Battery cell, battery cell module and battery pack

Abstract

The utility model provides a battery cell, a battery cell module and a battery pack, and relates to the field of battery cell structures. The battery cell comprises a pole, a limiting part and an overflowing part which are sequentially connected in the first direction are formed on the pole, the cross section of the limiting part and the cross section of the overflowing part are both in an oval shape, and the area of the cross section of the limiting part is larger than that of the cross section of the overflowing part; the longitudinal section of the pole is formed into a T-shaped structure; the cover plate assembly is arranged on the outer side part of the pole in a sleeving manner; the cover plate assembly comprises a welding block, a first welding hole corresponding to the flow passing part is formed in the welding block, and the flow passing part is inserted into the first welding hole and welded to the welding block. In the first direction, a gap is formed between the end face, away from the limiting part, of the overflowing part and the second end, away from the limiting part, of the first welding hole, and the height of the gap is not smaller than 0.15 mm.

Description

A battery cell, a battery cell module and a battery pack Technical Field

[0001] This application relates to the field of battery cell structure, and in particular to a battery cell, a battery cell module, and a battery pack. Background Technology

[0002] With the development of technology, people are becoming increasingly eager for faster battery charging times. However, the current blade battery is characterized by its thinness, and its terminals are usually set in a cylindrical shape (i.e., the cross-section of the existing terminals is usually circular). This type of terminal cannot meet the overcurrent requirements. In addition, the terminals and the riveting blocks are riveted together, and the vibration of the riveting can easily damage the performance of the battery cell. Furthermore, the terminals of the existing structure cannot be processed in one go and require secondary processing, which results in higher costs. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a battery cell, a battery cell module and a battery pack to solve the problems that the cylindrical terminals of existing battery cells cannot meet the overcurrent requirements and that the existing connection method of riveting terminals and riveting blocks is prone to damaging the performance of battery cells.

[0004] In accordance with the above objectives, a first aspect of this utility model provides a battery cell, wherein the battery cell comprises:

[0005] The pole post has a limiting part and a flow passage part connected sequentially along a first direction. The cross-sections of the limiting part and the flow passage part are both elliptical, and the cross-sectional area of ​​the limiting part is larger than the cross-sectional area of ​​the flow passage part, so that the longitudinal section of the pole post is formed into a T-shaped structure.

[0006] A cover plate assembly is sleeved on the outer side of the pole post; the cover plate assembly includes a welding block, the welding block having a first welding hole corresponding to the flow passage, the flow passage being inserted into the first welding hole and welded to the welding block; along the first direction, a gap is formed between the end face of the flow passage away from the limiting part and the second end of the first welding hole away from the limiting part, the height of the gap being not less than 0.15mm;

[0007] An electrode assembly is formed with electrode tabs, which are welded to the current-passing section.

[0008] Preferably, the welding block has a second welding hole communicating with the first welding hole, and the electrode tab passes through the second welding hole and the first welding hole before being welded to the flow passage.

[0009] Preferably, along the first direction, the first welding hole penetrates the first end of the welding block near the limiting portion, and the second welding hole penetrates the second end of the welding block away from the limiting portion.

[0010] Preferably, a first recess is formed around the outer side of the welding block, and the first recess extends along the first direction to the end face of the first end of the welding block.

[0011] Preferably, the cover plate assembly includes a sealing ring correspondingly sleeved on the outer side of the flow passage; along the first direction, the second end of the sealing ring away from the limiting portion abuts against the first end of the welding block;

[0012] The outer side of the sealing ring is surrounded by a second recess, which extends along the first direction to the end face of the first end of the sealing ring.

[0013] Preferably, the cover plate assembly includes a cover plate body, which is pressed onto the second recess of the sealing ring.

[0014] Preferably, a lower plastic sheet is provided within the space enclosed by the cover plate body, the sealing ring, and the welding block;

[0015] A third recess is formed around the outer side of the lower plastic, the third recess extending along the first direction to the end face of the first end of the lower plastic, and the cover plate body has a stepped structure corresponding to and connected to the third recess.

[0016] Preferably, the cover plate assembly further includes an upper plastic, wherein a first mounting hole is formed on the end face of a first end of the upper plastic along the first direction, and the first mounting hole is adapted to correspond with the limiting portion; a second mounting hole is formed on the end face of a second end of the upper plastic, and the second mounting hole is adapted to correspond with the flow portion; the first mounting hole and the second mounting hole are in communication.

