Sustainable protein‐based binder for Lithium‐Sulfur cathodes processed by a solvent‐free dry‐coating method

In the market for next-generation energy storage, lithium-sulfur (Li-S) technology is one of the most promising candidates due to its high theoretical specific energy and cost-efficient ubiquitous active materials. In this study, this cell system is combined with a cost-efficient sustainable solvent-free electrode dry-coating process (DRYtraec): So far, this process has been only feasible with PTFE-based binders. To increase the sustainability of electrode processing and to decrease the undesired fluorine content of Li-S batteries, a renewable, biodegradable, and fluorine-free polypeptide is employed as a binder for solvent-free electrode manufacturing. The yielded Sulfur/Carbon dry-film cathodes were electrochemical evaluated under lean electrolyte conditions at coin and pouch cell level, using the state-of-the-art DME/DOL electrolyte as well as the sparingly polysulfide solvating electrolytes HME/DOL and TMS/TTE. These results demonstrate that the PTFE binder can be replaced by the biodegradable sericin as the cycle stability and performance of the cathodes was retained.