Battery

Abstract

The utility model provides a battery which comprises a battery cell and an electric connecting piece, the battery cell comprises a battery cell body and tabs, the tabs are led out from the two ends of the battery cell body in the length direction, the polarities of the tabs at the two ends are different, the length of the battery cell body is A, the A is larger than or equal to 150 mm and smaller than or equal to 1500 mm, the width of the battery cell body is B, the B is larger than or equal to 50 mm and smaller than or equal to 280 mm, and the width of the battery cell body is A. The tab at at least one end is connected with the electric connecting piece with the same polarity through a plurality of welding parts which are sequentially arranged at intervals in the width direction of the battery cell body, and in the width direction of the battery cell body, the minimum distance between the welding part closest to the edge of the tab in the plurality of welding parts and the edge of the battery cell body is L, 0.05 < = L / B < = 0.60. The whole internal resistance of the battery is small.

Description

Technical Field

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

[0002] A typical battery on the market includes a cell body 011 and tabs 012. The tabs 012 extend from both ends of the cell body 011 along its length, and the polarities of the tabs 012 at the two ends are different. Previously, such as... Figure 1 As shown, each electrode tab is connected to the corresponding electrical connector only through a welding part 013. In this case, when the cell body is wide and long, the distance between the edge of the cell body in the width direction and the welding part is relatively large. This results in a longer current path from the welding part to the edge of the cell body in the width direction (i.e., X is longer in the figure), and a longer current path from one end of the cell body in the length direction to the other end in the length direction (i.e., Y is longer in the figure). Therefore, the overall current path through the edge of the cell body in the width direction is long (i.e., 2X+Y is longer), resulting in a larger overall internal resistance of the battery. This leads to more Joule heat generated in the battery when current flows through it, which is detrimental to the safe and stable operation of the battery. Moreover, the fast charging capability of the battery will also be limited as a result.

[0003] Therefore, for batteries with relatively large width and length, how to reduce their internal resistance is a technical problem that needs to be solved by those skilled in the art. Utility Model Content

[0004] To solve the above-mentioned technical problems, this application provides a battery, which includes a cell and an electrical connector. The cell includes a cell body and tabs. The tabs extend from both ends of the cell body along its length, and the tabs at both ends have different polarities. The length of the cell body is A, and the range of A is 150mm ≤ A ≤ 1500mm. The width of the cell body is B, and the range of B is 50mm ≤ B ≤ 280mm. At least one end of the tab is connected to the electrical connector of the same polarity through a plurality of welded portions arranged at intervals along the width direction of the cell body. In the width direction of the cell body, the minimum distance between the welded portion closest to the edge of the tab and the edge of the cell body is L, where 0.05 ≤ L / B ≤ 0.60.

[0005] The battery provided in this application has at least one end of its tab connected to a plurality of welded portions and an electrical connector of the same polarity arranged sequentially at intervals along the width direction of the cell body. This design, on the one hand, compared to each end of the tab being connected to only one welded portion and an electrical connector of the same polarity, shortens the distance between the welded portion and the edge of the cell body in the width direction while maintaining the same total area of ​​the welded portions. This shortens the current flow path from the welded portion to the edge of the cell body in the width direction (i.e.,...). Figure 2 The length of X is shorter than Figure 1 The length of X in the middle is increased, thus reducing the battery's internal resistance. On the other hand, it also allows the current paths corresponding to the multiple welded parts connected to the same polarity tabs to be connected in parallel. Therefore, the relationship between the overall internal resistance R of the battery and the internal resistances (R1, R2...Rn) of the current paths corresponding to these welded parts is: 1 / R1 + 1 / R2 + ... Rn = 1 / R. So the overall internal resistance R of the battery is less than any one of R1, R2...Rn, thus reducing the battery's internal resistance.

[0006] In the battery provided by this application, the minimum distance between the weld closest to the edge of the tab and the edge of the cell body in the width direction of the cell body is L. If L is too large, the distance between the weld closest to the edge of the tab and the edge of the cell body in the width direction will be too long, which will prevent the battery internal resistance from being reduced to a large extent. If L is too small, the weld closest to the edge of the tab will be too close to the battery casing and the insulation between the electrical connector and the casing, which will easily damage the insulation and casing when welding the tab and the electrical connector. By controlling the ratio of L to the width B of the cell body in the range of 0.05-0.60, it is possible to ensure a large reduction in the battery internal resistance and avoid damage to the casing and insulation when welding the tab and the electrical connector. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of a conventional battery.

