Preparation and properties of (YCa)(TiMn)O3-δ ceramics interconnect of solid oxide fuel cells

Abstract

(YCa)(TiMn)O3-δ ceramics prepared using a reaction-sintering process were investigated. Without any calcination involved, the mixture of raw materials was pressed and sintered directly. Y2Ti2O7 instead of YTiO3 formed when a mixture of Y2O3 and TiO2 with Y/Ti ratio 1/1 were sintered in air. Y2Ti2O7, YTiO2.085 and some unknown phases were detected in Y0.6Ca0.4Ti0.6Mn0.4O3-δ. Monophasic Y0.6Ca0.4Ti0.4Mn0.6O3-δ ceramics were obtained after 1400-1500 °C sintering. Dense Y0.6Ca0.4Ti0.4Mn0.6O3-δ with a density 4.69 g/cm3 was observed after 1500 °C/4 h sintering. Log s for Y0.6Ca0.4Ti0.6Mn0.4O3-δ increased from -3.73 Scm-1 at 350 °C to -2.14 Scm-1 at 700 °C. Log s for Y0.6Ca0.4Ti0.4Mn0.6O3-δ increased from -2.1 Scm-1 at 350 °C to -1.36 Scm-1 at 700 °C. Increasing Mn content decreased activation energy Ea and increased electrical conductivity. Reaction-sintering process is proved to be a simple and effective method to obtain (YCa)(TiMn)O3-δ ceramics for interconnects in solid oxide fuel cells.