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

[0001] The present 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.

[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. These rare techniques involve heating the battery to a temperature equal to or greater than the melting point of metallic lithium to recover the lithium in liquid form. Other techniques involve crushing the battery under a controlled atmosphere (CO2, Ar, etc.). or under cryogenic conditions (for example at -150°C) to prevent the reaction of metallic lithium during grinding. However, these techniques present a risk of battery fire, and the processing conditions are expensive and industrially demanding.

[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 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 process for recovering residual solid metallic lithium in an assembly of at least one electrical energy storage cell while ensuring recycling of all or part of the liquids and solids used in said process. Description of the invention

[0013] The invention relates first to a method for extracting residual lithium from a set of electrical energy storage cell(s) comprising residual solid metallic lithium, said method comprising at least the following steps: i) immersion of said assembly in an aqueous composition, ii) separation of the solids (and / or solid residues) from the aqueous composition, iii) addition of at least one acid or one of its precursors capable of forming at least one lithium salt insoluble in the aqueous composition, and iv) recovery of the lithium salt.

[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] Furthermore, the process according to the invention proposes to recover, in the form of at least one salt, the residual solid metallic lithium from a set of electrical storage cell(s), by immersing said set in an aqueous composition in order to dissolve the residual solid metallic lithium, and then by reacting said dissolved lithium with an acid to form a salt insoluble in the aqueous composition which can then be easily recovered.

[0016] Thus, the process according to the invention allows a simple and uncomplicated recovery of residual solid metallic lithium.

[0017] In addition, the process according to the invention proposes a reuse of the aqueous composition for one or more subsequent closed-loop processes for recovering residual solid metallic lithium.

[0018] In the present application, each electrical energy storage cell in the cell assembly(ies) preferably comprises residual solid metallic lithium.

[0019] 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.

[0020] According to a preferred embodiment, each electrical energy storage cell comprises: - residual solid metallic lithium, in the form of a layer and / or debris, - 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 next to the positive electrode, and - a current collector associated with and / or next to the positive electrode.

[0021] 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.

[0022] The assembly implemented in step i) may comprise a single or unique electrical energy storage cell or several electrical energy storage cells.

[0023] When the assembly comprises several cells (e.g., at least two cells), they are preferably assembled, or in particular stacked, along an assembly direction. The assembly direction may be perpendicular to the plane formed by each electrical energy storage cell.

[0024] The assembly implemented in step i) preferably corresponds to an electric battery, and particularly preferably in which several cells are connected in series.

[0025] 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 20% by mass, preferably at most 15% by mass, and particularly preferably at most 10% by mass, relative to the total mass of solid metallic lithium present in a non-delithiated cell assembly(ies).

[0026] Step i): immersion of said assembly in an aqueous composition

[0027] This step allows the residual solid lithium to dissolve in the aqueous composition.

[0028] The assembly is immersed in the aqueous composition. In other words, the amount of aqueous composition is such that it completely covers the assembly. When the assembly comprises several electrical energy storage cells, all the cells are preferably immersed in the aqueous composition.

[0029] The aqueous composition preferably comprises at least 90% by mass of water, and particularly preferably at least 95% by mass of water, relative to the total mass of the aqueous composition. More particularly preferably, the aqueous composition consists solely of water.

[0030] The aqueous composition before immersion (i.e. before step i)) preferably has a neutral pH, i.e. ranging from 6.5 to 7.5, and particularly preferably is close to 7.

[0031] Step i) can be carried out using a soaking container or tank containing the aqueous composition. During step i), the assembly of electrical storage cell(s) is then in the soaking tank or container, and covered by the aqueous composition.

[0032] Step i) preferably lasts at least 30 minutes, and preferably from 1 to 2 hours. 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 cutting and / or grinding steps of the cells as described below. Dissolution is favored when the size of the cells used in the aqueous composition is reduced.

[0033] The process may further include, during step i), stirring the aqueous composition. This improves the delithiation kinetics. Mechanical stirring may be used. Step i) may be carried out with one or more stirring means, such as a shaft equipped with a mechanical stirring impeller.

