Battery aluminum foil coating device and coating method, current collector, and battery

Abstract

Disclosed in the present application are a battery aluminum foil coating device and coating method, a current collector, and a battery. By means of passing aluminum foil through an unwinding mechanism, a double-sided coating assembly, a first-side coating assembly, a second-side coating assembly and a winding mechanism in sequence, double-sided coating is completed, thereby combining an aluminum-foil carbon layer coating procedure with an electrode slurry coating procedure, and thus greatly reducing the production cost, shortening the production cycle, and reducing the waste of resources.

Description

Battery aluminum foil coating apparatus and coating method, current collector and battery

[0001] This application claims priority to Chinese Patent Application No. 202411186900.X, filed with the Chinese Patent Office on August 27, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, and in particular to a battery aluminum foil coating apparatus and coating method, current collector, and battery. Background Technology

[0003] Currently, using functional coatings to treat the surface of battery conductive substrates is a groundbreaking technological innovation. Carbon-coated aluminum foil or copper foil involves uniformly and finely coating well-dispersed nano-conductive graphite and carbon-coated particles onto aluminum foil or copper foil. It can provide excellent static conductivity, collect micro-currents from active materials, improve the processing performance of the positive and negative electrodes of the battery, and enhance battery performance.

[0004] In the relevant design, a double-sided coating method is used to process the battery aluminum foil. First, the carbon coating slurry and the electrode slurry are mixed, and then the coating is applied to the front and back sides of the aluminum foil respectively. Invention Overview

[0005] Although this method can save resources and reduce operating costs, it requires two coating machines, which takes up a lot of space; in addition, this method requires the use of carbon coating slurry and electrode slurry of the same system, which has high requirements for materials and limits its application conditions.

[0006] In a first aspect, embodiments of this application provide a battery aluminum foil coating apparatus, comprising:

[0007] Unwinding mechanism, used for unwinding aluminum foil;

[0008] A double-sided coating assembly is used to first coat a carbon coating slurry on the first side of an aluminum foil, then coat a carbon coating slurry on the second side of the aluminum foil, and finally dry the first and second sides of the coated aluminum foil simultaneously.

[0009] The first coating assembly is used to sequentially coat the electrode paste and the ceramic insulating paste on the first surface of the aluminum foil, and to dry the first surface of the coated aluminum foil.

[0010] The second coating assembly is used to sequentially coat the electrode paste and the ceramic insulating paste on the second side of the aluminum foil, and to dry the second side of the coated aluminum foil.

[0011] A winding mechanism for winding up coated aluminum foil;

[0012] The aluminum foil is sequentially passed through the unwinding mechanism, the double-sided coating assembly, the first-sided coating assembly, the second-sided coating assembly, and the winding mechanism to complete the double-sided coating.

[0013] Secondly, embodiments of this application provide a method for coating battery aluminum foil, the method comprising at least the following steps:

[0014] After the aluminum foil roll is unwound by the unwinding mechanism, it is fed into the double-sided coating assembly.

[0015] Aluminum foil enters the double-sided coating assembly, where a carbon coating slurry is first applied to the first side of the aluminum foil, and then a carbon coating slurry is applied to the second side of the aluminum foil. After that, the first and second sides of the coated aluminum foil are dried simultaneously, and finally the aluminum foil with the carbon coating completed is sent to the first-sided coating assembly.

[0016] The aluminum foil enters the first coating assembly, where electrode paste and ceramic insulating paste are sequentially coated on the first surface of the aluminum foil after the carbon coating layer has been applied. The first surface of the aluminum foil after the electrode paste has been applied is then dried, and the aluminum foil is then sent to the second coating assembly.

[0017] The aluminum foil enters the second side coating assembly, where electrode paste and ceramic insulating paste are sequentially coated on the second side of the aluminum foil after the carbon coating layer has been applied. The second side of the aluminum foil after the electrode paste is applied is then dried, and the aluminum foil is then fed into the winding mechanism.

[0018] The aluminum foil is wound up by a winding mechanism to complete the coating process.

[0019] Thirdly, embodiments of this application provide a current collector comprising an aluminum foil, the aluminum foil being manufactured using the coating method described above for battery aluminum foil.

[0020] Fourthly, embodiments of this application provide a battery including a positive electrode and a negative electrode, wherein the positive electrode includes a positive current collector and a positive active material, and the negative electrode includes a negative current collector;

[0021] Wherein, at least one of the positive electrode current collector and the negative electrode current collector is the current collector described above. Beneficial effects

[0022] The beneficial effects of this application's embodiments are as follows: This application provides a battery aluminum foil coating apparatus and coating method, current collector, and battery. By sequentially passing the aluminum foil through the unwinding mechanism, the double-sided coating assembly, the first-sided coating assembly, the second-sided coating assembly, and the winding mechanism to complete double-sided coating, the aluminum foil carbon layer coating process and the electrode paste coating process are combined, greatly reducing production costs, shortening the production cycle, and reducing resource waste. Furthermore, compared to the traditional method that requires two separate machines to coat the first and second sides of the aluminum foil, this application integrates the coating function through the design of the double-sided coating assembly, greatly saving the footprint of the coating apparatus. At the same time, the double-sided coating assembly can coat the carbon layer on both sides of the aluminum foil, while the first-sided coating assembly and the second-sided coating assembly coat the electrode layer on the carbon layer, respectively. The step-by-step coating technology allows the use of different carbon layer pastes and electrode pastes, reducing the stringent requirements for material compatibility. Attached Figure Description

[0023] Figure 1 is a schematic diagram of the structure of a battery aluminum foil carbon layer coating device in the related technology;

[0024] Figure 2 is a schematic diagram of the battery aluminum foil electrode slurry coating device in the related technology;

[0025] Figure 3 is a schematic diagram of the structure of the battery aluminum foil carbon layer double-sided coating device in the related technology;

[0026] Figure 4 is a schematic diagram of the battery aluminum foil coating apparatus provided in the embodiment of this application;

[0027] Figure 5 is a flowchart of the battery aluminum foil coating method provided in the embodiments of this application;

[0028] Figure 6 is a top view of the first side of the battery aluminum foil provided in the embodiment of this application after the double-sided coating process is completed;

[0029] Figure 7 is a schematic diagram of the structure of the coating main layer provided in the embodiment of this application;

[0030] Figure 8 is a schematic diagram of the current collector structure provided in an embodiment of this application;

[0031] Figure 9 is a schematic diagram of the battery structure provided in the embodiment of this application.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1-Battery aluminum foil carbon layer coating device; 2-Battery aluminum foil electrode slurry coating device; 3-Double-sided coating device; 4-Battery aluminum foil coating device; 5-Current collector; 6-Battery;

[0034] 11-First aluminum foil unwinding mechanism; 12-Aluminum foil corona treatment mechanism; 13-Aluminum foil first side carbon coating mechanism; 14-First aluminum foil drying oven; 15-Aluminum foil second side carbon coating mechanism; 16-Second aluminum foil drying oven; 17-First aluminum foil winding mechanism;

[0035] 21-Second aluminum foil unwinding mechanism; 22-Aluminum foil first side electrode paste coating mechanism; 23-Third aluminum foil drying oven; 24-Aluminum foil second side electrode paste coating mechanism; 25-Fourth aluminum foil drying oven; 26-Second aluminum foil winding mechanism;

[0036] 31-Unwinding mechanism; 32-First side coating assembly; 33-Second side coating assembly; 34-Rewinding mechanism;

[0037] 41-Unwinding mechanism; 42-Double-sided coating assembly; 43-First-side coating assembly; 44-Second-side coating assembly; 45-Rewinding mechanism; 46-Corona treatment mechanism; 47-Correction correction mechanism;

[0038] 421-Double-sided carbon coating mechanism; 4211-First carbon coating mechanism; 4212-Second carbon coating mechanism; 4213-Frame; 422-Drying mechanism; 431-First side coating mechanism; 432-First oven; 441-Second side coating mechanism; 442-Second oven; 471-First correction structure; 473-Third correction structure;

[0039] 51-Coating layer; 511-Main coating layer; 512-Ceramic insulating layer; 5111-Carbon coating layer; 5112-Electrode layer; 52-Foil retention section; 53-Metal layer;

[0040] 61-Positive electrode; 62-Negative electrode; 63-Separator. Embodiments of the present invention

[0041] In the description of this application, unless otherwise expressly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0042] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, where the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, where the first feature is at a lower horizontal level than the second feature.

