Enhancing the Bidirectional Reaction Kinetics of Polysulfides by Mott-Schottky-like Electrocatalysts with Rich Heterointerfaces

Designing a well-functional host material to effectively overcome all of the energy barriers in the overall 16-electron sulfur conversion reaction remains elusive in current Li-Sbatteries (LSBs). Herein, by an advantageous multifunctionalintegration of immobilization and conversion capability for lithiumpolysulfides (LiPSs), an N-doped carbon nanobelt (NCB) seededwith ultrafine Mo nanoparticles and MoO2/Mo2C heterostructure(MH-NCB) is prepared for thefirst time. The target sample ofMH-NCB fulfills the smooth bidirectional electrocatalysis of sulfurspecies in LSBs by the coexistence of enriched heterointerfacesamong MoO2/Mo2CandsimilarMott-Schottkycatalystsformed between ultrafine metallic Mo and NCB due to differencein their work functions. The as-obtained MH-NCB harvests animpressive rate capability (593.9 mAh g-1at 3C) and favorable cycling stability (724.9 mAh g-1after 500 cycles at 1C) at a high sulfur content of 70.2 wt % in the composite

Automated summary

This study designs an N-doped carbon nanobelt (NCB) with advantageous multifunctional integration of immobilization and conversion capability for lithium polysulfides (LiPSs), and prepares a MH-NCB material for bidirectional electrocatalysis of sulfur species in lithium-sulfur batteries (LSBs). The MH-NCB material achieves smooth electrocatalysis by the coexistence of enriched heterointerfaces among MoO2/Mo2C and similar Mott-Schottky catalysts formed between ultrafine metallic Mo and NCB. The as-obtained MH-NCB material exhibits impressive rate capability and favorable cycling stability in high sulfur content composite.