Carbon-coated current collector containing lithium replenishment coating layer and method for manufacturing same, lithium battery

Abstract

The present application provides a carbon-coated current collector containing a lithium replenishment coating layer, a method for manufacturing the same, and a lithium battery, which belongs to the technical field of lithium battery materials. [Solution] A method for manufacturing a carbon-coated current collector containing a lithium-replenished coating layer includes chemically etching a current collector substrate to embed a lithium-replenished material therein to form a lithium-replenished coating layer, and then applying a conductive carbon coating layer slurry to the surface of the lithium-replenished coating layer to form a conductive carbon coating layer. By chemically etching a current collector substrate to attach a lithium-replenished coating layer and then attaching a conductive carbon coating layer, the surface tension of the current collector can be improved, which is advantageous for the application and attachment of an electrode active material. At the same time, the introduction of the conductive carbon coating layer reduces the contact resistance between the electrode active material and the current collector, improving the usage consistency of lithium battery packs and significantly reducing the cost of lithium battery packs.

Description

[Technical Field]

[0001] The present application relates to the technical field of lithium battery materials, and more particularly to a carbon-coated current collector containing a lithium replenishment coating layer and a method for manufacturing the same, and a lithium battery. [Background technology]

[0002] As the demands for environmental protection and energy conservation in society, the country, and even the world become increasingly higher, the advantages of lithium batteries, such as a long cycle life and environmental protection and energy conservation, become more and more prominent. The development of lithium batteries in the direction of higher energy density, higher safety performance, and longer cycle life is also the general trend of the development of lithium batteries in the future.

[0003] Improving the gram capacity of positive and negative electrode active materials in lithium batteries is an important means for lithium batteries to achieve higher energy density and longer cycle life. However, in the prior art, the improvement of the gram capacity of positive and negative electrode active materials was due to the Li + and the number of transferable electrons of Li + Because the number of transitions and embeddings is limited, the space for improving the structure of the positive and negative electrode active materials themselves is extremely small.

[0004] By reducing the thickness of foil current collectors, the positive and negative electrode active materials of lithium batteries can achieve a high compaction ratio, further improving their gram capacity. Foil current collectors are the most common type of current collector currently available on the market. The thinnest possible thickness for aluminum foil is 10 micrometers, while the thinnest possible thickness for copper foil is 4.5 micrometers, which is essentially the limit of copper-aluminum materials. As the thickness decreases, the strength of foil current collectors decreases, making them unable to meet the performance requirements of lithium batteries. At the same time, from the perspective of lithium battery design principles, a higher compaction ratio affects the cycle life of lithium batteries. As the compaction ratio increases, the gaps in the active coating layer of the pole pieces decrease, reducing the channels for accommodating electrolyte and ion shuttles, thereby reducing the cycle life and safety performance of lithium batteries. Therefore, in order to improve the energy density and cycle life of lithium batteries, it is necessary to develop a new method for obtaining current collectors without reducing the thickness of the current collector. Summary of the Invention [Problem to be solved by the invention]

[0005] The following is a general overview of the subject matter described in detail herein, and is not intended to limit the scope of the claims.

[0006] In order to solve the problems mentioned in the background art, the present application aims to provide a carbon-coated current collector containing a lithium replenishment coating layer, a method for manufacturing the same, and a lithium battery. [Means for solving the problem]

[0007] To achieve the above object, in a first aspect, the present application provides a method for manufacturing a carbon-coated current collector with a lithium-replenished coating layer, the method comprising the steps of: chemically etching a current collector substrate to embed a lithium-replenished material therein to form a lithium-replenished coating layer; and then applying a conductive carbon coating layer slurry to the surface of the lithium-replenished coating layer to form a conductive carbon coating layer, thereby obtaining the carbon-coated current collector with a lithium-replenished coating layer.

[0008] Furthermore, first, a lithium replenishment material solution is prepared, the current collector substrate is immersed in the lithium replenishment material solution, and the current collector substrate is chemically etched to embed the lithium replenishment material.

[0009] Furthermore, in parts by mass, the lithium replenishment material solution comprises 30 to 35 parts of lithium replenishment material, 3 to 5 parts of hydrochloric acid, 2 to 8 parts of etching aid, and 47 to 55 parts of water, and the etching aid is hydrogen peroxide or hydrofluoric acid.

