Composite stripping method

Abstract

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

Description

Technical Field

[0001] The present invention relates to the field of material recovery methods. In particular, the present 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 Art

[0002] Increasing urbanization, rapid technological innovation, and the resulting frequent replacement of products or disposal of used consumables have led to shortened product lifespans and / or excessive waste production. With the increasing severity of the problems associated with excessive waste production, such as adverse effects on human health, negative impacts on the environment, and resource depletion, there is an urgent need for rapid action worldwide to address these complex issues using a variety of waste management methods.

[0003] Recycling, as a key component of the waste reduction hierarchy, aims to recover useful materials from waste for reuse. Recycling of materials can conserve natural resources, reduce the energy consumption associated with the extraction of raw materials (and the resulting production costs), and contribute to the reduction of greenhouse gases and SO x As material recycling can bring huge benefits, developing efficient material recycling methods is crucial to achieving a circular economy.

[0004] The term "composite" refers to a metal substrate comprising a coating applied to one or both sides of the metal substrate, wherein the coating comprises 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 modifying the surface properties to meet performance requirements in various technical applications. Some applications of coatings include adhesives, barrier formation, scratch and wear resistance, chemical resistance, wettability and biocompatibility. Applying coatings to metal substrates is often used in battery production, membrane technology, packaging materials, circuit board printing, wire or cable and biomedical applications. Therefore, separating the coating from the metal substrate is a widely used technology in material recycling.

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

[0006] On the one hand, delamination of the composite may occur within the bulk surface of the coating, rather than at the coating-metal substrate interface. Consequently, the coating may not be completely stripped from the metal substrate, with some coating remaining intact. This results in an inability to directly recover the coating material from the delamination process, leading to undesirable loss of coating material. Furthermore, the recovered metal substrate may contain high levels of impurities due to the residual coating, necessitating subsequent separation steps.

[0007] On the other hand, stripping the coating from the metal substrate can be very inefficient, sometimes requiring hours. Prolonged exposure of the composite to harsh stripping conditions is likely to cause adverse effects, such as corrosion, dissolution, and damage to the composite materials (especially the metal substrate), as well as the generation of side reaction products.

[0008] Commonly used to be responsible for the polymer binder of the bonding between coating and metal substrate, such as polyvinylidene fluoride (PVDF), has its shortcoming, i.e. it is insoluble in water, and in fact these polymers can only be dissolved in some specific organic solvents, such as N-methyl-2-pyrrolidone (NMP).NMP is flammable and poisonous, and therefore requires special treatment.NMP recovery system must be installed in drying process, to reclaim NMP steam. This will produce huge cost in manufacturing process, because setting up such recovery system needs the investment of a large amount of funds. Therefore, for being exposed to humid environment in manufacturing process in the application that is not a major problem, preferably use the polymer binder that utilizes cheaper and more environmentally friendly solvent (such as aqueous solvent, common is water) in the present invention, because it can reduce the huge capital cost of recovery system.

[0009] Polymer binders suitable for water-based coatings exhibit excellent dispersibility and stability in water and promote strong coating-to-metal substrate adhesion. However, the strong coating-to-metal substrate adhesion observed with these polymer binders can make stripping water-based coatings from attached metal substrates extremely challenging. To further optimize the performance of these water-based binders, copolymers containing structural units derived from various monomers can be employed. However, these copolymer binders still present significant challenges when used in coatings.

[0010] Composite stripping is achieved by destroying and / or rupturing the bonds between the polymer binder in the coating and the metal substrate at the coating-metal substrate interface. Therefore, to achieve high-speed, high-recovery, and high-safety stripping with minimal additional material usage and low cost, a key goal is to more efficiently destroy and / or rupture the bonds between the polymer binder in the coating and the metal substrate.

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

[0012] In view of the above challenges, there remains a need to develop a unified and simple method for achieving efficient and complete stripping of composites at the coating-metal substrate interface, wherein the composite coating comprises a polymeric binder, and wherein the polymeric binder is a copolymer. The method disclosed herein for composite stripping is intended to achieve efficient destruction and / or rupture of the bond between the copolymer binder in the composite coating and the metal substrate. Therefore, a stripping method that meets these characteristics can be applied to composites comprising copolymer binders. This method can avoid complex separation processes and contamination of the metal substrate, achieve excellent material recovery, and allow for complete composite stripping in a short period of time. Summary of the Invention

[0013] The above needs are met by various aspects and embodiments disclosed herein. In one aspect, a method for stripping a composite comprising a metal substrate and a coating applied to one or both sides of the metal substrate by immersing the composite in a stripping solution is provided.

[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 water-soluble silicate. In some embodiments, the stripping agent is a water-soluble silicate having the general formula (M2O) x (SiO2) ywherein M represents an alkali metal selected from the group consisting of sodium, potassium, rubidium, cesium, and combinations thereof, and wherein the ratio between x and y is between 1:0.485 and 1:2.76. In some embodiments, the stripping agent is selected from the group consisting of sodium metasilicate, sodium orthosilicate, sodium disilicate, potassium metasilicate, potassium orthosilicate, potassium disilicate, rubidium metasilicate, rubidium orthosilicate, rubidium disilicate, cesium metasilicate, cesium orthosilicate, cesium disilicate, and combinations thereof.

[0017] Stripping of the composites obtained using the methods provided herein is very rapid and simple, and does not result in unrecoverable loss of coating material, damage to the coating material, or the introduction of impurities into the metal substrate.

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

[0019] The present invention utilizes a stripping solution to strip battery electrodes at the electrode layer-current collector interface, significantly reducing the time required for complete stripping, maximizing the recovery of useful materials, eliminating contamination of the current collector, and eliminating the need for subsequent processing steps. Furthermore, the disclosed method has been found to be applicable to stripping both cathodes and anodes without causing corrosion to the current collector and / or the electrode active materials within the electrode layer. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0022] Figure 3 is a flow chart illustrating, in one embodiment, the steps of composite stripping disclosed herein and its subsequent further processing to extract the composite components (ie, the coating and the metal substrate) after composite stripping.

[0023] Figure 4 Shown are the cathode layer and current collector recovered after immersing the double-sided coated cathode in a stripping solution in Example 1, wherein the stripping solution at 70°C comprises 3 g / L sodium metasilicate and deionized water, and wherein the double-sided cathode comprises a copolymer binder.

[0024] Figure 5Shown is the recycled cathode of Comparative Example 1, wherein the stripping solution at 90° C. comprises 3 g / L sodium metasilicate and deionized water, and wherein the double-sided coated cathode comprises polyvinylidene fluoride (PVDF) as the polymer binder. DETAILED DESCRIPTION

[0025] In one aspect, provided herein is a method for stripping a composite by immersing the composite in a stripping solution; wherein the composite comprises a metal substrate and a coating applied to one or both sides of the metal substrate, wherein the coating comprises a copolymer binder.

[0026] In another aspect, the present invention provides a method for stripping a lithium-ion battery electrode by immersing the electrode in a stripping solution; wherein the electrode comprises a current collector and an electrode layer coated on one or both sides of the current collector, wherein the electrode layer comprises a copolymer binder.

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

[0028] The terms "positive electrode" and "cathode" are used interchangeably. Likewise, 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 the material in place and adhere it to a conductive metal substrate to form a composite. In some embodiments, a binder refers to a chemical compound, mixture of compounds, or polymer used to hold the electrode material and / or conductive agent in place and adhere it 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, a conductive agent is typically mixed with an electrode active material when forming an electrode to improve the conductivity of the electrode. 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 comprising a coating applied to one or both sides of the metal substrate, wherein the metal substrate and the coating may each comprise one or more layers. The term "composition" in the context of a composite refers to the metal substrate and the coating.

[0032] The term "polymer" refers to a compound prepared by polymerizing monomers, whether of the same or a different type. The generic term "polymer" embraces the terms "homopolymer" and "copolymer."

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

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

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

[0036] The term "polymer binder" refers to a binder having a polymeric nature. The term "copolymer binder" refers to a polymer binder, wherein the binder is specifically a copolymer.

[0037] As used herein, the term "unsaturated" refers to a moiety having one or more units of unsaturation.

[0038] The term "alkyl" or "alkyl group" refers to a group having the general formula C n H 2n+1 A monovalent group derived from a saturated, unbranched or branched aliphatic hydrocarbon by removing one hydrogen atom, wherein n is an integer or an integer between 1 and 20 or an integer between 1 and 8. Examples of alkyl groups include, but are not limited to, (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. In addition, 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 with a monocycle or multiple condensed rings. Examples of cycloalkyl groups include, but are not limited to, (C3-C7) cycloalkyl groups, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl, and saturated cyclic terpenes and saturated bicyclic terpenes, and (C3-C7) cycloalkenyl groups, such as cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl and cycloheptenyl, and unsaturated cyclic terpenes and unsaturated bicyclic terpenes. The cycloalkyl group can be unsubstituted or substituted by one or two suitable substituents. In addition, the cycloalkyl group can be monocycle 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, attached to the main carbon chain via an oxygen atom. Some non-limiting examples of alkoxy groups include methoxy, ethoxy, propoxy, butoxy, and the like. The alkoxy groups defined above may be substituted or unsubstituted, wherein the substituents may be, but are not limited to, deuterium, hydroxyl, amine, halogen, cyano, alkoxy, alkyl, alkenyl, alkynyl, mercapto, nitro, and the like.

[0041] The term "alkenyl" refers to an unsaturated straight, 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, which may be optionally 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 a hydrogen atom. Non-limiting examples of aryl groups include phenyl, naphthyl, benzyl, tolanyl, sexiphenyl, phenanthrenyl, anthracenyl, coronenyl, and tolanylphenyl. The aryl group can be unsubstituted or substituted with one or more suitable substituents. In addition, the aryl group can 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 C 30 Alkyl groups, C2 to C 30 Alkenyl groups, C2 to C 30 Alkynyl groups, C1 to C 30 Alkylene groups, C2 to C 30 an alkenylene group or a C2 to C 30 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, which optionally includes heteroatoms or substituents. Examples of such groups include, but are not limited to, phenyl, tolyl, biphenyl, o-terphenyl, m-terphenyl, p-terphenyl, naphthyl, anthryl, phenanthryl, pyrenyl, triphenylene, and derivatives thereof.

[0045] The term "substituted" when used to describe a compound or chemical moiety means that at least one of the hydrogen atoms of the compound or chemical moiety is replaced with another chemical moiety. Examples of substituents include, but are not limited to, halogen; alkyl; heteroalkyl; alkenyl; alkynyl; aryl; heteroaryl; hydroxy; alkoxy; amine; nitro; thiol; thioether; imino; cyano; amide; phosphonato; phosphinate; carboxyl; thiocarbonyl; sulfonyl; sulfonamide; acyl; formyl; acyloxy; alkoxycarbonyl; carbonyl; haloalkyl (e.g., trifluoromethyl); carbocyclic cycloalkyl, which may be monocyclic or fused or non-fused polycyclic (e.g., cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl) or heterocyclic alkyl, which may be monocyclic or fused or non-fused polycyclic (e.g., pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, or thiazinyl); carbocyclic or heterocyclic, monocyclic or fused or non-fused polycyclic aryl (e.g., phenyl, naphthyl, pyrrolyl, indolyl, furanyl, thienyl, thiophene, thiazinyl); 1-Hydroxy-1,1-diophenyl, ... -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 also be optionally substituted with fused ring structures or bridge structures (e.g., -OCH2O-). These substituents may be further substituted with substituents selected from these groups. Unless otherwise indicated, all chemical groups disclosed herein may be substituted.

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

[0047] The term "monomer unit" refers to a constitutional unit contributed to the structure of a polymer by a single monomer.

[0048] The term "structural unit" refers to the total monomer units 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 proton of the acid is replaced by a metal cation. In some embodiments, the proton of the acid is replaced by an ammonium ion.

[0050] The term "planetary mixer" refers to a device that can be used to mix or stir different materials to produce a homogeneous mixture, which consists of paddles that perform 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 axes and also rotate continuously around the container. The speed can be expressed in units of revolutions per minute (rpm), which refers to the number of revolutions a rotating body completes in one minute.

[0051] The term "ultrasonic generator" refers to a device capable of applying ultrasonic energy to agitate particles in a sample. Any ultrasonic generator capable of dispersing the slurries disclosed herein may be used herein. 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 into a liquid sample through the walls of the ultrasonic bath container.

[0053] The term "probe-type ultrasonic generator" refers to an ultrasonic probe immersed in a medium for direct ultrasonic treatment. The term "direct ultrasonic treatment" refers to the direct coupling of ultrasound into the treatment fluid.

[0054] The term "ultrasonic flow cell" or "ultrasonic reactor chamber" refers 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 recirculating configuration.

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

[0056] The term "current collector" refers to any conductive layer that is in contact with an electrode layer and is capable of conducting current to an electrode during discharge or charge of a secondary battery. Some non-limiting examples of current collectors include a single conductive metal layer or substrate and 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 having 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 comprising an electrochemically active material that is in contact with a current collector. In some embodiments, the electrode layer is formed by applying a coating to a 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 in which the current collector is a metal substrate and the electrode layer is a coating.

[0058] The term "room temperature" refers to a room temperature of about 18°C ​​to about 30°C, for example, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30°C. In some embodiments, room temperature refers to a temperature of about 20°C + / - 1°C, or + / - 2°C, or + / - 3°C. In other embodiments, room temperature refers to a temperature of about 22°C or about 25°C.

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

[0060] The term "peel strength" refers to the amount of force required to separate a current collector and an electrode active material coating that are bonded to each other. It is a measure of the strength of the bond between the two materials and is usually expressed in N / cm.

[0061] The term "adhesion strength" refers to the amount of force required to separate a current collector and a polymer binder coating that are adhered to each other. It is a measure of the strength of the bond between the two materials and is usually expressed in N / cm.

