MODIFIED THIN-FILM AND AGGLOMERATE MODELS FOR ACTIVE LAYERS OF PE FUEL-CELLS

Modelling the mode of operation of catalyst active layers offers an in teresting way for predicting the working behaviour of the electrodes f or P.E. (P.E. stands both for Proton Exchange (Membrane) and for (Soli d) Polymer Electrolyte, merging the two abbreviations) Fuel Cells. Her e two modified and optimizing approaches of the thin film and the aggl omerate models are developed for studying the active layer in order to take into account the diffusion effects at both the scales of electro lyte layer and electrocatalyst particles. Therefore, the catalyst phas e is regarded as a network of nanoparticles and is no more considered classically to be uniformly distributed on a surface (thin film model) or in a volume (agglomerate model). The validation of these models is checked and discussed by comparison with the direct numerical solutio n of the transfer equations by the finite element method. (C) 1998 Els evier Science Ltd. All rights reserved.