Method for preparing all-vanadium ionic liquid flow battery electrolyte and prepared electrolyte

Abstract

The invention relates to a method for preparing an all-vanadium ionic liquid flow battery electrolyte and the prepared electrolyte, which belong to the field of battery electrolytes. The technical problem solved by the method is to provide a method which cannot produce crystals when the all-vanadium concentration of an electrolyte reaches 2mol / L in a battery and is used for preparing the all-vanadium ionic liquid flow battery electrolyte. The method for preparing the all-vanadium ionic liquid flow battery electrolyte comprises the steps of: taking a H2SO4 solution of VOSO4 as a cathode, taking a H2SO4 solution of Na2SO4 as an anode, and electrolyzing to obtain a trivalent vanadium electrolyte. The preparation of the electrolyte by the method cannot affect the service life of vanadium batteries; the method can avoid the waste of vanadium liquids of anodes, improve the utilization rate of vanadium, and reduce the production cost for the electrolyte; the electrolyte prepared by the method does not need to add any additive, and does not affect the performance of the vanadium batteries; and the method is suitable for the mass production of the electrolyte, and has low equipment requirement and simple operation steps.

Description

technical field [0001] The invention relates to a method for preparing an electrolyte for an all-vanadium ion flow battery and the prepared electrolyte, belonging to the field of battery electrolytes. Background technique [0002] All-vanadium ion flow battery is a new type of large-scale electrochemical energy storage device, which has the characteristics of high capacity, wide application field (environment) and long cycle life. It is different from batteries that usually use solid material electrodes or gas electrodes. Its active substance is a flowing electrolyte solution. Batteries will usher in a period of rapid development. At present, the electrolyte solution of the all-vanadium ion flow battery is mainly prepared by electrolytic vanadyl sulfate. The specific preparation method is: pour an equal amount of vanadyl sulfate sulfuric acid solution into the positive electrode and the negative electrode of the battery respectively, charge it, and pour the positive electro...

AI Technical Summary

Problems solved by technology

This method needs to replace the positive electrode solution once, resulting in waste of vanadium raw materials, and requires secondary charging, complicated battery assembly and procedures, and shortens the life of the vanadium battery, which is limited by the charging conditions of the vanadium battery. Prolonged preparation time affects production efficiency

In addition, the concentration of the electrolyte prepared by this method is not high, generally about 1mol / L. When the concentration of the electrolyte reaches 1.5mol / L, crystallization will occur after 50 cycles of 1A constant current charge and discharge in a small battery at room temperature , at the same time, the cycle of the battery is attenuated, the charging and discharging time is gradually shortened, and the charging and discharging platform is not obvious