Method for producing lithium metal or an alloy thereof or for prelithiating an electrode material

Abstract

The invention relates to a relithiated lithium intercalation material for producing lithium metal or for prelithiating an electrode material, and to an anode and a production electrolytic cell comprising this material. The invention also relates to a method for producing lithium metal and for prelithiating an electrode material. This method comprises carrying out an electrolytic reaction for producing lithium in the electrolytic cell, wherein the electrolytic cell comprises the relithiated lithium intercalation material as an anode, a current collector as a cathode and an electrolyte comprising a lithium salt.

Description

TITLE PROCESS FOR THE PRODUCTION OF METALLIC LITHIUM OR AN ALLOY THEREOF, OR FOR THE PRE-LITHIATION OF AN ELECTRODE MATERIAL FIELD OF THE INVENTION

[0001] The present invention relates to a process for producing metallic lithium or an alloy thereof, or for pre-lithiating an electrode material. More specifically, the present invention relates to a process that enables, in some cases, the production of metallic lithium or an alloy thereof and, in other cases, the pre-lithiating of an electrode material, all starting from a lithium-relithiated intercalation material. CONTEXT OF THE INVENTION

[0002] The production of metallic lithium is traditionally carried out by electrolysis of LiCl in a molten saline solution at very high temperatures (typically between 400 and 450 °C). The electrolyte consists of a mixture of LiCl and KCl, forming a eutectic with a melting point of 355 °C and a composition of 45% LiCl and 55% KCl. This electrolyte is chemically resistant to the chlorine gas released at the anode during electrolysis and also allows current densities to be achieved on the order of several thousand A / m². 2However, despite the high productivity of the production cells, the process has several drawbacks. Electrolysis must be carried out at very high temperatures. The anodic reaction involves the release of chlorine, which is highly corrosive (especially at high temperatures). Furthermore, the metallic lithium produced is in liquid form at these high temperatures, making its handling more complicated due to its high reactivity in liquid form. The combination of high temperatures and the handling of corrosive chlorine gas and highly reactive liquid metallic lithium results in high investment and operating costs for this conventional process of metallic lithium production.Another disadvantage of this process is that, in the case of manufacturing lithium batteries based on metallic Li sheets as anode material, the resulting metallic Li ingot must be transformed into thin sheets using several extrusion and rolling steps, which increases investment and operating costs.

[0003] To lower the electrolysis temperature and avoid handling liquid metallic lithium, it has been proposed to perform electrodeposition of lithium in ionic liquids that are liquid at room temperature (RTIL). However, the proposed approach does not address the issue of achieving an anodic reaction that will not lead to degradation of the electrolysis medium.

[0004] The use of metallic Li as an anode material has been proposed to avoid electrolyte degradation during the anodic reaction in the electrodeposition of metallic Li. This approach has been applied both to the production of Li thin films on current collectors and to the pre-lithiation of anodic materials (such as graphite, silicon, etc.). However, this approach, which relies on on the oxidation of Li as an anodic compatible reaction always involves the use of metallic Li which has been produced using the conventional high-temperature process using LiCl as the starting raw material.

[0005] Bodoin et al. (US 2022 / 0367874 A1) and Kang et al. (2021 / 0381115 A1) proposed the use of an electrolysis cell with a lithium-selective ceramic membrane that separates the anodic compartment containing an aqueous solution of a lithium salt from the cathodic compartment containing an organic solvent with another lithium salt. This process offers several advantages, namely that it avoids an anodic reaction incompatible with the electrolysis media (in this case, the anodic reaction is the release of oxygen in aqueous media), the electrolysis is carried out at low temperature, and the raw material for the production of metallic lithium can be any lithium salt, such as lithium carbonate.However, the proposed approach also has several important drawbacks such as the use of expensive and fragile ceramic membranes and the leakage of water molecules through the ceramic membrane into the organic electrolyte and the consequent contamination of metallic lithium by LiOH.

[0006] On another topic, next-generation energy storage technologies require advanced active electrode materials with improved gravimetric and volumetric capacities to achieve higher gravimetric and volumetric energy densities. However, most of these materials suffer from high losses of active lithium during the first cycle, caused, for example, by the formation of solid electrolyte interphases (SEIs), which has thus far hindered their widespread commercial use. Indeed, during the initial charging of the fuel cell, a certain amount of active lithium is lost, reducing the remaining active lithium content. In general, this loss of active lithium permanently decreases the available energy due to the lithium consumption by the electrode material.Prelithiation is considered a very promising technique for compensating for losses of active lithium and, consequently, for increasing practical energy density. Prelithiation is the addition / doping of lithium to a battery electrode before the battery cells begin operation. Prelithiation can effectively compensate for lithium loss during the first cycle and improve initial Coulomb efficiency. It is a general method that can be applied to all kinds of electrode materials and improve battery performance. Various prelithiation techniques have been evaluated to date, including electrochemical and chemical prelithiation, prelithiation using additives, and prelithiation by direct contact with metallic lithium.

[0007] In electrochemical pre-lithiation processes, the lithium source consists of a metallic lithium electrode coupled to a lithium intercalation material. Under the application of a current, the metallic lithium oxidizes and migrates to the opposite electrode, where it intercalates into the lithium intercalation material. Such a method is applied to the pre-lithiation of a silicone intercalation material by Park et al. (WO 2019 / 113534 A1). In this patent application, the use of a metallic lithium counter-electrode increases costs and still involves the aforementioned problems related to the use of highly reactive metallic lithium.

[0008] To avoid the problems associated with using metallic lithium as a lithium source for prelithiation, Grant et al. (US 9 598 789 B2) developed an anode prelithiation process using a lithium salt dissolved in the electrolyte as the lithium source, specifically LiCl. In this patent, the metallic lithium counter electrode is replaced by an inert metal foil where anodic electrolyte degradation reactions, such as chlorine release, are expected. Such a system promotes electrolytic salt degradation, high energy consumption, and limited current density. SUMMARY OF THE INVENTION

