Battery anomaly analysis method and related apparatus

Abstract

The application provides a battery abnormality analysis method and related device, and relates to the technical field of battery safety. The method comprises the following steps: obtaining voltage data of each single battery cell in a battery pack, the voltage data comprising a target voltage obtained based on a voltage difference between a voltage of a pole of the single battery cell and a third voltage of a shell of the single battery cell, the target voltage comprising a first target voltage obtained based on the voltage of the negative pole; analyzing whether the single battery cell is abnormal according to the target voltage of the single battery cell, and when the single battery cell is abnormal, comparing the first target voltage with a first preset value to obtain a comparison result, the first preset value being determined based on a potential of a negative electrode material of the single battery cell relative to a reference electrode; and generating abnormal prompt information of a corresponding abnormality degree according to the comparison result. In this way, a specific abnormal single battery cell can be identified at an early stage of abnormality, and abnormal prompt information of a corresponding abnormality degree can be generated to enable relevant personnel to understand the situation.

Description

Technical Field

[0001] This application relates to the field of battery safety technology, and more specifically, to a battery anomaly analysis method and related apparatus. Background Technology

[0002] Current battery anomaly detection methods typically rely on whether the insulation resistance value of the battery pack is abnormal to determine if the pack has experienced insulation failure. However, this method cannot determine whether the insulation anomaly is caused by a single battery cell within the battery-related system or by other structural factors (e.g., in a vehicle's high-voltage system, it could be caused by onboard wiring). If the insulation of a single battery cell in the battery-related system is abnormal, it can easily lead to safety issues such as battery pack thermal runaway. Furthermore, this detection method cannot pinpoint the exact location of the fault, thus failing to rule out individual cell anomalies or confirm the location of the faulty cell. Additionally, this method cannot identify anomalies in their early stages. Summary of the Invention

[0003] This application provides a battery anomaly analysis method and related apparatus, which can identify specific abnormal individual cells in the early stages of anomalies and generate anomaly prompts of corresponding anomaly levels so that relevant personnel can understand the situation, thereby reducing safety problems caused by battery pack thermal runaway due to individual cell anomalies.

[0004] The embodiments of this application can be implemented as follows: In a first aspect, embodiments of this application provide a battery anomaly analysis method, the method comprising: For each individual cell in the battery pack, voltage data of that individual cell is obtained, wherein the voltage data includes a target voltage obtained based on the voltage difference between the voltage of the individual cell's terminal and the third voltage of the individual cell's casing, and the target voltage includes a first target voltage obtained based on the voltage of the negative terminal. Based on the target voltage of the individual battery cell, analyze whether the individual battery cell is abnormal; If the single cell is determined to be abnormal, the first target voltage is compared with a first preset value to obtain a comparison result, wherein the first preset value is determined based on the potential of the negative electrode material of the single cell relative to the reference electrode. Based on the comparison results, anomaly alerts of the corresponding degree of abnormality are generated.

[0005] Secondly, embodiments of this application provide a battery monitoring system, the system including a sampling harness and processing equipment. The sampling harness is used to collect the original voltage data of the battery pack. The original voltage data includes the voltage of each sampling point and includes at least one of the first voltage of the positive terminal and the second voltage of the negative terminal of each individual cell in the battery pack, as well as the third voltage of the casing. The processing device is configured to obtain voltage data for each individual cell in the battery pack based on the original voltage data. The voltage data includes a target voltage derived from the voltage difference between the voltage of the cell's terminal and a third voltage of the cell's casing. The target voltage includes a first target voltage derived from the voltage of the negative terminal. Based on the target voltage of the individual cell, the device analyzes whether the cell is abnormal. If the cell is determined to be abnormal, the device compares the first target voltage with a first preset value to obtain a comparison result. The first preset value is determined based on the potential of the negative electrode material of the individual cell relative to a reference electrode. Based on the comparison result, the device generates an abnormality alert indicating the degree of abnormality.

[0006] Thirdly, embodiments of this application provide a battery anomaly analysis device, the device comprising: The data acquisition module is used to acquire voltage data for each individual cell in the battery pack. The voltage data includes a target voltage obtained based on the voltage difference between the voltage of the cell's terminal and the third voltage of the cell's casing. The target voltage includes a first target voltage obtained based on the voltage of the negative terminal. The analysis module is used to analyze whether the single cell is abnormal based on the target voltage of the single cell; The processing module is used to compare the first target voltage with a first preset value when it is determined that the single cell is abnormal, and obtain a comparison result, wherein the first preset value is determined based on the potential of the negative electrode material of the single cell relative to the reference electrode. The processing module is also used to generate anomaly prompt information of corresponding abnormality level based on the comparison result.

[0007] Fourthly, embodiments of this application provide an electronic device, including a processor and a memory, wherein the memory stores machine-executable instructions that can be executed by the processor, and the processor can execute the machine-executable instructions to implement the battery anomaly analysis method described in any of the foregoing embodiments.

[0008] Fifthly, embodiments of this application provide a readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the battery anomaly analysis method as described in any of the foregoing embodiments.

[0009] The battery anomaly analysis method and related apparatus provided in this application first obtain voltage data for each individual cell in the battery pack. Then, based on the target voltage in the voltage data, the method analyzes whether the individual cell is abnormal. If an anomaly is determined, the method compares a first target voltage with a first preset value to obtain a comparison result. Based on this comparison result, an anomaly warning message of corresponding degree of anomaly is generated. The voltage data includes a target voltage obtained based on the voltage difference between the voltage of the cell's terminal and the third voltage of the cell's casing. The target voltage includes a first target voltage obtained based on the voltage of the negative terminal. The first preset value is determined based on the potential of the negative electrode material of the cell relative to a reference electrode. Thus, based on the target voltage obtained from the voltage difference between the voltage of the cell's terminal and the third voltage of the cell's casing, specific abnormal individual cells can be identified in the early stages of anomalies, and an anomaly warning message of corresponding degree of anomaly can be generated to inform relevant personnel of the situation, thereby reducing safety problems caused by thermal runaway of the battery pack due to individual cell anomalies. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the voltage recording of a leaking battery cell; Figure 2 This is a schematic diagram of the relevant voltages of the cells in a battery pack with insulation abnormalities. Figure 3 This is a block diagram of the battery monitoring system provided in an embodiment of this application; Figure 4 This is a schematic diagram of the sampling harness used to acquire voltage from a battery module. Figure 5 This is a schematic diagram of the structure of a single battery cell provided in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of a battery module with a sampling harness provided in an embodiment of this application; Figure 7 This is a schematic diagram showing the setup of the first sampling terminal for a battery module with a structure of 2 parallel and 5 series. Figure 8 A block diagram illustrating an electronic device provided in an embodiment of this application; Figure 9 A flowchart illustrating the battery anomaly analysis method provided in this application embodiment; Figure 10 for Figure 9 One of the flowcharts illustrating the sub-steps included in step S200; Figure 11 for Figure 10 A flowchart illustrating the sub-steps included in the neutron step S212; Figure 12 for Figure 9 The second flowchart of the sub-steps included in step S200; Figure 13 for Figure 12 A flowchart illustrating the sub-steps included in the neutron step S222; Figure 14 This is a block diagram of a battery anomaly analysis device provided in an embodiment of this application.

