Synthesis and electrochemical performance of S/mesoporous carbon microsphere-MoS₂ cathode materials

The commercial uses of Li-S batteries are still greatly limited by a number of obstacles such as the insulating nature of sulfur and its discharge products, the shuttling of intermediate polysulfides and the large volume change of sulfur during cycling. Here, we attached polar MoS₂ to a well-developed mesoporous carbon microsphere (MCM) framework and used this as a highly efficient host for the sulfur cathode. Compared with a S/MCM cathode, the S/MCM-MoS₂ cathode provided a higher discharge capacity, improved cycling stability and rate performance with an optimum MoS₂ content of 12.4 wt.%. MoS₂ is electrochemically active within the working voltage range of the sulfur cathode, which contributes extra capacity to the sulfur cathode with a stable cycling performance without loss of capacity in a 1 M LiTFSI electrolyte. The replacement of some of the electrochemically inactive carbon with MoS₂ also increases the overall energy density. The exploration of such an electrochemically active host material may provide a new possibility for improving the electrochemical performance of Li-S batteries.