NEGATIVE ELECTRODE MATERIAL FOR NONAQUEOUS SECONDARY CELLS, NEGATIVE ELECTRODE FOR NONAQUEOUS SECONDARY CELLS, AND NONAQUEOUS SECONDARY CELL

摘要

A negative electrode material for a nonaqueous secondary battery capable of realizing a nonaqueous secondary battery having a small charging/discharging irreversible capacity at an initial cycle, exhibiting an excellent high-rate charging/discharging characteristics and an excellent cycle performances, and having no electrodeposition problem is provided. The main component of the material is graphite particles. 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 of the negative electrode material is 0.7 g/cm 3 or more. The specific surface area measured by a BET method is 0.2 m 2 /g or more, and 8 m 2 /g or less. When an electrode is produced from the negative electrode material by a predetermined method for manufacturing an electrode, and the surface of the resulting electrode is measured with a laser shape measurement microscope, the skewness (Rsk) prescribed by JIS B 0601 of the surface roughness curve is -1.7 or more, and 0 or less.