Invisible aluminum-to-nickel tab structure
By introducing embossed interlocking and anti-fracture adhesive in the aluminum-to-nickel tab structure, combined with laser welding, the problem of insufficient strength at the welding interface of the aluminum-to-nickel tab was solved, achieving improved mechanical strength and impact resistance while maintaining battery conductivity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- TIANJIN JUYUAN NEW ENERGY TECH CO LTD
- Filing Date
- 2025-06-05
- Publication Date
- 2026-05-12
AI Technical Summary
The welding interface of aluminum-to-nickel tabs in existing lithium-ion batteries is not strong enough and is prone to breakage due to mechanical impact. Furthermore, traditional welding methods affect battery performance.
The structure combines an embossed interlocking structure with anti-fracture adhesive for the tabs, and is reinforced by laser or ultrasonic welding to form a composite structure of aluminum tabs and nickel connecting pieces, which increases mechanical strength and impact resistance.
It significantly improves the mechanical strength and impact resistance of the aluminum-nickel interface, more than doubles the number of bending cycles of the tab, increases the drop test pass rate from 60% to 100%, and shows no significant decrease in electrical conductivity.
Smart Images
Figure CN224232887U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of lithium-ion battery technology, specifically relating to a stealthy aluminum-to-nickel tab structure. Background Technology
[0002] In the manufacturing process of lithium-ion batteries, aluminum tabs (positive electrodes) are typically welded to nickel connecting tabs (external conductive connecting tabs). However, aluminum and nickel have significant differences in physical properties (such as coefficient of thermal expansion, hardness, and ductility), making them prone to breakage and failure after welding due to mechanical impact (such as battery drops).
[0003] In existing technologies, the main connection methods for aluminum-to-nickel tabs include direct laser welding, ultrasonic welding, riveting, or mechanical pressing. Direct laser welding easily forms brittle intermetallic compounds at the interface, making it prone to breakage upon drop; ultrasonic welding has limited strength and may crack under long-term vibration or impact; riveting or mechanical pressing may introduce additional resistance, affecting battery performance. The main problems with existing technologies are insufficient strength of the aluminum-nickel weld interface, stress concentration in the weld area, and a lack of buffering mechanisms, making them unable to effectively address tab breakage caused by drop impacts. Utility Model Content
[0004] The purpose of this invention is to provide an invisible aluminum-to-nickel tab structure to solve the problems existing in the prior art.
[0005] To achieve the above objectives, this utility model provides the following technical solution: an invisible aluminum-to-nickel tab structure, comprising an aluminum tab and a nickel connecting piece, wherein the connection area between the aluminum tab and the nickel connecting piece is provided with a matching embossed structure, the embossed structure enables the aluminum tab and the nickel connecting piece to form a mechanical interlock, and a tab adhesive is provided at the interface of the connection area to prevent breakage.
[0006] Preferably, the embossed structure is wavy, serrated, or grid-shaped.
[0007] Preferably, the connection area between the aluminum tab and the nickel connecting piece is welded to form a solder joint, and the solder joint is located within the buffer zone connecting the tab adhesive and the metal strip.
[0008] Preferably, the thickness of the anti-fracture layer of the tab adhesive is 10-50 μm, the adhesive width is consistent with the width of the aluminum tab, and the adhesive length L≥0.1 mm.
[0009] Preferably, the aluminum tab and the nickel connecting piece are fixed by laser welding or ultrasonic welding, and the welding area is located within the overlapping range of the embossed structure.
[0010] Preferably, the overlap width between the aluminum tab and the nickel connecting piece is ≥3mm.
[0011] Preferably, the height H of the embossed structure is 0.1-2 times the thickness of the tab.
[0012] Preferably, the anti-breakage coating is applied between the breakage point of the nickel connector and the contact surface of the aluminum electrode.
[0013] Preferably, the aluminum tab has a thickness of 0.08-0.5 mm, and the nickel connecting piece has a thickness of 0.08-0.5 mm.
[0014] Preferably, the outer side of the welding area is provided with an anti-oxidation layer or an insulating wrapping layer.
[0015] The beneficial effects of this utility model are as follows: This utility model, through a composite structural design of "embossed interlocking + tab adhesive anti-breakage + welding reinforcement," significantly improves the mechanical strength and impact resistance of the aluminum-nickel interface. Specifically, the embossed structure increases the contact area through mechanical interlocking, and combined with laser or ultrasonic welding, it can greatly enhance tensile strength and shear resistance, avoiding the fracture problems caused by brittle intermetallic compounds in traditional welding. The tab adhesive anti-breakage layer uses flexible materials (such as silicone or polyimide adhesive) to fill the gap between the nickel connector and the aluminum tab, effectively absorbing drop impact energy and preventing crack propagation caused by rigid impact. This increases the tab's bending resistance by more than double, and the pass rate in the 1.8m drop test increases from 60% for traditional structures to 100%.
[0016] This structure offers both process compatibility and cost advantages. The embossing and stamping process is mature, and the adhesive used for the tabs is minimal and applied internally, without affecting the battery assembly process or requiring significant adjustments to existing production lines. The concealed design, achieved by wrapping the welding area with insulating material, maintains a clean appearance while achieving electrical insulation, with only a limited increase in overall cost. Testing showed that the tabs in this embodiment exhibited a voltage drop of only 0.003-0.009V after 72 1.8m drop tests, significantly lower than the 0.089V of traditional tabs, validating its advantage of significantly improving reliability while maintaining conductivity. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention after welding;
[0018] Figure 2 for Figure 1 Enlarged view of point A in the middle;
[0019] Figure 3 This is a schematic diagram of the embossed interlocking structure in this utility model;
[0020] Figure 4 This is a schematic diagram showing the coating position of the electrode tab in this utility model. Detailed Implementation
[0021] It should be noted that, without conflict, the embodiments and features in the embodiments of this utility model can be combined with each other.
