WO2023234093A1 - 非水電解質二次電池 - Google Patents

非水電解質二次電池 Download PDF

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Publication number
WO2023234093A1
WO2023234093A1 PCT/JP2023/018899 JP2023018899W WO2023234093A1 WO 2023234093 A1 WO2023234093 A1 WO 2023234093A1 JP 2023018899 W JP2023018899 W JP 2023018899W WO 2023234093 A1 WO2023234093 A1 WO 2023234093A1
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Prior art keywords
secondary battery
resin particles
layer
positive electrode
electrode
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Ceased
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PCT/JP2023/018899
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English (en)
French (fr)
Japanese (ja)
Inventor
創太 福田
真治 笠松
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Panasonic Energy Co Ltd
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Panasonic Energy Co Ltd
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Priority to US18/866,644 priority Critical patent/US20250309470A1/en
Priority to JP2024524351A priority patent/JPWO2023234093A1/ja
Priority to CN202380041453.6A priority patent/CN119156738A/zh
Publication of WO2023234093A1 publication Critical patent/WO2023234093A1/ja
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • 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
    • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
    • H01M50/451—Separators, membranes or diaphragms characterised by the material having a layered structure comprising layers of only organic material and layers containing inorganic material
    • 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
    • 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
    • H01M50/431—Inorganic material
    • H01M50/434—Ceramics
    • 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
    • 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
    • H01M50/446—Composite material consisting of a mixture of organic and inorganic materials
    • 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
    • H01M50/46—Separators, membranes or diaphragms characterised by their combination with electrodes
    • 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
    • H01M50/46—Separators, membranes or diaphragms characterised by their combination with electrodes
    • H01M50/461—Separators, membranes or diaphragms characterised by their combination with electrodes with adhesive layers between electrodes and separators
    • 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
    • H01M50/463—Separators, membranes or diaphragms characterised by their shape
    • 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
    • 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 disclosure relates to a non-aqueous electrolyte secondary battery.
  • non-aqueous electrolyte secondary batteries have been widely used as high-output, high-energy-density secondary batteries.
  • charging and discharging are performed by moving lithium ions and the like between a pair of electrode plates (a positive electrode and a negative electrode) via an electrolyte.
  • the positive electrode and the negative electrode face each other with a separator in between, and the separator isolates the positive electrode and the negative electrode from each other.
  • the separator may have a filler layer on the surface of a base layer made of porous polyolefin or the like for the purpose of improving heat resistance.
  • Patent Document 1 discloses a technique in which a filler layer facing a negative electrode contains two polymers with different particle sizes in a pouch-type secondary battery to make the surface of the filler layer non-uniform.
  • a pouch-type secondary battery is flexible and may be deformed due to expansion and contraction of the electrode body during charging and discharging.
  • Patent Document 1 states that by making the surface of the filler layer uneven, voids are created, and by absorbing the expansion of the negative electrode during charging, the increase in the thickness of the electrode body can be suppressed. .
  • An object of the present disclosure is to provide a non-aqueous electrolyte secondary battery with improved liquid permeability while suppressing electrode plate deformation.
  • a non-aqueous electrolyte secondary battery that is an embodiment of the present disclosure includes an electrode body in which a positive electrode and a negative electrode are wound with a separator interposed therebetween, an electrolytic solution, and an outer can housing the electrode body and the electrolytic solution.
  • the part is a resin that protrudes from the inorganic particle layer formed by inorganic particles excluding the convex portions of the filler layer, and forms convex portions in an area of 100 ⁇ m x 100 ⁇ m when the surface of the filler layer is observed with a scanning electron microscope. It is characterized in that 10 to 35 particles are detected.
  • liquid permeability can be improved while suppressing electrode plate deformation. Thereby, the safety and productivity of the non-aqueous electrolyte secondary battery can be improved.
  • FIG. 1 is a longitudinal cross-sectional view of a cylindrical secondary battery that is an example of an embodiment.
