WO2019225077A1 - Feuille cellulaire et cellule - Google Patents

Feuille cellulaire et cellule Download PDF

Info

Publication number
WO2019225077A1
WO2019225077A1 PCT/JP2019/005260 JP2019005260W WO2019225077A1 WO 2019225077 A1 WO2019225077 A1 WO 2019225077A1 JP 2019005260 W JP2019005260 W JP 2019005260W WO 2019225077 A1 WO2019225077 A1 WO 2019225077A1
Authority
WO
WIPO (PCT)
Prior art keywords
electrode
cell sheet
nail
battery cell
positive electrode
Prior art date
Application number
PCT/JP2019/005260
Other languages
English (en)
Japanese (ja)
Inventor
誠之 廣岡
栄二 關
純 川治
篤 宇根本
西村　悦子
阿部　誠
西村　勝憲
Original Assignee
株式会社日立製作所
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 filed Critical 株式会社日立製作所
Publication of WO2019225077A1 publication Critical patent/WO2019225077A1/fr

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
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • H01M50/497—Ionic conductivity
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/443—Particulate material
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a battery cell sheet and a battery.
  • a coating layer 4 which is a microporous, non-electrically conductive polymer compound having a tensile elongation of 200% or more was formed.
  • Patent Document 1 has the following description as a technique for preventing a large short-circuit current from flowing into a nonaqueous electrolyte secondary battery. Since the coating layer, which is a microporous, non-electrically conductive polymer compound with a tensile elongation of 200% or more, is used, the side surface of the positive and negative electrodes is formed by elastic deformation of the coating layer when the nail is pulled out. There is a possibility that the coating layer is not formed, a part is generated, a short circuit occurs between the positive and negative electrodes, and the safety of the battery is impaired.
  • the coating layer which is a microporous, non-electrically conductive polymer compound with a tensile elongation of 200% or more
  • the present invention aims to improve battery safety.
  • Sectional drawing of a secondary battery The fragmentary sectional view of a secondary battery.
  • the structure and result of an Example and a comparative example The voltage and temperature change of an Example and a comparative example.
  • ⁇ Described in this specification is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.
  • the upper limit value or lower limit value described in one numerical range may be replaced with the upper limit value or lower limit value described in another stepwise manner.
  • the upper limit value or lower limit value of the numerical ranges described in the present specification may be replaced with the values shown in the examples.
  • a lithium ion secondary battery is an electrochemical device that can store or use electrical energy by occluding / releasing lithium ions to and from an electrode in an electrolyte. This is called by another name of a lithium ion battery, a non-aqueous electrolyte secondary battery, and a non-aqueous electrolyte secondary battery, and any battery is a subject of the present invention.
  • the technical idea of the present invention can also be applied to sodium ion secondary batteries, magnesium ion secondary batteries, calcium ion secondary batteries, zinc secondary batteries, aluminum ion secondary batteries, and the like.
  • FIG. 1 is a cross-sectional view of a secondary battery according to an embodiment of the present invention.
  • FIG. 1 shows a stacked secondary battery.
  • the secondary battery 1000 includes a positive electrode 100, a negative electrode 200, an outer package 500, and an insulating layer 300.
  • the outer package 500 houses the insulating layer 300, the positive electrode 100, and the negative electrode 200.
  • the material of the outer package 500 can be selected from materials that are corrosion resistant to non-aqueous electrolytes, such as aluminum, stainless steel, and nickel-plated steel.
  • the present invention can also be applied to a wound secondary battery.
  • an electrode body 400 composed of a positive electrode 100, an insulating layer 300, and a negative electrode 200 is laminated.
  • the positive electrode 100 or the negative electrode 200 may be referred to as an electrode.
  • the positive electrode 100, the negative electrode 200, or the insulating layer 300 may be referred to as a secondary battery sheet.
  • a structure having an insulating layer 300 and a positive electrode 100 or a negative electrode 200, which has a particularly integrated structure, may be referred to as a battery cell sheet.
  • the positive electrode 100 includes a positive electrode current collector 120 and a positive electrode mixture layer 110.
  • a positive electrode mixture layer 110 is formed on both surfaces of the positive electrode current collector 120.
  • the negative electrode 200 includes a negative electrode current collector 220 and a negative electrode mixture layer 210. Negative electrode mixture layers 210 are formed on both surfaces 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 portion 130.
  • the negative electrode current collector 220 has a negative electrode tab portion 230.
  • the positive electrode tab portion 130 or the negative electrode tab portion 230 may be referred to as an electrode tab portion.
