Validation of 1D porous electrode theory using steady-State measurements of flooded electrodes at variable electrolyte compositions

Abstract

Steady-state measurements were performed using flow-through cells and electrolyte solutions spanning a wide range of concentrations of ferrous/ferric ions as active species and supporting salts (hydrochloric acid, sodium chloride, cesium chloride). Voltage losses obtained from steady-state polarization curves and impedance measurements were analyzed using Newman’s porous electrode model. The results showed that the model accurately predicts the electrode performance for commonly used concentrated electrolyte solutions but deviates substantially for low levels of supporting electrolyte (particularly for sodium chloride). Effects of mass transport and diffuse double layer effects are discussed to account for the nonlinear voltage losses.