Battery cell

Abstract

Provided is a battery cell. The battery cell comprises a top cover assembly (1), cell packages (2) and pins (3); two cell packages (2) are arranged in a first direction, and tabs (21) are respectively provided at two ends of each cell package (2) in a second direction; each pin (3) comprises a first connecting part (31) and a second connecting part (32); the first connecting part (31) is connected to the top cover assembly (1); the second connecting part (32) comprises two soldering plates (322) spaced apart from each other and perpendicular to the first direction; the tabs (21) located at the same ends of the two cell packages (2) are respectively attached to the opposite sides of the two soldering plates (322); and the distance between the opposite surfaces of the two soldering plates (322) in the first direction is d.

Description

A battery cell

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on June 16, 2023, with application number 202321545816.3. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a battery cell. Background Art

[0003] In a battery cell, pins are usually used to connect the tabs of the core pack to the top cover or pole of the battery cell, so that the current of the core pack can be extracted. In the related art, some battery cells include two core packs, and only one welding position is set on the pins. The tabs of the two core packs are welded at this welding position. On the one hand, the sum of the thickness of the tabs of the two core packs is large, and the welding parameters are difficult to control, which makes welding more difficult. On the other hand, in order to ensure that the tabs of the two core packs can be led out to the welding position, the tab lengths of the two core packs need to be different, that is, two different core packs need to be produced. SUMMARY OF THE INVENTION

[0004] When assembling the battery cells, it is necessary to distinguish between the two core packs, which leads to low production efficiency of the battery cells. Therefore, a battery cell is urgently needed to solve this technical problem.

[0005] The present application provides a battery cell, the pins of which can be easily connected to the tabs of two core packs, and there is no need to distinguish between different core packs during assembly, thereby reducing the production difficulty of the battery cell and improving the production efficiency of the battery cell.

[0006] This application adopts the following technical solutions:

[0007] A battery cell, comprising:

[0008] Top cover assembly;

[0009] Two core packages are arranged side by side along a first direction, and pole tabs are respectively provided at both ends of the core packages along a second direction;

[0010] The pin includes a first connecting portion and a second connecting portion, wherein the first connecting portion is connected to the top cover assembly, and the second connecting portion includes a connecting plate and two welding plates respectively connected to the connecting plate. The second connecting portion has a first state. In the first state, the two welding plates are spaced apart and are both perpendicular to the first direction. The two tabs at the same end of the two core packs are respectively attached to the sides of the two welding plates facing away from each other. The distance between the surfaces of the two welding plates facing away from each other along the first direction is d, and d satisfies the formula:

[0011] ;

[0012] Wherein, T is the thickness of the two core packages along the first direction, and b is the thickness of the tab along the first direction. Beneficial effects

[0013] In the battery cell of the present application, the first connecting portion of the pin is connected to the top cover assembly, and the second connecting portion is formed with two welding plates. In the first state of the second connecting portion, the pole ears of the two core packs located at the same end are respectively fitted and connected with the two welding plates, that is, two independent welding positions are formed on the pin, and the pole ears of the two core packs can be welded separately, which reduces the difficulty of welding; by limiting the distance d between the surfaces of the two welding plates facing away from each other along the first direction, it is ensured that when the two core packs respectively have pole ears at the center along the first direction, the pole ears of the two core packs just correspond to and dock with the two welding plates of the pin, that is, the two core packs of the same battery cell can smoothly dock with the two welding plates of the pin when using exactly the same structure, thereby reducing the production difficulty of the battery cell and improving the production efficiency of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG1 is a schematic structural diagram of a battery cell provided in a specific embodiment of the present application;

[0015] FIG2 is an exploded view of a battery cell provided in a specific embodiment of the present application;

[0016] FIG3 is a schematic diagram of a battery cell provided in a specific embodiment of the present application when the second connection portion of the pin is in a first state;

[0017] FIG4 is a side view of a core package and pins provided in a specific embodiment of the present application;

[0018] FIG5 is a schematic diagram of a battery cell provided in a specific embodiment of the present application, wherein the second connection portion of the pin is in a second state;

[0019] FIG6 is a top view of the core package and pins provided in a specific embodiment of the present application.

