process for extracting residual metallic lithium from a set of electrical energy storage cell(s)

Abstract

The invention relates to a method for safely extracting residual lithium from an assembly of electrical energy storage cells, in particular an electric battery, comprising residual solid metallic lithium, as well as a complete method for extracting lithium from an assembly of electrical energy storage cells, in particular an electric battery, comprising solid metallic lithium, implementing said residual lithium extraction method. It also relates to a residual lithium extraction unit implementing said residual lithium extraction method. Figure: Fig. 1

Description

Title of the invention: Method for extracting residual metallic lithium from an assembly of electrical energy storage cell(s)

[0001] The present invention relates to a method for safely extracting residual metallic lithium from an assembly of electrical energy storage cell(s), in particular from an electric battery, comprising residual solid metallic lithium, as well as a complete method for extracting lithium from an assembly of electrical energy storage cell(s), in particular from an electric battery, comprising solid metallic lithium, implementing said residual lithium extraction method. It also relates to a residual lithium extraction unit implementing said residual lithium extraction method.

[0002] The field of the invention is the field of solid metallic lithium batteries, and in particular Lithium-Metal-Polymer batteries, and even more particularly the field of recycling these batteries. State of the art

[0003] Solid-state lithium-metal batteries, such as Lithium-Metal-Polymer (LMP®) batteries, are known. Safer and more energy-dense, these batteries are increasingly used, for example in the electric mobility and renewable energy storage sectors. Consequently, the number of solid-state lithium-metal batteries has been steadily increasing for several years, as has the number of batteries reaching the end of their life. However, even at the end of its life, a battery still contains solid-state lithium-metal, which can be reused in other batteries or in other fields, and whose value is not negligible.

[0004] Today, the treatment of end-of-life lithium batteries has become a regulatory requirement. The new European regulation on batteries notably provides for the recycling of at least 65% of the battery's weight by 2026 and the recovery of at least 50% of the lithium contained in these batteries.

[0005] Also, the recycling of valuable metals contained in these batteries, particularly metallic lithium, has become economically advantageous due to the surge in the price of these metals. This price increase is due to strong market demand for these energy transition metals in the battery industry.

[0006] In this context, there are currently very few techniques for recovering metallic lithium from an all-solid-state battery (i.e., for recovering lithium in the zero oxidation state present in an all-solid-state battery, particularly in the negative electrode). These few techniques involve heating the battery to a temperature greater than or equal to the melting point of metallic lithium. to recover lithium in liquid form. Other techniques involve crushing the battery under controlled atmosphere (CO2, Ar, etc.) or under cryogenic conditions (e.g., -150°C) to prevent the metallic lithium from reacting during crushing. However, these techniques present a risk of battery fire, and the processing conditions are expensive and industrially demanding. Other processes are described for separating different metals (including lithium) present in the active materials of the positive electrodes of lithium-ion batteries. However, these processes are lengthy and complex and concern lithium-ion batteries, which have structures / materials and behaviors very different from those of lithium metal batteries. In particular, the metallic lithium in all-solid-state batteries behaves differently from the ionic lithium in lithium-ion batteries.

[0007] From international application WO2020 / 161339, a process for recovering metallic lithium from an assembly of at least one electric battery cell comprising solid metallic lithium is known. This process includes an extraction phase comprising the following steps: positioning the assembly in an orientation in which a first edge of the assembly, from which one or more negative electrodes protrude, is located below a second edge of the assembly, opposite the first edge, from which one or more positive electrodes protrude; and heating the assembly to a temperature, referred to as the processing temperature, greater than or equal to the melting temperature of the solid metallic lithium. Once melted, the metallic lithium is naturally evacuated, in whole or in part, from each cell by the force of gravity.

[0008] However, this solution is not entirely satisfactory because the extraction of metallic lithium is not optimized. In particular, the resulting batteries contain lithium residues that remain attached to the battery components at the end of the process. Therefore, battery cells produced by this method cannot be processed using conventional battery recycling methods, and the cathode contained within the cells cannot be recovered.

[0009] One object of the present invention is to remedy this drawback.

[0010] Another object of the invention is to propose a method for recovering residual solid metallic lithium in an assembly of at least one electrical energy storage cell, in a simple and economical manner.

[0011] Another object of the invention is to propose a method for recovering residual solid metallic lithium in an assembly of at least one electrical energy storage cell, in an efficient manner by limiting and controlling the effect of short-circuit potentials during recycling.

[0012] Another object of the invention is to propose a method for recovering residual solid metallic lithium in an assembly of at least one cell of electrical energy storage while minimizing liquid effluents which can pose problems both in terms of their environmental impact (risk of soil contamination, groundwater, etc.) and in terms of their management which could require large equipment for their storage, implementation and / or treatment. Description of the invention

[0013] The invention relates first to a method for extracting residual lithium from an assembly of electrical energy storage cell(s) comprising residual solid metallic lithium, said method comprising at least the following steps: i) a step of grinding said assembly to form a first grind comprising metallic lithium, ii) a step of exposing the first grind to humid air to form a second grind comprising oxidized lithium, iii) a step of drying the second grind comprising oxidized lithium, and iv) a screening step to separate the oxidized lithium from a third grind.

[0014] The process according to the invention proposes to recover the residual solid metallic lithium from a set of electrical energy storage cell(s), by treating the cell(s) of said set individually or together.

[0015] In the present invention, "solid metallic lithium" or "solid metal lithium" means solid lithium in the zero oxidation state.

[0016] Furthermore, the process according to the invention proposes to recover, in an oxidized form, the residual solid metallic lithium from a set of electrical storage cell(s), by grinding said set to finely fractionate said set, then reacting said residual solid metallic lithium with humid air to slightly wet the ground material and form oxidized lithium within said ground material. The oxidized lithium can then be selectively and easily recovered by screening.

[0017] Thus, the process according to the invention allows a simple and uncomplicated recovery of residual solid metallic lithium in an oxidized form.

[0018] Furthermore, the process according to the invention can provide for the recycling of the active material of the positive electrode as well as the current collector. In particular, the process can make it possible to form intermediate products from the active materials of the positive electrode that can be easily reused or recycled in industrial applications.

[0019] Finally, the process of the invention differs from those of the prior art that use liquid effluents for all or part of the steps involved. The process of the invention has the advantage of avoiding the use of large quantities of liquid effluents, and consequently does not require large facilities. industrial storage and management of these liquid effluents (storage tanks, pumps, etc...).

[0020] In the present application, each electrical energy storage cell in the cell assembly(ies) preferably comprises residual solid metallic lithium.

