School of Mechanical and Manufacturing Engineering, UNSW, Sydney, NSW 2052, Australia.
Molecules. 2019 Oct 28;24(21):3877. doi: 10.3390/molecules24213877.
Redox flow batteries (RFBs), provide a safe and cost-effective means of storing energy at grid-scale, and will play an important role in the decarbonization of global electricity networks. Several approaches have been explored to improve their efficiency and power density, and recently, cell geometry modification has shown promise in efforts to address mass transport limitations which affect electrochemical and overall system performance. Flow-by electrode configurations have demonstrated significant power density improvements in laboratory testing, however, flow-through designs with conductive felt remain the standard at commercial scale. Concentration gradients exist within these cells, limiting their performance. A new concept of redistributing reactants within the flow frame is introduced in this paper. This research shows a 60% improvement in minimum V concentration within simulated vanadium redox flow battery (VRB/VRFB) cells through the application of static mixers. The enhanced reactant distribution showed a cell voltage improvement by reducing concentration overpotential, suggesting a pathway forward to increase limiting current density and cycle efficiencies in RFBs.
氧化还原液流电池（RFB）为电网级储能提供了安全且具成本效益的手段，将在全球电网脱碳过程中发挥重要作用。人们已经探索了几种方法来提高其效率和功率密度，最近，通过改变电池几何形状来解决影响电化学和整体系统性能的质量传输限制问题已初见成效。在实验室测试中，流经电极的配置已显示出显著的功率密度提高，然而，在商业规模上，具有导电毡的流通式设计仍是标准。这些电池中存在浓度梯度，限制了它们的性能。本文提出了在流框内重新分配反应物的新概念。通过应用静态混合器，本研究表明在模拟的钒氧化还原液流电池（VRB/VRFB）中，最小 V 浓度提高了 60%。增强的反应物分布通过降低浓度过电势提高了电池电压，这表明在提高 RFB 的极限电流密度和循环效率方面有了一条前进的道路。
