Battery cover plate assembly, battery monomer, battery assembly and electric equipment

Abstract

The utility model discloses a battery cover plate assembly, a battery monomer, a battery assembly and electric equipment, the battery cover plate assembly comprises a cover plate and a sealing cover, and a mounting groove is formed in the outer side surface of the cover plate; the sealing cover is mounted in the mounting groove, the sealing cover comprises a main body part and a welding bulge, the welding bulge forms an annular bulge protruding along the edge of the main body part, and the welding bulge protrudes towards the direction deviating from the inner side surface of the cover plate; and a welding seam is arranged between the outer peripheral wall of the welding bulge and the inner peripheral wall of the mounting groove. Therefore, edge covering welding can be achieved by welding the welding protrusion and the cover plate, in the welding process, the welding protrusion can deform in the direction away from the inner circumferential wall of the installation groove, stress generated in the welding process can be relieved, the installation stability of the sealing cover is improved, and therefore the sealing effect of the sealing cover is improved.

Description

Technical Field

[0001] This utility model relates to the field of batteries, and in particular to a battery cover assembly, a battery cell, a battery assembly, and an electrical device. Background Technology

[0002] In related technologies, after the battery is filled with electrolyte, the filling hole needs to be sealed with a sealing strip to prevent leakage. The sealing strip is welded into a groove surrounding the battery filling hole. However, the process window for seam welding is small, resulting in poor welding effect and inadequate sealing performance, leaving room for improvement. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a battery cover assembly that can improve the installation stability of the sealing cover, thereby improving the sealing effect of the sealing cover.

[0004] A battery cover assembly according to an embodiment of the present invention includes: a cover plate, wherein an mounting groove is formed on the outer side of the cover plate; and a sealing cover, wherein the sealing cover is installed in the mounting groove, the sealing cover including a main body and a welding protrusion, the welding protrusion being formed as an annular protrusion protruding along the edge of the main body, the welding protrusion protruding in a direction away from the inner side of the cover plate, and a weld being provided between the outer peripheral wall of the welding protrusion and the inner peripheral wall of the mounting groove.

[0005] According to the battery cover assembly of this utility model embodiment, by providing welding protrusions on the main body, the welding protrusions can be welded to the cover to achieve edge welding. During the welding process, the welding protrusions can deform in the direction away from the inner peripheral wall of the mounting groove, which helps to relieve the stress generated during the welding process, improves the installation stability of the sealing cover, and thus improves the sealing effect of the sealing cover.

[0006] According to some embodiments of the present invention, the protruding direction of the welding protrusion is a first direction, the width of the welding protrusion along the second direction is W1, the first direction intersects the second direction, and the battery cover assembly satisfies: 2mm ≥ W1 ≥ 0.3mm.

[0007] According to some embodiments of the present invention, the battery cover assembly includes a main body portion including a support portion, a welding protrusion disposed on the support portion, and the support portion supporting the inner wall of the mounting groove.

[0008] According to some embodiments of the present invention, in the battery cover assembly, the protruding direction of the welding protrusion is a first direction, and in a second direction, the width of the support portion is greater than the width of the welding protrusion, and the first direction intersects with the second direction.

[0009] According to some embodiments of the present invention, in the battery cover assembly, the width of the support portion along the second direction is W2, which satisfies: 5mm ≥ W2 ≥ 1mm.

[0010] According to some embodiments of the present invention, in the battery cover assembly, at least a portion of the inner peripheral wall of the mounting groove is formed as a downward-facing, inclined surface extending toward the direction of the sealing cover.

[0011] According to some embodiments of the present invention, in the battery cover assembly, the included angle between the inclined surface and the bottom wall of the mounting groove is α1, which satisfies: 120°≥α1>90°.

[0012] According to some embodiments of the present invention, the bottom wall of the mounting groove is provided with a recessed groove facing the inner side, and the groove is provided with the liquid injection hole.

[0013] The battery cover assembly according to some embodiments of the present invention further includes a sealing plug for sealing the injection hole, wherein the portion of the sealing plug protruding from the bottom wall of the groove is spaced apart from the inner peripheral wall of the groove.

