About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
Energy Materials for Sustainable Development
|
| Presentation Title |
Pushing the Boundaries in Thermoelectrics: Intergranular Engineering at Atomic and Nano Scales to Achieve the Oxide Ceramics with ZT>1 |
| Author(s) |
Xueyan Song, Cesar-Octavio Romo-De-La-Cruz, Yun Chen |
| On-Site Speaker (Planned) |
Xueyan Song |
| Abstract Scope |
The carrier mobility and electrical conductivity of ceramics are usually significantly reduced by the presence of grain boundaries. To improve the thermoelectric performance of polycrystalline oxide, including p-type Ca3Co4O9+δ and n-type oxide CaMnO3, we have developed a unique approach to design the chemistry of polycrystalline oxide ceramics with specific dopants and further drive individual dopants, to either discretely segregate at the grain boundaries or form percolating secondary phase segregation along the grain boundaries to simultaneously increase the Seebeck coefficient, electrical conductivity, and thermoelectric figure of merit up to ZT> 1. Our work presents a feasible and valuable practical approach for treating the grain boundaries in ceramics as a two-dimensional intergranular secondary phase complexion with a Seebeck coefficient magnitude higher than that of the intragrain and independently tunable to decouple the strongly correlated physical parameters and simultaneously enhance the Seebeck coefficient, electrical power factor, and ZT over a broad temperature range. |