[0043] In the description of this embodiment, the terms "upper," "lower," "left," "right," "front," and "rear," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used for distinction in description and have no special meaning.

[0044] This embodiment provides a battery aluminum foil coating apparatus and coating method, a current collector, and a battery. These are described in detail below. It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments.

[0045] Please refer to Figure 4, which is a schematic diagram of the structure of the battery aluminum foil coating apparatus provided in the embodiments of this application.

[0046] In one embodiment, the battery aluminum foil coating apparatus 4 includes an unwinding mechanism 41, a double-sided coating assembly 42, a first-sided coating assembly 43, a second-sided coating assembly 44, and a winding mechanism 45. The unwinding mechanism 41 is used to unwind the aluminum foil. The double-sided coating assembly 42 is used to first coat a carbon coating slurry on the first side of the aluminum foil, then coat a carbon coating slurry on the second side of the aluminum foil, and finally simultaneously dry the first and second sides of the coated aluminum foil. The first-sided coating assembly 43 is used to coat the first side of the aluminum foil with a carbon coating slurry. The aluminum foil undergoes a two-stage coating process: first, the electrode paste and ceramic insulating paste are applied to the second side of the aluminum foil, and the first side of the coated aluminum foil is dried. The second-side coating assembly 44 applies the electrode paste and ceramic insulating paste to the second side of the aluminum foil sequentially, and the second side of the coated aluminum foil is also dried. The winding mechanism 45 winds up the coated aluminum foil. The aluminum foil undergoes double-sided coating by sequentially passing through the unwinding mechanism 41, the double-sided coating assembly 42, the first-side coating assembly 43, the second-side coating assembly 44, and the winding mechanism 45.

[0047] It is understood that this embodiment, by setting the battery aluminum foil coating device 4 to include an unwinding mechanism 41, a double-sided coating assembly 42, a first-sided coating assembly 43, a second-sided coating assembly 44, and a winding mechanism 45, avoids interference between different coating processes and improves the overall performance and production efficiency of the equipment. At the same time, the double-sided coating assembly 42, the first-sided coating assembly 43, and the second-sided coating assembly 44 each independently perform specific coating and drying processes, and the parameters of each part can be adjusted according to different needs to adapt to different production conditions and materials.

[0048] In one embodiment, the double-sided coating assembly 42 is located between the unwinding mechanism 41 and the first-sided coating assembly 43. The double-sided coating assembly 42 includes a double-sided carbon coating mechanism 421 and a drying mechanism 422 connected in sequence. The first-sided coating assembly 43 is located between the double-sided coating assembly 42 and the second-sided coating assembly 44. The first-sided coating assembly 43 includes a first-sided coating mechanism 431 and a first oven 432 connected in sequence. The second-sided coating assembly 44 is located between the first-sided coating assembly 43 and the winding mechanism 45. The second-sided coating assembly 44 includes a second-sided coating mechanism 441 and a second oven 442 connected in sequence. The aluminum foil passes through the unwinding mechanism, the double-sided carbon coating mechanism 421, the drying mechanism 422, the first-sided coating mechanism 431, the first oven 432, the second-sided coating mechanism 441, the second oven 442, and the winding mechanism 45 in sequence to complete the double-sided coating.

[0049] Furthermore, the double-sided carbon coating mechanism 421 is used to first coat the first side of the aluminum foil with a carbon coating slurry, and then coat the second side of the aluminum foil with a carbon coating slurry. The double-sided carbon coating mechanism 421 can be located at any position among the front end, rear end, above or below the unwinding mechanism 41, as long as it can sequentially feed the aluminum foil into the unwinding mechanism 41, the double-sided carbon coating mechanism 421 and the drying mechanism 422.

[0050] Specifically, the double-sided carbon coating mechanism 421 includes a first carbon coating mechanism 4211 and a second carbon coating mechanism 4212 connected in sequence. The first carbon coating mechanism 4211 is used to coat the first side of the aluminum foil with carbon coating slurry, and the second carbon coating mechanism 4212 is used to coat the second side of the aluminum foil with carbon coating slurry. The aluminum foil passes through the first carbon coating mechanism 4211 and the second carbon coating mechanism 4212 in sequence, thereby ensuring that the aluminum foil can be uniformly coated with carbon coating slurry on both sides by passing through the double-sided carbon coating mechanism 421, shortening the production cycle. At the same time, by setting the first carbon coating mechanism 4211 and the second carbon coating mechanism 4212 to process the two sides (first side and second side) of the aluminum foil respectively, the coating process parameters (such as coating speed, coating thickness, pressure, etc.) of each side can be adjusted independently, ensuring the uniformity and accuracy of coating.

[0051] In one embodiment, the double-sided carbon coating mechanism 421 further includes a frame 4213, wherein the first carbon coating mechanism 4211 and the second carbon coating mechanism 4212 are both located within the frame 4213. The second carbon coating mechanism 4212 can be located at any position among the front end, rear end, above, or below the first carbon coating mechanism 4211, as long as it can sequentially feed aluminum foil into the first carbon coating mechanism 4211 and the second carbon coating mechanism 4212. In this embodiment, the first carbon coating mechanism 4211 and the second carbon coating mechanism 4212 are arranged vertically within the frame 4213 as an example to illustrate the technical solution of this application.

[0052] It is understood that by placing both the first carbon layer coating mechanism 4211 and the second carbon layer coating mechanism 4212 within the frame 4213, this embodiment reduces the equipment's footprint and layout complexity, thus optimizing space utilization.

[0053] The drying mechanism 422 is located between the double-sided carbon layer coating mechanism 421 and the first-sided coating assembly 43. The drying mechanism 422 is used to simultaneously dry the first and second sides of the coated aluminum foil. The heat source of the drying mechanism 422 can be at least one of steam, electric heater, infrared, and microwave. A suitable drying method can be selected according to actual needs to ensure that the coated aluminum foil can be dried efficiently.

[0054] It should be noted that this embodiment uses an infrared oven as an example of the drying mechanism 422 to illustrate the technical solution of this application. The infrared oven uses infrared radiation heating, which can penetrate the air layer and directly heat the surface of the material, thereby rapidly increasing the temperature and accelerating the drying speed. The drying mechanism 422 may include an oven and multiple infrared heating elements located inside the oven. The multiple infrared heating elements are respectively installed at the top and bottom of the oven. The aluminum foil can move inside the oven via a conveyor belt. The design of the conveyor belt can ensure that the aluminum foil moves smoothly under the infrared heating elements, ensuring that both the first and second sides of the aluminum foil can receive infrared radiation simultaneously. At the same time, by adjusting the radiation intensity of the infrared heating elements at the top and bottom, the uniformity of heating of the first and second sides of the aluminum foil can be controlled.

[0055] In one embodiment, the first surface coating assembly 43 includes a first surface coating mechanism 431 and a first oven 432 connected in sequence; wherein, the first surface coating mechanism 431 is used to sequentially coat an electrode paste and a ceramic insulating paste on the first surface of an aluminum foil, and the first oven 432 is used to dry the first surface of the coated aluminum foil.

[0056] It should be noted that since the first coating mechanism 431 sequentially coats the electrode paste and the ceramic insulating paste on the dried carbon coating layer, the carbon coating paste and the electrode paste will not come into direct contact, thereby avoiding chemical reactions and incompatibility issues between them.

[0057] Specifically, the first surface coating mechanism 431 can be located at any position among the front end, rear end, above or below the drying mechanism 422, as long as it can sequentially feed the aluminum foil into the first surface coating mechanism 431 and the first drying oven 432. Specifically, this embodiment takes the example of the first surface coating mechanism 431 being located between the drying mechanism 422 and the first drying oven 432 to illustrate the technical solution of this application.

