Battery pack enclosure with controlled thermal runaway release system

• US 20100273034A1
• Filed: 03/30/2010
• Published: 10/28/2010
• Est. Priority Date: 04/22/2009
• Status: Active Grant

• Current Assignee: Tesla Inc.
• Original Assignee: Tesla Motors Incorporated (Tesla Inc.)
• Inventors: Mehta, Vineet Haresh, Hermann, Weston Arthur, Prilutsky, Alex
• Granted Patent: US 8,277,965 B2
• Time in Patent Office: Days
• US Class Current: 429/62
• CPC Class Codes: B60K 1/04 of the electric storage means for propulsion exchanging batteries for electric propulsion of vehicles B60L53/80; for auxiliary purposes only B60R16/04; supplying batteries to, or removing batteries from, vehicles B60S5/06
• CPC Class Codes: B60K 2001/0438 Arrangement under the floor
• CPC Class Codes: B60L 50/64 Constructional details of batteries specially adapted for electric vehicles
• 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 10/658 by thermal insulation or shielding
• CPC Class Codes: H01M 2200/10 Temperature sensitive devices
• CPC Class Codes: H01M 50/186 characterised by the disposition of the sealing members
• 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 50/224 Metals
• 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 50/249 specially adapted for aircraft or vehicles, e.g. cars or trains constructional details of batteries specially adapted for electric vehicles B60L50/64
• CPC Class Codes: H01M 50/276 Inorganic material
• CPC Class Codes: H01M 50/342 Non-re-sealable arrangements
• CPC Class Codes: H01M 50/3425 in the form of rupturable membranes or weakened parts, e.g. pierced with the aid of a sharp member
• 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: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A battery pack thermal management system is provided that is comprised of at least one enclosure failure port integrated into at least one wall of a battery pack enclosure, where the enclosure failure port(s) remains closed during normal operation of the battery pack, and opens during a battery pack thermal runaway event, thereby providing a flow path for hot gas generated during the thermal runaway event to be exhausted out of the battery pack enclosure in a controlled fashion.

Claims

1. A battery pack thermal management system, comprising:

a battery pack enclosure configured to hold a plurality of batteries, wherein said battery pack enclosure is comprised of a high temperature material; and

an enclosure failure port integrated into a wall of said battery pack enclosure, wherein said enclosure failure port remains closed during normal operation of said battery pack, and wherein said enclosure failure port opens during a battery pack thermal runaway event and provides a flow path for exhausting hot gas from within said battery pack enclosure.

2. The battery pack thermal management system of claim 1, wherein said high temperature material is comprised of a metal with a melting temperature greater than 800°

C.

3. The battery pack thermal management system of claim 1, wherein said high temperature material is comprised of a metal with a melting temperature greater than 1000°

C.

4. The battery pack thermal management system of claim 1, wherein said high temperature material is comprised of at least an outer layer and an inner layer, wherein said inner layer is comprised of a ceramic.

5. The battery pack thermal management system of claim 4, wherein said ceramic inner layer prevents said outer layer from melting during said battery pack thermal runaway event.

6. The battery pack thermal management system of claim 1, wherein said high temperature material is comprised of at least an outer layer and an inner layer, wherein said inner layer is comprised of an intumescent material.

7. The battery pack thermal management system of claim 6, wherein said intumescent material inner layer prevents said outer layer from melting during said battery pack thermal runaway event.

8. The battery pack thermal management system of claim 1, wherein said battery pack enclosure further comprises:

a first housing member configured to hold said plurality of batteries;

a second housing member configured to be coupled to said first housing member; and

means to secure said first housing member to said second housing member.

9. The battery pack thermal management system of claim 8, wherein said battery pack enclosure further comprises a sealing gasket configured to fit between a first sealing surface corresponding to said first housing member and a second sealing surface corresponding to said second housing member, said sealing gasket further configured to be interposed between said first and second sealing surfaces when said first housing member is secured to said second housing member.

10. The battery pack thermal management system of claim 9, wherein said sealing gasket includes a first portion comprised of a first gasket material with a first melting temperature, and wherein said sealing gasket includes a second portion comprised of a second gasket material with a second melting temperature, wherein said second melting temperature is less than said first melting temperature, and wherein said enclosure failure port is comprised of said second portion of said sealing gasket.

11. The battery pack thermal management system of claim 1, wherein said enclosure failure port opens when an internal battery pack temperature exceeds a preset temperature.

12. The battery pack thermal management system of claim 1, wherein said enclosure failure port opens when an internal battery pack temperature exceeds a preset temperature and an internal battery pack pressure exceed a preset pressure.

