Sulfur-Rich Molybdenum Sulfide as a Cathode Material for Room Temperature Sodium–Sulfur Batteries

Abstract

The low cost, abundance, and high capacity of sodium and sulfur make them attractive battery materials. However, formation and migration of polysulfides in sulfur batteries causes rapid capacity fade, limiting battery cycle life. Most strategies to mitigate polysulfide shuttling address migration rather than formation and require complicated or expensive synthetic steps. Here, we introduce an amorphous, sulfur-rich molybdenum sulfide as a sulfur equivalent cathode that is simple and easy to make and shows excellent cycling performance with a specific capacity of 537 mAh g–1 at 50 mA g–1, retaining over 200 mAh g–1 at a rate of 1 A g–1.