Process for the extraction by pushing of electrochemical bundles from disused and / or end-of-life electrochemical accumulators, assembled by battery module or by battery pack, with a view to their recycling.

Abstract

Method for the extraction by pushing of electrochemical bundles from disused and / or end-of-life electrochemical accumulators, assembled by battery module or by battery pack, with a view to their recycling. The invention relates to a method for separating an electrochemical bundle from its packaging (case or flexible) of a disused and / or end-of-life accumulator, which is integrated within a module and / or a battery pack, comprising the successive cutting of the two end sections of packaging, the mechanical reinforcement of the module between the two cuts in order to ensure mechanical cohesion between the accumulators, the pressing against a support, the insertion of a dedicated pushing tool into the electrochemical bundle and then extracting the latter by pushing out of the packaging. Figure for the abstract: fig.6D

Description

Title of the invention: Method for extracting by pushing electrochemical bundles from disused and / or end-of-life electrochemical accumulators, assembled by battery module or by battery pack, with a view to their recycling. Technical field

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

[0002] The invention aims mainly to propose a reliable and easy solution for extracting the electrochemical bundle from end-of-life accumulators, at the scale of the accumulator or of a module or of a battery pack, with a view to their recycling.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[0018] The electrolyte component 1 may be in solid, liquid or gel form. In this In the latter form, the constituent may comprise a polymer, ceramic or microporous composite separator soaked with organic electrolyte(s) or ionic liquid type which allows the movement of the Lithium ion from the cathode to the anode for charging and vice versa for discharging, which generates the current. The electrolyte is generally composed of a mixture of organic, non-aqueous solvents and lithium salts, as well as additives to improve performance, such as the formation and growth of electrode / electrolyte interfaces (SEI), limitation of side reactions, etc. Electrolytes can be composed of binary or ternary mixtures based on cyclic carbonates (ethylene carbonate, propylene carbonate, butylene carbonate), linear or branched (dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, dimethoxyethane) in various proportions in which one or more lithium salts are dissolved, such as LiPF6, LiCF3SO3, LiFSI, LiTDI, LiDFOB, LiBF4, LiC104, etc.

[0019] The positive electrode or cathode 2 is made of lithium cation insertion materials which are generally composite, such as lithium iron phosphate LiFePO4, lithium cobalt oxide LiCoO2, lithium manganese oxide, possibly substituted, LiMn2O4 or transition metal oxide, such as lamellar materials for example, a material based on LiNixMnyCozO2 with x+y+z = 1, such as LiNi0.33Mn0.33 Coo,3302 or LiNi0.8Mno.iCoo.i02,, or a material based on nickel cobalt aluminum oxide type LiNixCoyAlzO2 with x+y+z = 1, such as LiNi0.xCo0 15AI0.05CL.

[0020] The negative electrode or anode 3 is very often made of graphite carbon or Li4TiO5O12 (titanate material), possibly also based on silicon or a composite formed from silicon. This negative electrode, like the positive electrode, may also contain electronically conductive additives as well as polymer additives which give it mechanical properties and electrochemical performances appropriate to the lithium-ion battery application or to its implementation method.

[0021] The anode and the cathode made of lithium insertion material can be deposited continuously using a standard technique in the form of an active layer on a metal sheet or foil constituting a current collector.

[0022] The current collector 4 connected to the positive electrode is generally made of aluminum.

[0023] The current collector 5 connected to the negative electrode is generally made of copper, nickel-plated copper or aluminum. More specifically, aluminum is used for the current collectors common to positive and negative electrodes of titanate Li4Ti50i2. Copper is rather for the negative electrodes of graphite (Cgr), silicon (Si) or silicon composite (Si-C).

[0024] A lithium-ion battery or accumulator can obviously comprise a plurality of electrochemical cells which are stacked on top of each other.

[0025] Traditionally, a Li-ion battery or accumulator uses a couple of materials at the anode and cathode allowing it to operate at a high voltage level, typically 1.5 and 4.2 Volts.

[0026] Depending on the type of application and / or the production method targeted, the aim is to produce either a thin and flexible lithium-ion accumulator or a rigid accumulator: the packaging is then either flexible or rigid and in the latter case constitutes a sort of case.

[0027] Flexible packaging commonly called “pouch” is usually manufactured from a multi-layer composite material, consisting of a stack of aluminum layers covered by one or more polymer films laminated by bonding.

