Lithium ion battery overcharge thermal runaway early warning method, early warning device and processing equipment

Abstract

The present disclosure relates to a lithium ion battery overcharge thermal runaway early warning method, an early warning device and a processing device. The lithium ion battery overcharge thermal runaway early warning method comprises: obtaining an electrochemical impedance spectrum of a lithium ion battery, and obtaining a single-point frequency in a low-frequency region of the electrochemical impedance spectrum; performing direct current charging on the lithium ion battery, and injecting an alternating current power with a frequency of the single-point frequency into the lithium ion battery; obtaining a voltage component and a current component of the lithium ion battery under the alternating current power; obtaining an electrochemical impedance of the lithium ion battery according to the voltage component and the current component; and generating overcharge early warning information according to whether a real part amplitude of the electrochemical impedance or an imaginary part amplitude of the electrochemical impedance satisfies a preset condition. Through the technical solution of the present disclosure, the problem of lithium ion overcharge thermal runaway can be found in time, the problem of lithium ion battery overcharge causing thermal runaway and even explosion and fire can be avoided, and the operation safety of the energy storage system can be ensured.

Description

Technical Field

[0001] The present disclosure relates to the technical field of lithium-ion batteries, and in particular to a lithium-ion battery overcharge thermal runaway early warning method, early warning device, and processing equipment. Background Art

[0002] To combat climate change and achieve a low-carbon transition to energy systems, countries around the world are actively promoting the development of renewable energy, and battery energy storage systems are gaining popularity. Lithium-ion batteries, due to their high energy density, long cycle life, low self-discharge rate, and minimal environmental impact, have garnered widespread attention in battery energy storage systems and are a key energy carrier.

[0003] However, the widespread use of lithium-ion batteries also presents safety risks. Thermal runaway can generate significant heat and flammable, toxic gases, leading to fires and explosions, resulting in significant loss of life and property. Overcharging is a key cause of thermal runaway in lithium-ion batteries, and monitoring overcharge during battery operation is crucial. Therefore, a method for rapidly detecting and providing early warning of overcharge thermal runaway in lithium-ion batteries is urgently needed. Summary of the Invention

[0004] To solve the above technical problems, or at least partially solve the above technical problems, the present disclosure provides a lithium-ion battery overcharge thermal runaway early warning method, early warning device, and processing equipment, which can promptly detect the problem of lithium-ion overcharge thermal runaway, avoid the problem of lithium-ion battery overcharge-induced thermal runaway and even explosion and fire, and ensure the operational safety of the energy storage system.

[0005] In a first aspect, the present disclosure provides a lithium-ion battery overcharge thermal runaway early warning method, comprising:

[0006] Obtaining an electrochemical impedance spectrum of the lithium-ion battery, and obtaining a single-point frequency in a low-frequency region of the electrochemical impedance spectrum;

[0007] Performing direct current charging on the lithium-ion battery and injecting alternating current power having a frequency of the single-point frequency into the lithium-ion battery;

[0008] Obtaining a voltage component and a current component of the lithium-ion battery under the AC power supply;

[0009] Obtaining an electrochemical impedance of the lithium-ion battery according to the voltage component and the current component;

[0010] Overcharge warning information is generated according to whether the imaginary part amplitude of the electrochemical impedance or the real part amplitude of the electrochemical impedance meets a preset condition.

[0011] Optionally, generating overcharge warning information according to whether the imaginary part amplitude of the electrochemical impedance or the real part amplitude of the electrochemical impedance meets a preset condition includes:

[0012] According to the imaginary part amplitude of the electrochemical impedance being greater than the first amplitude threshold, first-level overcharge warning information is generated.

[0013] Optionally, the first amplitude threshold is three times the lowest imaginary part amplitude of the lithium-ion battery during this charging process.

