Battery tab structure

Abstract

The utility model discloses a battery tab structure which comprises a pole piece, a dressing area is arranged on the pole piece, a tab connecting area arranged along the length direction of the pole piece is arranged on one side of the dressing area, a tab area is arranged on one side, far away from the dressing area, of the tab connecting area, and the tab area comprises a plurality of peak-shaped tabs which are sequentially connected along the length direction of the pole piece. A tab head blank area is spaced between the head end of the tab area and the head end of the pole piece, and a tab tail blank area is spaced between the tail end of the tab area and the tail end of the pole piece. The battery tab structure provided by the utility model has the beneficial effects that the flat tab is cut into the peak-shaped tab, and the tab head blank area and the tab tail blank area are arranged at the two ends of the pole piece, so that the overlapping thickness of the two ends of a flattened battery cell is reduced, and the overall volume and weight of the battery are reduced; the problem of gas expansion possibly generated when the battery is subjected to thermal runaway is effectively solved, and the risk caused by overheating of the battery is reduced, so that the safety of the battery is improved.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a battery tab structure. Background Technology

[0002] With the widespread application of lithium batteries, large cylindrical lithium batteries are developing rapidly due to their advantages such as high energy density, good fast charging performance, and long cycle life. Currently, traditional large cylindrical lithium batteries often use a straight-shaped tab design. The main manufacturing process for full tabs involves flattening both ends of the prepared core, then welding the current plate and sealing sheet, and finally injecting electrolyte and forming the finished battery. However, this straight-shaped tab design results in multiple layers of foil being stacked together during the flattening process, leading to a large overlap thickness at both ends of the cell. This not only increases the overall size and weight of the battery but may also affect its safety performance. Utility Model Content

[0003] The purpose of this utility model is to overcome the shortcomings of the prior art and provide a battery tab structure. By cutting the flat tab into a mountain-shaped tab and setting blank areas at the head and tail of the tab at both ends of the tab, the overlap thickness at both ends of the cell after flattening is reduced, the overall volume and weight of the battery are reduced, the gas expansion problem that may occur when the battery experiences thermal runaway is effectively mitigated, the risk caused by overheating of the battery is reduced, and the safety of the battery is improved.

[0004] The purpose of this utility model is achieved through the following technical measures: a battery tab structure, including an electrode sheet, wherein the electrode sheet is provided with a coating area, a tab connection area is provided on one side of the coating area along the length direction of the electrode sheet, and a tab area is provided on the side of the tab connection area away from the coating area. The tab area includes a plurality of mountain-shaped tabs connected sequentially along the length direction of the electrode sheet. A tab head blank area is separated between the first end of the tab area and the first end of the electrode sheet, and a tab tail blank area is separated between the last end of the tab area and the last end of the electrode sheet.

[0005] In some embodiments, the peak height of the mountain-shaped electrode is 5-10 mm, and the width between the highest points of two adjacent mountain-shaped electrodes is 15-60 mm.

[0006] In some embodiments, the height of the tab connection area is 1-8 mm.

[0007] In some embodiments, the length of the blank area at the tip of the electrode is 200-500mm.

[0008] In some embodiments, the length of the blank area at the tail of the electrode ear is 300-500 mm.

[0009] In some embodiments, the auxiliary material area, the tab connection area, and the tab area on the electrode sheet are integrally formed.

[0010] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model cuts the flat electrode tabs into mountain-shaped electrode tabs and sets blank areas at the head and tail of the electrode tabs at both ends of the electrode sheet, thereby reducing the overlap thickness at both ends of the cell after flattening, reducing the overall volume and weight of the battery, effectively mitigating the gas expansion problem that may occur when the battery experiences thermal runaway, reducing the risk caused by overheating of the battery, and thus improving the safety of the battery.

[0011] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of this utility model.

[0013] Among them, 1. Dressing area, 2. Electrode connection area, 3. Peak-shaped electrode, 4. Blank area at the head of electrode, 5. Blank area at the tail of electrode. Detailed Implementation

[0014] like Figure 1 As shown, a battery tab structure includes an electrode sheet with a coating area 1 for coating positive / negative active materials. A tab connection area 2, arranged along the length of the electrode sheet, is located on one side of the coating area 1. A tab area is located on the side of the tab connection area 2 away from the coating area 1. Each tab area includes multiple peak-shaped tabs 3 connected sequentially along the length of the electrode sheet. Preferably, the bottoms of two adjacent peak-shaped tabs 3 are connected to each other. Further, the peak-shaped tabs 3 are preferably triangular. A tab head blank area 4 is separated from the beginning of the tab area by the beginning of the electrode sheet, and a tab tail blank area 5 is separated from the end of the tab area by the end of the electrode sheet. Specifically, along the length of the electrode sheet, the straight-line distance between the starting point of the tab area and the starting point of the electrode sheet is the length of the tab head blank area 4, and the straight-line distance between the ending point of the tab area and the ending point of the electrode sheet is the length of the tab tail blank area 5.

[0015] Further preferred, the mountain-shaped electrode 3 has a left-right symmetrical structure.

[0016] In some embodiments, the height of the peak-shaped electrode 3 is 5-10 mm, and the width between the highest points of two adjacent peak-shaped electrode 3 is 15-60 mm.

[0017] In some embodiments, the height of the tab connection area 2 is 1-8 mm.

[0018] In some embodiments, the length of the blank area 4 at the tip of the electrode is 200-500mm.

[0019] In some embodiments, the length of the blank area 5 at the tail of the electrode ear is 300-500mm.

[0020] In some embodiments, the auxiliary material area 1, the electrode tab connection area 2, and the electrode tab area on the electrode sheet are integrally formed.

