Modification Of The Vanadium Redox Flow Battery Electrode Materials And Design Of The Stack Structure

The vanadium redox flow battery is proposed by M Kazacos of the New South WalesUniversity in1984. The battery which owns long service life, high reliability, simpleoperation generates current by using different valence vanadium ion’s conversion, Theelecteode that provides the places for the reaction does not react itself. Therefore, the redoxflow battery caused a widerspread attention in researchers. The paper focuses on the study ofthe vanadium battery electrode materials, electrolyte of vanadium battery and vanadiumbattery stack design. The PAN-based carbon felt which prepared under2000℃modified byacid treatment and metal ions integrated, then the modified carbon felt will be tested by cyclicvoltammetry, polarization curves and SEM. The preparation method of electrolyte includeschemical synthesis method and electrolysis method. In this paper, The electrolyte ofvanadium battery is prepared by electrolysis method, then, the stability of electrolyte whichadds the potassium citric,ammonium sulphate, cobalt nitrate and four chlorination tin will betested after a period of time.After350℃,450℃, and550℃heat-treated carbon felt electrode electrochemicalperformance than untreated before get a good improvement. Among them, the carbon feltelectrode with heat treatment at550℃have the best performance. The oxidation peaks aresignificantly with higher peak currents and good reversibility. It can be used as the material ofthe vanadium redox battery.Through the infrared analysis, it is found that the content of the–OH and C=O groups isincreased after the acid and heat comprehensive treatment while the content of the alcohol andether is reduced. It can be also said that the electrochemical performance of the carbon felt isimproved becaused of increasing the content of the–COOH in the carbon felt.After the nickel nitrate solution at different concentrations for24h carbon felt electrodeelectrochemical performance than untreated before get a good improvement. Among them, thecarbon felt electrode with the concentration of2mol/L treatment have the best performance.The oxidation peaks are significantly with higher peak currents and good reversibility. It canbe used as the material of the vanadium redox battery.The vanadium battery electrolyte can get the high concentrations by the method ofelectrolysis. It was found that the stability of the electrolyte is not improved when adds thepotassium citric and cobalt nitrate. The stability of the electrolyte has been significantlyimproved when adding the four chlorination tin after a period of time.The design of the vanadium battery stack consists of two half-cells, which one is thegenuine battery, and the other is the negative half-cell. The components of two half-cells are symmetrical to each other, but it is also isolated from each other to avoid cross-contamination.The positive half-cell is composed of the end plate, electrode backing and baffles. Theelectrolyte solution flows into both sides of the end plate and the electrode plate,then flowsout of the component of the negative half-cell, In this way,it was one cycle. The electrolyteflow pattern in the negative half-cell is the same way.