Battery case, battery cell, and battery device

Abstract

The utility model discloses a battery shell, battery monomer and battery device, battery shell includes: casing and protective coating. The roughness of casing's outer surface is greater than or equal to Ra0.4, and the protective coating is arranged on the outer surface of the casing and comprises a transition layer and an insulating layer, the transition layer covers the outer surface of the casing, and the insulating layer is arranged on the side of the transition layer away from the casing. According to the battery shell of the utility model embodiment, the casing outer surface of the battery shell is provided with the protective coating with insulation, which can play an insulation protection role and is not easy to fall off.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery casing, a battery cell, and a battery device. Background Technology

[0002] In related technologies, the outer casing of a battery is typically made of metal. To prevent short circuits caused by contact between external conductive materials and the casing, an insulating layer is required to cover its outer surface. In these technologies, a blue film is used as the insulating layer covering the outer surface of the casing; however, this blue film is prone to peeling off, leading to insulation failure. Therefore, improvements are needed. Utility Model Content

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, one objective of the present invention is to provide a battery casing whose outer surface is provided with a protective coating with insulating properties, which can provide insulation and protection and is less prone to peeling off.

[0004] This utility model also proposes a battery cell having the above-mentioned battery casing.

[0005] This utility model also proposes a battery device having the above-mentioned battery cells.

[0006] A battery casing according to a first aspect of the present invention includes: a housing, the outer surface roughness of the housing being greater than or equal to Ra0.4; and a protective coating disposed on the outer surface of the housing and including a transition layer and an insulating layer, the transition layer covering the outer surface of the housing, and the insulating layer disposed on the side of the transition layer opposite to the housing.

[0007] According to the battery casing of this utility model embodiment, the outer surface of the battery casing is provided with a protective coating with insulating properties, which can play an insulating and protective role. The adhesion between the protective coating and the casing surface is better than that of the blue film, so that the protective coating is less likely to fall off than the blue film. Furthermore, by setting the roughness of the outer surface of the casing to not less than Ra0.4, and by setting the protective coating as a multi-layer coating structure including a transition layer and an insulating layer, the adhesion between the protective coating and the casing surface can be enhanced, making the protective coating less likely to fall off and ensuring the insulating and protective effect of the protective coating.

[0008] According to some embodiments of the present invention, the outer surface roughness of the housing is Ra0.4 to Ra12.5; and / or, the transition layer includes a polyurethane layer or an epoxy resin layer, and the insulating layer includes an epoxy resin layer or a polyacrylate layer.

[0009] According to some embodiments of the present invention, the outer surface of the housing is formed with an uneven structure.

[0010] According to some embodiments of the present invention, the concave-convex structure includes groove patterns, and the groove patterns are strip-shaped and multiple.

[0011] According to some embodiments of this utility model, multiple groove patterns are spaced apart or intersected.

[0012] According to some embodiments of the present invention, the thickness of the insulating layer is greater than the thickness of the transition layer; and / or, the thickness of the protective coating ranges from 50 μm to 500 μm.

[0013] According to some embodiments of the present invention, the thickness of the insulating layer ranges from 25 μm to 250 μm; and / or, the thickness of the transition layer ranges from 25 μm to 250 μm.

[0014] According to some embodiments of the present invention, the housing is cylindrical, and the outer surface of the housing includes an outer peripheral surface and an end surface. The end surfaces are located on both axial sides of the housing, and the outer peripheral surface is located between the two end surfaces. The protective coating includes a first protective coating and a second protective coating. The first protective coating is disposed on the outer peripheral surface, and the second protective coating is disposed on the end surface and connected to the first protective coating. The connection position between the first protective coating and the second protective coating is located at the connection between the outer peripheral surface and the end surface.

[0015] According to some embodiments of the present invention, the second protective coating is annular, and the end face is provided with a mounting hole for mounting electrode terminals, and the second protective coating is disposed around the mounting hole.

[0016] A battery cell according to a second aspect of the present invention includes: a battery casing according to the first aspect of the present invention, the battery casing having electrode terminals; and an electrode assembly disposed within the battery casing and connected to the electrode terminals.

