Carbon coating layer composition for debonding carbon-coated aluminum foil and preparation method thereof, debonding carbon-coated aluminum foil and debonding method thereof

Abstract

The present invention discloses a carbon coating composition for debonding carbon-coated aluminum foil, a preparation method thereof, and a debonding carbon-coated aluminum foil and a debonding method thereof, and relates to the field of carbon-coated aluminum foil. The carbon coating composition for debonding carbon-coated aluminum foil comprises a basic carbon coating raw material, a low-temperature thermal curing agent, and a debonding aid. The debonding aid comprises a high-temperature thermal curing agent. The curing reaction temperature of the low-temperature thermal curing agent is less than 130°C, and the curing starting reaction temperature of the high-temperature thermal curing agent is greater than the curing reaction temperature of the low-temperature curing agent. In the present application, the low-temperature thermal curing agent is used to initiate primary curing, and the high-temperature thermal curing agent is used to initiate secondary curing. However, the initiation of primary curing is immediately followed by the application of the carbon coating composition, so as to promote the firm adhesion of the carbon coating layer on the surface of the aluminum foil substrate. The initiation of secondary curing is when the performance of the battery deteriorates after repeated use and the positive electrode active material needs to be recovered. The function of the secondary curing is to embrittle the carbon coating layer between the aluminum foil substrate and the positive electrode active material, so as to achieve the whole-piece peeling of the positive electrode active material.

Description

Technical Field

[0001] The present application relates to the technical field of carbon-coated aluminum foil for lithium-ion batteries, and in particular to a carbon-coated layer composition for debonding carbon-coated aluminum foil and a preparation method thereof, and a debonding carbon-coated aluminum foil and a debonding method thereof. Background Art

[0002] Carbon-coated aluminum foil is now widely used in power and energy storage batteries, as well as some consumer batteries. However, no matter how much effort is put into improving performance and extending battery life, there comes a time when it needs to be recycled and reused. The current mainstream recycling method involves discharging, pulverizing, and chemically reducing the elements to compounds such as lithium carbonate, nitrates, and sulfates, followed by repolymerization. This process requires multiple chemical extraction and purification steps, which also imposes an intangible burden on the environment. Therefore, developing a simple and low-cost method for recycling positive electrode active materials is of great research significance. Summary of the Invention

[0003] This application uses the decomposition and degradation of the battery carbon coating to debond the positive electrode active material from the aluminum foil substrate. The positive electrode active material can be removed from the entire surface, reducing the recycling process and saving labor and time costs.

[0004] First, the carbon-coated layer composition for debonding carbon-coated aluminum foil provided in this application adopts the following technical solution:

[0005] A carbon coating composition for debonding carbon-coated aluminum foil comprises a basic carbon coating raw material, a low-temperature thermal curing agent and a debonding aid, wherein the debonding aid comprises a high-temperature thermal curing agent, the curing reaction temperature of the low-temperature thermal curing agent is less than 130° C., and the curing reaction temperature of the high-temperature thermal curing agent is greater than the curing reaction temperature of the low-temperature curing agent.

[0006] The carbon-coating composition for debonding carbon-coated aluminum foil of this application utilizes both a low-temperature thermal curing agent and a high-temperature thermal curing agent based on a base carbon-coating raw material. The high-temperature thermal curing agent has a higher curing reaction temperature than the low-temperature curing agent, utilizing the difference in curing reaction temperatures to achieve different functions. The low-temperature thermal curing agent promotes a primary curing of the carbon-coating composition applied to the aluminum foil substrate, ensuring strong adhesion of the carbon-coating layer to the aluminum foil substrate. During this process, it is important to ensure that the primary curing reaction temperature is lower than the curing reaction temperature of the high-temperature thermal curing agent to prevent the carbon-coating layer from becoming brittle, which could affect the battery's normal operation. The high-temperature thermal curing agent promotes a secondary curing of the carbon-coating layer when battery performance degrades and the positive electrode active material needs to be recovered. The secondary curing temperature must be greater than or equal to the curing reaction temperature of the high-temperature thermal curing agent. At this point, the high-temperature thermal curing agent initiates the secondary curing, brittle the carbon-coating layer between the aluminum foil substrate and the positive electrode active material, facilitating separation between the aluminum foil substrate and the positive electrode active material, and facilitating the recovery of a single sheet of positive electrode active material. This eliminates the need for reduction and polymerization steps, significantly simplifying the recycling process and reducing recycling costs.

