Polymer composition for electrolyte and / or positive electrode of rechargeable battery

Abstract

The present invention relates to a polymer composition having excellent ionic conductivity, the use of such a polymer composition for the preparation of a polymer electrolyte and / or a positive electrode of a rechargeable battery, a polymer electrolyte for a rechargeable battery comprising such a polymer composition, a positive electrode for a rechargeable battery comprising such a polymer composition, and a lithium or sodium rechargeable battery comprising such a polymer electrolyte and / or such a positive electrode.

Description

Technical Field

[0001] The present invention relates to the field of rechargeable batteries, and more specifically, to the field of lithium or sodium rechargeable batteries used in the manufacture of electric vehicles and / or the storage of intermittent power such as wind and / or sunlight.

[0002] More particularly, the present invention relates to a polymer composition having excellent ionic conduction properties, the use of such a polymer composition for the preparation of a polymer electrolyte and / or a positive electrode of a rechargeable battery, a polymer electrolyte for a rechargeable battery comprising such a polymer composition, a positive electrode for a rechargeable battery comprising such a polymer composition, and a lithium or sodium rechargeable battery comprising such a polymer electrolyte and / or such a positive electrode.

[0003] Currently commercially available lithium metal polymer batteries (or, LMP (registered trademark)) are generally "all-solid" batteries in the form of a thin film wound several times or several laminated thin films. This wound or laminated thin film has a thickness of about 100 micrometers. This generally comprises at least four functional films, namely a negative electrode (anode) that ensures the supply of lithium ions during discharge, a positive electrode (cathode) that acts as a receptacle into which lithium ions are inserted, a solid polymer electrolyte that conducts lithium ions and is located between the positive and negative electrodes, and a current collector connected to the positive electrode to ensure electrical connection. The negative electrode generally consists of a thin sheet of lithium metal or a lithium alloy, the solid polymer electrolyte is generally composed of a polymer based on poly(ethylene oxide) (PEO) and at least one lithium salt, and the positive electrode is usually a metal oxide (e.g., V2O5, LiV3O8, LiCoO2, LiNiO2, LiMn2O4, or LiNi 0.5 Mn 0.5It includes an active electrode material based on, for example, O2 or a phosphate such as LiMPO4 (where M represents a metal cation selected from the group consisting of Fe, Mn, Co, Ni, and Ti, and combinations thereof), and optionally further includes carbon. The current collector is generally made of a thin metal sheet.

[0004] Solid polymer electrolytes offer significant advantages in terms of safety as they avoid the use of solvents that can be dangerous in the event of overheating. Thus, such batteries can operate at high temperatures without the risk of explosion. However, commonly used solid polymer electrolytes such as high molecular weight PEO doped with lithium salts have low ionic conductivity at room temperature, so the operating temperature has to be maintained relatively high (typically 70 - 100 °C). However, at these temperatures, PEO becomes a viscous liquid and loses its dimensional stability. Furthermore, attempts to improve the ionic conductivity of PEO by adding plasticizers have led to a decrease in mechanical properties.

[0005] The ionic conductivity of an electrolyte characterizes the ability of electrically charged ions to move through the electrolyte. The higher the ionic conductivity of the electrolyte, the greater the movement of ions in the electrolyte. Polymer electrolytes have at least 10 -5When it has an ionic conductivity of S / cm, it can be considered interesting. The transference number t of an ion, which is denoted as t, represents the proportion of the applied current that this ion transports in the electrolyte. t is between 0 and 1. Since lithium ions are the ions involved in the chemical reactions occurring at the electrodes of a lithium metal polymer battery, for the electrolyte, a transference number t as close to 1 as possible is desirable. In solid polymer electrolytes such as PEO doped with lithium salts, due to the strong interaction between lithium cations and PEO chains, the proportion of the charge carried by lithium ions is small (about 0.2), which limits the electrical performance. The low transference number of cations results in the formation of a salt concentration gradient across the thickness of the electrolyte during battery operation. This behavior causes salt depletion at the electrodes, leading to an increase in the resistance of the electrolyte and a decrease in output performance, making it easier for lithium dendrites to form, resulting in a decrease in Faradaic efficiency, and ultimately leading to a short circuit.

[0006] To obtain a t value close to 1, polymers have been described in which anions form covalent bonds with the polymer chains and lithium counterions are the only mobile species.

[0007] In particular, Meziane et al. (Electrochimica Acta, 2011, 57, 14 - 19) described the preparation of polystyrene having a sulfonyl(trifluoromethylsulfonyl)imide group by radical polymerization from sodium 4 - styrene - sulfonyl(trifluoromethylsulfonyl)imide monomer. Subsequently, this ionic polystyrene was mixed with PEO to produce an electrolyte membrane that does not contain additional lithium ions. However, the results obtained show a relatively low ionic conductivity (e.g., about 3.1x10 -6 S / cm) at temperatures below 60 °C.

[0008] Accordingly, an object of the present invention is to overcome the drawbacks of the above-described prior art, and to provide a polymer composition that exhibits excellent ionic conductive properties and a high lithium ion transference rate while ensuring good mechanical strength so as to be usable as a polymer electrolyte for rechargeable batteries, particularly lithium or sodium rechargeable batteries.

[0009] The object of the present invention is achieved by the polymer composition described below. In fact, the inventors of the present application have surprisingly discovered that it is possible to add an ion-non-conductive fluoropolymer to a specific cationic unipolar conductive polymer combined with a plasticizer in order to greatly improve the ionic conductivity of the polymer composition.

[0010] Polymer composition Accordingly, a first object of the present invention is a polymer composition comprising at least one cationic unipolar conductive polymer, at least one plasticizer, and at least one ion-non-conductive fluoropolymer, wherein the cationic unipolar conductive polymer is a homopolymer or copolymer comprising at least one organic polymer chain, an organic anionic functional group that forms a covalent bond with the organic polymer chain, and a metal cation (ionically) bonded to the organic anionic functional group.

[0011] The combination of the cationic unipolar conductive polymer, plasticizer, and ion-non-conductive fluoropolymer as defined above produces a polymer composition having excellent ionic conductive properties.

[0012] Cationic unipolar conductive polymer In the present invention, the cationic unipolar conductive polymer means a polymer (homopolymer or copolymer) containing at least one organic polymer chain, an organic anionic functional group that forms a covalent bond with the organic polymer chain, and a metal cation bonded to the organic anionic functional group. These metal cations are the mobile species responsible for the ionic conduction of the polymer. In other words, the organic anionic functional group is grafted onto the organic polymer chain and / or is a pendant organic anionic functional group.

[0013] The term "organic polymer chain" means a polymer chain that does not contain metals and metalloids. In other words, the organic polymer chain does not contain a metal or a metalloid such as silicon, or is different from a polysiloxane chain, or does not contain an Si - O bond.

[0014] The term "organic anionic functional group" means an anionic functional group that does not contain metals and metalloids. In other words, the organic anionic functional group does not contain a metal or a metalloid such as silicon, or does not contain an Si - O bond.

[0015] The cationic unipolar conductive polymer of the present invention is a polymer containing organic anionic repeating units (an organic polymer chain and an organic anionic functional group covalently bonded to this organic chain), and these organic anionic repeating units are (ionically) bonded to metal cations.

