Modifying the barriers for oxygen-vacancy migration in fluorite-structured CeO<sub>2</sub>electrolytes through strain: a computer simulation study

Souza, Roger A. De; Ramadan, Amr; Hörner, Stefanie

doi:10.1039/c2ee02508f

Cited by 147 publications

(151 citation statements)

References 55 publications

Supporting

Mentioning

127

Contrasting

Order By: Relevance

“…78 With both isotropic and biaxial strain, signifi cant modifi cation of the energy barriers for oxygen-vacancy migration was found. Their results also suggest that a biaxial tensile strain of 4% increases the in-plane conductivity at T = 500 K by close to four orders of magnitude.…”

Section: Oxide Ion Conduction Under Lattice Strainmentioning

confidence: 99%

“Stretching” the energy landscape of oxides—Effects on electrocatalysis and diffusion

2014

View full text Add to dashboard Cite

show abstract

Section: Oxide Ion Conduction Under Lattice Strainmentioning

confidence: 99%

“Stretching” the energy landscape of oxides—Effects on electrocatalysis and diffusion

2014

View full text Add to dashboard Cite

show abstract

“…As shown in (by works including that of the authors here) to have a significant impact on facilitating oxygen ion transport, [24][25][26][27][28] vacancy formation, [29][30][31][32] and surface adsorption 27, 30 -specific to this paper's scope are the oxygen vacancy formation, oxygen adsorption and oxygen incorporation kinetics on the (La,Sr)CoO 3 films. 27,30,33 La 2 CoO 4+δ has not been a subject of similar studies to date, and we address the potential effects of strain also in this material as part of this paper.…”

Section: Introductionmentioning

confidence: 99%

Mechanism for enhanced oxygen reduction kinetics at the (La,Sr)CoO3−δ/(La,Sr)2CoO4+δ hetero-interface

Han

Yildiz

2012

Energy Environ. Sci.

119

118

View full text Add to dashboard Cite

The recently reported fast oxygen reduction kinetics at the interface of (La,Sr)CoO 3-δ (LSC 113 ) and (La,Sr) 2 CoO 4+δ (LSC 214 ) phases opened up new questions for the potential role of dissimilar interfaces in advanced cathodes for solid oxide fuel cells (SOFCs). Using first-principles based calculations in the framework of density functional theory, we quantitatively probed the possible mechanisms that govern the oxygen reduction activity enhancement at this hetero-interface as a model system. Our findings show that both the strongly anisotropic oxygen incorporation kinetics on the LSC 214 and the lattice strain in the vicinity of the interface are important contributors to such enhancement. The LSC 214 (100) surface exposed to the ambient at the LSC 113 /LSC 214 interface facilitates oxygen incorporation because the oxygen molecules very favorably adsorb on it compared to the LSC 214 (001) and LSC 113 (001) surfaces, providing a large source term for oxygen incorporation. Lattice strain field present near the hetero-interface accelerates oxygen incorporation kinetics especially on LSC 113 (001). At 500 °C 4×10 2 times faster oxygen incorporation kinetics is predicted in the vicinity of the LSC 113 /LSC 214 heterointerface with 50% Sr-doped LSC 214 compared to that on the single phase LSC 113 (001) surface.Contributions from both the anisotropy and local strain effects are of comparable magnitude. The insights obtained in this work suggest that hetero-structures which have a large area of (100) surfaces and smaller thickness in [001] direction of the Ruddlesden-Popper phases, and larger tensile strain near the interface would be promising for high-performance cathodes.Keywords: solid oxide fuel cell, oxygen reduction reaction, cathode, anisotropy, strain, perovskite, Ruddlesden-Popper, (La,Sr)CoO 3 , (La,Sr) 2 CoO 4+δ , density functional theory * Corresponding author. Email: byildiz@mit.edu 2 Graphical AbstractAnisotropic oxygen incorporation on (La,Sr) 2 CoO 4+δ and the lattice strain near the (La,Sr)CoO 3-δ / (La,Sr) 2 CoO 4+δ interface serve as two possible sources to accelerate the oxygen reduction kinetics on the hetero-structure by 4×10 2 times at 500 °C. Broader contextHigh efficiency and fuel flexibility of Solid Oxide Fuel Cells (SOFCs) render them attractive as a sustainable energy conversion technology. There is growing interest in the design of dissimilar interfaces at the nano-scale to enable high-performance SOFC cathodes with fast oxygen reduction reaction (ORR) kinetics at lower temperatures than their traditional operation temperature of 800 °C. A motivating example for this purpose has been the hetero-structure made of the (La,Sr)CoO 3-δ and (La,Sr) 2 CoO 4+δ phases with highly active interfaces. Two previous experimental reports have observed 10 3 -10 4 times enhancement in ORR kinetics at 500-550 °C arising from the interface of these two phases. However, these empirical observationshave not yet reached a fundamental understanding of why these interfaces are so highly active...

