2, Center for Energy and Environmental Chemistry (CEEC Jena), Jena University, Jena, , Germany
Sulfur and chalcogenides are attractive materials for rechargeable batteries thanks to their generally high specific capacity. Other relevant properties such as conductivity, plasticity or volume expansion during lithiation/sodiation largely vary and depend on the specific compound of interest. Sulfur and the ideal discharge product Li2S or Na2S are insulating which requires a sophisticated electrode design with a porous carbon matrix. CuS, on the other hand, is both electronically and ionically conductive which generally benefits the reversibility of the cell reaction. Finally, MoS2, is very soft which may be of advantage considering the large volume expansion during lithiation/sodiation. In this presentation, we will discuss specific properties of sulfur in contact with a porous carbon matrix combined with results on room-temperature sodium-sulfur cells. We also address the use of copper sulfide and molybdenum sulfide as electrode material for lithium/sodium solid state batteries which can show high capacity despite their large volume expansion during cell cycling.