Connecting piece

Abstract

The utility model provides a connecting piece, which is used for connecting a pole and a tab in a battery and is provided with a tab welding area used for welding the tab. The connecting sheet is also provided with a concave-convex structure, and at least part of the concave-convex structure is positioned in the tab welding area so as to increase the contact area between the tab and the tab welding area; the concave-convex structure comprises a plurality of first grooves, the first grooves are in a long strip shape, and at least part of the first grooves are parallel to one another. According to the embodiment of the utility model, the concave-convex structure is arranged on the connecting piece, and at least part of the concave-convex structure is positioned in the tab welding area, so that the contact area between the tab and the tab welding area is increased, and the technical problem that the connection between the tab and the connecting piece is unstable is solved.

Description

Technical Field

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

[0002] A battery generally includes a casing, battery cells housed within the casing, electrolyte, and a cover plate for sealing the casing. The battery cell contains tabs, and the cover plate has terminals; the tabs and terminals are electrically connected via connecting tabs.

[0003] In related technologies, the connection between the connecting piece and the tab is unstable and prone to desoldering, which reduces the stability and safety of the battery. Utility Model Content

[0004] An embodiment of this utility model provides a connecting piece that can improve the technical problem of unstable connection between the electrode and the connecting piece in related technologies.

[0005] In a first aspect, embodiments of the present invention provide a connecting piece for connecting a terminal post and a tab in a battery, the connecting piece having a tab welding area for welding the tab;

[0006] The connecting piece is also provided with a concave-convex structure, which is at least partially located in the electrode welding area to increase the contact area between the electrode and the electrode welding area;

[0007] The concave-convex structure includes a plurality of first grooves, each groove being elongated and at least a portion of which are parallel to each other.

[0008] In one embodiment, the depth of the first groove is d1, where d1 ≤ 0.1 mm.

[0009] In one embodiment, the depth of the first groove is d1, the thickness of the connecting piece is d2, and 0.05≤d1 / d2≤0.07.

[0010] In one embodiment, the width of the first groove is a, where 0.05mm ≤ a ≤ 0.1mm.

[0011] In one embodiment, the distance between at least two adjacent first grooves is b, where 0.05mm ≤ b ≤ 0.1mm.

[0012] In one embodiment, one end of the connecting piece is provided with a mounting hole, the mounting hole being used to accommodate a portion of the pole post for connecting the pole post.

[0013] In one embodiment, the inner wall of the mounting hole is provided with a stepped surface, which is used to abut against the pole post.

[0014] In one embodiment, the distance between the concave-convex structure and at least one edge adjacent to the connecting piece is L, where 0.05mm≤L≤0.1mm.

[0015] In one embodiment, the number of electrode welding areas is at least two, and the connecting piece is provided with at least one electrode welding area on each side edge along the first direction;

[0016] Along the first direction, the distance from the concave-convex structure to at least one edge of the connecting piece is L1, where 0.05mm≤L1≤0.1mm.

[0017] In one embodiment, along the second direction, the distance between the concave-convex structure and at least one edge of the connecting piece is L2, where 0.05mm≤L2≤0.1mm; the second direction is perpendicular to the first direction.

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

[0019] In embodiments of this invention, by providing a concave-convex structure on the connecting piece, and ensuring that at least a portion of the concave-convex structure is located within the electrode welding area, the contact area between the electrode and the electrode welding area is increased, thereby improving the technical problem of unstable connection between the electrode and the connecting piece. Furthermore, the concave-convex structure on the connecting piece allows various forces acting on it to be more evenly distributed, thus improving the bending resistance of the connecting piece and reducing the probability of warping during manufacturing or welding, thereby increasing battery production efficiency. 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 connection between the connecting piece and the electrode provided in an embodiment of this utility model;

[0023] Figure 3 yes Figure 1 EE cross-sectional view of the connecting piece;

[0024] Figure 4 yes Figure 3 Enlarged view of point B in the middle;

[0025] Figure 5 This is a schematic diagram of the connecting piece provided in an embodiment of this utility model;

[0026] Figure 6 This is a schematic diagram of the connection between the connecting piece and the pole provided in an embodiment of this utility model;

[0027] Figure 7 yes Figure 6 FF cross-sectional view of the connecting piece and the pole;

[0028] Figure 8 yes Figure 1 Enlarged view of point A in the middle.

