Terbium and Tungsten Co-doped Bismuth Oxide Electrolytes for Low Temperature Solid Oxide Fuel Cells |
Doh Won Jung, Kang Taek Lee1, Eric D. Wachsman2 |
Samsung Advanced Institute of Technology 1Department of Energy Systems Engineering, DGIST (DaeguGyeongbuk Institute Science and Technology) 2University of Maryland Energy Research Center, University of Maryland |
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ABSTRACT |
We developed a novel double dopant bismuth oxide system with Tb and W. When Tb was doped as a single dopant, a Tb dopant concentration more than 20 mol% was required to stabilize bismuth oxides with a high conductivity cubic structure. High temperature XRD analysis of 25 mol% Tb-doped bismuth oxide (25TSB) confirmed that the cubic structure of 25TSB was retained from room temperature to $700^{circ}C$ with increase in the lattice parameter. On the other hand, we achieved the stabilization of high temperature cubic phase with a total dopant concentration as low as ~12 mol% with 8 mol% Tb and 4 mol% W double dopants (8T4WSB). Moreover, the measured ionic conductivity of 10T5WSB was much higher than 25TSB, thus demonstrating the feasibility of the double dopant strategy to develop stabilized bismuth oxide systems with higher oxygen ion conductivity for the application of SOFC electrolytes at reduced temperature. In addition, we investigated the long-term stability of TSB and TWSB electrolytes. |
Key words:
Solid oxide fuel cells, Electrolytes, Bismuth oxides, Double dopants |
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