Strategies for effective utilization of hydrogen in cylindrical PEM fuel cells

Cylindrical PEM fuel cells have higher volumetric and gravimetric power density compared to planar PEM fuel cells because of the absence of graphite bipolar plates. The performance of the cylindrical fuel cell is largely influenced by MEA compression. In this study, we have developed a cylindrical fuel cell with hollow semi-cylinders acting as the cathode current collector. This design allows for increasing MEA compression without increasing cathode current collector thickness. The decrease in hydrogen flow rate and an increase in hydrogen humidification temperature further increased the cylindrical cell performance. The lower limiting current density obtained at lower hydrogen flow rates can be increased by operating the cell in dead-ended mode. The better performing baffle design for anode current collector in terms of efficient hydrogen utilization is determined from CFD simulations.