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

Abstract

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.