PrefaceOrganic-Inorganic Composite Polymer Electrolyte Membrane: Preparation, Properties and Fuel Cell Applications is intended to explore the recent developments in the area of polymer electrolyte membranes for high-temperature polymer electrolyte membrane fuel cells. This book presents a unified viewpoint of the operating principles of fuel cells, fuel cells thermodynamics and efficiency, various methodologies used for the fabrication of polymer electrolyte membranes, issues related to the chemical and mechanical stabilities of the membranes. Special attention is paid to the fabrication of electrospun nanocomposite membranes.This book discusses the developments in the fast-growing and promising area of PEM materials obtained by using hygroscopic inorganic fillers, solid proton conductors, titanium oxide, zirconia and sulphated zirconia, silica, zeolite, montmorillonite, heterocyclic solvents, ionic liquids, anhydrous H 3 PO 4 blends, heteropolyacids, etc.This book is of great importance not only to the learners but also to the more experienced fuel cell researchers, enabling a deep understanding of the organic-inorganic membranes for fuel cells, methods for the fabrication of membranes as well as properties and applications. Based on thematic topics, the book edition contains the following 17 chapters:Chapter 1 deals with the use of ionic liquids (ILs) as fuel cell electrolytes. ILs with good mechanical properties and high conductivity has great potential to fabricate polymer membranes. This chapter focuses on the recent advances in the application of ionic liquid-based polymer membranes for the development of fuel cell technology. The key factors affecting membrane performance have been nicely discussed.In Chap. 2, a review on the recent developments about organic/TiO 2 nanocomposite membranes is presented. The unique properties, such as electrical property and processability together with thermal and chemical stabilities as well as high proton conductivity at high temperatures of organic-inorganic composite systems are highlighted. v vi Preface