Exfoliation method of the complex

Abstract

This document provides a method for peeling a composite by immersing it 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 polymer binder, and wherein the polymer binder comprises an aqueous copolymer. Using a stripping solution containing a strong alkali allows for complete peeling of the composite in a highly efficient and extremely fast manner. Furthermore, the stripping method disclosed herein avoids complex separation processes, contamination and corrosion of the metal substrate, and enables excellent material recovery. This document also discloses an application of a method for stripping electrodes from a battery.

Description

Technical Field

[0001] This invention relates to the field of material recycling methods. Specifically, this invention relates to a method for stripping a composite comprising a metal substrate and a coating applied to one or both sides of the metal substrate. Background Technology

[0002] Increasing urbanization, rapid technological innovation, and the resulting frequent product replacements or disposal of obsolete consumables have led to shortened product lifespans and / or overproduction of waste. With the emergence of increasingly serious problems related to waste overproduction, such as harmful effects on human health, adverse environmental impacts, and resource depletion, there is an urgent need worldwide to take swift action to address these complex issues using various waste management methods.

[0003] Recycling, as a key component of the waste reduction hierarchy, aims to recover usable materials from waste for reuse. The recycling of materials can protect natural resources, reduce energy consumption (and resulting production costs) associated with raw material extraction, and reduce greenhouse gases and SO2 emissions. x This reduces emissions and environmental impact. Because material recycling can bring significant benefits, developing efficient material recycling methods is crucial for achieving a circular economy.

[0004] The term "composite" refers to a metal substrate to which a coating is applied on one or both sides, wherein the coating contains a polymer binder. The polymer binder is responsible for the adhesion between the coating and the metal substrate. Applying a coating to a metal substrate is a method of altering surface properties to meet performance requirements in various technical applications. Some applications of coatings include binders, barrier layer formation, scratch and abrasion resistance, chemical resistance, wettability, and biocompatibility. Coating metal substrates is frequently used in battery fabrication, membrane technology, packaging materials, circuit board printing, wires or cables, and biomedical applications. Therefore, separating the coating from the metal substrate is a widely used technique in material recycling.

[0005] However, for products that have reached the end of their service life or product waste that can be immediately recycled during the production process, there are some difficulties in separating the complexes contained in the product into coatings and metal substrates during the recycling process.

[0006] On the one hand, the peeling of the composite may occur within the coating's surface rather than at the coating-metal substrate interface. Consequently, the coating cannot be completely peeled off from the metal substrate, leaving a portion intact. This results in undesirable loss of coating material due to the inability to directly recover it from the peeling process, and the recovered metal substrate contains high levels of impurities due to the presence of residual coating, necessitating subsequent separation processes.

[0007] On the other hand, peeling the coating off the metal substrate can be very inefficient, sometimes taking several hours. Exposing the composite to harsh peeling conditions for extended periods can likely cause side effects, such as corrosion, dissolution, and damage to the materials within the composite (especially the metal substrate), as well as the generation of byproducts.

[0008] Polymer binders commonly used to bond coatings to metal substrates, such as polyvinylidene fluoride (PVDF), have drawbacks. They are insoluble in water, and in fact, these polymers are only soluble in certain 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 NMP vapors. This incurs significant costs in the manufacturing process, as establishing such a system requires substantial capital investment. Therefore, for applications where exposure to a humid environment during manufacturing is not a critical issue, this invention preferably uses polymer binders with cheaper and more environmentally friendly solvents (e.g., aqueous solvents, most commonly water), as this reduces the substantial capital cost of recovery systems.

[0009] Polymer binders suitable for water-based coatings exhibit excellent dispersibility and stability in water and promote extremely strong coating-metal substrate adhesion. However, it is precisely this strong coating-metal substrate adhesion that makes peeling the water-based coating from the attached metal substrate a significant challenge. To better optimize the performance of these water-based binders, copolymers containing structural units derived from various monomers can be used, but peeling still presents considerable challenges when these copolymer binders are used for coatings.

[0010] The peeling of the composite is achieved by breaking and / or cleaving the bonds between the polymer binder within the coating and the metal substrate at the coating-metal substrate interface. Therefore, an important objective is to more efficiently break and / or cleave the bonds between the polymer binder within the coating and the metal substrate to achieve high-speed, high-recovery, and high-safety peeling with lower amounts of additional materials and lower costs.

[0011] Methods for achieving complete separation of composites have been attempted. Korean Patent Application Publication No. 20130099568A discloses a method for separating a composite containing a polymer film coated on a metal surface by using electromagnetic induction to carbonize the polymer. The method involves a pretreatment step where the metal-polymer composite is placed in an induction furnace to receive maximum influence from the magnetic density per unit area during induction heating, making electron movement on the metal surface more active. Through induction heating, the metal-polymer composite is heated to 500-900°C, which weakens the adhesion between the polymer and the metal surface, subsequently leading to thermal decomposition and carbonization of the polymer coated on the metal surface, thus facilitating separation. This method significantly saves energy by employing induction heating. However, the proposed method results in polymer carbonization, making polymer recycling impossible. Furthermore, harmful or toxic pollutants may be generated during polymer decomposition.

[0012] Given the aforementioned challenges, there is a persistent need to develop a unified and simple method for the efficient and complete exfoliation of composites at the coating-metal substrate interface, where the coating of the composite contains a polymer binder, and where the polymer binder is a copolymer. The exfoliation method disclosed herein aims to achieve the effective disruption and / or cleavage of the bonds between the copolymer binder and the metal substrate in the composite coating. Therefore, an exfoliation method meeting these characteristics can be applied to composites containing copolymer binders. This method avoids complex separation processes and metal substrate contamination, achieves excellent material recovery rates, and allows for rapid exfoliation of the composite. Summary of the Invention

[0013] The aforementioned needs can be met through the various aspects and embodiments disclosed herein. In one aspect, this document provides a method for peeling a composite by immersing it in a peeling 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 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 a base. In some embodiments, the base is selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, lithium oxide, sodium oxide, potassium oxide, rubidium oxide, cesium oxide, calcium oxide, strontium oxide, barium oxide, and combinations thereof.

[0017] The method described herein enables rapid and simple peeling of the composite without causing adverse effects such as loss of unrecoverable coating material, damage to the coating material, or introduction of impurities into the metal substrate.

[0018] On the other hand, as one application of the present invention, the above method can be used for the peeling of battery electrodes, wherein the composite is the battery electrode, the metal substrate is the current collector, and the coating is the electrode layer. This document provides a method for peeling battery electrodes by immersing them in a peeling 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] This invention utilizes a stripping solution to strip the battery electrodes at the electrode layer-current collector interface, significantly reducing the time required for complete stripping, maximizing the recovery of useful materials, eliminating current collector contamination, and eliminating the need for subsequent processes. Furthermore, the method disclosed herein has been found to be applicable to the stripping of both the cathode and anode without causing corrosion to the current collector and / or the electrode active materials within the electrode layer. Attached Figure Description

[0020] Figure 1 A simplified view showing one embodiment of the compound.

[0021] Figure 2 This diagram shows the coating-metal substrate interface structure in the proposed composite.

[0022] Figure 3 This is a flowchart of an implementation method, showing the steps of the composite stripping disclosed herein and the subsequent further processing for extracting the composite components (i.e., the coating and the metal substrate) after composite stripping.

[0023] Figure 4 The cathode layer and current collector recovered in Example 2 after immersing the double-sided coated cathode in a stripping solution, wherein the stripping solution contains 0.1M sodium hydroxide and deionized water, and wherein the double-sided cathode contains a copolymer binder.

[0024] Figure 5 The recovered cathode of Comparative Example 1 is shown, wherein the stripping solution contains 0.1 M sodium hydroxide and deionized water, and wherein the double-coated cathode contains polyvinylidene fluoride (PVDF) as a polymer binder. Detailed Implementation

[0025] On the one hand, this article provides a method for peeling a composite by immersing it in a peeling 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 copolymer binder.

[0026] On the other hand, this article provides a method for peeling off a lithium-ion battery electrode by immersing it 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.

