Operation Characteristics of Open-Cathode Proton Exchange Membrane Fuel Cell with Different Cathode Flow Fields

Abstract

Open-cathode proton exchange membrane fuel cell (PEMFC) is considered as a promising power source for unmanned aerial vehicles and portable applications due to its simple structure and low parasitic power. In this study, the operating condition effects of the open-cathode PEMFC with different cathode flow fields (parallel, pin-type, and metal foam) are investigated experimentally. Polarization curve and electrochemical impedance spectroscopy (EIS) are tested to characterize the cell performance and electrochemical impedance, respectively. The results show that the cell with the metal foam flow field has better performance than that with the other flow fields in the baseline conditions. Although increasing the fan voltage could provide adequate reactant gas and remove excess water, too large air flow rate could reduce membrane water content and decrease temperature that is bad for the cell performance. Increasing the operating temperature would improve the cell performance, but the increase of ohmic resistance caused by higher water evaporation rate cannot be neglected. The cell performs stably with increasing the anode backpressure in the low current density region, while the cell performance decreases with increasing the anode backpressure in the high current density region.