[0034] The process may further include, during step i), heating the aqueous composition. This improves the delithiation kinetics. Step i) may be carried out with one or more heating means, such as, for example, a reactor equipped with a double wall through which a fluid circulates to heat the aqueous composition. The heating may be carried out at a temperature ranging from approximately 40°C to approximately 70°C. The heating may be started before immersion of the assembly, i.e., before step i).

[0035] Step i) preferentially leads to the delamination of the film(s) / layer(s) of solid or quasi-solid electrolyte, positive electrode and current collector.

[0036] Step ii) of solid / liquid separation

[0037] The process includes, between steps i) and iii), a step ii) of separating the solids (and / or solid residues) from the aqueous composition. This step ii) prevents excessive acid consumption in the subsequent step iii). Furthermore, at the end of step i), the positive electrode of the cell is not soluble in the aqueous composition and must be separated from the aqueous composition before step iii) in order to avoid contaminating the lithium salts with positive electrode residues and complicating the recovery of the lithium salts in step iv).

[0038] In step ii), solids (and / or solid residues) are separated from the aqueous composition; in particular, solids (and / or solid residues) are removed or discharged from the soaking tank or container. Step ii) can be carried out using one or more means of separating the solids and / or solid residues from the aqueous composition, such as filtration, e.g., using a filter press, or centrifugation, e.g., using a centrifuge.

[0039] Step ii) may include or be followed by a step ii') of washing said solids (and / or solid residues), preferably with water. Washing ii') is preferably carried out above the aqueous composition, and in particular above the soaking tank or vessel. This improves the process yield of recovered lithium salts. Alternatively, the washing step ii') may be carried out by injecting clean water during filtration, and in particular in the filter press. Step ii') can therefore be concurrent with step ii).

[0040] Indeed, at the end of step i), the aqueous composition includes insoluble solid particles and / or elements (referred to as solids and / or solid residues) in the aqueous composition (active material of the positive electrode, current collector, etc.). Step ii) then allows these solids to be removed.

[0041] Step ü) (and step ü') if it exists) thus makes it possible to obtain an aqueous composition free of solids, and to guarantee that all the residual lithium is present in said aqueous composition.

[0042] Step iii): addition of at least one acid or one of its precursors capable of forming at least one lithium salt insoluble in the aqueous composition

[0043] Step iii) consists of reacting the residual solid metallic lithium dissolved in the aqueous composition with said acid to form a lithium salt that is insoluble in the aqueous composition. This step iii) thus facilitates the subsequent step iv) of recovering the lithium salt.

[0044] Preferably, the acid or one of its precursors is chosen from mineral acids, such as phosphoric acid or carbonic acid, carboxylic acids, such as acetic acid, and one of their mixtures.

[0045] In step i), immersion of the assembly in the aqueous composition leads to the dissolution of the lithium and an increase in the pH of the aqueous composition (which may reach a pH greater than or equal to 13). In step iii), the pH of the aqueous composition decreases. Preferably, the acid or one of its precursors is added in sufficient quantities to precipitate all of the lithium present in the aqueous composition.

[0046] According to a preferred embodiment of the invention, the aqueous composition at the end of step iii) has a neutral pH, i.e., ranging from 6.5 to 7.5, and particularly preferably close to 7. This allows the aqueous composition to be reused for soaking a new set of cells. The aqueous composition can thus be used in a closed loop.

[0047] In step iii), the aqueous composition is analyzed, for example by ICP-AES, to measure the mass concentration of Li (in g / L). The mass concentration of Li in the aqueous composition is adjusted. It can range from 2 to 30 g / L (depending on the quantity of immersed cells), and preferably from 5 to 20 g / L.

[0048] The acid or its precursor is added to the aqueous composition at a rate of at least 10 g / L, and particularly preferably from 10 g / L to 500 g / L of aqueous composition (depending on the acid used).