[0029] The labels in the diagram are as follows:

[0030] 1. Connecting piece;

[0031] 11. Electrode welding area; 12. Concave-convex structure; 121. First groove; 13. Mounting hole; 131. Stepped surface;

[0032] 21. Pole post; 22. Pole tab;

[0033] H1, First Direction;

[0034] H2, Second Direction. Detailed Implementation

[0035] 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.

[0036] The welding area between the connecting piece and the electrode is limited by the size of the connecting piece and the electrode themselves, which results in the battery's overcurrent capacity always being in a low state, thus limiting the charging and discharging capacity of the power battery, and also causing the overall structural strength of the connection between the connecting piece and the electrode to be weak.

[0037] The inventors discovered that by using auxiliary welding pieces, the auxiliary welding pieces are first welded to the surface of the connecting pieces, and then the electrode tabs are inserted between the auxiliary welding pieces and the connecting pieces. Finally, the stacked auxiliary welding pieces, electrode tabs, and connecting pieces are ultrasonically welded. However, this solution introduces new components, increasing the battery manufacturing cost and difficulty, leading to reduced production efficiency.

[0038] Based on this, in this embodiment of the application, by creating a concave-convex structure on the connecting piece, the contact area between the connecting piece and the electrode tab is increased without changing the overall size of the connecting piece or adding new components, thereby improving the technical problem of low welding strength between the electrode tab and the connecting piece. A detailed explanation follows.

[0039] According to the first aspect of this utility model, referring to Figure 1 and Figure 2 This utility model embodiment provides a connecting piece 1, which has a tab welding area 11 for welding tabs 22.

[0040] The connecting piece 1 is also provided with a concave-convex structure 12, which is at least partially located in the electrode welding area 11 to increase the contact area between the electrode 22 and the electrode welding area 11.

[0041] The concave-convex structure 12 includes a plurality of first grooves 121, each of which is elongated and at least some of the first grooves 121 are parallel to each other.

[0042] During the welding process between the connecting piece 1 and the tab 22, the tab 22 is first placed on the tab welding area 11 of the connecting piece 1. Due to the presence of the concave-convex structure 12, the tab 22 can make more thorough contact with the protrusions and grooves in the concave-convex structure 12. During welding, heat is concentrated in the tab welding area 11 and the tab 22 of the connecting piece 1. Part of the tab 22 melts rapidly and flows to the concave-convex structure 12, thus filling the space between the protrusions and grooves. After cooling, the molten part of the tab 22 is in close contact with the concave-convex structure 12. A large number of metal atoms form strong metal bonds during the solidification process, making the connection between the tab 22 and the connecting piece 1 more solid, reducing the probability of poor welding, thereby improving the overall performance and service life of the battery, and ensuring the stability and reliability of the battery during operation.

[0043] The connecting piece 1 can be made of metals such as copper, aluminum, and nickel, or alloys such as stainless steel, giving it good conductivity and welding performance, and enabling it to adapt to the battery's working environment. The concave-convex structure 12 is typically made by cutting, grinding, stamping, or other methods, ensuring the integrity between the concave-convex structure 12 and the connecting piece 1.

[0044] The thickness of the connecting piece 1 can be 1mm to 2mm, so that the connecting piece 1 has good flow capacity and structural strength.

[0045] The concave-convex structure 12 on the connecting piece 1 can significantly improve the bending resistance of the connecting piece 1. Similar to common I-beams and other structures, the grooves and protrusions make the moment of inertia of the connecting piece 1 larger, which can effectively resist bending deformation when subjected to load. Therefore, the concave-convex structure 12 can also be provided on the connecting piece 1 in areas other than the electrode lug welding area 11, and the concave-convex structure 12 can be distributed as evenly as possible on the connecting piece 1. This allows the connecting piece 1 to quickly transmit the force to all parts of the connecting piece 1 when subjected to external force, thereby reducing the probability of bending of the connecting piece 1 and improving the stability of the connecting piece 1.

[0046] Since the connecting piece 1 itself has a small area, the first groove 121 is relatively difficult to process. Therefore, in this embodiment of the utility model, the first groove 121 is set as a strip, so that the first groove 121 on the connecting piece 1 can be easily realized by the cutting process, and can be processed by multiple cutting tools at one time, thereby improving the production efficiency of the connecting piece 1, ensuring the stability of the quality of the connecting piece 1, and being more conducive to large-scale production.

[0047] The elongated first groove 121 also facilitates the flow of molten metal. Some of the molten metal from the tab 22 flows and fills the elongated groove in an orderly manner, which is beneficial for the bonding between the connecting piece 1 and the tab 22, and also reduces the formation of defects such as porosity and slag inclusions. Simultaneously, the partially parallel grooves make the contact between the tab 22 and the connecting piece 1 more regular, ensuring consistent welding quality.

