Vanadium redox flow battery is a secondary battery with vanadium ion solution as positive and negative active materials. The positive and negative compartments of the vanadium battery are separated by a diaphragm, and the electrodes are composed of electrode active materials and current collectors; the positive electrolyte is composed of V(V) and V(IV) ionic sulfuric acid solutions, and the negative electrolyte is composed of V(III) and V( II) Composition of ionic sulfuric acid solution. After the battery is charged, the positive electrode material is V(V) ion solution, and the negative electrode is V(II) ion solution; after discharge, the positive electrode and the negative electrode are V(IV) and V(III) ion solution, respectively, and the interior of the battery conducts electricity through H+.