A comprehensive, accessible introduction to modern all-solid-state lithium-ion batteries. All-solid-state thin-film lithium-ion batteries present a special and especially important version of lithium-ion ones. They are intended for battery-powered integrated circuit cards (smart-cards), radio-frequency identifier (RFID) tags, smart watches, implantable medical devices, remote microsensors and transmitters, Internet of Things systems, and various other wireless devices including smart building control and so on. Comprising four chapters the monograph explores and provides: The fundamentals of rechargeable batteries, comparison of lithium-ion batteries with other kinds, features of thin-film batteries. A description of functional materials for all-solid-state thin-film batteries. Various methods for applying functional layers of an all-solid-state thin-film lithium-ion battery. Diagnostics of functional layers of all-solid-state thin-film lithium-ion batteries. The monograph is intended for teachers, researchers, advanced undergraduate students, and post-graduate students of profile faculties of universities, as well as for developers and manufacturers of thin-film lithium-ion batteries.