Composite copper foil and manufacturing method and application thereof

Abstract

The invention belongs to the technical field of battery materials, and provides a composite copper foil and a manufacturing method and application thereof.The composite copper foil comprises a copper foil base body and further comprises a moisture-resistant and corrosion-resistant conductive coating arranged on the surface of the copper foil base body, and the moisture-resistant and corrosion-resistant conductive coating comprises an organic conductive polymer. By arranging the specific organic conductive polymer film layer on the copper foil, the characteristics that the film layer is relatively uniform and compact and can still keep conductivity when being formed by organic conductive polymerization are utilized, so that the water-proof, moisture-proof and corrosion-proof effects are achieved. By using the composite copper foil, temperature and humidity control requirements in storage and application processes can be eliminated, and environmental humidity and moisture do not need to be considered.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of battery materials, and relates to a composite copper foil and a manufacturing method and use thereof. BACKGROUND

[0002] As an important carrier of lithium-ion battery negative electrodes, the quality of copper foil is directly related to the performance and service life of the battery. The copper foil on the current market is usually micron-thick, and can be divided into electrolytic copper foil and calendered copper foil according to different production processes. Among them, electrolytic copper foil has been widely used in the field of lithium-ion batteries due to its lower production cost and strong adaptability. However, electrolytic copper foil has the problem of difference between the rough surface and the smooth surface, that is, one side is relatively smooth (smooth surface), and the other side presents a relatively rough state (rough surface). This difference not only affects the overall uniformity of the copper foil, but also challenges the corrosion resistance of the copper foil.

[0003] Specifically, the rough surface of the electrolytic copper foil often exhibits poor corrosion resistance due to the irregularity of its surface structure and high roughness. In actual application, when the copper foil is exposed to air or other environments containing oxidizing agents, an oxide layer or a corrosion layer is easily formed on the rough surface. These oxides or corrosion products not only change the physical properties of the copper foil, but also significantly increase its surface resistance. As the surface resistance increases, the efficiency of electron conduction decreases, which directly affects the overall performance of the lithium-ion battery and shortens its service life.

[0004] In addition to affecting the electrochemical performance of the battery, the oxide layer or the corrosion layer on the surface of the copper foil also has a negative impact on its processing performance. In the manufacturing process of lithium-ion batteries, negative active material slurry needs to be uniformly coated on the copper foil, and through drying, pressing and other process steps, a complete electrode sheet is formed. If there is an oxide layer or a corrosion layer on the surface of the copper foil, it will seriously affect the adhesion and leveling performance of the slurry. For example, the presence of the oxide layer may cause the slurry to fail to fully wet the surface of the copper foil, resulting in uneven coating and affecting the quality and consistency of the electrode.

[0005] In order to solve the above problems, improvements need to be made to the copper foil. In terms of production, researchers have tried various methods to optimize the preparation process of electrolytic copper foil. For example, by adjusting the electrolyte composition, controlling the current density and optimizing the post-treatment process, the smoothness and flatness of the surface of the copper foil can be improved to some extent. However, although these improvement measures can partially alleviate the problem of roughness of the rough surface, they cannot completely eliminate the difference between the rough surface and the smooth surface. In terms of improvement of the anti-oxidation and anti-corrosion of the surface of the copper foil, a conductive carbon layer is often formed on the surface of the copper foil, but the conductive carbon material is easy to accumulate and form a loose and porous structure, and these gaps will absorb moisture and accelerate the corrosion process in a high humidity environment, so the effect is not ideal.

[0006] In addition to improving the production of copper foil, strict control of the storage conditions of copper foil and the environmental humidity during the production of electrodes is also an important means to prevent the oxidation and corrosion of copper foil. In actual operation, it is generally required to store the copper foil in a low temperature and low humidity environment. The recommended storage temperature is generally 10-25°C, and the long-term storage needs to be controlled at 23±5°C, and the relative humidity needs to be maintained at 45%±20%, generally in a dry room below 40% to reduce the influence of water in the air on the copper foil. At the same time, high-efficiency air purification systems and dehumidification equipment should be equipped in the production workshop to maintain constant temperature and humidity conditions; before coating, the copper foil also needs to be preheated to remove the trace amount of water adsorbed on the surface, to ensure that the slurry can be uniformly coated on the surface thereof. Although these environmental management measures can effectively reduce the risk of oxidation and corrosion of copper foil, the process flow required for implementation in large-scale industrial production is complex, and it is difficult to operate, which requires continuous investment of a large amount of resources for maintenance and monitoring.