[0049] Step iii) preferably lasts at least 10 minutes, and preferably from 10 to 60 minutes. The duration of step iii) will depend on the amount of residual lithium to be reacted with the acid or its precursor, the acid used, the volume of the aqueous composition and / or the temperature of the mixture.

[0050] The process may further include, during step iii), stirring the aqueous composition. This improves the formation kinetics of the lithium salts. Mechanical stirring may be used. The stirring means may be those described for step i).

[0051] The process may further include, during step i), heating the aqueous composition. This improves the formation kinetics of lithium salts and the salt recovery yield. Heating can be initiated before the addition of the acid or its precursor, i.e., before step i). Heating can be carried out using a reactor as described for step i) above. In particular, heating reduces the solubility of the Li salts in the aqueous composition and thus improves the recovery yield of dissolved Li.

[0052] The heating can be carried out at a temperature ranging from approximately 50°C to approximately 100°C, and preferably between 70°C and 90°C.

[0053] At the end of step iü), the aqueous composition comprises at least one lithium salt insoluble in that composition. In other words, the lithium salt is in solid form in the aqueous composition (i.e., as solid particles dispersed in the aqueous composition). The solid state can be detected visually or by a spectroscopic method such as UV-Visible light absorption.

[0054] Step iv): recovery of the lithium salt(s)

[0055] Step iv) can be carried out by filtration or centrifugation. At the end of step iv), the lithium salts are separated from the aqueous composition.

[0056] Step iv) can be implemented with one or more solid / liquid separation means, such as a filter press or a centrifuge.

[0057] Thanks to steps i), ii), iü) and iv), it is possible to recover the residual solid metallic lithium initially present in the cell set(s), in the form of salts. Furthermore, at the end of step iv), the lithium salt(s) are separated from the aqueous composition, which allows the aqueous composition to be reused in a new process for extracting residual solid metallic lithium, and in particular in a new step i).

[0058] Step v) of washing the lithium salts

[0059] The process may further include a step (v) of washing the lithium salt(s) obtained at the end of step (iv). The rinsing or washing may be carried out with water. The washing is preferably carried out above the aqueous composition, and in particular above the soaking tank or vessel. Alternatively, step (v) of washing may be carried out by injecting clean water during filtration, and in particular into the filter press. Step (v) particularly improves the purity of the lithium salts obtained.

[0060] Step vi) of drying lithium salts

[0061] The process may further include a step vi) of drying the lithium salt(s) obtained at the end of step iv) or v). The drying may be carried out at a temperature ranging from approximately 60°C to approximately 100°C. Step vi) may be carried out with one or more means of drying the lithium salts, such as an oven or a heating tunnel.

[0062] Steps a) and b) of cutting and grinding the cells before step i)

[0063] The process may further include, prior to step i), a step a) of cutting the entire cell assembly, and preferably all the cells in the assembly. This reduces the lithium dissolution time during step i). According to this embodiment, step i) is then carried out with a cut cell assembly or with one or more cut cells. Step a) can be carried out with one or more cutting means, such as a metal cutter, a laser cutting machine, or an ultrasonic cutting machine.

[0064] The process may further include, prior to step i), a step b) of grinding the entire cell assembly, and preferably all the cells in the assembly. This reduces the lithium dissolution time during step i). According to this embodiment, step i) is then carried out with a ground cell assembly or with one or more ground cells. Step b) can be carried out with one or more grinding means, such as a jaw crusher or a disc crusher. The grinding means can be equipped with a cooling system to prevent the material from heating up during grinding in order to reduce industrial risk.

[0065] Step b) is preferably carried out after step a). According to this embodiment, step i) is then carried out with a set of cell(s) cut and ground or with one or more cell(s) cut and ground.

[0066] Step c) of oxidation of residual lithium from the cells before step i)

[0067] The process may further include, before step i), a step c) of oxidation of the residual lithium as lithium oxide (Li2O). This prevents the generation of excessive hydrogen during step i). In particular, step c) reduces the reactivity of lithium before the implementation of step i), thus reducing industrial risk.