[0009] In accordance with the present invention, it is provided that: 1. Li-lithiated intercalation material for producing metallic Li or an alloy thereof or for pre-lithiating an electrode material. 2. Use of a relithi-treated Li intercalation material to produce metallic Li or an alloy thereof or to pre-lithiate an electrode material. 3. The material / use according to embodiment 1 or 2, for producing metallic Li or its alloy, preferably for producing metallic Li, preferably wherein the metallic Li or its alloy is in the form of a film, preferably wherein the metallic Li or its alloy is produced by electrodeposition. 4. The material / use according to embodiment 1 or 2, for pre-lithing an electrode material, preferably for pre-lithing an anode material, more preferably for pre-lithing graphite, Si, a silicon oxide (SiO₂) x ), a silicon-carbon composite, carbon nanotubes, or a mixture thereof. 5. The material / use according to any one of embodiments 1 to 4, wherein the intercalation material of the relithié Li is a lithium phosphate or a lithium oxide, preferably: • Li w FePO4 (where w < 1, 1, preferably w is 1), • Li w Fei-xMn x PO4 (in which w < 1, 1, preferably w is 1; 0 < x < 1, preferably 0.2 < x < 0.4), • Li w Mn2O4 (in which ws 1 ,1, preferably w is 1), • LiwMn15Nio5O4 (where w < 1.1, preferably w is 1), • Li4+ z Tis012 (where 0 < z < 3), or • NMC (Li w Nii- x -yMnxCoyO2, in which w < 1,3, preferably w is 1; 0 S x ^ 1, 0 S y < 1, and 0 S z < 1, and M is Al, Mg, Ti, Nb, Zr, W, Mo, Y, La, Ta or one of their mixtures). 6. The material / use according to embodiment 5, in which the intercalation material of relithié Li is Liw FePO4. The material / use according to any one of embodiments 1 to 6, wherein the relithiated Li intercalation material was obtained from spent electrodes and then relithiated, or wherein the relithiated Li intercalation material was used to produce metallic Li or an alloy thereof, or to prelithiate an electrode material, and then relithiated. The material / use according to any one of embodiments 1 to 7, wherein the relithiated Li intercalation material has recovered at least 50%, preferably at least 75%, more preferably at least 85%, even more preferably at least 95%, and even more preferably at least 99% of the previously deintercalated lithium ions. A production anode for producing metallic Li or an alloy thereof, or for prelithiating an electrode material, the production anode comprising a relithiated Li intercalation material.Use of a production anode comprising a relithiated Li intercalation material for producing metallic Li or an alloy thereof, or for pre-lithiating an electrode material. The production anode / use according to embodiment 9 or 10, wherein the relithiated Li intercalation material is as defined in any one of embodiments 1 to 8. The production anode / use according to any one of embodiments 9 to 11, intended for producing metallic Li or an alloy thereof, preferably intended for producing metallic Li, preferably wherein the metallic Li or its alloy is in the form of a film, preferably wherein the metallic Li or its alloy is produced by electrodeposition. The production anode / use according to embodiment 12, wherein the anode is intended for an electrolytic reaction for the production of Li.The production / use anode according to embodiment 12 or 13, wherein the production anode further comprises a current collector and the relithiated Li intercalation material is deposited on the current collector. The production / use anode according to embodiment 14, wherein the current collector is a metal foil, preferably made of Cu, Al, stainless steel, Ti, or Ni, or is made of a conductive carbon material, or is a polymer-based current collector. The production / use anode according to embodiment 14 or 15, wherein the current collector is coated with a primer layer, such as a carbon-containing paint. The production / use anode according to any one of embodiments 14 to 16, wherein the current collector is a metal foil made of stainless steel or Al, preferably a current collector comprising a carbon-coated Al foil.The production / use anode according to any one of embodiments 9 to 11, intended for pre-lithing an electrode material, preferably intended for pre-lithing an anode material, more preferably. intended for pre-lithing graphite, Si, a silicon oxide (SiO₂) x), a silicon-carbon composite, carbon nanotubes, or a mixture thereof. The production anode / use according to any one of embodiments 9 to 18, wherein the production anode is in the form of a film. Production electrolysis cell for producing metallic Li or an alloy thereof or for prelithiating an electrode material, the production electrolysis cell comprising: a relithiated Li intercalation material used as a production anode, a current collector or said electrode material used as a production cathode, and a production electrolyte between the production cathode and the production anode, wherein the production electrolyte comprises a production lithium salt dissolved in a production solvent.Use of a production electrolysis cell for producing metallic Li or an alloy thereof, or for pre-lithitizing an electrode material, wherein the production electrolysis cell comprises: a relithiated Li intercalation material used as a production anode, a current collector or said electrode material used as a production cathode, and a production electrolyte between the production cathode and the production anode, wherein the production electrolyte comprises a production lithium salt dissolved in a production solvent. The production electrolysis cell / use according to embodiment 20 or 21, wherein the relithiated Li intercalation material is as defined in any one of embodiments 1 to 8.The production / use electrolysis cell according to any one of embodiments 20 to 22, wherein the production anode is as defined in any one of embodiments 9 to 19. The production / use electrolysis cell according to any one of embodiments 20 to 23, intended for the production of metallic Li or its alloy, preferably intended for the production of metallic Li, preferably wherein the metallic Li or its alloy is in the form of a film, preferably wherein the metallic Li or its alloy is produced by electrodeposition, and wherein the current collector is used as the production cathode. The production / use electrolysis cell according to embodiment 24, wherein the current collector used as the production cathode is in the form of a sheet.The production / use electrolysis cell according to embodiment 24 or 25, in which operating conditions, such as agitation and / or temperature control, are used. to modify the morphology of said metallic Li produced or its alloy. The production / use electrolysis cell according to any one of embodiments 24 to 26, wherein the current collector used as the production cathode is made of Cu, Al, protected aluminum, C, stainless steel, Ti, Zn, or Ni or one of their alloys, or is a current collector based on a metallized polymer, or a mixture thereof. The production / use electrolysis cell according to any one of embodiments 24 to 27, wherein the current collector used as the production cathode is made of Cu or protected Al. The production / use electrolysis cell according to any one of embodiments 24 to 28, wherein the current collector used as the production cathode is protected by a protective layer.The production / use electrolysis cell according to any one of embodiments 24 to 28, wherein the current collector used as the production cathode is not protected. The production / use electrolysis cell according to any one of embodiments 24 to 30, wherein the surface of the current collector used as the production cathode is treated or modified to improve its lithiophilicity. The production / use electrolysis cell according to any one of embodiments 24 to 31, wherein the surface of the current collector used as the production cathode is treated or modified to have a 3D structure to improve the electrochemical performance of the Li layer in a battery or to increase its reaction rate, for example, when used for the preparation of an organolithium compound.The production / use electrolysis cell according to any one of embodiments 24 to 32, intended for producing said alloy; preferably, the alloy comprising about 80% w / w or more of Li, more preferably about 85% w / w or more of Li, even more preferably about 90% w / w or more of Li, even more preferably about 95% w / w or more of Li, based on the total weight of the alloy. The production / use electrolysis cell according to embodiment 33, wherein the production electrolyte further comprises an alloying salt, the alloying salt preferably being a salt of one or more of the following elements: Na, K, Mg, Ca, a transition metal, Al, Ga or Sn, preferably a salt of Al or Mg.The production / use electrolysis cell according to embodiment 34, wherein the alloying salt is a (fluorosulfonyl)(trifluoromethanesulfonyl)imide salt, a 2-trifluoromethyl-4,5-dicyanoimidazolate (TDI) salt, a 4,5-dicyano-1,2,3-triazolate (DCTA) salt, a bis(pentafluoroethylsulfonyl)imide (BETI) salt, a difluorophosphate (DFP) salt, a chloride salt, a bromide salt, a fluoride salt, a hexafluoroarsenate (AsFe) salt, a fluoroalkylphosphate salt, a tetrakis(trifluoroacetoxy)borate salt, a bis(1,2-) salt. benzenediolato(2-)-O,O')borate, a difluoro(oxalato)borate salt, a nitrate salt, a trifluoroacetate salt, a hexafluorophosphate salt, a tetrafluoroborate salt, a bis(oxalate)borate (BOB) salt, a perchlorate salt, a bis(trifluoromethanesulfonyl)imide (TFSI), a bis(fluorosulfonyl)imide (FSI) salt, a tritiate salt, or a salt with an anion of the formula: BF2O4R (x = C2-4 alkyl). The production / use electrolysis cell according to any one of embodiments 24 to 32, wherein the production electrolyte is free of alloying salt and the production / use electrolysis cell is intended to produce metallic Li.The production / use electrolysis cell according to any one of embodiments 20 to 23, intended for pre-lithing an electrode material, preferably intended for pre-lithing an anode material, more preferably intended for pre-lithing graphite, Si, a silicon oxide, or a mixture thereof, and wherein said electrode material is used as a production cathode.The production / use electrolysis cell according to any one of embodiments 20 to 37, wherein the lithium salt of production is lithium (fluorosulfonyl)(trifluoromethanesulfonyl)imide, lithium 2-trifluoromethyl-4,5-dicyanoimidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium bis(pentafluoroethylsulfonyl)imide (LiBETI), lithium difluorophosphate (LiDFP), lithium chloride (LiCl), lithium bromide (LiBr), lithium hexafluoroarsenate (LiAsFe-), a lithium fluoroalkylphosphate [such as LiPF3(CF2CF3)3], lithium tetrakis(trifluoroacetoxy)borate (LiB(OCOCF3)4), bis(1,2-benzenediolato (2-)-O,O')lithium borate LiB(CeO2)2, lithium difluoro(oxalato)borate (LiBF2(C2C>4)), a compound of formula BF2O4R (R. x(= C2-4 alkyl), UCF3COO, LiF, UNO3, LiPFe, UBF4, LiBOB, UCIO4, LiTFSi, CF3SO3U, LiFSi, or any combination thereof, preferably UCF3COO, LiF, UNO3, LiPFe, UBF4, LiBOB, UCIO4, LiTFSi, CFsSOsLi, LiFSi, or any combination thereof. The production / use electrolysis cell according to embodiment 38, wherein the lithium salt of production is a combination of CF3SO3U and LiFSi.The production / use electrolysis cell according to any one of embodiments 20 to 39, wherein the production electrolyte further comprises one or more additives, preferably one or more additives that modify the morphology and / or properties of metallic Li or its alloy, one or more additives that influence the phase nucleation energy, one or more additives that influence a deposition potential of lithium or its alloy, and / or one or more additives that influence the electrodeposition efficiency of Li; more preferably, the additive(s) are: an unsaturated cyclic carbonate such as vinylene carbonate (VC), a halogenated cyclic carbonate such as fluoroethylene carbonate (FEC), a nitrate, a Li polymerization agent comprising a saturated or unsaturated hydrocarbon chain. such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), a Li passivation compound, and / or an alkali salt of an organic acid, such as lithium difluoro(oxalate)borate (LiDFOB) or Li oxalate. The production / use electrolysis cell according to any one of embodiments 20 to 40, wherein the production solvent is an organic carbonate, an organic ester, an organic ether, an ionic liquid, or any combination thereof.The production / use electrolysis cell according to embodiment 41, wherein the production solvent is ethylene carbonate (EC), propylene carbonate (PC), fluoroethylene carbonate (FEC), gamma-butyrolactone (gBL), ethyl propionate, diethyl carbonate (DEC), dimethyl carbonate (DMC), ethylmethyl carbonate (EMC), dimethoxyethane (DME), fluoroether, tetrafluoroethyltetrafluoropropylether (TTE), tetraethylene glycol dimethyl ether (TEGDME), or any combination thereof. The production / use electrolysis cell according to embodiment 42, wherein the production solvent is a combination of EC and DEC. The production / use electrolysis cell according to any one of embodiments 20 to 43, wherein the production electrolysis cell is free of a membrane separating the production anode from the production cathode.The production / use electrolysis cell according to embodiment 44, wherein the production electrolysis cell is in a roll-to-roll configuration. The production / use electrolysis cell according to embodiment 44 or 45, wherein the production electrolysis cell further comprises one or more calendering devices, such as pairs of calendering rollers, for example at fixed intervals.A process for the production of metallic Li or an alloy thereof or for pre-lithiating an electrode material, the process comprising: a) supplying a relithiated Li intercalation material, and b) carrying out an electrolytic reaction for the production of Li in a production electrolysis cell, wherein the production electrolysis cell comprises: said relithiated Li intercalation material as a production anode, a current collector or said electrode material as a production cathode, and a production electrolyte between the production cathode and the production anode, wherein the production electrolyte comprises a production lithium salt dissolved in a. production solvent, thus enabling the electrodeposition of metallic Li or an alloy thereof onto the current collector used as the production cathode, or the introduction of lithium into said electrode material, thereby producing a pre-lithianed electrode and thus enabling the production of a partially or completely lithiated Li intercalation material. A process according to embodiment 47, wherein the lithiated Li intercalation material is as defined in any one of embodiments 1 to 8. A process according to embodiment 47 or 48, wherein the production anode is as defined in any one of embodiments 9 to 19. A process according to any one of embodiments 47 to 49, wherein the production electrolysis cell is as defined in any one of embodiments 20 to 46.A method according to any one of embodiments 47 to 50, wherein the electrolytic reaction for the production of Li is carried out by regulating the cell potential either between the production anode and the production cathode, or between the cathode and a reference electrode. A method according to any one of embodiments 47 to 50, wherein the electrolytic reaction for the production of Li is carried out by regulating the cell current. A method according to embodiment 52, wherein the electrolytic reaction for the production of Li in regulated current mode is carried out in direct mode, in pulsed mode, either simple (unidirectional) or reverse. A method according to embodiment 52 or 53, wherein the electrolytic reaction for the production of Li in regulated current mode is carried out at a fixed frequency or at a variable frequency. A method according to any one of embodiments 47 to 54, wherein step a) is carried out in a roll-to-roll configuration.A process according to any one of embodiments 47 to 55, wherein step b) is carried out in a roll-to-roll configuration. A process according to any one of embodiments 47 to 56, wherein the partially or completely delithiated Li intercalation material is a partially or completely delithiated lithium phosphate or lithium oxide, preferably Li. w FePC>4, LiwM^C , Li4+ z TisOi2, or NMC (Li w Nii- x - y Mn x Co y M z O2) partially or completely delithiated. Process according to embodiment 57, wherein the partially or completely delithiated Li intercalation material is Li w FePC>4 partially or completely delithiated. Process according to any one of embodiments 47 to 58, wherein the delithiated Li intercalation material is washed, preferably washed and dried, before being used in step b). A method according to any one of embodiments 47 to 59, wherein step a) comprises: a') supplying a partially or completely delithiated Li intercalation material and a") relithiation of the partially or completely delithiated Li intercalation material, thereby producing a relithiated Li intercalation material. A method according to embodiment 60, further comprising step c) repeating steps a) and b) one or more times, using in steps a') and a") the partially or completely delithiated Li intercalation material produced in step b). A method according to embodiment 60 or 61, wherein the partially or completely delithiated Li intercalation material supplied in step a') is the partially or completely delithiated Li intercalation material produced in step b).A process according to any one of embodiments 47 to 60, wherein the partially or completely delithiated Li intercalation material is obtained from recycled used batteries. A process according to any one of embodiments 47 to 63, wherein step a”) comprises carrying out an electrolytic relithiation reaction in a relithiation electrolysis cell, wherein the relithiation electrolysis cell comprises: the partially or completely delithiated intercalation material as a relithiation cathode, a relithiation anode, and a relithiation electrolyte between the relithiation cathode and the relithiation anode, wherein the relithiation electrolyte comprises a relithiation lithium salt dissolved in a relithiation solvent, thereby enabling the partially or completely delithiated intercalation material to be relithied and the relithiated Li intercalation material to be produced.A process according to embodiment 64, wherein the relithiation solvent is water. A process according to embodiment 64 or 65, wherein the relithiation anode is made of a material compatible with the anodic reaction taking place at the relithiation anode, preferably compatible with an oxygen-evolution reaction. A process according to any one of embodiments 64 to 66, wherein the relithiation anode is made of lead, platinum, titanium, another inert metal, or an alloy thereof, or graphite. A process according to any one of embodiments 64 to 67, wherein the relithiation anode is a dimensionally stable anode. A process according to any one of embodiments 64 to 68, wherein the relithiation electrolyte. further comprises one or more additives; preferably one or more additives that improve the electrical conductivity properties of the relithiation electrolyte; more preferably a salt comprising an alkali cation other than Li or an alkaline earth cation (preferably potassium or magnesium) and an anion compatible with the relithiation electrolysis reaction (preferably sulfate or bicarbonate). A process according to any one of embodiments 64 to 69, wherein the relithiation salt is Li₂C₃, UHCO₃, LiOH, U₂O₃, LiOH, U₂SO₄, UCH₃COO, LiFSI, LiTFSI, or U₂C₂O₄, or a mixture thereof, preferably the relithiation salt is UHCO₃, U₂SO₄, or a mixture thereof, preferably the relithiation salt is U₂SO₄. A process according to any one of embodiments 64 to 70, wherein the relithiation salt is an inexpensive lithium salt.A process according to any one of embodiments 64 to 71, wherein the relithiation solvent is water, and the relithiation salt is a water-soluble relithiation salt. A process according to any one of embodiments 64 to 72, wherein the relithiation salt is a water-soluble relithiation salt that has a water solubility greater than the water solubility of UHCO3. A process according to embodiment 73, wherein the water-soluble relithiation salt that has a water solubility greater than the water solubility of UHCO3 is UNO3, U2SO4, or UHC3COO. A process according to any one of embodiments 64 to 74, wherein further comprising a step of producing the relithiation salt in the relithiation electrolysis cell.A method according to embodiment 75, comprising adding a lithium precursor and a reagent to the relithiation electrolysis cell and allowing the lithium precursor and reagent to react to form the relithiation salt. A method according to embodiment 76, wherein the lithium precursor and reagent are added to a salt-forming compartment of the relithiation electrolysis cell that is in fluidic communication with a main compartment of the relithiation electrolysis cell; the main compartment comprising the relithiation cathode and the relithiation anode. A method according to any one of embodiments 64 to 74, wherein the relithiation salt is prepared before being added to the relithiation electrolysis cell.A process according to embodiment 78, further comprising the reaction of a lithium precursor and a reagent in a reactor separate from the relithiation electrolysis cell to obtain the relithiation salt, and then adding the relithiation salt to the relithiation electrolysis cell. A process according to any one of embodiments 76, 77, and 79, wherein the lithium precursor is... IJ2CO3, LiOH, or a mixture thereof, preferably U2CO3. A process according to any one of embodiments 76, 77, and 79-80, wherein the reagent is CO2, H2SO4, nitric acid, acetic acid, oxalic acid, or an acidic form of a sulfonylurea salt, or a mixture thereof, preferably CO2 or H2SO4, or a mixture thereof. A process according to embodiment 81, wherein the reagent is CO2. A process according to embodiment 81, wherein the reagent is H2SO4. A process according to any one of embodiments 64 to 83, wherein the electrolytic relithiation reaction is carried out by regulating the cell potential either between the relithiation anode and the relithiation cathode, or between the relithiation cathode and a reference electrode. A method according to any one of embodiments 64 to 83, in which the electrolytic relithiation reaction is carried out by regulating the cell current.A process according to embodiment 85, wherein the electrolytic reaction in regulated current mode can be carried out in direct mode, in pulsed mode, either simple (unidirectional) or reverse. A process according to embodiment 85 or 86, wherein the electrolytic reaction in regulated current mode can be carried out at a fixed frequency or under a variable frequency. A process according to any one of embodiments 47 to 63, wherein step (a) comprises (i) adding the partially or completely delithiated intercalation material to a solution containing a reducing agent and a relithiation salt in a solvent; thereby enabling the partially or completely delithiated intercalation material to be relithied and the relithiated Li intercalation material to be produced.A process according to embodiment 88, further comprising (ii) separating the relithiated Li intercalation material from the solution; and (iii) electrochemically treating the solution separated in step (ii) to regenerate the reducing agent. A process according to embodiment 88 or 89, wherein the relithiation salt is as described in any one of embodiments 70 to 74. A process according to any one of embodiments 88 to 90, wherein the reducing agent is a reducing member of a redox couple having a redox potential lower than the redox potential of the partially or completely relithied intercalation material. A process according to embodiment 91, wherein the redox couple comprises an Fe(III) / Fe(II) complex. A process according to embodiment 92, wherein the redox couple is [Fe(CN)6]. 3 7Fe(CN)6] 4 ', [Fe(nta)] / [Fe(nta)]-, [Fe(tdpa)] 2 7Fe(tdpa)] 3 -, [Fe(edta)]7[Fe(edta)] 2-, [Fe(citrate)] / [Fe(citrate)]-, [Fe(lll)-TEA] / [Fe(ll)- TEA] ou [Fe(oxalate)]7[Fe(oxalate)]. A process according to any one of embodiments 88 to 93, wherein step (i) further comprises deoxygenation of the solution. A process according to any one of embodiments 88 to 94, wherein steps (i) and / or (iii) are carried out in the absence of oxygen. A process according to any one of embodiments 88 to 95, further comprising pH adjustment of the solution. A process according to any one of embodiments 88 to 96, wherein the solvent is an aqueous solvent. A process according to any one of embodiments 88 to 97, wherein step (iii) is carried out in an electrolytic cell by passing a current between at least one cathode and at least one anode. A process according to embodiment 98, wherein the electrolytic cell comprises at least one ionic or non-ionic separator installed between the anode and the cathode to protect the regenerated reducing agent.A process according to embodiment 98 or 99, wherein the electrolytic cell further comprises a system for maintaining the deoxygenated solution. A process according to any one of embodiments 98 to 100, wherein step (iii) is carried out by regulating the cell potential either between the anode and the cathode, or between the cathode and a reference electrode. A process according to any one of embodiments 98 to 100, wherein step (iii) is carried out by regulating the cell current. A process according to embodiment 102, wherein the current-regulated relithiation reaction is carried out in direct mode, in pulsed mode, either simple (unidirectional) or reverse. A process according to embodiment 102 or 103, wherein the current-regulated relithiation reaction is carried out at a fixed frequency or at a variable frequency.A method according to any one of embodiments 47 to 104, further comprising washing and drying the current collector with the metallic Li or its alloy or the pre-lithiated electrode produced in step b). A method according to any one of embodiments 47 to 105, further comprising using the current collector with the metallic Li or its alloy or the pre-lithiated electrode as the negative electrode in a primary or secondary Li battery, preferably a lithium-ion battery or an all-solid-state battery, as a source of metallic Li or its alloy for pre-lithiating an electrode material, or as a source of metallic Li or its alloy for manufacturing an energy storage system. A method according to any one of embodiments 47 to 106, further comprising rolling the. A current collector with metallic Li or its alloy to modify the morphology, density, or thickness of a film of metallic Li or its alloy. A method according to any one of embodiments 47 to 107, further comprising treating the current collector with metallic Li or its alloy to obtain a 3D structure. A method according to any one of embodiments 47 to 108, further comprising treating the current collector with metallic Li or its alloy to improve its electrochemical performance in batteries. A method according to any one of embodiments 47 to 105, further comprising using the current collector with metallic Li or its alloy as a lithium source to produce an organolithium compound.A process according to embodiment 110, wherein metallic Li or its alloy is reacted with a reagent, such as an alkyl halide, to produce the organolithium compound. A process according to embodiment 111, further comprising transferring the current collector with the metallic Li or its alloy produced in step b) to a separate reactor, preferably in roll-to-roll mode, and reacting the metallic Li or its alloy with the reagent in said separate reactor to produce the organolithium compound. A process according to any one of embodiments 47 to 112 for pre-lithiating an electrode material, preferably for pre-lithiating an anode material, more preferably for pre-lithiating graphite, Si, or silicon dioxide (SiO). xA silicon-carbon composite, carbon nanotubes, or a mixture thereof, wherein said electrode material is used as a production cathode. A process according to any one of embodiments 47 to 112 for producing metallic Li or an alloy thereof, preferably for producing metallic Li, preferably wherein the metallic Li or its alloy is produced by electrodeposition, and wherein the current collector is used as a production cathode. A process according to embodiment 114, wherein the metallic Li or its alloy is electrolytically deposited on the current collector in the form of a film, preferably of high purity. A lithium electrode comprising a current collector with metallic Li or an alloy thereof as produced by the process according to any one of embodiments 47 to 115.A lithium battery comprising the lithium electrode of embodiment 116, preferably in which the battery is a lithium-ion battery or an all-solid-state battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In the attached drawings: Figure 1 is a diagram of an embodiment of the process of the invention using UHCO3 as a relithiation salt. Figure 2 is a diagram of an embodiment of the process of the invention using U2SO4 as a relithiation salt. Figure 3 shows a bifacial production electrolysis cell with a multilevel electrolysis configuration. Figure 4 shows the cell potential as a function of time (upper black line) of the galvanostatic electrodeposition of metallic lithium described in Example 4. The lower gray line represents the applied current density. Figure 5 shows the cell potential as a function of time (top black line) of the galvanostatic electrodeposition of metallic lithium in the button cell of Example 5. The bottom gray line represents the applied current density. Figure 6 shows the chronocoulometry of the relithiation process of delithiated LiFePCU (FP) to relithiated LiFePCU (LFP). Note that delithiated LiFePCU is also sometimes referred to here as FePCU (despite the fact that it may contain residual lithium) or FP. Figure 7 shows the comparison of X-ray diffraction spectra of a virgin LFP electrode, an FP electrode before relithiation and an LFP electrode after relithiation. Figure 8 shows the comparison of cycling stability between cells with commercially available physical vapor deposition (PVD) Li as anode (triangles) and cells (in duplicate) with electrolytically deposited lithium (LiED) (obtained from Example 4) as anode (squares and diamonds). Figure 9 shows the cell potential as a function of time (upper black line) for the galvanostatic electrodeposition of metallic lithium. The lower gray line represents the applied current density. Figure 10A shows the appearance of the electrodeposited lithium from Example 7 before calendering. Figure 10B shows the appearance of the electrodeposited lithium from example 7 after calendering. Figure 11 shows a scanning electron microscope (SEM) micrograph of a cross-section of electrodeposited and calendered lithium from Example 7. The thicker top layer, corresponding to the electrodeposited lithium, has a thickness of 7.52 pm, while the thinner bottom layer, corresponding to the copper foil, has a thickness of 3.37 pm. Figure 12 compares the cycling stability of electrodeposited Li from Example 7 and a PVD-prepared Li sheet. Figure 13 compares the cycling stability of Li electrodeposited on various current collectors. Figure 14 shows the cell potential as a function of time (upper black line) of the galvanostatic electrodeposition of metallic lithium in Example 8.1. The lower grey line represents the applied current density. Figure 15 shows the cell potential as a function of time (upper black line) of the galvanostatic electrodeposition of metallic lithium in Example 8.2. The lower grey line represents the applied current density. Figure 16 shows the cell potential as a function of time (top black line) of the galvanostatic electrodeposition of metallic lithium in Example 8.3. The bottom grey line represents the applied current density. Figure 17 shows the cell potential as a function of time (top black line) of the galvanostatic electrodeposition of metallic lithium in Example 9. The bottom gray line represents the applied current density. Figure 18 shows the appearance of the electrodeposited lithium from example 9. Figure 19 shows the cell potential as a function of time (top black line) of the galvanostatic relithiation of delithiated LFP to form LFP in Example 10. The bottom grey line represents the applied current density. Figure 20 shows the FTIR spectra of the delithiated (FP) and relithiated (LFP) electrode of Example 10. Figure 21 shows the cell potential as a function of electrodeposition time (Li ED) for Example 10 (Li ED from a relithied LFP, solid line) and Example 8.2 (Li ED from a blank LFP, dashed line). Figure 22 shows the evolution of the LTO working electrode potential during relithiation in Example 11. Figure 23 shows the linear sweep anodic current voltammetry curve of the relithied LTO electrode in Example 11. Figure 24 compares the effect of various additives added to the electrolyte during the electrodeposition of Li. Figure 25 shows the titration curve developed to determine the concentration of n-butyllithium in n-hexane (example 13). Figure 26 shows the galvanostatic pre-lithiation of graphite anodes with an LFP counter electrode as the Li source. Figure 27 shows the galvanostatic pre-lithiation of SiOx anodes with an LFP counter electrode as a Li source. Figure 28 compares the potential curves as a function of the charge of the 1 er formation cycle for the fresh graphite anode and the pre-lithianed one. Figure 29 compares the potential curves as a function of the charge of the 1 er formation cycle for the fresh SiOx anode and the pre-lithiated one. DETAILED DESCRIPTION OF THE INVENTION

