Battery cell and electric equipment

Abstract

The invention relates to the technical field of battery manufacturing, in particular to a battery cell and electric equipment. The battery cell comprises a pole group, a cover plate and a shell, wherein the cover plate comprises a cover plate body and a first plastic part; the first plastic part is connected with one side, facing the pole group, of the cover plate body, and the outer edge of the first plastic part is arranged on the inner side of the outer edge of the cover plate body; a liquid injection hole penetrating through the cover plate body is formed in the cover plate body, the first plastic part comprises a liquid injection groove corresponding to the liquid injection hole, and a liquid injection flow guide hole penetrating through the first plastic part is formed in the first bottom wall of the liquid injection groove; the shell is connected with the outer edge of the cover plate body, an exhaust gap exists between the shell and the first plastic part, an exhaust hole penetrating through the shell is formed in the side wall, facing the shell, of the liquid injection groove, and the exhaust hole is communicated with the exhaust gap. According to the battery cell structure, the problem that in an existing battery cell structure, physical interference is easily formed between an adhesive tape on the surface of a pole group and an electrolyte flow guide hole formed below cover plate lower plastic, then an exhaust hole is blocked, battery cell exhausting is not complete, and battery cell bulging is caused is solved.

Description

Technical Field

[0001] This application relates to the field of battery manufacturing technology, and in particular to a battery cell and an electrical device. Background Technology

[0002] In the battery manufacturing process, the pre-charging stage and the baking stage before electrolyte filling are key processes to ensure battery performance and safety. Among them, the pre-charging process is the core link for the first charging activation of the battery cell. During this process, the electrolyte and electrode materials undergo an interfacial reaction, which inevitably generates trace amounts of gas. The baking process before electrolyte filling aims to remove moisture from the inside of the battery cell (including components such as the electrode assembly and casing) to prevent moisture from reacting with the electrolyte to generate harmful gases that affect battery performance. During this baking process, trace amounts of residual organic matter inside the battery cell and the evaporation of moisture will also generate a certain amount of gas.

[0003] To effectively expel the gas generated during the aforementioned processes, existing battery cell structures typically incorporate electrolyte drainage holes beneath the plastic under the cover plate as venting ports to guide internal gas to the outside, preventing gas accumulation and pressure buildup. However, during battery cell assembly, the electrode surfaces are usually covered with insulating tape. Unfortunately, this tape is prone to misalignment, wrinkling, or over-covering, causing physical interference between the tape and the electrolyte drainage holes beneath the cover plate. This blockage of the venting ports leads to incomplete gas release and cell bulging. Summary of the Invention

[0004] The purpose of this application is to provide a battery cell and an electrical device that solves the problem that existing battery cell structures typically have electrolyte drainage holes under the plastic cover as venting holes to guide the gas inside the battery cell to the outside. However, the insulating tape on the electrode surface and the venting holes are prone to physical interference, which can block the venting holes and cause the battery cell to bulge due to incomplete venting.

[0005] According to a first aspect of this application, a battery cell is provided, the battery cell including an electrode assembly, a cover plate, and a housing. The cover plate includes a cover plate body and a first plastic component. The first plastic component is connected to the side of the cover plate body facing the electrode assembly, and along the thickness direction, a projection of the first plastic component and the cover plate body is made onto a plane perpendicular to the thickness direction, the projection outline of the first plastic component falling completely within the projection outline range of the cover plate body. The cover plate body has a through-hole for liquid injection, and the first plastic component includes a liquid injection groove corresponding to the liquid injection hole. The first bottom wall of the liquid injection groove has a through-hole for liquid injection. The housing is connected to the cover plate body at a portion corresponding to the outer edge of its projection outline, and an venting gap exists between the housing and the first plastic component. The side wall of the liquid injection groove facing the housing has a through-hole for venting, and the venting hole communicates with the venting gap.

[0006] In any of the above technical solutions, further, the side wall of the injection tank facing the housing is provided with a positioning groove protruding into the injection tank. The positioning groove includes a second bottom wall facing the electrode assembly and a surrounding wall surrounding the second bottom wall. The surrounding wall contacts the side of the cover plate body facing the electrode assembly, and the side of the surrounding wall facing the housing is provided with an opening. The second bottom wall is provided with a vent hole penetrating through itself. The side of the cover plate body facing the electrode assembly is provided with a positioning protrusion protruding into the electrode assembly. There is a gap between the positioning protrusion and the second bottom wall, and the positioning protrusion and the surrounding wall are positioned and engaged.

