Study of LnBaCo2O6−ä (Ln = Pr, Nd, Sm and Gd) doubled perovskites as new cathode material for IT-SOFC

E. CHAVEZ; M. MUELLER; L. MOGNI; A. CANEIRO

Iguazu

Simposio; SLAFES XIX; 2008

Oxides with double perovskites structures of general composition LnBaCo2O6−LnBaCo2O6− (Ln = Pr, Nd, Sm and Gd) were synthesized by solid state reaction with the purpose to evaluate new materials to be used as cathodes in intermediate temperature solid oxide fuel cell (ITSOFC). A preliminary study about electrochemical properties was performed by impedance spectroscopy between 500 and 800 C under atmosphere of pure O2. Symmetrical cells were obtained by spray deposition of LnBaCo2O6− (Ln = Pr, Nd, Sm and Gd) at both sides of a dense ceramic electrolyte. The impedance spectroscopy measurements as a function of temperatures show a hysteresis loop which could be associated to a tetragonal/orthorhombic phase transition. The existence of this transition was corroborated by high temperature X-Ray diffraction and Differential Scanning Calorimetry measurements.C under atmosphere of pure O2. Symmetrical cells were obtained by spray deposition of LnBaCo2O6− (Ln = Pr, Nd, Sm and Gd) at both sides of a dense ceramic electrolyte. The impedance spectroscopy measurements as a function of temperatures show a hysteresis loop which could be associated to a tetragonal/orthorhombic phase transition. The existence of this transition was corroborated by high temperature X-Ray diffraction and Differential Scanning Calorimetry measurements.LnBaCo2O6− (Ln = Pr, Nd, Sm and Gd) at both sides of a dense ceramic electrolyte. The impedance spectroscopy measurements as a function of temperatures show a hysteresis loop which could be associated to a tetragonal/orthorhombic phase transition. The existence of this transition was corroborated by high temperature X-Ray diffraction and Differential Scanning Calorimetry measurements.