【作者】 王琼； 屈治国；

【Author】 Wang Qiong;Qu Zhiguo;MOE Key Laboratory of Thermo-Fluid Science and Engineering,Xi’an Jiaotong University;

【机构】 西安交通大学热流科学与工程教育部重点实验室；

【摘要】 电池电势和过电压大小与多孔电极内部电解液浓度分布情况紧密相关,电解液浓度分布情况又受电化学反应和多孔电极材料的影响。为模拟研究钒液流电池多孔电极内电解液传输特性,本文通过建立单体全钒氧化还原液流电池的二维稳态数学模型,揭示了电流密度、电极孔隙率和电解液流速对电解液和电极电势分布、过电压分布、反应物浓度分布的影响。模拟结果显示电势分布主要受电解液中离子浓度分布及电解液、电极材料电导率的影响,过电压随着电流密度增大而增大,同时导致电极极化增大、副反应加剧,降低电池使用效率。降低电极孔隙率或提高电解液流速能使反应物浓度分布更加均匀。研究结果可为优化全钒氧化还原液流电池性能提供指导。更多还原

【Abstract】 The potential and over-potential of the cell depends on concentration distribution of electrolyte in the porous electrode which is also affected by the electrochemical reaction coupled with porous electrode materials. A two-dimensional stationary model is proposed and applied to describe electrolyte transport properties in the porous electrode of a single all-vanadium redox flow cell. Emphasis is placed on studying the effects of applied current density, electrode porosity and flow rate of electrolyte on the cell performance. The distributions of electrolyte and electrode potential, over-potential and electrolyte concentration are numerically tested. The model results indicate that the potential is mainly affected by the reactant concentration distribution and the conductivity of the electrolyte and electrode materials, the over-potential increase with the applied current density, the electrode polarization and side reactions increase simultaneously and the efficiency of the battery will be severely affected. Lower electrode porosity or higher electrolyte flow rate will lead to a more uniform distribution of the reactant concentration.更多还原