Facile synthesis of Li2S@C composites as cathode for Li-S batteries

Lithium sulfide (Li2S) provides a promising route for lithium storage due to high theoretical specific capacity (1166 mAh g(-1)). The electrochemical performance of Li2S can be significantly enhanced by forming Li2S-carbon composites with the introduction of carbon. However, the complex synthesis method of Li2S carbon composites restrains the large-scale productivity. Herein, we propose a facile route to prepare carbon coated Li2S-carbon nanotube composites (Li2S@C-CNT) via spray drying and heat treatment, which is a low-cost and large-scale method for facile synthesis of Li2S-carbon composites. For the Li2S@C-CNT composites, Li2S nanoparticles are contacted with surrounding particles due to the 3D CNTs framework. The novel construction not only suppresses the diffusion of polysulfides during cycling, but also remarkably accelerates the transport of electron and ion, resulting in a high specific capacity (1100 mAh g(-1)) and good cycling performance. The rational designed architecture and good electrochemical performance of Li2S@C-CNT will pave the avenue for realizing high energy density of Li2S-based batteries. (C) 2018 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.