Method for delaminating composite materials

Abstract

The present invention provides a method for stripping a composite material by immersing the composite material in a stripping solution, the composite material comprising a metal substrate and a coating applied to one or both sides of the metal substrate, the coating comprising a polymer binder, the polymer binder comprising an aqueous copolymer. By using a stripping solution containing a strong base, the composite material can be completely stripped in a highly efficient and extremely rapid manner. Furthermore, the stripping method disclosed herein avoids complicated separation processes and contamination or corrosion of the metal substrate, allowing for excellent material recovery. The application of the stripping method to battery electrodes is disclosed herein.

Description

[Technical Field]

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

[0002] Rapid urbanization, rapid technological advancements, and the resulting frequent replacement of products or disposal of consumables have led to shorter product lifespans and / or excessive waste generation. This excessive waste generation exacerbates problems such as adverse effects on human health, environmental damage, and resource depletion, making it urgently necessary worldwide to address these issues through various waste management methods.

[0003] Recycling is a crucial component in the hierarchical structure of waste reduction, aiming to recover and reuse valuable materials from waste. Material recycling contributes to the conservation of natural resources, reduction of energy consumption associated with raw material extraction (and consequently, reduction of production costs), and reduction of greenhouse gases and SO2. x Reducing emissions leads to a reduction in environmental impact. Because material recycling offers such significant benefits, developing highly efficient material recycling methods is crucial for achieving a circular economy.

[0004] The term "composite material" refers to a metal substrate coated on one or both sides, where the coating includes a polymer binder. The polymer binder is responsible for adhesion between the coating and the metal substrate. Coating metal substrates is a method of altering surface properties to meet performance requirements in various technical applications. Applications of coatings include adhesion, barrier formation, scratch resistance, abrasion resistance, chemical resistance, wettability, and biocompatibility. Coating metal substrates have frequently been used in battery manufacturing, membrane technology, packaging materials, printed circuit boards, wiring or cables, and biomedical applications. Separating the coating from the metal substrate is a technique significantly related to material recycling.

[0005] However, when immediately recycling products that have reached the end of their service life or have failed the manufacturing process, separating the composite materials contained within the product into coatings and metal substrates during recycling presents several challenges.

[0006] In some respects, composite materials may delaminate within the bulk of the coating rather than at the coating-metal substrate interface. Part of the coating may remain on the metal substrate, failing to delaminate completely. This results in undesirable loss of coating material that cannot be directly recovered during the delamination process, and a regenerated metal substrate with high levels of impurities due to residual coating, requiring subsequent separation processes.

[0007] In another respect, stripping coatings from metal substrates is highly inefficient and can take up to several hours. Prolonged exposure of composite materials to extreme stripping conditions can lead to corrosion, dissolution, and damage of materials within the composite, particularly the metal substrate, as well as side reactions such as the formation of by-reaction products.

[0008] Commonly used polymer binders, such as polyvinylidene fluoride (PVDF), which are responsible for bonding coatings to metal substrates, have the disadvantage of being insoluble in water. In fact, polymer binders can only be dissolved in certain organic solvents, such as N-methyl-2-pyrrolidone (NMP). Since NMP is flammable and toxic, it requires special handling. An NMP recovery system must be installed in the drying process to recover NMP vapors. Installing such a recovery system requires a large capital investment, thus incurring significant costs in the manufacturing process. Therefore, in applications where exposure to moisture during the manufacturing process is not a major concern, the use of polymer binders with cheaper and more environmentally friendly aqueous solvents, such as the most common water, is considered preferable in this invention because it reduces the significant capital costs of the recovery system.

[0009] Polymer binders suitable for use in aqueous coatings exhibit excellent dispersibility and stability in water, promoting extremely strong coating-metal substrate adhesion. However, when using such polymer binders, the strong adhesion between the coating and the metal substrate makes peeling the aqueous coating from the metal substrate extremely difficult. To further optimize the properties of these aqueous binders, copolymers containing structural units derived from various different monomers have been employed, but when these copolymer binders are used in coatings, peeling still presents considerable challenges.

[0010] Delamination of composite materials is achieved at the coating-metal substrate interface through the breakdown and / or fracture of the bonds between the polymer binder in the coating and the metal substrate. Therefore, in order to induce delamination at high speed, with high recovery rate and high safety, while using less additional material and requiring low costs, it is a crucial objective to more efficiently break and / or fracture the bonds between the polymer binder in the coating and the metal substrate.

[0011] Attempts have been made to develop methods for completely separating composite materials. KR Patent Application Publication No. 20130099568A discloses a method for separating composite materials, including a polymer film coated on a metal surface, by carbonizing the polymer using electromagnetic induction. First, the metal-polymer composite material is pre-treated by charging it into an induction furnace so that it is most affected by the magnetic density per unit area during induction heating and the movement of electrons on the metal surface becomes more active. Through induction heating, the metal-polymer composite material is heated to 500-900°C, weakening the bond between the polymer and the metal surface, inducing thermal decomposition, and causing carbonization of the polymer coated on the metal surface, making it easy to separate. This method achieves significant energy savings by employing induction heating. However, this proposed method results in polymer carbonization that makes polymer regeneration impossible. Furthermore, hazardous or toxic contaminants may be generated during the polymer decomposition process.

[0012] Considering the above challenges, there has always been a need to develop a unified and simple method for achieving highly efficient and complete delamination of composite materials at the interface between the coating and the metal substrate, where the composite material coating contains a polymer binder, and the polymer binder is a copolymer. The method for delaminating composite materials disclosed herein has been developed to achieve effective bond fracture and / or breakage between the copolymer binder and the metal substrate in the composite material coating. Therefore, a delamination method that meets these qualities is applicable to composite materials containing copolymer binders. Such a method avoids both complex separation steps and contamination of the metal substrate, enables excellent material recovery, and allows for the delamination of composite materials in a short time. [Prior art documents] [Patent Documents]

[0013] [Patent Document 1] KR Patent Application Publication No. 20130099568A [Overview of the Initiative]

[0014] The aforementioned needs are met by various aspects and embodiments disclosed herein. In one aspect, provided herein is a method for stripping a composite material by immersion in a stripping solution, wherein the composite material comprises a metal substrate and a coating applied to one or both sides of the metal substrate, the coating comprising a copolymer binder.

[0015] 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.

[0016] In some embodiments, the stripping solution comprises a stripping agent and an aqueous solvent.

[0017] In some embodiments, the stripping agent is a base. In some embodiments, the base is selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, lithium oxide, sodium oxide, potassium oxide, rubidium oxide, cesium oxide, calcium oxide, strontium oxide, barium oxide, and combinations thereof.

[0018] The delamination of composite materials achieved using the methods provided herein is very fast and easy, and does not suffer disadvantages in terms of irrecoverable loss of coating material, damage to the coating material, or introduction of impurities into the metal substrate.

[0019] In another embodiment, as one application of the present invention, the method described above is employed for stripping a battery electrode, where the composite material is the battery electrode, the metal substrate is the current collector, and the coating is the electrode layer. Provided herein is a method for stripping a battery electrode by immersing the electrode in a stripping solution; the electrode comprises a current collector and an electrode layer coated on one or both sides of the current collector; and the electrode layer comprises a copolymer binder.

[0020] The simple use of the stripping solution of the present invention for stripping battery electrodes at the electrode layer-current collector interface significantly reduces the time required to achieve complete stripping, maximizes the recovery of valuable materials, eliminates contamination of the current collector, and does not require subsequent downstream processes. Furthermore, the method disclosed herein has been found to be applicable to stripping both cathodes and anodes without concern for corrosion of the current collector and / or electrode active material within the electrode layer. [Brief explanation of the drawing]

[0021] [Figure 1] Figure 1 is a simplified diagram of one embodiment of a composite material. [Figure 2] Figure 2 is a schematic diagram of the proposed coating-metal substrate interface structure for the composite material. [Figure 3] Figure 3 is a flowchart of one embodiment showing the steps for stripping a composite material disclosed herein and subsequent further processing to extract the composite material components, namely the coating and the metal substrate, following the stripping of the composite material. [Figure 4] Figure 4 shows the recovered cathode layer and current collector of Example 2 after immersion of the double-sided coated cathode in the stripping solution, the stripping solution containing 0.1 M sodium hydroxide and deionized water (DI water), and the double-sided coated cathode containing a copolymer binder. [Figure 5] Figure 5 shows the recovered cathode from Comparative Example 1, where the stripping solution contains 0.1 M sodium hydroxide and DI water, and the double-sided coated cathode contains polyvinylidene fluoride (PVDF) as a polymer binder.

[0022] (Detailed description of the invention) In one embodiment, the foregoing provides a method for stripping a composite material by immersion in a stripping solution; wherein the composite material comprises a metal substrate and a coating applied to one or both sides of the metal substrate; and the coating comprises a copolymer binder.

[0023] In another embodiment, provided herein is a method for stripping a lithium-ion battery electrode by immersing the electrode in a stripping solution; the electrode comprises a current collector and an electrode layer coated on one or both sides of the current collector; and the electrode layer comprises a copolymer binder.

[0024] The term "electrode" refers to either the "cathode" or the "anode."

[0025] The term "positive electrode" is used interchangeably with "cathode." Similarly, the term "negative electrode" is used interchangeably with "anode."

[0026] The term “binder” or “binder material” refers to a chemical compound, mixture of compounds, or polymer used to hold materials in place and bond them onto a conductive metal substrate to form a composite material. In some embodiments, the binder refers to a chemical compound, mixture of compounds, or polymer used to hold electrode materials and / or conductive agents in place and bond them onto a conductive metal portion to form an electrode. In some embodiments, the electrode does not contain any conductive agent.

[0027] The term "conductive agent" refers to a material that possesses good conductivity. Therefore, to improve the conductivity of electrodes, conductive agents are often mixed with the electrode active material during electrode formation. In some embodiments, the conductive agent is chemically active. In some embodiments, the conductive agent is chemically inert.

[0028] The term "composite material" refers to a metal substrate having a coating applied to one or both sides of the metal substrate, where the metal substrate and coating may each consist of one or more layers. In the context of composite materials, the term "component" refers to the metal substrate and the coating.

[0029] The term "polymer" refers to a compound prepared by polymerizing the same or different types of monomers. The general term "polymer" encompasses the terms "homopolymer" and "copolymer."

[0030] The term "aqueous polymer" refers to a polymer that can be dispersed in an aqueous solvent such as water to form a solution or colloidal system, and the polymer in the colloidal system does not readily self-aggregate.

[0031] The term "homopolymer" refers to a polymer prepared by the polymerization of monomers of the same type.

[0032] The term "copolymer" refers to a polymer prepared by the polymerization of two or more different types of monomers.

[0033] The term "polymer binder" refers to a binder that possesses polymeric properties. The term "copolymer binder" refers to a polymer binder, and the binder is specifically a copolymer.

[0034] As used herein, the term "unsaturated" refers to a part having one or more unsaturated units.

[0035] The term "alkyl" or "alkyl group" refers to a compound of the general formula C obtained by removing a hydrogen atom from a saturated, unbranched, or branched aliphatic hydrocarbon. n H 2n+1This refers to a monovalent group having n, where n is an integer, or an integer from 1 to 20, or an integer from 1 to 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, t-butyl, pentyl, isopentyl, neopentyl, hexyl, heptyl, and octyl. Examples of long-chain alkyl groups include nonyl and decyl groups. The alkyl group may be unsubstituted or substituted with one or more suitable substituents. Furthermore, the alkyl group may be branched or unbranched. In some embodiments, the alkyl group contains at least 2, 3, 4, 5, 6, 7, or 8 carbon atoms.

[0036] The term "cycloalkyl" refers to a saturated or unsaturated cyclic non-aromatic hydrocarbon radical having a monocyclic or multiple fused rings. Examples of cycloalkyl groups include, but are not limited to, (C3-C7) cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl; (C3-C7) cycloalkenyl groups such as cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, and cycloheptenyl; and cyclic and bicyclic terpenes. Cycloalkyl groups may be unsubstituted or substituted with one or two suitable substituents. Furthermore, cycloalkyl groups may be monocyclic or polycyclic. In some embodiments, cycloalkyl groups contain at least 5, 6, 7, 8, 9, or 10 carbon atoms.

[0037] The term "alkoxy" refers to an alkyl group as defined above that is bonded to the main carbon chain through an oxygen atom. Some non-limiting examples of alkoxy groups include methoxy, ethoxy, propoxy, butoxy, and the like. The alkoxy defined above may be substituted or unsubstituted, and the substituents may be, but are not limited to, deuterium, hydroxy, amino, halo, cyano, alkoxy, alkyl, alkenyl, alkynyl, mercapto, nitro, and the like.

[0038] The term "alkenyl" refers to an unsaturated straight-chain, branched-chain, or cyclic hydrocarbon radical containing one or more carbon-carbon double bonds. Examples of alkenyl groups include, but are not limited to, ethenyl, 1-propenyl, and 2-propenyl; and may be optionally substituted at one or more carbon atoms of the radical.

[0039] The term "aryl" or "aryl group" refers to an organic radical obtained by removing a hydrogen atom from a monocyclic or polycyclic aromatic hydrocarbon. Non-limiting examples of aryl groups include phenyl group, naphthyl group, benzyl group, tolanyl, sexiphenyl, phenanthrenyl, anthracenyl, coronenyl, and tolanylphenyl. The aryl group may be unsubstituted or substituted with one or more suitable substituents. Further, the aryl group may be monocyclic or polycyclic. In some embodiments, the aryl group contains at least 6, 7, 8, 9, or 10 carbon atoms.

[0040] The term "aliphatic" refers to C1-C 30 alkyl group, C2-C 30 alkenyl group, C2-C 30 alkynyl group, C1-C 30 alkylene group, C2-C 30 alkenylene group, or C2-C 30 alkynylene group. In some embodiments, the alkyl group contains at least 2, 3, 4, 5, 6, 7, or 8 carbon atoms.

[0041] The term "aromatic" refers to a group containing an aromatic hydrocarbon ring, which may optionally include a heteroatom or substituent. Examples of such groups include, but are not limited to, phenyl, tolyl, biphenyl, o-terphenyl, m-terphenyl, p-terphenyl, naphthyl, anthryl, phenanthryl, pyrenyl, triphenylenyl, and their derivatives.

[0042] The term "substitution," used to describe a compound or chemical site, means that at least one hydrogen atom of the compound or chemical site is replaced by a second chemical site. Examples of substituents include halogens; alkyls; heteroalkyls; alkenyls; alkynyls; aryls, heteroaryls, hydroxyls; alkoxyls; aminos; nitros; thiols; thioethers; imines; cyanos; amides; phosphonates; phosphinatos; carboxyls; thiocarbonyls; sulfonyls; sulfonamides; acyls; formyls; acyloxys; alkoxycarbonyls; oxo; haloalkyls (e.g., trifluoromethyl); carbocyclic cycloalkyls that can be monocyclic or condensed or uncondensed polycyclic (e.g., cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl) or heterocycloalkyls that can be monocyclic or condensed or uncondensed polycyclic (e.g., pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, or thiadinyl); carbocyclic or heterocyclic, monocyclic or condensed or uncondensed polycyclic aryls (e.g., phenyl, naphthyl, pyrrolyl, dinopropyl, hydroxyl Ryl, furanyl, thiophenyl, imidazolyl, oxazolyl, isoxazolyl, thiazolyl, triazolyl, tetrazolyl, pyrazolyl, pyridinyl, quinolinyl, isoquinolinyl, acridinyl, pyrazinyl, pyridadinyl, pyrimidinyl, benzimidazolyl, benzothiophenyl or benzofuranyl); amino (primary, secondary or tertiary); o-lower alkyl; o-aryl, aryl; aryl-lower alkyl; -CO2CH3; -CONH2; -O Examples include, but are not limited to, CH2CONH2;-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 further, such portions may be optionally substituted by fused ring structures or crosslinks, such as -OCH2O-. These substituents may optionally be further substituted with substituents selected from such groups. All chemical groups disclosed herein may be substituted unless otherwise specified.

[0043] The term "halogen" or "halo" refers to F, Cl, Br, or I.

[0044] The term "monomer unit" refers to the constituent unit that a single monomer gives to the structure of a polymer.

[0045] The term "structural unit" refers to all monomer units given by the same monomer species within a polymer.

[0046] The term "acid-base" refers to the acidic 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.

[0047] The term "planetary mixer" refers to a device that can be used to mix or stir different materials to produce a homogeneous mixture, and consists of blades that perform planetary motion within a container. In some embodiments, a planetary mixer includes at least one planetary blade and at least one high-speed dispersion blade. The planetary blade and high-speed dispersion blade rotate on their respective axes and also rotate continuously around the container. The rotational speed can be expressed in revolutions per minute (rpm), and refers to the number of rotations the rotating body completes in one minute.

[0048] The term "ultrasonicator" refers to a device capable of agitating particles in a sample by applying ultrasonic energy. Any ultrasonicator capable of dispersing the slurry disclosed herein may be used herein. Some non-limiting examples of ultrasonicators include ultrasonic baths, probe-type ultrasonicators, and ultrasonic flow cells.

[0049] The term "ultrasonic bath" refers to a device in which ultrasonic energy is transmitted to a liquid sample through the walls of the ultrasonic bath container.

[0050] The term "probe-type ultrasonic generator" refers to an ultrasonic probe that is immersed in a medium for direct ultrasonic treatment. The term "direct ultrasonic treatment" means that ultrasound is directly coupled to the treatment solution.

[0051] The term "ultrasonic flow cell" or "ultrasonic reactor chamber" refers to an instrument capable of performing ultrasonic treatment in flow-through mode. In some embodiments, ultrasonic flow cells are single-pass, multi-pass, or recirculation configurations.

[0052] The term "application" refers to the act of laying or spreading a substance on a surface.

[0053] The term "current collector" refers to any conductive layer that is in contact with the electrode layer and capable of conducting the current flowing to the electrodes during the 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 having a conductive coating layer, such as a carbon black-based coating layer. The conductive metal layer or substrate may be in the form of a foil or porous body having a three-dimensional network structure. In some embodiments, the three-dimensional porous current collector is coated with a conformal carbon layer.

[0054] The term "electrode layer" refers to a coating that comes into contact with the current collector and contains an electrochemically active material. In some embodiments, the electrode layer is created by applying a coating to the current collector. In some embodiments, the electrode layer is located on one or both sides of the current collector. In other embodiments, a three-dimensional porous current collector is conformally coated with an electrode layer. Thus, the electrode is a composite material, the current collector is a metal substrate, and the electrode layer is a coating.

[0055] The term "room temperature" refers to an indoor temperature of approximately 18°C ​​to approximately 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 approximately 20°C ± 1°C or ± 2°C or ± 3°C. In other embodiments, room temperature refers to a temperature of approximately 22°C or approximately 25°C.

[0056] The term "solids content" refers to the amount of non-volatile material remaining after evaporation.

[0057] 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 together. It is an indicator of the bonding strength between such two materials and is usually expressed in N / cm.

[0058] The term "adhesion strength" refers to the amount of force required to separate a current collector and a polymer binder coating that are bonded together. It is an indicator of the adhesive strength between such two materials and is usually expressed in N / cm.