[0062] The term "C-rate" refers to the charge or discharge 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 all the stored energy is used in one hour; 0.1C means 10% of the energy is used in one hour or the entire energy is used in 10 hours; and 5C means the entire energy is used in 12 minutes.

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

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

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

[0066] In the following description, all numerical values ​​disclosed herein are approximate values, regardless of whether the word "about" or "approximately" is used in conjunction with them. They may vary by 1%, 2%, 5%, or sometimes 10% to 20%. Whenever a value with a lower limit R is disclosed, L and upper limit R U When a numerical range of R=R is provided, any value within the range is specifically disclosed. Specifically, the following values ​​within the range are specifically disclosed: L +k*(R U -R L ), wherein k is a variable from 0% to 100%. Also, any numerical range defined by two R values ​​determined in the above manner is specifically disclosed.

[0067] In this specification, all cases where the singular number is used include cases where the plural number is used, and vice versa.

[0068] As used herein, a "composite" refers to a metal substrate comprising a coating applied to one or both sides of the 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 a composite, generally designated 100, is shown. Composite 100 comprises a metal substrate 101 and a coating 102 applied to one side of metal substrate 101. Applying a coating to a metal substrate, i.e., forming a composite, is one of the most common techniques used to modify the surface properties of a metal substrate to meet the performance requirements of various applications. Coatings are often used for a variety of purposes, including protection (e.g., protection against chemicals, corrosion, scratches, and wear), adhesion, wettability modification, or biocompatibility.

[0069] The adhesion between the composite inner coating and the metal substrate is achieved by 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 that are compatible with aqueous solvents (most commonly water) can firmly adhere the coating to the metal substrate. Therefore, such copolymer binders are preferably used in the present invention. In addition, since these copolymer binders can achieve good dispersibility and stability in water, the water-based coatings comprising these copolymer binders will have good processability in formation, storage and utilization.

[0070] In some embodiments, the substrate is a metal 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 metal substrate is exposed to ambient air for a period of time. Ambient air primarily contains oxygen, water, and several organic and inorganic compounds. When a metal substrate is exposed to the naturally occurring oxygen in the atmosphere, metal oxides inevitably form on the metal substrate surface. For example, aluminum metal naturally reacts strongly with atmospheric oxygen, which can trigger the formation of aluminum oxide on the exposed aluminum surface. Aluminum oxide protects the aluminum within from further oxidation, giving aluminum good corrosion resistance. When the metal oxide on the metal substrate surface comes into contact with moisture in the ambient air, the metal oxide undergoes hydroxylation, leaving the metal oxide surface rich in hydroxyl groups (-OH).

[0072] The hydroxyl group on the surface of the metal substrate consists of an 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, the hydrogen atom is capable of forming a hydrogen bond with another molecule containing a highly electronegative atom (such as O, N, or F), and the oxygen atom is capable of accepting a hydrogen bond from a hydrogen atom of another molecule similarly bound to a highly electronegative atom (such as O, N, or F).

[0073] At the same time, the metal part of the substrate is still a partially positively charged metal substance (M δ+ ) exists on the surface of the metal substrate in the form of, for example, a metal oxide formed on the surface of the metal substrate.

[0074] Figure 2 Schematic diagram showing the coating-metal substrate interface structure of the proposed composite, denoted by 200. Hydroxyl (-OH) groups, partially positively charged metal species (M δ+ ) and oxygen (O) atoms of the metal oxide are present on the surface of the metal substrate 201. The copolymer binder within and / or on the surface of the coating layer 202 includes a structural unit derived from a monomer containing a carboxylic acid group. In this case, the structural unit derived from the monomer containing a carboxylic acid group includes a carboxylate group, wherein the carboxylate group is a salt of a carboxylic acid group.

[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 surface of the metal substrate and the O atoms in the metal oxide through hydrogen bonding. In addition, the anions of the carboxylate groups (COO in this case) contained in the copolymer binder may also interact with the O and / or H atoms of the hydroxyl groups on the surface of the metal substrate and the O atoms in the metal oxide. - ) and the metal substrate surface M δ+ Ion-dipole interactions occur between the substances. Therefore, hydrogen bonds and / or ion-dipole attractions are formed between the coating and the metal substrate, and these two 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-to-metal substrate adhesion for a variety of applications. However, this strong adhesion presents additional challenges in separating the coating from the metal substrate to which it is attached during subsequent recycling steps when a product containing the composite reaches the end of its useful life or service life, or when product defects are generated during the manufacturing process.

[0077] Stripping of the coating from the metal substrate in the composite is achieved by disrupting and / or breaking the bonds between the copolymer binder in the coating and the surface of the metal substrate. Copolymers of different compositions exhibiting different specific properties require different methods for separating the coating from the metal substrate. Therefore, the methods of the present invention are specifically developed to strip the composite by disrupting and / or breaking the bonds between the waterborne copolymer binder disclosed herein and the surface of the metal substrate.

[0078] The present invention provides a method for stripping a composite by immersing the composite in a stripping solution, wherein the composite comprises a metal substrate and a coating applied to one or both sides of the metal substrate, wherein the coating comprises a copolymer binder.

[0079] In some embodiments, debonding 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 alkali metal silicate. In some embodiments, the aqueous solvent consists solely of water.

[0081] In the stripping solution, the alkali metal silicate reacts with water to form hydroxide ions. These generated 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 binder and the substrate. The aqueous solvent (e.g., water) present in the stripping solution also disrupts the ion-dipole interactions between the copolymer binder in the coating and the metal substrate surface. These aqueous solvent molecules further serve to solvate the copolymer, forming a solvent shell (a hydration shell in the case of water), which greatly reduces the strength of the electrostatic interaction between the copolymer binder in the coating and the metal substrate.

[0082] In some embodiments, some functional groups that can dissociate in water, such as carboxylic acid groups, are not completely dissociated in water in the copolymer. The hydroxide ions or silicate ions produced by the reaction of silicate ions with water can further neutralize the undissociated functional groups, thereby forming corresponding anions, such as carboxylic acid functional groups, when there are carboxylic acid anions. The attraction of water to such anions (such as carboxylates) is stronger than the attraction of water to the undissociated functional groups. Along with the ionization of these dissociable functional groups, the solvation effect of the ionized functional groups in water can be stronger, thereby can more effectively weaken the interaction between polymer and substrate. Therefore, this causes coating peeling.

[0083] Therefore, the present invention discloses a method for stripping a composite by disrupting and / or breaking hydrogen bonds and / or ion-dipole interactions between a coating and a metal substrate surface using a stripping solution, wherein the coating comprises a copolymer binder. The method is simple and does not require complex separation procedures. The proposed method ensures complete stripping of the composite at the coating-metal substrate interface without contaminating the metal substrate, thereby achieving excellent material recovery and enabling efficient and rapid stripping of the composite.

[0084] The non-ionized 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 strip the coating from the metal substrate because the aqueous solvent will have a significantly lower solvation effect on these non-ionized copolymer functional groups; and the interactions (mainly hydrogen bonds) between these copolymer functional groups in the coating and the metal substrate surface are generally not destroyed and reduced to the extent that the composite can be completely stripped.

[0085] Therefore, both the stripping agent and the aqueous solvent should be used in combination as a stripping solution to achieve excellent composite stripping effect. In some embodiments, the stripping solution comprises a stripping agent and an aqueous solvent.

[0086] In some embodiments, the stripping agent is a water-soluble silicate. In some embodiments, the stripping agent is a water-soluble silicate having the general formula (M2O) x (SiO2) yIn some embodiments, the ratio of x to y is 1:0.485, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4, 1:2.5, 1:2.6, 1:2.7, or 1:2.76. In some embodiments, the stripping agent is selected from the group consisting of sodium metasilicate, sodium orthosilicate, sodium disilicate, potassium metasilicate, potassium orthosilicate, potassium disilicate, rubidium metasilicate, rubidium orthosilicate, rubidium disilicate, cesium metasilicate, cesium orthosilicate, cesium disilicate, and combinations thereof.

[0087] In some embodiments, the aqueous solvent is a solution containing water as a major 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 about 51% to about 100%, about 51% to about 95%, about 51% to about 90%, about 51% to about 85%, about 51% to about 80%, about 51% to about 75%, about 51% to about 70%, about 55% to about 100%, about 55% to about 95%, about 55% to about 90%, about 55% to about 85%, about 55% to about 80%, about 60% to about 100% by weight. %, 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%.

[0088] In some embodiments, the proportion of water in the aqueous solvent by weight 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%. In some embodiments, the proportion of water in the aqueous solvent by weight 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%. In some embodiments, the aqueous solvent consists solely of water, i.e., the proportion of water in the aqueous solvent by weight is 100%.

[0089] Some 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 can be used as part of the stripping solution to form a solvent shell around the copolymer binder of the coating and the surface of the metal substrate at the coating-metal substrate surface interface. This helps to disrupt the interaction between the copolymer binder in the coating and the metal substrate surface, thereby resulting in complete stripping of the composite.

[0090] Any solvent miscible with water or volatile solvent can be used as the secondary component (i.e., solvent other than water) of the aqueous solvent. Some non-limiting examples of solvent miscible with water or volatile solvent include alcohol, lower aliphatic ketones, lower alkyl acetates and combinations thereof. The addition of alcohol can improve the solubility of the stripping agent and lower the freezing point of water. Some non-limiting examples of alcohol include C1-C4 alcohols, such as methanol, ethanol, isopropanol, n-propyl alcohol, tert-butyl alcohol, n-butyl alcohol and combinations thereof. Some non-limiting examples of lower aliphatic ketones include acetone, dimethyl ketone, methyl ethyl ketone (MEK) and combinations thereof. Some non-limiting examples of lower alkyl acetates include ethyl acetate (EA), isopropyl acetate, propyl acetate, butyl acetate (BA) and combinations thereof. In some embodiments, the aqueous solvent does not include alcohol, lower aliphatic ketones, lower alkyl acetates or combinations thereof.

[0091] Surfactants are used as additives to stripping solutions to improve stripping efficiency. However, the addition of surfactants to the stripping solution can introduce impurities into the resulting solution, reducing product purity or requiring time and expense to develop a separation system to remove the surfactant. Furthermore, surfactants can be harmful to the environment upon discharge, and some surfactants may pose health risks. Therefore, in some embodiments, no surfactant is added to the stripping solution. In some embodiments, the stripping solution is free of cationic, anionic, nonionic, and amphoteric surfactants.

[0092] 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-acyl sarcosine salts; salts); alkyl phosphates; polyoxyalkylene alkyl ether phosphates; long-chain sulfosuccinates; long-chain N-acyl glutamates; polymers and copolymers comprising acrylic acid, anhydrides, esters, vinyl monomers and / or olefins and their alkali metal, alkaline earth metal and / or ammonium salt derivatives; polycarboxylates; formalin condensates of naphthalenesulfonic acid; alkylnaphthalenesulfonic acids; naphthalenesulfonic acids; alkylnaphthalenesulfonic salts; formalin condensates of an acid and a naphthalenesulfonic salt (e.g., an alkali metal, alkaline earth metal, ammonium or amine salt thereof); melaminesulfonic acid; alkylmelaminesulfonic acids; formalin condensates of melaminesulfonic acid; formalin condensates of alkylmelaminesulfonic acid; alkali metal, alkaline earth metal, ammonium and amine salts of melaminesulfonic acid; ligninsulfonic acid; and anionic surfactants of the alkali metal, alkaline earth metal, ammonium and amine salts of ligninsulfonic acid.

[0093] In some embodiments, cationic surfactants including alkyltrimethylammonium salts, such as stearyltrimethylammonium chloride, dodecyltrimethylammonium chloride, and cetyltrimethylammonium bromide; dialkyldimethylammonium salts; trialkylmethylammonium salts; tetraalkylammonium salts; alkylamine salts; benzalkonium salts; alkylpyridinium salts; and imidazolium salts are not added to the stripping solution.

[0094] In some embodiments, the stripping solution does not contain added nonionic surfactants including alkyl ethers of 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 oils; polyoxyalkylene hydrogenated castor oils; polyoxyalkylene sorbitan fatty acid esters; polyglycerol fatty acid esters; alkyl glycerol ethers; polyoxyalkylene cholesterol ethers; alkyl glucosides; sucrose fatty acid esters; polyoxyalkylene alkylamines; polyoxyethylene-polyoxypropylene block polymers; sorbitan fatty acid esters and fatty acid alkanolamides.

[0095] In some embodiments, the stripping solution does not contain 2-undecyl-N, N-(hydroxyethylcarboxymethyl)-2-imidazoline sodium salt, 2-coco-2-imidazoline hydroxide-1-carboxyethyloxy disodium salt; imidazoline-based amphoteric surfactants; 2-heptadecanyl-N-carboxymethyl-N-hydroxyethylimidazoline betaine, lauryl dimethylaminoacetic acid betaine, alkyl betaines, amide betaines, sulfobetaines and other betaine-based amphoteric surfactants; N-lauryl glycine, N-lauryl β-alanine, N-stearyl β-alanine, lauryl dimethylamino oxide, oleyl dimethylamino oxide, sodium lauryl glutamate, lauryl dimethylaminoacetic acid betaine, stearyl dimethylaminoacetic acid betaine, cocoamidopropyl hydroxysulfobetaine and 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazoline betaine.

[0096] In some embodiments, a composite comprises a metal substrate and a coating applied to one or both sides of the metal substrate.

[0097] 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 a waterborne copolymer.

[0098] In some embodiments, the copolymer comprises structural units (a), wherein structural units (a) are derived from monomers 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 an acid salt group comprises an alkali metal cation. Examples of alkali metals that form alkali metal cations include lithium, sodium, and potassium. In some embodiments, the monomer containing an acid salt group comprises an ammonium cation. In some embodiments, structural unit (a) may comprise a combination of monomers containing salt groups and monomers containing acid groups.