[0014] Optionally, generating overcharge warning information according to whether the imaginary part amplitude of the electrochemical impedance or the real part amplitude of the electrochemical impedance meets a preset condition includes:

[0015] According to the real part amplitude of the electrochemical impedance being greater than the second amplitude threshold, second-level overcharge warning information is generated.

[0016] Optionally, the second amplitude threshold is 1.1 times the lowest real part amplitude of the lithium-ion battery during this charging process.

[0017] Optionally, after generating the second-level overcharge warning information, the method further includes:

[0018] Charging of the lithium-ion battery is stopped.

[0019] Optionally, the overcharge warning information includes:

[0020] At least one of a sound prompt message or a display prompt message.

[0021] In a second aspect, the present disclosure further provides a lithium-ion battery overcharge thermal runaway warning device, comprising:

[0022] A single-point frequency acquisition module is used to obtain an electrochemical impedance spectrum of a lithium-ion battery and obtain a single-point frequency in a low-frequency region of the electrochemical impedance spectrum;

[0023] a charging module, configured to perform DC charging on the lithium-ion battery and inject an AC power supply having the single-point frequency into the lithium-ion battery;

[0024] A component acquisition module, configured to acquire a voltage component and a current component of the lithium-ion battery under the AC power supply;

[0025] an electrochemical impedance acquisition module, configured to acquire the electrochemical impedance of the lithium-ion battery based on the voltage component and the current component;

[0026] The overcharge warning information generating module is configured to generate overcharge warning information according to whether the imaginary part of the electrochemical impedance or the real part of the electrochemical impedance meets a preset condition.

[0027] In a third aspect, the present disclosure further provides a computer-readable storage medium storing a program or instruction, which enables a computer to execute the steps of the lithium-ion battery overcharge thermal runaway warning method as described in the first aspect.

[0028] In a fourth aspect, the present disclosure further provides a processing device, comprising a processor and a memory, wherein the processor executes the steps of the lithium-ion battery overcharge thermal runaway warning method as described in the first aspect by calling a program or instruction stored in the memory.

[0029] The technical solution provided by the embodiments of the present disclosure has the following advantages over the prior art:

[0030] The present disclosure provides a lithium-ion battery overcharge thermal runaway early warning method, early warning device, and storage medium. The early warning method comprises: obtaining an electrochemical impedance spectrum of the lithium-ion battery and obtaining a single-point frequency in the low-frequency region of the electrochemical impedance spectrum; performing direct current charging on the lithium-ion battery and injecting an alternating current power supply with a frequency of the single-point frequency into the lithium-ion battery; obtaining the voltage component and current component of the lithium-ion battery under the AC power supply; obtaining the electrochemical impedance of the lithium-ion battery based on the voltage component and the current component; and generating an overcharge early warning message based on whether the imaginary part amplitude of the electrochemical impedance or the real part amplitude of the electrochemical impedance meets a preset condition. Thus, by real-time online monitoring of the single-point frequency electrochemical impedance of the lithium-ion battery, the monitoring speed is improved, and the battery overcharge state is monitored based on the change characteristics of the real and imaginary parts of the electrochemical impedance. Based on whether the imaginary part amplitude of the electrochemical impedance or the real part amplitude of the electrochemical impedance meets a preset condition, an overcharge early warning message is generated. The method can promptly detect the problem of lithium-ion overcharge thermal runaway, avoid the problem of thermal runaway caused by overcharging of the lithium-ion battery and cause explosion and fire, and ensure the operation safety of the energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0032] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0033] Figure 1 A schematic flow chart of a lithium-ion battery overcharge thermal runaway early warning method provided in an embodiment of the present disclosure;

[0034] Figure 2A schematic diagram of an electrochemical impedance spectroscopy of a lithium-ion battery provided in an embodiment of the present disclosure;

[0035] Figure 3 A schematic diagram showing changes in the imaginary part and real part of the electrochemical impedance of a lithium-ion battery during charging provided by an embodiment of the present disclosure;

[0036] Figure 4 A schematic structural diagram of a lithium-ion battery overcharge thermal runaway warning device provided in an embodiment of the present disclosure;

[0037] Figure 5 A schematic diagram of the structure of a processing device provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0038] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features therein can be combined with each other in the absence of conflict.

