A preparation method for reducing leakage current of low-voltage electrode foil for aluminum electrolytic capacitors

Abstract

The invention discloses a preparation method capable of reducing leakage current of low voltage electrode foil for an aluminum electrolytic capacitor. The preparation method comprises the following steps: dipping the low-voltage corrosion foil in a silane coupling agent solution; applying voltage to perform first-stage formation; performing second-stage formation and third-stage formation on the low-voltage corrosion foil being subjected to first-stage formation in sequence, and then putting the low-voltage corrosion foil in boric acid and borax; performing primary reverse charging; performingfourth-stage formation after high-temperature heat treatment; performing phosphoric acid passivation treatment; performing fifth-stage formation; performing secondary reverse charging; and drying toobtain the low voltage electrode foil for the aluminum electrolytic capacitor. According to the preparation method disclosed by the invention, the first-stage formation treatment with a silane coupling agent, boiling water treatment after the third-stage formation and reverse charging treatment are combined, thereby not only effectively reducing the content of hydrated alumina on the foil surface,but also well protecting the pore structure of an oxide film. The prepared low-voltage electrode foil has high specific capacitance and low loss, significantly-reduced leakage current; the anti-ripple current ability of the electrode foil is improved; and the service life of capacitor is prolonged.

Description

technical field [0001] The invention relates to the technical field of preparation for reducing the leakage current of electrode foils, in particular to a preparation method for reducing the leakage current of low-voltage electrode foils for aluminum electrolytic capacitors. Background technique [0002] With the development of miniaturization of electronic equipment, there is an urgent need to reduce the volume and increase the specific capacity of aluminum electrolytic capacitors. Anodized foil, as the core material in aluminum electrolytic capacitors, plays a decisive role in various characteristics of capacitors. The existing low-voltage anode foil formation process is generally three-stage formation, high-temperature heat treatment, four-stage formation in boric acid and borax solution, adipate aqueous solution, and finally immersion treatment in ammonium dihydrogen phosphate solution. This formation process is adopted. After the prepared low-voltage electrode foil is m...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to overcome the defect and deficiency of excessive leakage current of the existing low-voltage electrode foil for aluminum electrolytic capacitors, and provide a preparation method for reducing the leakage current of low-voltage electrode foil for aluminum electrolytic capacitors. Agent modification treatment of hydrated alumina, boiling depolarization treatment and reverse electrification treatment, on the one hand, promoted the conversion of hydrated alumina film to dense porous alumina film, on the other hand, well protected the porous layer structure on the surface, The synergistic effect effectively reduces the leakage current of the low-voltage electrode foil and improves the ability to withstand large ripple currents

Images