Influence of sintering temperature on the polarization resistance of La0.6Sr0.4Co0.2Fe0.8O3-δ - SDC carbonate composite cathode

Abstract

The effects of sintering temperature of an LSCF-samarium-doped ceria carbonate (SDCC) cathode composite film on its polarization resistance (Rp) were evaluated in this study. An LSCF-SDCC composite cathode was prepared for cathode film development by electrophoretic deposition (EPD). The LSCF-SDCC composite cathode was prepared at 50:50 weight percentage ratio. An EPD suspension which is based on an organic aqueous solution was used, and a mixture of ethanol and deionized water was used as medium with poly diallyl dimethyl ammonium chloride (PDADMAC) as a dispersing agent. SDCC substrate was used, and EPD was performed on both sides. A symmetrical cell with cathode composite LSCF-SDCC films on both sides of the substrate was subjected to sintering at five different temperatures (from 550°C to 750°C). A symmetrical cell was painted using silver paste before undergoing electrochemical performance test (air condition), in which the impedance, Z data, was measured. The effects of sintering temperature change on element content and film porosity were first investigated by energy-dispersive X-ray spectroscopy, field emission scanning electron microscopy, and J-image analysis. Ceramic-based cathode LSCF-SDCC that was sintered at 600°C exhibited the lowest Rp at a value of 0.68 Ω when operated at 650°C. This study proved that EPD has potential in developing IT-LT solid oxide fuel cell cathode components with high electrochemical performance in terms of Rp values.