Sc and Ta-doped SrCoO3-δ perovskite as a high-performance cathode for solid oxide fuel cells

Xu, Xiaoyong and Zhao, Jie and Li, Mengran and Zhuang, Linzhou and Zhang, Jinxuan and Aruliah, Sathia and Liang, Fengli and Wang, Hao and Zhu, Zhonghua (2019) Sc and Ta-doped SrCoO3-δ perovskite as a high-performance cathode for solid oxide fuel cells. Composites Part B: Engineering, 178:107491. pp. 1-7. ISSN 1359-8368


Abstract

Sealing and stability is the challenge for solid oxide fuel cells (SOFCs) at high temperature. It is crucial to operate SOFCs at a low temperature to avoid these issues. Thus, it is necessary to improve the sluggish oxygen reduction reaction (ORR) activity of cathode. The SrCoO3-δ perovskite with a cubic phase is identified as a potential cathode material for SOFCs due to its high oxygen permeability and reasonable electrical conductivity. However, it readily decomposes into the orthorhombic structured brownmillerite Sr2Co2O5 or hexagonal Sr6Co5O15 during high-temperature sintering resulting in the loss of a significant amount of lattice oxygen. Herein, we partially replace Co with Sc and Ta at SrCoO3-δ to stabilize its cubic perovskite structure and restrain the lattice oxygen loss, thus improving the oxygen-ionic conductivity, and the structural and chemical stability. The synthesized SrSc0.175Ta0.025Co0.8O3-δ (SSTC) cathode achieves a remarkably high ORR performance and an area-specific resistance obtained in this study reaches as low as 0.233, 0.033, and 0.004 Ω cm2 at 500, 600, and 700 °C, respectively. The new Sc and Ta-doped SrCoO3-δ perovskite cathode even present a better ORR activity than the previously reported Sc and Nb-doped SrCoO3-δ cathode. The reason for the improved performance by Ta doping is possible that Ta–O bond is stronger than Nb–O bond and the electronegativity of Ta5+ is lower than that of Nb5+, resulting in a lower valence state of cobalt and a higher oxygen vacancies concentration.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials (1 Jan 2017 -)
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials (1 Jan 2017 -)
Date Deposited: 04 Mar 2022 03:36
Last Modified: 28 Mar 2022 03:20
Uncontrolled Keywords: Cathode material; Electrochemistry; Oxygen reduction reaction; Perovskite; Solid oxide fuel cell; SrCoO3-δ
Fields of Research (2008): 09 Engineering > 0912 Materials Engineering > 091205 Functional Materials
Fields of Research (2020): 40 ENGINEERING > 4016 Materials engineering > 401605 Functional materials
Socio-Economic Objectives (2008): E Expanding Knowledge > 97 Expanding Knowledge > 970109 Expanding Knowledge in Engineering
Socio-Economic Objectives (2020): 28 EXPANDING KNOWLEDGE > 2801 Expanding knowledge > 280110 Expanding knowledge in engineering
Identification Number or DOI: https://doi.org/10.1016/j.compositesb.2019.107491
URI: http://eprints.usq.edu.au/id/eprint/46442

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