[0010] Furthermore, the lithium replenishment material includes at least one of lithium peroxide, lithium oxide, lithium carbonate, lithium sulfate, lithium borate, lithium metasilicate, lithium orthosilicate, lithium phosphate, and lithium hydroxide.

[0011] Furthermore, the current collector substrate is a copper foil, an aluminum foil, a composite copper foil, or a composite aluminum foil, and the composite copper foil is formed by plating copper onto the surface of a polymer film, and the composite aluminum foil is formed by plating aluminum onto the surface of a polymer film.

[0012] Furthermore, the current collector substrate is a copper foil or a composite copper foil, and the etching aid is 5 to 8 parts of hydrogen peroxide water.

[0013] Furthermore, the current collector substrate is an aluminum foil or a composite aluminum foil, and the etching aid is 2 to 5 parts of hydrofluoric acid.

[0014] Furthermore, when the current collector substrate after being chemically etched to embed the lithium replenishment material is dried and the solvent is evaporated, the lithium replenishment material adheres to the surface of the current collector substrate to form a lithium replenishment coating layer.

[0015] Furthermore, the conductive carbon coating layer slurry contains, in parts by mass, 6 to 8 parts of a conductive agent, 15 to 17 parts of a binder, 1 to 3 parts of an additive, and 76 to 78 parts of water.

[0016] Furthermore, the conductive agent includes at least one of graphite, acetylene black, carbon nanotubes, and graphene, the binder is a polyacrylate-based binder, and the additive includes at least one of calcium acetate, calcium hydroxide, calcium bicarbonate, and calcium hydroxide.

[0017] Furthermore, a conductive carbon coating layer slurry is prepared with the component blending ratio, and then the conductive carbon coating layer slurry is applied to the surface of the lithium replenishment coating layer by a gravure coating method, and dried, whereby a carbon-coated current collector containing a lithium replenishment coating layer is manufactured.

[0018] In a second aspect, the present application provides a carbon-coated current collector containing a lithium-replenished coating layer obtained by the above preparation method.

[0019] In a third aspect, the present application provides a lithium battery manufactured using the carbon-coated current collector with a lithium replenishment coating layer according to the first aspect. [Effects of the Invention]

[0020] Compared with the prior art, the carbon-coated current collector containing a lithium-replenished coating layer and its manufacturing method, and the lithium battery according to the present invention have the following advantages:

[0021] In the present invention, the thickness of the current collector substrate is not reduced, but rather the current collector substrate is chemically etched to form a lithium-supplemented coating layer, followed by the deposition of a conductive carbon coating layer. The introduction of the lithium-supplemented coating layer and the conductive carbon coating layer improves the surface roughness of the current collector, significantly increasing the surface tension of the current collector, significantly reducing the difficulty of applying the electrode active material to the current collector and improving the adhesion of the electrode active material to the current collector surface. Furthermore, the presence of the lithium-supplemented coating layer and the conductive carbon coating layer more effectively protects the current collector, thereby extending the service life of the lithium battery. At the same time, the introduction of the conductive carbon coating layer effectively reduces the contact resistance between the electrode active material and the current collector, significantly improving the usage consistency of lithium battery packs and significantly reducing the cost of lithium battery packs.

[0022] Other aspects may be understood after reading and understanding the drawings and detailed description. [Brief explanation of the drawings]

[0023] The drawings are intended to provide a further understanding of the technical solution of the present specification, constitute a part of the specification, and are used to interpret the technical solution of the present specification together with the examples of the present application, but are not intended to limit the technical solution of the present specification. [Figure 1] 1 is a process flow diagram of a method for manufacturing a carbon-coated current collector containing a lithium replenishment coating according to the present application. [Figure 2] 1 is a structural schematic diagram of a carbon-coated current collector containing a lithium-replenished coating layer according to the present application. [Explanation of symbols]

[0024] 1...chemical etching bath; 2...oven; 3...gravure coater; 4...current collector substrate; 5...lithium replenishment coating layer; 6...conductive carbon coating layer. DETAILED DESCRIPTION OF THE INVENTION

[0025] The technical solution of the present application will be described in detail below through specific examples.

