Atomistic study of the physical properties of sulfonium-based ionic liquids as electrolyte for supercapacitors

Abstract

Sulfonium-based ionic liquids have attracted attention because of their properties as relatively low viscosities, high conductivities and wide electrochemical window. These properties make them attractive for electrochemical applications. As far as we know, there are no studies of molecular dynamics for this class of ionic liquids nor for their use as electrolytes in supercapacitors. Here we used molecular dynamics simulations to describe at atomic level de structural, dynamical and electrical properties of three sulfonium cations ([S221], [S222] and [S223]). combined the anion [NTf2]. Viscosities and ionic conductive were found in excellent agreement with experimental results. Graphene-based supercapacitor was modeled to evaluated how the composition of electrolytes affects the performance of an electrochemical device. Overall, our simulations reveal that the electrical properties of the evaluated electrolytes are very similar and that, although the liquids have different viscosities and ionic conductivities, such differences are not sensitive when examining the relative performance of the supercapacitors.