or a group represented by the formula (9) is preferable, and in particular, one of Z 1 and Z 2 is a hydrogen atom, and the other is a hydrogen atom, 2- or More preferred is a 3-thienyl group, a group represented by the formula (9), particularly those in which R 141 is a phenyl group, or R 141 is a methoxy group.
  • R 141 is a phenyl group
  • an acidic group may be introduced onto the phenyl group when a method for introducing an acidic group after polymer production is used in the acidic group introduction method described later.
  • alkyl group which may have a branched structure having 1 to 5 carbon atoms include those similar to those exemplified above.
  • R 101 to R 138 are each independently a hydrogen atom, a halogen atom, an alkyl group which may have a branched structure having 1 to 5 carbon atoms, or a carbon number of 1 Represents an alkoxy group which may have a branched structure of 1 to 5, a carboxyl group, a sulfo group, a phosphoric acid group, a phosphonic acid group or a salt thereof;
  • examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
  • examples of the alkyl group which may have a branched structure having 1 to 5 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n -Pentyl group and the like.
  • alkoxy group which may have a branched structure having 1 to 5 carbon atoms include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, Examples thereof include an n-pentoxy group.
  • salts of carboxyl group, sulfo group, phosphoric acid group and phosphonic acid group include alkali metal salts such as sodium and potassium; group 2 metal salts such as magnesium and calcium; ammonium salts; propylamine, dimethylamine, triethylamine, ethylenediamine, etc. Aliphatic amine salts; alicyclic amine salts such as imidazoline, piperazine and morpholine; aromatic amine salts such as aniline and diphenylamine; and pyridinium salts.
  • R 139 to R 162 are each independently a hydrogen atom, a halogen atom, an alkyl group which may have a branched structure having 1 to 5 carbon atoms, or a carbon number of 1 Haloalkyl group, phenyl group, OR 163 , COR 163 , NR 163 R 164 , COOR 165 , which may have a branched structure of ⁇ 5 (in these formulas, R 163 and R 164 are each independently hydrogen Represents an atom, an alkyl group which may have a branched structure having 1 to 5 carbon atoms, a haloalkyl group which may have a branched structure having 1 to 5 carbon atoms, or a phenyl group, and R 165 represents the number of carbon atoms Represents an alkyl group which may have a branched structure of 1 to 5, a haloalkyl group which may have a branched structure of 1 to 5 carbon
  • the haloalkyl group which may have a branched structure having 1 to 5 carbon atoms includes difluoromethyl group, trifluoromethyl group, bromodifluoromethyl group, 2-chloroethyl group, 2-bromoethyl group, 1,1 -Difluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, 2-chloro-1,1,2-trifluoroethyl group, pentafluoroethyl group, 3 -Bromopropyl group, 2,2,3,3-tetrafluoropropyl group, 1,1,2,3,3,3-hexafluoropropyl group, 1,1,1,3,3,3-hexafluoropropane Examples include -2-yl group, 3-bromo-2-methylpropyl group, 4-bromobutyl group, perfluoropentyl group and the like. Examples of the halogen
  • the hyperbranched polymer has a carboxyl group, in at least one aromatic ring of the repeating unit represented by the formula (2) or (3), Those having at least one acidic group selected from a sulfo group, a phosphoric acid group, a phosphonic acid group, and salts thereof are preferable, and those having a sulfo group or a salt thereof are more preferable.
  • aldehyde compound used for the production of the hyperbranched polymer examples include formaldehyde, paraformaldehyde, acetaldehyde, propylaldehyde, butyraldehyde, isobutyraldehyde, valeraldehyde, capronaldehyde, 2-methylbutyraldehyde, hexylaldehyde, undecylaldehyde, 7 -Saturated aliphatic aldehydes such as methoxy-3,7-dimethyloctylaldehyde, cyclohexanecarboxaldehyde, 3-methyl-2-butyraldehyde, glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipine aldehyde; acrolein, methacrolein Unsaturated aldehydes such as: furfural, pyridine aldehy
  • Examples of the ketone compound used in the production of the hyperbranched polymer include alkyl aryl ketones and diaryl ketones, such as acetophenone, propiophenone, diphenyl ketone, phenyl naphthyl ketone, dinaphthyl ketone, phenyl tolyl ketone, and ditolyl ketone. Etc.
  • the hyperbranched polymer used in the present invention includes, for example, a triarylamine compound that can give the above-described triarylamine skeleton as represented by the following formula (A), and the following formula, for example: It can be obtained by condensation polymerization of an aldehyde compound and / or a ketone compound as shown in (B) in the presence of an acid catalyst.
  • a bifunctional compound (C) such as phthalaldehyde such as terephthalaldehyde is used as the aldehyde compound, not only the reaction shown in Scheme 1 but also the reaction shown in Scheme 2 below occurs.
  • a hyperbranched polymer having a crosslinked structure in which two functional groups contribute to the condensation reaction may be obtained.
  • an aldehyde compound and / or a ketone compound can be used at a ratio of 0.1 to 10 equivalents with respect to 1 equivalent of the aryl group of the triarylamine compound.
