Battery electrode material recovery

Abstract

The invention provides a method of separating an electrode material from an electrode, the method comprising the steps of: a. Providing an electrode comprising an electrode material adhered to a 5 current collector; b. Adhering the electrode material to a frozen solid; c. Delaminating the current collector from the electrode material when the electrode material is adhered to the frozen solid to provide a free electrode material and a free current collector; and 10 d. Recovering the free electrode material.

Description

[0001] BATTERY ELECTRODE MATERIAL RECOVERY

[0002] Technical Field of the Invention

[0003] The present invention relates to methods of separating electrode materials from electrodes, methods of separating battery electrode materials from batteries, and methods of recycling batteries.

[0004] The project leading to this application has received funding from the European Union’s

[0005] Horizon 2020 research and innovation programme under grant agreement No 963542.

[0006] Background to the Invention

[0007] Battery recycling and reuse have become a worldwide concern in recent years, especially with the increasing development of electric vehicles.

[0008] However, electrode material recycling and reclamation are notoriously challenging and expensive due to the complex battery structure and chemistries involved.

[0009] Separation of electrode materials (such as black mass) from current collectors in a battery electrode is a critical step in the recovery of materials from batteries. The recycling efficiency, as well as the energy consumption of recovery methods are heavily dependent on this separation step.

[0010] Several methods have been trialled to achieve the separation of electrode materials from current collectors in a battery electrode, including high energy ultrasound methods, thermal treatment methods (using high temperatures), acid delamination methods, organic solvent-based methods, and other mechanical separation methods. The above methods all suffer from various disadvantages. High energy ultrasound methods, for instance, result in impurities remaining in separation products, due to the high energy delamination process used. High temperature thermal treatment methods can cause decomposition of components of the electrode material, such as PVDF binders, which can cause production of toxic substances such as HF. Acid delamination methods can cause metals to dissolve from current collectors and active materials of the electrode materials, which is disadvantageous. Organic solvent-based methods, such as those making use of solvents such as A-methyl-2-pyrrol idone (NMP) or dimethylformamide (DMF), whilst well-known, often involve further lengthy solvent treatment and reclamation steps; and the use of volatile and toxic solvents limits their usage in large- scale production. Mechanical separation methods often produce high levels of impurities in waste streams.

[0011] In addition, the above methods often cause crystal structure and morphology changes in the reclaimed materials, which can result in further cost and effort to “recondition” the reclaimed materials to make them suitable for reuse in a battery.

[0012] Hence, there exists a need for new methods for separating electrode materials from electrodes that overcome or mitigate at least one problem of the prior art. In particular, there is a need for new methods that are environmentally friendly, sustainable, cost- effective, efficient, and scalable.

[0013] It is an aim of embodiments of the present invention to overcome or mitigate at least one problem of the prior art, whether expressly described herein or not.

[0014] Summary of the Invention According to a first aspect of the invention, there is provided a method of separating an electrode material from an electrode, the method comprising the steps of:

[0015] (a) Providing an electrode comprising an electrode material adhered to a current collector;

[0016] (b) Adhering the electrode material to a frozen solid;

[0017] (c) Delaminating the current collector from the electrode material when the electrode material is adhered to the frozen solid to provide a free electrode material and a free current collector; and

[0018] (d) Recovering the free electrode material.

[0019] Without wishing to be bound by theory, the delamination method of the invention involves using frozen solids to benefit from thermal conductivity differences between the frozen solid and electrode materials to allow for delamination of electrode materials from current collectors through the formation of a bond between electrode materials and the frozen solid, which is stronger than the bond between the electrode materials and current collectors in an electrode.

[0020] The inventive method allows for rapid, high efficiency delamination of electrodes with little or no damage caused to electrode components in the process. Obtained free electrode materials and free current collectors can also be directly recycled following the inventive delamination method without the need for subsequent complicated separation steps, as is the case in many methods of the prior art. This simplifies the recycling process and greatly minimises greenhouse gas emissions compared to many routes of the prior art for direct recycling, making the method of the invention highly environmentally friendly. Due to the physical nature of the delamination method of the invention and the fact that only a frozen solid is required, no volatile organic components are released, contrary to many methods of the prior art. In addition, the delamination method of the invention is highly flexible, and due to the chemically non-destructive conditions used, virtually any type of electrode material may be delaminated from a current collector using this method.

[0021] Compared to many delamination methods of the prior art, the method of the invention offers: high delamination yield; high purity of recovered materials with original morphologies and sizes and which can be directly recycled; limited waste and virtually no contamination; good current collector grade for recovery and recycling or even direct reuse; and a binder agnostic approach (capable of delaminating electrode materials comprising both water-soluble and non-water-soluble binders).

[0022] In some embodiments, step (a) comprises isolating the electrode from a battery. References to batteries in the specification also include references to cells.

[0023] The step of isolating the electrode from a battery may comprise separating the electrode from one or more other components of the battery. The step of isolating the electrode from a battery may comprise disassembling the battery and separating the electrode from one or more other components of the battery. At least one other component of the battery may be independently selected from the group consisting of: a cell container, a separator, an electrolyte, and combinations thereof.

[0024] The battery may be a non-rechargeable or a rechargeable battery.

[0025] In some embodiments, the battery is independently selected from the group comprising: an alkali metal ion battery, a nickel-based battery, a zinc -based battery, a lead-acid battery, a supercapacitor, an aluminium ion battery, and an alkaline battery. In preferred embodiments, the battery is an alkali metal ion battery. In some embodiments, the battery is an alkali metal ion battery that is independently selected from the group consisting of: a Na-ion battery, a Li-ion battery, a potassium ion battery, a rubidium ion battery, and a caesium ion battery. In some preferred embodiments, the battery is a Na-ion battery or a Li-ion battery.

[0026] In some embodiments, the battery is a waste battery. In some embodiments, the battery is an end-of-life battery.

[0027] In some embodiments, the battery may be a scrap battery. In some embodiments, the waste battery may not comprise an electrolyte.

[0028] In some embodiments, the electrode is a scrap electrode. The scrap electrode may be produced during an electrode manufacturing process. The scrap electrode may comprise waste from an electrode manufacturing process. In some embodiments, step (a) comprises recovering a scrap electrode from the products of an electrode manufacturing process.

[0029] In some embodiments, step (a) further comprises the step of pre-treating the electrode with a solvent. The solvent pre-treatment step may comprise contacting the electrode with the solvent, preferably contacting at least part of an outer surface area of the electrode with the solvent. The solvent pre-treatment step may comprise contacting the entire outer surface area of the electrode with the solvent. The solvent pre-treatment step may comprise submerging the electrode in a solvent.

[0030] The solvent pre-treatment step may be performed for at least 1 hour, or at least 2, 3, 4, 5, 10, 15, or at least 20 hours. The solvent pre-treatment step may be performed for at least one day. The electrode may be submerged in the solvent for the time periods above. The pre-treatment solvent may comprise an alcohol. The alcohol may be a Cl -CIO alcohol, or a C1-C5, or a C1-C3 solvent. The pre-treatment solvent may comprise isopropyl alcohol.

[0031] In some embodiments, step (a) further comprises the step of pre-treating the electrode with a surfactant. The surfactant pre-treatment step may comprise contacting the electrode with the surfactant, preferably contacting at least part of an outer surface area of the electrode with the surfactant. The surfactant pre-treatment step may comprise contacting the entire outer surface area of the electrode with the surfactant. The surfactant pre-treatment step may comprise submerging the electrode in a surfactant.

[0032] The surfactant pre-treatment step may be more useful in embodiments wherein the electrode comprises electrolyte deposition, preferably on a surface thereof. The electrode may comprise solid electrolyte interphase (SEI) or cathode electrolyte interphase (CEI) deposition. The electrode may be a waste or scrap electrode.

[0033] The surfactant pre-treatment may increase the wettability of the electrode surface, which may involve removing at least part of the electrolyte deposition from the surface.

[0034] In some embodiments, step (a) further comprises the step of drying the electrode. The drying step may be performed after the solvent and / or surfactant pre-treatment step.

[0035] The drying step may comprise heating the electrode. The electrode may be heated to a temperature of at least 40 °C, or at least 50, or at least 60 °C. The drying step may be performed for at least 1 hour, or at least 2, 3, 4, 5, 10, 15, or at least 20 hours. The drying step may be performed for at least one day.

[0036] The drying step may be performed under low pressure. The drying step may comprise heating the electrode under low pressure. The electrode may be an anode. The electrode may be a cathode.

[0037] In some embodiments, the electrode comprises a layered arrangement of the electrode material and the current collector. In some embodiments, the electrode comprises a layer of the electrode material adhered to a layer of the current collector.

[0038] In some embodiments, the electrode may comprise more than one layer of the electrode material. In some embodiments, the electrode may comprise more than one layer of the current collector.

[0039] The electrode may comprise two layers of electrode material held on either side of a layer of the current collector.

[0040] In some embodiments, the current collector comprises or consists of a metal. The current collector may comprise or consist of a metal that is independently selected from the group consisting of: aluminium, copper, nickel, titanium, iron, and combinations and / or alloys thereof. In some preferred embodiments, the current collector comprises aluminium and / or copper.

[0041] In some embodiments, the current collector comprises or consists of carbon or a carbonbased material.

[0042] In some embodiments, the current collector comprises a foil, which may be a metal foil. The foil may be carbon coated. The foil may be a meshed foil.

[0043] The current collector may comprise a foam, which may be a metal foam.

[0044] In some embodiments, the electrode material comprises at least one binder. At least one binder may be water-soluble and / or non-water-soluble. At least one binder may be a polymeric binder. The electrode material may comprise at least one water-soluble binder that is a water- soluble polymer. In some embodiments, the electrode material comprises at least one water-soluble binder that is independently selected from the group consisting of: carboxymethyl cellulose, styrene butadiene rubber, polyvinyl alcohol, polyacrylic acid, polyethylene glycol, and salts, derivatives, and combinations thereof.

[0045] The electrode material may comprise at least one non-water-soluble fluorine containing binder. The electrode material may comprise at least one non-water-soluble binder that is independently selected from the group consisting of: polyvinylidene fluoride, polytetrafluoroethylene, a polyimide, ethylene propylene diene monomer, an epoxy resin, and derivatives and combinations thereof. In some preferred embodiments, the electrode material may comprise a polyvinylidene fluoride (PVDF) binder.

[0046] In some embodiments, the electrode material comprises at least one composite binder. At least one composite binder may be a water-soluble and / or non-water-soluble composite binder.

