Hybrid fluoropolymer electrolyte membrane

Abstract

This invention relates to a method for manufacturing a fluoropolymer electrolyte membrane comprising a fluoropolymer hybrid organic / inorganic composite for use in electrochemical batteries, a polymer electrolyte membrane obtainable by the method, as well as films and membranes thereof, and an electrochemical battery comprising a polymer electrolyte membrane between a positive electrode and a negative electrode. The invention also relates to the use of the polymer electrolyte membrane obtainable by the method according to the invention in electrochemical devices, particularly secondary batteries.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to European Patent Application No. 19197491.4, filed on September 16, 2019, the entire contents of which are incorporated herein by reference for all purposes. Technical Field

[0003] This invention relates to a method for manufacturing a fluoropolymer electrolyte membrane comprising a fluoropolymer hybrid organic / inorganic composite material for use in electrochemical batteries, a polymer electrolyte membrane obtainable by the method, and an electrochemical battery comprising the polymer electrolyte membrane between a positive electrode and a negative electrode. The invention also relates to the use of the polymer electrolyte membrane obtainable by the method according to the invention in electrochemical devices, particularly secondary batteries. Background Technology

[0004] Hybrid organic / inorganic polymer composites, in which inorganic materials at the nanoscale or molecular level are dispersed in organic polymers, have attracted widespread scientific, technological, and industrial interest due to their unique properties.

[0005] The hybridization of organic and inorganic compounds is a sophisticated method for fabricating polymer structures (notably improving mechanical properties). In this regard, the sol-gel method using metal alkoxy compounds is well-known as the most useful and important method for preparing hybrid organic / inorganic polymer composites. Specifically, the hydrolysis and condensation of metal alkoxy compounds can be appropriately controlled in the presence of a pre-formed organic polymer to obtain hybrid organic / inorganic polymer composites with improved properties compared to the original organic and inorganic compounds. The polymer, as an organic compound, can enhance the toughness and processability of inorganic materials, i.e., metal alkoxy compounds, which are typically brittle, while the inorganic network can improve the scratch resistance, mechanical properties, and surface properties of the resulting hybrid organic / inorganic polymer composites.

[0006] Hybrids made from fluoropolymers, especially vinylidene fluoride polymers, via sol-gel technology are known in the art.

[0007] For example, WO 2011 / 121078 discloses a method for manufacturing fluoropolymer hybrid organic / inorganic composites, wherein at least a portion of the hydroxyl groups of the fluoropolymer are reacted with a compound having formula X in solution or in the molten state. 4-m AY m The reaction involves at least a portion of the hydrolyzable groups of a metal compound (where X is a hydrocarbon group, Y is a hydrolyzable group, A is a metal selected from Si, Ti, and Zr, and m is an integer from 1 to 4). The choice of solvent for dissolving the fluoropolymer is not critical, provided that it can effectively react the fluoropolymer with the metal compound having the formula X.4-m AY m The metal compound and the solvent form a solvate and do not interfere with the reaction between the hydroxyl groups of the fluoropolymer and the hydrolyzable groups of the metal compound. However, the solvent needs to be evaporated by drying to produce the film. The patent document also mentions that swelling of the electrolyte solution containing a mixture of ethylene carbonate and propylene carbonate and LiPF6 occurs in the film made of the hybrid organic / inorganic composite material. Furthermore, once the film is cast, swelling may continue, and the final amount of liquid electrolyte that eventually permeates into the film will be reduced, thereby correspondingly reducing the ionic conductivity.

[0008] To address these drawbacks, WO 2013 / 160240 discloses the fabrication of fluoropolymer hybrid organic / inorganic composites in the presence of a liquid medium to provide a self-supporting fluoropolymer membrane that stably contains and retains the liquid medium while exhibiting excellent ionic conductivity. When used as a polymer electrolyte membrane in an electrochemical device, the hybrid organic / inorganic composite is obtained by a method comprising hydrolysis and / or polycondensation of a fluoropolymer having the formula X. 4-m AY m A mixture of a metal compound, an ionic liquid, a solvent, and an electrolytic salt. The resulting liquid mixture is then processed into a thin film by casting.

[0009] However, the method according to WO 2013 / 160240 requires the use of processing solvents such as acetone, N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), etc., all of which need to be evaporated by drying / heating at the end of processing to produce a film, and are therefore undesirable in industrial production processes.

[0010] WO 2015 / 169834 also describes a method for manufacturing a fluoropolymer hybrid organic / inorganic composite material with excellent crosslinking density characteristics, good ionic conductivity, and increased electrolyte retention capacity within the polymer electrolyte membrane. However, this method requires processing a solvent to prepare the polymer solution, thus necessitating an evaporation step of the processing solvent to obtain the membrane.

[0011] Aside from the inconvenience of requiring additional steps to remove the processing solvent used in the method, and its disadvantages in terms of processability and industrialization, such processing solvents, notably acetone, comply with the ATEX Directive 94 / 9 / EC adopted by the European Union (EU) in 1994. The ATEX Directive sets out the technical and legal requirements for products intended for use in hazardous areas with potentially flammable atmospheres. The name ATEX Directive is derived from the French title of Directive 94 / 9 / EC, namely, "(Appareilsdestinésà"). "Utilities in Explosive Atmospheres". Since July 2003, products that have obtained ATEX type approval within the EU must be used. Therefore, any product placed on the market or used in hazardous environments as defined by the ATEX Directive must comply with the standards specified therein. These standards vary depending on the classification of the hazardous area. Consequently, solvents containing acetone, which are considered capable of generating explosive atmospheres, are often a concern for manufacturers in the battery industry.

[0012] Therefore, there is exploration in this field of methods for producing fluoropolymer hybrid organic / inorganic composites without using processing solvents.

[0013] To meet this need in this field, several solutions have been considered. One approach is to find alternative solvents with better ATEX properties without sacrificing any solubility characteristics, grafting rates, or other parameters that may affect film formation. Another approach is to find an alternative method that does not require any processing solvents when preparing polymer solutions. Summary of the Invention

[0014] Therefore, the present invention provides a method for manufacturing a fluoropolymer electrolyte membrane comprising a fluoropolymer hybrid organic / inorganic composite material for use in electrochemical devices, the method comprising the following steps:

[0015] a) Dissolving i) at least one fluoropolymer in ii) at least one liquid medium, wherein i) at least one fluoropolymer comprises:

[0016] -Derived from at least one first repeating unit of at least one olefinically unsaturated fluorinated monomer, and

[0017] -Derived from at least one second repeating unit of at least one olefinic unsaturated monomer having at least one hydroxyl group;

[0018] b) Reacting at least a portion of the hydroxyl groups of at least one fluoropolymer (i) with at least one metal compound having formula (I).

[0019] X 4-m AY m (I)

[0020] Where m is an integer from 1 to 3, A is a metal selected from the group consisting of Si, Ti, and Zr, Y is a hydrolyzable group, and X is a hydrocarbon group containing at least one isocyanate (-N=C=O) functional group, thereby providing a composition comprising at least one grafted fluoropolymer, the grafted fluoropolymer comprising at least one hydrogenated monomer having at least one side chain comprising the formula -OC(O)-NH-Z-AY m X 3-mThe terminal groups, wherein m, Y, A and X have the same meaning as defined above and Z is a hydrocarbon group, optionally containing at least one -N=C=O functional group;

[0021] c) Make it have the formula -OC(O)-NH-Z-AY m X 3-m The end group reacts with at least one metal compound having formula (II) in (iv).

