A secondary battery tab connection structure
By combining a conductive adhesive coating on the foil tab with a welded connection, the problem of abnormal welding of the foil tab in secondary batteries is solved, achieving a highly reliable and safe secondary battery connection structure and simplifying the operation process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN JANAENERGY TECH CO LTD
- Filing Date
- 2025-06-26
- Publication Date
- 2026-07-07
AI Technical Summary
Traditional secondary batteries are prone to problems such as incomplete welding, weld breakage, and weld cracking during the foil tab welding process, which leads to increased cell impedance, increased temperature, and reduced reliability and safety. In particular, foil tab breakage in the stacked structure will affect the cell energy density and safety.
A conductive adhesive coating is used to bond the foil tabs together with a welding connection. The conductive adhesive connection and the welding connection are used to achieve a reliable connection between the foil tabs and the tab sheet, ensuring the electronic transmission effect and avoiding welding abnormalities.
It improves the reliability and safety of secondary batteries, reduces the proportion of welding abnormalities, ensures that the battery cell can still charge and discharge normally when the foil tab breaks, avoids the risk of local impedance increase and short circuit of the battery cell, and improves the ease of operation.
Smart Images
Figure CN224472650U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of secondary battery technology, specifically to a secondary battery tab connection structure. Background Technology
[0002] Due to their outstanding performance and advantages in use, rechargeable batteries have become the mainstream direction in the era of electrification. During the design process of rechargeable batteries, multiple foil tabs are typically incorporated to enhance the high-rate charge and discharge capabilities of the cells and reduce impedance during the charging and discharging process.
[0003] Traditional wound batteries use an intermittent coating method, and the required foil tabs are intermittently cut during the slitting process. There are usually various designs such as full tabs or half full tabs, which improve the high-rate charging and discharging capability of the cell by increasing the number of tabs.
[0004] In the case of stacked batteries, the stacking method is equivalent to connecting dozens of small batteries in parallel, which greatly reduces the ohmic impedance of the battery from a structural perspective. The stacking structure also dictates that each electrode must have at least one foil tab. During the welding process, the foil tabs of the main body of the cell are welded to the tabs made of materials such as aluminum sheets, copper-plated nickel sheets, or nickel sheets using laser welding or other methods.
[0005] Whether it is a traditional wound battery or a stacked battery, they all have a multi-foil tab structure. However, when there are too many foil tabs, they often encounter many welding problems during the laser welding process, such as poor welding, weld breakage, and weld cracking, which can easily cause the foil tabs to be damaged or broken.
[0006] Under normal circumstances, for traditional wound structures, if one layer of the foil tab breaks, the impact is relatively small, and the battery can still be used normally without special requirements, only affecting the ohmic impedance or charge / discharge temperature of the cell. However, for laminated structures, if one layer of the foil tab breaks, it will directly cause that layer of electrode to fail, directly affecting the energy density and even the safety of the cell.
[0007] In addition, in extreme cases, if the broken foil tab is bent or flipped, it may cause a short circuit inside the cell, affecting battery safety.
[0008] Therefore, the laser welding process during battery cell manufacturing requires high precision to minimize the risk of tab breakage or damage. Furthermore, if the tabs are broken, cracked, or poorly welded during the welding process, it will increase the local impedance of the battery cell, leading to excessively high local temperatures during charging and discharging, thus affecting battery reliability and lifespan. Utility Model Content
[0009] The purpose of this invention is to provide a secondary battery tab connection structure that features high reliability, good safety, and smooth operation.
[0010] This utility model can be achieved through the following technical solutions:
[0011] The present invention relates to a secondary battery tab connection structure, comprising an electrode plate and a tab plate. The electrode plate is electrically connected to the tab plate via a foil tab. The end of the foil tab is provided with a conductive adhesive coating to form a conductive adhesive connection portion that adheres to and connects with the electrode plate. The exposed area adjacent to the conductive adhesive coating of the foil tab forms a welding connection portion that is welded to the electrode plate. The foil tab and the electrode plate are electrically connected through the conductive adhesive connection portion and the welding connection portion.
