A high-wettability conductive paint for carbon-coated aluminum foil and a method for preparing the same

Abstract

This invention relates to the field of conductive coating technology and discloses a highly wettable conductive coating for carbon-coated aluminum foil. The conductive coating for carbon-coated aluminum foil of this invention comprises the following raw materials in parts by weight: 5-10 parts conductive graphite, 20-30 parts carbon nanotubes, 15-20 parts graphene, 20-30 parts polyacrylic acid, 10-15 parts carboxylated nanocellulose, 5-10 parts chitosan-based modifier, 150-250 parts deionized water, and 50-100 parts isopropanol; wherein the conductive fillers are conductive graphite, carbon nanotubes, and graphene; and the binders are polyacrylic acid and carboxylated nanocellulose. This conductive coating not only possesses excellent conductivity but also high adhesion and high wettability, thus showing great promise for application in carbon-coated aluminum foil.

Description

Technical Field

[0001] This invention relates to the field of conductive coating technology, specifically to a highly wettable conductive coating for carbon-coated aluminum foil and its preparation method. Background Technology

[0002] Lithium-ion batteries typically use aluminum foil as the current collector in their positive electrode. However, the interfacial contact resistance between the aluminum foil surface and the positive electrode active material is relatively high, and the corrosion of the aluminum foil by the electrolyte can affect the battery's cycle performance. To address these issues, existing technologies coat the aluminum foil surface with a conductive coating, forming carbon-coated aluminum foil. This conductive coating usually contains conductive fillers (such as carbon black, conductive graphite, carbon nanotubes, graphene, etc.) and binders. After being coated onto the aluminum foil surface, it can effectively reduce the interfacial contact resistance, improve the electron conduction efficiency between the current collector and the positive electrode material, and buffer the corrosion of the aluminum foil by the electrolyte. Currently, conductive coatings for carbon-coated aluminum foil are mainly divided into two categories: oil-based systems and water-based systems. Among them, water-based systems have received widespread attention due to their advantages such as environmental friendliness and low cost.

[0003] However, water-based conductive coatings face two major technical challenges in practical applications: first, the high surface tension of water-based coatings makes it difficult to spread fully on aluminum foil with relatively low surface energy, leading to poor wetting defects such as pinholes, orange peel, and edge shrinkage during coating; second, conductive fillers tend to agglomerate in water-based systems, exhibiting poor dispersion stability, which affects the conductivity uniformity and adhesion of the coating. Therefore, developing a water-based conductive coating that combines high wetting and good dispersion stability is of great significance for improving the performance and yield of carbon-coated aluminum foil. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a highly wettable conductive coating for carbon-coated aluminum foil and its preparation method.