[0028] Rigid packaging (battery cases) is usually made from a metallic material, typically an aluminum alloy or stainless steel or a rigid polymer such as acrylonitrile butadiene styrene (ABS).

[0029] The geometry of rigid Li-ion battery packaging cases can be cylindrical, since most electrochemical cells of batteries are wound by winding in a cylindrical geometry around a cylindrical mandrel. Prismatic shapes of cases are also made by flattened winding.

[0030] One of the types of rigid cylindrical shaped case, usually manufactured for a high capacity Li-ion accumulator, is illustrated in [Fig.3].

[0031] A rigid prismatic shaped case is also shown in [Fig.4].

[0032] The housing 6 comprises a cylindrical lateral envelope 7, a bottom 8 with a end, a cover 9 at the other end, the bottom 8 and the cover 9 being assembled to the casing 7. The cover 9 is generally crimped at a crimping groove 60. It can also be welded. The cover 9 supports the current output poles or terminals 4, 5. One of the output terminals (poles), for example the negative terminal 5 is welded to the cover 9 while the other output terminal, for example the positive terminal 4, passes through the cover 9 with the interposition of a seal not shown which electrically insulates the positive terminal 4 from the cover.

[0033] Another possible configuration is that one of the output terminals (poles), for example the positive terminal 4 is connected to the electrochemical beam F of the accumulator by the tab forming a collector 40 and projects and passes through the cover 9 with the interposition of a seal not shown which electrically insulates the positive terminal 4 from the cover. The other output terminal, for example the negative terminal 5, is constituted by the bottom and therefore the lateral envelope of the housing 6 which is electrically connected.

[0034] This configuration illustrated in [Fig.5], with the electrochemical bundle wound around a mandrel 10, is for example that which is typically encountered in existing accumulators of 18650, 21700 or 4680 format.

[0035] For each of the three types of accumulator geometry, the latter can be assembled and connected together to form accumulator batteries (also called batteries), in order to increase the energy stored in electrochemical form.

[0036] An assembly of several accumulators is generally called a battery module or module. And by assembling several modules, we obtain a battery pack, also called a pack.

[0037] A battery pack is thus made up of a variable number of accumulators which can reach several thousand which are electrically connected in series and / or in parallel with each other and generally by connection bars, usually called busbars.

[0038] Reference may be made to publication [2] for the constitution of modules and battery packs.

[0039] In all accumulators assembled or not in the form of modules and battery packs, the majority of the materials of interest for recycling are located in the electrochemical bundle of the accumulators.

[0040] Several processes are possible for releasing these materials of interest. The most widely used processes currently are thermal treatments, particularly by pyrolysis, and mechanical treatments, particularly by grinding. These processes are followed by other processes allowing the recycling of the materials of interest.

[0041] The major drawback of existing methods is mixing the electrochemical beam with the other accumulator components and more particularly the casing.

[0042] This mixture then complicates the following steps of the recycling process. This mixture is even more complex when it is carried out on entire modules or battery packs, which by definition integrate many other components, such as busbars, casing layers, etc.

[0043] The materials of interest are then mixed into the materials of these other components, making recycling more complex and expensive.

[0044] There are currently various methods for releasing and separating the electrochemical bundle from a battery case or, more generally, from its packaging. Among these methods, the majority consists of a cutting step, allowing access to the electrochemical bundle, followed by an extraction step which allows the bundle to be separated from its case. This extraction makes it possible to increase the recovery yields of the materials of interest and to facilitate the implementation of a direct recycling process, the so-called active material being able to be directly regenerated in the form of metal oxide without returning to the stage of metal salts.

[0045] Patent CN213782085 discloses a method for releasing and separating the electrochemical bundle for cylindrical accumulators. The first step consists of a cutout allowing access to the bundle during which the two flat end faces of the accumulator casing are cut simultaneously by cutting wheels, the accumulator casing being held via jaws which clamp the housing by matching its outer surface. The second step then consists of extracting the bundle from the rest of the housing by a pushing device with a piston and a movable cylindrical element, in the form of a tip in contact with the bundle, while the rest of the housing is held tight by the jaws. The separation between the bundle and the housing is then well achieved.

[0046] Although the method according to this patent is simple both in terms of the number of steps required and the tooling used and it allows the beam to be kept intact, it has several drawbacks.

[0047] First of all, the tip of the pushing device must necessarily be adapted according to the diameter of the accumulator concerned.

