Theoretical analyses of the performance parameters of PEM fuel cells at various operating temperatures and pressures

In the present study, the performance parameters for a single-cell PEM fuel cell with 50 cm2 active surface area and 0.0178 cm polymer membrane thickness at 4 different operating temperatures (303, 323, 343, and 363 K) and 4 different operating pressures (3, 6, 9, and 12 atm) was investigated by theoretical analysis. Hydrogen and oxygen partial pressures, membrane resistivity, internal resistance, activation, ohmic and concentration losses, cell voltage, power density, and thermal efficiency were calculated using this analysis. It has been observed that the augmentation of temperature and pressure in the fuel cell leads to a favorable increase in cell voltage, power density, and thermal efficiency. The thermal efficiency values were found to be 23% and 39%, respectively at the following conditions: temperatures of 303 K and 363 K, current density of 1 A/cm2, and constant pressure. At the same current density, the thermal efficiency is 29% and 32% at 3 atm and 12 atm operating pressures at a constant temperature. When operated under constant current density and temperature conditions, an increase in the operating pressure of the PEMFC from 3 atm to 12 atm results in a corresponding increase in cell voltage, from 0.4422 V to 0.4755 V, respectively. It was observed that the influence of temperature on the thermal efficiency of the PEM fuel cell was led to be higher than the influence of pressure.