A copper surface antioxidant for lithium battery copper foil and a preparation method and application thereof

Abstract

The present application belongs to the technical field of lithium battery copper foil, and particularly relates to a copper surface antioxidant for lithium battery copper foil, a preparation method and application thereof. The copper surface antioxidant for lithium battery copper foil comprises an antioxidant A agent and an antioxidant B agent. The antioxidant A agent comprises tributyl phosphate and an alcohol solvent, and the volume ratio of the tributyl phosphate and the alcohol solvent is 10-20:1000. The antioxidant B agent comprises a corrosion inhibitor, a film forming agent and an acid solution. The copper surface antioxidant for lithium battery copper foil can quickly form a film on the copper surface, and a dense chemical conversion film can be formed in 5-10 seconds, so that the copper surface is isolated from air and is prevented from being oxidized by air. The copper surface antioxidant for lithium battery copper foil can be baked at a high temperature of 150 DEG C for 10 min without discoloration. The copper surface antioxidant for lithium battery copper foil does not contain chromium, has good environmental protection, and is free of nitrogen azole, imidazole, thiazole and derivatives thereof. The reagents used are low-toxicity, have good weldability, and are easy to be treated in sewage.

Description

Technical Field

[0001] This invention belongs to the field of lithium battery copper foil technology, specifically relating to a copper surface antioxidant for lithium battery copper foil, its preparation method, and its application. Background Technology

[0002] In recent years, with increasing environmental awareness, lithium-ion batteries have seen a surge in demand in fields such as new energy vehicles, mobile phone batteries, and weaponry due to their superior performance, including high energy density and fast energy transfer. Copper foil, as the current collector for the negative electrode of lithium-ion batteries, is a crucial basic material in the lithium battery industry.

[0003] Oxidation is a common quality issue with lithium-ion battery copper foil. Therefore, passivation is the final step in the production of lithium-ion battery copper foil to prevent surface oxidation and increase its shelf life. Common passivation methods are mainly divided into chromate passivation and chromium-free passivation. However, chromium is a toxic heavy metal element that poses serious threats to human health and the ecological environment. Developing new, green, and environmentally friendly chromium-free passivation technologies to replace chromate passivation has become a current research hotspot. There are currently some patents and processes related to copper foil anti-oxidation. For example, Chinese patent CN110923755A discloses a surface anti-oxidation process for lithium battery copper foil. The surface anti-oxidation process is carried out in an anti-oxidation tank and includes: (1) preparation of initial anti-oxidation solution: the initial anti-oxidation solution is a mixture of chromium anhydride, glucose and water, wherein the mass ratio of chromium anhydride to glucose is chromium anhydride: glucose powder = 1:3 to 1:5, and the concentration of glucose in the initial anti-oxidation solution is 1.5 to 2.7 g / L; (2) control of anti-oxidation electroplating parameters: after the lithium battery copper foil is immersed in the initial anti-oxidation solution, the following parameters are controlled until the end: the circulation flow rate of the anti-oxidation solution is 1.8 to 2.5 m 3 The process involves a temperature of 32–34°C, a pH of 5–6, and a hexavalent chromium concentration of 0.5–0.7 g / L. This invention uses a traditional chromium anhydride and glucose system for passivation. This process contains chromium, which is inconsistent with the concept of green development and is destined to be phased out. Chinese patent CN110004436A discloses a copper foil passivating agent using a methylbenzotriazole derivative as the main component. This invention achieves chromium-free passivation; however, the system still contains azole components, which not only affects the solderability of the treated copper surface but also makes wastewater treatment more difficult.

[0004] In conclusion, it is essential to develop a copper surface antioxidant for lithium battery copper foil that is chromium-free, environmentally friendly, conforms to the concept of green development, is free of nitrile, imidazole, thiazole and their derivatives, has good solderability on the copper surface after treatment, and is easy to treat in wastewater. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a copper surface antioxidant for lithium-ion battery copper foil, its preparation method, and its application. The copper surface antioxidant provided by this invention can rapidly form a film on the copper surface, creating a dense chemical conversion film within 5-10 seconds, thus isolating the copper surface from air and preventing oxidation. Copper foil treated with this copper surface antioxidant can be baked at 150°C for 10 minutes without discoloration. The copper surface antioxidant provided by this invention is chromium-free, environmentally friendly, and conforms to the concept of green development. It also contains no nitrile, imidazole, thiazole, or their derivatives, and the reagents used are low in toxicity, exhibit good solderability, and are easy to treat in wastewater.