[0068] Step c) can be carried out by heating the entire cell assembly(ies), preferably to a temperature ranging from approximately 300°C to approximately 400°C. Step c) can be implemented with one or more heating means, such as an oven, a furnace, or a heating tunnel.

[0069] Step c) can last from about 30 minutes to about 2 hours.

[0070] Step c) can be carried out without prior steps a) and / b), or in association with steps a) and / or b). Preferably, step c) is carried out after a grinding step b), in particular in order to accelerate the oxidation kinetics of metallic lithium.

[0071] The process, and in particular steps i), ii), iii) and iv), can be repeated with other set(s) of cell(s), preferably with the aqueous composition from step iv) of the previous process. This allows it to be recycled.

[0072] Step d) of purifying the aqueous composition

[0073] The process may further include a step d) in which the aqueous composition containing dissolved lithium is purified. This makes it possible to remove all compounds soluble in the aqueous composition obtained from step ii) or ii'), except for lithium. These soluble compounds include the solid or quasi-solid electrolyte or its derivatives. In particular, at the end of step ii) or ii'), the solid or quasi-solid electrolyte is at least partially dissolved in the aqueous composition. The resulting aqueous composition comprises the solid electrolyte or one of its derivatives, and the residual lithium.

[0074] Step d) is preferably carried out by solid / liquid separation. Most preferably, step d) is carried out by hot filtration or hot centrifugation, and most preferably at a temperature ranging from approximately 70°C to approximately 90°C. During step d), the solid or quasi-solid electrolyte becomes insoluble in the aqueous composition when hot and can be easily separated by filtration from the lithium, which remains soluble in the aqueous composition. Step d) can be carried out with one or more solid / liquid separation methods, such as a filter press or a centrifuge.

[0075] Step d) makes it possible to avoid overconsumption of acid or one of its precursors during step iii), and also to improve the purity of the salts obtained in step iv).

[0076] 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 protrudes the negative electrode(s) of said cell(s) and a second border, opposite said first border, from which protrudes the positive electrode(s), 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, known as the processing temperature, greater than or equal to the melting temperature of said solid metallic lithium, said first extraction process leading to a set 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.

[0077] The first method according to A)

[0078] 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.

[0079] Each electrical energy storage cell preferably comprises: - a negative electrode containing solid metallic lithium, particularly 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.

[0080] 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.

[0081] The implemented assembly may comprise a single electrical energy storage cell or several electrical energy storage cells, preferably assembled, or in particular stacked, along an assembly direction. The assembly direction may be perpendicular to the plane formed by each electrical energy storage cell.

[0082] 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.

[0083] 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).

[0084] The first process according to A) allows the vast majority of the lithium to be extracted solid lithium is extracted from the entire cell(s) so as to leave only residual solid metallic lithium. The second process according to B) conforms to the first object of the invention and allows the extraction of all the residual solid metallic lithium.

[0085] 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 the said different melting points; and - preferably, the highest of the said different melting temperatures.

[0086] 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.

[0087] 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.

[0088] 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 assembly, and therefore the risk of fire during lithium recovery.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] Heating

[0093] Following a non-limiting example embodiment, the processing temperature is greater than or equal to 180.5°C.

[0094] According to one embodiment, the treatment temperature is less than or equal to a maximum temperature, for example 300°C.

[0095] Heating can be carried out using heating plates or a heating chamber.

[0096] Cut

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] The cutting step can be carried out by guillotine cutting.

[0103] In this case, the assembly is inserted into a cutter of suitable size and power.

[0104] 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.

[0105] The cutting step can be carried out before the positioning step, after the positioning step, or during the positioning step.

[0106] Electrical charging

[0107] 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.

[0108] 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 allows the lithium ions to move towards the negative electrode, thereby increasing the amount of lithium that can be recovered.

[0109] Each cell can be charged individually, or by electrically charging the entire set of cell(s).

[0110] Compression

[0111] According to a particularly advantageous embodiment, the extraction phase may further include a step of compressing the set of cell(s).

