Internal temperature measuring system and method based on high-temperature universal lithium ion battery

Abstract

The invention discloses an internal temperature measurement system and method based on a high-temperature universal lithium ion battery. Comprising an electric signal measurement module, a data collection module, a temperature-sensitive electrical parameter measurement module, a similarity criterion number calculation module and a temperature-sensitive electrical parameter and temperature calibration module. The electric signal measurement module is in signal connection with the data collection module; the data collection module is in signal connection with the similarity criterion number calculation module and the temperature-sensitive electrical parameter measurement module. The temperature-sensitive electrical parameter and temperature calibration module is respectively in signal connection with the similarity criterion number calculation module and the temperature-sensitive electrical parameter measurement module; according to the method, a total battery Warburg coefficient reflecting the solid-phase diffusion characteristic of an electrode is defined as a temperature-sensitive electrical parameter, the temperature-sensitive electrical parameter and a similarity criterion number are calculated by using terminal voltage and an electrochemical impedance spectrum, and the internal temperature of the battery is measured through a temperature-sensitive electrical parameter-temperature mapping relation established according to a similarity theory. The problems of low temperature measurement upper limit and poor universality in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the field of battery measurement, and in particular to a system and method for measuring the internal temperature of a high-temperature general-purpose lithium-ion battery. Background Art

[0002] The internal temperature of the battery is the main signal for identifying the development from normal working state to thermal runaway. Therefore, research on internal temperature measurement technology of lithium-ion batteries can serve as early warning of abnormal temperature batteries and will significantly improve safety.

[0003] The lithium-ion internal temperature measurement system based on dynamic electrochemical impedance spectroscopy (DESI) offers significant advantages, including non-invasiveness, fast response, and compatibility with battery management systems. This system utilizes a single, specific frequency impedance associated with the negative electrode SEI film as a temperature-sensitive electrical parameter and uses data-driven mapping between that parameter and the battery's internal temperature for temperature measurement. However, due to limitations in the measurement mechanism, it suffers from the following main drawbacks:

[0004] On the one hand, the negative electrode SEI film has poor thermal stability and usually begins to decompose when the temperature exceeds 60°C, resulting in a low upper temperature limit for the system;

[0005] On the other hand, the temperature-sensitive electrical parameter-temperature mapping relationship established by the data-driven method is only applicable to specific batteries, resulting in poor system versatility. Summary of the Invention

[0006] The present invention aims to overcome the shortcomings and deficiencies of the aforementioned prior art by providing a system and method for measuring the internal temperature of a high-temperature, general-purpose lithium-ion battery. This system defines the full-cell Warburg coefficient, which reflects the solid-phase diffusion characteristics of the electrode, as a temperature-sensitive electrical parameter. The system calculates the temperature-sensitive electrical parameter and similarity criterion using terminal voltage and electrochemical impedance spectroscopy. The system then measures the internal temperature of the battery using a temperature-sensitive electrical parameter-temperature mapping relationship established based on similarity theory. This approach addresses the shortcomings of the prior art, which suffer from a low temperature measurement limit and poor versatility.

[0007] The present invention is achieved through the following technical solutions:

[0008] A high-temperature universal lithium-ion battery internal temperature measurement system includes an electrical signal measurement module, a data collection module, a temperature-sensitive electrical parameter measurement module, a similarity criterion number calculation module, and a temperature-sensitive electrical parameter and temperature calibration module;

[0009] The electrical signal measurement module is signal-connected to the data collection module;

[0010] The data collection module is signal-connected to the similarity criterion number calculation module and the temperature-sensitive electrical parameter measurement module respectively;

[0011] The temperature-sensitive electrical parameter and temperature calibration module is respectively connected to the similarity criterion number calculation module and the temperature-sensitive electrical parameter measurement module by signal.

[0012] The electrical signal measurement module measures the electrochemical impedance data and terminal voltage data of the battery and transmits the data to the data collection module.

[0013] The data collection module is used to store and collect electrochemical impedance data and terminal voltage data from the data collection module.

[0014] The temperature-sensitive electrical parameter measurement module is used to use the Warburg coefficient of the full battery as a temperature-sensitive electrical parameter.

[0015] The similarity criterion number calculation module is used to calculate the similarity criterion number by performing online identification on the battery P2D model parameters and combining the similarity criterion number expression.

[0016] The temperature-sensitive electrical parameter and temperature calibration module is used to quantify the internal temperature of the battery according to the values ​​of the temperature-sensitive electrical parameter and the similarity criterion number through a temperature-sensitive electrical parameter-temperature mapping correlation formed based on similarity theory.

[0017] A method for obtaining the internal temperature of a battery, the specific steps are as follows:

[0018] S1. Battery data measurement: The electrical signal measurement module collects the electrochemical impedance data and terminal voltage data of the battery. Specifically, the voltage sensor measures the terminal voltage data of the battery under test during the charge and discharge process. During the charge and discharge process, the electrochemical impedance tester applies a sinusoidal AC current signal to the battery and processes the corresponding AC current signal to obtain AC electrochemical impedance data.

