Coating device

Abstract

Coating device, characterized in that it comprises the following: a corona unit and a coating unit, arranged sequentially along a conveying direction of a film; wherein the corona unit comprises a discharge section facing a surface of the film and configured to perform corona treatment on the surface of the film; and wherein the coating unit includes a coating nozzle configured to apply a slurry to the surface of the film after corona treatment.

Description

CROSS-REFERENCE TO RELATED REGISTRATIONS

[0001] This application claims priority over Chinese patent application No. CN202322360587.4 entitled “Coating Device”, filed with the Chinese Patent Office on August 31, 2023, the entire contents of which are incorporated into this document by reference. TECHNICAL AREA

[0002] The present application relates to the field of lithium battery manufacturing technology and in particular to a coating device. BACKGROUND

[0003] The quality of lithium-ion batteries is crucial for the quality and safety of new energy vehicles. In the production process of solid-state lithium-ion batteries, electrode plate coating is a critical step, and extrusion coating is one of the most commonly used methods. As the demand for higher battery cell performance and cost reduction continues to grow, the development of multi-layer composite coatings has become a new trend in solid-state battery manufacturing. Currently, composite coating is primarily achieved by applying a carbon coating to the current collector film in combination with a two-layer extrusion coating die to simultaneously coat the upper and lower layers of the slurry.

[0004] In the current lithium battery manufacturing process, current collector films pre-coated with a carbon primer layer are typically used as the raw material prior to the main coating process to enhance electrode plate adhesion and electrochemical performance. However, sourcing carbon-coated films presents challenges such as high raw material costs and unstable supply cycles. Furthermore, the existing multi-layer coating process, which involves applying a primer layer to the current collector followed by the main slurry coating, requires two separate production equipment: engraving and extrusion. The commonly used extrusion coating process also lacks the integrated capability of combining primer coating and extrusion in a single step.Furthermore, performing engraving coating and extrusion coating in two separate processes has disadvantages in terms of equipment investment costs, required factory floor space, and production efficiency. SUMMARY

[0005] In light of the foregoing, the present application proposes a coating device capable of removing oil contaminants from the surface of a film, increasing the dyn value of the surface of the film, and also facilitating the production of an electrode plate with excellent performance.

[0006] In a first aspect, the present application provides a coating device comprising a corona unit and a coating unit arranged sequentially along a conveying direction of a film; the corona unit includes a discharge section facing a surface of the film and configured to perform a corona treatment on the surface of the film; the coating unit includes a coating nozzle configured to apply a slurry to the surface of the film after the corona treatment.

[0007] Advantageous effects: By placing the corona unit upstream of the coating unit, the film surface can undergo corona treatment prior to coating. This removes oil contaminants from the film surface and increases the surface tension coefficient (Dyn value). Consequently, an electrode plate with excellent performance can be produced, resulting in superior active material adhesion and thus extending battery lifespan. Simultaneously, procurement costs can be reduced by eliminating the need to purchase a film with a carbon primer layer, while still providing a significant benefit.

[0008] In an optional embodiment, the corona unit includes a housing with a foil inlet and a foil outlet; and the discharge section is arranged inside the housing and includes a first discharge section configured to perform corona treatment on an A-side of the foil, and a second discharge section configured to perform corona treatment on a B-side of the foil.

[0009] Advantageous effects: The provided first discharge section and second discharge section can each perform corona treatment on the A-side and B-side of the film, which is advantageous for a subsequent improvement of the coating quality of the A-side and B-side of the film.

[0010] In an optional embodiment, a plurality of conveying rollers, around which the film can be guided, are arranged inside the housing; the first discharge section and the second discharge section are each arranged on different conveying rollers corresponding to the film, and the first discharge section and the second discharge section each have an arc-shaped surface profile that is adapted to an outer circumferential surface of a corresponding conveying roller.

[0011] Advantageous effects: The first discharge section and the second discharge section each have an arc-shaped surface profile that can better match the film wrapped around the outer circumferential surface of the conveyor roller, is advantageous for the corona treatment of the film, and also facilitates the arrangement of the first discharge section and the second discharge section.

