An Experimental Study of Scale-up, Oxidant, and Response Characteristics in PEM Fuel Cells

Abstract

It is important for fuel cell to become flexible in order to accommodate the situations of application areas for reducing costs and expanding coverage. Scale ups in series and parallel to 1-kW class proton exchange membrane (PEM) fuel cell stack are characterized experimentally with oxidant as air and oxygen. Through a serial scaled-up 4-cell stack with an active area of 25 cm 2 and a parallel scaled-up single cell with an active area of 100 cm 2 , respectively, the 1-kW class 20-cell stack with an active area of 150 cm 2 per cell is scaled up from the basic unit cell with maintaining their performances. The polarization and power curves of the 1-kW class PEM fuel cell stack with the reactants H 2 /air and H 2 /O 2 are evaluated. Sufficient power of the PEM fuel cell can operate at flexible nominal current of 40-80 A and nominal voltage of 12-15 V for providing durability and balance between cells. The 1-kW class PEM fuel cell stack is characterized through the comparison of cell voltage differences utilizing H 2 /air and H 2 /O 2 . Both cell voltages with H 2 /air and H 2 /O 2 follow well the one-twentieth of the responding stack voltages with the small difference.