Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/056—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
• • 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
  • 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
  • H01M50/411—Organic material
  • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
• • 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
  • H01M50/411—Organic material
  • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
  • H01M50/417—Polyolefins
• • 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
  • H01M50/411—Organic material
  • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
  • H01M50/426—Fluorocarbon polymers
• • 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
• • 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
  • H01M2300/0085—Immobilising or gelification of electrolyte
• • 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 electrical energy storage in all-solid batteries, in particular in secondary batteries of the Li-ion type. More specifically, the invention relates to a solid electrolyte consisting of a polymer matrix and a mechanical reinforcement, which allows the manufacture of a non-porous film having a very good compromise between ionic conductivity, electrochemical stability, thermal stability, mechanical strength and fire resistance. This film is intended for an all-solid battery separator or electrolyte application, in particular for Li-ion batteries. The invention also relates to an all-solid battery comprising such a separator and/or such a non-porous film.
• a Li-ion battery includes at least a 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, generally lithium hexafluorophosphate, mixed with a solvent which is a mixture of organic carbonates, chosen to optimize the transport and dissociation of ions.
• a high dielectric constant promotes the dissociation of ions, and therefore the number of ions available in a given volume, while a low viscosity is favorable to ionic diffusion which plays an essential role, among other parameters, in the charging and discharging rates of the electrochemical system.
• Lithium-ion batteries conventionally use liquid electrolytes composed of solvent(s), lithium salt(s) and additive(s). These electrolytes have good ionic conductivity but are prone to leaking or igniting if the battery is damaged.
• solid electrolytes overcomes these difficulties.
• solid electrolytes are generally less conductive than liquid electrolytes.
• the difficulty of solid electrolytes is to reconcile high ionic conductivity, good electrochemical stability and sufficient temperature resistance.
• the ionic conductivity must be equivalent to that of liquid electrolytes (ie around 1 mS/cm at 25°C).
• the electrochemical stability must allow the use of the electrolyte with cathode materials that can operate at high voltage (> 4.5 V).
• the solid electrolyte must operate at least up to 80°C and not ignite below 130°C.
• sufficient mechanical strength must be obtained at the level of the separator. The latter must, in particular, prevent the formation of dendrites during charge/discharge cycles.
• the solid electrolyte must demonstrate better safety, but this cannot be done to the detriment of other performances.
• the solid electrolyte must be able to be manipulated (stretched) and rolled.
• PVDF Poly(vinylidene fluoride)
• P(VDF-HFP) copolymer copolymer of vinylidene fluoride (VDF) and hexafluoropropylene (HFP)
• VDF vinylidene fluoride
• HFP hexafluoropropylene
• Document US 5296318 describes solid electrolyte compositions comprising a mixture of copolymer P (VDF-co-HFP), lithium salt, and compatible solvent with a medium boiling point (i.e. between 100 ° C and 150 ° C), capable of forming an extensible and self-supporting film.
• Example 2 describes the preparation of a film having a thickness of 100 ⁇ m from a composition containing a copolymer P(VDF-HFP), LiPF6 (lithium hexafluorophosphate) and a mixture of ethylene carbonate and propylene carbonate.
• Composite solid electrolytes exhibit improved mechanical properties.
• PVDF/PP/PVDF composites Polypropylene (PP) is Celgard 2400 microporous film.
• PVDF is HSV900 type homopolymer from Shenzhen Kejing Star Technology Co. The composite contains 25 wt% LiCIC.
• a PVDF/PP/PVDF tri-layer film of 100 ⁇ m displays an ionic conductivity of 0.15 mS/cm at 25°C and makes it possible to increase the Young's modulus from 24 to 102 MPa compared to a PVDF monolayer.
• the trilayer is prepared in N,N-dimethylformamide (DMF), and a significant amount of free DMF remains trapped in the PVDF after drying, which limits the electrochemical stability.
