Low temperature, high energy density non-aqueous Redox Flow Battery

A non-aqueous vanadium acetylacetonat redox flow battery in a solvent mixture consisting of acetonitrile, 1,3-dioxolane and dimethyl sulfoxide was investigated at two different temperatures. It was shown, that the reversibility of the both redox processes of V(acac)<inf>3</inf> almost did not changed even at 248.15 K compared to the room temperature. But due to low temperature, increase of viscosity led to an increased electrolyte resistance and low rate constant. On the other hand experiments in a charge-discharge test cell achieved energy and coulombic efficiencies that are similar to the room temperature values.