1. The electrolyte of vanadium battery is all vanadium. First, an electrolyte is prepared by directly dissolving VOSO4 in H2SO4. However, due to the high price of VOSO4, people began to turn their attention to V2O5, NH4VO3 and other vanadium compounds. At present, there are two main methods to prepare electrolyte: mixed heating preparation method and electrolysis method. Among them, the mixed heating method is suitable for preparing 1mol/L electrolyte, and the electrolytic method can prepare 3~5mol/L electrolyte.

2. Vanadium battery separator

The diaphragm of vanadium battery must inhibit the cross-mixing of vanadium ions with different valence States in the positive and negative electrolyte, and cannot prevent hydrogen ions from transferring charges through the diaphragm. Therefore, it is necessary to choose an ion exchange membrane with good conductivity and selective permeability, and it is best to choose a cation exchange membrane that allows hydrogen ions to pass through. Generally, the battery separator is mainly cation exchange membrane, and Nafion membrane (DuPont) is also used, but the latter is more expensive. It is one of the ways to improve the efficiency of vanadium battery by treating cation exchange membrane to improve its hydrophilicity, selective permeability and prolong its service life. Perfluorosulfonic acid ion exchange membrane was first developed by DuPont, with Nafion as the trademark, and it is the best ion exchange membrane at present.

3. Vanadium battery electrode materials

In order to realize large-capacity energy storage, all vanadium redox flow batteries must be connected in series or in parallel, which requires all electrodes except the terminal electrodes to be bipolar electrodes. Because of the strong oxidation of V02+ and the strong acidity of sulfuric acid, the electrode material of vanadium battery must have the characteristics of strong oxidation resistance and strong acidity, low resistance, good conductivity, high mechanical strength and good electrochemical activity. Electrode materials of vanadium batteries are mainly divided into three categories: metals, such as Pb and Ti; Carbon, such as graphite, carbon fiber cloth, carbon felt, etc. Composite materials, such as conductive polymers, polymer composites, etc.