Pt–perovskite cermet cathode for reduced-temperature SOFCs

In order to develop a cathode for reduced-temperature solid oxide fuel cells, cermetting effect of LSCF with Pt was investigated. The effect of cermetting was observed. However, the obtained cathode activity was only an order of 0.5 S/cm2 at 973 K. The activation energy at low and high LSCF/Pt ratios was smaller than that at medium LSCF/Pt ratio region. The cathode interfacial conductivity, σE, of the very low Pt containing LSCF cermet cathode increased with increasing cathode thickness, whereas with high Pt content, σE showed optimum. These results suggested that Pt has both enhancing and obstructing functions. Based on SEM observation, the main reason of these complicated results was considered to be due to poor porosity and narrow surface area due to high electrode sintering temperature. Pt may enhance sintering of LSCF. So reduced-temperature cathode sintering should be investigated for LSCF/Pt cathode preparation.