Aluminum foil current collector, surface treatment method thereof, and battery pole piece

Abstract

The present invention discloses a surface treatment method for an aluminum foil current collector and a battery electrode. The surface treatment method comprises the following steps: S1, preparing a first treatment liquid of phosphoric acid or nitric acid with a mass concentration of 1 to 10%, immersing the aluminum foil in the first treatment liquid, and ultrasonically cleaning the aluminum foil for 0.1 to 10 minutes; S2, adding a chromium-containing compound, a polyacrylic resin, and a fluoride to deionized water to prepare a second treatment liquid, wherein the chromium-containing compound is chromium phosphate or chromium nitrate, and the fluoride is one or more of chromium fluoride, magnesium fluoride, ammonium fluoride, and hydrofluoric acid; rolling the second treatment liquid onto the surface of the aluminum foil obtained in step S1, and drying the liquid to obtain the aluminum foil current collector. The first and second treatment liquids of the present invention have simple formulations and a simple process. The prepared aluminum foil can achieve a dyne value of 55 or above, significantly improves corrosion resistance in electrolyte, and enhances adhesion to the carbon coating layer.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, and in particular to an aluminum foil current collector, a surface treatment method thereof, and a battery pole piece. Background Art

[0002] Currently, lithium-ion and sodium-ion batteries use aluminum foil as a current collector, upon which active materials are coated to create pole pieces. During the active material slurry coating process, the low dyne value of the aluminum foil surface results in poor leveling of the slurry; the carbon coating or active material exhibits poor adhesion to the aluminum foil; and, as the current collector, the aluminum foil is exposed to the electrolyte for extended periods within the battery, which can lead to corrosion.

[0003] Dyne value refers to the surface tension value of the membrane tested by a dyne pen, and is also the decisive standard for membrane surface treatment. Generally speaking, the higher the dyne value, the easier it is to adhere. The surface dyne value of existing aluminum foil current collectors needs to be improved urgently.

[0004] Currently, most manufacturers use aluminum foil current collectors that have not undergone surface treatment and have a dyne value of about 30. Chinese invention patent publication number CN115369466A discloses a pretreatment method for positive electrode current collector aluminum foil, a positive electrode current collector, and a battery. After surface treatment, the surface dyne value of the aluminum foil current collector can reach about 36, which still needs to be improved.

[0005] Therefore, it is necessary to develop a surface treatment method for aluminum foil current collector to increase the dyne value of the aluminum foil surface, improve the leveling of the slurry; improve the adhesion between the aluminum foil and the active material or the carbon coating layer; and improve the corrosion resistance of the aluminum foil to the electrolyte. Summary of the Invention

[0006] The purpose of the present invention is to solve the shortcomings of the above-mentioned background technology and provide a surface treatment method for aluminum foil current collector, which is used to improve the dyne value of the aluminum foil surface and improve the leveling of the slurry; improve the adhesion between the aluminum foil and the active material or the carbon coating layer; and improve the corrosion resistance of the aluminum foil to the electrolyte.

[0007] The technical solution of the present invention is: an aluminum foil current collector, characterized in that the dyne value of the aluminum foil current collector is greater than 55mN / m.

[0008] Preferably, the dyne value of the aluminum foil current collector is greater than 55 mN / m and less than 70 mN / m, and the dyne value of the aluminum foil current collector is further preferably greater than 55 mN / m and less than 65 mN / m.

[0009] The present invention also provides a surface treatment method for the aluminum foil current collector, which is characterized by comprising the following steps:

[0010] S1. Prepare phosphoric acid or nitric acid as a first treatment liquid, and soak the aluminum foil in the first treatment liquid for cleaning;

[0011] S2. Add a chromium-containing compound, a polyacrylic resin, and a fluoride to a solvent to prepare a second treatment liquid, apply the second treatment liquid to the surface of the aluminum foil obtained in step S1, and dry to obtain an aluminum foil current collector.

[0012] Preferably,

[0013] In step S1, the mass concentration of the first treatment liquid is 1-10%, the cleaning is ultrasonic cleaning, and the ultrasonic cleaning treatment time is 0.1-10 minutes;

[0014] And / or in step S2, the chromium-containing compound is chromium phosphate or chromium nitrate, the fluoride is one or more of chromium fluoride, magnesium fluoride, ammonium fluoride, and hydrofluoric acid, the mass concentration of the chromium-containing compound in the second treatment liquid is 1-10%, the mass concentration of the polyacrylic acid resin is 2-15%, and the mass concentration of the fluoride is 0.1-10%.

