LITHIUM SECONDARY BATTERY AND ELECTRONIC EQUIPMENT USING IT

摘要

PROBLEM TO BE SOLVED: To provide a negative electrode material in which the reduction of discharge capacity accompanying the increase of charge and discharge cycle frequency is minimized by forming a coating layer mainly composed of an amorphous carbon material on the surface of a granular or fibrous crystalline carbon material contained in a negative electrode in mesh so as partially expose the substrate. SOLUTION: The covering ratio of an amorphous carbon covering the surface of a crystalline carbon material in mesh is 20-70 % by area ratio, and the thickness of the amorphous carbon is 1-10 nm. The granular or fibrous crystalline carbon material contained in a negative electrode preferably has an organic compound of aromatic cyclic structure contained in the amorphous carbon covering the surface in mesh. To form the film, the particle or fiber of the crystalline carbon material is dispersed into an aqueous solution in which an organic compound having an aromatic ring in the structure such as phthalic acid is dissolved. The aromatic ring having a geometrically flat structure is adsorbed onto the flat crystal surface having a developed graphite structure with the cyclic surface being substantially parallel to the flat surface.