(Invited) Theoretical Approach for Understanding Oxygen Reduction at the Cathode Surface of Solid Oxide Fuel Cell
As an extension of our preceding studies, we will discuss how the electronic structure affects the surface kinetics in this study. We adopted the La0.5Sr0.5O3-δ as cathode material and prepared the (001) surface model with the LaO termination. The model consists of five layers with the total 48 atoms. For the electronic structure calculations, we used Vienna Ab initio Simulation Package (VASP) based on the density functional theory. U parameter is adopted as correction for electronic correlation calculation. We investigated the oxygen adsorption energy, vacancy formation energy and oxygen dissociation energy by changing the spin states of Co in La0.5Sr0.5O3-δ. We observed dependency of the calculated energies and the spin states. Based on the calculated properties, we will discuss the kinetic process of oxygen reduction at La0.5Sr0.5O3-δ surface together with the perspectives of future analysis.
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The activities of INAMORI Frontier Research Center is supported by KYOCERA Corporation.