Reaction Gas Pressure, Temperature, and Membrane Water Content Modulate Electrochemical Process of a PEMFC: A Simulation Study

Abstract

Proton exchange membrane fuel cells (PEMFC) are widely used in transportation systems owing to their desirable characteristics such as high efficacy and low operating temperature. However, the fuel cell systems exhibit load changes as well as voltage and power losses so as to reduce dependence on the battery. The aim of the present study was to explore the composition and basic working principle of PEMFC. A PEMFC electrochemical reaction model was then established according to the electrochemical reaction principle of fuel cell to evaluate the effects of Nernst electromotive force, activation overvoltage, Ohmic overvoltage, concentration overvoltage, and electric double layer. The effects of activation loss, concentration loss, and Ohmic loss on the fuel cell were evaluated through simulation analysis. The effect of various factors on the dynamic output of a 60 kW PEMFC was explored through dynamic simulations. The findings showed that a change in current modulated a change in voltage through the Ohmic loss equivalent resistance. The activation loss equivalent resistance and the concentration loss equivalent resistance decreased the voltage loss owing to the presence of the capacitor. The output voltage of the fuel cell decreased with an increase in load current, whereas the output power increased with an increase in load current. Increase in partial pressure of oxygen caused an increase in output power and output voltage of the cell. The internal chemical reaction rate and the voltage output of the fuel cell increases with an increase in the working temperature. The findings of this study provide a basis for conducting further studies to produce efficient fuel cells for application in various systems.