[0021] In the present application, the expression "each cell includes residual solid metallic lithium" means that each electrical energy storage cell implemented in step i) is delithiated at least in part.

[0022] According to a preferred embodiment, each electrical energy storage cell (or elementary cell) comprises: - residual solid metallic lithium, in the form of a layer and / or debris, particularly originating from the negative electrode, - a positive electrode, particularly in the form of a layer, - a solid or quasi-solid electrolyte comprising a lithium salt, particularly in the form of a layer, said solid or quasi-solid electrolyte being disposed next to the positive electrode, and - a current collector associated with and / or next to the positive electrode. In other words, when said assembly comprises several cells, said assembly preferably comprises residual solid metallic lithium (from a plurality of films or layers of negative electrodes), and a plurality of films or layers of solid or quasi-solid electrolytes, positive electrodes, and current collectors. Said assembly (also called a "wafer") may comprise from 10 to 50 cells (also called elementary cells).

[0023] In the present application, "residual solid metallic lithium" may include: residual pure metallic lithium; or at least one residual metallic lithium alloy; or a combination of residual pure metallic lithium and at least one residual metallic lithium alloy.

[0024] Step i): grinding of said assembly

[0025] The assembly implemented in step i) may include a single electrical energy storage cell or several electrical energy storage cells.

[0026] When the assembly comprises several cells (e.g., at least two cells), they are preferably assembled, or in particular stacked, according to an assembly direction. The assembly direction may be perpendicular to the plane formed by each electrical energy storage cell. The assembly or disc may, in particular, originate from a module initially comprising several assemblies (e.g., 10 to 20 assemblies) which are first separated from each other and conveyed in bulk via a conveyor to a grinding unit as described below.

[0027] The assembly implemented in step i) preferably corresponds to a battery, and particularly preferably in which several cells are connected in series.

[0028] The assembly implemented in step i) includes residual solid metallic lithium. According to a preferred embodiment of the invention, the residual solid metallic lithium represents in the cell assembly(ies) implemented in step i) at most about 20% by mass, preferably at most about 15% by mass, and particularly preferably at most about 10% by mass, relative to the total mass of solid metallic lithium present in a non-delithiated cell assembly(ies).

[0029] The process includes a step i) of grinding the set of cell(s), and preferably all the (elementary) cells of the set.

[0030] According to a particularly preferred embodiment of the invention, step i) is a dry grinding step.

[0031] Step i) can be implemented with at least one first grinding element, such as a knife mill, a jaw crusher, or a disc mill. The first grinding element is intended to grind a set of electrical energy storage cell(s) comprising residual solid metallic lithium.

[0032] The grinding unit can be equipped with a cooling system to prevent the material from heating up during grinding in order to reduce industrial risk.

[0033] Step i) can have a grinding throughput of at least 200 kg / h, and preferably from 200 to 500 kg / h. The duration of step i) will depend on the number of cells in the assembly and / or the size of the cells, and in particular on the presence or absence of prior cell cutting steps as described below.

[0034] Step i) preferentially leads to a first ground material having a particle size of 20 mm or less, and particularly preferably 10 mm or less. This improves the oxidation kinetics in humid air during the following step ii) and accelerates the industrial production rate. The first ground material comprises metallic lithium or lithium metal (i.e., lithium in its zero oxidation state).

[0035] Step i) preferentially leads to a first ground material having a particle size greater than or equal to 3 mm, and particularly preferably greater than or equal to 5 mm. This avoids a step i) that is too long and / or too energy-intensive and / or generates an excessive volume of potentially dangerous fine dust.

[0036] Step ii): exposure to humid air

[0037] Step ii) is carried out with a set of ground cell(s) or with one or more ground cell(s). In other words, the first grind corresponds to one or more ground cell(s).

[0038] Step ü) is a step involving exposing the first ground material to humid air to form a second ground material containing oxidized lithium. This step also refers to bringing the first ground material into contact with humid air to form a second ground material containing oxidized lithium. This step allows for the oxidation of solid lithium metal while ensuring good safety conditions.

[0039] In one embodiment, step ii) is carried out in a controlled manner to allow for the gradual generation of dihydrogen, for example, by means of continuous gas extraction to the outside. The extraction allows for ventilation of the oxidation medium (for example, of the enclosure as described below), in order to dilute the dihydrogen emitted into the air so that the air has a dihydrogen concentration strictly less than 4% by volume. This prevents reaching an air flammability threshold.

[0040] Step ii) can be implemented in an enclosure intended to receive ground material, said enclosure being equipped with at least one humid air distribution device.

[0041] Preferably, step ii) is carried out under stirring, and particularly preferably under mechanical stirring. This promotes the wetting of the first ground material and the homogeneous oxidation of metallic lithium.

[0042] Step ii) can then be carried out in a mixer, preferably equipped with at least one humid air distribution device. The mixer may include one or more stirring devices, or the mixer may be configured to be mobile.

[0043] The mixer may include a shaft equipped with a mechanical stirring device such as rotating blades.

[0044] The mixer is advantageously a horizontal mixer. This allows for easier loading of the first crushed material and unloading of the second crushed material.

[0045] Step ii) can be carried out in a rotating cylinder, preferably with means for controlling the rotational speed of said cylinder, or in a fixed cylinder equipped with stirring devices such as rotating blades. This promotes the mixing of the first ground material during exposure to humid air and ensures homogeneous lithium oxidation, the aim being to achieve 100% oxidation of the residual metallic Li.

[0046] Step ii) can be carried out with a humid air flow rate of approximately 1 l / h to 10 l / h, and preferably of approximately 2 l / h to 5 l / h.

[0047] Step ii) is generally carried out at a temperature of approximately 20°C to 30°C, and preferably at room temperature (i.e. approximately 18-25°C).

[0048] The oxidized lithium formed in step ii) is preferably LiOH and / or LiO2, and particularly preferably LiOH.

[0049] In the invention, oxidized lithium means a lithium compound in which the oxidation state of lithium is +1 and comprising, in addition to lithium, one or more oxygen atoms, and possibly one or more hydrogen atoms. The oxidized lithium is preferably inorganic (i.e., without carbon atom(s)), and particularly preferably the oxidized lithium does not contain any metals other than lithium.

[0050] According to a preferred embodiment of the invention, step ii) is carried out by injecting humid air onto the first ground material, and particularly preferably by spraying humid air onto the first ground material. Thus, step ii) is preferably carried out using at least one humid air distribution device.

