Experimental and numerical study of the enhancement effects on the performance of PEMFC with side blockage in straight flow-field

Flow channel design is a hot research topic of proton exchange membrane fuel cells (PEMFCs). An innovation straight with side blockage flow channel is proposed to investigate the enhancement effects on mass transportation and performance of PEMFCs by combing the numerical simulation and experimental study. Compared to traditional channel, cathode flow channel with double-side blockage shows the best performance with up to 10% improvement at 1800 mA cm-2. Electrochemical impedance spectroscopy (EIS) measurements are carried out to analyze the mechanism of the performance improvement during experimental tests. The equivalent resistance of activation and concentration losses decreases due to the enhancement of charge and mass transfer with the increase of temperature and the arrangement of side blockages, leading to the performance improvement. Along with the output performance improvement, the pressure drops of flow channels with blockages are higher than traditional channel. Thus synergy angle and cost-benefit ratio are used to evaluate the superiority of the flow field design through numerical simulation. The double-side blockage flow channel exhibits greater capacity of mass transfer and larger cost-benefit ratio, consisting with the cell performance variation characteristics.