[0014] According to some embodiments of the present invention, in the battery cover assembly, the sealing plug and the sealing cover are spaced apart from each other on their sidewalls.

[0015] According to some embodiments of the present invention, in the battery cover assembly, at least a portion of the main body protrudes in a direction away from the sealing plug.

[0016] According to some embodiments of the present invention, a buffer groove is defined between the main body and the welding protrusion, the buffer groove being located on the surface of the sealing cover opposite to the injection hole.

[0017] According to some embodiments of the present invention, the maximum distance between the main body and the top wall of the sealing plug in the battery cover assembly is H1, which satisfies: 5mm ≥ H1 ≥ 0.1mm.

[0018] This utility model also proposes a battery cell.

[0019] The battery cell according to the present invention includes the battery cover assembly according to any of the above embodiments.

[0020] This utility model also proposes a battery assembly.

[0021] The battery assembly according to the present invention includes the battery cell according to any of the above embodiments.

[0022] This utility model also proposes an electrical device.

[0023] The electrical equipment according to the embodiments of the present invention includes the battery assembly described in any of the above embodiments.

[0024] The battery cell, battery module, electrical device, and battery cover assembly have the same advantages over the prior art, and will not be repeated here.

[0025] 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

[0026] 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:

[0027] Figure 1 This is a schematic diagram of a battery cover assembly according to an embodiment of the present utility model;

[0028] Figure 2 yes Figure 1 A magnified view of a section at point A in the middle;

[0029] Figure 3 This is a schematic diagram of the installation of the sealing cap according to an embodiment of the present utility model;

[0030] Figure 4 This is a schematic diagram of the installation of the sealing cap according to another embodiment of the present invention.

[0031] Figure label:

[0032] Battery cover assembly 100, first direction F1, second direction F2,

[0033] Cover plate 1, outer side 1a of cover plate, inner side 1b of cover plate, injection hole 11, mounting groove 12, inclined surface 121, groove 13.

[0034] Sealing cover 2, main body 21, support part 211, welding protrusion 22, buffer groove 23

[0035] Sealing plug 3, head 31, plug body 32. Detailed Implementation

[0036] 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.

[0037] 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," and "circumferential," etc., indicating the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model 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 utility model. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0038] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0039] Hereinafter, with reference to the accompanying drawings, a battery cover assembly 100 according to an embodiment of the present invention will be described.

[0040] like Figures 1-4 As shown, the battery cover assembly 100 according to an embodiment of the present invention includes: a cover plate 1 and a sealing cover 2. An mounting groove 12 is formed on the outer side 1a of the cover plate 1. The sealing cover 2 is installed in the mounting groove 12. The sealing cover 2 includes a main body 21 and a welding protrusion 22. The welding protrusion 22 is formed as an annular protrusion protruding along the edge of the main body 21. The welding protrusion 22 protrudes in a direction away from the inner side 1b of the cover plate 1. A weld is provided between the outer peripheral wall of the welding protrusion 22 and the inner peripheral wall of the mounting groove 12. This improves the installation stability of the sealing cover 2, thereby enhancing the sealing effect of the sealing cover 2 on the injection hole 11.

[0041] First, such as Figures 1-3As shown, the battery cell includes a casing and a battery cover assembly 100. An open receiving cavity is formed within the casing to contain electrolyte. The battery cover assembly 100 includes a cover plate 1 and a sealing cap 2. The cover plate 1 is used to cover the open end of the receiving cavity to close it. The cover plate 1 has a through-hole 11 extending along its thickness direction, communicating with the receiving cavity. Electrolyte is suitable for injection into the receiving cavity through the through-hole 11. An mounting groove 12 is provided on the outer surface 1a of the cover plate 1, surrounding the through-hole 11. It should be noted that the side of the cover plate 1 facing away from the receiving cavity is designated as the outer surface 1a, and the side of the cover plate 1 facing the receiving cavity is designated as the inner surface 1b.