  • FIG. 2 is a cross-sectional view of a separator that is an example of an embodiment.
  • FIG. 3 is a diagram for explaining a method for evaluating deformation of an electrode plate.
  • a cylindrical secondary battery in which an electrode body is housed in a cylindrical outer can will be exemplified, but the outer can is not limited to a cylindrical shape, and may be square, coin-shaped, etc., for example.
  • specific shapes, materials, numerical values, directions, etc. are illustrative to facilitate understanding of the present disclosure, and may be changed as appropriate according to the specifications of the non-aqueous electrolyte secondary battery. I can do it.
  • FIG. 1 is a longitudinal cross-sectional view of a cylindrical secondary battery 10 that is an example of an embodiment.
  • an electrode body 14 and an electrolyte (not shown) are housed in an outer can 15.
  • the direction along the axial direction of the outer can 15 will be referred to as the "vertical direction or vertical direction”
  • the sealing body 16 side will be referred to as "upper”
  • the bottom side of the outer can 15 will be referred to as "lower”. do.
  • non-aqueous solvent (organic solvent) for the electrolytic solution carbonates, lactones, ethers, ketones, esters, etc. can be used, and two or more of these solvents can be used as a mixture.
  • a mixed solvent containing a cyclic carbonate and a chain carbonate For example, ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), etc. can be used as the cyclic carbonate, and dimethyl carbonate (DMC), ethylmethyl carbonate (EMC), and diethyl carbonate ( DEC) etc. can be used.
  • the ester it is preferable to use carbonate esters such as methyl acetate (MA) and methyl propionate (MP).
  • the non-aqueous solvent may contain a halogen-substituted product in which at least some of the hydrogen atoms of these solvents are replaced with halogen atoms such as fluorine.
  • halogen substituted substance it is preferable to use, for example, fluoroethylene carbonate (FEC), methyl fluoropropionate (FMP), and the like.
  • LiPF 6 LiBF 4 , LiCF 3 SO 3 , lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, etc., and mixtures thereof can be used.
  • the amount of electrolyte salt dissolved in the nonaqueous solvent is, for example, 0.5 mol/liter to 2.0 mol/liter.
  • the electrode body 14 has a wound structure in which a strip-shaped positive electrode 11 and a strip-shaped negative electrode 12 are wound with a separator 13 in between.
  • the positive electrode 11, the negative electrode 12, and the separator 13 are all strip-shaped elongated bodies, and are spirally wound so as to be alternately stacked in the radial direction of the electrode body 14.
  • the positive electrode 11, the negative electrode 12, and the separator 13 are wound, for example, 10 to 30 times.
  • the negative electrode 12 is formed to be one size larger than the positive electrode 11 in order to prevent precipitation of lithium. That is, the negative electrode 12 is formed longer than the positive electrode 11 in the longitudinal direction and the width direction (short direction).
  • the separators 13 are formed to be one size larger than the positive electrode 11 and the negative electrode 12, and two separators 13 are arranged so as to sandwich the positive electrode 11 therebetween.
  • a positive electrode lead 19 is connected to the approximately center of the positive electrode 11 in the longitudinal direction by welding or the like, and a negative electrode lead 20 is connected to the inner end of the negative electrode 12 by welding or the like.
  • Insulating plates 17 and 18 are arranged above and below the electrode body 14, respectively.
  • the positive electrode lead 19 extends toward the sealing body 16 through the through hole of the insulating plate 17, and is connected to the lower surface of the filter 22 of the sealing body 16 by welding or the like.
  • the cap 26, which is the top plate of the sealing body 16 electrically connected to the filter 22 serves as a positive terminal.
  • the negative electrode lead 20 extends to the bottom side of the outer can 15 through the through hole of the insulating plate 18, and is connected to the bottom inner surface of the outer can 15 by welding or the like.
  • the outer can 15 serves as a negative terminal. Note that when the negative electrode lead 20 is installed at the outer end of the winding, the negative electrode lead 20 passes through the outside of the insulating plate 18, extends to the bottom side of the outer can 15, and is welded to the bottom inner surface of the outer can 15. .
