ELECTROLYTIC CAPACITOR

PROBLEM TO BE SOLVED: To extend the life of an electrolytic capacitor when it is used in a charge/discharge circuit where a large differential voltage of short period is applied.SOLUTION: In the electrolytic capacitor using a capacitor element formed by winding or laminating an anode foil having an anode internal terminal and a cathode foil having a cathode internal terminal with a separator interposed therebetween, the end of the anode foil faces the cathode foil via the separator and the cathode internal terminal has an enlarged surface. Since a small area portion is eliminated in the cathode foil facing the anode foil, the charge/discharge characteristics are enhanced. Furthermore, in an electrolytic capacitor where a capacitor element formed by winding or laminating an anode foil having an anode internal terminal and a cathode foil having a cathode internal terminal with a separator interposed therebetween is impregnated with an electrolyte for driving, the cathode internal terminal is composed of an aluminum material and its surface is etched, and the concentration of iron of the etching layer is 40 ppm or lower.