  • the acid catalyst include mineral acids such as sulfuric acid, phosphoric acid and perchloric acid; organic sulfonic acids such as p-toluenesulfonic acid and p-toluenesulfonic acid monohydrate; carboxylic acids such as formic acid and oxalic acid. Etc. can be used.
  • the amount of the acid catalyst to be used is variously selected depending on the kind thereof, but is usually 0.001 to 10,000 parts by mass, preferably 0.01 to 1,000 parts by mass with respect to 100 parts by mass of the triarylamines. Part, more preferably 0.1 to 100 parts by weight.
  • the above condensation reaction can be carried out without a solvent, it is usually carried out using a solvent.
  • Any solvent that does not inhibit the reaction can be used.
  • cyclic ethers such as tetrahydrofuran and 1,4-dioxane; N, N-dimethylformamide (DMF), N, N-dimethylacetamide ( DMAc), amides such as N-methyl-2-pyrrolidone (NMP); ketones such as methyl isobutyl ketone and cyclohexanone; halogenated hydrocarbons such as methylene chloride, chloroform, 1,2-dichloroethane and chlorobenzene; benzene, Examples thereof include aromatic hydrocarbons such as toluene and xylene, and cyclic ethers are particularly preferable.
  • These solvents can be used alone or in combination of two or more.
  • the acid catalyst used is a liquid such as formic acid, the acid catalyst can also serve as a solvent.
  • the reaction temperature during the condensation is usually 40 to 200 ° C.
  • the reaction time is variously selected depending on the reaction temperature, but is usually about 30 minutes to 50 hours.
  • the obtained hyperbranched polymer may be introduced by a method of treating with a reagent capable of introducing an acidic group on the aromatic ring, but the latter method may be used in consideration of the ease of production. preferable.
  • the method for introducing the acidic group onto the aromatic ring is not particularly limited, and may be appropriately selected from conventionally known various methods according to the type of the acidic group. For example, when a sulfo group is introduced, a technique of sulfonation using an excessive amount of sulfuric acid can be used.
  • the average molecular weight of the hyperbranched polymer is not particularly limited, but the weight average molecular weight is preferably 1,000 to 2,000,000, and more preferably 2,000 to 1,000,000.
  • Specific examples of the hyperbranched polymer include, but are not limited to, those represented by the following formula.
  • the mixing ratio of the CNT and the dispersant can be about 1,000: 1 to 1: 100 by mass ratio.
  • the concentration of the dispersant in the composition is not particularly limited as long as it is a concentration capable of dispersing CNTs in a solvent, but is preferably about 0.001 to 30% by mass in the composition, More preferably, it is about 0.002 to 20% by mass.
  • the concentration of CNT in the composition varies in the weight per unit area of the target undercoat layer and the required mechanical, electrical, and thermal characteristics, and at least a part of the CNT, etc. Is as long as the undercoat layer can be produced in a range of practical weight per unit area, but is preferably about 0.0001 to 30% by mass, preferably about 0.001 to 20% by mass in the composition. More preferred is about 0.001 to 10% by mass.
  • the solvent is not particularly limited as long as it is conventionally used for the preparation of a conductive composition.
  • ethers such as tetrahydrofuran (THF), diethyl ether, 1,2-dimethoxyethane (DME); Halogenated hydrocarbons such as methylene chloride, chloroform, 1,2-dichloroethane; N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), etc.
  • Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone
  • Alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, t-butanol; n-heptane, n-hexane, cyclohexane, etc.
  • Aliphatic hydrocarbons such as ethylene, xylene and ethylbenzene
  • Aromatic hydrocarbons such as ethylene, xylene and ethylbenzene
  • glycol ethers such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether and propylene glycol monomethyl ether
  • organic solvents such as glycols such as ethylene glycol and propylene glycol .
  • These solvent can be used individually by 1 type or in mixture of 2 or more types.
  • water, NMP, DMF, THF, methanol, ethanol, n-propanol, isopropanol, n-butanol, and t-butanol are preferable because the ratio of isolated dispersion of CNT can be improved.
  • methanol, ethanol, n-propanol, isopropanol, n-butanol, and t-butanol are preferable from the point that cost can be reduced.
  • these solvents can be used singly or in combination of two or more for the purpose of increasing the ratio of isolated dispersion, increasing the coatability, and reducing the cost.
  • a polymer serving as a matrix may be added.
  • the matrix polymer include polyvinylidene fluoride (PVdF), polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, vinylidene fluoride-hexafluoropropylene copolymer [P (VDF-HFP)], Fluorine resins such as vinylidene fluoride-trichloroethylene copolymer [P (VDF-CTFE)]; polyvinylpyrrolidone, ethylene-propylene-diene terpolymer, PE (polyethylene), PP (polypropylene), Polyolefin resins such as EVA (ethylene-vinyl acetate copolymer), EEA (ethylene-ethyl acrylate copolymer); PS (polystyrene), HIPS (high impact polystyrene), AS (acrylonitrile-st
  • PVdF polyvin
  • Examples thereof include sodium boxymethylcellulose, water-soluble cellulose ether, sodium alginate, polyvinyl alcohol, polystyrene sulfonic acid, polyethylene glycol and the like, and particularly, sodium polyacrylate and sodium carboxymethylcellulose are preferable.
