NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY AND PROCESS FOR PRODUCTION THEREOF

A nonaqueous electrolyte secondary battery includes a positive electrode (4), a negative electrode (5), a porous insulating layer (6), and a nonaqueous electrolyte. In the positive electrode (4), a positive electrode mixture layer (4B) is provided on at least one surface of a positive electrode current collector (4A). A tensile extension percentage of the positive electrode (4) is 3.0% or more. The positive electrode current collector (4A) contains iron. A porosity of the positive electrode mixture layer (4B) is 17% or less.