Antimonene Allotropes α- and β-Phases as Promising Anchoring Materials for Lithium-Sulfur Batteries

In a quest to mitigate the undesirable shuttling effect that hampers the performance of Li-S batteries, we adopted first-principles 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 E_b 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 E_b (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) (E_b 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.