摘要 |
In a lithium ion secondary battery including a positive electrode, a separator, a negative electrode, and a package body, the negative electrode includes simple substance silicon as a negative electrode active material, and a negative electrode binder, and is doped with lithium, and the following formulas (1) and (2) are satisfied: 1.2 ‰¤ M a / M c ‰¤ 1.9 1.0 < M a / M c + M Li < 1.6
wherein an amount of lithium inserted into the negative electrode until the negative electrode reaches a potential of 0.02 V with respect to metal lithium is M a (a number of atoms), an amount of lithium released from the positive electrode until the positive electrode reaches a potential of 4.3 V with respect to metal lithium is M c (a number of atoms), and an amount of lithium with which the negative electrode is doped is M Li (a number of atoms). |