COMPOSITE GRAPHITIC PARTICLE, ITS MANUFACTURING METHOD, NEGATIVE ELECTRODE FOR LITHIUM ION SECONDARY BATTERY, AND LITHIUM ION SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide composite graphitic particles having high discharge capacity and initial charge-discharge efficiency as a negative electrode material for a lithium ion secondary battery, and capable of providing an excellent high-rate characteristic and an excellent cycle characteristic, to provide a method for manufacturing the composite grophitic particles with high productivity by restraining fusion in graphatization, to provide a negative electrode for a lithium ion secondary battery using the composite graphitic particles, and to provide a lithium ion secondary battery having the above battery characteristics.

SOLUTION: These composite graphitic particles are prepared by first forming a graphite granulated substance A formed by aggregating a plurality of scale-like graphite pieces, and then filling and coating the internal voids and the outside surfaces of the granulated substance A with carbonaceous layers B having crystallinity lower than the granulated substance A. The composite graphitic particles are characterized by that the carbonaceous layer B contains carbonaceous fine particles. This negative electrode for a lithium ion secondary battery is provided by using the composite graphitic particles. This lithium ion secondary battery is provided by using the negative electrode.

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