Abstract:

The mass transfer process of VO²⁺ in Nafion117 was studied, this work focused on the synergistic effect of concentration field and electric field in different operating conditions. Influence of electric field on the mass transfer process across membrane of VO²⁺ is oberserved, and the apparent electric mobility of VO²⁺ in Nafion117 was estimated based on experimental data. The results show that, the force of electric field on the VO²⁺ mass transfer process across membrane in high concentration condition is more obvious than that in low concentration condition. Increasing temperature as well as electrolyte convection can strengthen electric field effect on membrane crossing process of VO²⁺. The mass transfer process in membrane of VO²⁺ is accelerated by increasing additional positive electric field force, and the electric factor increases with time. Negative electric field can help alleviate the phenomenon of mass transfer process across membrane of VO²⁺.

Key words: vanadium flow battery, diffusion, solution, transport processes, electrolytes, membrane permeation

摘要：

研究了VO²⁺在Nafion117质子交换膜中的传质过程, 重点考察了不同操作工况下浓度场和电场的协同作用。定量了电场对钒离子透膜传质过程的影响大小, 并根据实验数据拟合出了VO²⁺在Nafion117膜中的表观电迁移率。结果表明:电场对高浓度电解液的离子透膜过程影响较大, 升高温度和增加电解液对流均强化了电场作用在钒离子透膜传质的影响, 加入的正向电场越强, 跨膜渗透越剧烈, 且电场因子随着时间的增加而增加。反向电场有利于缓解钒离子透膜传递过程。

关键词: 全钒液流电池, 扩散, 溶液, 传递过程, 电解质, 膜渗透