Method of withdrawing heat from a battery pack

• US 8,968,949 B2
• Filed: 03/02/2012
• Issued: 03/03/2015
• Est. Priority Date: 10/28/2008
• Status: Active Grant

• Current Assignee: Tesla Inc.
• Original Assignee: Tesla Motors Incorporated (Tesla Inc.)
• Inventors: Hermann, Weston Arthur, Kohn, Scott Ira, Kelty, Kurt Russell, Kishiyama, Clay Hajime, Paryani, Anil, Jacobs, Alexander Thomas, Cutler, Grant Dufresne, Zhou, Peng
• Primary Examiner(s): Ruddock, Ula C.
• Assistant Examiner(s): GATEWOOD, DANIEL S
• Application Number:
  US13/410,339
• Publication Number:
  US 20120153901A1
• Time in Patent Office: 1,096 Days
• US Class Current: 429/420
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/613 Cooling or keeping cold
• CPC Class Codes: H01M 10/625 Vehicles
• CPC Class Codes: H01M 10/63 Control systems charging or discharging in response to temperature H01M10/44 , H01M10/443; measurement of temperature H01M10/48 , H01M10/486
• CPC Class Codes: H01M 10/647 Prismatic or flat cells, e.g. pouch cells
• CPC Class Codes: H01M 10/653 characterised by electrically insulating or thermally conductive materials
• CPC Class Codes: H01M 10/6553 Terminals or leads
• CPC Class Codes: H01M 10/6554 Rods or plates
• CPC Class Codes: H01M 10/6568 characterised by flow circuits, e.g. loops, located externally to the cells or cell casings
• CPC Class Codes: H01M 10/663 the system being an air-conditioner or an engine
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A method for withdrawing heat from a battery pack is provided, wherein the heat is transferred from at least one electrode of each cell comprising the battery pack, via an electrically and thermally conductive tab, through a current collector plate and through a thermal interface layer to a temperature control panel that is coupled to an external temperature control system.

Claims

1. A method of withdrawing heat from a battery pack, wherein the battery pack is comprised of a plurality of cells, wherein each cell of said plurality of cells is comprised of an individual cell housing containing at least one electrode of a first type and at least one electrode of a second type, wherein each cell of said plurality of cells further comprises a first electrically and thermally conductive tab coupled to the at least one electrode of said first type and a second electrically and thermally conductive tab coupled to the at least one electrode of said second type, and wherein said first and second electrically and thermally conductive tabs extend through the individual cell housing, the first electrically and thermally conductive tab extending on one side of the individual cell housing, and the second electrically and thermally conductive tab extending on another separate side of the individual cell housing, wherein heat conduction in a direction D₁ along an axis of the individual cell housing is substantially larger than heat conduction in a direction D₂ transverse to the individual cell housing, the first electrically and thermally conductive tab having (i) mass that is substantially larger than a mass required to conduct current at a predetermined maximum cell electrical discharge rate and (ii) a size that is substantially larger than a size required to avoid ripping or breaking in use, the method comprising the steps of:

coupling said first electrically and thermally conductive tab of each of said plurality of cells within said battery pack to a first surface of a common current collector plate located on the one side of the battery pack, wherein said common current collector plate is external to each cell of said plurality of cells and external to each individual cell housing corresponding to each cell of said plurality of cells, wherein said common current collector plate is electrically and thermally conductive;

conducting electricity and thermal energy through said first electrically and thermally conductive tab of each of said plurality of cells to said common current collector plate, thereby making use of the different heat conduction in the respective directions D₁ and D₂;

conducting electricity from said plurality of cells through said common current collector plate;

coupling a second surface of said common current collector plate to a first surface of a thermal interface layer, wherein said thermal interface layer is electrically insulating and thermally conducting;

coupling a second surface of said thermal interface layer to a temperature control panel, and wherein said thermal interface layer is interposed between said common current collector plate and said temperature control panel; and

transferring thermal energy from said first electrically and thermally conductive tab of each of said plurality of cells through said common current collector plate and through said thermal interface layer to said temperature control panel.

