Method for securely extracting lithium from an electric battery comprising lithium

Abstract

The invention relates to a method (300) for extracting lithium from an electric battery comprising lithium metal, said method (300) comprising a lithium extraction phase (302), said extraction phase (302) comprising the following steps carried out, at least partially, in a chamber: - heating (304) said battery to a temperature, referred to as the treatment temperature, above or equal to the melting temperature of the lithium metal; - compressing (306) said battery in order to discharge the molten lithium out of the battery; characterized in that the heating step (304) is carried out by circulating, in said chamber, a hot stream, referred to as the heating stream, that comes into contact with said battery. The invention further relates to a system implementing such a method.

Description

DESCRIPTION Title: Safe process for extracting lithium from an electric battery containing lithium.

[0001] The present invention relates to a method for the safe extraction of lithium from an electric battery containing lithium, in particular metallic lithium. It further relates to a system implementing such a method.

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

[0003] Lithium-based batteries, particularly those using metallic lithium, are well-known. Examples include Lithium-Metal-Polymer (LMP) batteries (LMP®), which consist of a metallic lithium anode, a cathode made of a polymer layer and active material, an aluminum current collector, and an electrolyte between the anode and cathode comprising a mixture of polymer and lithium salts. These batteries are increasingly used, for example, in electric vehicles and power stations. The number of lithium-based batteries has been steadily increasing for several years, and the LMP® example, given purely as an illustration, is by no means exhaustive.

[0004] The lifespan of lithium-containing batteries is not infinite. Even at the end of their life, such a battery still contains valuable lithium that can be reused and whose value is significant, not to mention the regulatory obligation to recover said lithium.

[0005] For example, a process for recovering metallic lithium from a battery is known and described in the international application published under number WO2020 / 161339 Al. This process is very efficient and allows for to recover, in a safe manner, almost all of the lithium present in a battery cell by heating, to a temperature greater than or equal to the melting temperature of metallic Li, then compression.

[0006] However, the inventors noted that heating and / or compressing a lithium battery results in the emission of a significant amount of volatile organic compounds, or VOCs. These VOCs can cause a fire, especially at the battery processing temperatures. This can complicate the recovery of metallic lithium and the industrial-scale recycling of these end-of-life batteries.

[0007] One aim of the present invention is to remedy this drawback.

[0008] Another aim of the invention is to offer a safer and less restrictive method for recovering lithium from a battery on an industrial scale. Description of the invention

[0009] The invention makes it possible to achieve at least one of these goals by a process for extracting lithium from an electric battery comprising metallic lithium, said process comprising a lithium extraction phase, said extraction phase comprising the following steps carried out, at least in part, in an enclosure: - heating said battery to a temperature, called the processing temperature, greater than or equal to the melting point of metallic lithium; - compression of said battery to evacuate the molten lithium out of the battery; characterized in that the heating step is carried out by circulation, in said enclosure, of a hot flow, said heating flow, coming into contact with said battery.

[0010] The inventors of the present invention observed that the lithium extraction phase generates VOCs released by the battery. These VOCs are flammable and present a risk of fire. during the lithium extraction phase, which can compromise the industrial recycling of these batteries.

[0011] To remedy this situation, the invention proposes heating the battery by circulating a heating flow within the enclosure. This heating flow warms the battery. Furthermore, the heating flow circulating within the enclosure removes some or all of the VOCs from the enclosure. Thus, the invention makes it possible to remove some or all of the VOCs released by the battery from the enclosure during the heating and / or compression stages. Consequently, the invention allows for a safer extraction of lithium from a lithium battery.

[0012] The processing temperature is greater than or equal to the melting point of lithium, and in particular metallic lithium.

[0013] In particular, the processing temperature is greater than or equal to 185°C.

[0014] Following an example implementation, the processing temperature can be less than or equal to a maximum temperature, for example 300°C.

[0015] The heating flow can be a gaseous flow.

[0016] The heating flow can be an airflow, particularly dry air.

[0017] The heating flux can be a neutral gas flux, such as argon (Ar).

[0018] The heating flux can be at a temperature greater than or equal to the processing temperature. For example, the heating flux can be at a temperature of 185°C, or 200°C.

[0019] Depending on the embodiment, the temperature of the heating flow can be variable and in particular adjustable.

[0020] The battery can consist of a single cell, or several cells.

[0021] In general, the battery may have a first rim from which the negative electrodes of the cells protrude and a second rim, opposite to said first rim, from which the positive electrodes of the cells protrude.

[0022] According to the invention, part or all of the extraction phase can be carried out in one or more enclosures.

[0023] Depending on the embodiment, the heating stage and the compression stage can be carried out in the same common enclosure.

[0024] In this case, the heating flow is circulated within said single enclosure.

[0025] In this case, the heating flow can be circulated only during the heating stage. Alternatively, the heating flow can be circulated during the heating stage, but also during part or all of the compression stage, to remove the VOCs released by the battery during said compression stage.

[0026] Depending on the embodiment, the heating step can be carried out in an enclosure, called a heating enclosure.

[0027] The compression stage can be carried out in an enclosure, called a compression chamber.

[0028] In particular, the heating stage and the compression stage can be carried out in separate chambers.

[0029] The heating and compression chambers can be placed close together. Alternatively, the heating and compression chambers can be placed apart.

[0030] Depending on the embodiment, the heating chamber can be used to heat several batteries simultaneously. Indeed, the heating stage is longer than the compression stage, making it possible to heat several batteries at the same time.

[0031] According to embodiments, the process according to the invention may include a circulation of a flow, called evacuation flow, during the compression step, in particular to evacuate at least part of the volatile organic compounds, VOCs, released by the battery during said compression step.