[0007] Preferably, the curing starting reaction temperature of the high-temperature thermal curing agent is greater than 150°C.

[0008] In the present application, the curing starting reaction temperature of the high-temperature thermal curing agent is preferably greater than 150°C. By increasing the difference between the curing reaction temperatures of the high-temperature thermal curing agent and the low-temperature thermal curing agent, it is beneficial to prevent the problem of partial reaction of the high-temperature thermal curing agent during a single curing reaction, and can further enhance the bonding strength between the carbon coating layer and the aluminum foil substrate, which is beneficial to extending the service life of the battery.

[0009] More preferably, the debonding aid further comprises a lithium compound, and the lithium compound is a strong alkaline lithium compound or a strong base weak acid salt of lithium.

[0010] In the present application, the debonding aid also includes a lithium compound. The lithium compound uses a strong alkaline compound of lithium or a strong base weak acid salt of lithium, which can catalyze the high-temperature thermal curing agent to carry out a secondary curing reaction, which is beneficial to improving the reaction efficiency of the secondary curing and shortening the reaction time of the secondary curing.

[0011] In some specific embodiments, the basic carbon-coated raw material includes a conductive agent, a binder, a dispersant and an adhesion promoter; in the carbon-coated layer composition for debonding carbon-coated aluminum foil, the weight proportion of the conductive agent is 40~80%, the weight proportion of the binder is 15~50%, the weight proportion of the dispersant is 2~5%, the weight proportion of the adhesion promoter is 0.1~2%, the weight proportion of the low-temperature thermal curing agent is 2~5%, and the weight proportion of the debonding aid is 0.1~2%.

[0012] In some preferred embodiments, the conductive agent is a combination of any two or three of graphite, conductive carbon, and carbon nanotubes, wherein the D50 particle size of the graphite is in the range of 2 to 20 μm, the particle size of the conductive carbon is in the range of 20 to 50 nm, and the carbon nanotubes are multi-walled carbon nanotubes.

[0013] In the present application, the particle size range of graphite and conductive carbon is limited, which is beneficial to the uniform dispersion of the two in the carbon coating composition and to the improvement of the surface smoothness of the carbon coating. Carbon nanotubes preferably use multi-walled carbon nanotubes with higher conductivity. Among them, the conductive agent is preferably a combination of any two or three of graphite, conductive carbon, and carbon nanotubes, which can better construct a conductive network and improve the rate performance of the lithium battery.

[0014] In some preferred embodiments, the adhesive is any one of polyacrylic acid and polyethylene acrylic acid, wherein the glass transition temperature of the polyacrylic acid is 100-150°C, and the glass transition temperature of the polyethylene acrylic acid is 120-180°C.

[0015] In this application, the binder uses polyacrylic acid or polyethylene acrylic acid with a specific glass transition temperature, which is conducive to forming a carbon coating layer with a denser cross-linked network, improving the bonding strength between the carbon coating layer and the aluminum foil substrate, and at the same time, improving the heat resistance of the carbon coating layer.

[0016] In some specific embodiments, the adhesion promoter is at least one of a silane coupling agent, a tetrafunctional adhesion promoter, and a polyether-modified acrylate.

[0017] In some specific embodiments, the dispersant is polyacrylic acid or carboxymethyl cellulose.