[0039] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0040] In related technologies, electrochemical impedance spectroscopy (EIS), as an important characteristic parameter of lithium-ion batteries, has received widespread attention in its application in characterizing the state of lithium-ion batteries, especially in overcharge warning. This is crucial for preventing lithium-ion battery overcharge from triggering thermal runaway, ensuring the safe operation of energy storage power stations. However, the acquisition of EIS for lithium-ion batteries takes a long time, making it difficult to timely reflect the state of lithium-ion batteries in practical applications. This can lead to delays in monitoring the overcharge and thermal runaway state of lithium-ion batteries.

[0041] In order to solve the above problems, the present invention provides a lithium-ion battery overcharge thermal runaway early warning method. Figure 1 This is a flow chart of a lithium-ion battery overcharge thermal runaway warning method provided by an embodiment of the present disclosure. The lithium-ion battery overcharge thermal runaway warning method can be applied in application scenarios where it is necessary to determine whether a lithium-ion battery has thermal runaway. The method can be executed by the lithium-ion battery overcharge thermal runaway warning device provided by an embodiment of the present disclosure. The lithium-ion battery overcharge thermal runaway warning device can be implemented in software and / or hardware. Figure 1 As shown in FIG, the lithium-ion battery overcharge thermal runaway warning method includes:

[0042] S101. Obtain an electrochemical impedance spectrum of a lithium-ion battery, and obtain a single-point frequency in a low-frequency region of the electrochemical impedance spectrum.

[0043] For example, the lithium-ion battery is discharged to a cut-off voltage of 2.5 V, corresponding to a state of charge of 0%, and placed in a constant temperature box at 25° C. for more than 1 hour to improve the test accuracy of the lithium-ion battery.

[0044] The electrochemical impedance spectroscopy calibration method was used to obtain the electrochemical impedance spectrum of lithium-ion batteries in the range of 0.1 Hz to 100 Hz. Figure 2 A schematic diagram of the electrochemical impedance spectroscopy of a lithium-ion battery provided in an embodiment of the present disclosure is shown in FIG. Figure 2 As shown, Figure 2 The horizontal axis is the real part of the electrochemical impedance, in micro-ohms, and the vertical axis is the imaginary part of the electrochemical impedance, in micro-ohms. According to the frequency, the electrochemical impedance spectrum is divided into low-frequency region, medium-frequency region and high-frequency region. Figure 2 The dotted lines schematically divide the region. The low-frequency region exhibits Warburg impedance characteristics. This means that due to ion diffusion in the electrolyte, the real and imaginary parts of the electrochemical impedance form a straight line with a slope of 45° in the low-frequency region.

[0045] Because lower EIS frequencies contain more electrochemical reaction information, monitoring of lithium-ion battery overcharge and thermal runaway events is more accurate, further improving the accuracy of overcharge and thermal runaway warnings. Therefore, a single-point frequency, such as 1 Hz, is obtained in the low-frequency region of the EIS. The presently disclosed embodiments do not limit the specific value of the selected single-point frequency.

[0046] It should be noted that the lithium-ion battery used in the embodiment of the present disclosure may be, for example, a 280Ah energy storage lithium-ion battery, and may also be applied to energy storage lithium-ion batteries of other capacities, which is not limited in the embodiment of the present disclosure.

[0047] S102 , performing DC charging on the lithium-ion battery and injecting AC power with a single-point frequency into the lithium-ion battery.

[0048] Specifically, the lithium-ion battery is charged with direct current, and the charging current rate can be, for example, 0.5C, the rated charging rate of the lithium-ion battery, and an alternating current power supply with a frequency of 1 Hz is injected into the lithium-ion battery.

