Safety method, device and system for an energy storage device

• US 6,531,847 B1
• Filed: 11/07/2001
• Issued: 03/11/2003
• Est. Priority Date: 11/07/2001
• Status: Expired due to Fees

• Current Assignee: Quallion, LLC (EnerSys)
• Original Assignee: Quallion, LLC (EnerSys)
• Inventors: Tsukamoto, Hisashi, Kishiyama, Clay
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US10/014,757
• Time in Patent Office: 489 Days
• Field of Search: 320/118, 320/124, 320/125, 320/127, 320/129, 320/131, 320/132, 320/135, 320/136, 320/150, 320/155, 320/161, 320/164, 320/147
• US Class Current: 320/135
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/446 Initial charging measures
• CPC Class Codes: H01M 2200/00 Safety devices for primary or secondary batteries
• CPC Class Codes: H01M 2200/10 Temperature sensitive devices
• CPC Class Codes: H01M 2200/20 Pressure-sensitive devices
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/00308 Overvoltage protection
• CPC Class Codes: H02J 7/00309 Overheat or overtemperature protection
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A method, device and system is disclosed for rapidly and safely discharging remaining energy stored in an electrochemical battery 104 in the event of an internal short circuit or other fault. In its best mode of implementation, if a sensor 116 detects one or more parameters such as battery temperature 204 or pressure 206, exceeding a predetermined threshold value 334, the terminals 144 of the battery or cell are intentionally short-circuited external to the battery through a low or near zero resistance load 150 which rapidly drains energy from the battery 104. The rate energy is drained via the external discharge load 150 may be controlled with an electronic circuit 136 responsive to factors such as state of charge and battery temperature. Devices such as piezoelectric and Peltier devices 300, may also be used as emergency energy discharge loads.

Claims

1. A method for rapidly discharging stored energy from an energy storage device comprising:

providing at least one said energy storage device,

monitoring operating states of said energy storage device,

setting safety threshold parameters for said operating states,

comparing said operating states to said safety threshold parameters,

determining whether one or more said operating states exceeds at least one said safety threshold parameter,

responsive to said determining that said one or more operating states exceeds at least one said safety threshold parameter, initiating an emergency discharge of energy stored in said energy storage device to safely discharge stored energy.

2. The method claimed in claim 1 therein said energy storage device is a battery.

3. The method as claimed in claim 1 where said operating states includes at least one of the following:

voltage,

change in voltage,

rate of change in voltage,

current,

change in current,

rate of change in current,

state of charge,

change in state of charge,

rate of change in state of charge,

temperature,

change in temperature,

rate of change in temperature,

impedance,

change in impedance,

rate of change in impedance,

pressure,

change in pressure,

rate of change in pressure,

electrolyte pH,

electrolyte specific gravity,

amount of bulging of battery enclosure,

change in bulging of battery enclosure,

and rate of change of bulging of battery enclosure.

4. The method as claimed in claim 1 wherein said emergency discharge of said stored energy is accomplished by converting said stored energy from one form of energy into another form of energy.

5. The method of claim 4 wherein said discharge of energy is accomplished by converting said stored energy from electrical to one or more of the following energy forms:

heat, electromagnetic radiation, kinetic or potential, chemical.

6. The method claimed in claim 1 wherein said determining whether one or more said operating states exceeds said safety threshold condition parameter is carried out according to an algorithm.

7. The method as claimed in claim 6 wherein said algorithm includes one or more of the following logical steps:

If P₁≧

T₁ then initiate emergency energy dump

Where P₁ is a said operating parameter, and

T₁ is a said safety threshold.

8. The method as claimed in claim 7 wherein P₁ and T₁ are parameters including at least one of the following:

voltage,

change in voltage,

rate of change in voltage,

current,

change in current,

rate of change in current,

state of charge,

change in state of charge,

rate of change in state of charge,

temperature,

change in temperature,

rate of change in temperature,

impedance,

change in impedance,

rate of change in impedance,

pressure,

change in pressure,

rate of change in pressure,

electrolyte pH,

electrolyte specific gravity,

amount of bulging of battery enclosure,

change in bulging of battery enclosure,

and rate of change of bulging of battery enclosure.