[0051] According to a preferred embodiment of the invention, step ii) is carried out by injecting compressed air (i.e., ambient air maintained at a pressure greater than atmospheric pressure) in combination with water misting. Step ii) can thus be implemented with a humid air distribution device comprising at least one compressed air distribution means and at least one misting means.

[0052] The misting means can be a water generator operating at 40-60 bar, equipped with nozzles.

[0053] During step ii), the enclosure or mixer may be equipped with an open hopper to remove the hydrogen formed.

[0054] In step ii), the air used in humid air may comprise nitrogen and oxygen, with varying respective amounts of nitrogen and oxygen. Preferably, the air comprises approximately 1 volume of oxygen for every 4 volumes of nitrogen.

[0055] Step iii): drying of the second grinding

[0056] The process includes a step iii) of drying the second powder containing oxidized lithium. This step iii), which follows step ii) and precedes step iv), improves step iv). A second dried powder is thus obtained. Step iii) prevents the oxidized lithium powder from remaining bound within the second powder and thus facilitates the subsequent screening step iv).

[0057] Step iii) is preferably carried out in air, and even more preferably in dry air.

[0058] In a preferred embodiment, step iii) is carried out by circulating within the second ground material a hot fluid such as hot air, advantageously a fluid heated to a temperature ranging from approximately 40°C to 100°C, and preferably from approximately 50°C to 70°C.

[0059] Step iii) can be carried out with drying means.

[0060] In particular, step iii) can be carried out in a mixer, for example as defined above, said mixer further comprising a double jacket equipped with means for supplying a fluid such as air and means for heating said fluid. The heated fluid thus circulates in the double jacket or The double wall of the mixer dries the second batch of ground material. The drying means are therefore a combination of the double wall, the fluid, the fluid supply means, and the heating means.

[0061] Step iv): screening

[0062] Screening step iv) separates the oxidized lithium from a third ground material. Step iv) performs particle size sorting of the oxidized lithium and the active materials from the positive electrodes and current collectors. Thus, the oxidized lithium in the form of particles is separated from the particles of active materials from the positive electrodes and current collectors, which have a coarser particle size than the oxidized lithium particles formed in step ii). This yields, on the one hand, the oxidized lithium and, on the other hand, a third ground material (remaining ground material) comprising the particles of active materials from the positive electrodes and current collectors.

[0063] This physical separation step allows for dry separation, i.e., without the use of liquid effluents and / or toxic or environmentally harmful reagents. Step iv) is preferably a dry screening step.

[0064] In particular, step iv) implements the separation of particles with a particle size of less than about 400 pm, and preferably less than about 200 pm.

[0065] The screening step iv) can be carried out using at least one first screening device which can be any type of screen or sieve, vibrating, gyratory, or rotary, and preferably using a vibrating sieve.

[0066] The third ground material is preferably free of lithium and / or oxidized lithium.

[0067] Step v): pyrolysis of the third ground material

[0068] The process may further include, after step iv), a step v) of pyrolysis of the third ground material. This step allows for the recycling of the active materials from the positive electrodes and the current collectors. This step v) is a thermal oxidation step. Step v) yields a pyrolysate.

[0069] Step v) is preferably carried out at a temperature of at least approximately 400°C, and particularly preferably from approximately 400°C to 500°C. Step v) makes it possible, in particular, to decompose the solid or quasi-solid electrolyte, or at least its main constituent, which is a polymer material. Step v) also makes it possible to decompose the polymer material or the organic binder that connects the positive electrode particles to each other and to fix them to the current collector (aluminum film). After decomposition, the positive electrode particles are released and can be easily separated from the current collector in step vi) as described below.

[0070] Step v) can thus be implemented with heating means. The heating means can be a heated enclosure or cavity.

[0071] Step v) is preferably carried out under agitation, such as for example under mechanical agitation.

[0072] In particular, step v) can be implemented in a rotating heated enclosure or cavity, or in a fixed heated enclosure or cavity equipped with a conveyor.

[0073] More specifically, step v) is carried out using a rotary kiln (continuous or discontinuous mode), or a heating tunnel equipped with a conveyor (continuous mode).

[0074] Step v) preferably lasts from a few tens of minutes to a few hours depending on the heating technology, the stirring method, the volume of the enclosure used, and / or the quantity of materials to be pyrolyzed, etc.

[0075] At the end of step v), the active materials of positive electrodes are in an easily recoverable oxidized form.

[0076] In particular, the active materials for the positive electrodes can be transition metal phosphates such as lithium iron phosphate (LFP) and lithium iron manganese phosphate (LMFP). At the end of step v), transition metal oxides are obtained, such as red iron oxide, which can be used in the dye industry.

[0077] Step v'): grinding of the pyrolysate

[0078] The process may further comprise, after step v) (and preferably before step vi) as described below), a grinding step v') (of the pyrolysate) to form a fourth ground product. Step v') provides a mechanical action (friction) to dissociate the active material particles from the positive electrode(s) and the current collectors.

[0079] According to a particularly preferred embodiment of the invention, step v') is a dry grinding step.

[0080] Step v') can be implemented with at least one second grinding element, such as a knife mill.

[0081] Step v') can last at least 1 min, and preferably from 1 to 10 min. The duration of step v') will depend on the quantity of pyrolysate, the grinding technology, the volume of the grinder, the speed, and / or the hourly grinding volume (kg / h), etc.

[0082] Screening step vi)

[0083] The process may further include after step v) or v') (if it exists), a screening step vi) (of the pyrolysate or the fourth ground material) to separate one or more electrode active materials from one or more current collectors.

[0084] Step vi) enables particle size sorting of the active materials of the positive electrodes, transformed into powder or in a pulverized form, and of the current collectors. Thus, the active materials of the positive electrodes in the form of particles are separated from the particles of the current collectors, which have a larger particle size. coarser than that of the active material particles of positive electrodes formed in step v) and are included in the pyrolysate or the fourth ground.

[0085] This physical separation step allows for dry separation, i.e., without the use of liquid effluents and / or toxic or environmentally harmful reagents. Step vi) is preferably a dry screening step.

[0086] In particular, step vi) implements the separation of particles with a particle size of less than about 300 pm, and preferably less than about 200 pm.

[0087] The screening step vi) can be carried out using at least one second screening device which can be any type of screen or sieve, vibrating, gyratory, or rotary, and preferably using a vibrating sieve.

[0088] Through steps i), ii), iii), and iv), it is possible to recover the residual solid metallic lithium initially present in the cell(s) in the form of oxidized lithium. Furthermore, at the end of step iv), the oxidized lithium is separated from a third powder, which allows this third powder to be recovered in addition to the oxidized lithium.

