Rolled copper foil for current collector of lithium ion battery and preparation method of rolled copper foil

Abstract

The invention belongs to the technical field of electrode materials, and particularly discloses rolled copper foil for a lithium ion battery current collector and a preparation method of the rolled copper foil. A rolled copper foil is sequentially subjected to degreasing treatment, pickling activation, roughening treatment, carbon modification treatment and anti-oxidation treatment, and the rolled copper foil for the lithium ion battery current collector is obtained. The carbon modification treatment comprises the following steps: coating the surface of the roughened rolled copper foil with a carbon material dispersion liquid, and carrying out curing treatment to complete the carbon modification treatment. According to the method, the rolled copper foil is subjected to multi-step treatment, so that the surface roughness of the rolled copper foil is improved, the attachment of a battery negative electrode active material on the copper foil is facilitated, and the stability of an electrode is improved; and the conductivity of the high-rolled copper foil is also improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrode materials, and particularly relates to a calendered copper foil for lithium ion battery current collector and a preparation method thereof. BACKGROUND

[0002] As the core technology in the current energy storage field, the performance improvement of lithium ion battery is highly dependent on the innovation breakthrough of key materials. As the core component of carrying active materials and conducting electrons, the performance of the current collector directly affects the energy density, power characteristics and cycle life of the battery. The electrolytic copper foil or the calendered copper foil is generally used as the current collector of the negative electrode of the lithium ion battery. The electrolytic copper foil has good electrical conductivity and suitable surface roughness. However, with the rapid development of battery technology towards high energy density, fast charging and long cycle, the inherent defects of the electrolytic copper foil are increasingly highlighted. Firstly, the copper foil prepared by the electrolysis process has obvious anisotropy, and the difference between the longitudinal tensile strength and the transverse tensile strength is significant. In the process of rolling the battery electrode, stress concentration is easily caused to lead to fracture, especially when the thickness of the foil is reduced to less than 6 microns, the yield rate of the good product is obviously decreased. Secondly, the surface roughness of the electrolytic copper foil is not suitable for the matching with the active material. When the volume change of the high-nickel positive electrode or the silicon-based negative electrode is too large during the charging and discharging process, the coating is easily peeled off. Thirdly, the crystal structure of the electrolytic copper foil has a preferred orientation of crystal face, which easily causes the formation of dendritic crystals penetrating the separator during the deposition of lithium ions.

[0003] Compared with the electrolytic copper foil, the calendered copper foil as the electrode current collector has excellent mechanical properties and electrical conductivity. The fibrous grain structure of the calendered copper foil gives higher ductility and bending resistance, and can withstand repeated deformation in the dynamic charging and discharging process without cracking, and is particularly suitable for flexible battery design. The surface smoothness of the calendered copper foil is better than that of the electrolytic copper foil, which can reduce the interface impedance and improve the efficiency of electron transmission. The purity of the copper is higher, the electrical conductivity is more excellent, and the thickness uniformity is better, which is beneficial to the manufacture of high energy density batteries.

[0004] However, the surface of the calendered copper foil is smooth and lacks porous structure, which causes the adhesion of the active material (such as graphite, silicon) to be weaker than that of the electrolytic copper foil, and there is a problem that the active material is easy to fall off. At the same time, in order to meet the manufacture of high energy density batteries, the electrical conductivity also needs to be further improved. SUMMARY

[0005] Therefore, the present application provides a calendered copper foil for lithium ion battery current collector and a preparation method thereof, to solve the problems that the roughness of the calendered copper foil is too small, the adhesion with the active component is poor, and the electrical conductivity also needs to be further improved.

[0006] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0007] A preparation method of a calendered copper foil for lithium ion battery current collector, comprising the following steps:

[0008] The calendered copper foil is sequentially subjected to degreasing treatment, acid pickling activation, roughening treatment, carbon modification treatment and oxidation resistance treatment to obtain a calendered copper foil for lithium ion battery current collector;

[0009] The step of carbon modification treatment comprises: coating a carbon material dispersion liquid on the surface of the calendered copper foil after roughening treatment, and performing solidification treatment to complete the carbon modification treatment.

