Polymer electrolyte, electrochemical single cell and battery comprising same, preparation method and application thereof

Abstract

The present invention relates to a polymer electrolyte comprising: i. At least one polymer; ii. At least one sulfonamide; and iii. At least one lithium salt; the electrolyte is also characterized in that it does not comprise an organic carbonate. The polymer electrolyte according to the invention preferably exists in the form of a gel. The invention also relates to an electrochemical cell or battery comprising said polymer electrolyte. A significant advantage of gel electrolytes is that it is characterized by improved thermal stability due to the absence of flammable liquids, such as organic carbonates, commonly involved in liquid electrolytes. The invention also relates to a method for producing the polymer electrolyte according to the invention and to a method for producing an electrochemical cell or battery comprising the polymer electrolyte according to the invention.

Description

Technical Field

[0001] The present invention relates to the field of polymer electrolytes, in particular polymer electrolytes in gel form, for electrochemical cells or batteries. The invention may have wide applications in energy storage and electronic devices. Background Art

[0002] Lithium metal batteries (LMBs) arguably represent an attractive technology for energy storage applications due to their high energy density and ultra-low redox potential. Commercial batteries primarily use liquid electrolytes (LEs) as ion transport media due to their high ionic conductivity and excellent wettability with electrodes and separators. Typical liquid electrolytes are organic carbonates and ethers, such as ethylene carbonate (EC), ethyl methyl carbonate (EMC), 1,2-dimethoxyethane (DME), etc. However, liquid electrolytes may be associated with potential safety issues and performance degradation arising from dendrite growth and cathode electrochemistry. The organic solvents of the liquid electrolytes are typically flammable solvents that may cause combustion (or even explosion) due to short circuits and thermal runaway caused by the growth of Li dendrites. To date, these issues have hindered the practical use of LMBs.

[0003] Solid electrolytes (eg, solid electrolytes made of polymers, ceramics, or mixtures thereof) and gel electrolytes can solve the above problems associated with using liquid electrolytes, however, their electrical conductivity is lower than that of established liquid electrolytes.

[0004] In particular, a solution to the low conductivity of gel polymer electrolytes (GPEs) is to introduce organic carbonates as liquid components or plasticizers that can help dissociate Li salts (or plasticize the polymer components). Although this improves ionic conductivity and the charge / discharge capacity of electrochemical cells, such organic carbonates can again affect battery stability and safety. Therefore, the design and manufacture of functional GPEs that enable the development of safe and durable LMBs requires additional work.

[0005] In some works, thermally stable polymers, such as fluorinated polymers, have been introduced to improve the thermal stability of GPE (JH Baik, DG Kim, JH Lee, S. Kim, DG Hong, JC Lee, J. Ind. Eng. Chem. 2018, 64, 453-460).

[0006] Another effective improvement involves the use of refractory additives (e.g., SiO2, Al2O3, etc.) that can inhibit exothermic reactions via chemical reactions. On the other hand, refractory additives may be detrimental to the ion-conducting pathways in the GPE, resulting in reduced ionic conductivity. Several sulfonamides have been used as components of liquid electrolytes, however, other organic carbonates are generally required to achieve stable electrochemical cycling.

[0007] Document EP3050872A1 relates to a solvent system comprising a solvent according to the general formula R 1 -SO2-NR2R3 fluorinated sulfonamide and electrolyte salt electrolyte solution; however, the document teaches that flammable carbonate solvents are essential for solving the corresponding technical problems (e.g., aluminum current collector corrosion) while maintaining high electrolyte conductivity ( Figure 1 ).

[0008] Dong, P. and colleagues disclosed a solid electrolyte containing poly (ethylene oxide), a lithium salt of bis (trifluoromethylsulfonyl) lithium (LiTFSI) and a non-fluorinated sulfonamide compound (DMMSA) in Deep Eutectic solvent-based polymer electrolyte for solid-state lithium metal batteries Journal of Energy Chemistry 2022, 70, 363-372. The authors have found that the oxygen atoms of the sulfonamide compound allow lithium cations to decouple from the ethylene oxide chains of the polymer, which improves the Li + migrate.

[0009] Document CA2197056A1 relates to a method comprising the formula R 1 R 2 -SO2-NR 3 R 4 An electrolyte composition of a non-fluorinated sulfonamide compound, wherein three R groups are methyl and the remaining groups are ethyl, or wherein one of the R groups is methoxyethyl and the remaining R groups are each independently methyl or ethyl. The disclosed composition may also include a non-proton polymer and / or a lithium salt. Xue and colleagues disclosed a polymer-free liquid electrolyte composition in “Ultra-high-voltage Ni-rich layered cathodes in practical Limetal batteries enabed bуаsulfonamide-based electrolyte” Nature Energy 2021, Vol. 6, 495-505, which includes LiTFSI and (N,N-dimethyl)trifluoromethylsulfonamide as lithium salts.

[0010] Qiao L. and co-workers disclosed in “Stable non-corrosive sulfonimide salt for 4-V-class lithium metal batteries” Nature Materials 2022, Vol. 21, 455-462 an electrolyte composition comprising a mixture of an organic carbonate and lithium (difluoromethyl)(trifluoromethyl)sulfonamide (LiDFTSI) as a lithium salt.

[0011] Therefore, there is a need in the art to develop new electrolyte systems, particularly gel electrolytes, that would overcome the thermal stability issues of prior art liquid electrolytes while simultaneously providing viable electrochemical performance for a wide range of applications. Summary of the Invention

[0012] The present invention relates to a polymer electrolyte, preferably in the form of a polymer gel electrolyte, comprising a sulfonamide, a (co)polymer and a lithium salt, and characterized in that it does not contain an organic carbonate. The inventors have found that such an electrolyte composition comprising a fluorinated sulfonamide retains a high discharge capacity and current efficiency after multiple charge / discharge cycles and, among other things, exhibits advantageous properties such as non-flammability and high stability with lithium metal.

[0013] Thus, a first aspect of the present invention relates to a polymer electrolyte comprising:

[0014] i. at least one polymer;

[0015] ii. at least one sulfonamide; and

[0016] iii. at least one lithium salt;

[0017] The electrolyte is further characterized in that it does not contain organic carbonates, and in that the at least one sulfonamide has the general formula I:

[0018]

[0019] in

[0020] -R 1 selected from F, linear or branched C1-C 12 Alkyl, linear or branched C2-C 12 Alkenyl, C3-C 12 Cycloalkyl and C6-C 12 Aryl,

[0021] as well as

[0022] -R 2 and R 3 independently selected from linear or branched C1-C 12 Alkyl; linear or branched C2-C 12 Alkenyl; C6-C4-alkenyl which may be substituted by one or more fluorine atoms 12 Aryl; and -CH2CH2O-(CH2CH2O) n -R, wherein R is H or methyl and n is an integer from 1 to 20, or R 2 and R 3 They may combine with each other to form a nitrogen-containing aliphatic ring.

[0023] A second aspect of the invention relates to an electrochemical cell or battery comprising the polymer electrolyte of the invention as defined above.

[0024] A third aspect of the present invention relates to a method for preparing the polymer electrolyte of the first aspect of the present invention, comprising the following steps:

[0025] (i) providing at least one lithium salt as defined in the first aspect of the present invention;

[0026] (ii) providing at least one sulfonamide as defined in the first aspect of the present invention and mixing it with the at least one lithium salt of step (i),

[0027] (iii) adding at least one polymer to the mixture obtained in step (ii); and,

[0028] (iv) Optionally, when the polymer electrolyte comprises at least one polymer having one or more cross-linkable functional groups, cross-linking the at least one polymer contained in the mixture resulting from step (iii).

[0029] Another aspect of the present invention relates to the use of the electrochemical cell or battery of the second aspect of the present invention in the following: electric motors; electric vehicles, including electric vehicles (EV), hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), etc.; light electric vehicles (electric carts), including electric bicycles (E-bikes) and electric scooters (E-scooters); electric golf carts; and power storage systems.

[0030] Finally, a fifth aspect of the present invention relates to a method for preparing an electrochemical cell or battery according to the second aspect of the present invention, comprising the steps of:

[0031] (i) providing a positive electrode for an electrochemical cell or battery;

[0032] (ii) providing a negative electrode for an electrochemical cell or battery;

[0033] (iii) providing the polymer electrolyte according to the first aspect of the present invention;

[0034] (iv) coating the surface of the positive electrode provided in step (i) and the surface of the negative electrode provided in step (ii) with the electrolyte provided in step (iii) in such a manner that the electrolyte is arranged between the positive electrode and the negative electrode so that lithium cations can flow from the positive electrode to the negative electrode, the surface of the positive electrode and the surface of the negative electrode being optionally covered with a film before coating with the electrolyte; and

[0035] (v) Optionally, when the polymer electrolyte contains at least one polymer having one or more cross-linkable functional groups, cross-linking the at least one polymer contained in the polymer electrolyte. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Specific discharge capacity (solid black dots) and Coulombic efficiency (open black dots) of Li°||NMC622 cells at 40°C versus cycle number.

[0037] Figure 2 Specific discharge capacity (solid black dots) and Coulombic efficiency (open black dots) of Li°||NMC622 cells at 25°C versus cycle number. DETAILED DESCRIPTION

[0038] Unless otherwise indicated, all terms used herein in this application should be understood to have their ordinary meanings as known in the art. Unless otherwise expressly set forth in a definition provides a broader definition, other more specific definitions of certain terms used in this application are set forth below and are intended to be uniformly applied throughout the specification and claims.