[0019] S2. Battery data collection: The electrical signal measurement module transmits the electrochemical impedance data and terminal voltage data of the battery to the data collection module; the data collection module collects and stores the electrochemical impedance data and terminal voltage data;

[0020] S3. Battery temperature-sensitive electrical parameter measurement: The temperature-sensitive electrical parameter measurement module extracts the impedance of the semi-infinite diffusion region of the full-battery Nyquist plot and performs a linear regression on the impedance of the semi-infinite diffusion region and the -1 / 2 power of its frequency. The corresponding straight line slope is the Warburg coefficient of the full-battery.

[0021] S4. Similarity criterion number calculation: The similarity criterion number calculation module first inputs the terminal voltage data and electrochemical impedance spectrum data from the data collection module into the battery P2D model. Combined with the optimization algorithm, the minimum mean square error between the simulated value and the measured value of the terminal voltage and dynamic impedance spectrum is used as the optimization target. The P2D model parameters are identified and the similarity criterion number is calculated.

[0022] S5. Thermosensitive electrical parameters and temperature calibration: The thermosensitive electrical parameters and temperature calibration module calculates the internal temperature of the battery based on the values ​​of the thermosensitive electrical parameters and the similarity criterion number, using the thermosensitive electrical parameter-temperature mapping correlation formed based on the similarity theory.

[0023] Compared with the prior art, the present invention has the following advantages and effects:

[0024] The present invention utilizes the full-cell Warburg coefficient, which reflects the solid-phase diffusion characteristics of the electrode, as a temperature-sensitive electrical parameter. On this basis, a universal internal temperature measurement method for lithium-ion batteries is formed by establishing a temperature-sensitive electrical parameter-temperature physical mapping relationship based on similarity theory. This method not only significantly increases the system's temperature measurement upper limit to approximately 180°C, but also significantly improves the versatility of the temperature measurement system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a flow chart of the internal temperature measurement of a high-temperature general-purpose lithium-ion battery of the present invention. DETAILED DESCRIPTION

[0026] The present invention is described in further detail below with reference to specific embodiments.

[0027] like Figure 1 As shown, the present invention discloses a high-temperature universal lithium-ion battery internal temperature measurement system, including an electrical signal measurement module, a data collection module, a temperature-sensitive electrical parameter measurement module, a similarity criterion number calculation module, and a temperature-sensitive electrical parameter and temperature calibration module;

[0028] The electrical signal measurement module is signal-connected to the data collection module;

[0029] The data collection module is signal-connected to the similarity criterion number calculation module and the temperature-sensitive electrical parameter measurement module respectively;

[0030] The temperature-sensitive electrical parameter and temperature calibration module is respectively connected to the similarity criterion number calculation module and the temperature-sensitive electrical parameter measurement module by signal.

[0031] The electrical signal measurement module measures the electrochemical impedance data and terminal voltage data of the battery and transmits the data to the data collection module.

[0032] The data collection module is used to store and collect electrochemical impedance data and terminal voltage data from the data collection module.

[0033] The temperature-sensitive electrical parameter measurement module is used to use the Warburg coefficient of the full battery as a temperature-sensitive electrical parameter.

[0034] The similarity criterion number calculation module is used to calculate the similarity criterion number by performing online identification on the battery P2D model parameters and combining the similarity criterion number expression.

[0035] The temperature-sensitive electrical parameter and temperature calibration module is used to quantify the internal temperature of the battery according to the values ​​of the temperature-sensitive electrical parameter and the similarity criterion number through a temperature-sensitive electrical parameter-temperature mapping correlation formed based on similarity theory.

[0036] A method for obtaining the internal temperature of a battery, the specific steps are as follows:

[0037] S1. Battery data measurement: The electrical signal measurement module collects the electrochemical impedance data and terminal voltage data of the battery. Specifically, the voltage sensor measures the terminal voltage data of the battery under test during the charge and discharge process. During the charge and discharge process, the electrochemical impedance tester applies a sinusoidal AC current signal to the battery and processes the corresponding AC current signal to obtain AC electrochemical impedance data.

[0038] S2. Battery data collection: The electrical signal measurement module transmits the electrochemical impedance data and terminal voltage data of the battery to the data collection module; the data collection module collects and stores the electrochemical impedance data and terminal voltage data;

[0039] S3. Battery temperature-sensitive electrical parameter measurement: The temperature-sensitive electrical parameter measurement module extracts the impedance of the semi-infinite diffusion region of the full-battery Nyquist plot and performs a linear regression on the impedance of the semi-infinite diffusion region and the -1 / 2 power of its frequency. The corresponding straight line slope is the Warburg coefficient of the full-battery.