[0022] X' 4-m’ A'Y' m’ (II)

[0023] Where m' is an integer from 1 to 4, A' is a metal selected from the group consisting of Si, Ti, and Zr, Y' is a hydrolyzable group, optionally containing at least one functional group other than -N=C=O, and X' is a hydrocarbon group, thereby providing a composition comprising at least one fluoropolymer hybrid organic / inorganic composite material; and

[0024] d) Process the composition from step c) into a polymer electrolyte membrane.

[0025] Its characteristic is that there is no drying step.

[0026] A second object of the present invention is a polymer electrolyte membrane, which can be obtained as defined above.

[0027] A third object of the present invention is an electrochemical device comprising a polymer electrolyte membrane as defined above between a positive electrode and a negative electrode.

[0028] Another object of the present invention is the use of polymer electrolyte membranes as defined above in electrochemical devices, particularly in secondary batteries.

[0029] The applicant has now unexpectedly discovered that it is possible to manufacture fluoropolymer electrolyte membranes containing fluoropolymer hybrid organic / inorganic composites without using processing solvents to dissolve the fluoropolymers, with the further advantage of avoiding the subsequent recycling and treatment of the solvents.

[0030] In particular, the applicant discovered that a liquid medium containing at least one organic solvent can replace the processing solvent to dissolve the fluoropolymer. Therefore, the production of fluoropolymer electrolyte membranes eliminates the need for a drying step involving the evaporation of the processing solvent, and furthermore, several issues related to the ATEX regulations are resolved.

[0031] The fluoropolymer electrolyte membrane according to the invention is characterized in that it does not contain metal salts, such as lithium salts. As disclosed in WO2017 / 216184, this characteristic can be supplemented by utilizing the feature of metal salts migrating from either the positive or negative electrode into the electrolyte membrane within the electrochemical device, thereby ensuring good electrochemical performance. Detailed Implementation

[0032] Throughout this specification, unless the context otherwise requires, the terms "comprise" or "include," or variations thereof such as "comprises," "comprising," "includes," and "including," shall be understood to mean including the stated elements or method steps or groups of elements or method steps, but not excluding any other elements or method steps or groups of elements or method steps. According to a preferred embodiment, the terms "comprise" and "include," and variations thereof, mean "consisting only of...".

[0033] As used herein, the singular forms “a / an” and “the” include the plural cases unless the context clearly indicates otherwise. The term “and / or” includes the meaning of “and”, “or”, and also includes all other possible combinations of the elements associated with the term.

[0034] The term “between” should be understood to include the limit value.

[0035] As used herein, “alkyl” includes saturated hydrocarbons having one or more carbon atoms, including straight-chain alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl; cyclic alkyl groups (or “cycloalkyl” or “alicyclic” or “carbocyclic” groups) such as cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl; branched alkyl groups such as isopropyl, tert-butyl, sec-butyl, and isobutyl; and alkyl-substituted alkyl groups such as alkyl-substituted cycloalkyl and cycloalkyl-substituted alkyl groups.

[0036] The term "aliphatic group" refers to organic parts characterized by being straight or branched, typically having between 1 and 18 carbon atoms. In complex structures, these chains can be branched, bridged, or cross-linked. Aliphatic groups include alkyl, alkenyl, and alkynyl groups.

[0037] As used in this article, the term “(Cn-Cm)” for organic groups, where n and m are integers, indicates that the group may contain from n to m carbon atoms per group.

[0038] This document may express ratios, concentrations, amounts, and other numerical data in the form of ranges. It should be understood that this range form is used only for convenience and brevity and should be flexibly interpreted to include not only the numerical values ​​explicitly stated as the limits of the range, but also all individual numerical values ​​or subranges encompassed within that range, just as each numerical value and subrange is explicitly stated. For example, a temperature range of approximately 120°C to approximately 150°C should be understood to include not only the explicitly stated limits of approximately 120°C to approximately 150°C, but also subranges such as 125°C to 145°C, 130°C to 150°C, etc., and individual quantities within the specified range, including small quantities such as 122.2°C, 140.6°C, and 141.3°C.

[0039] The following describes in detail the components of a method for manufacturing a fluoropolymer electrolyte membrane comprising a fluoropolymer hybrid organic / inorganic composite for use in an electrochemical device according to the present invention. It should be understood that the foregoing general description and the following detailed description are exemplary and intended to provide further explanation of the claimed invention. Therefore, various variations and modifications described herein will be apparent to those skilled in the art. Furthermore, for clarity and brevity, descriptions of well-known functions and constructions may be omitted.

[0040] The first objective of this invention is a method for manufacturing a fluoropolymer electrolyte membrane comprising a fluoropolymer hybrid organic / inorganic composite material for use in electrochemical devices, the method comprising the following steps:

[0041] a) Dissolving i) at least one fluoropolymer in ii) at least one liquid medium, wherein i) at least one fluoropolymer comprises:

[0042] -Derived from at least one first repeating unit of at least one olefinically unsaturated fluorinated monomer, and

[0043] -Derived from at least one second repeating unit of at least one olefinic unsaturated monomer having at least one hydroxyl group;

[0044] b) Reacting at least a portion of the hydroxyl groups of at least one fluoropolymer (i) with at least one metal compound having formula (I).

[0045] X 4-m AY m (I)

[0046] Where m is an integer from 1 to 3, A is a metal selected from the group consisting of Si, Ti, and Zr, Y is a hydrolyzable group, and X is a hydrocarbon group containing at least one isocyanate (-N=C=O) functional group, thereby providing a composition comprising at least one grafted fluoropolymer, the grafted fluoropolymer comprising at least one hydrogenated monomer having at least one side chain comprising the formula -OC(O)-NH-Z-AY m X 3-m The terminal groups, wherein m, Y, A and X have the same meaning as defined above and Z is a hydrocarbon group, optionally containing at least one -N=C=O functional group;

[0047] c) Make it have the formula -OC(O)-NH-Z-AY m X 3-m The end group reacts with at least one metal compound having formula (II) in (iv).

[0048] X' 4-m’ A'Y' m’ (II)

[0049] Where m' is an integer from 1 to 4, A' is a metal selected from the group consisting of Si, Ti, and Zr, Y' is a hydrolyzable group, optionally containing at least one functional group other than -N=C=O, and X' is a hydrocarbon group, thereby providing a composition comprising at least one fluoropolymer hybrid organic / inorganic composite material; and

[0050] d) Process the composition from step c) into a polymer electrolyte membrane.

[0051] Its characteristic is that there is no drying step.

[0052] The fluoropolymer electrolyte membrane according to the invention is advantageously free of one or more metal salts, including but not limited to one or more metal salts selected from the group consisting of:

[0053] -MeI, Me(PF6) n Me(BF4) n Me(ClO4) n Me (di(oxalate)borate) n (Me(BOB)) n ”), MeCF3SO3, Me[N(CF3SO2)2] n Me[N(C2F5SO2)2] n 、Me[N(CF3SO2)(R F SO2)] n , where R F Is it C2F5, C4F9, CF3OCF2CF2, or Me(AsF6)? nMe[C(CF3SO2)3] n Me2S n ,

[0054] Where Me is a metal, preferably a transition metal, alkali metal or alkaline earth metal, more preferably Li, Na, K or Cs, even more preferably Li, and n is the valence of the metal, typically n is 1 or 2;

[0055] -

[0056] Where R' F Choose from the following groups: F, CF3, CHF2, CH2F, C2HF4, C2H2F3, C2H3F2, C2F5, C3F7, C3H2F5, C3H4F3, C4F9, C4H2F7, C4H4F5, C5F 11 C3F5OCF3, C2F4OCF3, C2H2F2OCF3, and CF2OCF3; and

[0057] - its combination

[0058] In one embodiment, step c) is performed while heating at room temperature or at a temperature below 100°C.