  • An electrode mixture layer is not formed on the electrode tab portion. However, an electrode mixture layer may be formed on the electrode tab portion as long as the performance of the secondary battery 1000 is not adversely affected.
  • the positive electrode tab portion 130 and the negative electrode tab portion 230 protrude to the outside of the outer package 500, and the plurality of protruding positive electrode tab portions 130 and the plurality of negative electrode tab portions 230 are bonded together by, for example, ultrasonic bonding. Thus, a parallel connection is formed in the secondary battery 1000.
  • the present invention can also be applied to a bipolar secondary battery in which an electrical series connection is configured in the secondary battery 1000.
  • the positive electrode mixture layer 110 includes a positive electrode active material, a positive electrode conductive agent, and a positive electrode binder.
  • the negative electrode mixture layer 210 includes 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.
  • Examples of the electrode conductive agent include, but are not limited to, ketjen black, acetylene black, and graphite. These materials may be used alone or in combination.
  • the electrode binder binds an electrode active material or an electrode conductive agent in the electrode.
  • electrode binders include styrene-butadiene rubber, carboxymethyl cellulose, polyvinylidene fluoride (PVDF), and a copolymer of vinylidene fluoride (VDF) and hexafluoropropylene (HFP) (P (VdF-HFP)).
  • PVDF polyvinylidene fluoride
  • HFP hexafluoropropylene
  • VdF-HFP hexafluoropropylene
  • ⁇ Positive electrode active material> In the positive electrode active material exhibiting a noble potential, lithium ions are desorbed 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 containing a transition metal is desirable.
  • part of oxygen in these materials may be substituted with other elements such as fluorine.
  • chalcogenides such as sulfur, TiS 2 , MoS 2 , Mo 6 S 8 , TiSe 2 , vanadium oxides such as V 2 O 5 , halides such as FeF 3 , Fe (MoO 4 ) 3 constituting polyanions, Examples include, but are not limited to, quinone organic crystals such as Fe 2 (SO 4 ) 3 and Li 3 Fe 2 (PO 4 ) 3 .
  • the element ratio may deviate from the above stoichiometric composition.
  • the thickness of the electrode current collector is desirably 15 ⁇ m or less.
  • the thickness of the electrode current collector is larger than 15 ⁇ m, the volume energy density of the secondary battery 1000 may be reduced.
  • the tensile strength of the electrode current collector is increased, and there is a possibility that it is difficult to suppress a short circuit when the nail is inserted into the secondary battery 1000.
  • the tensile strength of the electrode current collector when a nail with a tip angle of 30 ° is used is 16N or less, preferably 14N or less.
  • the tensile strength of the electrode current collector is greater than 16N, the tensile strength of the electrode current collector increases, and when the nail is pierced into the secondary battery 1000, burrs are generated in the electrode current collector. May occur or catch fire.
  • the tensile strength of the electrode current collector is measured by the strength when the electrode current collector is punctured at a speed of 40 mm / sec and the electrode current collector is broken.
  • a nail is used for the piercing jig, the tip angle of the nail can be 30 °, and the diameter of the nail can be 3 mm.
  • the desired thickness of the electrode current collector varies depending on the Young's modulus of the electrode current collector. For example, in aluminum with a Young's modulus of 70 GPa, when the thickness of the electrode current collector is 15 ⁇ m, the cross-sectional area of the portion pierced with a nail with a tip angle of 30 ° is 196 ⁇ m 2 and the tensile strength is 13.7 N. On the other hand, when the thickness of the electrode current collector is 17 ⁇ m, the cross-sectional area of the portion pierced with a nail having a tip angle of 30 ° is 251 ⁇ m 2 and the tensile strength is 17.6 N.
  • the thickness of the electrode current collector is desirably 15 ⁇ m or less.
  • the tensile strength is 39 N when the thickness of the electrode current collector is 15 ⁇ m.
  • the thickness of the electrode current collector is 9 ⁇ m, the cross-sectional area of the portion pierced with a nail having a tip angle of 30 ° is 70 ⁇ m 2 and the tensile strength is 14.1N. Therefore, when a SUS foil having a Young's modulus of 200 GPa is used, the thickness of the electrode current collector is desirably 9 ⁇ m or less.
  • ⁇ Negative electrode active material> In the negative electrode active material exhibiting a base potential, lithium ions are desorbed in the discharging process, and lithium ions desorbed from the positive electrode active material in the positive electrode mixture layer 110 are inserted in the charging process.
  • carbon-based materials graphite, graphitizable carbon materials, amorphous carbon materials, organic crystals, activated carbon, etc.
  • conductive polymer materials polyacene, polyparaphenylene, polyaniline, polyacetylene, etc.
  • lithium composites Oxides lithium titanate: Li 4 Ti 5 O 12 and Li 2 TiO 4 etc.
  • metal lithium metals alloyed with lithium (including at least one kind of aluminum, silicon, tin, etc.) and oxides thereof