[0026] In this application, a method for manufacturing a carbon-coated current collector containing a lithium-replenished coating layer involves first attaching a lithium-replenished coating layer to the surface of a current collector substrate by chemical etching, and then coating a conductive carbon coating layer on the outside of the lithium-replenished coating layer to prepare a carbon-coated current collector containing a lithium-replenished coating layer. The carbon-coated current collector is then used in a lithium battery. Specifically, the current collector substrate is a copper foil, an aluminum foil, a composite copper foil, or a composite aluminum foil. Here, the composite copper foil is formed by plating copper on the surface of a polymer film, and the composite aluminum foil is formed by plating aluminum on the surface of a polymer film. A lithium-replenished coating layer and a conductive carbon coating layer are attached to both surfaces of the current collector substrate.

[0027] In the present invention, a lithium-supplemented coating layer and a conductive carbon coating layer are sequentially deposited on the surface of a current collector substrate by dip coating and gravure coating. Figure 1 shows a flowchart of the production process for the carbon-coated current collector with a lithium-supplemented coating layer of the present invention. First, the current collector substrate is immersed in a chemical etching bath 1 filled with a lithium-supplemented material solution, and the current collector substrate is chemically etched and lithium-supplemented using the lithium-supplemented material solution. The substrate is then transferred to an oven 2 to evaporate the solvent in the lithium-supplemented material solution, forming a lithium-supplemented coating layer. Finally, a conductive carbon coating layer slurry is applied to the surface of the lithium-supplemented coating layer using a gravure coater 3, and the coating is dried in the oven 2, forming a conductive carbon layer.

[0028] First, a lithium replenishment material solution is prepared, and the current collector substrate is immersed in the lithium replenishment material solution. The current collector substrate is chemically etched to embed the lithium replenishment material. The lithium replenishment material solution contains, by mass, 30 to 35 parts of lithium replenishment material, 3 to 5 parts of hydrochloric acid, 2 to 8 parts of etching aid, and 47 to 55 parts of water. The lithium replenishment material includes at least one of lithium peroxide, lithium oxide, lithium carbonate, lithium sulfate, lithium borate, lithium metasilicate, lithium orthosilicate, lithium phosphate, and lithium hydroxide.

[0029] When the current collector substrate is copper foil or composite copper foil, the etching aid is 5 to 8 parts hydrogen peroxide solution. When the current collector substrate is aluminum foil or composite aluminum foil, the etching aid is 2 to 5 parts hydrofluoric acid.

[0030] The components in the lithium replenishment material solution are mixed uniformly according to the component mixing ratio, and then poured into a chemical etching bath. The current collector substrate is immersed in the chemical etching bath to perform chemical etching.

[0031] Among the components of the lithium replenishment material solution, a mixture of hydrochloric acid and hydrogen peroxide solution can etch the surface of copper foil or composite copper foil, and a mixture of hydrofluoric acid and hydrochloric acid can etch the surface of aluminum foil or composite aluminum foil, causing micron-order or even nano-order depressions to appear on the etched surface of the current collector substrate. The lithium replenishment material is then infiltrated into the depressions, dried, and the solvent is evaporated to allow the lithium replenishment material to adhere to the surface of the copper foil or aluminum foil, forming a lithium replenishment coating layer.

[0032] Etching the surface of the current collector substrate using chemical etching has several advantages. First, chemical etching causes little damage to the current collector substrate, ensuring the performance of the final current collector product. It also improves the initial charge / discharge efficiency and cycle life of lithium batteries manufactured using this current collector. Second, chemical etching of the current collector substrate improves the surface roughness of the current collector, resolving the problem of low surface tension of conventional current collector substrates and facilitating the infiltration of electrode active materials into the current collector surface. Third, when chemically etching the surface of the current collector substrate using a liquid compound, the treatment speed is faster and the treatment effect is more uniform, allowing for more precise control of the basis weight of the lithium supplementary coating layer and the conductive carbon coating layer.

[0033] Next, a conductive carbon coating layer slurry is applied to the surface of the lithium replenishment coating layer using a gravure coater, and dried to form a conductive carbon layer.