[0039] Throughout the specification and claims, the word "comprise" and variations thereof are not intended to exclude other technical features, additives, components, or steps. Furthermore, the word "comprising" encompasses "consisting of" and "consisting essentially of." Additional objects, advantages, and features of the present invention will become apparent to those skilled in the art after studying the specification or may be learned through practice of the invention.

[0040] Throughout the specification and claims, the terms "blend" and "mixture" will be used interchangeably.

[0041] For the purposes of the present invention, any range given includes both the lower and upper endpoints of the range. When a given range or value (e.g., temperature, time, molar ratio, volume ratio, etc.) is defined by the term "about" (i.e., there is a 5% variation around the indicated point), it should be considered approximate.

[0042] As mentioned above, a first aspect of the present invention relates to a polymer electrolyte comprising:

[0043] i. at least one polymer;

[0044] ii. at least one sulfonamide; and

[0045] iii. at least one lithium salt,

[0046] The polymer electrolyte is further characterized in that it does not contain organic carbonates,

[0047] And wherein the at least one sulfonamide has the general formula I:

[0048]

[0049] in

[0050] -R 1 selected from F, linear or branched C1-C 12 Alkyl, linear or branched C2-C 12 Alkenyl, C3-C 12 Cycloalkyl and C6-C 12 Aryl,

[0051] as well as

[0052] -R 2 and R 3 independently selected from linear or branched C1-C 12 Alkyl; linear or branched C2-C 12 Alkenyl; C which may be substituted by one or more fluorine atoms 6- C 12 Aryl; and -CH2CH2O-(CH2CH2O) n -R, wherein R is H or methyl and n is an integer from 1 to 20, or R 2 and R 3 They may combine with each other to form a nitrogen-containing aliphatic ring.

[0053] The present inventors have unexpectedly discovered that polymer electrolytes comprising a polymer, a sulfonamide of formula I and a lithium salt, but lacking an organic carbonate, are suitable for electrochemical applications (e.g., in lithium metal batteries) with the corresponding advantages of non-flammability and stability with lithium metal.

[0054] In a preferred embodiment, the polymer electrolyte of the first aspect of the invention is in the form of a gel. In the context of the present invention, a gel polymer electrolyte is understood to be a polymer network that is expanded or swollen throughout its volume by the presence of at least one sulfonamide and optionally a plasticizer (which is not a carbonate).

[0055] More embodiments of the first aspect of the present invention will be given below.

[0056] polymer

[0057] In the context of the present invention, the polymer contained in the polymer electrolyte of the present invention refers to a polymer material suitable for conducting ions (particularly lithium cations) via non-covalent interactions between the polymer chain and the ions. Suitable polymers for polymer electrolytes are known in the art and typically contain heteroatoms such as O, N, S or P in the repeating units of the polymer chain, which are suitable for interacting with lithium cations via the lone pairs of electrons of the heteroatoms.

[0058] The at least one polymer included in the polymer electrolyte (preferably polymer gel electrolyte) can be a homopolymer, a copolymer or a mixture thereof. In another embodiment, the polymer is in the form of a crosslinked polymer or in the form of a crosslinkable polymer composition. In another embodiment, the polymer can include one or more crosslinkable functional groups in its molecular formula.

[0059] In a particular embodiment, at least one polymer is selected from polyoxyalkylenes, such as polyethylene oxide (PEO) or polypropylene oxide (PPO); polyalkylene imines, such as polyethylene imine (PEI); polyalkylene sulfides, such as polyethylene sulfide (PEI); poly(ethylene glycol), poly(ethylene glycol) methacrylate (PEGMA), poly(ethylene glycol) methyl ether methacrylate, poly(ethylene glycol) dimethacrylate (PEGDMA), or blends thereof, or copolymers thereof, or crosslinked polymers thereof; polyphosphazenes, for example poly[bis(2-(2-methoxyethoxy)ethoxy]phosphazene (MEEP); polysiloxanes, for example poly(dimethylsiloxane) ) (PDMS); polyvinyl alcohol (PVA); polyvinylamine (PVAm); polyvinyl acetate (PVAc); polyvinyl halide, such as polyvinyl chloride (PVC) or polyvinylidene fluoride (PVdF); polyvinylidene fluoride-hexafluoropropylene (PVdF-HFP); polyacrylonitrile (PAN); poly(vinyl pyrrolidone) (PVP); poly(2-vinyl pyridine) (P2VP); poly(ε-caprolactone) (PCL); poly(maleimide), preferably poly(alkylene maleimide), more preferably poly(ethylene-alt-maleimide) (PEaMI); polyaniline (PANI); chitosan (CS); or any blend or any copolymer or any cross-linked polymer thereof. As in any of the above examples, the polymer may contain at least one cross-linkable functional group in its molecular formula, such as (meth)acrylate, epoxy, olefin, thiol, amino, hydroxyl, and other cross-linkable functional groups known in the art.

[0060] Preferably, at least one polymer is selected from:

[0061] - monoacrylates, diacrylates, triacrylates and tetraacrylates comprising polyethylene glycol, such as poly(ethylene glycol) methyl ether methacrylate, poly(ethylene glycol) methacrylate (PEGMA) or poly(ethylene glycol) dimethacrylate (PEGDMA), or any blend thereof, or any copolymer thereof or any cross-linked polymer thereof;

[0062] - polyalkyl acrylates, for example poly(butyl acrylate) (PBA), poly(ethyl acrylate) (PEA), poly(cyanoethyl acrylate) (PCEA); or any blend thereof, or any copolymer thereof or any crosslinked polymer thereof with trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA).

[0063] More preferably, the at least one polymer is selected from:

[0064] - poly(ethylene glycol) methyl ether methacrylate, poly(ethylene glycol) dimethacrylate (PEGDMA), or any blend, any copolymer, or any cross-linked polymer thereof;

[0065] - crosslinked polymers of butyl acrylate with trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA). Also contemplated are polymers that are mixtures of butyl acrylate with trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA), this mixture before crosslinking.

[0066] In another embodiment of the first aspect of the invention, the polymer is selected from the group consisting of poly(ethylene glycol) methyl ether methacrylate, poly(ethylene glycol) dimethacrylate (PEGDMA), blends, copolymers and cross-linked polymers thereof.

[0067] In another embodiment of the first aspect of the invention, the polymer is selected from poly(ethylene glycol) methyl ether methacrylate or a cross-linked polymer thereof, poly(ethylene glycol) dimethacrylate (PEGDMA) or a cross-linked polymer thereof, and a cross-linked polymer of poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glycol) dimethacrylate (PEGDMA).

[0068] In a specific embodiment, the polymer electrolyte comprises two polymers, which may be homopolymers, copolymers or mixtures thereof and are selected from the above list; preferably, the two polymers are poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glycol) dimethacrylate (PEGDMA) or cross-linked polymers thereof.

[0069] In a preferred embodiment of the first aspect of the invention, the polymer is selected from a mixture of poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glycol) dimethacrylate (PEGDMA); and a cross-linked polymer of poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glycol) dimethacrylate (PEGDMA).

[0070] The molecular weight of the at least one polymer is preferably from 100 g / mol to 10,000 g / mol. More preferably, the molecular weight of the at least one polymer is from 250 g / mol to 5,000 g / mol. Even more preferably, the molecular weight of the at least one polymer is from 500 g / mol to 1,000 g / mol. In certain embodiments, it is contemplated that the polymer is selected from poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glycol) dimethacrylate (PEGDMA), and the molecular weight of the polymer is from 500 g / mol to 1,000 g / mol; preferably 500 g / mol or 550 g / mol.

[0071] When at least one polymer contains one or more crosslinkable groups in its molecular formula, such as one or more crosslinkable acrylate groups, the polymer electrolyte (preferably a polymer gel electrolyte) optionally further contains an initiator for free radical polymerization, such as azoisobutyronitrile (AIBN). The initiator compound is preferably present in an amount of 0.1% to 1% by weight of the polymer electrolyte composition; more preferably, in an amount of 0.3% by weight of the polymer electrolyte composition.

[0072] In another embodiment of the first aspect of the invention, the polymer is a crosslinked polymer resulting from the further polymerization of a mixture of polymers comprising at least one crosslinkable functional group in their molecular formula, such as a crosslinked polymer resulting from the further free radical polymerization of a mixture of poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glycol) dimethacrylate (PEGDMA). In particular, the (meth)acrylate groups comprise C=C bonds in the (meth)acrylate moiety that can undergo further polymerization, resulting in crosslinking of the (meth)acrylate polymer chains.

[0073] In another embodiment, the polymer is a crosslinked polymer resulting from the polymerization of a mixture of monomers comprising at least one crosslinkable functional group in their molecular formula, such as a crosslinked polymer resulting from the free radical polymerization of a mixture of butyl acrylate with trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA).

[0074] The crosslinking process is promoted by a free radical polymerization initiator (e.g., AIBN) and heat (in the range of 50° C. to 100° C., more preferably at about 70° C.). Thus, in another embodiment, the polymer is also contemplated to be a mixture of poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glycol) dimethacrylate (PEGDMA), or a mixture of butyl acrylate and trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA), which is the mixture before crosslinking.

