A Universal Quasi-Atom Interaction Model and Application in Designing Single-Atom Catalysts for Alkali-Metal Chalcogenide Batteries.

Wang, Chenhui; Lin, Wei; Hu, Hui; Li, Yan; Pan, Feng; Wang, Chengxin · Adv Mater · 2026

basic_science · Level V

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Abstract

A deep understanding of reactant adsorption behaviors is crucial for unraveling structure-activity relationships and identifying simple descriptors for the kinetics of multi-electron redox reactions, such as the sulfur redox process in Li-S batteries (LSBs). Recently, the "10-electron rule" for evaluating the adsorption strength of single atoms (E<sub>ads</sub>) has been established for free-atom-like single-atom alloys (SAAs). However, our density-functional theory calculations show that this rule is unfeasible for single-atom catalysts (SACs) with metal centers covalently coordinated by nonmetal atoms. Herein, we proposed a new 18-electron rule for covalent SACs by establishing the quasi-atom interaction model (Q-AIM), which interprets the U-type behavior of E<sub>ads</sub>(S) dominated by antibonding-orbital filling. Additional calculations demonstrate that E<sub>ads</sub>(S) can serve as an efficient descriptor of the kinetics of sulfur redox involving multiatom polysulfides. Then, guided by the efficient predictor and Q-AIM, we employed machine learning to screen ∼800,000 candidate SACs. Ultimately, we obtained over 400 and 8000 promising SACs for sulfur evolution and sulfur reduction, respectively. Furthermore, E<sub>ads</sub>(S) can be extended to predict the catalytic performance of SACs in Li/Na/K-S/Se batteries. This work not only simplifies complex multi-electron processes to single-atom adsorption energy but also establishes a link between occupied electronic states and the catalytic performance of SACs.