  • metal lithium metals alloyed with lithium (including at least one kind of aluminum, silicon, tin, etc.) and oxides thereof
  • Negative electrode current collector 220 examples include, but are not limited to, copper foil, copper perforated foil having a pore diameter of 0.1 to 10 mm, expanded metal, foam metal plate, stainless steel, titanium, nickel, and the like.
  • An electrode mixture layer is prepared by attaching an electrode slurry mixed with 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. Then, in order to remove a solvent, an electrode mixture layer is dried, and an electrode is produced by pressure-molding an electrode mixture layer with a roll press.
  • the content of the non-aqueous electrolyte in the electrode mixture layer is preferably 20 to 40 vol%.
  • the content of the non-aqueous electrolyte is small, the ion conduction path inside the electrode mixture layer is not sufficiently formed, and the rate characteristics may be deteriorated.
  • the content of the non-aqueous electrolyte is large, in addition to the possibility that the non-aqueous electrolyte leaks from the electrode mixture layer, there is a possibility that the electrode active material becomes insufficient and the energy density is lowered. .
  • the nonaqueous electrolyte is injected into the secondary battery 1000 from the vacant side or the injection hole of the outer package 500, and the pores of the electrode mixture layer are filled with the nonaqueous electrolyte. You may let them. This eliminates the need for supported particles contained in the semi-solid electrolyte, and the particles such as electrode active material and electrode conductive agent in the electrode mixture layer function as supported particles, and these particles hold the non-aqueous electrolyte. To do.
  • a slurry in which a non-aqueous electrolyte, an electrode active material, an electrode conductive agent, and an electrode binder are mixed is prepared, and the prepared slurry is collected into an electrode current collector.
  • the thickness of the electrode mixture layer is desirably equal to or greater than the average particle diameter 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 has coarse particles having an average particle size equal to or greater 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 of the electrode mixture layer or less. 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 functions as an electronic insulator and prevents a short circuit between the positive electrode 100 and the negative electrode 200.
  • the insulating layer 300 has a coated separator or a semi-solid electrolyte layer.
  • a coated separator or a semi-solid electrolyte layer may be used in combination.
  • a resin separator may be added to the coated separator or the semi-solid electrolyte layer.
  • a porous sheet can be used as the resin separator.
  • porous sheets cellulose, modified cellulose (carboxymethylcellulose (CMC), hydroxypropylcellulose (HPC), etc.), polyolefin (polypropylene (PP), propylene copolymer, etc.), polyester (polyethylene terephthalate (PET), Polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), etc.), polyacrylonitrile (PAN), polyaramid, polyamideimide, polyimide and other resins, glass and the like, but are not limited thereto. These materials may be used alone or in combination.
  • a separator for forming a separator is formed by applying a separator-forming mixture having separator particles, a separator binder, and a solvent onto a substrate such as an electrode mixture layer. You may apply
  • separator particles include, but are not limited to, oxide inorganic particles in the following supported particles. These materials may be used alone or in combination.
  • the average particle size of the separator particles is desirably 1/100 to 1/2 of the thickness of the separator.
  • separator binder include, but are not limited to, the following semi-solid electrolyte binders. These materials may be used alone or in combination.
  • solvent include, but are not limited to, N-methylpyrrolidone (NMP) and water.
  • the non-aqueous electrolyte is injected into the secondary battery 1000 from the vacant side or the injection hole of the outer package 500 into the secondary battery 1000. Filled.
  • 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.
  • the semi-solid electrolyte has pores formed by aggregates of supported particles, and a non-aqueous electrolyte is held therein. By holding the non-aqueous electrolyte in the semi-solid electrolyte, the semi-solid electrolyte permeates lithium ions.
  • the nonaqueous electrolytic solution may be injected into the secondary battery 1000 from the vacant side or the liquid injection hole of the outer package 500.
  • a method for producing a semi-solid electrolyte layer there are a method of compressing and molding a semi-solid electrolyte powder into a pellet shape with a molding die or the like, and a method of adding and mixing a semi-solid electrolyte binder to a semi-solid electrolyte powder to form a sheet. is there.
  • a semi-solid electrolyte binder powder By adding and mixing a semi-solid electrolyte binder powder to the semi-solid electrolyte, a highly flexible sheet-like semi-solid electrolyte layer can be produced.
  • a semi-solid electrolyte layer may be produced.
