Method and device for identifying thermal accident in battery pack and battery pack system

Abstract

A method, apparatus and battery pack system for identifying a thermal accident in a battery pack having a plurality of battery cells, the method comprising the steps of: acquiring a first potential difference of a positive electrode of the battery pack with respect to a reference potential and / or a second potential difference of a negative electrode of the battery pack with respect to the reference potential; wherein a thermal accident is detected if there is a deviation between the first potential difference and the first reference potential difference or if there is a deviation between the second potential difference and the second reference potential difference. According to the method and the device, the thermal event in the battery pack can be accurately identified while high robustness is achieved.

Description

Background Art

[0002] In electric vehicles, the battery pack acts as a power battery to provide driving power for the vehicle and is one of the key components of electric vehicles. Due to its own electrochemical characteristics, especially when affected by external factors such as overcharging, high temperature, short circuit, external impact, etc., the battery pack is prone to thermal runaway or thermal diffusion and threatens the operating safety of electric vehicles. For this reason, relevant laws, regulations and standards in various countries and regions require that an alarm message be sent to the user in a timely manner when an accident that may cause thermal runaway or thermal diffusion occurs inside the battery pack. Therefore, it is very important to accurately and promptly identify thermal runaway or thermal diffusion in the battery pack.

[0003] Most current evaluation algorithms use the temperature and voltage of the battery cell as input parameters to determine whether thermal runaway has occurred. However, in the event of a real thermal runaway or thermal diffusion event, the battery cell in question will naturally be at a high temperature, and the measurement circuits or sensors in the battery cell may fail or even burn out, making it impossible to provide reliable data. Voltage alone cannot reliably determine thermal runaway, because voltage does not change rapidly in many cases.

[0004] Timely identification of thermal accidents and sending alarm information to users is crucial to the safety of vehicle occupants. Therefore, there is an urgent need to improve existing methods for detecting thermal runaway and thermal diffusion accidents in battery packs. Summary of the invention

[0005] The present application proposes a method, device, battery pack system and electric vehicle for identifying thermal accidents in a battery pack, which can overcome some or all of the technical problems in the above-mentioned prior art.

[0006] According to one aspect, the present application relates to a method for identifying a thermal accident in a battery pack having a plurality of battery cells, the method comprising the following steps: obtaining a first potential difference of a positive electrode of the battery pack relative to a reference potential and / or a second potential difference of a negative electrode of the battery pack relative to a reference potential; wherein, when there is a deviation between the first potential difference and the first reference potential difference or between the second potential difference and the second reference potential difference, a thermal accident is identified. Here, a thermal accident refers to a thermal runaway or thermal diffusion event in a battery pack. A battery cell can be understood here as a battery cell or a battery module composed of a plurality of battery cells. That is, if the battery pack is directly composed of battery cells, the method can be applied at the cell level, and if the battery pack is composed of a battery module composed of a plurality of battery cells, the method can also be applied at the battery module level. In the method, each battery cell or each battery module is considered as a whole in the above two cases.

[0007] In another aspect, the present application also relates to a device for identifying thermal accidents in a battery pack, the device comprising a processor and a memory for storing executable instructions of the processor; wherein the processor is configured to execute the executable instructions to implement any one of the implementation forms of the method in the present application.

[0008] The present application also relates to a battery pack system, which includes a battery pack for driving an electric vehicle and the above-mentioned device for identifying thermal accidents in the battery pack.

[0009] In addition, the present application also provides a computer-readable storage medium on which a computer program is stored. The computer program includes executable instructions. When the executable instructions are executed by a processor, an implementation form of the method according to the present application is implemented.

[0010] The present application also relates to an electric vehicle having any one of the embodiments of the aforementioned battery pack system.

