Microwave synthesis and excellent thermoelectric performances of Yb-filled CoSb3 skutterudites

摘要

The nearly single-phase Yb-filled and Te-doped YbxCo4Sb11.5Te0.5 are prepared by microwave, and the skut-terudites are further densification by spark plasma sintering. The experimental results show that Yb filling and Te doping further improve the electrical properties and confine the mean free path of phonons, resulting in a sig-nificant reduction the lattice thermal conductivity. And the maximum power factor of Yb0.2Co4Sb11.5Te0.5 is 4364.45 mu Wm- 1K-2 at 675 K. Analysis believes that the resonance scattering root from Yb filling and the defect scattering and stress field fluctuation introduced by Te doping can effectively limit the thermal transport per-formance. In 300-775 K, the total thermal conductivity of Yb0.2Co4Sb11.5Te0.5 is 2.68-3.74 Wm-1 K -1, and the maximum ZT is 1.25 at 775 K, revealing Yb filling and Te doping improve the electrical properties and reduce the thermal conductivity of by limiting the mean free path of phonons.

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