Pole assembly, battery module and battery pack
By designing a layered structure and controlling the welding depth in the electrode assembly, the problem of copper-aluminum composite interface damage during welding was solved, thereby improving welding stability and electrical performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HUIZHOU EVE POWER CO LTD
- Filing Date
- 2025-03-19
- Publication Date
- 2026-06-02
AI Technical Summary
In existing technologies, the copper-aluminum composite interface of the composite electrode is easily damaged during cell welding, resulting in a decrease in electrical performance after welding.
The design includes a pole assembly comprising a first metal part and a second metal part stacked along a first direction, an outer connecting piece welded to the second metal part to form a first welded part, and satisfying the formula 0 < C1 - H1 ≤ 0.5H2, and controlling the welding depth to reduce the impact on the composite interface.
It reduces the risk of damage to the composite interface during welding and improves welding stability and electrical properties.
Smart Images
Figure CN224318665U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of battery technology, specifically to a terminal assembly, a battery module, and a battery pack. Background Technology
[0002] Battery modules typically consist of multiple battery cells. To electrically connect the cells, the terminals of these cells are welded together using connecting tabs. To reduce the cost of the negative terminal and improve the welding stability between the negative terminal and the terminal, a composite terminal with an aluminum upper layer and a copper lower layer is usually used, forming a copper-aluminum composite interface between the aluminum and copper layers. In related technologies, welding the connecting tabs and battery cells generates significant heat. When composite terminals are used, if the weld penetration is inappropriate, the welding heat can easily damage the copper-aluminum composite interface of the layered terminals, leading to a decrease in the electrical performance after welding. Utility Model Content
[0003] The embodiments of this application provide a terminal post assembly, a battery module, and a battery pack. The terminal post assembly can reduce the risk of damage to the composite interface in the composite terminal post during the welding of the terminal post and the external connecting piece, and ensure the electrical performance of the terminal post assembly.
[0004] In a first aspect, embodiments of this application provide a pole assembly, including a pole and an external connecting piece;
[0005] The pole includes a first metal part and a second metal part stacked along a first direction;
[0006] The outer connecting piece is stacked along the first direction on the side of the second metal part away from the first metal part, and the outer connecting piece is welded to the second metal part to form a first welded part;
[0007] The first welded part penetrates the outer connecting piece along the first direction and is partially located inside the second metal part, where 0 < C1 - H1 ≤ 0.5H2, where C1 represents the effective penetration depth of the first welded part in the first direction, H1 represents the thickness of the outer connecting piece in the first direction, and H2 represents the minimum thickness of the second metal part at the corresponding first welded part in the first direction.
[0008] In some embodiments, 0.4H2 < Cl-H1 ≤ 0.5H2.
[0009] In some embodiments, 0.3mm ≤ C1 ≤ 5mm.
[0010] In some embodiments, the effective weld width of the first weld portion in the second direction is C2, 0.3mm≤C2≤10mm; wherein the second direction is perpendicular to the first direction.
[0011] In some embodiments, the first weld portion forms a weld trajectory on the surface of the outer connecting piece away from the pole post;
[0012] Welding paths can be spiral, circular, or ring-shaped.
[0013] In some embodiments, the orthographic projection of the pole post in the first direction covers the orthographic projection of the welding trajectory in the first direction.
[0014] In some embodiments, the area of the solder mark formed on the surface of the outer connecting piece away from the pole post in the first welding portion is S = 20 mm. 2 ≤S≤1000mm 2 .
[0015] In some embodiments, the pole assembly further includes an inner connecting piece;
[0016] The inner connecting piece is stacked along the first direction on the side of the first metal part away from the second metal part, and the inner connecting piece is welded to the first metal part to form a second welded part;
[0017] The second welded part penetrates the inner connecting piece along the first direction and is partially located inside the first metal part, where 0 < C2 - H3 ≤ 0.5H4, where C2 represents the effective penetration depth of the second welded part in the first direction, H3 represents the thickness of the inner connecting piece in the first direction, and H4 represents the minimum thickness of the first metal part at the location corresponding to the second welded part in the first direction.
[0018] In some embodiments, the outer connecting piece and the second metal part are made of the same material;
[0019] And / or, the inner connecting piece is made of the same material as the first metal part.
[0020] Secondly, embodiments of this application provide a battery module including multiple battery cells;
[0021] Multiple battery cells are connected through the aforementioned terminal assembly.
[0022] Thirdly, embodiments of this application provide a battery pack including the battery module as described above.