[0075] In another embodiment, when the polymer is a mixture of poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glycol) dimethacrylate (PEGDMA) or a cross-linked polymer thereof, it is preferred that the weight ratio of poly(ethylene glycol) methyl ether methacrylate to PEGDMA is from 50:1 to 1:1; more preferably from 10:1 to 2:1; even more preferably about 3:1.

[0076] In another embodiment, when the polymer is a mixture of butyl acrylate and trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA), or a cross-linked polymer thereof, the weight ratio of butyl acrylate to trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA) is from 50:1 to 1:1; more preferably from 10:1 to 2:1; even more preferably about 3:1.

[0077] Regardless of the chemical nature of the at least one polymer, its weight content in the polymer electrolyte can vary from 5 wt % to 85 wt %, preferably from 8 wt % to 60 wt %, even more preferably from 8 wt % to 20 wt %, relative to the total weight of the electrolyte composition. In a most preferred embodiment, the weight content of the at least one polymer is about 12 wt %, relative to the total weight of the electrolyte composition.

[0078] In one embodiment of the first aspect of the invention, the polymer is selected from poly(ethylene glycol) methyl ether methacrylate, poly(ethylene glycol) dimethacrylate (PEGDMA), blends, copolymers and cross-linked polymers thereof; and

[0079] - the polymer represents from 5% to 85% by weight of the composition; preferably, the polymer represents from 8% to 60% by weight of the composition; even more preferably, the polymer represents from 8% to 20% by weight of the composition; and / or

[0080] When the polymer is a mixture of poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glycol) dimethacrylate (PEGDMA) or a cross-linked polymer thereof, preferably, the weight ratio of PEGMA to PEGDA is from 50:1 to 1:1; more preferably from 10:1 to 2:1; even more preferably about 3:1.

[0081] Sulfonamide

[0082] The polymer electrolyte (preferably a polymer gel electrolyte) of the present invention comprises at least one sulfonamide. The term "sulfonamide" refers to an organic compound comprising a core functional group >NS(=O)2-, wherein the nitrogen atom is attached to two other organic moieties, and the sulfur atom is attached to another organic moiety. In one particular embodiment, the polymer electrolyte (preferably a polymer gel electrolyte) of the present invention comprises one sulfonamide; in another particular embodiment, it comprises two sulfonamides.

[0083] In a first aspect of the present invention, at least one sulfonamide has the following general formula I:

[0084]

[0085] in

[0086] R 1 selected from F, linear or branched C1-C 12 Alkyl, linear or branched C2-C 12 Alkenyl, C3-C 12 Cycloalkyl and C6-C 12 Aryl, and

[0087] R 2 and R 3 independently selected from linear or branched C1-C 12 Alkyl; linear or branched C2-C 12 Alkenyl; C6-C4-alkenyl which may be substituted by one or more fluorine atoms 12 Aryl; and CH2CH2O-(CH2CH2O) n -R, wherein R is H or methyl and n is an integer from 1 to 20; or R 2 and R 3 They may combine with each other to form a nitrogen-containing aliphatic ring.

[0088] As used herein, “C1-C 12 "Alkyl" refers to a branched or linear aliphatic carbon chain consisting of 1 to 12 carbon atoms. 12Illustrative examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, octyl, and the like. In preferred embodiments, the aliphatic chain may contain fewer carbon atoms, for example, 6 carbon atoms ("C1-C6 alkyl") or 3 carbon atoms ("C1-C3 alkyl"). The alkyl chain may be partially or fully fluorinated ("perfluorinated"), meaning that at least one but not all hydrogen atoms of any C-H bond are replaced by fluorine atoms, or all hydrogen atoms of any C-H bond are replaced by fluorine atoms, respectively.

[0089] As used in this article, “C2-C 12 "Alkenyl" refers to a linear or branched aliphatic group having 2 to 12 carbon atoms and having at least one C=C double bond. Such alkenyl groups include ethenyl (-CH=CH2), n-2-propenyl (allyl, -CH2CH=CH2), and the like.

[0090] As used in this article, “C3-C 12 "Cycloalkyl" refers to a monocyclic hydrocarbon group, a bicyclic hydrocarbon group, or a tricyclic hydrocarbon group having 3 to 12 carbon atoms. Typical C3-C 12 Cycloalkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, and cyclodecyl.

[0091] As used herein, “C6-C 12 "Aryl" refers to an aromatic hydrocarbon ring containing 6 to 12 carbon atoms, also as two fused rings, optionally substituted by an alkyl group as defined above, for example phenyl, α-naphthyl, β-naphthyl, m-methylphenyl, p-trifluoromethylphenyl, etc.

[0092] More particularly, R1 is selected from F, a linear or branched C1-C 12 Alkyl, linear or branched C2-C 12 alkenyl, and C3-C 12 Cycloalkyl.

[0093] Preferably, R1 is selected from F, a linear C1-C 12 Alkyl, and C3-C 12 Cycloalkyl.

[0094] In a preferred embodiment, when R1 is selected from a linear or branched C1-C 12 Alkyl, linear or branched C2-C 12 Alkenyl, and C3-C 12In the case of a cycloalkyl group, the substitution with a fluorine atom occurs at least on the carbon atom of R1 adjacent to the sulfur atom of the compound of formula (I).

[0095] Even more preferably, R1 is F or a linear C1-C 12 Alkyl, and even more preferably F or a linear C substituted by one or more fluorine atoms 1- C4 alkyl. In a more preferred embodiment, R1 is F or CF3. In a most preferred embodiment, R1 is F.

[0096] More particularly, R2 and R3 are independently selected from linear or branched C1-C 12 Alkyl, and linear or branched C2-C 12 Alkenyl.

[0097] Preferably, R2 and R3 are independently selected from linear C1-C 12 Alkyl, and linear C2-C 12 Even more preferably, R2 and R3 are independently selected from linear C1-C 10 Alkyl, and most preferably, R2 and R3 are independently selected from linear C1-C4 alkyl.

[0098] In one embodiment, R1 and R2 are the same. In another embodiment, R1 and R2 are different. In a most preferred embodiment, R1 = R2 = CH3.

[0099] In another embodiment, at least one sulfonamide has the general formula I shown above, wherein:

[0100] -R1 is selected from F, linear C1-C substituted by one or more fluorine atoms 12 Alkyl, and C3-C 12 cycloalkyl; and

[0101] - R2 and R3 are independently selected from linear C1-C 12 Alkyl, and linear C2-C 12 Alkenyl.

[0102] In another embodiment, at least one sulfonamide has the general formula I shown above, wherein:

[0103] - R1 is selected from F and linear C1-C4 alkyl substituted with one or more fluorine atoms; and

[0104] - R2 and R3 are linear C1-C4 alkyl groups which may be substituted by one or more fluorine atoms.

[0105] In another embodiment, the at least one sulfonamide is selected from at least one of the following structures:

[0106]

[0107] In a most preferred embodiment, the at least one sulfonamide is a sulfonamide wherein R1 is F and R2 = R3 = CH3.

[0108] In another most preferred embodiment, the at least one sulfonamide is a sulfonamide wherein R1 is CF3 and R2=R3=CH3.

[0109] The at least one sulfonamide is present in the polymer electrolyte, preferably the polymer gel electrolyte, in an amount that can vary from 5% to 85% by weight, preferably from 5% to 80% by weight, more preferably from 40% to 75% by weight. Even more preferably, the at least one sulfonamide is present in the gel electrolyte in an amount of about 70% by weight.

[0110] lithium salts

[0111] The at least one lithium salt contained in the polymer electrolyte (preferably the polymer gel electrolyte) may be an organic lithium salt, an inorganic lithium salt, or a combination thereof.

[0112] Specifically, the inorganic lithium salt may include, but is not limited to, LiClO4, LiNO3, LiBF4, LiAsF6, LiPF6, LiBF3Cl, and LiF.

[0113] Organic lithium salts may include, but are not limited to, LiN(SO2CF3)2, LiN(SO2CF3)(SO2CF2H), LiN(SO2F)2, LiN(SO2CF3)(SO2F), LiN(C2F5SO2)(SO2F), LiB(C2O4)2, LiBF2(C2O4), LiC(SO2CF3)3, LiPF3(C2F5)3, and LiCF3SO3.

[0114] In one embodiment, at least one lithium salt is selected from the group consisting of LiClO4, LiNO3, LiBF4, LiAsF6, LiPF6, LiBF3Cl, LiF, LiN(SO2CF3)2(LiTFSI), LiN(SO2CF3)(SO2CF2H), LiN(SO2F)2(LiFSI), LiN(SO2CF3)(SO2F), LiN(C2F5SO2)(SO2F), LiB(C2O4)2, LiBF2(C2O4), LiC(SO2CF3)3, LiPF3(C2F5)3, LiCF3SO3, and combinations thereof.

[0115] In another embodiment, the at least one lithium salt is selected from LiN(SO2CF3)2, LiN(SO2CF3)(SO2CF2H), LiN(SO2F)2, LiN(SO2CF3)(SO2F), LiB(C2O4)2, LiBF2(C2O4), LiC(SO2CF3)3, LiPF3(C2F5)3, LiCF3SO3, and LiNO3, or a combination thereof.

[0116] In a preferred embodiment, at least one lithium salt is an organic lithium salt, preferably selected from LiN(SO2CF3)(SO2CF2H), LiB(C2O4)2, LiN(SO2F)2, LiN(SO2CF3)2, LiN(SO2CF3)(SO2F) or a combination thereof.

