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 (similar to 1122 mA h g(-1) of S) with stable cycling performance over 150 charge-discharge cycles.