All-solid-state batteries are probably the next generation of lithium-ion batteries. The replacement of the liquid electrolyte with a solid material can enhance the energy and power density as well as the battery safety. One possible type of electrolyte are sulfides with high ionic conductivity.[1] First promising results are obtained at lab-scale production. As a next step, the establishment of continuous processing to realize a production at industrial-scale is inevitable.[2] One important process step here is the densification of sulfide-based cathodes and separators which can be realized by calendering. A compression can give rise to a higher energy density, electrical as well as ionic conductivity. Moreover, mechanical properties like adhesion strength can be increased. The solid electrolyte cannot flow or infiltrate the pores of the active material like the liquid material.[3] Therefore, the electrode/electrolyte contact area is even more important and significantly affected by the densification. In literature, a compression is usually realized at lab-scale with a lab-press. One study also reports a compression of full pouch cells by a warm isostatic press.[4] To our knowledge, specific and detailed studies regarding a densification of slurry-based cathodes and separators with sulfidic electrolyte by calendering has not been performed yet. However, it is of high importance to drive forward the progress of sulfide-based solid-state batteries. On this poster, first results and concepts with respect to calendering are presented taking important process parameters like roll temperature and line load into account.

References
[1] J. Janek and W. Zeier, Nature Energy 1, 16141 (2016)
[2] J. Schnell et al., Journal of Power Sources 382, 160-175 (2018)
[3] R. Koerver et al., Chemistry of Materials 29, 5574-5582 (2017)
[4] Y.-G. Lee et al., Nature Energy 5, 299-308 (2020)