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 fabricate d. One was fabricated by hot-pressing without any binding materials, the ot her was synthesized through carbonization of a cured mixture of carbon nano tubes and phenol-formaldehyde resin. The specific surface area and total vo lume of the open pores were measured. Both are suitable for fabricating pol arizable electrodes of electric double-layer capacitors (EDLCs). In additio n, 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.