Classifications

• • 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
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  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
  • H01M4/621—Binders
  • H01M4/622—Binders being polymers
  • H01M4/623—Binders being polymers fluorinated polymers
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  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/052—Li-accumulators
  • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
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  • 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
  • H01M10/0565—Polymeric materials, e.g. gel-type or solid-type
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  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
  • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
• • H—ELECTRICITY
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  • 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
  • H01M4/04—Processes of manufacture in general
  • H01M4/0402—Methods of deposition of the material
  • H01M4/0404—Methods of deposition of the material by coating on electrode collectors
• • H—ELECTRICITY
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  • 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
  • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• • 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
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  • 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
  • H01M4/1391—Processes of manufacture of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• • 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
  • H01M4/624—Electric conductive fillers
  • H01M4/625—Carbon or graphite
• • H—ELECTRICITY
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  • 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
  • H01M4/624—Electric conductive fillers
  • H01M4/626—Metals
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  • 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
  • H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
• • H—ELECTRICITY
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  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M2004/021—Physical characteristics, e.g. porosity, surface area
• • H—ELECTRICITY
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  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
  • H01M2004/028—Positive electrodes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M2300/00—Electrolytes
  • H01M2300/0017—Non-aqueous electrolytes
  • H01M2300/0065—Solid electrolytes
• • 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 generally relates to the field of the storage of electrical energy in rechargeable secondary batteries of the Li-ion type. More specifically, the invention relates to a cathode coating for an all-solid Li-ion battery. The invention also relates to a process for preparing said coating. The invention also relates to a cathode coated with this coating, to the method of manufacturing such a cathode, as well as to Li-ion secondary batteries comprising such a cathode.
• a lithium secondary battery can be used as a power source for a variety of electronic devices ranging from cell phones, laptop computers and small household electronics to vehicles and high capacity energy storage devices and others, and the demand for secondary lithium batteries continues to grow.
• An all-solid-state battery typically includes a positive electrode, a solid electrolyte, and a negative electrode.
• the positive electrode includes a positive electrode active material and a solid electrolyte, and further includes an electronic conductive material and a binder.
• the solid electrolyte comprises one or more elements from the following list: polymer, plasticizer, lithium salt, inorganic particle, ionic liquid.
• the negative electrode includes a negative electrode active material and a solid electrolyte, and further includes a conductive material and a binder.
• the object of the invention is therefore to provide a coating that can be applied directly to a positive electrode of a Li-ion battery, thus making it possible to have a physical separation between the solid electrolyte and the active electrode material and making it possible to use solid electrolytes which seemed unstable vis-à-vis certain active materials.
• the invention also aims to provide a method of manufacturing said cathode coating.
• the invention finally relates to a cathode having such a coating, and to the method of manufacturing such a cathode.
• the invention aims to provide rechargeable Li-ion secondary batteries comprising such a cathode.
• the technical solution proposed by the present invention is to provide a cathode coating which makes it compatible with a solid electrolyte in an all-solid battery.
• the invention relates firstly to a cathode coating consisting of: a. one or more poly(vinylidene fluoride), b. a lithium salt, and c. a conductivity additive.
• the invention also relates to a process for manufacturing a cathode coating from an ink obtained by mixing all the constituents of the coating.
• the invention also relates to a cathode for a lithium-ion battery, said cathode consisting of an active material, a binder and a conductive material, and having a coating layer according to the invention.
• the invention also relates to a method for manufacturing a positive electrode of a Li-ion battery, said method comprising the following operations: supplying a cathode, depositing a coating layer on said cathode.
• Another object of the invention is a Li-ion secondary battery comprising a negative electrode, a positive electrode and an all-solid electrolyte, in which the cathode is as described above.
• the present invention makes it possible to overcome the drawbacks of the state of the art. It provides an ionically conductive coating having a homogeneous distribution of its dielectric constant.
• the coating makes it possible to use positive electrodes without solid electrolytes mixed with the active material of the cathode.
• the coating can be applied directly to a usual positive electrode having a porosity of between 15 and 45% before or after calendering. This coating then makes it possible to have a physical separation between the solid electrolyte and the active material and thus make it possible to use solid electrolytes which seemed unstable vis-à-vis certain active materials.
• the present invention provides a positive electrode comprising a first layer consisting of a usual positive electrode and a second layer consisting of a cathode coating according to the present invention.
• the invention provides a coating with a very good compromise between ionic conductivity, electrochemical stability, high temperature stability, and mechanical strength.