[0032] Thus, the VOCs released by the battery during the compression stage are vented outside the chamber. The inventors observed that the battery releases a significant amount of VOCs during the compression stage. More specifically, during the compression stage, the battery releases a greater quantity of VOCs than during the heating stage. Therefore, venting the VOCs outside the chamber during the compression stage further enhances the safety of lithium extraction from a lithium battery.

[0033] Depending on the embodiment, the exhaust flow may be part or all of the heating flow. In this case, the heating flow used for heating the coil may be used as the exhaust flow during the compression stage. In this case: - the heating and compression stages can be carried out in the same chamber; or - the heating and compression stages can be carried out in separate chambers.

[0034] Depending on the embodiment, the exhaust flow may differ from the heating flow. In this case, a flow other than the heating flow may be used for VOC exhaust during the compression stage. In this case: - the heating and compression stages can be carried out in the same chamber; or - the heating and compression stages can be carried out in separate chambers.

[0035] The exhaust flow can be a gaseous flow.

[0036] The exhaust flow can be an airflow, particularly dry air.

[0037] The exhaust flow can be a neutral gas flow, such as argon (Ar).

[0038] The exhaust flow can be at ambient temperature.

[0039] Preferably, the exhaust flow can be at a temperature higher than the ambient temperature so as not to cool the battery.

[0040] Depending on the embodiment, the temperature of the exhaust flow can be variable and in particular adjustable.

[0041] According to a non-limiting example of implementation, the evacuation flow can be at a temperature of around 60°C or 65°C.

[0042] According to a non-limiting example of implementation, the evacuation flow can be at the processing temperature so as not to cool the battery during its compression.

[0043] According to embodiments, the process according to the invention may further include a measurement of the concentration of at least one volatile organic compound in the enclosure, during the extraction phase.

[0044] The measurement can be taken during the heating stage.

[0045] Alternatively, or in addition, the measurement can be carried out during the compression stage.

[0046] The measurement can be carried out in the common area, if necessary.

[0047] The measurement can be carried out in the heating chamber, and / or in the compression chamber, as appropriate.

[0048] The measured concentration can be used for: - adjust the heating flow rate, and / or - where applicable, the flow rate of the evacuation flow.

[0049] Alternatively, or in addition, the measured concentration can be used for: - to trigger or stop the flow of the evacuation stream; and / or - if necessary, trigger or stop the flow of the evacuation stream; used during the compression stage.

[0050] Alternatively, or in addition, the measured concentration can be used to trigger an alert, or an emergency stop of the heating stage, and / or the compression stage, more generally of the extraction phase.

[0051] Depending on embodiments, the method according to the invention may further include an adjustment: - the flow rate of the heating stream, and / or - where applicable, the flow rate of the evacuation flow.

[0052] This flow rate adjustment can be made based on various parameters, such as the temperature in the enclosure, the number of batteries in the enclosure, etc.

[0053] Following an example implementation, this flow rate adjustment can be made based on a measured VOC concentration, as described above.

[0054] Depending on embodiments, the process according to the invention may further include a temperature adjustment: - of the heating flow, and / or - where applicable, of the evacuation flow.

[0055] This temperature adjustment can be made based on various parameters, such as the temperature inside the enclosure, the number of batteries in the enclosure, etc.

[0056] Following an example implementation, this temperature adjustment can be made based on a VOC concentration measured in the enclosure, as described above.

[0057] According to embodiments, the process according to the invention may include recovering at least part of the heat from at least one outgoing flow of the enclosure to heat at least one incoming flow into said enclosure, or into another of the enclosures used during the extraction phase.

[0058] As described above, the invention uses a heating flow to heat the battery during the heating stage.

[0059] Furthermore, according to an optional feature, the invention can use an exhaust flow during the compression step to evacuate the VOCs released by the battery during said compression step.

[0060] Thus, the heating flow, and respectively the exhaust flow, exiting the enclosure each carry a waste heat which can be utilized in the process according to the invention, for example, to heat the heating flow and / or the exhaust flow before its introduction into the chamber. The invention may thus include a heat exchange between: - an outgoing flow from the enclosure, namely the common enclosure, the heating enclosure, or the compression enclosure; and - an incoming flow into said enclosure or into another enclosure used during the extraction phase, namely the common enclosure, the heating enclosure or the compression enclosure; to heat said incoming flow.

[0061] This reduces the energy consumed during the overall process, and decreases the energy and environmental footprint of lithium extraction.

[0062] In addition, the heating flow, or rather the exhaust flow, exiting the enclosure is laden with VOCs.

[0063] The invention may include the oxidation, and / or combustion, and more generally the recovery, of at least a portion of the VOCs present in an outgoing stream from the enclosure, namely the common enclosure, the heating enclosure, or the compression chamber. This recovery allows, firstly, the elimination of said VOCs so that they no longer present a fire risk. Secondly, this exothermic combustion generates heat that can be used to heat an incoming stream from the enclosure, namely the common enclosure, the heating enclosure, or the compression chamber.

[0064] This reduces the energy consumed during the overall process, and decreases the energy and environmental footprint of lithium extraction, while further securing lithium extraction.

[0065] According to embodiments, the process according to the invention may include reusing at least part of a flow exiting an enclosure, to reuse it as a flow entering said enclosure, or at least one of the enclosures, used during the extraction phase.

[0066] In this case, the process according to the invention may further include the removal of at least a portion of the VOCs in said outgoing stream. Following one example, VOC removal can be achieved, for example, by combustion. Following another example, VOC removal can be achieved, for example, by trapping or filtering said VOCs using a carbon filter / column through which the outgoing stream passes.

