System and method for fabrication of high-efficiency durable thermoelectric devices
The present invention relates to a durable high-efficiency thermoelectric device. More specifically, the present invention relates to a thermoelectric device formed with a novel thermoelectric material and system which incorporates a vaporizable scaffolding to create microscopic gaps between the thermoelectric elements which are filled with a high-density, shrink-resistant aerogel.
1 . A durable high-efficiency thermoelectric device comprising a thermoelectric skutterudite device bonded with a strong, low-contact resistance, high-temperature bond on a hot-side interconnect.
2 . The durable high-efficiency thermoelectric device as set forth in claim 1 , wherein the thermoelectric skutterudite device is bonded using a eutectoid reaction of powders selected from the group consisting of titanium and molybdenum (Ti—Mo), titanium-niobium (Ti—Nb), titanium-palladium (Ti—Pd), and titanium-graphite.
3 . The durable high-efficiency thermoelectric device as set forth in claim 1 , wherein the thermoelectric skutterudite device is bonded using a eutectoid reaction of pre-formed plates selected from the group consisting of titanium and molybdenum (Ti—Mo), titanium-niobium (Ti—Nb), titanium-palladium (Ti—Pd), and titanium-graphite.
4 . A method for fabricating durable high-efficiency thermoelectric devices comprising acts of:
inserting a plate into an opening of a graphite die;
pressing a first thermoelectric leg onto the plate through a press hole in the graphite die to create a bond between the first thermoelectric leg and the plate;
removing the plate and now bonded first thermoelectric leg and rotating the plate before reinserting the plate into the graphite die, wherein the first thermoelectric leg is inserted into a relief hole in the graphite die; and
pressing a second thermoelectric leg onto the plate through the press hole to create a bond between the second thermoelectric leg and the plate.
5 . The method as set forth in claim 4 , wherein the thermoelectric skutterudite device is formed using a hot press applying approximately 100 MegaPascals (MPa) of pressure at approximately 700 degrees Celsius (C.).
6 . The method as set forth in claim 4 , wherein the thermoelectric skutterudite device is formed using a plate press applying only approximately 1 MPa of pressure at approximately 700 C.
7 . The method as set forth in claim 4 , wherein the plate is made of molybdenum.
8 . The method as set forth in claim 4 , wherein the first thermoelectric leg is formed of an n-type material.
9 . The method as set forth in claim 8 , wherein the first thermoelectric leg is formed of titanium, n-type skutterudite, titanium powder and nickel powder.
10 . The method as set forth in claim 4 , wherein the second thermoelectric leg is formed of a p-type material.
11 . The method as set forth in claim 10 , wherein the second thermoelectric leg is formed of titanium, cobalt, p-type skutterudite, titanium and nickel.
12 . A high density shrink-resistant aerogel comprising a composite aerogel primarily comprised of an oxide powder to prevent shrinkage during formation in a supercritical drying process.
13 . The high density shrink-resistant aerogel as set forth in claim 12 , wherein the density of the composite aerogel is greater than 100 milligrams per cubic centimeter (mg/cc).
14 . The high density shrink-resistant aerogel as set forth in claim 12 , wherein the composite aerogel is formed from tetraethylorthosilicate (“TEOS”), ethanol, nitric acid, and titania powder.
15 . The high density shrink-resistant aerogel as set forth in claim 14 , wherein the titania powder is comprised roughly micrometer-sized particles.
16 . A method for creating a gap between thermoelectric legs comprising an act of forming a vaporizable scaffold around a portion of a thermoelectric leg during formation of a thermoelectric element, wherein the vaporizable scaffold vaporizes during the formation of the thermoelectric element to create a gap separating a first thermoelectric leg from a second thermoelectric leg, such that the gap can be filled with an insulating material.
17 . The method as set forth in claim 16 , wherein the vaporizable scaffold comprises a polymer.
18 . The method as set forth in claim 17 , wherein the polymer is Poly-a-methylstyrene (“PAMS”).
19 . The method as set forth in claim 16 , wherein the insulating material is an aerogel.