Battery pack venting system

• US 8,557,415 B2
• Filed: 05/19/2012
• Issued: 10/15/2013
• Est. Priority Date: 04/22/2009
• Status: Active Grant

• Current Assignee: Tesla Inc.
• Original Assignee: Tesla Motors Incorporated (Tesla Inc.)
• Inventors: Herron, Nicholas Hayden, Kohn, Scott Ira, Hermann, Weston Arthur, Leutheuser, Andrew Hill, Weintraub, Jeffrey C., Grace, Dustin, Edwards, Bruce Philip, Verzeni, Nicolas, Mardall, Joseph
• Primary Examiner(s): DOUYETTE, KENNETH J
• Application Number:
  US13/475,955
• Publication Number:
  US 20120231306A1
• Time in Patent Office: 514 Days
• Field of Search: 429/53, 429/82, 429/163, 429/185, 429/54, 429/56, 429/57, 429/148, 320/147, 180/65.1
• US Class Current: 429/53
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 50/64 Constructional details of batteries specially adapted for electric vehicles
• CPC Class Codes: B60L 50/66 Arrangements of batteries
• CPC Class Codes: B60L 58/18 of two or more battery modules
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: B60L 58/26 by cooling
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/625 Vehicles
• CPC Class Codes: H01M 10/653 characterised by electrically insulating or thermally conductive materials
• CPC Class Codes: H01M 10/655 Solid structures for heat exchange or heat conduction
• CPC Class Codes: H01M 10/6556 Solid parts with flow channel passages or pipes for heat exchange closed pipes H01M10/6552
• CPC Class Codes: H01M 10/658 by thermal insulation or shielding
• CPC Class Codes: H01M 2200/10 Temperature sensitive devices
• 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: H01M 50/24 adapted for protecting batteries from their environment, e.g. from corrosion thermal insulation H01M10/658
• CPC Class Codes: H01M 50/342 Non-re-sealable arrangements
• CPC Class Codes: H01M 50/358 External gas exhaust passages located on the battery cover or case
• CPC Class Codes: H01M 50/367 Internal gas exhaust passages forming part of the battery cover or case; Double cover vent systems
• CPC Class Codes: H01M 50/383 : Flame arresting or ignition-preventing means
• CPC Class Codes: H01M 50/394 : Gas-pervious parts or elements
• 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 thermal management system is provided that minimizes the effects of thermal runaway within a battery pack. The system is comprised of a sealed battery pack enclosure configured to hold a plurality of batteries, where the battery pack enclosure is divided into a plurality of sealed battery pack compartments. The system also includes a plurality of battery venting assemblies, where at least one battery venting assembly is integrated into each of the sealed battery pack compartments, and where each of the battery venting assemblies includes an exhaust port integrated into an outer wall of the battery pack compartment and a valve, the valve being configured to seal the exhaust port under normal operating conditions and to unseal the exhaust port when at least one of the batteries within the battery pack compartment enters into thermal runaway.

Claims

1. A battery pack thermal management system, comprising:

a sealed battery pack enclosure configured to hold a plurality of batteries, wherein said sealed battery pack enclosure is divided into a plurality of sealed battery pack compartments, and wherein said plurality of batteries are divided among said plurality of sealed battery pack compartments;

a plurality of battery venting assemblies, wherein at least one of said plurality of battery venting assemblies is integrated into each of said plurality of sealed battery pack compartments, and wherein each of said plurality of battery venting assemblies is comprised of;

an exhaust port integrated into an outer wall of said sealed battery pack compartment; and

a valve, said valve configured to seal said exhaust port under normal operating conditions and unseal said exhaust port when at least one battery contained within said sealed battery pack compartment enters into thermal runaway,

wherein each of said plurality of battery venting assemblies is further comprised of a valve retention carrier, wherein a first portion of said valve is comprised of an exhaust port sealing member, and wherein a second portion of said valve is comprised of a retention member configured to be captured by a valve retention aperture of said valve retention carrier.

2. The battery pack thermal management system of claim 1, wherein said first portion of said valve is umbrella shaped and wherein said second portion of said valve is further comprised of a barbed member configured to be captured by a valve retention carrier aperture of said valve retention carrier.

