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