[0012] In an optional embodiment, a distance h between each of the arc-shaped surface profiles and the outer circumferential surface of the corresponding conveyor rollers satisfies: 5 mm ≤ h ≤ 10 mm.

[0013] Advantageous effects: Setting a distance between each of the arc-shaped surface profiles and the outer circumferential surface of the corresponding conveyor roller is advantageous to ensure the corona treatment effect of the film.

[0014] In an optional embodiment, the housing is provided with a gas inlet for introducing inert gas and an outlet for removing impurities generated during corona treatment, and a vacuum blower is connected to the outlet.

[0015] Advantageous effects: The provided gas inlet for introducing inert gas is advantageous for preventing contact between oxygen and the film surface during corona treatment. The provided outlet can facilitate the removal of contaminants during corona treatment.

[0016] In an optional embodiment, a film unwinding unit is arranged upstream of the corona unit and configured to unwind the film to be coated.

[0017] Advantageous effects: The provided unwinding unit allows the film to be unwound.

[0018] In an optional embodiment, a heating unit and a winding unit are arranged sequentially downstream of the coating unit, the heating unit being configured to heat the film coated with the slurry, and the winding unit being configured to wind up the heated film.

[0019] Advantageous effects: The provided heating unit is configured to heat the film coated with the slurry, and the provided winding unit is configured to wind the heated film. The arrangement of the unwinding unit, the heating unit, and the winding unit is advantageous for the coating efficiency of the film.

[0020] In an optional embodiment, the coating nozzle includes an A-side coating nozzle configured to apply the slurry to the A-side of the film, and a B-side coating nozzle configured to apply the slurry to the B-side of the film.

[0021] Advantageous effects: The coating nozzle of side A and the coating nozzle of side B can each apply the slurry to side A and side B of the film.

[0022] In an optional embodiment, the coating nozzle of side A and / or the coating nozzle of side B have a plurality of coating lips.

[0023] Advantageous effects: The multitude of coating lips provided on the A-side coating nozzle and the B-side coating nozzle can perform a multi-layer coating on the surface of the film.

[0024] In an optional embodiment, there is a plurality of coating nozzles on the A-side and / or a plurality of coating nozzles on the B-side, which are arranged spaced apart from each other.

[0025] Advantageous effects: The coating nozzles, which are spaced apart from each other, can improve the coverage area of ​​the coating, thereby improving coating efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more clearly illustrate the technical solutions in the embodiments of the present application or in the prior art, the accompanying drawings, which are necessary for describing the embodiments or the prior art, are briefly presented below. Obviously, the accompanying drawings illustrate only some embodiments of the present application in the following description. A person skilled in the art can derive other drawings from these accompanying drawings without any creative effort. Fig. Figure 1 is a schematic structural representation of a coating device according to an embodiment of the present application; Fig. 2 is a schematic structural representation of a corona unit and a coating unit according to an embodiment of the present application; Fig. 3 is an enlarged structural representation of a corona unit according to an embodiment of the present application; and Fig. Figure 4 is a schematic structural representation of a coating unit according to an embodiment of the present application. Description of the reference symbols: 1 unwinding unit; 2 Corona and coating unit; 3 heating units; 4.24a winding unit; 21 cases; 22 first discharge section; 23 second discharge section; 24 Coating nozzle of the B-side; 25 Coating nozzle of the A-side; 211 Gas inlet; 212 Outlet; 220 discharge electrode; 222 Insulating carrier; first coating nozzle; 24b second coating nozzle; 10 slides; 20 vacuum blowers; 30 Ozone treatment units. DETAILED DESCRIPTION OF THE EXECUTION FORMS

[0027] To clarify the objectives, technical solutions, and advantages of the embodiments of the present application, the technical solutions in the embodiments of the present application are described below in detail and in conjunction with the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments that a person skilled in the art can obtain without creative effort are within the scope of protection of the present application.

[0028] This embodiment relates to a coating device that is able to remove oil contaminants from the surface of a film 10, increase the dyn value of the surface of the film 10 and also facilitate the manufacture of an electrode plate with excellent performance.