3. The battery pack thermal management system of claim 1, wherein said valve retention carrier is configured to capture said retention member of multiple valves, said multiple valves corresponding to multiple exhaust ports integrated into said sealed battery pack compartment.

4. The battery pack thermal management system of claim 1, wherein said valve retention carrier is further comprised of a plurality of snap-fit features configured to hold said valve retention carrier in said exhaust port.

5. The battery pack thermal management system of claim 4, wherein said valve retention carrier is mounted to an inside surface of said outer wall of said sealed battery pack compartment, and wherein said exhaust port sealing member of said first portion of said valve seals against an outside surface of said outer wall of said sealed battery pack compartment.

6. The battery pack thermal management system of claim 4, wherein said valve retention carrier is mounted to an outside surface of said outer wall of said sealed battery pack compartment, and wherein said exhaust port sealing member of said first portion of said valve seals against an outer surface of said valve retention carrier.

7. The battery pack thermal management system of claim 6, wherein said valve retention carrier is sealed within said exhaust port.

8. The battery pack thermal management system of claim 6, wherein said valve retention carrier further comprises an o-ring, wherein said o-ring seals said valve retention carrier within said exhaust port.

9. The battery pack thermal management system of claim 1, wherein said valve retention carrier is fabricated from a plastic material.

10. The battery pack thermal management system of claim 1, wherein said valve is fabricated from an elastomeric material.

11. The battery pack thermal management system of claim 1, wherein said valve is fabricated from a fluorosilicone.

12. The battery pack thermal management system of claim 1, wherein said outer wall of said sealed battery pack compartment corresponds to a bottom battery pack enclosure panel.

13. The battery pack thermal management system of claim 1, further comprising an exhaust guide, wherein said exhaust guide is mounted below and external to said sealed battery pack enclosure, wherein said exhaust guide is spaced apart from said exhaust port, and wherein said exhaust guide is configured to direct hot gas and material expelled from within said battery pack compartment to an ambient environment during thermal runaway.

14. The battery pack thermal management system of claim 13, wherein said exhaust guide is configured to direct said hot gas and material expelled from within said battery pack compartment in a direction away from a vehicle centerline during thermal runaway, wherein said vehicle centerline corresponds to a vehicle, wherein said sealed battery pack enclosure is incorporated into said vehicle.

15. The battery pack thermal management system of claim 13, wherein said exhaust guide is comprised of a plurality of exhaust ports, wherein said plurality of exhaust ports are located outboard of said plurality of battery venting assemblies, and wherein said plurality of exhaust ports of said exhaust guide are configured to direct said hot gas and material expelled from within said battery pack compartment in a direction away from a vehicle incorporating said sealed battery pack enclosure.

16. The battery pack thermal management system of claim 15, wherein said plurality of exhaust ports of said exhaust guide are angled away from normal at an angle of between 30 and 60 degrees.

17. The battery pack thermal management system of claim 13, wherein said exhaust guide is fabricated from low carbon steel.

18. The battery pack thermal management system of claim 1, wherein said valve has a cracking pressure in the range of 0.5 to 1.0 psi.

19. The battery pack thermal management system of claim 1, said sealed battery pack enclosure further comprising at least one two-way pressure equalization valve, wherein said two-way pressure equalization valve has a first cracking pressure and said valve of said battery venting assembly has a second cracking pressure, wherein said first cracking pressure is less than said second cracking pressure.

20. The battery pack thermal management system of claim 1, said sealed battery pack enclosure further comprising a plurality of cross-members integrated within said sealed battery pack enclosure, said plurality of cross-members dividing said sealed battery pack enclosure into said plurality of sealed battery pack compartments, and wherein each of said plurality of cross-members presents a thermal barrier to the transfer of thermal energy between said sealed battery pack compartments.

21. The battery pack thermal management system of claim 1, said sealed battery pack enclosure further comprising a central battery pack member and a plurality of cross-members integrated within said sealed battery pack enclosure, wherein said central battery pack member and said plurality of cross-members divide said sealed battery pack enclosure into said plurality of sealed battery pack compartments, and wherein said central battery pack member and each of said plurality of cross-members presents a thermal barrier to the transfer of thermal energy between said sealed battery pack compartments.