g-C3N4/MoO3 composite with optimized crystal face: A synergistic adsorption-catalysis for boosting cathode performance of lithium-sulfur batteries.

[Display omitted] The commercial application of lithium-sulfur batteries (LSBs) has been seriously hindered by the shuttle effect of lithium polysulfides (LiPSs) and their slow redox kinetics. In this work, g-C 3 N 4 /MoO 3 composed of graphite carbon nitride (g-C 3 N 4) nanoflake and MoO 3 nanosheet is designed and applied to modify the separator. The polar MoO 3 can form chemical bond with LiPSs, effectively slowing down the dissolution of LiPSs. And based on the principle of "Goldilocks", LiPSs will be oxidized by MoO 3 to thiosulfate, which will promote the rapid conversion from long-chain LiPSs to Li 2 S. Moreover, g-C 3 N 4 can promote the electron transportation, and its high specific surface area can facilitate the deposition and decomposition of Li 2 S. What's more, the g-C 3 N 4 promotes the preferential orientation on the MoO 3 (0 2 1) and MoO 3 (0 4 0) crystal planes, which optimizes the adsorption capacity of g-C 3 N 4 /MoO 3 for LiPSs. As a result, the LSBs with g-C 3 N 4 /MoO 3 modified separator with a synergistic adsorption-catalysis, can achieve an initial capacity of 542 mAh g−1 at 4C with capacity decay rate of 0.0053% per cycle for 700 cycles. This work achieves the synergy of adsorption and catalysis of LiPSs through the combination of two materials, providing a material design strategy for advanced LSBs. [ABSTRACT FROM AUTHOR]