Numerical Analysis of Current Distribution at Proton Exchange Membrane Fuel Cell Compared by Segmented Current Collector Cell

Abstract

In order to grasp properly proton exchange membrane fuel cell (PEMFC) power generation performances, it is necessary to know factors for water management such as diffusivity and electro-osmotic coefficient of water vapor through the membrane and factors for power loss such as active and resistive overpotentials. In this study, we have measured these factors to analyze our experimental results of PEMFC power generation tests by using our pseudo-two-dimensional simulation code. It considers simultaneously the mass, charge and energy conservation equations, and the equivalent electric circuit for PEMFC to give numerical distributions of hydrogen/oxygen concentrations, current density, and gas/cell-component temperatures. Various experimental conditions such as fuel and oxygen utilization rates, inlet dew-point temperature, averaged current density, and flow configuration (co- or counterflow) were changed, and all of the numerical distributions of current density agreed well with the measured distributions by segmented current collector. The current distributions were also obtained from hydrogen/oxygen concentration changes along the gas flow measured by gas chromatography. The current distributions measured by the two different methods coincided with each other, showing reliability of our measurement methods.