Battery

Abstract

Battery that includes: a housing with an opening; a cover plate mounted on the opening, the cover plate being provided with a through hole; a terminal post, at least a portion of the terminal post being disposed in the through-hole; a battery cell comprising a battery cell main body and an electrode tab, wherein the battery cell main body is arranged in the housing, the electrode tab comprises a first connecting portion, a fuse portion, and a second connecting portion connected in series, and the cross-sectional areas of the first connecting portion and the second connecting portion are both larger than the cross-sectional area of ​​the fuse portion, wherein the first connecting portion is connected to the battery cell main body and the second connecting portion is connected to one end of the terminal post located inside the housing; wherein the electrode tab comprises a plurality of electrode tab pieces stacked together, each electrode tab piece comprising a first partial connecting portion, a partial securing portion, and a second partial connecting portion connected in series, all first partial connecting portions of the electrode tab are stacked together to form the first connecting portion, all second partial connecting portions of the electrode tab are stacked together to form the second connecting portion, all partial securing portions of the electrode tab are welded together to form the securing portion, and a first welding mark is formed on one side of the electrode tab.

Description

TECHNICAL AREA

[0001] The present utility model relates to the field of battery technology and in particular to a battery. BACKGROUND

[0002] Since the commercialization of lithium-ion energy batteries, they are currently being rapidly and widely used in various electrical devices due to their numerous advantages such as light weight, high voltage, small volume, no memory effect, high specific energy, long cycle life and environmental friendliness.

[0003] To ensure battery safety, conventional batteries typically have a fuse section on the electrode tab that melts when the short-circuit current exceeds the melting current of the fuse section, thereby breaking the connection to the battery cell.

[0004] However, in wound battery cells, multiple electrode tabs extend outward from the electrode plate and are stacked together to form an electrode tab. Each electrode tab has a partial fuse section. These multiple electrode tabs are separated from each other. As a result, during a short circuit that melts the fuse section, some partial fuse sections may not melt, and the already melted partial fuse sections may reconnect and adhere to the unmelted electrode tabs. This means that the battery cell main body and the terminal post remain electrically connected, and the intended high-current protection function of the fuse section is not provided. SUMMARY OF THE UTILITY MODEL

[0005] The object of the present utility model is to create a battery which ensures that the fuse section of the electrode tab can melt completely at a specified current threshold, thereby guaranteeing battery safety.

[0006] To solve the above technical problem, the present utility model provides the following technical solution: Battery that includes: a housing with an opening; a cover plate mounted on the opening, the cover plate being provided with a through hole; a terminal post, at least a portion of the terminal post being disposed in the through-hole; a battery cell comprising a battery cell main body and an electrode tab, wherein the battery cell main body is arranged in the housing, the electrode tab comprises a first connecting portion, a fuse portion, and a second connecting portion connected in series, and the cross-sectional areas of the first connecting portion and the second connecting portion are both larger than the cross-sectional area of ​​the fuse portion, wherein the first connecting portion is connected to the battery cell main body and the second connecting portion is connected to one end of the terminal post located inside the housing; wherein the electrode tab comprises a plurality of electrode tab pieces stacked together, each electrode tab piece comprising a first partial connecting portion, a partial securing portion, and a second partial connecting portion connected in series, all first partial connecting portions of the electrode tab are stacked together to form the first connecting portion, all second partial connecting portions of the electrode tab are stacked together to form the second connecting portion, all partial securing portions of the electrode tab are welded together to form the securing portion, and a first weld mark or weld seam is formed on one side of the electrode tab. Compared with the prior art, the advantageous effects of the battery according to the present utility model are as follows: Since in the present utility model, the electrode tab comprises a plurality of stacked electrode tab pieces, each electrode tab piece includes a first partial connection portion, a partial fuse portion, and a second partial connection portion connected in series. The first partial connection portion is connected to the battery cell main body, and the second partial connection portion is welded to the terminal post. The second partial connection portions of a plurality of electrode tab pieces are welded together and to the terminal post. Then, the plurality of partial fuse portions of a plurality of electrode tab pieces are welded together. This ensures that when the specified current threshold is reached, all partial fuse portions melt simultaneously, successfully breaking the electrical connection between the battery cell main body and the terminal post.If the partial fuse sections of multiple electrode tab pieces were separated from each other when the fuse section melts, some partial fuse sections may not melt, and the already melted partial fuse sections may reconnect and adhere to the unmelted electrode tab pieces, which means that the battery cell main body and the terminal post remain electrically connected and the intended high-current protection function of the fuse section is not provided. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a structural diagram of the battery according to an embodiment of the present utility model; Fig. 2 is a relationship diagram of the battery cell main body, the electrode tab, and the terminal post according to an embodiment of the present utility model; Fig. 3 is a dimensional diagram of the battery cell main body, the electrode tab, and the terminal post according to an embodiment of the present invention; Fig. 4 is another dimensional view of the battery cell main body, the electrode tab, and the terminal post according to an embodiment of the present invention;