[0058] The first surface coating mechanism 431 includes a first die head, which can be divided into two areas: one area for coating the entire surface of the electrode paste and the other area for coating the edge of the ceramic insulating paste. These two areas can be separated by a fluid isolation structure to ensure that the two materials do not mix within the die head.

[0059] It is understood that this embodiment integrates the first surface coating assembly 43 and the first oven 432 connected in sequence into a single production line by setting the first surface coating assembly 43 to include the first surface coating mechanism 431 and the first oven 432, thereby saving space and reducing the equipment footprint. At the same time, after the first and second surfaces of the aluminum foil are dried by the drying mechanism 422, the first surface coating mechanism 431 can immediately coat the first surface of the aluminum foil with electrode paste, followed by ceramic insulating paste, and then dry it in the first oven 432. This reduces the transfer time and operational complexity of the aluminum foil between each step, simplifying the entire production process. Furthermore, it avoids the aluminum foil after carbon coating being exposed to air for a long time, which may cause oxidation and affect the adhesion of subsequent coating layers.

[0060] It should be noted that the carbon coating slurry forms a uniform coating on the aluminum foil surface, which fills in the microscopic unevenness of the aluminum foil surface, thereby providing a smoother and more consistent substrate. That is, in this embodiment, the electrode slurry is applied after the carbon coating slurry is applied, which can ensure the uniformity and adhesion of each coating layer. Furthermore, the carbon coating slurry provides a good conductive foundation, and the application of the electrode slurry can further improve the performance of the battery.

[0061] In one embodiment, the second surface coating assembly 44 includes a second surface coating mechanism 441 and a second oven 442 connected in sequence; wherein, the second surface coating mechanism 441 is used to sequentially coat an electrode paste and a ceramic insulating paste on the second surface of an aluminum foil, and the second oven 442 is used to dry the second surface of the coated aluminum foil.

[0062] Specifically, the second electrode slurry coating machine can be located at any position among the front end, rear end, above or below the first oven 432, as long as it can sequentially feed the aluminum foil into the second surface coating mechanism 441 and the second oven 442; specifically, this embodiment takes the second surface coating mechanism 441 located between the first oven 432 and the second oven 442 as an example to illustrate the technical solution of this application.

[0063] The second surface coating mechanism 441 includes a second die head, which can be divided into two areas: one area for coating the entire surface of the electrode paste and the other area for coating the edge of the ceramic insulating paste. These two areas can be separated by a fluid isolation structure to ensure that the two materials do not mix within the die head.

[0064] It is understood that this embodiment integrates the first surface coating mechanism 431 and the first oven 432 onto a single production line by setting the second surface coating assembly 44 to include a second surface coating mechanism 441 and a second oven 442 connected in sequence, thereby saving space and reducing the equipment footprint. At the same time, by coating the second surface coating mechanism 441 with electrode paste on the second surface of the aluminum foil, and drying the second surface of the coated aluminum foil in the second oven 442, it can be ensured that the coatings on both sides (the first and second surfaces) of the aluminum foil are processed under the same conditions, thereby ensuring that the thickness and quality of the double-sided coatings are consistent. Furthermore, after the first surface of the aluminum foil is dried in the first oven 432, the second surface coating mechanism 441 can immediately coat the second surface of the aluminum foil with electrode paste, and then it enters the second oven 442 for drying.

[0065] It should be noted that carbon-coated aluminum foil or copper foil involves uniformly and finely coating dispersed nano-conductive graphite and carbon-coated particles onto aluminum foil or copper foil. It provides excellent static conductivity, collects micro-currents from active materials, and can improve the processing performance of the positive and negative electrodes of the battery and enhance battery performance. Currently, most lithium battery companies directly purchase carbon-coated aluminum foil for coating, which is costly. To reduce the cost of incoming materials, some companies purchase cheaper double-sided bright aluminum foil and then sequentially perform carbon layer coating and electrode slurry processes on the surface of the aluminum foil to prepare the electrode sheets to be cut.

[0066] Specifically, please refer to Figure 1, which is a structural schematic diagram of a battery aluminum foil carbon coating apparatus in the related art. In the related art, the battery aluminum foil carbon coating apparatus 1 includes a first aluminum foil unwinding mechanism 11, an aluminum foil corona treatment mechanism 12, an aluminum foil first-side carbon coating mechanism 13, a first aluminum foil oven 14, an aluminum foil second-side carbon coating mechanism 15, a second aluminum foil oven 16, and a first aluminum foil winding mechanism 17. The aluminum foil is sequentially fed into the first aluminum foil unwinding mechanism 11, the aluminum foil corona treatment mechanism 12, the aluminum foil first-side carbon coating mechanism 13, the first aluminum foil oven 14, the aluminum foil second-side carbon coating mechanism 15, the second aluminum foil oven 16, and the first aluminum foil winding mechanism 17, thereby completing the carbon coating process on both sides of the aluminum foil.

[0067] Please refer to Figure 2, which is a structural schematic diagram of a battery aluminum foil electrode slurry coating device in the related art. In the related art, the battery aluminum foil electrode slurry coating device 2 includes a second aluminum foil unwinding mechanism 21, an aluminum foil first-side electrode slurry coating mechanism 22, a third aluminum foil drying oven 23, an aluminum foil second-side electrode slurry coating mechanism 24, a fourth aluminum foil drying oven 25, and a second aluminum foil winding mechanism 26. The aluminum foil that has completed the double-sided carbon layer coating process is sequentially fed into the second aluminum foil unwinding mechanism 21, the aluminum foil first-side electrode slurry coating mechanism, the third aluminum foil drying oven 23, the aluminum foil second-side electrode slurry coating mechanism 24, the fourth aluminum foil drying oven 25, and the second aluminum foil winding mechanism 26, thereby completing the double-sided electrode slurry coating process of the aluminum foil.

[0068] As can be seen from Figures 1 and 2, in the relevant technologies, aluminum foil carbon coating and electrode paste coating are two discontinuous processes. The aluminum foil carbon coating process and the electrode paste coating process require two unwinding and rewinding operations, which are cumbersome. In order to reduce the cost of incoming materials, some companies purchase lower-priced double-sided bright aluminum foil, which requires additional workshops to perform a carbon coating process on the surface of the aluminum foil. At the same time, the carbon-coated aluminum foil needs to be dried in an oven. After carbon coating, the aluminum foil is sent to the electrode coating workshop for electrode paste coating. The product realization cycle is long and labor costs are high.

[0069] Understandably, compared to the higher cost disadvantage of directly purchasing carbon-coated aluminum foil for electrode paste coating, this embodiment integrates the winding mechanism, the double-sided carbon layer coating mechanism 421, the drying mechanism 422, the first side coating mechanism 431, the first oven 432, the second side coating mechanism 441, the second oven 442, and the winding mechanism 45 onto a single production line, saving space and reducing the equipment footprint. Simultaneously, through a continuous and efficient production process, it reduces waste of equipment and human resources, thereby lowering production costs.

[0070] In addition, compared with related technologies, the aluminum foil coating process requires two coatings and two windings. In the battery aluminum foil coating device 4 provided in this embodiment, the aluminum foil can be coated on both sides with only one unwinding and one winding, which effectively reduces the cumbersomeness of operation, avoids manual handling of aluminum foil materials, and saves manpower.

[0071] It should be noted that the unwinding mechanism 41, the double-sided carbon coating mechanism 421, the drying mechanism 422, the first-sided coating mechanism 431, the first oven 432, the second-sided coating mechanism 441, the second oven 442, and the winding mechanism 45 can be connected by a conveyor belt. This embodiment does not impose specific restrictions on the connection method between the above mechanisms and / or components.

