Tab, battery and battery pack

Abstract

The utility model provides a connecting piece, battery and battery package, connecting piece includes first connecting portion, second connecting portion and fuse portion, fuse portion connects between first connecting portion and second connecting portion, fuse portion is equipped with at least two openings to form at least three mutually parallel conductive parts, so that the current on each conductive part is smaller, thereby avoiding the heat concentration caused by the excessive local current, and the cross section area of each conductive part relative to the whole original fuse portion is smaller, facilitating the quick response disconnection of the connecting piece under abnormal conditions.

Description

Technical Field

[0001] This utility model relates to the field of power battery technology, specifically to a connecting piece, a battery, and a battery pack. Background Technology

[0002] With the development of fast charging technology for battery cells, new requirements have been placed on the overcurrent capacity of the connecting pieces. Existing connecting pieces can break the circuit after heating up and melting under abnormally large current. However, the current path of the connecting pieces is small, which leads to localized overheating concentration and the inability to quickly disconnect under abnormal conditions. This is a problem that needs to be addressed.

[0003] Therefore, the related technologies suffer from the technical problem of localized overheating and concentration of the connecting pieces in the battery, which cannot be quickly disconnected. Utility Model Content

[0004] The embodiments of this utility model provide a connecting piece, a battery, and a battery pack, which can improve the technical problem in the prior art where the connecting piece of the battery has localized overheating and cannot be quickly disconnected.

[0005] In a first aspect, embodiments of the present invention provide a connecting piece applied to a battery, comprising:

[0006] The first connecting part is connected to the battery top cover;

[0007] A second connecting portion, the second connecting portion being connected to the electrode tab; and

[0008] A fusible part is connected between the first connecting part and the second connecting part. The fusible part has at least two openings, and the fusible part is separated by the openings to form at least three conductive parts connected in parallel.

[0009] In one embodiment, the width direction of the connecting piece is defined as a first direction, the openings are arranged along the first direction, and the ratio of the sum of the widths of the openings on the fuse portion to the overall width of the fuse portion is in the range of 0.6 to 0.85.

[0010] In one embodiment, the width of the opening ranges from 2 mm to 8 mm.

[0011] In one embodiment, the thickness of the connecting piece ranges from 0.4 mm to 1.2 mm.

[0012] In one embodiment, the fused portion includes at least two fused structures along the thickness direction of the connecting piece.

[0013] In one embodiment, a layer of highly thermally conductive material is filled between two adjacent layers of the fused structure.

[0014] In one embodiment, a filling region is further included, the filling region being filled with the high thermal conductivity material layer, the filling region being offset from the opening of the fused portion.

[0015] In one embodiment, the cross-sectional shape of the opening is one or more combinations of circular, square, elliptical or other geometric shapes, and the cross-sectional shape of the fuse portion is one of straight, wavy or other irregular shapes.

[0016] Secondly, embodiments of the present invention provide a battery, including tabs, a battery top cover, and a connecting piece as described in any of the above embodiments, wherein the connecting piece is used to connect the battery top cover and the tabs.

[0017] Thirdly, embodiments of the present invention provide a battery pack including the battery as described in the above embodiments.

[0018] The beneficial effects of the embodiments of this utility model are as follows:

[0019] In an embodiment of this utility model, at least two openings are provided in the fusible portion between two adjacent connecting portions of the connecting piece. The design of at least two openings enables the fusible portion to form at least three conductive portions connected in parallel. The current on each conductive portion is smaller, thereby avoiding heat concentration caused by excessive local current. At the same time, the cross-sectional area of ​​each conductive portion is smaller than that of the original fusible portion as a whole, which facilitates the rapid response and disconnection of the connecting piece in abnormal situations. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the connecting piece provided in an embodiment of this utility model;

[0022] Figure 2 This is a schematic diagram of the longitudinal section of the connecting piece provided in an embodiment of this utility model.