  • the matrix polymer can also be obtained as a commercial product.
  • a commercial product examples include sodium polyacrylate (manufactured by Wako Pure Chemical Industries, Ltd., degree of polymerization 2,700 to 7,500), carboxy Sodium methylcellulose (manufactured by Wako Pure Chemical Industries, Ltd.), sodium alginate (manufactured by Kanto Chemical Co., Ltd., deer grade 1), Metrol's SH series (hydroxypropylmethylcellulose, Shin-Etsu Chemical Co., Ltd.), Metrolose SE series (hydroxyl) Ethyl methyl cellulose, manufactured by Shin-Etsu Chemical Co., Ltd.), JC-25 (completely saponified polyvinyl alcohol, manufactured by Nippon Vineyard Poval Co., Ltd.), JM-17 (intermediate saponified polyvinyl alcohol, Nippon Vinegared / Poval) Manufactured by Co., Ltd.), JP-03 (partially saponified polyvinyl alcohol, Nippon Vinegar Po
  • the composition of the present invention may contain a crosslinking agent that causes a crosslinking reaction with the dispersant to be used or a crosslinking agent that self-crosslinks. These crosslinking agents are preferably dissolved in the solvent used.
  • the crosslinking agent for the oxazoline polymer is particularly limited as long as it is a compound having two or more functional groups having reactivity with an oxazoline group such as a carboxyl group, a hydroxyl group, a thiol group, an amino group, a sulfinic acid group, and an epoxy group. Although not intended, compounds having two or more carboxyl groups are preferred.
  • a compound having a functional group that causes a crosslinking reaction by heating during thin film formation or in the presence of an acid catalyst such as a sodium salt, potassium salt, lithium salt, or ammonium salt of a carboxylic acid is also crosslinked. It can be used as an agent.
  • an acid catalyst such as a sodium salt, potassium salt, lithium salt, or ammonium salt of a carboxylic acid
  • Specific examples of compounds that undergo a crosslinking reaction with an oxazoline group include metal salts of synthetic polymers such as polyacrylic acid and copolymers thereof and natural polymers such as carboxymethylcellulose and alginic acid that exhibit crosslinking reactivity in the presence of an acid catalyst.
  • ammonium salts of the above synthetic polymers and natural polymers that exhibit crosslinking reactivity by heating especially sodium polyacrylate that exhibits crosslinking reactivity in the presence of an acid catalyst or under heating conditions, Preference is given to lithium polyacrylate, ammonium polyacrylate, sodium carboxymethylcellulose, lithium carboxymethylcellulose, carboxymethylcellulose ammonium and the like.
  • Such a compound that causes a crosslinking reaction with an oxazoline group can also be obtained as a commercial product.
  • a commercial product examples include sodium polyacrylate (manufactured by Wako Pure Chemical Industries, Ltd., degree of polymerization of 2, 700-7,500), sodium carboxymethylcellulose (manufactured by Wako Pure Chemical Industries, Ltd.), sodium alginate (manufactured by Kanto Chemical Co., Ltd., deer grade 1), Aron A-30 (ammonium polyacrylate, Toagosei Co., Ltd.) ), Solid concentration 32% by mass, aqueous solution), DN-800H (carboxymethylcellulose ammonium, manufactured by Daicel Finechem Co., Ltd.), ammonium alginate (produced by Kimika Co., Ltd.), and the like.
  • crosslinking agent for the triarylamine-based hyperbranched polymer examples include melamine-based, substituted urea-based, or their polymer-based crosslinking agents. These crosslinking agents may be used alone or in combination of two or more. Can be used.
  • the cross-linking agent has at least two cross-linking substituents, such as CYMEL (registered trademark), methoxymethylated glycoluril, butoxymethylated glycoluril, methylolated glycoluril, methoxymethylated melamine, butoxymethyl.
  • Melamine methylolated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, methylolated benzoguanamine, methoxymethylated urea, butoxymethylated urea, methylolated urea, methoxymethylated thiourea, methoxymethylated thiourea, methylolated thio
  • Examples include compounds such as urea, and condensates of these compounds.
  • crosslinking agent examples include, for example, an aldehyde group, an epoxy group, a vinyl group, an isocyanate group, an alkoxy group, a carboxyl group, an aldehyde group, an amino group, an isocyanate group, an epoxy group, and an amino group.
  • crosslinkable functional groups that react with each other in the same molecule, such as isocyanate groups and aldehyde groups, hydroxyl groups that react with the same crosslinkable functional groups (dehydration condensation), mercapto groups (disulfide bonds), Examples thereof include compounds having an ester group (Claisen condensation), a silanol group (dehydration condensation), a vinyl group, an acrylic group, and the like.
  • Specific examples of the crosslinking agent that self-crosslinks include polyfunctional acrylate, tetraalkoxysilane, a monomer having a blocked isocyanate group, a hydroxyl group, a carboxylic acid, and an amino group that exhibit crosslinking reactivity in the presence of an acid catalyst.
  • the block copolymer of the monomer which has is mentioned.
