A global design principle for polysulfide electrocatalysis in lithium–sulfur batteries—A computational perspective

Widespread commercialization of high-energy-density lithium–sulfur (Li–S) batteries is difficult due to the lithium polysulfide, Li2Sn (n = 4, 6, 8), shuttle effect. Efficient adsorption/conversion species on an electrocatalytic surface can suppress Modeling adsorption using density functional theory (DFT) calculations has contributed significantly toward understanding their anchoring mechanism at a surface. Different surfaces show unique range binding energies for faster adsorption/reaction kinetics. To predict optimum energy zone, systematic DFT study performed transition-metal sulfide (TMS) including TiS2, VS2, NbS2, MoS2, WS2, and SnS2. The investigation revealed that geometric properties site possibly regulate species. A geometry parameter, Gscore, defined as function bond length number lithium-atom interactions between design principle extended sulfur-deficient (TMSs-x) edge-exposed (TMS(100)) surfaces. Gscore predicts most effective zone distinctive these materials—TMS (1.7–2.1 eV/Gscore ≥ 2.0), TMSs-x (2.0–2.8 2.1), TMS(100) (2.5–3.2 1.09).