[0010] Preferably, the thickness of the calendered copper foil is 8-20 μm.

[0011] Preferably, the degreasing treatment comprises sequentially performed alkaline degreasing and electrolytic degreasing.

[0012] Preferably, the degreasing agent in the alkaline degreasing is a mixture of sodium hydroxide solution and anionic surfactant; the concentration of sodium hydroxide in the degreasing agent is 25-30 g / L, and the mass concentration of anionic surfactant is 0.1-0.3%.

[0013] The temperature of the alkaline degreasing is 60-70°C, and the time of the alkaline degreasing is ≥0.5 min.

[0014] Preferably, the electrolyte for the electrolytic degreasing is a mixed solution of sodium hydroxide and sodium carbonate.

[0015] The concentration of sodium hydroxide in the electrolyte is 25-30 g / L, and the concentration of sodium carbonate is 25-35 g / L.

[0016] The current density of the electrolytic degreasing is 6-8 A / dm 2 , the temperature is 50-60°C, and the time is 10-100 s.

[0017] Preferably, the step of acid pickling activation comprises immersing the calendered copper foil after degreasing treatment in an acid solution to complete the acid pickling activation.

[0018] The acid solution comprises sulfuric acid solution and hydrochloric acid solution; the mass concentration of the acid solution is 5-20%.

[0019] The time of immersing in the acid solution is 1-2 min.

[0020] Preferably, the concentration of ferric chloride in the roughening solution of the roughening treatment is 80-150 g / L, the concentration of hydrochloric acid is 30-50 g / L, and the concentration of gum arabic is 0.005-0.02 g / L.

[0021] The time of the roughening treatment is 10-100 s.

[0022] Preferably, the carbon material in the carbon material dispersion liquid comprises graphene dispersion liquid and carbon nanotube dispersion liquid.

[0023] Preferably, the coating amount of the carbon material dispersion liquid is 0.05 to 3 mg / cm2 in terms of carbon material. 2 ;

[0024] The temperature of the curing treatment is 300 to 400 DEG C, the time of the curing treatment is 0.5 to 1.5 h, and the atmosphere of the curing treatment is an inert atmosphere.

[0025] Another object of the present application is to provide a calendered copper foil for lithium ion battery current collector prepared by the above preparation method.

[0026] Via the technical solution described above, compared with the prior art, the present application has the following beneficial effects:

[0027] 1. The present application improves the surface roughness of the calendered copper foil through multi-step processing, which is beneficial to the adhesion of the battery negative active material on the copper foil and improves the stability of the electrode.

[0028] 2. The present application performs degreasing treatment, which can remove the surface contaminants of the calendered copper foil and improve the surface energy and wettability. The pickling activation can avoid the alkaline residue brought by the degreasing treatment and remove the oxide layer; the surface of the calendered copper foil is activated, which forms uniform corrosion in the roughening treatment and avoids the problem of uneven roughness. The roughening treatment can form micro-nano pores on the surface of the calendered copper foil, which can improve the roughness of the calendered copper foil and improve the adhesion with the negative active component; it can also play a role in inhibiting lithium dendrites. The carbon material in the carbon modification treatment can form a barb effect after solidification in the surface micropores of the calendered copper foil and be attached to the surface of the calendered copper foil through mechanical interlocking; a copper-carbon interface will also be formed under the heating condition in the solidification process, which enhances the bonding of the carbon material, and the carbon modification treatment can also significantly improve the conductivity of the calendered copper foil. DETAILED DESCRIPTION

[0029] The present application provides a preparation method of a calendered copper foil for lithium ion battery current collector, which comprises the following steps:

[0030] The calendered copper foil is sequentially subjected to degreasing treatment, pickling activation, roughening treatment, carbon modification treatment and oxidation resistance treatment to obtain a calendered copper foil for lithium ion battery current collector.

[0031] In the present application, the step of carbon modification treatment comprises: coating a carbon material dispersion liquid on the surface of the calendered copper foil after the roughening treatment, and performing curing treatment to complete the carbon modification treatment.

[0032] In the present application, the thickness of the calendered copper foil is 8 to 20 μm, and specifically can be 10 μm, 12 μm, 14 μm, 15 μm, 16 μm or 18 μm. The calendered copper foil described in the present application is preferably a battery-grade calendered copper foil.

