NEGATIVE ELECTRODE MATERIAL FOR LITHIUM ION SECONDARY BATTERY, AND METHOD OF MANUFACTURING THE SAME

摘要

An anode active material for a lithium ion secondary battery is provided to impart improved load characteristics, low-temperature charge characteristics and cycle characteristics to a lithium ion secondary battery. An anode active material(AM) for a lithium ion secondary battery comprises primary particles(NM) formed of graphite particles and secondary particles(SM) having a smaller particle diameter than the primary particles, wherein the surface of the primary particles are partially exposed to the exterior, and the secondary particles are attached to the primary particles by using no binder. The primary particles have a higher hardness than the secondary particles.