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

Patent metadata

Field	Value
Publication number	US-11309476-B2
Application number	US-201816310554-A
Country	US
Kind code	B2
Filing date	Mar 19, 2018
Priority date	May 15, 2017
Publication date	Apr 19, 2022
Grant date	Apr 19, 2022

Abstract

The present invention relates to a novel chalcogen-containing compound that exhibits excellent phase stability even at a temperature corresponding to the driving temperature of a thermoelectric element, and has a high output factor and thermoelectric figure of merit, a method for preparing the same, and a thermoelectric element including the same.

First claim

The invention claimed is:

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

wherein, in Chemical Formula 1, V is a vacancy, M is an alkali metal,
x, y, z, and 4−z are mole ratios of V, M, Pb, and, Sn, respectively, x is greater than 0 and less than 1, y is greater than 0 and less than 1, x+y is greater than 0 and equal to or less than 1, z is greater than 0 and equal to or less than 4, and x+y+z is greater than 0 and equal to or less than 5.

2. The chalcogen-containing compound according to claim 1 , wherein M is one or more alkali metals selected from the group consisting of Li, Na, and K.

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

4. The chalcogen-containing compound according to claim 3 , wherein the vacancy (V) is a vacant site excluding the sites filled with Se, Sn, Pb and Bi in the face-centered cubic lattice structure, and M is filled in a part of the vacancy (V).

5. The chalcogen-containing compound according to claim 3 , wherein
the Se fills anion sites of the face-centered cubic lattice structure,
the Sn, the Pb and the Bi fill cation sites of the face-centered cubic lattice structure,
the vacancy (V) is a vacant site of remaining cation sites, excluding the sites filled with Sn, Pb, and Bi, and
the M is filled in a part of the vacancy (V).

6. The chalcogen-containing compound according to claim 3 , wherein the Pb is substituted at the Sn site, in the face-centered cubic lattice structure.

7. The chalcogen-containing compound according to claim 1 , wherein the compound is used as thermoelectric conversion material.

8. A method for preparing the chalcogen-containing compound of claim comprising the steps of:
melting a mixture comprising raw materials of Sn, Pb, Bi, Se, and an alkali metal (M);
heat treating the molten mixture;
grinding the heat treated product; and
sintering the ground product.

9. The method for preparing a chalcogen-containing compound according to claim 8 , wherein the melting is performed at a temperature of 750 to 900° C.

10. The method for preparing a chalcogen-containing compound according to claim 8 , wherein the heat treatment is performed at a temperature of 500 to 650° C.

11. The method for preparing a chalcogen-containing compound according to claim 8 , further comprising a step of cooling the product of the heat treatment step to form an ingot, between the heat treatment step and the grinding step.

12. The method for preparing a chalcogen-containing compound according to claim 8 , wherein the sintering step is performed by a spark plasma sintering method.

13. The method for preparing a chalcogen-containing compound according to claim 8 , wherein the sintering step is performed at a temperature of 550 to 700° C. and a pressure of 10 to 130 MPa.

14. A thermoelectric element comprising the chalcogen-containing compound according to claim 1 , as a thermoelectric conversion material.

Assignees

• Lg Chemical Ltd

Inventors

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

Classifications

• C01B19/002 Primary

  Compounds containing, besides selenium or tellurium, more than one other element, with -O- and -OH not being considered as anions · CPC title

• C01P2006/32

  Thermal properties · CPC title

• C01P2006/40

  Electric properties · CPC title

• H01L35/16 Primary

  Electricity · mapped topic

• H01L35/34

  Electricity · mapped topic