[0006] The technical solution of this invention is:

[0007] An antioxidant for copper foil used in lithium batteries includes antioxidant A and antioxidant B; antioxidant A includes tributyl phosphate and an alcohol solvent, wherein the volume ratio of tributyl phosphate to alcohol solvent is 10-20:1000; antioxidant B includes a corrosion inhibitor, a film-forming agent, and an acid solution.

[0008] Furthermore, the volume ratio of antioxidant A to antioxidant B is (5-8):(5-2).

[0009] Further, the alcohol solvent is one or more selected from 1,3-propanediol, glycerol, 1,2-propanediol, n-propanol, and ethylene glycol.

[0010] Preferably, the corrosion inhibitor comprises triethanolamine borate, wherein the volume ratio of triethanolamine borate to acid solution is 10-20:1000.

[0011] Furthermore, the corrosion inhibitor also includes cerium sulfate, sodium molybdate, or sodium tungstate.

[0012] Furthermore, when the corrosion inhibitor further includes cerium sulfate, the mass-to-volume ratio of cerium sulfate to the acid solution is 0.2-1 g / L; when the corrosion inhibitor further includes sodium molybdate, the mass-to-volume ratio of sodium molybdate to the acid solution is 0.5-1 g / L; when the corrosion inhibitor further includes sodium tungstate, the mass-to-volume ratio of sodium tungstate to the acid solution is 0.5-1 g / L.

[0013] Furthermore, the film-forming agent is one or more of polyvinylpyrrolidone, sodium alginate, chitosan, sodium polyacrylate, and polyvinyl alcohol.

[0014] Further, when the film-forming agent is polyvinylpyrrolidone, the mass-to-volume ratio of polyvinylpyrrolidone to the acid solution is 1-5 g / L; when the film-forming agent is sodium alginate, the mass-to-volume ratio of sodium alginate to the acid solution is 0.1-0.5 g / L; when the film-forming agent is chitosan, the mass-to-volume ratio of chitosan to the acid solution is 5-10 g / L; when the film-forming agent is sodium polyacrylate, the mass-to-volume ratio of sodium polyacrylate to the acid solution is 1-5 g / L; when the film-forming agent is polyvinyl alcohol, the mass-to-volume ratio of polyvinyl alcohol to the acid solution is 5-10 g / L.

[0015] Furthermore, the acid solution is a hydrochloric acid solution or an acetic acid solution.

[0016] Furthermore, the hydrochloric acid solution has a volume fraction of 3%-10%, and the acetic acid solution has a volume fraction of 5%-20%.

[0017] This invention also provides a method for preparing the copper-surface antioxidant for lithium-ion battery copper foil, comprising the following steps:

[0018] S1. Dissolve tributyl phosphate in an alcohol solvent to obtain antioxidant A;

[0019] S2. Dissolve the corrosion inhibitor and film-forming agent in an acid solution to obtain antioxidant agent B;

[0020] S3. Mix antioxidant A obtained in step S1 and antioxidant B obtained in step S2 to obtain the final product.

[0021] Another object of the present invention is to provide the application of the copper surface antioxidant for lithium battery copper foil in lithium battery copper foil.

[0022] A surface treatment method for lithium battery copper foil includes immersing the lithium battery copper foil to be treated with anti-oxidation in the aforementioned copper surface anti-oxidant for lithium battery copper foil, soaking it at 20-30°C for 3-8 seconds, without washing with water, and drying it at 70-80°C.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] In this invention, the tributyl phosphate in antioxidant A can form an organic film on the copper surface, while the esters and inorganic salts in antioxidant B have a good synergistic effect with tributyl phosphate, enabling the composite corrosion inhibitor to quickly form an adsorption film and an oxide film adhering to the copper surface, thereby preventing the adsorption reaction of corrosive ions on the copper surface, and hindering the charge transfer of electrochemical reactions, inhibiting anodic and cathodic polarization processes, thereby improving corrosion resistance.

[0025] (1) The copper surface antioxidant for lithium-ion battery copper foil provided by the present invention can quickly form a film on the copper surface. A dense chemical conversion film can be formed in 5 to 10 seconds, which isolates the copper surface from the air and prevents air oxidation. The copper foil treated with the copper surface antioxidant for lithium-ion battery copper foil of the present invention can be baked at a high temperature of 150°C for 10 minutes without discoloration.