[0089] Step a) of cutting the cells before step i)

[0090] The process may further include, before step i), a step a) of cutting the entire cell set(s), and preferably all the cells in the set. This reduces the grinding time during step i) and improves the subsequent step ii) of exposure to humid air. According to this embodiment, step i) is then carried out with a set of cut cells or with one or more cut cells.

[0091] Step a) can be implemented with one or more cutting means, such as a metal cutter, a laser cutting machine, or an ultrasonic cutting machine.

[0092] The cutting step a) is preferably a dry cutting step.

[0093] The process is preferably carried out at atmospheric pressure. In other words, inert atmosphere conditions are not required.

[0094] The process of the invention is a quasi-dry process in that the only water input is that of step ii) by means of the use of humid air.

[0095] The invention also relates to a method for the complete extraction of lithium from a set of electrical energy storage cell(s) comprising solid metallic lithium, said method comprising: A) a first method for extracting lithium from a set of electrical energy storage cell(s), each cell comprising a negative electrode containing solid metallic lithium, a positive electrode, a solid or quasi-solid electrolyte, and optionally a current collector, said cell assembly(ies) comprising a first border from which the negative electrode(s) of said cell(s) protrude and a second border, opposite said first border, from which the positive electrode(s) protrude, said process comprising an extraction phase comprising the following steps: - positioning said assembly in an orientation in which one of said first and second borders is below the other of said first and second borders, and - heating said assembly to a temperature, called the processing temperature, greater than or equal to the melting temperature of said solid metallic lithium, said first extraction process leading to an assembly of electrical energy storage cell(s) comprising residual solid metallic lithium, and B) a second process for extracting residual lithium in accordance with the first object of the invention.

[0096] The first method according to A)

[0097] When the assembly comprises several cells (i.e., at least two cells), each cell comprises a positive electrode, a negative electrode containing solid metallic lithium, a solid or quasi-solid electrolyte, and optionally a current collector. The assembly comprises a first border from which the negative electrodes of the cells protrude and a second border, opposite the first border, from which the positive electrodes protrude. In this embodiment, the first method preferably further comprises a step of breaking the electrical connection between the positive electrodes of at least two, and in particular of all, the cells of the assembly.

[0098] Each electrical energy storage cell preferably comprises: - a negative electrode containing solid metallic lithium, in particular in the form of a layer, - a positive electrode, particularly in the form of a layer, - a solid or quasi-solid electrolyte comprising a lithium salt, particularly in the form of a layer, said solid electrolyte being disposed between the positive electrode and the negative electrode, and - a current collector associated with and / or next to the positive electrode.

[0099] In the first process according to A), the "solid metallic lithium" may comprise: pure metallic lithium; or at least one metallic lithium alloy; or a combination of pure metallic lithium and at least one metallic lithium alloy.

[0100] The implemented assembly may comprise a single electrical energy storage cell or several electrical energy storage cells, preferably assembled, or in particular stacked, according to an assembly direction. The assembly direction can be perpendicular to the plane formed by each electrical energy storage cell.

[0101] According to a preferred embodiment of the invention, the assembly corresponds to an electric battery, and particularly preferably in which the cells are connected in series.

[0102] The assembly implemented in the process according to A) comprises solid metallic lithium. According to a preferred embodiment of the invention, the solid metallic lithium represents in the cell assembly(ies) implemented in the process according to A) at least 80% by mass, preferably at least 85% by mass, and particularly preferably at least 90% by mass approximately, relative to the total mass of solid metallic lithium present in a non-lithiated cell assembly(ies).

[0103] The first process according to A) makes it possible to extract the vast majority of the solid metallic lithium from the cell(s) so as to leave only residual solid metallic lithium. The second process according to B) is consistent with the first object of the invention and makes it possible to extract all of the residual solid metallic lithium.

[0104] When the "solid metallic lithium" comprises a combination of different forms of lithium, such as those indicated above, having different melting points, then the heating step of the entire cell assembly(ies) is carried out at a processing temperature greater than or equal to: - the lowest of said different melting points; and - preferably, the highest of the said different melting temperatures.

[0105] Thus, the first process according to A) proposes to recover the solid metallic lithium from an assembly by heating said assembly to a processing temperature greater than or equal to the melting temperature of solid metallic lithium. Once melted, the metallic lithium is naturally released, in whole or in part, from each cell. Thus, the first process according to A) allows for a simple and uncomplicated recovery of the vast majority of the solid metallic lithium.

[0106] Furthermore, the first method according to A) proposes a specific orientation for each cell, the latter being, at a minimum, inclined. Such an orientation of each cell facilitates the flow of molten lithium out of the cell by gravity.

[0107] Moreover, and most importantly, the first method according to A) preferably involves breaking the connection between the positive electrodes of at least two, and more preferably, of all the cells in the assembly. In other words, the breaking step severs the electrical connection between the positive electrodes of the cells in the assembly. Thus, after the breaking step, the assembly comprises a plurality of cells that are no longer electrically connected to each other, which reduces the reactivity of the system, and therefore the risk of fires during lithium recovery.

[0108] The first border can be characterized by the fact that it defines the side through which the lithium, once in the liquid state, must flow.

[0109] The first method according to A) can be implemented to process several sets of cell(s), in particular several sets of cell(s) forming a battery pack and connected together in parallel within said battery pack.

[0110] At least two sets of cell(s) can be aligned side by side, without overlapping, for example in a direction parallel to the first border. [YES] Heating

[0112] Following a non-limiting example embodiment, the processing temperature is greater than or equal to 180.5°C.

[0113] According to one embodiment, the treatment temperature is less than or equal to a maximum temperature, for example 300°C.

[0114] Heating can be carried out using metal heating plates or a metal heating enclosure.

[0115] Cut

[0116] The cutting step can be performed: - by cutting connecting wires between the positive electrodes along a cutting line located at, and in particular at the boundary of, the second edge, on the side of said electrical connecting wires; or - by cutting the cells along a cutting line located at the level, and in particular at the limit, of the second border, on the side of said cells.

[0117] The first alternative allows for the retention, or not removal, of solid metallic lithium from the assembly, when the electrical connections are cut, which improves the lithium recovery efficiency.

[0118] In this first alternative, the cutting of the connecting wires must be sufficiently close to the second edge so that after the cutting there is no longer any contact between the different positive electrodes.

[0119] In the second alternative, in order to reduce the amount of lithium lost, the cut must be in the immediate vicinity of the second edge.

[0120] For example, the cut can be made at a distance "d" from the second edge less than or equal to 2 mm, or less than or equal to 1% of the cell dimension between the first and second edges of the battery.

