Peeling method of composite

Abstract

The present invention provides a method for stripping a composite by immersing the composite in a stripping solution, wherein the composite comprises a metal substrate and a coating applied to one or both sides of the metal substrate, wherein the coating comprises a polymeric binder, and wherein the polymeric binder comprises an aqueous copolymer. The use of a stripping solution comprising an alkali metal phosphate allows for a complete stripping of the composite in an efficient and extremely fast manner. Furthermore, the stripping method disclosed herein avoids complex separation procedures, contamination and corrosion of the metal substrate, and enables excellent material recovery. An application of the method for stripping an electrode of a battery is disclosed herein.

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of material recycling methods. In particular, the present invention relates to a method of stripping a composite comprising a metal substrate and a coating applied on one or both sides of the metal substrate. BACKGROUND

[0002] The increasing urbanization, rapid development of technological innovation and the consequent frequent replacement of products or disposal of waste consumables, leads to a reduction in product life and / or overproduction of waste. With the emergence of increasingly serious problems associated with overproduction of waste, such as harmful effects on human health, adverse effects on the environment and consumption of resources, there has been an urgent need for rapid action worldwide to address these complex problems using various waste treatment methods.

[0003] Recycling, as a key component in the hierarchy of waste reduction, aims to recover useful materials from waste for reuse. The recycling of materials can protect natural resources, reduce energy consumption (and thus production costs) associated with the extraction of raw materials, and reduce environmental impacts by reducing greenhouse gas and SO x emissions. As material recycling can bring great benefits, developing efficient material recycling methods is crucial to achieving a circular economy.

[0004] The term "composite" refers to a metal substrate containing a coating applied on one or both sides of the metal substrate, wherein the coating comprises a polymeric binder. The polymeric binder is responsible for the adhesion between the coating and the metal substrate. The application of a coating on a metal substrate is a method of changing the surface properties to meet the performance requirements in various technical applications. Some applications of the coating include adhesives, formation of barrier layers, scratch and wear resistance, chemical resistance, wettability, and biocompatibility. Coating a metal substrate is often used in battery production, membrane technology, packaging materials, circuit board printing, electrical wires or cables, and biomedical applications. Therefore, separating the coating from the metal substrate is a technology that is widely used in material recycling.

[0005] However, for products that have reached their useful life or for product rejects that can be immediately recycled during the production process, there are some difficulties in the step of separating the composite contained in the product into a coating and a metal substrate during the recycling process.

[0006] In one aspect, the peeling of the composite can occur within the bulk of the coating rather than at the coating-metal substrate interface. The coating can then not be completely peeled from the metal substrate, but rather, portions of the coating can remain intact on the metal substrate. This can result in an undesirable loss of coating material that cannot be directly recovered from the peeling process, as well as a recovered metal substrate having a high level of contamination due to the presence of the residual coating, requiring the introduction of a subsequent separation process.

[0007] On the other hand, the peeling of the coating from the metal substrate can be very inefficient, requiring several hours. The prolonged exposure of the composite to the harsh peeling conditions can likely cause side effects, such as corrosion, dissolution and damage of the materials within the composite, particularly the metal substrate, as well as the production of side reaction products.

[0008] Polymeric binders commonly used to be responsible for the adhesion between the coating and the metal substrate, such as polyvinylidene fluoride (PVDF), have the disadvantage that they are not soluble in water, and in fact these polymers can only be dissolved in some specific organic solvents, such as N-methyl-2-pyrrolidone (NMP). NMP is flammable and toxic, thus requiring special handling. An NMP recovery system must be installed during the drying process to recover the NMP vapors. This will generate a huge cost in the manufacturing process, since the establishment of such a recovery system requires a large capital investment. Therefore, for applications where exposure to a humid environment during the manufacturing process is not a significant problem, the use of a polymeric binder that utilizes a cheaper and more environmentally friendly solvent (such as an aqueous solvent, most commonly water) is preferred in the present invention, since it can reduce the huge capital cost of the recovery system.

[0009] Polymeric binders suitable for water-based coatings exhibit excellent dispersibility and stability in water and are capable of promoting extremely strong coating-metal substrate adhesion. However, it is precisely the extremely strong coating-metal substrate adhesion that occurs when these polymeric binders are used that makes the peeling of the water-based coating from the metal substrate to which it is attached extremely challenging. In order to better optimize the performance of these water-based binders, copolymers containing structural units derived from various different monomers can be used, but the peeling remains quite challenging when these copolymer binders are used in coatings.

[0010] The peeling of the composite is achieved by the breaking and / or cleaving of the bonds between the polymeric binder within the coating and the metal substrate at the coating-metal substrate interface. Therefore, in order to achieve a high-speed, high-recovery, high-safety peeling with a lower amount of additional material used and at a lower cost, one important goal is to more efficiently break and / or cleave the bonds between the polymeric binder within the coating and the metal substrate.

[0011] Attempts have been made to develop methods to achieve complete stripping of the composite. Korean Patent Application Publication No. 20130099568A discloses a method to separate a composite comprising a polymer film coated on a metal surface by carbonizing the polymer using electromagnetic induction. The metal-polymer composite is first subjected to a pre-treatment step in which the polymer-metal composite is put into an induction furnace so as to receive the maximum influence of magnetic density per unit area during induction heating, making the movement of electrons on the metal surface more active. By induction heating, the metal-polymer composite is then heated to 500-900°C, which weakens the adhesion between the polymer and the metal surface and subsequently causes thermal decomposition and carbonization of the polymer coated on the metal surface, thereby facilitating separation. This method can significantly save energy by employing induction heating. However, the proposed method results in carbonization of the polymer, which makes the polymer impossible to be recycled. In addition, harmful or toxic pollutants can be generated during the polymer decomposition process.

[0012] In view of the above challenges, there is always a need to develop a unified and simple method to achieve efficient and complete stripping of the composite at the coating-metal substrate interface, wherein the coating of the composite comprises a polymer binder, and wherein the polymer binder is a copolymer. The method for stripping of the composite disclosed herein is to achieve effective breaking and / or cleaving of the bond between the copolymer binder in the coating of the composite and the metal substrate. Therefore, the stripping method that meets these features can be applicable to the composite comprising a copolymer binder. This method can avoid a complicated separation process and contamination of the metal substrate, achieve excellent material recovery rate, and allow the stripping of the composite to be completed in a short time. SUMMARY

[0013] The above needs can be met by various aspects and embodiments disclosed herein. In one aspect, provided herein is a method for stripping a composite by immersing the composite in a stripping solution; wherein the composite comprises a metal substrate and a coating applied on one or both sides of the metal substrate, wherein the coating comprises a copolymer binder.

[0014] In some embodiments, the metal substrate is selected from the group consisting of stainless steel, titanium, nickel, aluminum, copper, platinum, gold, silver, chromium, zirconium, tungsten, molybdenum, tin, vanadium, zinc, cadmium, iron, cobalt, lead, and alloys thereof.

[0015] In some embodiments, the stripping solution comprises a stripping agent and an aqueous solvent.

[0016] In some embodiments, the stripping agent is an alkali metal phosphate. In some embodiments, the stripping agent is monosodium phosphate, disodium phosphate, trisodium phosphate, monosodium pyrophosphate, disodium pyrophosphate, trisodium pyrophosphate, tetrasodium pyrophosphate, monosodium triphosphate, disodium triphosphate, trisodium triphosphate, tetrasodium triphosphate, pentasodium triphosphate, potassium phosphate monobasic, potassium phosphate dibasic, potassium phosphate tribasic, potassium pyrophosphate monobasic, potassium pyrophosphate dibasic, potassium pyrophosphate tribasic, potassium pyrophosphate tetra basic, potassium triphosphate monobasic, potassium triphosphate dibasic, potassium triphosphate tribasic, potassium triphosphate tetra basic, potassium triphosphate pentabasic, rubidium phosphate monobasic, rubidium phosphate dibasic, rubidium phosphate tribasic, rubidium pyrophosphate monobasic, rubidium pyrophosphate dibasic, rubidium pyrophosphate tribasic, rubidium pyrophosphate tetra basic, rubidium triphosphate monobasic, rubidium triphosphate dibasic, rubidium triphosphate tribasic, rubidium triphosphate tetra basic, rubidium triphosphate pentabasic, cesium phosphate monobasic, cesium phosphate dibasic, cesium phosphate tribasic, cesium pyrophosphate monobasic, cesium pyrophosphate dibasic, cesium pyrophosphate tribasic, cesium pyrophosphate tetra basic, cesium triphosphate monobasic, cesium triphosphate dibasic, cesium triphosphate tribasic, cesium triphosphate tetra basic, cesium triphosphate pentabasic, or a combination thereof.

[0017] The stripping of the composite obtained using the methods provided herein is very fast and simple and does not cause adverse effects such as loss of coating material that cannot be recovered, damage to the coating material, or introduction of impurities in the metal substrate, etc.

[0018] In another aspect, as one of the applications of the present application, the above method can be used for stripping of a battery electrode, wherein the composite is a battery electrode, the metal substrate is a current collector, and the coating is an electrode layer. Provided herein is a method for stripping a battery electrode by immersing the electrode in a stripping solution; wherein the electrode comprises a current collector and an electrode layer coated on one or both sides of the current collector, wherein the electrode layer comprises a copolymer binder.

[0019] The simple use of a stripping solution in the present application to strip the battery electrode at the electrode layer-current collector interface can significantly shorten the time required to achieve complete stripping, maximize the recovery of useful materials, eliminate contamination of the current collector, and does not require subsequent processes. In addition, the method disclosed herein is found to be applicable to the stripping of both cathodes and anodes without causing the problem of corrosion of the electrode active material in the current collector and / or the electrode layer. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A simplified view showing one embodiment of a composite.

[0021] Figure 2 A schematic view showing the structure of the coating-metal substrate interface in the proposed composite.

[0022] Figure 3 A flow chart of one embodiment showing the steps of the stripping of the composite disclosed herein and the subsequent further processing of the components of the composite (i.e. the coating and the metal substrate) after stripping of the composite.

[0023] Figure 4a A cathode layer and current collector recovered after immersing a double-sided coated cathode in a stripping solution in Example 2, wherein the stripping solution comprises 0.05 M tripotassium phosphate and deionized water, and wherein the double-sided coated cathode comprises a copolymer binder, wherein the proportion of structural unit (a) is 49.45% by mole, the proportion of structural unit (b) is 26.48% by mole, and the proportion of structural unit (c) is 24.07% by mole, based on the total number of moles of monomer units in the copolymer binder.

[0024] Figure 4b A cathode layer and current collector recovered after immersing a double-sided coated cathode in a stripping solution in Example 14, wherein the stripping solution comprises 0.25 M tripotassium phosphate and deionized water, and wherein the double-sided coated cathode comprises a copolymer binder, wherein the proportion of structural unit (a) is 23.01% by mole, the proportion of structural unit (b) is 10.00% by mole, and the proportion of structural unit (c) is 66.99% by mole, based on the total number of moles of monomer units in the copolymer binder.

[0025] Figure 5 A recovered cathode of Comparative Example 1, wherein the stripping solution comprises 1 M tripotassium phosphate and deionized water, and wherein the double-sided coated cathode comprises polyvinylidene fluoride (PVDF) as a polymeric binder. DETAILED DESCRIPTION

[0026] In one aspect, provided herein is a method of stripping a composite by immersing the composite in a stripping solution; wherein the composite comprises a metal substrate and a coating applied on one or both sides of the metal substrate, wherein the coating comprises a copolymer binder.

[0027] In another aspect, provided herein is a method of stripping a lithium-ion battery electrode by immersing the electrode in a stripping solution; wherein the electrode comprises a current collector and an electrode layer coated on one or both sides of the current collector, wherein the electrode layer comprises a copolymer binder.

[0028] The term "electrode" refers to either a "cathode" or an "anode".

[0029] The term "positive electrode" is used interchangeably with "cathode". Likewise, the term "negative electrode" is used interchangeably with "anode".

[0030] The term "binder" or "binder material" refers to a chemical compound, mixture of compounds, or polymer used to secure a material in place and adhere it to a conductive metal substrate to form a composite. In some embodiments, the binder refers to a chemical compound, mixture of compounds, or polymer used to secure an electrode material and / or a conductive agent in place and adhere it to a conductive metal component to form an electrode. In some embodiments, the electrode does not include any conductive agent.

[0031] The term "conductive agent" refers to a material that has good electrical conductivity. Thus, a conductive agent is typically mixed with an electrode active material when forming an electrode to improve the electrical conductivity of the electrode. In some embodiments, the conductive agent is chemically active. In some embodiments, the conductive agent is chemically inert.

[0032] The term "composite" refers to a metal substrate that contains a coating applied to one or both sides of the metal substrate, where the metal substrate and the coating can each include one or more layers. The term "component" in the context of a composite refers to the metal substrate and the coating.

[0033] The term "polymer" refers to a compound prepared by the polymerization of the same or different types of monomers. The general term "polymer" includes the terms "homopolymer" and "copolymer."

[0034] The term "aqueous polymer" refers to a polymer that is dispersible in an aqueous solvent (e.g., water) to form a solution or a colloidal system, where the polymer in the colloidal system does not readily self-aggregate.

[0035] The term "homopolymer" refers to a polymer prepared by the polymerization of the same type of monomer.

[0036] The term "copolymer" refers to a polymer prepared by the polymerization of two or more different types of monomers.

[0037] The term "polymeric binder" refers to a binder that has the properties of a polymer. The term "copolymeric binder" refers to a polymeric binder, where the binder is specifically a copolymer.

[0038] The term "unsaturated" as used herein refers to a moiety having one or more unsaturated units.

[0039] The term "alkyl" or "alkyl group" refers to a group having the general formula C n H 2n+1a monovalent group derived from a saturated, unbranched or branched aliphatic hydrocarbon from which one hydrogen atom has been removed, wherein n is an integer or an integer between 1 and 20 or an integer between 1 and 8. Examples of alkyl groups include, but are not limited to, (Ci-C8)alkyl groups, such as methyl, ethyl, propyl, isopropyl, 2-methyl-l -propyl, 2-methyl-2-propyl, 2-methyl-l -butyl, 3-methyl-l -butyl, 2-methyl-3-butyl, 2,2-dimethyl-l -propyl, 2-methyl-l -pentyl, 3-methyl-l -pentyl, 4-methyl-l -pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl, 2,2-dimethyl-l -butyl, 3,3-dimethyl-l -butyl, 2-ethyl-l -butyl, butyl, isobutyl, t-butyl, pentyl, isopentyl, neopentyl, hexyl, heptyl, and octyl. Longer alkyl groups include nonyl and decyl groups. Alkyl groups can be unsubstituted or substituted with one or more suitable substituents. Further, alkyl groups can be branched or unbranched. In some embodiments, alkyl groups contain at least 2, 3, 4, 5, 6, 7, or 8 carbon atoms.

[0040] The term "cycloalkyl" or "cycloalkyl group" refers to a saturated or unsaturated cyclic non-aromatic hydrocarbon group having a single ring or multiple condensed rings. Examples of cycloalkyl groups include, but are not limited to, (C3-C7)cycloalkyl groups, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl, as well as saturated cyclic terpenes and saturated bicyclic terpenes, and (C3-C7)cycloalkenyl groups, such as cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, and cycloheptenyl, as well as unsaturated cyclic terpenes and unsaturated bicyclic terpenes. Cycloalkyl groups can be unsubstituted or substituted with one or two suitable substituents. Further, cycloalkyl groups can be monocyclic or polycyclic. In some embodiments, cycloalkyl groups contain at least 5, 6, 7, 8, 9, or 10 carbon atoms.

[0041] The term "alkoxy" refers to an alkyl group, as previously defined, attached to the parent chain through an oxygen atom. Some non-limiting examples of alkoxy groups include methoxy, ethoxy, propoxy, butoxy, and the like. And the alkoxy groups defined above can be substituted or unsubstituted, where the substituents can be, but are not limited to, deuterium, hydroxyl, amine, halogen, cyano, alkoxy, alkyl, alkenyl, alkynyl, mercapto, nitro, and the like.

[0042] The term "alkenyl" refers to an unsaturated straight-chain, branched, or cyclic hydrocarbon group containing one or more carbon-carbon double bonds. Examples of alkenyl groups include, but are not limited to, ethenyl, 1 -propenyl, and 2-propenyl, which can be optionally substituted on one or more carbon atoms of the group.

[0043] The term "aryl" or "aryl group" refers to an organic group derived by removing a hydrogen atom from a monocyclic or polycyclic aromatic hydrocarbon. Non-limiting examples of aryl groups include phenyl, naphthyl, benzyl, tolanyl, sexiphenyl, phenanthrenyl, anthracenyl, coronenyl, and tolanylphenyl. An aryl group can be unsubstituted or substituted with one or more suitable substituents. Further, an aryl group can be monocyclic or polycyclic. In some embodiments, an aryl group contains at least 6, 7, 8, 9, or 10 carbon atoms.

[0044] The term "aliphatic" refers to a C1to C 30 alkyl group, a C2to C 30 alkenyl group, a C2to C 30 alkynyl group, a C1to C 30 alkylene group, a C2to C 30 alkenylene group, or a C2to C 30 alkynylene group. In some embodiments, an alkyl group contains at least 2, 3, 4, 5, 6, 7, or 8 carbon atoms.

[0045] The term "aromatic" refers to a group comprising an aromatic hydrocarbon ring, which optionally includes heteroatoms or substituents. Examples of such groups include, but are not limited to, phenyl, tolyl, biphenyl, o-terphenyl, m-terphenyl, p-terphenyl, naphthyl, anthryl, phenanthryl, pyrenyl, triphenylenyl, and derivatives thereof.

[0046] The term "substituted" used in connection with a compound or chemical moiety means that at least one hydrogen atom of the compound or chemical moiety is replaced with another chemical moiety. Examples of substituents include, but are not limited to, halogen; alkyl; heteroalkyl; alkenyl; alkynyl; aryl; heteroaryl; hydroxyl; alkoxy; amine; nitro; thiol; sulfide; imine; cyano; amide; phosphonato; phosphinate; carboxyl; thiocarbonyl; sulfonyl; sulfonamide; acyl; formyl; acyloxy; alkoxycarbonyl; carbonyl; haloalkyl (e.g., trifluoromethyl); carbocyclic cycloalkyl, which can be monocyclic or fused or non-fused polycyclic (e.g., cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl), or heterocyclic cycloalkyl, which can be monocyclic or fused or non-fused polycyclic (e.g., pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, or thiazinyl); carbocyclic or heterocyclic, monocyclic or fused or non-fused polycyclic aryl (e.g., phenyl, naphthyl, pyrrolyl, indolyl, furanyl, thiophenyl, imidazolyl, oxazolyl, isoxazolyl, thiazolyl, triazolyl, tetrazolyl, pyrazolyl, pyridyl, quinolyl, isoquinolyl, acridyl, pyrazinyl, pyridazinyl, pyrimidinyl, benzimidazolyl, benzothiophenyl, or benzofuranyl); amino (primary, secondary, or tertiary); o-lower alkyl; o-aryl, aryl; aryl-lower alkyl; -CO2CH3; -CONH2; -OCH2CONH2; -NH2; -SO2NH2; -OCHF2; -CF3; -OCF3; -NH(alkyl); -N(alkyl)2; -NH(aryl); -N(alkyl)(aryl); -N(aryl)2; -CHO; -CO(alkyl); -CO(aryl); -CO2(alkyl); and -CO2(aryl); and these moieties can also be optionally substituted with a fused ring structure or a bridged structure (e.g., -OCH2O-). These substituents can optionally be further substituted with substituents selected from these groups. Unless otherwise indicated, all chemical groups disclosed herein can be substituted.

[0047] The term "halogen" or "halo" refers to F, CI, Br, or I.

[0048] The term "monomer unit" refers to a constituent unit provided to a structure of a polymer by a single monomer.

[0049] The term "structural unit" refers to the total monomer units provided by the same monomer type in a polymer.

[0050] The term "acid salt group" refers to an acid salt formed when an acid reacts with a base. In some embodiments, the proton of the acid is replaced with a metal cation. In some embodiments, the proton of the acid is replaced with an ammonium ion.

[0051] The term "planetary mixer" refers to an apparatus that can be used to mix or agitate different materials to produce a homogeneous mixture, which consists of paddles that perform planetary motion within a container. In some embodiments, a planetary mixer contains at least one planetary paddle and at least one high-speed dispersing paddle. The planetary paddle and the high-speed dispersing paddle rotate on their respective shafts and also rotate continuously around the container. The rotational speed can be expressed in units of revolutions per minute (rpm), which refers to the number of revolutions a rotating body completes in one minute.

[0052] The term "ultrasonic generator" refers to an apparatus capable of applying ultrasonic energy to agitate particles in a sample. Any ultrasonic generator that can disperse the slurries disclosed herein can be used herein. Some non-limiting examples of ultrasonic generators include ultrasonic baths, probe-type ultrasonic generators, and ultrasonic flow cells.

[0053] The term "ultrasonic bath" refers to a device in which ultrasonic energy is transmitted through the walls of the ultrasonic bath container into a liquid sample.

[0054] The term "probe-type ultrasonic generator" refers to an ultrasonic probe that is immersed in a medium for direct ultrasonic treatment. The term "direct ultrasonic treatment" refers to ultrasonic coupling directly into the treatment fluid.

[0055] The term "ultrasonic flow cell" or "ultrasonic reactor chamber" refers to an apparatus that performs ultrasonic treatment in a flow mode. In some embodiments, the ultrasonic flow cell is a single-channel, multi-channel, or recirculating configuration.

[0056] The term "applying" refers to the act of laying or spreading a substance on a surface.

[0057] The term "current collector" refers to any electrically conductive layer that is in contact with an electrode layer and is capable of conducting electrical current to the electrode during discharge or charge of a secondary battery. Some non-limiting examples of current collectors include a single electrically conductive metal layer or substrate and a single electrically conductive metal layer or substrate that is covered with an electrically conductive coating, such as a carbon black-based coating. The electrically conductive metal layer or substrate can be in the form of a foil or a porous body having a three-dimensional network structure. In some embodiments, the three-dimensional porous current collector is coated with a conformal carbon layer.

[0058] The term "electrode layer" refers to a coating that is in contact with a current collector and contains an electrochemically active material. In some embodiments, an electrode layer is made by applying a coating on a current collector. In some embodiments, an electrode layer is on one or both sides of a current collector. In other embodiments, a three-dimensional porous current collector is covered with a conformal electrode layer. Thus, an electrode is a composite in which the current collector is a metal substrate and the electrode layer is a coating.

[0059] The term "room temperature" refers to an indoor temperature of about 18 °C to about 30 °C, e.g., 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 °C. In some embodiments, room temperature refers to a temperature of about 20 °C + / - 1 °C or + / - 2 °C or + / - 3 °C. In other embodiments, room temperature refers to a temperature of about 22 °C or about 25 °C.

[0060] The term "solids content" refers to the amount of non-volatile material remaining after evaporation.

[0061] The term "peel strength" refers to the magnitude of force required to separate a current collector and an electrode active material coating adhered to one another. It is a measure of the adhesive strength between the two materials, typically expressed in N / cm.

[0062] The term "adhesion strength" refers to the magnitude of force required to separate a current collector and a polymer binder coating adhered to one another. It is a measure of the adhesive strength between the two materials, typically expressed in N / cm.

[0063] The term "C-rate" refers to the charge or discharge rate of a battery in terms of its total storage capacity expressed in ampere-hours (Ah) or milliampere-hours (mAh). For example, a rate of 1C means that all of the stored energy is used in one hour; 0.1C means that 10% of the energy is used in one hour or the entire energy is used in 10 hours; and 5C means that the entire energy is used in 12 minutes.

[0064] The term "ampere-hour (Ah)" refers to the unit used in describing the storage capacity of a battery. For example, a 1 Ah capacity battery can provide a 1 ampere current for 1 hour or a 0.5 ampere current for two hours, etc. Thus, 1 ampere-hour (Ah) is equivalent to 3,600 coulomb charge. Similarly, the term "milliampere-hour (mAh)" also refers to the unit used in describing the storage capacity of a battery and is 1 / 1,000 of an ampere-hour.

