Development of Semi-Empirical Cell Voltage Model for Direct Methanol Fuel Cell

Abstract

A new semi-empirical model is established to describe the cell voltage of a direct methanol fuel cell (DMFC) as a function of current density. The proposed model focuses on very unfavorable conditions for the cell operation, i.e. low methanol solution concentrations and relatively low cell temperatures. . The model equation is validated experimental data over a wide range of a methanol concentration and temperatures. A number of existing models are semi-empirical. They, however, have a serious mathematical defect. In their models, when the current density, j , becomes zero, the cell voltage goes to the infinity. A newly developed semi-empirical equation corrects this mathematical defect and includes the methanol crossover effect that plays a major role in determining the cell voltage of DMFC. The model equation is validated experimental data over a wide range of a methanol concentration and temperature.