Current and Overpotential Distribution Mathematical Model of the Porous Electrode Based on the Three-Phase Boundary Length

Abstract

In accordance with the gas and liquid distribution theory of a porous medium, the current and the overpotential distribution of the porous electrode were studied. Based on the analysis of the electric conductance of the solution, the Ohm’s law of the solution considering the gas and liquid distribution in the porous electrode is given. The effective three-phase boundary length of the electrochemical reaction is defined and calculated. According to the definition, a one-dimensional current and an overpotential distribution mathematical model of the porous electrode is established based on the mathematical model of the single-pore electrode and calculated by the numerical iteration method. The influence of gas saturation and effective three-phase boundary length to the current and overpotential distributions are also discussed. © 2005 The Electrochemical Society. All rights reserved.