Solid-state electrochemical devices, such as batteries, fuel cells, membranes, and sensors, are becoming pervasive in our technologically driven lifestyles. The development of these devices involves common research themes such as ion transport, interfacial phenomena, and device design and performance, regardless of the class of materials or whether the solid state is amorphous or crystalline. However, results of recent research in this field tend to be presented in symposia separated along the lines of particular solidstate materials disciplines rather than by phenomena controlling device performance. The papers in this issue of ECS Transactions were presented at the fifth of a series in international symposia "Solid-State Ionic Devices V", at the 212th Electrochemical Society Meeting, in Washington DC, October 7-12, 2007. The intent of the symposia was to provide a forum for current advances in ionically conducting materials and devices that is organized along phenomenological lines, rather than by specific material discipline. The papers in this issue range from the fundamentals of ionic and mixed ionic-electronic transport to device performance and are in keeping with that intent.

Solid-state electrochemical devices, such as batteries, fuel cells, membranes, and sensors, are critical components of technologically advanced societies in the 21st Century and beyond. The development of these devices involves common research themes such as ion transport, interfacial phenomena, and device design and performance, regardless of the class of materials or whether the solid state is amorphous or crystalline. The intent of this international symposia series is to provide a forum for recent advances in solid-state ion conducting materials and the design, fabrication, and performance of devices that utilize them. The papers in this issue of ECS Transactions were presented at the 6th Solid State Ionic Devices symposium, at the 214th meeting of The Electrochemical Society, October 12-17, 2008 in Honolulu, Hawaii.

Introduction to Solid State Ionics: Phenomenology and Applications presents a pedagogical, graduate-level treatment of the science and technology of superionic conductors, also known as fast ion conductors or solid electrolytes. Suitable for physics, materials science, and engineering researchers and students, the text emphasizes basic physics and

Solid-state batteries hold the promise of providing energy storage with high volumetric and gravimetric energy densities at high power densities, yet with far less safety issues relative to those associated with conventional liquid or gel-based lithium-ion batteries. Solid-state batteries are envisioned to be useful for a broad spectrum of energy storage applications, including powering automobiles and portable electronic devices, as well as stationary storage and load-leveling of renewably generated energy. This comprehensive handbook covers a wide range of topics related to solid-state batteries, including advanced enabling characterization techniques, fundamentals of solid-state systems, novel solid electrolyte systems, interfaces, cell-level studies, and three-dimensional architectures. It is directed at physicists, chemists, materials scientists, electrochemists, electrical engineers, battery technologists, and evaluators of present and future generations of power sources. This handbook serves as a reference text providing state-of-the-art reviews on solid-state battery technologies, as well as providing insights into likely future developments in the field. It is extensively annotated with comprehensive references useful to the student and practitioners in the field.