Carbon-coated core–shell Li2S@C nanocomposites as high performance cathode materials for lithium–sulfur batteries†
Li2S 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, Li2S 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 Li2S@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.