[0011] Turning now to the invention in more detail, the invention relates to a relithiated Li intercalation material for producing metallic Li or an alloy thereof, or for pre-lithiating an electrode material. In a related aspect, the invention relates to the use of a relithiated Li intercalation material for producing metallic Li or an alloy thereof, or for pre-lithiating an electrode material.

[0012] In embodiments of the invention, the material / use is for producing metallic Li or its alloy. In some embodiments, metallic Li is produced. In other embodiments, the alloy is produced. In preferred embodiments, the metallic Li or its alloy is in the form of a film. Preferably, the metallic Li or its alloy is produced by electrodeposition.

[0013] In embodiments of the invention, the material / use is for pre-lithiating an electrode material. The electrode material can be any electrode material capable of undergoing loss of active lithium during the first operating cycle of a battery. In some embodiments, the electrode material is graphite, silicon dioxide (SiO₂), or silicon dioxide (SiO₂). x ), a silicon-carbon composite, carbon nanotubes, or a mixture of these.

[0014] Here, a "Li intercalation material" is a material used for the reversible inclusion of the Li ion (Li + ) in its structure. Such materials are commonly used, for example in the manufacture of cathodes for Li-ion batteries. The intercalation of Li ions + In such materials, the process will be called "lithiation" of the material. The deintercalation of Li ions +Such materials will be referred to here as "delithiation." Delithiation can be partial or complete. Complete delithiation means that all Li+ ions that could deintercalate under any specific set of applied conditions have done so. Partial delithiation means that only some of these ions are deintercalated.

[0015] Here, "relithiation" simply refers to the lithiation of a Li intercalation material after its partial or complete delithiation. Therefore, a "relithiated Li intercalation material" is a partially or completely delithiated Li intercalation material that has undergone relithiation.

[0016] An example of a partially or completely delithiated Li intercalation material is a Li intercalation material that is degraded by loss of Li. Such a material is produced for the process of the invention and can be relithied and used again in the process of the invention. Such delithiated Li intercalation materials are also found, for example, in spent cathodes of used Li-ion batteries, where they cause a degradation of capacity. When a partially or completely delithiated Li intercalation material is relithied, it recovers at least some of its lithium ions and thus some of its electrochemical properties. Preferably, the relithied Li intercalation material recovers at least 50%, preferably at least 75%, more preferably at least 85%, even more preferably at least 95%, and even more preferably at least 99% of the previously deintercalated lithium ions.

[0017] The intercalation material of relithié Li is not particularly limited.

[0018] In some embodiments, the intercalating material for the relithiated Li is lithium phosphate or lithium oxide. In preferred embodiments, the intercalating material for the relithiated Li is: • Li w FePO4 (where w < 1, 1, preferably w is 1), • Li w Fei-xMn x PO4 (in which w < 1, 1, preferably w is 1; 0 < x < 1, preferably 0.2 < x < 0.4), • Li w Mn2O4 (in which ws 1 ,1, preferably w is 1), • LiwMn15Nio5O4 (where ws 1,1, preferably w is 1), • Li4+ z Tis012 (where 0 < z < 3), or • NMC (Li w Nii- x -yMnxCoyO2, in which w < 1,3, preferably w is 1; 0 S x ^ 1, 0 S y < 1, and 0 S z < 1, and M is Al, Mg, Ti, Nb, Zr, W, Mo, Y, La, Ta or one of their mixtures). Note that the Li intercalation material may contain an excess of lithium, meaning that its Li content is greater than the stoichiometric ratio.

[0019] In preferred embodiments, the intercalation material of relithié Li is Li w FePO4.

[0020] In preferred embodiments, the relithied Li intercalation material is produced from partially or fully relithied Li intercalation material produced by the method of the invention. In other embodiments, the relithied Li intercalation material is derived from used electrodes, for example via battery recycling, and then relithied. Production anode

[0021] The invention also relates to a production anode for producing metallic lithium or an alloy thereof, or for pre-lithiating an electrode material, the anode comprising a relithiated lithium intercalation material. This anode is called a "production anode" to distinguish it from another anode described below used for an electrolytic relithiation reaction, which will be called a "relithiation anode." In a related aspect, the invention relates to the use of a relithiated lithium intercalation material as an anode for producing metallic lithium or an alloy thereof, or for pre-lithiating an electrode material.

[0022] In some embodiments, the anode is intended to produce metallic lithium or a lithium alloy. In some embodiments, metallic lithium is produced. In other embodiments, the lithium alloy is produced. Preferably, the metallic lithium or its alloy is in the form of a film. Preferably, the metallic lithium or its alloy is produced by electrodeposition.

[0023] In some embodiments, the anode is intended for the pre-lithiation of an electrode material. The electrode material is as defined above.

[0024] The relithié Li intercalation material is as defined above.

[0025] In some embodiments, the production anode is intended for an electrolytic reaction for the production of Li.

[0026] In some embodiments, the production anode further comprises a current collector, and the relithiated Li intercalation material is deposited onto the current collector. This current collector may be made of any electronically conductive material, including any material used for battery current collectors. In some embodiments, this current collector is a metal foil, preferably made of Cu, Al, stainless steel, Ti, or Ni, or is made of a conductive carbon material, or is a polymer-based current collector. In the most preferred embodiments, this current collector is coated with a primer layer to improve the adhesion of the intercalation material. Li, such as a carbon-containing paint. In preferred embodiments, this current collector is a metal sheet made of stainless steel or Al, preferably a current collector comprising a carbon-coated AI sheet.

[0027] In preferred embodiments, the production anode is in the form of a film. Production electrolysis cell

[0028] The invention also relates to a production electrolysis cell for producing metallic Li or an alloy thereof or for pre-lithiating an electrode material, the production electrolysis cell comprising: a relithiated Li intercalation material used as a production anode, a current collector used as a production cathode, and a production electrolyte between the production cathode and the production anode, the production electrolyte comprising a production lithium salt dissolved in a production solvent.

[0029] Here, these cell, cathode, electrolyte, salt, and solvent are called "production cell," "production cathode," and so on, to distinguish them from the cell, cathode, electrolyte, salt, and solvent described below, which are used for an electrolytic relithiation reaction, and are called "relithiation cell," "relithiation cathode," and so on.

[0030] In a related aspect, the invention relates to the use of this production electrolysis cell to produce metallic Li or an alloy thereof or to pre-lithiate an electrode material.

[0031] The relithié Li intercalation material is as defined above.

[0032] The production anode is as defined above.

[0033] The lithium salt used in production can be any salt compatible with metallic Li (or the alloy produced). In some embodiments, the lithium salt of production is lithium (fluorosulfonyl)(trifluoromethanesulfonyl)imide, lithium 2-trifluoromethyl-4,5-dicyanoimidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium bis(pentafluoroethylsulfonyl)imide (LiBETI), lithium difluorophosphate (LiDFP), lithium chloride (LiCl), lithium bromide (LiBr), lithium hexafluoroarsenate (LiAsFe), a lithium fluoroalkylphosphate [such as LiPFstCF^FsJs], lithium tetrakis(trifluoroacetoxy)borate (LiB(OCOCF3)4), lithium bis(1,2-benzenediolato(2-)-O,O')borate LiB(CeO2)2, difluoro(oxalato)borate lithium (LiBF2(C2C>4)), a compound with the formula BF2C>4Rx' (R x(= C2-4 alkyl), UCF3COO, LiF, UNO3, LiPFe, UBF4, LiBOB, UCIO4, LiTFSi, CF3SO3U, LiFSi, or any combination thereof, preferably UCF3COO, LiF, UNO3, LiPFe, LiBF4, LiBOB, UCIO4, LiTFSi, CF3SO3U, LiFSi, or any combination thereof. In preferred embodiments, the lithium salt produced is a combination of CF3SO3U and LiFSi.

[0034] In some embodiments, the production electrolyte further comprises one or more additives. Non-limiting examples of additives include those that modify the morphology and / or properties metallic Li or its alloy, additives that influence the phase nucleation energy, additives that influence the deposition potential of metallic Li or its alloy, and additives that influence the electrodeposition efficiency of metallic Li or its alloy. In some embodiments, the additive(s) are: • an unsaturated cyclic carbonate such as vinylene carbonate (VC), • a halogenated cyclic carbonate such as fluoroethylene carbonate (FEC), • a nitrate, • a Li polymerization agent comprising a saturated or unsaturated hydrocarbon chain, such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), • a Li passivation compound, and / or • an alkali salt of an organic acid, such as lithium difluoro(oxalate)borate (LiDFOB) or Li oxalate.

[0035] The production solvent can be any solvent commonly used in Li-ion batteries. In some embodiments, the production solvent is an organic carbonate, an organic ester, an organic ether, an ionic liquid, or any combination thereof. In preferred embodiments, the production solvent is ethylene carbonate (EC), propylene carbonate (PC), fluoroethylene carbonate (FEC), gamma-butyrolactone (gBL), ethyl propionate, diethyl carbonate (DEC), dimethyl carbonate (DMC), ethylmethyl carbonate (EMC), dimethoxyethane (DME), fluoroether, tetrafluoroethyltetrafluoropropylether (TTE), tetraethylene glycol dimethyl ether (TEGDME), or any combination thereof.

[0036] In some embodiments, the production electrolysis cell lacks a membrane separating the production anode from the production cathode.

[0037] In some embodiments, the production electrolysis cell adopts a roll-to-roll configuration. Indeed, the membrane-free configuration of the cell allows the use of a multilevel roll-to-roll configuration such as that shown, for example, in Figure 3. In such embodiments, the cell may further include one or more calendering devices, such as pairs of calendering rollers, for example at fixed intervals, to densify the Li (or Li alloy) film electrodeposited during its formation.

[0038] In some embodiments, the production electrolysis cell is used to pre-lithiate an electrode material. The electrode material is as defined above and is used as the production cathode. In operation, the production electrolysis cell introduces lithium into the electrode material.

[0039] In other embodiments, the production electrolysis cell is intended to produce metallic lithium or its alloy. The current collector is used as the production cathode. In some embodiments, metallic lithium is produced. In other embodiments, a lithium alloy is produced. is produced. Preferably, the metallic Li or its alloy is in the form of a film. Preferably, the metallic Li or its alloy is produced by electrodeposition. In operation, the production electrolysis cell allows the electrodeposition of a film of metallic Li or its alloy onto the current collector used as the production cathode.

[0040] In preferred embodiments, operating conditions, such as stirring and / or temperature control, are used to modify the morphology of the produced Li metal / alloy.

[0041] In preferred embodiments, the current collector used as the production cathode is in the form of a sheet.

[0042] The current collector used as the production cathode can be made of any electronically conductive material, including any material used for current collectors in batteries. In some embodiments, the current collector is made of Cu, Al, protected aluminum, C, stainless steel, Ti, Zn, or Ni or one of their alloys, or is a current collector based on a metallized polymer, or a combination thereof.

[0043] In preferred embodiments, the current collector is made of protected Cu or AI.

[0044] The current collector used as a production cathode may or may not be protected by a protective layer. The surface of the current collector can be treated or modified to improve its lithophilicity. The surface of the current collector can be treated or modified to have a 3D structure to improve the electrochemical performance of the metallic (or alloy) Li layer in batteries or to increase its reaction rate, for example, when used in the fabrication of an organolithium compound.

[0045] In some embodiments, the production electrolyte further comprises one or more alloying salts. An alloying salt is a salt of one or more metals capable of forming an alloy with lithium. When an alloying salt is used, a lithium alloy will be produced at the cathode. In alternative embodiments, the production electrolyte is free of alloying salts, and consequently, metallic lithium (rather than a lithium alloy) will be produced at the cathode.

[0046] In preferred embodiments, the alloy mainly comprises lithium. In preferred embodiments, the alloy comprises about 80% w / w or more of Li, preferably about 85% w / w or more of Li, more preferably about 90% w / w or more of Li, even more preferably about 95% w / w or more of Li, based on the total weight of the alloy.

[0047] In some embodiments, the alloy salt is a salt of one or more of the following elements: Na, K, Mg, Ca, a transition metal, Al, Ga or Sn; preferably Al or Mg.

[0048] In some embodiments, the alloying salt is a (fluorosulfonyl)(trifluoromethanesulfonyl)imide salt, a 2-trifluoromethyl-4,5-dicyanoimidazolate (TDI) salt, a 4,5-dicyano-1,2,3-triazolate (DCTA) salt, a bis(pentafluoroethylsulfonyl)imide (BETI) salt, a difluorophosphate (DFP) salt, a chloride salt, a bromide salt, a fluoride salt, a hexafluoroarsenate (AsFe) salt, a fluoroalkylphosphate salt, a tetrakis(trifluoroacetoxy)borate salt, a bis(1,2-benzenediolato(2-)-O,O')borate salt, a difluoro(oxalato)borate salt, a nitrate salt, a salt trifluoroacetate, a hexafluorophosphate salt, a tetrafluoroborate salt, a bis(oxalate)borate (BOB) salt, a perchlorate salt, a bis(trifluoromethanesulfonyl)imide (TFSI), a bis(fluorosulfonyl)imide (FSI) salt, a triflate salt, or a salt with an anion of formula: BF2O4R (x = alkyl in C2-4). Process for producing metallic lithium / alloying it or for pre-lithiating an electrode material

[0049] The invention also relates to a method for producing metallic Li or an alloy thereof or for pre-lithiating an electrode material, the method comprising: a) supplying a relithiated Li intercalation material, and b) carrying out an electrolytic reaction for the production of Li in a production electrolysis cell, the production electrolysis cell comprising: said relithiated Li intercalation material as a production anode, a current collector or said electrode material as a production cathode, and a production electrolyte between the production cathode and the production anode, the production electrolyte comprising a production lithium salt dissolved in a production solvent,thus enabling the electrodeposition of metallic Li or an alloy thereof onto the current collector used as a production cathode, or the introduction of lithium into the electrode material used as a production cathode, thereby producing a pre-lithianed electrode and thus enabling the production of a partially or completely delithiated Li intercalation material.

