WO2021225065A1 - Non-aqueous electrolytic solution, semi-solid electrolyte layer, sheet for secondary battery, and secondary battery - Google Patents

Non-aqueous electrolytic solution, semi-solid electrolyte layer, sheet for secondary battery, and secondary battery Download PDF

Info

Publication number
WO2021225065A1
WO2021225065A1 PCT/JP2021/015591 JP2021015591W WO2021225065A1 WO 2021225065 A1 WO2021225065 A1 WO 2021225065A1 JP 2021015591 W JP2021015591 W JP 2021015591W WO 2021225065 A1 WO2021225065 A1 WO 2021225065A1
Authority
WO
WIPO (PCT)
Prior art keywords
secondary battery
semi
solid electrolyte
negative electrode
positive electrode
Prior art date
Application number
PCT/JP2021/015591
Other languages
French (fr)
Japanese (ja)
Inventor
篤 宇根本
祥晃 熊代
栄二 關
和英 上野
薫 獨古
正義 渡邉
Original Assignee
株式会社日立製作所
国立大学法人横浜国立大学
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 株式会社日立製作所, 国立大学法人横浜国立大学 filed Critical 株式会社日立製作所
Priority to CN202180028662.8A priority Critical patent/CN115461907A/en
Publication of WO2021225065A1 publication Critical patent/WO2021225065A1/en

