The present invention relates to a
supercapacitor, also known as an electrical double-layer
capacitor or ultracapacitor, having
electrode material comprising single-wall carbon nanotubes. The carbon nanotubes can be derivatized with functional groups. The
electrode material is made by preparing a
polymer-
nanotube suspension comprising
polymer and nanotubes, forming the
polymer-
nanotube suspension into a polymer-
nanotube composite of the desired form, carbonizing the polymer-nanotube composite to form a carbonaceous polymer-nanotube material, and activating the material. The
supercapacitor includes
electrode material comprising activated carbonaceous polymer-nanotube material in contact with current collectors and permeated with an
electrolyte, which may be either fluid or
solid. In the case of a fluid or compressible
electrolyte, an
electrolyte-permeable separator or spacer is interposed between the electrodes to keep the electrodes from shorting. The
supercapacitor made with electrodes comprising underivatized single-wall carbon nanotubes and polymer that has been carbonized and activated appears to operate as a non-Faradaic supercapacitor.