• the invention relates to a cathode coating consisting of: a. one or more poly(vinylidene fluoride) (component A), b. at least one lithium salt (component B), and c. at least one conductivity additive (component C).
• said coating comprises the following characters, possibly combined. The contents indicated are expressed by weight, unless otherwise indicated.
• the semi-crystalline fluorinated polymer used in the invention is a polymer based on vinylidene difluoride and is generically designated by the abbreviation PVDF.
• the PVDF is a poly(vinylidene fluoride) homopolymer or a mixture of homopolymers of vinylidene fluoride.
• the PVDF is a poly(vinylidene fluoride) homopolymer or a copolymer of vinylidene difluoride with at least one comonomer compatible with vinylidene difluoride.
• the PVDF is semi-crystalline.
• Comonomers compatible with vinylidene difluoride can be halogenated (fluorinated, chlorinated or brominated) or non-halogenated.
• fluorinated comonomers examples include: vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, trifluoropropenes and in particular 3,3,3-trifluoropropene, tetrafluoropropenes and in particular 2,3,3,3-tetrafluoropropene or 1 , 3,3,3-tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropenes and in particular 1,1,3,3,3-pentafluoropropene or 1,2,3,3,3-pentafluoropropene, perfluoroalkylvinylethers and in particular those of general formula Rf—O—CF—CF2, Rf being an alkyl group, preferably C1 to C4 (preferred examples being perfluoropropyl vinylether and perfluoromethylvinylether).
• the fluorinated comonomer can contain a chlorine or bromine atom. It can in particular be chosen from bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoroethylene and chlorotrifluoropropene.
• Chlorofluoroethylene can denote either 1-chloro-1-fluoroethylene or 1-chloro-2-fluoroethylene.
• the 1-chloro-1-fluoroethylene isomer is preferred.
• the chlorotrifluoropropene is preferably 1-chloro-3,3,3-trifluoropropene or 2-chloro-3,3,3-trifluoropropene.
• the VDF copolymer can also comprise non-halogenated monomers such as ethylene, and/or acrylic or methacrylic comonomers.
• the fluoropolymer preferably contains at least 50 mole percent vinylidene difluoride.
• the PVDF is a copolymer of vinylidene fluoride (VDF) and hexafluoropropylene (HFP)) (P(VDF-HFP)), having a percentage by weight of hexafluoropropylene monomer units of 2 to 23%, preferably from 4 to 15% by weight relative to the weight of the copolymer.
• the PVDF is a mixture of a poly(vinylidene fluoride) homopolymer and a VDF-HFP copolymer.
• the PVDF is a copolymer of vinylidene fluoride and tetrafluoroethylene (TFE).
• the PVDF is a copolymer of vinylidene fluoride and chlorotrifluoroethylene (CTFE).
• the PVDF is a VDF-TFE-HFP terpolymer.
• the PVDF is a VDF-TrFE-TFE terpolymer (TrFE being trifluoroethylene).
• the mass content of VDF is at least 10%, the comonomers being present in variable proportions.
• the PVDF is a mixture of two or more VDF-HFP copolymers.
• the PVDF comprises monomer units bearing at least one of the following functions: carboxylic acid, carboxylic acid anhydride, carboxylic acid esters, epoxy groups (such as glycidyl), amide, hydroxyl, carbonyl, mercapto, sulfide, oxazoline, phenolics, ester, ether, siloxane, sulfonic, sulfuric, phosphoric, or phosphonic.
• the function is introduced by a chemical reaction which can be grafting, or a copolymerization of the fluorinated monomer with a monomer bearing at least one of said functional groups and a vinyl function capable of copolymerizing with the fluorinated monomer, according to techniques well known by the man of the trade.
• the functional group carries a carboxylic acid function which is a group of (meth)acrylic acid type chosen from acrylic acid, methacrylic acid, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate and hydroxyethylhexyl(meth)acrylate.
• the units carrying the carboxylic acid function also comprise a heteroatom chosen from oxygen, sulphur, nitrogen and phosphorus.
• the functionality is introduced via the transfer agent used during the synthesis process.
• the transfer agent is a polymer with a molar mass less than or equal to 20,000 g/mol and carrying functional groups chosen from the groups: carboxylic acid, carboxylic acid anhydride, carboxylic acid esters, epoxy groups (such as glycidyl), amide, hydroxyl, carbonyl, mercapto, sulfide, oxazoline, phenolics, ester, ether, siloxane, sulfonic, sulfuric, phosphoric, or phosphonic.
• An example of such a transfer agent are acrylic acid oligomers.