[0012] In this invention, the two connection methods not only ensure effective electronic transmission, but also avoid cell problems caused by broken or poorly soldered connections, thus ensuring the safety and reliability of the secondary battery.
[0013] Furthermore, the area of the conductive adhesive coating is smaller than the area of the foil tab, and the conductive adhesive coating is located outside the electrode active material layer.
[0014] Furthermore, the electrode sheet includes an anode electrode sheet and a cathode electrode sheet, with the anode electrode sheet being formed by stacking or winding the cathode electrode sheets alternately.
[0015] Furthermore, the material of the foil tab is the same as the current collector material of the electrode plate, which is aluminum foil, copper foil, aluminum mesh, copper mesh or stainless steel foil.
[0016] Furthermore, the conductive adhesive coating has a width of 2-8 mm and a thickness of 0.3-10 μm. If the conductive adhesive coating is too narrow, it will not provide effective physical adhesion; if the coating is too wide, it will affect the connection at the laser welding point. Similarly, if the conductive adhesive coating is too thin, it will not provide effective physical adhesion; if the coating is too thick, its thickness may affect the cold pressing of the electrode and cause the conductive adhesive to overflow, affecting the bonding and welding effect.
[0017] Furthermore, the conductive adhesive coating is a gold conductive adhesive coating, a silver conductive adhesive coating, a copper conductive adhesive coating, a carbon-based conductive adhesive coating, or a carbon nanotube conductive adhesive coating.
[0018] Furthermore, the secondary battery is a lithium-ion battery or a sodium-ion battery.
[0019] Furthermore, the lithium-ion battery can be a ternary material battery, a lithium iron phosphate battery, a lithium manganese oxide battery, or a lithium cobalt oxide battery.
[0020] Furthermore, the sodium-ion battery is a polyanion sodium-ion battery, a Prussian blue sodium-ion battery, or a layered oxide sodium-ion battery.
[0021] Furthermore, the conductive adhesive coating is applied to the surface of the foil tab by spraying, rolling, pressing, or scraping.
[0022] This utility model discloses a secondary battery tab connection structure, which has the following beneficial effects:
[0023] First, it has high reliability. This utility model has a conductive adhesive connection part and a welding connection part respectively set on the foil electrode tab. It adopts two connection methods at the same time, which can ensure the effective connection effect between the foil electrode tab and the electrode tabs made of aluminum sheet, copper-plated nickel sheet or nickel sheet, etc., and ensure that the foil electrode tab is not affected by welding power during welding, which can effectively reduce the proportion of foil electrode tab welding abnormalities.
[0024] Secondly, it has good safety and is easy to operate. The conductive adhesive coating used in this invention is physically bonded, which can ensure that even if the foil tab breaks at the welding position, there is still a good electronic path. It can avoid problems such as increased ohmic impedance of the cell, decreased energy density, and short circuit of the cell caused by broken or poor welding, thus ensuring the safety and reliability of the secondary battery.
[0025] Third, it is easy to operate. The connection structure of this utility model first adheres to the positioning and then welds to fix it during operation, which simplifies the operation and improves the ease of operation. Attached Figure Description
[0026] Appendix Figure 1 This is a schematic diagram of the structure of a secondary battery tab connection structure according to the present invention;
[0027] Figure 2 This is a schematic diagram of the conductive adhesive coating structure;
[0028] Figure 3 This is a schematic diagram of the conventional foil tab welding structure for secondary batteries in the prior art;
[0029] Figure 4 The charge / discharge curves of the abnormal battery cell;
[0030] The markings in the diagram include: 101 / 301, cathode electrode; 102 / 302, anode electrode; 103, conductive adhesive coating; 104 / 303, tab; 105, current collector; 106, electrode material layer. Detailed Implementation
[0031] To enable those skilled in the art to better understand the technical solution of this utility model, the product of this utility model will be further described in detail below with reference to embodiments.
