Abstract: The present invention is related to ultracapacitors (or supercapacitors) and to the carbon electrode materials for ultracapacitors. A ultradocapacitor according to the invention comprises at least one pair of oppositely charged microporous carbon electrodes composed of an electrochemically active carbon material wherein an active carbon surface is modified with plurality of atoms or functional groups with a free electron pair covalently bound to hexagonal carbon, and an electrolyte containing ions forming an electrical double layer on the surface of electrically charged carbon electrode and a component changing a state of charge during recharging of the ultracapacitor. The carbon is preferably CDC (carbon derived carbon) activated by high temperature (600-1000° C.) chlorine treatment.