Published online by Cambridge University Press: 15 February 2011
Stannous fluoride SnF2 and mixed fluorides containing divalent tin are the highest performance fluoride ion conductors known to date. Since the fluoride ion mobility increases with temperature, and that these materials are sensitive to hydrolysis of the Sn-F bonds and oxidation of tin(II) to tin(IV) when heated, there is a significant chance of material degradation on heating. Surface oxidation provides a thin coating of highly refractory Sn02, which passivates against further degradation. The details and limits of this protection in SnF2 have been studied and are presented here.