Chalcogen-containing compound, its preparation method and thermoelectric element comprising the same

Patent metadata

Field	Value
Publication number	US-11097947-B2
Application number	US-201816484945-A
Country	US
Kind code	B2
Filing date	Sep 28, 2018
Priority date	Sep 29, 2017
Publication date	Aug 24, 2021
Grant date	Aug 24, 2021

Abstract

A chalcogen-containing compound of the following chemical formula which exhibits an excellent thermoelectric performance index (ZT) through an increase in power factor and a decrease in thermal conductivity, a method for preparing the same, and a thermoelectric element including the same: M y V 1-y Sn x Sb 2 Te x+3 , wherein V is vacancy, M is at least one alkali metal, x≥6, and 0<y≤0.4.

First claim

The invention claimed is:

1. A chalcogen-containing compound represented by the following Chemical Formula 1:
[Chemical Formula 1]
M y V 1-Y Sn x Sb 2 Te x+3

wherein, in the above Chemical Formula 1, V is vacancy, M is at least one alkali metal, x≥6, and 0<y≤0.4; and
wherein the alkali metal (M) is filled in a part of the vacancy (V).

2. The chalcogen-containing compound of claim 1 , wherein the M is at least one alkali metal selected from the group consisting of Na and K.

3. The chalcogen-containing compound of claim 1 , wherein the chalcogen-containing compound has a face-centered cubic crystal lattice structure.

4. The chalcogen-containing compound of claim 3 , wherein the V, Sn, Sb, and M are randomly distributed at a site of (x, y, z) =(0, 0, 0), and Te is distributed at a site of (x, y, z) =(0.5, 0.5, 0.5).

5. The chalcogen-containing compound of claim 1 , wherein 6≤x≤12 and 0.01≤y≤0.4.

6. The chalcogen-containing compound of claim 1 , which is selected from the group consisting of Na 0.2 V 0.8 Sn 6 Sb 2 Te 9 , Na 0.2 V 0.8 Sn 8 Sb 2 Te 11 , Na 0.2 V 0.8 Sn 10 Sb 2 Te 13 , Na 0.2 V 0.8 Sn 12 Sb 2 Te 15 , Na 0.1 V 0.9 Sn 8 Sb 2 Te 11 , and Na 0.4 V 0.6 Sn 8 Sb 2 Te 11 .

7. A method for preparing the chalcogen-containing compound of claim 1 comprising:
mixing raw materials of Sn, Sb, Te, and M so that a molar ratio of Sn:Sb:Te:M is x:2:(x+3):y and then subjecting the mixture to a melting reaction wherein x≥6 and 0≤y≤0.4, and M is at least one alkali metal;
heat-treating the resultant product obtained through the melting reaction;
pulverizing the resultant product obtained through the heat treatment; and
sintering the pulverized product.

8. The method for preparing the chalcogen-containing compound of claim 7 , wherein the melting is carried out at a temperature of 700 to 900° C.

9. The method for preparing the chalcogen-containing compound of claim 7 , wherein the heat treatment is carried out at a temperature of 550 to 640° C.

10. The method for preparing the chalcogen-containing compound of claim 7 , further comprising a step of cooling the resultant of the heat treatment step to form an ingot between the heat treatment step and the pulverization step.

11. The method for preparing the chalcogen-containing compound of claim 7 , wherein the sintering is carried out by a spark plasma sintering method.

12. The method for preparing the chalcogen-containing compound of claim 7 , wherein the sintering is carried out at a temperature of 550 to 640° C. under a pressure of 10 to 100 MPa.

13. A thermoelectric element comprising the chalcogen-containing compound of claim 1 .

Assignees

• Lg Chemical Ltd

Inventors

• Kim Min Kyoung
• Min Yu Ho
• Park Cheol Hee
• Ko Kyung Moon
• Park Chee Sung
• Jung Myung Jin

Classifications

• C01P2002/30

  Three-dimensional structures · CPC title

• C30B29/46 Primary

  Sulfur-, selenium- or tellurium-containing compounds · CPC title

• C04B2235/666

  Applying a current during sintering, e.g. plasma sintering [SPS], electrical resistance heating or pulse electric current sintering [PECS] · CPC title

• C04B2235/5436

  micrometer sized, i.e. from 1 to 100 micron · CPC title

• C04B2235/762

  Cubic symmetry, e.g. beta-SiC · CPC title