[0018] The present application provides a method for preparing a carbon-coated layer composition for debonding carbon-coated aluminum foil using the following technical solution:

[0019] A method for preparing a carbon-coated layer composition for debonding carbon-coated aluminum foil comprises the following steps:

[0020] S1. After uniformly mixing the conductive agent and the diluted dispersant by high-speed shearing, the pH is adjusted to 6.5-7.5 to obtain a carbon source; wherein the dispersant is diluted with water;

[0021] S2. Adjust the pH of the binder to 6.5-7.5, then add the carbon source and stir evenly to obtain a masterbatch;

[0022] S3. Add the diluted adhesion promoter to the masterbatch and stir evenly to obtain a premix; in this step, the adhesion promoter is diluted with an ether alcohol diluent;

[0023] S4, controlling the temperature of the premix at 10-35° C., then adding a debonding aid, and stirring evenly to obtain a debonding carbon-coated aluminum foil carbon-coated layer composition;

[0024] Regarding the addition of a low-temperature thermal curing agent, when the curing reaction temperature of the low-temperature thermal curing agent is lower than 60°C, it can be added to the carbon coating composition and stirred evenly before coating; when the curing reaction temperature of the low-temperature thermal curing agent is above 60°C, it can be diluted with an alcohol ether diluent and directly mixed in step S3 or S4.

[0025] The following points should be noted during the preparation of the carbon-coated layer composition for debonding carbon-coated aluminum foil: when the low-temperature thermal curing agent is not added before use, the adhesion promoter and the low-temperature thermal curing agent should be diluted before addition to prevent the problem of premature reaction due to excessive local concentration, which affects storage stability; alternatively, the pH value of the binder with reactive functional groups should be adjusted to 6.5-7.5 to prevent premature reaction during storage.

[0026] The present application provides a debonding carbon-coated aluminum foil, which includes an aluminum foil substrate layer and a carbon coating layer coated on the surface of the aluminum foil substrate layer. The carbon coating layer is obtained by coating and once curing a carbon coating layer composition for debonding carbon-coated aluminum foil as described in any one of the above items, and the temperature of the once curing is less than 130°C.

[0027] The temperature of the primary curing is controlled below 130°C, which can not only ensure the stable adhesion between the carbon coating layer and the aluminum foil substrate, but also prevent the high-temperature thermal curing agent in the carbon coating layer from being activated to produce secondary curing, which is beneficial to the normal use of the battery.

[0028] The present application provides a debonding method for a debonding carbon-coated aluminum foil, which specifically includes the following steps: heating the debonding carbon-coated aluminum foil to a debonding temperature for secondary curing, wherein the debonding temperature is equal to or greater than the curing reaction temperature of the high-temperature thermal curing agent, so that the structure of the carbon coating layer becomes brittle.

[0029] When the battery performance deteriorates and the positive electrode active material needs to be recovered, the debonded carbon-coated aluminum foil is directly heated to the debonding temperature. The debonding temperature is equal to or greater than the curing reaction temperature of the high-temperature thermal curing agent, which can activate the high-temperature thermal curing agent and promote the secondary curing of the carbon coating layer. The structure of the carbon coating layer becomes hard and brittle due to the secondary curing, which facilitates the peeling between the aluminum foil substrate and the positive electrode active material, and is conducive to obtaining a whole piece of positive electrode active material without the need for reduction and polymerization steps, which greatly simplifies the recycling process and saves recycling costs.

[0030] The present application provides an application of a debonding carbon-coated aluminum foil, which is specifically applied to the production of lithium-ion batteries.

[0031] In summary, this application has at least the following beneficial technical effects:

[0032] (1) The carbon coating composition of the present application uses both a low-temperature thermal curing agent and a high-temperature thermal curing agent. The low-temperature thermal curing agent is used to initiate primary curing, and the high-temperature thermal curing agent is used to initiate secondary curing. However, the initiation of primary curing is immediately after the application of the carbon coating composition, which promotes the strong adhesion of the carbon coating layer to the surface of the aluminum foil substrate. The initiation of secondary curing is when the performance of the battery deteriorates after repeated use and the positive electrode active material needs to be recovered. The purpose is to embrittle the carbon coating layer between the aluminum foil substrate and the positive electrode active material, thereby facilitating the peeling between the aluminum foil substrate and the positive electrode active material, which is beneficial to obtaining a whole piece of positive electrode active material without the need for reduction and polymerization steps, greatly simplifying the recycling process and saving recycling costs.

