Matching <i>d‐p</i> Energy Levels Between High‐Entropy Alloy Catalysts and Chalcogen Cathodes for All‐Solid‐State Batteries

ABSTRACT All‐solid‐state batteries employing chalcogen cathodes have emerged as promising candidates for next‐generation energy storage systems owing to their high theoretical energy densities. However, their practical application is severely hindered by sluggish solid‐state reaction kinetics. High‐entropy alloy (HEA) catalysts, featuring rich active sites, diverse atomic environments, and strong electronic synergistic effects, offer a compelling strategy to address this challenge. Herein, we propose a d‐p energy‐level‐matching strategy by aligning the d band of the HEA catalyst with the p band of the chalcogen cathode to enhance catalyst–cathode electronic compatibility and regulate solid‐state catalytic conversion reactions. Theoretical calculations reveal that, among the investigated HEA catalysts (FeCoNiCuX, X = Cr, Mo, and W), FeCoNiCuCr exhibits the smallest d‐p energy level gap with chalcogen cathodes, especially Se‐based chalcogenides. Such a well‐matched electronic structure maximizes interfacial charge transfer and effectively accelerates the solid–solid conversion kinetics. As a result, the optimized Se‐based electrode delivers a highly stable reversible capacity of 657 mAh g −1 after 1800 cycles at 2C. This work elucidates the key catalytic role of energy‐level‐matching catalysts for all‐solid‐state chalcogen‐based batteries and provides insight into regulating catalyst–cathode interactions to overcome the kinetic limitations in all‐solid‐state batteries with conversion‐type cathodes.