Electrochemical and material characteristics of Ba0.5Sr0.5Co0.8Fe0.2O3−δ-Sm0.2Ce0.8O1.9 carbonate perovskite cathode composite for low-temperature solid oxide fuel cell

• Published in: Ceramics International
• Main Author: Tan K.H.; Rahman H.A.; Azami M.S.; Yusop U.A.; Baharuddin N.A.; Ma'arof M.I.N.
• Format: Article
• Language: English
• Published: Elsevier Ltd 2022
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85136536064&doi=10.1016%2fj.ceramint.2022.07.325&partnerID=40&md5=002802fc108aa09d017cad9b7dec39cb

This paper presents the development of a new composite cathode Ba0.5Sr0.5Co0.8Fe0.2O3−δ-Sm0.2Ce0.8O1.9 carbonate (BSCF-SDCC). The BSCF-SDCC (50 wt% BDCF: 50 wt% SDCC) composite cathode was developed by low-speed ball milling in ethanol. The composite cathode is prepared in powder and pellet form, followed by calcination at 600 °C. The BSCF-SDCC composite cathode is examined by microstructural analysis, phase analysis, chemical bonding, thermal expansion coefficient (TEC), thermogravimetric analysis (TGA), and electrochemical impedance spectroscopy. X-ray diffraction proves the vigorous reaction between BSCF and SDCC powder after calcination. The carbonate bond in BSCF-SDCC was assessed by Fourier transform infrared spectroscopy (FTIR). TECs of the BSCF-SDCC cathode and SDCC matched each other. In TGA, BaCO3 weight gain is observed at 400 °C-650 °C for BSCF-SDCC powder without calcination. In general, BSCF-SDCC powder is not encouraged for calcination, but its pellet form is suitable. Electrochemical performance is tested from 400 °C to 600 °C. BSCF-SDCC after sintering achieves the lowest polarization resistance of 0.45 Ω, lowest area specific resistance of 0.29 Ωcm2, and highest conductivity of 149.0 Scm-1 at 600 °C. The conductivity is nearly 122% higher than BSCF, which only has a conductivity of 67 Scm-1. This is due to the existing carbonate layer which reduce the polarization loss and facilities the ions' conduction, thus electric conductivity is increased. The findings reveal a promising characteristic of the BSCF-SDCC composite for low-temperature solid oxide fuel cell cathode application. © 2022 Elsevier Ltd and Techna Group S.r.l.