Pure inorganic acid formation process for positive electrode foil for high-voltage bolt type aluminium electrolytic capacitor

Abstract

The invention discloses a pure inorganic acid formation process for a positive electrode foil for a high-voltage bolt type aluminium electrolytic capacitor. The pure inorganic acid formation process is characterized by comprising the steps of dipping an etched foil into water for performing a dipping treatment to generate a hydrate film on the surface of the etched aluminium foil, then putting the etched aluminum foil, after the aluminum foil is subjected to the dipping treatment, into a dicarboxylic acid solution for further performing the dipping treatment, next putting the aluminum foil into a phosphate solution for performing a first time of formation to generate a dielectric oxide film on the surface of the aluminium foil; and then performing a second time of boric acid formation, and performing a roasting treatment and a phosphoric acid treatment to obtain the final positive electrode aluminium foil. According to the pure inorganic acid formation process for the positive electrode foil for the high-voltage bolt type aluminium electrolytic capacitor, the produced positive electrode foil is better in of electric property, low in current leakage, and high in hydration resistance, so that the formation process can particularly satisfy the high-quality demand of the high-voltage bolt type aluminium electrolytic capacitor; the service life of the high-voltage bolt type aluminium electrolytic capacitor can be prolonged, and the market competitiveness of the product is further enhanced; and in addition, experiments prove that the current leakage can be reduced by more than 28% by the formation process, and the service life of the aluminium electrolytic capacitor is improved by more than 1700 hours proved by an accelerated life test.

Description

technical field [0001] The invention relates to a forming process of an anode foil for a high-voltage bolt type aluminum electrolytic capacitor, in particular to a pure inorganic acid forming process. Background technique [0002] Anode foil is the key material for manufacturing high-voltage aluminum electrolytic capacitors. The life of high-voltage aluminum electrolytic capacitors mainly depends on the quality of the anode foil. The quality of the anode foil depends on the stability of the working medium oxide film on the surface of the aluminum foil. [0003] In the existing traditional anode foil formation process for high-voltage aluminum electrolytic capacitors, in order to obtain a stable oxide film working medium, a mixed acid containing boric acid or boric acid is used for formation. Although the quality of the formed porous oxide film is stable, it is resistant to hydration (anti- Deterioration) is not ideal, another electrical performance index parameter leakage cu...

AI Technical Summary

Problems solved by technology

[0003] In the existing traditional anode foil formation process for high-voltage aluminum electrolytic capacitors, in order to obtain a stable oxide film working medium, a mixed acid containing boric acid or boric acid is used for formation. Although the quality of the formed porous oxide film is stable, it is resistant to hydration (anti- Deterioration) is not ideal, another electrical performance index parameter leakage current of the oxide film is good or bad, the high-voltage bolted aluminum electrolytic capacitor has particularly high quality requirements for the anode foil, and the quality of the oxide film produced by the traditional boric acid formation process is not ideal