[0027] The term "electrode" refers to either "cathode" or "anode".

[0028] The terms "positive electrode" and "cathode" are used interchangeably. Similarly, the terms "negative electrode" and "anode" are used interchangeably.

[0029] The term "binder" or "binder material" refers to a chemical compound, mixture of compounds, or polymer used to hold materials in place and adhere them 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 hold electrode materials and / or conductive agents in place and adhere them to a conductive metal component to form an electrode. In some embodiments, the electrode does not contain any conductive agent.

[0030] The term "conductive agent" refers to a material with good electrical conductivity. Therefore, conductive agents are typically mixed with electrode active materials during electrode formation to improve the electrode's conductivity. In some embodiments, the conductive agent is chemically active. In some embodiments, the conductive agent is chemically inert.

[0031] The term "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. In the context of composite, the term "component" refers to both the metal substrate and the coating.

[0032] The term "polymer" refers to a compound prepared by polymerizing the same or different types of monomers. The general term "polymer" includes the terms "homopolymer" and "copolymer".

[0033] The term "aqueous polymer" refers to a polymer that can be dispersed in an aqueous solvent (such as water) to form a solution or colloidal system, wherein the polymer in the colloidal system does not readily self-aggregate.

[0034] The term "homogeneous polymer" refers to a polymer prepared by polymerizing the same type of monomers.

[0035] The term "copolymer" refers to a polymer prepared by polymerizing two or more different types of monomers.

[0036] The term "polymer adhesive" refers to an adhesive that has polymeric properties. The term "copolymer adhesive" refers to a polymer adhesive, specifically a copolymer.

[0037] As used in this article, the term "unsaturated" refers to a moiety that has one or more unsaturated units.

[0038] The term "alkyl" or "alkyl group" refers to a group having the general formula C n H 2n+1 The monovalent group is derived from a saturated, unbranched or branched aliphatic hydrocarbon by removing a hydrogen atom, where 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, (C1–C8) alkyl groups, such as methyl, ethyl, propyl, isopropyl, 2-methyl-1-propyl, 2-methyl-2-propyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-3-butyl, 2,2-dimethyl-1-propyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl, 2,2-dimethyl-1-butyl, 3,3-dimethyl-1-butyl, 2-ethyl-1-butyl, butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, heptyl, and octyl. Longer alkyl groups include nonyl and decyl groups. Alkyl groups may be unsubstituted or substituted with one or more suitable substituents. Furthermore, alkyl groups may be branched or unbranched. In some embodiments, the alkyl group contains at least 2, 3, 4, 5, 6, 7 or 8 carbon atoms.

[0039] The term "cycloalkyl" or "cycloalkyl group" refers to a saturated or unsaturated cyclic non-aromatic hydrocarbon group having a monocyclic or multiple fused rings. Examples of cycloalkyl groups include, but are not limited to, (C3-C7) cycloalkyl groups, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl; (C3-C7) cycloalkenyl groups, such as cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, and cycloheptenyl; and cyclic terpenes and bicyclic terpenes. The cycloalkyl group may be unsubstituted or substituted with one or two suitable substituents. Furthermore, the cycloalkyl group may be monocyclic or polycyclic. In some embodiments, the cycloalkyl group contains at least 5, 6, 7, 8, 9, or 10 carbon atoms.

[0040] The term "alkoxy" refers to an alkyl group as defined above, connected to the main carbon chain via an oxygen atom. Some non-limiting examples of alkoxy groups include methoxy, ethoxy, propoxy, butoxy, etc. Furthermore, the alkoxy group defined above can be substituted or unsubstituted, wherein the substituent can be, but is not limited to, deuterium, hydroxyl, amino, halogen, cyano, alkoxy, alkyl, alkenyl, alkynyl, mercapto, nitro, etc.

[0041] 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, vinyl, 1-propenyl, and 2-propenyl groups, which may optionally be substituted on one or more carbon atoms of the group.

[0042] The term "aryl" or "aryl group" refers to an organic group derived from a monocyclic or polycyclic aromatic hydrocarbon by removing one hydrogen atom. Non-limiting examples of aryl groups include phenyl, naphthyl, benzyl, tolanyl, sexiphenyl, phenanthrenyl, anthraceneyl, coronenyl, and tolanylphenyl. The aryl group may be unsubstituted or substituted with one or more suitable substituents. Furthermore, the aryl group may be monocyclic or polycyclic. In some embodiments, the aryl group contains at least 6, 7, 8, 9, or 10 carbon atoms.

[0043] The term "aliphatic" refers to C1 to C2. 30 alkyl groups, C2 to C 30 alkenyl groups, C2 to C 30 alkynyl group, C1 to C 30 alkylene groups, C2 to C 30 imide groups or C2 to C 30 The alkyl group contains an alkylene group. In some embodiments, the alkyl group contains at least 2, 3, 4, 5, 6, 7 or 8 carbon atoms.

[0044] The term "aromatic" refers to a group comprising an aromatic hydrocarbon ring, optionally including 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, pyrene, triphenylene and their derivatives.

[0045] The term "substituted" used to describe a compound or chemical moiety means that at least one hydrogen atom of the compound or chemical moiety is replaced by another chemical moiety. Examples of substituents include, but are not limited to, halogens; alkyl groups; heteroalkyl groups; alkenyl groups; alkynyl groups; heteroaryl groups; hydroxyl groups; alkoxy groups; amino groups; nitro groups; mercapto groups; thioether groups; imino groups; cyano groups; amide groups; phosphono acid groups; hypophosphono acid groups; carboxyl groups; thiocarbonyl groups; sulfonyl groups; sulfonamide groups; acyl groups; formyl groups; acyloxy groups; alkoxycarbonyl groups; carbonyl groups; haloalkyl groups (e.g., trifluoromethyl groups); carbocyclic cycloalkyl groups, which may be monocyclic or fused or unfused polycyclic (e.g., cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl) or heterocyclic alkyl groups, which may be monocyclic or fused or unfused polycyclic (e.g., pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, or thiazinyl); carbocyclic or heterocyclic, monocyclic or fused or unfused polycyclic aryl groups (e.g., phenyl, naphthyl, pyrrolidinyl, indoleyl, furanyl, thiophenyl). iophenyl), imidazolyl, oxazolyl, isoxazolyl, thiazolyl, triazolyl, tetrazolyl, pyrazolyl, pyridinyl, quinolinyl, isoquinolinyl, acridineyl, pyrazinyl, pyridazinyl, pyrimidinyl, benzimidazolyl, benzothiophene, or benzofuranyl); amino (primary, secondary, or tertiary amine); ortho-lower alkyl; ortho-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 may optionally be substituted with fused ring structures or bridging structures (e.g., -OCH2O-). These substituents may optionally be further substituted with substituents selected from these groups. Unless otherwise specified, all chemical groups disclosed herein may be substituted.

[0046] The term "halogen" or "halogenated" refers to F, Cl, Br, or I.

[0047] The term "monomer unit" refers to the building block of a polymer provided by a single monomer.

[0048] The term "structural unit" refers to a total monomer unit provided by the same monomer type in a polymer.

[0049] The term "acid salt group" refers to an acid salt formed when an acid reacts with a base. In some embodiments, the protons of the acid are replaced by metal cations. In some embodiments, the protons of the acid are replaced by ammonium ions.

[0050] The term "planetary mixer" refers to a device used to mix or agitate different materials to produce a homogeneous mixture, which consists of paddles undergoing planetary motion within a container. In some embodiments, the planetary mixer comprises 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 about the container. Rotational speed can be expressed in revolutions per minute (rpm), which refers to the number of revolutions completed by the rotating body in one minute.

[0051] The term "ultrasonic generator" refers to a device capable of agitating particles in a sample using ultrasonic energy. Any ultrasonic generator capable of dispersing the slurry disclosed herein may be used. Some non-limiting examples of ultrasonic generators include ultrasonic baths, probe-type ultrasonic generators, and ultrasonic flow cells.

[0052] The term "ultrasonic bath" refers to a device that transmits ultrasonic energy through the walls of an ultrasonic bath container to a liquid sample.

