钒电解液的绿色制备及其热力学分析

Preparation,Thermodynamic and Electrochemical Properties of Vanadium Solution

以分析纯V2O5为原料,利用双氧水还原的方法制备钒电解液,并对五氧化二钒的溶解机理进行了研究.通过UV-Vis光谱分析和ICP,对钒电解液在电解过程中钒离子的价态变化和浓度变化进行表征.通过计算,得到了钒电解液制备的反应焓变和吉布斯自由能变化,结果表明:生成硫酸氧钒的反应为放热反应,并且该反应促进了五价钒离子的溶解.将所制备的电解液组装成动态电池,在电流密度为2.4 mA/cm2时,电池的电流效率、电压效率、能量效率分别为93.6%、98.1%和91.9%,充放电结果表明:所制备的电解液具有很好的活性,可以应用于钒电池.

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 con- centration change of vanadium solution were characterized by UV-Vis and ICP measurement in the following elec- trolysis procedure. AH and AG 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 re- sults 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.