[0048] Then, the two cuts made are restrictive, because:

[0049] - they can alter the mechanical cohesion of the accumulator,

[0050] - for certain types of accumulators, the jaws are then no longer sufficient for keep the accumulator stationary and the actual extraction step can no longer be carried out,

[0051] - they can be carried out within the beam itself and increase the losses of active ingredient linked to this step.

[0052] Finally, this method is not feasible for pouch packaging accumulators and it has not been demonstrated that this method can be implemented on the scale of a module or a battery pack.

[0053] A similar method applied to prismatic accumulators is described in patent CN110299576. The first step consists of a cut allowing access to the bundle during which two lateral faces of the accumulator casing are cut simultaneously over their entire length by blades. The second step then consists of extracting the bundle from the rest of the casing by a pushing device against a fixed blade of the assembly constituted by the rest of the casing with the bundle which cuts into the casing to release the mechanical constraints. At the end of the fixed blade, a scraper allows the cut to be widened. A piston then pushes the electrochemical bundle out of the casing. The separation between the bundle and the casing is then well achieved. The advantages and disadvantages of this method are the same as those of the aforementioned patent CN213782085.

[0054] Patent CN207009601 describes a method for releasing and separating the electrochemical bundle of prismatic accumulators. The first step consists of a cutout allowing access to the bundle during which the upper face of the accumulator housing, which supports the output connectors, is cut by a blade, the accumulator housing being held via jaws which clamp the housing in the direction of its length. The second step then consists of extracting the bundle from the rest of the housing by a clamp which grips the two sides of the bundle within the housing, in the active width direction. This clamp then exerts a pulling force to extract the bundle. The separation between the bundle and the housing is then well achieved.

[0055] This process is advantageous in that only one face is cut, which limits the loss of active material as well as the loss of cohesion of the accumulator.

[0056] However, it has several drawbacks.

[0057] First of all, it is necessary for the electrochemical beam to have significant mechanical strength in order to be able to pull on it.

[0058] In the case of accumulators degraded by aging phenomena, the additional mechanical stresses induced, in particular by brittle electrodes, degradation layers which increase the adhesion between the bundle and the casing, can prevent the bundle from being pinched.

[0059] Finally, this method is not feasible for pouch packaging accumulators and it has not been demonstrated that this method can be implemented on the scale of a module or a battery pack.

[0060] The invention presents a new method for releasing and separating the active core(s). It allows their separation from the other components for all types of batteries (cells, modules and packs) regardless of the cell format (pouch, prismatic and cylindrical).

[0061] There is therefore a need to improve the solutions for separating electrochemical bundles from other components of accumulators that are no longer in use and / or at the end of their life, in particular for all types of geometry (prismatic, cylindrical), packaging (flexible ("pouch") or rigid (case), and for which their initial assembly is within a battery module or a battery pack.

[0062] The aim of the invention is to meet at least part of this need. Statement of the invention

[0063] To do this, the invention relates, in one of its aspects, to a method for extracting an electrochemical bundle from the packaging of an electrochemical accumulator that is no longer in use and / or at the end of its life, with a view to recycling it, the accumulator being integrated into a battery module and / or a battery pack comprising a plurality of electrochemical accumulators, the accumulator initially comprising an electrochemical bundle comprising at least one electrochemical cell consisting of an electrolyte constituent that can be impregnated in an electronic insulating and ion-conducting separator, between a cathode and an anode, a current collector connected to the cathode, a current collector connected to the anode and, a packaging arranged to contain the electrochemical bundle in a sealed manner while being crossed by a portion of the current collectors forming the output terminals, the method comprising the following steps:

[0064] i / cutting an end section of the packaging,

[0065] ii / addition of at least one mechanical reinforcement means suitable for guaranteeing physical cohesion between the accumulators of the module and / or the battery pack,

[0066] iii / cutting the other end section of the packaging, opposite the section cut according to step i / ,

[0067] iv / placing the module and / or the battery pack against a support comprising at least one through opening,

[0068] v / insertion, through an opening delimited by a cut-out section of the packaging, then placing at least one pushing tool in abutment at one end of the electrochemical bundle,

[0069] vi / extraction of the electrochemical bundle from the cut packaging and through the through opening of the support, by pushing the tool against the end of the bundle.

[0070] According to an advantageous variant, steps i / and iii / and where appropriate steps v / to vi / are carried out simultaneously or sequentially for at least part, where appropriate all, of the accumulators of the module and / or the pack. Optimization in terms of cost and speed is achieved if several electrochemical bundles of accumulators are separated from their respective packaging simultaneously.

