Battery detection method, detection system, battery system and vehicle

Abstract

The application discloses a battery detection method, a detection system, a battery system and a vehicle in the technical field of batteries. The battery detection method comprises the following steps: acquiring signal values of multiple signals of a battery assembly; determining whether the signal values of each signal are abnormal respectively, and recording the time when the abnormality of the signal occurs when it is determined that the signal value of the signal is abnormal; the multiple signals comprise first signals and second signals, the first signals are signals representing the state of the shell of the battery assembly, and the second signals are signals representing the internal state of the battery assembly; and the cause of the abnormality is determined according to the time sequence relationship of the abnormality of the first signals and the second signals. Based on this, the embodiments of the application can trace the inducing cause of the abnormal event according to the order of the abnormality of the signals, and then provide decision basis for executing differentiated safety disposal measures for different abnormal causes, so that the accuracy of early warning and the effectiveness of emergency response are improved.

Description

Technical Field

[0001] This application belongs to the field of battery technology, and in particular relates to a battery testing method, testing system, battery system and vehicle. Background Technology

[0002] Lithium-ion batteries are widely used in electric vehicles, energy storage power stations, and consumer electronics due to their high energy density and long cycle life. However, frequent fires and explosions caused by thermal runaway have severely hampered their further promotion in scenarios with high safety requirements.

[0003] In related technologies, battery safety monitoring typically employs multiple detection methods to collect different signals from the battery components. Each detection method independently performs threshold judgment and alarms, and an anomaly is determined when any signal exceeds a set threshold. While the above monitoring scheme can detect the occurrence of abnormal events, the lack of effective correlation and collaborative analysis between the signals makes it impossible to determine the cause of the anomaly. Summary of the Invention

[0004] This application provides a battery detection method, detection system, battery system, and vehicle, which can trace the causes of abnormal events according to the order in which signal anomalies occur, thereby providing a basis for decision-making to implement differentiated safety measures for different causes of anomalies.

[0005] In a first aspect, embodiments of this application provide a battery detection method, including: Acquire the signal values ​​of multiple signals from the battery assembly; Determine whether the signal value of each signal is abnormal, and record the time when the signal value is determined to be abnormal; the multiple signals include a first type of signal and a second type of signal. The first type of signal is a signal that characterizes the shell state of the battery module, and the second type of signal is a signal that characterizes the internal state of the battery module. The cause of the anomaly is determined based on the timing relationship between the anomalies of the first and second type of signals.

[0006] According to any of the foregoing embodiments of the first aspect of this application, determining the cause of the anomaly based on the timing relationship between the occurrence of anomalies in the first type of signal and the second type of signal includes: If the first abnormality of the first type of signal occurs before the second abnormality of the second type of signal, and the time difference between the first abnormality and the second abnormality exceeds a first set duration, or if the signal value of the first type of signal is abnormal but the signal value of the second type of signal is not abnormal, the cause of the abnormality is determined to be shell damage. If the second abnormal transmission time of the second type of signal precedes the first abnormal occurrence time of the first type of signal, and the time difference between the first abnormal occurrence time and the second abnormal occurrence time exceeds the first set duration, or if the second type of signal is abnormal but the first type of signal is not abnormal, the cause of the abnormality is determined to be internal thermal runaway. If both the first and second types of signals are abnormal, and the time difference between the first abnormality of the first type of signal and the second abnormality of the second type of signal does not exceed the first set time, the cause of the abnormality is determined to be the combined effect of shell damage and thermal runaway.

[0007] According to any of the foregoing embodiments of the first aspect of this application, after determining the cause of the anomaly, the method further includes: If the cause of the anomaly is determined to be the combined effect of shell damage and thermal runaway, a first warning control command is generated. The first warning control command is used to control the actuator to perform at least one of the following operations: first prompt operation, power-off isolation operation, cooling operation, fire extinguishing operation, and emergency stop operation. If the cause of the anomaly is determined to be internal thermal runaway, a second early warning control command is generated. The second early warning control command is used to control the actuator to perform at least one of the following operations: a second prompt operation, a power-off isolation operation, a cooling operation, and a fire extinguishing operation. If the cause of the abnormality is determined to be shell damage, a third early warning control command is generated. The third early warning control command is used to control the actuator to perform at least one of the following operations: third prompt operation and power-off isolation operation.

[0008] According to any of the foregoing embodiments of the first aspect of this application, when the first abnormality of the first type of signal occurs before the second abnormality of the second type of signal, and the time difference between the first abnormality and the second abnormality exceeds a first preset duration, or when the signal value of the first type of signal is abnormal and the signal value of the second type of signal is not abnormal, determining the cause of the abnormality as shell damage includes: If the first abnormality of the first type of signal occurs before the second abnormality of the second type of signal, and the time difference between the first abnormality and the second abnormality exceeds a first set duration, the cause of the abnormality is determined to be damage to the first type of casing. If the signal value of the first type of signal is abnormal and the signal value of the second type of signal is not abnormal, the cause of the abnormality is determined to be damage to the second type of casing. If the cause of the anomaly is determined to be shell damage, a third early warning control command is generated, including: If the cause of the anomaly is determined to be damage to the first type of casing, a third early warning control command is generated; If the cause of the anomaly is determined to be damage to the second type of housing, a fourth early warning control command is generated. The fourth early warning control command is used to control the actuator to perform the fourth prompt operation.

[0009] According to any of the foregoing embodiments of the first aspect of this application, the first type of signal includes an optical signal, and the second type of signal includes at least one of a temperature signal, a pressure signal, and a gas concentration signal; Based on the timing relationship between the anomalies in the first and second types of signals, the cause of the anomaly is determined, including: If the occurrence of an anomaly in the optical signal precedes the occurrence of an anomaly in any of the temperature, pressure, and gas concentration signals, and the time difference exceeds a first set duration, the cause of the anomaly is determined to be a type of shell damage. When the optical signal is abnormal but the temperature, pressure and gas concentration signals are normal, the cause of the abnormality is determined to be damage to the second type of shell. If the anomaly in at least one of the temperature signal, pressure signal, and gas concentration signal occurs before the anomaly in the optical signal, and the time difference exceeds a first set duration, the cause of the anomaly is determined to be internal thermal runaway. If the time difference between the occurrence of an anomaly in at least one of the temperature signal, pressure signal, and gas concentration signal and the occurrence of an anomaly in the optical signal does not exceed a first set time, the cause of the anomaly is determined to be the combined effect of shell damage and thermal runaway.

[0010] According to any of the foregoing embodiments of the first aspect of this application, the second type of signal includes an electrochemical impedance spectroscopy signal; Obtain the signal value of the second type of signal, including: Obtain the impedance value of the electrochemical impedance spectroscopy signal at at least one target frequency; Determining whether the signal value of the second type of signal is abnormal includes: If the impedance value at the target frequency exceeds the corresponding set impedance threshold, it is determined that the electrochemical impedance spectroscopy signal is abnormal.

[0011] Secondly, embodiments of this application also provide a battery detection system, including: The acquisition module is used to acquire the signal values ​​of multiple signals from the battery assembly; The judgment module is used to judge whether the signal value of each signal is abnormal, and when the signal value is determined to be abnormal, the time of the abnormality is recorded. The multiple signals include a first type of signal and a second type of signal. The first type of signal is a signal that characterizes the shell state of the battery module, and the second type of signal is a signal that characterizes the internal state of the battery module. The determination module allows users to determine the cause of an anomaly based on the timing relationship between the anomalies in the first and second types of signals.

[0012] Thirdly, embodiments of this application also provide a battery system, including: a battery assembly, a sensor, an actuator, and a battery detection system as proposed in the second aspect, wherein the battery detection system is electrically connected to the battery assembly, the sensor, and the actuator respectively.

[0013] According to any of the foregoing embodiments of the third aspect of this application, the sensor includes a first type of sensor and a second type of sensor. The first type of sensor includes a photosensitive sensor, and the second type of sensor includes at least one of a temperature sensor, a gas sensor, a pressure sensor, and an electrochemical impedance spectroscopy measuring device. The actuator includes at least one of the following: a warning device, a fuse, a cooling device, and a fire extinguishing device.

[0014] Fourthly, embodiments of this application also provide a vehicle, including at least one of the following: The second aspect proposes a battery testing system; The third aspect proposes any of the following battery systems.