[0023] 1. Connecting piece; 11. First connecting part; 12. Fusible part; 13. Second connecting part; 2. Opening; 3. Fusible structure; 4. High thermal conductivity material layer; 5. Filling area; 6. Connecting hole; 7. First direction. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present utility model and are not intended to limit the present utility model. In the present utility model, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0025] Furthermore, the terms "first," "second," and similar words do not indicate any order, quantity, or importance, but are merely used to distinguish different technical features. The terms "multiple" and similar words indicate two or more unless otherwise expressly specified.

[0026] Please see Figure 1 The connecting piece 1 provided in the embodiment of this utility model is applied to a battery. The connecting piece 1 includes two connecting parts 11 and a fusible part 12. The fusible part 12 is connected between adjacent first connecting parts 11 and second connecting parts 13. At least two openings 2 are provided on the fusible part 12, and at least three conductive parts connected in parallel are formed on the fusible part 12.

[0027] The first connecting part 11 is connected to the top cover of the battery, and the second connecting part 13 is connected to the electrode tab.

[0028] Among them, three conductive parts connected in parallel are used to connect two adjacent connecting parts 11.

[0029] One of the connecting parts 11 is provided with a connecting hole 66, and the connecting piece 1 is connected to the battery top cover through the connecting hole 66.

[0030] In this embodiment, by providing at least two openings 2 in the fuse portion 12 of the connecting piece 1, the design of at least two openings 2 enables the fuse portion 12 to form at least three conductive portions connected in parallel. The current on each conductive portion is smaller, thereby avoiding heat concentration caused by excessive local current. At the same time, the cross-sectional area of ​​each conductive portion is smaller than that of the original fuse portion 12 as a whole, which facilitates the rapid response and disconnection of the connecting piece 1 in abnormal situations.

[0031] In one embodiment, please refer to Figure 1 The ratio of the sum of the widths of the openings 2 on the fuse section 12 to the overall width of the fuse section 12 ranges from 0.6 to 0.85.

[0032] The ratio of the sum of the widths of the openings 2 on the fuse section 12 to the overall width of the fuse section 12 can be any one of 0.6, 0.7, 0.8, or 0.85.

[0033] When the sum of the widths of the openings 2 on the fuse section 12 is less than 0.6 compared to the overall width of the fuse section 12, the threshold current for the fuse section 12 to melt is too high, which means that under abnormal conditions, the fuse section 12 cannot melt in time to protect the battery cell.

[0034] When the ratio of the sum of the widths of the openings 2 on the fuse section 12 to the overall width of the fuse section 12 is greater than 0.85, the tensile strength of the fuse section 12 decreases, and it may break under normal working conditions.

[0035] It is understandable that the ratio of the sum of the widths of the openings 2 on the fuse portion 12 to the overall width of the fuse portion 12 is in the range of 0.6 to 0.85, which can ensure that the heat generated during melting is sufficient to cut the metal connection, while avoiding excessive burning.

[0036] In one embodiment, please refer to Figure 1 The width direction of the connecting piece 1 is defined as the first direction 7, and the width of the opening 2 along the first direction 7 ranges from 2mm to 8mm.

[0037] The width of the opening can be any one of 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, or 8mm.

[0038] It is understandable that when the width of the opening 2 is less than 2mm, burrs are easily generated at the opening 2 position, which leads to abnormal stress concentration at the opening 2 position; when the width of the opening 2 is greater than 8mm, it will delay the melting response time.

[0039] In this embodiment, by ensuring that the width of the opening 2 in the first direction 7 of the fusion section 12 of the connecting piece 1 is between 2mm and 8mm, it is possible to avoid stress concentration caused by burrs at the opening 2 position. At the same time, the connecting piece 1 can quickly perform a fusion response, which improves the fusion response efficiency and better protects the connecting piece 1 and the battery under abnormal conditions.

[0040] In one embodiment, the thickness of the connecting piece 1 ranges from 0.4 mm to 1.2 mm.

[0041] The thickness of the connecting piece 1 can be any one of 0.4mm, 0.8mm, or 1.2mm.

[0042] It is understandable that when the thickness of connecting piece 1 is less than 0.4mm, the yield strength of connecting piece 1 decreases, and fatigue cracks are easily generated during battery cycle charging and discharging. When the thickness of connecting piece 1 is greater than 1.2mm, the resistance of connecting piece 1 decreases, requiring a larger abnormal current to melt and thus losing its protective significance.

