Optimization of thermal treatment of carbon felt electrode based on the mechanical properties for high-efficiency vanadium redox flow batteries

• Published in: Composite structures 2022-06, Vol.290, p.115546, Article 115546
• Main Authors: Kaur, Amanpreet, Il Jeong, Kwang, Su Kim, Seong, Woo Lim, Jun
• Format: Article
• Language: English
• Subjects: Carbon felt; Electrode; Heat treatment; Mechanical properties; Oxygen functionalities; Vanadium redox flow battery
• ISSN: 0263-8223; 1879-1085
• DOI: 10.1016/j.compstruct.2022.115546

•Thermal oxidation treatment and temperature have been optimized with sustainable mechanical properties.•The carbon felt treated at 600 °C-30 min has superior properties among other specimens.•XPS analysis reveals the 8% increase in the oxygen content as a result of thermal oxidation.•EIS analysis reveals that the heat treatment increases the reactive velocity towards the redox couple.•The thermal oxidation increased the cell performance of the VRFB. Thermal oxidation is the easiest and most common way to generate oxygen functional groups on the surface of carbon felt, which improves the performance of vanadium redox flow batteries (VRFBs). Many researchers have reported the study of the various parameters for thermal oxidation. However, the aspect of reduction in the mechanical properties of the electrode has not yet been reported. In this study, optimized oxidation time and temperature were selected based on compression test analysis. The selection of optimized treatment temperature and time duration is based on the oxygen content and specific surface area. A carbon felt electrode oxidized at 600 °C for 30 min showed the best performance among the other treated electrodes. This study is mandatory at the laboratory scale and commercial levels, where the stability of the electrode for an extended period plays a significant role. Moreover, optimized pretreatment is essential for various other studies.