Battery tab structure, pole piece and battery
By setting welding grooves on the surface of the battery ear structure, the problem of welding printing protrusions during welding is solved, which reduces safety risks and improves the flatness of the battery cell.
Patent Information
- Application Number
- CN202323642116.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-29
- Publication Date
- 2025-02-14
- Estimated Expiration
- 2033-12-29
AI Technical Summary
The existing battery cell winding structure is prone to form protruding welding printing during welding, resulting in safety risks and flatness problems.
Design a battery electrode ear structure with a welding groove on the surface, the depth of the welding groove is not less than 0.01mm and not more than 65% of the thickness of the electrode ear structure to fully accommodate the welding head and make the welding print located inside the groove , avoid welding printing protrusion.
It effectively reduces the height of the soldering protruding electrode plane, reduces the safety risk of the electrode structure, and improves the flatness of the battery cell.
Smart Images
Figure CN222483627U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of batteries, and in particular relates to a battery ear structure, a pole piece and a battery. Background Art
[0002] The existing battery cell winding structure usually adopts ultrasonic welding technology, which uses a high-frequency vibration welding head to apply energy to the tab metal strip and the current collector between the fixed welding seat to achieve the fusion between the molecular layers at the interface. However, since the welding area generated on the flat surface of the tab metal strip will form a weld mark protruding from the tab metal strip, on the one hand, the leakage of the weld mark will pose a certain safety risk, and on the other hand, the leakage of the weld mark will affect the flatness of the subsequent battery cell. It can be seen that making the tab structure have sufficient safety and flatness has become one of the difficulties in battery structure design. For this reason, it is urgent to propose a new technical solution to solve the above problems. Utility Model Content
[0003] One of the purposes of the utility model is to address the deficiencies of the prior art and provide a battery tab structure, which can effectively reduce the thickness of the tab metal strip on the welding operation surface, make the welding surface lower than the metal strip plane, reduce the height of the weld mark protruding from the tab plane, and reduce the safety risk of the tab structure.
[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0005] A battery tab structure, wherein a welding groove is provided on the surface of the tab structure, wherein the depth of the welding groove is not less than 0.01 mm, and the depth of the welding groove is not greater than 65% of the thickness of the tab structure, wherein the welding groove is used to completely accommodate the entire welding head, so that the entire weld mark is located inside the welding groove, so that the welding groove plays a role of burying the weld mark, and avoids the weld mark protruding from the tab plane.
[0006] As an improvement of the tab structure of the battery of the utility model, the tab structure has a plurality of welding grooves arranged at intervals, and the periphery of each welding groove is provided with a rounded corner.
[0007] As an improvement of the tab structure of the battery of the utility model, the length of the tab structure is L1, and the length of the welding groove is L2, which satisfies the relationship: 0.15≤L2 / L1≤0.3.
[0008] As an improvement of the tab structure of the battery of the utility model, the tab structure has a welding groove in the shape of a long groove, and the connection between the long side and the short side of the welding groove has a rounded corner.
[0009] As an improvement of the tab structure of the battery of the utility model, the length of the tab structure is L1, and the length of the long groove-shaped welding groove is L2, satisfying the relationship: 0.45≤L2 / L1≤0.75.
[0010] As an improvement of the tab structure of the battery of the utility model, the depth of the welding groove is 50.01% to 60% of the thickness of the tab structure.
[0011] As an improvement to the tab structure of the battery of the utility model, the bottom wall of the welding groove has a welding mark, and a protective layer covering the welding mark is arranged in the groove space enclosed by the welding groove, and the protective layer is hidden in the groove space.
[0012] As an improvement of the battery tab structure of the utility model, the notch of the welding groove is smoothly transitionally connected to the surface of the tab structure to prevent structural defects such as burrs on the notch of the welding groove from damaging the battery structure.
[0013] As an improvement of the tab structure of the battery of the utility model, the width of the tab structure is W, and the width of the welding groove is W1, which satisfies the relationship: 0.55≤W1 / W≤0.85.
