Carbon-coated core-shell Li2S@C nanocomposites as high performance cathode materials for lithium-sulfur batteriesElectronic supplementary information (ESI) available: Details about materials syntheses, materials characterization, electrode fabrication and Fig. S1-S8. See DOI: 10.1039/c6ta09146f

Li 2 S has made the concept of Li-S batteries much more promising due to the relatively high storage capacity, the possibility of using Li-free anodes and the increase of microstructural stability. However, similar to S, Li 2 S also suffers from an insulating nature and polysulfide dissolution problem. The results presented here show a facile and cost-effective approach by using a plasma sparking and chemical sulfurization process to synthesize core-shell Li 2 S@C nanocomposites. The nanocomposites show a significantly reduced particle size and well-developed core-shell architecture, effectively shortening the Li-ion diffusion distance, enhancing the electronic conductivity and suppressing the dissolution losses of polysulfides. As a result, a much improved rate and cycling performance has been achieved. The method presented in this study offers good opportunities for scaling up the production of high performance cathode materials in a simple and low-cost way to be applied in future generation Li-S batteries. A novel facile and cost-effective approach is proposed based on plasma sparking and chemical sulfurization to synthesize core-shell Li 2 S@C nanocomposites as high performance cathode materials for Li-S batteries.