[0047] In some preferred embodiments, the electrode material comprises a water-soluble composite binder comprising carboxymethyl cellulose and styrene butadiene rubber (CMC-SBR). The carboxymethyl cellulose and styrene butadiene rubber may be present in the composite binder in a weight ratio of between 5:1 to 1:5 carboxymethyl cellulose to styrene butadiene rubber, or between 4: 1 to 1 :4, or between 3 : 1 to 1 :3, or between 2:1 to 1:2 carboxymethyl cellulose to styrene butadiene rubber.

[0048] In some embodiments, the electrode material comprises an active material that comprises an alkali metal. In such embodiments, the active material may be alkali metal-based. The electrode material may comprise an active material that comprises carbon. In such embodiments, the active material may be carbon-based. The electrode active material may be independently selected from the group consisting of: graphite, hard carbon, soft carbon, carbon nanotubes, graphene, activated carbon, carbon aerogels, and combinations thereof.

[0049] In some embodiments, the electrode material comprises an intercalation compound active material. The intercalation compound active material may be independently selected from the group consisting of: a transition metal oxide, a layered compound, a chalcogenide, a phosphate, an organic compound, a cyanide-based compound, and combinations thereof. At least one transition metal oxide may comprise a niobium oxide. The layered compound intercalation compound may comprise a layered oxide. The cyanide-based intercalation compound may be independently selected from the group consisting of: Prussian white, Prussian blue, and derivatives and / or combinations thereof.

[0050] In some embodiments, the electrode active material may comprise a titanium oxide, and may comprise a lithium titanium oxide, which may comprise IrifTisO .

[0051] In some embodiments, the electrode active material may comprise silicon.

[0052] In some embodiments, the electrode active material may comprise a metal, and may comprise a metal alloy.

[0053] In some embodiments, the electrode material comprises at least one conductive additive.

[0054] At least one conductive additive may comprise carbon. Such a conductive additive may be carbon-based. At least one carbon-based conductive additive may be independently selected from the group consisting of: carbon black, graphene, carbon nanotubes, carbon fibres, and combinations thereof. At least one conductive additive may comprise a metal. At least one conductive additive may comprise a metal powder and / or a metal oxide.

[0055] At least one conductive additive may comprise a conductive polymer. At least one conductive polymer may be independently selected from the group consisting of: polyaniline, polypyrrole, polythiophene, poly(3,4-ethylenedioxythiophene), polyacetylene, and combinations thereof.

[0056] In some embodiments, the active material is present in a total concentration of at least 50 wt.% of the electrode material, or at least 55, 60, 65, 70, 75, 80, 85, or at least 90 wt.% of the electrode material, or at least 95, 96, 97, 98, 99, 99.1, 99.2, 99.3, 99.4, 99.5, 99.6, 99.7, 99.8, or at least 99.9 wt.% of the electrode material. In some embodiments, the active material is present in a total concentration of substantially 100% of the electrode material. In some embodiments, the active material is present in a total concentration of no greater than 99 wt.% of the electrode material, or no greater than 98, 97, or no greater than 96 wt.% of the electrode material. The active material may be present in a total concentration of between 50-99 wt.% of the electrode material, or between 60-99, 70-99, 80-99, 90-99, 90-97, 92-97, or between 93-96 wt.% of the electrode material.

[0057] In some embodiments, the binder is present in a total concentration of at least 0.2 wt.% of the electrode material, or at least 0.4, 0.6, 0.8, 1, 1.5, 2, or at least 2.5 wt.% of the electrode material. In some embodiments, the binder is present in a total concentration of no greater than 10 wt.% of the electrode material, or no greater than 9, 8, 7, 6, 5, 4, or no greater than 3 wt.% of the electrode material. The binder may be present in a total concentration of between 0.2-10 wt.% of the electrode material, or between 0.4-8 wt.%, or between 0.6-7 wt.%, or between 0.8-6 wt.%, or between 1-5 wt.%, or between 2-4 wt.% of the electrode material.

[0058] In some embodiments, the conductive additive is present in a total concentration of at least 0.2 wt.% of the electrode material, or at least 0.4, 0.6, 0.8, or at least 1 wt.% of the electrode material. In some embodiments, the conductive additive is present in a total concentration of no greater than 10 wt.% of the electrode material, or no greater than 9, 8, 7, 6, 5, 4, or no greater than 3 wt.% of the electrode material. The conductive additive may be present in a total concentration of between 0.2-10 wt.% of the electrode material, or between 0.4-7 wt.%, or between 0.6-5 wt.%, or between 0.8-4 wt.% of the electrode material.

[0059] In some embodiments, the active material is present in a total concentration of between 50-99 wt.% of the electrode material; and the binder is present in a total concentration of between 0.2-10 wt.%, or between 0.6-7 wt.%, or between 0.8-6 wt.%, or between 2-4 wt.% of the electrode material. The active material may be present in a total concentration of between 80-99 wt.% of the electrode material; and the binder may be present in a total concentration of between 0.2-10 wt.%, or between 0.6-7 wt.%, or between 0.8-6 wt.%, or between 2-4 wt.% of the electrode material. The active material may be present in a total concentration of between 90-99 wt.% of the electrode material; and the binder may be present in a total concentration of between 0.2-10 wt.%, or between 0.6-7 wt.%, or between 0.8-6 wt.%, or between 2-4 wt.% of the electrode material. The active material may be present in a total concentration of between 93-96 wt.% of the electrode material; and the binder may be present in a total concentration of between 0.2-10 wt.%, or between 0.6-7 wt.%, or between 0.8-6 wt.%, or between 2-4 wt.% of the electrode material. In some embodiments, the conductive additive is present in a total concentration of between 0.2-10 wt.% of the electrode material; and the binder is present in a total concentration of between 0.2-10 wt.%, or between 0.6-7 wt.%, or between 0.8-6 wt.%, or between 2-4 wt.% of the electrode material. The conductive additive may be present in a total concentration of between 0.4-7 wt.% of the electrode material; and the binder may be present in a total concentration of between 0.2-10 wt.%, or between 0.6-7 wt.%, or between 0.8-6 wt.%, or between 2-4 wt.% of the electrode material. The conductive additive may be present in a total concentration of between 0.6-5 wt.% of the electrode material; and the binder may be present in a total concentration of between 0.2-10 wt.%, or between 0.6-7 wt.%, or between 0.8-6 wt.%, or between 2-4 wt.% of the electrode material. The conductive additive may be present in a total concentration of between 0.8- 4 wt.% of the electrode material; and the binder may be present in a total concentration of between 0.2-10 wt.%, or between 0.6-7 wt.%, or between 0.8-6 wt.%, or between 2-4 wt.% of the electrode material.

[0060] In some embodiments, the active material is present in a total concentration of between 50-99 wt.% of the electrode material; and the conductive additive is present in a total concentration of between 0.2-10 wt.% of the electrode material, or between 0.4-7 wt.%, or between 0.6-5 wt.%, or between 0.8-4 wt.% of the electrode material. The active material may be present in a total concentration of between 80-99 wt.% of the electrode material; and the conductive additive may be present in a total concentration of between 0.2-10 wt.% of the electrode material, or between 0.4-7 wt.%, or between 0.6-5 wt.%, or between 0.8-4 wt.% of the electrode material. The active material may be present in a total concentration of between 90-99 wt.% of the electrode material; and the conductive additive may be present in a total concentration of between 0.2-10 wt.% of the electrode material, or between 0.4-7 wt.%, or between 0.6-5 wt.%, or between 0.8-4 wt.% of the electrode material. The active material may be present in a total concentration of between 93-96 wt.% of the electrode material; and the conductive additive may be present in a total concentration of between 0.2-10 wt.% of the electrode material, or between 0.4-7 wt.%, or between 0.6-5 wt.%, or between 0.8-4 wt.% of the electrode material.

[0061] In some embodiments, the active material is present in a total amount of between 50-99 wt.% of the electrode material; the binder is present in a total amount of between 0.2-10 wt.% of the electrode material; and the conductive additive is present in a total amount of between 0.2-10 wt.% of the electrode material.

[0062] In some embodiments, the active material is present in a total amount of between 80-99 wt.% of the electrode material; the binder is present in a total amount of between 0.6-7 wt.% of the electrode material; and the conductive additive is present in a total amount of between 0.4-7 wt.% of the electrode material.

[0063] In some embodiments, the active material is present in a total amount of between 93-96 wt.% of the electrode material; the binder is present in a total amount of between 2-4 wt.% of the electrode material; and the conductive additive is present in a total amount of between 0.8-4 wt.% of the electrode material.

[0064] In some embodiments, the electrode has a coating weight of at least 30 g / m2, or at least 40, 50, 60, or at least 70 g / m2. In some embodiments, the electrode has a coating weight of no greater than 300 g / m2, or no greater than 280, 260, 240, 220, 200, 180, or no greater than 160 g / m2. The electrode may have a coating weight of between 30-300 g / cm2, or between 50-220 g / m2, or between 60-160 g / m2. Adhering the electrode material to the frozen solid in step (b) preferably causes the electrode material to adhere to the frozen solid with a greater strength than the adhesion of the electrode material to the current collector.

[0065] In some preferred embodiments, step (b) comprises only adhering the electrode material to the frozen solid. The current collector may not be adhered to the frozen solid.

[0066] In other embodiments, step (b) comprises adhering the electrode material and the current collector to the frozen solid. Step (b) may comprise adhering the entire electrode to the frozen solid.

[0067] In embodiments in which the electrode comprises a layer of the electrode material adhered to a layer of the current collector, step (b) may comprise adhering the layer of the electrode material to the frozen solid. In embodiments in which the electrode comprises a layer of the electrode material adhered to a layer of the current collector, step (b) may comprise adhering at least 5% of the total outer surface area of the layer of electrode material to the frozen solid, or at least 10, 20, 30, 40, 50, 60, 70, 80, 90, or at least 95% of the total outer surface area of the layer of electrode material. Step (b) may comprise adhering substantially the entire outer surface area of the layer of electrode material to the frozen solid. In some embodiments, step (b) may comprise adhering no greater than 95% of the total outer surface area of the electrode material to the frozen solid, or no greater than 90, 80, 70, 60, or no greater than 50% of the total outer surface area of the electrode material.

[0068] In embodiments in which the electrode comprises two layers of electrode material held on either side of a layer of the current collector, step (b) may comprise adhering a single layer or both layers of the electrode material to the frozen solid. In some embodiments, the frozen solid may be independently selected from the group consisting of: ice (frozen water or a frozen aqueous solution), a frozen organic species, a frozen inorganic species, and combinations thereof.

[0069] In some embodiments, the frozen solid comprises a frozen electrolyte, which may be a frozen battery electrolyte. The electrolyte may comprise an aqueous electrolyte or a nonaqueous electrolyte. The electrolyte may comprise an organic electrolyte.