[0029] With regard to the overall configuration, the coating device of this embodiment includes, with reference to Fig. 1 and Fig. 2 mainly a corona unit and a coating unit, arranged sequentially along a conveying direction of a film 10. The corona unit has a discharge section facing a surface of the film 10, and the discharge section is configured to perform a corona treatment on the surface of the film 10. The coating unit has a coating nozzle configured to apply a slurry to the surface of the film 10 after the corona treatment.

[0030] In the aforementioned structure, the surface of the foil 10 is treated by the corona unit, which is located upstream of the coating unit, before coating is applied. This removes oil contaminants from the surface of the foil 10 and increases its surface tension coefficient (Dyn value). Furthermore, the coating device is also capable of producing electrode plates with excellent performance, ensuring outstanding active material adhesion and thus extending battery lifespan. Simultaneously, procurement costs are reduced by eliminating the need to purchase foil 10 with a carbon primer layer.

[0031] It is understood that the corona unit provided in this embodiment can perform corona treatment on only one side of the film 10, that is, it can perform corona treatment on either side A of the film 10 or side B of the film 10, and then apply a slurry to that side through the coating nozzle in the coating unit. Of course, the corona unit can also perform corona treatment on both sides of the film 10 and, after corona treatment, apply a coating to both sides of the film 10 through the coating nozzle in the coating unit.

[0032] The following is a detailed description of a coating device that performs corona treatment on both sides of the film 10.

[0033] With further reference to Fig. 1 and Fig. 2 includes in the coating device of this embodiment a corona and coating unit 2 in Fig. 1. A corona unit and a coating unit. The corona unit is arranged upstream of the coating unit and includes a housing 21 with an inlet for the film 10 and an outlet for the film 10, and a cavity is formed within the housing 21. The discharge section mentioned above is specifically arranged within the housing 21 and includes a first discharge section 22 configured to perform corona treatment on an A-side of the film 10 and a second discharge section 23 configured to perform corona treatment on a B-side of the film 10. An arrangement of the first discharge section 22 and the second discharge section 23 can each perform corona treatment on the A-side and the B-side of the film 10 and is advantageous for subsequently improving the coating quality of the A-side and the B-side of the film 10.

[0034] In this embodiment, a preferred embodiment is as shown in Fig. Figure 2 shows a plurality of conveying rollers arranged within the housing 21, around which the film 10 can be guided. The first discharge section 22 and the second discharge section 23 are each arranged on different conveying rollers corresponding to the film 10, and each has an arcuate surface profile adapted to the outer circumferential surface of a corresponding conveying roller. The arrangement of the arcuate surface profile allows the discharge section to better conform to the film 10, which is wound around the outer circumferential surface of the conveying roller. This is advantageous for the corona treatment of the film 10 and is also practical for the arrangement of the first discharge section 22 and the second discharge section 23.

[0035] It is understood that, in addition to using the aforementioned structural form in which the film 10 passes successively around a plurality of conveying rollers, the inlet and outlet of the film 10 can also be arranged collinearly. In such a configuration, a conveying roller is arranged at each of the inlet and outlet of the film 10, while conveying rollers may or may not be provided within the housing 21. The first discharge section 22 and the second discharge section 23 are each arranged on opposite sides of the film 10 to perform the corona treatment on both surfaces of the film 10, and such an arrangement is also feasible.

[0036] One preferred embodiment is, as shown in Fig. Figure 3 shows a distance between the arcuate surface profile of the first discharge section 22 and an outer circumferential surface of the corresponding conveyor roller h, and a distance between the arcuate surface profile of the second discharge section 23 and an outer circumferential surface of the corresponding conveyor roller also h, where the distance h satisfies: 5 mm ≤ h ≤ 10 mm. Such a configuration is advantageous to ensure the corona treatment effect of the film 10. In a specific implementation, the distance h can be set to 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, or 10 mm, etc.

[0037] The principle of corona treatment is the use of high-frequency, high-voltage electricity to generate a corona discharge on the surface of the material to be treated, i.e., film 10. During the discharge, low-temperature plasma is generated, leading to free radical reactions on the material's surface, cross-linking of polymers, surface roughening, and increased wettability for polar solvents. This plasma attacks and penetrates the substrate's surface, disrupting its molecular structure. This process oxidizes and polarizes the molecules of the treated surface. The ion bombardment erodes the surface, thereby increasing the material's surface adhesion.

