Graphene-coated mesoporous carbon/sulfur cathode with enhanced cycling stability

A self-assembly approach is used to fabricate a graphene-coated mesoporous carbon/sulfur composite. The graphene coating on the surface of the composite is 15-20 nm in thickness, and sulfur is well dispersed in the pores of mesoporous carbon and the interfaces between the mesoporous carbon and graphene sheets after a heat treatment at 300 degrees C. The graphene coating helps to increase the sulfur content and retard the diffusion of polysulfides. The galvanostatic charge-discharge tests show that the graphene-coated sulfur electrode presents good cycling stability. Specific discharge capacities up to 650 mAh g(-1) over 100 cycles at 0.1 C is achieved with enhanced coulombic efficiency, representing a promising cathode material for lithium-sulfur battery. (C) 2013 Elsevier Ltd. All rights reserved.