Herein,a three-dimensional hollow reduced graphene oxide(HrGO)with a hierarchically porous structure was successfully synthesized to load sulfur,where the sulfur loading could reach as high as 91.4 wt%.This stable str...Herein,a three-dimensional hollow reduced graphene oxide(HrGO)with a hierarchically porous structure was successfully synthesized to load sulfur,where the sulfur loading could reach as high as 91.4 wt%.This stable structure was obtained by the chemical-assisted reduction of oxygen-containing groups and polyvinyl pyrrolidone,removal of silica templates,and freeze drying.Owing to the hierarchical pores and doped nitrogen in HrGO,the HrGO-supported sulfur(HrGO/S)cathode exhibited superior electrochemical performance with high rate capacity and long cycling life.HrGO/S with the sulfur content of 84.43 wt% delivered the high specific capacity of 863 mA h g^(−1) at the high current rate of 2C with coulombic efficiency greater than 99.5%and maintained the reversible capacity of 463 mA h g^(−1) after 600 cycles,corresponding to the capacity decay of 0.077% per cycle.Even when the sulfur content was as high as 91.4 wt%,HrGO/S still exhibited the specific capacity of 810 mA h g^(−1) at 2C.The hierarchically porous structure and doped nitrogen synergistically rendered HrGO a promising host material for lithium–sulfur batteries.展开更多
基金supported by the National Natural Science Foundation of China(No.51772225).
文摘Herein,a three-dimensional hollow reduced graphene oxide(HrGO)with a hierarchically porous structure was successfully synthesized to load sulfur,where the sulfur loading could reach as high as 91.4 wt%.This stable structure was obtained by the chemical-assisted reduction of oxygen-containing groups and polyvinyl pyrrolidone,removal of silica templates,and freeze drying.Owing to the hierarchical pores and doped nitrogen in HrGO,the HrGO-supported sulfur(HrGO/S)cathode exhibited superior electrochemical performance with high rate capacity and long cycling life.HrGO/S with the sulfur content of 84.43 wt% delivered the high specific capacity of 863 mA h g^(−1) at the high current rate of 2C with coulombic efficiency greater than 99.5%and maintained the reversible capacity of 463 mA h g^(−1) after 600 cycles,corresponding to the capacity decay of 0.077% per cycle.Even when the sulfur content was as high as 91.4 wt%,HrGO/S still exhibited the specific capacity of 810 mA h g^(−1) at 2C.The hierarchically porous structure and doped nitrogen synergistically rendered HrGO a promising host material for lithium–sulfur batteries.
