WO2022202578A1 - Electrochemical device - Google Patents

Electrochemical device Download PDF

Info

Publication number
WO2022202578A1
WO2022202578A1 PCT/JP2022/012118 JP2022012118W WO2022202578A1 WO 2022202578 A1 WO2022202578 A1 WO 2022202578A1 JP 2022012118 W JP2022012118 W JP 2022012118W WO 2022202578 A1 WO2022202578 A1 WO 2022202578A1
Authority
WO
WIPO (PCT)
Prior art keywords
positive electrode
negative electrode
electrochemical device
active material
lithium
Prior art date
Application number
PCT/JP2022/012118
Other languages
French (fr)
Japanese (ja)
Inventor
英郎 坂田
菜穂 松村
秀樹 島本
良太 森岡
宏樹 林
Original Assignee
パナソニックＩｐマネジメント株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by パナソニックＩｐマネジメント株式会社 filed Critical パナソニックＩｐマネジメント株式会社
Priority to JP2023509086A priority Critical patent/JPWO2022202578A1/ja
Publication of WO2022202578A1 publication Critical patent/WO2022202578A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/04—Hybrid capacitors
    • H01G11/06—Hybrid capacitors with one of the electrodes allowing ions to be reversibly doped thereinto, e.g. lithium ion capacitors [LIC]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/22—Electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/22—Electrodes
    • H01G11/30—Electrodes characterised by their material
    • H01G11/32—Carbon-based
    • H01G11/36—Nanostructures, e.g. nanofibres, nanotubes or fullerenes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/22—Electrodes
    • H01G11/30—Electrodes characterised by their material
    • H01G11/48—Conductive polymers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0568—Liquid materials characterised by the solutes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/60—Selection of substances as active materials, active masses, active liquids of organic compounds
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers

