This book focuses on the multidisciplinary teamwork for the design of key interfaces in fuel cell devices. It covers the fabrication, modelling, and operando-microanalysis sections in each chapter. Also, each chapter in the book consists of the introduction of basic theory, representative experimental results, and future prospects in each field. The book is an edited volume, intended to serve as an introductory textbook in multidisciplinary research work for the design and development of fuel cells. To fully enjoy the multidisciplinary research activities in fuel cell field, the beginners need to learn the basic knowledge and experimental data in each field. Compared with the published introductory textbooks in the field of science and engineering of fuel cells, this book has the following advantages. Firstly, it is an introductory textbook of multidisciplinary work for the design and development field of intermediate temperature (IT) solid oxide fuel cells (IT-SOFCs) and high-temperature polymer electrolyte fuel cells (HT-PEFCs) . And at the same time, this book is convenient for practical research implementation in R & D of those IT-SOFC and HT-PEFC devices. Secondly recent research topics with sufficient references are included in each chapter. Scientists and engineers in the fuel cell field will obtain useful knowledge in critical review chapters in the fabrication, modeling, and operando-microanalysis fields. Finally experimental results are closely combined with the cutting edge of scientific research work in the IT-SOFC and HT-PEFC materials and devices field. For all these reasons, this book is a useful start-up in multidisciplinary work for R & D of IT-SOFC and HT-PEFC devices.