• the content of functional groups of the PVDF is at least 0.01% molar, preferably at least 0.1% molar, and at most 15% molar, preferably at most 10% molar.
• the PVDF preferably has a high molecular weight.
• high molecular weight as used herein, is meant a PVDF having a melt viscosity greater than 100 Pa.s, preferably greater than 500 Pa.s, more preferably greater than 1000 Pa.s, preferably greater than at 2000 Pa.s.
• the viscosity is measured at 232° C., at a shear rate of 100 s 1 using a capillary rheometer or a parallel plate rheometer, according to standard ASTM D3825. Both methods give similar results.
• PVDF homopolymers and the VDF copolymers used in the invention can be obtained by known polymerization methods such as emulsion polymerization.
• they are prepared by an emulsion polymerization process in the absence of fluorinated surfactant.
• Polymerization of PVDF results in a latex generally having a solids content of 10 to 60% by weight, preferably 10 to 50%, and having a weight average particle size of less than 1 micrometer, preferably less than 1000 nm , preferably less than 800 nm, and more preferably less than 600 nm.
• the weight average size of the particles is generally at least 10 nm, preferably at least 50 nm, and advantageously the average size is in the range of 100 to 400 nm.
• the polymer particles can form agglomerates, called secondary particles, the average size of which by weight is less than 5000 ⁇ m, preferably less than 1000 ⁇ m, advantageously between 1 to 80 micrometers, and preferably from 2 to 50 micrometers.
• the PVDF homopolymer and the VDF copolymers are composed of bio-based VDF.
• bio-based VDF can be characterized by a renewable carbon content, i.e. carbon of natural origin and coming from a biomaterial or from biomass, of at least 1 atomic % as determined by the content of 14C according to standard NF EN 16640.
• renewable carbon indicates that the carbon is of natural origin and comes from a biomaterial (or biomass), as indicated below.
• the bio-carbon content of the VDF can be greater than 5%, preferably greater than 10%, preferably greater than 25%, preferably greater than or equal to 33%, preferably greater than 50% , preferably greater than or equal to 66%, preferably greater than 75%, preferably greater than 90%, preferably greater than 95%, preferably greater than 98%, preferably greater than 99%, advantageously equal to 100% .
• the lithium salt are chosen from LiPFe (lithium hexafluorophosphate), LiFSI (bis(fluorosulfonyl)lithium imide), TFSI (bis(trifluoromethylsulfonyl)imide lithium, LiTDI (2-trifluoromethyl-4,5-lithium dicyano-imidazolate), LiPOFz, LiBttALL, I e Lil ⁇ BtC ALL, LiBF4, LiNOs, LiCICL and mixtures of two or more of cited salts.
• LiPFe lithium hexafluorophosphate
• LiFSI bis(fluorosulfonyl)lithium imide)
• TFSI bis(trifluoromethylsulfonyl)imide lithium
• LiTDI 2,-trifluoromethyl-4,5-lithium dicyano-imidazolate
• LiPOFz LiBttALL, I e Lil ⁇ BtC ALL, LiBF4, LiNOs, LiCICL and mixtures of two
• the conductivity additive can be an organic molecule or a mixture of organic molecules capable of swelling the fluoropolymer without dissolving it and having a dielectric constant greater than 1.
• component C is chosen from linear ethers or cyclics, esters, lactones, nitriles, carbonates and ionic liquids.
• ethers such as for example dimethoxyethane (DME), methyl ethers of oligoethylene glycols with 2 to 5 oxyethylene units, dioxolane, dioxane , dibutyl ether, tetrahydrofuran, and mixtures thereof.
• DME dimethoxyethane
• methyl ethers of oligoethylene glycols with 2 to 5 oxyethylene units dioxolane, dioxane , dibutyl ether, tetrahydrofuran, and mixtures thereof.
• esters mention may be made of phosphoric acid esters or sulfite esters. Mention may be made, for example, of methyl formate, methyl acetate, methyl propionate, ethyl acetate, butyl acetate, gamma butyrolactone or mixtures thereof.
• lactones mention may in particular be made of cyclohexanone.
• nitriles mention may be made, for example, of acetonitrile, pyruvonitrile, propionitrile, methoxypropionitrile, dimethylaminopropionitrile, butyronitrile, isobutyronitrile, valeronitrile, pivalonitrile, isovaleronitrile, glutaronitrile, methoxyglutaronitrile, 2-methylglutaronitrile, 3-methylglutaronitrile, adiponitrile, malononitrile, and mixtures thereof.