[0112] Thus, the molten lithium is forced to escape from each cell, thereby increasing the amount of lithium recovered.

[0113] 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.

[0114] 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).

[0115] 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.

[0116] 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.

[0117] 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).

[0118] 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).

[0119] 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.

[0120] Removal of connectors and overflows

[0121] Furthermore, the first process according to A) may include, prior to the extraction phase, A step involving the removal of at least one electrical connector from the cell assembly(ies), also known as "crimping". This facilitates the processing of the cell assembly(ies).

[0122] In addition, the first process according to A) may include, before the extraction phase, a step of removing material overflows at the level of at least one, and particularly each, border of the set of cell(s).

[0123] Positioning

[0124] 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).

[0125] 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.

[0126] 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.

[0127] Thus, the flow of molten lithium out of each cell, by gravity, is improved.

[0128] Furthermore, the risk of contact between the molten lithium and the positive electrode(s) is reduced, or even eliminated.

[0129] 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.

[0130] 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).

[0131] According to another embodiment of this first version, the heating step of the cell assembly(ies) can be carried out under vacuum.

[0132] 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.

[0133] According to a second version, the positioning step can perform a posi- The cell assembly is arranged in an orientation where the first edge of the cell assembly is above the second edge of the cell assembly. In this case, the extraction phase also includes, before the heating step, an immersion step of the cell assembly in a liquid, called the treatment liquid, which is denser than liquid lithium and electrically insulating.

[0134] 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 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.

[0135] In this application, "density" means the ratio of the mass density of the liquid in question to the mass density of water.

[0136] 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.

[0137] Thus, the flow of molten lithium out of each cell is improved by difference in density.

[0138] Furthermore, the risk of contact between the molten lithium and the positive electrodes is reduced, or even eliminated.

[0139] Preferably, the immersion step can be carried out by immersing the entire cell assembly(ies) completely in the treatment liquid.

[0140] The liquid may be a natural or synthetic oil, having the following physicochemical 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.

[0141] 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: - a soaking tank for the entire cell assembly in an aqueous composition; - one or more means of separating solids (and / or solid residues) from the aqueous composition; - a means of adding acid or one of its precursors to the aqueous composition; and - one or more means of solid / liquid separation for the recovery of the lithium salt(s).

[0142] The extraction unit conforming to the third object makes it possible to implement the process conforming to the first object of the invention.

[0143] The means for adding acid or one of its precursors to the aqueous composition can be a diaphragm metering pump. This allows a precise volume of the acid solution or its precursors, previously prepared in a tank, to be introduced, depending on the concentration of lithium present in the aqueous composition.

[0144] The solid / liquid separation means for the recovery of lithium salts can be as defined in the first object of the invention.

[0145] The residual lithium extraction unit may further include a heating means and / or a means for stirring the aqueous composition as defined in the first object of the invention.

[0146] The residual lithium extraction unit may further include a means for washing lithium salts and / or a means for washing the entire cell(s) to implement the washing steps described above of the process according to the first object of the invention.

[0147] The residual lithium extraction unit may further include one or more means for recovering the aqueous composition for reinjection into the soaking tank (in order to implement a new process in accordance with the first object of the invention). This thus makes it possible to recycle the aqueous composition in a closed loop.

[0148] 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.

[0149] The invention has as its 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 protrude the negative electrode(s) of said cell(s) and a second border, opposite said first border, and from which protrude 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.

[0150] 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.

[0151] 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.

[0152] For example, the cutting means may include a guillotine.

[0153] In particular, the heating means may include an oven (heating chamber) or heating plates.

[0154] 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.

[0155] Said lithium extraction unit may further include a means for compressing said assembly.

[0156] The compression means may include at least one roller.

[0157] 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).

[0158] Alternatively, the compression means may comprise two rollers between which the set of cell(s) is passed.

[0159] In general, the compression means can be configured to apply continuous compression throughout the extraction phase.

[0160] 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.

[0161] 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.

[0162] 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, to return to the second edge and begin a new pass.

[0163] 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.

