Synergistic effect of Li2S@Li3PS4 nanosheets and MXene for high performance lithium-sulfur batteries

Lithium sulfide (Li2S) is a promising cathode material for Lithium-sulfur (Li–S) batteries, but poor conductivity and electrochemical reactivity seriously hinders its applications. Herein, Ti3C2 nanosheet (TNS) supported core-shell nano-Li2S@Li3PS4 composite (NLi2S@LPS) is comprehensively designed to tackle these challenges. It displays fast Li+/e− transport kinetics, low energy barrier and high catalytic activity for the electrochemical redox reactions, which are derived from the synergistic effect of nano-sized Li2S, Li3PS4 coating and catalytic MXene (Ti3C2) components. The NLi2S@LPS/TNS composite electrode exhibits high utilization ratio of the active materials with low polarization and robust rate capability for charge/discharge, resulting in improved cycling stability for Li–S batteries. The Li–S batteries with NLi2S@LPS/TNS electrode have a capacity retention rate of 77% after 300 cycles of charge and discharge at 0.5C rate, corresponding to an average decay rate of 0.08% per cycle.