Method and device employing heat absorber for limiting battery temperature spikes

• US 7,443,136 B2
• Filed: 01/08/2003
• Issued: 10/28/2008
• Est. Priority Date: 01/09/2002
• Status: Active Grant

• Current Assignee: Quallion, LLC (EnerSys)
• Original Assignee: Quallion, LLC (EnerSys)
• Inventors: Skinlo, David, Dodd, Joanna, Tsukamoto, Hisashi, Kishiyama, Clay
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US10/500,907
• Publication Number:
  US 20050104554A1
• Time in Patent Office: 2,120 Days
• Field of Search: 320/107, 320/112, 320/150, 320/153
• US Class Current: 320/112
• CPC Class Codes: H01M 10/4235 Safety or regulating additives or arrangements in electrodes, separators or electrolyte H01M10/4242 takes precedence
• CPC Class Codes: H01M 10/613 Cooling or keeping cold
• CPC Class Codes: H01M 10/623 Portable devices, e.g. mobile telephones, cameras or pacemakers
• CPC Class Codes: H01M 10/659 by heat storage or buffering, e.g. heat capacity or liquid-solid phase changes or transition
• CPC Class Codes: H01M 2200/10 Temperature sensitive devices
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A method and apparatus for containing heat generated by a battery to reduce the amplitude of a temperature excursion to enhance safety in temperature critical applications, such as in implantable medical devices. The apparatus employs a heat absorber (38) closely thermally coupled to the battery (30). The heat absorber includes heat-absorbing material preferably exhibiting an endothermic phase change at a temperature below that produced by the battery.

Claims

1. An implantable medical device, comprising:

an implantable medical device housing that includes a housing wall of biocompatible material defining an interior volume;

a battery including an electrode assembly housed in a battery case and capable of producing a temperature greater than a temperature T1, the battery mounted within the interior volume; and

heat absorbing material exhibiting a phase change at the temperature T1 and positioned external to the electrode assembly for reducing the amplitude of a temperature excursion of the implantable medical device housing to prevent significant damage to body tissue.

2. The device of claim 1, wherein the heat absorbing material is positioned within the battery case.

3. The device of claim 1, wherein the heat absorbing material is positioned between the battery case and the device housing.

4. The device of claim 3, wherein the battery case has a case wall outer surface, and wherein the heat absorbing material contacts the case wall outer surface.

5. The device of claim 3, further comprising:

an outer casing mounted within the interior volume;

wherein

the battery is mounted within the outer casing; and

the heat absorbing material is contained between the battery case and the outer casing.

6. The device of claim 5, further comprising:

at least a second battery mounted within the outer casing.

7. The device of claim 5, wherein the outer casing is formed of a polymer.

8. The device of claim 3, further comprising:

a caddy containing the heat absorbing material and attached to the battery case.

9. The device of claim 1, further comprising:

a fibrous containment mat embedded in the heat absorbing material.

10. The device of claim 9, wherein the fibrous containment mat includes dielectric fibers.

11. The device of claim 9, wherein the fibrous containment mat includes Kevlar.

12. The device of claim 9, wherein the fibrous containment mat includes fiberglass.

13. The device of claim 1, wherein the heat absorbing material includes paraffin.

14. The device of claim 1, and further including dielectric spacers separating the battery case from the device housing.

15. The device of claim 1, wherein the battery is a rechargeable battery.

16. A device, comprising:

a housing that includes a wall defining an interior housing volume;

a battery including an electrode assembly housed in a battery case and capable of producing a temperature greater than a temperature T1, the battery mounted within the interior volume with the battery case spaced from the housing;

a heat absorber mounted adjacent to and thermally coupled to the battery case, the heat absorber including a heat absorbing material exhibiting a phase change at the temperature T1; and

a fibrous mat contacting the heat absorbing material.

17. The device of claim 16, and further including dielectric spacers separating the battery case from the housing.

18. The device of claim 16, wherein the heat absorbing material is positioned within the battery case.

19. The device of claim 16, wherein the heat absorbing material is positioned between the battery case and the housing.

20. The device of claim 16, wherein the battery case has a case wail outer surface, and wherein the heat absorbing material contacts the case wall outer surface.

21. The device of claim 16, further comprising:

an outer casing mourned within the interior volume;

wherein

the battery is mounted within the outer casing; and

the heat absorbing material is contained between the battery case and the outer casing.

22. The device of claim 21, further comprising:

at least a second battery mounted within the outer casing.

23. The device of claim 21, wherein the outer casing is formed of a polymer.

24. The device of claim 16, wherein the heat absorber includes a caddy containing the heat absorbing material and attached to the battery case.

25. The device of claim 16, wherein the fibrous mat is embedded in the heat absorbing material.

26. The device of claim 25, wherein the fibrous mat includes dielectric fibers.

27. The device of claim 25, wherein the fibrous mat includes Kevlar.

28. The device of claim 25, wherein the fibrous mat includes fiberglass.

29. The device of claim 16, wherein the heat absorbing material includes paraffin.

30. The device of claim 16, wherein the heat absorbing material includes polyethylene.

31. The device of claim 16, wherein the heat absorbing material includes polypropylene.

32. The device of claim 16, wherein the battery is a rechargeable battery.

33. A method for containing heat generated by a battery having a battery case within a housing, comprising:

spacing the battery case from the housing;

providing high heat capacity material in thermal contact with the battery case and spaced from the housing; and

transferring the heat generated from the battery to the high heat capacity material in the form of latent heat of fusion of the high heat capacity material.

34. The method of claim 33, further comprising:

forming an electrode assembly; and

then

mounting the high heat capacity material around the electrode assembly within the battery case and thermally coupled to the electrode assembly.

35. The method of claim 33, further comprising configuring the high heat capacity material to engage the outer surface of the battery case.

36. The method of claim 33, further comprising:

accommodating the high heat capacity material within a caddy; and

mounting the caddy to the outer surface of the battery case.

37. The method of claim 33, further comprising depositing the high heat capacity material on a fibrous mat.