Definitions

  • the present invention relates to an electrochemical device containing a conductive polymer in the positive electrode.
  • an active material layer containing electrochemically active polymer particles having an average particle size of more than 0.5 ⁇ m and 20 ⁇ m or less and a conductive aid, a current collector, and an active material layer disclosed is a positive electrode for a power storage device comprising a conductive layer disposed between and a current collector and containing a carbon material and in contact with the active material layer and the current collector.
  • a conductive layer disposed between and a current collector and containing a carbon material and in contact with the active material layer and the current collector.
  • Methyl cellulose, hydroxyethyl cellulose, polyethylene oxide, carboxymethyl cellulose, derivatives thereof, salts thereof, polyolefins, natural rubbers, synthetic rubbers, and thermoplastic elastomers are exemplified as binders used in the conductive layer.
  • Patent Document 2 describes a positive electrode in a non-aqueous electrolyte secondary battery containing polyaniline and containing a polymer such as polyacrylic acid having a carboxyl group in the molecule as a binder.
  • electrochemical devices For automotive applications, electrochemical devices with a wide operating temperature range of, for example, -30 to 85°C are required. That is, electrochemical devices are required to have excellent low-temperature properties and float properties.
  • electrochemical devices are required to have excellent low-temperature properties and float properties.
  • the internal resistance (DCR) tends to be greater at low temperatures than at room temperature.
  • the capacitance tends to decrease.
  • one aspect of the present invention includes a positive electrode, a negative electrode and a lithium ion conductive electrolyte, the positive electrode having a positive electrode material layer comprising a positive electrode active material and a binder, the positive electrode active material comprising: A conductive polymer capable of reversibly doping and dedoping at least anions is included, the negative electrode includes a negative electrode active material capable of reversibly doping and dedoping lithium ions, and the binder is a polyalkylene oxide and derivatives thereof.
  • the low temperature characteristics and float characteristics of electrochemical devices are improved.
  • FIG. 1 is a vertical cross-sectional view showing the configuration of an electrochemical device according to one embodiment of the present invention.
  • the electrochemical device includes a positive electrode, a negative electrode, and a lithium ion conductive electrolyte (electrolytic solution).
  • the positive electrode has a positive electrode material layer containing a positive electrode active material and a binder.
  • the positive electrode active material is capable of reversibly doping and dedoping at least anions.
  • the positive electrode active material contains a conductive polymer.
  • the negative electrode includes a negative electrode active material capable of reversibly doping and dedoping lithium ions.
  • the binder contains at least one selected from the group consisting of polyalkylene oxides and derivatives thereof (hereinafter referred to as "polyalkylene oxide compound").
  • Anions and lithium ions are doped into the positive and negative electrodes, respectively, when the electrochemical device is charged. During discharge of the electrochemical device, anions and lithium ions dedope from the positive and negative electrodes, respectively.
  • the doping of the positive electrode active material with the anion includes at least the phenomenon of adsorption of the anion to the positive electrode active material, and is a concept that can also include absorption of the anion by the positive electrode active material, chemical interaction between the positive electrode active material and the anion, and the like. be.
  • the positive electrode may be a polarizable electrode, or may be an electrode that has the properties of a polarizable electrode and in which the Faraday reaction also contributes to the capacity.
  • the doping of lithium ions into the negative electrode active material includes at least the absorption phenomenon of lithium ions into the negative electrode active material, such as the adsorption of lithium ions to the negative electrode active material and the chemical interaction between the negative electrode active material and lithium ions. It is a concept that can also include
  • Capacity develops as the Faraday reaction, in which lithium ions are occluded into the negative electrode active material, progresses. That is, the electrochemical device has intermediate performance between the lithium ion secondary battery and the electric double layer capacitor, and resembles the lithium ion capacitor.
  • the positive electrode active material is an electrochemical device containing activated carbon
  • the activated carbon is different from the material contained in the positive electrode of a general lithium ion secondary battery (for example, ceramic particles such as lithium transition metal oxide). , tend to be highly hydrophobic.
  • the positive electrode material layer can be formed, for example, by applying slurry in which a positive electrode active material, a binder, and, if necessary, a conductive aid are dispersed in a dispersion medium, followed by drying. Water can be used as the dispersion medium.
  • a positive electrode active material which is the positive electrode active material
  • the conductive polymer aggregates in the positive electrode material layer, and the internal resistance may increase.
  • the distribution of the conductive polymer in the positive electrode material layer is not uniform, the electrochemical reaction at the positive electrode also occurs unevenly. For these reasons, it is believed that the low temperature properties and float properties of the electrochemical device are degraded.
  • the polyalkylene oxide compound acts as a surfactant and can uniformly disperse the conductive polymer in the slurry.
  • the distribution of the conductive polymer in the positive electrode material layer becomes uniform, and deterioration of the low-temperature characteristics and float characteristics of the electrochemical device can be suppressed.
  • Polyalkylene oxide compounds include polyalkylene oxides and derivatives thereof.
  • Derivatives of polyalkylene oxide include salts of polyalkylene oxide, ethers in which hydrogen atoms in at least one terminal hydroxyl group of polyalkylene oxide are substituted with hydrocarbon groups, and hydrogen atoms in at least one terminal hydroxyl group of polyalkylene oxide.
  • An ester substituted with an acyl group and the like are included.
  • the polyalkylene oxide compound may be, for example, a compound having a structure represented by the chemical formula X 1 O—[R 1 O] n —X 2 .
  • X1 is a hydrogen atom, an alkali metal, a hydrocarbon group or an acyl group.
  • X2 is a hydrogen atom, an alkali metal, a hydrocarbon group or an acyl group.
  • R 1 constituting the repeating unit of the polymer is an alkylene group.
  • R 1 may be an alkylene group having 2 to 4 carbon atoms.
  • R 1 in some repeating units may be different from R 1 in other repeating units.
  • Some of the hydrogen atoms in the hydrocarbon groups and acyl groups in X 1 and X 2 may be substituted with other functional groups (eg, halogen atoms, cyano groups, amino groups, hydroxyl groups, etc.).
  • polyalkylene oxide examples include polyethylene oxide, polypropylene oxide, polybutylene oxide, ethylene oxide-propylene oxide copolymer, and ethylene oxide-butylene oxide copolymer. Among these, polyethylene oxide is most preferred.
  • the repeating number n of the monomer (alkylene group) in the polyalkylene oxide compound may be, for example, 2,000 or more and 200,000 or less when the polyalkylene oxide is polyethylene oxide.
  • the molecular weight (weight average molecular weight) of the polyethylene oxide compound may be, for example, 100,000 or more and 10,000,000 or less.
  • the repeating number n may be, for example, 70 or more and 100 or less.
  • the molecular weight (weight average molecular weight) of the polypropylene oxide compound may be, for example, 4,000 or more and 6,000 or less.
  • polyalkylene oxide compounds include ether bodies such as polyoxyalkylene alkyl ethers such as polyoxyethylene alkyl ethers, and polyoxyalkylene aryl ethers such as polyoxyethylene alkylphenyl ethers.
  • esters include polyoxyethylene fatty acid esters.
  • Compounds (eg, X 2 OH) that can be used to form the ether form include alcohol compounds, phenol compounds, and the like.
  • Alcohol compounds include methanol, ethanol, propanol, butanol, pentanol, hexanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, Linear alkyl alcohols such as nonadecanol, eicosanol, heneicosanol, docosanol, tricosanol, tetracosanol, pentacosanol, hexacosanol, heptacosanol, octacosanol, nonacosanol, triacontanol; isopropanol, isobutanol, isohexanol, 2 - eth
  • Phenol compounds include phenol, alkylphenol, monostyrenated phenol, distyrenated phenol, tristyrenated phenol and the like. Among them, a chain higher alcohol having 10 to 20 carbon atoms is desirable, and the higher alcohol may have 11 to 17 carbon atoms, or 11 to 15 (further 12 to 13) carbon atoms.
  • Compounds that can be used to form esters include stearic acid, isostearic acid, oleic acid, and lauric acid.
  • 60% or more or 80% or more of the repeating structure of the monomer may be an ethylene oxide unit structure (—C 2 H 4 O—), and 90% or more may be an ethylene oxide unit structure (—C 2 H 4 O—).
  • the polyalkylene oxide compound has substantially no carboxyl groups (COOH or COO ⁇ ).
  • a polymer compound having a carboxyl group forms a three-dimensional network structure through the hydrophilic carboxyl groups, and easily incorporates a large number of water molecules into the network structure to form a gel structure. For this reason, moisture that is not removed even by drying the slurry remains in the positive electrode material layer, which may deteriorate the low-temperature characteristics and float characteristics of the electrochemical device.
  • a polyalkylene oxide compound that does not substantially have a carboxyl group it is possible to suppress deterioration of low-temperature characteristics and float characteristics.
  • the polyalkylene oxide compound substantially does not have a carboxyl group means that the ratio of the mass of the carboxyl group (COOH or COO ⁇ ) to the total mass of the polyalkylene oxide compound is 0.01% or less. Say. It means that the number of carboxyl groups contained in the polyalkylene oxide compound is 0.2 or less per molecule of the polyalkylene oxide compound.
  • the content of the polyalkylene oxide compound contained in the positive electrode material layer may be 1% by mass or more and 9% by mass or less, or 1% by mass or more and 5% by mass or less with respect to the total mass of the positive electrode material layer. There may be.
  • the content of the polyalkylene oxide compound is in the range of 1% by mass or more and 9% by mass or less, the effect of suppressing deterioration of low-temperature characteristics and float characteristics is sufficiently exhibited.
  • a binder other than the polyalkylene oxide compound may be contained in the positive electrode material layer. That is, a binder other than the polyalkylene oxide compound may be used in combination with the polyalkylene oxide compound.
  • Preferred binders that can be combined with polyalkylene oxide compounds are styrene-butadiene rubber (SBR) and polytetrafluoroethylene (PTFE).
  • the positive electrode material layer may further contain a conductive aid.
  • the conductive aid may contain at least one selected from the group consisting of carbon black and carbon nanotubes. Since carbon black and carbon nanotubes are highly hydrophobic, it is difficult to evenly disperse them in the slurry. However, by including the polyalkylene oxide compound in the slurry, carbon black and/or carbon nanotubes can be uniformly dispersed in the slurry. As a result, the distribution of the conductive additive in the positive electrode material layer becomes uniform, and deterioration of the low-temperature characteristics and float characteristics of the electrochemical device can be suppressed.
  • polyaniline compounds facilitate anion doping and dedoping. Therefore, the conductive polymer desirably contains at least a polyaniline compound.
  • Polyaniline compounds include polyaniline, polyaniline derivatives, polymers of aniline derivatives, and the like. Examples of polyaniline derivatives include derivatives in which an alkyl group such as a methyl group is added to a portion of the benzene ring of the aniline unit, and derivatives in which a halogen group or the like is added to a portion of the benzene ring of the aniline unit.
  • Polyaniline compounds are highly hydrophobic among conductive polymers, and it is difficult to disperse them uniformly in the slurry.
  • the polyalkylene oxide compound in the slurry, it is possible to uniformly disperse the polyaniline compound in the slurry.
  • the distribution of the conductive polymer in the positive electrode material layer becomes uniform, and deterioration of the low-temperature characteristics and float characteristics of the electrochemical device can be suppressed.
  • the negative electrode of the electrochemical device for example, the negative electrode used in lithium ion secondary batteries can be used.
  • a negative electrode contains, as a negative electrode active material, a carbonaceous material such as graphite, non-graphitizable carbon (hard carbon), and graphitizable carbon (soft carbon).
  • a carbonaceous material having a d value of 0.38 nm or more which indicates the interplanar spacing of the (002) plane obtained from the X-ray diffraction pattern, is preferable because high input/output is easily achieved.
  • Hard carbon may be used as the carbonaceous material having a d value of 0.38 nm or more.
  • part of the polyalkylene oxide compound contained in the positive electrode material layer may dissolve into the electrolytic solution.
  • the polyalkylene oxide compound eluted into the electrolytic solution also improves the affinity between the conductive polymer and the electrolytic solution and contributes to suppressing the increase in the internal resistance of the positive electrode. Therefore, it contributes to the improvement of low-temperature characteristics and float characteristics of electrochemical devices.
  • the polyalkylene oxide compound since the polyalkylene oxide compound has neither an anionic group nor a cationic group, it is not affected by the solute in the electrolytic solution, and is adsorbed to the positive electrode or the negative electrode during charging, and does not affect the charge-discharge reaction. I have nothing to give.
  • the lithium salt in the electrolyte is selected from the group consisting of lithium hexafluorophosphate ( LiPF6 ), lithium tetrafluoroborate ( LiBF4 ) and lithium bis(fluorosulfonyl)imide (LiN( SO2F)2 ) . It is desirable to include at least one of These lithium salts are highly stable and do not affect nonionic surfactants. Moreover, these lithium salts have a high degree of dissociation and are excellent in ionic conductivity. Among them, lithium bis(fluorosulfonyl)imide (hereinafter also referred to as LIFSI) is particularly preferred because of its high stability.
  • LIFSI lithium bis(fluorosulfonyl)imide
  • FIG. 1 is a vertical cross-sectional view schematically showing the configuration of an electrochemical device 200 according to one embodiment of the present invention.
  • the electrochemical device 200 includes an electrode assembly 100, an electrolytic solution (not shown), a bottomed metal cell case 210 that houses the electrode assembly 100 and the electrolytic solution, and a sealing plate that seals the opening of the cell case 210. 220.
  • the electrode body 100 is configured as a columnar wound body by, for example, winding a strip-shaped positive electrode 10 and a strip-shaped negative electrode 20 together with a separator 30 interposed therebetween.
  • the electrode body 100 may be configured as a laminate in which a plate-like positive electrode and a plate-like negative electrode are laminated with a separator interposed therebetween.
  • the positive electrode comprises a positive electrode core material and a positive electrode material layer supported by the positive electrode core material.
  • the negative electrode includes a negative electrode core material and a negative electrode material layer carried on the negative electrode core material.
  • a positive electrode active material containing at least a conductive polymer is included in the positive electrode material layer.
  • a negative electrode active material such as non-graphitizable carbon is included in the negative electrode material layer.
  • a gasket 221 is arranged on the peripheral edge of the sealing plate 220 , and the inside of the cell case 210 is sealed by crimping the opening end of the cell case 210 to the gasket 221 .
  • a positive electrode current collector plate 13 having a through hole 13h in the center is welded to the positive electrode core exposed portion 11x.
  • the other end of the tab lead 15 one end of which is connected to the positive collector plate 13 , is connected to the inner surface of the sealing plate 220 . Therefore, the sealing plate 220 functions as an external positive electrode terminal.
  • the negative electrode current collector plate 23 is welded to the negative electrode core exposed portion 21x.
  • the negative electrode current collector plate 23 is directly welded to a welding member provided on the inner bottom surface of the cell case 210 . Therefore, the cell case 210 functions as an external negative electrode terminal.
  • a sheet-like metal material is used for the positive electrode core material.
  • the sheet-shaped metal material may be a metal foil, a metal porous body, an etched metal, or the like. Aluminum, an aluminum alloy, nickel, titanium, etc. can be used as the metal material.
  • the thickness of the positive electrode core material is, for example, 10 to 100 ⁇ m.
  • a carbon layer may be formed on the positive electrode core material.
  • the carbon layer is interposed between the positive electrode core and the positive electrode material layer, for example, reduces the resistance between the positive electrode core and the positive electrode material layer, and improves current collection from the positive electrode material layer to the positive electrode core. It has the ability to improve
  • the carbon layer is formed, for example, by vapor-depositing a conductive carbon material on the surface of the positive electrode core material, or by forming a coating film of carbon paste containing the conductive carbon material, and drying the coating film.
  • Carbon paste includes, for example, a conductive carbon material, a polymer material, and water or an organic solvent.
  • the thickness of the carbon layer may be, for example, 1 to 20 ⁇ m.
  • Graphite, hard carbon, soft carbon, carbon black, and the like can be used as the conductive carbon material. Among them, carbon black can form a thin and highly conductive carbon layer. Fluorine resin, acrylic resin, polyvinyl chloride, styrene-butadiene rubber (SBR), and the like can be used as the polymer material.
  • the positive electrode material layer contains at least a conductive polymer as a positive electrode active material.
  • a ⁇ -conjugated polymer is preferably used as the conductive polymer. Examples of ⁇ -conjugated polymers that can be used include polyaniline compounds, polypyrrole compounds, polythiophene compounds, polyfuran compounds, polythiophenevinylene compounds, and polypyridine compounds.
  • each of the above “compounds” includes polyaniline, polypyrrole, polythiophene, polyfuran, polythiophene vinylene and polypyridine, as well as derivatives thereof.
  • Derivatives are polymers having polyaniline, polypyrrole, polythiophene, polyfuran, polythiophene vinylene, and polypyridine as basic skeletons.
  • Derivatives include, for example, derivatives in which an alkyl group such as a methyl group is added to part of the aromatic ring of each unit, derivatives in which a halogen group or the like is added to part of the aromatic ring of each unit, and the like.
  • polythiophene derivatives include poly(3,4-ethylenedioxythiophene) (PEDOT) and the like.
  • the conductive polymer may contain at least one of these, but preferably contains at least a polyaniline compound.
  • the content of the polyaniline compound contained in the conductive polymer is preferably 50% by mass or more, and may be 80% by mass or more, and 100% of the conductive polymer may be the polyaniline compound.
  • the weight average molecular weight of the conductive polymer is not particularly limited, but may be in the range of 1000 to 100000, for example.
  • the conductive polymer may contain dopants. By doping the ⁇ -electron conjugated polymer with a dopant, excellent conductivity is exhibited. Dopants include nitrate ion, phosphate ion, borate ion, benzenesulfonate ion, naphthalenesulfonate ion, toluenesulfonate ion, methanesulfonate ion (CF 3 SO 3 ⁇ ), perchlorate ion (ClO 4 ⁇ ), Tetrafluoroborate ion (BF 4 ⁇ ), hexafluorophosphate ion (PF 6 ⁇ ), fluorosulfate ion (FSO 3 ⁇ ), bis(fluorosulfonyl)imide ion (N(FSO 2 ) 2 ⁇ ), bis(trifluoromethanesulfonyl ) imide ion (N(CF 3 SO 2 ) 2
  • the dopant may be a polymer ion.
  • Polymer ions include polyvinylsulfonic acid, polystyrenesulfonic acid, polyallylsulfonic acid, polyacrylsulfonic acid, polymethacrylsulfonic acid, poly(2-acrylamido-2-methylpropanesulfonic acid), polyisoprenesulfonic acid, polyacrylic Examples include ions such as acids. These may be homopolymers or copolymers of two or more monomers. These may be used alone or in combination of two or more.
  • a conductive polymer is synthesized, for example, by performing electrolytic polymerization or chemical polymerization in a reaction solution containing raw material monomers for the conductive polymer.
  • an oxidizing agent may be added to a reaction solution containing raw material monomers.
  • raw material monomers for the conductive polymer for example, aniline, pyrrole, thiophene, furan, thiophene vinylene, pyridine, or derivatives thereof can be used.
  • the raw material monomer may contain an oligomer.
  • Electropolymerization or chemical polymerization may be performed using a reaction solution containing a dopant.
  • the dopant used for electropolymerization or chemical polymerization need not be the same as the dopant constituting the electrochemical device.
  • sulfate ions may be dedoped. This makes it possible to increase the amount of anions doped into the conductive polymer during charging of the electrochemical device.
  • the positive electrode material layer (or in the electrolyte) may contain sulfate ions (SO 4 2 ⁇ ) at a rate of 1000 ppm or less. Even in such a case, the deterioration of the float characteristics can be suppressed by including the nonionic surfactant in the electrolytic solution.
  • SO 4 2 ⁇ sulfate ions
  • the positive electrode material layer contains a conductive polymer and a binder, and may contain a conductive material (conductive aid).
  • the binder binds the conductive polymer powder together to facilitate formation of the positive electrode material layer.
  • the positive electrode material layer may be formed by mixing a positive electrode material mixture with a dispersion medium to prepare a positive electrode paste, coating the positive electrode core material with the positive electrode paste, and then drying the coating film.
  • the positive electrode mixture contains a conductive polymer, and optionally contains a binder, a conductive material, and the like.
  • the dispersion medium may be water, a non-aqueous solvent such as alcohol, or a mixture thereof.
  • the thickness of the positive electrode material layer is not particularly limited, and may range, for example, from 10 ⁇ m to 300 ⁇ m.
  • the conductive polymer used for the positive electrode mixture may be particulate.
  • the average particle size of the conductive polymer particles may be, for example, 0.3 ⁇ m or more and 3.0 ⁇ m or less. As a result, a sufficient surface area of the conductive polymer can be secured, and anion doping and dedoping proceed more smoothly. Moreover, since the surface area of the conductive polymer is not excessively large, the conductive polymer is less likely to deteriorate.
  • the average particle size is the median diameter (D50) of 50% cumulative volume in the volume-based particle size distribution.
  • the average particle size may be analyzed by, for example, a laser diffraction/scattering method.
  • Examples of conductive materials include particulate carbon materials such as carbon black, fibrous carbon materials such as carbon fibers, carbon nanotubes, and carbon nanofibers.
  • Examples of carbon black include acetylene black, ketjen black, furnace black, and the like.
  • the binder contains the polyalkylene oxide compound described above.
  • a binder other than the polyalkylene oxide compound may be included in the positive electrode material layer.
  • Other binders include fluororesins, acrylic resins, rubber materials, cellulose derivatives, and the like.
  • the fluorine resin includes polyvinylidene fluoride, polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, and the like.
  • acrylic resins include polyacrylic acid and acrylic acid-methacrylic acid copolymers.
  • rubber materials include styrene-butadiene rubber. Carboxymethyl cellulose is mentioned as a cellulose derivative.
  • the content of the conductive polymer in the positive electrode material layer may be in the range of 60% by mass or more.
  • the content of the conductive material in the positive electrode material layer may be in the range of 1 to 30% by mass, or may be in the range of 5 to 15% by mass.
  • the content of the binder in the positive electrode material layer may be in the range of 1 to 10% by mass.
  • the content of the polyalkylene oxide compound in the positive electrode material layer may be in the range of 1 to 9 mass % or 1 to 5 mass %.
  • Nitative electrode core material A sheet-like metal material is used for the negative electrode core material.
  • the sheet-shaped metal material may be a metal foil, a metal porous body, an etched metal, or the like.
  • metal materials copper, copper alloys, nickel, stainless steel, and the like can be used.
  • the thickness of the negative electrode core material is, for example, 10 to 100 ⁇ m.
  • the negative electrode material layer includes, as a negative electrode active material, a material that electrochemically absorbs and releases lithium ions.
  • a negative electrode active material examples include carbonaceous materials, metallic compounds, alloys, and ceramic materials.
  • the carbonaceous material is preferable in that the potential of the negative electrode can be lowered.
  • the carbonaceous material graphite, hard carbon and soft carbon are preferred, and hard carbon is particularly preferred.
  • hard carbon having a d value of 0.38 nm or more on the (002) plane obtained from the X-ray diffraction pattern is preferable because it has a lower resistance and a higher capacity than graphite.
  • the negative electrode material layer may be formed, for example, by mixing a negative electrode mixture with a dispersion medium to prepare a negative electrode paste, applying the negative electrode paste to the negative electrode core material, and then drying the coating film.
  • the negative electrode mixture contains a negative electrode active material, and may optionally contain a binder, a conductive material, and the like.
  • the conductive material and binder for example, the materials exemplified for the positive electrode can be used.
  • the dispersion medium for example, the materials exemplified for the positive electrode paste can be used.
  • the thickness of the negative electrode material layer is not particularly limited, and may be in the range of 10 ⁇ m to 300 ⁇ m, for example.
  • Pre-doping of lithium ions to the negative electrode is performed, for example, by forming a metallic lithium layer as a lithium ion supply source on the surface of the negative electrode material layer, and impregnating the negative electrode having the metallic lithium layer with an electrolytic solution having lithium ion conductivity. Proceed by At this time, lithium ions are eluted from the metal lithium layer into the non-aqueous electrolyte, and the eluted lithium ions are occluded by the negative electrode active material. For example, when graphite or hard carbon is used as the negative electrode active material, lithium ions are inserted between the graphite layers or in the pores of the hard carbon.
  • the amount of pre-doped lithium ions can be controlled by the mass of the metallic lithium layer.
  • the amount of lithium to be pre-doped may be, for example, about 50% to 95% of the maximum amount that can be occluded in the negative electrode material layer.
  • the step of pre-doping the negative electrode with lithium ions may be performed before assembling the electrode body, or the pre-doping may proceed after housing the electrode body together with the electrolytic solution in the case of the electrochemical device.
  • a cellulose fiber nonwoven fabric As the separator, a cellulose fiber nonwoven fabric, a glass fiber nonwoven fabric, a polyolefin microporous film, a woven fabric or a nonwoven fabric, or the like can be used.
  • the thickness of the separator is, for example, 10-300 ⁇ m, preferably 10-40 ⁇ m.
  • the electrolyte has lithium ion conductivity.
  • the electrolyte contains a non-aqueous solvent, a lithium salt, and a nonionic surfactant.
  • a lithium salt is a salt of a lithium ion and an anion, and the anion derived from the lithium salt is doped into the positive electrode during charging of the electrochemical device.
  • Lithium salts include, for example, LIFSI , LiClO4, LiBF4 , LiPF6 , LiAlCl4 , LiSbF6 , LiSCN , LiCF3SO3 , LiFSO3 , LiCF3CO2 , LiAsF6 , LiB10Cl10 , LiCl , LiBr , LiI, LiBCl 4 , LiN(CF 3 SO 2 ) 2 and the like. These may be used individually by 1 type, or may be used in combination of 2 or more type. Among them, it is desirable to use at least one selected from the group consisting of LIFSI, LiPF 6 and LiBF 4 .
  • the non-aqueous solvent is not particularly limited and can be appropriately selected according to the purpose.
  • Additives may be added to the electrolytic solution as necessary.
  • an unsaturated carbonate such as vinylene carbonate, vinylethylene carbonate, or divinylethylene carbonate may be used as an additive that forms a film having high lithium ion conductivity on the surface of the negative electrode.
  • cylindrical wound electrochemical device was exemplified, but the scope of application of the present invention is not limited to the above, and it is also applicable to rectangular wound and laminated electrochemical devices. be able to.
  • a conductive polymer as a positive electrode active material, a dispersion of carbon black as a conductive material, a dispersion of styrene-butadiene rubber (SBR) as a binder, and a solution of polyethylene oxide (PEO) (weight average molecular weight: 600,000). were mixed to prepare a positive electrode paste.
  • the mixing ratios of the conductive polymer, carbon black, styrene-butadiene rubber (SBR), and polyethylene oxide (PEO) in the positive electrode paste were set to mass % shown in Table 1, respectively.
  • the positive electrode paste is applied to both sides of the positive electrode core material, the coating film is heated with a hot plate at about 60 to 90 ° C., pressurized with a roll press, and further vacuum-dried at 110 ° C. for 12 hours.
  • a positive electrode having positive electrode material layers with a thickness of 30 ⁇ m on both sides was obtained.
  • Polyaniline particles with an average particle size (D50) of 3 ⁇ m were used as the conductive polymer.
  • the carbon black dispersion liquid is composed of carbon black and water, and the mass ratio of carbon black:water is 20:80.
  • Acetylene black (AB) was used as carbon black.
  • a copper foil having a thickness of 20 ⁇ m was prepared as a negative electrode core material.
  • a negative electrode paste containing a negative electrode mixture and water at a weight ratio of 40:60 was prepared.
  • the negative electrode mixture is a mixed powder of 90 parts by mass of hard carbon, 5 parts by mass of Ketjenblack, 1.5 parts by mass of carboxycellulose, and 3 parts by mass of styrene-butadiene rubber.
  • the negative electrode paste was applied to both sides of the negative electrode core material, and the coating film was dried to obtain a negative electrode having negative electrode material layers having a thickness of 35 ⁇ m on both sides.
  • a conductive polymer as a positive electrode active material a carbon black dispersion as a conductive material, a styrene-butadiene rubber (SBR) dispersion as a binder, and a carboxymethyl cellulose (CMC) solution are mixed.
  • positive electrode paste was prepared.
  • the mixing ratio of the conductive polymer, carbon black, styrene-butadiene rubber (SBR), and carboxymethyl cellulose (CMC) in the positive electrode paste was 75:15:7:3 in mass ratio.
  • the conductive polymer of the positive electrode active material, the carbon black dispersion of the conductive material, the styrene-butadiene rubber (SBR) dispersion of the binder, and the polyacrylic acid (PAA) solution are mixed.
  • a positive electrode paste was prepared.
  • the mixing ratio of the conductive polymer, carbon black, styrene-butadiene rubber (SBR), and polyacrylic acid (PAA) in the positive electrode paste was 75:15:7:3 by mass.
  • the PAA solution was composed of PAA and water, and the mass ratio of PAA:water was 5:95.
  • a conductive polymer as a positive electrode active material a carbon black dispersion as a conductive material, a polyacrylic acid (PAA) solution as a binder, and a carboxymethyl cellulose (CMC) solution are mixed to form a positive electrode.
  • a paste was prepared. The mixing ratio of the conductive polymer, carbon black, polyacrylic acid (PAA) and carboxymethyl cellulose (CMC) in the positive electrode paste was 75:15:7:3 in mass ratio.
  • the PAA solution was composed of PAA and water, and the mass ratio of PAA:water was 5:95.
  • the obtained electrochemical devices (cells A1 to A7 and B1 to B3) were evaluated by the following method.
  • the rate of change of the capacity after continuous charging with respect to the capacity C0 before continuous charging (initial) was calculated by C1 / C0 .
  • a larger rate of change (closer to 1) means better float characteristics.
  • Table 1 shows the evaluation results of low-temperature internal resistance and float characteristics.
  • the composition of the positive electrode in each electrochemical device (cells A1 to A7 and B1 to B3) (the content ratio of the conductive polymer polyaniline, the conductive aid acetylene black, and the binder) is also shown. are shown.
  • the low-temperature internal resistance is shown as a relative value with the internal resistance of the cell B1 of Comparative Example 1 set to 100.
  • the float characteristics are shown as relative values, with the rate of change of the capacity of the cell B1 of Comparative Example 1 being 100.
  • cells A1 to A7 are examples, and cells B1 to B3 are comparative examples.
  • the electrochemical device according to the present invention is excellent in low-temperature characteristics and float characteristics, so it is suitable as a power source (for example, a backup power source) for various uses.
  • Electrode body 10 Positive electrode 11x: Positive electrode core exposed part 13: Positive electrode current collector 15: Tab lead 20: Negative electrode 21x: Negative electrode core exposed part 23: Negative electrode current collector 30: Separator 200: Electrochemical device 210: Cell Case 220: Sealing plate 221: Gasket