[0117] In a preferred embodiment, only one lithium salt is contained in the polymer electrolyte, preferably the polymer gel electrolyte. In another embodiment, the lithium salt contained in the polymer electrolyte, preferably the polymer gel electrolyte, is LiN(SO2CF3)(SO2CF2H)((difluoromethanesulfonyl)(trifluoromethanesulfonyl)imide, also abbreviated as LiDFTFSI).

[0118] In another preferred embodiment, the polymer electrolyte of the first aspect of the present invention is a polymer electrolyte in which the at least one lithium salt is a combination of a first lithium salt suitable for use in a lithium metal battery and a second lithium salt other than the first lithium salt, the first lithium salt being selected from LiN(SO2CF3)(SO2CF2H), LiN(SO2CF3)(SO2F) and LiN(C2F5SO2)(SO2F). Preferably, the first lithium salt is LiN(SO2CF3)(SO2CF2H). In the preferred embodiment, the second lithium salt is selected from lithium perchlorate, lithium nitrate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium chlorotrifluoroborate, lithium fluoride, lithium oxide, lithium peroxide, a salt of formula LiN(SO2CF3)2, a salt of formula LiN(SO2F)2, a salt of formula LiN(SO2CF3)(SO2F), a salt of formula LiN(SO2C2F5)(SO2F), a salt of formula LiB(C2O4)2, a salt of formula LiBF2(C2O4), a salt of formula LiC(SO2CF3)3, a salt of formula LiPF3(C2F5)3, a salt of formula LiCF3SO3, and a mixture thereof. Preferably, the second lithium salt is selected from lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium chlorotrifluoroborate, a salt of formula LiB(C2O4)2, a salt of formula LiBF2(C2O4), a salt of formula LiPF3(C2F5)3, a salt of formula LiCF3SO3, and mixtures thereof. More preferably, the second lithium salt is a salt of formula LiB(C2O4)2 or a salt of formula LiBF2(C2O4).

[0119] In another preferred embodiment, the polymer electrolyte of the first aspect of the present invention is a polymer electrolyte in which the at least one lithium salt is a combination of a first lithium salt suitable for use in a lithium metal battery and a second lithium salt other than the first lithium salt, the first lithium salt being LiN(SO2CF3)(SO2CF2H), and the second lithium salt being selected from lithium perchlorate, lithium nitrate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium chlorotrifluoroborate, lithium fluoride, lithium oxide, lithium peroxide, a salt of formula LiN(SO2CF3)2, a salt of formula LiN(SO2F)2, a salt of formula LiN(SO2CF3)(SO2F), a salt of formula LiN(SO2C2F5)(SO2F), a salt of formula LiB(C2O4)2, a salt of formula LiBF2(C2O4), a salt of formula LiC(SO2CF3)3, a salt of formula LiPF3(C2F5)3, a salt of formula LiCF3SO3, and mixtures thereof.

[0120] In other embodiments, the second lithium salt is selected from lithium perchlorate, lithium nitrate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium chlorotrifluoroborate, lithium oxide, lithium peroxide, a salt of formula LiN(SO2CF3)2, a salt of formula LiN(SO2F)2, a salt of formula LiN(SO2CF3)(SO2F), a salt of formula LiN(SO2C2F5)(SO2F), a salt of formula LiB(C2O4)2, a salt of formula LiBF2(C2O4), a salt of formula LiC(SO2CF3)3, a salt of formula LiPF3(C2F5)3, a salt of formula LiCF3SO3, and a mixture thereof.

[0121] Preferably, the second lithium salt is selected from lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium chlorotrifluoroborate, a salt of the formula LiB(C2O4)2, a salt of the formula LiBF2(C2O4), a salt of the formula LiPF3(C2F5)3, a salt of the formula LiCF3SO3, and mixtures thereof. More preferably, the second lithium salt is a salt of the formula LiB(C2O4)2 or a salt of the formula LiBF2(C2O4). Even more preferably, the second lithium salt is a salt of the formula LiB(C2O4)2.

[0122] When the polymer electrolyte comprises a first lithium salt and a second lithium salt, as described above, the weight ratio of the first lithium salt to the second lithium salt is 1:1 to 4:1; preferably, it is 1:1 to 3:1, and more preferably, it is 1:1 to 2:1. In an even more preferred embodiment of the first aspect of the invention, the weight ratio of the first lithium salt to the second lithium salt is about 112:81. In an even more preferred embodiment of the first aspect of the invention, the weight ratio of the first lithium salt to the second lithium salt is about 114:82. In an even more preferred embodiment of the first aspect of the invention, the weight ratio of the first lithium salt to the second lithium salt is about 95:51.

[0123] The at least one lithium salt contained in the electrolyte may vary from 10% to 90% by weight, preferably from 10% to 50% by weight, even more preferably from 10% to 30% by weight, and even more preferably from 15% to 25% by weight, relative to the total weight of the polymer electrolyte (preferably a polymer gel electrolyte). Most preferably, the at least one lithium salt contained in the electrolyte is about 18% by weight relative to the total weight of the electrolyte.

[0124] Organic carbonates

[0125] As mentioned above, the polymer electrolyte (preferably polymer gel electrolyte) of the present invention is also characterized in that it does not contain organic carbonates. For the purposes of the present invention, any carbonate O=C(-O) containing an organic cyclic or linear chain having at least C atoms and H atoms is -) 2 must be considered as an organic carbonate and is therefore excluded from the polymer electrolyte (preferably polymer gel electrolyte) of the present invention. Organic carbonates are preferably liquid at room temperature. As an example, the definition of organic carbonate includes cyclic alkylene carbonates (ethylene carbonate, propylene carbonate, butylene carbonate, etc.) and di(hydrocarbyl) carbonates, such as dialkyl carbonates, diaryl carbonates, alkylaryl carbonates or mixtures thereof, even though this list is non-limiting.

[0126] Substituted derivatives of the aforementioned organic carbonates are also excluded from the polymer electrolyte (preferably polymer gel electrolyte) of the present invention. One or more substituents may be present on the alkylene, alkyl or aryl moieties. Non-limiting examples of substituents include halogen, alkoxy, hydroxyl, nitrogen substituents, phosphorus substituents, sulfur substituents and the like.

[0127] plasticizers

[0128] In a specific embodiment, the polymer electrolyte of the first aspect of the present invention further comprises a plasticizer. In the context of the present invention, the term "plasticizer" refers to a substance suitable for softening the polymer, swelling the polymer, and / or dissolving the lithium salt of the polymer electrolyte. As described above, the polymer electrolyte of the present invention is characterized in that it does not contain a carbonate, and therefore the plasticizer cannot be a carbonate. Examples of plasticizers are known in the art and include, among others, organic solvents and compounds such as dimethoxyethane (DME), 1,2-diethoxyethane (DEE), 1,3-dioxolane (DOL), diethylene glycol dimethyl ether (DEGDME), triethylene glycol dimethyl ether (G3), tetraethylene glycol dimethyl ether (TEGDME), poly(ethylene glycol) dimethyl ether (PEGDME), tetrahydropyran (THP), γ-butyrolactone, tetrahydrofuran (THF), 2-methyltetrahydrofuran, diethyl ether, methyl tert-butyl ether, succinonitrile (SN), glutaronitrile (GN), adiponitrile (AN), N,N-dimethylsulfamoyl fluoride (FSA), N,N-dimethyltrifluoromethane-sulfonamide (TFSA), and any mixtures thereof.

[0129] Other embodiments of polymer electrolytes

[0130] In one embodiment of the present invention, the polymer electrolyte (preferably a gel polymer electrolyte) consists of:

[0131] i. two polymers in the form of a blend, copolymer or cross-linked polymer thereof;

[0132] ii. a sulfonamide; and

[0133] iii. a lithium salt;

[0134] The electrolyte is further characterized in that it contains no organic carbonates.

[0135] In one embodiment, the gel electrolyte of the present invention comprises:

[0136] i. at least one polymer selected from the group consisting of:

[0137] -polyoxyalkylenes;

[0138] -polyalkyleneimines;

[0139] -polyalkylene sulfide;

[0140] - poly(meth)acrylates or crosslinked polymers thereof with trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA);

[0141] - polyethylene glycol, optionally comprising one or more crosslinkable groups;

[0142] - polyphosphazene;

[0143] - polysiloxanes;

[0144] -polyvinyl alcohol (PVA);

[0145] -polyvinylamine (PVAm);

[0146] - polyvinyl acetate (PVAc);

[0147] - polyvinyl halides;

[0148] - polyacrylonitrile (PAN);

[0149] - poly(vinylpyrrolidone) (PVP);

[0150] -poly(2-vinylpyridine) (P2VP);

[0151] -poly(ε-caprolactone) (PCL);

[0152] -poly(maleimide);

[0153] -polyaniline (PANI);

[0154] - Chitosan (CS); or

[0155] - any copolymer or any mixture or any cross-linked polymer thereof;

[0156] ii. at least one sulfonamide having the general formula:

[0157] in

[0158] -R1 selected from F, linear or branched C1-C 12 Alkyl, linear or branched C2-C 12 Alkenyl, C3-C 12 Cycloalkyl and C6-C 12 Aryl,

[0159] as well as

[0160] -R 2 and R 3 independently selected from linear or branched C1-C 12 Alkyl; linear or branched C2-C 12 Alkenyl; C6-C4-alkenyl which may be substituted by one or more fluorine atoms 12 Aryl; and CH2CH2O-(CH2CH2O) n -R, wherein R is H or methyl and n is an integer from 1 to 20; or R 2 and R 3 may combine with each other to form a nitrogen-containing aliphatic ring; and

[0161] iii. an organic lithium salt or an inorganic lithium salt selected from LiClO4, LiNO3, LiBF4, LiAsF6, LiPF6, LiBF3Cl, LiF, LiN(SO2CF3)2, LiN(SO2CF3)(SO2CF2H), LiN(SO2F)2, LiN(SO2CF3)(SO2F), LiN(C2F5SO2)(SO2F), LiB(C2O4)2, LiBF2(C2O4), LiC(SO2CF3)3, LiPF3(C2F5)3, LiCF3SO3 or a combination thereof.

