Method for safely extracting lithium from electric batteries containing solid metallic lithium

Abstract

The invention relates to a method (300) for extracting lithium from a battery comprising at least two cells, each cell comprising a negative electrode (102), a positive electrode (104; 108) and solid or quasi-solid metallic lithium (106), the cells having a first edge from which the negative electrode protrudes and a second edge opposite to the first edge from which the positive electrode protrudes, the method (300) comprising an extraction phase (306) comprising the steps of: placing the battery in an orientation in which one of the first and second edges is below the other of the first and second edges (308); heating the battery to a temperature, called the treatment temperature, which is equal to or higher than the melting temperature of the solid metallic lithium (310); characterized in that the method (300) further comprises a step (314) of breaking the electrical connection between the positive electrodes of at least two of the cells of the battery, in particular of all the cells. The invention further relates to a plant for carrying out such a method.

Description

[Technical field]

[0001] The present invention relates to a method for safely extracting lithium from batteries containing solid lithium metal.

[0002] The field of the invention is that of solid-state lithium metal based batteries, in particular lithium metal polymer batteries, and even more particularly the recycling of these batteries. [Background technology]

[0003] Batteries based on solid or quasi-solid lithium metal are well known, such as lithium metal polymer batteries (LMP®). These batteries are increasingly being used, for example in electric vehicles or power stations. Thus, the number of batteries based on solid or quasi-solid lithium metal has been constantly increasing for several years.

[0004] Such batteries do not have an infinite service life and must be recycled, however, at the end of their life they still have considerable value as they contain solid lithium metal that can be reused in other batteries or other applications.

[0005] There are currently only a few techniques for recovering solid lithium metal from batteries. These techniques involve heating the battery to temperatures above the melting temperature of solid lithium metal in order to recover the liquid lithium. However, these techniques pose a fire hazard to the battery. One object of the present invention is to remedy the above mentioned drawbacks.

[0006] Another object of the present invention is to propose a method for efficient recovery of solid or quasi-solid lithium metal from batteries for all configurations of electrical energy storage cells in which the cathode and electrolyte are stable up to at least 181° C. (or up to the melting temperature of lithium) by limiting and controlling the impact of possible short circuits on lithium recovery. Summary of the Invention

[0007] [Disclosure of the Invention] The present invention achieves at least one of the above objects by providing a battery, such as a solid-state or quasi-solid-state lithium electrolyte battery, comprising at least two electrical energy storage cells; Each cell comprises a positive electrode, a negative electrode, and solid or quasi-solid lithium metal; a first edge from which a negative electrode of said cell protrudes, and a second edge opposite said first edge from which a positive electrode protrudes. 1. A method for extracting lithium from That is: - placing the battery in an orientation such that one of the first and second edges is below the other of the first and second edges; - heating the battery to a temperature, called the processing temperature, which is equal to or greater than the melting temperature of the solid lithium metal; In the above-mentioned method, comprising an extraction step comprising: a method comprising the further step of disconnecting the electrical connection between the positive electrodes of at least two, and in particular all, of the cells of the battery. This can be achieved by:

[0008] Therefore, the present invention proposes to recover solid lithium metal from the battery by heating the battery to a processing temperature above the melting temperature of solid lithium metal. Once the lithium metal has melted, all or part of the lithium metal will naturally flow out of each cell. Thus, the present invention allows for a simple and straightforward recovery of solid lithium metal.

[0009] Furthermore, the present invention proposes a specific orientation for each cell, in which the cell is at least tilted, which orientation of each cell facilitates the outflow of molten lithium from the cell by gravity.

[0010] Moreover, and above all, the invention provides a step of disconnecting the connection between the positive poles of at least two of the battery cells, and preferentially all of the cells. In other words, the disconnecting step makes it possible to interrupt the electrical connection between the positive poles of the battery cells. Thus, after the disconnecting step, the battery comprises a number of cells that are no longer electrically connected to each other, thereby reducing the reactivity of the battery, and therefore the risk of the battery catching fire when recovering the lithium.

