Surface Electron Reconstruction of Catalyst Through Alloying Strategy for Accelerating Sulfur Conversion in Lithium-Sulfur Batteries

Alloy catalyst is considered to be an important strategy to solve the shuttle effect and sluggish kinetics of lithium-sulfur batteries (LSBs). However, the effect of the electronic structure of the alloy catalyst on the sulfur conversion process has not been effectively analyzed. In this paper, based on alloying strategy, the electronic structure of such a FeCoNi catalyst is regulated and optimized, and the sulfur adsorption configuration and catalytic conversion process are defined. The in situ Raman spectroscopy and the density functional theory (DFT) are employed to deeply understand the catalytic mechanism of such a sulfur conversion. A cell with FeCoNi modified separator delivers an ultra-low capacity attenuation of 0.056% per cycle over 1000 cycles at 3 C. The outstanding anti-self-discharge performance of 8.1% over 7 days is also achieved. Furthermore, the obtained cell with a high sulfur loading of 9.7 mg cm-2 and lean electrolyte of 5.6 mu L mgs-1 exhibits 81% capacity retention after 100 cycles, providing a research prospect for the practical application of lithium-sulfur batteries. Based on the intrinsic electronic structure of the alloy catalyst, the surface electronic reconstruction process of the alloy catalyst is analyzed, and its catalytic mechanism in the sulfur conversion process is elucidated, which provides a new idea for the development of alloy catalyst and lithium sulfur battery. image