[0017] When the upper plastic is connected to the corresponding pole, the end face of the second end of the upper plastic abuts against the cover plate body and the first end of the sealing ring.

[0018] According to a second aspect of the present invention, a battery cell module is provided, wherein the battery cell module includes the battery cells as described above.

[0019] According to a third aspect of the present invention, a battery pack is provided, wherein the battery pack is provided with a cell module as described above.

[0020] According to the present invention, the battery cell, battery cell module, and battery pack have an elongated cylindrical structure for the battery cell's terminal post, meaning that the cross-section of any part of the terminal post is elongated. This effectively increases the cross-sectional area of ​​the terminal post (compared to existing cylindrical terminal posts), thereby effectively improving the current carrying capacity of the terminal post to meet the usage requirements of the battery cell. In addition, the terminal post of the battery cell in the present invention is welded and fixed to the welding block. The longitudinal section of the terminal post is set as a T-shaped structure. Then, through structural cooperation, the remaining components of the cover plate assembly can be fixed between the terminal post and the welding block. Furthermore, the electrode tabs of the electrode assembly can also pass through the welding block and be welded to the terminal post. This connection method (compared to the existing connection through riveting blocks) can effectively avoid damage to the battery cell performance caused by riveting vibration.

[0021] 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

[0022] 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.

[0023] Figure 1 is a top view of a battery cell according to an embodiment of the present invention;

[0024] Figure 2 is a partial cross-sectional view of the battery cell along the AA direction according to an embodiment of the present invention;

[0025] Figure 3 is a partial cross-sectional view of the battery cell along the BB direction according to an embodiment of the present invention;

[0026] Figure 4 is a schematic diagram of the negative electrode post according to an embodiment of the present invention;

[0027] Figure 5 is a cross-sectional view of the negative electrode post according to an embodiment of the present invention;

[0028] Figure 6 is a cross-sectional view of the positive electrode post according to an embodiment of the present invention.

[0029] Icons: 1-Pole post; 11-Flow passage; 12-Limiting part; 21-Welding block; 211-First recess; 212-First welding hole; 213-Second welding hole; 22-Sealing ring; 221-Second recess; 23-Lower plastic; 231-Third recess; 24-Cover plate body; 241-Step structure; 25-Upper plastic; 251-First assembly hole; 252-Second assembly hole; 31-Pole tab. Detailed Implementation

[0030] 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.

[0031] 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.

[0032] 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.

[0033] As used herein, the term “and / or” includes any one of the relevant items listed and any combination of any two or more items.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] According to a first aspect of the present invention, a battery cell is provided, comprising a terminal post 1, a cover plate assembly, and other structures. In this embodiment, the cross-section of any part of the terminal post 1 is formed into an elliptical structure, thereby effectively increasing the cross-sectional area of ​​the terminal post 1 under limited battery cell specifications, and thus effectively improving the current carrying capacity of the terminal post 1. Furthermore, in this embodiment, the longitudinal section of the terminal post 1 is formed into a T-shaped structure, which is fixed to the cover plate assembly by welding with a welding block 21. The specific structure of the above-mentioned parts of the battery cell according to the present invention will be described in detail below.

[0040] In this embodiment, as shown in Figures 1 to 6, the pole post 1 is formed with a limiting part 12 and a flow passage part 11 connected sequentially along a first direction (i.e., the direction indicated by the arrows in Figures 2 to 6). The cross-sections of the limiting part 12 and the flow passage part 11 are actually formed as elongated ovals (i.e., the cross-sections of the limiting part 12 and the flow passage part 11 are composed of two parallel line segments and two corresponding semi-circular arc segments). Furthermore, the cross-sectional area of ​​the limiting part 12 is larger than the cross-sectional area of ​​the flow passage part 11, so that the longitudinal section of the pole post 1 is formed as a T-shaped structure.