[0007] In summary, although the existing technical means can alleviate the problem of oxidation and corrosion of the surface of copper foil to some extent, there are still many challenges. In particular, in improving the anti-oxidation performance of the surface of copper foil, especially the matte surface, the existing method cannot fully meet the needs of industrial production. Therefore, it is urgent to develop new technical routes to take into account both economy and operability. SUMMARY

[0008] In view of the problems in the prior art, the purpose of the present application is to provide a composite copper foil and a manufacturing method and use thereof, the composite copper foil comprising a copper foil substrate, further comprising an anti-humidity and corrosion-resistant conductive coating layer provided on the surface of the copper foil substrate, the anti-humidity and corrosion-resistant conductive coating layer comprising an organic conductive polymer. The present application sets a specific organic conductive polymer film layer on the copper foil, which takes advantage of the characteristics of the organic conductive polymer film layer being relatively uniform and dense and still maintaining the conductivity, so as to play the role of waterproof, moisture-proof and corrosion-resistant. The composite copper foil provided with the coating layer can eliminate the requirement for temperature and humidity control during storage and application, and does not need to consider the environmental humidity and moisture. At the same time, the coating layer can increase the adhesion to the copper foil substrate, has good stability, and has good conductivity without affecting the effect when used as a current collector.

[0009] To achieve this purpose, the present application adopts the following technical solutions:

[0010] In a first aspect, the present application provides a composite copper foil, the composite copper foil comprising a copper foil substrate, further comprising an anti-humidity and corrosion-resistant conductive coating layer provided on the surface of the copper foil substrate, the anti-humidity and corrosion-resistant conductive coating layer comprising an organic conductive polymer.

[0011] The present invention applies a specific organic conductive polymer thin film layer to copper foil, leveraging the uniformity and density of the organic conductive polymer film while maintaining electrical conductivity. This provides waterproof, moisture-proof, and corrosion-resistant properties. Composite copper foil coated with this coating eliminates the need for temperature and humidity control during storage and application, eliminating the need to consider ambient humidity and moisture. The coating also enhances adhesion to the copper foil substrate, provides excellent stability, and offers excellent electrical conductivity without affecting its performance as a current collector.

[0012] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following technical solutions, the technical objectives and beneficial effects of the present invention can be better achieved and realized.

[0013] As a preferred technical solution of the present invention, the thickness of the moisture-resistant and corrosion-resistant conductive coating is 1 to 100 μm, for example, 1 μm, 3 μm, 5 μm, 8 μm, 10 μm, 13 μm, 15 μm, 18 μm, 20 μm, 23 μm, 25 μm, 28 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or 100 μm, etc., preferably 1 to 30 μm, but is not limited to the listed values, and other values ​​not listed within the above numerical range are also applicable.

[0014] In the present invention, the moisture-resistant and corrosion-resistant conductive coating will significantly affect the conductivity, and too great a thickness will significantly increase the resistance.

[0015] As a preferred technical solution of the present invention, the organic conductive polymer film layer includes at least one of polyacetylene, polyaniline, polypyrrole, polythiophene, polyparaphenylene vinylene, polyparaphenylene or polyphenylene sulfide.

[0016] Preferably, the molecular weights of the polyacetylene and polypyrrole are affected by the polymerization method and conditions, and should be reasonably adjusted according to actual conditions and needs.

[0017] Preferably, the weight average molecular weight of the polyaniline is in the range of 50,000 to 80,000, for example, 50,000, 52,000, 55,000, 58,000, 60,000, 62,000, 65,000, 68,000, 70,000, 72,000, 75,000, 78,000 or 80,000.

[0018] Preferably, the weight average molecular weight of the polythiophene is 5000-80000, for example, 5000, 8000, 10000, 15000, 20000, 30000, 40000, 50000, 60000, 70000 or 80000.

[0019] Preferably, the poly-p-phenylenevinylene has a ratio of weight average molecular weight to number average molecular weight of 1.5 to 3.2, such as 1.5, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3, or 3.2, etc.

