A method of encapsulation and a battery

Abstract

The application provides a film coating method and a battery, and relates to the technical field of batteries. The film coating method coats a battery by using a first film body with a first release film attached to a first insulating layer and a second film body with a second adhesive layer and a second insulating layer exposed. The battery has a top surface, a bottom surface, two opposite first side surfaces and two second side surfaces opposite in the thickness direction, and a top cover of the battery is arranged on the top surface. The film coating method comprises the following steps: after the welding of the top cover is completed and the pre-charging air pressure of the battery is completed, the first film body is attached to the two second side surfaces to obtain a first intermediate product. After the first intermediate product is subjected to liquid injection, formation, vacuum injection and sealing nail welding, the first release film is torn off to obtain a second intermediate product. The second film body is attached to the first side surface of the second intermediate product, and the coating is completed. The battery provided by the application is made by the above film coating method. The film coating method and the battery provided by the application can improve the problem of reduced film coating yield.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more specifically, to a coating method and a battery. Background Technology

[0002] Currently, lithium-ion power batteries are generally coated due to factors such as appearance and safety.

[0003] However, in existing technologies, for battery models with thinner walls, vacuuming and electrolyte injection can worsen the flatness or contour of the battery's outer surface, making it prone to defects such as bubbles or wrinkles during coating, thus reducing the coating yield. Furthermore, subsequent processes such as electrolyte injection and formation can easily lead to contamination and damage to the coating, further reducing the battery coating yield. Summary of the Invention

[0004] The present invention aims to provide a coating method that can improve the problem of reduced coating yield caused by poor flatness or contour of the outer surface of the battery in the prior art, and to improve the problem of reduced yield caused by contamination and damage to the coating.

[0005] The present invention also aims to provide a battery that can improve the problem of reduced coating yield caused by poor flatness or contour of the outer surface of the battery in the prior art, and improve the problem of reduced yield caused by contamination and damage to the coating.

[0006] The embodiments of the present invention can be implemented as follows:

[0007] An embodiment of the present invention provides a coating method for coating a battery using a first film and a second film. The first film includes a first composite film and a first release film stacked sequentially, the first release film being adhered to a first insulating layer of the first composite film, and a first adhesive layer exposed on the side of the first composite film away from the first release film. The second film includes a second composite film, one side of the second composite film exposing a second adhesive layer, and the other side exposing a second insulating layer. The battery has a top surface, a bottom surface, two opposing first side surfaces, and two opposing second side surfaces along its thickness direction, and a top cover of the battery is disposed on the top surface. The coating method includes:

[0008] After the welding of the top cover is completed and the pre-charge pressure of the battery is completed, the first membrane is attached to the two second sides to obtain the first intermediate product.

[0009] After completing the liquid injection, formation, vacuum liquid injection and sealing nail welding of the first intermediate product, the first release film is removed to obtain the second intermediate product.

[0010] The second membrane is attached to the first side of the second intermediate product to complete the encapsulation.

[0011] Optionally, after completing the welding of the top cover and the pre-charge pressure of the battery, the step of attaching the first membrane to the two second sides to obtain the first intermediate product includes:

[0012] The first membrane is attached to at least a portion of the bottom surface and the two second side surfaces to obtain the first intermediate product.

[0013] Optionally, the first membrane is attached to a portion of the top surface to form an edge.

[0014] Optionally, the second film is attached to the first side of the second intermediate product to complete the encapsulation step, which includes:

[0015] Two second membranes are respectively attached to the two first sides.

[0016] Optionally, the second membrane body covers a portion of the second side surface to form an edge, and overlaps with the first membrane body on the second side surface;

[0017] And / or, the first membrane body covers a portion of the first side surface to form an edge, and overlaps with the second membrane body on the first side surface.

[0018] Optionally, after completing the welding of the top cover and the pre-charge pressure of the battery, the step of attaching the first membrane to the two second sides to obtain the first intermediate product includes:

[0019] The first intermediate product is obtained by attaching two first membranes to the two second sides respectively.

[0020] Optionally, the first membrane body is attached to a portion of the top surface to form an edge.

