Fast ionic conductors

Abstract This article is a general introduction to the scientific and technological aspects of fast ionically conducting materials, illustrated by three classes of material which are based on silver iodide, sodium beta-alumina and stabilized zirconia respectively. The possibility of predicting new ones is discussed with particular emphasis on crystal structure considerations. Some new proton conductors are mentioned and the section concludes with a discussion of the methods and problems associated with material characterization. A description of the basic physics of a solid electrolyte based electrochemical cell is followed by a detailed assessment of oxygen concentration cells, fuel cells, electrolysers and batteries, and also some comment on the problems encountered in the transfer of science to technology. The review ends with a description of various, more recent, device applications of fast ionic conductors which include a thermoelectric generator, various electronic components and solid state displays.