• • Exf-Gr/ACP electrodes achieved a 2.9-fold reduction in charge transfer resistance compared to pristine ACP, directly enhancing electrochemical kinetics and enabling higher power density in VRFB stacks.
• • Single-cell tests demonstrated a 2.5-fold increase in discharge capacity with Exf-Gr/ACP, indicating superior active material utilization and energy efficiency, critical for grid-scale storage economics.
• • Spray coating of Exf-Gr onto ACP provides excellent dispersion and high surface area, ensuring uniform catalytic sites and minimizing mass transport limitations, which is essential for scale-up to industrial electrode manufacturing.
• • The systematic comparison of CB, CNTs, and Exf-Gr establishes clear structure-performance relationships, guiding material selection for cost-effective VRFB electrode modification.