Formation of p-type filled skutterudite by ball-milling and thermo-mechanical processing

Patent metadata

Field	Value
Publication number	US-9972760-B2
Application number	US-201414309567-A
Country	US
Kind code	B2
Filing date	Jun 19, 2014
Priority date	Jun 19, 2013
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

A method of manufacturing a thermoelectric material comprising: ball-milling a compound comprising a plurality of components, the first component M comprising at least one of a rare earth metal, an actinide, an alkaline-earth metal, and an alkali metal, the second component T comprising a metal of subgroup VIII, and the third component X comprises a pnictogen atom. The compound may be ball-milled for up to 5 hours, and then thermo-mechanically processed by, for example, hot pressing the compound for less than two hours. Subsequent to the thermo-mechanical processing, the compound comprises a single filled skutterudite phase with a dimensionless figure of merit (ZT) above 1.0 and the compound has a composition following a formula of MT 4 X 12 .

First claim

What is claimed is:

1. A method of manufacturing a thermoelectric material comprising:
thermo-mechanically processing a ball-milled compound, wherein, the compound, subsequent to the thermo-mechanical processing comprises:
a dimensionless figure of merit (ZT) above 1.0 at above about 700K,
a power factor above 20 μWK −2 cm −1 above about 400K,
a Seebeck coefficient above 120 μVK −1 above about 400K, and
a composition having the formula of MT 4 X 12 , wherein M comprises neodymium (Nd) and cerium (Ce).

2. The method of claim 1 , further comprising thermo-mechanically processing the compound for less than two hours.

3. The method of claim 1 , wherein the compound is in an as-cast state prior to ball-milling.

4. The method of claim 1 , wherein M further comprises at least one of a rare earth metal, an actinide, an alkaline-earth metal, and an alkali metal.

5. The method of claim 1 , wherein T comprises at least one metal of subgroup VIII.

6. The method of claim 1 , wherein X comprises at least one pnictogen.

7. The method of claim 1 , further comprising ball-milling the compound prior to the thermos-mechanical processing from about one hour to about five hours.

8. The method of claim 7 , further comprising hot-pressing the compound at a temperature from about 600° C. to about 700° C.

9. The method of claim 1 , further comprising thermo-mechanically processing the compound using hot-pressing.

10. The method of claim 1 , wherein the composition comprises Ce x Nd x Fe 3.5 Co 0.5 Sb 12 .

11. The method of claim 10 , wherein x is 0.45.

12. A method of manufacturing a thermoelectric material comprising:
thermo-mechanically processing a ball-milled compound for less than two hours, wherein the compound is formed by vacuum-melting according to a formula of MT 4 X 12 and comprises an average grain size from about 200 nm to about 500 nm,
wherein, M comprises neodymium (Nd),
wherein, subsequent to the thermo-mechanical processing, the thermoelectric material comprises:
a power factor above 20 μWK −2 cm −1 above about 400K,
a Seebeck coefficient above 120 μVK −1 above about 400K, and

a dimensionless figure of merit (ZT) above 1.0 at above about 700K.

13. The method of claim 12 , wherein M further comprises at least one of a rare earth metal, an actinide, an alkaline-earth metal, and an alkali metal.

14. The method of claim 12 , wherein T comprises a metal of subgroup VIII.

15. The method of claim 12 , wherein X comprises a pnictogen atom.

16. The method of claim 12 , further comprising thermo-mechanically processing the compound from about 600° C. to about 700° C.

17. The method of claim 12 , wherein the compound, subsequent to ball-milling, comprises a plurality of particles with an average diameter less than about 1 μm.

18. The method of claim 12 , wherein the compound is in an as-cast state prior to ball-milling.

Assignees

• Univ Houston System
• Massachusetts Inst Technology

Inventors

• Jie Qing
• Ren Zhifeng
• Chen Gang

Classifications

• B22F2301/00

  Metallic composition of the powder or its coating · CPC title

• B22F3/14

  simultaneously · CPC title

• C22C12/00 Primary

  Alloys based on antimony or bismuth · CPC title

• H01L35/20

  Electricity · mapped topic

• H01L35/34

  Electricity · mapped topic