High conductive busbars with ultra-conducting composite of carbon nano-tubes for electric machines
A composite conductor for a vehicle, a propulsion system for a vehicle, and a method of forming a composite busbar for a vehicle. The composite conductor includes a surface, and a first copper tape laminated to the surface. The composite conductor is electrically conductive exhibiting an electrical conductivity of 1.0×10{circumflex over (7)} Siemens per meter (S/m) or greater. The first copper tape includes a layer of carbon nanotubes sandwiched between a first copper layer and a second copper layer. The composite busbar may be connected to a plurality of windings in the stator of an electric motor.
1 . A composite conductor for a vehicle, comprising:
a conductor including a surface, wherein the conductor is electrically conductive exhibiting an electrical conductivity of 1.0×10{circumflex over ( )}7 Siemens per meter (S/m) or greater; and
a first copper tape laminated to the surface, wherein the first copper tape includes a layer of carbon nanotubes sandwiched between a first copper layer and a second copper layer,
wherein the first copper layer comprises a copper foil and the second copper layer comprises a copper coating,
wherein the first copper tape exhibits a thickness in the range of 10 micrometers to 40 micrometers, and
wherein the layer of carbon nanotubes exhibits a thickness in the range of 2 nanometers to 50 nanometers, the copper coating layer exhibits a thickness in the range of 0.1 micrometers to 3 micrometers, and the copper foil provides the remainder of the thickness of the first copper tape.
2 . The composite conductor of claim 1 , wherein the conductor is formed from one or more of the following materials selected from the group consisting of copper, aluminum, and iron.
3 . The composite conductor of claim 1 , further comprising at least one additional carbon nanotube layer disposed on the second copper layer and at least one additional second copper layer disposed on the at least one additional carbon nanotube layer.
4 . The composite conductor of claim 1 , wherein at least one additional copper tape is bonded to the first copper tape bonded to the surface.
5 . The composite conductor of claim 1 , wherein no intermetallic phases are formed at the surface.
6 . The composite conductor of claim 1 , wherein a plurality of conductors are sintered together.
7 . The composite conductor of claim 1 , wherein the conductor is in the form of a busbar.
8 . The composite conductor of claim 7 , wherein the busbar is affixed to a plurality of windings of a stator.
9 . The composite conductor of claim 8 , wherein a rotor is rotatably held in the stator.
10 . The composite conductor of claim 9 , wherein the busbar is affixed to an inverter.
11 . The composite conductor of claim 1 , wherein the electrical conductivity of the conductor is in the range of 1.0×10{circumflex over ( )}7 Siemens per meter (S/m) to 6.04×10{circumflex over ( )}7 Siemens per meter at 20 degrees Celsius and the electrical conductivity of the first copper tape is in the range of 5.5×10{circumflex over ( )}7 Siemens per meter to 6×10{circumflex over ( )}7 Siemens per meter at 20 degrees Celsius.
12 . The conductor of claim 1 , wherein the carbon nanotubes of the first layer of carbon nanotubes are doped with copper at a level in the range of 0.1 volume percent to 50 volume percent of the total volume percent of the carbon nanotubes.
13 . A propulsion system for a vehicle, comprising:
an electric motor, the electric motor including
a stator including a plurality of windings;
a rotor arranged within the stator; and
a composite busbar connected to the plurality of windings, the composite busbar including
a busbar including a surface, the busbar formed of at least one material selected from a group consisting of copper, aluminum, and iron, and
a first copper tape laminated to the surface, wherein the first copper tape includes a layer of carbon nanotubes sandwiched between a first copper foil layer and a second copper coating layer, and wherein the first copper tape exhibits a thickness in the range of 10 micrometers to 40 micrometers, and wherein the carbon nanotube layer exhibits a thickness in the range of 2 nanometers to 50 nanometers, the copper coating layer exhibits a thickness in the range of 0.1 to 3 micrometers, and the copper foil provides the remainder of the thickness of the first copper tape.
14 . The propulsion system of claim 13 , further comprising at least one additional carbon nanotube layer disposed on the second copper coating layer and at least one additional second copper coating layer disposed on the at least one additional carbon nanotube layer.
15 . The propulsion system of claim 13 , wherein at least one additional copper tape is laminated to the first copper tape bonded to the surface.
16 . The propulsion system of claim 13 , wherein the carbon nanotubes of the first layer of carbon nanotubes are doped with copper at a level in the range of 0.1 volume percent to 50 volume percent of the total volume percent of the carbon nanotubes.
17 . A method of forming a composite busbar for a vehicle, comprising:
heating a busbar and a first copper tape, wherein the first copper tape includes a layer of carbon nanotubes sandwiched between a first copper layer and a second copper layer, wherein the first copper layer is a copper foil and the second copper layer is a copper coating, and wherein the first copper tape exhibits a thickness in the range of 10 micrometers to 40 micrometers, wherein the carbon nanotube layer exhibits a thickness in the range of 2 nanometers to 50 nanometers, the copper coating layer exhibits a thickness in the range of 0.1 to 3 micrometers, and the copper foil provides the remainder of the thickness of the first copper tape;
laminating the first copper tape to the busbar by applying a force to the busbar and the first copper tape and bonding the first copper tape to a surface of the busbar; and
heat treating the busbar and first copper tape.
18 . The method of claim 17 , wherein laminating includes thermal rolling of the first copper tape to the surface, wherein the first copper tape exhibits a first length before drawing and a second length in the range of 100 percent to less than 105 percent of the first length.
19 . The method of claim 17 , wherein laminating includes extrusion onto the first copper tape, wherein the first copper tape exhibits a first length before drawing and a second length in the range of 100 percent to less than 105 percent of the first length.
20 . The method of claim 17 , wherein laminating includes hot-isostatic-pressing of the first copper tape to the surface of the busbar.