[0053] The term "probe-type ultrasonic generator" refers to an ultrasonic probe immersed in a medium for direct ultrasonic processing. The term "direct ultrasonic processing" refers to ultrasonic waves being directly coupled into the processing liquid.

[0054] The terms "ultrasonic flow cell" or "ultrasonic reactor chamber" refer to a device that performs ultrasonic treatment in a flow mode. In some embodiments, the ultrasonic flow cell is a single-channel, multi-channel, or recirculation configuration.

[0055] The term "apply" refers to the action of laying or spreading a substance on a surface.

[0056] The term "current collector" refers to any conductive layer that is in contact with the electrode layer and capable of conducting current to the electrode during the discharge or charging of the secondary battery. Some non-limiting examples of current collectors include a single conductive metal layer or substrate, as well as a single conductive metal layer or substrate covered with a conductive coating (e.g., a carbon black-based coating). The conductive metal layer or substrate can be in the form of a foil or a porous body with a three-dimensional network structure. In some embodiments, the three-dimensional porous current collector is coated with a conformal carbon layer.

[0057] The term "electrode layer" refers to a coating containing electrochemically active material that is in contact with the current collector. In some embodiments, the electrode layer is formed by applying a coating to the current collector. In some embodiments, the electrode layer is located on one or both sides of the current collector. In other embodiments, a three-dimensional porous current collector is covered with a conformal electrode layer. Thus, the electrode is a composite material in which the current collector is a metal substrate and the electrode layer is a coating.

[0058] The term "room temperature" refers to an indoor temperature of approximately 18°C ​​to approximately 30°C, such as 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 approximately 20°C + / - 1°C, + / - 2°C, or + / - 3°C. In other embodiments, room temperature refers to a temperature of approximately 22°C or approximately 25°C.

[0059] The term "solid content" refers to the amount of non-volatile substances remaining after evaporation.

[0060] The term "peel strength" refers to the magnitude of the force required to separate the current collector and electrode active material coatings that are bonded together. It is a measure of the adhesive strength between the two materials and is typically expressed in N / cm.

[0061] The term "adhesion strength" refers to the magnitude of the force required to separate a current collector and a polymer adhesive coating that are bonded together. It is a measure of the adhesive strength between the two materials and is typically expressed in N / cm.

[0062] The term "C-rate" refers to the charging or discharging rate of a battery, expressed in ampere-hours (Ah) or milliampere-hours (mAh), based on its total storage capacity. For example, a 1C rate means utilizing all the stored energy in one hour; 0.1C means utilizing 10% of the energy in one hour or all the energy in 10 hours; and 5C means utilizing all the energy in 12 minutes.

[0063] The term "ampere-hour (Ah)" refers to the unit used to describe the storage capacity of a battery. For example, a 1Ah battery can provide 1 ampere of current for one hour or 0.5 amperes of current for two hours. Therefore, 1 ampere-hour (Ah) is equivalent to 3,600 coulombs of charge. Similarly, the term "milliampere-hour (mAh)" also refers to the unit used to describe the storage capacity of a battery and is 1,000th the capacity of an ampere-hour.

[0064] The term "battery cycle life" refers to the number of full charge / discharge cycles a battery can perform before its nominal capacity drops below 80% of its initial rated capacity.

[0065] The term "capacity" is a characteristic of electrochemical cells, referring to the total amount of charge that an electrochemical cell (e.g., a battery) can hold. Capacity is usually expressed in ampere-hours (Ahs). The term "specific capacity" refers to the capacity output per unit weight of an electrochemical cell (e.g., a battery), usually expressed in Ah / kg or mAh / g.

[0066] 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.

[0067] In this specification, all instances of singular usage include instances of plural usage, and vice versa.

[0068] 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.

[0069] 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 preferably used 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 processing efficiency in terms of formation, storage, and utilization.

[0070] 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.

[0071] Typically, before a coating is applied to a metal substrate, the substrate is exposed to ambient air for a period of time. Ambient air mainly contains oxygen, water, and several organic and inorganic substances. When a metal substrate is exposed to naturally occurring oxygen in the atmosphere, metal oxides inevitably form on the substrate surface. For example, aluminum naturally reacts strongly with atmospheric oxygen, which can trigger the formation of aluminum oxide on the exposed aluminum surface. Aluminum oxide protects the internal aluminum from further oxidation, thus giving aluminum good corrosion resistance. When the metal oxides on the substrate surface come into contact with moisture in the ambient air, the metal oxides undergo hydroxylation, enriching the surface with hydroxyl groups (-OH).

[0072] The hydroxyl group on the metal substrate surface consists of a H atom covalently bonded to a more electronegative O atom and an electronegative O atom with a lone pair of electrons in its outermost electron shell. Within the hydroxyl group, a hydrogen atom can form a hydrogen bond with another molecule containing a highly electronegative atom (e.g., O, N, or F), and an oxygen atom can accept a hydrogen bond from a hydrogen atom in another molecule similarly bonded to a highly electronegative atom (e.g., O, N, or F).

[0073] Meanwhile, the metallic portion of the substrate still consists of a partially positively charged metallic material (M). δ+ It exists in the form of metal oxides formed on the surface of a metal substrate.

[0074] Figure 2 This diagram shows the coating-metal substrate interface structure of the proposed composite, indicated by 200. Hydroxyl (-OH) groups, partially positively charged metal (M) δ+ Both oxygen (O) atoms of the metal oxide and the metal substrate 201 are present on the surface of the metal substrate 201. The copolymer binder within and / or on the surface of the coating 202 comprises structural units derived from monomers containing carboxylic acid groups. In this case, the structural units derived from the monomers containing carboxylic acid groups comprise carboxylate groups, wherein the carboxylate groups are salts of carboxylic acid groups.

[0075] The oxygen (O) and hydrogen (H) atoms present in the copolymer binder may interact with the O and / or H atoms of the hydroxyl groups on the metal substrate surface and the O atoms in the metal oxide through hydrogen bonding. Furthermore, the anions of the carboxylate groups contained in the copolymer binder (COO in this case) - M with the surface of the metal substrate δ+ Ion-dipole interactions occur between the materials. Therefore, hydrogen bonds and / or ion-dipole attraction are formed between the coating and the metal substrate, and both types of interactions contribute significantly to the adhesion of the coating to the metal substrate surface.

[0076] The copolymer binders disclosed herein are formulated to provide extremely strong coating-metal substrate adhesion for a variety of applications. However, when products containing the composite reach the end of their practicality or service life, or when defective products are generated during the manufacturing process, this strong adhesion presents additional challenges in the subsequent recycling process as the coating separates from the metal substrate to which it is attached.

[0077] The peeling of a coating from a metal substrate in a composite is achieved by breaking and / or cleaving the bonds between the copolymer binder in the coating and the surface of the metal substrate. Copolymers with different components exhibiting different specific properties require different methods to separate the coating from the metal substrate. Therefore, the method of the present invention is specifically developed to peel the composite by breaking and / or cleaving the bonds between the aqueous copolymer binder disclosed herein and the surface of the metal substrate.

[0078] The present invention provides a method for peeling a composite by immersing it in a peeling 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 copolymer binder.

[0079] In some implementations, the peeling of the composite occurs at the coating-metal substrate interface.

[0080] In some embodiments, the stripping solution comprises a stripping agent and an aqueous solvent. In some embodiments, the stripping agent is a water-soluble strong base. In some embodiments, the aqueous solvent consists of only water.

[0081] In the stripping solution, the strong base can be an oxide of an alkali metal or an alkaline earth metal, a hydroxide of an alkali metal or an alkaline earth metal, or a combination thereof. In the case of a hydroxide, the strong base dissociates in an aqueous solvent, releasing the constituent ions of the strong base. In the case of an oxide, the oxide reacts with water, similarly forming ions.

