| 摘要 |
PROBLEM TO BE SOLVED: To obtain electrode foil having less spotted luster for an electrolytic capacitor by reducing the possibility that non-etched portions remain. SOLUTION: This electrode foil for an electrolytic capacitor is the specific aluminum foil etched. The specific aluminum foil contains not less than 99.98% aluminum and 0.3-0.6 ppm lead. Manyγ-Al2O3 crystals exist relatively uniformly in the film of the oxide on the surface of the aluminum foil. In addition, there are a lot of exposed lead and lead compounds on the surface of the aluminum foil. The lead and lead compounds are exposed in such a manner that a part of the current-potential curve, which is determined by setting the aluminum foil as the cathode, follows the Tafel's formula (η=α+β×logi), and thatβin the formula falls within a range of 0.08 to 0.14 andαfalls within a range of 0.9 to 1.3. In the Tafel's formula,ηrepresents overvoltage (V), i represents current density (A/cm2), andα(V) andβ(V/decade) are constants.
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