| abstract |
(57) [Problem] To provide a non-aqueous electrolyte secondary battery having stable performance, safe and high discharge capacity even when used at a high potential of 4.2 V or more of a positive electrode. It is in. A non-aqueous electrolyte secondary battery according to the present invention, which solves the above problems, comprises a non-aqueous electrolyte secondary battery having a positive electrode plate, a separator, and a negative electrode plate, wherein the separator has at least two single-layer films. A multilayer film having a microporous structure in which a plurality of layers are laminated, wherein the single-layer film of the multilayer film facing the positive electrode plate is a single-layer film made of polypropylene. |