[0015] The battery detection method, detection system, battery system, and vehicle provided in this application have the following beneficial effects: By acquiring the signal values ​​of multiple signals from the battery component, determining whether each signal is abnormal and recording the time of occurrence of the abnormality, and then determining the cause of the abnormality based on the temporal relationship of the abnormality of each signal. Since different abnormal causes have different signal propagation paths and temporal sequences in physical terms, by analyzing the chronological order of the abnormality of each signal, the triggering path of the abnormal event can be determined in reverse. Battery detection is no longer limited to judging whether a single signal exceeds a threshold, but by introducing temporal correlation analysis between multiple signals, each signal is transformed from an isolated threshold trigger point into a chain of abnormal events with temporal correlation. This allows for tracing the cause of the abnormal event based on the chronological order of the signal abnormality, thereby providing a decision-making basis for implementing differentiated safety handling measures for different abnormal causes, which is conducive to improving the accuracy of early warning and the effectiveness of emergency response. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the first process of a battery detection method provided in an embodiment of this application; Figure 2 This is a schematic diagram of the second process of a battery detection method provided in an embodiment of this application; Figure 3This is a schematic diagram of the third process of a battery detection method provided in an embodiment of this application; Figure 4 This is a schematic diagram of the fourth process of a battery detection method provided in an embodiment of this application; Figure 5 This is a schematic diagram of the fifth process of a battery detection method provided in an embodiment of this application; Figure 6 This is a schematic diagram of the sixth process of a battery detection method provided in an embodiment of this application; Figure 7 This is a schematic diagram of the structure of a battery detection system provided in one embodiment of this application; Figure 8 This is a first structural schematic diagram of a battery system provided in an embodiment of this application; Figure 9 This is a schematic diagram of the second structure of a battery system provided in one embodiment of this application; Figure 10 This is a schematic diagram of the third structure of a battery system provided in an embodiment of this application; Figure 11 This is a fourth structural schematic diagram of a battery system provided in one embodiment of this application. Detailed Implementation

[0018] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0019] It should be noted that, in this document, 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..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0020] To ensure the safety of battery systems, related technologies typically employ a Battery Management System (BMS) to monitor and protect the battery's operating status. BMS monitoring strategies primarily rely on threshold judgments of conventional electrochemical parameters such as voltage, current, and temperature. However, these parameters mostly only show significant changes when thermal runaway has reached an irreversible stage, resulting in a limited warning window that fails to meet the needs of early warning and proactive safety protection.

[0021] To address these shortcomings, researchers have recently begun exploring the introduction of various novel sensors into battery packs to capture early signs of thermal runaway.

[0022] (I) Gas Sensor Monitoring Scheme. In the minutes to tens of minutes before the occurrence of battery thermal runaway, the decomposition of electrolyte and side reactions inside the battery will release characteristic gases such as hydrogen, carbon monoxide, carbon dioxide, methane and ethylene. By deploying gas detection devices such as hydrogen sensors and carbon monoxide sensors, the concentration of characteristic gases can be monitored in real time, and an alarm or linkage with the fire protection system can be triggered when the concentration exceeds the threshold, so that early warning can be achieved in the early stage of thermal runaway.

[0023] (II) Pressure Sensor Monitoring Scheme. During battery thermal runaway, the rapid accumulation of internal gas can cause sudden changes in the internal pressure of the battery casing or battery pack casing. By deploying an atmospheric pressure sensor, abnormal pressure changes can be detected in the early stages of thermal runaway. Combined with a temperature sensor, this forms a dual criterion of "temperature + pressure", which helps to improve the reliability and response speed of detection.

[0024] (III) Photosensitive Sensor Monitoring Scheme. The battery pack casing may be damaged by external mechanical impact or puncture, allowing external light to enter the casing. Related technologies utilize photosensitive sensors placed inside the battery pack; when the battery casing leaks light due to a rupture, an alarm signal is triggered by the corresponding photosensitive sensor.

[0025] Although the aforementioned multi-sensor monitoring schemes have each achieved the detection of specific abnormal states, they still have the following shortcomings: (i) The application scenarios of photosensitive sensors are still limited to independent detection of light leakage due to shell damage. They have not yet formed a collaborative judgment framework with temperature sensors, pressure sensors and gas sensors, which makes it impossible for the system to effectively distinguish between two different types of anomalies: "physical damage to the shell" and "internal electrochemical thermal runaway".

[0026] (ii) Most multi-sensor fusion solutions simply superimpose the signals from various sensors, lacking in-depth analysis of the temporal relationships between these signals. In reality, environmental intrusion caused by shell damage and gas / temperature / pressure changes caused by internal thermal runaway differ fundamentally in their timing: the former is initially caused by external impact leading to shell damage, while the latter is initially caused by internal side reactions releasing characteristic gases accompanied by temperature and pressure increases, before potentially triggering the photosensitive signal upon flame formation. Multi-sensor fusion solutions fail to utilize this temporal difference for risk source tracing and identification.

[0027] (iii) Because the cause of abnormal events cannot be identified, the system often outputs homogeneous alarm signals when faced with different types of abnormalities, which makes it difficult to guide subsequent hierarchical response strategies. Unified alarms can easily lead to inappropriate response strategies or even delay the best time to deal with the situation.

[0028] Based on this, embodiments of this application provide a battery detection method, detection system, battery system, and vehicle. By acquiring the signal values ​​of multiple signals from the battery component, the method determines whether each signal is abnormal and records the time of occurrence of the abnormality. Then, it determines the cause of the abnormality based on the temporal relationship of the abnormality occurrences of each signal. Since different abnormal causes have different physical signal propagation paths and temporal sequences, by analyzing the chronological order of the abnormality occurrences of each signal, the triggering path of the abnormal event can be determined in reverse. Battery detection is no longer limited to judging whether a single signal exceeds a threshold; instead, by introducing temporal correlation analysis between multiple signals, each signal is transformed from an isolated threshold trigger point into a chain of abnormal events with temporal correlation. This allows for tracing the cause of the abnormal event based on the chronological order of signal abnormalities, providing a decision-making basis for implementing differentiated safety measures for different abnormal causes, which is beneficial for improving the accuracy of early warning and the effectiveness of emergency response.

[0029] The battery detection method provided in the embodiments of this application will be described by way of example below.

[0030] Figure 1 This is a schematic flowchart of a battery detection method provided in an embodiment of this application, as shown below. Figure 1 As shown, the battery detection method may include the following steps: S110~S130.

[0031] S110: Obtain the signal values ​​of multiple signals from the battery assembly.

[0032] The battery assembly may include individual battery cells, battery modules, or battery packs.

[0033] Multiple signals refer to signals collected by various sensors installed inside or on the surface of the battery assembly. Different types of signals reflect different dimensions of the battery assembly's state information. For example, a photosensor can collect optical signals to characterize the light transmittance of the casing, a temperature sensor can collect temperature signals, a pressure sensor can collect internal gas pressure signals, a gas sensor can collect characteristic gas concentration signals, and an electrochemical impedance spectroscopy (EIS) measurement device can collect impedance signals at different frequencies. Each sensor converts the collected raw physical quantities into signal values ​​that can be read by the processor, such as brightness, temperature, pressure, or concentration values, or digital quantities after analog-to-digital conversion. The processor can communicate with each sensor via wired or wireless means and acquire the signal values ​​of each signal in real time according to a preset sampling frequency. The acquired signal values ​​can be stored in memory for subsequent steps.

[0034] S120. Determine whether the signal value of each signal is abnormal, and when the signal value is determined to be abnormal, record the time when the abnormality occurs; the multiple signals include a first type of signal and a second type of signal. The first type of signal is a signal that characterizes the shell state of the battery module, and the second type of signal is a signal that characterizes the internal state of the battery module.

[0035] In this step, the signal values ​​of each signal acquired in S110 are compared with their respective set thresholds. Different signals correspond to different set thresholds, which can be determined based on the signal reference value of the battery assembly in a healthy state combined with a preset deviation range, or they can be obtained through experimental calibration.

[0036] When the value of a signal exceeds its corresponding set threshold, the signal is deemed abnormal. At this time, the time of the abnormality is recorded. The time of the abnormality can be determined based on the system clock, stored in memory as a timestamp, and associated with the corresponding signal type. Abnormality determinations for different signals are independent, and the time of abnormality for each signal is recorded separately.

[0037] The signals include at least two types of signals. The first type of signal characterizes the state of the battery module casing. Casing state refers to whether the battery module casing maintains structural integrity or has been damaged or deformed. When the casing is damaged, for example, by an external impact causing cracks or breaks, the casing's seal is compromised, allowing external environmental factors (such as light) to enter. Therefore, the structural integrity of the casing can be indirectly characterized by detecting the internal light environment. The first type of signal can be an optical signal collected by a photosensor or other signals that reflect casing deformation or damage.

[0038] The second type of signal characterizes the internal state of the battery module. The internal state refers to the physical or electrochemical state within the battery module, which may include one or more of the following: temperature state, pressure state, gas composition state, or electrochemical impedance spectroscopy state. When an anomaly occurs inside the battery module, such as internal short circuit, electrolyte decomposition, solid electrolyte interphase (SEI) degradation, or lithium dendrite growth, it is usually accompanied by physicochemical phenomena such as increased temperature, increased gas pressure, increased concentration of characteristic gases (such as hydrogen and carbon monoxide), or changes in electrochemical impedance. Therefore, all of the above signals can be used to characterize the internal state. The second type of signal may include at least one of the following: temperature signal collected by a temperature sensor, gas pressure signal collected by a pressure sensor, gas concentration signal collected by a gas sensor, and electrochemical impedance spectroscopy signal collected by an electrochemical impedance spectroscopy measurement device.