[0048] Furthermore, the parallel elongated grooves 121 help achieve a more uniform stress distribution in the tab welding area 11. When subjected to external forces (such as thermal stress during battery charging and discharging, or forces applied during further processing of the connecting piece 1), the external forces can be more orderly dispersed along the parallel elongated grooves, avoiding stress concentration in local areas. This further reduces the risk of warping or even breakage of the connecting piece 1 due to excessive local stress, and improves the reliability and stability of the connecting piece 1.

[0049] Compared to the traditional flat connecting piece 1, this embodiment of the invention provides a concave-convex structure 12 on the connecting piece 1, with at least a portion of the concave-convex structure 12 located within the tab welding area 11. This increases the contact area between the tab 22 and the tab welding area 11, resulting in a more robust and reliable connection between the tab 22 and the connecting piece 1. This effectively reduces battery malfunctions caused by insufficient welding strength, such as poor soldering. Furthermore, the concave-convex structure 12 on the connecting piece 1 allows various forces acting on it to be more evenly distributed, thereby improving the bending resistance of the connecting piece 1 and reducing the probability of warping during manufacturing or welding, thus improving battery production efficiency.

[0050] In some embodiments, refer to Figure 3 and Figure 4 The depth of the first groove 121 is d1, where d1 ≤ 0.1 mm.

[0051] The depth of the first groove 121 is set to within 0.1 mm, which ensures sufficient structural strength for the connecting piece 1 and makes it easier for the electrode tab 22 to contact the side wall of the first groove 121, thereby increasing the welding area between the electrode tab 22 and the connecting piece 1. For example, the depth of the first groove 121 can be 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm, etc., and this embodiment of the present invention does not limit this.

[0052] In some embodiments, refer to Figure 3 and Figure 4 The depth of the first groove 121 is d1, the thickness of the connecting piece 1 is d2, and 0.05≤d1 / d2≤0.07.

[0053] If the depth d1 of the first groove 121 is too large, making d1 / d2 greater than 0.07, it will excessively weaken the thickness of the connecting piece 1, resulting in a significant reduction in the structural strength of the connecting piece 1. This will easily lead to deformation and breakage during use, affecting the normal use of the battery. Furthermore, an excessively deep first groove 121 will increase the resistance of the connecting piece 1, leading to increased energy loss during battery charging and discharging, while the connecting piece 1 itself will generate significant heat, making it prone to thermal runaway. If the depth d1 of the first groove 121 is too small, making d1 / d2 less than 0.05, the first groove 121 will be too shallow. This will not significantly increase the contact area between the connecting piece 1 and the tab 22, and the molten metal from the tab 22 during welding may not be able to fully fill the first groove 121, resulting in insufficient welding strength.

[0054] Therefore, in this embodiment of the utility model, the range of d1 / d2 is set to 0.05 to 0.07. For example, d1 / d2 can be 0.05, 0.052, 0.054, 0.056, 0.058, 0.06, 0.062, 0.064, 0.066, 0.068, 0.07, etc. This allows the setting of the first groove 121 to increase the contact area with the tab 22 and ensure the welding quality, while also maintaining good structural strength of the connecting piece 1, reducing adverse effects on the conductivity of the connecting piece 1, and ensuring the normal use of the battery.

[0055] In some embodiments, refer to Figure 4 The first groove 121 is elongated, and the width of the first groove 121 is a, where 0.05mm≤a≤0.1mm.

[0056] If the width of the first groove 121 is too large, such that a is greater than 0.1 mm, the first groove 121 will occupy too much space, reducing the structural strength and stability of the connecting piece 1 and making it prone to deformation or even breakage. Moreover, an excessively wide first groove 121 will cause uneven flow and filling of molten metal in the first groove 121 when welding the tab 22, making it easy for metal to accumulate in some areas of the first groove 121, resulting in uneven welding strength at the weld, leading to weld cracking and affecting the battery's service life. If the width of the first groove 121 is too small, such as a being less than 0.05 mm, the molten metal will have difficulty flowing smoothly in the first groove 121, failing to achieve a good effect of increasing the contact area between the connecting piece 1 and the tab 22. Furthermore, an excessively narrow first groove 121 will increase the processing difficulty, leading to reduced production efficiency and increased production costs.