• DMF N,N-dimethylformamide
• the object of the invention is therefore to remedy at least one of the drawbacks of the prior art, namely to propose a solid electrolyte composition having performances at least equivalent to those of a liquid electrolyte.
• the invention also relates to a non-porous polymeric film consisting of said composition having good properties of mechanical strength, ionic conductivity and electrochemical stability.
• the invention also aims to provide at least one method for manufacturing this polymeric film.
• Another object of the invention is a separator, in particular for a Li-ion battery consisting, in whole or in part, of said film.
• This separator can also be used in a battery, a capacitor, an electrochemical double layer capacitor, a membrane-electrode assembly (MEA) for a fuel cell or an electrochromic device.
• MEA membrane-electrode assembly
• the invention aims to provide all-solid batteries, in particular rechargeable Li-ion batteries comprising such a separator.
• the invention relates firstly to a solid electrolyte composition consisting of a matrix consisting of the following components a), b) and c): a) at least one copolymer of vinylidene fluoride (VDF) and at least one comonomer compatible with VDF, b) at least one plasticizer, c) at least one lithium salt, and d) at least one mechanical reinforcement (component d).
• VDF vinylidene fluoride
• plasticizer a plasticizer
• lithium salt at least one lithium salt
• mechanical reinforcement component d
• comonomer compatible with VDF is meant a comonomer which can be polymerized with VDF; these monomers are preferably chosen from vinyl fluoride, trifluoroethylene, chloro trifluoroethylene (CTFE), 1,2-difluoroethylene, tetrafluoroethylene (TFE), hexafluoropropylene (HFP), perfluoro (alky vinyl) ethers such as perfluoro (methylvinyl) ether (PMVE), perfluoro (ethylvinyl) ether (PEVE), perfluoro (propylvinyl) ether (PP VE).
• CCTFE chloro trifluoroethylene
• TFE tetrafluoroethylene
• HFP hexafluoropropylene
• perfluoro (alky vinyl) ethers such as perfluoro (methylvinyl) ether (PMVE), perfluoro (ethylvinyl) ether (PEVE), perfluoro
• the VDF copolymer is a terpolymer.
• component a) is at least one copolymer of vinylidene fluoride (VDF) and hexafluoropropylene (HFP), or P(VDF-HFP).
• said P(VDF-HFP) copolymer has a mass content of HFP greater than or equal to 5% and less than or equal to 45%.
• said lithium salt is chosen from the list: LiFSI, LiTFSI, LiTDI, LiPF 6 , LiBF 4 and LiBOB.
• the reinforcement is made of any material that improves the mechanical properties compared to the matrix alone.
• the invention also relates to a non-porous film consisting of said solid electrolyte composition.
• the film does not contain a solvent with a low boiling point (namely below 150° C.) and has a high ionic conductivity.
• Another object of the invention is a separator, in particular for a Li-ion rechargeable battery, comprising a film as described.
• the invention also relates to an electrochemical device chosen from the group: batteries, capacitor, electric electrochemical double-layer capacitor, and membrane-electrode assembly (MEA) for a fuel cell or an electrochromic device, said device comprising a separator as described.
• an electrochemical device chosen from the group: batteries, capacitor, electric electrochemical double-layer capacitor, and membrane-electrode assembly (MEA) for a fuel cell or an electrochromic device, said device comprising a separator as described.
• Another object of the invention is an all-solid lithium-based battery, for example a Li-ion battery, or Li-S or Li-air batteries, comprising a negative electrode, a positive electrode and a separator, in which said separator comprises a film as described.
• the invention also relates to an all-solid battery comprising such a non-porous film.
• the present invention makes it possible to overcome the drawbacks of the state of the art. It more particularly provides a non-porous film capable of functioning as an all-solid battery separator, which combines high ionic conductivity, good electrochemical stability, temperature resistance, and sufficient mechanical strength to allow easy handling.
