Fuel Cells have become a potentially highly efficient sustainable source of energy and electricity for an ever-demanding power hungry world. The two main types of fuel cells ripe for commercialisation are the high temperature solid oxide fuel cell (SOFC) and the low temperature polymer electrolyte membrane fuel cell (PEM). The commercial uses of which include, but are not limited to, military, stand-by power, commercial and industrial, and remoter power. However, all aspects of the electricity market are being considered. This book has brought together a team of world-renowned experts in all aspects of fuel cell development for both SOFC and PEM in a workshop environment. The workshop held between June 610, 2004 was held in the capital city of the Ukraine, Kiev. The reason for the venue was that Ukraine is the third largest resource of zircon sands, a major source of material for the solid oxide fuel cell. Ukraine is looking at undertaking a very large effort in the solid oxide fuel cell arena, and hopes, one day, to be an international player in this market, and this book is an outcome from the workshop. The book focuses on the issues related to fuel cells, particularly the state-of-the-art internationally, the issues that were of particular interest for getting fuel cells fully commercialized, and advances in fuel cell materials and technology. The focus was on all types of fuel cells, but the emphasis was particularly on solid oxide fuel cells (SOFC), due to their importance to the host country. The book is an essential reference to researchers, academics and industrialists interested in up-to-date information on SOFC and PEM development.