High energy efficiency with low-pressure drop configuration for an all-vanadium redox flow battery

In this paper, we present experimental studies of electrochemical performance of an allvanadium redox flow battery cell employing an active area of 103 cm2, activated carbon felt, and a novel flow field, which ensures good electrolyte circulation at low pressure drops. Extended testing over 151 consecutive charge/discharge cycles has shown steady performance with an energy efficiency of 84% and capacity fade of only 0.26% per cycle. Peak power density of 193 mW cm2 has been obtained at an electrolyte circulation rate of 114 ml min1, which corresponds to stoichiometric factor of 4.6. The present configuration of the cell shows 20% improved in peak power and 30% reduction in pressure drop when compared to a similar cell with a different electrode and a serpentine flow field.