Links

Images

Classifications

    • 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
    • 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
    • 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
    • H01M10/0569—Liquid materials characterised by the solvents
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H01M10/0585—Construction or manufacture of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to a non-aqueous electrolyte solution, a semi-solid electrolyte layer, a secondary battery sheet, and a secondary battery.
  • Patent Document 1 describes a non-aqueous solvent, an electrolyte salt, and an overcharge control agent that causes an oxidation-reduction reaction at a predetermined potential, and has high thermal stability.
  • a heat-stable salt that stably remains in the non-aqueous electrolyte solution, a protective film-forming agent that forms a protective film on the positive and negative electrodes to suppress the decomposition of the overcharge control agent, or a complex that forms a complex with the transition metal.
  • Liquid or gel-like non-aqueous electrolytes containing at least one of the forming agents are disclosed.
  • the electrolytic solution in the lithium ion secondary battery of Patent Document 1 is insufficient to maintain a high discharge capacity retention rate of the secondary battery when the secondary battery is operated at a relatively high temperature, and is still improved. There was room for.
  • the non-aqueous electrolyte solution of the present invention contains an electrolyte salt and an organic solvent, and the organic solvent is at least one main solvent and a low-viscosity organic solvent selected from the group consisting of sulfolanes and derivatives thereof.
  • the concentration of the electrolyte salt with respect to the main solvent is 1.06 mol / L to 3.46 mol / L, and the relative permittivity of the organic solvent is 63 or less.
  • the non-aqueous electrolyte solution of the present invention provides a non-aqueous electrolyte solution capable of maintaining a high discharge capacity retention rate of the secondary battery when the secondary battery is operated at a relatively high temperature. Issues, configurations and effects other than those described above will be clarified by the following description of the embodiments.
  • a lithium ion secondary battery is an electrochemical device that stores or makes available electrical energy by storing and releasing lithium ions into electrodes in an electrolyte.
  • Lithium-ion secondary batteries are also called by other names such as lithium-ion batteries, non-aqueous electrolyte secondary batteries, and non-aqueous electrolyte secondary batteries, and any of these batteries is the subject of the present invention.
  • the technical idea of the present invention can also be applied to a sodium ion secondary battery, a magnesium ion secondary battery, a calcium ion secondary battery, a zinc secondary battery, an aluminum ion secondary battery and the like.
  • the material may be selected alone or in combination within a range not inconsistent with the contents disclosed in the present specification.
  • materials other than the material group illustrated below may be selected as long as they do not contradict the contents disclosed in the present specification.
  • FIG. 1 is a cross-sectional view of a lithium ion secondary battery according to an embodiment of the present invention.
  • FIG. 1 shows a laminated lithium ion secondary battery, in which the lithium ion secondary battery 1000 has a positive electrode 100, a negative electrode 200, an exterior body 500, and an insulating layer 300.
  • the exterior body 500 houses the insulating layer 300, the positive electrode 100, and the negative electrode 200.
  • the exterior body 500 is selected from a group of materials having corrosion resistance to a non-aqueous electrolytic solution such as aluminum, stainless steel, and nickel-plated steel.
  • the lithium ion secondary battery may also have a winding type configuration.
  • an electrode body 400 composed of a positive electrode 100, an insulating layer 300, and a negative electrode 200 is laminated to form an electrode group.
  • the positive electrode 100 or the negative electrode 200 may be referred to as an electrode.
  • a sheet in which the positive electrode 100 and / or the negative electrode 200 and the insulating layer 300 are laminated may be referred to as a secondary battery sheet.
  • the electrode group can be produced only by laminating the secondary battery sheets.
  • the positive electrode 100 has a positive electrode current collector 120 and a positive electrode mixture layer 110. Positive electrode mixture layers 110 are formed on both sides of the positive electrode current collector 120.
  • the negative electrode 200 has a negative electrode current collector 220 and a negative electrode mixture layer 210. Negative electrode mixture layers 210 are formed on both sides of the negative electrode current collector 220.
  • the positive electrode mixture layer 110 or the negative electrode mixture layer 210 may be referred to as an electrode mixture layer, and the positive electrode current collector 120 or the negative electrode current collector 220 may be referred to as an electrode current collector.
  • the positive electrode current collector 120 has a positive electrode tab 130.
  • the negative electrode current collector 220 has a negative electrode tab 230.
  • the positive electrode tab 130 or the negative electrode tab 230 may be referred to as an electrode tab.
  • No electrode mixture layer is formed on the electrode tab.
  • the electrode mixture layer may be formed on the electrode tab as long as the performance of the lithium ion secondary battery 1000 is not adversely affected.
  • the positive electrode tab 130 and the negative electrode tab 230 project to the outside of the exterior body 500, and the plurality of protruding positive electrode tabs 130 and the plurality of negative electrode tabs 230 are bonded to each other by, for example, ultrasonic bonding, thereby forming lithium ions.
  • a parallel connection is formed within the secondary battery 1000.
  • the lithium ion secondary battery according to the present invention may also have a bipolar configuration having an electrical series connection inside the secondary battery.
  • the positive electrode mixture layer 110 contains a positive electrode active material, a positive electrode conductive agent, and a positive electrode binder.
  • the negative electrode mixture layer 210 contains a negative electrode active material, a negative electrode conductive agent, and a negative electrode binder.
  • the positive electrode active material or the negative electrode active material may be referred to as an electrode active material
  • the positive electrode conductive agent or the negative electrode conductive agent may be referred to as an electrode conductive agent
  • the positive electrode binder or the negative electrode binder may be referred to as an electrode binder.
  • the electrode conductive agent improves the conductivity of the electrode mixture layer.
  • the electrode conductive agent it can be appropriately selected and used from a material group such as Ketjen black, acetylene black, and graphite.
  • the electrode binder binds the electrode active material, the electrode conductive agent, and the like in the electrode.
  • Lithium ions are desorbed from the positive electrode active material showing a noble potential in the charging process, and lithium ions desorbed from the negative electrode active material are inserted in the discharging process.
  • a lithium composite oxide having a transition metal is desirable.
  • LiMO 2 Li excess composition Li [LiM] O 2 , LiM 2 O 4 , LiMPO 4 , LiMVO 4 , LiMBO 3 , Li 2 MSiO 4 (where M is Co, Ni, Mn, Fe). , Cr, Zn, Ta, Al, Mg, Cu, Cd, Mo, Nb, W, Ru and the like).
  • the positive electrode active material includes chalcogenides such as TiS 2 , MoS 2 , Mo 6 S 8 and TiSe 2 , vanadium oxides such as V 2 O 5 , halides such as FeF 3 , and Fe (MoO 4) constituting polyanions.
  • chalcogenides such as TiS 2 , MoS 2 , Mo 6 S 8 and TiSe 2
  • vanadium oxides such as V 2 O 5
  • halides such as FeF 3 , and Fe (MoO 4) constituting polyanions.
  • Fe 2 (SO 4 ) 3 can contain at least one selected from the material group such as quinone-based organic crystals and oxygen.
  • the positive electrode current collector 120 includes an aluminum foil having a thickness of 1 ⁇ m to 100 ⁇ m, an aluminum perforated foil having a thickness of 10 ⁇ m to 100 ⁇ m and a hole diameter of 0.1 mm to 10 mm, an expanded metal, a foamed metal plate, and stainless steel. It can be appropriately selected and used from a material group such as a material such as titanium.
  • ⁇ Negative electrode active material> In the negative electrode active material showing a low potential, lithium ions are desorbed in the discharge process, and lithium ions desorbed from the positive electrode active material in the positive electrode mixture layer 110 are inserted in the charging process.
  • the negative electrode active material include carbon-based materials (graphite, easily graphitized carbon material, amorphous carbon material, organic crystals, activated carbon, etc.), conductive polymer materials (polyacene, polyparaphenylene, polyaniline, polyacetylene, etc.), and lithium.
  • Composite oxides lithium titanate: Li 4 Ti 5 O 12 , Li 2 TiO 4, etc.
  • metallic lithium metals alloying with lithium (having at least one type of aluminum, silicon, tin, etc.) and oxides thereof. It can be appropriately selected and used from the material group such as.
  • the negative electrode current collector 220 includes a copper foil having a thickness of 1 ⁇ m to 100 ⁇ m, a copper perforated foil having a thickness of 1 ⁇ m to 100 ⁇ m and a pore diameter of 0.1 mm to 10 mm, an expanded metal, a foamed metal plate, stainless steel, titanium, nickel, etc. It can be appropriately selected and used from the material group of.
  • An electrode mixture layer is prepared by adhering an electrode slurry, which is a mixture of an electrode active material, an electrode conductive agent, an electrode binder, and a solvent, to an electrode current collector by a coating method such as a doctor blade method, a dipping method, or a spray method.
  • the solvent is selected from a group of materials such as N-methylpyrrolidone (NMP) and water. Then, the electrode mixture layer is dried to remove the solvent, and the electrode mixture layer is pressure-molded by a roll press to produce an electrode.
  • the content of the non-aqueous electrolyte solution in the electrode mixture layer is preferably 20% by volume to 40% by volume.
  • the content of the non-aqueous electrolyte solution is small, the ionic conduction path inside the electrode mixture layer may not be sufficiently formed and the rate characteristics may deteriorate.
  • the content of the non-aqueous electrolyte solution is high, the non-aqueous electrolyte solution may leak from the electrode mixture layer, and the relative amount of the electrode active material becomes insufficient to increase the energy density. May lead to a decline.
  • the non-aqueous electrolytic solution is injected into the lithium ion secondary battery 1000 through an open side of the exterior body 500 or a liquid injection hole, and the electrode mixture layer is thinned. This can be done by filling the pores with a non-aqueous electrolytic solution.
  • a slurry in which a non-aqueous electrolyte solution, an electrode active material, an electrode conductive agent, and an electrode binder are mixed is prepared, and the prepared slurry is applied together on the electrode current collector to be applied to the pores of the electrode mixture layer. It may be filled with a water electrolyte.
  • the supporting particles such as those contained in the semi-solid electrolyte are not required, and the particles such as the electrode active material and the electrode conductive agent in the electrode mixture layer function as the supporting particles, and these particles make the non-aqueous electrolyte solution. Can be retained.
  • the thickness of the electrode mixture layer is equal to or greater than the average particle size of the electrode active material. If the thickness of the electrode mixture layer is small, the electron conductivity between adjacent electrode active materials may deteriorate. If the electrode active material powder contains coarse particles having an average particle size equal to or larger than the thickness of the electrode mixture layer, the coarse particles are removed in advance by sieving classification, wind flow classification, etc., and particles having a thickness equal to or less than the thickness of the electrode mixture layer. Is desirable.
  • the insulating layer 300 serves as a medium for transmitting ions between the positive electrode 100 and the negative electrode 200.
  • the insulating layer 300 also acts as an electron insulator to prevent a short circuit between the positive electrode 100 and the negative electrode 200.
  • the insulating layer 300 can have a semi-solid electrolyte layer.
  • a separator and a semi-solid electrolyte layer may be used in combination.
  • Porous sheets can be used as the separator.
  • Porous sheets include cellulose, modified cellulose (carboxymethyl cellulose (CMC), hydroxypropyl cellulose (HPC), etc.), polyolefin (polypropylene (PP), propylene copolymer, etc.), polyester (polybutylene terephthalate (PET), etc.).
  • Polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), etc.), polyacrylonitrile (PAN), polyaramid, polyamideimide, resins such as polyimide, and materials such as glass can be selected.
  • a separator may be formed by applying a separator forming mixture having separator particles, a separator binder and a solvent to the electrode mixture layer.
  • the separator-forming mixture may be applied to the porous sheet.
  • Separator particles are selected from a group of materials such as ⁇ -alumina (Al 2 O 3 ), silica (SiO 2 ), and zirconia (ZrO 2).
  • the average particle size of the separator particles is preferably 1/100 to 1/2 of the thickness of the separator.
  • the separator binder is appropriately selected from materials such as polyethylene (PE), PP, polytetrafluoroethylene (PTFE), PVDF, P (VdF-HFP), styrene butadiene rubber (SBR), polyargic acid, and polyacrylic acid. Can be used.
  • the separator is filled with the non-aqueous electrolytic solution by injecting the non-aqueous electrolytic solution into the lithium ion secondary battery 1000 from the open side of the exterior body 500 or the liquid injection hole. Can be done.
  • the semi-solid electrolyte layer has a semi-solid electrolyte binder and a semi-solid electrolyte.
  • the semi-solid electrolyte has supported particles and a non-aqueous electrolyte solution.
  • the semi-solid electrolyte has pores formed by aggregates of supported particles, in which the non-aqueous electrolyte solution is held. By retaining the non-aqueous electrolyte solution in the semi-solid electrolyte, the semi-solid electrolyte allows lithium ions to permeate.
  • the semi-solid electrolyte layer can be treated like a solid while containing a liquid component such as a non-aqueous electrolyte solution, and can be a translucent self-supporting membrane. Locally, a liquid component such as a non-aqueous electrolyte solution is responsible for lithium ion conduction, so that it exhibits high ion conductivity. That is, the semi-solid electrolyte layer has the advantages of both the high safety of the solid and the high ionic conduction characteristics of the liquid.
  • a method for producing the semi-solid electrolyte layer there are a method of compression molding the semi-solid electrolyte powder into pellets with a molding die or the like, and a method of adding and mixing the semi-solid electrolyte binder to the semi-solid electrolyte powder to form a sheet. be.
  • a highly flexible sheet-shaped semi-solid electrolyte layer can be produced.
  • a solution of a binder in which a semi-solid electrolyte binder is dissolved in a dispersion solvent is added to and mixed with the semi-solid electrolyte, the mixture is applied on a substrate such as an electrode, and the dispersion solvent is distilled off by drying.
  • a semi-solid electrolyte layer may be prepared.
  • the supported particles are preferably insulating particles and insoluble in a non-aqueous electrolytic solution.
  • the supporting particles can be appropriately selected from a group of materials such as SiO 2 particles, Al 2 O 3 particles, Celia (CeO 2 ) particles, oxide inorganic particles such as ZrO 2 particles, and a solid electrolyte.
  • the oxide-inorganic particles as the supporting particles, the non-aqueous electrolyte solution can be held at a high concentration in the semi-solid electrolyte layer.
  • gas is not generated from the oxide inorganic particles, a semi-solid electrolyte layer can be produced by a roll-to-roll process in the atmosphere.
  • the solid electrolyte can be appropriately selected and used from a material group such as an oxide-based solid electrolyte such as Li-La-Zr-O and a sulfide-based solid electrolyte such as Li 10 Ge 2 PS 12.
  • the average particle size of the primary particles of the supported particles is preferably 1 nm to 10 ⁇ m. If the average particle size of the primary particles of the supporting particles is large, the supporting particles may not be able to properly hold a sufficient amount of the non-aqueous electrolyte solution, and it may be difficult to form a semi-solid electrolyte. Further, if the average particle size of the primary particles of the supported particles is small, the intersurface force between the supported particles becomes large and the supported particles tend to aggregate with each other, which may make it difficult to form a semi-solid electrolyte.
  • the average particle size of the primary particles of the supported particles is more preferably in the range of 1 nm to 50 nm, further preferably in the range of 1 nm to 10 nm.
  • the average particle size of the primary particles of the supported particles can be measured using a TEM.
  • the non-aqueous electrolyte solution contains a main solvent, a low-viscosity organic solvent having a relative permittivity different from that of the main solvent, an electrolyte salt, and an optional negative electrode interface stabilizer.
  • the main solvent has a high relative permittivity and has the effect of increasing the concentration of lithium ions by dissociating the lithium salt.
  • the main solvent is at least one selected from the group consisting of sulfolanes and derivatives thereof (also referred to as "sulfolanes and / or derivatives thereof").
  • the main solvent may contain two or more kinds, for example, two kinds, three kinds, or four kinds of solvents selected from the group consisting of sulfolane and its derivatives.
  • sulfolane and / or its derivative may be referred to as a main solvent.
  • the components contained in the non-aqueous electrolytic solution can be measured by NMR or the like.
  • the relative permittivity of the main solvent and the low-viscosity organic solvent can be measured by a relative permittivity measuring device.
  • the content of the non-aqueous electrolyte solution in the semi-solid electrolyte layer is not particularly limited, but is preferably 40% by volume to 90% by volume. If the content of the non-aqueous electrolyte solution is small, the interfacial resistance between the electrode and the semi-solid electrolyte layer may increase. Further, when the content of the non-aqueous electrolyte solution is large, the non-aqueous electrolyte solution may leak from the semi-solid electrolyte layer.
  • the content of the non-aqueous electrolyte solution in the semi-solid electrolyte layer is preferably 50% by volume to 80% by volume, more preferably 60% by volume to 80% by volume.
  • the content of the non-aqueous electrolyte solution in the semi-solid electrolyte layer is It is preferably 40% by volume to 60% by volume.
  • the weight ratio of the main solvent in the non-aqueous electrolyte solution is not particularly limited, but from the viewpoint of stability of the lithium ion secondary battery and in order to enable high-speed charging / discharging, the weight ratio of the main solvent in the non-aqueous electrolyte solution is not particularly limited. Is preferably 30% by weight (wt%) to 70% by weight, particularly 40% by weight to 60% by weight, and more preferably 45% by weight to 55% by weight.
  • the solvated ionic liquid has a sulfolane and / or a derivative thereof and an electrolyte salt.
  • a solvated ionic liquid containing sulfolane and / or a derivative thereof is used, the transport rate of lithium ions in the semi-solid electrolyte layer is high because the sulfolane and / or its derivative and lithium ions have a unique coordination structure. Become.
  • the solvent-based ionic liquid having an ether solvent and an electrolyte salt in which the input / output characteristics of the secondary battery decrease as the viscosity increases can be used. It is possible to suppress deterioration of the input / output characteristics of the secondary battery.
  • the sulfolane derivative examples include those in which the hydrogen atom bonded to the carbon atom constituting the sulfolane ring is replaced with a fluorine atom, an alkyl group or the like. As a specific example, it can be appropriately selected and used from a material group such as fluorosulfolane, difluorosulfolane, and methylsulfolane.
  • LiBF 4 lithium tetrafluoroborate
  • LiTFSI lithium bis (trifluoromethanesulfonyl) imide
  • LiFSI lithium bis (fluorosulfonyl) imide
  • LiClO 4 lithium bis (fluorosulfonyl) amide
  • LiTFSA Lithium bis (trifluoromethanesulfonyl) amide
  • LiTFSA Lithium bis (trifluoromethanesulfonyl) amide
  • LiBF 4 is stable with respect to a negative electrode active material such as graphite, and can increase the capacity of a secondary battery
  • the solvated ionic liquid having a sulfolane and / or a derivative thereof and an electrolyte salt can be integrally described as an apparent composition.
  • the concentration of the electrolyte salt with respect to the main solvent is preferably 1.06 mol / L to 3.46 mol / L. If the concentration is too high, the viscosity tends to increase, the resistance increases, and the capacity tends to decrease. If the concentration is too low, the solvent tends to be unstable and the life characteristics tend to deteriorate.
  • the low-viscosity organic solvent is an organic solvent having a relative permittivity different from that of the main solvent and having a lower viscosity than the solvated ionic liquid. Therefore, by mixing the low-viscosity organic solvent and the solvated ionic liquid, the viscosity of the solvated ionic liquid can be lowered and the ionic conductivity can be improved. When the internal resistance of the non-aqueous electrolytic solution is large, the internal resistance of the non-aqueous electrolytic solution can be reduced by adding a low-viscosity organic solvent to increase the ionic conductivity of the non-aqueous electrolytic solution.
  • low-viscosity solvent examples include cyclic carbonate esters such as ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate (BC), and fluoroethylene carbonate (FEC), methyl ethyl carbonate (EMC), and carbonic acid.
  • cyclic carbonate esters such as ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate (BC), and fluoroethylene carbonate (FEC), methyl ethyl carbonate (EMC), and carbonic acid.
  • Acyclic esters such as dimethyl (DMC) and diethyl carbonate (DEC), trimethyl phosphate (TMP), triethyl phosphate (TEP), tris phosphite (2,2,2-trifluoroethyl) (TFP), methylphosphon
  • DMC dimethyl
  • DEC diethyl carbonate
  • TMP trimethyl phosphate
  • TEP triethyl phosphate
  • TBP tris phosphite (2,2,2-trifluoroethyl)
  • methylphosphon It can be appropriately selected and used from a material group such as a phosphate ester such as dimethyl acid (DMMP), a lactone such as ⁇ -butyrolactone (GBL), and a mixture of two or more thereof.
  • DMMP dimethyl acid
  • GBL ⁇ -butyrolactone
  • the relative dielectric constant Z of the mixed solvent (main solvent + low-viscosity organic solvent) is the relative dielectric of the i-th main solvent.
  • n is the number of types of the main solvent contained in the mixed solvent
  • m is the number of types of the low-viscosity organic solvent contained in the mixed solvent.
  • the relative dielectric constant Z of the mixed solvent (main solvent + low-viscosity organic solvent) is the relative dielectric constant of the main solvent.
  • the molar ratio of the main solvent in the mixed solvent is q
  • the specific dielectric constant of the low-viscosity organic solvent is p'
  • the molar ratio of the low-viscosity organic solvent in the mixed solvent is q'
  • Z p ⁇ q + p' ⁇ q' ⁇ ⁇ ⁇ Equation (2) It can be represented by, and Z is preferably 63 or less.
  • the viscosity of the solvated ionic liquid can be reduced.
  • a low-viscosity organic solvent is added too much to the solvated ionic liquid, the degree of dissociation of the lithium salt is lowered and high-quality SEI (Solid Electrolyte Interphase) cannot be formed, and the temperature is high (45 ° C.). Life characteristics are reduced.
  • the method for measuring the molar ratio of the main solvent in the mixed solvent and the molar ratio of the low-viscosity organic solvent in the mixed solvent can be measured by NMR.
  • the negative electrode interface stabilizer can be appropriately selected from a group of materials such as vinylene carbonate (VC) and fluoroethylene carbonate (FEC).
  • the non-aqueous electrolyte solution may contain a corrosion inhibitor, if necessary.
  • the corrosion inhibitor forms a film in which the metal does not easily elute even when the positive electrode current collector 120 is exposed to a high electrochemical potential.
  • a material containing an anionic species such as PF 6 or BF 4 and containing a cation species having a strong chemical bond for forming a stable compound in a water-containing atmosphere is desirable.
  • the solubility in water and the presence or absence of hydrolysis can be mentioned.
  • the corrosion inhibitor is a solid, it is desirable that the solubility in water is less than 1%.
  • the presence or absence of hydrolysis can be evaluated by molecular structure analysis of the sample after mixing with water.
  • “not hydrolyzed” means that after the corrosion inhibitor absorbs moisture or mixes with water, it is heated at 100 ° C. or higher to remove water, and 95% of the residue has the same molecular structure as the original corrosion inhibitor. Means showing.
  • M-R Corrosion inhibitor, (M-R) + An - denoted. (M-R) + An - cation is (M-R) +.
  • M is selected from nitrogen (N), boron (B), phosphorus (P) or sulfur (S).
  • R is composed of a hydrocarbon group.
  • An - of the anion An - is.
  • An - The, BF 4 - or PF 6 - it is preferably used.
  • the anions of corrosion inhibitor BF 4 - or PF 6 - is to be in, it can be efficiently suppressed the elution of the positive electrode current collector 120.
  • This, BF 4 - or PF 6 - F anions react with SUS and aluminum electrode current collector is believed to be due to the effect of forming a passive film.
  • Corrosion inhibitors are quaternary ammonium salts such as tetrabutylammonium hexafluorophosphate (TBAPF 6 ) and tetrabutylammonium tetrafluorobolate (TBABF 4 ), 1-ethyl-3-methylimidazolium tetrafluorobolate (EMI-BF 4). ), 1-Ethyl-3-methylimidazolium hexafluorophosphate (EMI-PF 6 ), 1-butyl-3-methylimidazolium tetrafluorobolate (BMI-BF 4 ), 1-butyl-3-methylimidazolium hexa.
  • TAPF 6 tetrabutylammonium hexafluorophosphate
  • TABF 4 tetrabutylammonium tetrafluorobolate
  • EMI-BF 4 1-ethyl-3-methylimidazolium tetrafluorobolate
  • a material group such as an imidazolium salt such as fluorophosphate (BMI-PF 6).
  • BMI-PF 6 fluorophosphate
  • the anion is PF 6 ⁇
  • the elution of the positive electrode current collector 120 can be suitably suppressed.
  • the content of the corrosion inhibitor is preferably 0.5% by weight to 20% by weight, more preferably 1% by weight to 10% by weight, based on the total weight of the non-aqueous electrolyte solution. If the content of the corrosion inhibitor is small, the effect of suppressing the elution of the electrode current collector is reduced, and the battery capacity may be reduced with charging and discharging. In addition, if the content of the corrosion inhibitor is high, the lithium ion conductivity is lowered, and a large amount of stored energy is consumed to decompose the corrosion inhibitor, which may result in a decrease in battery capacity. be.
  • a fluorine-based resin is preferably used as the semi-solid electrolyte binder.
  • the fluorine-based resin can be appropriately selected and used from a material group such as PTFE, PVDF, and P (VdF-HFP).
  • PVDF or P (VdF-HFP) the adhesion between the insulating layer 300 and the electrode current collector is improved, so that the battery performance is improved.
  • a semi-solid electrolyte is formed by supporting or holding the non-aqueous electrolyte solution on the supporting particles.
  • a method for producing a semi-solid electrolyte a non-aqueous electrolyte solution and a supporting particle are mixed in a specific volume ratio, an organic solvent such as methanol is added and mixed to prepare a semi-solid electrolyte slurry, and then the slurry is prepared. Examples thereof include a method of spreading it on a tent or the like and distilling off an organic solvent to obtain a powder of a semi-solid electrolyte.
  • Lithium bis (trifluoromethanesulfonyl) amide which is a lithium salt (Li salt)
  • LiTFSA Lithium bis (trifluoromethanesulfonyl) amide
  • SL sulfolane
  • PC propylene carbonate
  • a graphite film is formed as a negative electrode interface stabilizer.
  • SL main solvent
  • PC low-viscosity solvent
  • Graphite as the negative electrode active material and styrene-butadiene rubber and carboxylmethyl cellulose as the negative electrode binder were weighed so that the weight ratio of the solid content was 98: 1: 1, and these were uniformly mixed by a kneader.
  • the obtained mixture was slurried by adding water to adjust the solid content concentration.
  • the slurry whose concentration was adjusted was applied to both sides of the copper foil, which is the negative electrode current collecting foil, with a tabletop coater, and passed through a drying furnace at 100 ° C. to obtain a negative electrode.
  • the amount of the negative electrode mixture (negative electrode active material + negative electrode binder) applied was 18.1 mg / cm 2 in total on both sides.
  • the electrode density of the obtained negative electrode was adjusted to 1.55 g / cm 3 by a roll press.
  • the separator was formed by applying a non-volatile electrolyte to the surface of the electrode mixture layer.
  • SiO 2 having an average particle size of 1 ⁇ m as the supporting particles and vinylidene fluoride-hexafluoropropylene copolymer (P (VdF-HFP)) as the binder have a weight ratio of 89.3: 10.7.
  • P (VdF-HFP) vinylidene fluoride-hexafluoropropylene copolymer
  • Each was weighed so as to be, and these were uniformly mixed in a kneader.
  • the obtained mixture was slurried by adding NMP to adjust the solid content concentration.
  • the slurry having the adjusted concentration was applied to both the positive electrode and the negative electrode with a tabletop coater and passed through a drying oven at 100 ° C. to obtain a positive electrode and a negative electrode having a non-volatile electrolyte layer formed therein.
  • a positive electrode covered with a microporous film and a punched negative electrode were laminated in the order of negative electrode / positive electrode / negative electrode, and then a 50 ⁇ m-thick PTFE sheet was placed on the negative electrode.
  • Each tab portion provided on the positive electrode and the negative electrode, an aluminum positive electrode terminal, and a nickel negative electrode terminal were welded by ultrasonic welding, respectively.
  • the obtained electrode body is sandwiched between laminate films, one side for liquid injection is left, and three sides including the side on which the tab portion is formed are heat-sealed at 200 ° C. by a laminate sealing device for 20 hours at 50 ° C. It was vacuum dried. Next, after injecting a non-aqueous electrolytic solution from one side for liquid injection, one side for liquid injection was vacuum-sealed to obtain a secondary battery.
  • Examples 2 to 12 Comparative Examples 1 to 2> A secondary battery was produced in the same manner as in Example 1 except that the composition of the non-aqueous electrolyte solution was changed as shown in Table 1, and the components contained in the non-aqueous electrolyte solution were quantified and the discharge capacity was measured.
  • Table 1 shows the composition of the secondary batteries of Examples 1 to 12 and Comparative Examples 1 and 2 and the 45 ° C. discharge capacity retention rate.
  • FIG. 2 shows the relationship between the lithium salt concentration (mol / L) with respect to the main solvent in Examples and Comparative Examples and the discharge capacity retention rate (%) at 45 ° C.
  • FIG. 3 shows the relationship between the mixed solvents in Examples and Comparative Examples. The relationship between the relative permittivity and the discharge capacity retention rate (%) at 45 ° C. is shown.
  • the 45 ° C. discharge capacity retention rate of the secondary battery was plotted against the lithium salt concentration. As shown in FIG. 2, when the lithium salt concentration is smaller than 2.21 mol / L, the 45 ° C. discharge capacity retention rate becomes small, and when the lithium salt concentration is 2.21 mol / L or more, the 45 ° C. discharge capacity is reduced. The maintenance rate has increased. This result is considered to be due to the fact that by mixing a low-viscosity organic solvent with low viscosity and a solvated ionic liquid, the viscosity of the non-aqueous electrolyte solution decreased and the ionic conductivity of the non-aqueous electrolyte solution increased. ..
  • the 45 ° C. discharge capacity retention rate Y of the secondary battery is represented by the following formula (4) according to the lithium salt concentration X in the range of the lithium salt concentration of 0.8 mol / L to 3.8 mol / L. It was confirmed that it would be done.
  • Y -4.0167X 2 + 18.13X + 73.574 ... Equation (4)
  • the range of the lithium salt concentration X at which the 45 ° C. discharge capacity retention rate is larger than the 45 ° C. discharge capacity retention rate (87.7%) of Comparative Example 1 is , 1.06 mol / L to 3.46 mol / L.
  • the range of the lithium salt concentration X at which the 45 ° C. discharge capacity retention rate of the secondary battery was 89.5% or more was 1.25 mol / L to 3.26 mol / L.
  • the range of the lithium salt concentration X at which the 45 ° C. discharge capacity retention rate of the secondary battery is 90% or more was 1.32 mol / L to 3.18 mol / L.
  • the range of the lithium salt concentration X at which the 45 ° C. discharge capacity retention rate of the secondary battery is 92% or more was 1.64 mol / L to 2.86 mol / L. Therefore, the range of the lithium salt concentration X is 1.06 mol / L to 3.46 mol / L, preferably 1.25 mol / L to 3.26 mol / L, and more preferably 1.32 mol / L to 3.18 mol / L. Is.
  • the 45 ° C. discharge capacity retention rate of the secondary battery was plotted against the relative permittivity of the mixed solvent in the non-aqueous electrolyte solution.
  • the relative permittivity of the mixed solvent in the non-aqueous electrolyte solution As shown in FIG. 3, in a composition having a relative permittivity smaller than about 31.5, the larger the relative permittivity, the larger the 45 ° C. discharge capacity retention rate.
  • the relative permittivity larger the 45 ° C. discharge capacity retention rate.
  • the relative permittivity of the main solvent is A
  • the molar ratio of the main solvent in the mixed solvent is M
  • the relative permittivity of the low-viscosity organic solvent is B
  • the molar ratio of the low-viscosity organic solvent in the mixed solvent is
  • the range of the relative permittivity T of the mixed solvent in which the 45 ° C. discharge capacity retention rate is larger than the 45 ° C. discharge capacity retention rate (87.7%) of the secondary battery of Comparative Example 1 is It was 63 or less.
  • the range of the relative permittivity T of the mixed solvent in which the 45 ° C. discharge capacity retention rate Z of the secondary battery was 89.5% or more was 3.9 to 59.
  • the range of the relative permittivity T of the mixed solvent at which the 45 ° C. discharge capacity retention rate of the secondary battery is 90% or more was 5.5 to 58.
  • the range of the relative permittivity T of the mixed solvent at which the 45 ° C. discharge capacity retention rate of the secondary battery is 92% or more was 12.5 to 51.0. Therefore, the range of the relative permittivity T of the mixed solvent is 63 or less, preferably 3.9 to 59, and more preferably 5.5 to 58.
  • Electrode body 500 Exterior body 1000 Lithium ion secondary battery Cited herein. All published publications, patents and patent applications are incorporated herein by reference in their entirety.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Inorganic Chemistry (AREA)
  • Secondary Cells (AREA)