[0007] In any of the above technical solutions, the cover plate further includes a length direction that is perpendicular to the thickness direction; the injection hole is disposed at the end of the cover plate body in the length direction; the injection groove is disposed at the end of the first plastic part in the length direction; the positioning groove is disposed on the side wall of the injection groove in the length direction; and the opening is provided on one side of the enclosure wall in the length direction.

[0008] In any of the above technical solutions, the cover plate further includes a width direction, and the length direction, the width direction, and the thickness direction are perpendicular to each other; the positioning protrusion is a rectangular protrusion, the positioning groove is a rectangular groove, and the enclosure includes a first positioning wall disposed opposite to the opening, and two second positioning walls that are opposite to each other in the width direction, wherein the positioning protrusion is positioned and engaged with the first positioning wall and the two second positioning walls.

[0009] In any of the above technical solutions, the cover plate further includes a thickness direction; the cover plate body includes a first step portion and a second step portion connected to each other along the thickness direction, the cross-sectional area of ​​the second step portion perpendicular to the thickness direction is smaller than the cross-sectional area of ​​the first step portion perpendicular to the thickness direction; the step surface formed at the connection between the second step portion and the first step portion is used for the housing to be installed, the enclosure wall contacts the side of the second step portion facing the electrode group, and the positioning protrusion is provided on the side of the second step portion facing the electrode group.

[0010] In any of the above technical solutions, the central region of the first bottom wall of the injection tank is positioned opposite the injection hole, the central region of the first bottom wall is a solid structure, and there are multiple injection guide holes arranged circumferentially along the solid structure.

[0011] In any of the above technical solutions, the cover plate further has a thickness direction; the distance between the positioning protrusion and the second bottom wall satisfies: d≤1.5mm, where d is the distance between the positioning protrusion and the second bottom wall in the thickness direction.

[0012] In any of the above technical solutions, the cover plate further has a thickness direction; the distance between the positioning protrusion and the second bottom wall satisfies: d≥0.5mm, where d is the distance between the positioning protrusion and the second bottom wall in the thickness direction.

[0013] In any of the above technical solutions, the cover plate body further includes an injection hole processing part, the injection hole processing part having an injection hole that penetrates itself; the positioning protrusion and the injection hole processing part are spaced apart along the length direction; the distance between the positioning protrusion and the injection hole processing part satisfies: L≥3mm, where L is the distance between the positioning protrusion and the injection hole processing part in the length direction.

[0014] According to a second aspect of this application, an electrical device is provided, including the battery cell as described above.

[0015] The battery cell of this application includes an electrode assembly, a cover plate, and a housing. The cover plate includes a cover plate body and a first plastic component. The first plastic component is connected to the side of the cover plate body facing the electrode assembly, and the outer edge of the first plastic component is located inside the outer edge of the cover plate body (i.e., along the thickness direction, the projection of the first plastic component and the cover plate body onto a plane perpendicular to the thickness direction, the projection outline of the first plastic component completely falls within the projection outline range of the cover plate body). The cover plate body has a through-hole for liquid injection, and the first plastic component includes a liquid injection groove corresponding to the liquid injection hole. The first bottom wall of the liquid injection groove has a through-hole for liquid injection. The housing is connected to the outer edge of the cover plate body (i.e., the housing is connected to the portion of the cover plate body corresponding to the outer edge of its projection outline), and there is an venting gap between the housing and the first plastic component. The side wall of the liquid injection groove facing the housing has a through-hole for venting, and the venting hole communicates with the venting gap.

[0016] Based on the above technical features, the beneficial effects of this application are as follows: The cover plate of this application adds an additional venting path to the original venting path (injection guide hole - injection tank - injection hole). Specifically, an venting hole is opened on the side wall of the injection tank facing the shell, which penetrates itself. The venting hole is connected to the venting gap, thus forming a new additional venting path (venting gap - venting hole - injection tank - injection hole). With this configuration, when the injection guide hole is blocked, the gas inside the cell can be discharged through the venting gap - venting hole - injection tank - injection hole, thus avoiding the problem of cell swelling caused by incomplete venting.

