Process for extracting by anchoring then pulling the electrochemical bundle of disused and / or end-of-life electrochemical accumulators, carried out individually or by battery module or battery pack, with a view to their recycling

Abstract

Method for extracting by anchoring and then pulling the electrochemical bundle of disused and / or end-of-life electrochemical accumulators, carried out individually or by battery module or by battery pack, with a view to its 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 metal-ion accumulator, consisting of making at least one cut in the packaging, anchoring a dedicated tool in the electrochemical bundle and then extracting the latter by pulling from the packaging. Figure for the abstract: fig.13

Description

Title of the invention: Method of extraction by anchoring then traction of the electrochemical bundle of electrochemical accumulators no longer in use and / or at the end of their life, carried out individually or by battery module or by battery pack, with a view to its 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 needed 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] Rigid Li-ion battery packaging cases can be cylindrical, electrochemical cells of the batteries are wound by winding according to a cylindrical geometry around a cylindrical mandrel. They can also be prismatic in shape 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 method is advantageous in that only one face is cut, which makes it possible to limit 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 end-of-life and / or end-of-life accumulators, in particular for all types of geometry (prismatic, cylindrical), packaging (flexible ("pouch") or rigid (case), and whatever their initial assembly, i.e. individual, 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 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 out at least one section of the packaging,

[0065] ii / insertion, through the opening delimited by the cut-out section of the packaging then anchoring at least one anchoring tool within the electrochemical bundle,

[0066] iii / extraction of the electrochemical bundle from the cut packaging, by pulling the tool anchored within it.

[0067] According to an advantageous variant, the anchoring tool is a harpoon or a threaded tip or a helical bit. The characteristics of a harpoon or a threaded tip can be adapted according to the type of accumulator from which the electrochemical beam extraction is to be carried out. For a harpoon, this may be the pitch and number of teeth, the shape of the teeth, the height of the engagement tip, the angle of the tooth exit, the tooth angle, the angle of the engagement tip, the working length (anchoring) of the tool and the thickness of the harpoon. For a threaded tip, this may be the angle of the tooth, the pitch of the helix, the angle of the engagement tip, the diameter of the body of the tip and its external diameter, the working length (anchoring) of the tool. One or more helix-shaped wicks, or any other tool that can penetrate and anchor itself in an electrochemical battery bundle, can also be considered.The penetration of the extraction tool into the beam material depends on the type of tool used. A harpoon is preferably introduced linearly into an electrochemical beam while threaded tip or helical bit type tools are preferably screwed into the material.

[0068] According to an advantageous embodiment, the method comprises a step of holding the packaging during one and / or the other of steps i / to iii / . 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 battery 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 anchoring tool and a clearance path for the extraction of the bundle.

[0069] According to a first advantageous configuration of the invention, the packaging is rigid in the form of a box, step i / comprising at least one step of cutting an end face of the box.

[0070] 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.

[0071] More preferably, the cutting of the end face is carried out without cutting the electrochemical beam.

[0072] Advantageously, when the accumulator is of cylindrical format, the cutting is carried out perpendicular to the central axis (X) of the cylindrical case.

[0073] According to a second advantageous configuration of the invention, the packaging is flexible 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.

[0074] Depending on the applications, step i / may comprise at least one cutting step within the electrochemical bundle. This may be advantageous in particular when significant stresses appear on the electrochemical bundle, for example when the accumulators have aged. Thus, this cutting makes it possible to release part of the stress exerted by the packaging of an accumulator and / or neighboring accumulators on the electrochemical bundle. This cutting may also make it possible to limit the tensile force to be applied to the anchoring tool having penetrated to extract the electrochemical bundle from its packaging.

[0075] According to an advantageous embodiment variant, the electrochemical bundle integrates at least one component in a continuous form, the method comprising a step iv / of unwinding the bundle around an unwinding axis formed by the anchoring tool held anchored in the bundle. The different geometries concerned may be for a flattened, cylindrical, Z-folded electrochemical bundle, etc. Once the extraction has been carried out, the anchoring tool having penetrated the bundle serves as an axis of rotation for unwinding said bundle. The end of the winding can be pulled and the entire bundle can then be unwound. This additional step makes it possible to initiate the separation of the active material by beginning to promote their release. This step can be combined with a step of separating the electrodes, since the anode, cathode and separator can be separated from each other during the unwinding of the electrochemical bundle.Thus, following the process, the anode, the cathode and the separator are physically well separated from each other.

[0076] According to an advantageous configuration, the accumulator can be integrated into a battery module and / or a battery pack comprising a plurality of metal-ion electrochemical accumulators, steps i / to iii / and where appropriate step iv / being carried out simultaneously or sequentially for at least some, where appropriate all, of the accumulators of the module and / or the pack.

[0077] We optimize in terms of cost and speed since we simultaneously separate several electrochemical bundles of accumulators from their respective packaging.

