Sensitivities of critical operating conditions on proton exchange membrane fuel cell performance: An experimental study

The performance of the Proton Exchange Membrane Fuel Cell (PEMFC) is subject to substantial influence from operating conditions. In this paper, the impact of various operating conditions on the polarization curves is examined through single-variable polarization curve tests. Notably, it is observed that the polarization curves intersected within the range of 1.0 A/cm2 to 1.5 A/cm2 under varying cathode inlet humidity and working pressure conditions. Expanding upon this observation, an orthogonal experiment is designed and executed to evaluate the sensitivity of PEMFC performance to diverse operating conditions under two distinct current densities of 1.0 A/cm2 and 2.0 A/cm2. Consequently, it is revealed that the output voltage, charge transfer impedance, and mass transfer impedance are most significantly influenced by three specific operating conditions: temperature, cathode inlet humidity, and stoichiometric ratio. Furthermore, as the current density increases, the dominant factors governing PEMFC performance have evolved from temperature-dominated charge transfer impedance to cathode stoichiometric ratio-dominated mass transfer impedance.