Enhancing ORR Catalytic Activity and Electrochemical Investigation of La1−2xBaxBixFeO3 Cathode for Low-Temperature Solid Oxide Fuel Cell

Abstract

Perovskite cathodes have emerged as a promising alternative to traditional cathode materials in low-temperature solid oxide fuel cells (LT-SOFCs) due to their exceptional catalytic properties and high oxygen reduction reaction (ORR) activity. Their fast catalytic activity and chemical stability have drawn significant attention to lowering the operating temperature of SOFCs. In this study, Ba2+ and Bi3+ are doped into LaFeO3. The aim is to investigate the catalytic activity and electrochemical performance of LT-SOFCs. The presented cathode material is characterized in terms of phase structure, surface morphology, and interface studies before being applied as a cathode in SOFCs to measure electrochemical performance. The XPS study revealed that La1−2xBaxBixFeO3 (x = 0.1) exhibits enriched surface oxygen vacancies compared to La1−2xBaxBixFeO3 (x = 0.2). La1−2xBaxBixFeO3 with (x = 0.1 and 0.2) delivers a peak power density of 665 and 545 mW cm−2 at 550 °C, respectively. Moreover, impedance spectra confirmed that La1−2xBaxBixFeO3 with x = 0.1 exhibits lower electrode polarization resistance (0.33 Ω cm2) compared to La1−2xBaxBixFeO3 with x = 0.2 (0.57 Ω cm2) at 550 °C. Our findings thus confirm that LBBF cathode-based SOFCs can be considered a potential cathode to operate fuel cells at low temperatures, and it will open up another horizon in the subject of research.