[0011] The first edge can be characterized by the fact that it defines the side to which lithium must flow when it reaches a liquid state. In this application, an “electrical energy storage cell” or “cell” refers to an electrical energy storage cell that comprises at least: - an anode formed by or including a solid lithium metal layer; - Positive electrode, a solid electrolyte, in particular comprising a lithium salt, arranged between the positive and negative electrodes; and - Positive electrode current collector It is understood to mean an assembly comprising: In this application, "solid or quasi-solid lithium metal" refers to -pure lithium metal; or - at least one combination of lithium metal alloys; or - combination of pure lithium metal and at least one lithium metal alloy may include.

[0012] When "solid or quasi-solid lithium metal" includes a combination of different forms of lithium having different melting temperatures, such as those described above, the heating step may convert the battery into - the lowest of said different melting temperatures; and - preferentially the highest of said different melting temperatures The mixture is heated to a processing temperature greater than or equal to the processing temperature. According to one non-limiting embodiment, the treatment temperature is 180.5° C. or higher. According to one embodiment, the processing temperature is up to a maximum temperature of, for example, 300°C. A battery can include two or more cells.

[0013] A battery may comprise several assembled, or in particular stacked, cells along an assembly direction that may be perpendicular to the plane formed by each cell. In particular, the battery may correspond to a battery in which the cells are connected in series.

[0014] According to one embodiment, the cutting step can cut the connection wire between the positive electrodes along a cutting line on the side of said electrical connection wire at the position of the second edge, in particular at the position immediately adjacent to the second edge.

[0015] This embodiment allows the solid lithium metal to be retained within the battery or prevented from being expelled from the battery when the electrical connection is broken, thereby allowing for improved lithium recovery. In this embodiment, the connecting wire should be cut close enough to the second edge so that there is no contact between the different positive poles after cutting.

[0016] According to another embodiment, the cutting step can cut the cell along a cutting line on the side of said cell at the location of the second edge, in particular at the location immediately adjacent to the second edge. In this embodiment, the cut should be very close to the second edge to reduce the amount of lithium lost.

[0017] For example, the cut may be made at a distance "d" from the second edge that is 2 mm or less, or 1% or less of the cell size between the first and second edges of the battery. The cutting step may be performed by a guillotine cut. In this case, the battery is inserted into a guillotine cutter of appropriate size and power. According to an embodiment, the cutting step may be performed before the heating step begins.

[0018] According to an embodiment, the cutting step can be performed after the heating step has begun, in which case, preferentially, the cutting step can be performed before the solid lithium metal starts to melt. According to an embodiment, the cutting step may be performed before the placing step. According to an embodiment, the cutting step may be performed after the placing step. According to an embodiment, the cutting step may be performed during the placing step.

[0019] According to a particularly advantageous feature, it is possible that the method according to the invention further comprises, before the extraction step, a step of charging the battery, said extraction step being applied to said charged battery.

[0020] It is possible to increase the lithium extraction yield by charging the battery and performing an extraction step on the charged cell: in fact, charging the cell makes it possible to increase the amount of recoverable lithium by moving lithium ions towards the negative electrode. Each cell may be charged individually or by charging the battery. According to a particularly advantageous embodiment, the extraction step may further comprise a step of compressing the battery. As a result, the molten lithium is forced to flow out of each cell, thereby increasing the amount of lithium recovered.

[0021] The compression step may be performed continuously throughout the extraction phase, in which case each cell is partially or fully compressed throughout the entire extraction phase.

[0022] Alternatively, the compression step may be performed once or multiple times separately during the extraction phase, in which case the extraction phase includes moments when the battery is not compressed.

[0023] Advantageously, the pressing step can apply pressure to the surface of the battery by sweeping the surface from the second edge towards the first edge, so that the molten lithium is gradually moved / guided towards the first edge from which the negative electrode protrudes, thereby increasing the amount of lithium recovered and reducing the risk of contact between the lithium and the positive electrode. For example, the compressing step may be performed by passing the battery between two rollers. According to another example, the compressing step may be performed by a compression roller that presses the battery against a support surface. Compression can be applied in successive passes, one at a time sweeping the surface of the battery starting at the second edge toward the first edge.

[0024] The space between the compression rollers and between the compression roller and the bearing surface may correspond to the thickness of the battery minus the thickness of the layer of solid lithium metal, allowing compression to be applied while solid lithium is still present within the battery.

