Preparation, Thermodynamic and Electrochemical Properties of Vanadium Solution

The vanadium solution was prepared by the mixture of hydrogen peroxide and vanadium pentoxide in sulphuric acid solution. The solubility mechanism of vanadium pentoxide was investigated. The valence and concentration change of vanadium solution were characterized by UV―Vis and ICP measurement in the following electrolysis procedure. ÷H and ÷G of the reaction were calculated. The results showed that the reaction was exothermic. The electrochemical activity was characterized by the charging and discharging experiment. And the results showed that the high current efficiency, voltage efficiency and energy efficiency of 93.6%, 98.1% and 91.9% were obtained at the current density of 2.4 mA/cm2, respectively. This indicated that the prepared vanadium solution was suitable for vanadium redox―flow battery.