Preparation method of electrolyte used for all vanadium redox flow batteries

Abstract

The invention discloses a preparation method of electrolyte used for all vanadium redox flow batteries, which is characterized in that one or more reducing agents are added to vanadium pentoxide and sulfuric acid, and the mixture fully reacts at the temperature of 50-100 DEG C for 0.5-10h to prepare the electrolyte with vanadium ion concentration between 1mol / L and 6mol / L. In the method, isobutyl alcohol, butyraldehyde, dicarboxyl, 1, 3-propanediol, 2-butylene or the mixture thereof is used as a reducing agent; the preparation process is simple, the operation is easy and the cost is low, in particular, the high-purity vanadium battery electrolyte with vanadium ion concentration between 1mol / L and 6mol / L is prepared; besides, the above process only produces carbon dioxide and water but no other wastes, thus being environment-friendly; the reducing agents used in the prior art are generally inorganic matters such as sulphur powder, thus easily producing huge amounts of pollutants, but in the method, organic matters are used as reducing agents and only produce carbon dioxide and water in the whole process, thus reducing the pollution in the process of preparing the high-purity vanadium battery electrolyte.

Description

technical field [0001] The invention relates to a method for preparing an electrolyte for a vanadium battery, in particular to a method for preparing an electrolyte for an all-vanadium ion redox flow battery. Background technique [0002] The all-vanadium ion redox flow battery is called vanadium battery for short. The vanadium ion solution of different valence states is used as the positive and negative active materials respectively in the vanadium battery. The electrolyte is driven by an external pump to circulate the electrolyte in the liquid storage tank and the battery stack. The negative electrode electrolyte undergoes reduction and oxidation reactions on the electrodes on both sides of the ion exchange membrane in the stack body, thereby completing the charging and discharging process. [0003] Its reaction formula is as follows: [0004] Negative reaction: V 2+ -e - =V 3 +E 0 =-0.26V [0005] Positive reaction: VO 2 + +2H + +e - =VO 2+ +H 2 O E 0 = 1.00V...

AI Technical Summary

Problems solved by technology

None of the above methods can greatly improve the purity of the electrolyte, and it requires a large amount of energy in the production process and produces a large amount of sulfur-containing chemical pollutants, which is not conducive to large-scale production. It can be seen that the prior art needs further development

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