Title: Engineering the Thermoelectric Transport in Half-Heusler Materials through a Bottom-Up Nanostructure Synthesis

Abstract

Half-Heusler (HH) alloys are among the best promising thermoelectric (TE) materials applicable for the middle-to-high temperature power generation. Despite of the large thermoelectric power factor and decent figure-of-merit ZT (≈1), their broad applications and enhancement on TE performance are limited by the high intrinsic lattice thermal conductivity (κ_L) due to insufficiencies of phonon scattering mechanisms, and the fewer powerful strategies associated with the microstructural engineering for HH materials. This study reports a bottom-up nanostructure synthesis approach for these HH materials based on the displacement reaction between metal chlorides/bromides and magnesium (or lithium), followed by vacuum-assisted spark plasma sintering process. The samples are featured with dense dislocation arrays at the grain boundaries, leading to a minimum κ_L of ≈1 W m^-1 K^-1 at 900 K and one of the highest ZT (≈1) and predicted η (≈11%) for n-type Hf_0.25Zr_0.75NiSn_0.97Sb_0.03. Further manipulation on the dislocation defects at the grain boundaries of p-type Nb_0.8Ti_0.2FeSb leads to enhanced maximum power factor of 47 × 10^-4 W m^-1 K^-2 and the predicted η of ≈7.5%. Moreover, vanadium substitution in FeNb_0.56V_0.24Ti_0.2Sb significantly promotes the η to ≈11%. This strategy can be extended to a broad range of advanced alloys and compounds for improved properties.

Authors:

Zhao, Huaizhou ^[1]; Cao, Binglei ^[2]; Li, Shanming ^[1]; Liu, Ning ^[1]; Shen, Jiawen ^[3]; Li, Shan ^[1]; Jian, Jikang ^[4]; Gu, Lin ^[1]; Pei, Yanzhong ^[3]; Snyder, Gerald Jeffrey ^[5]; Ren, Zhifeng ^[6]; Chen, Xiaolong ^[1]

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+ Show Author Affiliations

1. Chinese Academy of Sciences (CAS), Beijing (China). Beijing National Lab. for Condensed Matter Physics, Inst. of Physics
2. Chinese Academy of Sciences (CAS), Beijing (China). Beijing National Lab. for Condensed Matter Physics, Inst. of Physics; Guangdong Univ. of Technology Guangzhou (China). Physics and Optoelectronic Engineering College
3. Tongji Univ., Shanghai (China). School of Materials Science and Engineering
4. Guangdong Univ. of Technology Guangzhou (China). Physics and Optoelectronic Engineering College
5. Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering
6. Univ. of Houston, TX (United States). Dept. of Physics and TcSUH

Publication Date:

Tue May 16 00:00:00 EDT 2017

Research Org.:

Energy Frontier Research Centers (EFRC) (United States). Solid-State Solar-Thermal Energy Conversion Center (S3TEC)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1470530

Alternate Identifier(s):

OSTI ID: 1393299

Grant/Contract Number:  

SC0001299; FG02-09ER46577

Resource Type:

Accepted Manuscript

Journal Name:

Advanced Energy Materials

Additional Journal Information:

Journal Volume: 7; Journal Issue: 18; Related Information: S3TEC partners with Massachusetts Institute of Technology (lead); Boston College; Oak Ridge National Laboratory; Rensselaer Polytechnic Institute; Journal ID: ISSN 1614-6832

Publisher:

Wiley

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; dislocation synthesis; enhanced TE performance; half‐Heusler thermoelectrics; lattice thermal conductivity; transport properties manipulation; solar (photovoltaic); solar (thermal); solid state lighting; phonons; thermal conductivity; thermoelectric; defects; mechanical behavior; charge transport; spin dynamics; materials and chemistry by design; optics; synthesis (novel materials); synthesis (self-assembly); synthesis (scalable processing)