Process for recycling disused and / or end-of-life metal-ion electrochemical accumulators), associated recycling apparatus and installation.

Abstract

Method for recycling disused and / or end-of-life metal-ion electrochemical accumulators, comprising a step of opening the accumulator packaging and the simultaneous extraction of the liquid electrolyte and / or a step of extracting the organic binder(s), associated recycling apparatus and installation. The invention relates to a method for recycling a disused and / or end-of-life metal-ion accumulator, which implements two steps which can be carried out independently and which consist of: - opening the packaging (flexible or case) of the accumulator, whether it is electrically charged or discharged, - extracting the electrolyte from the electrochemical bundle by circulating a dense fluid under pressure, and - extracting the binder, in particular PVDF, binding the insertion materials to the current collectors of the electrodes by circulating CO2 under supercritical conditions. Figure for abstract: Fig.6

Description

Title of the invention: Method for recycling metal-ion electrochemical accumulators that are no longer in use and / or at the end of their life), associated recycling apparatus and installation. Technical field

[0001] The present invention relates to the field of electrochemical accumulators, and more particularly to metal-ion accumulators.

[0002] The invention aims mainly to propose a reliable and easy solution for extracting the liquid electrolyte and the binders constituting the electrochemical bundles of used and / or end-of-life accumulators, with a view to recycling the materials of interest from the bundles.

[0003] Although described with reference to a Lithium-ion accumulator, the invention applies to any metal-ion electrochemical accumulator, i.e. also sodium-ion, Magnesium-ion, Aluminum-ion accumulators, etc., or more generally to any electrochemical accumulator, in particular Ni-Cd, Pb, etc. accumulators.

[0004] An end-of-life accumulator or module or battery pack, concerned by the method according to the invention, may have been on-board or stationary. For example, the fields of electric and hybrid transport and network-connected storage systems may be envisaged within the scope of the invention.

[0005] By "electrochemical beam" is meant here and within the framework of the invention, the electrochemical core of an accumulator comprising at least one electrochemical cell consisting of a liquid electrolyte constituent, where appropriate impregnating an electronic insulating and ionic conducting separator, between a positive electrode or cathode and a negative electrode or anode, a current collector connected to the cathode, a current collector connected to the anode. Prior art

[0006] Currently, lithium electrochemical accumulators are used and recommended in many on-board applications, such as so-called all-electric and hybrid vehicles, so-called light electric vehicles (bicycles, scooters, etc.) or even portable applications (computers, telephony, camcorders, cameras, satellite positioning systems (GPS)...).

[0007] The market for Li-ion batteries is currently experiencing strong growth due to new applications linked mainly to the emergence and development of hybrid vehicles, all-electric vehicles, and the continued development of portable electrical devices.

[0008] Increasing environmental constraints, in particular Directive 2006 / 66 / EC of 6 September 2006, oblige battery producers to take responsibility for recycling end-of-life batteries that they have marketed.

[0009] Particular attention is paid to the problem of resources required for developing technologies, in particular rare and strategic resources.

[0010] The recycling of batteries and accumulators is therefore a major issue for the transition and energy independence in France, Europe and the world, accumulators that have reached the end of their life representing an important source of materials of interest, such as Co, Ni, Li, etc., commonly called urban mining. In other words, among the end-of-life strategies for lithium-ion batteries, the recycling of used batteries is a solution for achieving sustainable development and minimal pollution of the environment.

[0011] With this in mind, the European Parliament validated in June 2023 an update of Directive 2006 / 66 / EC aimed in particular at imposing minimum levels of cobalt, lead and lithium from waste recovery in newly manufactured accumulators.

[0012] As illustrated schematically in Figures 1 and 2, a lithium-ion battery or accumulator usually comprises an electrochemical bundle comprising at least one electrochemical cell consisting of an electrolyte constituent 1, which may be impregnated in an electronic insulating and ionic conducting separator, between a positive electrode or cathode 2 and a negative electrode or anode 3, a current collector 4 connected to the cathode 2, a current collector 5 connected to the anode 3 and finally, a packaging 6 arranged to contain the electrochemical cell with sealing while being crossed by a part of the current collectors 4, 5.

[0013] The architecture of conventional lithium-ion batteries comprises an anode, a cathode and an electrolyte. Several types of conventional architecture geometry are known:

[0014] - a cylindrical geometry as disclosed in the patent application US2006 / 0121348;

[0015] - a prismatic geometry as disclosed in US patents 7348098, US 7338733;

[0016] - a stacking geometry as disclosed in the patent applications US2008 / 060189, US 2008 / 0057392, and US patent 7335448.

[0017] These different types of geometry are also described in publication [1].

[0018] The electrolyte constituent 1 may be in solid, gel or liquid form. In this latter form, the constituent may comprise a polymer, ceramic or microporous composite separator soaked with organic electrolyte(s) or Ionic liquid type that allows the movement of the lithium ion from the cathode to the anode for charging and vice versa for discharging, which generates the current. The organic liquid electrolyte is made with a formulation allowing to obtain a wide window of electrochemical stability and a high ionic conductivity:[2]. Thus, it is generally made up of a mixture of organic, non-aqueous solvents and lithium salts, as well as additives to improve performance, such as the formation and growth of electrode / electrolyte interfaces (SEI), the limitation of secondary reactions, etc.Electrolytes can be composed of a binary or ternary mixture based on cyclic carbonates (ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate), linear or branched (dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), dimethoxyethane) in various proportions in which one or more ionic conductive lithium salts are dissolved, such as LiPF6, LiCF3SO3, LiFSI, LiTDI, LiDFOB, LiBF4, LiC104, etc.

[0019] The positive electrode or cathode 2 is made of lithium cation insertion materials which are generally composite. The cathode is made mainly of transition metal oxides (Cobalt, Nickel, Manganese) or polyanionic compounds ([PO4]3).

[0020] The insertion materials used are lithium iron phosphate LiFePO4, lithium cobalt oxide LiCoO2, lithium manganese oxide, optionally substituted, LiMn20 4 or transition metal oxide, such as lamellar materials for example, a material based on LiNixMnyCozO2 with x+y+z = 1, such as LiNio.33Mno.33Coo.3302 or LiNio.8Mn0.iCoo.i02,, or a material based on nickel cobalt aluminum oxide type LiNixCoyAlzO2 with x+y+z = 1, such as LiNio.8Co0.i5Alo.o502.

[0021] Li-ion batteries are commonly referred to by acronyms that refer to the chemical elements that make up the cathode: NMC for nickel-manganese-cobalt, LCO for lithium-cobalt oxide, LFP for lithium-iron phosphate or LMO for lithium-manganese oxide.

[0022] NMC type cathodes are the most used to date because they are the ones which allow the best energy density to be obtained (between 150 and 200 Wh.kg-1): [3].

[0023] A polymer binder makes it possible to create adhesion between the current collector 4 and the active material of cathode 2. The most commonly used binder for cathode 2 is polyvinylidene fluoride (PVDF). A binder based on poly(methyl methacrylate) (PMMA) or carboxymethylcellulose (CMC) can also be found.

[0024] The negative electrode or anode 3 is very often made of graphite carbon or LqTiOsOn (titanate material), possibly also based on silicon or composite formed from silicon. This negative electrode, like the positive electrode, can also contain electronically conductive additives as well as polymer additives that give it mechanical properties and electrochemical performances appropriate to the lithium-ion battery application or its implementation process. A carbon graphite anode 3 presents an interesting balance between a relatively low cost, a moderate energy density and a long service life, compared to any other intercalation type anode material.

