Highly conductive coated carbon aluminum foil

Abstract

The utility model discloses a kind of high conductivity carbon-coated aluminum foil, belong to lithium battery field, a kind of high conductivity carbon-coated aluminum foil, comprising: aluminum foil base layer, as base material to support and fix coating piece, the inside of aluminum foil base layer top surface is uniformly distributed and is equipped with micropore;Coating piece, install in the top of aluminum foil base layer, for increasing the conductive effect of aluminum foil base layer, the bottom of coating piece and the position of microhole corresponding uniformly form anchor point, the top of conductive carbon coating is fixed with protective layer, the inside of conductive carbon coating is fixed with conductive grid layer, and conductive grid layer is composed of multiple first grid lines and multiple second grid lines, it can be realized, by the cooperation of aluminum foil base layer, coating piece, microhole and anchor point, coating piece can be fixed firm by the cooperation of microhole and anchor point in the top of aluminum foil base layer, while still can increase the conductive effect of conductive carbon coating by first grid line and second grid line, by protective layer and insulating layer increase protection and insulation effect.

Description

Technical Field

[0001] This utility model relates to the field of lithium batteries, and more specifically, to a highly conductive carbon-coated aluminum foil. Background Technology

[0002] Carbon-coated aluminum foil is a composite material consisting of an aluminum foil substrate coated with a layer of conductive carbon coating. As the negative electrode current collector in lithium-ion batteries, it effectively reduces battery internal resistance, improves rate performance, and extends cycle life.

[0003] However, existing carbon-coated aluminum foil technologies have the following problems: Insufficient conductivity: The carbon layer and the aluminum foil substrate have a simple physical contact, resulting in contact resistance. If the conductive network of the carbon layer itself is not dense enough, it will also affect the overall conductivity.

[0004] Poor adhesion: The carbon layer has weak adhesion to the smooth aluminum foil surface, and it is easy to fall off during the battery manufacturing process (such as rolling and slitting) or long-term cycling, resulting in battery performance degradation.

[0005] Coating uniformity is difficult to control: Traditional coating methods cannot guarantee absolute uniformity of coating at the micron level, and local thickness unevenness will affect the uniformity of current distribution.

[0006] For example, patent (CN109411762A) discloses a carbon-coated aluminum foil and its preparation method. The carbon-coated aluminum foil includes an aluminum foil body, a composite conductive layer and a CNT conductive layer sequentially applied outwards from the aluminum foil body. The preparation method of the carbon-coated aluminum foil includes the following steps: S1: pre-treating the aluminum foil body; S2: mixing and stirring the binder and solvent evenly, then adding two or more conductive agents and mixing evenly to obtain a composite conductive slurry; S3: loading the composite conductive slurry into an electrospinning device, spraying it onto the aluminum foil, and then drying to obtain a first layer of composite carbon-coated aluminum foil; S4: mixing and stirring the binder and solvent evenly, adding a CNT conductive agent and mixing evenly to obtain a CNT conductive slurry; S5: loading the CNT conductive slurry into an electrospinning device, spraying the CNT conductive layer onto the first layer of composite carbon-coated aluminum foil, and drying to obtain the carbon-coated aluminum foil. The double-layer coated carbon-coated aluminum foil prepared by this invention improves the conductivity, rate performance, and cycle performance of the conductive agent and the aluminum foil body. When using the above technology, the following technical problems were found in the existing technology: the existing carbon-coated aluminum foil has poor conductivity and cannot firmly connect the coating. Therefore, we designed a highly conductive carbon-coated aluminum foil to provide another technical solution to the above technical problems. Utility Model Content

[0007] 1. Technical problems to be solved To address the problems existing in the prior art, the purpose of this utility model is to provide a highly conductive carbon-coated aluminum foil. It can achieve the following: through the cooperation of the aluminum foil base layer, the coated component, the micropores, and the anchor points, the coated component can be firmly fixed on the top of the aluminum foil base layer by the cooperation of the micropores and the anchor points. At the same time, the conductivity of the conductive carbon coating can be increased by the first grid lines and the second grid lines, while the protection and insulation effects can be increased by the protective layer and the insulating layer.

[0008] 2. Technical Solution To solve the above problems, the present invention adopts the following technical solution.