[0012] Icons: 10-Battery monitoring system; 100-Sampling harness; 112-First sampling terminal; 114-Second sampling terminal; 116-Voltage sampling line; 120-Harness board; 121-Port; 200-Processing equipment; 301-Parallel unit; 310-Single cell; 311-Positive terminal; 313-Negative terminal; 315-Explosion-proof valve; 320-Battery plate; 400-Electronic equipment; 410-Memory; 420-Processor; 430-Communication unit; 500-Battery anomaly analysis device; 510-Data acquisition module; 520-Analysis module; 530-Processing module. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0014] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0015] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0016] Current vehicle battery packs are designed with insulation between the high-voltage system and the vehicle body ground. The power lines of the high-voltage system are not directly connected to the vehicle body ground, and good insulation must be ensured between them. Insulation resistance between the power lines and the vehicle body ground is detected by an insulation monitoring circuit. Current battery pack insulation detection primarily relies on the insulation resistance values ​​connected to the positive and negative terminals of the battery pack. When either of these resistance values ​​falls below a set safety threshold, an insulation anomaly warning is triggered. However, this method has a significant drawback: after an insulation anomaly is triggered, the location of the insulation failure cannot be directly identified. The battery pack casing must be manually opened to confirm the specific location of the insulation anomaly. If the insulation anomaly is caused by several individual cells in the high-voltage system, the arcing caused by the massive energy impact at the moment of insulation failure could lead to thermal runaway of the battery pack. Furthermore, this method cannot identify anomalies in their early stages.

[0017] Currently, the full voltage of the cells in a battery pack is used to determine whether the battery pack performance is abnormal or whether there is a potential risk of thermal runaway. The inventors of this application have discovered that the method of detecting anomalies based on cell voltage is, in one scenario, difficult to detect cell voltage anomalies in the early stages of failure, even though the failure is ongoing: a short circuit caused by the contact between the negative electrode and the cell casing. This situation is as follows: In the case of a damaged cell casing, after leakage and standing for about one and a half months, the full voltage of the cell measured at room temperature during this period did not show significant anomalies; the voltage only fluctuated with temperature changes. The full voltage of the cell represents the difference between the positive and negative electrode voltages of the cell.

[0018] When the insulation between the negative electrode of the battery cell and the casing fails, the casing voltage gradually approaches the negative electrode voltage. During the charging process, the negative electrode potential continuously decreases, and the casing potential also decreases accordingly. When the potential drops below the lithium intercalation potential of the aluminum casing (0.2V), aluminum casing corrosion occurs inside the cell. With repeated charge and discharge cycles of the battery pack, the aluminum casing cracks, and electrolyte leaks. The electrolyte, passing through the bottom plate of the cell, causes contact between the cell casings or between the cell casing and the battery pack's metal frame, leading to insulation failure in the battery pack. At this point, the leaked electrolyte evaporates, and if an arc is generated instantaneously due to the insulation failure between the high-voltage system containing the cell and the vehicle frame, it could potentially cause instantaneous thermal runaway of the battery pack. However, in the early stages of the insulation warning, the battery voltage signal shows no abnormalities.

[0019] To verify whether cell leakage affects cell voltage changes, specifically whether the cell's full voltage fails after electrochemical corrosion and leakage at the vehicle end, the inventors of this application tested the voltage of several self-made leaking cells at 30% SOC (State of Charge) under laboratory room temperature conditions. The leak was caused by physically damaging the battery casing. During a month and a half of testing, the voltage of the leaking cells was as follows: Figure 1 As shown, the voltages of the four tested cells (V1~V4) from the same batch (same SOC) did not show significant abnormalities, only fluctuating slightly with temperature changes, indicating that abnormalities in the overall cell voltage are difficult to detect in the early stages of leakage. Among them, Figure 1 The corresponding laboratory room temperature can be referenced from the weather temperature in Wuhan during the period from November 23, 2022 to January 8, 2023.

[0020] The inventors of this application have also discovered that when a single battery cell is damaged and leaks liquid due to electrochemical corrosion, although the voltage of the single battery cell is no different from that of a normal battery cell, the negative electrode-casing voltage and the positive electrode-casing voltage of the single battery cell are significantly abnormal. In this description, battery cell voltage refers to the total voltage of the battery cell; negative electrode-casing voltage refers to the voltage of the casing minus the voltage of the negative electrode; and positive electrode-casing voltage refers to the voltage of the positive electrode minus the voltage of the casing.

[0021] Through testing, in a battery pack with insulation abnormalities, the voltage information of the individual cell that has experienced electrochemical corrosion and leakage, as well as the voltage information of the individual cells physically adjacent to that cell, are as follows: Figure 2As shown. Battery pack 1 includes three sample cells: samples 1-3. Among them, sample 1 has a total voltage (i.e., full voltage) of 3.572, a positive electrode-casing voltage of 3.348, and a negative electrode-casing voltage of 0.224; sample 2 has a total voltage of 3.571, a positive electrode-casing voltage of 1.16, and a negative electrode-casing voltage of 2.41; and sample 3 has a total voltage of 3.575, a positive electrode-casing voltage of 1.386, and a negative electrode-casing voltage of 2.188. Battery pack 2 includes three sample cells: samples 1-3. Sample 1 has a total voltage of 3.677 kJ / m², a positive electrode-to-casing voltage of 3.677 kJ / m², and a negative electrode-to-casing voltage of 0 kJ / m². Sample 2 has a total voltage of 3.678 kJ / m², a positive electrode-to-casing voltage of 1.465 kJ / m², and a negative electrode-to-casing voltage of 2.212 kJ / m². Sample 3 has a total voltage of 3.679 kJ / m², a positive electrode-to-casing voltage of 1.274 kJ / m², and a negative electrode-to-casing voltage of 2.404 kJ / m².