[0025] A polymer binder makes it possible to create adhesion between the current collector 5 and the active material of the anode 3. Like the cathode 2, the binder most used for the anode 3 is polyvinylidene fluoride (PVDF).

[0026] The anode and the cathode made of lithium insertion material can be deposited continuously using a standard technique in the form of an active layer on a metal sheet or foil constituting a current collector.

[0027] The current collector 4 connected to the positive electrode is generally made of aluminum.

[0028] The current collector 5 connected to the negative electrode is generally made of copper, nickel-plated copper or aluminum. More specifically, aluminum is used for the current collectors common to positive and negative electrodes of titanate Li4 Ti5O12. Copper is rather used for the negative electrodes of graphite (Cgr), silicon (Si) or silicon composite (Si-C).

[0029] A lithium-ion battery or accumulator can obviously comprise a plurality of electrochemical cells which are stacked on top of each other.

[0030] Traditionally, a Li-ion battery or accumulator uses a pair of materials at the anode and cathode allowing it to operate at a high voltage level, typically 1.5 and 4.2 Volts.

[0031] Depending on the type of application and / or the production method targeted, the aim is to produce either a thin and flexible lithium-ion accumulator or a rigid accumulator: the packaging is then either flexible or rigid, and in the latter case constitutes, in a way, a case.

[0032] Flexible packaging commonly called “pouch” is usually manufactured from a multi-layer composite material, consisting of a stack of aluminum layers covered by one or more polymer films laminated by bonding.

[0033] Rigid packaging (battery cases) is usually made from a metallic material, typically an aluminum alloy or stainless steel or a rigid polymer such as acrylonitrile butadiene styrene (ABS).

[0034] The geometry of rigid Li-ion battery packaging cases can be cylindrical, since most electrochemical cells of batteries are wound by winding in a cylindrical geometry around a mandrel. cylindrical. Prismatic shapes of cases are also made by flattened winding.

[0035] One of the types of rigid cylindrical shaped case, usually manufactured for a high capacity Li-ion accumulator, is illustrated in [Fig.3].

[0036] A rigid prismatic shaped case is also shown in [Fig.4].

[0037] The housing 6 comprises a cylindrical lateral envelope 7, a base 8 with a end, a cover 9 at the other end, the bottom 8 and the cover 9 being assembled to the casing 7. The cover 9 is generally crimped at a crimping groove. It can also be welded. The cover 9 supports the current output poles or terminals 4,5. One of the output terminals (poles), for example the negative terminal 5 is welded to the cover 9 while the other output terminal, for example the positive terminal 4, passes through the cover 9 with the interposition of a seal not shown which electrically insulates the positive terminal 4 from the cover.

[0038] Another possible configuration is that one of the output terminals (poles), for example the positive terminal 4 is connected to the electrochemical beam F of the accumulator A by the tab forming a collector 40 and projects and passes through the cover 9 with the interposition of a seal not shown which electrically insulates the positive terminal 4 from the cover. The other output terminal, for example the negative terminal 5, is constituted by the bottom and therefore the lateral envelope of the housing 6 which is electrically connected.

[0039] This configuration illustrated in [Fig.5], with the electrochemical beam wound around a mandrel M, is for example that which is typically encountered in existing accumulators of 18650, 21700 or 4680 format.

[0040] For each of the three types of accumulator geometry, the latter can be assembled and connected together to form accumulator batteries (also called batteries), in order to increase the energy stored in electrochemical form.

[0041] An assembly of several accumulators is generally called a battery module or module. And by assembling several modules, we obtain a battery pack, also called a pack.

[0042] A battery pack is thus made up of a variable number of accumulators, which can reach several thousand, which are electrically connected in series and / or in parallel with each other and generally by connection bars, usually called busbars.

[0043] Reference may be made to publication [4] for the constitution of modules and battery packs.

[0044] In all accumulators assembled or not in the form of modules and battery packs, the majority of the materials of interest for recycling are located in the electrochemical bundle of the accumulators.

[0045] Several processes are possible to release these materials of interest. The most used processes currently are thermal treatments, in particular by pyrolysis, and mechanical, in particular by grinding. These processes are followed by other processes allowing the recycling of the materials of interest.

[0046] Generally speaking, to date, a complete recycling process for a Li-ion accumulator comprises the following successive steps:

[0047] - an electric discharge then a complete disassembly of a module or pack battery in sub-elements;

[0048] - an opening of the accumulators, that is to say the physical rupture of its packaging flexible or rigid (casing), by crushing in an inert environment to avoid any explosion or fire;

[0049] - a physical separation of the different accumulator components, in particular packaging materials, generally aluminum, separators (PVDF), current collectors (aluminum, copper), active electrode insertion materials and liquid electrolyte;

[0050] - the recovery of transition metals contained in each accumulator.

[0051] Some of these steps and their associated drawbacks will now be described in more detail.

[0052] Opening a Li-ion battery:

[0053] On an industrial scale, this opening step generally consists of carrying out grinding to recover a ground material without loss of recoverable materials. The problems linked to this step are mainly technological and safety-related. Indeed, as mentioned above, before grinding, the batteries must be electrically discharged, in order to avoid or reduce the risks of fire or explosion. Grinding is generally carried out in an inert atmosphere (Ar, N2 or CO2).

[0054] Nitrogen (N2) can be combined with a shear grinding system with a high-speed chevron rotor. The nitrogen flow introduced at the grinder allows the heat produced during grinding to be dissipated quickly [5]. This technique makes it possible to consider grinding charged batteries without the risk of explosion or fire.

[0055] The use of CO2 allows the stabilization of the material by forming a passivating layer based on lithium carbonates on the surface of the lithium.

[0056] Other techniques can be mentioned such as that used in [6] which consists of carrying out the grinding under a significant flow of water in order to cool the medium and avoid any thermal runaway. Water has the advantage of leaching many lithium-bearing species soluble in an aqueous medium.

[0057] This solution can then be treated to recover the lithium by evaporation [7]. Electrolyte recycling

[0058] The electrolyte is a flammable and toxic organic liquid with a wide window of electrochemical stability and high ionic conductivity. It is therefore interesting, from an energy point of view, to recover the electrolyte during the battery opening step. The remaining volume, mobilized in the materials of an accumulator, can be recovered a posteriori.

[0059] The electrolyte is generally not recycled in industrial processes but incinerated.

[0060] However, there is a method for recycling the electrolyte on an industrial scale under the trade name Duesenfeld®, which implements a step of evaporation / condensation of the electrolyte, when opening the batteries by crushing: [8]. The temperature is fixed according to the evaporation temperature of the electrolyte close to 280 °C. This method does not allow the recovery of the conductive salt LiPF6, which is however the compound with the highest added value contained in the electrolyte.

[0061] The decomposition products of LiPF6 present a risk of corrosion and acute toxicity. Indeed, LiPF6 is rapidly decomposed into HF, POF3, HPO2F2, H2PO 3F and H3PO4 by hydrolysis, which results in the formation of a toxic atmosphere, very harmful to humans [9].

[0062] Physical separation between the active material of the electrodes and the current collectors

[0063] This separation step is crucial because it facilitates access to the active lithium ion insertion material, during the recovery of the metals of interest and limits the presence of impurities from the current collectors, generally aluminum for the cathode and copper for the anode. This separation is particularly important for the cathode with an aluminum collector because it contains the main metals of interest, namely lithium, nickel, manganese and cobalt for an NMC cathode. However, the active material adheres to the aluminum collector thanks to a polymer binder, generally PVDF, as specified above.