[0041] The cover plate assembly is sleeved on the outer side of the pole post 1. The cover plate assembly specifically includes a cover plate body 24, an upper plastic 25, a lower plastic 23, a sealing ring 22, and a welding block 21. As shown in Figures 2 and 3, along the first direction, the end face of the first end of the welding block 21 (near the limiting part 12) is formed with a first welding hole 212 corresponding to the flow passage part 11, and the end face of the second end of the welding block 21 (away from the limiting part 12) is formed with a second welding hole 213. The first welding hole 212 communicates with the first welding hole 213. The flow passage 11 of the electrode post 1 is inserted into the first welding hole 212 and welded to the welding block 21 (i.e., the outer side wall of the flow passage 11 is welded to the inner side wall of the first welding hole 212). Further, a gap is formed between the end face of the flow passage 11 away from the limiting part 12 and the second end of the first welding hole 212 (away from the limiting part 12). The height of the gap is not less than 0.15mm (i.e., H≥0.15mm). This can prevent the solder mark from protruding, so as to ensure the welding quality of the electrode post 1 and the welding block 21.

[0042] Furthermore, in this embodiment, the tabs 31 of the electrode assembly can pass sequentially through the second welding hole 213 and the first welding hole 212 to be welded and fixed to the end face of the current-carrying part 11 (away from the limiting part 12). To ensure smooth connection between the tabs 31 and the current-carrying part 11, in the longitudinal section of the welding block 21, the length of the second welding hole 213 is greater than the length of the first welding hole 212 (i.e., L1 > L2). It should be noted that the specifications of the current-carrying part 11, such as its cross-sectional area, are not specifically limited and should be determined comprehensively based on the actual situation, such as the current-carrying capacity required by the battery cell, as long as it can meet the usage requirements of the battery cell.

[0043] Furthermore, as shown in Figures 2 and 3, a first recess 211 is also formed around the outer side of the welding block 21, and the first recess 211 extends along a first direction to the end face of the first end of the welding block 21.

[0044] It should be further explained that both the aforementioned electrode post 1 and welding block 21 can be formed by one stamping without secondary processing, effectively reducing the manufacturing cost of the battery cell. In addition, the electrode post 1 shown in Figures 2 to 5 is the negative electrode post, which is made of copper-aluminum composite material. That is, the end of the current-passing part 11 away from the limiting part 12 of the negative electrode post is made of copper, and the rest is made of aluminum. The electrode post 1 shown in Figure 6 is the positive electrode post, which is made of a single material.

[0045] In this embodiment, the sealing ring 22 is fitted onto the outer side of the flow passage 11. As shown in Figures 2 and 3, along the first direction, the second end of the sealing ring 22 (away from the limiting part 12) abuts against the first end of the welding block 21 (the two are specifically formed to abut their end faces). In addition, a second recess 221 is formed around the outer side of the sealing ring 22, and the second recess 221 extends along the first direction to the end face of the first end of the sealing ring 22.

[0046] As shown in Figures 2 and 3, a lower plastic 23 is also fitted around the outer side of the sealing ring 22 and the welding block 21. The lower plastic 23 is correspondingly connected to the first recess 211 of the welding block 21, and part of the structure of the lower plastic 23 abuts against the end face of the first end of the welding block 21. Furthermore, in this embodiment, the cover plate body 24 is correspondingly fitted onto the second recess 221 of the sealing ring 22, and the cover plate body 24 can abut against the end face of the first end of the lower plastic 23. Further, a third recess 231 is formed around the outer side of the lower plastic 23, extending along a first direction to the end face of the first end of the lower plastic 23. The cover plate body 24 forms a stepped structure 241 correspondingly connected to the third recess 231, thus improving the stability of the cover plate assembly after assembly. In other words, in this embodiment, the lower plastic 23 is disposed within the space enclosed by the cover plate body 24, the sealing ring 22, the welding block 21, and the battery cell housing.

[0047] In this embodiment, as shown in Figures 2 and 3, the upper plastic 25 is sleeved on the outer side of the pole post 1. Along the first direction, a first mounting hole 251 is formed on the end face of the first end of the upper plastic 25, and the first mounting hole 251 corresponds to and is adapted to the limiting part 12; a second mounting hole 252 is formed on the end face of the second end of the upper plastic 25, and the second mounting hole 252 corresponds to and is adapted to the flow passage part 11; the first mounting hole 251 and the second mounting hole 252 are connected. When the upper plastic 25 is connected to the pole post 1, the end face of the second end of the limiting part 12 abuts against the bottom surface of the first mounting hole 251, so that the end face of the second end of the upper plastic 25 abuts against the first end of the cover plate body 24 and the sealing ring 22. This achieves stable assembly between the various components in the cover plate assembly and stable assembly between the cover plate assembly and the pole post 1.