[0033] (2) In the present application, the debonding aid also includes a lithium compound. The lithium compound adopts a strong alkaline compound of lithium or a strong base weak acid salt of lithium, which can catalyze the high-temperature thermal curing agent to carry out a secondary curing reaction, which is beneficial to improving the reaction efficiency of the secondary curing and shortening the reaction time of the secondary curing. DETAILED DESCRIPTION

[0034] The present application is further described below in conjunction with specific experiments.

[0035] First, the present application discloses a debonding carbon-coated aluminum foil, comprising an aluminum foil substrate layer and a carbon coating layer coated on the surface of the aluminum foil substrate layer, wherein the carbon coating layer is obtained by coating and once curing a carbon coating layer composition for debonding carbon-coated aluminum foil.

[0036] Specifically, the carbon coating layer composition includes a conductive agent, a binder, a dispersant, an adhesion promoter, a low-temperature thermal curing agent and a debonding agent. The weight proportion of the conductive agent is 40~80%, the weight proportion of the binder is 15~50%, the weight proportion of the dispersant is 2~5%, the weight proportion of the adhesion promoter is 0.1~2%, the weight proportion of the low-temperature thermal curing agent is 2~5%, and the weight proportion of the debonding agent is 0.1~2%.

[0037] The conductive agent is a combination of any two or three of graphite, conductive carbon, and carbon nanotubes. The graphite has a D50 particle size range of 2-20 μm, the conductive carbon has a particle size range of 20-50 nm, and the carbon nanotubes are multi-walled carbon nanotubes. Preferably, the graphite undergoes a pretreatment step, which includes exfoliating the graphite using a sand mill at a speed of 400-800 rpm until the viscosity stabilizes at 800-2500 cps, which facilitates uniform dispersion of the graphite. Further preferably, the conductive agent is a combination of graphite, conductive carbon, and multi-walled carbon nanotubes, with the weight ratio of graphite, conductive carbon, and multi-walled carbon nanotubes being (1-3):(1-2):1.

[0038] The adhesive is any one of polyacrylic acid and polyethylene acrylic acid. Preferably, the glass transition temperature of polyacrylic acid is 100-150°C, and preferably the glass transition temperature of polyethylene acrylic acid is 120-180°C.

[0039] The dispersant is used to improve the dispersion effect of the conductive agent in the binder. The dispersant can be a polyacrylic acid dispersant or carboxymethyl cellulose.

[0040] The adhesion promoter is used to further improve the adhesion strength between the carbon coating layer and the aluminum foil substrate, wherein the adhesion promoter is at least one of a silane coupling agent, a tetrafunctional adhesion promoter, and a polyether-modified acrylate.

[0041] The low-temperature thermal curing agent is used for the primary curing of the carbon coating composition to achieve firm adhesion of the carbon coating layer to the surface of the aluminum foil substrate. In this application, the low-temperature thermal curing agent is an amino resin, dicyandiamide, or hydrazide, as long as the curing reaction temperature is lower than 130°C.

[0042] The debonding aid includes a high-temperature thermal curing agent, the curing reaction temperature of which is higher than that of the low-temperature thermal curing agent. In the present application, the high-temperature thermal curing agent is preferably a dicyandiamide-based high-temperature thermal curing agent having a curing reaction temperature greater than 150°C. By increasing the difference in curing reaction temperature between the high-temperature thermal curing agent and the low-temperature thermal curing agent, it is helpful to prevent the problem of partial reaction of the high-temperature thermal curing agent during the primary curing reaction, and further improve the adhesion between the carbon coating layer and the aluminum foil substrate.

[0043] Preferably, the debonding aid may further include a lithium compound, which is used to catalyze secondary curing of the adhesive under the action of a high-temperature thermal curing agent. The lithium compound is a strong alkaline lithium compound or a strong base weak acid salt of lithium.