[0082] These ions can enter the interface between the copolymer binder and the metal substrate surface. The ions disrupt the hydrogen bonds and ion-dipole interactions between the copolymer binder and the metal substrate. Aqueous solvents (such as water) present in the stripping solution also disrupt the ion-dipole interactions between the copolymer binder and the metal substrate surface in the coating. These aqueous solvent molecules further solvate the copolymer, forming a solvent shell (or a hydrated shell in the case of water), which significantly reduces the strength of the electrostatic interactions between the copolymer binder and the metal substrate in the coating.

[0083] In some embodiments, certain functional groups within the polymer are capable of dissociation in water; for example, carboxylic acid groups may not completely dissociate in water. A strong base further neutralizes the undissociated functional groups, forming corresponding anions, such as carboxylate anions when carboxylic acid functional groups are present. Water has a stronger attraction to such anions (e.g., carboxylate anions) than it does to undissociated functional groups. As these dissociable functional groups ionize, the solvation effect of the ionized functional groups in water becomes stronger, thus more effectively weakening the interaction between the polymer and the metal substrate. This, in turn, leads to coating peeling.

[0084] Therefore, the method disclosed herein aims to achieve the exfoliation of a composite material containing a copolymer binder by using an exfoliation solution to disrupt and / or break the hydrogen bonds and / or ion-dipole interactions between the coating and the metal substrate surface. This method is simple and does not require complex separation processes. The proposed method ensures complete exfoliation of the composite material at the coating-metal substrate interface without contaminating the metal substrate, thereby achieving excellent material recovery and enabling efficient and rapid exfoliation of the composite material.

[0085] Nonionic copolymer functional groups do not interact with the metal substrate surface through ion-dipole interactions. Using an aqueous solvent alone as a stripping solution may not be sufficient to completely peel the coating from the metal substrate because the solvation effect of the aqueous solvent on these nonionic copolymer functional groups is significantly lower; and the interactions (mainly hydrogen bonds) between these copolymer functional groups within the coating and the metal substrate surface are generally not disrupted or reduced to a degree that allows for complete peeling of the composite.

[0086] Therefore, both the stripping agent and the aqueous solvent should be used in combination as the stripping solution to achieve excellent complex stripping performance. In some embodiments, the stripping solution comprises both a stripping agent and an aqueous solvent.

[0087] In some embodiments, the stripping agent is a strong base. In some embodiments, the stripping agent is a hydroxide of an alkali metal or alkaline earth metal. In some embodiments, the stripping agent is an oxide of an alkali metal or alkaline earth metal. In some embodiments, the stripping agent is lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, lithium oxide, sodium oxide, potassium oxide, rubidium oxide, cesium oxide, calcium oxide, strontium oxide, barium oxide, or a combination thereof.

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

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

[0090] Non-limiting examples of water include tap water, bottled water, purified water, pure water, distilled water, deionized water, D2O, and combinations thereof. In some embodiments, the aqueous solvent is deionized water. Water may be used as part of the stripping solution to form a solvent shell around the copolymer binder of the coating and the metal substrate surface at the coating-metal substrate interface. This helps to disrupt the interaction between the copolymer binder in the coating and the metal substrate surface, thereby leading to complete stripping of the composite.

[0091] Any water-miscible or volatile solvent may be used as a minor component of the aqueous solvent (i.e., a solvent other than water). Some non-limiting examples of water-miscible or volatile solvents include alcohols, lower aliphatic ketones, lower alkyl acetates, and combinations thereof. The addition of alcohols can improve the solubility of the stripping agent and lower the freezing point of water. Some non-limiting examples of alcohols include C1-C4 alcohols, such as methanol, ethanol, isopropanol, n-propanol, tert-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 contain alcohols, lower aliphatic ketones, lower alkyl acetates, or combinations thereof.

[0092] Surfactants are used as additives in stripping solutions to improve stripping efficiency. However, adding surfactants to the stripping solution introduces impurities into the resulting solution, leading to reduced product purity or requiring time and resources to develop separation systems to remove the surfactants. Furthermore, surfactant emissions are harmful to the environment, and some surfactants may also pose health risks. Therefore, in some embodiments, surfactants are not added to the stripping solution. In some embodiments, the stripping solution is free of cationic surfactants, anionic surfactants, nonionic surfactants, and amphoteric surfactants.

[0093] In some embodiments, the stripping solution does not contain fatty acid salts; alkyl sulfates; polyoxyalkylene alkyl ether acetates; alkylbenzene sulfonates; polyoxyalkylene alkyl ether sulfates; higher fatty acid amide sulfonates; N-acylsarcosine salts. Salts); alkyl phosphates; polyoxyalkylene alkyl ether phosphates; long-chain sulfosuccinates; long-chain N-acylglutamates; polymers and copolymers comprising acrylic acid, acid anhydrides, esters, vinyl monomers and / or olefins and their alkali metal salts, alkaline earth metal salts and / or ammonium salt derivatives; polycarboxylate salts; formalin condensates of naphthalene sulfonic acid; alkyl naphthalene sulfonic acid; alkyl naphthalene sulfonates; formalin condensates of acids and naphthalene sulfonates (e.g., their alkali metal salts, alkaline earth metal salts, ammonium salts or amine salts); melamine sulfonic acid; alkyl melamine sulfonic acid; formalin condensates of melamine sulfonic acid; formalin condensates of alkyl melamine sulfonic acid; alkali metal salts, alkaline earth metal salts, ammonium salts and amine salts of melamine sulfonic acid; lignin sulfonic acid; and anionic surfactants of alkali metal salts, alkaline earth metal salts, ammonium salts and amine salts of lignin sulfonic acid.

[0094] In some embodiments, the stripping solution does not contain cationic surfactants including alkyltrimethylammonium salts, such as stearyltrimethylammonium chloride, dodecyltrimethylammonium chloride and hexadecyltrimethylammonium bromide; dialkyldimethylammonium salts; trialkylmethylammonium salts; tetraalkylammonium salts; alkylamine salts; benzalkonium salts; alkylpyridinium salts; and imidazole salts.

[0095] In some embodiments, the stripping solution does not contain nonionic surfactants including alkyl ethers containing polyoxyalkylene oxides; polyoxyalkylene styrene phenyl ethers; polyols; ester compounds of monovalent fatty acids; polyoxyalkylene alkylphenyl ethers; polyoxyalkylene fatty acid ethers; polyoxyalkylene sorbitan fatty acid esters; glycerol fatty acid esters; polyoxyalkylene castor oil; polyoxyalkylene hydrogenated castor oil; polyoxyalkylene sorbitan fatty acid esters; polyglycerol fatty acid esters; alkylglycerol ethers; polyoxyalkylene cholesterol ethers; alkyl glycosides; sucrose fatty acid esters; polyoxyalkylene alkylamines; polyoxyethylene-polyoxypropylene block polymers; sorbitan fatty acid esters; and fatty acid alkylolamides.

[0096] In some embodiments, the stripping solution does not contain the following amphoteric surfactants: sodium salt of 2-undecyl-N,N-(hydroxyethylcarboxymethyl)-2-imidazoline, disodium salt of 2-cocoyl-2-imidazoline hydroxide-1-carboxyethyloxy; imidazoline-based amphoteric surfactants; 2-heptadecyl-N-carboxymethyl-N-hydroxyethylimidazoline betaine, lauryl dimethylaminoacetic acid betaine, alkyl betaine, amide betaine, sulfobetaine and other betaine-based amphoteric surfactants; N-laurylglycine, N-lauryl β-alanine, N-stearyl β-alanine, lauryl dimethylaminooxide, oleyl dimethylaminooxide, sodium lauryl glutamate, lauryl dimethylaminoacetic acid betaine, stearyl dimethylaminoacetic acid betaine, cocamidopropyl hydroxysulfobetaine and 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazoline betaine.

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

[0098] In some embodiments, the coating comprises 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 comprises an aqueous copolymer.

[0099] In some embodiments, the copolymer comprises a structural unit (a), wherein the structural unit (a) is derived from a monomer selected from the group consisting of monomers containing carboxylic acid groups, monomers containing carboxylate groups, monomers containing sulfonic acid groups, monomers containing sulfonate groups, monomers containing phosphonic acid groups, monomers containing phosphonate groups, and combinations thereof. In some embodiments, the acid salt group is a salt of an acid group. In some embodiments, the monomer containing the acid salt group comprises an alkali metal cation. Examples of alkali metals forming alkali metal cations include lithium, sodium, and potassium. In some embodiments, the monomer containing the acid salt group comprises an ammonium cation. In some embodiments, the structural unit (a) may be derived from a combination of a monomer containing a salt group and a monomer containing an acid group.

