Lithium-ion battery laser welding sealing technology

Abstract

The invention relates to a laser beam welding and sealing technology for Li-ion battery, which realizes consecutive sealing weld to the battery shell and the battery cover of a Li-ion battery using a laser welder with 600 Hz to 20 KHz of output frequency. The laser beam welding and sealing technology for Li-ion battery of the invention carries out a consecutive sealing weld on the Li-ion battery by means of continuous output of laser energy or high frequency of the laser welder. The welding way can maintain the melting state of a welding seem all the time and push forward. The welding has the advantages of good welding effect as well as smooth and beautiful appearance; furthermore, the nugget zone in the welding centre is completely melted during welding; therefore, after cooling, the residual inter-stress of the welding joint is weak and bad phenomena such as cracking is avoided.

Description

【Technical field】

[0001] The invention relates to a lithium ion battery sealing process, in particular to a lithium ion battery continuous laser welding sealing process. 【Background technique】

[0002] The traditional lithium-ion battery laser welding seal adopts the solid pulse laser welding method. The solid pulse laser welding method is essentially spot welding, and each welding spot has 60% to 90% overlap. In this way, the multi-point overlapping method finally realizes line welding. . In traditional welding equipment, the highest pulse frequency is generally 50 Hz, and the welding speed is 6-8 mm / s. The shape of the molten pool formed by the spot welding is a parabolic shape with a large top and a small bottom. In the case of multiple spot welding overlapping, the penetration depth of the weld seam will be uneven.

[0003] Moreover, pulse welding belongs to heat conduction welding. The laser is irradiated on the aluminum shell of the battery shell to heat up the surfa...

Images