Stable high conductivity ceria/bismuth oxide bilayered electrolytes

• Published in: Journal of the Electrochemical Society Vol. 144; no. 1; pp. 233 - 236
• Main Authors: WACHSMAN, E. D, JAYAWEERA, P, JIANG, N, LOWE, D. M, POUND, B. G
• Format: Journal Article
• Language: English
• Published: Pennington, NJ Electrochemical Society 1997
• Subjects: Applied sciences; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cells; Cerium Oxides; Bismuth Oxides; Stability; Electronic conductivity; Electrolyte; Performance; Solid oxide fuel cell
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/1.1837390

A high conductivity bilayered ceria/bismuth oxide anolyte/electrolyte was developed that uses the pO2 gradient to obtain stability at the anolyte-electrolyte interface and reduced electronic conduction due to the electrolyte region. Results in terms of SOFC performance and stability are presented. These results include a 90 to 160 mV increase in open-circuit potential, depending on temperature, with the bilayered structure as compared to SOFCs fabricated from a single ceria layer. An open-circuit potential of greater than 1.0 V was obtained at 500 C with the bilayered structure. This increase in open-circuit potential is obtained without any measurable increase in cell resistance and is stable for over 1400 h of testing, under both open-circuit and maximum power conditions. Moreover, SOFCs fabricated from the bilayered structure result in a 33% greater power density compared to cells with a single ceria electrolyte layer. 10 refs.