Origin and Acceleration of Insoluble Li2 S2 -Li2 S Reduction Catalysis in Ferromagnetic Atoms-based Lithium-Sulfur Battery Cathodes

Angew Chem Int Ed Engl. 2023 Jan 2;62(1):e202215414. doi: 10.1002/anie.202215414. Epub 2022 Dec 1.

Abstract

Accelerating insoluble Li2 S2 -Li2 S reduction catalysis to mitigate the shuttle effect has emerged as an innovative paradigm for high-efficient lithium-sulfur battery cathodes, such as single-atom catalysts by offering high-density active sites to realize in situ reaction with solid Li2 S2 . However, the profound origin of diverse single-atom species on solid-solid sulfur reduction catalysis and modulation principles remains ambiguous. Here we disclose the fundamental origin of Li2 S2 -Li2 S reduction catalysis in ferromagnetic elements-based single-atom materials to be from their spin density and magnetic moments. The experimental and theoretical studies disclose that the Fe-N4 -based cathodes exhibit the fastest deposition kinetics of Li2 S (226 mAh g-1 ) and the lowest thermodynamic energy barriers (0.56 eV). We believe that the accelerated Li2 S2 -Li2 S reduction catalysis enabled via spin polarization of ferromagnetic atoms provides practical opportunities towards long-life batteries.

Keywords: Energy Storage; Ferromagnetic Element; Insoluble Li2S2−Li2S Reduction; Lithium-Sulfur Battery; Polar Single-Atom Catalysts.