Parametric Sensitivity of a PEM Electrolyzer Mathematical Model: Experimental Validation on a Single-Cell Test Bench

Water electrolysis for hydrogen production is of great importance for the reliable use of renewable energy sources to have a clean environment. Electrolyzers play a key role in achieving the carbon-neutral target of 2050. Among the different types of water electrolyzers, proton exchange membrane water electrolyzers (PEMWEs) represent a well-developed technology that can be easily integrated into the smart grid for efficient energy management. In this study, a discrete dynamic mathematical model of a PEMWE was developed in MATLAB/Simulink to simulate cell performance under various operating conditions such as temperature, inlet flow rate, and current density loads. A lab-scale test bench was designed and set up, and a 5 cm2 PEMWE was tested at different temperatures (40–80 °C) and flow rates (3–12 mL/min), obtaining Linear Sweep Voltammetry (LSV), Cyclic Voltammetry (CV), Chrono-potentiometry (CP), and Electrochemical Impedance Spectroscopy (EIS) results for comparison and adjustment of the dynamic model. Sensitivity analysis of different operating variables confirmed that current density and temperature are the most influential factors affecting cell voltage. The parametric sensitivity of various chemical–physical and electrochemical parameters was also investigated. The most significant ones were estimated via non-linear least squares optimization to fine-tune the model. Additionally, strong correlations between these parameters and temperature were identified through regression analysis, enabling accurate performance prediction across the studied temperature range.