The inhomogeneous distribution of electrolyte over the porous electrode is one of the main issues hindering vanadium flow battery performance, limiting the system power density. Moreover, the interplay between fluid dynamics in distribution channels and morphology of porous electrodes is not well understood at local level throughout the cell active area, where local reactant starvation may occur and further limit system performance. Therefore, a systematic local characterization is fundamental to improve the understanding of system operation and to enhance system power density. This work discusses the implementation of a 10 regions macro-segmented flow battery with 25 cm² active area, that permits the local measurement of polarisation curves and impedance spectra. Both positive and negative symmetric cells, as well as all-vanadium configuration, are adopted, combining carbon paper electrodes of different thickness with single serpentine and interdigitated distributors. The characterization evidences that single serpentine presents poor performance towards cell outlet, while interdigitated geometry is limited in the central region of active area. In most of the investigated operating conditions, single serpentine induces a more heterogeneous operation, especially if coupled with thinner electrode and positive electrolyte. Moreover, the representativeness at local level of symmetric cells compared to all-vanadium one is analysed and discussed.

电解质在多孔电极上的不均匀分布是阻碍钒液流电池性能，限制系统功率密度的主要问题之一。此外，在整个电池活性区域的局部水平上，分配通道中的流体动力学与多孔电极的形态之间的相互作用还没有得到很好的理解，在该区域中可能发生局部反应物不足并且进一步限制了系统性能。因此，系统的局部表征对于增进对系统操作的理解并提高系统功率密度至关重要。这项工作讨论了25 cm ²的10个区域的宏分段液流电池的实现有源区域，可以对极化曲线和阻抗谱进行局部测量。正负对称电池，以及全钒配置，都采用了不同厚度的碳纸电极与单一的蛇形和指状分配器相结合。表征证明单一的蛇纹石对细胞出口表现出较差的性能，而交叉指的几何形状则局限于活动区域的中心区域。在大多数研究的运行条件下，单个蛇纹石引起的操作更加不均一，特别是如果与较薄的电极和正极电解液结合使用的话。此外，分析和讨论了对称电池与全钒电池相比在局部水平上的代表性。