WO2014188896A1 - Collector and bipolar battery - Google Patents

Collector and bipolar battery Download PDF

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Publication number
WO2014188896A1
WO2014188896A1 PCT/JP2014/062562 JP2014062562W WO2014188896A1 WO 2014188896 A1 WO2014188896 A1 WO 2014188896A1 JP 2014062562 W JP2014062562 W JP 2014062562W WO 2014188896 A1 WO2014188896 A1 WO 2014188896A1
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WO
WIPO (PCT)
Prior art keywords
resin layer
current collector
conductive resin
conductive
negative electrode
Prior art date
Application number
PCT/JP2014/062562
Other languages
French (fr)
Japanese (ja)
Inventor
佳宏 古川
井上　真一
Original Assignee
日東電工株式会社
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Filing date
Publication date
Application filed by 日東電工株式会社 filed Critical 日東電工株式会社
Publication of WO2014188896A1 publication Critical patent/WO2014188896A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/668—Composites of electroconductive material and synthetic resins
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H01M10/0585—Construction or manufacture of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/029—Bipolar electrodes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to a current collector and a bipolar battery, and more particularly to a bipolar battery suitably used for a lithium ion secondary battery and a current collector provided therein.
  • a lithium ion secondary battery is mounted from the viewpoint that high energy density and high output density are required.
  • a positive electrode active material and a negative electrode active material are respectively disposed on both sides of a plurality of current collectors.
  • Bipolar batteries in which an electrolyte layer is disposed between the bodies are being studied.
  • a current collector made of a polymer material, a positive electrode electrically coupled to one surface of the current collector, and a current collector
  • a bipolar battery including an electrode composed of a negative electrode electrically coupled to the other surface of the body and an electrolyte layer disposed between the plurality of electrodes (for example, see Patent Document 1).
  • the electrolyte in the electrolyte layer may pass through the electrode and come into contact with the surface of the current collector, and may further penetrate into the current collector. In that case, a side reaction occurs on the surface and inside of the current collector, resulting in a problem that the current collector deteriorates.
  • An object of the present invention is to provide a current collector that is excellent in durability while reducing the weight of the current collector and improving the output density per unit mass, and a bipolar battery including the current collector.
  • the current collector of the present invention comprises a conductive resin layer containing a resin and a conductive material, and an insulating resin layer formed on one surface in the thickness direction of the conductive resin layer and having a thickness of 1 nm to 1 ⁇ m. Yes.
  • the insulating resin layer contains a polycarbonate resin.
  • the resin contains polyimide and / or polyamideimide.
  • the conductive material contains nickel and / or stainless steel.
  • the bipolar battery of the present invention is a bipolar battery including a plurality of electrodes spaced apart from each other, and an electrolyte layer disposed between the electrodes, wherein at least one of the plurality of electrodes is as described above.
  • the bipolar battery of the present invention is preferably used as a lithium ion secondary battery.
  • the current collector of the present invention includes a conductive resin layer containing a resin and a conductive material, the current collector can be reduced in weight and the output density per unit mass can be improved.
  • the current collector of the present invention includes an insulating resin layer formed on one surface in the thickness direction of the conductive resin layer, side reactions on one surface in the thickness direction of the conductive resin layer can be suppressed. Therefore, the current collector of the present invention is excellent in durability.
  • the bipolar battery of the present invention includes a current collector having excellent durability, it is excellent in durability.
  • FIG. 1 shows a cross-sectional view of a current collector according to an embodiment of the present invention.
  • FIG. 2 shows a cross-sectional view of one embodiment of the bipolar battery of the present invention comprising a plurality of electrodes having the current collector shown in FIG. 3 shows a partially exploded enlarged view of the charge / discharge part of the bipolar battery shown in FIG.
  • the current collector 1 includes a conductive resin layer 6 and an insulating resin layer 19 as shown in FIG.
  • the conductive resin layer 6 is formed in a substantially rectangular substantially flat plate shape.
  • the conductive resin layer 6 is formed from a conductive resin composition containing a resin and a conductive material.
  • the resin examples include a thermoplastic resin and a thermosetting resin.
  • thermoplastic resin examples include rubber resins such as polystyrene-polyisoprene-polystyrene block copolymer rubber (SIBS) and styrene-butadiene copolymer rubber (SBR), such as low density polyethylene (LDPE), high density Olefin resins such as polyethylene (HDPE), linear low density polyethylene (LLDPE), polypropylene (PP), polybutylene, for example, ethylene such as ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl alcohol copolymer Copolymers, for example, polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), acrylic polymers such as polymethyl acrylate (PMA), polymethyl methacrylate (PMMA), etc., and other polycarbonates Resin (PC), polyether nitrile (PEN), polyimide (PI), polyamide (PA), polyamideimide (PAI), polytetrafluoroethylene
  • thermoplastic resins can be used alone or in combination.
  • thermoplastic resins polyimide and polyamideimide are preferable, and polyamideimide is more preferable from the viewpoint of ion blocking properties.
  • thermosetting resin examples include epoxy resin, thermosetting polyimide, urea resin, melamine resin, unsaturated polyester resin, diallyl phthalate resin, thermosetting silicone resin, thermosetting polyurethane resin, and the like.
  • the resin is preferably a thermoplastic resin.
  • the number average molecular weight of the resin is, for example, 1 ⁇ 10 3 or more, preferably 1 ⁇ 10 4 or more, more preferably 2 ⁇ 10 4 or more, and for example, 1 ⁇ 10 6 or less, preferably 1 ⁇ 10 5 or less, more preferably 5 ⁇ 10 4 or less.
  • the number average molecular weight is measured as a conversion value based on standard polystyrene using gel permeation chromatography.
  • the glass transition point Tg of the resin is, for example, 100 ° C. or higher, preferably 200 ° C. or higher, and 500 ° C. or lower, preferably 400 ° C. or lower.
  • the glass transition point is measured by a dynamic viscoelasticity measuring device (DMA) and differential scanning calorimetry (DSC).
  • DMA dynamic viscoelasticity measuring device
  • DSC differential scanning calorimetry
  • the blending ratio of the resin is, for example, 20% by mass or more, preferably 50% by mass or more, and for example, 99% by mass or less, preferably 90% by mass or less with respect to the conductive resin composition.
  • Examples of the conductive material include metal fillers and carbon fillers.
  • metal forming the metal filler examples include copper, nickel, tin, aluminum, iron, chromium, titanium, gold, silver, platinum, niobium, and alloys thereof (for example, stainless steel).
  • metal metal carbide, metal nitride, metal oxide, etc. are also mentioned.
  • nickel and stainless steel are used, and more preferably nickel is used.
  • Examples of the carbon forming the carbon filler include graphite (graphite), carbon black (furnace black, acetylene black, ketjen black, carbon nanotube) and the like. Preferably, carbon black is used.
  • the conductive material is preferably a metal filler from the viewpoint of the durability of the current collector.
  • These conductive materials can be used alone or in combination.
  • the shape of the conductive material is not particularly limited, and examples thereof include a spherical shape, a scale shape, a flake shape, a dendritic shape, and a lump shape (indefinite shape).
  • the average value of the maximum length of the conductive material is, for example, 0.01 ⁇ m or more, and, for example, 100 ⁇ m or less, preferably 50 ⁇ m or less, more preferably 40 ⁇ m or less.
  • the blending ratio of the conductive material is, for example, 5 parts by mass or more, preferably 10 parts by mass or more, for example, 500 parts by mass or less, preferably 200 parts by mass or less, relative to 100 parts by mass of the resin. More preferably, it is 50 parts by mass or less.
  • the blending ratio of the conductive material is equal to or higher than the lower limit, the conductivity of the conductive resin layer 6 can be ensured.
  • the mixture ratio of a conductive material is below the said upper limit, the weight reduction of the conductive resin layer 6 and by extension, the weight reduction of the electrical power collector 1 can be achieved.
  • the conductive resin composition can contain known additives such as surfactants and polymer dispersants in an appropriate ratio.
  • surfactants include a cationic surfactant and an anionic surfactant.
  • the thickness of the conductive resin layer 6 is, for example, 0.01 ⁇ m or more, preferably 0.1 ⁇ m or more, and, for example, 100 ⁇ m or less, preferably 50 ⁇ m or less, more preferably 30 ⁇ m or less.
  • the current collector 1 When the thickness of the conductive resin layer 6 is equal to or more than the above lower limit, the current collector 1 can be easily handled. When the thickness of the conductive resin layer 6 is equal to or less than the above upper limit, the thickness of the current collector 1 does not become too thick, and the current collector 1 can be easily reduced in size and weight.
  • the volume resistivity of the conductive resin layer 6 is, for example, 0.01 ⁇ cm or more, and for example, 100 ⁇ cm or less, preferably 50 ⁇ cm or less, more preferably 30 ⁇ cm or less.
  • the volume resistivity is measured using a resistivity meter in accordance with JIS K 7194.
  • the insulating resin layer 19 is provided on the entire upper surface of the conductive resin layer 6.
  • the insulating resin layer 19 is formed of an insulating resin, and examples of such an insulating resin include the resins mentioned in the conductive resin layer 6.
  • a thermoplastic resin is used, and more preferably, a polycarbonate resin is used from the viewpoint of obtaining the insulating resin layer 19 as a dense film.
  • These insulating resins can be used alone or in combination.
  • the polycarbonate resin is a polymer having a carbonate bond (carbonic acid ester group) in the main chain, and the basic skeleton has the general formula [—O—R—O—CO—] n (R represents a hydrocarbon group). It is represented by
  • the polycarbonate resin is a polymer obtained by condensation polymerization of a condensation polymerizable monomer containing, for example, a dihydric alcohol and a dialkyl carbonate.
  • the polycarbonate resin is also a polymer obtained by addition polymerization of an addition polymerizable monomer containing a carbonate compound having an ethylenically unsaturated double bond, for example.
  • the polycarbonate resin is preferably a polymer obtained by addition polymerization of addition polymerizable monomers.
  • dihydric alcohol examples include diols such as ethylene glycol, propylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, and benzenediol.
  • dialkyl carbonate examples include dimethyl carbonate, diethyl carbonate, and di (n-propyl) carbonate.
  • Examples of the carbonate compound having an ethylenically unsaturated double bond include vinylene carbonate (vinylene carbonate), vinyl ethyl carbonate (vinyl ethylene carbonate), allyl ethyl carbonate (allyl ethyl carbonate), and the like.
  • vinylene carbonate is used from the viewpoint of obtaining the insulating resin layer 19 as a dense film.
  • the thickness of the insulating resin layer 19 is, for example, 1 nm or more, preferably 3 nm or more, and for example, 1 ⁇ m or less, preferably 800 nm or less. If the thickness of the insulating resin layer 19 is less than the lower limit, side reactions (described later) cannot be suppressed. Moreover, when the thickness of the insulating resin layer 19 exceeds the above upper limit, the conductivity between the insulating resin layer 19 and an active material (described later) cannot be ensured.
  • the conductive resin layer 6 is formed.
  • a conductive resin-containing solution (varnish) is prepared, and then the conductive resin-containing solution is applied on a substrate to form a coating film. , Heat.
  • the conductive resin-containing solution is obtained by blending a resin and a conductive material to prepare a conductive resin composition, and if necessary, blending a solvent.
  • the solvent examples include water and organic solvents.
  • the organic solvent include alcohols such as ethanol, esters such as ethyl acetate, ketones such as methyl ethyl ketone, and N-methyl.
  • nitrogen-containing organic solvents such as pyrrolidone. These solvents can be used alone or in combination.
  • the mixing ratio of the solvent is, for example, 30 parts by mass or more, preferably 90 parts by mass or more, and, for example, 2700 parts by mass or less, preferably 1200 parts by mass or less with respect to 100 parts by mass of the conductive resin composition. It is.
  • the substrate has a substantially flat plate shape, for example, a polyolefin such as polyethylene and polypropylene, a resin material such as a polyester such as polyethylene terephthalate and polyethylene naphthalate, a metal material such as iron, aluminum, and stainless steel, such as silicon. It is formed from a ceramic material such as glass. Preferably, it is formed from glass.
  • Examples of the method for applying the conductive resin-containing solution onto the substrate include a roll coating method, a gravure coating method, a spin coating method, and a bar coating method.
  • the heating temperature is, for example, 30 ° C. or higher, preferably 50 ° C. or higher, and for example, 450 ° C. or lower, preferably 350 ° C. or lower.
  • the heating time is, for example, 0.1 minutes or more, preferably 1 minute or more, and for example, 200 minutes or less, preferably 100 minutes or less.
  • the heating of this coating film can be carried out several times at different temperatures. For example, it is possible to perform second-stage heating in which the second-stage heating temperature and time each exceed the first-stage heating temperature and time, respectively.
  • the heating condition of the first stage is such that the temperature is, for example, 50 ° C. or higher, preferably 70 ° C. or higher, for example, less than 200 ° C., preferably less than 150 ° C., and time Is, for example, 1 minute or more, preferably 5 minutes or more, and for example, 30 minutes or less, preferably 20 minutes or less.
  • the temperature is, for example, 150 ° C. or more, preferably 250 ° C. or more, for example, 420 ° C. or less, preferably 370 ° C. or less
  • the time is, for example, 10 Minutes or more, preferably 20 minutes or more, and for example, 200 minutes or less, preferably 150 minutes or less.
