Performance of a low cost interdigitated flow design on a 1 kW class all vanadium mixed acid redox flow battery

•3-cell 1 kW class all vanadium mixed acid RFBs were made with three flow designs.•The stack cell with a novel interdigitated design exhibits smaller pressure drops.•The second interdigitated design (IDD2) would give the stack designer flexibility.•The stack performance is related to surface areas of electrodes at low flow rates.•The stack cell with IDD2 shows highest energy efficiencies.

Three flow designs were operated in a 3-cell 1 kW class all vanadium mixed acid redox flow battery. The influence of electrode surface area and flow rate on the coulombic, voltage, and energy efficiency and the pressure drop in the flow circuit will be discussed and correlated to the flow design. Material cost associated with each flow design will also be discussed.