Chapter 2 - Proton Exchange Membrane Fuel Cells
Proton-exchange membrane fuel cells are promising devices for a variety of energy-conversion technologies. However, they have limited market penetration due to their high cost, which stems from the need to balance durability, performance, and materials. To understand and quantify these complex interactions, detailed mathematical modeling of the underlying physical phenomena is an ideal tool to describe the multiphysics. Similarly, to control the overall operation of the cell requires detailed mathematical models. In this chapter, we describe how one can model the dominant interactions and phenomena within a cell. These interactions involve several simultaneous processes including ionic resistance, gas- and liquid-phase transport, and catalytic reactions. To design and control fuel cells for efficient operation, an understanding of the interdependence of these processes across the layers of diffusion media, catalyst, and membrane is necessary, and the phenomena within each layer will be described in this chapter. In addition, current issues in the modeling of fuel cells including optimization of transport phenomena and multiphase flow, durability, and electrode structure will be introduced. The mathematical techniques and descriptions discussed in this chapter will aid scientists and engineers in understanding and designing fuel cells for various operating scenarios.