A Multi-Field Coupled PEMFC Model with Force-Temperature-Humidity and Experimental Validation for High Electrochemical Performance Design

Abstract

PEMFCs (Proton Exchange Membrane Fuel Cells) are commonly used in fuel cell vehicles, which facilitates energy conversation and environmental protection. The fuel cell electrochemical performance is significantly affected by the contact resistance and the GDL (Gas Diffusion Layer) porosity due to ohmic and concentration losses. However, it is difficult to obtain the exact performance prediction of the electrochemical reaction for a fuel cell design, resulting from the complex operating conditions of fuel cells coupled with the assembly force, operating temperature, relative humidity, etc. Considering the compression behavior of porosity and the contact pressure in GDLs, a force-temperature-humidity multi-field coupled model is established based on FEA (Finite Element Analysis) and CFD (Computational Fluid Dynamics) for the fuel cell electrochemical performance. Aside from that, the characteristics between the contact resistance and the contact pressure are measured and fitted through the experiments in this study. Finally, the numerical model is validated by the experiment of the fuel cell stack, and the error rate between the presented model and the experimentation of the full-dimensional stack being a maximum of 3.37%. This work provides important insight into the force-temperature-humidity coupled action as less empirical testing is required to identify the high fuel cell performance and optimize the fuel cell parameters in a full-dimensional fuel cell stack.