[0021] Optionally, the second film is attached to the first side of the second intermediate product to complete the encapsulation step, which includes:

[0022] The second membrane is attached to the bottom surface and the two first side surfaces.

[0023] Optionally, the second membrane body covers a portion of the second side surface to form an edge, and overlaps with the first membrane body;

[0024] And / or, the first membrane body covers a portion of the first side surface to form an edge, and overlaps with the second membrane body.

[0025] Optionally, the first film further includes a second release film, which is attached to the outside of the first adhesive layer of the first composite film.

[0026] Before the step of attaching the first membrane to the two second sides to obtain the first intermediate product after completing the welding of the top cover and the pre-charge pressure of the battery, the coating method further includes:

[0027] Remove the second release film.

[0028] Optionally, the second membrane further includes a third release film, which is attached to the outside of the second adhesive layer of the second composite membrane;

[0029] Before the step of attaching the second film to the first side of the second intermediate product to complete the coating, the coating method further includes:

[0030] Remove the third release film.

[0031] A battery is manufactured using the coating method described above.

[0032] The advantages of the coating method and battery provided by this invention compared to the prior art include:

[0033] After the top cover welding and battery pre-charge pressure are completed, the flatness or contour of the second side of the battery is good, which facilitates the adhesion of the first film to the two second sides of the battery in the thickness direction. This prevents air bubbles or wrinkles from forming during the first film adhesion process, improving the adhesion yield of the first film. Furthermore, since a first release film is provided on the first film to protect the first insulating layer, it provides protection for the first insulating layer during battery electrolyte injection, formation, vacuuming, and sealing pin welding, preventing contamination and damage to the first insulating layer, thus preventing damage to the first film. After completing the battery electrolyte injection, formation, vacuuming, and sealing pin welding processes, the film on the narrower first side is then applied, resulting in a more complete battery coating and improved coating yield. Therefore, this coating method and battery can improve the problem of reduced coating yield caused by poor flatness or contour of the battery's outer surface in existing technologies, as well as the problem of reduced yield caused by film contamination and damage. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure of the first membrane provided in some embodiments of this application;

[0036] Figure 2 This is a schematic diagram of the structure of the second membrane provided in some embodiments of this application;

[0037] Figure 3 This is a schematic diagram of the structure of the first membrane provided in some other embodiments of this application;

[0038] Figure 4 This is a schematic diagram of the structure of the second membrane provided in some other embodiments of this application;

[0039] Figure 5 This is a schematic diagram of the battery structure provided in the embodiments of this application;

[0040] Figure 6 This is a flowchart of the coating method provided in the embodiments of this application;

[0041] Figure 7 This is a flowchart illustrating the coating method provided in some embodiments of this application;

[0042] Figure 8 This is a flowchart illustrating the coating method provided in other embodiments of this application.

[0043] Icons: 10-Battery; 11-Top surface; 12-Bottom surface; 13-First side surface; 14-Second side surface; 100-First film; 110-First composite film; 111-First adhesive layer; 112-First insulating layer; 120-First release film; 130-Second release film; 200-Second film; 210-Second composite film; 211-Second adhesive layer; 212-Second insulating layer; 220-Third release film. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0045] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0046] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0047] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, 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, and therefore should not be construed as a limitation of this invention.

[0048] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0049] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0050] The embodiments of this application provide a coating method for coating the outside of a battery 10, which can improve the problem of reduced coating yield caused by poor flatness or contour of the outer surface of the battery 10 in the prior art, and improve the problem of reduced yield caused by contamination and damage to the film.

[0051] Please refer to the following: Figure 1 and Figure 2 In the embodiments of this application, the coating method employs a first film 100 and a second film 200. The first film 100 includes a first composite film 110 and a first release film 120. The first composite film 110 is formed by alternating layers of at least one first adhesive layer 111 and at least one first insulating layer 112, such that one side of the first composite film 110 exposes the first adhesive layer 111 and the other side exposes the first insulating layer 112. The first release film 120 is adhered to the exposed first insulating layer 112. It is worth noting that the first release film 120 can be peeled off from the first insulating layer 112 to expose the first insulating layer 112. In other embodiments, the first insulating layer 112 may also be referred to as a substrate layer. The second membrane 200 includes a second composite membrane 210, which is also formed by alternating layers of at least one second adhesive layer 211 and at least one second insulating layer 212, such that one side of the second composite membrane 210 exposes the second adhesive layer 211 and the other side exposes the second insulating layer 212.