[0008] Figure 2 This is a schematic diagram of one embodiment of the battery provided in this application.

[0009] Figure 2 The annotations in the accompanying drawings are explained as follows:

[0010] 100 Cell body, 200 Tabs, 300 Adapter, 400 Welding part, 500 Cover plate, 600 Housing. Detailed Implementation

[0011] This application provides a battery pack. To enable those skilled in the art to better understand the technical solution of this application, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments.

[0012] like Figure 2 As shown, the battery provided in this application includes a battery cell and electrical connectors. The battery cell is located within a receiving cavity formed by the housing 600 and the cover plate 500. The battery cell includes a battery cell body 100 and tabs 200. The tabs 200 extend from both ends of the battery cell body 100 along its length. The two ends of the tabs 200 have different polarities; one end of the tab 200 is the positive tab, and the other end of the tab 200 is the negative tab.

[0013] Specifically, the cell body 100 includes a positive electrode and a negative electrode, which are arranged alternately, with a separator between adjacent positive and negative electrode sheets. In some embodiments, the positive and negative electrode sheets are arranged alternately along the thickness direction of the cell body 100, making the cell body 100 a stacked structure. In some embodiments, the positive and negative electrode sheets are wound, and are arranged alternately along a direction perpendicular to the winding center line, making the cell body 100 a wound structure. The positive and negative electrode sheets have similar structures, both including a current collector and active material layers coated on both sides of the current collector. The uncoated portion of the current collector of the positive electrode sheet protrudes beyond the coated portion, forming a single positive electrode tab. Multiple layers of single positive electrode tabs are stacked to form a positive electrode tab. The uncoated portion of the current collector of the negative electrode sheet protrudes beyond the coated portion, forming a single negative electrode tab. Multiple negative electrode tabs are stacked one on top of another to form a negative electrode tab.

[0014] The length A of the battery cell body 100 is in the range of 150mm≤A≤1500mm. Specifically, the value of A can be 150mm, 200mm, 300mm, 400mm, 500mm, 600mm, 700mm, 800mm, 900mm, 1000mm, 1100mm, 1200mm, 1300mm, 1400mm, or 1500mm.

[0015] The width B of the battery cell body 100 is in the range of 50mm≤B≤280mm. Specifically, the value of B can be 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm, 200mm, 210mm, 220mm, 230mm, 240mm, 250mm, 260mm, 270mm, or 280mm.

[0016] At least one end of the tab 200 is connected to an electrical connector of the same polarity via a plurality of welded portions 400 arranged sequentially at intervals along the width direction of the cell body 100. Specifically, there may be two or more welded portions 400. In the width direction of the cell body 100, the minimum distance between the welded portion 400 closest to the edge of the tab 200 and the edge of the cell body 100 is L, where 0.05 ≤ L / B ≤ 0.60.

[0017] At least one end of the tab 200 is connected to a plurality of solder portions 400 arranged sequentially at intervals along the width direction of the cell body 100 and an electrical connector of the same polarity. This design, on the one hand, compared to each end of the tab 200 being connected to an electrical connector of the same polarity via only one solder portion 400, reduces the distance between the solder portion 400 and the edge of the cell body 100 in the width direction while maintaining the same total area of ​​the solder portions 400. This shortens the current flow path from the solder portion 400 to the edge of the cell body 100 in the width direction (i.e.,...). Figure 2 The length of X is shorter than Figure 1 The length of X in the middle is increased, thus reducing the battery's internal resistance. On the other hand, the current paths corresponding to the multiple welded parts 400 connected to the same polarity tab 200 are connected in parallel. Therefore, the relationship between the overall internal resistance R of the battery and the internal resistances (R1, R2...Rn) of the current paths corresponding to these welded parts 400 is: 1 / R1 + 1 / R2 + ... Rn = 1 / R. So the overall internal resistance R of the battery is less than any one of R1, R2...Rn, thus reducing the battery's internal resistance.

