Designing Optimal Perovskite Structure for High Ionic Conduction

ORAL

Abstract

There has been an incomplete understanding of the structure-property relationships that would enable the rational design of better ion-conducting electrolytes for SOFC. Here, using epitaxial thin-film growth, synchrotron X-ray diffraction, impedance spectroscopy, and density-functional theory, we delineate the impact of structural parameters (i.e., unit-cell volume and octahedral rotations) on ionic conductivity 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 we experimentally realize both expanded unit-cell volume and strong octahedral rotations which result in an enhancement of the ionic conductivity by ~250% at around 600°C.

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Presenters

  • Ran Gao

    Materials Science and Engineering, University of California, Berkeley

Authors

  • Ran Gao

    Materials Science and Engineering, University of California, Berkeley

  • Abhinav Jain

    Materials Science and Engineering, University of Illinois, Urbana-Champaign

  • Shishir Pandya

    Materials Science and Engineering, University of California, Berkeley

  • Yongqi Dong

    University of Science and Technology of China, X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne National Laboratory

  • Yakun Yuan

    Materials Science and Engineering, Pennsylvania State University, Pennsylvania State University

  • Hua Zhou

    Advanced Photon Source, Argonne National Laboratory, X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne National Lab, Argonne National Laboratory

  • Liv R Dedon

    Materials Science and Engineering, University of California, Berkeley

  • Vincent Thoréton

    WPI International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University

  • Sahar Saremi

    University of California, Berkeley, Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA., Materials Science and Engineering, University of California, Berkeley, Department of Materials Science and Engineering, University of California, Berkeley

  • Ruiijuan Xu

    Materials Science and Engineering, University of California, Berkeley

  • Aileen Luo

    Materials Science and Engineering, University of California, Berkeley

  • Ting Chen

    WPI International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University

  • Venkatraman Gopalan

    Pennsylvania State University, Materials Science and Engineering, Pennsylvania State University, Physics, Pennsylvania State University, Materials Science and Engineering Department, Pennsylvania State University

  • Elif Ertekin

    University of Illinois at Urbana-Champaign, Mechanical Science and Engineering, University of Illinois, Urbana-Champaign

  • John Kilner

    WPI International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University

  • Tatsumi Ishihara

    WPI International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University

  • Nicola Perry

    Materials Science and Engineering, University of Illinois, Urbana-Champaign

  • Dallas Trinkle

    Materials Science and Engineering, University of Illinois, Urbana-Champaign

  • Lane Martin

    Department of Materials Science & Engineering, University of California, Berkeley, University of California, Berkeley, Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA., Materials Science and Engineering, University of California, Berkeley, University of Illinois at Urbana-Champaign