[0059] In a preferred embodiment, step c) is performed at a temperature between 50°C and 100°C, and more preferably between 70°C and 90°C.

[0060] In step c), iv) at least one metal compound having formula (II) as defined above and from step b) having formula -OC(O)-NH-Z-AY m X 3-m The end groups are hydrolyzed and / or polycondensed.

[0061] In a preferred embodiment, the hydrolysis and / or polycondensation in step c) as defined above are initiated by the addition of at least one acid catalyst. The choice of acid catalyst is not particularly limited. The acid catalyst is typically selected from the group consisting of organic and inorganic acids. Preferably, the acid catalyst is selected from the group consisting of organic acids (e.g., citric acid and formic acid). In a preferred embodiment, the acid catalyst is formic acid.

[0062] In this invention, the term "membrane" is intended to refer to a discrete and generally thin interface that mitigates the penetration of chemical species in contact with it. This interface can be homogeneous, i.e., structurally completely uniform (dense membrane), or it can be chemically or physically non-homogeneous, for example, containing voids, pores, or holes of finite size (porous membrane).

[0063] In this invention, the term "fluoropolymer" is intended to refer to a (co)polymer in which at least one hydrogen atom is replaced by fluorine. One, two, three or more hydrogen atoms may be replaced by fluorine.

[0064] Polyvinylidene fluoride (PVDF or VDF polymer) is one of the most widely used fluoropolymers in battery components because it has high anodic stability and high dielectric constant, which is beneficial for the ionization of lithium salts in lithium-ion batteries and allows ion flow, thereby improving battery performance.

[0065] According to one embodiment, the first repeating unit is derived from at least one olefinically unsaturated fluorinated monomer, namely vinylidene fluoride (VDF), chlorotrifluoroethylene (CTFE), hexafluoropropylene (HFP), tetrafluoroethylene (TFE), trifluoroethylene, and combinations thereof.

[0066] In one embodiment, the fluoropolymer of the present invention comprises two first repeating units derived from at least one olefinically unsaturated fluorinated monomer. In a specific embodiment, the two first repeating units are VDF and CTFE. In another specific embodiment, the two first repeating units are VDF and TFE. In a preferred embodiment, the two first repeating units are VDF and HFP.

[0067] In one embodiment, the first repeating unit according to the invention is a VDF (co)polymer.

[0068] In this invention, VDF polymer refers to a polymer that is essentially composed of repeating units, wherein more than 85% of the repeating units are derived from VDF on a molar basis.

[0069] The VDF polymer is preferably a polymer containing the following:

[0070] (a) At least 85% of the repeating units are derived from VDF;

[0071] (b) optionally, from 0.1% to 15%, preferably from 0.1% to 12%, more preferably from 0.1% to 10% by molar amount of repeating units derived from fluorinated monomers different from VDF; and

[0072] (c) optionally from 0.1% to 5% on a molar basis, preferably from 0.1% to 3% on a molar basis, more preferably from 0.1% to 1% on a molar basis, repeating units derived from one or more hydrogenated comonomers,

[0073] All the above molar percentages refer to the total number of repeating units of the VDF polymer.

[0074] Non-limiting examples of suitable fluorinated monomers other than VDF as i) the first repeating unit include the following:

[0075] -C2-C8 perfluoroolefins, such as tetrafluoroethylene and hexafluoropropylene (HFP);

[0076] -C2-C8 hydrogenated fluoroolefins, such as fluoroethylene, 1,2-difluoroethylene and trifluoroethylene;

[0077] -Having the formula CH2=CH-R f0 Perfluoroalkyl ethylene, wherein R f0 It is a C1-C6 perfluoroalkyl group;

[0078] -Chloro- and / or brominated- and / or iodo-C2-C6 fluoroolefins, such as chlorotrifluoroethylene;

[0079] -With the formula CF2 = CFOR f1 (Per)fluoroalkyl vinyl ethers, wherein R f1 It is a C1-C6 fluoro- or perfluoroalkyl group, such as CF3, C2F5, C3F7;

[0080] -CF2=CFOX0 (per)fluoro-oxyalkyl vinyl ether, where X0 is C1-C 12 Alkyl, C1-C 12 oxyalkyl or C1-C having one or more ether groups 12 (Per)fluoroalkyl groups, such as perfluoro-2-propoxy-propyl;

[0081] -With the formula CF2=CFOCF2OR f2 (Per)fluoroalkyl vinyl ethers, wherein R f2 It is a C1-C6 fluoro- or perfluoroalkyl group, such as CF3, C2F5, C3F7, or a C1-C6 (per)fluorooxyalkyl group having one or more ether groups, such as -C2F5-O-CF3;

[0082] - A (per)fluoro-oxyalkyl vinyl ether having the formula CF2=CFOY0, wherein Y0 is C1-C 12 Alkyl or (per)fluoroalkyl, C1-C 12 oxyalkyl or C1-C having one or more ether groups 12 (All)fluoroalkyl, and Y0 includes a carboxylic acid or sulfonic acid group (in the form of its acid, acyl halide or salt); and

[0083] -Fluorodioxane, preferably perfluorinated m-dioxane.

[0084] In a preferred embodiment, the fluorinated monomer serving as the first repeating unit is advantageously selected from the group consisting of: vinyl fluoride, trifluoroethylene, trifluorochloroethylene (CTFE), 1,2-difluoroethylene, tetrafluoroethylene (TFE), hexafluoropropylene (HFP), perfluoro(alkyl) vinyl ethers (such as perfluoro(methyl) vinyl ether (PMVE), perfluoro(ethyl) vinyl ether (PEVE), and perfluoro(propyl) vinyl ether (PPVE)), perfluoro(1,3-m-dioxacyclopentene), and perfluoro(2,2-dimethyl-1,3-m-dioxacyclopentene) (PDD). Preferably, possible additional fluorinated monomers are selected from the group consisting of: trifluorochloroethylene (CTFE), hexafluoropropylene (HFP), trifluoroethylene (TrFE), and tetrafluoroethylene (TFE).

[0085] In a more preferred embodiment, the fluorinated monomer is hexafluoropropylene (HFP).

[0086] In another embodiment, non-limiting examples of VDF (co)polymers as the first repeating unit of the fluoropolymer in this invention include, notably, homopolymers of VDF, VDF / TFE copolymers, VDF / TFE / HFP copolymers, VDF / TFE / CTFE copolymers, VDF / TFE / TrFE copolymers, VDF / CTFE copolymers, VDF / HFP copolymers, VDF / TFE / HFP / CTFE copolymers, etc. In particular, VDF / HFP copolymers have attracted considerable attention due to their good compatibility with electrodes, their low transition temperature, and their crystallinity (which enables improved ionic conductivity).

[0087] The hydrogenated comonomer is not particularly limited; α-olefins, (meth)acrylic acid monomers, vinyl ether monomers, and styrene monomers can be used.