[0017] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, 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 this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 An exploded view of the cover plate according to an embodiment of this application is shown. Figure 2 Show Figure 1 Top view; Figure 3 Show Figure 2 A schematic diagram of the AA cross-sectional structure; Figure 4 Show Figure 3 Partial structural diagram; Figure 5 A schematic diagram of the exhaust path of an embodiment of this application is shown; Figure 6 A schematic diagram of the overall structure of the first plastic part according to an embodiment of this application is shown; Figure 7 Show Figure 6 Partial structural diagram; Figure 8 A schematic diagram of the overall structure of the cover plate body according to an embodiment of this application is shown; Figure 9 Show Figure 8 Top view; Figure 10 Show Figure 6 Top view.

[0020] Icons: 100-Cover plate body; 110-Injection hole processing part; 111-Protrusion; 112-Injection hole; 113-Annular groove; 131-First step part; 132-Second step part; 133-Positioning protrusion; 200-First plastic part; 210-Injection groove; 211-Injection guide hole; 212-First bottom wall; 213-Side wall; 220-Positioning groove; 221-Second bottom wall; 222-Enclosure wall; 2221-First positioning wall; 2222-Second positioning wall; 223-Vent hole; 300-Second plastic part; 400-Riveting block; 500-Pole post; X-Length direction; Y-Width direction; Z-Thickness direction. Detailed Implementation

[0021] The following detailed embodiments are provided to help the reader gain a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will be apparent after understanding the disclosure of this application. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein; changes that will be apparent after understanding the disclosure of this application are possible, except for operations that must occur in a specific order. Furthermore, for clarity and brevity, descriptions of features known in the art may be omitted.

[0022] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein that will be apparent upon understanding the disclosure of this application.

[0023] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, it may be directly "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, or there may be one or more other elements in between. In contrast, when an element is described as being "directly on" another element, "directly connected to" another element, "directly bonded to" another element, "directly on" another element, or "directly covering" another element, there may be no other elements in between.

[0024] As used herein, the term “and / or” includes any one of the relevant items listed and any combination of any two or more items.

[0025] Although terms such as “first,” “second,” and “third” may be used herein to describe individual components, assemblies, regions, layers, or parts, these components, assemblies, regions, layers, or parts are not limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or part from another. Therefore, without departing from the teachings of the examples described herein, the first component, assembly, region, layer, or part referred to as the second component, assembly, region, layer, or part may also be referred to as the second component, assembly, region, layer, or part.

[0026] For ease of description, spatial relation terms such as “above,” “upper,” “below,” and “lower” are used herein to describe the relationship between one element and another, as shown in the accompanying drawings. Such spatial relation terms are intended to include not only the orientation depicted in the drawings but also different orientations of the device during use or operation. For example, if the device in the drawings is flipped, an element described as being “above” or “upper” relative to another element will subsequently be “below” or “lower” relative to that other element. Therefore, the term “above” includes both “above” and “below” orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relation terms used herein will be interpreted accordingly.

[0027] The terminology used herein is for the purpose of describing various examples only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms “comprising,” “including,” and “having” enumerate the stated features, quantities, operations, components, elements, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0028] Variations in the shapes shown in the accompanying drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but include changes in shape that may occur during manufacturing.

[0029] The features of the examples described herein can be combined in various ways that will be apparent upon understanding the disclosure of this application. Furthermore, although the examples described herein have a wide variety of constructions, other constructions are possible, as will be apparent upon understanding the disclosure of this application.

[0030] The first aspect of this application provides a battery cell that solves the problem that existing battery cell structures typically have electrolyte drainage holes under the plastic cover as venting holes to guide gas inside the cell to the outside. However, the insulating tape on the electrode surface easily interferes with the venting holes, thus blocking them and causing incomplete venting and cell bulging. See below for reference. Figures 1 to 10 The cover plate described according to some embodiments of this application is further illustrated. Additionally, for ease of description, the cover plate will hereinafter be described as having a length direction X, a width direction Y, and a thickness direction that are perpendicular to each other.