[0039] S130. Determine the cause of the anomaly based on the timing relationship between the first type of signal and the second type of signal.

[0040] In S120, the occurrence times of the first type of signal and the second type of signal have been recorded separately. When the first type of signal and the second type of signal each experience an anomaly, the occurrence times of the anomalies may occur in different sequences. For example, the anomaly of the first type of signal may occur before the anomaly of the second type of signal, or the anomaly of the second type of signal may occur before the anomaly of the first type of signal, or the anomalies of the two signals may occur at approximately the same time.

[0041] Since the first type of signal characterizes the casing state of the battery module, and the second type of signal characterizes the internal state of the battery module, corresponding to different physical state dimensions, the temporal relationship between the first and second types of signals can reflect the propagation path and triggering order of abnormal events within the battery module—that is, whether the abnormality develops from the casing to the interior, from the interior to the casing, or both occur simultaneously. By comparing the temporal relationship between the occurrence times of the abnormality in the first type of signal and the abnormality occurrence times in the second type of signal, the specific type of abnormality can be determined.

[0042] In this way, the battery detection method provided by this application is no longer limited to judging whether a single signal exceeds a set threshold. Instead, it traces and distinguishes the triggering source of abnormal events by obtaining the abnormal timing relationship of different types of signals, providing a basis for decision-making for subsequent differentiated handling.

[0043] The battery detection method provided in this application acquires the signal values ​​of multiple signals from the battery module, determines whether each signal is abnormal, and records the time of occurrence of the abnormality. Then, it determines the cause of the abnormality based on the temporal relationship of the abnormality of each signal. Since different abnormal causes have different signal propagation paths and temporal sequences physically, by analyzing the chronological order of the abnormality of each signal, the triggering path of the abnormal event can be determined in reverse. Battery detection is no longer limited to judging whether a single signal exceeds a threshold. Instead, by introducing temporal correlation analysis between multiple signals, each signal is transformed from an isolated threshold trigger point into a chain of abnormal events with temporal correlation. This allows for tracing the cause of the abnormal event based on the chronological order of the signal abnormality, providing a decision-making basis for implementing differentiated safety measures for different abnormal causes, and improving the accuracy of early warning and the effectiveness of emergency response.

[0044] In one embodiment, Figure 1 S130 may include the following steps: S131~S133, such as Figure 2 As shown.

[0045] S131. If the first abnormality of the first type of signal occurs before the second abnormality of the second type of signal, and the time difference between the first abnormality and the second abnormality exceeds a first set duration, or if the signal value of the first type of signal is abnormal and the signal value of the second type of signal is not abnormal, the cause of the abnormality is determined to be shell damage.

[0046] When the first type of signal is abnormal while the second type of signal is not, it indicates that the casing has been damaged, for example, by cracks or breaks caused by external impact. However, the internal state signals of the battery assembly have not yet shown any abnormalities, meaning that the casing damage has not yet led to the deterioration of the internal state. This situation belongs to the very early stage of casing damage.

[0047] When both the first and second types of signals exhibit abnormalities, and the first abnormality of the first type of signal occurs before the second abnormality of the second type of signal, with a time difference exceeding a first set duration, it indicates that the abnormality in the casing state precedes the abnormality in the internal state. In other words, the casing is damaged first, allowing external environmental factors (such as light, moisture, or foreign objects) to enter the casing through the damage. After a period of time, this external intrusion triggers an abnormality in the internal state of the battery module. This time difference exceeding the first set duration indicates a clear temporal boundary between the casing damage and the subsequent internal abnormality; the two do not occur synchronously.

[0048] In both of the above scenarios, the triggering source of the battery malfunction is that the casing fails first. External environmental factors can enter the casing through the damaged area and then cause subsequent internal malfunctions. Therefore, the cause of the malfunction is determined to be casing damage.

[0049] It should be noted that the first set duration can be set according to factors such as the type of battery assembly, the characteristics of the casing material, and the sampling frequency of the sensor, and its value should be sufficient to distinguish between sequential and synchronous relationships in terms of timing. For example, the first set duration can be 1 second, 5 seconds, 10 seconds, 15 seconds, 20 seconds, or 30 seconds, and this application does not limit it in this regard.

[0050] S132. If the second abnormal transmission time of the second type of signal precedes the first abnormal occurrence time of the first type of signal, and the time difference between the first abnormal occurrence time and the second abnormal occurrence time exceeds the first set duration, or if the second type of signal is abnormal but the first type of signal is not abnormal, the cause of the abnormality is determined to be internal thermal runaway.

[0051] When the second type of signal is abnormal while the first type of signal is not abnormal, it indicates that an abnormality has occurred inside the battery module, but the casing has not yet been damaged. This situation corresponds to the deterioration of the internal electrochemical state, such as internal short circuits, electrolyte decomposition, or SEI film rupture caused by overcharging, over-discharging, high temperature, or aging, but the casing structure remains intact.

[0052] When both the first and second types of signals become abnormal, and the second anomaly of the second type of signal occurs before the first anomaly of the first type of signal, with a time difference exceeding a first set duration, it indicates that the anomaly in the internal state of the battery module precedes the anomaly in the state of the casing. In other words, electrochemical degradation first occurs inside the battery module, causing the signal value of the second type of signal to change, such as an increase in temperature or pressure, exceeding the range corresponding to the normal state. After a period of time, the internal pressure or high temperature causes the casing to deform or rupture. This time difference exceeding the first set duration indicates that there is a clear temporal boundary between the internal anomaly and the subsequent casing damage; the two do not occur synchronously.

[0053] In both of the above scenarios, the triggering source of the battery malfunction is the initial internal electrochemical degradation, which then leads to the casing damage. Therefore, the cause of the malfunction is determined to be internal thermal runaway.

[0054] S133. If both the first type of signal and the second type of signal are abnormal, and the time difference between the first abnormality of the first type of signal and the second abnormality of the second type of signal does not exceed the first set time, the cause of the abnormality is determined to be the combined effect of shell damage and thermal runaway.

[0055] When both the first type of signal and the second type of signal are abnormal, and the time difference between the occurrence of the abnormality does not exceed the first set duration, it indicates that the abnormalities of the two types of signals are basically synchronous in time or occur successively in a short period of time, without a clear time boundary.

[0056] This situation typically corresponds to two scenarios: First, a severe external impact (such as a serious collision) simultaneously causes shell damage and an internal short circuit, with shell damage and internal thermal runaway occurring concurrently. Second, an explosive thermal runaway occurs internally, releasing a large amount of heat and pressure instantaneously, rupturing the shell within a short period. In both scenarios, the anomalies of the two types of signals are temporally indistinguishable, therefore the anomalies cannot be attributed to a single shell damage or a single internal thermal runaway. Thus, the cause of the anomalies is determined to be the combined effect of shell damage and thermal runaway.

[0057] The battery detection method provided in this application embodiment can classify the cause of the abnormality as casing damage, internal thermal runaway, or a combination of both based on the abnormal detection results of the first type of signal and the time sequence relationship between the abnormality occurrence time and the abnormality detection results of the second type of signal. This achieves accurate identification and classification of the abnormality trigger source.

[0058] In one embodiment, such as Figure 3 As shown, after determining the cause of the anomaly, the method further includes: S140.

[0059] S140. Generate corresponding early warning control instructions based on the cause of the abnormality. The early warning control instructions are used by the actuator to perform the corresponding early warning operation.

[0060] In this embodiment, the specific type of abnormality cause has been determined in S130, including casing damage, internal thermal runaway, or a combination of both. Different abnormalities correspond to different safety risk levels and physical handling requirements; therefore, it is necessary to generate early warning control commands that match the abnormality cause to control the corresponding actuators to perform corresponding early warning operations. The early warning control commands are control commands in the form of electrical signals, which can be sent to the corresponding actuator drive circuit via a communication bus or hardwired connection to drive the actuator to perform corresponding mechanical or electrical actions. An actuator refers to a hardware device installed in the battery assembly or the system containing the battery assembly, capable of performing physical operations in response to control commands.

[0061] The implementing agency in this application may include the following types: A prompting device is used to output prompts that can be perceived by the user. For example, it can display text information on the dashboard, output light signals through indicator lights, or output voice information through a speaker.

[0062] A fuse or relay is used to disconnect the main circuit of the battery pack to achieve power outage isolation upon receiving a warning control command.

[0063] A cooling device is used to cool the battery assembly upon receiving a warning control command. For example, the battery assembly can be cooled by activating a cooling device (such as a coolant circulation pump).

[0064] Fire extinguishing devices are used to spray extinguishing agents into the battery assembly upon receiving a warning control command. For example, this can be achieved by opening an electrically controlled valve on an extinguishing agent storage container to release extinguishing agents such as perfluorohexanone.

[0065] The aforementioned actuators are each set up independently and can act individually in response to corresponding early warning and control commands, or they can act simultaneously as required by the commands.