[0048] It should be noted that the specifications of the limiting part 12 of the pole 1, such as its cross-sectional area, are not specifically limited, and should be determined comprehensively based on the actual situation, such as the overcurrent requirements of the bus (not shown in the figure).

[0049] According to the present invention, the electrode post 1 of the battery cell is set as an elongated cylindrical structure, that is, the cross-section of any part of the electrode post 1 is formed as an elongated circle. In this way (compared to the existing cylindrical electrode post 1), the cross-sectional area of ​​the electrode post 1 is effectively increased, thereby effectively improving the current carrying capacity of the electrode post 1 to meet the usage requirements of the battery cell. In addition, the electrode post 1 of the battery cell in the present invention is welded and fixed to the welding block 21. The longitudinal section of the electrode post 1 is set as a T-shaped structure. Then, through structural cooperation, the other components in the cover plate assembly can be fixed between the electrode post 1 and the welding block 21. The electrode tab 31 of the electrode group can also pass through the welding block 21 and be welded to the electrode post 1. This connection method (compared to the existing connection by riveting block) can effectively avoid the damage to the battery cell performance caused by riveting vibration.

[0050] According to a second aspect of the present invention, a battery cell module is provided, the battery cell module comprising the battery cells described above.

[0051] According to a third aspect of the present invention, a battery pack is provided, the battery pack being provided with the cell module as described above.

[0052] 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, or make equivalent substitutions for some of the technical features, within the technical scope disclosed in this application. 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. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A battery cell, characterized in that, The battery cell includes: a terminal post having a limiting portion and a current-passing portion sequentially connected along a first direction, both the limiting portion and the current-passing portion having elliptical cross-sections, and the area of ​​the limiting portion's cross-section being larger than the area of ​​the current-passing portion's cross-section, such that the longitudinal section of the terminal post has a T-shaped structure; a cover plate assembly fitted onto the outer side of the terminal post; the cover plate assembly including a welding block having a first welding hole corresponding to the current-passing portion, the current-passing portion being inserted into the first welding hole and welded to the welding block; along the first direction, a gap is formed between the end face of the current-passing portion away from the limiting portion and the second end of the first welding hole away from the limiting portion, the height of the gap being not less than 0.15 mm; and an electrode assembly having tabs, the tabs being welded to the current-passing portion.

2. The battery cell according to claim 1, characterized in that, The welding block has a second welding hole that communicates with the first welding hole. After the electrode passes through the second welding hole and the first welding hole, it is welded to the flow passage.

3. The battery cell according to claim 2, characterized in that, Along the first direction, the first welding hole penetrates the first end of the welding block near the limiting portion, and the second welding hole penetrates the second end of the welding block away from the limiting portion.

4. The battery cell according to claim 3, characterized in that, A first recess is formed around the outer side of the welding block, and the first recess extends along the first direction to the end face of the first end of the welding block.

5. The battery cell according to claim 4, characterized in that, The cover plate assembly includes a sealing ring correspondingly sleeved on the outer side of the flow passage; along the first direction, the second end of the sealing ring away from the limiting portion abuts against the first end of the welding block; a second recess is formed around the outer side of the sealing ring, and the second recess extends along the first direction to the end face of the first end of the sealing ring.

6. The battery cell according to claim 5, characterized in that, The cover plate assembly includes a cover plate body, which is pressed onto the second recess of the sealing ring.

7. The battery cell according to claim 6, characterized in that, A lower plastic is provided within the space enclosed by the cover plate body, the sealing ring, and the welding block; a third recess is formed around the outer side of the lower plastic, the third recess extends along the first direction to the end face of the first end of the lower plastic, and the cover plate body forms a stepped structure corresponding to and connected to the third recess.

8. The battery cell according to claim 7, characterized in that, The cover plate assembly further includes an upper plastic. Along the first direction, a first mounting hole is formed on the end face of the first end of the upper plastic, and the first mounting hole is adapted to the limiting part. A second mounting hole is formed on the end face of the second end of the upper plastic, and the second mounting hole is adapted to the flow passage part. The first mounting hole and the second mounting hole are connected. When the upper plastic is connected to the pole, the end face of the second end of the upper plastic abuts against the cover plate body and the first end of the sealing ring.

9. A battery cell module, characterized in that, The battery cell module includes the battery cell as described in any one of claims 1 to 8.

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

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