Amorphous CoSnO3@rGO nanocomposite as an efficient cathode catalyst for long-life Li-O2 batteries

ABSTRACT An amorphous CoSnO 3 @rGO nanocomposite fabricated using a surfactant-assisted assembly method combined with thermal treatment served as a catalyst for non-aqueous lithium-oxygen (Li-O 2 ) batteries. In contrast to the specific surface area of the bare CoSnO 3 nanoboxes (104.3 m 2 g –1 ), the specific surface area of the CoSnO 3 @rGO nanocomposite increased to approximately 195.8 m 2 g –1 and the electronic conductivity also improved. The increased specific surface area provided more space for the deposition of Li 2 O 2 , while the improved electronic conductivity accelerated the decomposition of Li 2 O 2 . Compared to bare CoSnO 3 , the overpotential reduced by approximately 20 and 60 mV at current densities of 100 and 500 mA g −1 when CoSnO 3 @rGO was used as the catalyst. A Li-O 2 battery using a CoSnO 3 @rGO nanocomposite as the cathode catalyst cycled indicated a superior cyclic stability of approximately 130 cycles at a current density of 200 mA g –1 with a limited capacity of 1000 mAh g –1 , which is 25 cycles more than that of the bare amorphous CoSnO 3 nanoboxes.