High-capacity Li2S–graphene oxide composite cathodes with stable cycling performance

Abstract

With its high theoretical capacity of 1166 mA h g⁻¹, Li₂S is a promising prelithiated cathode material for applications such as vehicle electrification and grid energy storage. Herein, we demonstrate facile synthesis of Li₂S–graphene oxide composites for use as high-capacity and stable-cycling Li₂S cathodes. The wrapping of graphene oxide onto the surface of Li₂S through favorable lithium–oxygen interactions helps to minimize the dissolution of intermediate polysulfides into the electrolyte during cycling, which is a major reason for rapid capacity decay. Using the Li₂S–graphene oxide composites as a cathode material, we demonstrate a high discharge capacity of 782 mA h g⁻¹ of Li₂S (∼1122 mA h g⁻¹ of S) with stable cycling performance over 150 charge–discharge cycles.