[0025] The spaces between the two compression rollers and between the compression roller and the bearing surface respectively can be reduced with each successive pass so that compression is always applied against the battery. The speed at which the battery passes between and between each of the compression rollers, or more generally the sweep speed, may be from a few mm to tens of mm per second.

[0026] Furthermore, the method according to the invention may include the step of removing at least one electrical connector, also called a "crimp", from the battery prior to the extraction step. This makes the battery easier to dispose of.

[0027] Furthermore, the method according to the invention may comprise, prior to the extraction step, a step of removing any overhanging material at least at one edge, and in particular at each edge, of the battery. According to a first variation, the placing step can place the battery in an orientation such that a first edge of the battery is below a second edge of the battery.

[0028] Such an orientation of the battery, and therefore of each battery cell, makes it possible, on the one hand, to facilitate the outflow of the molten lithium from the cell by gravity, and, on the other hand, to avoid contact between the molten lithium and the positive electrode or the positive electrode current collector (such contact may cause an electrical short circuit or an electric arc, and such a short circuit may be the cause of a fire). According to a preferred embodiment of this first variant, the positioning step may position the battery vertically with the first edge facing downwards.

[0029] Thus, the flow of molten lithium from each cell is facilitated by gravity. In addition, the risk of contact between the molten lithium and the positive electrode is reduced or even eliminated. Preferably, in this first variant, the step of heating the battery is carried out in an inert gas. In that way, the method according to the invention reduces the risk of accidents, in particular the risk of fire.

[0030] In addition, the method according to the invention makes it possible to avoid the formation of contaminants that may be produced by undesired, even uncontrolled, physicochemical reactions during lithium extraction.

[0031] According to non-limiting embodiments, the inert gas may be or may include any one of the following gases: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). According to another embodiment of this first variant, the step of heating the battery may be carried out under vacuum.

[0032] According to a second variant, the positioning step can place the battery in an orientation in which a first edge of the battery is above a second edge of the battery, in which case the extraction stage further comprises, prior to the heating step, immersing the battery in a liquid, called a treatment liquid, that is denser and more electrically insulating than liquid lithium.

[0033] This second variant presents a specific orientation of each cell, in which it is at least tilted so that a first edge from which the negative electrode protrudes is above the height of a second edge opposite the first edge from which the positive electrode protrudes. Such an orientation of each cell makes it possible, on the one hand, to promote the flow of molten lithium out of the cell due to density differences, and, on the other hand, to avoid contact between the molten lithium and the positive electrode or the positive electrode current collector, which may cause an electrical short circuit, which may cause a fire. In addition, the immersion of the cells in a liquid makes it possible to enhance the dissipation of thermal energy from the cells, especially in the event of a short circuit, and thus to significantly limit the effects of a short circuit.

[0034] In this application, "density" refers to the ratio between the density of the liquid of interest and the density of water. According to a preferred embodiment of this second variant, the positioning step may position the battery vertically with the second edge facing downwards. As a result, the outflow of molten lithium from each cell due to density differences is accelerated. In addition, the risk of contact between the molten lithium and the positive electrode is reduced or even eliminated. Preferably, the soaking step is carried out by completely immersing the battery in the treatment solution.

[0035] The treatment solution has the following physicochemical properties: - being hydrophobic and non-reactive towards lithium; - be electrically insulating; - It is denser than lithium, - Thermally stable even above the melting temperature of lithium, which is 180.5°C; - the highest possible flash point and autoignition point The oil may be a natural or synthetic oil comprising:

[0036] According to another aspect of the invention, there is provided a solid-state or quasi-solid-state lithium electrolyte battery comprising at least two electrical energy storage cells; Each cell comprises a positive electrode, a negative electrode, and solid or quasi-solid lithium metal; a first edge from which a negative electrode of said cell protrudes, and a second edge opposite said first edge from which a positive electrode protrudes. 1. An installation for extracting lithium from - means for positioning the battery in an orientation in which one of the first and second edges is below the other of the first and second edges; heating means configured to heat said battery to a temperature, called the processing temperature, which is equal to or greater than the melting temperature of said solid lithium metal; In the said facility comprising: It is proposed that the installation further comprises means for disconnecting the electrical connection between the positive poles of at least two of the cells of the battery, in particular all of the cells.

