Parametric Study of Proton-Exchange-Membrane Fuel Cell Cathode Using an Agglomerate Model

An agglomerate model on the cathode part of the proton-exchange-membrane fuel cell is developed. A parameter estimation scheme is imposed on the model to retrieve useful mass-transfer and electrochemical kinetics data. Experimental observations on the effects of oxidant composition and solid polymer electrolyte loadings on cell performance are qualitatively predicted using this model. This model gives the trend of polarization curve as a function of gas void fraction, and loadings of catalyst and solid polymer electrolyte within the catalyst layer. The effect of the catalyst layer thickness is simulated as a function of cell operating conditions and chemical/physical structure of the electrode. The relative effects of gas-phase mass transfer, oxygen diffusion, and proton migration in the solid polymer phase, and catalyst surface electrochemical kinetics are evaluated. The consequence of electrode structure and possible directions of electrode improvement are discussed. © 2005 The Electrochemical Society. All rights reserved.