Abstract

The purpose of the present invention is to provide a non-aqueous electrolytic solution with which the discharge capacity retention of a secondary battery operated at a relatively high temperature can be maintained at a high level.　The non-aqueous electrolytic solution contains an electrolyte salt and an organic solvent, wherein the organic solvent includes a main solvent, which is at least one selected from the group consisting of sulfolane and derivatives thereof, and a low viscosity organic solvent, the concentration of the electrolyte salt in the main solvent is 1.06-3.46 mol/L, and the dielectric constant of the organic solvent is 63 or less.

Description

非水電解液、半固体電解質層、二次電池用シート及び二次電池Non-aqueous electrolyte solution, semi-solid electrolyte layer, secondary battery sheet and secondary battery
　本発明は、非水電解液、半固体電解質層、二次電池用シート及び二次電池に関する。 The present invention relates to a non-aqueous electrolyte solution, a semi-solid electrolyte layer, a secondary battery sheet, and a secondary battery.
　各種二次電池に用いる非水電解液に関する従来技術として、特許文献１には、非水溶媒と、電解質塩と、所定の電位で酸化還元反応を生じる過充電制御剤とともに、熱安定性が高く、安定的に非水電解液中に残存する熱安定性塩、正極及び負極に保護皮膜を形成して過充電制御剤の分解を抑制する保護皮膜形成剤、又は遷移金属と錯体を形成する錯体形成剤の少なくとも一種とを含む、液状又はゲル状である非水電解質が開示されている。 As a prior art relating to a non-aqueous electrolyte solution used in various secondary batteries, Patent Document 1 describes a non-aqueous solvent, an electrolyte salt, and an overcharge control agent that causes an oxidation-reduction reaction at a predetermined potential, and has high thermal stability. , A heat-stable salt that stably remains in the non-aqueous electrolyte solution, a protective film-forming agent that forms a protective film on the positive and negative electrodes to suppress the decomposition of the overcharge control agent, or a complex that forms a complex with the transition metal. Liquid or gel-like non-aqueous electrolytes containing at least one of the forming agents are disclosed.
特開２０１２－２５６５０２号公報Japanese Unexamined Patent Publication No. 2012-256502
　前記特許文献１のリチウムイオン二次電池における電解液は、二次電池が比較的高温で運転された場合における二次電池の放電容量維持率を高いまま維持するには不十分であり、なお改良の余地があった。 The electrolytic solution in the lithium ion secondary battery of Patent Document 1 is insufficient to maintain a high discharge capacity retention rate of the secondary battery when the secondary battery is operated at a relatively high temperature, and is still improved. There was room for.
　本発明は、二次電池が比較的高温で運転された場合における二次電池の放電容量維持率を高いまま維持することができる非水電解液を提供することを目的とする。また、その非水電解液を用いた半固体電解質層、二次電池用シート及び二次電池を提供することを目的とする。 An object of the present invention is to provide a non-aqueous electrolytic solution capable of maintaining a high discharge capacity retention rate of a secondary battery when the secondary battery is operated at a relatively high temperature. Another object of the present invention is to provide a semi-solid electrolyte layer using the non-aqueous electrolyte solution, a sheet for a secondary battery, and a secondary battery.
　前記課題を解決するため、本発明の非水電解液は、電解質塩及び有機溶媒を含み、有機溶媒はスルホラン及びその誘導体からなる群から選択される少なくとも１種の主溶媒及び低粘度有機溶媒を含み、主溶媒に対する電解質塩の濃度は１．０６ｍｏｌ／Ｌ～３．４６ｍｏｌ／Ｌであり、有機溶媒の比誘電率は６３以下であることを特徴とする。
　本明細書は本願の優先権の基礎となる日本国特許出願番号2020-082631号の開示内容を包含する。 In order to solve the above problems, the non-aqueous electrolyte solution of the present invention contains an electrolyte salt and an organic solvent, and the organic solvent is at least one main solvent and a low-viscosity organic solvent selected from the group consisting of sulfolanes and derivatives thereof. The concentration of the electrolyte salt with respect to the main solvent is 1.06 mol / L to 3.46 mol / L, and the relative permittivity of the organic solvent is 63 or less.
This specification includes the disclosure of Japanese Patent Application No. 2020-082631, which is the basis of the priority of the present application.
　本発明の非水電解液により、二次電池が比較的高温で運転された場合における二次電池の放電容量維持率を高いまま維持することができる非水電解液が提供される。前記した以外の課題、構成及び効果は以下の実施形態の説明により明らかにされる。 The non-aqueous electrolyte solution of the present invention provides a non-aqueous electrolyte solution capable of maintaining a high discharge capacity retention rate of the secondary battery when the secondary battery is operated at a relatively high temperature. Issues, configurations and effects other than those described above will be clarified by the following description of the embodiments.
本発明の二次電池の一実施形態を示す断面図である。It is sectional drawing which shows one Embodiment of the secondary battery of this invention. 実施例及び比較例における主溶媒に対するリチウム塩濃度（ｍｏｌ／Ｌ）と４５℃の放電容量維持率（％）の関係を示すグラフである。It is a graph which shows the relationship between the lithium salt concentration (mol / L) with respect to the main solvent and the discharge capacity retention rate (%) at 45 degreeC in Examples and Comparative Examples. 実施例及び比較例における有機溶媒（混合溶媒）の比誘電率と４５℃の放電容量維持率（％）の関係を示すグラフである。It is a graph which shows the relationship between the relative permittivity of an organic solvent (mixed solvent) in an Example and a comparative example, and a discharge capacity retention rate (%) at 45 degreeC.
　以下、図面等を用いて、本発明の実施形態について説明する。以下の説明は本発明の内容の具体例を示すものであり、本発明がこれらの説明に限定されるものではなく、本明細書に開示される技術的思想の範囲内において当業者による様々な変更及び修正が可能である。また、本発明を説明するための全図において、同一の機能を有するものは、同一の符号を付け、その繰り返しの説明は省略する場合がある。 Hereinafter, embodiments of the present invention will be described with reference to drawings and the like. The following description shows specific examples of the contents of the present invention, and the present invention is not limited to these explanations. It can be changed and modified. Further, in all the drawings for explaining the present invention, those having the same function may be designated by the same reference numerals, and the repeated description thereof may be omitted.
　本明細書に記載される「～」は、その前後に記載される数値を下限値及び上限値として有する意味で使用する。上限値又は下限値が０の場合は、上限値又は下限値を含まない。本明細書に段階的に記載されている数値範囲において、一つの数値範囲で記載された上限値又は下限値は、他の段階的に記載されている上限値又は下限値に置き換えても良い。本明細書に記載される数値範囲の上限値又は下限値は、実施例中に示されている値に置き換えても良い。 "-" Described in this specification is used to mean that the numerical values described before and after it are used as the lower limit value and the upper limit value. When the upper limit value or the lower limit value is 0, the upper limit value or the lower limit value is not included. In the numerical range described stepwise in the present specification, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value described in another stepwise. The upper limit value or the lower limit value of the numerical range described in the present specification may be replaced with the value shown in the examples.
　本発明に係る二次電池の一実施形態として、リチウムイオン二次電池を例にして以下説明する。リチウムイオン二次電池とは、電解質中における電極へのリチウムイオンの吸蔵・放出により、電気エネルギーを貯蔵又は利用可能とする電気化学デバイスである。リチウムイオン二次電池は、リチウムイオン電池、非水電解質二次電池、非水電解液二次電池等の別の名称でも呼ばれており、いずれの電池も本発明の対象である。本発明の技術的思想は、ナトリウムイオン二次電池、マグネシウムイオン二次電池、カルシウムイオン二次電池、亜鉛二次電池、アルミニウムイオン二次電池等に対しても適用できる。 As an embodiment of the secondary battery according to the present invention, a lithium ion secondary battery will be described below as an example. A lithium ion secondary battery is an electrochemical device that stores or makes available electrical energy by storing and releasing lithium ions into electrodes in an electrolyte. Lithium-ion secondary batteries are also called by other names such as lithium-ion batteries, non-aqueous electrolyte secondary batteries, and non-aqueous electrolyte secondary batteries, and any of these batteries is the subject of the present invention. The technical idea of the present invention can also be applied to a sodium ion secondary battery, a magnesium ion secondary battery, a calcium ion secondary battery, a zinc secondary battery, an aluminum ion secondary battery and the like.
　以下で例示している材料群から材料を選択する場合、本明細書で開示されている内容と矛盾しない範囲で、材料を単独で選択しても良く、複数組み合わせて選択しても良い。また、本明細書で開示されている内容と矛盾しない範囲で、以下で例示している材料群以外の材料を選択しても良い。 When selecting a material from the material group illustrated below, the material may be selected alone or in combination within a range not inconsistent with the contents disclosed in the present specification. In addition, materials other than the material group illustrated below may be selected as long as they do not contradict the contents disclosed in the present specification.
　図１は、本発明の一実施形態に係るリチウムイオン二次電池の断面図である。図１は積層型のリチウムイオン二次電池を示しており、リチウムイオン二次電池１０００は、正極１００、負極２００、外装体５００及び絶縁層３００を有する。外装体５００は、絶縁層３００、正極１００及び負極２００を収容する。外装体５００は、アルミニウム、ステンレス鋼、ニッケルメッキ鋼等、非水電解液に対し耐食性のある材料群から選択される。リチウムイオン二次電池は、捲回型の構成にすることもできる。 FIG. 1 is a cross-sectional view of a lithium ion secondary battery according to an embodiment of the present invention. FIG. 1 shows a laminated lithium ion secondary battery, in which the lithium ion secondary battery 1000 has a positive electrode 100, a negative electrode 200, an exterior body 500, and an insulating layer 300. The exterior body 500 houses the insulating layer 300, the positive electrode 100, and the negative electrode 200. The exterior body 500 is selected from a group of materials having corrosion resistance to a non-aqueous electrolytic solution such as aluminum, stainless steel, and nickel-plated steel. The lithium ion secondary battery may also have a winding type configuration.
　リチウムイオン二次電池１０００内では、正極１００、絶縁層３００及び負極２００で構成される電極体４００が積層して電極群を構成する。以下では、正極１００又は負極２００を電極と称する場合がある。また、正極１００又は負極２００あるいはその両方と、絶縁層３００とが積層したものを二次電池用シートと称する場合がある。絶縁層３００及び電極を一体構造とした場合、二次電池用シートを積層するだけで電極群を作製できる。 In the lithium ion secondary battery 1000, an electrode body 400 composed of a positive electrode 100, an insulating layer 300, and a negative electrode 200 is laminated to form an electrode group. Hereinafter, the positive electrode 100 or the negative electrode 200 may be referred to as an electrode. Further, a sheet in which the positive electrode 100 and / or the negative electrode 200 and the insulating layer 300 are laminated may be referred to as a secondary battery sheet. When the insulating layer 300 and the electrodes are integrated, the electrode group can be produced only by laminating the secondary battery sheets.
　正極１００は、正極集電体１２０及び正極合剤層１１０を有する。正極集電体１２０の両面に正極合剤層１１０が形成されている。負極２００は、負極集電体２２０及び負極合剤層２１０を有する。負極集電体２２０の両面に負極合剤層２１０が形成されている。正極合剤層１１０又は負極合剤層２１０を電極合剤層、正極集電体１２０又は負極集電体２２０を電極集電体と称する場合がある。 The positive electrode 100 has a positive electrode current collector 120 and a positive electrode mixture layer 110. Positive electrode mixture layers 110 are formed on both sides of the positive electrode current collector 120. The negative electrode 200 has a negative electrode current collector 220 and a negative electrode mixture layer 210. Negative electrode mixture layers 210 are formed on both sides of the negative electrode current collector 220. The positive electrode mixture layer 110 or the negative electrode mixture layer 210 may be referred to as an electrode mixture layer, and the positive electrode current collector 120 or the negative electrode current collector 220 may be referred to as an electrode current collector.
　正極集電体１２０は正極タブ１３０を有する。負極集電体２２０は負極タブ２３０を有する。正極タブ１３０又は負極タブ２３０を電極タブと称する場合がある。電極タブ上には電極合剤層が形成されていない。ただし、リチウムイオン二次電池１０００の性能に悪影響を与えない範囲で電極タブ上に電極合剤層を形成しても良い。正極タブ１３０及び負極タブ２３０は、外装体５００の外部に突出しており、突出した複数の正極タブ１３０同士、複数の負極タブ２３０同士が、例えば超音波接合等で接合されることで、リチウムイオン二次電池１０００内で並列接続が形成される。本発明に係るリチウムイオン二次電池は、二次電池内に電気的な直列接続を備えるバイポーラ型の構成にすることもできる。 The positive electrode current collector 120 has a positive electrode tab 130. The negative electrode current collector 220 has a negative electrode tab 230. The positive electrode tab 130 or the negative electrode tab 230 may be referred to as an electrode tab. No electrode mixture layer is formed on the electrode tab. However, the electrode mixture layer may be formed on the electrode tab as long as the performance of the lithium ion secondary battery 1000 is not adversely affected. The positive electrode tab 130 and the negative electrode tab 230 project to the outside of the exterior body 500, and the plurality of protruding positive electrode tabs 130 and the plurality of negative electrode tabs 230 are bonded to each other by, for example, ultrasonic bonding, thereby forming lithium ions. A parallel connection is formed within the secondary battery 1000. The lithium ion secondary battery according to the present invention may also have a bipolar configuration having an electrical series connection inside the secondary battery.
　正極合剤層１１０は、正極活物質、正極導電剤及び正極バインダを含む。負極合剤層２１０は、負極活物質、負極導電剤及び負極バインダを含む。正極活物質又は負極活物質を電極活物質、正極導電剤又は負極導電剤を電極導電剤、正極バインダ又は負極バインダを電極バインダと称する場合がある。 The positive electrode mixture layer 110 contains a positive electrode active material, a positive electrode conductive agent, and a positive electrode binder. The negative electrode mixture layer 210 contains a negative electrode active material, a negative electrode conductive agent, and a negative electrode binder. The positive electrode active material or the negative electrode active material may be referred to as an electrode active material, the positive electrode conductive agent or the negative electrode conductive agent may be referred to as an electrode conductive agent, and the positive electrode binder or the negative electrode binder may be referred to as an electrode binder.
＜電極導電剤＞
　電極導電剤は、電極合剤層の導電性を向上させる。電極導電剤としては、ケッチェンブラック、アセチレンブラック、黒鉛等の材料群から適宜選択して用いることができる。 <Electrode conductive agent>
The electrode conductive agent improves the conductivity of the electrode mixture layer. As the electrode conductive agent, it can be appropriately selected and used from a material group such as Ketjen black, acetylene black, and graphite.
＜電極バインダ＞
　電極バインダは、電極中の電極活物質や電極導電剤等を結着させる。電極バインダとしては、スチレン－ブタジエンゴム（ＳＢＲ）、カルボキシメチルセルロ－ス（ＣＭＣ）、ポリフッ化ビニリデン（ＰＶＤＦ）、ビニリデンフルオライド（ＶＤＦ）とヘキサフルオロプロピレン（ＨＦＰ）との共重合体（Ｐ（ＶｄＦ－ＨＦＰ））等の材料群から適宜選択して用いることができる。 <Electrode binder>
The electrode binder binds the electrode active material, the electrode conductive agent, and the like in the electrode. As the electrode binder, a copolymer (P (P)) of styrene-butadiene rubber (SBR), carboxymethyl cellulose (CMC), polyvinylidene fluoride (PVDF), vinylidene fluoride (VDF) and hexafluoropropylene (HFP). It can be appropriately selected and used from a material group such as VdF-HFP)).
＜正極活物質＞
　貴な電位を示す正極活物質は、充電過程においてリチウムイオンが脱離し、放電過程において負極活物質から脱離したリチウムイオンが挿入される。正極活物質としては、遷移金属を有するリチウム複合酸化物が望ましい。具体的には、ＬｉＭＯ２、Ｌｉ過剰組成のＬｉ［ＬｉＭ］Ｏ２、ＬｉＭ２Ｏ４、ＬｉＭＰＯ４、ＬｉＭＶＯ４、ＬｉＭＢＯ３、Ｌｉ２ＭＳｉＯ４（ただし、Ｍは、Ｃｏ、Ｎｉ、Ｍｎ、Ｆｅ、Ｃｒ、Ｚｎ、Ｔａ、Ａｌ、Ｍｇ、Ｃｕ、Ｃｄ、Ｍｏ、Ｎｂ、Ｗ、Ｒｕ等から選択される少なくとも１種である）が挙げられる。また、これら材料における酸素の一部を、フッ素等の他の元素に置換しても良い。さらに、正極活物質は、ＴｉＳ２、ＭｏＳ２、Ｍｏ６Ｓ８、ＴｉＳｅ２等のカルコゲナイドや、Ｖ２Ｏ５等のバナジウム系酸化物、ＦｅＦ３等のハライド、ポリアニオンを構成するＦｅ（ＭｏＯ４）３、Ｆｅ２（ＳＯ４）３、Ｌｉ３Ｆｅ２（ＰＯ４）３等、キノン系有機結晶、酸素等の材料群から選択される少なくとも１種を含むことができる。 <Positive electrode active material>
Lithium ions are desorbed from the positive electrode active material showing a noble potential in the charging process, and lithium ions desorbed from the negative electrode active material are inserted in the discharging process. As the positive electrode active material, a lithium composite oxide having a transition metal is desirable. Specifically, LiMO 2 , Li excess composition Li [LiM] O 2 , LiM 2 O 4 , LiMPO 4 , LiMVO 4 , LiMBO 3 , Li 2 MSiO 4 (where M is Co, Ni, Mn, Fe). , Cr, Zn, Ta, Al, Mg, Cu, Cd, Mo, Nb, W, Ru and the like). Further, a part of oxygen in these materials may be replaced with another element such as fluorine. Further, the positive electrode active material includes chalcogenides such as TiS 2 , MoS 2 , Mo 6 S 8 and TiSe 2 , vanadium oxides such as V 2 O 5 , halides such as FeF 3 , and Fe (MoO 4) constituting polyanions. ) 3 , Fe 2 (SO 4 ) 3 , Li 3 Fe 2 (PO 4 ) 3, etc., can contain at least one selected from the material group such as quinone-based organic crystals and oxygen.
＜正極集電体１２０＞
　正極集電体１２０としては、厚さが１μｍ～１００μｍのアルミニウム箔、厚さが１０μｍ～１００μｍ、孔径０．１ｍｍ～１０ｍｍの孔を有するアルミニウム製穿孔箔、エキスパンドメタル、発泡金属板、ステンレス鋼、チタン等の材料等の材料群から適宜選択して用いることができる。 <Positive current collector 120>
The positive electrode current collector 120 includes an aluminum foil having a thickness of 1 μm to 100 μm, an aluminum perforated foil having a thickness of 10 μm to 100 μm and a hole diameter of 0.1 mm to 10 mm, an expanded metal, a foamed metal plate, and stainless steel. It can be appropriately selected and used from a material group such as a material such as titanium.
＜負極活物質＞
　卑な電位を示す負極活物質は、放電過程においてリチウムイオンが脱離し、充電過程において正極合剤層１１０中の正極活物質から脱離したリチウムイオンが挿入される。負極活物質としては、炭素系材料（黒鉛、易黒鉛化炭素材料、非晶質炭素材料、有機結晶、活性炭等）、導電性高分子材料（ポリアセン、ポリパラフェニレン、ポリアニリン、ポリアセチレン等）、リチウム複合酸化物（チタン酸リチウム：Ｌｉ４Ｔｉ５Ｏ１２やＬｉ２ＴｉＯ４等）、金属リチウム、リチウムと合金化する金属（アルミニウム、シリコン、スズ等を少なくとも１種類以上有する）やこれらの酸化物等の材料群から適宜選択して用いることができる。 <Negative electrode active material>
