Previous studies [18, 19] have indicated that a novel ribbed PZT-PEMFC design has been developed, and that a three-dimensional, transitional model has been successfully built to study its major characteristics and fuel cell performance. A ribbed cathode channel can reduce internal resistance and double current density. At a higher PZT vibration frequency (f = 64 Hz), an air-breathing PZT-PEMFCs device compresses more oxygen into the catalyst layer and thus enhances the electrochemical reaction, resulting in a higher current output. On the other hand, the accumulated water vapor may be pumped out from the cathode channel during the compression process. Previous studies [11, 12] also demonstrated that serpentine and interdigitated flow fields could induce better performance than other flow fields in traditional PEMFCs, such as parallel and pin-type. In this study, the 3-D theoretical model of PZT-PEMFCs has been successfully developed in order to investigate the effects of anode and cathode channel designs on the performance of PZT-PEMFCs. Different cathode open area ratios, which are 80.5%, 63.2%, 47.9%, and 34.7%, were chosen for consideration of current density, PZT vibration frequency, and species concentrations. The results show that the cathode open area ratio of 47.9% is a better choice than 80.5%, 63.2%, or 34.7%. The results also establish that a lower vibration frequency may draw less air into the cathode channel, cause water vapor accumulation in the space of the electrochemical reaction area, and ultimately cause a drop in current over time. On the other hand, the designs of the anode flow field are found to have a big influence on the current density and water vapor profiles. The simulation results prove that the interdigitated flow field in the anode side, which is different from the traditional PEMFCs, performs much better than the serpentine and parallel flow fields.

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