[0023] The beneficial effects of the embodiments of this application are as follows:
[0024] In embodiments of this application, the electrode assembly includes an electrode post and an outer connecting piece. The electrode post includes a first metal member and a second metal member stacked along a first direction. The outer connecting piece is stacked along the first direction on the side of the second metal member away from the first metal member, and the outer connecting piece is welded to the second metal member to form a first welded connection. The first welded connection penetrates the outer connecting piece along the first direction and is partially located within the second metal member, where 0 < C1 - H1 ≤ 0.5H2, where C1 represents the effective penetration depth of the first welded connection in the first direction, H1 represents the thickness of the outer connecting piece in the first direction, and H2 represents the minimum thickness of the second metal member at the corresponding first welded connection in the first direction. For an electrode post composed of a first metal member and a second metal member, by having the first welded connection penetrate the outer connecting piece along the first direction and be partially located within the second metal member, the outer connecting piece and the second metal member can be welded into a single unit, thereby achieving the connection between the outer connecting piece and the electrode post. By satisfying the formula 0<C1-H1≤0.5H2, it is possible to ensure the welding of the external connecting piece and the electrode post while reducing the impact of heat during the welding process on the composite interface of the first and second metal parts in the electrode post, reducing the risk of composite interface damage, ensuring welding stability, and improving the electrical performance of the electrode post assembly after welding. Attached Figure Description
[0025] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0026] Figure 1 This is a partial structural schematic diagram of the pole assembly provided in an embodiment of this application;
[0027] Figure 2 yes Figure 1 Enlarged view of point A in the middle;
[0028] Figure 3 yes Figure 1 Enlarged view of point B in the middle;
[0029] Figure 4 This is a schematic diagram of the structure of the pole in the pole assembly provided in this application embodiment;
[0030] Figure 5 This is a top view of the pole assembly provided in the embodiments of this application.
[0031] Explanation of reference numerals in the attached figures:
[0032] 1. Pole post; 11. First metal part; 12. Second metal part; 2. Outer connecting piece; 21. Welding trajectory; 3. First welding part; 4. Inner connecting piece; 5. Second welding part. Detailed Implementation
[0033] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application. In this application, 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.
[0034] Firstly, such as Figure 1 and Figure 2 As shown, an embodiment of this application provides an electrode assembly including an electrode post 1 and an outer connecting piece 2. The electrode post 1 includes a first metal member 11 and a second metal member 12 stacked along a first direction X. The outer connecting piece 2 is stacked along the first direction X on the side of the second metal member 12 away from the first metal member 11, and the outer connecting piece 2 is welded to the second metal member 12 to form a first weld portion 3. The first weld portion 3 penetrates the outer connecting piece 2 along the first direction X and is partially located within the second metal member 12, where 0 < C1 - H1 ≤ 0.5H2, where C1 represents the effective penetration depth of the first weld portion 3 in the first direction X, H1 represents the thickness of the outer connecting piece 2 in the first direction X, and H2 represents the minimum thickness of the second metal member 12 at the corresponding first weld portion 3 in the first direction X. For the electrode post 1 composed of the first metal member 11 and the second metal member 12, by having the first weld portion 3 penetrate the outer connecting piece 2 along the first direction X and be partially located within the second metal member 12, the outer connecting piece 2 and the second metal member 12 can be welded into a whole, thereby realizing the connection between the outer connecting piece 2 and the electrode post 1. By satisfying the formula 0<C1-H1≤0.5H2, it is possible to ensure the welding of the external connecting piece 2 and the pole post 1, while reducing the impact of heat during the welding process on the composite interface of the first metal part 11 and the second metal part 12 in the pole post 1, reducing the risk of composite interface damage, ensuring welding stability, and improving the electrical performance of the pole post assembly after welding.
[0035] For example, C1-H1 can be equal to 0.1H2, 0.2H2, 0.3H2, 0.4H2 or 0.5H2.
[0036] like Figure 4As shown, the pole post 1 includes a first metal member 11 and a second metal member 12 stacked along a first direction X. The first metal member 11 has a first protrusion protruding along the first direction X, and the second metal member 12 has a first recess, with the first protrusion fitting into the first recess. Furthermore, a reverse-wrapping structure is provided on the periphery of the first metal member 11, forming a second recess between the reverse-wrapping structure and the first protrusion. The second metal member 12 has a second protrusion on its periphery, which fits into the second recess and is engaged with the first metal member 11 by the reverse-wrapping structure and the first protrusion.
