Patent ID: 7927729

Claim:
A secondary battery comprising an electrode assembly in which a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are spirally wound with a strip-shaped separator interposed therebetween, said positive electrode plate comprising a positive electrode current collector and a positive electrode material mixture layer carried on said positive electrode current collector, and said negative electrode plate comprising a negative electrode current collector and a negative electrode material mixture layer carried on said negative electrode current collector, wherein said positive electrode plate has, in a vicinity of a first end at an initial winding side, an exposed portion of said positive electrode current collector having said positive electrode material mixture layer not formed thereon, and a positive electrode lead connected to said exposed portion, and wherein a first winding turn outwardly adjacent to a connecting portion of said positive electrode lead with said separator interposed therebetween, and a second winding turn outwardly adjacent to said first winding turn with said separator interposed therebetween, comprise a portion of said negative electrode plate carrying said negative electrode material mixture layer, and comprise a portion of said positive electrode current collector having said positive electrode material mixture layer not formed thereon.