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

Abstract

The invention relates to a lithium ion battery overcharge thermal runaway early warning method, early warning device and processing equipment, and the lithium ion battery overcharge thermal runaway early warning method comprises the steps: 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 supply of which the frequency is a single-point frequency into the lithium ion battery; acquiring a voltage component and a current component of the lithium ion battery under the alternating current power supply; acquiring the electrochemical impedance of the lithium ion battery according to the voltage component and the current component; and generating overcharge early warning information according to the condition that the imaginary part amplitude of the electrochemical impedance or the real part amplitude of the electrochemical impedance meets a preset condition. Through the technical scheme disclosed by the invention, the problem of lithium ion overcharge thermal runaway can be found in time, the problem of explosion fire caused by thermal runaway caused by lithium ion battery overcharge is avoided, and the operation safety of the energy storage system is 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] In order to cope with climate change and achieve low-carbon transformation of energy systems, countries around the world are actively promoting the construction of renewable energy, and battery energy storage systems are being promoted. Lithium-ion batteries have received extensive attention in battery energy storage systems due to their high energy density, long cycle life, low self-discharge rate, and low environmental pollution, and are one of the main energy carriers.

[0003] However, the widespread use of lithium-ion batteries also brings potential safety hazards. Thermal runaway of lithium-ion batteries will generate a lot of heat and a large amount of flammable and toxic gases, which will cause fires and explosions, resulting in serious loss of life and property. Among them, the main cause of thermal runaway of lithium-ion batteries is overcharging. During the operation of the battery, it is very important to monitor the overcharge state. Therefore, there is an urgent need for a method that can quickly monitor and warn of overcharge thermal runaway of lithium-ion batteries. Summary of the invention

[0004] In order 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, an early warning device and a processing device, which can timely detect the problem of lithium-ion overcharge thermal runaway, avoid the problem of lithium-ion battery overcharge causing thermal runaway and even explosion and fire, and ensure the operation 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 a 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] Acquire the 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 amplitude of the electrochemical impedance or the real amplitude of the electrochemical impedance meets a preset condition.

[0011] Optionally, generating overcharge warning information according to the imaginary amplitude of the electrochemical impedance or the real amplitude of the electrochemical impedance meeting 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 3 times the minimum imaginary part amplitude of the lithium-ion battery during this charging process.

[0014] Optionally, generating overcharge warning information according to the imaginary amplitude of the electrochemical impedance or the real amplitude of the electrochemical impedance meeting 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 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 sound prompt information or display prompt information.

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

[0023] A charging module, used for performing direct current charging on the lithium-ion battery and injecting an alternating current power source having a frequency of the single-point frequency into the lithium-ion battery;

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

[0025] An electrochemical impedance acquisition module, used to acquire the electrochemical impedance of the lithium-ion battery according to the voltage component and the current component;

[0026] The overcharge warning information generating module is used 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, which stores a program or instruction, and the program or instruction 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, including 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] Compared with the prior art, the technical solution provided by the embodiments of the present disclosure has the following advantages:

[0030] The embodiment of the present disclosure provides a lithium-ion battery overcharge thermal runaway early warning method, early warning device and storage medium, the lithium-ion battery overcharge thermal runaway early warning method comprises: obtaining the electrochemical impedance spectrum of the lithium-ion battery, and obtaining a single-point frequency in the low-frequency region of the electrochemical impedance spectrum; DC charging the lithium-ion battery, and injecting an AC 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 according to the voltage component and the current component; generating overcharge early warning information according to the imaginary amplitude of the electrochemical impedance or the real amplitude of the electrochemical impedance meeting the preset conditions. 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, and the overcharge early warning information is generated according to the imaginary amplitude of the electrochemical impedance or the real amplitude of the electrochemical impedance meeting the preset conditions, so that the problem of lithium-ion overcharge thermal runaway can be discovered in time, and the problem of thermal runaway caused by overcharging of the lithium-ion battery, resulting in explosion and fire, can be avoided, and the operation safety of the energy storage system is ensured. 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 invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0033] Figure 1 A schematic diagram 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 spectrum of a lithium-ion battery provided in an embodiment of the present disclosure;

[0035] Figure 3 A schematic diagram of changes in the imaginary part and the 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 diagram of the structure 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 in the embodiments can be combined with each other without 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 the related technologies, electrochemical impedance spectroscopy, as an important characteristic parameter of lithium-ion batteries, has received extensive attention in the application of characterizing the status of lithium-ion batteries, especially in overcharge warning, which is of great significance for preventing lithium-ion batteries from overcharging and triggering thermal runaway, and can ensure the safe operation of energy storage power stations. However, it takes a long time to obtain the electrochemical impedance spectrum of lithium-ion batteries, and it is difficult to reflect the status of lithium-ion batteries in a timely manner in practical applications, which will cause the problem of untimely monitoring of the overcharge thermal runaway status of lithium-ion batteries.

