An advanced 1D physics-based model for PEM hydrogen fuel cells with enhanced overvoltage prediction

TL;DR

This work develops a one-dimensional, dynamic, two-phase, isothermal PEM fuel cell model that balances computational efficiency with physical fidelity, validated against static polarization curves. A key contribution is the introduction of the limit liquid water saturation coefficient $s_{lim}$, which links high-current voltage losses to liquid water content and operating pressure, replacing the conventional $i_{lim}$. The model also includes a crossover correction $\kappa_{co}$ and is implemented in the open-source AlphaPEM framework, enabling rapid, control-oriented analysis of both the cell and balance-of-plant dynamics. The results demonstrate substantial speed advantages over higher-dimensional models while maintaining reasonable accuracy for static validation, with ongoing work aimed at extending to heat transfer, electrochemical impedance spectroscopy, and enhanced BoP modeling. The approach offers practical impact for real-time diagnostics and model-based control of PEMFC systems in embedded applications.

Abstract

A one-dimensional, dynamic, two-phase, isothermal model of proton exchange membrane fuel cell systems using a finite-difference approach has been developed. This model balances the simplicity of lumped-parameter models with the detailed accuracy of computational fluid dynamics models, offering precise internal state descriptions with low computational demand. The model's static behavior is validated experimentally using polarization curves. In addition, a novel physical parameter, the limit liquid water saturation coefficient ($s_{\rm lim}$), is introduced in the overvoltage calculation, replacing the traditional limit current density coefficient ($i_{\rm lim}$). This new parameter links the voltage drop at high current densities to the amount of liquid water present in the catalyst layers and the operating conditions of the fuel cell. Additionally, it has been observed that $s_{\rm lim}$ is influenced at least by the gas pressure applied by the operator. This newly established link is promising for optimizing the control and thereby improving the performance of fuel cells.

Figures (9)

• Figure 1: 1D modeling of matter transport phenomena in a PEM single cell divided into several nodes
• Figure 2: The studied simplified structure of a PEMFC system, consisting of a forced-convective cathode and anodic recirculation.
• Figure 3: Plot of the liquid water induced voltage drop function, expressed as a function of the liquid water saturation in the CCL, for $P_{des} = 2.5$ bar, $a_{s_{lim}} = 0.05$, $b_{s_{lim}} = 0.1075$ and $a_{switch} = 0.705$
• Figure 4: Comparison of polarization curves between simulation and experiment to validate the model's static behavior.
• Figure 5: Internal states of a PEM fuel cell system for two current density steps, computed by AlphaPEM (1/3).