Ultra-thin electrode tab welding method

Abstract

The invention provides an ultra-thin electrode tab welding method. An MOPA laser with a preset set of parameter values is adopted to weld ultra-thin electrode tabs which are led out from multiple layers of battery cells and have the thickness of being smaller than 0.2mm, so that the multiple layers of ultra-thin electrode tabs are connected. Due to the fact that the single-point power of the MOPA laser is high, the welding speed can be increased; and due to the fact that the Q pulse width of the MOPA laser is in a nanometer level, the time of a laser point for staying in a welding area can be shorter, then the temperature of the welding area in the welding process can be reduced, the temperature requirement can be met, the situation that the phenomenon of welding point failure and the phenomenon of insufficient welding cannot appear when the multiple layers of ultra-thin electrode tabs are subjected to penetration welding can be guaranteed, the smoothness of a welding line is ensured, the risk of generating potential safety hazards is reduced, and the battery safety is improved. In addition, due to the selection of the preset set of parameter values, the welding result can meet the tension requirement.

Description

technical field [0001] The invention relates to the technical field of laser welding, in particular to an ultra-thin tab welding method. Background technique [0002] In the prior art, there are multiple layers of battery cells in some batteries, and each layer of battery cells leads to ultra-thin tabs, the thickness of which is usually less than 0.2 mm. In order to make the multi-layer battery cells work together, it is necessary to weld the ultra-thin tabs of the multi-layer battery cells to ensure that the multi-layer ultra-thin tabs are connected to each other. [0003] However, for welding between multi-layer ultra-thin tabs, a continuous laser is usually used, which will lead to solder joint failure when the welded multi-layer ultra-thin tabs penetrate through welding, and there will be false welding In some cases, the welding line will be poorly connected, causing the internal resistance of the battery to be too large, the battery cannot be discharged smoothly or the...

AI Technical Summary

Problems solved by technology

[0003] However, for welding between multi-layer ultra-thin tabs, a continuous laser is usually used, which will lead to solder joint failure when the welded multi-layer ultra-thin tabs penetrate through welding, and there will be false welding If the welding line is not in good contact, the internal resistance of the battery is too large, the battery cannot be discharged smoothly or the battery is undervoltage, which brings safety hazards to the battery.

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