CoS2 nanoparticles–graphene hybrid as a cathode catalyst for aprotic Li–O2 batteries

Cobalt sulfides have been demonstrated to possess high oxygen reduction activity in fuel cells with aqueous solutions. Herein, we report the use of a CoS2 nanoparticles–graphene (CoS2/RGO) hybrid as a cathode catalyst for aprotic lithium–oxygen (Li–O2) batteries, where the CoS2/RGO was prepared by a facile hydrothermal method. The resulting cells exhibited low discharge/charge overpotentials and a high rate capability, which make the metal sulfide catalysts promising cathode materials for Li–O2 batteries.