Heterostructure‐Driven D‐Band of MoS ₂ Engineering Catalytic Polysulfide Conversion in Lithium–Sulfur Batteries

Abstract As a pivotal strategy, d‐band center engineering of catalytic hosts addresses polysulfide adsorption‐catalysis issues through electronic‐structure‐level mediation for lithium‐sulfur batteries (LSBs). However, identifying active sites in heterostructured hosts and regulating their intrinsic d‐band centers has been challenging. Herein, the yolk–shell MoS ₂ ‐MoSe ₂ heterostructure (C@MoS ₂ ‐MoSe ₂ ) is constructed. By adjusting proportions between MoS ₂ (x) and MoSe ₂ (y), the relationships among built‐in electric field, d‐band center, and catalytic performance are addressed. In C@ x MoS ₂ ‐ y MoSe ₂ , increasing MoSe ₂ enhances the field, with the d‐band center shifting up, then down. C@3MoS ₂ ‐1MoSe ₂ shows optimal rate performance, confirming appropriate field and d‐band center are crucial for polysulfide conversion. It delivers 586.2 mAh g ⁻¹ at 5C, with 0.04% capacity fade per cycle over 1000 cycles at 4C. It revealed that MoS ₂ domains serve as an active center, exhibiting stronger Li‐S binding and faster redox kinetics. Moreover, interfacial charge redistribution strengthens Mo‐S d‐p orbital hybridization, shifting the d‐band center toward the Fermi level and facilitating polysulfide catalysis. This optimization brings the d‐orbital closer to the Fermi energy level, thereby facilitating the enhanced adsorption and conversion of polysulfides by the catalytic substrate. It is believed that this work elucidates the structure‐interface‐performance correlations for sulfur hosts in high‐rate LSBs.