[0099] In some embodiments, the monomer containing a carboxylic acid group is acrylic acid, methacrylic acid, crotonic acid, 2-butyl crotonic acid, cinnamic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, 4,4-dimethyl itaconic acid (tetraconic acid) or a combination thereof. In certain embodiments, the monomer containing a carboxylic acid group is 2-ethyl acrylic acid, isocrotonic acid, cis-2-pentenoic acid, trans-2-pentenoic acid, angelic acid, tiglic acid (tiglic acid) or a combination thereof. acid), 3,3-dimethylacrylic acid, 3-propylacrylic acid, trans-2-methyl-3-ethylacrylic acid, cis-2-methyl-3-ethylacrylic acid, 3-isopropylacrylic acid, trans-3-methyl-3-ethylacrylic acid, cis-3-methyl-3-ethylacrylic acid, 2-isopropylacrylic acid, trimethylacrylic acid, 2-methyl-3,3-diethylacrylic acid, 3-butylacrylic acid, 2-butylacrylic acid, 2-pentylacrylic acid, 2-methyl-2-hexenoic acid, trans-3-methyl-2-hexenoic acid, 3-methyl-3-propylacrylic acid, 2-ethyl-3-propylacrylic acid, 2,3-diethylacrylic acid, 3,3-diethylacrylic acid, 3-methyl-3-hexylacrylic acid, 3-methyl-3-tert-butylacrylic acid, 2-methyl-3-pentylacrylic acid, 3-methyl-3-pentylacrylic acid, 4-methyl-2-hexenoic acid, 4-ethyl-2-hexenoic acid, 3-methyl-2-ethyl-2-hexenoic acid, 3-tert-butylacrylic acid, 2,3-dimethyl-3-ethylacrylic acid, 3,3-dimethyl-2-ethylacrylic acid, 3-methyl-3-isopropylacrylic acid, 2-methyl-3-isopropylacrylic acid, trans-2-octenoic acid, cis-2-octenoic acid, trans-2-decenoic acid, α-acetoxyacrylic acid, β-trans-aryloxyacrylic acid, α-chloro-β-E-methoxyacrylic acid, or a combination 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 hydrogen maleate, 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.

[0100] In some embodiments, the carboxylate group-containing monomer is acrylate, methacrylate, crotonate, 2-butylcrotonate, cinnamate, maleate, maleic anhydride salt, fumarate, itaconate, itaconic anhydride salt, 4,4-dimethylitaconate (tetraconic acid salt), or a combination thereof. In certain embodiments, the carboxylate group-containing monomer is 2-ethylacrylate, isocrotonate, cis-2-pentenoate, trans-2-pentenoate, angelate, tiglate, 3,3-dimethylacrylate, 3-propylacrylate, trans-2-methyl-3-ethylacrylate, cis-2-methyl-3-ethylacrylate, 3-isopropylacrylate, trans-3-methyl-3-ethylacrylate, cis-3-methyl-3-ethylacrylate, 2-isopropylacrylate, trimethylacrylate, 2-methyl-3,3-diethylacrylate, 3-butylacrylate, 2-butylacrylate, 2-pentylacrylate, 2-methyl-2-hexenoate, trans-3-methyl-2-hexenoate, 3-methyl-3-propylacrylate, 2-ethyl-3-propylacrylate, 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-octenoate, cis-2-octenoate, trans-2-decenoate, α-acetoxyacrylate, β-trans-aryloxyacrylate, α-chloro-β-E-methoxyacrylate, or a combination thereof. In some embodiments, the carboxylate group-containing monomer is methylmaleate, dimethylmaleate, phenylmaleate, bromomaleate, chloromaleate, dichloromaleate, fluoromaleate, difluoromaleate, or a combination thereof.

[0101] In some embodiments, the monomer containing a sulfonic acid group is vinyl sulfonic acid, methylvinyl sulfonic acid, allylvinyl sulfonic acid, allyl sulfonic acid, methylallyl sulfonic acid, styrene sulfonic acid, 2-sulfoethyl methacrylic acid, 2-methyl-2-propene-1-sulfonic acid, 2-acrylamido-2-methyl-1-propane sulfonic acid, 3-allyloxy-2-hydroxy-1-propane sulfonic acid, allyl hydrogen sulfate, vinyl hydrogen sulfate, or a combination thereof.

[0102] In some embodiments, the sulfonate group-containing monomer 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 a combination thereof.

[0103] In some embodiments, the monomer containing a phosphonic acid group is vinylphosphonic acid, allylphosphonic acid, vinylbenzylphosphonic acid, acrylamidoalkylphosphonic acid, methacrylamidoalkylphosphonic acid, acrylamidoalkyldiphosphonic acid, acrylphosphonic acid, 2-methacryloyloxyethylphosphonic acid, bis(2-methacryloyloxyethyl)phosphonic acid, ethylene 2-methacryloyloxyethylphosphonic acid, ethyl-methacryloyloxyethylphosphonic acid, allyl hydrogen phosphate, vinyl hydrogen phosphate, or a combination thereof.

[0104] In some embodiments, the phosphonate group-containing monomer is vinyl phosphonate, allyl phosphonate, vinyl benzyl phosphonate, acrylamidoalkyl phosphonate, methacrylamidoalkyl phosphonate, acrylamidoalkyl diphosphonate, acryloyl phosphonate, 2-methacryloyloxyethyl phosphonate, bis(2-methacryloyloxyethyl)phosphonate, ethylene 2-methacryloyloxyethyl phosphonate, ethyl-methacryloyloxyethyl phosphonate, allyl phosphate, vinyl phosphate, or a combination thereof.

[0105] In some embodiments, the proportion of structural unit (a) in the copolymer is about 15% to about 30%, about 16% to about 30%, about 17% to about 30%, about 18% to about 30%, about 19% to about 30%, about 20% to about 30%, about 21% to about 30%, about 22% to about 30%, about 23% to about 30%, about 24% to about 30%, about 26% to about 30%, about 27% to about 30%, about 28% to about 30%, about 29% to about 30%, about 30% to about 30%, about 31% to about 30%, about 32% to about 30%, about 33% to about 30%, about 34% to about 30%, about 36% to about 30%, about 37% to about 30%, about 38% to about 30%, about 39% to about 30%, about 40% to about 30%, about 41% to about 30%, about 42% to about 30%, about 43% to about 30%, about 44% to about 30%, about 46% to about 30%, about 47% to about 30%, about 48% to about 30%, about 49% to about 50%, about 51% to about 51%, about 52% to about 53%, about 54% to about 55%, about 56% to about 57%, about 58% to about 59%, about 60% to about 61%, about 62% to about 63%, about 64% to about 65%, about 66% to about 67%, about 68% to about 69%, about 70% to about 71%, about 71% to about 72%, about 72% to about 73%, 25% to about 30%, about 15% to about 27%, about 16% to about 27%, about 17% to about 27%, about 18% to about 27%, about 19% to about 27%, about 20% to about 27%, about 21% to about 27%, about 22% to about 27%, about 15% to about 25%, about 16% to about 25%, about 17% to about 25%, about 18% to about 25%, about 19% to about 25%, or about 20% to about 25%.

[0106] In some embodiments, based on the total moles of monomer units in the copolymer binder, the proportion of structural unit (a) in the copolymer is less than 30%, less than 29%, less than 28%, less than 27%, less than 26%, less than 25%, less than 24%, less than 23%, less than 22%, less than 21% or less than 20% by mole. In some embodiments, based on the total moles of monomer units in the copolymer binder, the proportion of structural unit (a) in the copolymer is more than 15%, more than 16%, more than 17%, more than 18%, more than 19%, more than 20%, more than 21%, more than 22%, more than 23%, more than 24% or more than 25% by mole.

[0107] In some embodiments, the copolymer further comprises a structural unit (b) derived from a monomer selected from the group consisting of an amide group-containing monomer, a hydroxyl group-containing monomer, and combinations thereof.

[0108] In some embodiments, the amide group-containing monomer 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. , N-(propyloxymethyl)methacrylamide, N-(butoxymethyl)methacrylamide, N,N-dimethylmethacrylamide, N-(3-(dimethylamino)propyl)methacrylamide, N-(2-(dimethylamino)ethyl)methacrylamide, N,N-(dihydroxymethyl)methacrylamide, diacetone methacrylamide, diacetone acrylamide, methacryl morpholine, N-hydroxymethylacrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, N,N'-methylenebisacrylamide (MBA), N-hydroxymethylacrylamide, or a combination thereof.

[0109] In some embodiments, the monomer containing a hydroxyl group is a monomer containing a hydroxyl group, containing C1 to C 20 Alkyl groups or C5 to C 20In some embodiments, the monomer containing a 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-cyclohexanedimethanol mono(meth)acrylate, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol mono(meth)acrylate, allyl alcohol, or a combination thereof.

[0110] In some embodiments, the proportion of structural unit (b) in the copolymer is from about 5% to about 20%, from about 6% to about 20%, from about 7% to about 20%, from about 8% to about 20%, from about 9% to about 20%, from about 10% to about 20%, from about 11% to about 20%, from about 12% to about 20%, from about 13% to about 20%, from about 14% to about 20%, from about 15% to about 20%, from about 5% to about 17%, from about 6% to about 17%, from about 7% to about 17%, from about 8% to about 17%, from about 9% to about 17%, from about 10% to about 17%, from about 11% to about 17%, from about 12% to about 17%, from about 5% to about 15%, from about 6% to about 15%, from about 7% to about 15%, from about 8% to about 15%, from about 9% to about 15%, or from about 10% to about 15%, by mole, based on the total moles of monomer units in the copolymer binder.

[0111] In some embodiments, based on the total moles of monomer units in the copolymer binder, the proportion of structural unit (b) in the copolymer is less than 20%, less than 19%, less than 18%, less than 17%, less than 16%, less than 15%, less than 14%, less than 13%, less than 12%, less than 11% or less than 10% by mole. In some embodiments, based on the total moles of monomer units in the copolymer binder, the proportion of structural unit (b) in the copolymer is more than 5%, more than 6%, more than 7%, more than 8%, more than 9%, more than 10%, more than 11%, more than 12%, more than 13%, more than 14% or more than 15% by mole.

[0112] In some embodiments, the copolymer further comprises a structural unit (c) derived from a monomer selected from the group consisting of a nitrile group-containing monomer, an ester group-containing monomer, an epoxy group-containing monomer, a fluorine-containing monomer, and combinations thereof.

[0113] In some embodiments, the monomer containing a nitrile group includes an α,β-ethylenically unsaturated nitrile monomer. 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, vinylidenecyanide, or a combination thereof.

[0114] In some embodiments, the ester group-containing monomer is C1-C 20 Alkyl acrylate, C1-C 20 Alkyl (meth) acrylate, cycloalkyl acrylate or a combination thereof. In some embodiments, the monomer containing an ester group is methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, sec-butyl acrylate, tert-butyl acrylate, amyl 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, stearyl acrylate or a combination thereof. In some embodiments, the monomer containing an ester group is cyclohexyl acrylate, cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate, 3,3,5-trimethylcyclohexyl acrylate or a combination thereof. In some embodiments, the ester group-containing monomer 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 a combination thereof.

[0115] 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, epoxy-4-vinylcyclohexene, 1,2-epoxy-5,9-cyclododecadiene, or a combination thereof.

[0116] 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, glycidyl 2,4-dimethylpentenoate, glycidyl 4-hexenoate, glycidyl 4-hexenoate, glycidyl 5-methyl-4-hexenoate, glycidyl sorbate, glycidyl linoleate, glycidyl oleate, glycidyl 3-butenoate, glycidyl 3-pentenoate, glycidyl 4-methyl-3-pentenoate, or a combination thereof.

[0117] In some embodiments, the fluorinated monomer is a C1-C 20 Acrylate, methacrylate or a combination thereof containing an alkyl group of C1-C alkyl, wherein the monomer contains at least one fluorine atom. In some embodiments, the fluorine-containing monomer is a perfluoroalkyl acrylate, such as perfluorododecyl acrylate, perfluoro-n-octyl acrylate, perfluoro-n-butyl acrylate, perfluorohexylethyl acrylate and perfluorooctylethyl acrylate; a perfluoroalkyl methacrylate, such as perfluorododecyl methacrylate, perfluoro-n-octyl methacrylate, perfluoro-n-butyl methacrylate, perfluorohexylethyl methacrylate and perfluorooctylethyl methacrylate; a perfluorooxyalkyl acrylate, such as perfluorododecyloxyethyl acrylate and perfluorodecyloxyethyl acrylate; a perfluorooxyalkyl methacrylate, such as perfluorododecyloxyethyl methacrylate and perfluorodecyloxyethyl methacrylate or a combination thereof. In some embodiments, the fluorine-containing monomer is a monomer containing at least one C1-C 20 The fluorinated monomer is a carboxylate salt comprising an alkyl group and at least one fluorine atom, wherein the carboxylate salt is selected from the group consisting of crotonate, malate, fumarate, itaconate, or a combination thereof. In some embodiments, the fluorinated monomer is vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, fluoroalkyl vinyl ether, perfluoroalkyl vinyl ether, hexafluoropropylene, 2,3,3,3-tetrafluoropropylene, vinylidene fluoride, tetrafluoroethylene, 2-fluoroacrylate, or a combination thereof.