[0016] The cationic unipolar conductive polymer is preferably obtained by radical polymerization using at least one monomer in which at least one organic anionic functional group is grafted by a covalent bond and at least one metal cation is bonded to the organic anionic functional group.

[0017] The cationic unipolar conductive polymer is · a) a homopolymer that can be prepared from a monomer in which at least one organic anionic functional group is grafted by a covalent bond and at least one metal cation is bonded to the organic anionic functional group, or · a) at least one monomer in which at least one organic anionic functional group is grafted by a covalent bond and at least one metal cation is bonded to the organic anionic functional group, and b) a copolymer that can be made from b1) at least one monomer in which at least one organic anionic functional group is grafted by a covalent bond and at least one metal cation is bonded to the organic anionic functional group, and b2) at least one other monomer different from monomer a) selected from organic monomers It may be.

[0018] The term "organic monomer b2)" means a monomer that does not contain metals and metalloids. In other words, the organic monomer does not contain a metal or a metalloid such as silicon, and / or is not a compound containing an Si-O bond.

[0019] The metal cation (of the monomer) or the metal cation (of the polymer) bonded to the organic anionic functional group is preferably Li + and Na + selected from cations, and particularly preferably Li + cation.

[0020] Monomer a) or b1), that is, at least one monomer in which at least one organic anionic functional group is grafted by a covalent bond and at least one metal cation is bonded to the organic anionic functional group, may be selected from aromatic and non-aromatic vinyl monomers, and such aromatic and non-aromatic vinyl monomers include at least one organic anionic functional group grafted to the organic monomer by a covalent bond and at least one metal cation bonded to the organic anionic functional group.

[0021] Examples of aromatic vinyl monomers include styrene and its derivatives.

[0022] Styrene derivatives are preferably derivatives in which the phenyl portion of styrene is substituted with one or more groups selected from methyl, ethyl, and tert-butyl.

[0023] Examples of non-aromatic vinyl monomers include acrylates, methacrylates, acrylamides, methacrylamides, ethylene, propylene, dienes, or maleimides.

[0024] The organic monomer b2) may be vinylidene fluoride, phosphate, phosphonate, ether, carbonate, malonate, amide, acrylate, anhydride, or ester.

[0025] In this embodiment, the copolymer includes vinylidene fluoride, phosphate, phosphonate, ether, carbonate, malonate, amide, acrylate, anhydride, or ester repeating units in addition to the organic anionic repeating units linked to metal cations.

[0026] The organic anionic functional group of (monomers a) and b1)) or the organic anionic functional group of (the polymer) can be selected from sulfonic acid, boric acid, and imide functional groups.

[0027] The organic anionic functional group is preferably imide, particularly preferably bis-sulfonyl imide, even more particularly preferably sulfonyl(trifluoromethanesulfonyl)imide (TFSI) or sulfonyl(fluorosulfonyl)(FSI)imide, and even more particularly preferably sulfonyl(trifluoro-methane)imide (TFSI).

[0028] According to a particularly preferred embodiment of the present invention, at least one organic anionic imide functional group is grafted by a covalent bond, and the organic anionic imide functional group has Li as a metal cation + The aromatic or non-aromatic vinyl monomer linked to is selected from the following monomers (I-a) to (I-i)

Chemical formula

[0029] The cationic unipolar conductive polymer is preferably polystyrene-sulfonyl(trifluoromethylsulfonyl) lithium imide (PSTFSILi) or polymethacrylate-sulfonyl(trifluoromethylsulfonyl) lithium imide (PMTFSILi).

[0030] The cationic unipolar conductive polymer preferably has a number average molar mass (i.e., Mn) in the range of about 10,000 g / mol to 1,000,000 g / mol, particularly preferably in the range of about 50,000 g / mol to 700,000 g / mol.

[0031] In the present invention, the number average molecular weight is measured by methods well known to those skilled in the art, particularly by gel permeation chromatography (GPC).

[0032] The cationic unipolar conductive polymer preferably corresponds to about 5 to 40% by mass, more particularly preferably about 5 to 30% by mass, based on the total mass of the polymer composition.

[0033] The cationic unipolar conductive polymer already contains an anionic functional group (an anionic group derived from a lithium salt or sodium salt directly grafted onto the structure of the polymer material). Therefore, the polymer composition preferably does not contain additional or supplementary lithium salts or sodium salts, such as, for example, molecular lithium salts or sodium salts (i.e., lithium salts or sodium salts not grafted onto the polymer material).

[0034] Ionic non-conductive fluoropolymer In the present invention, the ionic non-conductive polymer is a polymer that does not conduct lithium ions or sodium ions. In other words, the ionic non-conductive polymer has an ionic conductivity of less than 10 -7 S / cm, particularly at the operating temperature.

[0035] The ion non-conductive fluoropolymer preferably corresponds to about 5 to 45% by weight, more particularly preferably about 5 to 40% by weight, based on the total mass of the polymer composition.

[0036] The ion non-conductive polymer is fluorinated. In other words, it is a polymer in which the repeating unit is a fluorocarbon and thus contains a plurality of carbon-fluorine bonds.

[0037] The ion non-conductive fluoropolymer of the polymer composition of the present invention can be selected from vinyl fluoride (VF) homopolymers and copolymers, vinylidene fluoride (VdF) homopolymers and copolymers, tetrafluoroethylene (TFE) homopolymers and copolymers, chlorotrifluoroethylene (CTFE) homopolymers and copolymers, hexafluoropropylene (HFP) homopolymers and copolymers, and mixtures thereof.

[0038] According to a particularly preferred embodiment of the present invention, the ion non-conductive fluoropolymer is selected from vinylidene fluoride (VdF) homopolymers and copolymers such as PVdF or P(VdF-HFP).

[0039] According to an even more particularly preferred embodiment, the ion non-conductive fluoropolymer is PVdF.

[0040] The weight ratio of the non-conductive fluoropolymer to the cationic unipolar conductive polymer in the polymer composition is preferably about 20 / 80 to 90 / 10, particularly preferably about 40 / 60 to 80 / 20.

[0041] The ion non-conductive fluoropolymer preferably has a number average molar mass (i.e., Mn) in the range of about 50,000 g / mol to 1,300,000 g / mol.

[0042] Plasticizer The polymer composition contains at least one plasticizer. The plasticizer is a non-aqueous solvent. Thereby, a gel-like polymer composition can be formed.

[0043] The non-aqueous solvent or plasticizer is · linear and cyclic carbonates such as propylene carbonate (PC), ethylene carbonate (EC), dimethyl carbonate (DMC), diethyl carbonate (DEC), or methyl isopropyl carbonate (MiPC), · fluorinated carbonates such as fluoroethylene carbonate, · nitriles such as succinonitrile, · lactones such as γ-butyrolactone, · polyethylene glycol dimethyl ethers (or PEGDME) such as dimethyl ether, tetraethylene glycol dimethyl ether (TEGDME), or liquid linear and cyclic polyethers such as dioxolane, · fluorinated polyethers, · sulfur solvents such as sulfolane or dimethyl sulfoxide, · phosphates such as triethyl phosphate or fluorophosphate, · esters such as ethyl acetate or ethyl butyrate (EB), and · mixtures thereof may be selected from. Among such solvents or plasticizers, linear and cyclic carbonates are particularly preferred.

