To achieve a low fade rate, the electrochemical regeneration technique was integrated into the cell cycling in 2.0 M OH -. Because the fade rate in 2.0 M OH -is reasonably low (∼0.4%/day), we hypothesized that, combined with the effect of regeneration, the fade rate should be lowered dramatically. As shown and annotated on Figure , however, the regeneration in 2.0 M OH -is noticeably less effective and unpredictable in contrast to the value of 90% previously reported for 1.0 M OH -16 . Interestingly, when the discharge cutoff voltage was raised to 0.95 V or higher, the recovery efficiency, defined as the fraction of the electroactive species lost since the previous regeneration step that is converted back into electroactive species during the regeneration step, became repeatable and remained at 88%. The effectiveness of the regeneration step thus appears to be very sensitive to the cycling discharge cutoff voltage. Test conditions: negolyte contained 6.5-7.0 ml of 0.05 M DHA, and the posolyte comprised 120 ml of 0.04 M potassium ferrocyanide and 0.02 M potassium ferricyanide. DHA oxidation conditions: constant current density at 2 mA/cm 2 followed by potentiostatic hold at 0.6 V until a cutoff current density of 0.75 mA/cm 2 was reached. Dimer oxidation conditions: constant current density at 2 mA/cm 2 followed by potentiostatic hold at -0.1 V until a cutoff current density of 0.75 mA/cm 2 was reached. Cycling of the formed DHAQ: constant current density of 50 mA/cm 2 followed by a potentiostatic hold. The cutoff voltage for the charge and discharge steps were 1.4 V and 1.0 V, respectively. Cutoff current densities for the charge and discharge steps were 2 mA/cm 2 .