Fundamental investigation on drying rates of cathodes and separators for sulfide-based all-solid-state batteries

Energy storage systems play an important role in future applications for storing renewable electric energy with respect to slowing down climate change. In this context, the sulfide-based all-solid-state battery (ASSB) addresses the need for next-generation battery storage aiming at higher energy densities and increased safety. As known from current research, sulfide-based solid electrolytes show multiple electrochemical advantages, but the upscaling of suitable process technologies to fabricate large-scale components is still omitted. Adapting already known machinery from conventional lithium-ion battery (LIB) cell production might be possible, but most of the process and material parameters during manufacturing are unknown. However, a wet coating procedure might be applicable, but evokes the application of a downstream drying step. The drying process is the most energy- and cost-intensive step, where currently either water or N-methyl-2-pyrrolidone is evaporated from the LIB electrode slurry resulting in a dried thin-film sheet. For ASSBs, no analysis regarding drying rates, an important parameter in this process, is published so far. This study gives an overview of theoretical and experimental investigations on the drying behavior of composite cathodes and solid separators with sulfide-based electrolytes. These results enable the derivation of implications for the industrial drying process for all-solid-state battery components.