Numerical Simulation of Advanced Bipolar Plates Materials for Hydrogen-Fueled PEM Fuel Cell

Hydrogen-fueled Proton Exchange Membrane Fuel Cells (PEMFC) are considered one of the most prom- ising technologies for a fully sustainable power generation in the transportation sector, thanks to the direct conversion of chemical-electrical energy, the absence of harmful emissions, the optimal power density, and the allow- able long-distance driving range. A current technological issue preventing their large-scale industrialization is the thermal management of PEMFC stacks, due to the absence of the heat removal action operated by exhaust gases in internal combus- tion engines, the low-temperature generated heat and the limited exchange areas in mobile applications. A relevant role in heat dissipation is played by bipolar plates, being the components with the largest volume occupation and greatly contributing to the PEMFC weight and cost. This motivated the recent research on advanced materials for these components, aiming at simultaneous elevated electrical and thermal conductivity, reduced contact resistance, poor oxida- tion tendency and low density. In this study a fundamental multi-dimensional and multi-physics 3D-CFD analysis is carried out to evaluate the effect on the membrane physical/electrochemical status for different types of bipolar plates, moving from conventional graphite to advanced materials, including coated stainless steel. A detailed analysis is carried out on the fuel cell thermal management, rationalizing the heat dissipation pathways and the membrane hydration balance for the considered cases. The study relevantly shows the effects of advanced research on bipolar plates materials on a cell-scale, filling a knowledge gap between the fundamental research on bulk material prop- erties for bipolar plates and the resulting PEMFC fluid/ thermal processes, thus providing guidelines for PEMFC engineering advancement.