Fabrication and characteristics of the cathode for metal-supported SOFC

초록

Lowering the operating temperature of solid oxide fuel cells allowed the use of metal components instead of ceramic interconnect. The requirement of robustness of the stack has prompted the exploration of alternative unit cell design. Recently, some research groups have been developing ferritic steel supported solid oxide fuel cells as alternative configurations. The porous metallic alloy provides the mechanical support for the electrolyte film, and serves as the electrical connection, while the electrochemical function is maintained by thin layer of anode adjacent to the solid electrolyte. Alloys such as ferritic steel have very high electronic conductivity, good corrosion r?istance, and thermal expansion coefficients that are well matched to yttria-stabilized zirconia. The deposition of thin-films structures on porous alloy support can be accomplished by co-firing the appropriate metal supported microstructure. It is necessary sinter such structures in a reducing environment. Therefore, many research groups have difficulty in finding out the appropriate preparation conditions of electrodes for metal-supported SOFC. Perovskite oxides were selected as candidates of the cathode materials in this study. In this work, we investigated the proper cathode material and processing suitable for firing in reducing atmospheres and low temperature bonding to the thin-film electrolyte. The effect of ceria as buffer layer on the cathode performances was investigated.