▎ 摘　　要

Carbons produced by calcination at 700 similar to 850 degrees C, of the materials derived from petroleum cokes and pitches consist of well-grown graphite-like layers with an average inter-layer distance of d(infinity 2) = 0.35 similar to 0.365 nm. Additional heat treatment of the carbon with KOH at 800 degrees C can provide the expansion of inter-layer distance up to d(infinity 2) = 0.36 similar to 0.385 nm and the latent ability of electrochemical intercalation of Et4N+ and BF4- in PC into the multi-graphene layers. Using the KOH-treated carbons as electrodes of EDLC, a high-density energy store such as 25 similar to 30 F/cm(3) of dry total electrodes operating at 3.5 similar to 4.0 V is available when the depth of the cell is rigidly restricted.