An electrolyte with high thermal stability for the vanadium redox flow battery

Abstract

Vanadium Redox flow Battery (VRB) cannot be used in the widespread environment because the problem of generating V2O5 precipitation has restricted to its industrialization. To overcome this problem, this paper describes the thermally stable vanadium positive electrolyte using sodium oxalate as a supporting material for the VRB. To show the effectiveness of the proposed solution, thermal stability experiment at 60 degrees C, viscosity measurement and electrochemical analysis (i.e., cyclic voltammetry, charge-discharge test, and scanning electron microscopy) were carried out, respectively. The experimental results indicate that the new electrolyte improves the charging and discharging capacity by about more than 18% for 30 cycles when compared with the pristine electrolyte, and can provide a higher thermal stability for the long-time operation of the VRB. Consequently, sodium oxalate is shown to provide an electrolyte-additive solution for high-temperature operations of the VRB.