Method and device for laser welding foil and tab

Abstract

The invention discloses a method and device for laser welding a foil and a tab. At least one layer of foil is placed in front of the tab as a laser absorbing surface; then the foil and the tab are adsorbed or pressed together; The focus of the laser is set on the tab, and the foil and the tab are welded. Non-contact laser welding is used to replace the traditional ultrasonic contact welding. The foil and tab are not affected by external forces, and the processing is stable. The efficiency of laser processing is high, and the multi-pulse spot processing of laser can be used.

Description

technical field [0001] The invention relates to the field of lithium battery production, in particular to a method and device for laser welding foil and tabs. Background technique [0002] In the process of welding tabs of lithium-ion battery pole pieces and foils, the traditional welding method is ultrasonic welding, but ultrasonic welding of foils and tabs has several very difficult problems: serious virtual welding (it will also cause detachment after a long time) Welding phenomenon), too large penetration burrs, the tension between the foil and the lug cannot be guaranteed stably and effectively, the discharge current is not enough during the formation discharge process, and the resistance is too large, etc. These unavoidable technical problems will cause trouble to the subsequent process and have a great impact on the production and use of the entire battery. [0003] When the ultrasonic wave acts on the contact surface of the material, it will generate tens of thousan...

AI Technical Summary

Problems solved by technology

[0002] In the process of welding tabs of lithium-ion battery pole pieces and foils, the traditional welding method is ultrasonic welding, but ultrasonic welding of foils and tabs has several very difficult problems: serious virtual welding (it will also cause detachment after a long time) Welding phenomenon), welding penetration burr is too large, the tension between the foil and the tab cannot be guaranteed stably and effectively, the discharge current is not enough during the formation discharge process, the resistance is too large, etc.

Ultrasonic welding is a material contact processing. The contact area between the welding head and the welding seat, the material, the contact time, parallelism, flatness and other parameters will affect the welding process effect, so it is impossible to ensure stable processing between materials. It is very easy to produce solder joints that are too small, virtual soldering, missing soldering, etc.

And because of the contact processing, the service life of the welding head and the welding seat is relatively short, and the continuous consumption cost is high

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