Atomistic simulation techniques represent a powerful complementary tool for studying interfaces. The aim of this presentation is to describe the recent progress in modelling the role of nanostructuring on the properties of energy materials. We begin to address this in our study on the influence of extended defects on the transport properties of two promising candidate oxide energy materials. These include the fluorite-structured CeO2 and the perovskite SrTiO3using a combination of ab initio and potential based techniques. We use DFT to investigate the structure, composition and reactivity and potential based methods to explore configurational space and calculate transport properties such as ionic and thermal conductivity.CeO2is a solid electrolyte in solid oxide fuel cells. Here, we show how grain boundaries affect the oxygen diffusion at the interface and in the region adjacent to the interface at low and high temperatures. Interfacially dominated nano-films can therefore exploit properties not seen in the single crystal and polycrystalline parent materials.SrTiO3 is a thermoelectric material used in thermoelectric devices. We discuss the effect of nanostructuring on suppressing thermal conductivity of SrTiO3 by means of the introduction of grain boundaries. We demonstrate that structural features impact strongly on the mean free path of the phonons and are responsible for the enhanced phonon scattering. The results show that lower densities correlate with lower thermal conductivities due to the increase of extended defects.

Atomistic simulations of extended defects in oxide energy materials

247th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.