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Power Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Inorganic Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Nanotechnology (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Secondary Cells (AREA)

Abstract

The present disclosure improves the low-temperature characteristics and the float characteristics of an electrochemical device; and this electrochemical device comprises a positive electrode, a negative electrode and a lithium ion-conductive electrolyte solution. With respect to this electrochemical device, the positive electrode comprises a positive electrode material layer that contains a positive electrode active material and a binder; the positive electrode active material contains a conductive polymer that is able to be reversibly doped and undoped at least with anions; the negative electrode contains a negative electrode active material that is able to be reversibly doped and undoped with lithium ions; and the binder contains at least one polyalkylene oxide compound that is selected from the group consisting of polyalkylene oxides and derivatives thereof.

Description

電気化学デバイスElectrochemical device
　本発明は、正極に導電性高分子を含む電気化学デバイスに関する。 The present invention relates to an electrochemical device containing a conductive polymer in the positive electrode.
　近年、リチウムイオン二次電池と電気二重層キャパシタの中間的な性能を有する電気化学デバイスが注目を集めている。 In recent years, attention has been focused on electrochemical devices that have intermediate performance between lithium-ion secondary batteries and electric double layer capacitors.
　特許文献１には、０．５μｍを超え２０μｍ以下の平均粒径を有する電気化学的に活性なポリマー粒子と導電助剤とを含有している活物質層と、集電体と、活物質層と集電体との間に配置され、カーボン材料を含み、活物質層及び集電体に接触している導電層と、を備えた蓄電デバイス用正極が開示されている。導電層に用いるバインダーとして、メチルセルロース、ヒドロキシエチルセルロース、ポリエチレンオキサイド、カルボキシメチルセルロース、これらの誘導体、これらの塩、ポリオレフィン、天然ゴム、合成ゴム、および熱可塑性エラストマーが例示されている。 In Patent Document 1, an active material layer containing electrochemically active polymer particles having an average particle size of more than 0.5 μm and 20 μm or less and a conductive aid, a current collector, and an active material layer disclosed is a positive electrode for a power storage device comprising a conductive layer disposed between and a current collector and containing a carbon material and in contact with the active material layer and the current collector. Methyl cellulose, hydroxyethyl cellulose, polyethylene oxide, carboxymethyl cellulose, derivatives thereof, salts thereof, polyolefins, natural rubbers, synthetic rubbers, and thermoplastic elastomers are exemplified as binders used in the conductive layer.
　特許文献２には、非水電解液二次電池において、ポリアニリンを含み、且つ、ポリアクリル酸などの分子中にカルボキシ基を持つポリマーをバインダーとして含む正極が記載されている。 Patent Document 2 describes a positive electrode in a non-aqueous electrolyte secondary battery containing polyaniline and containing a polymer such as polyacrylic acid having a carboxyl group in the molecule as a binder.
特開２０２０－７２２５３号公報JP 2020-72253 A 特許第５９９９９９５号明細書Patent No. 5999995
　自動車用途では、例えば－３０～８５℃の幅広い動作温度を有する電気化学デバイスが要求される。すなわち、電気化学デバイスには、優れた低温特性とフロート特性が要求される。一方、正極に導電性高分子を含む電気化学デバイスの場合、低温では常温と比較して、内部抵抗（ＤＣＲ）が大きくなりやすい。また、外部直流電源を用いて一定電圧を電気化学デバイスに印加するフロート充電を高温下で行う場合に、静電容量が低下しやすい。 For automotive applications, electrochemical devices with a wide operating temperature range of, for example, -30 to 85°C are required. That is, electrochemical devices are required to have excellent low-temperature properties and float properties. On the other hand, in the case of an electrochemical device containing a conductive polymer in the positive electrode, the internal resistance (DCR) tends to be greater at low temperatures than at room temperature. In addition, when performing float charging in which a constant voltage is applied to an electrochemical device using an external DC power source at high temperatures, the capacitance tends to decrease.
　上記に鑑み、本発明の一側面は、正極、負極およびリチウムイオン伝導性の電解質を含み、前記正極は、正極活物質および結着剤を含む正極材料層を有し、前記正極活物質は、少なくともアニオンを可逆的にドープおよび脱ドープ可能な導電性高分子を含み、前記負極は、リチウムイオンを可逆的にドープおよび脱ドープ可能な負極活物質を含み、前記結着剤は、ポリアルキレンオキシドおよびその誘導体からなる群より選択される少なくとも１種のポリアルキレンオキシド化合物を含む、電気化学デバイスに関する。 In view of the above, one aspect of the present invention includes a positive electrode, a negative electrode and a lithium ion conductive electrolyte, the positive electrode having a positive electrode material layer comprising a positive electrode active material and a binder, the positive electrode active material comprising: A conductive polymer capable of reversibly doping and dedoping at least anions is included, the negative electrode includes a negative electrode active material capable of reversibly doping and dedoping lithium ions, and the binder is a polyalkylene oxide and derivatives thereof.
　本発明によれば、電気化学デバイスの低温特性とフロート特性が改善される。 According to the present invention, the low temperature characteristics and float characteristics of electrochemical devices are improved.
図１は、本発明の一実施形態に係る電気化学デバイスの構成を示す縦断面図である。FIG. 1 is a vertical cross-sectional view showing the configuration of an electrochemical device according to one embodiment of the present invention.
　本実施形態に係る電気化学デバイスは、正極、負極およびリチウムイオン伝導性の電解質（電解液）を含む。正極は、正極活物質および結着剤を含む正極材料層を有する。正極活物質は、少なくともアニオンを可逆的にドープおよび脱ドープ可能である。正極活物質は、導電性高分子を含む。負極は、リチウムイオンを可逆的にドープおよび脱ドープ可能な負極活物質を含む。結着剤は、ポリアルキレンオキシドおよびその誘導体からなる群より選択される少なくとも１種（以下において、「ポリアルキレンオキシド化合物」と称する）を含む。 The electrochemical device according to this embodiment includes a positive electrode, a negative electrode, and a lithium ion conductive electrolyte (electrolytic solution). The positive electrode has a positive electrode material layer containing a positive electrode active material and a binder. The positive electrode active material is capable of reversibly doping and dedoping at least anions. The positive electrode active material contains a conductive polymer. The negative electrode includes a negative electrode active material capable of reversibly doping and dedoping lithium ions. The binder contains at least one selected from the group consisting of polyalkylene oxides and derivatives thereof (hereinafter referred to as "polyalkylene oxide compound").
　アニオンおよびリチウムイオンは、電気化学デバイスの充電時に、それぞれ正極および負極にドープされる。電気化学デバイスの放電時には、アニオンおよびリチウムイオンが、それぞれ正極および負極から脱ドープする。 Anions and lithium ions are doped into the positive and negative electrodes, respectively, when the electrochemical device is charged. During discharge of the electrochemical device, anions and lithium ions dedope from the positive and negative electrodes, respectively.
　アニオンの正極活物質へのドープとは、少なくとも正極活物質へのアニオンの吸着現象を含み、正極活物質によるアニオンの吸蔵や、正極活物質とアニオンとの化学的相互作用なども含み得る概念である。 The doping of the positive electrode active material with the anion includes at least the phenomenon of adsorption of the anion to the positive electrode active material, and is a concept that can also include absorption of the anion by the positive electrode active material, chemical interaction between the positive electrode active material and the anion, and the like. be.
　正極活物質にアニオンが吸着すると電気二重層が形成され、容量を発現する。正極は、分極性電極であってもよく、分極性電極の性質を有しつつファラデー反応も容量に寄与する電極であってもよい。 When anions are adsorbed on the positive electrode active material, an electric double layer is formed and capacity is developed. The positive electrode may be a polarizable electrode, or may be an electrode that has the properties of a polarizable electrode and in which the Faraday reaction also contributes to the capacity.
　リチウムイオンの負極活物質へのドープとは、少なくとも負極活物質へのリチウムイオンの吸蔵現象を含み、リチウムイオンの負極活物質への吸着や、負極活物質とリチウムイオンとの化学的相互作用なども含み得る概念である。 The doping of lithium ions into the negative electrode active material includes at least the absorption phenomenon of lithium ions into the negative electrode active material, such as the adsorption of lithium ions to the negative electrode active material and the chemical interaction between the negative electrode active material and lithium ions. It is a concept that can also include
　負極活物質にリチウムイオンが吸蔵されるファラデー反応が進行すると容量が発現する。すなわち、電気化学デバイスは、リチウムイオン二次電池と電気二重層キャパシタの中間的な性能を有し、リチウムイオンキャパシタに類似する。 Capacity develops as the Faraday reaction, in which lithium ions are occluded into the negative electrode active material, progresses. That is, the electrochemical device has intermediate performance between the lithium ion secondary battery and the electric double layer capacitor, and resembles the lithium ion capacitor.
　ここで、導電性高分子を正極活物質に用いる電気化学デバイスでは、低温特性とフロート特性が低下しやすい傾向がある。電気化学デバイスの低温特性とフロート特性が低下するのは、充電時に、正極活物質近傍の電解液が枯渇しやすく、正極の内部抵抗が増大するためであると推察される。導電性高分子は、疎水性が相当に高いため、電解液との親和性が低く、正極活物質近傍の電解液が枯渇しやすい。正極の内部抵抗が増大すると、電気化学デバイスの電圧が低下し、容量が減少する。低温では特に内部抵抗の増大が顕著になりやすい。また、正極活物質が活性炭を含む電気化学デバイスであっても、活性炭は、一般的なリチウムイオン二次電池の正極に含まれる材料（例えば、リチウム遷移金属酸化物などのセラミックス粒子）とは異なり、疎水性が高い傾向にある。 Here, in an electrochemical device that uses a conductive polymer as a positive electrode active material, low-temperature characteristics and float characteristics tend to deteriorate. It is presumed that the reason why the low-temperature characteristics and float characteristics of the electrochemical device are deteriorated is that the electrolyte solution in the vicinity of the positive electrode active material tends to be depleted during charging, and the internal resistance of the positive electrode increases. Since the conductive polymer has considerably high hydrophobicity, it has low affinity with the electrolytic solution, and the electrolytic solution in the vicinity of the positive electrode active material is easily depleted. As the internal resistance of the positive electrode increases, the voltage of the electrochemical device drops and the capacity decreases. Especially at low temperatures, the internal resistance tends to increase significantly. In addition, even if the positive electrode active material is an electrochemical device containing activated carbon, the activated carbon is different from the material contained in the positive electrode of a general lithium ion secondary battery (for example, ceramic particles such as lithium transition metal oxide). , tend to be highly hydrophobic.
　正極材料層は、例えば、正極活物質、結着剤、および、必要に応じで導電助剤を分散媒に分散させたスラリーを塗布後、乾燥させることにより形成され得る。分散媒としては、水が用いられ得る。しかしながら、正極活物質である導電性高分子は、疎水性が高いためにスラリー内で均一に分散させることが難しい。結果、正極材料層内において導電性高分子が凝集し、内部抵抗が増大する場合がある。また、正極材料層内において導電性高分子の分布が均一でないと、正極における電気化学反応も不均一に生じる。これらの理由により、電気化学デバイスの低温特性およびフロート特性が低下すると考えられる。 The positive electrode material layer can be formed, for example, by applying slurry in which a positive electrode active material, a binder, and, if necessary, a conductive aid are dispersed in a dispersion medium, followed by drying. Water can be used as the dispersion medium. However, it is difficult to uniformly disperse the conductive polymer, which is the positive electrode active material, in the slurry because of its high hydrophobicity. As a result, the conductive polymer aggregates in the positive electrode material layer, and the internal resistance may increase. Moreover, if the distribution of the conductive polymer in the positive electrode material layer is not uniform, the electrochemical reaction at the positive electrode also occurs unevenly. For these reasons, it is believed that the low temperature properties and float properties of the electrochemical device are degraded.
　これに対し、スラリーにポリアルキレンオキシド化合物を含ませることで、ポリアルキレンオキシド化合物は界面活性剤として作用し、導電性高分子をスラリー内で均一に分散させることができる。結果、正極材料層内における導電性高分子の分布も均一となり、電気化学デバイスの低温特性およびフロート特性の低下を抑制できる。 On the other hand, by including the polyalkylene oxide compound in the slurry, the polyalkylene oxide compound acts as a surfactant and can uniformly disperse the conductive polymer in the slurry. As a result, the distribution of the conductive polymer in the positive electrode material layer becomes uniform, and deterioration of the low-temperature characteristics and float characteristics of the electrochemical device can be suppressed.
　ポリアルキレンオキシド化合物は、ポリアルキレンオキシドおよびその誘導体を含む。ポリアルキレンオキシドの誘導体には、ポリアルキレンオキシドの塩、ポリアルキレンオキシドの末端の少なくとも一方の水酸基の水素が炭化水素基に置換されたエーテル体、ポリアルキレンオキシドの末端の少なくとも一方の水酸基の水素がアシル基に置換されたエステル体などが含まれる。 Polyalkylene oxide compounds include polyalkylene oxides and derivatives thereof. Derivatives of polyalkylene oxide include salts of polyalkylene oxide, ethers in which hydrogen atoms in at least one terminal hydroxyl group of polyalkylene oxide are substituted with hydrocarbon groups, and hydrogen atoms in at least one terminal hydroxyl group of polyalkylene oxide. An ester substituted with an acyl group and the like are included.
　ポリアルキレンオキシド化合物は、具体的に、例えば、化学式Ｘ１Ｏ－［Ｒ１Ｏ］ｎ－Ｘ２で表される構造を有する化合物であってもよい。Ｘ１は水素原子、アルカリ金属、炭化水素基またはアシル基である。Ｘ２は水素原子、アルカリ金属、炭化水素基またはアシル基である。ポリマーの繰り返し単位を構成するＲ１は、アルキレン基である。Ｒ１は、炭素数が２～４のアルキレン基であってもよい。一部の繰り返し単位におけるＲ１は、他の繰り返し単位におけるＲ１と異なっていてもよい。Ｘ１およびＸ２における炭化水素基およびアシル基の水素の一部が他の官能基（例えば、ハロゲン原子、シアノ基、アミノ基、水酸基など）で置換されていてもよい。 Specifically, the polyalkylene oxide compound may be, for example, a compound having a structure represented by the chemical formula X 1 O—[R 1 O] n —X 2 . X1 is a hydrogen atom, an alkali metal, a hydrocarbon group or an acyl group. X2 is a hydrogen atom, an alkali metal, a hydrocarbon group or an acyl group. R 1 constituting the repeating unit of the polymer is an alkylene group. R 1 may be an alkylene group having 2 to 4 carbon atoms. R 1 in some repeating units may be different from R 1 in other repeating units. Some of the hydrogen atoms in the hydrocarbon groups and acyl groups in X 1 and X 2 may be substituted with other functional groups (eg, halogen atoms, cyano groups, amino groups, hydroxyl groups, etc.).
　ポリアルキレンオキシドの具体例としては、ポリエチレンオキシド、ポリプロピレンオキシド、ポリブチレンオキシド、エチレンオキシド－プロピレンオキシド共重合体、エチレンオキシド－ブチレンオキシド共重合体などが挙げられる。これらのなかでも、ポリエチレンオキシドが最も好ましい。 Specific examples of polyalkylene oxide include polyethylene oxide, polypropylene oxide, polybutylene oxide, ethylene oxide-propylene oxide copolymer, and ethylene oxide-butylene oxide copolymer. Among these, polyethylene oxide is most preferred.
　ポリアルキレンオキシド化合物におけるモノマー（アルキレン基）の繰り返し数ｎは、ポリアルキレンオキシドがポリエチレンオキシドの場合、例えば２，０００以上２００，０００以下であってもよい。ポリエチレンオキシド化合物の分子量（重量平均分子量）は、例えば、１００，０００以上１０，０００，０００以下であってもよい。ポリアルキレンオキシドがポリプロピレンオキシドの場合、繰り返し数ｎは、例えば７０以上１００以下であってもよい。ポリプロピレンオキシド化合物の分子量（重量平均分子量）は、例えば、４，０００以上６，０００以下であってもよい。 The repeating number n of the monomer (alkylene group) in the polyalkylene oxide compound may be, for example, 2,000 or more and 200,000 or less when the polyalkylene oxide is polyethylene oxide. The molecular weight (weight average molecular weight) of the polyethylene oxide compound may be, for example, 100,000 or more and 10,000,000 or less. When the polyalkylene oxide is polypropylene oxide, the repeating number n may be, for example, 70 or more and 100 or less. The molecular weight (weight average molecular weight) of the polypropylene oxide compound may be, for example, 4,000 or more and 6,000 or less.