  • Such a self-crosslinking crosslinking agent can also be obtained as a commercial product.
  • a commercial product examples include A-9300 (ethoxylated isocyanuric acid triacrylate, Shin-Nakamura Chemical ( ), A-GLY-9E (Ethoxylatedinglycerine triacrylate (EO9 mol), Shin-Nakamura Chemical Co., Ltd.), A-TMMT (pentaerythritol tetraacrylate, Shin-Nakamura Chemical Co., Ltd.), tetraalkoxysilane In the case of tetramethoxysilane (manufactured by Tokyo Chemical Industry Co., Ltd.), tetraethoxysilane (manufactured by Toyoko Chemical Co., Ltd.), and polymers having a blocked isocyanate group, Elastron series E-37, H-3, H38, BAP, NEW BAP-15, C-52, F-2 9, W-11P, MF-9, MF-25K (D
  • the amount of these crosslinking agents to be added varies depending on the solvent used, the substrate used, the required viscosity, the required film shape, etc., but is 0.001 to 80% by mass, preferably 0.8%, based on the dispersant. The amount is from 01 to 50% by mass, more preferably from 0.05 to 40% by mass.
  • These cross-linking agents may cause a cross-linking reaction by self-condensation, but they cause a cross-linking reaction with the dispersant. If a cross-linkable substituent is present in the dispersant, the cross-linking reaction is caused by those cross-linkable substituents. Promoted.
  • a catalyst for accelerating the crosslinking reaction p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluenesulfonic acid, salicylic acid, sulfosalicylic acid, citric acid, benzoic acid, hydroxybenzoic acid, naphthalenecarboxylic acid And / or a thermal acid generator such as 2,4,4,6-tetrabromocyclohexadienone, benzoin tosylate, 2-nitrobenzyl tosylate, and organic sulfonic acid alkyl ester can be added.
  • the addition amount of the catalyst is preferably 0.0001 to 20% by mass, more preferably 0.0005 to 10% by mass, and still more preferably 0.001 to 3% by mass with respect to the CNT dispersant.
  • the method for preparing the composition of the present invention is not particularly limited, and a dispersion is prepared by mixing CNT, a dispersant and a solvent, and a matrix polymer, a crosslinking agent, and the like used as necessary in an arbitrary order. do it. At this time, it is preferable to disperse the mixture, and this treatment can further improve the CNT dispersion ratio.
  • the dispersion treatment include mechanical treatment, wet treatment using a ball mill, bead mill, jet mill, and the like, and ultrasonic treatment using a bath-type or probe-type sonicator. In particular, wet treatment using a jet mill. Or sonication is preferred.
  • the time for the dispersion treatment is arbitrary, but is preferably about 1 minute to 10 hours, and more preferably about 5 minutes to 5 hours. At this time, heat treatment may be performed as necessary.
  • heat treatment may be performed as necessary.
  • the solid content concentration of the composition is not particularly limited, but considering the formation of the undercoat layer with a desired basis weight and film thickness, it is preferably 20% by mass or less, and 15% by mass. The following is more preferable, and 10 mass% or less is still more preferable. Moreover, the minimum is arbitrary, but 0.1 mass% or more is preferable from a practical viewpoint, 0.5 mass% or more is more preferable, and 1 mass% or more is still more preferable.
  • solid content is the total amount of components other than the solvent which comprises a composition.
  • An undercoat foil (composite current collector) can be produced by applying the composition described above to at least one surface of a current collector and naturally or heat-drying it to form an undercoat layer.
  • the thickness of the undercoat layer is preferably 1 nm to 10 ⁇ m, more preferably 1 nm to 1 ⁇ m, and even more preferably 1 to 500 nm in consideration of reducing the internal resistance of the resulting device.
  • the film thickness of the undercoat layer is, for example, by cutting out a test piece of an appropriate size from the undercoat foil, exposing the cross section by a technique such as tearing it by hand, and by microscopic observation such as a scanning electron microscope (SEM), It can obtain
  • SEM scanning electron microscope
  • Basis weight of the undercoat layer per one surface of the current collector is not particularly limited as long as it satisfies the above thickness is preferably 1,000 mg / m 2 or less, more preferably 500 mg / m 2, 300 mg / M 2 or less is even more preferable, and 200 mg / m 2 or less is more preferable.
  • the basis weight of the undercoat layer per side of the current collector is preferably 1 mg / m 2 or more, more preferably 5 mg / m 2. m 2 or more, more preferably 10 mg / m 2 or more, and further preferably 15 mg / m 2 or more.
  • the basis weight of the undercoat layer is the ratio of the mass (mg) of the undercoat layer to the area (m 2 ) of the undercoat layer.
  • the area is an undercoat layer.
  • the area is only the coat layer, and does not include the area of the current collector exposed between the undercoat layers formed in a pattern.
  • the mass of the undercoat layer is obtained by, for example, cutting a test piece of an appropriate size from the undercoat foil, measuring its mass W0, and then peeling off the undercoat layer from the undercoat foil and peeling off the undercoat layer.
  • the mass W1 is measured and calculated from the difference (W0-W1), or the mass W2 of the current collector is measured in advance, and then the mass W3 of the undercoat foil on which the undercoat layer is formed is measured.