[0044] The solvent or plasticizer is preferably about 25 to 90% by weight, particularly preferably about 35 to 90% by weight, and even more preferably about 65 to 90% by weight based on the total weight of the polymer composition.

[0045] Additives in the polymer composition The polymer composition of the present invention may further contain a reinforcing agent. Thus, it becomes possible to adjust the mechanical properties of the polymer composition.

[0046] This reinforcing agent is preferably selected from cellulose nanofibrils and ceramic nanoparticles such as titanium oxide, aluminum oxide, or silicon oxide nanoparticles.

[0047] According to a particularly preferred embodiment of the present invention, the polymer composition · about 40 to 90% by weight of a plasticizer, preferably about 65 to 90% by weight of a plasticizer, · about 5 to 35% by weight of an ion-non-conductive fluoropolymer, and · about 5 to 35% by weight of a cationic unipolar conductive polymer comprises (or consists of).

[0048] In fact, the blend of the ion-non-conductive fluoropolymer and the cationic unipolar conductive polymer retains good mechanical strength and can absorb the plasticizer while remaining solid or quasi-solid. Furthermore, the presence of the plasticizer results in a solid or quasi-solid polymer composition having excellent ionic conductivity (e.g., conductivity of at least 1x10 -5 S / cm at 25 °C).

[0049] The polymer composition of the present invention is preferably prepared by mixing various components, namely a cationic unipolar conductive polymer, a plasticizer, and an ion-non-conductive fluoropolymer. In particular, the components (ion-non-conductive fluoropolymer, cationic unipolar conductive polymer, and plasticizer) are conveniently mixed in an organic solvent such as acetonitrile under magnetic stirring. The mixing can be carried out under heat, in particular at a temperature of at least 50 °C, preferably at least 80 °C, and even more preferably at least 90 °C. The resulting mixture can then be conveniently deposited on a substrate by coating at room temperature (e.g., 18 - 25 °C). Then, drying can be carried out, in particular to remove the organic solvent.

[0050] Use of the polymer composition The second object of the present invention is to use the polymer composition as defined in the first object of the present invention to create a polymer electrolyte and / or a positive electrode of a rechargeable battery, preferably a lithium or sodium rechargeable battery, particularly preferably a lithium metal or sodium metal battery, and even more particularly preferably a lithium metal battery.

[0051] By using the polymer composition according to the present invention to create a polymer electrolyte of a rechargeable lithium battery, excellent low-temperature performance (i.e., less than 60 °C, preferably 40 °C or less), particularly a lithium ion transference number of about 1, and an ionic conductivity of 10 -5 S.cm -1 or more, preferably 5x10 -5 S.cm -1 or more, particularly preferably 10 -4 S.cm -1 or more at temperatures up to 40 °C are achieved. The high transference number suppresses the formation of concentration gradients in the polymer electrolyte during discharge (or charging), thereby enhancing the power performance (or charging speed). Furthermore, the use of this polymer composition suppresses the dendritic growth of lithium and thus enables the concept of rapid and safe charging. This is because the problem in lithium metal battery technology is the formation of non-uniform lithium electrodeposits (such as dendrites) during charging, which can reduce cycle life and cause short circuits. Furthermore, the polymer composition compatible with the present invention exhibits good mechanical strength, high thermal stability (ensuring the safety of the energy storage device incorporating them), and excellent potential stability (stability up to 4.5 V (vs. Li + / Li)).

[0052] By using the polymer composition compatible with the present invention to create a positive electrode of a secondary lithium metal or sodium metal battery, it becomes possible to improve the ionic conductivity, and thus it becomes possible to lower the operating temperature of the battery and improve the power response. Also, this polymer composition improves the adhesion between the positive electrode and the current collector.

[0053] Polymer electrolyte A third object of the present invention is a polymer electrolyte for a rechargeable battery, characterized by comprising a polymer composition according to the first object of the present invention, or a porous separator impregnated with the polymer composition according to the first object of the present invention.

[0054] The porous separator can be made from an electronically non-conductive porous material, preferably a porous polymer material based on at least one polyolefin (e.g., polyethylene or polypropylene) or fiber (e.g., glass or wood fiber).

[0055] The polymer electrolyte is preferably in the form of a film, and particularly preferably in the form of a film having a thickness in the range of about 5 to 45 μm, more preferably about 10 to 25 μm.

[0056] When the polymer electrolyte comprises (or consists of) a porous separator impregnated with the polymer composition according to the first object, the porous separator is preferably coated with the polymer composition on a first surface and a second surface facing the first surface.

[0057] The polymer (solid or quasi-solid) electrolyte can be prepared by any technique well known to those skilled in the art, such as coating, extrusion, or pressing (cold or hot).

[0058] The polymer electrolyte is preferably suitable for rechargeable lithium or sodium batteries, particularly preferably lithium metal or sodium metal batteries, and even more preferably lithium metal batteries.

[0059] Positive electrode A fourth object of the present invention is a positive electrode for a rechargeable battery comprising a positive electrode active material and a polymer composition, and optionally further comprising a substance that generates electronic conductivity, wherein the polymer composition is the polymer composition as defined in the first object of the present invention.

[0060] The positive electrode is preferably suitable for rechargeable lithium or sodium batteries, particularly preferably lithium metal or sodium metal batteries, and even more preferably lithium metal batteries.

[0061] Positive electrode active material The active material of the positive electrode is a reversible active material for lithium ions or sodium ions. In other words, lithium ions or sodium ions can be reversibly inserted and removed.

[0062] The positive electrode active material is · Vanadium oxide VO x (2 ≦ x ≦ 2.5), LiV3O8, Li y Ni 1-x Co x O2(0 ≦ x ≦ 1; 0 ≦ y ≦ 1), manganese spinel Li y Mn 1-x M x O2(M = Cr, Al, V, Ni,; 0 ≦ x ≦ 0.5; 0 ≦ y ≦ 2), V2O5, for example LiCoO2, LiNiO2, LiMn2O4, LiNi 1 / 3 Mn 1 / 3 Co 1 / 3 O2 (NMC), LiNi 0.8 Co 0.15 Al 0.05 O2 (NCA), and lithium oxides such as LiNi 0.5 Mn 0.5 O2, etc., metal oxides, · Silicates or metal phosphates, such as Li3V2(PO4)3 or LiMPO4 (M represents a metal cation selected from Fe, Mn, Co, Ni, Ti, and combinations thereof), or · Metal sulfates, such as iron sulfate Fe2(SO4)3 may be used.

[0063] The active material of the positive electrode may correspond to about 50 to 90% by mass, preferably about 55 to 80% by mass, based on the total mass of the positive electrode.

[0064] Substances that generate electronic conductivity The substance that generates electronic conductivity may be selected from at least one conductive metal's metal particles and fibers such as carbon black, acetylene black, carbon fiber and nanofiber, carbon nanotube, graphene, graphite, aluminum, platinum, iron, cobalt, and nickel, and mixtures thereof.