[0009] A highly conductive carbon-coated aluminum foil, comprising: The aluminum foil base layer is used as a substrate to support and fix the coated parts. The top surface of the aluminum foil base layer is evenly provided with micropores. A coated component is installed on top of an aluminum foil substrate to increase the conductivity of the aluminum foil substrate. Anchor points are evenly distributed on the bottom of the coated component at positions corresponding to the micropores.

[0010] Furthermore, the thickness of the aluminum foil base layer is 8-20 μm.

[0011] Furthermore, the diameter of the micropore is 5-15 μm, the depth of the micropore is 1-3 μm, and the distance between two adjacent micropores is 20-50 μm.

[0012] Furthermore, the coated component consists of a conductive carbon coating, a protective layer, and an insulating layer. The protective layer is fixed on top of the conductive carbon coating, and insulating layers are fixed on both sides of the conductive carbon coating.

[0013] Furthermore, the thickness of the protective layer is 0.5-2 μm.

[0014] Furthermore, a conductive mesh layer is fixed inside the conductive carbon coating. The conductive mesh layer consists of multiple first mesh lines and multiple second mesh lines, with the first mesh lines and second mesh lines interlaced and fixed together.

[0015] Furthermore, the width of both the first and second grid lines is 10-30 μm, the spacing between any two adjacent first grid lines and any two adjacent second grid lines is 50-400 μm, and the thickness of both the first and second grid lines is 0.2-0.4 μm.

[0016] 3. Beneficial effects

[0017] Compared with existing technologies, the advantages of this utility model are: (1) This solution can fix the coated parts firmly on the top of the aluminum foil base layer by combining the aluminum foil base layer, coated parts, micropores and anchor points. At the same time, it can increase the conductivity of the conductive carbon coating by the first grid line and the second grid line, and increase the protection and insulation effect by the protective layer and the insulating layer.

[0018] (2) By opening the array of micropores, the coated parts can enter the interior of the micropores through the anchor points to achieve structural connection when coated on the top of the aluminum foil base layer, thus forming a dual combination mechanism of "mechanical interlocking + physical adsorption" to achieve greater stability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the micropore structure of this utility model; Figure 3 This is a schematic diagram of the anchor point structure of this utility model; Figure 4 This is a schematic diagram of the structure of the coated part of this utility model; Figure 5 This is a schematic diagram of the internal structure of the conductive carbon coating of this utility model.

[0020] Explanation of the labels in the diagram: 1. Aluminum foil base layer; 2. Coated part; 3. Micropores; 4. Anchor point; 5. Conductive carbon coating; 6. Protective layer; 7. Insulating layer; 8. First grid line; 9. Second grid line. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model. Example 1:

[0022] Please see Figures 1-5 ,include: The aluminum foil base layer 1 serves as a substrate to support and fix the coated part 2. Micropores 3 are evenly distributed inside the top surface of the aluminum foil base layer 1, thereby enhancing the anchoring effect of the coated part 2 through the array of micropores 3. Preferably, the thickness of the aluminum foil base layer 1 is 8-20 μm, and the surface of the aluminum foil base layer 1 can be treated accordingly as needed.

[0023] In this embodiment, the micropores 3 are formed by laser micro-etching to create a regularly arranged array of micro-pits on the top surface of the aluminum foil substrate 1.

[0024] The diameter of the micropore 3 is 5-15μm, the depth of the micropore 3 is 1-3μm, and the distance between two adjacent micropores 3 is 20-50μm. The thickness of the anchor point 4 after its formation is confirmed based on the thickness of the micropore 3, so that the thickness of the anchor point 4 is less than or equal to the thickness of the micropore 3. The coating component 2 is installed on the top of the aluminum foil base layer 1 to increase the conductivity of the aluminum foil base layer 1. Anchor points 4 are evenly distributed at the bottom of the coating component 2 and at the position corresponding to the micropores 3, so that the anchor points 4 can enter the interior of the micropores 3 to achieve the anchoring and fixing of the aluminum foil base layer 1 and the coating component 2. The coated component 2 consists of a conductive carbon coating 5, a protective layer 6, and an insulating layer 7. The conductive carbon coating 5 is located on the innermost side of the bottom, allowing the top of the anchor point 4 to be connected to the conductive carbon coating 5. The protective layer 6 is fixed to the top of the conductive carbon coating 5, and the protective layer 6 is fixed to the top of the conductive carbon coating 5 by coating. The protective layer 6 protects the outer side of the conductive carbon coating 5, preventing scratches or oxidation during processing. The insulating layer 7 is fixed to both sides of the conductive carbon coating 5, and the insulating layer 7 is fixed to both sides of the conductive carbon coating 5 by coating. The insulating layer 7 is located between the aluminum foil base layer 1 and the protective layer 6, thereby achieving insulation of the conductive carbon coating 5 and preventing short circuits. Preferably, the conductive carbon coating 5 is formed by electrostatic spraying and infrared curing of a mixture of multi-walled carbon nanotubes (CNTs) and conductive carbon black (mass ratio 8:2), with a thickness of 0.3–0.8µm.