[0059] The term "C-rate" refers to the charging or discharging rate of a cell or battery, expressed in Ah or mAh as its total energy storage capacity. For example, a rate of 1C means that all stored energy is used in one hour; 0.1C means that 10% of the energy is used in one hour, or all the energy is used in 10 hours; and 5C means that all the energy is used in 12 minutes.

[0060] The term "ampere-hour (Ah)" refers to a unit used to specify the storage capacity of a battery. For example, a 1Ah battery can supply a current of 1 ampere for 1 hour, or a current of 0.5A for 2 hours. Therefore, 1 ampere-hour (Ah) is equivalent to 3,600 coulombs of charge. Similarly, the term "milliampere-hour (mAh)" also refers to a unit of battery storage capacity and is 1 / 1,000 of an ampere-hour.

[0061] 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.

[0062] The term "capacity" refers to the total amount of charge that an electrochemical cell, such as a battery, can hold, and is a characteristic of that electrochemical cell. Capacity is generally expressed in units of ampere-hours. The term "specific capacity" refers to the capacity output per unit weight of an electrochemical cell, such as a battery, and is usually expressed in units of Ah / kg or mAh / g.

[0063] In the following description, all figures disclosed herein are approximate, regardless of whether the words “about” or “approximately” are used in relation to them. These figures may vary by 1 percent, 2 percent, 5 percent, or in some cases 10 to 20 percent. Lower limit R L , and the upper limit R U Whenever a numerical range having R is disclosed, all numerical values ​​that fall within that range are specifically disclosed. In particular, numerical values ​​within the following range are specifically disclosed: R = R L +k * (R U -R L ), where k is a variable in the range of 0 percent to 100 percent. Furthermore, any numerical range defined by the two R numbers defined above will also be specifically disclosed.

[0064] In this specification, all singular terms include plural terms, and vice versa. As used herein, “composite material” refers to a metal substrate having a coating applied to one or both sides of the metal substrate, wherein the metal substrate and the coating may each consist of one or more layers, and the coating contains a polymer binder. In some embodiments, the polymer binder is a copolymer, i.e., a copolymer binder. Figure 1 is a simplified diagram of a composite material represented by 100. The composite material 100 includes a metal substrate 101 having a coating 102 applied to one side of the metal substrate 101. Applying a coating to a metal substrate, i.e., forming a composite material, is one of the most commonly used techniques for causing changes in the surface properties of a metal substrate to meet the performance requirements of various applications. Coatings have frequently been used for a variety of purposes, including protection (e.g., chemical resistance, corrosion, scratch, and abrasion resistance), adhesion, improved wettability, or biocompatibility.

[0065] Adhesion between the coating and the metal substrate within the composite material is achieved through the interaction between the polymer binder contained in the coating and the surface of the metal substrate to which the coating is applied. Copolymer binders that are compatible with aqueous solvents, most commonly water, can strongly adhere the coating to the metal substrate. Therefore, it is preferable to incorporate such copolymer binders in the present invention. Furthermore, since these copolymer binders can achieve good dispersibility and stability in water, aqueous coatings containing these copolymer binders will have good processability in formation, storage, and use.

[0066] 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.

[0067] Metal substrates are exposed to the atmosphere quite frequently for a period of time before a coating is applied to their surface. The atmosphere mainly consists of oxygen, water, and some organic and inorganic substances. When metal substrates are exposed to naturally occurring oxygen in the atmosphere, the formation of metal oxides on the surface of the metal substrate is unavoidable. For example, metallic aluminum reacts very readily with oxygen in the atmosphere and begins to form aluminum oxide on the exposed aluminum surface. This aluminum oxide prevents further oxidation of the aluminum contained within, and as a result, the aluminum has good corrosion resistance. When metal oxides on the surface of a metal substrate come into contact with moisture in the atmosphere, hydroxylation of the metal oxide occurs, and the surface of the metal oxide becomes rich in hydroxyl (-OH) groups.

[0068] A hydroxyl group on a metal substrate surface consists of a hydrogen atom covalently bonded to a more electronegative oxygen atom, and an electronegative oxygen atom with a lone pair of electrons in its outermost electron shell. Within a hydroxyl group, the hydrogen atom can form hydrogen bonds with other molecules containing highly electronegative atoms such as oxygen, nitrogen, or fluorine, and the oxygen atom can similarly accept hydrogen bonds from hydrogen atoms of other molecules bonded to highly electronegative atoms such as oxygen, nitrogen, or fluorine.

[0069] On the other hand, the metal portion of the substrate is, for example, a partially positively charged metal species (M) in the metal oxide formed on the surface of the metal substrate. δ+ It still exists on the surface of the metal substrate in the form of ).

[0070] Figure 2 shows a schematic diagram of the proposed coating-metal substrate interface structure of the composite material represented by 200. On the surface of the metal substrate 201 are hydroxyl (-OH) groups of metal oxides and partially positively charged metal species (M σ+ ), and oxygen (O) atoms are present. The copolymer binder contained within and / or on the surface of coating 202 contains structural units derived from carboxylic acid group-containing monomers. In this case, the structural units derived from carboxylic acid group-containing monomers contain carboxylic acid bases, where the carboxylic acid base is a salt of the carboxylic acid group.

[0071] Oxygen (O) and hydrogen (H) atoms present in the copolymer binder readily interact with the O and / or H atoms of hydroxyl groups on the surface of the metal substrate, as well as with the O atoms in the metal oxide, through hydrogen bonding. Furthermore, anions of carboxylic acid bases contained within the copolymer binder, in this case COO, also readily interact. - , and the M on the surface of the metal substrate δ+ Ion-dipole interactions act between the species. 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 surface of the metal substrate.

[0072] The copolymer binders disclosed herein are formulated to provide extremely strong coating-metal substrate adhesion for a variety of applications. However, this strong adhesion presents further challenges in subsequent recycling processes when products containing the composite material reach the end of their usefulness or lifespan, or when defective products occur during production.

[0073] The delamination of a coating from a metal substrate in a composite material is achieved by disrupting and / or rupturing the bonds between the copolymer binder contained in the coating and the surface of the metal substrate. Copolymers of different compositions exhibiting various specific properties will require different approaches to separating the coating from the metal substrate. Therefore, the method of the present invention has been specifically developed to delaminate composite materials by disrupting and / or rupturing the bonds between the aqueous copolymer binder disclosed herein and the surface of the metal substrate.

[0074] The present invention provides a method for peeling a composite material by immersing it in a peeling solution, wherein the composite material comprises a metal substrate and a coating applied to one or both sides of the metal substrate, and the coating comprises a copolymer binder.

[0075] In some embodiments, delamination of the composite material occurs along the coating-metal substrate interface.

[0076] In some embodiments, the stripping solution comprises a stripping agent and an aqueous solvent. In some embodiments, the stripping agent is a water-soluble strong base. In some embodiments, the aqueous solvent consists solely of water.

[0077] In the stripping solution, the strong base may be an alkali or alkaline earth metal oxide, an alkali or alkaline earth metal hydroxide, or a combination thereof. In the case of a hydroxide, the strong base dissociates in the aqueous solvent, releasing its constituent ions. In the case of an oxide, the oxide reacts with water instead, forming ions again.

[0078] These ions can enter the interface between the copolymer binder and the metal substrate surface. The ions disrupt hydrogen bonds and ion-dipole interactions between the copolymer binder and the metal substrate. The aqueous solvent (e.g., water) present in the stripping solution also disrupts the ion-dipole interactions between the copolymer binder and the metal substrate surface in the coating. These aqueous solvent molecules further act to solvate the copolymer, forming a solvation shell (a hydration shell in the case of water), significantly reducing the strength of the electrostatic interaction between the copolymer binder and the metal substrate in the coating.

[0079] In some embodiments, some functional groups within a polymer that can dissociate in water, such as carboxylic acid groups, are not completely dissociated in water. A strong base acts to neutralize the remaining undissociated functional groups, and if carboxylic acid functional groups are present, the corresponding anions, such as carboxylate anions, will be formed. The water attraction to such anions, e.g., carboxylate, is stronger than the water attraction to the undissociated functional groups. As these dissociable functional groups are ionized, the solvation effect of the ionized functional groups in water increases, and therefore the interaction between the polymer and the metal substrate is more effectively reduced. This, in turn, leads to coating delamination.

[0080] Accordingly, the method disclosed herein is directed toward achieving the delamination of composite materials by disrupting and / or rupturing hydrogen and / or ion-dipole interactions between the coating and the metal substrate surface via the use of a stripping solution, where the coating comprises a copolymer binder. This method is simple and does not require complex separation steps. The proposed method ensures complete delamination of the composite material at the coating-metal substrate interface and does not contaminate the metal substrate, thus enabling excellent material recovery and allowing the delamination of composite materials to be achieved with high efficiency and speed.

[0081] Non-ionized copolymer functional groups do not interact with the metal substrate surface via ion-dipole interactions. When an aqueous solvent is used alone as a stripping agent, the solvation of these non-ionized copolymer functional groups by the aqueous solvent is significantly reduced; the interaction between these copolymer functional groups in the coating and the metal substrate surface, mainly hydrogen bonds, is often not broken and does not decrease to a degree that would allow for complete stripping of the composite material, thus potentially resulting in insufficient complete removal of the coating from the metal substrate.

[0082] Therefore, in order to achieve excellent peeling performance of composite materials, both a peeling agent and an aqueous solvent are used in combination as the peeling solution. In some embodiments, the peeling solution contains both a peeling agent and an aqueous solvent.

[0083] In some embodiments, the stripping agent is a strong base. In some embodiments, the stripping agent is an alkali or alkaline earth metal hydroxide. In some embodiments, the stripping agent is an alkali or alkaline earth metal oxide. In some embodiments, the stripping agent is lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, lithium oxide, sodium oxide, potassium oxide, rubidium oxide, cesium oxide, calcium oxide, strontium oxide, barium oxide, or a combination thereof.

[0084] In some embodiments, the aqueous solvent is a solution containing water as the main component, and in addition to water, a volatile solvent such as an alcohol, a lower aliphatic ketone, or a lower alkyl acetate as a trace component. In some embodiments, the proportion of water in the aqueous solvent is about 51% to about 100% by weight, about 51% to about 95% by weight, about 51% to about 90% by weight, about 51% to about 85% by weight, about 51% to about 80% by weight, about 51% to about 75% by weight, about 51% to about 70% by weight, about 55% to about 100% by weight, about 55% to about 95% by weight, about 55% to about 90% by weight, about 55% to about 85% by weight, about 55% to about 80% by weight, about 60% to about 100% by weight, about 60% by weight The weights are approximately 95% to 60% to 90% by weight, approximately 85% to 60% by weight, approximately 80% to 60% by weight, approximately 100% to 65% by weight, approximately 95% to 65% by weight, approximately 85% to 65% by weight, approximately 100% to 70% by weight, approximately 95% to 70% by weight, approximately 90% to 70% by weight, approximately 85% to 75% by weight, approximately 95% to 70% by weight, approximately 90% to 70% by weight, approximately 85% to 75% by weight, approximately 95% to 75% by weight, or approximately 80% to 100% by weight.

[0085] In some embodiments, the proportion of water in the aqueous solvent is greater than 50% by weight, greater than 55% by weight, greater than 60% by weight, greater than 65% by weight, greater than 70% by weight, greater than 75% by weight, greater than 80% by weight, greater than 85% by weight, greater than 90% by weight, or greater than 95% by weight. In some embodiments, the proportion of water in the aqueous solvent is less than 55% by weight, less than 60% by weight, less than 65% by weight, less than 70% by weight, less than 75% by weight, less than 80% by weight, less than 85% by weight, less than 90% by weight, or less than 95% by weight. In some embodiments, the aqueous solvent consists only of water, i.e., the proportion of water in the aqueous solvent is 100% by weight.

[0086] Some non-limiting examples of water include tap water, bottled water, purified water, pure water, distilled water, DI water, D2O, and combinations thereof. In some embodiments, the aqueous solvent is deionized water. At the coating-metal substrate surface interface, water may be applied as part of the stripping solution to form a solvation shell around the copolymer binder of the coating and the metal substrate surface. This helps to disrupt the interaction between the copolymer binder in the coating and the metal substrate surface, resulting in complete delamination of the composite material.

[0087] Any water-miscible or volatile solvent can be used as a trace component (i.e., a solvent other than water) of the aqueous solvent. Some non-limiting examples of water-miscible or volatile solvents include alcohols, lower aliphatic ketones, lower alkyl acetates, and combinations thereof. The addition of alcohols can improve the solubility of the release agent and lower the freezing point of water. Some non-limiting examples of alcohols include C1-C4 alcohols such as methanol, ethanol, isopropanol, n-propanol, tert-butanol, n-butanol, and combinations thereof. Some non-limiting examples of lower aliphatic ketones include acetone, dimethyl ketone, methyl ethyl ketone (MEK), and combinations thereof. Some non-limiting examples of lower alkyl acetates include ethyl acetate (EA), isopropyl acetate, propyl acetate, butyl acetate (BA), and combinations thereof. In some embodiments, the aqueous solvent does not contain alcohols, lower aliphatic ketones, lower alkyl acetates, or combinations thereof.

[0088] Surfactants have been used as additives to stripping solutions to improve stripping speed. However, adding surfactants to stripping solutions introduces impurities into the resulting solution, reducing product purity, and requires time and money to develop separation equipment to remove the surfactants. Furthermore, surfactants are harmful to the environment when released, and some may even pose further health risks. Therefore, in some embodiments, surfactants are not added to the stripping solution. In some embodiments, the stripping solution does not contain cationic surfactants, anionic surfactants, nonionic surfactants, or amphoteric surfactants.

[0089] In some embodiments, fatty acid salts; alkyl sulfates; polyoxyalkylene alkyl ether acetates; alkylbenzene sulfonates; polyoxyalkylene alkyl ether sulfates; higher fatty acid amide sulfonates; N-acyl sarcosine salts; alkyl phosphates; polyoxyalkylene alkyl ether phosphate salts; long-chain sulfosuccinates; long-chain N-acyl glutamates; polymers and copolymers comprising acrylic acids, anhydrides, esters, vinyl monomers and / or olefins and their alkali metal, alkaline earth metal and / or ammonium salt derivatives; salts of polycarboxylic acids; formalin-shrunk naphthalene sulfonic acid Compounds; alkylnaphthalene sulfonic acid; naphthalene sulfonic acid; alkylnaphthalene sulfonate; formalin condensates of acids such as alkali metal salts, alkaline earth metal salts, ammonium salts or amine salts thereof and naphthalene sulfonate; melamine sulfonic acid; alkylmelamine sulfonic acid; formalin condensate of melamine sulfonic acid; formalin condensate of alkylmelamine sulfonic acid; alkali metal salts, alkaline earth metal salts, ammonium salts and amine salts of melamine sulfonate; lignin sulfonic acid; and anionic surfactants including alkali metal salts, alkaline earth metal salts, ammonium salts and amine salts of lignin sulfonate are not added to the stripping solution.

[0090] In some embodiments, cationic surfactants, including alkyltrimethylammonium salts such as stearyltrimethylammonium chloride, lauryltrimethylammonium 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.

[0091] In some embodiments, nonionic surfactants, including polyoxyalkylene oxide-added alkyl ethers; polyoxyalkylene styrene-phenyl ethers; polyhydric alcohols; monohydric fatty acid ester compounds; polyoxyalkylene alkylphenyl ethers; polyoxyalkylene fatty acid ethers; polyoxyalkylene sorbitan fatty acid esters; glycerin fatty acid esters; polyoxyalkylene castor oil; polyoxyalkylene hydrogenated castor oil; polyoxyalkylene sorbitol fatty acid esters; polyglycerin fatty acid esters; alkylglycerin ethers; polyoxyalkylene cholesteryl ethers; alkyl polyglucosides; sucrose fatty acid esters; polyoxyalkylene alkylamines; polyoxyethylene-polyoxypropylene block polymers; sorbitan fatty acid esters; and fatty acid alkanolamides, are not added to the stripping solution.

[0092] In some embodiments, amphoteric surfactants including 2-undecyl-N,N-(hydroxyethylcarboxymethyl)-2-imidazoline sodium salt, 2-cocoyl-2-imidazolinium hydroxide-1-carboxyethyloxy disodium salt; imidazoline-based amphoteric surfactants; 2-heptadecyl-N-carboxymethyl-N-hydroxyethylimidazolium betaine, lauryldimethylaminoacetic acid betaine, alkyl betaine, amide betaine, sulfobetaine and other betaine-based surfactants; N-laurylglycine, N-lauryl β-alanine, N-stearyl β-alanine, lauryldimethylaminooxide, oleyldimethylaminooxide, sodium lauroyl glutamate, lauryldimethylaminoacetic acid betaine; stearyldimethylaminoacetic acid betaine, cocamidopropyl hydroxysultaine, and 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine are not added to the stripping solution.

[0093] In some embodiments, the composite material includes a metal substrate and a coating applied to one or both sides of the metal substrate.

[0094] In some embodiments, the coating includes a polymer binder. The purpose of the polymer binder in the coating is to provide adhesion between the coating and the metal substrate within the composite material. In some embodiments, the polymer binder includes an aqueous copolymer.

[0095] In some embodiments, the copolymer comprises a structural unit (a), which is obtained from monomers selected from the group consisting of carboxylic acid group-containing monomers, carboxylic acid base-containing monomers, sulfonic acid group-containing monomers, sulfonic acid base-containing monomers, phosphonic acid group-containing monomers, phosphonic acid base-containing monomers, and combinations thereof. In some embodiments, the acid-base is a salt of an acid group. In some embodiments, the acid-base-containing monomer contains an alkali metal cation. Examples of alkali metals that form alkali metal cations include lithium, sodium, and potassium. In some embodiments, the acid-base-containing monomer contains an ammonium cation. In some embodiments, the structural unit (a) may be obtained from a combination of a base-containing monomer and an acid group-containing monomer.

[0096] In some embodiments, the carboxylic acid group-containing monomer is acrylic acid, methacrylic acid, crotonic acid, 2-butylcrotonic acid, cinnamic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, tetraconic acid, or a combination thereof. In certain embodiments, the carboxylic acid group-containing monomers are 2-ethylacrylic acid, isocrotonic acid, cis-2-pentenoic acid, trans-2-pentenoic acid, angelic acid, tigric acid, 3,3-dimethylacrylic acid, 3-propylacrylic acid, trans-2-methyl-3-ethylacrylic acid, cis-2-methyl-3-ethylacrylic acid, 3-isopropylacrylic acid, 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 Acids, 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 combinations thereof.In some embodiments, the carboxylic acid group-containing monomer is methyl maleic acid, dimethyl maleic acid, phenyl maleic acid, bromomaleic acid, chloromaleic acid, dichloromaleic acid, fluoromaleic acid, difluoromaleic acid, nonyl hydrogen maleate, decyl hydrogen maleate, dodecyl hydrogen maleate, octadecyl hydrogen maleate, fluoroalkyl hydrogen maleate, or a combination thereof. In some embodiments, the carboxylic acid group-containing monomer is maleic anhydride, methyl maleic anhydride, dimethyl maleic anhydride, acrylic anhydride, methacrylic anhydride, methacrolein, methacryloyl chloride, methacryloyl fluoride, methacryloyl bromide, or a combination thereof.