[0164] 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. Description of figures and examples

[0165] Other advantages and features will become apparent upon examination of the detailed description of non-limiting embodiments and the accompanying drawings, in 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 embodiment of a process conforming to the second object of the invention.

[0166] 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.

[0167] In the figures, the elements common to several figures retain the same reference.

[0168] The process according to the first object of the invention, shown in [Fig. 1], comprises a first step (i) of immersing a set of cell(s) in an aqueous composition, preferably water. Each cell comprises residual solid metallic lithium, a positive electrode, a current collector associated with the positive electrode, and a solid or quasi-solid electrolyte. This step (i) dissolves the residual solid metallic lithium in the aqueous composition. Once dissolution is complete, a solid / liquid separation step (ii) is performed to separate the solids and solid residues from the aqueous composition. The solids and solid residues are, for example, removed or extracted from the aqueous composition. Step (ii) may also include a step (ii') of washing or rinsing said solids (or solid residues), preferably with water.Washing is preferably carried out above the aqueous composition, and in particular above the soaking tank. This improves the process yield in terms of recovered lithium salt(s). Once the solids and solid residues have been removed from the aqueous composition, an acid such as phosphoric acid or a CO2 stream (a precursor of carbonic acid) is added to the aqueous composition in step iii), so as to form one or more lithium salts insoluble in the aqueous composition. The following step iv) consists of recovering the lithium salts formed by solid / liquid separation, preferably by filtration.

[0169] The process according to the first object of the invention, shown in [Fig. 2], comprises the aforementioned steps i), ii), ii'), iii) and iv) as described above for [Fig. 1] and further comprises, prior to step i), any one of steps a), b), c) or a combination of at least two of steps a), b), c). These steps are 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 in step a) so as to obtain strips or pieces of cell(s) and to improve the dissolution of lithium in the aqueous composition in step i).Step a) can be followed by step b) in which the cut assembly is ground to obtain a ground cell assembly and further improve the dissolution of lithium in the aqueous composition during step i). Step b) can be followed by step c) of heating the assembly to oxidize the residual lithium. This step c) prevents the generation of an excessive amount of hydrogen during step i).

[0170] The process of [Fig. 2] then comprises step i) as described for [Fig. 1], followed by steps ii) of solid / liquid separation and ii') of washing as described for the [Fig.l].

[0171] The aqueous composition obtained at the end of steps ii) and ii') can be purified in a step d) so as to remove all compounds soluble in the aqueous composition, except for lithium. This step d) is preferably carried out by solid / liquid separation, and more particularly by hot filtration. During step d), the solid or quasi-solid electrolyte and / or its derivatives become insoluble in the hot aqueous composition and can be easily separated, by filtration, from the lithium which remains soluble in the aqueous composition.

[0172] The process of [Fig. 2] then comprises steps iii) and iv) as described for [Fig. 1], optionally followed by a step v) of washing the lithium salts. These may optionally be dried according to a step vi).

[0173] 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.

[0174] In a subsequent, optional step, excess material, and in particular solid metallic lithium, is removed from each lateral edge of the assembly.

[0175] Next, the process according to B) 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.

[0176] 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 assembly 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.

[0177] 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.

[0178] 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.

[0179] 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.

[0180] 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.

[0181] Example 1: Preparation of an electric battery comprising residual solid metallic lithium

[0182] A Lithium Metal Polymer (LMP®) battery cell was disassembled and removed. A Li extraction step by melting was then carried out according to the process described in document WO2023 / 036741 A2. The resulting lithium metal was weighed. In this example, 91% of the lithium metal initially present in the cell was extracted. Residual solid lithium metal remains trapped within the battery cell.

[0183] Example 2: extraction of residual lithium according to a process according to the invention

[0184] An all-solid-state lithium battery-type electrical storage cell 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 immersed in a soaking tank comprising water (as the aqueous composition), so as to cover said battery with water (approximately 18 L of water). After approximately 12 hours of immersion in the aqueous composition (water), the dissolution of the metallic lithium in the water is complete [step i)].