[0121] The cutting step can be carried out by guillotine cutting.

[0122] In this case, the assembly is inserted into a cutter of suitable size and power.

[0123] The switching step can be carried out before the start of the heating step or after the start of the heating step. In the latter case, preferably, the switching step can be carried out before the solid metallic lithium begins to melt.

[0124] The cutting step can be carried out before the positioning step, after the positioning step, or during the positioning step.

[0125] Electrical charging

[0126] According to a particularly advantageous feature, the first process according to A) may further include, before the extraction phase, an electrical charging step of the cell assembly(ies), said extraction phase being applied to said charged assembly.

[0127] Electrically charging the entire cell assembly and performing the extraction phase on the electrically charged cells increases the lithium extraction yield. Indeed, the electrical charging of a cell moves lithium ions towards the negative electrode, thereby increasing the amount of lithium that can be recovered.

[0128] Each cell can be charged individually, or by electrically charging the entire set of cell(s).

[0129] Compression

[0130] According to a particularly advantageous embodiment, the extraction phase may further include a step of compressing the set of cell(s).

[0131] Thus, the molten lithium is forced to escape from each cell, thereby increasing the amount of lithium recovered.

[0132] The compression step can be performed continuously throughout the extraction phase, or discretely, once or several times, during the extraction phase. In the first case, each cell is subjected to compression, in part or in full, for the entire duration of the extraction phase. In the second case, the extraction phase includes periods when the entire cell group is not subjected to compression.

[0133] Advantageously, the compression step can apply compression to the surface of the cell assembly(ies) by sweeping the surface of the cell assembly(ies) from the second edge to the first edge. Thus, the molten lithium is gradually brought / guided towards the first edge from which one or more negative electrode(s) protrude, thereby increasing the amount of lithium recovered and reducing the risk of contact between the lithium and the positive electrode(s).

[0134] For example, the compression step can be carried out by passing the set of cell(s) between two rollers or by means of a compression roller compressing the set of cell(s) against a support surface.

[0135] The compression step can be carried out simultaneously with the heating step. This avoids the cooling of the lithium during compression. In this embodiment, the compression roller(s) can be heated rollers.

[0136] Compression can be applied by successive passes, each pass scanning the surface of the set of cell(s) starting from the second border towards the first border.

[0137] The space between the compression rollers, or between the compression roller and the bearing surface, can correspond to the thickness of the cell assembly(ies) minus the thickness of the solid metallic lithium layers. This allows compression to be applied as long as solid lithium remains in the cell assembly(ies).

[0138] The space between the two compression rollers, respectively between the compression roller and the bearing surface, can be reduced with successive passes, so as to always apply compression to the entire cell(s).

[0139] The speed of passage between the compression rollers, respectively of the compression roller, and more generally the scanning speed, can be between a few mm and a few tens of mm per second.

[0140] Removal of connectors and overflows

[0141] Furthermore, the first process according to A) may include, prior to the extraction phase, a step of removing at least one electrical connector from the cell assembly(ies), also known as a "crimp". This facilitates the processing of the cell assembly(ies).

[0142] In addition, the first process according to A) may include, before the extraction phase, a step of removing overflows of material at the level of at least one, and particularly each, border of the set of cell(s).

[0143] Positioning

[0144] According to a first version, the positioning step can perform a positioning of the set of cell(s) in an orientation in which the first border of the set of cell(s) is below the second border of the set of cell(s).

[0145] Such an orientation of the cell assembly(ies), and therefore of each cell of the cell assembly(ies), makes it possible on the one hand to facilitate the flow of molten lithium out of the cell by gravity, and on the other hand to avoid contact between the molten lithium and the positive electrodes or the current collector of the positive electrode, such contact being able to cause an electrical short circuit or an electric arc, such a short circuit being able to cause a fire.

[0146] According to a preferred embodiment of this first version, the positioning step can perform a vertical positioning of the set of cell(s), in which the first border is at the bottom.

[0147] Thus, the flow of molten lithium out of each cell, by gravity, is improved.

[0148] Furthermore, the risk of contact between the molten lithium and the positive electrode(s) is reduced, or even eliminated.

[0149] Preferably, in this first version, the heating step of the entire cell assembly(ies) can be carried out under an inert gas. Thus, the process according to the invention reduces the risk of accidents, particularly the risk of fire. Furthermore, the formation of polluting compounds that can be generated by unwanted or even uncontrolled physicochemical reactions during lithium extraction is avoided.

[0150] Following a non-limiting example of embodiment, the inert gas may be, or comprise, any of the following gases: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe) and radon (Rn).

[0151] According to another embodiment of this first version, the heating step of the cell assembly(ies) can be carried out under vacuum.

[0152] According to another embodiment of this first version, the heating step of the entire cell(s) assembly can be carried out under dry air, in particular containing less than 0.002% by mass of H2O.

[0153] According to a second version, the positioning step can position the cell assembly(ies) in an orientation in which the first edge of the cell assembly(ies) is above the second edge of the cell assembly(ies). In this case, the extraction phase further includes, before the heating step, an immersion step of the cell assembly(ies) in a liquid, called the treatment liquid, which is denser than liquid lithium and electrically insulating.

[0154] This second version proposes a specific orientation for each cell, which is at least slightly inclined, so that the first edge from which the negative electrode(s) protrude is located above the level of the second edge, opposite the first edge, from which the positive electrode(s) protrude. This orientation of each cell facilitates the flow of molten lithium out of the cell due to density differences and prevents contact between the molten lithium and the positive electrodes or the current collectors of the positive electrodes, as such contact could cause an electrical short circuit, which in turn could cause a fire. Furthermore, immersing the entire cell assembly in a liquid improves heat dissipation from the cell, particularly during a short circuit, and thus significantly limits its impact.

[0155] In this application, "density" means the ratio of the mass density of the liquid in question to the mass density of water.

[0156] According to a preferred embodiment of this second version, the positioning step can perform a vertical positioning of the set of cell(s), in which the second border is at the bottom.

[0157] Thus, the flow of molten lithium out of each cell is improved by density difference.

[0158] Furthermore, the risk of contact between the molten lithium and the positive electrodes is reduced, or even eliminated.

[0159] Preferably, the immersion step can be carried out by immersing the entire cell assembly(ies) completely in the treatment liquid.

[0160] The liquid may be a natural or synthetic oil, having the following physico-chemical properties: - hydrophobic and non-reactive towards lithium, - electrical insulator, - having a density higher than that of lithium, - thermally stable beyond the melting point of lithium, i.e. 180.5°C, - a flash point, as well as an auto-inflammation point, as high as possible.