[0067] The compression stage forces the molten lithium out of the battery.

[0068] The compression stage can be carried out continuously throughout the extraction phase. In this case, the battery is subjected to compression, partially or completely, throughout the extraction phase, and particularly during the heating stage.

[0069] Alternatively, the compression step can be carried out after the heating step, i.e., when the heating step is complete.

[0070] The compression stage can apply compression to the battery surface by sweeping the surface from the second edge, where the positive electrodes protrude, towards the first edge, where the negative electrodes protrude. This gradually guides the molten lithium towards the first edge, increasing the amount of lithium recovered and reducing the risk of contact (or short circuit) between the lithium and the positive electrodes.

[0071] For example, the compression step can be carried out by passing the battery between two rollers, in particular two heated rollers.

[0072] Following another example, the compression step can be carried out by a compression roller, in particular heated, compressing the battery against a support surface, in particular heated.

[0073] Compression can be applied in successive passes, each pass sweeping across the surface of the battery starting from the second edge towards the first edge.

[0074] The space between the compression rollers, or between the compression roller and the bearing surface, can correspond to the battery thickness minus the thickness of the metallic lithium layers. This allows compression to be applied as long as there is metallic lithium remaining in the battery.

[0075] 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 battery.

[0076] 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.

[0077] According to embodiments, the process according to the invention may further include, before the extraction phase, an electrical charging step of the battery, said extraction phase being applied to said charged battery.

[0078] Electrically charging the battery and performing the extraction phase on the electrically charged battery increases the lithium extraction yield. This is because the electrical charging of a cell moves lithium ions towards the negative electrode, thus increasing the amount of lithium that can be recovered.

[0079] In cases where the battery comprises multiple cells, the method according to the invention may further include a step of breaking the electrical connection between the positive electrodes of at least two, and in particular all, of the cells of said battery. Thus, the electrical connection between the cells is broken, which reduces the risk of fire or ignition.

[0080] According to one embodiment, the cutting step can perform a cut of connecting wires between the positive electrodes along a cutting line located at the level, and in particular at the limit, of the second border, on the side of said electrical connecting wires.

[0081] This embodiment allows for the retention, or not removal, of solid metallic lithium from the battery when the electrical connections are cut, thereby improving the lithium recovery efficiency.

[0082] In this embodiment, 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.

[0083] According to another embodiment, the cutting step can perform a cutting of the cells along a cutting line located at the level, and in particular at the limit, of the second border, on the side of the cells.

[0084] In this embodiment, in order to reduce the amount of lithium lost, the cut must be in the immediate vicinity of the second edge.

[0085] For example, the cut can be made at a distance "d" from the second edge less than or equal to 2mm, or less than or equal to 1% of the cell dimension between the first and second edges of the battery.

[0086] The cutting step can be carried out by cutting. In this case, the battery can be inserted into a cutter of suitable size and power.

[0087] The shutdown step can be carried out before the heating step.

[0088] Furthermore, the process according to the invention may include, prior to the extraction phase, a step of removing at least one electrical connector from the battery, also called a "crimp" in English.

[0089] This makes battery processing easier.

[0090] For example, the step of removing at least one electrical connector from the battery may include a step of removing at least one negative connector, also called the "crimp anode." This facilitates / improves the flow of molten lithium out of the cell.

[0091] For example, the step of removing at least one electrical connector from the battery may include a step of removing at least one positive connector, also called a "crimp cathode".

[0092] Furthermore, the process according to the invention may include, before the extraction phase, a step of removing excess material at the level of at least one, and particularly each, edge of the battery.

[0093] According to embodiments, the method according to the invention may further include a step of positioning the battery in an orientation in which the first border is below the second border.

[0094] Such an orientation of the battery, and therefore of each cell of the battery, 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 electrical arc, such a short circuit being able to cause a fire.

[0095] According to a preferred embodiment of this first version, the positioning step can achieve a vertical positioning of the battery, in which the first edge is at the bottom.

[0096] Thus, the flow of molten lithium out of each cell, by gravity, is improved.

[0097] Furthermore, the risk of contact between the molten lithium and the positive electrode(s) is reduced, or even eliminated.

[0098] According to another aspect of the same invention, a lithium extraction system is proposed for an electric battery containing lithium, said system comprising: - at least one heating means, in an enclosure, configured to heat said battery to a temperature, called the processing temperature, greater than or equal to the melting temperature of said metallic lithium; - at least one means of compressing said battery to evacuate the molten lithium out of the battery; characterized in that the heating means includes a first means of circulation, in said enclosure, of a hot flow, said heating flow, coming into contact with said battery.

[0099] In general, the system according to the invention may include, in terms of technical means, or hardware configuration and / or software configuration, at least one, or any combination of at least two, of the optional features described above with reference to the method according to the invention.

[0100] The first means of circulation may include a means of blowing and / or a means of suction.

[0101] According to embodiments, the system according to the invention may include a common enclosure in which the heating and compression of the battery are carried out.

[0102] According to embodiments, the system according to the invention may include a separate enclosure, called a heating enclosure, in which the heating of the battery is carried out.

[0103] According to embodiments, the system according to the invention may include a separate enclosure, called a compression enclosure, in which the compression of the battery is carried out.

[0104] Depending on the embodiment, the heating chamber can be used to heat several batteries at once.

[0105] According to embodiments, the system according to the invention may include a heating chamber for several compression chambers.

[0106] In this case, at least two batteries heated in the same heating chamber can be compressed in different compression chambers.

[0107] According to embodiments, the system according to the invention may include a second means of circulating a flow, called evacuation flow, during the compression of the battery, in particular to evacuate at least part of the VOCs released by the battery.