[0037] That is, the first metal part 11 and the second metal part 12 are interlocked through a reverse wrapping structure, ensuring the overall structural stability. Compared with the integrated pole post 1, the pole post 1 provided in this embodiment includes the first metal part 11 and the second metal part 12 stacked together, which makes the welding process more complicated. If the effective penetration depth during the welding process is too large, it is easy to cause the composite interface to be damaged, thereby affecting the relevant performance of the pole post assembly.
[0038] It is understandable that the external connecting piece 2 is a connecting piece located outside the battery cell. When multiple battery cells form a battery module, the terminals 1 of the multiple battery cells need to be connected in series or in parallel through the external connecting piece 2.
[0039] In some embodiments, 0.4H2 < C1-H1 ≤ 0.5H2. By satisfying 0.4H2 < C1-H1 ≤ 0.5H2, the first weld portion 3 can penetrate more into the second metal part 12, thereby improving the welding stability between the outer connecting piece 2 and the pole post 1, and also reducing the risk of damage to the composite interface caused by excessive effective penetration of the first weld portion 3.
[0040] In some embodiments, 0.3mm ≤ C1 ≤ 5mm. By ensuring that the effective penetration depth of the first weld 3 is within the range of 0.3mm to 5mm, the welding strength between the outer connecting piece 2 and the pole post 1 can be guaranteed, ensuring connection stability while reducing the phenomenon that an increase in welding defects is caused by a certain effective penetration depth.
[0041] For example, C1 can be 0.3mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm.
[0042] In some embodiments, such as Figure 2As shown, the effective weld width of the first weld portion 3 in the second direction is C2, where 0.3mm ≤ C2 ≤ 10mm. The second direction is perpendicular to the first direction X. By satisfying 0.3mm ≤ C2 ≤ 10mm, a weld surface of suitable width can be formed between the outer connecting piece 2 and the pole post 1, ensuring the weld quality between them and reducing the occurrence of weld defects. For example, the effective weld width C2 of the first weld portion 3 in the second direction can be 0.3mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, or 10mm.
[0043] In some embodiments, such as Figure 5 As shown, the first welding part 3 forms a welding trajectory 21 on the surface of the outer connecting piece 2 away from the pole post 1. The welding trajectory 21 can be spiral, circular, or annular. In the actual welding process, a suitable welding trajectory 21 form can be selected according to actual needs to ensure welding stability and the flow area after welding.
[0044] To increase the flow area, a sawtooth or wavy welding trajectory can also be used 21.
[0045] It should be noted that when those skilled in the art weld the outer connecting piece 2 and the electrode post 1 to form the first welded part 3, they can set a suitable welding trajectory according to the actual situation and needs of the battery cell. For example, a spiral welding trajectory can reduce the pauses and restarts during the welding process through a continuous welding path, thereby improving welding efficiency. The continuous and smooth welding path helps reduce welding defects and ensures the welding area, thus improving welding strength. A circular welding trajectory allows the welded outer connecting piece 2 and electrode post 1 to fuse together, forming a circular welding surface that can withstand greater tensile and compressive forces. Furthermore, the circular welding trajectory can reduce stress concentration. A circular welding trajectory is suitable for welding circular workpieces. For example, for a cylindrical electrode post, using a circular welding trajectory allows for uniform and stable welding of the outer connecting piece 2 and the electrode post 1, thereby ensuring post-weld stability.
[0046] In some embodiments, the orthographic projection of the electrode post 1 in the first direction X overlaps with the orthographic projection of the welding trajectory 21 in the first direction X. That is, the orthographic projection of the welding trajectory 21 in the first direction X falls within the range of the orthographic projection of the electrode post 1 in the first direction X, ensuring the welding quality of the outer connecting piece 2 and the electrode post 1 and reducing the impact of heat generated during the welding process on the peripheral components of the electrode post 1. For example, to keep the electrode post 1 insulated from other components in the top cover, an insulating element is typically provided around the periphery of the electrode post 1. By controlling the range of the welding trajectory 21, the impact on the insulating element can be reduced.
[0047] In some embodiments, the area of the solder mark formed on the surface of the outer connecting piece 2 away from the pole post 1 by the first welding part 3 is S = 20 mm. 2 ≤S≤1000mm 2 By ensuring the solder area is within the aforementioned range, sufficient welding surface can be formed between the external connector 2 and the terminal 1, guaranteeing welding quality. Furthermore, when the solder area is within the aforementioned range, the current-carrying area between the terminal 1 and the external connector 2 can also be guaranteed, improving electrical performance.