[0007] In the figures: 100-housing; 200-cover plate; 300-first weld mark; 400-second weld mark; 1-Battery cell main body; 2-Electrode tab; 21-First connecting section; 22-Safety section; 23-Second connecting section; 3-terminal post. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0008] The specific implementation modes of the present utility model are described in more detail below in conjunction with the drawings and embodiments. The following embodiments serve to illustrate the present utility model, but do not limit the scope of protection of the present utility model.

[0009] In the description of the present utility model, it is understood that the term "comprises / comprising" as used in this description means the presence of specified features, integers, steps, operations, elements / components, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements / components, components, and / or combinations thereof. It should be noted that when an element / component is described as being "connected" to another element / component, it may be directly connected to the other element / component, or intermediate elements / components may be present. The term "and / or" as used herein includes all combinations of one or more of the related recited elements.

[0010] As in the Fig.1 to 4, the present utility model relates to a battery comprising a housing 100, a cover plate 200, a terminal post 3 and a battery cell, wherein the housing 100 has an opening, the cover plate 200 is mounted on the opening, the cover plate 200 is provided with a through hole and at least a portion of the terminal post 3 is arranged in the through hole.

[0011] The battery cell comprises a battery cell main body 1 and an electrode tab 2, wherein the battery cell main body 1 is arranged in the housing 100. The electrode tab 2 includes a first connecting portion 21, a fuse portion 22, and a second connecting portion 23 connected in series, and the cross-sectional areas of the first connecting portion 21 and the second connecting portion 23 are both larger than the cross-sectional area of ​​the fuse portion 22. The first connecting portion 21 is connected to the battery cell main body 1, and the second connecting portion 23 is connected to one end of the terminal post 3 located inside the housing 100.

[0012] The electrode tab 2 comprises a plurality of electrode tab pieces stacked together. Each electrode tab piece comprises a first partial connecting portion, a partial securing portion, and a second partial connecting portion connected in series. All first partial connecting portions of the electrode tab 2 are stacked together to form the first connecting portion 21, all second partial connecting portions of the electrode tab 2 are stacked together to form the second connecting portion 23, all partial securing portions of the electrode tab 2 are welded together to form the securing portion 22, and a first welding mark 300 is formed on one side of the electrode tab 2.

[0013] In the present utility model, since the electrode tab 2 comprises a plurality of stacked electrode tab pieces, each electrode tab piece includes the first partial connection portion, the partial fuse portion, and the second partial connection portion connected in series. The first partial connection portion is connected to the battery cell main body 1, and the second partial connection portion is welded to the terminal post 3. The second partial connection portions of a plurality of electrode tab pieces are welded together and welded to the terminal post 3. Then, the plurality of partial fuse portions of a plurality of electrode tab pieces are welded together. This ensures that when the predetermined current threshold is reached, all the partial fuse portions melt simultaneously, successfully breaking the electrical connection between the battery cell main body 1 and the terminal post 3.If the partial fuse sections of a plurality of electrode tab pieces were separated from each other when the fuse section 22 melts, some partial fuse sections may not melt, and the already melted partial fuse sections may reconnect and adhere to the unmelted electrode tab pieces, which means that the battery cell main body 1 and the terminal post 3 remain electrically connected and the intended high-current protection function of the fuse section 22 is not provided.