[0118] In some embodiments, the proportion of structural unit (c) in the copolymer is about 50% to about 75%, about 51% to about 75%, about 52% to about 75%, about 53% to about 75%, about 54% to about 75%, about 55% to about 75%, about 56% to about 75%, about 57% to about 75%, about 58% to about 75%, about 59% to about 75%, about 60% to about 75%, about 61% to about 75%, about 62% to about 75%, about 63% to about 75%, about 64% to about 75%, about 65% to about 75%, ...65% to about 75%, about 65% to about 75%, about 65% to about 75%, about 65% to about 75%, about 65% to about 75%, about 65% to about 75%, about 65% to about 75%, about 65% to about 75%, about 65% to about 75%, about 65% to about 75%, about 65% to about 75%, about 65% to about 75%, about 65% to about 75%, 70%, about 51% to about 70%, about 52% to about 70%, about 53% to about 70%, about 54% to about 70%, about 55% to about 70%, about 56% to about 70%, about 57% to about 70%, about 58% to about 70%, about 59% to about 70%, about 60% to about 70%, about 61% to about 70%, about 62% to about 70%, about 63% to about 70%, about 64% to about 70%, about 65% to about 70%, about 55% to about 65%, about 56% to about 65%, about 57% to about 65%, about 58% to about 65%, about 59% to about 65%, or about 60% to about 65%.

[0119] In some embodiments, the proportion of structural unit (c) in the copolymer is less than 75%, less than 74%, less than 73%, less than 72%, less than 71%, less than 70%, less than 69%, less than 68%, less than 67%, less than 66%, less than 65%, less than 64%, less than 63%, less than 62%, less than 61%, less than 60%, less than 59%, less than 58%, less than 57%, less than 56% or less than 55% by mole, based on the total moles of monomer units in the copolymer binder. In some embodiments, the proportion of structural unit (c) in the copolymer is more than 50%, more than 51%, more than 52%, more than 53%, more than 54%, more than 55%, more than 56%, more than 57%, more than 58%, more than 59%, more than 60%, more than 61%, more than 62%, more than 63%, more than 64%, more than 65%, more than 66%, more than 67%, more than 68%, more than 69% or more than 70% by mole, based on the total moles of monomer units in the copolymer binder.

[0120] In other embodiments, the copolymer further 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 limitation. In some embodiments, the olefin comprises C2-C 20 Aliphatic compounds, C8-C 20 Aromatic compounds or cyclic compounds containing vinyl unsaturated bonds, C4-C 40Diolefins and combinations thereof. In some embodiments, olefin is styrene, ethylene, propylene, isobutylene, 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 its combination. In some embodiments, copolymer does not contain the structural unit derived from olefin. In some embodiments, the copolymer does not contain structural units derived from styrene, ethylene, propylene, isobutylene, 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.

[0121] Monomers containing conjugated diene groups are olefins. In some embodiments, monomers containing conjugated diene groups include C4-C 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; substituted side chain conjugated hexadiene and combinations thereof. In some embodiments, the copolymer does not contain C4-C 40 Diene; 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; structural units of substituted linear conjugated pentadiene or substituted side chain conjugated hexadiene.

[0122] In other embodiments, the copolymer further comprises structural units derived from monomers containing aromatic vinyl groups. In some embodiments, the monomer containing aromatic vinyl groups is styrene, α-methylstyrene, vinyltoluene, divinylbenzene, or a combination 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.

[0123] 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 alloys thereof. 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 alloys thereof. In some embodiments, the metal substrate has a two-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.

[0124] In some embodiments, when the metal substrate comprises more than one layer, the metal substrate comprises a 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, polyepoxy, poly(acrylonitrile butadiene styrene), polyimide, polyolefin, polyethylene, polypropylene, polyphenylene sulfide, poly(vinyl ester), polyvinyl chloride, polyether, polyphenylene ether, cellulosic polymers, and combinations thereof. When the metal substrate comprises a layer of insulating material, the coating is applied to the metal layer on the exterior of the substrate.

[0125] In some embodiments, the metal substrate is coated with a layer of carbon-containing material. This layer of carbon-containing material will be part of the coating. In some embodiments, the metal substrate is not coated with a layer of carbon-containing material.

[0126] If the composite is not immersed in the stripping solution for an adequate time, the stripping agent and aqueous solvent contained in the stripping solution may not have sufficient time to destabilize, disrupt, and destroy the bonds initially formed between the coating and the metal substrate surface to allow the composite to be completely stripped. However, if the composite is immersed in the stripping solution for an extended period of time, the metal substrate may corrode due to the extended contact time between the composite and the stripping agent (e.g., alkali metal silicate) contained in the stripping solution. The time used for stripping is not particularly limited, but the time used should be long enough to allow complete stripping to occur, but short enough to prevent corrosion of the metal substrate.

[0127] In some embodiments, the time for immersing the composite in the stripping solution 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, from about 30 seconds to about 45 minutes, from about From about 30 seconds to about 30 minutes, from about 30 seconds to about 20 minutes, from about 30 seconds to about 10 minutes, from about 30 seconds to about 5 minutes, from about 60 seconds to about 90 minutes, from about 60 seconds to about 75 minutes, from about 60 seconds to about 60 minutes, from about 60 seconds to about 45 minutes, from about 60 seconds to about 30 minutes, from about 60 seconds to about 20 minutes, from about 60 seconds to about 10 minutes, from about 60 seconds to about 5 minutes, from about 120 seconds to about 60 minutes, from about 120 seconds to about 45 minutes, from about 120 seconds to about 30 minutes, from about 120 seconds to about 20 minutes, from about 120 seconds to about 10 minutes, or from about 120 seconds to about 5 minutes.

[0128] In some embodiments, the composite is immersed in the stripping solution for 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 composite is immersed in the stripping solution for 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.

[0129] The temperature during stripping should not be so low that it takes a long time to achieve complete stripping, nor so high that it creates a health and safety risk.

[0130] In some embodiments, the temperature at which the composite is immersed in the stripping solution is about 51°C to about 90°C, about 53°C to about 90°C, about 55°C to about 90°C, about 57°C to about 90°C, about 59°C to about 90°C, about 60°C to about 90°C, about 61°C to about 90°C, about 63°C to about 90°C, about 65°C to about 90°C, about 67°C to about 90°C, about 69°C to about 90°C, about 71°C to about 90°C, about 73°C to about 90°C, about 75°C to about 90°C, about 51°C to about 75°C, about 53°C to about 75°C, about 55°C to about 75°C, about 57°C to about 75°C, about 59°C to about 75°C, about 61°C to about 75°C, about 63°C to about 75°C, about 65°C to about 75°C, about 51°C to about 65°C, about 53°C to about 65°C, or about 55°C to about 65°C.

[0131] In some embodiments, the temperature at which the composite is immersed in the stripping solution is less than 90° C., less than 88° C., less than 86° C., less than 84° C., less than 82° C., less than 80° C., less than 78° C., less than 76° C., less than 74° C., less than 72° C., less than 70° C., less than 68° C., less than 66° C., less than 64° C., less than 62° C., or less than 60° C. In some embodiments, the temperature at which the composite is immersed in the stripping solution is greater than 10° C., greater than 51° C., greater than 52° C., greater than 54° C., greater than 56° C., greater than 58° C., greater than 60° C., greater than 62° C., greater than 64° C., greater than 66° C., greater than 68° C., greater than 70° C., greater than 72° C., greater than 74° C., greater than 76° C., greater than 78° C., or greater than 80° C.

[0132] When an insufficient amount of stripping solution is used to immerse a given amount of composite, complete stripping of the composite may not occur. An example of this result is that a significant portion of the coating may still be found clinging to or adhering to the surface of the metal substrate. Using too much stripping solution does not present any particular disadvantages in terms of stripping effectiveness, but it does result in a waste of raw materials and may generate unnecessary, contaminated aqueous solvent waste, necessitating further processing steps to recycle the solvent. Therefore, there are no particular restrictions on the ratio of composite to stripping solution, other than that the ratio should be sufficient to strip all of the composite. Using an excessively large ratio of stripper to composite is not recommended for cost reasons.

[0133] 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 from about 0.01% to about 50%, from about 0.02% to about 50%, from about 0.05% to about 50%, from about 0.1% to about 50%, from about 0.2% to about 50%, from about 0.5% to about 50%, from about 1% to about 50%, from about 2% to about 50%, from about 5% to about 50%, from about 10% to about 50%, from about 15% to about 50%, from about 20% to about 50%, from about 25% to about 50%, from about 30% to about 50%, from 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%.

[0134] In some embodiments, when the composite is immersed in a stripping solution to achieve stripping of the composite, the weight ratio of the composite 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 composite is immersed in a stripping solution to achieve stripping of the composite, the weight ratio of the composite 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%.

[0135] The purpose of the stripping agent is to interrupt and disrupt the ion-dipole and hydrogen bonding interactions between the copolymer binder contained in the coating and the surface of the metal substrate. The concentration of the stripping agent in the stripping solution is crucial to achieving complete stripping of the coating from 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 be stripped. A relatively low concentration of stripping agent is sufficient to cause the disruption of the interaction between the copolymer binder in the coating and the surface of the metal substrate. Using a low concentration of stripping agent to immerse the composite can reduce the possibility of corrosion of the metal substrate and other possible metal parts in the composite and / or reduce side reactions that may be caused by using a high concentration of stripping agent.

[0136] In some embodiments, the concentration of the stripping agent in the stripping solution is about 17 mM to about 57 mM, about 19 mM to about 57 mM, about 20 mM to about 57 mM, about 21 mM to about 57 mM, about 23 mM to about 57 mM, about 25 mM to about 57 mM, about 27 mM to about 57 mM, about 29 mM to about 57 mM, about 31 mM to about 57 mM, about 33 mM to about 57 mM, about 35 mM to about 57mM, about 37mM to about 57mM, about 17mM to about 51mM, about 19mM to about 51mM, about 20mM to about 51mM, about 21mM to about 51mM, about 23mM to about 51mM, about 25mM to about 51mM, about 27mM to about 51mM, about 29mM to about 51mM, about 31mM to about 51mM, about 33mM to about 51mM, about 35mM to about 51mM, about 37mM to about 51mM, about 39mM to about 51mM, about 41mM to about 51mM, about 19mM to about 45mM, about 20mM to about 45mM, about 21mM to about 45mM, about 23mM to about 45mM, about 25mM to about 45mM, about 27mM to about 45mM, about 29mM to about 45mM, about 31mM to about 45mM, about 33mM to about 45 mM, about 35 mM to about 45 mM, about 19 mM to about 41 mM, about 20 mM to about 41 mM, about 21 mM to about 41 mM, about 23 mM to about 41 mM, about 25 mM to about 41 mM, about 27 mM to about 41 mM, about 29 mM to about 41 mM, about 31 mM to about 41 mM, about 21 mM to about 35 mM, about 23 mM to about 35 mM, or about 25 mM to about 35 mM.

[0137] In some embodiments, the concentration of the stripping agent in the stripping solution is less than 57 mM, less than 55 mM, less than 53 mM, less than 51 mM, less than 49 mM, less than 47 mM, less than 45 mM, less than 43 mM, less than 41 mM, less than 39 mM, less than 37 mM, less than 35 mM, less than 33 mM, less than 31 mM, less than 29 mM, less than 27 mM, less than 25 mM, less than 23 mM, or less than 21 mM. In some embodiments, the concentration of the stripping agent in the stripping solution is greater than 17 mM, greater than 19 mM, greater than 20 mM, greater than 21 mM, greater than 23 mM, greater than 25 mM, greater than 27 mM, greater than 29 mM, greater than 31 mM, greater than 33 mM, greater than 35 mM, greater than 37 mM, greater than 39 mM, greater than 41 mM, greater than 43 mM, greater than 45 mM, greater than 47 mM, greater than 49 mM, or greater than 51 mM.

[0138] In some embodiments, the surface density of the coating is about 1 mg / cm 2 to about 50mg / cm2 , about 2.5mg / cm 2 to about 50mg / cm 2 , about 5mg / cm 2 to about 50mg / cm 2 , about 7.5mg / cm 2 to about 50mg / cm 2 , about 10mg / cm 2 to about 50mg / cm 2 , about 12.5mg / cm 2 to about 50mg / cm 2 , about 15mg / cm 2 to about 50mg / cm 2 , about 17.5mg / cm 2 to about 50mg / cm 2 , about 20mg / cm 2 to about 50mg / cm 2 , about 25mg / cm 2 to about 50mg / cm 2 , about 30mg / cm 2 to about 50mg / cm 2 , about 1mg / cm 2 to about 30mg / cm 2 , about 2.5mg / cm 2 to about 30mg / cm 2 , about 5mg / cm 2 to about 30mg / cm 2 , about 7.5mg / cm 2 to about 30mg / cm 2 , about 10mg / cm 2 to about 30mg / cm 2 , about 12.5mg / cm 2 to about 30mg / cm 2 , about 15mg / cm 2 to about 30mg / cm 2 , about 17.5mg / cm 2 to about 30mg / cm 2 , about 20mg / cm 2 to about 30mg / cm 2 , about 1mg / cm 2 to about 20 mg / cm 2 , about 2.5mg / cm 2 to about 20 mg / cm 2 , about 5mg / cm 2 to about 20 mg / cm 2 , about 7.5mg / cm2 to about 20 mg / cm 2 , about 10mg / cm 2 to about 20 mg / cm 2 , about 12.5mg / cm 2 to about 20 mg / cm 2 , about 1mg / cm 2 to about 15 mg / cm 2 , about 2.5mg / cm 2 to about 15 mg / cm 2 , about 5mg / cm 2 to about 15 mg / cm 2 , about 7.5mg / cm 2 to about 15 mg / cm 2 or about 10 mg / cm 2 to about 15 mg / cm 2 .

[0139] In some embodiments, the surface density of the coating is less than 50 mg / cm 2 , less than 45mg / cm 2 , less than 35mg / cm 2 Less than 30mg / cm 2 , less than 25mg / cm 2 Less than 20mg / cm 2 , less than 17.5mg / cm 2 , less than 15mg / cm 2 , less than 12.5mg / cm 2 Less than 10mg / cm 2 , less than 7.5mg / 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 / cm 2 , greater than 2.5mg / cm 2 , greater than 5mg / cm 2 , greater than 7.5mg / cm 2 , greater than 10mg / cm 2 , greater than 12.5mg / cm 2 , greater than 15mg / cm 2 , greater than 17.5mg / cm 2 , greater than 20mg / cm 2 , greater than 25mg / cm 2 , greater than 30mg / cm 2 , greater than 35mg / cm 2 or greater than 40 mg / cm2 .

