| 摘要 |
<p>A negative electrode material for lithium ion secondary battery whose main raw material is a powdery graphite covered with a thermoplastic resin of 20 wt% or less carbonization yield so that the amount of a product of carbonization of the thermoplastic resin is 10 pts.wt. or less per 100 pts.wt. of graphite powder, characterized in that the powdery graphite covered with the thermoplastic resin exhibits a cumulative volume of 0.012 to 40 μm diameter pores, as measured by the mercury penetration method, having been increased 5% or more over that before the thermoplastic resin covering; has a volume of mesopores defined by IUPAC and measured according to the BJH method from the desorption isotherm defined by IUPAC, of 0.01 cc/g or less, which volume is 60% or less of that before the thermoplastic resin covering; and an average particle diameter, as measured by a laser scattering particle size distribution meter, of 10 to 50 μm exhibiting a ratio of standard deviation to the average particle diameter (σ/D) of 0.02 or below.</p> |
