Direct numerical simulation (DNS) modeling of PEFC electrodes: Part I. Regular microstructure

A direct numerical simulation (DNS) model is developed to achieve pore-level description of polymer electrolyte fuel cell (PEFC) electrodes. The DNS method solves point-wise accurate conservation equations directly on an electrode microstructure comprising of various phases and hence utilizes the intrinsic transport properties of each phase. Idealized two- and three-dimensional regular microstructures are constructed to represent the porous cathode catalyst layer. Various voltage losses identified from the simulation results are compared with experimental observations. This pore-scale model is further applied to study the morphological effects, such as pore size, layer thickness and porosity, on the performance of the cathode catalyst layer.