Molecular dynamics simulation of the complex dopant effect on the super-ionic conduction and microstructure of zirconia-based solid electrolytes

The complex dopant effect on the super-ionic conduction and structural stability of zirconia-based solid electrolyte for solid oxide fuel cell (SOFC) applications was investigated using the molecular dynamics (MD) technique. Various components of Sc2O3(x)-Y2O3(1-x) were added to the cubic zirconia cell to build a scandia-yttria-stabilized zirconia (Sc-Y-SZ) model. The oxygen ion diffusion mechanism and ionic conductivity obtained by MD simulation were examined to gain insight into how the performance was improved by adding different Sc2O3 concentrations. The radial distribution function (RDF) of the O-O pair was determined to analyze the oxygen ion mobility using microstructure analysis. The mean-square displacement (MSD) of the cations and RDF of the Zr-Zr pair were investigated to determine how the structural stability was affected by the concentration of doped Sc2O3. The simulated results were in agreement with the experimental data reported in the literature, suggesting that MD simulation is a feasible technique for use in the material design and development of SOFC applications. (C) 2009 Elsevier B.V. All rights reserved.