  • the outer can 15 is a cylindrical metal container with a bottom that is open on one axial side.
  • a gasket 27 is provided between the outer can 15 and the sealing body 16 to ensure hermeticity inside the battery and insulation between the outer can 15 and the sealing body 16.
  • the outer can 15 is formed with a grooved part 21 that supports the sealing body 16 and has a part of the side surface protruding inward.
  • the grooved portion 21 is preferably formed in an annular shape along the circumferential direction of the outer can 15, and supports the sealing body 16 on its upper surface.
  • the sealing body 16 is fixed to the upper part of the outer can 15 by the grooved part 21 and the open end of the outer can 15 which is crimped to the sealing body 16 .
  • the sealing body 16 has a structure in which a filter 22, a lower valve body 23, an insulating member 24, an upper valve body 25, and a cap 26 are stacked in order from the electrode body 14 side.
  • Each member constituting the sealing body 16 has, for example, a disk shape or a ring shape, and each member except the insulating member 24 is electrically connected to each other.
  • the lower valve body 23 and the upper valve body 25 are connected at their respective central portions, and an insulating member 24 is interposed between their respective peripheral portions.
  • the positive electrode 11, negative electrode 12, and separator 13 that constitute the electrode body 14 will be described in detail, particularly the separator 13.
  • the positive electrode 11 includes a positive electrode current collector and a positive electrode mixture layer formed on the surface of the positive electrode current collector.
  • a positive electrode current collector a metal foil such as aluminum that is stable in the positive electrode potential range, a film having the metal disposed on the surface layer, or the like can be used.
  • the thickness of the positive electrode current collector is, for example, 10 ⁇ m to 30 ⁇ m.
  • the positive electrode mixture layer is preferably formed on both sides of the positive electrode current collector.
  • the thickness of the positive electrode mixture layer is, for example, 10 ⁇ m to 150 ⁇ m on one side of the positive electrode current collector.
  • the positive electrode mixture layer includes, for example, a positive electrode active material, a conductive agent, and a binder.
  • a positive electrode mixture slurry containing a positive electrode active material, a conductive agent, a binder, etc. is applied to both sides of a positive electrode current collector, the coating film is dried, and then the coating film is rolled using a roller or the like. It can be made by doing this.
  • Examples of the positive electrode active material contained in the positive electrode mixture layer include lithium transition metal composite oxides containing transition metal elements such as Co, Mn, and Ni.
  • Examples of lithium transition metal composite oxides include Li x CoO 2 , Li x NiO 2 , Li x MnO 2 , Li x Co y Ni 1-y O 2 , Li x Co y M 1-y O z , Li x Ni 1 -y M y O z , Li x Mn 2 O 4 , Li x Mn 2-y M y O 4 , LiMPO 4 , Li 2 MPO 4 F (M is Na, Mg, Sc, Y, Mn, Fe, Co , Ni, Cu, Zn, Al, Cr, Pb, Sb, and B, 0 ⁇ x ⁇ 1.2, 0 ⁇ y ⁇ 0.9, 2.0 ⁇ z ⁇ 2.3). . These may be used alone or in combination.
  • the positive electrode active material preferably contains a lithium-nickel composite oxide, since it is possible to increase the capacity of the non-aqueous electrolyte secondary battery.
  • Lithium-nickel composite oxides include Li x NiO 2 , Li x Co y Ni 1-y O 2 , Li x Ni 1-y M y O z (M is Na, Mg, Sc, Y, Mn, Fe, Co , Ni, Cu, Zn, Al, Cr, Pb, Sb, at least one of B, 0 ⁇ x ⁇ 1.2, 0 ⁇ y ⁇ 0.9, 2.0 ⁇ z ⁇ 2.3), etc. I can give an example. The higher the Ni content of the lithium-nickel composite oxide, the higher the capacity.
