A-site deficient semiconductor electrolyte Sr1−xCoxFeO3−δ for low-temperature (450–550 °C) solid oxide fuel cells. Issue 38 (30th August 2022)

• Record Type: Journal Article
• Authors: Lu, Yuzheng; Yousaf Shah, M. A. K.; Mushtaq, Naveed; Yousaf, Muhammad; Lund, Peter D.; Zhu, Bin; Asghar, Muhammad Imran
• Is Part Of: RSC advances. Volume 12:Issue 38(2022)
• Page Start: 24480
• Page End: 24490
• Publication Date: 2022-08-30
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d2ra03823d
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Fast ionic conduction at low operating temperatures is a key factor for the high electrochemical performance of solid oxide fuel cells (SOFCs). Abstract : Fast ionic conduction at low operating temperatures is a key factor for the high electrochemical performance of solid oxide fuel cells (SOFCs). Here an A-site deficient semiconductor electrolyte Sr1− x Co x FeO3− δ is proposed for low-temperature solid oxide fuel cells (LT-SOFCs). A fuel cell with a structure of Ni/NCAL-Sr0.7 Co0.3 FeO3− δ –NCAL/Ni reached a promising performance of 771 mW cm −2 at 550 °C. Moreover, appropriate doping of cobalt at the A-site resulted in enhanced charge carrier transportation yielding an ionic conductivity of >0.1 S cm −1 at 550 °C. A high OCV of 1.05 V confirmed that neither short-circuiting nor power loss occurred during the operation of the prepared SOFC device. A modified composition of Sr0.5 Co0.5 FeO3− δ and Sr0.3 Co0.7 FeO3− δ also reached good fuel cell performance of 542 and 345 mW cm −2, respectively. The energy bandgap analysis confirmed optimal cobalt doping into the A-site of the prepared perovskite structure improved the charge transportation effect. Moreover, XPS spectra showed how the Co-doping into the A-site enhanced O-vacancies, which improve the transport of oxide ions. The present work shows that Sr0.7 Co0.3 FeO3− δ is a promising electrolyte for LT-SOFCs. Its performance can be boosted with Co-doping to tune the energy band structure.