| 摘要 |
PROBLEM TO BE SOLVED: To provide: a negative electrode for a lithium ion secondary battery, which has a high capacity and enables fast charge and discharge; and a lithium ion secondary battery.SOLUTION: A negative electrode 2 for a lithium ion secondary battery according to the present invention comprises: a current collector 5; and an active material layer 6 formed on a surface of the current collector 5. The active material layer 6 has holes 7 in its surface. The active material layer 6 includes an active material of which the density is 70-83% of the true density of the active material, and has a thickness of 100-1000 μm. So, the active material layer is arranged to have more active material. In the case of using the negative electrode for a lithium ion secondary battery, the exchange of electrons and the infiltration and desorption of lithium ions are caused at a deep position from the surface of the active material layer 6 in a thickness direction in addition to a position in the surface of the active material layer 6. Therefore, a high-capacity lithium ion secondary battery can be provided, which enables the effective use of the active material at a deep position from the surface of the active material layer 6 in the thickness direction.SELECTED DRAWING: Figure 1 |
