Sandwich-like graphene-mesoporous carbon as sulfur host for enhanced lithium-sulfur batteries

Graphene-mesoporous carbon/sulfur composites (G-MPC/S) were constructed by melt-infiltration of sulfur into graphene-mesoporous carbon which was synthesized by soft template method. The SEM and BET results of the graphene-mesoporous carbon show that the as-prepared sandwich-like G-MPC composites with a unique microporous-mesoporous structure had a high specific surface area of 554.164 m(2) . g(-1) and an average pore size of about 13 nm. The XRD analysis presents the existence of orthorhombic sulfur in the G-MPC/S composite, which indicates the complete infiltration of sulfur into the pores of the G-MPC. When the graphene-mesoporous carbon/surfur composites (G-MPC/S) with 53.9 wt.% sulfur loading were used as the cathode for lithium-sulfur (Li-S) batteries, it exhibited an outstanding electrochemical performance including excellent initial discharge specific capacity of 1393 mAh . g(-1) at 0.1 degrees C, high cycle stability (731 mAh . g(-1) at 200 cycles) and good rate performance (1038 mAh . g(-1), 770 mAh . g(-1), 518 mAh . g(-1) and 377 mAh . g(-1) at 0.1 degrees C, 0.2 degrees C, 0.5 degrees C and 1 degrees C, respectively), which suggested the important role of the G-MPC composite in providing more electrons and ions channels, in addition, the shuttle effect caused by the dissolved polysulfide was also suppressed.