Designing Optimal Perovskite Structure for High Ionic Conduction
Abstract
Solid‐oxide fuel/electrolyzer cells are limited by a dearth of electrolyte materials with low ohmic loss and an incomplete understanding of the structure–property relationships that would enable the rational design of better materials. Here, using epitaxial thin‐film growth, synchrotron radiation, impedance spectroscopy, and density‐functional theory, the impact of structural parameters (i.e., unit‐cell volume and octahedral rotations) on ionic conductivity is delineated in La0.9Sr0.1Ga0.95Mg0.05O3–δ. As compared to the zero‐strain state, compressive strain reduces the unit‐cell volume while maintaining large octahedral rotations, resulting in a strong reduction of ionic conductivity, while tensile strain increases the unit‐cell volume while quenching octahedral rotations, resulting in a negligible effect on the ionic conductivity. Calculations reveal that larger unit‐cell volumes and octahedral rotations decrease migration barriers and create low‐energy migration pathways, respectively. The desired combination of large unit‐cell volume and octahedral rotations is normally contraindicated, but through the creation of superlattice structures both expanded unit‐cell volume and large octahedral rotations are experimentally realized, which result in an enhancement of the ionic conductivity. All told, the potential to tune ionic conductivity with structure alone by a factor of ≈2.5 at around 600 °C is observed, which sheds new light on the rational design of ion‐conducting perovskite electrolytes.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 04, 2019
- Source ID
- 10.1002/adma.201905178
Entities
People
- Abhinav C. P. Jain
- Aileen Luo
- Dallas R. Trinkle
- Elif Ertekin
- Hua Zhou
- John Kilner
- Lane W Martin
- Liv R. Dedon
- Nicola H Perry
- Ran Gao
- Ruijuan Xu
- Sahar Saremi
- Shishir Pandya
- Tatsumi Ishihara
- Ting Chen
- Venkatraman Gopalan
- Vincent Thoreton
- Yakun Yuan
- Yongqi Dong
Organizations
- Argonne National Laboratory
- Army Research Office
- Imperial College London
- International Institute for Carbon-Neutral Energy Research, Kyushu University
- Kyushu University
- Lawrence Berkeley National Laboratory
- Ministry of Education, Culture, Sports, Science and Technology
- National Science Foundation
- Office of Basic Energy Sciences
- Office of Science
- Pennsylvania State University
- United States Department of Energy
- University of California
- University of Illinois Urbana–Champaign
- University of Science and Technology of China