Vanadium battery as the current strong momentum of development of green energy storage battery, has broad prospects for development in large-scale energy storage. However, in the process of vanadium battery research, the research of electrode materials is one of the key constraints. The electrode material must have the characteristics of stability, performance in strong acid medium and low resistivity, good conductivity, high mechanical strength, high electrochemical activity, and electrode materials at present is not up to the above requirements, can not meet the actual needs of the long-term work of vanadium battery.
Carbon materials due to its good conductivity and corrosion resistance, many researchers of various carbon materials by charge discharge experiments in vanadium electrolyte, found that graphite rods, graphite plate as cathode in the etching phenomenon, glassy carbon material surface electrochemical irreversibility, polyacrylonitrile based graphite felt the best performance. Through the experiment, it is very important to the polyacrylonitrile based graphite felt electrode surface modification.
Polyacrylonitrile based carbon fiber with high strength, high modulus, high temperature resistance, corrosion resistance, fatigue resistance, low coefficient of a series of excellent creep resistance, electrical conductivity, heat transfer and thermal expansion.
At present, the domestic market is not on the sale of carbon felt carbon felt, because the main use is as a thermal insulation material. The raw materials of PAN based carbon fiber carbon fiber is non graphitic structure, carbon content more than 90%, the carbon fiber in 10m.Cm resistivity magnitude, the resistivity is relatively large, and the carbon fiber surface energy is low, and the water wettability, contact angle, surface is hydrophobic, and without any the carbon fiber is not suitable for vanadium battery electrode.
Processing time should not be more than 2 hours, and the electrochemical activity of graphite felt will decrease with the increase of treatment time in the process of acid treatment of graphite felt.