Electrocatalytic Effects of (Zr, Ti, Mo)-Doped Niobium Pentoxide Nanocrystal Impregnated Carbon Felt for Vanadium Redox Flow Batteries

Abstract

The electrocatalytic effectiveness of titanium, molybdenum, and as zirconium dopants added to (10 w/o W)-Nb2O5 impregnated carbon felt is investigated as possible improvements to carbon felt electrodes for use in vanadium redox flow batteries. Because the presence of dopants affects both the electrical and morphological properties of the oxides, the electrochemical kinetics cannot be separated neatly from the surface area of the tested samples. To compare these compositions, the Electroactive Area parameter is introduced as a combination of electrode surface area and an overall kinetics function. Additional measurements are made to quantify the relative amounts of deposited mass, diffraction patterns of the oxide-impregnated carbon felt, electrical parameters of the equivalent circuit via EIS, and the total surface area by gas sorption analysis and BET theory.