A previous report on the analysis of supercapacitor data suggested a different equation for the analysis of non-ideal devices (SI Section 3) . However, we do not believe that this method is correct as it gives a capacitance value of 0.385 F for File 2, significantly higher than the other methods discussed above. We discourage the use of this equation in the future. As shown in Figure , most of the reported specific capacitance values for both File 1 and File 2 could be split into two distinct groups. In both cases, 54 -57% of values fall into the lower group, and 36 -37% of values fall in the upper group, with the values in the upper group being approximately four times larger than those in the lower group. Please note that most participating groups reported values in the same group for Files 1 and 2 apart from 2 groups. There is a greater spread in the reported specific capacitance values in both the upper and lower groups for the non-ideal dataset File 2, reflecting the larger variation in the reported total capacitance discussed above.