| 摘要 |
PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery including a separator and an active material layer which has an uneven structure with a high aspect ratio, and capable of offering a large capacity and excellent high-speed charge-discharge behavior without causing damage to the separator.SOLUTION: The lithium ion secondary battery comprises: a first electrode including a first active material layer composed of a plurality of projecting first active material portions provided on a first collector; a second electrode including a second active material layer composed of a plurality of projecting second active material portions provided on a second collector; and a separator disposed between the first electrode and the second electrode. The first electrode and the second electrode are laminated so that the portions between the adjacent projecting second active material portions, and the projecting first active material portions face each other, and the size of the projecting first active material portions is greater than the space between the projecting second active material portions to prevent the projecting first active material portions from entering the space between the projecting second active material portions. |