[0108] This second circulation method can correspond, at least in part, to the first circulation method. In this case, the exhaust flow can be the heating flow. Also in this case, heating and compression of the coil can be achieved: - within a common enclosure, or - in separate enclosures.

[0109] This second circulation method may be, at least in part, different from the first circulation method. In this case, the exhaust flow is not the heating flow. Also in this case, heating and compression of the coil can be achieved: - within a common enclosure, or - in separate enclosures.

[0110] The second means of circulation may include a means of blowing and / or a means of suction. [YES] Depending on the embodiment, the first means of circulation may be adjustable / controllable to adjust: - the flow rate, and / or - the temperature; of the heating flow.

[0112] The adjustment can be made based on a measured temperature, or a measured concentration of VOCs.

[0113] Depending on the embodiment, the second means of circulation may be adjustable / controllable to adjust: - the flow rate, and / or - the temperature; of the exhaust flow.

[0114] The adjustment can be made based on a measured temperature, or a measured concentration of VOCs.

[0115] According to embodiments, the system according to the invention may include at least one gas sensor for measuring the concentration of at least one volatile organic compound, VOC.

[0116] When heating and compression of the battery are carried out in a common enclosure, at least one measuring means may be disposed in said common enclosure, or at least equip said common enclosure.

[0117] When the heating and compression of the battery are carried out in separate enclosures, namely a heating enclosure and a compression enclosure, then the system according to the invention may include - at least one sensor equipping the heating enclosure, and / or - at least one sensor equipping the compression enclosure.

[0118] The system according to the invention may further include at least one means of recovering at least a portion of the energy from at least one outgoing flow from an enclosure of the system according to the invention, to heat at least one incoming flow into said enclosure, or into at least one enclosure, of the system according to the invention.

[0119] Such a recovery method may include a heat exchanger to recover some of the waste heat from the outgoing stream.

[0120] Such a recovery method may include a means of combustion, or oxidation, and more generally of valorization, to burn the VOCs present in the outgoing stream and thus generate usable heat to heat the incoming stream.

[0121] The system according to the invention may further include at least one means for recirculating at least a part of a flow exiting an enclosure of the system according to the invention, for reuse as a flow entering said enclosure, or at least one of the enclosures, of the system according to the invention.

[0122] In this case, the system according to the invention may further comprise at least one means for removing VOCs from said outgoing stream. Following a As an example of implementation, VOC removal can be achieved through combustion. Another example is the trapping or filtration of VOCs by a carbon filter / column through which the outgoing stream passes.

[0123] The means of compression can take any form.

[0124] Depending on the embodiment, the compression means may include at least one roller, in particular a heated one.

[0125] In particular, the compression method may include a single roller, especially a heated one, compressing the battery against a support surface, especially a heated one. The support surface may be heated to accelerate the battery's temperature rise.

[0126] Alternatively, the compression method may include two rollers, particularly heated ones, between which the battery is passed.

[0127] In general, the compression method can be configured to apply continuous compression throughout the extraction phase.

[0128] Alternatively, the compression method can be configured to apply compression discretely over time, once or several times, during the extraction phase. In this case, the extraction phase includes periods when the battery is not subjected to compression.

[0129] Advantageously, the compression device can be configured to apply compression, of constant or variable value, progressively or by sweeping across the battery surface, 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, increasing the amount of lithium recovered and reducing the risk of contact between the lithium and the positive electrodes.

[0130] When using one or two compression rollers, compression can be applied to the battery in successive passes. Each pass applies sweeping compression to the battery surface, from the second edge to the first edge. At the end of each pass, the compression can be stopped by separating the rollers. or by moving the roller away from the support surface, to return to the second edge in order to start a new pass.

[0131] The distance between the rollers, respectively between the compression roller and the bearing surface, can be decreased with each pass, and in particular between two successive passes.

[0132] According to embodiments, the system according to the invention 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 battery.

[0133] For example, the cutting tool may include a paper cutter. Description of the figures and methods of implementation

[0134] Other advantages and features will become apparent upon examination of the detailed description of non-limiting embodiments and the accompanying drawings, in which: - FIGURE 1 is a schematic representation of a non-limiting example embodiment of a cell within the meaning of the present invention; - FIGURE 2 is a schematic representation of a non-limiting example of a battery within the meaning of the present invention; - FIGURES 3-5 are schematic representations of non-limiting examples of embodiments of a process according to the invention; - FIGURES 6a-6c are schematic representations of a non-limiting example embodiment of a system according to the present invention; - Figures 7a-7c are schematic representations of another, non-limiting embodiment of a system according to the present invention; and - FIGURES 8a-8c are schematic representations of another non-limiting embodiment of a system according to the present invention.

[0135] It is understood that the embodiments described below are by no means exhaustive. 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.

[0136] In the figures, elements common to several figures retain the same reference.

[0137] FIGURE 1 is a schematic representation of a non-limiting example embodiment of a cell within the meaning of the present invention.

[0138] The cell 100, shown in FIGURE 1, includes a negative electrode 102. According to a non-limiting embodiment, the negative electrode 102 is formed by, or comprises, a layer of solid metallic lithium.

[0139] The cell 100 further includes a positive electrode 104. According to a non-limiting embodiment, the positive electrode 104 is formed by a polymer-based layer and active material.

[0140] A layer 106 of electrolyte is disposed between the negative electrode 102 and the positive electrode 104. According to a non-limiting embodiment example, this solid electrolyte layer 106 may, for example, comprise lithium salts.

[0141] The cell 100 further includes a current collector 108, on the side of the positive electrode 104. According to a non-limiting embodiment example, the current collector 108 can be made of aluminum.

