This book reports a study of a class of Dion–Jacobson-type layered perovskite oxides in which high oxide-ion conductivities in phases were discovered for the first time in the world. The oxide-ion conductors are important in various energy conversion devices and environmental protection applications such as solid-oxide fuel cells, oxygen gas sensors, oxygen separation membranes, and oxygen-based catalysts. The discoveries are based on a new screening method, called the bond valence method, combined with an original design concept. The present finding of high oxide-ion conductivity reported in the thesis suggested the potential of Dion–Jacobson phases as a platform to identify superior oxide-ion conductors.
To understand what causes such high oxide-ion conductivities in these layered perovskite oxides, the author analyzed their crystal structures at high temperature and described the relationship between oxide-ion conductivities and their crystal structures. A deep understanding of the mechanisms of oxide-ion diffusivity at an atomic level in the Dion–Jacobson phases is clarified.
The discovery of these materials, the new screening method, and the original design concept make possible the realization of many environment-friendly technologies. The findings in this thesis facilitate the possibilities for many novel applications that will help lead to a sustainable future.
Author(s): Wenrui Zhang
Series: Springer Theses
Publisher: Springer
Year: 2022
Language: English
Pages: 134
City: Singapore
Supervisor’s Foreword
Acknowledgements
Contents
1 Introduction
1.1 Background
1.1.1 Energy and the Environment
1.1.2 Oxide-Ion Conductor
1.1.3 Perovskite and Perovskite-Related Oxides
1.2 Previous Studies
1.2.1 Oxide-Ion Conduction in Perovskite or Perovskite-Related Structures
1.2.2 Properties of Dion–Jacobson-Type Layered Perovskites
1.3 Crystal Structure Analysis
1.3.1 Synchrotron X-ray Powder Diffraction
1.3.2 High-Temperature Synchrotron X-ray Powder Diffraction
1.3.3 Neutron Diffraction
1.3.4 High-Temperature Neutron Diffraction
1.3.5 Rietveld Refinement
1.4 Electrical Properties Measurement
1.4.1 Temperature Dependence of Total Electrical Conductivities
1.4.2 The Oxygen Partial Pressure Dependence of Total Electrical Conductivities
1.4.3 Oxygen Concentration Cell Measurements
1.4.4 Impedance Spectroscopy Measurements
1.5 Bond-Valence-Based Energy Calculation
1.6 Maximum-Entropy Method Analysis
1.7 Density Functional Theory Calculation
References
2 New Oxide-Ion Conductors of Dion–Jacobson-Type Layered Perovskites CsBi2Ti2NbO10-δ
2.1 Introduction
2.2 Experimental Section
2.2.1 Synthesis and Characterization
2.2.2 Electrical Conductivity Measurements
2.2.3 Neutron and Synchrotron X-ray Diffraction Measurements
2.2.4 Bond-Valence-Based Energy Calculation
2.2.5 Maximum-Entropy Method Analysis
2.2.6 Oxygen Concentration-Cell Measurements
2.2.7 Improved Oxide-Ion Conductivity by Doping
2.3 Results and Discussion
2.4 Conclusion
2.5 Outlook
References
3 New Oxide-Ion Conductors of Dion–Jacobson-Type Layered Perovskites CsLn2Ti2NbO10 (Ln = La, Pr, Nd, Sm, Gd, Ho, and Yb) and CsLa2–xMxTi2+yNb1–yO10–x/2–y/2 (M = Ca, Sr, and Ba; x = 0, 0.1; y = 0.1, 0, and –0.1)
3.1 Introduction
3.2 Experimental
3.2.1 Synthesis and Characterization
3.2.2 Electrical Conductivity Measurements
3.2.3 Neutron and Synchrotron X-ray Diffraction Measurements
3.2.4 Density Functional Theory Calculation
3.2.5 Investigation of Oxide-Ion Diffusion Pathways
3.2.6 Improved Oxide-Ion Conductivity by Doping
3.3 Results and Discussion
3.4 Conclusion
References
4 Conclusion and Future Work