[0005] The objective of this invention can be achieved through the following technical solutions: A highly wettable conductive coating for carbon-coated aluminum foil comprises the following raw materials in parts by weight: 5-10 parts conductive graphite, 20-30 parts carbon nanotubes, 15-20 parts graphene, 20-30 parts polyacrylic acid, 10-15 parts carboxylated nanocellulose, 5-10 parts chitosan-based modifier, 150-250 parts deionized water, and 50-100 parts isopropanol. The chitosan-based modifier is prepared by the following steps: Step A1: Add 1H-imidazol-5-propanol and anhydrous methanol to the reactor and stir and mix evenly under nitrogen conditions at room temperature. Add acrylate while stirring, then heat to 35℃ and react for 4-6 hours. Remove the solvent and excess acrylate by rotary evaporation to obtain product 1. Further, the acrylate mentioned in step A1 is one of lauryl acrylate, decyl acrylate, hexadecyl acrylate, or tetradecyl acrylate; Further, the molar ratio of 1H-imidazol-5-propanol and acrylate in step A1 is 1:1.5-2; Step A2: Mix product 1 and DMF evenly, cool to 0°C in an ice-water bath, add sodium hydride in 5 portions with 2-minute intervals, maintain 0°C and stir for 30 minutes, raise the temperature to room temperature and continue stirring for 30 minutes, then slowly add 5-chloropentanal DMF solution dropwise over 20-30 minutes, and then stir at room temperature for 12 hours. After the reaction is complete, perform post-treatment to obtain the aldehyde-terminated modifier. Further, the post-processing described in step A2 is as follows: cool the system to 0°C in an ice-water bath, slowly add 20-60 mL of saturated ammonium chloride solution, then add 30-90 mL of ethyl acetate for extraction, collect the organic phase, wash with 30 mL of saturated ammonium chloride, dry with 10-20 g of anhydrous sodium sulfate, filter, rotary evaporate, purify by column chromatography, and rotary evaporate a second time. Furthermore, in step A2, the ratio of product 1, DMF, sodium hydride, and 5-chloropentanal DMF solution is 0.01-0.03 mol: 200 mL: 0.48-1.44 g: 5-15 mL; Further, in step A2, the ratio of 5-chloropentanal to DMF in the 5-chloropentanal DMF solution is 1.98 g: 5 mL; Step A3: Mix the alkalized and swollen chitosan in methanol and stir until homogeneous. Add the aldehyde-terminated modifier and stir for 24 hours. Then slowly add 5 wt% sodium borohydride aqueous solution and continue stirring for 24 hours. Adjust the pH of the system to neutral, filter under reduced pressure, collect the filter cake, wash and dry it to obtain imidazole chitosan. Further, the washing described in step A3 is as follows: washing twice with methanol aqueous solution and twice with methanol, with the volume ratio of methanol aqueous solution being 1:1; Furthermore, in step A3, the ratio of the alkali-swelled chitosan, methanol, aldehyde-terminated modifier, and sodium borohydride aqueous solution is 1g:50mL:1.5-2.5g:5-8mL. Further, the alkalized and swollen chitosan described in step A3 is prepared by the following steps: 2g of chitosan is ultrasonically dispersed evenly in 50mL of isopropanol, 5g of potassium hydroxide is added and stirred for 24h, washed with water, and dried to obtain the product; Step A4: Mix imidazole chitosan in isopropanol and stir until homogeneous. Then slowly add sodium 2-chloroethylsulfonate isopropanol solution and stir for 8-10 hours. After the reaction is complete, remove the supernatant, add water and adjust the pH of the system to neutral. Add ethanol to precipitate, filter, wash with ethanol, and dry to obtain chitosan-based modifier. Further, in step A4, the ratio of imidazole chitosan, isopropanol, sodium 2-chloroethyl sulfonate isopropanol solution, water and ethanol is 2g:50mL:10-15mL:100mL:200mL. Further, the sodium 2-chloroethylsulfonate isopropanol solution described in step A4 is prepared by mixing and stirring sodium 2-chloroethylsulfonate and isopropanol at a ratio of 5g:10mL.

[0006] The beneficial effects of this invention are: The conductive coating for carbon-coated aluminum foil of the present invention is composed of conductive filler, binder, chitosan-based modifier and solvent; wherein, the conductive filler is a mixture of conductive graphite, carbon nanotubes and graphene; the binder is polyacrylic acid and carboxylated nanocellulose; the conductive coating not only has excellent conductivity, but also has the advantages of high adhesion and high wettability, therefore, it has a good application prospect in carbon-coated aluminum foil.

[0007] The chitosan-based modifier in this invention uses chitosan as the main chain, and then utilizes its contained amino and hydroxyl groups for graft modification. An aldehyde modifier containing imidazole groups and long-chain hydrophobic alkyl groups, along with sodium 2-chloroethylsulfonate, is grafted onto its surface. The chitosan-based modifier reduces surface tension by "anchoring the aqueous phase with the hydrophilic end and facing the air with the hydrophobic end," thereby improving wettability. The remaining amino and hydroxyl groups on the chitosan main chain, as well as the introduced strongly hydrophilic sulfonic acid groups, can strongly bind with water molecules, promoting the rapid migration of modifier molecules to the coating / air and coating / aluminum foil interfaces. The grafted long-chain alkyl groups are hydrophobic; they align towards the air or aluminum foil surface at the interface, effectively reducing the surface tension of the coating to below the surface energy of the aluminum foil, thus achieving perfect spreading. Furthermore, isopropanol acts not only as a solvent but also as a surfactant, synergistically working with the modifier to further reduce dynamic surface tension and increase the coating speed window.

