Overmolded thermal interface for use with a battery cooling system

• US 8,541,127 B2
• Filed: 05/06/2011
• Issued: 09/24/2013
• Est. Priority Date: 06/18/2007
• Status: Active Grant

• Current Assignee: Tesla Inc.
• Original Assignee: Tesla Motors Incorporated (Tesla Inc.)
• Inventors: Tennessen, Peter Thomas, Weintraub, Jeffrey C., Hermann, Weston Arthur
• Primary Examiner(s): Conley, Helen O
• Application Number:
  US13/102,889
• Publication Number:
  US 20110206969A1
• Time in Patent Office: 872 Days
• Field of Search: 429/120, 429/130, 429/142, 429/129, 429/148
• US Class Current: 429/120
• CPC Class Codes: F28F 1/02 Tubular elements of cross-section which is non-circular F28F1/08, F28F1/10 take precedence
• CPC Class Codes: F28F 13/00 Arrangements for modifying heat-transfer, e.g. increasing, decreasing F28F1/00 - F28F11/00 take precedence
• CPC Class Codes: F28F 2013/005 Thermal joints
• CPC Class Codes: F28F 2255/146 overmolded
• CPC Class Codes: H01M 10/613 Cooling or keeping cold
• CPC Class Codes: H01M 10/615 Heating or keeping warm
• CPC Class Codes: H01M 10/617 for achieving uniformity or desired distribution of temperature
• CPC Class Codes: H01M 10/625 Vehicles
• CPC Class Codes: H01M 10/643 Cylindrical cells
• CPC Class Codes: H01M 10/653 characterised by electrically insulating or thermally conductive materials
• CPC Class Codes: H01M 10/6551 Surfaces specially adapted for heat dissipation or radiation, e.g. fins or coatings
• CPC Class Codes: H01M 10/6557 arranged between the cells
• CPC Class Codes: H01M 10/6567 Liquids
• CPC Class Codes: H01M 10/663 the system being an air-conditioner or an engine
• CPC Class Codes: H01M 50/213 adapted for cells having curved cross-section, e.g. round or elliptic H01M50/209, H01M50/216 take precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A cooling manifold assembly for use in a battery pack thermal management system is provided. The cooling manifold assembly includes a coolant tube that is interposed between at least a first row of cells and a second row of cells, where the first and second rows of cells are adjacent and preferably offset from one another. A thermal interface layer is overmolded onto the cooling tube, the thermal interface layer including a plurality of pliable fingers that extend away from the cooling tube and are interposed between the cooling tube and the first row of cells, and interposed between the cooling tube and the second row of cells, where the pliable fingers are deflected by, and in thermal contact with, the cells of the first and second rows of cells.

Claims

1. A thermal management system for use with a battery pack, the battery pack comprised of a plurality of cells arranged into at least a first row of cells and a second row of cells, wherein said first row of cells is adjacent to said second row of cells, said system comprising:

a cooling manifold assembly interposed between said first and second rows of cells, said cooling manifold assembly comprising;

a coolant tube, said coolant tube including at least one coolant channel, wherein said coolant tube is comprised of a first surface adjacent to said first row of cells and a second surface adjacent to said second row of cells; and

a thermal interface layer overmolded onto said coolant tube, wherein said thermal interface layer is comprised of a plurality of pliable fingers that extend away from said coolant tube, wherein said plurality of pliable fingers are interposed between said first surface of said cooling tube and said first row of cells and between said second surface of said cooling tube and said second row of cells, and wherein said plurality of pliable fingers are deflected by and in thermal contact with said first and second rows of cells.

2. The thermal management system of claim 1, wherein said first row of cells is offset from said second row of cells.

3. The thermal management system of claim 2, wherein said coolant tube is comprised of a first plurality of contours coinciding with said cells of said first row of cells and a second plurality of contours coinciding with said cells of said second row of cells, and wherein said first and second pluralities of contours alternate.

4. The thermal management system of claim 3, wherein a radius of curvature corresponding to each of said first and second pluralities of contours is approximately equal to an outer radius of curvature of said cells.

5. The thermal management system of claim 1, wherein said thermal interface layer is comprised of a material with a dielectric strength of at least 3 kV-mm⁻

1.

6. The thermal management system of claim 1, wherein said thermal interface layer is comprised of a material with a dielectric strength of at least 7 kV-mm⁻

1.

7. The thermal management system of claim 1, wherein said thermal interface layer is comprised of a material with a thermal conductivity of greater than 0.2 W-m⁻

1K<sup>−

1</sup>.

8. The thermal management system of claim 1, wherein said thermal interface layer is comprised of a material with a thermal conductivity of greater than 1.0 W-m⁻

1K<sup>−

1</sup>.

9. The thermal management system of claim 1, wherein said thermal interface layer is comprised of a material with a Shore A hardness value of less than 60.

10. The thermal management system of claim 1, wherein said thermal interface layer is comprised of a material with a tensile strength greater than 5 MPa.

11. The thermal management system of claim 1, wherein a static coefficient of friction between said thermal interface layer and a cell surface is less than 0.3.

12. The thermal management system of claim 1, wherein said thermal interface layer is comprised of a material selected from the group consisting of silicone elastomer blends and thermoplastic elastomers.

13. The thermal management system of claim 1, wherein said cooling tube is fabricated from a metal.

14. The thermal management system of claim 1, wherein said cooling tube is fabricated from a material selected from the group consisting of aluminum, aluminum alloy, steel or copper.

15. The thermal management system of claim 1, wherein said cooling tube has an elongated cross-section, and wherein said first and second surfaces of said cooling tube correspond to elongated side surfaces of said cooling tube.

16. The thermal management system of claim 1, wherein said cooling tube includes a single coolant channel.

17. The thermal management system of claim 1, wherein said cooling tube includes at least a first coolant channel and a second coolant channel.

18. The thermal management system of claim 17, wherein coolant flows in said first coolant channel in a first direction and coolant flows in said second coolant channel in a second direction, wherein said first direction is opposite to said second direction.

19. The thermal management system of claim 1, wherein said cooling manifold assembly is coupled to a vehicle battery cooling system.

20. The thermal management system of claim 1, wherein said plurality of cells are cylindrically shaped.

21. The thermal management system of claim 1, wherein said plurality of pliable fingers are substantially normal to said coolant tube.

22. The thermal management system of claim 1, wherein said plurality of pliable fingers are angled between 30 and 60 degrees off normal.