CN-121995221-A - Battery thermal model based on electrochemical impedance spectroscopy

Abstract

The present disclosure relates to battery thermal models based on electrochemical impedance spectroscopy. The surface temperature of the cells in the battery pack may be inferred or estimated using the internal or core temperature of the cells and the thermal model. The internal temperature may be generated using Electrochemical Impedance Spectroscopy (EIS). Delta values from EIS estimates to battery surface temperatures may be generated based on a thermal model of the battery. Thermal models of the cells can be created using probe points (e.g., thermocouples) on the surface of the test cells.

Inventors

• C. Lefgler

Assignees

• 亚德诺半导体国际无限责任公司

Dates

Publication Date

20260508

Application Date

20251107

Priority Date

20241108

Claims (20)

1. 1. A method of estimating a battery surface temperature, the method comprising: receiving a first temperature estimate of a battery cell from the battery cell based on at least one impedance measurement, the first temperature estimate representing a bulk body temperature of the battery cell; generating a delta value for the battery cell based on the thermal model, and The first temperature estimate is modified based on the delta value to generate a second temperature estimate for the battery cell.
2. 2. The method of claim 1, wherein the second temperature estimate is a surface temperature estimate of the battery cell.
3. 3. The method of claim 1, further comprising: a current condition associated with the battery is received, wherein the delta value is generated based further on the current condition using the thermal model.
4. 4. The method of claim 1, further comprising: At least one temperature measurement is received from a thermocouple coupled to the battery, wherein generating the delta value is further based on the at least one measurement.
5. 5. The method of claim 1, wherein the delta values comprise a minimum surface temperature delta value and a maximum surface temperature delta value.
6. 6. The method of claim 1, wherein the thermal model comprises a look-up table.
7. 7. The method of claim 1, wherein the thermal model is created by using probe points on a test battery surface.
8. 8. The method of claim 1, wherein the first temperature estimate is based on an electrochemical impedance spectrum of the at least one impedance measurement.
9. 9. A system, comprising: One or more processors of a machine, and A memory storing instructions that, when executed by the one or more processors, cause the machine to: Receiving a first temperature estimate of a battery cell from the battery cell based on at least one impedance measurement, the first temperature estimate representing a bulk body temperature of the battery cell; generating a delta value for the battery cell based on the thermal model, and The first temperature estimate is modified based on the delta value to generate a second temperature estimate for the battery cell.
10. 10. The system of claim 9, wherein the second temperature estimate is a surface temperature estimate of the battery cell.
11. 11. The system of claim 9, the operations further comprising: a current condition associated with the battery is received, wherein the delta value is generated based further on the current condition using the thermal model.
12. 12. The system of claim 9, the operations further comprising: At least one temperature measurement is received from a thermocouple coupled to the battery, wherein generating the delta value is further based on the at least one measurement.
13. 13. The system of claim 9, wherein the delta values comprise a minimum surface temperature delta value and a maximum surface temperature delta value.
14. 14. The system of claim 9, wherein the thermal model comprises a lookup table.
15. 15. The system of claim 9, wherein the thermal model is created by using probe points on a test battery surface.
16. 16. The system of claim 9, wherein the first temperature estimate is based on an electrochemical impedance spectrum of the at least one impedance measurement.
17. 17. A machine-readable storage medium containing instructions which, when executed by a machine, cause the machine to perform operations comprising: Receiving a first temperature estimate of a battery cell from the battery cell based on at least one impedance measurement, the first temperature estimate representing a bulk body temperature of the battery cell; generating a delta value for the battery cell based on the thermal model, and The first temperature estimate is modified based on the delta value to generate a second temperature estimate for the battery cell.
18. 18. The machine-readable storage medium of claim 17, wherein the second temperature estimate is a surface temperature estimate of the battery cell.
19. 19. The machine-readable storage medium of claim 17, further comprising: a current condition associated with the battery is received, wherein the delta value is generated based further on the current condition using the thermal model.
20. 20. The machine-readable storage medium of claim 17, further comprising: At least one temperature measurement is received from a thermocouple coupled to the battery, wherein generating the delta value is further based on the at least one measurement.

