| 摘要 |
PROBLEM TO BE SOLVED: To provide a power storage device in which damage on a separator can be suppressed when welding a case.SOLUTION: A lithium ion secondary battery 11 includes an electrode body 19 in which a positive electrode sheet 21 and a negative electrode sheet 31 are laminated with a separator 18 interposed therebetween, and a case 13 for housing the electrode body 19 and an electrolyte. The case 13 includes a box-shaped body member 14 including a bottom wall 14a and a sidewall 14b formed to extend from the peripheral edge thereof and having an opening in one surface, and housing the electrode body 19, and a lid member 17 covering the opening 14 of the body member 14. The lid member 17 includes a main part 17d and a step part 17b thinner than the main part 17d along the peripheral edge of the lid member 17. On the inside of the lid member 17, a groove 45 opening to the electrode body 19 side is formed by the step part 17b and the body member 14. The body member 14 and the lid member 17 are welded along the step part 17b. |