[0140] In some embodiments, the coating has a density of about 0.5 g / cm 3 to about 7.5g / cm 3 , about 1g / cm 3 to about 7.5g / cm 3 , about 1.5g / cm 3 to about 7.5g / cm 3 , about 2g / cm 3 to about 7.5g / cm 3 , about 2.5g / cm 3 to about 7.5g / cm 3 , about 3g / cm 3 to about 7.5g / cm 3 , about 3.5g / cm 3 to about 7.5g / cm 3 , about 4g / cm 3 to about 7.5g / cm 3 , about 4.5g / cm 3 to about 7.5g / cm 3 , about 5g / cm 3 to about 7.5g / cm 3 , about 0.5g / cm 3 to about 5g / cm 3 , about 1g / cm 3 to about 5g / cm 3 , about 1.5g / cm 3 to about 5g / cm 3 , about 2g / cm 3 to about 5g / cm 3 , about 2.5g / cm 3 to about 5g / cm 3 , about 3g / cm 3 to about 5g / cm 3 , about 0.5g / cm 3 to about 2.5g / cm 3 , about 1g / cm 3 to about 2.5g / cm 3 or about 1.5g / cm 3 to about 2.5g / cm 3 .

[0141] In some embodiments, the coating has a density of less than 7.5 g / cm 3 , less than 7g / cm 3 , less than 6.5g / cm 3 , less than 6g / cm 3 , less than 5.5g / cm3 , less than 5g / cm 3 , less than 4.5g / cm 3 , less than 4g / cm 3 , less than 3.5g / cm 3 , less than 3g / cm 3 , less than 2.5g / cm 3 , less than 2g / cm 3 or less than 1.5g / cm 3 In some embodiments, the coating has a density greater than 0.5 g / cm 3 , greater than 1g / cm 3 , greater than 1.5g / cm 3 , greater than 2g / cm 3 , greater than 2.5g / cm 3 , greater than 3g / cm 3 , greater than 3.5g / cm 3 , greater than 4g / cm 3 , greater than 4.5g / cm 3 , greater than 5g / cm 3 , greater than 5.5g / cm 3 , greater than 6g / cm 3 or greater than 6.5g / cm 3 .

[0142] In some embodiments, the composite-stripping solution mixture can be stirred while the composite is immersed in the stripping solution to achieve stripping of the composite. In some embodiments, the composite-stripping solution mixture is stirred using a planetary mixer, a stirring mixer, a blender, an ultrasonic generator, or a combination thereof. In other embodiments, the composite-stripping solution mixture is not stirred while the composite is immersed in the stripping solution.

[0143] In some embodiments, the speed of stirring the composite-stripping solution mixture is about 10 rpm to about 3000 rpm, about 20 rpm to about 3000 rpm, about 50 rpm to about 3000 rpm, about 100 rpm to about 3000 rpm, about 200 rpm to about 3000 rpm, about 250 rpm to about 3000 rpm, about 300 rpm to about 3000 rpm, about 400 rpm to about 3000 rpm, about 500 rpm to about 3000 rpm, about 600 rpm to about 3000 rpm, about 750 rpm to about 3000 rpm, about 900 rpm to about 3000 rpm, about 1200 rpm to about 3000 rpm, about 1500 rpm to about 3000 rpm, about 10 rpm to about 1000 rpm, about 20 rpm to about 1000 rpm, about 50 rpm to about 3000 rpm, about rpm to about 1000 rpm, about 100 rpm to about 1000 rpm, about 200 rpm to about 1000 rpm, about 250 rpm to about 1000 rpm, about 300 rpm to about 1000 rpm, about 400 rpm to about 1000 rpm, about 500 rpm to about 1000 rpm, about 10 rpm to about 750 rpm, about 20 rpm to about 750 rpm, about 50 rpm to about 750 rpm, about 100 rpm to about 750 rpm, about 200 rpm to about 750 rpm, about 250 rpm to about 750 rpm, about 300 rpm to about 750 rpm, about 10 rpm to about 500 rpm, about 20 rpm to about 500 rpm, about 50 rpm to about 500 rpm, about 100 rpm to about 500 rpm, or about 200 rpm to about 500 rpm.

[0144] In some embodiments, the speed of stirring the composite-stripping 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 speed of stirring the composite-stripping 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.

[0145] In some embodiments, the composite-stripping solution mixture is stirred for a period of time 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, from about 30 seconds to about 45 minutes. , about 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.

[0146] In some embodiments, the composite-stripping solution mixture is stirred for 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 composite-stripping solution mixture is stirred for 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.

[0147] In some embodiments, planetary stirring mixer comprises at least one planetary paddle and at least one high speed dispersion paddle.In certain embodiments, the rotating speed of planetary paddle is about 20rpm to about 200rpm, about 20rpm to about 150rpm, about 30rpm to about 150rpm or about 50rpm to about 100rpm.In certain embodiments, the rotating speed of dispersion paddle is about 1000rpm to about 4000rpm, about 1000rpm to about 3500rpm, about 1000rpm to about 3000rpm, about 1000rpm to about 2000rpm, about 1500rpm to about 3000rpm or about 1500rpm to about 2500rpm.

[0148] In certain embodiments, the ultrasonic generator is an ultrasonic bath, a probe-type ultrasonic generator, or an ultrasonic flow cell. In some embodiments, the ultrasonic generator is operated at a power density of 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 certain embodiments, the ultrasonic generator operates at a power density 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.

[0149] In some embodiments, the ultrasonic generator is operated at a power of about 100 W to about 1000 W, about 200 W to about 1000 W, about 300 W to about 1000 W, about 400 W to about 1000 W, about 500 W to about 1000 W, about 500 W to about 900 W, about 500 W to about 800 W, about 500 W to about 700 W, or about 500 W to about 600 W. In some embodiments, the ultrasonic generator is operated at a power of less than 1000 W, less than 900 W, less than 800 W, less than 700 W, less than 600 W, less than 500 W, less than 400 W, or less than 300 W. In some embodiments, the ultrasonic generator is operated at a power of greater than 100 W, greater than 200 W, greater than 300 W, greater than 400 W, greater than 500 W, greater than 600 W, greater than 700 W, or greater than 800 W.

[0150] In some embodiments, after immersing the composite in the stripping solution, the pH of the composite-stripping solution mixture after stripping is from about 9 to about 13, from about 9.25 to about 13, from about 9.5 to about 13, from about 9.75 to about 13, from about 10 to about 13, from about 10.25 to about 13, from about 10.5 to about 13, from about 10.5 to about 13, from about 10.5 to about 12.75, from about 10.5 to about 12.5, from about 10.5 to about 12.25, from about 10.5 to about 12, from about 10.5 to about 11.75, or from about 10.5 to about 11.5.

[0151] In some embodiments, after immersing the composite in the stripping solution, the pH of the composite-stripping solution mixture after stripping is less than 13, less than 12.75, less than 12.5, less than 12.25, less than 12, less than 11.75, less than 11.5, less than 11.25, less than 11, less than 10.75, less than 10.5, less than 10.25, less than 10, less than 9.75, or less than 9.5. In some embodiments, after immersing the composite in the stripping solution, the pH of the composite-stripping solution mixture after stripping is greater than 9, greater than 9.25, greater than 9.5, greater than 9.75, greater than 10, greater than 10.25, greater than 10.5, greater than 10.75, greater than 11, greater than 11.25, greater than 11.5, greater than 11.75, greater than 12, greater than 12.25, or greater than 12.5.

[0152] In some embodiments, after immersing the composite in the stripping solution, the composite is stripped into two or more layers. In some embodiments, after immersing the composite in the stripping solution, the composite is stripped into the coating layer and the metal substrate layer.

[0153] In some embodiments, the stripped composite-stripping solution mixture is screened to separate the coating and the metal substrate layer from the stripping solution. In some embodiments, filtering, sieving, decanting, or a combination thereof can be used to screen the stripped composite-stripping solution mixture.

[0154] Figure 3 FIG1 is a flow chart illustrating steps in a method 300 for stripping a composite disclosed herein and extracting the coating and metal substrate material for subsequent further processing. Because the metal substrates disclosed herein have a relatively low tendency to corrode and dissolve, the extracted stripping solution can be reused without purification. The extracted stripping solution can be reused for stripping other composites. This creates a closed-loop recycling process, where materials are repeatedly recovered and reused, continuing the cycle and contributing to a circular economy.

[0155] In some embodiments, the recovered stripped composite material may be subjected to additional separation and / or extraction processes to further extract the respective materials contained therein. In some embodiments, the recovered coating and metal substrate layers may be subjected to additional separation and / or extraction processes to further extract the coating and metal substrate materials.

[0156] The method of the present invention is particularly suitable for achieving exfoliation of electrodes in batteries, wherein the electrodes are composites, wherein the electrode layer and the current collector are a coating and a metal substrate, respectively.

[0157] 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, lithium-air batteries, aluminum-air batteries, zinc-air batteries, sodium-air batteries, silicon-air batteries, zinc-ion batteries, and sodium-sulfur batteries.

[0158] Within the electrode, a binder can be used to adhere the active material particles and the conductive agent to the current collector to form a continuous conductive path. Since the copolymer binder disclosed herein has excellent bonding ability, such a copolymer binder can be used. Due to the good bonding ability between the electrode layer components and between the electrode layer and the current collector, the use of such a copolymer binder helps to reduce the impedance and interfacial resistance between the current collector and the electrode material, thereby improving the ion and electron transport rate. In addition, the disclosed copolymer can easily interact with water through hydrogen bonding and ion-dipole interactions, so that the copolymer binder has excellent dispersibility and stability in water, and by using a water-based slurry, it has good processability when forming the electrode layer.

[0159] When recycling batteries, current methods for stripping the electrode layers from the current collectors have drawbacks, such as the high temperatures required and the release of hazardous substances when using calcination, or the use of dangerous and hazardous chemicals when using leaching.

[0160] In contrast, the stripping method disclosed herein allows 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, to be effectively stripped by simply using a stripping solution without significant safety concerns or environmental impacts. Furthermore, the stripping process is highly efficient.

[0161] Figure 4 The cathode layer and current collector recovered in Example 1 are described after immersing the double-sided coated cathode in a stripping solution, wherein the cathode comprises a copolymer binder and the stripping solution comprises sodium metasilicate at a concentration of 3 g / L and deionized water at 70°C. Delamination of the cathode layer from the aluminum current collector is visible, and no discoloration or pitting of the aluminum current collector is observed, indicating no significant corrosion of the aluminum current collector.

[0162] Figure 5The cathode recovered in Comparative Example 1 is described, wherein the double-sided coated cathode immersed in a stripping solution comprises polyvinylidene fluoride (PVDF) as a polymer binder. The stripping solution used herein is at 90°C and comprises sodium metasilicate and deionized water at a concentration of 3 g / L. It can be seen that stripping the cathode layer from the aluminum current collector is unsuccessful, and despite being immersed in the stripping solution at an elevated temperature, the cathode layer remains firmly adhered to the aluminum current collector. This indicates that the use of the stripping agent disclosed in the present invention for achieving electrode stripping is not suitable for electrodes comprising non-aqueous polymer binders (such as PVDF).

[0163] The current collector is used to collect electrons generated by the electrochemical reaction of the cathode active material or provide electrons required for the electrochemical reaction. In some embodiments, the current collector can be in the form of a foil, a sheet, or a 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 alloys thereof. 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.

[0164] In some embodiments, when the current collector comprises more than one layer, the current collector comprises a layer of insulating material. In some embodiments, the insulating material is a polymer material selected from the group consisting of polycarbonate, polyacrylate, polyacrylonitrile, polyester, polyamide, polystyrene, polyurethane, polyepoxy, poly(acrylonitrile butadiene styrene), polyimide, polyolefin, polyethylene, polypropylene, polyphenylene sulfide, poly(vinyl ester), polyvinyl chloride, polyether, polyphenylene ether, cellulosic polymers, and combinations thereof. When the current collector comprises a layer of insulating material, the coating is applied to the metal layer on the outside of the current collector.

[0165] In some embodiments, the current collector is coated with a layer of carbonaceous material. This layer of carbonaceous material will be part of the coating. In some embodiments, the current collector is not coated with a layer of carbonaceous material.

[0166] The thickness of the current collector affects the volume it occupies in the battery, the amount of electrode active material required, and thus the capacity of the battery. In some embodiments, the thickness of the current collector is from about 5 μm to about 50 μm, from about 10 μm to about 50 μm, from about 15 μm to about 50 μm, from about 20 μm to about 50 μm, from about 25 μm to about 50 μm, from about 5 μm to about 30 μm, from about 10 μm to about 30 μm, from about 15 μm to about 30 μm, from about 20 μm to about 30 μm, from about 5 μm to about 20 μm, from about 5 μm to about 15 μm, from about 10 μm to about 30 μm, from about 10 μm to about 25 μm, or from about 10 μm to about 20 μm.

[0167] 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.

[0168] In some embodiments, the electrode may be a cathode or an anode. In some embodiments, the electrode layer further comprises an electrode active material.

[0169] In some embodiments, the electrode active material is a cathode active material, wherein the cathode active material is selected from the group consisting of LiCoO2, LiNiO2, 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 certain embodiments, each x in the above 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 formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, 0 .2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875 and 0.9; each z in the above formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375 and 0.4. In some embodiments, each x, y and z in the above formula independently has an interval of 0.01.

[0170] In certain embodiments, the cathode active material is selected from the group consisting of LiCoO2, LiNiO2, 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 yO2 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 further embodiments, 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 certain embodiments, the cathode active material is Li 1+x Ni a Mn b Co c Al (1-a-b-c) O2; wherein -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, and 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; 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; and 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.