　ポリアルキレンオキシド化合物の具体例としては、エーテル体として、例えばポリオキシエチレンアルキルエーテル等のポリオキシアルキレンアルキルエーテル、ポリオキシエチレンアルキルフェニルエーテル等のポリオキシアルキレンアリールエーテル等が挙げられる。また、エステル体として、例えばポリオキシエチレン脂肪酸エステル等が挙げられる。エーテル体の形成に用い得る化合物（例えばＸ２ＯＨ）としては、アルコール化合物、フェノール化合物などが挙げられる。アルコール化合物としては、メタノール、エタノール、プロパノール、ブタノール、ペンタノール、ヘキサノール、オクタノール、ノナノール、デカノール、ウンデカノール、ドデカノール、トリデカノール、テトラデカノール、ペンタデカノール、ヘキサデカノール、ヘプタデカノール、オクタデカノール、ノナデカノール、エイコサノール、ヘンエイコサノール、ドコサノール、トリコサノール、テトラコサノール、ペンタコサノール、ヘキサコサノール、ヘプタコサノール、オクタコサノール、ノナコサノール、トリアコンタノール等の直鎖アルキルアルコール；イソプロパノール、イソブタノール、イソヘキサノール、２－エチルヘキサノール、イソノナノール、イソデカノール、イソトリデカノール、イソテトラデカノール、イソトリアコンタノール、イソヘキサデカノール、イソヘプタデカノール、イソオクタデカノール、イソノナデカノール、イソエイコサノール、イソヘンエイコサノール、イソドコサノール、イソトリコサノール、イソテトラコサノール、イソペンタコサノール、イソヘキサコサノール、イソヘプタコサノール、イソオクタコサノール、イソノナコサノール、イソペンタデカノール等の分岐アルキルアルコール；テトラデセノール、ヘキサデセノール、ヘプタデセノール、オクタデセノール、ノナデセノール等の直鎖アルケニルアルコール；イソヘキサデセノール、イソオクタデセノール等の分岐アルケニルアルコール；シクロペンタノール、シクロヘキサノール等の環状アルキルアルコール、ベンジルアルコール等の芳香族系アルコール等が挙げられる。フェノール化合物としては、フェノール、アルキルフェノール、モノスチレン化フェノール、ジスチレン化フェノール、トリスチレン化フェノール等が挙げられる。中でも炭素数１０～２０の鎖状の高級アルコールが望ましく、高級アルコールの炭素数は１１～１７でもよく、１１～１５（更には１２～１３）でもよい。エステル体の形成に用い得る化合物としては、ステアリン酸、イソステアリン酸、オレイン酸、ラウリン酸などが挙げられる。 Specific examples of polyalkylene oxide compounds include ether bodies such as polyoxyalkylene alkyl ethers such as polyoxyethylene alkyl ethers, and polyoxyalkylene aryl ethers such as polyoxyethylene alkylphenyl ethers. Examples of esters include polyoxyethylene fatty acid esters. Compounds (eg, X 2 OH) that can be used to form the ether form include alcohol compounds, phenol compounds, and the like. Alcohol compounds include methanol, ethanol, propanol, butanol, pentanol, hexanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, Linear alkyl alcohols such as nonadecanol, eicosanol, heneicosanol, docosanol, tricosanol, tetracosanol, pentacosanol, hexacosanol, heptacosanol, octacosanol, nonacosanol, triacontanol; isopropanol, isobutanol, isohexanol, 2 - ethylhexanol, isononanol, isodecanol, isotridecanol, isotetradecanol, isotriacontanol, isohexadecanol, isoheptadecanol, isooctadecanol, isononadecanol, isoeicosanol, isohane Branched alkyl alcohols such as eicosanol, isodocosanol, isotricosanol, isotetracosanol, isopentacosanol, isohexacosanol, isoheptacosanol, isooctacsanol, isononacosanol, isopentadecanol; Straight-chain alkenyl alcohols such as tetradecenol, hexadecenol, heptadecenol, octadecenol and nonadecenol; branched alkenyl alcohols such as isohexadecenol and isooctadecenol; cyclic alkyl alcohols such as cyclopentanol and cyclohexanol; fragrances such as benzyl alcohol family alcohols and the like. Phenol compounds include phenol, alkylphenol, monostyrenated phenol, distyrenated phenol, tristyrenated phenol and the like. Among them, a chain higher alcohol having 10 to 20 carbon atoms is desirable, and the higher alcohol may have 11 to 17 carbon atoms, or 11 to 15 (further 12 to 13) carbon atoms. Compounds that can be used to form esters include stearic acid, isostearic acid, oleic acid, and lauric acid.
　ポリアルキレンオキシド化合物において、モノマーの繰り返し構造の６０％以上もしくは８０％以上がエチレンオキシドの単位構造（－Ｃ２Ｈ４Ｏ－）であってもよく、９０％以上がエチレンオキシドの単位構造（－Ｃ２Ｈ４Ｏ－）であることが好ましい。 In the polyalkylene oxide compound, 60% or more or 80% or more of the repeating structure of the monomer may be an ethylene oxide unit structure (—C 2 H 4 O—), and 90% or more may be an ethylene oxide unit structure (—C 2 H 4 O—).
　ポリアルキレンオキシド化合物は、カルボキシル基（ＣＯＯＨまたはＣＯＯ－）を実質的に有さないことが好ましい。カルボキシル基を有するポリマー化合物は、親水性のカルボキシル基を介して３次元網目構造を形成し、網目構造に多数の水分子を取り込んでゲル構造を作り易い。このため、スラリーの乾燥によっても除去されない水分が正極材料層中に残存し、電気化学デバイスの低温特性およびフロート特性を低下させる場合がある。カルボキシル基を実質的に有さないポリアルキレンオキシド化合物を用いることで、低温特性およびフロート特性の低下を抑制できる。なお、ポリアルキレンオキシド化合物がカルボキシル基を実質的に有さないとは、ポリアルキレンオキシド化合物の質量の全体に占めるカルボキシル基（ＣＯＯＨまたはＣＯＯ－）の質量の割合が０．０１％以下であることをいう。ポリアルキレンオキシド化合物に含まれるカルボキシル基の数が、ポリアルキレンオキシド化合物の一分子当たり０．２以下であることをいう。 Preferably, the polyalkylene oxide compound has substantially no carboxyl groups (COOH or COO − ). A polymer compound having a carboxyl group forms a three-dimensional network structure through the hydrophilic carboxyl groups, and easily incorporates a large number of water molecules into the network structure to form a gel structure. For this reason, moisture that is not removed even by drying the slurry remains in the positive electrode material layer, which may deteriorate the low-temperature characteristics and float characteristics of the electrochemical device. By using a polyalkylene oxide compound that does not substantially have a carboxyl group, it is possible to suppress deterioration of low-temperature characteristics and float characteristics. Note that the polyalkylene oxide compound substantially does not have a carboxyl group means that the ratio of the mass of the carboxyl group (COOH or COO − ) to the total mass of the polyalkylene oxide compound is 0.01% or less. Say. It means that the number of carboxyl groups contained in the polyalkylene oxide compound is 0.2 or less per molecule of the polyalkylene oxide compound.
　正極材料層に含まれるポリアルキレンオキシド化合物の含有量は、正極材料層の質量の全体に対して１質量％以上、９質量％以下であってもよく、１質量％以上、５質量％以下であってもよい。ポリアルキレンオキシド化合物の含有量が１質量％以上９質量％以下の範囲であれば、低温特性およびフロート特性の低下を抑制する効果が十分に発揮される。 The content of the polyalkylene oxide compound contained in the positive electrode material layer may be 1% by mass or more and 9% by mass or less, or 1% by mass or more and 5% by mass or less with respect to the total mass of the positive electrode material layer. There may be. When the content of the polyalkylene oxide compound is in the range of 1% by mass or more and 9% by mass or less, the effect of suppressing deterioration of low-temperature characteristics and float characteristics is sufficiently exhibited.
　ポリアルキレンオキシド化合物以外の結着剤が正極材料層に含まれてもよい。すなわち、ポリアルキレンオキシド化合物以外の結着剤を、ポリアルキレンオキシド化合物と組み合わせて用いてもよい。ポリアルキレンオキシド化合物と組み合わせることのできる結着剤としては、スチレン－ブタジエンゴム（ＳＢＲ）およびポリテトラフルオロエチレン（ＰＴＦＥ）が好ましい。 A binder other than the polyalkylene oxide compound may be contained in the positive electrode material layer. That is, a binder other than the polyalkylene oxide compound may be used in combination with the polyalkylene oxide compound. Preferred binders that can be combined with polyalkylene oxide compounds are styrene-butadiene rubber (SBR) and polytetrafluoroethylene (PTFE).
　正極材料層は、導電助剤をさらに含み得る。導電助剤は、カーボンブラックおよびカーボンナノチューブからなる群より選択される少なくとも１種を含んでもよい。カーボンブラックおよびカーボンナノチューブは、疎水性が高いため、スラリー内に均一に分散させることが難しい。しかしながら、スラリーにポリアルキレンオキシド化合物を含ませることで、カーボンブラックおよび／またはカーボンナノチューブをスラリー内で均一に分散させることができる。これにより、正極材料層内における導電助剤の分布も均一となり、電気化学デバイスの低温特性およびフロート特性の低下を抑制できる。 The positive electrode material layer may further contain a conductive aid. The conductive aid may contain at least one selected from the group consisting of carbon black and carbon nanotubes. Since carbon black and carbon nanotubes are highly hydrophobic, it is difficult to evenly disperse them in the slurry. However, by including the polyalkylene oxide compound in the slurry, carbon black and/or carbon nanotubes can be uniformly dispersed in the slurry. As a result, the distribution of the conductive additive in the positive electrode material layer becomes uniform, and deterioration of the low-temperature characteristics and float characteristics of the electrochemical device can be suppressed.
　導電性高分子の中でも、ポリアニリン化合物は、アニオンのドープおよび脱ドープが容易に進行する。よって、導電性高分子は、少なくともポリアニリン化合物を含むことが望ましい。ポリアニリン化合物には、ポリアニリン、ポリアニリン誘導体、アニリン誘導体の重合体などが含まれる。ポリアニリン誘導体としては、例えば、アニリンユニットのベンゼン環の一部にメチル基などのアルキル基が付加された誘導体、アニリンユニットのベンゼン環の一部にハロゲン基等が付加された誘導体などが含まれる。 Among the conductive polymers, polyaniline compounds facilitate anion doping and dedoping. Therefore, the conductive polymer desirably contains at least a polyaniline compound. Polyaniline compounds include polyaniline, polyaniline derivatives, polymers of aniline derivatives, and the like. Examples of polyaniline derivatives include derivatives in which an alkyl group such as a methyl group is added to a portion of the benzene ring of the aniline unit, and derivatives in which a halogen group or the like is added to a portion of the benzene ring of the aniline unit.
　なお、ポリアニリンとは、アニリン（Ｃ６Ｈ５－ＮＨ２）をモノマーとし、Ｃ６Ｈ４－ＮＨ－Ｃ６Ｈ４－ＮＨ－のアミン構造単位、および／または、Ｃ６Ｈ４－Ｎ＝Ｃ６Ｈ４＝Ｎ－のイミン構造単位を有するポリマーを指す。 Note that polyaniline includes aniline (C 6 H 5 —NH 2 ) as a monomer, and has an amine structural unit of C 6 H 4 —NH—C 6 H 4 —NH— and/or C 6 H 4 —N= It refers to a polymer having an imine structural unit of C 6 H 4 =N-.
　ポリアニリン化合物は、導電性高分子の中でも疎水性が高く、スラリー内に均一に分散させることが難しい。しかしながら、スラリーにポリアルキレンオキシド化合物を含ませることで、ポリアニリン化合物をスラリー内で均一に分散させることが可能である。これにより、正極材料層内における導電性高分子の分布も均一となり、電気化学デバイスの低温特性およびフロート特性の低下を抑制できる。 Polyaniline compounds are highly hydrophobic among conductive polymers, and it is difficult to disperse them uniformly in the slurry. However, by including the polyalkylene oxide compound in the slurry, it is possible to uniformly disperse the polyaniline compound in the slurry. As a result, the distribution of the conductive polymer in the positive electrode material layer becomes uniform, and deterioration of the low-temperature characteristics and float characteristics of the electrochemical device can be suppressed.
　電気化学デバイスの負極には、例えば、リチウムイオン二次電池で用いられる負極を用いることができる。このような負極は、負極活物質として、例えば、黒鉛、難黒鉛化炭素（ハードカーボン）、易黒鉛化炭素（ソフトカーボン）のような炭素質材料を含む。中でも、高入出力を達成しやすい点で、Ｘ線回折パターンから得られる（００２）面の面間隔を示すｄ値が０．３８ｎｍ以上である炭素質材料が好ましい。ｄ値が０．３８ｎｍ以上である炭素質材料としてハードカーボンを用いてもよい。 For the negative electrode of the electrochemical device, for example, the negative electrode used in lithium ion secondary batteries can be used. Such a negative electrode contains, as a negative electrode active material, a carbonaceous material such as graphite, non-graphitizable carbon (hard carbon), and graphitizable carbon (soft carbon). Among them, a carbonaceous material having a d value of 0.38 nm or more, which indicates the interplanar spacing of the (002) plane obtained from the X-ray diffraction pattern, is preferable because high input/output is easily achieved. Hard carbon may be used as the carbonaceous material having a d value of 0.38 nm or more.
　製造後の電気化学デバイスにおいて、正極材料層に含まれるポリアルキレンオキシド化合物の一部は、電解液に溶出し得る。しかしながら、電解液に溶出したポリアルキレンオキシド化合物もまた、導電性高分子と電解液との親和性を向上させ、正極の内部抵抗の増大の抑制に寄与する。よって、電気化学デバイスの低温特性とフロート特性の改善に寄与する。加えて、ポリアルキレンオキシド化合物は、アニオン性基もカチオン性基も有さないため、電解液中の溶質の影響を受けず、充電時において、正極もしくは負極に吸着され、充放電反応に影響を与えることがない。 In the manufactured electrochemical device, part of the polyalkylene oxide compound contained in the positive electrode material layer may dissolve into the electrolytic solution. However, the polyalkylene oxide compound eluted into the electrolytic solution also improves the affinity between the conductive polymer and the electrolytic solution and contributes to suppressing the increase in the internal resistance of the positive electrode. Therefore, it contributes to the improvement of low-temperature characteristics and float characteristics of electrochemical devices. In addition, since the polyalkylene oxide compound has neither an anionic group nor a cationic group, it is not affected by the solute in the electrolytic solution, and is adsorbed to the positive electrode or the negative electrode during charging, and does not affect the charge-discharge reaction. I have nothing to give.
　電解液中のリチウム塩は、ヘキサフルオロリン酸リチウム（ＬｉＰＦ6）、テトラフルオロホウ酸リチウム（ＬｉＢＦ4）およびリチウムビス（フルオロスルホニル）イミド（ＬｉＮ（ＳＯ2Ｆ）2）からなる群より選択される少なくとも１種を含むことが望ましい。これらのリチウム塩は、安定性が高く、ノニオン性界面活性剤に対して影響を与えない。また、これらのリチウム塩は、解離度が高く、イオン伝導性に優れている。中でも、リチウムビス（フルオロスルホニル）イミド（以下、ＬＩＦＳＩとも称する。）は特に安定性が高く好ましい。 The lithium salt in the electrolyte is selected from the group consisting of lithium hexafluorophosphate ( LiPF6 ), lithium tetrafluoroborate ( LiBF4 ) and lithium bis(fluorosulfonyl)imide (LiN( SO2F)2 ) . It is desirable to include at least one of These lithium salts are highly stable and do not affect nonionic surfactants. Moreover, these lithium salts have a high degree of dissociation and are excellent in ionic conductivity. Among them, lithium bis(fluorosulfonyl)imide (hereinafter also referred to as LIFSI) is particularly preferred because of its high stability.
≪電気化学デバイス≫
　以下、本発明に係る電気化学デバイスの構成について、図面を参照しながら、より詳細に説明する。 ≪Electrochemical device≫
Hereinafter, the configuration of the electrochemical device according to the present invention will be described in more detail with reference to the drawings.
　図１は、本発明の一実施形態に係る電気化学デバイス２００の構成の概略を示す縦断面図である。電気化学デバイス２００は、電極体１００と、電解液（図示せず）と、電極体１００および電解液を収容する金属製の有底のセルケース２１０と、セルケース２１０の開口を封口する封口板２２０とを具備する。 FIG. 1 is a vertical cross-sectional view schematically showing the configuration of an electrochemical device 200 according to one embodiment of the present invention. The electrochemical device 200 includes an electrode assembly 100, an electrolytic solution (not shown), a bottomed metal cell case 210 that houses the electrode assembly 100 and the electrolytic solution, and a sealing plate that seals the opening of the cell case 210. 220.
　電極体１００は、例えば、それぞれ帯状の正極１０と負極２０とを、これらの間に介在するセパレータ３０とともに巻回することにより、柱状の巻回体として構成される。あるいは、電極体１００は、それぞれ板状の正極と負極とをセパレータを介して積層した積層体として構成してもよい。正極は、正極芯材および正極芯材に担持された正極材料層を具備する。負極は、負極芯材および負極芯材に担持された負極材料層を具備する。少なくとも導電性高分子を含む正極活物質は、正極材料層に含まれる。難黒鉛化炭素などの負極活物質は、負極材料層に含まれる。 The electrode body 100 is configured as a columnar wound body by, for example, winding a strip-shaped positive electrode 10 and a strip-shaped negative electrode 20 together with a separator 30 interposed therebetween. Alternatively, the electrode body 100 may be configured as a laminate in which a plate-like positive electrode and a plate-like negative electrode are laminated with a separator interposed therebetween. The positive electrode comprises a positive electrode core material and a positive electrode material layer supported by the positive electrode core material. The negative electrode includes a negative electrode core material and a negative electrode material layer carried on the negative electrode core material. A positive electrode active material containing at least a conductive polymer is included in the positive electrode material layer. A negative electrode active material such as non-graphitizable carbon is included in the negative electrode material layer.
　封口板２２０の周縁部にはガスケット２２１が配されており、セルケース２１０の開口端部をガスケット２２１にかしめることでセルケース２１０の内部が密閉されている。中央に貫通孔１３ｈを有する正極集電板１３は、正極芯材露出部１１ｘと溶接されている。正極集電板１３に一端が接続されているタブリード１５の他端は、封口板２２０の内面に接続されている。よって、封口板２２０は、外部正極端子としての機能を有する。一方、負極集電板２３は、負極芯材露出部２１ｘと溶接されている。負極集電板２３は、セルケース２１０の内底面に設けられた溶接用部材に直接溶接されている。よって、セルケース２１０は、外部負極端子としての機能を有する。 A gasket 221 is arranged on the peripheral edge of the sealing plate 220 , and the inside of the cell case 210 is sealed by crimping the opening end of the cell case 210 to the gasket 221 . A positive electrode current collector plate 13 having a through hole 13h in the center is welded to the positive electrode core exposed portion 11x. The other end of the tab lead 15 , one end of which is connected to the positive collector plate 13 , is connected to the inner surface of the sealing plate 220 . Therefore, the sealing plate 220 functions as an external positive electrode terminal. On the other hand, the negative electrode current collector plate 23 is welded to the negative electrode core exposed portion 21x. The negative electrode current collector plate 23 is directly welded to a welding member provided on the inner bottom surface of the cell case 210 . Therefore, the cell case 210 functions as an external negative electrode terminal.
＜正極＞
（正極芯材）
　正極芯材には、シート状の金属材料が用いられる。シート状の金属材料は、金属箔、金属多孔体、エッチングメタルなどであればよい。金属材料としては、アルミニウム、アルミニウム合金、ニッケル、チタンなどを用い得る。正極芯材の厚みは、例えば１０～１００μｍである。 <Positive electrode>
(Positive electrode core material)
A sheet-like metal material is used for the positive electrode core material. The sheet-shaped metal material may be a metal foil, a metal porous body, an etched metal, or the like. Aluminum, an aluminum alloy, nickel, titanium, etc. can be used as the metal material. The thickness of the positive electrode core material is, for example, 10 to 100 μm.
（カーボン層）
　正極芯材には、カーボン層を形成してもよい。カーボン層は、正極芯材と正極材料層との間に介在して、例えば、正極芯材と正極材料層との間の抵抗を低減し、正極材料層から正極芯材への集電性を向上させる機能を有する。 (carbon layer)
A carbon layer may be formed on the positive electrode core material. The carbon layer is interposed between the positive electrode core and the positive electrode material layer, for example, reduces the resistance between the positive electrode core and the positive electrode material layer, and improves current collection from the positive electrode material layer to the positive electrode core. It has the ability to improve