[0097] In some embodiments, the carboxylic acid base-containing monomer is an acrylate, methacrylate, crotonate, 2-butylcrotonate, cinnamate, maleate, maleic anhydride, fumarate, itaconate, itaconate anhydride, tetraconate, or a combination thereof. In certain embodiments, carboxylic acid base-containing monomers include 2-ethyl acrylate, isocrotonate, cis-2-pentenoate, trans-2-pentenoate, angelicaate, tigrine, 3,3-dimethyl acrylate, 3-propyl acrylate, trans-2-methyl-3-ethyl acrylate, cis-2-methyl-3-ethyl acrylate, 3-isopropyl acrylate, trans-3-methyl-3-ethyl acrylate, cis-3-methyl-3-ethyl acrylate, 2-isopropyl acrylate, trimethyl acrylate, 2-methyl-3,3-diethyl acrylate, 3-butyl acrylate, 2-butyl acrylate, 2-pentyl acrylate, 2-methyl-2-hexenoate, trans-3-methyl-2-hexenoate, 3-methyl-3-propyl acrylate, and 2-ethyl-3-propyl acrylate. These include acrylic acid salts, 2,3-diethyl acrylate, 3,3-diethyl acrylate, 3-methyl-3-hexyl acrylate, 3-methyl-3-tert-butyl acrylate, 2-methyl-3-pentyl acrylate, 3-methyl-3-pentyl acrylate, 4-methyl-2-hexenoate, 4-ethyl-2-hexenoate, 3-methyl-2-ethyl-2-hexenoate, 3-tert-butyl acrylate, 2,3-dimethyl-3-ethyl acrylate, 3,3-dimethyl-2-ethyl acrylate, 3-methyl-3-isopropyl acrylate, 2-methyl-3-isopropyl acrylate, trans-2-octenate, cis-2-octenate, trans-2-decenoate, α-acetoxyacrylate, β-trans-aryloxyacrylate, α-chloro-β-E-methoxyacrylate, or combinations thereof.In some embodiments, the carboxylic acid base-containing monomer is methyl maleate, dimethyl maleate, phenyl maleate, bromo maleate, chloro maleate, dichloro maleate, fluoro maleate, difluoro maleate, or a combination thereof.

[0098] In some embodiments, the sulfonic acid group-containing monomer is vinyl sulfonic acid, methyl vinyl sulfonic acid, allyl vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonic acid, 2-sulfoethyl methacrylic acid, 2-methylpropa-2-ene-1-sulfonic acid, 2-acrylamido-2-methyl-1-propanesulfonic acid, 3-allyloxy-2-hydroxy-1-propanesulfonic acid, allyl hydrogen sulfate, vinyl hydrogen sulfate, or a combination thereof.

[0099] In some embodiments, the sulfonic acid base-containing monomer is vinyl sulfonate, methyl vinyl sulfonate, allyl vinyl sulfonate, allyl sulfonate, methallyl sulfonate, styrene sulfonate, 2-sulfoethyl methacrylate, 2-methylpropa-2-ene-1-sulfonate, 2-acrylamido-2-methyl-1-propane sulfonate, 3-allyloxy-2-hydroxy-1-propane sulfonate, allyl sulfate salt, vinyl sulfate salt, or a combination thereof.

[0100] In some embodiments, the phosphonic acid group-containing monomer is vinylphosphonic acid, allylphosphonic acid, vinylbenzylphosphonic acid, acrylamidoalkylphosphonic acid, methacrylamidoalkylphosphonic acid, acrylamidoalkyldiphosphonic acid, acryloylphosphonic 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.

[0101] In some embodiments, the phosphonic acid base-containing monomer is a salt of vinylphosphonic acid, a salt of allylphosphonic acid, a salt of vinylbenzylphosphonic acid, a salt of acrylamidoalkylphosphonic acid, a salt of methacrylamidoalkylphosphonic acid, a salt of acrylamidoalkyldiphosphonic acid, a salt of acryloylphosphonic acid, a salt of 2-methacryloyloxyethylphosphonic acid, a salt of bis(2-methacryloyloxyethyl)phosphonic acid, a salt of ethylene 2-methacryloyloxyethylphosphonic acid, a salt of ethyl-methacryloyloxyethylphosphonic acid, an allyl phosphate salt, a vinyl phosphate salt, or a combination thereof.

[0102] In some embodiments, the proportion of structural units (a) in the copolymer is approximately 30 mol% to approximately 80 mol%, approximately 35 mol% to approximately 80 mol%, approximately 40 mol% to approximately 80 mol%, approximately 45 mol% to approximately 80 mol%, approximately 50 mol% to approximately 80 mol%, approximately 55 mol% to approximately 80 mol%, approximately 60 mol% to approximately 80 mol%, approximately 65 mol% to approximately 80 mol%, approximately 30 mol% to approximately 75 mol%, approximately 30 mol% to approximately 70 mol%, and approximately 35 mol% to approximately 70 mol% based on the total number of moles of monomer units in the copolymerizable binder. The concentrations are approximately 40 mol% to 70 mol%, 45 mol% to 70 mol%, 50 mol% to 70 mol%, 55 mol% to 70 mol%, 60 mol% to 70 mol%, 35 mol% to 65 mol%, 40 mol% to 65 mol%, 45 mol% to 65 mol%, 50 mol% to 65 mol%, 55 mol% to 65 mol%, 40 mol% to 60 mol%, 45 mol% to 60 mol%, 50 mol% to 60 mol%, 40 mol% to 55 mol%, or 45 mol% to 55 mol%.

[0103] In some embodiments, the proportion of structural units (a) in the copolymer is less than 80 mol%, less than 77.5 mol%, less than 75 mol%, less than 72.5 mol%, less than 70 mol%, less than 67.5 mol%, less than 65 mol%, less than 62.5 mol%, less than 60 mol%, 57.5 mol%, less than 55 mol%, less than 52.5 mol%, less than 50 mol%, less than 47.5 mol%, less than 45 mol%, less than 42.5 mol%, less than 40 mol%, less than 37.5 mol%, or less than 35 mol%, based on the total number of moles of monomer units in the copolymer binder. In some embodiments, the proportion of structural units (a) in the copolymer is greater than 30 mol%, greater than 32.5 mol%, greater than 35 mol%, greater than 37.5 mol%, greater than 40 mol%, greater than 42.5 mol%, greater than 45 mol%, greater than 47.5 mol%, greater than 50 mol%, greater than 52.5 mol%, greater than 55 mol%, greater than 57.5 mol%, greater than 60 mol%, greater than 62.5 mol%, greater than 65 mol%, greater than 67.5 mol%, greater than 70 mol%, greater than 72.5 mol%, or greater than 75 mol%, based on the total number of moles of monomer units in the copolymer binder.

[0104] In some embodiments, the copolymer further comprises structural units (b) obtained from monomers selected from the group consisting of amide group-containing monomers, hydroxyl group-containing monomers, and combinations thereof.

[0105] In some embodiments, the amide group-containing monomers are acrylamide, methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, Nn-propylmethacrylamide, N-isopropylmethacrylamide, isopropylacrylamide, Nn-butylmethacrylamide, N-isobutylmethacrylamide, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N,N-diethylacrylamide, N,N-diethylmethacrylamide, N-methylolmethacrylamide, N-(methoxymethyl)methacrylamide, N-(ethoxymethyl)methacrylamide, N-(propoxymethyl)methacrylamide, and N-(butoxymethyl)methacrylamide. 、NThese include N-dimethylaminopropyl methacrylamide, N,N-dimethylaminoethyl methacrylamide, N,N-dimethylol methacrylamide, diacetone methacrylamide, diacetone acrylamide, methacryloyl morpholine, N-hydroxyl methacrylamide, N-methoxymethyl acrylamide, N-methoxymethyl methacrylamide, N,N'-methylene-bis-acrylamide (MBA), N-hydroxymethyl acrylamide, or combinations thereof.

[0106] In some embodiments, the hydroxyl group-containing monomer is a C1-C1 monomer having a hydroxyl group. 20 Alkyl or C5~C 20 This is a cycloalkyl group-containing methacrylate. In some embodiments, the hydroxyl group-containing monomer 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.

[0107] In some embodiments, the proportion of structural units (b) in the copolymer is based on the total number of moles of monomer units in the copolymer binder, and ranges from about 5 mol% to about 35 mol%, about 7.5 mol% to about 35 mol%, about 10 mol% to about 35 mol%, about 12.5 mol% to about 35 mol%, about 15 mol% to about 35 mol%, about 17.5 mol% to about 35 mol%, about 20 mol% to about 35 mol%, about 22.5 mol% to about 35 mol%, and about 25 mol% to about 3 These ranges from 5 mol%, approximately 27.5 mol% to 35 mol%, approximately 30 mol% to 35 mol%, approximately 10 mol% to 30 mol%, approximately 12.5 mol% to 30 mol%, approximately 15 mol% to 30 mol%, approximately 17.5 mol% to 30 mol%, approximately 20 mol% to 30 mol%, approximately 22.5 mol% to 30 mol%, approximately 25 mol% to 30 mol%, approximately 10 mol% to 25 mol%, approximately 12.5 mol% to 25 mol%, or approximately 15 mol% to 25 mol%.

[0108] In some embodiments, the proportion of structural units (b) in the copolymer is less than 35 mol%, less than 32.5 mol%, less than 30 mol%, less than 27.5 mol%, less than 25 mol%, less than 22.5 mol%, less than 20 mol%, less than 17.5 mol%, less than 15 mol%, less than 12.5 mol%, or less than 10 mol%, based on the total number of moles of monomer units in the copolymer binder. In some embodiments, the proportion of structural units (b) in the copolymer is greater than 5 mol%, greater than 7.5 mol%, greater than 10 mol%, greater than 12.5 mol%, greater than 15 mol%, greater than 17.5 mol%, greater than 20 mol%, greater than 22.5 mol%, greater than 25 mol%, greater than 27.5 mol%, or greater than 30 mol%, based on the total number of moles of monomer units in the copolymer binder.

[0109] In some embodiments, the copolymer further comprises structural units (c) obtained from monomers selected from the group consisting of nitrile group-containing monomers, ester group-containing monomers, epoxy group-containing monomers, fluorine-containing monomers, and combinations thereof.

[0110] In some embodiments, the nitrile group-containing monomers include α,β-ethylenically unsaturated nitrile monomers. In some embodiments, the nitrile group-containing monomers are acrylonitrile, α-halogenoacrylonitrile, α-alkylacrylonitrile, or a combination thereof. In some embodiments, the nitrile group-containing monomers are α-chloroacrylonitrile, α-bromoacrylonitrile, α-fluoroacrylonitrile, methacrylonitrile, α-ethylacrylonitrile, α-isopropylacrylonitrile, α-n-hexylacrylonitrile, α-methoxyacrylonitrile, 3-methoxyacrylonitrile, 3-ethoxyacrylonitrile, α-acetoxyacrylonitrile, α-phenylacrylonitrile, α-tolylacrylonitrile, α-(methoxyphenyl)acrylonitrile, α-(chlorophenyl)acrylonitrile, α-(cyanophenyl)acrylonitrile, vinylidene cyanide, or a combination thereof.

[0111] In some embodiments, the ester group-containing monomer is C1-C 20 Alkyl acrylates, C1-C 20These are alkyl (meth)acrylates, cycloalkyl acrylates, or combinations thereof. In some embodiments, the ester group-containing monomers are methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, sec-butyl acrylate, tert-butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, 3,3,5-trimethylhexyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, lauryl acrylate, n-tetradecyl acrylate, octadecyl acrylate, cyclohexyl acrylate, phenyl acrylate, methoxymethyl acrylate, methoxyethyl acrylate, ethoxymethyl acrylate, ethoxyethyl acrylate, perfluorooctyl acrylate, stearyl acrylate, or combinations thereof. In some embodiments, the ester group-containing monomer 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 monomers are 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, stearyl methacrylate, 2,2,2-trifluoroethyl methacrylate, phenyl methacrylate, benzyl methacrylate, or combinations thereof.

[0112] In some embodiments, the epoxy group-containing monomers are 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.

[0113] In some embodiments, epoxy group-containing monomers include 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-heptenoate, glycidyl 5-methyl-4-heptenoate, glycidyl sorbate, glycidyl linoleate, glycidyl oleate, glycidyl 3-butenoate, glycidyl 3-pentenoate, glycidyl-4-methyl-3-pentenoate, or combinations thereof.

[0114] In some embodiments, the fluorine-containing monomer is C1-C 20The monomer is an alkyl group-containing acrylate, methacrylate, or a combination thereof, and 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 at least one C1-C 20 The carboxylate is a carboxylate comprising an alkyl group and at least one fluorine atom; the carboxylate is selected from the group consisting of crotonate, malatate, fumarate, itaconate, or a combination thereof. In some embodiments, the fluorine-containing monomer is vinyl fluoride, trifluoroethylene, trifluorochloroethylene, fluoroalkyl vinyl ether, perfluoroalkyl vinyl ether, hexafluoropropylene, 2,3,3,3-tetrafluoropropene, vinylidene fluoride, tetrafluoroethylene, 2-fluoroacrylate, or a combination thereof.

[0115] In some embodiments, the proportion of structural units (c) in the copolymer is based on the total number of moles of monomer units in the copolymer binder, and is approximately 10 mol% to 60 mol%, approximately 10 mol% to 55 mol%, approximately 10 mol% to 50 mol%, approximately 10 mol% to 45 mol%, approximately 10 mol% to 40 mol%, approximately 10 mol% to 35 mol%, approximately 10 mol% to 30 mol%, and approximately 15 mol%. The percentages are approximately 60 mol%, approximately 15 mol% to approximately 55 mol%, approximately 15 mol% to approximately 50 mol%, approximately 15 mol% to approximately 45 mol%, approximately 15 mol% to approximately 40 mol%, approximately 15 mol% to approximately 35 mol%, approximately 15 mol% to approximately 30 mol%, approximately 20 mol% to approximately 50 mol%, approximately 20 mol% to approximately 45 mol%, approximately 20 mol% to approximately 40 mol%, approximately 20 mol% to approximately 35 mol%, or approximately 20 mol% to approximately 30 mol%.

[0116] In some embodiments, the proportion of structural units (c) in the copolymer is less than 60 mol%, less than 57.5 mol%, less than 55 mol%, less than 52.5 mol%, less than 50 mol%, less than 47.5 mol%, less than 45 mol%, less than 42.5 mol%, less than 40 mol%, less than 37.5 mol%, less than 35 mol%, less than 32.5 mol%, less than 30 mol%, less than 27.5 mol%, less than 25 mol%, less than 22.5 mol%, less than 20 mol%, less than 17.5 mol%, or less than 15 mol%, based on the total number of moles of monomer units in the copolymer binder. In some embodiments, the proportion of structural units (c) in the copolymer is greater than 10 mol%, greater than 12.5 mol%, greater than 15 mol%, greater than 17.5 mol%, greater than 20 mol%, greater than 22.5 mol%, greater than 25 mol%, greater than 27.5 mol%, greater than 30 mol%, greater than 32.5 mol%, greater than 35 mol%, greater than 37.5 mol%, greater than 40 mol%, greater than 42.5 mol%, greater than 45 mol%, greater than 47.5 mol%, greater than 50 mol%, greater than 52.5 mol%, or greater than 55 mol%.

[0117] In other embodiments, the copolymer may further comprise structural units derived from the olefin. Any hydrocarbon having at least one carbon-carbon double bond may be used as the olefin without particular limitation. In some embodiments, the olefin is C2-C 20 Aliphatic compounds, C8~C 20 Aromatic compounds or cyclic compounds containing vinyl unsaturated compounds, C4-C 40 This includes dienes and combinations thereof. In some embodiments, olefins are 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, ethylidenenorbornene, cyclopentene, cyclohexene, dicyclopentadiene, cyclooctene, or combinations thereof. In some embodiments, the copolymer does not contain structural units derived from olefins. In some embodiments, the copolymer does not contain structural units derived from styrene, ethylene, propylene, 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, ethylidenenorbornene, cyclopentene, cyclohexene, dicyclopentadiene, or cyclooctene.

[0118] The conjugated diene group-containing monomer is configured as an olefin. In some embodiments, the conjugated diene group-containing monomer is C4-C 40Dienes; aliphatic conjugated diene monomers such as 1,3-butadiene, 1,3-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,7-octadiene, 1,9-decadiene, isoprene, myrcene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene; substituted linear conjugated pentadienes, substituted side-chain conjugated hexadienes; and combinations thereof. In some embodiments, the copolymer is 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-decadien, isoprene, myrcene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene; substituted linear conjugated pentadiene; or structural units obtained from substituted side-chain conjugated hexadienes are not included.

[0119] In other embodiments, the copolymer may further contain structural units derived from aromatic vinyl group-containing monomers. In some embodiments, the aromatic vinyl group-containing monomer is styrene, α-methylstyrene, vinyltoluene, divinylbenzene, or a combination thereof. In some embodiments, the copolymer does not contain structural units derived from aromatic vinyl group-containing monomers. In some embodiments, the copolymer does not contain structural units obtained from styrene, α-methylstyrene, vinyltoluene, or divinylbenzene.

[0120] 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 consist of two or more layers, and 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.

[0121] In some embodiments, if the metal substrate includes two or more layers, the metal substrate includes 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 oxide, cellulose polymer, and combinations thereof. If the metal substrate includes a layer of insulating material, the coating is applied on the metal layer outside the substrate.

[0122] In some embodiments, the metal substrate is coated with a layer of carbonaceous material. Such a layer of carbonaceous material may be part of a coating layer. In some embodiments, the metal substrate is not coated with a layer of carbonaceous material.

[0123] If the immersion time of the composite material in the stripping solution is insufficient, the stripping agent and aqueous solvent contained in the stripping solution may not have enough time to destabilize, break, and rupture the initial bond between the coating and the metal substrate surface to the extent that complete removal of the composite material is possible. However, if the composite material is immersed in the stripping solution for a long time, the contact time between the composite material and the stripping agent (e.g., a strong base) contained in the stripping solution will be prolonged, which may cause corrosion of the metal substrate. There is no particular limit to the time required for stripping, but it is desirable that it be long enough to achieve complete stripping, and short enough not to cause corrosion of the metal substrate.

[0124] In some embodiments, the composite material will last approximately 1 second to 120 minutes, 5 seconds to 120 minutes, 10 seconds to 120 minutes, 20 seconds to 120 minutes, 30 seconds to 120 minutes, 45 seconds to 120 minutes, 60 seconds to 120 minutes, 75 seconds to 120 minutes, 90 seconds to 120 minutes, 105 seconds to 120 minutes, 120 seconds to 120 minutes, 30 seconds to 90 minutes, 30 seconds to 75 minutes, 30 seconds to 60 minutes, 30 seconds to 45 minutes, and 30 seconds to 30 minutes. The product is immersed in the stripping solution for approximately 30 seconds to 20 minutes, 30 seconds to 10 minutes, 30 seconds to 5 minutes, 60 seconds to 90 minutes, 60 seconds to 75 minutes, 60 seconds to 60 minutes, 60 seconds to 45 minutes, 60 seconds to 30 minutes, 60 seconds to 20 minutes, 60 seconds to 10 minutes, 60 seconds to 5 minutes, 120 seconds to 60 minutes, 120 seconds to 45 minutes, 120 seconds to 30 minutes, 120 seconds to 20 minutes, 120 seconds to 10 minutes, or 120 seconds to 5 minutes.