[0020] In the picture:

[0021] 1. Top cover assembly; 11. Cover plate body; 12. Pole; 13. Insulator; 14. Press block;

[0022] 2. Core package; 21. Tab;

[0023] 3. Pin; 31. First connection portion; 311. Mounting hole; 32. Second connection portion; 321. Connecting plate; 322. Welding plate; 323. Crease; 324. Process through hole;

[0024] 4. Shell. Modes for Carrying Out the Invention

[0025] In the description of this application, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and can refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0026] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meanings.

[0027] This embodiment provides a battery cell, as shown in Figures 1 and 2, the battery cell includes a top cover assembly 1, an outer shell 4, two core packs 2 and two pins 3. The outer shell 4 forms a box structure with an opening on one side, and the two core packs 2 are arranged in the outer shell 4. The two pins 3 are used to realize the electrical connection between the core packs 2 and the top cover assembly 1. The top cover assembly 1 can be sealed at the opening of the outer shell 4, so that the battery cell forms a closed state. Normally, a layer of insulating film is provided on the inner wall of the outer shell 4. As shown in Figure 2, the top cover assembly 1 includes a cover body 11 and two poles 12, the two poles 12 are respectively positive and negative poles, and the two pins 3 are respectively connected to the two poles 12, so as to lead out the current of the core pack 2. The top cover assembly 1 also includes an insulating part 13, which covers the inner and outer sides of the cover body 11. It can be understood that the top cover assembly 1 also includes a liquid injection structure, an explosion-proof structure, etc.

[0028] As shown in Figures 2 and 3, the two core packages 2 are arranged side by side along a first direction (i.e., the X direction in Figure 2), and each core package 2 includes two pole ears 21. The two pole ears 21 of the core package 2 extend from the two ends of the core package 2 along the second direction (i.e., the Y direction in Figure 2). It can be understood that the two pole ears 21 of the core package 2 are respectively a positive pole ear and a negative pole ear. In this embodiment, the positive pole ears of the two core packages 2 are located at the same end, and the negative pole ears of the two core packages 2 are located at the same end. The two positive pole ears are connected to the positive pole column through a pin 3, and the two negative pole ears are connected to the negative pole column through another pin 3. In this embodiment, as shown in Figure 2, in the initial state of the core package 2 (i.e., before the core package 2 is connected to the pin 3), the plane where the pole ear 21 is located is perpendicular to the first direction.

[0029] Among them, the first direction is parallel to the narrow side of the four side surfaces of the battery cell, specifically, the first direction is perpendicular to the wide side of the four side surfaces of the battery cell; the second direction is parallel to the wide side of the four side surfaces of the battery cell, specifically, the second direction is perpendicular to the narrow side of the four side surfaces of the battery cell.

[0030] As shown in Figures 2 and 3, the pin 3 includes a first connection portion 31 and a second connection portion 32, wherein the first connection portion 31 is connected to the pole 12 of the top cover assembly 1, and the second connection portion 32 is used to connect to the two tabs 21 located at the same end of the two core packs 2. In this embodiment, as shown in Figure 2, the top cover assembly 1 also includes two pressing blocks 14, a fastener, and the two pressing blocks 14 are respectively arranged corresponding to the two first connection portions 31. Each pressing block 14 and the corresponding first connection portion 31 are respectively arranged on both sides of the cover body 11. The first connection portion 31 is provided with a mounting hole 311. One end of the pole 12 is riveted or welded to the mounting hole 311, and the other end of the pole 12 passes through the cover body 11 and is riveted or welded to the corresponding pressing block 14.

[0031] As shown in Figures 2 and 3, the second connecting portion 32 includes a connecting plate 321 and two welding plates 322. The connecting plate 321 is connected to the first connecting portion 31, and the two welding plates 322 are respectively connected to the connecting plate 321. The second connecting portion 32 has a first state. In the first state, the two welding plates 322 are parallel and spaced apart, and the plane on which the welding plates 322 are located is perpendicular to the first direction. The two tabs 21 at the same end of the two core packs 2 are respectively connected to the sides of the two welding plates 322 facing away from each other. As shown in Figure 4, the distance along the first direction between the surfaces of the two welding plates 322 facing away from each other is d, and d satisfies the formula:

[0032] Formula (1).

[0033] Wherein, T is the thickness of the two core packs 2 along the first direction, and b is the thickness of the tab 21 along the first direction. In some embodiments, the tab 21 is formed by stacking multiple layers of material. In this case, the thickness of the tab 21 along the first direction is b=mh, where m is the number of layers of material and h is the thickness of each layer of material.