[0011] The present application is based on the recognition that, in the event that a thermal event in the form of thermal runaway or thermal diffusion occurs in a battery cell in a battery pack, the battery cell will experience insulation failure due to the high temperature and will therefore be grounded. Since the internal battery cells are grounded, the potential difference between the positive and negative electrodes of the battery pack relative to a reference potential, such as the ground potential, will change accordingly. By analyzing and evaluating this change, it is possible to identify whether thermal runaway or thermal diffusion has occurred in the battery pack, and the location of the battery cell where the thermal accident occurred can be accurately inferred. Since the potential difference between the positive and negative electrodes of the battery pack relative to the reference potential can be measured outside the battery pack, it can be reliably measured without being affected by the high temperature occurring inside the battery pack. Therefore, the method and apparatus of the present application can accurately identify thermal events in the battery pack while having high robustness. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The above and other features and advantages of the present application will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.

[0013] Figure 1 is a flow chart of an implementation form of the method according to the present application;

[0014] Figure 2 It is a schematic diagram for measuring the potential difference between the positive and negative electrodes of a battery pack relative to a reference potential;

[0015] Figure 3 A schematic diagram of a battery pack with thermal runaway inside is shown;

[0016] Figure 4 A schematic diagram of a battery pack showing heat diffusion occurring inside;

[0017] Figure 5 A schematic structural diagram of a device for identifying a thermal accident in a battery pack according to an embodiment of the present invention is shown. Specific implementation plan

[0018] The exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the contents of this application comprehensive and complete and to fully convey the concepts of the exemplary embodiments to those skilled in the art. In the drawings, the size of some elements may be exaggerated or deformed for the purpose of clarity. The same reference numerals in the drawings represent the same or similar structures, and their detailed descriptions will be omitted.

[0019] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, elements, etc. can be adopted. In other cases, known structures, methods or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0020] Figure 1 A flow chart of an embodiment of a method according to the present application is shown, which is used to identify thermal events in the form of thermal runaway or thermal diffusion in a battery pack. The battery pack can be a power battery for an electric vehicle, or it can be other stationary or movable energy storage devices for storing electrical energy. The battery pack has a plurality of battery cells. These battery cells can be combined into battery modules as subunits of the battery pack, or they can be directly arranged in the battery pack as units of the battery pack, that is, the battery pack is directly composed of a plurality of battery cells.

[0021] like Figure 1As shown, in the method, in order to identify possible thermal runaway or thermal diffusion in the battery pack, a first potential difference of the positive electrode of the battery pack relative to a reference potential and / or a second potential difference of the negative electrode of the battery pack relative to a reference potential are obtained, wherein a thermal accident is identified when there is a deviation between the first potential difference and the first reference potential difference or when there is a deviation between the second potential difference and the second reference potential difference. The method can be executed on any processor with data processing capabilities, such as an onboard computer or a vehicle controller, or even on a server outside the vehicle, such as a remote server or a cloud server. When the method is executed on an external server, only data related to the first potential difference and / or the second potential difference needs to be transmitted to the external server. After the external server performs analysis and evaluation on the received data, it transmits the evaluation results back to the vehicle and issues an alarm to the user, such as the driver or passenger, through an acoustic or optical device on the vehicle when a thermal accident is identified. The advantage of performing analysis and processing on an external server is that it does not occupy the computing power of the vehicle itself, and for example, vehicle manufacturers or fleet operators can remotely monitor and record possible thermal accidents of battery packs of many vehicles and accumulate a large amount of data information in various states, so that the accuracy of analysis and evaluation can be further improved based on big data analysis.

[0022] Here, the reference potential is only used as a reference benchmark and can be any potential, but is preferably ground potential, such as vehicle ground potential. At present, there are detection circuits in electric vehicles that monitor the potential difference between the positive and negative poles of the battery pack relative to the ground potential, for example, to measure the total voltage of the battery pack or perform periodic insulation monitoring. Therefore, without the need for additional special hardware, the relevant data of the first potential difference and the second potential difference can be obtained directly from the vehicle through a communication connection in a low-cost manner. In addition, the measurement of the first potential difference and the second potential difference is completely independent of the battery management system and is performed outside the battery, so even in the event of a thermal accident in the battery pack, it will not be affected by adverse factors such as high temperature.