In the negative electrode active material showing a low potential, lithium ions are desorbed in the discharge process, and lithium ions desorbed from the positive electrode active material in the positive electrode mixture layer 110 are inserted in the charging process. Examples of the negative electrode active material include carbon-based materials (graphite, easily graphitized carbon material, amorphous carbon material, organic crystals, activated carbon, etc.), conductive polymer materials (polyacene, polyparaphenylene, polyaniline, polyacetylene, etc.), and lithium. Composite oxides (lithium titanate: Li 4 Ti 5 O 12 , Li 2 TiO 4, etc.), metallic lithium, metals alloying with lithium (having at least one type of aluminum, silicon, tin, etc.) and oxides thereof. It can be appropriately selected and used from the material group such as.
＜負極集電体２２０＞
　負極集電体２２０としては、厚さが１μｍ～１００μｍの銅箔、厚さが１μｍ～１００μｍ、孔径０．１ｍｍ～１０ｍｍの銅製穿孔箔、エキスパンドメタル、発泡金属板、ステンレス鋼、チタン、ニッケル等の材料群から適宜選択して用いることができる。 <Negative electrode current collector 220>
The negative electrode current collector 220 includes a copper foil having a thickness of 1 μm to 100 μm, a copper perforated foil having a thickness of 1 μm to 100 μm and a pore diameter of 0.1 mm to 10 mm, an expanded metal, a foamed metal plate, stainless steel, titanium, nickel, etc. It can be appropriately selected and used from the material group of.
＜電極＞
　電極活物質、電極導電剤、電極バインダ及び溶剤を混合した電極スラリーを、ドクターブレード法、ディッピング法、スプレー法等の塗工方法によって電極集電体へ付着させることで電極合剤層が作製される。溶剤は、Ｎ－メチルピロリドン（ＮＭＰ）、水等の材料群から選択される。その後、溶剤を除去するために電極合剤層を乾燥し、ロールプレスによって電極合剤層を加圧成形することにより電極が作製される。 <Electrode>
An electrode mixture layer is prepared by adhering an electrode slurry, which is a mixture of an electrode active material, an electrode conductive agent, an electrode binder, and a solvent, to an electrode current collector by a coating method such as a doctor blade method, a dipping method, or a spray method. NS. The solvent is selected from a group of materials such as N-methylpyrrolidone (NMP) and water. Then, the electrode mixture layer is dried to remove the solvent, and the electrode mixture layer is pressure-molded by a roll press to produce an electrode.
　電極合剤層に非水電解液が含まれている場合、電極合剤層中の非水電解液の含有量は２０体積％～４０体積％であることが望ましい。非水電解液の含有量が少ない場合、電極合剤層内部でのイオン伝導経路が十分に形成されずレート特性が低下する可能性がある。また、非水電解液の含有量が多い場合には、電極合剤層から非水電解液が漏れ出す可能性があることに加え、電極活物質の相対的な量が不十分となりエネルギー密度の低下を招く可能性がある。 When the electrode mixture layer contains a non-aqueous electrolyte solution, the content of the non-aqueous electrolyte solution in the electrode mixture layer is preferably 20% by volume to 40% by volume. When the content of the non-aqueous electrolyte solution is small, the ionic conduction path inside the electrode mixture layer may not be sufficiently formed and the rate characteristics may deteriorate. Further, when the content of the non-aqueous electrolyte solution is high, the non-aqueous electrolyte solution may leak from the electrode mixture layer, and the relative amount of the electrode active material becomes insufficient to increase the energy density. May lead to a decline.
　電極合剤層に非水電解液を含有させるためには、外装体５００の開いている一辺や注液孔からリチウムイオン二次電池１０００に非水電解液を注入し、電極合剤層の細孔に非水電解液を充填させて行うことができる。また、非水電解液、電極活物質、電極導電剤及び電極バインダを混合したスラリーを調製し、調製したスラリーを電極集電体上に一緒に塗布して、電極合剤層の細孔に非水電解液を充填させても良い。これにより、半固体電解質に含まれるような担持粒子を要せず、電極合剤層中の電極活物質や電極導電剤等の粒子が担持粒子として機能し、それらの粒子により非水電解液を保持することができる。 In order to contain the non-aqueous electrolytic solution in the electrode mixture layer, the non-aqueous electrolytic solution is injected into the lithium ion secondary battery 1000 through an open side of the exterior body 500 or a liquid injection hole, and the electrode mixture layer is thinned. This can be done by filling the pores with a non-aqueous electrolytic solution. In addition, a slurry in which a non-aqueous electrolyte solution, an electrode active material, an electrode conductive agent, and an electrode binder are mixed is prepared, and the prepared slurry is applied together on the electrode current collector to be applied to the pores of the electrode mixture layer. It may be filled with a water electrolyte. As a result, the supporting particles such as those contained in the semi-solid electrolyte are not required, and the particles such as the electrode active material and the electrode conductive agent in the electrode mixture layer function as the supporting particles, and these particles make the non-aqueous electrolyte solution. Can be retained.
　電極合剤層の厚さは、電極活物質の平均粒径以上とすることが望ましい。電極合剤層の厚さが小さいと、隣接する電極活物質間の電子伝導性が悪化する可能性がある。電極活物質粉末中に電極合剤層の厚さ以上の平均粒径を有する粗粒がある場合、ふるい分級、風流分級等により粗粒を予め除去し、電極合剤層の厚さ以下の粒子とすることが望ましい。 It is desirable that the thickness of the electrode mixture layer is equal to or greater than the average particle size of the electrode active material. If the thickness of the electrode mixture layer is small, the electron conductivity between adjacent electrode active materials may deteriorate. If the electrode active material powder contains coarse particles having an average particle size equal to or larger than the thickness of the electrode mixture layer, the coarse particles are removed in advance by sieving classification, wind flow classification, etc., and particles having a thickness equal to or less than the thickness of the electrode mixture layer. Is desirable.
＜絶縁層３００＞
　絶縁層３００は、正極１００と負極２００の間にイオンを伝達させる媒体となる。絶縁層３００は電子の絶縁体としても働き、正極１００と負極２００の短絡を防止する。絶縁層３００は、半固体電解質層を有することができる。絶縁層３００として、セパレータ及び半固体電解質層を併用しても良い。 <Insulation layer 300>
The insulating layer 300 serves as a medium for transmitting ions between the positive electrode 100 and the negative electrode 200. The insulating layer 300 also acts as an electron insulator to prevent a short circuit between the positive electrode 100 and the negative electrode 200. The insulating layer 300 can have a semi-solid electrolyte layer. As the insulating layer 300, a separator and a semi-solid electrolyte layer may be used in combination.
＜セパレータ＞
　セパレータとして、多孔質シートを用いることができる。多孔質シートは、セルロース、セルロースの変性体（カルボキシメチルセルロース（ＣＭＣ）、ヒドロキシプロピルセルロース（ＨＰＣ）等）、ポリオレフィン（ポリプロピレン（ＰＰ）、プロピレンの共重合体等）、ポリエステル（ポリエチレンテレフタレート（ＰＥＴ）、ポリエチレンナフタレート（ＰＥＮ）、ポリブチレンテレフタレート（ＰＢＴ）等）、ポリアクリロニトリル（ＰＡＮ）、ポリアラミド、ポリアミドイミド、ポリイミド等の樹脂、ガラス等の材料群から選択することができる。セパレータを正極１００又は負極２００よりも大面積にすることで、正極１００と負極２００の短絡を防止できる。 <Separator>
A porous sheet can be used as the separator. Porous sheets include cellulose, modified cellulose (carboxymethyl cellulose (CMC), hydroxypropyl cellulose (HPC), etc.), polyolefin (polypropylene (PP), propylene copolymer, etc.), polyester (polybutylene terephthalate (PET), etc.). Polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), etc.), polyacrylonitrile (PAN), polyaramid, polyamideimide, resins such as polyimide, and materials such as glass can be selected. By making the area of the separator larger than that of the positive electrode 100 or the negative electrode 200, a short circuit between the positive electrode 100 and the negative electrode 200 can be prevented.
　セパレータ粒子、セパレータバインダ及び溶剤を有するセパレータ形成用混合物を電極合剤層に塗布することにより、セパレータを形成しても良い。あるいは、セパレータ形成用混合物を前記の多孔質シートに塗布しても良い。 A separator may be formed by applying a separator forming mixture having separator particles, a separator binder and a solvent to the electrode mixture layer. Alternatively, the separator-forming mixture may be applied to the porous sheet.
　セパレータ粒子は、γ－アルミナ（Ａｌ２Ｏ３）、シリカ（ＳｉＯ２）、ジルコニア（ＺｒＯ２）等の材料群から選択される。セパレータ粒子の平均粒子径は、セパレータの厚さの１／１００～１／２とすることが望ましい。セパレータバインダは、ポリエチレン（ＰＥ）、ＰＰ、ポリテトラフルオロエチレン（ＰＴＦＥ）、ＰＶＤＦ、Ｐ（ＶｄＦ－ＨＦＰ）、スチレンブタジエンゴム（ＳＢＲ）、ポリアルギン酸、ポリアクリル酸等の材料等から適宜選択して用いることができる。 Separator particles are selected from a group of materials such as γ-alumina (Al 2 O 3 ), silica (SiO 2 ), and zirconia (ZrO 2). The average particle size of the separator particles is preferably 1/100 to 1/2 of the thickness of the separator. The separator binder is appropriately selected from materials such as polyethylene (PE), PP, polytetrafluoroethylene (PTFE), PVDF, P (VdF-HFP), styrene butadiene rubber (SBR), polyargic acid, and polyacrylic acid. Can be used.
　絶縁層３００がセパレータを含む場合、外装体５００の開いている一辺や注液孔からリチウムイオン二次電池１０００に非水電解液を注入することで、セパレータ中に非水電解液を充填することができる。 When the insulating layer 300 includes a separator, the separator is filled with the non-aqueous electrolytic solution by injecting the non-aqueous electrolytic solution into the lithium ion secondary battery 1000 from the open side of the exterior body 500 or the liquid injection hole. Can be done.
＜半固体電解質層＞
　半固体電解質層は、半固体電解質バインダ及び半固体電解質を有する。半固体電解質は、担持粒子及び非水電解液を有する。半固体電解質は、担持粒子の集合体によって形成される細孔を有し、その中に非水電解液が保持されている。半固体電解質中に非水電解液が保持されることによって、半固体電解質はリチウムイオンを透過させる。絶縁層３００として半固体電解質層を用い、電極合剤層に非水電解液が充填される場合、リチウムイオン二次電池１０００への非水電解液の注入は不要になる。 <Semi-solid electrolyte layer>
The semi-solid electrolyte layer has a semi-solid electrolyte binder and a semi-solid electrolyte. The semi-solid electrolyte has supported particles and a non-aqueous electrolyte solution. The semi-solid electrolyte has pores formed by aggregates of supported particles, in which the non-aqueous electrolyte solution is held. By retaining the non-aqueous electrolyte solution in the semi-solid electrolyte, the semi-solid electrolyte allows lithium ions to permeate. When a semi-solid electrolyte layer is used as the insulating layer 300 and the electrode mixture layer is filled with the non-aqueous electrolyte solution, it is not necessary to inject the non-aqueous electrolyte solution into the lithium ion secondary battery 1000.
　半固体電解質層は、非水電解液等の液体成分を含んでいながら、固体のような取扱いができ、半透明な自立膜であり得る。局所的には、非水電解液等の液体成分がリチウムイオン伝導を担うために高イオン伝導性を示す。すなわち、半固体電解質層は、固体が持つ高い安全性と液体が持つ高いイオン伝導特性の、両者の長所を併せ持つ。 The semi-solid electrolyte layer can be treated like a solid while containing a liquid component such as a non-aqueous electrolyte solution, and can be a translucent self-supporting membrane. Locally, a liquid component such as a non-aqueous electrolyte solution is responsible for lithium ion conduction, so that it exhibits high ion conductivity. That is, the semi-solid electrolyte layer has the advantages of both the high safety of the solid and the high ionic conduction characteristics of the liquid.
　半固体電解質層の作製方法として、半固体電解質の粉末を成型ダイス等でペレット状に圧縮成型する方法や、半固体電解質バインダを半固体電解質の粉末に添加・混合し、シート化する方法等がある。半固体電解質バインダを半固体電解質の粉末に添加・混合することにより、柔軟性の高いシート状の半固体電解質層を作製することができる。分散溶媒に半固体電解質バインダを溶解させた結着剤の溶液を、半固体電解質に添加・混合し、電極等の基材上に混合物を塗布し、乾燥により分散溶媒を留去することで、半固体電解質層を作製しても良い。 As a method for producing the semi-solid electrolyte layer, there are a method of compression molding the semi-solid electrolyte powder into pellets with a molding die or the like, and a method of adding and mixing the semi-solid electrolyte binder to the semi-solid electrolyte powder to form a sheet. be. By adding and mixing the semi-solid electrolyte binder to the powder of the semi-solid electrolyte, a highly flexible sheet-shaped semi-solid electrolyte layer can be produced. A solution of a binder in which a semi-solid electrolyte binder is dissolved in a dispersion solvent is added to and mixed with the semi-solid electrolyte, the mixture is applied on a substrate such as an electrode, and the dispersion solvent is distilled off by drying. A semi-solid electrolyte layer may be prepared.
＜担持粒子＞
　担持粒子としては、電気化学的安定性の観点から、絶縁性粒子であり非水電解液に不溶であることが好ましい。担持粒子は、ＳｉＯ２粒子、Ａｌ２Ｏ３粒子、セリア（ＣｅＯ２）粒子、ＺｒＯ２粒子等の酸化物無機粒子、固体電解質等の材料群から適宜選択して用いることができる。担持粒子として酸化物無機粒子を用いることにより、半固体電解質層内で非水電解液を高濃度で保持することができる。また、酸化物無機粒子からガスが発生することがないため、大気中でのロールｔｏロールプロセスにより半固体電解質層を作製することができる。固体電解質は、Ｌｉ－Ｌａ－Ｚｒ－Ｏ等の酸化物系固体電解質や、Ｌｉ１０Ｇｅ２ＰＳ１２等の硫化物系固体電解質等の材料群から適宜選択して用いることができる。 <Supported particles>
From the viewpoint of electrochemical stability, the supported particles are preferably insulating particles and insoluble in a non-aqueous electrolytic solution. The supporting particles can be appropriately selected from a group of materials such as SiO 2 particles, Al 2 O 3 particles, Celia (CeO 2 ) particles, oxide inorganic particles such as ZrO 2 particles, and a solid electrolyte. By using the oxide-inorganic particles as the supporting particles, the non-aqueous electrolyte solution can be held at a high concentration in the semi-solid electrolyte layer. Further, since gas is not generated from the oxide inorganic particles, a semi-solid electrolyte layer can be produced by a roll-to-roll process in the atmosphere. The solid electrolyte can be appropriately selected and used from a material group such as an oxide-based solid electrolyte such as Li-La-Zr-O and a sulfide-based solid electrolyte such as Li 10 Ge 2 PS 12.
　非水電解液の保持量は担持粒子の比表面積に比例すると考えられるため、担持粒子の一次粒子の平均粒径は、１ｎｍ～１０μｍであることが好ましい。担持粒子の一次粒子の平均粒径が大きいと、担持粒子が十分な量の非水電解液を適切に保持できず半固体電解質の形成が困難になる可能性がある。また、担持粒子の一次粒子の平均粒径が小さいと、担持粒子間の表面間力が大きくなって担持粒子同士が凝集し易くなり、半固体電解質の形成が困難になる可能性がある。担持粒子の一次粒子の平均粒径は、１ｎｍ～５０ｎｍの範囲がより好ましく、１ｎｍ～１０ｎｍの範囲がさらに好ましい。担持粒子の一次粒子の平均粒径は、ＴＥＭを用いて測定することができる。 Since the holding amount of the non-aqueous electrolytic solution is considered to be proportional to the specific surface area of the supported particles, the average particle size of the primary particles of the supported particles is preferably 1 nm to 10 μm. If the average particle size of the primary particles of the supporting particles is large, the supporting particles may not be able to properly hold a sufficient amount of the non-aqueous electrolyte solution, and it may be difficult to form a semi-solid electrolyte. Further, if the average particle size of the primary particles of the supported particles is small, the intersurface force between the supported particles becomes large and the supported particles tend to aggregate with each other, which may make it difficult to form a semi-solid electrolyte. The average particle size of the primary particles of the supported particles is more preferably in the range of 1 nm to 50 nm, further preferably in the range of 1 nm to 10 nm. The average particle size of the primary particles of the supported particles can be measured using a TEM.
＜非水電解液＞
　非水電解液は、主溶媒、当該主溶媒と異なる比誘電率を有する低粘度有機溶媒、電解質塩、及び任意の負極界面安定化材を含む。主溶媒は、高い比誘電率を有し、リチウム塩の解離でリチウムイオンの濃度を高める効果を有する。主溶媒は、スルホラン及びその誘導体からなる群から選択される少なくとも１種（「スルホラン及び／又はその誘導体」とも称する）である。したがって、主溶媒は、スルホラン及びその誘導体からなる群から選択される２種以上、例えば２種、３種、又は４種の溶媒を含んでいても良い。スルホラン及び／又はその誘導体は、電解質塩とともに溶媒和イオン液体を構成する。以下の説明では、スルホラン及び／又はその誘導体を主溶媒と称する場合がある。非水電解液に含まれる成分はＮＭＲ等で測定することができる。主溶媒と低粘度有機溶媒の比誘電率は、比誘電率測定装置で計測できる。 <Non-aqueous electrolyte>
The non-aqueous electrolyte solution contains a main solvent, a low-viscosity organic solvent having a relative permittivity different from that of the main solvent, an electrolyte salt, and an optional negative electrode interface stabilizer. The main solvent has a high relative permittivity and has the effect of increasing the concentration of lithium ions by dissociating the lithium salt. The main solvent is at least one selected from the group consisting of sulfolanes and derivatives thereof (also referred to as "sulfolanes and / or derivatives thereof"). Therefore, the main solvent may contain two or more kinds, for example, two kinds, three kinds, or four kinds of solvents selected from the group consisting of sulfolane and its derivatives. Sulfolanes and / or derivatives thereof, together with electrolyte salts, constitute solvated ionic liquids. In the following description, sulfolane and / or its derivative may be referred to as a main solvent. The components contained in the non-aqueous electrolytic solution can be measured by NMR or the like. The relative permittivity of the main solvent and the low-viscosity organic solvent can be measured by a relative permittivity measuring device.
　半固体電解質層中の非水電解液の含有量は特には限定されないが、４０体積％～９０体積％であることが望ましい。非水電解液の含有量が小さい場合、電極と半固体電解質層との界面抵抗が増加する可能性がある。また、非水電解液の含有量が大きい場合、半固体電解質層から非水電解液が漏れ出してしまう虞がある。半固体電解質層がシート状である場合、半固体電解質層中の非水電解液の含有量は５０体積％～８０体積％、さらには６０体積％～８０体積％であることが望ましい。半固体電解質と分散溶媒に半固体電解質バインダを溶解させた溶液との混合物を電極上に塗布することによって半固体電解質層を形成する場合、半固体電解質層中の非水電解液の含有量は４０体積％～６０体積％であることが望ましい。 The content of the non-aqueous electrolyte solution in the semi-solid electrolyte layer is not particularly limited, but is preferably 40% by volume to 90% by volume. If the content of the non-aqueous electrolyte solution is small, the interfacial resistance between the electrode and the semi-solid electrolyte layer may increase. Further, when the content of the non-aqueous electrolyte solution is large, the non-aqueous electrolyte solution may leak from the semi-solid electrolyte layer. When the semi-solid electrolyte layer is in the form of a sheet, the content of the non-aqueous electrolyte solution in the semi-solid electrolyte layer is preferably 50% by volume to 80% by volume, more preferably 60% by volume to 80% by volume. When a semi-solid electrolyte layer is formed by applying a mixture of a semi-solid electrolyte and a solution of a semi-solid electrolyte binder in a dispersion solvent on an electrode, the content of the non-aqueous electrolyte solution in the semi-solid electrolyte layer is It is preferably 40% by volume to 60% by volume.
