Cation‐substitution‐induced d – p hybridization modulation in catalytic metal sulfides for lithium–sulfur batteries

Abstract Catalyzing polysulfide conversion is vital to mitigate shuttle effects and boost reaction kinetics in Li–S batteries (LSBs). Transition metal dichalcogenides serve as efficient catalysts due to their strong polarity and adjustable electronic structures; however, their practical application remains challenged by sluggish conversion kinetics and insufficient lithium polysulfides (LiPSs) adsorption. Here, we propose a cation substitution strategy which induces lattice distortion for d – p hybridization modulation in cobalt disulfide (CoS 2 ) for realizing improved sulfur redox kinetics and polysulfide adsorption. The electronic structure modulation mechanism is revealed by rationally tuning the d – p hybridization degree via doping various cations (Cu 2+ , Ni 3+ , and Mn 3+ ). Among these cations, the Ni incorporation into CoS 2 lattice induces symmetric and moderate lattice distortion and manipulates the d ‐band center of Co sites, resulting in enhanced d – p hybridization and improved mass transfer and adsorption of LiPSs. Consequently, the Ni‐doped sulfur host exhibits an ultralow decay rate of 0.063% per cycle after 500 cycles at 2 C, and even at a demanding sulfur loading of 6.38 mg cm −2 , it retains a high reversible capacity of 501 mAh g −1 after 60 cycles. The pouch cell demonstration further substantiates its high practical potential of a considerable 203 Wh kg −1 energy density, delivering stable cycling performance with 73% capacity retention after 100 cycles. This work brings valuable design considerations in d – p hybridization modulation for advancing catalytic sulfur redox reactions in LSBs and paves the way for their practical applications as next‐generation energy storage systems.