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In this work, the effects of different sintering inhibitors added to La 0.8 Sr 0.2 MnO 3-∂ (LSM) were studied to obtain an optimum cathode material for cathode-supported type of Solid oxide fuel cell (SOFC) in terms of phase stability, mechanical strength, electric conductivity and porosity. Four different sintering inhibitors of Al₂O₃, CeO₂, NiO and gadolinium doped ceria (GDC) were mixed with LSM powder, sintered at 1300℃ and then they were evaluated. The phase stability, sintering behavior, electrical conductivity, mechanical strength and microstructure were evaluated in order to assess the performance of the mixture powder as cathode support material. It has been found that the addition of Al₂O₃ undesirably decreased the electrical conductivity of LSM; other sintering inhibitors, however, showed sufficient levels of electrical conductivity. GDC and NiO addition showed a promising increase in mechanical strength of the LSM material, which is one of the basic requirements in cathode-supported designs of fuel cells. However, NiO showed a high reactivity with LSM during high temperature (1300℃) sintering. So, this study concluded that GDC is a potential candidate for use as a sintering inhibitor for high temperature sintering of cathode materials.

An interconnect is the key component of solid oxide fuel cells that electrically connects unit cells and separates fuel from oxidant in the adjoining cells. To improve their surface stability in high-temperature oxidizing environments, metallic interconnects are usually coated with conductive oxides. In this study, lanthanum nickelates (LaNiO₃) with a perovskite structure are synthesized and applied as protective coatings on a metallic interconnect (Crofer 22 APU). The partial substitution of Co, Cu, and Fe for Ni improves electrical conductivity as well as thermal expansion match with the Crofer interconnect. The protective perovskite layers are fabricated on the interconnects by a slurry coating process combined with optimized heat-treatment. The perovskite-coated interconnects show area-specific resistances as low as 16.5 - 37.5 m Ω·㎠ at 800℃.

An interconnect in solid oxide fuel cells (SOFCs) electrically connects unit cells and separates fuel from oxidant in the adjoining cells. The interconnects can be divided broadly into two categories – ceramic and metallic interconnects. A thin and gastight ceramic layer is deposited onto a porous support, and metallic interconnects are coated with conductive ceramics to improve their surface stability. This paper provides a short review on ceramic materials for SOFC interconnects. After a brief discussion of the key requirements for interconnects, the article describes basic aspects of chromites and titanates with a perovskite structure for ceramic interconnects, followed by the introduction of dual-layer interconnects. Then, the paper presents protective coatings based on spinelor perovskite-type oxides on metallic interconnects, which are capable of mitigating oxide scale growth and inhibiting Cr evaporation.