[0072] Please refer to Figure 3, which is a schematic diagram of the structure of a double-sided carbon coating device for battery aluminum foil in the related art. In the related art, the double-sided coating device 3 includes an unwinding mechanism 31, a first-side coating component 32, a second-side coating component 33, and a winding mechanism 34. The unwinding mechanism 31 is used to unwind the aluminum foil. The first-side coating component 32 is used to sequentially coat the carbon coating slurry and electrode slurry on the first side of the aluminum foil and dry the first side of the coated aluminum foil. The second-side coating component 33 is used to sequentially coat the carbon coating slurry and electrode slurry on the second side of the aluminum foil and dry the second side of the coated aluminum foil. The winding mechanism 34 is used to wind up the coated aluminum foil. The aluminum foil passes through the unwinding mechanism 31, the first-side coating component 32, the second-side coating component 33, and the winding mechanism 34 in sequence. That is, by combining the aluminum foil carbon coating process and the electrode slurry coating process, the production cost is greatly reduced, the production cycle is shortened, and resource waste is reduced.

[0073] In the double-sided coating apparatus 3 shown in Figure 3, the carbon coating slurry and the electrode slurry are mixed, and then the carbon coating slurry and the electrode slurry are sequentially coated on the first side of the aluminum foil. The first side of the coated aluminum foil is then dried. The carbon coating slurry and the electrode slurry are sequentially coated on the second side of the aluminum foil, and the second side of the coated aluminum foil is then dried, thus completing the double-sided coating. However, in order to achieve simultaneous drying of the carbon coating slurry and the electrode slurry, the solvent system of the carbon coating slurry and the solvent system of the electrode slurry must be the same, which limits its application conditions.

[0074] It is understood that the battery aluminum foil coating device 4 in this embodiment includes a double-sided coating component 42, a first-sided coating component 43, and a second-sided coating component 44. The double-sided coating component 42 can coat carbon coating slurry on both sides of the aluminum foil, and simultaneously dry the first and second sides of the coated aluminum foil, thereby forming a carbon coating layer on both sides. Then, the first-sided coating component 43 coats the carbon coating layer on the first side of the aluminum foil with electrode slurry, and then bakes the first side of the coated aluminum foil. The second coating assembly 44 coats the electrode paste onto the carbon coating layer on the second side of the aluminum foil and bakes the coated second side of the aluminum foil. Since the electrode paste is coated onto the dried carbon coating layer, even if the solvent system of the carbon coating paste and the solvent system of the electrode paste are different, the two pastes will not come into direct contact, thereby avoiding chemical reactions and incompatibility issues between them. That is, this embodiment uses a step-by-step coating technology to allow the use of carbon coating paste and electrode paste with different systems, thereby reducing the strict requirements for material compatibility.

[0075] It should be noted that since the electrode paste is applied to the dried carbon coating layer, the carbon coating paste has no effect on the application of the electrode paste. In this embodiment, the solvent system of the carbon coating paste and the solvent system of the electrode paste can be different, or they can be the same. That is, this embodiment does not impose specific restrictions on the solvent system of the carbon coating paste and the solvent system of the electrode paste.

[0076] Furthermore, in this embodiment, the battery aluminum foil coating apparatus 4 further includes a corona treatment mechanism 46 and a deviation correction mechanism 47; the corona treatment mechanism 46 is used to remove oil stains from the surface of the aluminum foil before coating; the deviation correction mechanism 47 is disposed between the drying mechanism 422 and the first surface coating mechanism 431; and / or, the deviation correction mechanism 47 is disposed between the first oven 432 and the second surface coating mechanism 441; and / or, the deviation correction mechanism 47 is disposed between the second oven 442 and the winding mechanism 45; the deviation correction mechanism 47 is used to adjust the aluminum foil feed offset and coating misalignment.

[0077] Specifically, the web-correcting mechanism 47 includes a first web-correcting structure 471, a second web-correcting structure (not shown in the figure), a third web-correcting structure 473, and a fourth web-correcting structure (not shown in the figure). The first web-correcting structure 471 is located between the corona treatment mechanism 46 and the double-sided coating assembly 42. The first web-correcting structure 471 is used to detect whether the aluminum foil is misaligned when it is conveyed on the conveyor belt between the corona treatment mechanism 46 and the double-sided coating assembly 42, and to adjust the foil conveyor belt offset. The second web-correcting structure is located between the drying mechanism 422 and the first side coating mechanism 431. The second web-correcting structure is used to detect whether the aluminum foil is misaligned between the drying mechanism 422 and the first side coating mechanism 431. The third correction structure 473 is located between the first oven 432 and the second surface coating mechanism 441. The third correction structure 473 is used to detect whether misalignment occurs when the aluminum foil is conveyed on the conveyor belt between the first oven 432 and the second surface coating mechanism 441, and to adjust the aluminum foil conveyor belt offset. The fourth correction structure is located between the second oven 442 and the winding mechanism 45. The fourth correction structure is used to detect whether misalignment occurs when the aluminum foil is conveyed on the conveyor belt between the second oven 442 and the winding mechanism 45, and to adjust the aluminum foil conveyor belt offset.

[0078] It is understood that this embodiment monitors and adjusts the aluminum foil feeding offset and coating misalignment by setting the first correction structure 471, the second correction structure, the third correction structure 473 and the fourth correction structure, thereby improving the aluminum foil coating accuracy and stabilizing the aluminum foil travel.

[0079] Please refer to Figures 4 and 5; Figure 5 is a flowchart of the battery aluminum foil coating method provided in the embodiment of this application.

[0080] This embodiment also provides a method for coating battery aluminum foil. It should be noted that, in one embodiment of the battery aluminum foil coating method, the aluminum foil is coated using the above-mentioned battery aluminum foil coating device to form a battery electrode sheet to be cut.

[0081] Step S10: After the aluminum foil roll is unwound by the unwinding mechanism 41, it is fed into the double-sided coating assembly 42.

[0082] Specifically, step S10 includes the following steps:

[0083] Step S11: After the aluminum foil roll is unwound by the unwinding mechanism 41, it can be fed into the corona treatment mechanism 46 by the guide roller; wherein, the corona treatment mechanism 46 is used to remove oil stains from the surface of the aluminum foil and change the surface energy of the aluminum foil, making it easier to bond with the base coating slurry in the subsequent process.

[0084] Step S12: After the aluminum foil roll passes through the corona mechanism 46, it can be sequentially fed into the first correction structure 471 and the double-sided coating assembly 42 by the guide roller; wherein, the first correction structure 471 is used to detect whether the aluminum foil is misaligned when it is conveyed on the conveyor belt between the corona mechanism 46 and the double-sided coating assembly 42, and to adjust the foil conveyor belt offset.

[0085] Step S20: The aluminum foil enters the double-sided coating assembly 42. The double-sided coating assembly 42 first coats the first side of the aluminum foil with a carbon coating slurry, and then coats the second side of the aluminum foil with a carbon coating slurry. After that, the first and second sides of the coated aluminum foil are dried simultaneously. Finally, the aluminum foil with the carbon coating completed is sent to the first side coating assembly 43.

[0086] Specifically, step S20 includes the following steps:

[0087] Step S21: The aluminum foil enters the first carbon layer coating mechanism 4211, and the first carbon layer coating mechanism 4211 coats the first surface of the aluminum foil with carbon layer paste, and then the aluminum foil is fed into the second carbon layer coating mechanism 4212.

[0088] Specifically, the coating method of the carbon coating slurry includes, but is not limited to, gravure transfer coating. The first carbon coating mechanism 4211 includes a first gravure coating roller, which performs carbon coating slurry coating on the first side by driving the aluminum foil to move.

[0089] Step S22: The aluminum foil enters the second carbon layer coating mechanism 4212, and the second carbon layer coating mechanism 4212 is used to coat the second side of the aluminum foil with carbon layer slurry, and then the aluminum foil is sent into the drying mechanism 422.