[0023] The data acquisition of the first potential difference and / or the second potential difference can be performed continuously or periodically. An analysis and evaluation is performed based on the latest acquired first potential difference and / or second potential difference, and a thermal runaway or thermal diffusion accident occurring in the battery pack is identified based on the evaluation result. For a specific battery pack, under normal conditions, the potential difference between the positive and negative electrodes of the battery pack relative to the ground potential is a known fixed value. For example, for a battery pack with a total voltage of 300V, under normal conditions, the potential difference between the positive electrode and the ground potential is 150V, and the potential difference between the negative electrode and the ground potential is -150V. Therefore, the known fixed values ​​can be used as the first reference potential difference and the second reference potential difference. During the analysis and evaluation, the first potential difference is evaluated based on the predetermined first reference potential difference and / or the second potential difference is evaluated based on the predetermined second reference potential difference; wherein, when the deviation between the first potential difference and the first reference potential difference or the deviation between the second potential difference and the second reference potential difference exceeds a predetermined threshold, a thermal accident is identified. The predetermined threshold value may be, for example, between 3% and 7% of the first or second reference potential difference, preferably 5%. The predetermined threshold value can take into account measurement errors, subtle effects of the external environment on the performance of the battery pack, and so on, to prevent misjudgment. Here, "and / or" means that the first potential difference and the second potential difference can be analyzed and evaluated separately, or the first and second potential differences can be evaluated at the same time. This is because the grounding of the battery cell in the battery pack due to thermal runaway or thermal diffusion usually affects the potential difference of the positive and negative electrodes of the battery pack relative to the reference potential at the same time. Therefore, only by evaluating the potential difference of the obtained positive or negative electrode can it be known whether a thermal accident has occurred. However, in order to improve the reliability of the analysis results, the potential difference of the positive and negative electrodes relative to the ground potential can be analyzed and evaluated at the same time.

[0024] Advantageously, the location of the battery cell where the thermal accident occurred can be inferred based on the first potential difference and / or the second potential difference while taking into account information about the battery pack. Information about the battery pack is, for example, the rated voltage of each battery cell in the battery pack and the connection mode between the battery cells (such as series or parallel connection) or other parameters that may affect the potential difference of the positive or negative electrode of the battery pack relative to the reference potential. For example, the location of the battery cell where the thermal accident occurred can be inferred based on the difference between the first potential difference and the first reference potential difference and the connection relationship of each battery cell. Or the location of the battery cell where the thermal accident occurred can be inferred based on the difference between the second potential difference and the second reference potential difference and the connection relationship of each battery cell. Or the location of the battery cell where the thermal accident occurred can be inferred based on the difference between the first potential difference and the second potential difference and the connection relationship of each battery cell. The values ​​of the first potential difference and the second potential difference under normal circumstances are known, for example, they can be the same.

[0025] Figure 2A schematic circuit diagram for measuring the potential difference between the positive and negative electrodes of the battery pack 2 relative to the ground potential 1 is shown. The positive and negative electrodes of the battery pack 2 are connected to the first measuring resistor R+ and the second measuring resistor R- through wires 3 and 4, respectively. The first measuring resistor R+ and the second measuring resistor R- are connected to the ground potential 1, respectively. By measuring the potential difference across the first measuring resistor R+ and the second measuring resistor R-, the potential difference between the positive and negative electrodes of the battery pack 2 relative to the ground potential 1 can be obtained.

[0026] Figure 3 The battery pack 2 in which thermal runaway has occurred is shown as an example. The battery pack 2 includes six battery cells 21, 22, 23, 24, 25 and 26. Here, the battery cell is a battery module composed of a plurality of single-cell monomers. These battery cells 21, 22, 23, 24, 25 and 26 are constructed identically and have a voltage of 50V respectively. However, the battery cells may also be constructed differently and have different voltages. However, for a specific battery pack, the specific parameters of each battery cell are known. For example, Figure 3 As shown, these six battery cells are connected in series to form a battery pack 2. Therefore, a voltage of 300V is provided between the positive and negative electrodes of the battery pack 2. Under normal circumstances, the potential difference of the positive electrode of the battery pack 2 relative to the ground potential is 150V, and the potential difference of the negative electrode thereof relative to the ground potential is -150V.

