Electrical Characterization of Vanadium Flow Battery-Cell Test Facility (VFB-CTF): Early Results and Methods for Scaling Up

Technological enhancement plays a fundamental role in view of the proper design of industrial Flow Battery (FB) systems, which are recognized as one of the most promising solutions for stationary energy storage applications. This work presents the design, construction and early operation of a single-cell medium-size Vanadium Flow Battery (VFB) Cell Test Facility, dubbed VFB-CTF suitable to test materials and geometries in easily controllable and adjustable conditions. VFB-CTF is also capable of testing small VFB stacks. The test bench has been designed and built to accurately measure the main thermal, hydraulic, electric, and energetic quantities affecting the performance of VFBs. By extrapolating such measurements, the performance of large-scale RFB stacks can be estimated by means of analytical formulations built on similitude concepts. In this work, early experimental results i.e. polarization curves and Nyquist plots from Electrochemical Impedance Spectroscopy measurements of some of the most promising active materials for these applications, obtained from the world’s leading manufacturers, will be reported and discussed. Measurements provided by VFB-CTF can effectively be used to address criteria and metrics for the design of industrial-scale RFBs.