Bonding State and Thermal Expansion Coefficient of Mn-Doped Ba<sub>0.5</sub>Sr<sub>0.5</sub>FeO<sub>3−δ</sub> Perovskite Oxides for IT-SOFCs

The oxygen vacancy formation behavior and electrochemical and thermal properties of Ba<sub>0.5</sub>Sr<sub>0.5</sub>Fe<sub>1−x</sub>Mn<sub>x</sub>O<sub>3−δ</sub> (BSFMnx, x = 0–0.15) cathode materials were investigated. For thermogravimetri...

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Main Authors: Taeheun Lim, Sung-sin Yun, Kanghee Jo, Heesoo Lee
Format: Article
Language:English
Published: MDPI AG 2023-12-01
Series:Nanomaterials
Subjects:
Online Access:https://www.mdpi.com/2079-4991/14/1/82
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author Taeheun Lim
Sung-sin Yun
Kanghee Jo
Heesoo Lee
author_facet Taeheun Lim
Sung-sin Yun
Kanghee Jo
Heesoo Lee
author_sort Taeheun Lim
collection DOAJ
description The oxygen vacancy formation behavior and electrochemical and thermal properties of Ba<sub>0.5</sub>Sr<sub>0.5</sub>Fe<sub>1−x</sub>Mn<sub>x</sub>O<sub>3−δ</sub> (BSFMnx, x = 0–0.15) cathode materials were investigated. For thermogravimetric analysis, the weight decreased from 1.98% (x = 0) to 1.81% (x = 0.15) in the 400–950 °C range, which was due to oxygen loss from the lattice. The average oxidation state of the B-site increased, the O<sub>ads</sub>/O<sub>lat</sub> ratio decreased, and the binding energy of the O<sub>lat</sub> peak increased with Mn doping. These results indicate that Mn doping increases the strength of the metal–oxygen bond and decreases the amount of oxygen vacancies in the lattice. The electrical conductivity of BSFMnx increased with the temperature due to the thermally activated small-polaron hopping mechanism showing a maximum value of 10.4 S cm<sup>−1</sup> (x = 0.15) at 450 °C. The area-specific resistance of BSFMn0.15 was 0.14 Ω cm<sup>2</sup> at 700 °C and the thermal expansion coefficient (TEC) gradually decreased to 12.7 × 10<sup>−6</sup> K<sup>−1</sup>, which is similar to that of Ce<sub>0.8</sub>Sm<sub>0.2</sub>O<sub>2</sub> (SDC) (12.2 × 10<sup>−6</sup> K<sup>−1</sup>). Mn doping increased the metal–oxygen bonding energy, which reduced the oxygen reduction reaction activity but improved the electrical conductivity and thermal stability with SDC.
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spelling doaj.art-5155f0436cc44b0e92d32a2a7041dcae2024-01-10T15:05:02ZengMDPI AGNanomaterials2079-49912023-12-011418210.3390/nano14010082Bonding State and Thermal Expansion Coefficient of Mn-Doped Ba<sub>0.5</sub>Sr<sub>0.5</sub>FeO<sub>3−δ</sub> Perovskite Oxides for IT-SOFCsTaeheun Lim0Sung-sin Yun1Kanghee Jo2Heesoo Lee3School of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of KoreaSchool of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of KoreaSchool of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of KoreaSchool of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of KoreaThe oxygen vacancy formation behavior and electrochemical and thermal properties of Ba<sub>0.5</sub>Sr<sub>0.5</sub>Fe<sub>1−x</sub>Mn<sub>x</sub>O<sub>3−δ</sub> (BSFMnx, x = 0–0.15) cathode materials were investigated. For thermogravimetric analysis, the weight decreased from 1.98% (x = 0) to 1.81% (x = 0.15) in the 400–950 °C range, which was due to oxygen loss from the lattice. The average oxidation state of the B-site increased, the O<sub>ads</sub>/O<sub>lat</sub> ratio decreased, and the binding energy of the O<sub>lat</sub> peak increased with Mn doping. These results indicate that Mn doping increases the strength of the metal–oxygen bond and decreases the amount of oxygen vacancies in the lattice. The electrical conductivity of BSFMnx increased with the temperature due to the thermally activated small-polaron hopping mechanism showing a maximum value of 10.4 S cm<sup>−1</sup> (x = 0.15) at 450 °C. The area-specific resistance of BSFMn0.15 was 0.14 Ω cm<sup>2</sup> at 700 °C and the thermal expansion coefficient (TEC) gradually decreased to 12.7 × 10<sup>−6</sup> K<sup>−1</sup>, which is similar to that of Ce<sub>0.8</sub>Sm<sub>0.2</sub>O<sub>2</sub> (SDC) (12.2 × 10<sup>−6</sup> K<sup>−1</sup>). Mn doping increased the metal–oxygen bonding energy, which reduced the oxygen reduction reaction activity but improved the electrical conductivity and thermal stability with SDC.https://www.mdpi.com/2079-4991/14/1/82cobalt-free cathodeoxygen vacancyoxygen reduction reactionarea-specific resistancethermal expansion coefficient
spellingShingle Taeheun Lim
Sung-sin Yun
Kanghee Jo
Heesoo Lee
Bonding State and Thermal Expansion Coefficient of Mn-Doped Ba<sub>0.5</sub>Sr<sub>0.5</sub>FeO<sub>3−δ</sub> Perovskite Oxides for IT-SOFCs
Nanomaterials
cobalt-free cathode
oxygen vacancy
oxygen reduction reaction
area-specific resistance
thermal expansion coefficient
title Bonding State and Thermal Expansion Coefficient of Mn-Doped Ba<sub>0.5</sub>Sr<sub>0.5</sub>FeO<sub>3−δ</sub> Perovskite Oxides for IT-SOFCs
title_full Bonding State and Thermal Expansion Coefficient of Mn-Doped Ba<sub>0.5</sub>Sr<sub>0.5</sub>FeO<sub>3−δ</sub> Perovskite Oxides for IT-SOFCs
title_fullStr Bonding State and Thermal Expansion Coefficient of Mn-Doped Ba<sub>0.5</sub>Sr<sub>0.5</sub>FeO<sub>3−δ</sub> Perovskite Oxides for IT-SOFCs
title_full_unstemmed Bonding State and Thermal Expansion Coefficient of Mn-Doped Ba<sub>0.5</sub>Sr<sub>0.5</sub>FeO<sub>3−δ</sub> Perovskite Oxides for IT-SOFCs
title_short Bonding State and Thermal Expansion Coefficient of Mn-Doped Ba<sub>0.5</sub>Sr<sub>0.5</sub>FeO<sub>3−δ</sub> Perovskite Oxides for IT-SOFCs
title_sort bonding state and thermal expansion coefficient of mn doped ba sub 0 5 sub sr sub 0 5 sub feo sub 3 δ sub perovskite oxides for it sofcs
topic cobalt-free cathode
oxygen vacancy
oxygen reduction reaction
area-specific resistance
thermal expansion coefficient
url https://www.mdpi.com/2079-4991/14/1/82
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AT sungsinyun bondingstateandthermalexpansioncoefficientofmndopedbasub05subsrsub05subfeosub3dsubperovskiteoxidesforitsofcs
AT kangheejo bondingstateandthermalexpansioncoefficientofmndopedbasub05subsrsub05subfeosub3dsubperovskiteoxidesforitsofcs
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