Grain boundary complexions stabilize Mg3Sb2-based thermoelectric devices with superior performance

Joule, vol. 10, pp. 102443

Abstract

The practical application of Mg 3 Sb 2 -based thermoelectrics has been largely retarded by their poor thermal stability, mainly due to the rapid loss of Mg at elevated temperatures. Here, we prove that grain boundaries are fast diffusion channels for Mg, and we block these channels by forming Ga-rich grain boundary complexions. This design suppresses the formation of Mg vacancies at grain boundaries and inhibits the outward diffusion of Mg and the inward growth of MgO-related phases. Consequently, the thermal stability of Mg 3 Sb 2 -based materials is significantly improved at a high temperature of 718 K for at least 80 h. The corresponding single-leg Mg 3 Sb 2 -based device can maintain a conversion efficiency of 12.5% ± 0.6% for 7 days at a temperature difference of 423 K during the cycle test. Our findings provide an atomic-scale grain boundary engineering approach to enhance the thermal stability of thermoelectric devices and other functional materials operating at elevated temperatures.

Authors 12

1. Yang Geng

   Shenzhen University · Nanjing University of Science and Technology · Guangdong Research Center for Interfacial Engineering of Functional Materials

   Affiliation as printed

   College of Materials Science and Engineering, Guangdong Provincial Key Laboratory of New Energy Materials Service Safety, Guangdong Research Center for Interfacial Engineering of Functional Materials, Institute of Deep Underground Sciences and Green Energy, Shenzhen University, Shenzhen 518060, China

   School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, China

2. Zhenyu Wang

   Max-Planck-Institut für Nachhaltige Materialien

   Affiliation as printed

   Max Planck Institute for Sustainable Materials, 40237 Düsseldorf, Germany

3. Yali Liu

   Shenzhen University · Guangdong Research Center for Interfacial Engineering of Functional Materials

   Affiliation as printed

   College of Materials Science and Engineering, Guangdong Provincial Key Laboratory of New Energy Materials Service Safety, Guangdong Research Center for Interfacial Engineering of Functional Materials, Institute of Deep Underground Sciences and Green Energy, Shenzhen University, Shenzhen 518060, China

4. Dominique Alexander Mattlat

   Max-Planck-Institut für Nachhaltige Materialien

   Affiliation as printed

   Max Planck Institute for Sustainable Materials, 40237 Düsseldorf, Germany

5. Lipeng Hu

   Shenzhen University · Guangdong Research Center for Interfacial Engineering of Functional Materials

   Affiliation as printed

   College of Materials Science and Engineering, Guangdong Provincial Key Laboratory of New Energy Materials Service Safety, Guangdong Research Center for Interfacial Engineering of Functional Materials, Institute of Deep Underground Sciences and Green Energy, Shenzhen University, Shenzhen 518060, China

6. Fusheng Liu

   Shenzhen University · Guangdong Research Center for Interfacial Engineering of Functional Materials

   Affiliation as printed

   College of Materials Science and Engineering, Guangdong Provincial Key Laboratory of New Energy Materials Service Safety, Guangdong Research Center for Interfacial Engineering of Functional Materials, Institute of Deep Underground Sciences and Green Energy, Shenzhen University, Shenzhen 518060, China

7. Christina Scheu

   Max-Planck-Institut für Nachhaltige Materialien

   Affiliation as printed

   Max Planck Institute for Sustainable Materials, 40237 Düsseldorf, Germany

8. Gerald Jeffrey Snyder

   Northwestern University

   Affiliation as printed

   Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA

9. Matthias Wuttig Aachen Institute of Physics (IA)

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   Institute of Physics (IA), RWTH Aachen University, 52074 Aachen, Germany

   Peter Grünberg Institute (PGI 10), Forschungszentrum Jülich, 52428 Jülich, Germany

10. Yuan Yu corresponding Aachen Institute of Physics (IA)

    RWTH Aachen University

    Affiliation as printed

    Institute of Physics (IA), RWTH Aachen University, 52074 Aachen, Germany

11. Siyuan Zhang corresponding

    Max-Planck-Institut für Nachhaltige Materialien

    Affiliation as printed

    Max Planck Institute for Sustainable Materials, 40237 Düsseldorf, Germany

12. Chaohua Zhang corresponding

    Shenzhen University · Guangdong Research Center for Interfacial Engineering of Functional Materials

    Affiliation as printed

    College of Materials Science and Engineering, Guangdong Provincial Key Laboratory of New Energy Materials Service Safety, Guangdong Research Center for Interfacial Engineering of Functional Materials, Institute of Deep Underground Sciences and Green Energy, Shenzhen University, Shenzhen 518060, China