CoSe 2 -modified N-doped carbon polyhedron composites containing carbon nanotubes as effective anchors for lithium polysulfides

The slow electrochemical dynamics, shuttle of lithium polysulfides (LiPSs) and uncontrollable growth of Li dendrite seriously affect the cycling performance of Li-S batteries (LSBs). Herein, CoSe 2 -modified N-doped carbon polyhedron composites containing carbon nanotubes (CoSe 2 @NC-CNT) were successfully prepared and used as a sulfur host for LSBs. The CoSe 2 @NC-CNT can limit the volume expansion, inhibit the shuttle of LiPSs, and improve the electronic conductivity of sulfur cathode. The CoSe 2 @NC-CNT/S electrode delivered excellent electrochemical performance, it can maintain a specific capacity of 428 mAh/g at 1 C after 500 cycles. Even at 3 C, a high specific capacity of 713 mAh/g can be obtained. This work provides a new idea for the research of high performance sulfur cathodes for LSBs.