 Anthraquinone-2, 6-disulfonic acid (AQDS) was added to the electrolyte of a vanadium redox flow battery (VRFB) with the goal of enhancing its performance. This study utilized carbon paper electrodes and a Nafion 117 ion exchange membrane for the membrane-electrode assembly. The cycling performance was investigated over multiple charge and discharge cycles. The addition of AQDS was found to increase capacity efficiency by an average of 7.6% over the control VRFB containing no AQDS, while decreasing the overall cycle duration by ~18%. It is thus reported that the addition of AQDS to a VRFB electrolyte has the potential to inexpensively increase the activity and capacity.