Method for producing negative electrode material for high performance lithium ion secondary battery using natural graphite

摘要

PPROBLEM TO BE SOLVED: To provide a negative electrode material for a lithium ion secondary battery having high capacity by using natural graphite, having small capacity loss in initial charge/discharge, and having quick charging capability and an excellent cycle characteristic, and to provide a manufacturing method of the negative electrode material advantageous for mass production at a low cost. PSOLUTION: This negative electrode material for a lithium ion secondary battery is prepared by granulating and molding natural graphite powder into a nearly spherical shape by using a binder and by baking it after impregnating and coating binder pitch. This manufacturing method of the negative electrode material includes a process wherein the binder pitch is added to graphite particles obtained by granulating and molding the natural graphite into the nearly spherical shape by using the binder, and they are heated and mixed and then baked at 800-1,400C in a non-oxidizing atmosphere. PCOPYRIGHT: (C)2004,JPO