[0050] In some embodiments, the process is used to produce metallic lithium or its alloy. In certain embodiments, metallic lithium is produced. In other embodiments, the lithium alloy is produced. In all these embodiments, the current collector is used as the production cathode. Preferably, the metallic lithium or its alloy is in the form of a film.

[0051] In other embodiments, the process is used to pre-lithiate an electrode material. The electrode material is as defined above and is used as the production cathode.

[0052] This process, as well as the material, anode and cell (and uses) described in the previous sections, have several advantages. • It eliminates the need for any membrane in the production electrolysis cell, reducing costs, preventing contamination issues (particularly water leaks) that could affect lithium purity, and eliminating downtime for membrane maintenance. This allows for a multi-level roll-to-roll configuration, with optional calendering within the production electrolysis cell, resulting in a significant reduction in process space and a substantial increase in production speed. • It can use a used positive electrode material previously used in a secondary battery (to make it a relithied Li intercalation material) and allows the recycling of used secondary batteries. • The process can be in a closed loop, which limits the environmental impact and ensures safety. • The process makes it possible to generate an ultra-thin and homogeneous metallic lithium electrode with high purity, without requiring an additional purification step, at low cost. • The process makes it possible to produce a film or sheet of Li without melting the lithium. • The process does not require high-temperature electrolysis. • The lithium produced can be used in the manufacture of primary and secondary lithium-based batteries as well as in the manufacture of organolithium compounds and in the pre-lithiation of an electrode material. • Regarding relithiation, the anodic reaction is a release of oxygen and not a release of chlorine (non-corrosive and easy to handle). • The lithium salt used can be an inexpensive and easy-to-purify lithium salt such as lithium carbonate or even low-purity lithium carbonate or any other lithium salt.

[0053] In preferred embodiments, the relithied Li intercalation material of the present process is as defined in the preceding sections.

[0054] In preferred embodiments, the production anode of the present process is as defined in the preceding sections.

[0055] In preferred embodiments, the production electrolysis cell of the present process is as defined in the preceding sections.

[0056] Preferably, the current collector with the metallic Li or its alloy or the pre-lithianed electrode is washed, for example with an organic solvent, and dried before use. Therefore, in one embodiment, the process further includes washing and drying the current collector with the metallic Li or its alloy or the pre-lithianed electrode produced in step b). Step b)

[0057] In step b), the relithied Li intercalation material acts as an anode to supply Li ions + for the electrodeposition of metallic Li or an alloy thereof or for the pre-lithiation of the cathode material.

[0058] Metallic lithium or a lithium alloy is deposited on a current collector that acts as the cathode. Metallic lithium or a lithium alloy is usually deposited electrolytically on the current collector as a thin film, generally of high purity. Alternatively, lithium is introduced into the electrode material that acts as the cathode.

[0059] The electrochemical reactions at the cathode and anode in the electrolytic production cell are as follows: Cathodic reaction: Li + + e- — > Li Anodic reaction (when LiFePCU is used as an intercalation material for relithied Li): LiFePCU → FePCU + e⁻ + Li +

[0060] The partially or completely delithiated Li intercalation material is produced at the anode (FePCU in the example above) and it can be used as a starting material in step a) to provide a relithied Li intercalation material, and thus possibly reused in step b).

[0061] In some embodiments, the electrolytic reaction for the production of Li is carried out by regulating the cell potential either between the production anode and the production cathode, or between the production cathode and a reference electrode.

[0062] In some embodiments, the electrolytic reaction for Li production is carried out by regulating the cell current. In these embodiments, the current-regulated electrolytic reaction for Li production can be carried out in direct or pulsed mode, either unidirectional or reverse. Similarly, the current-regulated electrolytic reaction for Li production can be carried out at a fixed frequency or at a variable frequency.

[0063] In some embodiments, step b) is carried out in a roll-to-roll configuration. Indeed, the membrane-free configuration of the electrochemical production cell used in step b) allows for the use of a multilevel roll-to-roll configuration such as that shown, for example, in Figure 3. In such embodiments, the cell may further include one or more calendering devices, such as calendering rollers, for example at fixed intervals, to densify the electrodeposited Li film during its formation. Step a)

[0064] As stated above, a relithied Li intercalation material is a partially or fully relithied Li intercalation material that has been relithied.

[0065] The intercalation material for partially or completely delithiated Li is not particularly limited. It should be chosen so that it is stable under the conditions used for relithiation (electrolyte, etc.). In some embodiments, the intercalation material for partially or completely delithiated Li is a partially or completely delithiated lithium phosphate or lithium oxide, preferably Li w FePC>4, Li w Mn2C>4, Li4+zTisOi2, or NMC (Li w Nii-x-yMnxCoyM z O2) partially or completely delithiated. In preferred embodiments, the partially or completely delithiated Li intercalation material is partially or completely delithiated LiwFePCU (preferably w being 1).

[0066] In some embodiments, step a) is carried out in a roll-to-roll configuration.

[0067] In some embodiments, step a) may include: a') the supply of a partially or completely delithiated Li intercalation material and a") the relithiation of the partially or completely delithiated Li intercalation material, thereby producing a relithiated Li intercalation material. Next, the relithié Li intercalation material is used in step b).

[0068] In preferred embodiments, the relithié Li intercalation material is washed, preferably washed and dried, before being used in step b).

[0069] In some embodiments, the partially or completely delithiated Li intercalation material is obtained from recycled used batteries.

[0070] As stated above, in some embodiments (preferably where the process of the invention is repeated or continuous), the partially or completely delithied Li intercalation material of step a') can be that produced in step b). Therefore, in some embodiments, the process further comprises step c) repeating steps a) and b) one or more times, and using in steps a') and a"), the partially or completely delithied Li intercalation material produced in step b).

[0071] The partially or completely delithied Li intercalation material can be relithied in step a”) by any process known in the art. Relithiation by electrolysis using an electrolyte with a lithium salt

[0072] In preferred embodiments, step a”) includes carrying out an electrolytic relithiation reaction in a relithiation electrolysis cell, the relithiation electrolysis cell comprising: the partially or completely delithiated intercalation material as a relithiation cathode, a relithiation anode, and a relithiation electrolyte between the relithiation cathode and the relithiation anode, the relithiation electrolyte comprising a relithiation lithium salt dissolved in a relithiation solvent, thus enabling the partially or completely delithiated intercalation material to be relithied and the relithiated Li intercalation material to be produced.

[0073] In this electrolytic reaction, the lithium salt from relithiation is used as a source of Li ions. +and the partially or completely delithiated intercalation material is used as the cathode. The general reactions are as follows: Anodic reaction (when FePO4 is used as an intercalation material for delithiated Li): 2 Li + + 2nd _ + 2 FePO4— > 2 LiFePO4 Anodic reaction (when UHCO3 is used as a lithium salt for relithiation): 2 HCO3- 2 e 1 / 2O2 + H2O + 2 CO2

[0074] The relithiation solvent can be any solvent capable of solubilizing a lithium salt and supporting a compatible anodic reaction, or a mixture thereof. In preferred embodiments, the relithiation solvent is water, which is an advantage of the invention.

[0075] The anode material is not particularly limited. In some embodiments, the relithiation anode is made of a material compatible with the anodic reaction, preferably compatible with the oxygen evolution reaction. In preferred embodiments, the relithiation anode is made of lead, platinum, titanium, another inert metal, or an alloy thereof, or graphite, etc. In preferred embodiments, the relithiation anode is dimensionally stable.

[0076] In some embodiments, the relithiation electrolyte further comprises one or more additives. Such additives generally do not participate in the relithiation electrolysis reaction. Non-limiting examples of additives include those that improve the electrical conductivity properties of the relithiation electrolyte. In some embodiments, the additive(s) are a salt comprising an alkali metal cation other than lithium or an alkaline earth metal cation (preferably potassium or magnesium) and an anion compatible with the relithiation electrolysis reaction (preferably sulfate or bicarbonate).

[0077] The relithiation salt can be any lithium salt soluble in the relithiation electrolyte, for example LiFSI or LiTFSI.

[0078] In the most preferred embodiments, the relithiation salt is an inexpensive lithium salt. Examples of low-cost lithium salts include: • lithium salts extracted from mines, such as Li2CC>3, • Lithium salts economically prepared from salts extracted from mines, such as: o Li HCO3, which can be prepared from Li2CC>3 as shown in Example 1; o Li2SC>4, which can be prepared from Li2COs as shown in Example 2; o LiOH, which can be prepared by electrolysis of LiCl, Li2SC>4 or UHCO3 or from Li2CO3 by a metathesis reaction with calcium hydroxide; o Li NO3, which can be prepared by treating Li2COs or LiOH with nitric acid; o UCH3COO, which can be prepared by treating Li2CO3 with acetic acid; and o Li2C2O4, which can be prepared by treating Li2COs with oxalic acid. • lithium salts produced during the hydrometallurgical recycling of used lithium batteries, which include, for example, many of the salts already listed above; and • lithium salts recovered from lithium-containing solutions, for example geothermal brines, salt flat brines, solutions from lithium ore processing and lithium battery recycling processes, which again include, for example, many of the salts already listed above.

[0079] In preferred embodiments, the relithiation salt is easy to purify. One example is the IJ2CO3 which is easy to purify due to its low solubility (it will precipitate out of the solution while the impurities will remain solubilized) and easy to dry due to its low hygroscopicity (unlike LiCl which is more difficult to purify due to its very high solubility in water and very difficult to dry due to its high hygroscopicity).

[0080] In preferred embodiments, the relithiation salt is IJCO3, Li HCO3, LiOH, Li NO3, LiOH, IJ2SO4, UCH3COO, LiFSI, LiTFSI or IJ2C2O4, or a mixture of these, preferably the relithiation salt is LiHCOs, U2SO4, or a mixture of these, preferably the relithiation salt is U2SO4.

[0081] In embodiments where the relithiation solvent is water, the relithiation salt may advantageously be a water-soluble relithiation salt. In most preferred embodiments, the relithiation salt is a water-soluble relithiation salt that has a water solubility greater than that of UHCO3. Non-limiting examples of such salts include: UNO3, U2SO4, and UHC3COO. The conversion of Li2COs to these salts may offer certain advantages over using Li2COs as UHCO3.For example, the relithiation electrolytic cell can operate at higher temperatures (since the solubility of these salts increases with higher temperatures, unlike that of Li HCO3), which, with their higher solubility, can help to make the electrolytic cell operate at higher current densities (higher cell productivity and lower investment cost).

[0082] In some embodiments, the relithiation salt is produced in situ, i.e., within the relithiation electrolysis cell. In such embodiments, the process includes adding a lithium precursor and a reagent to the relithiation electrolysis cell, enabling them to react to form the relithiation salt. In preferred embodiments, the lithium precursor and the reagent can be added to a salt-forming compartment of the relithiation electrolysis cell that is in fluidic communication with a main compartment of the relithiation electrolysis cell; the main compartment comprising the relithiation cathode and the relithiation anode.

[0083] In alternative embodiments, the relithiation salt is simply added to the relithiation electrolysis cell. This means that the relithiation salt is prepared before being added to the relithiation electrolysis cell. In such embodiments, the process may include a step of reacting the lithium precursor and the reagent in a separate reactor to obtain the relithiation salt, followed by adding the relithiation salt to the relithiation electrolysis cell.

[0084] In all cases, the choice of lithium precursor and reagent will, of course, depend on the desired relithiation salt. For example, Li₂HCO₃, U₂SO₄, LiNOs, and UCH₃COO can be prepared by reacting Li₂CO₃ with CO₂, H₂SO₄, nitric acid, or acetic acid, respectively. In such embodiments, the lithium precursor is therefore U₂CO₃, LiOH, or a mixture thereof, as desired. Similarly, in such embodiments, the reagent is therefore CO₂, H₂SO₄, nitric acid, acetic acid, oxalic acid, or an acidic form of a sulfonylurea salt, or a mixture thereof, as desired. In preferred embodiments, the lithium precursor is U₂CO₃. In other embodiments, In preferred embodiments, the reactant is CO2, H2SO4, or a mixture thereof. In more preferred embodiments, the reactant is CO2. In alternative more preferred embodiments, the reactant is H2SO4.

[0085] It is interesting to note that, when LiHCO3 is used as a relithiation salt, the anodic reaction in the relithiation cell produces CO2, which can be reused to produce more UHCO3 from Li2CO3.

[0086] It is also worth noting that, when Li2CO3 is used as a lithium precursor for a Li electrolyte comprising salts such as Li NO3, U2SO4 or LiCH3COO as a relithiation salt, it is not necessary to add an acid to compensate for the H+ ions consumed during the conversion of the carbonate salt because H+ ions are regenerated at the anode.

[0087] In some embodiments, the electrolytic relithiation reaction is carried out by regulating the cell potential either between the relithiation anode and the relithiation cathode, or between the relithiation cathode and a reference electrode.

[0088] In some embodiments, the electrolytic relithiation reaction is carried out by regulating the cell current. In these embodiments, the electrolytic reaction in regulated current mode can be carried out in direct or pulsed mode, either unidirectional or reverse. Similarly, the electrolytic reaction in regulated current mode can be carried out at a fixed frequency or at a variable frequency. Relithiation using a reducing agent

[0089] In variant embodiments, step a”) includes carrying out a relithiation reaction as described in WO 2021 / 092692, incorporated herein by reference.

[0090] In preferred embodiments, the process comprises (i) adding the partially or completely delithiated intercalation material to a solution containing a reducing agent and a relithiating salt in a solvent; thereby relithifying the partially or completely delithiated intercalation material and producing the relithied Li intercalation material. The reaction is as follows: 2 Li + + 2 R-Fe 2+ + 2 FePO42 LiFePO4+ 2 R'-Fe 3+ (in which R and R' are anionic molecules or complexing agents).

[0091] In some embodiments, the process further comprises (ii) separating the relithied Li intercalation material from the solution; and preferably (iii) electrochemically treating the solution separated in step (ii) to regenerate the reducing agent.

[0092] The relithiation salt is as described in the previous section.

[0093] In some embodiments, the reducing agent is the reducing element of a redox couple having a redox potential lower than that of the partially or completely delithiated intercalation material.

[0094] According to one embodiment, the redox couple includes, for example, a Fe(l I l) / Fe(l I) complex, for example chosen from [Fe(CN)6] 3 7Fe(CN)6] 4 -, [Fe(nta)] / [Fe(nta)]-, [Fe(tdpa)] 2 7Fe(tdpa)] 3 -, [Fe(edta)]7[Fe(edta)] 2 -, [Fe(citrate)] / [Fe(citrate)]-, [Fe(l I l)-TEA] / [Fe(ll)-TEA] and [Fe(oxalate)]7[Fe(oxalate)].

[0095] According to one embodiment, step (i) further includes a step of deoxygenating the solution.

[0096] According to one embodiment, steps (i) and / or (iii) are carried out in the absence of oxygen.

[0097] In one embodiment, the process further includes a step of adjusting the pH of the solution to a pH suitable for the electrochemically active material of step (i) (for example, for FePCU, the pH is adjusted between 5 and 9, preferably between 6 and 7.5).

[0098] In another embodiment, the solvent is an aqueous solvent.