[0034] In the battery cell of this embodiment, in the first state of the pin 3, the pole ear 21 is arranged in parallel with the welding plate 322, and the pole ears 21 of the two core packs 2 located at the same end are respectively fitted and connected with the two welding plates 322, that is, two independent welding positions are formed on the pin 3, and the pole ears 21 of the two core packs 2 can be welded separately, which reduces the difficulty of welding; by limiting the distance d between the surfaces of the two welding plates 322 facing away from each other along the first direction, it is ensured that when the two core packs 2 respectively have pole ears 21 at the center along the first direction, the pole ears 21 of the two core packs 2 just correspond to the two welding welds of the pin 3, that is, the two core packs 2 of the same battery cell can smoothly achieve docking with the two welding plates 322 of the pin 3 when using exactly the same structure, thereby reducing the production difficulty of the battery cell and improving the production efficiency of the battery cell.

[0035] In this embodiment, as shown in FIG3 , the tab 21 is welded to the corresponding welding plate 322 when the second connecting portion 32 is in the first state (i.e., the state shown in FIG3 ). In this state, the tab 21 and the corresponding welding plate 322 are stably attached to facilitate welding operations.

[0036] Specifically, as shown in FIG4 , when , the inner surface of the tab 21 (i.e., the surface of one tab 21 facing the other tab 21) just fits against the outer surface of the corresponding welding plate 322 (i.e., the surface of one welding plate 322 facing away from the other welding plate 322). The 5 mm in formula (1) indicates that the welding plate 322 can deviate within a certain range toward the tab 21 on the corresponding side. At this time, a certain amount of squeezing force is generated between the welding plate 322 and the corresponding tab 21, thereby making the welding plate 322 and the tab 21 fit more tightly, not only improving the convenience of welding the two, but also improving the reliability of the connection between the two.

[0037] In some embodiments, if the tab 21 connected to the welding plate 322 is a negative tab, the distance d along the first direction between the surfaces of the two welding plates 322 facing away from each other satisfies:

[0038] Formula (2).

[0039] Typically, the negative electrode tab is made of copper, which has a relatively low hardness. In this embodiment, the margin in formula (2) is set to 3 mm for the negative electrode tab. This can prevent the welding plate 322 from being excessively offset, which could cause significant deformation of the corresponding negative electrode tab and thus prevent the negative electrode tab from being torn.

[0040] In some embodiments, if the tab 21 connected to the welding plate 322 is a positive tab, the distance d along the first direction between the surfaces of the two welding plates 322 facing away from each other satisfies:

[0041] Formula (3).

[0042] By setting the distance d within this range, it is possible to ensure that the positive electrode tab is accurately attached to the corresponding welding plate 322 and maintain a certain pressing force, while preventing the positive electrode tab from being excessively deformed and torn.

[0043] In some embodiments, if the tab 21 connected to the welding plate 322 is a negative tab, the distance d along the first direction between the surfaces of the two welding plates 322 facing away from each other satisfies:

[0044] Formula (4).

[0045] By setting the distance d within this range, it is possible to ensure that the negative electrode tab is accurately attached to the corresponding welding plate 322 and maintain a certain pressing force, while preventing the negative electrode tab from being excessively deformed and torn.

[0046] As shown in Figure 5, the second connection portion 32 of the lead 3 also has a second state. In this second state, the two welding plates 322 and the connecting plate 321 are arranged coplanarly and perpendicular to the second direction. This arrangement makes the structure formed by the lead 3 and the core package 2 compact. When installed in the housing 4, the entire battery cell is smaller, thereby increasing the energy density of the battery cell. Optionally, the second connection portion 32 can be switched from the first state to the second state by bending the welding plates 322 and the corresponding tabs 21.

[0047] In this embodiment, the connecting plate 321 and the two welding plates 322 are integrally formed from a single plate. Before the pin 3 is connected to the tab 21, the pin 3 is bent to a first position. After the second connecting portion 32 is welded to the corresponding tab 21, the welding plates 322 are bent to a second position.