[0026] (2) This invention is free of chromium, has good environmental performance, and is free of nitrazole, imidazole, thiazole and their derivatives. The reagents used are low in toxicity, have good solderability, and are easy to treat wastewater.

[0027] (3) The preparation method of the copper surface antioxidant for lithium battery copper foil of the present invention is simple. When using the copper surface antioxidant for lithium battery copper foil of the present invention to perform surface treatment on lithium battery copper foil, the operation is simple, the cost is low, the working conditions are mild, and no water washing is required. Attached Figure Description

[0028] Figure 1 Images shown are of lithium-ion battery copper foils from Examples 1-3 after anti-oxidation treatment and high-temperature baking tests. Figure 1 Image A shows the lithium-ion battery copper foil from Example 1 after anti-oxidation treatment and high-temperature baking test. Figure 1 Image B shows the lithium-ion battery copper foil from Example 2 after anti-oxidation treatment and high-temperature baking test. Figure 1 C is a picture of the lithium battery copper foil after anti-oxidation treatment in Example 3, after high-temperature baking test;

[0029] Figure 2 These are images of lithium-ion battery copper foils treated in Comparative Examples 1-3, after being subjected to a high-temperature baking test. Figure 2 Image A shows the lithium-ion battery copper foil of Comparative Example 1 after anti-oxidation treatment and high-temperature baking test. Figure 2 Image B shows the lithium-ion battery copper foil from Comparative Example 2 after high-temperature baking test following antioxidant treatment. Figure 2 C is a picture of the lithium battery copper foil of Comparative Example 3 after high-temperature baking test without antioxidant treatment;

[0030] Figure 3 Images are shown below of lithium-ion battery copper foils treated in Examples 1-3 and Comparative Examples 1-3 after solderability testing. Figure 3 Image A shows the lithium-ion battery copper foil after solderability testing following the treatment in Example 1. Figure 3 Image B shows the solderability test results of the lithium-ion battery copper foil treated in Example 2. Figure 3 Image C shows the lithium-ion battery copper foil after solderability testing following the treatment in Example 3. Figure 3 Image D shows the lithium-ion battery copper foil after solderability testing following the treatment in Comparative Example 1. Figure 3 E is a picture of the lithium battery copper foil after solderability test following the treatment in Comparative Example 2. Figure 3F is a picture of the solderability test of the lithium battery copper foil without anti-oxidation treatment in Comparative Example 3. Detailed Implementation

[0031] The following specific embodiments further illustrate the content of the present invention, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment used in this invention are conventional reagents, methods, and equipment in this technical field. For example, polyvinylpyrrolidone K30 can be purchased from Tianjin Zhonglian Chemical Reagent Co., Ltd.; sodium alginate can be purchased from Tianjin Zhonglian Chemical Reagent Co., Ltd.; sodium polyacrylate with a molecular weight ≤10000 can be purchased from Tianjin Zhonglian Chemical Reagent Co., Ltd.

[0032] Example 1

[0033] 15 mL of tributyl phosphate was dissolved in 1 L of propylene glycol to obtain antioxidant A; a corrosion inhibitor and a film-forming agent were dissolved in an acid solution to obtain antioxidant B; antioxidant A and antioxidant B were mixed at a volume ratio of 8:2 to obtain a copper surface antioxidant for lithium battery copper foil; wherein the corrosion inhibitor was triethanolamine borate, the film-forming agent was polyvinylpyrrolidone K30; the acid solution was a 10% acetic acid solution; the volume ratio of triethanolamine borate to the acid solution was 15:1000; the mass-volume ratio of polyvinylpyrrolidone K30 to the acid solution was 2 g / L;

[0034] The lithium-ion battery copper foil to be treated with anti-oxidation is placed in the copper surface antioxidant for lithium-ion battery copper foil mentioned above, immersed at 25°C for 5 seconds, without water washing, and dried at 80°C to obtain the lithium-ion battery copper foil after anti-oxidation treatment.

[0035] Example 2

[0036] 10 mL of tributyl phosphate was dissolved in 1 L of propylene glycol to obtain antioxidant A; a corrosion inhibitor and a film-forming agent were dissolved in an acid solution to obtain antioxidant B; antioxidant A and antioxidant B were mixed at a volume ratio of 7:3 to obtain a copper surface antioxidant for lithium battery copper foil; wherein the corrosion inhibitor was triethanolamine borate and sodium molybdate, and the film-forming agent was sodium alginate; the acid solution was a 10% hydrochloric acid solution; the volume ratio of triethanolamine borate to the acid solution was 15:1000; the mass-volume ratio of sodium molybdate to the acid solution was 0.5 g / L; and the mass-volume ratio of sodium alginate to the acid solution was 0.3 g / L.

