OpenFCST: An Open-Source Mathematical Modelling Software for Polymer Electrolyte Fuel Cells

Abstract

OpenFCST (open-source fuel cell simulation toolbox) is an open-source, finite element method based, multi-dimensional mathematical modeling software for polymer electrolyte fuel cells. The aim of the software is to develop a platform for collaborative development of fuel cell mathematical models. The philosophy, structure and main components of openFCST are presented. OpenFCST currently includes physical models for gas, electron, ion, ionomer-bound water and heat transport. It also contains effective transport media relations to estimate transport properties for gas diffusion layers, micro-porous layers and catalyst layers as well as several kinetic models for the fuel cell electrochemical reactions. OpenFCST has been structured as a toolbox such that it is easier for new users to integrate new physical models with existing framework. OpenFCST is used to analyze the impact of different kinetic models on a multidimensional cathode model and to study the main differences between a macro-homogeneous and several agglomerate models. Finally, openFCST is used to develop a three-dimensional model of a patterned catalyst layer. Results show that multi-step kinetic models improve fuel cell performance predictions, macro-homogeneous and ionomer-filled agglomerate models show similar performance for 100 nm radii agglomerates up to current densities of 2 A/cm2, and water-filled agglomerate models require negative surface charges to exist at the pore walls in order to provide results in-line with experimental data. Finally, a patterned catalyst layer with micro-pores is shown to improve electrode performance.