Laser Application Technology of Lithium-ion Battery for EV 2011-28-0074

The cutting and welding of lithium-ion battery for EV using the fiber laser will become an applied technology that steals the limelight, and it can provide both flexibility and quality of the battery manufacturing process suddenly all over the world. We report the newest technology for the processing property and some advantage with newly developed 3 kW fiber laser. In the welding experiment, the aluminum lid of t1.5 mm was evaluated in the case of A1050 and t0.5 mm by using the fiber laser of 1 kW and the quality in the surface and the cross section when the fillet was welded was evaluated. The welded condition was CW (Continuous Wave), 800W and 60 mm/s, was able to even up half the welding depth of about 0.7 mm of the lid side as long as the section photograph was observed, and was able to judge a chemical liquid to be good quality as a seam welding. As the seal case welding condition, beautifully melting is necessary as the condition, that is non-keyhole welding and not penetrate on the reverse, at the same time the laser light should not be irradiated the spatter inside the case. In the cutting experiment, the speed that was able to be cut while maintaining the quality that became less than height 5 μm of role up with aluminum and copper foils from t0.01 mm to t0.22 mm were cut by 150W to 300W at the range of 400 mm/s to 800 mm/s. It has been understood that there is a suitable combination between the thickness of the foil and the laser output. Also some special mentioned result like laser characteristic like beam mode, output power and stability are described respectively in more detail. This laser was the first Japanese multi-kW fiber laser developed by Miyachi Corporation recently. The beam isolator works well avoiding damage from back reflection.