[0008] The free amino groups on chitosan can react with the carboxyl groups of PAA during the drying process to form amide bonds or ionic crosslinks. This crosslinks the entire coating into a dense network, thereby improving the adhesion of the coating. The amino and hydroxyl groups on the chitosan backbone are excellent ligands, capable of forming stable five- or six-membered ring chelates with aluminum atoms in the alumina or aluminum hydroxide layer on the aluminum foil surface, thus improving the adhesion of the coating to the aluminum foil. In addition, chitosan is a flexible polymer that can effectively absorb and disperse the internal stress generated during coating drying or battery cycling, preventing the coating from cracking or peeling. The imidazole ring in the modifier has an electron-rich aromatic structure that can undergo strong π-π stacking interactions with the delocalized π-electron system on the surface of CNTs and graphene. This allows the modifier to be "firmly" adsorbed onto the surface of carbon materials, an advantage that is difficult for other common surfactants to match. Detailed Implementation

[0009] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0010] Example 1: Chitosan-based modifier prepared by the following steps: Step A1: Add 0.1 mol 1H-imidazol-5-propanol and 100 mL anhydrous methanol to the reactor and stir and mix evenly at room temperature and under nitrogen. While stirring, add 0.15 mol lauryl acrylate, then heat to 35 °C and react for 4 h. Remove the solvent and excess lauryl acrylate by rotary evaporation to obtain product 1. Step A2: Mix 0.01 mol of product 1 and 200 mL of DMF until homogeneous, cool to 0°C in an ice-water bath, add 0.48 g of sodium hydride in 5 portions, 2 min apart, maintain 0°C and stir for 30 min, then heat to room temperature and continue stirring for 30 min, then slowly add 5 mL of 5-chloropentanal DMF solution over 20 min, then stir at room temperature for 12 h. After the reaction is complete, cool to 0°C in an ice-water bath, slowly add 20 mL of saturated ammonium chloride solution, then add 30 mL of ethyl acetate for extraction, collect the organic phase, wash with 30 mL of saturated ammonium chloride, dry with 10 g of anhydrous sodium sulfate, filter, rotary evaporate, purify by column chromatography, and rotary evaporate a second time to obtain the terminal aldehyde modifier. The ratio of 5-chloropentanal to DMF in the 5-chloropentanal DMF solution is 1.98 g: 5 mL. Step A3: Mix 1g of alkalized and swollen chitosan in 50mL of methanol and stir until homogeneous. Add 1.5g of aldehyde-terminated modifier and stir for 24h. Then slowly add 5mL of 5wt% sodium borohydride aqueous solution and continue stirring for 24h. Adjust the pH of the system to neutral, filter under reduced pressure, collect the filter cake, and wash twice each with methanol-water solution (methanol-water solution volume ratio of 1:1) and methanol. Dry to obtain imidazole chitosan. The alkalized and swollen chitosan is prepared by the following steps: Disperse 2g of chitosan evenly in 50mL of isopropanol using ultrasonication, add 5g of potassium hydroxide and stir for 24h, wash with water, and dry to obtain the final product. Step A4: Mix 2g of imidazole chitosan in 50mL of isopropanol and stir until homogeneous. Then slowly add 10mL of sodium 2-chloroethylsulfonate isopropanol solution and stir for 8 hours. After the reaction is complete, remove the supernatant, add 100mL of water, adjust the pH of the system to neutral, add 200mL of ethanol to precipitate, filter, wash with ethanol, and dry to obtain chitosan-based modifier. The sodium 2-chloroethylsulfonate isopropanol solution is prepared by mixing sodium 2-chloroethylsulfonate and isopropanol in a ratio of 5g:10mL.

