Spin and orbital manipulation of multiple atomic sites by high-entropy effect for catalyzing cascade sulfur conversion

Abstract

Lithium-sulfur (Li-S) batteries are considered a potential candidate for next-generation energy-dense and sustainable energy storage. However, the slow conversion and severe shuttle of polysulfides (LiPSs) result in rapid performance degradation over long-term cycling. Herein, we report a high-entropy single-atom (HE-SA) catalyst to regulate the multi-step conversion of LiPS to attain a high-performance Li-S battery. Both the density functional theory calculations and the experimental results prove that the Fe atomic site with high spin configurations strongly interacts with Li₂S₄ through d-p and s-p synergistic orbital hybridization which facilitates the reduction of LiPS. Moreover, S-dominant p-d hybridization between Li₂S and a high-spin Mn site weakens the Li–S bond and facilitates the rapid sulfur evolution reaction. Consequently, the Li-S battery with a bifunctional HE-SA catalyst shows an ultralow capacity decay of 0.026 % per cycle over 1900 cycles at 1 C. This work proposes a high-entropy strategy for sculpting electronic structures to enable spin and orbital hybridization modulation in advanced catalysts toward long-cycling Li-S batteries.