  • the coating film can be dried by heating in the first stage, and the dried coating film can be cured (that is, cured) by heating in the second stage.
  • the conductive resin layer 6 is peeled off from the base material.
  • an insulating resin layer 19 is formed on the entire upper surface of the conductive resin layer 6.
  • the insulating resin layer 19 In order to form the insulating resin layer 19, an insulating resin is applied to the entire upper surface of the conductive resin layer 6.
  • the insulating resin layer 19 may be previously formed from an insulating resin on the upper surface of a base material (not shown), and then the insulating resin layer 19 may be transferred (laminated) to the upper surface of the conductive resin layer 6.
  • a monomer liquid containing a monomer such as a condensation polymerizable monomer and / or an addition polymerizable monomer is prepared, and then the monomer liquid is applied to the entire upper surface of the conductive resin layer 6. Then, a coating film is formed, and then the monomers in the coating film are reacted.
  • a monomer for example, a monomer, a polymerization initiator, and a solvent are mixed.
  • a radical generator may be mentioned.
  • a thermal polymerization initiator that decomposes by heat to generate radicals, for example, by light
  • photopolymerization initiators that decompose to generate radicals.
  • a photopolymerization initiator is used.
  • examples of the polymerization initiator include peroxides, azo compounds, dihalogen compounds, alkylphenone compounds, acylphosphine oxide compounds, and the like.
  • an alkylphenone compound is used.
  • the blending ratio of the polymerization initiator is, for example, 0.01 parts by mass or more, preferably 0.1 parts by mass or more, for example, 10 parts by mass or less, preferably 5 parts by mass with respect to 100 parts by mass of the monomer. It is below mass parts.
  • solvent examples include the organic solvents described above, and preferably alcohols. These solvents can be used alone or in combination.
  • the mixing ratio of the solvent is such that the mass ratio of the monomer to the monomer liquid is, for example, 0.01% by mass or more, preferably 0.1% by mass or more, and for example, 50% by mass or less, preferably 20% by mass. Adjust so that:
  • the monomer liquid is applied to the entire upper surface of the conductive resin layer 6 by the above-described application method. Thereby, a coating film of the monomer liquid is formed.
  • the coating film is irradiated with light such as ultraviolet rays.
  • the dose of light for example, 10 mJ / cm 2 or more, preferably at most 100 mJ / cm 2 or more, and is, for example, 10000 mJ / cm 2 or less, preferably 1000 mJ / cm 2 or less.
  • the coating film is heated.
  • the heating temperature is, for example, 50 ° C. or more, preferably 100 ° C. or more, for example, 200 ° C. or less, preferably 140 ° C. or less
  • the heating time is, for example, 10 seconds or more. It is preferably 1 minute or longer, and for example, 60 minutes or shorter, preferably 30 minutes or shorter.
  • the polymerization initiator contains a photopolymerization initiator and a thermal polymerization initiator, light irradiation and heating are used in combination with the coating film.
  • the insulating resin layer 19 is formed on the entire upper surface of the conductive resin layer 6.
  • the insulating resin layer 19 can also be formed by immersing the conductive resin layer 6 in the monomer solution and applying a potential to the conductive resin layer 6, that is, passing a current through the conductive resin layer 6.
  • the current collector 1 produced in this way can be used as the current collector 1 of various devices. Specifically, the current collector 1 can be used as the current collector 1 of the bipolar battery 7, for example. This bipolar battery 7 can be used as a lithium ion secondary battery.
  • bipolar battery 7 including the current collector 1 shown in FIG. 1 will be described with reference to FIGS.
  • the bipolar battery 7 is a bipolar lithium ion secondary battery, and includes a charging / discharging unit 8 in which a charging / discharging reaction proceeds, and an exterior material 9 that houses the charging / discharging unit 8.
  • the charging / discharging unit 8 is formed in a substantially flat plate shape, and includes a plurality of electrodes 10 provided at intervals from each other, and an electrolyte layer 11 disposed between the electrodes 10.
  • a plurality of electrodes 10 are stacked in the thickness direction, and are formed between two end electrodes 13 formed at one end in the thickness direction (uppermost side) and the other end in the thickness direction (lowermost side). And a plurality of main electrodes 12 arranged.
  • Each of the main electrodes 12 is a bipolar electrode. Specifically, as shown in FIG. 3, a current collector 1 and a positive electrode 14 laminated on the upper surface (one surface in the thickness direction) of the current collector 1 And the negative electrode 15 laminated on the lower surface (the other surface in the thickness direction) of the current collector 1.
  • the current collector 1 includes a conductive resin layer 6 and an insulating resin layer 19 formed on the entire lower surface of the conductive resin layer 6.
  • the positive electrode 14 is a pattern that exposes an end of the conductive resin layer 6 (a peripheral edge in the plane direction perpendicular to the thickness direction), and is formed so as to be in contact with the upper surface of the conductive resin layer 6 over the entire lower surface of the positive electrode 14. Yes.
  • the positive electrode 14 is made of a positive electrode material containing a positive electrode active material as an essential component and a binder as an optional component.
  • the positive electrode active material is not particularly limited as long as it is a positive electrode active material used in a bipolar lithium ion secondary battery, and examples thereof include a lithium compound.
  • the lithium compound include lithium-transition metal composite oxides (lithium-based composite oxides) such as LiCoO 2 , LiNiO 2 , and Li (Ni—Co—Mn) O 2, such as lithium-transition metal phosphate compounds
  • a lithium-transition metal sulfate compound can be used.
  • the positive electrode active material can be used alone or in combination.
  • the positive electrode active material is preferably a lithium-transition metal composite oxide from the viewpoint of capacity and output characteristics.
  • the binder is not particularly limited.
  • the binder can be used alone or in combination.
  • PVdF polyimide
  • styrene / butadiene rubber CMC
  • polypropylene PTFE
  • polyacrylonitrile polyamide
  • the blending ratio of the binder is, for example, 0.5 parts by mass or more, preferably 1 part by mass or more, for example, 15 parts by mass or less, preferably 10 parts by mass with respect to 100 parts by mass of the positive electrode material. Or less.
  • additives such as a conductive additive, an electrolyte salt, and an ion conductive polymer can be added to the positive electrode material at an appropriate ratio.
  • Examples of the conductive aid include the carbon-based filler described above.
  • electrolyte salt examples include lithium salts such as Li (C 2 F 5 SO 2 ) 2 N, LiPF 6 , LiBF 4 , LiClO 4 , LiAsF 6 , and LiCF 3 SO 3 .
  • Examples of the ion conductive polymer include polyalkylene oxides such as polyethylene oxide (PEO) and polypropylene oxide (PPO).
  • polyalkylene oxides such as polyethylene oxide (PEO) and polypropylene oxide (PPO).
  • the above-described positive electrode material is blended in a solvent such as N-methylpyrrolidone (NMP), dimethyl carbonate (DMC), or acetonitrile at an appropriate ratio. To prepare a slurry. Next, the slurry is applied to the upper surface of the conductive resin layer 6, and then the coating film is dried by heating.
  • NMP N-methylpyrrolidone
  • DMC dimethyl carbonate
  • acetonitrile acetonitrile
  • the positive electrode 14 is formed on the upper surface of the conductive resin layer 6 in the pattern described above.
  • the negative electrode 15 is formed so as to be in contact with the lower surface of the insulating resin layer 19 over the entire upper surface of the negative electrode 15 so as to expose the end portion (peripheral end portion in the plane direction) of the insulating resin layer 19. Is formed so as to be the same pattern as the pattern of the positive electrode 14 when projected in the thickness direction. Thereby, the insulating resin layer 19 is interposed between the negative electrode 15 and the conductive resin layer 6.
  • the negative electrode 15 is formed of a negative electrode material containing a negative electrode active material as an essential component and a binder as an optional component.
  • the negative electrode active material is not particularly limited as long as it is a negative electrode active material used in a bipolar lithium ion secondary battery.
  • carbon active materials such as graphite, soft carbon, and hard carbon, lithium-transition metal composite oxides ( For example, Li 4 Ti 5 O 12) , metal active material, and lithium alloy-based negative electrode active material.
  • the negative electrode active material can be used alone or in combination.
  • the negative electrode active material is preferably a carbon active material or a lithium-transition metal composite oxide from the viewpoint of capacity and output characteristics.
  • binder examples include the binder exemplified in the positive electrode material.
  • the blending ratio of the binder is the same as above.
  • the additive exemplified in the positive electrode material can be added to the negative electrode material at an appropriate ratio.
  • the above-described negative electrode material is blended with the above-described solvent in an appropriate ratio to prepare a slurry.
  • the slurry is applied to the lower surface of the insulating resin layer 19, and then the coating film is dried by heating.
  • the negative electrode 15 is formed on the lower surface of the insulating resin layer 19 with the above-described pattern.
  • the plurality of main electrodes 12 are stacked via the plurality of electrolyte layers 11 in the thickness direction. That is, the electrolyte layer 11 is interposed between the plurality of main electrodes 12 adjacent to each other in the thickness direction, and more specifically, the main electrodes 12 and the electrolyte layers 11 are sequentially stacked alternately in the thickness direction. .
  • the positive electrode 14 of one main electrode 12A and the negative electrode 15 of another main electrode 12B adjacent to the one main electrode 12A are disposed to face each other in the thickness direction, and the electrolyte layer 11 is interposed between them.
  • the main electrodes 12 and the electrolyte layers 11 are alternately stacked so as to be sandwiched between them.
  • the electrolyte layer 11 has a substantially flat plate shape and is configured to hold the electrolyte between adjacent main electrodes 12.
  • electrolyte examples include a liquid electrolyte and a solid electrolyte.
  • the liquid electrolyte has a form in which the supporting salt is dissolved in an organic solvent.
  • the organic solvent include carbonate compounds such as ethylene carbonate (EC) and propylene carbonate (PC).
  • the supporting salt include a lithium salt.
  • examples of the solid electrolyte include a gel electrolyte containing an electrolytic solution and an intrinsic solid electrolyte not containing an electrolytic solution.
  • the gel electrolyte is formed by dispersing the above liquid electrolyte in a matrix polymer made of the above ion conductive polymer.
  • the electrolyte layer 11 when the electrolyte layer 11 is formed from a liquid electrolyte or a gel electrolyte, the electrolyte layer 11 can be provided with a separator.
  • the separator include a microporous film made of polyolefin such as polyethylene and polypropylene.
  • the intrinsic solid electrolyte is prepared by dissolving a supporting salt in the above matrix polymer, and does not contain an organic solvent (such as a plasticizer).
  • the positive electrode 14 (specifically, the positive electrode 14 of one main electrode 12A), the electrolyte layer 11, and the negative electrode 15 (the negative electrode 15 sandwiching the positive electrode 14 and the electrolyte layer 11, specifically, the other main electrode 12B).
  • the negative electrode 15 constitutes a single cell layer 23.
  • the bipolar battery 7 is formed by laminating a plurality of single battery layers 23.
  • the current collector 1 is interposed between the unit cell layers 23 adjacent to each other.
  • each of the two terminal electrodes 13 includes a current collector 1 and either a positive electrode 14 or a negative electrode 15 formed on the upper surface or the lower surface of the current collector 1.
  • the terminal electrode 13a on the positive electrode side includes the current collector 1 and the positive electrode 14 laminated on the upper surface thereof, but does not include the negative electrode 15.
  • a positive electrode current collector plate 16 is provided on the lower surface of the terminal electrode 13a on the positive electrode side.
  • the positive electrode current collector plate 16 is integrally provided with a covering portion that covers the lower surface of the terminal electrode 13a on the positive electrode side, and an extending portion that extends from the covering portion in one plane direction (right direction in FIG. 2). Yes.
  • the terminal electrode 13b on the negative electrode side includes the current collector 1 and the negative electrode 15 stacked on the lower surface thereof, but does not include the positive electrode 14.
  • a negative electrode current collector plate 17 is provided on the upper surface of the terminal electrode 13b on the negative electrode side.
  • the negative electrode current collector plate 17 is integrally provided with a covering portion that covers the upper surface of the terminal electrode 13b on the negative electrode side and an extending portion that extends from the covering portion in the other direction of the surface (left direction in FIG. 2). Yes.
  • Examples of the exterior material 9 include a metal case or a bag-like laminate film.
  • a laminate film is used from the viewpoint of achieving high output and excellent cooling performance and mounting the bipolar battery 7 on the EV and / or HEV.
  • Examples of the laminate film include a laminate film having a three-layer structure formed by laminating PP, aluminum, and nylon (polyamide) in this order.
  • the exterior material 9 seals the charge / discharge part 8. On the other hand, the exterior material 9 exposes the free end portions of the extending portions of the positive electrode current collector plate 16 and the negative electrode current collector plate 17, respectively.
  • Such a bipolar battery 7 is mounted on a vehicle such as EV or HEV and used as a driving power source.
  • the bipolar battery 7 can be used as a mounting power source such as an uninterruptible power supply.
  • this electrical power collector 1 is provided with the conductive resin layer 6 containing resin and an electroconductive material, the weight reduction of the electrical power collector 1 can be achieved and the output density per unit mass can be improved.
  • the current collector 1 includes the insulating resin layer 19 formed on one surface in the thickness direction of the conductive resin layer 6, side reactions on one surface in the thickness direction of the conductive resin layer 6 can be suppressed.
  • the electrolyte layer 11 is a liquid electrolyte, if the liquid electrolyte passes through the negative electrode 15 and comes into contact with the current collector 1, a side reaction may occur.
