Analytical current-voltage formulas in electrodes and concentration differences for VRFB

Abstract

The Vanadium redox flow battery has been intensively examined since the 1970s, with researchers looking at its electrochemical time varying electrolyte concentration time variation equations (both tank and cells, for negative and positive half cells), its thermal time variation equations, and fluid flow equations. Chemistry behavior of the electrolyte ions have also been intensively examined too. Our focus in this treatment is an approach to understanding the basic physics, chemistry, and electronics of the VRFB with a view towards practical engineering and manufacturing assessments and designs. Here we develop as rigorously as possible analytical formulas to specify the behavior of the surface and bulk like concentrations in the electrode regions of the battery, which are structurally made of porous materials. It is not necessary that the negative and positive electrodes be made of the same material, thicknesses, nor even with the same porosities.