An initial series of activated nanoporous carbons showed increasing gravimetric capacitances as the synthesis temperature was decreased from 700 to 600 ℃, both at 0.05 A g -1 as well as at higher current densities up to 2 A g -1 (Figure , Figures and), with the rectangular cyclic voltammograms and predominantly linear constant charge-discharge curves indicating double-layer capacitance behaviour.