[0065] The term "battery cycle life" refers to the number of complete charge / discharge cycles that a battery can perform before its nominal capacity decreases to less than 80% of its initial rated capacity.

[0066] The term "capacity" is a characteristic of an electrochemical cell, referring to the total amount of electrical charge that an electrochemical cell (e.g., a battery) can hold. Capacity is typically expressed in ampere-hours. The term "specific capacity" refers to the capacity output of an electrochemical cell (e.g., a battery) per unit weight, typically expressed in Ah / kg or mAh / g.

[0067] In the following description, all numerical values ​​disclosed herein are approximations, regardless of whether the terms "about" or "approximately" are used in conjunction. They may vary by 1%, 2%, 5%, or sometimes 10% to 20%. Whenever a lower bound R is disclosed... L and upper limit R U When the numerical range is specified, any value within that range is specifically disclosed. Specifically, the following values ​​within that range are specifically disclosed: R = R L +k*(R U -R L ), where k is a variable from 0% to 100%. Furthermore, any numerical range defined by the two R values ​​determined in the above manner is also specifically disclosed.

[0068] In this specification, all instances of singular usage include instances of plural usage, and vice versa.

[0069] As used herein, a “composite” refers to a metal substrate containing a coating applied to one or both sides of a metal substrate, wherein the metal substrate and the coating may each comprise one or more layers, and wherein the coating comprises a polymeric binder. In some embodiments, the polymeric binder is a copolymer, i.e., a copolymer binder. Figure 1 A simplified view of the composite 100 is shown. The composite 100 comprises a metal substrate 101 and a coating 102 applied to one side of the metal substrate 101. Applying a coating to a metal substrate, i.e., forming a composite, is one of the most common techniques for altering the surface properties of a metal substrate to meet the performance requirements of a variety of applications. Coatings are frequently used for a variety of purposes, including protection (e.g., chemical resistance, corrosion resistance, scratch and abrasion resistance), adhesion, modification of wettability, or biocompatibility.

[0070] The adhesion between the composite coating and the metal substrate is achieved through the interaction between the polymer binder contained in the coating and the surface of the metal substrate on which the coating is applied. Copolymer binders compatible with aqueous solvents (most commonly water) can firmly adhere the coating to the metal substrate. Therefore, such copolymer binders are preferred in this invention. Furthermore, because these copolymer binders exhibit good dispersibility and stability in water, water-based coatings containing these copolymer binders will have good processability in terms of formation, storage, and use.

[0071] In some embodiments, the substrate is a metallic substrate. In some embodiments, the substrate is selected from the group consisting of stainless steel, titanium, nickel, aluminum, copper, platinum, gold, silver, chromium, zirconium, tungsten, molybdenum, tin, vanadium, zinc, cadmium, iron, cobalt, lead, and alloys thereof.

[0072] Generally, the metal substrate is exposed to ambient air for a certain period of time before a coating is applied to the surface of the metal substrate. Ambient air mainly contains oxygen, water and several organic and inorganic substances. When the metal substrate is exposed to the naturally occurring oxygen of the atmosphere, the formation of metal oxides on the surface of the metal substrate is inevitable. For example, the metal aluminium is naturally very reactive with the oxygen of the atmosphere, which can initiate the formation of aluminium oxide on the exposed aluminium surface. Aluminium oxide protects the underlying aluminium from further oxidation and therefore aluminium has a good corrosion resistance. When the metal oxide on the surface of the metal substrate comes into contact with the moisture of the ambient air, the metal oxide is hydroxylated, which leads to a surface of the metal oxide rich in hydroxyl groups (-OH).

[0073] The hydroxyl group of the surface of the metal substrate consists of an H atom covalently bound to an O atom of higher electronegativity and an electronegative O atom with a pair of lone electrons in the outermost electron shell. Within the hydroxyl group, the hydrogen atom is able to form a hydrogen bond to another molecule containing a highly electronegative atom, such as O, N or F, and the oxygen atom is able to accept a hydrogen bond from a hydrogen atom of another molecule similarly bound to a highly electronegative atom, such as O, N or F.

[0074] At the same time, the metallic part of the substrate is still present on the surface of the metal substrate in the form of a partially positively charged metal species (M δ+ ), for example in the form of a metal oxide formed on the surface of the metal substrate.

[0075] Figure 2 Schematic representation of the coating-metal substrate interface structure of the proposed composite shown as 200. Hydroxyl (-OH) groups, partially positively charged metal species (M δ+ ) and oxygen (O) atoms of the metal oxide are all present on the surface of the metal substrate 201. The copolymer binder within the coating 202 and / or at the surface of the coating 202 comprises structural units derived from carboxylic acid group containing monomers. In this case, the structural units derived from carboxylic acid group containing monomers comprise carboxylate groups, wherein the carboxylate groups are salts of carboxylic acid groups.

[0076] The oxygen (O) and hydrogen (H) atoms present in the copolymer binder can interact with the O and / or H atoms of the hydroxyl groups of the surface of the metal substrate and the O atoms in the metal oxide via hydrogen bonding. In addition, the anions of the carboxylate groups (COO - in this case) contained in the copolymer binder can interact with the M δ+ species of the surface of the metal substrate via ion-dipole interactions. Thus, hydrogen bonding and / or ion-dipole attraction can occur between the coating and the metal substrate and both types of interactions contribute significantly to the adhesion of the coating to the surface of the metal substrate.

[0077] The co-polymer binders disclosed herein are formulated to provide very strong coating-metal substrate adhesion for various applications. However, when the product containing the composite reaches the end of its useful life or service life, or when a product reject is produced during the manufacturing process, this strong adhesion presents an additional challenge in subsequent recycling steps where the coating is separated from the metal substrate to which it is attached.

[0078] The separation of the coating from the metal substrate in the composite is achieved by the breaking and / or cleaving of the bonds between the co-polymer binder in the coating and the metal substrate surface. The co-polymers, which exhibit different specific properties of the different components, require different methods to separate the coating from the metal substrate. Accordingly, the methods of the present invention are specifically developed to separate the composite by breaking and / or cleaving the bonds between the aqueous co-polymer binders disclosed herein and the metal substrate surface.

[0079] The present invention provides a method of separating a composite by immersing the composite in a separation solution, wherein the composite comprises a metal substrate and a coating applied to one or both sides of the metal substrate, wherein the coating comprises a co-polymer binder.

[0080] In some embodiments, the separation of the composite occurs at the coating-metal substrate interface.

[0081] In some embodiments, the separation solution comprises a separation agent and an aqueous solvent. In some embodiments, the separation agent is a water-soluble alkali metal phosphate. In some embodiments, the aqueous solvent consists only of water.

[0082] In the separation solution, the alkali metal phosphate reacts with water to form hydroxide ions. These generated ions can enter the interface between the co-polymer binder and the metal substrate surface. The ions break the hydrogen bonds and ion-dipole interactions between the binder and the substrate. The aqueous solvent (e.g. water) present in the separation solution also breaks the ion-dipole interactions between the co-polymer binder in the coating and the metal substrate surface. These aqueous solvent molecules further act to solvate the co-polymer, forming a solvent shell (a hydration shell in the case of water), which greatly reduces the strength of the electrostatic interactions between the co-polymer binder in the coating and the metal substrate.

[0083] In some embodiments, some of the functional groups within the copolymer that are capable of dissociating in water, such as carboxylic acid groups, do not fully dissociate in water. The phosphate ions react with water to produce hydroxide ions or the phosphate ions themselves can further neutralize the undissociated functional groups, thereby forming the corresponding anions, such as carboxylate anions when the functional groups present are carboxylic acid groups. Water has a stronger attraction to such anions (e.g., carboxylate) than to the undissociated functional groups. With the ionization of these dissociable functional groups, the solvation effect of the ionized functional groups in water is stronger, thereby allowing the interaction between the polymer and the substrate to be weakened more effectively. This thus leads to the delamination of the coating.

[0084] Accordingly, the method disclosed herein aims to achieve the delamination of the composite by using a delaminating solution to disrupt and / or break the hydrogen bonding and / or ion-dipole interactions between the coating and the metal substrate surface, where the coating comprises a copolymer binder. The method is simple and does not require the involvement of a complex separation process. The proposed method ensures the complete delamination of the composite at the coating-metal substrate interface without contaminating the metal substrate, thereby achieving excellent material recovery and enabling the delamination of the composite to be achieved efficiently and quickly.

[0085] The non-ionized copolymer functional groups do not interact with the metal substrate surface through ion-dipole interactions. The use of an aqueous solvent alone as the delaminating solution can not be sufficient to completely delaminate the coating from the metal substrate, as the solvation effect of the aqueous solvent on these non-ionized copolymer functional groups will be significantly lower; and the interaction between these copolymer functional groups within the coating and the metal substrate surface (mainly hydrogen bonding) will not typically be disrupted and reduced to the extent that enables the complete delamination of the composite.

[0086] Accordingly, both the delaminating agent and the aqueous solvent should be used in combination as the delaminating solution to achieve excellent delamination of the composite. In some embodiments, the delaminating solution comprises a delaminating agent and an aqueous solvent.

[0087] In some embodiments, the stripping agent is an alkali metal phosphate. In some embodiments, the stripping agent is monosodium phosphate, disodium phosphate, trisodium phosphate, monosodium pyrophosphate, disodium pyrophosphate, trisodium pyrophosphate, tetrasodium pyrophosphate, monosodium triphosphate, disodium triphosphate, trisodium triphosphate, tetrasodium triphosphate, pentasodium triphosphate, monopotassium phosphate, dipotassium phosphate, tripotassium phosphate, monopotassium pyrophosphate, dipotassium pyrophosphate, tripotassium pyrophosphate, tetrapotassium pyrophosphate, monopotassium triphosphate, dipotassium triphosphate, tripotassium triphosphate, tetrapotassium triphosphate, pentapotassium triphosphate, monorubidium phosphate, dirubidium phosphate, trirubidium phosphate, monorubidium pyrophosphate, dirubidium pyrophosphate, trirubidium pyrophosphate, tetra rubidium pyrophosphate, monorubidium triphosphate, dirubidium triphosphate, trirubidium triphosphate, tetra rubidium triphosphate, pentarubidium triphosphate, monocesium phosphate, dicesium phosphate, tricesium phosphate, monocesium pyrophosphate, dicesium pyrophosphate, tricesium pyrophosphate, tetracesium pyrophosphate, monocesium triphosphate, dicesium triphosphate, tricesium triphosphate, tetracesium triphosphate, pentacesium triphosphate, or a combination thereof.

[0088] In some embodiments, the aqueous solvent is a solution containing water as a major component and a volatile solvent (e.g., an alcohol, a lower aliphatic ketone, a lower alkyl acetate, etc.) as a minor component in addition to water. In some embodiments, the proportion of water in the aqueous solvent is from about 51% to about 100%, from about 51% to about 95%, from about 51% to about 90%, from about 51% to about 85%, from about 51% to about 80%, from about 51% to about 75%, from about 51% to about 70%, from about 55% to about 100%, from about 55% to about 95%, from about 55% to about 90%, from about 55% to about 85%, from about 55% to about 80%, from about 60% to about 100%, from about 60% to about 95%, from about 60% to about 90%, from about 60% to about 85%, from about 60% to about 80%, from about 65% to about 100%, from about 65% to about 95%, from about 65% to about 90%, from about 65% to about 85%, from about 70% to about 100%, from about 70% to about 95%, from about 70% to about 90%, from about 70% to about 85%, from about 75% to about 100%, from about 75% to about 95%, or from about 80% to about 100% by weight.

[0089] In some embodiments, the proportion of water in the aqueous solvent is more than 50%, more than 55%, more than 60%, more than 65%, more than 70%, more than 75%, more than 80%, more than 85%, more than 90%, or more than 95% by weight. In some embodiments, the proportion of water in the aqueous solvent is less than 55%, less than 60%, less than 65%, less than 70%, less than 75%, less than 80%, less than 85%, less than 90%, or less than 95% by weight. In some embodiments, the aqueous solvent consists only of water, i.e., the proportion of water in the aqueous solvent is 100% by weight.

[0090] Some non-limiting examples of water include tap water, bottled water, purified water, purified water, distilled water, deionized water, D20, and combinations thereof. In some embodiments, the aqueous solvent is deionized water. The water can be included as part of the stripping solution to form a solvent shell around the copolymer binder of the coating at the coating-metal substrate surface interface and the metal substrate surface. This helps to disrupt the interaction between the copolymer binder of the coating and the metal substrate surface, resulting in complete stripping of the composite.

[0091] Any water-miscible solvent or volatile solvent can be used as the secondary component of the aqueous solvent (i.e., the solvent other than water). Some non-limiting examples of water-miscible solvents or volatile solvents include alcohols, lower aliphatic ketones, lower alkyl acetates, and combinations thereof. The addition of alcohols can increase the solubility of the strippant and decrease the freezing point of water. Some non-limiting examples of alcohols include C1-C4 alcohols, such as methanol, ethanol, isopropanol, n-propanol, t-butanol, n-butanol, and combinations thereof. Some non-limiting examples of lower aliphatic ketones include acetone, dimethyl ketone, methyl ethyl ketone (MEK), and combinations thereof. Some non-limiting examples of lower alkyl acetates include ethyl acetate (EA), isopropyl acetate, propyl acetate, butyl acetate (BA), and combinations thereof. In some embodiments, the aqueous solvent does not include alcohols, lower aliphatic ketones, lower alkyl acetates, or combinations thereof.

[0092] Surfactants are used as additives to the stripping solution to increase the stripping rate. However, the addition of surfactants to the stripping solution will become an impurity in the resulting solution, resulting in decreased product purity or the need for time and money to develop a separation system to remove the surfactants. In addition, surfactants are harmful to the environment upon discharge and some surfactants can also be harmful to health. Therefore, in some embodiments, no surfactants are added to the stripping solution. In some embodiments, the stripping solution is free of cationic surfactants, anionic surfactants, non-ionic surfactants, and amphoteric surfactants.

[0093] In some embodiments, the peeling solution does not include anionic surfactants including fatty acid salts; alkyl sulfate salts; polyoxyalkylene alkyl ether acetates; alkyl benzene sulfonate salts; polyoxyalkylene alkyl ether sulfate salts; higher fatty acid amide sulfonate salts; N-acylsarcosin salts; alkyl phosphate salts; polyoxyalkylene alkyl ether phosphate salts; long chain sulfosuccinate salts; long chain N-acyl glutamate salts; polymers and copolymers comprising acrylic acid, acid anhydrides, esters, vinyl monomers, and / or olefins and their alkali metal, alkaline earth metal, and / or ammonium salt derivatives; polycarboxylate salts; formalin condensates of naphthalene sulfonic acid; alkyl naphthalene sulfonic acids; naphthalene sulfonic acids; alkyl naphthalene sulfonate salts; formalin condensates of acids and naphthalene sulfonate salts (such as their alkali metal, alkaline earth metal, ammonium, or amine salts); melamine sulfonic acid; alkyl melamine sulfonic acids; formalin condensates of melamine sulfonic acid; formalin condensates of alkyl melamine sulfonic acids; alkali metal, alkaline earth metal, ammonium, and amine salts of melamine sulfonic acid; lignosulfonic acid; and alkali metal, alkaline earth metal, ammonium, and amine salts of lignosulfonic acid.

[0094] In some embodiments, the peeling solution does not include cationic surfactants including alkyl trimethyl ammonium salts such as stearyl trimethyl ammonium chloride, dodecyl trimethyl ammonium chloride, and hexadecyl trimethyl ammonium bromide; dialkyl dimethyl ammonium salts; trialkyl methyl ammonium salts; tetraalkyl ammonium salts; alkyl amine salts; benzalkonium salts; alkyl pyridinium salts; and imidazolium salts.

[0095] In some embodiments, the peeling solution does not include nonionic surfactants including polyoxyalkylene alkyl ether of polyoxyalkylene oxide addition; polyoxyalkylene styrene phenyl ether of polyoxyalkylene oxide addition; polyol; ester compound of monovalent fatty acid; polyoxyalkylene alkyl phenyl ether of polyoxyalkylene oxide addition; polyoxyalkylene fatty acid ether of polyoxyalkylene oxide addition; polyoxyalkylene sorbitan fatty acid ester of polyoxyalkylene oxide addition; glycerin fatty acid ester; polyoxyalkylene castor oil of polyoxyalkylene oxide addition; polyoxyalkylene hydrogenated castor oil of polyoxyalkylene oxide addition; polyoxyalkylene sorbitol fatty acid ester of polyoxyalkylene oxide addition; polyglycerin fatty acid ester; alkyl glycerol ether; polyoxyalkylene cholesterol ether; alkyl glycoside; sucrose fatty acid ester; polyoxyethylene-polyoxypropylene block polymer; sorbitan fatty acid ester; and fatty acid alkanolamide.

[0096] In some embodiments, the stripping solution does not include amphoteric surfactants including 2-undecyl-N,N-(hydroxyethylcarboxymethyl)-2-imidazoline sodium salt, 2-coco-2-imidazoline hydroxide-1-carboxyethyloxy disodium salt; imidazoline-based amphoteric surfactants; 2- heptadecyl-N-carboxymethyl-N-hydroxyethyl imidazoline betaine, lauryl dimethylamino acetic acid betaine, alkyl betaines, amido betaines, sulfobetaines, and other betaine-based amphoteric surfactants; N-lauryl glycine, N-lauryl beta-alanine, N-stearyl beta-alanine, lauryl dimethylamino oxide, oleyl dimethylamino oxide, sodium lauryl glutamate, lauryl dimethylamino acetic acid betaine, stearyl dimethylamino acetic acid betaine, cocamidopropyl hydroxysultaine, and 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazoline betaine.

[0097] In some embodiments, the composite includes a metal substrate and a coating applied to one or both sides of the metal substrate.

[0098] In some embodiments, the coating includes a polymeric binder. The purpose of the polymeric binder in the coating is to provide adhesion between the coating and the metal substrate within the composite. In some embodiments, the polymeric binder includes an aqueous copolymer.

[0099] In some embodiments, the copolymer includes structural unit (a), wherein structural unit (a) is derived from a monomer selected from the group consisting of a carboxylic acid group-containing monomer, a carboxylic acid salt group-containing monomer, a sulfonic acid group-containing monomer, a sulfonic acid salt group-containing monomer, a phosphonic acid group-containing monomer, a phosphonic acid salt group-containing monomer, and combinations thereof. In some embodiments, the acid salt group is a salt of an acid group. In some embodiments, the acid salt group-containing monomer includes an alkali metal cation. Examples of alkali metals that form alkali metal cations include lithium, sodium, and potassium. In some embodiments, the acid salt group-containing monomer includes an ammonium cation. In some embodiments, structural unit (a) can include a combination of a salt group-containing monomer and a carboxylic acid group-containing monomer.

[0100] In some embodiments, the carboxylic acid group-containing monomer is acrylic acid, methacrylic acid, crotonic acid, 2-butyl crotonic acid, cinnamic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, 4,4-dimethyltetraconic acid, or a combination thereof. In certain embodiments, the carboxylic acid group-containing monomer is 2-ethylacrylic acid, isocrotonic acid, cis-2-pentenoic acid, trans-2-pentenoic acid, angelic acid, tiglic acid, 3,3-dimethylacrylic acid, 3-propylacrylic acid, trans-2-methyl-3-ethylacrylic acid, cis-2-methyl-3-ethylacrylic acid, 3-isopropylacrylic acid, trans-3-methyl-3-ethylacrylic acid, cis-3-methyl-3-ethylacrylic acid, 2-isopropylacrylic acid, trimethylacrylic acid, 2-methyl-3,3-diethylacrylic acid, 3-butylacrylic acid, 2-butylacrylic acid, 2-pentylacrylic acid, 2-methyl-2-hexenoic acid, trans-3-methyl-2-hexenoic acid, 3-methyl-3-propylacrylic acid, 2-ethyl-3-propylacrylic acid, 2,3-diethylacrylic acid, 3,3-diethylacrylic acid, 3-methyl-3-hexylacrylic acid, 3-methyl-3-tert-butylacrylic acid, 2-methyl-3-pentylacrylic acid, 3-methyl-3-pentylacrylic acid, 4-methyl-2-hexenoic acid, 4-ethyl-2-hexenoic acid, 3-methyl-2-ethyl-2-hexenoic acid, 3-tert-butylacrylic acid, 2,3-dimethyl-3-ethylacrylic acid, 3,3-dimethyl-2-ethylacrylic acid, 3-methyl-3-isopropylacrylic acid, 2-methyl-3-isopropylacrylic acid, trans-2-octenoic acid, cis-2-octenoic acid, trans-2-decenoic acid, α-acetoxyacrylic acid, γ-trans-aroyloxyacrylic acid, α-chloro-γ-E-methoxyacrylic acid, or a combination thereof. In some embodiments, the carboxylic acid group-containing monomer is methyl maleic acid, dimethyl maleic acid, phenyl maleic acid, bromomaleic acid, chloromaleic acid, dichloromaleic acid, fluoromaleic acid, difluoromaleic acid, nonyl hydrogen maleate, deeyl hydrogen maleate, dodecyl hydrogen maleate, stearyl hydrogen maleate, fluoroalkyl hydrogen maleate, or a combination thereof. In some embodiments, the carboxylic acid group-containing monomer is maleic anhydride, methyl maleic anhydride, dimethyl maleic anhydride, acrylic anhydride, methacrylic anhydride, methacrolein, methacryloyl chloride, methacryloyl fluoride, methacryloyl bromide, or a combination thereof.

[0101] In some embodiments, the carboxylate group-containing monomer is an acrylic acid salt, a methacrylic acid salt, a crotonic acid salt, a 2-butyl crotonic acid salt, a cinnamic acid salt, a maleic acid salt, a maleic anhydride salt, a fumaric acid salt, an itaconic acid salt, an itaconic anhydride salt, a 4,4-dimethyl itaconic acid salt, or a combination thereof. In certain embodiments, the carboxylate group-containing monomer is a 2-ethyl acrylic acid salt, an isocrotonic acid salt, a cis-2-pentenoic acid salt, a trans-2-pentenoic acid salt, an angelic acid salt, a tiglic acid salt, a 3,3-dimethyl acrylic acid salt, a 3-propyl acrylic acid salt, a trans-2-methyl-3-ethyl acrylic acid salt, a cis-2-methyl-3-ethyl acrylic acid salt, a 3-isopropyl acrylic acid salt, a trans-3-methyl-3-ethyl acrylic acid salt, a cis-3-methyl-3-ethyl acrylic acid salt, a 2-isopropyl acrylic acid salt, a trimethyl acrylic acid salt, a 2-methyl-3,3-diethyl acrylic acid salt, a 3-butyl acrylic acid salt, a 2-butyl acrylic acid salt, a 2-pentyl acrylic acid salt, a 2-methyl 2-hexenoic acid salt, a trans 3-methyl 2-hexenoic acid salt, a 3-methyl-3-propyl acrylic acid salt, a 2-ethyl-3-propyl acrylic acid salt, a 2,3-diethyl acrylic acid salt, a 3,3-diethyl acrylic acid salt, a 3-methyl-3-hexyl acrylic acid salt, a 3-methyl-3-tert-butyl acrylic acid salt, a 2-methyl-3-pentyl acrylic acid salt, a 3-methyl-3-pentyl acrylic acid salt, a 4-methyl-2-hexenoic acid salt, a 4-ethyl-2-hexenoic acid salt, a 3-methyl-2-ethyl-2-hexenoic acid salt, a 3-tert-butyl acrylic acid salt, a 2,3-dimethyl-3-ethyl acrylic acid salt, a 3,3-dimethyl-2-ethyl acrylic acid salt, a 3-methyl-3-isopropyl acrylic acid salt, a 2-methyl-3-isopropyl acrylic acid salt, a trans-2-octenoic acid salt, a cis-2-octenoic acid salt, a trans-2-decenoic acid salt, an α-acetoxy acrylic acid salt, a β-trans-aryloxy acrylic acid salt, an α-chloro-β-E-methoxy acrylic acid salt, or a combination thereof. In some embodiments, the carboxylate group-containing monomer is a methyl maleic acid salt, a dimethyl maleic acid salt, a phenyl maleic acid salt, a bromomaleic acid salt, a chloromaleic acid salt, a dichloromaleic acid salt, a fluoromaleic acid salt, a difluoromaleic acid salt, or a combination thereof.