[0031] like Figures 3 to 7As shown, the battery cell of this application includes an electrode assembly, a cover plate, and a housing (the electrode assembly and housing are not shown in the figure). The cover plate includes a cover plate body 100 (e.g., a plain aluminum plate) and a first plastic part 200. The first plastic part 200 is connected to one side of the cover plate body 100 facing the electrode assembly, and the outer edge of the first plastic part 200 is located inside the outer edge of the cover plate body 100 (that is, along the thickness direction Z, the projection of the first plastic part 200 and the cover plate body 100 onto a plane perpendicular to the thickness direction Z, and the projection outline of the first plastic part 200 completely falls within the projection outline range of the cover plate body 100); the cover plate body 100 has a liquid injection hole 112 that penetrates itself, and the first plastic part 200 includes a liquid injection groove 210 corresponding to the liquid injection hole 112. The first bottom wall 212 of the liquid injection groove 210 has a liquid injection guide hole 211 that penetrates itself; the shell is connected to the outer edge of the cover plate body 100 (that is, the shell is connected to the part of the cover plate body 100 corresponding to the outer edge of its projection outline), and there is an exhaust gap between the shell and the first plastic part 200. The side wall 213 of the liquid injection groove 210 facing the shell has an exhaust hole 223 that penetrates itself, and the exhaust hole 223 communicates with the exhaust gap.

[0032] With this configuration, the cover plate of this application adds an additional venting path to the original venting path (injection guide hole 211 - injection tank 210 - injection hole 112). Specifically, an venting hole 223 is provided through the injection tank 210 on its side wall 213 facing the housing. The venting hole 223 communicates with the venting gap, thus forming a new additional venting path (venting gap - venting hole 223 - injection tank 210 - injection hole 112). With this configuration, when the injection guide hole 211 is blocked, such as... Figure 4 and Figure 5 As shown, the gas inside the battery cell can be discharged through the venting gap-venting hole 223-injection tank 210-injection hole 112 to avoid the problem of battery cell swelling caused by incomplete venting.

[0033] Furthermore, in the embodiments of this application, such as Figures 4 to 7 As shown, the side wall 213 of the injection tank 210 facing the housing is provided with a positioning groove 220 protruding into the injection tank 210. The positioning groove 220 includes a second bottom wall 221 facing the electrode assembly and a surrounding wall 222 surrounding the second bottom wall 221. The surrounding wall 222 contacts the side of the cover plate body 100 facing the electrode assembly, and the side of the surrounding wall 222 facing the housing is provided with an opening. The second bottom wall 221 has a vent 223 penetrating through it. Figure 4 and Figure 8 As shown, a positioning protrusion 133 protruding towards the electrode group is provided on the side of the cover plate body 100 facing the electrode group. A gap is provided between the positioning protrusion 133 and the second bottom wall 221 (so as not to affect the exhaust path), and the positioning protrusion 133 is positioned and engaged with the enclosure wall 222.

[0034] With this configuration, the surrounding wall 222 of the positioning groove 220 contacts the side of the cover plate body 100 facing the electrode assembly, and an opening is provided on the side facing the housing to connect the venting gap and the venting port. When the liquid injection guide hole 211 is blocked, such as Figure 4 and Figure 5 As shown, the gas inside the battery cell can be discharged through the venting gap - the opening of the positioning groove 220 - the venting hole 223 of the positioning groove 220 - the liquid injection tank 210 - the liquid injection hole 112, so as to avoid the problem of battery cell swelling caused by incomplete venting.

[0035] Furthermore, the side of the wall 222 of the positioning groove 220 facing the shell has an open opening, and the other side walls 222 are in contact with the side of the cover plate body 100 facing the electrode assembly. The positioning protrusion 133 on the side of the cover plate body 100 facing the electrode assembly is positioned and engaged with the wall 222. With this arrangement, the positioning protrusion 133 and the wall 222 are positioned and engaged (equivalent to adding an anti-rotation structure) to limit the first plastic part 200 and prevent its horizontal displacement. This solves the problem in the prior art that the first plastic part 200 is too long and the non-electrode end (injection hole side) of the first plastic part 200 will shift after the parts are assembled and riveted.

[0036] In the embodiments of this application, such as Figures 3 to 7 As shown, the injection hole 112 is located at the end of the cover plate body 100 in the length direction X, the injection groove 210 is located at the end of the first plastic part 200 in the length direction X, and the positioning groove 220 is located on the side wall 213 of the injection groove 210 in the length direction X; one side of the enclosure wall 222 in the length direction X has an opening. With this configuration, the enclosure wall 222 has an opening on one side in the length direction X, while the other sides are solid enclosure wall 222 structures. The positioning protrusion 133 is positioned and engaged with the enclosure wall 222 (equivalent to adding an anti-rotation structure) to limit the first plastic part 200 and prevent its horizontal displacement.

