Solid State Ionics is a rapidly developing key technology that will have a tremendous impact on many aspects of our lives, our environment, and our economy. Applications range from high-performance solid-state batteries to medium-temperature solid-state fuel cells, solid-state electrolysis cells for hydrogen production, chemical sensors, solar cells, electrochromic windows and - displays, and much more. Fast solid ionic conductors offer new possibilities due to their numerous advantages over conventional liquid electrolytes.