Influence of eco-friendly agar-derivatives on the electrochemical performance of carbon felts electrodes of vanadium redox flow battery

• Published in: Journal of energy storage Vol. 84; p. 110599
• Main Authors: Fetyan, Abdulmonem, Alhammadi, Ayoob, Matouk, Zineb, Andisetiawan, Anugrah, Bahaa, Ahmed
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.04.2024
• Subjects: Agar; Bio-derived polymer; Carbon felt; Electrode; Redox flow batteries; Agar; Redox flow batteries; Electrode; Bio-derived polymer; Carbon felt
• ISSN: 2352-152X; 2352-1538
• DOI: 10.1016/j.est.2024.110599

In this study, bio-derived natural agar powder was used as an electrocatalyst for application as an electrode in all‑vanadium redox flow batteries. Different concentrations of agar solution were tested, and cyclic voltammetry studies confirmed that agar loaded felts have good catalytic activity toward both redox couples V4+/V5+ at the positive and V2+/V3+ at the negative side. Energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy demonstrated the presence of higher amount of oxygen-functional groups on the surface of the fibers. Contact angle measurements demonstrated an enormous increase in hydrophilicity of the felts treated with agar. Long-term charge/discharge profiles revealed 6 % higher energy efficiency and 13 % better discharge capacity retention for agar modified felts when compared to thermally treated carbon felts at a relatively high current density of 150 mA cm−2. •Enormous increase in hydrophilicity of carbon felt is achieved.•High energy efficiency and discharge capacity are reported at high current density.•Stable enhancement in VRFB performance is evident.•Lower charge transfer resistance is reported.