[0100] In some embodiments, the monomer containing a carboxylic acid group is acrylic acid, methacrylic acid, crotonic acid, 2-butylcrotonic acid, cinnamic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, 4,4-dimethylitaconic acid, or a combination thereof. In some embodiments, the monomer containing a carboxylic acid group is 2-ethylacrylic acid, isocrotonic acid, cis-2-pentenoic acid, trans-2-pentenoic acid, angelic acid, tiglic acid. (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-octenic acid, cis-2-octenic acid, trans-2-decenoic acid, α-acetoxyacrylic acid, β-trans-aryloxyacrylic acid, α-chloro-β-E-methoxyacrylic acid, or combinations thereof. In some embodiments, the monomer containing a carboxylic acid group is methylmaleic acid, dimethylmaleic acid, phenylmaleic acid, bromomaleic acid, chloromaleic acid, dichloromaleic acid, fluoromaleic acid, difluoromaleic acid, nonyl hydrogenmaleate, decyl hydrogen maleate, dodecyl hydrogen maleate, octadecyl hydrogen maleate, fluoroalkyl hydrogen maleate, or a combination thereof. In some embodiments, the monomer containing a carboxylic acid group is maleic anhydride, methylmaleic anhydride, dimethylmaleic anhydride, acrylic anhydride, methacrylic anhydride, methacrolein, methacryloyl chloride, methacryloyl fluoride, methacryloyl bromide, or a combination thereof.

[0101] In some embodiments, the monomer containing a carboxyl group is an acrylate, a methacrylate, a crotonate, a 2-butyl crotonate, a cinnamate, a maleate, a maleic anhydride, a fumarate, an itaconic acid salt, an itaconic anhydride, a 4,4-dimethyl itaconic acid salt, or a combination thereof. In some embodiments, the monomer containing a carboxyl group is 2-ethyl acrylate, isocrotonate, cis-2-pentenoate, trans-2-pentenoate, angelic acid salt, tigrinate, 3,3-dimethyl acrylate, 3-propyl acrylate, trans-2-methyl-3-ethyl acrylate, cis-2-methyl-3-ethyl acrylate, 3-isopropyl acrylate, trans-3-methyl-3-ethyl acrylate, cis-3-methyl-3-ethyl acrylate, 2-isopropyl acrylate, trimethyl acrylate, 2-methyl-3,3-diethyl acrylate, 3-butyl acrylate, 2-butyl acrylate, 2-pentyl acrylate, 2-methyl-2-hexenoate, trans-3-methyl-2-hexenoate, 3-methyl-3-propyl acrylate, 2-ethyl-3-propyl Acrylates, 2,3-diethylacrylate, 3,3-diethylacrylate, 3-methyl-3-hexylacrylate, 3-methyl-3-tert-butylacrylate, 2-methyl-3-pentylacrylate, 3-methyl-3-pentylacrylate, 4-methyl-2-hexenoate, 4-ethyl-2-hexenoate, 3-methyl-2-ethyl-2-hexenoate, 3-tert-butylacrylate, 2,3-dimethyl-3-ethylacrylate, 3,3-dimethyl-2-ethylacrylate, 3-methyl-3-isopropylacrylate, 2-methyl-3-isopropylacrylate, trans-2-octenate, cis-2-octenate, trans-2-decenoate, α-acetoxyacrylate, β-trans-aryloxyacrylate, α-chloro-β-E-methoxyacrylate, or combinations thereof. In some embodiments, the monomer containing a carboxylate group is methyl maleate, dimethyl maleate, phenyl maleate, bromomaleate, chloromaleate, dichloromaleate, fluoromaleate, difluoromaleate, or a combination thereof.

[0102] In some embodiments, the monomer containing a sulfonic acid group is vinyl sulfonic acid, methyl vinyl sulfonic acid, allyl vinyl sulfonic acid, allyl sulfonic acid, methyl allyl sulfonic acid, styrene sulfonic acid, 2-sulfoethyl methacrylate, 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, vinyl hydrogen sulfate, or combinations 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, ethyl-methacryloyloxyethylphosphonic 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 approximately 30% to 80%, approximately 35% to 80%, approximately 40% to 80%, approximately 45% to 80%, approximately 50% to 80%, approximately 55% to 80%, approximately 60% to 80%, approximately 65% ​​to 80%, approximately 30% to 75%, approximately 30% to 70%, approximately 35% to approximately 70%, about 40% to about 70%, about 45% to about 70%, about 50% to about 70%, about 55% to about 70%, about 60% to about 70%, about 35% to about 65%, about 40% to about 65%, about 45% to about 65%, about 50% to about 65%, about 55% to about 65%, about 40% to about 60%, about 45% to about 60%, about 50% to about 60%, about 40% to about 55%, or about 45% to about 55%.

[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%, or less than 35% 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 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%, greater than 65%, greater than 67.5%, greater than 70%, greater than 72.5%, or greater than 75% on a molar basis.

[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 groups 20Methacrylates 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 about 5% to about 35% on a molar basis, about 7.5% to about 35%, about 10% to about 35%, about 12.5% ​​to about 35%, about 15% to about 35%, about 17.5% to about 35%, about 20% to about 35%, about 22.5% to about 35%, about 25% to about 35%, about 27.5% to about 35%, about 30% to about 35%, about 10% to about 30%, about 12.5% ​​to about 30%, about 15% to about 30%, about 17.5% to about 30%, about 20% to about 30%, about 22.5% to about 30%, about 25% to about 30%, about 10% to about 25%, about 12.5% ​​to about 25%, or about 15% to about 25%.

[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 32.5%, less than 30%, less than 27.5%, less than 25%, less than 22.5%, less than 20%, less than 17.5%, less than 15%, less than 12.5%, 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 7.5%, more than 10%, more than 12.5%, more than 15%, more than 17.5%, more than 20%, more than 22.5%, more than 25%, more than 27.5%, or more than 30% 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 dodecyl perfluoroacrylate, n-octyl perfluoroacrylate, n-butyl perfluoroacrylate, hexyl ethyl perfluoroacrylate, and octyl ethyl perfluoroacrylate; a perfluoroalkyl methacrylate, such as dodecyl perfluoromethacrylate, n-octyl perfluoromethacrylate, n-butyl perfluoromethacrylate, hexyl ethyl perfluoromethacrylate, and octyl ethyl perfluoromethacrylate; a perfluoroalkyl oxyacrylate, such as dodecyloxyethyl perfluoroacrylate and decyloxyethyl perfluoroacrylate; a perfluoroalkyl oxyacrylate, such as dodecyloxyethyl perfluoromethacrylate and decyloxyethyl perfluoromethacrylate, 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 about 10% to about 60%, about 10% to about 55%, about 10% to about 50%, about 10% to about 45%, about 10% to about 40%, about 10% to about 35%, about 10% to about 30%, about 15% to about 60%, about 15% to about 55%, about 15% to about 50%, about 15% to about 45%, about 15% to about 40%, about 15% to about 35%, about 15% to about 30%, about 20% to about 50%, about 20% to about 45%, about 20% to about 40%, about 20% to about 35%, or about 20% to about 30% on a molar basis.