[0125] In some embodiments, the composite material is immersed in the release liquid for a time of 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 material is immersed in the release liquid for a time exceeding 1 second, exceeding 5 seconds, exceeding 10 seconds, exceeding 20 seconds, exceeding 30 seconds, exceeding 45 seconds, exceeding 60 seconds, exceeding 75 seconds, exceeding 90 seconds, exceeding 105 seconds, exceeding 120 seconds, exceeding 5 minutes, exceeding 10 minutes, exceeding 20 minutes, or exceeding 30 minutes.

[0126] The temperature of peeling is not particularly limited, but it is desirable that the temperature is not so low that it requires an extremely long time to achieve complete peeling, nor so high that it poses risks to health and safety.

[0127] In some embodiments, the composite material is immersed in the release liquid at a temperature of about 10°C to about 90°C, about 15°C to about 90°C, about 20°C to about 90°C, about 25°C to about 90°C, about 30°C to about 90°C, about 35°C to about 90°C, about 40°C to about 90°C, about 45°C to about 90°C, about 50°C to about 90°C, about 55°C to about 90°C, about 60°C to about 90°C, about 65°C to about 90°C, about 70°C to about 90°C, about 75°C to about 90°C, about 20°C to about 75°C, about 25°C to about 75°C, about 30°C to about 75°C, about 35°C to about 75°C, about 40°C to about 75°C, about 45°C to about 75°C, about 50°C to about 75°C, about 55°C to about 75°C, about 60°C to about 75°C, about 25°C to about 60°C, about 30°C to about 60°C, about 35°C to about 60°C, about 40°C to about 60°C, or about 45°C to about 60°C.

[0128] In some embodiments, the composite material is immersed in the stripping solution at a temperature of less than 90°C, less than 85°C, less than 80°C, less than 75°C, less than 70°C, less than 65°C, less than 60°C, less than 55°C, less than 50°C, less than 45°C, less than 40°C, less than 35°C, or less than 30°C. In some embodiments, the composite material is immersed in the stripping solution at a temperature greater than 10°C, greater than 15°C, greater than 20°C, greater than 25°C, greater than 30°C, greater than 35°C, greater than 40°C, greater than 45°C, greater than 50°C, greater than 55°C, greater than 60°C, greater than 65°C, or greater than 70°C.

[0129] If the amount of the stripping solution used for the immersion of a predetermined amount of the composite material is insufficient, complete stripping of the composite material cannot be performed. As a result, most of the coating may still be deposited or adhered to the surface of the metal substrate. Even if the amount of the stripping solution used is too large, there is no particular disadvantage with respect to the stripping performance, but it results in waste of raw materials and furthermore, there may be generated unnecessary contaminated or polluted aqueous solvent waste that requires additional processing steps for solvent reuse. Therefore, the ratio of the stripping solution to the composite material has no particular limitation except that it is sufficient to enable stripping of all the existing composite materials and that, for cost reasons, the use of an overly large ratio of the stripping agent to the composite material is not recommended.

[0130] In some embodiments, when the composite material is immersed in a stripping solution to achieve stripping of the composite material, the weight ratio of the composite material to the stripping solution is approximately 0.01% to 50%, approximately 0.02% to 50%, approximately 0.05% to 50%, approximately 0.1% to 50%, approximately 0.2% to 50%, approximately 0.5% to 50%, approximately 1% to 50%, approximately 2% to 50%, approximately 5% to 50%, approximately 10% to 50%, approximately 15% to 50%, approximately 20% to 50%, approximately 25% to 50%, approximately 30% to 50%, and approximately 0.01% to 50%. The percentages are approximately 25%, 0.02% to 25%, 0.05% to 25%, 0.1% to 25%, 0.2% to 25%, 0.5% to 25%, 1% to 25%, 2% to 25%, 5% to 25%, 10% to 25%, 0.1% to 15%, 0.2% to 15%, 0.5% to 15%, 1% to 15%, 2% to 15%, 5% to 15%, 0.1% to 5%, 0.2% to 5%, 0.5% to 5%, 1% to 5%, or 2% to 5%.

[0131] In some embodiments, when a composite material is immersed in a stripping solution to achieve delamination of the composite material, the weight ratio of the composite material 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 a composite material is immersed in a stripping solution to achieve delamination of the composite material, the weight ratio of the composite material 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%.

[0132] The purpose of a stripping agent is to disrupt and break the ion-dipole and hydrogen bonding interactions between the copolymer binder contained in the coating and the surface of the metal substrate. A sufficient concentration of stripping agent is required in the stripping solution to efficiently disrupt the interactions between the coating and the metal substrate, thereby causing the composite material to delaminate. Relatively low concentrations of stripping agent are appropriate to induce the disruption of the interactions between the copolymer binder in the coating and the surface of the metal substrate. Using low concentrations of stripping agent for immersion of composite materials reduces the potential for corrosion of the metal substrate and other potential metal components of the composite material, and / or mitigates side reactions that may result from the use of high concentrations of stripping agent.

[0133] In some embodiments, the concentration of the stripping agent in the stripping solution is approximately 0.05 M to 2 M, approximately 0.1 M to 2 M, approximately 0.15 M to 2 M, approximately 0.2 M to 2 M, approximately 0.25 M to 2 M, approximately 0.3 M to 2 M, approximately 0.4 M to 2 M, approximately 0.5 M to 2 M, approximately 0.05 M to 1 M, approximately 0.1 M to 1 M, approximately 0.15 M to 1 M, approximately 0.2 M to 1 M, approximately 0.25 M to 1 M, approximately 0.3 M to 1 M, approximately 0.4 M to 1 M, approximately 0.5 M to 1 M, approximately 0.05 M to 0.5 M, approximately 0.1 M to 0.5 M, approximately 0.15 M to 0.5 M, approximately 0.2 M to 0.5 M, or approximately 0.25 M to 0.5 M.

[0134] In some embodiments, the concentration of the stripping agent in the stripping solution is less than 2 M, less than 1.8 M, less than 1.6 M, less than 1.4 M, less than 1.2 M, less than 1 M, less than 0.8 M, less than 0.6 M, less than 0.5 M, less than 0.4 M, less than 0.3 M, or less than 0.25 M. In some embodiments, the concentration of the stripping agent in the stripping solution is greater than 0.05 M, greater than 0.1 M, greater than 0.15 M, greater than 0.2 M, greater than 0.25 M, greater than 0.3 M, greater than 0.4 M, greater than 0.5 M, greater than 0.6 M, greater than 0.8 M, greater than 1 M, or greater than 1.2 M.

[0135] In some embodiments, the surface density of the coating is approximately 1 mg / cm³. 2 ~about 50mg / cm 2Approximately 2.5 mg / cm 2 ~approximately 50mg / cm 2 Approximately 5 mg / cm 2 ~approximately 50mg / cm 2 Approximately 7.5 mg / cm³ 2 ~approximately 50mg / cm 2 Approximately 10 mg / cm 2 ~approximately 50mg / cm 2 Approximately 12.5 mg / cm 2 ~approximately 50mg / cm 2 Approximately 15 mg / cm 2 ~approximately 50mg / cm 2 Approximately 17.5 mg / cm³ 2 ~approximately 50mg / cm 2 Approximately 20 mg / cm 2 ~approximately 50mg / cm 2 Approximately 25 mg / cm 2 ~approximately 50mg / cm 2 Approximately 30 mg / cm 2 ~approximately 50mg / cm 2 Approximately 1 mg / cm 2 ~approximately 30mg / cm 2 Approximately 2.5 mg / cm 2 ~approximately 30mg / cm 2 Approximately 5 mg / cm 2 ~approximately 30mg / cm 2 Approximately 7.5 mg / cm³ 2 ~approximately 30mg / cm 2 Approximately 10 mg / cm 2 ~approximately 30mg / cm 2 Approximately 12.5 mg / cm 2 ~approximately 30mg / cm 2 Approximately 15 mg / cm 2 ~approximately 30mg / cm 2 Approximately 17.5 mg / cm³ 2 ~approximately 30mg / cm 2 Approximately 20 mg / cm 2 ~approximately 30mg / cm 2 Approximately 1 mg / cm 2 ~approximately 20 mg / cm 2 Approximately 2.5 mg / cm 2 ~approximately 20 mg / cm 2 Approximately 5 mg / cm 2 ~approximately 20 mg / cm 2 Approximately 7.5 mg / cm³ 2~about 20 mg / cm 2 、about 10 mg / cm 2 ~about 20 mg / cm 2 、about 12.5 mg / cm 2 ~about 20 mg / cm 2 、about 1 mg / cm 2 2 、about 2.5 mg / cm 2 ~about 15 mg / cm 2 、about 5 mg / cm 2 ~about 15 mg / cm 2 、about 7.5 mg / cm 2 ~about 15 mg / cm 2 、or about 10 mg / cm 2 ~about 15 mg / cm 2 is.

[0136] In some embodiments, the surface density of the coating is less than 50 mg / cm 2 、less than 45 mg / cm 2 、less than 35 mg / cm 2 、less than 30 mg / cm 2 、less than 25 mg / cm 2 、less than 20 mg / cm 2 、less than 17.5 mg / cm 2 、less than 15 mg / cm 2 、less than 12.5 mg / cm 2 、less than 10 mg / cm 2 、less than 7.5 mg / cm 2 、5 mg / cm 2 、less than or 2.5 mg / cm 2 is less than. In some embodiments, the surface density of the coating is greater than 1 mg / cm 2 、greater than 2.5 mg / cm 2 、greater than 5 mg / cm 2 、greater than 7.5 mg / cm 2 、greater than 10 mg / cm 2 、greater than 12.5 mg / cm 2 、greater than 15 mg / cm 2 、greater than 17.5 mg / cm 2 、greater than 20 mg / cm 2 、greater than 25 mg / cm 2 、greater than 30 mg / cm2 Exceeding 35 mg / cm³ 2 Exceeding 40 mg / cm³, or 40 mg / cm³ 2 It exceeds.

[0137] In some embodiments, the coating density is approximately 0.5 g / cm³. 3 ~Approx. 7.5g / cm 3 , about 1g / cm 3 ~Approx. 7.5g / cm 3 , about 1.5g / cm 3 ~Approx. 7.5g / cm 3 , about 2g / cm 3 ~Approx. 7.5g / cm 3 , about 2.5g / cm 3 ~Approx. 7.5g / cm 3 , about 3g / cm 3 ~Approx. 7.5g / cm 3 , about 3.5g / cm 3 ~Approx. 7.5g / cm 3 Approximately 4 g / cm³ 3 ~Approx. 7.5g / cm 3 , about 4.5g / cm 3 ~Approx. 7.5g / cm 3 , about 5g / cm 3 ~Approx. 7.5g / cm 3 , about 0.5g / cm 3 ~about 5g / cm 3 , about 1g / cm 3 ~about 5g / cm 3 , about 1.5g / cm 3 ~about 5g / cm 3 , about 2g / cm 3 ~about 5g / cm 3 , about 2.5g / cm 3 ~about 5g / cm 3 , about 3g / cm 3 ~about 5g / cm 3 , about 0.5g / cm 3 ~Approx. 2.5g / cm 3 , about 1g / cm 3 ~Approx. 2.5g / cm 3 , or approximately 1.5 g / cm³ 3 ~Approx. 2.5g / cm 3 That is the case.

[0138] In some embodiments, the coating density is 7.5 g / cm³. 3 Less than 7 g / cm³ 3 Less than 6.5 g / cm³ 3 Less than 6 g / cm³ 3 Less than 5.5 g / cm³ 3 Less than 5 g / cm³ 3 Less than 4.5 g / cm³ 3 Less than 4 g / cm³ 3 Less than 3.5 g / cm³ 3 Less than 3 g / cm³ 3 Less than 2.5 g / cm³ 3 Less than 2 g / cm³ 3 Less than 1.5 g / cm³ 3 It is less than 0.5 g / cm³. In some embodiments, the density of the coating is 0.5 g / cm³. 3 Exceeding 1 g / cm³ 3 Exceeding 1.5 g / cm³ 3 Exceeding 2g / cm³ 3 Exceeding 2.5 g / cm³ 3 Exceeding 3g / cm³ 3 Exceeding 3.5 g / cm³ 3 Exceeding 4g / cm³ 3 Exceeding 4.5 g / cm³ 3 Exceeding 5g / cm³ 3 Exceeding 5.5 g / cm³ 3 Exceeding 6g / cm³ 3 If it exceeds 6.5 g / cm³, or 6.5 g / cm³ 3 It exceeds.

[0139] In some embodiments, the composite material-striping solution mixture is agitated while the composite material is immersed in the stripping solution to achieve stripping of the composite material. In some embodiments, a planetary agitator, a stirring mixer, a blender, an ultrasonic generator, or a combination thereof is used to agitate the composite material-striping solution mixture. In other embodiments, the composite material-striping solution mixture is not agitated while the composite material is immersed in the stripping solution.

[0140] In the above embodiment, the composite material-peeling liquid moly is applied at approximately 10 rpm to approximately 3000 rpm, approximately 20 rpm to approximately 3000 rpm, approximately 50 rpm to approximately 3000 rpm, approximately 100 rpm to approximately 3000 rpm, approximately 200 rpm to approximately 3000 rpm, approximately 250 rpm to approximately 3000 rpm, approximately 300 rpm to approximately 3000 rpm, approximately 400 rpm to approximately 3000 rpm, approximately 500 rpm to approximately 3000 rpm, approximately 600 rpm to approximately 3000 rpm, approximately 750 rpm to approximately 3000 rpm, approximately 900 rpm to approximately 3000 rpm, approximately 1200 rpm to approximately 3000 rpm, approximately 1500 rpm to approximately 3000 rpm, approximately 10 rpm to approximately 1000 rpm, approximately 20 rpm to approximately 1000 rpm, and approximately 50 rpm to approximately 10 The mixture is stirred at speeds of 00 rpm, approximately 100 rpm to 1000 rpm, approximately 200 rpm to 1000 rpm, approximately 250 rpm to 1000 rpm, approximately 300 rpm to 1000 rpm, approximately 400 rpm to 1000 rpm, approximately 500 rpm to 1000 rpm, approximately 10 rpm to 750 rpm, approximately 20 rpm to 750 rpm, approximately 50 rpm to 750 rpm, approximately 100 rpm to 750 rpm, approximately 200 rpm to 750 rpm, approximately 250 rpm to 750 rpm, approximately 300 rpm to 750 rpm, approximately 10 rpm to 500 rpm, approximately 20 rpm to 500 rpm, approximately 50 rpm to 500 rpm, approximately 100 rpm to 500 rpm, or approximately 200 rpm to 500 rpm.

[0141] In some embodiments, the composite material-striping solution mixture is stirred at a speed of 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 composite material-striping solution mixture is stirred at a speed 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.

[0142] In some embodiments, the composite material-release solution mixture is used for approximately 1 second to 120 minutes, approximately 5 seconds to 120 minutes, approximately 10 seconds to 120 minutes, approximately 20 seconds to 120 minutes, approximately 30 seconds to 120 minutes, approximately 45 seconds to 120 minutes, approximately 60 seconds to 120 minutes, approximately 75 seconds to 120 minutes, approximately 900 seconds to 120 minutes, approximately 105 seconds to 120 minutes, approximately 120 seconds to 120 minutes, approximately 30 seconds to 90 minutes, approximately 30 seconds to 75 minutes, approximately 30 seconds to 60 minutes, approximately 30 seconds to 45 minutes, and approximately 30 The mixture is stirred for approximately 12 seconds to 30 minutes, 30 seconds to 20 minutes, 30 seconds to 10 minutes, 30 seconds to 5 minutes, 60 seconds to 90 minutes, 60 seconds to 75 minutes, 60 seconds to 60 minutes, 60 seconds to 45 minutes, 60 seconds to 30 minutes, 60 seconds to 20 minutes, 60 seconds to 10 minutes, 60 seconds to 5 minutes, 120 seconds to 60 minutes, 120 seconds to 45 minutes, 120 seconds to 30 minutes, 120 seconds to 20 minutes, 120 seconds to 10 minutes, or 120 seconds to 5 minutes.

[0143] In some embodiments, the composite material-strip mixture is stirred for a time of 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 material-strip mixture is stirred for a time of 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.

[0144] In some embodiments, the planetary agitator mixer includes at least one planetary blade and at least one high-speed dispersion blade. In certain embodiments, the rotational speed of the planetary blade is about 20 rpm to about 200 rpm, about 20 rpm to about 150 rpm, about 30 rpm to about 150 rpm, or about 50 rpm to about 100 rpm. In certain embodiments, the rotational speed of the dispersion blade is about 1,000 rpm to about 4,000 rpm, about 1,000 rpm to about 3,500 rpm, about 1,000 rpm to about 3,000 rpm, about 1,000 rpm to about 2,000 rpm, about 1,500 rpm to about 3,000 rpm, or about 1,500 rpm to about 2,500 rpm.

[0145] 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 power densities of approximately 10 W / L to approximately 100 W / L, approximately 20 W / L to approximately 100 W / L, approximately 30 W / L to approximately 100 W / L, approximately 40 W / L to approximately 80 W / L, approximately 40 W / L to approximately 70 W / L, approximately 40 W / L to approximately 60 W / L, approximately 40 W / L to approximately 50 W / L, approximately 50 W / L to approximately 60 W / L, approximately 20 W / L to approximately 80 W / L, approximately 20 W / L to approximately 60 W / L, or approximately 20 W / L to approximately 40 W / L. In certain embodiments, the ultrasonic generator is operated at a power density exceeding 10 W / L, 20 W / L, 30 W / L, 40 W / L, 50 W / L, 60 W / L, 70 W / L, 80 W / L, or 90 W / L.

[0146] In some embodiments, the ultrasonic generator operates with power ranging from approximately 100W to approximately 1000W, approximately 200W to approximately 1000W, approximately 300W to approximately 1000W, approximately 400W to approximately 1000W, approximately 500W to approximately 1000W, approximately 500W to approximately 900W, approximately 500W to approximately 800W, approximately 500W to approximately 700W, or approximately 500W to approximately 600W. In some embodiments, the ultrasonic generator operates with power ranging from less than 1000W, less than 900W, less than 800W, less than 700W, less than 600W, less than 500W, less than 400W, or less than 300W. In some embodiments, the ultrasonic generator operates at power exceeding 100W, 200W, 300W, 400W, 500W, 600W, 700W, or 800W.

[0147] In some embodiments, after immersing the composite material in the stripping solution, the pH of the composite material-stripping solution mixture after stripping is approximately 10 to approximately 14, approximately 10.25 to approximately 14, approximately 10.5 to approximately 14, approximately 10.75 to approximately 14, approximately 11 to approximately 14, approximately 11.25 to approximately 14, approximately 11.5 to approximately 14, approximately 11.5 to approximately 13.75, approximately 11.5 to approximately 13.5, approximately 11.5 to approximately 13.25, approximately 11.5 to approximately 13, approximately 11.5 to approximately 12.75, or approximately 11.5 to approximately 12.5.