[0090] The carbon coating slurry can be an aqueous system, and includes, but is not limited to, a main powder, a special adhesive, and an organic solvent. The main powder can be either carbon black (SP) or graphene (GR). The special adhesive can include polymer binders such as polyacrylic acid (PAA), polyvinyl alcohol (PVA), polytetrafluoroethylene (PTFE), polyolefins (PP, PE, and other copolymers), polyvinylidene fluoride (PVDF), and modified SBR rubber, which can form a robust coating after drying. The organic solvent can be deionized water.

[0091] Specifically, the coating method of the carbon coating slurry includes, but is not limited to, gravure transfer coating. The second carbon coating mechanism 4212 includes a second gravure coating roller, which performs carbon coating slurry coating on the second side by driving the aluminum foil to move.

[0092] It should be noted that after applying the carbon coating slurry to the second side of the aluminum foil, the thickness and defects of the carbon coating on the first and second sides of the aluminum foil can be detected by foil inspection equipment. This ensures that the width of the aluminum foil is within the preset specification range and does not exceed the tolerance range. At the same time, any defects on the surface of the aluminum foil, such as bubbles, cracks, uncoated areas, uneven coating, etc., can be identified. After identifying defects, the defective aluminum foil can be rejected or reworked in subsequent production processes. In this embodiment, the type of foil inspection equipment is not specifically limited. This embodiment uses a micro-charge-coupled device (CCD) camera as an example to illustrate the technical solution of this application.

[0093] Step S23: The aluminum foil enters the drying mechanism 422, and the first and second sides of the coated aluminum foil are dried simultaneously by the drying mechanism 422. Then, the aluminum foil with the carbon coating layer is sent to the first side coating assembly 43.

[0094] It should be noted that before the aluminum foil enters the drying mechanism 422, since the carbon coating slurry on the first and second sides of the aluminum foil is not dry, a spreading roller can be used to guide the aluminum foil into the drying mechanism 422. By controlling the tension of the aluminum foil during the drying process, it can be ensured that the coating on the surface of the coated foil is uniform and free of wrinkles or other defects.

[0095] Specifically, the heat source of the drying mechanism 422 can be at least one of steam, electric heater, infrared, and microwave. A suitable drying method can be selected according to actual needs to ensure that the coated aluminum foil can be dried efficiently. This embodiment takes the drying mechanism 422 as an infrared oven as an example to illustrate the technical solution of this application.

[0096] The drying mechanism 422 may include an oven and multiple infrared heating elements located inside the oven. The multiple infrared heating elements are respectively installed at the top and bottom of the oven. The aluminum foil can move inside the oven via a conveyor belt. The design of the conveyor belt can ensure that the aluminum foil moves smoothly under the infrared heating elements, so that the first and second sides of the aluminum foil can receive infrared radiation simultaneously. At the same time, by adjusting the radiation intensity of the infrared heating elements at the top and bottom, the uniformity of heating of the first and second sides of the aluminum foil can be controlled.

[0097] The drying temperature of the drying mechanism 422 is greater than or equal to 70 degrees Celsius and less than or equal to 170 degrees Celsius, and the drying time of the drying mechanism 422 is greater than or equal to 3 seconds and less than or equal to 9 seconds. The baking time of the aluminum foil is only related to the speed of the conveyor belt. The faster the conveyor belt is, the shorter the baking time. The speed of the conveyor belt is greater than or equal to 20 meters / minute and less than or equal to 70 meters / minute. The length of the drying mechanism is approximately 3 meters.

[0098] Furthermore, after the aluminum foil is dried by the drying mechanism 422, it can be inspected by a surface density meter. The surface density meter is an instrument used to measure the quality of the coating on the surface of a material. The surface density meter can use X-rays or beta rays as detection methods. The surface density meter can detect the surface density of the carbon coating layer on the surface of the aluminum foil, that is, the quality of the carbon coating layer per unit area, thereby ensuring that the coating is uniform and meets the predetermined specifications and standards.

[0099] It is understood that in this embodiment, the double-sided coating assembly 42 can coat carbon coating slurry on both sides of the aluminum foil, and simultaneously dry the first and second sides of the coated aluminum foil, so that the water or other solvents in the carbon coating slurry evaporate, and the carbon coating slurry dries and adheres to the surface of the aluminum foil, thereby forming a carbon coating layer on both the first and second sides of the aluminum foil.

[0100] Furthermore, in step S20, after the aluminum foil is tested by the areal density meter, the aluminum foil can be sequentially fed into the second correction structure and the first surface coating assembly 43 by a conveyor belt; wherein, the second correction structure is used to detect whether the aluminum foil is misaligned when it is conveyed on the conveyor belt between the drying mechanism 422 and the first surface coating assembly 43.

[0101] Step S30: The aluminum foil enters the first side coating assembly 43. The first side coating assembly 43 sequentially coats the first side of the aluminum foil after the carbon coating layer has been applied with electrode paste and ceramic insulating paste. The first side of the aluminum foil after the electrode paste is applied is dried. Then the aluminum foil is sent to the second side coating assembly 44.

[0102] Specifically, step S30 includes the following steps:

[0103] Step S31: The aluminum foil enters the first surface coating mechanism 431. The first surface coating mechanism 431 sequentially coats the first surface of the aluminum foil after the carbon coating layer has been applied with electrode paste and ceramic insulating paste. Then the aluminum foil is sent into the first oven 432.

[0104] The electrode slurry can be an oil-based system, comprising an active material, a binder, a dispersant, a conductive agent, and an organic solvent. The active material can be lithium iron phosphate, the binder can be polyvinylidene fluoride, the dispersant can be YTF003, the conductive agent can be carbon nanotubes, and the organic solvent can be N-methylpyrrolidone (NMP). The solvent system of the ceramic insulating slurry is the same as that of the electrode slurry. Since they belong to the same system, the ceramic insulating slurry and the electrode slurry can be miscible at their interface and are easily dried together during subsequent drying processes. It should be noted that this embodiment does not impose specific limitations on the material of the ceramic insulating slurry.

[0105] Furthermore, the viscosity of the electrode slurry is greater than or equal to 5000 mPa·s and less than or equal to 25000 mPa·s, and the viscosity of the ceramic insulating slurry is greater than or equal to 1000 mPa·s and less than or equal to 7000 mPa·s; the solid content of the electrode slurry is greater than or equal to 60% and less than or equal to 70%, and the solid content of the ceramic insulating slurry is greater than or equal to 30% and less than or equal to 38%.

[0106] Specifically, the first surface coating mechanism 431 may include a first die head, which may be divided into two areas: one area for coating the entire surface of the electrode paste and the other area for coating the edge of the ceramic insulating paste; wherein, the two areas may be separated by a fluid isolation structure to ensure that the two materials do not mix in the die head.

[0107] It should be noted that, in this embodiment, after the first side coating mechanism 431 completes the coating of electrode paste and ceramic insulating paste on the first side of the aluminum foil, a surface density meter can be used to detect the wet film surface density of the coated aluminum foil. This allows for the timely detection of potential problems during the coating process, such as uneven coating or thickness deviation, ensuring that each batch of products meets the standards. Furthermore, based on the measurement results, the parameters of the coating equipment, such as coating speed, paste supply, and coating pressure, can be adjusted in real time to optimize the coating effect.

[0108] Step S32: The aluminum foil enters the first drying oven 432, and the first side of the coated aluminum foil is dried using the first drying oven 432. Then the aluminum foil is sent to the second side coating assembly 44.

[0109] The drying temperature of the first oven 432 is greater than or equal to 85 degrees Celsius and less than or equal to 105 degrees Celsius, and the drying time of the aluminum foil in the first oven 432 is greater than or equal to 2 minutes and less than or equal to 4 minutes.

[0110] Specifically, the first oven 432 has a flowing high-temperature airflow, and the solvent of the electrode paste is carried away by the flowing high-temperature airflow, thereby drying the first side of the aluminum foil. It should be noted that the first side of the dried aluminum foil can be stabilized by an airflow cooling system, a tensioning system, a dry film detection system, and a correction structure to ensure the stability of the electrode paste and the ceramic insulating paste.