[0022] Among them, sample 1# in battery pack 1 and battery pack 2 were both electrochemically corroded and leaking cells, and sample 2# in battery pack 2 was adjacent to sample 1#. Figure 2 The voltage information shown indicates that the negative electrode-casing voltage of the leaking cell is significantly lower than the outlier, while the positive electrode-casing voltage is significantly higher than the outlier.

[0023] As can be seen from the above description, based on the internal experimental cycle and voltage data of the leaking sample caused by electrochemical corrosion, it can be seen that in the early stage of leakage, the abnormality cannot be detected by the full voltage of the battery alone. However, in the case of leakage caused by electrochemical corrosion, the abnormality can be detected by the residual negative electrode-shell voltage and positive electrode-shell voltage of the individual cell.

[0024] Based on the above analysis, this application provides a battery anomaly analysis method and related apparatus, which can identify specific abnormal individual cells in the early stage of anomalies based on the target voltage obtained by the voltage difference between the voltage of the terminal of the individual cell and the third voltage of the casing of the individual cell, and can generate anomaly prompt information of corresponding degree of anomaly so that relevant personnel can understand the situation, thereby reducing safety problems caused by thermal runaway of the battery pack due to individual cell anomalies.

[0025] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0026] Please refer to Figure 3 , Figure 3This is a block diagram of the battery monitoring system 10 provided in this embodiment. In this embodiment, the battery monitoring system 10 can be communicatively connected to a sampling harness 100 and a processing device 200. The sampling harness 100 can be one or more, depending on the arrangement of individual cells in the battery pack. For example, one sampling harness can be used for one battery pack, or each battery module in one battery pack can use its own sampling harness. The processing device 200 can be a server, a terminal device in the vehicle where the battery pack is located, a control device for an energy storage system, etc. The battery pack can be a power battery pack in a vehicle or a battery pack in an energy storage battery system.

[0027] The sampling harness 100 is used to collect the raw voltage data of the battery pack. The raw voltage data includes the voltage at each sampling point, and includes at least one of the first voltage of the positive terminal and the second voltage of the negative terminal of each individual cell in the battery pack, and the third voltage of the casing. The processing device 200 is used to obtain the voltage data of each individual cell in the battery pack based on the raw voltage data. The voltage data includes a target voltage obtained based on the voltage difference between the voltage of the individual cell's terminal and the third voltage of the individual cell's casing. The target voltage includes a first target voltage obtained based on the voltage of the negative terminal. Based on the target voltage of the individual cell, the device analyzes whether the individual cell is abnormal. If the individual cell is determined to be abnormal, the device compares the first target voltage with a first preset value to obtain a comparison result. The first preset value is determined based on the potential of the negative electrode material of the individual cell relative to a reference electrode. Based on the comparison result, the device generates an abnormality warning message indicating the corresponding degree of abnormality.

[0028] Please refer to Figure 4 , Figure 4 This is a schematic diagram of a sampling harness 100 used for voltage acquisition from a battery module. The sampling harness 100 may include: multiple sampling terminals and corresponding voltage sampling lines 116, and a harness board 120. The multiple sampling terminals include multiple first sampling terminals 112 and second sampling terminals 114. The first sampling terminals 112 are used to directly or indirectly connect to the positive or negative terminal of a single battery cell to obtain a first voltage at the positive terminal and a second voltage at the negative terminal. The second sampling terminals 114 are used to connect to the casing of a single battery cell to obtain a third voltage on the casing of the single battery cell. The multiple sampling terminals are respectively connected to the harness board 120 through their respective corresponding voltage sampling lines 116. The harness board 120 includes a port 121 through which the obtained voltage-related data can be sent to the processing device.

[0029] like Figure 5As shown, a single battery cell 310 may include a positive terminal 311, a negative terminal 313, an explosion-proof valve 315, etc. When the sampling harness 100 is based on a single battery cell 310, that is, when the sampling harness 100 corresponds one-to-one with a single battery cell 310, there can be three voltage sampling points on a single battery cell: the first voltage sampling point—positive terminal 311, the second voltage sampling point—negative terminal 313, and the third voltage sampling point—a point on the casing (i.e., the casing sampling point). In the structure of the single battery cell 310, the top cover and the side casing of the single battery cell 310 are connected and have the same potential. Therefore, the third sampling point can be located in any non-terminal area of ​​the battery cell, that is, the third voltage sampling point can be located on any metal point on the non-terminal area casing of the single battery cell.

[0030] As one possible implementation, the third voltage sampling point is located at a non-polar metal site on the target side where the positive terminal 311 or the negative terminal 313 is located. Correspondingly, the length of the voltage sampling line 116 corresponding to the third voltage sampling point matches the length of the housing sampling point on the target side. This reduces the cost of the voltage sampling line.

[0031] When the sampling harness 100 is based on individual battery cells 310, in the case of... Figure 5 When the positive terminal 311 and negative terminal 313 are located on the top cover of the single cell 310, the casing sampling point can also be located on the top cover. Adjustments can be made flexibly when there are differences in the terminal design, but the principle of three sampling points must be maintained. If the positive terminal 311 is located at one end of the single cell 310 and the negative terminal 313 is located at the other end of the single cell 310, such as in a blade battery, the casing sampling point can be set in the non-terminal area on the positive terminal side or in the non-terminal area on the negative terminal side. For the same product, the location of the casing sampling point can be standardized to facilitate production.

[0032] Since individual battery cells 310 typically exist in a series-parallel structure within the battery pack, as a possible implementation to reduce the number of sampling terminals, in this embodiment, the plurality of first sampling terminals 112 include a first sampling terminal 112 for connection to the positive terminal of each parallel unit, and a first sampling terminal 112 for connection to the negative terminal of the parallel unit at the negative terminal in the series structure composed of parallel units. Here, the aforementioned parallel unit represents the smallest parallel unit; in a fully series structure, the smallest parallel unit is one individual battery cell; in a series-parallel structure, such as n parallel to m series (m and n are both positive integers), the smallest parallel unit includes n parallel individual battery cells.

