Optimal electrolyte flow distribution in hydrodynamic circuit of vanadium redox flow battery

• We present results of studies of electrolyte flow in vanadium redox flow battery.
• We found a dependence of the electrolyte flow rate on electric current.
• We found a distribution of electrolyte flow in a half-cell of the battery.
• We constructed test battery with nearly uniform electrolyte flow distribution in each cell.

This article presents the results of studies of the electrolyte flow configuration in a vanadium redox flow battery (VRFB). The flow structure is formed by a system of inlet and outlet channels and of porous collectors of the battery. This configuration is considered as a hydrodynamic circuit. The theoretical models, which were used to simulate the flow behaviour, are based on conservation laws of mass and of electric charge. The electrolyte flow was analysed on the basis of three theoretical models: total flow, depending on the electric current; flow distribution in the inlet/outlet channel system; flow distribution in a half-cell. For the test battery a capacity availability was calculated and measured in a wide range of the flow rate and of the electric current. The flow distribution in the porous collector was calculated and the efficiency by the different flow configurations in the half-cells was measured. The parameters and the configuration of the electrolyte inlet/outlet channels were optimized to obtain the uniform distribution of the electrolyte flow to each half-cell.