[0041] In order to solve the above problems, the present disclosure provides a lithium-ion battery overcharge thermal runaway early warning method. Figure 1 A flowchart of a lithium-ion battery overcharge thermal runaway warning method provided in an embodiment of the present disclosure. The lithium-ion battery overcharge thermal runaway warning method can be applied to application scenarios where it is necessary to determine whether a lithium-ion battery has thermal runaway. The method can be executed by a lithium-ion battery overcharge thermal runaway warning device provided in 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, 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] Exemplarily, the lithium-ion battery is discharged to a cut-off voltage of 2.5 V, corresponding to a state of charge of 0%, and is 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 an electrochemical impedance spectrum of a lithium-ion battery provided in an embodiment of the present disclosure, such as Figure 2 As shown, Figure 2 The horizontal axis is the real part of the electrochemical impedance, in microohms, and the vertical axis is the imaginary part of the electrochemical impedance, in microohms. 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 are used to schematically divide the low-frequency region. The low-frequency region is the region showing the Warburg impedance characteristics, that is, due to the diffusion of ions in the electrolyte, the real and imaginary parts of the electrochemical impedance will present a straight line with a slope of 45° in the low-frequency region.

[0045] Since the lower the frequency of the electrochemical impedance spectrum, the more electrochemical reaction information it contains, the more accurate the monitoring of overcharge thermal runaway of lithium-ion batteries is, which can further improve the accuracy of overcharge thermal runaway warning. Therefore, a single-point frequency is obtained in the low-frequency region of the electrochemical impedance spectrum, for example, 1 Hz. The specific value of the selected single-point frequency is not limited in the embodiments of the present disclosure.

[0046] It should be noted that the lithium-ion battery used in the embodiments 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 embodiments of the present disclosure.

[0047] S102, performing direct current charging on the lithium-ion battery, and injecting an alternating current power source having 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, obtaining a voltage component and a current component of the lithium-ion battery under an AC power supply.

[0051] Specifically, the current passing through the lithium-ion battery is obtained by a current detection device such as a current sensor, and the voltage passing through the lithium-ion battery is obtained by a voltage detection device such as a voltage sensor. The current and voltage of the lithium-ion battery are processed using discrete Fourier transform to extract the current component and voltage component of the lithium-ion battery under a frequency of 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 a lithium-ion battery under a 1Hz AC power supply k Satisfies the following formula:

[0056]

[0057] Among them, v n is the sampling signal of the voltage of the lithium-ion battery 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 It is the current component of the lithium-ion battery under the 1Hz AC power supply.

[0062] S105 , 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.

[0063] The disclosed embodiment improves the monitoring speed by real-time online monitoring of the single-point frequency electrochemical impedance of the lithium-ion battery, monitors the overcharge state of the battery based on the change characteristics of the real and imaginary parts of the electrochemical impedance, generates overcharge warning information according to whether the amplitude of the imaginary part of the electrochemical impedance or the amplitude of the real part of the electrochemical impedance meets the preset conditions, and can timely discover the problem of thermal runaway of lithium-ion overcharge, avoid the problem of thermal runaway caused by overcharge of lithium-ion batteries and thus explosion and fire, and ensure the operation safety of the energy storage system.

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

[0065] Specifically, when the imaginary amplitude of the electrochemical impedance is greater than the first amplitude threshold, it means that the current balance inside the lithium-ion battery is broken, resulting in an increase in the imaginary amplitude. The lithium-ion battery is about to enter an overcharge state but has not fully entered the overcharge state, and the first-level overcharge warning information is generated, 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 3 times the minimum 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 the 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 microohms; the vertical axis on the right is the real impedance amplitude, in microohms. Figure 3 From the impedance imaginary part curve corresponding to the single-point frequency of 1Hz, it can be seen that before the state of charge is charged to 100%, the minimum imaginary part amplitude is 7 microohms. When the impedance imaginary part amplitude rises to 22, which is greater than 3 times the minimum imaginary part amplitude, the state of charge of the lithium-ion battery is 100.4%, indicating that the lithium-ion battery has an overcharge problem, and the first-level overcharge warning information is generated.

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

[0069] Specifically, when the real amplitude of the electrochemical impedance is greater than the second amplitude threshold, it means that the electrochemical side reactions inside the lithium-ion battery are already very serious and the lithium-ion battery has deeply entered an overcharge state. Therefore, a second-level overcharge warning information is generated, thereby 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 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 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 to 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 the 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 or display prompt information.

[0076] Exemplarily, the overcharge problem of the lithium-ion battery can be prompted by sound prompts, 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 buzzer can be emitted to remind relevant personnel that the lithium-ion battery is overcharged.

[0077] The overcharge problem of the lithium-ion battery can also be indicated by displaying a prompt, for example, a picture can be displayed, and the picture content includes overcharge prompt text and other prompting content, which is not limited in the embodiments of the present disclosure. For example, a light can also be emitted, such as a flashing light or a continuous light, to indicate that the lithium-ion battery is overcharged.