[0049] It should be noted that the charging current rate can be set according to experimental requirements, and the embodiments of the present disclosure are not limited to this.

[0050] S103: Obtain the voltage component and current component of the lithium-ion battery under the AC power supply.

[0051] Specifically, a current detecting device, such as a current sensor, is used to detect the current flowing through the lithium-ion battery, and a voltage detecting device, such as a voltage sensor, is used to detect the voltage flowing through the lithium-ion battery. The current and voltage of the lithium-ion battery are processed using a discrete Fourier transform (DFT) to extract the current and voltage components of the lithium-ion battery under a 1 Hz AC power supply.

[0052] The current component I of a lithium-ion battery under a 1Hz AC power supply k Satisfies the following formula:

[0053]

[0054] Among them, i n is the sampling signal of the lithium-ion battery current in the time domain, N is the total number of sampling points, T is the sampling period, and K is selected so that k / NT=1Hz.

[0055] The voltage component V of the lithium-ion battery under the 1Hz AC power supply k Satisfies the following formula:

[0056]

[0057] Among them, v n is the sampling signal of the lithium-ion battery voltage in the time domain, N is the total number of sampling points, T is the sampling period, and K is selected so that k / NT=1Hz.

[0058] S104: Obtain the electrochemical impedance of the lithium-ion battery according to the voltage component and the current component.

[0059] Specifically, the electrochemical impedance Z of lithium-ion batteries k Satisfies the following formula:

[0060]

[0061] Among them, V k is the voltage component of the lithium-ion battery under a 1Hz AC power supply, I k is the current component of the lithium-ion battery under the AC power supply with a frequency of 1Hz.

[0062] S105 : Generate overcharge warning information according to whether the imaginary part amplitude of the electrochemical impedance or the real part amplitude of the electrochemical impedance meets a preset condition.

[0063] The disclosed embodiments improve monitoring speed by real-time online monitoring of the single-point frequency electrochemical impedance of lithium-ion batteries, and monitor the battery overcharge status based on the changing characteristics of the real and imaginary parts of the electrochemical impedance. Overcharge warning information is generated based on whether the amplitude of the imaginary part of the electrochemical impedance or the amplitude of the real part of the electrochemical impedance meets preset conditions. This can promptly detect the problem of lithium-ion overcharge thermal runaway, avoid the problem of thermal runaway caused by overcharging of lithium-ion batteries and even explosion and fire, and ensure the operational safety of the energy storage system.

[0064] Optionally, overcharge warning information is generated based on whether the imaginary part amplitude of the electrochemical impedance or the real part amplitude of the electrochemical impedance meets a preset condition, including: generating first-level overcharge warning information based on the imaginary part amplitude of the electrochemical impedance being greater than a first amplitude threshold.

[0065] Specifically, when the imaginary part amplitude of the electrochemical impedance is greater than the first amplitude threshold, it indicates that the current balance inside the lithium-ion battery is broken, causing the imaginary part amplitude to rise. The lithium-ion battery is about to enter an overcharge state but has not fully entered the overcharge state, generating a first-level overcharge warning message, thereby prompting relevant personnel to pay attention to the operating status of the lithium-ion battery in a timely manner.

[0066] Optionally, the first amplitude threshold is three times the lowest imaginary part amplitude of the lithium-ion battery during this charging process.

[0067] Figure 3 A schematic diagram of the changes in the imaginary part and real part of the electrochemical impedance of a lithium-ion battery during charging provided by an embodiment of the present disclosure. Figure 3 The horizontal axis is the state of charge (SOC), the vertical axis on the left is the imaginary impedance amplitude, in micro-ohms; the vertical axis on the right is the real impedance amplitude, in micro-ohms. Figure 3 The impedance imaginary part curve corresponding to a single-point frequency of 1Hz shows that before the state of charge reaches 100%, the minimum imaginary part amplitude is 7 microohms. When the imaginary part amplitude of the impedance rises to 22, which is greater than three times the minimum imaginary part amplitude, the lithium-ion battery's state of charge is 100.4%, indicating that the lithium-ion battery is overcharged, and a first-level overcharge warning message is generated.

