《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 dryingand 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 novelconstruction not only suppresses the diffusion ofpolysulfides 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.