[0015] Furthermore, in step S1, the mass concentration of phosphoric acid or nitric acid in the first treatment liquid is 1-5%; in step S2, the mass concentration of the chromium-containing compound in the second treatment liquid is 2-5%, the mass concentration of the polyacrylic acid resin is 4-6%, and the mass concentration of the fluoride is 0.3-1%.

[0016] Preferably, in step S2, the drying process is performed at 100-200° C. for 0.5-10 min.

[0017] Preferably, in step S2, the solvent is deionized water, and the polyacrylic acid resin is one or more of polyacrylic acid, polymethyl acrylate, and a copolymer of acrylic acid and maleic acid.

[0018] Preferably, in step S2, the second treatment liquid is rolled in an amount of 1 to 20 g / m 2 .

[0019] Preferably, the steps include:

[0020] S1. Prepare nitric acid with a mass concentration of 5% as a first treatment solution, soak the aluminum foil in the first treatment solution, and perform ultrasonic cleaning for 5 minutes;

[0021] S2. Add a chromium-containing compound, a polyacrylic acid resin, and a fluoride to deionized water to prepare a second treatment solution, wherein the chromium-containing compound is chromium phosphate, the polyacrylic acid resin is polymethyl acrylate, and the fluoride is chromium fluoride. The mass concentration of the chromium-containing compound in the second treatment solution is 5%, the mass concentration of the polyacrylic acid resin is 4%, and the mass concentration of the fluoride is 1%. The second treatment solution is roll-coated on the surface of the aluminum foil obtained in step S1, and the roll-coating amount is 5 g / m 2 , and dried at 180°C for 2 min to obtain the aluminum foil current collector.

[0022] The present invention also provides a battery pole piece, comprising any of the above-mentioned aluminum foil current collectors or the aluminum foil current collectors prepared by any of the methods, and an active material arranged on the surface of the aluminum foil current collector.

[0023] Preferably, it also includes a carbon coating layer arranged between the aluminum foil current collector and the active material.

[0024] The present invention also provides a lithium battery prepared using the battery pole piece mentioned above.

[0025] The method for preparing a battery electrode using the aluminum foil current collector includes:

[0026] A slurry consisting of active materials, conductive agents, and adhesives is directly coated on the surface of the aluminum foil current collector, or carbon is first coated on the surface to make carbon-coated aluminum foil, and then a slurry consisting of active materials, conductive agents, and adhesives is coated on the surface. After drying and compacting, the electrode is formed.

[0027] The working principle of the first treatment liquid of the present invention is that under ultrasonic conditions, nitric acid or phosphoric acid can quickly remove residual oil and oxide layer on the surface of aluminum foil during processing, wherein the mass concentration of phosphoric acid or nitric acid is 1-10%. Too high a mass concentration will cause excessive damage to the surface of the aluminum foil, resulting in the adverse consequence of reduced mechanical properties of the aluminum foil. Too low a mass concentration will not be able to remove residual oil and oxide layer on the surface of the aluminum foil during processing. The preferred concentration range of the first treatment liquid of the present invention is 1-5%.

[0028] In the second treatment liquid of the present invention: the role of the chromium-containing compound (chromium phosphate or chromium nitrate) is to form an anti-corrosion protective layer on the surface of the aluminum foil, the role of the fluoride is to form an anti-oxidation protective layer on the surface of the aluminum foil, and the role of the polyacrylic resin is to increase the affinity between the aluminum foil current collector and the active substance / carbon coating layer, and improve the adhesion. The principle of the synergistic effect of the three to produce a unique effect is that while forming an anti-corrosion and anti-oxidation protective layer on the surface of the aluminum foil, the affinity between the aluminum foil and the active substance is improved. When used as a current collector, the adhesion between the aluminum foil and the active substance / carbon coating layer is effectively improved, preventing the active substance / carbon coating layer from falling off, and at the same time avoiding corrosion and oxidation of the current collector by the electrolyte inside the battery.

[0029] The mass concentration of the chromium-containing compound is 1-10%. Too high a mass concentration will result in excessive chromium content and environmentally unfriendly consequences, while too low a mass concentration will not have any effect. The preferred range of the chromium-containing compound concentration of the present invention is 2-5%.