[0065] The substance that generates electronic conductivity is preferably carbon black. The substance that generates electronic conductivity can correspond to about 0.1 to 10% by mass, preferably about 0.5 to 5% by mass, based on the total mass of the positive electrode.

[0066] Polymer composition The polymer composition is the polymer composition as defined in the first object of the present invention. The polymer composition may correspond to about 10 to 49.5% by mass, preferably about 20 to 40% by mass, based on the total mass of the positive electrode.

[0067] The positive electrode preferably does not contain a lithium or sodium molecular salt. The positive electrode is preferably in the form of a film having a thickness generally on the order of 20 to 100 micrometers.

[0068] Rechargeable lithium or sodium battery The fifth object of the present invention is · A negative electrode containing a lithium metal, sodium metal, lithium metal alloy, or sodium metal alloy, · A positive electrode possibly supported by a current collector, · A polymer electrolyte located between the positive electrode and the negative electrode A rechargeable lithium or sodium battery comprising: A rechargeable lithium or sodium battery, characterized in that the polymer electrolyte is the polymer electrolyte as defined in the third object of the present invention, and / or the positive electrode is the positive electrode as defined in the fourth object of the present invention.

[0069] Negative electrode The negative electrode is preferably in the form of a film with a thickness generally on the order of 1 to 100 micrometers.

[0070] The negative electrode may be composed of one of alloys of lithium such as lithium metal, sodium metal, an alloy of lithium and sodium, silicon, tin, aluminum, magnesium, silver, zinc, or germanium, or one of alloys of sodium such as an alloy of sodium and lithium, silicon, tin, magnesium, silver, zinc, or germanium, silver, zinc, or germanium. The negative electrode is preferably composed of one of lithium metal or its alloys.

[0071] Positive electrode The positive electrode may be the positive electrode according to the fourth object of the present invention, or the positive electrode may include a positive electrode active material, a polymer binder, optionally a plasticizer, and optionally a substance that generates electronic conductivity.

[0072] The positive electrode active material and the substance that generates electronic conductivity are the substances as defined in the fourth object of the present invention.

[0073] Plasticizer The plasticizer (or non-aqueous solvent) is · Linear and cyclic carbonates such as propylene carbonate (PC), ethylene carbonate (EC), dimethyl carbonate (DMC), diethyl carbonate (DEC), or methyl isopropyl carbonate (MiPC), · Fluorinated carbonates such as fluoroethylene carbonate, · Nitriles such as succinonitrile, · Lactones such as γ-butyrolactone, · Polyethylene glycol dimethyl ethers (or PEGDME) such as dimethyl ether, tetraethylene glycol dimethyl ether (TEGDME), or liquid linear or cyclic polyethers such as dioxolane, · Fluorinated polyethers, · Sulfur solvents such as sulfolane or dimethyl sulfoxide, · Phosphates such as triethyl phosphate or fluorophosphate, · Esters such as ethyl acetate or ethyl butyrate (EB), and · Mixtures thereof can be selected from.

[0074] Among such solvents or plasticizers, linear and cyclic carbonates are particularly preferred. The plasticizer for the positive electrode may correspond to about 5 to 35% by mass, preferably about 10 to 25% by mass, based on the total mass of the positive electrode.

[0075] Polymer binder The polymer binder may be selected from ethylene homopolymers and copolymers, propylene homopolymers and copolymers; homopolymers and copolymers of ethylene oxide (e.g., PEO, copolymers of PEO), methylene oxide, propylene oxide, epichlorohydrin, allyl glycidyl ether, and mixtures thereof; halogenated polymers such as polyvinyl chloride, vinylidene fluoride (PVdF), vinylidene chloride, tetrafluoroethylene, or chlorotrifluoroethylene, or homopolymers and copolymers of mixtures thereof; electronically non-conductive anionic polymers such as poly(styrene sulfonate), poly(acrylic acid), poly(glutamate), alginate, pectin, gelatin, or mixtures thereof; cationic polymers such as polyethyleneimine (PEI), polyaniline in the form of emeraldine salt (ES), quaternized poly(N-vinylimidazole), poly(acrylamide-diallyldimethylammonium chloride) (AMAC), or mixtures thereof; polyacrylate; elastomers such as homopolymers or copolymers of ethylene, propylene, styrene, butadiene, or chloroprene; cationic unipolar conductive polymers; and mixtures thereof.

[0076] The cationic unipolar conductive polymer may be a cationic unipolar conductive polymer as defined in the first object of the present invention.

[0077] The polymer binder may correspond to about 5 to 35% by mass, preferably about 10 to 25% by mass, based on the total mass of the positive electrode.

[0078] According to a preferred embodiment of the present invention, the active material of the positive electrode is coated with a carbon layer. The presence of the carbon layer enables improvement of the interface: active material - polymer binder.

[0079] The carbon coating the active material preferably corresponds to about 0.1 to 5% by mass based on the mass of the active material.

[0080] The carbon layer is preferably in the form of a layer having various thicknesses of about 1 to 4 nm. The positive electrode may further contain a lithium salt or a sodium salt, particularly when the polymer binder is other than the cationic unipolar conductive polymer.

[0081] According to a particularly preferred embodiment of the present invention, the positive electrode is a positive electrode that meets the fourth object of the present invention.

[0082] Current collector The rechargeable battery may further include a current collector connected to the positive electrode. The current collector generally consists of a thin metal plate. The current collector is preferably a current collector made of stainless steel or aluminum optionally covered with a carbon-based layer (corrosion protection layer).

[0083] Polymer electrolyte The polymer electrolyte may be a polymer electrolyte that meets the third object of the present invention, or the polymer electrolyte may include a cationic unipolar conductive polymer, or a combination of at least one lithium salt and at least one polymer material selected from polyethylene oxide (PEO)-based polymer materials, polycarbonates, and polyesters.

[0084] Poly(ethylene oxide) (PEO)-based polymer materials can be selected from polystyrene-poly(ethylene oxide) (PS-b-PEO) block copolymers, polystyrene-poly(ethylene oxide)-polystyrene (PS-b-PEO-b-PS) block copolymers, random poly(ethylene oxide-co-propylene oxide) copolymers (i.e., PEO-ran-PPO), random poly(ethylene oxide-co-butylene oxide) copolymers (i.e., PEO-ran-PBO), poly(ethylene oxide), and mixtures thereof.

[0085] Lithium salts used in combination with the poly(ethylene oxide)-based polymer materials are lithium fluoride (LiFO3), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium metaborate (LiBO2), lithium perchlorate (LiCIO4), lithium nitrate (LiNO3), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(pentafluoroethyl)imide (LiBETI), LiAsF6, LiCF3SO3, LiSbF6, LiSbCl6, Li2TiCl6, Li2SeCl6, Li2B 10 CI 10 、Li2B 12 CI 12 、 lithium bis(oxalato)borate (LiBOB), and mixtures thereof.

[0086] The lithium salt preferably corresponds to 5 to 30% by mass, more preferably 10 to 25% by mass, based on the total mass of the polymer electrolyte.