[0044] That is, the carbon coating layer composition of the present application uses both a low-temperature thermal curing agent and a high-temperature thermal curing agent. The low-temperature thermal curing agent is used to initiate primary curing, and the high-temperature thermal curing agent is used to initiate secondary curing. However, the primary curing is initiated immediately after the carbon coating layer composition is applied, and the secondary curing is initiated when the battery performance deteriorates after repeated use and the positive electrode active material needs to be recovered.

[0045] The present application discloses a method for preparing a debonding carbon-coated aluminum foil, comprising the following steps:

[0046] (1) Preparation of carbon coating composition for debonding carbon-coated aluminum foil:

[0047] S1. After uniformly mixing the conductive agent and the diluted dispersant by high-speed shearing, the pH is adjusted to 6.5-7.5 to obtain a carbon source; wherein the dispersant is diluted with water, and the weight ratio of the dispersant to water is 1: (4-9);

[0048] S2. Adjust the pH of the binder to 6.5-7.5, then add the carbon source and stir evenly to obtain a masterbatch;

[0049] S3. Add the diluted adhesion promoter to the masterbatch and stir evenly to obtain a premix; in this step, the adhesion promoter is diluted with an ether alcohol diluent;

[0050] S4. Control the temperature of the premix at 10-35° C., then add a debonding aid, and stir evenly to obtain a debonding carbon-coated aluminum foil carbon-coated layer composition;

[0051] Regarding the addition of a low-temperature thermal curing agent, when the curing reaction temperature of the low-temperature thermal curing agent is lower than 60°C, it can be added to the carbon coating composition and stirred evenly before coating; when the curing reaction temperature of the low-temperature thermal curing agent is above 60°C, it can be diluted with an alcohol ether diluent and directly mixed in step S3 or S4.

[0052] Coating and primary curing: coating the carbon coating layer composition for the debonding carbon-coated aluminum foil on the aluminum foil substrate by gravure coating, controlling the oven temperature not to exceed 130° C. for primary curing to obtain the debonding carbon-coated aluminum foil.

[0053] Preferably, in S1, the graphite is exfoliated using a sand mill at 400 rpm until its D50 is 2-20 μm and its viscosity is 800-2500 cps, thereby obtaining slurry A. The conductive carbon and carbon nanotubes are added to a water-diluted dispersant at a weight ratio of 1:4-9. The pH is adjusted to 6.5-7.5, and the mixture is stirred to obtain slurry B. Slurries A and B are then added to a sand mill and mixed at high shear strength until the viscosity reaches 20-200 cps, thereby obtaining a carbon source. This step of preparing the carbon source facilitates uniform dispersion of the conductive agent.

[0054] Preferably, the weight ratio of the adhesion promoter to the alcohol ether diluent is 1:(4-10), and the weight ratio of the low-temperature thermal curing agent to propylene glycol methyl ether is 1:(8-15).

[0055] The present application discloses a debonding method for debonding carbon-coated aluminum foil, comprising the following steps: heating the debonding carbon-coated aluminum foil to a debonding temperature for secondary curing, wherein the debonding temperature is equal to or greater than the curing starting reaction temperature of a high-temperature thermal curing agent, so that the structure of the carbon coating layer becomes brittle.

[0056] The present application is further described below in conjunction with specific experiments. Example

[0057] [Example 1]

[0058] A debonding carbon-coated aluminum foil comprises an aluminum foil substrate layer and a carbon coating layer applied to the surface of the aluminum foil substrate layer. The carbon coating layer is obtained by coating and curing a carbon coating composition for debonding carbon-coated aluminum foil. In this embodiment, the carbon coating composition for debonding carbon-coated aluminum foil is prepared from 40 wt% of a conductive agent, 50% of a binder, 2 wt% of a dispersant, 1.1 wt% of an adhesion promoter, 5 wt% of a low-temperature thermal curing agent, and 1.9 wt% of a debonding aid. The conductive agent comprises graphite, acetylene black, and multi-walled carbon nanotubes, with the weight ratio of graphite, acetylene black, and multi-walled carbon nanotubes being 2:1:1. The binder is polyacrylic acid with a glass transition temperature of 120-125°C, the dispersant is a polyacrylic acid dispersant, the adhesion promoter is aminosilane coupling agent KH550, the low-temperature thermal curing agent is benzoylhydrazide, and the debonding aid is dicyandiamide-based high-temperature thermal curing agent DICY.