[0048] As shown in Figure 5, a fold 323 is provided between the welding plate 322 and the connecting plate 321, so that the bending of the welding plate 322 relative to the connecting plate 321 is easier. In some embodiments, a process through hole 324 is provided at the fold 323, and the convenience of bending the welding plate 322 can be further improved by providing the process through hole 324. Optionally, the process through hole 324 is a long strip hole, and the process through hole 324 extends along the length direction of the fold 323. Normally, the pin 3 connected to the negative electrode ear is made of copper material, which has a relatively soft hardness, and the corresponding pin 3 can choose not to have a process through hole 324. The pin 3 connected to the positive electrode ear is made of aluminum material, which has a relatively hard hardness, and the corresponding pin 3 can choose to have a process through hole 324.

[0049] As shown in FIG5 , in the second state, the dimension of the second connecting portion 32 along the first direction is less than or equal to the thickness T of the two core packages 2 in the first direction. Therefore, when the core package 2 and the leads 3 are installed in the housing 4, the welding plate 322 will not scratch the insulating film inside the housing 4, thereby improving the safety of the battery cell.

[0050] In order to ensure that the dimension of the second connection portion 32 along the first direction is less than or equal to T after the pin 3 is switched to the second state, as shown in FIG6 , in the first state, the width of the welding plate 322 in the second direction is a, and a satisfies the formula:

[0051] d-2R+πR+2a<T formula (5).

[0052] Wherein, R is the radius of the inner fillet formed between the welding plate 322 and the connecting plate 321. By making the pin 3 satisfy formula (5) in the first state, after the second connecting portion 32 of the pin 3 is switched to the second state, the size of the second connecting portion 32 along the first direction is smaller than T.

Claims

1. A battery cell, comprising: Top cover assembly (1); Two core packages (2) are arranged side by side along a first direction, and pole ears (21) are respectively provided at two ends of the core package (2) along a second direction; The pin (3) comprises a first connecting portion (31) and a second connecting portion (32), wherein the first connecting portion (31) is connected to the top cover assembly (1), and the second connecting portion (32) comprises a connecting plate (321) and two welding plates (322) respectively connected to the connecting plate (321), and the second connecting portion (322) has a first state. In the first state, the two welding plates (322) are arranged at intervals and are both perpendicular to the first direction, and the two pole ears (21) located at the same end of the two core packages (2) are respectively connected to the sides of the two welding plates (322) facing away from each other, and the distance between the surfaces of the two welding plates (322) facing away from each other along the first direction is d, and d satisfies the formula: ； Wherein, T is the thickness of the two core packages (2) along the first direction, and b is the thickness of the tab (21) along the first direction.

2. The battery cell according to claim 1, wherein: The pole lug (21) is welded to the corresponding welding plate (322) when the second connecting portion (32) is in the first state.

3. The battery cell according to claim 1, wherein: If the electrode tab (21) connected to the welding plate (322) is a negative electrode tab, the distance d along the first direction between the surfaces of the two welding plates (322) facing away from each other satisfies: 。 4. The battery cell according to claim 1, wherein: If the electrode tab (21) connected to the welding plate (322) is a positive electrode tab, the distance d between the surfaces of the two welding plates (322) facing away from each other along the first direction satisfies: ； And / or, if the electrode tab (21) connected to the welding plate (322) is a negative electrode tab, the distance d along the first direction between the surfaces of the two welding plates (322) facing away from each other satisfies: 。 5. The battery cell according to any one of claims 1 to 4, wherein: The second connecting portion (32) has a second state. In the second state, the two welding plates (322) are coplanar with the connecting plate (321) and are perpendicular to the second direction.

6. The battery cell according to claim 5, wherein: In the second state, the dimension of the second connecting portion (32) along the first direction is less than or equal to the thickness T of the two core packages (2) in the first direction.

7. The battery cell according to claim 5 or 6, wherein: In the first state, the width of the welding plate (322) in the second direction is a, and a satisfies the formula: d-2R+πR+2a<T; Wherein, R is the radius of the inner fillet formed between the welding plate (322) and the connecting plate (321).

8. The battery cell according to any one of claims 5 to 7, wherein: The two welding plates (322) and the connecting plate (321) are integrally formed, and a fold (323) is provided between the welding plates (322) and the connecting plate (321).

9. The battery cell according to claim 8, wherein: A process through hole (324) is provided at the fold (323).

10. The battery cell according to any one of claims 1 to 9, wherein: The top cover assembly (1) comprises a cover plate body (11) and a pole (12); the pole (12) is inserted through the cover plate body (11) and connected to the first connecting portion (31).

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