In the first part of the experiment, 2,6-DHAQ accumulates in the catholyte during the 12 h rest period with a crossover rate of (4.2 ± 0.3) 10 -4 mol m -2 h -1 , consistent with our previous work (Figure ). However, during the 1.5 V voltage hold step, the measured 2,6-DHAQ concentration in the catholyte starts to decrease, ultimately leading to a complete loss of 2,6-DHAQ 1 H NMR signal (Figure ). Interestingly, the loss in 2,6-DHAQ signal does not correspond with the start of the voltage hold. Instead, it occurs just before ferricyanide reaches its maximum concentration, as measured by the state-of-charge (Figure ). Once the battery was discharged and allowed to Notably though, the crossover rate of 2,6-DHAQ was lower at just (2.6 ± 0.1) 10 -4 mol m -2 h -1 .