[0017] According to the battery cell of this utility model embodiment, by providing the above-mentioned battery casing, the outer surface of the battery casing is provided with a protective coating with insulating properties, which can play an insulating and protective role. The adhesion between the protective coating and the casing surface is better than that of the blue film, so that the protective coating is less likely to fall off than the blue film. Furthermore, by setting the roughness of the outer surface of the casing to not less than Ra0.4, and by setting the protective coating as a multi-layer coating structure including a transition layer and an insulating layer, the adhesion between the protective coating and the casing surface can be enhanced, making the protective coating less likely to fall off, ensuring the insulating and protective effect of the protective coating, and improving the safety performance of the battery cell.

[0018] A battery device according to a third aspect of the present invention includes: a housing; and a battery cell according to the second aspect of the present invention disposed within the housing.

[0019] According to the battery device of this utility model embodiment, by setting the above-mentioned battery cell, the battery cell can play an insulating and protective role by setting an insulating protective coating on the outer surface of the casing. The adhesion between the protective coating and the casing surface is better than that of the blue film, so that the protective coating is less likely to fall off than the blue film. Furthermore, by setting the roughness of the outer surface of the casing to not less than Ra0.4, and by setting the protective coating to a multi-layer coating structure including a transition layer and an insulating layer, the adhesion between the protective coating and the casing surface can be enhanced, making the protective coating less likely to fall off, ensuring the insulating and protective effect of the protective coating, and improving the safety performance of the battery cell.

[0020] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of a battery cell according to some embodiments of the present invention; Figure 2 This is a schematic diagram of a battery casing according to some embodiments of the present invention; Figure 3 This is a partial cross-sectional schematic diagram of the battery casing according to some embodiments of the present invention; Figure 4 This is a schematic diagram of the groove pattern on the outer surface of the battery casing according to some embodiments of the present invention; Figure 5 This is a schematic diagram of the groove pattern on the outer surface of the battery casing according to other embodiments of the present invention; Figure 6 This is a schematic diagram of the groove pattern on the outer surface of a battery casing according to some embodiments of the present invention; Figure 7 This is a schematic diagram of a battery device according to some embodiments of the present invention.

[0022] Figure label: 100. Battery cell; 10. Battery casing; 11. Housing; 111. Outer peripheral surface; 112. End face; 113. Mounting hole; 114. Groove pattern; 12. Protective coating; 121. Transition layer; 122. Insulating layer; 123. First protective coating; 124. Second protective coating; 21. Electrode terminals; 200. Battery assembly; 30. Housing. Detailed Implementation

[0023] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0024] The following is for reference. Figures 1-6 The battery casing 10 according to an embodiment of the present utility model is described.

[0025] Reference Figures 1-3 According to a first aspect of the present invention, a battery casing 10 includes a casing 11 and a protective coating 12, the protective coating 12 being disposed on the outer surface of the casing 11. The casing 11 can be a metal casing, such as a steel casing, an aluminum casing, or an aluminum alloy casing. The protective coating 12 is disposed on the outer surface of the casing 11, and the protective coating 12 can be applied to the outer surface of the casing 11 by spraying or coating. The protective coating 12 has good insulation properties; for example, at least a portion of the protective coating 12 can be a resin coating. By covering the outer surface of the casing 11 with an insulating protective coating 12, the battery can be insulated and protected, preventing external conductive materials from contacting the casing 11 and causing a short circuit. By replacing the blue film with the protective coating 12, the protective coating 12 is less likely to peel off from the casing 11 and has better scratch resistance. Its insulating properties are less prone to failure, providing stable and reliable insulation protection.

[0026] The outer surface roughness of the housing 11 is greater than or equal to Ra0.4, which gives the outer surface of the housing 11 a micro-uneven structure. When the protective coating 12 is sprayed onto the outer surface of the housing 11, these micro-uneven structures on the outer surface of the housing 11 interlock with the protective coating 12, which can improve the mechanical bonding force between the protective coating 12 and the housing 11. Furthermore, the micro-uneven structure on the outer surface of the housing 11 can also increase the base area between the protective coating 12 and the outer surface of the housing 11. The moderately rough surface can enhance the wettability of the coating, making the liquid coating easier to spread and fill the micropores to form a continuous interface layer. This can enhance the adhesion between the protective coating 12 and the housing 11, making the protective coating 12 less likely to fall off the housing 11.