[0088] Therefore, VDF polymers are more preferably polymers composed essentially of the following:

[0089] (a) At least 85% of the repeating units are derived from VDF;

[0090] (b) Optionally from 0.1% to 15%, preferably from 0.1% to 12%, more preferably from 0.1% to 10% on a molar basis, of a fluorinated monomer different from VDF; said fluorinated monomer is preferably selected from the group consisting of: vinyl fluoride, trifluorochloroethylene (CTFE), hexafluoropropylene (HFP), tetrafluoroethylene (TFE), perfluoromethyl vinyl ether (MVE), trifluoroethylene (TrFE), and mixtures thereof.

[0091] All the above molar percentages refer to the total number of repeating units of the VDF polymer.

[0092] In addition to the repeating units, defects, end chains, impurities, chain inversions or branches, etc., may additionally exist in the VDF polymer, and these components do not substantially change the behavior and properties of the VDF polymer.

[0093] According to one embodiment, the second repeating unit is derived from (meth)acrylate having hydroxyl groups.

[0094] According to one embodiment, the hydroxyl-containing (meth)acrylate includes 2-hydroxyethyl acrylate (HEA), 2-hydroxyethyl methacrylate, 2-hydroxymethyl acrylate, 2-hydroxymethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 6-hydroxyhexyl acrylate, 6-hydroxyhexyl methacrylate, 8-hydroxyoctyl acrylate, 8-hydroxyoctyl methacrylate, 2-hydroxyethylene glycol acrylate, 2-hydroxyethylene glycol methacrylate, 2-hydroxypropylene glycol acrylate, 2-hydroxypropylene glycol methacrylate, 2,2,2-trifluoroethyl acrylate, and 2,2,2-trifluoroethyl methacrylate.

[0095] In a preferred embodiment, the second repeating unit is HEA.

[0096] In one embodiment, the fluorinated copolymer comprises, on a molar basis, from 0.1% to 20.0%, preferably from 0.1% to 15.0%, and more preferably from 0.1% to 10.0% of a second repeating unit derived from at least one olefinic unsaturated monomer having a hydroxyl group.

[0097] In a preferred embodiment, the fluorinated copolymer comprises:

[0098] The molar percentage ranges from 90.0% to 99.9% from the first repeating unit derived from at least one olefinic unsaturated fluorinated monomer.

[0099] The second repeating unit derived from at least one olefinic unsaturated monomer having a hydroxyl group, ranging from 0.1% to 10.0% by molar amount.

[0100] In a more preferred embodiment, the fluorinated copolymer comprises:

[0101] The VDF content, ranging from 80.0% to 99.8% by molar, and the HFP content, ranging from 0.1% to 10.0% by molar, serve as the first repeating unit derived from at least one olefinic unsaturated fluorinated monomer; and

[0102] HEA, measured in molar amounts from 0.1% to 10.0%, is used as a second repeating unit derived from at least one olefinic unsaturated monomer having a hydroxyl group.

[0103] liquid medium

[0104] In this invention, the term "liquid medium" is intended to refer to a composition comprising one or more substances that is liquid at atmospheric pressure and 20°C.

[0105] The liquid medium typically comprises at least one organic solvent and optionally at least one ionic liquid.

[0106] There are no particular restrictions on the choice of organic solvent, provided that it is suitable for dissolving the fluoropolymers according to the invention and does not fall under the definition of an explosive atmosphere as defined in ATEX Directive 94 / 9 / EC, wherein an explosive atmosphere is defined as: i) a mixture of flammable substances in the form of gas, vapor, mist or dust; ii) with air; iii) under atmospheric conditions; and iv) wherein, after ignition, combustion spreads throughout the unburned mixture.

[0107] Notably, non-limiting examples of suitable organic solvents include the following:

[0108] - Aliphatic, alicyclic or aromatic ether oxides, more specifically, dibutyl oxide, dipentyl oxide, diisopentyl oxide, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, benzyl oxide;

[0109] - Glycol ethers, such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monon-butyl ether.

[0110] - Glycol ether esters, such as ethylene glycol methyl ether acetate, ethylene glycol monoethyl ether acetate, and ethylene glycol monobutyl ether acetate;

[0111] - Alcohols, such as diacetone alcohol;

[0112] - Ketones, such as methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, isophorone; and

[0113] - Straight-chain or cyclic esters, such as n-butyl acetate, methyl acetoacetate, dimethyl phthalate, and γ-butyrolactone;

[0114] - Straight-chain or cyclic amides, such as N,N-diethylacetamide, N,N-dimethylacetamide, N,N-dimethylformamide, and N-methyl-2-pyrrolidone; and

[0115] - Dimethyl sulfoxide.

[0116] In one embodiment, the organic solvent comprises at least one organic carbonate compound.

[0117] In this invention, the organic carbonate compound may be a partially or fully fluorinated carbonate compound. The organic carbonate compound according to this invention may be a cyclic carbonate or acyclic carbonate.

[0118] Notable non-limiting examples of organic carbonate compounds include ethylene carbonate (1,3-dioxolane-2-one), propylene carbonate, 4-methylene-1,3-dioxolane-2-one, 4,5-dioxolane-1,3-dioxolane-2-one, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, dipropyl carbonate, methyl propyl carbonate, methyl butyl carbonate, ethyl butyl carbonate, propyl butyl carbonate, dibutyl carbonate, di-tert-butyl carbonate, and butylene carbonate.

[0119] Fluorinated carbonate compounds can be monofluorinated or polyfluorinated. Suitable examples of fluorinated carbonate compounds include, but are not limited to, monofluorinated ethylene carbonate (4-fluoro-1,3-dioxolane-2-one) and difluorinated ethylene carbonate, monofluorinated and difluorinated propylene carbonate, monofluorinated and difluorinated butyl carbonate, 3,3,3-trifluoropropylene carbonate, dimethyl fluorinated carbonate, diethyl fluorinated carbonate, methyl ethyl fluorinated carbonate, dipropyl fluorinated carbonate, dibutyl fluorinated carbonate, methyl propyl fluorinated carbonate, and ethyl propyl fluorinated carbonate.

[0120] In a preferred embodiment, the organic carbonate compound is a mixture of ethylene carbonate and propylene carbonate.

[0121] In another preferred embodiment, the organic carbonate compound is a mixture of ethylene carbonate, propylene carbonate, and 4-fluoro-1,3-dioxolane-2-one.

[0122] In another embodiment, the organic solvent comprises at least one organic carbonate compound and at least one sulfone compound. The sulfone compound according to the invention may be a cyclic sulfone or a non-cyclic sulfone.

[0123] Notable non-limiting examples of sulfone compounds include tetramethylene sulfone (sulfolane), butadiene sulfone (sulfolene), pentamethylene sulfone, hexamethylene sulfone, thiazoline 1,1-dioxide, thiomorpholine 1,1-dioxide, dimethyl sulfone, diethyl sulfone, ethylmethyl sulfone, and mixtures thereof.

[0124] In a preferred embodiment, the organic solvent is a mixture of ethylene carbonate, propylene carbonate, 4-fluoro-1,3-dioxolane-2-one, and sulfolane.

[0125] Ionic liquids

[0126] As used herein, the term "ionic liquid" refers to a compound containing positively charged cations and negatively charged anions, which is liquid at atmospheric pressure and at a temperature of 100°C or lower. While ordinary liquids such as water are primarily composed of electrically neutral molecules, ionic liquids are primarily composed of ions and short-lived ion pairs. As used herein, the term "ionic liquid" refers to a solvent-free compound.

[0127] As used herein, the term "cationic atom" refers to at least one positively charged nonmetallic atom.