[0070] In a particularly preferred embodiment, the frozen solid is ice.

[0071] In some embodiments, step (b) comprises directly contacting the electrode material with the frozen solid to adhere the electrode material to the frozen solid. Step (b) may comprise contacting the electrode material with a frozen solid surface.

[0072] In embodiments in which the electrode comprises a layer of the electrode material adhered to a layer of the current collector, step (b) may comprise directly contacting the layer of electrode material with the frozen solid to adhere the electrode material to the frozen solid. The layer of electrode material may be directly contacted with a frozen solid surface, such as by placing the electrode material layer on the frozen solid surface. Step (b) may comprise directly contacting only the layer of electrode material with the frozen solid and not the layer of current collector.

[0073] In preferred embodiments, the electrode material is adhered to the frozen solid in step (b) by freezing a liquid.

[0074] In preferred embodiments, step (b) comprises first contacting the electrode material with a liquid, and then freezing the liquid to adhere the electrode material to the frozen solid. The electrode material may be porous. In such embodiments, contacting the electrode material with a liquid may cause the liquid to enter or seep into at least one pore of the porous electrode material, and preferably into an internal porous structure of the electrode material. In such embodiments, when the liquid in the pores is frozen, it may help to more strongly adhere the electrode material to the frozen solid, allowing for easier delamination.

[0075] In some embodiments, the liquid is independently selected from the group consisting of: water or an aqueous solution, an organic liquid, an inorganic liquid, and combinations thereof. In some embodiments, the liquid is a solvent.

[0076] At least one organic liquid may comprise an organic chemical species comprising a functional group independently selected from the group consisting of: a carbonyl group, an alcohol group, an ether group, and amine or amino group, a halide group, a thiol group, a sulfide group, a nitrile group, a phenyl group, and combinations thereof. In some embodiments, the organic liquid may comprise a hydrocarbon liquid.

[0077] In some embodiments, at least one organic liquid may comprise an organic chemical species comprising a carbonyl functional group that is independently selected from the group consisting of: an amide, an aldehyde, a ketone, a carboxylic acid, and combinations thereof. In some embodiments, at least one organic chemical species is a lactam. The lactam may be a 5 -membered lactam. The lactam may comprise a pyrrolidone or derivative thereof. The lactam may comprise A-methyl-2-pyrrolidone (NMP).

[0078] In some embodiments, the liquid comprises an electrolyte, which may be a liquid battery electrolyte. The electrolyte may comprise an aqueous liquid electrolyte or a non-aqueous liquid electrolyte. The electrolyte may comprise an organic liquid electrolyte. In particularly preferred embodiments, the liquid comprises water. The liquid is preferably water or an aqueous solution. The water may be deionised water.

[0079] The step of contacting the electrode material with a liquid in step (b) may comprise submerging the electrode material in the liquid. The liquid may be frozen whilst the electrode material is submerged in the liquid.

[0080] Step (b) may comprise submerging at least 5% of the total outer surface area of the electrode material in the liquid, or at least 10, 20, 30, 40, 50, 60, 70, 80, 90, or at least 95% of the total outer surface area of the electrode material. Step (b) may comprise submerging substantially the entire outer surface area of the electrode material in the liquid. In some embodiments, step (b) may comprise submerging no greater than 95% of the total outer surface area of the electrode material in the liquid, or no greater than 90, 80, 70, 60, or no greater than 50% of the total outer surface area of the electrode material.

[0081] In some embodiments, step (b) may comprise submerging the electrode material and the current collector in the liquid. In such embodiments, step (b) may comprise submerging the entire electrode in the liquid.

[0082] In some preferred embodiments, step (b) comprises submerging only the electrode material in the liquid, and the current collector may not be submerged in the liquid.

[0083] In embodiments in which the electrode comprises a layer of the electrode material adhered to a layer of the current collector, step (b) may comprise submerging the layer of electrode material in the liquid. Step (b) may comprise submerging only the layer of electrode material in the liquid and not the layer of current collector.

[0084] In some embodiments, step (b) comprises submerging the electrode material in the liquid in a container. The container may comprise a base and a side wall. The base of the container may comprise at least one support structure extending upwards from the base of the container. The support structure may prevent the electrode from sinking to the bottom of the container when the electrode material is submerged. The base of the container may comprise a plurality of support structures extending upwards from the base of the container. In some embodiments, the support structure may comprise at least one protrusion, and preferably a plurality of protrusions. The protrusion may comprise a spike.

[0085] In some embodiments, step (b) comprises applying a liquid to a support, contacting the electrode material with the liquid on the support, and then freezing the water whilst the electrode material is in contact with the water on the support.

[0086] In embodiments in which the electrode comprises a layer of the electrode material adhered to a layer of the current collector, step (b) may comprise applying the liquid to the support, contacting the layer of electrode material with the liquid on the support, and then freezing the liquid whilst the layer of electrode material is in contact with the liquid on the support.

[0087] In some embodiments, the step of contacting the electrode material with the liquid on the support comprises placing the electrode material on the wet support, and then optionally pressing the electrode material on the support. In some embodiments, the electrode material may be pressed on the wet support for at least 2 seconds, or at least 3, 4, 5, 6, 7, 8, 9, or at least 10 seconds. In some embodiments, the electrode material may be pressed on the wet support for no greater than 60 seconds, or no greater than 50, 40, 30, or no greater than 20 seconds. In some preferred embodiments, the electrode material may be pressed on the wet support for between 2-60 seconds, or between 3-50 seconds, or between 4-40 seconds, or between 5-30 seconds, or between 5-20 seconds, or preferably between 7-20 seconds.

[0088] The electrode material may be pressed on the wet support with a force of at least 2 N, or at least 5 N. The electrode material may be pressed on the wet support with a force of between 1-15 N, or between 2-10 N, or between 2-7 N, or between 2-5 N.

[0089] The support may be at a temperature of no greater than 0 °C when the electrode material is contacted with the support. In some embodiments, the support is at a temperature of between 0 to -20 °C, or between 0 to -15 °C, or between 0 to -10 °C, or between 0 to -8 °C. In other embodiments, the support may be at a temperature of no greater than -5 °C, or no greater than -10, -15, -20, -25, -30, -35, -40, -45, -50, -55, -60, -65, -70, -75, -80, - 85, -90, -95, or no greater than -100 °C. In some preferred embodiments, the support may be at a temperature of between -2 to -15 °C, or between -3 to -12 °C, or between -4 to -10 °C, preferably between -5 to -10 °C. The liquid on the support may freeze when contacted with the electrode material, and no further freezing step may be performed. The pressing step may be the freezing step. The liquid on the support may freeze during the pressing step.

[0090] In some embodiments, the electrode material may be pressed on the wet support for between 5-30 seconds, or between 5-20 seconds, or preferably between 7-20 seconds; and the support may be at a temperature of between -2 to -15 °C. In some embodiments, the electrode material may be pressed on the wet support for between 5-30 seconds, or between 5-20 seconds, or preferably between 7-20 seconds; and the support may be at a temperature of between -3 to -12 °C. In some embodiments, the electrode material may be pressed on the wet support for between 5-30 seconds, or between 5-20 seconds, or preferably between 7-20 seconds; and the support may be at a temperature of between -4 to -10 °C. The electrode material may be pressed on the wet support for between 5-30 seconds, or between 5-20 seconds, or preferably between 7-20 seconds; and the support may be at a temperature of between -5 to -10 °C.

[0091] In some embodiments, the support is a metal support. The support may be a plate. The support may be a metal plate. The support may comprise a surface of a table, which may be a cold table.

[0092] In some embodiments, the step of contacting the electrode material with the liquid comprises applying the liquid to the electrode material. The step of contacting the electrode material with the liquid may comprise coating the electrode material with the liquid. The step of contacting the electrode material with the liquid may comprise coating the electrode material with droplets of the liquid.

[0093] The step of contacting the electrode material with the liquid in step (b) may comprise spray-coating the electrode material with the liquid.

[0094] Step (b) may comprise applying the liquid to or coating with the liquid at least 5% of the total outer surface area of the electrode material, or at least 10, 20, 30, 40, 50, 60, 70, 80, 90, or at least 95% of the total outer surface area of the electrode material. Step (b) may comprise applying the liquid to coating with the liquid substantially the entire outer surface area of the electrode material. In some embodiments, step (b) may comprise applying the liquid to or coating with the liquid no greater than 95% of the total outer surface area of the electrode material, or no greater than 90, 80, 70, 60, or no greater than

[0095] 50% of the total outer surface area of the electrode material. In some embodiments, step (b) may comprise applying the liquid to or coating with the liquid the electrode material and the current collector. In such embodiments, step (b) may comprise applying the liquid to or coating with the liquid the entire electrode.

[0096] In some preferred embodiments, step (b) comprises applying the liquid to or coating with the liquid only the electrode material, and the current collector may not be contacted with the liquid.

[0097] In embodiments in which the electrode comprises a layer of the electrode material adhered to a layer of the current collector, step (b) may comprise applying the liquid to or coating with the liquid the layer of electrode material. Step (b) may comprise applying the liquid to or coating with the liquid only the layer of electrode material and not the layer of current collector.

[0098] In some embodiments, step (b) comprises applying the liquid to at least a portion of the electrode material or coating at least a portion of the electrode material with the liquid, contacting said portion of the electrode material comprising the liquid with a support, and then freezing the liquid whilst the electrode material comprising the liquid is in contact with the support. In such embodiments, step (b) may comprise applying the liquid to the entire outer surface area of the electrode material or coating the entire outer surface area of the electrode material with the liquid.

[0099] In embodiments in which the electrode comprises a layer of the electrode material adhered to a layer of the current collector, step (b) may comprise applying the liquid to or coating with the liquid the layer of electrode material, contacting the layer of electrode material with a support, and then freezing the liquid whilst the layer of electrode material comprising the liquid is in contact with the support. In some embodiments, the step of contacting the electrode material with the support comprises placing the electrode material on the support, and then optionally pressing the electrode material on the support. In some embodiments, the electrode material may be pressed on the support for at least 2 seconds, or at least 3, 4, 5, 6, 7, 8, 9, or at least 10 seconds. In some embodiments, the electrode material may be pressed on the support for no greater than 60 seconds, or no greater than 50, 40, 30, or no greater than 20 seconds. In some preferred embodiments, the electrode material may be pressed on the support for between 2-60 seconds, or between 3-50 seconds, or between 4-40 seconds, or between 5- 30 seconds, or between 5-20 seconds, or preferably between 7-20 seconds.

[0100] The electrode material may be pressed on the support with a force of at least 2 N, or at least 5 N. The electrode material may be pressed on the support with a force of between 1-15 N, or between 2-10 N, or between 2-7 N, or between 2-5 N.