  • the side reaction is a reaction other than the main reaction between the negative electrode active material that brings about the charging action and the electrolyte of the electrolyte layer 11.
  • the bipolar battery 7 is a bipolar lithium ion secondary battery, the current collector 1 And decomposition of the electrolyte of the electrolyte layer 11. This side reaction needs to be suppressed as much as possible because the current collector 1 and the electrolyte layer 11 deteriorate.
  • the insulating resin layer 19 suppresses the side reaction described above, the current density of the current flowing between the current collector 1 and the electrolyte of the electrolyte layer 11 can be reduced. Therefore, the durability of the current collector 1 is improved by the insulating resin layer 19.
  • the insulating resin layer 19 includes a polycarbonate resin
  • the insulating resin layer 19 is obtained as a dense film, and the electrolyte of the electrolyte layer 11 is transmitted through the insulating resin layer 19. Can be suppressed. Therefore, the amount of the electrolyte of the electrolyte layer 11 that contacts the conductive resin layer 6 can be reduced, and side reactions on the surface and inside of the conductive resin layer 6 of the current collector 1 can be suppressed. As a result, the deterioration of the current collector 1 and the electrolyte layer 11 can be suppressed, and the durability of the current collector 1 is improved.
  • the conductive resin layer 6 when the resin contains polyimide and / or polyamideimide, the conductive resin layer 6 exhibits good ion blocking properties. Therefore, permeation of electrolyte ions of the electrolyte layer 11 to the conductive resin layer 6 can be blocked.
  • the corrosion resistance of the current collector 1 is improved, so that the durability of the current collector 1 can be improved. it can.
  • the bipolar battery 7 since the bipolar battery 7 includes the current collector 1 having excellent durability, the bipolar battery 7 has excellent durability.
  • the bipolar battery 7 can be suitably used as a lithium ion secondary battery.
  • the insulating resin layer 19 is formed on the entire upper surface of the conductive resin layer 6.
  • the insulating resin layer 19 It can also be provided on the lower surface.
  • Example 1 (Formation of insulating resin layer) A vinylene carbonate 0.4 mass% ethanol solution (monomer solution) was prepared, and then the ethanol solution was applied to the entire upper surface of the conductive resin layer produced by the method described in Production Example 1 to form a coating film. By irradiating the coating film with ultraviolet rays at 600 mJ / cm 2 , an insulating resin layer having a thickness of 15 nm was formed on the entire upper surface of the conductive resin layer. Thereby, a current collector provided with a conductive resin layer and an insulating resin layer was obtained (see FIG. 1).
  • Example 2 An insulating resin layer having a thickness of 18 nm is formed on the entire upper surface of the conductive resin layer in the same manner as in Example 1 except that an ethanol solution of 10% by weight of vinylene carbonate is used instead of the ethanol solution of 0.4% by weight of vinylene carbonate. And a current collector provided with a conductive resin layer and an insulating resin layer was obtained (see FIG. 1).
  • the conductive resin layer manufactured by the method described in Preparation Example 1 without using an insulating resin layer was used as a current collector.
  • the volume resistivity of the conductive resin layer was determined using a resistivity meter (Loresta MCP-T360, manufactured by Mitsubishi Chemical Corporation) in accordance with JIS K 7194.
  • the conductivity of the conductive resin layer was evaluated as follows. ⁇ : Volume resistivity is 100 ⁇ cm or less ⁇ : Volume resistivity exceeds 100 ⁇ cm (measurement of current density of current collector in negative electrode)
  • the current density of the flowing current was measured in the negative electrode using a three-electrode cell (manufactured by Hosen). Specifically, the current density was measured 5 minutes after the start of voltage application at a constant voltage of 5 mV.
  • the current collector is used for a lithium ion secondary battery.

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Abstract

This collector is provided with: a conductive resin layer that contains a resin and a conductive material; and an insulating resin layer that is formed on one surface of the conductive resin layer in the thickness direction and has a thickness of from 1 nm to 1 μm (inclusive).

Description

集電体およびバイポーラ電池Current collector and bipolar battery
　本発明は、集電体およびバイポーラ電池、詳しくは、リチウムイオン二次電池に好適に使用されるバイポーラ電池およびそれに備えられる集電体に関する。 The present invention relates to a current collector and a bipolar battery, and more particularly to a bipolar battery suitably used for a lithium ion secondary battery and a current collector provided therein.
　電気自動車（ＥＶ）やハイブリッド電気自動車（ＨＥＶ）には、高いエネルギー密度および高い出力密度が要求される観点から、リチウムイオン二次電池が搭載されている。 In the electric vehicle (EV) and the hybrid electric vehicle (HEV), a lithium ion secondary battery is mounted from the viewpoint that high energy density and high output density are required.
　リチウムイオン二次電池において、より一層高いエネルギー密度およびより一層高い出力密度を達成すべく、複数の集電体のそれぞれの両側に、正極活物質と負極活物質とがそれぞれ配置され、各集電体間に電解質層が配置されたバイポーラ電池が検討されている。 In a lithium ion secondary battery, in order to achieve a higher energy density and a higher output density, a positive electrode active material and a negative electrode active material are respectively disposed on both sides of a plurality of current collectors. Bipolar batteries in which an electrolyte layer is disposed between the bodies are being studied.
　ここで、二次電池では、正極活物質および負極活物質のそれぞれで反応が生じることにより、電流が集電体に流れ、放電される。一方、外部から集電体に電流を流すことにより、正極活物質および負極活物質のそれぞれで反応が生じて、充電される。 Here, in the secondary battery, when a reaction occurs in each of the positive electrode active material and the negative electrode active material, a current flows through the current collector and is discharged. On the other hand, by causing a current to flow from the outside to the current collector, a reaction occurs in each of the positive electrode active material and the negative electrode active material, and charging is performed.
　近年、バイポーラ電池を軽量化して、単位質量当たりの出力密度を向上させるべく、例えば、高分子材料からなる集電体、集電体の一方の面に電気的に結合した正極、および、集電体の他方の面に電気的に結合した負極からなる電極と、複数の電極の間に配置された電解質層とからなるバイポーラ電池が提案されている（例えば、特許文献１参照。）。 In recent years, in order to reduce the weight of a bipolar battery and improve the output density per unit mass, for example, a current collector made of a polymer material, a positive electrode electrically coupled to one surface of the current collector, and a current collector There has been proposed a bipolar battery including an electrode composed of a negative electrode electrically coupled to the other surface of the body and an electrolyte layer disposed between the plurality of electrodes (for example, see Patent Document 1).
特開２００６－１９０６４９号公報JP 2006-190649 A
　しかるに、特許文献１で提案されるバイポーラ電池では、電解質層の電解質が、電極を透過して、集電体の表面と接触し、さらには、集電体の内部に浸入する場合がある。その場合には、集電体の表面および内部において、副反応が生じ、これに起因して、集電体が劣化するという不具合を生じる。 However, in the bipolar battery proposed in Patent Document 1, the electrolyte in the electrolyte layer may pass through the electrode and come into contact with the surface of the current collector, and may further penetrate into the current collector. In that case, a side reaction occurs on the surface and inside of the current collector, resulting in a problem that the current collector deteriorates.
　本発明の目的は、集電体の軽量化を図り、単位質量当たりの出力密度を向上させながら、耐久性に優れる集電体およびそれを備えるバイポーラ電池を提供することにある。 An object of the present invention is to provide a current collector that is excellent in durability while reducing the weight of the current collector and improving the output density per unit mass, and a bipolar battery including the current collector.
　本発明の集電体は、樹脂および導電性材料を含む導電樹脂層と、導電樹脂層の厚み方向一方面に形成され、厚みが１ｎｍ以上１μｍ以下である絶縁樹脂層とを備えることを特徴としている。 The current collector of the present invention comprises a conductive resin layer containing a resin and a conductive material, and an insulating resin layer formed on one surface in the thickness direction of the conductive resin layer and having a thickness of 1 nm to 1 μm. Yes.
　また、本発明の集電体では、前記絶縁樹脂層が、ポリカーボネート樹脂を含むことが好適である。 In the current collector of the present invention, it is preferable that the insulating resin layer contains a polycarbonate resin.
　また、本発明の集電体では、前記樹脂が、ポリイミドおよび／またはポリアミドイミドを含むことが好適である。 In the current collector of the present invention, it is preferable that the resin contains polyimide and / or polyamideimide.
　また、本発明の集電体では、前記導電性材料が、ニッケルおよび／またはステンレスを含むことが好適である。 In the current collector of the present invention, it is preferable that the conductive material contains nickel and / or stainless steel.
　また、本発明のバイポーラ電池は、互いに間隔を隔てて複数設けられる電極と、各前記電極間に配置される電解質層とを備えるバイポーラ電池であり、前記複数の電極の少なくとも一つは、上記した集電体と、集電体の厚み方向一方面に積層される正極と、前記集電体の厚み方向他方面に積層される負極とを備え、前記集電体の絶縁樹脂層が、前記負極と前記導電樹脂層との間に介在されていることを特徴としている。 The bipolar battery of the present invention is a bipolar battery including a plurality of electrodes spaced apart from each other, and an electrolyte layer disposed between the electrodes, wherein at least one of the plurality of electrodes is as described above. A current collector, a positive electrode laminated on one surface in the thickness direction of the current collector, and a negative electrode laminated on the other surface in the thickness direction of the current collector, wherein the insulating resin layer of the current collector is the negative electrode And the conductive resin layer.
　また、本発明のバイポーラ電池は、リチウムイオン二次電池として用いられることが好適である。 The bipolar battery of the present invention is preferably used as a lithium ion secondary battery.
　本発明の集電体は、樹脂および導電性材料を含む導電樹脂層を備えるので、集電体の軽量化を図り、単位質量当たりの出力密度を向上することができる。 Since the current collector of the present invention includes a conductive resin layer containing a resin and a conductive material, the current collector can be reduced in weight and the output density per unit mass can be improved.
　また、本発明の集電体は、導電樹脂層の厚み方向一方面に形成される絶縁樹脂層を備えるので、導電樹脂層の厚み方向一方面での副反応を抑制することができる。そのため、本発明の集電体は、耐久性に優れる。 Moreover, since the current collector of the present invention includes an insulating resin layer formed on one surface in the thickness direction of the conductive resin layer, side reactions on one surface in the thickness direction of the conductive resin layer can be suppressed. Therefore, the current collector of the present invention is excellent in durability.
　また、本発明のバイポーラ電池は、耐久性に優れる集電体を備えるので、耐久性に優れる。 Moreover, since the bipolar battery of the present invention includes a current collector having excellent durability, it is excellent in durability.
図１は、本発明の一実施形態である集電体の断面図を示す。FIG. 1 shows a cross-sectional view of a current collector according to an embodiment of the present invention. 図２は、図１に示す集電体を有する電極を複数備える、本発明のバイポーラ電池の一実施形態の断面図を示す。FIG. 2 shows a cross-sectional view of one embodiment of the bipolar battery of the present invention comprising a plurality of electrodes having the current collector shown in FIG. 図３は、図２に示すバイポーラ電池の充放電部の一部分解拡大図を示す。3 shows a partially exploded enlarged view of the charge / discharge part of the bipolar battery shown in FIG.
　本発明の一実施形態である集電体１は、図１に示すように、導電樹脂層６と、絶縁樹脂層１９とを備えている。 The current collector 1 according to an embodiment of the present invention includes a conductive resin layer 6 and an insulating resin layer 19 as shown in FIG.
　導電樹脂層６は、略矩形の略平板状に形成されている。 The conductive resin layer 6 is formed in a substantially rectangular substantially flat plate shape.
　導電樹脂層６は、樹脂および導電性材料を含有する導電樹脂組成物から形成されている。 The conductive resin layer 6 is formed from a conductive resin composition containing a resin and a conductive material.
　樹脂としては、例えば、熱可塑性樹脂および熱硬化性樹脂などが挙げられる。 Examples of the resin include a thermoplastic resin and a thermosetting resin.
　熱可塑性樹脂としては、例えば、ポリスチレン－ポリイソプレン－ポリスチレンブロック共重合体ゴム（ＳＩＢＳ）、スチレン－ブタジエン共重合体ゴム（ＳＢＲ）などのゴム系樹脂、例えば、低密度ポリエチレン（ＬＤＰＥ）、高密度ポリエチレン（ＨＤＰＥ）、直鎖状低密度ポリエチレン（ＬＬＤＰＥ）、ポリプロピレン（ＰＰ）、ポリブチレンなどのオレフィン系樹脂、例えば、エチレン－酢酸ビニル共重合体（ＥＶＡ）、エチレン－ビニルアルコール共重合体などのエチレン共重合体、例えば、ポリエチレンテレフタレート（ＰＥＴ）、ポリエチレンナフタレート（ＰＥＮ）などのポリエステル、例えば、ポリメチルアクリレート（ＰＭＡ）、ポリメチルメタクリレート（ＰＭＭＡ）などのアクリル系重合体、その他、ポリカーボネート樹脂（ＰＣ）、ポリエーテルニトリル（ＰＥＮ）、ポリイミド（ＰＩ）、ポリアミド（ＰＡ）、ポリアミドイミド（ＰＡＩ）、ポリテトラフルオロエチレン（ＰＴＦＥ）、ポリアクリロニトリル（ＰＡＮ）、ポリ塩化ビニル（ＰＶＣ）、ポリフッ化ビニリデン（ＰＶｄＦ）、熱可塑性シリコーン樹脂などが挙げられる。 Examples of the thermoplastic resin include rubber resins such as polystyrene-polyisoprene-polystyrene block copolymer rubber (SIBS) and styrene-butadiene copolymer rubber (SBR), such as low density polyethylene (LDPE), high density Olefin resins such as polyethylene (HDPE), linear low density polyethylene (LLDPE), polypropylene (PP), polybutylene, for example, ethylene such as ethylene-vinyl acetate copolymer (EVA), ethylene-vinyl alcohol copolymer Copolymers, for example, polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), acrylic polymers such as polymethyl acrylate (PMA), polymethyl methacrylate (PMMA), etc., and other polycarbonates Resin (PC), polyether nitrile (PEN), polyimide (PI), polyamide (PA), polyamideimide (PAI), polytetrafluoroethylene (PTFE), polyacrylonitrile (PAN), polyvinyl chloride (PVC) , Polyvinylidene fluoride (PVdF), thermoplastic silicone resin, and the like.
