Performance of a vanadium redox flow battery with and without flow fields

• Published in: Electrochimica acta Vol. 142; pp. 61 - 67
• Main Authors: Xu, Q., Zhao, T.S., Zhang, C.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2014
• Subjects: Electrode thickness; Flow battery; Flow fields; System efficiency; Vanadium redox flow battery (VRFB); Vanadium redox flow battery (VRFB); System efficiency; Flow fields; Electrode thickness; Flow battery
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2014.07.059

•The performances of a VRFB with/without flow fields are compared.•The respective maximum power efficiency occurs at different flow rates.•The battery with flow fields Exhibits 5% higher energy efficiency. A flow field is an indispensable component for fuel cells to macroscopically distribute reactants onto electrodes. However, it is still unknown whether flow fields are also required in all-vanadium redox flow batteries (VRFBs). In this work, the performance of a VRFB with flow fields is analyzed and compared with the performance of a VRFB without flow fields. It is demonstrated that the battery with flow fields has a higher discharge voltage at higher flow rates, but exhibits a larger pressure drop. The maximum power-based efficiency occurs at different flow rates for the both batteries with and without flow fields. It is found that the battery with flow fields Exhibits 5% higher energy efficiency than the battery without flow fields, when operating at the flow rates corresponding to each battery's maximum power-based efficiency. Therefore, the inclusion of flow fields in VRFBs can be an effective approach for improving system efficiency.