[0087] The poly(ethylene oxide) (PEO)-based polymer material can be combined with a reinforcing agent. Thus, the mechanical properties of the polymer material can be adjusted thereby.

[0088] This reinforcing agent is preferably selected from ceramic nanoparticles such as cellulose nanofibrils, titanium oxide, aluminum oxide, or silicon oxide nanoparticles, and fluorinated polymers and copolymers such as polyvinylidene fluoride (PVdF) or a copolymer of vinylidene fluoride - hexafluoropropylene (PVdF - co - HFP). The cationic unipolar conductive polymer may be a cationic unipolar conductive polymer as defined in the first object of the present invention.

[0089] According to a particularly preferred embodiment of the present invention, the polymer electrolyte is a polymer electrolyte that meets the third object of the present invention.

[0090] The present invention will be described by the following embodiments, but the present invention is not limited to the following embodiments. The accompanying drawings illustrate the present invention.

Brief Description of the Drawings

[0091]

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Example

[0092] The raw materials used in the examples are listed below: · Carbon black, Sumitomo Corp, model number "ECP-600JD", · Lithium manganese iron phosphate (LMFP), Huayi, grade 2, · PVDF, commercially available as "5130" from Solvay, molar mass Mw = 900,000 g / mol, · PVdF-HFP, commercially available as "Kynarflex 2751" from Arkema, · Propylene carbonate (PC), Aldrich, anhydrous, purity 99.7%, · Triethyl phosphate (TEP), TCI, purity > 99.0%, · PMTFSI: Poly((trifluoromethane)sulfonimide lithium methacrylate), Specific Polymers, molar mass Mn = 238,330 g / mol, · PSTFSI: Poly(styrene tri(fluoromethane)sulfonimide), molar mass Mn = 84,720 g / mol, · PMMA: Poly(methyl methacrylate), Sigma - Aldrich, Mw is approximately 996,000 g / mol, · Acetonitrile, Sigma - Aldrich, anhydrous, purity 99.8%, · Lithium metal foil, Ganfeng, laminated to 72 μm after extrusion, · Lithium metal electrode, Ganfeng, laminated to 72 μm after extrusion, · Lithium metal anode with a thickness of 72 μm, Ganfeng, laminated to 72 μm after extrusion, · "EnSafe 65" current collector, Armor. Unless otherwise specified, all materials are used as received from the manufacturer.

[0093] Example 1: Preparation of polymer electrolyte EP1* that does not conform to the present invention and polymer electrolytes EP2, EP3, EP4, and EP5 that conform to the present invention

[0094] A plurality of polymer electrolytes containing PVdF as an ion - non - conducting fluoropolymer, PMTFSI as a cationic unipolar conductive polymer, and propylene carbonate as a plasticizer were prepared as detailed below.

[0095] The components (ion - non - conducting fluoropolymer, cationic unipolar conductive polymer, and plasticizer) were mixed with acetonitrile (ACN) in a beaker at 100 °C under magnetic stirring (300 rpm). For 1 g of the mixture of the ion - non - conducting fluoropolymer and the cationic unipolar conductive polymer, 1 g of the plasticizer and 5 g of acetonitrile were used. After mixing, the resulting mixture was coated on a silicone - coated polyethylene terephthalate (PET) support at room temperature at 8 mm / s to form a film, and then dried in a ventilation hood for several minutes to evaporate the residual acetonitrile.

[0096] Table 1 below shows the mass percentages of the various components present in the electrolytes prepared according to the above procedure, along with their thicknesses:

Table 1

[0097] Next, for each of these polymer electrolytes, a lithium electrolyte lithium (LEL) cell is manufactured by sequentially laminating a lithium foil, the polymer electrolyte membrane prepared as described above, and another lithium foil at 75°C under dry air.

[0098] For the polymer electrolyte EP1* that does not conform to the present invention, the lamination is performed at a pressure of 2 bar. For the remaining polymer electrolytes EP2 to EP5, the lamination is performed at a pressure of 5 bar.

[0099] Cells LEL1*, LEL2, LEL3, LEL4, and LEL5 each containing polymer electrolytes EP1*, EP2, EP3, EP4, and EP5 are placed in a 2-bar compression system.

[0100] The ionic conductivities of the polymer electrolytes EP1*, EP2, EP3, EP4, and EP5 are measured by impedance spectroscopy using an apparatus sold by Zahner under the trade name IM6EX. The measurement is performed in a constant potential mode between 100 mHz and 1 MHz for an amplitude of 10 mV at 20°C and 40°C in cells LEL1*, LEL2, LEL3, LEL4, and LEL5 prepared as described above.

[0101] FIG. 1 shows the ionic conductivity (unit: S.cm -1 )) as a function of temperature (measured as the ratio of 1000 / temperature, unit: Kelvin -1) shows the change. The higher the PVdF content in the polymer electrolyte, the greater its ionic conductivity. The introduction of PVdF as an ion-nonconductive fluoropolymer helps improve the ionic conductivity of a polymer electrolyte based on at least one cationic unipolar conductive polymer such as PMTFSI plasticized with at least one plasticizer such as propylene carbonate.

[0102] Example 2: Preparation of polymer electrolyte EP6* that does not conform to the present invention and polymer electrolytes EP7, EP8, EP9, and EP10 that conform to the present invention

[0103] A plurality of polymer electrolytes containing PVdF as an ion-nonconductive fluoropolymer, PSTFSI as a cationic unipolar conductive polymer, and propylene carbonate as a plasticizer were prepared as detailed below.

[0104] The components (ion-nonconductive fluoropolymer, cationic unipolar conductive polymer, and plasticizer) were mixed with acetonitrile (ACN) in a beaker at 100 °C under magnetic stirring (300 rpm). For 1 g of the mixture of the ion-nonconductive fluoropolymer and the cationic unipolar conductive polymer, 1 g of the plasticizer and 5 g of acetonitrile were used. After mixing, the resulting mixture was coated on a silicone-coated polyethylene terephthalate (PET) support at room temperature at 8 mm / s to form a film, and then dried in a ventilation hood for several minutes to evaporate the residual acetonitrile.

[0105] Table 2 below shows the mass percentages of the various components present in the electrolytes prepared according to the above procedure, along with their thicknesses:

Table 2

[0106] Next, for each of these polymer electrolytes, a lithium electrolyte lithium (LEL) cell is manufactured by sequentially laminating a lithium foil, the polymer electrolyte membrane prepared as described above, and another lithium foil at 75°C under dry air.

[0107] For the polymer electrolyte EP6* that does not conform to the present invention, the lamination is performed at a pressure of 2 bar. Also, to prevent short circuits, two layers of the polymer electrolyte EP6* are used. For the remaining polymer electrolytes EP7 to EP10 that conform to the present invention, the lamination is performed at a pressure of 5 bar.

[0108] Cells LEL6*, LEL7, LEL8, LEL9, and LEL10 each containing the polymer electrolytes EP6*, EP7, EP8, EP9, and EP10 are placed in a 2-bar compression system.

[0109] The ionic conductivities of the polymer electrolytes EP6*, EP7, EP8, EP9, and EP10 are measured as described in Example 1.

