| 摘要 |
PROBLEM TO BE SOLVED: To provide a negative electrode material capable of being suitably used for manufacturing a lithium ion secondary battery small in a characteristic difference between individuals.SOLUTION: A first half cell is manufactured by applying a negative electrode material on a copper foil, forming an electrode at a pressing pressure of 125 kg/cm, using lithium metal as a counter electrode, and using an electrolyte obtained by adding LiPFat a rate of 1 mol/dminto a mixed solvent including an ethylene carbonate and a diethyl carbonate mixed at a volume ratio of 1:1. A second half cell is manufactured in the same manner as for the first half cell except that the pressing pressure is 250 kg/cm. In a negative electrode material of the present invention, a relationship of X-X≤20 mAh/g is satisfied, where X[mAh/g] represents an initial discharge capacity per unit weight of the electrode included in the first half cell, and X[ mAh/g] represents an initial discharge capacity per unit weight of the electrode included in the second half cell. |
