| 摘要 |
The present invention is a negative electrode material for lithium ion secondary batteries which comprises granules including flake graphite, the inside of each granule having a porous structure configured of the flake graphite that has stacked in a non-parallel manner and that has been composited with a metal capable of being alloyed with lithium, wherein graphite and/or carbon having an average particle diameter not larger than 1/2 that of the flake graphite is adherent to the surface of the granules and is present in the inside thereof, and the surface and inside of each granule has been coated with pyrolytic carbon. The negative electrode material for lithium ion secondary batteries is characterized by comprising 50 parts by mass or more but less than 95 parts by mass of the flake graphite, 1-30 parts by mass of the metal, more than 5 parts by mass but not larger than 50 parts by mass of the graphite and carbon having an average particle diameter not larger than 1/2 that of the flake graphite, and 0.25-20 parts by mass of the pyrolytic carbon, relative to 100 parts by mass of the sum of the flake graphite and the graphite and carbon having an average particle diameter not larger than 1/2 that of the flake graphite. |
