Book excerpt: This book describes, for the first time in a modern text, the fundamental principles on which solid state electrochemistry is based. In this sense it is in contrast to other books in the field which concentrate on a description of materials. Topics include solid (ceramic) electrolytes, glasses, polymer electrolytes, intercalation electrodes, interfaces and applications. The different nature of ionic conductivity in ceramic, glassy and polymer electrolytes is described as are the thermodynamics and kinetics of intercalation reactions. The interface between solid electrolytes and electrodes is discussed and contrasted with the more conventional liquid state electrochemistry. The text provides an essential foundation of understanding for postgraduates or others entering the field for the first time and will also be of value in advanced undergraduate courses.