Non-isothermal model for vanadium redox flow batteries

A non-thermal model for the dynamic working process of vanadium redox flow batteries (VRFB) is established based on the significant difference in the thermophysical properties among porous electrode, electrolyte and current collector with the vanadium crossover included. Compared with experimental results in literature, the maximum error of the simulation is 2.91%, verifying the correctness of the model. The model is applied to investigate the mass and heat transfer in the electrodes region and the current collectors region. Results indicate that vanadium concentration increases in positive half-cell and decreases in negative half-cell after several cycles, which reduces the battery capacity. Current density has significant impact on the heat generation and the temperature under condition of larger current density is higher when reaches thermal equilibrium with ambient. Moreover, the established model forms a solid foundation for the development of non-isothermal models for large-scale VRFBs energy storage system.