Towards the understanding of transport limitations in a proton-exchange membrane fuel cell catalyst layer: Performing agglomerate scale direct numerical simulations on electron-microscopy-based geometries

Improving the cathode catalyst layer design requires understanding sources of transport limitations in proton-exchange membrane fuel cells. For purpose, a framework consisting on an electron microscopy characterization setup couple with numerical modeling software is proposed. The latter integrates high-performing geometry building capabilities which ensure full phase discretization (carbon, platinum, ionomer and pore phase) freedom when designing structure morphology meshing. 3D carbon extracted from focused ion beam scanning analysis having 2 nm isotropic resolution. platinum built according to nanoparticle size histogram determined high angle annular dark field transmission images. To add phase, thickness measured resolution multi-physics model includes gas pores, ionic Nafion. A 4-step reaction mechanism used solve electrochemistry. Numerical simulations are performed two portions. results show that structural heterogeneities can deeply impact performance. Such mainly linked oxygen diffusion through Nafion film and, certain extent, interparticle competition effects.