This book examines the characteristics of Proton Exchange Membrane (PEM) Fuel Cells with a focus on deriving realistic finite element models. The book also explains in detail how to set up measuring systems, data analysis, and PEM Fuel Cells’ static and dynamic characteristics. Covered in detail are design and operation principles such as polarization phenomenon, thermodynamic analysis, and overall voltage; failure modes and mechanisms such as permanent faults, membrane degradation, and water management; and modelling and numerical simulation including semi-empirical, one-dimensional, two-dimensional, and three-dimensional models. It is appropriate for graduate students, researchers, and engineers who work with the design and reliability of hydrogen fuel cells, in particular proton exchange membrane fuel cells.

Polymer electrolyte membrane (PEM) fuel cell stack was analyzed from a mechanical point of view with the help of measurements and simulations in this study. The deflection of the fuel cell stack was measured with the help of the experimental set-up under operating conditions. The effects of cell operating parameters and cyclic conditions on the mechanical properties of the fuel cell stack were investigated. In order to extend the mechanical analysis of the fuel cells, two computational models were established containing the geometrical features in detail. A large-scale fuel cell stack model was built for the thermomechanical analysis. The second model was built on a cross-section geometry for the electrochemical analysis including fluid dynamics. The internal stress distribution and buckling of fuel cell stack were examined. The influence of the mechanical compression on the cell performance and squeezing of the gas diffusion layers are investigated. A design procedure is developed for fuel cell stack regarding the durability and performance from a mechanical point of view.

Liquid water transport and oxygen diffusion within the gas diffusion layer (GDL) play key roles in the performance of a polymer electrolyte membrane (PEM) fuel cell. Understanding how liquid water and oxygen are transported through the GDL is crucial for informing future fuel cell material designs. This thesis contains two studies, one numerical and one experimental, that are focused on liquid water and gas transport in GDLs. The first study is an investigation of how liquid and gas transport in the GDL are affected by increasing microporous layer (MPL) intrusion into the carbon fiber substrate. The second study is an examination of the transport mechanisms in the MPL via the fabrication and testing of GDLs that were entirely composed of MPL (called standalone MPLs). Together, these two studies provide a deeper understanding of how novel applications of the MPL can unlock higher performance in PEM fuel cells.

For full market implementation of PEM fuel cells to become a reality, two main limiting technical issues must be overcome- cost and durability. This cutting-edge volume directly addresses the state-of-the-art advances in durability within every fuel cell stack component. [...] chapters on durability in the individual fuel cell components -- membranes, electrodes, diffusion media, and bipolar plates -- highlight specific degradation modes and mitigation strategies. The book also includes chapters which synthesize the component-related failure modes to examine experimental diagnostics, computational modeling, and laboratory protocol"--Back cover.

This book is a comprehensive review of high-temperature polymer electrolyte membrane fuel cells (PEMFCs). PEMFCs are the preferred fuel cells for a variety of applications such as automobiles, cogeneration of heat and power units, emergency power and portable electronics. The first 5 chapters of the book describe rationalization and illustration of approaches to high temperature PEM systems. Chapters 6 - 13 are devoted to fabrication, optimization and characterization of phosphoric acid-doped polybenzimidazole membranes, the very first electrolyte system that has demonstrated the concept of and motivated extensive research activity in the field. The last 11 chapters summarize the state-of-the-art of technological development of high temperature-PEMFCs based on acid doped PBI membranes including catalysts, electrodes, MEAs, bipolar plates, modelling, stacking, diagnostics and applications.