Abstract The energy storage system (ESS) is widely investigated because it can solve various energy-related problems without additional power plants. Among the ESSs, a vanadium redox flow battery (VRFB) is one of the most promising technologies due to its scalability without explosiveness. The bipolar plate is a multifunctional component that provides an electrical path and separates cells. A bipolar plate should simultaneously have low electrical resistance, high mechanical properties and chemical durability. In this study, a nano carbon/fluoroelastomer composite bipolar plate was developed to substitute for the conventional thick graphite bipolar plate. The ‘soft-layer method’ was adopted to expose the carbon fibers on the surface of the composite to increase its electrical conductivity. The solution casting method was applied to fabricate the high fiber volume fraction composite structure with a dispersion of carbon black. The performance of the carbon/fluoroelastomer composite bipolar plate was evaluated by testing the permeability, mechanical properties, and electrical properties. Finally, unit-cell charge/discharge tests were conducted to verify the performance of the composite bipolar plate.