The Influence of Some Electrolyte Additives on the Electrochemical Performance of Fe/Fe2+ Redox Reactions for Iron/Iron Redox Flow Batteries

For the application in Fe/Fe-Redox-Flow-Batteries some important factors concerning the composition of the electrolyte and the influence of temperature on the properties of half-cell reactions were investigated. In contrast to previous investigations, the measurements were performed more realistically on deposited iron and by means of linear sweep voltammetry. Since the distinction between cathodic iron deposition and hydrogen generation is not possible by convention, with quantitative stripping analysis on a rotating disk electrode, partly a method was used to distinguish between these two reactions. The investigations were carried out at temperatures up to 80 C, with addition of 10 mM of chlorides of Bi, Cu, In, Pb, Sn, Tl, Cd, Sb and Hg and different supporting salts of NH4+, Li+, K+. Na+, Cs+, Mg2+ and Al3+.