Electric vehicles allow emission-free transportation but offer only limited driving range. A technological jump to all-solid-state batteries (ASSBs) that safely implement a lithium metal anode, enabling high energy densities, would dramatically boost the battery performance.

Recent research efforts have yield to a variety of inorganic solid electrolytes with extremely high ionic conductivity at room temperature. In particular, low density sulfidic electrolytes are attractive candidates for high-energy ASSBs. However, many issues still need to be addressed^[1]. Herein, we focus on the limited electrochemical stability of sulfidic electrolytes that results in decomposition reactions accompanied by increasing resistances at the electrode/electrolyte-interface.

In academic research, mostly pellet-type cells are used to investigate the electrochemical performance. However, this type of cell set-up is far from being practical for large scale battery production and application. A key advantage of sulfidic electrolytes is their ductility permitting this class of materials to be simply cold pressed. Thus, herein, slurry-based procedure is presented that easily allows to process a composite cathode. The cells demonstrate good electrochemical performance, although the type and amount of conductive carbon as well as the active material particles size, are crucial parameters.

Reference

[1] J. Janek, W. G. Zeier, Nat. Energy 2016, 1, 16141.

Acknowledgment

The research leading to these results has received funding from the German Federal Ministry of Education and Research under grant agreement no. 03XP0026F.