[0099] According to one embodiment, step (iii) of the electrochemical treatment is carried out in an electrolytic cell by passing a current between at least one cathode and at least one anode. The reactions involved in step (iii) are as follows: Cathodic reaction: 2 R-Fe 3+ + 2 e - — > 2 R'-Fe 2+ Anodic reaction: 2 OH' - 2 e- — > 1 / 2Û2 + H2O

[0100] In one embodiment, the electrolytic cell includes at least one ionic or non-ionic separator installed between the anode and the cathode to protect the regenerated reducing agent. In another embodiment, the electrolytic cell further includes a system for maintaining the deoxygenated solution, for example, a system comprising maintaining an oxygen-free gas in the electrolytic cell, such as carbon dioxide, nitrogen, or argon.

[0101] In some embodiments, step (iii) is carried out by regulating the cell potential either between the anode and the cathode, or between the cathode and a reference electrode.

[0102] In some embodiments, step (iii) is carried out by regulating the cell current. In some embodiments, the current-regulated relithiation reaction can be carried out in direct mode, in pulsed mode, either simple (unidirectional) or reverse. Similarly, the current-regulated relithiation reaction can be carried out at a fixed frequency or at a variable frequency. Uses of the current collector with metallic Li or its alloy and / or the pre-lithianed electrode produced in step b)

[0103] The current collector with metallic Li or its alloy and the prelithiated electrode produced in step b) can be used for many different purposes.

[0104] In some embodiments, the current collector with metallic Li or its alloy and the prelithiated electrode is used: • as the negative electrode in a primary or secondary Li battery, preferably a lithium-ion or all-solid-state battery, • as a source of metallic Li or its alloy for pre-lithiating an electrode material, and • as a source of metallic Li or its alloy for manufacturing a system of energy storage.

[0105] In some embodiments, the current collector with metallic Li or an alloy thereof is used as a source of metallic Li or an alloy thereof for the preparation of an organolithium compound.

[0106] In some embodiments, the current collector made of metallic lithium or its alloy is rolled to modify its morphology, density, or thickness. Rolling can be performed by cold rolling at room temperature or at a higher temperature. If the rolling temperature is above the melting point of lithium, a substrate exhibiting high lithophilicity can be advantageously used. Non-limiting examples of such substrates include silicon, tin, zinc, aluminum, zinc oxide, copper oxide, copper oxide, and carbon oxide.

[0107] In some embodiments, the current collector with metallic Li or its alloy is treated to have a 3D structure. Such a structure can be used to improve the electrochemical performance of the Li layer in batteries or to increase its reaction rate when used for the preparation of organolithium compounds.

[0108] In some embodiments, the current collector with metallic lithium or its alloy is surface-treated to improve its electrochemical performance in batteries. For example, a thin layer of an element, such as zinc or aluminum, or one of their alloys, can be deposited onto the lithium layer. Various deposition processes, such as physical vapor deposition (PVD) or spray coating, can be used.

[0109] In other embodiments, the current collector with metallic lithium or an alloy thereof is used to produce an organolithium compound. In such preferred embodiments, it is reacted with a reagent, such as an alkyl halide, to produce the organolithium compound. Such compounds are important reagents used as polymerization initiators in the production of elastomers or as strong basic reagents in the synthesis of organic and pharmaceutical molecules. As an example, 1-chlorobutane dissolved in an organic solvent (such as cyclohexane) can be reacted with electrolytically deposited metallic lithium or an alloy thereof to produce n-butyllithium.In more specific embodiments, the process further includes the step of transferring the current collector with the metallic Li or its alloy produced in step b) to a separate reactor, preferably in roll-to-roll mode, reacting the electrolytically deposited metallic Li or an alloy thereof with a reagent in said separate reactor to produce an organolithium compound. Lithium electrode produced by the above method

[0110] The invention also relates to a lithium electrode comprising the current collector with the Li metal or its alloy as described above (i.e. as produced by the above process).

[0111] The invention also relates to a lithium battery comprising this lithium electrode. In preferred embodiments, the lithium battery is a lithium-ion battery or a completely solid-state battery. Definitions

[0112] The use of the terms "a" and "an" and " / e" and similar referents in the context of the description of the invention (particularly in the context of the following claims) shall be interpreted as covering both the singular and the plural, unless otherwise stated herein or clearly contradicted by context.

[0113] The terms "comprising," "having," "comprising," and "containing" should be interpreted as open-ended terms (i.e., meaning "including, but not limited to") unless otherwise specified. Conversely, the expression "consisting of" excludes any unspecified element, step, ingredient, or similar. The expression "essentially consisting of" limits the scope to the specified materials or steps and to those that do not materially affect the fundamental and novel feature(s) of the invention.

[0114] The statement of value ranges here is simply intended as a shorthand method for individually referencing each distinct value falling within the range, unless otherwise stated here, and each distinct value is incorporated into the specification as if it were stated individually here. All subsets of values ​​within the ranges are also incorporated into the specification as if they were stated individually here.

[0115] All the procedures described herein can be performed in any appropriate order, unless otherwise stated herein or clearly contradicted by the context.

[0116] The use of any or all of the examples, or examples of exemplary languages ​​(e.g., "such as") provided herein, is intended merely to further illuminate the invention and does not impose any limitation on the scope of the invention unless otherwise stated.

[0117] No language in the specification shall be interpreted as indicating an unclaimed element as essential to the implementation of the invention.

[0118] Here, the term "approximately" has its ordinary meaning. In embodiments, it can mean plus or minus 10% or plus or minus 5% of the qualified numerical value.

[0119] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as that commonly understood by a person skilled in the art to whom this invention belongs.

[0120] Other objects, advantages and features of the present invention will become more evident upon reading the following non-restrictive description of specific embodiments thereof, given by way of example only with reference to the accompanying drawings. DESCRIPTION OF ILLUSTRATIVE METHODS OF IMPLEMENTATION

[0121] The present invention is illustrated in more detail by the following non-limiting examples. Example 1 - Apparatus for implementing the process of the invention using LiHCOs produced in situ as a relithiation salt

[0122] A diagram of one embodiment of the process of the invention is shown in Figure 1.

[0123] A relithiation electrolysis reaction is carried out in a relithiation electrolysis cell (10) comprising a relithiation electrolyte and equipped with a stirrer (12). In Figure 1, the relithiation electrolyte comprises LiHCO₃⁻ as the relithiation salt.

[0124] This LiHCO3-relithiation salt is produced in a relithiation electrolysis cell (10) by reacting a lithium precursor, namely U2CO3 powder (14), with a reagent, in this case CO2, which is added to the electrolyte using a bubbler (16). A wall (18) divides the relithiation electrolysis cell (10) into a salt-forming compartment (20) and a main compartment (22) connected by fluidic means.

[0125] The main compartment (22) of the relithiation electrolysis cell (10) comprises a relithiation anode (24) and a partially or fully delithiated intercalation material (26) serving as the relithiation cathode. After the relithiation electrolysis reaction, the partially or fully delithiated intercalation material (26) is relithied to form a relithiated Li intercalation material (28). In this example, LiFePCU (LFP) on a metal foil is used as the intercalation material, which is partially or fully delithiated and relithied.

[0126] This step is carried out in a roll-to-roll configuration. The partially or completely delithiated intercalation material (26) supplied by the roller (30) is thus introduced into the relithiation electrolysis cell (10), and the relithiated Li intercalation material (28) is extracted from the relithiation electrolysis cell (10) and collected on a roller (32) using intermediate rollers (34, 36, 38, and 40). A series of washing, rinsing, spinning, and drying steps can be included in the roll-to-roll unit.

[0127] The roll (32) of relithied Li intercalation material (28) is transferred to a production electrolysis cell (42) as indicated by arrow B. The production electrolysis cell (42) uses the relithied intercalation material (28) as the production anode, a current collector (44) as the production cathode, and a production electrolyte. In this example, the current collector (44) is a treated or untreated Cu foil.

[0128] In the production electrolysis cell (42), lithium is electrodeposited onto the current collector (44), producing a current collector coated with Li (46), and the relithiated Li intercalation material (28) is delithiated (partially or completely), thus regenerating the Li intercalation material (28). The Li intercalation material (28) can then be returned to the relithiation electrolysis cell (10) for further relithiation as indicated by arrow A.

[0129] This step is also carried out in a roll-to-roll configuration. The relithiated Li intercalation material (28) is fed by a roller (32), and the partially or completely relithiated intercalation material (26) is collected on a roller (30) using intermediate rollers (48, 50, 52, and 54). Similarly, the collector The current (44) is supplied by a roller (56) and the Li-coated current collector (46) is collected on a roller (58) by means of intermediate rollers (60, 62 and 64). A series of washing, rinsing, spinning and drying stages can be included in the roll-to-roll unit.

[0130] The Li-coated current collector (46) can be used or modified in various ways. Arrow C shows that the roller (58) of the Li-coated current collector (46) can be cold-rolled using cold-rolling rollers (60) to form a cold-rolled Li-coated current collector (62), which is collected onto the roller (64) via intermediate rollers (66, 68). Arrow D shows that the roller (58) of the Li-coated current collector (46) can be hot-rolled using hot-rolling rollers (70) to form a hot-rolled Li-coated current collector (72), which is collected onto the roller (74) via intermediate rollers (76, 78).

[0131] In Figure 1, the intercalation material used in the Li production step is LiFePCU (LFP) on an aluminum substrate. The delithiated intercalation material produced (FP in this figure) is returned to the relithiation step to be relithied in an aqueous cathodic reaction with oxygen evolution as the anodic reaction, as follows: Reaction 1 (cathodic reaction): 2 Li + + 2 e- + 2 FePCU — 2 LiFePCU Reaction 2 (anodic reaction): 2 HCO3- → V2O2 + H2O + 2 CO2 + e-

[0132] The source of Li ions in this case is U2CO3 dissolved in water as UHCO3 by bubbling CO2 through the U2CO3 suspension in water according to the following reaction: Reaction 3: U2CO3 + CO2 + H2O → 2 UHCO3

[0133] The advantage of dissolving Li2COs as UHCO3 is the higher solubility of UHCO3 compared to that of Li2COs. Example 2 - Apparatus for implementing the process of the invention using I2SO4 produced in situ as a relithiation salt

[0134] Figure 2 shows another embodiment of the process of the invention, which is based on the conversion of Li₂CO₃ to U₂SO₄. Thus, Figure 2 is quite similar to Figure 1, except that the bubbler is absent and the relithiation electrolyte in the relithiation electrolysis cell (10) is different. The source of Li ions in this case is Li₂CO₃ dissolved in water as U₂SO₄ by reacting it with the acid H₂SO₄ according to the reaction: Reaction 6: U2CO3 + H2SO4 → U2SO4 + CO2 + H2O

[0135] The cathodic reaction is the same as in the case of a UHCO3-based electrolyte (Example 1). However, in the anodic reaction, in addition to the release of oxygen, H+ ions are also released. + are generated which contribute to the regeneration of H2SO4 necessary for the conversion of U2CO3 to Li2SC>4. Reaction 7 (cathodic reaction): 2 Li + + 2 e- + 2 FePC>4 — 2 LiFePCU Reaction 8 (anodic reaction): H2O - 2 e- — > 1 / 2Û2 + 2 H +

[0136] Therefore, when U2CO3 is added to a dedicated compartment of the electrolytic relithiation cell, it is not necessary to add an acid to the solution during the continuous addition of Li2Cu3 powder to the cell thanks to the continuous generation of H+ ions. + at the anode level. Example 3: Electrodeposition cell with roll-to-roll configuration

[0137] Figure 3 shows another embodiment of an apparatus for implementing the process of the invention. In this case, the electrodeposition of Li (step b) is carried out in a roll-to-roll configuration. The absence of a membrane in the production electrolysis cell (42), which is one of the advantages of the invention, allows the use of a multilevel electrolysis configuration, which is very difficult to achieve if the Li electrolysis cell has to have separate anolyte and catholyte compartments as described in US 2021 / 0381115 A1 and US 2022 / 0367874 A1.

[0138] In Figure 3, two rollers (32) feed the production electrolysis cell (42) with relithied Li intercalation material (28). Similarly, two rollers (30) collect the partially or fully relithied intercalation material (26). This is done via several intermediate rollers (76). In addition, the current collector (44) is fed by a roller (56), and the Li-coated current collector (46) is collected on a roller (58) via intermediate rollers (78) and pairs of calendering rollers (80).

[0139] Indeed, the cell is also equipped with several pairs of calendering rollers that densify the Li metal layer during electrodeposition while it is still immersed in the electrolyte. This also minimizes inclusions in the Li film and increases its purity. Example 4: Electrodeposition of Li as a thin film in a pocket cell

[0140] A thin film of lithium was electrolytically deposited onto an ultrathin current collector using lithium polymerase chain reaction (LFP) as the lithium ion source in a pocket cell assembly. We confirmed the production of a lithium layer approximately 11.5 µm thick.

[0141] A thin film of metallic lithium was obtained by electrodeposition in a lithium double salt electrolyte dissolved in a carbonate-based solvent. The electrolytic solution was prepared by mixing ethylene carbonate (EC) with diethylene carbonate (DEC) in a glove box filled with Ar in a 50 / 50 volume ratio. Lithium triflate (UCF3COO) and lithium bis(fluorosulfonylmide) (LiFSI) were then added to the solvent mixture at concentrations of 0.9 M and 0.1 M, respectively. The suspension was vigorously stirred until the salts were completely dissolved. To ensure the stability of the electrolyte with the metallic lithium and to eliminate any trace of water, a small strip of bare metallic lithium was immersed in the electrolyte for at least 24 hours prior to use.

[0142] The LiFePO4 (LFP) anode was prepared by mixing virgin carbon-coated LFP with Carbon conductive materials (carbon fiber (VGCF-H) and carbon black (Denka Black)) and a polymer binder (polyvinylidene fluoride (PVDF)) in a weight ratio of 91:2, 5:2, 5:4 were used. The mixture was dispersed in N-methyl-2-pyrrolidone (NMP) in a planetary centrifugal mixer until a perfectly uniform suspension was obtained. The suspension was coated onto a 15 µm thick carbon-coated aluminum foil using a squeegee and dried at 80 °C for 24 hours. The coating was densified by roller calendering. The total specific charge of the electrode is 10 mg / cm² 2 .

[0143] Li electrodeposition was performed in a pocket cell under galvanostatic conditions. The cell was assembled using a 4.5 µm thick dried copper foil as the cathode, the previously mentioned LFP applied to an AI foil as the anode, and a polypropylene (PP) membrane (Celgard 3501) as the separator. The two electrodes had an active specific surface area of ​​25.5 cm². 2 The pocket cell was filled with the previously prepared electrolyte, vacuum-sealed, and placed between pressure plates compressing the pocket cell to approximately 75 psi. Galvanostatic electrolysis was performed at 25 °C with a constant current of 0.5 mA / cm². 2 for a total charge passed of approximately 129 C. The applied current and potential response of this plating sequence are illustrated in Figure 4.

[0144] Once electrodeposition was complete, the lithium cathode was recovered by opening the pocket cell under a fume hood in a dry room. The Cu / Li electrode was washed three times with tetrahydrofuran (THF) and once with dimethoxyethane (DME). All solvents used were anhydrous. The lithium was then calendered between two stainless steel rollers at room temperature at a speed of 10 mm / s, while protecting the lithium's integrity by placing the electrode between an 11 µm copper foil underneath and a 20 µm polypropylene (PP) foil with another 11 µm copper foil on top. The calendered lithium was placed under vacuum for 12 hours to ensure that all the DME had evaporated. The resulting thin electrode sheet consists of a lithium layer approximately 11.5 µm thick on a 4.5 µm copper foil. Example 5: Relithiation of a delithiated LFP anode

[0145] In this example, a delithiated LFP (FP) electrode obtained from a button cell used to deposit Li under conditions similar to those in Example 4 was subsequently relithiated in an aqueous U2SO4 electrolyte. We confirmed that this resulted in complete relithiation of the electrode in aqueous medium.

[0146] The initial LFP electrode used during Li plating consists of a 16 mm diameter disc made of a mixture of LFP, conductive carbon, and PVDF applied to a 15 µm AI sheet as described in Example 4, with an active charge of 9.1 mg / cm² 2 Considering a theoretical capacity of 170 mAh / g LFP, the LFP anode has a charge capacity of 3.02 mAh. Lithium was then electrolytically deposited in a CR2032 coin cell by discharging the LFP anode against a 4.5 µm copper foil cathode at a constant current of 1 mA / cm². 2for 1.29 hours in the described double salt electrolyte In Example 4, Figure 5 shows the evolution of the potential over time recorded during this electrolysis. The total charge passing through the cell was 2.6 mAh. In this respect, based on a Coulomb calculation, the LFP electrode was 86% discharged.