　カーボン層は、例えば、正極芯材の表面に導電性炭素材料を蒸着し、もしくは、導電性炭素材料を含むカーボンペーストの塗膜を形成し、塗膜を乾燥することで形成される。カーボンペーストは、例えば、導電性炭素材料と、高分子材料と、水または有機溶媒とを含む。カーボン層の厚みは、例えば１～２０μｍであればよい。導電性炭素材料には、黒鉛、ハードカーボン、ソフトカーボン、カーボンブラックなどを用い得る。中でも、カーボンブラックは、薄くて導電性に優れたカーボン層を形成し得る。高分子材料には、フッ素樹脂、アクリル樹脂、ポリ塩化ビニル、スチレン－ブタジエンゴム（ＳＢＲ）などを用い得る。 The carbon layer is formed, for example, by vapor-depositing a conductive carbon material on the surface of the positive electrode core material, or by forming a coating film of carbon paste containing the conductive carbon material, and drying the coating film. Carbon paste includes, for example, a conductive carbon material, a polymer material, and water or an organic solvent. The thickness of the carbon layer may be, for example, 1 to 20 μm. Graphite, hard carbon, soft carbon, carbon black, and the like can be used as the conductive carbon material. Among them, carbon black can form a thin and highly conductive carbon layer. Fluorine resin, acrylic resin, polyvinyl chloride, styrene-butadiene rubber (SBR), and the like can be used as the polymer material.
（正極材料層）
　正極材料層は、正極活物質として、少なくとも導電性高分子を含む。導電性高分子としては、π共役系高分子が好ましく用いられる。π共役系高分子としては、例えば、ポリアニリン化合物、ポリピロール化合物、ポリチオフェン化合物、ポリフラン化合物、ポリチオフェンビニレン化合物、ポリピリジン化合物などを用いることができる。 (Positive electrode material layer)
The positive electrode material layer contains at least a conductive polymer as a positive electrode active material. A π-conjugated polymer is preferably used as the conductive polymer. Examples of π-conjugated polymers that can be used include polyaniline compounds, polypyrrole compounds, polythiophene compounds, polyfuran compounds, polythiophenevinylene compounds, and polypyridine compounds.
　ここで、上記各「化合物」には、それぞれ、ポリアニリン、ポリピロール、ポリチオフェン、ポリフラン、ポリチオフェンビニレンおよびポリピリジンの他に、それらの誘導体が含まれる。誘導体とは、ポリアニリン、ポリピロール、ポリチオフェン、ポリフラン、ポリチオフェンビニレンおよびポリピリジンをそれぞれ基本骨格とする高分子である。誘導体としては、例えば、各ユニットの芳香環の一部にメチル基などのアルキル基が付加された誘導体、各ユニットの芳香環の一部にハロゲン基等が付加された誘導体などが含まれる。例えば、ポリチオフェン誘導体には、ポリ（３，４－エチレンジオキシチオフェン）（ＰＥＤＯＴ）などが含まれる。導電性高分子は、これらのうちの少なくとも１種を含めばよいが、少なくともポリアニリン化合物を含むことが望ましい。導電性高分子に含まれるポリアニリン化合物の含有量は５０質量％以上が好ましく、８０質量％以上でもよく、導電性高分子の１００％がポリアニリン化合物でもよい。 Here, each of the above "compounds" includes polyaniline, polypyrrole, polythiophene, polyfuran, polythiophene vinylene and polypyridine, as well as derivatives thereof. Derivatives are polymers having polyaniline, polypyrrole, polythiophene, polyfuran, polythiophene vinylene, and polypyridine as basic skeletons. Derivatives include, for example, derivatives in which an alkyl group such as a methyl group is added to part of the aromatic ring of each unit, derivatives in which a halogen group or the like is added to part of the aromatic ring of each unit, and the like. For example, polythiophene derivatives include poly(3,4-ethylenedioxythiophene) (PEDOT) and the like. The conductive polymer may contain at least one of these, but preferably contains at least a polyaniline compound. The content of the polyaniline compound contained in the conductive polymer is preferably 50% by mass or more, and may be 80% by mass or more, and 100% of the conductive polymer may be the polyaniline compound.
　導電性高分子の重量平均分子量は、特に限定されないが、例えば１０００～１０００００の範囲にあってもよい。 The weight average molecular weight of the conductive polymer is not particularly limited, but may be in the range of 1000 to 100000, for example.
　導電性高分子は、ドーパントを含んでもよい。π電子共役系高分子にドーパントをドープすることによって、優れた導電性が発現する。ドーパントとしては、硝酸イオン、燐酸イオン、硼酸イオン、ベンゼンスルホン酸イオン、ナフタレンスルホン酸イオン、トルエンスルホン酸イオン、メタンスルホン酸イオン（ＣＦ３ＳＯ３ －）、過塩素酸イオン（ＣｌＯ４ －）、テトラフルオロ硼酸イオン（ＢＦ４ －）、ヘキサフルオロ燐酸イオン（ＰＦ６ －）、フルオロ硫酸イオン（ＦＳＯ３ －）、ビス（フルオロスルホニル）イミドイオン（Ｎ（ＦＳＯ２）２ －）、ビス（トリフルオロメタンスルホニル）イミドイオン（Ｎ（ＣＦ３ＳＯ２）２ －）などが挙げられる。これらは単独で用いてもよく、２種以上を組み合わせて用いてもよい。 The conductive polymer may contain dopants. By doping the π-electron conjugated polymer with a dopant, excellent conductivity is exhibited. Dopants include nitrate ion, phosphate ion, borate ion, benzenesulfonate ion, naphthalenesulfonate ion, toluenesulfonate ion, methanesulfonate ion (CF 3 SO 3 − ), perchlorate ion (ClO 4 − ), Tetrafluoroborate ion (BF 4 − ), hexafluorophosphate ion (PF 6 − ), fluorosulfate ion (FSO 3 − ), bis(fluorosulfonyl)imide ion (N(FSO 2 ) 2 − ), bis(trifluoromethanesulfonyl ) imide ion (N(CF 3 SO 2 ) 2 − ). These may be used alone or in combination of two or more.
　ドーパントは、高分子イオンであってもよい。高分子イオンとしては、ポリビニルスルホン酸、ポリスチレンスルホン酸、ポリアリルスルホン酸、ポリアクリルスルホン酸、ポリメタクリルスルホン酸、ポリ（２－アクリルアミド－２－メチルプロパンスルホン酸）、ポリイソプレンスルホン酸、ポリアクリル酸などのイオンが挙げられる。これらは単独重合体であってもよく、２種以上のモノマーの共重合体であってもよい。これらは単独で用いてもよく、２種以上を組み合わせて用いてもよい。 The dopant may be a polymer ion. Polymer ions include polyvinylsulfonic acid, polystyrenesulfonic acid, polyallylsulfonic acid, polyacrylsulfonic acid, polymethacrylsulfonic acid, poly(2-acrylamido-2-methylpropanesulfonic acid), polyisoprenesulfonic acid, polyacrylic Examples include ions such as acids. These may be homopolymers or copolymers of two or more monomers. These may be used alone or in combination of two or more.
　導電性高分子は、例えば、導電性高分子の原料モノマーを含む反応液中で、電解重合または化学重合を行うことで合成される。化学重合では、原料モノマーを含む反応液に酸化剤を添加すればよい。導電性高分子の原料モノマーとしては、例えば、アニリン、ピロール、チオフェン、フラン、チオフェンビニレン、ピリジン、または、これらの誘導体を用いることができる。原料モノマーは、オリゴマーを含んでもよい。 A conductive polymer is synthesized, for example, by performing electrolytic polymerization or chemical polymerization in a reaction solution containing raw material monomers for the conductive polymer. In chemical polymerization, an oxidizing agent may be added to a reaction solution containing raw material monomers. As raw material monomers for the conductive polymer, for example, aniline, pyrrole, thiophene, furan, thiophene vinylene, pyridine, or derivatives thereof can be used. The raw material monomer may contain an oligomer.
　電解重合または化学重合は、ドーパントを含む反応液を用いて行ってもよい。ただし、電解重合または化学重合を行うときに用いるドーパントは、電気化学デバイスを構成するドーパントと同じである必要はない。例えば、硫酸イオンと原料モノマーとを含む反応液で電解重合を行った後、硫酸イオンを脱ドープしてもよい。これにより電気化学デバイスの充電時に導電性高分子にドープされるアニオン量を増やすことができる。 Electropolymerization or chemical polymerization may be performed using a reaction solution containing a dopant. However, the dopant used for electropolymerization or chemical polymerization need not be the same as the dopant constituting the electrochemical device. For example, after performing electrolytic polymerization with a reaction solution containing sulfate ions and raw material monomers, sulfate ions may be dedoped. This makes it possible to increase the amount of anions doped into the conductive polymer during charging of the electrochemical device.
　正極材料層（または電解液中）に、硫酸イオン（ＳＯ４ ２－）が１０００ｐｐｍ以下の割合で含まれていてもよい。このような場合でも、電解液にノニオン性界面活性剤を含ませることで、フロート特性の低下を抑制することができる。 The positive electrode material layer (or in the electrolyte) may contain sulfate ions (SO 4 2− ) at a rate of 1000 ppm or less. Even in such a case, the deterioration of the float characteristics can be suppressed by including the nonionic surfactant in the electrolytic solution.
　正極材料層は、導電性高分子と結着剤（バインダ）とを含み、導電材（導電助剤）を含んでもよい。結着剤は、導電性高分子の粉末同士を接着し、正極材料層の形成を容易とする。正極材料層は、正極合剤を分散媒と混合して正極ペーストを調製し、正極ペーストを正極芯材に塗布した後、塗膜を乾燥させることによって形成してもよい。正極合剤は、導電性高分子を含み、任意成分として結着剤、導電材などを含む。分散媒には、水、アルコールなどの非水溶媒、およびそれらの混合液を用いてもよい。正極材料層の厚さに特に限定はなく、例えば、１０μｍ～３００μｍの範囲にあってもよい。 The positive electrode material layer contains a conductive polymer and a binder, and may contain a conductive material (conductive aid). The binder binds the conductive polymer powder together to facilitate formation of the positive electrode material layer. The positive electrode material layer may be formed by mixing a positive electrode material mixture with a dispersion medium to prepare a positive electrode paste, coating the positive electrode core material with the positive electrode paste, and then drying the coating film. The positive electrode mixture contains a conductive polymer, and optionally contains a binder, a conductive material, and the like. The dispersion medium may be water, a non-aqueous solvent such as alcohol, or a mixture thereof. The thickness of the positive electrode material layer is not particularly limited, and may range, for example, from 10 μm to 300 μm.
　正極合剤に用いる導電性高分子は、粒子状であってもよい。導電性高分子の粒子の平均粒径は、例えば０．３μｍ以上、３．０μｍ以下であってもよい。これにより導電性高分子の表面積を十分に確保でき、アニオンのドープと脱ドープとがよりスムーズに進行する。また、導電性高分子の表面積が過度に大きくないことで、導電性高分子が劣化しにくくなる。なお、平均粒径とは、体積基準の粒度分布における累積体積５０％のメディアン径（Ｄ５０）をいう。平均粒径は、例えばレーザ回折・散乱法により分析すればよい。 The conductive polymer used for the positive electrode mixture may be particulate. The average particle size of the conductive polymer particles may be, for example, 0.3 μm or more and 3.0 μm or less. As a result, a sufficient surface area of the conductive polymer can be secured, and anion doping and dedoping proceed more smoothly. Moreover, since the surface area of the conductive polymer is not excessively large, the conductive polymer is less likely to deteriorate. The average particle size is the median diameter (D50) of 50% cumulative volume in the volume-based particle size distribution. The average particle size may be analyzed by, for example, a laser diffraction/scattering method.
　導電材としては、例えば、カーボンブラックのような粒子状炭素材料、炭素繊維、カーボンナノチューブ、カーボンナノファイバ等の繊維状炭素材料などが含まれる。カーボンブラックの例には、アセチレンブラック、ケッチェンブラック、ファーネスブラックなどが含まれる。 Examples of conductive materials include particulate carbon materials such as carbon black, fibrous carbon materials such as carbon fibers, carbon nanotubes, and carbon nanofibers. Examples of carbon black include acetylene black, ketjen black, furnace black, and the like.
　結着剤は、上述のポリアルキレンオキシド化合物を含む。ポリアルキレンオキシド化合物以外の他の結着剤を正極材料層に含ませてもよい。他の結着剤としては、フッ素樹脂、アクリル樹脂、ゴム材料、セルロース誘導体などが挙げられる。フッ素樹脂としては、ポリフッ化ビニリデン、ポリテトラフルオロエチレン、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などが挙げられる。アクリル樹脂としては、ポリアクリル酸、アクリル酸－メタクリル酸共重合体などが挙げられる。ゴム材料としては、スチレンブタジエンゴムが挙げられる。セルロース誘導体としてはカルボキシメチルセルロースが挙げられる。 The binder contains the polyalkylene oxide compound described above. A binder other than the polyalkylene oxide compound may be included in the positive electrode material layer. Other binders include fluororesins, acrylic resins, rubber materials, cellulose derivatives, and the like. The fluorine resin includes polyvinylidene fluoride, polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, and the like. Examples of acrylic resins include polyacrylic acid and acrylic acid-methacrylic acid copolymers. Examples of rubber materials include styrene-butadiene rubber. Carboxymethyl cellulose is mentioned as a cellulose derivative.
　正極材料層に占める導電性高分子の含有量は、６０質量％以上の範囲にあってもよい。正極材料層に占める導電材の含有量は１～３０質量％の範囲にあってもよく、５～１５質量％の範囲にあってもよい。正極材料層に占める結着剤の含有量は１～１０質量％の範囲にあってもよい。正極材料層に占めるポリアルキレンオキシド化合物の含有量は１～９質量％もしくは１～５質量％の範囲にあってもよい。 The content of the conductive polymer in the positive electrode material layer may be in the range of 60% by mass or more. The content of the conductive material in the positive electrode material layer may be in the range of 1 to 30% by mass, or may be in the range of 5 to 15% by mass. The content of the binder in the positive electrode material layer may be in the range of 1 to 10% by mass. The content of the polyalkylene oxide compound in the positive electrode material layer may be in the range of 1 to 9 mass % or 1 to 5 mass %.
＜負極＞
（負極芯材）
　負極芯材には、シート状の金属材料が用いられる。シート状の金属材料は、金属箔、金属多孔体、エッチングメタルなどであればよい。金属材料としては、銅、銅合金、ニッケル、ステンレス鋼などを用い得る。負極芯材の厚みは、例えば１０～１００μｍである。 <Negative Electrode>
(Negative electrode core material)
A sheet-like metal material is used for the negative electrode core material. The sheet-shaped metal material may be a metal foil, a metal porous body, an etched metal, or the like. As metal materials, copper, copper alloys, nickel, stainless steel, and the like can be used. The thickness of the negative electrode core material is, for example, 10 to 100 μm.
（負極材料層）
　負極材料層は、負極活物質として、電気化学的にリチウムイオンを吸蔵および放出する材料を備える。このような材料としては、炭素質材料、金属化合物、合金、セラミックス材料などが挙げられる。中でも、炭素質材料は、負極の電位を低くすることができる点で好ましい。炭素質材料としては、黒鉛、ハードカーボン、ソフトカーボンが好ましく、特にハードカーボンが好ましい。中でも、Ｘ線回折パターンから得られる（００２）面のｄ値が０．３８ｎｍ以上であるハードカーボンは、黒鉛に比べて抵抗が低く、容量も高くて好ましい。 (Negative electrode material layer)
The negative electrode material layer includes, as a negative electrode active material, a material that electrochemically absorbs and releases lithium ions. Examples of such materials include carbonaceous materials, metallic compounds, alloys, and ceramic materials. Among them, the carbonaceous material is preferable in that the potential of the negative electrode can be lowered. As the carbonaceous material, graphite, hard carbon and soft carbon are preferred, and hard carbon is particularly preferred. Among them, hard carbon having a d value of 0.38 nm or more on the (002) plane obtained from the X-ray diffraction pattern is preferable because it has a lower resistance and a higher capacity than graphite.
　負極材料層は、例えば、負極合剤を分散媒と混合して負極ペーストを調製し、負極ペーストを負極芯材に塗布した後、塗膜を乾燥させることによって形成してもよい。負極合剤は、負極活物質を含み、任意成分として結着剤、導電材などを含み得る。導電材および結着剤としては、例えば正極用に例示した材料を用い得る。分散媒には、例えば正極ペースト用に例示した材料を用い得る。負極材料層の厚さに特に限定はなく、例えば、１０μｍ～３００μｍの範囲にあってもよい。 The negative electrode material layer may be formed, for example, by mixing a negative electrode mixture with a dispersion medium to prepare a negative electrode paste, applying the negative electrode paste to the negative electrode core material, and then drying the coating film. The negative electrode mixture contains a negative electrode active material, and may optionally contain a binder, a conductive material, and the like. As the conductive material and binder, for example, the materials exemplified for the positive electrode can be used. For the dispersion medium, for example, the materials exemplified for the positive electrode paste can be used. The thickness of the negative electrode material layer is not particularly limited, and may be in the range of 10 μm to 300 μm, for example.
　負極材料層には、予めリチウムイオンをプレドープすることが望ましい。これにより、負極の電位が低下するため、正極と負極の電位差（すなわち電圧）が大きくなり、電気化学デバイスのエネルギー密度が向上する。 It is desirable to pre-dope the negative electrode material layer with lithium ions in advance. This lowers the potential of the negative electrode, increasing the potential difference (that is, voltage) between the positive electrode and the negative electrode, thereby improving the energy density of the electrochemical device.
　リチウムイオンの負極へのプレドープは、例えば、リチウムイオン供給源となる金属リチウム層を負極材料層の表面に形成し、金属リチウム層を有する負極を、リチウムイオン伝導性を有する電解液に含浸させることにより進行する。このとき、金属リチウム層からリチウムイオンが非水電解液中に溶出し、溶出したリチウムイオンが負極活物質に吸蔵される。例えば負極活物質として黒鉛やハードカーボンを用いる場合には、リチウムイオンが黒鉛の層間やハードカーボンの細孔に挿入される。プレドープさせるリチウムイオンの量は、金属リチウム層の質量により制御することができる。プレドープされるリチウム量は、例えば、負極材料層に吸蔵可能な最大量の５０％～９５％程度であってもよい。 Pre-doping of lithium ions to the negative electrode is performed, for example, by forming a metallic lithium layer as a lithium ion supply source on the surface of the negative electrode material layer, and impregnating the negative electrode having the metallic lithium layer with an electrolytic solution having lithium ion conductivity. Proceed by At this time, lithium ions are eluted from the metal lithium layer into the non-aqueous electrolyte, and the eluted lithium ions are occluded by the negative electrode active material. For example, when graphite or hard carbon is used as the negative electrode active material, lithium ions are inserted between the graphite layers or in the pores of the hard carbon. The amount of pre-doped lithium ions can be controlled by the mass of the metallic lithium layer. The amount of lithium to be pre-doped may be, for example, about 50% to 95% of the maximum amount that can be occluded in the negative electrode material layer.
　負極にリチウムイオンをプレドープする工程は、電極体を組み立てる前に行なってもよく、電解液とともに電極体を電気化学デバイスのケースに収容してからプレドープを進行させてもよい。 The step of pre-doping the negative electrode with lithium ions may be performed before assembling the electrode body, or the pre-doping may proceed after housing the electrode body together with the electrolytic solution in the case of the electrochemical device.
＜セパレータ＞
　セパレータとしては、セルロース繊維製の不織布、ガラス繊維製の不織布、ポリオレフィン製の微多孔膜、織布もしくは不織布などを用い得る。セパレータの厚みは、例えば１０～３００μｍであり、１０～４０μｍが好ましい。 <Separator>
As the separator, a cellulose fiber nonwoven fabric, a glass fiber nonwoven fabric, a polyolefin microporous film, a woven fabric or a nonwoven fabric, or the like can be used. The thickness of the separator is, for example, 10-300 μm, preferably 10-40 μm.
＜電解液＞
　電解液は、リチウムイオン伝導性を有する。電解液は、非水溶媒と、リチウム塩と、ノニオン性界面活性剤と含む。リチウム塩は、リチウムイオンとアニオンとの塩であり、リチウム塩に由来するアニオンが電気化学デバイスの充電時に正極にドープされる。 <Electrolyte>