[0052] It should be noted that, in some embodiments of this application, the first film 100, before use, has one side exposed with the first adhesive layer 111, allowing it to be adhered to the outer surface of other objects, while the other side exposes the first release film 120; the first release film 120 can be peeled off under external force to expose the first insulating layer 112. Similarly, the second film 200, before use, has one side exposed with the second adhesive layer 211, facilitating its adhesion to the outer surface of other objects, while the other side exposes the second insulating layer 212.

[0053] It should be understood that please refer to the following: Figure 3 and Figure 4 In other embodiments, the first film 100 may further include a second release film 130, which is adhered to the first adhesive layer 111 of the first composite film 110 to protect the first adhesive layer 111. When it is necessary to adhere the first film 100 to the outer surface of other objects, the second release film 130 can simply be peeled off from the first adhesive layer 111. Alternatively, the second film 200 may also include a third release film 220, which is adhered to the second adhesive layer 211 of the second composite film 210 to protect the second adhesive layer 211. When it is necessary to adhere the second film 200 to the outer surface of other objects, the third release film 220 can simply be peeled off.

[0054] In this embodiment, please refer to Figure 5 The outer surface of the battery 10 has a top surface 11, a bottom surface 12, two opposing first side surfaces 13, and two opposing second side surfaces 14 along its thickness direction. The area of ​​the second side surfaces 14 is larger than the area of ​​the first side surfaces 13; the top cover of the battery 10 is disposed on the top surface 11.

[0055] Please see Figure 6 Based on the battery 10, the first membrane 100, and the second membrane 200 provided above, the coating method provided in this embodiment includes:

[0056] S1. After completing the welding of the top cover and the pre-charge pressure of the battery 10, the first membrane 100 is attached to the two second side surfaces 14 to obtain the first intermediate product.

[0057] S2. After completing the liquid injection, formation, vacuum liquid injection and sealing nail welding of the first intermediate product, the first release film 120 is removed to obtain the second intermediate product.

[0058] S3. A second membrane 200 is attached to the first side 13 of the second intermediate product to complete the coating.

[0059] After the top cover of the battery 10 is welded, the battery 10 is pre-pressurized. Due to the pressure, the flatness and contour of the outer surface of the battery 10 are better. Based on this, the first film 100 can be preferentially applied to the larger second side 14, improving the coating effect and effectively preventing the formation of bubbles and wrinkles. Simultaneously, because the applied first film 100 has a first release film 120 protecting the first insulating layer 112, it can prevent the first insulating layer 112 from being contaminated or damaged. Therefore, during subsequent processes such as liquid injection, formation, vacuum injection, and welding of sealing pins, the first insulating layer 112 can be effectively protected. After completing the liquid injection, formation, vacuum liquid injection, and sealing nail welding, the second membrane 200 is then applied. Since the areas of the first side 13, top 11, and bottom 12 are small, the flatness and contour have little impact on the film application effect of the first side 13, top 11, and bottom 12. Applying the film to the first side 13, top 11, and bottom 12 after completing the liquid injection, formation, vacuum liquid injection, and sealing nail welding can also achieve good results.

