Silver Ion Conduction

Groger, The Chemistry of Imperfect Crystals, North Holland, Amsterdam (1964) 

Galasso, Structure, Properties and Preparation of Perovskite Type Compounds, Pergamon Press (1969) 

Muller-Bushbaum, J. Less Common Metals 15, 771 (1990) 

Goodenough, J.E. Ruiz-Diaz, Y.S. Zhen, Solid State Ionics 44, 21 (1990) 

Iwahara, T. Esaka, H. Uchida, N. Maeda, Solid State Ionics 3/4, 359 (1981) 

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In the closely related compound AgCuS, the sulfur atoms form a slightly distorted hexagonal close-packed array. The Cu+ ions are located in positions within this framework to form layers, while the Ag+ ions lie between the sulfur-copper layers. These Ag+ ions show a progressively greater anisotropic thermal motion as the temperature rises, until, above 93°C, they are essentially completely mobile, leading to extremely high silver ion conductivity. 

One largely investigated system in the field of silver ion conductivity is the Rbl-AgI system, including the fast ionic conductor, RbAgJj [19,28,29], Structural investigations of these compounds started 40 years ago and the field has been active during the last four decades. The mechanism of conduction and the favored conduction pathway in ionic conductors is important for the development of solid-state batteries [28],... 

The chief restriction of these mixed-salt electrodes is that the solubility of the second salt must be much larger than that of Ag2S but, on the other hand, it must be sufficiently insoluble that its dissolution does not limit to relatively high values the test ion concentration that can be detected. As long as the membrane contains sufficient silver sulfide to provide silver ion conducting pathways through the membrane, it will function as a silver electrode. The potential, then, is related... 

Fig. 27.4. A Hittorf experiment on soKd electrolytes as proposed by Tubant. A silver salt is used as an example. The electrolyte is divided into three parts and placed between silver electrodes. Full lines, size before electrolysis. Broken lines, size after electrolysis. Cross hatched area, gain during electrolysis. Only silver ion conduction is assumed in (a) while additional anion conduction is assumed in (b).

One of the first solid electrolytes exhibiting a very high ionic conductivity, found in 1914, is a-Agl. This conducting o -phase is stable above 149°C and its high conductivity is caused by structural disorder. A similar disorder exists in RbAg4l5. This solid electrolyte exhibits the highest silver ion conductivity at room temperature at present. Therefore, it is of great technical interest. A... 

Silver iodide, Agl, adopts the wurtzite-type stmcture at room temperature. This P form of Agl transforms into the a form (bcc) at 147°C with a jump of conductivity over more than 3 orders of magnitude, as given in Figure 6.5. The silver ion conductivity after the transformation is 1 S cm which is almost the same as that of the molten phase (m.p. 552°C) and even comparable to an H2SO4 solution. Cuprous iodide, Cul, undergoes a similar... 

Sato, M., Toda, K., Watanabe, J., Uematsu, K. Structure determination and silver ion conductivity of layered perovskite compounds M2La2Ti30io (M = K and Ag). J. 

In contrast to the liquid membrane electrodes, the selectivity coefficients of the exclusively fluoride or silver ion-conducting solid membrane electrodes are clearly determined by the ratio of the corresponding solubility products, and are thus independent of the respective electrode manufacturers. 

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