Cooperative Catalysis of Polysulfides in Lithium-Sulfur Batteries through Adsorption Competition by Tuning Cationic Geometric Configuration of Dual-active Sites in Spinel Oxides

Angew Chem Int Ed Engl. 2023 Feb 13;62(8):e202216286. doi: 10.1002/anie.202216286. Epub 2023 Jan 16.

Abstract

Fundamentally understanding the structure-property relationship is critical to design advanced electrocatalysts for lithium-sulfur (Li-S) batteries, which remains a formidable challenge. Herein, by manipulating the regulable cations in spinel oxides, their geometrical-site-dependent catalytic activity for sulfur redox is investigated. Experimental and theoretical analyses validate that the modulation essence of cooperative catalysis of lithium polysulfides (LiPSs) is dominated by LiPSs adsorption competition between Co3+ tetrahedral (Td) and Mn3+ octahedral (Oh) sites on Mn3+ Oh -O-Co3+ Td backbones. Specifically, high-spin Co3+ Td with stronger Co-S covalency anchors LiPSs persistently, while electron delocalized Mn3+ Oh with adsorptive orbital (dz 2 ) functions better in catalyzing specialized LiPSs conversion. This work inaugurates a universal strategy for sculpting geometrical configuration to achieve charge, spin, and orbital topological regulation in electrocatalysts for Li-S batteries.

Keywords: Adsorption Competition; Electrocatalysts; Geometrical Configuration; Li−S Batteries; Spinel Oxides.