  • Examples of the conductive agent contained in the positive electrode mixture layer include carbon-based particles such as carbon black (CB), acetylene black (AB), Ketjen black, carbon nanotubes (CNT), graphene, and graphite. These may be used alone or in combination of two or more.
  • binder contained in the positive electrode mixture layer examples include fluororesins such as polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polyimide resins, acrylic resins, and polyolefins. Examples include resins. These may be used alone or in combination of two or more.
  • the negative electrode 12 includes a negative electrode current collector and a negative electrode mixture layer formed on the surface of the negative electrode current collector.
  • a foil of a metal such as copper that is stable in the potential range of the negative electrode, a film with the metal disposed on the surface layer, or the like can be used.
  • the thickness of the negative electrode current collector is, for example, 5 ⁇ m to 30 ⁇ m.
  • the negative electrode mixture layer is preferably formed on both sides of the negative electrode current collector.
  • the thickness of the negative electrode mixture layer is, for example, 10 ⁇ m to 150 ⁇ m on one side of the negative electrode current collector.
  • the negative electrode mixture layer includes, for example, a negative electrode active material and a binder.
  • the negative electrode is produced by, for example, applying a negative electrode mixture slurry containing a negative electrode active material, a binder, etc. to both sides of a negative electrode current collector, drying the coating film, and then rolling the coating film using a roller or the like. It can be made.
  • the negative electrode active material contained in the negative electrode mixture layer is not particularly limited as long as it can reversibly insert and release lithium ions, and carbon materials such as graphite are generally used.
  • the graphite may be natural graphite such as flaky graphite, lumpy graphite, or earthy graphite, or artificial graphite such as lumpy artificial graphite or graphitized mesophase carbon microbeads.
  • metals that alloy with Li such as Si and Sn, metal compounds containing Si and Sn, lithium titanium composite oxides, and the like may be used.
  • fine particles of Si may be present in a Si-containing compound represented by SiO x (0.5 ⁇ x ⁇ 1.6) or in a lithium silicate phase represented by Li 2y SiO (2+y) (0 ⁇ y ⁇ 2).
  • a dispersed Si-containing compound or the like may be used in combination with graphite.
  • the Si-containing compound expands and contracts at a high rate during charging and discharging of the battery, when the negative electrode 12 contains the Si-containing compound, the electrode plate is likely to be deformed. Therefore, when the negative electrode 12 contains a Si-containing compound, the effect of the separator 13 described later is significant.
  • binder contained in the negative electrode mixture layer examples include styrene-butadiene rubber (SBR), nitrile-butadiene rubber (NBR), carboxymethyl cellulose (CMC) or its salt, polyacrylic acid (PAA) or its salt (PAA), etc. -Na, PAA-K, etc. (may also be partially neutralized salts), polyvinyl alcohol (PVA), and the like. These may be used alone or in combination of two or more.
  • FIG. 2 is a cross-sectional view of the separator 13, which is an example of an embodiment.
  • the positive electrode 11 is placed on the upper side of the separator 13, and the negative electrode 12 is placed on the lower side.
  • the separator 13 includes a base layer 13a and a filler layer 13b formed on at least one surface of the base layer 13a.
  • the filler layer 13b faces the positive electrode 11
  • the base material layer 13a faces the negative electrode 12.
  • the present invention is not limited to this example, and the filler layer 13b may face the negative electrode 12, and the base material layer 13a may face the positive electrode 11.
  • the separator 13 may have filler layers 13b on both sides of the base layer 13a.
  • the base material layer 13a for example, a porous sheet having ion permeability and insulation properties is used. Specific examples of porous sheets include microporous thin films, woven fabrics, and nonwoven fabrics.
  • the material of the base layer 13a is not particularly limited, but may include polyolefin such as polyethylene, polypropylene, a copolymer of polyethylene and ⁇ -olefin, acrylic resin, polystyrene, polyester, cellulose, polyimide, polyphenylene sulfide, polyether ether ketone, and fluorine. Examples include resin.