　これら熱可塑性樹脂は、単独使用または併用することができる。 These thermoplastic resins can be used alone or in combination.
　これら熱可塑性樹脂の中でも、好ましくは、イオン遮断性の観点から、ポリイミド、ポリアミドイミド、より好ましくは、ポリアミドイミドが挙げられる。 Among these thermoplastic resins, polyimide and polyamideimide are preferable, and polyamideimide is more preferable from the viewpoint of ion blocking properties.
　熱硬化性樹脂としては、例えば、エポキシ樹脂、熱硬化性ポリイミド、ユリア樹脂、メラミン樹脂、不飽和ポリエステル樹脂、ジアリルフタレート樹脂、熱硬化性シリコーン樹脂、熱硬化性ポリウレタン樹脂などが挙げられる。 Examples of the thermosetting resin include epoxy resin, thermosetting polyimide, urea resin, melamine resin, unsaturated polyester resin, diallyl phthalate resin, thermosetting silicone resin, thermosetting polyurethane resin, and the like.
　樹脂として、好ましくは、熱可塑性樹脂が挙げられる。 The resin is preferably a thermoplastic resin.
　これら樹脂は、単独使用または併用することができる。 These resins can be used alone or in combination.
　樹脂の数平均分子量は、例えば、１×１０３以上、好ましくは、１×１０４以上、より好ましくは、２×１０４以上であり、また、例えば、１×１０６以下、好ましくは、１×１０５以下、より好ましくは、５×１０４以下である。なお、数平均分子量は、ゲル透過クロマトグラフィーを用いて標準ポリスチレン基準の換算値として測定される。 The number average molecular weight of the resin is, for example, 1 × 10 3 or more, preferably 1 × 10 4 or more, more preferably 2 × 10 4 or more, and for example, 1 × 10 6 or less, preferably 1 × 10 5 or less, more preferably 5 × 10 4 or less. The number average molecular weight is measured as a conversion value based on standard polystyrene using gel permeation chromatography.
　樹脂のガラス転移点Ｔｇは、例えば、１００℃以上、好ましくは、２００℃以上であり、また、５００℃以下、好ましくは、４００℃以下である。ガラス転移点は、動的粘弾性測定装置（ＤＭＡ）および示差走査熱量測定（ＤＳＣ）によって測定される。 The glass transition point Tg of the resin is, for example, 100 ° C. or higher, preferably 200 ° C. or higher, and 500 ° C. or lower, preferably 400 ° C. or lower. The glass transition point is measured by a dynamic viscoelasticity measuring device (DMA) and differential scanning calorimetry (DSC).
　樹脂の配合割合は、導電樹脂組成物に対して、例えば、２０質量％以上、好ましくは、５０質量％以上であり、また、例えば、９９質量％以下、好ましくは、９０質量％以下である。 The blending ratio of the resin is, for example, 20% by mass or more, preferably 50% by mass or more, and for example, 99% by mass or less, preferably 90% by mass or less with respect to the conductive resin composition.
　導電性材料としては、例えば、金属系フィラー、炭素系フィラーなどが挙げられる。 Examples of the conductive material include metal fillers and carbon fillers.
　金属系フィラーを形成する金属としては、例えば、銅、ニッケル、スズ、アルミニウム、鉄、クロム、チタン、金、銀、白金、ニオブ、これらの合金（例えば、ステンレスなど）などが挙げられる。また、上記した金属の金属炭化物、金属窒化物、金属酸化物なども挙げられる。好ましくは、ニッケル、ステンレス、より好ましくは、ニッケルが挙げられる。 Examples of the metal forming the metal filler include copper, nickel, tin, aluminum, iron, chromium, titanium, gold, silver, platinum, niobium, and alloys thereof (for example, stainless steel). Moreover, the above-mentioned metal metal carbide, metal nitride, metal oxide, etc. are also mentioned. Preferably, nickel and stainless steel are used, and more preferably nickel is used.
　炭素系フィラーを形成する炭素としては、例えば、黒鉛（グラファイト）、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、ケッチェンブラック、カーボンナノチューブ）などが挙げられる。好ましくは、カーボンブラックが挙げられる。 Examples of the carbon forming the carbon filler include graphite (graphite), carbon black (furnace black, acetylene black, ketjen black, carbon nanotube) and the like. Preferably, carbon black is used.
　導電性材料としては、集電体の耐久性の観点から、好ましくは、金属系フィラーが挙げられる。 The conductive material is preferably a metal filler from the viewpoint of the durability of the current collector.
　これら導電性材料は、単独使用または併用することができる。 These conductive materials can be used alone or in combination.
　導電性材料の形状は特に限定されず、例えば、球状、鱗状、薄片状、樹枝状、塊状（不定形）などが挙げられる。また、導電性材料の最大長さの平均値（球状の場合には、平均粒子径）は、例えば、０．０１μｍ以上であり、また、例えば、１００μｍ以下、好ましくは、５０μｍ以下、より好ましくは、４０μｍ以下である。 The shape of the conductive material is not particularly limited, and examples thereof include a spherical shape, a scale shape, a flake shape, a dendritic shape, and a lump shape (indefinite shape). The average value of the maximum length of the conductive material (in the case of a sphere, the average particle diameter) is, for example, 0.01 μm or more, and, for example, 100 μm or less, preferably 50 μm or less, more preferably 40 μm or less.
　導電性材料の配合割合は、樹脂１００質量部に対して、例えば、５質量部以上、好ましくは、１０質量部以上であり、また、例えば、５００質量部以下、好ましくは、２００質量部以下、より好ましくは、５０質量部以下である。導電性材料の配合割合が上記下限以上の場合には、導電樹脂層６の導電性を確保できる。また、導電性材料の配合割合が上記上限以下の場合には、導電樹脂層６の軽量化、ひいては、集電体１の軽量化を図ることができる。 The blending ratio of the conductive material is, for example, 5 parts by mass or more, preferably 10 parts by mass or more, for example, 500 parts by mass or less, preferably 200 parts by mass or less, relative to 100 parts by mass of the resin. More preferably, it is 50 parts by mass or less. When the blending ratio of the conductive material is equal to or higher than the lower limit, the conductivity of the conductive resin layer 6 can be ensured. Moreover, when the mixture ratio of a conductive material is below the said upper limit, the weight reduction of the conductive resin layer 6 and by extension, the weight reduction of the electrical power collector 1 can be achieved.
　導電樹脂組成物は、上記成分以外に、例えば、界面活性剤、高分子型分散剤などの公知の添加剤を適宜の割合で含有することができる。界面活性剤としては、例えば、カチオン性界面活性剤、アニオン性界面活性剤などが挙げられる。 In addition to the above components, the conductive resin composition can contain known additives such as surfactants and polymer dispersants in an appropriate ratio. Examples of the surfactant include a cationic surfactant and an anionic surfactant.
　導電樹脂層６の厚みは、例えば、０．０１μｍ以上、好ましくは、０．１μｍ以上であり、また、例えば、１００μｍ以下、好ましくは、５０μｍ以下、より好ましくは、３０μｍ以下である。 The thickness of the conductive resin layer 6 is, for example, 0.01 μm or more, preferably 0.1 μm or more, and, for example, 100 μm or less, preferably 50 μm or less, more preferably 30 μm or less.
　導電樹脂層６の厚みが、上記下限以上の場合には、集電体１の取り扱いが容易となる。また、導電樹脂層６の厚みが、上記上限以下の場合には、集電体１の厚みが厚くなりすぎず、集電体１の小型化および軽量化の実現が容易となる。 When the thickness of the conductive resin layer 6 is equal to or more than the above lower limit, the current collector 1 can be easily handled. When the thickness of the conductive resin layer 6 is equal to or less than the above upper limit, the thickness of the current collector 1 does not become too thick, and the current collector 1 can be easily reduced in size and weight.
　導電樹脂層６の体積抵抗率は、例えば、０．０１Ωｃｍ以上であり、また、例えば、１００Ωｃｍ以下、好ましくは、５０Ωｃｍ以下、より好ましくは、３０Ωｃｍ以下である。なお、体積抵抗率は、ＪＩＳ　Ｋ　７１９４に準拠して、抵抗率計を用いて測定される。 The volume resistivity of the conductive resin layer 6 is, for example, 0.01 Ωcm or more, and for example, 100 Ωcm or less, preferably 50 Ωcm or less, more preferably 30 Ωcm or less. The volume resistivity is measured using a resistivity meter in accordance with JIS K 7194.
　絶縁樹脂層１９は、導電樹脂層６の上面全面に設けられている。 The insulating resin layer 19 is provided on the entire upper surface of the conductive resin layer 6.
　絶縁樹脂層１９は、絶縁樹脂から形成されており、そのような絶縁樹脂としては、例えば、導電樹脂層６で挙げた樹脂などが挙げられる。好ましくは、熱可塑性樹脂が挙げられ、より好ましくは、絶縁樹脂層１９を緻密な皮膜として得る観点から、ポリカーボネート樹脂が挙げられる。 The insulating resin layer 19 is formed of an insulating resin, and examples of such an insulating resin include the resins mentioned in the conductive resin layer 6. Preferably, a thermoplastic resin is used, and more preferably, a polycarbonate resin is used from the viewpoint of obtaining the insulating resin layer 19 as a dense film.
　これら絶縁樹脂は、単独使用または併用することができる。 These insulating resins can be used alone or in combination.
　ポリカーボネート樹脂は、主鎖にカーボネート結合（炭酸エステル基）を有する重合体であり、基本骨格は、一般式〔－Ｏ－Ｒ－Ｏ－ＣＯ－〕ｎ（Ｒは、炭化水素基を表す。）で表される。 The polycarbonate resin is a polymer having a carbonate bond (carbonic acid ester group) in the main chain, and the basic skeleton has the general formula [—O—R—O—CO—] n (R represents a hydrocarbon group). It is represented by
　ポリカーボネート樹脂は、例えば、２価アルコールと、ジアルキルカーボネートとを含有する縮合重合可能モノマーの縮合重合によって得られる重合体である。また、ポリカーボネート樹脂は、例えば、エチレン性不飽和二重結合を有するカーボネート化合物を含有する付加重合可能モノマーの付加重合によって得られる重合体でもある。ポリカーボネート樹脂は、好ましくは、付加重合可能モノマーの付加重合によって得られる重合体である。 The polycarbonate resin is a polymer obtained by condensation polymerization of a condensation polymerizable monomer containing, for example, a dihydric alcohol and a dialkyl carbonate. The polycarbonate resin is also a polymer obtained by addition polymerization of an addition polymerizable monomer containing a carbonate compound having an ethylenically unsaturated double bond, for example. The polycarbonate resin is preferably a polymer obtained by addition polymerization of addition polymerizable monomers.
　２価アルコールとしては、例えば、エチレングリコール、プロピレングリコール、ジエチレングリコール、１，３－プロパンジオール、１，４－ブタンジオール、ベンゼンジオールなどのジオール類などが挙げられる。 Examples of the dihydric alcohol include diols such as ethylene glycol, propylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, and benzenediol.
　ジアルキルカーボネートとしては、例えば、ジメチルカーボネート、ジエチルカーボネート、ジ（ｎ－プロピル）カーボネートなどが挙げられる。 Examples of the dialkyl carbonate include dimethyl carbonate, diethyl carbonate, and di (n-propyl) carbonate.
　エチレン性不飽和二重結合を有するカーボネート化合物としては、例えば、ビニレンカーボネート（炭酸ビニレン）、ビニルエチルカーボネート（炭酸ビニルエチレン）、アリルエチルカルボナート（炭酸アリルエチル）などが挙げられる。好ましくは、絶縁樹脂層１９を緻密な皮膜として得る観点から、ビニレンカーボネートが挙げられる。 Examples of the carbonate compound having an ethylenically unsaturated double bond include vinylene carbonate (vinylene carbonate), vinyl ethyl carbonate (vinyl ethylene carbonate), allyl ethyl carbonate (allyl ethyl carbonate), and the like. Preferably, vinylene carbonate is used from the viewpoint of obtaining the insulating resin layer 19 as a dense film.