[0066] When the cause of the abnormality is shell damage, it indicates that the shell has been damaged but no obvious abnormality has yet appeared inside, or the shell damage precedes the internal abnormality in sequence. In this case, it is necessary to perform a power-off isolation operation first to prevent external intrusion factors from further causing internal short circuits, and output the corresponding shell damage prompt information through the prompt device to inform the user that the shell needs to be inspected.

[0067] When the cause of the abnormality is internal thermal runaway, it indicates that the electrochemical state inside the battery module has deteriorated. At this time, it is necessary to immediately carry out cooling operations through the cooling device to slow down the thermal runaway process, and to carry out fire extinguishing operations through the fire extinguishing device to suppress the spread of the fire. At the same time, the corresponding thermal runaway warning information should be output through the warning device to remind personnel to take timely evacuation.

[0068] When the cause of the anomaly is a combination of factors, it indicates that the shell damage and internal thermal runaway occur simultaneously or nearly simultaneously. In this case, it is necessary to simultaneously perform power-off isolation, cooling and fire extinguishing operations, and output corresponding warning information on the combined risks through the warning device to deal with multiple superimposed safety risks.

[0069] The battery detection method provided in this application, based on the identification of abnormal causes, further generates differentiated early warning control instructions according to the abnormal causes, enabling the actuator to perform corresponding early warning operations for different abnormal causes, which helps to improve the accuracy of early warning and the effectiveness of emergency response.

[0070] Specifically, S140 may include the following steps: S141-S143, such as Figure 4 As shown.

[0071] S141. If the cause of the abnormality is determined to be the combined effect of shell damage and thermal runaway, a first warning control command is generated. The first warning control command is used to control the actuator to perform at least one of the following operations: first prompt operation, power-off isolation operation, cooling operation, fire extinguishing operation, and emergency stop operation.

[0072] The combined effect of shell failure and thermal runaway refers to the occurrence of anomalies in both the first and second types of signals, with the time difference between their occurrence not exceeding a first preset duration. This anomaly indicates that changes in the shell state and internal state occur essentially synchronously or sequentially within a short period, without a clear temporal order. Under this combined effect, shell failure and internal thermal runaway are superimposed, with no single triggering source; both develop synchronously and exacerbate each other.

[0073] In response to the combined effects of casing damage and thermal runaway, a first early warning control command is generated. This command controls the actuators to perform at least one of the following operations: a first alert operation, a power-off isolation operation, a cooling operation, a fire extinguishing operation, and an emergency stop operation. Specifically, the first alert operation outputs the highest-level warning information corresponding to the combined risk, informing the user that the battery module has simultaneously experienced casing damage and internal thermal runaway, requiring immediate emergency evacuation. The power-off isolation operation disconnects the main circuit of the battery module using a fuse or high-voltage relay to prevent external intrusion from further exacerbating the short circuit. The cooling operation cools the battery module by activating the cooling device to reduce the rate of thermal runaway propagation. The fire extinguishing operation releases extinguishing agent by activating the fire extinguishing device to suppress the spread of fire. The emergency stop operation triggers the system-wide emergency stop device to halt the entire system, preventing the fault from spreading to other parts of the system. The above operations can be selectively performed based on the availability of the actuator and the actual scenario. For example, when the system is in an emergency stop state, the power disconnection and isolation operation may not be performed separately, or when the fire extinguishing operation has been initiated, the cooling operation may be performed simultaneously depending on the fire situation. This application does not limit this.

[0074] Compared to the cases where shell failure occurs alone or internal thermal runaway occurs alone, the case of combined action involves shell failure and thermal runaway occurring simultaneously, resulting in the highest safety risk and the most severe physical damage to the system. Therefore, the operation coverage corresponding to the first warning control command is the most comprehensive, including four physical operations: power outage isolation, cooling, fire extinguishing, and emergency stop. At the same time, the highest level of warning information is output through the first prompt operation.

[0075] S142. If the cause of the abnormality is determined to be internal thermal runaway, a second early warning control command is generated. The second early warning control command is used to control the actuator to perform at least one of the following operations: a second prompt operation, a power-off isolation operation, a cooling operation, and a fire extinguishing operation.

[0076] Internal thermal runaway refers to a situation where the anomaly of the second type of signal occurs before the anomaly of the first type of signal, and the time difference exceeds a first set duration, or only the second type of signal is abnormal while the first type of signal is not. This anomaly indicates that electrochemical degradation first occurred within the battery module, leading to an internal anomaly that causes temperature and pressure increases, subsequently causing casing deformation or rupture. In this scenario, internal electrochemical instability is the trigger source, and casing damage (if any) is a subsequent consequence.

[0077] In response to the abnormal cause of internal thermal runaway, a second early warning control command is generated. This command controls the actuator to perform at least one of the following operations: a second alert operation, a power-off isolation operation, a cooling operation, and a fire extinguishing operation. Specifically, the second alert operation outputs a warning message corresponding to the internal thermal runaway through an alert device, informing the user that thermal runaway has occurred inside the battery and immediate evacuation is necessary. The cooling operation activates the cooling device to lower the battery component temperature and slow the spread of thermal runaway. The fire extinguishing operation releases extinguishing agents to suppress the fire. The power-off isolation operation disconnects the main circuit to prevent the fault from escalating. Since internal thermal runaway is the triggering source, and in a thermal runaway state, priority should be given to slowing its spread through cooling and suppressing the fire through fire extinguishing, the operation corresponding to the second early warning control command prioritizes cooling and fire extinguishing; the power-off isolation operation disconnects the energy source to prevent the fault from escalating.

[0078] S143. If the cause of the abnormality is determined to be shell damage, a third early warning control command is generated. The third early warning control command is used to control the actuator to perform at least one of the following operations: third prompt operation and power-off isolation operation.

[0079] Casing damage refers to an anomaly in the first type of signal while the second type of signal remains normal, or the anomaly in the first type of signal occurs before the anomaly in the second type of signal, with a time difference exceeding a first set duration. This anomaly indicates that the casing has been damaged, but no signs of thermal runaway have yet appeared inside the battery assembly, or the casing damage significantly precedes the internal abnormality in timing. Casing damage is a physical structural injury and does not directly cause thermal runaway. However, casing damage compromises the sealing of the battery assembly. Continued use may lead to internal short circuits due to the intrusion of external moisture or foreign objects, thus posing a risk of developing into thermal runaway.

[0080] In response to the abnormal cause of the casing damage, a third early warning control command is generated. This command controls the actuator to perform at least one of the following: a third notification operation and a power-off isolation operation. The third notification operation outputs a notification message indicating casing damage via a notification device, informing the user that the casing is damaged and requires repair. The power-off isolation operation disconnects the main circuit to prevent external intrusion from further causing internal abnormalities. Compared to the first and second early warning control commands, the third early warning control command does not include cooling or fire extinguishing operations because thermal runaway has not yet occurred in the case of casing damage, thus eliminating the need for cooling and fire extinguishing measures.

[0081] It should be noted that the aforementioned first, second, and third early warning control instructions are each expressed as "at least one," meaning that each instruction does not require the control actuator to execute all listed operations simultaneously. In practical applications, depending on the specific configuration of the battery components, the availability of the actuators, and the preset safety policies, some or all operations can be selected for execution. This reduces the risk that the entire instruction will fail to execute due to the failure or absence of a single actuator, thereby improving the system's flexibility and fault tolerance.

[0082] The battery detection method provided in this application can generate differentiated early warning and control commands based on different causes of anomalies. It performs power-off isolation when the casing is damaged, activates fire suppression when thermal runaway occurs, and simultaneously implements multiple measures when multiple risks are present. This allows the actuator to perform early warning operations matching the cause of the anomaly, thereby achieving graded and differentiated safety handling and improving the problem of inadequate response caused by a single alarm mode. Compared to the independent monitoring of related technologies, this application systematically integrates casing damage monitoring and thermal runaway monitoring, combining casing damage detection (photosensitive) and thermal runaway early warning (temperature / pressure / gas), which were originally two independent technical routes, into a unified monitoring framework. This reduces redundant independent alarm subsystems, which helps to reduce system complexity and hardware costs.

[0083] In one embodiment, S131 may include the following steps: If the first abnormality of the first type of signal occurs before the second abnormality of the second type of signal, and the time difference between the first abnormality and the second abnormality exceeds a first set duration, the cause of the abnormality is determined to be damage to the first type of casing. If the signal value of the first type of signal is abnormal and the signal value of the second type of signal is not abnormal, the cause of the abnormality is determined to be damage to the second type of casing.

[0084] S143 may include the following steps: If the cause of the anomaly is determined to be damage to the first type of casing, a third early warning control command is generated; If the cause of the anomaly is determined to be damage to the second type of housing, a fourth early warning control command is generated. The fourth early warning control command is used to control the actuator to perform the fourth prompt operation.

