Performance characteristics of novel magnetic-field applied polymer electrolyte membrane fuel cells under various operating conditions

In this study, the oxygen reduction reaction (ORR) performance improvement of polymer electrolyte membrane fuel cells (PEMFCs) is investigated using a low magnetic field density. The transient performance of a PEMFC using a magnetic field (MF-PEMFC) was measured and analyzed by varying the cell temperature, voltage, relative humidity, and pre-humidification time. Based on the results, the mechanism of the performance improvement of MF-PEMFC was revealed, and a strategy to maximize its performance was proposed. Enhanced oxygen mobility by a magnetic field led to a higher ORR performance and membrane humidification was accelerated by the vigorous ORR. The performance improvement of MF-PEMFC was more substantial under unfavorable membrane humidification conditions such as high temperature and low operating voltage. The maximum performance improvement of MF-PEMFC compared to that of normal PEMFC was 8.6% at 40% relative humidity, 0.30 V voltage, and 80 ℃ cell temperature due to an enhanced self-humidification effect. In addition, the maximum performance improvement and stability of MF-PEMFC were obtained with the proper pre-humidification time. In conclusion, using a magnetic field can improve the performance and stability of PEMFCs under unfavorable operating conditions.