[0147] In a second step, the delithiated LFP electrode (called the FP electrode) was recovered from the button cell and rinsed three times in THF, once in hexane, and then dried before relithiation. The FP electrode was assembled in a 1 cm² support. 2active surface area. A 0.25 M U₂SO₄ solution was prepared from ACS-grade lithium sulfate and demineralized water and adjusted to pH 6 with dilute H₂SO₄. Relithiation of the FP electrode was performed by placing the FP cathode and a dimensionally stable anode (DSA) in the lithium sulfate electrolyte. A constant potential of -0.05 V relative to NHE was applied between the cathode and an Ag / AgCl reference electrode (3.5 M KCl). After one hour, a total charge of 1.77 mAh had flowed through the FP electrode. Figure 6 shows the cumulative charge as a function of time. The degree of conversion (from FP to LFP) of the electrode before and after relithiation was confirmed by X-ray diffraction (XRD) analysis, as shown in Figure 7. The spectra of the electrode before relithiation show a partially relithiated electrode at 12.5%, which is in good agreement with the Coulombic data of Li electrodeposition.The spectra of the electrode after relithiation are similar to those of the virgin LFP, confirming the complete relithiation of the electrode. Example 6: Electrochemical properties of electrolytically deposited Li

[0148] The lithium-coated copper foil electrode produced in Example 4 was used as the negative electrode in a rechargeable lithium battery. We confirmed that button cells prepared with electrodeposited lithium exhibited significantly higher charge-discharge stability than cells prepared with a commercially available ultra-thin lithium foil produced by PVD.

[0149] First, a 14 mm diameter lithium anode disc was perforated between two sheets of PP from the calendered lithium obtained in Example 4.

[0150] A cathode was prepared by mixing Li(NiO₂,s,MnO₂,CoO₂,i)C>2 (NMC811), PVDF, DENKA black, and graphite in NMP in proportions of 94% w / w, 3% w / w, 2% w / w, and 1% w / w, respectively, using a Thinky™ centrifugal mixer. The resulting suspension was then applied to carbon-coated aluminum. The coating was dried at 130 °C and laminated to a density of 3.3 g / cm³. 3 The resulting cathode sheet was then dried again at 120 °C under vacuum for 12 hours.

[0151] A 14 mm diameter disc was perforated from the cathode foil and mounted in a stainless steel CR2032 button cell. The previously described calendered Li cathode and anode were separated by a Celgard 3501 membrane. The cell was filled with 60 pil of 1.7 M LiFSI salt dissolved in a DME-TTE mixture (molar ratio 1.2:3). Two cells were produced in this manner.

[0152] The cell was cycled at 25 °C at a charge / discharge rate of C / 10 for three cycles for training, and then at a rate of C / 3 for stability testing. Potential limits were set at 2.7 V and 4.2 V relative to Li + / Li°.

[0153] To compare the performance of electrolytically deposited lithium with that of commercially available ultrathin lithium sheets, reference cells were fabricated using a commercially available 5 µm lithium sheet as the anode, deposited directly onto a copper sheet by PVD. These cells were tested under the same conditions against the same NMC. The specific capacitance as a function of charge-discharge cycles is shown in Figure 8.

[0154] As can be seen, the two button cells prepared with electrolytically deposited Li exhibit significantly higher charge-discharge stability than the two cells prepared with commercially available ultra-thin Li sheets, prepared by PVD, described previously. Example 7: Electrodeposition of thin Li onto copper foil in a membrane-free electrochemical cell

[0155] A thin film of lithium was electrolytically deposited onto a copper foil (cathode) using an undivided beaker-type electrochemical cell (without any membrane separating the cathode and anodic compartments) (Ametek® SI Tait cell). The resulting lithium was then used as the negative electrode in a rechargeable lithium battery. We confirmed that the process of the invention can be implemented 1) in a membrane-free electrochemical cell and 2) at high current density (4 mA / cm²). 2 ).

[0156] More specifically, the cell consists of a lower plate on which a 4.5 µm thick flat copper foil cathode is placed, a glass tube (6.5 cm internal diameter) positioned on the copper foil, and an upper plate that securely holds the assembly together with long screws and nuts. A gasket ensures a seal between the copper foil and the glass body.

[0157] Electrodeposition was performed in a glove box filled with Ar (H₂O < 0.1 ppm; O₂ < 0.1 ppm) using an electrolytic solution composed of ethylene carbonate (EC) and diethylene carbonate (DEC) in a 50 / 50 volume ratio with lithium triflate (UCF₃COO) and lithium bis(fluorosulfonyl)imide (LiFSI) electrolytic salts at concentrations of 0.6 M and 0.4 M, respectively. The anode consisted of a 25 cm² stainless steel disc. 2covered with an LFP-based sludge of the same formulation as that described in example 4 with an active ingredient load of 23 mg / cm² 2 The anode was mounted on a stirring shaft and positioned 0.6 cm from the cathode leaf. A volume of 20 mL of carbonate-based electrolyte was added to the cell. The active surface area of ​​the cathode was 25.5 cm². 2 The galvanostatic electrolysis was carried out at room temperature, at an anode rotation speed of 50 rpm and a constant current density of 4 mA / cm². 2 for 22 min. Figure 9 shows the variation of the cell potential as a function of time.

[0158] The resulting electrodeposited lithium was cleaned and calendered following the same steps as in Example 4, before thickness measurement, revealed a Li thickness of approximately 9 µm. The appearance of the deposit before and after calendering is shown in Figures 10A and B, while Figure 11 shows the cross-section of the calendered Li under a scanning electron microscope.

[0159] The Li obtained was then used as the negative electrode in a rechargeable Li battery. First, a 14 mm diameter lithium anode disc was cut between two sheets of PP from the calendered lithium.

[0160] A cathode was prepared by mixing LFP with PVDF, DENKA black, and graphite in NMP in proportions of 89% w / w, 5% w / w, 3% w / w, and 3% w / w, respectively, using a Thinky™ centrifugal mixer. The resulting suspension was then applied to carbon-coated aluminum and dried at 120°C. The resulting cathode sheet was then dried again at 120°C under vacuum for 12 hours.

[0161] A 14 mm diameter disc was cut from the cathode foil and mounted in a stainless steel CR2032 button cell. The previously described calendered Li cathode and anode were separated by a Celgard™ 3501 membrane. The cell was filled with 60 µL of 1.7 M LiFSI salt dissolved in a DME-TTE mixture (molar ratio 1.2:3).

[0162] The cell was cycled at 25°C with a charge / discharge rate of C / 24 for one training cycle, then at a rate of C / 10 for two additional training cycles, and finally cycled at a discharge rate of 1C and a charge rate of C / 3 for stability testing. Potential limits were set at 2 V and 4 V vs. Li + / Li°. Figure 12 compares the cycling stability of the Li obtained and of a Li sheet prepared by PVD. Example 8: Electrodeposition of a thin film of Li onto a treated copper foil in a membrane-free electrochemical cell

[0163] Electrodeposition of a thin Li film was carried out on different types of sheets for improved Li deposition.

[0164] The deposition was carried out using the same experimental setup as that used in Example 7 (membrane-free cell, LFP-coated rotating anode and the same electrolyte formulation).

[0165] The electrochemical properties of each lithium sample obtained were compared to commercially available PVD-coated lithium cathode as shown in Example 7. Figure 13 illustrates the cyclic stability of each sample. The electrodeposited lithium exhibited performance better than, or similar to, that of PVD-coated lithium. Example 8.1: Copper-silver substrate

[0166] A cathode consisting of a thin 9 µm copper foil coated with a thin layer of silver was prepared. The silver coating was prepared by washing the copper foil in acetone, soaking the foil in 1 M sulfuric acid for 1 min at room temperature, rinsing the acid with water, and Finally, the cleaned copper foil was immersed in an autocatalytic silver plating solution for 10 seconds. The resulting treated current collector was then dried before being used as a current collector in the membrane-free cell described in Example 7. The applied current was 4 mA / cm². 2 for 22 min with an active cathode area of ​​25.5 cm² 2 The evolution of the cell potential as a function of time is shown in Figure 14. The resulting electrodeposited lithium was cleaned and calendered according to the same steps as in Example 7 before thickness measurement, which revealed a Li thickness of approximately 6.5 µm, and electrochemical cycling. Example 8.2: Brass foil substrate

[0167] A brass foil was used to demonstrate the lithophilic properties of this alloy. The foil was a commercially available brass foil composed of 68 w / w Cu and 32 w / w Zn. After being cleaned with acetone and thoroughly dried, the 20 µm brass foil was used as the cathode in a Li electrodeposition cell under conditions similar to those of the silver-plated Cu foil described above. The evolution of the cell potential over time is shown in Figure 15. The resulting electrodeposited lithium was cleaned and calendered using the same steps as in Example 7 before thickness measurement, which revealed a Li thickness of approximately 12 µm, and electrochemical cycling. Example 8.3: 3D Textured Ni Foil Substrate

[0168] Li electrodeposition was performed on a commercially available textured Ni foil. The foil has a high surface area due to its 3D textured Ni dendritic structure. Similar to previous examples, the 3D foil was used as the cathode substrate. Deposition was carried out under the same conditions as for Cu-Ag or brass foil. The evolution of the cell potential over time is shown in Figure 16. The resulting electrodeposited lithium was cleaned and calendered using the same steps as in Example 7 before thickness measurement, which revealed a Li thickness of approximately 9 µm. Example 9: Electrodeposition of thin Li onto a metallized polymer in a membrane-free electrochemical cell

[0169] A metallized polymer was used as an electrodeposition substrate. The results show that this substrate can be used successfully.

[0170] The metallized polymer consisted of a 50 µm thick polyethylene terephthalate film coated with a thin Cu film deposited by physical vapor deposition (PVD).

[0171] The electrodeposition of Li was carried out in the same electrolyte and with the same configuration as in Example 8.2. A current density of 4 mA / cm² was achieved. 2 was applied for 13 min.

[0172] The evolution of the cell potential as a function of time is shown in Figure 17. The resulting Li sheet is shown in Figure 18. Example 10: Relithiation of the delithiated LFP anode of the Tait cell above

[0173] The delithiated LFP (FP) electrode resulting from the anodic discharge of LFP during the electrodeposition of Li described in Example 8.2 on a brass substrate was relithied in an aqueous LiHCO3 electrolyte 3Next, the relithiated electrode was used to produce Li. We confirmed the complete relithiation of the electrode and its successful reuse to produce Li.

[0174] The initial LFP electrode used during the Li plating of example 8.2 consisted of a 25 cm² stainless steel disc 2 and 20 mm thick coated with a mixture of LFP, conductive carbon and PVDF as described in Example 7, with an active charge of 22.4 mg / cm² 2 .

[0175] Considering a theoretical capacity of 170 mAh / g LFP, the LFP anode has a charge capacity of 97 mAh. The total electrodeposition charge is 36.7 mAh, corresponding to a delithiation extent of approximately 38% of the LFP anode. The evolution of the cell potential over time is shown in Fig. 19.

[0176] This delithiated LFP electrode (called the FP electrode) was recovered from the cell in Example 8.2 and rinsed three times in THF, once in hexane, and then dried before relithiation. The FP electrode was mounted on a stirrer and then immersed in a 0.5 M UHCO3 solution at near-neutral pH. This electrolyte was prepared from ACS-grade lithium carbonate by solubilizing the lithium salt in demineralized water in a pressure reactor under a CO2 partial pressure of 2 atm. A platinum-plated titanium lattice approximately 25 cm long 2 was used as the anode. A constant current of 4 mA / cm 2Current was applied between the cathode and anode. The cathodic potential was monitored with an Ag / AgCl reference electrode (3.5 M KCl at 0.198 V vs NHE) immersed next to the cathode. The current was stopped when the cathodic potential fell below -0.5 V relative to NHE, indicating a high degree of lithiation (after 21 minutes).

[0177] The cumulative Coulomb charge corresponds to 34.3 mAh. Figure 19 shows the current density and cathode potential as a function of time. Electrode relithiation was confirmed by FTIR, as shown in Figure 20. Therefore, the electrode spectra before and after relithiation correspond to the partially relithiated and fully relithiated states of the LFP, respectively. The electrode spectra after relithiation are similar to those of the unrelithiated LFP, confirming complete electrode relithiation.

[0178] The previously relithiated LFP electrode was reused as an anode in a second Li electrodeposition. The electrochemical conditions were similar to those used in Example 7. The evolution of the cell potential, shown in Figure 21, is similar to that obtained in Example 8.2, confirming the possibility of reusing the same LFP anode after an aqueous relithiation step. Example 11: Relithiation of an LTO anode in aqueous solution

[0179] This example demonstrates the relithiation of an LTO (Li isO^) electrode in aqueous solution. We have confirmed complete relithiation.

[0180] An LTO-based anode consisting of a thin layer of LTO applied to an AI-C sheet was electrochemically relithied in an aqueous electrolyte. The electrolyte consisted of a 25 M aqueous LiFSI solution with 25% v / v dimethoxyethane adjusted to pH 8 with 2 M LiOH. The working electrode was made by gluing a piece of LTO-coated foil approximately 4 cm long. 2 on a glass tile with a double-sided AI sheet. A square mask of PVDF tape was applied to cover the edges of the WE, leaving a 3.5 cm active area 2 exposed to the electrolytic solution. The counter electrode consisted of a platinum lattice approximately 4 cm in diameter. 2 A current of 4 mA / cm 2 A current was applied between the cathode and the anode for 60 min while the working electrode potential was monitored with a platinum wire pseudo-reference electrode. The evolution of the working electrode potential is shown in Figure 22.

[0181] Once relithiated, the working electrode was rinsed with ethanol and allowed to dry for a few minutes at 60°C. Relithiation was confirmed by performing linear-scan anodic voltammetry in the same electrolyte and using the same experimental setup. In this case, the working electrode potential was swept from 0 V relative to the OCV to 1.2 V relative to the reference electrode at a sweep rate of 0.1 V / s. The resulting voltammetric curve, shown in Figure 23, exhibits a large oxidation peak centered at -0.357 V relative to Pt, corresponding to the oxidation of Li₄TiO₂ to Li₄TiO₂⁻. Example 12: Additives for the electrodeposition of thin Li

[0182] An additive can be added to the electrolyte to improve the appearance and properties of the lithium thin film. With this in mind, we tested various additives that could enhance the properties of lithium. We confirmed that the use of these additives facilitates the electrodeposition of lithium.

[0183] The experiments consisted of electrodeposition of lithium in button cells using a 4.5 µm thick and 16 mm diameter copper foil as the cathode, covered by a 50 µm thick polypropylene mask with an 8 mm internal diameter. This mask created a gap between the cathode and the membrane, separating the two electrodes and simulating deposition in a membraneless electrochemical cell. The anode consisted of an LFP film covered with an aluminum foil as shown in Example 7. Deposition was performed at a current density of 4 mA / cm². 2 for 10 minutes.

[0184] A series of additives were added to a basic electrolyte composed of a 50 / 50 EC and DEC electrolytic salts, UCF3COO and LiFSI, at concentrations of 0.6 M and 0.4 M, respectively. As shown in Figure 24, the peak potential of the initial nucleation phase decreased after the addition of 0.2 M VC, 0.01 M LiDFOB, or 0.1 M CsPFe. This will result in more uniform surface coverage of the Cu substrate during Li electrodeposition. Example 13: Synthesis of n-Butyl Li from an electrodeposited Li

[0185] The Li obtained by electrodeposition was successfully used to synthesize n-butyllithium, a commonly used organometallic compound.