[0128] As used herein, the term "onium cation" refers to a positively charged ion whose charge is located on at least one nonmetallic atom such as O, N, S or P.

[0129] In this invention, the ionic liquid has the general formula A n- Q l+ (n / l) ,in,

[0130] -A n- Indicates anion;

[0131] -Q l+ (n / l) Indicates a cation;

[0132] -n and l are chosen independently between 1 and 5, representing anion A, respectively. n- and cation Q l+ (n / l) The charge.

[0133] One or more cations may be independently selected from metal cations and organic cations. One or more cations may be monocharged cations or polycharged cations.

[0134] As metal cations, alkali metal cations, alkaline earth metal cations, and cations of d-block elements are preferably mentioned.

[0135] In this invention, Q l+ (n / l) This can refer to an onium cation. An onium cation is a cation formed by an element of Group VB or VIB (as defined by the old European IUPAC system according to the periodic table) with three or four hydrocarbon chains. Group VB includes N, P, As, Sb, and Bi atoms. Group VIB includes O, S, Se, Te, and Po atoms. The onium cation can be, in particular, a cation formed by atoms selected from the group consisting of N, P, O, and S (more preferably N and P) with three or four hydrocarbon chains.

[0136] The onium cation Q l+ (n / l) You can choose from:

[0137] - Heterocyclic onium cations; especially those selected from the group consisting of:

[0138]

[0139] -Unsaturated cyclic onium cations; particularly those selected from the group consisting of:

[0140]

[0141] -Saturated cyclic onium cations; especially those selected from the group consisting of:

[0142]

[0143]

[0144] as well as

[0145] -Acyclic onium cations; particularly those with the general formula + L-R' s Those, where L represents an atom selected from the group consisting of N, P, O, and S, more preferably N and P, s represents the number of R' groups selected from 2, 3, or 4 according to the valence of element L, each R' independently representing a hydrogen atom or a C1 to C8 alkyl group, and in L + The key between R' and R' can be a single key or a double key.

[0146] In the above formula, each "R" symbol independently represents a hydrogen atom or an organic group. Preferably, in the above formula, each "R" symbol may independently represent a hydrogen atom, or optionally a saturated or unsaturated linear, branched, or cyclic C1 to C2 group substituted once or multiple times with a halogen atom, amino, imino, amide, ether, ester, hydroxyl, carboxyl, carbamoyl, cyano, sulfone, or sulfite group. 18 Hydrocarbon group.

[0147] The cation Q l+ (n / l) It can be more specifically selected from cations of ammonium, phosphonium, pyridinium, pyrrolidineium, pyrazolineium, imidazolineium, arsenium, quaternary phosphonium, and quaternary ammonium.

[0148] The quaternary phosphonium cation or quaternary ammonium cation may more preferably be selected from tetraalkylammonium cation or tetraalkylphosphonium cation, trialkylbenzylammonium cation or trialkylbenzylphosphonium cation or tetraarylammonium cation or tetraarylphosphonium cation, wherein the alkyl (same or different) represents a straight-chain or branched alkyl chain having 4 to 12 carbon atoms, preferably 4 to 6 carbon atoms, and wherein the aryl (same or different) represents a phenyl or naphthyl group.

[0149] In a particular embodiment, Q l+ (n / l) This indicates a quaternary phosphonium cation or a quaternary ammonium cation.

[0150] In a preferred embodiment, Q l+ (n / l) This indicates a quaternary phosphonium cation. Non-limiting examples of quaternary phosphonium cations include trihexyl(tetradecyl)phosphonium and tetraalkylphosphonium cations, particularly tetrabutylphosphonium (PBu4) cation.

[0151] In another embodiment, Q l+ (n / l) This indicates an imidazolium cation. Non-limiting examples of imidazolium cations include 1,3-dimethylimidazolium, 1-(4-sulfobutyl)-3-methylimidazolium, 1-allyl-3H-imidazolium, 1-butyl-3-methylimidazolium, 1-ethyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, and 1-octyl-3-methylimidazolium.

[0152] In another embodiment, Q l+ (n / l) The term "quaternary ammonium cation" is specifically selected from the group consisting of: tetraethylammonium, tetrapropylammonium, tetrabutylammonium, trimethylbenzylammonium, methyltributylammonium, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium, N,N-dimethyl-N-ethyl-N-(3-methoxypropyl)ammonium, N,N-dimethyl-N-ethyl-N-benzylammonium, N,N-dimethyl-N-ethyl-N-phenethylammonium, N-tributyl-N-methylammonium, N-trimethyl-N-butylammonium, N-trimethyl-N-hexylammonium, N-trimethyl-N-propylammonium, and Aliquat336 (methyltri(C8 to C18)2-methyl-N ... 10 (A mixture of alkyl)ammonium compounds).

[0153] In one embodiment, Q l+ (n / l) It represents piperidinium cations, especially N-butyl-N-methylpiperidinium and N-propyl-N-methylpiperidinium.

[0154] In another embodiment, Q l+ (n / l) This indicates a pyridinium cation, particularly N-methylpyridinium.

[0155] In a more preferred embodiment, Q l+ (n / l) This indicates a pyrrolidineonium cation. Among specific pyrrolidineonium cations, the following may be mentioned: C 1-12 Alkyl-C 1-12 Alkyl-pyrrolidine onion, and more preferably C 1-4 Alkyl-C 1-4Alkyl-pyrrolidineonium. Examples of pyrrolidineonium cations include, but are not limited to, N,N-dimethylpyrrolidineonium, N-ethyl-N-methylpyrrolidineonium, N-isopropyl-N-methylpyrrolidineonium, N-methyl-N-propylpyrrolidineonium, N-butyl-N-methylpyrrolidineonium, N-octyl-N-methylpyrrolidineonium, N-benzyl-N-methylpyrrolidineonium, N-cyclohexylmethyl-N-methylpyrrolidineonium, and N-[(2-hydroxy)ethyl]-N-methylpyrrolidineonium. More preferably are N-methyl-N-propylpyrrolidineonium (PYR13) and N-butyl-N-methylpyrrolidineonium (PYR14).

[0156] Non-limiting examples of anions in ionic liquids include iodides, bromides, chlorides, hydrogen sulfates, dicyandiamides, acetates, diethyl phosphates, methyl phosphonates, and fluorinated anions (e.g., hexafluorophosphate (PF6)). - ) and tetrafluoroborate (BF4) - And oxaloborate with the following formula:

[0157]

[0158] In one embodiment, A n- It is a fluorinated anion. Among the fluorinated anions that can be used in this invention, fluorinated sulfonamide anions can be particularly advantageous. Organic anions can be particularly selected from anions having the following general formula:

[0159] (E a -SO2)N - R

[0160] in:

[0161] -E a A group representing a fluorine atom or preferably having 1 to 10 carbon atoms, the group being selected from fluoroalkyl, perfluoroalkyl, and fluoroolefinic groups, and

[0162] -R indicates a substituent.

[0163] Preferably, E a It can represent F or CF3.

[0164] According to the first embodiment, R represents a hydrogen atom.

[0165] According to the second embodiment, R represents a straight-chain or branched, cyclic or acyclic, preferably hydrocarbon-based group having 1 to 10 carbon atoms, which may optionally have one or more degrees of unsaturation, and which may optionally be substituted once or multiple times with a halogen atom, a nitrile functional group; or an alkyl group that may optionally be substituted once or multiple times with a halogen atom. Furthermore, R may represent a nitrile group -CN.

