Recent Developments in Oxide-Based Ionic Conductors: Bulk Materials, Nanoionics, and Their Memory Applications

Oxide-based ionic conductors have attracted tremendous research interests due to their wide applications in energy storage and conversion devices, such as photovoltaics, fuel cells, batteries, and supercapacitors. Extensive efforts have been undertaken to improve the ionic conductivity of existing materials along with the development of novel conductors. The recent advance of ionic conductors in nanoscale demonstrated their ultra–high ionic conductivity for the promising applications in energy sector. In this work, recent progresses of conventional oxide conductors and the development of novel conductors are reviewed in details. The strategy to exploit the nanoionics of enhancing the ionic conductivity is discussed. Furthermore, the novel applications of nanoionics for the resistive switching memories are summarized.