High thermoelectric energy conversion efficiency of a unicouple of n-type Mg3Bi2 and p-type Bi2Te3. (July 2021)

• Record Type: Journal Article
• Authors: Liang, Z.; Xu, C.; Shang, H.; Zhu, Q.; Ding, F.; Mao, J.; Ren, Z.
• Is Part Of: Materials today physics. Volume 19(2021)
• Publication Date: 2021-07
• Subjects: Mg3Bi2-based materials -- Energy conversion efficiency -- Low-grade heat recovery -- Contact resistance; Materials science -- Periodicals; Physics -- Periodicals; Electronic journals; 530.41
• DOI: 10.1016/j.mtphys.2021.100413
• Languages: English
• ISSNs: 2542-5293

Abstract

Abstract: Low-grade heat harvesting by thermoelectric technology can contribute to efficient energy utilization. However, the large-scale application of thermoelectric devices is partially hindered by their unsatisfactory performance and relatively high cost. Here we prepared a cost-effective n-type Mg3 Bi2 -based compound with a peak zT of 1.24 at 573 K. A unicouple comprised of n-type Mg3.2 Bi1.29 Sb0.7 Te0.01 and p-type Bi0.2 Sb1.8 Te3 was constructed and its energy conversion efficiency was evaluated. The unicouple exhibited a record-high efficiency of (9.0 ± 0.5)% or (8.3 ± 0.4)% [considering the radiation heat loss] under a temperature difference of 265 K at the hot-side temperature of 573 K. Our results demonstrate the great potential of Mg3 Bi2 -based materials for low-grade heat recovery. Graphical abstract: Image 1 Highlights: The n-type Mg3.2 Bi1.29 Sb0.7 Te0.01 compound exhibited a peak zT of 1.24 at 573 K. A unicouple comprised of n-type Mg3.2 Bi1.29 Sb0.7 Te0.01 and p-type Bi0.2 Sb1.8 Te3 was constructed and evaluated. A record-high efficiency of ∼9.0% could be achieved in the unicouple under a temperature difference of 265 K.