[0043] In this embodiment, by using a thickness range of 0.4 mm to 1.2 mm for the connecting piece 1, fatigue cracks in the connecting piece 1 can be avoided, while the fusing threshold current of the fusing part 12 is reduced, making the fusing more sensitive.

[0044] In one embodiment, please refer to Figure 2 Along the thickness direction of the connecting piece 1, the fusion section 12 includes at least two layers of fusion structure 3.

[0045] The fusible part 12 has at least two layers of fusible structure 3 in the thickness direction so that a larger current can pass through safely, thereby improving the safe current carrying capacity.

[0046] It is understood that the fusing part 12 can have a four-layer structure, with the thickness of each layer ranging from 0.1mm to 0.3mm, so that the thickness of the fusing part 12 meets the requirement of 0.4mm to 1.2mm. When the fusing part 12 has other layers, the total thickness of the fusing part 12 can also meet the requirement of 0.4mm to 1.2mm, so as to avoid fatigue cracks in the connecting piece 1 and make the fusing more sensitive.

[0047] In one embodiment, a layer 4 of highly thermally conductive material is filled between two adjacent layers.

[0048] The material of the fusible part 12 is any one of nickel, copper, or nickel-copper composite material.

[0049] The high thermal conductivity material can be one of graphene, carbon nanotubes, or metal foam.

[0050] It is understandable that a high thermal conductivity material is filled between two adjacent layers, preferably graphene. The high thermal conductivity material is used to improve heat dissipation efficiency, reduce heat generation of the battery under fast charging conditions, and avoid heat concentration.

[0051] In one embodiment, the high thermal conductivity material layer 4 is distributed with a gradient concentration, and the coating density of the high thermal conductivity material layer 4 near the battery cell side is higher than the coating density of the high thermal conductivity material layer 4 away from the battery cell side.

[0052] The coating density of the high thermal conductivity material layer 4 near the battery cell side can be 1.5 to 3 times that of the coating density of the high thermal conductivity material layer 4 far from the battery cell side.

[0053] It is understood that the above gradient concentration distribution refers to the coating density of the high thermal conductivity material layer 4 in at least two layers of fused structure 3 of the connecting piece 1 gradually decreasing from the side closer to the cell to the side farther away from the cell, thereby optimizing the directional heat dissipation capability. This results in a high coating density of the high thermal conductivity material layer 4 on the cell side to quickly absorb the heat generated by the battery, and a low coating density on the side farther away from the cell to gradually release heat to the environment and avoid heat accumulation.

[0054] Understandably, high thermal conductivity materials with high coating density can also delay the temperature rise of the fuse section 12 to avoid premature melting under abnormal current, while ensuring heat dissipation efficiency.

[0055] It should be noted that the coating of the high thermal conductivity material layer 4 can be prepared by spraying or printing technology, and the coating thickness of different areas can be controlled by masking process; or, films of high thermal conductivity material layer 4 with different gradient concentrations can be pre-prepared and then pressed together with the connecting piece 1.

[0056] It should be noted that using graphene as a high thermal conductivity material can achieve higher thermal conductivity, while using carbon nanotubes as a high thermal conductivity material can achieve higher mechanical strength.

[0057] In one embodiment, the connecting piece 1 is any one of a rectangular, L-shaped, or irregular structure to adapt to different battery top cover layouts.

[0058] Understandably, the shape design of the connecting piece 1 directly affects its compatibility with the battery top cover, space utilization, and the uniformity of current distribution.

[0059] Among them, compatibility refers to: it can be adapted to different top cover structures such as cylindrical, square, and pouch batteries.

[0060] The shape design of the connecting piece 1 can also achieve current carrying optimization. For example, the irregular shape design can shorten the current path and reduce the resistance.

[0061] The shape design of the connecting piece 1 can also enhance heat dissipation. Special shapes, such as irregular designs with heat dissipation fins, can increase the heat dissipation area to enhance heat dissipation capacity.