  • the supported particles are preferably insulative particles and insoluble in the non-aqueous electrolyte from the viewpoint of electrochemical stability.
  • oxide inorganic particles such as SiO 2 particles, Al 2 O 3 particles, ceria (CeO 2 ) particles, and ZrO 2 particles can be preferably used.
  • a solid electrolyte may be used as the support particles.
  • the solid electrolyte include particles of an inorganic solid electrolyte such as an oxide solid electrolyte such as Li—La—Zr—O and a sulfide solid electrolyte such as Li 10 Ge 2 PS 12 .
  • the average primary particle size of the supported particles is preferably 1 nm to 10 ⁇ m. If the average particle size of the primary particles of the supported particles is large, the supported particles may not properly hold a sufficient amount of the non-aqueous electrolyte, and it may be difficult to form a semi-solid electrolyte. In addition, if the average particle size of the primary particles of the supported particles is small, the inter-surface 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 1 to 50 nm, and further preferably 1 to 10 nm. The average particle size of the primary particles of the supported particles can be measured using TEM.
  • the non-aqueous electrolyte has a non-aqueous solvent.
  • the non-aqueous solvent has an organic solvent, an ionic liquid, or a mixture (complex) of an ether solvent and a solvated electrolyte salt exhibiting properties similar to those of the ionic liquid.
  • An organic solvent, an ionic liquid, or an ether solvent may be referred to as a main solvent. These materials may be used alone or in combination.
  • An ionic liquid is a compound that dissociates into a cation and an anion at room temperature, and maintains a liquid state.
  • the ionic liquid may be referred to as an ionic liquid, a low melting point molten salt or a room temperature molten salt.
  • the non-aqueous solvent is desirably low volatility, specifically, having a vapor pressure of 150 Pa or less at room temperature, from the viewpoint of stability in the air and heat resistance in the secondary battery, but is not limited thereto. Absent.
  • a non-volatile solvent such as an ionic liquid or an ether solvent having properties similar to the ionic liquid for the non-aqueous electrolyte, volatilization of the non-aqueous electrolyte from the semi-solid electrolyte layer can be suppressed.
  • the content of the non-aqueous electrolyte in the semi-solid electrolyte layer is not particularly limited, but is preferably 40 to 90 vol%.
  • the content of the non-aqueous electrolyte is small, the interface resistance between the electrode and the semisolid electrolyte layer may increase.
  • content of a non-aqueous electrolyte is large, a non-aqueous electrolyte may leak from a semi-solid electrolyte layer.
  • the content of the non-aqueous electrolyte in the semi-solid electrolyte layer is preferably 50 to 80 Vol%, more preferably 60 to 80 Vol%.
  • the content of the non-aqueous electrolyte in the semi-solid electrolyte layer is 40-60Vol% is desirable.
  • the weight ratio of the main solvent in the non-aqueous electrolyte is not particularly limited, but the weight ratio of the main solvent in the total amount of the solvent in the non-aqueous electrolyte is 30 to 70 wt%, particularly from the viewpoint of battery stability and fast charge / discharge. It is desirable that the content be 40 to 60 wt%, and further 45 to 55 wt%.
  • Organic solvent As organic solvents, carbonates such as ethylene carbonate (EC), butylene carbonate (BC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (MEC), ⁇ -butyrolactone (GBL) ), Formamide, dimethylformamide, trimethyl phosphate (TMP), triethyl phosphate (TEP), tris (2,2,2-trifluoroethyl) phosphite (TFP), dimethyl methylphosphonate (DMMP), etc. . These materials may be used alone or in combination.
  • EC ethylene carbonate
  • BC butylene carbonate
  • PC propylene carbonate
  • DMC dimethyl carbonate
  • DEC diethyl carbonate
  • MEC methyl ethyl carbonate
  • GBL ⁇ -butyrolactone
  • TMP trimethyl phosphate
  • TMP triethyl phosphate
  • DMMP dimethyl
  • the low-viscosity organic solvent lowers the viscosity of the nonaqueous electrolytic solution and improves the ionic conductivity.
  • the low-viscosity organic solvent is desirably a solvent having a viscosity lower than 140 Pa ⁇ s at 25 ° C.
  • low viscosity organic solvent examples include, but are not limited to, PC, EC, TMP, TEP, TFP, GBL, DMMP and the like. These materials may be used alone or in combination.
  • the ionic liquid is composed of a cation and an anion. Ionic liquids are classified into imidazolium, ammonium, pyrrolidinium, piperidinium, pyridinium, morpholinium, phosphonium, sulfonium, and the like depending on the cation species. Examples of the cation constituting the imidazolium-based ionic liquid include alkyl imidazolium cations such as 1-butyl-3-methylimidazorium (BMI).
  • BMI 1-butyl-3-methylimidazorium
  • Examples of the cation constituting the ammonium-based ionic liquid include, in addition to tetraamylammonium, alkylammonium cations such as N, N, N-trimethyl-N-propylammonium.
  • Examples of the cation constituting the pyrrolidinium-based ionic liquid include alkylpyrrolidinium cations such as N-methyl-N-propylpyrrolidinium (Py13) and 1-butyl-1-methylpyrrolidinium.
