全钒液流电池电堆的均一性

Research on uniformity of vanadium redox-flow battery

全钒液流电池电堆的均一性直接影响到其寿命。本文从流道结构、运行参数等方面,系统探讨了影响全钒液流电池电堆均一性的各种因素。通过优化管路结构和液流框结构,提高了电堆的均一性,随支管管径不断减小,当主管与支管管径由4∶3减小到4∶1时,电堆进液流量标准偏差由0.039m/s降到0.001m/s,电堆进液流速均一性得到改善;通过优化液流框结构,使电堆单体电池电解液流量标准偏差由0.142m/s降到0.032m/s,改善了电堆单体电池均一性。电解液流量、充放电电流密度等运行参数影响全钒液流电池电堆均一性,对其进行了实验与分析,结果表明:电堆电压标准偏差随充放电电流增大而线性增大,其斜率与截距均与电解液性质、电极材料性质及表面结构等因素有关;电堆电压标准偏差随电解液流速的增大而减小,且在超过一定流量后不再变化,为全钒液流电池材料选型优化、结构优化及运行提供技术支撑。

The uniformity of the vanadium redox flow battery（VRB）directly affect its life span. The flow channel structure and the operating parameters of the battery had been measured and analyzed. By optimizing the pipeline structure and flow frame structure,the uniformity of the stack was improved. When the ratio of executive diameter to branch pipe diameter was reduced from 4∶3 to 4∶1,the standard deviation of the liquid flow velocity was reduced from the 0.039m/s to 0.001m/s. The standard deviation of the stack liquid flow had been decreased from the 0.142m/s to 0.032m/s by optimizing the flow frame structure. The standard deviation of VRB increased linearly with the increase of the current. The slope and intercept of the linear equation related to the properties of electrolyte,electrode materia,and surface structure. The standard deviation of VRB decreased with the increase of the flow rate, but stayed the same after a certain flow was reached. The experimental results can provide technical support for the material selection and the operation of VRB.