  • the difference (W3 ⁇ W2) can be calculated.
  • Examples of the method for removing the undercoat layer include a method of immersing the undercoat layer in a solvent in which the undercoat layer dissolves or swells, and wiping the undercoat layer with a cloth or the like.
  • the basis weight and the film thickness can be adjusted by a known method.
  • the solid content concentration of the coating liquid for forming the undercoat layer (undercoat layer forming composition), the number of times of coating, the coating liquid inlet of the coating machine It can be adjusted by changing the clearance.
  • the solid content concentration is increased, the number of coatings is increased, and the clearance is increased.
  • the solid content concentration is lowered, the number of coatings is reduced, or the clearance is reduced.
  • the current collector those conventionally used as current collectors for electrodes for energy storage devices can be used.
  • copper, aluminum, titanium, stainless steel, nickel, gold, silver and alloys thereof, carbon materials, metal oxides, conductive polymers, etc. can be used, but welding such as ultrasonic welding is applied.
  • a metal foil made of copper, aluminum, titanium, stainless steel, or an alloy thereof it is preferable to use a metal foil made of copper, aluminum, titanium, stainless steel, or an alloy thereof.
  • the thickness of the current collector is not particularly limited, but is preferably 1 to 100 ⁇ m in the present invention.
  • Examples of the method for applying the composition include spin coating, dip coating, flow coating, ink jet, casting, spray coating, bar coating, gravure coating, slit coating, roll coating, and flexographic printing.
  • Method, transfer printing method, brush coating, blade coating method, air knife coating method, die coating method, etc., but from the point of work efficiency etc., inkjet method, casting method, dip coating method, bar coating method, blade coating method A roll coating method, a gravure coating method, a flexographic printing method, a spray coating method, and a die coating method are suitable.
  • the temperature for drying by heating is also arbitrary, but is preferably about 50 to 200 ° C, more preferably about 80 to 150 ° C.
  • the electrode for energy storage devices of the present invention can be produced by forming an electrode mixture layer on the undercoat layer.
  • the energy storage device in the present invention include various energy storage devices such as an electric double layer capacitor, a lithium secondary battery, a lithium ion secondary battery, a proton polymer battery, a nickel hydrogen battery, an aluminum solid capacitor, an electrolytic capacitor, and a lead storage battery.
  • the undercoat foil of the present invention can be suitably used for electric double layer capacitors and lithium ion secondary batteries.
  • an active material the various active materials conventionally used for the electrode for energy storage devices can be used.
  • a chalcogen compound capable of adsorbing / leaving lithium ions or a lithium ion-containing chalcogen compound, a polyanion compound, a simple substance of sulfur and a compound thereof may be used as a positive electrode active material. It can.
  • the chalcogen compound that can adsorb and desorb lithium ions include FeS 2 , TiS 2 , MoS 2 , V 2 O 6 , V 6 O 13 , and MnO 2 .
  • lithium ion-containing chalcogen compound examples include LiCoO 2 , LiMnO 2 , LiMn 2 O 4 , LiMo 2 O 4 , LiV 3 O 8 , LiNiO 2 , Li x Ni y M 1-y O 2 (where M is It represents at least one metal element selected from Co, Mn, Ti, Cr, V, Al, Sn, Pb, and Zn, and 0.05 ⁇ x ⁇ 1.10, 0.5 ⁇ y ⁇ 1.0 ) And the like.
  • the polyanionic compound examples include LiFePO 4 .
  • sulfur compound examples include Li 2 S and rubeanic acid.
  • the negative electrode active material constituting the negative electrode at least one element selected from alkali metals, alkali metal alloys, elements of Groups 4 to 15 of the periodic table that occlude / release lithium ions, oxides, sulfides, A nitride or a carbon material capable of reversibly occluding and releasing lithium ions can be used.
  • alkali metal include Li, Na, and K.
  • alkali metal alloy include Li—Al, Li—Mg, Li—Al—Ni, Na—Hg, and Na—Zn.
  • Examples of the simple substance of at least one element selected from Group 4 to 15 elements of the periodic table that store and release lithium ions include silicon, tin, aluminum, zinc, and arsenic.
  • examples of the oxide include tin silicon oxide (SnSiO 3 ), lithium bismuth oxide (Li 3 BiO 4 ), lithium zinc oxide (Li 2 ZnO 2 ), lithium titanium oxide (Li 4 Ti 5 O 12 ), and oxidation.
  • examples include titanium.
  • examples of the sulfide include lithium iron sulfide (Li x FeS 2 (0 ⁇ x ⁇ 3)) and lithium copper sulfide (Li x CuS (0 ⁇ x ⁇ 3)).
  • the carbon material capable of reversibly occluding and releasing lithium ions include graphite, carbon black, coke, glassy carbon, carbon fiber, carbon nanotube, and a sintered body thereof.
  • a carbonaceous material can be used as an active material.
  • the carbonaceous material include activated carbon and the like, for example, activated carbon obtained by carbonizing a phenol resin and then activating treatment.
