Redox flow batteries have seen interest in electronic applications because of their potential to simultaneously deliver electric power and remove heat. For these applications, the flow battery has to be constructed on a side of a computer chip, with components such as flow channels, manifolds, supply tubes, electrodes, membranes and current collectors. Since experimentation with micro-scale components is especially expensive and time-consuming, there is a need to develop computational tools to understand trade-offs in the design and operation of these flow batteries. Computational fluid dynamics study of redox flow batteries is carried out using commercial software package COMSOL Multiphysics. This paper analyses the effect of flow rate and electrode thickness on current and voltage distribution in the flow battery. Tradeoff between flow rate and pressure drop also has been analyzed. We have quantified the effects of flow rate on pressure drop and thereby the parasitic pumping power and the effect of electrode thickness on the ohmic overpotential and thereby the performance of the cell.