[0020] Preferably, the polyphenylene sulfide has a number average molecular weight of 5000 to 40000, such as 5000, 8000, 10000, 15000, 20000, 25000, 30000, 35000, or 40000, etc.

[0021] As a preferred technical solution of the present application, the polythiophene includes a poly(3-hexylthiophene) or a poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate complex. The poly(3-hexylthiophene) is P3HT, and the poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate complex is PEDOT:PSS.

[0022] As a preferred technical solution of the present application, the moisture-resistant and corrosion-resistant conductive coating further includes conductive carbon.

[0023] Preferably, the conductive carbon includes graphene and / or carbon nanotubes.

[0024] Further, in order to ensure or improve the conductivity of the thin film layer formed by the organic polymer, a mixture thin film layer of the organic conductive polymer and the conductive carbon can be formed using the conductive carbon, in which the organic polymer forms a continuous phase thin film, and the conductive carbon forms a conductive network as a dispersed phase, effectively improving the conductivity of the mixture thin film layer.

[0025] As a preferred technical solution of the present application, the conductive carbon includes graphene and carbon nanotubes in a mass ratio of (0.01 to 1):1, such as 0.01:1, 0.03:1, 0.05:1, 0.08:1, 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, or 1:1, etc., but not limited to the listed values, and other values not listed in the above range are also applicable.

[0026] In the present application, by adjusting the ratio of graphene to carbon nanotubes, the optimization effect on the conductivity can be affected, and under the optimal ratio, one-dimensional and two-dimensional conductive carbons construct the optimal conductive network.

[0027] As a preferred technical solution of the present application, the anti-wet and corrosion-resistant conductive coating comprises the organic conductive polymer and the conductive carbon in a mass ratio of (100-x):x, x=0.1-99, for example, 1:99, 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, 90:10, 92:8, 95:5, 96:4, 97:3, 98:2, 99:1, 99.5:0.5, 99.8:0.2, or 99.9:0.1, etc., but not limited to the listed values, and other values not listed in the above value range are also applicable.

[0028] In the present application, the content of the organic conductive polymer in the anti-wet and corrosion-resistant conductive coating affects the corrosion resistance, and within a certain proportion, the higher the organic conductive polymer, the better the corrosion resistance.

[0029] As a preferred technical solution of the present application, the copper foil substrate has opposite rough and smooth surfaces, and the anti-wet and corrosion-resistant conductive coating is arranged on the rough surface.

[0030] As a preferred technical solution of the present application, the resistivity of the composite copper foil is ≤1×10 -4 Ω·cm.

[0031] In a second aspect, the present application also provides a manufacturing method of the composite copper foil of the first aspect, the manufacturing method comprising: preparing a copper foil substrate, preparing a coating solution containing an organic conductive polymer or further containing conductive carbon, coating the coating solution on the surface of the copper foil substrate by micro-gravure roll coating, and after drying, forming an anti-wet and corrosion-resistant conductive coating to obtain the composite copper foil.

[0032] Preferably, the speed of the micro-gravure roll coating is 1-100 m / min, for example, 1 m / min, 5 m / min, 8 m / min, 10 m / min, 20 m / min, 30 m / min, 40 m / min, 50 m / min, 60 m / min, 70 m / min, 80 m / min, 90 m / min, or 100 m / min, etc., but not limited to the listed values, and other values not listed in the above value range are also applicable. The thickness deviation of the coating formed by the micro-gravure roll coating should be controlled to be <±5% to meet the uniformity of coating.

[0033] Preferably, the drying mode comprises hot air drying and / or infrared heating, and the drying temperature is 80-150℃, for example, 80℃, 90℃, 100℃, 110℃, 120℃, 130℃, 140℃, or 150℃, etc., but not limited to the listed values, and other values not listed in the above value range are also applicable.

[0034] As a preferred technical scheme of the present application, the coating solution further comprises conductive carbon.

[0035] Preferably, the conductive carbon is mixed with an aqueous dispersant and water in advance, and after homogenization by a double-planet or high-speed disperser, the mixture is ground and dispersed by a sand mill to obtain a dispersion liquid A, which is stored after stirring and uniformity removal for standby use; the organic conductive polymer is prepared into a solution B with an organic solvent, and the dispersion liquid A and the solution B are mixed to obtain the coating solution.

[0036] Preferably, the aqueous dispersant comprises SDBS (sodium dodecyl benzene sulfonate).