  • the base material layer 13a may have a single layer structure or a multilayer structure. The thickness of the base material layer 13a is preferably 3 ⁇ m to 20 ⁇ m, more preferably 5 ⁇ m to 15 ⁇ m.
  • the filler layer 13b includes inorganic particles 30 and resin particles 32 having a larger average particle diameter than the inorganic particles 30. Further, the filler layer 13b has a convex portion 32a formed of resin particles 32, and the convex portion 32a protrudes from an inorganic particle layer 34 made of inorganic particles 30 in the filler layer 13b.
  • the inorganic particle layer 34 is a layer formed by aggregation of the inorganic particles 30, and is formed in a region of the filler layer 13b excluding the convex portions 32a. In FIG.
  • the inorganic particles 30 are stacked in approximately two stages in the thickness direction of the separator 13, but the invention is not limited to this example, and the inorganic particles 30 may be stacked in only one stage in the thickness direction of the separator 13. Alternatively, they may be stacked in two or more stages.
  • the particle diameter d of the resin particles 32 in the thickness direction of the separator 13 is larger than the thickness t of the inorganic particle layer 34.
  • the upper portions of the resin particles 32 forming the convex portions 32a protrude from the inorganic particle layer 34.
  • the resin particles 32 may be in contact with the base material layer 13a.
  • the cross section of the resin particles 32 may be circular or elliptical.
  • the average particle diameter (D50) of the resin particles 32 is preferably 1 ⁇ m to 10 ⁇ m larger than the thickness t of the inorganic particle layer 34. If the difference between D50 of the resin particles 32 and the thickness t of the inorganic particle layer 34 is within this range, the effect of suppressing electrode plate deformation and the effect of improving liquid permeability by the separator 13 will be more significant.
  • the D50 of the inorganic particles 30 is, for example, 0.3 ⁇ m to 0.8 ⁇ m.
  • the average particle size (D50) refers to the particle size at which the cumulative frequency is 50% from the smallest particle size in the volume-based particle size distribution, and is also referred to as the median particle size.
  • the particle size distribution of the inorganic particles can be measured using a laser diffraction type particle size distribution measuring device (for example, MT3000II manufactured by Microtrac Bell Co., Ltd.) using water as a dispersion medium.
  • the surface of the filler layer 13b is observed with a scanning electron microscope (SEM, for example SU8220 manufactured by Hitachi High-Tech Corporation), 10 to 35 resin particles 32 forming the convex portions 32a are detected in an area of 100 ⁇ m x 100 ⁇ m. Ru.
  • SEM scanning electron microscope
  • the deformation of the electrode plate means that at least one of the pair of electrode plates (the positive electrode 11 and the negative electrode 12) is bent.
  • the number of detected resin particles forming the convex portions 32a is less than 10, the effect of suppressing electrode plate deformation will not be sufficiently exerted. Furthermore, if the number of resin particles 32 forming the detected convex portions 32a is greater than 35, the liquid permeability will not be sufficiently improved.
  • the convex portion 32a may have a size that can be detected by SEM observation performed by magnifying the surface of the filler layer 13b 1000 times, for example. A 100 ⁇ m ⁇ 100 ⁇ m area on the surface of the filler layer 13b is observed, and the number of resin particles 32 forming the convex portions 32a is counted. Observations are made for three different regions, and the average value of the number detected in each region is taken as the number of resin particles 32 per predetermined area (100 ⁇ m ⁇ 100 ⁇ m) forming the convex portion 32a.
  • Examples of the material of the resin particles 32 include acrylic resins made of ethylenically unsaturated carboxylic acid alkyl esters such as methyl acrylate, butyl acrylate, ethyl acrylate, and 2-ethylhexyl acrylate, and cyano group such as acrylonitrile.
  • Examples include resins containing ethylenically unsaturated monomers, resins containing ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and maleic acid, and salts thereof.
  • the resin particles 32 have adhesive properties with the positive electrode 11, and in the secondary battery 10, the resin particles 32 are preferably adhered to the positive electrode.