[0033] like Figure 4 and Figure 6As shown, a battery module includes 6 parallel units 301. Adjacent parallel units 301 are connected by a switch plate 320. Each parallel unit 301 includes only one single cell. The sampling harness 100 corresponding to the battery module includes 7 first sampling terminals and 6 second sampling terminals. The 7 first sampling terminals are respectively connected to a switch plate 320, and the 6 second sampling terminals are respectively connected to the casing of a single cell.

[0034] For a battery module, traditional voltage sampling harnesses only collect the voltage at the terminal positions of each parallel unit. In this solution, in addition to collecting the voltage at the terminal sides of the parallel units, the sampling harness also includes sampling terminals for collecting the cell casing voltage, thus fully capturing the voltage division state of the parallel units. It is worth noting that regardless of whether the smallest parallel unit is a single cell, the number of battery casing voltage sampling lines (i.e., the voltage sampling lines corresponding to the second sampling terminal) for each battery module is always equal to the number of single cells in that battery module. For example, if a battery module has 10 single cells, and the module structure is 1 parallel and 10 series, the number of the first sampling terminal and its corresponding voltage sampling lines is 11, and the number of the second sampling terminal and its corresponding voltage sampling lines is 10; when the module structure is 2 parallel and 5 series, such as... Figure 7 As shown, the first sampling terminal ( Figure 7 The triangle in the diagram represents the third sampling terminal, and the number of its corresponding voltage sampling lines is 6. The number of the second sampling terminal and its corresponding voltage sampling lines is 10.

[0035] The raw voltage data of the battery pack can be obtained through the sampling harness, which includes the voltage at each sampling point. The processing device 200 can obtain the voltage data of each individual battery cell based on the raw voltage data. This voltage data can include the total voltage, a first target voltage, and a second target voltage. The total voltage is the value obtained by subtracting the voltage of the negative terminal from the voltage of the positive terminal, i.e., the voltage at the first sampling point minus the voltage at the second sampling point. The first target voltage is the value obtained by subtracting the voltage of the negative terminal from the voltage of the casing, i.e., the voltage at the third sampling point minus the voltage at the second sampling point. The second target voltage is the value obtained by subtracting the voltage of the casing from the voltage of the positive terminal, i.e., the voltage at the first sampling point minus the voltage at the third sampling point. Then, based on the above voltage data, it can be determined whether each individual battery cell is abnormal, and an abnormality warning message of the corresponding degree of abnormality can be generated when an abnormality occurs.

[0036] Please refer to Figure 8 , Figure 8This is a block diagram of an electronic device 400 provided in an embodiment of this application. The electronic device 400 can serve as the aforementioned processing device 200. The electronic device 400 may include a memory 410, a processor 420, and a communication unit 430. The memory 410, processor 420, and communication unit 430 are electrically connected directly or indirectly to each other to achieve data transmission or interaction. For example, these components can be electrically connected to each other through one or more communication buses or signal lines.

[0037] The memory 410 is used to store programs or data. The memory 410 may be, but is not limited to, random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc.

[0038] The processor 420 is used to read / write data or programs stored in the memory 410 and execute corresponding functions. For example, the memory 410 stores a battery anomaly analysis device 500, which includes at least one software function module that can be stored in the memory 410 in the form of software or firmware. The processor 420 executes various functional applications and data processing by running the software programs and modules stored in the memory 410, such as the battery anomaly analysis device 500 in this embodiment, thereby implementing the battery anomaly analysis method in this embodiment.

[0039] The communication unit 430 is used to establish a communication connection between the electronic device 400 and other communication terminals through the network, and to send and receive data through the network.

[0040] It should be understood that, Figure 8 The structure shown is only a schematic diagram of the electronic device 400. The electronic device 400 may also include components that are larger than... Figure 8 The more or fewer components shown, or having the same Figure 8 The different configurations shown. Figure 8 The components shown can be implemented using hardware, software, or a combination thereof.

[0041] Please refer to Figure 9 , Figure 9This is a flowchart illustrating the battery anomaly analysis method provided in this application embodiment. The method can be applied to the aforementioned electronic device. The specific flow of the battery anomaly analysis method is described in detail below. In this embodiment, the method may include steps S100 to S400.

[0042] Step S100: Obtain the voltage data of each individual cell in the battery pack.

[0043] In this embodiment, the battery pack includes multiple individual battery cells, and the voltage data of each individual battery cell can be obtained in any way. For example, the voltage data of each individual battery cell can be directly received from other devices, or the original voltage data of the battery pack can be processed to obtain the voltage data of each individual battery cell. The voltage data includes a target voltage, which is a target voltage obtained based on the voltage difference between the voltage of the terminal of the individual battery cell and the third voltage of the cell's casing. The target voltage includes a first target voltage based on the voltage of the negative terminal, that is, a first target voltage obtained based on the voltage difference between the voltage of the negative terminal and the third voltage of the casing. In other words, the first target voltage of a single battery cell is the value obtained by subtracting the second voltage of the negative terminal of the individual battery cell from the third voltage of the cell's casing.

[0044] Step S200: Analyze whether the single cell is abnormal based on the target voltage of the single cell.

[0045] As described above, when a single battery cell leaks, the terminal-to-casing voltage of that cell differs from that of a normal cell. Therefore, for each individual cell, its target voltage can be used to analyze and determine whether the cell is abnormal. Optionally, the specific method for anomaly analysis based on the target voltage can be determined according to actual needs.

[0046] Step S300: If it is determined that the single cell is abnormal, the first target voltage is compared with the first preset value to obtain the comparison result.

[0047] Step S400: Generate an anomaly prompt message with the corresponding degree of anomaly based on the comparison result.

[0048] When an anomaly is identified in a single battery cell, a first target voltage for that cell can be compared with a first preset value to determine whether the first target voltage is less than the first preset value, thus obtaining a comparison result. The comparison result indicates the magnitude relationship between the first target voltage and the first preset value. The first preset value is determined based on the potential of the negative electrode material of the single battery cell relative to a reference electrode. When the single battery cell is a lithium battery, the first preset value is determined based on the lithium potential of the negative electrode material of the single battery cell. For example, if the negative electrode of the single battery cell uses graphite, and the lithium intercalation potential of this material is 0.005~1.5V, then the first preset value corresponding to the lithium battery can be set to 1.5V.

[0049] The magnitude relationship indicates the degree of the anomaly. Anomaly alerts can be generated based on the comparison results, indicating the corresponding degree of anomaly. For example, a severe anomaly can trigger a warning, while a minor anomaly can trigger a notification.