　絶縁樹脂層１９の厚みは、例えば、１ｎｍ以上、好ましくは、３ｎｍ以上であり、また、例えば、１μｍ以下、好ましくは、８００ｎｍ以下である。絶縁樹脂層１９の厚みが、上記下限に満たないと、副反応（後述）を抑制できない。また、絶縁樹脂層１９の厚みが、上記上限を超えると、絶縁樹脂層１９と活物質（後述）との間の導電性を確保することができない。 The thickness of the insulating resin layer 19 is, for example, 1 nm or more, preferably 3 nm or more, and for example, 1 μm or less, preferably 800 nm or less. If the thickness of the insulating resin layer 19 is less than the lower limit, side reactions (described later) cannot be suppressed. Moreover, when the thickness of the insulating resin layer 19 exceeds the above upper limit, the conductivity between the insulating resin layer 19 and an active material (described later) cannot be ensured.
　集電体１を作製するには、例えば、まず、導電樹脂層６を形成する。 In order to produce the current collector 1, for example, first, the conductive resin layer 6 is formed.
　導電樹脂層６を形成するには、具体的には、まず、導電樹脂含有溶液（ワニス）を調製し、次いで、その導電樹脂含有溶液を基材の上に塗布し、塗膜を形成した後、加熱する。 In order to form the conductive resin layer 6, specifically, first, a conductive resin-containing solution (varnish) is prepared, and then the conductive resin-containing solution is applied on a substrate to form a coating film. , Heat.
　導電樹脂含有溶液は、樹脂と、導電性材料とを配合することにより、導電樹脂組成物を調製し、必要により、それに溶媒を配合することにより得られる。 The conductive resin-containing solution is obtained by blending a resin and a conductive material to prepare a conductive resin composition, and if necessary, blending a solvent.
　溶媒としては、例えば、水、有機溶媒などが挙げられ、有機溶媒としては、例えば、エタノールなどのアルコール類、例えば、酢酸エチルなどのエステル類、例えば、メチルエチルケトンなどのケトン類、例えば、Ｎ－メチルピロリドンなどの窒素含有有機溶媒などが挙げられる。これら溶媒は、単独使用または併用することができる。溶媒の配合割合は、導電樹脂組成物１００質量部に対して、例えば、３０質量部以上、好ましくは、９０質量部以上であり、また、例えば、２７００質量部以下、好ましくは、１２００質量部以下である。 Examples of the solvent include water and organic solvents. Examples of the organic solvent include alcohols such as ethanol, esters such as ethyl acetate, ketones such as methyl ethyl ketone, and N-methyl. Examples thereof include nitrogen-containing organic solvents such as pyrrolidone. These solvents can be used alone or in combination. The mixing ratio of the solvent is, for example, 30 parts by mass or more, preferably 90 parts by mass or more, and, for example, 2700 parts by mass or less, preferably 1200 parts by mass or less with respect to 100 parts by mass of the conductive resin composition. It is.
　基材は、略平板状をなし、例えば、ポリエチレン、ポリプロピレンなどのポリオレフィン、例えば、ポリエチレンテレフタレート、ポリエチレンナフタレートなどのポリエステルなどの樹脂材料、例えば、鉄、アルミニウム、ステンレスなどの金属材料、例えば、シリコン、ガラスなどのセラミックス材料などから形成される。好ましくは、ガラスから形成される。 The substrate has a substantially flat plate shape, for example, a polyolefin such as polyethylene and polypropylene, a resin material such as a polyester such as polyethylene terephthalate and polyethylene naphthalate, a metal material such as iron, aluminum, and stainless steel, such as silicon. It is formed from a ceramic material such as glass. Preferably, it is formed from glass.
　導電樹脂含有溶液の基材の上への塗布方法としては、例えば、ロールコート法、グラビアコート法、スピンコート法、バーコート法などが挙げられる。 Examples of the method for applying the conductive resin-containing solution onto the substrate include a roll coating method, a gravure coating method, a spin coating method, and a bar coating method.
　また、加熱温度は、例えば、３０℃以上、好ましくは、５０℃以上であり、また、例えば、４５０℃以下、好ましくは３５０℃以下である。また、加熱時間は、例えば、０．１分以上、好ましくは、１分以上であり、また、例えば、２００分以下、好ましくは、１００分以下である。 The heating temperature is, for example, 30 ° C. or higher, preferably 50 ° C. or higher, and for example, 450 ° C. or lower, preferably 350 ° C. or lower. The heating time is, for example, 0.1 minutes or more, preferably 1 minute or more, and for example, 200 minutes or less, preferably 100 minutes or less.
　この塗膜の加熱は、異なる温度で複数回実施することができる。例えば、第２段階目の加熱温度および時間のそれぞれが、第１段階目の加熱温度および時間のそれぞれを上回る２段階目の加熱を実施することができる。 The heating of this coating film can be carried out several times at different temperatures. For example, it is possible to perform second-stage heating in which the second-stage heating temperature and time each exceed the first-stage heating temperature and time, respectively.
　具体的には、第１段階目の加熱条件は、温度が、例えば、５０℃以上、好ましくは、７０℃以上であり、また、例えば、２００℃未満、好ましくは、１５０℃未満であり、時間が、例えば、１分以上、好ましくは、５分以上であり、また、例えば、３０分以下、好ましくは、２０分以下である。第２段階目の加熱条件は、温度が、例えば、１５０℃以上、好ましくは、２５０℃以上であり、また、例えば、４２０℃以下、好ましくは、３７０℃以下であり、時間が、例えば、１０分以上、好ましくは、２０分以上であり、また、例えば、２００分以下、好ましくは、１５０分以下である。 Specifically, the heating condition of the first stage is such that the temperature is, for example, 50 ° C. or higher, preferably 70 ° C. or higher, for example, less than 200 ° C., preferably less than 150 ° C., and time Is, for example, 1 minute or more, preferably 5 minutes or more, and for example, 30 minutes or less, preferably 20 minutes or less. As for the heating conditions of the second stage, the temperature is, for example, 150 ° C. or more, preferably 250 ° C. or more, for example, 420 ° C. or less, preferably 370 ° C. or less, and the time is, for example, 10 Minutes or more, preferably 20 minutes or more, and for example, 200 minutes or less, preferably 150 minutes or less.
　第１段階目の加熱により、塗膜を乾燥でき、乾燥させた塗膜を、第２段階目の加熱により、硬化（すなわち、キュア）することができる。 The coating film can be dried by heating in the first stage, and the dried coating film can be cured (that is, cured) by heating in the second stage.
　上記のようにして、基材の上に導電樹脂層６を形成した後、導電樹脂層６を基材から剥離する。 After forming the conductive resin layer 6 on the base material as described above, the conductive resin layer 6 is peeled off from the base material.
　その後、導電樹脂層６の上面全面に絶縁樹脂層１９を形成する。 Thereafter, an insulating resin layer 19 is formed on the entire upper surface of the conductive resin layer 6.
　絶縁樹脂層１９を形成するには、導電樹脂層６の上面全面に絶縁樹脂を塗布して形成する。また、予め、絶縁樹脂層１９を図示しない基材の上面に絶縁樹脂から形成し、次いで、絶縁樹脂層１９を導電樹脂層６の上面に転写（積層）することもできる。 In order to form the insulating resin layer 19, an insulating resin is applied to the entire upper surface of the conductive resin layer 6. Alternatively, the insulating resin layer 19 may be previously formed from an insulating resin on the upper surface of a base material (not shown), and then the insulating resin layer 19 may be transferred (laminated) to the upper surface of the conductive resin layer 6.
　好ましくは、ポリカーボネート樹脂の場合には、例えば、縮合重合可能モノマーおよび／または付加重合可能モノマーなどのモノマーを含むモノマー液を調製し、次いで、モノマー液を、導電樹脂層６の上面全面に塗布して塗膜を形成し、その後、塗膜中のモノマーを反応させる。 Preferably, in the case of a polycarbonate resin, for example, a monomer liquid containing a monomer such as a condensation polymerizable monomer and / or an addition polymerizable monomer is prepared, and then the monomer liquid is applied to the entire upper surface of the conductive resin layer 6. Then, a coating film is formed, and then the monomers in the coating film are reacted.
　モノマー液を調製するには、例えば、モノマーと、重合開始剤と、溶媒とを混合する。 To prepare the monomer solution, for example, a monomer, a polymerization initiator, and a solvent are mixed.
　重合開始剤としては、モノマーが付加重合可能モノマーである場合には、例えば、ラジカル発生剤が挙げられ、具体的には、熱により分解してラジカルを発生させる熱重合開始剤、例えば、光により分解してラジカルを発生させる光重合開始剤などが挙げられる。好ましくは、光重合開始剤が挙げられる。 As the polymerization initiator, when the monomer is an addition-polymerizable monomer, for example, a radical generator may be mentioned. Specifically, a thermal polymerization initiator that decomposes by heat to generate radicals, for example, by light Examples thereof include photopolymerization initiators that decompose to generate radicals. Preferably, a photopolymerization initiator is used.
　具体的には、重合開始剤としては、例えば、過酸化物、アゾ化合物、ジハロゲン化合物、アルキルフェノン化合物、アシルフォスフィンオキサイド化合物などが挙げられる。好ましくは、アルキルフェノン化合物が挙げられる。これら重合開始剤は、単独使用または併用することができる。 Specifically, examples of the polymerization initiator include peroxides, azo compounds, dihalogen compounds, alkylphenone compounds, acylphosphine oxide compounds, and the like. Preferably, an alkylphenone compound is used. These polymerization initiators can be used alone or in combination.
　重合開始剤の配合割合は、モノマー１００質量部に対して、例えば、０．０１質量部以上、好ましくは、０．１質量部以上であり、また、例えば、１０質量部以下、好ましくは、５質量部以下である。 The blending ratio of the polymerization initiator is, for example, 0.01 parts by mass or more, preferably 0.1 parts by mass or more, for example, 10 parts by mass or less, preferably 5 parts by mass with respect to 100 parts by mass of the monomer. It is below mass parts.
　溶媒としては、例えば、上記した有機溶媒などが挙げられ、好ましくは、アルコール類が挙げられる。これら溶媒は、単独使用または併用することができる。 Examples of the solvent include the organic solvents described above, and preferably alcohols. These solvents can be used alone or in combination.
　溶媒の配合割合を、モノマー液に対するモノマーの質量割合が、例えば、０．０１質量％以上、好ましくは、０．１質量％以上となり、また、例えば、５０質量％以下、好ましくは、２０質量％以下となるように、調整する。 The mixing ratio of the solvent is such that the mass ratio of the monomer to the monomer liquid is, for example, 0.01% by mass or more, preferably 0.1% by mass or more, and for example, 50% by mass or less, preferably 20% by mass. Adjust so that:
　次いで、モノマー液を、上記した塗布方法によって、導電樹脂層６の上面全面に塗布する。これによって、モノマー液の塗膜を形成する。 Next, the monomer liquid is applied to the entire upper surface of the conductive resin layer 6 by the above-described application method. Thereby, a coating film of the monomer liquid is formed.
　その後、塗膜中のモノマーを反応させる。 Then, the monomer in the coating film is reacted.
　モノマーを反応させるには、重合開始剤が光重合開始剤を含有する場合には、例えば、紫外線などの光を塗膜に照射する。光の照射量は、例えば、１０ｍＪ／ｃｍ２以上、好ましくは、１００ｍＪ／ｃｍ２以上であり、また、例えば、１００００ｍＪ／ｃｍ２以下、好ましくは、１０００ｍＪ／ｃｍ２以下である。 In order to react the monomer, when the polymerization initiator contains a photopolymerization initiator, for example, the coating film is irradiated with light such as ultraviolet rays. The dose of light, for example, 10 mJ / cm 2 or more, preferably at most 100 mJ / cm 2 or more, and is, for example, 10000 mJ / cm 2 or less, preferably 1000 mJ / cm 2 or less.
　あるいは、重合開始剤が熱重合開始剤を含有する場合には、塗膜を加熱する。加熱条件は、加熱温度が、例えば、５０℃以上、好ましくは、１００℃以上であり、また、例えば、２００℃以下、好ましくは、１４０℃以下であり、加熱時間が、例えば、１０秒以上、好ましくは、１分以上であり、また、例えば、６０分以下、好ましくは、３０分以下である。 Alternatively, when the polymerization initiator contains a thermal polymerization initiator, the coating film is heated. As for the heating conditions, the heating temperature is, for example, 50 ° C. or more, preferably 100 ° C. or more, for example, 200 ° C. or less, preferably 140 ° C. or less, and the heating time is, for example, 10 seconds or more. It is preferably 1 minute or longer, and for example, 60 minutes or shorter, preferably 30 minutes or shorter.
　重合開始剤が、光重合開始剤および熱重合開始剤を含有する場合には、塗膜に対して、光の照射と、加熱とを併用する。 When the polymerization initiator contains a photopolymerization initiator and a thermal polymerization initiator, light irradiation and heating are used in combination with the coating film.
　これによって、導電樹脂層６の上面全面に絶縁樹脂層１９を形成する。 Thereby, the insulating resin layer 19 is formed on the entire upper surface of the conductive resin layer 6.
　あるいは、モノマー液に導電樹脂層６を浸漬して、電位を導電樹脂層６にかける、すなわち、導電樹脂層６に電流を流すことにより、絶縁樹脂層１９を形成することもできる。 Alternatively, the insulating resin layer 19 can also be formed by immersing the conductive resin layer 6 in the monomer solution and applying a potential to the conductive resin layer 6, that is, passing a current through the conductive resin layer 6.
