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

Patent metadata

Field	Value
Publication number	US-11024438-B2
Application number	US-201816462179-A
Country	US
Kind code	B2
Filing date	Jun 5, 2018
Priority date	Jun 7, 2017
Publication date	Jun 1, 2021
Grant date	Jun 1, 2021

Abstract

A chalcogen-containing compound of the following Chemical Formula 1 which exhibits excellent phase stability even at a low temperature, particularly at a temperature corresponding to an operating temperature of a thermoelectric element, and also exhibits a significantly superior power factor and thermoelectric performance index due to its excellent electrical conductivity and low thermal conductivity caused by its unique crystal lattice structure, a method for preparing the same, and a thermoelectric element including the same. [Chemical Formula 1]—V1-2xSn4Bi2-xAg3xSe7, wherein V is vacancy and 0<x<0.5.

First claim

The invention claimed is:

1. A chalcogen-containing compound represented by the following Chemical Formula 1:
V 1-2x Sn 4 Bi 2-x Ag 3x Se 7   [Chemical Formula 1]

wherein, in the above Chemical Formula 1, V is a vacancy and wherein x is 0.05≤x≤0.4.

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

3. The chalcogen-containing compound of claim 2 , wherein the vacancy is a vacant site excluding sites filled with Se, Sn, Bi, and Ag in the face-centered cubic crystal lattice structure, and the Ag is substituted by replacing a part of the Bi.

4. The chalcogen-containing compound of claim 2 , wherein the Se is filled in an anion site of the face-centered cubic crystal lattice structure, the Sn and Bi are filled in a cationic site of the face-centered cubic lattice structure, the vacancy is a vacant site of the remaining sites excluding the sites filled with Se, Sn, and Bi, and the Ag is substituted by replacing a part of the Bi.

5. A thermoelectric conversion material comprising the chalcogen-containing compound according to claim 1 .

6. A thermoelectric element comprising the chalcogen-containing compound according to claim 1 .

7. A method for preparing the chalcogen-containing compound according to claim 1 , comprising the steps of:
mixing raw materials of Sn, Bi, Ag, and Se and then melting the raw materials to prepare a melt;
heat-treating the melt;
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 raw materials of Sn, Bi, Ag, and Se are mixed at a molar ratio of Sn:Bi:Ag:Se corresponding to 4:2−x:3x:7, and the x is 0.05≤x≤0.4.

9. The method for preparing the chalcogen-containing compound of claim 7 , wherein the melting is carried out at a temperature of 750 to 1000° C.

10. The method for preparing the chalcogen-containing compound of claim 7 , wherein the heat treatment is carried out at a temperature of 500 to 700° C.

11. 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.

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

13. The method for preparing the chalcogen-containing compound of claim 7 , wherein the sintering step is carried out at a temperature of 550 to 700° C. under a pressure of 10 to 130 MPa.

Assignees

• Lg Chemical Ltd

Inventors

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

Classifications

• C01G29/006

  Compounds containing bismuth, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• C01G19/006

  Compounds containing tin, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• C01P2002/77

  by unit-cell parameters, atom positions or structure diagrams · CPC title

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title

• H01B1/06 Primary

  mainly consisting of other non-metallic substances · CPC title