Having established that both ion adsorption capacities and graphene-like domain sizes are important parameters in determining capacitance, we briefly speculate why this is the case here. First, the ion adsorption capacities indicate the accessibility of the ions to the sites where the charge is stored, so it is logical that this correlates with capacitance. Second, to explore the role of the graphene-like domain size further, we plotted the capacitances of the nanoporous carbons against the "edge length per unit area" (Figure ), which is a parameter defined to describe the approximate quantity of domain edges per unit area of graphene-like domains (see Methods). The value of edge length per unit area is larger for nanoporous carbons with smaller graphene-like domains (0.2 for HTC-600) and vice versa (0.097 for HTC-1000_1).