NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a battery excellent in shelf life by specifying the difference between the inner circumference of a bag-like cell case containing a generating element and the outer circumference of the generating element and the thickness of the generating element. SOLUTION: This nonaqueous electrolyte secondary battery comprises an elliptic wound generating element 6 housed in a bag-like cell case so that its central axis is vertical to the opening surface of the gag-like cell case. The difference between the inner circumference of the bag-like cell case and the outer circumference of the generating element 9 is set to 4 mm or less, and the thickness of the generating element 9 is set to 6 mm or less. A material laminate resin film case as the airtight sealing bag-like cell case is formed of a 12-μm PET film as a surface protecting layer 6 of the outermost layer, a 9μm aluminum foil as a metal barrier layer 7, and a 100μm acid modified polyethylene layer as a thermal fusing layer 8. The PET film of the surface protecting layer 6 and the aluminum foil of the metal barrier layer 8 are adhered using an urethane adhesive. A positive electrode lead terminal 4 and a negative electrode lead terminal 5 consist of metal conductors 50-100μm thick of copper, aluminum, nickel or the like.