Electrolytes with small cations

Kinetics of the electron transfer 3.1.4 Electrolytes with small cations. 390... 

The electrochemical behavior of the crystalline fullerene films is also influenced by the medium. Dissolution of the reduced films is quite important for the films doped with small cations in acetonitrile. It is significantly reduced for large tetraalkylammonium cations or especially so for the polypyridine complex metal cations in acetonitrile, probably because of relatively high polarizability of the aromatic ligands and fullerene anions in the latter case. The extent of dissolution is also a function of the extent of film reduction (see Table 7.9). For solid polymer electrolytes (see refs. [165,167]), the polymer may take part in the... 

A polypyrrole-electrolyte-polypyrrole battery has been described 611) but the n-doped polypyrrole is unstable. This can be avoided by using a polypyrrole-polyanion anode, where the charge and discharge depend upon small cations moving into and out of the electrode612). A polythiophene-polythiophene battery has also been described 135). Polyaniline has been studied as a potential battery cathode, for use with an aqueous electrolyte 613,6I4). 

Xiong, X. and Li, S.F.Y. 1998. Selection and optimization of background electrolytes for simultaneous detection of small cations and organic acids by capillary electrophoresis with indirect photometry. Journal of Chromatography A 822 125-136. 

In particular, the small ionic radius of Ag(r g + = 1.00 A) obviously favors the cation diffusion in a-Agl via migration in the sublattice formed by large 1 anions. However, Na has a comparable size (rNa+ =0.99 A) while Nal is not a solid electrolyte, even at elevated temperature. On the other hand, if the aforementioned requirement of a small ionic radius were crucial, then solid electrolytes with mobile anions would be rather uncommon, as anions are usually larger than cations. As a matter of fact, F and conductors may outnumber cationic conductors thus, the requirements mentioned above are somewhat interdependent, and there is no separate factor which can be used solely to explain fast ionic transport. 

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