고체 산화물 연료전지 연결재용 YCC 페롭스카이트에 대한 철, 코발트, 니켈의 첨가 효과

Abstract

Y0.75Ca0.25Cr1-xMxO3-δ (M=Fe, Co, and Ni & x=0-0.2) perovskites oxides were synthesized by glycine nitrate process (GNP) method for use as interconnect materials in monolithic structure of flat tube solid oxide fuel cells, in which the interconnect should withstand both oxygen and hydrogen environment. Analyzed were their structural and physicochemical properties such as phase structure, sintering behavior, relative density, electrical conductivities in both oxidation and reduction environments, morphology and thermal expansion. XRD analyses confirm well-crystallized perovskite oxides. Data of relative density and HR-SEM data show that, upon sintering at 1400℃ for 10 h, Y0.75Ca0.25CrO3-δ (YCC) and Y0.75Ca0.25Cr1-xFexO3-δ (x=0-0.2) (YCCF) cannot sintered in air, distinct from, Y0.75Ca0.25Cr1-xCoxO3-δ (x=0-0.2) (YCCC), Y0.75Ca0.25Cr1-xNixO3-δ (x=0-0.2) (YCCN). In air environment, YCCN has good electrical conductivity in both air and H2 condition, but YCCC has poor electrical conductivity in H2 condition. YCCN10 shows remarkable electrical conductivities of 9.85 S/cm at 900℃ in air, and 1.15 S/cm at 900℃ in H2 atmosphere, and a very suitable thermal expansion coefficient value of 10.26㎛/mㆍ℃ (YSZ : 10.3㎛/mㆍ℃). These investigations have indicated that YCCN10 is a promising interconnect material for use in monolithic SOFC.