Behavior of oxygen concentration cells using BiCuVOx oxide-ion conductor

The mixed oxide, Bi2Cu0.1V0.9O5.35 often abbreviated as BiCuVOx, is known as an oxide-ionic conductor. The applicability of this oxide to a potentiometric oxygen sensor was investigated. Oxygen concentration cells were fabricated by using a disk of this oxide to test the EMF response to changes in oxygen concentration between 10% and 100% at various temperatures between 300 and 700 °C. As a result, the performances of the cells were found to depend very much on the kinds of electrode materials. When attached with Pt electrodes, the cell produced the EMF response fairly good only at 600 °C and above, whereas the oxide-ion transport number was close to unity even at 500 °C as evaluated from the Faraday efficiency of oxygen pumping current. The use of a perovskite-type oxide (La0.6Sr0.4Co0.8Fe0.2O3) instead of Pt was found to enable the cell to work at 400 °C and above. Especially excellent performances were observed when the oxide was mixed with BiCuVOx powder prior to being applied on the BiCuVOx disk as the electrodes.