Carbon-polymer composite electrodes have been developed and investigated for application in the vanadium redox flow battery. Electrical, electrochemical, physical and mechanical properties as well as chemical resistance and solution permeability of a wide range of carbon-polymer composite materials were evaluated. Volume resistivities as low as 0.21 OMEGA cm were achieved with composites based on polypropylene, this being combined with excellent stability. Finally, the performance of a vanadium redox flow cell employing the best composite electrode was evaluated and voltage efficiencies as high as 91% were achieved at a charge/discharge current density of 20 mA cm-2.