Targeted Modulation of <i>d</i> ‐Band Center in MoS ₂ Interlayer With n‐Type Co/Fe Dopants Accelerating Sulfur Reaction Kinetics in Lithium‐Sulfur Batteries

Abstract

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.