  • the effect of suppressing the internal stress of the electrode body 14 becomes more pronounced when the electrode body 14 expands due to charging and discharging.
  • the resin particles 32 exhibit adhesiveness to the positive electrode 11 when holding an electrolyte.
  • Examples of the inorganic particles 30 include metal oxide particles, metal nitride particles, metal fluoride particles, metal carbide particles, and the like.
  • metal oxide particles include aluminum oxide, titanium oxide, magnesium oxide, zirconium oxide, nickel oxide, silicon oxide, manganese oxide, and the like.
  • Examples of the metal nitride particles include titanium nitride, boron nitride, aluminum nitride, magnesium nitride, and silicon nitride.
  • Examples of metal fluoride particles include aluminum fluoride, lithium fluoride, sodium fluoride, magnesium fluoride, calcium fluoride, barium fluoride, and the like.
  • metal carbide particles include silicon carbide, boron carbide, titanium carbide, and tungsten carbide.
  • the inorganic particles 30 are porous particles such as zeolite ( M2/ nO.Al2O3.xSiO2.yH2O , M is a metal element, n is the valence of M, x ⁇ 2, y ⁇ 0) . It may also be a layered silicate such as aluminosilicate, talc (Mg 3 Si 4 O 10 (OH) 2 ), minerals such as barium titanate (BaTiO 3 ), strontium titanate (SrTiO 3 ), or the like. These may be used alone or in combination of two or more.
  • the filler layer 13b may further contain a binder.
  • the binder has the function of bonding the inorganic particles 30 and resin particles 32 as fillers to each other and to bonding the fillers and the base material layer.
  • the binder is preferably a polymeric material, such as fluorine resins such as polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE), polyimide resins, polyamide resins, acrylic resins, polyolefin resins, and styrene.
  • SBR -butadiene rubber
  • NBR nitrile-butadiene rubber
  • CMC carboxymethylcellulose
  • PAA polyacrylic acid
  • PVA polyvinyl alcohol
  • the content of the inorganic particles 30 when the content of the inorganic particles 30 is 100 parts by mass, the content of the resin particles 32 is, for example, 1 part by mass to 10 parts by mass, and the content of the binder is, for example, 1 part by mass. parts to 10 parts by mass.
  • Example> [Preparation of positive electrode]
  • the positive electrode active material aluminum-containing lithium nickel cobalt oxide represented by LiNi 0.88 Co 0.09 Al 0.03 O 2 was used. 100 parts by mass of positive electrode active material, 1 part by mass of acetylene black (AB), and 0.9 parts by mass of polyvinylidene fluoride (PVDF) were mixed, and an appropriate amount of N-methyl-2-pyrrolidone (NMP) was added. A positive electrode mixture slurry was prepared. Next, the positive electrode mixture slurry is applied to both sides of a strip-shaped positive electrode current collector made of aluminum foil with a thickness of 15 ⁇ m, dried, rolled, and cut into a predetermined plate size.
  • NMP N-methyl-2-pyrrolidone
  • a positive electrode in which a positive electrode mixture layer was formed was produced.
  • An exposed positive electrode part in which the mixture layer was not present and the surface of the current collector was exposed was provided approximately at the center in the longitudinal direction of the positive electrode, and an aluminum positive electrode lead was welded to the exposed positive electrode part.
  • [Preparation of negative electrode] 95 parts by mass of graphite, 5 parts by mass of Si oxide (SiO), 1 part by mass of sodium carboxymethylcellulose (CMC-Na), and 1 part by mass of styrene-butadiene rubber (SBR) were mixed, and water was added. An appropriate amount was added to prepare a negative electrode mixture slurry. Next, the negative electrode mixture slurry is applied to both sides of a strip-shaped negative electrode current collector made of copper foil with a thickness of 8 ⁇ m, dried, rolled, and cut into a predetermined plate size. A negative electrode in which a negative electrode mixture layer was formed was produced. An exposed negative electrode portion in which no mixture layer was present and the surface of the current collector was exposed was provided at the inner end of the negative electrode, and a negative electrode lead made of nickel was welded to the exposed negative electrode portion.
