Tunable frangible battery pack system

• US 7,923,144 B2
• Filed: 03/31/2007
• Issued: 04/12/2011
• Est. Priority Date: 03/31/2007
• Status: Active Grant

• Current Assignee: Tesla Inc.
• Original Assignee: Tesla Motors Incorporated (Tesla Inc.)
• Inventors: Hewett, Brian Charles, Berdichevsky, Gene, Kohn, Scott
• Primary Examiner(s): Ruddock; Ula C
• Assistant Examiner(s): CHUO, TONY SHENG HSIANG
• Application Number:
  US11/731,574
• Publication Number:
  US 20080241667A1
• Time in Patent Office: 1,473 Days
• Field of Search: None
• US Class Current: 429/170
• 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 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 50/64 Constructional details of batteries specially adapted for electric vehicles
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: B60L 58/26 by cooling
• 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 50/227 Organic material
• 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 50/298 characterised by the wiring of battery packs
• CPC Class Codes: H01M 50/503 characterised by the shape of the interconnectors
• CPC Class Codes: H01M 50/522 Inorganic material
• CPC Class Codes: H01M 50/574 Devices or arrangements for the interruption of current
• CPC Class Codes: H01M 50/579 in response to shock
• 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 tunable frangible battery pack system for use in an electric vehicle is disclosed. The tunable frangible battery pack system includes a two piece clamshell housing. The system also includes a plurality of battery cells arranged within the housing and a collector plate secured to each piece of the housing. The system also includes a wire conductor arranged between each of the battery cells and collector plates to create a frangible disconnect system when the battery pack system and electric vehicle are exposed to a predetermined mechanical or thermal force or event.

Claims

1. A battery pack system, said battery pack system comprising:

a plurality of battery cells;

a battery pack housing comprised of a first housing member and a second housing member piece complementary to said first housing member, wherein an internal region defined by a first housing member internal surface and a second housing member internal surface is configured to hold said plurality of battery cells, wherein said first housing member internal surface further comprises a first plurality of counterbores configured to hold a first end portion of said plurality of battery cells, wherein said first housing member internal surface further comprises a first plurality of orifices corresponding to said first plurality of counterbores and coupling said first housing member internal surface to a first housing member external surface, wherein said second housing member internal surface further comprises a second plurality of counterbores configured to hold a second end portion of said plurality of battery cells, wherein said second housing member internal surface further comprises a second plurality of orifices corresponding to said second plurality of counterbores and coupling said second housing member internal surface to a second housing member external surface;

at least one first housing member collector plate arranged on said first housing member external surface, wherein said at least one first housing member collector plate further comprises a third plurality of orifices aligned with said first plurality of orifices, wherein said at least one first housing member collector plate is electrically conductive;

at least one second housing member collector plate arranged on said second housing member external surface, wherein said at least one second housing member collector plate further comprises a fourth plurality of orifices aligned with said second plurality of orifices, wherein said at least one second housing member collector plate is electrically conductive;

a first plurality of frangible conductors electrically connecting said at least one first housing member collector plate and each of said plurality of battery cells, wherein said first plurality of frangible conductors are electrically connected to each of said plurality of battery cells via a first terminal corresponding to each first end portion of said plurality of battery cells; and

a second plurality of frangible conductors electrically connecting said at least one second housing member collector plate and each of said plurality of battery cells, wherein said second plurality of frangible conductors are electrically connected to each of said plurality of battery cells via a second terminal corresponding to each second end portion of said plurality of battery cells.

2. The battery pack system of claim 1 wherein said first and second housing members are made of a plastic material.

3. The battery pack system of claim 1 wherein said at least one first housing member collector plate and said at least one second housing member collector plate are comprised of a material selected from the group consisting of nickel plated aluminum and copper.

4. The battery pack system of claim 1 wherein said first and second pluralities of frangible conductors are configured to break when the battery pack is exposed to a predetermined force or heat.

5. The battery pack system of claim 1 wherein said first and second pluralities of frangible conductors are comprised of an aluminum alloy.

6. The battery pack system of claim 5 wherein said aluminum alloy has a predetermined percentage, by weight, of magnesium and nickel.

7. The battery pack system of claim 6 wherein said magnesium is approximately 0.5% by weight of said aluminum alloy and said nickel constitutes approximately 50 parts per million of said aluminum alloy.

8. The battery pack system of claim 1 wherein said first plurality of frangible conductors are bonded to each of said plurality of battery cells and said at least one first housing member collector plate, and wherein said second plurality of frangible conductors are bonded to each of said plurality of battery cells and said at least one second housing member collector plate.

9. The battery pack system of claim 1 wherein said first plurality of frangible conductors are ultrasonically bonded to each of said plurality of battery cells and said at least one first housing member collector plate, and wherein said second plurality of frangible conductors are ultrasonically bonded to each of said plurality of battery cells and said at least one second housing member collector plate.

10. The battery pack system of claim 1 wherein said first and second pluralities of frangible conductors have a circular cross section or ribbon like shape.

11. The battery pack system of claim 1 further comprising a silicone dielectric gel arranged around said plurality of battery cells.

12. The battery pack system of claim 1 wherein said at least one first housing member collector plate is secured to said first housing member external surface by heat staking or epoxy, wherein said at least one second housing member collector plate is secured to said second housing member external surface by heat staking or epoxy, said at least one first housing member collector plate further comprising a first plurality of recessed areas adjacent to said third plurality of orifices in said at least one first housing member collector plate, said first plurality of frangible conductors electrically connected to said first plurality of recessed areas, said at least one second housing member collector plate further comprising a second plurality of recessed areas adjacent to said fourth plurality of orifices in said at least one second housing member collector plate, said second plurality of frangible conductors electrically connected to said second plurality of recessed areas.