[0042] The sealing cap 2 is matched with the mounting groove 12 and installed inside the mounting groove 12. The sealing cap 2 includes a main body 21 and a welding protrusion 22. The main body 21 is supported on the bottom wall of the mounting groove 12 and its outer peripheral wall mates with the inner peripheral wall of the mounting groove 12. The welding protrusion 22 is formed as an annular protrusion protruding along the edge of the main body 21 and protruding in a direction away from the inner side 1b of the cover plate 1. Welds are provided between the outer peripheral wall of the welding protrusion 22 and the inner peripheral wall of the mounting groove 12, and between the main body 21 and the outer peripheral wall of the main body 21 and the inner peripheral wall of the mounting groove 12. By welding at the welds, the sealing cap 2 can be welded and fixed to the cover plate 1, thereby sealing the injection hole 11.

[0043] Therefore, the sealing cover 2 and the cover plate 1 can be welded together, and the welding protrusion 22 can deform away from the inner peripheral wall of the mounting groove 12 during the welding process to relieve the stress generated during the welding process and improve the installation stability of the sealing cover 2.

[0044] According to the battery cover assembly 100 of this utility model embodiment, by providing a welding protrusion 22 on the main body 21, the welding protrusion 22 can be welded to the cover plate 1 to achieve edge welding. During the welding process, the welding protrusion 22 can deform in the direction away from the inner peripheral wall of the mounting groove 12, which helps to relieve the stress generated during the welding process, improves the installation stability of the sealing cover 2, and thus improves the sealing effect of the sealing cover 2.

[0045] In some embodiments of this utility model, such as Figure 2 As shown, the protruding direction of the welding protrusion 22 is the first direction F1. The width of the welding protrusion 22 along the second direction F2 can be set as W1. The first direction F1 and the second direction F2 intersect, and the battery cover assembly 100 satisfies: 2mm ≥ W1 ≥ 0.3mm. It should be noted that the first direction F1 can be set as... Figure 1 The vertical direction is shown, and the second direction F2 is set as... Figure 1The left and right directions are shown. That is to say, the width W1 of the welding protrusion 22 along the second direction F2 can be set to be greater than or equal to 0.3mm and less than or equal to 2mm, such as 0.3mm, 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, etc.

[0046] With the above settings, the welding protrusion 22 can be easily deformed during the welding process, and the welding protrusion 22 can be fully welded during the welding process, so that some of the molten liquid can flow away from the inner peripheral wall of the mounting groove 12 (or has a tendency to flow away from the inner peripheral wall of the mounting groove 12), so as to release the stress during the welding process, thereby improving the installation stability of the sealing cover 2.

[0047] In some embodiments of this utility model, such as Figure 2 As shown, the main body 21 can be provided with a support part 211, and a welding protrusion 22 is provided on the support part 211. The support part 211 is used to support the inner wall of the mounting groove 12 to limit and support the sealing cover 2. With the above arrangement, the stability of the welding protrusion 22 can be ensured, so as to avoid relative movement between the welding protrusion 22 and the inner peripheral wall of the mounting groove 12, which is beneficial to improving the welding quality.

[0048] In some embodiments of this utility model, such as Figure 2 As shown, the protruding direction of the welding protrusion 22 is the first direction F1. In the second direction F2, the width of the support portion 211 can be set to be greater than the width of the welding protrusion 22, and the first direction F1 and the second direction F2 are intersected. It should be noted that the first direction F1 can be set as... Figure 2 The vertical direction is shown, and the second direction F2 is set as... Figure 2 The left and right directions are shown. This improves the support effect of the support part 211 and helps improve welding quality.

[0049] In some embodiments of this utility model, such as Figure 2 As shown, the width of the support portion 211 along the second direction F2 can be set to W2, satisfying: 5mm ≥ W2 ≥ 1mm. That is, the width W2 of the support portion 211 along the second direction F2 can be set to be greater than or equal to 1mm and less than or equal to 5mm, such as 1mm, 2mm, 3mm, 4mm, 5mm, etc. For example, the width W1 of the welding protrusion 22 along the second direction F2 can be set to 0.5mm, and the width W2 of the support portion 211 along the second direction F2 can be set to 2mm.