[0186] To achieve this, a first electrodeposition was carried out in a button cell at a current density of 0.5 mA / cm 2 for a total charge of 1.44 mAh / cm² 2on a copper substrate 4.5 µm thick. After electrodeposition, the resulting 16 mm diameter Li electrode was recovered from the button cell in a glove box filled with Ar, cleaned of electrolyte residues with THF followed by DEC, and dried under vacuum at 25°C overnight in a dry room.

[0187] To evaluate the efficiency of n-butyllithium formation, a titration curve was developed to accurately determine the concentration of n-butyllithium in n-hexane. Therefore, dilute solutions of n-butyllithium were prepared at four different concentrations (0.005 M / L, 0.01 M / L, 0.015 M / L, and 0.025 M / L) using a commercially available 1.6 M / L solution. A 25 µL volume of a saturated solution of n-phenanthroline in a mixture of n-hexane and toluene was added to 2 mL of the previously prepared n-butyllithium solution. A 2% v / v dilute solution of 2-propanol in n-hexane served as the titrant and was added dropwise until a bright yellow endpoint was reached. The volumetric concentration of the titrated solution relative to the sample solution was plotted against the calculated concentration of each dilute n-butyllithium solution, resulting in a straight line with an R 2of 99.99%, as shown in Figure 25.

[0188] A 2% v / v dilute solution of n-butyl chloride was prepared in dried n-hexane to synthesize n-butyllithium from electrodeposited lithium. A 14 mm diameter subsample was cut from the dried lithium electrode and placed in a flask. The charge of the lithium deposit was measured at 0.78 mg. A magnetic stirrer was added to the flask containing 0.435 mL of the dilute butyl chloride solution. The flask was sealed and stirred for 15 minutes, after which the solution was transferred to a 10 mL volumetric flask. The setup was rinsed three times with n-hexane and transferred to the volumetric flask to recover any remaining n-butyllithium from the flask and solid residue. Once the flask was filled with n-hexane, a 5 mL sample was taken from the volumetric flask for titration of n-butyllithium with 2-propanol. In this regard, 20 pil of saturated n-phenanthroline solution were added to the 5 ml.The resulting dark red color indicates the presence of n-butyllithium. Propanol solution was added dropwise until a bright yellow endpoint was reached (0.070 mL in this case). Titration revealed that 0.42 mg of Li reacted with butyl chloride, corresponding to a reaction efficiency of 67%. Example 14: Pre-lithiation of a Li intercalation anode

[0189] The following example demonstrates the application of the above electrochemical method for pre-lithiating lithium intercalation anodic materials in order to reduce lithium losses induced during formation cycles. These lithium losses were significantly reduced in graphite and SiOx anodes following pre-lithiation.

[0190] In the first case, a commercially available graphite anode made of a lithium intercalation layer composed of 94% by weight synthetic graphite coated onto an 8 µm copper foil was used. Its active mass was 6.7 mg / cm³ 2 offering a specific capacity of 2.27 mAh / cm² 2 Button cells composed of 16mm diameter electrodes taken from the graphite anode, of a membrane Celgard™ and a positive LFP electrode (such as the one used in Example 12) were assembled for pre-lithiation. The electrolyte used was the same as the base electrolyte from Example 12. These cells were then subjected to a constant current load to pre-lithiate the graphite electrode at a current density of 0.5 mA / cm². 2 for a total charge of 0.36 mAh / cm² 2 or 0.48 mAh / cm² 2These coulombic charges correspond respectively to 16% and 21% of the initial capacity of the graphite anodes. The resulting galvanostatic curves are shown in Figure 26.

[0191] Similarly, a commercially available silicon oxide anode made of a Li intercalation layer composed of 81% by weight of SiO₂ x 4% by weight of carbon nanotube and 15% by weight of polyimide were used. The total specific capacitance of the anode is 2.52 mAh / cm² 2 16mm diameter electrodes were taken from the SiO anode x for the prelithiation in button cells as described previously. The applied coulombic charges were 0.75 mAh / cm². 2 or 1.0mAh / cm² 2 corresponding respectively to 30% and 40% of the total capacity of the SiO₂ anode x The galvanostatic curves thus obtained are shown in Figure 27.

[0192] The initial capacitance losses of each pre-lithianed anode were compared to their corresponding virgin anode by electrochemical cycling with respect to a positive LFP electrode. The limiting potential galvanostatic cycling protocol began with a C / 24 formation charge-discharge cycle followed by two C / 10 formation cycles and then a stability test at a C / 3 charge and a 1C discharge. The potential limits were set between 2V vs. Li and 4V vs. Li for graphite and between 2V vs. Li and 3.8V vs. Li for the SiO₂ anodes. x Figure 28 compares the cycling reversibility of the first cycle of formation of virgin and pre-lithitized graphite anodes. While the capacitance loss of the virgin electrode reaches 21%, it decreases to 3% for the pre-lithiated anode at 15% capacitance, while reversibility becomes complete for the pre-lithiated anode at 20% capacitance. Similarly, the pre-lithiation of SiO₂ anodes xThis allowed for an improvement in initial capacitance losses, decreasing from 68% for the virgin electrode to only 32% for the 30% pre-lithianed electrode and 11% for the 40% pre-lithianed electrode. Figure 29 compares the cycling reversibility of the first cycle of SiO₂ anode formation. x virgin and pre-lithia.

[0193] The scope of the claims should not be limited by the preferred embodiments presented in the examples, but should receive the broadest interpretation compatible with the description as a whole. REFERENCES

[0194] This description refers to a number of documents, the contents of which are incorporated herein in their entirety for reference. These documents include, but are not limited to, the following: • Lee et al., “Synthesis of Lithium Thin Film by Electrodeposition from Ionic Liquid”, Applied Mechanics and Materials, 217-219, November 2012, pp 1049-1052 • Porthault et al., “Electrodeposition of lithium metal thin films and its application in all-solid-state micro batteries”, Electrochimica Acta 194 (2016) 330-337 • Coyle et al., Recycle of End-of-Life NMC 111 Cathodes By Electrochemical Relithiation, 2019 Meet. Abstr. MA2019-02 449 • Montoya et al., Relithiation of Cathode Materials for the Recycling of Lithium-Ion Batteries, 2019 Meet. Abstr. MA2019-02 444 • Shi et al., Ambient-Pressure Relithiation of Degraded LixNio5Coo2Mno3O2 (0 <x<1) via eutectic solutions for direct regeneration of lithium-ion battery cathodes, advanced energy materials, volume 9, issue 20, may 23, 2019, 1900454• Zhou et al., Direct recovery of scrapped LiFePO4 by a green and low-cost electrochemical re-lithiation method, Green Chem., 2022,24, 6278-6286 • Lahtinen et al., Reuse of LiCoO2 Electrodes Collected from Spent Li-Ion Batteries after Electrochemical Re-Lithiation of the Electrode, ChemSusChem 2021 , 14, 1- 12 • Zhang et al., Electrochemical Relithiation for Direct Regeneration of UCOO2 Materials from Spent Lithium-Ion Battery Electrodes, ACS Sustainable Chem. Eng. 2020, 8, 31, 11596-11605 • Holtstiege et al., Pre-Lithiation Strategies for Rechargeable Energy Storage Technologies: Concepts, Promises and Challenges, Batteries 2018, 4(1), 4 • WO 2019 / 113534 • WO 2019 / 070896 A1 • WO 2017 / 095989 A1 • WO 2021 / 092692 • US20220328800A1 • US20210091426A1 • US20210381115A1 • US20180040914A1 • US20160351889A1 • CN112216819B • CN110504451 B • EP3358046B1 • DE102018207391 A1

Claims

CLAIMS 1. Relithiated Li intercalation material for producing metallic Li or an alloy thereof or for pre-lithiating an electrode material.

2. Use of a relithiated Li intercalation material to produce metallic Li or an alloy thereof or to pre-lithiate an electrode material.

3. The material / use according to claim 1 or 2, for producing metallic Li or the alloy thereof, preferably for producing metallic Li, preferably in which the metallic Li or the alloy thereof is in the form of a film, preferably in which the metallic Li or the alloy thereof is produced by electrodeposition.

4. The material / use according to claim 1 or 2, for pre-lithing an electrode material, preferably for pre-lithing an anode material, more preferably for pre-lithing graphite, Si, silicon oxide (SiO x), a silicon-carbon composite, carbon nanotubes, or a mixture thereof.

5. The material / use according to any one of claims 1 to 4, wherein the relithiated Li intercalation material is a lithium phosphate or a lithium oxide, preferably: • Li w Fe PO4 (wherein w < 1, 1, preferably w is 1), • Li w Fei-xMn x PO4 (wherein w < 1, 1, preferably w is 1; 0 < x < 1, preferably 0.2 < x < 0.4), • LiwMn2O4 (in which ws 1,1, preferably w is 1), • LiwMn15Nio5O4 (in which w < 1.1, preferably w is 1), • Li4+ z Tis012 (in which 0 < z < 3), or • NMC (Li w Nii- x -yMnxCoyO2, wherein w < 1,3, preferably w is 1; 0 S x ^ 1, 0 S y < 1, and 0 S z < 1, and M is Al, Mg, Ti, Nb, Zr, W, Mo, Y, La, Ta or a mixture thereof).

6. The material / use according to claim 5, wherein the relithiated Li intercalation material is Li w FePO4.

7. The material / use according to any one of claims 1 to 6, wherein the relithiated Li intercalation material has been obtained from used electrodes and then relithiated or wherein the relithiated Li intercalation material has been used to produce metallic Li or an alloy thereof or to pre-lithiate an electrode material and then relithiated.

8. The material / use according to any one of claims 1 to 7, wherein the relithiated Li intercalation material has recovered at least 50%, preferably at least 75%, more preferably at least 85%, even more preferably at least 95%, and most preferably at least 99% of the previously deintercalated lithium ions.

9. A production anode for producing metallic Li or an alloy thereof or for pre-lithiating an electrode material, the production anode comprising a relithiated Li intercalation material.

10. Use of a production anode comprising a relithiated Li intercalation material for producing metallic Li or an alloy thereof or for pre-lithiating an electrode material.

11. The production / use anode according to claim 9 or 10, wherein the relithiated Li intercalation material is as defined in any one of claims 1 to 8.

12. The production anode / use according to any one of claims 9 to 11, for producing metallic Li or the alloy thereof, preferably for producing metallic Li, preferably wherein the metallic Li or the alloy thereof is in the form of a film, preferably wherein the metallic Li or the alloy thereof is produced by electrodeposition.

13. The production anode / use according to claim 12, wherein the anode is for an electrolytic reaction for the production of Li.

14. The production anode / use according to claim 12 or 13, wherein the production anode further comprises a current collector and the relithiated Li intercalation material is deposited on the current collector.

15. The production / use anode according to claim 14, wherein the current collector is a metal foil, preferably made of Cu, AI, stainless steel, Ti or Ni, or is made of a conductive carbon material, or is a polymer-based current collector.

16. The production / use anode of claim 14 or 15, wherein the current collector is coated with a primer layer, such as a carbon-containing paint.

17. The production / use anode according to any one of claims 14 to 16, wherein the current collector is a metal foil made of stainless steel or AI, preferably is a current collector comprising a carbon-coated AI foil.

18. The production anode / use according to any one of claims 9 to 11, intended for pre-lithing an electrode material, preferably intended for pre-lithing an anode material, more preferably intended for pre-lithing graphite, Si, silicon oxide (SiO x ), a silicon-carbon composite, carbon nanotubes, or a mixture thereof.

19. The production anode / use according to any one of claims 9 to 18, wherein the production anode is in the form of a film.

20. A production electrolysis cell for producing metallic Li or an alloy thereof or for pre-lithiating an electrode material, the production electrolysis cell comprising: a relithiated Li intercalation material used as a production anode, a current collector or said electrode material used as a production cathode, and a production electrolyte between the production cathode and the production anode, wherein the production electrolyte comprises a production lithium salt dissolved in a production solvent.

21. Use of a production electrolysis cell for producing metallic Li or an alloy thereof or for pre-lithiating an electrode material, wherein the production electrolysis cell comprises: a relithiated Li intercalation material used as a production anode, a current collector or said electrode material used as a production cathode, and a production electrolyte between the production cathode and the production anode, wherein the production electrolyte comprises a production lithium salt dissolved in a production solvent.

22. The production / use electrolysis cell of claim 20 or 21, wherein the relithiated Li intercalation material is as defined in any one of claims 1 to 8.

23. The production electrolysis cell / use according to any one of claims 20 to 22, wherein the production anode is as defined in any one of claims 9 to 19.

24. The production / use electrolysis cell according to any one of claims 20 to 23, for producing metallic Li or the alloy thereof, preferably for producing metallic Li, preferably wherein the metallic Li or the alloy thereof is in the form of a film, preferably wherein the metallic Li or the alloy thereof is produced by electrodeposition, and wherein the current collector is used as a production cathode.

25. The production / use electrolysis cell according to claim 24, wherein the current collector used as the production cathode is in the form of a sheet.

26. The production / use electrolysis cell of claim 24 or 25, wherein operating conditions, such as agitation and / or temperature control, are used to modify the morphology of said produced metallic Li or alloy thereof.

27. The production electrolysis cell / use according to any one of claims 24 to 26, wherein the current collector used as the production cathode is made of Cu, AI, protected aluminum, C, stainless steel, Ti, Zn, or Ni or an alloy thereof, or is a metallized polymer-based current collector, or a mixture thereof.

28. The production / use electrolysis cell according to any one of claims 24 to 27, wherein the current collector used as the production cathode is made of Cu or Al protected.

29. The production / use electrolysis cell according to any one of claims 24 to 28, wherein the current collector used as the production cathode is protected by a protective layer.

30. The production electrolysis cell / use according to any one of claims 24 to 28, wherein the current collector used as the production cathode is not protected.

31. The production electrolysis cell / use according to any one of claims 24 to 30, wherein the surface of the current collector used as the production cathode is treated or modified to improve its lithiophilicity.

32. The production electrolysis cell / use according to any one of claims 24 to 31, wherein the surface of the current collector used as a production cathode is treated or modified to have a 3D structure to improve the electrochemical performance of the Li layer in a battery or to increase its reaction rate, for example when used for the preparation of an organolithium compound.

33. The production electrolysis cell / use according to any one of claims 24 to 32, for producing said alloy; preferably, the alloy comprising about 80% w / w or more Li, more preferably about 85% w / w or more Li, even more preferably about 90% w / w or more Li, even more preferably about 95% w / w or more Li, based on the total weight of the alloy.

34. The production electrolysis cell / use according to claim 33, wherein the production electrolyte further comprises an alloying salt, the alloying salt preferably being a salt of one or more of the following elements: Na, K, Mg, Ca, a transition metal, Al, Ga or Sn, preferably a salt of Al or Mg.

35. The production electrolysis cell / use according to claim 34, wherein the alloying salt is a (flurosulfonyl)(trifluoromethanesulfonyl)imide salt, a 2-trifluoromethyl-4,5-dicyanoimidazolate (TDI) salt, a 4,5-dicyano-1,2,3-triazolate (DCTA) salt, a bis(pentafluoroethylsulfonyl)imide (BETI) salt, a difluorophosphate (DFP) salt, a chloride salt, a bromide salt, a fluoride salt, a hexafluoroarsenate (AsFe) salt, a fluoroalkylphosphate salt, a tetrakis(trifluoroacetoxy)borate salt, a bis(1,2-benzenediolato(2-)-O,O')borate salt, a difluoro(oxalato)borate salt, a nitrate salt, a trifluoroacetate salt, a hexafluorophosphate salt, a tetrafluoroborate salt, a bis(oxalate)borate (BOB), a perchlorate salt, a bis(trifluoromethanesulfonyl)imide (TFSI), a bis(fluorosulfonyl)imide salt (FSI), a triflate salt, or a salt with an anion of formula: BF2O4R (Rx = C2-4 alkyl).

36. The production electrolysis cell / use according to any one of claims 24 to 32, wherein the production electrolyte is free of alloying salt and the production electrolysis cell production / use is intended to produce metallic Li.