[0027] It should be noted that the unit of Ra0.4 is μm.

[0028] For example, the outer surface of the housing 11 can be roughened by sandblasting, grinding, or laser cleaning, so that the roughness of the outer surface of the housing 11 reaches Ra0.4 or above.

[0029] Furthermore, the protective coating 12 may include a transition layer 121 and an insulating layer 122. The transition layer 121 covers the outer surface of the housing 11, and the insulating layer 122 is disposed on the side of the transition layer 121 facing away from the housing 11. During the process of spraying the protective coating 12 onto the outer surface of the housing 11, the transition layer 121 may be sprayed onto the outer surface of the housing 11 first, and then the insulating layer 122 may be sprayed onto the transition layer 121. The transition layer 121 may be a single layer or multiple layers, and the insulating layer 122 may be a single layer or multiple layers.

[0030] The insulating layer 122 has insulating properties. For example, the insulating properties of the insulating layer 122 can be better than those of the transition layer 121, and the adhesion between the transition layer 121 and the shell 11 can be better than the adhesion between the insulating layer 122 and the shell 11.

[0031] By setting the protective coating 12 covering the outer surface of the housing 11 to include a stacked transition layer 121 and an insulating layer 122, it is beneficial to further enhance the adhesion between the protective coating 12 and the housing 11. Furthermore, the material composition of the transition layer 121 and the insulating layer 122 can be set as needed to better meet the adhesion requirements between the protective coating 12 and the housing 11, as well as the protective and insulating performance of the protective coating 12.

[0032] According to the battery casing 10 of this utility model embodiment, the outer surface of the casing 11 of the battery casing 10 is provided with a protective coating 12 with insulating properties, which can play an insulating and protective role. The adhesion between the protective coating 12 and the surface of the casing 11 is better than that of the blue film, so that the protective coating 12 is not easy to fall off from the blue film. Furthermore, by setting the roughness of the outer surface of the casing 11 to not less than Ra0.4, and by setting the protective coating 12 as a multi-layer coating structure including a transition layer 121 and an insulating layer 122, the adhesion between the protective coating 12 and the surface of the casing 11 can be enhanced, making the protective coating 12 less likely to fall off and ensuring the insulating and protective effect of the protective coating 12.

[0033] According to some embodiments of this utility model, the surface roughness of the outer surface of the housing 11 is Ra0.4 to Ra12.5. For example, the surface roughness of the outer surface of the housing 11 is Ra0.4, Ra0.8, Ra1.2, Ra1.8, Ra2.4, Ra3.4, Ra4.4, Ra5.4, Ra6.4, Ra7.4, Ra8.4, Ra9.4, Ra10.4, Ra11.4, Ra12.5, etc. By setting the surface roughness of the outer surface of the housing 11 between Ra0.4 and Ra12.5, the outer surface of the housing 11 has a suitable roughness, which improves the adhesion between the protective coating 12 and the outer surface of the housing 11. At the same time, it can avoid uneven coating thickness and insufficient coating thickness at the peaks due to excessive surface roughness of the housing 11, which would affect the insulation and protective performance. This can increase the adhesion between the protective coating 12 and the housing 11, and make the protective coating 12 more uniform, so as to better cover the outer surface of the housing 11 and ensure the protective insulation performance of the protective coating 12.

[0034] According to some embodiments of the present invention, the transition layer 121 includes a polyurethane layer or an epoxy resin layer, and the insulating layer 122 includes an epoxy resin layer or a polyacrylate layer. For example, the transition layer 121 can be a polyurethane layer, and the insulating layer 122 can be a polyacrylate layer; for example, the transition layer 121 can be an epoxy resin layer, and the insulating layer 122 can be a polyacrylate layer; for example, the transition layer 121 can be a polyurethane layer, and the insulating layer 122 can be an epoxy resin layer.