[0025] Preferably, the thickness of the protective layer 6 is 0.5-2μm, and the material of the protective layer 6 is a polymer, so that the top and sides of the conductive carbon coating 5 can be protected by the protective layer 6 and the insulating layer 7 respectively.

[0026] The conductive carbon coating 5 has a conductive mesh layer fixed inside, which enhances the conductivity of the conductive carbon coating 5. The conductive mesh layer is composed of multiple first mesh lines 8 and multiple second mesh lines 9. The first mesh lines 8 and the second mesh lines 9 are interlaced and fixed, thereby connecting the multiple first mesh lines 8 and the multiple second mesh lines 9 to each other. The width of the first mesh lines 8 and the second mesh lines 9 is 10-30μm, and the spacing between two adjacent first mesh lines 8 and two adjacent second mesh lines 9 is 50-400μm. The thickness of the first mesh lines 8 and the second mesh lines 9 is 0.2-0.4μm, which is less than the thickness of the conductive carbon coating 5. The conductive mesh layer formed by the first mesh lines 8 and the second mesh lines 9 is formed by inkjet printing. In use: Aluminum foil base layer 1 is used as the processed substrate. Micropores 3 are evenly distributed on the surface of aluminum foil base layer 1, forming an array. Conductive carbon coating 5 is then sprayed onto the top of aluminum foil base layer 1. The bottom of conductive carbon coating 5 is connected to aluminum foil base layer 1 by anchor points 4 that enter the micropores 3. At the same time, when conductive carbon coating 5 is sprayed to the corresponding thickness, a conductive grid layer is printed inside conductive carbon coating 5, which enables conductive carbon coating 5 to achieve excellent conductivity. Insulating layer 7 is then coated on both sides of conductive carbon coating 5, and protective layer 6 is coated on the top of conductive carbon coating 5. The protective layer 6 and insulating layer 7 protect conductive carbon coating 5 and prevent scratches or oxidation during processing.

[0027] Example 2

[0028] Based on the above embodiment one, an application method is disclosed for use in high-performance flexible lithium-ion battery current collectors, with the following steps: Substrate treatment: A 15μm thick aluminum foil was selected as the aluminum foil base layer 1. Using a laser micro-etching device, a regular array of micropores 3 with a diameter of 10μm, a depth of 2μm, and a spacing of 30μm was prepared on its surface; Conductive layer preparation: Multi-walled carbon nanotubes and conductive carbon black were mixed at a mass ratio of 8:2 and uniformly coated onto the surface of treated aluminum foil using an electrostatic spraying process to form a conductive carbon coating 5 with a thickness controlled at 0.5µm. During the spraying process, the coating material flowed into the micropores 3 and, after curing, formed strong anchor points 4. Integrated conductive mesh: While spraying a conductive carbon coating, a conductive mesh layer composed of silver nanowires (as the first mesh line 8 and the second mesh line 9) is embedded inside using high-precision inkjet printing technology. The line width is 20 μm, the mesh spacing is 200 μm, and the thickness is 0.3 μm. This mesh greatly enhances the lateral conduction capability of electrons in the current collector plane; Applying protection: Finally, a 1μm thick layer of polyimide is coated on the conductive carbon coating as a protective layer 6, and insulating epoxy resin is coated on both sides as an insulating layer 7.

