Investigation of the Chemisorption-Catalysis Behavior of Sulfur Species on the Electrocatalysts Designed by Co-regulation Strategy of Anions and Cations.

Abstract

Li-S batteries possess high energy density and have been one of the most promising energy storage systems. For sulfur cathodes, the electrochemical performance is still seriously hindered by the polysulfide shuttling and sluggish conversion kinetics. It has been demonstrated to be one effective strategy to address the above issues via designing electrocatalysts with robust affinity and catalytic capacity towards polysulfides. However, it is still a great challenge to rapidly and economically discover high-performance electrocatalysts. Herein, using density functional theory calculation, we studied the chemisorption-catalysis behavior of sulfur species on a series of electrocatalysts (MCo2 X4 , M=Co, Zn, Cu, Ni, Fe, and Mn, X=O, S, and Se) to assess the effect of the anions and cations co-regulation on their electronic structure, chemisorption behavior, and catalytic property. FeCo2 Se4 and CuCo2 Se4 combined appropriate chemisorption with superior electronic conductivity and sulfur reduction catalytic capacity have been predicted as novel electrocatalysts for high-performance Li-S batteries. This study gives theoretical guidance for rapid discovery of high-efficient electrocatalyst to boost the electrochemical performance of sulfur cathodes.