[0038] During the corona treatment process of the film 10, it is necessary to prevent surface oxidation. Additionally, ozone or other contaminants may be generated during the corona treatment process. To facilitate the smooth progress of the corona treatment of the film 10, in this embodiment the housing 21 is provided with a gas inlet 211 for introducing inert gas and an outlet 212 for removing contaminants generated during the corona treatment process. A vacuum blower 20 is connected to the outlet 212. Furthermore, an ozone treatment unit 30 is connected to one end of the vacuum blower 20, located away from the outlet 212. The ozone treatment unit 30 can use activated carbon or a catalytic reduction process to treat the generated ozone.

[0039] At this point during the corona treatment process, the introduced inert gas can effectively prevent contact between oxygen and the surface of the film 10. The negative pressure blower 20, connected to the outlet 212, facilitates the timely removal of impurities during the corona treatment process, thereby improving the corona treatment effect of the film 10.

[0040] In this embodiment, the aforementioned first discharge section 22 and second discharge section 23 can both incorporate a plurality of discharge electrodes 220 in the form of long strips, and the plurality of discharge electrodes 220 in the form of long strips are arranged to form a structure having an arc-shaped surface profile. Furthermore, the first discharge section 22 and the second discharge section 23 are both mounted on an insulating support 222. It should be noted that the circuit connection of the first discharge section 22 and the second discharge section 23, and the structure, which is not mentioned in the corona unit, may refer to the structure of the existing corona treatment machine.

[0041] In this embodiment, an unwinding unit 1 of the film 10 is arranged upstream of the corona unit and is configured to unwind the film 10 to be coated. A heating unit 3 and a winding unit 4 are arranged sequentially downstream of the coating unit; the heating unit 3 is configured to heat the film 10 coated with the slurry, and the winding unit 4 is configured to wind the heated film 10.

[0042] It should be noted that the specific structure of the unwinding unit 1 and the winding unit 4 in this embodiment may be based on the prior art structure, and to ensure the smooth unwinding and winding of the film 10, the unwinding unit 1 and the winding unit 4 may also be equipped with a web edge control, an antistatic mechanism, and a tension control mechanism of the prior art. Furthermore, it should be noted that the specific structure of the heating unit 3 in this embodiment also refers to the prior art structure.

[0043] In this embodiment, the coating nozzle includes an A-side coating nozzle 25 configured to apply a slurry to the A-side of the film 10, and a B-side coating nozzle 24 configured to apply a slurry to the B-side of the film 10. The A-side coating nozzle 25 and the B-side coating nozzle 24 can each apply the slurry to the A-side and B-side of the film 10, respectively.

[0044] As an arrangement form, as in Fig. Figure 2 shows that the coating nozzle 25 of side A and the coating nozzle 24 of side B each have a plurality of coating lips in this embodiment. In this way, a multi-layer coating can be applied to both surfaces of the film 10. It is understood here that, in addition to the above arrangement, either only the coating nozzle 25 of side A or only the coating nozzle 24 of side B can be provided with a plurality of coating lips.

[0045] Another arrangement option, as in Fig.Figure 4 shows a plurality of coating nozzles 25 on side A and a plurality of coating nozzles 24 on side B, spaced apart from one another. Specifically, a first coating nozzle 24a and a second coating nozzle 24b are spaced apart from one another along the conveying direction of the film 10. The first coating nozzle 24a has one coating lip and the second coating nozzle 24b has two coating lips, so that a three-layer slurry coating can be applied to both surfaces of the film 10.

[0046] It should be noted that either multiple coating nozzles 25 on side A are provided, spaced apart from one another, or multiple coating nozzles 24 on side B are provided, spaced apart from one another. The number of coating lips on the coating nozzle can be adjusted as required. Furthermore, it should also be noted that the structures of the coating nozzle 25 on side A and the coating nozzle 24 on side B may specifically refer to the prior art.

