Viscosity Properties Of High-concentrated Ternary Electrolyte In The Vanadium Redox Flow Battery

In recent years,the application of new energy sources receives increasingly attention in our country.However,new energy sources are facing many challenges in practical application and energy storage is a problem,above all,to solve.Hence,vanadium battery technology has emerged as the times require.As a flow battery,vanadium battery stores its energy in the vanadium electrolyte.The energy storage performance of the entire vanadium battery is deeply affected by the electrolyte.Therefore,it is very necessary to study the vanadium battery electrolyte.Currently,vanadium electrolyte performance is improved by adding different additives to the vanadium battery electrolyte.The addition of additives will affect the viscosity of the electrolyte,which will directly influence the battery performance.Therefore,two different semi-empirical viscosity predict equations have been designed to predict the effect of additives?methanesulfonic acid,polyacrylic acid?on the vanadium electrolyte viscosity under different conditions.The research work of this paper is mainly as follows:The viscosity of an aqueous solution of methanesulfonic acid with a low concentration from 10°C to 45°C was measured.According to the Jone-Dole empirical equation,the viscosity B-coefficient and limiting apparent molar volume of methanesulfonic acid at different temperatures were calculated.On the basic of the transition-state treatment,the free activation energy of methanesulfonic acid was obtained.According to the above data,a ternary electrolyte solution?VOSO₄+CH₃SO₃H+H₂O?viscosity prediction equation was constructed on the basis of the Eyring equation.The viscosity of ternary electrolyte solution was measured at different temperatures,ionic strength and ionic strength fractions.By comparing the experimental results with the predicted results,it turns out that the predicted results are in quite good agreement with the corresponding experimental results with the average relative deviation of 0.22%.Polyacrylic acid was selected as the vanadium electrolyte additive.Based on the prediction of viscosity for the binary polyacrylic acid aqueous solution and vanadyl sulfate aqueous solution,two different viscosity semi-empirical predict equations for ternary electrolyte solution?VOSO₄+PAA+H₂O?were constructed according to the Eyring equation.The viscosity of the ternary electrolyte solution?VOSO₄+PAA+H₂O?was measured under different conditions.By comparing the relative deviations and other parameters,the best predict equation was selected.The average relative deviation between the predicted values and the experimental values obtained by the equation is 0.32%.