Synthesis of N-type thermoelectric materials, including Mg—Sn—Ge materials, and methods for fabrication thereof

Patent metadata

Field	Value
Publication number	US-10930834-B2
Application number	US-201515547374-A
Country	US
Kind code	B2
Filing date	Dec 10, 2015
Priority date	Feb 9, 2015
Publication date	Feb 23, 2021
Grant date	Feb 23, 2021

Abstract

Discussed herein are systems and methods for fabrication of MgSnGe-based thermoelectric materials for applications from room temperature and near room temperature to high temperature applications. The TE materials may be fabricated by hand or ball milling a powder to a predetermined particle size and hot-pressing the milled powder to form a thermoelectric component with desired properties including a figure of merit (ZT) over a temperature range. The TE materials fabricated may be disposed in thermoelectric devices for varying applications.

First claim

What is claimed is:

1. A method of manufacturing an n-type thermoelectric material comprising:
hot-pressing a powder comprising:
a first component consisting of magnesium (Mg);
a second component consisting of tin (Sn); and
a third component consisting of germanium (Ge); according to the formula Mg 2 Sn 0.75 Ge 0.25 into a pressed component, wherein the pressed component comprises a ZT value of at least 1.0 at about 450° C.

2. The method of claim 1 , wherein, prior to hot-pressing, the powder is formed using ball-milling.

3. The method of claim 2 , wherein the powder is ball-milled for up to 20 hours.

4. The method of claim 2 , wherein the powder is hot-pressed between about 600° C. and about 800° C. from about 1 second to about 30 minutes.

5. The method of claim 1 , wherein the ZT value is about 1.4 at about 450° C.

6. The method of claim 1 , wherein a power factor of the pressed component is from about 45 μW cm −1 K −2 to about 55 μW cm −1 K −2 from about 350° C. to about 450° C.

7. The method of claim 1 , wherein hot-pressing the powder comprises holding the powder at a temperature from about 500° C. to about 800° C. for a period of about 1 second to about 30 minutes.

8. The method of claim 1 , wherein the powder is a pure phase powder.

9. The method of claim 1 , further comprising annealing the pressed component from about 300° C. to about 500° C. from about 0.3 h to about 5 h.

10. A thermoelectric device comprising:
an n-type thermoelectric material comprising:
a first component consisting of magnesium (Mg);
a second component consisting of tin (Sn); and
a third component consisting of germanium (Ge); according to the formula Mg 2 Sn 0.75 Ge 0.25 into a pressed component, wherein the pressed component comprises a ZT value of at least 1.0 at about 450° C. and a power factor of about 52 μW cm −1 K −2 at about 25° C. to 450° C.

Assignees

• Univ Houston System

Inventors

• Ren Zhifeng
• Liu Weishu

Classifications

• H10N10/01 Primary

  Manufacture or treatment · CPC title

• H10N10/8556

  comprising compounds containing germanium or silicon · CPC title

• C22C23/00

  Alloys based on magnesium · CPC title

• B22F2998/10

  Processes characterised by the sequence of their steps · CPC title

• B22F3/14

  simultaneously · CPC title