Method for producing blowing up electrolyte and high specific surface area aluminum electrolytic capacitor electrode foil

Abstract

The invention relates to a pitting electrolyte and a production method of an electrode foil with high specific surface area for an aluminum electrolytic capacitor. The pitting electrolyte mainly contains aluminum chloride and sulfuric acid solution. The production method comprises a first pre-treatment step, a second anode oxidization step, a third acid pickling step, a fourth corrosion pitting step, a fifth hole expansion step and a sixth post-treatment step. The invention has simple process, convenient operation and less environment pollution. The electrode foil for the aluminum electrolytic capacitor produced by the invention has optimal normal distributions in hole diameter distribution, hole area and minimal hole pitch distribution, thus achieving uniform pitting capable of controlling the corrosion start point and greatly improving the specific capacity of the electrode foil for the aluminum electrolytic capacitor. Accordingly, the prepared aluminum electrolytic capacitor has a specific surface area of 10% to 15% and a specific capacity up to 0.70 to 0.75 muF / cm<2>.

Description

technical field [0001] The invention relates to the technical field of producing electrode foils for aluminum electrolytic capacitors, and relates to a method for producing porous electrolytes and high specific surface area aluminum electrolytic capacitor electrode foils. Background technique [0002] In the known aluminum foil etching process for aluminum electrolytic capacitors, three process steps are usually taken: [0003] The first step of pretreatment: Alkaline or pickling of aluminum foil for aluminum electrolytic capacitors to be corroded. Alkali washing mainly removes oil stains, defects and oxide films on the foil surface; The surface forms the starting point of the hole. [0004] The second step corrodes pores: on the basis of the aforementioned step 1, anions containing strong pitting effects (such as chloride ions) are used to corrode pores on the surface of the aluminum foil, so that many initial pores are randomly distributed on the surface of the aluminum f...

AI Technical Summary

Problems solved by technology

[0007] Observing the corroded holes of the aluminum foil for aluminum electrolytic capacitors produced by the above-mentioned prior art through scanning electron microscopy has different shapes, such as round, square or irregular holes. to measure, to obtain figure 1 , attached figure 2 And attached image 3 From the above statistical distribution diagram, it can be seen that the data distribution of the relevant parameters of the electrode foil for aluminum electrolytic capacitors produced by the prior art is peak-shaped, which belongs to the type of poor data distribution, and also shows that the hole distribution parameters are not uniform.

Moreover, the electrode foil for aluminum electrolytic capacitors produced by the prior art is only up to 0.60 μF / cm according to the Japanese JCC standard. 2 to 0.65μF / cm 2 Around , the data dispersion rate is high

[0008] The above-mentioned prior art also has the following defects: the surface of the aluminum foil after being cleaned by alkali or acid solution becomes very active, and the direct electric corrosion easily causes the surface of the aluminum foil to be fully dissolved, the corrosion layer peels off, the foil becomes thinner rapidly, the mechanical strength decreases, and the expansion Low face rate

Images