[0068] Optionally, overcharge warning information is generated based on whether the imaginary part amplitude of the electrochemical impedance or the real part amplitude of the electrochemical impedance meets a preset condition, including: generating second-level overcharge warning information based on the real part amplitude of the electrochemical impedance being greater than a second amplitude threshold.

[0069] Specifically, when the real part amplitude of the electrochemical impedance is greater than the second amplitude threshold, it means that the electrochemical side reaction inside the lithium-ion battery has become very serious and the lithium-ion battery has entered a deep overcharge state. Therefore, the second-level overcharge warning information is generated, prompting relevant personnel to pay attention to the operating status of the lithium-ion battery in a timely manner.

[0070] Optionally, the second amplitude threshold is 1.1 times the lowest real part amplitude of the lithium-ion battery during this charging process.

[0071] Continue to refer to Figure 3 It can be seen that Figure 3 From the real part impedance curve corresponding to the single-point frequency of 1Hz, it can be seen that in the process of continuous increase in the state of charge, the minimum real part amplitude is 327 microohms, and then it turns into an upward trend until it reaches 364 microohms, which is greater than 1.1 times the minimum real part amplitude. At this time, the state of charge of the lithium-ion battery is 117%, indicating that the lithium-ion battery has an overcharge problem, and a second-level overcharge warning information is generated.

[0072] In addition, by Figure 3 It can be seen that the state of charge of the lithium-ion battery corresponding to the second-level overcharge warning information is greater than the state of charge of the lithium-ion battery corresponding to the first-level overcharge warning information. Therefore, the severity of overcharge thermal runaway of the lithium-ion battery corresponding to the second-level overcharge warning information is higher.

[0073] Optionally, after generating the second-level overcharge warning information, the method further includes: stopping charging the lithium-ion battery.

[0074] Specifically, by Figure 3 It can be seen that since the state of charge of the lithium-ion battery has reached 117% when the second-level overcharge warning information is generated, a very serious overcharge problem has occurred. Charging the lithium-ion battery should be stopped to avoid thermal runaway and heat explosion of the lithium-ion battery.

[0075] Optionally, the overcharge warning information includes at least one of sound prompt information and display prompt information.

[0076] For example, a sound prompt can be used to remind relevant personnel that the lithium-ion battery is overcharged. For example, a voice broadcast can be used to remind relevant personnel that the lithium-ion battery is overcharged, or an alarm sound such as a beep can be emitted to remind relevant personnel that the lithium-ion battery is overcharged.

[0077] Alternatively, a display prompt may be provided to indicate that the lithium-ion battery is overcharged. For example, a screen may be displayed, including text indicating overcharge and other prompting information, which is not limited in the present embodiment. For example, a light, such as a flashing light or a continuous light, may be provided to indicate that the lithium-ion battery is overcharged.

[0078] The disclosed embodiments improve monitoring speed by real-time online monitoring of the single-point frequency electrochemical impedance of lithium-ion batteries, and monitor the battery overcharge status based on the changing characteristics of the real and imaginary parts of the electrochemical impedance. Overcharge warning information is generated based on whether the amplitude of the imaginary part of the electrochemical impedance or the amplitude of the real part of the electrochemical impedance meets preset conditions. This can promptly detect the problem of lithium-ion overcharge thermal runaway, avoid the problem of thermal runaway caused by overcharging of lithium-ion batteries and even explosion and fire, and ensure the operational safety of the energy storage system.

[0079] The embodiments of the present disclosure also provide a lithium-ion battery overcharge thermal runaway warning device. Figure 4 A schematic diagram of a lithium-ion battery overcharge thermal runaway warning device provided in an embodiment of the present disclosure is shown in FIG. Figure 4 As shown, the lithium-ion battery overcharge thermal runaway warning device includes: a single-point frequency acquisition module 401, a charging module 402, a component acquisition module 403, an electrochemical impedance acquisition module 404 and an overcharge warning information generation module 405.