[0064] Thermal decomposition of PVDF [6] or its chemical dissolution [7] are the two main methods studied.

[0065] The use of heat treatment to enable the decomposition of the PVDF binder is the most common technique [6]. The temperatures used are between 160 and 600 °C [8,9]. However, this generates toxic gaseous effluents, such as hydrofluoric acid (HF).

[0066] The separation between the current collector and the active material of an electrode can also be achieved through the use of aprotic polar solvents allowing the dissolution of the binders contained in the electrodes such as N-methyl-2- pyrrolidone (NMP), dimethylacetamide (DMAC) [7], dimethyl sulfoxide (DMSO) [7], N,N-dimethylformamide (DMF) [7,10], triethyl phosphate

[11] or a deep eutectic solvent (DES)

[12] . This technique has the advantage of having a better separation efficiency than thermal processes with a better purity of the metals of interest. Furthermore, the solvents conventionally used are toxic. Recycling of PVDF binder

[0067] Due to its properties intermediate between those of gases and liquids, CO2 in the dense phase, i.e. beyond the critical pressure, also known as dense CO2, is a particularly interesting solvent for selective extraction and / or de-extraction.

[0068] The combination of CO2dense and an aprotic polar solvent, in judiciously chosen proportions, can allow the selective extraction of PVDF from lithium-ion battery electrodes with the following advantages.

[0069] Dense CO2 is inert and environmentally friendly. Its use therefore makes it possible to minimize the flow of organic solvents compared to conventional chemical dissolution.

[0070] Its low viscosity prevents adhesion to the surface of solid materials, thus eliminating any trace of residue after extraction.

[0071] Its high diffusivity allows for rapid extraction kinetics.

[0072] Finally, the extracted PVDF can be recovered without traces of organic solvents by simple depressurization and / or cooling of the CO2.

[0073] Among the aprotic polar solvents, N-methyl-2-pyrrolidone (NMP), dimethylacetamide (DMAC), dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), Cyrene, triethyl phosphate, lactones such as γ-valerolactone (GVL), γ-butyrolactone (GBL) may be mentioned.

[0074] From the above, it is understood that the methods implemented for the recycling of Li-ion accumulators or batteries comprise a succession of steps carried out after discharge and disassembly.

[0075] These processes involve different technologies of physical separation, indirect recycling by hydro or pyrometallurgical means, which must ultimately make it possible to recover the metals of interest contained in the material concentrated in the electrode insertion materials.

[0076] Physical separation involves a reduction in the size of the elements to be treated which can degrade the constituent materials of the accumulator or battery and limit their high added value recycling.

[0077] Furthermore, they generate a loss of recoverable material due to low selectivity.

[0078] In addition, these physical processes contaminate the materials generally introduced by a mixture of battery material. For example, fragments of the cathode tend to end up in the same flow as that of the electrolytes. Recovering lithium with a high degree of purity is difficult or even impossible without involving complex and expensive separation means.

[0079] Finally, these processes require energy consumption that is not compatible with a circular economy with low environmental impact.

[0080] There is therefore a need to improve, in a simple, robust and effective manner, the solutions for recycling metal-ion accumulators that are no longer in use and / or at the end of their life, in particular for all types of geometry (prismatic, cylindrical), with flexible or rigid packaging (case), and more particularly in order to overcome the known disadvantages of opening accumulators linked to the risks of fire and / or explosion, and / or recycling of the electrolyte and the organic binder.

[0081] The aim of the invention is to meet at least part of this need. Statement of the invention

[0082] To do this, the invention relates, in one of its aspects, to a method for recycling at least one metal-ion electrochemical accumulator (A) that is no longer in use and / or at the end of its life, the accumulator initially comprising an electrochemical bundle comprising at least one electrochemical cell consisting of an electrolyte constituent that can be impregnated in an electronic insulating and ion-conducting separator, between a cathode and an anode, a current collector connected to the cathode by at least one binder, a current collector connected to the anode by at least one binder and, a packaging arranged to contain the electrochemical bundle in a sealed manner while being crossed by a portion of the current collectors, forming the output terminals, the method comprising one and / or the other of the following steps:

[0083] i / opening the packaging of the accumulator, possibly electrically charged, and extraction of the electrolyte by circulation in the electrochemical beam through the open packaging of the accumulator, of at least one dense fluid, capable of inerting and cooling the accumulator,

[0084] ii / extraction of the binder(s) by circulation of CO2 under supercritical conditions, where appropriate mixed with at least one solvent.

[0085] Advantageously, the opening of the accumulator packaging and the extraction of the electrolyte are carried out simultaneously.

[0086] Advantageously, step ii / is carried out successively to step i / within the same device.

[0087] According to an advantageous application, the accumulator packaging is a case, the opening according to step i / comprises a step of longitudinal cutting of the case, preferably over its entire height.

[0088] Preferably, the opening according to step i / comprises both the longitudinal cutting of the housing and of the electrochemical bundle.

[0089] According to an alternative, the opening according to step i / comprises a step of crushing the accumulator.

[0090] According to an advantageous variant, the extraction according to step i / is carried out by circulation of liquid CO2 in dense phase.

[0091] Advantageously, the pressure and temperature of the CO2 according to step i / are respectively between 40 and 200 bar between 5 and 25°C.

[0092] Advantageously, the pressure and temperature of the CO2 according to steps i / and ii / are respectively between 60 and 250 bar and 40 and 90°C.

[0093] According to an advantageous configuration where the binder(s) is(are) organic, in particular a polyvinylidene fluoride (PVDF), step ii / is carried out in the presence of an aprotic or non-aprotic polar co-solvent.

[0094] According to an advantageous embodiment, the method comprises a step of recirculating the mixture of dense fluid and extracted electrolyte, for carrying out a subsequent step i / with another accumulator.

[0095] According to another advantageous embodiment, the method comprises a step of recirculating the CO2 mixture under supercritical conditions, where appropriate mixed with the co-solvent(s) for carrying out a subsequent step ii / with another accumulator.

[0096] The invention also relates to an apparatus for recycling at least one metal-ion electrochemical accumulator (A) that is no longer in use and / or at the end of its life, the accumulator initially comprising an electrochemical bundle comprising at least one electrochemical cell consisting of an electrolyte constituent that can be impregnated in an electronic insulating and ionic conducting separator, between a cathode and an anode, a current collector connected to the cathode by at least one binder, a current collector connected to the anode by at least one binder and, a packaging arranged to contain the electrochemical bundle in a sealed manner while being crossed by a portion of the current collectors forming the output terminals, comprising: - a first module including: • a body delimiting a chamber suitable for housing the accumulator, comprising:

[0097] at least one orifice for supplying a dense fluid, capable of inerting and cooling the accumulator, and

[0098] at least one orifice for discharging a mixture of at least the dense fluid and the electrolyte of the open accumulator; • at least one means for opening the accumulator, mounted in the chamber;

[0099] and / or - a second module comprising: • a body delimiting a chamber adapted to house the open accumulator, comprising:

[0100] at least one CO2 feed port under supercritical conditions, where appropriate mixed with at least one solvent, and

[0101] at least one orifice for discharging a mixture of at least the CO2 under supercritical conditions and the binder(s) of the open accumulator.

[0102] According to an advantageous configuration, the first module is fixed above the second module with their chambers connected so that once the accumulator is opened and its electrolyte extracted in the chamber of the first module, it is evacuated by gravity into the chamber of the second module.

[0103] The opening means may be a cutting disc, preferably electrically insulated, or a knife grinder.

