WATER MANAGEMENT STUDIES IN AUTOMOTIVE FUEL CELL
The management of water in a polymer electrolyte membrane (PEM) fuel cell running at a set current is provided in a simplified form. In a two-dimensional slice from the inlet to the exit and across the membrane, the consumption of gases in the flow field channels is associated with the electric potential and water content in the polymer membrane. Particular consideration given to the sensitivity of along-the-channel current density to inlet humidity levels, the make-up of the gas stream, and the stoichiometry of the fuel and oxygen. For proper fuel cell modeling, it is discovered that the parameters defining the nonequilibrium kinetics of the membrane/catalyst interface are crucial. The modeling of nonequilibrium membrane water uptake rates uses a novel parameter. In subsequent runs that compare polarization curves, current density and membrane hydration distributions, water transfer, and stoichiometric sensitivity to the remaining experimental data, four parameters—the exchange current, a membrane water transfer coefficient, an effective oxygen diffusivity, and an average membrane resistance—are fitted to a subset of data and then held constant.
Hydrogen energy, fuel cell, electrochemistry, flooding, PEMFC