[0162] In a particular embodiment of the latter:

[0163] - the at least one polymer represents 5% to 85% by weight relative to the total weight of the electrolyte composition, preferably 8% to 60% by weight, even more preferably 8% to 20% by weight, even more preferably about 12% by weight relative to the total weight of the gel electrolyte;

[0164] - the at least one sulfonamide represents 5% to 85% by weight relative to the total weight of the electrolyte, preferably 5% to 80% by weight relative to the total weight of the electrolyte, more preferably 40% to 75% by weight relative to the total weight of the electrolyte; even more preferably about 70% by weight relative to the total weight of the electrolyte; and / or

[0165] - the at least one lithium salt represents 10% to 90% by weight relative to the total weight of the electrolyte, preferably the at least one lithium salt represents 10% to 50% by weight relative to the total weight of the electrolyte, even more preferably the at least one lithium salt represents 10% to 30% by weight relative to the total weight of the electrolyte, even more preferably the at least one lithium salt represents about 18% by weight relative to the total weight of the electrolyte.

[0166] In other embodiments, the polymer electrolyte comprises:

[0167] i. at least one polymer selected from poly(ethylene glycol) methyl ether methacrylate, poly(ethylene glycol) methacrylate (PEGMA), poly(ethylene glycol) dimethacrylate (PEGDMA), or any blend thereof, or any copolymer thereof, or any cross-linked polymer thereof; and polyalkyl acrylates, such as poly(butyl acrylate) (PBA), poly(ethyl acrylate) (PEA), poly(cyanoethyl acrylate) (PCEA), or any blend thereof, or any copolymer thereof, or any cross-linked polymer thereof with trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA).

[0168] ii. at least one sulfonamide of formula I,

[0169] in

[0170] - R1 is selected from F or a linear C1-C4 alkyl group substituted with one or more fluorine atoms; and

[0171] - R2 and R3 are linear C1-C4 alkyl groups; and

[0172] iii. at least an organic lithium salt selected from the group consisting of LiN(SO2CF3)(SO2CF2H), LiB(C2O4)2, LiN(SO2F)2, LiN(SO2CF3)2, LiN(SO2CF3)(SO2F) and combinations thereof; wherein preferably, the lithium salt is LiN(SO2CF3)(SO2CF2H).

[0173] In other embodiments, the polymer electrolyte consists of:

[0174] i. at least one polymer selected from poly(ethylene glycol) methyl ether methacrylate, poly(ethylene glycol) dimethacrylate (PEGDMA), or any blend thereof, or any copolymer thereof, or any cross-linked polymer thereof; and cross-linked polymers of butyl acrylate with trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA);

[0175] ii. a sulfonamide of formula I,

[0176] in

[0177] - R1 is selected from F or a linear C1-C4 alkyl group substituted with one or more fluorine atoms; and

[0178] - R2 and R3 are linear C1-C4 alkyl groups; and

[0179] iii. an organic lithium salt selected from LiN(SO2CF3)(SO2CF2H), LiB(C2O4)2, LiN(SO2F)2, LiN(SO2CF3)2, LiN(SO2CF3)(SO2F) or a combination thereof; preferably, the lithium salt is LiN(SO2CF3)(SO2CF2H).

[0180] In other embodiments, the polymer electrolyte consists of:

[0181] i. at least one polymer selected from poly(ethylene glycol) methyl ether methacrylate, poly(ethylene glycol) dimethacrylate (PEGDMA), or any blend thereof, or any copolymer thereof, or any cross-linked polymer thereof; and cross-linked polymers of butyl acrylate with trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA);

[0182] ii. a sulfonamide of formula I,

[0183] in

[0184] - R1 is selected from F or a linear C1-C4 alkyl group substituted with one or more fluorine atoms; and

[0185] - R2 and R3 are linear C1-C4 alkyl groups; and

[0186] iii. at least one lithium salt is a combination of a first lithium salt suitable for a lithium metal battery and a second lithium salt other than the first lithium salt, wherein the first lithium salt is selected from LiN(SO2CF3)(SO2CF2H), LiN(SO2CF3)(SO2F) and LiN(C2F5SO2)(SO2F); preferably, the first lithium salt is LiN(SO2CF3)(SO2CF2H).

[0187] In other embodiments, the polymer electrolyte consists of:

[0188] i. at least one polymer selected from poly(ethylene glycol) methyl ether methacrylate, poly(ethylene glycol) dimethacrylate (PEGDMA), or any blend thereof, or any copolymer thereof, or any cross-linked polymer thereof; and cross-linked polymers of butyl acrylate with trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA);

[0189] ii. a sulfonamide of formula I,

[0190] in

[0191] - R1 is selected from F or a linear C1-C4 alkyl group substituted with one or more fluorine atoms; and

[0192] - R2 and R3 are linear C1-C4 alkyl groups; and

[0193] iii. at least one lithium salt is a combination of a first lithium salt and a second lithium salt, wherein the first lithium salt is selected from LiN(SO2CF3)(SO2CF2H), LiN(SO2CF3)(SO2F) and LiN(C2F5SO2)(SO2F), and the second lithium salt is selected from lithium perchlorate, lithium nitrate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium chlorotrifluoroborate, lithium fluoride, lithium oxide, lithium peroxide, a salt of formula LiN(SO2CF3)2, a salt of formula LiN(SO2F)2, a salt of formula LiN(S O2CF3)(SO2F), salts of formula LiN(SO2C2F5)(SO2F), salts of formula LiB(C2O4)2, salts of formula LiBF2(C2O4), salts of formula LiC(SO2CF3)3, salts of formula LiPF3(C2F5)3, salts of formula LiCF3SO3 and mixtures thereof; preferably, the first lithium salt is LiN(SO2CF3)(SO2CF2H) and / or the second lithium salt is a salt of formula LiB(C2O4)2 or a salt of formula LiBF2(C2O4).

[0194] In other embodiments, the polymer electrolyte consists of:

[0195] i. at least one polymer selected from poly(ethylene glycol) methyl ether methacrylate, poly(ethylene glycol) dimethacrylate (PEGDMA), or any blend thereof, or any copolymer thereof, or any cross-linked polymer thereof;

[0196] ii. a sulfonamide of formula I,

[0197] in

[0198] - R1 is selected from F or a linear C1-C4 alkyl group substituted with one or more fluorine atoms; and

[0199] - R2 and R3 are linear C1-C4 alkyl groups; and

[0200] iii. an organic lithium salt selected from LiN(SO2CF3)(SO2CF2H), LiB(C2O4)2, LiN(SO2F)2, LiN(SO2CF3)2, LiN(SO2CF3)(SO2F) or a combination thereof; preferably, the lithium salt is LiN(SO2CF3)(SO2CF2H).

[0201] Specifically, in the latter, the weight ratio between poly(ethylene glycol) methyl ether methacrylate and PEGDMA is 50:1 to 1:1, more preferably 10:1 to 2:1, even more preferably about 3:1; more specifically, the weight ratio between polymer:sulfonamide:lithium salt is about 70:12:18.

[0202] In other embodiments, the polymer electrolyte consists of:

[0203] i. at least one polymer selected from poly(ethylene glycol) methyl ether methacrylate, poly(ethylene glycol) dimethacrylate (PEGDMA), or any blend thereof, or any copolymer thereof, or any cross-linked polymer thereof;

[0204] ii. a sulfonamide of formula I,

[0205] in

[0206] - R1 is selected from F or a linear C1-C4 alkyl group substituted with one or more fluorine atoms; and

[0207] - R2 and R3 are linear C1-C4 alkyl groups; and

[0208] iii. at least one lithium salt is a combination of a first lithium salt suitable for a lithium metal battery and a second lithium salt other than the first lithium salt, wherein the first lithium salt is selected from LiN(SO2CF3)(SO2CF2H), LiN(SO2CF3)(SO2F) and LiN(C2F5SO2)(SO2F); preferably, the first lithium salt is LiN(SO2CF3)(SO2CF2H).