• the advantage of this invention is to offer a better guarantee of safety compared to a separator or an electrolyte based on liquid electrolyte, for electrochemical performances at least equal to those of liquid electrolytes. There is therefore no possible electrolyte leakage, and the flammability of the electrolyte is greatly reduced.
• the solid electrolyte according to the invention can be used in a battery with an anode made of graphite, silicon or graphite and silicon.
• anode made of graphite, silicon or graphite and silicon.
• its resistance to the growth of dendrites on the surface of the anode also allows a lithium metal anode, which allows a gain in energy density compared to conventional Li-ion technologies.
• Figure 1 is a diagram representing the variation of the tensile force as a function of the elongation for two films: comparative film 1, and film 2 according to the invention.
• the invention relates to a solid electrolyte composition consisting of a matrix consisting of the following components a), b) and c): a) at least one copolymer of vinylidene fluoride (VDF) and at least one comonomer compatible with VDF, b) at least one plasticizer, c) at least one lithium salt, and d) at least one mechanical reinforcement (component d).
• VDF vinylidene fluoride
• b) at least one plasticizer at least one lithium salt
• mechanical reinforcement component d
• said solid electrolyte film comprises the following characteristics, possibly combined.
• the contents indicated are expressed by weight, unless otherwise indicated.
• the concentration ranges given include the limits, unless otherwise indicated.
• Component a) consists of at least one copolymer comprising vinylidene difluoride (VDF) units and one or more types of comonomer units compatible with vinylidene difluoride (hereinafter referred to as "VDF copolymer").
• VDF copolymer contains at least 50% by mass of vinylidene difluoride, advantageously at least 70% by mass of VDF and preferably at least 80% by mass of VDF.
• 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 monomer 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.
• component a) consists of a VDF copolymer.
• component a) consists of a P(VDF-HFP) copolymer.
• the P(VDF-HFP) copolymer has a mass content of HFP greater than or equal to 5%, preferably greater than or equal to 8%, advantageously greater than or equal to 11%, and less than or equal to 45%, preferably less than or equal to 30%.
• said component a) consists of a mixture of two VDF copolymers of different structures.
• component a) consists of a VDF copolymer to which is added a PVDF homopolymer in a mass proportion ranging from 0 to 10% based on the weight of said component a).
• said component a) consists of a mixture of a PVDF homopolymer (in a proportion of up to 10%) and of a P(VDF-HFP) copolymer.
• the VDF copolymer and/or the PVDF homopolymer forming part of the composition of component a) 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, sulphide, oxazoline, phenolics, ester, ether, siloxane, sulphonic, sulfuric, phosphoric, 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 those skilled in the art.
• the functional group bears 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 functional group content of the VDF copolymer and/or of the PVDF homopolymer forming part of the composition of component a) is at least 0.01% molar, preferably at least 0.1% molar, and at most 15% molar, preferably at most 10% molar.
• the VDF copolymer has a high molecular weight.
• high molecular weight as used herein, is meant a copolymer having a melt viscosity greater than 100 Pa.s, preferably greater than 500 Pa.s, more preferably greater than 1000 Pa.s, according to the ASTM D-3835 method measured at 232 ° C and 100 sec -1 .
• VDF copolymers used in the invention can be obtained by known polymerization methods such as polymerization in emulsion, in solution or in suspension.
• they are prepared by an emulsion polymerization process in the absence of fluorinated surfactant.
• said VDF copolymer is a random copolymer.
• This type of copolymer has the advantage of having a homogeneous distribution of the comonomer along the vinylidene fluoride chains.
• said VDF copolymer is a so-called “heterogeneous” copolymer, which is characterized by a non-homogeneous distribution of the comonomer along the VDF chains, due to the synthesis process described by the applicant, for example in document US 6187885 or in document US 10570230.
• a heterogeneous copolymer has two (or more) distinct phases, with a phase rich in homopolymer PVDF and a copolymer phase rich in comonomer.