[0148] In some embodiments, after immersion of the composite material in the stripping solution, the pH of the composite material-stripping solution mixture after stripping is less than 14, less than 13.75, less than 13.5, less than 13.25, less than 13, less than 12.75, less than 12.5, less than 12.25, less than 12, less than 11.75, or less than 11.5. In some embodiments, after immersion of the composite material in the stripping solution, the pH of the composite material-stripping solution mixture after stripping is greater than 10, greater than 10.25, greater than 10.5, greater than 10.75, greater than 11, greater than 11.25, greater than 11.5, greater than 11.75, greater than 12, greater than 12.25, or greater than 12.5.

[0149] In some embodiments, after the composite material is immersed in the stripping solution, the composite material is separated into two or more layers. In some embodiments, after the composite material is immersed in the stripping solution, the composite material is separated into a coating layer and a metal substrate layer.

[0150] In some embodiments, the post-stripping composite material-stripping solution mixture is sieved to separate the coating layer and the metal substrate layer from the stripping solution. In some embodiments, filtration, sieving, decantation, or a combination thereof may be used for sieving the post-stripping composite material-stripping solution mixture.

[0151] FIG. 3 is a flowchart of an embodiment showing the steps of a method 300 for stripping a composite material disclosed herein and subsequent further processing for the extraction of the coating and metal substrate materials. Due to the fairly low corrosion and dissolution tendency of the metal substrate in the present invention, the extracted stripping solution does not necessarily need to be purified for further reuse. The extracted stripping solution can be reused for the stripping of other composite materials. This enables the formation of a closed-loop recovery process in which materials are repeatedly recycled and reused, continuously participating in the loop configuration and helping to form a circular economy.

[0152] In some embodiments, the recovered stripped composite material may be subjected to additional separation and / or extraction processes to further extract their respective components contained therein. In some embodiments, the recovered coating layer and metal substrate layer may be subjected to additional separation and / or extraction processes to further extract the coating and metal substrate components.

[0153] The method of the present invention is particularly applicable in achieving the stripping of electrodes in a battery, the electrodes of which are composite materials, and the electrode layer and the current collector thereof are a coating and a metal substrate, respectively.

[0154] In some embodiments, the battery may be a primary or secondary battery. Some non-limiting examples of batteries include alkaline batteries, aluminum-air batteries, lithium batteries, lithium-air batteries, magnesium batteries, solid-state batteries, silver oxide batteries, zinc-air batteries, aluminum-ion batteries, lead-acid batteries, lithium-ion batteries, magnesium-ion batteries, potassium-ion batteries, sodium-ion batteries, sodium-air batteries, silicon-air batteries, zinc-ion batteries, and sodium-sulfur batteries.

[0155] Within the electrode, a binder can be used to adhere active material particles and a conductive agent to the current collector, forming a continuous electrical conduction path. The copolymer binder disclosed herein has excellent adhesion and can therefore be used. Because the adhesion is good not only between the electrode layer and the current collector but also between the electrode layer components, using such a copolymer binder can reduce the impedance and interfacial resistance between the current collector and the electrode material, thereby improving the ion transport rate and electron transport rate. Furthermore, the disclosed copolymer readily interacts with water through hydrogen bonding and ion-dipole interactions, and the copolymer binder has excellent dispersibility and stability in water, enabling good processability in the formation of the electrode layer using an aqueous slurry.

[0156] Current methods for separating the electrode layer from the current collector during battery recycling have drawbacks, such as the high temperatures required for firing and the harmful substances generated, or the dangerous and hazardous chemicals released during leaching.

[0157] Conversely, the stripping method disclosed herein allows for the effective stripping of an electrode comprising a current collector and an electrode layer coated on one or both sides of the current collector, wherein the electrode layer contains the copolymer binder disclosed herein, by simple use of a stripping solution without safety concerns or environmental impact. Furthermore, the stripping process is highly efficient.

[0158] Figure 4 shows the recovered cathode layer and current collector of Example 2 after immersion of the double-sided coated cathode in the stripping solution. The cathode contains a copolymer binder, and the stripping solution contains 0.1 M sodium hydroxide and DI water. The cathode layer was completely removed from the aluminum current collector, and no discoloration or pitting corrosion was observed on the aluminum current collector, indicating no significant corrosion of the aluminum current collector.

[0159] Figure 5 shows a recovered cathode from Comparative Example 1, where a double-sided coated cathode immersed in the stripping solution represents a cathode containing polyvinylidene fluoride (PVDF) as a polymer binder. The stripping solution used here contains 0.1 M sodium hydroxide and DI water. It is shown that stripping the cathode layer from the aluminum current collector is unsuccessful because the cathode layer adheres strongly to the aluminum current collector even after immersion in the stripping solution. This indicates that the use of the stripping agents disclosed in this invention to achieve electrode stripping is not applicable to electrodes containing non-aqueous polymer binders such as PVDF.

[0160] A current collector acts to collect electrons generated by the electrochemical reaction of the cathode active material, or to supply electrons necessary for the electrochemical reaction. In some embodiments, the current collector may be in the form of a foil, sheet, or film. In some embodiments, the current collector is a metal. In some embodiments, the current collector is selected from the group consisting of stainless steel, titanium, nickel, aluminum, copper, platinum, gold, silver, chromium, zirconium, tungsten, molybdenum, tin, vanadium, zinc, cadmium, iron, cobalt, lead, and 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, the material of each layer may be the same, different, or partially different.

[0161] In some embodiments, if the current collector comprises two or more layers, the current collector includes 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 oxide, cellulose polymer, and combinations thereof. If the current collector comprises a layer of insulating material, the coating is applied on the outer metal layer of the current collector.

[0162] In some embodiments, the current collector is coated with a layer of carbonaceous material. Such a layer of carbonaceous material may be part of the coating layer. In some embodiments, the current collector is not coated with a layer of carbonaceous material.

[0163] The thickness of the current collector affects the volume it occupies within the battery, the amount of electrode active material required, and consequently, the battery capacity. In certain embodiments, the current collector has a thickness of approximately 5 μm to 50 μm, 10 μm to 50 μm, 15 μm to 50 μm, 20 μm to 50 μm, 25 μm to 50 μm, 5 μm to 30 μm, 10 μm to 30 μm, 15 μm to 30 μm, 20 μm to 30 μm, 5 μm to 20 μm, 5 μm to 15 μm, 10 μm to 30 μm, 10 μm to 25 μm, or 10 μm to 20 μm.

[0164] In some embodiments, the current collector has a thickness of 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 current collector has a thickness 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.

[0165] In some embodiments, the electrode may be a cathode or an anode. In some embodiments, the electrode layer further comprises an electrode active material.

[0166] In some embodiments, the electrode active material is a cathode active material, and the cathode active material is LiCoO2, LiNiO2, LiNi x Mn y O2, LiCo x Ni y O2, Li 1+z Ni x Mn y Co 1-x-y O2, LiLiLi x Co y Al zThe molecules are selected from the group consisting of O2, LiV2O5, LiTiS2, LiMoS2, LiMnO2, LiCrO2, LiMn2O4, Li2MnO3, LiFeO2, LiFePO4, and combinations thereof, with each x independently ranging from 0.1 to 0.9; each y independently ranging from 0 to 0.9; and each z independently ranging from 0 to 0.4. In a particular embodiment, each x in the above general formula is independently selected from 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875 and 0.9; each y in the above general formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, 0. 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, 0.82 5, 0.85, 0.875, and 0.9 are selected; each z in the above general formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, and 0.4. In some embodiments, each x, y, and z in the above general formula are independently spaced at 0.01 intervals.

[0167] In certain embodiments, the cathode active material is 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 zO2, LiV2O5, LiTiS2, LiMoS2, LiMnO2, LiCrO2, LiMn2O4, LiFeO2, LiFePO4, LiCo x Ni y Selected from the group consisting of O2 and combinations thereof, 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 LiNi x Mn y O2, Li 1+z Ni x Mn y Co 1-x-y O2, LiLiLi x Co y Al z O2 or LiCo x Ni y Instead of O2, here 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) It is O2; -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 is Li of the general formula. 1+x Ni a Mn b Co c Al (1-a-b-c)Having 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, and M is selected from the group consisting of Fe, Co, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, Si, Ge, or combinations thereof. In some embodiments, the cathode active material is selected from the group consisting of LiFePO4, LiCoPO4, LiNiPO4, LiMnPO4, LiMnFePO4, LiMn x Fe (1-x) PO4, and combinations thereof; 0 < x < 1. In some embodiments, the cathode active material is LiNi x Mn y O4; 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 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, and M is selected from the group consisting of Fe, Co, Mn, Ni, and combinations thereof.

[0168] 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.

[0169] 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, LiLiLi 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, LiLiLi 0.7 Mn 0.1 Co 0.2 O2, LiLiLi 0.8 Mn 0.1 Co 0.1 O2 (NMC811), LiNi 0.92 Mn 0.04 Co 0.04 O2, LiLiLi 0.8 Co 0.15 Al 0.05 These are O2 (NCA), LiNiO2 (LNO), or a combination thereof.

[0170] In other embodiments, the cathode active material is not LiCoO2, LiNiO2, LiMnO2, LiMn2O4, or Li2MnO3. In further embodiments, the cathode active material is LiNi 0.33 Mn 0.33 Co 0.33 O2, LiLiLi0.4 Mn 0.4 Co 0.2 O2, LiLiLi 0.5 Mn 0.3 Co 0.2 O2, LiLiLi 0.6 Mn 0.2 Co 0.2 O2, LiLiLi 0.7 Mn 0.15 Co 0.15 O2, LiLiLi 0.7 Mn 0.1 Co 0.2 O2, LiLiLi 0.8 Mn 0.1 Co 0.1 O2, LiLiLi 0.92 Mn 0.04 Co 0.04 O2, or LiLi 0.8 Co 0.15 Al 0.05 It's not O2.

[0171] In certain embodiments, the cathode active material includes or is a core-shell composite material having a core and shell structure, wherein the core and shell are each independently composed 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 bThe material comprises a lithium transition metal oxide selected from the group consisting of O2 and combinations thereof; where -0.2 ≤ x ≤ 0.2, 0 ≤ a < 1, 0 ≤ b < 1, 0 ≤ c < 1, and a + b + c ≤ 1. In a particular embodiment, each x in the above general formula is independently selected from -0.2, -0.175, -0.15, -0.125, -0.1, -0.075, -0.05, -0.025, 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, and 0.2; each a in the above general formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 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 are selected; each b in the above general formula is independently 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0. Selected from 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 general formula is independently 0, 0.025, 0.0 Selected from 5, 0.075, 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875, 0.9, 0.925, 0.95, and 0.975. In some embodiments, each x, a, b, and c in the above general formula independently has an interval of 0.01.In 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 or oxides in the core and shell may be the same, different, or partially different. In some embodiments, the two or more lithium transition metal oxides are uniformly distributed in the core. In certain embodiments, the two or more lithium transition metal oxides are not uniformly distributed in the core. In some embodiments, the cathode active material is not a core-shell composite material.

[0172] 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 contain two or more doped lithium transition metal oxides. In some embodiments, the two or more doped lithium transition metal oxides are uniformly distributed in the core and / or shell. In certain embodiments, the two or more doped lithium transition metal oxides are not uniformly distributed in the core and / or shell.

[0173] In some embodiments, the cathode active material includes or is a core-shell composite material comprising a core containing a lithium transition metal oxide and a shell containing a transition metal oxide. In certain embodiments, the lithium transition metal oxide is 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, LiCoa Ni b O2、LiMn a Ni bO2 is selected from the group consisting of combinations thereof; -0.2 ≤ x ≤ 0.2, 0 ≤ a < 1, 0 ≤ b < 1, 0 ≤ c < 1, and a + b + c ≤ 1. In a particular embodiment, x in the above general formula is independently selected from -0.2, -0.175, -0.15, -0.125, -0.1, -0.075, -0.05, -0.025, 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, and 0.2; each a in the above general formula is independently selected from 0, 0.025, 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0 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 are selected; each b in the above general formula is independently 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 are selected; each c in the above general formula is independently 0, 0.025, 0.0 Selected from 5, 0.075, 0.1, 0.125, 0.15, 0.175, 0.2, 0.225, 0.25, 0.275, 0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, 0.475, 0.5, 0.525, 0.55, 0.575, 0.6, 0.625, 0.65, 0.675, 0.7, 0.725, 0.75, 0.775, 0.8, 0.825, 0.85, 0.875, 0.9, 0.925, 0.95, and 0.975. In some embodiments, each x, a, b, and c in the above general formula independently has an interval of 0.01.In some embodiments, the transition metal oxide is selected from the group consisting of Fe2O3, MnO2, Al2O3, MgO, ZnO, TiO2, La2O3, CeO2, SnO2, ZrO2, RuO2, and combinations thereof. In certain embodiments, the shell comprises lithium transition metal oxide and other transition metal oxides.

[0174] In some embodiments, the core diameter is approximately 1 μm to 15 μm, 3 μm to 15 μm, 3 μm to 10 μm, 5 μm to 10 μm, 5 μm to 45 μm, 5 μm to 35 μm, 5 μm to 25 μm, 10 μm to 45 μm, 10 μm to 40 μm, 10 μm to 35 μm, 10 μm to 25 μm, 15 μm to 45 μm, 15 μm to 30 μm, 15 μm to 25 μm, 20 μm to 35 μm, or 20 μm to 30 μm. In certain embodiments, the shell thickness is approximately 1 μm to 45 μm, approximately 1 μm to 35 μm, approximately 1 μm to 25 μm, approximately 1 μm to 15 μm, approximately 1 μm to 10 μm, approximately 1 μm to 5 μm, approximately 3 μm to 15 μm, approximately 3 μm to 10 μm, approximately 5 μm to 10 μm, approximately 10 μm to 35 μm, approximately 10 μm to 20 μm, approximately 15 μm to 30 μm, approximately 15 μm to 25 μm, or approximately 20 μm to 35 μm. In certain embodiments, the ratio of core to shell diameter or thickness 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.

[0175] In some embodiments, the electrode active material is the anode active material, and the anode active material is natural graphite nanoparticles, synthetic graphite nanoparticles, hard carbon, soft carbon, mesocarbon microbeads (MCMB), Sn nanoparticles, SnO2, SnO, Li4Ti5O 12 The group consists of fine particles, Si fine particles, Si-C composite fine particles, and combinations thereof.

[0176] In certain embodiments, the anode active material is doped with a metallic or nonmetallic element. In some embodiments, the metallic element is selected from the group consisting of Fe, Ni, Mn, Al, Mg, Zn, Ti, La, Ce, Sn, Zr, Ru, and combinations thereof. In some embodiments, the nonmetallic element is B, Si, Ge, N, P, F, S, Cl, I, Se, or combinations thereof.

[0177] In some embodiments, the anode active material includes or is a core-shell composite material having a core and shell structure, wherein the core and shell are independently natural graphite nanoparticles, synthetic graphite nanoparticles, hard carbon, soft carbon, mesocarbon microbeads (MCMB), Sn nanoparticles, SnO2, SnO, Li4Ti5O 12 The group consists of fine particles, Si fine particles, Si-C composite fine particles, and combinations thereof.

[0178] In certain embodiments, the core-shell composite material comprises a core containing a carbonaceous material and a shell covering the carbonaceous material core. In some embodiments, the carbonaceous material is selected from the group consisting of soft carbon, hard carbon, natural graphite nanoparticles, synthetic graphite nanoparticles, mesocarbon microbeads, quiche graphite, pyrolysis carbon, mesophase pitch, mesophase pitch-based carbon fibers, and combinations thereof. In certain embodiments, the shell is natural graphite nanoparticles, synthetic graphite nanoparticles, hard carbon, soft carbon, mesocarbon microbeads (MCMB), Sn nanoparticles, SnO2, SnO, Li4Ti5O 12 The group consists of fine particles, Si fine particles, Si-C composite fine particles, and combinations thereof.

[0179] In certain embodiments, the anode active material is not doped with metallic or nonmetallic 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.

[0180] In some embodiments, the electrode layer may further contain other additives to improve electrode properties. In some embodiments, the additives may include conductive agents, surfactants, dispersants, and flexibility-enhancing additives.

[0181] In some embodiments, the electrode layer further comprises a conductive agent. The conductive agent is intended to enhance the conductivity of the electrode. Any suitable material can act 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 nanoplatelets, carbon fiber, carbon nanofiber, graphitized carbon flakes, carbon tubes, carbon nanotubes, activated carbon, Super P®, 0-dimensional KS6, 1-dimensional vapor-grown carbon fiber (VGCF), mesoporous carbon, and combinations thereof.

[0182] In some embodiments, the electrode layer further comprises a lithium salt. The lithium salt can help increase the ionic conductivity of the electrode layer, thereby reducing the resistance of the electrode. In some embodiments, the lithium salt is selected from the group consisting of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium hexafluorophosphate (LiPF6), lithium fluoroborate (LiBF4), lithium metaborate (LiBO2), lithium perchlorate (LiClO4), lithium nitrate (LiNO3), lithium bis(fluorosulfonyl)imide (LiFSI), lithium iodide (LiI), lithium tetrachloroaluminate (LiAlCl4), lithium difluoro(oxalate)borate (LiBF2C2O4), lithium bis(oxalate)borate (LiBOB), lithium acetate (LiAc), and combinations thereof.

[0183] In some embodiments, the electrode layer further comprises an ion-conducting polymer. The ion-conducting polymer helps to increase the ion 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, poly-lysines, polyester sulfides, polyvinyl alcohols, polyvinylidene fluorides, polymers containing one or more ion-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, polyphasfazenes (PPHOSs), polyurethanes (PUs), copolymers thereof, and combinations thereof.

[0184] 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 an LPS sulfide containing sulfur and phosphorus, for example, Li2S-P2S5;Li 4-x Ge 1-x P x S4 (LGPS, x is 0.1~2); Li 10±1 MP2X 12 (M=Ge, Si, Sn, Al, X=S, Se);Li 3.833 Sn 0.833 As 0.166 S4;Li4SnS4;B2S3-Li2S;xLi2S-(100-x)P2S5(x is 70~80);Li2S-SiS2-Li3N;Li2S-P2S5-LiI;Li2S-SiS2-LiI;Li2S-B2S3-LiI;Li 10 SnP2S 12 ;Li6PS5X Argyrodite(X is halogen);LI 3.25 Ge 0.25 P 0.75 Thio-LISICON compounds such as S4; antiperovskites such as Li3SX (where X is Cl or Br); lithium-phosphorus-iodine-oxygen sulfides; lithium-phosphorus-oxygen sulfides; lithium-zinc-germanium sulfides; lithium-germanium sulfides; LLTO 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-xAl x Si y (PO4) 3-y (Here, 0≦x≦1, 0≦y≦1;LiAl x Zr 2-x (PO4)3 (where 0≦x≦1, 0≦y≦1);LiTi x Zr 2-x (PO4)3 (where 0≦x≦1, 0≦y≦1); LISICON-type solid electrolyte; LIPON compound ( Li 3+y PO 4-x N x The group consists of, where 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 combinations thereof.