[0102] In some embodiments, the sulfonic acid group-containing monomer is vinyl sulfonic acid, methyl vinyl sulfonic acid, allyl vinyl sulfonic acid, allyl sulfonic acid, methyl allyl sulfonic acid, styrene sulfonic acid, 2-sulfoethyl methacrylic acid, 2-methyl-2-propen-1-sulfonic acid, 2-acrylamido-2-methyl-1-propane sulfonic acid, 3-allyloxy-2-hydroxy-1-propane sulfonic acid, allyl hydrogen sulfate, ethylene hydrogen sulfate, or a combination thereof.

[0103] In some embodiments, the monomer containing the sulfonate group is vinyl sulfonate, methyl vinyl sulfonate, allyl vinyl sulfonate, allyl sulfonate, methyl allyl sulfonate, styrene sulfonate, 2-sulfoethyl methacrylate, 2-methyl-2-propene-1-sulfonate, 2-acrylamido-2-methyl-1-propane sulfonate, 3-allyloxy-2-hydroxy-1-propane sulfonate, allyl sulfate, vinyl sulfate, or combinations thereof.

[0104] In some embodiments, the monomer containing the phosphonic acid group is vinylphosphonic acid, allylphosphonic acid, vinylbenzylphosphonic acid, acrylamide alkylphosphonic acid, methacrylamide alkylphosphonic acid, acrylamide alkyl diphosphonic acid, acryloylphosphonic acid, 2-methacryloyloxyethylphosphonic acid, bis(2-methacryloyloxyethyl)phosphonic acid, ethylene-2-methacryloyloxyethylphosphonic acid, ethylmethacryloyloxyethylphosphonic acid, allyl hydrogen phosphate, ethylene hydrogen phosphate, or combinations thereof.

[0105] In some embodiments, the monomer containing the phosphonate group is vinyl phosphonate, allyl phosphonate, vinyl benzyl phosphonate, acrylamide alkyl phosphonate, methacrylamide alkyl phosphonate, acrylamide alkyl diphosphonate, acryloyl phosphonate, 2-methacryloyloxyethyl phosphonate, bis(2-methacryloyloxyethyl) phosphonate, ethylene 2-methacryloyloxyethyl phosphonate, ethyl-methacryloyloxyethyl phosphonate, allyl phosphate, vinyl phosphate, or a combination thereof.

[0106] In some embodiments, based on the total molar number of monomer units in the copolymer binder, the proportion of structural unit (a) in the copolymer is, on a molar basis, about 15% to about 80%, about 17.5% to about 80%, about 20% to about 80%, about 22.5% to about 80%, about 25% to about 80%, about 27.5% to about 80%, about 30% to about 80%, about 32.5% to about 80%, about 35% to about 80%, about 37.5% to about 80%, about 40% to about 80%, and about 42.5% to Approximately 80%, approximately 45% to approximately 80%, approximately 47.5% to approximately 80%, approximately 50% to approximately 80%, approximately 52.5% to approximately 80%, approximately 55% to approximately 80%, approximately 57.5% to approximately 80%, approximately 60% to approximately 80%, approximately 15% to approximately 75%, approximately 17.5% to approximately 75%, approximately 20% to approximately 75%, approximately 22.5% to approximately 75%, approximately 25% to approximately 75%, approximately 27.5% to approximately 75%, approximately 30% to approximately 75%, approximately 32.5% to approximately 75%, approximately 35% to approximately 75%, about 37.5% to about 75%, about 40% to about 75%, about 42.5% to about 75%, about 45% to about 75%, about 47.5% to about 75%, about 50% to about 75%, 52.5% to 75%, 55% to 75%, about 15% to about 70%, about 17.5% to about 70%, about 20% to about 70%, about 22.5% to about 70%, about 25% to about 70%, about 27.5% to about 70%, about 30% to about 70%, about 32.5% to about 70%. Approximately 35% to approximately 70%, approximately 37.5% to approximately 70%, approximately 40% to approximately 70%, approximately 42.5% to approximately 70%, approximately 45% to approximately 70%, approximately 47.5% to approximately 70%, approximately 50% to approximately 70%, approximately 20% to approximately 50%, approximately 22.5% to approximately 50%, approximately 25% to approximately 50%, approximately 27.5% to approximately 50%, approximately 30% to approximately 50%, approximately 32.5% to approximately 50%, approximately 35% to approximately 50%, approximately 37.5% to approximately 50%, or approximately 40% to approximately 50%.

[0107] In some embodiments, based on the total molar number of monomer units in the copolymer binder, the proportion of structural unit (a) in the copolymer is less than 80%, less than 77.5%, less than 75%, less than 72.5%, less than 70%, less than 67.5%, less than 65%, less than 62.5%, less than 60%, less than 57.5%, less than 55%, less than 52.5%, less than 50%, less than 47.5%, less than 45%, less than 42.5%, less than 40%, less than 37.5%, less than 35%, less than 32.5%, less than 30%, less than 27.5%, or less than 25% on a molar basis. In some embodiments, based on the total molar number of monomer units in the copolymer binder, the proportion of structural unit (a) in the copolymer is greater than 15%, greater than 17.5%, greater than 20%, greater than 22.5%, greater than 25%, greater than 27.5%, greater than 30%, greater than 32.5%, greater than 35%, greater than 37.5%, greater than 40%, greater than 42.5%, greater than 45%, greater than 47.5%, greater than 50%, greater than 55%, greater than 57.5%, greater than 60%, greater than 62.5%, greater than 65%, greater than 67.5%, or greater than 70% by molar weight.

[0108] In some embodiments, the copolymer further comprises structural unit (b) derived from monomers selected from the group consisting of monomers containing amide groups, monomers containing hydroxy groups, and combinations thereof.

[0109] In some embodiments, the monomer containing the amide group is acrylamide, methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N-n-propylmethacrylamide, N-isopropylmethacrylamide, isopropylacrylamide, N-n-butylmethacrylamide, N-isobutylmethacrylamide, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N,N-diethylacrylamide, N,N-diethylmethacrylamide, N-hydroxymethylmethacrylamide, N-(methoxymethyl)methacrylamide, N-(ethoxymethyl)methacrylamide, etc. Methacrylamide, N-(propoxymethyl)methacrylamide, N-(butoxymethyl)methacrylamide, N-(3-(dimethylamino)propyl)methacrylamide, N-(2-(dimethylamino)ethyl)methacrylamide, N,N-(dihydroxymethyl)methacrylamide, diacetone methacrylamide, diacetone acrylamide, methacryloylmorpholine, N-hydroxymethylacrylamide, N-methoxymethylacrylamide, N,N'-methylenebisacrylamide (MBA), N-hydroxymethylacrylamide or combinations thereof.

[0110] In some embodiments, the monomer containing a hydroxyl group is a monomer containing a hydroxyl group and containing C1 to C2. 20 alkyl groups or C5 to C6 groups20 Methacrylates with cycloalkyl groups. In some embodiments, the monomer containing the hydroxyl group is 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentyl acrylate, 6-hydroxyhexyl methacrylate, 1,4-cyclohexanediethanol mono(meth)acrylate, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol mono(meth)acrylate, allyl alcohol, or combinations thereof.

[0111] In some embodiments, based on the total molar number of monomer units in the copolymer binder, the proportion of structural unit (b) in the copolymer is approximately 5% to 35% by molar, approximately 7% to 35%, approximately 9% to 35%, approximately 11% to 35%, approximately 13% to 35%, approximately 15% to 35%, approximately 17% to 35%, approximately 19% to 35%, approximately 21% to 35%, approximately 23% to 35%, and approximately 25%. About 35%, about 5% to about 27%, about 7% to about 27%, about 9% to about 27%, about 11% to about 27%, about 13% to about 27%, about 15% to about 27%, about 17% to about 27%, about 19% to about 27%, about 21% to about 27%, about 5% to about 21%, about 7% to about 21%, about 9% to about 21%, about 11% to about 21%, about 13% to about 21%, or about 15% to about 21%.

[0112] In some embodiments, based on the total molar number of monomer units in the copolymer binder, the proportion of structural unit (b) in the copolymer is less than 35%, less than 33%, less than 31%, less than 29%, less than 27%, less than 25%, less than 23%, less than 21%, less than 19%, less than 17%, less than 15%, less than 13%, less than 11%, or less than 10% by molar. In some embodiments, based on the total molar number of monomer units in the copolymer binder, the proportion of structural unit (b) in the copolymer is more than 5%, more than 6%, more than 7%, more than 8%, more than 9%, more than 10%, more than 11%, more than 13%, more than 15%, more than 17%, more than 19%, more than 21%, more than 23%, or more than 25% by molar.

[0113] In some embodiments, the copolymer further comprises a structural unit (c) derived from monomers selected from the group consisting of monomers containing nitrile groups, monomers containing ester groups, monomers containing epoxy groups, fluorinated monomers, and combinations thereof.

[0114] In some embodiments, the monomer containing a nitrile group includes α,β-olefinically unsaturated nitrile monomers. In some embodiments, the monomer containing a nitrile group is acrylonitrile, α-haloacrylonitrile, α-alkylacrylonitrile, or a combination thereof. In some embodiments, the monomer containing a nitrile group is α-chloroacrylonitrile, α-bromoacrylonitrile, α-fluoroacrylonitrile, methacrylonitrile, α-ethylacrylonitrile, α-isopropylacrylonitrile, α-n-hexylacrylonitrile, α-methoxyacrylonitrile, 3-methoxyacrylonitrile, 3-ethoxyacrylonitrile, α-acetoxyacrylonitrile, α-phenylacrylonitrile, α-tolylacrylonitrile, α-(methoxyphenyl)acrylonitrile, α-(chlorophenyl)acrylonitrile, α-(cyanophenyl)acrylonitrile, vinylidene cyanide, or a combination thereof.

[0115] In some embodiments, the monomer containing the ester group is C1-C. 20 Alkyl acrylates, C1-C 20 Alkyl (meth)acrylates, cycloalkyl acrylates, or combinations thereof. In some embodiments, the monomers containing ester groups are methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, sec-butyl acrylate, tert-butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, 3,3,5-trimethylhexyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, lauryl acrylate, n-tetradecyl acrylate, octadecyl acrylate, cyclohexyl acrylate, phenyl acrylate, methoxymethyl acrylate, methoxyethyl acrylate, ethoxymethyl acrylate, ethoxyethyl acrylate, perfluorooctyl acrylate, stearate acrylate, or combinations thereof. In some embodiments, the monomers containing ester groups are cyclohexyl acrylate, cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate, 3,3,5-trimethylcyclohexyl acrylate, or combinations thereof. In some embodiments, the monomer containing the ester group is methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, isobutyl methacrylate, n-pentyl methacrylate, isopentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, lauryl methacrylate, n-tetradecyl methacrylate, stearate methacrylate, 2,2,2-trifluoroethyl methacrylate, phenyl methacrylate, benzyl methacrylate, or combinations thereof.

[0116] In some embodiments, the epoxy group-containing monomer is vinyl glycidyl ether, allyl glycidyl ether, allyl 2,3-epoxypropyl ether, butenyl glycidyl ether, butadiene monoepoxide, chloroprene monoepoxide, 3,4-epoxy-1-butene, 4,5-epoxy-2-pentene, 3,4-epoxy-1-vinylcyclohexane, 1,2-epoxy-4-vinylcyclohexane, 3,4-epoxycyclohexylethylene, epi-4-vinylcyclohexene, 1,2-epoxy-5,9-cyclododecadiene, or a combination thereof.

[0117] In some embodiments, the epoxy group-containing monomer is 3,4-epoxy-1-butene, 1,2-epoxy-5-hexene, 1,2-epoxy-9-decene, glycidyl acrylate, glycidyl methacrylate, glycidyl crotonate, 2,4-dimethylpentenoic acid glycidyl ester, 4-hexenoic acid glycidyl ester, 4-heptenoic acid glycidyl ester, 5-methyl-4-heptenoic acid glycidyl ester, sorbic acid glycidyl ester, linoleic acid glycidyl ester, oleic acid glycidyl ester, 3-butenoic acid glycidyl ester, 3-pentenoic acid glycidyl ester, 4-methyl-3-pentenoic acid glycidyl ester, or a combination thereof.

[0118] In some embodiments, the fluorinated monomer is C1-C. 20 Acrylates, methacrylates, or combinations thereof with alkyl groups, wherein the monomer contains at least one fluorine atom. In some embodiments, the fluorinated monomer is a perfluoroalkyl acrylate, such as perfluorododecyl acrylate, perfluoron-octyl acrylate, perfluoron-butyl acrylate, perfluorohexylethyl acrylate, and perfluorooctylethyl acrylate; a perfluoroalkyl methacrylate, such as perfluorododecyl methacrylate, perfluoron-octyl methacrylate, perfluoron-butyl methacrylate, perfluorohexylethyl methacrylate, and perfluorooctylethyl methacrylate; a perfluorooxyalkyl acrylate, such as perfluorododecoxyethyl acrylate and perfluorodecoxyethyl acrylate; a perfluorooxyalkyl methacrylate, such as perfluorododecoxyethyl methacrylate and perfluorodecoxyethyl methacrylate, or combinations thereof. In some embodiments, the fluorinated monomer contains at least one C1-C. 20 A carboxylate salt containing an alkyl group and at least one fluorine atom, wherein the carboxylate salt is selected from the group consisting of crotonate, malate, fumarate, itaconic acid, or combinations thereof. In some embodiments, the fluorinated monomer is vinyl fluoride, trifluoroethylene, trifluorochloroethylene, fluoroalkyl vinyl ether, perfluoroalkyl vinyl ether, hexafluoropropylene, 2,3,3,3-tetrafluoropropylene, vinylidene fluoride, tetrafluoroethylene, 2-fluoroacrylate, or combinations thereof.

[0119] In some embodiments, based on the total molar number of monomer units in the copolymer binder, the proportion of structural unit (c) in the copolymer is approximately 15% to approximately 75%, approximately 17.5% to approximately 75%, approximately 20% to approximately 75%, approximately 22.5% to approximately 75%, approximately 25% to approximately 75%, approximately 27.5% to approximately 75%, approximately 30% to approximately 75%, approximately 32.5% to approximately 75%, approximately 35% to approximately 75%, and approximately 3... 7.5% to about 75%, about 40% to about 75%, about 42.5% to about 75%, about 45% to about 75%, about 47.5% to about 75%, about 50% to about 75%, about 52.5% to about 75%, about 55% to about 75%, about 20% to about 70%, about 22.5% to about 70%, about 25% to about 70%, about 27.5% to about 70%, about 30% to about 70%, about 32.5% to about 7 0%, about 35% to about 70%, about 37.5% to about 70%, about 40% to about 70%, about 42.5% to about 70%, about 45% to about 70%, about 47.5% to about 70%, about 50% to about 70%, about 20% to about 60%, about 22.5% to about 60%, about 25% to about 60%, about 27.5% to about 60%, about 30% to about 60%, about 32.5% to about 60%, about 35% % to about 60%, about 37.5% to about 60%, about 40% to about 60%, about 42.5% to about 60%, about 45% to about 60%, about 20% to about 50%, about 22.5% to about 50%, about 25% to about 50%, about 27.5% to about 50%, about 30% to about 50%, about 32.5% to about 50%, about 35% to about 50%, about 37.5% to about 50%, or about 40% to about 50%.

[0120] In some embodiments, based on the total molar number of monomer units in the copolymer binder, the proportion of structural unit (c) in the copolymer is less than 75%, less than 72%, less than 70%, less than 67.5%, less than 65%, less than 62.5%, less than 60%, less than 57.5%, less than 55%, less than 52.5%, less than 50%, less than 47.5%, less than 45%, less than 42.5%, less than 40%, less than 37.5%, less than 35%, less than 32.5%, less than 30%, less than 27.5%, less than 25%, or less than 22.5% on a molar basis. In some embodiments, based on the total molar number of monomer units in the copolymer binder, the proportion of structural units (c) in the copolymer is greater than 15%, greater than 16%, greater than 17.5%, greater than 20%, greater than 22.5%, greater than 25%, greater than 27.5%, greater than 30%, greater than 32.5%, greater than 35%, greater than 37.5%, greater than 40%, greater than 42.5%, greater than 45%, greater than 47.5%, greater than 50%, greater than 52.5%, greater than 55%, greater than 57.5%, greater than 60%, greater than 62.5%, or greater than 65% on a molar basis.

[0121] In other embodiments, the copolymer also comprises structural units derived from olefins. Any hydrocarbon containing at least one carbon-carbon double bond can be used as an olefin without any particular limitations. In some embodiments, the olefin includes C2-C... 20 Aliphatic compounds, C8-C 20 Aromatic compounds or cyclic compounds containing vinyl unsaturated bonds, C4-C 40Dienes and combinations thereof. In some embodiments, the olefin is styrene, ethylene, propylene, isobutene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, cyclobutene, 3-methyl-1-pentene, 4-methyl-1-pentene, 4,6-dimethyl-1-heptene, 4-vinylcyclohexene, vinylcyclohexane, norbornene, norbornediene, ethylidene norbornene, cyclopentene, cyclohexene, dicyclopentadiene, cyclooctene, or combinations thereof. In some embodiments, the copolymer does not contain structural units derived from olefins. In some embodiments, the copolymer does not contain structural units derived from styrene, ethylene, propylene, isobutene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, cyclobutene, 3-methyl-1-pentene, 4-methyl-1-pentene, 4,6-dimethyl-1-heptene, 4-vinylcyclohexene, vinylcyclohexane, norbornene, norbornadiene, ethylidene norbornene, cyclopentene, cyclohexene, dicyclopentadiene, or cyclooctene.

[0122] Monomers containing conjugated diene groups belong to the olefin family. In some embodiments, monomers containing conjugated diene groups include C4-C4 monomers. 40 Dienes; aliphatic conjugated diene monomers, such as 1,3-butadiene, 1,3-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,7-octadiene, 1,9-decadiene, isoprene, myrcene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene; substituted linear conjugated pentadienes; substituted side-chain conjugated hexadienes or combinations thereof. In some embodiments, the copolymer does not contain C4-C derivatives. 40 Dienes; aliphatic conjugated diene monomers, such as 1,3-butadiene, 1,3-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,7-octadiene, 1,9-decadiene, isoprene, myrcene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene; substituted linear conjugated pentadiene or substituted side-chain conjugated hexadiene structural units.

[0123] In other embodiments, the copolymer further comprises structural units derived from monomers containing aromatic vinyl groups. In some embodiments, the monomers containing aromatic vinyl groups are styrene, α-methylstyrene, vinyltoluene, divinylbenzene, or combinations thereof. In some embodiments, the copolymer does not contain structural units derived from monomers containing aromatic vinyl groups. In some embodiments, the copolymer does not contain structural units derived from styrene, α-methylstyrene, vinyltoluene, or divinylbenzene.

[0124] In some embodiments, the metal substrate may be in the form of a foil, sheet, or film. In some embodiments, the metal substrate is selected from the group consisting of stainless steel, titanium, nickel, aluminum, copper, platinum, gold, silver, chromium, zirconium, tungsten, molybdenum, tin, vanadium, zinc, cadmium, iron, cobalt, lead, and their alloys. In some embodiments, the metal substrate may comprise two or more layers, wherein the material of each layer is selected from the group consisting of stainless steel, titanium, nickel, aluminum, copper, platinum, gold, silver, chromium, zirconium, tungsten, molybdenum, tin, vanadium, zinc, cadmium, iron, cobalt, lead, and their alloys. In some embodiments, the metal substrate has a double-layer structure. In some embodiments, the metal substrate has three or more layers. In some embodiments, the metal substrate has only one layer. In some embodiments, the material of each layer in the metal substrate is the same. In some embodiments, the material of each layer in the metal substrate is different or partially different.

[0125] In some embodiments, when the metal substrate comprises more than one layer, the metal substrate includes one layer of insulating material. In some embodiments, the insulating material is a polymeric material selected from the group consisting of polycarbonate, polyacrylate, polyacrylonitrile, polyester, polyamide, polystyrene, polyurethane, epoxy resin, poly(acrylonitrile butadiene styrene), polyimide, polyolefin, polyethylene, polypropylene, polyphenylene sulfide, poly(vinyl ester), polyvinyl chloride, polyether, polyphenylene ether, cellulose polymers, and combinations thereof. When the metal substrate includes one layer of insulating material, a coating is applied to the metal layer outside the substrate.

[0126] In some embodiments, the metal substrate is coated with a layer of carbonaceous material. This carbonaceous material is part of the coating. In some embodiments, the metal substrate is not coated with a layer of carbonaceous material.

[0127] When the composite is immersed in the stripping solution for insufficient time, the stripping agent and aqueous solvent in the solution may not have enough time to shake, interfere with, and break the bonds initially formed between the coating and the metal substrate surface to achieve complete stripping. However, when the composite is immersed in the stripping solution for an extended period, the prolonged contact time between the composite and the stripping agent (e.g., alkali metal phosphates) in the solution may cause corrosion of the metal substrate. There is no particular limitation on the stripping time, but it should be long enough to allow complete stripping to occur, yet short enough to prevent corrosion of the metal substrate.

[0128] In some embodiments, the immersion time of the complex in the stripping solution is approximately 1 second to approximately 120 minutes, approximately 5 seconds to approximately 120 minutes, approximately 10 seconds to approximately 120 minutes, approximately 20 seconds to approximately 120 minutes, approximately 30 seconds to approximately 120 minutes, approximately 45 seconds to approximately 120 minutes, approximately 60 seconds to approximately 120 minutes, approximately 75 seconds to approximately 120 minutes, approximately 90 seconds to approximately 120 minutes, approximately 105 seconds to approximately 120 minutes, approximately 120 seconds to approximately 120 minutes, approximately 30 seconds to approximately 90 minutes, approximately 30 seconds to approximately 75 minutes, approximately 30 seconds to approximately 60 minutes, approximately 30 seconds to approximately 45 minutes, approximately... 30 seconds to about 30 minutes, about 30 seconds to about 20 minutes, about 30 seconds to about 10 minutes, about 30 seconds to about 5 minutes, about 60 seconds to about 90 minutes, about 60 seconds to about 75 minutes, about 60 seconds to about 60 minutes, about 60 seconds to about 45 minutes, about 60 seconds to about 30 minutes, about 60 seconds to about 20 minutes, about 60 seconds to about 10 minutes, about 60 seconds to about 5 minutes, about 120 seconds to about 60 minutes, about 120 seconds to about 45 minutes, about 120 seconds to about 30 minutes, about 120 seconds to about 20 minutes, about 120 seconds to about 10 minutes, or about 120 seconds to about 5 minutes.

[0129] In some embodiments, the immersion time of the complex in the stripping solution is less than 120 minutes, less than 105 minutes, less than 90 minutes, less than 75 minutes, less than 60 minutes, less than 45 minutes, less than 30 minutes, less than 20 minutes, less than 10 minutes, less than 5 minutes, less than 1 minute, less than 45 seconds, less than 30 seconds, less than 20 seconds, or less than 10 seconds. In some embodiments, the immersion time of the complex in the stripping solution is more than 1 second, more than 5 seconds, more than 10 seconds, more than 20 seconds, more than 30 seconds, more than 45 seconds, more than 60 seconds, more than 75 seconds, more than 90 seconds, more than 105 seconds, more than 120 seconds, more than 5 minutes, more than 10 minutes, more than 20 minutes, or more than 30 minutes.