[0014] The second object of the utility model is to provide a pole piece, comprising a metal foil and a pole ear structure, wherein the welding groove is located on a side of the pole ear structure away from the metal foil, and the pole ear structure is welded to the surface of the metal foil.
[0015] Preferably, the welding groove corresponds to the welding area of the metal foil along the thickness direction of the metal foil.
[0016] The third object of the present utility model is to provide a battery, comprising the pole piece as described above.
[0017] The beneficial effect of the utility model is that: the surface of the pole lug structure of the battery of the utility model is provided with a welding groove, the depth of the welding groove is not less than 0.01 mm, and the depth of the welding groove is not greater than 65% of the thickness of the pole lug structure, wherein the welding groove not only plays the role of burying the weld mark, but also thins the partial thickness of the pole lug area in the welding operation surface, so that the welding surface is lower than the plane of the pole lug structure, and reduces the height of the weld mark protruding from the pole lug plane, thereby effectively reducing the safety risk of the pole lug structure. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a side view of embodiment 1 of the present utility model.
[0019] Figure 2It is another visual structural schematic diagram of embodiment 1 of the utility model.
[0020] Figure 3 It is a side view of embodiment 2 of the present utility model.
[0021] Figure 4 This is another visual structural schematic diagram of Example 2 of the present utility model.
[0022] Figure 5 It is a side view of embodiment 4 of the present utility model.
[0023] Figure 6 This is another visual structural schematic diagram of Example 4 of the utility model.
[0024] Figure 7 It is a side view of embodiment 5 of the present utility model.
[0025] Figure 8 This is another visual structural schematic diagram of Example 5 of the utility model.
[0026] Among them: 1. Ear structure; 2. Welding groove; 3. Guide fillet; 4. Welding mark; 5. Metal foil; L1, length of welding groove; L2, length of welding area; T1, thickness direction of metal foil. DETAILED DESCRIPTION
[0027] If certain words are used in the specification and claims to refer to specific components, those skilled in the art should understand that manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. As mentioned throughout the specification and claims, "including" is an open term and should be interpreted as "including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve technical problems within a certain error range and basically achieve technical effects.
[0028] In the utility model, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the utility model can be understood according to the specific circumstances.
[0029] In the prior art, the tab and the current collector can be welded by ultrasonic welding technology using the heat generated by the high-speed friction between the welding head and the tab under ultrasonic vibration. However, the inventors found that the safety performance of the existing tab structure is insufficient, and structural defects are often prone to occur at the welding of the tab of the battery cell. For example, the leakage of welding marks will pose certain safety risks and affect the flatness of the subsequent battery cell. Therefore, it is necessary to optimize the design of the tab structure.
[0030] The following is combined with Figures 1 to 8 The utility model is further described in detail with specific embodiments, but is not intended to limit the utility model.
[0031] Example 1
[0032] A battery tab structure, see Figure 1 and Figure 2 A plurality of welding grooves 2 are provided on the surface of the pole lug structure 1, the depth of each welding groove 2 is not less than 0.01 mm, and the depth of each welding groove 2 is not greater than 65% of the thickness of the pole lug structure 1. By opening a welding groove 2 of appropriate depth on one side of the pole lug structure 1, the welding surface can be made lower than the plane of the pole lug structure 1, thereby reducing the height of the weld mark protruding from the pole lug plane.
[0033] Preferably, a plurality of welding grooves 2 are arranged at equal intervals or equiproportionate intervals on one side of the tab structure 1 , and at the same time, a rounded corner 3 is provided on the periphery of each welding groove 2 to effectively eliminate edge burrs of the welding groove 2 .
[0034] Preferably, the length of the tab structure 1 is L1, and the length of the welding groove 2 is L2, satisfying the relationship: 0.15≤L2 / L1≤0.18, 0.18≤L2 / L1≤0.21, 0.21≤L2 / L1≤0.24, 0.24≤L2 / L1≤0.27 or 0.27≤L2 / L1≤0.3.