[0011] Example 2: Chitosan-based modifier prepared by the following steps: Step A1: Add 0.1 mol 1H-imidazol-5-propanol and 100 mL anhydrous methanol to the reactor and stir and mix evenly under nitrogen conditions at room temperature. While stirring, add 0.8 mol decyl acrylate, then heat to 35℃ and react for 5 h. Remove the solvent and excess decyl acrylate by rotary evaporation to obtain product 1. Step A2: Mix 0.02 mol of product 1 and 200 mL of DMF until homogeneous, cool to 0°C in an ice-water bath, add 0.96 g of sodium hydride in 5 portions, 2 min apart, maintain 0°C and stir for 30 min, then heat to room temperature and continue stirring for 30 min. Then slowly add 10 mL of 5-chloropentanal DMF solution over 25 min, and stir at room temperature for 12 h. After the reaction is complete, cool to 0°C in an ice-water bath, slowly add 40 mL of saturated ammonium chloride solution, then add 60 mL of ethyl acetate for extraction, collect the organic phase, wash with 30 mL of saturated ammonium chloride, dry with 15 g of anhydrous sodium sulfate, filter, rotary evaporate, purify by column chromatography, and rotary evaporate a second time to obtain the terminal aldehyde modifier. The ratio of 5-chloropentanal to DMF in the 5-chloropentanal DMF solution is 1.98 g: 5 mL. Step A3: Mix 1g of alkalized and swollen chitosan in 50mL of methanol and stir until homogeneous. Add 2g of aldehyde-terminated modifier and stir for 24h. Then slowly add 6.5mL of 5wt% sodium borohydride aqueous solution and continue stirring for 24h. Adjust the pH of the system to neutral, filter under reduced pressure, collect the filter cake, and wash twice each with methanol-water solution (methanol-water solution volume ratio of 1:1) and methanol. Dry to obtain imidazole chitosan. The alkalized and swollen chitosan is prepared by the following steps: Disperse 2g of chitosan evenly in 50mL of isopropanol by ultrasonication, add 5g of potassium hydroxide and stir for 24h, wash with water, and dry to obtain the product. Step A4: Mix 2g of imidazole chitosan in 50mL of isopropanol and stir until homogeneous. Then slowly add 12.5mL of sodium 2-chloroethylsulfonate isopropanol solution and stir for 9 hours. After the reaction is complete, remove the supernatant, add 100mL of water, adjust the pH of the system to neutral, add 200mL of ethanol to precipitate, filter, wash with ethanol, and dry to obtain chitosan-based modifier. The sodium 2-chloroethylsulfonate isopropanol solution is prepared by mixing sodium 2-chloroethylsulfonate and isopropanol in a ratio of 5g:10mL.

[0012] Example 3: Chitosan-based modifier prepared by the following steps: Step A1: Add 0.1 mol 1H-imidazol-5-propanol and 100 mL anhydrous methanol to the reactor and stir and mix evenly at room temperature and under nitrogen. While stirring, add 0.2 mol hexadecyl acrylate, then heat to 35℃ and react for 6 h. Remove the solvent and excess hexadecyl acrylate by rotary evaporation to obtain product 1. Step A2: Mix 0.03 mol of product 1 and 200 mL of DMF until homogeneous, cool to 0°C in an ice-water bath, add 1.44 g of sodium hydride in 5 portions, 2 min apart, maintain 0°C and stir for 30 min, raise the temperature to room temperature and continue stirring for 30 min, then slowly add 15 mL of 5-chloropentanal DMF solution over 30 min, stir at room temperature for 12 h. After the reaction is complete, cool to 0°C in an ice-water bath, slowly add 60 mL of saturated ammonium chloride solution, then add 90 mL of ethyl acetate for extraction, collect the organic phase, wash with 30 mL of saturated ammonium chloride, dry with 20 g of anhydrous sodium sulfate, filter, rotary evaporate, purify by column chromatography, and rotary evaporate a second time to obtain the terminal aldehyde modifier. The ratio of 5-chloropentanal to DMF in the 5-chloropentanal DMF solution is 1.98 g: 5 mL. Step A3: Mix 1g of alkalized and swollen chitosan in 50mL of methanol and stir until homogeneous. Add 2.5g of aldehyde-terminated modifier and stir for 24h. Then slowly add 8mL of 5wt% sodium borohydride aqueous solution and continue stirring for 24h. Adjust the pH of the system to neutral, filter under reduced pressure, collect the filter cake, and wash twice each with methanol-water solution (methanol-water solution volume ratio of 1:1) and methanol. Dry to obtain imidazole chitosan. The alkalized and swollen chitosan is prepared by the following steps: Disperse 2g of chitosan evenly in 50mL of isopropanol using ultrasonication, add 5g of potassium hydroxide and stir for 24h, wash with water, and dry to obtain the final product. Step A4: Mix 2g of imidazole chitosan in 50mL of isopropanol and stir until homogeneous. Then slowly add 15mL of sodium 2-chloroethylsulfonate isopropanol solution and stir for 10h. After the reaction is complete, remove the supernatant, add 100mL of water, adjust the pH of the system to neutral, add 200mL of ethanol to precipitate, filter, wash with ethanol, and dry to obtain chitosan-based modifier. The sodium 2-chloroethylsulfonate isopropanol solution is prepared by mixing sodium 2-chloroethylsulfonate and isopropanol in a ratio of 5g:10mL.