[0185] The copolymer binder used in this invention exhibits strong adhesion to the current collector. The good adhesive strength of the copolymer binder to the current collector is important in the fabrication of battery electrodes to promote the bonding force of the electrode layer to the current collector, prevent separation, and improve the mechanical stability of the electrode. In some embodiments, the adhesive strength between the copolymer binder and the current collector is approximately 2 N / cm to 6 N / cm, approximately 2 N / cm to 5.8 N / cm, approximately 2 N / cm to 5.6 N / cm, approximately 2 N / cm to 5.4 N / cm, approximately 2 N / cm to 5.2 N / cm, approximately 2 N / cm to 5 N / cm, approximately 2 N / cm to 4.8 N / cm, approximately 2 N / cm to 4.6 N / cm, approximately 2 N / cm to 4.4 N / cm, approximately 2 N / cm to 4.2 N / cm, and approximately 2 N / cm to 4 N / cm. m, about 2N / cm to about 3.9N / cm, about 2N / cm to about 3.8N / cm, about 2N / cm to about 3.7N / cm, about 2N / cm to about 3.6N / cm, about 2N / cm to about 3.5N / cm, about 2N / cm to about 3.4N / cm, about 2N / c m ~ about 3.3N / cm, about 2N / cm - about 3.2N / cm, about 2N / cm - about 3.1N / cm, about 2N / cm - about 3N / cm, about 2.1N / cm - about 6N / cm, about 2.2N / cm - about 6N / cm, about 2.3N / cm - about 6N / c m, about 2.4N / cm to about 6N / cm, about 2.5N / cm to about 6N / cm, about 2.6N / cm to about 6N / cm, about 2.7N / cm to about 6N / cm, about 2.8N / cm to about 6N / cm, about 2.9N / cm to about 6N / cm, about 3N / c m ~ approx. 6N / cm, approx. 3.1N / cm ~ approx. 6N / cm, approx. 3.2N / cm ~ approx. 6N / cm, approx. 3.3N / cm ~ approx. 6N / cm, approx. 3.4N / cm ~ approx. 6N / cm, approx. 3.5N / cm ~ approx. 6N / cm, approx. 3.6N / cm ~ approx. 6N / cm, approximately 3.7N / cm to approximately 6N / cm, approximately 3.8N / cm to approximately 6N / cm, approximately 3.9N / cm to approximately 6N / cm, approximately 4N / cm to approximately 6N / cm, approximately 2.5N / cm to approximately 5.5N / cm, approximately 2.5N / cm to approximately 5N / cm, approximately 2.5 N / cm to about 4.5N / cm, about 2.5N / cm to about 4N / cm, about 2.5N / cm to about 3.5N / cm, about 3N / cm to about 5N / cm, about 2.2N / cm to about 4.2N / cm, or about 2.2N / cm to about 5.2N / cm.

[0186] In some embodiments, the adhesive strength between the copolymer binder and the current collector is less than 6 N / cm, less than 5.8 N / cm, less than 5.6 N / cm, less than 5.4 N / cm, less than 5.2 N / cm, less than 5 N / cm, less than 4.8 N / cm, less than 4.6 N / cm, less than 4.4 N / cm, less than 4.2 N / cm, less than 4 N / cm, less than 3.9 N / cm, less than 3.8 N / cm, less than 3.7 N / cm, less than 3.6 N / cm, less than 3.5 N / cm, less than 3.4 N / cm, less than 3.3 N / cm, less than 3.2 N / cm, less than 3.1 N / cm, less than 3 N / cm, less than 2.9 N / cm, less than 2.8 N / cm, less than 2.7 N / cm, less than 2.6 N / cm, less than 2.5 N / cm, less than 2.4 N / cm, less than 2.3 N / cm, or less than 2.2 N / cm. In some embodiments, the adhesive 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, and greater than 3.3 N / cm. It exceeds 3.4 N / cm, exceeds 3.5 N / cm, exceeds 3.6 N / cm, exceeds 3.7 N / cm, exceeds 3.8 N / cm, exceeds 3.9 N / cm, exceeds 4 N / cm, exceeds 4.2 N / cm, exceeds 4.4 N / cm, exceeds 4.6 N / cm, exceeds 4.8 N / cm, exceeds 5 N / cm, exceeds 5.2 N / cm, exceeds 5.4 N / cm, exceeds 5.6 N / cm, or exceeds 5.8 N / cm.

[0187] Furthermore, the copolymer binder used in this invention can exhibit strong adhesion between the electrode layer and the current collector in the electrode. Having good peel strength between the electrode layer and the current collector is important because it significantly affects the mechanical stability of the electrode and the cycle life of the battery. Therefore, it is desirable that the electrode has sufficient peel strength to withstand the rigors of battery manufacturing.

[0188] In some embodiments, the peel strength between the current collector and the electrode layer is approximately 1.0 N / cm to 8.0 N / cm, approximately 1.0 N / cm to 6.0 N / cm, approximately 1.0 N / cm to 5.0 N / cm, approximately 1.0 N / cm to 4.0 N / cm, approximately 1.0 N / cm to 3.0 N / cm, approximately 1.0 N / cm to 2.5 N / cm, approximately 1.0 N / cm to 2.0 N / cm, approximately 1.2 N / cm to 3.0 N / cm, approximately 1.2 N / cm to 2.5 N / cm, approximately 1.2 N / cm to 2.0 N / cm, approximately 1.5 N / cm to 3.0 N / cm, and approximately 1.5 N / cm. The ranges are approximately m~2.5N / cm, approximately 1.5N / cm~2.0N / cm, approximately 1.8N / cm~3.0N / cm, approximately 1.8N / cm~2.5N / cm, approximately 2.0N / cm~6.0N / cm, approximately 2.0N / cm~5.0N / cm, approximately 2.0N / cm~3.0N / cm, approximately 2.0N / cm~2.5N / cm, approximately 2.2N / cm~3.0N / cm, approximately 2.5N / cm~3.0N / cm, approximately 3.0N / cm~8.0N / cm, approximately 3.0N / cm~6.0N / cm, or approximately 4.0N / cm~6.0N / cm.

[0189] 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.

[0190] In some embodiments, the surface density of the cathode electrode layer and the anode electrode layer are independently about 1 mg / cm³.2 ~approximately 50mg / cm 2 Approximately 2.5 mg / cm 2 ~approximately 50mg / cm 2 Approximately 5 mg / cm 2 ~approximately 50mg / cm 2 Approximately 7.5 mg / cm³ 2 ~approximately 50mg / cm 2 Approximately 10 mg / cm 2 ~approximately 50mg / cm 2 Approximately 12.5 mg / cm 2 ~approximately 50mg / cm 2 Approximately 15 mg / cm 2 ~approximately 50mg / cm 2 Approximately 17.5 mg / cm³ 2 ~approximately 50mg / cm 2 Approximately 20 mg / cm 2 ~approximately 50mg / cm 2 Approximately 25 mg / cm 2 ~approximately 50mg / cm 2 Approximately 30 mg / cm 2 ~approximately 50mg / cm 2 Approximately 1 mg / cm 2 ~approximately 30mg / cm 2 Approximately 2.5 mg / cm 2 ~approximately 30mg / cm 2 Approximately 5 mg / cm 2 ~approximately 30mg / cm 2 Approximately 7.5 mg / cm³ 2 ~approximately 30mg / cm 2 Approximately 10 mg / cm 2 ~approximately 30mg / cm 2 Approximately 12.5 mg / cm 2 ~approximately 30mg / cm 2 Approximately 15 mg / cm 2 ~approximately 30mg / cm 2 Approximately 17.5 mg / cm³ 2 ~approximately 30mg / cm 2 Approximately 20 mg / cm 2 ~approximately 30mg / cm 2 Approximately 1 mg / cm 2 ~approximately 20 mg / cm 2 Approximately 2.5 mg / cm 2 ~approximately 20 mg / cm 2 Approximately 5 mg / cm 2 ~approximately 20 mg / cm2 , about 7.5mg / cm 2 ~about 20mg / cm 2 , about 10mg / cm 2 ~about 20mg / cm 2 , about 12.5mg / cm 2 ~about 20mg / cm 2 , about 1mg / cm 2 ~About 15mg / cm 2 , about 2.5mg / cm 2 ~About 15mg / cm 2 , about 5mg / cm 2 ~About 15mg / cm 2 , about 7.5mg / cm 2 ~About 15mg / cm 2 , or approximately 10 mg / cm³ 2 ~About 15mg / cm 2 That is the case.

[0191] In some embodiments, the surface density of the cathode electrode layer and the anode electrode layer are independently 50 mg / cm³. 2 Less than 45 mg / cm³ 2 Less than 35 mg / cm³ 2 Less than 30 mg / cm³ 2 Less than 25 mg / cm³ 2 Less than 20 mg / cm³ 2 Less than 17.5 mg / cm³ 2 Less than 15 mg / cm³ 2 Less than 12.5 mg / cm³ 2 Less than 10 mg / cm³ 2 Less than 7.5 mg / cm³ 2 Less than 5 mg / cm³ 2 Less than 2.5 mg / cm³ 2 It is less than 1 mg / cm³. In some embodiments, the surface density of the cathode electrode layer and the anode electrode layer are independently 1 mg / cm³. 2 Exceeding 2.5 mg / cm³ 2 Exceeding 5 mg / cm³ 2 Exceeding 7.5 mg / cm³ 2 Exceeding 10 mg / cm³ 2 Exceeding 12.5 mg / cm³ 2 Exceeding 15 mg / cm³ 2 Exceeding 17.5 mg / cm³ 2Exceeding 20 mg / cm³ 2 Exceeding 25 mg / cm³ 2 Exceeding 30 mg / cm³ 2 Exceeding 35 mg / cm³ 2 Exceeding, or 40 mg / cm³ 2 It exceeds.

[0192] In some embodiments, the density of the cathode electrode layer and the anode electrode layer are independently about 0.5 g / cm³. 3 ~Approx. 7.5g / cm 3 , about 1g / cm 3 ~Approx. 7.5g / cm 3 , about 1.5g / cm 3 ~Approx. 7.5g / cm 3 , about 2g / cm 3 ~Approx. 7.5g / cm 3 , about 2.5g / cm 3 ~Approx. 7.5g / cm 3 , about 3g / cm 3 ~Approx. 7.5g / cm 3 , about 3.5g / cm 3 ~Approx. 7.5g / cm 3 Approximately 4 g / cm³ 3 ~Approx. 7.5g / cm 3 , about 4.5g / cm 3 ~Approx. 7.5g / cm 3 , about 5g / cm 3 ~Approx. 7.5g / cm 3 , about 0.5g / cm 3 ~about 5g / cm 3 , about 1g / cm 3 ~about 5g / cm 3 , about 1.5g / cm 3 ~about 5g / cm 3 , about 2g / cm 3 ~about 5g / cm 3 , about 2.5g / cm 3 ~about 5g / cm 3 , about 3g / cm 3 ~about 5g / cm 3 , about 0.5g / cm 3 ~Approx. 2.5g / cm 3 , about 1g / cm 3 ~Approx. 2.5g / cm 3 , or approximately 1.5 g / cm³3 ~Approx. 2.5g / cm 3 That is the case.

[0193] In some embodiments, the density of the cathode electrode layer and the anode electrode layer are independently 7.5 g / cm³. 3 Less than 7 g / cm³ 3 Less than 6.5 g / cm³ 3 Less than 6 g / cm³ 3 Less than 5.5 g / cm³ 3 Less than 5 g / cm³ 3 Less than 4.5 g / cm³ 3 Less than 4 g / cm³ 3 Less than 3.5 g / cm³ 3 Less than 3 g / cm³ 3 Less than 2.5 g / cm³ 3 Less than 2 g / cm³ 3 Less than 1.5 g / cm³ 3 It is less than 0.5 g / cm³. In some embodiments, the density of the cathode electrode layer and the anode electrode layer are independently 0.5 g / cm³. 3 Exceeding 1 g / cm³ 3 Exceeding 1.5 g / cm³ 3 Exceeding 2g / cm³ 3 Exceeding 2.5 g / cm³ 3 Exceeding 3g / cm³ 3 Exceeding 3.5 g / cm³ 3 Exceeding 4g / cm³ 3 Exceeding 4.5 g / cm³ 3 Exceeding 5g / cm³ 3 Exceeding 5.5 g / cm³ 3 Exceeding 6g / cm³ 3 If it exceeds 6.5 g / cm³, or 6.5 g / cm³ 3 It exceeds.

[0194] In some embodiments, a battery containing electrodes to be stripped is first disassembled into one or more battery pieces, each of which contains one or more electrode pieces. There are no particular limitations on the method used to disassemble the battery, except that the minimum size of the resulting battery pieces is preferably larger than the sieve hole size used to sieve the composite material-stripping solution mixture after stripping, in order to ensure the pieces can be sieved. In some embodiments, a crusher, mill, or cutter is used to disassemble the battery. In some embodiments, a water jet is used to disassemble the battery. In some embodiments, cryogenic treatment of the battery is performed before disassembly, for example, with liquid nitrogen. In some embodiments, the battery is discharged first. In some embodiments, the battery is discharged by immersion in a salt solution. In other embodiments, if a water jet is used to disassemble the battery and / or if cryogenic treatment of the battery is performed before disassembly, battery discharge is not necessary.

[0195] In some embodiments, when a battery piece is immersed in a stripping solution to achieve electrode stripping, the weight ratio of the battery piece to the stripping solution is approximately 0.01% to approximately 50%, approximately 0.02% to approximately 50%, approximately 0.05% to approximately 50%, approximately 0.1% to approximately 50%, approximately 0.2% to approximately 50%, approximately 0.5% to approximately 50%, approximately 1% to approximately 50%, approximately 2% to approximately 50%, approximately 5% to approximately 50%, approximately 10% to approximately 50%, approximately 15% to approximately 50%, approximately 20% to approximately 50%, approximately 25% to approximately 50%, approximately 30% to approximately 50%, and approximately 0.01% to approximately The percentages are 25%, approximately 0.02% to 25%, approximately 0.05% to 25%, approximately 0.1% to 25%, approximately 0.2% to 25%, approximately 0.5% to 25%, approximately 1% to 25%, approximately 2% to 25%, approximately 5% to 25%, approximately 10% to 25%, approximately 0.1% to 15%, approximately 0.2% to 15%, approximately 0.5% to 15%, approximately 1% to 15%, approximately 2% to 15%, approximately 5% to 15%, approximately 0.1% to 5%, approximately 0.2% to 5%, approximately 0.5% to 5%, approximately 1% to 5%, or approximately 2% to 5%.

[0196] In some embodiments, when a battery piece is immersed in a stripping solution to achieve electrode stripping, the weight ratio of the battery piece 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 a battery piece is immersed in a stripping solution to achieve electrode stripping, the weight ratio of the battery piece 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%.

[0197] In other embodiments, the electrode pieces are separated from the rest of the battery piece after disassembly and before peeling. In some embodiments, after separating the electrode pieces from the rest of the battery piece, only the electrode pieces are subjected to peeling.

[0198] In some embodiments, when only the electrode piece is immersed in the stripping solution to achieve electrode stripping, the weight ratio of the electrode piece to the stripping solution is approximately 0.01% to approximately 50%, approximately 0.02% to approximately 50%, approximately 0.05% to approximately 50%, approximately 0.1% to approximately 50%, approximately 0.2% to approximately 50%, approximately 0.5% to approximately 50%, approximately 1% to approximately 50%, approximately 2% to approximately 50%, approximately 5% to approximately 50%, approximately 10% to approximately 50%, approximately 15% to approximately 50%, approximately 20% to approximately 50%, approximately 25% to approximately 50%, approximately 30% to approximately 50%, approximately 0.01% to approximately The percentages are 25%, approximately 0.02% to 25%, approximately 0.05% to 25%, approximately 0.1% to 25%, approximately 0.2% to 25%, approximately 0.5% to 25%, approximately 1% to 25%, approximately 2% to 25%, approximately 5% to 25%, approximately 10% to 25%, approximately 0.1% to 15%, approximately 0.2% to 15%, approximately 0.5% to 15%, approximately 1% to 15%, approximately 2% to 15%, approximately 5% to 15%, approximately 0.1% to 5%, approximately 0.2% to 5%, approximately 0.5% to 5%, approximately 1% to 5%, or approximately 2% to 5%.

[0199] In some embodiments, when only the electrode piece is immersed in the stripping solution to achieve electrode detachment, the weight ratio of the electrode piece 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 piece is immersed in the stripping solution to achieve electrode detachment, the weight ratio of the electrode piece 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%.

[0200] By utilizing the method of the present invention in the stripping of electrodes containing copolymer binders, a 100% stripping success rate, an exceptionally high recovery rate (>99%), and rapid removal of electrodes from current collectors can be achieved. layer This results in delamination (<60s).

[0201] In some embodiments, electrode delamination occurs along the electrode layer-current collector interface. The delamination success rate refers to the degree of delamination of the electrode layer from the current collector. The success rate is calculated by the following formula:

[0202]

number

[0203] After the peeling reaction, the mass of the electrode layer present in the peeling solution corresponds to the mass of the electrode layer that was successfully peeled off. The mass of the electrode layer remaining coated on the current collector is the mass of the electrode layer remaining on the current collector, and this remaining electrode layer can be measured by manually scraping it off and measuring the mass of the scraped-off contents. In the present invention, where the electrode layer is completely peeled off from the current collector, the peeling success rate is 100%. In other cases, where the electrode layer is not peeled off from the current collector, or where the electrode layer is partially peeled off from the current collector and visible deposits of the electrode layer remain on the current collector, the success rate is less than 100%.

[0204] Recovery rate refers to the ratio of the sum of the weights of the successfully recovered electrode layer and current collector to the initial weight of the electrode before immersion in the stripping solution. Recovery rate is calculated only when the success rate exceeds 75%. This is because below this value, stripping is considered ineffective and not economically viable enough to warrant consideration in an industrial context. Recovery rate reflects the degree of corrosion of the valuable metallic material in the electrode and / or the degree of dissolution of the valuable metallic material in the stripping solution. The method disclosed herein yields a high recovery rate and demonstrates that the degree of corrosion or dissolution of metallic electrode material such as the current collector in the stripping solution is negligible.

[0205] This invention provides a simple method that can be used to separate the electrode layer from the current collector, taking into account the composition of the copolymer binder used. Since the separation of the electrode layer from the current collector constitutes a critical step in battery recycling, the method disclosed herein presents a technical solution to meet the demands in battery recycling. The method of this invention avoids both complex separation processes and contamination of the current collector, enabling excellent material recovery (i.e., high recovery rate).

[0206] The method disclosed in this invention significantly reduces the time required to separate the electrode layer from the current collector in a battery without damaging the underlying current collector. Shorter contact time between the electrode and the stripping solution may prevent corrosion of the current collector and other electrode materials, such as electrode active materials and metals. For example, when an electrode containing an aluminum current collector is immersed in a strongly base-containing stripping solution, shorter contact time allows the native oxide film formed on the surface of the aluminum current collector to achieve sufficient protection against corrosion.

[0207] The method of the present invention can also be applied to achieve the removal of packaging material by immersing the packaging material in a release solution, wherein the packaging material comprises a metal and a coating layer covering one or both sides of the metal, and the coating comprises a copolymer binder.

[0208] The coating layer may include metal, plastic, paper, and possibly cardboard. The metal and coating layers are separated from each other by treating the packaging material with a strong base-containing stripping solution. The method disclosed herein can be used to strip a wide range of packaging materials, particularly food and beverage packaging, to result in the recovery and recycling of individual material components used in packaging.

