Vanadium Species in CH₃SO₃H and H₂SO₄ Mixed Acid as the Supporting Electrolyte for Vanadium Redox Flow Battery

摘要

Cyclic voltammetry (CV) and electrochemical impedance spectroscopies (EIS) of 2M V(IV)electrolyte in CH3SO3H and H2SO4 mixed acid solution (MAS sample) and in H2SO4 (Pristine sample)as the positive electrolyte in vanadium redox flow battery (VRFB) were investigated. CV resultsrevealed that the MAS sample had a higher reversible redox reaction than Prisinte sample. EIS showedthat. The performance of a VRFB with MAS sample as positive electrolyte was investigated with the2 charge-discharge technique. At 120 mA/cm , VRFB with MAS sample exhibited the higher energydensity (39.87 Wh/L) in comparison of Pristine sample. Cycling tests indicated that VRFB with themixed acid system possessed a stable cycling performance during 30 cycles.