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
  • H01M4/621—Binders
  • H01M4/622—Binders being polymers
  • H01M4/623—Binders being polymers fluorinated polymers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/052—Li-accumulators
  • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• • 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
  • H01M4/13—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
  • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
  • H01M4/139—Processes of manufacture
  • H01M4/1393—Processes of manufacture of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• • 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
  • H01M4/1395—Processes of manufacture of electrodes based on metals, Si or alloys
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/36—Selection of substances as active materials, active masses, active liquids
  • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
  • H01M4/381—Alkaline or alkaline earth metals elements
  • H01M4/382—Lithium
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/36—Selection of substances as active materials, active masses, active liquids
  • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
  • H01M4/386—Silicon or alloys based on silicon
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/36—Selection of substances as active materials, active masses, active liquids
  • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
  • H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/36—Selection of substances as active materials, active masses, active liquids
  • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
  • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
  • H01M4/5835—Comprising fluorine or fluoride salts
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/36—Selection of substances as active materials, active masses, active liquids
  • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
  • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
  • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
• • 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
  • 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
  • H01M4/626—Metals
• • 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
  • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
  • H01M2004/027—Negative electrodes
• • 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
  • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
  • H01M2004/028—Positive electrodes
• • 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 generally to the field of electrical energy storage in rechargeable secondary batteries of Li-ion type. More specifically, the invention relates to an electrode formulation for a Li-ion battery, comprising a binder based on a mixture of fluoropolymers. The invention also relates to a process for preparing electrodes using said formulation, by a solvent-free deposition technique on a metal substrate. Finally, the invention relates to an electrode obtained by this process as well as to secondary Li-ion batteries comprising at least one such electrode.
• a Li-ion battery includes at least one negative electrode or anode coupled to a copper current collector, a positive electrode or cathode coupled to an aluminum current collector, a separator, and an electrolyte.
• the electrolyte consists of a lithium salt, usually lithium hexafluorophosphate, mixed with a solvent which is a mixture of organic carbonates, chosen to optimize the transport and dissociation of ions.
• Rechargeable or secondary batteries are more advantageous than primary (non-rechargeable) batteries because the associated chemical reactions that take place at the positive and negative electrodes of the battery are reversible.
• the electrodes of the secondary cells can be regenerated several times by the application of an electric charge.
• Many advanced electrode systems have been developed to store electrical charge. At the same time, many efforts have been devoted to the development of electrolytes capable of improving the capacities of electrochemical cells.
• the electrodes generally comprise at least one current collector on which is deposited, in the form of a film, a composite material which consists of: a so-called active material because it has electrochemical activity with respect to the lithium, a polymer which acts as a binder, plus one or more electronically conductive additives which are generally carbon black or acetylene black, and optionally a surfactant. Binders are counted among the so-called inactive components because they do not directly contribute to the capacity of cells.
• a composite material which consists of: a so-called active material because it has electrochemical activity with respect to the lithium, a polymer which acts as a binder, plus one or more electronically conductive additives which are generally carbon black or acetylene black, and optionally a surfactant. Binders are counted among the so-called inactive components because they do not directly contribute to the capacity of cells.
• binders The main relevant physical and chemical properties of binders are: thermal stability, chemical and electrochemical stability, tensile strength (strong adhesion and cohesion), and flexibility.
• the main objective of the use of a binder is to form stable networks of the solid components of the electrodes, that is to say the active materials and the conductive agents (cohesion).
• the binder must ensure close contact of the composite electrode to the current collector (adhesion).
• PVDF Poly (vinylidene fluoride)
• NMP N-methyl pyrrolidone
• the use of organic solvents requires the significant investment of means of production, recycling and purification. If lithium-ion battery electrodes are produced using a solvent-free process, meeting the same specifications, then the carbon footprint and production costs will be significantly reduced.
• the article by Wang et al. (J. Electrochem. Soc. 2019 166 (10): A2151-A2157) analyzed the influence of several properties of PVDF binders on electrodes manufactured by a dry powder coating process (electrostatic spray deposition). To improve the adhesion to the metal substrate and the cohesion of the electrode, a one hour heat treatment step at 200 ° C is performed. The electrode contains 5% by weight of binder. Two binders of different viscosities are used: HSV900 (50 kPoise) and one grade of Alfa Aesar (25 kPoise).
• the fluid binder leads to the best adhesion but a poorer behavior at high discharge speed than the viscous binder (the capacity retention improves under these conditions, from 17% to 50% without reducing the bond strength and long-term cycling performance).
• the porosity of the binder layer increases with the molecular weight of PVDF.
• the aim of the invention is therefore to provide a Li-ion battery electrode composition capable of being transformed.
• the invention also aims to provide a method for manufacturing an electrode for a Li-ion battery using said formulation, by a solvent-free deposition technique on a metal substrate. Finally, the invention relates to an electrode obtained by this process.