[0030] The mass concentration of the polyacrylic acid resin is 2-15%. Too high a mass concentration will cause the adverse consequence of increasing the internal resistance of the current collector, while too low a mass concentration will not have the effect of improving the adhesion. The preferred range of the polyacrylic acid resin concentration of the present invention is 4-6%.

[0031] The mass concentration of fluoride is 0.1-10%. Too high a mass concentration will cause the element content to exceed the standard and be unenvironmentally friendly, while too low a mass concentration will not have any effect. The preferred range of the fluoride concentration of the present invention is 0.3-1%.

[0032] The amount of the second treatment liquid to be rolled is 1 to 20 g / m 2 If the amount of roller coating is too large, it will cause coating difficulties, difficulty in drying, and excessive content of related elements, which is not environmentally friendly. If the amount of roller coating is too small, it will not achieve the adverse consequences of anti-corrosion and anti-oxidation and low adhesion. The preferred range of the roller coating amount of the second treatment liquid of the present invention is 3 to 10 g / m 2 .

[0033] The beneficial effects of the present invention are as follows:

[0034] 1. The first treatment liquid contains phosphoric acid or nitric acid, and is combined with ultrasonic cleaning technology to treat the surface of the aluminum foil to remove oil stains and oxide layers on the surface of the aluminum foil, forming a microscopic concave-convex structure.

[0035] 2. The second treatment liquid contains chromium compounds, fluorides, and polyacrylic acid resins, which perform secondary treatment on the surface of the aluminum foil. The formed microstructure plays a protective role while enhancing the polarity of the aluminum foil surface.

[0036] 3. Dyne value refers to the surface tension of the membrane measured by a dyne pen test and is also a decisive criterion for membrane surface treatment. Generally speaking, the higher the dyne value, the easier it is to adhere. The first and second treatment solutions used in the present invention have simple formulations and a simple process. The aluminum foil current collector prepared in this invention can achieve a dyne value of over 55, significantly improving slurry leveling, enhancing the adhesion between the aluminum foil and the active material or carbon coating, and increasing the aluminum foil's corrosion resistance to electrolytes. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the following examples further illustrate the present invention in detail. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention. The following specific examples further illustrate the present invention in detail. Unless otherwise specified, the drugs used in the examples are all commercially available products, and the methods used are conventional methods in the art unless otherwise specified.

[0038] The treatment solution formulations of Examples 1 to 7 and Comparative Examples 3 to 7 are shown in Table 1 below.

[0039] Table 1 Treatment solution formula for Examples 1 to 7 and Comparative Examples 3 to 7

[0040]

[0041] Example 1

[0042] This embodiment provides a surface treatment method for an aluminum foil current collector, comprising the following steps:

[0043] S1. Prepare nitric acid with a mass concentration of 2% as a first treatment liquid, pour the first treatment liquid into an ultrasonic cleaning machine, immerse an aluminum foil with a thickness of 12 μm in the first treatment liquid, and perform ultrasonic cleaning for 1 minute;

[0044] S2. Add chromium phosphate, polymethyl acrylate, and chromium fluoride to deionized water to prepare a second treatment solution. The mass concentrations of chromium phosphate, polymethyl acrylate, and chromium fluoride in the second treatment solution are 2%, 6%, and 0.3%, respectively. Roll-coat the second treatment solution on the surface of the aluminum foil obtained in step S1 in an amount of 5 g / m 2 , and dried at 180℃ for 2min to obtain an aluminum foil current collector.

[0045] Example 2

[0046] This embodiment provides a surface treatment method for an aluminum foil current collector, comprising the following steps:

[0047] S1. Prepare nitric acid with a mass concentration of 1% as a first treatment liquid, pour the first treatment liquid into an ultrasonic cleaning machine, immerse an aluminum foil with a thickness of 12 μm in the first treatment liquid, and perform ultrasonic cleaning for 1 minute;

[0048] S2. Add chromium phosphate, polymethyl acrylate, and chromium fluoride to deionized water to prepare a second treatment solution. The mass concentrations of chromium phosphate, polymethyl acrylate, and chromium fluoride in the second treatment solution are 2%, 5%, and 0.5%, respectively. Roll-coat the second treatment solution on the surface of the aluminum foil obtained in step S1. The coating amount is 5 g / m 2 , and dried at 180°C for 2 min to obtain an aluminum foil current collector.

