Research On The Key Materials For All Vanadium Redox Flow Battery

Vanadium redox flow battery (VRB) is a new electrochemical energy storage device. Its characteristic includes long battery life, high reliability, high efficiency, rapid charging and discharging. The battery capacity depends on the amount of electrolyte and vanadium ion concentration. It has great development prospect in photovoltaic power, wind power, load shifting areas.Ion exchange membrane is one of VRB key functional materials, its performance directly affects the output power and performance of vanadium redox flow battery. In this paper Nafion117/SiO2 composite membrane was prepared by doping nano SiO2 through sol-gel method, so the character of battery can be improved by reducing the permeability of Vanidium in the membrane. The permeability of V4+ in Nafion117/SiO2 composite membrane prepared under different process conditions(nMeOH/nTEOS, hydrolysis time, natural drying time after hydrolysis). The permeability reduced by 52 times than that in Nafion117 membrane. SEM tests proved that SiO2 grain grew bigger in the composite membrane during the natural drying time. Single cell test and AC impedance results both proved that the character of Nafion117 / SiO2 composite membrane is better than that of Nafion117.Electrolyte is the active substance in VRB electrochemical reactions. Its performance has a direct impact on battery performance. This paper used ammonium metavanadate and ammonium bicarbonate as the electrolyte material, we got black powder by vacuum heat treatment. XRD showed that the product was V2O3. The electrolyte with trivalent and tetravalent vanadium ion which mole ratio is 1:1 can be made by adding a certain amount of V2O5 into V2O3 sulfuric acid solution. The thesis also researched the diffusion behavior of different valence state of vanadium ions in Nafion117 membrane.Through researching in the membrane and electrolyte of Vanadium battery,the article determined the best process to make Nafion117/SiO2 membrane under laboratory condition,also provided an inexpensive way to make the electrolyte, which saved the cost of production, but also shorten the preparation time, and product quality was also very easy to control...