Drum Gripping Concept for Secured Orientation-Variable Handling in Solid-State Battery Cell Assembly

Abstract As Lithium-ion batteries (LIBs) are forecasted to reach their technological optimization limits in the coming decade, next generation battery technologies, such as solid-state batteries (SSBs), are investigated to enable even higher energy and power densities. However, depending on the utilized solid electrolytes (SEs), the cell components exhibit low mechanical stability or an adhesive behavior with serious implications on handling operations during cell assembly. Additionally, mainly SSB cell components with one-sided coating are currently available, which limit the automated cell assembly to the production of bicells with challenges in securely changing the component’s orientation during stacking with established gripping technologies. In the present research, a drum gripping concept for a secured change of the cell components’ orientation along its pitch axis during handling is introduced. Especially relevant is the avoidance of undesirable folds in the materials which occur in dependence of the adjustable pressure difference and the gripper’s rotation direction. To validate the applicability of the presented concept, an experimental evaluation of the deposition accuracy in relation to the supplied pressure difference with polymer-based SEs and lithium metal anodes is carried out. As key results, adequate deposition accuracies are achieved with deposition with the original orientation and for pressure differences of 0.5 bar. Overall, the proposed gripping concept can be viewed as a valid solution for a flexible automated cell assembly of early-stage test cells which are required for further developments towards the establishment of industry-scale SSB production.