Battery Pack Assembly

• US 20140248515A1
• Filed: 08/13/2012
• Published: 09/04/2014
• Est. Priority Date: 08/15/2011
• Status: Active Grant

• Current Assignee: NeoGraf Solutions, LLC
• Original Assignee: Graftech International Holdings Inc (Graftech International Limited)
• Inventors: Wayne, Ryan J., Taylor, Jonathan Andrew, Smalc, Martin David
• Granted Patent: US 9,774,063 B2
• Time in Patent Office: Days
• US Class Current: 429/82
• CPC Class Codes: H01M 10/613 Cooling or keeping cold
• CPC Class Codes: H01M 10/647 Prismatic or flat cells, e.g. pouch cells
• CPC Class Codes: H01M 10/65 Means for temperature control structurally associated with the cells
• CPC Class Codes: H01M 10/655 Solid structures for heat exchange or heat conduction
• CPC Class Codes: H01M 10/6555 arranged between the cells
• CPC Class Codes: H01M 10/656 characterised by the type of heat-exchange fluid
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A battery pack includes a plurality of cell assemblies each of which include one or more prismatic batteries. A frame has legs sized and configured to be positioned around the prismatic batteries. At least one leg includes a rear face, curved outer edge and a side face. A thermal transfer sheet is made from a sheet of a compressed mass of exfoliated graphite particles. Each thermal transfer sheet is positioned to contact the major surface of the at least one prismatic battery and is bent over the curved outer edge. At least a portion of each thermal transfer sheet is secured between a heat sink and the side face.

Claims

1. A battery pack comprising:

a plurality of cell assemblies each comprising

at least one prismatic battery;

a frame having a plurality of legs sized and configured to be positioned around the at least one prismatic battery, at least one leg including a rear face, curved outer edge and a side face; and

a thermal transfer sheet made from a sheet of flexible graphite, each said thermal transfer sheet being positioned to contact the major surface of the at least one prismatic battery and bent over the curved outer edge; and

a heat sink, at least a portion of each of said thermal transfer sheets being secured between said heat sink and said side face.

2. The battery pack of claim 1 wherein said frame further includes forwardly extending hooked projections and rearwardly extending hook receivers.

3. The battery pack of claim 1 wherein said curved outer edge includes a radius between about 1 mm and about 10 mm.

4. The battery pack of claim 1 wherein said curved outer edge includes a radius of between about 2 mm and about 5 mm.

5. The battery pack of claim 1 wherein said sheet of a compressed mass of exfoliated graphite particles includes an in-plane thermal conductivity of at least about 250 W/mK.

6. The battery pack of claim 1 wherein said sheet of a compressed mass of exfoliated graphite particles includes an in-plane thermal conductivity of at least about 400 W/mK.

7. The battery pack of claim 1 each said cell assembly includes two prismatic batteries.

8. The battery pack of claim 1 wherein said heat sink is made of a thermally conductive metal and includes fins.

9. The battery pack of claim 1 wherein said heat sink comprises a manifold through which a thermal transfer medium flows.

10. The battery pack of claim 1 wherein two opposed legs of said frame include said curved outer edge.

11. The battery pack of claim 1 wherein the radius of said curved outer edge is greater than the minimum bend radius of said thermal transfer sheet that would cause cracking.

12. A battery pack comprising:

a plurality of cell assemblies each comprising

at least one prismatic battery having opposed major surfaces;

a frame having a plurality of legs sized and configured to be positioned around the at least one prismatic battery;

a fluid conduit extending along at least one of said plurality of legs; and

a thermal transfer sheet made from a sheet of flexible graphite and having opposed major surfaces, said thermal transfer sheet having a central portion and at least one tab, one major surface of said central portion contacting at least one of said major surfaces of the at least one prismatic battery and the other of said major surface being at least partially covered by said at least one tab folded over said fluid conduit.

13. The battery pack of claim 12 wherein said frame further includes forwardly extending hooked projections and rearwardly extending hook receivers.

14. The battery pack of claim 12 wherein said thermal transfer sheet comprises three tabs, each said tab being wrapped around said fluid conduit.

15. The battery pack of claim 12 wherein said one or more tabs cover substantially the entire major surface area of one side of said central portion.

16. The battery pack of claim 12 wherein said sheet of flexible graphite includes an in-plane thermal conductivity of at least about 400 W/mK.

17. The battery pack of claim 12 each said cell assembly includes two prismatic batteries.

18. The battery pack of claim 12 wherein said sheet of flexible graphite comprises compressed expanded particles of natural graphite.

19. The battery pack of claim 12 wherein said sheet of flexible graphite comprises graphitized polyimide film.

20. The battery pack of claim 12 wherein at least one of said plurality of legs includes a channel configured to at least partially receive said conduit.

21. The battery pack of claim 12 wherein said conduit is generally U-shaped and extends along at least three of said plurality of legs.