[0142] According to a non-limiting architecture, in the example of FIGURE 1, the negative electrode 102 of cell 100 protrudes from the other elements of cell 100 on the side of a first border 110 of cell 100. Always according to the non-limiting architecture of FIGURE 1, the positive electrode 104, and / or the collector 108, of the cell 100 protrudes from the other elements of the cell 100 on the side of a second border 112, opposite to the first border 110.

[0143] Of course, cell 100 shown in FIGURE 1 is a highly simplified embodiment, given for illustrative purposes only and is not intended to be limiting. The cell as defined in the present invention may comprise a multitude or a succession of several anode / electrolyte / cathode layers, or at least one other layer than those indicated, or at least one layer whose composition differs from the composition given herein by way of non-limiting example.

[0144] FIGURE 2 is a schematic representation of a non-limiting example embodiment of a battery within the meaning of the present invention.

[0145] A battery according to the present invention may comprise one or more cells, and in particular one or more cells 100 of FIGURE 1.

[0146] In the example shown in FIGURE 2, the 200 battery comprises n cells 100i-100n, with n>l.

[0147] All 100i-100n cells can be identical.

[0148] The 100i-100n cells are assembled along a direction 202 perpendicular to the plane of each 100i cell.

[0149] Each 100i cell, with the <i<n, peut être identique à la cellule 100 de la FIGURE 1.

[0150] Of course, the 200 battery may include other components than those shown in FIGURE 2 which gives a simplified schematic representation of a battery.

[0151] In the following, and without loss of generality, we consider that the battery comprises several cells assembled according to an assembly direction.

[0152] FIGURE 3 is a schematic representation of a non-limiting example embodiment of a method according to the present invention.

[0153] The 300 process of FIGURE 3 can be used to recover lithium from a battery containing lithium, in particular metallic lithium, and even more particularly from battery 200 of FIGURE 2.

[0154] Process 300 includes a phase 302 of lithium extraction from the battery by heating and compression of the battery.

[0155] To do this, the extraction phase 302 includes a step 304 of heating the battery.

[0156] In the embodiment shown in FIGURE 3, the battery is heated within a chamber, referred to as a heating chamber. More specifically, the battery is placed in a closed heating chamber through which a heating gas flow is circulated.

[0157] In practice, a hot heating gas is introduced into the chamber, circulates within it, and comes into contact with the battery to heat it, before exiting the chamber. This circulation of the heating gas within the chamber is carried out for a sufficient duration, for example, approximately 1 hour and 20 minutes, to bring the battery to a treatment temperature of 185°C or higher. At this temperature, the metallic lithium in the battery begins to melt and is ready to flow out. Of course, the duration indicated above is purely indicative and in no way restrictive.

[0158] The inventors of the present invention observed that the heating step 304 causes the release of VOCs from the battery. These VOCs then accumulate in the enclosure where the battery heating takes place and constitute a potential source of fire.

[0159] The invention proposes to address this problem by achieving, during the heating stage, the evacuation of VOCs from the enclosure using the heating flow circulating within the enclosure. Indeed, heating the coil by circulating a heating flow within the enclosure also allows for the evacuation of the VOCs released by said coil during said heating stage, from said enclosure, by said heating flow circulating within the enclosure. In other words, the The heating gas flow, in addition to heating the battery, also ventilates the inside of the enclosure and carries VOCs out of the enclosure during the heating stage.

[0160] The exhaust gas stream may be at a temperature greater than or equal to the processing temperature, in particular 185°C. The heating gas stream may consist of air, in particular dry air, or an inert gas, such as argon.

[0161] The extraction phase 302 includes a step 306 of compressing the heated battery to force the molten metallic lithium, contained in the heated battery, to evacuate out of said battery.

[0162] In the embodiment shown in Figure 3, the battery compression is performed in a chamber, referred to as a compression chamber. More specifically, the battery, heated to at least 185°C, is placed in a compression chamber equipped with compression devices. It is then compressed perpendicular to the plane of the cells to force the molten lithium out of the battery. The molten lithium is collected, for example, in a tray or container positioned beneath the battery.

[0163] Battery compression can be achieved in various ways. According to a non-limiting example, the heated battery is passed between two rollers, particularly heated ones, which apply compression to the battery surface by sweeping across it, for example, from the second edge 112 to the first edge 110, from which the negative electrodes 102 of the battery cells protrude. Thus, the molten lithium is gradually drawn / guided towards the first edge and then exits the battery through the first edge.

[0164] The inventors of the present invention observed that the compression step 306 causes the release of VOCs from the battery. These VOCs then accumulate in the enclosure and constitute a potential source of fire.

[0165] In the non-limiting example of FIGURE 3, the extraction phase 302 further includes an optional step 310 for the removal of VOCs during the compression step 306. This evacuation of VOCs can be carried out during the entire duration of the compression step, or only part of the compression step 306, or just after the compression step.

[0166] Step 310 removes VOCs from the enclosure by circulating an exhaust gas flow within it. This exhaust gas flow ventilates the interior of the enclosure and carries the VOCs out of it.

[0167] The exhaust gas stream can be the heating gas stream used during heating stage 304.

[0168] Alternatively, the exhaust gas stream can be a different stream than the heating gas stream. In this case, the exhaust gas stream can be at ambient temperature. Alternatively, the exhaust gas stream can be at a temperature higher than ambient temperature, for example, 60°C. The exhaust gas stream can consist of air, particularly dry air, or an inert gas, such as argon.

[0169] The heating and compression chambers may be separate, but not limited to these options: in this case, they may be in contact with each other or separated. Alternatively, the heating and compression chambers may be a single, combined chamber.