[0048] For example, the area S of the solder mark can be 20 mm. 2 50mm 2 100mm 2 150mm 2 200mm 2 250mm 2 300mm 2 350mm 2 400mm 2 450mm 2 500mm 2 550mm 2 600mm 2 650mm 2 700mm 2 750mm 2 800mm 2 850mm 2 900mm 2 950mm 2 Or 1000mm 2 .
[0049] In some embodiments, such as Figure 1 and Figure 3As shown, the pole assembly also includes an inner connecting piece 4. The inner connecting piece 4 is stacked along the first direction X on the side of the first metal part 11 away from the second metal part 12, and the inner connecting piece 4 is welded to the first metal part 11 to form a second welded part 5. The second welded part 5 penetrates the inner connecting piece 4 along the first direction X and is partially located inside the first metal part 11, where 0 < C2 - H3 ≤ 0.5H4, where C2 represents the effective penetration depth of the second welded part 5 in the first direction X, H3 represents the thickness of the inner connecting piece 4 in the first direction X, and H4 represents the minimum thickness of the first metal part 11 at the location corresponding to the second welded part 5 in the first direction X.
[0050] Similar to the outer connecting piece 2, the inner connecting piece 4 is welded to the first metal part 11 through the second welding part 5. By satisfying the formula 0<C2-H3≤0.5H4, the welding heat can be reduced on the composite interface between the first metal part 11 and the second metal part 12 while ensuring the welding of the inner connecting piece 4 to the pole 1. This reduces the risk of composite interface damage, ensures welding stability, and improves the electrical performance of the pole assembly after welding.
[0051] In addition, in order to ensure the welding stability of the inner connecting piece 4 and the first metal part 11 and reduce welding defects, the second welding part 5 is provided in the area of the first metal part 11 with the first protrusion, thereby improving the effective penetration of the second welding part 5 to a certain extent and reducing the influence of welding heat on the composite interface between the first metal part 11 and the second metal part 12, and reducing the phenomenon of the composite interface being damaged.
[0052] Understandably, the inner connecting piece 4 is a connecting piece located inside the battery cell, which is usually used to connect the terminal 1 and the tab.
[0053] In some embodiments, the effective weld width of the second weld portion 5 in the second direction Y is 0.3mm-10mm.
[0054] Similar to the first welding part 3, the effective weld width of the second welding part 5 in the second direction Y is set within the range of 0.3mm-10mm. This allows a welding surface of suitable width to be formed between the inner connecting piece 4 and the pole post 1, ensuring the welding quality between the two and reducing the occurrence of welding defects. For example, the effective weld width of the second welding part 5 in the second direction Y can be 0.3mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, or 10mm.
[0055] In some embodiments, the outer connecting piece 2 and the second metal part 12 are made of the same material. For example, both the outer connecting piece 2 and the second metal part 12 are made of aluminum. By making the outer connecting piece 2 and the second metal part 12 of the same material, the welding quality of the outer connecting piece 2 and the second metal part 12 can be guaranteed.
[0056] In some embodiments, the inner connecting piece 4 and the first metal part 11 are made of the same material. For example, both the inner connecting piece 4 and the second metal part 12 are made of copper. By making the inner connecting piece 4 and the second metal part 12 of the same material, the welding quality of the inner connecting piece 4 and the second metal part 12 can be guaranteed.
[0057] Secondly, embodiments of this application provide a battery module including multiple battery cells. The multiple battery cells are connected via the aforementioned terminal assembly.
[0058] The battery module provided in this application embodiment has all the beneficial effects of the terminal assembly as described above, which will not be repeated here.
[0059] Thirdly, embodiments of this application provide a battery pack including the battery module as described above.
[0060] The battery pack provided in this application embodiment has all the beneficial effects of the terminal assembly described above, which will not be repeated here.
[0061] The effective penetration depth of the first weld portion 3 and the second weld portion 5 can be controlled by adjusting the power during the welding process. For example, when laser welding is used, the effective penetration depth can be controlled by changing the power of the laser.
[0062] The embodiments of this application are further illustrated below with reference to specific examples. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of this application. Experimental methods in the following embodiments that do not specify specific conditions are generally performed according to the conditions recommended by the manufacturer.
[0063] Example 1
[0064] The outer connecting piece 2 is welded to the pole post 1 by laser welding to form a pole post assembly. Laser welding is used, and during the welding process, the laser power is set to 1200W, ensuring that the effective penetration depth C1 of the first welded part 3 in the first direction X, the thickness H1 of the outer connecting piece 2 in the first direction X, and the minimum thickness H2 of the first metal part 11 at the first welded part 3 in the first direction X satisfy C1-H1=0.1H2.
