A comprehensive parametric study on thermal aspects of vanadium redox flow batteries

Vanadium redox flow batteries are recognized as well-developed flow batteries. The flow rate and current density of the electrolyte are important control mechanisms in the operation of this type of battery, which affect its energy power. The thermal behavior and performance of this battery during charging and discharging modes are also important. As a consequence, the aim of this investigation is to deeply study the impact of different working parameters on the temperature distribution and state of charge of these batteries. To achieve these goals, a single battery thermal model is established. The effects of various operating parameters, including working temperature, molar concentration, flow rate, and current density of the electrolyte, on the thermal behavior, state of charge, and performance of this type of battery are investigated. It is observed that the temperature distribution of high flow rate (90 mL min-1) is more uniform than that of other flow rates (30 and 60 mL min-1). In the end of the discharging mode, the battery voltage performance increases with the increase in the electrolyte flow rate. The temperature distribution of high current density (80 mA cm-2) is relatively uneven, and the local heating is produced at the battery outlet. The end time in the charging and discharging modes for the case of the high current density (80 mA cm-2) is faster than other current densities (20 and 40 mA cm-2).