High-Performance Vanadium Redox Flow Battery with Polyacrylic Acid-Bound Carbon Nanoparticles on Graphite Felts

Abstract Power density enhancement is crucial for cost reduction and increased commercial viability of vanadium redox flow batteries (VRFB). The low performance of commercially used porous graphite felt electrodes is the main limiting factor in increasing the power density of such devices. Herein, we introduce a novel approach to improve electrode activity and conductivity by loading a considerable amount of carbon black nanoparticles on the graphite fibers using polyacrylic acid as a primary mucoadhesive polymer. The prepared electrode structure showed prominent inter-fiber connections, as evidenced by scanning electron microscope images, which significantly reduced the ohmic resistance and improved electron transfer. Galvanostatic charge-discharge profiles showed 12-15% higher energy efficiencies at current densities ranging from 50 to 150 mA cm-2 compared to thermally treaded felts with no signs of degradation after fifty cycles, marking a promising advancement in VRFB technology.