Vanadium Redox Flow Battery

All vanadium redox flow battery (AVRFB) is a new-style secondary battery that has many characteristics. As a single-metal system, AVRFB overcomes the problem of cross-contamination of the two half-cell electrolytes that traditional lead Acid battery and Fe/Cr battery has encountered, so it is showing promising results for various stationary applications such as remote area power systems, load leveling at power plants and emergency back-up applications. The advantage that can be both electrically recharge and mechanically refueled has attracted much attention on its application in electric vehicles. However, there are still some questions to be solved, not only on the theory but also on the practical application. They are preparing high purity vanadium electrolyte, choosing suitable electrode and membrane, improving the catalysis performance of the electrode through some activate methods, and controlling the proper operation parameter of the charge and discharge. Investigation of above-mentioned themes is very important for improving the energy density and the efficiency of AVRFB and Accelerating its commercialization in China. In this paper, high concentration vanadium electrolyte has been prepared by the dissolve and electrolysis. Their reversibility has been evaluated by the cyclic voltammetry. The result showed that the four characteristic peaks of V(II)/V(IV) and V(IV)/V(V) redox couples appears on the all voltammograms; the higher the concentration of the electrolytic liquid and the scan rate are, the bigger the peak current is; but the increase of speed of scanning make the peak potential separation wider. After the thermal treatment/acid Treatment, the porous PAN based graphite felt electrode has been bonded to Carbon-Polymer Conducting Plastic. So Composite Electrode has been obtained. The influence of modification is judged by the cell resistance. It is proved that the optimum condition of thermal treatment and acid treatment are 400??, 30h and 98% sulphuric acid solution, 5h. And combined with the electrode reaction, the mechanism of Catalysis is analyzed. In experiment, the import nafion 117-membrane is selected as the battery separator. In view of the several factors, the optimization design is made in all packages of battery. A lab-level vanadium battery has been constructed. In terms of results of charge/diacharge...