[0111] It should be noted that, in this embodiment, after the aluminum foil is dried by the first oven 432, the dry film surface density of the dried aluminum foil can be detected by a surface density meter. This allows for the timely detection of potential problems during the coating process, such as uneven coating or thickness deviation, ensuring that each batch of products meets the standards. Furthermore, based on the measurement results, the parameters of the coating equipment, such as coating speed, slurry supply, and coating pressure, can be adjusted in real time to optimize the coating effect. Additionally, guide rollers or tension separating rollers can be installed between the first oven 432 and the second surface coating assembly 44. These rollers or tension separating rollers separate the aluminum foil passing through the first oven 432 from subsequent processes, allowing the tension at the outlet of the first oven 432 and the subsequent processes to be controlled independently, avoiding mutual interference.

[0112] Understandably, combining the electrode paste coating process of aluminum foil with the ceramic insulating layer paste coating process greatly reduces production costs, shortens the production cycle, and reduces resource waste.

[0113] Furthermore, in step S30, after the aluminum foil is tested by the areal density meter, the aluminum foil can be fed sequentially into the third correction structure 473 and the second electrode slurry coating machine by a conveyor belt. The third correction structure 473 is used to detect whether the aluminum foil is misaligned when it is conveyed on the conveyor belt between the first oven 432 and the second surface coating mechanism 441, and to adjust the offset of the aluminum foil conveyor belt.

[0114] Step S40: The aluminum foil enters the second side coating assembly 44. The second side coating assembly 44 sequentially coats the second side of the aluminum foil after the carbon coating layer has been applied with electrode paste and ceramic insulating paste. The second side of the aluminum foil after the electrode paste is applied is dried, and then the aluminum foil is sent to the winding mechanism 45.

[0115] Specifically, step S40 includes the following steps:

[0116] Step S41: The aluminum foil enters the second surface coating mechanism 441. The second surface coating mechanism 441 sequentially coats the electrode paste and ceramic insulating paste on the second surface of the aluminum foil after the carbon coating layer has been applied. Then the aluminum foil is sent into the second oven 442.

[0117] Specifically, the coating method of the electrode paste includes, but is not limited to, one of transfer coating, extrusion coating or wet coating; the second surface coating mechanism 441 may include a second die head, which may be divided into two areas, one area for coating the entire surface of the electrode paste and the other area for coating the edge of the ceramic insulating paste; wherein, the two areas can be separated by a fluid isolation structure to ensure that the two materials do not mix in the die head.

[0118] It should be noted that, in this embodiment, after the second coating mechanism 441 coats the second side of the aluminum foil with electrode paste and ceramic insulating paste, a surface density meter can be used to detect the wet film surface density of the second side of the aluminum foil after the electrode paste coating. This allows for the timely detection of potential problems during the coating process, such as uneven coating or thickness deviation, ensuring that each batch of products meets the standards. Furthermore, based on the measurement results, the parameters of the coating equipment, such as coating speed, paste supply, and coating pressure, can be adjusted in real time to optimize the coating effect.

[0119] Step S42: The aluminum foil enters the second drying oven 442, and the second side of the coated aluminum foil is dried using the second drying oven 442. Then, the coated aluminum foil is guided into the winding mechanism 45 by the guide roller.

[0120] The drying temperature of the second oven 442 is greater than or equal to 90 degrees Celsius and less than or equal to 115 degrees Celsius, and the drying time of the aluminum foil in the second oven 442 is greater than or equal to 2 minutes and less than or equal to 4 minutes.

[0121] Specifically, the second oven 442 has a flowing high-temperature airflow, and the solvent of the electrode paste is carried away by the flowing high-temperature airflow, thereby drying the second side of the aluminum foil. It should be noted that the second side of the dried aluminum foil can be stabilized by an airflow cooling system, a tensioning system, a dry film detection system, and a correction structure to ensure the stability of the electrode paste and the ceramic insulating paste.

[0122] It is understood that in this embodiment, the electrode paste is coated on the carbon layer on the first side of the aluminum foil by the first side coating component 43, and the first side of the coated aluminum foil is baked. The electrode paste is coated on the carbon layer on the second side of the aluminum foil by the second side coating component 44, and the second side of the coated aluminum foil is baked. Since the electrode paste is coated on the dried carbon layer, even if the solvent system of the carbon layer paste and the solvent system of the electrode paste are different, the two pastes will not come into direct contact, thereby avoiding chemical reactions and incompatibility issues between them. That is, this embodiment adopts a step-by-step coating technology that allows the use of carbon layer paste and electrode paste with different systems, thereby reducing the strict requirements for material compatibility.

[0123] It should be noted that the carbon coating slurry is an aqueous system, and the electrode slurry is an oil-based system. The difference between the solvent system of the carbon coating slurry and the solvent system of the electrode slurry is only for illustrative purposes. In this embodiment, since the electrode slurry is coated on the dried carbon coating layer, the carbon coating slurry has no effect on the coating of the electrode slurry. Therefore, the solvent system of the carbon coating slurry and the solvent system of the electrode slurry can be the same. For example, the solvent of the carbon coating slurry and the electrode slurry can both be oil-based systems. That is, this embodiment does not impose specific restrictions on the solvent system of the carbon coating slurry and the solvent system of the electrode slurry.

[0124] Please refer to Figures 6 and 7; Figure 6 is a top view of the battery aluminum foil after the double-sided coating process is completed according to the embodiment of this application; Figure 7 is a structural schematic diagram of the coating main layer provided in the embodiment of this application.

[0125] It should be noted that Figure 6 can be a top view of the first side of the aluminum foil or a top view of the second side of the aluminum foil; this embodiment does not impose any specific limitations on this.

[0126] The aluminum foil includes a coating layer 51 and a foil retention portion 52. The coating layer 51 includes a main coating layer 511 and a ceramic insulating layer 512. The main coating layer 511 includes a carbon coating layer 5111 and an electrode layer 5112 stacked together. The ceramic insulating layer 512 is located between the main coating layer 511 and the foil retention portion 52.

[0127] In this embodiment, the electrode paste coating process and the ceramic insulating layer paste coating process are combined. The solvent system of the ceramic insulating layer paste is the same as that of the electrode paste. Therefore, when the electrode paste and the ceramic insulating layer paste are coated sequentially on the first surface of the aluminum foil, there is a contact fusion layer between the electrode paste and the ceramic insulating layer paste. Since the carbon layer coating process and the electrode paste coating process are completed separately, the carbon layer paste has been dried when the electrode paste is coated on the first surface of the aluminum foil. Therefore, there is no contact fusion layer between the electrode paste and the carbon layer paste on the first surface of the aluminum foil.

[0128] The ceramic insulating layer 512 and the coating layer 51 have an overlapping portion P, which is a contact fusion layer between the electrode paste and the ceramic insulating layer paste. The overlapping portion P points in the direction of the coating layer 51. The width of the overlapping portion P is greater than 0 and less than or equal to 0.5 mm. The width of the ceramic insulating layer 512 is greater than or equal to 2.6 mm and less than or equal to 3.2 mm.

[0129] Furthermore, in step S40, after the aluminum foil is dried by the second oven 442, the aluminum foil can be fed sequentially into the fourth correction structure and the winding mechanism 45 by a conveyor belt. The fourth correction structure is used to detect whether the aluminum foil is misaligned when it is conveyed on the conveyor belt between the second oven 442 and the winding mechanism 45, and to adjust the aluminum foil conveyor belt offset.

[0130] Step S50: The aluminum foil is wound up by the winding mechanism 45 to complete the coating of the aluminum foil.

[0131] It is understood that this embodiment saves space and reduces the footprint of equipment by integrating the winding mechanism, the double-sided carbon coating mechanism 421, the drying mechanism 422, the first-side coating mechanism 431, the first drying oven 432, the second-side coating mechanism 441, the second drying oven 442, and the winding mechanism 45 onto a single production line. At the same time, through a continuous and efficient production process, production costs are greatly reduced, the production cycle is shortened, resource waste is reduced, and waste of equipment and human resources is reduced, thereby lowering production costs.

