Electrolyte corrosion inhibitor, aluminum-air battery electrolyte and preparation method thereof

Abstract

The invention relates to an electrolyte corrosion inhibitor, an aluminum-air battery electrolyte and a preparation method of the aluminum-air battery electrolyte. The electrolyte corrosion inhibitor mainly comprises an inorganic phase type corrosion inhibitor and an organic adsorption type corrosion inhibitor, wherein the inorganic phase type corrosion inhibitor is selected from at least one of zinc acetate, manganate and scandium nitrate; the organic adsorption type corrosion inhibitor is selected from at least one of benzotriazole, a natural amino acid and a cationic surfactant; and the molar ratio of the inorganic phase type corrosion inhibitor and the organic adsorption type corrosion inhibitor is (1-5,000) to (1-1,000). The electrolyte corrosion inhibitor is prepared on the basis of the property of an electrolyte solution, has the advantages of the phase type corrosion inhibitor and the adsorption type corrosion inhibitor, and is a multifunctional additive with good overall performance.

Description

technical field [0001] The invention relates to the field of aluminum-air batteries, in particular to an electrolyte corrosion inhibitor, an aluminum-air battery electrolyte and a preparation method thereof. Background technique [0002] Since the concept of green and clean energy was proposed, metal-air batteries have been a subject of much concern. Aluminum-air batteries (Al-O 2 battery) is a battery with aluminum as the negative electrode. Among them, aluminum is rich in geological reserves (the third element in the earth's crust), low in cost, relatively easy to process, and has a high theoretical mass specific energy (8.1kWh / kg, second only to lithium), and the reaction product hydroxide Aluminum (Al(OH) 3 ) can also be recycled and reused. Because of these characteristics, aluminum-air batteries have been favored by countries all over the world. The electrolyte of aluminum-air batteries usually uses sodium hydroxide or potassium hydroxide as the electrolyte, and ne...

AI Technical Summary

Problems solved by technology

The electrolyte of aluminum-air batteries usually uses sodium hydroxide or potassium hydroxide as the electrolyte, and neutral salt solution is also used, but due to the Al on the surface of the aluminum 2 o 3 The passivation layer is very dense and difficult to be destroyed, and the solubility of the reaction product aluminum hydroxide is relatively low, so the power density and energy density of the neutral battery system are relatively low, which is difficult to meet the requirements of high-power applications

Some researchers also use sulfuric acid as the electrolyte, and its theoretical battery electromotive force is higher than that of alkaline electrolyte batteries. However, aluminum is more easily passivated in concentrated sulfuric acid solution, and concentrated sulfuric acid solution is easy to corrode other materials in the battery system, so it is usually not used.

[0003] In the process of large-scale development of alkaline aluminum-air batteries, the anode system mainly faces the following two problems: First, due to the existence of an oxide film on the aluminum surface and the deposition of the reaction product aluminum hydroxide on the anode surface, the dissolution of aluminum is inhibited, and the electrode The potential is positively shifted; the second is that aluminum is prone to severe hydrogen evolution self-corrosion under the open circuit voltage and during the discharge process, which greatly reduces the discharge efficiency of the battery

Although most corrosion inhibitors can reduce the hydrogen evolution self-corrosion of aluminum anodes, their functions are often too single, and there are great defects. For example, although adsorption-type corrosion inhibitors inhibit corrosion, they also greatly reduce the activity of aluminum anodes. With the dissolution of the aluminum matrix, the deposition layer is gradually peeled off, and the corrosion inhibition effect gradually decreases or even disappears. Therefore, it is difficult to meet the application requirements only by adding a single type of corrosion inhibitor.

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