　非水電解液における主溶媒の重量比率は、特には限定されないが、リチウムイオン二次電池の安定性の観点から、また高速充放電を可能にするため、非水電解液における主溶媒の重量比率は３０重量％（ｗｔ％）～７０重量％、特に４０重量％～６０重量％、さらには４５重量％～５５重量％であることが望ましい。 The weight ratio of the main solvent in the non-aqueous electrolyte solution is not particularly limited, but from the viewpoint of stability of the lithium ion secondary battery and in order to enable high-speed charging / discharging, the weight ratio of the main solvent in the non-aqueous electrolyte solution is not particularly limited. Is preferably 30% by weight (wt%) to 70% by weight, particularly 40% by weight to 60% by weight, and more preferably 45% by weight to 55% by weight.
＜溶媒和イオン液体＞
　溶媒和イオン液体は、スルホラン及び／又はその誘導体と、電解質塩とを有する。スルホラン及び／又はその誘導体を含む溶媒和イオン液体を用いると、スルホラン及び／又はその誘導体とリチウムイオンとで固有の配位構造をとるため、半固体電解質層中でのリチウムイオンの輸送速度が速くなる。したがって、粘度を高くするにつれて二次電池の入出力特性が低下するエーテル系溶媒及び電解質塩を有する溶媒和イオン液体とは異なり、溶媒和イオン液体の粘度を高くしても、溶媒和イオン液体を有する二次電池の入出力特性の低下を抑制することができる。 <Solvation ionic liquid>
The solvated ionic liquid has a sulfolane and / or a derivative thereof and an electrolyte salt. When a solvated ionic liquid containing sulfolane and / or a derivative thereof is used, the transport rate of lithium ions in the semi-solid electrolyte layer is high because the sulfolane and / or its derivative and lithium ions have a unique coordination structure. Become. Therefore, unlike the solvent-based ionic liquid having an ether solvent and an electrolyte salt in which the input / output characteristics of the secondary battery decrease as the viscosity increases, even if the viscosity of the solvent-containing ionic liquid is increased, the solvent-containing ionic liquid can be used. It is possible to suppress deterioration of the input / output characteristics of the secondary battery.
　スルホランの誘導体としては、スルホラン環を構成する炭素原子に結合する水素原子がフッ素原子やアルキル基等により置換されたものが挙げられる。具体例として、フルオロスルホラン、ジフルオロスルホラン、メチルスルホラン等の材料群から適宜選択して用いることができる。 Examples of the sulfolane derivative include those in which the hydrogen atom bonded to the carbon atom constituting the sulfolane ring is replaced with a fluorine atom, an alkyl group or the like. As a specific example, it can be appropriately selected and used from a material group such as fluorosulfolane, difluorosulfolane, and methylsulfolane.
＜電解質塩＞
　電解質塩としては、低粘度有機溶媒に均一に分散できるものが望ましく、カチオンがリチウムである場合、各種のリチウム塩を用いることができる。電解質塩として、テトラフルオロホウ酸リチウム（ＬｉＢＦ４）、リチウムビス（トリフルオロメタンスルホニル）イミド（ＬｉＴＦＳＩ）、リチウムビス（フルオロスルホニル）イミド（ＬｉＦＳＩ）、ＬｉＣｌＯ４、リチウムビス（フルオロスルホニル）アミド（ＬｉＦＳＡ）、リチウムビス（トリフルオロメタンスルホニル）アミド（ＬｉＴＦＳＡ）、それらの２種以上の混合物等の材料群から前記の条件を満たす材料を適宜選択して用いることができる。電解質塩としてＬｉＢＦ４を用いることが望ましい。ＬｉＢＦ４は黒鉛等の負極活物質に対して安定であり、二次電池の容量を高めることができる。 <Electrolyte salt>
As the electrolyte salt, one that can be uniformly dispersed in a low-viscosity organic solvent is desirable, and when the cation is lithium, various lithium salts can be used. As electrolyte salts, lithium tetrafluoroborate (LiBF 4 ), lithium bis (trifluoromethanesulfonyl) imide (LiTFSI), lithium bis (fluorosulfonyl) imide (LiFSI), LiClO 4 , lithium bis (fluorosulfonyl) amide (LiFSA) , Lithium bis (trifluoromethanesulfonyl) amide (LiTFSA), a mixture of two or more of them, and the like, a material satisfying the above conditions can be appropriately selected and used. It is desirable to use LiBF 4 as the electrolyte salt. LiBF 4 is stable with respect to a negative electrode active material such as graphite, and can increase the capacity of a secondary battery.
　スルホラン及び／又はその誘導体と電解質塩とを有する溶媒和イオン液体は、見かけ上の組成として一体的に表記することができる。例えば、スルホランとＬｉＴＦＳＩからなる溶媒和イオン液体は、見かけ上の組成としてＬｉ（ＳＬ）ｘＴＦＳＩ（ｘ＝２～６）と表記し、この組成を有する単一の物質としてモル数を算出する。 The solvated ionic liquid having a sulfolane and / or a derivative thereof and an electrolyte salt can be integrally described as an apparent composition. For example, a solvated ionic liquid composed of sulfolane and LiTFSI is expressed as Li (SL) x TFSI (x = 2 to 6) as an apparent composition, and the number of moles is calculated as a single substance having this composition.
　主溶媒に対する電解質塩の濃度は、１．０６ｍｏｌ／Ｌ～３．４６ｍｏｌ／Ｌであることが望ましい。濃度が高すぎると、粘度が上昇して高抵抗化し、容量が低下する傾向がある。濃度が低すぎると、溶媒が不安定化して寿命特性が低下する傾向がある。 The concentration of the electrolyte salt with respect to the main solvent is preferably 1.06 mol / L to 3.46 mol / L. If the concentration is too high, the viscosity tends to increase, the resistance increases, and the capacity tends to decrease. If the concentration is too low, the solvent tends to be unstable and the life characteristics tend to deteriorate.
＜低粘度有機溶媒＞
　低粘度有機溶媒は、主溶媒と異なる比誘電率を有する、溶媒和イオン液体よりも粘度の低い有機溶媒である。したがって、低粘度有機溶媒と溶媒和イオン液体とを混合することで、溶媒和イオン液体の粘度を下げ、イオン伝導率を向上させることができる。また、非水電解液の内部抵抗が大きい場合、低粘度有機溶媒を添加して非水電解液のイオン伝導率を高めることにより、非水電解液の内部抵抗を下げることができる。 <Low viscosity organic solvent>
The low-viscosity organic solvent is an organic solvent having a relative permittivity different from that of the main solvent and having a lower viscosity than the solvated ionic liquid. Therefore, by mixing the low-viscosity organic solvent and the solvated ionic liquid, the viscosity of the solvated ionic liquid can be lowered and the ionic conductivity can be improved. When the internal resistance of the non-aqueous electrolytic solution is large, the internal resistance of the non-aqueous electrolytic solution can be reduced by adding a low-viscosity organic solvent to increase the ionic conductivity of the non-aqueous electrolytic solution.
　低粘度溶媒としては、炭酸エチレン（ＥＣ）、炭酸プロピレン（ＰＣ）、炭酸１，２－ブチレン（ＢＣ）、炭酸フルオロエチレン（ＦＥＣ）等の環状の炭酸エステルや、炭酸メチルエチル（ＥＭＣ）、炭酸ジメチル（ＤＭＣ）、炭酸ジエチル（ＤＥＣ）等の非環状エステル、リン酸トリメチル（ＴＭＰ）、リン酸トリエチル（ＴＥＰ）、亜リン酸トリス（２，２，２－トリフルオロエチル）（ＴＦＰ）、メチルホスホン酸ジメチル（ＤＭＭＰ）等のリン酸エステル、γ－ブチロラクトン（ＧＢＬ）等のラクトン、それらの２種以上の混合物等の材料群から適宜選択して用いることができる。 Examples of the low-viscosity solvent include cyclic carbonate esters such as ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate (BC), and fluoroethylene carbonate (FEC), methyl ethyl carbonate (EMC), and carbonic acid. Acyclic esters such as dimethyl (DMC) and diethyl carbonate (DEC), trimethyl phosphate (TMP), triethyl phosphate (TEP), tris phosphite (2,2,2-trifluoroethyl) (TFP), methylphosphon It can be appropriately selected and used from a material group such as a phosphate ester such as dimethyl acid (DMMP), a lactone such as γ-butyrolactone (GBL), and a mixture of two or more thereof.
　非水電解液が１種以上の主溶媒及び１種以上の低粘度有機溶媒を含む場合、混合溶媒（主溶媒＋低粘度有機溶媒）の比誘電率Ｚは、第ｉの主溶媒の比誘電率をｐｉ、混合溶媒中の第ｉの主溶媒のモル比をｑｉ、第ｉの低粘度有機溶媒の比誘電率をｐ’ｉ、混合溶媒中の第ｉの低粘度有機溶媒のモル比をｑ’ｉとしたとき、
Figure JPOXMLDOC01-appb-M000001
 （式中、ｎは混合溶媒中に含まれる主溶媒の種類の数であり、ｍは混合溶媒中に含まれる低粘度有機溶媒の種類の数である）
で表わすことができ、Ｚは、６３以下になることが望ましい。 When the non-aqueous electrolyte solution contains one or more main solvents and one or more low-viscosity organic solvents, the relative dielectric constant Z of the mixed solvent (main solvent + low-viscosity organic solvent) is the relative dielectric of the i-th main solvent. the rate p i, the molar ratio of the main solvent of the i in a mixed solvent q i, the relative dielectric constant of the low viscosity organic solvent p 'i of the i, moles of low viscosity organic solvent of the i in a mixed solvent when the ratio was q 'i,
Figure JPOXMLDOC01-appb-M000001
 (In the formula, n is the number of types of the main solvent contained in the mixed solvent, and m is the number of types of the low-viscosity organic solvent contained in the mixed solvent.)
It can be represented by, and Z is preferably 63 or less.
　例えば、非水電解液が１種の主溶媒及び１種の低粘度有機溶媒を含む場合、混合溶媒（主溶媒＋低粘度有機溶媒）の比誘電率Ｚは、主溶媒の比誘電率をｐ、混合溶媒中の主溶媒のモル比をｑ、低粘度有機溶媒の比誘電率をｐ’、混合溶媒中の低粘度有機溶媒のモル比をｑ’としたとき、
Ｚ＝ｐ×ｑ＋ｐ’×ｑ’　　・・・式（２）
で表わすことができ、Ｚは、６３以下になることが望ましい。 For example, when the non-aqueous electrolyte solution contains one kind of main solvent and one kind of low-viscosity organic solvent, the relative dielectric constant Z of the mixed solvent (main solvent + low-viscosity organic solvent) is the relative dielectric constant of the main solvent. When the molar ratio of the main solvent in the mixed solvent is q, the specific dielectric constant of the low-viscosity organic solvent is p', and the molar ratio of the low-viscosity organic solvent in the mixed solvent is q',
Z = p × q + p'× q'・ ・ ・ Equation (2)
It can be represented by, and Z is preferably 63 or less.
　溶媒和イオン液体に比誘電率が低い低粘度有機溶媒を添加することで、溶媒和イオン液体の粘度を低減することができる。一方で、溶媒和イオン液体に低粘度有機溶媒を添加しすぎると、リチウム塩の解離度が低下して良質なＳＥＩ（Ｓｏｌｉｄ　Ｅｌｅｃｔｒｏｌｙｔｅ　Ｉｎｔｅｒｐｈａｓｅ）を形成することができず、高温（４５℃）での寿命特性が低下してしまう。したがって、Ｚを６３以下にすることによって、溶媒和イオン液体の粘度を低減しつつ、リチウム塩の解離度の低下を抑制することができ、高温（４５℃）での寿命特性を向上することができる。混合溶媒中の主溶媒のモル比と混合溶媒中の低粘度有機溶媒のモル比の測定方法はＮＭＲで測定できる。 By adding a low-viscosity organic solvent having a low relative permittivity to the solvated ionic liquid, the viscosity of the solvated ionic liquid can be reduced. On the other hand, if a low-viscosity organic solvent is added too much to the solvated ionic liquid, the degree of dissociation of the lithium salt is lowered and high-quality SEI (Solid Electrolyte Interphase) cannot be formed, and the temperature is high (45 ° C.). Life characteristics are reduced. Therefore, by setting Z to 63 or less, it is possible to suppress a decrease in the dissociation degree of the lithium salt while reducing the viscosity of the solvated ionic liquid, and it is possible to improve the life characteristics at a high temperature (45 ° C.). can. The method for measuring the molar ratio of the main solvent in the mixed solvent and the molar ratio of the low-viscosity organic solvent in the mixed solvent can be measured by NMR.
＜負極界面安定化材＞
　非水電解液が負極界面安定化材を含むことにより、二次電池のレート特性の向上や電池寿命の向上を図ることができる。負極界面安定化材は、ビニレンカーボネート（ＶＣ）、フルオロエチレンカーボネート（ＦＥＣ）等の材料群から適宜選択して用いることができる。 <Negative electrode interface stabilizer>
Since the non-aqueous electrolyte solution contains the negative electrode interface stabilizer, the rate characteristics of the secondary battery can be improved and the battery life can be improved. The negative electrode interface stabilizer can be appropriately selected from a group of materials such as vinylene carbonate (VC) and fluoroethylene carbonate (FEC).
＜腐食防止剤＞
　非水電解液は、必要に応じて腐食防止剤を含んでいても良い。腐食防止剤により、正極集電体１２０が高い電気化学電位に晒されても金属が溶出しにくい皮膜が形成される。腐食防止剤としては、ＰＦ６やＢＦ４といったアニオン種を含み、且つ、水分を含んだ大気で安定な化合物を形成するための強い化学結合を有するカチオン種を含む材料が望ましい。 <Corrosion inhibitor>
The non-aqueous electrolyte solution may contain a corrosion inhibitor, if necessary. The corrosion inhibitor forms a film in which the metal does not easily elute even when the positive electrode current collector 120 is exposed to a high electrochemical potential. As the corrosion inhibitor, a material containing an anionic species such as PF 6 or BF 4 and containing a cation species having a strong chemical bond for forming a stable compound in a water-containing atmosphere is desirable.
　大気で安定な化合物であることを示す一指標としては、水に対する溶解度や加水分解の有無を挙げることができる。腐食防止剤が固体である場合、水に対する溶解度が１％未満であることが望ましい。また、加水分解の有無は、水と混合後の試料の分子構造解析で評価することができる。ここで、加水分解しない、とは、腐食防止剤が吸湿あるいは水と混和した後、１００℃以上で加熱して水分を除去し、残留物の９５％が当初の腐食防止剤と同じ分子構造を示していることを意味する。 As one index showing that the compound is stable in the atmosphere, the solubility in water and the presence or absence of hydrolysis can be mentioned. When the corrosion inhibitor is a solid, it is desirable that the solubility in water is less than 1%. In addition, the presence or absence of hydrolysis can be evaluated by molecular structure analysis of the sample after mixing with water. Here, "not hydrolyzed" means that after the corrosion inhibitor absorbs moisture or mixes with water, it is heated at 100 ° C. or higher to remove water, and 95% of the residue has the same molecular structure as the original corrosion inhibitor. Means showing.
　腐食防止剤は、（Ｍ－Ｒ）＋Ａｎ－と表される。（Ｍ－Ｒ）＋Ａｎ－のカチオンは（Ｍ－Ｒ）＋である。Ｍは、窒素（Ｎ）、ホウ素（Ｂ）、リン（Ｐ）又は硫黄（Ｓ）から選択される。Ｒは炭化水素基から構成される。 Corrosion inhibitor, (M-R) + An - denoted. (M-R) + An - cation is (M-R) +. M is selected from nitrogen (N), boron (B), phosphorus (P) or sulfur (S). R is composed of a hydrocarbon group.
　（Ｍ－Ｒ）＋Ａｎ－のアニオンはＡｎ－である。Ａｎ－としては、ＢＦ４ －やＰＦ６ －が好適に用いられる。腐食防止剤のアニオンをＢＦ４ －やＰＦ６ －にすることで、正極集電体１２０の溶出を効率的に抑制できる。これは、ＢＦ４ －やＰＦ６ －のＦアニオンが電極集電体のＳＵＳやアルミニウムと反応し、不動態皮膜を形成することが影響するためと考えられる。 (M-R) + An - of the anion An - is. An - The, BF 4 - or PF 6 - it is preferably used. The anions of corrosion inhibitor BF 4 - or PF 6 - is to be in, it can be efficiently suppressed the elution of the positive electrode current collector 120. This, BF 4 - or PF 6 - F anions react with SUS and aluminum electrode current collector is believed to be due to the effect of forming a passive film.
　腐食防止剤は、テトラブチルアンモニウムヘキサフルオロホスフェート（ＴＢＡＰＦ６）、テトラブチルアンモニウムテトラフルオロボレート（ＴＢＡＢＦ４）等の４級アンモニウム塩、１－エチル－３－メチルイミダゾリウムテトラフルオロボレート（ＥＭＩ－ＢＦ４）、１－エチル－３－メチルイミダゾリウムヘキサフルオロホスフェート（ＥＭＩ－ＰＦ６）、１－ブチル－３－メチルイミダゾリウムテトラフルオロボレート（ＢＭＩ－ＢＦ４）、１－ブチル－３－メチルイミダゾリウムヘキサフルオロホスフェート（ＢＭＩ－ＰＦ６）等のイミダゾリウム塩等の材料群から適宜選択して用いることができる。特に、アニオンがＰＦ６ －であれば、正極集電体１２０の溶出を好適に抑制できる。 Corrosion inhibitors are quaternary ammonium salts such as tetrabutylammonium hexafluorophosphate (TBAPF 6 ) and tetrabutylammonium tetrafluorobolate (TBABF 4 ), 1-ethyl-3-methylimidazolium tetrafluorobolate (EMI-BF 4). ), 1-Ethyl-3-methylimidazolium hexafluorophosphate (EMI-PF 6 ), 1-butyl-3-methylimidazolium tetrafluorobolate (BMI-BF 4 ), 1-butyl-3-methylimidazolium hexa. It can be appropriately selected and used from a material group such as an imidazolium salt such as fluorophosphate (BMI-PF 6). In particular, when the anion is PF 6 − , the elution of the positive electrode current collector 120 can be suitably suppressed.
　腐食防止剤の含有量は、非水電解液の総重量に対して、０．５重量％～２０重量％であることが望ましく、より好ましくは１重量％～１０重量％である。腐食防止剤の含有量が少ないと、電極集電体の溶出を抑制する効果が低下し、充放電に伴い電池容量が低下する可能性がある。また、腐食防止剤の含有量が多いと、リチウムイオン伝導度が低下し、さらに、腐食防止剤を分解させるために多くの蓄電エネルギーが消費されてしまい、結果として電池容量が低下する可能性がある。 The content of the corrosion inhibitor is preferably 0.5% by weight to 20% by weight, more preferably 1% by weight to 10% by weight, based on the total weight of the non-aqueous electrolyte solution. If the content of the corrosion inhibitor is small, the effect of suppressing the elution of the electrode current collector is reduced, and the battery capacity may be reduced with charging and discharging. In addition, if the content of the corrosion inhibitor is high, the lithium ion conductivity is lowered, and a large amount of stored energy is consumed to decompose the corrosion inhibitor, which may result in a decrease in battery capacity. be.
＜半固体電解質バインダ＞
　半固体電解質バインダとしては、フッ素系の樹脂が好適に用いられる。フッ素系の樹脂は、ＰＴＦＥ、ＰＶＤＦ、Ｐ（ＶｄＦ－ＨＦＰ）等の材料群から適宜選択して用いることができる。ＰＶＤＦやＰ（ＶｄＦ－ＨＦＰ）を用いることで、絶縁層３００と電極集電体の密着性が向上するため、電池性能が向上する。 <Semi-solid electrolyte binder>
As the semi-solid electrolyte binder, a fluorine-based resin is preferably used. The fluorine-based resin can be appropriately selected and used from a material group such as PTFE, PVDF, and P (VdF-HFP). By using PVDF or P (VdF-HFP), the adhesion between the insulating layer 300 and the electrode current collector is improved, so that the battery performance is improved.
＜半固体電解質＞
　非水電解液が担持粒子に担持又は保持されることにより半固体電解質が構成される。半固体電解質の作製方法として、非水電解液と担持粒子とを特定の体積比率で混合し、メタノール等の有機溶媒を添加し・混合して、半固体電解質のスラリーを調合した後、スラリーをシャーレ等に広げ、有機溶媒を留去して半固体電解質の粉末を得る方法等が挙げられる。 <Semi-solid electrolyte>
A semi-solid electrolyte is formed by supporting or holding the non-aqueous electrolyte solution on the supporting particles. As a method for producing a semi-solid electrolyte, a non-aqueous electrolyte solution and a supporting particle are mixed in a specific volume ratio, an organic solvent such as methanol is added and mixed to prepare a semi-solid electrolyte slurry, and then the slurry is prepared. Examples thereof include a method of spreading it on a chalet or the like and distilling off an organic solvent to obtain a powder of a semi-solid electrolyte.
　以下、実施例及び比較例を挙げて本発明をさらに具体的に説明するが、本発明はこれらの実施例に限定されるものではない。 Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.
＜実施例１＞
＜非水電解液の作製＞
　電解質塩としてリチウム塩（Ｌｉ塩）であるリチウムビス（トリフルオロメタンスルホニル）アミド（ＬｉＴＦＳＡ）、主溶媒としてスルホラン（ＳＬ）、低粘度溶媒として炭酸プロピレン（ＰＣ）、負極界面安定化材として黒鉛皮膜形成材であるビニレンカーボネート（ＶＣ）、腐食防止剤としてＡｌ集電箔抑制添加剤であるテトラブチルアンモニウムヘキサフルオロホスフェート（ＴＢＡ－ＰＦ６）を、それぞれ秤量し、これらを混合して非水電解液を作製した。作製した非水電解液に含まれる成分をＮＭＲで定量した。その結果、主溶媒（ＳＬ）と低粘度溶媒（ＰＣ）のモル比は６５．４：３４．６であり、リチウム塩濃度は２．３７ｍｏｌ／Ｌであった。 <Example 1>
<Preparation of non-aqueous electrolyte solution>
Lithium bis (trifluoromethanesulfonyl) amide (LiTFSA), which is a lithium salt (Li salt), is used as an electrolyte salt, sulfolane (SL) is used as a main solvent, propylene carbonate (PC) is used as a low-viscosity solvent, and a graphite film is formed as a negative electrode interface stabilizer. Vinylene carbonate (VC), which is a material, and tetrabutylammonium hexafluorophosphate (TBA-PF 6 ), which is an Al current collector foil suppression additive as a corrosion inhibitor, are weighed and mixed to prepare a non-aqueous electrolyte solution. Made. The components contained in the prepared non-aqueous electrolytic solution were quantified by NMR. As a result, the molar ratio of the main solvent (SL) to the low-viscosity solvent (PC) was 65.4: 34.6, and the lithium salt concentration was 2.37 mol / L.
