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

Patent metadata

Field	Value
Publication number	US-2020002168-A1
Application number	US-201816484945-A
Country	US
Kind code	A1
Filing date	Sep 28, 2018
Priority date	Sep 29, 2017
Publication date	Jan 2, 2020
Grant date	—

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

1 . A chalcogen-containing compound represented by the following Chemical Formula 1:
M y V 1-y Sn x Sb 2 Te x+3   [Chemical Formula 1]
wherein, in the above Chemical Formula 1, V is vacancy, M is at least one alkali metal, x≥6, and 0<y≤0.4.

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 is a vacant site excluding sites filled with Sn, Sb, and Te in the face-centered cubic lattice structure, and the M is filled in a part of the V.

5 . The chalcogen-containing compound of claim 3 , wherein
the Te is filled in an anion site of the face-centered cubic lattice structure, the Sn and Sb are filled in a cationic site of the face-centered cubic lattice structure, the V is a vacant site of the remaining cationic sites excluding the sites filled with Sn and Sb, and the M is filled in a part of the V.

6 . 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).

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

8 . 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 .

9 . 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.

10 . The method for preparing the chalcogen-containing compound of claim 9 , wherein the melting is carried out at a temperature of 700 to 900° C.

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

12 . The method for preparing the chalcogen-containing compound of claim 9 , 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.

13 . The method for preparing the chalcogen-containing compound of claim 9 , wherein the sintering is carried out by a spark plasma sintering method.

14 . The method for preparing the chalcogen-containing compound of claim 9 , wherein the sintering is carried out at a temperature of 550 to 640° C. under a pressure of 10 to 100 MPa.

15 . 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

• C30B25/02 Primary

  Epitaxial-layer growth · CPC title

• C04B2235/6567

  Treatment time · CPC title

• C04B35/62665

  Flame, plasma or melting treatment · CPC title

• C04B2235/661

  Multi-step sintering · CPC title

• C04B2235/40

  Metallic constituents or additives not added as binding phase · CPC title