[0171] 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.

[0172] 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.

[0173] In other embodiments, the cathode active material is not LiCoO2, LiNiO2, LiMnO2, LiMn2O4 or Li2MnO3. In further embodiments, the cathode active material is not LiNi 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.

[0174] In certain embodiments, the cathode active material comprises or is itself a core-shell composite material having a core and shell structure, wherein the core and the shell each independently comprise a selected from the group consisting of 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 bO2 and combinations thereof, wherein -0.2≤x≤0.2, 0≤a<1, 0≤b<1, 0≤c<1, and a+b+c≤1. In certain embodiments, each x in the above 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 formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3 , 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875, 0.9, 0.925, 0.95 and 0.975; each 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 , 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 formula independently has a separation 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 comprises only one lithium transition metal oxide, while the other comprises 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, the two or more lithium transition metal oxides are uniformly distributed on the core. In certain embodiments, the two or more lithium transition metal oxides are unevenly distributed on the core. In some embodiments, the cathode active material is not a core-shell composite material.

[0175] 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 certain embodiments, the core and shell each independently comprise two or more doped lithium transition metal oxides. In some embodiments, the two or more doped lithium transition metal oxides are uniformly distributed over the core and / or shell. In certain embodiments, the two or more doped lithium transition metal oxides are non-uniformly distributed over the core and / or shell.

[0176] In some embodiments, the cathode active material comprises or is itself a core-shell composite material comprising a core comprising a lithium transition metal oxide and a shell comprising a transition metal oxide. In certain embodiments, the lithium transition metal oxide is selected from the group consisting of 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 bO2 and a group consisting of combinations thereof; wherein -0.2≤x≤0.2, 0≤a<1, 0≤b<1, 0≤c<1 and a+b+c≤1. In certain embodiments, x in the above 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 formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.1 75, 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 b in the above formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0. 7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875, 0.9, 0.925, 0.95 and 0.975; each c in the above formula is independently selected from 0, 0.025, 0.05, 0.075, 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,

[0177] , 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 formula independently has a separation 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 certain 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, or 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 certain embodiments, the shell has a thickness of 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 certain 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 certain 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 anode active material, wherein the anode active material is selected from natural graphite particles, synthetic graphite particles, hard carbon, soft carbon, mesocarbon microbeads (MCMB), Sn particles, SnO2, SnO, Li4Ti5O 12 particles, Si particles, Si-C composite particles and combinations thereof.

[0180] In certain embodiments, the anode active material is doped with a metal element or a non-metal element. In some embodiments, the metal 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-metal 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 having a core and shell structure, wherein the core and the shell are each independently selected from natural graphite particles, synthetic graphite particles, hard carbon, soft carbon, mesophase carbon microbeads (MCMB), Sn particles, SnO2, SnO, Li4Ti5O 12 particles, Si particles, Si-C composite particles and combinations thereof.

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

[0183] In certain embodiments, the anode active material is not doped with metal elements or non-metal elements. 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 further include other additives for enhancing 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 electrical 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 tubes, activated carbon, Super P, 0-dimensional KS6, one-dimensional vapor-grown carbon fibers (VGCF), mesoporous carbon, and combinations thereof.

[0186] In some embodiments, the electrode layer further comprises a lithium salt. The lithium salt helps 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(trifluoromethylsulfonyl)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(oxalato)borate (LiBF2C2O4), lithium dioxalatoborate (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 to 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, alkylene oxide 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), polyethylene carbonates (PECs), polyacrylamides (PAMs), polyethylene glycols (PEGs), polyethylene oxides (PEOs), polyhydroxyethyl methacrylates (P(HEMAs)), polyphosphonates (PPhs), polysiloxanes, polyamides (PAs), polydilactones, polydiesters, 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 resistance of the electrode. 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 0.166S4; Li4SnS4; B2S3-Li2S; 10 SnP2S 12 ; Li6PS5X argyrodite (where X is a halogen); sulfo-LISICON compounds, such as Li 3.25 Ge 0.25 P 0.75 S4; antiperovskites, such as Li3SX (X is Cl or Br); lithium-phosphorus-iodine-oxysulfide; lithium-phosphorus-oxysulfide; lithium-zinc-germanium sulfide; lithium-germanium sulfide; LLTO-based compounds, such as (La, Li)TiO3; Li6La2CaTa6O 12 ;Li6La2ANb2O 12 (A is Ca and / or Sr); Li2Nd3TeSbO 12 ;Li3BO 2.5 N 0.5 ;Li9SiAlO8; LAGP compound (Li 1+x Al x Ge 2-x (PO4)3, where 0≤x≤1, 0≤y≤1); Li2O-LATP compounds, such as Al2O3-TiO2-P2O5; Li 1+x Al x Ti 2-x (PO4)3(where 0≤x≤1, 0≤y≤1);Li 1+x Ti 2-x Al x Si y (PO4) 3-y (where 0≤x≤1, 0≤y≤1); LiAl x Zr 2-x (PO4)3 (where 0≤x≤1, 0≤y≤1); LiTi x Zr 2-x (PO4)3 (where 0≤x≤1, 0≤y≤1); LISICON type solid electrolyte; LIPON compound (Li 3+ y PO 4-x N x, wherein 0≤x≤1, 0≤y≤1); perovskite compounds ((La, Li)TiO3); NASICON compounds, such as LiTi2(PO4)3; antiperovskites, such as Li3OX (X is Cl or Br); lithium-aluminum-titanium-silicon-phosphate (LATSP); lithium-aluminum oxide; lithium-vanadium-germanium oxide; lithium-zinc-germanium oxide; lithium-filled garnets, such as lithium-lanthanum-zirconium oxide; lithium-lanthanum-zirconium-aluminum oxide; lithium-lanthanum-zirconium-tantalum oxide; Li3N; lithium-aluminum chloride and a group consisting of them.

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

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

[0191] In addition, the copolymer binder used in the present invention can demonstrate strong adhesion of the electrode layer to the current collector in the electrode. Having good peel strength between the electrode layer and the current collector is important because it significantly impacts the mechanical stability of the electrode and the cyclability of the battery. Therefore, the electrode should have sufficient peel strength to withstand the rigors of the battery manufacturing process.

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

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

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

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

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

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

[0198] In some embodiments, a battery comprising an electrode to be stripped is first disassembled into one or more battery fragments, wherein the one or more battery fragments comprise one or more electrode fragments. There is no particular limitation on the method for disassembling the battery, except that the minimum size of the resulting battery fragments should be larger than the mesh size of the sieve used to screen the composite-stripping solution mixture after stripping to ensure that these 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 subjected to a low-temperature treatment, such as using liquid nitrogen, before disassembly. In some embodiments, the battery is first discharged. In some embodiments, the battery is discharged by immersing in a salt solution. In other embodiments, when a water jet is used to disassemble the battery, and / or when the battery is subjected to a low-temperature treatment before disassembly, it is not necessary to discharge the battery.

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

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

[0201] In other embodiments, the electrode fragments are separated from the rest of the battery fragments after disassembly but before stripping. In some embodiments, only the electrode fragments are stripped after they are separated from the rest of the battery fragments.

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

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

[0204] The method of the present invention has a success rate of greater than 78% for stripping electrodes containing copolymer binders, a very high recovery rate (>98%), and allows the electrodes to be stripped from the current collector in a short time (~180s).

[0205] In some embodiments, electrode peeling occurs at the electrode layer-current collector interface. The peeling success rate refers to the degree to which the electrode layer peels from the current collector. The success rate can be calculated using the formula:

[0206]

[0207] After the stripping reaction, the weight of the electrode layer present in the stripping solution will be equivalent to the weight of the electrode layer that was successfully stripped. 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 the residual electrode layer and then weighing the scraped portion. In the present 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 the electrode layer is partially stripped from the current collector and there is still visible electrode layer adhesion remaining on the current collector, the success rate will be less than 100%.

[0208] The recovery rate refers to the proportion of the sum of the weights of the recovered electrode layer and current collector that are successfully extracted based on the initial weight of the electrode before immersion in the stripping solution. The recovery rate is calculated only when the success rate is greater than 75%, because below this value, the stripping is considered ineffective and economically unfeasible, and therefore not worth considering for application in industrial production. It reflects the degree of corrosion of useful metal materials in the electrode and / or the degree of solubility of useful metal materials in the stripping solution. The method disclosed in this article achieves a high recovery rate, indicating that the degree of corrosion or dissolution of the metal electrode material (such as the current collector) immersed in the stripping solution is negligible.

[0209] Taking into account the composition of the copolymer binder used, the present invention provides a simple method for stripping the electrode layer from the current collector. Since separation of the electrode layer and current collector is a key step in battery recycling, the method disclosed herein provides a technical solution to meet the needs of battery recycling. The method of the present invention avoids both complex separation processes and contamination of the current collector, while achieving excellent material recovery (i.e., high recovery rate).

[0210] The method disclosed in this invention significantly reduces the time required to strip an electrode layer from a current collector in a battery without damaging the underlying current collector. The short contact time between the electrode and the stripping solution can prevent corrosion of the current collector, electrode active material, and other metal electrode materials. For example, when an electrode containing an aluminum current collector is immersed in a stripping solution containing an alkali metal silicate, the short contact time allows the natural oxide layer formed on the surface of the aluminum current collector to provide sufficient corrosion protection.

[0211] The method of the present invention can also be used to strip a packaging material by immersing the packaging material in a stripping solution; wherein the packaging material comprises a metal and a coating applied to one or both sides of the metal, wherein the coating comprises a copolymer binder.

[0212] The coating can comprise metal, plastic, paper, or possibly cardboard. The metal and coating are separated from each other by treating the packaging material with a stripping solution containing an alkali metal silicate. The method disclosed herein can be used to strip a variety of packaging materials, particularly food and beverage packaging, to enable the recovery and recycling of each material component used in the packaging.

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

[0214] Example

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

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

[0217] The success rate of stripping refers to the degree to which the electrode layer is stripped from the current collector. It can be calculated by the formula:

[0218]

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

[0220] The adhesion strength of the dried adhesive layer was measured by a tensile tester (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 an angle of 180°. The average roughness depth (R z) is 2 μm. The copolymer adhesive is coated on 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. An 18 mm wide and 20 mm long tape (3M; United States; Model 810) is adhered to the surface of the adhesive layer. The adhesive strip is clamped on the testing machine, and the tape is then folded back at 180°, then placed in a movable jaw and pulled at a peeling speed of 300 mm / min at room temperature. The maximum peel force measured is taken as the adhesion strength. Repeat the measurement 3 times and take the average value.

[0221] The peel strength of the dried electrode layer was measured by a tensile tester (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 an angle of 180°. The average roughness depth (R z ) is 2 μm. A strip of adhesive tape (3M; USA; Model 810) 18 mm wide and 20 mm long was adhered to the surface of the cathode electrode layer. The cathode strip was clamped in a testing machine, and the tape was then folded back 180°, placed in the movable jaws, and pulled at a peel speed of 200 mm / min at room temperature. The maximum peel force measured was taken as the peel strength. The measurement was repeated three times and the average value was calculated.

[0222] Example 1

[0223] Assembly of soft-pack lithium-ion full batteries

[0224] A) Preparation of polymer binder

[0225] 7.45 g of sodium hydroxide (NaOH) was added to a round-bottom flask containing 380 g of distilled water. The mixture was stirred at 80 rpm for 30 minutes to obtain a first suspension.

[0226] 16.77 g of acrylic acid was added to the first suspension.The mixture was further stirred at 80 rpm for 30 minutes to obtain a second suspension.

[0227] 7.19 g of acrylamide was dissolved in 10 g of deionized water to form an acrylamide solution. Thereafter, 17.19 g of the acrylamide solution was added to the second suspension. The mixture was further heated to 55° C. and stirred at 80 rpm for 45 minutes to obtain a third suspension.

[0228] 35.95 g of acrylonitrile was added to the third suspension.The mixture was further stirred at 80 rpm for 10 minutes to obtain a fourth suspension.

[0229] Next, 0.015 g of a water-soluble free radical initiator (ammonium persulfate, APS; obtained from Aladdin Industries, China) was dissolved in 3 g of deionized water, and 0.0075 g of a 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 the APS solution and 1.5075 g of the sodium bisulfite solution were added to the fourth suspension. The mixture was stirred at 200 rpm at 55°C for 24 hours to obtain a fifth suspension.

[0230] After the reaction is complete, the temperature of the fifth suspension is reduced to 25°C. 3.72g of NaOH is dissolved in 400g of deionized water. Thereafter, 403.72g of sodium hydroxide solution is added dropwise to the fifth suspension to adjust the pH to 7.3 to form a sixth suspension. The sixth suspension is filtered using a 200μm nylon mesh to form a binder material. The solid content of the binder material is 8.88wt.%. The adhesion strength of the copolymer binder to the current collector is 3.41N / cm. The components of the copolymer binder of Example 1 and their respective proportions are shown in Table 1 below.

[0231] B) Preparation of the positive electrode

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

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

[0234] The homogenized cathode slurry was coated onto both sides of a 16 μm thick aluminum foil as a current collector using a knife coater with a gap width of 120 μm. The cathode electrode layer was formed by drying 80 μm of the coated slurry on the aluminum foil in an electrically heated oven at 85°C. The drying time was about 120 minutes. 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 / cm 2 .

[0235] C) Preparation of negative electrode

[0236] 93wt.% of graphite (BTR New Energy Materials Inc., Shenzhen, Guangdong, China) was mixed with 1wt.% of carboxymethyl cellulose (CMC, BSH-12, DKS Co. Ltd., Japan) and 3wt.% of SBR (AL-2001, NIPPON A&L, Japan) as a binder and 3wt.% of carbon black as a conductive agent in deionized water to prepare a negative electrode slurry. The solid content of the anode slurry was 51.5wt.%. The slurry was coated on both sides of a copper foil having a thickness of 8μm using a knife coater with a gap width of about 120μm. The coated slurry on the copper foil was dried at about 85°C for 120 minutes by a hot air dryer to obtain a negative electrode. The electrode was then pressed to reduce the thickness of the anode electrode layer to 60μm, and the surface density of the anode electrode layer was 10mg / cm 2 .