[0037] In general, the equipment may comprise means configured to implement any combination of at least one of the features described above and which for the sake of brevity will not be repeated in detail here. For example, the cutting means may include a guillotine cutter. In particular, the heating means may comprise an oven.

[0038] Advantageously, the oven is filled with an inert gas or is under vacuum, or even filled with a processing liquid that is denser than liquid lithium. The installation according to the invention may further comprise means for compressing the battery. The compression means may include at least one roller.

[0039] In particular, the pressing means may include a single roller which presses the battery against the bearing surface, which may be heated to accelerate the temperature rise of the battery. Alternatively, the compression means may include two rollers between which the battery passes. Generally, the compression means may be configured to apply continuous compression throughout the extraction stage.

[0040] Alternatively, the compression means may be configured to apply one or multiple discrete compressions during the extraction phase, in which case the extraction phase includes moments when the battery is not compressed.

[0041] Advantageously, the compression means can be configured to apply a constant or variable compression, either incrementally or by sweeping over the battery surface, from the second edge to the first edge, so that the molten lithium is gradually moved / guided towards the lower first edge, thereby increasing the amount of lithium recovered and reducing the risk of contact between the lithium and the positive electrode.

[0042] When one or two compression rollers are used, compression can be applied to the battery in successive passes, each pass being applied by sweeping the surface of the battery from the second edge to the first edge, and at the end of each pass compression can be stopped by pulling the rollers apart or away from the support surface to return to the second edge to begin a new pass. The distance between the rollers and between the compression roller and the bearing surface, respectively, can be reduced with each pass, in particular between two successive passes.

[0043] The invention can be implemented to process several batteries, in particular several batteries forming a battery pack and connected in parallel within said battery pack.

[0044] At least two batteries can be aligned side-by-side, for example in a direction parallel to the first edge, without overlapping. In this case, pressure can be applied to the at least two batteries by the same pressure means, ie a set of rollers or rollers interacting with a bearing surface.

[0045] [Description of the drawings and embodiments] Other advantages and features will become apparent upon examination of the detailed description of the entirely non-limiting embodiments and from the accompanying drawings, in which: [Brief description of the drawings]

[0046] [Figure 1] 1 is a schematic diagram showing a non-limiting exemplary embodiment of a cell in the sense of the present invention; [Diagram 2] 1 is a schematic diagram showing a non-limiting exemplary embodiment of a battery in the sense of the present invention; [Diagram 3] FIG. 1 is a schematic diagram illustrating a first non-limiting exemplary embodiment of a method according to the present invention. [Figure 4] FIG. 3 is a schematic diagram illustrating a second non-limiting exemplary embodiment of the method according to the present invention. [Diagram 5] FIG. 4 is a schematic diagram illustrating a third non-limiting exemplary embodiment of the method according to the present invention. [Figure 6] 1 is a schematic diagram showing a first non-limiting exemplary embodiment of an installation according to the invention; [Figure 7] Schematic diagram of a second non-limiting exemplary embodiment of an installation according to the invention. [Figure 8a] 1 is a schematic diagram showing an example of breaking an electrical connection between positive electrodes of battery cells that can be performed in the present invention. [Figure 8b] 1 is a schematic diagram showing an example of breaking an electrical connection between positive electrodes of battery cells that can be performed in the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] It is clearly understood that the embodiments described below are in no way limiting. In particular, if a feature is selected from the features disclosed below separately from the other features disclosed, and this selection of feature is sufficient to provide a technical advantage or to differentiate the invention from the prior art, it is possible to envisage a variant of the invention comprising only this selected feature. This selection includes at least one preferably functional feature, lacking structural details or having only a part of a structural detail, if this part alone provides a technical advantage or is sufficient to differentiate the invention from the prior art.

[0048] In the drawings, the same reference numbers are used for features that are common to several drawings. FIG. 1 is a schematic diagram of a non-limiting exemplary embodiment of a cell in the sense of the present invention. The cell 100 shown in FIG. 1 includes a negative electrode 102 formed of or including a layer of solid lithium metal. The cell 100 further comprises a positive electrode 104 . The solid electrolyte layer 106 is disposed between the negative electrode 102 and the positive electrode 104. The solid electrolyte layer 106 may include, for example, a lithium salt.