[0060] As described above, after the top cover welding and pre-charging of the battery 10 are completed, the flatness or contour of the second side 14 of the battery 10 is good, which facilitates the adhesion of the first film 100 to the two second side 14 in the thickness direction of the battery 10. This prevents air bubbles or wrinkles from forming during the adhesion process of the first film 100, thus improving the adhesion yield of the first film 100. In addition, since a first release film 120 is provided on the first film 100 to protect the first insulating layer 112 on the first film 100, it can provide protection for the first insulating layer 112 during the battery 10's liquid injection, formation, vacuuming, and sealing pin welding processes, preventing the first insulating layer 112 from being contaminated or damaged, thereby preventing damage to the first film 100. After completing the battery 10's liquid injection, formation, vacuuming, and sealing pin welding processes, the film on the narrower first side 13 can be applied, resulting in a more complete encapsulation of the battery 10 and improving the encapsulation yield. Based on this, the coating method and the battery 10 can achieve the goal of improving the problem of reduced coating yield caused by poor flatness or contour of the outer surface of the battery 10 in the prior art, and improving the problem of reduced yield caused by contamination and damage to the film.

[0061] Optionally, please refer to Figure 7 In some embodiments of this application, step S1 includes:

[0062] S11. The first membrane 100 is attached to at least part of the bottom surface 12 and the two second side surfaces 14 to obtain the first intermediate product.

[0063] In other words, when the first film 100 is attached to the two second side surfaces 14 and at least part of the bottom surface 12, the first film 100 is bent into a U-shape. At this time, the first film 100 provides protection to the two second side surfaces 14 and at least part of the bottom surface 12. Since the first release film 120 on the first film 100 has not been removed, the first release film 120 can protect the first insulating layer 112 on the first composite film 110.

[0064] Optionally, in this embodiment, during the process of attaching the first membrane 100 to the two second side surfaces 14, the first membrane 100 is attached to a portion of the top surface 11 to form an edge. That is, a portion of the first membrane 100 extends beyond the second side surfaces 14, so that a portion of the second side surfaces 14 are attached to a portion of the edge of the top surface 11, covering a portion of the top surface 11. When the second side surface 14 crosses the edge line between the top surface 11 and the second side surface 14, an edge is formed; wherein, the edge refers to covering the corner formed between the two side surfaces, and the edge here is the edge structure formed by the first membrane 100 at the corner between the second side surface 14 and the top surface 11.

[0065] It should be understood that in other embodiments of this application, the edging between the second side surface 14 and the top surface 11 may also be omitted.

[0066] In addition, step S3 includes:

[0067] S31. Two second membranes 200 are respectively attached to the two first sides 13.

[0068] By using two second membranes 200 to cover the two first sides 13, multiple sides of the battery 10 can be covered, thus achieving the coating of the battery 10.

[0069] Optionally, to comprehensively improve the protection of the battery 10, the second film 200 is attached to a portion of the second side 14 to form an edge, and overlaps with the first film 100 on the second side 14. And / or, the first film 100 is attached to a portion of the first side 13 to form an edge, and overlaps with the second film 200 on the first side 13.

[0070] Wherein, and / or refers to the following: the second membrane 200 may only cover a portion of the second side 14 to form a edging, and may overlap with the first membrane 100 on the second side 14; the first membrane 100 may only cover a portion of the first side 13 to form a edging, and may overlap with the second membrane 200 on the first side 13; or the second membrane 200 may cover a portion of the second side 14 to form a edging, and may overlap with the first membrane 100 on the second side 14, and the first membrane 100 may cover a portion of the first side 13 to form a edging, and may overlap with the second membrane 200 on the first side 13.

[0071] It is worth noting that the first membrane 100 being attached to a portion of the first side 13 to form an edge means that a portion of the first membrane 100 extends beyond the second side 14 and crosses the corner between the first side 13 and the second side 14, and is attached to the first side 13. At this time, the portion of the first membrane 100 attached to the corner of the first side 13 and the second side 14 forms an edge structure. At the same time, the first membrane 100 attached to the first side 13 can overlap with the second membrane 200.

[0072] Correspondingly, the phrase "the second membrane 200 is attached to a portion of the second side 14 to form a edging" means that a portion of the second membrane 200 extends beyond the first side 13 and crosses the corner between the first side 13 and the second side 14, and adheres to the second side 14. In this case, the portion of the second membrane 200 adhering to the corner of the first side 13 and the second side 14 forms an edging structure. Simultaneously, the second membrane 200 adhering to the second side 14 can overlap with the first membrane 100.