[0062] The irregular structure includes cutouts or protrusions to match the internal space of the battery casing.

[0063] It should be noted that when the connecting piece 1 is rectangular, it conforms to standardized production and is suitable for large-scale battery packs; when the connecting piece 1 is L-shaped or irregularly shaped, it can shorten the circuit path and enhance heat dissipation.

[0064] In one embodiment, the opening 2 can be formed by laser cutting or stamping, so that the edges are chamfered to reduce stress concentration.

[0065] In one embodiment, the area filled with graphene material is defined as the filling region 5, which is offset from the opening 2 of the fused portion 12.

[0066] Among them, the filling area 5 can be distributed in a grid pattern.

[0067] It is understandable that the filling area 5 and the opening 2 of the fuse part 12 are staggered to ensure that the heat dissipation channel and the fuse area do not interfere with each other, avoid the thermal conductive material from affecting the reliability of the fuse function, and at the same time maintain the mechanical strength of the connecting piece 1. The staggered arrangement can ensure that the fuse part 12 can quickly reach the fuse temperature during overcurrent.

[0068] In one embodiment, the cross-sectional shape of the opening 2 is one or more combinations of a circle, a square, an ellipse, or other geometric shapes.

[0069] In one embodiment, the cross-sectional shape of the fuse portion 12 is one of a straight line, a wavy line, or other irregular shapes.

[0070] Secondly, embodiments of the present invention provide a battery, including tabs, a battery top cover, and a connecting piece 1 as described in any of the above embodiments, wherein the connecting piece 1 is used to connect the battery top cover and the tabs.

[0071] It is understood that by using the connecting piece 1 of any of the above embodiments, safe current carrying under high-rate charging and discharging and rapid disconnection under abnormal conditions can be achieved. Under the action of abnormal high current, the connecting piece 1 is melted by the fuse part 12 to disconnect the circuit.

[0072] Thirdly, embodiments of the present invention provide a battery pack, including a connecting piece 1 as described in any of the above embodiments, or a battery as described in the above embodiments.

[0073] The embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A connecting piece (1) applied to a battery, characterized in that, include: The first connecting part (11) is connected to the top cover of the battery; The second connecting part (13) is connected to the electrode tab; and A fusible part is connected between the first connecting part (11) and the second connecting part (13). The fusible part (12) has at least two openings (2). The fusible part (12) is separated by the openings to form at least three conductive parts connected in parallel.

2. The connecting piece (1) according to claim 1, characterized in that, The width direction of the connecting piece (1) is defined as the first direction (7), the openings (2) are arranged along the first direction (7), and the ratio of the sum of the widths of the openings (2) on the fuse portion (12) to the overall width of the fuse portion (12) is in the range of 0.6 to 0.

85.

3. The connecting piece (1) according to claim 2, characterized in that, The width of the opening (2) ranges from 2 mm to 8 mm.

4. The connecting piece (1) according to claim 1, characterized in that, The thickness of the connecting piece (1) ranges from 0.4 mm to 1.2 mm.

5. The connecting piece (1) according to claim 1, characterized in that, Along the thickness direction of the connecting piece (1), the fusion section (12) includes at least two layers of fusion structure (3).

6. The connecting piece (1) according to claim 5, characterized in that, A layer of highly thermally conductive material (4) is filled between two adjacent layers of the fused structure (3).

7. The connecting piece (1) according to claim 6, characterized in that, It also includes a filling region (5), which is filled with the high thermal conductivity material layer (4), and the filling region (5) is staggered from the opening (2) of the fuse portion (12).

8. The connecting piece (1) according to claim 1, characterized in that, The cross-sectional shape of the opening (2) is one or more combinations of circular, square, elliptical or other geometric shapes, and the cross-sectional shape of the fuse part (12) is one of straight, wavy or other irregular shapes.

9. A battery, characterized in that, It includes a tab, a battery top cover, and a connecting piece (1) as described in any one of claims 1 to 8, wherein the connecting piece (1) connects the battery top cover and the tab.

10. A battery pack, characterized in that, Includes the battery as described in claim 9.

Images