[0237] D) Assembly of soft pack batteries

[0238] After drying, the resulting cathode coating and anode coating were cut into rectangular sheets of 5.2 cm × 8.5 cm and 5.4 cm × 8.7 cm, respectively, to prepare cathode and anode sheets. Soft-pack batteries were prepared by alternately stacking the cathode and anode sheets and separating them with a porous polyethylene separator (Celgard, LLC, USA) with a thickness of 25 μm. The electrolyte was a solution containing LiPF6 (1 M) in a mixture of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC) in a volume ratio of 1:1:1. The battery was assembled in a high-purity argon environment with a moisture and oxygen content of <1 ppm. After injecting the electrolyte, the soft-pack battery was vacuum-sealed and then mechanically pressed using a punching tool with a standard shape.

[0239] The assembled pouch cell was then subjected to repeated charge and discharge cycles between 3.0V and 4.2V at a constant current rate of 1C 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.

[0240] Battery recycling

[0241] A) Discharging and disassembling of soft pack batteries

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

[0243] B) Preparation of stripping solution

[0244] 3.0 g of anhydrous sodium metasilicate (Sigma-Aldrich, USA) was added to 1000 g of deionized water to form a stripping solution with a concentration of 3 g / L.

[0245] C) Immerse the cathode in the stripping solution

[0246] 5.07 g of cathode was placed in a container containing 1000 g of stripping solution heated to 70°C. The cathode layer was separated from the aluminum foil. Once the cathode layer was observed to have been stripped, the stripping solution containing sodium metasilicate and deionized water was removed by passing it through a sieve with a mesh width of 4 mm to recover the cathode layer and aluminum foil. The stripping solution can be further reused to strip the electrode. The recovered cathode layer and aluminum foil were dried in an oven at 80°C for 5 hours under atmospheric pressure with a recovery rate of 98.12%. The stripping success rate and recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0247] Assembly of soft-pack lithium-ion full batteries of Examples 2-4

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

[0249] Recycling of the battery of Example 2

[0250] A) Discharging and disassembling of soft pack batteries

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

[0252] B) Preparation of stripping solution

[0253] 5.0 g of anhydrous sodium metasilicate (Sigma-Aldrich, USA) was added to 1000 g of deionized water to form a stripping solution with a concentration of 5 g / L.

[0254] C) Immerse the cathode in the stripping solution

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

[0256] Recycling of the battery of Example 3

[0257] The battery was recovered in the same manner as in Example 1, except that the stripping solution was heated to 60° C. The stripping success rate and recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0258] Recycling of the battery of Example 4

[0259] The battery was recovered in the same manner as in Example 1, except that the stripping solution was heated to 90° C. The stripping success rate and recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0260] Preparation of polymer binder of Example 5

[0261] 8.26 g of sodium hydroxide (NaOH) was added to a round-bottom flask containing 380 g of distilled water. The mixture was stirred at 80 rpm for 30 minutes to obtain a first suspension.

[0262] 18.22 g of acrylic acid was added to the first suspension.The mixture was further stirred at 80 rpm for 30 minutes to obtain a second suspension.

[0263] 5.75 g of acrylamide was dissolved in 10 g of deionized water to form an acrylamide solution. Thereafter, 15.75 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.

[0264] 35.96 g of acrylonitrile was added to the third suspension.The mixture was further stirred at 80 rpm for 10 minutes to obtain a fourth suspension.

[0265] Furthermore, 0.015 g of a water-soluble free radical initiator (ammonium persulfate, APS; purchased from Aladdin Industries, China) was dissolved in 3 g of deionized water, and 0.0075 g of a reducing agent (sodium bisulfite; purchased from Tianjin Damao Chemical Reagent Factory, China) was dissolved in 1.5 g of deionized water. 3.015 g of the APS solution and 1.5075 g of the sodium bisulfite solution were added to the fourth suspension. The mixture was stirred at 200 rpm at 55° C. for 24 hours to obtain a fifth suspension.

[0266] After the reaction is complete, the temperature of the fifth suspension is reduced to 25°C. 3.72 g of NaOH is dissolved in 400 g of deionized water. Thereafter, 403.72 g of sodium hydroxide solution is added dropwise to the fifth suspension to adjust the pH to 7.3 to form a sixth suspension. The sixth suspension is filtered using a 200 μm nylon mesh to form a binder material. The components of the copolymer binder of Example 5 and their respective proportions are shown in Table 1 below.

[0267] Preparation of polymer binder of Example 6

[0268] 5.42 g of sodium hydroxide (NaOH) was added to a round-bottom flask containing 380 g of distilled water. The mixture was stirred at 80 rpm for 30 minutes to obtain a first suspension.

[0269] 13.12 g of acrylic acid was added to the first suspension.The mixture was further stirred at 80 rpm for 30 minutes to obtain a second suspension.

[0270] 12.94 g of acrylamide was dissolved in 10 g of deionized water to form an acrylamide solution. Thereafter, 22.94 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.

[0271] 34.35 g of acrylonitrile was added to the third suspension.The mixture was further stirred at 80 rpm for 10 minutes to obtain a fourth suspension.

[0272] Furthermore, 0.015 g of a water-soluble free radical initiator (ammonium persulfate, APS; purchased from Aladdin Industries, China) was dissolved in 3 g of deionized water, and 0.0075 g of a reducing agent (sodium bisulfite; purchased from Tianjin Damao Chemical Reagent Factory, China) was dissolved in 1.5 g of deionized water. 3.015 g of the APS solution and 1.5075 g of the sodium bisulfite solution were added to the fourth suspension. The mixture was stirred at 200 rpm at 55°C for 24 hours to obtain a fifth suspension.

[0273] After the reaction is complete, the temperature of the fifth suspension is reduced to 25°C. 3.72 g of NaOH is dissolved in 400 g of deionized water. Thereafter, 403.72 g of sodium hydroxide solution is added dropwise to the fifth suspension to adjust the pH to 7.3 to form a sixth suspension. The sixth suspension is filtered using a 200 μm nylon mesh to form a binder material. The components of the copolymer binder of Example 6 and their respective proportions are shown in Table 1 below.

[0274] Preparation of polymer binder of Example 7

[0275] 9.07 g of sodium hydroxide (NaOH) was added to a round-bottom flask containing 380 g of distilled water. The mixture was stirred at 80 rpm for 30 minutes to obtain a first suspension.

[0276] 19.68 g of acrylic acid was added to the first suspension.The mixture was further stirred at 80 rpm for 30 minutes to obtain a second suspension.

[0277] 12.94 g of acrylamide was dissolved in 10 g of deionized water to form an acrylamide solution. Thereafter, 22.94 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.

[0278] 29.52 g of acrylonitrile was added to the third suspension.The mixture was further stirred at 80 rpm for 10 minutes to obtain a fourth suspension.

[0279] Furthermore, 0.015 g of a water-soluble free radical initiator (ammonium persulfate, APS; purchased from Aladdin Industries, China) was dissolved in 3 g of deionized water, and 0.0075 g of a reducing agent (sodium bisulfite; purchased from Tianjin Damao Chemical Reagent Factory, China) was dissolved in 1.5 g of deionized water. 3.015 g of the APS solution and 1.5075 g of the sodium bisulfite solution were added to the fourth suspension. The mixture was stirred at 200 rpm at 55°C for 24 hours to obtain a fifth suspension.

[0280] After the reaction is complete, the temperature of the fifth suspension is reduced to 25°C. 3.72 g of NaOH is dissolved in 400 g of deionized water. Thereafter, 403.72 g of sodium hydroxide solution is added dropwise to the fifth suspension to adjust the pH to 7.3 to form a sixth suspension. The sixth suspension is filtered using a 200 μm nylon mesh to form a binder material. The components of the copolymer binder of Example 7 and their respective proportions are shown in Table 1 below.

[0281] Preparation of polymer binder of Example 8

[0282] 6.23 g of sodium hydroxide (NaOH) was added to a round-bottom flask containing 380 g of distilled water. The mixture was stirred at 80 rpm for 30 minutes to obtain a first suspension.

[0283] 14.58 g of acrylic acid was added to the first suspension.The mixture was further stirred at 80 rpm for 30 minutes to obtain a second suspension.

[0284] 5.75 g of acrylamide was dissolved in 10 g of deionized water to form an acrylamide solution. Thereafter, 15.75 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.

[0285] 38.64 g of acrylonitrile was added to the third suspension.The mixture was further stirred at 80 rpm for 10 minutes to obtain a fourth suspension.

[0286] Furthermore, 0.015 g of a water-soluble free radical initiator (ammonium persulfate, APS; purchased from Aladdin Industries, China) was dissolved in 3 g of deionized water, and 0.0075 g of a reducing agent (sodium bisulfite; purchased from Tianjin Damao Chemical Reagent Factory, China) was dissolved in 1.5 g of deionized water. 3.015 g of the APS solution and 1.5075 g of the sodium bisulfite solution were added to the fourth suspension. The mixture was stirred at 200 rpm at 55° C. for 24 hours to obtain a fifth suspension.

[0287] After the reaction is complete, the temperature of the fifth suspension is lowered to 25°C. 3.72 g of NaOH is dissolved in 400 g of deionized water. Thereafter, 403.72 g of sodium hydroxide solution is added dropwise to the fifth suspension to adjust the pH to 7.3 to form a sixth suspension. The sixth suspension is filtered using a 200 μm nylon mesh to form a binder material. The components of the copolymer binder of Example 8 and their respective proportions are shown in Table 1 below.

[0288] Assembly of soft-pack lithium-ion full batteries of Examples 5-8

[0289] A) Preparation of the positive electrode

[0290] The positive electrodes were prepared by the method described in Example 1, except that the cathodes of Examples 5-8 were prepared using the binder materials prepared in Examples 5-8, respectively.

[0291] B) Preparation of negative electrode

[0292] The negative electrode was prepared by the method described in Example 1.

[0293] C) Assembly of soft pack batteries

[0294] A pouch-type lithium-ion battery was prepared by the method described in Example 1. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 1.

[0295] Recycling of Batteries of Examples 5-8

[0296] The battery was recovered in the same manner as in Example 1. The stripping success rate and recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0297] Assembly of the soft-pack lithium-ion full battery of Example 9

[0298] A pouch-type lithium-ion battery was prepared by the method described in Example 1. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 1.

[0299] Recovery of the battery of Example 9

[0300] A) Discharging and disassembling of soft pack batteries

[0301] The spent lithium-ion batteries were discharged and disassembled by the same method described in Example 1.

[0302] B) Preparation of stripping solution

[0303] 3.0 g of anhydrous potassium metasilicate (Sigma-Aldrich, USA) was added to 1000 g of deionized water to form a stripping solution with a concentration of 3 g / L.

[0304] C) Immerse the cathode in the stripping solution

[0305] The cathode was immersed and stripped by the method described in Example 1, except that the above-described stripping solution was used. The stripping success rate and recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0306] Assembly of the soft-pack lithium-ion full battery of Example 10

[0307] A pouch-type lithium-ion battery was prepared by the method described in Example 1, except that the same weight of LCO was used instead of 276 g of NMC532. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 1.

[0308] Assembly of the soft-pack lithium-ion full battery of Example 11

[0309] A pouch-type lithium-ion battery was prepared by the method described in Example 1, 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 1.

[0310] Assembly of the soft-pack lithium-ion full battery of Example 12

[0311] A pouch-type lithium-ion battery was prepared by the method described in Example 1, except that 23.30 g of 2-ethylacrylic acid was used instead of 16.77 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 1.

[0312] Assembly of the soft-pack lithium-ion full battery of Example 13

[0313] A pouch-type lithium-ion battery was prepared by the method described in Example 1, except that 25.16 g of vinyl sulfonic acid was used instead of 16.77 g of acrylic acid in the second suspension when preparing the polymer binder. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 1.

[0314] Recycling of Batteries of Examples 10-13

[0315] The battery was recovered in the same manner as in Example 1. The stripping success rate and recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0316] Assembly of the soft-pack lithium-ion full battery of Comparative Example 1

[0317] A) Preparation of the positive electrode

[0318] In a 500 mL round-bottom flask, 10 g of polyvinylidene fluoride (PVDF) as a polymer binder was added. A first suspension was prepared by dispersing 5130, purchased from Solvay, Belgium) in 250 g of NMP (≥99%, Sigma-Aldrich, USA) while stirring with an overhead stirrer at 500 rpm for about 3 hours.

[0319] Thereafter, 15 g of SuperP was added to the first suspension and stirred at 1200 rpm for 30 minutes to obtain a second suspension.

[0320] A third suspension was prepared by dispersing 225 g of NMC532 into the second suspension at 25° C. while stirring with an overhead stirrer. The third suspension was then degassed at a pressure of approximately 10 kPa for 1 hour. The third suspension was further stirred at 1200 rpm for approximately 90 minutes at 25° C. to form a homogenized cathode slurry.

[0321] The homogenized cathode slurry was applied to both sides of a 16 μm thick aluminum foil, serving as the current collector, using a knife coater with a gap width of 120 μm. The 80 μm layer of slurry applied to the aluminum foil was dried in an electrically heated oven at 85°C to form a 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.

[0322] B) Preparation of negative electrode

[0323] The negative electrode was prepared in the same manner as in Example 4.

[0324] C) Assembly of soft pack batteries

[0325] The pouch cell was assembled in the same manner as in Example 4. The assembled pouch cell was then repeatedly cycled in the same manner as in Example 4.

