Exclusive Se‐O Coordination and Fe‐doping Complementation: A Catalytic Strategy for Enhanced Sulfur Redox in Li‐S Batteries

Exclusive Se‐O coordination and Fe‐doping complementation significantly improve conductivity and modulate the d‐band centers, which strongly anchor polysulfides in bidirectional catalysis and reduce the energy barriers for the Li2S nucleation and dissociation, achieving high‐apacity retention, exceptional rate capability, and stable cycling capability. Abstract Developing efficient electrocatalysts to accelerate redox kinetics and suppress lithium polysulfides (LiPSs) shuttling remains a key challenge for lithium‐sulfur batteries (LSBs). Although transition‐metal‐oxides exhibit strong adsorption for the LiPSs, their application is impeded by sluggish Li2S conversion. Herein, a catalytic strategy is proposed for enhanced sulfur redox in LSBs by complementing exclusive Se‐O coordination and Fe‐doping in spinel Co3O4 (Fe0.1Co2.9O4‐Se) electrocatalyst. This engineered intersecting‐porous nanoarchitecture, fabricated via an etching‐carbonization method, facilitates electron/mass transport and exposes abundant electroactive sites. Fe3+ substitution at octahedral Co3+ sites synergizes with exclusive Se‐O coordination, narrows Co3O4’s bandgap, and elevates the d‐band center, thereby enhancing conductivity and strengthening the LiPSs’ adsorption. Such a design promotes instantaneous nucleation of Li2S and reduces the bidirectional catalytic energy barrier for achieving superior catalytic activity, outperforming Se‐Fe0.1Co2.9O4, where Se in oxygen‐vacancies‐sites coordinates with metal/oxygen ions. Consequently, the S/Fe0.1Co2.9O4‐Se cathode delivers exceptional cycling stability with an ultralow capacity decay rate of 0.1054% per cycle over 500 cycles at 0.5 C. In a pouch cell with a high sulfur loading (6.1 mg cm−2) and lean electrolyte (E/S = 10 µL mg−1), it retains a capacity of 4.8 mAh cm−2 after 40 cycles. This work provides a new catalytic strategy for the design of high‐performance LSBs electrocatalysts. Exclusive Se-O coordination and Fe-doping complementation significantly improve conductivity and modulate the d-band centers, which strongly anchor polysulfides in bidirectional catalysis and reduce the energy barriers for the Li 2 S nucleation and dissociation, achieving high-apacity retention, exceptional rate capability, and stable cycling capability. Abstract Developing efficient electrocatalysts to accelerate redox kinetics and suppress lithium polysulfides (LiPSs) shuttling remains a key challenge for lithium-sulfur batteries (LSBs). Although transition-metal-oxides exhibit strong adsorption for the LiPSs, their application is impeded by sluggish Li 2 S conversion. Herein, a catalytic strategy is proposed for enhanced sulfur redox in LSBs by complementing exclusive Se-O coordination and Fe-doping in spinel Co 3 O 4 (Fe 0.1 Co 2.9 O 4 -Se) electrocatalyst. This engineered intersecting-porous nanoarchitecture, fabricated via an etching-carbonization method, facilitates electron/mass transport and exposes abundant electroactive sites. Fe 3+ substitution at octahedral Co 3+ sites synergizes with exclusive Se-O coordination, narrows Co 3 O 4 ’s bandgap, and elevates the d-band center, thereby enhancing conductivity and strengthening the LiPSs’ adsorption. Such a design promotes instantaneous nucleation of Li 2 S and reduces the bidirectional catalytic energy barrier for achieving superior catalytic activity, outperforming Se-Fe 0.1 Co 2.9 O 4, where Se in oxygen-vacancies-sites coordinates with metal/oxygen ions. Consequently, the S/Fe 0.1 Co 2.9 O 4 -Se cathode delivers exceptional cycling stability with an ultralow capacity decay rate of 0.1054% per cycle over 500 cycles at 0.5 C. In a pouch cell with a high sulfur loading (6.1 mg cm −2 ) and lean electrolyte (E/S = 10 µL mg −1 ), it retains a capacity of 4.8 mAh cm −2 after 40 cycles. This work provides a new catalytic strategy for the design of high-performance LSBs electrocatalysts. Advanced Science, EarlyView.