[0073] Optionally, please refer to Figure 8 In some other embodiments of this application, step S1 may include:

[0074] S12. Two first membrane bodies 100 are respectively attached to two second side surfaces 14 to obtain a first intermediate product.

[0075] In other words, the two second sides 14 are wrapped separately.

[0076] Optionally, in step S12, the first film 100 is attached to a portion of the top surface 11 to form an edge. That is, the first film 100 can also extend beyond the corner between the second side surface 14 and the top surface 11 to be attached to the top surface 11, thereby forming an edge at the corner between the top surface 11 and the second side surface 14. Based on this, the second side surface 14 can be fully covered, or the corner between the second side surface 14 and the top surface 11 can be covered, reducing the possibility of the first film 100 lifting, thereby improving the stability of the first film 100 and increasing the yield of coated products.

[0077] Furthermore, after step S12, step S3 may include:

[0078] S32. The second membrane 200 is attached to the bottom surface 12 and the two first side surfaces 13.

[0079] At this time, the second film 200, which is attached to the bottom surface 12 and the two first side surfaces 13, is U-shaped. It can provide protection to the bottom surface 12 and the two first side surfaces 13 through the second film 200, and thus provide comprehensive protection to the battery 10 through the first film 100 and the second film 200.

[0080] Optionally, the second membrane 200 may be attached to a portion of the second side 14 to form an edge, and may overlap with the first membrane 100. And / or, the first membrane 100 may be attached to a portion of the first side 13 to form an edge, and may overlap with the second membrane 200.

[0081] And / or refers to the following: the second membrane 200 may only cover a portion of the second side 14 to form an edge and overlap with the first membrane 100; the first membrane 100 may only cover a portion of the first side 13 to form an edge and overlap with the second membrane 200; or the second membrane 200 may cover a portion of the second side 14 to form an edge and overlap with the first membrane 100, and the first membrane 100 may cover a portion of the first side 13 to form an edge and overlap with the second membrane 200.

[0082] In the embodiments of the application, if a second release film 130 is disposed on the first film 100, the coating method further includes, before step S1:

[0083] Remove the second release film 130.

[0084] In other words, the second release film 130 needs to be removed to expose the first adhesive layer 111, so that the first film 100 can be attached to the outer surface of the battery 10 through the first adhesive layer 111.

[0085] Similarly, when a third release film 220 is provided on the second film 200, the coating method further includes the following steps before step S1:

[0086] Remove the third release film 220.

[0087] The third release film 220 is peeled off to expose the second insulating layer 212 on the second composite film 210, thereby facilitating the second film 200 to be attached to the outer surface of the battery 10.

[0088] Based on the coating method provided above, this application embodiment also provides a battery 10, which is manufactured using the above coating method. That is, the battery 10 is coated using the above coating method, thereby enabling the battery 10 to also achieve the purpose of improving the problem of reduced coating yield caused by poor flatness or contour of the outer surface of the battery 10 in the prior art, and improving the problem of reduced yield caused by contamination and damage to the film.

[0089] It is worth noting that in other embodiments of this application, the second membrane 200 may also be the first membrane 100 with the first release membrane 120 removed.

[0090] In summary, after the top cover welding and pre-charging of the battery 10 are completed, the flatness or contour of the second side 14 of the battery 10 is good, which facilitates the adhesion of the first film 100 to the two second sides 14 in the thickness direction of the battery 10. This prevents air bubbles or wrinkles from forming during the adhesion process of the first film 100, thus improving the adhesion yield of the first film 100. Furthermore, since a first release film 120 is provided on the first film 100 to protect the first insulating layer 112, it provides protection for the first insulating layer 112 during the battery 10's electrolyte injection, formation, vacuuming, and sealing pin welding processes, preventing contamination or damage to the first insulating layer 112 and thus preventing damage to the first film 100. After completing the electrolyte injection, formation, vacuuming, and sealing pin welding processes of the battery 10, the adhesion of the film to the narrower first side 13 allows for a more complete encapsulation of the battery 10, improving the encapsulation yield. Based on this, the coating method and the battery 10 can achieve the goal of improving the problem of reduced coating yield caused by poor flatness or contour of the outer surface of the battery 10 in the prior art, and improving the problem of reduced yield caused by contamination and damage to the film.