　このようにして作製された集電体１は、各種装置の集電体１として、用いることができる。具体的には、集電体１を、例えば、バイポーラ電池７の集電体１として用いることができる。このバイポーラ電池７は、リチウムイオン二次電池として用いることができる。 The current collector 1 produced in this way can be used as the current collector 1 of various devices. Specifically, the current collector 1 can be used as the current collector 1 of the bipolar battery 7, for example. This bipolar battery 7 can be used as a lithium ion secondary battery.
　次に、図２および図３を参照して、図１に示す集電体１を備えるバイポーラ電池７について、説明する。 Next, the bipolar battery 7 including the current collector 1 shown in FIG. 1 will be described with reference to FIGS.
　図２において、バイポーラ電池７は、双極型リチウムイオン二次電池であって、充放電反応が進行する充放電部８と、充放電部８を収容する外装材９とを備える。 In FIG. 2, the bipolar battery 7 is a bipolar lithium ion secondary battery, and includes a charging / discharging unit 8 in which a charging / discharging reaction proceeds, and an exterior material 9 that houses the charging / discharging unit 8.
　充放電部８は、略平板状に形成されており、互いに間隔を隔てて複数設けられる電極１０と、各電極１０間に配置される電解質層１１とを備える。 The charging / discharging unit 8 is formed in a substantially flat plate shape, and includes a plurality of electrodes 10 provided at intervals from each other, and an electrolyte layer 11 disposed between the electrodes 10.
　電極１０は、厚み方向に複数積層されており、厚み方向一端（最上側）および厚み方向いる他端（最下側）に形成される２つの末端電極１３と、２つの末端電極１３の間に配置される複数の主電極１２とを備える。 A plurality of electrodes 10 are stacked in the thickness direction, and are formed between two end electrodes 13 formed at one end in the thickness direction (uppermost side) and the other end in the thickness direction (lowermost side). And a plurality of main electrodes 12 arranged.
　主電極１２のそれぞれは、双極型電極であり、具体的には、図３に示すように、集電体１と、集電体１の上面（厚み方向一方面）に積層される正極１４と、集電体１の下面（厚み方向他方面）に積層される負極１５とを備える。 Each of the main electrodes 12 is a bipolar electrode. Specifically, as shown in FIG. 3, a current collector 1 and a positive electrode 14 laminated on the upper surface (one surface in the thickness direction) of the current collector 1 And the negative electrode 15 laminated on the lower surface (the other surface in the thickness direction) of the current collector 1.
　集電体１は、導電樹脂層６と、導電樹脂層６の下面全面に形成される絶縁樹脂層１９とを備える。 The current collector 1 includes a conductive resin layer 6 and an insulating resin layer 19 formed on the entire lower surface of the conductive resin layer 6.
　正極１４は、導電樹脂層６の端部（厚み方向に直交する面方向周端部）を露出するパターンで、導電樹脂層６の上面に、正極１４の下面全面で接触するように形成されている。 The positive electrode 14 is a pattern that exposes an end of the conductive resin layer 6 (a peripheral edge in the plane direction perpendicular to the thickness direction), and is formed so as to be in contact with the upper surface of the conductive resin layer 6 over the entire lower surface of the positive electrode 14. Yes.
　正極１４は、正極活物質を必須成分として含有し、バインダを任意成分として含有する正極材料から形成されている。 The positive electrode 14 is made of a positive electrode material containing a positive electrode active material as an essential component and a binder as an optional component.
　正極活物質としては、双極型リチウムイオン二次電池で用いられる正極活物質であれば特に限定されず、例えば、リチウム化合物が挙げられる。リチウム化合物としては、例えば、ＬｉＣｏＯ２、ＬｉＮｉＯ２、Ｌｉ（Ｎｉ－Ｃｏ－Ｍｎ）Ｏ２などのリチウム－遷移金属複合酸化物（リチウム系複合酸化物）、例えば、リチウム－遷移金属リン酸化合物、例えば、リチウム－遷移金属硫酸化合物などが挙げられる。 The positive electrode active material is not particularly limited as long as it is a positive electrode active material used in a bipolar lithium ion secondary battery, and examples thereof include a lithium compound. Examples of the lithium compound include lithium-transition metal composite oxides (lithium-based composite oxides) such as LiCoO 2 , LiNiO 2 , and Li (Ni—Co—Mn) O 2, such as lithium-transition metal phosphate compounds For example, a lithium-transition metal sulfate compound can be used.
　正極活物質は、単独使用または併用することができる。 The positive electrode active material can be used alone or in combination.
　正極活物質としては、好ましくは、容量、出力特性の観点から、リチウム－遷移金属複合酸化物が挙げられる。 The positive electrode active material is preferably a lithium-transition metal composite oxide from the viewpoint of capacity and output characteristics.
　バインダとしては、特に限定されず、例えば、ポリエチレン、ポリプロピレン、ポリエチレンテレフタレート（ＰＥＴ）、ポリエーテルニトリル（ＰＥＮ）、ポリアクリロニトリル、ポリイミド、ポリアミド、セルロース、カルボキシメチルセルロース（ＣＭＣ）、エチレン－酢酸ビニル共重合体、ポリ塩化ビニル、スチレン・ブタジエンゴム（ＳＢＲ）、イソプレンゴム、ブタジエンゴム、エチレン・プロピレンゴム、エチレン・プロピレン・ジエン共重合体、スチレン・ブタジエン・スチレンブロック共重合体およびその水素添加物、スチレン・イソプレン・スチレンブロック共重合体およびその水素添加物、ポリフッ化ビニリデン（ＰＶｄＦ）、ポリテトラフルオロエチレン（ＰＴＦＥ）、テトラフルオロエチレン・ヘキサフルオロプロピレン共重合体（ＦＥＰ）、テトラフルオロエチレン・パーフルオロアルキルビニルエーテル共重合体（ＰＦＡ）、エチレン・テトラフルオロエチレン共重合体（ＥＴＦＥ）、ポリクロロトリフルオロエチレン（ＰＣＴＦＥ）、エチレン・クロロトリフルオロエチレン共重合体（ＥＣＴＦＥ）、ポリフッ化ビニル（ＰＶＦ）、ビニリデンフルオライド－ヘキサフルオロプロピレン系フッ素ゴム（ＶＤＦ－ＨＦＰ系フッ素ゴム）、ビニリデンフルオライド－ヘキサフルオロプロピレン－テトラフルオロエチレン系フッ素ゴム（ＶＤＦ－ＨＦＰ－ＴＦＥ系フッ素ゴム）、ビニリデンフルオライド－ペンタフルオロプロピレン系フッ素ゴム（ＶＤＦ－ＰＦＰ系フッ素ゴム）、ビニリデンフルオライド－ペンタフルオロプロピレン－テトラフルオロエチレン系フッ素ゴム（ＶＤＦ－ＰＦＰ－ＴＦＥ系フッ素ゴム）、ビニリデンフルオライド－パーフルオロメチルビニルエーテル－テトラフルオロエチレン系フッ素ゴム（ＶＤＦ－ＰＦＭＶＥ－ＴＦＥ系フッ素ゴム）、ビニリデンフルオライド－クロロトリフルオロエチレン系フッ素ゴム（ＶＤＦ－ＣＴＦＥ系フッ素ゴム）などのビニリデンフルオライド系フッ素ゴム、エポキシ樹脂などが挙げられる。 The binder is not particularly limited. For example, polyethylene, polypropylene, polyethylene terephthalate (PET), polyether nitrile (PEN), polyacrylonitrile, polyimide, polyamide, cellulose, carboxymethyl cellulose (CMC), ethylene-vinyl acetate copolymer , Polyvinyl chloride, styrene / butadiene rubber (SBR), isoprene rubber, butadiene rubber, ethylene / propylene rubber, ethylene / propylene / diene copolymer, styrene / butadiene / styrene block copolymer and its hydrogenated product, styrene / Isoprene / styrene block copolymer and hydrogenated product thereof, polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), tetrafluoroethylene / hexafluoro Lopylene copolymer (FEP), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), ethylene / tetrafluoroethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene / chlorotrifluoroethylene Copolymer (ECTFE), polyvinyl fluoride (PVF), vinylidene fluoride-hexafluoropropylene fluoro rubber (VDF-HFP fluoro rubber), vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene fluoro rubber (VDF- HFP-TFE fluorine rubber), vinylidene fluoride-pentafluoropropylene fluorine rubber (VDF-PFP fluorine rubber), vinylidene fluoride-pentafluoropropylene-tetrafluor Ethylene fluoro rubber (VDF-PFP-TFE fluoro rubber), vinylidene fluoride-perfluoromethyl vinyl ether-tetrafluoro ethylene fluoro rubber (VDF-PFMVE-TFE fluoro rubber), vinylidene fluoride-chlorotrifluoroethylene Examples thereof include vinylidene fluoride fluorine rubber such as fluorine rubber (VDF-CTFE fluorine rubber), epoxy resin, and the like.
　バインダは、単独使用または併用することができる。 The binder can be used alone or in combination.
　好ましくは、ＰＶｄＦ、ポリイミド、スチレン・ブタジエンゴム、ＣＭＣ、ポリプロピレン、ＰＴＦＥ、ポリアクリロニトリル、ポリアミドが挙げられる。 Preferably, PVdF, polyimide, styrene / butadiene rubber, CMC, polypropylene, PTFE, polyacrylonitrile, and polyamide are used.
　バインダの配合割合は、正極材料１００質量部に対して、例えば、０．５質量部以上、好ましくは、１質量部以上であり、また、例えば、１５質量部以下であり、好ましくは、１０質量部以下である。 The blending ratio of the binder is, for example, 0.5 parts by mass or more, preferably 1 part by mass or more, for example, 15 parts by mass or less, preferably 10 parts by mass with respect to 100 parts by mass of the positive electrode material. Or less.
　また、正極材料には、例えば、導電助剤、電解質塩、イオン伝導性ポリマーなどの添加剤を適宜の割合で添加することができる。 Further, for example, additives such as a conductive additive, an electrolyte salt, and an ion conductive polymer can be added to the positive electrode material at an appropriate ratio.
　導電助剤としては、例えば、上記した炭素系フィラーなどが挙げられる。 Examples of the conductive aid include the carbon-based filler described above.
　電解質塩としては、例えば、Ｌｉ（Ｃ２Ｆ５ＳＯ２）２Ｎ、ＬｉＰＦ６、ＬｉＢＦ４、ＬｉＣｌＯ４、ＬｉＡｓＦ６、ＬｉＣＦ３ＳＯ３などのリチウム塩が挙げられる。 Examples of the electrolyte salt include lithium salts such as Li (C 2 F 5 SO 2 ) 2 N, LiPF 6 , LiBF 4 , LiClO 4 , LiAsF 6 , and LiCF 3 SO 3 .
　イオン伝導性ポリマーとしては、例えば、ポリエチレンオキシド（ＰＥＯ）系、ポリプロピレンオキシド（ＰＰＯ）系などのポリアルキレンオキシドが挙げられる。 Examples of the ion conductive polymer include polyalkylene oxides such as polyethylene oxide (PEO) and polypropylene oxide (PPO).
　正極１４を導電樹脂層６の上面に積層するには、例えば、上記した正極材料を、例えば、Ｎ－メチルピロリドン（ＮＭＰ）、ジメチルカーボネート（ＤＭＣ）、アセトニトリルなどの溶媒に適宜の割合で配合して、スラリーを調製する。次いで、スラリーを導電樹脂層６の上面に塗布し、その後、塗膜を加熱により乾燥させる。 In order to laminate the positive electrode 14 on the upper surface of the conductive resin layer 6, for example, the above-described positive electrode material is blended in a solvent such as N-methylpyrrolidone (NMP), dimethyl carbonate (DMC), or acetonitrile at an appropriate ratio. To prepare a slurry. Next, the slurry is applied to the upper surface of the conductive resin layer 6, and then the coating film is dried by heating.
　これにより、正極１４を導電樹脂層６の上面に上記したパターンで形成する。 Thereby, the positive electrode 14 is formed on the upper surface of the conductive resin layer 6 in the pattern described above.
　負極１５は、絶縁樹脂層１９の端部（面方向周端部）を露出するように、絶縁樹脂層１９の下面に、負極１５の上面全面で接触するように形成されており、具体的には、厚み方向に投影したときに、正極１４のパターンと同一パターンとなるように、形成されている。これにより、絶縁樹脂層１９は、負極１５と導電樹脂層６との間に介在されている。 The negative electrode 15 is formed so as to be in contact with the lower surface of the insulating resin layer 19 over the entire upper surface of the negative electrode 15 so as to expose the end portion (peripheral end portion in the plane direction) of the insulating resin layer 19. Is formed so as to be the same pattern as the pattern of the positive electrode 14 when projected in the thickness direction. Thereby, the insulating resin layer 19 is interposed between the negative electrode 15 and the conductive resin layer 6.
　また、負極１５は、負極活物質を必須成分として含有し、バインダを任意成分として含有する負極材料から形成されている。 The negative electrode 15 is formed of a negative electrode material containing a negative electrode active material as an essential component and a binder as an optional component.
　負極活物質としては、双極型リチウムイオン二次電池で用いられる負極活物質であれば特に限定されず、例えば、グラファイト、ソフトカーボン、ハードカーボンなどの炭素活物質、リチウム－遷移金属複合酸化物（例えば、Ｌｉ４Ｔｉ５Ｏ１２）、金属活物質、リチウム合金系負極活物質などが挙げられる。 The negative electrode active material is not particularly limited as long as it is a negative electrode active material used in a bipolar lithium ion secondary battery. For example, carbon active materials such as graphite, soft carbon, and hard carbon, lithium-transition metal composite oxides ( For example, Li 4 Ti 5 O 12) , metal active material, and lithium alloy-based negative electrode active material.
