The effect of process parameters on the high-speed cut quality of Li-ion electrodes using a single mode continuous fiber laser

Coated Al and Cu current collectors are employed in the production of Li-ion batteries (LIBs) serving as cathodes and anodes, respectively. The increasing demand and the need for net zero-defect cutting quality are driving industrial production towards fast and reliable technologies. Laser cutting of LIB electrodes is an efficient and cost-effective alternative to conventional mechanical methods, enabling high accuracy and less damaged active material while maintaining high processing speeds. Thanks to remote laser technology flexibility, several combinations of process parameters, electrode material, and thicknesses of the electrode sandwich have been studied. This material variety discussed in the literature reflects the need of the industry to exploit different solutions. Currently, electrode cutting mainly involves the application of short pulse nanosecond (ns) fiber laser. However, the fast-advancing technology of laser manufacturing (including laser sources, optics and scanning heads) allows for new opportunities to improve process productivity and quality. This study evaluates the interaction between a single mode (SM) continuous wave (CW) source and LIB electrodes, exploring the effects of laser power and scanning speed (up to 11 m/s) on thermal defects. These include clearance width and heat affected zone (HAZ) for the anode, as well as HAZ width and the quantity of spherical defects detached from the aluminum foil for the cathode. This investigation identified a significant reduction of defects for both materials when higher speeds are set. Specifically, high-quality cuts were achieved at 5.5 m/s for the anode and 4.4 m/s for the cathode, with a clearance width kept below 20 μm and HAZ under 30 μm.