[0078] 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. 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.

[0079] In addition, to reduce the implementation time of the method, the separation of the electrochemical bundles of used and / or end-of-life accumulators can be carried out simultaneously within the same module and / or battery pack, using a plurality of anchoring tools and equipment carrying out their simultaneous traction.

[0080] Advantageously, the anchoring tool(s) implemented in step ii / may be identical or different for at least part, if applicable all, of the accumulators of the module and / or pack from which the electrochemical bundle is to be extracted. This makes it possible to adapt as best as possible to the types of accumulators, their format and their characteristics.

[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 a metal-ion 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 a metal-ion accumulator that is no longer in use and / or at the end of its life, consists of making at least one cut in the packaging, anchoring a dedicated tool in the electrochemical bundle and then extracting the latter by pulling it out of the packaging.

[0085] 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 method allowing discharge). The accumulator therefore no longer presents an electrical risk. Preferably, the state of charge (SOC, an English acronym for "State Of Charge") of the battery, after deactivation, is less than or equal to 0%.

[0086] 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.

[0087] 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 method which makes it possible to separate a beam from an accumulator whether it is implemented individually or integrated into a module or a battery pack; - 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 anchoring tools having different characteristics makes it possible to effectively 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; - the possibility of reusing the anchoring tools: following the extraction step üi / , the electrochemical bundle can be held by a mechanical system, such as a vice, clamping jaws, and the tip can then be unscrewed and therefore removed from the bundle for later use.

[0088] 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(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, possibly substituted, LiMn2O4 or transition metal oxide, such as lamellar materials for example, a material based on Li-NixMnyCozO2 with x+y+z = 1, such as LiNio.33Mn0.33Co0.3302 or LiNio.8Mno.i Co0.iO2, or a material based on nickel cobalt aluminum oxide type Li-NixCoyAlzO2 with x+y+z = 1, such as LiNi0.8Co0.15Al0.05O3.

[0089] 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

[0090] [Fig-1] [Fig.l] is an exploded perspective schematic view showing the different elements of a lithium-ion battery.

[0091] [Fig.2] [Fig.2] is a front view showing a lithium-ion accumulator with its flexible packaging according to the state of the art.

[0092] [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.

[0093] [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.

[0094] [Fig.5] [Fig.5] is a perspective view of a lithium-ion battery configuration according to the state of the art 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 constituted by the bottom of the case.

[0095] [Fig.6A], [Fig.6B], [Fig.6C] Figures 6A to 6C are perspective views showing the different cutting 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.

[0096] [Fig.7A], [Fig.7B], [Fig.7C] Figures 7A to 7C are perspective views showing the different cutting stages according to figures 6A to 6C on the scale of a single accumulator.

[0097] [Fig.8] [Fig.8] is a photographic reproduction of cylindrical accumulators of a battery module having been cut according to a previous step of the method of the invention, [Fig.8] showing an example of anchoring points of anchoring tools within the accumulators, for the extraction of the electrochemical bundles from their casings.

[0098] [Fig.9][Fig.10] Figures 9 and 10 are respectively perspective side, sectional and detailed views of an example of an anchoring tool in the form of a harpoon for implementing the anchoring step according to the invention.

[0099] [Fig. 1 l][Fig. 12] Figures 11 and 12 are side, sectional and detailed perspective views of an example of an anchoring tool in the form of a threaded tip for implementing the anchoring step according to the invention.

[0100] [Fig. 13] [Fig. 13] is a photographic reproduction showing the extraction by traction by means of traction equipment of an anchoring tool previously inserted into a cylindrical case battery bundle from a battery module in which it is initially implanted.

[0101] [Fig. 14] [Fig. 14] is a photographic reproduction showing the electrochemical beam once extracted according to the step of [Fig.13].

[0102] [Fig. 15] [Fig. 15] is a perspective view showing a cutting step of an example of a method according to the invention, of a lithium-ion accumulator of prismatic geometry.

[0103] [Fig. 16] [Fig. 16] is a photographic reproduction of a prismatic accumulator having been cut according to a previous step of the method of the invention, [Fig. 16] showing a first example of anchoring points of anchoring tools within the accumulator, for the extraction of its electrochemical beam from its casing.

[0104] [Fig. 17] [Fig. 17] is a photographic reproduction of a prismatic accumulator having been cut according to a previous step of the process of the invention, the [Fig. 16] showing a second example of anchoring points of anchoring tools within the accumulator, for the extraction of its electrochemical beam from its casing.

[0105] [Fig. 18] [Fig. 18] is a photographic reproduction showing two electrochemical bundles of prismatic accumulators once extracted from their cases.

[0106] [Fig. 19] [Fig. 19] is a photographic reproduction showing an advantageous variant of an additional step of the method according to the invention, consisting of unwinding the electrochemical beam around its anchoring tool, once the beam has been extracted from the housing. Detailed description

[0107] 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.