[0050] In this way, based on the target voltage obtained by the voltage difference between the voltage of the terminal of the individual cell and the third voltage of the cell casing, the specific abnormal individual cell can be identified in the early stage of the anomaly, and the corresponding abnormality warning information can be generated so that relevant personnel can understand the situation, thereby reducing the safety problems caused by thermal runaway of the battery pack due to abnormal individual cells.

[0051] As one possible implementation, the initial voltage data of the battery pack can be obtained through the real-time signal of the sampling harness described above. The initial voltage data includes at least one of the first voltage of the positive terminal and the second voltage of the negative terminal of each individual cell in the battery pack, and the third voltage of the casing. Optionally, when obtaining the initial voltage data, the corresponding time and the position information of each individual cell can be obtained simultaneously, thus facilitating the subsequent indication of the location of abnormal cells.

[0052] After obtaining the initial voltage data, it can be processed according to the data required for anomaly analysis to obtain the necessary data. For example, the initial voltage data can be processed to obtain the full voltage, first target voltage, and second target voltage of a single cell. The full voltage is the value obtained by subtracting the second voltage of the negative terminal from the first voltage of the positive terminal of the single cell; the first target voltage is the value obtained by subtracting the second voltage of the negative terminal from the third voltage of the casing of the single cell; and the second target voltage is the value obtained by subtracting the third voltage of the casing from the first voltage of the positive terminal of the single cell.

[0053] As one possible implementation, such as Figure 10 As shown, anomaly analysis can be performed based on the first target voltage of each individual cell. Please refer to... Figure 10 , Figure 10for Figure 9 One of the flowcharts for the sub-steps included in step S200. In this embodiment, step S200 may include sub-steps S211 to S215. Sub-steps S211 to S214 may be executed in parallel or sequentially, and the specific execution order can be determined according to actual needs.

[0054] Sub-step S211: Determine whether the first target voltage is less than the first preset value.

[0055] The negative electrode of a lithium-ion single-cell battery is generally made of graphite, which has a lithium intercalation potential of 0.005~1.5V. If the negative electrode-casing voltage is lower than 1.5V, the casing potential is within the negative electrode's lithium intercalation potential window. During charging, lithium ions enter the negative electrode and react with the aluminum casing simultaneously. Based on the above analysis, for lithium batteries, a corresponding first preset value can be set to 1.5V. If the first target voltage is less than the first preset value of 1.5V, a short circuit between the negative electrode and the casing is determined. If the battery is of other types, the corresponding first preset value can be set in the same way.

[0056] Sub-step S212: Based on the first target voltage of other individual cells in the battery pack, determine whether the first target voltage of the individual cell meets the preset voltage reduction condition.

[0057] When a single battery cell leaks electrolyte, the first target voltage of the leaking cell is lower than the first target voltage of other cells. Based on this, a preset voltage reduction condition can be set, the specific of which can be determined according to actual needs. During anomaly analysis, the first target voltage of the first cell can be compared with the first target voltages of other cells in the battery pack to determine whether the first target voltage of the first cell meets the preset voltage reduction condition.

[0058] As one possible implementation method, it can be achieved through Figure 11 The method shown determines whether the first target voltage of this single battery cell meets the preset voltage reduction condition. Please refer to... Figure 11 , Figure 11 for Figure 10 A flowchart illustrating the sub-steps included in neutron step S212. In this embodiment, sub-step S212 may include sub-steps S2121 to S212.

[0059] Sub-step S2121: Calculate the first average value of the first target voltage of other individual cells in the battery pack, and calculate the first decrease value of the first target voltage of the individual cell compared with the first average value, and determine whether the first decrease value is greater than a second preset value.

[0060] Sub-step S2122: Sort the individual cells in the battery pack in ascending order based on the corresponding first target voltage to obtain a first sorting result, and determine whether the sorting position of the individual cell gradually moves forward and remains in the first position based on the first sorting result and the first historical sorting result.

[0061] Sub-step S2123: If at least one of the above judgments is yes, then it is determined that the preset voltage decrease condition is met.

[0062] In this embodiment, the average value of the first target voltage of other individual cells in the battery pack at the same time is calculated as the first average value. The first target voltage of the individual cell is subtracted from the first average value, and the result is used as the first decrease value, that is, the first decrease value represents the decrease in the first target voltage of the individual cell compared to the first average value. It is determined whether the first decrease value is greater than a second preset value. If it is greater, it is determined that the preset voltage decrease condition is met. The second preset value can be determined in combination with the voltage range of the full voltage of the individual cell. For example, 1 / 5 to 1 / 8 of the full battery voltage range is a significant difference. The second preset value can be set based on 1 / 5 to 1 / 8 of the full battery voltage range, for example, set to 0.5V, so as to avoid false alarms caused by the threshold being too small.

[0063] When the first target voltage of a single battery cell gradually decreases over time and remains at its minimum, the insulation between the negative electrode of that single cell and the casing may be abnormal. Based on this analysis, the following processing can be performed: According to the first target voltage of each battery cell in the battery pack at the current moment, the cells are sorted in ascending order of their first target voltage to obtain a first sorting result. The first sorting results obtained in the same manner before the current moment are the first historical sorting results. Based on the first historical sorting results and the first sorting results corresponding to the current moment, it is determined whether the sorting position of the currently targeted single battery cell is gradually moving forward and remains at the first position. If so, it is determined that the preset voltage decrease condition is met.

[0064] If the judgment results of the above sub-steps S2121 and S2122 are both negative, it can be determined that the first target voltage of the single cell does not meet the preset voltage reduction condition.

[0065] Sub-step S213: Based on the first target voltage of the single cell and the first target historical voltage under the same state of charge (SOC) as the current state, determine whether the voltage decreases over time and whether the second decrease value of the first target voltage compared to the initial first target historical voltage is greater than a third preset value.

[0066] In this embodiment, with the ambient temperature close to the target, a first target voltage and a first target historical voltage at the same current SOC can be obtained for the individual battery cell. Furthermore, a second decrease in the first target voltage compared to the initial first target historical voltage of the individual battery cell is calculated, which is the initial first target historical voltage minus the first target voltage. Based on the first target voltage and the first target historical voltage of the individual battery cell, it is determined whether the voltage decreases as time approaches the current state and whether the second decrease is greater than a third preset value. The method for setting the third preset value is the same as that for setting the second preset value; it can be determined based on actual needs, or the second and third preset values ​​can be directly set to be the same.

