Performance influence of hydroxyl radical on graphite felt electrode used in all vanadium redox flow battery

Decomposition products from H2SO4 and H2O2,hydroxyl radical,was used for the surface treatment of the graphite felt electrode.Cyclic voltammetry and AC impedance measurements showed that the treated graphite felt cathode and anode peak current increased by 160.96% and 120.24% respectively,the polarization reaction resistance from 74.95Ω·cm2,was significantly reduced to 18.92Ω·cm2.The infrared spectra indicated that the treated surface contains a large number of oxygen-containing hydrophilic groups,and the Raman spectroscopy results show that the graphitization degree lower.This is further evidence of the graphite felt electrode surface by varying degrees of oxidation.XPS tests show that the oxygen content has an increase of 0.58%,quantitative proof of the infrared and Raman spectra of the test results.The static single-cell test results show that the treatment of charge-discharge capacity increased by 37.04% and 22.22% respectively.These analyzes confirmed that this method can significantly improve the vanadium redox flow battery performance.