[0108] These figures 1 to 5 have already been commented on in the preamble and are therefore not commented on further below.

[0109] 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 19.

[0110] 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.

[0111] 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.

[0112] Figures 6A to 6C show an example of a module M of a Li-ion, Al, A2,...,A9.....An accumulator battery pack.

[0113] In the illustrated examples, the accumulators A1-A9... illustrated have cylindrical format cases 6, typically 18650 or 21700 format.

[0114] The accumulators A1-A9.. An are arranged parallel to each other.

[0115] 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.

[0116] As an experimental test, the steps of the method which will be described were carried out 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.

[0117] Step i / : at least one simultaneous cutting of all the batteries is carried out module modulators with a cutting axis orthogonal to the central axis (X) of the accumulators, or advantageously horizontal.

[0118] In this test, different cutting configurations allowing access to the electrochemical beam of each accumulator were validated.

[0119] As shown in Figures 6A and 7A, a first possibility of cutting an end face of the accumulators is carried out along a line L1 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 L1, there is no cutting of the electrochemical bundle F as such.

[0120] As shown in Figures 6B and 7B, a second possibility of cutting an end face of the accumulators is carried out along a line L2 at the end face constituting the bottom of the housing 6 of the accumulators. The cutting plane of this line L2 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.

[0121] As shown in Figures 6C and 7C, a third cutting possibility is made along a line L3 substantially in the middle of the height of the accumulators. This third cutting L3 certainly results in a duplication of the following extraction steps and also possibly a loss of active material, but it makes it possible to release part of the stress exerted by the housing 6 on the bundle F that it houses. Thus this cutting along L3 can be advantageous in the case of significant stresses on the electrochemical bundle, for example when the accumulators have aged.

[0122] Cutting along line L1, L2 or L3 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.

[0123] This test makes it possible to validate step i / of cutting the process, on a module with cylindrical accumulators.

[0124] Step ii / : Following these cuts, an anchoring tool is inserted at an anchoring point PI within each of the accumulator bundles F that we wish to extract.

[0125] As shown in [Fig.8], this anchoring point PI is preferably at the center of the cylinder, i.e. on the central axis X of the electrochemical beam.

[0126] A first advantageous anchoring tool is shown in Figures 9 and 10: it is a harpoon 11 comprising a non-active part forming a base 110 and an active part 111 comprising one or more teeth or points 112. The characteristics of the harpoon 11 which are mentioned in [Fig. 10] can be adapted according to the type of beam electrochemical F, such as tooth pitch and number, tooth shape, engagement tip height, tooth exit angle, tooth angle, engagement tip angle, tool working length and tool working part thickness.

[0127] A second advantageous anchoring tool is shown in Figures 11 and 12: it is a threaded tip 12 comprising a non-active part forming a base 120 and an active part 121 comprising a thread and the end of which is an engagement tip 122. The characteristics of the threaded tip 12 which are mentioned in [Fig. 12] can be adapted according to the type of electrochemical beam F, such as the angle of the thread, the pitch of the helix, the angle of the engagement tip, the diameter of the screw body and the outside diameter of the tool, the working length of the tool.

[0128] In the experimental test, a threaded tip is screwed into the center PI of each electrochemical beam F so as to achieve the desired anchoring. For example, a screw length of 50mm allows good anchoring of the tool 12 penetrating into the active material of the beam F to be extracted.

[0129] Step iii / : A traction force is applied which can be manual by means of traction equipment 13, in order to extract the electrochemical bundles F from their housings 6, as shown on the individual scale of a bundle in [Fig. 13].

[0130] An example of an extracted beam F still penetrated by a threaded tip 12 which is connected to the extraction equipment 13 is shown in [Fig. 14].

[0131] The cutting line L3, which is optionally made in the center of a beam F, can make it possible to limit the traction force to be applied to the anchoring tool 11 or 12 to extract the beam F.

[0132] In all of steps i / to iii / , the module M can be held by a holding means which can be standard, such as a vice 14 as shown in [Fig. 13].

[0133] The results of the tests carried out based on the cuts made are: - an extraction carried out with respective traction forces of 390, 460 and greater than 500 N in the case of the cutting line L1; - an extraction carried out with traction forces in the case of the cutting line L2 substantially identical to the case of the line L1; - an extraction carried out with respective tensile forces of 466, 332, 367 and 87, 166 N in the case of the cutting line L3, the variations observed in the tensile forces to be applied being due to the difference in the distance between the line L3 and one or other of the end faces of the housing 6.

[0134] In the three cutting line configurations L1, L2, L3, after removal of the components from the housing and the cut output terminals, the extraction of an apparent beam F was successfully carried out.

