Method of producing aluminum foil for electrolytic capacitors and product thereof

An electrochemical cell, for etching an aluminum foil suitable for use in an electrolytic capacitor, which comprises:

• an etch tank having an etch electrolyte comprising at least one oxidizing compound selected from the group consisting of sodium perchlorate, sodium persulfate, sodium pyrosulfate and mixtures thereof disposed therein and containing at least a first and a second compartment each containing (I) an etch electrolyte which may be the same or different from the etch electrolyte contained in the etch tank and in the other said compartment;
• (ii) a titanium cathode plate, and (iii) a perfluorinated polymer ion exchange membrane separator portion effective to retard depletion of the oxidizing compound present in the electrolyte by reduction at the cathode, said first and second compartments being arranged in the etch tank with the ion exchange membrane separator portions in facing relationship one to the other;
• and
• an aluminum foil anode present in the etch tank and disposed between each said first and second compartments.