GRAPHITE PARTICLE FOR ELECTRODE, ITS MANUFACTURING METHOD, NEGATIVE ELECTRODE FOR NONAQUEOUS SECONDARY BATTERY USING THE SAME, AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery having superior rapid charge and discharge property, overcharge property, and cycle characteristics.

SOLUTION: A heating treatment of 300 to 1,300°C is applied to graphite particles of an average particle diameter of 10 to 50 μm and a true density of 200kg/m3or more so as to make the weight decreasing rate of the graphite particles less than 30%, then mechanical surface reforming is applied to the graphite particles of a post-heating treatment to manufacture the graphite particles for an electrode with a powder density of 800 to 1,000kg/m3and a specific surface area of 3,000 to 6,000 m2/kg. A graphite paste having a viscosity of 2.0(Pa×s) or less is prepared under a condition of shear speed of 4 sec-1and a measurement temperature of 25°C and is processed into an electrode to make up a negative electrode of the nonaqueous electrolyte secondary cell.

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