Analytical models for PEM fuel cell impedance

The book reports recently developed analytical physics based models for impedance of a polymer electrolyte membrane fuel cell. Chapter 1 discusses the transient macro-homogeneous model for the cathode catalyst layer. This model forms a basis for all impedance models discussed in this book. Chapter 2 reports solvable analytical impedance models. These models are very fast; the respective numerical algorithms for fitting impedance spectra yield the result in just several minutes on a standard PC. However, the assumptions behind the model equations limit their validity by the cell current density of about a hundred mA cm^{-2}. Chapter 3 presents a more general numerical model valid for the cell currents up to 1 A cm2. However, the fitting algorithm based on this model is rather slow; typical variant takes from one to ten hours on a standard PC. A much faster algorithm can be constructed based on approximate analytical expression for the high--current cell impedance, which concludes this Chapter. The book could be useful to fuel cell developers, researchers and students in the field of fuel cell science. Maple worksheets with codes from this book for fitting experimental impedance spectra can be downloaded from https://github.com/akulikovsky/Fitting_Procs/issues/1