[0029] Results Achieved: When this composite current collector is used to fabricate flexible batteries, its electrodes exhibit extremely low interfacial resistance and superior adhesion. After 1000 bending tests and 500 charge-discharge cycles, the capacity retention rate is more than 20% higher than that of batteries using traditional current collectors, making it ideal for applications such as wearable devices where high battery reliability and flexibility are required.

[0030] Example 3

[0031] Based on the above embodiment one, an application method is disclosed for use in electromagnetic shielding (EMI) gaskets or sealing strips, with the following steps: Substrate and anchoring: A 20μm thick soft aluminum foil is used as the aluminum foil base layer 1. Similarly, micropores 3 (diameter 8μm, depth 1.5μm, spacing 40μm) are formed by laser micro-etching to provide a strong mechanical locking foundation for subsequent coatings; Constructing a conductive surface: A conductive carbon coating 5 with a thickness of 0.7µm was prepared by electrostatic spraying. This coating is firmly bonded to the aluminum foil using anchor points 4, ensuring that the shielding layer does not peel off under repeated deformation.

[0032] Enhanced shielding effectiveness: Inside the conductive carbon coating, an inkjet-printed copper-based conductive mesh layer is formed with a linewidth of 15μm and a mesh spacing of 100μm. This composite structure of "carbon base layer + metal mesh" produces a synergistic effect, providing broad surface conductivity and absorption through the carbon layer, while effectively reflecting electromagnetic waves through the highly conductive metal mesh, achieving excellent shielding performance over a wide frequency band (especially 1-10GHz).

[0033] Protection and Installation: A 0.8μm thick flexible acrylic resin protective layer 6 is applied over the conductive carbon coating 5 to prevent scratches and oxidation. The insulating layers 7 on both sides ensure that short circuits will not occur with other components during installation.

[0034] Results: Electromagnetic shielding pads made from this material are not only lightweight and flexible, making them easy to fit into gaps in the casing, but also offer a shielding effectiveness (SE) of over 60dB. The robust anchoring structure ensures that the shielding performance will not degrade due to coating peeling during long-term vibration or disassembly of the equipment. It is widely used in the shielding designs of 5G communication equipment, laptops, and precision medical instruments.

[0035] The above description is merely a preferred embodiment of this utility model; however, the protection scope of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in this utility model, based on the technical solution and its improved concept, should be included within the protection scope of this utility model.

Claims

1. A highly conductive carbon-coated aluminum foil, characterized in that: include: The aluminum foil base layer (1) serves as a substrate to support and fix the coated part (2). Micropores (3) are evenly distributed inside the top surface of the aluminum foil base layer (1). The coating component (2) is installed on top of the aluminum foil base layer (1) to increase the conductivity of the aluminum foil base layer (1). Anchor points (4) are evenly distributed at the bottom of the coating component (2) and at positions corresponding to the micropores (3).

2. The highly conductive carbon-coated aluminum foil according to claim 1, characterized in that: The thickness of the aluminum foil base layer (1) is 8-20 μm.

3. The highly conductive carbon-coated aluminum foil according to claim 1, characterized in that: The diameter of the micropore (3) is 5-15 μm, the depth of the micropore (3) is 1-3 μm, and the distance between two adjacent micropores (3) is 20-50 μm.

4. The highly conductive carbon-coated aluminum foil according to claim 1, characterized in that: The coated part (2) consists of a conductive carbon coating (5), a protective layer (6) and an insulating layer (7). The top of the conductive carbon coating (5) is fixed with a protective layer (6), and both sides of the conductive carbon coating (5) are fixed with insulating layers (7).

5. The highly conductive carbon-coated aluminum foil according to claim 4, characterized in that: The thickness of the protective layer (6) is 0.5-2 μm.

6. The highly conductive carbon-coated aluminum foil according to claim 4, characterized in that: The conductive carbon coating (5) has a conductive mesh layer fixed inside. The conductive mesh layer is composed of multiple first mesh lines (8) and multiple second mesh lines (9), and the first mesh lines (8) and second mesh lines (9) are interlaced and fixed.

7. The highly conductive carbon-coated aluminum foil according to claim 6, characterized in that: The width of the first grid line (8) and the second grid line (9) is 10-30μm, the spacing between two adjacent first grid lines (8) and two adjacent second grid lines (9) is 50-400μm, and the thickness of the first grid line (8) and the second grid line (9) is 0.2-0.4μm.

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