[0104] According to an advantageous embodiment variant, the first module comprises a heat exchanger, arranged around at least one part of the body, in which a heat transfer fluid can circulate so as to evacuate the heat released by the opening of the accumulator and to maintain the dense fluid at a temperature allowing the extraction of the electrolyte.

[0105] According to another advantageous embodiment variant, the first module comprises a barrel rotatably mounted inside the chamber and the housings of which are each adapted to house and hold an accumulator before it is opened, each of the housings being adapted to allow the opening means of the accumulator housed within it to pass through.

[0106] Preferably, the second module comprises heating means, arranged around at least one part of the body to maintain the CO2 above the supercritical temperature allowing the extraction of the accumulator binder(s).

[0107] More preferably, the second module comprises a basket rotatably mounted inside the chamber and adapted to contain one or more open accumulators.

[0108] The invention also relates to a recycling installation comprising: - a recycling apparatus as described previously, - at least one fluid circuit for supplying dense fluid, comprising: • a dense fluid storage tank, • a feed pump connected upstream to the dense fluid storage tank and downstream to the feed port of the first module, - at least one fluid circuit for supplying CO2 under supercritical conditions comprising: • a CO2 storage tank, • a feed pump connected upstream to the CO2 storage tank and downstream to the feed port of the second module, - where applicable at least one solvent storage tank connected to the fluid circuit(s), upstream of the supply port of the first and / or second module.

[0109] Preferably, the reservoir of the dense fluid is that of CO2

[0110] According to an advantageous embodiment, the installation comprises at least one fluid circuit for recovering and separating the dense fluid and the accumulator electrolyte(s), the circuit comprising one or more cyclonic separators in series, connected upstream to the discharge orifice of the first module.

[0111] According to another advantageous embodiment, the installation comprises at least one fluid circuit for recovering and separating CO2 and the accumulator binder(s), the circuit comprising one or more cyclonic separators in series, connected upstream to the discharge orifice of the second module.

[0112] Thus, the invention essentially consists of a method for recycling a metal-ion accumulator that is no longer in use and / or at the end of its life, which implements two steps that can be carried out independently and which consist of:

[0113] - an opening of the packaging (flexible or case) of the accumulator, whether it is electrically charged or discharged,

[0114] - an extraction from the electrochemical beam, of the electrolyte by circulation of a dense fluid, under pressure, and

[0115] - an extraction of the binder, in particular PVDF, binding the insertion materials to the current collectors of the electrodes by circulation of CO2 under supercritical conditions.

[0116] By “supercritical conditions” is meant carbon dioxide pressure and temperature conditions respectively greater than 74 bar and 31°C.

[0117] The opening of the accumulator and the extraction of its electrolyte are preferably carried out concomitantly.

[0118] The step of extracting the organic binder, in particular PVDF, is advantageously carried out after the extraction of the electrolyte, preferably within the same device. These operations further reduce the recycling processing time.

[0119] The dense fluid under pressure used to extract the liquid electrolyte from the accumulators is advantageously CO2 in the liquid state. Any other dense fluid under pressure having inerting and refrigeration properties in the liquid state (Ar, N2, methanol, nitrous oxide, etc.) may be suitable. It is known that CO2 in the liquid state creates an oxygen-depleted atmosphere in a confined environment making any combustion impossible and has a density equivalent to that of a liquid, which gives it good apolar solvent power. CO2 in the liquid state can be transported by a high-pressure pump or a high-flow circulator provided that temperature and pressure conditions allow a liquid state to be maintained. For example, temperature and pressure conditions of 5°C and 60 bar, respectively, are sufficient to maintain the liquid state while giving the CO2 good solvent and refrigerant power.

[0120] The extraction of binders, in particular organic binders such as PVDFs, using CO2 under supercritical (SC) conditions is judicious because its density close to that of liquids and its low dielectric constant give it solvation properties that are particularly favorable towards apolar species. SC CO2 also has a low viscosity and a high diffusivity (similar to the gaseous state), thus allowing it a considerable capacity for penetration into porous media. These characteristics give SC CO2 the ability to diffuse into the very heart of porous materials (diffusion at the molecular scale) and to allow efficient solubilization / extraction, preferably by combining it with another suitable solvent. The properties of SC CO2 must thus make it possible, in the context of the invention, to significantly improve the solubilization / extraction kinetics of the organic binder(s) of metal-ion accumulators.Furthermore, the CO2 SC medium makes it possible to reduce the volume of solvents used and facilitate their recycling.

[0121] It is specified that prior to implementing the method, it is not necessary to electrically deactivate each accumulator concerned.

[0122] An accumulator recycled with the method according to the invention can therefore initially have a state of charge (SOC, Anglo-Saxon acronym for “State Of Charge”) of up to 100%.

[0123] The invention also relates to a recycling apparatus which has the following functions:

[0124] - mechanical opening by cutting, preferably using a grinder, or by grinding using a knife mill of a Li-ion accumulator which can still be electrically charged, this opening being carried out under circulation of CO2 at the liquid state, where appropriate in the presence of another solvent (co-solvent), and at a flow rate sufficient to cool the cut parts or the ground material, in order to limit exothermic reactions during possible contact between the cathode and the anode;

[0125] - implementation of a zone ensuring the dynamic confinement of the cutting or the grinding the accumulator around the area in which the opening is made;

[0126] - control of the excess thermal power released by the opening of the accumulator to an external circuit which ensures that the temperature in the opening zone is maintained and limits the temperature to which the device is exposed. Temperature control and limitation are advantageously ensured by an exchanger integrated into the opening module of the device in the form of a double wall protected from attack. The materials constituting this integrated exchanger can be defined to optimize heat transfer;

[0127] - continuous cooling of the cutting or the ground materials. This function of Cooling is preferably provided by a so-called cold exchanger, external to the device, which maintains the temperature of the circulating dense fluid, preferably CO2, in a range of -10 to +10°C in the opening zone of the accumulator. This cold exchanger is installed downstream of the high-pressure pump circulating the dense fluid and located very close upstream of the exchanger integrated in the opening module of the device. The walls of this exchanger withstand a mechanical compressive stress imposed by the operating pressure, typically 60 bar. The constituent materials of this cold exchanger can be defined to optimize heat transfer.

[0128] - management of cutting products or shredded material present in the opening zone. These products are immediately evacuated to an extraction module of the device, the electrode binder(s), in particular PVDF and the metals of interest being treated within this module by supercritical CO2, if necessary in the presence of a co-solvent.

[0129] - easy maintenance of the internal equipment of the device by the implementation of flanges that can allow quick and easy interchangeability of the interchangeable opening module according to the type of opening and / or geometry of the desired accumulators. The device is kept cold in the opening zone, typically at around 5°C. A temperature above the critical point of CO2, typically above 31°C, is maintained in the extraction zone of the accumulator binder(s). The operating temperature of this extraction zone allows the use of simple and robust sealing means, for example Viton™ fluoroelastomer seals.

[0130] Ultimately, the invention provides numerous advantages over the methods according to the state of the art, among which we can cite: - reduction of the processing time for recycling a metal-ion accumulator by eliminating the discharge phase. The invention makes it possible to significantly reduce the processing time for the recycling operation of metal-ion batteries, in particular Li-ion, by eliminating a prior electrical discharge step that is essential in the state of the art, which is time-consuming and energy-consuming, and by simultaneously opening an accumulator and extracting its electrolyte; - reduction of risks associated (fire, explosion) with a short circuit between the cathode and the anode of an accumulator when it is opened; - extraction of electrolyte from an accumulator, in an uncontaminated state; - direct preparation for subsequent recycling of the metals of interest (lithium, nickel, manganese, cobalt) from the electrodes due to the extraction / solubilization of the organic binder(s), such as PVDF, from their active material.