[0161] The invention also relates, as a third object, to a unit for extracting residual lithium from a set of electrical energy storage cell(s) comprising residual solid metallic lithium, characterized in that it comprises: - at least one first grinding element intended to grind a set of electrical energy storage cell(s) comprising residual solid metallic lithium; - an enclosure intended to receive a first batch of ground material, said enclosure being equipped with at least one humid air distribution device; and - at least one first screening element to separate oxidized lithium from a third ground material.

[0162] The extraction unit according to the third object makes it possible to implement the process according to the first object of the invention, and in particular steps i) to iv).

[0163] The first grinding element can be as defined in the first object of the invention.

[0164] The enclosure intended to receive a ground material is preferably a mixer, particularly preferably a mixer as defined in the first object of the invention, and more particularly preferably a rotating cylinder or a fixed cylinder equipped with stirring elements, said cylinders being as defined in the first object of the invention.

[0165] The humid air distribution unit preferably comprises at least one compressed air distribution means and at least one misting means.

[0166] The misting means may be as defined in the first object of the invention.

[0167] The enclosure can be equipped with an open hopper to remove the hydrogen formed.

[0168] The screening device may be as defined in the first object of the invention.

[0169] The residual lithium extraction unit may further include means for drying as defined in the first object of the invention. This makes it possible to implement step iii) described above of the process according to the first object of the invention.

[0170] The residual lithium extraction unit may further include heating means for carrying out step v) described above of the process according to the first object of the invention. The heating means may be as defined in the first object of the invention.

[0171] The residual lithium extraction unit may further comprise a second grinding element (in order to implement step v') described above of the process according to the first object of the invention). The second grinding element may be as defined in the first object of the invention.

[0172] The residual lithium extraction unit may further include a second screening element (in order to implement step vi) described above of the process according to the first object of the invention). The second screening element may be as defined in the first object of the invention.

[0173] The residual lithium extraction unit may further include one or more cutting means, these being as defined in the first object of the invention (for the implementation of step a)).

[0174] In general, the residual lithium extraction unit may include means configured to implement any combination of at least one of the features described in the first object of the invention, which are not repeated here in detail for the sake of brevity.

[0175] The invention relates as a fourth object an integral installation for extracting lithium from a set of electrical energy storage cell(s), each cell comprising a positive electrode, a negative electrode comprising solid metallic lithium, a solid or quasi-solid electrolyte, and optionally a current collector, said assembly comprising a first border from which protrudes the negative electrode(s) of said cell(s) and a second border, opposite said first border, and from which protrudes the positive electrode(s), said extraction installation comprising: * a lithium extraction unit leading to a set of cell(s) comprising residual solid metallic lithium, said lithium extraction unit containing: - a means of positioning said assembly in an orientation in which one of said first and second borders is located below the other of said first and second borders; and - a heating means configured to heat said assembly to a temperature, called the processing temperature, greater than or equal to the melting temperature of said solid metallic lithium, and * a residual lithium extraction unit according to the third object of the invention.

[0176] Said lithium extraction unit may further include a means for breaking the electrical connection between the positive electrodes of at least two, and in particular of all, cells of said assembly.

[0177] In general, the installation may include means configured to implement any combination of at least one of the features described in the second object of the invention, which are not repeated here in detail for the sake of brevity.

[0178] For example, the cutting means may include a guillotine.

[0179] In particular, the heating means may include a metal oven (heating chamber) or metal heating plates.

[0180] Advantageously, the oven can be filled with an inert gas, dry air or be placed under vacuum, or be filled with a treatment liquid denser than liquid lithium.

[0181] Said lithium extraction unit may further include a means for compressing said assembly.

[0182] The compression means may include at least one roller.

[0183] In particular, the compression means may comprise a single roller compressing the cell assembly(ies) against a support surface. The support surface may be heated to accelerate the temperature rise of the cell assembly(ies).

[0184] Alternatively, the compression means may comprise two rollers between which the set of cell(s) is passed.

[0185] In general, the compression means can be configured to apply continuous compression throughout the extraction phase.

[0186] Alternatively, the compression means can be configured to apply compression discretely over time, once or several times, during the extraction phase. In this case, the extraction phase includes moments when the set of cell(s) is not subjected to compression.

[0187] Advantageously, the compression means can be configured to apply compression, of constant or variable value, progressively or by sweeping across the surface of the cell assembly(ies), from the second edge to the first edge. Thus, the molten lithium is gradually brought / guided towards the first edge, which is in the lower position, thereby increasing the amount of lithium recovered and reducing the risk of contact between the lithium and the positive electrodes.

[0188] When using one or two compression rollers, compression can be applied to the assembly in successive passes. Each pass applies sweeping compression to the surface of the assembly, from the second edge to the first edge. At the end of each pass, the compression can be stopped by moving the rollers apart or by moving the roller away from the support surface, before returning to the second edge to begin a new pass.

[0189] The distance between the rollers, respectively between the compression roller and the bearing surface, can be decreased as the passes progress, and in particular between two successive passes.

[0190] Compression can be applied to at least two sets of cell(s) by the same compression means, namely a set of rollers, or a roller cooperating with a support surface.

[0191] The roller(s) are preferably heated rollers. Description of figures and examples

[0192] Other advantages and features will become apparent upon examination of the detailed description of non-limiting embodiments and the accompanying drawings on which: [Fig.1] [Fig.1] is a schematic representation of a first example of an embodiment of the process conforming to the first object of the invention; [Fig.2] [Fig.2] is a schematic representation of a second example of an embodiment of the process in accordance with the first object of the invention; [Fig.3] [Fig.3] is a schematic representation of an example of an implementation of a process conforming to the second object of the invention; [Fig.4] [Fig.4] is a photographic representation of the different products obtained in an example of implementation of steps i) to iv) of a process conforming to the first object of the invention; [Fig.5] [Fig.5] is a photographic representation of the different products obtained in an example of implementation of steps v) and vi) of a process conforming to the first object of the invention; [Fig.6] [Fig.6] is an XRD spectrum of a product obtained in an example of an embodiment of step vi) of a process according to the first object of the invention.

[0193] It is understood that the embodiments described below are in no way limiting. In particular, variants of the invention may be conceived comprising only a selection of the features described below, isolated from the other features described, if this selection of features is sufficient to confer a technical advantage or to differentiate the invention from the prior art. This selection includes at least one preferably functional feature without structural details, or with only a portion of the structural details if this portion is sufficient solely to confer a technical advantage or to differentiate the invention from the prior art.