[0209] In other embodiments, the polymer electrolyte consists of:

[0210] i. at least one polymer selected from poly(ethylene glycol) methyl ether methacrylate, poly(ethylene glycol) dimethacrylate (PEGDMA), or any blend thereof, or any copolymer thereof, or any cross-linked polymer thereof;

[0211] ii. a sulfonamide of formula I,

[0212] in

[0213] - R1 is selected from F or a linear C1-C4 alkyl group substituted with one or more fluorine atoms; and

[0214] - R2 and R3 are linear C1-C4 alkyl groups; and

[0215] iii. at least one lithium salt is a combination of a first lithium salt and a second lithium salt, wherein the first lithium salt is selected from LiN(SO2CF3)(SO2CF2H), LiN(SO2CF3)(SO2F) and LiN(C2F5SO2)(SO2F), and the second lithium salt is selected from lithium perchlorate, lithium nitrate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium chlorotrifluoroborate, lithium fluoride, lithium oxide, lithium peroxide, a salt of formula LiN(SO2CF3)2, a salt of formula LiN(SO2F)2, a salt of formula LiN(S O2CF3)(SO2F), salts of formula LiN(SO2C2F5)(SO2F), salts of formula LiB(C2O4)2, salts of formula LiBF2(C2O4), salts of formula LiC(SO2CF3)3, salts of formula LiPF3(C2F5)3, salts of formula LiCF3SO3 and mixtures thereof; preferably, the first lithium salt is LiN(SO2CF3)(SO2CF2H) and / or the second lithium salt is a salt of formula LiB(C2O4)2 or a salt of formula LiBF2(C2O4).

[0216] electrochemistry monomer Batteries and batteries

[0217] The polymer electrolyte (preferably a polymer gel electrolyte) of the first aspect of the present invention is particularly useful in electrochemical devices, such as electrochemical cells or batteries, particularly secondary electrochemical cells or batteries in which the battery reaction is reversible. Accordingly, the second aspect of the present invention relates to an electrochemical cell or battery comprising the polymer electrolyte according to the first aspect of the present invention.

[0218] In a preferred embodiment, the second aspect of the invention relates to an electrochemical cell or battery comprising a polymer electrolyte according to any embodiment, preferred or particular embodiment of the first aspect of the invention defined above.

[0219] In a preferred embodiment, the second aspect of the invention relates to a lithium metal battery comprising a polymer electrolyte according to any embodiment of the first aspect of the invention defined above. A lithium metal battery is a battery characterized in that it comprises a negative electrode consisting essentially of metallic lithium.

[0220] In another preferred embodiment, the second aspect of the present invention relates to a lithium metal battery comprising a positive electrode, wherein the positive electrode material is selected from lithium manganese oxide, lithium nickel oxide, lithium nickel manganese cobalt oxide, lithium nickel manganese oxide, lithium manganese cobalt oxide, lithium copper oxide, lithium copper sulfide, lithium iron phosphate, lithium iron sulfide, lithium manganese iron phosphate and lithium nickel cobalt aluminum oxide.

[0221] In another preferred embodiment, the second aspect of the present invention relates to a lithium metal battery comprising a positive electrode, wherein the positive electrode material is lithium nickel manganese cobalt oxide, such as LiNi 0.6 Mn 0.2 Co 0.2 O2 (NMC622). Specifically, the lithium nickel manganese cobalt oxide positive electrode may further include other additives. In a specific embodiment, the positive electrode comprises NMC622, conductive carbon, and a polymer binder. Preferably, the positive electrode comprises NMC622, carbon black as the conductive carbon, and polyvinylidene fluoride (PVdF) as the polymer binder. Preferably, the weight ratio of NMC622:conductive carbon:polymer binder is 90:5:5.

[0222] In another preferred embodiment, the second aspect of the present invention relates to a lithium metal battery comprising a separator membrane (e.g., a polypropylene membrane, preferably a microporous polypropylene), the separator membrane being arranged between at least one electrode and a polymer electrolyte in such a configuration that lithium cations can flow through the membrane between the electrolyte and the surface of the at least one electrode. In a specific embodiment, the thickness of the separator membrane is 1 μm to 50 μm, preferably 15 μm to 35 μm, more preferably about 25 μm. The porosity of the separator membrane may also vary within a certain range, in particular, the average pore diameter is 0.001 μm to 0.100 μm, preferably 0.020 μm to 0.080 μm, more preferably about 0.064 μm.

[0223] In another preferred embodiment, the second aspect of the present invention relates to a lithium metal battery having a charge retention capacity of at least 70%, preferably at least 75%, and more preferably at least 80% after 100 charge cycles. In a specific embodiment, the first cycle is applied at a current of C / 20, the next three cycles are applied at a current of C / 10, and the remaining cycles are applied at C / 5 at a temperature of 25°C. In another embodiment, the voltage is 3.00V to 4.25V.

[0224] In another preferred embodiment, the second aspect of the present invention relates to a lithium metal battery, wherein the positive electrode material is lithium nickel manganese cobalt oxide, and the polymer electrolyte (preferably a polymer gel electrolyte) is a polymer electrolyte wherein:

[0225] - at least one sulfonamide is FS(O)2(CH3)2 and is contained in the polymer electrolyte composition in an amount that can vary from 5% to 85% by weight, preferably from 5% to 80% by weight, more preferably from 40% to 75% by weight, and even more preferably in an amount of about 70% by weight relative to the total weight of the composition;

[0226] - at least one lithium salt is LiDFTFSI and is contained in the polymer electrolyte composition in an amount of 10% to 90% by weight relative to the total weight of the electrolyte composition; preferably, in an amount of 10% to 30% by weight relative to the total weight of the electrolyte composition; even more preferably, in an amount of about 18% by weight relative to the total weight of the electrolyte composition; and / or

[0227] at least one polymer selected from poly(ethylene glycol) methyl ether methacrylate or a cross-linked polymer thereof, poly(ethylene glycol) dimethacrylate (PEGDMA) or a cross-linked copolymer thereof, a cross-linked polymer of poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glycol) dimethacrylate (PEGDMA), a cross-linked polymer of butyl acrylate and trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA);

[0228] - the polymer represents 5% to 85% by weight relative to the total weight of the electrolyte composition; preferably, the polymer represents 8% to 60% by weight relative to the total weight of the electrolyte composition; more preferably, the polymer represents 8% to 20% by weight relative to the total weight of the electrolyte composition; even more preferably, the polymer represents about 12% by weight relative to the total weight of the electrolyte composition, and wherein:

[0229] When the polymer is a mixture of poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glycol) dimethacrylate (PEGDMA) or a cross-linked polymer thereof, or a cross-linked polymer of butyl acrylate and trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA), preferably, the weight ratio thereof is from 50:1 to 1:1; more preferably from 10:1 to 2:1; even more preferably about 3:1; and / or

[0230] When the polymer is selected from poly(ethylene glycol) methyl ether methacrylate, poly(ethylene glycol) dimethacrylate (PEGDMA), and copolymers or mixtures thereof, or a mixture of butyl acrylate with trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA), the polymer electrolyte composition further comprises an initiator for free radical polymerization, such as azoisobutyronitrile (AIBN).

[0231] In another preferred embodiment, the second aspect of the present invention relates to a lithium metal battery, wherein the positive electrode material is lithium nickel manganese cobalt oxide, and the polymer electrolyte (preferably a polymer gel electrolyte) is a polymer electrolyte wherein:

[0232] - at least one sulfonamide is FS(O)2(CH3)2 and is contained in the polymer electrolyte composition in an amount that can vary from 5% to 85% by weight, preferably from 5% to 80% by weight, more preferably from 40% to 75% by weight, and even more preferably in an amount of about 70% by weight relative to the total weight of the composition;

[0233] - at least one lithium salt is a combination of a first lithium salt and a second lithium salt, the first lithium salt being LiN(SO2CF3)(SO2CF2H) and the second lithium salt being a salt of the formula LiB(C2O4)2 or a salt of the formula LiBF2(C2O4); and the combination is contained in the polymer electrolyte composition in an amount of 10% to 90% by weight relative to the total weight of the electrolyte composition; preferably, in an amount of 10% to 30% by weight relative to the total weight of the electrolyte composition; and / or

[0234] at least one polymer selected from poly(ethylene glycol) methyl ether methacrylate or a cross-linked polymer thereof, poly(ethylene glycol) dimethacrylate (PEGDMA) or a cross-linked copolymer thereof, a cross-linked polymer of poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glycol) dimethacrylate (PEGDMA), a cross-linked polymer of butyl acrylate and trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA);

[0235] - the polymer represents 5% to 85% by weight relative to the total weight of the electrolyte composition; preferably, the polymer represents 8% to 60% by weight relative to the total weight of the electrolyte composition; more preferably, the polymer represents 8% to 20% by weight relative to the total weight of the electrolyte composition; even more preferably, the polymer represents about 12% by weight relative to the total weight of the electrolyte composition, and wherein:

[0236] When the polymer is a mixture of poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glycol) dimethacrylate (PEGDMA) or a cross-linked polymer thereof, or a cross-linked polymer of butyl acrylate and trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA), preferably, the weight ratio thereof is from 50:1 to 1:1; more preferably from 10:1 to 2:1; even more preferably about 3:1; and / or

[0237] When the polymer is selected from poly(ethylene glycol) methyl ether methacrylate, poly(ethylene glycol) dimethacrylate (PEGDMA), and copolymers or mixtures thereof, or a mixture of butyl acrylate with trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA), the polymer electrolyte composition further comprises an initiator for free radical polymerization, such as azoisobutyronitrile (AIBN).

