Fault tolerant battery cell bypass device and system

Patent metadata

Field	Value
Publication number	US-10050252-B2
Application number	US-201514689488-A
Country	US
Kind code	B2
Filing date	Apr 17, 2015
Priority date	Apr 17, 2015
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

A fault tolerant battery system includes an electrical storage cell having a positive terminal and a negative terminal. The electrical storage cell is provided with a normally open bypass circuit path that is closed in the event of an overdischarged, or open-circuit failure of, the electrical storage cell. The bypass circuit path includes a first electrical conductor connected to the negative terminal of the electrical storage cell, a second electrical conductor connected to the positive terminal of the electrical storage cell, and a shorting gap between the first electrical conductor and the second electrical conductor. The first and second electrical conductors and a non-conductive barrier define an enclosed chamber that encompasses a mass of a fusible material, a spring that is positioned to force the mass of the fusible material into the shorting gap when the mass of the fusible material is at least partially molten, and a heat source is activatable upon the occurrence of the failed electrical storage cell. Two diodes connected in electrical series serve as heat sources, one of which is operable to melt at least a portion of the mass of the fusible material and one of which is operable to heat the conductive web. The chamber entraps the partially molten fusible material such that the spring forces the molten material into the shorting gap, where it closes the shorting gap so that the first electrical conductor is in electrical communication with the second electrical conductor.

First claim

What is claimed is:

1. A battery system comprising:
an electrical storage cell having a positive terminal and a negative terminal;
a normally open bypass circuit path comprising:
a first electrical conductor connected to the negative terminal of the electrical storage cell;
a second electrical conductor connected to the positive terminal of the electrical storage cell; and
a shorting gap between the first electrical conductor and the second electrical conductor,

a mass of electrically conductive fusible material;
first and second diodes electrically connected in series,
each of the first and second diodes having a cathode and an anode, the anode of the first diode being electrically connected to the negative terminal of the electrical storage cell and the cathode of the second diode being electrically connected to the positive terminal of the electrical storage cell,
each of the first and second diodes being heat source activatable upon the occurrence of a voltage reversal of the electrical storage cell, and
the first diode having a sufficient heat output to melt the mass of the fusible material;

a biasing mechanism positioned to force the mass of the fusible material into the shorting gap, when the mass of the fusible material is at least partially molten, thereby closing the shorting gap so that the first electrical conductor is in electrical communication with the second electrical conductor; and
a nonconductive barrier disposed between the first electrical conductor and the second electrical conductor to define a bypass chamber that encloses the mass of fusible material, first and second diodes, biasing mechanism, and shorting gap, wherein the bypass chamber is configured to entrap the mass of the fusible material when it is at least partially molten.

2. The battery system of claim 1 wherein:
the normally open bypass circuit path further comprises an electrically conductive web that it is electrically connected to the second conductor, the web being disposed within the chamber;
the shorting gap is disposed between the web and the first conductor; and
the biasing mechanism is positioned to force the mass of the fusible material into the shorting gap, when the mass of the fusible material is at least partially molten, thereby closing the shorting gap so that the first electrical conductor is in electrical communication with the second electrical conductor via the web.

3. The battery system of claim 2 wherein the second diode has a sufficient heat output to heat the web.

4. The battery system of claim 1 wherein the chamber further encloses an electrically conductive spreader that is disposed between the fusible material and the first diode.

5. The battery system of claim 1 wherein the fusible material is a metal.

6. The battery system of claim 1 wherein the fusible material is a metal alloy.

7. The battery system of claim 1 wherein the fusible material is a lead tin alloy.

8. The battery system of claim 1 wherein the fusible material has a melting point of no more than about 183 degrees C.

9. The battery system of claim 1 wherein the biasing mechanism comprises a spring positioned to move the mass of fusible material toward the shorting gap when the fusible material is at least partially molten.

10. The battery system of claim 1 further comprising a second electrical storage cell in an electrical series relationship.

11. A battery system comprising:
an electrical storage cell having a positive terminal and a negative terminal;
a normally open bypass circuit path comprising:
a first electrical conductor connected to the negative terminal of the electrical storage cell;
a second electrical conductor connected to the positive terminal of the electrical storage cell; and
a shorting gap between the first electrical conductor and the second electrical conductor;

a mass of fusible material;
a heat source activatable upon the occurrence of a voltage reversal of the electrical storage cell, the heat source being operable to melt at least a portion of the mass of the fusible material; and
a biasing mechanism positioned to force the mass of the fusible material into the shorting gap when the mass of the fusible material is at least partially molten, thereby closing the shorting gap so that the first electrical conductor is in electrical communication with the second electrical conductor;
wherein the mass of fusible material, heat source, shorting gap and biasing mechanism are disposed within an enclosed bypass chamber defined by the first electrical conductor, the second electrical conductor, and a nonconductive barrier disposed between the first electrical conductor and the second electrical conductor; and
wherein the bypass chamber is configured to entrap the mass of the fusible material when it is at least partially molten.

12. The battery system of claim 11 wherein:
the normally open bypass circuit path further comprises an electrically conductive web that it is electrically connected to the second conductor within the chamber such that the shorting gap is disposed between the web and the first conductor; and
the biasing mechanism positioned to force the mass of the fusible material into the shorting gap, when the mass of the fusible material is at least partially molten, thereby closing the shorting gap so that the first electrical conductor is in electrical communication with the second electrical conductor via the web.

13. The battery system of claim 11 , wherein the heat source comprises a first diode and a second diode that are electrically connected in series.

14. The battery system of claim 11 wherein the bypass chamber further encloses an electrically conductive spreader that is disposed between the fusible material and the first diode.

15. The battery system of claim 12 wherein:
each of the first and second diodes has a cathode and an anode;
the anode of the first diode is electrically connected to the negative terminal of the electrical storage cell and the cathode of the second diode is electrically connected to the positive terminal of the electrical storage cell;
each of the first and second diodes is a heat source activatable upon the occurrence of a voltage reversal of the electrical storage cell; and
the first diode has a sufficient heat output to melt the mass of the fusible material.

16. The battery of claim 15 wherein the second diode has a sufficient heat output to heat the web.

17. The battery system of claim 11 wherein the fusible material is a metal.

18. The battery system of claim 11 wherein the fusible material is a metal alloy.

19. The battery system of claim 11 wherein the fusible material is a lead tin alloy.

20. The battery system of claim 11 wherein the fusible material has a melting point of no more than about 183 degrees C.

21. The battery system of claim 11 wherein the biasing mechanism comprises a spring positioned to move the mass of fusible material toward the shorting gap when the fusible material is at least partially molten.

22. The battery system of claim 11 further comprising a second electrical storage cell in an electrical series relationship.

23. The battery system of claim 1 wherein the first diode is positioned directly adjacent to the mass of the fusible material.

Assignees

• Boeing Co

Inventors

• Becker-Irvin Craig H
• Powers Allen R

Classifications

• H01M10/425 Primary

  Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing (printed circuits H05K1/00) · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M2220/30

  Batteries in portable systems, e.g. mobile phone, laptop · CPC title

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M2010/4271

  Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing · CPC title