[0037] In addition, the positioning groove 220 of this application can be a circular groove or a rectangular groove, as long as the side of the positioning groove 220 facing the shell and in the length direction X is provided with an open opening, and the other sides are solid enclosure wall 222 structures.

[0038] The following description uses a rectangular groove, such as the positioning groove 220, as an example. Figure 7 and Figure 8As shown, the positioning protrusion 133 is a rectangular protrusion, the positioning groove 220 is a rectangular groove, and the enclosure wall 222 includes a first positioning wall 2221 opposite to the opening, and two second positioning walls 2222 opposite to each other in the width direction Y. The positioning protrusion 133 is positioned and engaged with the first positioning wall 2221 and the two second positioning walls 2222. This arrangement is equivalent to adding anti-rotation structures in the length direction X and the width direction Y to limit the first plastic part 200 and prevent its horizontal displacement.

[0039] In the embodiments of this application, such as Figure 4 As shown, the cover plate body 100 includes a first step portion 131 and a second step portion 132 connected to each other along the thickness direction Z. The cross-sectional area of ​​the second step portion 132 perpendicular to the thickness direction Z is smaller than the cross-sectional area of ​​the first step portion 131 perpendicular to the thickness direction Z. The step surface formed at the connection between the second step portion 132 and the first step portion 131 is used for housing installation. The outer edge of the first plastic part 200 is disposed inside the outer edge of the second step portion 132, and the enclosure wall 222 contacts the side of the second step portion 132 facing the electrode assembly. The positioning protrusion 133 is disposed on the side of the second step portion 132 facing the electrode assembly.

[0040] In the embodiments of this application, such as Figure 5 As shown, the distance between the positioning protrusion 133 and the second bottom wall 221 satisfies the following condition: d ≤ 1.5 mm, where d is the distance between the positioning protrusion 133 and the second bottom wall 221 in the thickness direction Z. If d > 1.5 mm, the positioning accuracy will decrease, and an excessive gap will allow for loosening and misalignment of the fit between the two, making the first plastic part prone to horizontal displacement during assembly or use. Furthermore, the distance between the positioning protrusion 133 and the second bottom wall 221 should also satisfy: d ≥ 0.5 mm. If d < 0.5 mm, it will interfere with the vent hole 223, affecting venting efficiency.

[0041] In the embodiments of this application, such as Figure 4 , Figure 8 and Figure 9 As shown, the cover plate body 100 includes a liquid injection hole processing part 110, which has a liquid injection hole that penetrates itself. The liquid injection hole processing part 110 can be formed by stamping, and includes a protrusion 111 formed by stamping that protrudes from the side facing the electrode assembly, and an annular groove 113 naturally formed around the protrusion 111.

[0042] like Figure 9As shown, the positioning protrusion 133 and the injection hole processing part 110 are spaced apart along the length direction X. Considering its manufacturing process, the distance between the positioning protrusion 133 and the injection hole processing part 110 satisfies: L≥3mm, where L is the distance between the positioning protrusion 133 and the injection hole processing part 110 (annular groove 113) in the length direction X.

[0043] Additionally, in the embodiments of this application, such as Figure 4 and Figure 10 As shown, the middle region of the first bottom wall 212 of the injection tank 210 of the first plastic part 200 is set directly opposite the injection hole 112. In order to prevent the electrolyte from impacting the electrode group and causing damage to the electrode sheet during the battery cell injection process, the middle region of the first bottom wall 212 of this application is a solid region, and multiple injection guide holes 211 are provided around the solid region.

[0044] like Figure 1 and Figure 2 As shown, the cover plate of this application also includes a pole post 500, a second plastic part 300 and a riveting block 400. The pole post 500 passes through the through holes of the first plastic part 200, the cover plate body 100, the second plastic part 300 and the riveting block 400 in sequence, and is riveted to the riveting block 400.

[0045] In summary, the cover plate of this application adds an additional venting path to the existing venting path (injection guide hole 211 - injection tank 210 - injection hole 112). Specifically, an venting hole 223 is provided through the injection tank 210 on its side wall 213 facing the housing. The venting hole 223 communicates with the venting gap, thus forming a new additional venting path (venting gap - venting hole 223 - injection tank 210 - injection hole 112). With this configuration, when the injection guide hole 211 is blocked, such as... Figure 4 and Figure 5 As shown, the gas inside the battery cell can be discharged through the venting gap-venting hole 223-injection tank 210-injection hole 112 to avoid the problem of battery cell swelling caused by incomplete venting.