The electrolyte has lithium ion conductivity. The electrolyte contains a non-aqueous solvent, a lithium salt, and a nonionic surfactant. A lithium salt is a salt of a lithium ion and an anion, and the anion derived from the lithium salt is doped into the positive electrode during charging of the electrochemical device.
　リチウム塩としては、例えば、ＬＩＦＳＩ、ＬｉＣｌＯ4、ＬｉＢＦ4、ＬｉＰＦ6、ＬｉＡｌＣｌ4、ＬｉＳｂＦ6、ＬｉＳＣＮ、ＬｉＣＦ3ＳＯ3、ＬｉＦＳＯ3、ＬｉＣＦ3ＣＯ2、ＬｉＡｓＦ6、ＬｉＢ10Ｃｌ10、ＬｉＣｌ、ＬｉＢｒ、ＬｉＩ、ＬｉＢＣｌ4、ＬｉＮ（ＣＦ3ＳＯ2）2などが挙げられる。これらは１種を単独で用いても、２種以上を組み合わせて用いてもよい。中でも、ＬＩＦＳＩ、ＬｉＰＦ６およびＬｉＢＦ４からなる群より選択される少なくとも１種を用いることが望ましい。 Lithium salts include, for example, LIFSI , LiClO4, LiBF4 , LiPF6 , LiAlCl4 , LiSbF6 , LiSCN , LiCF3SO3 , LiFSO3 , LiCF3CO2 , LiAsF6 , LiB10Cl10 , LiCl , LiBr , LiI, LiBCl 4 , LiN(CF 3 SO 2 ) 2 and the like. These may be used individually by 1 type, or may be used in combination of 2 or more type. Among them, it is desirable to use at least one selected from the group consisting of LIFSI, LiPF 6 and LiBF 4 .
　非水溶媒は、特に制限されず、目的に応じて適宜選択することができる。例えば、エチレンカーボネート（ＥＣ）、プロピレンカーボネート（ＰＣ）、ブチレンカーボネートなどの環状カーボネート、ジメチルカーボネート（ＤＭＣ）、ジエチルカーボネート（ＤＥＣ）、エチルメチルカーボネート（ＥＭＣ）などの鎖状カーボネート、ギ酸メチル、酢酸メチル、プロピオン酸メチル(ＰＣ)、プロピオン酸エチルなどの脂肪族カルボン酸エステル、γ－ブチロラクトン、γ－バレロラクトンなどのラクトン類、１，２－ジメトキシエタン（ＤＭＥ）、１，２－ジエトキシエタン（ＤＥＥ）、エトキシメトキシエタン（ＥＭＥ）などの鎖状エーテル、テトラヒドロフラン、２－メチルテトラヒドロフランなどの環状エーテル、ジメチルスルホキシド、１，３－ジオキソラン、ホルムアミド、アセトアミド、ジメチルホルムアミド、ジオキソラン、アセトニトリル、プロピオニトリル、ニトロメタン、エチルモノグライム、トリメトキシメタン、スルホラン、メチルスルホラン、１，３－プロパンサルトンなどを用いることができる。これらは１種単独で使用してもよいし、２種以上を併用してもよい。 The non-aqueous solvent is not particularly limited and can be appropriately selected according to the purpose. For example, ethylene carbonate (EC), propylene carbonate (PC), cyclic carbonates such as butylene carbonate, chain carbonates such as dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), methyl formate, methyl acetate , methyl propionate (PC), ethyl propionate and other aliphatic carboxylic acid esters, γ-butyrolactone, γ-valerolactone and other lactones, 1,2-dimethoxyethane (DME), 1,2-diethoxyethane ( DEE), linear ethers such as ethoxymethoxyethane (EME), cyclic ethers such as tetrahydrofuran and 2-methyltetrahydrofuran, dimethylsulfoxide, 1,3-dioxolane, formamide, acetamide, dimethylformamide, dioxolane, acetonitrile, propionitrile, Nitromethane, ethylmonoglyme, trimethoxymethane, sulfolane, methylsulfolane, 1,3-propanesultone and the like can be used. These may be used individually by 1 type, and may use 2 or more types together.
　必要に応じて電解液に添加剤を含ませてもよい。例えば、負極表面にリチウムイオン伝導性の高い被膜を形成する添加剤として、ビニレンカーボネート、ビニルエチレンカーボネート、ジビニルエチレンカーボネートなどの不飽和カーボネートを用いてもよい。 Additives may be added to the electrolytic solution as necessary. For example, an unsaturated carbonate such as vinylene carbonate, vinylethylene carbonate, or divinylethylene carbonate may be used as an additive that forms a film having high lithium ion conductivity on the surface of the negative electrode.
　上記の実施形態では、円筒形状の巻回型の電気化学デバイスについて例示したが、本発明の適用範囲は上記に限定されず、角形形状の巻回型や積層型の電気化学デバイスにも適用することができる。 In the above embodiments, the cylindrical wound electrochemical device was exemplified, but the scope of application of the present invention is not limited to the above, and it is also applicable to rectangular wound and laminated electrochemical devices. be able to.
　以下、実施例に基づいて、本発明をより詳細に説明するが、本発明は実施例に限定されるものではない。 The present invention will be described in more detail below based on examples, but the present invention is not limited to the examples.
《実施例１～７》
（１）正極の作製
　厚さ３０μｍのアルミニウム箔の両面に、炭化アルミニウム層（厚さ１００ｎｍ、炭素原子の質量割合２５質量％）と、カーボンブラックを含むカーボン層（厚さ２μｍ）とを、順に形成することによって、正極芯材を作製した。 <<Examples 1 to 7>>
(1) Preparation of positive electrode On both sides of a 30 μm thick aluminum foil, an aluminum carbide layer (thickness: 100 nm, mass ratio of carbon atoms: 25% by mass) and a carbon layer containing carbon black (thickness: 2 μm) are sequentially formed. A positive electrode core material was produced by forming.
　正極活物質の導電性高分子と、導電材のカーボンブラックの分散液と、結着剤のスチレンブタジエンゴム（ＳＢＲ）の分散液と、ポリエチレンオキシド（ＰＥＯ）（重量平均分子量６００，０００）の溶液とを混合し、正極ペーストを調製した。正極ペーストにおける導電性高分子、カーボンブラック、スチレンブタジエンゴム（ＳＢＲ）、およびポリエチレンオキシド（ＰＥＯ）の混合比は、それぞれ、表１に示す質量％とした。 A conductive polymer as a positive electrode active material, a dispersion of carbon black as a conductive material, a dispersion of styrene-butadiene rubber (SBR) as a binder, and a solution of polyethylene oxide (PEO) (weight average molecular weight: 600,000). were mixed to prepare a positive electrode paste. The mixing ratios of the conductive polymer, carbon black, styrene-butadiene rubber (SBR), and polyethylene oxide (PEO) in the positive electrode paste were set to mass % shown in Table 1, respectively.
　次に、正極ペーストを正極芯材の両面に塗布し、塗膜をホットプレートで６０～９０℃程度で加熱後、これをロールプレス機で加圧し、更に１１０℃で１２時間真空乾燥することで厚さ３０μｍの正極材料層を両面に有する正極を得た。 Next, the positive electrode paste is applied to both sides of the positive electrode core material, the coating film is heated with a hot plate at about 60 to 90 ° C., pressurized with a roll press, and further vacuum-dried at 110 ° C. for 12 hours. A positive electrode having positive electrode material layers with a thickness of 30 μm on both sides was obtained.
　導電性高分子には、平均粒径（Ｄ５０）が３μｍのポリアニリン粒子を用いた。カーボンブラックの分散液は、カーボンブラックと水とで構成され、カーボンブラック：水＝２０：８０の質量比である。カーボンブラックには、アセチレンブラック（ＡＢ）を用いた。ＳＢＲの分散液は、ＳＢＲと水とで構成され、ＳＢＲ：水＝４０：６０の質量比であった。ＰＥＯ溶液は、ＰＥＯと水とで構成され、ＰＥＯ：水＝３：９７の質量比であった。 Polyaniline particles with an average particle size (D50) of 3 μm were used as the conductive polymer. The carbon black dispersion liquid is composed of carbon black and water, and the mass ratio of carbon black:water is 20:80. Acetylene black (AB) was used as carbon black. The SBR dispersion liquid was composed of SBR and water at a weight ratio of SBR:water=40:60. The PEO solution was composed of PEO and water at a mass ratio of PEO:water=3:97.
（２）負極の作製
　厚さ２０μｍの銅箔を負極芯材として準備した。一方、負極合剤と水とを４０：６０の重量比で含む負極ペーストを調製した。負極合剤は、ハードカーボン９０質量部と、ケッチェンブラック５質量部と、カルボキシセルロース１.５質量部と、スチレンブタジエンゴム３質量部との混合粉末である。次に、負極ペーストを負極芯材の両面に塗布し、塗膜を乾燥して、厚さ３５μｍの負極材料層を両面に有する負極を得た。 (2) Preparation of Negative Electrode A copper foil having a thickness of 20 μm was prepared as a negative electrode core material. On the other hand, a negative electrode paste containing a negative electrode mixture and water at a weight ratio of 40:60 was prepared. The negative electrode mixture is a mixed powder of 90 parts by mass of hard carbon, 5 parts by mass of Ketjenblack, 1.5 parts by mass of carboxycellulose, and 3 parts by mass of styrene-butadiene rubber. Next, the negative electrode paste was applied to both sides of the negative electrode core material, and the coating film was dried to obtain a negative electrode having negative electrode material layers having a thickness of 35 μm on both sides.
　次に、負極材料層に、プレドープ完了後の電解液中での負極電位が金属リチウムに対して０．２Ｖ以下となるように計算された分量の金属リチウム箔を貼り付けた。 Next, to the negative electrode material layer, an amount of metallic lithium foil calculated so that the negative electrode potential in the electrolytic solution after pre-doping was 0.2 V or less relative to metallic lithium was attached.
（３）電極体の作製
　正極と負極にそれぞれリードタブを接続した後、セルロース繊維製の不織布のセパレータ（厚さ３５μｍ）と、正極、負極とを、それぞれ、交互に重ね合わせた積層体を巻回して、電極体を形成した。 (3) Fabrication of Electrode Body After connecting lead tabs to the positive electrode and the negative electrode, respectively, a non-woven fabric separator (thickness: 35 μm) made of cellulose fiber, a positive electrode, and a negative electrode were alternately laminated to form a laminate, which was wound. to form an electrode body.
（４）電解液の調製
　乾燥アルゴン雰囲気下で、エチレンカーボネート（ＥＣ）２０体積％、プロピレンカーボネート(ＰＣ)１０体積％，エチルメチルカーボネート（ＥＭＣ）５０体積％およびジチルカーボネート（ＤＥＣ）２０体積％の混合溶媒に、リチウムビス（フルオロスルホニルイミド）（ＬＩＦＳＩ）を１.２ｍｏｌ／Ｌの濃度で溶解し、さらに添加剤としてビニレンカーボネート（ＶＣ）を２質量％添加して、電解液を調製した。 (4) Preparation of electrolytic solution In a dry argon atmosphere, 20% by volume ethylene carbonate (EC), 10% by volume propylene carbonate (PC), 50% by volume ethyl methyl carbonate (EMC) and 20% by volume dityl carbonate (DEC) were mixed. Lithium bis(fluorosulfonylimide) (LIFSI) was dissolved in the mixed solvent at a concentration of 1.2 mol/L, and 2% by mass of vinylene carbonate (VC) was added as an additive to prepare an electrolytic solution.
（５）電気化学デバイスの作製
　開口を有する有底の容器に、電極体と電解液とを収容し、図１に示すような電気化学デバイスを組み立てた。その後、正極と負極との端子間に３．８Ｖの充電電圧を印加しながら２５℃で２４時間エージングし、リチウムイオンの負極へのプレドープを進行させた。このようにして、実施例のセルＡ１～Ａ７を完成させた。 (5) Fabrication of Electrochemical Device An electrode assembly and an electrolytic solution were placed in a bottomed container having an opening, and an electrochemical device as shown in FIG. 1 was assembled. After that, aging was performed at 25° C. for 24 hours while a charging voltage of 3.8 V was applied between the terminals of the positive electrode and the negative electrode to advance the pre-doping of lithium ions to the negative electrode. Thus, the cells A1 to A7 of the example were completed.
《比較例１》
　正極の作製において、正極活物質の導電性高分子と、導電材のカーボンブラックの分散液と、結着剤のスチレンブタジエンゴム（ＳＢＲ）の分散液と、カルボキシメチルセルロース（ＣＭＣ）溶液とを混合し、正極ペーストを調製した。正極ペーストにおける導電性高分子、カーボンブラック、スチレンブタジエンゴム（ＳＢＲ）、およびカルボキシメチルセルロース（ＣＭＣ）の混合比率は、質量比で７５：１５：７：３とした。ＣＭＣ溶液は、ＣＭＣと水とで構成され、ＣＭＣ：水＝３：９７の質量比であった。 <<Comparative example 1>>
In manufacturing the positive electrode, a conductive polymer as a positive electrode active material, a carbon black dispersion as a conductive material, a styrene-butadiene rubber (SBR) dispersion as a binder, and a carboxymethyl cellulose (CMC) solution are mixed. , positive electrode paste was prepared. The mixing ratio of the conductive polymer, carbon black, styrene-butadiene rubber (SBR), and carboxymethyl cellulose (CMC) in the positive electrode paste was 75:15:7:3 in mass ratio. The CMC solution was composed of CMC and water at a mass ratio of CMC:water=3:97.
　これ以外については、実施例１（セルＡ１）と同様にして、比較例のセルＢ１を完成させた。 Except for this, the cell B1 of the comparative example was completed in the same manner as in Example 1 (cell A1).
《比較例２》
　正極の作製において、正極活物質の導電性高分子と、導電材のカーボンブラックの分散液と、結着剤のスチレンブタジエンゴム（ＳＢＲ）の分散液と、ポリアクリル酸（ＰＡＡ）溶液とを混合し、正極ペーストを調製した。正極ペーストにおける導電性高分子、カーボンブラック、スチレンブタジエンゴム（ＳＢＲ）、およびポリアクリル酸（ＰＡＡ）の混合比率は、質量比で７５：１５：７：３とした。ＰＡＡ溶液は、ＰＡＡと水とで構成され、ＰＡＡ：水＝５：９５の質量比であった。 <<Comparative Example 2>>
In the preparation of the positive electrode, the conductive polymer of the positive electrode active material, the carbon black dispersion of the conductive material, the styrene-butadiene rubber (SBR) dispersion of the binder, and the polyacrylic acid (PAA) solution are mixed. Then, a positive electrode paste was prepared. The mixing ratio of the conductive polymer, carbon black, styrene-butadiene rubber (SBR), and polyacrylic acid (PAA) in the positive electrode paste was 75:15:7:3 by mass. The PAA solution was composed of PAA and water, and the mass ratio of PAA:water was 5:95.
　これ以外については、実施例１（セルＡ１）と同様にして、比較例のセルＢ２を完成させた。 Except for this, the cell B2 of the comparative example was completed in the same manner as in Example 1 (cell A1).
《比較例３》
　正極の作製において、正極活物質の導電性高分子と、導電材のカーボンブラックの分散液と、結着剤のポリアクリル酸（ＰＡＡ）溶液と、カルボキシメチルセルロース（ＣＭＣ）溶液とを混合し、正極ペーストを調製した。正極ペーストにおける導電性高分子、カーボンブラック、ポリアクリル酸（ＰＡＡ）およびカルボキシメチルセルロース（ＣＭＣ）の混合比率は、質量比で７５：１５：７：３とした。ＰＡＡ溶液は、ＰＡＡと水とで構成され、ＰＡＡ：水＝５：９５の質量比であった。ＣＭＣ溶液は、ＣＭＣと水とで構成され、ＣＭＣ：水＝３：９７の質量比であった。 <<Comparative Example 3>>
In the preparation of the positive electrode, a conductive polymer as a positive electrode active material, a carbon black dispersion as a conductive material, a polyacrylic acid (PAA) solution as a binder, and a carboxymethyl cellulose (CMC) solution are mixed to form a positive electrode. A paste was prepared. The mixing ratio of the conductive polymer, carbon black, polyacrylic acid (PAA) and carboxymethyl cellulose (CMC) in the positive electrode paste was 75:15:7:3 in mass ratio. The PAA solution was composed of PAA and water, and the mass ratio of PAA:water was 5:95. The CMC solution was composed of CMC and water at a mass ratio of CMC:water=3:97.
　これ以外については、実施例１（セルＡ１）と同様にして、比較例のセルＢ３を完成させた。 Except for this, the cell B3 of the comparative example was completed in the same manner as in Example 1 (cell A1).
　得られた電気化学デバイス（セルＡ１～Ａ７およびＢ１～Ｂ３）について、以下の方法で評価した。 The obtained electrochemical devices (cells A1 to A7 and B1 to B3) were evaluated by the following method.
（１）低温内部抵抗（ＤＣＲ）
　セルを３．６Ｖの電圧で充電した後、－３０℃で２時間放置後、所定時間放電した際の電圧降下量と放電電流との関係から、低温での内部抵抗（-３０℃ＤＣＲ）を求めた。 (1) Low temperature internal resistance (DCR)
After charging the cell at a voltage of 3.6V, leave it at -30°C for 2 hours, and then discharge it for a predetermined time. asked.
（２）フロート特性
　２５℃の環境下で、セルを３．６Ｖの電圧で充電した後、５．０Ａの電流で２．５Ｖまで放電した。途中３．３Ｖから３．０Ｖに低下する間に流れた放電電荷量を電圧変化ΔＶ（＝０．３Ｖ）で除算し、初期容量Ｃ０（Ｆ）を求めた。 (2) Float characteristics In an environment of 25°C, the cell was charged at a voltage of 3.6V and then discharged at a current of 5.0A to 2.5V. The initial capacity C 0 (F) was obtained by dividing the discharge charge amount that flowed while the voltage dropped from 3.3 V to 3.0 V on the way by the voltage change ΔV (=0.3 V).
　次に、セルを、６０℃、３．６Ｖの条件で１０００時間連続充電した。その後、５．０Ａの電流で２．５Ｖまで放電し、途中３．３Ｖから３．０Ｖに低下する間に流れた放電電荷量を電圧変化ΔＶ（＝０．３Ｖ）で除算し、容量Ｃ１（Ｆ）を求めた。連続充電後の容量の、連続充電前（初期）の容量Ｃ０に対する変化率を、Ｃ１／Ｃ０により算出した。変化率が大きい（１に近い）ほど、フロート特性が優れていることを意味する。 Next, the cell was continuously charged at 60° C. and 3.6 V for 1000 hours. After that, it was discharged to 2.5 V at a current of 5.0 A, and the amount of discharged charge that flowed during the decrease from 3.3 V to 3.0 V was divided by the voltage change ΔV (= 0.3 V), and the capacitance C 1 (F) was obtained. The rate of change of the capacity after continuous charging with respect to the capacity C0 before continuous charging (initial) was calculated by C1 / C0 . A larger rate of change (closer to 1) means better float characteristics.
　低温内部抵抗およびフロート特性の評価結果を表１に示す。表１では、各電気化学デバイス（セルＡ１～Ａ７およびＢ１～Ｂ３）における正極の構成（導電性高分子であるポリアニリン、導電助剤であるアセチレンブラック、および、結着剤の含有割合）が併せて示されている。 Table 1 shows the evaluation results of low-temperature internal resistance and float characteristics. In Table 1, the composition of the positive electrode in each electrochemical device (cells A1 to A7 and B1 to B3) (the content ratio of the conductive polymer polyaniline, the conductive aid acetylene black, and the binder) is also shown. are shown.
　表１において、低温内部抵抗は、比較例１のセルＢ１の内部抵抗を１００とした相対値で示す。また、表１において、フロート特性は、比較例１のセルＢ１の容量の変化率を１００とした相対値で示す。表１において、セルＡ１～Ａ７は実施例であり、セルＢ１～Ｂ３は比較例である。 In Table 1, the low-temperature internal resistance is shown as a relative value with the internal resistance of the cell B1 of Comparative Example 1 set to 100. In Table 1, the float characteristics are shown as relative values, with the rate of change of the capacity of the cell B1 of Comparative Example 1 being 100. In Table 1, cells A1 to A7 are examples, and cells B1 to B3 are comparative examples.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１より、正極材料層に結着剤としてポリアルキレンオキシド化合物を含ませたセルＡ１～Ａ７では、結着剤としてポリアルキレンオキシド化合物を含まないセルＢ１～Ｂ３と比較して、－３０℃での低温内部抵抗およびフロート特性が顕著に改善した。 From Table 1, in the cells A1 to A7 in which the positive electrode material layer contains a polyalkylene oxide compound as a binder, compared with the cells B1 to B3 that do not contain a polyalkylene oxide compound as a binder, The low-temperature internal resistance and float characteristics of the steel were remarkably improved.
　本発明に係る電気化学デバイスは、低温特性とフロート特性に優れるため、各種用途の電源（例えばバックアップ用電源）として好適である。 The electrochemical device according to the present invention is excellent in low-temperature characteristics and float characteristics, so it is suitable as a power source (for example, a backup power source) for various uses.
　１００：電極体
　　１０：正極
　　１１ｘ：正極芯材露出部
　　１３：正極集電板
　　１５：タブリード
　　２０：負極
　　２１ｘ：負極芯材露出部
　　２３：負極集電板
　　３０：セパレータ
　２００：電気化学デバイス
　　２１０：セルケース
　　２２０：封口板
　　２２１：ガスケット 100: Electrode body 10: Positive electrode 11x: Positive electrode core exposed part 13: Positive electrode current collector 15: Tab lead 20: Negative electrode 21x: Negative electrode core exposed part 23: Negative electrode current collector 30: Separator 200: Electrochemical device 210: Cell Case 220: Sealing plate 221: Gasket

