Enhanced Thermoelectric Performance by Strong Phonon Scattering at the Heterogeneous Interfaces of the Mg2Sn/Mg3Sb2 High-Content Nanocomposite

• Published in: ACS applied materials & interfaces Vol. 13; no. 47; pp. 56164 - 56170
• Main Authors: Zhu, Yongbin, Han, Zhijia, Han, Bing, Jiang, Feng, Wu, Xinzhi, Han, Cheng-Gong, Deng, Yonghong, Liu, Weishu
• Format: Journal Article
• Language: English
• Published: American Chemical Society 01.12.2021
• Subjects: Energy, Environmental, and Catalysis Applications; microstructure; nanocomposites; thermal conductivity; lattice thermal conductivity; high-content nanocomposites; effective medium theory; high Kapitza resistance; heterogeneous interfaces; Mg2Sn/Mg3Sb2
• ISSN: 1944-8244; 1944-8252; 1944-8252
• DOI: 10.1021/acsami.1c16299

Nano approaches are practical strategies to boost the thermoelectric figure of merit due to the strong phonon scattering from the grain boundaries and nanoinclusions. Here, we have reported a strong phonon scattering at the heterogeneous interfaces of Mg2Sn/Mg3Sb2 high-content nanocomposites (HCnCs). As a result, a significantly reduced lattice thermal conductivity of 1.09 W m–1 K–1 was observed in the equimolar Mg2Sn/Mg3Sb2 HCnC, 80% lower than pure Mg2Sn and 25% lower than pure Mg3Sb2. As a result, a high ZT ∼ 1.13 at 773 K was achieved in the Mg2Sn/Mg3Sb2 HCnC. Furthermore, various defects, including solid solutions, nanoinclusions, and misfit dislocations, were observed in both the Mg3Sb2 phase and the Mg2Sn phase through the microstructure characterization.