[0166] According to the third embodiment, R represents a sulfinate group. Specifically, R can represent the group -SO2-E. a E a As defined above. In this case, the fluorinated anion can be symmetrical, that is, the two E atoms of the anion are such that... a The functional groups are identical or asymmetrical, that is, the two electrons of the anion are identical. a The functional groups are different.

[0167] Furthermore, R can represent the group -SO2-R', where R' represents a straight-chain or branched, cyclic or acyclic, preferably hydrocarbon-based group having 1 to 10 carbon atoms, optionally with one or more unsaturations, and optionally substituted once or multiple times with a halogen atom, a nitrile functional group; or optionally substituted once or multiple times with a halogen atom of an alkyl group. In particular, R' can contain a vinyl or allyl group. Additionally, R can represent the group -SO2-N-R', where R' is as defined above or additionally R' represents a sulfonate functional group -SO3-.

[0168] The cyclic hydrocarbon-based group can preferably refer to a cycloalkyl or aryl group. "Cycloalkyl" refers to a monocyclic hydrocarbon chain having 3 to 8 carbon atoms. Preferred examples of cycloalkyl groups are cyclopentyl and cyclohexyl. "Aryl" refers to a monocyclic or polycyclic aromatic hydrocarbon group having 6 to 20 carbon atoms. Preferred examples of aryl groups are phenyl and naphthyl. When the group is polycyclic, the rings can be condensed or linked by σ (sigma) bonds.

[0169] According to the fourth embodiment, R represents a carbonyl group. R can be specifically represented by the formula -CO-R', where R' is as defined above.

[0170] The organic anions that can be used in this invention can be advantageously selected from the group consisting of: CF3SO2N - SO2CF3 (bis(trifluoromethanesulfonyl)imide anion, usually represented as TFSI), FSO2N - SO2F (bis(fluorosulfonyl)imide anion, usually represented as FSI), CF3SO2N - SO2F and CF3SO2N - SO2N - SO2CF3.

[0171] In a preferred embodiment, the ionic liquid comprises:

[0172] - Positively charged cations selected from the group consisting of imidazolium, pyridinium, pyrrolidineium, and piperidinium ions, optionally containing one or more C1-C ions. 30 Alkyl groups, and

[0173] - Negatively charged anions, selected from the group consisting of: halide ions, fluorinated anions, and borate ions.

[0174] C1-C 30 Notably, non-limiting examples of alkyl groups include: methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, 2,2-dimethyl-propyl, hexyl, 2,3-dimethyl-2-butyl, heptyl, 2,2-dimethyl-3-pentyl, 2-methyl-2-hexyl, octyl, 4-methyl-3-heptyl, nonyl, decyl, undecyl, and dodecyl.

[0175] In this invention, (iii) X in at least one metal compound of formula (I) as defined above, which may be the same as or different from each other and, each time in occurrence, is a straight-chain or branched C containing at least one -N=C=O functional group. 1- C 12 The hydrocarbon group, Y, may be the same as or different from each other and is OR each time it appears, where R is a straight-chain or branched C1-C5 alkyl group, preferably methyl or ethyl.

[0176] (iii) Non-limiting examples of at least one metal compound having formula (I) as defined above include the following: trimethoxysilyl methyl isocyanate, triethoxysilyl methyl isocyanate, trimethoxysilyl ethyl isocyanate, triethoxysilyl ethyl isocyanate, trimethoxysilyl propyl isocyanate, triethoxysilyl propyl isocyanate, trimethoxysilyl butyl isocyanate, triethoxysilyl butyl isocyanate, trimethoxysilyl pentyl isocyanate, triethoxysilyl pentyl isocyanate, trimethoxysilyl hexyl isocyanate, and triethoxysilyl hexyl isocyanate.

[0177] In a preferred embodiment, (iii) at least one metal compound having formula (I) as defined above is triethoxysilylpropyl isocyanate.

[0178] (iv) The choice of at least one hydrolyzable group Y' of a metal compound having formula (II) as defined above is not particularly limited, provided that it is capable of forming the fluoropolymer hybrid organic / inorganic composite material of the present invention under suitable conditions. The hydrolyzable group Y' is typically selected from the group consisting of: halogen atoms (preferably chlorine atoms), hydrogen carboxyl groups, acyloxy groups, and hydroxyl groups.

[0179] If (iv) at least one metal compound having formula (II) as defined above contains at least one functional group other than the -N=C=O functional group on group X', it will be designated as a functional compound. If none of group X' contains a functional group other than the -N=C=O functional group, it will be designated as a non-functional compound.

[0180] A mixture of one or more functional compounds and one or more non-functional compounds may be used as at least one metal compound having formula (II) as defined above in the method of the present invention (iv).

[0181] Functional compounds can advantageously further modify the chemical properties and characteristics of grafted fluoropolymers, making them superior to native fluoropolymers and native inorganic phases.

[0182] Non-limiting examples of functional groups other than -N=C=O functional groups notably include epoxy groups, carboxylic acid groups (in their acid, ester, amide, anhydride, salt, or halide form), sulfonic acid groups (in their acid, ester, salt, or halide form), hydroxyl groups, phosphate groups (in their acid, ester, salt, or halide form), thiol groups, amino groups, quaternary ammonium groups, olefinic unsaturated groups (such as vinyl groups), cyano groups, urea groups, organosilicon groups, and aromatic groups.

[0183] Notable examples of functional compounds include vinyltriethoxysilane, vinyltrimethoxysilane, vinyltrimethoxyethoxysilane having the formula CH2=CHSi(OC2H4OCH3)3, and 2-(3,4-epoxycyclohexylethyltrimethoxysilane) having the following formula:

[0184]

[0185] Glycidoxypropylmethyldiethoxysilanes having the following formula:

[0186]

[0187] Glycidoxypropyltrimethoxysilanes having the following formula:

[0188]

[0189] Methacryloxypropyltrimethoxysilanes having the following formula:

[0190]

[0191] Aminoethylaminopropylmethyldimethoxysilanes having the following formula:

[0192]

[0193] Aminoethylaminopropyltrimethoxysilanes having the following formula:

[0194] H2NC2H4NGC3H6Si(OCH3)3

[0195] 3-Aminopropyltriethoxysilane, 3-Phenylaminopropyltrimethoxysilane, 3-Chloroisobutyltriethoxysilane, 3-Chloropropyltrimethoxysilane, 3-Mercaptopropyltriethoxysilane, 3-Mercaptopropyltrimethoxysilane, n-(3-Acryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane, (3-Acryloyloxypropyl)dimethylmethoxysilane, (3-Acryloyloxypropyl)methyldichlorosilane, (3-Acryloyloxypropyl)methyldimethoxysilane, 3-(n-Allylamino)propyltrimethoxysilane, 2-(4-Chlorosulfonylphenyl)ethyltrimethoxysilane, 2-(4-Chlorosulfonylphenyl)ethyltrichlorosilane, carboxyethylsilane triol and its sodium salt, triethoxysilylpropylmaleamic acid having the following formula:

[0196]

[0197] 3-(trihydroxysilyl)-1-propane-sulfonic acid having the formula HOSO2-CH2CH2CH2-Si(OH)3, N-(trimethoxysilylpropyl)ethylene-diaminetriacetic acid and its sodium salt, and 3-(triethoxysilyl)propylsuccinic anhydride having the formula:

[0198]

[0199] Acetaminopropyltrimethoxysilane having the formula H3C-C(O)NH-CH2CH2CH2-Si(OCH3)3, and Ti(L) X (OR) Y Alkylamine titanate, wherein L is an amine-substituted alkoxy group, such as OCH2CH2NH2, R is an alkyl group, and x and y are integers such that x+y=4.