[0032] Taking the anode electrode as an example, this utility model will be specifically described, such as... Figure 1-2As shown, the secondary battery tab connection structure of this utility model includes an anode electrode 102 and a tab 104. The anode electrode 102 is electrically connected to the tab 104 through a foil tab. The end of the foil tab is provided with a conductive adhesive coating 103 to form a conductive adhesive connection part that adheres to and connects with the electrode electrode. The exposed area adjacent to the conductive adhesive coating of the foil tab forms a welding connection part that is welded to the electrode electrode. The foil tab and the anode electrode 102 are electrically connected through the conductive adhesive connection part and the welding connection part.
[0033] like Figure 2 As shown, in this invention, to ensure the wettability of the two connection methods, the area of the conductive adhesive coating 102 is smaller than the area of the foil tab, and the conductive adhesive coating 103 is located outside the electrode active material layer 106.
[0034] Of course, the positions of the cathode electrode 101 and the anode electrode 102 can be interchanged, and the cathode electrode 101 can be reused in a similar manner to the anode electrode 102 to be electrically connected to the tab 104.
[0035] like Figure 1-2 As shown, the electrode sheet includes an anode electrode 102 and a cathode electrode 101. The anode electrode is formed by stacking or winding the cathode electrode sheets alternately.
[0036] Furthermore, the material of the foil tab is the same as the current collector material of the electrode plate, which is aluminum foil, copper foil, aluminum mesh, copper mesh or stainless steel foil.
[0037] Furthermore, the conductive adhesive coating has a width of 2-8 mm and a thickness of 0.3-10 μm.
[0038] Furthermore, the conductive adhesive coating is a gold conductive adhesive coating, a silver conductive adhesive coating, a copper conductive adhesive coating, a carbon-based conductive adhesive coating, or a carbon nanotube conductive adhesive coating.
[0039] Furthermore, the secondary battery is a lithium-ion battery or a sodium-ion battery.
[0040] Furthermore, the lithium-ion battery can be a ternary material battery, a lithium iron phosphate battery, a lithium manganese oxide battery, or a lithium cobalt oxide battery.
[0041] Furthermore, the sodium-ion battery is a polyanion sodium-ion battery, a Prussian blue sodium-ion battery, or a layered oxide sodium-ion battery.
[0042] Furthermore, the conductive adhesive coating is applied to the surface of the foil tab by spraying, rolling, pressing, or scraping.
[0043] Example 1
[0044] This embodiment provides a novel auxiliary connection structure for foil tabs. This novel tab connection structure includes two parts: a conductive adhesive bonding part at the end of the foil tab and a welding connection part in the middle of the foil tab. The conductive adhesive bonding part of the foil tab has a conductive adhesive coating width of 2mm, a conductive adhesive coating thickness of 0.3μm, and uses gold conductive adhesive. In the coating process, the conductive adhesive is applied to the pre-reserved empty foil portion of the foil tab according to the designed width and thickness. Before welding, a hot-pressing device is used to connect the conductive adhesive bonding parts of the foil tab using a hot-pressing adhesive bonder. Then, a conventional anode and cathode welding machine is used to weld the uncoated parts.
[0045] Example 2
[0046] Except for adjusting the width of the conductive adhesive coating to 8mm and the thickness of the conductive adhesive coating to 10μm, everything else is the same as in Example 1.
[0047] Comparative Example 1
[0048] Comparative Example 1 provides a conventional foil tab welding method for secondary batteries, and its structural schematic diagram is shown below. Figure 3 As shown, a welding machine is used to weld foil tabs to tabs made of materials such as aluminum sheets, nickel-plated copper sheets, or nickel sheets.
[0049] Examples 1, 2, and Comparative Example 1 all feature a stacked structure and are all welded with the same aluminum and nickel tabs, resulting in 200 bare cells after welding. The proportion of foil tab welding abnormalities (including incomplete welds, weld breaks, weld cracks, etc.) is statistically analyzed, and the results are shown in Table 1.