  • Examples of the cation constituting the piperidinium-based ionic liquid include alkylpiperidinium cations such as N-methyl-N-propylpiperidinium (PP13) and 1-butyl-1-methylpiperidinium.
  • Examples of the cation constituting the pyridinium-based ionic liquid include alkylpyridinium cations such as 1-butylpyridinium and 1-butyl-4-methylpyridinium.
  • Examples of the cation constituting the morpholinium-based ionic liquid include alkylmorpholinium such as 4-ethyl-4-methylmorpholinium.
  • Examples of the cation constituting the phosphonium-based ionic liquid include alkylphosphonium cations such as tetrabutylphosphonium and tributylmethylphosphonium.
  • Examples of the cation constituting the sulfonium-based ionic liquid include alkylsulfonium cations such as trimethylsulfonium and tributhylsulfonium.
  • anions that are paired with these cations include bis (trifluoromethanesulfonyl) imide (TFSI), bis (fluorosulfonyl) imide, tetrafluoroborate (BF 4 ), hexafluorophosphate (PF 6 ), bis (pentafluoroethanesulfonyl) imide (BETI), and trifluoromethanesulfonate (BETI).
  • Triflate acetate, dimethyl phosphate, dicyanamide, trifluoro (trifluoromethyl) borate and the like. These materials may be used alone or in combination.
  • the non-aqueous electrolyte has an electrolyte salt.
  • the electrolyte salt is preferably one that can be uniformly dispersed in the main solvent.
  • Lithium cation and those consisting of the above anions can be used as lithium salts, such as lithium bis (fluorosulfonyl) imide (LiFSI), lithium bis (trifluoromethanesulfonyl) imide (LiTFSI), lithium bis (pentafluoroethane) Examples include, but are not limited to, sulfonyl) imide (LiBETI), lithium tetrafluoroborate (LiBF 4 ), lithium hexafluorophosphate (LiPF 6 ), and lithium triflate. These materials may be used alone or in combination.
  • the ether solvent constitutes a solvated electrolyte salt and a solvated ionic liquid.
  • a symmetric glycol diglyceride represented by a known glyme (RO (CH 2 CH 2 O) n-R ′ (R and R ′ are saturated hydrocarbons, n is an integer)) showing properties similar to ionic liquids.
  • the generic name of ether can be used.
  • tetraglyme tetraethylene dimethyl glycol, G4
  • triglyme triethylene glycol dimethyl ether, G3
  • pentag lime pentag lime
  • pentag lime pentag lime
  • pentag lime pentag lime
  • pentag lime pentag lime
  • lithium salts such as LiFSI, LiTFSI, LiBETI, LiBF 4 , and LiPF 6 can be used, but are not limited thereto.
  • non-aqueous solvent a mixture of an ether solvent and a solvated electrolyte salt may be used alone or in combination.
  • the non-aqueous electrolyte may have a negative electrode interface stabilizer.
  • the addition amount of the negative electrode interface stabilizer is preferably 30 wt% or less, particularly preferably 10 wt% or less, based on the weight of the non-aqueous electrolyte. If it exceeds 30 wt%, the ion conductivity may be inhibited, or the resistance may increase due to reaction with the electrode.
  • the negative electrode interface stabilizer include vinylene carbonate (VC) and fluoroethylene carbonate (FEC), but are not limited thereto. These materials may be used alone or in combination.
  • the non-aqueous electrolyte may have a corrosion inhibitor.
  • the corrosion inhibitor forms a film in which the metal is difficult to 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 a material containing a cationic species having a strong chemical bond for forming a stable compound in the atmosphere containing moisture is desirable.
  • water solubility and presence / absence of hydrolysis can be mentioned.
  • the solubility in water is desirably less than 1%.
  • the presence or absence of hydrolysis can be evaluated by molecular structure analysis of the sample after mixing with water.
  • no hydrolysis means that the corrosion inhibitor is hygroscopic or mixed with water and then heated at 100 ° C. or higher to remove moisture and 95% of the residue shows the same molecular structure as the additive. Means that.
  • the corrosion inhibitor is represented by (M ⁇ R) + An ⁇ , and the cation of (M ⁇ R) + An ⁇ is (M ⁇ R) +, where M is nitrogen (N), boron (B), phosphorus It consists of either (P) or sulfur (S), and R is composed of a hydrocarbon group.
  • the anion of (M ⁇ R) + An ⁇ is An ⁇ , and BF 4 ⁇ and PF 6 ⁇ are preferably used.
  • corrosion inhibitors examples include tetrabutylammonium hexafluorophosphate (NBu 4 PF 6 ), quaternary ammonium salt of tetrabutylammonium tetrafluoroborate (NBu 4 BF 4 ), 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI-BF 4 ), 1-ethyl-3-methylimidazolium hexafluorophosphate (EMI-PF 6 ), 1-butyl-3-methylimidazolium tetrafluoroborate (BMI-BF 4 ), 1-butyl- Examples include imidazolium salts such as 3-methylimidazolium hexafluorophosphate (BMI-PF 6 ). In particular, if the anion is PF 6 , elution of the positive electrode current collector 120 can be suppressed. These materials may be used alone or in combination.
  • the content of the corrosion inhibitor is 0.5 to 20 wt%, preferably 1 to 10 wt%, based on the total weight of the non-aqueous electrolyte.
  • the content of the corrosion inhibitor is 0.5 to 20 wt%, preferably 1 to 10 wt%, based on the total weight of the non-aqueous electrolyte.
  • the low melting point material means a material having a melting point equal to or lower than the valence reduction temperature of the positive electrode active material.