[0047] Furthermore, during the coating process of the film 10, in order to ensure the coating quality, thickness measuring mechanisms are provided both upstream of the corona and downstream of the coating to measure the thickness of the film 10 before and after coating, thus facilitating the assurance of the quality of the coating material and the uniformity of the surface density.

[0048] When the coating device of this embodiment is used specifically, the film 10 is unwound by the unwinding unit 1, the conveyed film 10 passes successively through the first discharge section 22 and the second discharge section 23 to perform corona treatment successively on the A-side and the B-side of the film 10, then passes successively through the coating nozzle 24 of the B-side and the coating nozzle 25 of the A-side to perform a multi-layer coating successively on the B-side and the A-side of the film 10. Then, heating is carried out by a heating device for drying, and winding is performed after completion of drying.

[0049] The coating device of this embodiment can form and coat an electrode plate with excellent performance by providing the corona unit upstream of the coating unit. This imparts excellent active material adhesion to the electrode plate, thereby extending the service life of batteries. At the same time, procurement costs can be reduced by eliminating the need to purchase the foil 10 with a carbon primer layer, and it also helps to enhance the active material adhesion in the bottom layer of multilayer coatings.

[0050] Although embodiments of the present application have been described in connection with the drawings, a person skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations are all within the scope defined by the attached claims. Industrial applicability

[0051] By providing a corona unit upstream of a coating unit, the foil surface can undergo corona treatment prior to coating. This removes oil contaminants from the foil surface and increases the surface tension coefficient (Dyn value). Consequently, an electrode plate with excellent performance can be formed and coated, resulting in superior active material adhesion and thus extending battery life. Simultaneously, procurement costs are reduced by eliminating the need to purchase a foil with a carbon primer layer, and this also helps to enhance active material adhesion in the bottom layer of multilayer coatings. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CN 202322360587.4

[0001]

Claims

[1] Coating device, characterized by that it includes the following: a corona unit and a coating unit, arranged sequentially along a conveying direction of a film; wherein the corona unit comprises a discharge section facing a surface of the film and configured to perform corona treatment on the surface of the film; and wherein the coating unit includes a coating nozzle configured to apply a slurry to the surface of the film after corona treatment. [2] Coating device according to claim 1, characterized by , that: the corona unit comprises a housing with a foil inlet and a foil outlet; and the discharge section is located inside the housing and the discharge section includes a first discharge section configured to to perform a corona treatment on an A-side of the film, and includes a second discharge section configured to perform a corona treatment on a B-side of the film. [3] Coating device according to claim 2, characterized by , that: a large number of conveyor rollers are arranged inside the housing, around which the film can be guided; the first discharge section and the second discharge section are each arranged on different conveyor rollers corresponding to the film, and the first discharge section and the second discharge section each have an arc-shaped surface profile that is adapted to an outer circumferential surface of a corresponding conveyor roller. [4] Coating device according to claim 3, characterized by , that: A distance h between each of the arc-shaped surface profiles and the outer circumferential surface of the corresponding conveyor roller satisfies the following: 5 mm ≤ h ≤ 10 mm. [5] Coating device according to claim 2, characterized by , that: the housing is provided with a gas inlet for introducing inert gas and an outlet for removing impurities generated during corona treatment, the outlet being connected to a vacuum blower. [6] Coating device according to claim 1, characterized by , that: A winding unit is arranged upstream of the corona unit and is configured to unwind the film to be coated. [7] Coating device according to claim 1, characterized by , that: a heating unit and a winding unit are arranged sequentially downstream of the coating unit, the heating unit being configured to heat the film coated with the slurry and the winding unit being configured to wind up the heated film. [8] Coating device according to any one of claims 1 to 7, characterized by , that: The coating nozzle comprises an A-side coating nozzle configured to apply a slurry to an A-side of the film and a B-side coating nozzle configured to apply a slurry to a B-side of the film. [9] Coating device according to claim 8, characterized by , that: The coating nozzle of side A and / or the coating nozzle of side B has / have a multitude of coating lips. [10] Coating device according to claim 8, characterized by , that: a large number of coating nozzles on the A-side and / or a large number of coating nozzles on the B-side are provided, spaced apart from each other.

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