全钒液流电池多孔电极非均匀压缩的数值模拟  

Numerical simulation for non-uniform compression of porous electrodes in vanadium flow batteries

作　　者：王庆泰 张赛[1] 王杰敏 WANG Qingtai;ZHANG Sai;WANG Jiemin(Faculty of Mechanical and Electrical Engineering,Kunming University of Science and Technology,Kunming 650500,Yunnan,China)

机构地区：[1]昆明理工大学机电工程学院,云南昆明650500

出　　处：《化工进展》2024年第6期2940-2949,共10页Chemical Industry and Engineering Progress

基　　金：云南省科技厅青年基金(KKSQ201701008)。

摘　　要：电极压缩会导致全钒液流电池的多孔电极侵入流道影响电池性能。本文建立了蛇形流道多孔电极非均匀压缩的三维稳态模型,对比研究了多孔电极非均匀压缩和多孔电极矩形压缩的内部压降、电解质流速和过电位分布的不同,发现多孔电极非均匀压缩与实际情况符合程度高。分析了不同压缩比对电极非均匀压缩多孔电极内部压降、电解质速度、反应物质浓度分布、电解质电位、过电位、局部电流密度和浓差过电位的影响。结果表明:在压缩比增大的情况下,电极非均匀压缩多孔电极内部压降和速度增大程度高于电极矩形压缩,电极非均匀压缩侵入部分与流道接触区域处过电位高于电极矩形压缩。电极非均匀压缩多孔电极内部反应物质浓度分布均匀性增大,电解质电位和过电位降低,阴极区域局部电流密度和浓差过电位上升。Electrode compression can cause the porous electrodes of all vanadium flow batteries to invade the flow channel,affecting battery performance.This article established a three-dimensional steady-state model for non-uniform compression of porous electrodes in a serpentine flow channel,and compared the differences in internal pressure drop,electrolyte flow rate,and overpotential distribution between non-uniform compression of porous electrodes and rectangular compression of porous electrodes.It was found that non-uniform compression of porous electrodes was highly consistent with the actual situation.The effects of different compression ratios on the internal voltage drop,electrolyte velocity,concentration distribution of reactants,electrolyte potential,overpotential,local current density and concentration overpotential of non-uniform compression porous electrode were analyzed.The results showed that with an increase in compression ratio,the increase in internal pressure drop and velocity of the non-uniformly compressed porous electrode was greater than that of the electrode rectangular compression.The overvoltage at the contact area between the electrode non-uniformly compressed invasion part and the flow channel was higher than that of the electrode rectangular compression.The uniformity of the concentration distribution of reactants in the porous electrode with non-uniform compression increased,the electrolyte potential and overvoltage decreased,and the local current density and concentration overvoltage in the cathode area increased.

关 键 词：全钒液流电池 电解液 多孔电极非均匀压缩模型 数值模拟 

分 类 号：TM911[电气工程—电力电子与电力传动]