[0101] The support may be at a temperature of no greater than 0 °C when the electrode material is contacted with the support. In some embodiments, the support is at a temperature of between 0 to -20 °C, or between 0 to -15 °C, or between 0 to -10 °C, or between 0 to -8 °C. In other embodiments, the support may be at a temperature of no greater than -5 °C, or no greater than -10, -15, -20, -25, -30, -35, -40, -45, -50, -55, -60, -65, -70, -75, -80, - 85, -90, -95, or no greater than -100 °C. In some preferred embodiments, the support may be at a temperature of between -2 to -15 °C, or between -3 to -12 °C, or between -4 to -10 °C, preferably between -5 to -10 °C. The liquid on the electrode material may freeze when contacted with the support, and no further freezing step may be performed. The pressing step may be the freezing step. The liquid on the electrode material may freeze during the pressing step. In some embodiments, the electrode material may be pressed on the support for between 5-30 seconds, or between 5-20 seconds, or preferably between 7-20 seconds; and the support may be at a temperature of between -2 to -15 °C. In some embodiments, the electrode material may be pressed on the support for between 5-30 seconds, or between 5-20 seconds, or preferably between 7-20 seconds; and the support may be at a temperature of between -3 to -12 °C. In some embodiments, the electrode material may be pressed on the support for between 5-30 seconds, or between 5-20 seconds, or preferably between 7-20 seconds; and the support may be at a temperature of between -4 to -10 °C. The electrode material may be pressed on the support for between 5-30 seconds, or between 5-20 seconds, or preferably between 7-20 seconds; and the support may be at a temperature of between -5 to -10 °C.

[0102] In some embodiments, the step of contacting the electrode material with the support may be performed no greater than 30 seconds after the step of contacting the electrode material with the liquid, or no greater than 20 seconds, 15, 10, or no greater than 5 seconds after the step of contacting the electrode material with the liquid.

[0103] In some embodiments, the support is a metal support. The support may be a plate. The support may be a metal plate. The support may comprise a surface of a table, which may be a cold table.

[0104] The step of freezing the liquid in step (b) may comprise subjecting the electrode material in contact with the liquid to a temperature of no greater than 0 °C, or no greater than - 1 , - 2, -3, -4, or preferably to a temperature of no greater than -5 °C, or no greater than - 10, - 15, -20, -25, -30, -35, -40, -45, -50, -55, -60, -70, -75, -80, -85, -90, -95, or no greater than -100 °C. The step of freezing the liquid in step (b) may comprise subjecting the electrode material in contact with the liquid to a temperature of no less than -200 °C, or no less than -190, -180, -170, -160, -150, -140, -130, -120, -110, -100, -90, -80, -70, -60, or no less than -50 °C.

[0105] The step of freezing the liquid in step (b) may comprise subjecting the electrode material in contact with the liquid to a temperature of between 0 to -100 °C, or between 0 to -90 °C, or between 0 to -80 °C, or between 0 to -70 °C, or between 0 to -60 °C, or between 0 to -50 °C, or between -5 to -50 °C, or between -8 to -45 °C. In some preferred embodiments, the step of freezing the liquid in step (b) may comprise subjecting the electrode material in contact with the liquid to a temperature of between -2 to -15 °C, or between -3 to -12 °C, or between -4 to -10 °C, preferably between -5 to -10 °C. In such embodiments, the liquid may be or comprise water.

[0106] In other embodiments, the step of freezing the liquid in step (b) may comprise subjecting the electrode material in contact with the liquid to a temperature of between 0 to -200 °C, or between -10 to -200 °C, or between -20 to -200 °C, or between -30 to -200 °C.

[0107] In embodiments in which the electrode material is submerged in the liquid in step (b), the step of freezing the liquid in step (b) may comprise subjecting the electrode material submerged in the liquid to a temperature of between - 10 to - 100 °C, or between -20 to - 80 °C, or between -30 to -70 °C. In such embodiments, the liquid may be or comprise water.

[0108] In embodiments in which step (b) comprises applying the liquid to the electrode material or coating the electrode material with the liquid, the step of freezing the liquid in step (b) may comprise subjecting the electrode material comprising the liquid to a temperature of between 0 to -20 °C, or between 0 to -15 °C, or between 0 to -10 °C, or between 0 to -8 °C. In some preferred embodiments, the step of freezing the liquid in step (b) may comprise subjecting the electrode material comprising the liquid to a temperature of between -2 to -15 °C, or between -3 to -12 °C, or between -4 to -10 °C, preferably between -5 to -10 °C. In such embodiments, the liquid may be or comprise water.

[0109] The step of freezing the liquid in step (b) may comprise subjecting the electrode material in contact with the liquid to a temperature of no greater than 0 °C for at least 0.1 seconds, or at least 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or at least 1 second, or at least 2, 3, 4, 5, 6, 7, 8, 9, or at least 10 seconds, or at least 20 seconds, or at least 30 seconds, or at least 40 seconds, or at least 50 seconds, or at least 1 minute, or at least 2, 3, 4, or at least 5 minutes, or at least 10, 20, 30, 40, or at least 50 minutes, or at least 1 hour, or at least 1.5, 2, 2.5, or at least 3 hours. The step of freezing the liquid in step (b) may comprise subjecting the electrode material in contact with the liquid to a temperature of no greater than 0 °C for no longer than 1 day, or no longer than 20 hours, or no longer than 15, 10, or no longer than 5 hours. The step of freezing the liquid in step (b) may comprise subjecting the electrode material in contact with the liquid to a temperature of no greater than 0 °C for between 5 second to 5 hours, or between 10 seconds to 5 hours, or between 1 minute to 5 hours, or between 3 minutes to 4 hours, or between 5 minutes to 3 hours.

[0110] In other embodiments, the step of freezing the liquid in step (b) may comprise subjecting the electrode material in contact with the liquid to a temperature of no greater than 0 °C for no longer than 5 seconds, or no longer than 4, 3, 2, or no longer than 1 second, or no longer than 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, or no longer than 0.1 seconds. In some embodiments, the step of freezing the liquid in step (b) may comprise subjecting the electrode material in contact with the liquid to a temperature of no greater than 0 °C for between 0.1-5 seconds, or between 0.1 -2 seconds, or between 0.1-1 seconds. Such times may be especially suited to continuous processes, such as reel-to-reel processes wherein the electrode material may be subjected to these temperatures as it is passed against a cold roller.

[0111] In embodiments in which the electrode material is submerged in the liquid in step (b), the step of freezing the liquid in step (b) may comprise subjecting the electrode material submerged in the liquid to a temperature of no greater than 0 °C for between 30 minutes to 5 hours, or between 30 minutes to 3 hours, or between 1 hour to 3 hours.

[0112] In embodiments in which step (b) comprises applying the liquid to the electrode material or coating the electrode material with the liquid, the step of freezing the liquid in step (b) may comprise subjecting the electrode material comprising the liquid to a temperature of no greater than 0 °C for between 5 seconds to 30 minutes, or between 10 seconds to 30 minutes, or between 10 seconds to 25 minutes, or between 10 seconds to 20 minutes, or between 10 seconds to 15 minutes, or between 10 seconds to 10 minutes.

[0113] In some embodiments, the step of freezing the liquid in step (b) is performed in a freezer.

[0114] In some embodiments, the step of freezing the liquid in step (b) is performed using an ice-cream maker.

[0115] In some embodiments, the electrode material of the electrode provided in step (a) is already in contact with a liquid, and step (b) comprises freezing the liquid to adhere the electrode material to a frozen solid. In such embodiments, no additional step of contacting the electrode material with a liquid is required.

[0116] In such embodiments, the freezing step may be performed as described in statements of invention above. In such embodiments, the liquid may be as described in statements of invention above.

[0117] In some preferred embodiments, the liquid may be an electrolyte, preferably as described in statements of invention above. In such embodiments, the electrode may be isolated from a battery in step (a) and the electrode material of the electrode may already be in contact with a liquid electrolyte, which is subsequently frozen in step (b) to adhere the electrode material to the frozen solid electrolyte.

[0118] In preferred embodiments, the current collector is physically delaminated from the electrode material in step (c). Adhering the electrode material to the frozen solid in step (b) preferably causes the electrode material to adhere to the frozen solid with a greater strength than the adhesion of the electrode material to the current collector such that the current collector can be physically delaminated from the electrode material.

[0119] In some embodiments, the delamination step in step (c) comprises peeling the current collector away from the electrode material whilst the electrode material is adhered to the frozen solid. In some embodiments, the delamination step in step (c) comprises peeling the electrode material away from the current collector whilst the electrode material is in contact with the frozen solid.

[0120] In embodiments in which the electrode comprises a layer of the electrode material adhered to a layer of the current collector, step (c) may comprise peeling the layer of the current collector away from the layer of electrode material whilst the layer of electrode material is adhered to the frozen solid.

[0121] In embodiments in which the electrode comprises two layers of electrode material held on either side of a layer of the current collector, only one of the layers of electrode material may be adhered to the frozen solid, and step (c) may comprise delaminating the other layer of electrode material and current collector from the electrode material that is adhered to the frozen solid. The other layer of electrode material and current collector may be adhered to each other when delaminated from the layer of electrode material that is adhered to the frozen solid. After the first delamination step, the other layer of electrode material may be adhered to the frozen solid and the current collector delaminated from the other layer of electrode material when the other layer is adhered to the frozen solid.

[0122] In other embodiments in which the electrode comprises two layers of electrode material held on either side of a layer of the current collector, both layers of electrode material may be adhered to the frozen solid, and step (c) may comprise delaminating the current collector from both layers of electrode material simultaneously when the layers of electrode material are adhered to the frozen solid.

[0123] In some embodiments, the delamination step in step (c) comprises delaminating the current collector from the electrode material using a roller. Such a delamination method may be especially useful for embodiments in which the method of the invention is a continuous process.

[0124] The roller, and preferably a surface thereof may be held at a temperature of no greater than 0 °C. The roller, and preferably the surface thereof may be held at a temperature as described in statements of inventions above for freezing a liquid that is in contact with the electrode material. In such embodiments, an electrode comprising an electrode material that is in contact with a liquid may be contacted with the roller. Preferably, the electrode material is contacted with the roller. Contacting with the roller may comprise feeding a reel comprising the electrode past the roller. In such embodiments, the liquid in contact with the electrode material of the electrode may freeze on contact with the roller causing the electrode material to be adhered to a frozen solid that is also adhered to the roller. In such embodiments, the roller may delaminate the current collector from the electrode material as the electrode contacts the roller.