[0037] Preferably, the absolute value of Zeta potential of the dispersion liquid A is greater than 30 mV to maintain the dispersion stability.

[0038] Preferably, the copper foil substrate is subjected to a surface plasma activation treatment in advance.

[0039] Preferably, when the moisture-resistant and corrosion-resistant conductive coating is an organic conductive polymer thin film layer and does not contain conductive carbon, the manufacturing method of the moisture-resistant and corrosion-resistant conductive coating can further adopt a chemical vapor deposition (CVD) method.

[0040] In a third aspect, the present application provides a negative electrode tab, which contains the composite copper foil of the second aspect as a current collector, and an active layer of the negative electrode tab is arranged on the surface of the moisture-resistant and corrosion-resistant conductive coating in the composite copper foil.

[0041] In a fourth aspect, the present application provides a battery containing the negative electrode tab of the third aspect.

[0042] Compared with the prior art, the present application has at least the following beneficial effects:

[0043] By arranging a film layer containing an organic conductive polymer on the copper foil, the present application takes advantage of the characteristics of the organic conductive polymer, i.e., the thin film layer formed by the organic conductive polymer is relatively uniform and dense and still maintains the conductivity, so that the film layer plays a role in waterproofing, moisture-proofing and corrosion-proofing. The composite copper foil provided with the coating layer can eliminate the requirements for temperature and humidity control during storage and application, and does not need to consider the environmental humidity and moisture. At the same time, the coating layer can increase the adhesion to the copper foil substrate, has good stability, and has good conductivity without affecting the effect when used as a current collector.

[0044] Further, in order to ensure or improve the conductivity of the thin film layer formed by the organic polymer, the present application can use conductive carbon to form a mixture thin film layer of the organic conductive polymer and the conductive carbon, in which the organic polymer forms a continuous phase thin film, and the conductive carbon forms a conductive network as a dispersed phase, effectively improving the conductivity of the mixture thin film layer. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 Schematic diagram of the structure of the composite copper foil in Example 1.

[0046] In the figure: 1-copper foil substrate, 2-moisture-resistant and corrosion-resistant conductive coating. DETAILED DESCRIPTION

[0047] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0048] It should be apparent to those skilled in the art that the embodiments are only intended to help understand the present invention and should not be considered as specific limitations of the present invention.

[0049] Example 1

[0050] This embodiment provides a composite copper foil, such as Figure 1 As shown, the composite copper foil includes a copper foil substrate 1, and also includes a moisture-resistant and corrosion-resistant conductive coating 2 arranged on the surface of the copper foil substrate 1, wherein the moisture-resistant and corrosion-resistant conductive coating 2 is a mixture film layer of an organic conductive polymer and conductive carbon, and the mixture film layer is a mixture film layer of P3HT (weight average molecular weight of 38,000), graphene and carbon nanotubes, wherein the mass ratio of the organic conductive polymer to the conductive carbon is 95:5, and the mass ratio of the graphene to the carbon nanotubes is 1:1; the thickness of the moisture-resistant and corrosion-resistant conductive coating 2 is 2 μm.

[0051] Example 2

[0052] This embodiment provides a composite copper foil, in which the thickness of the moisture-resistant and corrosion-resistant conductive coating 2 is adjusted from 2 μm to 6 μm. Except for the above, other conditions are exactly the same as those in Example 1.

[0053] Example 3

[0054] This embodiment provides a composite copper foil, in which the thickness of the moisture-resistant and corrosion-resistant conductive coating 2 is adjusted from 2 μm to 12 μm. Except for the above, other conditions are exactly the same as those in Example 1.

[0055] Example 4

[0056] This embodiment provides a composite copper foil, in which the thickness of the moisture-resistant and corrosion-resistant conductive coating 2 is adjusted from 2 μm to 18 μm. Except for the above, other conditions are exactly the same as those in Example 1.

[0057] Example 5

[0058] The present embodiment provides a composite copper foil, wherein the thickness of the moisture-resistant corrosion-resistant conductive coating layer 2 is adjusted from 2 μm to 18 μm, and the mass ratio of the organic conductive polymer to the conductive carbon is adjusted from 95:5 to 70:30, and the other conditions are the same as those in Embodiment 1.

