Fabrication of La0.6Sr0.4Co0.2Fe0.8O3-δ cathodes with enhanced specific surface area via powder flash-light irradiation for solid oxide fuel cells

Abstract

The size, crystallinity and morphology of powders are considerably influenced by the powder synthesis method and conditions. The solid-state synthesis method, commonly used for synthesizing ceramic powders, involves a prolonged high-temperature calcination process to develop crystallinity. However, this process can yield large particle sizes. In this study, we employed a novel powder calcination technique, i.e., powder flash-light irradiation (P-FLI), to develop the crystallinity of lanthanum strontium cobalt ferrite (LSCF) powder within seconds, thereby preventing powder agglomeration. The P-FLI-calcined LSCF powder exhibited a pure perovskite structure and a higher specific surface area than conventional thermally calcined LSCF powders. Additionally, we prepared pastes using the calcined powder for deposition as a cathode layer, and by applying film FLI (F-FLI), we suppressed the formation of SrZrO3 secondary phases at the YSZ/LSCF interface without introducing a buffer layer such as gadolinium-doped ceria. Therefore, the P-FLI/F-FLI LSCF cathode demonstrated excellent performance, i.e., a peak power density of 1.3 W/cm2 at 750 degrees C. The FLI system used for LSCF powder calcination and cathode sintering significantly reduced the fabrication time of solid-oxide fuel cells and prevented powder agglomeration and the formation of secondary phases at the interface. This method is promising for application in various fields, addressing issues related to powder agglomeration and the formation of secondary phases at the interface.

The size, crystallinity and morphology of powders are considerably influenced by the powder synthesis method and conditions. The solid-state synthesis method, commonly used for synthesizing ceramic powders, involves a prolonged high-temperature calcination process to develop crystallinity. However, this process can yield large particle sizes. In this study, we employed a novel powder calcination technique, i.e., powder flash-light irradiation (P-FLI), to develop the crystallinity of lanthanum strontium cobalt ferrite (LSCF) powder within seconds, thereby preventing powder agglomeration. The P-FLI-calcined LSCF powder exhibited a pure perovskite structure and a higher specific surface area than conventional thermally calcined LSCF powders. Additionally, we prepared pastes using the calcined powder for deposition as a cathode layer, and by applying film FLI (F-FLI), we suppressed the formation of SrZrO3 secondary phases at the YSZ/LSCF interface without introducing a buffer layer such as gadolinium-doped ceria. Therefore, the P-FLI/F-FLI LSCF cathode demonstrated excellent performance, i.e., a peak power density of 1.3 W/cm2 at 750 ◦C. The FLI system used for LSCF powder calcination and cathode sintering significantly reduced the fabrication time of solid-oxide fuel cells and prevented powder agglomeration and the formation of secondary phases at the interface. This method is promising for application in various fields, addressing issues related to powder agglomeration and the formation of secondary phases at the interface.