Modulating of MoSe2 functional plane via doping-defect engineering strategy for the development of conductive and electrocatalytic mediators in Li-S batteries

The lithium polysulfide shuttle and sluggish sulfur reaction kinetics still pose significant challenges to lithium-sulfur (Li-S) batteries. The functional plane of Fe-MoSe2@rGO nanohybrid with abundant defects has been designed and applied in Li-S batteries to develop the functional separator and multi-layer sulfur cathode. The cell with a functional separator exhibits a retention capacity of 462 mAh g-1 after the 1000th at 0.5 C and 516 mAh g-1 after the 600th at 0.3 C. Even at low electrolyte conditions (7.0 lL mgsulfur-1 and 15 lL mgsulfur-1 ) under high sulfur loadings (3.46 mg cm-2 and 3.73 mg cm-2), the cell still presents high reversible discharge capacities 679 and 762 mAh g-1 after 70 cycles, respectively. Further, at sulfur loadings up to 8.26 and 5.2 mg cm-2, the cells assembled with the bi-layers sulfur cath-ode and the tri-layers sulfur cathode give reversible capacities of 3.3 mAh cm-2 after the 100th cycle and 3.0 mAh cm-2 after the 120th cycle, respectively. This research not only demonstrates that the Fe-MoSe2@rGO functional plane is successfully designed and applied in Li-S batteries with superior electro-chemical performances but also paves the novel way for developing a unique multi-layer cathode tech-nique to enhance and advance the electrochemical behavior of Li-S cells at a high-sulfur-loading cathode under lean electrolyte/sulfur (E/S) ratio.(c) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

This research introduces a functional plane of Fe-MoSe2@rGO nanohybrid with abundant defects for the development of functional separator and multi-layer sulfur cathode in Li-S batteries. It demonstrates superior electrochemical performance and offers a novel approach for enhancing the behavior of Li-S cells at high-sulfur-loading cathodes under lean electrolyte/sulfur (E/S) ratio.