[0135] The tests therefore make it possible to prove the effectiveness of the method of the invention for extracting electrochemical beams F from cylindrical accumulators within a battery module M.

[0136] Another example of embodiment of the method according to the invention is shown in Figures 15 to 19 for accumulators A of prismatic format, notably used in electric vehicles.

[0137] Step i / : As shown in [Fig. 15], the cutting 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 out. The cut out part is removed.

[0138] Step ii / : Two threaded tip type tools 12 are screwed into the visible beam F.

[0139] A first test consisted of inserting the threaded tips 12 into anchoring points P2, equidistant from the lateral edges of the same side of a prismatic beam F, as shown in [Fig. 16]. A tensile force was applied simultaneously to the two threaded tips 12 while holding the prismatic housing in a vice 14. The extraction of the beam F was effectively carried out. The value of the extraction force could not be measured because this force is greater than the range of the dynamometer used, i.e. greater than 500 N.

[0140] A second test consisted of inserting the threaded tips 12 into anchor points P2, P3, opposite each other in the diagonal of a prismatic beam F, as shown in [Fig. 17]. A tensile force was applied simultaneously to the two threaded tips 12 while holding the prismatic housing in a vice 14. The extraction of the beam F was effectively carried out. The value of the extraction force could not be measured because this force is greater than the range of the dynamometer used, i.e. greater than 500 N.

[0141] An extraction of several F beams can be carried out simultaneously for several prismatic accumulators, as shown in [Fig. 18], for example with a connecting bar 130 connecting the traction equipment to several threaded points 12 each anchored in a different F beam.

[0142] [Fig. 19] shows an advantageous variant of the method according to the invention, with once the extraction of an electrochemical beam has been carried out, the use of the anchoring tool 12 always maintained within the beam, as an axis of rotation of the latter to unwind its constituents. Thus, the end of the winding forming the beam F can be pulled. This makes it possible to initiate the separation of the active material by starting to promote its release with a view to recycling. As shown in the [Fig. 19], this process can be combined with a step of separating electrodes 2, 3 and the separator.

[0143] Thus, the separator 1, the cathode 2, the anode 3 can be separated from each other during the unwinding of the beam F.

[0144] 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.

[0145] Other variants and improvements may be envisaged without departing from the scope of the invention.

[0146] If in the examples illustrated, 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.

[0147] 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:

[0148] [1]: Diekmann, J., Rothermel, S., Nowak, S., & Kwade, “Recycling of Lithium-Ion Batteries: The LithoRec Process” A. (2018). The LithoRec Way, pages 33-38.

[0149] [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 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 ion-conducting 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 with sealing while being crossed by a part of the current collectors (4, 5) forming the output terminals, the method comprising the following steps: i / cutting at least one section of the packaging, ii / insertion,through the opening delimited by the cut section of the packaging then anchoring at least one anchoring tool within the electrochemical bundle, iii / extraction of the electrochemical bundle from the cut packaging, by pulling the tool anchored within it.,

2. A method according to claim 1, the anchoring tool being a harpoon or a threaded point or a helical bit.

3. A method according to claim 1 or 2, comprising a step of holding the packaging during one and / or other of steps i / to iii / .

4. Method according to one of the preceding claims, the packaging being rigid in the form of a box, step i / comprising at least one step of cutting an end face of the box.

5. Method according to claim 4, the cutting of the end face being 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.

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

7. Method according to one of claims 4 to 6, the accumulator being of cylindrical format, the cutting being carried out perpendicular to the central axis (X) of the cylindrical case.

8. Method according to one of claims 1 to 3, the packaging being flexible of the pouch type, step i / comprising at least one step of cutting the side of the package through which the output terminals in the form of tabs pass through.

9. Method according to one of the preceding claims excluding claim 6, step i / comprising at least one cutting step within the electrochemical beam.

10. Method according to one of the preceding claims, the electrochemical beam integrating at least one component in a continuous form, the method comprising a step iv / of unwinding the beam around an unwinding axis formed by the anchoring tool held anchored in the beam.

11. Method according to one of the preceding claims, the accumulator being integrated into a battery module and / or a battery pack comprising a plurality of metal-ion electrochemical accumulators (Al, A2...A30), steps i / to iii / and where appropriate step iv / being carried out simultaneously or sequentially for at least some, where appropriate all, of the accumulators of the module and / or the pack.

12. Method according to claim 11, the anchoring tool(s) implemented in step ii / being identical or different for at least part, if applicable all, of the accumulators of the module and / or pack from which the electrochemical bundle is to be extracted.

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

14. Recycling method according to claim 13, 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.

15. Electrochemical beam of a metal-ion electrochemical accumulator extracted according to the method of one of claims 1 to 12.

16. Electrochemical bundle according to claim 15 of a Li-ion accumulator in which: - the negative electrode(s) material is chosen from the group comprising graphite, silicon, lithium, 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 by 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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