[1B01-04] Elemental and Isotope Analysis

[1B01] Electrochemical analysis of decavanadate ions in VRFBs

*Yuki Yokoyama¹, Akihiro Uehara², Chizu Kato¹, Toshiyuki Fujii¹ (1. Osaka Univ., 2. QST)

Keywords:VRFB, decavanadate ions, cyclic voltammetry, raman spectrometry

Storage batteries play an important role in Japan's renewable energy policy. Among them, vanadium redox flow batteries (VRFBs) are focused as easily reusable batteries. However, VRFBs have low energy density and are inefficient for downsizing. Therefore, vanadate ions, which have high solubility, is considered. They produce polymerized species when their concentration increases. Among the species, decavanadate ions have been confirmed to have redox reactions between tetravalent and pentavalent. In this study, the redox behavior of decavanadate ions were analyzed using cyclic voltammetry and Raman spectrometry, and their use for VRFBs was considered. Decavanadate ions were stable in the weak acidic region and they were suggested to be reduced from pentavalent to tetravalent in two-steps.