[0018] In the width direction of the cell body 100, the minimum distance between the weld 400 closest to the edge of the tab 200 and the edge of the cell body 100 is L. If L is too large, the distance between the weld 400 closest to the edge of the tab 200 and the edge of the cell body 100 in the width direction will be too long, which will prevent the battery internal resistance from being reduced to a large extent. If L is too small, the weld 400 closest to the edge of the tab 200 will be too close to the battery casing 600 and the insulation between the electrical connector and the casing 600, which will easily damage the insulation and casing 600 when welding the tab 200 and the electrical connector. By controlling the ratio of L to the width B of the cell body 100 to be in the range of 0.05-0.60, it is possible to ensure a large reduction in the battery internal resistance and avoid damage to the casing 600 and insulation when welding the tab 200 and the electrical connector.

[0019] In some embodiments, in the width direction of the cell body 100, the minimum spacing between adjacent welded portions 400 is M, where 0.20≤M / B≤0.80.

[0020] The end face of the tab 200 where the multiple welded parts 400 are located is referred to as the first end face. With the length and width of the first end face of the tab 200 remaining constant, the larger the spacing between adjacent welded parts 400 in the width direction of the cell body 100, the smaller the total area of ​​the multiple welded parts 400. Therefore, to ensure sufficient current-carrying area, the minimum spacing M between adjacent welded parts 400 cannot be too large. Conversely, if the minimum spacing M between adjacent welded parts 400 is too small, the area between adjacent welded parts 400 is prone to soldering through, which is detrimental to product yield. By controlling the ratio of the minimum spacing M between adjacent welded parts 400 to the width B of the cell body 100 within the range of 0.20-0.80, both sufficient current-carrying area and the resistance to soldering through the area between adjacent welded parts 400 can be ensured.

[0021] In some embodiments, in the width direction of the cell body 100, the minimum spacing between adjacent welded portions 400 is M, and the minimum spacing between the welded portion 400 closest to the edge of the electrode tab and the edge of the cell body 100 is L, where 0.1 ≤ L / M ≤ 0.7. For example, the ratio can specifically be 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, or 0.7.

[0022] If the ratio of the minimum distance L between the welded part 400 closest to the edge of the tab 200 and the edge of the cell body 100 and the minimum distance M between adjacent welded parts 400 is too large or too small (i.e., L / M is too large or too small), it means that L and M differ significantly. This will result in a significant difference between the internal resistance of the cell body 100 region corresponding to adjacent welded parts 400 and the internal resistance of the cell body 100 region corresponding to the outer side of the welded part 400 closest to the edge of the tab 200, leading to uneven overcurrent within the cell body 100 and hindering the reduction of the overall internal resistance of the battery. By controlling L / M within the range of 0.1-0.7, it can be ensured that the internal resistance of the cell body 100 region corresponding to adjacent welded parts 400 and the internal resistance of the cell body 100 region corresponding to the outer side of the welded part 400 closest to the edge of the tab 200 is not significantly different, thereby ensuring the balance of overcurrent within the cell body 100 and helping to reduce the overall internal resistance of the battery.

[0023] In some embodiments, the ratio of the total area of ​​the plurality of welded portions 400 to the area of ​​the first end face of the electrode tab 200 where the plurality of welded portions 400 are located is 0.05 to 0.40. For example, the ratio can be 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, or 0.40.

[0024] The larger the total area of ​​the plurality of welding portions 400, the greater the welding power required and the more welding heat generated when welding the tab 200 and the electrical connector, making it easier to damage the tab 200 and the insulator. Therefore, the total area of ​​the plurality of welding portions 400 cannot be too large. At the same time, the total area of ​​the plurality of welding portions 400 cannot be too small, otherwise the current-carrying area will be insufficient to meet the current-carrying requirements. By controlling the ratio of the total area of ​​the plurality of welding portions 400 to the area of ​​the first end face of the tab 200 where the plurality of welding portions 400 are located within the range of 0.05-0.4, damage to the tab 200 and the insulator can be avoided when welding the tab 200 and the electrical connector, while ensuring sufficient current-carrying area.