[0194] In the figures, the elements common to several figures retain the same reference.

[0195] The process according to the first object of the invention, shown in [Fig. 1], comprises a first step (i) of grinding a set of cell(s), each cell comprising residual solid metallic lithium, a positive electrode, a current collector associated with the positive electrode, and a solid or quasi-solid electrolyte, to form a first grind. This step (i) allows the residual solid metallic lithium and the other elements of the set, such as the active materials of the positive electrodes and the current collectors, to be fractionated. Once the grinding has been carried out, a step (ii) of exposing the first grind to humid air is performed to form a second grind comprising oxidized lithium. The process further comprises a step (iii) of drying the second grind.Oxidized and dried lithium has a smaller particle size than the other elements, which allows for a screening step (iv) to separate the oxidized lithium from a third ground material.

[0196] The process according to the first object of the invention, shown in [Fig. 2], comprises the aforementioned steps i), ii), iii) and iv) as described above for [Fig. 1] and further comprises, prior to step i), a step a). This step a) is optional. According to [Fig. 2], a set of cell(s), each cell comprising residual solid metallic lithium, a positive electrode, a current collector associated with the positive electrode, and a solid or quasi-solid electrolyte, is cut according to step a), so as to obtain strips or pieces of cell(s) and to improve the subsequent grinding and formation of oxidized lithium. The process of [Fig.2] then includes step i) as described for [Fig.1], followed by steps ii) of exposing the first ground material to humid air to form a second ground material, iii) of drying the second ground material, and iv) of screening as described for [Fig.l] to obtain on the one hand oxidized lithium and on the other hand a third ground (ground. remaining) including active material particles of positive electrodes and current collectors.

[0197] The process may further include, after step iv), a step v) of pyrolysis of the third ground material to form a pyrolysate. This step v) allows for the recycling of active materials from positive electrodes and current collectors. This step v) is a thermal oxidation step. The process may further include, after step v) (and preferably before step vi) as described below), a step v') of grinding the pyrolysate to form a fourth ground material. The process may further include, after step v) or v') (if it exists), a screening step vi) (of the pyrolysate or the fourth ground material) to separate one or more active electrode materials from one or more current collectors.

[0198] The process according to the second object of the invention, shown in [Fig. 3], comprises, prior to the process according to the first object of the invention (process according to B), shown in Figures 1 and 2, a process for extracting the vast majority of solid metallic lithium from a set of cell(s), each cell comprising a negative electrode comprising solid metallic lithium, a positive electrode, optionally a current collector, and a solid or quasi-solid electrolyte (process according to A). Such a process according to A includes an optional step in which the electrical connectors, and in particular the current concentrators, also known as "crimps," of the battery are removed.

[0199] In a subsequent, optional step, excess material, and in particular solid metallic lithium, is removed from each lateral edge of the assembly.

[0200] Next, the process according to A) of the process according to the second object of the invention comprises a phase for extracting metallic lithium from the cells of the assembly. The extraction phase includes a step of positioning the assembly in an orientation in which the first edge from which the negative electrodes protrude is at a lower level than the second edge from which the positive electrodes and / or collectors protrude. In particular, the step positions the assembly in a vertical orientation, that is, parallel to the gravity vector, with the first edge from which the negative electrodes protrude facing downwards. Preferably, but in no way limitingly, the assembly is maintained in this orientation throughout the extraction phase.

[0201] The extraction phase further includes a step of heating the assembly to a processing temperature greater than or equal to the melting temperature of the solid metallic lithium present in the assembly, for example 180.5°C. This temperature will cause the solid metallic lithium to melt and be extracted from each cell by natural flow under the effect of gravity. Preferably, but by no means exclusively, the entire system is maintained at this temperature throughout the extraction phase. Advantageously, the heating stage is carried out in a closed chamber filled with an inert gas.

[0202] The extraction phase may further include an optional step of compressing the assembly to expel the molten lithium from each cell of the assembly. The compression may be performed continuously during all or part of the extraction phase. Alternatively, the compression step may be repeated discretely several times during the extraction phase. Preferably, the compression step applies compression progressively, or by sweeping, over the surface of the battery, starting at the second edge from which the positive electrodes protrude and moving towards the first edge from which the negative electrodes protrude.

[0203] The process includes a step of breaking the electrical connection between the positive electrodes / current collectors of at least two, and in particular all, of the cells in the assembly. Such a breaking step severs the electrical link between the positive electrodes of the cells in the assembly, thereby reducing the reactivity of the assembly. Thus, the risk of fire in the assembly during the extraction phase is reduced, so that the recovery of solid metallic lithium can be carried out more safely and with less risk.

[0204] In the example shown, the electrical connection disconnection step is carried out before the extraction phase. Alternatively, the disconnection step can be carried out during the extraction phase, before, during or after the positioning step, or before, during or after the heating step.

[0205] Furthermore, the invention is not limited to the embodiments described above, but can be applied to assemblies or batteries with solid or quasi-solid electrolyte not having a polymer at the cathode. The invention can be applied to any battery having solid metallic lithium and a cathode stable up to the melting point temperature of solid metallic lithium.

[0206] Example 1: Preparation of an electric battery comprising residual solid metallic lithium

[0207] A Lithium Metal Polymer (LMP®) battery module was disassembled and a set of battery cells was removed. Subsequently, a lithium extraction step was performed on the set by melting, according to the process described in document WO2023 / 036741 A2. The resulting lithium metal was weighed. In this example, 90% of the lithium metal initially present in the cell set was extracted. Residual solid lithium metal remains trapped within the battery cell set.

[0208] In particular, the assembly was preheated between two metal plates to 180.5°C to reach the melting point of metallic lithium. The cell was then passed between two heated rollers at a fixed temperature of 195°C to prevent cooling during the compression step. After passing between the two rollers, the lithium flowed and fell by gravity into a collection tank. The gap between the two rollers was set at 7 mm. This lithium extraction was carried out under dry air conditions.

[0209] Example 2: Extraction of residual lithium according to a process according to the invention

[0210] A set of all-solid-state lithium battery-type electrical storage cells comprising residual lithium (approximately 10% by mass relative to the total mass of lithium present in the initial battery) as prepared in Example 1 was ground using a knife mill sold under the trade name "Shini SG-1628N" (operating at 2.2 kW) equipped with a cutting chamber measuring 160 x 280 mm with 2 fixed blades and 3 x 4 offset moving blades. A 10 mm sizing screen was used. This grinding step yields a first powder with a particle size ranging from approximately 5 mm to 10 mm. The grinding time is estimated at 1 min. [Fig. 4] shows the powder obtained [step i)]. [Fig.4] shows a photo of the first crushed material ([Fig.4] a).