[0200] Notable examples of nonfunctional compounds include trimethoxysilane, triethoxysilane, tetramethoxysilane (TMOS), tetraethoxysilane (TEOS), tetramethyl titanate, tetraethyl titanate, tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, tetraisobutyl titanate, tetra-tert-butyl titanate, tetra-n-pentyl titanate, tetra-n-hexyl titanate, tetra-isooctyl titanate, tetra-n-lauryl titanate, tetraethyl zirconate, tetra-n-propyl zirconate, tetraisopropyl zirconate, tetra-n-butyl zirconate, tetra-sec-butyl zirconate, tetra-tert-butyl zirconate, tetra-n-pentyl zirconate, tetra-tert-pentyl zirconate, tetra-tert-hexyl zirconate, tetra-n-heptyl zirconate, tetra-n-octyl zirconate, and tetra-n-stearyl zirconate.

[0201] In a preferred embodiment, (iv) at least one metal compound having formula (II) is tetraethoxysilane (TEOS).

[0202] At least one acid catalyst may be added to step c) of the method according to the invention.

[0203] The choice of acid catalyst is not particularly limited. The acid catalyst is typically selected from organic and inorganic acids, preferably from the group consisting of organic acids. Formic acid is a preferred acid that can be used in the method according to the invention.

[0204] A second objective of the present invention is to obtain a polymer electrolyte membrane by means of the method according to the present invention.

[0205] A third object of the present invention is an electrochemical device comprising a polymer electrolyte membrane obtainable by means of the method according to the invention, between a positive electrode and a negative electrode.

[0206] In one embodiment, at least one of the positive electrode and the negative electrode comprises a metal salt, preferably a transition metal salt, an alkali metal salt or an alkaline earth metal salt, more preferably a Li salt, a Na salt, a K salt or a Cs salt, and even more preferably a Li salt.

[0207] Another object of the present invention is the use of polymer electrolyte membranes obtainable by the method according to the invention in electrochemical devices, particularly secondary batteries.

[0208] If any disclosure of any patent, patent application, or publication incorporated herein by reference conflicts with the description of this application to the extent that it may lead to ambiguity in terminology, then this description shall take precedence.

[0209] The invention will now be described in more detail with reference to the following examples, which are for illustrative purposes only and are not intended to limit the scope of the invention.

[0210] Example

[0211] raw materials

[0212] Fluoropolymers: The VDF / HEA / HFP copolymer is available from Solvay Specialty Polymers Italy SpA.

[0213] TSPi: 3-(triethoxysilyl)propyl isocyanate

[0214] Tetraethoxysilane (TEOS): Commercially available as a liquid from Aldrich Chemistry (purity >99%)

[0215] Organic solvents:

[0216] - Ethylene carbonate (EC)

[0217] -Propylene carbonate (PC)

[0218] -Fluoroethylene carbonate (FEC)

[0219] -Sulfolane (SL)

[0220] Example 1

[0221] The fluoropolymer was pre-dried overnight under vacuum at 80°C. 5.0 g of the fluoropolymer (10.0 parts by weight relative to the total weight of one or more organic solvents used) was dissolved in a mixture of EC / PC (1:1 w / w; 45.0 g). After the fluoropolymer was completely dissolved, 106 mg (1.1 mol% relative to the total moles of the fluoropolymer) of TSPi was added to the solution, and the mixture was stirred at 80°C for 60 min. 1.6 g of TEOS was added and stirred for 5 min, followed by 360 mg (1 equivalent of TEOS) of formic acid, also stirred for 5 min, while maintaining the temperature at 80°C. The amount of TEOS was determined by a 10% weight ratio (m...). SiO2 / m 氟聚合物 We will use this to calculate, assuming that TEOS is completely converted into SiO2.

[0222] After adding formic acid, the resulting solution is spread to a constant thickness using a casting machine (scraper). On a 9414 thin film substrate. The film thus prepared is placed at 50°C for 30 minutes to allow the sol-gel reaction to proceed.

[0223] N,N-Dimethylformamide (DMF) is a good solvent for fluoropolymers, but the fluoropolymer electrolyte membrane prepared above, which contains a hybrid organic / inorganic composite material, is insoluble in this solvent. The higher the crosslinking density of the membrane, the lower its solubility in DMF. Therefore, by utilizing this characteristic, the formation of a hybrid organic / inorganic composite material can be checked by a solubility test in DMF. For this purpose, the membrane was placed in approximately 5 mL of DMF for about 1 minute at room temperature.

[0224] Example 2-5

[0225] Examples 2-5 were prepared in the same manner as Example 1, except for the amount of one or more organic solvents used and the amount of F-polymer used only in Example 2. For example, in Example 5, a mixture of EC / PC / FEC / SL (20:10:10:60 w / w) was used instead.

[0226] Comparative Example (Comparative Example 1)

[0227] The fluoropolymer was pre-dried overnight under vacuum at 80°C. 5.0 g of the fluoropolymer (10.0 parts by weight relative to the total weight of one or more organic solvents used) was dissolved in acetone (45.0 g). After complete dissolution of the fluoropolymer, the solution was homogenized and clear at room temperature. 106 mg (1.1 mol% relative to the total moles of the fluoropolymer) of TSPi was added to the solution, and the mixture was stirred at 60°C for 90 min. Then, 1 M LiPF6 dissolved in a 50:50 mixture of EC / MC was added to the solution. Subsequently, 1.6 g of TEOS was added and stirred for 5 min, followed by 360 mg (1 equivalent of comparative TEOS) of formic acid, also stirred for 5 min, while maintaining the temperature at 60°C to produce the polymer electrolyte membrane of Comparative Example 1. An additional drying step was performed to evaporate the acetone.

[0228] However, membranes produced in this way still contain residual acetone, in amounts ranging from 600 ppm to 0.65 w% relative to the total weight of the membrane. This residual acetone can ultimately impair battery cycle performance.

[0229] The detailed composition is mentioned in Table 1 below.

[0230] Table 1

[0231]

[0232]

[0233] *The residual amount of acetone was measured multiple times using a gas chromatograph (Agilent system) with a DB-WAX ultra-inert column [30m (length) * 0.32mm (inner diameter) * 0.5μm (thin film)] under temperature conditions of increasing from 40℃ to 160℃ (within 8 min) or 240℃ (within 15 min), with a rest time of 2 min.

[0234] All experiments were conducted in a protected environment (rinsed with N2).

