Energy Conversion & StorageSolid oxide fuel cells (SOFCs) are devices that convert chemical energy to electrical energy directly through electrochemical oxidation of a wide variety of fuels with high efficiency and low emissions. Recently, significant efforts have focused on lowering the operating temperature to enhance long-term stability and reduce the manufacturing costs. The success relies on the development of highly active cathode materials for intermediate temperature applications because the cathode polarization is a limiting factor to cell performance at low temperatures.
Recently, layered perovskite oxides have been focus on one of the candidate materials for intermediate-temperature SOFCs, owing totheir substantially high electrical conductivities, rapid oxygen exchange, and fast oxygen diffusion characteristics. In this dissertation, the alternative cathode materials with adequate electrochemical activity and comparable TEC would be designed, which is the main issues to development of the intermediate temperature SOFCs. In this dissertation, some cathodic concept for improved performance would be suggested as following,
(1) Investigate the composite cathodes composed of NdBa0.5Sr0.5Co2O5+d and Ce0.9Gd0.1O1.95 (GDC) for optimized ratio between two materials to superior electrochemical properties under operating condition & The possible reaction zones for oxygen reduction reaction(ORR) on composite cathode
(2) Study the effect of Mn substitution for Co site on electrochemical properties of the NdBa0.5Sr0.5Co2-xMnxO5+d with reasonable TEC comparable with electrolyte materials.ope
