Facile Preparation and Electrochemical Properties of Carbon-Enfolded Sulfur Particles for Li-S Battery Application

A rational S/C composite material design is proposed for use as a cathode in lithium-sulfur (Li-S) batteries. The S/C composites were prepared using three structured carbon materials of multi-walled carbon nanotubes (MWCNTs), acetylene black (AB), and graphene nanosheets (GNS). The three-dimensional mesh structure of the S/CNT composite reduced the loss of active material compared to the other S/C composites. In addition, this structure improved the electrochemical properties of the battery because Li+ was more effectively diffused through the pathways established by the mesh. As a result, the S/CNT electrode exhibited superior performance with a high discharge capacity of 1166 mAh g(-1) at the first cycle and 806 mAh g(-1) after 40 cycles, almost 300 mAh g-1 higher than that obtained with the S/AB electrode. Good cycle stability of 94%, based on calculations from 2 to 40 cycles, was observed in the S/CNT electrode. (C) 2015 The Electrochemical Society.