[0185] The water in the tank (soaking water or aqueous composition) was analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS) to measure the lithium concentration. The results obtained show that all of the residual Li was dissolved and recovered in the aqueous composition.

[0186] Step i) also leads to the delamination of the electrolyte, positive electrode and current collector films. These solids are removed from the tank [step ii)] and rinsed with approximately 2 L of water over the tank [step ii')].

[0187] Next, approximately 2.25 g of phosphoric acid (H3PO4 85%, Sigma Aldrich) were added with mechanical stirring to approximately 1 L of the aqueous composition prepared above, including the residual lithium and previously heated to 60°C [step iii)]. After 2 h of reaction, the aqueous composition was filtered to separate the Li salts from the aqueous composition [step iv)]. The resulting lithium salts were then dried at 100°C for 3 h [step vi)]. A white powder was thus obtained.

[0188] Example 3: Extraction of residual lithium according to a process according to the invention

[0189] Three all-solid-state lithium battery-type electrical storage cells containing residual lithium (approximately 10% by mass relative to the total mass of lithium present in the initial battery) were immersed in a soaking tank containing water (as an aqueous composition), so as to cover said battery with water (approximately 37 L of water). After approximately 20 hours of immersion in water, the dissolution of metallic lithium in the water is complete [step i)].

[0190] The aqueous composition was analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS) to measure the lithium concentration. The results obtained show that all of the residual Li was dissolved and recovered in the aqueous composition. The results also show that the amount of lithium dissolved in the aqueous composition is proportional to the number of cells immersed in the aqueous composition.

[0191] Step i) also leads to the delamination of the electrolyte, positive electrode and current collector films. The solids are removed from the tank [step ii)] and rinsed with approximately 3 L of water over the tank [step ii')].

[0192] The resulting aqueous composition is heated to 95°C for Ih so that the electrolyte or its polymer components become insoluble. The resulting composition is filtered to obtain a purified aqueous composition [step d)].

[0193] Next, approximately 9 g of phosphoric acid (H3PO4 85%, Sigma Aldrich) were added under mechanical stirring to approximately 1 L of the aqueous composition as prepared above, including the residual lithium and previously heated to 60°C [step iii)]. After 2 h of reaction, the aqueous composition was filtered to separate the Li salts from the aqueous composition [step iv)]. The lithium salts obtained were then dried at 100°C for 3 h [step vi)]. A white powder was thus obtained.

[0194] X-ray diffraction (XRD) analyses performed on a sample of the white powder obtained show diffraction peaks corresponding to the Li3PO4 phase. No other crystallographic phase could be observed. This result indicates the formation of a product composed mainly of Li3PO4.

[0195] The aqueous composition remaining after step iv) has a pH of 7.6. It can therefore be reused in a new process according to the invention as the aqueous composition implemented in step i).

[0196] The solid residues recovered at the end of step ii') are ground and analyzed by X-ray diffraction (XRD). The analysis results showed that the solids are composed only of LiFePO4, which is used as the active material for the positive electrode, and aluminum, which is used as the current collector. This result confirms that the solids separated from the aqueous composition at the end of step ii') are free of metallic lithium or its derivatives, such as lithium hydroxide, LiOH.

[0197] Example 4: Extraction of residual lithium according to a process according to the invention

[0198] Example 2 was reproduced using a CO2 stream in the aqueous composition instead of phosphoric acid. The passage of the CO2 stream through the aqueous composition leads to the formation of carbonic acid H2CO3 and the precipitation of Li2CO3 salts. The Li2CO3 recovery yield is improved by heating the solution before CO2 injection due to the lower solubility of Li2CO3 in hot water.

[0199] The CO2 flow is maintained until an aqueous composition with a pH of 7 is obtained.

[0200] Example 5: extraction of residual lithium according to a process according to the invention

[0201] Example 2 was reproduced by carrying out a cutting step [step a)] prior to step i).

