Performance Analysis and Monitoring of Vanadium Redox Flow Battery via Polarization curves

Abstract

This article proposes the demonstration and deployment of a hand-tailored vanadium redox flow battery test station to investigate the effect of applied voltages on charging performance for electrolyte preparation and the effect of reactant flow rates on the balance of system capacity. Herein, the two different specifications of membranes and a number of electrode layers playing pivotal roles in the discharging characteristics of the VRFB were observed as well. Results indicated that 1.70 V of the charging voltage was suitable, when optimized voltage was considered from charging time, current, and the mole of electrons. The optimized flow rate (10 mL/min) must be controlled since it corresponds to mass transfer and electrolyte diffusion, resulting in reaction ability on electrode surfaces. The number of layers influenced active areas and the diffusion of electrolytes. Nafion 212 provided superior performance to Nafion 117, because it possessed lower ohmic resistance and allowed for easier proton transfer.