[0034] The conductive carbon coating layer slurry contains, by mass, 6 to 8 parts of a conductive agent, 15 to 17 parts of a binder, 1 to 3 parts of an additive, and 76 to 78 parts of water, where the conductive agent includes at least one conductive carbon material such as graphite, acetylene black, carbon nanotubes, and graphene, the binder is a polyacrylate-based binder including at least one of polyacrylic acid, glycidyl acrylate, glycidyl methacrylate, diacetone acrylamide, silicone-modified polyacrylate, and polyurethane-modified polyacrylate, and the additive includes at least one inorganic or organic calcium salt such as calcium acetate, calcium hydroxide, calcium bicarbonate, and calcium hydroxide.

[0035] Each component of the conductive carbon coating layer slurry is dispersed and homogenized at high speed using a planetary double disperser according to the component blending ratio. After homogenization, the slurry is uniformly applied to the lithium replenishment coating layer of the current collector using a gravure coater, and then dried to produce a carbon-coated current collector.

[0036] FIG. 2 is a structural schematic diagram of the carbon-coated current collector containing a lithium-replenished coating layer according to the present invention. The current collector substrate 4 is located in the middle, and on both sides of the current collector substrate 4, a lithium-replenished coating layer 5 and a conductive carbon coating layer 6 are sequentially formed.

[0037] The carbon-coated current collector containing the lithium supplementary coating layer according to the present invention is used to prepare battery pole pieces, and a ternary lithium battery is fabricated. The performance test of the ternary lithium battery shows that the lithium battery has high energy density, cycle life, and initial charge / discharge efficiency.

[0038] Example 1 The preparation of a carbon-coated current collector containing a lithium replenishment coating layer involves the following steps.

[0039] (1) Copper foil was prepared as a current collector substrate and prepared for use.

[0040] (2) A lithium replenishment material solution was prepared and the lithium replenishment material solution was injected into the chemical etching bath for use.

[0041] Here, in parts by mass, the lithium replenishment material solution contains 32 parts of lithium replenishment material, 4 parts of hydrochloric acid, 6 parts of hydrogen peroxide solution, and 50 parts of water, where the lithium replenishment material is lithium sulfate.

[0042] (3) A conductive carbon coating layer slurry was prepared and the conductive carbon coating layer slurry was added to a gravure coater and prepared for use.

[0043] Here, the conductive carbon coating layer slurry contains, by mass, 8 parts of a conductive agent, 16 parts of a binder, 2 parts of an additive, and 77 parts of water, of which the conductive agent is graphite, the binder is a polyacrylic acid binder, and the additive is calcium hydroxide.

[0044] (4) The current collector substrate was unwound into a chemical etching bath, and the surface of the current collector substrate was chemically etched to embed the lithium replenishment material. The current collector substrate was then sent into an oven to dry and volatilize the solvent, so that the lithium replenishment material was attached to the surface of the current collector substrate, forming a lithium replenishment coating layer.

[0045] (5) The current collector substrate having the lithium replenishment coating layer attached to its surface was fed into a gravure coater, and the conductive carbon coating layer slurry was applied and then dried to form a conductive carbon coating layer, thereby producing a carbon-coated current collector containing a lithium replenishment coating layer.

[0046] The basis weight of the lithium replenishment coating layer on the surface of the current collector substrate is 0.6 g / m on both sides. 2 The basis weight of the lithium supplement coating layer on each surface of the current collector substrate is the same. The basis weight of the conductive carbon coating layer is 1.6 g / m on both sides. 2 and the basis weight of the conductive carbon coating on each surface is the same.

[0047] The surface tension of the carbon-coated current collector containing the lithium replenishment coating layer according to Example 1 was measured, and the measured surface tension was 72 dynes.

[0048] Example 2 The preparation of a carbon-coated current collector containing a lithium replenishment coating layer involves the following steps.

[0049] (1) Aluminum foil was prepared as a current collector substrate and was ready for use.

[0050] (2) A lithium replenishment material solution was prepared and the lithium replenishment material solution was injected into the chemical etching bath for use.

[0051] Here, in parts by mass, the lithium replenishment material solution contains 31 parts of lithium replenishment material, 5 parts of hydrochloric acid, 6 parts of hydrofluoric acid, and 55 parts of water, wherein the lithium replenishment material is a mixture of lithium sulfate and lithium carbonate in a mass ratio of 1:1.

[0052] (3) A conductive carbon coating layer slurry was prepared and the conductive carbon coating layer slurry was added to a gravure coater and prepared for use.