[0059] The present embodiment provides a method for preparing a debonding carbon-coated aluminum foil, comprising the following steps:

[0060] (1) Preparation of carbon coating composition for debonding carbon-coated aluminum foil:

[0061] S1. Exfoliate the graphite using a sand mill at 400 rpm until D50 = 8 μm and the viscosity is 1700-2500 cps to obtain slurry A. Add acetylene black and multi-walled carbon nanotubes to a polyacrylic acid dispersant diluted with water (the ratio of dispersant to water is 1:6), adjust the pH to 6.5-7.5, and stir to obtain slurry B. Then, add slurry A and slurry B to a sand mill and mix at high shear until the viscosity reaches 100-120 cps to obtain a carbon source.

[0062] S2. Adjust the pH of the binder polyacrylic acid to 6.5-7.5, then add a carbon source and stir evenly to obtain a masterbatch;

[0063] S3. Add the diluted aminosilane coupling agent KH550 and benzohydrazide to the masterbatch and stir to obtain a premix; in this step, the aminosilane coupling agent KH550 and benzohydrazide are both diluted with propylene glycol methyl ether, the weight ratio of the aminosilane coupling agent KH550 to the propylene glycol methyl ether is 1:8, and the weight ratio of the benzohydrazide to the propylene glycol methyl ether is 1:10;

[0064] S4, controlling the temperature of the premix at 25° C., then adding a dicyandiamide-based high-temperature thermal curing agent DICY, and stirring evenly to obtain a carbon-coated layer composition for debonding carbon-coated aluminum foil;

[0065] (2) Coating and primary curing: The carbon coating layer composition for the debonding carbon-coated aluminum foil is coated on the aluminum foil substrate by gravure coating, and the oven temperature is controlled to be 125°C for primary curing, and the curing time is 60 seconds to obtain the debonding carbon-coated aluminum foil.

[0066] [Example 2]

[0067] A debonding carbon-coated aluminum foil is different from Example 1 in that the weight proportions of the components of the carbon-coated layer composition used in the debonding carbon-coated aluminum foil are different.

[0068] In this embodiment, the carbon coating composition for debonding carbon-coated aluminum foil is prepared from 75 wt % of a conductive agent, 15 wt % of a binder, 5 wt % of a dispersant, 0.1 wt % of an adhesion promoter, 3 wt % of a low-temperature thermal curing agent, and 1.9 wt % of a debonding aid.

[0069] Performance testing

[0070] The peel strength test was performed on the debonding carbon-coated aluminum foils prepared in Examples 1 and 2. Then, the debonding carbon-coated aluminum foils prepared in Examples 1 and 2 were heated to 200° C. for secondary curing for 60 seconds. After cooling, the peel strength between the carbon coating layer in the debonding carbon-coated aluminum foil and the aluminum foil substrate was tested again.

[0071] Table 1

[0072]

[0073] Combining the above-described examples 1 and 2, it can be seen that before debonding, the peel strength between the carbon-coated layer and the aluminum foil substrate in the debonded carbon-coated aluminum foil was greater than 3 N / cm. After debonding, the peel strength between the carbon-coated layer and the aluminum foil substrate was less than 1 N / cm. After debonding, the debonded carbon-coated aluminum foil becomes brittle, significantly reducing the peel strength between the carbon-coated layer and the aluminum foil substrate. This facilitates the peeling of the carbon-coated layer from the aluminum foil substrate and the positive electrode active material, thereby enabling the recovery of the positive electrode active material in its entirety.

