Electronic Metal-Support Interactions in Atomically Dispersed Fe(III)-VO₂ Nanoribbons for High-Performance Lithium-Sulfur Batteries

Lithium-sulfur (Li-S) batteries have attracted wide attention as high-energy-density energy storage devices, but their practical applications are hindered by the severe shuttle effect and sluggish kinetics of lithium polysulfides (LiPSs). To address these challenges, polar mediators are employed to chemisorb and catalyze LiPSs, but most of them suffer from low electronic conductivity and poor catalytic activity. Here, a novel strategy is reported to enhance both properties by dispersing Fe(III) atoms in VO2 nanoribbons(Fe-VO2), creating electronic metal-support interactions (EMSI) that modulate the electronic structure and charge transfer of VO2. Theoretical calculations reveal that EMSI lowers the energy barrier for the decomposition of Li2S from 1.60 to 1.32 eV and increases the electronic conductivity of VO2. Fe doping reduces the Li-ions diffusion barrier from 1.42 eV in VO2 to 0.99 eV in Fe-VO2. The Fe-VO2 catalyst shows strong adsorption and fast converstion of LiPSs, resulting in high energy density and long cycling life of Li-S batteries. The cathode with Fe-VO2 maintains a higher capacity retention of 67% after 500 cycles at 1 C, compared with 52.4% and 53.6% for the carbon black based cathode and VO2 based cathode, respectively. This work demonstrates the potential of EMSI for designing efficient catalysts for Li-S batteries and provides new insights into the electronic structure engineering of polar mediators.