[0130] There are no special restrictions on the peeling temperature, but the temperature should not be too low so that it takes a long time to achieve complete peeling, nor should the temperature be too high so as to cause health and safety risks.

[0131] In some embodiments, the temperature at which the composite is immersed in the stripping solution is about 10°C to about 90°C, about 15°C to about 90°C, about 20°C to about 90°C, about 25°C to about 90°C, about 30°C to about 90°C, about 35°C to about 90°C, about 40°C to about 90°C, about 45°C to about 90°C, about 50°C to about 90°C, about 55°C to about 90°C, about 60°C to about 90°C, about 65°C to about 90°C, or about 70°C to about 90°C. ℃, about 75℃ to about 90℃, about 20℃ to about 75℃, about 25℃ to about 75℃, about 30℃ to about 75℃, about 35℃ to about 75℃, about 40℃ to about 75℃, about 45℃ to about 75℃, about 50℃ to about 75℃, about 55℃ to about 75℃, about 60℃ to about 75℃, about 25℃ to about 60℃, about 30℃ to about 60℃, about 35℃ to about 60℃, about 40℃ to about 60℃ or about 45℃ to about 60℃.

[0132] In some embodiments, the temperature at which the composite is immersed in the stripping solution is below 90°C, below 85°C, below 80°C, below 75°C, below 70°C, below 65°C, below 60°C, below 55°C, below 50°C, below 45°C, below 40°C, below 35°C, or below 30°C. In some embodiments, the temperature at which the composite is immersed in the stripping solution is above 10°C, above 15°C, above 20°C, above 25°C, above 30°C, above 35°C, above 40°C, above 45°C, above 50°C, above 55°C, above 60°C, above 65°C, or above 70°C.

[0133] When the amount of stripping solution used to immerse a given amount of the composite is insufficient, complete peeling of the composite will not occur. One example of this is finding that a significant portion of the coating remains adhered to or bonded to the surface of the metal substrate. While using excessive stripping solution does not have particular disadvantages in terms of peeling effectiveness, it wastes raw materials and can generate unnecessary water-based solvent waste, requiring further processing steps for solvent reuse. Therefore, there are no particular limitations on the ratio of composite to stripping solution, except that the ratio of stripping solution to composite should be sufficient to peel all the composite material. However, for cost reasons, using an excessively high ratio of stripping agent to composite is not recommended.

[0134] In some embodiments, when the composite is immersed in a stripping solution to achieve composite stripping, the weight ratio of the composite to the stripping solution is about 0.01% to about 50%, about 0.02% to about 50%, about 0.05% to about 50%, about 0.1% to about 50%, about 0.2% to about 50%, about 0.5% to about 50%, about 1% to about 50%, about 2% to about 50%, about 5% to about 50%, about 10% to about 50%, about 15% to about 50%, about 20% to about 50%, about 25% to about 50%, about 30% to about 50%, or about 0.01% to about 25%. About 0.02% to about 25%, about 0.05% to about 25%, about 0.1% to about 25%, about 0.2% to about 25%, about 0.5% to about 25%, about 1% to about 25%, about 2% to about 25%, about 5% to about 25%, about 10% to about 25%, about 0.1% to about 15%, about 0.2% to about 15%, about 0.5% to about 15%, about 1% to about 15%, about 2% to about 15%, about 5% to about 15%, about 0.1% to about 5%, about 0.2% to about 5%, about 0.5% to about 5%, about 1% to about 5%, or about 2% to about 5%.

[0135] In some embodiments, when the complex is immersed in a stripping solution to achieve stripping of the complex, the weight ratio of the complex to the stripping solution is less than 50%, less than 45%, less than 40%, less than 35%, less than 30%, less than 25%, less than 20%, less than 15%, less than 10%, less than 5%, less than 2%, less than 1%, less than 0.5%, less than 0.2%, less than 0.1%, or less than 0.05%. In some embodiments, when the complex is immersed in a stripping solution to achieve stripping of the complex, the weight ratio of the complex to the stripping solution is greater than 0.01%, greater than 0.02%, greater than 0.05%, greater than 0.1%, greater than 0.2%, greater than 0.5%, greater than 1%, greater than 2%, greater than 5%, greater than 10%, greater than 15%, greater than 20%, greater than 25%, greater than 30%, greater than 35%, or greater than 40%.

[0136] The purpose of a stripping agent is to interrupt and disrupt the ion-dipole and hydrogen-bonding interactions between the copolymer binder within the coating and the surface of the metal substrate. A sufficient concentration of stripping agent is required in the stripping solution to effectively disrupt the interaction between the coating and the metal substrate, thereby allowing the composite to peel off. Relatively low concentrations of stripping agent are sufficient to disrupt the interaction between the copolymer binder within the coating and the surface of the metal substrate. Immersing the composite with a low concentration of stripping agent reduces the likelihood of corrosion of the metal substrate and other potentially metallic components within the composite, and / or reduces side reactions that may result from using high concentrations of stripping agent.

[0137] In some embodiments, the concentration of the stripping agent in the stripping solution is about 0.01M to about 3M, about 0.015M to about 3M, about 0.02M to about 3M, about 0.025M to about 3M, about 0.05M to about 3M, about 0.075M to about 3M, about 0.1M to about 3M, about 0.2M to about 3M, about 0.3M to about 3M, about 0.4M to about 3M, about 0.6M to about 3M, about 0.8M to about 3M, about 1M to about 3M, about 1.2M to about 3M, about 1.4M to about 3M, about 1.6M to about 3M, about 1.8M to about 3M, about 2M to about 3M, about 0.01M to about 2M, about 0.015M to about 2M, about 0.02M to about 2M, about 0.025M to about 2M, about 0.05M to about 2M, about... 0.075M to about 2M, about 0.1M to about 2M, about 0.2M to about 2M, about 0.3M to about 2M, about 0.4M to about 2M, about 0.6M to about 2M, about 0.8M to about 2M, about 1M to about 2M, about 0.025M to about 1.6M, about 0.05M to about 1.6M, about 0.075M to about 1.6M, about 0.1M to about 1.6M, about 0.2M to about 1.6M, about 0.3M to about 1.6M, about 0.4M to about 1.6M, about 0.6M to about 1.6M, about 0.8M to about 1.6M, about 1M to about 1.6M, about 0.05M to about 1M, about 0.075M to about 1M, about 0.1M to about 1M, about 0.2M to about 1M, about 0.3M to about 1M, or about 0.4M to about 1M.

[0138] In some embodiments, the concentration of the stripping agent in the stripping solution is less than 3M, less than 2.8M, less than 2.6M, less than 2.4M, less than 2.2M, less than 2M, less than 1.8M, less than 1.6M, less than 1.4M, less than 1.2M, less than 1M, less than 0.8M, less than 0.6M, less than 0.4M, less than 0.3M, less than 0.2M, less than 0.1M, less than 0.075M, or less than 0.05M. In some embodiments, the concentration of the stripping agent in the stripping solution is greater than 0.01M, greater than 0.015M, greater than 0.02M, greater than 0.025M, greater than 0.05M, greater than 0.075M, greater than 0.1M, greater than 0.2M, greater than 0.3M, greater than 0.4M, greater than 0.6M, greater than 0.8M, greater than 1M, greater than 1.2M, greater than 1.4M, greater than 1.6M, greater than 1.8M, greater than 2M, or greater than 2.2M.

[0139] In some embodiments, the surface density of the coating is about 1 mg / cm³. 2 Approximately 50 mg / cm 2 Approximately 2.5 mg / cm 2 Approximately 50 mg / cm 2Approximately 5 mg / cm 2 Approximately 50 mg / cm 2 Approximately 7.5 mg / cm 2 Approximately 50 mg / cm 2 Approximately 10 mg / cm 2 Approximately 50 mg / cm 2 Approximately 12.5 mg / cm³ 2 Approximately 50 mg / cm 2 Approximately 15 mg / cm 2 Approximately 50 mg / cm 2 Approximately 17.5 mg / cm³ 2 Approximately 50 mg / cm 2 Approximately 20 mg / cm 2 Approximately 50 mg / cm 2 Approximately 25 mg / cm 2 Approximately 50 mg / cm 2 Approximately 30 mg / cm 2 Approximately 50 mg / cm 2 Approximately 1 mg / cm 2 Approximately 30 mg / cm 2 Approximately 2.5 mg / cm 2 Approximately 30 mg / cm 2 Approximately 5 mg / cm 2 Approximately 30 mg / cm 2 Approximately 7.5 mg / cm 2 Approximately 30 mg / cm 2 Approximately 10 mg / cm 2 Approximately 30 mg / cm 2 Approximately 12.5 mg / cm 2 Approximately 30 mg / cm 2 Approximately 15 mg / cm 2 Approximately 30 mg / cm 2 Approximately 17.5 mg / cm³ 2 Approximately 30 mg / cm 2 Approximately 20 mg / cm 2 Approximately 30 mg / cm 2 Approximately 1 mg / cm 2 Approximately 20 mg / cm 2 Approximately 2.5 mg / cm 2 Approximately 20 mg / cm 2 Approximately 5 mg / cm 2 Approximately 20 mg / cm 2 Approximately 7.5 mg / cm³ 2 Approximately 20 mg / cm 2 Approximately 10 mg / cm 2Approximately 20 mg / cm 2 Approximately 12.5 mg / cm 2 Approximately 20 mg / cm 2 Approximately 1 mg / cm 2 Approximately 15 mg / cm 2 Approximately 2.5 mg / cm 2 Approximately 15 mg / cm 2 Approximately 5 mg / cm 2 Approximately 15 mg / cm 2 Approximately 7.5 mg / cm³ 2 Approximately 15 mg / cm 2 or about 10mg / cm 2 Approximately 15 mg / cm 2 .

[0140] In some embodiments, the surface density of the coating is less than 50 mg / cm³. 2 Less than 45mg / cm 2 Less than 35mg / cm 2 Less than 30mg / cm 2 Less than 25mg / cm 2 Less than 20 mg / cm 2 Less than 17.5 mg / cm 2 Less than 15mg / cm 2 Less than 12.5 mg / cm 2 Less than 10 mg / cm 2 Less than 7.5 mg / cm 2 Less than 5mg / cm 2 or less than 2.5 mg / cm 2 In some embodiments, the surface density of the coating is greater than 1 mg / cm³. 2 Greater than 2.5 mg / cm 2 Greater than 5 mg / cm 2 >7.5 mg / cm 2 Greater than 10 mg / cm 2 >12.5 mg / cm 2 Greater than 15 mg / cm 2 >17.5 mg / cm 2 Greater than 20 mg / cm 2 Greater than 25 mg / cm 2 Greater than 30 mg / cm 2 Greater than 35 mg / cm 2 or greater than 40 mg / cm 2 .

[0141] In some embodiments, the density of the coating is about 0.5 g / cm³. 3 Approximately 7.5 g / cm³ 3 Approximately 1g / cm 3 Approximately 7.5 g / cm³ 3 Approximately 1.5g / cm 3 Approximately 7.5 g / cm³ 3 Approximately 2g / cm 3 Approximately 7.5 g / cm³ 3 Approximately 2.5g / cm 3 Approximately 7.5 g / cm³ 3 Approximately 3g / cm 3 Approximately 7.5 g / cm³ 3 Approximately 3.5g / cm 3 Approximately 7.5 g / cm³ 3 Approximately 4g / cm 3 Approximately 7.5 g / cm³ 3 Approximately 4.5g / cm 3 Approximately 7.5 g / cm³ 3 Approximately 5g / cm 3 Approximately 7.5 g / cm³ 3 Approximately 0.5 g / cm 3 Approximately 5g / cm 3 Approximately 1g / cm 3 Approximately 5g / cm 3 Approximately 1.5g / cm 3 Approximately 5g / cm 3 Approximately 2g / cm 3 Approximately 5g / cm 3 Approximately 2.5g / cm 3 Approximately 5g / cm 3 Approximately 3g / cm 3 Approximately 5g / cm 3 Approximately 0.5 g / cm 3 Approximately 2.5 g / cm³ 3 Approximately 1g / cm 3 Approximately 2.5 g / cm³ 3 or approximately 1.5 g / cm 3 Approximately 2.5 g / cm³ 3 .

[0142] In some embodiments, the coating density is less than 7.5 g / cm³. 3 Less than 7g / cm 3 Less than 6.5 g / cm 3 Less than 6g / cm 3 Less than 5.5 g / cm 3 Less than 5g / cm 3Less than 4.5 g / cm 3 Less than 4g / cm 3 Less than 3.5g / cm 3 Less than 3g / cm 3 Less than 2.5 g / cm 3 Less than 2g / cm 3 or less than 1.5 g / cm³ 3 In some embodiments, the coating density is greater than 0.5 g / cm³. 3 Greater than 1g / cm 3 Greater than 1.5 g / cm 3 Greater than 2g / cm 3 Greater than 2.5 g / cm 3 Greater than 3g / cm 3 Greater than 3.5 g / cm 3 Greater than 4g / cm 3 Greater than 4.5 g / cm 3 Greater than 5g / cm 3 Greater than 5.5 g / cm 3 Greater than 6g / cm 3 or greater than 6.5 g / cm 3 .

[0143] In some embodiments, the complex-stripping solution mixture may be agitated to achieve complex stripping when the complex is immersed in the stripping solution. In some embodiments, a planetary mixer, a stirred mixer, a mixer, an ultrasonic generator, or a combination thereof is used to agitate the complex-stripping solution mixture. In other embodiments, the complex-stripping solution mixture is not agitated when the complex is immersed in the stripping solution.

[0144] In some embodiments, the stirring speed of the complex-exfoliation solution mixture is approximately 10 rpm to approximately 3000 rpm, approximately 20 rpm to approximately 3000 rpm, approximately 50 rpm to approximately 3000 rpm, approximately 100 rpm to approximately 3000 rpm, approximately 200 rpm to approximately 3000 rpm, approximately 250 rpm to approximately 3000 rpm, approximately 300 rpm to approximately 3000 rpm, approximately 400 rpm to approximately 3000 rpm, approximately 500 rpm to approximately 3000 rpm, approximately 600 rpm to approximately 3000 rpm, approximately 750 rpm to approximately 3000 rpm, approximately 900 rpm to approximately 3000 rpm, approximately 1200 rpm to approximately 3000 rpm, approximately 1500 rpm to approximately 3000 rpm, approximately 10 rpm to approximately 1000 rpm, approximately 20 rpm to approximately 1000 rpm, and approximately 50 rpm. Approximately 100 rpm to 1000 rpm, approximately 200 rpm to 1000 rpm, approximately 250 rpm to 1000 rpm, approximately 300 rpm to 1000 rpm, approximately 400 rpm to 1000 rpm, approximately 500 rpm to 1000 rpm, approximately 10 rpm to 750 rpm, approximately 20 rpm to 750 rpm, approximately 50 rpm to 750 rpm, approximately 100 rpm to 750 rpm, approximately 200 rpm to 750 rpm, approximately 250 rpm to 750 rpm, approximately 300 rpm to 750 rpm, approximately 10 rpm to 500 rpm, approximately 20 rpm to 500 rpm, approximately 50 rpm to 500 rpm, approximately 100 rpm to 500 rpm, or approximately 200 rpm to 500 rpm.

[0145] In some embodiments, the stirring speed of the complex-exfoliation solution mixture is less than 3000 rpm, less than 2500 rpm, less than 1500 rpm, less than 1200 rpm, less than 900 rpm, less than 750 rpm, less than 600 rpm, less than 500 rpm, less than 400 rpm, less than 300 rpm, or less than 250 rpm. In some embodiments, the stirring speed of the complex-exfoliation solution mixture is greater than 10 rpm, greater than 20 rpm, greater than 50 rpm, greater than 100 rpm, greater than 200 rpm, greater than 250 rpm, greater than 300 rpm, greater than 400 rpm, greater than 500 rpm, greater than 600 rpm, or greater than 750 rpm.

[0146] In some embodiments, the stirring time of the complex-exfoliation solution mixture is from about 1 second to about 120 minutes, from about 5 seconds to about 120 minutes, from about 10 seconds to about 120 minutes, from about 20 seconds to about 120 minutes, from about 30 seconds to about 120 minutes, from about 45 seconds to about 120 minutes, from about 60 seconds to about 120 minutes, from about 75 seconds to about 120 minutes, from about 90 seconds to about 120 minutes, from about 105 seconds to about 120 minutes, from about 120 seconds to about 120 minutes, from about 30 seconds to about 90 minutes, from about 30 seconds to about 75 minutes, from about 30 seconds to about 60 minutes, and from about 30 seconds to about 45 minutes. Approximately 30 seconds to approximately 30 minutes, approximately 30 seconds to approximately 20 minutes, approximately 30 seconds to approximately 10 minutes, approximately 30 seconds to approximately 5 minutes, approximately 60 seconds to approximately 90 minutes, approximately 60 seconds to approximately 75 minutes, approximately 60 seconds to approximately 60 minutes, approximately 60 seconds to approximately 45 minutes, approximately 60 seconds to approximately 30 minutes, approximately 60 seconds to approximately 20 minutes, approximately 60 seconds to approximately 10 minutes, approximately 60 seconds to approximately 5 minutes, approximately 120 seconds to approximately 60 minutes, approximately 120 seconds to approximately 45 minutes, approximately 120 seconds to approximately 30 minutes, approximately 120 seconds to approximately 20 minutes, approximately 120 seconds to approximately 10 minutes, or approximately 120 seconds to approximately 5 minutes.

[0147] In some embodiments, the stirring time of the complex-exfoliation solution mixture is less than 120 minutes, less than 105 minutes, less than 90 minutes, less than 75 minutes, less than 60 minutes, less than 45 minutes, less than 30 minutes, less than 20 minutes, less than 10 minutes, less than 5 minutes, less than 1 minute, less than 45 seconds, less than 30 seconds, less than 20 seconds, or less than 10 seconds. In some embodiments, the stirring time of the complex-exfoliation solution mixture is more than 1 second, more than 5 seconds, more than 10 seconds, more than 20 seconds, more than 30 seconds, more than 45 seconds, more than 60 seconds, more than 75 seconds, more than 90 seconds, more than 105 seconds, more than 120 seconds, more than 5 minutes, more than 10 minutes, more than 20 minutes, or more than 30 minutes.

[0148] In some embodiments, the planetary mixer includes at least one planetary impeller and at least one high-speed dispersing impeller. In some embodiments, the planetary impeller rotates at a speed of about 20 rpm to about 200 rpm, about 20 rpm to about 150 rpm, about 30 rpm to about 150 rpm, or about 50 rpm to about 100 rpm. In some embodiments, the dispersing impeller rotates at a speed of about 1000 rpm to about 4000 rpm, about 1000 rpm to about 3500 rpm, about 1000 rpm to about 3000 rpm, about 1000 rpm to about 2000 rpm, about 1500 rpm to about 3000 rpm, or about 1500 rpm to about 2500 rpm.

[0149] In some embodiments, the ultrasound generator is an ultrasound bath, a probe-type ultrasound generator, or an ultrasound flow cell. In some embodiments, the power density of the ultrasound generator during operation is about 10 W / L to about 100 W / L, about 20 W / L to about 100 W / L, about 30 W / L to about 100 W / L, about 40 W / L to about 80 W / L, about 40 W / L to about 70 W / L, about 40 W / L to about 60 W / L, about 40 W / L to about 50 W / L, about 50 W / L to about 60 W / L, about 20 W / L to about 80 W / L, about 20 W / L to about 60 W / L, or about 20 W / L to about 40 W / L. In some implementations, the power density of the ultrasonic generator during operation is greater than 10 W / L, greater than 20 W / L, greater than 30 W / L, greater than 40 W / L, greater than 50 W / L, greater than 60 W / L, greater than 70 W / L, greater than 80 W / L, or greater than 90 W / L.

[0150] In some embodiments, the ultrasonic generator operates at a power of about 100W to about 1000W, about 200W to about 1000W, about 300W to about 1000W, about 400W to about 1000W, about 500W to about 1000W, about 500W to about 900W, about 500W to about 800W, about 500W to about 700W, or about 500W to about 600W. In some embodiments, the ultrasonic generator operates at a power of less than 1000W, less than 900W, less than 800W, less than 700W, less than 600W, less than 500W, less than 400W, or less than 300W. In some embodiments, the ultrasonic generator operates at a power greater than 100W, greater than 200W, greater than 300W, greater than 400W, greater than 500W, greater than 600W, greater than 700W, or greater than 800W.

[0151] In some embodiments, after the complex is immersed in the stripping solution, the pH of the stripped complex-stripping solution mixture is about 9 to about 13, about 9.25 to about 13, about 9.5 to about 13, about 9.75 to about 13, about 10 to about 13, about 10.25 to about 13, about 10.5 to about 13, about 10.5 to about 12.75, about 10.5 to about 12.5, about 10.5 to about 12.25, about 10.5 to about 12, about 10.5 to about 11.75, or about 10.5 to about 11.5.

[0152] In some embodiments, after immersing the complex in the stripping solution, the pH value of the resulting complex-stripping solution mixture is less than 13, less than 12.75, less than 12.5, less than 12.25, less than 12, less than 11.75, less than 11.5, less than 11.25, less than 11, less than 10.75, less than 10.5, less than 10.25, less than 10, less than 9.75, or less than 9.5. In some embodiments, after immersing the complex in the stripping solution, the pH value of the resulting complex-stripping solution mixture is greater than 9, greater than 9.25, greater than 9.5, greater than 9.75, greater than 10, greater than 10.25, greater than 10.5, greater than 10.75, greater than 11, greater than 11.25, greater than 11.5, greater than 11.75, greater than 12, greater than 12.25, or greater than 12.5.

[0153] In some embodiments, after immersing the composite in a stripping solution, the composite is stripped into two or more layers. In some embodiments, after immersing the composite in a stripping solution, the composite is stripped into a coating and a metal substrate layer.

[0154] In some embodiments, the stripped composite-stripping solution mixture is screened to separate the coating and metal substrate from the stripping solution. In some embodiments, filtration, sieving, decantation, or a combination thereof may be used to screen the stripped composite-stripping solution mixture.

[0155] Figure 3 This is a flowchart of an implementation method illustrating the steps in method 300 for stripping the composite disclosed herein and extracting the coating and metal substrate materials for subsequent further processes. Because the metal substrate in this invention has a relatively low tendency to corrode and dissolve, the extracted stripping solution does not need to be purified and can be further reused. The extracted stripping solution can be reused for stripping other composites. This forms a closed-loop recycling process in which materials can be repeatedly recycled and reused and continuously participate in the cycle, contributing to the creation of a circular economy.

[0156] In some embodiments, the recovered stripped composite material may be subjected to additional separation and / or extraction processes to further extract the materials contained therein. In some embodiments, the recovered coating and metal substrate may be subjected to additional separation and / or extraction processes to further extract the coating and metal substrate materials.

[0157] The method of the present invention is particularly suitable for stripping electrodes in batteries, wherein the electrodes are composites, and the electrode layer and the current collector are respectively a coating and a metal substrate.

[0158] In some embodiments, the battery can be a primary battery or a secondary battery. Some non-limiting examples of batteries include alkaline batteries, aluminum-air batteries, lithium batteries, lithium-air batteries, magnesium batteries, solid-state batteries, silver oxide batteries, zinc-air batteries, aluminum-ion batteries, lead-acid batteries, lithium-ion batteries, magnesium-ion batteries, potassium-ion batteries, sodium-ion batteries, sodium-air batteries, silicon-air batteries, zinc-ion batteries, and sodium-sulfur batteries.

[0159] Within the electrode, a binder can be used to adhere the active material particles and conductive agent to the current collector to form a continuous conductive path. The copolymer binder disclosed herein exhibits excellent adhesion capabilities and can therefore be used. Due to its good adhesion between electrode layer components and between the electrode layer and the current collector, the use of this copolymer binder helps reduce the impedance and interfacial resistance between the current collector and the electrode material, thereby improving ion and electron transport rates. Furthermore, the disclosed copolymer readily interacts with water through hydrogen bonding and ion-dipole interactions, resulting in excellent dispersibility and stability of the copolymer binder in water, and good processability during electrode layer formation through the use of water-based slurries.