  • SiO Si oxide
  • CMC-Na sodium carboxymethylcellulose
  • SBR styrene-butadiene rubber
  • a porous base material made of polyethylene and having a thickness of 12 ⁇ m was used as the base material layer.
  • Alumina ( ⁇ -Al 2 O 3 ) particles as inorganic particles with an average particle diameter (D50) of 0.7 ⁇ m, acrylic resin particles as resin particles with D50 of 4 ⁇ m, and an acrylic acid ester binder emulsion were mixed into 100 ⁇ m.
  • an appropriate amount of water was added so that the solid content concentration was 10% by mass to prepare a dispersion.
  • This dispersion liquid was applied to the entire surface of a porous base material as a base material layer using a microgravure coater.
  • the coating film was dried by heating in an oven at 50° C. for 4 hours, and a filler layer having convex portions with acrylic resin particles protruding from the surface of the 3 ⁇ m thick inorganic particle layer formed from ⁇ -Al 2 O 3 was formed. was formed.
  • a scanning electron microscope manufactured by Hitachi High-Tech Corporation, SU8220
  • the number of resin particles forming convex portions per predetermined area 100 ⁇ m ⁇ 100 ⁇ m) was 10.
  • a positive electrode and a negative electrode were spirally wound with a separator in between to produce a wound electrode body. At this time, the filler layer of the separator was arranged to face the positive electrode. Insulating plates were placed above and below the electrode body, and the electrode body was housed in an exterior can.
  • the negative electrode lead was welded to the bottom of the bottomed cylindrical outer can, and the positive electrode lead was welded to the sealing body. After injecting the electrolytic solution into the outer can, the opening of the outer can was sealed with a sealant through a gasket, and left to stand in a constant temperature bath at 60° C. for 15 hours to produce a non-aqueous electrolyte secondary battery.
  • the capacity of the produced secondary battery was 4600mAh.
  • Example 2 A secondary battery was produced and evaluated in the same manner as in Example 1, except that in producing the separator, the mixing ratio of acrylic resin particles to 100 parts by mass of ⁇ -Al 2 O 3 particles was changed to 3 parts by mass. Ta. As a result of SEM observation, the number of resin particles forming the convex portion per predetermined area (100 ⁇ m ⁇ 100 ⁇ m) was 18.
  • Example 3 A secondary battery was produced and evaluated in the same manner as in Example 1, except that in producing the separator, the mixing ratio of acrylic resin particles to 100 parts by mass of ⁇ -Al 2 O 3 particles was changed to 6 parts by mass. Ta. As a result of SEM observation, the number of resin particles forming the convex portion per predetermined area (100 ⁇ m ⁇ 100 ⁇ m) was 35.
  • Example 4 In producing the separator, acrylic resin particles with D50 of 6 ⁇ m were used instead of acrylic resin particles with D50 of 4 ⁇ m, and the mixing ratio of acrylic resin particles to 100 parts by mass of ⁇ -Al 2 O 3 particles was changed to 5 parts by mass. Except for this, a secondary battery was produced and evaluated in the same manner as in Example 1. As a result of SEM observation, the number of resin particles forming the convex portion per predetermined area (100 ⁇ m ⁇ 100 ⁇ m) was 25.
  • ⁇ Comparative example 1> In producing the separator, acrylic resin particles with D50 of 6 ⁇ m were used instead of acrylic resin particles with D50 of 4 ⁇ m, and the mixing ratio of acrylic resin particles to 100 parts by mass of ⁇ -Al 2 O 3 particles was changed to 3 parts by mass. Except for this, a secondary battery was produced and evaluated in the same manner as in Example 1. As a result of SEM observation, the number of resin particles forming the convex portion per predetermined area (100 ⁇ m ⁇ 100 ⁇ m) was 5.