37. The production electrolysis cell / use according to any one of claims 20 to 23, intended to pre-lithiate an electrode material, preferably intended to pre-lithiate an anode material, more preferably intended to pre-lithiate graphite, Si, silicon oxide, or a mixture thereof, and wherein said electrode material is used as a production cathode.

38. The production electrolysis cell / use according to any one of claims 20 to 37, wherein the production lithium salt is lithium (flurosulfonyl)(trifluoromethanesulfonyl)imide, lithium 2-trifluoromethyl-4,5-dicyanoimidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA), lithium bis(pentafluoroethylsulfonyl)imide (LiBETI), lithium difluorophosphate (LiDFP), lithium chloride (LiCl), lithium bromide (LiBr), lithium hexafluoroarsenate (LiAsFe-, a lithium fluoroalkylphosphate [such as LiPF3(CF2CF3)3], lithium tetrakis(trifluoroacetoxy)borate (LiB(OCOCF3)4), bis(1,2-benzenediolato (2-)-O,O')lithium borate LiB(CeO2)2, lithium difluoro(oxalato)borate (LiBF2(C2C>4)), a compound of formula BF2C>4Rx' (R x= C2 alkyl), UCF3COO, LiF, LiNO3, LiPF6, LiBF4, LiBOB, LiCIO4, LiTFSi, CF3SO3U, LiFSi, or any combination thereof, preferably UCF3COO, LiF, UNO3, LiPFe, LiBF4, LiBOB, UCIO4, LiTFSi, CFsSOsLi, LiFSi, or any combination thereof.

39. The production electrolysis cell / use according to claim 38, wherein the production lithium salt is a combination of CF3SO3Ü and LiFSi.

40. The production electrolysis cell / use according to any one of claims 20 to 39, wherein the production electrolyte further comprises one or more additives, preferably one or more additives that modify the morphology and / or properties of metallic Li or alloy thereof, one or more additives that influence the phase nucleation energy, one or more additives that influence a deposition potential of lithium or alloy thereof, and / or one or more additives that influence the electrodeposition efficiency of Li; more preferably, the one or more additives are: an unsaturated cyclic carbonate such as vinylene carbonate (VC), a halogenated cyclic carbonate such as fluoroethylene carbonate (FEC), a nitrate, a Li polymerization agent comprising a saturated or unsaturated hydrocarbon chain, such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), a Li passivation compound, and / or an alkali salt of an organic acid, such as lithium difluoro(oxalate)borate (LiDFOB) or Li oxalate.

41. The electrolysis cell for production / use according to any one of claims 20 to 40, wherein the production solvent is an organic carbonate, an organic ester, an organic ether, an ionic liquid, or any combination thereof.

42. The production / use electrolysis cell of claim 41, wherein the production solvent is ethylene carbonate (EC), propylene carbonate (PC), fluoroethylene carbonate (FEC), gamma-butyrolactone (gBL), ethyl propionate, diethyl carbonate (DEC), dimethyl carbonate (DMC), ethylmethyl carbonate (EMC), dimethoxyethane (DME), fluoroether, tetrafluoroethyltetrafluoropropylether (TTE), tetraethylene glycol dimethyl ether (TEGDME), or any combination thereof.

43. The production electrolysis cell / use according to claim 42, wherein the production solvent is a combination of EC and DEC.

44. The production electrolysis cell / use according to any one of claims 20 to 43, wherein the production electrolysis cell is free of a membrane separating the production anode from the production cathode.

45. The production electrolysis cell / use according to claim 44, wherein the production electrolysis cell is in a roll-to-roll configuration.

46. ​​The production electrolysis cell / use according to claim 44 or 45, wherein the production electrolysis cell further comprises one or more calendering devices, such as pairs of calendering rolls, for example at fixed intervals.

47. A method of producing metallic Li or an alloy thereof or pre-lithiating an electrode material, the method comprising: a) providing a relithiated Li intercalation material, and b) carrying out a Li production electrolytic reaction in a production electrolysis cell, wherein the production electrolysis cell comprises: said relithiated Li intercalation material as a production anode, a current collector or said electrode material as a production cathode, and a production electrolyte between the production cathode and the production anode, wherein the production electrolyte comprises a production lithium salt dissolved in a production solvent,thereby enabling the electrodeposition of metallic Li or an alloy thereof onto the current collector used as a production cathode or introducing lithium into said electrode material thereby producing a pre-lithiated electrode and thereby enabling the production of a partially or completely delithiated Li intercalation material., 48. The method of claim 47, wherein the relithiated Li intercalation material is as defined in any one of claims 1 to 8.

49. A method according to claim 47 or 48, wherein the production anode is as defined in any one of claims 9 to 19.

50. A method according to any one of claims 47 to 49, wherein the production electrolysis cell is as defined in any one of claims 20 to 46.

51. A method according to any one of claims 47 to 50, wherein the electrolytic reaction for producing Li is carried out by regulating the cell potential either between the production anode and the production cathode, or between the cathode and a reference electrode.

52. A method according to any one of claims 47 to 50, wherein the electrolytic reaction for producing Li is carried out by regulating the cell current.

53. Method according to claim 52, in which the electrolytic reaction for producing Li in regulated current mode is carried out in direct mode, in pulsed mode, either simple (unidirectional), or reverse.

54. Method according to claim 52 or 53, in which the electrolytic reaction for producing Li in regulated current mode is carried out at a fixed frequency or under a variable frequency.

55. A method according to any one of claims 47 to 54, wherein step a) is carried out in a roll-to-roll configuration.

56. A method according to any one of claims 47 to 55, wherein step b) is carried out in a roll-to-roll configuration.

57. A method according to any one of claims 47 to 56, wherein the partially or completely delithiated Li intercalation material is a partially or completely delithiated lithium phosphate or lithium oxide, preferably Li w FePC>4, Li w M ^CU, Li4+ z TisOi2, or NMC (Li w Nii-x-yMnxCoyM z O2) partially or completely delithiated.

58. The method of claim 57, wherein the partially or completely delithiated Li intercalation material is Li w FePC>4 partially or completely delithiated.

59. A method according to any one of claims 47 to 58, wherein the relithiated Li intercalation material is washed, preferably washed and dried, before being used in step b).

60. A method according to any one of claims 47 to 59, wherein step a) comprises: a') providing a partially or fully delithiated Li intercalation material and a”) relithiating the partially or fully delithiated Li intercalation material, thereby producing a relithiated Li intercalation material.

61. The method of claim 60, further comprising step c) of repeating step a) and step b) a or several times, using in steps a') and a"), the partially or completely delithiated Li intercalation material produced in step b).

62. The method of claim 60 or 61, wherein the partially or completely delithiated Li intercalation material provided in step a') is the partially or completely delithiated Li intercalation material produced in step b).

63. A method according to any one of claims 47 to 60, wherein the partially or completely delithiated Li intercalation material is obtained from recycled used batteries.

64. The method of any one of claims 47 to 63, wherein step a”) comprises performing a relithiation electrolytic reaction in a relithiation electrolysis cell, wherein the relithiation electrolysis cell comprises: the partially or completely delithiated intercalation material as a relithiation cathode, a relithiation anode, and a relithiation electrolyte between the relithiation cathode and the relithiation anode, wherein the relithiation electrolyte comprises a relithiation lithium salt dissolved in a relithiation solvent, thereby relithiating the partially or completely delithiated intercalation material and producing the relithiated Li intercalation material.

65. The method of claim 64, wherein the relithiation solvent is water.

66. The method of claim 64 or 65, wherein the relithiation anode is made of a material compatible with the anodic reaction taking place at the relithiation anode, preferably compatible with an oxygen evolution reaction.

67. A method according to any one of claims 64 to 66, wherein the relithiation anode is made of lead, platinum, titanium, another inert metal, or an alloy thereof, or graphite.

68. A method according to any one of claims 64 to 67, wherein the relithiation anode is a dimensionally stable anode.

69. A method according to any one of claims 64 to 68, wherein the relithiation electrolyte further comprises one or more additives; preferably one or more additives which improve the electrical conductivity properties of the relithiation electrolyte; more preferably a salt comprising an alkali cation other than Li or an alkaline earth cation (preferably potassium or magnesium) and an anion compatible with the relithiation electrolysis reaction (preferably sulfate or bicarbonate).

70. A method according to any one of claims 64 to 69, wherein the relithiation salt is U2CO3, UHCO3, LiOH, UNO3, LiOH, U2SO4, UCH3COO, LiFSI, LiTFSI or U2C2O4, or a mixture thereof, preferably the relithiation salt is LiHCOs, Li2SO4, or a mixture thereof, preferably the relithiation salt is U2SO4.

71. A method according to any one of claims 64 to 70, wherein the relithiation salt is an inexpensive lithium salt.

72. A method according to any one of claims 64 to 71, wherein the relithiation solvent is water, and the relithiation salt is a water-soluble relithiation salt.

73. A method according to any one of claims 64 to 72, wherein the relithiation salt is a water-soluble relithiation salt which has a water solubility greater than the water solubility of UHCO3.

74. The method of claim 73, wherein the water-soluble relithiation salt that has a water solubility greater than the water solubility of UHCO3 is UNO3, U2SO4, or UCH3COO.

75. A method according to any one of claims 64 to 74, wherein further comprising a step of producing the relithiation salt in the relithiation electrolysis cell.

76. The method of claim 75, comprising adding a lithium precursor and a reagent to the relithiation electrolysis cell and allowing the lithium precursor and reagent to react to form the relithiation salt.

77. The method of claim 76, wherein the lithium precursor and the reagent are added to a salt forming compartment of the relithiation electrolysis cell which is in fluid communication with a main compartment of the relithiation electrolysis cell; the main compartment comprising the relithiation cathode and the relithiation anode.

78. A method according to any one of claims 64 to 74, wherein the relithiation salt is prepared before being added to the relithiation electrolysis cell.

79. The method of claim 78, further comprising reacting a lithium precursor and a reactant in a reactor separate from the relithiation electrolysis cell to obtain the relithiation salt, and then adding the relithiation salt to the relithiation electrolysis cell.

80. A method according to any one of claims 76, 77 and 79, wherein the lithium precursor is Li2CC>3, LiOH or a mixture thereof, preferably U2CO3.

81. A method according to any one of claims 76, 77, and 79-80, wherein the reactant is CO2, H2SO4, nitric acid, acetic acid, oxalic acid, or an acid form of a sulfonyl imide salt, or a mixture thereof, preferably CO2 or H2SO4 or a mixture thereof.

82. The method of claim 81, wherein the reactant is CO2.

83. The method of claim 81, wherein the reactant is H2SO4.

84. A method according to any one of claims 64 to 83, wherein the electrolytic relithiation reaction is carried out by regulating the cell potential either between the relithiation anode and the relithiation cathode, or between the relithiation cathode and a reference electrode.

85. A method according to any one of claims 64 to 83, wherein the electrolytic relithiation reaction is carried out by regulating the cell current.

86. The method of claim 85, wherein the electrolytic reaction in regulated current mode can be carried out in forward mode, in pulsed mode, either simple (unidirectional), or reverse.

87. The method of claim 85 or 86, wherein the electrolytic reaction in regulated current mode can be carried out at a fixed frequency or at a variable frequency.

88. A method according to any one of claims 47 to 63, wherein step a”) comprises (i) adding the partially or completely delithiated intercalation material to a solution containing a reducing agent and a relithiation salt in a solvent; thereby relithiating the partially or completely delithiated intercalation material and producing the relithiated Li intercalation material.

89. The method of claim 88, further comprising (ii) separating the relithiated Li intercalation material from the solution; and (iii) electrochemically treating the solution separated in step (ii) to regenerate the reducing agent.

90. A method according to claim 88 or 89, wherein the relithiation salt is as described in any one of claims 70 to 74.

91. A method according to any one of claims 88 to 90, wherein the reducing agent is a reducing member of a redox couple having a redox potential lower than the redox potential of the partially or completely delithiated intercalation material.

92. Method according to claim 91, the redox couple comprises a Fe(lll) / Fe(ll) complex.

93. The method of claim 92, wherein the redox couple is [Fe(CN)6] 3 7Fe(CN)6] 4 ', [Fe(nta)] / [Fe(nta)]-, [Fe(tdpa)] 2 7Fe(tdpa)] 3 -, [Fe(edta)]7[Fe(edta)] 2 -, [Fe(citrate)] / [Fe(citrate)]-, [Fe(lll)-TEA] / [Fe(ll)- TEA] or [Fe(oxalate)]7[Fe(oxalate)].

94. A method according to any one of claims 88 to 93, wherein step (i) further comprises deoxygenating the solution.

95. A method according to any one of claims 88 to 94, wherein steps (i) and / or (iii) are carried out in the absence of oxygen.

96. A method according to any one of claims 88 to 95, further comprising adjusting the pH of the solution.

97. A method according to any one of claims 88 to 96, wherein the solvent is an aqueous solvent.

98. A method according to any one of claims 88 to 97, wherein step (iii) is carried out in an electrolytic cell by passing a current between at least one cathode and at least one anode.

99. The method of claim 98, wherein the electrolytic cell comprises at least one ionic or non-ionic separator installed between the anode and the cathode in order to protect the regenerated reducing agent.

100. The method of claim 98 or 99, wherein the electrolytic cell further comprises a system for maintaining the deoxygenated solution.

101. A method according to any one of claims 98 to 100, wherein step (iii) is carried out by regulating the cell potential either between the anode and the cathode or between the cathode and a reference electrode.

102. A method according to any one of claims 98 to 100, wherein step (iii) is carried out by regulating the cell current.

103. The method of claim 102, wherein the relithiation reaction in regulated current mode is carried out in forward mode, in pulsed mode, either simple (unidirectional), or reverse.

104. The method of claim 102 or 103, wherein the relithiation reaction in regulated current mode is carried out at a fixed frequency or at a variable frequency.

105. A method according to any one of claims 47 to 104, further comprising washing and drying the current collector with the metallic Li or alloy thereof or prelithiated electrode produced in step b).

106. A method according to any one of embodiments 47 to 105, further comprising using the current collector with the metallic Li or alloy thereof or the prelithiated electrode as a negative electrode in a primary or secondary Li battery, preferably a lithium-ion battery or an all-solid-state battery, as a source of metallic Li or alloy thereof for prelithiating an electrode material or as a source of metallic Li or alloy thereof for manufacturing an energy storage system.

107. The method of any one of claims 47 to 106, further comprising laminating the current collector with the metallic Li or alloy thereof to modify the morphology, density or thickness of a film of the metallic Li or alloy thereof.

108. A method according to any one of claims 47 to 107, further comprising treating the current collector with metallic Li or its alloy to have a 3D structure.

109. The method of any one of claims 47 to 108, further comprising treating the current collector with the metallic Li or alloy thereof to improve its electrochemical performance in batteries.

110. The method of any one of claims 47 to 105, further comprising using the current collector with metallic Li or alloy thereof as a lithium source to produce an organolithium compound.

111. The method of claim 110, wherein the metallic Li or alloy thereof is reacted with a reagent, such as an alkyl halide, to produce the organolithium compound.

112. The method of claim 110, further comprising transferring the current collector with the metallic Li or alloy thereof produced in step b) to a separate reactor, preferably in roll-to-roll mode, and reacting the metallic Li or alloy thereof with the reactant in said separate reactor to produce the organolithium compound.

113. A method according to any one of claims 47 to 112 for pre-lithing an electrode material, preferably for pre-lithing an anode material, more preferably for pre-lithing graphite, Si, silicon oxide, or a mixture thereof, and wherein said electrode material is used as a production cathode.

114. A method according to any one of claims 47 to 112 for producing metallic Li or an alloy thereof, preferably for producing metallic Li, preferably wherein the metallic Li or an alloy thereof is produced by electrodeposition, and wherein the current collector is used as a production cathode.

115. The method of claim 114, wherein the metallic Li or alloy thereof is electrolytically deposited on the current collector in the form of a film, preferably of high purity.

116. A lithium electrode comprising a current collector with metallic Li or an alloy thereof as produced by the method of any one of claims 47 to 115.

117. A lithium battery comprising the lithium electrode of claim 116, preferably wherein the battery is a lithium-ion battery or an all-solid-state battery.

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