| 摘要 |
PROBLEM TO BE SOLVED: To provide a lithium secondary battery that can prevent cut of a negative electrode collector accompanying charge and discharge cycle and has a good cycle property. SOLUTION: In a lithium secondary battery having a positive pole, a negative pole and an electrolyte, an electrolytic metal foil as a negative electrode collector has tensile strength of not less than 400 N/mm2 and breaking elongation of not less than 7% and the product of the tensile strength and the breaking elongation of not less than 2,800 N/mm2. Expressing the roughness of the negative collector by a center average roughness Ra, the difference of the roughness between both sides thereof is preferably not more than 0.1 μm. |