[0160] There are drawbacks to using current methods to peel the electrode layer from the current collector when recycling batteries. For example, calcination requires high temperatures and releases harmful substances, while leaching requires the use of hazardous and harmful chemicals.

[0161] Conversely, the stripping method disclosed herein allows for the efficient stripping of electrodes comprising a current collector and an electrode layer coated on one or both sides of the current collector (wherein the electrode layer comprises the copolymer binder disclosed herein) using a simple stripping solution, without significant safety concerns or environmental impact. Furthermore, the stripping process is highly efficient.

[0162] Figure 4a The cathode layer and current collector recovered after immersing the double-coated cathode in a stripping solution as shown in Example 2 are illustrated. The stripping solution contains 0.05 M tripotassium phosphate and deionized water. The double-coated cathode contains a copolymer binder, wherein, based on the total molar number of monomer units in the copolymer binder, structural unit (a) accounts for 49.45% by molar, structural unit (b) accounts for 26.48% by molar, and structural unit (c) accounts for 24.07% by molar. Similarly, Figure 4bThe image shows the recovered cathode layer and current collector after immersing a double-coated cathode in a stripping solution in Example 14. The stripping solution contains 0.25 M tripotassium phosphate and deionized water. The double-coated cathode contains a copolymer binder, wherein, based on the total molar number of monomer units in the copolymer binder, structural unit (a) accounts for 23.01% by molar, structural unit (b) accounts for 10.00% by molar, and structural unit (c) accounts for 66.99% by molar. Both figures show complete stripping of the cathode layer from the aluminum current collector, and no discoloration or pitting of the aluminum current collector is observed, indicating no significant corrosion of the aluminum current collector.

[0163] Figure 5 The cathode recovered in Comparative Example 1 is described, wherein the double-coated cathode immersed in the stripping solution contains polyvinylidene fluoride (PVDF) as a polymer binder. The stripping solution used herein contains 1M tripotassium phosphate and deionized water. It is evident that stripping the cathode layer from the aluminum current collector is unsuccessful; despite immersion in the stripping solution, the cathode layer remains firmly adhered to the aluminum current collector. This indicates that using the stripping agent disclosed in this invention for electrode stripping is not suitable for electrodes containing non-aqueous polymer binders (e.g., PVDF).

[0164] A current collector is used to collect electrons generated by the electrochemical reaction of a cathode active material or to provide electrons required for the electrochemical reaction. In some embodiments, the current collector may be in the form of a foil, sheet, or film. In some embodiments, the current collector is a metal. In some embodiments, the current collector is selected from the group consisting of stainless steel, titanium, nickel, aluminum, copper, platinum, gold, silver, chromium, zirconium, tungsten, molybdenum, tin, vanadium, zinc, cadmium, iron, cobalt, lead, and their alloys. In some embodiments, the current collector has only one layer. In some embodiments, the current collector has a two-layer structure. In some embodiments, the current collector has three or more layers. In some embodiments, one or more materials in each layer may be the same, different, or partially different.

[0165] In some embodiments, when the current collector comprises more than one layer, the current collector includes an insulating material layer. In some embodiments, the insulating material is a polymeric material selected from the group consisting of polycarbonate, polyacrylate, polyacrylonitrile, polyester, polyamide, polystyrene, polyurethane, epoxy resin, poly(acrylonitrile butadiene styrene), polyimide, polyolefin, polyethylene, polypropylene, polyphenylene sulfide, poly(vinyl ester), polyvinyl chloride, polyether, polyphenylene ether, cellulose polymers, and combinations thereof. When the current collector includes an insulating material layer, the coating is applied to a metal layer on the outer side of the current collector.

[0166] In some embodiments, the current collector is coated with a layer of carbonaceous material. This carbonaceous material is part of the coating. In some embodiments, the current collector is not coated with a layer of carbonaceous material.

[0167] The thickness of the current collector affects its volume in the battery, the amount of electrode active material required, and thus the battery capacity. In some embodiments, the thickness of the current collector is about 5 μm to about 50 μm, about 10 μm to about 50 μm, about 15 μm to about 50 μm, about 20 μm to about 50 μm, about 25 μm to about 50 μm, about 5 μm to about 30 μm, about 10 μm to about 30 μm, about 15 μm to about 30 μm, about 20 μm to about 30 μm, about 5 μm to about 20 μm, about 5 μm to about 15 μm, about 10 μm to about 30 μm, about 10 μm to about 25 μm, or about 10 μm to about 20 μm.

[0168] In some embodiments, the thickness of the current collector is less than 50 μm, less than 45 μm, less than 40 μm, less than 35 μm, less than 30 μm, less than 25 μm, less than 20 μm, less than 15 μm, or less than 10 μm. In some embodiments, the thickness of the current collector is greater than 5 μm, greater than 10 μm, greater than 15 μm, greater than 20 μm, greater than 25 μm, greater than 30 μm, greater than 35 μm, greater than 40 μm, or greater than 45 μm.

[0169] In some embodiments, the electrode may be a cathode or an anode. In some embodiments, the electrode layer further comprises an electrode active material.

[0170] In some embodiments, the electrode active material is a cathode active material, wherein the cathode active material is selected from LiCoO2, LiNiO2, and LiNi. x Mn y O2, LiCo x Ni y O2, Li 1+z Ni x Mn y Co 1-x-y O2, LiNi x Co y Al zThe group consisting of O2, LiV2O5, LiTiS2, LiMoS2, LiMnO2, LiCrO2, LiMn2O4, Li2MnO3, LiFeO2, LiFePO4 and combinations thereof, wherein each x is independently 0.1 to 0.9; each y is independently 0 to 0.9; and each z is independently 0 to 0.4. In some embodiments, each x in the above general formula is independently selected from 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875, and 0.9; each y in the above general formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, 0. 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775 0.8, 0.825, 0.85, 0.875, and 0.9; each z in the above general formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, and 0.4. In some embodiments, each x, y, and z in the above general formula independently has an interval of 0.01.

[0171] In some embodiments, the cathode active material is selected from LiCoO2, LiNiO2, and LiNi x Mn y O2, Li 1+ z Ni x Mn y Co 1-x-y O2(NMC), LiNi x Co y Al z O2, LiV2O5, LiTiS2, LiMoS2, LiMnO2, LiCrO2, LiMn2O4, LiFeO2, LiFePO4, LiCo x Ni yThe group consisting of O2 and combinations thereof, wherein each x is independently 0.4 to 0.6; each y is independently 0.2 to 0.4; and each z is independently 0 to 0.1. In other embodiments, the cathode active material is not LiCoO2, LiNiO2, LiV2O5, LiTiS2, LiMoS2, LiMnO2, LiCrO2, LiMn2O4, LiFeO2, or LiFePO4. In a further embodiment, the cathode active material is not LiNi x Mn y O2, Li 1+z Ni x Mn y Co 1-x-y O2, LiNi x Co y Al z O2 or LiCo x Ni y O2, wherein each x is independently 0.1 to 0.9; each y is independently 0 to 0.45; and each z is independently 0 to 0.2. In some embodiments, the cathode active material is Li. 1+x Ni a Mn b Co c Al (1 - a-b-c) O2; where -0.2≤x≤0.2, 0≤a<1, 0≤b<1, 0≤c<1, and a+b+c≤1. In some embodiments, the cathode active material has the general formula Li 1+ x Ni a Mn b Co c Al (1-a-b-c)O2, where 0.33≤a≤0.92, 0.33≤a≤0.9, 0.33≤a≤0.8, 0.4≤a≤0.92, 0.4≤a≤0.9, 0.4≤a≤0.8, 0.5≤a≤0.92, 0.5≤a≤0.9, 0.5≤a≤0.8, 0.6≤a≤0.92 or 0.6≤a≤0.9; 0≤b≤0.5, 0≤b≤0.4, 0≤b≤0.3, 0≤b≤0.2, 0.1≤b ≤0.5, 0.1≤b≤0.4, 0.1≤b≤0.3, 0.1≤b≤0.2, 0.2≤b≤0.5, 0.2≤b≤0.4 or 0.2≤b≤0.3; 0≤c≤0.5, 0≤c≤0.4, 0≤c≤0.3, 0.1≤c≤0.5, 0.1≤c≤0.4, 0.1≤c≤0.3, 0.1≤c≤0.2, 0.2≤c≤0.5, 0.2≤c≤0.4 or 0.2≤c≤0.3. In some embodiments, the cathode active material has the general formula LiMPO4, wherein M is selected from the group consisting of Fe, Co, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, Si, Ge and combinations thereof. In some embodiments, the cathode active material is selected from LiFePO4, LiCoPO4, LiNiPO4, LiMnPO4, LiMnFePO4, and LiMn. x Fe (1-x) The group consisting of PO4 and its combinations; where 0 < x < 1. In some embodiments, the cathode active material is LiNi. x Mn y O4; where 0.1 ≤ x ≤ 0.9 and 0 ≤ y ≤ 2. In some embodiments, the cathode active material is xLi2MnO3·(1-x)LiMO2, where M is selected from the group consisting of Ni, Co, Mn and combinations thereof; where 0 < x < 1. In some embodiments, the cathode active material is Li3V2(PO4)3 or LiVPO4F. In some embodiments, the cathode active material has the general formula Li2MSiO4, where M is selected from the group consisting of Fe, Co, Mn, Ni and combinations thereof.

[0172] In some embodiments, the cathode active material is doped with a dopant selected from the group consisting of Co, Cr, V, Mo, Nb, Pd, F, Na, Fe, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, Si, Ge, and combinations thereof. In some embodiments, the dopant is not Co, Cr, V, Mo, Nb, Pd, F, Na, Fe, Ni, Mn, Mg, Zn, Ti, La, Ce, Ru, Si, or Ge. In some embodiments, the dopant is not Al, Sn, or Zr.

[0173] In some embodiments, the cathode active material is LiNi. 0.33 Mn 0.33 Co 0.33 O2(NMC333), LiNi 0.4 Mn 0.4 Co 0.2 O2, LiNi 0.5 Mn 0.3 Co 0.2 O2(NMC532), LiNi 0.6 Mn 0.2 Co 0.2 O2(NMC622), LiNi 0.7 Mn 0.15 Co 0.15 O2, LiNi 0.7 Mn 0.1 Co 0.2 O2, LiNi 0.8 Mn 0.1 Co 0.1 O2(NMC811), LiNi 0.92 Mn 0.04 Co 0.04 O2, LiNi 0.8 Co 0.15 Al 0.05 O2 (NCA), LiNiO2 (LNO), or a combination thereof.

[0174] In other embodiments, the cathode active material is not LiCoO2, LiNiO2, LiMnO2, LiMn2O4, or Li2MnO3. In a further embodiment, the cathode active material is not LiNiO2. 0.33 Mn 0.33 Co 0.33 O2, LiNi 0.4 Mn 0.4 Co 0.2 O2, LiNi 0.5 Mn 0.3 Co 0.2 O2, LiNi 0.6 Mn 0.2 Co 0.2 O2, LiNi 0.7 Mn 0.15 Co 0.15 O2, LiNi 0.7 Mn 0.1 Co 0.2 O2, LiNi 0.8 Mn 0.1 Co 0.1 O2, LiNi 0.92 Mn 0.04Co 0.04 O2 or LiNi 0.8 Co 0.15 Al 0.05 O2.

[0175] In some embodiments, the cathode active material comprises, or is itself, a core-shell composite material having a core-shell structure, wherein the core and shell each independently comprise, selected from Li 1+x Ni a Mn b Co c Al (1-a-b-c) O2, LiCoO2, LiNiO2, LiMnO2, LiMn2O4, Li2MnO3, LiCrO2, Li4Ti5O 12 , LiV2O5, LiTiS2, LiMoS2, LiCo a Ni b O2, LiMn a Ni bLithium transition metal oxides comprising the group consisting of O2 and combinations thereof, wherein -0.2 ≤ x ≤ 0.2, 0 ≤ a < 1, 0 ≤ b < 1, 0 ≤ c < 1, and a + b + c ≤ 1. In some embodiments, each x in the above general formula is independently selected from -0.2, -0.175, -0.15, -0.125, -0.1, -0.075, -0.05, -0.025, 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, and 0.2; each a in the above general formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, and 0.3. 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875, 0.9, 0.925, 0.95, and 0.975; each b in the above formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.17 5, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875, 0.9, 0.925, 0.95, and 0.975; each c in the above formula is independently selected from 0, 0.025, 0.05 The values ​​are 0.075, 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875, 0.9, 0.925, 0.95, and 0.975. In some embodiments, each x, a, b, and c in the above formulas independently has a spacing of 0.01. In other embodiments, the core and shell each independently comprise two or more lithium transition metal oxides. In some embodiments, one of the core or shell contains only one lithium transition metal oxide, while the other contains two or more lithium transition metal oxides. The lithium transition metal oxides in the core and shell may be the same or different or partially different.In some embodiments, two or more lithium transition metal oxides are uniformly distributed on the core. In some embodiments, the two or more lithium transition metal oxides are not uniformly distributed on the core. In some embodiments, the cathode active material is not a core-shell composite material.

[0176] In some embodiments, each of the lithium transition metal oxides in the core and shell is independently doped with a dopant selected from the group consisting of Co, Cr, V, Mo, Nb, Pd, F, Na, Fe, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, Si, Ge, and combinations thereof. In some embodiments, the core and shell each independently contain two or more doped lithium transition metal oxides. In some embodiments, the two or more doped lithium transition metal oxides are uniformly distributed on the core and / or shell. In some embodiments, the two or more doped lithium transition metal oxides are non-uniformly distributed on the core and / or shell.

[0177] In some embodiments, the cathode active material comprises, or is itself, a core-shell composite material comprising a core containing a lithium transition metal oxide and a shell containing a transition metal oxide. In some embodiments, the lithium transition metal oxide is selected from Li... 1+x Ni a Mn b Co c Al (1-a-b-c) O2, LiCoO2, LiNiO2, LiMnO2, LiMn2O4, Li2MnO3, LiCrO2, Li4Ti5O 12 , LiV2O5, LiTiS2, LiMoS2, LiCo a Ni b O2, LiMn a Ni bThe group consisting of O2 and its combinations; wherein -0.2≤x≤0.2, 0≤a<1, 0≤b<1, 0≤c<1, and a+b+c≤1. In some embodiments, x in the above general formula is independently selected from 0.2, 0.175, 0.15, 0.125, 0.1, 0.075, -0.05, -0.025, 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, and 0.2; each a in the above general formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3, and 0.325. , 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875, 0.9, 0.925, 0.95, and 0.975; each b in the above formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, 0. 2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875, 0.9, 0.925, 0.95, and 0.975; each c in the above formula is independently selected from 0, 0.025, 0.05, 0. 0.075, 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875, 0.9, 0.925, 0.95, and 0.975. In some embodiments, each x, a, b, and c in the above general formula independently has an interval of 0.01. In some embodiments, the transition metal oxide is selected from the group consisting of Fe2O3, MnO2, Al2O3, MgO, ZnO, TiO2, La2O3, CeO2, SnO2, ZrO2, RuO2, and combinations thereof. In some embodiments, the shell comprises a lithium transition metal oxide and a transition metal oxide.

[0178] In some embodiments, the diameter of the core is about 1 μm to about 15 μm, about 3 μm to about 15 μm, about 3 μm to about 10 μm, about 5 μm to about 10 μm, about 5 μm to about 45 μm, about 5 μm to about 35 μm, about 5 μm to about 25 μm, about 10 μm to about 45 μm, about 10 μm to about 40 μm, about 10 μm to about 35 μm, about 10 μm to about 25 μm, about 15 μm to about 45 μm, about 15 μm to about 30 μm, about 15 μm to about 25 μm, about 20 μm to about 35 μm, or about 20 μm to about 30 μm. In some embodiments, the shell thickness is about 1 μm to about 45 μm, about 1 μm to about 35 μm, about 1 μm to about 25 μm, about 1 μm to about 15 μm, about 1 μm to about 10 μm, about 1 μm to about 5 μm, about 3 μm to about 15 μm, about 3 μm to about 10 μm, about 5 μm to about 10 μm, about 10 μm to about 35 μm, about 10 μm to about 20 μm, about 15 μm to about 30 μm, about 15 μm to about 25 μm, or about 20 μm to about 35 μm. In some embodiments, the diameter or thickness ratio of the core to the shell is in the range of 15:85 to 85:15, 25:75 to 75:25, 30:70 to 70:30, or 40:60 to 60:40. In some implementations, the volume or weight ratio of the core to the shell is 95:5, 90:10, 80:20, 70:30, 60:40, 50:50, 40:60, or 30:70.

[0179] In some embodiments, the electrode active material is an anodic active material, wherein the anodic active material is selected from natural graphite particles, synthetic graphite particles, hard carbon, soft carbon, mesophase carbon microspheres (MCMB), Sn particles, SnO2, SnO, Li4Ti5O 12 A group consisting of particles, Si particles, Si-C composite particles, and combinations thereof.

[0180] In some embodiments, the anode active material is doped with a metallic or non-metallic element. In some embodiments, the metallic element is selected from the group consisting of Fe, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, and combinations thereof. In some embodiments, the non-metallic element is B, Si, Ge, N, P, F, S, Cl, I, Se, or combinations thereof.

[0181] In some embodiments, the anode active material comprises or is itself a core-shell composite material with a core and shell structure, wherein the core and shell are each independently selected from natural graphite particles, synthetic graphite particles, hard carbon, soft carbon, mesophase carbon microspheres (MCMB), Sn particles, SnO2, SnO, Li4Ti5O 12 A group consisting of particles, Si particles, Si-C composite particles, and combinations thereof.

[0182] In some embodiments, the core-shell composite material comprises a core containing a carbonaceous material and a shell coated on the carbonaceous material core. In some embodiments, the carbonaceous material is selected from the group consisting of soft carbon, hard carbon, natural graphite particles, synthetic graphite particles, mesophase carbon microspheres, Kish graphite, pyrolytic carbon, mesophase pitch, mesophase pitch-based carbon fibers, and combinations thereof. In some embodiments, the shell is selected from natural graphite particles, synthetic graphite particles, hard carbon, soft carbon, mesophase carbon microspheres (MCMB), Sn particles, SnO2, SnO, Li4Ti5O. 12 A group consisting of particles, Si particles, Si-C composite particles, and combinations thereof.

[0183] In some embodiments, the anode active material is not doped with any metallic or non-metallic element. In some embodiments, the anode active material is not doped with Fe, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, B, Si, Ge, N, P, F, S, Cl, I, or Se.

[0184] In some embodiments, the electrode layer may additionally include other additives to enhance electrode performance. In some embodiments, the additives may include conductive agents, surfactants, dispersants, and flexibility-enhancing additives.

[0185] In some embodiments, the electrode layer further comprises a conductive agent. The conductive agent is used to enhance the conductivity of the electrode. Any suitable material can be used as the conductive agent. In some embodiments, the conductive agent is a carbonaceous material. Some non-limiting examples include carbon, carbon black, graphite, expanded graphite, graphene, graphene nanosheets, carbon fibers, carbon nanofibers, graphitized carbon sheets, carbon nanotubes, activated carbon, Super P, 0-dimensional KS6, one-dimensional vapor-grown carbon fibers (VGCF), mesoporous carbon, and combinations thereof.

[0186] In some embodiments, the electrode layer further comprises a lithium salt. The lithium salt helps to increase the ionic conductivity of the electrode layer, thereby reducing the resistance of the electrode. In some embodiments, the lithium salt is selected from the group consisting of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium metaborate (LiBO2), lithium perchlorate (LiClO4), lithium nitrate (LiNO3), lithium bis(fluorosulfonyl)imide (LiFSI), lithium iodide (LiI), lithium tetrachloroaluminate (LiAlCl4), lithium difluoro(oxalate)borate (LiBF2C2O4), lithium dioxalateborate (LiBOB), lithium acetate (LiAc), and combinations thereof.

[0187] In some embodiments, the electrode layer further comprises an ion-conducting polymer. The ion-conducting polymer helps increase the ionic conductivity of the electrode layer, thereby reducing the resistance of the electrode. In some embodiments, the ion-conducting polymer is selected from the group consisting of polyethers, polycarbonates, polyacrylates, polysiloxanes, polyphosphazenes, polyethylene derivatives, epoxy alkane derivatives, phosphate polymers, polylysine, polyester sulfides, polyvinyl alcohol, polyvinylidene fluoride, polymers containing one or more dissociable groups, copolymers thereof, and combinations thereof. In some embodiments, the ion-conducting polymer is selected from the group consisting of polyacrylonitrile (PANs), polyvinyl carbonate (PECs), polyacrylamide (PAMs), polyethylene glycol (PEGs), polyethylene oxide (PEOs), polyhydroxyethyl methacrylate (P(HEMAs)), polyphosphonates (PPhs), polysiloxanes, polyamides (PAs), polydilactones, polyesters, polyphosphazenes (PPHOSs), polyurethanes (PUs), copolymers thereof, and combinations thereof.

[0188] In some embodiments, the electrode layer further comprises an inorganic solid electrolyte. The inorganic solid electrolyte can help increase the ionic conductivity of the electrode layer, thereby reducing the electrode resistance. In some embodiments, the inorganic solid electrolyte is selected from LPS sulfides containing sulfur and phosphorus, such as Li₂S-P₂S₅; Li 4-x Ge 1-x P x S4(LGPS, x is 0.1 to 2); Li 10±1 MP2X 12 (M = Ge, Si, Sn, Al; X = S, Se); Li 3.833 Sn 0.833 As 0.166 S4; Li4SnS4; B2S3-Li2S; 10 SnP2S 12 Li6PS5X argillium sulfide (where X is a halogen); thio-lisicon compounds, such as Li 3. 25Ge 0.25 P 0.75 S4; anti-perovskite compounds, such as Li3SX (X is Cl or Br); lithium-phosphorus-iodine-oxysulfides; lithium-phosphorus-oxysulfides; lithium-zinc-germanium sulfides; lithium-germanium sulfides; LLTO-based compounds, such as (La,Li)TiO3; Li6La2CaTa6O 12 ;Li6La2ANb2O 12(A is Ca and / or Sr); Li₂Nd₃TeSbO 12 Li3BO 2.5 N 0.5 Li9SiAlO8; LAGP compound (Li 1+x Al x Ge 2-x (PO4)3, where 0≤x≤1, 0≤y≤1); Li2O-LATP compounds, such as Al2O3-TiO2-P2O5; Li 1+x Al x Ti 2-x (PO4)3 (where 0 ≤ x ≤ 1, 0 ≤ y ≤ 1); Li 1+x Ti 2-x Al x Si y (PO4) 3-y (where 0 ≤ x ≤ 1, 0 ≤ y ≤ 1); LiAl x Zr 2-x (PO4)3 (where 0 ≤ x ≤ 1, 0 ≤ y ≤ 1); LiTi x Zr 2-x (PO4)3 (where 0≤x≤1, 0≤y≤1); LISICON type solid electrolyte; LIPON compound (Li 3+ y PO 4-x N x The group consisting of: (where 0≤x≤1, 0≤y≤1); perovskite compounds ((La,Li)TiO3); NASICON compounds, such as LiTi2(PO4)3; anti-perovskites, such as Li3OX (where X is Cl or Br); lithium-aluminum-titanium-silicon-phosphate (LATSP); lithium-aluminum oxides; lithium-vanadium-germanium oxides; lithium-zinc-germanium oxides; lithium-filled garnets, such as lithium-lanthanum-zirconium oxides; lithium-lanthanum-zirconium-aluminum oxides; lithium-lanthanum-zirconium-tantalum oxides; Li3N; lithium-aluminum chlorides and combinations thereof.