• the heterogeneous copolymer consists of discontinuous, discrete and individual copolymer domains of comonomer-rich phase, which are homogeneously distributed in a continuous PVDF-rich phase. We then speak of a non-continuous structure.
• the heterogeneous copolymer is a copolymer having two (or more) continuous phases which are intimately linked together and cannot be physically separated. We then speak of a co-continuous structure.
• said heterogeneous copolymer comprises two or more co-continuous phases which comprise: a) from 25 to 50 percent by weight of a first co-continuous phase comprising 90-100 percent by weight of monomer units of vinylidene fluoride and 0 to 10 percent by weight of units of other fluoromonomers, and b) from more than 50% by weight to 75% by weight of a second co-continuous phase comprising from 65 to 95% by weight of vinylidene fluoride monomer units and an effective amount of a or more comonomers, such as hexafluoropropylene and perfluorovinyl ether, to cause phase separation of the co-continuous second phase from the continuous first phase.
• a first co-continuous phase comprising 90-100 percent by weight of monomer units of vinylidene fluoride and 0 to 10 percent by weight of units of other fluoromonomers
• a second co-continuous phase comprising from 65 to 95% by weight of vinylidene fluoride
• the heterogeneous copolymer can be made by forming an initial polymer that is rich in VDF monomer units, generally greater than 90 wt% VDF, preferably greater than 95 wt%, and in a preferred embodiment, a PVDF homopolymer, then adding a co-monomer to the reactor well into the polymerization to produce a copolymer.
• VDF-rich polymer and copolymer will form distinct phases resulting in an intimate heterogeneous copolymer.
• Copolymerization of VDF with a comonomer, for example with HFP 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 micron, preferably less than 800 nm, and more preferably less than 600 nm.
• the weight average size of the particles is generally at least 20 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 whose average size by weight is from 1 to 30 micrometers, and preferably from 2 to 10 micrometers. Agglomerates can break down into discrete particles during formulation and application to a substrate.
• VDF copolymers used in the invention can form a gradient between the core and the surface of the particles, in terms of composition (comonomer content, for example) and/or molecular mass.
• the VDF copolymers contain bio-based VDF.
• bio-based VDF means “derived from biomass”. This improves the ecological footprint of the membrane.
• Bio-based VDF can be characterized by a renewable carbon content, i.e. carbon of natural origin and coming from a biomaterial or biomass, of at least 1 atomic % as determined by the 14C content according to standard NF EN 16640.
• renewable carbon indicates that the carbon is of natural origin and comes from a biomaterial (or from 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 second component of the solid electrolyte composition of the invention consists of at least one plasticizer.
• said plasticizer is an ionic liquid.
• An ionic liquid is a salt that is liquid at room temperature, i.e. it has a melting point below 100°C under atmospheric pressure. It is formed by the association of an organic cation and an anion whose ionic interactions are weak enough not to form a solid.
• this cation may comprise a C1-C30 alkyl group, such as 1-butyl-1-methylpyrrolidinium, 1-ethyl-3-methylimidazolium, N-methyl-N-propylpyrrolydinium or N-methyl-N-butylpiperidinium.
• the anions which are associated with them are chosen from: imides, in particular bis(fluorosulfonyl)imide and bis(trifhioromethanesulfonyl)imide; borates; phosphates; phosphinates and phosphonates, in particular alkyl-phosphonates; amides, in particular dicyanamide; aluminates, in particular tetrachloroaluminate; halides (such as bromide, chloride, iodide anions); cyanates; acetates (CH3COO), in particular trifluoroacetate; sulfonates, in particular methanesulfonate (CH3SO3), trifluoromethanesulfonate; and sulphates, especially hydrogen sulphate.