  • the valence decreasing temperature of the positive electrode active material is a temperature at which the valence of the metal element on the surface of the positive electrode active material particles in the charged state decreases as the temperature increases.
  • the material dissolves below the valence decrease temperature of the positive electrode active material, and the nail penetration into the secondary battery 1000 is performed.
  • the cross section of the positive electrode 100 or the negative electrode 200 appearing in the above can be insulated and protected.
  • the valence reduction temperature of the positive electrode active material is about 170 ° C. Therefore, it is desirable to have a material having a melting point of 170 ° C. or lower, preferably 160 ° C. or lower, more preferably 155 ° C., as a semi-solid electrolyte binder.
  • Low melting point materials include polyethylene (PE), ethylene / vinyl acetate (EVAC), polypropylene (PP), vinyl chloride (PVC), polystyrene (PA), acrylonitrile / styrene (AS), acrylonitrile / butadiene / styrene (ABS), Examples include methacrylic resin (PMMA), polyvinyl alcohol (PVA), polycarbonate (PC), acetal resin (PCM), SBR, and P (VdF-HFP). These materials may be used alone or in combination. By using 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 material such as PVDF having a melting point higher than the valence reduction temperature of the positive electrode active material may be included.
  • the addition amount of the low melting point material in the insulating layer 300 is desirably 4 to 15 wt%. If the addition amount of the low melting point material is small, it may be difficult to ensure the insulation of the cross section of the positive electrode 100 or the negative electrode 200. If the amount of the low-melting-point material added is large, the number of supported particles that hold the non-aqueous electrolyte is reduced, the non-aqueous electrolyte is not sufficient, and the resistance of the secondary battery 1000 may be increased.
  • the measuring method of the addition amount of the low melting point material is as follows.
  • the secondary battery 1000 is disassembled, the nonaqueous electrolyte in the secondary battery 1000 is removed by washing with methanol, the electrode is dried, and then only the semi-solid electrolyte is scraped out and the weight is measured. Thereafter, the semi-solid electrolyte is immersed in NMP, the supernatant is subjected to NMR analysis after centrifugation, and the amount of the low-melting-point material added is calculated from the peak ratios derived from various low-melting-point binders.
  • a semi-solid electrolyte is formed by supporting or holding the non-aqueous electrolyte on the support particles.
  • a method for producing a semi-solid electrolyte a non-aqueous electrolyte and supported particles are mixed at a specific volume ratio, and an organic solvent such as methanol is added and mixed to prepare a semi-solid electrolyte slurry. It is spread on a petri dish and the organic solvent is distilled off to obtain a semi-solid electrolyte powder.
  • FIG. 2 shows a change in the insulating layer 300 due to the nail penetration into the secondary battery 1000.
  • 2A to 2D are partial cross-sectional views of the secondary battery.
  • FIG. 2A shows the state of the secondary battery 1000 before the nail 2000 is inserted.
  • the positive electrode 100 and the negative electrode 200 become conductive through the nail 2000, and the positive electrode 100 and the negative electrode 200 are short-circuited.
  • the voltage of the secondary battery 1000 decreases.
  • the binder component in the insulating layer 300 is melted by the heat generated by the short circuit between the positive electrode 100 and the negative electrode 200. As shown in FIG.
  • the molten insulating layer 300 is formed on the side surface of the electrode and the periphery of the nail 2000, so that the nail 2000 and the electrode are substantially insulated.
  • the insulating layer 300 is formed between the nail 2000 and the electrode in the in-plane direction of the battery cell sheet. Thereby, a short circuit between the positive electrode 100 and the negative electrode 200 is suppressed.
  • the voltage of the secondary battery 1000 becomes substantially equal to the voltage before the nail 2000 is inserted.
  • the molten insulating layer 300 is formed on the side surface of the electrode as shown in FIG. 2 (d).
  • the insulating layer 300 is formed on the side surface in the in-plane direction of the electrode.
  • a short circuit occurs between the positive electrode 100 and the negative electrode 200, and the voltage of the secondary battery 1000 gradually decreases to an extent that does not impair safety. Thereby, the safety of the secondary battery 1000 can be improved.
  • the voltage drop of the secondary battery 1000 immediately after the nail 2000 is inserted into the secondary battery 1000 from the electrode stacking direction is 0.01 to 0.07 V, preferably 0.02 to 0.07 V.
  • the voltage of the secondary battery 1000 recovered after the molten insulating layer 300 is formed on the side surface of the electrode is preferably 50% or more of the voltage of the secondary battery 1000 before the nail 2000 is inserted.
