Characterization of Carbon Materials for Redox Flow Battery Electrodes By Potential-Step Coulometry

Redox-flow batteries, which are using organic compounds, aqueous solution, and new Ti/Mn redox systems, have been actively investigated [1,2,3]. Non-metal redox-flow batteries are strongly expected by the increasing in needs for low-cost, safe, and trusted energy storage applications. Both of redox active materials and cell systems of redox-flow batteries have made rapid and great progress in recent years. Redox-flow batteries are investigated frequently, and are now in a transition stage. We evaluated the electrode performance of three different kind of carbon electrode materials with vanadium electrolyte solution by using potential-step coulometry measurement. Different kind of electrolyte solutions were also evaluated with similar system. Figure 1 showed model of the half cell. In this experiment, electrolyte solution was stopped and charging and discharging current and coulomb number were measured. Figure 2 showed results of the voltage-step coulometry for two typical carbon electrodes (set voltages are 1.50 V for charging and 0.80 V for discharging). Electrochemical property of cathode and anode electrodes are also investigated individually. References: [1] B. Huskinson, M. P. Marshak, C. Suh, S. Er, M. R. Gerhardt, C. J. Galvin, X. Chen, A. Aspuru-Guzik, R. G. Gordon and M. J. Aziz, Nature , 505 , 195 (2014). [2] Y. -R. Dong, H. Kaku, K. Hanafusa, K. Moriuchi, and T. Shigematsu, ECS Trans ., 69 (18), 59 (2015) [3] S.-E. Chun, B. Evanko, X. Wang, D. Vonlanthen, X. Ji, G. D. Stucky and S. W. Boettcher, Nature Communications 6 , 7818 (2015). Figure 1