[0132] Furthermore, please refer to Comparative Example 1 below, which illustrates a coating method for battery aluminum foil in the related art.

[0133] Comparative Example 1:

[0134] The coating method for the battery aluminum foil in Comparative Example 1 includes the following steps:

[0135] D10: Aluminum foil is sequentially fed into aluminum foil unwinding mechanism 41, aluminum foil corona treatment mechanism 46, aluminum foil first side carbon coating mechanism, first aluminum foil oven, aluminum foil second side carbon coating mechanism, second aluminum foil oven and first aluminum foil winding mechanism 45, thereby completing the double-sided carbon coating process of aluminum foil.

[0136] Specifically, in related technologies, the carbon coating speed ranges from 180 m / min to 200 m / min, the temperature range of the first aluminum foil oven is from 85 degrees Celsius to 105 degrees Celsius, and the drying time of the first side of the aluminum foil in the first aluminum foil oven is 0.1 minutes; the coating speed of the second side of the aluminum foil is the same as that of the first side of the aluminum foil. When the carbon coating is applied to 10,000 meters of aluminum foil, it takes at least 50 minutes; among these, the winding and transfer time is relatively long, and many factories need to separate the factory that completes the carbon coating from the factory that completes the electrode paste coating. The time consumed during the transportation of the aluminum foil is at least 30 minutes.

[0137] D20: The aluminum foil that has completed the double-sided carbon coating process is sequentially fed into the second aluminum foil unwinding mechanism 41, the first side electrode paste coating mechanism, the third aluminum foil oven, the second side electrode paste coating mechanism, the fourth aluminum foil oven, and the second aluminum foil winding mechanism 45, thereby completing the double-sided electrode paste coating process of the aluminum foil.

[0138] Specifically, in the relevant technology, the electrode slurry coating speed is 40 meters per minute, the drying time of the first side of the aluminum foil in the first aluminum foil drying oven ranges from 2 minutes to 4 minutes, and the drying time of the second side of the aluminum foil in the second aluminum foil drying oven ranges from 2 minutes to 4 minutes.

[0139] As can be seen from the above, in Comparative Example 1, the carbon layer coating process and the electrode paste coating process are completed separately; the time for completing the carbon layer coating process on both sides of the aluminum foil includes:

[0140] The time required for the double-sided carbon coating process and the double-sided electrode slurry coating process of the aluminum foil includes: the time for coating the first carbon layer of the aluminum foil, the time for drying the carbon coating slurry on the first side of the aluminum foil, the time for drying the carbon coating slurry on the second side of the aluminum foil, the time for transporting the aluminum foil with double-sided carbon coating from the carbon coating plant to the electrode slurry coating plant, the time for coating the electrode slurry on the first side of the aluminum foil, the time for drying the electrode slurry on the first side of the aluminum foil, the time for coating the electrode slurry on the second side of the aluminum foil, and the time for drying the electrode slurry on the second side of the aluminum foil. Specifically, in related technologies, the double-sided carbon coating process and the double-sided electrode slurry coating process of the aluminum foil require at least 330 minutes.

[0141] By comparison, it can be seen that in the battery aluminum foil coating method provided in the embodiment, the aluminum foil sequentially passes through the unwinding mechanism, the double-sided carbon layer coating mechanism 421, the drying mechanism, the first side coating mechanism 431, the first drying oven 432, the second side coating mechanism 441, the second drying oven 442, and the winding mechanism 45. This allows the aluminum foil to be coated on both sides with only one unwinding and one winding, effectively reducing the complexity of the operation, avoiding manual handling of the aluminum foil material, and saving manpower. Furthermore, by integrating the carbon layer coating process and the motor slurry coating process into a single production line, the time required to transport the double-sided carbon layer coated aluminum foil from the carbon layer coating plant to the electrode slurry coating plant is saved, while production costs are greatly reduced, the production cycle is shortened, resource waste is reduced, and land space is saved.

[0142] Please refer to Figure 8, which is a schematic diagram of the current collector structure provided in an embodiment of this application.

[0143] This application embodiment also provides a current collector 5, which includes an aluminum foil, and the aluminum foil can be manufactured using the above-described battery aluminum foil coating method.

[0144] Specifically, the current collector 5 includes a metal layer 53 and a coating layer 51 disposed on both sides of the metal layer 53; wherein, the metal layer 53 may be an aluminum foil, and the coating layer 51 includes a carbon coating layer 5111 and an electrode layer 5112 stacked together, and the coating layer 51 may be coated onto the aluminum foil using the above-described battery aluminum foil coating method; it should be noted that the battery aluminum foil coating method has been described in detail in the above embodiments, and will not be repeated here.

[0145] It is understood that the current collector 5 adopts a double-sided coating process of carbon coating slurry and electrode slurry, which can significantly improve the conductivity of the aluminum foil surface. Among them, the addition of carbon coating layer 5111 provides the current collector with excellent static conductivity, which can more effectively collect the micro-current generated in the electrode material and improve the conductivity of the battery. This has a positive effect on the charge and discharge efficiency, cycle life and overall battery performance. In addition, the solvent system of carbon coating slurry is different from that of electrode slurry, which improves the flexibility of material selection, so that the process is no longer limited to using materials of the same system. This helps to develop battery structures that are more adaptable to various application scenarios and expands the application scope of the technology.

[0146] Please refer to Figures 8 and 9; Figure 9 is a schematic diagram of the battery structure provided in the embodiment of this application.

[0147] This embodiment also provides a battery 6, which includes a positive electrode 61 and a negative electrode 62. The positive electrode 61 includes a positive current collector and a positive active material, and the negative electrode 6 includes a negative current collector. At least one of the positive current collector and the negative current collector can be the current collector described in any of the above embodiments.

[0148] Specifically, the battery 6 includes a positive electrode 61, a negative electrode 62, and a separator 63 disposed between the positive electrode 61 and the negative electrode 62; wherein the positive electrode, the negative electrode 62, and the separator 63 may be stacked cells or wound cells, and the battery 6 includes, but is not limited to, a pouch battery, a square battery, or a cylindrical battery.

[0149] It should be noted that this embodiment uses the positive electrode slurry as an example to illustrate the technical solution of this application. That is, in this embodiment, the positive electrode current collector is the current collector described in any of the above embodiments.

[0150] It is understood that the current collector can serve as a core component of the positive and negative electrodes in the battery, directly affecting the battery's charge and discharge performance, energy density, and cycle life. In this embodiment, by applying carbon coating slurry and electrode slurry to both sides, the conductivity and mechanical properties of the current collector can be greatly improved, thereby providing more stable and efficient support for the battery and thus improving the overall performance of the battery.

Claims

1. A battery aluminum foil coating apparatus, wherein, include: Unwinding mechanism, used for unwinding aluminum foil; A double-sided coating assembly is used to first coat a carbon coating slurry on the first side of an aluminum foil, then coat a carbon coating slurry on the second side of the aluminum foil, and finally dry the first and second sides of the coated aluminum foil simultaneously. The first coating assembly is used to sequentially coat the electrode paste and the ceramic insulating paste on the first surface of the aluminum foil, and to dry the first surface of the coated aluminum foil. The second coating assembly is used to sequentially coat the electrode paste and the ceramic insulating paste on the second side of the aluminum foil, and to dry the second side of the coated aluminum foil. A winding mechanism for winding up coated aluminum foil; The aluminum foil is sequentially passed through the unwinding mechanism, the double-sided coating assembly, the first-sided coating assembly, the second-sided coating assembly, and the winding mechanism to complete the double-sided coating.

2. The battery aluminum foil coating apparatus according to claim 1, wherein, The double-sided coating assembly is located between the unwinding mechanism and the first-sided coating assembly, and the double-sided coating assembly includes a double-sided carbon layer coating mechanism and a drying mechanism connected in sequence. The first side coating assembly is located between the double-sided coating assembly and the second side coating assembly. The first side coating assembly includes a first side coating mechanism and a first oven connected in sequence. The second side coating assembly includes a second side coating mechanism and a second oven connected in sequence.