• the invention aims to provide rechargeable Li-ion secondary batteries comprising at least one such electrode.
• the technical solution proposed by the present invention is an electrode composition for a Li-ion battery, comprising a binder based on a mixture of at least two fluoropolymers having different melt viscosities.
• the invention relates firstly to a Li-ion battery electrode comprising an active load for anode or cathode, an electronically conductive load, and a fluoropolymer (based) binder.
• said binder consists of a mixture of two fluoropolymers, a fluoropolymer A, and a fluoropolymer B, said fluoropolymers A and B having different melt viscosities.
• the invention also relates to a method of manufacturing a Li-ion battery electrode, said method comprising the following steps: mixing the active filler, the polymer binder and the conductive filler using a method which allows to obtain an electrode formulation applicable on a metal support by a “solvent-free” process; deposition of said electrode formulation on the metal substrate by a so-called “solvent-free” process, to obtain a Li-ion battery electrode, and consolidation of said electrode by a thermal and / or thermomechanical treatment.
• the invention also relates to a Li-ion battery electrode manufactured by the method described above.
• Another object of the invention is a Li-ion secondary battery comprising a negative electrode, a positive electrode and a separator, in which at least one electrode is as described above.
• the present invention overcomes the drawbacks of the state of the art. It more particularly provides a technology which makes it possible to: control the distribution of the binder and of the conductive filler at the surface of the active filler; ensure the cohesion and mechanical integrity of the electrode, guaranteeing good film formation or consolidation of the formulations which may be difficult to achieve for solvent-free processes; generate adhesion to the metal substrate; ensuring the homogeneity of the electrode composition across the thickness and width of the electrode; control the porosity of the electrode and ensure its homogeneity in the thickness and the width of the electrode; reduce the overall level of binder in the electrode, which, in the case of known solvent-free processes, remains higher compared to a standard “slurry” process, improve the mechanical strength of self-supported films of electrode formulations.
• the formulation makes it possible to obtain a mechanical behavior. sufficient for handling and winding / unwinding phases.
• the advantage of this technology is to improve the following properties of the electrode: the homogeneity of the composition in thickness, the homogeneity of the porosity, the cohesion, and the adhesion to the metal substrate. It also makes it possible to reduce the level of binder required in the electrode, as well as to reduce the temperature and / or the heat treatment time to control the porosity and improve adhesion.
• the invention relates to a Li-ion battery electrode comprising an active load for anode or cathode, an electronically conductive load, and a fluoropolymer binder.
• said binder consists of a mixture of at least two fluoropolymers having different viscosities in the molten state, namely: a fluoropolymer A whose viscosity in the molten state is greater than or equal to 1000 Pa.s to
• said electrode comprises the following characters, combined where appropriate. The contents indicated are expressed by weight, unless otherwise indicated.
• fluoropolymer is meant a polymer comprising fluorine -F groups.
• the fluoropolymer contains in its chain at least one monomer chosen from compounds containing a vinyl group capable of opening in order to polymerize and which contains, directly attached to this vinyl group, at least one fluorine atom, a fluoroalkyl group or a fluoroalkoxy group.
• the fluoropolymer entering into the composition of each of the polymers A and B can be: a homopolymer, or a copolymer comprising two or more fluorinated monomers listed above, or alternatively mixtures of homopolymer and of copolymer, or mixtures of two copolymers ; it can also include non-fluorinated comonomers such as ethylene.
• Fluoropolymers A and B can have similar structures (comprising the same monomers), or else have different structures.
• said binder contains: a fluoropolymer A which comprises a homopolymer of VDF and / or at least one copolymer of vinylidene fluoride (VDF) and of hexafluoropropylene (HFP), of which the viscosity in the molten state is greater than or equal to 1000 Pa.s at 232 ° C and under a shear of 100 s 1 , and a fluoropolymer B which comprises a VDF homopolymer and / or at least one VDF-HFP copolymer, said fluoropolymer B having a viscosity at least 250 Pa.s at 232 ° C and under 100 s shear 1 less than that of polymer A.
• a fluoropolymer A which comprises a homopolymer of VDF and / or at least one copolymer of vinylidene fluoride (VDF) and of hexafluoropropylene (HFP), of which the viscosity
• the fluoropolymer A comprises a VDF homopolymer and / or at least one VDF-HFP copolymer having an HFP level greater than or equal to 1% by weight, preferably greater than or equal to 3%, advantageously greater than or equal to 6%.
• Said VDF-HFP copolymer has an HFP level of less than or equal to 55%, preferably 50%.
• the fluoropolymer A consists of a single VDF-HFP copolymer with an HFP rate greater than or equal to 1%.