[0170] The invention is not limited to any particular enclosure architecture.

[0171] Depending on a feature not shown, extraction phase 302 may include a measurement of the VOC concentration in the heating chamber. For example, this measurement may be performed at a fixed frequency or continuously. The measured concentration may be used for: - to trigger or stop the heating stage 304, - to adjust the flow rate, and / or temperature, of the heating flow, and / or - an emergency stop.

[0172] According to a feature not shown, the extraction phase 302 may include a measurement of the VOC concentration in the compression chamber. For example, this measurement may be carried out at frequency fixed or continuous. The measured concentration can be used for: - to start or stop compression step 306, - adjust the flow rate, and / or temperature, of the evacuation flow, and / or - an emergency stop.

[0173] FIGURE 4 is a schematic representation of another non-limiting embodiment of a method according to the present invention.

[0174] The 400 process of FIGURE 4 can be used to recover lithium from a battery containing lithium, in particular metallic lithium, and even more particularly from battery 200 of FIGURE 2.

[0175] The process 400 of FIGURE 4 includes a lithium extraction phase 402 comprising all the steps of the extraction phase 302 of the process 300 of FIGURE 3, except the VOC removal step 310 during the compression step.

[0176] FIGURE 5 is a schematic representation of another non-limiting embodiment of a method according to the present invention.

[0177] The 500 process of FIGURE 5 can be used to recover lithium from a battery containing lithium, in particular metallic lithium, and even more particularly from battery 200 of FIGURE 2.

[0178] Process 500 includes an optional step 502, which performs electrical recharging of the battery. The battery can be partially or fully charged. Electrically charging the battery increases the amount of lithium available for extraction because the recharging process causes lithium ions to migrate from each battery cell to its negative electrode.

[0179] Process 500 includes an optional step 504 of breaking the electrical connection between the positive electrodes of at least two, and in particular all, of the cells of said battery. Thus, the electrical connection between the cells is broken, which reduces the risk of fire or ignition.

[0180] Process 500 includes an optional step 506 for removing electrical connectors, and in particular current concentrators, also known as "crimps." Specifically, step 506 removes anode crimps to facilitate the flow of molten lithium from each cell, and optionally removes cathode crimps. Optionally, step 506 can also remove excess material, particularly solid metallic lithium, from each lateral edge of the battery.

[0181] The process 500 further includes an optional but highly advantageous step 508 for positioning the battery in an orientation where the first edge, 110 in the example of battery 200, from which the negative electrodes protrude, is lower than the second edge, 112 in the example of battery 200, from which the positive electrodes and collectors protrude. Specifically, step 508 positions the battery in a vertical orientation, that is, parallel to the gravity vector, with the first edge at the bottom. Preferably, but not exclusively, the battery is maintained in this orientation throughout the extraction phase.

[0182] Next, process 500 includes an extraction phase 510, such as for example extraction phase 302 or 402 described with reference to FIGURES 3 and 4.

[0183] FIGURES 6a-6c are schematic representations of a non-limiting example embodiment of a system according to the present invention.

[0184] The 600 system in FIGURES 6a-6c can be used to extract and recover lithium from a battery containing lithium, especially metallic lithium, and even more particularly from the 200 battery in FIGURE 2.

[0185] System 600 can be used to implement a process according to the invention, for example any one of processes 300, 400 or 500.

[0186] The 600 system includes a heating chamber 602 in which the battery 200 is heated, a compression chamber 604 in in which the 200 battery is compressed, and optionally a 606 enclosure for cooling the 200 battery after lithium extraction.

[0187] In FIGURE 6a, battery 200 is located in the heating chamber 602, in FIGURE 6b battery 200 is located in the compression chamber 604 and in FIGURE 6c battery 200 is located in the optional cooling chamber 606.

[0188] During its processing in the 600 system, the 200 battery can optionally be placed on a 608 support.

[0189] The support 608 allows the battery 200 to be positioned and held in an orientation where the first edge 110, from which the negative electrodes protrude, is below the level of the second edge 112, from which the positive electrodes protrude. In the example in FIGURE 6, the support 608 holds the battery 200 in a vertical position with the first edge 110 at the bottom and the second edge 112 at the top.

[0190] Furthermore, the support 608 can be equipped with a receptacle 610 to receive the molten lithium metal. In particular, the molten lithium metal exiting the battery 200 flows out of said battery 200 and then towards the receptacle 610 under the effect of gravity and is collected in said receptacle 610.

[0191] In some embodiments, the support 608 and the receptacle 610 can be formed from a single piece, or a single component.

[0192] The heating chamber 602 is equipped with a first means for circulating a heating flow within the heating chamber 602 to raise the battery 200 to a processing temperature greater than or equal to the melting point of metallic lithium, for example, greater than or equal to 185°C. In the example shown in FIGURES 6a-6c, the first circulation means comprises: - an inlet duct 614i for the heating flow into the heating chamber 602, - an outlet duct 6142 for the heating flow out of the heating chamber 602, and - a means of driving the heating flow 6143, such as for example a fan, a blower, etc. Thus, the heating flow enters the heating chamber 602 through the inlet duct 614i, sweeps through the heating chamber 602, and in particular the battery 200 located in the chamber to heat said battery 200, and exits through the outlet duct 6142 carrying some or all of the VOCs.

[0193] The heating flux can be a dry air flux or an inert gas flux, such as argon (Ar). The heating flux can be at a temperature higher than the processing temperature, for example, greater than or equal to 185°C.