[0189] The copolymer binder used in this invention exhibits strong adhesion to the current collector. Good adhesion strength between the copolymer binder and the current collector is important because it promotes the adhesion of the electrode layer to the current collector during the manufacture of the battery electrode, preventing electrode separation and enhancing its mechanical stability. In some embodiments, the adhesion strength between the copolymer binder and the current collector is approximately 2 N / cm to approximately 6 N / cm, approximately 2 N / cm to approximately 5.8 N / cm, approximately 2 N / cm to approximately 5.6 N / cm, approximately 2 N / cm to approximately 5.4 N / cm, approximately 2 N / cm to approximately 5.2 N / cm, approximately 2 N / cm to approximately 5 N / cm, approximately 2 N / cm to approximately 4.8 N / cm, approximately 2 N / cm to approximately 4.6 N / cm, approximately 2 N / cm to approximately 4.4 N / cm, approximately 2 N / cm to approximately 4.2 N / cm, approximately 2 N / cm to approximately 4 ... Approximately 2 N / cm to 3.9 N / cm, approximately 2 N / cm to 3.8 N / cm, approximately 2 N / cm to 3.7 N / cm, approximately 2 N / cm to 3.6 N / cm, approximately 2 N / cm to 3.5 N / cm, approximately 2 N / cm to 3.4 N / cm, approximately 2 N / cm to 3.3 N / cm, approximately 2 N / cm to 3.2 N / cm, approximately 2 N / cm to 3.1 N / cm, approximately 2 N / cm to 3 N / cm, approximately 2.1 N / cm to 6 N / cm, approximately 2.2 N / cm to 6 N / cm, approximately 2.3 N / cm to 6 N / cm, Approximately 2.4 N / cm to approximately 6 N / cm, approximately 2.5 N / cm to approximately 6 N / cm, approximately 2.6 N / cm to approximately 6 N / cm, approximately 2.7 N / cm to approximately 6 N / cm, approximately 2.8 N / cm to approximately 6 N / cm, approximately 2.9 N / cm to approximately 6 N / cm, approximately 3 N / cm to approximately 6 N / cm, approximately 3.1 N / cm to approximately 6 N / cm, approximately 3.2 N / cm to approximately 6 N / cm, approximately 3.3 N / cm to approximately 6 N / cm, approximately 3.4 N / cm to approximately 6 N / cm, approximately 3.5 N / cm to approximately 6 N / cm, approximately 3.6 N / cm to approximately 6 N / cm, about 3.7N / cm to about 6N / cm, about 3.8N / cm to about 6N / cm, about 3.9N / cm to about 6N / cm, about 4N / cm to about 6N / cm, about 2.5N / cm to about 5.5N / cm, about 2.5N / cm to about 5N / cm, about 2.5N / cm to about 4.5N / cm, about 2.5N / cm to about 4N / cm, about 2.5N / cm to about 3.5N / cm, about 3N / cm to about 5N / cm, about 2.2N / cm to about 4.2N / cm or about 2.2N / cm to about 5.2N / cm.

[0190] In some embodiments, the adhesion strength between the copolymer binder and the current collector is less than 6 N / cm, less than 5.8 N / cm, less than 5.6 N / cm, less than 5.4 N / cm, less than 5.2 N / cm, less than 5 N / cm, less than 4.8 N / cm, less than 4.6 N / cm, less than 4.4 N / cm, less than 4.2 N / cm, less than 4 N / cm, less than 3.9 N / cm, less than 3.8 N / cm, less than 3.7 N / cm, less than 3.6 N / cm, less than 3.5 N / cm, less than 3.4 N / cm, less than 3.3 N / cm, less than 3.2 N / cm, less than 3.1 N / cm, less than 3 N / cm, less than 2.9 N / cm, less than 2.8 N / cm, less than 2.7 N / cm, less than 2.6 N / cm, less than 2.5 N / cm, less than 2.4 N / cm, less than 2.3 N / cm, or less than 2.2 N / cm. In some embodiments, the adhesion strength between the copolymer binder and the current collector is greater than 2 N / cm, greater than 2.1 N / cm, greater than 2.2 N / cm, greater than 2.3 N / cm, greater than 2.4 N / cm, greater than 2.5 N / cm, greater than 2.6 N / cm, greater than 2.7 N / cm, greater than 2.8 N / cm, greater than 2.9 N / cm, greater than 3 N / cm, greater than 3.1 N / cm, greater than 3.2 N / cm, greater than 3.3 N / cm, greater than 3.4 N / cm, greater than 3.5 N / cm, greater than 3.6 N / cm, greater than 3.7 N / cm, greater than 3.8 N / cm, greater than 3.9 N / cm, greater than 4 N / cm, greater than 4.2 N / cm, greater than 4.4 N / cm, greater than 4.6 N / cm, greater than 4.8 N / cm, greater than 5 N / cm, greater than 5.2 N / cm, greater than 5.4 N / cm, greater than 5.6 N / cm, or greater than 5.8 N / cm.

[0191] Furthermore, the copolymer binder used in this invention exhibits strong adhesion between the electrode layer and the current collector. Good peel strength between the electrode layer and the current collector is important, as it significantly affects the mechanical stability of the electrode and the cycle life of the battery. Therefore, the electrode should possess sufficient peel strength to withstand the harshness of the battery manufacturing process.

[0192] In some embodiments, the peel strength between the current collector and the electrode layer is in the range of about 1.0 N / cm to about 8.0 N / cm, about 1.0 N / cm to about 6.0 N / cm, about 1.0 N / cm to about 5.0 N / cm, about 1.0 N / cm to about 4.0 N / cm, about 1.0 N / cm to about 3.0 N / cm, about 1.0 N / cm to about 2.5 N / cm, about 1.0 N / cm to about 2.0 N / cm, about 1.2 N / cm to about 3.0 N / cm, about 1.2 N / cm to about 2.5 N / cm, about 1.2 N / cm to about 2.0 N / cm, about 1.5 N / cm to about 3.0 N / cm, and about 1.5 N / cm. The range is approximately 2.5 N / cm, approximately 1.5 N / cm to approximately 2.0 N / cm, approximately 1.8 N / cm to approximately 3.0 N / cm, approximately 1.8 N / cm to approximately 2.5 N / cm, approximately 2.0 N / cm to approximately 6.0 N / cm, approximately 2.0 N / cm to approximately 5.0 N / cm, approximately 2.0 N / cm to approximately 3.0 N / cm, approximately 2.0 N / cm to approximately 2.5 N / cm, approximately 2.2 N / cm to approximately 3.0 N / cm, approximately 2.5 N / cm to approximately 3.0 N / cm, approximately 3.0 N / cm to approximately 8.0 N / cm, approximately 3.0 N / cm to approximately 6.0 N / cm, or approximately 4.0 N / cm to approximately 6.0 N / cm.

[0193] In some embodiments, the peel strength between the current collector and the electrode layer is 1.0 N / cm or higher, 1.2 N / cm or higher, 1.5 N / cm or higher, 2.0 N / cm or higher, 2.2 N / cm or higher, 2.5 N / cm or higher, 3.0 N / cm or higher, 3.5 N / cm or higher, 4.5 N / cm or higher, 5.0 N / cm or higher, 5.5 N / cm or higher, 6.0 N / cm or higher, 6.5 N / cm or higher, 7.0 N / cm or higher, or 7.5 N / cm or higher. In some embodiments, the peel strength between the current collector and the electrode layer is less than 8.0 N / cm, less than 7.5 N / cm, less than 7.0 N / cm, less than 6.5 N / cm, less than 6.0 N / cm, less than 5.5 N / cm, less than 5.0 N / cm, less than 4.5 N / cm, less than 4.0 N / cm, less than 3.5 N / cm, less than 3.0 N / cm, less than 2.8 N / cm, less than 2.5 N / cm, less than 2.2 N / cm, less than 2.0 N / cm, less than 1.8 N / cm, or less than 1.5 N / cm.

[0194] In some embodiments, the surface density of each of the cathode electrode layer and the anode electrode layer is independently about 1 mg / cm³. 2 Approximately 50 mg / cm 2 Approximately 2.5 mg / cm 2 Approximately 50 mg / cm2 Approximately 5 mg / cm 2 Approximately 50 mg / cm 2 Approximately 7.5 mg / cm³ 2 Approximately 50 mg / cm 2 Approximately 10 mg / cm 2 Approximately 50 mg / cm 2 Approximately 12.5 mg / cm 2 Approximately 50 mg / cm 2 Approximately 15 mg / cm 2 Approximately 50 mg / cm 2 Approximately 17.5 mg / cm³ 2 Approximately 50 mg / cm 2 Approximately 20 mg / cm 2 Approximately 50 mg / cm 2 Approximately 25 mg / cm 2 Approximately 50 mg / cm 2 Approximately 30 mg / cm 2 Approximately 50 mg / cm 2 Approximately 1 mg / cm 2 Approximately 30 mg / cm 2 Approximately 2.5 mg / cm 2 Approximately 30 mg / cm 2 Approximately 5 mg / cm 2 Approximately 30 mg / cm 2 Approximately 7.5 mg / cm³ 2 Approximately 30 mg / cm 2 Approximately 10 mg / cm 2 Approximately 30 mg / cm 2 Approximately 12.5 mg / cm 2 Approximately 30 mg / cm 2 Approximately 15 mg / cm 2 Approximately 30 mg / cm 2 Approximately 17.5 mg / cm³ 2 Approximately 30 mg / cm 2 Approximately 20 mg / cm 2 Approximately 30 mg / cm 2 Approximately 1 mg / cm 2 Approximately 20 mg / cm 2 Approximately 2.5 mg / cm 2 Approximately 20 mg / cm 2 Approximately 5 mg / cm 2 Approximately 20 mg / cm 2 Approximately 7.5 mg / cm³ 2 Approximately 20 mg / cm 2 Approximately 10 mg / cm2 Approximately 20 mg / cm 2 Approximately 12.5 mg / cm 2 Approximately 20 mg / cm 2 Approximately 1 mg / cm 2 Approximately 15 mg / cm 2 Approximately 2.5 mg / cm 2 Approximately 15 mg / cm 2 Approximately 5 mg / cm 2 Approximately 15 mg / cm 2 Approximately 7.5 mg / cm³ 2 Approximately 15 mg / cm 2 or about 10mg / cm 2 Approximately 15 mg / cm 2 .

[0195] In some embodiments, the surface density of each of the cathode electrode layer and the anode electrode layer is independently less than 50 mg / cm³. 2 Less than 45mg / cm 2 Less than 35mg / cm 2 Less than 30mg / cm 2 Less than 25mg / cm 2 Less than 20 mg / cm 2 Less than 17.5 mg / cm 2 Less than 15mg / cm 2 Less than 12.5 mg / cm 2 Less than 10 mg / cm 2 Less than 7.5 mg / cm 2 Less than 5mg / cm 2 or less than 2.5 mg / cm 2 In some embodiments, the surface density of each of the cathode electrode layer and the anode electrode layer is independently greater than 1 mg / cm³. 2 Greater than 2.5 mg / cm 2 Greater than 5 mg / cm 2 >7.5 mg / cm 2 Greater than 10 mg / cm 2 >12.5 mg / cm 2 Greater than 15 mg / cm 2 >17.5 mg / cm 2 Greater than 20 mg / cm 2 Greater than 25 mg / cm 2 Greater than 30 mg / cm 2 Greater than 35 mg / cm 2 or greater than 40 mg / cm 2 .

[0196] In some embodiments, the density of each of the cathode electrode layer and the anode electrode layer is independently about 0.5 g / cm³. 3 Approximately 7.5 g / cm³ 3 Approximately 1g / cm 3 Approximately 7.5 g / cm³ 3 Approximately 1.5g / cm 3 Approximately 7.5 g / cm³ 3 Approximately 2g / cm 3 Approximately 7.5 g / cm³ 3 Approximately 2.5g / cm 3 Approximately 7.5 g / cm³ 3 Approximately 3g / cm 3 Approximately 7.5 g / cm³ 3 Approximately 3.5g / cm 3 Approximately 7.5 g / cm³ 3 Approximately 4g / cm 3 Approximately 7.5 g / cm³ 3 Approximately 4.5g / cm 3 Approximately 7.5 g / cm³ 3 Approximately 5g / cm 3 Approximately 7.5 g / cm³ 3 Approximately 0.5 g / cm 3 Approximately 5g / cm 3 Approximately 1g / cm 3 Approximately 5g / cm 3 Approximately 1.5g / cm 3 Approximately 5g / cm 3 Approximately 2g / cm 3 Approximately 5g / cm 3 Approximately 2.5g / cm 3 Approximately 5g / cm 3 Approximately 3g / cm 3 Approximately 5g / cm 3 Approximately 0.5 g / cm 3 Approximately 2.5 g / cm³ 3 Approximately 1g / cm 3 Approximately 2.5 g / cm³ 3 or approximately 1.5 g / cm 3 Approximately 2.5 g / cm³ 3 .

[0197] In some embodiments, the density of each of the cathode electrode layer and the anode electrode layer is independently less than 7.5 g / cm³. 3 Less than 7g / cm 3 Less than 6.5 g / cm 3 Less than 6g / cm3 Less than 5.5 g / cm 3 Less than 5g / cm 3 Less than 4.5 g / cm 3 Less than 4g / cm 3 Less than 3.5g / cm 3 Less than 3g / cm 3 Less than 2.5 g / cm 3 Less than 2g / cm 3 or less than 1.5 g / cm³ 3 In some embodiments, the density of each of the cathode electrode layer and the anode electrode layer is independently greater than 0.5 g / cm³. 3 Greater than 1g / cm 3 Greater than 1.5 g / cm 3 Greater than 2g / cm 3 Greater than 2.5 g / cm 3 Greater than 3g / cm 3 Greater than 3.5 g / cm 3 Greater than 4g / cm 3 Greater than 4.5 g / cm 3 Greater than 5g / cm 3 Greater than 5.5 g / cm 3 Greater than 6g / cm 3 or greater than 6.5 g / cm 3 .

[0198] In some embodiments, the battery containing the electrodes to be stripped is first disassembled into one or more battery fragments, wherein the one or more battery fragments contain one or more electrode fragments. There are no particular limitations on the method used to disassemble the battery, except that the minimum size of the resulting battery fragments should be larger than the sieve aperture size of the sieve used to screen the resulting screening compound-stripping solution mixture to ensure that the fragments can be screened. In some embodiments, a crusher, grinder, or cutter is used to disassemble the battery. In some embodiments, a water jet is used to disassemble the battery. In some embodiments, the battery is cryogenically treated prior to disassembly, for example, using liquid nitrogen. In some embodiments, the battery is first discharged. In some embodiments, the battery is discharged by immersion in a salt solution. In other embodiments, when a water jet is used to disassemble the battery, and / or when the battery is cryogenically treated prior to disassembly, discharging the battery is not required.

[0199] In some embodiments, when battery fragments are immersed in a stripping solution to achieve electrode stripping, the weight ratio of battery fragments to the stripping solution is about 0.01% to about 50%, about 0.02% to about 50%, about 0.05% to about 50%, about 0.1% to about 50%, about 0.2% to about 50%, about 0.5% to about 50%, about 1% to about 50%, about 2% to about 50%, about 5% to about 50%, about 10% to about 50%, about 15% to about 50%, about 20% to about 50%, about 25% to about 50%, about 30% to about 50%, or about 0.01% to about 25%. %, about 0.02% to about 25%, about 0.05% to about 25%, about 0.1% to about 25%, about 0.2% to about 25%, about 0.5% to about 25%, about 1% to about 25%, about 2% to about 25%, about 5% to about 25%, about 10% to about 25%, about 0.1% to about 15%, about 0.2% to about 15%, about 0.5% to about 15%, about 1% to about 15%, about 2% to about 15%, about 5% to about 15%, about 0.1% to about 5%, about 0.2% to about 5%, about 0.5% to about 5%, about 1% to about 5%, or about 2% to about 5%.

[0200] In some embodiments, when battery fragments are immersed in a stripping solution to achieve electrode stripping, the weight ratio of battery fragments to the stripping solution is less than 50%, less than 45%, less than 40%, less than 35%, less than 30%, less than 25%, less than 20%, less than 15%, less than 10%, less than 5%, less than 2%, less than 1%, less than 0.5%, less than 0.2%, less than 0.1%, or less than 0.05%. In some embodiments, when battery fragments are immersed in a stripping solution to achieve electrode stripping, the weight ratio of battery fragments to the stripping solution is greater than 0.01%, greater than 0.02%, greater than 0.05%, greater than 0.1%, greater than 0.2%, greater than 0.5%, greater than 1%, greater than 2%, greater than 5%, greater than 10%, greater than 15%, greater than 20%, greater than 25%, greater than 30%, greater than 35%, or greater than 40%.

[0201] In other embodiments, the electrode fragments are separated from the remaining battery fragments after disassembly but before peeling. In some embodiments, only the electrode fragments are peeled after they have been separated from the remaining battery fragments.

[0202] In some embodiments, when only electrode fragments are immersed in the stripping solution to achieve electrode stripping, the weight ratio of electrode fragments to the stripping solution is about 0.01% to about 50%, about 0.02% to about 50%, about 0.05% to about 50%, about 0.1% to about 50%, about 0.2% to about 50%, about 0.5% to about 50%, about 1% to about 50%, about 2% to about 50%, about 5% to about 50%, about 10% to about 50%, about 15% to about 50%, about 20% to about 50%, about 25% to about 50%, about 30% to about 50%, about 0.01% to about 20% of the electrode fragments. 5%, about 0.02% to about 25%, about 0.05% to about 25%, about 0.1% to about 25%, about 0.2% to about 25%, about 0.5% to about 25%, about 1% to about 25%, about 2% to about 25%, about 5% to about 25%, about 10% to about 25%, about 0.1% to about 15%, about 0.2% to about 15%, about 0.5% to about 15%, about 1% to about 15%, about 2% to about 15%, about 5% to about 15%, about 0.1% to about 5%, about 0.2% to about 5%, about 0.5% to about 5%, about 1% to about 5%, or about 2% to about 5%.

[0203] In some embodiments, when only electrode fragments are immersed in the stripping solution to achieve electrode stripping, the weight ratio of electrode fragments to the stripping solution is less than 50%, less than 45%, less than 40%, less than 35%, less than 30%, less than 25%, less than 20%, less than 15%, less than 10%, less than 5%, less than 2%, less than 1%, less than 0.5%, less than 0.2%, less than 0.1%, or less than 0.05%. In some embodiments, when only electrode fragments are immersed in the stripping solution to achieve electrode stripping, the weight ratio of electrode fragments to the stripping solution is greater than 0.01%, greater than 0.02%, greater than 0.05%, greater than 0.1%, greater than 0.2%, greater than 0.5%, greater than 1%, greater than 2%, greater than 5%, greater than 10%, greater than 15%, greater than 20%, greater than 25%, greater than 30%, greater than 35%, or greater than 40%.

[0204] The method of the present invention achieves a 100% success rate in peeling electrodes containing copolymer binders, an extremely high recovery rate (>98%), and peels the electrode layer from the current collector in a short time (~100s).

[0205] In some implementations, electrode stripping occurs at the electrode layer-current collector interface. Stripping success rate refers to the extent to which the electrode layer is stripped from the current collector. The success rate can be calculated using the formula:

[0206]

[0207] After the stripping reaction, the weight of the electrode layer present in the stripping solution will be equivalent to the weight of the successfully stripped electrode layer. The weight of the electrode layer still coated on the current collector is the weight of the electrode layer remaining on the current collector, and can be measured by manually scraping off this residual electrode layer and then weighing the scraped portion. In this invention, the stripping success rate is 100% when the electrode layer is completely stripped from the current collector. In other cases where the electrode layer is not stripped from the current collector or is partially stripped from the current collector leaving visible electrode layer adhering to the current collector, the success rate will be less than 100%.

[0208] Recovery rate refers to the percentage of the total weight of the successfully extracted and recovered electrode layer and current collector, based on the initial weight of the electrode before immersion in the stripping solution. Recovery rate is calculated only when the success rate is greater than 75%, as anything below this value is considered ineffective and economically infeasible, and therefore not worth considering for industrial production. It reflects the degree of corrosion of the useful metallic material in the electrode and / or the degree of dissolution of the useful metallic material in the stripping solution. The method disclosed herein achieves a high recovery rate, indicating that the degree of corrosion or dissolution of the metallic electrode material (e.g., the current collector) immersed in the stripping solution is negligible.

[0209] Considering the composition of the copolymer binder used, this invention provides a simple method for peeling the electrode layer from the current collector. Since the separation of the electrode layer and the current collector is a critical step in battery recycling, the method disclosed herein provides a technical solution that meets the needs of battery recycling. The method of this invention avoids both complex separation processes and contamination of the current collector, and achieves excellent material recovery (i.e., high recovery rate).

[0210] The method disclosed in this invention significantly reduces the time required for the electrode layer in the battery to peel off from the current collector without damaging the underlying current collector. With a shorter contact time between the electrode and the stripping solution, corrosion of the current collector, electrode active materials, and other electrode materials made of metal can be avoided. For example, when an electrode containing an aluminum current collector is immersed in a stripping solution containing an alkali metal phosphate, the shorter contact time allows the natural oxide layer formed on the surface of the aluminum current collector to achieve sufficient corrosion protection.

[0211] The method of the present invention can also be used to peel off packaging materials by immersing them in a peeling solution, wherein the packaging materials comprise metal and a coating applied to one or both sides of the metal, wherein the coating comprises a copolymer adhesive.

[0212] The coating may comprise metal, plastic, paper, or possibly cardboard. The metal and coating are separated by treating the packaging material with a stripping solution containing alkali metal phosphates. The methods disclosed herein can be used for stripping a wide variety of packaging materials, particularly in food and beverage packaging, to enable the recycling and reuse of every material component used in the packaging.

[0213] The following embodiments are provided to illustrate implementations of the invention, but are not intended to limit the invention to the specific embodiments listed. Unless otherwise stated, all parts and percentages are by weight. All values ​​are approximate. When numerical ranges are given, it should be understood that implementations outside the stated ranges still fall within the scope of the invention. Specific details described in the various embodiments should not be construed as essential features of the invention.

[0214] Example

[0215] The pH value of the electrode-stripping solution mixture after stripping was measured using an electrode-type pH meter (ION 2700, Eutech Instruments).

[0216] Recovery rate refers to the proportion of the total weight of the recovered electrode layer and current collector, based on the initial weight of the electrode before immersion in the stripping solution.

[0217] The peeling success rate refers to the degree to which the electrode layer is peeled off from the current collector. It can be calculated using the formula:

[0218]

[0219] Therefore, after the stripping reaction is completed or terminated, the electrode layer in the stripping solution is recovered to obtain the weight of the successfully stripped electrode layer, while the remaining electrode layer material (if any) on the electrode is manually scraped off to obtain the weight of the residual electrode layer on the current collector.

[0220] The adhesion strength of the dried adhesive layer was measured using a tensile testing machine (DZ-106A, from Dongguan Zonhow Test Equipment Co., Ltd., China). This test measures the average force, in Newtons, required to peel the adhesive layer from the current collector at a 180° angle. The average roughness depth (R) of the current collector is also measured. zThe thickness is 2 μm. The copolymer adhesive is coated onto the current collector and dried to obtain an adhesive layer with a thickness of 10 μm to 12 μm. The coated current collector is then placed in an environment with a constant temperature of 25°C and a humidity of 50% to 60% for 30 minutes. A 18 mm wide and 20 mm long strip of adhesive tape (3M; USA; model 810) is adhered to the surface of the adhesive layer. The adhesive strip is clamped in a testing machine, and the tape is folded back 180° and placed in a movable jaw, then pulled at a peel speed of 300 mm / min at room temperature. The maximum peel force measured is taken as the adhesion strength. The measurement is repeated 3 times and the average value is taken.