[0071] When an electrochemical bundle is extracted from an accumulator which is implanted within a module and / or a battery pack, this can lead to a reduction in the mechanical stresses on the adjacent accumulators and thus facilitate their extraction. It is therefore advantageous to choose the order of extraction of the different electrochemical bundles in order to reduce the mechanical stresses and minimize the resulting energy costs.

[0072] Furthermore, to reduce the implementation time of the method, the separation of the electrochemical bundles of unused and / or end-of-life accumulators can be carried out simultaneously within the same module and / or battery pack, by means of a plurality of pushing tools and equipment carrying out this / these simultaneous pushing(s).

[0073] According to a first advantageous configuration of the invention, the packaging is rigid in the form of a box, steps i / and iii / consisting of a step of cutting out an end face of the box.

[0074] According to this configuration, the cutting of the end face is preferably carried out so as to cut the electrical connection between the electrochemical bundle and at least one of the output terminals, preferably the two output terminals arranged on the end face.

[0075] More preferably, the cutting of the end face is carried out without cutting the electrochemical beam.

[0076] Advantageously, when the accumulator is of cylindrical format, the cutting is carried out perpendicular to the central axis (X) of the cylindrical case.

[0077] According to a second advantageous configuration of the invention, the packaging is flexible of the pouch type, step i / comprising at least one step of cutting the side of the packaging through which the output terminals in the form of tabs pass.

[0078] According to an advantageous variant, the mechanical reinforcement means of step ii / is integrated into the support of step iv / .

[0079] Advantageously, the support being an open frame with one of the peripheral edges of smaller dimensions than the other edge so as to delimit the through opening through which the accumulator bundle(s) of the module and / or the battery pack is / are extracted by pushing.

[0080] According to an advantageous embodiment, the method comprises a step of holding the packaging during step i / . Standard mechanical holding equipment may be used, for example a vice, a set of straps or thongs or even a set of screws. This holding guarantees the mechanical holding of the bundle during its cutting and / or the insertion of the anchoring tool and / or the extraction of the bundle. It is of course ensured that the holding leaves accessible the part of the packaging to be cut, an access path for the pushing tool and a clearance path for the extraction of the bundle.

[0081] The invention also relates to a method for recycling an electrochemical beam extracted according to step iii / of the method as described previously.

[0082] According to an advantageous embodiment, the method comprises, prior to one or more chemical treatment steps, one or more steps of separation of the active electrochemical material from the other components of the extracted beam.

[0083] The invention also relates to an electrochemical beam of an electrochemical accumulator extracted according to the method as described previously.

[0084] Thus, the invention essentially consists of a method for separating an electrochemical bundle from its packaging (case or flexible) of an unused and / or end-of-life accumulator, which is integrated within a module and / or a battery pack, comprising the successive cutting of the two packaging end sections, the mechanical reinforcement of the module between the two cuts in order to ensure mechanical cohesion between the accumulators, the pressing against a support, the insertion of a dedicated pushing tool into the electrochemical bundle and then extracting the latter by pushing out of the packaging.

[0085] The mechanical reinforcement can be a vice, a set of straps or thongs, a set of screws, a rigid frame placed around the module and / or the battery pack or even a reinforcement plate to avoid shearing phenomena between accumulators, or a combination of these different means. The mechanical reinforcement is born necessary to ensure the mechanical cohesion of the assembly after the second cut.

[0086] It is specified that prior to implementing the method, each accumulator concerned is preferably electrically deactivated, preferably quickly and safely (electrical discharge, immersion in salt water or any other process allowing discharge). The accumulator therefore no longer presents an electrical risk. Preferably, the state of charge (SOC, anglo-Saxon acronym for "State Of Charge") of the battery, after deactivation, is less than or equal to 0%.

[0087] A state of charge between 0 and 100% corresponds to the classic operation of an accumulator. During a deep discharge to make the accumulator safe, it is discharged below the classic operating range, therefore below a SOC equal to 0%. Depending on the type of accumulator, it can generally go down to -20%, which has the effect of degrading the battery materials.