[0053] Here, the conductive carbon coating layer slurry contains, by mass, 6 parts of a conductive agent, 15 parts of a binder, 1 part of an additive, and 78 parts of water, of which the conductive agent is carbon nanotubes, the binder is a glycidyl methacrylate binder, and the additive is calcium bicarbonate.

[0054] (4) The current collector substrate was unwound into a chemical etching bath, and the surface of the current collector substrate was chemically etched to embed the lithium replenishment material. The current collector substrate was then sent into an oven to dry and volatilize the solvent, so that the lithium replenishment material was attached to the surface of the current collector substrate, forming a lithium replenishment coating layer.

[0055] (5) The current collector substrate having the lithium replenishment coating layer attached to its surface was fed into a gravure coater, and the conductive carbon coating layer slurry was applied and then dried to form a conductive carbon coating layer, thereby producing a carbon-coated current collector containing a lithium replenishment coating layer.

[0056] The basis weight of the lithium replenishment coating layer on the surface of the current collector substrate is 0.5 g / m on both sides. 2 The basis weight of the lithium supplement coating layer on each surface of the current collector substrate is the same. The basis weight of the conductive carbon coating layer is 1.2 g / m on both sides. 2 and the basis weight of the conductive carbon coating layer on each surface is the same.

[0057] The surface tension of the carbon-coated current collector containing the lithium replenishment coating layer according to Example 2 was measured, and the measured surface tension was 69 dynes.

[0058] Example 3 The preparation of a carbon-coated current collector containing a lithium replenishment coating layer involves the following steps.

[0059] (1) Aluminum foil was prepared as a current collector substrate and was ready for use.

[0060] (2) A lithium replenishment material solution was prepared and the lithium replenishment material solution was injected into the chemical etching bath for use.

[0061] Here, in parts by mass, the lithium replenishment material solution contains 30 parts of lithium replenishment material, 3 parts of hydrochloric acid, 6 parts of hydrofluoric acid, and 52 parts of water, where the lithium replenishment material is lithium carbonate.

[0062] (3) A conductive carbon coating layer slurry was prepared and the conductive carbon coating layer slurry was added to a gravure coater and prepared for use.

[0063] Here, the conductive carbon coating layer slurry contains, by mass, 8 parts of a conductive agent, 17 parts of a binder, 1 part of an additive, and 77 parts of water, of which the conductive agent is graphite, the binder is a glycidyl methacrylate binder, and the additive is calcium bicarbonate.

[0064] (4) The current collector substrate was unwound into a chemical etching bath, and the surface of the current collector substrate was chemically etched to embed the lithium replenishment material. The current collector substrate was then sent into an oven to dry and volatilize the solvent, so that the lithium replenishment material was attached to the surface of the current collector substrate, forming a lithium replenishment coating layer.

[0065] (5) The current collector substrate having the lithium replenishment coating layer attached to its surface was fed into a gravure coater, and the conductive carbon coating layer slurry was applied and then dried to form a conductive carbon coating layer, thereby producing a carbon-coated current collector containing a lithium replenishment coating layer.

[0066] The basis weight of the lithium replenishment coating layer on the surface of the current collector substrate is 0.3 g / m on both sides. 2 The basis weight of the lithium supplement coating layer on each surface of the current collector substrate is the same. The basis weight of the conductive carbon coating layer is 0.8 g / m on both sides. 2and the basis weight of the conductive carbon coating layer on each surface is the same.

[0067] The surface tension of the carbon-coated current collector containing the lithium replenishment coating layer according to Example 3 was measured, and the measured surface tension was 68 dynes.

[0068] Example 4 The preparation of a carbon-coated current collector containing a lithium replenishment coating layer involves the following steps.

[0069] (1) A composite aluminum foil was prepared as a current collector substrate, and the composite aluminum foil was prepared for use according to the method of Chinese Patent Application CN114744213A.

[0070] (2) A lithium replenishment material solution was prepared and the lithium replenishment material solution was injected into the chemical etching bath for use.

[0071] Here, in parts by mass, the lithium replenishment material solution contains 30 parts of lithium replenishment material, 3 parts of hydrochloric acid, 2 parts of hydrofluoric acid, and 47 parts of water, wherein the lithium replenishment material is a mixture of lithium sulfate, lithium borate, and lithium carbonate in a mass ratio of 1:1:1.

