High-throughput battery foil cutting: a comparison of different pulsed laser approaches

E-mobility is currently one of the fastest growing industries. Electric powered vehicles are driving emission free transportation and will consequently replace conventional combustion engine vehicles. The battery industry is a key enabler of the e-mobility sector, laser processing of battery materials has emerged as a promising processing tool for improving manufacturing flexibility and product reliability at a high throughput. The processing of cathode and anode battery foils is an example where laser cutting has reached a high level of maturity and is widely implemented in production lines. The industrial cutting requirements are quite varied based on design and battery chemistry. The challenges are to achieve the highest edge quality at the highest processing speeds. Cutting with cw-lasers often leads to a large heat affected zone, particularly for coated foils, whereas pulsed lasers can typically cut with superior quality. While most foils can be cut with adequate quality with optimized nanosecond lasers, some material combinations benefit from shorter pulses in the ultra-short pulse regime. This contribution gives a general overview about different challenges in battery foil cutting, as well as a comparison between different laser parameters like pulse duration and pulse energy levels. The influence of laser parameters, spot size and working field are discussed as well as the impact of cutting strategy (e.g. single-pass vs. multi-pass).