9. The method of claim 6 wherein said algorithm includes one or more of the following logical steps:

If P₁≦

T₁ then initiate emergency energy dump

Where P₁ is a said operating parameter, and

T₁ is a said safety threshold.

10. The method as claimed in claim 9 wherein P₁ and T₁ are parameters including at least one of the following:

voltage,

change in voltage,

rate of change in voltage,

current,

change in current,

rate of change in current,

state of charge,

change in state of charge,

rate of change in state of charge,

temperature,

change in temperature,

rate of change in temperature,

impedance,

change in impedance,

rate of change in impedance,

pressure,

change in pressure,

rate of change in pressure,

electrolyte pH,

electrolyte specific gravity,

amount of bulging of battery enclosure,

change in amount of bulging of battery enclosure,

and rate of change of amount of bulging of battery enclosure.

11. The method as claimed in claim 1 wherein the rate of discharge of energy from said energy storage device is controlled by a predetermined algorithm.

12. The method of claim 11 wherein said predetermined algorithm includes at least on of the following parameters:

voltage,

change in voltage,

rate of change in voltage,

current,

change in current,

rate of change in current,

state of charge,

change in state of charge,

rate of change in state of charge,

temperature,

change in temperature,

rate of change in temperature,

impedance,

change in impedance,

rate of change in impedance,

pressure,

change in pressure,

rate of change in pressure,

electrolyte pH,

electrolyte specific gravity,

amount of bulging of battery enclosure,

change in amount of bulging of battery enclosure,

and rate of change of amount of bulging of battery enclosure.

13. The method of claim 11 wherein said rate of discharge of energy is directly proportional to the quantity of energy remaining in said storage device.

14. The method of claim 11 wherein said rate of discharge of energy is inversely proportional to the quantity of energy remaining in said storage device.

15. The method claimed in claim 1 further including the step of initiating a notification signal when said one or more said operating states exceeds said safety threshold condition parameters.

16. An emergency energy discharge system comprising:

at least one energy storage device,

at least one detecting device for monitoring one or more operating parameters of said energy storage device,

means for storing predetermined safety threshold values for operating parameters of said energy storage device,

comparison means for comparing said predetermined safety threshold values with said operating parameters,

decision means for determining whether said operating parameters exceed one or more said predetermined operating threshold values,

activation means responsive to decision means,

energy discharge device for discharging said energy stored in said energy storage device so as to render said energy storage device safe before the fault or faults causing the said monitored operating parameters to exceed said safety threshold values renders the energy storage device unsafe, and at such a rate as to not itself become a safety hazard.

17. The emergency energy discharge system claimed in claim 16 wherein said decision means comprises a human operator.

18. The emergency energy discharge system as claimed in claim 16 wherein said decision means comprises a mechanical device.

19. The emergency energy discharge system as claimed in claim 18 wherein said mechanical device comprises a thermal switch.

20. The emergency energy discharge system as claimed in claim 18 wherein said mechanical device comprises a pressure switch.

21. The emergency energy discharge system as claimed in claim 16 wherein said decision means comprises:

an electronic circuit further comprising,

an electronic data storage device,

an electronic computing device,

a decision algorithm stored in said electronic data storage device,

an output signal generating device responsive to said decision algorithm.

22. The emergency energy discharge system as claimed in claim 21 wherein said electronic data storage device comprises an integrated circuit.

23. The emergency energy discharge system claimed in claim 21 wherein said electronic computing device comprises an integrated circuit.

24. The emergency energy discharge system claimed in claim 21 wherein said decision algorithm comprises the following steps:

if C₁≧

T₁ then initiate emergency energy discharge,

where if C₁ is an operating condition, and

T₁ is a triggering safety threshold.

