SECONDARY BATTERY

To make it easier for an electrolyte solution to return to a wound electrode body.SOLUTION: A secondary battery 1 includes a case 2, a wound electrode body 3 housed in the case 2 and formed by winding a positive electrode sheet 32, a negative electrode sheet 33, and a separator sheet 31 around a predetermined center axis Oc, a sheet-shaped insulating sheet 6 held between an inner surface of the case 2 and an outer surface of the wound electrode body 3, a nonaqueous electrolyte solution 7 included in the wound electrode body 3, and a pair of cover members 8 and 9 disposed so as to cover both end parts 3A and 3B of the wound electrode body 3 in a center axis direction, sectioning between each of both end parts 3A and 3B and the inner surface of the case 2, and having non-transparency to the nonaqueous electrolyte solution 7.SELECTED DRAWING: Figure 3 【課題】捲回電極体への電解液の戻り易さを向上させる。【解決手段】二次電池１は、ケース２と、ケース２に収容され、正極シート３２、負極シート３３およびセパレータシート３１を所定の中心軸Ｏｃ周りに捲回してなる捲回電極体３と、ケース２の内面と、捲回電極体３の外面との間に介在するシート状の絶縁シート６と、捲回電極体３の内部に含まれる非水電解液７と、中心軸方向における捲回電極体３の両端部３Ａ，３Ｂをそれぞれ覆うように配置され、該両端部３Ａ，３Ｂのそれぞれと、ケース２の内面との間を仕切りかつ非水電解液７に対して非透過性を有する一対のカバー部材８，９を備える。【選択図】図３