Abstract: The present invention provides:a vitreous carbon-active carbon composite material wherein the vitreous carbon is derived from a polycarbodiimide resin;a process for producing the above vitreous carbon-active carbon composite material, which comprises firing a mixture of a polycarbodiimide resin and an active carbon, or a molded article of desired shape prepared from said mixture, in a non-oxidizing atmosphere; anda polarizable electrode for use in electric double layer capacitor, which consists of the above vitreous carbon-active carbon composite material.Said electrode is free from the drawbacks of prior art, has a low internal resistance, causes a low degree of powder detachment, has large electric capacitance per unit weight and per unit volume, and can be produced easily, quickly and inexpensively.

Abstract: The present invention provides:a polarizable electrode for use in electric double-layer capacitor, which is made of a carbon composite material composed mainly of:100 parts by weight of an activated carbon,0.05 parts by weight of an amorphous carbon,0.1-1,000 parts by weight of a conductive agent, and0.03-90 parts by weight of a fibrillated carbon; andan electric double-layer capacitor comprising at least one pair of a positive electrode and a negative electrode each containing the above polarizable electrode and each impregnated with an electrolytic solution.The above polarizable electrode and electric double-layer capacitor are substantially free from the drawbacks of conventional polarizable electrodes and conventional electric double-layer capacitors, have a low internal resistance and a long life, and can be charged with or can discharge a large electric current of several amperes to several hundreds of amperes momentarily.

Abstract: The present invention providesa carbon composite material which is a molded material comprising (a) an expanded graphite powder and (b) a thermoplastic resin or a thermosetting resin or a fired product of the thermosetting resin, and the expanded graphite powder (a) being dispersed in the component (b); wherein the expanded graphite powder has an average particle diameter of 5-12 .mu.m and at least 80% of the total particles of the expanded graphite powder have particle diameters of 0.1-20 .mu.m; anda process for producing a carbon composite material, which comprises mixing and dispersing a thermoplastic or thermosetting resin and the expanded graphite powder as mentioned above, and then pressure-molding the resulting mixture at room temperature to 400.degree. C., or a process for producing a carbon composite material, which comprises mixing and dispersing a thermosetting resin and the expanded graphite powder as mentioned above, pressure-molding the resulting mixture at room temperature to 400.degree. C.

Abstract: An electric double-layer capacitor including, as the positive electrode and the negative electrode, a material obtained by adhering a polarizable electrode on one or both sides of a conductive material by the use of a conductive adhesive, in which capacitor the polarizable electrodes are formed by a carbon material composed mainly of active carbon, amorphous carbon and expanded graphite, or the conductive adhesive is composed mainly of a resin and expanded graphite, or the polarizable electrodes are formed by a carbon material composed mainly of active carbon, amorphous carbon and expanded graphite and the conductive adhesive is composed mainly of a resin and expanded graphite.The electric double-layer capacitor has alleviated the drawbacks of the prior art, has a low internal resistance, gives substantially no change in internal resistance when subjected to repeated discharging, and has a long life.