Hierarchical Architecture of Mesoporous Carbon Wrapped Graphene as Matrix Material of Sulfur for Cathode Material of Lithium-Sulfur Batteries
摘要
Hierarchical architecture materials of mesoporous carbon wrapped graphene (MC@G) composite are prepared by a sol-gel coating method, MC@G composites are infiltrated with sulfur to prepare cathode material of lithium-sulfur batteries (Li-S) with high discharge capacity at low current. The MC@G was synthesized using graphene as conductive base material and mesoporous carbon shell wrapped on the surface of graphene as a matrix for loading sulfur, which results in high utilization of active material at low current. The hierarchical architecture of MC@G carbon/carbon nanocomposites forms an effective conducting base material for electron transport in electrode material, which significantly improves the electronic conductivity of cathode material and utilization of active material. Taking advantage of the structure, the S/MC@G cathode material exhibits an initial specific discharge capacity of 1158 mA h g−1 and 1131 mA h g−1 at current of 0.1 C and 0.5 C, the S/MC@G cathode material exhibits higher capacity retention and rate performance than S/rGO cathode material. We believe that the hierarchical mesoporous architecture of MC@G can also be applicable for designing some other electrode materials for energy storage.