• cyclic carbonates such as for example ethylene carbonate (EC) (CAS: 96-49-1), propylene carbonate (PC) (CAS: 108-32-7) , butylene carbonate (BC) (CAS: 4437-85-8), dimethyl carbonate (DMC) (CAS: 616-38-6), diethyl carbonate (DEC) (CAS: 105-58-8 ), methyl ethyl carbonate (EMC) (CAS: 623-53-0), diphenyl carbonate (CAS 102-09-0), methyl phenyl carbonate (CAS: 13509-27-8), diphenyl dipropyl carbonate (DPC) (CAS: 623-96-1), methyl propyl carbonate (MPC) (CAS: 1333-41-1), ethyl propyl carbonate (EPC), vinylene (VC) (CAS: 872-36-6), fluoroethylene carbonate (EEC) (CAS: 114435-02
• EMIM:FSi PYR:FSI
• EMIM:TFSI PYR:TFSI
• EMIM:B0B PYR:BOB
• EMIM:TDI PYR:TDI
• EMIM :BF4 the PYR:BF4.
• the mass composition of the cathode coating according to the invention is:
• the invention also relates to a process for manufacturing the cathode coating described above from an ink obtained by mixing all the constituents of the coating in a solvent.
• the inks used to make the coatings can be produced by any type of mixer known to those skilled in the art, such as a planetary mixer, centrifugal mixer, orbital mixer, a stirrer shaft, an ultrathurax.
• the different constituents of the ink are not added in a specific order.
• the manufacture of the ink can be carried out at different temperatures ranging from room temperature to the boiling temperature of the solvent used to manufacture the ink.
• the solvent used is preferably a polar solvent with a Hansen parameter greater than 2.
• acetone acetyl triethyl citrate (ATEC), y-butyrolactone (GBL) , cyclohexanone (CHO), cyclopentanone (CPO), dibutyl phthalate (DBP), dibutyl sebacate (DBS), diethyl carbonate (DEC), diethyl phthalate (DEP), dihy funny voglucosenone (Cyrene), dimethylacetamide (DM Ac), N,N-dimethylformamide (DMF), dimethyl sulf oxide (DMSO), 1,4-dioxane, 3-Heptanone, hexamethyl phosphoramide (HMPA), 3-hexanone, methyl ethyl ketone (MEK), N-methyl-2- pyrrolidinone (NMP), 3-octanone, 3-pentanone, propylene carbonate (PC), tetrahydrofuran
• the porosity of the coated cathode according to the invention is less than 10%, preferably less than 5%.
• the porosity of the coated electrode is obtained according to the following calculation described in the publication of M.CAI, Nature Communications, 10, 2019, 4597: where VER represents the actual volume of the coated electrode and calculated by multiplying the area of the coated electrode with the thickness of the coated electrode. VdenseER represents the volume occupied by each of the constituents without any porosity and is calculated according to the following formula:
• VdenseER is the sum of the volume occupied by each constituent of the coated electrode.
• the thickness of this coating can range from 0.1 to 100 ⁇ m, preferentially from 0.1 to 50 ⁇ m and more preferentially from 0.1 to 35 ⁇ m.
• the invention also relates to a cathode for an all-solid lithium-ion battery, said cathode comprising, preferably consisting of, an active material, a binder and a conductive material, and having a coating layer according to the invention.
• Said cathode is deposited on a metallic support. Said cathode thus forms a first layer on said metallic support.
• MnCL manganese dioxide
• iron oxide
• Ni ⁇ Nio.s-XxCh Al,Fe,Cr,Co,Rh,Nd, other rare earths with 0 ⁇ x ⁇ 0,l
• vanadium oxides sulfur type Ss and mixtures thereof.
• the electronic conductive material is chosen from carbon blacks, graphites, natural or synthetic, carbon fibers, carbon nanotubes, metal fibers and powders, and conductive metal oxides. Preferably, they are chosen from carbon blacks, graphites, natural or synthetic, carbon fibers and carbon nanotubes.
• the binder used to manufacture the cathode is a polymer chosen from polyolefins (for example: polyethylene or polypropylene), fluorinated polymers (PVDF) which may have acid functions, polyacrylic acids (PAA), polyacrylonitriles (PAN), polymers of cellulose type, polyphenylsulfone, polyethersulfone, a phenolic resin, a vinyl ester resin, an epoxy resin, or a liquid-crystal polymer.
• PVDF fluorinated polymers
• PAA polyacrylic acids
• PAN polyacrylonitriles
• polymers of cellulose type polyphenylsulfone, polyethersulfone, a phenolic resin, a vinyl ester resin, an epoxy resin, or a liquid-crystal polymer.
