Patent ID: 7811696
Filing Date: 2010-10-12
Classification: H01M,Y02E,Y02P,Y10T

Abstract:
1. A lithium secondary battery comprising an electrode group obtained by winding a positive electrode and a negative electrode, said positive electrode including a positive electrode current collector and a positive electrode active material layer carried on said positive electrode current collector, said negative electrode including a negative electrode current collector and a negative electrode active material layer carried on said negative electrode current collector, an exposed portion on which said positive electrode active material layer is not carried being provided on said positive electrode current collector at at least one of an initial winding end and a final winding end of said positive electrode, an exposed portion on which said negative electrode active material layer is not carried being provided on said negative electrode current collector at at least one of an initial winding end and a final winding end of said negative electrode, wherein a heat-resistant layer including a filler and a binder is formed on said exposed portion of said negative electrode current collector excluding a boundary portion between an end of said negative electrode active material layer and said exposed portion of said negative electrode current collector, and the entire surface of said negative electrode active material layer on said negative electrode, at least one of an initial winding end and a final winding end of said negative electrode active material layer, each of which is provided with said heat-resistant layer, is opposite to said exposed portion of said positive electrode current collector, and said positive electrode comprises an insulating tape attached onto at least a part of said exposed portion of said positive electrode current collector that is opposite to said end of said negative electrode active material layer provided with said heat-resistant layer, said insulating tape including a substrate and an adhesive applied onto said substrate.