METHODS AND APPARATUS FOR SENSING THE INTERNAL TEMPERATURE OF AN ELECTROCHEMICAL DEVICE

• US 20140372055A1
• Filed: 06/12/2014
• Published: 12/18/2014
• Est. Priority Date: 06/14/2013
• Status: Active Grant

• Current Assignee: HRL Laboratories LLC (The Boeing Co.)
• Original Assignee: HRL Laboratories LLC (The Boeing Co.)
• Inventors: WANG, Shuoqin, WANG, John, SOUKIAZIAN, Souren, GRAETZ, Jason A.
• Granted Patent: US 9,880,061 B2
• Time in Patent Office: Days
• US Class Current: 702/63
• CPC Class Codes: G01K 13/00 Thermometers specially adapted for specific purposes
• CPC Class Codes: G01K 7/427 Temperature calculation based on spatial modeling, e.g. spatial inter- or extrapolation
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: G01R 31/389 Measuring internal impedance, internal conductance or related variables
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The internal temperature of an electrochemical device may be probed without a thermocouple, infrared detector, or other auxiliary device to measure temperature. Some methods include exciting an electrochemical device with a driving profile; acquiring voltage and current data from the electrochemical device, in response to the driving profile; calculating an impulse response from the current and voltage data; calculating an impedance spectrum of the electrochemical device from the impulse response; calculating a state-of-charge of the electrochemical device; and then estimating internal temperature of the electrochemical device based on a temperature-impedance-state-of-charge relationship. The electrochemical device may be a battery, fuel cell, electrolytic cell, or capacitor, for example. The procedure is useful for on-line applications which benefit from real-time temperature sensing capabilities during operations. These methods may be readily implemented as part of a device management and safety system.

Claims

1. A method of estimating the internal temperature of an electrochemical device, said method comprising:

(a) exciting said electrochemical device with a driving profile;

(b) acquiring voltage and current data from said electrochemical device, in response to said driving profile;

(c) calculating an impulse response from said current and voltage data and time derivatives thereof, using a recursive or matrix-based technique;

(d) calculating an impedance spectrum of said electrochemical device from said impulse response using an impulse response model;

(e) calculating a state-of-charge of said electrochemical device; and

(f) estimating an internal temperature of said electrochemical device based on a temperature-impedance-state-of-charge relationship characterizing said electrochemical device.

2. The method of claim 1, wherein said driving profile includes a plurality of double-pulse sequences, wherein each of said double-pulse sequences comprises a constant-current discharge pulse having a pulse width and a pulse amplitude, a constant-current charge pulse having said pulse width and said pulse amplitude, and a zero-current period.

3. The method of claim 1, wherein step (c) utilizes a Kalman filtering technique.

4. The method of claim 1, wherein said recursive or matrix-based method utilizes a moving window to update time-varying electrical responses.

5. The method of claim 1, wherein said impulse response model is a finite impulse response digital filter or an infinite impulse response digital filter.

6. The method of claim 1, wherein said impedance spectrum in step (d) is calculated in a frequency range of about 0.01 Hz to about 1000 Hz.

7. The method of claim 6, wherein said frequency range is about 0.1 Hz to about 1 Hz.

8. The method of claim 1, wherein step (e) comprises calculating the Fourier transform of said impulse response to obtain said state-of-charge.

9. The method of claim 1, wherein step (e) comprises calculating said state-of-charge based on an initial open-circuit voltage and Coulomb counting.

10. The method of claim 1, wherein said temperature-impedance-state-of-charge relationship is in the form of an empirical look-up table or graph that is applicable to said electrochemical device and/or a theoretical equation correlating impedance with temperature and state-of-charge.

11. The method of claim 1, wherein said method is implemented in a temperature safety device within a temperature range selected from −

30°

C. to 120°

C.

12. The method of claim 1, said method further comprising repeating steps (a)-(f) continually or periodically during operation of said electrochemical device.

13. A temperature-sensing apparatus for estimating the internal temperature of an electrochemical device, said apparatus comprising a computer that is electrically linkable to said electrochemical device;

said computer programmed using non-transitory memory with executable code for executing the steps of;

(a) exciting said electrochemical device with a driving profile;

(b) acquiring voltage and current data from said electrochemical device, in response to said driving profile;

(c) calculating an impulse response from said current and voltage data and time derivatives thereof, using a recursive or matrix-based technique;

(d) calculating an impedance spectrum of said electrochemical device from said impulse response using an impulse response model;

(e) calculating a state-of-charge of said electrochemical device; and

(f) estimating an internal temperature of said electrochemical device based on a temperature-impedance-state-of-charge relationship characterizing said electrochemical device.

14. A temperature-monitored electrochemical system comprising said temperature-sensing apparatus of claim 13, wherein said temperature-sensing apparatus is electrically linked to said electrochemical device.

15. The temperature-monitored electrochemical system of claim 14, wherein said electrochemical device is selected from the group consisting of a battery, a fuel cell, an electrolytic cell, a capacitor, a supercapacitor, a pseudocapacitor, an electroplating system, and a galvanic corrosion system.

16. The temperature-monitored electrochemical system of claim 14, wherein said driving profile includes a plurality of double-pulse sequences, wherein each of said double-pulse sequences comprises a constant-current discharge pulse having a pulse width and a pulse amplitude, a constant-current charge pulse having said pulse width and said pulse amplitude, and a zero-current period.

17. The temperature-monitored electrochemical system of claim 14, wherein step (c) utilizes a Kalman filtering technique.

18. The temperature-monitored electrochemical system of claim 14, wherein said recursive or matrix-based technique utilizes a moving window to update time-varying electrical responses.

19. The temperature-monitored electrochemical system of claim 14, wherein said impulse response model is a finite impulse response digital filter or an infinite impulse response digital filter.

20. The temperature-monitored electrochemical system of claim 14, wherein said impedance spectrum in step (d) is estimated in a frequency range of about 0.01 Hz to about 1000 Hz.

21. The temperature-monitored electrochemical system of claim 20, wherein said frequency range is about 0.1 Hz to about 1 Hz.

22. The temperature-monitored electrochemical system of claim 14, wherein step (e) comprises calculating the Fourier transform of said impulse response to obtain said state-of-charge.

23. The temperature-monitored electrochemical system of claim 14, wherein step (e) comprises calculating said state-of-charge based on an initial open-circuit voltage and Coulomb counting.

24. The temperature-monitored electrochemical system of claim 14, wherein said temperature-impedance-state-of-charge relationship is in the form of an empirical look-up table or graph that is applicable to said electrochemical device and/or a theoretical equation correlating impedance with temperature and state-of-charge.

25. The temperature-monitored electrochemical system of claim 14, wherein said temperature-sensing apparatus is a temperature safety device within a temperature range selected from −

30°

C. to 120°

C.