Enhanced Thermoelectric Properties of Mg<sub>2</sub>Sn-Mg<sub>3</sub>Sb<sub>2</sub> Nanocomposites by Tailoring Matrix/Inclusion Interface toward Energy Harvesting Applications
Yongbin Zhu, Rui Shu, Feng Jiang, Anna Elsukova, Per O. Å. Persson, Per Eklund, Weishu Liu
Abstract
High Resolution Image Download MS PowerPoint Slide Nanocomposites have been long exploited for achieving balanced material properties. Here, we synthesized nominal (Mg 2 Sn 0.85 Sb 0.15 ) 1– x -(Mg 3 Sb 2 ) x ( x = 0–0.15) nanocomposites, achieving a significant reduction of the lattice thermal conductivity of Mg 2 Sn 0.85 Sb 0.15 from 2.03 Wm –1 K –1 to 1.38 Wm –1 K –1 due to phonon scattering by V Mg point defects, Mg 3 Sb 2 nanoparticles, and heterogeneous interfaces. Hence, a significantly enhanced thermoelectric figure of merit, ZT, is achieved. At 773 K, the sample of x = 0.075 reaches a ZT of 1.4, corresponding to a 14% enhancement compared to the Mg 2 Sn 0.85 Sb 0.15 ( x = 0) sample. The strategy of introducing heterogeneous structures has important implications for reducing thermal conductivity for other solid-solution thermoelectric systems.