Differential Electrochemical Mass Spectrometry of Carbon Felt Electrodes for Vanadium Redox Flow Batteries

We successfully conducted electrochemical and online mass spectrometric measurements on commercial carbon felt electrodes with a differential electrochemical spectrometry setup. Its capability is demonstrated by simultaneous mass spectrometric and electrochemical measurements. Half-cell tests, such as cyclic voltammetry, and coulometry of the redox couples can be performed under stopped flow of the electrolyte. We use different potential windows, and two types of electrolytes while monitoring potential dependent H2, O2 and CO2 formation. At oxidizing potentials, we did not observe oxygen evolution, only carbon corrosion. An increase in CO2 and H2 formation at high and low potentials in the presence of vanadium is observed.