　負極活物質は、単独使用または併用することができる。 The negative electrode active material can be used alone or in combination.
　負極活物質としては、好ましくは、容量、出力特性の観点から、炭素活物質、リチウム－遷移金属複合酸化物が挙げられる。 The negative electrode active material is preferably a carbon active material or a lithium-transition metal composite oxide from the viewpoint of capacity and output characteristics.
　バインダは、正極材料で例示したバインダが挙げられる。バインダの配合割合は、上記と同様である。 Examples of the binder include the binder exemplified in the positive electrode material. The blending ratio of the binder is the same as above.
　また、負極材料には、例えば、正極材料で例示した添加剤を適宜の割合で添加することができる。 Further, for example, the additive exemplified in the positive electrode material can be added to the negative electrode material at an appropriate ratio.
　負極１５を絶縁樹脂層１９の下面に積層するには、例えば、上記した負極材料を上記した溶媒に適宜の割合で配合して、スラリーを調製する。次いで、スラリーを絶縁樹脂層１９の下面に塗布し、その後、塗膜を加熱により乾燥させる。 In order to laminate the negative electrode 15 on the lower surface of the insulating resin layer 19, for example, the above-described negative electrode material is blended with the above-described solvent in an appropriate ratio to prepare a slurry. Next, the slurry is applied to the lower surface of the insulating resin layer 19, and then the coating film is dried by heating.
　これにより、負極１５を絶縁樹脂層１９の下面に上記したパターンで形成する。 Thereby, the negative electrode 15 is formed on the lower surface of the insulating resin layer 19 with the above-described pattern.
　そして、複数の主電極１２は、厚み方向において、複数の電解質層１１を介して積層されている。つまり、厚み方向に隣接する複数の主電極１２の間に、電解質層１１が介在しており、より具体的には、主電極１２と電解質層１１とが厚み方向に順次交互に積層されている。 The plurality of main electrodes 12 are stacked via the plurality of electrolyte layers 11 in the thickness direction. That is, the electrolyte layer 11 is interposed between the plurality of main electrodes 12 adjacent to each other in the thickness direction, and more specifically, the main electrodes 12 and the electrolyte layers 11 are sequentially stacked alternately in the thickness direction. .
　また、一の主電極１２Ａの正極１４と、一の主電極１２Ａに隣接する他の主電極１２Ｂの負極１５とが、厚み方向に対向配置され、かつ、電解質層１１がそれらの間に介在し、それらに挟まれるように、各主電極１２および各電解質層１１が交互に積層されている。 Further, the positive electrode 14 of one main electrode 12A and the negative electrode 15 of another main electrode 12B adjacent to the one main electrode 12A are disposed to face each other in the thickness direction, and the electrolyte layer 11 is interposed between them. The main electrodes 12 and the electrolyte layers 11 are alternately stacked so as to be sandwiched between them.
　電解質層１１は、略平板状をなし、隣接する主電極１２の間において、電解質を保持できるように構成されている。 The electrolyte layer 11 has a substantially flat plate shape and is configured to hold the electrolyte between adjacent main electrodes 12.
　電解質としては、例えば、液体電解質、固体電解質が挙げられる。 Examples of the electrolyte include a liquid electrolyte and a solid electrolyte.
　液体電解質は、支持塩が有機溶媒に溶解した形態を有する。有機溶媒としては、例えば、エチレンカーボネート（ＥＣ）やプロピレンカーボネート（ＰＣ）などのカーボネート化合物が挙げられる。また、支持塩としては、例えば、リチウム塩が挙げられる。 The liquid electrolyte has a form in which the supporting salt is dissolved in an organic solvent. Examples of the organic solvent include carbonate compounds such as ethylene carbonate (EC) and propylene carbonate (PC). Examples of the supporting salt include a lithium salt.
　一方、固体電解質としては、例えば、電解液を含むゲル電解質、電解液を含まない真性固体電解質が挙げられる。 On the other hand, examples of the solid electrolyte include a gel electrolyte containing an electrolytic solution and an intrinsic solid electrolyte not containing an electrolytic solution.
　ゲル電解質は、上記したイオン伝導性ポリマーからなるマトリックスポリマーに、上記した液体電解質が分散されることにより形成される。 The gel electrolyte is formed by dispersing the above liquid electrolyte in a matrix polymer made of the above ion conductive polymer.
　なお、電解質層１１が液体電解質やゲル電解質から形成される場合には、電解質層１１には、セパレータを設けることもできる。セパレータとしては、例えば、ポリエチレンやポリプロピレンなどのポリオレフィンからなる微多孔膜などが挙げられる。 In addition, when the electrolyte layer 11 is formed from a liquid electrolyte or a gel electrolyte, the electrolyte layer 11 can be provided with a separator. Examples of the separator include a microporous film made of polyolefin such as polyethylene and polypropylene.
　真性固体電解質は、上記のマトリックスポリマーに支持塩が溶解することにより調製されており、有機溶媒（可塑剤など）を含まない。 The intrinsic solid electrolyte is prepared by dissolving a supporting salt in the above matrix polymer, and does not contain an organic solvent (such as a plasticizer).
　そして、正極１４（具体的には、一の主電極１２Ａの正極１４）と、電解質層１１と、負極１５（正極１４と電解質層１１を挟む負極１５、具体的には、他の主電極１２Ｂの負極１５）とは、１つの単電池層２３を構成する。 Then, the positive electrode 14 (specifically, the positive electrode 14 of one main electrode 12A), the electrolyte layer 11, and the negative electrode 15 (the negative electrode 15 sandwiching the positive electrode 14 and the electrolyte layer 11, specifically, the other main electrode 12B). The negative electrode 15) constitutes a single cell layer 23.
　これによって、バイポーラ電池７は、単電池層２３が複数積層されることにより、形成されている。互いに隣接する単電池層２３の間には、集電体１が介在している。 Thus, the bipolar battery 7 is formed by laminating a plurality of single battery layers 23. The current collector 1 is interposed between the unit cell layers 23 adjacent to each other.
　図２に示すように、２つの末端電極１３のそれぞれは、集電体１と、集電体１の上面または下面に形成される、正極１４および負極１５のいずれか一方とを備えている。 2, each of the two terminal electrodes 13 includes a current collector 1 and either a positive electrode 14 or a negative electrode 15 formed on the upper surface or the lower surface of the current collector 1.
　具体的には、正極側（最下側）の末端電極１３ａは、集電体１と、その上面に積層される正極１４とを備える一方、負極１５を備えていない。 Specifically, the terminal electrode 13a on the positive electrode side (lowermost side) includes the current collector 1 and the positive electrode 14 laminated on the upper surface thereof, but does not include the negative electrode 15.
　正極側の末端電極１３ａの下面には、正極集電板１６が設けられている。 A positive electrode current collector plate 16 is provided on the lower surface of the terminal electrode 13a on the positive electrode side.
　正極集電板１６は、正極側の末端電極１３ａの下面を被覆する被覆部と、被覆部から面方向一方向（図２における右方向）に延出する延出部とを一体的に備えている。 The positive electrode current collector plate 16 is integrally provided with a covering portion that covers the lower surface of the terminal electrode 13a on the positive electrode side, and an extending portion that extends from the covering portion in one plane direction (right direction in FIG. 2). Yes.
　負極側（最上側）の末端電極１３ｂは、集電体１と、その下面に積層される負極１５とを備える一方、正極１４を備えていない。 The terminal electrode 13b on the negative electrode side (uppermost side) includes the current collector 1 and the negative electrode 15 stacked on the lower surface thereof, but does not include the positive electrode 14.
　負極側の末端電極１３ｂの上面には、負極集電板１７が設けられている。 A negative electrode current collector plate 17 is provided on the upper surface of the terminal electrode 13b on the negative electrode side.
　負極集電板１７は、負極側の末端電極１３ｂの上面を被覆する被覆部と、被覆部から面方向他方向（図２における左方向）に延出する延出部とを一体的に備えている。 The negative electrode current collector plate 17 is integrally provided with a covering portion that covers the upper surface of the terminal electrode 13b on the negative electrode side and an extending portion that extends from the covering portion in the other direction of the surface (left direction in FIG. 2). Yes.
　外装材９としては、例えば、金属ケース、あるいは、袋状のラミネートフィルムが挙げられる。好ましくは、高出力化や冷却性能に優れ、バイポーラ電池７をＥＶおよび／またはＨＥＶに搭載する観点から、ラミネートフィルムが挙げられる。ラミネートフィルムとしては、例えば、ＰＰと、アルミニウムと、ナイロン（ポリアミド）とをこの順に積層して形成される３層構造のラミネートフィルムなどが挙げられる。 Examples of the exterior material 9 include a metal case or a bag-like laminate film. Preferably, a laminate film is used from the viewpoint of achieving high output and excellent cooling performance and mounting the bipolar battery 7 on the EV and / or HEV. Examples of the laminate film include a laminate film having a three-layer structure formed by laminating PP, aluminum, and nylon (polyamide) in this order.
　外装材９は、充放電部８を封止する。一方、外装材９は、正極集電板１６および負極集電板１７の延出部の遊端部をそれぞれ露出する。 The exterior material 9 seals the charge / discharge part 8. On the other hand, the exterior material 9 exposes the free end portions of the extending portions of the positive electrode current collector plate 16 and the negative electrode current collector plate 17, respectively.
　そして、バイポーラ電池７の放電（発電）時には、正極集電板１６および負極集電板１７において外装材９から露出する遊端部を介して、充放電部８における放電反応に基づく電気を取り出す一方、バイポーラ電池７の充電（蓄電）時には、かかる遊端部から充放電部８に電気を供給する。 At the time of discharging (power generation) of the bipolar battery 7, while taking out the electricity based on the discharge reaction in the charging / discharging unit 8 through the free end portions exposed from the exterior material 9 in the positive electrode current collecting plate 16 and the negative electrode current collecting plate 17. When charging (charging) the bipolar battery 7, electricity is supplied from the free end portion to the charge / discharge portion 8.
　このようなバイポーラ電池７は、ＥＶ、ＨＥＶなどの車両に搭載されて、駆動用電源として利用される。あるいは、バイポーラ電池７を、例えば、無停電電源装置などの載置用電源として利用することもできる。 Such a bipolar battery 7 is mounted on a vehicle such as EV or HEV and used as a driving power source. Alternatively, the bipolar battery 7 can be used as a mounting power source such as an uninterruptible power supply.
　そして、この集電体１は、樹脂および導電性材料を含む導電樹脂層６を備えるので、集電体１の軽量化を図り、単位質量当たりの出力密度を向上することができる。 And since this electrical power collector 1 is provided with the conductive resin layer 6 containing resin and an electroconductive material, the weight reduction of the electrical power collector 1 can be achieved and the output density per unit mass can be improved.
　また、集電体１は、導電樹脂層６の厚み方向一方面に形成される絶縁樹脂層１９を備えるので、導電樹脂層６の厚み方向一方面での副反応を抑制することができる。 Further, since the current collector 1 includes the insulating resin layer 19 formed on one surface in the thickness direction of the conductive resin layer 6, side reactions on one surface in the thickness direction of the conductive resin layer 6 can be suppressed.
　すなわち、バイポーラ電池７の充電時には、負極１５近傍は、還元環境下にさらされる。とりわけ、負極活物質に炭素活物質を用いた場合には、特に強い還元環境下にさらされる。そのため、電解質層１１が液体電解質である場合に、液体電解質が負極１５を透過して集電体１と接触してしまうと、副反応が生じる懸念がある。副反応は、充電作用をもたらす負極活物質と電解質層１１の電解質との主反応以外の反応であり、例えば、バイポーラ電池７が双極型リチウムイオン二次電池の場合では、例えば、集電体１の還元分解、電解質層１１の電解質の分解などが挙げられる。この副反応は、集電体１や電解質層１１が劣化するため、できる限り抑制する必要がある。 That is, when the bipolar battery 7 is charged, the vicinity of the negative electrode 15 is exposed to a reducing environment. In particular, when a carbon active material is used as the negative electrode active material, it is exposed to a particularly strong reducing environment. Therefore, when the electrolyte layer 11 is a liquid electrolyte, if the liquid electrolyte passes through the negative electrode 15 and comes into contact with the current collector 1, a side reaction may occur. The side reaction is a reaction other than the main reaction between the negative electrode active material that brings about the charging action and the electrolyte of the electrolyte layer 11. For example, when the bipolar battery 7 is a bipolar lithium ion secondary battery, the current collector 1 And decomposition of the electrolyte of the electrolyte layer 11. This side reaction needs to be suppressed as much as possible because the current collector 1 and the electrolyte layer 11 deteriorate.
　そこで、図３のように、集電体１の導電樹脂層６の下面全面に絶縁樹脂層１９を設けることにより、導電樹脂層６と電解質層１１の電解質（とりわけ、液体電解質）との接触を抑制できるので、導電樹脂層６の表面および内部での副反応の発生を抑制することができる。そのため、集電体１は、耐久性に優れる。 Therefore, as shown in FIG. 3, by providing an insulating resin layer 19 over the entire lower surface of the conductive resin layer 6 of the current collector 1, contact between the conductive resin layer 6 and the electrolyte of the electrolyte layer 11 (particularly, a liquid electrolyte) is achieved. Since it can suppress, generation | occurrence | production of the side reaction in the surface of the conductive resin layer 6 and an inside can be suppressed. Therefore, the current collector 1 is excellent in durability.