[0080] The single-point frequency acquisition module 401 is used to obtain the electrochemical impedance spectrum of the lithium-ion battery and obtain the single-point frequency in the low-frequency region of the electrochemical impedance spectrum; the charging module 402 is used to perform DC charging on the lithium-ion battery and inject an AC power supply with a frequency of the single-point frequency into the lithium-ion battery; the component acquisition module 403 is used to obtain the voltage component and current component of the lithium-ion battery under the AC power supply; the electrochemical impedance acquisition module 404 is used to obtain the electrochemical impedance of the lithium-ion battery based on the voltage component and the current component; the overcharge warning information generation module 405 is used to generate overcharge warning information based on whether the imaginary part of the electrochemical impedance or the real part of the electrochemical impedance meets a preset condition.

[0081] The apparatus provided in the above-mentioned embodiments of the present disclosure and the method provided in the embodiments of the present disclosure are based on the same inventive concept and have the same beneficial effects, and are not described in detail here.

[0082] The present disclosure also provides a processing device. Figure 5 This is a schematic diagram of the structure of a processing device provided in an embodiment of the present disclosure. Figure 5As shown, the processing device includes a processor and a memory. The processor executes the steps of the lithium-ion battery overcharge thermal runaway warning method as described in the above embodiment by calling the program or instructions stored in the memory. Therefore, it has the beneficial effects described in the above embodiment and will not be repeated here.

[0083] like Figure 5 As shown, the processing device can be configured to include at least one processor 501, at least one memory 502, and at least one communication interface 503. The various components in the processing device are coupled together via a bus system 504. The communication interface 503 is used to transmit information with external devices. It is understood that the bus system 504 is used to achieve connection and communication between these components. In addition to the data bus, the bus system 504 also includes a power bus, a control bus, and a status signal bus. However, for the sake of clarity, the bus system 504 is not described in detail. Figure 5 Various buses are labeled as bus system 504 .

[0084] It is understood that the memory 502 in this embodiment can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memory. In some embodiments, the memory 502 stores the following elements: executable units or data structures, or their subsets, or their extended sets operating systems and applications. In the embodiment of the present disclosure, the processor 501 executes the steps of each embodiment of the lithium-ion battery overcharge thermal runaway early warning method provided in the embodiment of the present disclosure by calling the program or instructions stored in the memory 502.

[0085] The lithium-ion battery overcharge thermal runaway early warning method provided in the embodiment of the present disclosure can be applied to the processor 501 or implemented by the processor 501. The processor 501 can be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method can be completed by the hardware integrated logic circuit in the processor 501 or by instructions in the form of software. The above-mentioned processor 501 can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc.

[0086] The steps of the lithium-ion battery overcharge thermal runaway warning method provided in the embodiments of the present disclosure can be directly implemented and executed by a hardware decoding processor, or by a combination of hardware and software units in the decoding processor. The software unit can be located in a storage medium well-known in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage medium is located in memory 502, and processor 501 reads the information in memory 502 and combines it with hardware to complete the steps of the method.

[0087] The processing device may also include one or more physical components, based on instructions generated by the processor 501 when executing the lithium-ion battery overcharge thermal runaway warning method provided in the embodiment of the present application. Different physical components can be set within the processing device or outside the processing device, such as a cloud server. Each physical component cooperates with the processor 501 and the memory 502 to implement the functions of the processing device in this embodiment.

[0088] The embodiments of the present disclosure further provide a computer-readable storage medium, which stores a program or instruction. The program or instruction enables a computer to execute the steps of any one of the methods provided in the above embodiments.

[0089] In some embodiments, when executed by a computer processor, the computer executable instructions can also be used to execute the technical solutions of any of the above methods provided in the embodiments of the present disclosure to achieve corresponding beneficial effects.