[0035] By configuring the transition layer 121 to include a polyurethane layer or an epoxy resin layer, the strong adhesion between the polyurethane layer or epoxy resin layer and the metal substrate enhances the adhesion between the transition layer 121 and the housing 11, thereby strengthening the adhesion between the protective coating 12 and the housing 11 and reducing the possibility of the protective coating 12 detaching. Similarly, by including an epoxy resin layer or a polyacrylate layer in the insulating layer 122, the insulating layer 122 exhibits good insulation properties, thus providing the protective coating 12 with good insulation performance. Therefore, by including the aforementioned transition layer 121 and insulating layer 122 in the protective coating 12, the adhesion between the protective coating 12 and the housing 11 is strong, resulting in good insulation and protective performance.

[0036] According to some embodiments of this utility model, refer to Figures 2-6 The outer surface of the housing 11 has an uneven structure. By providing an uneven structure on the outer surface of the housing 11, the outer surface of the housing 11 can have a suitable roughness. The uneven structure can enhance the adhesion between the protective coating 12 and the housing 11 and reduce the possibility of the protective coating 12 falling off.

[0037] According to some embodiments of this utility model, refer to Figures 2-6The concave-convex structure includes grooves 114, which are strip-shaped and multiple in number. For example, the grooves 114 can be formed on the outer surface of the housing 11 by laser cleaning. By providing grooves 114 on the outer surface of the housing 11, when the protective coating 12 is sprayed onto the outer surface of the housing 11, a portion of the protective coating 12 can be embedded into the grooves 114 on the outer surface of the housing 11, thereby enhancing the adhesion between the protective coating 12 and the housing 11 and reducing the possibility of the protective coating 12 falling off.

[0038] In some embodiments of this utility model, reference is made to Figures 4-6 Multiple grooves 114 are spaced apart or intersecting. By arranging multiple grooves 114 spaced apart or intersecting, the grooves 114 on the outer surface of the housing 11 can be more evenly distributed, resulting in a stronger bond between each part of the protective coating 12 and the housing 11, thereby better reducing the possibility of the protective coating 12 falling off.

[0039] For example, in Figure 4 In the example, multiple groove patterns 114 are spaced apart, and the multiple groove patterns 114 can be arranged in parallel.

[0040] For example, in Figure 5 In the example, multiple groove patterns 114 are intersecting and intersecting to form a grid.

[0041] For example, in Figure 6 In the example, multiple groove patterns 114 are arranged intersectingly. The multiple groove patterns 114 include long groove patterns 114 and short groove patterns. The long groove patterns 114 are multiple patterns arranged at intervals. The short groove patterns 114 are distributed between two adjacent long groove patterns 114 and are arranged at intervals along the extension direction of the long groove patterns 114, and intersect with the two adjacent long groove patterns 114.

[0042] According to some embodiments of this utility model, refer to Figure 3 The thickness d1 of the insulating layer 122 is greater than the thickness d2 of the transition layer 121. By making the thickness d1 of the insulating layer 122 greater than the thickness d2 of the transition layer 121, the insulating and protective performance of the protective coating 12 can be guaranteed.

[0043] According to some embodiments of this utility model, refer to Figure 3The thickness of the protective coating 12 is d0, and the value of the thickness d0 of the protective coating 12 ranges from 50μm to 500μm. For example, the thickness d0 of the protective coating 12 can be 50μm, 100μm, 150μm, 200μm, 250μm, 300μm, 350μm, 400μm, 450μm, 500μm, etc. By setting the thickness d0 of the protective coating 12 to 50μm to 500μm, the thickness of the protective coating 12 can better cover the outer surface of the shell 11 to ensure the insulation and protection performance. It can also avoid cracking due to stress concentration caused by excessive thickness of the protective coating 12, and can also reduce the amount of material used for the protective coating 12.