3. The battery aluminum foil coating apparatus according to claim 2, wherein, The first coating mechanism is used to sequentially coat the electrode paste and the ceramic insulating paste on the first surface of the aluminum foil, and the first drying oven is used to dry the first surface of the coated aluminum foil. The second coating mechanism is used to sequentially coat the electrode paste and the ceramic insulating paste on the second side of the aluminum foil, and the second oven is used to dry the second side of the coated aluminum foil.

4. The battery aluminum foil coating apparatus according to claim 2, wherein, The double-sided carbon layer coating mechanism includes: Frame; The first carbon layer coating mechanism is used to coat the first surface of the aluminum foil with a carbon layer slurry; The second carbon coating mechanism is used to coat the second side of the aluminum foil with a carbon coating paste; The first carbon layer coating mechanism and the second carbon layer coating mechanism are both located within the frame, and the aluminum foil passes through the first carbon layer coating mechanism and the second carbon layer coating mechanism in sequence.

5. The battery aluminum foil coating apparatus according to claim 2, wherein, The battery aluminum foil coating apparatus further includes a web-correcting mechanism, which is disposed between the unwinding mechanism and the double-sided coating assembly; And / or, the correction mechanism is disposed between the drying mechanism and the first surface coating mechanism; And / or, the correction mechanism is disposed between the first oven and the second surface coating mechanism; And / or, the correction mechanism is disposed between the second drying oven and the winding mechanism.

6. The battery aluminum foil coating apparatus according to claim 2, wherein, The drying mechanism is located between the double-sided carbon layer coating mechanism and the first-sided coating mechanism, and the heat source of the drying mechanism is at least one of steam, electric heater, infrared, and microwave.

7. The battery aluminum foil coating apparatus according to claim 6, wherein, The drying mechanism includes an oven and multiple infrared heating elements located inside the oven, with the multiple infrared heating elements respectively installed at the top and bottom of the oven.

8. A method for coating aluminum foil for batteries, wherein, The coating method for the battery aluminum foil includes at least the following steps: After the aluminum foil roll is unwound by the unwinding mechanism, it is fed into the double-sided coating assembly. Aluminum foil enters the double-sided coating assembly, where a carbon coating slurry is first applied to the first side of the aluminum foil, and then a carbon coating slurry is applied to the second side of the aluminum foil. After that, the first and second sides of the coated aluminum foil are dried simultaneously, and finally the aluminum foil with the carbon coating completed is sent to the first-sided coating assembly. The aluminum foil enters the first coating assembly, where electrode paste and ceramic insulating paste are sequentially coated on the first surface of the aluminum foil after the carbon coating layer has been applied. The first surface of the aluminum foil after the electrode paste has been applied is then dried, and the aluminum foil is then sent to the second coating assembly. The aluminum foil enters the second side coating assembly, where electrode paste and ceramic insulating paste are sequentially coated on the second side of the aluminum foil after the carbon coating layer has been applied. The second side of the aluminum foil after the electrode paste is applied is then dried, and the aluminum foil is then fed into the winding mechanism. The aluminum foil is wound up by a winding mechanism to complete the coating process.

9. The coating method according to claim 8, wherein, The aluminum foil enters a double-sided coating assembly, where a carbon coating slurry is first applied to the first side of the aluminum foil, and then a carbon coating slurry is applied to the second side of the aluminum foil. The first and second sides of the coated aluminum foil are then dried simultaneously. Finally, the aluminum foil is guided into the first-side coating assembly via guide rollers. The aluminum foil enters the first carbon layer coating mechanism, where a carbon layer slurry is coated on the first surface of the aluminum foil, and then the aluminum foil is fed into the second carbon layer coating mechanism. The aluminum foil enters the second carbon layer coating mechanism, where a carbon layer slurry is applied to the second side of the aluminum foil, and then the aluminum foil is sent to the drying mechanism. The aluminum foil enters the drying mechanism, which simultaneously dries the first and second sides of the coated aluminum foil. Then, the aluminum foil with the carbon coating completed is sent to the first side coating assembly.

10. The coating method according to claim 9, wherein, The aluminum foil enters the first surface coating assembly, where electrode paste and ceramic insulating paste are sequentially coated on the first surface of the aluminum foil after the carbon coating layer has been applied. The first surface of the aluminum foil after the electrode paste coating is applied is then dried. The aluminum foil is then fed into the second surface coating assembly. The aluminum foil enters the first coating mechanism, where electrode paste and ceramic insulating paste are sequentially coated on the first surface of the aluminum foil after the carbon coating layer has been applied. The aluminum foil is then sent into the first drying oven. The aluminum foil enters the first drying oven, where the first side of the coated aluminum foil is dried, and then the aluminum foil is sent to the second side coating assembly.

11. The coating method according to claim 10, wherein, The aluminum foil enters the second-side coating assembly, where electrode paste and ceramic insulating paste are sequentially coated onto the second side of the aluminum foil after the carbon coating layer has been applied. The second side of the aluminum foil after the electrode paste coating is applied is then dried. Finally, the aluminum foil is fed into the winding mechanism. The aluminum foil enters the second coating mechanism, where electrode paste and ceramic insulating paste are sequentially coated on the second surface of the aluminum foil after the carbon coating layer has been applied. The aluminum foil is then sent into the second oven. The aluminum foil enters the second drying oven, where the second side of the coated aluminum foil is dried, and then the aluminum foil is fed into the winding mechanism.

12. The coating method according to claim 11, wherein, The drying temperature of the drying mechanism is greater than or equal to 70 degrees Celsius and less than or equal to 170 degrees Celsius, and the drying time of the drying mechanism is greater than or equal to 3 seconds and less than or equal to 9 seconds. The drying temperature of the first oven is greater than or equal to 85 degrees Celsius and less than or equal to 105 degrees Celsius, and the drying time of the aluminum foil in the first oven is greater than or equal to 2 minutes and less than or equal to 4 minutes. The drying temperature of the second oven is greater than or equal to 90 degrees Celsius and less than or equal to 115 degrees Celsius, and the drying time of the aluminum foil in the second oven is greater than or equal to 2 minutes and less than or equal to 4 minutes.

13. The coating method according to claim 8, wherein, The solvent system of the carbon coating slurry is different from that of the electrode slurry.

14. The coating method according to claim 8, wherein, The solvent system of the ceramic insulating paste is the same as that of the electrode paste.

15. The coating method according to claim 8, wherein, The electrode paste includes active materials, binders, dispersants, conductive agents, and organic solvents; The active material is lithium iron phosphate, the binder is polyvinylidene fluoride, the dispersant is YTF003 dispersant, the conductive agent is carbon nanotubes, and the organic solvent is N-methylpyrrolidone.

16. The coating method according to claim 8, characterized in that, The carbon coating slurry is coated by gravure transfer coating, and the electrode slurry is coated by one of transfer coating, extrusion coating, or wet coating.

17. The coating method according to claim 8, characterized in that, The viscosity range of the electrode paste is greater than or equal to 5000 mPa·s and less than or equal to 25000 mPa·s, and the viscosity range of the ceramic insulating paste is greater than or equal to 1000 mPa·s and less than or equal to 7000 mPa·s. The solid content of the electrode paste is greater than or equal to 60% and less than or equal to 70%, and the solid content of the ceramic insulating paste is greater than or equal to 30% and less than or equal to 38%.

18. A current collector, wherein, Includes aluminum foil, said aluminum foil being manufactured using the coating method for battery aluminum foil as described in any one of claims 8 to 17.

19. The current collector according to claim 18, characterized in that, The current collector includes a metal layer and a coating layer disposed on both sides of the metal layer; wherein the metal layer is the aluminum foil, and the coating layer includes a carbon coating layer and an electrode layer stacked together.

20. A battery, wherein, The device includes a positive electrode and a negative electrode, wherein the positive electrode includes a positive current collector and a positive active material, and the negative electrode includes a negative current collector; wherein at least one of the positive current collector and the negative current collector is a current collector as described in any one of claims 18 to 19.

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