JP3487155B

• Format: Patent
• Language: English
• Published: 13.01.2004
• Edition: 7
• Subjects: ARTIFICIAL STONE; BASIC ELECTRIC ELEMENTS; CEMENTS; CERAMICS; CHEMISTRY; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; COMPOUNDS THEREOF; CONCRETE; ELECTRICITY; INORGANIC CHEMISTRY; LIME, MAGNESIA; METALLURGY; NON-METALLIC ELEMENTS; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; REFRACTORIES; SLAG; TREATMENT OF NATURAL STONE

PROBLEM TO BE SOLVED: To obtain a lithium secondary battery of high capacity with excellent cycling characteristics and rapid charge/discharge characteristics by specifying the aspect ratio, compression degree, crystal interlamellar spacing, and specific surface area of carbon particles to be used in the above battery. SOLUTION: The subject carbon particles to be used in the other subject lithium secondary battery is so designed as to be <=5 in aspect ratio, <=25% in compression degree shown by the formula, and in addition, <=3.4 in crystal interlamellar spacing (d) (002) to afford the battery with high capacity; further, the carbon particles is so designed as to be <=8 m /g in specific surface area to make the irreversible capacity at 1st cycle of the battery lower to effect excellent cyclic characteristics of the battery; besides, it is preferable that a plurality of flat particles among the carbon particles are aggregated or coupled together so that their orientation planes are nonparallel with one another. The subject carbon particles can be obtained, for example, by the following process: graphitizable aggregate or graphite, a graphitizable binder and graphitizing catalyst are mixed together and then molded to a specified shape, and the resulting graphite precursor is heat-treated in a non-oxidative atmosphere.