[0326] Recycling of batteries in Comparative Example 1

[0327] The battery was recovered in the same manner as in Example 4, except that if the stripping was incomplete, the reaction was terminated after 25 minutes. The stripping success rate and recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0328] Assembly of the soft-pack lithium-ion full battery of Comparative Examples 2-7

[0329] A pouch-type lithium-ion battery was prepared by the method described in Example 1. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 1.

[0330] Recycling of batteries in Comparative Example 2

[0331] The battery was recovered using the same method as in Example 1, except that no stripping agent was added to the stripping solution, and only 1000 g of deionized water was added. If stripping was incomplete, the reaction was terminated after 25 minutes. The success rate and recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0332] Recycling of the battery of Comparative Example 3

[0333] A) Discharging and disassembling of soft pack batteries

[0334] The spent lithium-ion batteries were discharged and disassembled by the same method described in Example 1.

[0335] B) Preparation of stripping solution

[0336] 2.0 g of anhydrous sodium metasilicate (Sigma-Aldrich, USA) was added to 1000 g of deionized water to form a stripping solution with a concentration of 2 g / L.

[0337] C) Immerse the cathode in the stripping solution

[0338] The cathode was immersed and stripped using the method described in Example 1, except that the above-described stripping solution was used. If stripping was incomplete, the reaction was terminated after three minutes. The stripping success rate and recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0339] Recycling of the battery of Comparative Example 4

[0340] A) Discharging and disassembling of soft pack batteries

[0341] The spent lithium-ion batteries were discharged and disassembled by the same method described in Example 1.

[0342] B) Preparation of stripping solution

[0343] 7.0 g of anhydrous sodium metasilicate (Sigma-Aldrich, USA) was added to 1000 g of deionized water to form a stripping solution with a concentration of 7 g / L.

[0344] C) Immerse the cathode in the stripping solution

[0345] The cathode was immersed and stripped using the method described in Example 1, except that the above-described stripping solution was used. If stripping was incomplete, the reaction was terminated after three minutes. The stripping success rate and recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0346] Recovery of the battery of Comparative Example 5

[0347] A) Discharging and disassembling of soft pack batteries

[0348] The spent lithium-ion batteries were discharged and disassembled by the same method described in Example 1.

[0349] B) Preparation of stripping solution

[0350] 11.0 g of anhydrous sodium metasilicate (Sigma-Aldrich, USA) was added to 1000 g of deionized water to form a stripping solution with a concentration of 11 g / L.

[0351] C) Immerse the cathode in the stripping solution

[0352] The cathode was immersed and stripped using the method described in Example 1, except that the above-described stripping solution was used. If stripping was incomplete, the reaction was terminated after three minutes. The stripping success rate and recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0353] Recovery of the battery of Comparative Example 6

[0354] The battery was recovered using the same method as in Example 1, except that the stripping solution was heated to 25°C. If the stripping was incomplete, the reaction was terminated after three minutes. The stripping success rate and recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0355] Recovery of the battery of Comparative Example 7

[0356] The battery was recovered using the same method as in Example 1, except that the stripping solution was heated to 50°C. If the stripping was incomplete, the reaction was terminated after three minutes. The stripping success rate and recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0357] Assembly of the soft-pack lithium-ion full battery of Comparative Example 8

[0358] A pouch-type lithium-ion battery was prepared by the method described in Example 1, except that, when preparing the polymer binder, 9.47 g of sodium hydroxide was added when preparing the first suspension, 20.41 g of acrylic acid was added when preparing the second suspension, no acrylamide was added when preparing the third suspension, and 38.64 g of acrylonitrile was added when preparing the fourth suspension. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 1.

[0359] Assembly of the soft-pack lithium-ion full battery of Comparative Example 9

[0360] A pouch-type lithium-ion battery was prepared by the method described in Example 1, except that, when preparing the polymer binder, 2.19 g of sodium hydroxide was added when preparing the first suspension, 7.29 g of acrylic acid was added when preparing the second suspension, 12.94 g of acrylamide was added when preparing the third suspension, and 38.64 g of acrylonitrile was added when preparing the fourth suspension. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 1.

[0361] Recycling of Batteries of Comparative Examples 8-9

[0362] The battery was recovered in the same manner as in Example 1, except that if the stripping was incomplete, the reaction was terminated after three minutes. The stripping success rate and recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0363] Assembly of the soft-pack lithium-ion full battery of Comparative Example 10

[0364] A pouch-type lithium-ion battery was prepared by the method described in Example 1. The assembled pouch-type battery was then repeatedly cycled in the same manner as in Example 1.

[0365] Recovery of the battery of Comparative Example 10

[0366] A) Discharging and disassembling of soft pack batteries

[0367] The spent lithium-ion batteries were discharged and disassembled by the same method described in Example 1.

[0368] B) Preparation of stripping solution

[0369] 2.0 g of anhydrous sodium acetate (Sigma-Aldrich, USA) was added to 1000 g of deionized water to form a stripping solution with a concentration of 2 g / L.

[0370] C) Immerse the cathode in the stripping solution

[0371] The cathode was immersed and stripped using the method described in Example 1, except that the above-described stripping solution was used. If stripping was incomplete, the reaction was terminated after 25 minutes. The stripping success rate and recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0372]

[0373] Although the present invention has been described in conjunction with a limited number of embodiments, the particular features of one embodiment should not limit the 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 is substantially free of any steps not enumerated herein. There are variations and modifications based on the described embodiments. 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 stripping a composite by immersing the composite in a stripping solution, wherein the composite comprises a metal substrate and a coating applied to one or both sides of the metal substrate, wherein the coating comprises a copolymer binder, wherein the copolymer binder comprises a structural unit a derived from a monomer selected from the group consisting of a carboxylic acid group-containing monomer, a sulfonic acid group-containing monomer, a phosphonic acid group-containing monomer, a carboxylate group-containing monomer, a sulfonate group-containing monomer, a phosphonate group-containing monomer, and a combination thereof, wherein the structural unit a in the copolymer accounts for 15 to 30% by mole based on the total molar number of monomer units in the copolymer binder, wherein the copolymer further comprises a structural unit b derived from a monomer selected from the group consisting of an amide group-containing monomer, a hydroxyl group-containing monomer, a The present invention relates to a copolymer comprising a monomer selected from the group consisting of monomers containing a nitrile group and combinations thereof, wherein the proportion of the structural unit b in the copolymer is 5% to 20% by mole based on the total moles of the monomer units in the copolymer binder, wherein the copolymer further comprises a structural unit c, wherein the structural unit c is derived from a monomer selected from the group consisting of monomers containing a nitrile group, monomers containing an ester group, monomers containing an epoxy group, fluorine-containing monomers and combinations thereof, wherein the proportion of the structural unit c in the copolymer is 50% to 75% by mole based on the total moles of the monomer units in the copolymer binder, wherein the stripping solution comprises a stripping agent and an aqueous solvent, wherein the stripping agent is a water-soluble alkali metal silicate, and wherein the temperature for immersing the composite in the stripping solution is 51° C. to 90° C. 2 . The method according to claim 1 , wherein the concentration of the stripping agent in the stripping solution is 17 to 57 mM.

3. The method according to claim 2, wherein the stripping agent is a stripping agent having the general formula (M2O) x (SiO2) y An alkali metal silicate, wherein M represents an alkali metal selected from the group consisting of sodium, potassium, rubidium, cesium and combinations thereof, and wherein the ratio between x and y is between 1:0.485 and 1:2.

76.

4. The method of claim 3, wherein the alkali metal silicate is further selected from the group consisting of sodium metasilicate, sodium orthosilicate, sodium disilicate, potassium metasilicate, potassium orthosilicate, potassium disilicate, rubidium metasilicate, rubidium orthosilicate, rubidium disilicate, cesium metasilicate, cesium orthosilicate, cesium disilicate, and combinations thereof. The method according to claim 2 , wherein the aqueous solvent is water.

6. The method according to claim 2, wherein the aqueous solvent comprises water as a main component and a secondary component, wherein the proportion of water in the aqueous solvent is greater than 51% and less than 100% by weight, and wherein the secondary component is selected from the group consisting of methanol, ethanol, isopropyl alcohol, n-propyl alcohol, tert-butyl alcohol, n-butyl alcohol, acetone, dimethyl ketone, methyl ethyl ketone, ethyl acetate, isopropyl acetate, propyl acetate, butyl acetate, and combinations thereof.

7. The method according to claim 1, wherein the monomer containing a carboxylic acid group is selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, 2-butyl crotonic acid, cinnamic acid, maleic acid, fumaric acid, itaconic acid, 4,4-dimethylitaconic acid, 2-ethylacrylic acid, isocrotonic acid, cis-2-pentenoic acid, trans-2-pentenoic acid, angelic acid, tiglic acid, 3,3-dimethylacrylic acid, 3-propylacrylic acid, trans-2-methyl-3-ethylacrylic acid, cis-2-methyl-3-ethylacrylic acid, Acrylic acid, 3-isopropylacrylic acid, trans-3-methyl-3-ethylacrylic acid, cis-3-methyl-3-ethylacrylic acid, 2-isopropylacrylic acid, trimethylacrylic acid, 2-methyl-3,3-diethylacrylic acid, 3-butylacrylic acid, 2-butylacrylic acid, 2-pentylacrylic acid, 2-methyl-2-hexenoic acid, trans-3-methyl-2-hexenoic acid, 3-methyl-3-propylacrylic acid, 2-ethyl-3-propylacrylic acid, 2,3-diethylacrylic acid, 3,3- Diethylacrylic acid, 3-methyl-3-hexylacrylic acid, 3-methyl-3-tert-butylacrylic acid, 2-methyl-3-pentylacrylic acid, 3-methyl-3-pentylacrylic acid, 4-methyl-2-hexenoic acid, 4-ethyl-2-hexenoic acid, 3-methyl-2-ethyl-2-hexenoic acid, 3-tert-butylacrylic acid, 2,3-dimethyl-3-ethylacrylic acid, 3,3-dimethyl-2-ethylacrylic acid, 3-methyl-3-isopropylacrylic acid, 2-methyl-3-isopropylacrylic acid , trans-2-octenoic acid, cis-2-octenoic acid, trans-2-decenoic acid, α-acetoxyacrylic acid, β-trans-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 and combinations thereof.

8. The method according to claim 1, wherein the monomer containing a carboxylate group is selected from the group consisting of acrylate, methacrylate, crotonate, 2-butylcrotonate, cinnamate, maleate, fumarate, itaconate, 4,4-dimethylitaconate, 2-ethylacrylate, isocrotonate, cis-2-pentenoate, trans-2-pentenoate, angelate, tiglate, 3,3-dimethylacrylate, 3-propylacrylate, trans-2-methyl-3-ethylacrylate, 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, trimethylacrylate, 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 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- The group consisting of ethyl acrylate, 3-methyl-3-isopropyl acrylate, 2-methyl-3-isopropyl acrylate, trans-2-octenoate, cis-2-octenoate, trans-2-decenoate, α-acetoxyacrylate, β-trans-aryloxyacrylate, α-chloro-β-E-methoxyacrylate, methylmaleate, dimethylmaleate, phenylmaleate, bromomaleate, chloromaleate, dichloromaleate, fluoromaleate, difluoromaleate and combinations thereof.

9. The method according to claim 1, wherein the sulfonic acid group-containing monomer is selected from the group consisting of vinyl sulfonic acid, methylvinyl sulfonic acid, allylvinyl sulfonic acid, allyl sulfonic acid, methylallyl sulfonic acid, styrene sulfonic acid, 2-sulfoethyl methacrylic acid, 2-methyl-2-propene-1-sulfonic acid, 2-acrylamido-2-methyl-1-propanesulfonic acid, 3-allyloxy-2-hydroxy-1-propanesulfonic acid, allyl hydrogen sulfate, vinyl hydrogen sulfate, and combinations thereof.

10. The method of claim 1 , wherein the sulfonate group-containing monomer 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 of claim 1 , wherein the monomer containing a phosphonic acid group is selected from the group consisting of vinylphosphonic acid, allylphosphonic acid, vinylbenzylphosphonic acid, acrylamidoalkylphosphonic acid, methacrylamidoalkylphosphonic acid, acrylamidoalkyldiphosphonic acid, acrylphosphonic acid, 2-methacryloyloxyethylphosphonic acid, bis(2-methacryloyloxyethyl)phosphonic acid, ethylene 2-methacryloyloxyethylphosphonic acid, ethyl-methacryloyloxyethylphosphonic acid, allyl hydrogen phosphate, vinyl hydrogen phosphate, and combinations thereof.

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

13. The method according to claim 1, wherein the amide group-containing monomer is selected from the group consisting of 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)methyl acrylamide, N-(propyloxymethyl)methacrylamide, N-(butoxymethyl)methacrylamide, N,N-dimethylmethacrylamide, N-(3-(dimethylamino)propyl)methacrylamide, N-(2-(dimethylamino)ethyl)methacrylamide, N,N-(dihydroxymethyl)methacrylamide, diacetone methacrylamide, diacetone acrylamide, methacryl morpholine, N-hydroxymethylacrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, N,N′-methylenebisacrylamide (MBA), N-hydroxymethylacrylamide, and combinations thereof.

14. The method of claim 1 , wherein the nitrile group-containing monomer 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.

15. The method of claim 1 , wherein the metal substrate is in the form of a foil, a sheet, a film, or a combination thereof, wherein 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.

16. The method according to claim 1, wherein the metal substrate is in the form of a porous body having a three-dimensional network structure, wherein the metal substrate is selected from the group consisting of stainless steel, titanium, nickel, aluminum, copper, platinum, gold, silver, chromium, zirconium, tungsten, molybdenum, tin, vanadium, zinc, cadmium, iron, cobalt, lead and alloys thereof. 17 . The method according to claim 1 , wherein a weight ratio of the composite to the stripping solution is 0.01% to 50%.

Images