2. The method of claim 1, wherein the second electrically and thermally conductive tab also has (i) a mass that is substantially larger than a mass required to conduct current at a predetermined maximum cell electrical discharge rate and (ii) a size that is substantially larger than a size required to avoid ripping or breaking in use, the method further comprising the steps of:

coupling said second electrically and thermally conductive tab of each of said plurality of cells within said battery pack to a first surface of a second common current collector plate located on the other side of the battery pack, wherein said second common current collector plate is external to each cell of said plurality of cells and external to each individual cell housing corresponding to each cell of said plurality of cells, wherein said second common current collector plate is electrically and thermally conductive;

conducting electricity and thermal energy through said second electrically and thermally conductive tab of each of said plurality of cells to said second common current collector plate, thereby making use of the different heat conduction in the respective directions D₁ and D₂;

conducting electricity from said plurality of cells through said second common current collector plate;

coupling a second surface of said second common current collector plate to a first surface of a second thermal interface layer, wherein said second thermal interface layer is electrically insulating and thermally conducting;

coupling a second surface of said second thermal interface layer to a second temperature control panel, and wherein said second thermal interface layer is interposed between said second common current collector plate and said second temperature control panel; and

transferring thermal energy from said second electrically and thermally conductive tab of each of said plurality of cells through said second common current collector plate and through said second thermal interface layer to said second temperature control panel.

3. The method of claim 1, further comprising the step of cycling a fluid through at least one lumen within said temperature control panel.

4. The method of claim 3, said step of transferring thermal energy from said first electrically and thermally conductive tab of each of said plurality of cells through said common current collector plate and through said thermal interface layer to said temperature control panel further comprising the step of transferring said thermal energy to said fluid cycling through said at least one lumen within said temperature control panel.

5. The method of claim 3, further comprising the step of adjusting a temperature of said fluid to a specified temperature, wherein said adjusting step is performed by a temperature control system coupled to said temperature control panel.

6. The method of claim 1, further comprising the step of cycling a fluid through at least one heat conductive tube thermally coupled to said temperature control panel.

7. The method of claim 6, said step of transferring thermal energy from said first electrically and thermally conductive tab of each of said plurality of cells through said common current collector plate and through said thermal interface layer to said temperature control panel further comprising the step of transferring said thermal energy to said fluid cycling through said at least one heat conductive tube thermally coupled to said temperature control panel.

8. The method of claim 6, further comprising the step of adjusting a temperature of said fluid to a specified temperature, wherein said adjusting step is performed by a temperature control system coupled to said temperature control panel.

9. The method of claim 1, further comprising the step of selecting a thermal interface material comprising said thermal interface layer from the group consisting of ceramic-filled silicone rubbers and thermal grease.

10. The method of claim 1, further comprising the step of selecting a material comprising said temperature control panel from the group consisting of aluminum, aluminum alloys, copper and copper alloys.

11. The method of claim 1, further comprising the steps of stacking said plurality of cells into a stacked configuration, and aligning said at least one tab of each of said plurality of batteries along a first side of said stacked configuration corresponding to the one side of the battery pack.

12. The method of claim 1, wherein the mass of each of the first and second electrically and thermally conductive tabs is at least 10% larger than the mass required to conduct the current at the predetermined maximum cell electrical discharge rate.

13. The method of claim 12, wherein the mass of each of the first and second electrically and thermally conductive tabs is at least 100% larger than the mass required to conduct the current at the predetermined maximum cell electrical discharge rate.

14. The method of claim 1, wherein at least the first electrically and thermally conductive tabs are non-isotropic.

15. The method of claim 14, wherein the first and second electrically and thermally conductive tabs form a plane, and wherein at least the first electrically and thermally conductive tabs have a thermal conductivity along the plane that differs from a thermal conductivity through the plane.

16. The method of claim 1, wherein the cells are pouch cells.

17. The method of claim 1, wherein the size of the at least one of the first and second electrically and thermally conductive tabs is selected based on a Δ

T that is required.

18. The method of claim 17, wherein, for the at least one of the first and second electrically and thermally conductive tabs, a ratio between (i) a cross sectional area perpendicular to a length of the tab and (ii) the length of the tab is significantly larger than a ratio between (iii) cross sectional area perpendicular to length and (iv) length to conduct electrical energy at the predetermined maximum cell electrical discharge rate.