Study on thermal oxidation modification of carbon felt electrode based on flow battery

Abstract Thermal oxidation of the carbon felt electrode for vanadium redox flow batteries (VRFBs) modifies it. The investigation focuses on how the structure and functionality of the electrode are affected by the length of thermal oxidation. The improved electrode’s make-up, structure, and electrochemical properties are analyzed using techniques such as X-ray diffraction, scanning electron microscopy, contact angle measurements, specific surface area analysis, cyclic voltammetry, and electrochemical impedance spectroscopy. The results show that with the extension of oxidation time, the specific surface area of the original carbon felt is 0.187 m 2 /g, and the specific surface areas of the samples treated at 500°C for 6 hours and 9 hours are 4.353 m 2 /g and 5.746 m 2 /g respectively. The contact angle of the original carbon felt is 143.034°, the sample treated at 500°C-6 hours is completely wetted, and the closed area of the CV curve measured by cyclic voltammetry is the largest.