| About this Abstract |
| Meeting |
MS&T21: Materials Science & Technology
|
| Symposium
|
Energy Materials for Sustainable Development
|
| Presentation Title |
The Electrical Conductivity and Defect Chemistry of Co, Sc-doped BaZrO<sub>3</sub> |
| Author(s) |
Hiroki Uehara, Akihiro Ishii, Itaru Oikawa, Hitoshi Takamura |
| On-Site Speaker (Planned) |
Hiroki Uehara |
| Abstract Scope |
The electrical conductivity of a mixed proton-hole conductor, Co, Sc-doped BaZrO<sub>3</sub> as a cathode material for proton- conducting SOFC was analyzed assuming bond percolation, and its defect chemistry was revealed. The total conductivity was measured in a wet oxidizing atmosphere. As the cobalt concentration increased, the total conductivity abruptly increased while its activation energy decreased. This result can be explained by percolation theory. The percolation threshold of conductivity for Co, Sc-doped BaZrO<sub>3</sub> was smaller than that in Fe-doped BaZrO<sub>3</sub> reported by D. Kim. This implies that electronic hole can widely distributes in Co, Sc-doped BaZrO<sub>3</sub>. The transport number of proton was 0.05 for the sample with [Co] = 0.04. The major defect is hole under high <i>P</i><sub>O<sub>2</sub></sub> region, while oxide-ion conduction is also suggested judging form a slope of less than 1/4 for the <i>P</i><sub>O<sub>2</sub></sub> dependence of conductivity. |