• imides in particular bis(fluorosulfonyl)imide and bis(trifhioromethanesulfonyl)imide
• borates phosphates; phos
• the anions are chosen from tetrafluoroborate (BFF), bis(oxalato)borate (BOB'), F hexafluorophosphate (PF ⁇ '), hexafluoroarsenate (ASF ⁇ "), triflate or trithioromethylsulfonate (CF3SO3'), bis(thiorosulfonyl)imide (FSF), bis-(trifhioromethanesulfonyl)imide (TFSF), nitrate (NO3') and 4,5-dicyano-2- (trifhioromethyl)imidazole (TDF).
• BFF tetrafluoroborate
• BOB' bis(oxalato)borate
• PF ⁇ ' F hexafluorophosphate
• ASF ⁇ hexafluoroarsenate
• CF3SO3' triflate or trithioromethylsulfonate
• FSF bis(thiorosulfon
• said anion of the ionic liquid is chosen from TDF, FSF, TFSF, PF ⁇ ′, BF 4 ′, NO 3 ⁇ and BOB′.
• said anion of the ionic liquid is FSF.
• said component b) is a mixture of at least two ionic liquids chosen from those described above.
• component b) of the solid electrolyte composition of the invention is a mixture of at least one ionic liquid and at least one solvent with a high boiling point (above 160°C).
• said solvent is chosen from: - vinylene carbonate (VC) (CAS: 872-36-6),
• F2EC trans-4,5-difluoro-l,3-dioxolan-2-one
• PC - propylene carbonate
• - ethers such as poly ethylene glycol dimethyl ethers, in particular diethylene glycol dimethyl ether (EG2DME), triethylene glycol dimethyl ether (EG3DME), and tetraethylene glycol dimethyl ether (EG4DME).
• EG2DME diethylene glycol dimethyl ether
• EG3DME triethylene glycol dimethyl ether
• EG4DME tetraethylene glycol dimethyl ether
• Plasticizers provide improved properties of conductivity, electrochemical stability, thermal stability, compatibility with electrodes, capacity retention compared to conventional liquid electrolytes.
• component b) according to the invention are the following mixtures:
• the mass ratio between the ionic liquids and the solvents forming the compound b) varies from 10:0.1 to 0.1:10.
• the lithium salt present in the solid electrolyte composition comprises the same anion as those of the ionic liquid present in component b).
• said lithium salt is chosen from: LiPF6, LiFSI, LiTFSI, LiTDI, LiBF 4 , LiNO 3 and LiBOB.
• the mechanical reinforcement consists of any material (porous membrane, woven or non-woven) allowing the mechanical properties to be improved compared to the matrix alone (components a+b+c). This may be, without limitation:
• microporous film based on polyolefins such as polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), Celgard® Li-ion separator,
• PVDF polyethersulfone
• PES polyethersulfone
• PSU polysulfone
• a woven substrate e.g. PP, PE, PET, PVDF, PES, PSU, inorganic fibres
• melt blown for example PP, PET, PVDF, PES, PSU
• spunbond substrate for example PP, PET, PVDF, PES, PSU
• the mechanical reinforcement is a multilayer material with at least one polyolefin layer and at least one inorganic layer, for example Celgard® PP coated with an alumina layer on both sides.
• the mechanical reinforcement can be chosen from polymers (for example polyolefin, PVDF, PTFE, polyamide, polyimide, polyaramid, polybenzoaxoles, polybenzimidazoles, polybenzthiazoles, polyphosphazenes, PEKK, PEEK, PES, PSU), carbon fibers (for example "vapor grown carbon fibers” (VGCF®)), carbon nanotubes (NTC), inorganic fibers (for example glass fibers), and vegetable fibers (for example paper, lignin, cellulose, cellulose nanowhiskers).
• polymers for example polyolefin, PVDF, PTFE, polyamide, polyimide, polyaramid, polybenzoaxoles, polybenzimidazoles, polybenzthiazoles, polyphosphazenes, PEKK, PEEK, PES, PSU
• carbon fibers for example "vapor grown carbon fibers” (VGCF®)
• carbon nanotubes for example glass fibers
• vegetable fibers for example paper, lign
• the woven or nonwoven is made of fibers and has a basis weight of less than 50 g/m 2 , preferably less than 30 g/m 2 , preferably less than 20 g/m 2 and advantageously less than 15 g/m 2 .
