Method for erosion of high pressure high specific volume anode foil

Abstract

The invention relates to a corrosion method of anode foil with high pressure and high specific volume. Firstly, preliminary treatment is performed to aluminum foil; secondly, primary direct current electrolytic corrosion is performed in the mixed liquor with the concentration of 0.5 to 5 wt percent of sulphuric acid and 1 to 10 wt percent of sulphuric acid; thirdly, secondary direct current electrolytic corrosion is performed in the mixed liquor with the concentration of 5 to 15 wt percent of sulphuric acid, 0.01 to 0.1 wt percent of phosphoric acid and 0.01 to 0.1 wt percent of polyethylene glycol (The molecular weight is 10000); thirdly, the tertiary direct current electrolytic corrosion is performed in the mixed liquor with the concentration of 5 to 15 wt percent of chlorhydric acid, 0.01 to 0.1 wt percent of phosphoric acid and 0.01 to 0.1 wt percent of polyethylene glycol; finally, the immersion is performed in the water solution with the concentration of 0.5 to 5 wt percent of nitric acid. The adoption of the corrosion method of the invention not only solves the corrosion problem of the high voltage anode foil, but also improve the surface expand rate of the aluminum foil, the specific volume of the aluminum foil is greatly improved, and the high voltage anode foil has better mechanical strength on the premise of obtaining high specific volume.

Description

technical field [0001] The invention relates to a processing method for an electrode foil for an aluminum electrolytic capacitor, in particular to a method for corroding an anode foil for a high-voltage aluminum electrolytic capacitor; it belongs to the field of manufacturing aluminum electrolytic capacitors. Background technique [0002] Anode foil for aluminum electrolytic capacitors, in order to expand its effective surface area, the original aluminum foil is chemically or electrochemically etched to form high-density uniformly distributed corrosion pits with a certain depth on the surface to increase the effective surface area of ​​the aluminum foil. There are many reports on the research on increasing the corrosion area expansion rate. In the past, the corrosion process was mainly due to the small corrosion pore size and uneven distribution. When the oxide film was formed, the area expansion effect was reduced due to the thick oxide film; [0003] Recent Chinese patent ...

AI Technical Summary

Problems solved by technology

[0004] The present invention provides a high-voltage and high-volume anode foil corrosion method for the defects that the existing anode foil corrosion method can only corrode low-voltage anode foil but cannot corrode high-voltage anode foil; the method not only solves the problem of The corrosion problem of high-voltage (520V, 610V) anode foil is solved, and the anode foil has good mechanical strength under the premise of obtaining high specific volume