[0049] Example 3

[0050] This embodiment provides a surface treatment method for an aluminum foil current collector, comprising the following steps:

[0051] S1. Prepare nitric acid with a mass concentration of 2% as a first treatment liquid, pour the first treatment liquid into an ultrasonic cleaning machine, immerse an aluminum foil with a thickness of 12 μm in the first treatment liquid, and perform ultrasonic cleaning for 1 minute;

[0052] S2. Add chromium phosphate, polymethyl acrylate, and chromium fluoride to deionized water to prepare a second treatment solution. The mass concentrations of chromium phosphate, polymethyl acrylate, and chromium fluoride in the second treatment solution are 2.5%, 5%, and 1%, respectively. Roll-coat the second treatment solution on the surface of the aluminum foil obtained in step S1 in an amount of 5 g / m 2 , drying at 180°C for 2 min to obtain an aluminum foil current collector;

[0053] S3. Coating carbon on the surface of the aluminum foil current collector obtained in S2 to make a carbon-coated aluminum foil.

[0054] Example 4

[0055] This embodiment provides a surface treatment method for an aluminum foil current collector, comprising the following steps:

[0056] S1. Prepare nitric acid with a mass concentration of 5% as a first treatment liquid, pour the first treatment liquid into an ultrasonic cleaning machine, immerse an aluminum foil with a thickness of 12 μm in the first treatment liquid, and perform ultrasonic cleaning for 5 minutes;

[0057] S2. Add chromium phosphate, polymethyl acrylate, and chromium fluoride to deionized water to prepare a second treatment solution. The mass concentrations of chromium phosphate, polymethyl acrylate, and chromium fluoride in the second treatment solution are 5%, 4%, and 1%, respectively. Roll-coat the second treatment solution on the surface of the aluminum foil obtained in step S1. The coating amount is 5 g / m 2 , and dried at 180°C for 2 min to obtain an aluminum foil current collector.

[0058] Example 5

[0059] This embodiment provides a surface treatment method for an aluminum foil current collector, comprising the following steps:

[0060] S1. Prepare 7% phosphoric acid as a first treatment liquid, pour the first treatment liquid into an ultrasonic cleaning machine, immerse an aluminum foil with a thickness of 12 μm in the first treatment liquid, and perform ultrasonic cleaning for 1 minute;

[0061] S2. Add chromium nitrate, polymethyl acrylate, and chromium fluoride to deionized water to prepare a second treatment solution. The mass concentrations of chromium nitrate, polymethyl acrylate, and chromium fluoride in the second treatment solution are 1%, 2%, and 0.1%, respectively. Roll-coat the second treatment solution on the surface of the aluminum foil obtained in step S1. The coating amount is 5 g / m 2 , and dried at 180°C for 2 min to obtain an aluminum foil current collector.

[0062] Example 6

[0063] This embodiment provides a surface treatment method for an aluminum foil current collector, comprising the following steps:

[0064] S1. Prepare 8% phosphoric acid as a first treatment liquid, pour the first treatment liquid into an ultrasonic cleaning machine, immerse an aluminum foil with a thickness of 12 μm in the first treatment liquid, and perform ultrasonic cleaning for 10 minutes;

[0065] S2. Add chromium nitrate, polymethyl acrylate, and chromium fluoride to deionized water to prepare a second treatment solution. The mass concentrations of chromium nitrate, polymethyl acrylate, and chromium fluoride in the second treatment solution are 7%, 8%, and 2%, respectively. Roll-coat the second treatment solution on the surface of the aluminum foil obtained in step S1 in an amount of 2 g / m2 , and dried at 180°C for 2 min to obtain an aluminum foil current collector.

[0066] S3. Coating carbon on the surface of the aluminum foil current collector obtained in S2 to make a carbon-coated aluminum foil.

[0067] Example 7

[0068] This embodiment provides a surface treatment method for an aluminum foil current collector, comprising the following steps:

[0069] S1. Prepare nitric acid with a mass concentration of 10% as a first treatment liquid, pour the first treatment liquid into an ultrasonic cleaning machine, immerse an aluminum foil with a thickness of 12 μm in the first treatment liquid, and perform ultrasonic cleaning for 5 minutes;

[0070] S2. Add chromium phosphate, polymethyl acrylate, and chromium fluoride to deionized water to prepare a second treatment solution. The mass concentrations of chromium phosphate, polymethyl acrylate, and chromium fluoride in the second treatment solution are 10%, 15%, and 10%, respectively. Roll-coat the second treatment solution on the surface of the aluminum foil obtained in step S1 in an amount of 1 g / m 2 , and dried at 180°C for 2 min to obtain an aluminum foil current collector.

