Interfacial competition between a borophene-based cathode and electrolyte for the multiple-sulfide immobilization of a lithium sulfur battery

Abstract

The practical applications of lithium–sulfur batteries (LSBs) are mainly hindered by the poor conductivity of the sulfur cathode, polysulfide shuttle and volumetric variation during cycling. To this end, host materials with high conductivity and excellent polysulfide absorbability are extensively employed as the loading scaffolds for sulfur in LSBs. In the present study, three types of borophene nanosheets with metallicity are theoretically evaluated as the hosts for sulfur cathodes. The polarization of surfaces, conductivity, polysulfide immobilization, and the interfacial competition between borophenes and electrolytes are particularly discussed. The strong binding of polysulfides onto borophenes will block the shuttle effect of polysulfides, due to the strong Coulomb interactions between the B and S atoms, even considering the competitive effect of the electrolytes and under a high sulfur loading. The calculated results clearly indicate that borophene-based materials with polarized and highly conductive surfaces hold great promise for LSBs.