[0013] Example 4: A method for preparing a highly wettable conductive coating for carbon-coated aluminum foil, comprising the following steps: Weigh the raw materials according to the weight proportions, and mix and stir 5 parts conductive graphite, 20 parts carbon nanotubes, 15 parts graphene, 20 parts polyacrylic acid, 10 parts carboxylated nanocellulose, 5 parts chitosan-based modifier prepared in Example 1, 150 parts deionized water and 50 parts isopropanol to obtain a highly wettable conductive coating for carbon-coated aluminum foil.

[0014] Example 5: A method for preparing a highly wettable conductive coating for carbon-coated aluminum foil, comprising the following steps: Weigh the raw materials according to the weight proportions, and mix and stir 12 parts conductive graphite, 25 parts carbon nanotubes, 18 parts graphene, 25 parts polyacrylic acid, 13 parts carboxylated nanocellulose, 8 parts chitosan-based modifier prepared in Example 2, 200 parts deionized water and 75 parts isopropanol to obtain a highly wettable conductive coating for carbon-coated aluminum foil.

[0015] Example 6: A method for preparing a highly wettable conductive coating for carbon-coated aluminum foil, comprising the following steps: Weigh the raw materials according to the weight proportions, and mix and stir 10 parts conductive graphite, 30 parts carbon nanotubes, 20 parts graphene, 30 parts polyacrylic acid, 15 parts carboxylated nanocellulose, 10 parts chitosan-based modifier prepared in Example 3, 250 parts deionized water and 100 parts isopropanol to obtain a highly wettable conductive coating for carbon-coated aluminum foil.

[0016] Comparative Example 1: This comparative example is a conductive coating for carbon-coated aluminum foil. The difference between this example and Example 6 is that the chitosan-based modifier prepared in Example 3 was not added. All other aspects are the same.

[0017] Comparative Example 2: This comparative example is a conductive coating for carbon-coated aluminum foil. The difference between this example and Example 6 is that chitosan is used instead of the chitosan-based modifier prepared in Example 3. All other aspects are the same.

[0018] Comparative Example 3: This comparative example is a conductive coating for carbon-coated aluminum foil. The difference from Example 6 is that the chitosan-based modifier prepared in Example 3 is replaced with dodecyltrimethylammonium bromide surfactant.

[0019] Comparative Example 4: This comparative example is a conductive coating for carbon-coated aluminum foil. The difference from Example 6 is that deionized water is used instead of isopropanol.

[0020] The performance of the conductive coatings used to prepare carbon-coated aluminum foils in Examples 4-6 and Comparative Examples 1-4 was tested: Adhesion performance test: determined according to GB / T 9286-2021 "Cross-cut test of paint and varnish film"; Peel strength test: The sample is coated on aluminum foil, the dry film thickness is controlled at 10±1μm, baked at 80℃ for 30min, and the peel strength test is carried out, referring to the standard GB / T 2792-2014 "Test method for peel strength of adhesive tape"; Wetting test: Use a #4 RDS wire rod to apply a wet film coating to the aluminum foil and observe the wet film condition; The test results are shown in Table 1: Table 1: Performance Test Results

[0021] As can be seen from Table 1, the conductive coating for carbon-coated aluminum foil prepared by the present invention has excellent wettability, high adhesion to aluminum foil, and high peel strength.

[0022] The above content is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the scope defined by the inventive concept, they should all fall within the protection scope of the present invention.

Claims

1. A high-wettability conductive paint for carbon-coated aluminum foil, characterized by, The raw materials include the following parts by weight: 5-10 parts conductive graphite, 20-30 parts carbon nanotubes, 15-20 parts graphene, 20-30 parts polyacrylic acid, 10-15 parts carboxylated nanocellulose, 5-10 parts chitosan-based modifier, 150-250 parts deionized water, and 50-100 parts isopropanol. The chitosan-based modifier is prepared by reacting the amino groups and terminal aldehyde groups in chitosan with the amino groups in chitosan, and then reacting the hydroxyl groups in chitosan with sodium 2-chloroethylsulfonate. The terminal aldehyde group modifier is prepared by reacting product 1 with 5-chloropentanal. Product 1 is prepared by reacting 1H-imidazol-5-propanol with acrylate.

