Glassy-ion conductors

Various theoretical attempts have been made to provide a quantitative interpretation of the dispersion region (Funke, 1986 Funke and Hoppe, 1990). While the situation is still not fully resolved, it is now clear that such a dispersion, which has been observed in a wide range of crystalline as well as glassy ionic conductors, is associated with ion-ion relaxation effects. The conductivity dispersion, ff(co), is usually linear in a plot of log a vs log CO, which means that it can be represented by a power law expression ... 

At this time the only commercially available all-solid-state cell is the lithium battery containing Lil as the electrolyte. Many types of solid lithium ion conductors including inorganic crystalline and glassy materials as well as polymer electrolytes have been proposed as separators in lithium batteries. These are described in the previous chapters. A suitable solid electrolyte for lithium batteries should have the properties... 

Typical volume conductivities of rubbers are around 10 -10 Qcm. The electric conductivity of rubber is caused by the presence of impurities which transfer ions and thus electric current. On transition from glassy to elastic state voltrme resistivity decreases by several orders of magnitude because of an increase in ion mobihty. Also plasticization of mbbers decreases their volume resistivity because of the increased ion mobility. Classification of various rubbers according to their electrical conductivity was published elsewhere. As data in Table 10.6 show, polymers are excellent electrical insulators but they can be modified to become good conductors having volume resistance of 10 Qcm or less. ... 

There are numerous publications concerning the theory and applications of superionic conduction(see also the Preface). Table 3.1 gives the main electrical parameters of some typical superionic conductors. Superionic conductivity has been observed for a number of ions, Ag", Li+, Na+, K+, Cu+, Pb +, F", O ", NH4+, H+(H20) the lowest , has been found in Agl-based materials. Some compounds exhibit both high ionic and electronic conductivity. Glassy materials are usually poorer conductors and have higher activation energy than crystalline materials of similar composition. 

Apart from crystalline phases, various glassy solid F conductors have also been developed. A glass in the ZrF4-BaF2 system, the first example of such conductors, exhibits a conductivity of 10" S cm" at 200°C.2 Extensive studies have been performed with this system, including short-range stractural analyses, T NMR, simulation based on molecular dynamics, etc. According to the results, there are basically two kinds of fluorine ions, i.e., a... 

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