MANUFACTURING METHOD OF AMORPHOUS CARBON MATERIAL FOR LITHIUM ION SECONDARY BATTERY NEGATIVE ELECTRODE AND LITHIUM ION SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide an amorphous carbon material for lithium ion secondary battery negative electrodes which makes it possible to restrain capacity degradation due to repeated discharge and charge cycles, storage in a charged state, and floating charges.

SOLUTION: A manufacturing method of an amorphous carbon material for lithium ion secondary battery negative electrodes includes: a step for pulverizing and classifying a coking coal composition obtained by subjecting to coking treatment of a heavy oil composition according to a delayed coking process to obtain powder of the coking coal composition; a step for applying compressive shear stresses to the powder of the coking coal composition to obtain a carbide precursor; and a step for carbonizing the carbide precursor by heating in an inert atmosphere at a temperature of 900°C to 1500°C so that the crystal size Lc(002) calculated from a (002) diffraction line measured by X-ray wide-angle diffractometry is in the range of 2 nm to 8 nm. The coking coal composition has a H/C atom ratio of hydrogen atom H to carbon atom C of 0.30 to 0.50 and a micro-hardness of 7 to 17 mass%.

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