[0021] Example 1

[0022] The coated and rolled positive electrode sheet is cut from one edge towards the center. First, the blank area 4 at the head of the tab is cut out. Then, the tab 3 in the shape of a mountain peak is cut out. Finally, the blank area 5 at the tail of the tab is cut out. After cutting, the following is obtained: Figure 1 In one specific embodiment shown, the electrode connecting area 2 is 5.5mm, the bottoms of two adjacent peak-shaped electrodes 3 are connected to each other, the height of the peak is 5mm, the width between the highest points of two adjacent peak-shaped electrodes 3 is 15mm, the length of the blank area 4 at the head of the electrode is 470mm, and the length of the blank area 5 at the tail of the electrode is 360mm.

[0023] The negative electrode sheet is prepared and cut using the same method. The positive electrode sheet, separator, and negative electrode sheet are stacked and wound to form a core. The two ends of the core are then flattened to form a flattened area. The flattened cell is then assembled into a complete battery according to the battery manufacturing process.

[0024] Example 2

[0025] The same method as in Example 1 was used to obtain a complete battery, except that the width between the highest points of two adjacent mountain-shaped tabs 3 in Example 2 was 20 mm.

[0026] Example 3

[0027] The complete battery was obtained using the same method as in Example 1, except that the width between the highest points of two adjacent mountain-shaped tabs 3 in Example 3 was 25 mm.

[0028] Example 4

[0029] The same method as in Example 1 was used to obtain a complete battery, except that in Example 4, the width between the highest points of two adjacent mountain-shaped tabs 3 was 20mm, and the thickness at both ends of the cell was controlled to be 0.8mm after winding and flattening.

[0030] Example 5

[0031] The same method as in Example 1 was used to obtain a complete battery, except that in Example 5, the width between the highest points of two adjacent mountain-shaped tabs 3 was 25mm, and the thickness at both ends of the cell was controlled to be 0.8mm after winding and flattening.

[0032] Comparative Example 1

[0033] The complete battery was obtained using the same method as in Example 1, except that the tabs in Comparative Example 1 were cut into a normal flat full tab shape with a tab height of 5 mm.

[0034] Comparative Example 2

[0035] The same method as in Example 1 was used to complete the battery, except that: in Comparative Example 2, the tabs were cut into a normal flat full tab shape, the tab height was 5mm, and the thickness at both ends of the cell was controlled to be 0.8mm after winding and flattening.

[0036] Comparative Example 3

[0037] The same method as in Example 1 was used to obtain a complete battery, except that: in Comparative Example 3, the tabs were not provided with blank areas 4 at the head of the tabs and blank areas 5 at the tail of the tabs, and the thickness of both ends of the cell was controlled to be 0.8 mm after winding and flattening.

[0038] The thickness at both ends and the capacity of the complete batteries in Examples 1-3 and Comparative Example 1 were measured. The test results are shown in Table 1 below:

[0039] Table 1. Test results of battery thickness at both ends and battery capacity.

[0040]

[0041] The complete batteries in Examples 1, 4, 5 and Comparative Example 2 were tested for their pressure relief capacity at both ends and the duration of electrolyte immersion. The test results are shown in Table 2 below:

[0042] Table 2. Test results of battery pressure relief capacity and electrolyte wetting time.

[0043]

[0044] The complete batteries in Example 1 and Comparative Example 3 were tested for their pressure relief capacity at both ends and the duration of electrolyte immersion. The test results are shown in Table 3 below:

[0045] Table 3. Test results of battery pressure relief capacity and electrolyte wetting time.

[0046]

[0047] As shown in Table 1, the tab structure of this application can reduce the thickness at both ends of the battery cell, thereby increasing the battery capacity. As shown in Table 2, the tab structure of this application can significantly reduce both the pressure relief and the electrolyte immersion time. This indicates that the tab structure of this application can effectively reduce the pressure caused by thermal expansion of the battery and shorten the electrolyte immersion time, reducing the risk of overheating and thus improving battery safety. As shown in Table 3, the blank areas 4 at the head of the tab and 5 at the tail of the tab can also significantly reduce the pressure caused by thermal expansion of the battery and shorten the electrolyte immersion time, and also make the end face of the coiled core more aesthetically pleasing.

[0048] It should be noted that those skilled in the art can use their well-known electrode coating and rolling methods to obtain coated and rolled electrodes, those skilled in the art can use their well-known battery manufacturing processes to obtain complete batteries, and those skilled in the art can use their well-known methods to test the thickness at both ends of the battery and the battery capacity, the pressure relief capacity at both ends of the battery, and the length of electrolyte wetting time.

[0049] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0050] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0051] In this utility model, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0052] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A battery tab structure, characterized in that: The device includes an electrode sheet, which has a dressing area. On one side of the dressing area, there is an electrode tab connection area arranged along the length of the electrode sheet. On the side of the electrode tab connection area away from the dressing area, there is an electrode tab area. The electrode tab area includes multiple mountain-shaped electrodes connected sequentially along the length of the electrode sheet. A blank area for the head of the electrode tab is separated from the head of the electrode tab area, and a blank area for the tail of the electrode tab is separated from the tail of the electrode sheet.

2. The battery tab structure according to claim 1, characterized in that: The height of the peak-shaped electrode ear is 5-10mm, and the width between the highest points of two adjacent peak-shaped electrode ears is 15-60mm.

3. The battery tab structure according to claim 1, characterized in that: The height of the tab connection area is 1-8mm.

4. The battery tab structure according to claim 1, characterized in that: The length of the blank area at the head of the electrode is 200-500mm.

5. The battery tab structure according to claim 1, characterized in that: The length of the blank area at the tail of the electrode ear is 300-500mm.

6. The battery tab structure according to claim 1, characterized in that: The auxiliary material area, electrode connection area, and electrode area on the electrode sheet are integrally formed.

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