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

Abstract

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.

Keywords:

• All-solid-state batteries
• sulfide-based solid electrolytes
• battery production
• drying process
• drying rates

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Additional information

Funding

This work was supported by the BMW Group. The authors wish to thank the Bavarian Ministry of Economic Affairs, Regional Development and Energy for funding the research project “Industrialisierbarkeit von Festkörperelektrolytzellen.” We also wish to thank the German Federal Ministry for Economic Affairs and Energy and the Bavarian Ministry of Economic Affairs, Regional Development and Energy for funding the work in the BMW project “IPCEI EuBatIn” (16BZF205).