[0125] In some embodiments, the delamination step in step (c) comprises delaminating the current collector from the electrode material using two rollers. The two rollers may be adjacent to each other but not in contact with each other. The two rollers that are adjacent to each other may define a gap between them. Both rollers may be held at a temperature no greater than 0 °C, preferably as described above, a two-roller setup may function in an analogous manner to the single roller setup described above. In such embodiments, the electrode comprising an electrode material that is in contact with a liquid may be fed through the gap between the two rollers causing the liquid to freeze as the electrode is fed through the gap and as the electrode material contacts at least one roller, and the electrode material may be delaminated from the current collector as described for the single roller setup above.

[0126] A two-roller setup may be particularly useful in embodiments wherein the electrode comprises two layers of electrode material held on either side of a layer of the current collector. In such embodiments, both layers of electrode material may be in contact with a liquid and feeding the electrode through the gap between the two rollers may cause both electrode material layers to contact a roller, which may cause the liquid in contact with both layers of electrode material to freeze and cause the layers of the electrode material to be adhered to the resulting frozen solid. Feeding the electrode through the gap between the rollers may therefore delaminate the current collector from both layers of electrode material simultaneously, using an analogous method to that described for the single roller setup above.

[0127] In some embodiments, the delamination step may comprise passing the electrode through a plurality of rollers, which may comprise greater than 2 rollers. The method may be performed as described for a single roller setup or two-roller setup above. The rollers may be arranged in any suitable arrangement.

[0128] In some embodiments, step (d) comprises the step of separating the free electrode material from frozen solid that is still in contact with the free electrode material.

[0129] In some embodiments, step (d) comprises the step of melting frozen solid that is still in contact with the free electrode material to separate the free electrode material from the frozen solid.

[0130] In some embodiments, the step of melting the frozen solid that is still in contact with the free electrode material in step (d) comprises heating the free electrode material. The step of melting the frozen solid may comprise subjecting the free electrode material to a temperature of above 0 °C, or to a temperature of at least 5 °C, or at least 10, 15, or to a temperature of at least 20 °C.

[0131] In some embodiments, the electrode material comprises at least one binder and the method further comprises the step of separating at least one binder from the free electrode material. The step of separating at least one binder from the free electrode material may be performed after step (d).

[0132] At least one binder may comprise a water-soluble and / or non-water-soluble binder, preferably as described in statements of invention above. The step of separating at least one binder from the free electrode material may comprise washing the free electrode material with water. The water may comprise deionised water.

[0133] In some embodiments, the method comprises a further step of drying the free electrode material. The drying step may be performed after step (d). The drying step may be performed after the step of separating at least one binder from the free electrode material.

[0134] In some embodiments, the drying step comprises heating the free electrode material. In some embodiments, the drying step comprises heating the free electrode material to a temperature of at least 30 °C, or at least 40, 50, 60, 70, 80, 90, or to a temperature of at least 100 °C. The drying step may comprise heating the free electrode material to a temperature of no greater than 300 °C, or no greater than 250, 200, or no greater than 150 °C. The drying step may comprise heating the free electrode material to a temperature of between 30-300 °C, or between 40-250, 50-200, or between 100-150 °C.

[0135] In some embodiments, the drying step comprises heating the free electrode material for a total time of at least 10 minutes, or at least 20, 30, 40, or at least 50 minutes, or at least 1 hour, or at least 2, 3, 4, 5, 10, or at least 15 hours. The drying step may comprise heating the free electrode material for a total time of no greater than 1 day, or no greater than 22 hours, or no greater than 20, or no greater than 18 hours. The drying step may comprise heating the free electrode material for a total time of between 1 hour to 1 day, or between 5 hours to 1 day, or between 10 hours to 1 day.

[0136] In some embodiments, the method of the invention may be performed as a batch process.

[0137] In some embodiments, the method of the invention may be performed as a continuous process. In such embodiments, the method may comprise a reel-to-reel process. A continuous process may be particularly useful in embodiments in which the electrode comprises a scrap or waste electrode.

[0138] According to a second aspect of the invention, there is provided a method of separating a battery electrode material from a battery, the method comprising the steps of:

[0139] (a) Providing a battery;

[0140] (b) Isolating an electrode from the battery, the electrode comprising an electrode material adhered to a current collector;

[0141] (c) Adhering the electrode material to a frozen solid;

[0142] (d) Delaminating the current collector from the electrode material when the electrode material is adhered to the frozen solid to provide a free electrode material and a free current collector; and

[0143] (e) Recovering the free electrode material.

[0144] Steps (b) to (e) of the second aspect of the invention may be steps (a) to (d) of the first aspect of the invention.

[0145] The battery of the second aspect of the invention may preferably be as described for the first aspect of the invention.

[0146] Statements of invention above relating to the first aspect of the invention may also be applied mutatis mutandis to the second aspect of the invention.

[0147] According to a third aspect of the invention, there is provided a method of recycling a battery, the method comprising steps (a) to (d) of the method of the second aspect of the invention, and further comprising the step of:

[0148] (e) Recovering and reusing the free electrode material and / or free current collector. Statements of invention above relating to the first aspect of the invention may also be applied mutatis mutandis to the third aspect of the invention.

[0149] Statements of invention below for the third aspect of the invention may also be applied mutatis mutandis to the other aspects of the invention.

[0150] In some embodiments, step (e) comprises the step of reusing the recovered free electrode material and / or free current collector in the manufacture of an electrode. The electrode may preferably be as described in statements of invention for the first aspect of the invention above.

[0151] In some embodiments, reuse of the free electrode material in the manufacture of an electrode comprises adhering the free electrode material to a current collector. The current collector may be the free current collector from the delaminated electrode or may be a further separate current collector.

[0152] In some embodiments, reuse of the free current collector in the manufacture of an electrode comprises adhering the current collector to an electrode material. The electrode material may be the free electrode material from the delaminated electrode or may be a further separate electrode material.

[0153] The free electrode material and / or free current collector may be used in the manufacture of an electrode using a method independently selected from the group consisting of: a slurry cast process, slurry coating, doctor blade coating, roll-to-roll coating, electrodeposition, sputter deposition, screen printing, spray coating, laser ablation, a solgel process, calendaring, and combinations thereof. In some preferred embodiments, the free electrode material and / or free current collector are used in the manufacture of an electrode using a slurry cast process. In some embodiments, the manufactured electrode is subjected to a drying step after its formation. The drying step may comprise heating the electrode. The electrode may be heated to a temperature of at least 40 °C, or at least 50, or at least 60, 70, 80, 90, or at least 100 °C. The drying step may be performed for at least 1 hour, or at least 2, 3, 4, 5, 10, 15, or at least 20 hours. The drying step may be performed for at least one day.

[0154] The drying step may be performed under low pressure. The drying step may comprise heating the electrode under low pressure.

[0155] In some embodiments, the manufactured electrode is used in the manufacture of a battery. The battery may preferably be as described in statements of invention for the first aspect of the invention above.

[0156] In some embodiments, the electrode material comprises at least one binder and the method further comprises the step of separating at least one binder from the free electrode material. The step of separating at least one binder from the electrode material may be performed before reusing the electrode material to provide a binder-free free electrode material for subsequent reuse. Statements of invention for the first aspect of the invention above relating to the binder removal step may also be applied here.

[0157] In some embodiments, the binder-free free electrode material may be combined with a further binder after the binder removal step and before reuse of the free electrode material, preferably in the manufacture of an electrode.

[0158] In some embodiments, the method may comprise the step of adding at least one further conductive additive to the free electrode material before reuse. At least one further conductive additive may preferably be as described in statements of invention for the first aspect of the invention above. In some embodiments, the method may comprise the step of reintercalating to the free electrode material before reuse.

[0159] Detailed Description of the Invention

[0160] In order that the invention may be more clearly understood, embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

[0161] Figure 1 shows a 3D-printed tray used for the delamination method of the invention via submersion in water.

[0162] Figure 2 illustrates how a current collector is delaminated from an electrode material when the electrode material is in contact with ice in the delamination method of the invention.

[0163] Figure 3 displays a flow-chart illustrating the stages of the delamination method of the invention via contact of the electrode material with a wet support.

[0164] Figure 4 displays a flow-chart illustrating a 2-stage delamination process of a trilayer electrode using a delamination method of the invention via contact of the electrode material with a wet support.

[0165] Figure 5 shows x-ray diffraction patterns of reclaimed (a) Prussian white and (b) hard carbon electrode material powders after the delamination method of the invention, compared with pristine (a) Prussian white and (b) hard carbon samples.

[0166] Figure 6 shows scanning electron microscopy images of (a) pristine Prussian white, (b) Prussian white cathode electrode material before delamination, (c) reclaimed Prussian white electrode material obtained after a ballmilling delamination technique (prior art method), and (d) reclaimed Prussian white electrode material after the delamination method of the invention.

[0167] Figure 7 shows scanning electron microscopy images of (a) and (b) different areas on a hard carbon electrode material of an electrode after disassembly from a battery and drying at 120 °C, and (c) reclaimed hard carbon electrode material after the delamination method of the invention.

[0168] Figure 8 shows scanning electron microscopy images of (a) an Al current collector obtained after a ball-milling delamination method (prior art method) to separate the Al current collector from a Prussian white electrode material, (b) Prussian white electrode material which remained adhered to an Al current collector after the ball-milling delamination method (prior art method), (c) a reclaimed Al current collector obtained after a delamination method of the invention via submersion in water performed at -10 °C for 3h to separate the Al current collector from a Prussian white electrode material, and (d) a reclaimed Al current collector obtained after a delamination method of the invention via submersion in water performed at -40 °C for Ih to separate the Al current collector from a Prussian white electrode material.

[0169] Figure 9 Coating Separation Efficiency (CSE) values for electrode materials that were delaminated from electrodes using different delamination techniques. First bar: ball milling delamination technique (prior art method); second bar: ice- stripping delamination technique of the invention (via submersion in water); modified ice-stripping delamination technique of the invention (via contact with a wet support / via spray coating).

[0170] Figure 10 shows results of cell testing at 10 mA / g with IM NaPFr, in EC (ethylene carbonate): DEC (diethyl carbonate) (1:1 v / v). (a) Initial voltage profile of pristine Prussian white (PW) and reclaimed Prussian white (re-PW) electrode material (after delamination using a delamination method of the invention) half-cells, (b), (c) Initial discharge profile and the cycling stability of reclaimed hard carbon (re-HC) electrode material (after delamination using a delamination method of the invention) half-cell, (d), (e) Initial full cell voltage profile and cycling comparison between PW|re- HC and PW|pristine HC. (f) 3-electrode HC half-cell voltage profile differences when controlling Eceii and Ewe.

