These materials demonstrate similar capacitance values, with a range of only ~9 F/g (Fig. ), suggesting a minor impact of porosity on capacitance for these materials. Combining these results together with a wider series of nanoporous carbon samples including thermally annealed samples (see below, and Methods), no obvious correlation is observed between capacitance and average pore size (Fig. ), nor BET surface area (Fig. ), suggesting that structural features other than pore 100 size and surface area may govern the capacitance. Finally, oxygen content from X-ray photoelectron spectroscopy (XPS) measurements also did not show a clear correlation with capacitance (fig. ).