[0044] According to some embodiments of this utility model, refer to Figure 3 The thickness of the insulating layer 122 ranges from 25 μm to 250 μm. The thickness d1 of the insulating layer 122 ranges from 50 μm to 500 μm. For example, the thickness d1 of the insulating layer 122 can be 25 μm, 50 μm, 75 μm, 100 μm, 125 μm, 150 μm, 175 μm, 200 μm, 225 μm, 250 μm, etc. By setting the thickness d1 of the insulating layer 122 to 25 μm to 250 μm, the thickness of the insulating layer 122 can better cover the outer surface of the shell 11, thereby ensuring the insulation and protection performance. It can also avoid stress concentration and cracking caused by excessive thickness of the insulating layer 122, and can also reduce the amount of material used for the insulating layer 122.

[0045] According to some embodiments of this utility model, refer to Figure 3 The thickness of the transition layer 121 ranges from 25 μm to 250 μm. The thickness d2 of the transition layer 121 ranges from 50 μm to 500 μm. For example, the thickness d2 of the transition layer 121 can be 25 μm, 50 μm, 75 μm, 100 μm, 125 μm, 150 μm, 175 μm, 200 μm, 225 μm, 250 μm, etc. By setting the thickness d2 of the transition layer 121 to 25 μm to 250 μm, the thickness of the transition layer 121 can better cover the outer surface of the shell 11 to ensure insulation and protection performance. It can also avoid stress concentration and cracking caused by excessive thickness of the transition layer 121, and can also reduce the amount of material used in the transition layer 121.

[0046] According to some embodiments of this utility model, refer to Figures 1-2The shell 11 is cylindrical, and its outer surface includes an outer peripheral surface 111 and an end surface 112. The end surfaces 112 are located on both axial sides of the shell 11, and the outer peripheral surface 111 is located between the two end surfaces 112. The end surfaces 112 are circular, and the cross-section of the outer peripheral surface 111 is annular. The protective coating 12 includes a first protective coating 123 and a second protective coating 124. The first protective coating 123 is disposed on the outer peripheral surface 111, and the second protective coating 124 is disposed on the end surface 112 and connected to the first protective coating 123. The connection point between the first protective coating 123 and the second protective coating 124 is located at the connection between the outer peripheral surface 111 and the end surface 112. By providing a protective coating 12 on the outer surface of the housing 11, compared to providing a blue film, it can better cover all parts of the outer surface of the housing 11. In particular, the connection between the outer peripheral surface 111 and the end face 112 of the housing 11 forms an annular edge, which can be better covered by the protective coating 12, thereby providing better insulation and protection.

[0047] According to some embodiments of this utility model, refer to Figures 1-2 The second protective coating 124 is annular, for example, circular. The end face 112 is provided with mounting holes 113 for mounting electrode terminals 21, and the second protective coating 124 surrounds the mounting holes 113. By making the second protective coating 124 on the end face 112 annular, it can cover the part of the end face 112 that needs to be covered as much as possible, and at the same time, it can avoid the second protective coating 124 from affecting the installation of electrode terminals 21.

[0048] According to a second aspect of the present invention, a battery cell 100 includes a battery casing 10 and an electrode assembly according to the first aspect of the present invention. The battery casing 10 is provided with an electrode terminal 21, and the electrode assembly is disposed inside the battery casing 10 and connected to the electrode terminal 21.

[0049] The electrode assembly may include a positive electrode, a negative electrode, and an insulating separator, with the insulating separator disposed between the positive and negative electrode. The electrode assembly includes a positive electrode tab and a negative electrode tab. The battery casing 10 may have two electrode terminals 21, one of which is a positive electrode and the other is a negative electrode. The positive and negative electrode tabs are respectively connected to the electrode terminals 21 of the same polarity.

[0050] According to the embodiment of the present invention, the battery cell 100, by providing the aforementioned battery casing 10, has an insulating protective coating 12 on the outer surface of the casing 11, which provides insulation protection. The protective coating 12 has better adhesion to the surface of the casing 11 than the blue film, making it less likely for the protective coating 12 to fall off. Furthermore, by setting the roughness of the outer surface of the casing 11 to be not less than Ra0.4, and by setting the protective coating 12 to a multi-layer coating structure including a transition layer 121 and an insulating layer 122, the adhesion between the protective coating 12 and the surface of the casing 11 can be enhanced, making the protective coating 12 less likely to fall off, ensuring the insulating protective effect of the protective coating 12, and improving the safety performance of the battery cell 100.