[0120] 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 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%, less than 22.5%, less than 20%, less than 17.5%, or less than 15% 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 10%, greater than 12.5%, 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 52.5%, or greater than 55% 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, norbornadiene, 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, and 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 carbon-containing material. This carbon-containing material is part of the coating. In some embodiments, the metal substrate is not coated with a carbon-containing 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., a strong alkali) 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 that a significant portion of the coating will still be found adhering to or attached to the surface of the metal substrate. Using excessive stripping solution does not have particular disadvantages in terms of peeling effectiveness, but 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 off 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 0.05M to about 2M, about 0.1M to about 2M, about 0.15M to about 2M, about 0.2M to about 2M, about 0.25M to about 2M, about 0.3M to about 2M, about 0.4M to about 2M, about 0.5M to about 2M, about 0.05M to about 1M, about 0.1M to about 1M, about 0.15M to about 1M, about 0.2M to about 1M, about 0.25M to about 1M, about 0.3M to about 1M, about 0.4M to about 1M, about 0.5M to about 1M, about 0.05M to about 0.5M, about 0.1M to about 0.5M, about 0.15M to about 0.5M, about 0.2M to about 0.5M, or about 0.25M to about 0.5M.

[0138] In some embodiments, the concentration of the stripping agent in the stripping solution is 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 0.5M, less than 0.4M, less than 0.3M, or less than 0.25M. In some embodiments, the concentration of the stripping agent in the stripping solution is greater than 0.05M, greater than 0.1M, greater than 0.15M, greater than 0.2M, greater than 0.25M, greater than 0.3M, greater than 0.4M, greater than 0.5M, greater than 0.6M, greater than 0.8M, greater than 1M, or greater than 1.2M.

[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 2 Approximately 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 / 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 / cm2 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 / cm 2 Approximately 20 mg / cm 2 Approximately 10 mg / cm 2 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 / cm 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 / cm2 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 / cm3 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 1.5g / 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 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 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 / cm3 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 10 to about 14, about 10.25 to about 14, about 10.5 to about 14, about 10.75 to about 14, about 11 to about 14, about 11.25 to about 14, about 11.5 to about 14, about 11.5 to about 13.75, about 11.5 to about 13.5, about 11.5 to about 13.25, about 11.5 to about 13, about 11.5 to about 12.75, or about 11.5 to about 12.5.

[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 14, less than 13.75, less than 13.5, less than 13.25, less than 13, less than 12.75, less than 12.5, less than 12.25, less than 12, less than 11.75, or less than 11.5. In some embodiments, after immersing the complex in the stripping solution, the pH value of the resulting complex-stripping solution mixture is greater than 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 disclosed herein for composite stripping and subsequent further processes of extracting coating and metal substrate materials. Because the metal substrate in this invention has a relatively low tendency to corrode and dissolve, it is not necessary to purify the extracted stripping solution for further reuse. The extracted stripping solution can be reused for the stripping of 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 4The description describes the recovery of the cathode layer and current collector in Example 2 after immersing a double-coated cathode in a stripping solution, wherein the cathode contains a copolymer binder, and the stripping solution contains sodium hydroxide and deionized water at a concentration of 0.1 M. It is evident that the cathode layer completely peels off from the aluminum current collector, and no discoloration or pitting of the aluminum current collector is observed, indicating that there is 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 0.1 M sodium hydroxide 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 an electrochemical reaction from a cathode active material or to provide electrons required for an 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, where M is selected from the group consisting of Fe, Co, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, Si, Ge or combinations thereof. In some embodiments, the cathode active material is selected from the group consisting of LiFePO4, LiCoPO4, LiNiPO4, LiMnPO4, LiMnFePO4, LiMn x Fe (1-x) PO4 and combinations thereof; and 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 certain 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 certain 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 certain 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 certain 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, 0 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, and 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 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 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 embodiments, 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 12A 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 contain 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, zero-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 3.25 Ge 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 ;

[0189] 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);

[0190] 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.

[0191] 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.

[0192] 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.

[0193] 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.

[0194] 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.

[0195] 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.

[0196] 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 / cm 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 / 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 / cm 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 / cm 2 Approximately 15 mg / cm 2 or about 10mg / cm 2 Approximately 15 mg / cm 2 .

[0197] 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 .

[0198] 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 1.5g / cm 3 Approximately 2.5 g / cm³ 3 .

[0199] 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 .

[0200] 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 complex-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.

[0201] 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%.

[0202] 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%.

[0203] 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.

[0204] 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%.

[0205] 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%.

[0206] The method of the present invention achieves a 100% success rate in peeling electrodes containing copolymer binders, an extremely high recovery rate (>99%), and peels the electrode layer from the current collector in a short time (<60s).

[0207] 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:

[0208]

[0209] 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%.

[0210] 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.

[0211] 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).

[0212] 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 a strong alkali, the shorter contact time allows the natural oxide layer formed on the surface of the aluminum current collector to provide sufficient corrosion protection.

[0213] 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.

[0214] 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 a strong alkali. 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.

[0215] 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.

[0216] Example

[0217] The pH value of the electrode-stripping solution mixture after stripping was measured using an electrode-type pH meter (ION 2700, Eutech Instruments).

[0218] 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.

[0219] 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:

[0220]

[0221] 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.

[0222] 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.

[0223] 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.

[0224] Example 1

[0225] Assembly of pouch-type lithium-ion full batteries

[0226] A) Preparation of copolymer adhesives

[0227] 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.

[0228] 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.

[0229] 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.

[0230] 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.

[0231] 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.

[0232] 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 shown in Table 1 below.

[0233] B) Preparation of the positive electrode

[0234] A first mixture was prepared by dispersing 12 g of conductive agent (Super P; obtained from Timcal Ltd, Bodio, Switzerland) and 100 g of binder material (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.

[0235] 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 25°C and 1200 rpm for approximately 60 minutes to form a homogenized cathode slurry.

[0236] 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 .

[0237] C) Preparation of the negative electrode

[0238] A negative electrode slurry was prepared by mixing 93 wt.% graphite (BTR New Energy 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, NIPPON A&L, Japan) as a binder, 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 .

[0239] D) Assembly of pouch batteries

[0240] 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 a moisture and oxygen content of <1 ppm. After injecting the electrolyte, the pouch cells were vacuum-sealed and then mechanically pressurized using a standard-shaped stamping tool.

[0241] The assembled pouch cells were then subjected to repeated charge and discharge cycles at a constant current rate of 1C between 3.0V and 4.2V to simulate real-world usage. The actual battery capacity was approximately 5Ah. After 800 cycles, the nominal capacity dropped to less than 80% of its initial rated capacity.

[0242] Battery recycling

[0243] A) Discharging and removing pouch batteries

[0244] 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.

[0245] B) Preparation of the stripping solution

[0246] Add 2.00 g of anhydrous sodium hydroxide (Sigma-Aldrich, USA) to 1000 g of deionized water to form a stripping solution with a concentration of 0.05 M.

[0247] C) Immerse the cathode in the stripping solution.

[0248] 5.07 g of cathode was placed in a container containing 1000 g of stripping solution heated to 25 °C. The cathode layer separated from the aluminum foil. Once complete stripping of the cathode layer was observed, the stripping solution containing sodium hydroxide 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 99.56%. The stripping success rate and recovery rate of the stripped cathode material were measured and are shown in Table 1 below.

[0249] Assembly of pouch-type lithium-ion full batteries in Examples 2-4

[0250] 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.

[0251] Battery recycling in Example 2

[0252] A) Discharging and removing pouch batteries

[0253] The spent lithium-ion batteries were discharged and disassembled using the same method described in Example 1.

[0254] B) Preparation of the stripping solution

[0255] Add 4.00 g of anhydrous sodium hydroxide (Sigma-Aldrich, USA) to 1000 g of deionized water to form a stripping solution with a concentration of 0.10 M.

[0256] C) Immerse the cathode in the stripping solution.

[0257] 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 shown in Table 1 below.

[0258] Battery recycling in Example 3

[0259] A) Discharging and removing pouch batteries

[0260] The spent lithium-ion batteries were discharged and disassembled using the same method described in Example 1.

[0261] B) Preparation of the stripping solution

[0262] Add 8.00 g of anhydrous sodium hydroxide (Sigma-Aldrich, USA) to 1000 g of deionized water to form a stripping solution with a concentration of 0.20 M.

[0263] C) Immerse the cathode in the stripping solution.

[0264] 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 shown in Table 1 below.

[0265] Battery recycling in Example 4

[0266] A) Discharging and removing pouch batteries

[0267] The spent lithium-ion batteries were discharged and disassembled using the same method described in Example 1.