[0050] The above settings ensure the support effect of the support part 211 on the sealing cover 2, improve the installation stability of the sealing cover 2, and reduce the contact area between the sealing cover 2 and the bottom wall of the mounting groove 12, which helps to reduce the processing accuracy requirements of the sealing cover 2.

[0051] In addition, when the middle part of the main body 21 protrudes in a direction away from the sealing plug 3, the welding protrusion 22 can be kept at a certain distance from the rest of the main body 21, which helps to reduce the molding difficulty of the sealing cap 2.

[0052] Of course, this utility model is not limited to this, such as Figure 4 As shown, the sidewall of the main body 21 facing the inner side 1b of the cover plate 1 can also be constructed as a plane to increase the mating area between the main body 21 and the cover plate 1. This can improve the stability of the main body 21.

[0053] In some embodiments of this utility model, such as Figure 2 As shown, at least a portion of the inner peripheral wall of the mounting groove 12 can be formed as a downward-facing inclined surface 121 extending towards the sealing cover 2. The outer peripheral walls of the welding protrusion 22 and the outer peripheral walls of the main body 21 are correspondingly inclined so that the welding protrusion 22 and the main body 21 can fit onto the inclined surface 121.

[0054] The above settings can increase the welding area between the sealing cover 2 and the mounting groove 12, and make the flow of molten liquid along the weld seam more stable, which is conducive to improving the welding quality and thus improving the installation stability of the sealing cover 2.

[0055] In some embodiments of this utility model, such as Figure 2 As shown, the included angle between the inclined surface 121 and the bottom wall of the mounting groove 12 can be set as α1, satisfying: 120° ≥ α1 > 90°. That is, the included angle between the inclined surface 121 and the bottom wall of the mounting groove 12 can be set to be less than or equal to 120° and greater than or equal to 90°, such as 90°, 95°, 100°, 105°, 110°, 115°, 120°, etc. This reduces the molding difficulty of the mounting groove 12 and ensures the guiding effect of the inclined surface 121 on the molten liquid.

[0056] In some embodiments of this utility model, such as Figure 1 As shown, a recessed groove 13 facing the inner side 1b can be provided on the bottom wall of the mounting groove 12. The bottom wall of the groove 13 is provided with a liquid injection hole 11. The sealing cap 2 and the cover plate 1 can define a gas-containing space at the groove 13. The gas-containing space is used to contain the gas generated by the electrolyte around the liquid injection hole 11 under the welding heat.

[0057] The above settings can prevent gas impact on the weld, help eliminate problems such as microcracks, micropores, and weld holes, and improve welding quality.

[0058] In some embodiments of the present invention, the battery cover assembly 100 of the present invention further includes a sealing plug 3, which is used to block the liquid injection hole 11. The portion of the sealing plug 3 protruding from the bottom wall of the groove 13 is spaced apart from the inner peripheral wall of the groove 13.

[0059] For example, refer to Figure 1 As shown, the battery cover assembly 100 also includes a sealing plug 3, which can be made of an elastic material such as rubber. The sealing plug 3 includes a connected head 31 and a plug body 32. The diameter of the head 31 is larger than the diameter of the plug body 32. The plug body 32 can be fitted to the injection hole 11 and has an interference fit with the injection hole 11, thereby sealing the injection hole 11.

[0060] The head 31 of the sealing plug 3 is located within the groove 13 and supported by the bottom wall of the groove 13. The diameter of the head 31 is smaller than the diameter of the groove 13, so that the outer peripheral wall of the head 31 can be spaced apart from the inner peripheral wall of the groove 13, thereby defining a gas-containing space between the sealing plug 3 and the inner peripheral wall of the groove 13. This ensures that the gas-containing space has sufficient space, improving the design rationality of the battery cover assembly 100.

[0061] In some embodiments of this utility model, such as Figure 1 As shown, the sealing plug 3 and the sealing cover 2 can be arranged with their side walls facing each other spaced apart, that is, the side wall of the sealing plug 3 facing away from the receiving cavity and the side wall of the sealing cover 2 facing the receiving cavity are arranged with their side walls spaced apart.