Claims (6)

  1. 　正極、負極およびリチウムイオン伝導性の電解質を含み、
    　前記正極は、正極活物質および結着剤を含む正極材料層を有し、
    　前記正極活物質は、少なくともアニオンを可逆的にドープおよび脱ドープ可能な導電性高分子を含み、
    　前記負極は、リチウムイオンを可逆的にドープおよび脱ドープ可能な負極活物質を含み、
    　前記結着剤は、ポリアルキレンオキシドおよびその誘導体からなる群より選択される少なくとも１種のポリアルキレンオキシド化合物を含む、電気化学デバイス。     comprising a positive electrode, a negative electrode and a lithium ion conductive electrolyte;
    The positive electrode has a positive electrode material layer containing a positive electrode active material and a binder,
    The positive electrode active material contains a conductive polymer capable of reversibly doping and dedoping at least anions,
    the negative electrode includes a negative electrode active material capable of reversibly doping and dedoping lithium ions;
    The electrochemical device, wherein the binder comprises at least one polyalkylene oxide compound selected from the group consisting of polyalkylene oxides and derivatives thereof.
  2. 　前記ポリアルキレンオキシド化合物の含有量は、前記正極材料層の質量の全体に対して１質量％以上９質量％以下である、請求項１に記載の電気化学デバイス。 The electrochemical device according to claim 1, wherein the content of said polyalkylene oxide compound is 1% by mass or more and 9% by mass or less with respect to the total mass of said positive electrode material layer.
  3. 　前記ポリアルキレンオキシド化合物は、ポリエチレンオキシドおよびその誘導体からなる群より選択される少なくとも１種を含む、請求項１または２に記載の電気化学デバイス。 The electrochemical device according to claim 1 or 2, wherein the polyalkylene oxide compound includes at least one selected from the group consisting of polyethylene oxide and derivatives thereof.
  4. 　前記導電性高分子が、ポリアニリン化合物を含む、請求項１～３のいずれか１項に記載の電気化学デバイス。 The electrochemical device according to any one of claims 1 to 3, wherein the conductive polymer contains a polyaniline compound.
  5. 　前記正極材料層は、導電助剤をさらに含み、
    　前記導電助剤が、カーボンブラックおよびカーボンナノチューブからなる群より選択される少なくとも１種を含む、請求項１～４のいずれか１項に記載の電気化学デバイス。     The positive electrode material layer further includes a conductive aid,
    The electrochemical device according to any one of claims 1 to 4, wherein said conductive aid contains at least one selected from the group consisting of carbon black and carbon nanotubes.
  6. 　前記リチウム塩は、ヘキサフルオロリン酸リチウム、テトラフルオロホウ酸リチウムおよびリチウムビス（フルオロスルホニル）イミドからなる群より選択される少なくとも１種を含む、請求項１～５のいずれか１項に記載の電気化学デバイス。 The lithium salt according to any one of claims 1 to 5, comprising at least one selected from the group consisting of lithium hexafluorophosphate, lithium tetrafluoroborate and lithium bis(fluorosulfonyl)imide. electrochemical device.
PCT/JP2022/012118 2021-03-22 2022-03-17 Electrochemical device WO2022202578A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2023509086A JPWO2022202578A1 (en) 2021-03-22 2022-03-17