[0202] To do this, the cell was cut lengthwise into 5 strips. The 5 strips were then placed in a tank containing approximately 18 L of water (as aqueous composition) [step i)]. After only 2 hours, the dissolution of metallic lithium was The process is complete and the films are fully delaminated. The other steps are identical to those described in example 2.

[0203] Cutting the cell reduces the dissolution time of residual Li.

[0204] Of course, the number of straps is only an indicative example, the time to dis The solution was improved regardless of the number of strips. It is also possible to cut the cell(s) into other shapes (e.g., into pieces).

[0205] Example 6: extraction of residual lithium according to a process according to the invention

[0206] The solids obtained in Example 3 containing LiFePO4 and aluminium were Used: Approximately 700 g of the solids were first ground using a Shini SG-1628N (2.2 kW) knife mill equipped with a 160 x 280 mm cutting chamber with two fixed blades and three sets of four offset moving blades. Using a sizing screen, the final particle size was between 5 mm and 10 mm. The resulting powder was then passed through an ECS-40 eddy current separator. Two fractions were obtained: one rich in aluminum and the other containing mainly active material, also called Black Mass. The process according to the invention allows for the complete recycling of lithium, active material, current collector metal, and the aqueous composition used in step i).

Claims

Claims

1. 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) immersing said assembly in an aqueous composition, ii) separating the solids from the aqueous composition, iii) adding at least one acid or one of its precursors capable of forming at least one lithium salt insoluble in the aqueous composition, and iv) recovering the lithium salt.

2. Method according to claim 1, characterized in that the aqueous composition comprises at least 90% by mass of water, relative to the total mass of aqueous composition.

3. Method according to claim 1 or 2, characterized in that the acid or one of its precursors is chosen from mineral acids, carboxylic acids, and one of their mixtures.

4. Method according to any one of the preceding claims, characterized in that the acid or one of its precursors is added to the aqueous composition at a rate of at least 10 g / L of aqueous composition.

5. Process according to any one of the preceding claims, characterized in that the aqueous composition at the end of step iii) has a neutral pH.

6. Method according to any one of the preceding claims, characterized in that step ii) comprises or is followed by a step ii') of washing said solids.

7. Method according to any one of the preceding claims, characterized in that it further comprises, before step i), a step a) of cutting the set of cell(s).

8. Method according to any one of the preceding claims, characterized in that it further comprises, before step i), a step b) of grinding the set of cell(s).

9. Method according to any one of the preceding claims, characterized in that it further comprises, before step i), a step c) of oxidation of the residual lithium to lithium oxide.

10. Method according to any one of the preceding claims, characterized in that it further comprises a step d) during which the aqueous composition comprising dissolved lithium is purified.

11. A method for the complete extraction of lithium from a set of electrical energy storage cells comprising solid metallic lithium, said method comprising: A) a first method for extracting lithium from a set of electrical energy storage cells, 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 set of cells comprising a first edge from which the negative electrode(s) of said cell(s) protrude and a second edge, opposite said first edge, and from which the positive electrode(s) protrude,said method comprising an extraction phase comprising 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, called treatment temperature, greater than or equal to the melting temperature of said solid metallic lithium, said first extraction method leading to a set of electrical energy storage cell(s) comprising residual solid metallic lithium, and B) a second method for extracting residual lithium as defined in any one of the preceding claims.,

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

13. Unit for extracting residual lithium from a set of electrical energy storage cells comprising residual solid metallic lithium, characterized in that it comprises: - a tank for soaking the set of cells in an aqueous composition; - one or more means for separating the solids from the aqueous composition; - a means for adding acid or one of its precursors to the composition aqueous; and - one or more means of solid / liquid separation for the recovery of the lithium salt(s).

14. 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 edge from which the negative electrode(s) of said cell(s) protrude and a second edge, opposite said first edge, and from which the positive electrode(s) protrude, 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: - means for 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 - a heating means configured to heat said assembly to a temperature, called treatment temperature, greater than or equal to the melting temperature of said solid metallic lithium, and * a residual lithium extraction unit as defined in claim 13.