Carbon nanofibers embedded in nanopores decorated graphite felt electrodes for enhanced vanadium redox flow batteries performance

This study introduces a novel electrode design, incorporating carbon nanofibers (CNFs) embedded in nanopores on graphite felt, achieved through a simplified one-step chemical vapor deposition process. The electrodes exhibit a uniform distribution of carbon nanofibers and nanopores, significantly enhancing active sites for vanadium redox reactions. Comprehensive characterization, including X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) surface area analysis, confirmed a significant increase in surface area and catalytic activity. When tested at a current density of 200 mA cm(-2), the modified electrodes demonstrated a notable improvement in electrochemical performance, achieving over 75 % energy efficiency and maintaining this efficiency over 300 cycles. The cyclic voltammograms (CV) and electrochemical impedance spectroscopy (EIS) results indicated enhanced kinetics and reduced charge transfer resistance. Post-mortem SEM images confirmed the structural integrity of the nanofibers after extensive cycling tests.