MODIFIED NATURAL GRAPHITE PARTICLE AND METHOD FOR PRODUCING SAME

摘要

Disclosed is a natural graphite particle forming a negative electrode active substance for a non-aqueous electrolyte secondary battery, characterized by having a circularity of 0.93 - 1.0 and a surface roughness of 1.5% of the largest particle diameter. Also disclosed is a method for producing modified particles of natural graphite in which grinding and spheronizing are carried out by applying an impact force to the natural graphite particles and there is a process for obtaining intermediate particles with a circularity of 0.93 - 1.0 as well as a process for obtaining the modified natural graphite particles by performing surface smoothing using mechanical milling of the intermediate particles obtained.