[0033] In the present application, the degreasing treatment includes alkaline degreasing and electrolytic degreasing performed in sequence.

[0034] In the present application, the degreasing agent in the alkaline degreasing is a mixture of sodium hydroxide solution and anionic surfactant; the concentration of sodium hydroxide in the degreasing agent is 25-30 g / L, specifically 26 g / L, 27 g / L, 28 g / L, or 29 g / L; the mass concentration of anionic surfactant is 0.1-0.3%, specifically 0.12%, 0.15%, 0.18%, 0.2%, 0.22%, 0.25%, or 0.28%. The anionic surfactant includes one or more of sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, and sodium fatty alcohol polyoxyethylene ether sulfate.

[0035] In the present application, the temperature of the alkaline degreasing is 60-70℃, specifically 62℃, 64℃, 65℃, 66℃, or 68℃; the time of alkaline degreasing is ≥0.5 min, specifically 0.6 min, 0.8 min, 1 min, 2 min, 4 min, 5 min, or 6 min.

[0036] In the present application, the electrolyte of the electrolytic degreasing is a mixed solution of sodium hydroxide and sodium carbonate.

[0037] In the present application, the concentration of sodium hydroxide in the electrolyte is 25-30 g / L, specifically 26 g / L, 27 g / L, 28 g / L, or 29 g / L; the concentration of sodium carbonate is 25-35 g / L, specifically 26 g / L, 28 g / L, 30 g / L, 32 g / L, or 34 g / L.

[0038] In the present application, the current density of the electrolytic degreasing is 6-8 A / dm 2 , specifically 6.2 A / dm 2 , 6.5 A / dm 2 , 6.8 A / dm 2 , 7 A / dm 2 , 7.2 A / dm 2 , 7.5 A / dm 2 , or 7.8 A / dm 2 ; the temperature is 50-60℃, specifically 52℃, 54℃, 55℃, 56℃, or 58℃; the time is 10-100 s, specifically 20 s, 30 s, 40 s, 50 s, 60 s, 70 s, 80 s, or 90 s.

[0039] In the present application, the acid pickling activation step is to immerse the calendered copper foil after the degreasing treatment into an acid solution to complete the acid pickling activation.

[0040] In the present application, the acid solution includes sulfuric acid solution and hydrochloric acid solution; the mass concentration of the acid solution is 5-20%, and specifically can be 6%, 8%, 10%, 12%, 14%, 15%, 16%, 18%.

[0041] In the present application, the time of immersing in the acid solution is 1-2 min, and specifically can be 1.2 min, 1.4 min, 1.5 min, 1.6 min, 1.8 min.

[0042] In the present application, the concentration of ferric chloride in the roughening solution for the roughening treatment is 80-150 g / L, and specifically can be 90 g / L, 100 g / L, 110 g / L, 120 g / L, 130 g / L, 140 g / L; the concentration of hydrochloric acid is 30-50 g / L, and specifically can be 32 g / L, 35 g / L, 38 g / L, 40 g / L, 42 g / L, 45 g / L, 48 g / L; the concentration of gum arabic is 0.005-0.02 g / L, and specifically can be 0.008 g / L, 0.01 g / L, 0.012 g / L, 0.015 g / L, 0.018 g / L.

[0043] In the present application, the time of the roughening treatment is 10-100 s, and specifically can be 20 s, 30 s, 40 s, 50 s, 60 s, 70 s, 80 s, 90 s.

[0044] In the present application, the carbon material in the carbon material dispersion liquid includes graphene dispersion liquid and carbon nanotube dispersion liquid.

[0045] In the present application, the coating amount of the carbon material dispersion liquid is 0.05-3 mg / cm 2 of carbon material, and specifically can be 0.1 mg / cm 2 , 0.2 mg / cm 2 , 0.5 mg / cm 2 , 0.8 mg / cm 2 , 1 mg / cm 2 , 1.5 mg / cm 2 , 2 mg / cm 2 , 2.5 mg / cm 2 .

