Influence of Geometrical Battery Electrode Defects on the Format-Flexible Laser Singulation Process

The electrification of powertrains is essential for transforming the transport sector in a resource-efficient and environmentally sustainable manner, with batteries playing a central role. However, the high costs associated with battery production and raw materials highlight the need for waste minimisation. A critical step in manufacturing is the singulation of electrodes into single sheets. While laser singulation offers wear-free and format-flexible cutting compared to mechanical punching, current handling units impose limitations on format flexibility. Additionally, geometrical defects such as wrinkles and corrugations lead to unstable cutting processes due to the small focal length of laser beams. Furthermore, geometrical defects and the process parameters during singulation highly affect the dimensional accuracy of the single sheets in width and length. This study introduces an innovative machine concept for format-flexible laser singulation of electrode sheets. The system integrates vacuum point grippers for electrode fixation and mechanical jaw grippers to control web tension. The configuration of point grippers on a magnetic base can be rapidly adapted to modify the electrode formats. ... mehrBased on that, the experimental investigations assess the correlation of calendering parameters of an NMC622 cathode on the cutting quality and the dimensional sheet accuracy. The findings demonstrate that the deviation in sheet width, oriented toward the electrode web's running, exhibits a significantly stronger correlation with the investigated calendering parameter levels than the deviation in sheet length. The roller temperatures have been shown to have the most significant impact on the sheet width.