[0037] The lithium-ion battery copper foil to be treated with anti-oxidation is placed in the copper surface antioxidant for lithium-ion battery copper foil mentioned above, immersed at 25°C for 5 seconds, without water washing, and dried at 80°C to obtain the lithium-ion battery copper foil after anti-oxidation treatment.

[0038] Example 3

[0039] 12 mL of tributyl phosphate was dissolved in 1 L of 1,2-propanediol to obtain antioxidant A; a corrosion inhibitor and a film-forming agent were dissolved in an acid solution to obtain antioxidant B; antioxidant A and antioxidant B were mixed at a volume ratio of 7:3 to obtain a copper surface antioxidant for lithium battery copper foil; wherein the corrosion inhibitor was triethanolamine borate and cerium sulfate, and the film-forming agent was sodium polyacrylate; the acid solution was a 10% hydrochloric acid solution; the volume ratio of triethanolamine borate to the acid solution was 15:1000; the mass-volume ratio of cerium sulfate to the acid solution was 0.3 g / L; and the mass-volume ratio of sodium polyacrylate to the acid solution was 2 g / L.

[0040] The lithium-ion battery copper foil to be treated with anti-oxidation is placed in the copper surface antioxidant for lithium-ion battery copper foil mentioned above, immersed at 25°C for 6 seconds, without water washing, and dried at 70°C to obtain the lithium-ion battery copper foil after anti-oxidation treatment.

[0041] Comparative Example 1

[0042] A corrosion inhibitor and a film-forming agent are dissolved in an acid solution to obtain antioxidant agent B; wherein the corrosion inhibitor is triethanolamine borate and cerium sulfate, and the film-forming agent is sodium polyacrylate; the acid solution is a 10% hydrochloric acid solution; the volume ratio of triethanolamine borate to the acid solution is 15:1000; the mass-volume ratio of cerium sulfate to the acid solution is 0.3 g / L; and the mass-volume ratio of sodium polyacrylate to the acid solution is 2 g / L.

[0043] The lithium-ion battery copper foil to be treated with antioxidant was placed in antioxidant agent B mentioned above, immersed at 25°C for 6 seconds, without washing with water, and dried at 70°C to obtain the lithium-ion battery copper foil after antioxidant treatment.

[0044] Comparative Example 2

[0045] A chromium-containing antioxidant is prepared, which is a mixture of chromium anhydride, glucose and water. The mass concentration of chromium anhydride in the chromium-containing antioxidant is 0.5 g / L and the mass concentration of glucose is 2 g / L. The copper foil to be treated with antioxidant is immersed in the chromium-containing antioxidant and electrolyzed at a current density of 3 ASD for 5 s to obtain a copper foil with a chromium layer.

[0046] Comparative Example 3

[0047] Freshly plated copper foil is washed directly with water and then dried without any anti-oxidation treatment.

[0048] Experiment 1: Performance Testing

[0049] The lithium-ion battery copper foils obtained from Examples 1-3 of the present invention after antioxidant treatment, the lithium-ion battery copper foils of Comparative Example 1 after antioxidant treatment, the copper foils of Comparative Example 2 with chromium layer, and the lithium-ion battery copper foils of Comparative Example 3 without antioxidant treatment were baked at 150°C for 10 min.

[0050] Images of lithium-ion battery copper foil after anti-oxidation treatment and high-temperature baking test in Examples 1-3 are shown below. Figure 1 As shown, where Figure 1 Image A shows the lithium-ion battery copper foil from Example 1 after anti-oxidation treatment and high-temperature baking test. Figure 1 Image B shows the lithium-ion battery copper foil from Example 2 after anti-oxidation treatment and high-temperature baking test. Figure 1 Image C shows the lithium-ion battery copper foil from Example 3 after high-temperature baking test following antioxidant treatment. Figure 1 It can be seen that the lithium-ion battery copper foils of Examples 1-3 of the present invention, after undergoing antioxidant treatment, did not change color after baking at 150°C for 10 minutes. Images of the lithium-ion battery copper foils treated in Examples 1-3 after high-temperature baking tests are shown below. Figure 2 As shown, where Figure 2 Image A shows the lithium-ion battery copper foil of Comparative Example 1 after anti-oxidation treatment and high-temperature baking test. Figure 2 Image B shows the lithium-ion battery copper foil from Comparative Example 2 after high-temperature baking test following antioxidant treatment. Figure 2 Image C shows the lithium-ion battery copper foil from Comparative Example 3 after a high-temperature baking test without anti-oxidation treatment. Figure 2 As can be seen from A, the lithium-ion battery copper foil in Comparative Example 1, after being treated with antioxidants, changed color after baking at 150℃ for 10 minutes. This indicates that Comparative Example 1, which only used antioxidant B, did not achieve the desired effect. Figure 2 As can be seen from B, the lithium-ion battery copper foil in Comparative Example 1, after undergoing antioxidant treatment, did not change color after baking at 150℃ for 10 minutes. Figure 2 As can be seen from C, Comparative Example 3, which was not treated with antioxidants, showed severe surface discoloration.