[0067] Sub-step S214: Determine whether the target ratio of the first target voltage to the second target voltage is less than a fourth preset value.

[0068] Typically, the casing potential is close to the positive electrode potential, i.e., (negative electrode - casing voltage) / (positive electrode - casing voltage) > 1. The closer the casing voltage is to the positive electrode, the lower the probability of casing corrosion. When (negative electrode - casing voltage) / (positive electrode - casing voltage) < 1, it means the probability of casing corrosion increases. Based on the above analysis, the ratio of the first target voltage to the second target voltage of the single cell can be calculated as the target ratio. Then, it is determined whether this target ratio is less than a fourth preset value. The fourth preset value is greater than or equal to 1, and can be set according to actual needs.

[0069] Sub-step S215: If the result of at least one of the above judgments is yes, then the single cell is determined to be abnormal.

[0070] If at least one of sub-steps S211 to S214 yields a yes result, then the individual cell is determined to be abnormal. If all of the sub-steps S211 to S214 yield no results, the individual cell can be directly determined to be normal, or its abnormality can be determined by combining other analyses.

[0071] As another possible implementation method, it is possible to... Figure 12 As shown, anomaly analysis is performed based on the second target voltage analysis of this single cell. Please refer to... Figure 12 , Figure 12 for Figure 9 The second flowchart illustrates the sub-steps included in step S200. In this embodiment, step S200 may include sub-steps S221 to S225. Sub-steps S211 to S214 may be executed in parallel or sequentially, and the specific execution order can be determined according to actual needs.

[0072] Sub-step S221: Calculate the difference between the full voltage of the single cell and the second target voltage, and determine whether the difference is less than the first preset value.

[0073] In this embodiment, the second target voltage of the single cell can be subtracted from the total voltage of the single cell to obtain the difference, and it can be determined whether the difference is less than the first preset value. That is, it is determined whether the condition of total voltage and positive electrode-casing voltage < first preset value is met.

[0074] Sub-step S222: Based on the second target voltage of other individual cells in the battery pack, determine whether the second target voltage of the individual cell meets the preset voltage increase condition.

[0075] As one possible implementation method, it can be achieved through Figure 13 The method shown determines whether the second target voltage of the individual battery cell meets the preset voltage increase condition. Please refer to... Figure 13 , Figure 13 for Figure 12 A flowchart illustrating the sub-steps included in neutron step S222. In this embodiment, sub-step S222 may include sub-steps S2221 to S2223.

[0076] Sub-step S2221: Calculate the second average value of the second target voltage of other individual cells in the battery pack, and calculate the first increase value of the second target voltage of the individual cell compared with the second average value, and determine whether the first increase value is greater than a second preset value.

[0077] Sub-step S2222: Sort the individual cells in the battery pack in descending order based on the corresponding second target voltage to obtain a second sorting result, and determine whether the sorting position of the individual cell gradually moves forward and remains in the first position based on the second sorting result and the second historical sorting result. Sub-step S2223: If at least one of the above judgments is yes, then it is determined that the preset voltage increase condition is met.

[0078] In this embodiment, if the judgment result of sub-step S2221 is yes, or the judgment result of sub-step S2222 is yes, then it is determined that the second target voltage of the single cell meets the preset voltage increase condition. If the judgment results of both sub-step S2221 and sub-step S2222 are no, then it is determined that the second target voltage of the single cell does not meet the preset voltage increase condition.

[0079] Sub-step S223: Based on the second target voltage of the single cell and the second target historical voltage under the same state of charge (SOC) as the current state, determine whether the voltage increases over time and whether the second increase value of the second target voltage compared to the initial second target historical voltage is greater than a third preset value.

[0080] Sub-step S224: Determine whether the target ratio of the first target voltage to the second target voltage is less than the fourth preset value.

[0081] The fourth preset value is greater than or equal to 1.

[0082] Sub-step S225: If the result of at least one of the above judgments is yes, then the single cell is determined to be abnormal.

[0083] In this embodiment, if at least one of the judgment results of sub-steps S221 to S225 is yes, then the individual cell is determined to be abnormal. If the judgment results of sub-steps S221 to S225 are all no, then the individual cell can be directly determined to be normal, or the abnormality of the individual cell can be determined by combining other analyses. The processing procedures of sub-steps S221 to S225 are similar to those of sub-steps S211 to S215. For a detailed description of sub-steps S221 to S225, please refer to the previous description of sub-steps S211 to S215, which will not be repeated here.

[0084] In this embodiment, the abnormality of a single battery cell can be determined through sub-steps S211-S214 and / or sub-steps S221-S224. Optionally, if lightweight operation is required, the abnormality of a single battery cell can be analyzed using only sub-steps S211-S214 or sub-steps S221-S224. If lightweight operation is required while ensuring the accuracy of the analysis results, the abnormality of a single battery cell can be analyzed using sub-steps S211-S214. If lightweight operation is not required, the abnormality of a single battery cell can be analyzed using both sub-steps S211-S214 and sub-steps S221-S224. Specifically, when making judgments in sub-steps S211~S214 and S221~S224, if the judgment result of any one of the sub-steps S211~S214 and S221~S224 is yes, then the individual cell can be determined to be abnormal; conversely, if the judgment results of all sub-steps S211~S214 and S221~S224 are no, then the individual cell can be determined to be normal.

[0085] If a single battery cell is determined to be abnormal, its first target voltage can be compared with a first preset value to obtain a comparison result. If the comparison result indicates that the first target voltage is less than the first preset value, it is determined that the insulation between the negative terminal and the casing of the single battery cell is abnormal, i.e., the single battery cell has a short circuit, and a first abnormality warning message is generated. This first abnormality warning message is used to warn of a negative terminal insulation abnormality and includes the location information of the single battery cell. If the comparison result indicates that the first target voltage is not less than the first preset value, a second abnormality warning message is generated. This second abnormality warning message is used to alert the user of the single battery cell abnormality and includes the location information of the single battery cell. The generated abnormality warning messages can be sent to relevant terminal devices for display to notify relevant personnel.

[0086] Optionally, when the battery pack is applied to a vehicle, if the comparison result indicates that the first target voltage is not less than the first preset value, the vehicle can be added to the endpoint focus pool so that staff can focus on that vehicle. If the comparison result indicates that the first target voltage is less than the first preset value, a generated first anomaly alert can be sent to the terminal of the backend operations personnel to indicate that the battery pack needs to be returned for testing.