[0209] The following examples are provided to illustrate embodiments of the present invention, but are not intended to limit the invention to any particular embodiment shown. Unless otherwise indicated, all parts and percentages are by weight. All numerical values ​​are approximate. Where a numerical range is given, it should be understood that embodiments outside that range may still fall within the scope of the invention. Specific details described in each example should not be construed as essential features of the invention.

[0210] (example) The pH value of the electrode-stripping solution mixture after stripping was measured using an electrode-type pH meter (ION2700, Eutech Instruments).

[0211] The recovery rate refers to the ratio of the sum of the weights of the recovered electrode layer and the current collector, based on the initial weight of the electrode before immersion in the stripping solution.

[0212] The delamination success rate indicates the extent to which the electrode layer has detached from the current collector. The delamination success rate can be calculated using the following formula.

[0213]

number

[0214] Therefore, after the peeling reaction was completed or stopped, the electrode layer present in the peeling solution was recovered to determine the mass of the successfully peeled electrode layer, and (if any) any remaining electrode layer material on the electrode was manually scraped off to determine the mass of the electrode layer remaining on the current collector.

[0215] The adhesive strength of the dried binder layer was measured using a tensile testing machine (DZ-106A, Dongguan Zonhow Test Equipment Co. Ltd., obtained from China). This test measures the average force required to peel the binder layer from the current collector at a 180° angle, measured in Newtons. The average roughness depth (Rz) of the current collector was 2 μm. Copolymer binder was applied to the current collector and dried to obtain a binder layer with a thickness of 10 μm to 12 μm. Next, the coated current collector was placed in a constant temperature environment of 25°C and 50% to 60% humidity for 30 minutes. A piece of adhesive tape (3M; USA; model number 810) with a width of 18 mm and a length of 20 mm was attached to the surface of the binder layer. The binder piece was placed in the testing machine, the tape was folded over itself at a 180° angle, placed in the movable jaws, and pulled at a peeling speed of 300 mm per minute at room temperature. The measured maximum peeling force was defined as the adhesive strength. The measurement was repeated three times, and the average value was calculated.

[0216] The peel strength of the dried electrode layer was measured using a tensile testing machine (DZ-106A, Dongguan Zonhow Test Equipment Co. Ltd., obtained from China). This test measures the average force required to peel the electrode layer from the current collector at a 180° angle, measured in Newtons. The average roughness depth (Rz) of the current collector was 2 μm. A strip of adhesive tape (3M; USA; model number 810), 18 mm wide and 20 mm long, was attached to the surface of the cathode electrode layer. This cathode piece was placed in the testing machine, the tape was folded over itself at a 180° angle, placed in the movable jaws, and pulled at a peeling speed of 200 mm per minute at room temperature. The maximum peeling force measured was defined as the peel strength. The measurement was repeated three times, and the average value was calculated.

[0217] (Example 1) Assembly of pouch-type full lithium-ion batteries A) Preparation of copolymer binder 18.15 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 the first suspension.

[0218] 36.04 g of acrylic acid was added to the first suspension. The mixture was further stirred at 80 rpm for 30 minutes to obtain the second suspension.

[0219] An acrylamide solution was prepared by dissolving 19.04 g of acrylamide in 10 g of DI water. Then, 29.04 g of the acrylamide solution was added to the second suspension. The mixture was further heated to 55°C and stirred at 80 rpm for 45 minutes to obtain a third suspension.

[0220] 12.92 g of acrylonitrile was added to the third suspension. The mixture was further stirred at 80 rpm for 10 minutes to obtain the fourth suspension.

[0221] Furthermore, 0.015 g of a water-soluble free radical initiator (ammonium persulfate, APS; obtained from Aladdin Industries Corporation, China) was dissolved in 3 g of DI 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 DI water. 3.015 g of APS solution and 1.5075 g of sodium bisulfite solution were added to the fourth suspension. The mixture was stirred at 200 rpm at 55°C for 24 hours to obtain the fifth suspension.

[0222] After the reaction was complete, the temperature of the fifth suspension was lowered to 25°C. 3.72 g of NaOH was dissolved in 400 g of DI water. Then, 403.72 g of sodium hydroxide solution was added dropwise to the fifth suspension to adjust the pH to 7.3 and prepare the sixth suspension. The sixth suspension was filtered through a 200 μm nylon mesh to prepare the binder material. The solid content of the binder material was 9.00 wt%. The adhesive strength between the copolymer binder and the current collector was 3.27 N / cm. The components of the copolymer binder of Example 1 and their respective proportions are shown in Table 1 below.

[0223] B) Preparation of the positive electrode A first mixture was prepared by dispersing 12 g of conductive agent (Super P®; obtained from Timcal Ltd, Bordio, Switzerland) and 100 g of binder material (solids content 9.00 wt%) in 74 g of deionized water while stirring with an overhead stirrer (R20, IKA). After addition, the first mixture was further stirred at a speed of 1,200 rpm for approximately 30 minutes at 25°C.

[0224] Subsequently, 276 g of NMC532 (obtained 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 the second mixture. The second mixture was then degassed under a pressure of approximately 10 kPa for 1 hour. The second mixture was then further stirred at 1,200 rpm at 25°C for approximately 60 minutes to prepare a homogenized cathode slurry.

[0225] A homogenized cathode slurry was applied to both sides of a 16 μm thick aluminum foil current collector using a doctor blade coater, with a gap width of 120 μm. The 80 μm slurry applied to the aluminum foil was dried in an electric furnace at 85°C to create a cathode electrode layer. The drying time was approximately 120 minutes. Next, the electrode was pressed to reduce the thickness of the cathode electrode layer to 34 μm. The surface density of the cathode electrode layer on the current collector was 16.00 mg / cm³. 2 That was the case.

[0226] C) Preparation of the negative electrode A negative electrode slurry was prepared by mixing 93 wt% graphite (BTR New Energy Materials Inc., Shenzhen, Guangdong, China) with 1 wt% carboxymethylcellulose (CMC, BSH-12, DKS Co. Ltd., Japan), 3 wt% SBR (AL-2001, NIPPON A&L INC., Japan) as a binder, and 3 wt% carbon black as a conductive agent in deionized water. The solid content of the anode slurry was 51.5 wt%. The slurry was applied to both sides of an 8 μm thick copper foil with a gap width of approximately 120 μm using a doctor blade coater. The slurry applied to the copper foil was dried in a hot air dryer at approximately 85°C for 120 minutes to obtain the negative electrode. The electrode was then pressed to reduce the thickness of the anode electrode layer to 60 μm, and the surface density of the anode electrode layer was reduced to 10 mg / cm³. 2 That was it.

[0227] D) Assembly of pouch-type batteries After drying, the obtained cathode and anode coatings were cut into rectangular pieces measuring 5.2 cm × 8.5 cm and 5.4 cm × 8.7 cm to prepare cathode and anode sheets, respectively. The cathode and anode sheets were stacked alternately and separated with a porous polyethylene separator (Celgard, LLC, USA) with a thickness of 25 μm to prepare a pouch-type battery. The electrolyte used was LiPF6 (1M) dissolved in a mixture of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC) in a volume ratio of 1:1:1. The cells were assembled in a high-purity argon atmosphere with a moisture and oxygen content of <1 ppm. After filling with the electrolyte, the pouch cells were vacuum-sealed and then mechanically pressed using a standard-shaped punching tool.

[0228] Next, the assembled pouch-type battery was subjected to repeated charge-discharge cycles at a constant current rate of 1C at 3.0V to 4.2V, simulating actual usage patterns. The actual cell capacity was approximately 5Ah. After 800 cycles, the nominal capacity had decreased to less than 80% of the initial rated capacity.

[0229] Battery recycling A) Discharging and disassembling pouch-type batteries The lithium-ion battery (0.5 kg) used was completely discharged by immersing it in a 6% NaCl solution for 12 hours. After discharge, the lithium-ion battery was mechanically disassembled using a cutter and the electrodes were recovered. The electrodes were cut into small pieces with an average length of approximately 2 cm to 4 cm.

[0230] B) Preparation of the stripping solution 2.00 g of anhydrous sodium hydroxide (Sigma-Aldrich, USA) was added to 1000 g of DI water to prepare a stripping solution with a concentration of 0.05 M.

[0231] C) Immersion of the cathode in the stripping solution. 5.07 g of cathode was placed in a container containing 1000 g of stripping solution heated at 25°C. The cathode layer was peeled off the aluminum foil. After confirming that the cathode layer had been completely peeled off, the stripping solution containing sodium hydroxide and DI water was removed by passing it through a 4 mm mesh sieve, and the cathode layer and aluminum foil were recovered. The stripping solution could be reused for further electrode stripping. The recovered cathode layer and aluminum foil were dried in an oven at atmospheric pressure at 80°C for 5 hours, achieving a recovery rate of 99.56%. The success rate of stripping and the recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0232] Assembly of pouch-type full lithium-ion batteries in Examples 2-4 A pouch-type lithium-ion battery was fabricated using the method described in Example 1. The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 1.

[0233] Battery recycling in Example 2 A) Discharging and disassembling pouch-type batteries The lithium-ion battery used was discharged and disassembled using the same method as described in Example 1.

[0234] B) Preparation of the stripping solution A 0.10 M stripping solution was prepared by adding 4.00 g of anhydrous sodium hydroxide (Sigma-Aldrich, USA) to 1000 g of DI water.

[0235] C) Immersion of the cathode in the stripping solution. Except for using the stripping solution described above, the cathode was immersed and stripped using the method described in Example 1. The stripping success rate and the recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0236] Battery recycling in Example 3 A) Discharging and disassembling pouch-type batteries The lithium-ion battery used was discharged and disassembled using the same method as described in Example 1.

[0237] B) Preparation of the stripping solution A 0.20 M stripping solution was prepared by adding 8.00 g of anhydrous sodium hydroxide (Sigma-Aldrich, USA) to 1000 g of DI water.

[0238] C) Immersion of the cathode in the stripping solution. Except for using the stripping solution described above, the cathode was immersed and stripped using the method described in Example 1. The stripping success rate and the recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0239] Battery recycling in Example 4 A) Discharging and disassembling pouch-type batteries The lithium-ion battery used was discharged and disassembled using the same method as described in Example 1.

[0240] B) Preparation of the stripping solution A 0.50 M stripping solution was prepared by adding 20.0 g of anhydrous sodium hydroxide (Sigma-Aldrich, USA) to 1000 g of DI water. C) Immersion of the cathode in the stripping solution. Except for using the stripping solution described above, the cathode was immersed and stripped using the method described in Example 1. The stripping success rate and the recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0241] Assembly of pouch-type full lithium-ion batteries in Examples 5-7 A pouch-type lithium-ion battery was fabricated using the method described in Example 2. The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 2.

[0242] Battery recycling in Example 5 Battery recycling was performed in the same manner as in Example 2, except that the stripping solution was heated to 50°C. The stripping success rate and the recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0243] Battery recycling in Example 6 Battery recycling was performed in the same manner as in Example 2, except that the stripping solution was heated to 90°C. The stripping success rate and the recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0244] Battery recycling in Example 7 A) Discharging and disassembling pouch-type batteries The lithium-ion battery used was discharged and disassembled using the same method as described in Example 2.

[0245] B) Preparation of the stripping solution 5.61 g of anhydrous potassium hydroxide (Sigma-Aldrich, USA) was added to 1000 g of DI water to prepare a stripping solution with a concentration of 0.10 M.

[0246] C) Immersion of the cathode in the stripping solution. Except for using the stripping solution described above, the cathode was immersed and stripped using the method described in Example 2. The stripping success rate and the recovery rate of the cathode material after stripping were measured and are shown in Table 1 below.

[0247] Preparation of polymer binder in Example 8 A pouch-type lithium-ion battery was prepared in the same manner as in Example 2, except that 26.46 g of sodium hydroxide was added in the preparation of the first suspension, 51.02 g of acrylic acid was added in the preparation of the second suspension, 10.78 g of acrylamide was added in the preparation of the third suspension, and 8.05 g of acrylonitrile was added in the preparation of the fourth suspension. The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 2.

[0248] Preparation of polymer binder in Example 9 In preparing the polymer binder, a pouch-type lithium-ion battery was prepared in the same manner as in Example 2, except that 18.37 g of sodium hydroxide was added in the preparation of the first suspension, 36.44 g of acrylic acid was added in the preparation of the second suspension, 15.82 g of acrylamide was added in the preparation of the third suspension, and 15.03 g of acrylonitrile was added in the preparation of the fourth suspension. The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 2.

[0249] Preparation of polymer binder in Example 10 A pouch-type lithium-ion battery was prepared in the same manner as in Example 2, except that 18.37 g of sodium hydroxide was added in the preparation of the first suspension, 36.44 g of acrylic acid was added in the preparation of the second suspension, 20.13 g of acrylamide was added in the preparation of the third suspension, and 11.81 g of acrylonitrile was added in the preparation of the fourth suspension. The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 2.

[0250] Assembly of pouch-type full lithium-ion batteries (Examples 8-10) A) Creating the positive electrode The cathodes of Examples 8-10 were fabricated using the method described in Example 2, except that the binder materials prepared in Examples 8-10 were used individually to produce the cathodes of Examples 8-10. B) Fabrication of the negative electrode The negative electrode was fabricated using the method described in Example 2. C) Assembly of pouch-type batteries A pouch-type lithium-ion battery was fabricated using the method described in Example 2. The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 2.

[0251] Assembly of a pouch-type full lithium-ion battery in Example 11 A pouch-type lithium-ion battery was fabricated using the method described in Example 2, except that 276g of NMC532 was replaced with the same weight of LCO. The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 2.

[0252] Assembly of a pouch-type full lithium-ion battery in Example 12 A pouch-type lithium-ion battery was fabricated using the method described in Example 2, except that 276g of NMC532 was replaced with the same weight of LFP (Tianjin Sitelan Energy Technology Co. Ltd., China). The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 2.

[0253] Assembly of a pouch-type full lithium-ion battery in Example 13 A pouch-type lithium-ion battery was prepared using the method described in Example 2, except that 36.04 g of acrylic acid was replaced with 50.08 g of 2-ethylacrylic acid in the preparation of the second suspension of the polymer binder. The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 2.

[0254] Assembly of a pouch-type full lithium-ion battery in Example 14 A pouch-type lithium-ion battery was prepared in the same manner as in Example 2, except that 36.04 g of acrylic acid was replaced with 54.08 g of vinyl sulfonic acid in the preparation of the second suspension. The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 2.

[0255] Battery recycling for examples 8-14 Battery recycling was performed in the same manner as in Example 2. The success rate of delamination and the recovery rate of the cathode material after delamination were measured and are shown in Table 1 below.

[0256] Preparation of polymer binder in Example 15 A pouch-type lithium-ion battery was prepared in the same manner as in Example 4, except that 10.68 g of sodium hydroxide was added in the preparation of the first suspension, 22.60 g of acrylic acid was added in the preparation of the second suspension, 6.47 g of acrylamide was added in the preparation of the third suspension, and 32.20 g of acrylonitrile was added in the preparation of the fourth suspension. The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 4.

[0257] Preparation of polymer binder in Example 16 A pouch-type lithium-ion battery was prepared in the same manner as in Example 4, except that 14.32 g of sodium hydroxide was added in the preparation of the first suspension, 29.16 g of acrylic acid was added in the preparation of the second suspension, 12.22 g of acrylamide was added in the preparation of the third suspension, and 23.08 g of acrylonitrile was added in the preparation of the fourth suspension. The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 4.

[0258] Assembly of pouch-type full lithium-ion batteries (Examples 15-16) A) Creating the positive electrode The cathodes of Examples 15-16 were manufactured using the binder materials prepared in Examples 15-16, respectively, but the positive electrodes were prepared using the method described in Example 4.

[0259] B) Creation of the negative electrode The negative electrode was fabricated using the method described in Example 4.

[0260] C) Assembly of pouch-type batteries A pouch-type lithium-ion battery was fabricated using the method described in Example 4. The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 4.

[0261] Battery recycling in Examples 15-16 Battery recycling was performed in the same manner as in Example 4. The success rate of delamination and the recovery rate of the cathode material after delamination were measured and are shown in Table 1 below.

[0262] Assembly of the pouch-type full lithium-ion battery in Comparative Example 1 A) Fabrication of the positive electrode In a 500 mL round-bottom flask, 10 g of polyvinylidene fluoride, PVDF (Solef® 5130, Solvay SA, obtained from Belgium), a polymer binder, was dispersed in 250 g of N-methyl-2-pyrrolidone, NMP (≧99%, Sigma-Aldrich, USA) while stirring with an overhead stirrer at 500 rpm for approximately 3 hours to prepare the first suspension.

[0263] Subsequently, 15 g of Super P® was added to the first suspension and stirred at 1,200 rpm for 30 minutes to obtain the second suspension.

[0264] A third suspension was prepared by dispersing 225 g of NMC532 in 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 25°C for approximately 90 minutes at a speed of 1,200 rpm to prepare a homogenized cathode slurry.

[0265] Homogenized cathode slurry was applied to both sides of a 16 μm thick aluminum foil current collector using a doctor blade coater, with a gap width of 120 μm. The 80 μm slurry applied to the aluminum foil was dried in an 85°C electric oven to form the cathode electrode layer. The drying time was approximately 120 minutes. Subsequently, the electrodes were pressed to reduce the thickness of the cathode electrode layer to 34 μm.

[0266] B) Fabrication of the negative electrode The negative electrode was fabricated using the same method as in Example 2.

[0267] C) Assembly of pouch-type batteries A pouch-type battery was assembled using the same method as in Example 2. Then, the assembled pouch-type battery was subjected to repeated cycles using the same method as in Example 2.

[0268] Battery recycling in Comparative Example 1 If the delamination was not complete, the reaction was stopped after 10 minutes; otherwise, the battery was recycled in the same manner as in Example 2. The delamination success rate and the recovery rate of the cathode material after delamination were measured and are shown in Table 2 below.

[0269] Assembly of the pouch-type full lithium-ion battery in Comparative Example 2 A pouch-type lithium-ion battery was fabricated using the method described in Example 2. The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 2.

[0270] Battery recycling in Comparative Example 2 Battery recycling was carried out in the same manner as in Example 2, except that in the preparation of the stripping solution, only 1000g of DI water was added and no stripping agent was added. If the stripping was not complete, the reaction was stopped after 10 minutes. The stripping success rate and the recovery rate of the cathode material after stripping were measured and are shown in Table 2 below.

[0271] Assembly of the pouch-type full lithium-ion battery in Comparative Example 3 In the preparation of the copolymer binder, a pouch-type lithium-ion battery was prepared in the same manner as in Example 2, except that 7.45 g of sodium hydroxide was added in the preparation of the first suspension, 16.77 g of acrylic acid was added in the preparation of the second suspension, 7.19 g of acrylamide was added in the preparation of the third suspension, and 35.95 g of acrylonitrile was added in the preparation of the fourth suspension. The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 2.

