Vehicle battery pack thermal barrier

• US 8,875,828 B2
• Filed: 02/20/2013
• Issued: 11/04/2014
• Est. Priority Date: 12/22/2010
• Status: Active Grant

• Current Assignee: Tesla Inc.
• Original Assignee: Tesla Motors Incorporated (Tesla Inc.)
• Inventors: Rawlinson, Peter Dore, Herron, Nicholas Hayden, Edwards, Bruce Phillip, Goetchius, Gregory Michael
• Primary Examiner(s): Phan, Hau
• Assistant Examiner(s): MEYER, JACOB B
• Application Number:
  US13/771,471
• Publication Number:
  US 20130153317A1
• Time in Patent Office: 622 Days
• Field of Search: 180/65.1, 180/68.5
• US Class Current: 180/68.5
• 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: B60Y 2306/11 Noise generation, e.g. drive noise to warn pedestrians that an electric vehicle is approaching
• CPC Class Codes: B60Y 2410/114 Shields, e.g. for heat protection
• CPC Class Codes: B62D 25/025 Side sills thereof
• CPC Class Codes: B62D 25/2036 the subunits being side panels, sills or pillars B62D21/157 takes precedence
• CPC Class Codes: B62D 29/008 predominantly of light alloys, e.g. extruded
• CPC Class Codes: F41H 7/042 Floors or base plates for increased land mine protection

Abstract

An integration assembly for a battery pack mounted between the passenger cabin floor panel of an electric vehicle and the driving surface is provided, the assembly utilizing a multi-layer thermal barrier interposed between the battery pack enclosure and the passenger cabin floor panel, where the multi-layer thermal barrier provides noise isolation, thermal isolation and vibration damping, and where the multi-layer thermal barrier is compressed when the battery pack enclosure is mounted to the vehicle. The multi-layer thermal barrier is comprised of a first layer formed from a compressible and conformable elastic material and a second layer formed from a conformable thermally insulating material. The multi-layer thermal barrier may also include a moisture barrier layer that encases the first and second layers, for example a moisture barrier layer fabricated from a plastic. A sealant may be used to seal and bond the moisture barrier layer to the battery pack enclosure.

Claims

1. A vehicle battery pack integrated assembly, comprising:

a battery pack enclosure mounted under an electric vehicle, wherein said battery pack enclosure comprises an enclosure top panel, an enclosure bottom panel, and a plurality of enclosure side members, wherein said battery pack enclosure is configured to hold a plurality of batteries, and wherein said battery pack enclosure is mounted between a passenger cabin floor panel and a driving surface; and

a multi-layer thermal barrier interposed between said battery pack enclosure and said passenger cabin floor panel, wherein said multi-layer thermal barrier provides noise isolation, thermal isolation and vibration damping, wherein said multi-layer thermal barrier is compressed when said battery pack enclosure is mounted to said electric vehicle, and wherein said multi-layer thermal barrier is comprised of;

a first layer, wherein said first layer is comprised of a compressible and conformable elastic material; and

a second layer, wherein said second layer is comprised of a conformable thermally insulating material.

2. The vehicle battery pack integrated assembly of claim 1, wherein said multi-layer thermal barrier has an acoustic insertion loss of greater than 10 dB for frequencies between 1000 Hz and 10 kHz.

3. The vehicle battery pack integrated assembly of claim 1, wherein said multi-layer thermal barrier has an acoustic insertion loss of greater than 20 dB for frequencies between 1000 Hz and 10 kHz.

4. The vehicle battery pack integrated assembly of claim 1, wherein said multi-layer thermal barrier has a damping loss factor of at least 0.1.

5. The vehicle battery pack integrated assembly of claim 1, wherein said multi-layer thermal barrier has a damping loss factor of at least 0.3.

6. The vehicle battery pack integrated assembly of claim 1, wherein said second layer of said multi-layer thermal barrier has a thermal conductivity of less than 0.25 W/m-K at a temperature of 1000°

C.

7. The vehicle battery pack integrated assembly of claim 1, wherein said second layer of said multi-layer thermal barrier has a thermal conductivity of less than 0.15 W/m-K at a temperature of 1000°

C.

8. The vehicle battery pack integrated assembly of claim 1, wherein said second layer of said multi-layer thermal barrier has a thermal conductivity of less than 0.1 W/m-K at a temperature of 1000°

C.

9. The vehicle battery pack integrated assembly of claim 1, wherein said second layer of said multi-layer thermal barrier is capable of withstanding temperatures of more than 1000°

C. continuously.

10. The vehicle battery pack integrated assembly of claim 1, wherein said second layer of said multi-layer thermal barrier is capable of withstanding temperatures of more than 1000°

C. for a period of at least 10 seconds.

11. The vehicle battery pack integrated assembly of claim 1, wherein said first layer of said multi-layer thermal barrier has a compression modulus of at least 1.5 PSI at 25% compression.

12. The vehicle battery pack integrated assembly of claim 1, wherein said second layer of said multi-layer thermal barrier has a compression modulus of at least 1.5 PSI at 25% compression.

13. The vehicle battery pack integrated assembly of claim 1, wherein said first layer of said multi-layer thermal barrier is comprised of a closed cell foam material, wherein said closed cell foam material consists of a material selected from the group consisting of polyurethane, polyethylene, and ethylene propylene diene monomer (EPDM) foam.

14. The vehicle battery pack integrated assembly of claim 1, wherein said second layer of said multi-layer thermal barrier is comprised of a material selected from the group consisting of silica/calcium oxide fibers, silica/calcium oxide/magnesium oxide fibers, basalt fiber based needled pad, silica/silica fibers, alumina, Kevlar®

, and Nomex®

.

15. The vehicle battery pack integrated assembly of claim 1, said multi-layer thermal barrier further comprising a moisture barrier layer that encases said first and second layers of said multi-layer thermal barrier.

16. The vehicle battery pack integrated assembly of claim 15, wherein said moisture barrier layer of said multi-layer thermal barrier is fabricated from a plastic material.

17. The vehicle battery pack integrated assembly of claim 15, wherein said moisture barrier layer of said multi-layer thermal barrier is fabricated from a low-density polyethylene (LDPE) thermoplastic.

18. The vehicle battery pack integrated assembly of claim 15, further comprising a sealant that seals and bonds said moisture barrier layer of said multi-layer thermal barrier to a perimeter of said battery pack enclosure.

19. The vehicle battery pack integrated assembly of claim 1, further comprising a water proof seal interposed between said battery pack enclosure and said electric vehicle.

20. The vehicle battery pack integrated assembly of claim 19, wherein said multi-layer thermal barrier is sealed between said battery pack enclosure and said passenger cabin floor panel by said water proof seal.