Junhyuk Ji, Sangyeon Won, Jaehyeong Yu, 문누리, Dongwoo Kim, Junbeom Maeng, Won Bae Kim
ABSTRACT Although chalcogenide‐based catalysts offer significant potential for enhancing lithium‐sulfur (Li‐S) battery performance, the absence of reliable descriptors linking the d ‐band center to sulfur conversion kinetics hinders the rational design of electrochemical systems. Herein, we address this limitation by engineering a catalytic interlayer through modification of 2H‐MoS 2 electronic structure, achieved via substitutional doping of n‐type Co/Fe transition metals (TM) at Mo sites. Comprehensive findings elucidate that such doping initiates a distinct S‐mediated d ‐ p hybridization involving Mo 4 d— S 3 p— TM 3 d orbitals, thereby modulating electronic density of states near the Fermi level. Specifically, in the CoFe‐MoS 2 @carbon paper (CP) interlayer, synergistic effect of co‐doping with two different TM drives optimized downshift of the Mo 4 d ‐band center to intermediate energy states, fostering moderate catalyst‐reactant interaction. Furthermore, the simultaneously lowered S 3 p ‐band center enhances the degree of d ‐ p orbital overlap. These electronic redistributions enhance both electrical and ionic conductivity, thereby facilitating accelerated redox kinetics with reduced activation energy, while mitigating the shuttle effect and promoting uniform Li 2 S deposition. Consequently, the assembled cell delivers outstanding stability with a low decay rate of 0.024% for 2000 cycles even at 10C. This work emphasizes that a balanced d ‐band center is key to achieving highly active chalcogenide‐based materials for advanced Li‐S batteries.