INVESTIGADORES
MOGNI Liliana Veronica
congresos y reuniones científicas
Título:
The Soft Chemical Route Improving IT-SOFC Cathode Performance: The Lanthanum Barium Cobaltite Case.
Autor/es:
D. GARCES; L. MOGNI
Lugar:
San Francisco
Reunión:
Congreso; 224th ECS meeting; 2013
Institución organizadora:
Electrochemical Society
Resumen:
In this work we studied the oxygen
reduction mechanism in three cathodes: cubic La0.5Ba0.5CoO3-δ
obtained by Solid State Reaction (SSR) in air at 1100 ºC; a phase with cationic
order, laminar structure and tetragonal symmetry, LaBaCo2O6-δ,
was obtained by SSR under inert gas at 1150 ºC. An intermediate compound with
the same nominal composition was obtained at lower temperature by a soft
chemical route involving a sol-gel process. Despite that the crystal structures
of the oxides obtained by SSR are different, their microstructures are similar
but quite different to that obtained by the soft chemical route. The area
specific resistance (ASR) as a function of pO2 was studied at 700 °C
by Electrochemical Impedance Spectroscopy (EIS). We found that both, crystal
structure and microstructure affect strongly the ASR. Whereas cubic perovskite
showed lower ASR than tetragonal, the ASR of the oxide obtained by the chemical
route decreased almost one order of magnitude at higher pO2, respect
to that obtained by conventional SSR.