WSe2 Flakelets on N-Doped Graphene for Accelerating Polysulfide Redox and Regulating Li Plating.

The practical application of lithium-sulfur batteries is still limited by the lithium polysulfides (LiPSs) shuttling effect on the S cathode and uncontrollable Li-dendrite growth on the Li anode. Herein, elaborately designed WSe2 flakelets immobilized on N-doped graphene (WSe2 /NG) with abundant active sites are employed to be a dual-functional host for satisfying both the S cathode and Li anode synchronously. On the S cathode, the WSe2 /NG with a strong interaction towards LiPSs can act as a redox accelerator to promote the bidirectional conversion of LiPSs. On the Li anode, the WSe2 /NG with excellent lithiophilic features can regulate the uniform Li plating/stripping to mitigate the growth of Li dendrite. Taking advantage of these merits, the assembled Li-S full batteries exhibit remarkable rate performance and stable cycling stability even at a higher sulfur loading of 10.5 mg cm-2 with a negative to positive electrode capacity (N/P) ratio of 1.4 : 1.