Preface Chapter 1 Introduction Chapter 2. Modifications of sulfonic acid-based membranes 2.1 Introduction 2.2 Composites membranes containing inorganic fillers 2.2.1 Composite PFSA membranes for direct methanol fuel cells (DMFC)s 2.2.2 Composite hydrocarbon membranes for DMFCs 2.2.3 Short-side chain PFSA membranes for DMFCs 2.4 Composite PFSA membranes for direct ethanol fuel cells 2.3 Composite and modified PFSA membranes for intermediate temperature PEM electrolysis 2.3.1 General aspect of PEM electrolysis 2.3.2 Intermediate temperature PEM electrolysis 2.3.3 Short side chain membranes for PEM water electrolysis 2.4 Short side chain PFSA membranes 2.5 Conclusions References Chapter 3 Acid-base chemistry and proton conductivity 3.1 Introduction 3.2 Thermodynamics of acid-base chemistry 3.3 Hydrogen bonds 3.3.1 Hydrogen bonds and their correlation with pKa 3.3.2 Degree of proton transfer of carboxylic acid and N-base systems 3.4 Ionicity of protic liquids and solids 3.4.1 Protic ionic liquids 3.4.2 Protic solid crystals 3.4.3 1H NMR chemical shift 3.4.4 The Walden rule and Grotthuss mechanism 3.5 Acid-base polymer membranes 3.5.1 Acid doped polybase membranes 3.5.2 Base-doped acidic polymer membranes 3.5.3 Polyacid-polybase membranes 3.5.4 Malfunction of phosphoric acid doped perfluorinated sulfonic acid membranes 3.6 Acid-base interactions in inorganic solid acids 3.7 Conclusive remarks Acknowledgements References Chapter 4. Applications of acid-base blend concepts to intermediate temperature membranes 4.1 Introduction 4.2 State of the art of the application of acid-base blend concepts 4.3 Short comparative study of the stability and properties of PBI-type membranes 4.3.1 Thermal stability of the blend membranes 4.3.2 Cross-linking degree/insoluble fraction by immersion in 90 °C hot DMAc 4.3.4 Proton conductivity of H3PO4-doped membranes 4.4 Conclusions References Chapter 5: Pyridine Containing Aromatic Polyether Membranes 5.1 Introduction 5.2 Synthesis of linear aromatic polyethers containing main chain pyridine units 5.3 Side group functionalized linear aromatic polyethers containing main chain pyridine units 5.4 Cross-linked aromatic polyethers bearing pyridine main chain units 5.5 Interaction of phosphoric acid and water with the polymer membranes 5.5.1 Equilibrium hydration levels of water in the H3PO4 imbibed membranes 5.5.2 Stability and volatility of H3PO4 in the imbibed membranes 5.5.3 Steam permeability through the membrane 5.6 Application in HT-PEMFCs operating up to 220 °C 5.6.1 Linear polymeric membranes 5.6.2 Cross-linked membranes 5.7 Conclusions Acknowledgements References Chapter 6 Techniques for PBI membrane characterization 6.1 Introduction 6.2 Molecular weight of PBI 6.2.1. Definitions 6.2.2 Viscosity 6.2.3 Size exclusion chromatography 6.3 Water and phosphoric acid uptake 6.3.1 Water uptake of pristine PBI membranes 6.3.2 Phosphoric acid uptake 6.3.3 Dimensional changes 6.4 Conductivity 6.4.1 Definitions and equations 6.4.2 Conductivity cells 6.4.3 Temperature dependence and activation energy 6.5 Solubility and gel contents 6.5.1 Solubility 6.5.2 Filtration of PBI solutions 6.5.3 Gel content 6.6 Mechanical properties 6.6.1 Tensile stress and strain 6.6.2 Tensile testing 6.6.3 Indentation, compression and creep 6.6.4 Dynamic mechanical analysis 6.7 Permeability, methanol crossover and electro-osmotic drag 6.7.1 Gas permeabilities 6.7.2 Electrochemical stripping method for hydrogen permeability measurements 6.7.3 Methanol crossover 6.7.4 Electro-osmotic drag of water 6.8 Thermal and oxidative stability 6.8.1 Thermal stability 6.8.2 Oxidative stability by Fenton test 6.9 Humidity definition and control 6.9.1 Saturated water vapor pressure, relative humidity and dew point 6.9.2 Control of water content Acknowledgements References Chapter 7 Synthesis of Polybenzimidazoles 7.1 Introduction to polybenzimidazoles 7.2 Procedures for synthesis of PBIs 7.2.1 Solvent free synthesis 7.2.2 Homogeneous solution polyme
