Among all kinds of electrode materials of vanadium redox flow battery, graphite felt is the best comprehensive performance of electrode material, but it still needs to be activated to enhance its performance.
As one of the most important parts of vanadium battery, electrode and its related characteristics, including cost and processing technology, have become the key aspects of the research and development of vanadium battery system. Choosing appropriate electrode materials can improve the electrochemical activity of the electrode, and ultimately improve the energy efficiency of vanadium battery. Vanadium battery electrode materials are carbon, such as graphite, carbon cloth, carbon felt, etc., there are metals, such as Pb, Ti, etc., there are conductive polymer or polymer mixture composite electrode.
But from the point of reducing the cost of the electrode and reducing the quality of the battery, the results of the study of various carbon materials show that the effect of PAN based graphite felt is best.
However, the performance of PAN based graphite felt can not meet the needs of vanadium battery, and it needs to be processed on the graphite felt surface to improve its performance.
Although the comprehensive performance of graphite felt is superior, the electrochemical activity of the electrode can not meet the requirement of vanadium battery, so it needs to be processed to improve its electrochemical performance. Common graphite felt treatment methods are metal ion modification,acid treatment, heat treatment, ammoniation treatment, electrochemical treatment and comprehensive treatment.
After a variety of methods to deal with, will make graphite felt's specific surface area increased, the reaction area increased. At the same time, after treatment increased the number of carbon fiber surface active functional groups such as C=O and C-O functional groups such as the removal of the impurities on the surface of carbon fiber such as the production of metal ions was introduced into the process, reduce the resistance of graphite felt, so as to improve the electrochemical activity of graphite felt.