[0268] B) Preparation of the stripping solution

[0269] Add 20.0 g of anhydrous sodium hydroxide (Sigma-Aldrich, USA) to 1000 g of deionized water to form a stripping solution with a concentration of 0.50 M.

[0270] C) Immerse the cathode in the stripping solution.

[0271] 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 shown in Table 1 below.

[0272] Assembly of pouch-type lithium-ion full batteries in Examples 5-7

[0273] 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.

[0274] Battery recycling in Example 5

[0275] The battery was recovered using the same method as in Example 2, except that the stripping solution was heated to 50°C. The stripping success rate and recovery rate of the cathode material were measured and are shown in Table 1 below.

[0276] Battery recycling in Example 6

[0277] The battery was recovered using the same method as in Example 2, except that the stripping solution was heated to 90°C. The stripping success rate and recovery rate of the cathode material were measured and are shown in Table 1 below.

[0278] Battery recycling in Example 7

[0279] A) Discharging and removing pouch batteries

[0280] The spent lithium-ion batteries were discharged and disassembled using the same method described in Example 2.

[0281] B) Preparation of the stripping solution

[0282] Add 5.61 g of anhydrous potassium hydroxide (Sigma-Aldrich, USA) to 1000 g of deionized water to form a stripping solution with a concentration of 0.10 M.

[0283] C) Immerse the cathode in the stripping solution.

[0284] The cathode was immersed and stripped using the method described in Example 2, 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 shown in Table 1 below.

[0285] Preparation of the polymer adhesive in Example 8

[0286] A pouch-type lithium-ion battery was prepared using the method described in Example 2, except that 26.46 g of sodium hydroxide was added during the preparation of the first suspension, 51.02 g of acrylic acid was added during the preparation of the second suspension, 10.78 g of acrylamide was added during the preparation of the third suspension, and 8.05 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 2.

[0287] Preparation of the polymer adhesive in Example 9

[0288] A pouch-type lithium-ion battery was prepared using the method described in Example 2, except that 18.37 g of sodium hydroxide was added during the preparation of the first suspension, 36.44 g of acrylic acid was added during the preparation of the second suspension, 15.82 g of acrylamide was added during the preparation of the third suspension, and 15.03 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 2.

[0289] Preparation of the polymer binder in Example 10

[0290] A pouch-type lithium-ion battery was prepared using the method described in Example 2, except that 18.37 g of sodium hydroxide was added during the preparation of the first suspension, 36.44 g of acrylic acid was added during the preparation of the second suspension, 20.13 g of acrylamide was added during the preparation of the third suspension, and 11.81 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 2.

[0291] Assembly of pouch-type lithium-ion full batteries in Examples 8-10

[0292] A) Preparation of the positive electrode

[0293] The positive electrode was prepared by the method described in Example 2, except that the binder material prepared in Examples 8-10 was used to prepare the cathode of Examples 8-10 respectively.

[0294] B) Preparation of the negative electrode

[0295] The negative electrode was prepared using the method described in Example 2.

[0296] C) Assembly of pouch batteries

[0297] 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.

[0298] Assembly of a pouch-type lithium-ion full battery in Example 11

[0299] 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.

[0300] Assembly of a pouch-type lithium-ion full battery in Example 12

[0301] 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.

[0302] Assembly of a pouch-type lithium-ion full battery in Example 13

[0303] 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.

[0304] Assembly of a pouch-type lithium-ion full battery in Example 14

[0305] 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.

[0306] Battery recycling in Examples 8-14

[0307] 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 shown in Table 1 below.

[0308] Preparation of the polymer adhesive in Example 15

[0309] A pouch-type lithium-ion battery was prepared using the method described in Example 4, except that 10.68 g of sodium hydroxide was added during the preparation of the first suspension, 22.60 g of acrylic acid was added during the preparation of the second suspension, 6.47 g of acrylamide was added during the preparation of the third suspension, and 32.20 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 4.

[0310] Preparation of the polymer adhesive in Example 16

[0311] A pouch-type lithium-ion battery was prepared using the method described in Example 4, except that 14.32 g of sodium hydroxide was added during the preparation of the first suspension, 29.16 g of acrylic acid was added during the preparation of the second suspension, 12.22 g of acrylamide was added during the preparation of the third suspension, and 23.08 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 4.

[0312] Assembly of pouch-type lithium-ion full batteries in Examples 15-16

[0313] A) Preparation of the positive electrode

[0314] The positive electrode was prepared by the method described in Example 4, except that the binder material prepared in Examples 15-16 was used to prepare the cathode of Examples 15-16 respectively.

[0315] B) Preparation of the negative electrode

[0316] The negative electrode was prepared using the method described in Example 4.

[0317] C) Assembly of pouch batteries

[0318] A pouch-type lithium-ion battery was prepared using the method described in Example 4. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 4.

[0319] Battery recycling in Examples 15-16

[0320] 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 shown in Table 1 below.

[0321] Assembly of a pouch-type lithium-ion full battery in Comparative Example 1

[0322] A) Preparation of the positive electrode

[0323] 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 of N-methyl-2-pyrrolidone NMP (≥99%, Sigma-Aldrich, USA) and stirred at 500rpm for about 3 hours with a top-mounted stirrer to prepare the first suspension.

[0324] Subsequently, 15g of SuperP was added to the first suspension and stirred at 1200rpm for 30 minutes to obtain the second suspension.

[0325] 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.

[0326] A homogenized cathode paste was coated onto both sides of a 16 μm thick aluminum foil serving as a 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.

[0327] B) Preparation of the negative electrode

[0328] The negative electrode was prepared using the same method as in Example 2.

[0329] C) Assembly of pouch batteries

[0330] The pouch cell was assembled using the same method as in Example 2. The assembled pouch cell was then repeatedly cycled using the same method as in Example 2.

[0331] Battery recycling in Comparative Example 1

[0332] The battery was recovered using the same method as in Example 2, except that the reaction was terminated after ten minutes if the stripping was incomplete. The stripping success rate and recovery rate of the cathode material were measured and are shown in Table 2 below.

[0333] Assembly of a pouch-type lithium-ion full battery in Comparative Example 2

[0334] 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.

[0335] Battery recycling in Comparative Example 2

[0336] The battery was recovered using the same method as in Example 2, except that no stripping agent was added during the preparation of the stripping solution; only 1000g of deionized water was added. If stripping was incomplete, the reaction was terminated after ten minutes. The stripping success rate and recovery rate of the cathode material were measured and are shown in Table 2 below.

[0337] Assembly of a pouch-type lithium-ion full battery in Comparative Example 3

[0338] A pouch-type lithium-ion battery was prepared using the method described in Example 2, except that 7.45 g of sodium hydroxide was added during the preparation of the first suspension, 16.77 g of acrylic acid was added during the preparation of the second suspension, 7.19 g of acrylamide was added during the preparation of the third suspension, and 35.95 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 2.

[0339] Assembly of a pouch-type lithium-ion full battery in Comparative Example 4

[0340] A pouch-type lithium-ion battery was prepared using the method described in Example 2, except that 30.51 g of sodium hydroxide was added during the preparation of the first suspension, 58.31 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 10.73 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 2.

[0341] Assembly of a pouch-type lithium-ion full battery in Comparative Example 5

[0342] A pouch-type lithium-ion battery was prepared using the method described in Example 2, except that 24.44 g of sodium hydroxide was added during the preparation of the first suspension, 47.38 g of acrylic acid was added during the preparation of the second suspension, 25.16 g of acrylamide was added during the preparation of the third suspension, and no 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 2.

[0343] Assembly of a pouch-type lithium-ion full battery in Comparative Example 6

[0344] A pouch-type lithium-ion battery was prepared using the method described in Example 2, except that 16.35 g of sodium hydroxide was added during the preparation of the first suspension, 32.80 g of acrylic acid was added during the preparation of the second suspension, 28.76 g of acrylamide was added during the preparation of the third suspension, and 8.05 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 2.