  • the difference between the voltage of the secondary battery 1000 before piercing the nail 2000 and the voltage of the secondary battery 1000 after 30 seconds of piercing the nail 2000 is 0.04 V or less, Preferably it is 0.03V or less, more preferably 0.02V or less.
  • NMP N-methyl-2-pyrrolidone
  • the positive electrode 100 was produced by coating. The coating amount was 30.1 mg / cm 2 on both sides. The density was adjusted with a roll press, and the electrode density was 3.15 g / cm 3 .
  • Graphite as the negative electrode active material and styrene-butadiene rubber (SBR) and carboxymethyl cellulose (CMC) as the negative electrode binder were uniformly mixed at a ratio of 98: 1: 1 using a kneader. Water was added to this mixture and adjusted to a predetermined solid content ratio, and then coated on a Cu negative electrode current collector 220 with a desktop coater through a drying furnace at 100 ° C. to prepare a negative electrode 200. The coating amount was 18.1 mg / cm 2 on both sides. The density was adjusted with a roll press, and the electrode density was 1.55 g / cm 3 .
  • Uniform mixing was performed using a kneader so that the ratio of 1 ⁇ m of SiO 2 as the separator particles and P (VdF-HFP) as the separator binder was 89.3: 10.7.
  • This mixture was slurried with NMP and adjusted to a predetermined solid content ratio. Thereafter, the slurry was applied to both surfaces of the electrode through a drying oven at 100 ° C. using a tabletop coater to produce an insulating layer 300 as a coating separator.
  • the electrode was punched with an air punching machine so that the positive electrode mixture layer 110 had a size of 178 ⁇ 178 mm and the negative electrode mixture layer 210 had a size of 182 ⁇ 183 mm, thereby producing an electrode tab portion.
  • the electrode was dried at 100 ° C. for 2 h to remove NMP in the electrode.
  • the positive electrode 100 was sandwiched between resin separators having a thickness of 30 ⁇ m and a three-layer structure of PP / PE / PP, and three sides other than the side where the positive electrode tab portion 130 was formed were thermally welded.
  • Electrode body 400 After a predetermined number of positive electrodes 100 and negative electrodes 200 were alternately laminated (electrode body 400), a 50 ⁇ m thick polytetrafluoroethylene sheet was placed on the outermost negative electrode 200.
  • the electrode tab portions formed at the end portions of the electrodes were bundled, and the bundled electrode tab portions, the positive electrode terminal made of Al, and the negative electrode terminal made of Ni were each welded with ultrasonic waves.
  • the electrode body 400 is sandwiched between laminate films, leaving one side for injection, and 3 sides including the side where the electrode tab part is formed are heat sealed at 200 ° C with a laminate sealing device, and vacuumed at 60 ° C for 20 hours Dried.
  • the electrolyte solution was injected from one side for injection, and one side for injection was vacuum sealed.
  • the electrolytic solution is obtained by adding 1 wt% of VC (vinylene carbonate) to 1 M LiPF 6 , EC (ethylene carbonate), and EMC (ethyl methyl carbonate). The volume ratio of EC and EMC was 1: 2.
  • the manufactured laminate type secondary battery 1000 was charged at a constant current of 25 ° C., a voltage of 4.2 V, and a current of 0.05 CA, and then charged at a constant voltage for 20 hours.
  • the secondary battery 1000 was discharged at a constant current of 2.7 V and a current of 0.05 CA, charged again at a constant current of a voltage of 4.2 V and a current of 0.05 CA, and then charged at a constant voltage for 20 hours.
  • the secondary battery 1000 is secured using a lashing jig with an open center, and the center of the secondary battery 1000 is nipped and the nail 2000 is inserted until the secondary battery 1000 penetrates at a speed of 40 mm / sec. Hold for 1 minute.
  • a nail 2000 having a tip angle of 30 ° and a nail diameter of 3 mm was used.
  • the voltage of the secondary battery 1000 was measured while the nail 2000 was pierced. The presence or absence of white smoke from the laminate-type secondary battery 1000 in the nail penetration test was confirmed visually.
  • thermocouple built in the tip of the nail 2000 and a thermocouple attached to the surface of the secondary battery 1000.
  • Examples 2 to 4 The same procedure as in Example 1 was performed except that the nonaqueous electrolyte solution was changed as shown in FIG.
  • the temperature of the secondary battery 1000 in Examples 1 and 2 increased only to 40 ° C. at the maximum, the insulating layer 300 melted from the observation of the cross-sectional structure after the nail penetration test, and the positive electrode 100 and the negative electrode 200 It was confirmed that the side surface was covered with the insulating layer 300. This is because the inrush current that flowed at the time of voltage drop immediately after nail penetration realized a high temperature of 150 ° C locally between the nail 2000 and the electrode body 400, melting the insulating layer 300 and preventing a short circuit. It is done.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Secondary Cells (AREA)
  • Cell Electrode Carriers And Collectors (AREA)
  • Cell Separators (AREA)
  • Connection Of Batteries Or Terminals (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