[0062] The above settings can prevent interference between the sealing plug 3 and the sealing cover 2, ensuring that the sealing cover 2 can be installed in place, improving the installation accuracy of the sealing cover 2, and defining a portion of the gas space between the sealing cover 2 and the sealing plug 3, which is beneficial to increasing the capacity of the gas space and improving the reliability of the battery cover assembly 100.

[0063] In some embodiments of this utility model, such as Figure 1 As shown, at least a portion of the main body 21 can be configured to protrude in a direction away from the sealing plug 3. For example, the middle portion of the main body 21 can be configured to protrude in a direction away from the sealing plug 3, thereby constructing the main body 21 as a bowl-shaped structure. With the above configuration, the overall structural strength of the sealing cover 2 can be improved, and the volume of the gas-containing space can be increased, preventing gas from impacting the weld and improving the sealing effect of the sealing cover 2.

[0064] In some embodiments of this utility model, such as Figure 1As shown, a buffer groove 23 can be defined between the main body 21 and the welding protrusion 22. The buffer groove 23 is located on the surface of the sealing cap 2 opposite to the injection hole 11. The buffer groove 23 can provide deformation space for the deformation of the welding protrusion 22 and can collect the molten liquid when it flows out of the weld. As a result, the welding quality of the sealing cap 2 and the cover plate 1 can be improved, and the sealing effect of the sealing cap 2 on the injection hole 11 can be improved.

[0065] In some embodiments of this utility model, such as Figure 2 As shown, the maximum distance between the main body 21 and the top wall of the sealing plug 3 can be set to H1, satisfying: 5mm ≥ H1 ≥ 0.1mm. That is, the maximum distance H1 between the main body 21 and the top wall of the sealing plug 3 can be set to be greater than or equal to 0.1mm and less than or equal to 5mm, such as 0.1mm, 0.5mm, 1mm, 2mm, 3mm, 4mm, 5mm, etc. Through the above settings, sufficient volume of the gas-bearing space can be ensured, and the structure of the sealing plug 3 can be made more reasonable, which is beneficial to ensuring the structural strength of the sealing plug 3 and improving the reliability of the battery cover assembly 100.

[0066] In some embodiments of this utility model, such as Figure 2 As shown, the depth of the mounting groove 12 can be set to H2, and the thickness of the main body 21 can be set to H3, satisfying: 1.4mm≥H2≥0.5mm, 1.3mm≥H3≥0.3mm, H2>H3.

[0067] In other words, the depth H2 of the mounting groove 12 can be set to be greater than or equal to 0.5 mm and less than or equal to 1.5 mm, such as 0.5 mm, 0.8 mm, 1 mm, 1.3 mm, 1.5 mm, etc.; the thickness H3 of the main body 21 can be set to be greater than or equal to 0.3 mm and less than or equal to 1.3 mm, such as 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, 1.3 mm, etc.; and the depth H2 of the mounting groove 12 can be set to be greater than the thickness H3 of the main body 21.

[0068] For example, the depth H2 of the mounting groove 12 can be 1 mm and the thickness H3 of the main body 21 can be 0.5 mm; or, the depth H2 of the mounting groove 12 can be 1.3 mm and the thickness H3 of the main body 21 can be 0.8 mm.

[0069] The above configuration allows the main body 21 to have sufficient thickness, which helps to ensure the structural stability of the sealing cover 2 and provides processing space for the welding protrusion 22, so that the welding protrusion 22 has sufficient protrusion height, allowing the welding protrusion 22 to deform during welding, thereby improving the reliability of the battery cover assembly 100.

[0070] This utility model also proposes a battery cell.

[0071] The battery cell according to the present invention includes the battery cover assembly 100 according to any of the above embodiments.

[0072] According to the embodiments of the present invention, the battery cover assembly 100 of the battery cell has a good sealing effect, which can improve the overall reliability of the battery cell.

[0073] This utility model also proposes a battery assembly.

[0074] The battery assembly according to the present invention includes a battery cell according to any of the above embodiments.