[0074] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A method for debonding carbon-coated aluminum foil, characterized by: The debonding carbon-coated aluminum foil comprises an aluminum foil substrate layer and a carbon coating layer coated on the surface of the aluminum foil substrate layer. The carbon coating layer is obtained by coating and once-curing a carbon coating layer composition for debonding carbon-coated aluminum foil. The temperature of the once-curing is less than 130° C. The carbon coating layer composition for debonding carbon-coated aluminum foil comprises a basic carbon coating raw material, a low-temperature thermal curing agent, and a debonding aid. The debonding aid comprises a high-temperature thermal curing agent. The curing reaction temperature of the high-temperature thermal curing agent is greater than 150° C., the curing reaction temperature of the low-temperature thermal curing agent is less than 130° C., and the curing reaction temperature of the high-temperature thermal curing agent is greater than the curing reaction temperature of the low-temperature thermal curing agent. The debonding method of the debonding carbon-coated aluminum foil comprises the following steps: heating the debonding carbon-coated aluminum foil to a debonding temperature for secondary curing, wherein the debonding temperature is equal to or greater than the curing reaction temperature of the high-temperature thermal curing agent, so as to cause embrittlement of the structure of the carbon coating layer.

2. The method for debonding carbon-coated aluminum foil according to claim 1, characterized in that: The debonding aid further comprises a lithium compound, wherein the lithium compound is a strong alkaline lithium compound or a strong base weak acid salt of lithium.

3. The method for debonding carbon-coated aluminum foil according to claim 1, characterized in that: The basic carbon-coated raw material includes a conductive agent, a binder, a dispersant and an adhesion promoter; in the carbon-coated layer composition for debonding carbon-coated aluminum foil, the weight proportion of the conductive agent is 40-80%, the weight proportion of the binder is 15-50%, the weight proportion of the dispersant is 2-5%, the weight proportion of the adhesion promoter is 0.1-2%, the weight proportion of the low-temperature thermal curing agent is 2-5%, and the weight proportion of the debonding aid is 0.1-2%.

4. The method for debonding carbon-coated aluminum foil according to claim 3, characterized in that: The conductive agent is a combination of any two or three of graphite, conductive carbon, and carbon nanotubes, wherein the D50 particle size of the graphite is in the range of 2-20 μm, the particle size of the conductive carbon is in the range of 20-50 nm, and the carbon nanotubes are multi-walled carbon nanotubes.

5. The method for debonding carbon-coated aluminum foil according to claim 3, characterized in that: The adhesive is any one of polyacrylic acid and polyethylene acrylic acid, wherein the glass transition temperature of the polyacrylic acid is 100-150°C, and the glass transition temperature of the polyethylene acrylic acid is 120-180°C.

6. The method for debonding carbon-coated aluminum foil according to claim 3, characterized in that: The adhesion promoter is at least one of a silane coupling agent and a polyether-modified acrylate.

7. The debonding method of carbon-coated aluminum foil according to claim 3, characterized in that: The method for preparing the carbon-coated layer composition for debonding carbon-coated aluminum foil comprises the following steps: S1. After uniformly mixing the conductive agent and the diluted dispersant by high-speed shearing, the pH is adjusted to 6.5-7.5 to obtain a carbon source; wherein the dispersant is diluted with water; S2. Adjust the pH of the binder to 6.5-7.5, then add the carbon source and stir evenly to obtain a masterbatch; S3. Add the diluted adhesion promoter to the masterbatch and stir evenly to obtain a premix; in this step, the adhesion promoter is diluted with an ether alcohol diluent; S4, controlling the temperature of the premix at 10-35° C., then adding a debonding aid, and stirring evenly to obtain a debonding carbon-coated aluminum foil carbon-coated layer composition; Regarding the addition of a low-temperature thermal curing agent, when the curing reaction temperature of the low-temperature thermal curing agent is lower than 60°C, it is added to the carbon coating composition and stirred evenly before coating; when the curing reaction temperature of the low-temperature thermal curing agent is above 60°C, it is diluted with an alcohol ether diluent and directly mixed in step S3 or S4.

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