Super ionic conductors

Optimization of all of these categories of materials has produced solids in which the ionic conductivity is as large as that normally found in solutions (Fig. 6.1). Such materials are sometimes called super-ionic conductors, but the terms fast ion conductors or solid electrolytes are to be preferred to avoid confusion with metallic superconductors, which transport electrons and holes, not ions, and by a quite different mechanism. 

Monophosphate tungsten bronzes with pentagonal tunnels NASICON = Sodium super ionic conductor NLO = Nonlinear Optical PLZT = Lead lanthanum zirconium titanate PZT = Lead zirconium titanate SBT = Strontium Bismuth Tantalate, SrBi2Ta209 SOFC = Solid oxide fuel cell TTB = Tetragonal tungsten bronze YAG = Yttrium iron garnet 3D = Three-dimensional TEOS = Tetraethylorthosilicate. 

Mahan GD, Roth WL (eds) (1976) Super ionic conductors. Plenum, New York... 

Different defects in solids will be described and some examples of super ionic conductors presented. 

These substances have more sites then ions. This led to high conductivity values, which led to the name super ionic conductors. The disorder can concern the cation lattice (cation conductors) or the anion lattice (anion conductors). The transfer numbers t+ and t determine the classification with 1 for cation conductors or t 1 for anion conductors. Because of the usually small size of the cation compared to the anions, cation conductors are dominant. 

With the development of lithium batteries, lithium conducting solid electrolytes were intensively investigated. The representative compound is LijN. Another super ionic conductor is LijP while LijAs shows metallic conductivity. Other Li ions conducting solid... 

Nasicon (Natrium Super Ionic Conductor) is a ceramic materiai abie to conduct via Na ions at room temperature. 

Ceramics, like NASICON (sodium super ionic conductor) prepared by the sol-gel method, were found to give selective potentiometric response toward various cations. Selectivity is provided by the... 

It is the purpose of this paper to suggest a simple model for the metal-super ionic conductor interphase which can explain some of the experimental observations which have been made on these systems. The model is essentially a refinement of one discussed earlier (1). Super ionic conductors are taken to be (typically) sodium 3 Al203 and Agi+Rbl5, i.e. solids which have very high ionic conductivities (up to 10 0. cm" ), negligible electronic conductivities and very high concentrations of mobile species ( 10 mol 1" ). In what follows it will be assumed initially that the solid consists of immobile anions and cations which are all equivalent and all mobile. 

A simple model for the interphase between metals and super ionic conductors such as Agi+Rbl5 is proposed. 

Besides the described disorder in some solids, there are more places than ions or the ions can occupy different sites. Such compotmds like a-Agl or 8-Bi203 are called as super ionic conductors (see entry Solid Electrolytes ), and this disorder is described as structural disorder. Sometimes, it was distinguished between... 

Solid electrolytes based on chemical disorder Solid electrolytes based oti structural disorder (super-ionic conductors)... 

If there are more places in the lattice than mobile ions, the ions can occupy different lattice sites. Such solids are called super-ionic conductors. In this classification, in turn, it is distinguished between those solid electrolytes which exhibit that structure above the temperature of a phase transition (sometimes called as type I) and those which show that behavior over the whole temperature range (type II). As examples for the Type I, a-AgI and 8-Bi203 are mentioned, which are formed after the phase transitions ... 

UPON lithium phosphorus oxynitride, NASICON sodium super-ionic conductor Source Data from Park et al. (2003), Iwahara (2009), etc. 

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