Battery cell, battery module and battery pack

Abstract

The utility model provides a battery cell, a battery module and a battery pack, and relates to the field of battery cell structures. The battery cell comprises a shell, a pole group is arranged in the shell, tabs are formed at the two ends of the pole group in the length direction, and the tabs are fixedly connected with a pole piece group; the anti-explosion valve is positioned at the end part of the shell in the width direction; and the cover plate assembly is correspondingly connected with the pole piece group. According to the invention, the pole piece group (namely the pole and the connecting sheet) is directly and fixedly connected with the tab, and then the cover plate assembly is correspondingly connected with the pole piece group, so that an assembly space does not need to be reserved in advance, and the space utilization rate in the battery cell is effectively improved; in addition, the anti-explosion valve is arranged at the end of the shell in the width direction, the length of the exhaust channel is effectively shortened, rapid exhaust can be achieved, and then the probability that the exhaust channel is blocked is reduced.

Description

Technical Field

[0001] The present application relates to the field of battery cell structures, and in particular to a battery cell, a battery module and a battery pack. Background Art

[0002] In existing battery cells, the explosion-proof valve is usually arranged at the cover plate assembly, which makes the exhaust passage prone to blockage. In addition, in the assembly process of existing battery cells, the pole column and the connecting piece are usually fixedly connected to components such as the riveting block and the upper plastic part in the cover plate assembly to form an integral body, and then the tab of the electrode group is correspondingly connected to the integral body, and then the integral body is folded over to be correspondingly assembled with the battery cell housing. In this way, sufficient space needs to be reserved, resulting in low space utilization rate inside the battery cell and being not conducive to the improvement of the battery cell capacity. Summary of the Utility Model

[0003] In view of this, the purpose of the present application is to provide a battery cell, a battery module and a battery pack to solve the problems that in existing battery cells, arranging the explosion-proof valve at the cover plate assembly easily causes blockage of the exhaust passage, and the way of fixing the pole column and the connecting piece to the cover plate assembly and then assembling with the tab will result in low space utilization rate inside the battery cell.

[0004] According to the above purpose, the first aspect of the present utility model provides a battery cell, wherein the battery cell includes:

[0005] A housing, inside which an electrode group is arranged, tabs are formed at both ends in the length direction of the electrode group, and the tabs are fixedly connected to the pole column assembly;

[0006] An explosion-proof valve, located at the end of the housing in the width direction; and

[0007] A cover plate assembly, correspondingly connected to the pole column assembly.

[0008] Preferably, the pole column assembly includes a pole column and a connecting piece, the pole column is formed into a variable-diameter structure, and the connecting piece is formed with a first connecting portion and a second connecting portion connected in sequence.

[0009] Preferably, the large-diameter end of the pole column is close to the electrode group, and the first connecting portion is welded to the bottom of the large-diameter end of the pole column close to the electrode group.

[0010] Preferably, along the length direction of the electrode group, the thickness of the large-diameter end of the pole column is formed as D, and 1 mm ≤ D ≤ 2 mm.

[0011] Preferably, along the width direction of the electrode group, the second connecting portion protrudes from the pole column, and the tab is formed into a bent structure and welded to the top of the second connecting portion away from the electrode group.

[0012] Preferably, the distance between the bottom of the second connecting part close to the bottom of the electrode group and the bottom of the tab is L, where 0.5 mm ≤ L ≤ 1.2 mm.

[0013] Preferably, the cover plate assembly includes a riveting block, an upper plastic part, a cover plate body, a lower plastic part and a sealing ring that are correspondingly assembled with the pole piece group.

[0014] Preferably, the thickness of the lower plastic part is H, where 2.5 mm ≤ H ≤ 4 mm.

[0015] According to a second aspect of the present invention, there is provided a battery module, wherein the battery module includes the battery cell as described above.

[0016] According to a third aspect of the present invention, there is provided a battery pack, wherein the battery pack is provided with the battery module as described above.

[0017] According to the battery cell, battery module and battery pack of the present invention, the pole piece group (i.e., the pole and the connecting piece) is directly fixedly connected to the tab, and then the cover plate assembly is correspondingly connected to the pole piece group. In this way, there is no need to reserve an assembly space in advance, thereby effectively improving the space utilization rate inside the battery cell; in addition, the explosion-proof valve is arranged at the end of the width direction of the housing, effectively shortening the length of the exhaust passage, so as to enable rapid exhaust, and further reducing the probability of blockage of the exhaust passage.

[0018] In order to make the above objects, features and advantages of the present application more obvious and understandable, the following specifically enumerates preferred embodiments and, in conjunction with the accompanying drawings, is described in detail as follows. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0020] Figure 1 is a schematic diagram of a battery cell according to an embodiment of the present invention;

[0021] Figure 2 is a partial cross-sectional view of the battery cell from a first perspective according to an embodiment of the present invention;

[0022] Figure 3 is a partial cross-sectional view of the battery cell from a second perspective according to an embodiment of the present invention.

