Abstract:

A three-dimensional non-isothermal numerical model was developed for proton exchange membrane fuel cells (PEMFCs) with conventional and interdigitated flow fields.The heat and mass transfers and the electrochemical reactions of reactant gases in fuel cells were included in the model.The investigation was concentrated on the electro-osmotic drag and the diffusion effects of liquid water in the membrane, and the species transport in porous media.The effects of transport limit of oxygen and water transport in the membrane on the cell performance were analyzed and discussed.The results indicated that the interdigitated design of flow channel enhanced the mass transport of gases in porous media and improved the output performance of fuel cell.However, the reduction of water at the interface of cathode catalyst layer could deteriorate the hydration degree of membrane, which required more effective water management to keep the membrane from dehydration.