| 摘要 |
PROBLEM TO BE SOLVED: To increase an initial capacity by increasing a coating amount and raise a capacity-keeping rate, in a lithium ion secondary battery having a negative electrode in which a Si alloy is used.SOLUTION: A lithium ion secondary battery comprises: a positive electrode including a positive electrode active material; a negative electrode arranged by coating the surface of a negative electrode collector with a negative electrode active material mixture including a negative electrode active material, a conductive assistant material and a binder; a separator disposed between the positive and negative electrodes; and an electrolyte. The negative electrode active material includes graphite and a Si alloy, and satisfies the following conditions: 0.43≤x≤9.0; and 8≤y<18, where x is a mass ratio of the graphite to the Si alloy, and y(mg/cm) is a coating amount of the negative electrode active material mixture.SELECTED DRAWING: Figure 3 |