[0014] In one embodiment, portions of all partial fuse sections of the electrode tab 2 are welded together, and the area of ​​the first weld mark 300 is smaller than the area of ​​the side surface of the fuse section 22. This can similarly prevent the problem of reconnection and adhesion between melted and unmelted partial fuse sections.

[0015] In another embodiment, all areas of all partial fuse sections of the electrode tab 2 are welded together, and the area of ​​the first welding mark 300 is equal to the area of ​​the side surface of the fuse section 22. This can similarly prevent the problem of reconnection and adhesion between melted and unmelted partial fuse sections.

[0016] In further embodiments, all areas of all partial fuse sections of the electrode tab 2 are welded together, and the area of ​​the first weld mark 300 is larger than the area of ​​the side surface of the fuse section 22. And the first weld mark 300 completely covers the fuse section 22. This can similarly prevent the problem of reconnection and adhesion between melted and unmelted partial fuse sections.

[0017] In particular, areas between the first partial connecting portion and the second partial connecting portion of the electrode tab pieces may be first welded together, then holes may be cut or punched into the welding area to reduce the cross-sectional area of ​​the welding area, thereby forming the securing portion 22 at the position with the minimum cross-sectional area. This helps improve assembly efficiency by avoiding the need to cut multiple electrode tab pieces individually.

[0018] Preferably, the first welding mark 300 is formed on a side surface of the outermost electrode tab piece, and on a heat transfer path from the battery cell to the terminal post 3, a distance between an end of the first welding mark 300 close to the second partial connection portion and an end of the partial securing portion of the electrode tab piece close to the second partial connection portion is L1, where 1 mm ≤ L1 ≤ 8 mm.

[0019] If, on the heat transfer path from the battery cell to the terminal post 3, the distance between the end of the first weld mark 300 near the second partial connection portion and the end of the partial fuse portion of the electrode tab piece near the second partial connection portion is too large, this indicates that the first weld mark 300 is too close to the weld mark between the electrode tab piece 2 and the terminal post 3 due to assembly tolerance. This may cause an overlap between the two weld marks, resulting in a double weld. The strength of the double-welded surface decreases, making the electrode tab 2 prone to breakage and also causing a deviation in the maximum current threshold of the fuse portion 22.If the distance between the end of the first welding mark 300 near the second partial connection portion and the end of the partial fuse portion of the electrode tab piece near the second partial connection portion is too small, the multiple partial fuse portions of the multiple electrode tab pieces that are remote from the welding equipment surface may not be completely welded together, resulting in partial separation. Consequently, when the multiple partial fuse portions of the multiple electrode tab pieces reach the initially set current threshold and melt, adhesion may still occur between the multiple partial fuse portions, meaning that the battery cell main body 1 and the terminal post 3 remain electrically connected, and the intended high-current protection function of the fuse portion 22 is not provided.Therefore, maintaining the distance L1 between the end of the first welding mark 300 close to the second partial connection portion and the end of the partial securing portion of the electrode tab piece close to the second partial connection portion between 1-8mm helps to ensure battery safety.

[0020] In addition, the first welding mark 300 is formed on a side surface of the outermost electrode tab piece, and on the heat transfer path from the battery cell to the terminal post 3, a distance between the end of the first welding mark 300 close to the first partial connection portion and the end of the partial securing portion of the electrode tab piece close to the first partial connection portion is L2, where 1 mm ≤ L2 ≤ 8 mm.

[0021] On the heat transfer path from the battery cell to the terminal post 3, if the distance between the end of the first welding mark 300 close to the first partial connection portion and the end of the partial securing portion of the electrode tab piece close to the first partial connection portion is too large, this indicates that the first welding mark 300 is too close to the battery cell main body 1. This means that when the partial securing portions of a plurality of electrode tab pieces are welded together, the high temperature generated during welding may corrode the battery cell main body 1, resulting in a loss of electrical performance or thermal safety risks.If the distance between the end of the first welding mark 300 near the first partial connection portion and the end of the partial fuse portion of the electrode tab piece near the first partial connection portion is too small, the multiple partial fuse portions of the multiple electrode tab pieces that are remote from the welding equipment surface may not be completely welded together, resulting in partial separation. Consequently, when the multiple partial fuse portions of the multiple electrode tab pieces reach the initially set current threshold and melt, adhesion may still occur between the multiple partial fuse portions, meaning that the battery cell main body 1 and the terminal post 3 remain electrically connected, and the intended high-current protection function of the fuse portion 22 is not provided.Therefore, maintaining the distance L2 between the end of the first welding mark 300 close to the first partial connection portion and the end of the partial securing portion of the electrode tab piece close to the first partial connection portion between 1-8mm helps to ensure battery safety.

