Recent Progress in Interfacial Nanoarchitectonics in Solid-State Batteries

Employing solid electrolytes in lithium-ion batteries is anticipated to be a solution to some issues originated from their organic electrolytes. However, solid-state lithium batteries had not been practicable, because ionic conductivities of lithium-ion conductive solid electrolytes had been very low. Therefore, many studies aiming at the development of solid-state lithium batteries have been focused on enhancement of ionic transport in solids. They have succeeded in enhancing the conductivity to be comparable to or even higher than that of liquids. At this stage, rate-determining step of the battery reactions is sometimes ionic transport at interface rather than bulk in the battery components. Since anomalous ionic conduction at the interface takes place in space-charge layers with ca. 10 nm in thickness, it will be controlled by "nanoarchitectonics". This paper reviews some interfacial nanoarchitectures that control the interfacial ionic conduction to enhance the performance of solid-state lithium batteries.