An acidity-regulated double perovskite cathode for efficient and durable power generation of intermediate-temperature solid oxide fuel cells

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2024-07, Vol.12 (3), p.19392-1942
• Main Authors: Xu, Aoqin, Huan, Daoming, Dai, Pengqi, Zhang, Lu, Xia, Changrong
• Format: Article
• Language: English
• Subjects: Acidity; Cathodes; Cathodic polarization; Chemical reduction; Electrochemical analysis; Electrochemistry; Electrode polarization; Electrons; Fuel cells; Fuel technology; Operating temperature; Oxygen reduction reactions; Perovskites; Polarization; Solid oxide fuel cells; Stability tests; Temperature
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d4ta02853h

As solid oxide fuel cells (SOFCs) move towards commercial viability, it is imperative to reduce operating temperatures to intermediate ranges (500-700 °C). Nonetheless, the sluggish kinetics of the oxygen reduction reaction on the cathode remain a significant challenge, dominating the polarization resistance of the full cell as temperature decreases. This study proposes a highly active and durable cathode candidate for intermediate-temperature SOFCs through altering the acidity of double perovskite oxides. Herein, we present a novel A-site Eu-doped double perovskite oxide, EuBa 0.5 Sr 0.5 Co 2− x Fe x O 5+ δ (EBSCF x , x = 0.5, 1.0, and 1.5), demonstrating high efficiency and stability suitable for SOFC deployment. Notably, EBSCF1.0 exhibits remarkable stability and outstanding oxygen reduction reaction activity, boasting a very low interfacial polarization resistance of 0.097 Ω cm 2 at 650 °C in dry air. Utilizing this cathode, our button cell achieves exceptional electrochemical performance, yielding a peak power density of 1.50 W cm −2 at 650 °C accompanied by a 100 h stability test. This work reports a double perovskite oxide EuBa 0.5 Sr 0.5 Co 2− x Fe x O 5+δ (EBSCF x , x = 0.5, 1, and 1.5) as cathode for IT-SOFC. Specifically, the cell using EBSCF1.0 cathode delivers excellent performance with a PPD of 1.50 W cm −2 at 650 °C.