[0046] According to a second aspect of this application, an electrical device is provided, including the battery cell as described above.

[0047] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the scope of the technology disclosed in this application, or make equivalent substitutions for some of the technical features. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the protection scope of this application.

Claims

1. A battery cell, characterized in that, The battery cell includes an electrode assembly, a cover plate, and a housing. The cover plate has a thickness direction and includes a cover plate body and a first plastic part connected to each other in the thickness direction. The first plastic part is connected to the side of the cover plate body facing the pole group, and along the thickness direction, the first plastic part and the cover plate body are projected onto a plane perpendicular to the thickness direction, and the projection outline of the first plastic part falls completely within the projection outline range of the cover plate body. The cover plate body has a liquid injection hole that penetrates itself, and the first plastic part includes a liquid injection groove corresponding to the liquid injection hole. The first bottom wall of the liquid injection groove has a liquid injection guide hole that penetrates itself. The housing is connected to the cover plate body at the part corresponding to the outer edge of its projected outline, and there is an exhaust gap between the housing and the first plastic part. The side wall of the injection tank facing the housing has an exhaust hole that penetrates itself, and the exhaust hole is connected to the exhaust gap.

2. The battery cell according to claim 1, characterized in that, The side wall of the injection tank facing the housing is provided with a positioning groove protruding into the injection tank. The positioning groove includes a second bottom wall facing the electrode assembly and a surrounding wall surrounding the second bottom wall. The enclosure wall contacts the side of the cover plate body facing the electrode assembly, and the side of the enclosure wall facing the housing is provided with an opening, and the second bottom wall is provided with the exhaust hole that penetrates itself. The cover plate body has a positioning protrusion protruding towards the pole group on the side facing the pole group. There is a gap between the positioning protrusion and the second bottom wall, and the positioning protrusion is positioned and engaged with the enclosure wall.

3. The battery cell according to claim 2, characterized in that, The cover plate also has a length direction, which is perpendicular to the thickness direction; The injection hole is located at the end of the cover plate body in the length direction, the injection groove is located at the end of the first plastic part in the length direction, and the positioning groove is located on the side wall of the injection groove in the length direction. The opening is provided on one side of the enclosure along its length.

4. The battery cell according to claim 3, characterized in that, The cover plate also has a width direction, and the length direction, the width direction and the thickness direction are perpendicular to each other; The positioning protrusion is a rectangular protrusion, the positioning groove is a rectangular groove, and the enclosure includes a first positioning wall disposed opposite to the opening and two second positioning walls opposite to each other in the width direction. The positioning protrusion is positioned and engaged with the first positioning wall and the two second positioning walls.

5. The battery cell according to claim 3, characterized in that, The cover plate body includes a first step portion and a second step portion connected to each other along the thickness direction, wherein the cross-sectional area of ​​the second step portion perpendicular to the thickness direction is smaller than the cross-sectional area of ​​the first step portion perpendicular to the thickness direction. The stepped surface formed at the connection between the second stepped portion and the first stepped portion is used for mounting the housing. The enclosure wall contacts the side of the second stepped portion facing the electrode group, and the positioning protrusion is provided on the side of the second stepped portion facing the electrode group.

6. The battery cell according to claim 3, characterized in that, The middle region of the first bottom wall of the injection tank is positioned directly opposite the injection hole. The middle region of the first bottom wall is a solid structure. There are multiple injection guide holes, which are arranged circumferentially along the solid structure.

7. The battery cell according to any one of claims 2-6, characterized in that, The distance between the positioning protrusion and the second bottom wall satisfies: d≤1.5mm, where d is the distance between the positioning protrusion and the second bottom wall in the thickness direction.

8. The battery cell according to any one of claims 2-6, characterized in that, The distance between the positioning protrusion and the second bottom wall satisfies: d ≥ 0.5 mm, where d is the distance between the positioning protrusion and the second bottom wall in the thickness direction.

9. The battery cell according to any one of claims 3-6, characterized in that, The cover plate body includes a liquid injection hole processing part, and the liquid injection hole processing part has a liquid injection hole that penetrates itself; The positioning protrusion and the injection hole processing part are spaced apart along the length direction; The distance between the positioning protrusion and the injection hole processing part satisfies: L≥3mm, where L is the distance between the positioning protrusion and the injection hole processing part in the length direction.

10. An electrical appliance, characterized in that, Includes the battery cell as described in any one of claims 1-9.

Images