13. The battery pack thermal management system of claim 1, wherein said enclosure failure port further comprises:

a cover attached to said wall of said battery pack enclosure, wherein said cover covers a port within said wall of said battery pack enclosure; and

a sealant, wherein said sealant attaches said cover to said wall of said battery pack enclosure, and wherein said sealant fails during said battery pack thermal runaway event and allows detachment of said cover from said wall.

14. The battery pack thermal management system of claim 1, wherein said enclosure failure port is comprised of a region of said wall that is thinner than a surrounding portion of said wall that surrounds said region, wherein said region of said wall fails during said battery pack thermal runaway event and allows hot gas from within said battery pack enclosure to exhaust through said failed region.

15. The battery pack thermal management system of claim 1, wherein said enclosure failure port is comprised of a region of said wall that is surrounded by scoring, wherein said region of said wall fails during said battery pack thermal runaway event and allows hot gas from within said battery pack enclosure to exhaust through said failed region.

16. The battery pack thermal management system of claim 1, wherein said enclosure failure port further comprises:

a cover attached to said wall of said battery pack enclosure, wherein said cover covers a port within said wall of said battery pack enclosure, wherein said cover is comprised of a material with a lower melting point than said high temperature material of said wall of said battery pack enclosure, and wherein said lower melting point temperature corresponds to a temperature associated with said battery pack thermal runaway event; and

means for attaching said cover to said wall of said battery pack enclosure.

17. The battery pack thermal management system of claim 16, wherein said means for attaching said cover to said wall is comprised of a material selected from the group consisting of bonding materials, solder materials, and welding materials.

18. The battery pack thermal management system of claim 16, wherein said means for attaching said cover to said wall is comprised of a plurality of fasteners.

19. The battery pack thermal management system of claim 1, wherein said enclosure failure port further comprises:

a cover attached to said wall of said battery pack enclosure, wherein said cover covers a port within said wall of said battery pack enclosure; and

a plurality of bolting members, wherein said plurality of bolting members attaches said cover to said wall of said battery pack enclosure, and wherein said plurality of bolting members fail during said battery pack thermal runaway event and allow detachment of said cover from said wall.

20. The battery pack thermal management system of claim 1, wherein said enclosure failure port is comprised of a pressure relief valve configured to fail during said battery pack thermal runaway event and allow hot gas from within said battery pack enclosure to exhaust through said failed pressure relief valve.

21. The battery pack thermal management system of claim 1, wherein said enclosure failure port is comprised of an electrical connector configured to fail during said battery pack thermal runaway event and allow hot gas from within said battery pack enclosure to exhaust through said failed electrical connector.

22. The battery pack thermal management system of claim 1, wherein said enclosure failure port is comprised of a coolant connector configured to fail during said battery pack thermal runaway event and allow hot gas from within said battery pack enclosure to exhaust through said failed coolant connector.

23. The battery pack thermal management system of claim 1, wherein said enclosure failure port is configured to preferentially fail along a first portion of said enclosure failure port, wherein said preferential failure directs said hot gas out of said battery pack enclosure in a preferred exhaust direction.

24. The battery pack thermal management system of claim 1, further comprising a heat resistant channel, wherein an entrance of said heat resistant channel is proximate to said enclosure failure port, and wherein during said battery pack thermal runaway event hot gas is exhausted out of said enclosure failure port and into said entrance of said heat resistant channel.

25. The battery pack thermal management system of claim 24, wherein said battery pack enclosure is mounted to a vehicle, wherein said hot gas exhausted through said enclosure failure port during said thermal runaway event passes through said heat resistant channel, and wherein an exit port of said heat resistant channel directs said hot gas away from a vehicle passenger compartment.

26. The battery pack thermal management system of claim 24, wherein said heat resistant channel utilizes an open channel design.

27. The battery pack thermal management system of claim 24, wherein said heat resistant channel utilizes a closed channel design.

28. The battery pack thermal management system of claim 1, wherein said battery pack enclosure is mounted to a vehicle, wherein said battery pack thermal management system further comprises at least one layer of a thermal insulator positioned between said battery pack enclosure and a vehicle passenger compartment.

29. The battery pack thermal management system of claim 1, wherein said battery pack enclosure is mounted to a vehicle, wherein said battery pack thermal management system further comprises at least one layer of a fire retardant material positioned between said battery pack enclosure and a vehicle passenger compartment.

30. The battery pack thermal management system of claim 29, wherein said fire retardant material is comprised of an intumescent material.