| 摘要 |
A nonaqueous electrolyte secondary battery includes an electrode group (8) formed by winding a positive electrode (4) and a negative electrode (5) with a porous insulating layer (6) interposed therebetween. The positive electrode (4) includes a positive electrode material mixture layer (4B) and a positive electrode current collector (4A). The positive electrode material mixture layer (4B) has a porosity of 20% or lower. µ ‰¥ ·/Á is satisfied, where · is the thickness of the positive electrode material mixture layer (4B) on a surface located inside in the radial direction of the electrode group (8) of surfaces of the positive electrode current collector (4A), Á is the minimum radius of curvature of the positive electrode (4), and µ is a tensile extension in the winding direction of the positive electrode (4). The frequency distribution curve for the particle sizes of a positive electrode active material has two or more peaks. |