[0085] In this embodiment, the first type of casing damage refers to the occurrence of anomalies in both the first and second types of signals, with the first type of signal anomaly occurring before the second type of signal anomaly in sequence, and the time difference between the two exceeding a first set duration. In this case, it indicates that the casing first breaks down, and after a period of time, external environmental factors enter the casing through the break, triggering an anomaly in the internal electrochemical state. At this point, the casing damage is the trigger source, and the internal state anomaly is the subsequent result; that is, the casing damage has progressed to the stage of causing internal state deterioration, and the risk of thermal runaway has substantially materialized. Therefore, the third early warning control command is used to control the actuator to perform a power-off isolation operation, such as cutting off the main circuit of the battery module through a fuse or high-voltage relay, and outputting a corresponding first type of casing damage warning information through a third prompt operation. This warning information may include content related to replacing the fuse and repairing the casing. "Replacing the fuse" means that when the power-off isolation operation is implemented through a fuse, the fuse needs to be replaced after it blows; if the power-off isolation operation is implemented through a high-voltage relay, then the fuse does not need to be replaced.

[0086] The second type of casing damage refers to a situation where only the first type of signal anomaly occurs, and no second type of signal anomaly is detected after a first set time period. In this case, it indicates that the casing has been damaged, but the internal state has not yet shown abnormal phenomena such as temperature rise, gas pressure increase, characteristic gas release, or changes in electrochemical impedance. At this time, the casing damage is still in a relatively early stage, the internal electrochemical state has not been affected, and thermal runaway has not been triggered. In this case, it is only necessary to output the corresponding second type of casing damage prompt information through the fourth prompt operation, such as prompting the user that the casing is damaged and needs repair, without performing a power-off isolation operation, so as to reduce the impact of power-off operation on the normal operation of the equipment.

[0087] After determining that the cause of the anomaly is the second type of casing damage, the signal values ​​of multiple signals of the battery assembly are continuously acquired, and each signal value is judged to be abnormal. When an anomaly is detected in the signal value of the second type of signal (at least one of the temperature signal, pressure signal, and gas concentration signal), it is determined that the cause of the anomaly has evolved from the second type of casing damage to the first type of casing damage. In response to the change in the cause of the anomaly, the warning control command is switched from the fourth warning control command to the third warning control command, that is, from only outputting prompt information (fourth prompt operation) to performing power-off isolation operation and outputting prompt information (third warning control command).

[0088] The battery detection method provided in this application, when the cause of the abnormality is determined to be the second type of casing damage, is in the early stage of casing damage, thermal runaway has not yet occurred, and the casing damage itself does not yet constitute an emergency danger. Therefore, no power-off isolation operation is performed, and only a fourth prompt operation is output. The prompt operation informs the user that timely maintenance is sufficient, reducing the adverse effects of excessive handling on the normal operation of the equipment. This allows the safety handling strategy to be adapted differently according to the severity of casing damage, further improving the pertinence and rationality of safety handling.

[0089] In one embodiment, the first type of signal includes an optical signal, and the second type of signal includes at least one of a temperature signal, a pressure signal, and a gas concentration signal.

[0090] The optical signal is collected by a photosensitive sensor installed inside the battery assembly to characterize whether the casing is damaged. When the casing is damaged, external light can enter the casing through the damaged area, and the light intensity signal collected by the photosensitive sensor will change.

[0091] Temperature signals can be acquired by temperature sensors installed inside the battery module to characterize its thermal state. Pressure signals can be acquired by pressure sensors installed inside the battery module to characterize the internal pressure of the casing. Gas concentration signals can be acquired by gas sensors installed inside the battery module to characterize the concentration of characteristic gases. Characteristic gases may include thermal runaway-related gases such as hydrogen, carbon monoxide, carbon dioxide, methane, and ethylene. When thermal runaway occurs inside the battery module, it is usually accompanied by increased temperature, increased pressure, and increased concentration of characteristic gases; therefore, the above signals can effectively characterize the internal state of the battery module.

[0092] S130 may include the following steps: S531~S534, such as Figure 5 As shown.

[0093] S531. If the occurrence of an anomaly in the optical signal precedes the occurrence of an anomaly in any one of the temperature signal, pressure signal, and gas concentration signal, and the time difference exceeds a first set duration, the cause of the anomaly is determined to be a first type of shell damage.

[0094] In this step, "the optical signal's anomaly occurs before any of the temperature, pressure, and gas concentration signals" means that the optical signal's anomaly occurs earlier than the anomalies of all the other Type II signals that have already experienced anomalies. In other words, the optical signal is the earliest occurring anomaly among all the signals that have experienced anomalies.

[0095] In the temperature, pressure, and gas concentration signals, the number of signals that have experienced anomalies can be one, two, or three. When all three Type II signals are abnormal, the anomaly in the optical signal occurs before the anomaly in the temperature signal, before the anomaly in the pressure signal, and before the anomaly in the gas concentration signal. When only some Type II signals are abnormal, the anomaly in the optical signal occurs before the anomaly in each of the Type II signals that has already experienced anomalies.

[0096] The physical process corresponding to this determination branch is as follows: the casing is damaged first, and external light enters the casing through the damage. Subsequently, abnormal phenomena such as increased temperature, increased air pressure, or increased gas concentration occur inside the battery assembly. The optical signal shows the earliest abnormality, preceding every second-type signal that has already shown anomalies. This indicates that the casing damage is the trigger source, and the internal anomaly is the result of subsequent development. Therefore, the cause of the anomaly is determined to be the first type of casing damage.

[0097] S532. If the optical signal is abnormal but the temperature signal, pressure signal and gas concentration signal are not abnormal, the cause of the abnormality is determined to be damage to the second type of shell.

[0098] In this step, within a preset time window (greater than the first set duration) after the optical signal anomaly, the temperature, pressure, and gas concentration signals did not show any anomalies. In other words, none of the three internal state signals showed any abnormalities, indicating that although the casing had been damaged, there were no signs of thermal runaway such as increased temperature, increased pressure, or increased concentration of characteristic gases inside the battery assembly. This situation corresponds to an earlier stage of casing damage, where the damage has not yet triggered internal state anomalies; therefore, the cause of the anomaly is determined to be type II casing damage.

[0099] S533. If the time of occurrence of an anomaly in at least one of the temperature signal, pressure signal, and gas concentration signal precedes the time of occurrence of an anomaly in the optical signal, and the time difference exceeds a first set duration, the cause of the anomaly is determined to be internal thermal runaway.

[0100] In this step, "the occurrence of an anomaly in at least one of the temperature, pressure, and gas concentration signals precedes the occurrence of an anomaly in the optical signal" means that at least one of the temperature, pressure, and gas concentration signals is abnormal, and the occurrence of this anomaly occurs earlier than the occurrence of the anomaly in the optical signal. When all three Type II signals are abnormal, the judgment condition of this step is met as long as the occurrence of the anomaly in any one of the temperature, pressure, and gas concentration signals is earlier than the occurrence of the anomaly in the optical signal.

[0101] It should be noted that when the anomalies of multiple Type II signals all occur before the anomalies of the optical signal, the earliest Type II signal with an anomaly is used as the benchmark for time-series comparison with the optical signal. This is because the earliest anomaly signal best represents the start time of internal thermal runaway and can most accurately reflect the origin of time from when the anomaly began to occur internally.

[0102] The physical process corresponding to this determination branch is as follows: Electrochemical degradation first occurs inside the battery module, leading to internal anomalies that cause temperature increases, pressure increases, or the release of characteristic gases. Subsequently, the internal pressure or high temperature causes the casing to deform or rupture, allowing external light to enter the casing through the damaged area. If the anomaly of an internal state signal (i.e., the second type of signal) occurs before the anomaly of the optical signal, it indicates that internal thermal runaway occurred before the casing rupture in time, thus determining the cause of the anomaly as internal thermal runaway.

[0103] S534. If the time difference between the occurrence time of an anomaly in at least one of the temperature signal, pressure signal, and gas concentration signal and the occurrence time of an anomaly in the optical signal does not exceed a first set time, the cause of the anomaly is determined to be the combined effect of shell damage and thermal runaway.

[0104] In this step, "the time difference between the time of occurrence of an anomaly in at least one of the temperature signal, pressure signal, and gas concentration signal and the time of occurrence of an anomaly in the optical signal does not exceed the first set duration" means that at least one of the temperature signal, pressure signal, and gas concentration signal has an anomaly, and the absolute value of the time difference between the time of occurrence of the anomaly in the temperature signal, pressure signal, and gas concentration signal and the time of occurrence of the anomaly in the optical signal does not exceed the first set duration.

[0105] The occurrence of the second type of signal anomaly can occur before or after the occurrence of the optical signal anomaly, as long as the absolute value of the time difference between the two does not exceed the first preset duration, the determination condition of this step is met. When multiple second type signals meet this condition, the determination condition of this step is satisfied, and there is no need to further select a specific signal as a reference, because the fact that the time difference does not exceed the first preset duration itself indicates that the optical signal and the internal state signal are basically synchronous in time or occur successively within a short period of time, and there is no time difference between the two. The shell state change and the internal state change actually occur within the same time window, and it is impossible to distinguish the causal order.

