Antimonene allotropes α- and β‑Phases as promising anchoring materials for Lithium−Sulfur batteries

Abstract

In a quest to mitigate the undesirable shuttling effect that hampers the performance of Li−S batteries, we adopted firstprinciples calculations to study the anchoring mechanism of lithium polysulfides on antimonene phases, i.e., α-Sb and β-Sb. The anchoring mechanisms of LiPSs on α-Sb and β-Sb were studied through calculations of binding energy, charge transfer, and vertical binding distances from the monolayer to LiPSs. The results indicated that pristine α-Sb and β-Sb showed significant physisorption/chemisorption interactions toward LiPSs due to the considerable Eb values (0.71−1.68 and 0.96−2.07 eV, respectively). Meanwhile, with single Sb vacancy, the binding strength was enhanced (0.83−2.91 eV) for the β-Sb monolayer. Furthermore, we substituted the Sb atom with the Sn/Te atom and found stronger Eb (1.32−5.69 and 0.45−4.81 eV). All these bindings of LiPSs were much stronger than their interactions with those of electrolytes (DME/DOL) (Eb values: 0.20−1.16 and 0.17−1.07 eV). Also, we investigated the redistribution of electrons and the influence of electronic states near the Fermi level in DOS for LiPSs on α-Sb and β-Sb. Our findings suggest that pristine and defected β-Sb monolayers could be an excellent anchoring material for Li−S batteries