[0050] Table 1. Statistics on the number of bare cells after welding
[0051] plan Number of bare cells after welding The number of defective foil tabs (including weld cracks, weld breaks, and incomplete welds, etc.) Foil tab welding defect rate Example 1 205 1 0.48% Example 2 201 0 0% Comparative Example 1 202 5 2.47%
[0052] In addition, one normal bare cell from each of Examples 1, 2, and Comparative Example 1 was taken, and the laser-welded area of the outermost cathode foil tab was manually separated to simulate weld cracking. Finished cells were then manufactured using the same process and subjected to charge-discharge tests. The charge-discharge curves are shown below. Figure 4 As shown.
[0053] As shown in Table 1, the use of conductive adhesive coating to assist in connection can significantly reduce the proportion of foil tab welding abnormalities. The conductive adhesive coating can tightly bond the foil tabs and ensure that they are not affected during laser welding. Figure 4The data also shows that even if one layer of the foil tab breaks, the battery cell using this invention can still charge and discharge normally, and its charging and discharging capacity remains unaffected. In contrast, battery cells welded using traditional methods, due to their stacked structure, experience capacity limitations when the foil tab breaks, as the capacity of the broken layer cannot be fully utilized. Therefore, this invention's novel tab connection structure effectively reduces the proportion of abnormal foil tab welding and effectively avoids problems such as increased ohmic impedance, decreased energy density, and short circuits caused by weld breaks or incomplete welds, ensuring the safety and reliability of the secondary battery.
[0054] In the description of this utility model, it should be understood that terms such as "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0055] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.
[0056] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0057] The above embodiments are merely specific examples of this utility model, and their descriptions are quite specific and detailed, but they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of this utility model, and these obvious substitutions all fall within the protection scope of this utility model.
Claims
1. A secondary battery tab connection structure, comprising an electrode plate and a tab plate, wherein the electrode plate is electrically connected to the tab plate via a foil tab, characterized in that: The end of the foil tab is provided with a conductive adhesive coating to form a conductive adhesive connection part that adheres and connects to the electrode plate. The exposed area adjacent to the conductive adhesive coating of the foil tab is formed with a welding connection part that is welded to the electrode plate. The foil tab and the electrode plate are electrically connected through the conductive adhesive connection part and the welding connection part.
2. The secondary battery tab connection structure according to claim 1, characterized in that: The area of the conductive adhesive coating is smaller than the area of the foil tab, and the conductive adhesive coating is located outside the electrode active material layer.
3. The secondary battery tab connection structure according to claim 2, characterized in that: The electrode sheet includes an anode electrode sheet and a cathode electrode sheet, with the anode electrode sheet being formed by stacking or winding the cathode electrode sheets alternately.
4. The secondary battery tab connection structure according to claim 3, characterized in that: The material of the foil tab is the same as the material of the current collector of the electrode plate, which is aluminum foil, copper foil, aluminum mesh, copper mesh or stainless steel foil.
5. The secondary battery tab connection structure according to claim 4, characterized in that: The conductive adhesive coating has a width of 2-8 mm and a thickness of 0.3-10 μm.
6. The secondary battery tab connection structure according to claim 5, characterized in that: The conductive adhesive coating is a gold conductive adhesive coating, a silver conductive adhesive coating, a copper conductive adhesive coating, a carbon conductive adhesive coating, or a carbon nanotube conductive adhesive coating.
7. The secondary battery tab connection structure according to claim 6, characterized in that: The secondary battery is a lithium-ion battery or a sodium-ion battery.
8. The secondary battery tab connection structure according to claim 7, characterized in that: The lithium-ion battery is a ternary material battery, a lithium iron phosphate battery, a lithium manganese oxide battery, or a lithium cobalt oxide battery.
9. The secondary battery tab connection structure according to claim 7, characterized in that: The sodium-ion battery is a polyanion sodium-ion battery, a Prussian blue sodium-ion battery, or a layered oxide sodium-ion battery.
10. The secondary battery tab connection structure according to claim 8 or 9, characterized in that: The conductive adhesive coating is applied to the surface of the foil tab by spraying, rolling, pressing, or scraping.