[0051] Using a colorimeter Figure 1 A, Figure 1 B Figure 1 C Figure 2 A, Figure 2 B Figure 2 C is used for measurement.

[0052] Meaning of Lab value

[0053] L (Lightness): Represents the brightness of the color, ranging from 0 to 100, where 0 represents pure black and 100 represents pure white. Therefore, the larger the value, the whiter the color. In this experiment, this is a secondary reference value; the larger the value, the closer it is to the color of copper itself.

[0054] a (Green-Red Axis): Represents the green-red saturation of the color, ranging from -128 to +127, where -128 represents green and +127 represents red. Therefore, the larger the value, the redder the color. In this experiment, this is a primary reference value; the smaller the value, the less likely it is to appear red.

[0055] b(Blue-Yellow Axis): Represents the blue-yellow hue of the color, ranging from -128 to +127, where -128 represents blue and +127 represents yellow. This value is not relevant to this experiment.

[0056] This invention corresponds to respectively Figure 1 A, Figure 1 B Figure 1 C Figure 2 A, Figure 2 B Figure 2 Table 1 shows a comparison of the L and a values ​​of Examples 1-3 and Comparative Examples 1-3 of C.

[0057] Table 1: Comparison of L and a values ​​in Examples 1-3 and Comparative Examples 1-3 of the present invention

[0058] L value 80.98 80.36 80.14 72.96 81.32 69.64 value of a 17.65 17.49 17.28 19.68 17.09 25.65

[0059] As can be seen from Table 1, the L and a values ​​of the lithium-ion battery copper foils of Examples 1-3 after antioxidant treatment and high-temperature baking tests are very close to those of the lithium-ion battery copper foils of Comparative Example 2 after antioxidant treatment with a chromium-containing antioxidant and high-temperature baking tests. This indicates that the effect of the copper-surface antioxidant used in the lithium-ion battery copper foils of this invention is comparable to that of the chromium-containing antioxidant. However, the L value of the antioxidant-treated lithium-ion battery copper foils of Comparative Example 1 after high-temperature baking tests is significantly lower than that of Examples 1-3 of this invention, while the a value is significantly higher. This demonstrates that only by using antioxidant A and antioxidant B together can the effects of this invention be achieved, further illustrating the synergistic effect between antioxidant A and antioxidant B. In contrast, the L value of the lithium-ion battery copper foil of Comparative Example 3 without anti-oxidation treatment after high-temperature baking test was significantly lower than that of Embodiments 1-3 of the present invention, and the a value of the lithium-ion battery copper foil of Comparative Example 3 without anti-oxidation treatment after high-temperature baking test was significantly higher than that of Embodiments 1-3 of the present invention, indicating severe surface discoloration.

[0060] Test Example 2: Solderability Test

[0061] Solderability can be characterized by its tin-dipping performance. Lithium-ion battery copper foil samples treated with Examples 1-3 and Comparative Examples 1-3 were dipped in tin at a furnace temperature of 280°C, and the surface condition was observed.

