Oxygen surface exchange and diffusion in fast ionic conductors

The rate of oxygen surface exchange on selected bulk oxides exhibiting enhanced oxygen ion conductivity has been derived by measuring 18O penetration profiles using a high sensitivity dynamic SIMS technique. These values for the oxygen surface exchange coefficient (K) were used to derive the steady-state oxygen fluxes through the oxide surface for conditions when the bulk oxide was in equilibrium with 1 atm. of oxygen at 500 and 700°C. The oxygen fluxes were transformed into current fluxes and compared with available exchange current densities (iO) measured using electrochemical techniques. The two sets of current densities exhibited large differences for zirconia based electrolytes which confirmed the important role of platinum as an electro-catalyst. However for bismuth based electrolytes good agreement was noted between the two sets of iO values. It was concluded therefore that the dissociative adsorption of oxygen occurred predominately on the surface of the Bi2O3 based electrolyte and that the presence of a metal electrode (Pt or Au) had little effect upon the overall exchange current kinetics

Diario constitucional de Barcelona: Número 31 - 1820 abril 12

Green Energy and Technology55181-12

Mixed Oxygen Ion and Proton Conduction in BaZr 0.85Y 0.15O3-δ

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Oxygen ion diffusion and surface exchange properties of the ?- And ?-phases of Bi2O3

10.1002/aenm.201301575Advanced Energy Materials410130157

Genetics of superionic conductivity in lithium lanthanum titanates

Using a genetic algorithm in conjunction with molecular dynamics we describe diffusion mechanisms and provide evidence that there is a 3D percolated network of Li diffusion pathways in La2/3−xLi3xTiO3.</p