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.