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.

*NSF Grant OISE-1545907

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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