[0046] In the present application, the temperature of the solidification treatment is 300-400℃, and specifically can be 320℃, 340℃, 350℃, 360℃, 380℃; the time of the solidification treatment is 0.5-1.5 h, and specifically can be 0.6 h, 0.8 h, 1 h, 1.2 h, 1.4 h; the atmosphere of the solidification treatment is inert atmosphere.

[0047] In the present application, the antioxidant treatment is to form a passivation film on the surface of the rolled copper foil by using benzotriazole.

[0048] The application further provides the calendered copper foil for lithium ion battery current collectors prepared by the preparation method.

[0049] The technical solutions in the embodiments of the application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0050] The calendered copper foils adopted in the embodiments of the application are all common commercially available battery-grade calendered copper foils (divided into two models of 12 μm and 18 μm)

[0051] Embodiment 1

[0052] The calendered copper foil (12 μm) is immersed in a mixed solution of sodium hydroxide and sodium dodecyl benzene sulfonate (the mass concentration of sodium hydroxide is 25 g / L, and the mass concentration of sodium dodecyl benzene sulfonate is 0.2%), the temperature of the alkali degreasing agent is controlled to be 60 ℃ for 2 min, then the calendered copper foil is placed in an electrolyte (the concentration of sodium hydroxide is 25 g / L, and the concentration of sodium carbonate is 30 g / L) at 60 ℃, the calendered copper foil is kept connected with a negative electrode of a power supply, a 316L stainless steel plate is kept connected with a positive electrode of the power supply, the electrode distance is 50 mm, and the current density is controlled to be 8 A / dm 2 , the treatment time is 30 s, and after being taken out, the calendered copper foil is washed until the pH value of washing water is neutral, and the degreasing treatment of the calendered copper foil is completed.

[0053] The calendered copper foil after the degreasing treatment is immersed in a 10% sulfuric acid solution for 1 min, taken out and washed, the pickling and activation treatment is completed, then the calendered copper foil is placed in a roughening solution (the concentration of ferric chloride is 80 g / L, the concentration of hydrochloric acid is 35 g / L, and the concentration of gum arabic is 0.01 g / L) for roughening treatment for 30 s, the calendered copper foil after roughening is taken out and washed, and the calendered copper foil has fine micropores on the surface.

[0054] The graphene dispersion liquid is coated on the surface of the calendered copper foil after roughening, the coating amount of the graphene is 2 mg / cm 2 , then the calendered copper foil is cured at 350 ℃ for 1 h under a nitrogen atmosphere, after the curing is completed, a passivation film is formed on the surface of the calendered copper foil by using benzotriazole, and the calendered copper foil for lithium ion battery current collectors is obtained.

[0055] According to detection according to GB / T 36146-2018, the tensile strength is 452 MPa, and the elongation after fracture is 1.8%, and the calendered copper foil has good mechanical properties.

[0056] Embodiment 2

[0057] The rolled copper foil (12 μm) is immersed in a mixed solution of sodium hydroxide and sodium dodecyl benzene sulfonate (the mass concentration of sodium hydroxide is 26 g / L, and the mass concentration of sodium dodecyl benzene sulfonate is 0.1%), the temperature of the alkaline degreasing agent is controlled to be 60°C for 2 min, then the rolled copper foil is placed in an electrolyte (the concentration of sodium hydroxide is 30 g / L, and the concentration of sodium carbonate is 28 g / L) at 60°C, connected with the negative pole of a power supply, a 316L stainless steel plate is connected with the positive pole of the power supply, the pole distance is 50 mm, and the current density is controlled to be 6 A / dm 2 , the treatment time is 50 s, and after being taken out, the rolled copper foil is washed until the pH value of the washing water is neutral, and the degreasing treatment of the rolled copper foil is completed.

[0058] The degreased rolled copper foil is immersed in a 10% sulfuric acid solution for 1 min, taken out and washed, and the pickling activation treatment is completed; then the rolled copper foil is placed in a roughening solution (the concentration of ferric chloride is 100 g / L, the concentration of hydrochloric acid is 30 g / L, and the concentration of gum arabic is 0.01 g / L) for roughening treatment for 20 s, taken out and washed to obtain the roughened rolled copper foil, and there are fine micropores on the surface of the rolled copper foil.