Description

Battery thermal model based on electrochemical impedance spectroscopy Technical Field The present disclosure relates generally to battery temperature monitoring, and more particularly to a technique for estimating battery surface temperature using a battery thermal model. Background Rechargeable batteries, such as lithium ion batteries, are commonly used in portable electronics and Electric Vehicles (EVs), as well as in various other applications, such as military and aerospace applications. It is important to monitor the temperature of such batteries during various operations, such as fast charge and fast discharge operations, to maximize the performance of the batteries. For example, temperature monitoring can maintain battery temperature within prescribed boundaries or ranges (maximum and minimum) during rapid charging, limit current to avoid overheating during rapid discharge, and prevent damage to the battery due to abnormal use to ensure safety. Disclosure of Invention The present disclosure describes a method of estimating a battery surface temperature. The method includes receiving a first temperature estimate of a battery cell from the battery cell based on at least one impedance measurement, the first temperature estimate representing a bulk body temperature of the battery cell, generating a delta value of the battery cell based on a thermal model, and modifying the first temperature estimate based on the delta value to generate a second temperature estimate of the battery cell. The present disclosure also describes a system comprising one or more processors of a machine, and a memory storing instructions that, when executed by the one or more processors, cause the machine to receive a first temperature estimate of a battery cell from the battery cell based on at least one impedance measurement, the first temperature estimate representing a bulk body temperature of the battery cell, generate a delta value of the battery cell based on a thermal model, and modify the first temperature estimate based on the delta value to generate a second temperature estimate of the battery cell. The present disclosure also describes a machine-readable storage medium containing instructions that, when executed by a machine, cause the machine to receive a first temperature estimate of a battery cell from the battery cell, the first temperature estimate representing a bulk body temperature of the battery cell, based on at least one impedance measurement, generate a delta value for the battery cell based on a thermal model, and modify the first temperature estimate based on the delta value to generate a second temperature estimate for the battery cell. Drawings The various figures of the drawings illustrate only example embodiments of the disclosure and are not to be considered limiting of its scope. Fig. 1 shows a block diagram of an example portion of a battery monitoring system. FIG. 2 is a flow chart of a method for generating a surface temperature estimate. FIG. 3 is a flow chart of a method for generating a surface temperature estimate. Fig. 4 shows an example portion of a test battery setup. FIG. 5 is a flow chart of a method for generating a thermal model. Fig. 6 illustrates a block diagram that includes an example of a machine on which any one or more of the techniques (e.g., methods) discussed herein may be performed. Detailed Description Improved techniques for cell surface temperature estimation are described. The surface temperature of the cells in the battery pack may be inferred or estimated using the internal or core temperature of the cells and the thermal model. The internal temperature may be generated using Electrochemical Impedance Spectroscopy (EIS). Delta values from EIS estimates to battery surface temperatures may be generated based on a thermal model of the battery. Thermal models of the cells can be created using probe points (e.g., thermocouples) on the surface of the test cells. Fig. 1 shows a block diagram of an example portion of a battery monitoring system 100. The battery monitoring system 100 includes a battery pack having a plurality of battery cells 102.1-102. N. The plurality of battery cells 102.1-102.N may be provided in different shapes, such as a hexagonal cube, a cylindrical shape, etc. In the example of fig. 1, the battery pack includes four rows of twelve battery cells, resulting in a total of forty-eight battery cells. The battery monitoring system 100 includes an Electrochemical Impedance Spectroscopy (EIS) Printed Circuit Board (PCB) 104.1-104.M coupled to a plurality of battery cells 102.1-102. N. The EIS PCBs 104.1-104.M may measure impedance changes in the individual cells 102.1-102. N. As explained in further detail below, the impedance variation is used to create an internal temperature, also referred to as core temperature (CoreTemp), of each cell 102.1-102. N. As used herein, the internal or core temperature refers to the bulk body temperature of the battery cell. T