[0022] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, 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, and therefore should not be construed as a limitation on this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.
[0023] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixed connection," and "fixed connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0024] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings and preferred embodiments.
[0025] like Figure 1-4As shown, a stealthy aluminum-to-nickel tab structure includes an aluminum tab 001 and a nickel connecting piece 002. The connection area between the aluminum tab and the nickel connecting piece is provided with a matching embossed structure 005 (such as wavy, sawtooth, or grid-like), with an embossing height H of 0.1 to 2 times the tab thickness. The embossed structure mechanically interlocks the aluminum tab and the nickel connecting piece, increasing the contact area and tensile strength. A tab adhesive anti-fracture layer 006 is provided at the interface of the connection area. The tab adhesive anti-fracture layer is located in the overlapping area of the middle connecting line of the aluminum-nickel connection area (at the breakage point of the nickel connecting piece). The tab adhesive anti-fracture layer is a small amount of flexible tab adhesive (such as polyimide adhesive, silicone, or modified epoxy resin), with a thickness T = 10-50 μm, a dispensing width consistent with the width of the aluminum tab, and a dispensing length L ≥ 0.1 mm. The tab adhesive anti-fracture layer is used to absorb the impact energy of the nickel connecting piece's cut against the aluminum tab substrate during a collision, preventing impact fracture. Based on the embossed interlocking structure, laser welding or ultrasonic welding is used for reinforcement to ensure electrical conductivity and mechanical strength. The connection area between the aluminum tab and the nickel connecting piece is welded to form a solder joint, located within the buffer zone connecting the tab adhesive and the metal strip. The solder joint's location within the tab adhesive facilitates sealing and completes shell corrosion.
[0026] The following is an example:
[0027] Prepare the required substrates: aluminum tab 001 (thickness is usually 0.08~0.5mm), select 0.1mm thickness; nickel connecting piece 002 (thickness is 0.08~0.5mm), select the same thickness of 0.1mm;
[0028] The aluminum tabs and nickel connecting pieces undergo surface pretreatment. The aluminum tabs are cleaned with alcohol or plasma to remove the oxide layer and oil, while the nickel surface is lightly polished to improve subsequent weldability. The pretreated aluminum tabs and nickel connecting pieces are then leveled and overlapped, with an overlap width of ≥3mm. A wavy embossing pattern (wavelength 0.5mm, wave height 0.1mm) is stamped into the overlapping area using embossing equipment. This forms an interlocking embossed structure. A high-frequency ultrasonic metal welding machine (frequency 20~40kHz, power 2000~4000W) is used to weld the overlapping area, resulting in weld point 004, further strengthening the bond between the two metals. A silicone adhesive layer with a length of 0.5mm and a thickness of 20μm is applied to the broken edge of the nickel strip. Finally, a concealment treatment is performed, wrapping the welding area and aluminum tabs with silicone, ensuring the tab adhesive 003 reaches the specified dimensions of 11mm width and 5mm height, achieving insulation and concealment.
[0029] The prepared tabs were subjected to tensile strength tests. After using the tabs of this invention to prepare soft-pack batteries, drop tests were conducted to compare their drop performance with that of traditional tabs.
[0030] The nickel strip fracture was repeatedly bent. In the traditional electrode tab, the aluminum foil cracked after 42 bends, while the electrode tab of the embodiment remained intact after ≥100 bends, improving the bending resistance by more than 1 times. The pass rate of the 1.8m drop test increased from 60% to 100%.
[0031]
[0032] For those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model.
Claims
1. A stealthy aluminum-to-nickel tab structure, characterized in that, It includes an aluminum electrode tab and a nickel connecting piece. The connection area between the aluminum electrode tab and the nickel connecting piece is provided with a matching embossed structure. The embossed structure makes the aluminum electrode tab and the nickel connecting piece mechanically interlocked, and an electrode tab adhesive is provided at the interface of the connection area to prevent breakage.
2. The stealth aluminum-to-nickel tab structure according to claim 1, characterized in that, The embossed structure is wavy, sawtooth, or grid-like.
3. The stealth aluminum-to-nickel tab structure according to claim 1, characterized in that, The aluminum tab and the nickel connecting piece are welded together to form a solder joint, and the solder joint is located within the buffer zone connecting the tab adhesive and the metal strip.
4. The stealth aluminum-to-nickel tab structure according to claim 1, characterized in that, The thickness of the anti-fracture layer of the tab adhesive is 10-50μm, the adhesive width is consistent with the width of the aluminum tab, and the adhesive length L≥0.1mm.
5. The stealth aluminum-to-nickel tab structure according to claim 1, characterized in that, The aluminum tab and the nickel connecting piece are fixed by laser welding or ultrasonic welding, and the welding area is located within the overlapping area of the embossed structure.
6. The stealth aluminum-to-nickel tab structure according to claim 1, characterized in that, The overlap width between the aluminum tab and the nickel connecting piece is ≥3mm.
7. The stealth aluminum-to-nickel tab structure according to claim 1, characterized in that, The height H of the embossed structure is 0.1-2 times the thickness of the tab.
8. The stealth aluminum-to-nickel tab structure according to claim 1, characterized in that, The anti-breakage coating is applied between the broken edge of the nickel connector and the contact surface of the aluminum electrode.
9. The stealth aluminum-to-nickel tab structure according to any one of claims 1-8, characterized in that, The aluminum tab has a thickness of 0.08-0.5 mm, and the nickel connecting piece has a thickness of 0.08-0.5 mm.
10. The stealth aluminum-to-nickel tab structure according to claim 5, characterized in that, The welding area is provided with an anti-oxidation layer or an insulating wrapping layer on the outside.