High-Performance and Stable (Ag, Cd)-Containing ZnSb Thermoelectric Compounds

Sai Yang; Tingting Deng; Pengfei Qiu; Tong Xing; Jun Cheng; Zhicheng Jin; Peng Li; Xun Shi; Lidong Chen

doi:10.1021/acsami.2c03304

High-Performance and Stable (Ag, Cd)-Containing ZnSb Thermoelectric Compounds

ACS Appl Mater Interfaces. 2022 Jun 1. doi: 10.1021/acsami.2c03304. Online ahead of print.

Authors

Sai Yang^{1

2}, Tingting Deng³, Pengfei Qiu^{1

2}, Tong Xing¹, Jun Cheng^{1

2}, Zhicheng Jin^{1

2}, Peng Li^{1

2}, Xun Shi^{1

2}, Lidong Chen^{1

2}

Affiliations

¹ State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China.
² Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
³ School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China.

PMID: 35650510
DOI: 10.1021/acsami.2c03304

Abstract

Binary Zn-Sb-based compounds, ZnSb and Zn₄Sb₃, are promising thermoelectric (TE) materials because they are low-cost and earth-abundant. However, for a long time, their real applications have been limited by the low TE figure-of-merit (zT) of ZnSb and poor thermodynamic stability of Zn₄Sb₃. In this study, we successfully integrate both high zT and good stability in (Ag, Cd)-containing ZnSb compounds. Alloying Cd in ZnSb greatly suppresses the lattice thermal conductivity to a minimum value of 0.97 W K^-1 m^-1 at 300 K, while doping Ag significantly enhances the power factor to a peak value of 17.7 μW cm^-1 K^-2 at 500 K and reduces the bipolar thermal conductivity. As a result of the simultaneously optimized electrical and thermal transport, a peak zT of 1.2 is achieved for Zn_0.698Ag_0.002Cd_0.3Sb at 600 K, which is comparable with the best values reported for Zn₄Sb₃-based compounds. Moreover, a current stress test confirms that introducing Ag and Cd does not degrade the good stability of ZnSb under an electric field. The phase composition and thermoelectric performance of Zn_0.698Ag_0.002Cd_0.3Sb are not changed even under a high current density of 50 A cm^-2, showing much better stability than Zn₄Sb₃. This study would accelerate the real application of ZnSb-based compounds in the field of waste heat harvesting.

Keywords: Zn4Sb3; ZnSb; alloying; doping; stability; thermoelectric.