Abstract:
The proton exchange membrane fuel cell (PEMFC) is one of the most promising candidate as a clean and power source for small electrical devices and vehicles because of its high energy conversion efficincy, low or zero noxious emission of environment pollutant, low operating temperature and relatively quick start-up. Due to the complexity in structure inside the PEMFC, the understanding of mechanism of fuel cell is more important. This work was carried out to study the influence of several parameters on the performance of the PEMFC by using the electrochemical impedance spectroscopy (EIS). The applied frequency was in the range of 50 mHx-10 kHz. The experiments were conducted by using the 2k factorial design to identify the effects of various parameters including cell voltage (0.55-0.8 V), flow rates of gaseous fuels (80-200 sccm) and cell temperature (39-70 ํC) at the saturated humidification condition and 60% humidification condition in the anode and cathode, side, respectively. The preliminary results indicated that the cell temperature, the cell voltage and the interaction of cell voltage, flow rates of hidrogen and oxigen had significant effect on the cell performance. In addition, the flow rate of oxigen had a strong effect on the ohmic resistance and the charge transfer resistance in the system. The model equations describing the relationship of above parameters and various kinds of resistances in system and the optimum condition were determined in this study.