[0171] Figure 11 shows surface morphologies of: (a) an end-of-life (EoL) graphite electrode; (b) a reclaimed Cu current collector; (c) delaminated reclaimed graphite flakes; and (d) reclaimed graphite powder, from the Nissan Leaf Gen2 EoL Li-ion cell - graphite anode delamination to material reclamation case study described below.

[0172] Figure 12 is a schematic representation of the ice-stripping delamination process and the direct manufacturing towards a new anode with reclaimed graphite from the Nissan Leaf Gen2 EoL Li-ion cell - graphite anode delamination to material reclamation case study described below. Figure 13 shows the results of cell testing performed for the Nissan Leaf Gen2 EoL Li-ion cell - graphite anode delamination to material reclamation case study described below. Cell testing was performed at 10 mA / g with 1 M NaPFr, in EC: DEC (1:1 v / v). (a) Initial voltage profile of pristine graphite and reclaimed graphite half-cell. Inserted SEM image shows the reclaimed graphite powder, (b) Cycling stability of reclaimed graphite anode.

[0173] Figure 14 is a schematic representation of the ice-stripping delamination process performed on the manufacturing scraps and the direct manufacturing towards a new electrodes with reclaimed powders from the Battery manufacturing scraps - graphite anode delamination to material reclamation case study described below.

[0174] Figure 15 shows surface morphologies of: (a) reclaimed Al current collectors; and (b) reclaimed cathode powders, from the Battery manufacturing scraps - graphite anode delamination to material reclamation case study described below.

[0175] Figure 16 shows surface morphologies of: (a) reclaimed Cu current collectors; and (b) reclaimed anode powders, from the Battery manufacturing scraps - graphite anode delamination to material reclamation case study described below.

[0176] Figure 17 shows the results of cell testing performed for the Battery manufacturing scraps - graphite anode delamination to material reclamation case study described below. Cell testing was performed at 10 mA / g with 1 M NaPFr, in EC: DEC (1:1 v / v). Initial charge / discharge profiles of re-manufactured anode from reclaimed graphite powder as delaminated (Scrap-R-as delaminated), grounded and sieved with a 53 pm mesh (Scrap-R-ground), and without additional conductive carbons (Scrap-R-no C45) are shown. The insert shows preliminary cycling data.

[0177] Testing of delamination methods of the invention

[0178] The delamination method of the invention was tested using a sodium-ion battery containing electrodes, the negative electrode comprising a hard carbon (HC) electrode material and the positive electrode comprising a Prussian white (PW) electrode material, both of which contained CMC-SBR composite binders.

[0179] To demonstrate the versatility of the method, it was further demonstrated with a lithium- ion PVDF binder and nickel manganese cobalt oxide (NMC) cathode.

[0180] All electrodes contained electrode materials present as layers, and which were adhered to a layer of Al film current collector.

[0181] Delamination method of the invention by submersion in water

[0182] A tailored tray was designed and 3D-printed as shown in Figure 1. To minimize the amount of solvent, deionized (DI) water in this case, the height of the tray was set to 1 cm, which was sufficient for the electrode delamination. To begin the delamination process, at first the tray was filled with water, and the electrode was placed on top of it such that the electrode material was in contact with the water. The tray contained several spikes, which were slightly lower than the 1 cm and well distributed to prevent the electrode material from sinking. The tray with the electrode undergoing delamination was placed on a flat surface inside a refrigerator which was maintained at -40 °C for 1 h. It is believed that the water was able to penetrate the porous network present inside the electrode material, and with passage of time the temperature dropped down to sub-zero values freezing the water to ice. After 1 h, the tray was taken out from the refrigerator and the current collector was carefully peeled off from the electrode material, whilst the electrode material was in contact with the ice (as illustrated in Figure 2). The electrode material was separated from the Al current collector and remained in the iced tray.

[0183] Without wishing to be bound by theory, it is believed the delamination was made possible due to the adhesion of the electrode material to the ice (frozen solid) being significantly greater than that of the electrode material to the current collector. Adhesion measurements showed that the sodium-ion electrode materials have relatively poor adhesion, whereas the Li-ion cathode with PVDF is significantly greater. However, it is believed that because of the water penetration throughout the electrode material, the ice containing the electrode material remained behind after the current collector was stripped, as it was bonded to the ice in the tray.

[0184] Delamination method of the invention by contact with a wet support

[0185] The delamination method of the invention was further improved and modified using an ice-cream maker, as shown in Figure 3. This method is once again believed to make use of the strong adhesion of a frozen solid ( in this case ice) to the electrode material vs the relatively weaker adhesion of the electrode material to the current collector.

[0186] The improved method was similar to the submersion method above. However, deionised water was applied to a metal plate support of an ice-cream machine. The electrode was placed on the wet support with the electrode material facing against the wet support. The water was then frozen using the ice-cream machine. The temperature of the ice-cream machine was set to -8 °C and freezing time was set to 5 minutes. Because of lower quantities of water used compared to the submersion method, higher temperatures and a shorter freezing time could be used. Ice formed at the surface of the support and adhered to the electrode material of the electrode. The Al foil current collector was then peeled away from the electrode material whilst the electrode material was in contact with the ice.

[0187] This support-based method allowed for a reduced amount of water to be used compared to the submersion method, a reduced processing time (freezing time), easier handling, and this method can be more easily scaled up and industrialised.

[0188] Use of wet support based method on a trilayer electrode

[0189] The wet support method was also used to delaminate a trilayer electrode, which comprised an Al film current collector layer held between two layers of electrode material which were adhered to either side of the current collector layer.

[0190] The method was performed as described above to sequentially strip the current collector from both electrode material layers, as displayed in Figure 4.

[0191] Delamination method of the invention by spray coating

[0192] To further demonstrate the delamination method of the invention, a spray coat and freeze method was tested which allowed for further reduction in the volumes of liquid (in this case water) used and a further increase in the speed of the delamination method.

[0193] Water was sprayed onto the electrode material before it was placed onto a cold plate support of an ice-cream machine (set at -8 °C). The electrode material was pressed for 10 seconds onto the cold plate and then the current collector was immediately peeled away from the electrode material. This process allowed for even less water to be used and the freezing time was much lower and took place as the electrode material was pressed against the cold plate. Without wishing to be bound by theory, this method is believed to rely upon the thermal conductivities of the components of the electrode to transfer heat away from the electrode material quickly, such that freezing occurs.

[0194] Characterisation

[0195] X-ray diffraction and energy dispersive spectroscopy

[0196] After separate delamination of the PW electrode material cathode and HC electrode material anode using methods of the invention, the electrode materials were separately washed and centrifuged several times with deionised water to remove the binders and the final reclaimed PW (re-PW) and HC (re-HC) electrode material powders were dried at 120 °C overnight. The X-ray diffraction (XRD) pattern of reclaimed PW shows a different phase compared to the pristine PW as shown in Figure 5 a. The as-received PW NaxFe[Fe(CN)6] is the monoclinic phase with x >1.9, which means the Na / Fe ratio is > 0.95. The energy dispersive spectroscopy (EDS) results show the average value of Na / Fe ratio in the reclaimed PW power is -0.33, which indicates the Na loss from battery use and during / after the delamination process. Therefore, the reclaimed PW powder is the lower Na content cubic phase rather than the as received monoclinic phase as shown in Figure 5a. This is well known for Prussian blue analogies (PB As) as the presence of H2O affects the structure of PBAs. As water was used in the delamination process such a phase change is expected after PW reclamation. The HC reclamation is much simpler as the presence of water has less of an effect on the structure of HC as shown in Figure 5b. All the peaks in the XRD patterns of reclaimed HC can be indexed to the pristine HC.

[0197] Scanning electron microscopy

[0198] The physicochemical characterizations of both reclaimed PW and HC were carried out to study the ice-stripping delamination process of the invention. However, the electrochemical characterization for reclaimed PW (re-PW) is limited due to the structure change.

[0199] Figure 6a and 6b display, respectively, the morphology of the pristine PW powder and the PW electrode material from end-of-life cells before delamination. Figures 6c and 6d show, respectively, the morphologies of the reclaimed PW powder via ball-milling (not of the invention) and ice-stripping techniques (of the invention). The involvement of ballmilling in the delamination process breaks some big PW cubic particles into smaller pieces as well as smoothing the particle surface as shown in Figure 6c. The inventive icestripping technique, on the other hand, maintains the morphology and the particle size of PW as shown in Figure 6d, which is beneficial for any subsequent direct recycling processes (e.g. re-sodiation).

[0200] Different from the PW cathode electrode material, some unevenly distributed white stains were observed on the HC anode after disassembling from the battery and drying the anode at 120 °C, as shown in Figure 7a, which are likely from Na plating during cell operation as well as solid electrolyte interphase (SEI) components after exposing to air during disassembly and washing processes of the electrode. Figure 7b and 7c present the scanning electron microscopy (SEM) images of the HC anode electrode material after disassembly and the reclaimed HC powder electrode material after the ice- stripping method of the invention. Similar to what was found for the PW cathode; the reclaimed HC powder maintained both the particle size as well as the morphology of the HC electrode material before the ice-stripping method of the invention was performed.

[0201] The morphologies of the Al current collectors were also studied and compared between ball-milling (not of the invention) (Figure 8a, b) and ice-stripping (of the invention) delamination techniques (Figure 8c, d). Micro-wrinkles are observed on the Al surface, as shown in Figure 8a, after ball-milling which come from crush damage from zirconium ballas during the milling process. Some un-delaminated PW electrode material powders are also observed in some areas on the Al current collector as shown in Figure 8b. These observations indicate that insufficient delamination was achieved from the ball-milling procedure. The damaged Al also reduces the chances of the current collector being directly re-used or re-manufactured for subsequent new battery production.

[0202] In contrast to the ball-milling process, the Al current collector after the ice-stripping method of the invention remains flat without any wrinkles. Figure 8c and 8d display the respective morphologies of the Al surface after -10 °C ice-stripping and -40 °C icestripping, using the submersion method. Some grooves are seen, but less wrinkles are observed on the surface and as the delamination temperature lowers, the grooves become deeper. There is also a low amount of remaining PW electrode material powders detected on the Al, however the amount is much less than those from ball-milling (Figure 8a). The electrode material black mass residuals on the Al current collector after ice-stripping were easily removed by gently wiping the Al current collector with isopropyl alcohol or deionised water. With the ice-stripping methods of the invention performed using an ice-cream maker (contact with wet support and spray coating methods discussed above), the delamination time was further reduced compared to the submersion method, and the amount of deionised water used was also lowered. Moreover, the Al current collector surface after the ice-cream maker delamination methods of the invention was found to have no grooves in contrast to what was observed using the submersion method shown in Figure 8.