[0049] The positive electrode 104 is typically formed by a composite layer of polymer and active material. The cell 100 may further include a current collector 108 on either side of the positive electrode 104 and forming part of or associated with the positive electrode 104. The current collector 108 is typically made of aluminum.

[0050] Conventionally, the negative electrode 102 of the cell 100 protrudes beyond the other elements of the cell 100 at a first edge 110 of the cell 100, here to the right in the figure. The positive electrode 104 with the current collector 108 protrudes beyond the other elements of the cell 100 at a second edge 112 opposite the first edge 110. In the illustrated example, only the current collector 108 protrudes beyond the second edge 112, here to the left in the figure. In other examples, it is conceivable that the protruding part is only the positive electrode 104, or even the positive electrode 104 and the current collector 108.

[0051] Of course, the cell 100 shown in Fig. 1 is a very simplified embodiment provided for non-limiting illustration: a cell in the sense of the present invention may contain other layers than those shown, or more layers, or layers whose composition differs from the composition shown here as a non-limiting example.

[0052] FIG. 2 is a schematic diagram illustrating a non-limiting exemplary embodiment of a battery including several cells. The battery 200 shown in FIG. i Several identical cells 1001-100 are assembled in a direction 202 perpendicular to the plane of the layers of the n It is equipped with: Each cell 100 i may be identical to cell 100 in FIG.

[0053] Battery 200 consists of all cells 1001 to 100 nThe battery 200 includes a pair of wires / tracks / connecting lines 202 that connect the positive poles of the battery 200 together. These connecting lines 202 are connected to a connector 204 on the battery 200 that forms the positive terminal of the battery 200. This connector 204 is also called a "crimp."

[0054] Battery 200 consists of all cells 1001 to 100 n The negative poles of the batteries 200 are provided with wires / tracks / connecting lines (not shown) for connecting them together. These connecting lines are connected to a connector (not shown) of the battery 200 which forms the negative terminal of the battery 200.

[0055] FIG. 3 is a schematic diagram of a non-limiting exemplary embodiment of a method according to the invention. The method 300 shown in FIG. 3 includes a first optional step 302 in which the battery's electrical connectors, specifically the concentrators, also called "crimps," are removed. In optional step 304, all overhanging material on either edge of the battery is removed, particularly solid lithium metal. Next, the method 300 includes a step 306 for extracting lithium metal from the battery cell.

[0056] The extraction phase 306 includes a step 308 of placing the battery in an orientation in which a first edge from which the negative electrode protrudes is at a lower height than a second edge from which the positive electrode and / or current collector protrudes. In particular, step 308 places the battery in a vertical orientation, i.e., parallel to the gravity vector, with the first edge from which the negative electrode protrudes facing downwards. Preferably, but by no means limiting, the battery is maintained in this orientation throughout the extraction phase 306.

[0057] The extraction step 306 further includes heating 310 the battery to a processing temperature above the melting temperature of the solid lithium metal present in the battery, for example 180.5° C. This temperature causes the solid lithium metal to melt and flow naturally under the influence of gravity so that it can be extracted from each cell. Preferably, but by no means limited to, the battery is maintained at this temperature throughout the extraction step 306. Advantageously, the heating step is carried out in a closed chamber filled with an inert gas.

[0058] The extraction stage 306 may further include an optional step 312 of compressing the battery to expel the molten lithium from each cell of the battery. Compression may be performed continuously throughout or part of the extraction stage 306. Alternatively, the compression step 312 may be repeated several times separately during the extraction stage 306. Preferably, the compression step 312 applies compression to the surface of the battery in a gradual or sweeping manner starting from the second edge where the positive electrode protrudes toward the first edge where the negative electrode protrudes.

[0059] Among other things, the method 300 comprises a step 314 of severing the electrical connection between the positive electrodes / current collectors of at least two of the battery cells, in particular all of the cells. Such a severing step 314 makes it possible to reduce the reactivity of the battery by severing the electrical connection between the positive electrodes of the battery cells, thus reducing the risk of the battery ignition during the extraction phase and thus making the recovery of solid lithium metal more reliable and less dangerous.

[0060] In the illustrated example, the step of severing the electrical connection 314 occurs before the extraction step 306. Alternatively, the step of severing the electrical connection 314 can occur during the extraction step 306, before, during, or after the positioning step 308, or before, during, or after the heating step 310. A further non-limiting exemplary embodiment of a step of severing the electrical connection between the positive electrodes of the cells that can be performed in accordance with the present invention is shown in relation to Figures 8a and 8b.