25. The emergency energy discharge system claimed in claim 24 wherein said variables C₁ and T₁ represent at least one of the following:

voltage,

change in voltage,

rate of change in voltage,

current,

change in current,

rate of change in current,

state of charge,

change in state of charge,

rate of change in state of charge,

temperature,

change in temperature,

rate of change in temperature,

impedance,

change in impedance,

rate of change in impedance,

pressure,

change in pressure,

rate of change in pressure,

electrolyte pH,

electrolyte specific gravity,

amount of bulging of battery enclosure,

change in amount of bulging of battery enclosure,

and rate of change of amount of bulging of battery enclosure.

26. The emergency energy discharge system claimed in claim 21 wherein said decision algorithm comprises the following steps:

if C₁≦

T₁ then initiate emergency energy discharge,

where if C₁ is an operating condition, and

T₁ is a triggering safety threshold.

27. The emergency energy discharge system claimed in claim 26 wherein said variables C₁ and T₁ represent at least one of the following:

voltage,

change in voltage,

rate of change in voltage,

current,

change in current,

rate of change in current,

state of charge,

change in state of charge,

rate of change in state of charge,

temperature,

change in temperature,

rate of change in temperature,

impedance,

change in impedance,

rate of change in impedance,

pressure,

change in pressure,

rate of change in pressure,

electrolyte pH,

electrolyte specific gravity,

amount of bulging of battery enclosure,

change in amount of bulging of battery enclosure,

and rate of change of amount of bulging of battery enclosure.

28. The emergency energy discharge system claimed in claim 16 further including a signaling device to produce an alerting signal when said emergency energy discharge is activated.

29. The emergency energy discharge system claimed in claim 16 further comprising a means for controlling the rate of said energy discharge.

30. The emergency energy discharge system claimed in claim 29 wherein said controlled rate of said energy discharge is proportional to energy remaining in said battery.

31. The emergency energy discharge system claimed in claim 29 wherein said controlled rate of said energy discharge is inversely proportional to energy remaining in said battery.

32. The emergency energy discharge system claimed in claim 29 wherein said controlled rate of said energy discharge is a function of one or more of the following battery parameters:

voltage,

change in voltage,

rate of change in voltage,

current,

change in current,

rate of change in current,

state of charge,

change in state of charge,

rate of change in state of charge,

temperature,

change in temperature,

rate of change in temperature,

impedance,

change in impedance,

rate of change in impedance,

pressure,

change in pressure,

rate of change in pressure,

electrolyte pH,

electrolyte specific gravity,

amount of bulging of battery enclosure,

change in amount of bulging of battery enclosure,

and rate of change of amount of bulging of battery enclosure.

33. The emergency energy discharge system claimed in claim 29 wherein said rate of said energy discharge is controlled by varying the resistance of said energy discharge means.

34. The emergency energy discharge system claimed in claim 29 wherein said rate of said energy discharge is controlled by pulsing said energy discharge.

35. An emergency electrical energy discharge circuit comprising:

at least one electrical storage device,

at least one sensor for monitoring one or more operating parameters of said electrical storage device,

a device for communicating said parameters monitored by said sensor,

memory storage containing predetermined safety thresholds for operating parameters of said electrical storage device,

comparison circuit for comparing said predetermined safety thresholds with said operating parameters,

decision means for determining whether said operating parameters exceed one or more said predetermined operating thresholds stored in said memory storage,

one or more switches responsive to said decision means,

one or more energy discharge devices for discharging said energy stored in said electrical storage device at a rate rapid enough to render said electrical energy storage device safe before the fault or faults causing the said monitored operating parameters to exceed said safety thresholds renders the electrical energy storage device unsafe, and at such a rate as to not itself become a safety hazard.

36. The emergency energy discharge circuit claimed in claim 35 wherein said energy storage device is a battery.

37. The emergency energy discharge circuit claimed in claim 35 wherein said decision means is a human operator.

38. The emergency energy discharge circuit as claimed in claim 35 wherein said decision means is a mechanical device.

39. The emergency energy discharge circuit as claimed in claim 35 wherein said mechanical device is a temperature-activated switch.