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2021-047624 2021-03-22
JP2021047624 2021-03-22

Publications (1)

Publication Number Publication Date
WO2022202578A1 true WO2022202578A1 (en) 2022-09-29

Family

ID=83397204

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2022/012118 WO2022202578A1 (en) 2021-03-22 2022-03-17 Electrochemical device

Country Status (2)

Country Link
JP (1) JPWO2022202578A1 (en)
WO (1) WO2022202578A1 (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1145738A (en) * 1997-05-30 1999-02-16 Mitsubishi Chem Corp Lithium secondary battery and its manufacture
JP2007019108A (en) * 2005-07-05 2007-01-25 Fuji Heavy Ind Ltd Lithium ion capacitor
JP2017504145A (en) * 2013-11-18 2017-02-02 ビーエーエスエフ コーポレーション Use of lithium bis (fluorosulfonyl) imide (LIFSI) in a non-aqueous electrolyte solution for use with a positive electrode material of 4.2V or higher for a lithium ion battery

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1145738A (en) * 1997-05-30 1999-02-16 Mitsubishi Chem Corp Lithium secondary battery and its manufacture
JP2007019108A (en) * 2005-07-05 2007-01-25 Fuji Heavy Ind Ltd Lithium ion capacitor
JP2017504145A (en) * 2013-11-18 2017-02-02 ビーエーエスエフ コーポレーション Use of lithium bis (fluorosulfonyl) imide (LIFSI) in a non-aqueous electrolyte solution for use with a positive electrode material of 4.2V or higher for a lithium ion battery

Also Published As

Publication number Publication date
JPWO2022202578A1 (en) 2022-09-29

Similar Documents

Publication Publication Date Title
US9048025B2 (en) Electrode for electric storage device, electric storage device and manufacturing method of electrode for electric storage device
EP1174941B1 (en) Non-aqueous electrolyte and electrochemical device comprising the same
JP5228531B2 (en) Electricity storage device
JP7045616B2 (en) Positive electrodes and electrochemical devices for electrochemical devices, and methods for manufacturing them.
CN108604683B (en) Positive electrode active material for electrochemical device, positive electrode for electrochemical device, and method for producing positive electrode active material for electrochemical device
WO2022014351A1 (en) Electrode for electrochemical devices, and electrochemical device
JP7033700B2 (en) Electrochemical device
WO2022202578A1 (en) Electrochemical device
KR20210004992A (en) Positive electrode and power storage device for power storage device
JP7285401B2 (en) Electrochemical device
JP2008166342A (en) Lithium ion capacitor
WO2020158547A1 (en) Electrochemical device
CN115336040A (en) Negative electrode and secondary battery comprising same
JP2002100403A (en) Nonaqueous electrolyte and nonaqueous electrochemical device containing the same
WO2023162813A1 (en) Electrochemical device
JP7213409B2 (en) Electrochemical device
US20230129000A1 (en) Electrochemical device
WO2020262440A1 (en) Electrochemical device
WO2024024956A1 (en) Electrochemical device
US20220230816A1 (en) Electrochemical device
JP7153840B2 (en) Electrochemical device
WO2019188758A1 (en) Electrochemical device and method for producing same
WO2014097618A1 (en) Nonaqueous solvent for electricity storage devices, nonaqueous electrolyte solution, electricity storage device using nonaqueous electrolyte solution, and lithium secondary battery
US20210066717A1 (en) Electrochemical device
JP2023125850A (en) electrochemical device

Legal Events

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

Ref document number: 22775366

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2023509086

Country of ref document: JP

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 22775366

Country of ref document: EP

Kind code of ref document: A1