Investigation of aliovalent transition metal doped La0.7Ca0.3Cr0.8X0.2O3−δ (X=Ti, Mn, Fe, Co, and Ni) as electrode materials for symmetric solid oxide fuel cells

The crystal phase, chemical stability, thermal expansion behavior, oxygen non-stoichiometry, electrical conductivity, and electro-catalytic activity of La0.7Ca0.3Cr0.8X0.2O3−δ (X=Ti, Mn, Fe, Co, and Ni) electrode materials have been investigated. All the compositions are chemically stable with a single-phase perovskite structure in both reducing and oxidizing atmospheres at high temperature. The linear thermal expansion coefficients of La0.7Ca0.3Cr0.8X0.2O3−δ are approximately 10×10−6 K−1. The total electrical conductivity of La0.7Ca0.3Cr0.8X0.2O3−δ increases in the order of X=Ti