DEVELOPMENT OF HIGH-PERFORMANCE BIPOLAR PLATES BY ELECTRODE INTEGRATION FOR VANADIUM REDOX FLOW BATTERIES

The bipolar plate is a crucial element of the vanadium redox flow battery (VRFB) as it serves as both the electrical path for the electrolyte and the structural support for the cell within the VRFB stack. The graphite material has been used as the bipolar plate, mostly due to its excellent electrical conductivity. A significant limitation of the VRFB is the presence of several core components. Hence, the internal contact resistance (ICR) arises between the electrode and bipolar plate within the cell stack, and it is significantly greater than the bulk resistance of the corresponding specimens. This study focuses on creating an integrated assembly of the electrode and bipolar plate to address the limitations of the ICR. The integrated assembly was constructed using a single carbon felt specimen. The study resulted in the development of an electrode-integrated BP that exhibited a 28% decrease in overall resistance and a 175% improvement in mechanical properties. Gas permeability and acid aging tests confirmed that the electrode-integrated BP exhibited zero gas permeability and was therefore durable. In conclusion, a two-cell charge/discharge test confirmed that the energy efficiency of the integrated structure had increased by 6.3%. The proposed integrated structure is thus a potentially advantageous substitute for conventional BP and CF electrode assemblies.