• the solid electrolyte composition consists of: a) 8 to 66.5% of VDF copolymer(s), b) 4 to 76% of plasticizer(s), and c) 0.8 to 28.5% of lithium salt(s), d) 5 to 60% of mechanical reinforcement, the sum of all the constituents being 100%.
• the solid electrolyte composition consists of:
• the solid electrolyte composition consists of a P(VDF-HFP) copolymer, an EMIM-FSEEG4DME, LiFSI mixture, and a PVDF nonwoven in a mass proportion of 32/44.8/3.2/20, the EMIM-FSVEG4DME mass ratio being 1:1.
• the invention also relates to a non-porous film or membrane consisting of said solid electrolyte composition.
• the film does not contain any solvent and has a high ionic conductivity.
• the film is self-supporting, that is to say it can be manipulated without the aid of a support.
• the film is able to be rolled up, that is to say that it can be manipulated so that it can be rolled up on a reel.
• said film has a thickness of 5 to 60 ⁇ m, preferably from 5 to 30 ⁇ m, more preferably from 7 ⁇ m to 20 ⁇ m.
• the film according to the invention has an ionic conductivity ranging from 0.01 to 5 mS/cm, preferably from 0.05 to 5 mS/cm, advantageously from 0.5 to 5 mS/cm, at 25°C.
• Conductivity is measured by electrochemical impedance spectroscopy.
• the non-porous film is placed between two gold electrodes in a sealed conductivity cell and under an inert atmosphere (CESH, Biology) and an electrochemical impedance spectroscopy is carried out between 1 Hz and 1 MHz with an amplitude of 10 mV.
• the conductivity value at a given temperature is obtained by taking the average of at least two measurements carried out on different samples.
• the film according to the invention has good electrochemical stability over the temperature range from -20°C to 80°C.
• the film according to the invention has a content of solvent(s) with a boiling point of less than 150° C., less than 1% by weight, preferably less than 0.1%, preferably less than 10 ppm.
• the film retains its properties up to 80°C and does not ignite below 130°C.
• the film according to the invention has a mechanical strength characterized by an elastic modulus, measured at 1 Hz and 23° C. by dynamic mechanical analysis, greater than 0.1 MPa, preferably greater than IMPa, even more preferably greater than
• the invention also aims to provide at least one method for manufacturing this non-porous polymeric film.
• said film is manufactured by immersion in a solution containing a, b and c.
• Said at least one VDF copolymer is dissolved at room temperature in a solvent chosen from: n-methyl-2-pyrrolidone, dimethyl sulfoxide, dimethyl formamide, methyl ethyl ketone, acetonitrile, and acetone.
• Said at least one lithium salt is dissolved in a solution of at least one plasticizer, to obtain a lithium salt solution.
• the two solutions are mixed.
• a mechanical reinforcement is then immersed in the final solution.
• the film is then dried, for example at 60° C. under vacuum for 1 night. In the case of acetone, it can be dried in a ventilated oven. A perfectly homogeneous and transparent self-supported film is finally obtained.
• said film is manufactured by coating.
• Said at least one VDF copolymer is dissolved at room temperature in a solvent chosen from: n-methyl-2-pyrrolidone, dimethyl sulfoxide, dimethyl formamide, methyl ethyl ketone, acetonitrile, and acetone.
• Said at least one lithium salt is dissolved in the ionic liquid/plasticizer mixture, to obtain a lithium salt solution. The two solutions are mixed.
• a mechanical reinforcement is coated on one side or both sides, by the mixture thus obtained, for example using a doctor blade.
