| 摘要 |
PROBLEM TO BE SOLVED: To provide a secondary battery of which a copper-based electrode has high tensile strength with little deterioration with the lapse of time, of which discharging capacity decrease is slight, and in which electrode rupture hardly occurs by adding a specified amount of carbon to a copper foil to be used as the electrode of the secondary battery. SOLUTION: In a copper foil to be used for an electrode of a secondary battery, at least 0.0018wt.% of carbon is added to pure copper. Consequently, the tensile strength in an initial period is improved and at the same time the processing stress or electrodeposition stress applied to copper can be thermally stabilized. Moreover, in the electrode for secondary batteries, an electrolytic copper foil is produced by controlling electrolysis conditions or an electrolytic copper foil produced by a conventional manner is rolled by wrapped rolls. As a result, a secondary battery of which discharge capacity decrease can be suppressed to a slight degree even by stress of repeated charging and discharging for a long duration and a negative electrode conductive body rupture hardly occurs can be obtained. |
