基于框架设计的液流电池流场优化模拟研究

液流电池通常采用对角平推流流场，会形成电解液滞留区，造成电池局部浓差极化大，影响综合性能。鉴于此，提出了一种基于框架设计的流场优化方法，通过设计电极框架，可以得到“蛇形流道”和“平行流道”两类流场。以全钒液流电池为例，通过数学建模，研究了不同流场结构和参数对于多孔电极内电解液流动特性、电化学反应和温度变化特性的影响规律。计算结果与实验结果一致性良好，结果表明：电解液在“平行流场”内的流动均匀性比在“蛇形流场”内好，且不存在滞留区，同时在“平行流场”内浓差极化也较“蛇形流场”低；此外，对于同样的电极面积，在电极内部的“平行流道”越多，电解液的流速分布越均匀，反应特性越好。

Simulation study on flow field optimization of flow battery based on flow frame design

The flow battery usually adopts a diagonally pushing flow field, which will form an electrolyte retention zone, which causes a large concentration polarization of the battery, which affects the overall performance. In view of this, a flow field optimization method based on frame design is proposed. By designing the electrode frame, two kinds of flow fields,“serpentine flow path”and“parallel flow path”can be obtained. Taking vanadium redox flow battery as an example, the effects of different flow field structures and parameters on the flow characteristics, electrochemical reaction and temperature change characteristics in porous electrode were studied by mathematical modeling. The calculated results are in good agreement with the experimental results. The results show that the flow uniformity of the electrolyte in the“parallel flow field”is better than that in the“serpentine flow field”, and there is no stagnant zone, and in the“parallel flow field”the concentration polarization is also lower than the“serpentine flow field”; in addition, for the same electrode area, the more“parallel flow channels”inside the electrode, the more uniform the flow velocity distribution of the electrolyte, and the better the reaction characteristics.