[0075] According to the battery assembly of the present invention, the overall reliability of the battery cells is high, which helps to ensure the operational stability of the battery assembly.

[0076] This utility model also proposes an electrical device.

[0077] The electrical equipment according to the embodiments of this utility model includes a battery module according to any of the above embodiments. It should be noted that the electrical equipment can be any of the following: new energy vehicles, hybrid vehicles, aircraft, etc.

[0078] According to the embodiments of this utility model, the electrical equipment has high overall reliability of the battery cells, which helps to ensure the operational stability of the battery assembly and improves the overall performance of the electrical equipment.

[0079] 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.

[0080] 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 cover assembly (100), characterized in that, include: A cover plate (1) has an mounting groove (12) formed on its outer side (1a); A sealing cover (2) is installed in the mounting groove (12). The sealing cover (2) includes a main body (21) and a welding protrusion (22). The welding protrusion (22) is formed as an annular protrusion protruding along the edge of the main body (21). The welding protrusion (22) protrudes in a direction away from the inner side (1b) of the cover plate (1). A weld is provided between the outer peripheral wall of the welding protrusion (22) and the inner peripheral wall of the mounting groove (12).

2. The battery cover assembly (100) according to claim 1, characterized in that, The protrusion direction of the welding protrusion (22) is the first direction (F1), the width of the welding protrusion (22) along the second direction (F2) is W1, the first direction (F1) intersects the second direction (F2), and the battery cover assembly (100) satisfies: 2mm ≥ W1 ≥ 0.3mm.

3. The battery cover assembly (100) according to claim 1, characterized in that, The main body (21) includes a support (211), the welding protrusion (22) is provided on the support (211), and the support (211) is supported on the inner wall of the mounting groove (12).

4. The battery cover assembly (100) according to claim 3, characterized in that, The protruding direction of the welding protrusion (22) is the first direction (F1), and the width of the support (211) is greater than the width of the welding protrusion (22) in the second direction (F2). The first direction (F1) and the second direction (F2) intersect.

5. The battery cover assembly (100) according to claim 4, characterized in that, The width of the support part (211) along the second direction (F2) is W2, which satisfies: 5mm ≥ W2 ≥ 1mm.

6. The battery cover assembly (100) according to claim 1, characterized in that, At least a portion of the inner peripheral wall of the mounting groove (12) is formed as a slope (121) extending downward and toward the direction of the sealing cover (2).

7. The battery cover assembly (100) according to claim 6, characterized in that, The included angle between the inclined surface (121) and the bottom wall of the mounting groove (12) is α1, which satisfies: 120°≥α1>90°.

8. The battery cover assembly (100) according to any one of claims 1-7, characterized in that, The bottom wall of the mounting groove (12) is provided with a recessed groove (13) facing the inner side (1b), and the groove (13) is provided with a liquid injection hole (11).

9. The battery cover assembly (100) according to claim 8, characterized in that, It also includes a sealing plug (3) for sealing the injection hole (11), and the portion of the sealing plug (3) protruding from the bottom wall of the groove (13) is spaced apart from the inner peripheral wall of the groove (13).

10. The battery cover assembly (100) according to claim 9, characterized in that, The sealing plug (3) and the sealing cap (2) are spaced apart from each other on their sidewalls.

11. The battery cover assembly (100) according to claim 10, characterized in that, At least a portion of the main body (21) protrudes in a direction away from the sealing plug (3).

12. The battery cover assembly (100) according to claim 11, characterized in that, A buffer groove (23) is defined between the main body (21) and the welding protrusion (22), the buffer groove (23) being located on the surface of the sealing cap (2) opposite to the injection hole (11).

13. The battery cover assembly (100) according to claim 11, characterized in that, The maximum distance between the main body (21) and the top wall of the sealing plug (3) is H1, which satisfies: 5mm ≥ H1 ≥ 0.1mm.

14. A single battery cell, characterized in that, Includes the battery cover assembly (100) according to any one of claims 1-13.

15. A battery assembly, characterized in that, Includes the battery cell according to claim 14.

16. An electrical appliance, characterized in that, Includes the battery assembly as described in claim 15.

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