40. The emergency energy discharge circuit as claimed in claim 35 wherein said mechanical device is a pressure-activated switch.

41. The emergency energy discharge circuit as claimed in claim 35 wherein said operating parameters includes at least one of the following:

voltage,

change in voltage,

rate of change in voltage,

current,

change in current,

rate of change in current,

state of charge,

change in state of charge,

rate of change in state of charge,

temperature,

change in temperature,

rate of change in temperature,

impedance,

change in impedance,

rate of change in impedance,

pressure,

change in pressure,

rate of change in pressure,

electrolyte pH,

electrolyte specific gravity,

amount of bulging of battery enclosure,

change in amount of bulging of battery enclosure,

and rate of change of amount of bulging of battery enclosure.

42. The emergency energy discharge circuit as claimed in claim 35 wherein said decision means comprises,

an electronic circuit further comprising,

data memory storage,

a computing device,

a decision algorithm stored in said data memory storage,

an output signal generating device responsive to said decision algorithm.

43. The emergency electrical energy discharge circuit as claimed in claim 42 wherein said data memory storage includes an integrated circuit.

44. The emergency electrical energy discharge circuit claimed in claim 42 wherein said computing device comprises at least one integrated circuit.

45. The emergency electrical energy discharge circuit claimed in claim 35 further including a signaling device to produce an alerting signal when said emergency energy discharge is activated.

46. The emergency electrical energy discharge circuit claimed in claim 35 for use in the event of penetration of said electrical storage device by an electrically-conducting object.

47. The emergency energy discharge circuit claimed in claim 35 further comprising a means for controlling the rate of said energy discharge.

48. The emergency energy discharge circuit claimed in claim 47 wherein said controlled rate of said energy discharge is proportional to energy remaining in said battery.

49. The emergency energy discharge circuit claimed in claim 47 wherein said controlled rate of said energy discharge is inversely proportional to energy remaining in said battery.

50. The emergency energy discharge circuit claimed in claim 47 wherein said controlled rate of said energy discharge is a function of one or more of the following battery parameters:

voltage,

change in voltage,

rate of change in voltage,

current,

change in current,

rate of change in current,

state of charge,

change in state of charge,

rate of change in state of charge,

temperature,

change in temperature,

rate of change in temperature,

impedance,

change in impedance,

rate of change in impedance,

pressure,

change in pressure,

rate of change in pressure,

electrolyte pH,

electrolyte specific gravity,

amount of bulging of battery enclosure,

change in amount of bulging of battery enclosure,

and rate of change of amount of bulging of battery enclosure.

51. A battery safety circuit comprising:

one or more first electrochemical cells;

at least one sensor monitoring at least one of the following conditions of said one or more first electrochemical cells;

voltage,

change in voltage,

rate of change in voltage,

current,

change in current,

rate of change in current,

state of charge,

change in state of charge,

rate of change in state of charge,

temperature,

change in temperature,

rate of change in temperature,

impedance,

change in impedance,

rate of change in impedance,

pressure,

change in pressure,

rate of change in pressure,

electrolyte pH,

electrolyte specific gravity,

amount of bulging of battery enclosure,

change in amount of bulging of battery enclosure, and

rate of change of amount of bulging of battery enclosure;

memory storage;

predetermined safety thresholds for said at least one condition;

a comparator circuit;

a control circuit;

a diverter switch device;

an energy discharge load;

said comparator circuit comparing said monitored conditions with said stored predetermined safety thresholds and signaling said control circuit whenever said at least one monitored condition exceeds one or more said predetermined thresholds;

said control circuit sending an emergency energy discharge signal to said diverter switch device in response to signal from said comparator circuit;

said diverter switch device causing electrodes of said one or more cells having conditions exceeding said predetermined thresholds to be connected to said energy discharge load.