[0059] Embodiment 6

[0060] The present embodiment provides a composite copper foil, wherein the thickness of the moisture-resistant corrosion-resistant conductive coating layer 2 is adjusted from 2 μm to 60 μm, and the other conditions are the same as those in Embodiment 1.

[0061] Embodiment 7

[0062] The present embodiment provides a composite copper foil, wherein the thickness of the moisture-resistant corrosion-resistant conductive coating layer 2 is adjusted from 1 μm to 16 μm, and the other conditions are the same as those in Embodiment 7.

[0063] Embodiment 8

[0064] The present embodiment provides a composite copper foil, wherein the thickness of the moisture-resistant corrosion-resistant conductive coating layer 2 is adjusted from 1 μm to 30 μm, and the other conditions are the same as those in Embodiment 7.

[0065] Embodiment 9

[0066] The present embodiment provides a composite copper foil, wherein the thickness of the moisture-resistant corrosion-resistant conductive coating layer 2 is adjusted from 1 μm to 30 μm, and the other conditions are the same as those in Embodiment 7.

[0067] In Embodiments 1 to 9, the method for manufacturing the composite copper foil comprises the following steps:

[0068] A copper foil substrate is prepared, and the copper foil substrate is pre-activated by surface plasma to be ready for use.

[0069] A coating solution is prepared, which contains an organic conductive polymer, or further contains conductive carbon; specifically, the conductive carbon is pre-mixed with an aqueous dispersant SDBS and water, homogenized by a double planetary or high-speed disperser, and then ground and dispersed by a sand mill to obtain a dispersion liquid A, wherein the absolute value of the Zeta potential of the dispersion liquid A is greater than 30 mV, and the mixture is stirred uniformly and ready for use. The organic conductive polymer is mixed with an organic solvent to prepare a solution B, and the dispersion liquid A and the solution B are mixed to obtain the coating solution.

[0070] The coating solution is coated on the surface of the copper foil substrate by micro gravure roll coating, the speed of the micro gravure roll coating is controlled to be 20 m / min, and then the wet and corrosion resistant conductive coating is formed by hot air drying at 88°C, to obtain the composite copper foil.

[0071] Comparative Example 1

[0072] This comparative example uses the copper foil substrate 1 in Example 1 as the current collector, without any coating layer disposed thereon.

[0073] Characterization and testing:

[0074] 1) Adhesion test: The adhesion test of the wet and corrosion resistant conductive coating is carried out according to the adhesion test standard of ASTM D3359, and the peeling off condition of the tape peeling is recorded.

[0075] 2) Resistivity test: The negative electrode slurry is coated on the coating layer of the composite copper foil obtained in Examples 1 to 10, and the negative electrode slurry is coated on the copper foil substrate obtained in Comparative Example 1, to form the negative electrode active layer, and then the interface is tested for resistivity.

[0076] 3) Conductivity and environmental humidity relationship test: The composite copper foils obtained in Examples 1 to 10 and the copper foil substrate obtained in Comparative Example 1 are stored in different moisture environments for one week, and then the resistivity is tested.

[0077] The above results are recorded in Table 1.

[0078] Table 1

[0079]

[0080] As can be seen from the above, compared with Comparative Example 1, Examples 1-9 can greatly play the role of waterproof, moistureproof and corrosion resistant by setting the wet and corrosion resistant conductive coating, thereby improving the moisture resistance and water resistance of the composite copper foil, and effectively slowing down the increase of the conductivity after storage in a humidity environment; and the coating can increase the adhesion to the copper foil substrate and is not easy to fall off, and has good stability. As can be seen from Examples 7-9, when only the organic conductive polymer is included in the wet and corrosion resistant conductive coating, good waterproof and moistureproof effect can still be provided, but the conductivity of the composite copper foil is reduced, and the greater the thickness of the coating, the more obvious the influence on the conductivity and resistivity. At this time, as in Examples 1-6, when the conductive carbon is added to the wet and corrosion resistant conductive coating at the same time, the conductivity of the composite copper foil can be effectively improved, and the resistivity can be reduced, so it has the best comprehensive effect.

