Sensitivity Analysis of PEMFC Operating Conditions Based on the Distribution of Relaxation Time

Internal polarization dynamics process analysis of the proton exchange membrane fuel cell (PEMFC) and its parameter influence study under different operating conditions is a necessary condition for ensuring that the fuel cell operates in optimal condition. Existing studies on the impact of operating conditions on fuel cell performance are frequently qualitative and lack quantitative indicators of influential sensitivity. In this paper, taking the PEMFC used in the laboratory as the example, the influence of different operating conditions on the voltage was obtained by a univariate polarization curve experiment. Firstly, the orthogonal experiment under 1.0 A/cm² and 2.0 A/cm² was designed and carried out. And then, introducing distribution of relaxation times (DRT) method and the equivalent circuit model (ECM), the sensitivity of different operating conditions to voltage and polarization resistance was quantified. The results show that the three operating conditions of operating temperature, cathode inlet humidity, and stoichiometric ratio are the most sensitive to the output voltage, charge transfer impedance, and mass transfer impedance under two current densities. Along with the increase in current density, the influence mode of operating conditions on fuel cell performance can change from temperature-dominated charge transfer impedance to cathode stoichiometric ratio-dominated mass transfer impedance.