[0131] The invention also relates to an electrochemical bundle of a metal-ion electrochemical accumulator recycled according to the method as described previously.

[0132] When the extracted electrochemical beam is that of a Li-ion accumulator: - the negative electrode(s) material is chosen from the group comprising graphite, lithium, silicon or titanate oxide Li4TiO5Oi2; - the positive electrode(s) material is chosen from lithium cation insertion materials which are generally composite, such as lithium iron phosphate LiFePO4, lithium cobalt oxide LiCoO2, lithium manganese oxide, possibly substituted, LiMn2O4 or transition metal oxide, such as lamellar materials for example, a material based on LiNixMnyCozO2 with x+y+z = 1, such as LiNi0.33Mno.33Co0.3302 or LiNio.8Mn0.iCoo.i02, or a material based on nickel cobalt aluminum oxide type LiNixCoyAlzO2 with x+y+z = 1, such as LiNi0.8Co0.15Al0.05O3.

[0133] Other advantages and characteristics of the invention will become more apparent upon reading the detailed description of examples of implementation of the invention given by way of illustration and not limitation with reference to the following figures. Brief description of the drawings

[0134] [Fig.l] [Fig.l] is an exploded perspective schematic view showing the various elements of a lithium-ion accumulator.

[0135] [Fig.2] [Fig.2] is a front view showing a lithium-ion battery with its flexible packaging according to the state of the art.

[0136] [Fig.3] [Fig.3] is a perspective view of a lithium-ion accumulator according to state of the art with its rigid packaging consisting of a cylindrical shaped box.

[0137] [Fig.4] [Fig.4] is a perspective view of a state-of-the-art lithium-ion accumulator with its rigid packaging consisting of a prismatic-shaped case.

[0138] [Fig.5] [Fig.5] is a perspective view of a state-of-the-art lithium-ion battery configuration with its rigid packaging consisting of a cylindrical-shaped case with a projecting output terminal at one of its longitudinal ends, the other output terminal being formed by the bottom of the case.

[0139] [Fig.6], [Fig.6A] Figures 6 and 6A are views respectively in longitudinal section and in cross section of an apparatus for recycling lithium-ion accumulators of cylindrical geometry, according to the invention.

[0140] [Fig.7] [Fig.7] is a perspective view of a portion of the upper module of the apparatus of Figures 6 and 6A, in which the accumulator cutout and the evacuation of the cutout portions is carried out.

[0141] [Fig.8] [Fig.8] is a block diagram of a lithium-ion battery recycling installation incorporating a device according to Figures 6 and 6A. Detailed description

[0142] Figures 1 to 5 relate to different examples of Li-ion accumulators, flexible packaging and accumulator cases as well as a battery pack according to the state of the art.

[0143] These figures 1 to 5 have already been commented on in the preamble and are therefore not commented on further below.

[0144] For the sake of clarity, the same references designating the same elements according to the state of the art and according to the invention are used for all figures 1 to 8.

[0145] Also for the sake of clarity, only a few accumulators A1 to A4 are shown in a recycling apparatus 10 which implements the method according to the invention.

[0146] Throughout the present application, the terms "lower", "upper", "bottom", "top", "below" and "above" are to be understood by reference to a recycling apparatus arranged in its operating configuration, vertically, with the accumulator opening module above the organic binder extraction module (PVDF).

[0147] In the illustrated examples, the accumulators A1-A4... illustrated have cylindrical format cases 6, typically 18650 or 20700 or 21700 or 4680 format.

[0148] The accumulators A1-A4... out of use and / or at the end of their life which are recycled according to the invention, may have been previously assembled within the same battery module or battery pack are arranged parallel to each other.

[0149] When they are introduced into the recycling apparatus, they are individualized, that is to say that each Al.. .A4 Li-ion accumulator is introduced intact and as shown in [Fig.5], it initially comprises an electrochemical bundle (F) comprising at least one electrochemical cell consisting of a liquid electrolyte 1 which can be impregnated in an electronic insulating and ionic conducting separator, between a cathode 2 and an anode 3, a current collector 4 connected to the cathode 2 by a PVDF binder, a current collector 5 connected to the anode 3 by a PVDF binder and, a housing 6 arranged to contain the electrochemical bundle with sealing while being crossed by a part of the current collectors 4, 5 forming the output terminals.

[0150] As illustrated in Figures 6 and 6A, a recycling apparatus 10 for Li-ion Al-A4 accumulators comprises two separate modules 20, 30, assembled together one being above the other, with their central axis X merged and their interior chambers which communicate as detailed below.

[0151] Module 20 is the module in which the actual step of opening the accumulators A1-A4 simultaneously with the step of extracting their electrolyte takes place.

[0152] The module 20 firstly comprises a body 21 internally delimiting a chamber 22.

[0153] The body 21 is essentially constituted by a cylinder 210 at the ends of which two flanges 211, 212 are removably assembled. The cylinder 210 and the flanges 211, 212 are preferably heat-insulated on their external surface and made of a material and with a geometry enabling them to contain a fluid under pressure and at high temperature.

[0154] The body 21 houses a barrel carriage 23 in which is inserted a rotating barrel 230 containing a number of accumulators Al, .. .An to be cut, each arranged vertically in a housing of the barrel 230. The number of accumulators that can be housed in the barrel 230 can be large, for example 10 as illustrated. The barrel 230 can be sized so as to obtain a vertical stack of accumulators, for example with two accumulators one on top of the other in the same housing. The number of accumulators to be cut depends on the height of the barrel and therefore on the device to be considered. Generally speaking, the number is advantageously adjusted according to the space constraints of the recycling device 10 and taking into account the accumulator formats.

[0155] Two sealed bushings 24, 25 are mounted in the upper flange.

[0156] One of these sealed crossings 24 is equipped with a manual or motorized magnetic drive 240 coupled with a vertical drive screw 241 to carry out the raising and lowering of the barrel carriage 240 within the chamber 22.

[0157] The other of these sealed crossings 25 is equipped with a manual or motorized control 250 coupled with a magnetic drive 251 to carry out a sequenced rotation of the barrel 230 in order to bring each of the plurality of accumulators therein into a cutting position.

[0158] With regard to this cutting position, a cutting system in the form of a grinder equipped with a cutting disc, preferably made of diamond 26, electrically insulated is arranged in the chamber 22. The diamond disc 26 can be rotated by an external motor 27 coupled with a magnetic drive 270. This disc 26 makes it possible to cut a cylindrical accumulator Al, .. .An according to its longitudinal dimension, preferably over the entire height of the accumulator casing, so that all of its components are released, that is to say without the initial sealed barrier constituted by the casing and therefore so that they are accessible to a flow of liquid CO2.

[0159] The diamond disc 26 is advantageously sized to make fine cuts, like a microtome.

[0160] The lower flange 212 of the body is pierced with an orifice 213 for injecting CO2 in the liquid state inside the chamber 22, which, when circulating at the required flow rate, makes it possible to cool the cut parts and efficiently extract the electrolyte from each previously cut Al, .. .An accumulator.

[0161] The upper flange 211 of the body is pierced with an orifice 214 for discharging the liquid CO2 / electrolyte mixture.

