Analysis of Battery Performance and Mass Transfer Behavior for Organic Redox Flow Battery with Different Flow Fields

The mass transfer performance is unclear to limit the development of organic flow battery, which is regarded as the emerging electrochemical energy storage technology. The mass transfer behaviors in the electrode are influenced by the flow fields, which is indispensable. A three-dimensional and steady numerical model of the organic flow battery is established and the results are verified by the experiments data. The battery performance and mass transfer behaviors are analyzed under different flow field for the charge/discharge processes based on this model. Compared with other flow fields, the interdigital flow field can achieve the best charge-discharge performance, which is mainly due to the improvement distribution uniformity of active species. The average concentration of the interdigital flow field is 45.1% higher that of the conventional flow field. The effects of the flow rates and initial concentration of electrolyte on the battery performance are investigated, and the results indicate that appropriate inlet flow rate can lead to the highest net discharge powers and power-based efficiency of the flow battery. Although the increasing of the initial concentration can improve the battery performance, the improvement is too slight when the concentration is high enough, which can lead to the waste of active species.