　また、絶縁樹脂層１９は、上記した副反応を抑制するため、集電体１と電解質層１１の電解質との間に流れる電流の電流密度を低減することができる。したがって、絶縁樹脂層１９により、集電体１は、耐久性が向上する。 Further, since the insulating resin layer 19 suppresses the side reaction described above, the current density of the current flowing between the current collector 1 and the electrolyte of the electrolyte layer 11 can be reduced. Therefore, the durability of the current collector 1 is improved by the insulating resin layer 19.
　また、集電体１では、絶縁樹脂層１９が、ポリカーボネート樹脂を含む場合には、絶縁樹脂層１９は、緻密な皮膜として得られ、絶縁樹脂層１９を電解質層１１の電解質が透過することを抑制することができる。そのため、電解質層１１の電解質が導電樹脂層６に接触する量を減らすことができ、集電体１の導電樹脂層６の表面および内部での副反応を抑制できる。その結果、集電体１および電解質層１１の劣化を抑制でき、集電体１の耐久性が向上する。 Further, in the current collector 1, when the insulating resin layer 19 includes a polycarbonate resin, the insulating resin layer 19 is obtained as a dense film, and the electrolyte of the electrolyte layer 11 is transmitted through the insulating resin layer 19. Can be suppressed. Therefore, the amount of the electrolyte of the electrolyte layer 11 that contacts the conductive resin layer 6 can be reduced, and side reactions on the surface and inside of the conductive resin layer 6 of the current collector 1 can be suppressed. As a result, the deterioration of the current collector 1 and the electrolyte layer 11 can be suppressed, and the durability of the current collector 1 is improved.
　また、集電体１では、樹脂が、ポリイミドおよび／またはポリアミドイミドを含む場合には、導電樹脂層６は良好なイオン遮断性を示す。そのため、導電樹脂層６への電解質層１１の電解質のイオンの透過を遮断することができる。 Further, in the current collector 1, when the resin contains polyimide and / or polyamideimide, the conductive resin layer 6 exhibits good ion blocking properties. Therefore, permeation of electrolyte ions of the electrolyte layer 11 to the conductive resin layer 6 can be blocked.
　また、集電体１では、導電性材料が、ニッケルおよび／またはステンレスを含む場合には、集電体１の耐腐食性が向上するため、集電体１の耐久性の向上を図ることができる。 Further, in the current collector 1, when the conductive material includes nickel and / or stainless steel, the corrosion resistance of the current collector 1 is improved, so that the durability of the current collector 1 can be improved. it can.
　また、バイポーラ電池７は、耐久性に優れる集電体１を備えるので、耐久性に優れる。また、バイポーラ電池７は、リチウムイオン二次電池として好適に用いることができる。 Moreover, since the bipolar battery 7 includes the current collector 1 having excellent durability, the bipolar battery 7 has excellent durability. The bipolar battery 7 can be suitably used as a lithium ion secondary battery.
　なお、図１に示すように、絶縁樹脂層１９は、導電樹脂層６の上面全面に形成されているが、例えば、図示しないが、導電樹脂層６の上面に加えて、導電樹脂層６の下面にも設けることができる。 As shown in FIG. 1, the insulating resin layer 19 is formed on the entire upper surface of the conductive resin layer 6. For example, although not shown, in addition to the upper surface of the conductive resin layer 6, the insulating resin layer 19 It can also be provided on the lower surface.
　以下に、作製例、実施例および比較例を示し、本発明をさらに具体的に説明するが、本発明は、何らそれらに限定されない。以下に示す実施例の数値は、上記の実施形態において記載される数値（すなわち、上限値または下限値）に代替することができる。
（作製例１）
（導電樹脂層の作製）
　ポリアミドイミド（商品名「ＶＹＬＯＭＡＸ（登録商標）　ＨＲ－１６ＮＮ」、数平均分子量３０×１０３、Ｔｇ３２０℃、東洋紡社製）１００質量部と、ニッケルフィラー（商品名「ＨＣＡ－１」、球状、平均粒子径３７μｍ、日興リカ社製）２５質量部とを混合し、導電樹脂含有溶液（ワニス）を調製した。このワニスを、ガラス基材の上に塗布して塗膜を形成し、その後、１００℃で１０分間加熱して塗膜を乾燥させ、続いて２５０℃で３０分間加熱して塗膜を硬化させた。これによって、厚み１８μｍの導電樹脂層を得た。 Hereinafter, the present invention will be described more specifically with reference to production examples, examples, and comparative examples, but the present invention is not limited thereto. The numerical values in the following examples can be substituted for the numerical values (that is, the upper limit value or the lower limit value) described in the above embodiment.
(Production Example 1)
(Preparation of conductive resin layer)
Polyamideimide (trade name “VYLOMAX (registered trademark) HR-16NN”, number average molecular weight 30 × 10 3 , Tg 320 ° C., manufactured by Toyobo Co., Ltd.) 100 parts by mass, nickel filler (trade name “HCA-1”, spherical, average A conductive resin-containing solution (varnish) was prepared by mixing 25 parts by mass with a particle size of 37 μm (manufactured by Nikko Rica). This varnish is applied onto a glass substrate to form a coating film, then heated at 100 ° C. for 10 minutes to dry the coating film, and then heated at 250 ° C. for 30 minutes to cure the coating film. It was. Thus, a conductive resin layer having a thickness of 18 μm was obtained.
　次いで、ガラスから、導電樹脂層を剥離した。
（実施例１）
（絶縁樹脂層の形成）
　ビニレンカーボネート０．４質量％のエタノール溶液（モノマー液）を準備し、次いで、エタノール溶液を作製例１に記載の方法で作製した導電樹脂層の上面全面に塗布して塗膜を形成し、次いで、６００ｍＪ／ｃｍ２で紫外線を塗膜に照射することにより、導電樹脂層の上面全面に厚み１５ｎｍの絶縁樹脂層を形成した。これにより、導電樹脂層と絶縁樹脂層とを備える集電体を得た（図１参照。）。
（実施例２）
　ビニレンカーボネート０．４質量％のエタノール溶液に代えて、ビニレンカーボネート１０質量％のエタノール溶液を用いた以外は、実施例１と同様の手順で、導電樹脂層の上面全面に厚み１８ｎｍの絶縁樹脂層を形成し、導電樹脂層と絶縁樹脂層とを備える集電体を得た（図１参照。）。
（比較例１）
　絶縁樹脂層を形成せず、作製例１に記載の方法で作製した導電樹脂層を、集電体として使用した。
（評価）
（導電性）
　実施例１、２および比較例１で作製した集電体について、導電樹脂層の体積抵抗率を、ＪＩＳ　Ｋ　７１９４に準拠して、抵抗率計（ロレスタＭＣＰ－Ｔ３６０、三菱化学社製）を用いて測定し、下記のように導電樹脂層の導電性を評価した。
○：体積抵抗率が１００Ωｃｍ以下である
×：体積抵抗率が１００Ωｃｍを超過する
（負極における集電体の電流密度の測定）
　実施例１、２および比較例１で作製した集電体について、三極セル（宝泉社製）を用いて、負極において、流れる電流の電流密度の測定を行った。具体的には、５ｍＶの一定電圧において、電圧印加開始から５分後における電流密度を測定した。 Next, the conductive resin layer was peeled from the glass.
(Example 1)
(Formation of insulating resin layer)
A vinylene carbonate 0.4 mass% ethanol solution (monomer solution) was prepared, and then the ethanol solution was applied to the entire upper surface of the conductive resin layer produced by the method described in Production Example 1 to form a coating film. By irradiating the coating film with ultraviolet rays at 600 mJ / cm 2 , an insulating resin layer having a thickness of 15 nm was formed on the entire upper surface of the conductive resin layer. Thereby, a current collector provided with a conductive resin layer and an insulating resin layer was obtained (see FIG. 1).
(Example 2)
An insulating resin layer having a thickness of 18 nm is formed on the entire upper surface of the conductive resin layer in the same manner as in Example 1 except that an ethanol solution of 10% by weight of vinylene carbonate is used instead of the ethanol solution of 0.4% by weight of vinylene carbonate. And a current collector provided with a conductive resin layer and an insulating resin layer was obtained (see FIG. 1).
(Comparative Example 1)
The conductive resin layer manufactured by the method described in Preparation Example 1 without using an insulating resin layer was used as a current collector.
(Evaluation)
(Conductivity)
For the current collectors prepared in Examples 1 and 2 and Comparative Example 1, the volume resistivity of the conductive resin layer was determined using a resistivity meter (Loresta MCP-T360, manufactured by Mitsubishi Chemical Corporation) in accordance with JIS K 7194. The conductivity of the conductive resin layer was evaluated as follows.
○: Volume resistivity is 100 Ωcm or less ×: Volume resistivity exceeds 100 Ωcm (measurement of current density of current collector in negative electrode)
For the current collectors produced in Examples 1 and 2 and Comparative Example 1, the current density of the flowing current was measured in the negative electrode using a three-electrode cell (manufactured by Hosen). Specifically, the current density was measured 5 minutes after the start of voltage application at a constant voltage of 5 mV.
　比較例１で生じた電流密度を１とした場合の、実施例１および２の電流密度を相対値で示した。また、各相対値について、下記のように評価した。
○：電流密度相対値が０．５以下である
×：電流密度相対値が０．５を超過する
　実施例１、２および比較例１の集電体の処方、導電性および電流密度の測定結果と評価とを表１に示す。 When the current density generated in Comparative Example 1 is 1, the current densities of Examples 1 and 2 are shown as relative values. Further, each relative value was evaluated as follows.
○: Current density relative value is 0.5 or less ×: Current density relative value exceeds 0.5 Prescription of current collectors of Examples 1 and 2 and Comparative Example 1, conductivity and current density measurement results Table 1 shows the evaluation.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　なお、上記発明は、本発明の例示の実施形態として提供したが、これは単なる例示に過ぎず、限定的に解釈してはならない。当該技術分野の当業者によって明らかな本発明の変形例は、後記請求の範囲に含まれる。 Although the above invention has been provided as an exemplary embodiment of the present invention, this is merely an example and should not be interpreted in a limited manner. Variations of the present invention that are apparent to one of ordinary skill in the art are within the scope of the following claims.
　集電体は、リチウムイオン二次電池に用いられる。 The current collector is used for a lithium ion secondary battery.
１　　　集電体
６　　　導電樹脂層
７　　　バイポーラ電池
１０　　電極
１１　　電解質層
１４　　正極
１５　　負極
１９　　絶縁樹脂層 DESCRIPTION OF SYMBOLS 1 Current collector 6 Conductive resin layer 7 Bipolar battery 10 Electrode 11 Electrolyte layer 14 Positive electrode 15 Negative electrode 19 Insulating resin layer

Claims (6)

  1. 　樹脂および導電性材料を含む導電樹脂層と、
    　前記導電樹脂層の厚み方向一方面に形成され、厚みが１ｎｍ以上１μｍ以下である絶縁樹脂層とを備えることを特徴とする、集電体。     A conductive resin layer containing a resin and a conductive material;
    A current collector comprising: an insulating resin layer formed on one surface in the thickness direction of the conductive resin layer and having a thickness of 1 nm to 1 μm.
  2. 　前記絶縁樹脂層が、ポリカーボネート樹脂を含むことを特徴とする、請求項１に記載の集電体。 The current collector according to claim 1, wherein the insulating resin layer includes a polycarbonate resin.
  3. 　前記樹脂が、ポリイミドおよび／またはポリアミドイミドを含むことを特徴とする、請求項１に記載の集電体。 The current collector according to claim 1, wherein the resin contains polyimide and / or polyamideimide.
  4. 　前記導電性材料が、ニッケルおよび／またはステンレスを含むことを特徴とする、請求項１に記載の集電体。 The current collector according to claim 1, wherein the conductive material includes nickel and / or stainless steel.
  5. 　互いに間隔を隔てて複数設けられる電極と、
    　各前記電極間に配置される電解質層とを備えるバイポーラ電池であり、
    　前記複数の電極の少なくとも一つは、
    　　請求項１～４のいずれか一項に記載の集電体と、
    　　前記集電体の厚み方向一方面に積層される正極と、
    　　前記集電体の厚み方向他方面に積層される負極とを備え、
    　前記集電体の絶縁樹脂層が、前記負極と前記導電樹脂層との間に介在されていることを特徴とする、バイポーラ電池。     A plurality of electrodes spaced apart from each other;
    A bipolar battery comprising an electrolyte layer disposed between the electrodes,
    At least one of the plurality of electrodes is
    A current collector according to any one of claims 1 to 4;
    A positive electrode laminated on one surface in the thickness direction of the current collector;
    A negative electrode laminated on the other side in the thickness direction of the current collector,
    A bipolar battery, wherein an insulating resin layer of the current collector is interposed between the negative electrode and the conductive resin layer.
  6. 　リチウムイオン二次電池として用いられることを特徴とする、請求項５に記載のバイポーラ電池。 The bipolar battery according to claim 5, wherein the bipolar battery is used as a lithium ion secondary battery.
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