Investigation of Mixed Conducting Cathode for Metal-Supported SOFC

Metal-supported solid oxide fuel cell (SOFC) is a promising concept in solving serious problems associated with current SOFC design. Metal-supported SOFC have many advantages as compared to current SOFC such as easy sealing, mechanical durability and cost reduction. However, they have also disadvantages such as diffusion of metallic components between metal-substrate and anode, corrosion of metal at high temperatures. Due to the cell fabrication and oxidation of metal substrate, unsintered cathode with high electrochemical activity at operating temperature is essential in order to obtain the better performance in the metal-supported SOFC. For this purpose, mixed conducting cathode materials for metal-supported SOFC were investigated by using SEM, XRD, EIS and particle size distribution (PSD) measurement. From the results of half cell test using 8YSZ electrolyte and SEM images, it was observed that (Ba,Sr)(Co,Fe)O_3-δ electrode showed the better electrochemical performance and sinterability at 1073 K than other conventional cathode material. It was also concluded from the long-term test that the buffer layer between electrolyte and cathode is necessary in order to eliminate the chemical reaction between the 8YSZ electrolyte and the cathode.