Effect of morphology and particle size on the ionic conductivities of composite solid electrolytes

A model incorporating the surface conductivity and morphology of the composite solid electrolytes is envisaged to explain their conduction behaviour. The conductivity data on LinX−50 m/o Al2O3 (X = F−, Cl−, Br−, CO32−, SO42−, PO43−) composites prepared by thermal decomposition of LinX·2nAl(OH)3·mH2O salts and Li2SO4−A (A=Al2O3, CeO2, Y2O3, Yb2O3, Zr2O3, ZrO2 and BaTiO3) composites prepared by mechanical mixing of the components are examined in the light of this model. It is surmised that the particle size of both the dispersoids and the hosts not only influence the ionic conductivity of the host matrix but also affect its bulk properties

Ion transport in dual-phase SrFe1-xD cent D degrees O-x(3-delta) (x=0.03-aEuro parts per thousand 0.10): effects of redox cycling

The incorporation of tantalum cations in mixed-conducting SrFe1-xTaxO3-delta (x = 0.03 -aEuro parts per thousand 0.10) results in the formation of single cubic perovskite-like phases in oxidizing atmospheres while under reducing conditions phase separation is observed, accompanied with an appearance of brownmillerite-type nanodomains on the background of the perovskite-like matrix. For SrFe0.97Ta0.03O3-delta after reduction, the x-ray and electron diffraction studies combined with transmission electron microscopy evidence the formation of approximately 30 vol.% brownmillerite phase with an average domain size of 20-40 nm. The oxygen partial pressure dependencies of the total conductivity in the range from 10(-20) to 0.5 atm at 700-950 A degrees C show that the electron transport parameters remain virtually independent on the dopant content and domain structure. Contrary to the materials with higher dopant content, however, the ion conduction in SrFe0.97Ta0.03O3-delta tends to substantially increase on redox cycling. This behavior was attributed to the brownmillerite domain disintegration and rearrangement, induced by cyclic formation and disappearance of oxygen vacancies