[0040] S4. Similarity criterion number calculation: The similarity criterion number calculation module first inputs the terminal voltage data and electrochemical impedance spectrum data from the data collection module into the battery P2D model. Combined with the optimization algorithm, the minimum mean square error between the simulated value and the measured value of the terminal voltage and dynamic impedance spectrum is used as the optimization target. The P2D model parameters are identified and the similarity criterion number is calculated.

[0041] S5. Thermosensitive electrical parameters and temperature calibration: The thermosensitive electrical parameters and temperature calibration module calculates the internal temperature of the battery based on the values ​​of the thermosensitive electrical parameters and the similarity criterion number, using the thermosensitive electrical parameter-temperature mapping correlation formed based on the similarity theory.

[0042] As described above, the present invention defines the full-cell Warburg coefficient, which reflects the solid-phase diffusion characteristics of the electrode, as a temperature-sensitive electrical parameter. The advantages of the electrode's good thermal stability and high decomposition temperature are utilized to significantly increase the upper limit of temperature measurement. On this basis, a universal internal temperature measurement method for lithium-ion batteries is formed by establishing a temperature-sensitive electrical parameter-temperature physical mapping relationship based on similarity theory.

[0043] The implementation methods of the present invention are not limited to the above-mentioned embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A high-temperature universal lithium-ion battery internal temperature measurement system, characterized in that: It includes an electrical signal measurement module, a data collection module, a temperature-sensitive electrical parameter measurement module, a similarity criterion number calculation module, and a temperature-sensitive electrical parameter and temperature calibration module; The electrical signal measurement module is signal-connected to the data collection module; The data collection module is signal-connected to the similarity criterion number calculation module and the temperature-sensitive electrical parameter measurement module respectively; The temperature-sensitive electrical parameter and temperature calibration module is respectively connected to the similarity criterion number calculation module and the temperature-sensitive electrical parameter measurement module by signal.

2. The high-temperature universal lithium-ion battery internal temperature measurement system according to claim 1, characterized in that: The electrical signal measurement module measures the electrochemical impedance data and terminal voltage data of the battery and transmits the data to the data collection module.

3. The high-temperature universal lithium-ion battery internal temperature measurement system according to claim 1, characterized in that: The data collection module is used to store and collect electrochemical impedance data and terminal voltage data from the electrical signal measurement module of the data collection module.

4. The high-temperature universal lithium-ion battery internal temperature measurement system according to claim 1, characterized in that: The temperature-sensitive electrical parameter measurement module is used to use the Warburg coefficient of the full battery as a temperature-sensitive electrical parameter.

5. The high-temperature universal lithium-ion battery internal temperature measurement system according to claim 1, characterized in that: The similarity criterion number calculation module is used to calculate the similarity criterion number by performing online identification on the battery P2D model parameters and combining the similarity criterion number expression.

6. The high-temperature universal lithium-ion battery internal temperature measurement system according to claim 4 or 5, characterized in that: The temperature-sensitive electrical parameter and temperature calibration module is used to quantify the internal temperature of the battery according to the values ​​of the temperature-sensitive electrical parameter and the similarity criterion number through a temperature-sensitive electrical parameter-temperature mapping correlation formed based on similarity theory.

7. A method for obtaining the internal temperature of a battery, characterized in that: The high-temperature universal lithium-ion battery internal temperature measurement system according to any one of claims 1 to 6 is used for implementation, and the specific steps are as follows: S1. Battery data measurement: The electrical signal measurement module collects the electrochemical impedance data and terminal voltage data of the battery. Specifically, the voltage sensor measures the terminal voltage data of the battery under test during the charge and discharge process. During the charge and discharge process, the electrochemical impedance tester applies a sinusoidal AC current signal to the battery and processes the corresponding AC current signal to obtain AC electrochemical impedance data. S2. Battery data collection: The electrical signal measurement module transmits the electrochemical impedance data and terminal voltage data of the battery to the data collection module; the data collection module collects and stores the electrochemical impedance data and terminal voltage data; S3. Battery temperature-sensitive electrical parameter measurement: The temperature-sensitive electrical parameter measurement module extracts the impedance of the semi-infinite diffusion region of the full-battery Nyquist plot and performs a linear regression on the impedance of the semi-infinite diffusion region and the -1 / 2 power of its frequency. The corresponding straight line slope is the Warburg coefficient of the full-battery. S4. Similarity criterion number calculation: The similarity criterion number calculation module first inputs the terminal voltage data and electrochemical impedance spectrum data from the data collection module into the battery P2D model. Combined with the optimization algorithm, the minimum mean square error between the simulated value and the measured value of the terminal voltage and dynamic impedance spectrum is used as the optimization target. The P2D model parameters are identified and the similarity criterion number is calculated. S5. Thermosensitive electrical parameters and temperature calibration: The thermosensitive electrical parameters and temperature calibration module calculates the internal temperature of the battery based on the values ​​of the thermosensitive electrical parameters and the similarity criterion number, using the thermosensitive electrical parameter-temperature mapping correlation formed based on the similarity theory.

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