In this study, a new proton exchange membrane fuel cell (PEMFC) was assembled with a gold-coated nickel foam instead of conventional flow-field (carbon plate), and its performance which was related to operational parameters was evaluated by DC polarization and electrochemical impedance spectroscopy (EIS) technologies. Parameters such as operation temperature, temperature of cathode humidification and chemical stoichiometry in the cathode were of concern. The results revealed that the cell power density increased from 326.6 mW/cm2 to 706.7 mW/cm2, and the mass-transfer resistance decreased from 0.030 Ω to 0.010 Ω, with an increase in the operation temperature of the cell from 40 °C to 60 °C. It was found that an operation temperature of lower than 40 °C would deter the mass transfer rate of the oxygen reduction reaction (ORR). When the humidification temperature at the cathode increased from 50 °C to 70 °C, the cell power density decreased from 733.6 mW/cm2 to 622.3 mW/cm2. This decrease was ascribed to an increase in charge-transfer resistance of the cell from 0.040 Ω to 0.100 Ω, possibly caused by partial flooding. In addition, the performance of the cell was greatly improved when the chemical stoichiometry at the cathode was increased from 2 to 5. In summary, a maximum cell power density (i.e., 791.6 mW/cm2) could be achieved with a cell operation temperature of 60 °C, a humidification temperature 50 °C at the cathode, and a chemical stoichiometry of 5 at the cathode for this PEMFC assembled with Au-coated nickel foams.
- Metal foam
- Oxygen reduction reaction