Patent ID: 7695854

Claim:
A lithium secondary battery comprising: a positive electrode comprising a strip-shaped positive electrode current collector and a positive electrode active material layer carried on each surface of said positive electrode current collector; a negative electrode comprising a strip-shaped negative electrode current collector and a negative electrode active material layer carried on each surface of said negative electrode current collector; a separator interposed between said positive electrode and said negative electrode; and a non-aqueous electrolyte, wherein an exposed portion carrying no active material layer is formed on a substantially center portion in a longitudinal direction of at least one of said positive electrode current collector and said negative electrode current collector, a current collecting lead is connected to said exposed portion, and a first heat resistant layer is formed such that said first heat resistant layer faces at least part of said current collecting lead, and wherein a second heat resistant layer is formed such that said second heat resistant layer faces an entire surface of an active material layer that is located across from said current collecting lead, said second heat resistant layer is porous, and said first heat resistant layer is thicker than said second heat resistant layer.