[0272] Assembly of the pouch-type full lithium-ion battery in Comparative Example 4 In the preparation of the polymer binder, a pouch-type lithium-ion battery was prepared in the same manner as in Example 2, except that 30.51 g of sodium hydroxide was added in the preparation of the first suspension, 58.31 g of acrylic acid was added in the preparation of the second suspension, no acrylamide was added in the preparation of the third suspension, and 10.73 g of acrylonitrile was added in the preparation of the fourth suspension. The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 2.

[0273] Assembly of the pouch-type full lithium-ion battery in Comparative Example 5 In the preparation of the polymer binder, a pouch-type lithium-ion battery was prepared in the same manner as in Example 2, except that 24.44 g of sodium hydroxide was added in the preparation of the first suspension, 47.38 g of acrylic acid was added in the preparation of the second suspension, 25.16 g of acrylamide was added in the preparation of the third suspension, and acrylonitrile was not added in the preparation of the fourth suspension. The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 2.

[0274] Assembly of the pouch-type full lithium-ion battery in Comparative Example 6 In preparing the polymer binder, a pouch-type lithium-ion battery was prepared in the same manner as in Example 2, except that 16.35 g of sodium hydroxide was added in the preparation of the first suspension, 32.80 g of acrylic acid was added in the preparation of the second suspension, 28.76 g of acrylamide was added in the preparation of the third suspension, and 8.05 g of acrylonitrile was added in the preparation of the fourth suspension. The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 2.

[0275] Assembly of the pouch-type full lithium-ion battery in Comparative Example 7 In the preparation of the polymer binder, a pouch-type lithium-ion battery was prepared in the same manner as in Example 2, except that 10.28 g of sodium hydroxide was added in the preparation of the first suspension, 21.87 g of acrylic acid was added in the preparation of the second suspension, 3.59 g of acrylamide was added in the preparation of the third suspension, and 34.89 g of acrylonitrile was added in the preparation of the fourth suspension. The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 2.

[0276] Assembly of a pouch-type full lithium-ion battery in Comparative Example 8 In the preparation of the polymer binder, a pouch-type lithium-ion battery was prepared in the same manner as in Example 2, except that 4.21 g of sodium hydroxide was added in the preparation of the first suspension, 10.93 g of acrylic acid was added in the preparation of the second suspension, 21.57 g of acrylamide was added in the preparation of the third suspension, and 29.52 g of acrylonitrile was added in the preparation of the fourth suspension. The assembled pouch-type battery was then subjected to repeated cycles in the same manner as in Example 2.

[0277] Battery recycling for Comparative Examples 3-8 If the delamination was not complete, the battery recycling was performed in the same manner as in Example 2, except that the reaction was stopped after 10 minutes. The delamination success rate and the recovery rate of the cathode material after delamination were measured and are shown in Table 2 below.

[0278] [Table 1]

[0279] [Table 2]

[0280] Although the present invention has been described in relation to a limited number of embodiments, the specific features of one embodiment should not be determined by other embodiments of the invention. In some embodiments, the method may include a number of steps not mentioned herein. In other embodiments, the method does not include, or substantially does not include, any steps not enumerated herein. Modifications and improvements from the embodiments described exist. The appended claims are intended to cover all of these improvements and modifications within the scope of the invention. The invention described in the original claims of this application is listed below. [1] A method for peeling a composite material by immersing the composite material in a peeling solution; the composite material comprises a metal substrate and a coating applied to one or both sides of the metal substrate, wherein the coating comprises a copolymer binder; and the copolymer binder comprises structural units (a) obtained from monomers selected from the group consisting of carboxylic acid group-containing monomers, sulfonic acid group-containing monomers, phosphonic acid group-containing monomers, carboxylic acid base-containing monomers, sulfonic acid base-containing monomers, phosphonic acid base-containing monomers, and combinations thereof. [2] The method according to [1], wherein the stripping solution comprises a stripping agent and an aqueous solvent; the concentration of the stripping agent in the stripping solution is about 0.05 to 2 M. [3] The method according to [2], wherein the stripping agent is selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, lithium oxide, sodium oxide, potassium oxide, rubidium oxide, cesium oxide, calcium oxide, strontium oxide, barium oxide, and combinations thereof. [4] The method described in [2], wherein the aqueous solvent is water. [5] The aqueous solvent contains water as the main component and trace components, and the proportion of water in the aqueous solvent is greater than 51% by weight and less than 100% by weight. The method according to [2], wherein the trace component is selected from the group consisting of methanol, ethanol, isopropanol, n-propanol, tert-butanol, n-butanol, acetone, dimethyl ketone, methyl ethyl ketone, ethyl acetate, isopropyl acetate, propyl acetate, butyl acetate, and combinations thereof. [6] The method according to [1], wherein the proportion of the structural unit (a) in the copolymer is about 30 mol% to about 80 mol%, based on the total number of moles of monomer units in the copolymer binder. [7] The carboxylic acid group-containing monomers include acrylic acid, methacrylic acid, crotonic acid, 2-butylcrotonic acid, cinnamic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, tetraconic acid, 2-ethylacrylic acid, isocrotonic acid, cis-2-pentenoic acid, trans-2-pentenoic acid, angelic acid, tigric acid, 3,3-dimethylacrylic acid, 3-propylacrylic acid, trans-2-methyl-3-ethylacrylic acid, cis-2-methyl-3-ethylacrylic acid, 3-isopropylacrylic acid, 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, and 2-pentyl acrylate. Acrylic 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,The method according to [1], selected from the group consisting of 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, methyl maleic acid, dimethyl maleic acid, phenyl maleic acid, bromomaleic acid, chloromaleic acid, dichloromaleic acid, fluoromaleic acid, difluoromaleic acid, nonyl hydrogen maleate, decyl hydrogen maleate, dodecyl hydrogen maleate, octadecyl hydrogen maleate, fluoroalkyl hydrogen maleate, maleic anhydride, methyl maleic anhydride, dimethyl maleic anhydride, acrylic anhydride, methacrylic anhydride, metachlorein, methacryloyl chloride, methacryloyl fluoride, methacryloyl bromide, and combinations thereof. [8] The carboxylic acid base-containing monomers are acrylates, methacrylates, crotonates, 2-butylcrotonates, cinnamates, maleates, anhydrous maleates, fumarates, itaconates, anhydrous itaconates, tetraconates, 2-ethylacrylates, isocrotonates, cis-2-pentenoates, trans-2-pentenoates, angelicaates, tigrinates, 3,3-dimethylacrylates, 3-propylacrylates, trans-2-methyl-3-ethylacrylates, cis-2-methyl-3-ethyl Acrylate, 3-isopropyl acrylate, trans-3-methyl-3-ethyl acrylate, cis-3-methyl-3-ethyl acrylate, 2-isopropyl acrylate, trimethyl acrylate, 2-methyl-3,3-diethyl acrylate, 3-butyl acrylate, 2-butyl acrylate, 2-pentyl acrylate, 2-methyl-2-hexenoate, trans-3-methyl-2-hexenoate, 3-methyl-3-propyl acrylate, 2-ethyl-3-propyl acrylate, 2,3-diethyl acrylate Acrylate, 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 The method according to [1], selected from the group consisting of tyl-3-isopropylacrylate, trans-2-octenate, cis-2-octenate, trans-2-decenoate, α-acetoxyacrylate, β-trans-aryloxyacrylate, α-chloro-β-E-methoxyacrylate, methyl maleate, dimethyl maleate, phenyl maleate, bromomaleate, chloromaleate, dichloromaleate, fluoromaleate, difluoromaleate, and combinations thereof. [9] The method according to [1], wherein the sulfonic acid group-containing monomer is selected from the group consisting of vinyl sulfonic acid, methyl vinyl sulfonic acid, allyl vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonic acid, 2-sulfoethyl methacrylic acid, 2-methylpropa-2-ene-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 sulfonic acid base-containing monomer is selected from the group consisting of vinyl sulfonates, methyl vinyl sulfonates, allyl vinyl sulfonates, allyl sulfonates, methallyl sulfonates, styrene sulfonates, 2-sulfoethyl methacrylate, 2-methylpropa-2-ene-1-sulfonates, 2-acrylamido-2-methyl-1-propanesulfonates, 3-allyloxy-2-hydroxy-1-propanesulfonates, allyl sulfate salts, vinyl sulfate salts, and combinations thereof, according to the method described in [1].

[11] The method according to [1], wherein the phosphonic acid group-containing monomer is selected from the group consisting of vinylphosphonic acid, allylphosphonic acid, vinylbenzylphosphonic acid, acrylamide alkylphosphonic acid, methacrylamide alkylphosphonic acid, acrylamide alkyldiphosphonic acid, acryloylphosphonic 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 phosphonic acid base-containing monomer is selected from the group consisting of vinyl phosphonates, salts of allyl phosphonic acid, salts of vinyl benzyl phosphonic acid, salts of acrylamide alkyl phosphonic acid, salts of methacrylamide alkyl phosphonic acid, salts of acrylamide alkyl diphosphonic acid, salts of acryloyl phosphonic acid, salts of 2-methacryloyloxyethyl phosphonic acid, salts of bis(2-methacryloyloxyethyl) phosphonic acid, salts of ethylene 2-methacryloyloxyethyl phosphonic acid, salts of ethyl-methacryloyloxyethyl phosphonic acid, allyl phosphate salts, vinyl phosphate salts, and combinations thereof, according to the method according to [1].

[13] The method according to [1], wherein the copolymer further comprises a structural unit (b), the structural unit (b) is obtained from a monomer selected from the group consisting of amide group-containing monomers, hydroxyl group-containing monomers, and combinations thereof.

[14] The method according to

[13] , wherein the proportion of the structural unit (b) in the copolymer is about 5 mol% to about 35 mol% based on the total number of moles of monomer units in the copolymer binder.

[15] The amide group-containing monomers are acrylamide, methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, Nn-propylmethacrylamide, N-isopropylmethacrylamide, isopropylacrylamide, Nn-butylmethacrylamide, N-isobutylmethacrylamide, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N,N-diethylacrylamide, N,N-diethylmethacrylamide, N-methylolmethacrylamide, N-(methoxymethyl)methacrylamide, N-(ethoxymethyl)methacrylamide, N-(propoxymethyl)methacryl The method according to

[13] , selected from the group consisting of amides, N-(butoxymethyl)methacrylamide, N,N-dimethylmethacrylamide, N,N-dimethylaminopropylmethacrylamide, N,N-dimethylaminoethylmethacrylamide, N,N-dimethylolmethacrylamide, diacetone methacrylamide, diacetone acrylamide, methacryloylmorpholine, N-hydroxylmethacrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, N,N'-methylene-bis-acrylamide (MBA), N-hydroxymethylacrylamide, and combinations thereof.

[16] The method according to [1] or

[13] , wherein the copolymer further comprises a structural unit (c), the structural unit (c) being obtained from a monomer selected from the group consisting of nitrile group-containing monomers, ester group-containing monomers, epoxy group-containing monomers, fluorine-containing monomers, and combinations thereof.

[17] The method according to

[16] , wherein the proportion of the structural unit (c) in the copolymer is about 10 mol% to about 60 mol%, based on the total number of moles of monomer units in the copolymer binder.

[18] The nitrile group-containing monomer is selected from the group consisting of acrylonitrile, α-halogenoacrylonitrile, 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

[16] .

[19] The method according to [1], wherein the metal substrate is in the form of a foil, sheet, film, or a combination thereof, and 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.

[20] The method according to [1], wherein the metal substrate is in the form of a porous body having a three-dimensional network structure, and 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.

[21] The method according to [1], wherein the weight ratio of the composite material to the stripping solution is about 0.01% to about 50%, and the composite material is immersed in the stripping solution at a temperature of about 10°C to about 90°C.

Claims

1. A method for removing a composite material by immersing it in a stripping solution; The aforementioned stripping solution comprises a stripping agent and an aqueous solvent, wherein the stripping agent is a water-soluble strong base; The composite material comprises a metal substrate and a coating applied to one or both sides of the metal substrate, wherein the coating comprises a copolymer binder; The copolymer binder is Structural units (a) obtained from monomers selected from the group consisting of carboxylic acid group-containing monomers, sulfonic acid group-containing monomers, phosphonic acid group-containing monomers, carboxylic acid base-containing monomers, sulfonic acid base-containing monomers, phosphonic acid base-containing monomers, and combinations thereof, Structural units (b) obtained from monomers selected from the group consisting of amide group-containing monomers, hydroxyl group-containing monomers, and combinations thereof, and Structural units (c) obtained from monomers selected from the group consisting of nitrile group-containing monomers, ester group-containing monomers, epoxy group-containing monomers, fluorine-containing monomers, and combinations thereof, Including; The proportion of the structural unit (a) in the copolymer binder is approximately 30 mol% to approximately 80 mol%, based on the total number of moles of monomer units in the copolymer binder. The proportion of the structural unit (b) in the copolymer binder is approximately 5 mol% to approximately 35 mol%, based on the total number of moles of monomer units in the copolymer binder. The proportion of the structural unit (c) in the copolymer binder is approximately 10 mol% to approximately 60 mol%, based on the total number of moles of monomer units in the copolymer binder. The aforementioned method.

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

3. The method according to claim 1, wherein the stripping agent is selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, lithium oxide, sodium oxide, potassium oxide, rubidium oxide, cesium oxide, calcium oxide, strontium oxide, barium oxide, and combinations thereof.

4. The method according to claim 1, wherein the aqueous solvent is water.

5. The aqueous solvent contains water as the main component and trace components, and the proportion of water in the aqueous solvent is greater than 51% by weight and less than 100% by weight. The method according to claim 1, wherein the trace component is selected from the group consisting of methanol, ethanol, isopropanol, n-propanol, tert-butanol, n-butanol, acetone, dimethyl ketone, methyl ethyl ketone, ethyl acetate, isopropyl acetate, propyl acetate, butyl acetate, and combinations thereof.

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

7. The carboxylic acid group-containing monomers include acrylic acid, methacrylic acid, crotonic acid, 2-butylcrotonic acid, cinnamic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, tetraconic 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, 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, and 2-pentyl acrylate. Acrylic 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, methyl maleic acid, dimethyl maleic acid, phenyl maleic acid, bromomaleic acid, chloromaleic acid, dichloromaleic acid, flu The method according to claim 1, selected from the group consisting of malomaleic acid, difluoromaleic acid, nonyl hydrogen maleate, decyl hydrogen maleate, dodecyl hydrogen maleate, octadecyl hydrogen maleate, fluoroalkyl hydrogen maleate, maleic anhydride, methyl maleic anhydride, dimethyl maleic anhydride, acrylic anhydride, methacrylic anhydride, methacrolein, methacryloyl chloride, methacryloyl fluoride, methacryloyl bromide, and combinations thereof.

8. The aforementioned carboxylic acid base-containing monomers are acrylates, methacrylates, crotonates, 2-butylcrotonates, cinnamates, maleates, maleic anhydrides, fumarates, itaconates, itaconates, tetraconates, 2-ethylacrylates, isocrotonates, cis-2-pentenoates, trans-2-pentenoates, angelicaates, tigphosphates, 3,3-dimethylacrylates, 3-propylacrylates, trans-2-methyl-3-ethylacrylates, cis-2-methyl-3-ethyl Acrylate, 3-isopropyl acrylate, trans-3-methyl-3-ethyl acrylate, cis-3-methyl-3-ethyl acrylate, 2-isopropyl acrylate, trimethyl acrylate, 2-methyl-3,3-diethyl acrylate, 3-butyl acrylate, 2-butyl acrylate, 2-pentyl acrylate, 2-methyl-2-hexenoate, trans-3-methyl-2-hexenoate, 3-methyl-3-propyl acrylate, 2-ethyl-3-propyl acrylate, 2,3-diethyl acrylate Acrylate, 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 The method according to claim 1, selected from the group consisting of tyl-3-isopropylacrylate, trans-2-octenate, cis-2-octenate, trans-2-decenoate, α-acetoxyacrylate, β-trans-aryloxyacrylate, α-chloro-β-E-methoxyacrylate, methyl maleate, dimethyl maleate, phenyl maleate, bromo maleate, chloro maleate, dichloro maleate, fluoro maleate, difluoro maleate, 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, methyl vinyl sulfonic acid, allyl vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonic acid, 2-sulfoethyl methacrylic acid, 2-methylpropa-2-ene-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 according to claim 1, wherein the sulfonic acid base-containing monomer is selected from the group consisting of vinyl sulfonate, methyl vinyl sulfonate, allyl vinyl sulfonate, allyl sulfonate, methallyl sulfonate, styrene sulfonate, 2-sulfoethyl methacrylate, 2-methylpropa-2-ene-1-sulfonate, 2-acrylamido-2-methyl-1-propane sulfonate, 3-allyloxy-2-hydroxy-1-propane sulfonate, allyl sulfate salt, vinyl sulfate salt, and combinations thereof.

11. The method according to claim 1, wherein the phosphonic acid group-containing monomer is selected from the group consisting of vinylphosphonic acid, allylphosphonic acid, vinylbenzylphosphonic acid, acrylamide alkylphosphonic acid, methacrylamide alkylphosphonic acid, acrylamide alkyldiphosphonic acid, acryloylphosphonic 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 according to claim 1, wherein the phosphonic acid base-containing monomer is selected from the group consisting of vinyl phosphonates, salts of allyl phosphonic acid, salts of vinyl benzyl phosphonic acid, salts of acrylamide alkyl phosphonic acid, salts of methacrylamide alkyl phosphonic acid, salts of acrylamide alkyl diphosphonic acid, salts of acryloyl phosphonic acid, salts of 2-methacryloyloxyethyl phosphonic acid, salts of bis(2-methacryloyloxyethyl) phosphonic acid, salts of ethylene 2-methacryloyloxyethyl phosphonic acid, salts of ethyl-methacryloyloxyethyl phosphonic acid, allyl phosphate salts, vinyl phosphate salts, and combinations thereof.

13. The method according to claim 1, wherein the proportion of the structural unit (b) in the copolymer binder is greater than 7.5 mol% and less than or equal to about 30 mol%, based on the total number of moles of monomer units in the copolymer binder.

14. The amide group-containing monomers are 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-methylolmethacrylamide, N-(methoxymethyl)methacrylamide, N-(ethoxymethyl)methacrylamide, N-(propoxymethyl) The method according to claim 1, selected from the group consisting of methyl(N-)methacrylamide, N-(butoxymethyl)methacrylamide, N,N-dimethylaminopropylmethacrylamide, N,N-dimethylaminoethylmethacrylamide, N,N-dimethylolmethacrylamide, diacetone methacrylamide, diacetone acrylamide, methacryloylmorpholine, N-hydroxylmethacrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, N,N'-methylene-bis-acrylamide (MBA), N-hydroxymethylacrylamide, and combinations thereof.

15. The method according to claim 1, wherein the proportion of the structural unit (c) in the copolymer binder is greater than 12.5 mol% and less than or equal to about 60 mol%, based on the total number of moles of monomer units in the copolymer binder.

16. The method according to claim 1, wherein the nitrile group-containing monomer is selected from the group consisting of acrylonitrile, α-halogenoacrylonitrile, 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.

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

18. The method according to claim 1, wherein the metal substrate is in the form of a porous body having a three-dimensional network structure, and 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.

19. The method according to claim 1, wherein the weight ratio of the composite material to the stripping solution is about 0.01% to about 50%, and the composite material is immersed in the stripping solution at a temperature of about 10°C to about 90°C.

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