| 摘要 |
PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery of which the output density is improved. SOLUTION: This lithium ion second battery consists of a two-layer active material layer having different diameter of active-material particles, including a positive electrode that can perform storage/discharge of lithium ions, a negative electrode that can perform storage/discharge of lithium ions, and a nonaqueous electrolytic liquid. However, the two-layer active material layer have different diameter of active-material particles, namely, the active-material particle diameter is 5 μm or less, on the collector side of the active-material layer, and the active-material particle diameter is 5 μm or more on the separator side of the active-material layer. |