[0065] Example 2
[0066] The difference between this embodiment and Embodiment 1 is that the power of the laser is 1500W and C1-H1=0.21H2.
[0067] Example 3
[0068] The difference between this embodiment and Embodiment 1 is that the power of the laser is 1800W and C1-H1=0.29H2.
[0069] Example 4
[0070] The difference between this embodiment and Embodiment 1 is that the power of the laser is 2100W and C1-H1=0.37H2.
[0071] Example 5
[0072] The difference between this embodiment and Embodiment 1 is that the power of the laser is 2400W and C1-H1=0.45H2.
[0073] Example 6
[0074] The difference between this embodiment and Embodiment 1 is that the power of the laser is 2700W and C1-H1=0.52H2.
[0075] Comparative Example 1
[0076] The difference between this comparative example and Example 1 is that the power of the laser is 3700W and C1-H1=0.58H2.
[0077] By testing the composite interfaces of the electrode assembly in Examples 1-6 and Comparative Example 1, it was found that the composite interfaces between the first metal part 11 and the second metal part 12 in Examples 1-6 were not damaged, while the composite interface between the first metal part 11 and the second metal part 12 in Comparative Example 1 showed signs of damage. This indicates that by ensuring that the effective penetration depth C1 of the first welded portion 3 in the first direction X, the thickness H1 of the outer connecting piece 2 in the first direction X, and the minimum thickness H2 of the first metal part 11 at the first welded portion 3 in the first direction X satisfy 0 < C1 - H1 ≤ 0.5H2, the risk of damage to the interface between the outer connecting piece 2 and the second metal part 12 in the electrode 1 caused by welding heat can be reduced while ensuring the welding of the outer connecting piece 2 to the electrode 1. This ensures welding stability and improves the electrical performance of the electrode assembly after welding.
[0078] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. 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 application. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A pole assembly, characterized in that, Includes poles and external connectors; The pole includes a first metal component and a second metal component stacked along a first direction; The outer connecting piece is stacked along the first direction on the side of the second metal part away from the first metal part, and the outer connecting piece is welded to the second metal part to form a first welded part; The first welded portion penetrates the outer connecting piece along the first direction and is partially located within the second metal part, where 0 < C1 - H1 ≤ 0.5H2, where C1 represents the effective penetration depth of the first welded portion in the first direction, H1 represents the thickness of the outer connecting piece in the first direction, and H2 represents the minimum thickness of the second metal part in the first direction corresponding to the first welded portion.
2. The pole assembly according to claim 1, characterized in that, 0.4 H2 < Cl-H1 ≤ 0.5 H2.
3. The pole assembly according to claim 2, characterized in that, 0.3mm≤C1≤5mm.
4. The pole assembly according to claim 3, characterized in that, The effective weld width of the first welded part in the second direction is C2, 0.3mm≤C2≤10mm; wherein the second direction is perpendicular to the first direction.
5. The pole assembly according to claim 3, characterized in that, The first welding part forms a welding trajectory on the surface of the outer connecting piece away from the pole post; The welding trajectory includes spiral, circular, or annular shapes.
6. The electrode assembly according to claim 5, characterized in that, The orthographic projection of the pole post in the first direction covers the orthographic projection of the welding trajectory in the first direction.
7. The pole assembly according to claim 6, characterized in that, The first welding portion forms a weld mark on a side surface of the outer connecting tab distal from the pole, and the area of the weld mark is S, 20mm 2 ≤ S ≤ 1000mm 2 .
8. The pole assembly according to claim 7, characterized in that, It also includes internal connecting pieces; The inner connecting piece is stacked along the first direction on the side of the first metal part away from the second metal part, and the inner connecting piece is welded to the first metal part to form a second welded part; The second welded portion penetrates the inner connecting piece along the first direction and is partially located within the first metal part, where 0 < C2 - H3 ≤ 0.5H4, where C2 represents the effective penetration depth of the second welded portion in the first direction, H3 represents the thickness of the inner connecting piece in the first direction, and H4 represents the minimum thickness of the first metal part at the corresponding second welded portion in the first direction.
9. The pole assembly according to claim 8, characterized in that, The external connecting piece and the second metal part are made of the same material; And / or, the inner connecting piece is made of the same material as the first metal part.
10. A battery module, characterized in that, Includes multiple battery cells; The plurality of said battery cells are connected by the terminal assembly according to any one of claims 1-9.
11. A battery pack, characterized in that, Includes the battery module as described in claim 10.