INTEGRATED COMPOSITE BIPOLAR PLATE-ELECTRODE DESIGN TO REDUCE CONTACT RESISTANCE IN VANADIUM REDOX FLOW BATTERIES

Abstract

Vanadium redox flow batteries (VRFBs) are assembled by stacking various components, which results in increase cell resistance. Herein, we propose bipolar plate-electrode integrated design to reduce contact resistance in VRFBs. By selectively impregnating a part of carbon felt with vinyl ester resin, the integrated structure was fabricated. Integrated structures consist of a hard layer and a soft layer, which act as a bipolar plate and an electrode, respectively. The integrated structure had 15% lower electrical resistance than conventional cell of VRFBs, which contribute to reduce ohmic overpotential in a polarization curve. Under a current density of 100 mA·cm-2, the energy efficiency of the integrated structure was 83.4%, which was 5% higher than that of conventional cell.