[0081] In summary, the present application sets a specific organic conductive polymer film layer or a mixture film layer of organic conductive polymer and conductive carbon on the copper foil, uses the characteristics of the organic conductive polymer film layer being uniform and dense and still maintaining the conductivity, so as to play the role of waterproof, moistureproof and corrosion prevention. The composite copper foil provided with the coating can eliminate the temperature and humidity control requirements in the storage and application process, and does not need to consider the environmental humidity and moisture. At the same time, the coating can increase the adhesion to the copper foil substrate, has good stability, and has good conductivity without affecting the effect when used as a current collector. Further, in order to ensure or improve the conductivity of the film layer formed by the organic polymer, the mixture film layer of organic conductive polymer and conductive carbon can be formed by using the conductive carbon, in which the organic polymer forms a continuous phase film, and the conductive carbon forms a conductive network as a dispersed phase, which effectively improves the conductivity of the mixture film layer.

[0082] The above describes the preferred embodiments of the present application in detail, but the present application is not limited to the specific details in the above embodiments, and various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application.

[0083] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the present application will not further describe various possible combinations.

[0084] In addition, various different embodiments of the present application can also be combined in any manner, as long as it does not deviate from the idea of the present application, and it should be considered as disclosed by the present application.

Claims

1. A composite copper foil, characterized in that: The composite copper foil comprises a copper foil substrate and a moisture-resistant and corrosion-resistant conductive coating provided on the surface of the copper foil substrate. The moisture-resistant and corrosion-resistant conductive coating comprises an organic conductive polymer.

2. The composite copper foil according to claim 1, wherein The thickness of the moisture-resistant and corrosion-resistant conductive coating is 1 to 100 μm.

3. The composite copper foil according to claim 1 or 2, characterized in that The organic conductive polymer includes at least one of polyacetylene, polyaniline, polypyrrole, polythiophene, polyparaphenylene vinylene, polyparaphenylene or polyphenylene sulfide; Preferably, the polythiophene includes at least one of a composite of poly(3-hexylthiophene) and / or poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate.

4. The composite copper foil according to any one of claims 1 to 3, characterized in that: The moisture-resistant and corrosion-resistant conductive coating further comprises conductive carbon; Preferably, the conductive carbon comprises graphene and / or carbon nanotubes; Preferably, the conductive carbon comprises graphene and carbon nanotubes in a mass ratio of (0.01-1):1; Preferably, the moisture-resistant and corrosion-resistant conductive coating comprises the organic conductive polymer and the conductive carbon in a mass ratio of (100-x):x, where x=0.1-99.

5. The composite copper foil according to any one of claims 1 to 4, characterized in that: The copper foil substrate has a rough surface and a smooth surface opposite to each other, and the moisture-resistant and corrosion-resistant conductive coating is arranged on the rough surface.

6. A method for manufacturing the composite copper foil according to any one of claims 1 to 5, characterized in that: The manufacturing method comprises: preparing a copper foil substrate, preparing a coating solution containing an organic conductive polymer; coating the coating solution on the surface of the copper foil substrate by micro-gravure roller coating, and forming a moisture-resistant and corrosion-resistant conductive coating after drying to obtain a composite copper foil.

7. The method for manufacturing a composite copper foil according to claim 6, wherein: The coating solution also includes conductive carbon; Preferably, the conductive carbon is pre-mixed with an aqueous dispersant and water, homogenized by a double planetary or high-speed disperser, and then ground and dispersed by a sand mill to obtain a dispersion A; the organic conductive polymer and an organic solvent are prepared into a solution B, and the dispersion A and solution B are mixed to obtain the coating solution; Preferably, the aqueous dispersant comprises SDBS (sodium dodecylbenzenesulfonate); Preferably, the absolute value of the Zeta potential of the dispersion A is >30 mV.

8. The method for producing a composite copper foil according to claim 6 or 7, wherein: The copper foil substrate is pre-treated with surface plasma activation; Preferably, the speed of the micro gravure roller coating is 1 to 100 m / min, and the thickness deviation of the coating formed by the micro gravure roller coating is <±5%; Preferably, the drying method includes hot air drying and / or infrared heating, and the drying temperature is 80-150°C.

9. A negative electrode plate, characterized in that: The negative electrode plate contains the composite copper foil according to any one of claims 1 to 8 as a current collector, and the active layer of the negative electrode plate is arranged on the surface of the moisture-resistant and corrosion-resistant conductive coating in the composite copper foil.

10. A battery, characterized in that: The battery comprises the negative electrode sheet according to claim 9.

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