• this coating is electrochemically stable up to 5 V.
• said cathode forming said first layer comprises less than 3% by weight, advantageously less than 1% by weight, preferably less than 0.5% by weight, more preferably less than 0.1% by weight, in particular is devoid of solid electrolyte based on the total weight of said cathode; said solid electrolyte being preferentially present in said coating layer according to the present invention.
• the invention also relates to a method for manufacturing a positive electrode of a Li-ion battery, said method comprising the following operations: supplying a cathode, depositing on said cathode a coating layer according to the invention.
• This coating can be produced by any deposition method known to those skilled in the art, such as solvent-based coating, soaking-withdrawal methods, centrifugal coating, spray coating or calendering. These deposition techniques can be carried out at different temperatures ranging from 5°C to 180°C.
• the coating can be applied directly to a usual positive electrode having a porosity of between 15 and 45% before or after calendering. This coating then makes it possible to have a physical separation between the solid electrolyte and the active material and thus make it possible to use solid electrolytes which seemed unstable with respect to certain active materials.
• the method for manufacturing a Li-ion battery positive electrode comprises, upstream of the deposition of the coating according to the invention, the following steps: - mixing of the active filler, of the polymer binder and of the conductive filler using a process which makes it possible to obtain an electrode formulation which can be applied to a metallic support;
• thermo-mechanical treatment such as calendering
• the metallic supports of the electrodes are generally made of aluminum for the cathode.
• Metallic supports can be surface treated and have a conductive primer with a thickness of 5 ⁇ m or more.
• the supports can also be wovens or nonwovens made of carbon fiber.
• the positive electrode comprises a metal support on which is deposited a first layer comprising, preferably consisting of, an active material, a binder and a conductive material, and a second layer deposited on said first layer; said second layer consisting of said cathode coating according to the present invention.
• Another object of the invention is an all-solid Li-ion secondary battery comprising a negative electrode, a positive electrode and an all-solid electrolyte, in which the cathode is as described above.
• VDF-HFP copolymer with a mass content of HFP of 23% are dissolved in 85.753 g of acetone using a planetary mixer at 2000 rpm for six times 1 min to obtain complete dissolution.
• LiFSI LiFSI 0.2 g
• PF polymer solution
• LiFSI LiFSI
• tetraethylene glycol dimethyl ether tetraethylene glycol dimethyl ether
• LiFSI LiFSI
• 0.616 g of tetraethylene glycol dimethyl ether Sl (Cas 143-24-8) using a magnetic stirrer for 10 min at 21°C.
• 3.52 g of a 25% PF solution in acetone are added.
• a cathode of NMC622 with the following formulation NMC622/HSV1810/C45 97/1.5/1.5 is coated with ink B.
• the electrode before coating has an average porosity of 44% and a density of 2.51 g /cm3.
• the coating is made by coating. After drying at room temperature, the coating represents a weight of 18.04 mg/cm2 which allows the coating to fill all the porosity of the electrode.
• the ionic conductivity of the electrode was measured by impedance spectroscopy at 0.033 mS/cm.
• a commercial NMC532 cathode with a thickness of 71 ⁇ m is coated with V ink using a bar coater.
• the wet thickness deposited is 200 ⁇ m.
• the coating is dried by heating to 35°C.
• the coated electrode is then calendered to achieve a total thickness of 91 ⁇ m.
• a power test was performed to compare an electrode coated with V ink to a standard electrode.
• Method the method consists of charging a battery at a slow speed of C/10 and discharging it at different speeds and thus measuring the capacity that can be restored by the battery at different discharge speeds.
• Electrolyte IM LiPFô in EC/EMC 3/7 by volume
• Fiberglass separator Anode Lithium metal
• Table 1 shows the capacity restored in discharge by the two batteries for two different regimes.

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• 2021
  • 2021-09-27 FR FR2110142A patent/FR3127635A1/fr active Pending
• 2022
  • 2022-09-23 CN CN202280064865.7A patent/CN118020161A/zh active Pending
  • 2022-09-23 WO PCT/FR2022/051794 patent/WO2023047064A1/fr not_active Ceased
  • 2022-09-23 EP EP22792853.8A patent/EP4409651A1/fr active Pending
  • 2022-09-23 JP JP2024518828A patent/JP2024534622A/ja active Pending
  • 2022-09-23 KR KR1020247013961A patent/KR20240069798A/ko active Pending
  • 2022-09-23 US US18/692,862 patent/US20250140858A1/en active Pending
  • 2022-09-26 TW TW111136374A patent/TWI844118B/zh active

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