Ionic liquid electrolyte and method for preparing bright aluminum coating by use of ionic liquid electrolyte

Abstract

The invention provides an ionic liquid electrolyte and a method for preparing a bright aluminum coating by use of the ionic liquid electrolyte, and mainly aims at solving the problems of inappropriate viscosity, electrical conductivity and the like of the existing ionic liquid for preparing the bright aluminum coating. The electrolyte is composed of an ionic liquid, an anhydrous aluminum halide salt and auxiliaries, wherein the molar ratio of the ionic liquid to the anhydrous aluminum halide salt is 1: (1.5-2.0), and the molar ratio of the ionic liquid to the auxiliaries is 1: (0.1-4). The method for preparing the bright aluminum coating by use of the ionic liquid electrolyte comprises the following steps: firstly, putting an electrolyzer in a nitrogen or argon environment atmosphere without water or oxygen under normal pressure, adding the ionic liquid electrolyte, and performing electrolysis under the conditions of an electrolysis temperature of 10-30 DEG C, the current density of 1-10A / dm<2> and regulated electrolyzer pressure, thereby obtaining the bright luster aluminum coating. After the auxiliaries are added to the ionic liquid electrolyte for preparing the bright aluminum coating, the electrolyzer pressure is reduced and the viscosity and the electrical conductivity of the ionic liquid are improved, and therefore, the electrolytic deposited bright aluminum coating is obtained.

Description

technical field [0001] The invention relates to an ionic liquid electrolyte and a method for preparing a bright aluminum coating by using the electrolyte, belonging to the field of electroplating. Background technique [0002] Since aluminum is a cathode metal whose electrode potential is more negative than that of hydrogen, aluminum electrolysis in water system cannot be realized, and high-temperature molten salt electrolysis aluminum technology has high temperature and cannot directly obtain solid aluminum. The emergence and application of low-temperature electrolytic aluminum technology provides the possibility to directly obtain solid aluminum products by electrolysis. Electrolytic aluminum in low temperature non-aqueous system mainly includes organic solvent system, molten salt system and ionic liquid system. In comparison, the advantages of the ionic liquid system are that it has a wide temperature range, high electrical conductivity and a wide electrochemical window,...

AI Technical Summary

Problems solved by technology

Although properly increasing the electrodeposition temperature can reduce the viscosity of the ionic liquid and accelerate the ion diffusion rate, the accelerated gradient of the chemical reaction on the electrode surface is greater than the accelerated gradient of the ion migration, thereby aggravating the concentration polarization. thermal instability, this method is not desirable

Chinese patent CN101760758A, while electrodepositing aluminum, makes the electrolytic cell centrifugally rotate to generate a supergravity field, strengthens the convection and diffusion process, can refine the crystal grains, and avoid the production of dendrite aluminum, but the production equipment has high requirements and belongs to special conditions. The field of metal electrodeposition

Chinese patent CN103849911A adds 0.5-15g / L pyridine derivatives to generate adsorption on the electrode surface to increase the chemical polarization of the electrode surface, thereby obtaining a bright aluminum coating, but at the same time it also increases the cell pressure and reduces the current density.

[0003] In addition, ethanol, acetone and other solvents are often used in the final finishing and cleaning of the obtained electroplating products or electroplating equipment, but these solutions are not only flammable and explosive, but also bond with the active aluminum ions in the electrolyte, resulting in product cleaning. It is not clean, and the viscosity of the cleaning solution increases, so that the viscosity cannot be used. A solvent or cleaning agent that does not interact with the anions and cations of the chloroaluminate system is needed

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