Although lithium-sulfur batteries are one of promising rechargeable energy storage devices,their wide applications are impeded by the lithium polysulfides shutle effect,low electronic conductivity of the cathode,and s...Although lithium-sulfur batteries are one of promising rechargeable energy storage devices,their wide applications are impeded by the lithium polysulfides shutle effect,low electronic conductivity of the cathode,and sluggish redox reaction kinetics of lithium polysulfides.In this work,reduced graphene oxide was decorated with CoSe2 hollow nanospheres to form an RGO-CoSe2 composite that was used as a host material to support S in the cathode.The RGO-CoSe2 composite has the following superiorities:(1)enhanced electronic conductity,(2)accommodation of the volumetric change of cathode materials,(3)effective confinement of numerous lithium polysulfides species due to chemisorption,(4)expedition of the redox kinetics of lithium polysulfides.As expected,the RGO-CoSez-based cathode exhibited the reversible specific capacity of 1,044.7 mAh/g at 0.2C and 695.7 mAh/g at 2C,together with ecellent cycling stability of 0.071% average capacity decay per cycle over 400 cycles at 1C.展开更多
基金supported by the National Natural Science Foundation of China (51802029)the Scientific Research for the Introduction of Talents of Changsha University (SF1606)。
基金the National Natural Science Foundation of China(No.51802029)Natural Science Foundation of Hunan Province,China(No.2017JJ3343)+2 种基金Scientific Research Fund of Hunan Provincial Education Department(No.17B028)Project of Changsha bureau of science and technology(No.k1705062)Scientific Research for The Introduction of Talents of Changsha University(No.SF1606).
文摘Although lithium-sulfur batteries are one of promising rechargeable energy storage devices,their wide applications are impeded by the lithium polysulfides shutle effect,low electronic conductivity of the cathode,and sluggish redox reaction kinetics of lithium polysulfides.In this work,reduced graphene oxide was decorated with CoSe2 hollow nanospheres to form an RGO-CoSe2 composite that was used as a host material to support S in the cathode.The RGO-CoSe2 composite has the following superiorities:(1)enhanced electronic conductity,(2)accommodation of the volumetric change of cathode materials,(3)effective confinement of numerous lithium polysulfides species due to chemisorption,(4)expedition of the redox kinetics of lithium polysulfides.As expected,the RGO-CoSez-based cathode exhibited the reversible specific capacity of 1,044.7 mAh/g at 0.2C and 695.7 mAh/g at 2C,together with ecellent cycling stability of 0.071% average capacity decay per cycle over 400 cycles at 1C.
