Ionic and mixed conductors for electrochemical devices

The contribution gives a brief overview on the use of ionic and mixed conductors for electrochemical devices such as fuel cells, batteries, sensors, permeation membranes or electrochemical windows. Special emphasis is laid on the understanding of thermodynamics and kinetics of charge carrier concentration and mobilities, in particular on the dependence of the properties on the control parameters. A second part of the contribution is devoted to the use of this knowledge to optimise electrochemical properties and devices. In this context the introduction of interfaces and the use of the spacing of interfaces as practical "degrees of freedom" are discussed with regard to future applications.