Investigation on manganese (Mn2+/Mn3+) – vanadium (V2+/V3+) redox flow battery
Tao Hong
School of Electronic and Information Engineering,
Beihang University, Beijing, China Fangqin Xue * Department of Physical Chemistry, University of Science and Technology Beijing, Beijing, China Abstract: A novel Mn2+/Mn3+– V2+/V3+redox flow battery has been designed. The electrochemical response of high concentration Mn2+/Mn3+ couple in H2SO4 solution were investigated via cyclic voltammetry, steady polarization curve, electrochemical impedance spectroscopy, and chargedischarge experiments. The electrochemical and the kinetic parameters for anodic oxidation of Mn2+ and cathodic reduction of Mn3+ were measured. Performance of a RFB employing Mn2+/Mn3+ couple as anolyte active species and V2+/V3+ as catholyte ones was evaluated with constant-current charge-discharge tests. When the current density varies from 20 to 80 mA cm-2, the average coulombic efficiency varies from 81.5% to 92.5% and the voltage efficiency varies from 93.5% to 85.3%. Accordingly the whole energy efficiency varies from 76.2% to 81.2%. Energy efficiency is about 20% higher than that of the all-vanadium battery and average discharge voltage is 1.66 V, which is about 14% higher than that of the all-vanadium battery. The energy density is calculated to be 40.8 Wh/kg, which is 60% higher than that of the all-vanadium battery. The preliminary exploration shows that the Mn2+/Mn3+ couple is electrochemically promising for redox flow battery.
Keywords: Redox Flow Battery (RFB); Mn2+/Mn3+ couple; V2+/V3+ couple
Investigation on electrolytes in vanadium halide redox flow battery for energy storage
Tao Hong
School of Electronic and Information Engineering,
Beihang University, Beijing, China Fangqin Xue * Department of Physical Chemistry, University of Science and Technology Beijing, Beijing, China Abstract: To optimize the anode electrolyte in vanadium halide redox flow battery, the viscosity, electrochemical impedance, cyclic voltammograms and steady polarization curve analysis have been studied. When the range of from 1.0 M to 1.5 M, the viscosity is small and the results of cyclic voltammograms, Electrochemical impedance spectroscopy and steady polarization curve show good reversibility of electrolyte. The sodium bromide concentration range from 1 M to 1.5 M is the suitable concentration range of sodium bromide.. Key words: vanadium halide, redox flow battery, anode

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