[0061] FIG. 4 is a schematic diagram of another non-limiting exemplary embodiment of a method according to the present invention. The method 400 shown in FIG. 4, similar to the method 300 of FIG. 3, includes the optional step 302 of removing the electrical connectors of the battery and the optional step 304 of removing the solid lithium metal overhanging at each edge of the battery. The method 400 next includes the step 314 of disconnecting the electrical connection between the positive terminals of the battery cells.

[0062] The method 400 then includes extracting 406 lithium metal from the cell. The extraction phase 406 includes a step 408 of placing the battery in an orientation in which the first edge 110 from which the negative electrode 102 protrudes is vertically higher than the second edge 112 from which the positive electrode 104 and current collector protrude. In particular, step 408 places the battery in a vertical orientation, i.e., parallel to the gravity vector, with the first edge 110 from which the negative electrode protrudes facing up. Preferably, but by no means limiting, the battery is maintained in this orientation throughout the entire extraction phase 406.

[0063] The extraction stage 406 includes immersing the battery in a neutral treatment liquid 410 that is denser than liquid lithium. For example, the treatment liquid may have the following physicochemical properties: - being hydrophobic and non-reactive towards lithium; - be electrically insulating; - Higher density than lithium, - thermal stability above the melting temperature of lithium, which is 180.5°C; and - flash and auto-ignition points as high as possible, e.g. above 600°C and at least above the processing temperature of the cell The oil may be a natural or synthetic oil, such as paraffin oil, having The immersion step 410 is performed by immersing the battery in the treatment solution such that the treatment solution completely covers the battery.

[0064] This immersion step 410 is particularly advantageous because it promotes significant heat exchange between the battery and the treatment solution, thereby limiting the risk of overheating the battery and the risk of thermal energy release generated in the event of a short circuit, and improving the heating reaction rate. The extraction stage 406 may further include the heating step 310 described above, and optionally the pressing step 312 described above.

[0065] During the heating step, the treatment temperature must not exceed the degradation temperature of the treatment liquid, above which the treatment liquid will degrade. In other words, the treatment liquid will change its properties by exceeding a threshold temperature such that the above-mentioned properties are no longer fulfilled. Ideally, the degradation temperature of the treatment liquid should be higher than +40°C compared to the melting temperature of lithium, and for example be between +20°C and +60°C.

[0066] FIG. 5 is a schematic diagram of another non-limiting exemplary embodiment of a method according to the present invention. The method 500 shown in FIG. 5 includes all of the steps of the method 300 of FIG. 3 and the method 400 of FIG. Method 500 further includes a step 502 of recharging at least one cell of the battery prior to each of the steps of methods 300 and 400. The at least one cell is partially or fully recharged. Charging the cell allows for increased amounts of lithium to be extracted as recharging causes migration of lithium ions toward the negative electrode of the cell.

[0067] FIG. 6 is a schematic diagram of a non-limiting exemplary embodiment of an installation according to the invention. The installation 600 shown in FIG. 6 can be used to carry out the methods according to the invention, in particular the methods 300 and 500 of FIGS.

[0068] System 600 allows for the extraction and recovery of some or all of the lithium from the cells of a battery that includes solid lithium metal, such as battery 200 of FIG.

[0069] The equipment 600 includes an oven 602, filled with inert gas or under vacuum, configured to heat the battery to a processing temperature above the melting temperature of the solid lithium metal present in the cells, e.g., 180.5°C or 181°C.

[0070] The fixture 600 includes a pair of clamps 604 for holding the battery 200 in a vertical or at least inclined position in which the first edge 110 is disposed below the level of the second edge 112. Each of the clamps 604 is movably mounted to a vertical rail 606 for moving the battery 200 vertically.

[0071] The fixture 600 further includes a pair of rollers 608 having a gap therebetween that corresponds to the thickness of the battery 200 minus the thickness of the solid layer of lithium metal. The pair of rollers 608 are positioned such that when the clamp 604 is moved upward, the battery 200 passes between the rollers 608, starting with the second edge 112, such that the rollers apply pressure to the battery 200 starting from the second edge 112 and gradually moving toward the first edge 110.

