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

摘要

A negative electrode material for nonaqueous secondary cells capable of realizing a nonaqueous secondary cell having a small charging/discharging irreversible capacity at the initial cycle and excellent in quick charging/discharging characteristic and cycle characteristic. The main component of the material is graphite particles. The median diameter in the volume-basis particle size distribution measured by the laser diffraction/scattering particle size distribution measuring method is 5 to 40 µm. The tap density is 0.7 g/cm³ or more. The specific area measured by the BET method is 0.2 to 8 m²/g. The average circularity is 0.83 to 1.00. When an electrode plate fabricated by a predetermined electrode plate fabrication method is subjected to X-ray diffraction, the graphite crystal orientation ratio I₁₁₀/I₀₀₄ on the electrode plate is 0.08 or more where I₁₁₀ is the wide-angle X-ray diffraction peak area of the (110)-face peak in the range 2?=76.5° to 78.5° of the graphite particles on the electrode plate and I₀₀₄ is the wide-angle X-ray diffraction peak area of the (004)-face peak in the range 2?=53.5° to 56°.