[0162] The module 20 may further comprise a heat exchanger 28 in the form of a double wall 29 with the wall of the cylinder 210. In this exchanger 28, a heat transfer fluid circulates, supplied and treated by an external circuit connected to the fluid lines 280, 281 respectively of inlet and outlet. This heat exchanger 28 has the function of evacuating the energy generated during the cutting of an accumulator and of maintaining the CO2 in the liquid state in the opening zone Z. This exchanger 28 is therefore protected from the attacks of the opening of the accumulator Al, ... An and is not subjected to mechanical stress in compression. Depending on the available space and the required heat exchanges, it is possible to add welded fins or baffles to the intrados over all or part of the circumference of the wall 29 of the exchanger 28.

[0163] Module 30 is the module in which the step of extracting the PVDF binder from the accumulators A2, A3, A4, etc. takes place.

[0164] The module 30 firstly comprises a body 31 internally delimiting a chamber 32 and the upper part of which is the lower flange 212 of the body 21 of the module 20. The body 31 is made of a material and with a geometry enabling it to contain a fluid under pressure and temperature.

[0165] A perforated metal basket 33 is housed in the chamber 32. This basket 33 can be rotated by an external motor 34 via a magnetic drive not shown. This perforated metal basket 33 makes it possible to recover the accumulator parts A2, A3, A4 cut out from the module 20 above.

[0166] The perforation mesh of the basket 33 is suitable for solid leaching / dissolution operations. The meshes can thus be in the form of round holes, for example 1 mm, spaced 2 mm apart.

[0167] The upper part 212 of the body 31 is pierced with an orifice 310 for injecting CO2 in the supercritical state with, if necessary, another solvent (co-solvent), which when it circulates at the required flow rate, makes it possible to extract the PVDF and separate the active material of the accumulator electrodes from their corresponding current collector.

[0168] The upper part 212 of the body 31 is pierced with an orifice 311 for discharging the CO2 / PVDF / co-solvent mixture.

[0169] The body 31 is advantageously equipped with heating collars 35 arranged on the external wall of the body.

[0170] The recycling apparatus 10 can be integrated into a recycling installation 100 as shown in [Fig.7].

[0171] The installation 100 comprises tanks 101, 102 for storing CO2 and deco-solvent respectively.

[0172] The CO2 is supplied from the tank 101 by a high pressure pump 103 passing through a regulator 104.

[0173] A hot exchanger 105 makes it possible to heat the CO2 under pressure to bring it into supercritical conditions.

[0174] A cold exchanger 106 makes it possible to cool the CO2 which is in the liquid state at the outlet.

[0175] The co-solvent is supplied from the reservoir 102 by a high pressure pump 107.

[0176] The fluid lines make it possible to mix the CO2 in the liquid state and the co-solvent before their injection on the one hand into the orifice 213 of the module 20 and on the other hand into the orifice 310 of the module 30.

[0177] The outlet of the discharge orifice 214 is connected downstream to cyclonic separators S1, S2, a control valve VC being inserted upstream of each cyclonic separator to manage the fluid before its arrival in the corresponding separator.

[0178] The outlet of the discharge orifice 311 is connected downstream to cyclonic separators S3, S4, a control valve VC being inserted upstream of each cyclonic separator to manage the fluid before its arrival in the corresponding separator.

[0179] Various V valves are installed on the fluid lines of the installation to manage, or even interrupt, the flow of fluids circulating within them.

[0180] An advantageous variant consists of providing a fluid line with a safety means for evacuating liquid and / or gaseous effluents in the event of unwanted overpressure relative to the operating pressure. As shown in [Fig.7], the safety means may consist of a rupture disc 110 fluidly connected to the module 20.

[0181] Finally, different PT pressure sensors, TT thermocouples and FT flow meters to manage respectively the pressures, temperatures and flow rates of the fluids in different places of the installation for its optimal operation.

[0182] The operation of the recycling apparatus 10 and the related installation 100 will now be explained.

[0183] Before describing the actual steps of the method implemented by the apparatus 10 and the associated installation 100, the following conditions are established during the method:

[0184] - pressurization / operating temperature of each of the modules 20 and 30,

[0185] - continuous supply (stable flow) of liquid and supercritical CO2, and depending on needs, injection through orifices 213 and / or 310,

[0186] - continuous supply (stable flow) of co-solvent mixed with liquid CO2 or supercritical, and depending on the needs, injection through the orifices 213 and / or 310,

[0187] - thermal equilibrium resulting from the release of heat from the opening of a accumulator, heat exchanges with the heat exchanger 27, heat exchanges with the heating collars 35 and temperatures of the supply fluids (liquid / supercritical CO2).

[0188] Step i / : _ opening of accumulator _ and extraction of the electrolyte by circulation of CO 2 in liquid state:

[0189] The pressure / temperature conditions of CO2 in the liquid state allow both the opening of an accumulator, even electrically charged, in good safety conditions and the extraction of the electrolyte.

[0190] The circulation of liquid CO2 from the reservoir 101 at a required flow rate thus allows both the cooling of the parts of the cut accumulator and the extraction of the electrolyte which is released during cutting.

[0191] In this opening step, the orifices 310, 311 of the module 30 are closed, the heating collars 35 are not in operation and the basket 33 is not rotating.

[0192] The sub-steps are as follows:

[0193] il / opening of the upper flange 211 of the module 20 and release of the body 21 to have access to the barrel 230,

[0194] i2 / individual insertion and maintenance of the accumulators Al, .. .An in the housings of the barrel 230 which has been brought into its upper position by the barrel carriage 23 via the vertical drive screw 241,

[0195] i3 / once loading is complete, closing of the flange 211,

[0196] i4 / putting the heat exchanger 28 into operation, so as to be able to evacuate the heat generated when cutting an Al accumulator and maintaining the CO2 in the liquid state in the opening zone Z,

[0197] i5 / injection of CO2 in liquid state through orifice 213 then circulation in the chamber 22 and waiting for thermal equilibrium. This circulation of liquid CO2 allows the cooling of the entire chamber 22 and particularly of the opening zone Z. It also allows the medium to be depleted of oxygen. Under these conditions, the CO2 pressure and temperature setpoints are lower than supercritical conditions (P<74 bar and T<31°C). Ideally, the setpoint pressure is between 40 and 200 bar and the temperature between 5 and 25°C. Once the operating conditions are reached, a sufficiently long hold to reach thermal equilibrium is carried out,

[0198] i6 / starting up the diamond cutting disc 26 and lowering the carriage barrel 23 in line with the disc 26 in the opening zone Z cooled by the circulation of CO2 in the liquid state. A thin accumulator cut makes it possible both to reduce the risks of short circuit between the cathode and the anode and also to maximize the contact surface between the flow of CO2 in the liquid state circulating in the opening zone Z of the battery and the electrolyte.

[0199] i7 / cutting of the accumulator Al

[0200] i8 / raising of the barrel carriage 23, evacuation of the cut parts A2, A3, A4., by gravity fall into the basket 33 within the chamber 32 of the module 30, and sequenced rotation of the barrel 230 by the manual or motorized control 250 for cutting the next accumulator.

[0201] As shown in [Fig.7], the barrel 23 comprises a housing 231 which opens downwards and therefore towards the module 30. This housing 231 is dedicated to the evacuation of each cut-out accumulator.

[0202] Thus, once the accumulator has been cut, the rotation of the barrel 230 carried out by means of the manual or motorized control 250, brings each of the accumulators Al, ... An cut into the housing 231. When the barrel carriage 23 rises, a fixed axis 232 is inserted into the housing 231 and therefore pushes the cut pieces towards the module 30.

[0203] Sub-steps i6 / to i8 / are repeated until the barrel 230 is empty, that is to say it no longer contains any accumulators to be cut.

