YBaCo2O5+δ as a new cathode material for zirconia-based solid oxide fuel cells

Phase equilibria, crystal structure and oxygen content of intermediate phases in the Y–Ba–Co–O system

“…The relative thermal expansion (ΔL/L o ) of the YBaCo 2 O 5 þ δ ceramic sample also increases practically linearly with increasing temperature in the temperature range of 298-1273 K. The average thermal expansion coefficient (TEC) of double perovskite in the measured temperature range is about 13.8 Â 10 −6 , K −1 , which is close to the value reported by Liu [3]. …”

“…The family of LnBaCo 2 O 5 þ δ so-called double perovskites, in particular with Ln ¼Y, was intensively studied during last decade since they exhibit a set of properties such as high values of mixed electronic-ionic conductivity and oxygen mobility [1,2] that allows considering them as the promising cathode materials for the SOFCs [3]. Another representative of the Y-Ba-Co-O system that attracts attention of many researchers is YBaCo 4 O 7 þ δ [4][5][6][7].…”

“…Another representative of the Y-Ba-Co-O system that attracts attention of many researchers is YBaCo 4 O 7 þ δ [4][5][6][7]. Although a number of papers were devoted to the structure and physicochemical properties of LnBaCo 2 O 5 þ δ and YBaCo 4 O 7 þ δ , including the crystal structure and oxygen content [1][2][3][4][5][6][7][8][9][10][11] the information about phase equilibria in the YBa-Co-O system is absent. The only data that can be found has concern the phase formation in the quasibinary Y-Co-O, Y-Ba-O and Ba-Co-O systems.…”

Study and optimization of the synthesis routine of the single phase YBaCo2O6-δ double perovskite

“…This pattern was refined as a mixture of two phases having 3×2×2 and 1×2×2 superstructures. The former has tetragonal structure (s. g. P4/mmm) with cell parameters a = b = 11.596(4) Å and c = 7.509(7) Å whereas the latter has orthorhombic structure (s. g. Pmma) with cell parameters a = 3.821(4) Å, b = 7.846(2) Å, c = 7.515(8) Å in full agreement with available structural data [5,7,12,26,27].…”

“…Complex oxide YBaCo 2 O 6-δ with double perovskite structure has been extensively investigated in recent years as a promising material for oxygen membranes [1,2] and solid oxide fuel cells (SOFCs) [3,6,7,9,12] due to high mixed ionic-electronic conductivity [12] and moderate thermal expansion comparable to that of the state-of-the art SOFC electrolytes [3]. However, YBaCo 2 O 6-δ is unstable in air at temperatures between 800 and 850 °C [13] and decomposes to mixture of the simple perovskites YCoO 3-δ and BaCoO 3-δ , which are more thermodynamically stable under these conditions.…”