[0059] The graphene dispersion liquid is coated on the surface of the roughened rolled copper foil, the coating amount of the graphene is 2 mg / cm 2 , then the rolled copper foil is cured at 400°C for 1 h under a nitrogen atmosphere, and after the curing is completed, a passivation film is formed on the surface of the rolled copper foil by using benzotriazole, and the rolled copper foil for lithium ion battery current collector is obtained.

[0060] According to the detection according to GB / T 36146-2018, the tensile strength is 446 MPa, and the elongation after fracture is 1.8%, and the mechanical properties are good.

[0061] Example 3

[0062] The rolled copper foil (12 μm) is immersed in a mixed solution of sodium hydroxide and sodium dodecyl benzene sulfonate (the mass concentration of sodium hydroxide is 30 g / L, and the mass concentration of sodium dodecyl benzene sulfonate is 0.1%), the temperature of the alkaline degreasing agent is controlled to be 70°C for 0.5 min, then the rolled copper foil is placed in an electrolyte (the concentration of sodium hydroxide is 25 g / L, and the concentration of sodium carbonate is 25 g / L) at 50°C, connected with the negative pole of a power supply, a 316L stainless steel plate is connected with the positive pole of the power supply, the pole distance is 50 mm, and the current density is controlled to be 7 A / dm 2 , the treatment time is 10 s, and after being taken out, the rolled copper foil is washed until the pH value of the washing water is neutral, and the degreasing treatment of the rolled copper foil is completed.

[0063] The rolled copper foil after degreasing treatment is immersed in a 10% sulfuric acid solution for 2 min, taken out and washed to complete the pickling activation treatment; then it is placed in a roughening solution (the concentration of ferric chloride is 150 g / L, the concentration of hydrochloric acid is 30 g / L, and the concentration of gum arabic is 0.005 g / L) for roughening treatment for 10 s, taken out and washed to obtain the roughened rolled copper foil, and there are fine micropores on the surface of the rolled copper foil.

[0064] The carbon nanotube dispersion liquid is coated on the surface of the roughened rolled copper foil, and the coating amount of the carbon nanotube is 0.05 mg / cm 2 Then, under a nitrogen atmosphere, it is cured at 300°C for 1.5 h, and after curing, a passivation film is formed on the surface of the rolled copper foil by using benzotriazole to obtain a rolled copper foil for lithium ion battery current collector.

[0065] According to GB / T 36146-2018, the tensile strength is 449 MPa, and the elongation after fracture is 1.7%, and the mechanical properties are good.

[0066] Example 4

[0067] The rolled copper foil (18 μm) is immersed in a mixed solution of sodium hydroxide and sodium dodecylbenzenesulfonate (the mass concentration of sodium hydroxide is 28 g / L, and the mass concentration of sodium dodecylbenzenesulfonate is 0.3%), and the temperature of the alkaline degreasing agent is controlled at 70°C for 1 min, and then it is placed in an electrolyte (the concentration of sodium hydroxide is 30 g / L, and the concentration of sodium carbonate is 25 g / L) at 60°C, and the negative electrode of the power supply is connected, the positive electrode of the power supply is connected with a 316L stainless steel plate, the electrode distance is 50 mm, and the current density is controlled at 8 A / dm 2 for 20 s, and after taking out, it is washed until the pH value of the washing water is neutral to complete the degreasing treatment of the rolled copper foil.

[0068] The rolled copper foil after degreasing treatment is immersed in a 10% sulfuric acid solution for 1 min, taken out and washed to complete the pickling activation treatment; then it is placed in a roughening solution (the concentration of ferric chloride is 120 g / L, the concentration of hydrochloric acid is 50 g / L, and the concentration of gum arabic is 0.02 g / L) for roughening treatment for 60 s, taken out and washed to obtain the roughened rolled copper foil, and there are fine micropores on the surface of the rolled copper foil.

[0069] The carbon nanotube dispersion liquid is coated on the surface of the roughened rolled copper foil, and the coating amount of the carbon nanotube is 0.08 mg / cm 2 Then, under a nitrogen atmosphere, it is cured at 300°C for 1 h, and after curing, a passivation film is formed on the surface of the rolled copper foil by using benzotriazole to obtain a rolled copper foil for lithium ion battery current collector.