[0071] S3. Coating carbon on the surface of the aluminum foil current collector obtained in S2 to make a carbon-coated aluminum foil.

[0072] Comparative Example 1

[0073] A 12 μm thick untreated aluminum foil was used as the current collector.

[0074] Comparative Example 2

[0075] A 12μ thick, non-chemically treated aluminum foil is used and its surface is coated with carbon to make carbon-coated aluminum foil.

[0076] Comparative Example 3

[0077] This comparative example provides a method for processing an aluminum foil current collector, comprising the following steps:

[0078] S1. Prepare 0.5% nitric acid as a first treatment liquid, pour the first treatment liquid into an ultrasonic cleaning machine, immerse an aluminum foil with a thickness of 12 μm in the first treatment liquid, and perform ultrasonic cleaning for 1 minute;

[0079] S2. Add chromium phosphate, polymethyl acrylate, and chromium fluoride to deionized water to prepare a second treatment solution. The mass concentrations of chromium phosphate, polymethyl acrylate, and chromium fluoride in the second treatment solution are 10%, 1%, and 4%, respectively. Roll-coat the second treatment solution on the surface of the aluminum foil obtained in step S1 in an amount of 5 g / m 2 , and dried at 180°C for 2 min to obtain an aluminum foil current collector.

[0080] Comparative Example 4

[0081] This comparative example provides a method for processing an aluminum foil current collector, comprising the following steps:

[0082] Nitric acid with a mass concentration of 0.5% was prepared as a first treatment liquid, the first treatment liquid was poured into an ultrasonic cleaning machine, an aluminum foil with a thickness of 12 μm was immersed in the first treatment liquid, and ultrasonic cleaning was performed for 1 minute to obtain an aluminum foil current collector.

[0083] Comparative Example 5

[0084] This comparative example provides a method for processing an aluminum foil current collector, comprising the following steps:

[0085] Chromium phosphate, polymethyl acrylate, and chromium fluoride were added to deionized water to prepare a second treatment solution. The mass concentrations of chromium phosphate, polymethyl acrylate, and chromium fluoride in the second treatment solution were 10%, 1%, and 4%, respectively. The second treatment solution was roll-coated on the surface of an aluminum foil with a thickness of 12 μm. The roll-coating amount was 5 g / m 2 , and dried at 180°C for 2 min to obtain an aluminum foil current collector.

[0086] Comparative Example 6

[0087] Nitric acid, chromium phosphate, polymethyl acrylate and chromium fluoride were added to deionized water to prepare a treatment solution. The mass concentrations of nitric acid, chromium phosphate, polymethyl acrylate and chromium fluoride in the treatment solution were 0.5%, 10%, 1% and 4% respectively. The treatment solution was rolled onto the surface of 12μ thick aluminum foil at a rolling dosage of 5g / m 2 , dried at 180℃ for 2min to obtain the aluminum foil current collector.

[0088] Comparative Example 7

[0089] This comparative example provides a method for processing an aluminum foil current collector, comprising the following steps:

[0090] S1. Prepare nitric acid with a mass concentration of 2% as a first treatment liquid, pour the first treatment liquid into an ultrasonic cleaning machine, immerse an aluminum foil with a thickness of 12 μm in the first treatment liquid, and perform ultrasonic cleaning for 1 minute;

[0091] S2. Add chromium phosphate, polymethyl acrylate, and chromium fluoride to deionized water to prepare a second treatment solution. The mass concentrations of chromium phosphate, polymethyl acrylate, and chromium fluoride in the second treatment solution are 2.5%, 5%, and 1%, respectively. Roll-coat the second treatment solution on the surface of the aluminum foil obtained in step S1 in an amount of 0.5 g / m 2 , and dried at 180°C for 2 min to obtain an aluminum foil current collector.