[0091] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A coating method, characterized in that, The battery (10) is encapsulated using a first film (100) and a second film (200); the first film (100) includes a first composite film (110) and a first release film (120) stacked sequentially, the first release film (120) being adhered to the first insulating layer (112) of the first composite film (110), and the first adhesive layer (111) being exposed on the side of the first composite film (110) away from the first release film (120); the second film (200) includes a second composite film. (210), one side of the second composite film (210) exposes the second adhesive layer (211), and the other side exposes the second insulating layer (212); the battery (10) has a top surface (11), a bottom surface (12), two opposing first side surfaces (13), and two opposing second side surfaces (14) along its thickness direction, wherein the area of ​​the second side surface (14) is larger than the area of ​​the first side surface (13), and the top cover of the battery (10) is disposed on the top surface (11); the coating method includes: After the welding of the top cover is completed and the pre-charge pressure of the battery (10) is completed, the first membrane (100) is attached to the two second side surfaces (14) to obtain the first intermediate product. After completing the liquid injection, formation, vacuum liquid injection and sealing nail welding of the first intermediate product, the first release film (120) is removed to obtain the second intermediate product; The second membrane (200) is attached to the first side (13) of the second intermediate product to complete the coating.

2. The coating method according to claim 1, characterized in that, After completing the welding of the top cover and the pre-charge pressure of the battery (10), the step of attaching the first membrane (100) to the two second side surfaces (14) to obtain the first intermediate product includes: The first membrane (100) is attached to at least a portion of the bottom surface (12) and the two second side surfaces (14) to obtain the first intermediate product.

3. The coating method according to claim 2, characterized in that, The first membrane (100) is attached to a portion of the top surface (11) to form an edge.

4. The coating method according to claim 2, characterized in that, The step of attaching the second membrane (200) to the first side (13) of the second intermediate product to complete the encapsulation includes: Two second membranes (200) are respectively attached to the two first sides (13).

5. The coating method according to claim 4, characterized in that, The second membrane (200) covers a portion of the second side surface (14) to form an edge, and overlaps with the first membrane (100) on the second side surface (14); And / or, the first membrane (100) covers a portion of the first side (13) to form an edge and overlaps with the second membrane (200) on the first side (13).

6. The coating method according to claim 1, characterized in that, After completing the welding of the top cover and the pre-charge pressure of the battery (10), the step of attaching the first membrane (100) to the two second side surfaces (14) to obtain the first intermediate product includes: Two first membrane bodies (100) are respectively attached to the two second side surfaces (14) to obtain the first intermediate product.

7. The coating method according to claim 6, characterized in that, The first membrane (100) is attached to a portion of the top surface (11) to form a edging.

8. The coating method according to claim 6, characterized in that, The step of attaching the second membrane (200) to the first side (13) of the second intermediate product to complete the encapsulation includes: The second membrane (200) is attached to the bottom surface (12) and the two first side surfaces (13).

9. The coating method according to claim 8, characterized in that, The second membrane (200) covers a portion of the second side (14) to form an edge and overlaps with the first membrane (100); And / or, the first membrane (100) covers a portion of the first side (13) to form an edge and overlaps with the second membrane (200).

10. The coating method according to any one of claims 1-9, characterized in that, The first membrane (100) further includes a second release film (130), which is attached to the outside of the first adhesive layer (111) of the first composite membrane (110); Before the step of attaching the first membrane (100) to the two second sides (14) after completing the welding of the top cover and the pre-charge pressure of the battery (10) to obtain the first intermediate product, the coating method further includes: Remove the second release film (130).

11. The coating method according to any one of claims 1-9, characterized in that, The second membrane (200) further includes a third release film (220), which is attached to the outside of the second adhesive layer (211) of the second composite membrane (210); Before the step of attaching the second membrane (200) to the first side (13) of the second intermediate product to complete the coating, the coating method further includes: Remove the third release film (220).

12. A battery, characterized in that, It is made by the coating method as described in any one of claims 1-11.

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