Continuous Roll‐To‐Roll Coating and Drying of Sulfide‐Based Solid Electrolyte Separators for Scalable Manufacturing

Sulfide‐based solid‐state batteries have emerged as a promising successor to conventional lithium‐ion batteries, offering higher energy and power densities while remaining compatible with established battery production processes. Among the key manufacturing steps, continuous coating and drying are critical, directly determining the microstructural uniformity and quality of solid electrolyte separator layers while contributing to energy consumption and manufacturing costs. However, processing parameter effects on the separator during roll‐to‐roll production remain largely unexplored. This study systematically investigates how doctor‐blade coating and convective drying parameters affect the structural and electrochemical properties of sul LPSCl–fide‐based separators in a roll‐to‐roll context, revealing clear correlations through quantitative and qualitative analyses. Observed trends are compared with lab‐scale sulfide‐based components and conventional lithium‐ion electrode manufacturing to identify transferable principles and unique challenges for the sulfide‐based solid electrolyte separator system. Finally, the best‐performing processing parameters are validated by fabricating a highly homogeneous, thin separator via continuous roll‐to‐roll processing. Through the established correlations, critical areas for process and product optimization are identified, advancing the understanding of sulfide‐based separator manufacturing as a viable drop‐in technology for existing battery production lines.