[0022] In this embodiment, the second connecting portion 23 is welded to the end of the terminal post 3 located inside the housing 100 to form a second welding mark 400, and on the heat transfer path from the battery cell to the terminal post 3, a distance between the first welding mark 300 and the second welding mark 400 is L3, where 1mm ≤ L3 ≤ 5mm.

[0023] That is, maintaining a gap between the second welding mark 400 formed by connecting the second connecting portion 23 of the electrode tab 2 to the terminal post 3 and the first welding mark 300 on the electrode tab 2 allows the plurality of electrode tab pieces to be scattered between the first welding mark 300 and the second welding mark 400, thereby providing a buffer effect against tensile forces. This ensures that vibrations are not easily transmitted from the terminal post 3 to the securing portion 22 of the electrode tab 2, preventing the securing portion 22 from easily breaking.In addition, maintaining the distance L3 between the first welding mark 300 and the second welding mark 400 between 1-5 mm ensures that the second welding mark 400 is not too close to the first welding mark 300, providing a buffer effect, while also preventing the first welding mark 300 from being too close to the battery cell main body 1, thereby avoiding the effect of the welding temperature on the battery cell main body 1.

[0024] Preferably, on the heat transfer path from the battery cell to the terminal post 3, a distance between an end of the fuse portion 22 remote from the first connecting portion 21 and an end of the fuse portion 22 close to the first connecting portion 21 is L4, where 0.4 ≤ L4 / L3 ≤ 8.

[0025] On the heat transfer path from the electrode tab 2 to the terminal post 3, if the ratio of the distance L4 (between the end of the securing portion 22 remote from the first connecting portion 21 and the end of the securing portion 22 close to the first connecting portion 21) to the distance L3 (between the first welding mark 300 and the second welding mark 400) is too large, this indicates that the securing portion 22 is too long and prone to breakage due to vibration, while the short distance between the first welding mark 300 and the second welding mark 400 creates a low buffer capacity, making the securing portion 22 prone to breakage.If the ratio of the distance L4 to the distance L3 is too small, it indicates that the fuse section 22 is too small, while the distance between the first weld mark 300 and the second weld mark 400 is too long, causing the fuse section 22 to fail to meet the melting time requirements. Therefore, maintaining L4 / L3 (the ratio of the distance L4 to the distance L3) between 0.4-8 can ensure the proper function of the fuse section 22.

[0026] In other embodiments, the second connecting portion 23 is welded to the end of the terminal post 3 located inside the housing 100 to form a second welding mark 400, and the first welding mark 300 and the second welding mark 400 are connected to each other.

[0027] That is, directly welding a lead onto the electrode tab 2, welding a long strip when welding the electrode tab 2 and the terminal post 3, and then cutting the welded surface to form the fuse portion 22 can improve the assembly efficiency.

[0028] In this embodiment, the second connecting portion 23 is welded to the end of the terminal post 3 located inside the housing 100 to form a second welding mark 400, and on the heat transfer path from the battery cell to the terminal post 3, a distance L5 between the securing portion 22 and the second welding mark 400 is L5, where 1mm ≤ L5 ≤ 10mm.

[0029] On the heat transfer path from the electrode tab 2 to the terminal post 3, if the distance between the fuse portion 22 and the second welding mark 400 is too small, the heat generated during welding of the electrode tab 2 to the terminal post 3 may affect the fuse portion 22, causing partial melting. Furthermore, if the fuse portion 22 is too close to the terminal post 3, it is prone to breakage due to pulling or vibration, which affects the performance of the fuse portion 22. If the distance between the fuse portion 22 and the second welding mark 400 is too large, it means that the fuse portion 22 is far from the terminal post 3 and close to the battery cell main body 1, which may easily affect the performance of the battery cell main body 1.Therefore, maintaining the distance L5 between the fuse portion 22 and the second welding mark 400 between 1-10mm ensures the battery performance.