＜正極の作製＞
　正極活物質としてＬｉＮｉ１／３Ｃｏ１／３Ｍｎ１／３Ｏ２系酸化物、正極導電剤としてアセチレンブラック、正極バインダとしてＮ－メチルピロリドンに溶解させたＰＶＤＦを、固形分の重量比が９４：４：２の比率となるようにそれぞれ秤量し、これらを混錬機で均一に混合した。得られた混合物は、ＮＭＰを加えてスラリー化し、所定の固形分濃度に調整した。次いで、濃度が調整されたスラリーを正極集電箔であるアルミ箔の両面に卓上コーターで塗布し、１２０℃の乾燥炉に通して正極を得た。正極合剤（正極活物質＋正極導電剤＋正極バインダ）の塗工量は、両面の合計を３０．１ｍｇ／ｃｍ２とした。得られた正極は、ロールプレスで電極密度を３．１５ｇ／ｃｍ３に調整した。 <Preparation of positive electrode>
LiNi 1/3 Co 1/3 Mn 1/3 O 2 based oxide as a positive electrode active material, acetylene black as a cathode electrical conductor, the PVDF dissolved in N- methylpyrrolidone as a positive electrode binder, the weight ratio of the solids 94 Each was weighed so as to have a ratio of: 4: 2, and these were uniformly mixed in a kneader. The obtained mixture was slurried by adding NMP to adjust the solid content concentration. Next, the slurry whose concentration was adjusted was applied to both sides of the aluminum foil, which is the positive electrode current collecting foil, with a tabletop coater, and passed through a drying furnace at 120 ° C. to obtain a positive electrode. The total amount of the positive electrode mixture (positive electrode active material + positive electrode conductive agent + positive electrode binder) was 30.1 mg / cm 2 on both sides. The electrode density of the obtained positive electrode was adjusted to 3.15 g / cm 3 by a roll press.
＜負極の作製＞
　負極活物質として黒鉛、負極バインダとしてスチレン－ブタジエンゴムとカルボキシルメチルセルロースを、固形分の重量比が９８：１：１の比率となるようにそれぞれ秤量し、これらを混錬機で均一に混合した。得られた混合物は、水を加えてスラリー化し、所定の固形分濃度に調整した。次いで、濃度が調整されたスラリーを負極集電箔である銅箔の両面に卓上コーターで塗布し、１００℃の乾燥炉に通して負極を得た。負極合剤（負極活物質＋負極バインダ）の塗工量は、両面の合計を１８．１ｍｇ／ｃｍ２とした。得られた負極は、ロールプレスで電極密度を１．５５ｇ／ｃｍ３に調整した。 <Manufacturing of negative electrode>
Graphite as the negative electrode active material and styrene-butadiene rubber and carboxylmethyl cellulose as the negative electrode binder were weighed so that the weight ratio of the solid content was 98: 1: 1, and these were uniformly mixed by a kneader. The obtained mixture was slurried by adding water to adjust the solid content concentration. Next, the slurry whose concentration was adjusted was applied to both sides of the copper foil, which is the negative electrode current collecting foil, with a tabletop coater, and passed through a drying furnace at 100 ° C. to obtain a negative electrode. The amount of the negative electrode mixture (negative electrode active material + negative electrode binder) applied was 18.1 mg / cm 2 in total on both sides. The electrode density of the obtained negative electrode was adjusted to 1.55 g / cm 3 by a roll press.
＜セパレータの形成＞
　セパレータを、不揮発性電解質を電極合剤層の表面に塗工して形成した。はじめに、担持粒子として平均粒径が１μｍであるＳｉＯ２と、バインダとしてビニリデンフルオライド－ヘキサフルオロプロピレン共重合体（Ｐ（ＶｄＦ－ＨＦＰ））を、重量比が８９．３：１０．７の比率となるようにそれぞれ秤量し、これらを混錬機で均一に混合した。得られた混合物は、ＮＭＰを加えてスラリー化し、所定の固形分濃度に調整した。次いで、濃度が調整されたスラリーを正極と負極の両面に卓上コーターで塗布し、１００℃の乾燥炉に通して、不揮発性電解質層を形成した正極と負極を得た。 <Formation of separator>
The separator was formed by applying a non-volatile electrolyte to the surface of the electrode mixture layer. First, SiO 2 having an average particle size of 1 μm as the supporting particles and vinylidene fluoride-hexafluoropropylene copolymer (P (VdF-HFP)) as the binder have a weight ratio of 89.3: 10.7. Each was weighed so as to be, and these were uniformly mixed in a kneader. The obtained mixture was slurried by adding NMP to adjust the solid content concentration. Next, the slurry having the adjusted concentration was applied to both the positive electrode and the negative electrode with a tabletop coater and passed through a drying oven at 100 ° C. to obtain a positive electrode and a negative electrode having a non-volatile electrolyte layer formed therein.
＜二次電池の作製＞
＜組み立て＞
　作製した正極と負極を、エアー式打ち抜き機で、正極合剤層が４５ｍｍ×７０ｍｍ、負極合剤層が４７ｍｍ×７４ｍｍとなるよう打ち抜き、正極及び負極にタブ部を形成した。次いで、正極と負極を１００℃で２時間乾燥して電極中のＮＭＰを除去した。乾燥させた正極を、厚みが３０μｍであり、ＰＰ／ＰＥ／ＰＰの３層構造である樹脂製の微多孔膜に挟み込み、タブ部が形成されている辺以外の３辺を熱溶着した。 <Making secondary batteries>
<Assembly>
The prepared positive electrode and negative electrode were punched with an air punching machine so that the positive electrode mixture layer had a size of 45 mm × 70 mm and the negative electrode mixture layer had a size of 47 mm × 74 mm, and tab portions were formed on the positive electrode and the negative electrode. Then, the positive electrode and the negative electrode were dried at 100 ° C. for 2 hours to remove NMP in the electrodes. The dried positive electrode was sandwiched between microporous films made of resin having a thickness of 30 μm and a three-layer structure of PP / PE / PP, and three sides other than the side on which the tab portion was formed were heat-welded.
　微多孔膜で覆った正極と、打ち抜いた負極を、負極／正極／負極の順に積層した後、負極上に厚さ５０μｍのＰＴＦＥ製のシートを配置した。正極と負極に設けた各タブ部とアルミニウム製の正極端子、ニッケル製の負極端子とを、それぞれ、超音波溶接によって溶接した。得られた電極体をラミネートフィルムに挟み込み、注液用の１辺を残し、タブ部が形成された辺を含む３辺をラミネート封止装置によって２００℃で熱封止し、５０℃で２０時間真空乾燥させた。次いで、注液用の１辺から非水電解液を注入した後、注液用の１辺を真空封止して二次電池を得た。 A positive electrode covered with a microporous film and a punched negative electrode were laminated in the order of negative electrode / positive electrode / negative electrode, and then a 50 μm-thick PTFE sheet was placed on the negative electrode. Each tab portion provided on the positive electrode and the negative electrode, an aluminum positive electrode terminal, and a nickel negative electrode terminal were welded by ultrasonic welding, respectively. The obtained electrode body is sandwiched between laminate films, one side for liquid injection is left, and three sides including the side on which the tab portion is formed are heat-sealed at 200 ° C. by a laminate sealing device for 20 hours at 50 ° C. It was vacuum dried. Next, after injecting a non-aqueous electrolytic solution from one side for liquid injection, one side for liquid injection was vacuum-sealed to obtain a secondary battery.
＜放電容量の測定＞
（１）初期放電容量の測定
　作製した二次電池を２５℃で保持し、充電レート０．０５Ｃで上限電圧４．２Ｖまで定電流（ＣＣ）充電した後、電圧を４．２Ｖに維持したまま、電流値が０．００５Ｃに減少するまで定電圧（ＣＶ）充電した。その後、放電レート０．０５Ｃで下限電圧２．７Ｖまで定電流放電させて、二次電池の初期放電容量を計測した。 <Measurement of discharge capacity>
(1) Measurement of initial discharge capacity The prepared secondary battery is held at 25 ° C., charged with a constant current (CC) up to an upper limit voltage of 4.2 V at a charging rate of 0.05 C, and then the voltage is maintained at 4.2 V. , Constant voltage (CV) charging was performed until the current value decreased to 0.005C. Then, a constant current discharge was performed at a discharge rate of 0.05 C to a lower limit voltage of 2.7 V, and the initial discharge capacity of the secondary battery was measured.
（２）４５℃でのサイクル試験
　初期放電容量を測定後、二次電池を４５℃に昇温し、０．３Ｃでの充放電を１００サイクル繰り返した。 (2) Cycle test at 45 ° C. After measuring the initial discharge capacity, the temperature of the secondary battery was raised to 45 ° C., and charging / discharging at 0.3 C was repeated for 100 cycles.
（３）サイクル試験後の放電容量の測定
　サイクル試験後の二次電池の温度を２５℃に下げ、その温度を保持し、充電レート０．０５Ｃで上限電圧４．２ＶまでＣＣ充電した後、電圧を４．２Ｖに維持したまま、電流値が０．００５Ｃに減少するまでＣＶ充電した。その後、放電レート０．０５Ｃで下限電圧２．７ＶまでＣＣ放電させて、二次電池のサイクル試験後の放電容量を計測した。 (3) Measurement of discharge capacity after cycle test The temperature of the secondary battery after the cycle test is lowered to 25 ° C, the temperature is maintained, CC charging is performed to the upper limit voltage of 4.2 V at a charging rate of 0.05 C, and then the voltage is applied. Was CV charged until the current value decreased to 0.005 C while maintaining the voltage at 4.2 V. Then, CC discharge was performed at a discharge rate of 0.05 C to a lower limit voltage of 2.7 V, and the discharge capacity of the secondary battery after the cycle test was measured.
（４）４５℃放電容量維持率の算出
　（１）で測定した初期放電容量に対する（３）で測定したサイクル試験後の放電容量の割合から求められる４５℃放電容量維持率を１００サイクル寿命として評価した。
４５℃放電容量維持率（％）（１００サイクル寿命）＝（サイクル試験後の放電容量／初期放電容量）×１００　　・・・式（３） (4) Calculation of 45 ° C discharge capacity retention rate The 45 ° C discharge capacity retention rate obtained from the ratio of the discharge capacity after the cycle test measured in (3) to the initial discharge capacity measured in (1) is evaluated as 100 cycle life. bottom.
45 ° C. Discharge capacity retention rate (%) (100 cycle life) = (Discharge capacity after cycle test / Initial discharge capacity) x 100 ... Equation (3)
＜実施例２～１２、比較例１～２＞
　非水電解液の組成を表１のように変更した以外は実施例１と同様にして二次電池を作製し、非水電解液に含まれる成分の定量と放電容量の計測を行った。 <Examples 2 to 12, Comparative Examples 1 to 2>
A secondary battery was produced in the same manner as in Example 1 except that the composition of the non-aqueous electrolyte solution was changed as shown in Table 1, and the components contained in the non-aqueous electrolyte solution were quantified and the discharge capacity was measured.
　表１に、実施例１～１２及び比較例１～２の二次電池の組成及び４５℃放電容量維持率を示す。図２に、実施例及び比較例における主溶媒に対するリチウム塩濃度（ｍｏｌ／Ｌ）と４５℃の放電容量維持率（％）の関係を示し、図３に、実施例及び比較例における混合溶媒の比誘電率と４５℃の放電容量維持率（％）の関係を示す。 Table 1 shows the composition of the secondary batteries of Examples 1 to 12 and Comparative Examples 1 and 2 and the 45 ° C. discharge capacity retention rate. FIG. 2 shows the relationship between the lithium salt concentration (mol / L) with respect to the main solvent in Examples and Comparative Examples and the discharge capacity retention rate (%) at 45 ° C., and FIG. 3 shows the relationship between the mixed solvents in Examples and Comparative Examples. The relationship between the relative permittivity and the discharge capacity retention rate (%) at 45 ° C. is shown.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
＜結果と考察＞
　図２では、リチウム塩濃度に対して二次電池の４５℃放電容量維持率をプロットした。図２に示すように、リチウム塩濃度が２．２１ｍｏｌ／Ｌよりも小さい組成では、４５℃放電容量維持率が小さくなり、リチウム塩濃度が２．２１ｍｏｌ／Ｌ以上の組成では、４５℃放電容量維持率が大きくなった。この結果は、粘度が低い低粘度有機溶媒と溶媒和イオン液体とを混合することで、非水電解液の粘度が低下し、非水電解液のイオン伝導率が高くなったことによると考えられる。なお、リチウム塩濃度が２．２１ｍｏｌ／Ｌよりも大きい組成では、濃度が低いほど４５℃放電容量維持率が大きくなる傾向がみられた。これは、濃度が低い方が、溶媒がリチウムイオンに配位して安定化されたためであると考えられる。 <Results and discussion>
In FIG. 2, the 45 ° C. discharge capacity retention rate of the secondary battery was plotted against the lithium salt concentration. As shown in FIG. 2, when the lithium salt concentration is smaller than 2.21 mol / L, the 45 ° C. discharge capacity retention rate becomes small, and when the lithium salt concentration is 2.21 mol / L or more, the 45 ° C. discharge capacity is reduced. The maintenance rate has increased. This result is considered to be due to the fact that by mixing a low-viscosity organic solvent with low viscosity and a solvated ionic liquid, the viscosity of the non-aqueous electrolyte solution decreased and the ionic conductivity of the non-aqueous electrolyte solution increased. .. When the lithium salt concentration was higher than 2.21 mol / L, the lower the concentration, the higher the 45 ° C. discharge capacity retention rate tended to be. It is considered that this is because the lower the concentration, the more the solvent is coordinated to the lithium ions and stabilized.
　図２より、二次電池の４５℃放電容量維持率Ｙは、リチウム塩濃度が０．８ｍｏｌ／Ｌ～３．８ｍｏｌ／Ｌの範囲において、リチウム塩濃度Ｘにより、次の式（４）で表されることが確認された。
　Ｙ＝－４．０１６７Ｘ２＋１８．１３Ｘ＋７３．０７４　　・・・式（４） From FIG. 2, the 45 ° C. discharge capacity retention rate Y of the secondary battery is represented by the following formula (4) according to the lithium salt concentration X in the range of the lithium salt concentration of 0.8 mol / L to 3.8 mol / L. It was confirmed that it would be done.
Y = -4.0167X 2 + 18.13X + 73.574 ... Equation (4)
　式（４）によると、比較例１（リチウム塩濃度Ｘ＝１）の４５℃放電容量維持率（８７．７％）よりも、４５℃放電容量維持率が大きくなるリチウム塩濃度Ｘの範囲は、１．０６ｍｏｌ／Ｌ～３．４６ｍｏｌ／Ｌであった。二次電池の４５℃放電容量維持率が８９．５％以上になるリチウム塩濃度Ｘの範囲は、１．２５ｍｏｌ／Ｌ～３．２６ｍｏｌ／Ｌであった。また、二次電池の４５℃放電容量維持率が９０％以上になるリチウム塩濃度Ｘの範囲は、１．３２ｍｏｌ／Ｌ～３．１８ｍｏｌ／Ｌであった。さらに、二次電池の４５℃放電容量維持率が９２％以上になるリチウム塩濃度Ｘの範囲は、１．６４ｍｏｌ／Ｌ～２．８６ｍｏｌ／Ｌであった。したがって、リチウム塩濃度Ｘの範囲は、１．０６ｍｏｌ／Ｌ～３．４６ｍｏｌ／Ｌ、好ましくは１．２５ｍｏｌ／Ｌ～３．２６ｍｏｌ／Ｌ、より好ましくは１．３２ｍｏｌ／Ｌ～３．１８ｍｏｌ／Ｌである。 According to the formula (4), the range of the lithium salt concentration X at which the 45 ° C. discharge capacity retention rate is larger than the 45 ° C. discharge capacity retention rate (87.7%) of Comparative Example 1 (lithium salt concentration X = 1) is , 1.06 mol / L to 3.46 mol / L. The range of the lithium salt concentration X at which the 45 ° C. discharge capacity retention rate of the secondary battery was 89.5% or more was 1.25 mol / L to 3.26 mol / L. The range of the lithium salt concentration X at which the 45 ° C. discharge capacity retention rate of the secondary battery is 90% or more was 1.32 mol / L to 3.18 mol / L. Further, the range of the lithium salt concentration X at which the 45 ° C. discharge capacity retention rate of the secondary battery is 92% or more was 1.64 mol / L to 2.86 mol / L. Therefore, the range of the lithium salt concentration X is 1.06 mol / L to 3.46 mol / L, preferably 1.25 mol / L to 3.26 mol / L, and more preferably 1.32 mol / L to 3.18 mol / L. Is.
　図３では、非水電解液における混合溶媒の比誘電率に対して二次電池の４５℃放電容量維持率をプロットした。図３に示すように、比誘電率が約３１．５よりも小さい組成では、比誘電率が大きいほど、４５℃放電容量維持率が大きくなった。一方、比誘電率が約３１．５よりも大きい組成では、比誘電率が小さいほど、４５℃放電容量維持率が大きくなった。電解質塩の解離に影響を及ぼす比誘電率が高いほど、電解質塩を高濃度で添加した場合に、溶媒の黒鉛表面での還元分解が顕著になるため、４５℃放電容量維持率が小さくなると考えられる。 In FIG. 3, the 45 ° C. discharge capacity retention rate of the secondary battery was plotted against the relative permittivity of the mixed solvent in the non-aqueous electrolyte solution. As shown in FIG. 3, in a composition having a relative permittivity smaller than about 31.5, the larger the relative permittivity, the larger the 45 ° C. discharge capacity retention rate. On the other hand, in a composition having a relative permittivity larger than about 31.5, the smaller the relative permittivity, the larger the 45 ° C. discharge capacity retention rate. It is considered that the higher the relative permittivity that affects the dissociation of the electrolyte salt, the more remarkable the reduction decomposition of the solvent on the graphite surface when the electrolyte salt is added at a high concentration, and the smaller the discharge capacity retention rate at 45 ° C. Be done.
　ここで、主溶媒の比誘電率をＡとし、混合溶媒中の主溶媒のモル比をＭとし、低粘度有機溶媒の比誘電率をＢとし、混合溶媒中の低粘度有機溶媒のモル比をＮとした場合、混合溶媒の比誘電率Ｔは、次の式（５）で定義できる。
　Ｔ＝Ａ×Ｍ＋Ｂ×Ｎ　　・・・式（５） Here, the relative permittivity of the main solvent is A, the molar ratio of the main solvent in the mixed solvent is M, the relative permittivity of the low-viscosity organic solvent is B, and the molar ratio of the low-viscosity organic solvent in the mixed solvent is When N is set, the relative permittivity T of the mixed solvent can be defined by the following formula (5).
T = A × M + B × N ・ ・ ・ Equation (5)
　したがって、図３より、二次電池の４５℃放電容量維持率Ｙは、混合溶媒の比誘電率Ｔにより、次の式（６）で表されることが確認された。
　Ｙ＝－０．００６５Ｔ２＋０．４１Ｔ＋８８　　・・・式（６） Therefore, from FIG. 3, it was confirmed that the 45 ° C. discharge capacity retention rate Y of the secondary battery is represented by the following formula (6) by the relative permittivity T of the mixed solvent.
Y = -0.0065T 2 + 0.41T + 88 ... Equation (6)
　式（６）によると、比較例１の二次電池の４５℃放電容量維持率（８７．７％）よりも、４５℃放電容量維持率が大きくなる混合溶媒の比誘電率Ｔの範囲は、６３以下であった。二次電池の４５℃放電容量維持率Ｚが８９．５％以上になる混合溶媒の比誘電率Ｔの範囲は、３．９～５９であった。また、二次電池の４５℃放電容量維持率が９０％以上になる混合溶媒の比誘電率Ｔの範囲は、５．５～５８であった。さらに、二次電池の４５℃放電容量維持率が９２％以上になる混合溶媒の比誘電率Ｔの範囲は、１２．５～５１．０であった。したがって、混合溶媒の比誘電率Ｔの範囲は、６３以下、好ましくは３．９～５９、より好ましくは５．５～５８である。 According to the formula (6), the range of the relative permittivity T of the mixed solvent in which the 45 ° C. discharge capacity retention rate is larger than the 45 ° C. discharge capacity retention rate (87.7%) of the secondary battery of Comparative Example 1 is It was 63 or less. The range of the relative permittivity T of the mixed solvent in which the 45 ° C. discharge capacity retention rate Z of the secondary battery was 89.5% or more was 3.9 to 59. Further, the range of the relative permittivity T of the mixed solvent at which the 45 ° C. discharge capacity retention rate of the secondary battery is 90% or more was 5.5 to 58. Further, the range of the relative permittivity T of the mixed solvent at which the 45 ° C. discharge capacity retention rate of the secondary battery is 92% or more was 12.5 to 51.0. Therefore, the range of the relative permittivity T of the mixed solvent is 63 or less, preferably 3.9 to 59, and more preferably 5.5 to 58.
１００　　　正極
１１０　　　正極合剤層
１２０　　　正極集電体
１３０　　　正極タブ
２００　　　負極
２１０　　　負極合剤層
２２０　　　負極集電体
２３０　　　負極タブ
３００　　　絶縁層
４００　　　電極体
５００　　　外装体
１０００　　リチウムイオン二次電池
　本明細書で引用した全ての刊行物、特許及び特許出願はそのまま引用により本明細書に組み入れられるものとする。 100 Positive electrode 110 Positive electrode mixture layer 120 Positive electrode current collector 130 Positive electrode tab 200 Negative electrode 210 Negative electrode mixture layer 220 Negative electrode current collector 230 Negative electrode tab 300 Insulation layer 400 Electrode body 500 Exterior body 1000 Lithium ion secondary battery Cited herein. All published publications, patents and patent applications are incorporated herein by reference in their entirety.