[0110] Figure 2 shows the ionic conductivity (unit: S.cm -1 )) as a function of temperature (measured as the ratio of 1000 / temperature, unit: Kelvin -1 ) for the polymer electrolytes EP6* (curve of black circles connected by solid lines), EP7 (curve of black circles connected by wide dotted lines), EP8 (curve of black circles connected by normal dotted lines), EP9 (curve of black circles connected by short dotted lines), and EP10 (curve of black triangles connected by solid lines). The introduction of PVdF as an ion-nonconductive fluoropolymer helps to improve the ionic conductivity of polymer electrolytes based on at least one cationic unipolar conductive polymer such as PSTFSI plasticized with at least one plasticizer such as propylene carbonate. The ionic conductivity reaches a maximum at a PVdF content of 35% by mass based on the total mass of the polymer electrolyte.

[0111] Example 3: Preparation of Polymer Electrolyte EP11* Not Compatible with the Present Invention and Polymer Electrolytes EP12 and EP13 Compatible with the Present Invention

[0112] A plurality of polymer electrolytes containing PVdF as an ion-nonconductive fluoropolymer, PMTFSI as a cationic unipolar conductive polymer, and triethyl phosphate (TEP) as a plasticizer were prepared as detailed below.

[0113] The components (ion-nonconductive fluoropolymer, cationic unipolar conductive polymer, and plasticizer) were mixed with acetonitrile (ACN) in a beaker at 100 °C under magnetic stirring (300 rpm). For 1 g of the mixture of the ion-nonconductive fluoropolymer and the cationic unipolar conductive polymer, 1 g of the plasticizer and 5 g of acetonitrile were used. After mixing, the resulting mixture was coated on a silicone-coated polyethylene terephthalate (PET) support at room temperature at 8 mm / s to form a film, and then dried in a ventilation hood for several minutes to evaporate the residual acetonitrile.

[0114] Table 3 below shows the mass percentages of the various components present in the electrolytes prepared according to the above procedure, together with their thicknesses:

Table 3

[0115] Then, for each of these polymer electrolytes, a lithium electrolyte lithium (LEL) cell was manufactured by sequentially laminating a lithium foil, the polymer electrolyte membrane prepared as above, and another lithium foil at 75 °C under dry air.

[0116] For the polymer electrolyte EP11* not compatible with the present invention, the laminate was fabricated at a pressure of 2 bar, and a lithium electrode was used instead of two lithium foils. For the remaining polymer electrolytes EP12 - EP13 compatible with the present invention, the lamination was carried out at a pressure of 5 bar.

[0117] Cells LEL11*, LEL12, and LEL13, each containing polymer electrolytes EP11*, EP12, and EP13, are placed in a 2 bar compression system.

[0118] The ionic conductivities of polymer electrolytes EP11*, EP12, and EP13 are measured as described in Example 1.

[0119] Figure 3 shows the ionic conductivity (units are S.cm -1 )) as a function of temperature (measured as the ratio of 1000 / temperature, units are Kelvin -1 ) for polymer electrolytes EP11* (curve of black circles connected by solid lines), EP12 (start of the curve by black squares), and EP13 (curve of black circles connected by dotted lines). The higher the PVdF content of the polymer electrolyte, the greater its ionic conductivity. The introduction of PVdF as an ion-non-conductive polymer helps to improve the ionic conductivity of polymer electrolytes based on at least one cationic unipolar conductive polymer such as PMTFSI plasticized with at least one plasticizer such as triethyl phosphate.

[0120] Comparative Example 4: Preparation of polymer electrolytes EP14*, EP15*, and EP16* not conforming to the present invention

[0121] A plurality of polymer electrolytes containing PMMA as an ion-non-conductive non-fluorinated polymer instead of PVdF, PMTFSI as a cationic unipolar conductive polymer, and propylene carbonate as a plasticizer were prepared as detailed below.

[0122] The components (ionic non-conductive non-fluorinated polymer, cationic unipolar conductive polymer, and plasticizer) were mixed with acetonitrile (ACN) in a beaker at 100 °C under magnetic stirring (300 rpm). For 1 g of the mixture of the ionic non-conductive non-fluorinated polymer PMMA and the cationic unipolar conductive polymer, 1 g of the plasticizer and 5 g of acetonitrile were used. After mixing, the resulting mixture was coated on a silicone-coated polyethylene terephthalate (PET) support at room temperature at 8 mm / s to form a film, and then dried in a ventilation hood for several minutes to evaporate the residual acetonitrile.

[0123] Table 4 below shows the mass percentages of the various components present in the electrolytes prepared according to the above procedure, together with their thicknesses:

Table 4

[0124] Then, for each of these polymer electrolytes, a lithium electrolyte lithium (LEL) cell is manufactured by sequentially laminating a lithium foil, the polymer electrolyte membrane prepared as described above, and another lithium foil at 75 °C under dry air.

[0125] For the polymer electrolyte EP1* not conforming to the present invention, the lamination is carried out at a pressure of 2 bar. For other polymer electrolytes EP14* to EP16* not conforming to the present invention, the lamination is carried out at a pressure of 5 bar.

[0126] The cells LEL1*, LEL14*, LEL15*, and LEL16* each containing the polymer electrolytes EP1*, EP14*, EP15*, and EP16* are placed in a 2-bar compression system.

[0127] The ionic conductivities of the polymer electrolytes EP1*, EP14*, EP15*, and EP16* are measured as in Example 1.

[0128] Figure 4 shows the change in ionic conductivity (unit: S.cm -1 -1) as a function of temperature (measured as the ratio of 1000 / temperature, unit: Kelvin -1 ) for polymer electrolytes EP1* (the curve of black circles connected by solid lines), EP14* (the curve of black circles connected by wide dotted lines), EP15* (the curve of black circles connected by normal dotted lines), and EP16* (the curve of black circles connected by short dotted lines). Different from PVdF, when using PMMA, the ionic conductivity of the polymer electrolyte decreases.

[0129] Example 5: Preparation of cathode C1* not conforming to the present invention and cathode C2 conforming to the present invention

[0130] Preparation of cathodes C1* and C2 A first cathode (positive electrode) C1* conforming to the present invention in the form of a film (i.e., not containing PVdF as an ion-non-conductive fluoropolymer) was prepared as follows: 1.32 g of propylene carbonate (PC), 1.32 g of PMTFSI, and 12 g of ACN were mixed in a beaker under magnetic stirring at 300 rpm and at 100 °C. Then, when a uniform result was obtained, 4.2 g of lithium manganese iron phosphate (LMFP) and 0.17 g of carbon black (KB) were added. Then, the resulting mixture was pulverized using a ball mill at 30 rpm for 8 minutes. The resulting mixture was coated on a current collector known as "EnSafe 65" from Armor at room temperature at 30 mm / s to form a cathode, which was calendered at 95 °C to reduce the porosity. A thickness of 34 μm was obtained.