L'invention aborde le problème de la fourniture d'une feuille cellulaire pour rendre une cellule plus sûre, et une cellule la comprenant. Pour résoudre le problème, l'invention concerne une feuille cellulaire comprenant une électrode et une couche d'isolation formée sur les électrodes, un clou ayant une extrémité de bout angulaire à 30° étant percé sur la feuille cellulaire, la couche d'isolation est formée entre le clou et l'électrode dans une direction dans le plan de la feuille cellulaire, et après que le clou est retiré, la couche d'isolation est formée sur la surface latérale de l'électrode dans une direction dans le plan de la feuille cellulaire. L'invention concerne en outre une cellule comprenant ladite feuille cellulaire.
PCT/JP2019/005260 2018-05-24 2019-02-14 Feuille cellulaire et cellule WO2019225077A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2018-099288 2018-05-24
JP2018099288A JP2019204690A (ja) 2018-05-24 2018-05-24 電池セルシート、電池

Publications (1)

Publication Number Publication Date
WO2019225077A1 true WO2019225077A1 (fr) 2019-11-28

Family

ID=68616895

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2019/005260 WO2019225077A1 (fr) 2018-05-24 2019-02-14 Feuille cellulaire et cellule

Country Status (2)

Country Link
JP (1) JP2019204690A (fr)
WO (1) WO2019225077A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003077545A (ja) * 2001-06-18 2003-03-14 Japan Storage Battery Co Ltd 非水電解質電池の製造方法
WO2014168019A1 (fr) * 2013-04-12 2014-10-16 株式会社村田製作所 Batterie secondaire au lithium-ion
WO2015053177A1 (fr) * 2013-10-11 2015-04-16 株式会社村田製作所 Batterie à électrolyte non aqueux et procédé permettant de produire cette dernière
JP2017033839A (ja) * 2015-08-04 2017-02-09 日立化成株式会社 リチウム二次電池用正極、リチウム二次電池及びリチウムイオン二次電池用正極の製造方法
JP2018073665A (ja) * 2016-10-31 2018-05-10 トヨタ自動車株式会社 硫化物全固体電池

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003077545A (ja) * 2001-06-18 2003-03-14 Japan Storage Battery Co Ltd 非水電解質電池の製造方法
WO2014168019A1 (fr) * 2013-04-12 2014-10-16 株式会社村田製作所 Batterie secondaire au lithium-ion
WO2015053177A1 (fr) * 2013-10-11 2015-04-16 株式会社村田製作所 Batterie à électrolyte non aqueux et procédé permettant de produire cette dernière
JP2017033839A (ja) * 2015-08-04 2017-02-09 日立化成株式会社 リチウム二次電池用正極、リチウム二次電池及びリチウムイオン二次電池用正極の製造方法
JP2018073665A (ja) * 2016-10-31 2018-05-10 トヨタ自動車株式会社 硫化物全固体電池

Also Published As

Publication number Publication date
JP2019204690A (ja) 2019-11-28

Similar Documents

Publication Publication Date Title
US20100092869A1 (en) Lithium ion battery
KR102232148B1 (ko) 반고체 전해질층, 전지셀 시트 및 이차전지
KR20080033855A (ko) 전지
WO2019234977A1 (fr) Couche d'électrolyte semi-solide et batterie secondaire
JP2014127242A (ja) リチウム二次電池
WO2019176174A1 (fr) Bouillie d'électrode positive, électrode positive, feuille de cellule, batterie secondaire
JPWO2019021522A1 (ja) 半固体電解液、半固体電解質、半固体電解質層および二次電池
CN110521049B (zh) 半固体电解质、电极、带有半固体电解质层的电极和二次电池
JP2020004598A (ja) 電池
WO2019225078A1 (fr) Couche d'isolation, feuille de cellule de batterie et batterie secondaire
JP2010027549A (ja) 電気化学素子用セパレータ、およびそれを用いたリチウムイオン電池
JP2020202158A (ja) 絶縁層、電池セル用シート及び電池セル
WO2019225077A1 (fr) Feuille cellulaire et cellule
CN110506357B (zh) 半二次电池和二次电池
JP2015125950A (ja) リチウムイオン二次電池
JP7553044B2 (ja) 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
WO2020003864A1 (fr) Électrode négative, feuille d'élément de batterie, et accumulateur
WO2019142502A1 (fr) Électrode négative, demi-pile rechargeable et pile rechargeable
WO2020213268A1 (fr) Solution électrolytique non aqueuse, électrolyte non volatil et batterie secondaire
CN112106161B (zh) 碱金属离子电容器
JP2010027548A (ja) 電気化学素子用セパレータ、およびそれを用いたリチウムイオン電池
WO2019087815A1 (fr) Couche de mélange d'électrodes positives, électrode positive, batterie semi-secondaire et batterie secondaire
WO2019198329A1 (fr) Couche d'isolation, feuille de cellule de batterie et batterie
JP2020087640A (ja) 電池セルの診断方法

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: 19806883

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: 19806883

Country of ref document: EP

Kind code of ref document: A1