[0057] Therefore, in this embodiment of the utility model, the width a of the first groove 121 is set in the range of 0.05mm to 0.1mm, such as 0.05mm, 0.052mm, 0.054mm, 0.056mm, 0.058mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, etc. This not only greatly increases the contact area between the tab 22 and the connecting piece 1, improving the welding quality, but also makes the processing difficulty of the first groove 121 lower, while allowing the molten metal to flow and fill better in the groove, reducing the probability of welding defects.

[0058] In some embodiments, refer to Figure 4 The distance between at least two adjacent first grooves 121 is b, where 0.05mm≤b≤0.1mm.

[0059] If the distance between two adjacent first grooves 121 is too large, making b greater than 0.1 mm, the number of first grooves 121 within a certain area will decrease, failing to effectively increase the contact area between the tab 22 and the connecting piece 1, and the effect on improving welding strength will be insignificant. If the distance between two adjacent first grooves 121 is too small, making b less than 0.05 mm, the solid portion between the two adjacent first grooves 121 will be too weak, resulting in low structural strength of the connecting piece 1, making it susceptible to damage under external forces, thereby affecting the safety performance and service life of the battery.

[0060] Therefore, in this embodiment of the utility model, the distance between at least two adjacent first grooves 121 is set between 0.05mm and 0.1mm. While ensuring the structural strength of the connecting piece 1, the distribution of the first grooves 121 on the connecting piece 1 is more reasonable. This fully utilizes the effect of the first grooves 121 in increasing the contact area between the tab 22 and the connecting piece 1, thereby improving the welding strength and connection stability between the tab 22 and the connecting piece 1, and ensuring that the manufactured battery has better safety performance.

[0061] In some embodiments, refer to Figure 5 One end of the connecting piece 1 is provided with a mounting hole 13, which is used to accommodate part of the pole post 21 and to connect the pole post 21.

[0062] When welding the electrode post 21 to the connecting piece 1, first place the electrode post 21 into the mounting hole 13 so that the electrode post 21 and the connecting piece 1 are in contact. Then, weld the electrode post 21 and the connecting piece 1 together by means of laser or ultrasonic welding. Because the electrode post 21 is accommodated in the mounting hole 13 during installation, the mounting hole 13 effectively limits the electrode post 21, reduces the probability of the electrode post 21 moving axially, and improves the stability of the welding.

[0063] The inner diameter of the mounting hole 13 is typically slightly larger than the outer diameter of the pole post 21, allowing the pole post 21 to be accommodated within the mounting hole 13. The shape of the mounting hole 13 is determined by the shape of the pole post 21. For example, if the pole post 21 is cylindrical, the mounting hole 13 is also cylindrical; if the pole post 21 is prism, the mounting hole 13 is also prism-shaped. It is understood that the mounting hole 13 can also be other shapes, as long as it can accommodate the pole post 21. The mounting hole 13 can be a through hole or a blind hole; this invention does not impose any limitations on this.

[0064] Compared to related technologies where the connecting piece 1 protrudes to connect to the terminal post 21, the connecting piece 1 only contacts the bottom surface of the terminal post 21, requiring a high degree of flatness. In this embodiment, by creating a mounting hole 13 on the connecting piece 1, the terminal post 21 can be partially accommodated within the mounting hole 13. This ensures that the side surface of the terminal post 21 is in full contact with the inner surface of the mounting hole 13, guaranteeing both the welding strength between the terminal post 21 and the connecting piece 1, and ensuring a good conductive path between them, thus reducing energy loss during battery use.

[0065] In some embodiments, refer to Figures 5 to 7 The inner wall of the mounting hole 13 is provided with a stepped surface 131, which is used to abut against the pole post 21.

[0066] By setting the stepped surface 131, the bottom surface of the electrode post 21 can abut against the stepped surface 131 when welding the electrode post 21 and the connecting piece 1, making the welding process more convenient. Furthermore, the stepped surface 131 and the electrode post 21 can also serve as a welding point, thereby improving the welding strength between the electrode post 21 and the connecting piece 1. Specifically, the stepped surface 131 can be an annular surface, allowing the mounting hole 13 to remain through, facilitating welding of the side of the connecting piece 1 away from the electrode post 21. Alternatively, the stepped surface 131 can be set as a complete plane, making the mounting hole 13 a blind hole. The specific design can be customized according to actual needs, and this invention does not impose any limitations on this.

[0067] In some embodiments, refer to Figure 8 The distance between at least one edge of the concave-convex structure 12 and the connecting piece 1 is L, 0.05mm≤L≤0.1mm.