[0131] A second cathode C2 that does not conform to the form of the present invention (i.e., including PVdF as an ion-non-conductive fluoropolymer) was prepared as follows: 1.32 g of propylene carbonate (PC), 0.79 g of PMTFSI, 0.53 g of PVdF, and 18 g of ACN were mixed in a beaker under magnetic stirring at 300 rpm and at 100 °C. Then, when a uniform result was obtained, 4.2 g of lithium manganese iron phosphate (LMFP), and 0.17 g of carbon black (KB) were added. Then, the resulting mixture was milled using a ball mill at 30 rpm for 8 minutes. The resulting mixture was coated onto a current collector known as "EnSafe 65" from Armor at room temperature at 30 mm / s to form a cathode, which was calendered at 95 °C to reduce the porosity. A thickness of 40 μm was obtained.

[0132] Table 5 below shows the mass percentages of the various components present in the cathode prepared according to the above procedure:

Table 5

[0133] Preparation of Polymer Electrolyte EP17 Compatible with the Present Invention The EP17 polymer electrolyte compliant with the present invention, which contains PVdF as an ion-non-conductive fluoropolymer, PMTFSI as a cationic unipolar conductive polymer, and propylene carbonate as a plasticizer, was prepared as follows. The components (ion-non-conductive fluoropolymer, cationic unipolar conductive polymer, and plasticizer) were mixed with acetonitrile (ACN) in a beaker at 100 °C under magnetic stirring (300 rpm). For 1 g of the mixture of the ion-non-conductive fluoropolymer and the cationic unipolar conductive polymer, 1 g of the plasticizer and 5 g of acetonitrile are used. After mixing, the resulting mixture was first coated onto the first surface of a porous polypropylene separator with a thickness of 16 μm at room temperature at 8 mm / s to form a film, and then dried in a ventilation hood for several minutes to evaporate the residual acetonitrile. Then, the second surface of the porous separator is coated with the resulting mixture under the same conditions as the first coating.

[0134] Table 6 below shows the mass percentages of the various components present in the polymer electrolyte EP17 prepared according to the above procedure, together with their overall thickness:

Table 6

[0135] Performance of cathodes C1* and C2 For both cathodes C1* and C2, a 5 cm 2 cathode electrolyte cathode (CEC) cell is assembled with the EP17 polymer electrolyte. Cells CEC1 and CEC2 having cathodes C1* and C2 respectively are assembled by sequential lamination at 75 °C and 5 bar in dry air. These cells are placed in a 2-bar compression system.

[0136] For each of these two cells, impedance spectroscopy measurements are performed. The ionic conductivity of the electrolyte is measured by impedance spectroscopy. The measurements are carried out in a constant potential mode between 100 mHz and 1 MHz with an amplitude of 10 mV at 40 °C.

[0137] Figure 5 shows the reciprocal of the imaginary part Z” (unit: ohm) as a function of the real part Z’ (unit: ohm) for the cathode C1* (curve by dotted line) and the cathode C2 (curve by solid line). In Figure 5, the first semi-circle obtained at high frequency (HF) is due to the contribution of the polymer electrolyte + cathode solution, and the second semi-circle is due to the cathode / collector interface. The impedance of the contribution of the polymer electrolyte + cathode solution at high frequency is 490.9% higher for the cell CEC1 using the C1* cathode without PVDF. Since the polymer electrolyte EP17 is the same for both the CEC1 cell and the CEC2 cell, it can be concluded that the use of PVDF in the cathode based on LMFP and PMTFSI plasticized with PC contributes to the improvement of the ionic conductivity of the cathode solution.

[0138] Table 7 below lists the characteristic frequency (unit: KHz) of the high-frequency contribution and the impedance of the high-frequency contribution (unit: kΩ.cm 2 ) for each of the cathodes C1* and C2.

Table 7

[0139] Example 6: Fabrication of a battery according to the present invention

[0140] A lithium electrolyte cathode cell (LEC1) is made by · sequentially laminating at 75 °C and 5 bar a polymer electrolyte EP3’ that is compatible with the present invention and is identical to EP3 made in Example 1 except that the thickness is 18 μm instead of 34 μm, · a lithium metal anode with a thickness of 72 μm, and · a cathode C3 that is compatible with the present invention and then placed in a compression system of 2 bar. The cell LEC1 has a theoretical mass capacity of 5 mAh / g.

[0141] A cathode C3 conforming to the present invention in the form of a film was prepared in advance as follows: 1.32 g of propylene carbonate (PC), 1.06 g of PMTFSI, 0.26 g of PVdF, and 15 g of ACN were mixed in a beaker under magnetic stirring at 300 rpm and at 100 °C. Then, when a uniform result was obtained, 4.2 g of lithium iron manganese phosphate (LMFP) and 0.17 g of carbon black (KB) were added. The resulting mixture was then milled using a ball mill at 30 rpm for 8 minutes. The resulting mixture was coated onto a current collector known as "EnSafe 65" from Armor at room temperature at 30 mm / s to form a cathode, which was calendered at 95 °C to reduce the porosity. A thickness of 37 μm was obtained.

[0142] Table 8 below shows the mass percentages of the various components present in cathode C3 prepared according to the above procedure:

Table 8

[0143] Cycling at 40 °C was carried out according to the following procedure (a 3-hour pause is marked when the cell is placed in the oven): · First, activation is carried out for 10 hours by applying a voltage of 3.3 V (vs. Li / Li + ); · LEC1 performs an initial C / 10 charge at a cut-off voltage of 4.2 V (vs. Li / Li + ); · A voltage of 4.2 V (vs. Li / Li + ) is maintained for 1 hour and 30 minutes, followed by a D / 10 discharge at a cut-off voltage of 2.5 V (vs. Li / Li + ); · Following this first cycle, the battery cycles at C / 10 - D / 5. The cut-off voltages for charging and discharging remain at 4.2 V (vs. Li / Li + ) and 2.5 V (vs. Li / Li + ) respectively. Each charge is applied at 4.2 V (vs. Li / Li+ ) interrupted by the voltage of; · After 40 cycles, the applied cycle becomes C / 4 - D / 2.

[0144] After 358 cycles, the cell has a discharge capacity of 123 mAh / g and an efficiency equal to 99.8%.

[0145] Figure 6 shows the capacity of cell LEC1 (curve by black diamonds) as a function of the number of cycles (unit: mAh / g), and the efficiency of cell LEC1 (curve by black squares) as a function of the number of cycles (unit: %).

[0146] Figure 7 shows the internal resistance Ri (unit: Ohm.cm) of cell LEC1 as a function of the number of cycles in discharge (curve by black diamonds) and charge (curve by black squares). 2 )

[0147] Example 7: Fabrication of a battery according to the present invention

[0148] A lithium electrolyte cathode cell (LEC2) is · A polymer electrolyte EP17 as prepared in Example 5 conforming to the present invention, · A lithium metal anode with a thickness of 72 μm, and · A cathode C3 as prepared in Example 6 conforming to the present invention created by sequential lamination at 75 °C and 5 bar, and then placed in a compression system of 2 bar. Cell LEC2 has a theoretical mass capacity of 6 mAh / g.

[0149] Table 9 below shows the mass percentages of various components present in cathode C3 prepared according to the above procedure:

Table 9

[0150] The cycling procedure is the same as that described in Example 6, except that the applicable cycle is the end of the 7th cycle instead of the 40th cycle, where it becomes C / 4 - D / 2. A cycling procedure with this difference was implemented.

