Highly stabilized and efficient thermoelectric copper selenide

Haihua Hu; Yiwei Ju; Jincheng Yu; Zechao Wang; Jun Pei; Hao-Cheng Thong; Jing-Wei Li; Bowen Cai; Fengming Liu; Zhanran Han; Bin Su; Hua-Lu Zhuang; Yilin Jiang; Hezhang Li; Qian Li; Huijuan Zhao; Bo-Ping Zhang; Jing Zhu; Jing-Feng Li

doi:10.1038/s41563-024-01815-1

Highly stabilized and efficient thermoelectric copper selenide

Nat Mater. 2024 Apr;23(4):527-534. doi: 10.1038/s41563-024-01815-1. Epub 2024 Mar 7.

Authors

Haihua Hu^#¹, Yiwei Ju^#^{1

2

3}, Jincheng Yu⁴, Zechao Wang^{1

2

3}, Jun Pei^{1

5}, Hao-Cheng Thong¹, Jing-Wei Li¹, Bowen Cai⁶, Fengming Liu⁶, Zhanran Han¹, Bin Su¹, Hua-Lu Zhuang¹, Yilin Jiang¹, Hezhang Li⁷, Qian Li¹, Huijuan Zhao^{1

2

3}, Bo-Ping Zhang⁵, Jing Zhu^{8

9

10}, Jing-Feng Li¹¹

Affiliations

¹ State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China.
² National Center of Electron Microscopy in Beijing, School of Materials Science and Engineering, Tsinghua University, Beijing, China.
³ Ji Hua Laboratory, Foshan, China.
⁴ State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China. jinchengyu@tsinghua.edu.cn.
⁵ The Beijing Municipal Key Laboratory of New Energy Materials and Technologies, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, China.
⁶ Guangxi Pilot Free Trade Zone Jianju Technology Co., Ltd, Qinzhou, China.
⁷ Department of Precision Instrument, Tsinghua University, Beijing, China.
⁸ State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China. jzhu@mail.tsinghua.edu.cn.
⁹ National Center of Electron Microscopy in Beijing, School of Materials Science and Engineering, Tsinghua University, Beijing, China. jzhu@mail.tsinghua.edu.cn.
¹⁰ Ji Hua Laboratory, Foshan, China. jzhu@mail.tsinghua.edu.cn.
¹¹ State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China. jingfeng@mail.tsinghua.edu.cn.

^# Contributed equally.

PMID: 38454027
DOI: 10.1038/s41563-024-01815-1

Abstract

The liquid-like feature of thermoelectric superionic conductors is a double-edged sword: the long-range migration of ions hinders the phonon transport, but their directional segregation greatly impairs the service stability. We report the synergetic enhancement in figure of merit (ZT) and stability in Cu_1.99Se-based superionic conductors enabled by ion confinement effects. Guided by density functional theory and nudged elastic band simulations, we elevated the activation energy to restrict ion migrations through a cation-anion co-doping strategy. We reduced the carrier concentration without sacrificing the low thermal conductivity, obtaining a ZT of ∼3.0 at 1,050 K. Notably, the fabricated device module maintained a high conversion efficiency of up to ∼13.4% for a temperature difference of 518 K without obvious degradation after 120 cycles. Our work could be generalized to develop electrically and thermally robust functional materials with ionic migration characteristics.