Enhanced anti-chromium poisoning ability of high entropy La0.2Nd0.2Sm0.2Sr0.2Ba0.2Co0.2Fe0.8O3-δ cathodes for solid oxide fuel cells

• Published in: Journal of alloys and compounds Vol. 982; p. 173753
• Main Authors: Zheng, Tong, Li, Zhiyuan, Wang, Donggang, Pan, Zhaoxu, Sun, Haibin, Song, Tao, Zhao, Shikai
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30.04.2024
• Subjects: Cr poisoning; High-entropy oxides; Solid oxide fuel cells; Sr segregation; High-entropy oxides; Solid oxide fuel cells; Cr poisoning; Sr segregation
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2024.173753

The instability of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF6428) for Cr-containing atmospheres limits its utilization in the cathode of solid oxide fuel cells (SOFCs). High entropy La0.2Nd0.2Sm0.2Sr0.2Ba0.2Co0.2Fe0.8O3-δ (HE-LSCF) is presented as a potential Cr-resistant cathode in this paper. At a test temperature of 750 °C, the polarization resistance (Rp) of the cathode of HE-LSCF is 0.53 Ω cm2 after 40 h of Cr-treatment, which is comparable with the original value without Cr-treatment (0.50 Ω cm2 at 750 °C), and significantly lower than LSCF6428 cathodes with the same Cr-treatment condition (3.11 Ω cm2 at 750 °C), suggesting an excellent ability of anti-chromium poisoning. Raman and DFT simulation results verify that the high-entropy structure effectively suppresses the segregation of SrO and prevents Cr vapor from reacting with the segregated SrO to form SrCrO4 due to the higher segregation energy (1.38 eV) and lower desorption energy (−2.55 eV) of HE-LSCF. The anode-supported single cell of NiO-SDC/SDC/HE-LSCF shows a peak power density of 556 mW cm−2 at 700 °C with wet H2 (with ∼3 vol% H2O) fuels and ambient air oxidants, and maintains a stable cell performance after the Cr-treatment (537 mW cm−2). •A-site high-entropy LSCF cathode is fabricated a combustion method.•The cathode shows excellent ability of anti-chromium poisoning.•The mechanism of anti-chromium poisoning is verified by DFT simulation