Quantification of Polysulfide Species in Aqueous Sulfur Thermocell

Abstract

Polysulfide is one of the candidates for the redox pairs for thermocell devices; however, its aqueous solution has never been investigated. Polysulfides are in complex equilibria in an aqueous system, and the open-circuit potential of the solution is made of their mixed potential; thus, the dominant redox equilibrium determines its thermoelectric property. In this paper, the aqueous polysulfide thermocell was fabricated, and the underlying mechanism of the polysulfide thermocell was investigated by electrochemical studies, UV-vis spectroscopy at various temperatures, and thermodynamic calculations.