[0078] The disclosed embodiment improves the monitoring speed by real-time online monitoring of the single-point frequency electrochemical impedance of the lithium-ion battery, monitors the overcharge state of the battery based on the change characteristics of the real and imaginary parts of the electrochemical impedance, generates overcharge warning information according to whether the amplitude of the imaginary part of the electrochemical impedance or the amplitude of the real part of the electrochemical impedance meets the preset conditions, and can timely discover the problem of thermal runaway of lithium-ion overcharge, avoid the problem of thermal runaway caused by overcharge of lithium-ion batteries and thus explosion and fire, and ensure the operation safety of the energy storage system.

[0079] The disclosed embodiment also provides 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 acquire the electrochemical impedance spectrum of the lithium-ion battery and acquire 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 acquire the voltage component and the current component of the lithium-ion battery under the AC power supply; the electrochemical impedance acquisition module 404 is used to acquire the electrochemical impedance of the lithium-ion battery according to the voltage component and the current component; the overcharge warning information generation module 405 is used to generate overcharge warning information according to whether the imaginary part of the electrochemical impedance or the real part of the electrochemical impedance meets the preset conditions.

[0081] The device provided in the above-mentioned embodiment of the present disclosure and the method provided in the embodiment of the present disclosure are based on the same inventive concept and have the same beneficial effects, which will not be elaborated here.

[0082] The present disclosure also provides a processing device, Figure 5 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 may 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 can be 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 of 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 warning method provided in the embodiment of the present disclosure by calling the program or instruction 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. In the implementation process, each step of the above method can be completed by the hardware integrated logic circuit in the processor 501 or the instructions in the form of software. The above-mentioned processor 501 can be a general-purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application-specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field programmable gate array (Field Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. 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 embodiment of the present disclosure can be directly embodied as being executed by a hardware decoding processor, or being executed by a combination of hardware and software units in the decoding processor. The software unit can be located in a mature storage medium in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 502, and the processor 501 reads the information in the memory 502 and completes the steps of the method in combination with its hardware.

[0087] The processing device may also include one entity component, or multiple entity components, according to the 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 entity components can be set in the processing device, or outside the processing device, such as a cloud server. Each entity component cooperates with the processor 501 and the memory 502 to realize 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, and 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, the computer executable instructions, when executed by a computer processor, can also be used to execute the technical solution 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, the technical personnel in the relevant field can clearly understand that the present disclosure can be implemented by means of software and necessary general hardware, and of course it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present disclosure is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as a computer's floppy disk, read-only memory (ROM), random access memory (RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods of each embodiment of the present disclosure.

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

[0092] The above are only specific embodiments of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to these embodiments herein, but will conform to the widest scope 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 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 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; Acquire the electrochemical impedance of the lithium-ion battery according to the voltage component and the current component; Overcharge warning information is generated according to whether the imaginary amplitude of the electrochemical impedance or the real amplitude of the electrochemical impedance meets a preset condition.

2. The lithium-ion battery overcharge thermal runaway early warning method according to claim 1, characterized in that: The generating overcharge warning information according to the imaginary amplitude of the electrochemical impedance or the real amplitude of the electrochemical impedance meeting a preset condition includes: According to the imaginary part amplitude of the electrochemical impedance being greater than the first amplitude threshold, first level overcharge warning information is generated.

3. The lithium-ion battery overcharge thermal runaway early warning method according to claim 2, characterized in that: The first amplitude threshold is 3 times the minimum imaginary part amplitude of the lithium-ion battery during the current charging process.

4. The lithium-ion battery overcharge thermal runaway early warning method according to claim 1, characterized in that: The generating overcharge warning information according to the imaginary amplitude of the electrochemical impedance or the real amplitude of the electrochemical impedance meeting a preset condition includes: According to the real part amplitude of the electrochemical impedance being greater than the second amplitude threshold, second-level overcharge warning information is generated.

5. The lithium-ion battery overcharge thermal runaway early warning method according to claim 4, characterized in that: The second amplitude threshold is 1.1 times the lowest real amplitude of the lithium-ion battery during the current charging process.

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

7. 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 sound prompt information or display prompt information.

8. A lithium-ion battery overcharge thermal runaway warning device, characterized in that: include: A single-point frequency acquisition module is used to acquire an electrochemical impedance spectrum of a lithium-ion battery, and acquire a single-point frequency in a low-frequency region of the electrochemical impedance spectrum; A charging module, used for performing direct current charging on the lithium-ion battery and injecting an alternating current power source having a frequency of the single-point frequency into the lithium-ion battery; A component acquisition module, used to acquire the voltage component and current component of the lithium-ion battery under the AC power supply; An electrochemical impedance acquisition module, used to acquire the electrochemical impedance of the lithium-ion battery according to the voltage component and the current component; The overcharge warning information generating module is used 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.

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

10. A processing device, characterized in that: The invention comprises a processor and a memory, wherein the processor executes the steps of the lithium-ion battery overcharge thermal runaway early warning method as claimed in any one of claims 1 to 7 by calling a program or instruction stored in the memory.

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