%0 Journal Article
%K Diffusion
%K Flow battery
%K Vanadium
%K Crossover
%K Electro-osmosis
%K Hydrogen-Bromine
%K Migration
%A Robert M Darling
%A Adam Z Weber
%A Michael C Tucker
%A Michael L Perry
%B Journal of the Electrochemical Society
%D 2015
%N 1
%P A5014 - A5022
%R 10.1149/2.0031601jes
%T The Influence of Electric Field on Crossover in Redox-Flow Batteries
%V 163
%8 01/2016
%X <p>Transport of active species through the ion-exchange membrane separating the electrodes in a redox-flow battery is an important source of inefficiency. Migration and electro-osmosis have significant impacts on the crossover of reactive anions, cations, and neutral species. In this paper, these phenomena are theoretically and experimentally explored for commercial cation-exchange membranes. The theoretical analysis indicates that plotting the cumulative Coulombic mismatch between charge and discharge as a function of time can be used to assess crossover rates. The relative importance of migration and electro-osmosis over diffusion is quantified and shown to increase with increasing current density and membrane thickness because the contributions of migration and electro-osmosis to ionic flux are independent of membrane thickness and proportional to current density, while diffusion is inversely proportional to membrane thickness and independent of current density.</p>