SECONDARY BATTERY

摘要

A secondary battery comprising a band-like positive plate including a positive electrode current collector and a positive electrode mix layer carried on the positive electrode current collector, a band-like negative plate including a negative electrode current collector and a negative electrode mix layer carried on the negative electrode current collector, and a band-like separator arranged between the positive plate and the negative plate. The positive and negative plates are wound with the separator interposed therebetween to constitute a plate group. The positive plate has an exposed part of the positive electrode current collector where the positive electrode mix layer is not formed in the vicinity of a first end part on the start-of-winding side and a positive electrode lead connected with the exposed part. A first round adjacent to the outside of the connection portion of the positive electrode lead with the separator interposed therebetween and a second round adjacent to the outside of the first round with the separator interposed therebetween are composed of a part of the negative plate carrying the negative electrode mix layer.