  • the electrode mixture layer is formed by applying an active material described above, an electrode slurry prepared by combining the binder polymer described below and a solvent as necessary, onto the undercoat layer, and then naturally or by heating and drying. can do.
  • the binder polymer can be appropriately selected from known materials and used, for example, polyvinylidene fluoride (PVdF), polyvinylpyrrolidone, polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, vinylidene fluoride- Hexafluoropropylene copolymer [P (VDF-HFP)], vinylidene fluoride-trichloroethylene copolymer [P (VDF-CTFE)], polyvinyl alcohol, polyimide, ethylene-propylene-diene ternary copolymer Examples thereof include conductive polymers such as coalescence, styrene-butadiene rubber, carboxymethyl cellulose (CMC), polyacrylic acid (PAA), and polyaniline.
  • PVdF polyvinylidene fluoride
  • PVdF polyvinylidene fluoride
  • PVDF-HFP vinylidene fluoride- Hexafluor
  • the added amount of the binder polymer is preferably 0.1 to 20 parts by mass, particularly 1 to 10 parts by mass with respect to 100 parts by mass of the active material.
  • the solvent include the solvents exemplified in the above solvent for the composition, and may be appropriately selected according to the type of the binder, but NMP is preferable in the case of a water-insoluble binder such as PVdF. In the case of a water-soluble binder such as PAA, water is preferable.
  • the electrode slurry may contain a conductive material.
  • the conductive material include carbon black, ketjen black, acetylene black, carbon whisker, carbon fiber, natural graphite, artificial graphite, titanium oxide, ruthenium oxide, aluminum, nickel and the like.
  • Examples of the method for applying the electrode slurry include the same method as the method for applying the composition described above.
  • the temperature for drying by heating is arbitrary, but is preferably about 50 to 400 ° C, more preferably about 80 to 150 ° C.
  • the electrode may be pressed as necessary.
  • the press pressure is preferably 1 kN / cm or more.
  • the pressing method a generally adopted method can be used, but a die pressing method and a roll pressing method are particularly preferable.
  • the pressing pressure is not particularly limited, but is preferably 2 kN / cm or more, and more preferably 3 kN / cm or more.
  • the upper limit of the pressing pressure is preferably about 40 kN / cm, more preferably about 30 kN / cm.
  • An energy storage device includes the above-described electrode for an energy storage device, and more specifically includes at least a pair of positive and negative electrodes, a separator interposed between these electrodes, and an electrolyte. And at least one of the positive and negative electrodes is composed of the energy storage device electrode described above. Since this energy storage device is characterized by the use of the above-described electrode for energy storage device as an electrode, other device constituent members such as separators and electrolytes may be appropriately selected from known materials and used. it can. Examples of the separator include a cellulose separator and a polyolefin separator.
  • the electrolyte may be either liquid or solid, and may be either aqueous or non-aqueous.
  • the electrode for an energy storage device of the present invention is practically sufficient even when applied to a device using a non-aqueous electrolyte. Performance can be demonstrated.
  • non-aqueous electrolyte examples include a non-aqueous electrolyte obtained by dissolving an electrolyte salt in a non-aqueous organic solvent.
  • electrolyte salts include lithium salts such as lithium tetrafluoroborate, lithium hexafluorophosphate, lithium perchlorate, and lithium trifluoromethanesulfonate; tetramethylammonium hexafluorophosphate, tetraethylammonium hexafluorophosphate, tetrapropylammonium hexa Quaternary ammonium salts such as fluorophosphate, methyltriethylammonium hexafluorophosphate, tetraethylammonium tetrafluoroborate, tetraethylammonium perchlorate, lithium imides such as lithium bis (trifluoromethanesulfonyl) imide, lithium bis (fluo
  • non-aqueous organic solvent examples include alkylene carbonates such as propylene carbonate, ethylene carbonate, and butylene carbonate; dialkyl carbonates such as dimethyl carbonate, methyl ethyl carbonate, and diethyl carbonate; nitriles such as acetonitrile; and amides such as dimethylformamide. .
  • the form of the energy storage device is not particularly limited, and conventionally known various types of cells such as a cylindrical type, a flat wound square type, a laminated square type, a coin type, a flat wound laminated type, and a laminated laminate type are adopted. can do.
  • the above-described electrode for an energy storage device of the present invention may be used by punching it into a predetermined disk shape.
  • a lithium ion secondary battery one electrode is placed on a lid to which a washer and a spacer of a coin cell are welded, and a separator of the same shape impregnated with an electrolytic solution is stacked thereon.
  • the energy storage device electrode of the present invention can be overlaid with the composite material layer facing down, a case and a gasket can be placed thereon, and sealed with a coin cell caulking machine.
  • the electrode mixture layer is welded to the metal tab at the portion where the electrode mixture layer is not formed (welded part) in the electrode formed on part or the entire surface of the undercoat layer.
  • the obtained electrode structure may be used.
  • the basis weight of the undercoat layer per surface of the current collector is preferably 0.1 g / m 2 or less, more preferably 0.09 g / m 2 or less, even more preferably less than 0.05 g / m 2.
  • one or a plurality of electrodes constituting the electrode structure may be used, but generally a plurality of positive and negative electrodes are used.
