Effect of additives on the properties of electrolyte for vanadium redox battery

The solubility and stability of vanadium ion in vanadium sulfate solutions were improved by adding alkali metal sulfate, alkali metal oxalate, urea and glycerin respectively. The stability mechanism of the electrolyte with the additives was discussed. The conductivity of electrolytes with the additives and without additives were measured. The results show that the conductivity of electrolyte with additive less than 3% is hardly changed compared with the electrolyte without additives. The cyclic voltammogram investigation displays no adverse effect of the additives on the vanadium redox reaction in vanadium sulfate solution.