State of battery health estimation based on swelling characteristics

Patent metadata

Field	Value
Publication number	US-11623526-B2
Application number	US-201615777384-A
Country	US
Kind code	B2
Filing date	Nov 18, 2016
Priority date	Nov 19, 2015
Publication date	Apr 11, 2023
Grant date	Apr 11, 2023

Abstract

There is disclosed an electrical device including a battery, and a battery management system. The battery management system includes a controller in electrical communication with a pressure sensor to monitor the state of health of the battery. The controller applies a method for determining the state of health that uses a non-electrical (mechanical) signal of force measurements combined with incremental capacity analysis to estimate the capacity fading and other health indicators of the battery with better precision than existing methods. The pressure sensor may provide the force measurement signal to the controller, which may determine which incremental capacity curve based on force to use for the particular battery. The controller then executes a program utilizing the data from the pressure sensor and the stored incremental capacity curves based on force to estimate the capacity fading and signal a user with the state of health percentage.

First claim

What is claimed is:

1. An electrical device comprising:
a battery;
a sensor for measuring swelling of the battery; and
a battery management system including a controller in electrical communication with the sensor, the controller being configured to execute a program stored in the controller to determine a state of health percentage of the battery based on a reading from the sensor,
wherein the controller is configured to execute a program stored in the controller to determine a state of health percentage of the battery based on correlating features in a force incremental capacity curve and its derivatives and a pressure reading from the sensor, and
wherein the force incremental capacity curve is calculated by:
(i) measuring a force indicative of swelling within a reference battery over a time period of charge or discharge, wherein the battery is a same type as the reference battery, and
(ii) taking the derivative of a charge or discharge capacity with respect to force (dQ/dF).

2. The device of claim 1 wherein the sensor is selected from
(i) a sensor that measures stress, pressure, or force,
(ii) a sensor that measures strain, or displacement, or
(iii) a sensor that measures any form of physical deformation.

3. The device of claim 2 wherein:
physical deformation is measured using a hydraulic or mechanical or piezoelectric or optical device.

4. The device of claim 2 wherein:
the battery is packaged with the sensor.

5. The device of claim 1 wherein the sensor is a sensor that measures stress, pressure, or force.

6. The device of claim 1 wherein the sensor is a sensor that measures strain, or displacement.

7. The device of claim 1 wherein the sensor is a sensor that measures any form of physical deformation.

8. The device of claim 1 wherein the battery includes:
(i) a plurality of cells, or
(ii) a single cell.

9. The device of claim 8 wherein the cell or cells are selected from:
(i) prismatic cells, or
(ii) cylindrical cells, or
(iii) pouch cells.

10. The device of claim 9 wherein:
each cell comprises:
a positive electrode selected from lithium nickel manganese cobalt oxide, lithium manganese oxide, and lithium iron phosphate; and
a negative electrode selected from graphite, lithium titanate, hard carbon, tin/cobalt alloy, and silicon carbon; and
an electrolyte selected from LiPF 6 , LiBF 4 , and LiCIO 4 .

11. The device of claim 1 wherein:
wherein the battery includes a plurality of cells, and
an inner side of a first plate is in contact with a first end of the plurality of cells, and an inner side of a second plate is in contact with a second end of the plurality of cells.

12. The device of claim 11 wherein:
the sensor is a load cell.

13. The device of claim 12 wherein:
the load cell is adjacent an outer side of the first plate.

14. The device of claim 1 wherein:
the battery is a lithium ion battery pack.

15. The device of claim 1 wherein:
the pressure sensor includes a plurality of pressure sensors.

16. The device of claim 1 wherein:
the controller is configured to execute the program stored in the controller to output a signal associated with the state of health or other diagnostic signals to be used in the battery management system.

17. The device of claim 16 wherein the state of health or other diagnostic signals are selected from one or more of:
(i) capacity fade, or
(ii) resistance growth, or
(iii) expected lifetime signal, or
(iv) anticipated replacement date, or
(v) pre-failure warning.

18. The device of claim 16 wherein the state of health or other diagnostic signal is capacity fade.

19. The device of claim 16 wherein the state of health or other diagnostic signal is resistance growth.

20. The device of claim 16 wherein the state of health or other diagnostic signal is expected lifetime signal.

21. The device of claim 16 wherein the state of health or other diagnostic signal is anticipated replacement date.

22. The device of claim 16 wherein the state of health or other diagnostic signal is pre-failure warning.

23. The device of claim 1 wherein:
the reading from the sensor is taken during charge or discharge of the battery.

24. The device of claim 1 wherein:
the controller determines the state of health percentage of the battery every time the battery is charged or discharged.

25. The device of claim 1 wherein:
the controller determines the state of health percentage of the battery every time the battery discharges below a 70% state of charge.

26. A vehicle comprising:
the electrical device of claim 1 configured to supply electrical power to propel the vehicle, or to supplement propulsion or electric load in a vehicle.

27. A consumer electronics apparatus comprising:
the electrical device of claim 1 .

28. The device of claim 1 wherein the force incremental capacity curve is further derived by:
(iii) correlating the derivative of the charge or discharge capacity with respect to force (dQ/dF) versus voltage.

29. A battery management system for a battery including a sensor for measuring a swelling of the battery, the battery management system comprising:
a controller in electrical communication with the sensor, the controller being configured to execute a program stored in the controller to determine a state of health percentage of the battery based on a reading from the sensor,
wherein the controller is configured to execute a program stored in the controller to determine a state of health percentage of the battery based on correlating features in a force incremental capacity curve and its derivatives and a pressure reading from the sensor, and
wherein the force incremental capacity curve is calculated by:
(i) measuring a force indicative of swelling within a reference battery over a time period of charge or discharge, wherein the battery is a same type as the reference battery, and
(ii) taking the derivative of a charge or discharge capacity with respect to force (dQ/dF).

30. The battery management system of claim 29 wherein the force incremental capacity curve is further derived by:
(iii) correlating the derivative of the charge or discharge capacity with respect to force (dQ/dF) versus voltage.

31. The battery management system of claim 29 wherein the force incremental capacity curve is further derived by:
(iii) quantifying peaks or location of peaks of the force incremental capacity curve.

32. The battery management system of claim 29 wherein taking the derivative of the charge or discharge capacity with respect to force includes first processing data of measured force over the time period of charge or discharge by applying a post processing technique.

33. The battery management system of claim 32 wherein applying a post processing technique includes:
(i) applying a filter, or
(ii) smoothening and averaging, or
(iii) using statistical methods.

34. The battery management system of claim 29 wherein:
the controller is configured to execute the program stored in the controller to output a signal associated with the state of health or other diagnostic signals to be used in the battery management system.

35. The battery management system of claim 34 wherein the state of heal

Assignees

• Univ Michigan Regents

Inventors

• Stefanopoulou Anna G
• Abdul Samad Nassim
• Kim Youngki
• Siegel Jason B

Classifications

• H02J7/82

  Control of state of charge [SOC] · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• B60L3/12 Primary

  Recording operating variables {; Monitoring of operating variables} · CPC title

• B60L2250/10

  by alarm · CPC title

• B60L50/64

  Constructional details of batteries specially adapted for electric vehicles · CPC title