[0088] Ultimately, the invention provides numerous advantages over the methods according to the state of the art, among which we can cite: - efficient, secure, easy and quick dismantling of an electrochemical battery bundle outside its packaging while ensuring the physical cohesion of the extracted bundle; - a process which makes it possible to separate a beam from an accumulator integrated into a module or battery pack while guaranteeing the mechanical cohesion of the assembly throughout the process; - a method which adapts to any design and / or any electrochemical and / or mechanical state of accumulator: depending on the design and / or the internal mechanical constraints of the accumulator, in particular due to its aging, the choice of one or more pushing tools having different characteristics makes it possible to efficiently separate one or more electrochemical bundles, preferably simultaneously; - the prospect of a high yield for the recycling of accumulators, due to the effective separation obtained using the method according to the invention, between the active electrochemical material and the other accumulator components, before the chemical treatment steps of the recycling itself;

[0089] When the extracted electrochemical beam is that of a Li-ion accumulator: - the negative electrode(s) material is chosen from the group comprising graphite, lithium, silicon or titanate oxide Li4TiO5Oi2; - the positive electrode material(s) is chosen from Lithium cation insertion materials which are generally composite, such as lithium iron phosphate LiFePO4, lithium cobalt oxide LiCoO2, lithium manganese oxide, possibly substituted, LiMn2O4 or transition metal oxide, such as lamellar materials for example, a Li-based material NixMnyCozO2 with x+y+z = 1, such as LiNio.33Mn0.33Coo.3302 or LiNio.8Mno.i Co0.iO2, or a nickel cobalt aluminum oxide material Li-NixCoyAlzO2 with x+y+z = 1, such as LiNi0.sCo0.15Al0.05O2.

[0090] Other advantages and characteristics of the invention will become more apparent upon reading the detailed description of examples of implementation of the invention given by way of illustration and not limitation with reference to the following figures. Brief description of the drawings

[0091] [Fig-1] [Fig.l] is an exploded perspective schematic view showing the different elements of a lithium-ion battery.

[0092] [Fig.2] [Fig.2] is a front view showing a lithium-ion accumulator with its flexible packaging according to the state of the art.

[0093] [Fig.3] [Fig.3] is a perspective view of a state-of-the-art lithium-ion accumulator with its rigid packaging consisting of a cylindrical-shaped case.

[0094] [Fig.4] [Fig.4] is a perspective view of a state-of-the-art lithium-ion accumulator with its rigid packaging consisting of a prismatic-shaped case.

[0095] [Fig.5] [Fig.5] is a perspective view of a state-of-the-art lithium-ion battery configuration with its rigid packaging consisting of a cylindrical-shaped case with a projecting output terminal at one of its longitudinal ends, the other output terminal being formed by the bottom of the case.

[0096] [Fig.6A], [Fig.6B], [Fig.6C], [Fig.6D] Figures 6A to 6D are views in perspective showing the cutting and mechanical reinforcement steps of an example of a method according to the invention, of a plurality of lithium-ion accumulators of cylindrical geometry grouped within a battery module.

[0097] [Fig.7A], [Fig.7B], [Fig.7C], [Fig.7D] Figures 7A to 7D are views in perspective showing the cutting and mechanical reinforcement steps according to figures 6A to 6D on the scale of just one of the accumulators.

[0098] [Fig.8] [Fig.8] is a photographic reproduction of cylindrical accumulators of a battery module having been cut according to a first preceding cutting step of the method of the invention.

[0099] [Fig.9] [Fig.9] is a photographic reproduction of cylindrical accumulators of a part of a battery module having been cut according to a second preceding cutting step of the method of the invention.

[0100] [Fig. 10] [Fig. 10] is a photographic reproduction of cylindrical accumulators of a part of a battery module, illustrating the pushing step of the method of the invention, onto an electrochemical beam for its extraction.

[0101] [Fig. 11] [Fig. 11] is a perspective view of an alternative embodiment of the mechanical reinforcement means, in the form of a plate for implementing the step of supporting the battery module, of the method according to the invention

[0102] [Fig. 12] [Fig. 12] is a perspective view of an alternative embodiment of the mechanical reinforcement means, in the form of a vice for implementing the step of supporting the battery module, of the method according to the invention.

[0103] [Fig. 13] [Fig. 13] is a perspective view showing different variants of through openings of the support for implementing the push extraction step of the method according to the invention.

[0104] [Fig. 14] [Fig. 14] is a perspective view showing a support variant of the method according to the invention.

[0105] [Fig. 15] [Fig. 15] is a perspective view showing the cutting lines of an example of a method according to the invention, of a lithium-ion accumulator of prismatic geometry integrated within a battery module or battery pack. Detailed description

[0106] Figures 1 to 5 relate to different examples of Li-ion accumulators, flexible packaging and accumulator cases as well as a battery pack according to the state of the art.