Claims

1. A method for manufacturing a fluoropolymer electrolyte membrane comprising a fluoropolymer hybrid organic / inorganic composite material for use in an electrochemical device, the method comprising the following steps: a) Dissolving i) at least one fluoropolymer in ii) at least one liquid medium, wherein i) at least one fluoropolymer comprises: - At least one first repeating unit derived from at least one olefinically unsaturated fluorinated monomer, and - Derived from at least one second repeating unit of at least one olefinic unsaturated monomer having at least one hydroxyl group; b) Reacting at least a portion of the hydroxyl groups of at least one fluoropolymer (i) with at least one metal compound having formula (I). X 4-m AY m (I) Where m is an integer from 1 to 3, A is a metal selected from the group consisting of Si, Ti, and Zr, Y is a hydrolyzable group, and X is a hydrocarbon group containing at least one isocyanate (-N=C=O) functional group, thereby providing a composition comprising at least one grafted fluoropolymer, the grafted fluoropolymer comprising at least one hydrogenated monomer having at least one side chain comprising the formula -OC(O)-NH-Z-AY m X 3-m The terminal groups, wherein m, Y, A and X have the same meaning as defined above and Z is a hydrocarbon group, optionally containing at least one -N=C=O functional group; c) reacting the end group having the formula -O-C(O)-NH-Z-AY m X 3-m iv) at least one metal compound having the formula (II) X' 4-m’ A'Y' m’ (II) Where m' is an integer from 1 to 4, A' is a metal selected from the group consisting of Si, Ti and Zr, Y' is a hydrolyzable group, optionally containing at least one functional group other than the -N=C=O group, and X' is a hydrocarbon group, thereby providing a composition comprising at least one fluoropolymer hybrid organic / inorganic composite material; as well as d) Process the composition from step c) into a polymer electrolyte membrane. The (ii) at least one liquid medium comprises at least one organic solvent and optionally at least one ionic liquid, wherein the organic solvent comprises: -Organic carbonates; - Aliphatic, alicyclic, or aromatic ether oxides; - Diol ether; - Diol ether ester; - Alcohols; - Ketones, wherein the ketones are selected from methyl isobutyl ketone, diisobutyl ketone, cyclohexanone or isophorone; - Straight-chain or cyclic esters; - Straight-chain or cyclic amides; and - Dimethyl sulfoxide; Its characteristic is that there is no drying step.

2. The method of claim 1, wherein, The organic carbonate is selected from at least one of ethylene carbonate, propylene carbonate, 4-methylene-1,3-dioxolane-2-one, 4,5-dimethylene-1,3-dioxolane-2-one, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, dipropyl carbonate, methyl propyl carbonate, methyl butyl carbonate, ethyl butyl carbonate, propyl butyl carbonate, dibutyl carbonate, di-tert-butyl carbonate, butyl carbonate, monofluorinated ethylene carbonate, difluorinated ethylene carbonate, monofluorinated propylene carbonate, difluorinated propylene carbonate, monofluorinated butyl carbonate, difluorinated butyl carbonate, 3,3,3-trifluoropropylene carbonate, dimethyl carbonate, difluorinated diethyl carbonate, methyl ethyl carbonate, difluorinated dipropyl carbonate, dibutyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, and mixtures thereof.

3. The method of claim 1, wherein, This organic carbonate is a mixture of ethylene carbonate and propylene carbonate.

4. The method of claim 1, wherein, The organic carbonate is a mixture of ethylene carbonate, propylene carbonate, and 4-fluoro-1,3-dioxolane-2-one.

5. The method of claim 1, wherein, The organic solvent also contains at least one sulfone compound selected from the following: tetramethylene sulfone (sulfolane), butadiene sulfone (sulfolene), pentamethylene sulfone, hexamethylene sulfone, thiazoline 1,1-dioxide, thiomorpholine 1,1-dioxide, dimethyl sulfone, diethyl sulfone, ethylmethyl sulfone, and mixtures thereof.

6. The method of claim 1, wherein, The organic solvent is a mixture of ethylene carbonate, propylene carbonate, 4-fluoro-1,3-dioxolane-2-one, and sulfolane.

7. The method of claim 1, wherein, The alcohols are selected from diacetone alcohol.

8. The method of any one of claims 1-7, wherein, This fluoropolymer electrolyte membrane does not contain metal salts.

9. The method of any one of claims 1-7, wherein, Step c) is performed at a temperature between 50°C and 100°C.

10. The method of any one of claims 1 to 7, wherein, The at least one first repeating unit is derived from vinylidene fluoride (VDF), chlorotrifluoroethylene (CTFE), hexafluoropropylene (HFP), tetrafluoroethylene (TFE), trifluoroethylene, and combinations thereof.

11. The method of any one of claims 1 to 7, wherein, The at least one second repeating unit is derived from a (meth)acrylate having at least one hydroxyl group.

12. The method of claim 11, wherein, The (meth)acrylate having at least one hydroxyl group includes 2-hydroxyethyl acrylate (HEA), 2-hydroxyethyl methacrylate, 2-hydroxymethyl acrylate, 2-hydroxymethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 6-hydroxyhexyl acrylate, 6-hydroxyhexyl methacrylate, 8-hydroxyoctyl acrylate, 8-hydroxyoctyl methacrylate, 2-hydroxyethylene glycol acrylate, 2-hydroxyethylene glycol methacrylate, 2-hydroxypropylene glycol acrylate, 2-hydroxypropylene glycol methacrylate, and mixtures thereof.

13. The method according to any one of claims 1 to 7, wherein, In the at least one metal compound having formula (I), X is a straight-chain or branched C1-C12 hydrocarbon group containing at least one -N=C=O functional group, and Y is OR, wherein R is a straight-chain or branched C1-C5 alkyl group.

14. The method of claim 13, wherein R is methyl or ethyl.

15. The method of claim 14, wherein, iii) At least one metal compound having formula (I) is selected from the group consisting of: methyl trimethoxysilyl isocyanate, methyl triethoxysilyl isocyanate, ethyl trimethoxysilyl isocyanate, ethyl triethoxysilyl isocyanate, propyl trimethoxysilyl isocyanate, propyl triethoxysilyl isocyanate, butyl trimethoxysilyl isocyanate, butyl triethoxysilyl isocyanate, pentyl trimethoxysilyl isocyanate, pentyl triethoxysilyl isocyanate, hexyl trimethoxysilyl isocyanate, hexyl triethoxysilyl isocyanate, and mixtures thereof.

16. The method of any one of claims 1 to 7, wherein, The iv) at least one metal compound having formula (II) comprises trimethoxysilane, triethoxysilane, tetramethoxysilane, tetraethoxysilane (TEOS), tetramethyl titanate, tetraethyl titanate, tetran-n-propyl titanate, tetraisopropyl titanate, tetran-n-butyl titanate, tetraisobutyl titanate, tetratert-butyl titanate, tetran-n-pentyl titanate, tetran-n-hexyl titanate, tetran-n-laurate titanate, tetraethyl zirconate, tetran-n-propyl zirconate, tetraisopropyl zirconate, tetran-n-butyl zirconate, tetrasec-butyl zirconate, tetratert-butyl zirconate, tetran-n-pentyl zirconate, tetratert-hexyl zirconate, tetran-n-heptyl zirconate, tetran-n-octyl zirconate, tetran-n-stearate zirconate, and mixtures thereof.

17. A polymer electrolyte membrane obtained by the method according to any one of claims 1 to 16.

18. An electrochemical device comprising a polymer electrolyte membrane obtained by any one of claims 1 to 16 between a positive electrode and a negative electrode.

19. The electrochemical device of claim 18, wherein, At least one of the positive and negative electrodes contains a metal salt.

20. The electrochemical device of claim 19, wherein, The metal salt is selected from transition metal salts, alkali metal salts, or alkaline earth metal salts.

21. The electrochemical device of claim 20, wherein, The metal salt is selected from Li salt, Na salt, K salt or Cs salt.

22. The electrochemical device of claim 21, wherein, The metal salt is selected from Li salts.

23. Use of the polymer electrolyte membrane obtained by the method according to any one of claims 1 to 16 in an electrochemical device.

24. The use according to claim 23, wherein, The electrochemical device is a secondary battery.

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