[0051] The battery device 200 according to the third aspect of the present invention includes: a battery cell 100 according to the second aspect of the present invention, wherein the battery cell 100 is disposed in the housing 30, and there may be multiple battery cells 100.

[0052] For example, battery device 200 can be used in energy storage devices.

[0053] According to the battery device 200 of this utility model embodiment, by providing the aforementioned battery cell 100, the battery cell 100 can play an insulating and protective role by providing an insulating protective coating 12 on the outer surface of the housing 11. The adhesion between the protective coating 12 and the surface of the housing 11 is better than that of the blue film, so that the protective coating 12 is less likely to fall off relative to the blue film. Furthermore, by setting the roughness of the outer surface of the housing 11 to not less than Ra0.4, and by setting the protective coating 12 to a multi-layer coating structure including a transition layer 121 and an insulating layer 122, the adhesion between the protective coating 12 and the surface of the housing 11 can be enhanced, making the protective coating 12 less likely to fall off, ensuring the insulating and protective effect of the protective coating 12, and improving the safety performance of the battery cell 100.

[0054] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to 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 utility model.

[0055] In the description of this utility model, "first feature" and "second feature" may include one or more of the features.

[0056] In the description of this utility model, "multiple" means two or more.

[0057] In the description of this utility model, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or it may include the first and second features not being in direct contact but being in contact through another feature between them.

[0058] In the description of this utility model, the terms "above", "over" and "on top" for the first feature and the second feature include the first feature being directly above or diagonally above the second feature, or simply indicate that the first feature is at a higher horizontal level than the second feature.

[0059] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0060] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery casing, characterized in that, include: A housing, wherein the roughness of the outer surface of the housing is greater than or equal to Ra0.4; A protective coating is provided on the outer surface of the housing and includes a transition layer and an insulating layer. The transition layer covers the outer surface of the housing, and the insulating layer is provided on the side of the transition layer opposite to the housing.

2. The battery casing according to claim 1, characterized in that, The outer surface roughness of the housing is Ra0.4 to Ra12.5; and / or, the transition layer comprises a polyurethane layer or an epoxy resin layer, and the insulating layer comprises an epoxy resin layer or a polyacrylate layer.

3. The battery casing according to claim 1, characterized in that, The outer surface of the shell has a concave-convex structure, which includes grooves, and the grooves are strip-shaped and multiple.

4. The battery casing according to claim 3, characterized in that, The grooves are spaced apart or intersected.

5. The battery casing according to claim 1, characterized in that, The thickness of the insulating layer is greater than the thickness of the transition layer; and / or, the thickness of the protective coating ranges from 50 μm to 500 μm.

6. The battery casing according to claim 1, characterized in that, The thickness of the insulating layer ranges from 25 μm to 250 μm; and / or, the thickness of the transition layer ranges from 25 μm to 250 μm.

7. The battery casing according to any one of claims 1-6, characterized in that, The housing is cylindrical, and the outer surface of the housing includes an outer peripheral surface and an end surface. The end surfaces are located on both axial sides of the housing, and the outer peripheral surface is located between the two end surfaces. The protective coating includes a first protective coating and a second protective coating. The first protective coating is disposed on the outer peripheral surface, and the second protective coating is disposed on the end surface and connected to the first protective coating. The connection position between the first protective coating and the second protective coating is located at the connection between the outer peripheral surface and the end surface.

8. The battery casing according to claim 7, characterized in that, The second protective coating is annular, and the end face is provided with mounting holes for mounting electrode terminals. The second protective coating is disposed around the mounting holes.

9. A single battery cell, characterized in that, include: The battery casing according to any one of claims 1-8, wherein the battery casing is provided with electrode terminals; An electrode assembly is disposed inside the battery casing and connected to the electrode terminals.

10. A battery device, characterized in that, include: Box; The battery cell according to claim 9 is disposed inside the housing.

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