Title: Density-Functional-Theory Modeling of Cation Diffusion in Bulk ${\mathrm{La}}_{1-x}{\mathrm{Sr}}_x{\mathrm{MnO}}_{3\pm \delta }$ ( $x=0.0–0.25$ ) for Solid-Oxide Fuel-Cell Cathodes

Abstract

In this work, the A - and B -site cation migration pathways involving defect complexes in bulk La _1-xSr _xMnO _3±δ (LSM) at x = 0.0-0.25 are investigated based on density-functional-theory modeling for solid-oxide fuel-cell (SOFC) cathode applications. We propose a dominant A -site cation migration mechanism which involves an A -site cation (e.g., La$$x\atop{A}$$) V _A"' of a V _A"' -V _B"' cluster, where La$$x\atop{A}$$, V _A"' and V _B"' are La ³⁺, A-site vacancy, and B-site vacancy in bulk LSM, respectively, and V _A"' -V _B"' is the first nearest-neighbor V _A"' and V _B"' pair. This hop exhibits an approximately 1.6-eV migration barrier as compared to approximately 2.9 eV of the La$$x\atop{A}$$ hop into a V _A"'. This decrease in the cation migration barrier is attributed to the presence of the V _B"' relieving the electrostatic repulsion and steric constraints to the migrating A-site cations in the transition-state image configurations.

Authors:

Lee, Yueh-Lin ^[1]; Duan, Yuhua ^[1]; Morgan, Dane ^[2]; Sorescu, Dan C. ^[1]; Abernathy, Harry ^[3]; Hackett, Gregory ^[4]

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+ Show Author Affiliations

1. National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)
2. National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Univ. of Wisconsin, Madison, WI (United States). Dept. of Materials Science and Engineering
3. National Energy Technology Lab. (NETL), Morgantown, WV (United States); AECOM, Morgantown, WV (United States)
4. National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); National Energy Technology Lab. (NETL), Morgantown, WV (United States)

Publication Date:

2017-10-04

Research Org.:

National Energy Technology Lab. (NETL), Pittsburgh, PA, and Morgantown, WV (United States). In-house Research

Sponsoring Org.:

USDOE Office of Fossil Energy (FE)

OSTI Identifier:

1406264

Alternate Identifier(s):

OSTI ID: 1398160

Report Number(s):

NETL-PUB-21077
Journal ID: ISSN 2331-7019; PRAHB2

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review Applied

Additional Journal Information:

Journal Volume: 8; Journal Issue: 4; Journal ID: ISSN 2331-7019

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

03 NATURAL GAS; 20 FOSSIL-FUELED POWER PLANTS; 32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; 25 ENERGY STORAGE; 30 DIRECT ENERGY CONVERSION; 36 MATERIALS SCIENCE; 54 ENVIRONMENTAL SCIENCES; 60 APPLIED LIFE SCIENCES; Solid Oxide Fuel Cell, Cation Diffusion, La(1-x)Sr(x)MnO3 (x=0, 0.25), Density functional Theory