• the film is then dried, for example at 60° C. under vacuum for 1 night. In the case of acetone, it can be dried in a ventilated oven. A perfectly homogeneous and transparent self-supported film is finally obtained.
• Another object of the invention is an all-solid battery separator consisting, in whole or in part, of said film.
• the invention also relates to an electrochemical device chosen from the group: batteries, capacitor, electric electrochemical double-layer capacitor, and membrane-electrode assembly (MEA) for a fuel cell or an electrochromic device, said device comprising a separator as described.
• an electrochemical device chosen from the group: batteries, capacitor, electric electrochemical double-layer capacitor, and membrane-electrode assembly (MEA) for a fuel cell or an electrochromic device, said device comprising a separator as described.
• Another object of the invention is an all-solid battery, for example a Li-ion battery, or Li-S or Li-air batteries, comprising a negative electrode, a positive electrode and a separator, in which said separator comprises a film as described above.
• said battery comprises a lithium metal anode.
• the invention also relates to an all-solid battery comprising an anode, a cathode and a separator, in which the anode and/or the cathode comprise such a non-porous film.
• P(VDF-HFP) poly(vinylidene fluoride)-co-hexafluoropropylene
• EMIM-FSI lithium bis(fluorosulfonyl)amide
• EMIM-FSI l-ethyl-3-methylimidazolium bis(fluorosulfonyl imide
• EG4DME tetraethylene glycol dimethyl ether
• the residual solvent is measured by GC-MS.
• the amount of acetone is below the detection limit of this technique, i.e. 10 ppm.
• a solid electrolyte of the same composition as example 1 is prepared with a different imbibition process.
• 0.4 g of P(VDF-HFP) (containing 11% of HFP by weight) are dissolved in 1.93 g of acetone at ambient temperature.
• 0.056 g of LiFSI lithium bis (fluoro sulfonyl) amide
• EMIM-FSI l-ethyl-3-methylimidazolium bis (fluoro sulfonyl imide)
• EMIM-FSI l-ethyl-3-methylimidazolium bis (fluoro sulfonyl imide
• EG4DME tetraethylene glycol dimethyl ether
• the final solution is then coated on a non -woven polypropylene (thickness 40 ⁇ m, porosity approximately 50%, weight 18 g/m 2 ) using a doctor blade.
• the height of the doctor blade is greater than the thickness of the nonwoven. It is then dried at 60° C. under vacuum for 1 night. A self-supporting transparent film of approximately 60 ⁇ m is finally obtained.
• the residual solvent is measured by GC-MS.
• the amount of acetone is below the detection limit of this technique, i.e. 10 ppm.
• the conductivity is evaluated by electrochemical impedance spectroscopy by placing the solid electrolyte (prepared under an inert atmosphere) between the two gold electrodes of a cell of sealed conductivity and under inert atmosphere (CESH, Bilogic). 0.26 mS/cm are measured at 25° C. on the submerged solid electrolyte and 0.21 mS/cm at 25° C. on the coated solid electrolyte.
• Figure 1 shows the result of a tensile test carried out on two films of solid electrolyte, in the form of a graph presenting the tensile force applied to each specimen as a function of the elongation.
• the film (1) is composed only of a polymer matrix without mechanical reinforcement, while the film (2) is composed of a matrix (the same matrix as film 1) with a mechanical reinforcement in the form of non-woven polypropylene.

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• Engineering & Computer Science (AREA)
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• Secondary Cells (AREA)
• Cell Separators (AREA)
• Electric Double-Layer Capacitors Or The Like (AREA)
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• 2022
  • 2022-01-21 FR FR2200536A patent/FR3132163B1/fr active Active
• 2023
  • 2023-01-18 CN CN202380017965.9A patent/CN118575324A/zh active Pending
  • 2023-01-18 KR KR1020247027297A patent/KR20240140930A/ko active Pending
  • 2023-01-18 JP JP2024543161A patent/JP2025504867A/ja active Pending
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