[0025] In some embodiments, the ratio of the area of ​​the smallest welded portion 400 to the area of ​​the largest welded portion 400 among the plurality of welded portions 400 ranges from 0.1 to 1. For example, the ratio can specifically be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1. When the ratio is 1, it means that each of the plurality of welded portions 400 has the same area. When the ratio is less than 1, it means that at least two of the plurality of welded portions 400 have different areas. If the ratio of the area of ​​the smallest weld portion 400 to the area of ​​the largest weld portion 400 is too small, it means that the areas of the smallest and largest weld portions 400 differ significantly. This will cause the smallest weld portion 400 to easily overheat and melt. When the smallest weld portion 400 overheats and melts, the current borne by the other weld portions 400 increases, thus also increasing the risk of overheating and melting. Therefore, the ratio of the area of ​​the smallest weld portion 400 to the area of ​​the largest weld portion 400 cannot be too small. By controlling the ratio of the area of ​​the smallest weld portion 400 to the area of ​​the largest weld portion 400 among the plurality of weld portions 400 to be within the range of 0.1-1, the risk of overheating and melting of each of the plurality of weld portions 400 can be reduced.

[0026] In some embodiments, the electrical connector includes a terminal post, with at least one end of the tab 200 electrically connected to the terminal post of the same polarity via the plurality of welded portions 400. The terminal post is disposed on a cover plate 500. In this case, the smaller the minimum distance L between the welded portion 400 closest to the edge of the tab 200 and the edge of the cell body 100, the larger the width of the terminal post in the width direction of the cell body 100 needs to be, and thus the greater the weight of the terminal post. Correspondingly, the hole in the cover plate 500 for the terminal post needs to be larger, and thus the lower the strength of the cover plate 500. Therefore, in this case, L needs to be appropriately increased to avoid excessive weight of the terminal post and excessively low strength of the cover plate 500. Therefore, the range of L / B can be further narrowed to: 0.20≤L / B≤0.60. For example, the value of L / B can specifically be 0.20, 0.30, 0.40, 0.50, or 0.60.

[0027] In some embodiments, such as Figure 2 As shown, the electrical connector includes an adapter 300 and a terminal (not shown in the figure), with the terminal disposed on a cover plate 500. At least one end of the tab 200 is connected to one side (the side closer to the tab 200) of the same polarity of the adapter 300 via the plurality of welded portions 400, and the other side (the side away from the tab 200) of the adapter 300 is electrically connected to the terminal of the same polarity. Specifically, the electrical connection between the adapter 300 and the terminal can be welding, riveting, etc. In this case, the minimum distance L between the weld portion 400 closest to the edge of the tab 200 and the edge of the cell body 100 does not directly affect the width of the electrode post in the width direction of the cell body 100. Therefore, in this case, L can be appropriately reduced to obtain a larger weld portion area. Thus, the range of L / B can be further narrowed to: 0.05≤L / B≤0.50. For example, the value of L / B can be 0.05, 0.10, 0.25, 0.30, 0.35, 0.40, 0.45, or 0.50.

[0028] In some embodiments, the tab 200 at one end corresponds to only one pole of the same polarity.

[0029] In some embodiments, the tab 200 at one end corresponds to two or more poles of the same polarity.

[0030] In some embodiments, when the electrical connector includes an adapter 300 and a terminal post, the connection area between the terminal post and the adapter is located between adjacent welded portions 400 of the plurality of welded portions 400.

[0031] In some embodiments, when the electrical connector includes an adapter 300 and a terminal post, in the width direction of the cell body 100, among the plurality of welded portions, the distance between the welded portion with the smallest area and the connection point between it and the adapter 300 and the terminal post is smaller than the distance between the other welded portions and the connection points between them. This results in a larger current-carrying area for the welded portion 400 that is farther from the connection area of ​​the terminal post and the adapter, thereby preventing current concentration from passing through the welded portion 400 that is closer to the connection area of ​​the terminal post and the adapter, thus avoiding the problem of very small current flow in the welded portion 400 that is farther from the connection area of ​​the terminal post and the adapter, and the problem of the welded portion 400 that is closer to the connection area of ​​the terminal post and the adapter being prone to overheating and melting.

