Multiple-Filled Skutterudites: High Thermoelectric Figure of Merit through Separately Optimizing Electrical and Thermal Transports
Top Cited Papers
- 27 April 2011
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 133 (20), 7837-7846
- https://doi.org/10.1021/ja111199y
Abstract
Skutterudites CoSb3 with multiple cofillers Ba, La, and Yb were synthesized and very high thermoelectric figure of merit ZT = 1.7 at 850 K was realized. X-ray diffraction of the densified multiple-filled bulk samples reveals all samples are phase pure. High-resolution scanning transmission electron microscopy (STEM) and energy dispersive X-ray spectroscopy (EDS) analysis confirm that multiple guest fillers occupy the nanoscale-cages in the skutterudites. The fillers are further shown to be uniformly distributed and the Co−Sb skutterudite framework is virtually unperturbed from atomic scale to a few micrometers. Our results firmly show that high power factors can be realized by adjusting the total filling fraction of fillers with different charge states to reach the optimum carrier density, at the same time, lattice thermal conductivity can also be significantly reduced, to values near the glass limit of these materials, through combining filler species of different rattling frequencies to achieve broad-frequency phonon scattering. Therefore, partially filled skutterudites with multiple fillers of different chemical nature render unique structural characteristics for optimizing electrical and thermal transports in a relatively independent way, leading to continually enhanced ZT values from single- to double-, and finally to multiple-filled skutterudites. The idea of combining multiple fillers with different charge states and rattling frequencies for performance optimization is also expected to be valid for other caged TE compounds.Keywords
This publication has 51 references indexed in Scilit:
- High-Pressure Synthesis, Structure, and Electrical Property of Iodine-Filled Skutterudite I0.9Rh4Sb12—First Anion-Filled SkutteruditeChemistry of Materials, 2009
- High thermoelectric performance of triple-filledn-type skutterudites (Sr,Ba,Yb)yCo4Sb12Journal of Physics D: Applied Physics, 2009
- Enhanced thermoelectric performance of dual-element-filled skutterudites BaxCeyCo4Sb12Acta Materialia, 2009
- Transport and mechanical properties of Yb-filled skutteruditesPhilosophical Magazine, 2009
- Evaluation of Half‐Heusler Compounds as Thermoelectric Materials Based on the Calculated Electrical Transport PropertiesAdvanced Functional Materials, 2008
- Thermodynamic analysis of the filling fraction limits for impurities in CoSb3 based on ab initio calculationsActa Materialia, 2008
- Low thermal conductivity and high thermoelectric figure of merit in n-type BaxYbyCo4Sb12 double-filled skutteruditesApplied Physics Letters, 2008
- BoltzTraP. A code for calculating band-structure dependent quantitiesComputer Physics Communications, 2006
- Thermoelectric Materials for Space and Automotive Power GenerationMRS Bulletin, 2006
- Filling Fraction Limit for Intrinsic Voids in Crystals: Doping in SkutteruditesPhysical Review Letters, 2005