[0238] The electrochemical cells or batteries of the present invention can be applied to various electronic devices, which may include but are not limited to: electric motors; electric vehicles, including electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), etc.; light electric vehicles, including electric bicycles (E-bikes) and electric scooters (E-scooters); electric golf carts; power storage systems; and the like.

[0239] For preparing polymer electrolyte and electrochemical method comprising the same monomer Battery or battery method

[0240] As defined above, a third aspect of the present invention relates to a method for preparing a polymer electrolyte (preferably a polymer gel electrolyte) according to the first aspect of the present invention, comprising the following steps:

[0241] (i) providing at least one lithium salt as defined in the first aspect of the present invention;

[0242] (ii) mixing at least one sulfonamide as defined in the first aspect of the invention with the at least one lithium salt of step (i);

[0243] (iii) adding at least one polymer as defined above to the mixture obtained in step (ii); and,

[0244] (iv) Optionally, when the polymer comprises one or more cross-linkable functional groups, cross-linking the polymer contained in the mixture resulting from step (iii).

[0245] All steps of the above method can be performed using pure components of the polymer electrolyte (eg, as pure solids or liquids), or alternatively, the components can be dissolved in a solvent prior to performing a given step.

[0246] In a preferred embodiment, steps (i) and (ii) are carried out by using pure components (lithium salt and sulfonamide).

[0247] In another embodiment, step (iii) is performed by first adding a solvent to the mixture obtained from step (ii) and then adding the at least one polymer. In another embodiment, step (iii) is performed by adding neat the at least one polymer to the mixture obtained from step (ii).

[0248] Preferably, the mixture obtained by step (iii) is stirred for a certain time to ensure that a uniform solution is obtained (i.e., there is no suspended matter). Stirring is carried out magnetically at 100 rpm, 200 rpm, 300 rpm, 400 rpm, 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, or 1000 rpm; preferably, stirring is carried out in the range of 100 rpm to 500 rpm, even more preferably at about 300 rpm. In addition, the mixture from step (iii) is stirred for at least 5 minutes, at least 15 minutes, at least 30 minutes, at least 1 hour, at least 2 hours, at least 4 hours, at least 6 hours, at least 12 hours, or at least 1 day; preferably, the mixture from step (iii) is stirred for 1 to 4 hours, more preferably 2 hours.

[0249] All steps of the above process are carried out at a temperature of 10°C to 30°C, preferably 15°C to 25°C, even more preferably 20°C to 25°C.

[0250] Step (iv) is optionally carried out when the polymer contains one or more crosslinkable functional groups, preferably such groups are carbon-carbon double bonds, more preferably carbon-carbon double bonds of (meth)acrylates. In particular, when the polymer used for the electrolyte is poly(ethylene glycol) methyl ether methacrylate, poly(ethylene glycol) dimethacrylate (PEGDMA), or a blend or copolymer thereof, or a blend of butyl acrylate with trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA), the optional crosslinking step (iv) is preferably carried out by free radical polymerization, the reaction preferably being initiated with azoisobutyronitrile (AIBN). Preferably, after the addition of AIBN, the mixture thus obtained is stirred to ensure the homogeneity of the solution. Other crosslinking reactions are known in the art and will become apparent to the skilled person.

[0251] A method for preparing an electrochemical cell or battery according to the second aspect of the invention is another aspect of the invention. The method will be apparent to the skilled person using common knowledge. In a preferred embodiment, the method comprises the following steps:

[0252] (i) providing a positive electrode for an electrochemical cell or battery;

[0253] (ii) providing a negative electrode for an electrochemical cell or battery;

[0254] (iii) providing a polymer electrolyte, preferably a gel polymer electrolyte, as defined in any preferred or specific embodiment of the first aspect of the present invention;

[0255] (iv) coating the surface of the positive electrode provided in step (i) and the surface of the negative electrode provided in step (ii) with the electrolyte provided in step (iii) in such a manner that the electrolyte is arranged between the positive electrode and the negative electrode so that lithium cations can flow from the positive electrode to the negative electrode, the surfaces being optionally covered with a film before coating with the electrolyte; and

[0256] (v) Optionally, when the polymer electrolyte contains a polymer having one or more cross-linkable functional groups, cross-linking the polymer contained in the polymer electrolyte.

[0257] In a particular embodiment, the coating step (iv) is carried out by a casting technique as known in the art. As described above, such a surface may be covered with a film that acts as a separator; in the case where both the positive electrode surface and the negative electrode surface are covered with a film, such a film may be the same or different for each surface. Preferably, such a film is a polymer film separator, more preferably a polypropylene film separator.

[0258] In a preferred embodiment, the crosslinking step (v) involves free radical polymerization of (meth)acrylate groups as crosslinkable functional groups. Preferably, the (meth)acrylate groups are contained in a poly(ethylene glycol) compound, such as poly(ethylene glycol) methyl ether methacrylate or poly(ethylene glycol) dimethacrylate (PEGDMA), or in a (meth)acrylate monomer, such as methyl acrylate, ethyl acrylate, or butyl acrylate, pentaerythritol tetraacrylate (PETA), or trimethylolpropane triacrylate (ETPTA). Crosslinking is initiated by a free radical polymerization initiator, such as AIBN, under temperature and pressure conditions for a reaction time readily deducible by the skilled artisan. In a preferred embodiment, the crosslinking step is carried out at 50°C, 60°C, 70°C, 80°C, 90°C, or 100°C, preferably in the range of 50°C to 100°C, and more preferably at approximately 70°C. The reaction time of the cross-linking step will be known to the skilled person and depends on the groups undergoing cross-linking; it will be at least 1 hour, at least 2 hours, at least 4 hours, at least 6 hours, at least 8 hours, at least 10 hours, at least 12 hours, at least 24 hours; preferably, the reaction time will be about 12 hours.

[0259] Preferred materials for use in preparing electrochemical cells or batteries are as defined in preferred and particular embodiments of the second aspect of the invention.

[0260] The optional cross-linking step (v) can be carried out before or after step (iv). However, it is preferably carried out after step (iv) as this facilitates maximum contact surface between the electrolyte and the electrodes.

[0261] Example

[0262] The following examples are intended to illustrate but not to limit the disclosed embodiments.

[0263] List of abbreviations

[0264] LiDFTFSI: (difluoromethanesulfonyl)(trifluoromethanesulfonyl)imide lithium salt

[0265] LiBOB: lithium bis(oxalato)borate

[0266] PEGDMA: poly(ethylene glycol) dimethacrylate with Mn = 550 g / mol

[0267] AIBN: Azoisobutyronitrile

[0268] rpm: revolutions per minute

[0269] RT: room temperature

[0270] Reagents and starting materials

[0271] The following chemicals were purchased from Sigma-Aldrich and pretreated as follows:

[0272] Poly(ethylene glycol) methyl ether methacrylate (M n 500), PEGDMA(M n 550) and AIBN were dried under high vacuum at room temperature.

[0273] Example 1: Preparation of electrolyte

[0274] Lithium (difluoromethanesulfonyl) (trifluoromethanesulfonyl) imide (LiDFTFSI) (161.40 mg) was added to a vial, followed by N,N-dimethylsulfamoyl fluoride (636.52 mg), and subsequently poly(ethylene glycol) methyl ether methacrylate (85.93 mg or 79.6 mL) (PEGMA) and poly(ethylene glycol) dimethacrylate (PEGDMA) (29.15 mg or 26.5 mL), and the solution was placed under stirring at 300 rpm for about 2 hours. After this time, the solution appeared to be uniform. Finally, azobisisobutyronitrile (AIBN) (0.69 mg) was added, and the solution was stirred at 300 rpm for another 10 minutes. After heating the mixture at 70°C for 12 hours, a gel electrolyte was obtained.

[0275] The final electrolyte composition is as follows:

[0276]

[0277] Example 2: Positive Electrode and Electrochemical Cell

[0278] Positive electrode preparation: LiNi 0.6 Mn 0.2 Co 0.2 The O2 (NMC622) (6.3 g) positive electrode was composed of 90 wt% NMC622, 5 wt% conductive carbon (Super C-65) (0.35 g), and 5 wt% polymer binder (PVdF) (0.35 g). The slurry was made using N-methyl-2-pyrrolidone (NMP) as a solvent (10 g), and after homogenization of the dispersion, it was cast on a carbon-coated aluminum current collector. Finally, it was dried at 80 ° C under vacuum overnight, yielding approximately 1.2 mAh cm -2 Up to 1.5 mAh cm -2 The electrodes were punched into a size of 12 mm diameter and subsequently dried again at 50 °C under vacuum before cell assembly.

[0279] Cell Assembly: Coin cells were assembled in an argon-filled glove box using an NMC622 (12 mm diameter) electrode as the positive electrode, a Celgard 2500 separator, and a Li metal disk (China Energy Lithium, 14 mm diameter and 500 μm thickness) as the negative electrode. The previously prepared electrolyte mixture was cast onto the separator, and the cell was sealed with a crimping press. The crosslinking process was then applied by holding the cell at 70°C for 12 hours.

[0280] Example 3: Electrochemical Measurements

[0281] The cells were galvanostatically cycled using a Maccor battery tester (4000 series) from 2.8 V to 4.25 V vs. Li / Li+. The protocol applied was based on 3 cycles at a current of C / 20 followed by continuous (both charge and discharge) cycling at C / 10 at 25°C and 40°C.