[0027] exist Figure 3 In the case shown, the fifth battery cell 25, starting from the positive electrode, has a thermal runaway event and generates high temperature. The high temperature causes the fifth battery cell 25 to have an insulation failure and be grounded. The insulation failure of the fifth battery cell 25 affects the potential difference between the positive and negative electrodes of the battery pack 2 relative to the ground potential. At this time, the measured first potential difference of the positive electrode of the battery pack 2 relative to the ground potential is 225V, and the second potential difference of its negative electrode relative to the ground potential is -75V.

[0028] In the method according to the present application, if it is found through analysis for the first time that both the first potential difference and the second potential difference have large deviations relative to their reference potential difference, it means that a battery cell in the battery pack is grounded. Experience has shown that sudden and persistent insulation failures are largely due to thermal runaway of the battery cell. Therefore, in this case, it can be identified that thermal runaway is likely to have occurred in the battery pack.

[0029] In order to further improve the accuracy of identification and distinguish thermal runaway from simple insulation failure, the temperature and / or voltage information of the battery cell can be additionally considered during the analysis and evaluation process. The temperature and voltage of the battery cell can be obtained from the battery management system (BMS) of the battery pack, especially from the battery cell management controller (CMC) of the battery management system. If it is found that the potential difference between the positive and / or negative electrodes of the battery pack 2 and the ground potential 1 has changed significantly, and the temperature and / or voltage data of the battery cell obtained at this time is normal, it can be concluded that only an insulation failure has occurred, and there is no thermal runaway or heat diffusion. However, if the temperature and / or voltage data at this time are also abnormal or completely missing, it can be concluded that thermal runaway has occurred and affected the collection of temperature and voltage data.

[0030] After thermal runaway is identified, an alarm signal may be generated and sent to the vehicle electronic system so as to promptly warn the user, for example, by acoustic, optical or tactile means to prompt the user to stop the vehicle as soon as possible and leave the vehicle.

[0031] After thermal runaway is identified, the location of the battery cell where thermal runaway occurs can be further inferred based on the acquired potential difference and the connection relationship between the various battery cells. Figure 3 In the case shown, the first potential difference of the positive electrode of the battery pack 2 relative to the ground potential is 225V, and the second potential difference of the negative electrode relative to the ground potential 1 is -75V. Since the information of the battery pack (the voltage and connection mode of each battery cell) is known, based on the first potential difference of 225V and the series connection relationship between each battery cell, it can be calculated that the battery cell that has thermal runaway should be the fifth one from the positive electrode. Based on the second potential difference of -75V, it can also be calculated that the position of the battery cell that has a thermal accident is the second one from the negative electrode.

[0032] The method according to the present application is continuously or periodically performed, that is, the first potential difference and / or the second potential difference is continuously or periodically acquired. After the thermal runaway is first identified, if it is found again that the current first potential difference and / or the second potential difference continues to change relative to the first potential difference and / or the second potential difference acquired last time, or the deviation exceeds another predetermined threshold, it should be considered that the battery cell that previously experienced thermal runaway has affected other surrounding battery cells and caused the surrounding battery cells to have insulation failure and grounding, so thermal diffusion is identified.

[0033] Figure 4A schematic diagram of a battery pack 2 with internal heat diffusion is shown. In the illustrated case, the fifth battery cell 25 that has thermal runaway has affected the fourth battery cell 24 next to it, causing the fourth battery cell 24 to also have an insulation fault and be grounded. This means that heat diffusion has occurred. The grounding fault that occurred in the fourth battery cell 24 further causes the potential difference between the positive and negative electrodes of the battery pack 2 relative to the ground potential to change. For example, at this time, the first potential difference of the positive electrode of the battery pack 2 relative to the ground potential is 200V, and the second potential difference of the negative electrode relative to the ground potential is -100V. Similarly, based on the multiple first potential differences and / or second potential differences obtained, it can be inferred that a new battery cell has an insulation fault and is grounded. And similarly, based on the multiple first potential differences and / or second potential differences obtained and the connection relationship between the various battery cells, if necessary, considering other information about the battery pack, it is inferred that the position of another battery cell that has an insulation fault due to heat diffusion is the fourth battery cell 24. In the case of identifying heat diffusion, a higher level of alarm signal is preferably issued to the user of the vehicle.

