Mass transport plays a crucial role in the performance of redox flow batteries (RFBs). Generally, the electrodes used in RFBs are assemblies of randomly oriented carbon fibers (e.g. graphite felts, carbon papers). It has been shown that ordered arrangements exhibit enhanced mass transport performance (e.g. carbon cloths). Our investigations are focused on evaluating the role of the electrode orientation alone, on the mass transport with electrodes oriented parallel and perpendicular to the electrolyte flow direction. The electrodes employed were prepared with embroidery, and composed of Cu wires 80 µm in diameter. The space between wires was maintained at 1.1 mm during construction to enable complete electrolyte accessibility through the electrode, and the cell structure was designed to ensure uniform electrolyte velocity across the whole electrode surface area. The limiting currents were measured for both electrode orientations with linear sweep voltammetry. The results showed 18 % greater mass transport coefficient for the perpendicular orientation as a consequence of greater accessibility of the reactants to the electrode surface. The findings provide insights for the optimization of electrode designs in mass-transport-limited reactors, such as RFBs.

大众运输在氧化还原液流电池（RFB）的性能中起着至关重要的作用。通常，RFB中使用的电极是随机取向的碳纤维（例如石墨毡，碳纸）的组件。已经显示，有序布置表现出增强的大众运输性能（例如，碳布）。我们的研究集中在评估电极定向的作用，在平行于或垂直于电解质流动方向定向的电极的传质方面。所用的电极是经过刺绣处理的，由直径为80 µm的铜线组成。在构造过程中，导线之间的间距保持在1.1毫米，以确保电解液可以完全通过电极进入，并设计了电池结构，以确保在整个电极表面积上保持均匀的电解液速度。用线性扫描伏安法测量两个电极方向的极限电流。结果表明，由于反应物更易于接近电极表面，因此垂直取向的传质系数提高了18％。这些发现为优化有限运输反应堆（例如RFB）中的电极设计提供了见识。