• the level of HFP in this VDF-HFP copolymer is between 3% and 55% limits included, preferably between 6% and 50% limits included.
• the fluoropolymer A consists of a mixture of two or more VDF-HFP copolymers, the HFP level of each copolymer being greater than or equal to 1%.
• each of the copolymers has an HFP level of between 3% and 55% limits included, preferably between 6% and 50% limits included.
• the fluoropolymer A is a homopolymer of vinylidene fluoride (VDF) or a mixture of homopolymers of vinylidene fluoride.
• the fluoropolymer A has a melt viscosity greater than or equal to 1000 Pa.s, preferably greater than or equal to 1500 Pa.s, and advantageously greater than or equal to 2000 Pa.s at 232 ° C and at a shear of 100 s 1 .
• the viscosity is measured at 230 ° C, at a shear gradient of 100 s 1 using a capillary rheometer or a rheometer at parallel plates, according to ASTM D3825. Both methods give similar results.
• the fluoropolymer B is a mixture of PVDF homopolymer with a VDF-HFP copolymer or else a mixture of two or more VDF-HFP copolymers.
• the fluoropolymer B is a homopolymer of vinylidene fluoride (VDF) or a mixture of homopolymers of vinylidene fluoride.
• the fluoropolymer B consists of a single VDF-HFP copolymer with an HFP rate greater than or equal to 1%.
• the level of HFP in this VDF-HFP copolymer is between 3% and 55% limits included, preferably between 6% and 50% limits included.
• the fluoropolymer B has a lower viscosity of at least 250 Pa.s at 232 ° C. and under a shear of 100 s 1 than that of polymer A, and preferably at least 500 Pa.s than that of polymer A and advantageously less by at least 750 Pa.s than that of polymer A.
• the fluoropolymers used in the invention can be obtained by known polymerization methods such as solution, emulsion or suspension polymerization. According to one embodiment, they are prepared by an emulsion polymerization process in the absence of fluorinated surfactant.
• said mixture contains: i. a mass content of polymer A greater than or equal to 1% and less than or equal to 20%, preferably greater than or equal to 5% and less than or equal to 20%, and ii. a mass content of polymer B less than or equal to 99% and greater than or equal to 80%, preferably less than or equal to 95% and greater than or equal to 80%.
• the materials active at the negative electrode are generally lithium metal, graphite, silicon / carbon composites, silicon, fluorinated graphites of CF X type with x between 0 and 1 and titanates of LiTisOn type.
• the materials active at the positive electrode are generally of the L1MO 2 type, of the L1MPO 4 type, of the L1 2 MPO 3 F type, of the LLMSiCL type where M is Co, Ni, Mn, Fe or a combination of these, of the type LiM CL or type Sx.
• the conductive fillers are 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.
• a mixture of these conductive fillers can also be produced.
• the reuse of carbon nanotubes in association with another conductive filler such as carbon black can have the advantages of reducing the level of conductive charges in the electrode and of reducing the level of polymer binder due to a specific surface area. less compared to carbon black.
• a polymeric dispersant which is distinct from said binder, is used in admixture with the conductive filler to break up the agglomerates present and to help its dispersion in the final formulation with the polymeric binder and the active filler.
• the polymeric dispersant is chosen from poly (vinyl pyrrolidone), poly (phenyl acetylene), poly (meta-phenylene vinylidene), polypyrrole, poly (para-phenylene benzobisoxazole, poly (vinyl alcohol), and mixtures thereof.
• the mass composition of the electrode is:
• polymer binder 25 to 0.05% polymer binder, preferably 25 to 0.5%
• At least one additive chosen from the list: plasticizers, ionic liquid, dispersing agent for conductive fillers, flow agent for the formulation, fibrillation agent such as polytetrafluoroethylene (PTLE). the sum of all these percentages being 100%.
• the invention also relates to a method of manufacturing a Li-ion battery electrode, said method comprising the following steps:
• solvent-free process is understood to mean a process which does not require a residual solvent evaporation step downstream of the deposition step.
• thermo-mechanical process such as extrusion, calendering or thermo-compression
• the polymers A and B are in powder form, the average particle size of which is between 10 nm and 1 mm, preferably between 50 nm and 500 ⁇ m and even more preferably between 50 nm and 50 ⁇ m.
• Fluoropolymer powder can be obtained by various methods.
• the powder can be obtained directly by a process of synthesis in emulsion or suspension by spray drying (“spray drying”), by lyophilization (“freeze drying”).
• the powder can also be obtained by grinding techniques, such as cryo-grinding.
• the particle size can be adjusted and optimized by selection or sieving methods.
• the polymers A and B are introduced at the same time as the active and conductive charges at the time of the mixing step.
• the polymers A and B are mixed together before mixing with the active and conductive fillers.