[0023] Icon: 1 - housing; 2 - electrode group; 20 - tab; 21 - terminal; 22 - connecting piece; 220 - first connecting part; 221 - second connecting part; 3 - cover plate assembly; 30 - riveting block; 31 - upper plastic part; 32 - cover plate body; 33 - lower plastic part; 34 - sealing ring; 4 - explosion - proof valve. Detailed implementation manners

[0024] The following detailed implementation manners are provided to help the reader obtain a comprehensive understanding of the methods, devices, and / or systems described herein. However, after understanding the disclosure of this application, various changes, modifications, and equivalents of the methods, devices, and / or systems described herein will be obvious. For example, the order of operations described herein is merely exemplary and is not limited to the order set forth herein. Rather, changes that will be obvious after understanding the disclosure of this application can be made, except for operations that must occur in a specific order. In addition, descriptions of features known in the art may be omitted for the sake of clarity and conciseness.

[0025] The features described herein may be implemented in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein are provided only to illustrate some of the many possible ways of implementing the methods, devices, and / or systems described herein that will be obvious after understanding the disclosure of this application.

[0026] Throughout the specification, when an element (such as, a layer, a region, or a substrate) is described as "on" another element, "connected to" another element, "coupled to" another element, "above" another element, or "covering" another element, it may be directly "on", "connected to", "coupled to", "above", or "covering" another element, or there may be one or more other elements between them. In contrast, when an element is described as "directly on", "directly connected to", "directly coupled to", "directly above", or "directly covering" another element, there may be no other elements between them.

[0027] As used herein, the term "and / or" includes any one of the listed related items and any combination of any two or more of them.

[0028] Although terms such as "first", "second", and "third" may be used herein to describe various components, elements, regions, layers, or sections, these components, elements, regions, layers, or sections are not limited by these terms. Rather, these terms are only used to distinguish one component, element, region, layer, or section from another. Thus, a first component, element, region, layer, or section as referred to in the examples described herein may also be termed a second component, element, region, layer, or section without departing from the teachings of the examples.

[0029] For ease of description, spatial relationship terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another as shown in the figures. Such spatial relationship terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, an element described as "above" or "upper" relative to another element will then be "below" or "lower" relative to the other element. Thus, the term "above" includes both the orientation of "above" and "below" depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or at other orientations), and the spatial relationship terms used herein will be interpreted accordingly.

[0030] The terms used herein are for the purpose of describing various examples only and are not intended to limit the disclosure. Unless the context clearly dictates otherwise, the singular forms are also intended to include the plural forms. The terms "comprises", "comprising", and "having" list the stated features, quantities, operations, components, elements, and / or combinations thereof that exist, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0031] Due to manufacturing techniques and / or tolerances, variations in the shapes shown in the figures may occur. Thus, the examples described herein are not limited to the specific shapes shown in the figures, but include changes in shape that occur during manufacturing.

[0032] The features of the examples described herein may be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations are possible as will be apparent after understanding the disclosure of the present application.

[0033] According to a first aspect of the present utility model, a battery cell is provided, such as Figures 1 to 3As shown in the figure, the battery cell in this embodiment includes a housing 1, an explosion-proof valve 4 provided at the end in the width direction of the housing 1, and a cover plate assembly 3. A pole group 2 is further provided inside the housing 1. In the following text, the specific structures of the above-mentioned parts of the battery cell according to the present invention will be described in detail.

[0034] As Figures 2 to 3 shown in the figure, pole ears 20 (i.e., a positive pole ear 20 and a negative pole ear 20) are formed at both ends in the length direction of the pole group 2 in this embodiment. Both of the two pole ears 20 are fixedly connected with a pole post 21 component group. Specifically, the pole post 21 component group includes a pole post 21 and a connecting piece 22. The pole post 21 is formed into a stepped diameter structure to improve the stability of its connection with the connecting piece 22 and the pole ear 20. The connecting piece 22 is formed with a first connecting portion 220 and a second connecting portion 221 that are sequentially connected. More specifically, the large-diameter end of the pole post 21 is arranged close to the pole group 2, and the first connecting portion 220 of the connecting piece 22 is welded to the bottom of the large-diameter end of the pole post 21 close to the pole group 2. At this time, along the width direction of the pole group 2 (i.e., the extending direction of the following cover plate assembly 3), the second connecting portion 221 protrudes from the pole post 21, and the pole ear 20 is formed into a bent structure and welded to the top of the second connecting portion 221 away from the pole group 2. In this way, the fixed connection between the pole post 21 component group and the pole ear 20 is realized.