[0107] These figures 1 to 5 have already been commented on in the preamble and are therefore not commented on further below.

[0108] For the sake of clarity, the same references designating the same elements according to the state of the art and according to the invention are used for all figures 1 to 15.

[0109] Also for the sake of clarity, only a few accumulators A1 to A9 are shown in a battery module M on which the method according to the invention is implemented.

[0110] Throughout the present application, the terms "lower", "upper", "bottom", "top", "below" and "above" are to be understood by reference to vertically arranged Li-ion battery cases.

[0111] Figures 6A to 6C show an example of a module M of a Li-ion, Al, A2,...,A9.....An accumulator battery pack.

[0112] In the illustrated examples, the accumulators A1-A9... illustrated have cylindrical format cases 6, typically 18650 or 21700 format.

[0113] The accumulators A1-A9.. An are arranged parallel to each other.

[0114] The module M may initially comprise a single-piece mechanical clamping and electrical connection assembly, not shown, which may be dismantled before carrying out the steps of the method according to the invention. This clamping assembly may also be left during the steps.

[0115] Step i / : a simultaneous cutting of all the accumulators of the module is carried out with a cutting axis orthogonal to the central axis (X) of the accumulators, i.e. advantageously horizontally, along a first cutting line Ll.

[0116] As shown in Figures 6A and 7A, this first cut of an end face of the accumulators is made along a line L1 at the level of the end face constituting the bottom of the housing 6 of the accumulators. The cutting plane of this line L1 is chosen so as to open the housings 6 while remaining as close as possible to the original bottom, in order to avoid losses of active material.

[0117] Step ii / : at least one mechanical reinforcement means 11 is added, adapted to guarantee physical cohesion between the accumulators A1, A2,..., A9.....An of the module M. This mechanical cohesion is necessary for the subsequent steps as explained below.

[0118] In the example illustrated in figures 6B and 7B, this mechanical reinforcement means 11 can be a strap which goes around the casing of the module, tightening the accumulators A1, A2,..., A9.....

[0119] Step iii / : a simultaneous cutting of all the accumulators of the module is carried out with a cutting axis orthogonal to the central axis (X) of the accumulators, i.e. advantageously horizontally, along a second cutting line L2.

[0120] As shown in Figures 6C and 7C, this second cutting line L2 is in the empty space E so as to cut the electrical connection between the electrochemical bundle F, at the current collector 40 and the output terminal 4. This empty space E is usually called “gaseous sky” because it constitutes the free volume in which the gases resulting from the electrochemical reactions are present. Thus, with this cutting line L2, there is no cutting of the electrochemical bundle F as such.

[0121] Cutting along line L1 or L2 can be carried out using one or more standard tools, such as a blade, a grinding wheel, a wire, a band saw or even a circular saw.

[0122] Step iv / : Following these cuts L1, L2 and installation of the mechanical reinforcement 11, the module M is placed in abutment against a support 12 comprising at least one through opening 120 opposite the accumulator(s) Al,..An from which the electrochemical beam F is to be extracted.

[0123] As illustrated in [Fig.6D], the open support 12 may be a plate. It may also be the bottom of a container. The open support 12 is pressed against the module at one of the previously cut faces of the accumulators.

[0124] The opening(s) 120 of the support 12 may be of dimensions equal to or greater than the diameter of an accumulator or of several accumulators.

[0125] The module M can be movable relative to the support 12 or repositionable on the latter in order to align the beams F to be extracted with the through opening(s) 120 of the support.

[0126] Step v / : The insertion is then carried out, through an opening delimited by a face end of the packaging, previously removed, then abutment of at least one pushing tool at a longitudinal end of the electrochemical bundle F.

[0127] Step vi / : A pushing force P is applied which can be manual or robotic by means of pushing equipment 13, in order to extract the electrochemical bundle(s) F from their housings 6, as shown on the individual scale of a bundle in [Fig. 10], or schematically in [Fig.6D].

[0128] In step i / , the module M can be held by a holding means which can be standard, such as a vice.

[0129] The inventors carried out an experimental test on a battery module M comprising a number n of 1058 cylindrical accumulators, the total weight of which is 87 kg and which has dimensions equal to 100 x 330 x 1700 cm.

[0130] During this experimental test, step ii / of installing mechanical reinforcement was not implemented. In other words, no means of mechanical reinforcement is added around the accumulators.

