POWER STORAGE DEVICE

PROBLEM TO BE SOLVED: To prevent deformation at the end of a separator due to heat, generated at a weld zone when welding a positive electrode and a positive electrode conductive member and a negative electrode and a negative electrode conductive member.SOLUTION: In a secondary battery 10 as a power storage device, a flat electrode assembly 12 formed by winding a strip positive electrode 13 and a strip negative electrode 14, while interposing a strip separator 15, is housed in a case 11, and the ends 13c, 14c of the positive electrode 13 and negative electrode 14 are arranged at the bend 12b of the electrode assembly 12. The end 15a of the separator 15 is arranged at a place where the distance L1 of the weld range 23 of the positive electrode 13 and a positive electrode conductive member 19 and the negative electrode 14 and a negative electrode conductive member 20 and the end 15a of the separator 15, in the winding direction, is equal to or longer than the distance of the weld zone 19a of the positive electrode 13 and the positive electrode conductive member 19 and the positive electrode active material layer and the distance of the weld zone 20 of the negative electrode 14 and a negative electrode conductive member 20 and the negative electrode active material layer.SELECTED DRAWING: Figure 1 【課題】正極と正極導電部材及び負極と負極導電部材との溶接時に溶接箇所で発生する熱によるセパレータの終端の変形を防止する。【解決手段】蓄電装置としての二次電池１０は、帯状の正極１３と帯状の負極１４との間に帯状のセパレータ１５が介在する状態で捲回された扁平な電極組立体１２が、ケース１１内に収容されており、正極１３及び負極１４の終端１３ｃ，１４ｃが電極組立体１２の湾曲部１２ｂに配置されている。セパレータ１５の終端１５ａは、正極１３と正極導電部材１９及び負極１４と負極導電部材２０の溶接範囲２３とセパレータ１５の終端１５ａとの捲回周方向の距離Ｌ１が、正極１３と正極導電部材１９との溶接箇所１９ａと正極活物質層との距離及び負極１４と負極導電部材２０との溶接箇所２０ａと負極活物質層との距離以上となる箇所に配置されている。【選択図】図１