Thermoelectric unicouple used for power generation

• US 6,673,996 B2
• Filed: 05/01/2002
• Issued: 01/06/2004
• Est. Priority Date: 01/17/2001
• Status: Expired due to Fees

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Snyder, Jeffrey, Caillat, Thierry, Zoltan, Leslie, Zoltan, Andrew
• Primary Examiner(s): Ryan, Patrick
• Assistant Examiner(s): Parsons, Thomas H
• Application Number:
  US10/138,040
• Publication Number:
  US 20020189661A1
• Time in Patent Office: 615 Days
• Field of Search: 136/200, 136/201, 136/203, 136/205, 136/236.1, 136/237, 136/239, 136/241, 252/62.3 T
• US Class Current: 136/201
• CPC Class Codes: H10N 10/01 Manufacture or treatment
• CPC Class Codes: H10N 10/17 characterised by the structure or configuration of the cell or thermocouple forming the device
• CPC Class Codes: H10N 10/81 Structural details of the junction
• CPC Class Codes: H10N 10/817 the junction being non-separable, e.g. being cemented, sintered or soldered
• CPC Class Codes: H10N 10/853 comprising arsenic, antimony or bismuth H10N10/852 takes precedence
• CPC Class Codes: H10N 10/854 comprising only metals H10N10/852, H10N10/853 take precedence

Abstract

A high-efficiency thermoelectric unicouple is used for power generation. The unicouple is formed with a plurality of legs, each leg formed of a plurality of segments. The legs are formed in a way that equalizes certain aspects of the different segments. Different materials are also described.

Claims

1. A method, comprising:

forming an n type thermoelectric material part which has a titanium connection part;

forming a p-type thermoelectric material part which has a titanium connection part; and

connecting between the titanium connection parts of the n type thermoelectric material part and the P type thermoelectric material part, to form a contact with a resistance which is less than 5 mc-ohm-cm²;

wherein said forming said n type material and said forming said P type material each comprise obtaining a powder of raw material, forming a flat interface area on said powder, abutting a titanium powder to said flat interface area, and hot pressing said powder, flat interface area and said titanium powder.

2. A method as in claim 1, wherein said connecting uses a Cu₂₂Ag₅₆Zn₁₇Sn₅ type brazing material alloy.

3. A method as in claim 1, wherein said n and p type thermoelectric materials are both skutterudite materials.

4. A method as in claim 3, wherein said materials include P type CeFe₄Sb₁₂ alloys and n type CoSb₃ type alloys.

5. A method as in claim 1, wherein said pressing comprises hot pressing for at least one hour at about 500 degrees C.

6. A method as in claim 5, wherein said pressing comprises pressing in an inert gas atmosphere.

7. A method as in claim 1, wherein said titanium powder is approximately 2 mm thick.

8. A method as in claim 1, wherein said forming an n type leg comprises forming a first leg having at least first and second segments formed of different materials, wherein said first and second segments have different lengths, and each length of each segment is adjusted to provide at least one of a same current and/or a same thermal conductivity across said leg;

and said forming a P type leg comprises forming at least first and second segments formed of different materials and having different lengths, wherein each length of each segment is adjusted to provide at least one of the same current and/or the same thermal conductivity to the segment.

9. A method as in claim 3, wherein each of said n type thermoelectric material parts and said P type thermoelectric material parts are segmented.

10. A method as in claim 9, further comprising operating said unicouple with a 300 degree K cold side and a 975 degree hot side.