Negative electrode material for nonaqueous secondary cells, negative electrode for nonaqueous secondary cells, and nonaqueous secondary cell

A negative electrode material, which contains graphite particles as a main component, for a nonaqueous secondary battery, characterized in that:

• the median diameter of the graphite particles is 5 μm or more, and 40 μm or less in the volume-basis particle size distribution based on the laser diffraction/scattering particle size distribution measurement;
• the tapping density is 0.7 g/cm3 or more;
• the specific surface area measured by a BET method is 0.2 m2/g or more, and 8 m2/g or less;
• and
• when an electrode is produced from the negative electrode material by the following method for manufacturing an electrode and the surface of the resulting electrode is measured with a laser shape measurement microscope, the skewness (Rsk), which is prescribed by JIS B 0601, of the surface roughness curve is −1.7 or more, and 0 or less,
• [Method for Manufacturing Electrode]
• a slurry is prepared by adding 1 part by weight of aqueous dispersion of styrene-butadiene rubber in terms of solid content and 1 part by weight of carboxymethyl cellulose (molecular weight 250,000 to 300,000) aqueous solution in terms of solid content to 100 parts by weight of the negative electrode material, the resulting slurry is applied to a current collector formed from copper foil having a thickness of 18 μm by using a doctor blade in such a way that 10±0.1 mg/cm2 of the negative electrode material in terms of weight after drying is adhered, followed by drying, and consolidation is performed by pressing once with a roll press (calender) while a press load is adjusted in such a way that the electrode density (exclusive of the copper foil) becomes 1.63±0.03 g/cm3.