Improving laser processing of lithium ion battery materials

Abstract

Lasers are increasingly being used in the manufacturing of lithium (Li)-ion batteries. Lasers provide a number of advantages over conventional mechanical processes, including no tool wear, flexible cut pattern, improved edge quality, increased precision, and lower cost of operation. In particular, pulsed infrared (IR) lasers have, in many cases, successfully replaced mechanical punching processes for Li-ion battery foil cutting. While the quality of the cuts achieved using IR lasers is acceptable, it is suspected that slight impurities and defects on cut edges may potentially lead to lower battery performance. One possible way to alleviate such concerns is to improve the processing quality by reducing the wavelength of the processing laser. Another possibility is to use ultrashort-pulse lasers. In this work, we compare foil cutting results using pulsed IR and green lasers. We demonstrate that speeds of greater than 1 m/s can be achieved with a burr height of less than a few microns for cutting both coated and bare anode and cathode foils.