[0221] The peel strength of the dried electrode layer was measured using a tensile testing machine (DZ-106A, from Dongguan Zonhow Test Equipment Co., Ltd., China). This test measures the average force, in Newtons, required to peel the electrode layer from the current collector at a 180° angle. The average roughness depth (R) of the current collector is also measured. z The thickness is 2 μm. A 18 mm wide and 20 mm long strip of 3M tape (USA; model 810) is adhered to the surface of the cathode electrode layer. The cathode strip is clamped in the testing machine, and the tape is folded back 180° and placed in a movable jaw. It is then pulled at a peeling speed of 200 mm / min at room temperature. The maximum peel force measured is taken as the peel strength. The measurement is repeated three times, and the average value is taken.

[0222] Example 1

[0223] Assembly of pouch-style lithium-ion full cells

[0224] A) Preparation of polymer binder

[0225] Add 18.15 g of sodium hydroxide (NaOH) to a round-bottom flask containing 380 g of distilled water. Stir the mixture at 80 rpm for 30 minutes to obtain a first suspension.

[0226] Add 36.04 g of acrylic acid to the first suspension. Stir the mixture further at 80 rpm for 30 minutes to obtain the second suspension.

[0227] 19.04 g of acrylamide was dissolved in 10 g of deionized water to form an acrylamide solution. Then, 29.04 g of the acrylamide solution was added to the second suspension. The mixture was further heated to 55°C and stirred at 80 rpm for 45 minutes to obtain a third suspension.

[0228] Add 12.92 g of acrylonitrile to the third suspension. Stir the mixture further at 80 rpm for 10 minutes to obtain the fourth suspension.

[0229] Subsequently, 0.015 g of water-soluble free radical initiator (ammonium persulfate, APS; obtained from Aladdin Industrial Co., Ltd., China) was dissolved in 3 g of deionized water, and 0.0075 g of reducing agent (sodium bisulfite; obtained from Tianjin Damao Chemical Reagent Factory, China) was dissolved in 1.5 g of deionized water. 3.015 g of APS solution and 1.5075 g of sodium bisulfite solution were added to the fourth suspension. The mixture was stirred at 200 rpm at 55 °C for 24 hours to obtain the fifth suspension.

[0230] After complete reaction, the temperature of the fifth suspension was lowered to 25°C. 3.72 g of NaOH was dissolved in 400 g of deionized water. Subsequently, 403.72 g of sodium hydroxide solution was added dropwise to the fifth suspension to adjust the pH to 7.3 to form the sixth suspension. The sixth suspension was filtered through a 200 μm nylon mesh to form the binder material. The solids content of the binder material was 9.00 wt.%. The adhesion strength between the copolymer binder and the current collector was 3.27 N / cm. The components of the copolymer binder of Example 1 and their respective proportions are described in Table 1 below.

[0231] B) Preparation of positive electrode

[0232] A first mixture was prepared by dispersing 12 g of conductive agent (SuperP; obtained from Timcal Ltd, Bodio, Switzerland) and 100 g of polymer binder (9.00 wt.% solids) in 74 g of deionized water while stirring with a top-mounted stirrer (R20, IKA). After addition, the first mixture was further stirred at 25°C and 1200 rpm for approximately 30 minutes.

[0233] Subsequently, 276 g of NMC532 (purchased from Shandong Tianjiao New Energy Co., Ltd., China) was added to the first mixture at 25°C while simultaneously stirring with a top-mounted agitator to prepare the second mixture. The second mixture was then degassed at approximately 10 kPa for 1 hour. The second mixture was then further stirred at 1200 rpm at 25°C for approximately 60 minutes to form a homogenized cathode slurry.

[0234] Homogenized cathode slurry was coated onto both sides of a 16 μm thick aluminum foil, which served as the current collector, using a blade coater with a gap width of 120 μm. An 80 μm layer of the coated slurry on the aluminum foil was dried in an electrically heated oven at 85°C for approximately 120 minutes to form the cathode electrode layer. The electrode was then pressed to reduce the thickness of the cathode electrode layer to 34 μm. The surface density of the cathode electrode layer on the current collector was 16.00 mg / cm³. 2 .

[0235] C) Preparation of negative electrode

[0236] A negative electrode slurry was prepared by mixing 93 wt.% graphite (BTR NewEnergy Materials Inc., Shenzhen, Guangdong, China) with 1 wt.% carboxymethyl cellulose (CMC, BSH-12, DKS Co., Ltd., Japan) as a binder, 3 wt.% SBR (AL-2001, NIPPONA & L Corporation, Japan) as a conductor, and 3 wt.% carbon black as a conductive agent in deionized water. The anode slurry had a solids content of 51.5 wt.%. The slurry was coated onto both sides of an 8 μm thick copper foil using a doctor blade coater with a gap width of approximately 120 μm. The coated slurry on the copper foil was dried in a hot air dryer at approximately 85°C for 120 minutes to obtain the negative electrode. The electrode was then pressed to reduce the thickness of the anode electrode layer to 60 μm, and the surface density of the anode electrode layer was 10 mg / cm³. 2 .

[0237] D) Assembly of pouch-style cell

[0238] After drying, the resulting cathode and anode coatings were cut into rectangular sheets with dimensions of 5.2 cm × 8.5 cm and 5.4 cm × 8.7 cm, respectively, for the preparation of cathode and anode sheets. Pouch cells were fabricated by alternately stacking the cathode and anode sheets and separating them with a 25 μm thick porous polyethylene separator (Celgard, LLC, USA). The electrolyte was a solution containing LiPF6 (1M) in a 1:1:1 volume ratio mixture of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC). The cells were assembled in a high-purity argon atmosphere with moisture and oxygen content <1 ppm. After injecting the electrolyte, the pouch cells were vacuum-sealed and then mechanically pressurized using a standard-shaped stamping tool.

[0239] The assembled pouch cells were then subjected to repeated charge and discharge cycles at a constant current rate of 1 C between 3.0 V and 4.2 V to simulate real-world usage. The actual battery capacity was approximately 5 Ah. After 800 cycles, the nominal capacity dropped to less than 80% of its initial rated capacity.

[0240] Recovery of cells

[0241] A) Discharge and disassembly of pouch-style cell

[0242] The spent lithium-ion batteries (0.5 kg) were completely discharged by immersing them in a 6% NaCl solution for 12 hours. After discharge, the lithium-ion batteries were mechanically disassembled using a cutting machine to recover the electrodes. The electrodes were cut into small pieces with an average length of approximately 2 cm to approximately 4 cm.

[0243] B) Preparation of stripping solution

[0244] Add 5.31 g of anhydrous tripotassium phosphate (Sigma-Aldrich, USA) to 1000 g of deionized water to form a stripping solution with a concentration of 0.025 M.

[0245] C) Immersion of cathode in stripping solution

[0246] 5.07 g of cathode was placed in a container containing 1000 g of stripping solution heated to 30 °C. The cathode layer separated from the aluminum foil. Once the cathode layer was observed to have been stripped, the stripping solution containing tripotassium phosphate and deionized water was passed through a sieve with a mesh width of 4 mm to remove it, thus recovering the cathode layer and aluminum foil. The stripping solution could be further reused for stripping electrodes. The recovered cathode layer and aluminum foil were dried in an oven at 80 °C for 5 hours at atmospheric pressure, with a recovery rate of 99.00%. The stripping success rate and recovery rate of the stripped cathode material were measured and are illustrated in Table 1 below.

[0247] Assembly of pouch-style lithium-ion full cells of Examples 2-4

[0248] A pouch-type lithium-ion battery was prepared using the method described in Example 1. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 1.

[0249] Recovery of cells of Example 2

[0250] A) Discharge and disassembly of pouch-style cell

[0251] The spent lithium-ion batteries were discharged and disassembled using the same method described in Example 1.

[0252] B) Preparation of stripping solution

[0253] 10.61 g of anhydrous tripotassium phosphate (Sigma-Aldrich, USA) was added to 1000 g of deionized water to form a stripping solution with a concentration of 0.05 M.

[0254] C) Immersion of cathode in stripping solution

[0255] The cathode was immersed and stripped using the method described in Example 1, except that the stripping solution described above was used. The stripping success rate and recovery rate of the stripped cathode material were measured and are illustrated in Table 1 below.

[0256] Recovery of cells of Example 3

[0257] A) Discharge and disassembly of pouch-style cell

[0258] The spent lithium-ion batteries were discharged and disassembled using the same method described in Example 1.

[0259] B) Preparation of stripping solution

[0260] 106.1 g of anhydrous tripotassium phosphate (Sigma-Aldrich, USA) was added to 1000 g of deionized water to form a 0.5 M stripping solution.

[0261] C) Immersion of cathode in stripping solution

[0262] The cathode was immersed and stripped using the method described in Example 1, except that the stripping solution described above was used. The stripping success rate and recovery rate of the stripped cathode material were measured and are illustrated in Table 1 below.

[0263] Recovery of cells of Example 4

[0264] A) Discharge and disassembly of pouch-style cell

[0265] The spent lithium-ion batteries were discharged and disassembled using the same method described in Example 1.

[0266] B) Preparation of stripping solution

[0267] Add 318.4 g of anhydrous tripotassium phosphate (Sigma-Aldrich, USA) to 1000 g of deionized water to form a stripping solution with a concentration of 1.5 M.

[0268] C) Immersion of cathode in stripping solution

[0269] The cathode was immersed and stripped using the method described in Example 1, except that the stripping solution described above was used. The stripping success rate and recovery rate of the stripped cathode material were measured and are illustrated in Table 1 below.

[0270] Preparation of polymer binder of Example 5

[0271] Add 27.27 g of sodium hydroxide (NaOH) to a round-bottom flask containing 380 g of distilled water. Stir the mixture at 80 rpm for 30 minutes to obtain a first suspension.

[0272] Add 52.48g of acrylic acid to the first suspension. Stir the mixture further at 80rpm for 30 minutes to obtain the second suspension.

[0273] 8.63 g of acrylamide was dissolved in 10 g of deionized water to form an acrylamide solution. Then, 18.63 g of the acrylamide solution was added to the second suspension. The mixture was further heated to 55°C and stirred at 80 rpm for 45 minutes to obtain a third suspension.

[0274] Add 8.59 g of acrylonitrile to the third suspension. Stir the mixture further at 80 rpm for 10 minutes to obtain the fourth suspension.

[0275] In addition, 0.015 g of water-soluble free radical initiator (ammonium persulfate, APS; purchased from Aladdin Industrial Co., Ltd., China) was dissolved in 3 g of deionized water, and 0.0075 g of reducing agent (sodium bisulfite; purchased from Tianjin Damao Chemical Reagent Factory, China) was dissolved in 1.5 g of deionized water. 3.015 g of APS solution and 1.5075 g of sodium bisulfite solution were added to the fourth suspension. The mixture was stirred at 55°C and 200 rpm for 24 hours to obtain the fifth suspension.

[0276] After complete reaction, the temperature of the fifth suspension was lowered to 25°C. 3.72 g of NaOH was dissolved in 400 g of deionized water. Subsequently, 403.72 g of sodium hydroxide solution was added dropwise to the fifth suspension to adjust the pH to 7.3 to form the sixth suspension. The sixth suspension was filtered through a 200 μm nylon mesh to form the binder material. The components of the copolymer binder of Example 5 and their respective proportions are described in Table 1 below.

[0277] Preparation of polymer binder of Example 6

[0278] Add 18.37 g of sodium hydroxide (NaOH) to a round-bottom flask containing 380 g of distilled water. Stir the mixture at 80 rpm for 30 minutes to obtain a first suspension.

[0279] Add 36.44 g of acrylic acid to the first suspension. Stir the mixture further at 80 rpm for 30 minutes to obtain the second suspension.

[0280] 23.73 g of acrylamide was dissolved in 10 g of deionized water to form an acrylamide solution. Then, 33.73 g of the acrylamide solution was added to the second suspension. The mixture was further heated to 55°C and stirred at 80 rpm for 45 minutes to obtain a third suspension.

[0281] Add 9.12 g of acrylonitrile to the third suspension. Stir the mixture further at 80 rpm for 10 minutes to obtain the fourth suspension.

[0282] In addition, 0.015 g of water-soluble free radical initiator (ammonium persulfate, APS; purchased from Aladdin Industrial Co., Ltd., China) was dissolved in 3 g of deionized water, and 0.0075 g of reducing agent (sodium bisulfite; purchased from Tianjin Damao Chemical Reagent Factory, China) was dissolved in 1.5 g of deionized water. 3.015 g of APS solution and 1.5075 g of sodium bisulfite solution were added to the fourth suspension. The mixture was stirred at 55°C and 200 rpm for 24 hours to obtain the fifth suspension.

[0283] After complete reaction, the temperature of the fifth suspension was lowered by 25°C. 3.72 g of NaOH was dissolved in 400 g of deionized water. Subsequently, 403.72 g of sodium hydroxide solution was added dropwise to the fifth suspension to adjust the pH to 7.3 to form the sixth suspension. The sixth suspension was filtered through a 200 μm nylon mesh to form the binder material. The components of the copolymer binder of Example 6 and their respective proportions are described in Table 1 below.

[0284] Assembly of pouch-style lithium-ion full cells of Examples 5-6

[0285] A) Preparation of positive electrode

[0286] The positive electrode was prepared by the method described in Example 2, except that the binder material prepared in Examples 5-6 was used to prepare the cathode of Examples 5-6 respectively.

[0287] B) Preparation of negative electrode

[0288] The negative electrode was prepared using the method described in Example 2.

[0289] C) Assembly of pouch-style cell

[0290] A pouch-type lithium-ion battery was prepared using the method described in Example 2. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 2.

[0291] Recovery of cells of Examples 5-6

[0292] The battery was recovered using the same method as in Example 2. The success rate and recovery rate of the stripped cathode material were measured and are illustrated in Table 1 below.

[0293] Assembly of pouch-style lithium-ion full cells of Example 7

[0294] A pouch-type lithium-ion battery was prepared using the method described in Example 2. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 2.

[0295] Recovery of cells of Example 7

[0296] A) Discharge and disassembly of pouch-style cell

[0297] The spent lithium-ion batteries were discharged and disassembled using the same method described in Example 2.

[0298] B) Preparation of stripping solution

[0299] Add 8.20 g of anhydrous trisodium phosphate (Sigma-Aldrich, USA) to 1000 g of deionized water to form a stripping solution with a concentration of 0.05 M.

[0300] C) Immersion of cathode in stripping solution

[0301] The cathode was immersed and stripped using the method described in Example 2, except that the stripping solution was used. The stripping success rate and recovery rate of the stripped cathode material were measured and are illustrated in Table 1 below.

[0302] Assembly of pouch-style lithium-ion full cells of Example 8

[0303] A pouch-type lithium-ion battery was prepared using the method described in Example 2, except that 276 g of NMC532 was replaced with the same weight of LCO. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 2.

[0304] Assembly of pouch-style lithium-ion full cells of Example 9

[0305] A pouch-type lithium-ion battery was prepared using the method described in Example 2, except that 276 g of NMC532 was replaced with the same weight of LFP (Tianjin Sitelan Energy Technology Co., Ltd., China). The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 2.

[0306] Assembly of pouch-style lithium-ion full cells of Example 10

[0307] A pouch-type lithium-ion battery was prepared using the method described in Example 2, except that 50.08 g of 2-ethylacrylic acid was used instead of 36.04 g of acrylic acid in the preparation of the second suspension when preparing the polymer binder. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 2.

[0308] Assembly of pouch-style lithium-ion full cells of Example 11

[0309] A pouch-type lithium-ion battery was prepared using the method described in Example 2, except that 54.08 g of vinyl sulfonic acid was used instead of 36.04 g of acrylic acid in the preparation of the polymer binder and the second suspension. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 2.

[0310] Recovery of cells of Examples 8-11

[0311] The battery was recovered using the same method as in Example 2. The success rate and recovery rate of the stripped cathode material were measured and are illustrated in Table 1 below.

[0312] Example 12

[0313] Assembly of pouch-style lithium-ion full cells

[0314] A) Preparation of polymer binder

[0315] Add 7.45 g of sodium hydroxide (NaOH) to a round-bottom flask containing 380 g of distilled water. Stir the mixture at 80 rpm for 30 minutes to obtain a first suspension.

[0316] Add 16.77g of acrylic acid to the first suspension. Stir the mixture further at 80rpm for 30 minutes to obtain the second suspension.

[0317] 7.19 g of acrylamide was dissolved in 10 g of deionized water to form an acrylamide solution. Then, 17.19 g of the acrylamide solution was added to the second suspension. The mixture was further heated to 55°C and stirred at 80 rpm for 45 minutes to obtain a third suspension.

[0318] Add 35.95 g of acrylonitrile to the third suspension. Stir the mixture further at 80 rpm for 10 minutes to obtain the fourth suspension.

[0319] Subsequently, 0.015 g of water-soluble free radical initiator (ammonium persulfate, APS; obtained from Aladdin Industrial Co., Ltd., China) was dissolved in 3 g of deionized water, and 0.0075 g of reducing agent (sodium bisulfite; obtained from Tianjin Damao Chemical Reagent Factory, China) was dissolved in 1.5 g of deionized water. 3.015 g of APS solution and 1.5075 g of sodium bisulfite solution were added to the fourth suspension. The mixture was stirred at 200 rpm at 55°C for 24 hours to obtain the fifth suspension.

[0320] After complete reaction, the temperature of the fifth suspension was lowered to 25°C. 3.72 g of NaOH was dissolved in 400 g of deionized water. Subsequently, 403.72 g of sodium hydroxide solution was added dropwise to the fifth suspension to adjust the pH to 7.3 to form the sixth suspension. The sixth suspension was filtered through a 200 μm nylon mesh to form the binder material. The components of the copolymer binder of Example 12 and their respective proportions are described in Table 1 below.

[0321] B) Preparation of positive electrode

[0322] The positive electrode was prepared by the method described in Example 1, except that the binder material described above was used.

[0323] C) Preparation of negative electrode

[0324] The negative electrode was prepared using the method described in Example 1.

[0325] D) Assembly of pouch-style cell

[0326] A pouch-type lithium-ion battery was prepared using the method described in Example 1. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 1.

[0327] Recovery of cells of Example 12

[0328] The battery was recovered using the same method as in Example 1, except that the stripping solution was heated to 70°C. The stripping success rate and recovery rate of the cathode material were measured and are illustrated in Table 1 below.

[0329] Assembly of pouch-style lithium-ion full cells of Examples 13-16

[0330] A pouch-type lithium-ion battery was prepared using the method described in Example 12. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 12.

[0331] Recovery of cells of Example 13

[0332] A) Discharge and disassembly of pouch-style cell

[0333] The spent lithium-ion batteries were discharged and disassembled using the same method described in Example 1.

[0334] B) Preparation of stripping solution

[0335] Add 21.2 g of anhydrous tripotassium phosphate (Sigma-Aldrich, USA) to 1000 g of deionized water to form a 0.1 M stripping solution.

[0336] C) Immersion of cathode in stripping solution

[0337] The cathode was immersed and stripped using the method described in Example 1, except that the stripping solution described above was used. The stripping success rate and recovery rate of the stripped cathode material were measured and are illustrated in Table 1 below.

[0338] Recovery of cells of Example 14

[0339] A) Discharge and disassembly of pouch-style cell

[0340] The spent lithium-ion batteries were discharged and disassembled using the same method described in Example 1.

[0341] B) Preparation of stripping solution

[0342] Add 53.1 g of anhydrous tripotassium phosphate (Sigma-Aldrich, USA) to 1000 g of deionized water to form a stripping solution with a concentration of 0.25 M.

[0343] C) Immersion of cathode in stripping solution

[0344] The cathode was immersed and stripped using the method described in Example 1, except that the stripping solution described above was used. The stripping success rate and recovery rate of the stripped cathode material were measured and are illustrated in Table 1 below.

[0345] Recovery of cells of Example 15

[0346] The battery was recovered using the same method as in Example 4. The success rate and recovery rate of the stripped cathode material were measured and are illustrated in Table 1 below.

[0347] Recovery of cells of Example 16

[0348] A) Discharge and disassembly of pouch-style cell

[0349] The spent lithium-ion batteries were discharged and disassembled using the same method described in Example 1.

[0350] B) Preparation of stripping solution

[0351] Add 41.0 g of anhydrous trisodium phosphate (Sigma Aldrich, USA) to 1000 g of deionized water to form a stripping solution with a concentration of 0.25 M.

[0352] C) Immersion of cathode in stripping solution

[0353] The cathode was immersed and stripped using the method described in Example 1, except that the stripping solution described above was used. The stripping success rate and recovery rate of the stripped cathode material were measured and are illustrated in Table 1 below.

[0354] Preparation of polymer binder of Example 17

[0355] Add 5.42 g of sodium hydroxide (NaOH) to a round-bottom flask containing 380 g of distilled water. Stir the mixture at 80 rpm for 30 minutes to obtain a first suspension.

[0356] Add 13.12 g of acrylic acid to the first suspension. Stir the mixture further at 80 rpm for 30 minutes to obtain the second suspension.

[0357] 7.91 g of acrylamide was dissolved in 10 g of deionized water to form an acrylamide solution. Then, 17.91 g of the acrylamide solution was added to the second suspension. The mixture was further heated to 55°C and stirred at 80 rpm for 45 minutes to obtain a third suspension.

[0358] Add 38.11 g of acrylonitrile to the third suspension. Stir the mixture further at 80 rpm for 10 minutes to obtain the fourth suspension.

[0359] In addition, 0.015 g of water-soluble free radical initiator (ammonium persulfate, APS; purchased from Aladdin Industrial Co., Ltd., China) was dissolved in 3 g of deionized water, and 0.0075 g of reducing agent (sodium bisulfite; purchased from Tianjin Damao Chemical Reagent Factory, China) was dissolved in 1.5 g of deionized water. 3.015 g of APS solution and 1.5075 g of sodium bisulfite solution were added to the fourth suspension. The mixture was stirred at 55°C and 200 rpm for 24 hours to obtain the fifth suspension.

[0360] After complete reaction, the temperature of the fifth suspension was lowered to 25°C. 3.72 g of NaOH was dissolved in 400 g of deionized water. Subsequently, 403.72 g of sodium hydroxide solution was added dropwise to the fifth suspension to adjust the pH to 7.3 to form the sixth suspension. The sixth suspension was filtered through a 200 μm nylon mesh to form the binder material. The components of the copolymer binder of Example 17 and their respective proportions are described in Table 1 below.

[0361] Preparation of polymer binder of Example 18

[0362] Add 5.02 g of sodium hydroxide (NaOH) to a round-bottom flask containing 380 g of distilled water. Stir the mixture at 80 rpm for 30 minutes to obtain a first suspension.

[0363] Add 12.39 g of acrylic acid to the first suspension. Stir the mixture further at 80 rpm for 30 minutes to obtain the second suspension.

[0364] 23.73 g of acrylamide was dissolved in 10 g of deionized water to form an acrylamide solution. Then, 33.73 g of the acrylamide solution was added to the second suspension. The mixture was further heated to 55°C and stirred at 80 rpm for 45 minutes to obtain a third suspension.

[0365] Add 26.84 g of acrylonitrile to the third suspension. Stir the mixture further at 80 rpm for 10 minutes to obtain the fourth suspension.

[0366] In addition, 0.015 g of water-soluble free radical initiator (ammonium persulfate, APS; purchased from Aladdin Industrial Co., Ltd., China) was dissolved in 3 g of deionized water, and 0.0075 g of reducing agent (sodium bisulfite; purchased from Tianjin Damao Chemical Reagent Factory, China) was dissolved in 1.5 g of deionized water. 3.015 g of APS solution and 1.5075 g of sodium bisulfite solution were added to the fourth suspension. The mixture was stirred at 55°C and 200 rpm for 24 hours to obtain the fifth suspension.

[0367] After complete reaction, the temperature of the fifth suspension was lowered by 25°C. 3.72 g of NaOH was dissolved in 400 g of deionized water. Subsequently, 403.72 g of sodium hydroxide solution was added dropwise to the fifth suspension to adjust the pH to 7.3 to form the sixth suspension. The sixth suspension was filtered through a 200 μm nylon mesh to form the binder material. The components of the copolymer binder of Example 18 and their respective proportions are described in Table 1 below.