  • ⁇ Comparative example 2> In producing the separator, acrylic resin particles with D50 of 1 ⁇ m were used instead of acrylic resin particles with D50 of 4 ⁇ m, and the mixing ratio of acrylic resin particles to 100 parts by mass of ⁇ -Al 2 O 3 particles was changed to 2 parts by mass. Except for this, a secondary battery was produced and evaluated in the same manner as in Example 1. As a result of SEM observation, the number of resin particles forming the convex portion per predetermined area (100 ⁇ m ⁇ 100 ⁇ m) was 8.
  • ⁇ Comparative example 3> A secondary battery was produced and evaluated in the same manner as in Example 1, except that in producing the separator, the mixing ratio of acrylic resin particles to 100 parts by mass of ⁇ -Al 2 O 3 particles was changed to 10 parts by mass. Ta. As a result of SEM observation, the number of resin particles forming the convex portion per predetermined area (100 ⁇ m ⁇ 100 ⁇ m) was 46.
  • Table 1 shows the evaluation results of the secondary batteries according to Examples and Comparative Examples.
  • the liquid permeability is expressed as a relative value with the time when a standard separator is used as 100.
  • Table 1 also shows the D50 of the acrylic resin particles, the mixing ratio of the acrylic resin particles to 100 parts by mass of ⁇ -Al 2 O 3 particles, and the ratio per predetermined area (100 ⁇ m x 100 ⁇ m) of the resin particles forming the convex portion. Also state the number.
  • Configuration 1 A nonaqueous electrolyte secondary battery comprising an electrode body in which a positive electrode and a negative electrode are wound with a separator interposed therebetween, an electrolytic solution, and an outer can housing the electrode body and the electrolytic solution,
  • the separator has a base layer and a filler layer formed on at least one surface of the base layer,
  • the filler layer includes inorganic particles and resin particles having a larger particle size than the inorganic particles, and has a convex portion formed by the resin particles, The convex portion protrudes from the inorganic particle layer formed by the inorganic particles excluding the convex portion of the filler layer,
  • a non-aqueous electrolyte secondary battery wherein when the surface of the filler layer is observed with a scanning electron microscope, 10 to 35 resin particles forming the convex portions are detected in an area of 100 ⁇ m x 100 ⁇ m.
  • Configuration 2 The non-aqueous electrolyte secondary battery according to configuration 1, wherein the average particle size of the resin particles is 1 ⁇ m to 10 ⁇ m larger than the thickness of the inorganic particle layer.
  • Configuration 3 The non-aqueous electrolyte secondary battery according to configuration 1 or 2, wherein the inorganic particles are in contact with the base material layer.
  • Configuration 4 The non-aqueous electrolyte secondary battery according to any one of configurations 1 to 3, wherein the resin particles are adhered to the positive electrode.

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WO2025182338A1 (ja) * 2024-02-29 2025-09-04 パナソニックＩｐマネジメント株式会社 非水電解質二次電池

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014083988A1 (ja) * 2012-11-30 2014-06-05 帝人株式会社 非水系二次電池用セパレータ及び非水系二次電池
WO2021161842A1 (ja) * 2020-02-12 2021-08-19 日本ゼオン株式会社 電気化学素子用積層体及び電気化学素子
JP2022064377A (ja) * 2020-10-14 2022-04-26 東レ株式会社 電池用セパレータ、電極体、非水電解質二次電池、及び電池用セパレータの製造方法

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014083988A1 (ja) * 2012-11-30 2014-06-05 帝人株式会社 非水系二次電池用セパレータ及び非水系二次電池
WO2021161842A1 (ja) * 2020-02-12 2021-08-19 日本ゼオン株式会社 電気化学素子用積層体及び電気化学素子
JP2022064377A (ja) * 2020-10-14 2022-04-26 東レ株式会社 電池用セパレータ、電極体、非水電解質二次電池、及び電池用セパレータの製造方法

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2025182338A1 (ja) * 2024-02-29 2025-09-04 パナソニックＩｐマネジメント株式会社 非水電解質二次電池

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