p-Block Ge Dual-Atom Catalysts with Enhanced Sulfur Hybridization for Bidirectional Catalysis in High-Performance Li-S Batteries

Abstract

Single-atom catalysts (SACs) have been extensively utilized in lithiumsulfur (Li-S) batteries through d-p orbital hybridization; however, they still face challenges related to sluggish reaction kinetics and unresolved polysulfide shuttle effects. In this study, we propose a novel design for p-block Ge-based catalysts and systematically investigate the interaction mechanism between the catalysts and the lithium polysulfides (LiPSs). Our theoretical results reveal that the rearrangement of electrons in the s/p hybrid orbital of Ge DACs induce stronger coupling between s/p hybrid orbital of Ge atoms and the p orbitals of S atoms in LiPSs, while avoiding the risk of sulfur poisoning. Remarkably, the N 2 -coordinated Ge DAC demonstrates exceptional performance in facilitating simultaneous dual-side adsorption and catalytic conversion of LiPSs for the sulfur reduction reaction (SRR). Moreover, introducing B dopants near the DACs promotes Li + detachment and migration by creating additional adsorption sites, thereby reducing the Li 2 S decomposition barrier to ~ 0.8 eV and consequently boosting SER performance. This work presents a new avenue for designing catalysts with enhanced catalytic efficacy towards LiPSs.