[0368] Assembly of pouch-style lithium-ion full cells of Examples 17-18

[0369] A) Preparation of positive electrode

[0370] The positive electrode was prepared by the method described in Example 14, except that the binder material prepared in Examples 17-18 was used to prepare the cathode of Examples 17-18 respectively.

[0371] B) Preparation of negative electrode

[0372] The negative electrode was prepared by the method described in Example 14.

[0373] C) Assembly of pouch-style cell

[0374] A pouch-type lithium-ion battery was prepared using the method described in Example 14. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 14.

[0375] Assembly of pouch-style lithium-ion full cells of Example 19

[0376] A pouch-type lithium-ion battery was prepared using the method described in Example 14, except that the same weight of LCO was used instead of 276g of NMC532. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 14.

[0377] Assembly of pouch-style lithium-ion full cells of Example 20

[0378] A pouch-type lithium-ion battery was prepared using the method described in Example 14, except that 276 g of NMC532 was replaced with the same weight of LFP (Tianjin Sitelan Energy Technology Co., Ltd., China). The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 14.

[0379] Assembly of pouch-style lithium-ion full cells of Example 21

[0380] A pouch-type lithium-ion battery was prepared using the method described in Example 14, except that 23.30 g of 2-ethylacrylic acid was used instead of 16.77 g of acrylic acid in the preparation of the polymer binder and the second suspension. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 14.

[0381] Assembly of pouch-style lithium-ion full cells of Example 22

[0382] A pouch-type lithium-ion battery was prepared using the method described in Example 14, except that 25.16 g of vinyl sulfonic acid was used instead of 16.77 g of acrylic acid in the preparation of the polymer binder and the second suspension. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 14.

[0383] Recovery of cells of Example 1722

[0384] The battery was recovered using the same method as in Example 14. The success rate and recovery rate of the stripped cathode material were measured and are illustrated in Table 1 below.

[0385] Assembly of pouch-style lithium-ion full cells of Comparative Example 1

[0386] A) Preparation of positive electrode

[0387] In a 500mL round-bottom flask, 10g of polyvinylidene fluoride (PVDF) was added as a polymer binder. 5130 (purchased from Solvay, Belgium) was dispersed in 250g NMP (≥99%, Sigma-Aldrich, USA) and stirred at 500rpm for about 3 hours with a top-mounted stirrer to prepare the first suspension.

[0388] Subsequently, 15g of SuperP was added to the first suspension and stirred at 1200rpm for 30 minutes to obtain the second suspension.

[0389] 225 g of NMC532 was dispersed into a second suspension at 25 °C while being stirred with a top-mounted stirrer to prepare a third suspension. The third suspension was then degassed at approximately 10 kPa for 1 hour. The third suspension was further stirred at 1200 rpm at 25 °C for approximately 90 minutes to form a homogenized cathode slurry.

[0390] A homogenized cathode paste was coated onto both sides of a 16 μm thick aluminum foil, serving as the current collector, using a blade coater with a 120 μm gap. An 80 μm layer of the coated paste on the aluminum foil was dried in an electrically heated oven at 85°C to form the cathode electrode layer. The drying time was approximately 120 minutes. The electrode was then pressed to reduce the thickness of the cathode electrode layer to 34 μm.

[0391] B) Preparation of negative electrode

[0392] The negative electrode was prepared using the same method as in Example 1.

[0393] C) Assembly of pouch-style cell

[0394] The pouch cell was assembled using the same method as in Example 1. The assembled pouch cell was then repeatedly cycled using the same method as in Example 1.

[0395] Recovery of cells of Comparative Example 1

[0396] A) Discharge and disassembly of pouch-style cell

[0397] The spent lithium-ion batteries were discharged and disassembled using the same method described in Example 1.

[0398] B) Preparation of stripping solution

[0399] Add 212g of anhydrous tripotassium phosphate (Sigma-Aldrich, USA) to 1000g of deionized water to form a stripping solution with a concentration of 1.0M.

[0400] C) Immersion of cathode in stripping solution

[0401] The cathode was immersed and stripped using the method described in Example 1, except that the stripping solution was used. If the stripping was incomplete, the reaction was terminated after fifteen minutes. The stripping success rate and recovery rate of the cathode material were measured and are shown in Table 2 below.

[0402] Assembly of pouch-style lithium-ion full cells of Comparative Example 2

[0403] A pouch-type lithium-ion battery was prepared using the method described in Example 1. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 1.

[0404] Assembly of pouch-style lithium-ion full cells of Comparative Example 3

[0405] A pouch-type lithium-ion battery was prepared using the method described in Example 12. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 12.

[0406] Recovery of batteries of Comparative Examples 2-3

[0407] The battery was recovered using the same method as in Example 1, except that no stripping agent was added when preparing the stripping solution; only 1000g of deionized water was added. If stripping was incomplete, the reaction was terminated after fifteen minutes. The stripping success rate and recovery rate of the cathode material were measured and are illustrated in Table 2 below.

[0408] Assembly of pouch-style lithium-ion full cells of Comparative Example 4

[0409] A pouch-type lithium-ion battery was prepared using the method described in Example 1. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 1.

[0410] Assembly of pouch-style lithium-ion full cells of Comparative Example 5

[0411] A pouch-type lithium-ion battery was prepared using the method described in Example 12. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 12.

[0412] Recovery of batteries of Comparative Example 4

[0413] A) Discharge and disassembly of pouch-style batteries

[0414] The spent lithium-ion batteries were discharged and disassembled using the same method described in Example 1.

[0415] B) Preparation of stripping solution

[0416] Add 1.0 g of anhydrous sodium hydroxide (Sigma-Aldrich, USA) to 1000 g of deionized water to form a stripping solution with a concentration of 0.025 M.

[0417] C) Immersion of cathodes in stripping solution

[0418] The cathode was immersed and stripped using the method described in Example 1, except that the stripping solution was used. If the stripping was incomplete, the reaction was terminated after fifteen minutes. The stripping success rate and recovery rate of the cathode material were measured and are shown in Table 2 below.

[0419] Recovery of batteries of Comparative Example 5

[0420] A) Discharge and disassembly of pouch-style batteries

[0421] The spent lithium-ion batteries were discharged and disassembled using the same method described in Example 1.

[0422] B) Preparation of stripping solution

[0423] Add 4.0 g of anhydrous sodium hydroxide (Sigma-Aldrich, USA) to 1000 g of deionized water to form a stripping solution with a concentration of 0.1 M.

[0424] C) Immersion of cathodes in stripping solution

[0425] The cathode was immersed and stripped using the method described in Example 1, except that the stripping solution was used. If the stripping was incomplete, the reaction was terminated after fifteen minutes. The stripping success rate and recovery rate of the cathode material were measured and are shown in Table 2 below.

[0426] Assembly of pouch-style lithium-ion full cells of Comparative Example 6

[0427] A pouch-type lithium-ion battery was prepared using the method described in Example 14, except that 0.16 g of sodium hydroxide was added during the preparation of the first suspension, 3.64 g of acrylic acid was added during the preparation of the second suspension, 14.38 g of acrylamide was added during the preparation of the third suspension, and 40.25 g of acrylonitrile was added during the preparation of the fourth suspension. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 14.

[0428] Recovery of batteries of Comparative Example 6

[0429] The battery was recovered using the same method as in Example 14. If the stripping was incomplete, the reaction was terminated after fifteen minutes. The stripping success rate and recovery rate of the cathode material were measured and are illustrated in Table 2 below.

[0430] Assembly of pouch-style lithium-ion full cells of Comparative Example 7

[0431] A pouch-type lithium-ion battery was prepared using the method described in Example 12. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 12.

[0432] Assembly of pouch-style lithium-ion full cells of Comparative Example 8

[0433] A pouch-type lithium-ion battery was prepared using the method described in Example 1. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 1.

[0434] Recovery of batteries of Comparative Example 7

[0435] A) Discharge and disassembly of pouch-style batteries

[0436] The spent lithium-ion batteries were discharged and disassembled using the same method described in Example 1.

[0437] B) Preparation of stripping solution

[0438] Add 164g of anhydrous sodium acetate (Sigma-Aldrich, USA) to 1000g of deionized water to form a stripping solution with a concentration of 2.0M.

[0439] C) Immersion of cathodes in stripping solution

[0440] The cathode was immersed and stripped using the method described in Example 1, except that the stripping solution was used. If the stripping was incomplete, the reaction was terminated after fifteen minutes. The stripping success rate and recovery rate of the cathode material were measured and are shown in Table 2 below.

[0441] Recovery of batteries of Comparative Example 8

[0442] The battery was recovered using the same method as in Comparative Example 7. The success rate and recovery rate of the stripped cathode material were measured and are shown in Table 2 below.

[0443] Assembly of pouch-style lithium-ion full cells of Comparative Example 9

[0444] A pouch-type lithium-ion battery was prepared using the method described in Example 1, except that 9.47 g of sodium hydroxide was added during the preparation of the first suspension, 20.41 g of acrylic acid was added during the preparation of the second suspension, no acrylamide was added during the preparation of the third suspension, and 38.64 g of acrylonitrile was added during the preparation of the fourth suspension. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 1.

[0445] Recovery of batteries of Comparative Example 9

[0446] The battery was recovered using the same method as in Example 1. If the stripping was incomplete, the reaction was terminated after fifteen minutes. The stripping success rate and recovery rate of the cathode material were measured and are illustrated in Table 2 below.

[0447]

[0448]

[0449] Although the invention has been described in conjunction with a limited number of embodiments, specific features of one embodiment should not limit other embodiments of the invention. In some embodiments, the method may include multiple steps not mentioned herein. In other embodiments, the method does not include or substantially does not contain any steps not listed herein. Variations and modifications based on the described embodiments exist. The appended claims are intended to cover all such variations and modifications that fall within the scope of the invention.

Claims

1. A method of delaminating a composite by immersing the composite in a delaminating solution, wherein the composite comprises a metal substrate and a coating applied on one or both sides of the metal substrate, wherein the coating comprises a copolymer binder, wherein the copolymer binder comprises structural units (a) derived from a monomer selected from the group consisting of a carboxylic acid group-containing monomer, a sulfonic acid group-containing monomer, a phosphonic acid group-containing monomer, a carboxylic acid salt group-containing monomer, a sulfonic acid salt group-containing monomer, a phosphonic acid salt group-containing monomer, and combinations thereof, wherein the structural units (a) in the copolymer binder are present in a proportion of 15 to 80% by mole based on the total moles of monomer units in the copolymer binder, wherein the copolymer binder further comprises structural units (b) derived from a monomer selected from the group consisting of an amide group-containing monomer, a hydroxyl group-containing monomer, and combinations thereof, wherein the copolymer binder further comprises structural units (c) derived from a monomer selected from the group consisting of a nitrile group-containing monomer, an ester group-containing monomer, an epoxy group-containing monomer, a fluorine-containing monomer, and combinations thereof, wherein the delaminating solution comprises a delaminating agent and an aqueous solvent.

2. The method of claim 1, wherein the concentration of the delaminating agent in the delaminating solution is 0.01 to 3.0 M.

3. The method of claim 2, wherein the delaminating agent is selected from the group consisting of alkali metal phosphates consisting of monosodium phosphate, disodium phosphate, trisodium phosphate, monosodium pyrophosphate, disodium pyrophosphate, trisodium pyrophosphate, tetrasodium pyrophosphate, monosodium triphosphate, disodium triphosphate, trisodium triphosphate, tetrasodium triphosphate, pentasodium triphosphate, potassium monophosphate, potassium di-phosphate, potassium tri-phosphate, potassium monopyrophosphate, potassium di-pyrophosphate, potassium tri-pyrophosphate, potassium tetra-pyrophosphate, potassium monotriphosphate, potassium di-triphosphate, potassium tri-triphosphate, potassium tetra-triphosphate, potassium penta-triphosphate, rubidium monophosphate, rubidium di-phosphate, rubidium tri-phosphate, rubidium monopyrophosphate, rubidium di-pyrophosphate, rubidium tri-pyrophosphate, rubidium tetra-pyrophosphate, rubidium monotriphosphate, rubidium di-triphosphate, rubidium tri-triphosphate, rubidium tetra-triphosphate, rubidium penta-triphosphate, cesium monophosphate, cesium di-phosphate, cesium tri-phosphate, cesium monopyrophosphate, cesium di-pyrophosphate, cesium tri-pyrophosphate, cesium tetra-pyrophosphate, cesium monotriphosphate, cesium di-triphosphate, cesium tri-triphosphate, cesium tetra-triphosphate, cesium penta-triphosphate, and combinations thereof.

4. The method of claim 2, wherein the aqueous solvent is water.

5. The method of claim 2, wherein the aqueous solvent comprises water as a major component and a minor component, wherein water is present in the aqueous solvent in a proportion of greater than 51% and less than 100% by weight, and wherein the minor component is selected from the group consisting of methanol, ethanol, isopropanol, n-propanol, t-butanol, n-butanol, acetone, dimethyl ketone, methyl ethyl ketone, ethyl acetate, isopropyl acetate, propyl acetate, butyl acetate, and combinations thereof.

6. The method of claim 1, wherein the structural units (a) in the copolymer binder comprise 17.5% to 75% by mole based on the total number of moles of monomer units in the copolymer binder.

7. The method of claim 1, wherein the carboxylic acid group-containing monomer is selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, 2-butyl crotonic acid, cinnamic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, 4,4-dimethyl itaconic acid, 2-ethyl acrylic acid, isocrotonic acid, cis-2-pentenoic acid, trans-2-pentenoic acid, angelic acid, tiglic acid, 3,3-dimethyl acrylic acid, 3-propyl acrylic acid, trans-2-methyl-3-ethyl acrylic acid, cis-2-methyl-3-ethyl acrylic acid, 3-isopropyl acrylic acid, trans-3-methyl-3-ethyl acrylic acid, cis-3-methyl-3-ethyl acrylic acid, 2-isopropyl acrylic acid, trimethyl acrylic acid, 2-methyl-3,3-diethyl acrylic acid, 3-butyl acrylic acid, 2-butyl acrylic acid, 2-pentyl acrylic acid, 2-methyl-2-hexenoic acid, trans-3-methyl-2-hexenoic acid, 3-methyl-3-propyl acrylic acid, 2-ethyl-3-propyl acrylic acid, 2,3-diethyl acrylic acid, 3,3-diethyl acrylic acid, 3-methyl-3-hexyl acrylic acid, 3-methyl-3-tert-butyl acrylic acid, 2-methyl-3-pentyl acrylic acid, 3-methyl-3-pentyl acrylic acid, 4-methyl-2-hexenoic acid, 4-ethyl-2-hexenoic acid, 3-methyl-2-ethyl-2-hexenoic acid, 3-tert-butyl acrylic acid, 2,3-dimethyl-3-ethyl acrylic acid, 3,3-dimethyl-2-ethyl acrylic acid, 3-methyl-3-isopropyl acrylic acid, 2-methyl-3-isopropyl acrylic acid, trans-2-octenoic acid, cis-2-octenoic acid, trans-2-decenoic acid, a-acetoxy acrylic acid, β-trans-aryloxy acrylic acid, a-chloro-β-E-methoxy acrylic acid, methyl maleic acid, dimethyl maleic acid, phenyl maleic acid, bromomaleic acid, chloromaleic acid, dichloromaleic acid, fluoromaleic acid, difluoromaleic acid, nonyl hydrogen maleate, decyl hydrogen maleate, dodecyl hydrogen maleate, stearyl hydrogen maleate, fluoralkyl hydrogen maleate, and combinations thereof.

8. The method of claim 1, wherein the carboxylic acid salt group containing monomer is selected from the group consisting of acrylic acid salt, methacrylic acid salt, crotonic acid salt, 2-butyl crotonic acid salt, cinnamic acid salt, maleic acid salt, maleic anhydride salt, fumaric acid salt, itaconic acid salt, itaconic anhydride salt, 4,4-dimethyl itaconic acid salt, 2-ethyl acrylic acid salt, isocrotonic acid salt, cis-2-pentenoic acid salt, trans-2-pentenoic acid salt, angelic acid salt, tiglic acid salt, 3,3-dimethyl acrylic acid salt, 3-propyl acrylic acid salt, trans-2-methyl-3-ethyl acrylic acid salt, cis-2-methyl-3-ethyl acrylic acid salt, 3-isopropyl acrylic acid salt, trans-3-methyl-3-ethyl acrylic acid salt, cis-3-methyl-3-ethyl acrylic acid salt, 2-isopropyl acrylic acid salt, trimethyl acrylic acid salt, 2-methyl-3,3-diethyl acrylic acid salt, 3-butyl acrylic acid salt, 2-butyl acrylic acid salt, 2-pentyl acrylic acid salt, 2-methyl-2-hexenoic acid salt, trans-3-methyl-2-hexenoic acid salt, 3-methyl-3-propyl acrylic acid salt, 2-ethyl-3-propyl acrylic acid salt, 2,3-diethyl acrylic acid salt, 3,3-diethyl acrylic acid salt, 3-methyl-3-hexyl acrylic acid salt, 3-methyl-3-t-butyl acrylic acid salt, 2-methyl-3-pentyl acrylic acid salt, 3-methyl-3-pentyl acrylic acid salt, 4-methyl-2-hexenoic acid salt, 4-ethyl-2-hexenoic acid salt, 3-methyl-2-ethyl-2-hexenoic acid salt, 3-t-butyl acrylic acid salt, 2,3-dimethyl-3-ethyl acrylic acid salt, 3,3-dimethyl-2-ethyl acrylic acid salt, 3-methyl-3-isopropyl acrylic acid salt, 2-methyl-3-isopropyl acrylic acid salt, trans-2-octenoic acid salt, cis-2-octenoic acid salt, trans-2-decenoic acid salt, a-acetoxy acrylic acid salt, β-trans-aryloxy acrylic acid salt, a-chloro-β-E-methoxy acrylic acid salt, methyl maleic acid salt, dimethyl maleic acid salt, phenyl maleic acid salt, bromomaleic acid salt, chloromaleic acid salt, dichloromaleic acid salt, fluoromaleic acid salt, difluoromaleic acid salt, and combinations thereof.

9. The method of claim 1, wherein the sulfonic acid group containing monomer is selected from the group consisting of vinyl sulfonic acid, methyl vinyl sulfonic acid, allyl vinyl sulfonic acid, allyl sulfonic acid, methyl allyl sulfonic acid, styrene sulfonic acid, 2-sulfoethyl methacrylic acid, 2-methyl-2-propene-1-sulfonic acid, 2-acrylamido-2-methyl-1-propane sulfonic acid, 3-allyloxy-2-hydroxy-1-propane sulfonic acid, and combinations thereof.

10. The method of claim 1, wherein the sulfonic acid salt group containing monomer is selected from the group consisting of vinyl sulfonic acid salt, methyl vinyl sulfonic acid salt, allyl vinyl sulfonic acid salt, allyl sulfonic acid salt, methyl allyl sulfonic acid salt, styrene sulfonic acid salt, 2-sulfoethyl methacrylic acid salt, 2-methyl-2-propene-1-sulfonic acid salt, 2-acrylamido-2-methyl-1-propane sulfonic acid salt, 3-allyloxy-2-hydroxy-1-propane sulfonic acid salt, and combinations thereof.

11. The method of claim 1, wherein the monomer containing phosphonic acid group is selected from the group consisting of vinyl phosphonic acid, allyl phosphonic acid, vinyl benzyl phosphonic acid, acrylamidoalkyl phosphonic acid, methacrylamidoalkyl phosphonic acid, acrylamidoalkyl diphosphonic acid, acryloyl phosphonic acid, 2-methacryloyloxyethyl phosphonic acid, bis(2-methacryloyloxyethyl) phosphonic acid, ethylene 2-methacryloyloxyethyl phosphonic acid, ethyl-methacryloyloxyethyl phosphonic acid, and combinations thereof.

12. The method of claim 1, wherein the monomer containing phosphonate group is selected from the group consisting of vinyl phosphonate, allyl phosphonate, vinyl benzyl phosphonate, acrylamidoalkyl phosphonate, methacrylamidoalkyl phosphonate, acrylamidoalkyl diphosphonate, acryloyl phosphonate, 2-methacryloyloxyethyl phosphonate, bis(2-methacryloyloxyethyl) phosphonate, ethylene 2-methacryloyloxyethyl phosphonate, ethyl-methacryloyloxyethyl phosphonate, and combinations thereof.

13. The method of claim 1, wherein the structural unit (b) is derived from a monomer selected from a monomer containing an amide group.

14. The method of claim 1, wherein the structural unit (b) in the copolymer binder is present in a proportion of 5 to 35% by mole, based on the total number of moles of monomeric units in the copolymer binder.

15. The method of claim 13, wherein the monomer containing an amide group is selected from the group consisting of acrylamide, methacrylamide, N-methyl methacrylamide, N-ethyl methacrylamide, N-n-propyl methacrylamide, N-isopropyl methacrylamide, isopropyl acrylamide, N-n-butyl methacrylamide, N-isobutyl methacrylamide, N,N-dimethyl acrylamide, N,N-dimethyl methacrylamide, N,N-diethyl acrylamide, N,N-diethyl methacrylamide, N-hydroxymethyl methacrylamide, N-(methoxymethyl) methacrylamide, N-(ethoxymethyl) methacrylamide, N-(propoxymethyl) methacrylamide, N-(butoxymethyl) methacrylamide, N-(3-(dimethylamino)propyl) methacrylamide, N-(2-(dimethylamino)ethyl) methacrylamide, N,N-(dihydroxymethyl) methacrylamide, diketone methacrylamide, diketone acrylamide, methacryloyl morpholine, N-hydroxymethyl acrylamide, N-methoxymethyl acrylamide, N-methoxymethyl methacrylamide, N,N'-methylenebisacrylamide (MBA), N-hydroxymethyl acrylamide, and combinations thereof.

16. The method of claim 1 or 13, wherein the structural unit (c) is derived from a monomer selected from a monomer containing a nitrile group.

17. The method of claim 1, wherein the structural unit (c) in the copolymer binder is present in a proportion of 15 to 75% by mole, based on the total number of moles of monomeric units in the copolymer binder.

18. The method of claim 16, wherein the monomer comprising a nitrile group is selected from the group consisting of acrylonitrile, a-halogenated acrylonitrile, a-alkyl acrylonitrile, a-chloroacrylonitrile, a-bromoacrylonitrile, a-fluoroacrylonitrile, methacrylonitrile, a-ethylacrylonitrile, a-isopropylacrylonitrile, a-n-hexylacrylonitrile, a-methoxyacrylonitrile, 3-methoxyacrylonitrile, 3-ethoxyacrylonitrile, a-acetoxyacrylonitrile, a-phenylacrylonitrile, a-tolylacrylonitrile, a-(methoxyphenyl)acrylonitrile, a-(chlorophenyl)acrylonitrile, a-(cyanophenyl)acrylonitrile, vinylidene cyanide, and combinations thereof.

19. The method of claim 1, wherein the metal substrate is in the form of a foil, a sheet, a film, or a combination thereof, and wherein the metal substrate is selected from the group consisting of titanium, nickel, aluminum, copper, platinum, gold, silver, chromium, zirconium, tungsten, molybdenum, tin, vanadium, zinc, cadmium, iron, cobalt, lead, and alloys thereof.

20. The method of claim 1, wherein the metal substrate is in the form of a porous body having a three-dimensional network structure, wherein the metal substrate is selected from the group consisting of titanium, nickel, aluminum, copper, platinum, gold, silver, chromium, zirconium, tungsten, molybdenum, tin, vanadium, zinc, cadmium, iron, cobalt, lead, and alloys thereof.

21. The method of claim 1, wherein the weight ratio of the composite to the peeling solution is from 0.01% to 50%, and wherein the temperature at which the composite is immersed in the peeling solution is from 10 °C to 90 °C.

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