| 摘要 |
PROBLEM TO BE SOLVED: To improve a service capacity and initial efficiency by using a graphite material obtained by baking mesocarbon micro-beads under the existence of a boron compound and having the degree of graphitization of a specific value or above for a negative electrode. SOLUTION: The graphite having the most proximate net face corresponding to the probability of a graphitic arrangement and having the degree of graphitization P1 of 0.72 or above obtained by the Fourier analysis of the intensity distribution of the two-dimensional diffraction in the X-ray diffraction diagram deformed as the graphitization of carbon progresses is used. The regular layer structure property of carbon is lowered, the ratuo of the AA-type and AB-type of the laminated structure of the adjacent carbon net face is changed, the portion intercalated with lithium is increased, and nearly the theoretical service capacity based on the composition of the LiC6 -type graphite interlayer compound generated by charge/discharge reactions is obtained. The mesocarbon micro-beads obtained by separating and refining the spherulite generated when an organic material such as coal tar is processed at the prescribed pressure and temperature from a reaction liquid are baked under the presence of a simple substance or a compound of boron for use as a graphite material. |