[0070] According to GB / T 36146-2018, the tensile strength is 483 MPa, the elongation at break is 1.9%, and the mechanical properties are good.

[0071] Comparative Example 1

[0072] The untreated calendered copper foil of Example 1 is used as Comparative Example 1.

[0073] The adhesion of Example 1 and Comparative Example 1 is tested respectively. The copper foil coated with negative material is fixed on the substrate, and the 180° peeling test method is used. The peeling force is measured by using the Instron universal material testing machine at a constant speed. The test results show that under the same test conditions, the test results of the calendered copper foil of Example 1 are improved by 35.5% compared with Comparative Example 1. After assembling the battery, the capacity retention rate is tested 200 times under the condition of 1C. The capacity retention rate of Example 1 is improved by 5.6% compared with Comparative Example 1, reaching 95.2%. The calendered copper foil treatment method disclosed in the application is beneficial to improve the stability of lithium ion batteries.

[0074] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0075] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing rolled copper foil for lithium-ion battery current collectors, characterized in that, Includes the following steps: The rolled copper foil is subjected to degreasing, pickling and activation, roughening, carbon modification and anti-oxidation treatment in sequence to obtain rolled copper foil for lithium-ion battery current collectors. The carbon modification process includes: coating a carbon material dispersion onto the surface of a roughened rolled copper foil, followed by curing to complete the carbon modification process.

2. The method for preparing rolled copper foil for lithium-ion battery current collectors according to claim 1, characterized in that, The thickness of the rolled copper foil is 8–20 μm.

3. The method for preparing rolled copper foil for lithium-ion battery current collectors according to claim 2, characterized in that, The degreasing process includes sequential alkaline washing and electrolytic degreasing.

4. The method for preparing rolled copper foil for lithium-ion battery current collectors according to claim 3, characterized in that, The degreasing agent in the alkaline washing degreasing is a mixture of sodium hydroxide solution and anionic surfactant; the concentration of sodium hydroxide in the degreasing agent is 25-30 g / L, and the mass concentration of the anionic surfactant is 0.1-0.3%; The alkaline washing and degreasing temperature is 60-70℃, and the alkaline washing and degreasing time is ≥0.5min.

5. The method for preparing rolled copper foil for lithium-ion battery current collectors according to claim 4, characterized in that, The electrolyte for the electrolytic degreasing is a mixed solution of sodium hydroxide and sodium carbonate; The concentration of sodium hydroxide in the electrolyte is 25-30 g / L, and the concentration of sodium carbonate is 25-35 g / L. The current density for the electrolytic degreasing is 6–8 A / dm³. 2 The temperature is 50-60℃ and the time is 10-100s.

6. A method for preparing rolled copper foil for lithium-ion battery current collectors according to any one of claims 1 to 5, characterized in that, The pickling and activation step involves immersing the degreased rolled copper foil in an acid solution to complete the pickling and activation process. The acid solution includes sulfuric acid solution and hydrochloric acid solution; the mass concentration of the acid solution is 5-20%; The immersion time in the acid solution is 1 to 2 minutes.

7. The method for preparing rolled copper foil for lithium-ion battery current collectors according to claim 6, characterized in that, The concentration of ferric chloride in the roughening solution of the roughening treatment is 80-150 g / L, the concentration of hydrochloric acid is 30-50 g / L, and the concentration of gum arabic is 0.005-0.02 g / L. The roughening process takes 10 to 100 seconds.

8. The method for preparing rolled copper foil for lithium-ion battery current collectors according to claim 7, characterized in that, The carbon materials in the carbon material dispersion include graphene dispersion and carbon nanotube dispersion.

9. A method for preparing rolled copper foil for lithium-ion battery current collectors according to claim 8, characterized in that, The coating amount of the carbon material dispersion is 0.05–3 mg / cm³ based on the carbon material content. 2 ; The curing temperature is 300–400°C, the curing time is 0.5–1.5 h, and the curing atmosphere is an inert atmosphere.

10. The rolled copper foil for lithium-ion battery current collector prepared by the preparation method according to any one of claims 1 to 9.