Method of manufacturing porous aluminum foil for lithium ion capacitor current collector

Abstract

The invention relates to the field of capacitor manufacturing, and discloses a method for preparing a porous aluminum foil for a current collector of a lithium ion capacitor. The aluminum foil is used as a raw material, and a direct current electrolytic oxidation method is adopted. The steps are as follows: use inert graphite as a cathode, and use the aluminum foil as an anode pair The aluminum foil is subjected to one-step electrolysis to produce pores and expand pores; the aluminum foil after the above treatment is sequentially cleaned, post-treated and electrolyzed, and washed twice to obtain a porous aluminum foil. The method of the invention has simple process and low cost, and is suitable for industrial production.

Description

technical field [0001] The invention relates to the field of capacitor manufacturing, in particular to a method for preparing a porous aluminum foil for a lithium ion capacitor current collector. Background technique [0002] Lithium-ion capacitors have the advantages of large capacity, high voltage, high power, and long service life. They are a promising emerging green energy storage device. Lithium-intercalable materials similar to lithium-ion batteries. [0003] Since the lithium ion capacitor negative electrode material needs to pre-intercalate lithium, the capacitor positive electrode and negative electrode current collector must have pores that allow lithium ions to pass through. [0004] At present, the widely used aluminum foil of aluminum electrolytic capacitors has holes, but this aluminum foil is not suitable for lithium ion capacitor current collectors. The reasons are: 1) Although the anode aluminum foil of aluminum electrolytic capacitors has tunnel-type thr...

AI Technical Summary

Problems solved by technology

[0004] At present, the widely used aluminum foil of aluminum electrolytic capacitors has holes, but this aluminum foil is not suitable for lithium ion capacitor current collectors. The reasons are: 1) Although the anode aluminum foil of aluminum electrolytic capacitors has tunnel-type through holes, the aperture is very small, only a few A micron, it is difficult for lithium ions to pass through; due to the need for high voltage resistance of the anode aluminum foil, a dense layer of Al is formed on the surface 2 o 3 Oxide film, the oxide film has a very high resistance and cannot be used for battery or capacitor current collectors

2) There are many micropores on the surface of the cathode aluminum foil of an aluminum electrolytic capacitor, which is in the shape of a sponge. Its structural strength is small, and there are almost no through holes, and it cannot be used as a battery or capacitor current collector.

In this method, the raw material aluminum halide is expensive, the process control is complicated, and the industrial production is difficult.