[0035] The tab structure 1 is a metal strip, and the metal strip may be made of materials such as aluminum, nickel, and copper-plated nickel that can be used for electron extraction.
[0036] Preferably, the depth of the welding groove 2 is 50.01% to 60% of the thickness of the pole ear structure 1. If the depth of the welding groove 2 is too shallow, the effect of reducing the leakage of the weld mark cannot be achieved. If the depth of the welding groove 2 is too deep, the welding surface will be too thin, affecting the welding stability. Therefore, the depth of the welding groove 2 can be 50.01% to 52%, 52% to 54%, 54% to 56%, 56% to 58% or 58% to 60% of the thickness of the pole ear structure 1, wherein the thickness of the pole ear structure 1 can be 0.8mm to 1.5mm, 1.5mm to 2.5mm, 2.5mm to 3.5mm, 3.5mm to 4.5mm, 4.5mm to 5mm, and the height of the weld mark is less than the depth of the welding groove 2.
[0037] Example 2
[0038] Different from Example 1, see Figure 3 and Figure 4 The welding groove 2 arranged on the surface of the pole ear structure 1 is in the shape of a long groove, and the connection between the long side and the short side of the welding groove 2 has a rounded corner 3. The depth of the long groove-shaped welding groove 2 is not less than 0.01 mm, and the depth of the long groove-shaped welding groove 2 is not greater than 65% of the thickness of the pole ear structure 1.
[0039] Preferably, the length of the pole ear structure 1 is L1, and the length of the long groove-shaped welding groove 2 is L2, satisfying the relationship: 0.45≤L2 / L1≤0.55, 0.55≤L2 / L1≤0.6, 0.6≤L2 / L1≤0.65, 0.65≤L2 / L1≤0.7 or 0.7≤L2 / L1≤0.75.
[0040] The other structures of this embodiment are the same as those of Embodiment 1 and will not be described again here.
[0041] Example 3
[0042] Different from the embodiment 1 or 2, the bottom wall of the welding groove 2 has a welding mark 4, and a protective layer covering the welding mark 4 is provided in the groove space enclosed by the welding groove 2, and the protective layer is hidden in the groove space. Among them, the protective layer can be a protective glue, and the protective glue is contained in the groove space of the welding groove 2, which not only ensures the safety of the tab structure 1, effectively reduces the risk of short circuit, but also can improve the flatness of the subsequent winding core to a certain extent.
[0043] In addition, the protective tape can effectively reduce the risk of the weld mark piercing the diaphragm. However, the existing method of attaching the protective tape to the surface of the tab will increase the thickness of the battery cell in the thickness direction. The protective tape will form a height difference in the local area of the battery cell, affecting the flatness of the battery cell, reducing the flatness of the battery cell and affecting the energy density. This solution can not only accommodate the protective tape in the groove space of the welding groove 2, but also reduce the height of the weld mark leaking out of the tab metal strip plane to achieve the purpose of thinning the tab tape. A groove with a certain thickness difference can even eliminate a layer of tape.
[0044] Specifically, the shape of the weld mark area is not limited to rectangular, circular, polygonal and the like, and the area of the welding groove 2 needs to be larger than the welding area, thus ensuring that the tab structure 1 has sufficient welding operation surface so that the weld mark 4 falls completely within the groove area.
[0045] The other structures of this embodiment are the same as those of Embodiment 1 or 2 and will not be described again here.
[0046] Example 4
[0047] A pole piece, see Figure 5 and Figure 6 , including a metal foil 5 and a pole ear structure 1 of Example 1 or 3, wherein each welding groove 2 in Example 1 or 3 is located on a side of the pole ear structure 1 away from the metal foil 5, the pole ear structure 1 is welded to the surface of the metal foil 5, and the welding groove 2 corresponds to the welding area of the metal foil 5 along the thickness direction T1 of the metal foil 5, wherein the area of the pole ear structure 1 without the welding groove 2 is partially exposed to the metal foil 5.
