Novel Metal Oxide Electrode Materials for Vanadium Redox Flow Battery Application

Abstract

Solar cell and wind power plant have been widely used in the earth as a renewable energy source. However, those alternative energy sources have one critical problem which is the energy output cannot provide stable electricity power for common use. Since these issues, scientists have developed energy storage technique in the past several decades, such as pumped hydropower, compressed air energy storage, lithium-ion batteries, and lead-acid batteries. Recently, vanadium redox flow battery (VRFBs) is the energy storage system which can provide larger energy capacity and longer lifetime. Basically, VRFBs system can be divided by three main parts which include an electrode, membrane, and electrolyte. Nowadays, the big challenge of the carbon-based electrode has lower energy conversion efficiency. Therefore, our studies are more focusing on the electrode material development. Carbon material modification by oxygen-containing functional group or metal oxide loading has been developed in the past years. Especially, tungsten oxide nanowire shows good energy efficiency 67.7 % in higher current density 160 mA cm -2 and still remain 79 % in the energy efficiency of 80 mA cm -2 after 50 cycles test.