The Role of Long-Range Interactions Between High-Entropy Single-Atoms in Catalyzing Sulfur Conversion Reactions

Abstract

Sulfur conversion reactions are the foundation of lithium–sulfur batteries but usually possess sluggish kinetics during practical battery operation. Herein, a high-entropy single-atom catalyst (HESAC) is synthesized for this process. In contrast to conventional dual-atom catalysts that form metal–metal bonds, the center metal atoms in HESAC are not bonded but exhibit long-range interactions at a sub-nanometer distance (<9 Å). The synergistic effect between the long-range interactions and entropy changes enables the regulation of d- and π-electron states. This alteration in the electronic structure improves the adsorption and electronic conductivity of intermediate polysulfides, thereby accelerating their conversion kinetics. Consequently, this leads to a significant enhancement in specific capacities by ≈40% at high rates compared to single-atom catalysts. The resulting lithium–sulfur battery with HESAC demonstrates a remarkable areal capacity of 3.4 mAh cm⁻² at 10 C. These findings provide valuable insights into the design principle of metal atom catalysts for electrochemical reactions.