非水電解質二次電池

Abstract

This non-aqueous electrolyte secondary battery is characterized by comprising: a wound electrode body (14) in which a positive electrode and a negative electrode are wound via a separator (13); and a non-aqueous electrolyte. Said battery is also charaterized in that: the separator (13) has a porous base material and a heat-resistance porous layer (32) formed on the porous base material and opposing at least one of the positive electrode and the negative electrode; and when the separator (13) is divided into five parts in the width direction and the five divided regions are defined as a region A positioned on one end of the separator (13) in the width direction, a region B positioned on the other end of the separator in the width direction, a region C positioned in the center of the separator in the width direction, a region D positioned between the region A and the region C, and a region E positioned between the region B and the region C, then the void ratio of the region D and the region E is greater than the void ratio of the region A, the region B, and the region C.

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