[0106] It should be noted that the difference between "before the occurrence of the optical signal anomaly" in this step and S533 lies in the magnitude of the time difference. When the occurrence of the second type of signal anomaly precedes the occurrence of the optical signal anomaly, but the absolute value of the time difference does not exceed the first preset duration, it indicates that although the second type of signal is slightly earlier than the optical signal anomaly, the difference is within the preset time window and is insufficient to establish a sequential relationship. In this case, the anomalies of the two types of signals are still considered to be basically synchronous in time, and therefore should be classified as a combined effect rather than internal thermal runaway.

[0107] From the perspective of priority determination, the prerequisite for S534 is that the occurrence time of any second-type signal anomaly does not precede the occurrence time of the optical signal anomaly and the time difference exceeds the first preset duration (i.e., condition S533 is not met), but the time difference between the occurrence time of at least one second-type signal anomaly and the occurrence time of the optical signal anomaly does not exceed the first preset duration. In other words, when condition S533 is met, the cause of the anomaly is determined to be internal thermal runaway, and the determination in S534 is no longer initiated.

[0108] It should be noted that if the time difference between multiple signals (temperature, pressure, and gas concentration) and the optical signal does not exceed the first preset duration, the determination condition of S534 is already met, and there is no need to further select any signal as the reference. This is because the time difference not exceeding the first preset duration itself indicates that the optical signal and the internal state signal are basically synchronized in time or occur successively within a short period of time. Any one of the multiple signals meeting this condition is sufficient to show that the anomalies of the two types of signals are indistinguishable in time.

[0109] The physical process corresponding to this judgment branch is as follows: a violent external impact causes the shell to break and the internal short circuit simultaneously, or the internal explosive thermal runaway bursts the shell instantly. The abnormality of the two types of signals cannot be distinguished in time, so the cause of the abnormality is determined to be the combined effect of shell breakage and thermal runaway.

[0110] The battery electrical measurement method provided in this application can classify the cause of anomalies into first-type shell damage, second-type shell damage, internal thermal runaway, or a combination of shell damage and thermal runaway based on the temporal relationship between the optical signal and the temperature signal, pressure signal, and gas concentration signal when the anomaly occurs, thereby achieving accurate identification of the anomaly trigger source.

[0111] In one embodiment, the second type of signal includes an electrochemical impedance spectroscopy (EIS) signal. EIS is a technique for characterizing the internal electrochemical state of a battery cell by applying a small AC perturbation signal to the battery assembly and measuring its impedance response. The EIS signal can be acquired using an EIS measurement device installed in the battery assembly, which includes an AC signal generation unit and an impedance response measurement unit. The AC signal generation unit applies AC perturbation signals (e.g., voltage or current perturbations) of different frequencies to the battery assembly, and the impedance response measurement unit measures the impedance response of the cell to these AC perturbation signals, thereby obtaining impedance values ​​at different frequencies.

[0112] "Acquiring the signal value of the second type of signal" may include the following steps: acquiring the impedance value of the electrochemical impedance spectroscopy signal at at least one target frequency.

[0113] Determining whether the signal value of the second type of signal is abnormal may include the following steps: If the impedance value at the target frequency exceeds the corresponding set impedance threshold, it is determined that the electrochemical impedance spectroscopy signal is abnormal.

[0114] In this embodiment, the target frequency is a characteristic frequency that is sensitive to changes in the internal state of the battery module. In practical applications, at least one target frequency can be selected based on the battery type and failure mode, thus eliminating the need for full-band frequency sweep measurement. Selecting at least one target frequency for point-frequency monitoring can reduce measurement time and system overhead while remaining sensitive to changes in critical internal states, facilitating deployment in real-time application scenarios such as automotive applications.

[0115] As an example, the target frequency can be a specific frequency point in the high-frequency range (such as above 1kHz) used to monitor changes in the ohmic resistance of the battery cell, which are related to the electrolyte conductivity and electrode electronic conductivity.

[0116] As an example, the target frequency can also be a specific frequency point in the mid-frequency range (such as 1 Hz to 1 kHz) used to monitor changes in SEI film impedance and charge transfer impedance, which are related to the electrode interface state.

[0117] As an example, the target frequency can also be a specific frequency point in the low-frequency region (such as 0.1Hz to 1Hz) to monitor Warburg impedance. Warburg impedance can reflect changes in lithium-ion diffusion behavior, thereby identifying the degradation of the internal electrochemical state of the battery module.

[0118] There can be one or more target frequencies. When there are multiple target frequencies, the impedance value of each target frequency is compared with its corresponding set impedance threshold. It is understandable that, since the second type of signal is an electrochemical impedance spectroscopy signal, which characterizes the internal electrochemical state of the battery module, when the impedance value of any target frequency exceeds the corresponding set impedance threshold, it is determined that the electrochemical impedance spectroscopy signal is abnormal, i.e., the internal state of the battery module is abnormal.

[0119] The impedance threshold can be determined based on the initial impedance value of the battery module in a healthy state combined with a preset deviation range, or it can be obtained through experimental calibration. For example, the impedance threshold can be set based on the initial impedance value of the battery module at the time of manufacture multiplied by a coefficient greater than 1 (e.g., 1.2 times, 1.5 times, or 2 times); it can also be calibrated based on impedance change data obtained from aging tests or thermal runaway tests on multiple battery modules of the same model. This application does not limit this.

[0120] In this embodiment, the second type of signal is an electrochemical impedance spectroscopy (EIS) signal, which can replace any one or more of the temperature, pressure, and gas concentration signals, or can be used together with one or more of the aforementioned signals as the second type of signal. When the second type of signal simultaneously includes the EIS signal and at least one of the temperature, pressure, and gas concentration signals, the anomaly determination method for the EIS signal is performed independently from the anomaly determination methods for the temperature, pressure, and gas concentration signals. The processor performs threshold comparisons on each signal and records the time of anomaly occurrence. If at least one of the EIS, temperature, pressure, and gas concentration signals is abnormal, the second type of signal is determined to be abnormal. When recording the time of anomaly occurrence, the time of anomaly occurrence for the second type of signal is based on the earliest occurrence of the anomaly. This is because the earliest abnormal internal state signal best represents the starting time of the change in the internal state of the battery module and can most accurately reflect the origin of time from which the anomaly begins to occur internally.

[0121] The battery detection method provided in this application uses electrochemical impedance spectroscopy (EIS) signals to detect anomalies. Compared to schemes that rely on macroscopic physical signals such as temperature, pressure, or gas concentration, EIS signals can capture anomalies at an earlier stage when the electrochemical state inside the battery module changes, thus advancing the anomaly detection window and providing more time for subsequent safety measures. Furthermore, a time-series comparison can be made between the EIS signals and optical signals. When the optical signal anomalies before the EIS signal, it indicates that the casing is damaged first, and external intrusion triggers a change in the electrochemical state. When the EIS signal anomalies before the optical signal, it indicates that the internal electrochemical state deteriorates first, subsequently leading to casing rupture. The time-series relationship between the two signals can still effectively distinguish between casing damage and internal thermal runaway—two different anomaly triggers.

[0122] For example, such as Figure 6 As shown, the battery detection method may include the following steps: S601~S613.

[0123] S601, Begin.

[0124] S601, Signal Acquisition: Acquires signals from four sensors: photosensitive, temperature, pressure, and gas.

[0125] In this step, a photosensitive sensor, a temperature sensor, an atmospheric pressure sensor, and a gas sensor are installed inside the battery pack casing to collect photosensitive signals, temperature signals, pressure signals, and gas concentration signals inside the casing in real time.

[0126] S602, Threshold Comparison: Each signal VS sets the threshold.

[0127] This step compares the photosensitive signal, temperature signal, pressure signal, and gas concentration signal with their respective set thresholds to determine whether each signal is abnormal.

[0128] S603. Determine if there is any abnormal signal: Any signal exceeds the standard.

[0129] When any of the following signals—photosensitive signal, temperature signal, pressure signal, and gas concentration signal—is determined to be abnormal, record the moment when the abnormality occurs.

[0130] S604, Timing Record: Record the moment when the signal is abnormal, and continue to wait for other signal abnormalities to record all abnormal moments.

[0131] In this step, the trigger source type (i.e. the cause of the abnormality) of the battery is determined based on the temporal relationship between the time when the photosensitive signal becomes abnormal and the time when the temperature signal, pressure signal, or gas concentration signal becomes abnormal.

[0132] The preset threshold Δt is between 1 second and 10 seconds, preferably 5 seconds; S605, Scenario 1: The photosensitive element precedes the temperature / pressure / air pressure, and the time difference is greater than Δt.

[0133] When the abnormal occurrence of the photosensitive signal precedes the abnormal occurrence of any of the temperature, pressure, and gas concentration signals, and the time difference exceeds the first set threshold Δt, the trigger source is determined to be shell damage.

[0134] The first set threshold Δt ranges from 1 second to 10 seconds, preferably 5 seconds.

[0135] S606, Level 1 Warning.

[0136] When the abnormal triggering source is determined to be casing damage, a first-level warning signal is output to control the prompting device to output a prompt message indicating casing damage and to perform a power-off isolation operation.

