Method for manufacturing electrode for aluminum electrolytic capacitor

A method for manufacturing an electrode for an aluminum electrolytic capacitor, the method comprising:

• (i) a purified water boiling step of boiling an aluminum electrode in purified water, and (ii) a forming step of performing formation upon the aluminum electrode after the purified water boiling step until a film withstand voltage of 200 V or higher is reached,
• wherein the aluminum electrode is a porous aluminum electrode constituted by an aluminum core and a porous layer formed by sintering powdered aluminum layered upon a surface of the aluminum core;
• wherein the forming step (ii) comprises at least (a) a first forming process of performing formation in an aqueous solution of ammonium adipate having a temperature of 80° C. or less and (b) a second forming process of performing formation in an inorganic-acid-based forming solution after the first forming process is performed;
• wherein the first forming process (a) increases a power source voltage to firstly reach a final forming voltage in the forming step;
• wherein the first forming process (a) further performs an intermediate process of immersing the aluminum electrode in an aqueous phosphoric acid solution before the power source voltage firstly reaches the final forming voltage;
• wherein the second forming process (b) is performed after the power source voltage firstly reaches the final forming voltage;
• and
• wherein when a thermal depolarization process of heating the aluminum electrode is first performed after performing the first forming process, a water washing process is performed upon the porous aluminum electrode for at least five minutes before the thermal depolarization process.