Claims (6)

  1. 　電解質塩及び有機溶媒を含む非水電解液であって、
    　有機溶媒が、スルホラン及びその誘導体からなる群から選択される少なくとも１種の主溶媒、及び低粘度有機溶媒を含み、
    　主溶媒に対する電解質塩の濃度が、１．０６ｍｏｌ／Ｌ～３．４６ｍｏｌ／Ｌであり、　有機溶媒の比誘電率が、６３以下である
    非水電解液。     A non-aqueous electrolyte solution containing an electrolyte salt and an organic solvent.
    The organic solvent comprises at least one main solvent selected from the group consisting of sulfolanes and derivatives thereof, and a low viscosity organic solvent.
    A non-aqueous electrolyte solution in which the concentration of the electrolyte salt with respect to the main solvent is 1.06 mol / L to 3.46 mol / L, and the relative permittivity of the organic solvent is 63 or less.
  2. 　低粘度有機溶媒が、炭酸エチレン、炭酸プロピレン、炭酸１，２－ブチレン、炭酸フルオロエチレン、炭酸メチルエチル、炭酸ジメチル、炭酸ジエチル、リン酸トリメチル、リン酸トリエチル、亜リン酸トリス（２，２，２－トリフルオロエチル）、メチルホスホン酸ジメチル及びγ－ブチロラクトンからなる群から選択される少なくとも１種を含む、請求項１に記載の非水電解液。 Low-viscosity organic solvents include ethylene carbonate, propylene carbonate, 1,2-butylene carbonate, fluoroethylene carbonate, methyl ethyl carbonate, dimethyl carbonate, diethyl carbonate, trimethyl phosphate, triethyl phosphate, tris phosphite (2,2). The non-aqueous electrolyte solution according to claim 1, which comprises at least one selected from the group consisting of 2-trifluoroethyl), dimethyl methylphosphonate and γ-butyrolactone.
  3. 　電解質塩が、テトラフルオロホウ酸リチウム及びリチウムビス（トリフルオロメタンスルホニル）アミドからなる群から選択される少なくとも１種を含む、請求項１に記載の非水電解液。 The non-aqueous electrolyte solution according to claim 1, wherein the electrolyte salt contains at least one selected from the group consisting of lithium tetrafluoroborate and lithium bis (trifluoromethanesulfonyl) amide.
  4. 　請求項１に記載の非水電解液、担持粒子及び半固体電解質バインダを含む半固体電解質層。 A semi-solid electrolyte layer containing the non-aqueous electrolyte solution, supporting particles and a semi-solid electrolyte binder according to claim 1.
  5. 　正極及び／又は負極と、請求項４に記載の半固体電解質層とが積層されてなる二次電池用シート。 A secondary battery sheet in which a positive electrode and / or a negative electrode and the semi-solid electrolyte layer according to claim 4 are laminated.
  6. 　正極と、
    　負極と、
    　前記正極及び前記負極の間に配置される請求項４に記載の半固体電解質層と、
    を備える二次電池。     With the positive electrode
    With the negative electrode
    The semi-solid electrolyte layer according to claim 4, which is arranged between the positive electrode and the negative electrode.
    Rechargeable battery with.
PCT/JP2021/015591 2020-05-08 2021-04-15 Non-aqueous electrolytic solution, semi-solid electrolyte layer, sheet for secondary battery, and secondary battery WO2021225065A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202180028662.8A CN115461907A (en) 2020-05-08 2021-04-15 Nonaqueous electrolyte solution, semisolid electrolyte layer, sheet for secondary battery, and secondary battery