[0282] Figure 1 The discharge capacity and coulombic efficiency of Li°||NMC622 batteries comprising the gel electrolyte of the present invention at two different temperatures (40°C and 25°C) versus cycle number are shown. It is apparent that the discharge capacity and coulombic efficiency are maintained after at least 70 cycles.

Claims

1. A polymer electrolyte comprising: i. at least one polymer, ii. at least one sulfonamide, and iii. at least one lithium salt; The polymer electrolyte is further characterized in that the polymer electrolyte does not contain an organic carbonate, and wherein the at least one sulfonamide has the general formula I: in -R 1 selected from F, linear or branched C1-C 12 Alkyl, linear or branched C2-C 12 Alkenyl, C3-C 12 Cycloalkyl and C6-C 12 Aryl, and -R 2 and R 3 independently selected from linear or branched C1-C 12 Alkyl; linear or branched C2-C 12 Alkenyl; C6-C4-alkenyl which may be substituted by one or more fluorine atoms 12 Aryl; and -CH2CH2O-(CH2CH2O) n -R, wherein R is H or methyl and n is an integer from 1 to 20, or R 2 and R 3 They may combine with each other to form a nitrogen-containing aliphatic ring.

2. The polymer electrolyte according to claim 1, wherein the at least one polymer is selected from: -polyoxyalkylenes; -polyalkyleneimines; -polyalkylene sulfide; - polyethylene glycol, optionally comprising one or more crosslinkable groups; - poly(meth)acrylates or crosslinked polymers thereof with trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA); - polyphosphazene; - polysiloxanes; -polyvinyl alcohol (PVA); -polyvinylamine (PVAm); - polyvinyl acetate (PVAc); - polyvinyl halides; - polyacrylonitrile (PAN); - poly(vinylpyrrolidone) (PVP); -poly(2-vinylpyridine) (P2VP); -poly(ε-caprolactone) (PCL); -poly(maleimide); -polyaniline (PANI); - Chitosan (CS); or - any copolymer, any mixture or any cross-linked polymer thereof.

3. The polymer electrolyte according to claim 1 or 2, wherein the at least one polymer is selected from poly(ethylene glycol) methyl ether methacrylate, poly(ethylene glycol) dimethacrylate (PEGDMA), or a blend, copolymer or any cross-linked polymer thereof; or selected from a cross-linked polymer of butyl acrylate and trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA), wherein the weight ratio between poly(ethylene glycol) methyl ether methacrylate and PEGDMA, or the weight ratio between butyl acrylate and trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA) is from 50:1 to 1:1, more preferably from 10:1 to 2:1, and even more preferably about 3:

1.

4. The polymer electrolyte according to any one of claims 1 to 3, wherein the at least one polymer comprises 5 to 85 wt. % relative to the total weight of the electrolyte composition, preferably 8 to 60 wt. %, even more preferably 8 to 20 wt. %, even more preferably about 12 wt. % relative to the total weight of the electrolyte composition.

5. The polymer electrolyte according to any one of the preceding claims, wherein the at least one sulfonamide is a sulfonamide of formula I, in - R1 is selected from F and linear C1-C4 alkyl substituted with one or more fluorine atoms; and - R2 and R3 are linear C1-C 12 alkyl.

6. A polymer electrolyte according to any of the preceding claims, wherein the at least one sulfonamide constitutes 5 wt % to 85 wt % of the weight of the electrolyte, preferably 5 wt % to 80 wt % of the weight of the electrolyte, more preferably 40 wt % to 75 wt % of the weight of the electrolyte; even more preferably, the at least one sulfonamide is about 70 wt % of the weight of the electrolyte.

7. The polymer electrolyte according to any one of the preceding claims, wherein the at least one lithium salt is an organic or inorganic lithium salt selected from the group consisting of LiClO4, LiNO3, LiBF4, LiAsF6, LiPF6, LiBF3Cl, LiF, LiN(SO2CF3)2, LiN(SO2CF3)(SO2CF2H), LiN(SO2F)2, LiN(SO2CF3)(SO2F), LiN(C2F5SO2)(SO2F), LiB(C2 O4)2, LiBF2(C2O4), LiC(SO2CF3)3, LiPF3(C2F5)3, LiCF3SO3 and combinations thereof; preferably, the at least one lithium salt is selected from LiN(SO2CF3)(SO2CF2H), LiB(C2O4)2, LiN(SO2F)2, LiN(SO2CF3)2, LiN(SO2CF3)(SO2F) and combinations thereof; more preferably, the at least one lithium salt is LiN(SO2CF3)(SO2CF2H).

8. The polymer electrolyte according to any one of the preceding claims, wherein the at least one lithium salt represents 10 to 90 wt. %, preferably 10 to 50 wt. %, even more preferably 10 to 30 wt. %, even more preferably about 18 wt. %, relative to the total weight of the polymer electrolyte.

9. A polymer electrolyte according to any one of the preceding claims, comprising: i. at least one polymer selected from poly(ethylene glycol) methyl ether methacrylate, poly(ethylene glycol) dimethacrylate (PEGDMA), or any blend thereof, or any copolymer thereof, or any cross-linked polymer thereof; and cross-linked polymers of butyl acrylate with trimethylolpropane triacrylate (ETPTA) and / or pentaerythritol tetraacrylate (PETA); ii. a sulfonamide of formula I, in - R1 is selected from F and linear C1-C4 alkyl substituted with one or more fluorine atoms; and - R2 and R3 are linear C1-C4 alkyl groups; and iii. an organic lithium salt selected from the group consisting of LiN(SO2CF3)(SO2CF2H), LiB(C2O4)2, LiN(SO2F)2, LiN(SO2CF3)2, LiN(SO2CF3)(SO2F) and combinations thereof, more preferably, the lithium salt is LiN(SO2CF3)(SO2CF2H); The polymer electrolyte is further characterized in that the polymer electrolyte is in the form of a gel.

10. The polymer electrolyte of any one of claims 1 to 6 and 8 to 9, wherein the at least one lithium salt is a combination of a first lithium salt suitable for use in a lithium metal battery and a second lithium salt other than the first lithium salt, the first lithium salt being selected from LiN(SO2CF3)(SO2CF2H), LiN(SO2CF3)(SO2F) and LiN(C2F5SO2)(SO2F).

11. The polymer electrolyte according to claim 10, wherein the first lithium salt is LiN(SO2CF3)(SO2CF2H).

12. A polymer electrolyte according to claim 10 or claim 11, wherein the second lithium salt is selected from lithium perchlorate, lithium nitrate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium chlorotrifluoroborate, lithium fluoride, lithium oxide, lithium peroxide, a salt of formula LiN(SO2CF3)2, a salt of formula LiN(SO2F)2, a salt of formula LiN(SO2CF3)(SO2F), a salt of formula LiN(SO2C2F5)(SO2F), a salt of formula LiB(C2O4)2, a salt of formula LiBF2(C2O4), a salt of formula LiC(SO2CF3)3, a salt of formula LiPF3(C2F5)3, a salt of formula LiCF3SO3 and a mixture thereof.

13. The polymer electrolyte according to claims 10 to 12, wherein the second lithium salt is selected from lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium chlorotrifluoroborate, a salt of formula LiB(C2O4)2, a salt of formula LiBF2(C2O4), a salt of formula LiPF3(C2F5)3, a salt of formula LiCF3SO3 and a mixture thereof.

14. The polymer electrolyte according to any one of claims 10 to 13, wherein the second lithium salt is a salt of formula LiB(C2O4)2 or a salt of formula LiBF2(C2O4). 15 . The polymer electrolyte according to claim 10 , wherein a weight ratio of the first lithium salt to the second lithium salt is 1:1 to 2:

1.

16. A method for preparing the polymer electrolyte according to any one of claims 1 to 15, comprising the following steps: (i) providing at least one lithium salt; (ii) mixing at least one sulfonamide with the at least one lithium salt of step (i); (iii) adding at least one polymer to the mixture obtained in step (ii); and, (iv) optionally, crosslinking the at least one polymer contained in the mixture resulting from step (iii), when the polymer comprises one or more crosslinkable functional groups.

17. An electrochemical cell or battery comprising a polymer electrolyte according to any one of claims 1 to 15, a positive electrode, a negative electrode and optionally a separator.

18. The electrochemical cell or battery of claim 17, wherein: - The positive electrode material comprises lithium nickel manganese cobalt oxide; - the negative electrode is composed of metallic lithium; and - The optional separator is a polypropylene film.

19. Use of the electrochemical cell or battery according to claim 17 or 18 in the following: electric motors; electric vehicles, including electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), etc.; light electric vehicles, including electric bicycles (E-bikes) and electric scooters (E-scooters); electric golf carts; and power storage systems.

20. A method for preparing an electrochemical cell or battery according to claim 17 or 18, said method comprising the steps of: (i) providing a positive electrode; (ii) providing a negative electrode; (iii) providing a polymer electrolyte according to any one of claims 1 to 14; (iv) coating the surface of the positive electrode provided in step (i) and the surface of the negative electrode provided in step (ii) with the polymer electrolyte provided in step (iii) in such a manner that the electrolyte is disposed between the positive electrode and the negative electrode, the surface of the positive electrode and the surface of the negative electrode being optionally covered with a film before coating with the electrolyte; and (v) Optionally, when the polymer electrolyte includes a polymer having one or more cross-linkable functional groups, cross-linking the polymer included in the polymer electrolyte.

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