[0087] In typical battery sampling harness designs, the voltage sampling lines in the battery system only collect the positive and negative electrode voltages of the cells, without mentioning the addition of a third sampling line within each cell to collect the voltage in the non-terminal region. In this design, the voltage sampling lines also require the voltage in the non-terminal region of the cell, allowing for the detection of relevant signals as early as possible when an anomaly occurs in the cell through the terminal-casing voltage.

[0088] Current battery system insulation detection technologies cannot accurately pinpoint the location of specific cells with insulation failures. For example, while adding an external circuit might detect the module location of the heating film insulation failure, it cannot pinpoint the cell location. Another approach involves initial data collection for the battery system, followed by modeling based on the data. The model is then used to determine if the battery system has insulation failure and its location, and expert judgment is used to correct the model's findings. In contrast, this solution eliminates the need for additional circuits. Simply adding a sampling line and terminal for each individual cell within the battery system to collect the casing voltage, and connecting it to the existing circuitry, achieves efficient cell location. This requires no additional computing power or model investment, nor further expert judgment. This technology provides accurate and cost-effective location of faulty cells.

[0089] The above-mentioned solution provided in this embodiment not only collects the voltage on the terminal side of the individual cell, but also collects the voltage of the casing of the individual cell excluding the terminal area. It can accurately monitor the total voltage of each individual cell and the terminal-casing voltage of the cell. It can detect cell abnormalities in the high-voltage circuit before the battery pack issues an insulation failure warning, provide timely warnings, and accurately locate the abnormal cell. In other words, it can identify the faulty cell in the early stage of the abnormality.

[0090] In the early stages of cell negative electrode-top cover / outer shell insulation failure, the cell-level voltage (i.e., the cell's total voltage) does not show any abnormalities. Therefore, since the cell-level voltage cannot detect abnormalities, even after electrochemical corrosion begins and leakage starts, the cell's total voltage is difficult to distinguish from a normal cell. This solution allows for the identification of individual cell failures when insulation fails. Because a single cell typically undergoes several charge-discharge cycles from a negative electrode-outer shell short circuit to cell shell corrosion and leakage, this solution provides sufficient time to identify abnormally failing cells before individual cell failure / thermal runaway occurs. Therefore, it can reduce property damage and personnel safety threats caused by battery pack failure or even thermal runaway due to battery malfunctions.

[0091] To perform the corresponding steps in the above embodiments and various possible methods, an implementation of a battery anomaly analysis device 500 is given below. Optionally, the battery anomaly analysis device 500 can adopt the above-described... Figure 8 The device structure of the electronic device 400 shown is illustrated. Further, please refer to... Figure 14 , Figure 14 This is a block diagram of the battery anomaly analysis device 500 provided in this embodiment. It should be noted that the basic principle and technical effects of the battery anomaly analysis device 500 provided in this embodiment are the same as those in the above embodiments. For the sake of brevity, any parts not mentioned in this embodiment can be referred to the corresponding content in the above embodiments. In this embodiment, the battery anomaly analysis device 500 may include: a data acquisition module 510, an analysis module 520, and a processing module 530.

[0092] The data acquisition module 510 is used to obtain voltage data for each individual cell in the battery pack. The voltage data includes a target voltage obtained based on the voltage difference between the voltage of the cell's terminals and a third voltage of the cell's casing. The target voltage includes a first target voltage obtained based on the voltage of the negative terminal.

[0093] The analysis module 520 is used to analyze whether the single cell is abnormal based on the target voltage of the single cell.

[0094] The processing module 530 is used to compare the first target voltage with a first preset value when it is determined that the single cell is abnormal, and obtain a comparison result. The first preset value is determined based on the potential of the negative electrode material of the single cell relative to a reference electrode.

[0095] The processing module 530 is also used to generate anomaly prompt information of corresponding abnormality level based on the comparison result.

[0096] Optionally, the above modules can be stored in the form of software or firmware. Figure 8 The memory 410 shown is either stored in or embedded in the operating system (OS) of the electronic device 400, and can be used by... Figure 8 The processor 420 executes the program. Meanwhile, the data and program code required to execute the above modules can be stored in the memory 410.

[0097] This application also provides a readable storage medium storing a computer program thereon, which, when executed by a processor, implements the battery anomaly analysis method.

[0098] In summary, this application provides a battery anomaly analysis method and related apparatus. First, for each individual cell in the battery pack, voltage data of that individual cell is obtained. Then, based on the target voltage in the voltage data, the individual cell is analyzed to determine if it is abnormal. If an anomaly is determined, a first target voltage in the target voltage is compared with a first preset value to obtain a comparison result. Based on this comparison result, an anomaly warning message of corresponding degree of anomaly is generated. The voltage data includes a target voltage obtained based on the voltage difference between the voltage of the individual cell's terminal and the third voltage of the individual cell's casing. The target voltage includes a first target voltage obtained based on the voltage of the negative terminal. The first preset value is determined based on the potential of the negative electrode material of the individual cell relative to a reference electrode. Thus, based on the target voltage obtained from the voltage difference between the voltage of the individual cell's terminal and the third voltage of the individual cell's casing, specific abnormal individual cells can be identified in the early stages of anomaly, and an anomaly warning message of corresponding degree of anomaly can be generated to inform relevant personnel of the situation, thereby reducing safety problems caused by battery pack thermal runaway.

[0099] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0100] In addition, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0101] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0102] The above description is merely an optional embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery anomaly analysis method, characterized in that, The method includes: For each individual cell in the battery pack, voltage data of that individual cell is obtained, wherein the voltage data includes a target voltage obtained based on the voltage difference between the voltage of the individual cell's terminal and the third voltage of the individual cell's casing, and the target voltage includes a first target voltage obtained based on the voltage of the negative terminal. Based on the target voltage of the individual battery cell, analyze whether the individual battery cell is abnormal; If the single cell is determined to be abnormal, the first target voltage is compared with a first preset value to obtain a comparison result, wherein the first preset value is determined based on the potential of the negative electrode material of the single cell relative to the reference electrode. Based on the comparison results, anomaly alerts of the corresponding degree of abnormality are generated.

