THERMOELECTRIC NANOCOMPOSITE AND PROCESS OF PRODUCING THE SAME

• US 20170110644A1
• Filed: 04/01/2016
• Published: 04/20/2017
• Est. Priority Date: 10/14/2015
• Status: Active Grant

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group), Industry Academic Cooperation Foundation
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group), Industry Academic Cooperation Foundation
• Inventors: Kim, Gwan Sik, Cho, Sung Mee, Kim, Byung Wook, Song, Kyong Hwa, Lee, Han Saem, Kwak, Jin Woo, Lyo, In Woong, Noh, Su Jung, Lee, Woo Young
• Granted Patent: US 10,644,214 B2
• Time in Patent Office: Days
• CPC Class Codes: C22C 23/00 Alloys based on magnesium
• CPC Class Codes: H10N 10/01 Manufacture or treatment
• CPC Class Codes: H10N 10/853 comprising arsenic, antimony or bismuth H10N10/852 takes precedence

Abstract

A thermoelectric nanocomposite is provided. The thermoelectric nanocomposite includes: a matrix having n-type semiconductor characteristics and comprising Mg, Si, Al, and Bi components, and a nanoinclusion comprising Bi and Mg components. The thermoelectric nanocomposite has significantly increased thermoelectric energy conversion efficiency by simultaneously having an increased Seebeck coefficient and a decreased thermal conductivity, such that the thermoelectric nanocomposite is usefully used to implement a thermoelectric device having high efficiency.

Claims

1. A thermoelectric nanocomposite, comprising:

a matrix having n-type semiconductor characteristics; and

a nanoinclusion comprising Bi and Mg,

wherein the nanoinclusion is embedded in the matrix.

2. The thermoelectric nanocomposite according to claim 1, wherein the nanoinclusion is Bi₂Mg_3±

z,

where 0≦

z≦

0.1.

3. The thermoelectric nanocomposite according to claim 1, wherein the matrix is Mg_2-xAl_xSi_1-yBi_y,

where 0≦

x≦

0.04, and 0≦

y≦

0.04).

4. The thermoelectric nanocomposite according to claim 1, wherein the matrix is Mg_2-xAl_xSi_1-y-wBi_ySn_w,

where 0≦

x≦

0.04, 0≦

y≦

0.04, and 0≦

w≦

0.5.

5. The thermoelectric nanocomposite according to claim 1, wherein the nanoinclusion has an average particle size of about 1 to 500 nm.

6. The thermoelectric nanocomposite according to claim 1, wherein the nanoinclusion is contained at a content of about 0.1 to 4.0 parts by weight based on 100 parts by weight of the matrix.

7. The thermoelectric nanocomposite according to claim 6, wherein the matrix comprises Mg_1.98Al_0.02Si_0.97Bi_0.03, and the nanoinclusion comprises Bi₂Mg₃, a weight ratio of the nanoinclusion to the matrix being about 2.6%.

8. The thermoelectric nanocomposite according to claim 6, wherein the matrix comprises Mg_1.98Al_0.02Si_0.97Bi_0.04, and the nanoinclusion comprises Bi₂Mg₃, a weight ratio of the nanoinclusion to the matrix being about 4.0%.

9. The thermoelectric nanocomposite according to claim 6, wherein the matrix comprises Mg_1.96Al_0.04Si_0.97Bi_0.03, and the nanoinclusion comprises Bi₂Mg₃, as a weight ratio of the nanoinclusion to the matrix is about 1.7%.

10. The thermoelectric nanocomposite according to claim 6, wherein the matrix comprises Mg_1.96Al_0.04Si_0.96Bi_0.04, and the nanoinclusion comprises Bi₂Mg₃, a weight ratio of the nanoinclusion to the matrix being about 2.4%.

11. The thermoelectric nanocomposite according to claim 1, wherein a density of a phase boundary between the matrix phase and the secondary phase is of about 350 to 4200 cm²/cm³.

12. The thermoelectric nanocomposite according to claim 1, wherein the nanoinclusion has a particle size less than a mean free path of the matrix.

20. A vehicle comprising a thermoelectric nanocomposite of claim 1.

13. A process of producing a thermoelectric nanocomposite comprising:

(a) preparing nanocomposite base material powder; and

(b) sintering the nanocomposite base material powder obtained in step (a) to obtain a thermoelectric nanocomposite.

14. The process of claim 13, wherein the nanocomposite base material powder is prepared by steps comprising:

mixing precursors; and

compacting the mixed precursors at a pressure of 10 to 90 MPa at a temperature of about 10 to 30 to form a pellet; and

heat treating the pellet under vacuum.

15. The process of claim 14 further comprising:

grinding the heated pellet by a ball milling method, an attrition milling method, a high energy milling method, a zet milling method, or a grinding method using a mortar.

16. The process of claim 13, wherein the nanocomposite base material powder obtained in step (a) is sintered by steps comprising :

putting the nanocomposite base material powder obtained in step (a) into a mold having a predetermined shape; and

molding the composite base material powder at a temperature of about 500 to 900°

C., and a pressure of about 30 to 300 MPa.

17. The process of claim 13, wherein the nanocomposite base material powder obtained in step (a) is sintered by steps comprising:

applying a current of about 50 to 500 A at a pressure of about 30 to 300 MPa.

18. The process of claim 13, wherein the nanocomposite base material powder obtained in step (a) is sintered by steps comprising:

applying a temperature of about 500 to 900°

C. to the nanocomposite base material powder obtained in step (a); and

simultaneously sintering and molding the thermoelectric nanocomposite base material powder.

19. The process of claim 13, wherein an inclusion is precipitated in the step (b) of sintering.