[0137] S607, Scenario 2: Temperature / pressure / air pressure precedes photosensitivity, and the time difference is greater than Δt.

[0138] When the abnormal occurrence of any of the temperature, pressure, or gas concentration signals occurs before the abnormal occurrence of the photosensitive signal, and the time difference exceeds the first set threshold Δt, the trigger source is determined to be internal thermal runaway.

[0139] S608, Level 2 Warning.

[0140] When the abnormal triggering source is determined to be thermal runaway, a second-level warning signal is output to control the prompting device to output thermal runaway and emergency avoidance prompts, and to execute fire suppression activation and cooling operations.

[0141] S609, Scenario 3: Temperature / pressure / air pressure / photosensitivity occur simultaneously, or the time difference is ≤△t.

[0142] When the difference between the time of the abnormal occurrence of the photosensitive signal and the time of the abnormal occurrence of any one of the temperature signal, pressure signal, or gas concentration signal does not exceed the first set threshold Δt, the trigger source is determined to be a composite risk.

[0143] S610, Level 3 Warning.

[0144] When the abnormal triggering source is determined to be a composite risk, a third-level warning signal is output to control the prompting device to output composite risk and emergency avoidance prompts, and at the same time execute power-off isolation operation, fire suppression activation operation and full system emergency stop operation.

[0145] S611, End.

[0146] Based on the battery testing method provided in the above embodiments, this application also provides specific implementation methods of the battery testing system. Please refer to the following embodiments.

[0147] First see Figure 7 The battery detection system 700 provided in this application embodiment may include: an acquisition module 701, a judgment module 702, and a determination module 703.

[0148] The acquisition module 701 is used to acquire the signal values ​​of multiple signals of the battery assembly; The judgment module 702 is used to judge whether the signal value of each signal is abnormal, and when the signal value of the signal is determined to be abnormal, the time when the abnormality occurs is recorded; the multiple signals include a first type of signal and a second type of signal, the first type of signal is a signal that characterizes the shell state of the battery module, and the second type of signal is a signal that characterizes the internal state of the battery module; In module 703, the user determines the cause of the anomaly based on the timing relationship between the anomalies of the first type of signal and the second type of signal.

[0149] The battery detection system provided in this application acquires the signal values ​​of multiple signals from the battery module, determines whether each signal is abnormal, and records the time of occurrence of the abnormality. Then, it determines the cause of the abnormality based on the temporal relationship of the abnormality of each signal. Since different abnormal causes have different signal propagation paths and temporal sequences physically, by analyzing the chronological order of the abnormality times of each signal, the triggering path of the abnormal event can be determined in reverse. Battery detection is no longer limited to judging whether a single signal exceeds a threshold; instead, by introducing temporal correlation analysis between multiple signals, each signal is transformed from an isolated threshold trigger point into a chain of abnormal events with temporal correlation. This allows for tracing the cause of the abnormal event based on the chronological order of the signal abnormalities, providing a decision-making basis for implementing differentiated safety measures for different abnormal causes, and improving the accuracy of early warning and the effectiveness of emergency response.

[0150] In one embodiment, the determining module may include: The first determining unit is configured to determine that the cause of the abnormality is shell damage when the first abnormality of the first type of signal occurs before the second abnormality of the second type of signal and the time difference between the first abnormality and the second abnormality exceeds a first set duration, or when the signal value of the first type of signal is abnormal and the signal value of the second type of signal is not abnormal. The second determining unit is used to determine the cause of the abnormality as internal thermal runaway when the second abnormal transmission time of the second type of signal is earlier than the first abnormal occurrence time of the first type of signal and the time difference between the first abnormal occurrence time and the second abnormal occurrence time exceeds a first set duration, or when the second type of signal is abnormal and the first type of signal is not abnormal. The third determining unit is used to determine the cause of the abnormality as a combination of shell damage and thermal runaway when both the first type of signal and the second type of signal are abnormal and the time difference between the first abnormality time of the first type of signal and the second abnormality time of the second type of signal does not exceed the first set time.

[0151] In one embodiment, after determining the cause of the anomaly, the apparatus may further include: a generation module, which may further include: The first generation unit is used to generate a first warning control command when the cause of the abnormality is determined to be the combined effect of shell damage and thermal runaway. The first warning control command is used to control the actuator to perform at least one of the following operations: first prompt operation, power-off isolation operation, cooling operation, fire extinguishing operation, and emergency stop operation. The second generation unit is used to generate a second early warning control command when the cause of the abnormality is determined to be internal thermal runaway. The second early warning control command is used to control the actuator to perform at least one of the following operations: a second prompt operation, a power-off isolation operation, a cooling operation, and a fire extinguishing operation. The third generation unit is used to generate a third early warning control command when the cause of the abnormality is determined to be shell damage. The third early warning control command is used to control the actuator to perform at least one of the following operations: a third prompt operation and a power-off isolation operation.

[0152] In one embodiment, the first determining unit may further include: The first determining subunit is configured to determine that the cause of the abnormality is damage to the first type of housing when the first abnormality of the first type of signal occurs before the second abnormality of the second type of signal, and the time difference between the first abnormality and the second abnormality exceeds a first set duration. The second determining subunit is used to determine that the cause of the abnormality is damage to the second type of housing when the signal value of the first type of signal is abnormal and the signal value of the second type of signal is not abnormal.

[0153] The third generation unit may also include: The first generation subunit is used to generate a third early warning control command when the cause of the anomaly is determined to be damage to the first type of shell. The second generation subunit is used to generate a fourth early warning control command when the cause of the abnormality is determined to be damage to the second type of shell. The fourth early warning control command is used to control the actuator to perform the fourth prompt operation.

[0154] In one embodiment, the first type of signal includes an optical signal, and the second type of signal includes at least one of a temperature signal, a pressure signal, and a gas concentration signal; the determining module may include: The fourth determining unit is used to determine that the cause of the abnormality is a type of shell damage when the time of occurrence of the optical signal abnormality precedes the time of occurrence of any one of the temperature signal, pressure signal, and gas concentration signal abnormality, and the time difference exceeds a first set time. The fifth determining unit is used to determine that the cause of the abnormality is a second type of shell damage when the optical signal is abnormal but the temperature signal, pressure signal and gas concentration signal are not abnormal. The sixth determining unit is used to determine that the cause of the abnormality is internal thermal runaway when at least one of the temperature signal, pressure signal and gas concentration signal occurs before the occurrence of the abnormality of the optical signal and the time difference exceeds a first set time. The seventh determining unit is used to determine that the cause of the abnormality is the combined effect of shell damage and thermal runaway, provided that the time difference between the time of abnormality occurrence of at least one of the temperature signal, pressure signal, and gas concentration signal and the time of abnormality occurrence of the optical signal does not exceed a first set time.

[0155] In one embodiment, the second type of signal includes an electrochemical impedance spectroscopy signal; the acquisition module is specifically used to: acquire the impedance value of the electrochemical impedance spectroscopy signal at at least one target frequency; the judgment module is specifically used to: determine that the electrochemical impedance spectroscopy signal is abnormal when the impedance value at the target frequency exceeds the corresponding set impedance threshold.

[0156] Based on the aforementioned real-time method, this application also provides a battery system. For example... Figure 8 As shown, the battery system 800 includes: a battery assembly 804, a sensor 801, an actuator 802, and a battery detection system 700 provided in the above embodiment. The battery detection system 700 is electrically connected to the battery assembly 804, the sensor 801, and the actuator 802.

[0157] The battery assembly 804 is an energy storage device, including at least one battery cell. Exemplarily, the battery assembly 804 may include a single battery cell, a battery module, or a battery pack. A battery module includes multiple battery cells connected in series and / or parallel, and a battery pack includes multiple battery modules. The battery assembly 804 is subject to thermal runaway risk during use, requiring real-time monitoring of its safety status.

[0158] Sensor 801 is disposed inside or on the surface of battery assembly 804 and is used to collect signal values ​​of multiple signals from battery assembly 804. Sensor 801 may include a sensor for collecting a first type of signal (i.e., a first-type sensor) and a sensor for collecting a second type of signal (i.e., a second-type sensor). Sensor 801 transmits the collected signal values ​​to battery detection system 700 via electrical connection.

[0159] The first type of sensor may include a photosensitive sensor disposed inside the housing of the battery assembly to collect optical signals characterizing the state of the housing. Multiple photosensitive sensors are arranged in an array at the bottom of the battery assembly, dividing the internal space of the housing into multiple detection areas, each with a grid size ranging from 10cm × 10cm to 30cm × 30cm. As an example, the photosensitive sensor may include a photodiode or a photoresistor.

[0160] The second type of sensor may include at least one of temperature sensors, pressure sensors, gas sensors, and electrochemical impedance spectroscopy measurement devices.

[0161] Temperature sensors are used to acquire temperature signals that characterize the internal thermal state of a battery assembly. As an example, a temperature sensor includes a thermistor with a temperature measurement range of -40°C to 125°C and an accuracy of ±1°C.