2. The method according to claim 1, characterized in that, The step of analyzing whether a single battery cell is abnormal based on its target voltage includes: Determine whether the first target voltage is less than the first preset value; Based on the first target voltage of other individual cells in the battery pack, determine whether the first target voltage of the individual cell meets the preset voltage decrease condition; Based on the first target voltage of the single cell and the first target historical voltage under the same state of charge (SOC) as the current state, it is determined whether the voltage decreases over time and whether the second decrease value of the first target voltage compared to the initial first target historical voltage is greater than a third preset value. Determine whether the target ratio of the first target voltage to the second target voltage is less than a fourth preset value, wherein the fourth preset value is greater than or equal to 1, and the target voltage also includes the second target voltage, which is obtained by subtracting the third voltage of the casing of the single cell from the second voltage of the positive terminal of the single cell. If the result of at least one of the above judgments is yes, then the individual battery cell is determined to be abnormal.

3. The method according to claim 2, characterized in that, The step of determining whether the first target voltage of a single cell meets the preset voltage reduction condition based on the first target voltage of other single cells in the battery pack includes: The first average value of the first target voltage of the other individual cells in the battery pack is calculated, and the first decrease value of the first target voltage of the individual cell compared with the first average value is calculated, and it is determined whether the first decrease value is greater than a second preset value. The individual cells in the battery pack are sorted in ascending order based on the corresponding first target voltage to obtain a first sorting result. Based on the first sorting result and the first historical sorting result, it is determined whether the sorting position of the individual cell gradually moves forward and remains in the first position. If at least one of the above judgments is true, then it is determined that the preset voltage decrease condition is met.

4. The method according to claim 1, characterized in that, The voltage data includes the total voltage obtained based on the voltages of the positive and negative terminals of a single battery cell. The target voltage also includes a second target voltage, which is obtained based on the voltage of the positive terminal. The step of analyzing whether a single battery cell is abnormal based on its target voltage includes: The difference between the full voltage of the single cell and the second target voltage is calculated, and it is determined whether the difference is less than the first preset value. Based on the second target voltage of other individual cells in the battery pack, determine whether the second target voltage of the individual cell meets the preset voltage increase condition; Based on the second target voltage of the single cell and the second target historical voltage at the same state of charge (SOC) as the current state, it is determined whether the voltage increases over time and whether the second increase in the second target voltage compared to the initial second target historical voltage is greater than a third preset value. Determine whether the target ratio of the first target voltage to the second target voltage is less than a fourth preset value, wherein the fourth preset value is greater than or equal to 1; If the result of at least one of the above judgments is yes, then the individual battery cell is determined to be abnormal.

5. The method according to claim 4, characterized in that, The step of determining whether the second target voltage of a single cell meets the preset voltage increase condition based on the second target voltage of other single cells in the battery pack includes: The second average value of the second target voltage of the other individual cells in the battery pack is calculated, and the first increase value of the second target voltage of the individual cell compared with the second average value is calculated, and it is determined whether the first increase value is greater than a second preset value. The individual cells in the battery pack are sorted in descending order based on the corresponding second target voltage to obtain a second sorting result. Based on the second sorting result and the second historical sorting result, it is determined whether the sorting position of the individual cell gradually moves forward and remains in the first position. If at least one of the above judgments is true, then it is determined that the preset voltage increase condition is met.

6. The method according to any one of claims 1-5, characterized in that, The step of generating an anomaly alert message with a corresponding degree of anomaly based on the comparison result includes: When the comparison result indicates that the first target voltage is less than the first preset value, it is determined that the negative electrode insulation of the single cell is abnormal, and a first abnormality prompt message is generated. The first abnormality prompt message is used to warn of the negative electrode insulation abnormality, and the first abnormality prompt message includes the location information of the single cell. When the comparison result indicates that the first target voltage is not less than the first preset value, a second abnormality prompt message is generated. The second abnormality prompt message is used to remind the individual cell of an abnormality, and the second abnormality prompt message includes the location information of the individual cell.

7. A battery monitoring system, characterized in that, The system includes a sampling harness and processing equipment. The sampling harness is used to collect the original voltage data of the battery pack. The original voltage data includes the voltage of each sampling point and includes at least one of the first voltage of the positive terminal and the second voltage of the negative terminal of each individual cell in the battery pack, as well as the third voltage of the casing. The processing device is configured to obtain voltage data for each individual cell in the battery pack based on the original voltage data. The voltage data includes a target voltage derived from the voltage difference between the voltage of the cell's terminal and a third voltage of the cell's casing. The target voltage includes a first target voltage derived from the voltage of the negative terminal. Based on the target voltage of the individual cell, the device analyzes whether the cell is abnormal. If the cell is determined to be abnormal, the device compares the first target voltage with a first preset value to obtain a comparison result. The first preset value is determined based on the potential of the negative electrode material of the individual cell relative to a reference electrode. Based on the comparison result, the device generates an abnormality alert indicating the degree of abnormality.

8. The system according to claim 7, characterized in that, The sampling harness includes multiple sampling terminals and corresponding voltage sampling lines. The multiple sampling terminals include multiple first sampling terminals and second sampling terminals. The multiple first sampling terminals include a first sampling terminal for connection to the positive terminal of each parallel unit, and a first sampling terminal for connection to the negative terminal of the parallel unit in the series structure composed of parallel units. The second sampling terminal is used to connect to the casing of a single battery cell, so that the sampling harness obtains a third voltage from the casing of the single battery cell; and / or, The sampling harness includes multiple sampling terminals and corresponding voltage sampling lines. The housing sampling point of the individual battery cell is located on the target side where the positive or negative terminal of the individual battery cell is located. The length of the voltage sampling line corresponding to the housing sampling point matches the housing sampling point on the target side.

9. A battery anomaly analysis device, characterized in that, The device includes: The data acquisition module is used to acquire voltage data for each individual cell in the battery pack. The voltage data includes a target voltage obtained based on the voltage difference between the voltage of the cell's terminal and the third voltage of the cell's casing. The target voltage includes a first target voltage obtained based on the voltage of the negative terminal. The analysis module is used to analyze whether the single cell is abnormal based on the target voltage of the single cell; The processing module is used to compare the first target voltage with a first preset value when it is determined that the single cell is abnormal, and obtain a comparison result, wherein the first preset value is determined based on the potential of the negative electrode material of the single cell relative to the reference electrode. The processing module is also used to generate anomaly prompt information of corresponding abnormality level based on the comparison result.

10. An electronic device, characterized in that, It includes a processor and a memory, the memory storing machine-executable instructions that can be executed by the processor, the processor executing the machine-executable instructions to implement the battery anomaly analysis method according to any one of claims 1-6.

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