In Situ Non‐Topotactic Reconstruction‐Induced Synergistic Active Centers for Polysulfide Cascade Catalysis

Abstract Most reported catalysts for lithium‐sulfur battery can work for only one of the multiple elementary reactions, thereby resulting in the gradual enrichment of unconverted polysulfides at the catalytic centers and aggravating the shuttle effect. Herein, the concept of cascade catalysis based on a ternary heterostructure, which divides sulfur redox reactions into distinct steps by multiple catalytic centers, is proposed to realize the tandem reduction of Li₂S₈ to Li₂S. As a proof of concept, the ternary heterostructure Na_0.67Ni_0.25Mn_0.75O₂(NNMO)‐MnS₂‐Ni₃S₄ achieved by in situ non‐topotactic electrochemical reconstruction successfully integrates three types of active centers into one structure to achieve cascade catalysis. More specifically, NNMO acts as an adsorption mediator to effectively capture polysulfides, MnS₂ functions better in catalyzing the conversion of polysulfides into Li₂S₄ and Ni₃S₄ demonstrates an enhanced catalytic effect for Li₂S precipitation. This synergistic cascade catalysis originates primarily from the dynamic energy‐level matching between the metal d‐band center and the lowest unoccupied molecular orbital of the polysulfides, affording appropriate molecular orbital hybridization and facile interfacial electron transition and thus endowing favorable sulfur reduction kinetics. Eventually, the NNMO‐MnS₂‐Ni₃S₄/S composite electrode exhibits excellent rate performance and high restraining ability toward the polysulfide shuttle under long cycling, high sulfur loading and low electrolyte conditions.