[0092] Test Method

[0093] The current collectors of Examples 1-7 and Comparative Examples 1-7 (using the aluminum foils of Examples 3, 6, and 7 that had undergone secondary treatment but not been carbon-coated, and the aluminum foil of Comparative Example 2 that had not been carbon-coated) were tested for surface dyne value. The testing method was to use an arcotest dyne pen to draw a line about 15 cm on the surface of the aluminum foil. If there was no shrinkage within 3 seconds, the dyne value marked on the pen was reached. Switch to a higher-sized dyne pen and continue testing until the line shrinks within 3 seconds. The surface dyne value of the aluminum foil is the dyne value corresponding to the previous dyne pen. Starting with a 26# dyne pen, tests were performed sequentially. If there was no shrinkage within 3 seconds using a 40# dyne pen, switch to a 41# dyne pen. If the line shrinks within 3 seconds, the surface dyne value of the aluminum foil is recorded as 40.

[0094] The current collectors of Examples 1 to 7 and Comparative Examples 1 to 7 were selected, sealed and immersed in the same electrolyte, and placed in an environment at 85° C. The time when surface corrosion began to appear was recorded at regular intervals.

[0095] The current collectors of Examples 3, 6, 7 and Comparative Example 2 were selected, and the carbon coating layer was wiped back and forth with a dust-free cloth dipped in NMP solvent until the carbon coating layer fell off and the aluminum foil was exposed. The number of wipes was recorded.

[0096] The experimental data are shown in Table 2 below.

[0097] Table 2 Test data of examples and comparative examples

[0098]

[0099]

[0100] From Table 2 above, we can see that:

[0101] According to the dyne test results of Examples 1 to 7 and Comparative Examples 1 to 7, the aluminum foil prepared by the present invention can improve the surface dyne value, and the highest dyne value is that of Example 4, which is as high as 64 mN / m.

[0102] According to the corrosion test instructions of Examples 1 to 2, 4 to 7 and Comparative Examples 1, 3, 4, 5, 6 and 7, the aluminum foil prepared by the present invention, which is not carbon-coated, can improve the corrosion resistance of the bare aluminum foil; according to the corrosion test instructions of Example 3 and Comparative Example 2, the aluminum foil prepared by the present invention, after carbon coating, can improve the corrosion resistance compared with the ordinary aluminum foil after carbon coating.

[0103] According to the wiping test of Example 3 and Comparative Example 2, the aluminum foil prepared by the present invention has better adhesion of the carbon coating layer after carbon coating than the ordinary aluminum foil after carbon coating.

Claims

1. An aluminum foil current collector, characterized in that The aluminum foil current collector has a dyne value greater than 55 mN / m and less than 70 mN / m, and the surface treatment method of the aluminum foil current collector comprises the following steps: S1, prepare phosphoric acid or nitric acid as a first treatment liquid, immerse the aluminum foil in the first treatment liquid for cleaning, wherein the mass concentration of phosphoric acid or nitric acid in the first treatment liquid is 1-5%, and the cleaning is ultrasonic cleaning, and the ultrasonic cleaning treatment time is 0.1-10 minutes; S2. Add a chromium-containing compound, a polyacrylic acid resin, and a fluoride to a solvent to prepare a second treatment liquid, apply the second treatment liquid to the surface of the aluminum foil obtained in step S1, and dry at 100-200° C. for 0.5-10 min to obtain an aluminum foil current collector, wherein the chromium-containing compound is chromium phosphate or chromium nitrate, and the fluoride is one or more of chromium fluoride, magnesium fluoride, ammonium fluoride, and hydrofluoric acid. The mass concentration of the chromium-containing compound in the second treatment liquid is 2-5%, the mass concentration of the polyacrylic acid resin is 4-6%, and the mass concentration of the fluoride is 0.3-1%.

2. The aluminum foil current collector according to claim 1, wherein In step S2, the solvent is deionized water, and the polyacrylic acid resin is one or more of polyacrylic acid, polymethyl acrylate, and a copolymer of acrylic acid and maleic acid.

3. The aluminum foil current collector according to claim 1, wherein: In step S2, the second treatment liquid is rolled in an amount of 1-20 g / m 2 .

4. A battery pole piece, characterized in that: The invention comprises the aluminum foil current collector according to any one of claims 1 to 3, and an active material arranged on the surface of the aluminum foil current collector.

5. A lithium battery, characterized in that: It is prepared using the battery pole piece as claimed in claim 4.

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