Role of convection and related effects on species crossover and capacity loss in vanadium redox flow batteries

► The role of convection on capacity loss of VRFBs is investigated. ► Convective transport is found to be the major mechanism for vanadium crossover. ► Viscosity of the electrolytes affects the direction/magnitude of the crossover. ► Crossover can be reduced by operating the system at constant pressure condition. ► Constant pressure can be achieved using asymmetric flow rates in half-cells.