Book excerpt: 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.