Toward Calenderability of High‐Energy Cathode based on NMC622 during the Roll‐to‐Roll Process

Abstract

For the economical production of high‐quality lithium‐ion batteries, a comprehensive understanding of all processing steps under real production conditions, especially in the electrode‐manufacturing step, is mandatory. It has been shown that calendering of the cathode has a significant impact on the electrode quality and hence affects their subsequent processability in the battery production. Undesirable electrode deformation induced by the calendering process may lead to unnecessary wastage during the roll‐to‐roll process. To increase the yield rate of high‐energy electrode production under industrial‐oriented conditions, an extensive recipe evaluation by applying mixture design methods has been carried out on the lab scale. It has been shown that the inactive carbon black/PVDF phase as well as the amount of SFG6L in the electrode formulation plays an important role in the calendering processability of the high‐energy NMC622 cathode. From the statistical data analysis, an optimized recipe has been proposed and afterward validated at the research production line under industry‐relevant conditions. A significant reduction of the scrap rate caused by the calendering process is observed after optimizing the recipe due to its better calenderability.