[0204] The physical separation of the electrolyte is carried out, downstream of the discharge orifice 214, using the cyclonic separators S1, S2, the number of which can advantageously be up to three.

[0205] Step ii / : Extraction of the organic binder (PVDF) in the presence of CO2

[0206] The pressure / temperature conditions of the CO2 in the possible presence of the cosolvent allow the extraction of the PVDF binder. Adjusting the CO2 flow rate, the cosolvent flow rate, the rotation speed of the basket 33, the operating pressure and the operating temperature allow the extraction of the PVDF binder in the presence of CO2 to be optimized.

[0207] The ports 213 and 214 of the module 20 are first closed, and the heat exchanger 28 is no longer in operation.

[0208] The sub-steps are as follows:

[0209] iil / putting into operation the heating collars 35 so as to provide the heat necessary to maintain the CO2 at a temperature above the critical temperature of the CO2 (31°C) in the chamber 32,

[0210] ii2 / continuous rotation of the basket 33 at a speed imposed by the external motor 34 via a magnetic drive. The mixture consisting of divided pieces of accumulators or ground material depending on the type of opening used, which is contained in the basket 33 is thus kept agitated while best respecting the conditions for extracting the PVDF (pressure, temperature, supercritical CO2 flow rate). The mesh and the rotation speed of the basket 33 allow good percolation of the CO2 through the different cut-out parts of the accumulators.

[0211] ii3 / injection of CO2 in the supercritical state through the orifice 310 for its circulation within the chamber 32, in the presence of the co-solvent or not. The circulation of CO2 in the supercritical state makes it possible to extract the PVDF binder contained in the different cut parts of accumulators. Under these conditions, the pressure and temperature setpoints of the CO2 are respectively between 60 and 250 bar and 40 and 90 °C.

[0212] The physical separation of the PVDF is carried out, downstream of the discharge orifice 311, using the cyclonic separators S3, S4, the number of which can advantageously be up to three.

[0213] An advantageous variant of the installation 100 may consist of adding a loop for partially reintroducing the liquid CO2 / electrolyte mixture, evacuated through the orifice 214 to supply the chamber 22 in return. This loop may comprise a recirculation pump 108 and a heat exchanger 109 downstream to regulate the temperature as required.

[0214] A known limitation of continuous CO2 solubilization processes is that the solubilization of the compounds of interest (CO2-phile) can be carried out slowly with significant dilution of the material to be recovered.

[0215] Thus, the recycling of the flow implemented by a recirculation loop makes it possible to increase the concentration of the compounds of interest in the liquid CO2 and to reduce the flow of effluent produced in relation to the quantity of material to be treated.

[0216] Similarly, although not shown, it is possible to envisage the partial reintroduction of the CO2 / PVDF / co-solvent mixture from module 30 in order to increase the efficiency of extraction of the PVDF.

[0217] The invention is not limited to the examples which have just been described; it is possible in particular to combine characteristics of the examples illustrated within non-illustrated variants.

[0218] Other variants and improvements may be envisaged without departing from the scope of the invention.

[0219] The invention applies to any metal-ion accumulator, whatever its format and / or its packaging (flexible or case), with liquid or gel electrolyte, insofar as a circulation of dense fluid, in particular liquid CO2 in dense phase, on the electrochemical beam is suitable for solubilizing said electrolyte.

[0220] If in the examples illustrated, the steps of the method are carried out for accumulators with a cylindrical-shaped casing 6, the entire method can be implemented on accumulators with a prismatic-shaped casing, or with a flexible envelope ("pouch"), the cutting step i / preferably taking place on the side of the envelope from which the tabs forming the output terminals emerge.

[0221] If the example illustrated concerns accumulators with PVDF binder, the invention can be extended to other organic binders because an adjustment of the operating parameters or a suitable selection of a new co-solvent must allow the transposition of the step of extraction of the PVDF binder in CO2 medium to other organic binders.

[0222] Mechanical opening can be carried out by cutting or by grinding. In the example illustrated, the cutting means is a diamond disc. In the case of grinding, a knife mill can be considered to shear the accumulators at high speed in order to reduce friction between the cathode and the electrode and therefore reduce the risk of short circuit. Generally speaking, any opening means allowing access of the accumulator components to a dense fluid can be considered. List of cited references#:

[0223] [1]: Arno Kwade, Jan Diekmann, “Recycling of Lithium Ion Batteries: The LithoRec Way”.

[0224] https: / / doi.org / 10.1007 / 978-3-319-70572-9

[0225] [2]: WN Smith, S. Swoffer, “Recovery of lithium-ion batteries”, 2013.

[0226] [3]: TR Jow, X. Kang, O. Boroding, U. Makoto, "'Electrolytes for Lithium and Lithium-Ion Batteries”, Springer, 2014.

[0227] [4]: Harper, G., Sommerville, R., Kendrick, E., Driscoll, L., Slater, P., Stolkin, R.,... & Anderson, P, "Recycling lithium-ion batteries from electric vehicles”. Nature, (2019). 575 (7781), pages 75-86.

[0228] http: / / doi.org / 10.1038 / s41586-019-1682-5

[0229] [5]: S. Nowak, M. Winter, "The rôle ofsub- and supercritical CO2 as “processing solvent” for the recycling and sample préparation of lithium-ion battery electrolytes,” Molécules. 22 (2017). https: / / doi.org / 10.3390 / molecules22030403.

[0230] [6]: J. Neumann, M. Petranikova, M. Meeus, J.D. Gamarra, R. Younesi, M. Winter, S. Nowak, "Recycling of Lithium-Ion Batteries—Current State of the Art, Circular Economy, and Next Génération Recycling,” Advanced Energy Materials. 12 (2022) 2102917. https: / / doi.org / 10.1002 / aenm.202102917.

[0231] [7] : L.-P. He, S.-Y. Sun, X.-F. Song, J.-G. Yu, "Recovery of cathode materials and Al from spent lithium-ion batteries by ultrasonic cleaning”, Waste Management. 46 (2015) 523-528. https: / / doi.Org / 10.1016 / j.wasman.2015.08.035.

[0232] [8]: L. Schwich, T. Schubert, B. Friedrich, "Early-stage recovery of lithium from tailored thermal conditioned black mass part i: Mobilizing lithium via supercritical co2-carbonation, Metals”. 11 (2021) 1-30. https: / / doi.org / 10.3390 / metll020177.

[0233] [9]: J. Xiao, T. Zhou, R. Shen, Z. Xu, ''Migration and transformation oftoxic electrolytes during mechanical treatment of spent Lithium-ion batteries” ACS Sustainable Chem. Eng. 11(2023) 4707-4715. https: / / doi.org / 10.1021 / acssuscheme ng.2c07116

[0234]

[10] : C. Hanisch, T. Loellhoeffel, J. Diekmann, K.J. Markley, W. Haselrieder, A. Kwade, "Recycling of lithium-ion batteries: A novel method to separate coating andfoil of électrodes”, Journal of Cleaner Production. 108 (2015) 301-311. https: / / doi.org / 10.1016 / j.jclepro.2015.08.026.

[0235]

[11] : D. Song, X. Wang, E. Zhou, P. Hou, F. Guo, L. Zhang,” Recovery and heat treatment of the LiNi 0.33 Mn 0.33 Co 0.33 O 2 cathode scrap material for lithium ion battery”, Journal of Power Sources. 232 (2013) 348-352. https: / / doi.org / 10.1016 / j.jpowsour.2012.10.072.

