Effect of different dicarboxylic acid additives on electrochemical behavior of Vanadium Redox Flow Batteries

The vanadium redox flow battery (VRB) is one of the most promising electrochemical energy storage systems deemed suitable for a wide range of renewable energy applications that areemerging rapidly to reduce the carbon footprint of electricity generation. Typically, each cell comprises of an anode, a cathode and an ion exchange membrane separator that allows diffusion of ions across the membrane while preventing the cross-mixing of the electrolyte solutions fromthese two reservoirs. Redox flow batteries have many technical benefits over other energy storage systems; they represent an excellent combination of energy efficiency, capital cost andlife cycle costs when compared to other technologies. In this work some of short chain dicarboxylic acids were added to catholyte of VRFB to improvethe electrochemical behavior of V(V)/V(IV) redox couples. These additives were Oxalic acidand succinic acid. Cylic Voltammetry, Electrochemical Impedance Spectroscopy techniques were used to investigate the effect of these additives. According to the results of experiments Oxalic acid and succinic acid had better performance in comparison with the blank electrolyte, respectively.