[0072] The equipment further includes a receiver 610 for collecting the molten lithium metal that flows out of each cell under the influence of gravity. The receiver 610 must be inert to lithium. Advantageously, the installation 600 further comprises means 612 for breaking the electrical connection between the positive poles of the batteries.

[0073] In the illustrated embodiment, the cutting means 612 is disposed within the oven 602. Alternatively, the cutting means 612 may be disposed outside the oven 602. For example, the cutting means 612 can be disposed above the oven 602, to the side of the oven, or at a distance from the oven 602.

[0074] In the illustrated embodiment, the cutting means 612 is a guillotine cutter designed to sever an electrical connection. The battery 200 is positioned such that the second edge side of the battery is between the jaws of a guillotine cutter, for example by a clamp 604. The guillotine cutter 612 is then actuated to sever the electrical connection between the positive poles of the battery cells. Alternatively, the cutting means 612 may be a shear, a disc grinder, a laser cutting means, or more generally any suitable cutting means.

[0075] FIG. 7 is a schematic diagram of another non-limiting exemplary embodiment of an installation according to the invention. The installation 700 shown in FIG. 7 can be used to carry out any method according to the invention, in particular the methods 400 and 500 of FIGS. Facility 700 includes all of the elements of facility 600 of FIG. 6, except for the differences noted below.

[0076] In the arrangement 700, the clamps 604 are configured to orient the battery 200 in an inclined position, and preferentially vertically, with the first edge 110 of the battery 200 above the second edge 112. In addition, the oven 602 does not include a collection pan 610 .

[0077] Additionally, a pair of rollers 608 are positioned above the battery 200 to apply pressure from the second edge 112 of the battery 200 to the first edge 110 of the battery 200 .

[0078] Additionally, the oven 602 is filled with a processing liquid 702 that completely covers the battery 200. The processing liquid 702 is electrically insulating and inert to lithium, and in particular has a higher density than the molten lithium. This processing liquid 702, being denser than lithium, allows the molten lithium to be directed toward the first edge 110 so that it leaves the battery and is located at the surface of the processing liquid 702 where it can be collected. In the present invention, the electrical connection between the positive electrodes of the battery cells can be broken in a variety of ways.

[0079] FIG. 8a shows a first exemplary embodiment of how the electrical connection between the positive poles of a battery can be broken according to the present invention.

[0080] In the illustrated embodiment, the disconnection is performed on cells 1001-100 of the battery 200. n The cutting is performed along the second edge 112 of the battery, specifically along the cutting line 802 which is located very close to the second edge 112. In other words, in this embodiment, the cells forming the battery are cut at the second edge of the battery. To reduce the amount of lithium lost, the cut may be made very close to the second edge 112. For example, the cut can be made no more than 2 mm from the second edge 112, or no more than 1% of the cell size between the first edge 110 and the second edge 112 of the battery 200.

[0081] FIG. 8b provides another exemplary embodiment of how the electrical connection between the positive poles of a battery can be severed in accordance with the present invention.

[0082] In the illustrated embodiment, the cut is made at the second edge 112, on the side of the electrical connection wire 202, and in particular along a cut line 804 which is located immediately adjacent to the second edge 112. In other words, in this embodiment, the cells forming the battery are not cut.

[0083] This exemplary embodiment allows solid lithium metal to be retained within the battery when the electrical connection between the positive electrodes of the cells is broken, or not removed from the battery, thereby allowing for improved lithium recovery.

[0084] In this exemplary embodiment, the connecting wire 202 must be cut close enough to the second edge 112 so that after cutting there is no longer any contact between the positive poles. Of course, the invention is not limited to the embodiments detailed above. For example, the composition of each cell may differ from that shown in FIG.

[0085] In addition, the apparatus according to the invention may comprise devices other than those shown in Figures 6 or 7, such as means for cutting the electrical connectors of the battery, means for cutting the overhanging portion of one or each of the edges, etc.

[0086] As an alternative to what has been described, the clamp 604 may be fixed and movable as may the roller 608 and guillotine cutter 612, respectively.

