Investigation of electrolytes of the vanadium redox flow battery (IV): Measurement and prediction of viscosity of aqueous VOSO4 solution at 283.15 to 323.15 K

Abstract

Viscosity and density for aqueous VOSO4 solution have been measured in the concentration range of (0.05 to 0.3) mol·kg−1 at different temperatures from (283.15 to 323.15) K. On the basis of the measurements, the activation energy of viscous flow has been calculated by Arrhenius equation. A predicting function for the viscosity of aqueous VOSO4 has been proposed based on the viscosity coefficients A and B determined from Jones-Dole equation. In addition, the VO2+-water interaction and its effect on the structure of solvent according to the B-coefficient of VO2+ in dependence of temperature have been discussed. Using the B-coefficients, furthermore, the activation parameters for viscous flow of the solution, Δμ1≠0, Δμ2≠0, and other thermodynamics parameters ΔS2≠0, ΔH2≠0 and ΔCp2≠0 were evaluated. Finally, another empirical model of the viscosity has been investigated on the basis of the Eyring equation with the AAPD of 1.81%, and the maximum relative deviation is 2.77% below 313.15K, but up to 7.01% above 323.15K. Both predicting equations for the viscosities of aqueous VOSO4 are both in good agreement with the experimental results.