| 摘要 |
PROBLEM TO BE SOLVED: To accomplish increase in energy density and improvement of charging-discharging efficiency by using a composite carbon material consisting of a graphite material, which is prepared by heat treating and graphitizing a meso-carbon micro bead made of a mesophase micro sphere, and a slightly graphitizable carbon material, which is prepared by carbonizing a resin selected from a group consisting of phenol resin, furan resin and the like, as a negative electrode. SOLUTION: As a graphite material, a graphitized carbon material, which is prepared by heat treating a meso-carbon micro bead made of petroleum pitch, is used. As a slightly graphitizable carbon material, a carbon material, which is prepared by heat treating and carbonizing phenol resin, is used. A composite carbon material consisting of these carbon materials is used as a negative electrode. In this case, a mixing ratio of the slightly graphitizable carbon material in the composite carbon material ranges from 10% to 50% on a weight base. In this way, in which the slightly graphitizable carbon is mixed with the graphite material consisting of mesophase group carbon material, fracture of the carbon granule due to pressurization can be prevented, while high capacity and excellent charging-discharging efficiency can be accomplished. |
