Linking D-Band Center Modulation with Rapid Reversible Sulfur Conversion Kinetics via Structural Engineering of VS₂.

The rapid catalytic conversion toward polysulfides is considered to be an advantageous approach to boost the reaction kinetics and inhibit the shuttle effect in lithium-sulfur (Li─S) batteries. However, the prediction of high catalytic activity Li─S catalysts has become challenging given the carelessness in the relationship between important electronic characteristics of catalysts and catalytic activity. Herein, the relationships between the D-band regulation of catalysts with reaction kinetics toward polysulfides are described. Through the combination of experimental and theoretical analysis, the opportune upward shift of the D-band center results in a favorable interaction with polysulfides, controlling the adsorption behavior of polysulfides. In addition, the electron regulation achieved by moderately moving up the D-band center further reduces the reaction energy barrier through hybridization with polysulfides. Based on this, a composite catalyst Mo doped VS/rGO as a host material is proposed, which provides impressive long-term cycling stability and superior rate performance. This fundamental knowledge of the inherent connection between the D-band center of the catalyst and the reaction Kinetics of polysulfides offers a rationale for the development of the Li─S catalyst and the modification of its activity.