Buckley, DN;Oboroceanu, D;Quill, N;Lenihan, C;Eidhin, DN;Albu, SP;Lynch, RP

2018

October

Journal Of The Electrochemical Society

Measurement and Computer Simulation of Catholyte Stability in Vanadium Flow Batteries (VFBs)

Published

6 ()

GRAPHITE FELT ELECTRODE REDOX CELL ELECTROLYTE POSITIVE HALF-CELL IV-V-V CARBON ELECTRODES ENERGY-STORAGE TRANSFER KINETICS FUEL-CELL PERFORMANCE VO2+/VO2+

165

3263

3274

Based on careful experimental measurements, a model for the stability of vanadium flow battery (VFB) catholytes was developed which quantifies their precipitation behavior as a function of temperature and composition. The model enables simulation of the induction time for precipitation at a temperature T for any catholyte with concentrations of sulfate and V-v within the range of applicability. The results of such simulations are in good agreement with experiment. The model can predict catholyte stability using any of three alternative metrics: the induction time tau, the relative stability parameter rho and the stability temperature T-W. The induction time is a good measure of overall stability; the relative stability parameter compares the stability of any catholyte to a standard in a temperature-independent manner; and the stability temperature estimates the upper temperature limit at which a catholyte is stable for practical purposes. Equations are derived for these parameters and the behavior of each parameter is simulated and plotted under a variety of conditions. Likewise, the effect of state of charge is simulated and plotted. The plots and the associated equations provide detailed stability data that can be useful in the design of practical flow batteries. (C) The Author(s) 2018. Published by ECS.

PENNINGTON

0013-4651

10.1149/2.0091814jes