[0087] In addition, the present invention is not limited to the above-mentioned embodiments, and can be applied to solid or quasi-solid electrolyte batteries that do not include a polymer in the cathode. The present invention can be applied to any battery that has a solid or quasi-solid electrolyte and a cathode that is stable up to the melting point temperature of the solid or quasi-solid electrolyte component.

Claims

1. A solid lithium electrolyte battery (200) comprising at least two electrical energy storage cells (100); Each cell comprises a negative electrode (102) and a positive electrode (104; 108), the negative electrode comprising solid (106) lithium metal; A method (300; 400; 500) for extracting lithium from a battery having a first edge (110) on which the negative electrode (102) of the cell protrudes, and a second edge (112) opposite to the first edge (110) on which the positive electrode (104) protrudes; Below, in other words: — The steps (308; 408) of arranging the battery (200) in such an orientation that one of the first and second edges (110; 112) is lower than the other of the first and second edges (112; 110), - A step (310) of heating the battery (200) to a temperature called a processing temperature, which is above the melting temperature of the solid lithium metal. In the method (300; 400; 500), which includes an extraction step (306; 406) including; A method further comprising the step (314) of disconnecting the electrical connection between the positive electrodes of at least two or all of the cells (100) of the battery (200).

2. The method according to claim 1 (300; 400; 500), characterized in that the cutting step (314) cuts the connecting wire between the positive electrodes along a cutting line (802) located on the second edge (112) on the side of the electrical connecting wire, or located at the boundary of the second edge.

3. The method according to claim 1 or 2 (300; 400; 500), characterized in that the cutting step cuts the cell along a cutting line (804) located on the side of the cell or at the boundary of the second edge.

4. The method according to claim 1 or 2 (300; 400; 500), characterized in that the cutting step (314) is performed by a guillotine-type cutting machine.

5. The method according to claim 1 or 2 (500), further comprising a step (502) of charging a battery (200) prior to the extraction step (306; 406), wherein the extraction step (306; 406) is applied to the charged battery (200).

6. The method according to claim 1 or 2 (300; 400; 500), characterized in that the extraction step (306; 406) further comprises a step (312) of compressing a battery (200).

7. The method according to claim 1 or 2 (300; 400; 500), characterized by comprising the step (302) of removing at least one electrical connector from the battery (200) before the extraction step (306; 406).

8. The method according to claim 1 or 2 (300; 500), characterized in that the placement step (308) is oriented such that the first edge (110) of the battery (200) is below the second edge (112) of the battery (200).

9. The method according to claim 8 (300; 500), characterized in that the placement step (308) involves vertically positioning the battery (200) with the first edge (110) facing downward.

10. The method according to claim 8 (300; 500), characterized in that the step of heating the battery (200) (310) is carried out in an inert gas or under vacuum.

11. The method according to claim 1 or 2 (400; 500), characterized in that the placement step (408) is to place the battery (200) in an orientation such that the first edge (110) of the battery is above the second edge (112) of the battery, and the extraction step (406) further includes a step (410) of immersing the battery (200) in a liquid (702) called a processing liquid which is denser and electrically insulating than liquid lithium, prior to the heating step (310).

12. A solid lithium electrolyte battery (200) comprising at least two electrical energy storage cells (100); Each cell comprises a negative electrode (102) and a positive electrode (104; 108), the negative electrode comprising solid (106) lithium metal; Equipment (600; 700) for extracting lithium from a battery having a first edge (110) on which the negative electrode (102) of the cell protrudes, and a second edge (112) opposite to the first edge (110) on which the positive electrode (104) protrudes, - The battery (200) is positioned at one of the first and second edges (110; 1 12) is positioned so that it is lower than the other (112; 110) of the first and second edges. Means (604) for doing so; - A heating means (602) configured to heat the battery (200) to a temperature called a processing temperature, which is above the melting temperature of the solid lithium metal, and In the aforementioned equipment (600; 700) comprising: The apparatus is further characterized by comprising means (612) for disconnecting the electrical connection between the positive electrodes of at least two or all of the cells (100) of the battery (200).

13. The apparatus according to claim 12 (600; 700), characterized in that the cutting means (612) includes a guillotine-type cutting machine.

14. The apparatus (600; 700) according to claim 12 or 13, characterized in that the heating means includes an oven (602).

15. The apparatus (600; 700) according to claim 12 or 13, characterized by comprising means (608) for compressing a battery (200).

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