[0090] Through the above description of the implementation methods, those skilled in the art can clearly understand that the present disclosure can be implemented with the help of software and necessary general-purpose hardware. Of course, it can also be implemented through hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present disclosure, or the part that contributes to the existing technology, can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory (FLASH), hard disk or optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute the methods of various embodiments of the present disclosure.

[0091] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device that includes the element.

[0092] The above are merely specific embodiments of the present disclosure, intended to enable those skilled in the art to understand and implement the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure is not limited to these embodiments, but is to be construed in the broadest manner consistent with the principles and novel features disclosed herein.

Claims

1. A lithium-ion battery overcharge thermal runaway early warning method, characterized in that: include: Obtaining an electrochemical impedance spectrum of the lithium-ion battery, and obtaining a single-point frequency in a low-frequency region of the electrochemical impedance spectrum; Performing direct current charging on the lithium-ion battery and injecting alternating current power having a frequency of the single-point frequency into the lithium-ion battery; Obtaining a voltage component and a current component of the lithium-ion battery under the AC power supply; Obtaining an electrochemical impedance of the lithium-ion battery according to the voltage component and the current component; generating overcharge warning information according to whether the imaginary part amplitude of the electrochemical impedance or the real part amplitude of the electrochemical impedance meets a preset condition; Among them, according to the imaginary part amplitude of the electrochemical impedance being greater than the first amplitude threshold, the first level overcharge warning information is generated; according to the real part amplitude of the electrochemical impedance being greater than the second amplitude threshold, the second level overcharge warning information is generated.

2. The lithium-ion battery overcharge thermal runaway early warning method according to claim 1, characterized in that: The first amplitude threshold is three times the lowest imaginary part amplitude of the lithium-ion battery during this charging process.

3. The lithium-ion battery overcharge thermal runaway early warning method according to claim 1, characterized in that: The second amplitude threshold is 1.1 times the lowest real part amplitude of the lithium-ion battery during this charging process.

4. The lithium-ion battery overcharge thermal runaway early warning method according to claim 1, characterized in that: After generating the second-level overcharge warning information, the method further includes: Charging of the lithium-ion battery is stopped.

5. The lithium-ion battery overcharge thermal runaway early warning method according to claim 1, characterized in that: The overcharge warning information includes: At least one of a sound prompt message or a display prompt message.

6. A lithium-ion battery overcharge thermal runaway warning device, characterized in that: include: A single-point frequency acquisition module is used to obtain an electrochemical impedance spectrum of a lithium-ion battery and obtain a single-point frequency in a low-frequency region of the electrochemical impedance spectrum; a charging module, configured to perform DC charging on the lithium-ion battery and inject an AC power supply having the single-point frequency into the lithium-ion battery; A component acquisition module, configured to acquire a voltage component and a current component of the lithium-ion battery under the AC power supply; an electrochemical impedance acquisition module, configured to acquire the electrochemical impedance of the lithium-ion battery based on the voltage component and the current component; an overcharge warning information generating module, configured to generate overcharge warning information according to whether the imaginary part of the electrochemical impedance or the real part of the electrochemical impedance meets a preset condition; The overcharge warning information generating module is configured to generate a first level overcharge warning information according to the imaginary part amplitude of the electrochemical impedance being greater than a first amplitude threshold; The overcharge warning information generation module is used to generate second-level overcharge warning information according to the real part amplitude of the electrochemical impedance being greater than the second amplitude threshold.

7. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a program or instruction, which enables the computer to execute the steps of the lithium-ion battery overcharge thermal runaway early warning method according to any one of claims 1 to 5.

8. A processing device, characterized in that The method comprises a processor and a memory, wherein the processor executes the steps of the lithium-ion battery overcharge thermal runaway early warning method according to any one of claims 1 to 5 by calling a program or instruction stored in the memory.

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