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2020-082631 2020-05-08
JP2020082631A JP2021177470A (en) 2020-05-08 2020-05-08 Nonaqueous electrolyte solution, semisolid electrolyte layer, secondary battery sheet and secondary battery

Publications (1)

Publication Number Publication Date
WO2021225065A1 true WO2021225065A1 (en) 2021-11-11

Family

ID=78409664

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2021/015591 WO2021225065A1 (en) 2020-05-08 2021-04-15 Non-aqueous electrolytic solution, semi-solid electrolyte layer, sheet for secondary battery, and secondary battery

Country Status (3)

Country Link
JP (1) JP2021177470A (en)
CN (1) CN115461907A (en)
WO (1) WO2021225065A1 (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003045485A (en) * 2001-07-26 2003-02-14 Sanyo Electric Co Ltd Secondary lithium battery
JP2007328978A (en) * 2006-06-07 2007-12-20 Matsushita Electric Ind Co Ltd Nonaqueous electrolyte secondary battery
WO2012172723A1 (en) * 2011-06-15 2012-12-20 パナソニック株式会社 Non-aqueous solvent and non-aqueous electrolytic solution for electrical storage devices, and electrical storage device, lithium secondary battery and electric double-layer capacitor each utilizing said non-aqueous solvent and said non-aqueous electrolytic solution
WO2013187487A1 (en) * 2012-06-15 2013-12-19 三菱化学株式会社 Nonaqueous electrolyte secondary cell and method for using same
JP2019016430A (en) * 2017-07-03 2019-01-31 株式会社日立製作所 Secondary battery and method for manufacturing the same

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003045485A (en) * 2001-07-26 2003-02-14 Sanyo Electric Co Ltd Secondary lithium battery
JP2007328978A (en) * 2006-06-07 2007-12-20 Matsushita Electric Ind Co Ltd Nonaqueous electrolyte secondary battery
WO2012172723A1 (en) * 2011-06-15 2012-12-20 パナソニック株式会社 Non-aqueous solvent and non-aqueous electrolytic solution for electrical storage devices, and electrical storage device, lithium secondary battery and electric double-layer capacitor each utilizing said non-aqueous solvent and said non-aqueous electrolytic solution
WO2013187487A1 (en) * 2012-06-15 2013-12-19 三菱化学株式会社 Nonaqueous electrolyte secondary cell and method for using same
JP2019016430A (en) * 2017-07-03 2019-01-31 株式会社日立製作所 Secondary battery and method for manufacturing the same

Also Published As

Publication number Publication date
JP2021177470A (en) 2021-11-11
CN115461907A (en) 2022-12-09

Similar Documents

Publication Publication Date Title
TWI686977B (en) Semi-solid electrolyte layer, battery cell sheet and secondary battery
JP6818723B2 (en) Electrolyte for electrochemical devices and electrochemical devices
JP4959465B2 (en) Non-aqueous electrolyte for lithium secondary batteries with excellent high-temperature storage characteristics
WO2019176174A1 (en) Positive electrode slurry, positive electrode, cell sheet, secondary battery
JP2013062164A (en) Nonaqueous electrolyte for electrochemical element, and electrochemical element
CN110521049B (en) Semi-solid electrolyte, electrode with semi-solid electrolyte layer, and secondary battery
JP3587982B2 (en) Polymer solid electrolyte and lithium secondary battery and electric double layer capacitor using the same
JP7270210B2 (en) Non-aqueous electrolyte, semi-solid electrolyte layer, sheet for secondary battery and secondary battery
WO2021225065A1 (en) Non-aqueous electrolytic solution, semi-solid electrolyte layer, sheet for secondary battery, and secondary battery
JP2020202158A (en) Insulation layer, battery cell sheet, and battery cell
WO2021111847A1 (en) Non-aqueous electrolyte, semi-solid electrolyte layer, sheet for secondary battery, and secondary battery
JP2020004598A (en) battery
WO2020066058A1 (en) Nonaqueous electrolytic solution, nonvolatile electrolyte, and secondary battery
US20190295783A1 (en) Electrolyte liquid for electrochemical device and electrochemical device
WO2020213268A1 (en) Nonaqueous electrolytic solution, nonvolatile electrolyte, and secondary battery
WO2019142502A1 (en) Negative electrode, half secondary battery and secondary battery
WO2019198329A1 (en) Insulation layer, battery cell sheet, and battery
CN110506357B (en) Semi-secondary battery and secondary battery
WO2019225077A1 (en) Cell sheet and cell
JP2019083095A (en) Positive electrode mixture layer, positive electrode, semi secondary battery, and secondary battery
JP2019061812A (en) Lithium ion secondary battery

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: 21800352

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21800352

Country of ref document: EP

Kind code of ref document: A1