Premium
Designing Optimal Perovskite Structure for High Ionic Conduction
Author(s) -
Gao Ran,
Jain Abhinav C. P.,
Pandya Shishir,
Dong Yongqi,
Yuan Yakun,
Zhou Hua,
Dedon Liv R.,
Thoréton Vincent,
Saremi Sahar,
Xu Ruijuan,
Luo Aileen,
Chen Ting,
Gopalan Venkatraman,
Ertekin Elif,
Kilner John,
Ishihara Tatsumi,
Perry Nicola H.,
Trinkle Dallas R.,
Martin Lane W.
Publication year - 2020
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201905178
Subject(s) - materials science , ionic conductivity , perovskite (structure) , conductivity , ionic bonding , octahedron , rietveld refinement , chemical physics , electrolyte , crystallography , ion , crystal structure , chemistry , organic chemistry , electrode
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 La 0.9 Sr 0.1 Ga 0.95 Mg 0.05 O 3– 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.