Three-dimensional MoSx (1 < x < 2) nanosheets decorated graphene aerogel for lithium-oxygen batteries

The electrochemical performance of lithium-oxygen (Li-O-2) batteries depends largely on the architecture and catalytic effectiveness of the oxygen cathode. Herein, in this study, a graphene aerogel decorated with MoSx nanosheets (MoSx/HRG) with a three-dimensional porous framework synthesized using a one-step hydrothermal reaction followed by freeze-drying is reported. The MoSx/HRG aerogel possesses hierarchical mesopores and micropores, which could facilitate electrolyte impregnation and oxygen diffusion, and provide much more accommodation space for the reaction products. The lithium-oxygen batteries based on this MoSx/HRG aerogel cathode show improved electrochemical performance, with a high initial discharge capacity up to 6678.4 mA h g (1) at a current density of 0.05 mA cm (2) and better cycling capability with a cut-off capacity of 500 mA h g(-1) at a current density of 0.1 mA cm(-2), compared with the lithium-oxygen batteries based on an HRG aerogel cathode. The enhanced performance is ascribed to the excellent catalytic activity of the MoSx nanosheets and the unique three-dimensional porous architecture.