Processing and Performance of Electric Double-Layer Capacitors with Block-Type Carbon Nanotube Electrodes

Two kinds of block-type porous materials of carbon nanotubes were fabricated. One was fabricated by hot-pressing without any binding materials, the other was synthesized through carbonization of a cured mixture of carbon nanotubes and phenol-formaldehyde resin. The specific surface area and total volume of the open pores were measured. Both are suitable for fabricating polarizable electrodes of electric double-layer capacitors (EDLCs). In addition, the block-type carbon nanotube electrodes enable one to fabricate a box-type cell. A cell with large capacitance, 150 F at 1.0 V, was developed by using sulfuric acid as the electrolyte.