Exploiting through-plate reference hydrogen electrode to study cross-contamination and performance in Vanadium Redox Flow Battery

In this work a system of reference hydrogen electrode is applied at the inlet and outlet of both sides of a Vanadium Redox Flow Battery to measure how performance varies with different component such as membranes of different thickness and equivalent weight and electrodes of different morphology. The reference electrode set-up permits to distinguish between losses affecting the two electrodes at local level and is also able to monitor electrolytes potentials. The trends of open circuit potentials measured by the reference electrodes during cycling are associated to variation of the state of charge of the electrolyte solutions, which allows to evaluate the self-discharge of the battery and the imbalance of the electrolyte solutions. Furthermore, losses at positive and negative electrode are analysed from the measured overpotentials and associated with the characteristics of the electrodes.