title: Solid State Ionics: from Michael Faraday to green energy-the European dimension.
abstract: Solid State Ionics has its roots essentially in Europe. First foundations were laid by Michael Faraday who discovered the solid electrolytes Ag2S and PbF2and coined terms such ascationandanion,electrodeandelectrolyte. In the 19th and early 20th centuries, the main lines of development toward Solid State Ionics, pursued in Europe, concerned the linear laws of transport, structural analysis, disorder and entropy and the electrochemical storage and conversion of energy. Fundamental contributions were then made by Walther Nernst, who derived the Nernst equation and detected ionic conduction in heterovalently doped zirconia, which he utilized in his Nernst lamp. Another big step forward was the discovery of the extraordinary properties of alpha silver iodide in 1914. In the late 1920s and early 1930s, the concept of point defects was established by Yakov Il'ich Frenkel, Walter Schottky and Carl Wagner, including the development of point-defect thermodynamics by Schottky and Wagner. In terms of point defects, ionic (and electronic) transport in ionic crystals became easy to visualize. In an 'evolving scheme of materials science', point disorder precedes structural disorder, as displayed by the AgI-type solid electrolytes (and other ionic crystals), by ion-conducting glasses, polymer electrolytes and nano-composites. During the last few decades, much progress has been made in finding and investigating novel solid electrolytes and in using them for the preservation of our environment, in particular in advanced solid state battery systems, fuel cells and sensors. Since 1972, international conferences have been held in the field of Solid State Ionics, and the International Society for Solid State Ionics was founded at one of them, held at Garmisch-Partenkirchen, Germany, in 1987.
authors.affiliation: University of Münster, Institute of Physical Chemistry, Corrensstraße 30, D-48149 Münster, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Funke
keywords: 10.03; 10.10; 10.13; Nernst equation; Solid State Ionics; disorder; electrochemistry; energy conversion; energy storage; entropy; environment; fuel cells; glasses; history; ionic conduction; ionic crystals; laws of transport; lines of development; nanoionics; point defects; polymers; sensors; solid electrolytes; solid state battery sytems; structural analysis