Electrical and microstructural characterization of two-step sintered ceria-based electrolytes

• Published in: Journal of power sources Vol. 187; no. 1; pp. 204 - 208
• Main Authors: Lapa, C.M., Souza, D.P. Ferreira de, Figueiredo, F.M.L., Marques, F.M.B.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.02.2009; Elsevier
• Subjects: Applied sciences; Ceria; Disks; Dwell; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Firing; Fuel cells; Gallium; Grain boundaries; Grain size; Microstructure; Sintering; Sintering (powder metallurgy); Solid electrolytes; Solid oxide fuel cells; Solid oxide fuel cells; Solid electrolytes; Microstructure; Sintering; Ceria; Grain size; Scanning electron microscopy; Densification; Doping; Solid electrolyte; Cerium oxide; Solid oxide fuel cell; Grain boundary; Characterization; Gadolinium oxides; Porosity; X ray diffractometry; Electrochemical impedance spectroscopy
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2008.10.071

Gadolinium-doped ceria-based materials with and without Ga-additions were prepared following several firing schedules including one peak sintering temperature (up to 1300 °C) with or without subsequent dwell at lower temperature (at 1150 °C). Sintered disks with submicrometric grain size and densifications in the order of 92% or higher, were obtained in this manner, with the final result depending slightly on the sintering profile and presence of Ga as dopant. All materials were characterized by scanning electron microscopy, X-ray diffraction and impedance spectroscopy in air, in the temperature range 200–800 °C. The grain boundary arcs were found slightly dependent on grain size and porosity but significantly on Ga-doping, due to the likely presence of large concentrations of Ga along the grain boundary region.