[0034] Corresponding to the above-mentioned method for identifying thermal accidents in a battery pack, the present invention also provides a device for identifying thermal accidents in a battery pack. Figure 5 A schematic structural diagram of an exemplary configuration of such a device is shown. The device mainly includes a processor 510, and a memory 520 for storing executable instructions of the processor. Here, the processor 510 and the memory 520 form an identification and analysis device 500. The processor 510 is configured to execute the various steps of the method for identifying thermal accidents in a battery pack according to any of the above embodiments by executing the executable instructions. The identification and analysis device 500 can be implemented in the form of a general computing device (such as an on-board high-performance computer). The device may also include a potential difference acquisition device as described above and optionally a battery cell parameter acquisition device that interacts with the identification and analysis device 500. The potential difference acquisition device can obtain the potential difference between the positive and negative electrodes of the battery pack relative to the reference potential from the vehicle system under the control of the identification and analysis device 500. The battery cell parameter acquisition device can, for example, directly or indirectly obtain information such as the temperature and voltage of the battery cell from an external sensor under the control of the identification and analysis device 500. Of course, the device can also receive the required information from the outside only through an interface, so in some embodiments, the device may not include a dedicated potential difference acquisition device and a battery cell parameter acquisition device. For example, the device or the identification and analysis device 500 in the device can communicate with one or more other devices inside or outside the vehicle (such as a cloud server, other vehicle networking devices, etc.) through various network communication ports to obtain any required information. In addition, the device can also include an alarm signal generating device. The alarm generating device can send an alarm signal to the vehicle based on whether a thermal accident, such as thermal runaway or heat propagation, is identified.

[0035] In an exemplary embodiment of the present application, a computer-readable storage medium is also provided, on which a computer program is stored, the program including executable instructions, which can implement the steps of the method for identifying thermal accidents in a battery pack described in any of the above embodiments when executed by, for example, a processor. In some possible implementations, various aspects of the present application can also be implemented in the form of a program product, which includes a program code, and when the program product is run on a terminal device, the program code is used to cause the terminal device to execute the steps described in the method for identifying thermal accidents in a battery pack in this specification according to various exemplary embodiments of the present application.

[0036] The program product for implementing the above method according to the embodiment of the present application can adopt a portable compact disk read-only memory (CD-ROM) and include program code, and can be run on a terminal device, such as a personal computer. However, the program product of the present application is not limited thereto. In this document, a readable storage medium can be any tangible medium containing or storing a program, which can be used by or in combination with an instruction execution system, an apparatus or a device.

[0037] The program product may use any combination of one or more readable storage media. The readable storage medium may be a readable signal medium or a readable storage medium. The readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0038] The computer readable storage medium may include a data signal propagated in a baseband or as a part of a carrier wave, wherein a readable program code is carried. This propagated data signal may take a variety of forms, including but not limited to an electromagnetic signal, an optical signal, or any suitable combination of the above. The readable storage medium may also be any readable storage medium other than a readable storage medium, which may send, propagate, or transmit a program for use by an instruction execution system, an apparatus, or a device or used in combination with it. The program code contained on the readable storage medium may be transmitted with any appropriate medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination of the above.

[0039] Program code for performing the operations of the present application may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., using an Internet service provider to connect through the Internet).

[0040] In an exemplary embodiment of the present application, a battery pack system is also provided, which has a battery pack for storing electric energy and the aforementioned device for identifying a thermal accident in the battery pack. In addition, an electric vehicle is also provided, which has the aforementioned battery pack system.

[0041] Those skilled in the art will appreciate that various aspects of the present application may be implemented as a system, method or program product. Therefore, various aspects of the present application may be specifically implemented in the following forms, namely: a complete hardware implementation, a complete software implementation (including firmware, microcode, etc.), or a combination of hardware and software, which may be collectively referred to as "circuit", "module" or "system" herein.