[0211] Approximately 1 kg of the ground material obtained in the previous step was introduced into a horizontal paddle mixer sold under the trade name "ML 12" by MAP, with a capacity of 12 liters and an installed power of approximately 1.1 kW. The paddle rotation speed was set at 30 rpm. The humid air intake rate was set at 1 liter / h. The processing time was set at 5 minutes. The end of the oxidation reaction of the residual metallic lithium is indicated by the cessation of dihydrogen emission, measured using the hydrogen sensor sold under the trade name "Orbisphere HACH," equipped with a "29015A" reference membrane, providing a measurement accuracy of approximately ±0.03 ppb. At the end of the reaction, an oxidized ground material is obtained [step ii)]. This is dried by injecting dry air under agitation for 10 min [step iii)]. The oxidized (second ground) and dried material obtained at the end of this step iii) is shown in [Fig.4].It comprises oxidized and dried lithium. Figure 4 shows a photograph of the second homogenate (Fig. 4b).

[0212] The oxidized homogenate obtained in the previous step is screened using a sieve shaker sold under the trade name "AS200" by Retsch. A 400 µm sieve mounted on a collection tray was used. The sieving time was set at 5 min. An oxidized lithium powder (e.g., LiOH) is thus obtained [step iv)]. The oxidized lithium powder is shown in [Fig. 4] ([Fig. 4] c). [Fig. 4] also shows the LiOH-free cell homogenate obtained after step iv) (third homogenate, [Fig. 4] d).

[0213] Example 3: cathode material recovery

[0214] Approximately 800 g of the third LiOH-free homogenate obtained in Example 2 was transferred into a stainless steel basket and placed in a MATAIR oven with a capacity of approximately 60 liters. The set temperature was set to 450°C. The heating rate to 450°C was set at 7°C / min. The homogenate was then held at 450°C for 1 h. After the oven cooled, the resulting pyrolysate was removed and shown in [Fig. 5] ([Fig. 5] a). The initially black cathode material had completely transformed into a red mixture containing iron oxide and iron / lithium phosphates. This transformation was confirmed by X-ray diffraction analysis as shown in [Fig. 6] [step v)].

[0215] In order to separate the red component corresponding to the active material of the positive electrode of the current collector (aluminum), the pyrolyzed powder (pyrolysate) from step v) was first ground using a "PM100" planetary ball mill to reduce the red component to powder [step v') to form a fourth powder]. Then, the Retsch "AS200" sieving machine as described in Example 2 was used. A 150 µm sieve mounted on a collection tray was used [step vi)]. The sieving time was set at 5 min. This yields, on the one hand, a mixture based on iron oxide as shown in [Fig. 5] b, and on the other hand, aluminum as shown in [Fig. 5] c, which allows these products to be used in industrial applications.

Claims

Demands

1. A process for extracting residual lithium from an assembly of electrical energy storage cell(s) comprising residual solid metallic lithium, said process comprising at least the following steps: i) a step of grinding said assembly to form a first grind comprising metallic lithium, ii) a step of exposing the first grind to humid air to form a second grind comprising oxidized lithium, iii) a step of drying the second grind, and iv) a screening step to separate the oxidized lithium from a third grind.

2. A process according to claim 1, characterized in that step i) leads to a first ground material having a particle size less than or equal to 20 mm.

3. A method according to claim 1 or 2, characterized in that step ii) is carried out under agitation.

4. A method according to any one of the preceding claims, characterized in that step ii) is carried out with a humid air flow rate from 1 1 / h to 10 1 / h.

5. A method according to any one of the preceding claims, characterized in that step ii) is carried out at a temperature ranging from 20°C to 30°C.

6. A method according to any one of the preceding claims, characterized in that step iv) implements the separation of particles with a particle size of less than 400 pm.

7. A process according to any one of the preceding claims, characterized in that the process further comprises, after step iv), a step v) of pyrolysis of the third ground material.

8. A method according to claim 7, characterized in that it further comprises after step v), a step v') of grinding to form a fourth ground.

9. A method according to claim 7 or 8, characterized in that the method further comprises after step v) or v'), a screening step vi) for separating one or more electrode active materials from one or more current collectors.

10. A process for the complete extraction of lithium from an assembly of electrical energy storage cell(s) comprising solid metallic lithium, said process comprising: A) a first process for the extraction of lithium from an assembly of electrical energy storage cell(s), each cell comprising a negative electrode containing solid metallic lithium, a positive electrode, a solid or quasi-solid electrolyte, and optionally a current collector, said assembly of cell(s) comprising a first border from which protrudes the negative electrode(s) of said cell(s) and a second border, opposite said first border, and from which protrudes the positive electrode(s),said process comprising an extraction phase including the following steps: - positioning said assembly in an orientation in which one of said first and second edges is below the other of said first and second edges, and - heating said assembly to a temperature, said treatment temperature, greater than or equal to the melting temperature of said solid metallic lithium, said first extraction process leading to an assembly of electrical energy storage cell(s) comprising residual solid metallic lithium, and B) a second residual lithium extraction process as defined in any one of the preceding claims.

11. A method according to claim 10, characterized in that it further comprises a step of breaking the electrical connection between the positive electrodes of at least two, and in particular of all the cells of said assembly.

12. A unit for extracting residual lithium from an assembly of electrical energy storage cell(s) comprising residual solid metallic lithium, characterized in that it comprises: - at least one first grinding element for grinding an assembly of electrical energy storage cell(s) comprising residual solid metallic lithium; - a chamber for receiving a first grinding material, said chamber being equipped with at least one humid air distribution element; and - at least one first screening element to separate oxidized lithium from a third ground material.

13. Complete lithium extraction installation from an assembly of electrical energy storage cell(s), each cell comprising a positive electrode, a negative electrode comprising solid metallic lithium, a solid or quasi-solid electrolyte, and optionally a current collector, said assembly comprising a first border from which protrudes the negative electrode(s) of said cell(s) and a second border, opposite said first border, and from which protrudes the positive electrode(s), said extraction installation comprising: * a lithium extraction unit leading to an assembly of cell(s) comprising residual solid metallic lithium, said lithium extraction unit containing: - a means for positioning said assembly in an orientation in which one of said first and second borders is below the other of said first and second borders;and - a heating means configured to heat said assembly to a temperature, called the processing temperature, greater than or equal to the melting temperature of said solid metallic lithium, and * a residual lithium extraction unit as defined in claim 12.;

Images