The impact of pH on the fade rate has been reported before. 17 However, hydroxide concentrations higher than 1.0 M have rarely been examined. Figure shows the time-dependence of the discharge capacity of a cell that contains 0.1 M DHAQ in the negolyte and 0.06M/0.03 M ferrocyanide/ferricyanide in the posolyte in 1.0 M OH -. Similar tests were performed at various OH -concentrations and the fade rates are shown on Figure (for the definition of fade rate refer to the SI). Increasing the OH - concentration over the range 0.1-2.0 M reduces the fade rate from ∼100%/day to only ∼0.4%/day in 2.0 M OH -. Interestingly, the fade rate in 2.0 M OH -is very close to the fade rate of 0.38%/day previously reported in 1.0 M OH -when the electrochemical regeneration technique was implemented. Clearly, raising the concentration of OH -beyond 1.0 M can noticeably reduce the fade rate. Cycling was performed under constant current density at 50 mA/cm 2 followed by a potentiostatic hold. Cutoff voltages for the charge and discharge steps were 1.4 and 0.9 V, respectively. Cutoff current densities for the charge and discharge steps were 2 and 1 mA/cm 2 , respectively.