[0203] Compound Separation Efficiency

[0204] The study of the Al current collector also suggests that as a delamination technique, the ice-stripping method of the invention is more effective than classic ball-milling and offers more possibilities in current collector reuse.

[0205] The Compound Separation Efficiency (CSE) of the electrode material coating was calculated with the equation below.

[0206] CSEcoating = (mass of separated electrode material coating) / (initial mass of electrode material coating)

[0207] The Coating Separation Efficiency between ball-milling (not of the invention), freezer ice-stripping (submersion method of the invention) and ice-cream maker ice-stripping (contact with wet support and spray coating methods of the invention) are presented in Figure 9. Compared to the 53% separation efficiency of that given by ball-milling (not of the invention), the ice-stripping technique of the invention can achieve a separation efficiency as high as 96% using the ice creamer maker.

[0208] Use of reclaimed materials in the manufacture of batteries and cell testing The re-PW as well as the re-HC were directly reused after they were washed and dried at 120 °C as a cathode and anode and re-manufactured into a battery. The re-PW cathode electrode material coating contained 93 wt.% re-PW, 3 wt.% CMC / SBR binders and 3 wt.% C65 (carbon black conductive additive). The re-HC anode electrode material coating contained 96 wt.% re-HC, 3 wt.% CMC / SBR binders and 1 wt.% C45 (carbon black conductive additive). The mass loading was around 8.5 mg / cm2. Half-cells were first studied using IM NaPFe dissolved in EC (ethylene carbonate) :DEC (diethyl carbonate) (1: 1 V / V) as the electrolyte in the voltage window of 2.0-4.0 V vs. Na+ / Na. The galvanostatic charge-discharge profiles of re-PW were compared with pristine PW as presented in Figure 10a. The profile of pristine PW shows two-steps charging with plateaus at 3.1 V and 3.3 V where each plateau contributes almost an equal specific capacity. Similar two-step processes were also observed for the discharging step. In contrast to the pristine PW, the galvanostatic charge and discharge profiles of re-PW showed less distinctive and much shorter plateaus, indicating lower Na contents in the reclaimed materials which resulted from the phase changing during the reclamation process. This is consistent with the XRD results (Figure 5a). Thus, the re-PW would need to be re-sodiated to be able to re-manufactured into a material with comparable performance to the pristine material, Nevertheless, the good capacity achieved, despite the phase transition from the lower Na content, suggests that the process of the invention preserved the key backbone of the material, such that it could be reintroduced into the commercial manufacturing stream and resodiated.

[0209] The re-HC was also tested in a half cell in the voltage window of 0.01 V-3.00 V at a specific current of 10 mA / g as shown in Figure 10b. The HC half-cell discharge profile consists of two distinct phases, a sloping region at high voltage and a plateau at low voltage 0-0.1 V, corresponding to the absorption- intercalation mechanism. However, the plateau at low voltage in the half cell is highly affected by the metallic Na counter electrode. The overpotential caused by metallic Na results in the short / disappeared plateau as was observed in this case. Only about half of the capacity (152.8 mAh / g) can be achieved as observed in Figure 10b. The capacity then dropped to 42% of the initial capacity after 35 cycles (Figure 10c). To avoid the challenges associated with testing vs Na metal, the re-HC anode was also tested in a full cell configuration. A PW cathode, using CMC / SBR as the binder, was prepared to balance the re-HC anode. The 1st chargedischarge profile of the PW / re-HC and PW / pristine HC are shown in Figure lOd. The full cell assembled with re-HC gave similar profiles as the one with pristine HC, and the capacities are 121.8 and 128.6 mAh / g respectively. However, a much bigger deviation was observed in the PW / re-HC compared to PW / Pristine HC full cells as shown in Figure lOe. This is likely due to the presence of residual binders and SEI layers in the re-HC powders.

[0210] Further testing

[0211] In order to show that the ice-stripping delamination technique of the invention is binder agnostic, the method was also applied to delaminate PVDF-binder PW electrodes as well as PVDF-binder layered oxide electrodes. In both cases, the ice-stripping approach of the invention demonstrated successful high yield delamination, thus showing that the approach could be used in the Li ion battery field, with PVDF binder commonly used in the cathode.

[0212] The effect of temperature on the ice-stripping delamination method of the invention To determine the effect of temperature on the ice-stripping delamination method of the invention, ice- stripping was performed to recover a cathode electrode material from a current collector using the spray coating delamination method described above.

[0213] Different runs were performed and the temperature of the cold plate support was varied for each run.

[0214] The results are shown in Table 1 below.

[0215] Table 1

[0216] As seen from the results in Table 1, delamination first occurred at a cold plate support temperature of -4 °C. As the temperature was further decreased, the force required to delaminate the electrode material from the current collector decreased, reaching a minimum at -8 °C. However, as the temperature was further decreased to -10 °C, the force required for delamination increased.

[0217] The effect of contact time on the ice-stripping delamination method of the invention

[0218] To determine the effect of the contact time of the electrode material with the cold plate on the ice-stripping delamination method of the invention, an analogous method to the method used to investigate the effect of temperature was performed. The contact time was varied for the different runs.

[0219] The results are shown in Table 2 below.

[0220] The results in Table 2 above show that contact time also significantly influenced the material recovery. The results indicate that while the ice-stripping process could be carried out at a temperature of -4 °C and below, the contact time between the electrode material and the frozen surface is important for the effective recovery of the coated materials. A very short contact time of 5 seconds is unlikely to yield 100% material recovery at higher temperatures. Conversely, shorter contact times favour material recovery at lower temperatures, such as -10 °C. However, increasing the contact time at these lower temperatures can complicate material recovery, as it can cause the electrode to tear during the stripping process.

[0221] A pull test was conducted to investigate the effect of contact time at -10 °C. When the contact time was increased to 20 seconds, the rheometer could not pull the electrode free while reading a force of 50 N, indicating that it was stuck. This can be explained by the longer contact time allowing the penetrated water within the electrode material pores and on the current collector to freeze completely, making separation more difficult.

[0222] A study on the effect of applied force to press the electrode material onto the cold plate was performed using an analogous method to that used to investigate the effect of temperature and contact time above.

[0223] Four commercially available cells were tested.

[0224] The study showed that a minimum force of 2 N was enough for the ice-stripping method of the invention for certain electrode types. Overall, 5 N was effective for all four commercial cells tested in the study. force tests

[0225] In summary, the results of the above tests show that the ice-stripping temperature, applied force and contact time can be managed and tuned to optimise the efficiency of the material recovery process.

[0226] It is also important to ensure that the electrode material’ s surface remains wet by the time it makes contact with the cold plate surface. When an electrode material is sprayed or wetted, the surface can dry off quickly (depending on its wettability) before getting to the cold surface. If there are large delays, this can hinder the effectiveness of the icestripping method.

[0227] Case study: Nissan Leaf Gen2 end-of-life (EoL) Li-ion cell - Graphite anode delamination to material reclamation The ice-stripping delamination method of the invention was evaluated for a Nissan Gen2 battery module.

[0228] After discharging and dismantling of the battery module, the electrodes were ready for delamination. Delamination of the graphite anode was performed using the ice-stripping method of the invention. After delamination, the black masses were collected and dried at 120 °C overnight.

[0229] The delaminated graphite flakes preserved their morphology after separation compared to the EoL electrodes (see Figure Ila and Figure 11c). The reclaimed Cu current collector of the electrode showed some features, including craters, wrinkles or calendaring traces on the surface as shown in Figure 11b.

[0230] To remanufacture the reclaimed graphite, the delaminated flakes were grounded to get reclaimed graphite powder (re-Graphite, Figure l id) and assessed for direct recycling possibilities without any further treatments. A schematic representation of the icestripping delamination process and the direct manufacturing towards a new anode with reclaimed graphite is provided in Figure 12.

[0231] The re-manufactured re-Graphite negative electrode contained (90wt% re-Graphite, 2wt% CMC, 3wt% SBR binders and 5wt% C45) and this was evaluated in a lithium-ion battery half-cell. The pristine and recovered Graphite voltage profiles are compared in Figure 13a. The first discharge curve of re-Graphite shows a tiny plateau around 0.75 V corresponding to the SEI formation and side reactions originating from the oxidized surface. By delivering a specific capacity of 345.1 mAh / g (re-Graphite) compared to 354.9 mAh / g (Pristine), the initial coulombic efficiency (ICE) of re-Graphite possesses

[0232] 85.1% compared to 90.0% of Pristine Graphite as presented in Figure 13a. After 5 cycles of formation at 10 mA / g, the re-graphite half-cells were cycled at 0.5 C and retained good stability over 50 cycles as shown in Figure 13b.

[0233] Case study: Battery manufacturing scraps - Graphite anode delamination to material reclamation

[0234] Battery manufacturing scraps are the side products as a result of improving and optimizing manufacturing processes. Given that many gigafactories are still taking steps to develop, the rapid growth of the new production line results in high initial manufacturing scrap rates. It emphasizes the importance of direct recycling of such side products.

[0235] In this case study, the re-remanufacturing of cathodes and anodes from battery manufacturing scraps after ice-stripping delamination of the invention was demonstrated. A schematic representation of the ice-stripping delamination process performed on the manufacturing scraps and the direct manufacturing towards new electrodes with reclaimed powders is provided in Figure 14. Given the fewer surface side products of the manufacturing scraps, the delamination process was easier compared to the EoL cells. The reclaimed Al current collector of the cathode (Figure 15 a) shows smooth surfaces after delamination. However, the Cu current collector of the anode has some features of scratches, wrinkles or calendering traces on the surface as shown in Figure 16a. The morphologies of reclaimed cathode (see Figure 15b) and anode (see Figure 16b) powders demonstrated that the ice- stripping delamination technique of the invention is damage- free.

[0236] The reclaimed black masses were collected, dried at 120 °C overnight and directly reprocessed into slurry and coated as new anodes. To check the direct feasibility, the half-cell was re-manufactured with reclaimed graphite powder as delaminated (Scrap-R- as delaminated), grounded and sieved with a 53 pm mesh (Scrap-R-ground), and without additional conductive carbons (Scrap-R-no C45). Direct use the reclaimed graphite power with or without further grinding showed negligible effect upon the initial charge / discharge profiles as presented in Figure 17. As expected, additional conductive carbon improved specific capacity. The results strengthen the feasibility of ice-stripping delamination techniques in providing direct recycling circle economy.

