An interwoven MoO3@CNT scaffold interlayer for high-performance lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries have attracted increasing attention in the past few decades due to the extremely high energy density, low cost and non-toxicity of sulfur. But the poor conductivity of sulfur and particularly the migration of soluble polysulfides greatly hindered the application of Li-S batteries. Herein, we report a novel strategy for trapping polysulfides by coating a separator with an interwoven framework of MoO3 nanorods and carbon nanotubes (CNTs) as the interlayer in Li-S batteries. The interwoven scaffold-like MoO3@CNT network provides abundant conducting channels and pathways for ions and electrons, leading to high rate capabilities. While the MoO3@CNT interlayer acting as a barrier effectively mitigates the shuttle effect in Li-S batteries, the MoO3 nanorods enfolded by CNTs uniformly play an important role in immobilizing sulfur species. Consequently, the electrochemical performances of Li-S batteries are improved, giving rise to higher capacities with a longer cycling life. The Li-S batteries with the MoO3@CNT interlayer can deliver a specific capacity of 755 mA h g(-1) after 200 cycles at a current density of 0.3C, and show an excellent rate capability with a capacity of 655 mA h g(-1) at 3C.