Ultrathin Fe-Res2 Nanosheets as Electrocatalyst for Accelerating Sulfur Reduction in Li-S Batteries

Lithium-sulfur batteries are promising the next-generation energy storage systems with high theoretical specific capacity. Despite extensive research efforts, it is still challenging to rationally design electrocatalysts with fast kinetics and effective adsorption of polysulfides. Herein, Fe doped ReS 2 (Fe-ReS 2 ) ultrathin nanosheets are prepared as a electrocatalyst to trap the intermediates and accelerate the sulfur reduction reaction kinetic. Density functional theory calculations combine with activation energies in the multistep sulfur reduction reaction reveals that the Fe-ReS 2 considerably reduces the activation energy and optimizes the optimum adsorption strength of polysulfides and catalytic activity. The Fe-ReS 2 /S exhibits highly reversible discharge capacity of 882.3mAh g −1 at 1C with 0.013% capacity fade rate per cycle more than 500 cycles. Moreover, in situ Raman spectroscopy measurements further confirmed that both sulfur reduction and oxidation processes were significantly enhanced by Fe-ReS 2 .