Laser welding is an important process in battery manufacturing

Laser welding is the only non-contact, high-precision and efficient welding method; it can weld and seal battery structural parts economically and quickly. Laser processing usually includes laser cutting, laser welding, and laser surface treatment. In the entire power battery manufacturing, including cells, modules and packs, there are about 19 main components that need to be welded, of which: 11 welding must currently be laser welded; 5 welding may use laser welding; 3 welding will not Use laser welding. In square shell batteries, laser welding is required for sealing nails, cover plate components and seals; in cylindrical batteries and modules, the parts that require laser welding include tabs, caps, bus bars, etc.

Laser welding quality improvement and inspection

In terms of module side plate welding, power battery modules often use aluminum alloy profiles and plates as the structural components of the outer frame of the module. The quality of the welding determines the rigidity of the overall structure of the module. Different welding heads and processes can be used to obtain different welding effects, and a variety of process methods have also been developed for side plate laser welding. The porosity of the ordinary welding head is 10%, the porosity of the double beam welding head is 3%, and the porosity of the swing spot welding head is only 1%. More and more advanced laser welding equipment and processes continue to improve welding quality and reduce porosity.

In addition, laser welding of cell sealing is an important process in battery manufacturing, which greatly affects the yield of batteries. While the welding speed of cells is getting faster and faster, it is also necessary to ensure the weld performance such as weld consistency. A variety of laser welding sealing processes are derived from this. Among them, the high-speed swing welding of fiber laser, the welding seam is smooth and smooth, and the consistency is good. The swing head has a repairing effect on the explosion point with the increase of the welding frequency.