[0035] In order to improve the structural strength of the pole post 21 component group itself and the stability of its connection with the pole ear 20, preferably, along the length direction of the pole group 2 (i.e., the axial direction of the pole post 21), the thickness of the large-diameter end of the pole post 21 is formed as D, where 1 mm ≤ D ≤ 2 mm; the distance between the bottom of the second connecting portion 221 close to the pole group 2 and the bottom of the pole ear 20 is formed as L, where 0.5 mm ≤ L ≤ 1.2 mm. The above numerical range is the optimal range obtained after multiple tests, but its specific size is not fixed and should be determined comprehensively according to actual situations such as the size of the housing 1 and the battery cell specifications.

[0036] In addition, in this embodiment, the cover plate assembly 3 includes a riveting block 30, an upper plastic part 31, a cover plate body 32, a lower plastic part 33, and a sealing ring 34 that are correspondingly assembled with the above-mentioned pole post 21 component group. After the pole post 21 component group is fixedly connected to the pole ear 20, the above-mentioned components in the cover plate assembly 3 are sequentially assembled with the pole post 21. In this way, 2 mm to 4 mm of space (along the length direction of the battery cell) can be saved at both ends in the length direction of the battery cell.

[0037] It should be noted that, in order to better achieve the above technical effects, in this embodiment, the thickness of the lower plastic part 33 is formed as H, where 2.5 mm ≤ H ≤ 4 mm, so as to ensure the structural stability of the overall battery cell while avoiding excessive space occupation by the cover plate assembly 3. In addition, the connection position between the pole column 21 and the riveting block 30 in this embodiment is fixed by a welding process, and the riveting block 30 is formed into a copper-aluminum composite plate part, so as to improve the welding strength and welding stability while simplifying the process and achieving a certain degree of cost reduction.

[0038] According to the battery cell of the present invention, the pole column 21 component group (i.e., the pole column 21 and the connecting piece 22) is directly fixedly connected to the tab 20, and then the cover plate assembly 3 is correspondingly connected to the pole column 21 component group. In this way, there is no need to reserve an assembly space in advance, thereby effectively improving the space utilization rate inside the battery cell. In addition, the explosion-proof valve 4 is arranged at the end of the housing 1 in the width direction (compared with being arranged at the end in the length direction), effectively shortening the length of the exhaust passage, so as to achieve rapid exhaust and further reduce the probability of blockage of the exhaust passage.

[0039] According to a second aspect of the present invention, a battery module is provided, and the battery module includes the battery cell as described above.

[0040] According to a third aspect of the present invention, a battery pack is provided, and the battery pack is provided with the battery module as described above.

[0041] Finally, it should be noted that: the above-described embodiments are only specific implementation manners of the present application, used to illustrate the technical solutions of the present application, rather than limiting it. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: any person skilled in the art within the technical scope disclosed by the present application can still modify the technical solutions recorded in the foregoing embodiments, or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A battery cell, characterized in that: The battery cell comprises: A shell, wherein a pole group is arranged inside the shell, pole ears are formed at both ends of the pole group in the length direction, and the pole ears are fixedly connected to the pole column group; an explosion-proof valve located at an end portion in a width direction of the housing; and The cover plate assembly is connected correspondingly to the pole piece assembly.

2. The battery cell according to claim 1, characterized in that: The pole component group includes a pole and a connecting piece. The pole is formed into a variable diameter structure. The connecting piece is formed with a first connecting portion and a second connecting portion connected in sequence.

3. The battery cell according to claim 2, characterized in that: The large diameter end of the pole is close to the pole group, and the first connecting portion is welded to the large diameter end of the pole close to the bottom of the pole group.

4. The battery cell according to claim 3, characterized in that: Along the length direction of the pole group, the thickness of the large diameter end of the pole is formed to be D, 1mm≤D≤2mm.

5. The battery cell according to claim 3, characterized in that: Along the width direction of the electrode group, the second connection portion protrudes from the electrode column, and the electrode ear is formed into a bent structure and is welded to the top of the second connection portion away from the electrode group.

6. The battery cell according to claim 5, characterized in that: The distance between the bottom of the second connecting portion close to the electrode group and the bottom of the electrode ear is formed to be L, and 0.5 mm≤L≤1.2 mm.

7. The battery cell according to claim 3, characterized in that: The cover plate assembly comprises a riveting block, an upper plastic part, a cover plate body, a lower plastic part and a sealing ring which are assembled corresponding to the pole member group.

8. The battery cell according to claim 7, characterized in that: The thickness of the lower plastic part is formed to be H, 2.5 mm≤H≤4 mm.

9. A battery module, characterized in that: The battery module comprises the battery cell according to any one of claims 1 to 8.

10. A battery pack, characterized in that: The battery pack is provided with the battery module as claimed in claim 9.

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