[0345] Assembly of a pouch-type lithium-ion full battery in Comparative Example 7

[0346] A pouch-type lithium-ion battery was prepared using the method described in Example 2, except that 10.28 g of sodium hydroxide was added during the preparation of the first suspension, 21.87 g of acrylic acid was added during the preparation of the second suspension, 3.59 g of acrylamide was added during the preparation of the third suspension, and 34.89 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 2.

[0347] Assembly of a pouch-type lithium-ion full battery in Comparative Example 8

[0348] A pouch-type lithium-ion battery was prepared using the method described in Example 2, except that 4.21 g of sodium hydroxide was added during the preparation of the first suspension, 10.93 g of acrylic acid was added during the preparation of the second suspension, 21.57 g of acrylamide was added during the preparation of the third suspension, and 29.52 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 2.

[0349] Battery recycling in Comparative Examples 3-8

[0350] The battery was recovered using the same method as in Example 2, except that the reaction was terminated after ten minutes if the stripping was incomplete. The stripping success rate and recovery rate of the cathode material were measured and are shown in Table 2 below.

[0351]

[0352]

[0353] 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 for peeling a composite by immersing it in a stripping solution, wherein the stripping solution comprises a stripping agent and an aqueous solvent, the stripping agent being selected from water-soluble strong bases, 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 copolymer binder, and wherein the copolymer binder comprises a structural unit (a) derived from monomers selected from the group consisting of monomers containing carboxylic acid groups, monomers containing sulfonic acid groups, monomers containing phosphonic acid groups, monomers containing carboxyl salt groups, monomers containing sulfonate groups, monomers containing phosphonate groups, and combinations thereof, wherein the copolymer... The proportion of the structural unit (a) in the copolymer is 30% to 80% on a molar basis, wherein the copolymer further comprises a structural unit (b), wherein the structural unit (b) is derived from monomers selected from the group consisting of monomers containing amide groups, monomers containing hydroxyl groups, and combinations thereof, wherein the proportion of the structural unit (b) in the copolymer is 5% to 35% on a molar basis, wherein the copolymer further comprises a structural unit (c), wherein the structural unit (c) is derived from monomers selected from the group consisting of monomers containing nitrile groups, monomers containing ester groups, monomers containing epoxy groups, monomers containing fluorine groups, and combinations thereof.

2. The method according to claim 1, wherein the concentration of the stripping agent in the stripping solution is 0.05 to 2 M.

3. The method according to claim 2, wherein the stripping agent is selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, lithium oxide, sodium oxide, potassium oxide, rubidium oxide, cesium oxide, calcium oxide, strontium oxide, barium oxide, and combinations thereof.

4. The method according to 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 the proportion of water in the aqueous solvent is 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, tert-butanol, n-butanol, acetone, dimethyl ketone, methyl ethyl ketone, ethyl acetate, isopropyl acetate, propyl acetate, butyl acetate, and combinations thereof.

6. The method according to claim 1, wherein the proportion of the structural unit (a) in the copolymer is 30% to 70% on a molar basis, based on the total molar number of monomer units in the copolymer binder.

7. The method according to claim 1, wherein the monomer containing the carboxylic acid group is selected from acrylic acid, methacrylic acid, crotonic acid, 2-butylcrotonic acid, cinnamic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, 4,4-dimethylitaconic acid, 2-ethylacrylic acid, isocrotonic acid, cis-2-pentenoic acid, trans-2-pentenoic acid, angelic acid, tigric acid, 3,3-dimethylacrylic acid, 3-propylacrylic acid, trans-2-methyl-3-ethylacrylic acid, cis-2-methyl-3-ethylacrylic acid, 3-isopropylacrylic acid, etc. Acrylic acid, trans-3-methyl-3-ethylacrylic acid, cis-3-methyl-3-ethylacrylic acid, 2-isopropylacrylic acid, trimethacrylic 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-octenic acid, cis-2-octenic acid, trans-2-decenoic acid, α-acetoxyacrylic acid, β-trans-... The group consisting of aryloxyacrylic acid, α-chloro-β-E-methoxyacrylic acid, methylmaleic acid, dimethylmaleic acid, phenylmaleic acid, bromomaleic acid, chloromaleic acid, dichloromaleic acid, fluoromaleic acid, difluoromaleic acid, nonyl hydrogen maleate, decyl hydrogen maleate, dodecyl hydrogen maleate, octadecyl hydrogen maleate, fluoroalkyl hydrogen maleate, maleic anhydride, methylmaleic anhydride, dimethylmaleic anhydride, acrylic anhydride, methacrylic anhydride, methacrolein, methacryloyl chloride, methacryloyl fluoride, methacryloyl bromide, and combinations thereof.

8. The method according to claim 1, wherein the monomer containing the carboxyl group is selected from acrylate, methacrylate, crotonate, 2-butylcrotonate, cinnamate, maleate, maleic anhydride, fumarate, itaconic acid, itaconic anhydride, 4,4-dimethylitaconic acid, 2-ethylacrylate, isocrotonate, cis-2-pentenoate, trans-2-pentenoate, angelic acid salt, tigrinate, 3,3-dimethylacrylate, 3-propylacrylate, trans-2- Methyl-3-ethyl acrylate, cis-2-methyl-3-ethyl acrylate, 3-isopropyl acrylate, trans-3-methyl-3-ethyl acrylate, cis-3-methyl-3-ethyl acrylate, 2-isopropyl acrylate, trimethacrylate, 2-methyl-3,3-diethyl acrylate, 3-butyl acrylate, 2-butyl acrylate, 2-pentyl acrylate, 2-methyl-2-hexenoate, trans-3-methyl-2-hexenoate, 3-methyl-3-propylpropene Salts, 2-ethyl-3-propyl acrylate, 2,3-diethyl acrylate, 3,3-diethyl acrylate, 3-methyl-3-hexyl acrylate, 3-methyl-3-tert-butyl acrylate, 2-methyl-3-pentyl acrylate, 3-methyl-3-pentyl acrylate, 4-methyl-2-hexenoate, 4-ethyl-2-hexenoate, 3-methyl-2-ethyl-2-hexenoate, 3-tert-butyl acrylate, 2,3-dimethyl-3-ethyl acrylate, 3,3-dimethyl The group consisting of 2-ethyl acrylate, 3-methyl-3-isopropyl acrylate, 2-methyl-3-isopropyl acrylate, trans-2-octenate, cis-2-octenate, trans-2-decenoate, α-acetoxy acrylate, β-trans-aryloxy acrylate, α-chloro-β-E-methoxy acrylate, methyl maleate, dimethyl maleate, phenyl maleate, bromomaleate, chloromaleate, dichloromaleate, fluoromaleate, difluoromaleate, and combinations thereof.

9. The method according to claim 1, wherein the monomer containing the sulfonic acid group 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 methacrylate, 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, vinyl hydrogen sulfate, and combinations thereof.

10. The method according to claim 1, wherein the monomer containing the sulfonate group is selected from the group consisting of 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, and combinations thereof.

11. The method according to claim 1, wherein the monomer containing the phosphonic acid group is selected from the group consisting of 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, ethyl-methacryloyloxyethylphosphonic acid, allyl hydrogen phosphate, ethylene hydrogen phosphate, and combinations thereof.

12. The method according to claim 1, wherein the monomer containing the phosphonate group is selected from the group consisting of 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, and combinations thereof.

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

14. The method of claim 13, wherein the proportion of the structural unit (b) in the copolymer is from 10% to 30% on a molar basis, based on the total number of molars of monomer units in the copolymer binder.

15. The method according to claim 13, wherein the monomer containing the amide group is selected from 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-( The group consisting of ethoxymethyl)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, and combinations thereof.

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

17. The method of claim 16, wherein the proportion of the structural unit (c) in the copolymer is from 10% to 60% on a molar basis, based on the total number of molars of monomer units in the copolymer binder.

18. The method according to claim 16, wherein the monomer containing the nitrile group is selected from the group consisting of acrylonitrile, α-haloacrylonitrile, α-alkylacrylonitrile, 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, and combinations thereof.

19. The method of claim 1, wherein the metal substrate is in the form of a foil, sheet, 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, 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.

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

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