COMPOSITE PROTONIC SOLID ELECTROLYTES IN THE CSHSO4-SIO2 SYSTEM

Transport, thermal and structural properties of the composite solid el ectrolytes (1 - x)CsHSO4-xSiO(2) (where x = 0-0.8) were investigated. The composites were prepared by mechanical mixing of components follow ed by heating at temperatures near CsHSO4 melting point (483 K). The d ependence of low temperature phase conductivity on x has a maximum wit h a value 2.5 orders of magnitude higher than that of pure CsHSO4 and conductivity is governed by protons. Heterogeneous doping is shown to change markedly the thermodynamic parameters of the ionic component. T he phase transition temperature CsHSO4 in the composites decreases fro m 414 to 350 K with the increase of the content of heterogeneous addit ive SiO2 from 0 to 0.7. As x raises CsHSO, the amorphization takes pla ce and the relative change of ionic conductivity at phase transition d iminishes, the phase transition becomes diffusive and disappears for t he 0.2CsHSO(4)-0.8SiO(2) composite.