  • the plurality of electrodes for forming the positive electrode are preferably alternately stacked one by one with the plurality of electrodes for forming the negative electrode, and the separator described above is interposed between the positive electrode and the negative electrode. It is preferable. Even if the metal tab is welded at the welded portion of the outermost electrode of the plurality of electrodes, the metal tab is welded with the metal tab sandwiched between the welded portions of any two adjacent electrodes among the plurality of electrodes. Also good.
  • the material of the metal tab is not particularly limited as long as it is generally used for energy storage devices.
  • metal such as nickel, aluminum, titanium, copper; stainless steel, nickel alloy, aluminum alloy
  • An alloy such as a titanium alloy or a copper alloy can be used, but in view of welding efficiency, an alloy including at least one metal selected from aluminum, copper and nickel is preferable.
  • the shape of the metal tab is preferably a foil shape, and the thickness is preferably about 0.05 to 1 mm.
  • a known method used for metal-to-metal welding can be used. Specific examples thereof include TIG welding, spot welding, laser welding, ultrasonic welding, and the like. It is preferable to join the metal tab.
  • a technique of ultrasonic welding for example, a plurality of electrodes are arranged between an anvil and a horn, a metal tab is arranged in a welded portion, and ultrasonic welding is applied to collect a plurality of electrodes. The technique of welding first and then welding a metal tab is mentioned.
  • the metal tab and the electrode are not only welded at the welded portion, but a plurality of electrodes are also ultrasonically welded to each other.
  • the pressure, frequency, output, processing time, and the like during welding are not particularly limited, and may be set as appropriate in consideration of the material used, the presence or absence of the undercoat layer, the basis weight, and the like.
  • the electrode structure produced as described above is housed in a laminate pack, and after injecting the above-described electrolyte, heat sealing is performed to obtain a laminate cell.
  • undercoat solution [Example 1-1] 4. Epocros WS-300 (made by Nippon Shokubai Co., Ltd., solid concentration 10% by weight, weight average molecular weight 1.2 ⁇ 10 5 , oxazoline group amount 7.7 mmol / g) which is an aqueous solution containing an oxazoline polymer as a dispersant. 0 g, 37.15 g of pure water and 7.35 g of 2-propanol (manufactured by Junsei Chemical Co., Ltd., reagent grade), and CNT-TC-2010 (manufactured by Toda Kogyo Co., Ltd., multilayer) CNT) 0.5 g was mixed.
  • Epocros WS-300 made by Nippon Shokubai Co., Ltd., solid concentration 10% by weight, weight average molecular weight 1.2 ⁇ 10 5 , oxazoline group amount 7.7 mmol / g
  • 2-propanol manufactured by Junsei
  • the obtained mixture was subjected to ultrasonic treatment for 30 minutes using a probe type ultrasonic irradiation device to prepare a dispersion in which CNTs were uniformly dispersed.
  • Aron A-30 Toagosei Co., Ltd., solid content concentration 31.6% by mass
  • PAA-NH 4 ammonium polyacrylate
  • PAA-NH 4 ammonium polyacrylate
  • 2-propanol manufactured by Junsei Chemical Co., Ltd., reagent special grade
  • Example 1-2 An undercoat solution was prepared in the same manner as in Example 1-1 except that CNT was changed to VGCF-X (manufactured by Showa Denko KK, multilayer CNT).
  • Example 1-3 An undercoat solution was prepared in the same manner as in Example 1-1, except that CNT was changed to C-100 (manufactured by Arkema Co., Ltd., multilayer CNT).
  • Example 1-4 An undercoat solution was prepared in the same manner as in Example 1-1 except that CNT was changed to AMC (manufactured by Ube Industries, Ltd., multilayer CNT).
  • Example 1-1 An undercoat solution was prepared in the same manner as in Example 1-1 except that CNT was changed to Baytubes (multilayer CNT manufactured by BAYER).
  • Example 1-2 An undercoat solution was prepared in the same manner as in Example 1-1 except that CNT was changed to EC600JD (manufactured by Lion Corporation, Ketjen Black).
  • Example 1-3 An undercoat solution was prepared in the same manner as in Example 1-1 except that CNT was changed to Denka Black (manufactured by Denka Co., Ltd., carbon black).
  • the average diameter of each CNT used above was measured by the following procedure. 0.5 g of CNT, 42.08 g of pure water, and 7.43 g of 2-propanol (manufactured by Junsei Chemical Co., Ltd., reagent special grade) were mixed. The obtained mixture was subjected to ultrasonic treatment for 10 minutes using a probe type ultrasonic irradiation device, and the CNT powder was pulverized in a solvent to form fine particles. Although the obtained mixture was heterogeneous, it was dropped on a grid with a carbon support film and dried at room temperature for 10 minutes. This was observed with a transmission electron microscope (TEM) at an acceleration voltage of 200 kV, and four CNTs were randomly photographed at a magnification of 70,000.
  • TEM transmission electron microscope
  • the diameter of the CNT was directly measured based on the photographed image.
  • the diameter was measured at 5 points at random for each CNT, and an average value and a standard deviation were obtained from the measured values at 20 points in total. The results are shown in Table 1. Also, images obtained by photographing CNTs are shown in FIGS.