[0236]

[12] :Y. Bai, R. Essehli, C.J. Jafta, K.M. Livingston, I. Belharouak, "Recovery of Cathode Materials and Aluminum Foil Using a Green Solvent”, ACS Sustainable Chemistry and Engineering. 9 (2021) 6048-6055. https: / / doi.org / 10.1021 / acssuschemeng. lc01293.

Claims

Claims

1. Method for recycling at least one metal-ion electrochemical accumulator (A) that is no longer in use and / or at the end of its life, the accumulator initially comprising an electrochemical bundle (F) comprising at least one electrochemical cell consisting of an electrolyte constituent (1) that can be impregnated in an electronic insulating and ionic conducting separator, between a cathode (2) and an anode (3), a current collector (4) connected to the cathode (2) by at least one binder, a current collector (5) connected to the anode (3) by at least one binder and, a packaging (6) arranged to contain the electrochemical bundle in a sealed manner while being crossed by a portion of the current collectors (4, 5) forming the output terminals, the method comprising one and / or the other of the following steps: i / opening the packaging of the accumulator, possibly electrically charged,and extraction of the electrolyte by circulation in the electrochemical beam through the open packaging of the accumulator, of at least one dense fluid, capable of inerting and cooling the accumulator, ii / extraction of the binder(s) by circulation of CO2 in supercritical conditions, where appropriate mixed with at least one solvent.,

2. Recycling method according to claim 1, the opening of the accumulator packaging and the extraction of the electrolyte being carried out simultaneously.

3. Recycling method according to claim 1, step ii / being carried out successively to step i / within the same device.

4. Recycling method according to one of the preceding claims, the accumulator packaging being a case, the opening according to step i / comprising a step of longitudinal cutting of the case, preferably over its entire height.

5. Recycling method according to claim 4, the opening according to step i / comprising both the longitudinal cutting of the housing and the electrochemical bundle.

6. Recycling method according to one of claims 1 to 3, the opening according to step i / comprising a step of crushing the accumulator.

7. Recycling method according to one of the preceding claims, the extraction according to step i / being carried out by circulation of liquid CO2 in dense phase.

8. Recycling method according to one of the preceding claims, the pressure and temperature of the CO2 according to step i / being respectively between 40 and 200 bar between 5 and 25°C.

9. Recycling method according to one of the preceding claims, the pressure and temperature of the CO2 according to step ii / being respectively between 60 and 250 bar and 40 and 90°C.

10. Recycling method according to one of the preceding claims, the binder(s) being organic, in particular a polyvinylidene fluoride (PVDF), step ii / being carried out in the presence of an aprotic or non-aprotic polar cosolvent.

11. Recycling method according to one of the preceding claims, comprising a step of recirculating the mixture of dense fluid and extracted electrolyte, for carrying out a subsequent step i / with another accumulator.

12. Recycling method according to one of the preceding claims, comprising a step of recirculating the CO2 mixture under supercritical conditions, where appropriate mixed with the co-solvent(s) for carrying out a subsequent step ii / with another accumulator.

13. Apparatus for recycling at least one metal-ion electrochemical accumulator (A) that is out of use and / or at the end of its life, the accumulator initially comprising an electrochemical bundle (F) comprising at least one electrochemical cell consisting of an electrolyte constituent (1) that can be impregnated in an electronic insulating and ionic conducting separator, between a cathode (2) and an anode (3), a current collector (4) connected to the cathode (2) by at least one binder, a current collector (5) connected to the anode (3) by at least one binder and, a packaging (6) arranged to contain the electrochemical bundle with sealing while being crossed by a part of the current collectors (4, 5) forming the output terminals, comprising: - a first module comprising: • a body delimiting a chamber adapted to house the accumulator, comprising: at least one orifice for supplying a dense fluid, capable of inerting and cooling the accumulator, and at least one orifice for discharging a mixture of at least the dense fluid and the electrolyte of the open accumulator; • at least one means for opening the accumulator, mounted in the chamber; and / or - a second module comprising: • a body delimiting a chamber adapted to house the open accumulator, comprising: at least one orifice for supplying CO2 under supercritical conditions, where appropriate mixed with at least one solvent, and at least one orifice for discharging a mixture of at least the CO2 under supercritical conditions and the binder(s) of the open accumulator.

14. A recycling apparatus according to claim 13, the first module being fixed above the second module with their chambers connected so that once the accumulator is opened and its electrolyte extracted in the chamber of the first module, it is evacuated by gravity into the chamber of the second module.

15. A recycling apparatus according to claim 13 or 14, the opening means being a cutting disc, preferably electrically insulated, or a knife mill.

16. Recycling apparatus according to one of claims 13 to 15, the first module comprising a heat exchanger, arranged around at least one part of the body, in which a heat transfer fluid can circulate so as to evacuate the heat released by the opening of the accumulator and to maintain the dense fluid at a temperature allowing the extraction of the electrolyte.

17. Recycling apparatus according to one of claims 13 to 16, the first module comprising a barrel rotatably mounted inside the chamber and the housings of which are each adapted to house and hold an accumulator before it is opened, each of the housings being adapted to allow the opening means of the accumulator housed therein to pass through.

18. Recycling apparatus according to one of claims 13 to 17, the second module comprising heating means, arranged around at least one part of the body to maintain the CO2 above the supercritical temperature allowing the extraction of the accumulator binder(s).

19. A recycling apparatus according to any one of claims 13 to 18, the second module comprising a basket rotatably mounted inside the chamber and adapted to contain one or more open accumulators.

20. Recycling installation comprising: - a recycling apparatus according to one of claims 13 to 19, - at least one fluid circuit for supplying dense fluid, comprising: • a dense fluid storage tank, • a supply pump connected upstream to the dense fluid storage tank and downstream to the supply orifice of the first module, - at least one fluid circuit for supplying CO2 under supercritical conditions comprising: • a CO2 storage tank, • a supply pump connected upstream to the CO2 storage tank and downstream to the supply orifice of the second module, - where appropriate at least one solvent storage tank connected to the fluid circuit(s), upstream of the supply orifice of the first and / or second module.

21. Recycling installation according to claim 20, the reservoir of the dense fluid being that of CO2

22. Recycling installation according to claim 20 or 21, comprising at least one fluid circuit for recovering and separating the dense fluid and the electrolyte of the accumulator(s), the circuit comprising one or more cyclonic separators in series, connected upstream to the discharge orifice of the first module.

23. Recycling installation according to one of claims 20 to 22, comprising at least one fluid circuit for recovering and separating CO2 and the accumulator binder(s), the circuit comprising one or more cyclonic separators in series, connected upstream to the discharge port of the second module.

24. Electrochemical bundle of a recycled metal-ion electrochemical accumulator according to the method of one of claims 1 to 12.

25. Electrochemical bundle according to claim 24 of a Li-ion accumulator in which: - the negative electrode(s) material is chosen from the group comprising graphite, lithium, silicon, titanate oxide Li4 TiOsOn; - the positive electrode(s) material is chosen from lithium cation insertion materials which are generally composite, such as lithium iron phosphate LiFePO4, lithium cobalt oxide LiCoO2, lithium manganese oxide, possibly substituted, LiMn2O4 or transition metal oxide, such as lamellar materials for example, a material based on LiNixMnyCozO2 with x+y+z = 1, such as LiNio.33Mn0.33Coo.3302 or LiNio.8Mn0.iCoo.i02, or a material based on nickel cobalt aluminum oxide type LiNixCoyAlzO2 with x +y+z = 1, such as LiNio.8Coo.i5Alo.o502.

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