[0194] Optionally, the heating chamber 602 can be equipped with a sensor 616 to measure the VOC concentration within it. This sensor 616 can be configured to measure the VOC concentration continuously or at a predetermined frequency. The concentration measured by sensor 616 can be used to start, stop, or adjust the circulation of the heating flow, either directly or via a control module (not shown). In this case, the drive means 6143 can be controllable / adjustable. The concentration measured by sensor 616 can be used to adjust the temperature of the heating flow. The concentration measured by sensor 616 can be used to trigger an emergency shutdown of the system 600, and in particular, the heating system.

[0195] Of course, the 602 heating enclosure may include other component(s) than those described here.

[0196] In the compression chamber 604, the battery 200 is held by the support 608 as described above.

[0197] The compression chamber 604 is equipped with a battery compression means for forcing the molten lithium metal out of said battery 200. In the example of FIGURES 6a-6c, the compression means comprises a pair of rollers 622, particularly heated, facing each other. The battery 200 is positioned between the rollers 622 in a vertical orientation in which the first edge 110 is below the second edge 112. The rollers 622 apply, for example by successive passes, a compression on the battery 200 by sweeping the battery 200 in the direction from the second border 112 to the first border 110. Thus, the molten metallic lithium exits the battery 200 through the first border 110 and flows into the recovery receptacle 610. This example of compression means is by no means limiting and other variants may be used.

[0198] Optionally, the compression chamber 604 is equipped with a means for removing VOCs from said chamber 604. In the example shown in FIGURES 6a-6c, said removal means includes a second means for circulating a removal flow within said compression chamber 604. In particular, the second means for circulating the removal gas flow includes: - an inlet duct 624i for the exhaust flow into the compression chamber 604, - an outlet conduit 6242 for the exhaust flow from the compression chamber 604, and - a means of driving said evacuation flow, such as for example a fan, a blower, etc. Thus, the exhaust flow enters the compression chamber 604 through the inlet duct 624i, sweeps through the compression chamber 604, and in particular the battery 200 located in the chamber, and exits through the outlet duct 6242 carrying some or all of the VOCs located in the compression chamber 604.

[0199] The exhaust flow can be the heating flow.

[0200] Alternatively, the exhaust flow can be a dry air flow or a neutral gas flow, such as argon (Ar). The exhaust flow can be at ambient temperature or at a temperature higher than ambient temperature, for example around 60°C, or even at the processing temperature so as not to cool the battery 200 during its compression.

[0201] Optionally, the compression chamber 604 can be equipped with a sensor 626 to measure the VOC concentration within said chamber 604. This sensor 626 can be configured to measure the VOC concentration continuously or at a predetermined frequency. The concentration measured by the sensor 626 can be used to start, stop, or Adjust the flow of the exhaust gas within the compression chamber, either directly or via a control module (not shown). In this case, the drive means 6243 can be controlled / adjustable. The concentration measured by sensor 626 can be used to adjust the temperature of the exhaust gas. The concentration measured by sensor 626 can also be used to trigger an emergency shutdown of system 600, and in particular, of the compression unit.

[0202] Of course, the 604 compression chamber may include other component(s) than those described here.

[0203] In the optional cooling enclosure 606, the 200 battery can be held by the bracket 608 as described above.

[0204] The cooling of battery 200 in the cooling enclosure 606 can be achieved in any known or suitable manner, for example by circulating a cooling flow which may be a flow of dry air or a flow of inert gas such as argon. The cooling flow may be at ambient temperature or below ambient temperature.

[0205] The 606 cooling enclosure can optionally be equipped with: - a means of VOC evacuation (not shown); and / or - a sensor for measuring VOC concentration (not shown); and / or - a temperature measurement sensor to ensure that the cell is properly cooled before leaving the machine; in a similar or identical manner to what has just been described for the heating chamber 602 or for the compression chamber 604.

[0206] Of course, the 606 cooling enclosure may include other component(s) than those described here.

[0207] In system 600, the heating chamber 602, the compression chamber 604, and the optional cooling chamber 606 are separate from one another. Of course, the invention is not limited to this embodiment.

[0208] In the example shown in FIGURES 6a-6c, each of the heating chambers 602 and compression chambers 604 respectively has its own means for circulating the heating flow and the exhaust flow, respectively. Of course, the invention is not limited to this embodiment.

[0209] FIGURES 7a-7c are schematic representations of another non-limiting embodiment of a system according to the present invention.

[0210] The 700 system of FIGURES 7a-7c can be used to extract and recover lithium from a battery containing lithium, in particular metallic lithium, and even more particularly from the 200 battery of FIGURE 2.

[0211] System 700 can be used to implement a process according to the invention, for example any one of processes 300, 400 or 500.

[0212] Unlike the 600 system, the 700 system includes a single common enclosure 702 for heating and compressing the battery 200. Optionally, the 700 system can also include the cooling enclosure 606 of the 600 system, separate from the common enclosure 702.

[0213] The common enclosure 702 is equipped only with the first circulation means 6141-6143 described with reference to FIGURES 6a-6c. This first circulation means 6141-6143 circulates the heating flow during the heating stage to heat the coil. Additionally, optionally, but preferably, the first circulation means 6141-6143 circulates the heating flow during the coil compression stage to remove the VOCs released by the coil during said compression stage.

[0214] Optionally, the common enclosure 702 can be equipped with a sensor for measuring the concentration of VOCs in said common enclosure 702, such as, for example, sensor 616.

[0215] The common enclosure 702 includes a heating zone 704 in which the battery 200 is positioned during the heating stage.

[0216] The common enclosure 702 includes a compression zone 706 comprising a battery compression means 200, for example rollers 622.

