Although the calculated metrics were generally consistent from one cycle to the next (within ~10%), there were occasional outlier cycles. These are evident in the gas in reservoir vs time plots as deviations from a smooth, roughly sinusoidal curve. Such outliers are attributed to rapid changes in temperature (due to other activities in the lab) or intermittent leaks in the cell (caused by poor seals, perhaps from corrosion by electrolyte interaction with the metal of the cell). Any results from these cycles were excluded from the analysis above to calculate the reported data. -1 current density. Anomalous peaks presumed to be from short-term temperature changes. As opposed to cells A1 and A2, only the electrode not directly exposed to the gas was soaked with electrolyte (the gas-exposed electrode was wetted with a few drops of electrolyte). During the first part of the experiment, where the open circuit voltage was measured, initial pressure increases are observed as the cell thermalizes in the incubator oven. Subsequently, pressure decreases are observed due to chemical adsorption of CO 2 into the supercapacitor cell.