[0131] The cutting line L1 is made so as to cut all the end faces of the cylindrical Al-An accumulators present in the module M to have access to each of the electrochemical beams F. Following this cutting L1, the entire module M is in a single block, as shown in [Fig.8].

[0132] The cutting line L2 is made in the gaseous sky E present between the electrochemical beam F and the positive terminal 4 of each accumulator.

[0133] Following the two cuts L1 and L2, each beam F is accessible via its two longitudinal ends.

[0134] It can be seen that during the cutting step L2, due to the absence of mechanical reinforcement, the module has broken down into different agglomerates of accumulators as shown in [Fig.9].

[0135] This decomposition into different agglomerates is problematic for industrialization of the process because it is then necessary to carry out the extraction of the active material on each of the agglomerates instead of a single block.

[0136] The extraction is therefore multiplied if the physical integrity of the module after cutting the accumulators cannot be preserved.

[0137] This experimental test therefore makes it possible to validate the need for step ii / of adding mechanical reinforcement between the two cutting steps of the process, on a module with cylindrical accumulators.

[0138] Furthermore, even if there are agglomerates of accumulators, the experimental test made it possible to prove the effectiveness of the method of the invention for extracting by pushing electrochemical bundles F from cylindrical accumulators within a battery module M, as shown in [Fig. 10].

[0139] Advantageously, the open support 12 used for the implementation of step iv / may have been previously implemented as mechanical reinforcement 11 during step ii / . This dual function of the open support 11,12 can make it possible to optimize a process by using a single means for two different functions, as shown diagrammatically in [Fig.11].

[0140] Instead of a mechanical reinforcement strap 11, other mechanical holding means may be used, such as a vice 11' illustrated in [Fig. 12]. Other means, such as a set of straps or strips, a set of screws, a rigid frame to be arranged around the module or even a reinforcement plate to avoid shearing phenomena, may be implemented.

[0141] The through opening(s) in the support 12 may take different shapes, arrangements and dimensions, depending on the type of accumulators. As shown in [Fig.13], these may be: - several circular and adjacent but distinct openings 121, - a single rectangular opening 122 for accumulators of both cylindrical and prismatic format, - several circular and adjacent and adjoining openings 123.

[0142] As mentioned previously, the mechanical reinforcement 11 implemented according to step ii / can advantageously combine the function of mechanical cohesion and open support 12 to allow extraction. For example, the two functions can be combined by using a container which has the functions of, on the one hand, allowing the strapping of the module M to ensure its mechanical cohesion and, on the other hand, allowing extraction according to step vi / via its through opening 120.

[0143] Such a support 12 is shown in [Fig. 14]. It consists of an open frame with one of the peripheral edges 124 of smaller dimensions than the other edge so as to delimit the through opening through which the accumulator bundle(s) of the module and / or the battery pack is / are extracted by pushing.

[0144] With such a support 12 of [Fig.14], the first end face of the bundle cut along the line L1 in step i / is positioned against the face with the edge 124 before carrying out the cutting along the line L2 of step iii / . It is thus possible to carry out the extraction by pushing the electrochemical bundles directly and immediately.

[0145] The method according to the invention can be implemented for prismatic format accumulators A, notably used in electric vehicles.

[0146] As shown in [Fig.15], the cutting of step i / is carried out here along a line of L1 on the side of the upper end face of the housing 6, which supports the output terminals 4, 5. More precisely, the cutting L1 is carried out in the gaseous sky E between the end of the bundle F and the output terminals 4, 5. The tabs 40, 50 connecting the collectors of the bundle F to the output terminals are thus cut.

[0147] The cutting of step iii / is carried out between the end of the beam F and the bottom of the prismatic housing 6.

[0148] The invention is not limited to the examples which have just been described; it is possible in particular to combine characteristics of the examples illustrated within non-illustrated variants.

[0149] Other variants and improvements may be envisaged without departing from the scope of the invention.

[0150] If in the illustrated examples, the output terminal 4 projecting at a longitudinal end of an accumulator case 6 is the positive terminal and the output terminal 5 constituted by a case bottom 6 is the negative terminal, it is obviously possible to implement the invention with reversed terminals, i.e. terminal 4 as the negative terminal and terminal 5 as the positive terminal.