[0217] In FIGURE 7a, battery 200 is located in the heating zone 704, in FIGURE 7b battery 200 is located in the compression zone 706 and in FIGURE 7c battery 200 is located in the optional cooling enclosure 606.

[0218] FIGURES 8a-8c are schematic representations of another non-limiting embodiment of a system according to the present invention.

[0219] The 800 system in FIGURES 8a-8c can be used to extract and recover lithium from a battery containing lithium, especially metallic lithium, and even more particularly from the 200 battery in FIGURE 2.

[0220] System 800 can be used to implement a process according to the invention, for example any one of processes 300, 400 or 500.

[0221] The 800 system includes all the elements of the 600 system in FIGURES 6a-6c except for the differences indicated below.

[0222] In the 800 system, the outlet duct 6142 of the heating chamber 602 is connected to the inlet duct 624i of the compression chamber 604. Thus, the heating flow used in the heating chamber 602 is used as the exhaust flow in the compression chamber 604, separate from the heating chamber 602.

[0223] The 800 system includes only the drive means 6143 and does not include the drive means 6243. The sensor 616 and / or the sensor 626 can act on the drive means 6143, either directly or via a control module (not shown).

[0224] Of course, the 600 system, or the 700 system or the 800 system respectively, may include other components than those described above, such as, for example: - a means of electrically recharging the 200 battery, and / or - a means of removing electrical connectors from said battery 200, and / or - a means of breaking the electrical connection between the positive electrodes of the 200 battery, and / or - etc.

[0225] Of course, the invention is not limited to the detailed examples above.

Claims

- 32 - DEMANDS 1. A process (300;400;500) for extracting lithium from an electric battery (200) comprising metallic lithium, said process (300;400;500) comprising a lithium extraction phase (302;402;510), said extraction phase (302;402;510) comprising the following steps carried out, at least in part, in a chamber (602,604;702): - heating (304) of said battery (200) to a temperature, called the processing temperature, greater than or equal to the melting point of metallic lithium; - compression (306) of said battery (200) to evacuate the molten lithium out of the battery; characterized in that the heating step (304) is carried out by circulation, in said enclosure (602;702), of a hot flow, said heating flow, coming into contact with said battery (200).

2. Method (300;400;500) according to claim 1, characterized in that the heating step (304) and the compression step (306) are carried out in the same enclosure (702).

3. Method (300;400;500) according to claim 1, characterized in that the heating step (304) and the compression step (306) are carried out in separate enclosures.

4. Method (300;400;500) according to any one of the preceding claims, characterized in that it comprises a circulation (310) of a flow, said evacuation flow, during the compression step (306), in particular to evacuate at least a part of volatile organic compounds, VOCs, released by the battery (200) during said compression step (306).

5. A process (300;400;500) according to any one of the preceding claims, characterized in that it comprises a measurement of the concentration of at least one volatile organic compound in the enclosure (602,604;702), during the extraction phase (302;402;510). - 33 - 6. A method (300;400;500) according to any one of the preceding claims, characterized in that it comprises - an adjustment of the flow rate; and / or - an adjustment of the temperature; of the heating flow, respectively of the exhaust flow.

7. Method (300;400;500) according to any one of the preceding claims, characterized in that it comprises recovering at least a part of the heat from at least one outgoing stream of the enclosure to heat at least one incoming stream into said enclosure.

8. A process (300;400;500) according to any one of the preceding claims, characterized in that it comprises a recovery, and in particular an oxidation and / or a combustion, of at least a part of the VOCs found in a stream exiting the enclosure.

9. A method (300;400;500) according to any one of the preceding claims, characterized in that it comprises reusing at least a part of a flow exiting a chamber, for reuse as a flow entering said chamber, or at least one of the chambers, used during the lithium extraction phase.

10. Method (300;400;500) according to claim 9, characterized in that it comprises an elimination of at least a part of the VOCs found in the outgoing stream, in particular by combustion, trapping or filtering, of said VOCs.

11. A lithium extraction system (600;700;800) for an electric battery comprising lithium, said system comprising: - at least one heating means, in an enclosure (602;702), configured to heat said battery (200) to a temperature, called the processing temperature, greater than or equal to the melting temperature of said metallic lithium; - at least one compression means (622) of said battery (200) to evacuate the molten lithium out of the battery (200); characterized in that the heating means comprises a first circulation means (6141-6143), in said enclosure (602;702), of a hot flow, said heating flow, coming into contact with said battery.

12. System (700) according to claim 11, characterized in that it comprises a common enclosure (702) in which the heating and compression of the battery are carried out.

13. System (600;800) according to claim 11, characterized in that it comprises: - a separate enclosure (602), called a heating enclosure, in which the heating of the battery (200) is carried out, and / or - a separate enclosure (604), called a compression enclosure, in which the compression of the battery (200) is carried out.

14. System according to the preceding claim, characterized in that it comprises a heating chamber for several compression chambers.

15. System (600) according to any one of claims 11 to 14, characterized in that it comprises a second means (6242-6243) for circulating a flow, called evacuation flow, during the compression of the battery (200), in particular to evacuate at least part of the VOCs released by the battery (200).

16. System (600;700;800) according to any one of claims 11 to 15, characterized in that it comprises a gas sensor (616,626) for measuring the concentration of at least one volatile organic compound.

17. System (600;700;800) according to any one of claims 11 to 16, characterized in that the first means of transport (6141-6143), respectively the second means of transport (6141-6143), is adjustable / controllable to adjust the flow rate and / or flow temperature.

18. System according to any one of claims 11 to 17, characterized in that it comprises at least one means for recovering at least a part of the heat from at least one flow exiting an enclosure of said system, to heat at least one flow entering said enclosure, or another enclosure of said system.

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