[0042] It is easy for those skilled in the art to understand that the example implementation described here can be implemented by software or by combining software with necessary hardware. Therefore, the technical solution according to the implementation of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, including several instructions to enable a computing device (which can be a personal computer, a server, or a network device, etc.) to execute the method for identifying thermal accidents in a battery pack according to the implementation of the present application.

[0043] Those skilled in the art will readily appreciate other embodiments of the present application after considering the description and practicing the contents disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The description and embodiments are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the appended claims.

Claims

1. A method for identifying a thermal event in a battery pack having a plurality of battery cells, the method comprising the following steps: Acquire a first potential difference of the positive electrode of the battery pack relative to a reference potential and / or a second potential difference of the negative electrode of the battery pack relative to the reference potential; Therein, a thermal accident is detected when there is a deviation between the first potential difference and the first reference potential difference or when there is a deviation between the second potential difference and the second reference potential difference.

2. The method according to claim 1, characterized in that A thermal accident is detected only when a deviation between the first potential difference and the first reference potential difference or a deviation between the second potential difference and the second reference potential difference exceeds a respective predetermined threshold value.

3. The method according to claim 1, characterized in that The battery pack is a power battery of an electric vehicle, the reference potential is a vehicle ground potential, the thermal accident is thermal runaway or thermal diffusion, and the battery unit is a battery cell or a battery module composed of a plurality of battery cells.

4. The method according to claim 1 or 2, characterized in that: The position of the battery cell where the thermal accident occurs is inferred based on the deviation between the first potential difference and the first reference potential difference and the connection relationship between the respective battery cells.

5. The method according to claim 1 or 2, characterized in that: The position of the battery cell where the thermal accident occurs is inferred based on the deviation between the second potential difference and the second reference potential difference and the connection relationship between the respective battery cells.

6. The method according to claim 1 or 2, characterized in that: The position of the battery cell where the thermal accident occurred is inferred based on the difference between the first potential difference and the second potential difference and the connection relationship of the respective battery cells.

7. The method according to any one of claims 1 to 3, characterized in that The temperature and voltage of the battery cell are also acquired, wherein, if the acquired temperature and / or voltage data are abnormal, a thermal accident is identified; if the acquired temperature and / or voltage data are normal, an insulation fault is identified.

8. The method according to claim 1 or 2, characterized in that: The first potential difference and / or the second potential difference is continuously or periodically acquired, wherein thermal runaway is detected when a deviation between the first potential difference and a first reference potential difference or a deviation between the second potential difference and a second reference potential difference exceeding a predetermined threshold is first detected.

9. The method according to claim 8, characterized in that If, after the thermal runaway has been detected for the first time, it is again found that the deviation of the current first potential difference and / or second potential difference from the last detected first potential difference and / or second potential difference exceeds another predetermined threshold value, thermal diffusion is detected.

10. The method according to claim 8, characterized in that The position of the battery cell where heat diffusion occurs is inferred based on the acquired plurality of first potential differences and / or second potential differences and the connection relationship between the respective battery cells.

11. The method according to claim 1 or 2, characterized in that: If a thermal incident is detected, a warning signal is output to a user of the vehicle.

12. A device for identifying a thermal event in a battery pack, the device comprising a processor and a memory for storing executable instructions of the processor; wherein: The processor is configured to execute the executable instructions to implement the method according to any one of claims 1 to 11.

13. The apparatus for identifying a thermal event in a battery pack according to claim 12, wherein: The device comprises a potential difference acquisition device.

14. The device for identifying a thermal event in a battery pack according to claim 12 or 13, wherein: The device also includes a battery cell parameter acquisition device and / or an alarm signal generation device.

15. The device for identifying a thermal event in a battery pack according to claim 12 or 13, wherein: The device also includes at least one network communication port for communicating with another device inside or outside the vehicle. 16 . A computer-readable storage medium having a computer program stored thereon, the computer program comprising executable instructions, and when the executable instructions are executed by a processor, the method according to claim 1 is implemented.

17. A battery pack system comprising a battery pack for storing electric energy and a device. 18 . An electric vehicle having the battery pack system according to claim 17 .

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