2. The highly wettable conductive coating for carbon-coated aluminum foil according to claim 1, characterized in that, The chitosan-based modifier is prepared by the following steps: Step A1: Add 1H-imidazol-5-propanol and anhydrous methanol to the reactor and stir and mix evenly under nitrogen conditions at room temperature. Add acrylate while stirring, then heat to 35℃ and react for 4-6 hours. Remove the solvent and excess acrylate by rotary evaporation to obtain product 1. Step A2: Mix product 1 and DMF evenly, cool to 0°C in an ice-water bath, add sodium hydride in 5 portions with 2-minute intervals, maintain 0°C and stir for 30 minutes, raise the temperature to room temperature and continue stirring for 30 minutes, then slowly add 5-chloropentanal DMF solution dropwise over 20-30 minutes, and then stir at room temperature for 12 hours. After the reaction is complete, perform post-treatment to obtain the aldehyde-terminated modifier. Step A3: Mix the alkalized and swollen chitosan in methanol and stir until homogeneous. Add the aldehyde-terminated modifier and stir for 24 hours. Then slowly add 5 wt% sodium borohydride aqueous solution and continue stirring for 24 hours. Adjust the pH of the system to neutral, filter under reduced pressure, collect the filter cake, wash and dry it to obtain imidazole chitosan. Step A4: Mix imidazole chitosan in isopropanol and stir until homogeneous. Then slowly add sodium 2-chloroethylsulfonate isopropanol solution and stir for 8-10 hours. After the reaction is complete, remove the supernatant, add water, adjust the pH of the system to neutral, add ethanol to precipitate, filter, wash with ethanol, and dry to obtain chitosan-based modifier.

3. The highly wettable conductive coating for carbon-coated aluminum foil according to claim 2, characterized in that, The acrylate mentioned in step A1 is one of lauryl acrylate, decyl acrylate, hexadecyl acrylate, or tetradecyl acrylate.

4. The highly wettable conductive coating for carbon-coated aluminum foil according to claim 2, characterized in that, The molar ratio of 1H-imidazol-5-propanol and acrylate in step A1 is 1:1.5-2.

5. The highly wettable conductive coating for carbon-coated aluminum foil according to claim 2, characterized in that, In step A2, the ratio of product 1, DMF, sodium hydride, and 5-chloropentanal DMF solution is 0.01-0.03 mol: 200 mL: 0.48-1.44 g: 5-15 mL.

6. The highly wettable conductive coating for carbon-coated aluminum foil according to claim 2, characterized in that, In step A2, the ratio of 5-chloropentanal to DMF in the 5-chloropentanal DMF solution is 1.98 g: 5 mL.

7. The highly wettable conductive coating for carbon-coated aluminum foil according to claim 2, characterized in that, In step A3, the ratio of the amount of chitosan, methanol, aldehyde-terminated modifier, and sodium borohydride aqueous solution used for alkali-swelling is 1g:50mL:1.5-2.5g:5-8mL.

8. The highly wettable conductive coating for carbon-coated aluminum foil according to claim 2, characterized in that, The alkalized and swollen chitosan described in step A3 is prepared by the following steps: 2g of chitosan is ultrasonically dispersed evenly in 50mL of isopropanol, 5g of potassium hydroxide is added and stirred for 24h, washed with water, and dried to obtain the product.

9. A highly wettable conductive coating for carbon-coated aluminum foil according to claim 2, characterized in that, In step A4, the ratio of imidazole chitosan, isopropanol, sodium 2-chloroethyl sulfonate isopropanol solution, water, and ethanol is 2g:50mL:10-15mL:100mL:200mL.

10. A highly wettable conductive coating for carbon-coated aluminum foil according to claim 2, characterized in that, The sodium 2-chloroethylsulfonate isopropanol solution described in step A4 is prepared by mixing and stirring sodium 2-chloroethylsulfonate and isopropanol at a ratio of 5g:10mL.

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