Publisher Summary Ceramic materials play an important role in the field of battery technology. The Li-ion battery is a typical case in which ceramic materials are applied. In Li-ion batteries, lithium oxides are used for positive active material and carbons for negative active material. Both of the active materials are considered ceramics prepared by normal ceramic-production processes. They are used in powder form in Li-ion batteries. Typical cylindrical cell structure and electrode configuration of Li-ion battery are illustrated. When Li ions are intercalated to graphite, the Li ions penetrate not into the basal plane, but into the edge plane of the graphite crystal structure. Battery reaction of Li-ion battery is given. The production process of Li-ion battery is illustrated. Compared to conventional batteries such as lead-acid, Ni-Cd, and Ni-MH, Li-ion batteries provide higher energy density and higher power density.