About the Author: Qingfeng Li is a professor at Department of Energy Conversion and Storage, Technical University of Denmark. His research areas include proton conducting electrolytes, electrocatalysts and the related technologies particularly fuel cells and electrolysers. He received his Ph.D. in electrochemistry from Northeastern University, China, in 1990 and was awarded Doctor Degree of Technices at DTU in 2006. As a postdoc he started in the middle of 1990´s the research on high temperature polymer electrolyte membrane fuel cells at DTU. He has participated/coordinated more than 20 EU and Nordic research projects within the fuel cell area and is currently the leader of 4M Centre devoted to fundamental research on mechanisms, materials, manufacturing and management of high temperature polymer electrolyte membrane fuel cells, funded by the Danish Council for Strategic Research. He is an active member of, among other, the Electrochemical Society and the International Society of Electrochemistry (and currently the region representative of Denmark 2012-now). Prof. Li has been involved in teaching at all DTU levels including a lecturing and an experimental course on Hydrogen Energy and Fuel cells.
David Aili obtained his MSc degree in Organic Chemistry in 2007 from the Institute of Technology at Linköping University after a diploma project at the Arrhenius Laboratory, Stockholm University. He subsequently moved to Technical University of Denmark to pursue a PhD in the field of proton conducting membranes for electrochemical energy conversion technologies under the supervision of Professor Niels Bjerrum at the Department of Chemistry. After obtaining his PhD degree in 2011 and after a shorter period as a development engineer in the in the phenolic resin business, he joined the newly formed Department of Energy Conversion and Storage at Technical University of Denmark in 2012 as a Postdoctoral Research Fellow. His current research covers fundamental and application-oriented aspects of ion conducting materials with special emphasis on polymer-based membranes.
Hans Aage Hjuler was educated as MSc (Chemistry) at the Technical University of Denmark in 1980. In 1983 he obtained his PhD degree in Advanced Rechargeable Batteries at the Technical University of Denmark. As post-doc he formed a significant research group in batteries (from 1983) and fuel cells R&D (from 1988). He has worked with PAFC, MCFC, SOFC and PEM-based fuel cell systems and materials. He worked as laboratory manager with superconducting materials (high Tc) at NKT Research Center from 1991-94. He was director in Novo Nordisk from 1998-2009. He was one of the founders of Danish Power Systems in 1994 and chairman from 1994-2010. He was appointed Managing Director, CEO in 2010. HAH is vice-chair of the Board of Directors of the Danish Partnership for Hydrogen and Fuel Cells, member of Annex 22, International Energy Agency (IEA) Implementing Agreement on Advanced Fuel Cells. He is member of the Scientific Committee of Fuel Cell and Hydrogen Joint Undertaking (FCH-JU), European Commission, Brussels, Belgium.
Jens Oluf Jensen is a full Professor at Technical University of Denmark where he is heading the section named Proton Conductors (ca. 25 people) at Department of Energy Conversion and Storage. He is the coordinator of the technology tracks for PEM fuel cells and for low temperature electrolyzers at the department. In 1997, he received his PhD for a study on metal hydrides for batteries. Today his research fields include high temperature PEM fuel cells and alkaline electrolyzers. The approach is experimental and focused on materials like electrolytes, catalysts and electrode structures. He has initiated and coordinated numerous national and international research projects, mostly in collaboration with industry, and arranged a number of symposia/workshops. Lately he chaired the third International Carisma Conference in Copenhagen 2012 and the Danish Korean PEM Fuel cell workshop in Seoul 2013. He is a board member of the Partnership for Hydrogen and Fuel cells in Denmark. At DTU, he has taught at numerous courses and is at present involved in teaching hydrogen energy and fuel cells as well as thermodynamics.