[0068] If the distance between the concave-convex structure 12 and at least one adjacent edge of the connecting piece 1 is too large, making L greater than 0.1 mm, the larger distance will reduce the amount of concave-convex structure 12 available to increase the contact area between the tab 22 and the connecting piece 1 near the edge of the connecting piece 1. This will result in less improvement in welding strength when welding the tab 22 to the edge area of ​​the connecting piece 1, making it prone to incomplete welding. Furthermore, while the concave-convex structure 12 has a positive effect on stress dispersion, if the area covered by the concave-convex structure 12 is small, it will not effectively improve the bending resistance of the connecting piece 1, making it prone to warping. If the distance between the concave-convex structure 12 and at least one adjacent edge of the connecting piece 1 is too small, making L less than 0.05 mm, the strength of the narrow edge portion will be low, making it susceptible to damage from friction and collisions during assembly, thus affecting the normal use and lifespan of the connecting piece 1. Additionally, a smaller L requires more sophisticated processing techniques, leading to increased battery production costs and reduced production efficiency.

[0069] Therefore, in this embodiment of the utility model, the distance between the concave-convex structure 12 and at least one edge adjacent to the connecting piece 1 is set between 0.05mm and 0.1mm, for example, 0.05mm, 0.052mm, 0.054mm, 0.056mm, 0.058mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, etc. While ensuring high structural strength at the edge of the connecting piece 1, the concave-convex structure 12 can be fully utilized to increase the contact area between the tab 22 and the connecting piece 1, improve the welding strength, and thus improve the safety performance and service life of the battery.

[0070] In some embodiments, refer to Figure 8 The number of electrode welding areas 11 is at least two, and the connecting piece 1 is provided with at least one electrode welding area 11 on each side edge along the first direction H1;

[0071] Along the first direction H1, the distance from the concave-convex structure 12 to at least one edge of the connecting piece 1 is L1, where 0.05mm ≤ L1 ≤ 0.1mm. While ensuring high structural strength at the edge of the connecting piece 1, the structure also covers the electrode welding area 11 as much as possible, facilitating the full utilization of the concave-convex structure 12 to increase the contact area between the electrode 22 and the connecting piece 1, thereby improving welding strength. The specific arrangement of the concave-convex structure 12 in this embodiment is similar to that in the previous embodiments and will not be repeated here.

[0072] In some embodiments, refer to Figure 8 Along the second direction H2, the distance between the concave-convex structure 12 and at least one edge of the connecting piece 1 is L2, where 0.05mm ≤ L2 ≤ 0.1mm; the second direction H2 is perpendicular to the first direction H1. The specific arrangement of the concave-convex structure 12 in this embodiment is similar to that in the previous embodiment, and will not be repeated here.

[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 tab for connecting a pole and a tab in a battery, characterized by, The connecting piece is provided with a tab welding area for welding the tab; The connecting piece is further provided with a concave-convex structure, which is arranged on the side of the connecting piece facing the tab, and at least partially located in the tab welding area, so as to increase the contact area between the tab and the tab welding area. The concave-convex structure comprises a plurality of first grooves, and the first grooves are long strips, and at least part of the first grooves are parallel to each other.

2. The tab of claim 1, wherein The depth of the first groove is d1, and d1≤0.1mm.

3. The tab of claim 1, wherein The depth of the first groove is d1, and the thickness of the connecting piece is d2, and 0.05≤d1 / d2≤0.

07.

4. The tab of claim 2, wherein The width of the first groove is a, and 0.05mm≤a≤0.1mm.

5. The tab of claim 2, wherein The distance between at least two adjacent first grooves is b, and 0.05mm≤b≤0.1mm.

6. The tab according to any one of claims 1 to 5, characterized in that One end of the connecting piece is provided with a mounting hole, and the mounting hole is used to accommodate part of the pole to connect the pole.

7. The tab of claim 6, wherein The inner wall of the mounting hole is provided with a stepped surface for abutting with the pole.

8. The tab according to any one of claims 1 to 5, characterized in that The distance between the concave-convex structure and at least one side edge of the connecting piece is L, and 0.05mm≤L≤0.1mm.

9. The tab of claim 8, wherein, The number of the tab welding areas is at least two, and at least one tab welding area is arranged on each side edge of the connecting piece along the first direction; Along the first direction, the distance between the concave-convex structure and at least one side edge of the connecting piece is L1, and 0.05mm≤L1≤0.1mm.

10. The tab of claim 9, wherein, Along the second direction, the distance between the concave-convex structure and at least one side edge of the connecting piece is L2, and 0.05mm≤L2≤0.1mm; the second direction is perpendicular to the first direction.

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