  • Example 2-1 Production of electrode and secondary battery
  • the undercoat liquid of Example 1-1 was uniformly spread on an aluminum foil (thickness 15 ⁇ m) as a current collector with a wire bar coater (OSP-13, wet film thickness 13 ⁇ m), and then dried at 150 ° C. for 30 minutes.
  • An undercoat layer was formed to prepare an undercoat foil. 20 sheets of undercoat foil cut into 5 ⁇ 10 cm were prepared. After measuring the mass, the undercoat layer was scraped off with a paper soaked with a 1: 1 (mass ratio) mixture of 2-propanol and water. The mass of the metal foil was measured, and the basis weight of the undercoat layer calculated from the difference in mass before and after scraping was 150 mg / m 2 .
  • LiF lithium iron phosphate
  • PVdF polyvinylidene fluoride
  • NMP N-methylpyrrolidone
  • the obtained electrode slurry was spread uniformly on the previously prepared undercoat foil (wet film thickness 100 ⁇ m), then dried at 80 ° C. for 30 minutes, then at 120 ° C. for 30 minutes, and the electrode mixture layer on the undercoat layer Then, the electrode was produced by pressure bonding with a roll press.
  • Example 2 was used except that the undercoat liquids obtained in Examples 1-2 to 1-4 and Comparative Examples 1-1 to 1-3 were used. In the same manner as in Example 1, an undercoat foil and a secondary battery were produced.
  • Example 2-4 A test secondary battery was fabricated in the same manner as in Example 2-1, except that a solid aluminum foil was used as the current collector.
  • the resistance in the composition for forming a conductive thin film can be reduced.
  • the average diameter is too small, more CNT dispersant is required due to an increase in the specific surface area of the CNT, and as a result, the ratio of CNT in the composition for forming a conductive thin film is reduced, resulting in high resistance. Will be.
  • distribute in a solvent when an average diameter is too large it will be considered that it becomes difficult to prepare the composition for stable electroconductive thin film formation.

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Abstract

L'invention concerne une composition qui est destinée à former un film mince conducteur et comprend des nanotubes de carbone, un dispersant de nanotubes de carbone et un solvant, la composition étant caractérisée en ce que le diamètre moyen des nanotubes de carbone est de 5-23 nm.
PCT/JP2019/011339 2018-03-29 2019-03-19 Composition pour former un film mince conducteur WO2019188545A1 (fr)

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CN111524718A (zh) * 2020-04-11 2020-08-11 中南民族大学 一种以亲水性碳纳米管薄膜和超支化聚合物为双模板制备非对称超级电容器的方法
WO2021256487A1 (fr) * 2020-06-17 2021-12-23 三菱エンジニアリングプラスチックス株式会社 Composition de résine, corps moulé, absorbeur d'ondes électromagnétiques et procédé de mesure du taux d'absorption d'une composition de résine

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JP2016054113A (ja) * 2014-09-04 2016-04-14 日本ゼオン株式会社 二次電池電極用複合体の製造方法、二次電池電極用複合体、二次電池用電極および二次電池
WO2016194747A1 (fr) * 2015-06-04 2016-12-08 日産化学工業株式会社 Feuille de sous-couche pour électrode de dispositif de stockage d'énergie
WO2017056488A1 (fr) * 2015-09-30 2017-04-06 日本ゼオン株式会社 Composition de pâte de matériau conducteur pour électrodes de pile rechargeable, composition de suspension épaisse pour électrodes de pile rechargeable, collecteur de courant comprenant une sous-couche pour électrodes de pile rechargeable, électrode pour piles rechargeables, et pile rechargeable

Patent Citations (3)

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Publication number Priority date Publication date Assignee Title
JP2016054113A (ja) * 2014-09-04 2016-04-14 日本ゼオン株式会社 二次電池電極用複合体の製造方法、二次電池電極用複合体、二次電池用電極および二次電池
WO2016194747A1 (fr) * 2015-06-04 2016-12-08 日産化学工業株式会社 Feuille de sous-couche pour électrode de dispositif de stockage d'énergie
WO2017056488A1 (fr) * 2015-09-30 2017-04-06 日本ゼオン株式会社 Composition de pâte de matériau conducteur pour électrodes de pile rechargeable, composition de suspension épaisse pour électrodes de pile rechargeable, collecteur de courant comprenant une sous-couche pour électrodes de pile rechargeable, électrode pour piles rechargeables, et pile rechargeable

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111524718A (zh) * 2020-04-11 2020-08-11 中南民族大学 一种以亲水性碳纳米管薄膜和超支化聚合物为双模板制备非对称超级电容器的方法
CN111524718B (zh) * 2020-04-11 2021-07-13 中南民族大学 一种以亲水性碳纳米管薄膜和超支化聚合物为双模板制备非对称超级电容器的方法
WO2021256487A1 (fr) * 2020-06-17 2021-12-23 三菱エンジニアリングプラスチックス株式会社 Composition de résine, corps moulé, absorbeur d'ondes électromagnétiques et procédé de mesure du taux d'absorption d'une composition de résine

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