[0237] Sustainability and environmental impact

[0238] The delamination method of the invention involves the freezing of a liquid (which may be water) to facilitate delamination of the electrode material from the current collector and has been demonstrated with low-cost equipment, and has the potential to be scaled up to a continuous process. Due to the physical electrode material delamination process and low operation temperatures used, the method of the invention does not release any VOCs (volatile organic components) and environmentally harmful toxins that can be produced through high-temperature black-mass burning methods of the prior art. Moreover, due to the flexibility of the method and chemically non-destructive conditions used, any type of electrode material composition can be delaminated from a current collector without chemical transformation or decomposition. Additionally, this procedure minimizes the generation of solid or gaseous wastes. The carbon footprint for the process of the invention consists only of carbon emission due to energy consumption to cool the surface down to operating temperature.

[0239] Conclusions Without wishing to be bound by theory, the delamination method of the invention involves using sub-zero temperatures / frozen solids to benefit from thermal conductivity differences between frozen solids and electrode materials to allow for delamination of electrode materials from current collectors through the formation of a bond between electrode materials and frozen solids, which is stronger than the bond between the electrode materials and current collectors in an electrode.

[0240] The delamination method of the invention has been designed, demonstrated and optimised as an easy and rapid delamination technique for direct recycling of both cathodes and anodes. High separation efficiency (up to 96%) was achieved for the inventive method.

[0241] Compared to many delamination methods of the prior art, the method of the invention offers: high delamination yield; high purity of recovered materials with original morphologies and sizes and which can be directly recycled; limited liquid waste and virtually no contamination; good current collector grade for recovery and recycling or even direct reuse; a binder agnostic approach (capable of delaminating electrode materials comprising both water-soluble and non-water-soluble binders); possibility to scale up for battery recycling of electrode scraps from gigafactories and end-of-life batteries.

[0242] Reclaimed cathode and anode electrode materials were shown to be directly reused and remanufactured into full battery cells, showing excellent potential for active material direct recycling.

[0243] Supplementary Experimental

[0244] Cell disassembly The PW cathodes and HC anodes used in the delamination method of the invention were obtained from end-of-life A7 size pouch cells. The PW cathode electrode material contained 93 wt.% PW, 3 wt.% CMC / SBR (1:2) binder, and 3 wt.% C65 (conductive additive). The HC anode electrode material contained 96 wt.% HC, 3 wt.% CMC / SBR (1:2) binders, and 1 wt.% C45 (conductive additive). The coating weights of the cathode and anode were, respectively, 150 g / m2and 70 g / m2.

[0245] The end-of-life A7 pouch cells were discharged and carefully opened in a fume hood after slowly releasing any gases that were generated during the charge-discharge cycling of the cells. The whole cell bodies were disconnected from the casing by cutting the tabs. The separator was zig-zag un-wrapped to separate cathodes from anodes. The disassembled electrodes were soaked in isopropyl alcohol (IP A) overnight before drying them at 60 °C in a vacuum oven overnight. The dried electrodes were then ready for delamination.

[0246] Delamination by ball-milling and sonication (prior art method)

[0247] The classical ball-milling and sonication delamination technique used to compare the results obtained with the “ice- stripping” process of the invention was performed as follows.

[0248] In this process, the electrodes were cut into small pieces of roughly 1 cm2area and placed in a beaker which was filled with deionised water (H2O / Coating weight ratio is 20:1). The beaker was placed in a sonicator bath running at full power at 40 °C for Ih. As the separation under these conditions was not sufficient, zirconia balls were added in the

[0249] HDPE bottle in order to improve the separation efficiency; the contents of the beaker were poured in it and placed on a roller mill for 3h. Further, the separated electrode material and current collector were collected by filtration followed by centrifugation.

[0250] Characterisation methods

[0251] X-ray diffraction

[0252] The structural characteristic of the Prussian white and hard carbon before and after delamination were determined by X-ray diffraction using a Bruker D8 Advance instrument with Cu Ka radiation source. The X-ray diffraction data were recorded at a scan rate of 1 °min1in the 20 range between 10° and 70° at 40 KV and 30mA.

[0253] Scanning electron microscopy and energy dispersive spectroscopy

[0254] Scanning electron microscopy with a field-emission SEM microscope (Sigma, Carl Zeiss, Germany) equipped with an energy-dispersive spectrometer (EDS) (Xmax 50, Oxford Instruments) was used to characterize the surface of the electrodes after cycling. SEM images were captured at 10 kV (1.6 nA) when a high-performance ion conversion and electron detector was employed, or 20 kV (8.0 nA) when a secondary electron detector was employed.

[0255] Electrochemical characterisations

[0256] When the reclaimed Prussian white and hard carbon were re-manufactured into electrodes, electrochemical characterizations were carried out in both half-cell and fullcell configurations.

[0257] The reclaimed Prussian White (re-PW) cathode material was made into an electrode with 93 wt.% re-PW, 3 wt.% CMC / SBR binders and 4 wt.% C65 (conductive additive) using a slurry cast process. The reclaimed hard carbon (re-HC) cathode material was made into a negative electrode containing 96 wt.% re-HC, 3 wt.% CMC / SBR binders and 1 wt.% C45 (conductive additive). The cathodes were dried in vacuum (~10-3mbar) at 150 °C overnight and the HC anodes were dried at 120 °C overnight prior to being transferred into a glovebox. In a three-electrode Swagelok cell system, a sodium metal disc was used as both the counter electrode and reference electrode. Reclaimed HC anodes with diameter 12 mm were used as working electrodes with 90 pl of electrolytes.

[0258] The electrochemical performance of the full cells were evaluated in 2032-type coin cells, with PW / re-PW cathode (12 mg / cm2), HC / re-HC anode (8.5 mg / cm2), separated by Celgard polymer containing enough electrolyte to wet the components (~75 pl). Each electrochemical test was performed using three independently produced cells to show standard deviations.

[0259] The above embodiments are described by way of example only. Many variations are possible without departing from the scope of the invention as defined in the appended claims.

Claims

CLAIMS1. A method of separating an electrode material from an electrode, the method comprising the steps of: a. Providing an electrode comprising an electrode material adhered to a current collector; b. Adhering the electrode material to a frozen solid; c. Delaminating the current collector from the electrode material when the electrode material is adhered to the frozen solid to provide a free electrode material and a free current collector; and d. Recovering the free electrode material.

2. A method as claimed in claim 1 , wherein step (a) comprises isolating the electrode from a battery.

3. A method as claimed in any preceding claim, wherein the electrode is an anode or a cathode.

4. A method as claimed in any preceding claim, wherein the electrode comprises a layered arrangement of the electrode material and the current collector.

5. A method as claimed in claim 4, wherein the electrode comprises two layers of electrode material held on either side of a layer of the current collector.

6. A method as claimed in any preceding claim, wherein the current collector comprises a metal.

7. A method as claimed in any preceding claim, wherein the electrode material comprises an active material that comprises an alkali metal or that comprises carbon.

8. A method as claimed in any preceding claim, wherein the electrode material comprises at least one binder.

9. A method as claimed in any preceding claim, wherein the electrode material comprises at least one conductive additive, which may be independently selected from the group consisting of: carbon black, graphene, carbon nano tubes, carbon fibres, and combinations thereof.

10. A method as claimed in any preceding claim, wherein the frozen solid is independently selected from the group consisting of: ice, a frozen organic species, a frozen inorganic species, and combinations thereof.

11. A method as claimed in any preceding claim, wherein step (b) comprises directly contacting the electrode material with the frozen solid to adhere the electrode material to the frozen solid.

12. A method as claimed in any one of claims 1 to 10, wherein step (b) comprises first contacting the electrode material with a liquid, and then freezing the liquid to adhere the electrode material to the frozen solid.

13. A method as claimed in claim 12, wherein the liquid is independently selected from the group consisting of: water or an aqueous solution, an organic liquid, an inorganic liquid, and combinations thereof.

14. A method as claimed in claim 12 or 13, wherein the step of contacting the electrode material with the liquid in step (b) comprises submerging the electrode material in the liquid.

15. A method as claimed in claim 12 or 13, wherein the step of contacting the electrode material with the liquid in step (b) comprises applying the liquid to a support and contacting the electrode material with the liquid on the support.

16. A method as claimed in claim 12 or 13, wherein the step of contacting the electrode material with the liquid in step (b) comprises applying the liquid to the electrode material or coating the electrode material with the liquid, and preferably spray-coating the electrode material with the liquid.

17. A method as claimed in claim 16, wherein step (b) comprises applying the liquid to at least a portion of the electrode material or coating at least a portion of the electrode material with the liquid, contacting said portion of the electrode material comprising the liquid with a support, and then freezing the liquid whilst the electrode material comprising the liquid is in contact with the support.

18. A method as claimed in any one of claims 12 to 17, wherein the step of freezing the liquid in step (b) comprises subjecting the electrode material in contact with the liquid to a temperature of no greater than 0 °C, preferably to a temperature of no greater than -5 °C.

19. A method as claimed in claim 18, wherein the electrode material in contact with the liquid is subjected to a temperature of no greater than 0 °C for at least5 minutes.

20. A method as claimed in any one of claims 12 to 19, wherein the step of freezing the liquid in step (b) is performed in a freezer.

21. A method as claimed in any preceding claim, wherein the delamination step in step (c) comprises peeling the current collector away from the electrode material whilst the electrode material is in contact with the frozen solid.

22. A method as claimed in any preceding claim, wherein step (d) comprises the step of melting frozen solid that is still in contact with the free electrode material to separate the free electrode material from the frozen solid.

23. A method as claimed in claim 22, wherein the step of melting the frozen solid still in contact with the free electrode material comprises subjecting the free electrode material to a temperature above 0 °C.

24. A method as claimed in any preceding claim, wherein the free electrode material comprises at least one binder, and the method further comprises the step of separating the at least one binder from the free electrode material.

25. A method as claimed in claim 24, wherein the at least one binder comprises a water-based and / or non- water-based binder.

26. A method of separating a battery electrode material from a battery, the method comprising the steps of: a. Providing a battery; b. Isolating an electrode from the battery, the electrode comprising an electrode material adhered to a current collector; c. Adhering the electrode material to a frozen solid; andd. Delaminating the current collector from the electrode material when the electrode material is adhered to the frozen solid to provide a free electrode material and a free current collector; and e. Recovering the free electrode material.

27. A method of recycling a battery, the method comprising steps (a) to (d) of the method as claimed in claim 26, and further comprising the step of: e. Recovering and reusing the free electrode material and / or free current collector.

28. A method as claimed in claim 26 or 27, wherein the battery is an alkali metal ion battery.

29. A method as claimed in any one of claims 26 to 28, wherein step (b) comprises separating the electrode from one or more other components of the battery, which may be independently selected from the group consisting of: a cell container, a separator, an electrolyte, and combinations thereof.

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