[0151] After 260 cycles, the cell has a discharge capacity of 123 mAh / g and an efficiency equal to 100%.

[0152] Figure 8 shows the capacity of cell LEC2 (curve by black diamonds) (unit: mAh / g) as a function of the number of cycles, and the efficiency of cell LEC2 (curve by black squares) (unit: %) as a function of the number of cycles.

[0153] Figure 9 shows the internal resistance Ri (unit: Ohm.cm 2 ) of cell LEC2 as a function of the number of cycles in discharge (curve by black diamonds) and charge (curve by black squares).

[0154] Example 8: Preparation of Polymer Electrolyte EP18 Compatible with the Present Invention

[0155] A polymer electrolyte containing PVdF - HFP as an ion - non - conductive fluoropolymer, PMTFSI as a cationic unipolar conductive polymer, and propylene carbonate as a plasticizer was prepared as detailed below.

[0156] The components (ion - non - conductive fluoropolymer, cationic unipolar conductive polymer, and plasticizer) were mixed with acetonitrile (ACN) in a beaker at 100 °C under magnetic stirring (300 rpm). For 1 g of the mixture of the ion - non - conductive fluoropolymer and the cationic unipolar conductive polymer, 1 g of the plasticizer and 5 g of acetonitrile were used. After mixing, the resulting mixture was coated on a silicone - coated polyethylene terephthalate (PET) support at room temperature at 8 mm / s to form a film, and then dried in a ventilation hood for several minutes to evaporate the residual acetonitrile.

[0157] Table 10 below shows the mass percentages of the various components present in the electrolyte created according to the above procedure, along with its thickness:

Table 10

[0158] Thus, two lithium electrolyte lithium (LEL) cells are manufactured by sequentially laminating a lithium foil, a polymer electrolyte membrane, and another lithium foil at 75 °C under dry air.

[0159] For the polymer electrolyte EP1* not conforming to the present invention, the lamination is performed at a pressure of 2 bar. For the polymer electrolyte EP18 conforming to the present invention, the lamination is performed at a pressure of 5 bar.

[0160] The cells LEL1* and LEL18 containing the polymer electrolytes EP1* and EP18 are placed in a 2-bar compression system.

[0161] The ionic conductivities of the polymer electrolytes EP1* and EP18 are measured as described in Example 1.

[0162] Figure 10 shows the change in ionic conductivity (unit: S.cm -1 )) as a function of temperature (measured as the ratio of 1000 / temperature, unit: Kelvin -1 ) for the polymer electrolytes EP1* (curve of black circles connected by solid lines) and EP18 (curve of black circles connected by dotted lines). The ionic conductivity of the polymer electrolyte is improved in the presence of PVdF-HFP as an ion-nonconductive fluoropolymer.

Claims

1. A polymer composition comprising at least one cationic unipolar conductive polymer, at least one plasticizer, and at least one ionic nonconductive fluoropolymer, wherein the cationic unipolar conductive polymer is a homopolymer or copolymer comprising at least one organic polymer chain, an organic anionic functional group that forms a covalent bond with the organic polymer chain, and a metal cation associated with the organic anionic functional group.

2. The aforementioned cationic unipolar conductive polymer is - A homopolymer that can be prepared from monomer a), wherein at least one organic anionic functional group is covalently grafted to the monomer and comprises at least one metal cation associated with the organic anionic functional group, or A copolymer that can be prepared from monomer a), wherein at least one organic anionic functional group is covalently grafted onto the monomer and includes at least one metal cation associated with the organic anionic functional group, and monomer b), which is different from monomer a), and is selected from monomer b1), wherein at least one organic anionic functional group is covalently grafted onto the monomer and includes at least one metal cation associated with the organic anionic functional group, and monomer b2). The polymer composition according to claim 1, characterized in that it is the same as the one described in claim 1.

3. The polymer composition according to claim 1 or 2, characterized in that the metal cation associated with the organic anionic functional group is selected from Li+ and Na+ cations.

4. The polymer composition according to claim 1 or 2, characterized in that the organic anionic functional group is bissulfonylimide.

5. The polymer composition according to claim 1 or 2, characterized in that the cationic unipolar conductive polymer is present in an amount of 5 to 40% by weight relative to the total weight of the polymer composition.

6. The polymer composition according to claim 1 or 2, characterized in that the ion-nonconductive fluoropolymer is present in an amount of 5 to 45% by weight relative to the total weight of the polymer composition.

7. The polymer composition according to claim 1 or 2, characterized in that the ion-nonconductive fluoropolymer is selected from vinyl fluoride (VF) homopolymers and copolymers, vinylidene fluoride (VdF) homopolymers and copolymers, tetrafluoroethylene (TFE) homopolymers and copolymers, chlorotrifluoroethylene (CTFE) homopolymers and copolymers, hexafluoropropylene (HFP) homopolymers and copolymers, and mixtures thereof.

8. The polymer composition according to claim 1 or 2, characterized in that the plasticizer is selected from linear and cyclic carbonates, fluorinated carbonates, nitriles, lactones, liquid linear and cyclic polyethers, fluorinated polyethers, sulfur-containing solvents, phosphates, esters, and mixtures thereof.

9. The polymer composition according to claim 1 or 2, characterized in that the plasticizer is present in an amount of 25 to 90% by weight relative to the total weight of the polymer composition.

10. Use of the polymer composition according to claim 1 or 2 for the preparation of a polymer electrolyte and / or positive electrode of a rechargeable battery.

11. A polymer electrolyte for rechargeable batteries, characterized by comprising the polymer composition described in claim 1 or 2, or a porous separator impregnated with the polymer composition described in claim 1 or 2.

12. A positive electrode for a rechargeable battery comprising a positive electrode active material and a polymer composition, and optionally comprising an electron conductivity generating agent, wherein the polymer composition is the polymer composition described in claim 1 or 2.

13. - A negative electrode containing lithium metal, sodium metal, lithium metal alloy, or sodium metal alloy, - The positive electrode is probably supported by a current collector, - A polymer electrolyte located between the positive electrode and the negative electrode A rechargeable lithium or sodium battery characterized by comprising: A rechargeable lithium or sodium battery characterized in that the polymer electrolyte is the polymer electrolyte described in claim 11, and the positive electrode is the positive electrode described in claim 12.

14. A negative electrode comprising lithium metal, sodium metal, a lithium metal alloy, or a sodium metal alloy, - The positive electrode is probably supported by a current collector, - A polymer electrolyte located between the positive electrode and the negative electrode A rechargeable lithium or sodium battery characterized by comprising: A rechargeable lithium or sodium battery characterized in that the polymer electrolyte is the polymer electrolyte described in claim 11.

15. A negative electrode comprising lithium metal, sodium metal, a lithium metal alloy, or a sodium metal alloy, - The positive electrode is probably supported by a current collector, - A polymer electrolyte located between the positive electrode and the negative electrode A rechargeable lithium or sodium battery characterized by comprising: A rechargeable lithium or sodium battery characterized in that the positive electrode is the positive electrode described in claim 12.

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