[0072] (3) A conductive carbon coating layer slurry was prepared and the conductive carbon coating layer slurry was added to a gravure coater and prepared for use.

[0073] Here, the conductive carbon coating layer slurry contains, by mass, 8 parts of a conductive agent, 17 parts of a binder, 3 parts of an additive, and 76 parts of water, of which the conductive agent is a mixture of acetylene black and carbon nanotubes in a mass ratio of 1:1, the binder is a glycidyl methacrylate binder, and the additive is a mixture of calcium hydroxide and calcium bicarbonate in a mass ratio of 1:2.

[0074] (4) The current collector substrate was unwound into a chemical etching bath, and the surface of the current collector substrate was chemically etched to embed the lithium replenishment material. The current collector substrate was then sent into an oven to dry and volatilize the solvent, so that the lithium replenishment material was attached to the surface of the current collector substrate, forming a lithium replenishment coating layer.

[0075] (5) The current collector substrate having the lithium replenishment coating layer attached to its surface was fed into a gravure coater, and the conductive carbon coating layer slurry was applied and then dried to form a conductive carbon coating layer, thereby producing a carbon-coated current collector containing a lithium replenishment coating layer.

[0076] The basis weight of the lithium replenishment coating layer on the surface of the current collector substrate is 0.2 g / m on both sides. 2 The basis weight of the lithium supplement coating layer on each surface of the current collector substrate is the same. The basis weight of the conductive carbon coating layer is 0.6 g / m on both sides. 2 and the basis weight of the conductive carbon coating layer on each surface is the same.

[0077] The surface tension of the carbon-coated current collector containing the lithium replenishment coating layer according to Example 4 was measured, and the measured surface tension was 67 dynes.

[0078] Example 5 The preparation of a carbon-coated current collector containing a lithium replenishment coating layer involves the following steps.

[0079] (1) A composite copper foil was prepared as a current collector substrate, and the composite copper foil was prepared for use according to the method of Chinese Patent Application CN115458749A.

[0080] (2) A lithium replenishment material solution was prepared and the lithium replenishment material solution was injected into the chemical etching bath for use.

[0081] Here, in terms of parts by mass, the lithium replenishment material solution contains 33 parts of lithium replenishment material, 4 parts of hydrochloric acid, 6 parts of hydrogen peroxide solution, and 51 parts of water, of which the lithium replenishment material is a mixture of lithium orthosilicate, lithium sulfate, and lithium carbonate in a mass ratio of 1:1:2.

[0082] (3) A conductive carbon coating layer slurry was prepared and the conductive carbon coating layer slurry was added to a gravure coater and prepared for use.

[0083] Here, the conductive carbon coating layer slurry contains, by mass parts, 6 parts of a conductive agent, 16 parts of a binder, 2 parts of an additive, and 77 parts of water, of which the conductive agent is graphene, the binder is a silicone-modified polyacrylate binder, and the additive is calcium acetate.

[0084] (4) The current collector substrate was unwound into a chemical etching bath, and the surface of the current collector substrate was chemically etched to embed the lithium replenishment material. The current collector substrate was then sent into an oven to dry and volatilize the solvent, so that the lithium replenishment material was attached to the surface of the current collector substrate, forming a lithium replenishment coating layer.

[0085] (5) The current collector substrate having the lithium replenishment coating layer attached to its surface was fed into a gravure coater, and the conductive carbon coating layer slurry was applied and then dried to form a conductive carbon coating layer, thereby producing a carbon-coated current collector containing a lithium replenishment coating layer.

[0086] The basis weight of the lithium replenishment coating layer on the surface of the current collector substrate is 0.1 g / m on both sides. 2 The basis weight of the lithium supplement coating layer on each surface of the current collector substrate is the same. The basis weight of the conductive carbon coating layer is 0.4 g / m on both sides. 2 and the basis weight of the conductive carbon coating layer on each surface is the same.

[0087] The surface tension of the carbon-coated current collector containing the lithium replenishment coating layer according to Example 5 was measured, and the measured surface tension was 65 dynes.

[0088] Comparative Example 1 Copper foil was produced by metal fusion rolling, and the surface tension of the copper foil was measured to be 32 dynes.