[0151] If in the examples illustrated, the steps of the method are carried out for accumulators with a casing 6 either of cylindrical shape or of prismatic shape, the entire method can be implemented on accumulators with a flexible envelope (“pouch”), the cutting step i / preferably taking place on the side of the envelope from which the tabs forming the output terminals emerge. List of cited references:

[0152] [1]: Diekmann, J., Rothermel, S., Nowak, S., & Kwade, “Recycling of Lithium-Ion Batteries: The LithoRec Process” A. (2018). The LithoRec Way, pages 33-38.

[0153] [2]: Harper, G., Sommerville, R., Kendrick, E., Driscoll, L., Slater, P., Stolkin, R.,... & Anderson, P, “Recycling lithium-ion batteries from electric vehicles”. Nature, (2019). 575(7781), pages 75-86.

Claims

Claims

1. Method for extracting an electrochemical bundle from the packaging of an electrochemical accumulator (A) that is no longer in use and / or at the end of its life, with a view to recycling it, the accumulator being integrated into a battery module and / or a battery pack comprising a plurality of electrochemical accumulators (Al, A2...An), the accumulator initially comprising an electrochemical bundle (F) comprising at least one electrochemical cell consisting of an electrolyte constituent (1) that can be impregnated in an electronic insulating and ionic conductive separator, between a cathode (2) and an anode (3), a current collector (4) connected to the cathode (2), a current collector (5) connected to the anode (3) and, a packaging (6) arranged to contain the electrochemical bundle in a sealed manner while being crossed by a portion of the current collectors (4, 5) forming the output terminals,the method comprising the following steps: i / cutting an end section of the packaging, ii / adding at least one mechanical reinforcement means suitable for ensuring physical cohesion between the accumulators of the module and / or the battery pack, iii / cutting the other end section of the packaging, opposite the section cut according to step i / , iv / pressing the module and / or the battery pack against a support comprising at least one through opening, v / inserting, through an opening delimited by a cut section of the packaging, then placing at least one pushing tool against one end of the electrochemical bundle, vi / extracting the electrochemical bundle from the cut packaging and through the through opening of the support, by pushing the tool against the end of the bundle.

2. Method according to claim 1, steps i / and iii / and where appropriate steps v / to vi / being carried out simultaneously or sequentially for at least part, where appropriate all, of the accumulators of the module and / or the pack.

3. Method according to claim 1 or 2, the packaging being rigid in the form of a box, steps i / and iii / consisting of a step of cutting an end face of the box.

4. A method according to claim 3, the cutting of the end face being made so as to cut the electrical connection between the electrochemical bundle and at least one of the output terminals, preferably the two output terminals arranged on the end face.

5. A method according to claim 4, the cutting of the end face being carried out without cutting the electrochemical beam.

6. Method according to one of claims 3 to 5, the accumulator being of cylindrical format, the cutting being carried out perpendicular to the central axis (X) of the cylindrical case.

7. Method according to one of claims 1 or 2, the packaging being flexible of the pouch type, step i / comprising at least one step of cutting the side of the packaging through which the output terminals in the form of tabs pass.

8. Method according to one of the preceding claims, the mechanical reinforcement means of step ii / being integrated into the support of step iv / .

9. Method according to claim 8, the support being an open frame with one of the peripheral edges of smaller dimensions than the other edge so as to delimit the through opening through which the accumulator bundle(s) of the module and / or the battery pack is / are extracted by pushing.

10. Method according to one of the preceding claims, comprising a step of maintaining the packaging during step i / .

11. Method for recycling an electrochemical beam extracted according to step vi / of the method according to one of the preceding claims.

12. Recycling method according to claim 11, comprising, prior to one or more chemical treatment steps, one or more steps of separation of the active electrochemical material from the other components of the extracted beam.

13. Electrochemical beam of a metal-ion electrochemical accumulator extracted according to the method of one of claims 1 to 10.

14. Electrochemical bundle according to claim 13 of a Li-ion accumulator in which: - the negative electrode(s) material is chosen from the group comprising graphite, lithium, silicon, titanate oxide Li4TiO 5O12; the positive electrode(s) material is chosen from Lithium cation insertion materials which are generally composite, such as lithium iron phosphate LiFePO4, lithium cobalt oxide LiCoO2, lithium manganese oxide, optionally substituted, LiMn2O4 or transition metal oxide, such as lamellar materials, for example, a LiNixMnyCozO2-based material with x+y+z = 1, such as LiNio.33Mno.33Coo.3302 or LiNio.8Mn0.iCo0.i02, or a nickel cobalt aluminum oxide-based material LiNixCoyAlzO2 with x+y+z = 1, such as LiNi0.8Co0.15Al0.05O2-

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