52. The battery safety circuit as claimed in claim 51 wherein said switch is one or more of the following:

electromechanical relay,

transistor,

semiconductor.

53. The battery safety circuit as claimed in claim 51 wherein said energy discharge load comprises one or more of the following:

resistor,

potentiometer,

capacitor,

lamp,

second electrochemical cell,

electrolytic device,

resistive coil,

inductive coil,

Peltier device,

thermocouple,

thermopile,

piezoelectric device,

sound generating device,

motor,

electromagnet,

phase-change material,

ceramic material,

semiconductor.

54. The battery safety circuit as claimed in claim 51 wherein said memory storage comprises an integrated circuit.

55. The battery safety circuit as claimed in claim 51 wherein said first electrochemical cells are rechargeable.

56. The battery safety circuit as claimed in claim 51 wherein said diverter switch is variable and responsive to said safety circuit which varies said rate at which energy is discharged by controlling said diverter switch.

57. The battery safety circuit as claimed in claim 51 wherein said energy discharge load is a variable resistor controlled by said control circuit such that said rate at which energy is discharged is controlled by varying the resistive load of said energy discharge load in response to said control circuit.

58. The battery safety circuit as claimed in claim 51 wherein said energy discharge load is a variable capacitor controlled by said control circuit such that said rate at which energy is discharged is controlled by varying inductance of said energy discharge load in response to said control circuit.

59. The battery safety circuit as claimed in claim 51 wherein said energy discharge load is a variable transformer controlled by said control circuit such that said rate at which energy is discharged is controlled by varying impedance of said energy discharge load in response to said control circuit.

60. The battery safety circuit as claimed in claim 51 further including an alerting signal device responsively controlled by said control circuit to issue an alerting signal when said emergency energy discharge is activated.

61. The battery safety circuit as claimed in claim 51 wherein said control circuit varies said discharge rate by repeatedly pulsing said diverter switch on and off.

62. An implantable battery comprising:

one or more electrochemical cells;

a charging circuit;

a charging control circuit;

an implanted electronic device receiving its power from said one or more electrochemical cells;

an emergency energy discharge circuit further comprising at least one sensor monitoring at least one of the following conditions of said electrochemical cells;

voltage,

change in voltage,

rate of change in voltage,

current,

change in current,

rate of change in current,

state of charge,

change in state of charge,

rate of change in state of charge,

temperature,

change in temperature,

rate of change in temperature,

impedance,

change in impedance,

rate of change in impedance,

pressure,

change in pressure,

rate of change in pressure,

electrolyte pH,

electrolyte specific gravity,

amount of bulging of battery enclosure,

change in amount of bulging of battery enclosure, and

rate of change of amount of bulging of battery enclosure;

memory storage;

predetermined safety thresholds for said at least one condition stored in said memory storage;

a comparator circuit;

a control circuit;

a diverter switch;

an electrical discharge load;

said comparator circuit comparing said monitored conditions with said stored predetermined safety thresholds and signaling said control circuit whenever said at least one monitored condition exceeds one or more said predetermined thresholds;

said emergency discharge circuit sending an emergency energy discharge signal to said diverter switch in response to signal from said comparator circuit;

said diverter switch causing electrodes of said one or more cells having conditions exceeding said predetermined thresholds to be connected to said energy discharge load.

63. An implantable battery as claimed in claim 62 wherein said discharge load comprises one or more components of said implanted device.

64. An implantable battery as claimed in claim 63 wherein said one or more components of said implanted device is at least one inductive charging coil.

65. An implantable battery as claimed in claim 62 further including an alerting signaling device responsive to said emergency energy discharge circuit to issue an alert when said implantable battery experiences a fault.

66. An implantable battery as claimed in claim 65 wherein said electrical discharge load comprises at least said alerting signaling device.

67. An implantable battery as claimed in claim 66 wherein said alerting signaling device comprises one or more of the following devices:

a radio transmitter,

a lamp,

a light emitting diode,

a sound generator,

a vibrating device.