[0089] Comparative Example 2 Aluminum foil was produced by a metal fusion rolling method, and the surface tension of the aluminum foil was measured to be 31 dynes.

[0090] The surface tension of the current collectors obtained in Examples 1 to 5 and Comparative Examples 1 and 2 was measured. After the lithium supplementary coating layer and the conductive carbon coating layer were dip-coated on the surface of the current collector substrate, the surface tension value against the copper foil or aluminum foil was significantly increased. It was found that when manufacturing battery electrodes under higher surface tension, the current collector and the active material can form stronger contact, prevent the active material from falling off, reduce the resistance of the battery electrode pieces, and further improve the performance of the lithium battery.

[0091] Battery pole pieces were manufactured using the current collectors obtained in Examples 1 to 5 and Comparative Examples 1 and 2. Ternary lithium batteries were then manufactured according to the method of Chinese Patent Application CN104852036A. Performance tests were conducted on the ternary lithium batteries, and the test results are shown in Table 1.

[0092] [Table 1]

[0093] The above are merely preferred embodiments of the present application, and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the design concept of the present application should be included within the protection scope of the present application.

Claims

1. 1. A method of manufacturing a carbon-coated current collector containing a lithium-replenished coating layer, comprising: a step of chemically etching a current collector substrate to embed a lithium replenishment material therein to form a lithium replenishment coating layer, and then coating a conductive carbon coating layer slurry on the surface of the lithium replenishment coating layer to form a conductive carbon coating layer, thereby obtaining the carbon coated current collector containing the lithium replenishment coating layer; Manufacturing method.

2. The chemical etching includes preparing a lithium replenishment material solution, immersing the current collector substrate in the lithium replenishment material solution, and chemically etching the current collector substrate to embed the lithium replenishment material; The method of claim 1.

3. In parts by weight, the lithium replenishment material solution comprises 30-35 parts lithium replenishment material, 3-5 parts hydrochloric acid, 2-8 parts etching aid, and 47-55 parts water; The etching aid is hydrogen peroxide or hydrofluoric acid. The method of claim 2.

4. the lithium replenishment material comprises at least one of lithium peroxide, lithium oxide, lithium carbonate, lithium sulfate, lithium borate, lithium metasilicate, lithium orthosilicate, lithium phosphate, and lithium hydroxide; The method of claim 3.

5. the current collector substrate is a copper foil, an aluminum foil, a composite copper foil, or a composite aluminum foil, The composite copper foil is formed by plating copper on the surface of a polymer film, and the composite aluminum foil is formed by plating aluminum on the surface of a polymer film. The method of claim 3.

6. the current collector substrate is a copper foil or a composite copper foil, and the etching aid is 5 to 8 parts of hydrogen peroxide solution; The method of claim 5.

7. the current collector substrate is an aluminum foil or a composite aluminum foil, and the etching aid is 2 to 5 parts hydrofluoric acid; The method of claim 5.

8. After the current collector substrate is chemically etched to embed the lithium replenishment material, the substrate is dried and the solvent is evaporated, whereby the lithium replenishment material adheres to the surface of the current collector substrate to form a lithium replenishment coating layer. The method of claim 1.

9. In parts by weight, the conductive carbon coating layer slurry comprises 6 to 8 parts of a conductive agent, 15 to 17 parts of a binder, 1 to 3 parts of an additive, and 76 to 78 parts of water; The method of claim 1.

10. the conductive agent includes at least one of graphite, acetylene black, carbon nanotubes, and graphene; the binder is a polyacrylate-based binder, The additive includes at least one of calcium acetate, calcium hydroxide, calcium bicarbonate, and calcium hydroxide. The method of claim 9.

11. A conductive carbon coating layer slurry is prepared according to the component blending ratio, and then the conductive carbon coating layer slurry is applied to the surface of the lithium replenishment coating layer by gravure coating, and dried to obtain a carbon-coated current collector containing a lithium replenishment coating layer. The method of claim 10.

12. Obtained by the manufacturing method according to any one of claims 1 to 11. A carbon-coated current collector containing a lithium-replenished coating layer.

13. Produced by the carbon-coated current collector containing the lithium-replenished coating layer of claim 12. Lithium battery.

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