[0048] Example 5
[0049] A pole piece, see Figure 7 and Figure 8 , including a metal foil 5 and a pole ear structure 1 of Example 2 or 3, wherein the long groove-shaped welding groove 2 in Example 2 or 3 is located on a side of the pole ear structure 1 away from the metal foil 5, the pole ear structure 1 is welded to the surface of the metal foil 5, and the welding groove 2 corresponds to the welding area of the metal foil 5 along the thickness direction T1 of the metal foil 5, wherein the area of the pole ear structure 1 where the welding groove 2 is not provided is partially exposed to the metal foil 5.
[0050] By pre-opening a groove for welding on the pole tab metal strip, the generating surface of the welding burr is transferred from the surface of the pole tab metal strip to the bottom of the groove, which can reduce the height of the welding burr, reduce the risk of the pole tab protective tape being punctured by the welding burr and causing internal short circuit of the battery, and improve the safety of the battery cell; and, since the height of the welding burr protruding from the surface of the pole tab metal strip is reduced, the thickness of the pole tab protective tape and the diaphragm can also be reduced accordingly, the flatness of the battery cell structure is improved, and the energy density of the battery cell is effectively improved.
[0051] Example 6
[0052] A battery, comprising the pole piece of Example 4 or 5, wherein the battery can be a lithium ion battery, a sodium ion battery, a magnesium ion battery, etc.
[0053] Obviously, the utility model can effectively prevent structural defects from occurring at the welding points of the battery cell pole tabs, and effectively reduce the safety risks posed by the welding points of the battery cell pole tabs to the battery.
[0054] According to the disclosure and teaching of the above description, those skilled in the art to which the utility model belongs can also change and modify the above implementation. Therefore, the utility model is not limited to the above specific implementation, and any obvious improvement, replacement or modification made by those skilled in the art on the basis of the utility model belongs to the protection scope of the utility model. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the utility model.
Claims
1. A battery tab structure, characterized in that: A welding groove (2) is provided on the surface of the pole lug structure (1); the depth of the welding groove (2) is not less than 0.01 mm, and the depth of the welding groove (2) is not greater than 65% of the thickness of the pole lug structure (1).
2. The battery tab structure according to claim 1, characterized in that: The pole lug structure (1) has a plurality of welding grooves (2) arranged at intervals, and the periphery of each welding groove (2) is provided with a rounded corner (3).
3. The battery tab structure according to claim 2, characterized in that: The length of the tab structure (1) is L1, and the length of the welding groove (2) is L2, satisfying the relationship: 0.15≤L2 / L1≤0.
3.
4. The battery tab structure according to claim 1, characterized in that: The pole ear structure (1) has a welding groove (2) in the shape of a long groove, and the connection between the long side and the short side of the welding groove (2) has a rounded corner (3).
5. The battery tab structure according to claim 4, characterized in that: The length of the pole ear structure (1) is L1, and the length of the welding groove (2) is L2, satisfying the relationship: 0.45≤L2 / L1≤0.
75.
6. The battery tab structure according to any one of claims 1 to 5, characterized in that: The depth of the welding groove (2) is 50.01% to 60% of the thickness of the tab structure (1).
7. The battery tab structure according to any one of claims 1 to 5, characterized in that: The bottom wall of the welding groove (2) has a welding mark (4), and a protective layer covering the welding mark (4) is arranged in the groove space enclosed by the welding groove (2), and the protective layer is hidden in the groove space.
8. A pole piece, characterized in that: It comprises a metal foil (5) and the tab structure (1) as claimed in any one of claims 1 to 7, wherein the welding groove (2) is located on a side of the tab structure (1) away from the metal foil (5), and the tab structure (1) is welded to the surface of the metal foil (5).
9. The pole piece according to claim 8, characterized in that: The welding groove (2) corresponds to the welding area of the metal foil (5) along the thickness direction of the metal foil (5).
10. A battery, characterized in that: Comprising the pole piece as claimed in any one of claims 8 to 9.