Multiscale modeling of single-phase multicomponent transport in the cathode gas diffusion layer of a polymer electrolyte fuel cell

This research reports a feasibility study into multi-scale polymer electrolyte fuel cell (PEFC) modelling through the simulation of macroscopic flow in the multi-layered cell via 1D electrochemical modelling, and the simulation of microscopic flow in the cathode gas diffusion layer (GDL) via 3D single-phase multi-component lattice Boltzmann (SPMC-LB) modelling. The heterogeneous porous geometry of the carbon-paper GDL is digitally reconstructed for the SPMC-LB model using X-ray computer micro-tomography. Boundary conditions at the channel and catalyst layer interfaces for the SPMC-LB simulations such as specie partial pressures and through-plane flow rates are determined using the validated 1D electrochemical model, which is based on the general transport equation (GTE) and volume-averaged structural properties of the GDL. The calculated pressure profiles from the two models are cross-validated to verify the SPMC-LB technique. The simulations reveal a maximum difference of 2.4% between the thickness-averaged pressures calculated by the two techniques, which is attributable to the actual heterogeneity of the porous GDL structure. 1 Department of Aeronautical and Automotive Engineering, Loughborough University, Leicestershire LE11 3TU, United Kingdom 2 Corresponding author: [email protected] 3 Department of Mechanical Engineering, University of Birmingham, Birmingham B15 2TT, United Kingdom 4 Department of Engineering, University of Liverpool, Liverpool L69 3GQ, United Kingdom 5 Technical Fibre Products Ltd., Kendal LA9 6PZ, United Kingdom 2