[0030] It should be emphasized that the areas of the first welding mark 300 and second welding mark 400 refer to the areas of the welding areas.

[0031] The above description represents only preferred embodiments of the present utility model. It should be noted that for those of ordinary skill in the art, various improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the scope of the present utility model.

Claims

[1] Battery comprising: a housing with an opening; a cover plate mounted on the opening, the cover plate being provided with a through hole; a terminal post, at least a portion of the terminal post being disposed in the through-hole; a battery cell comprising a battery cell main body and an electrode tab, wherein the battery cell main body is arranged in the housing, the electrode tab comprises a first connecting portion, a fuse portion, and a second connecting portion connected in series, and the cross-sectional areas of the first connecting portion and the second connecting portion are both larger than the cross-sectional area of ​​the fuse portion, wherein the first connecting portion is connected to the battery cell main body and the second connecting portion is connected to one end of the terminal post located inside the housing; wherein the electrode tab comprises a plurality of electrode tab pieces stacked together, each electrode tab piece comprising a first partial connecting portion, a partial securing portion, and a second partial connecting portion connected in series, all first partial connecting portions of the electrode tab are stacked together to form the first connecting portion, all second partial connecting portions of the electrode tab are stacked together to form the second connecting portion, all partial securing portions of the electrode tab are welded together to form the securing portion, and a first welding mark is formed on one side of the electrode tab. [2] Battery according to claim 1, wherein partial areas of all partial securing sections of the electrode tab are welded together. [3] A battery according to any one of the preceding claims, wherein all areas of all partial securing portions of the electrode tab are welded together and an area of ​​the first welding mark is equal to an area of ​​a side surface of the securing portion. [4] A battery according to any one of the preceding claims, wherein all areas of all partial securing portions of the electrode tab are welded together and an area of ​​the first welding mark is larger than an area of ​​a side surface of the securing portion. [5] The battery according to claim 4, wherein the first welding mark is formed on a side surface of the outermost electrode tab piece, and on a heat transfer path from the battery cell to the terminal post, a distance between an end of the first welding mark close to the second partial connection portion and an end of the partial securing portion of the electrode tab piece close to the second partial connection portion is L1, where 1mm ≤ L1 ≤ 8mm. [6] The battery according to claim 4 or 5, wherein the first welding mark is formed on a side surface of the outermost electrode tab piece, and on a heat transfer path from the battery cell to the terminal post, a distance between an end of the first welding mark close to the first partial connection portion and an end of the partial securing portion of the electrode tab piece close to the first partial connection portion is L2, where 1mm ≤ L2 ≤ 8mm. [7] A battery according to any one of the preceding claims, wherein the second connecting portion is welded to the end of the terminal post located inside the casing to form a second welding mark, and on a heat transfer path from the battery cell to the terminal post, a distance between the first welding mark and the second welding mark is L3, where 1mm ≤ L3 ≤ 5mm. [8] The battery according to claim 7, wherein, on the heat transfer path from the battery cell to the terminal post, a distance between an end of the fuse portion remote from the first connecting portion and an end of the fuse portion close to the first connecting portion is L4, where 0.4 ≤ L4 / L3 ≤ 8. [9] A battery according to any one of the preceding claims, wherein the second connecting portion is welded to the end of the terminal post located inside the housing to form a second welding mark, and the first welding mark and the second welding mark are connected to each other. [10] A battery according to any one of the preceding claims, wherein the second connecting portion is welded to the end of the terminal post located inside the casing to form a second welding mark, and on a heat transfer path from the battery cell to the terminal post, a distance between the securing portion and the second welding mark is L5, where 1mm ≤ L5 ≤ 10mm. [11] A battery according to any one of the preceding claims, which is a lithium-ion energy battery. [12] A battery according to any one of the preceding claims, wherein the battery cell is wound.

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