• a mixture of polymers A and B can be produced by co-atomization of the latexes of polymers A and B to obtain a mixture under powder form. The mixture thus obtained can, in turn, be mixed with the active and conductive fillers.
• Another embodiment of the mixing step is to proceed in two stages. First, either Polymer A, Polymer B, or both, is mixed with a conductive filler by a solvent-free process or by co-atomization. This step makes it possible to obtain an intimate mixture of the binder and the conductive filler. Then, in a second step, the binder, the pre-mixed conductive filler and any fluoropolymer not yet used are mixed with the active filler. The mixing of the active charge with said intimate mixture is done using a solvent-free mixing process, to obtain an electrode formulation.
• Another embodiment of the mixing step is to proceed in two stages. First, either polymer A or polymer B, or both, is mixed with an active filler by a solvent-free process or a method of spraying a liquid containing the binder and / or the conductive filler onto a fluidized powder bed of the active charge. This step makes it possible to obtain an intimate mixture of the binder and the active filler. Then, in a second step, the binder, the active filler and any fluoropolymer not yet used are mixed with the conductive filler.
• Another embodiment of the mixing step is to proceed in two stages. First, an active filler is mixed with a conductive filler by a solvent-free process. Then, in a second step, either one mixes the two polymers A and B at the same time with the active filler and the conductive filler premixed, or one mixes the polymers A and B one after the other with the active filler and the conductive filler premixed.
• mixing by stirring mixing by air jet, mixing at high shear, mixing by V-mixer, mixing by mass mixer. screw, mixing by double cone, mixing by drum, conical mixing, mixing by double Z-arm, mixing in a fluidized bed, mixing in a planetary mixer, mixing by mechanical fusion, mixing by extrusion, mixing by calendering, mixing by grinding.
• mixing routes using a liquid such as water such as spray drying (co-atomization or “spray drying”) or a process for spraying a liquid containing the binder and / or the spray.
• a liquid such as water
• spray drying co-atomization or “spray drying”
• a process for spraying a liquid containing the binder and / or the spray conductive charge on a fluidized powder bed of the active charge.
• the formulation obtained can undergo a final step of grinding and / or sieving and / or selection to optimize the size of the particles of the formulation for the deposition step on the substrate.
• metallic metallic.
• the powder formulation is characterized by bulk density. It is known in the art of the art that low density formulations are very restrictive in their uses and applications.
• the main components contributing to the increase in density are carbon additives such as carbon black (bulk density less than 0.4 g / cm 3 ), carbon nanotubes (bulk density less than 0.1 g / cm 3) ), polymer powders (bulk density less than 0.9 g / cm 3 ).
• a combination of low density components in order to obtain an additive combining polymer binder / electronic conductor / other additive is recommended to improve the premixing step downstream of the deposition of the formulation described above.
• Such a combination can be carried out by the following methods: a) dispersion of the components in water or the organic solvent followed by the elimination of the solvent (co-atomization, lyophilization, extrusion / compounding in the presence of the solvent or of water ). b) dry or "wet" co-grinding using a grinding method known as a ball or ball mill, followed by a drying step if necessary.
• Such a method is particularly interesting for the significant increase in bulk density.
• the electrode is manufactured by a powdering method without solvent, by depositing the formulation on the metal substrate by a method of pneumatic spraying, electrostatic spraying, soaking in a fluidized powder bed, dusting, electrostatic transfer, deposition with rotating brushes, deposition with rotating metering rollers, calendering.
• the electrode is manufactured by a two-step solvent-free powder coating process.
• a first step which consists in making a self-supported film from the premixed formulation using a thermomechanical process such as extrusion, calendering or thermo-compression. Then, this self-supported film is assembled with the metal substrate by a process combining temperature and pressure such as calendering or thermo-compression.
• the metal supports for the electrodes are generally aluminum for the cathode and copper for the anode.
• Metal substrates can be surface treated and have a conductive primer with a thickness of 5 ⁇ m or more.
• the supports can also be woven or non-woven carbon fiber.
• the consolidation of said electrode is carried out by heat treatment by passing it through an oven, under an infrared radiation lamp, in a calender with heated rollers or in a press with heated plates.
• Another alternative is a two-step process. First, the electrode is heat treated in an oven, under an infrared lamp or in contact with pressureless heating plates. Then a compression step at room temperature or hot is carried out using a calender or a plate press. This step adjusts the porosity of the electrode and improves adhesion to the metal substrate.
• the invention also relates to a Li-ion battery electrode manufactured by the method described above.
• said electrode is an anode.
• said electrode is a cathode.
• Another object of the invention is a Li-ion secondary battery comprising a negative electrode, a positive electrode and a separator, in which at least one electrode is as described above.

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  • 2021-01-29 EP EP21706358.5A patent/EP4097778A1/fr active Pending
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