[0032] In some embodiments, the tabs 200 at both ends are connected to a plurality of welded portions 400 and electrical connectors of the same polarity, which are arranged sequentially at intervals along the width direction of the cell body 100. This arrangement at both ends further helps to reduce the internal resistance of the battery. For example, Figure 2 In the middle, the tab 200 at one end is connected to the same polarity adapter 300 by two welding parts 400 arranged sequentially at intervals along the width direction of the cell body 100, and the tab 200 at the other end is connected to the same polarity adapter 300 by two other welding parts 400 arranged sequentially at intervals along the width direction of the cell body 100.

[0033] In some embodiments, the multiple welded portions 400 corresponding to the tabs 200 at both ends are symmetrically distributed about the centerline (pointed to by D in the figure) along the length of the cell body 100. This ensures a more balanced current flow at both ends.

[0034] The above embodiments can be freely combined without conflict.

[0035] The above examples illustrate the principles and implementation methods of this application. The descriptions of these embodiments are merely for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A battery, characterized in that, The device includes a battery cell and electrical connectors. The battery cell includes a cell body and tabs. The tabs extend from both ends of the cell body along its length, and the tabs at both ends have different polarities. The length of the cell body is A, and the range of A is 150mm ≤ A ≤ 1500mm. The width of the cell body is B, and the range of B is 50mm ≤ B ≤ 280mm. At least one end of the tab is connected to an electrical connector of the same polarity through a plurality of welded portions arranged at intervals along the width direction of the cell body. In the width direction of the cell body, the minimum distance between the welded portion closest to the edge of the tab and the edge of the cell body is L, where 0.05 ≤ L / B ≤ 0.

60.

2. The battery according to claim 1, characterized in that, In the width direction of the cell body, the minimum spacing between adjacent welded portions among the plurality of welded portions is M, where 0.20≤M / B≤0.

80.

3. The battery according to claim 1, characterized in that, In the width direction of the cell body, the minimum distance between adjacent welded portions among the plurality of welded portions is M, and the minimum distance between the welded portion closest to the edge of the tab and the edge of the cell body among the plurality of welded portions is L, 0.1≤L / M≤0.

7.

4. The battery according to claim 1, characterized in that, The ratio of the total area of ​​the plurality of welded portions to the area of ​​the first end face of the electrode where the plurality of welded portions are located ranges from 0.05 to 0.

40.

5. The battery according to claim 1, characterized in that, The ratio of the area of ​​the smallest welded part to the area of ​​the largest welded part among the plurality of welded parts is in the range of 0.1-1.

6. The battery according to claim 1, characterized in that, The electrical connector includes a terminal post, and the electrode tab at at least one end is connected to the terminal post of the same polarity via the plurality of solder joints; or, The electrical connector includes an adapter and a pole. At least one end of the pole is connected to one side of the adapter of the same polarity via the plurality of welded parts, and the other side of the adapter is electrically connected to the pole of the same polarity.

7. The battery according to claim 1, characterized in that, The electrical connector includes a pole, and at least one end of the tab is connected to the pole of the same polarity through the plurality of welded parts, 0.20≤L / B≤0.

60.

8. The battery according to claim 1, characterized in that, The electrical connector includes an adapter and a pole. At least one end of the pole is connected to one side of the adapter of the same polarity via the plurality of welded parts. The other side of the adapter is electrically connected to the pole of the same polarity. 0.05≤L / B≤0.

50.

9. The battery according to claim 8, characterized in that, In the width direction of the cell body, the distance between the weld with the smallest area among the plurality of welded parts and the connection point of the adapter and the pole is smaller than the distance between the other welded parts and the connection points of the adapter and the pole.

10. The battery according to any one of claims 1-9, characterized in that, The tabs at both ends are connected by a plurality of welding portions and electrical connectors of the same polarity arranged sequentially at intervals along the width direction of the battery cell body.

11. The battery according to claim 10, characterized in that, The multiple welding portions corresponding to the tabs at both ends are symmetrically distributed about the length of the battery cell body.

Images