| 摘要 |
PROBLEM TO BE SOLVED: To prevent peeling and breakage of an electrode to improve cycle characteristics when used to configure a lithium ion secondary battery.SOLUTION: A collector for a lithium ion secondary battery has a plurality of pores inside. By having a composition in which, in a cross section in a direction crossing a principal plane of the collector, a ratio of the number of pores at a surface layer part on the principal plane side of the collector is higher than a ratio of the number of pores at the center part, peeling and breakage of an electrode is prevented, and thus excellent cycle characteristics when used to configure a lithium ion secondary battery is obtained. |