[0062] Images of the lithium-ion battery copper foils treated in Examples 1-3 and Comparative Examples 1-3 after solderability testing are shown below. Figure 3 As shown, the image of the lithium-ion battery copper foil treated in Example 1 after a solderability test is as follows. Figure 3 As shown in Figure A, the image of the lithium-ion battery copper foil treated in Example 2 after a solderability test is as follows. Figure 3 As shown in Figure B, the image of the lithium-ion battery copper foil treated in Example 3 after a solderability test is as follows. Figure 3 As shown in Figure C, the image of the lithium-ion battery copper foil treated in Comparative Example 1 after a solderability test is as follows. Figure 3 As shown in Figure D, the image of the lithium-ion battery copper foil treated in Comparative Example 2 after a solderability test is shown below. Figure 3 As shown in E; Comparative Example 3: Image of lithium battery copper foil without anti-oxidation treatment after solderability testing. Figure 3 As shown in F. Figure 3 A through C correspond to Examples 1 through 3, respectively. Figure 3 As can be seen from A to C, the lithium battery copper foil treated in Examples 1-3 showed good surface condition after solderability testing, with a smooth tin layer and no missed plating. Figure 3 D to F correspond to proportions 1 to 3 respectively, from Figure 3 As can be seen from D to F, the tin-plated surfaces of Comparative Examples 1 and 2 are in good condition, with smooth tin layers and no missed plating. However, in Comparative Example 3, the copper foil without anti-oxidation treatment has an uneven tin layer with holes and missed plating. This demonstrates that the anti-oxidation film made using the copper-surface anti-oxidant of this invention for lithium-ion battery copper foil exhibits good solderability, while the solderability of the copper layer without anti-oxidation treatment decreases due to oxidation.

[0063] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations and simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A copper-surface antioxidant for lithium-ion battery copper foil, characterized in that, It is composed of antioxidant A and antioxidant B; antioxidant A is composed of tributyl phosphate and alcohol solvent, wherein the volume ratio of tributyl phosphate to alcohol solvent is 10-20:1000; antioxidant B is composed of corrosion inhibitor, film-forming agent and acid solution; the volume ratio of antioxidant A to antioxidant B is (5-8):(5-2). The corrosion inhibitor is composed of triethanolamine borate, and at least one of cerium sulfate, sodium molybdate, and sodium tungstate. The volume ratio of the triethanolamine borate ester to the acid solution is 10-20:1000; The acid solution is a hydrochloric acid solution or an acetic acid solution; the volume fraction of the hydrochloric acid solution is 3%-10%, and the volume fraction of the acetic acid solution is 5%-20%. When the corrosion inhibitor further includes cerium sulfate, the mass-to-volume ratio of cerium sulfate to the acid solution is 0.2-1 g / L; when the corrosion inhibitor further includes sodium molybdate, the mass-to-volume ratio of sodium molybdate to the acid solution is 0.5-1 g / L; when the corrosion inhibitor further includes sodium tungstate, the mass-to-volume ratio of sodium tungstate to the acid solution is 0.5-1 g / L. The film-forming agent is one or more of polyvinylpyrrolidone, sodium alginate, chitosan, sodium polyacrylate, and polyvinyl alcohol; When the film-forming agent is polyvinylpyrrolidone, the mass-to-volume ratio of polyvinylpyrrolidone to the acid solution is 1-5 g / L; when the film-forming agent is sodium alginate, the mass-to-volume ratio of sodium alginate to the acid solution is 0.1-0.5 g / L; when the film-forming agent is chitosan, the mass-to-volume ratio of chitosan to the acid solution is 5-10 g / L; when the film-forming agent is sodium polyacrylate, the mass-to-volume ratio of sodium polyacrylate to the acid solution is 1-5 g / L; when the film-forming agent is polyvinyl alcohol, the mass-to-volume ratio of polyvinyl alcohol to the acid solution is 5-10 g / L.

2. The copper surface antioxidant for lithium battery copper foil as described in claim 1, characterized in that, The alcohol solvent is one or more of 1,3-propanediol, glycerol, 1,2-propanediol, n-propanol, and ethylene glycol.

3. The method for preparing the copper-surface antioxidant for lithium-ion battery copper foil as described in claim 1 or 2, characterized in that, Includes the following steps: S1. Dissolve tributyl phosphate in an alcohol solvent to obtain antioxidant A; S2. Dissolve the corrosion inhibitor and film-forming agent in an acid solution to obtain antioxidant agent B; S3. Mix antioxidant A obtained in step S1 and antioxidant B obtained in step S2 to obtain the final product.

4. The application of the copper surface antioxidant for lithium battery copper foil as described in any one of claims 1-2 in lithium battery copper foil.

5. A surface treatment method for lithium battery copper foil, characterized in that, The method includes immersing the lithium-ion battery copper foil to be treated with antioxidant in the copper surface antioxidant for lithium-ion battery copper foil as described in any one of claims 1-2, soaking it at 20-30°C for 3-8 seconds, without washing it with water, and drying it at 70-80°C.

Images