show abstract

“…Strain fields can be introduced (a) locally via doping with isovalent atoms or (b) by the formation of heterostructures resulting in epitaxial strain fields mainly near the interface between the layers of the dissimilar materials [30][31][32]. Interestingly, the work of Garcia-Barriocanal et al [33] determined up to an eight order-of-magnitude increase in conductivity for epitaxially-grown zirconia/strontium titanate heterostructures and this motivated the community [26,34]. To clarify this unprecedented result, numerous atomistic simulation studies were employed given that in these it is easier to employ and control strain as compared to the experiment [26,34].…”

Section: Doping and Strain Strategiesmentioning

confidence: 99%

“…Interestingly, the work of Garcia-Barriocanal et al [33] determined up to an eight order-of-magnitude increase in conductivity for epitaxially-grown zirconia/strontium titanate heterostructures and this motivated the community [26,34]. To clarify this unprecedented result, numerous atomistic simulation studies were employed given that in these it is easier to employ and control strain as compared to the experiment [26,34]. At any rate, the accuracy of molecular dynamics simulations to describe oxygen diffusion in doped ceria will depend upon the potential model that should appropriately describe the thermal expansion of doped CeO 2 .…”

Section: Doping and Strain Strategiesmentioning

confidence: 99%

Toward Defect Engineering Strategies to Optimize Energy and Electronic Materials

et al. 2017

View full text Add to dashboard Cite

Abstract:The technological requirement to optimize materials for energy and electronic materials has led to the use of defect engineering strategies. These strategies take advantage of the impact of composition, disorder, structure, and mechanical strain on the material properties. In the present review, we highlight key strategies presently employed or considered to tune the properties of energy and electronic materials. We consider examples from electronic materials (silicon and germanium), photocatalysis (titanium oxide), solid oxide fuel cells (cerium oxide), and nuclear materials (nanocomposites).

show abstract

Modifying the barriers for oxygen-vacancy migration in fluorite-structured CeO₂electrolytes through strain: a computer simulation study

Cited by 147 publications

References 55 publications

“Stretching” the energy landscape of oxides—Effects on electrocatalysis and diffusion

“Stretching” the energy landscape of oxides—Effects on electrocatalysis and diffusion

Mechanism for enhanced oxygen reduction kinetics at the (La,Sr)CoO3−δ/(La,Sr)2CoO4+δ hetero-interface

Toward Defect Engineering Strategies to Optimize Energy and Electronic Materials

Contact Info

Product

Resources

About

Modifying the barriers for oxygen-vacancy migration in fluorite-structured CeO2electrolytes through strain: a computer simulation study

Cited by 147 publications

References 55 publications

“Stretching” the energy landscape of oxides—Effects on electrocatalysis and diffusion

“Stretching” the energy landscape of oxides—Effects on electrocatalysis and diffusion

Mechanism for enhanced oxygen reduction kinetics at the (La,Sr)CoO3−δ/(La,Sr)2CoO4+δ hetero-interface

Toward Defect Engineering Strategies to Optimize Energy and Electronic Materials

Contact Info

Product

Resources

About

Modifying the barriers for oxygen-vacancy migration in fluorite-structured CeO₂electrolytes through strain: a computer simulation study