[0162] Pressure sensors are used to acquire pressure signals that characterize the internal air pressure state of a housing. As an example, an atmospheric pressure sensor may include a micro-electro-mechanical systems (MEMS) piezoresistive pressure sensor with a range of 50 kPa to 200 kPa and an accuracy of ±0.5%FS.

[0163] Gas sensors are used to acquire gas concentration signals that characterize the concentration of a specific gas. As an example, gas sensors include an electrochemical hydrogen sensor for detecting hydrogen (H2) concentration and an electrochemical carbon monoxide sensor for detecting carbon monoxide (CO) concentration, with a detection limit not exceeding 10 ppm.

[0164] Electrochemical impedance spectroscopy (EIS) measurement devices are used to acquire EIS signals that characterize the internal electrochemical state of a battery cell.

[0165] For example, such as Figure 9As shown, in this battery system 800, sensor 801 includes a photosensor 8011, a temperature sensor 8012, a pressure sensor 8013, and a gas sensor 8014. The photosensor 8011 is disposed inside the housing of the battery assembly 804 and is used to collect optical signals inside the battery assembly 804, which characterize the housing state of the battery assembly 804. The temperature sensor 8012 is disposed inside the battery assembly 804 and is used to collect temperature signals inside the battery assembly 804. The pressure sensor 8013 is disposed inside the battery assembly 804 and is used to collect gas pressure signals inside the battery assembly 804. The gas sensor 8014 is disposed inside the battery assembly 804 and is used to collect concentration signals of characteristic gases (e.g., hydrogen, carbon monoxide, and other gases associated with thermal runaway) inside the battery assembly 804. The temperature signal, pressure signal, and gas concentration signal together constitute a second type of signal used to characterize the internal state of the battery assembly 804.

[0166] For example, such as Figure 9 As shown, in the battery system 800, the battery detection system 700 includes a signal acquisition module 8031 ​​(i.e., acquisition module), a timing judgment module 8032 (i.e., judgment module + determination module), a warning output module 8033, and an actuator control module 8034. The input terminal of the signal acquisition module 8031 ​​is electrically connected to the output terminals of each sensor in the sensor 801, and is used to acquire the output signals of each sensor in real time at a preset frequency, convert the analog signals into digital signals, and transmit them to the timing judgment module 8032. The input terminal of the timing judgment module 8032 is electrically connected to the output terminal of the signal acquisition module 8031, and is used to determine whether the signal value of each signal is abnormal, record the corresponding time of abnormality when an abnormality is determined, and determine the cause of the abnormality based on the timing relationship between the abnormalities of the first type of signal and the second type of signal.

[0167] The timing judgment module 8032 may include a threshold comparison unit 80321, a timing recording unit 80322, and a timing analysis unit 80323.

[0168] The threshold comparison unit 80321 is used to compare the signal value of each signal with its corresponding set threshold to determine whether each signal is abnormal. For example, when the photosensitive signal is greater than the photosensitive threshold, the photosensitive abnormality flag is set to "1"; when the temperature signal is greater than the temperature threshold, the temperature abnormality flag is set to "1"; when the pressure signal is greater than the pressure threshold, the pressure abnormality flag is set to "1"; and when the gas concentration signal is greater than the gas concentration threshold, the gas abnormality flag is set to "1".

[0169] The timing recording unit 80322 is used to record the time when the threshold comparison unit 80321 determines that the signal is abnormal. For example, the timing recording unit 80322 is used to record the time when the signal is abnormal when any abnormal flag position "1" is detected.

[0170] The timing analysis unit 80323 is used to determine the cause of the anomaly based on the timing relationship between the occurrence of anomalies in the first type of signal and the second type of signal. Specifically, the timing analysis unit 80323 is configured to execute the anomaly cause determination logic described in the above embodiments, for example, based on the timing relationship between the occurrence time of anomalies in the optical signal and at least one of the temperature signal, pressure signal, and gas concentration signal, the cause of the anomaly is determined to be shell damage (including first type shell damage and second type shell damage), internal thermal runaway, or a combination of shell damage and thermal runaway.

[0171] The input terminal of the early warning output module 8033 is electrically connected to the output terminal of the timing judgment module 8032, and is used to generate corresponding early warning control commands based on the abnormal cause determined by the timing judgment module 8032. Specifically, when the abnormal cause is determined to be shell damage, a first-level early warning control command is output, which is associated with a power-off isolation operation; when the abnormal cause is determined to be internal thermal runaway, a second-level early warning control command is output, which has a higher urgency than the first-level command, and is associated with a fire suppression activation operation and a cooling operation; when the abnormal cause is determined to be a complex risk, a third-level early warning control command is output, which has a higher urgency than the second-level command, and is associated with the simultaneous execution of a power-off isolation operation, a fire suppression activation operation, and a system-wide emergency stop operation.

[0172] The input terminal of the actuator control module 8034 is electrically connected to the output terminal of the early warning output module 8033, and is used to send the early warning control command generated by the early warning output module 8033 to the actuator 802 to drive the actuator 802 to perform the corresponding early warning operation.

[0173] An actuator 802 is disposed within the battery assembly 804 or in the equipment (e.g., a vehicle) to which the battery system 800 is applied, and is used to perform corresponding warning operations in response to warning control commands generated by the battery detection system 700. The actuator 802 may include at least one of a prompting device 8024, a fuse 8021 (or a high-voltage relay), a cooling device 8022, and a fire extinguishing device 8023. The prompting device 8024 is used to output prompt information perceptible to the user, such as instrument panel text display, indicator lights, and voice announcements. The fuse 8021 is connected in series in the main circuit of the battery assembly and is used to disconnect the main circuit to achieve power isolation upon receiving a control command. The cooling device 8022 (e.g., a coolant circulation pump and cooling pipes) is used to cool the battery assembly upon receiving a control command. The fire extinguishing device 8023 (e.g., a fire extinguishing agent storage container and an electrically controlled valve) is used to spray a fire extinguishing agent (such as perfluorohexanone) into the battery assembly upon receiving a control command.

[0174] The input terminals of the battery detection system 700 are connected via a wiring harness or communication bus (e.g., CAN bus or I...). 2 The C-bus is electrically connected to the output terminal of sensor 801. The signal value collected by sensor 801 is transmitted to battery detection system 700 through this connection for anomaly detection.

[0175] The output of the battery detection system 700 is electrically connected to the control terminal of the actuator 802 via a wiring harness or communication bus (e.g., CAN bus). The warning control commands generated by the battery detection system 700 are transmitted to the actuator 802 through this connection to drive the actuator to perform the corresponding warning operation.

[0176] The battery detection system 700 is connected to the positive and negative terminals of the battery module 804 through a voltage detection line to collect the voltage signal of the battery module 804. At the same time, it is connected to the control terminal of the high-voltage relay or fuse of the battery module 804 through a control line to perform power-off isolation operation.

[0177] When the battery system 800 is operating, the sensor 801 collects signal values ​​of multiple signals from the battery module 804 in real time, including first-type signals (such as optical signals) and second-type signals (such as temperature signals, pressure signals, gas concentration signals, and electrochemical impedance spectroscopy signals), and sends each signal value to the battery detection system 700. The battery detection system 700 determines whether the signal value of each signal is abnormal, and records the time of occurrence of the abnormality when an abnormality is determined. Then, it determines the cause of the abnormality based on the temporal relationship between the first-type and second-type signals, and generates a corresponding early warning control command based on the cause of the abnormality. This command controls the actuator 802 to perform the corresponding early warning operation after receiving the early warning control command, such as one or more of the following: prompt operation, power-off isolation operation, cooling operation, fire extinguishing operation, and emergency stop operation.

[0178] The battery system 800 provided in this application embodiment can collect multiple signals of the battery component 804 in real time through the sensor 801. The battery detection system 700 performs time-series correlation analysis on the signals to determine the cause of the abnormality, and the actuator 802 executes differentiated early warning operations, thereby realizing comprehensive monitoring and graded handling of the safety status of the battery component 804.

[0179] For example, such as Figure 10 As shown, the battery system 800 includes multiple battery modules 804 arranged in an array. Each battery module 804 may include individual battery cells or battery modules. A photosensitive sensor 8011 is disposed below the battery module 804, in the space between the bottom surface of the battery module 804 and the housing. Secondary sensors (including a temperature sensor 8012, a pressure sensor 8013, and a gas sensor 8014) are disposed above the battery module, in the space between the top surface of the battery module 804 and the top cover of the housing. By placing the photosensitive sensor 8011 close to the bottom of the battery module 804, it can capture changes in the light signal of external light entering the housing immediately when the bottom of the housing is damaged, improving the sensitivity and timeliness of housing damage detection. Similarly, by placing the temperature sensor 8012, pressure sensor 8013, and gas sensor 8014 close to the top of the battery module 804, it can also capture changes in the light signal of external light entering the housing immediately when the bottom of the housing is damaged, further improving the sensitivity and timeliness of housing damage detection.

[0180] For example, such as Figure 11 As shown, the battery detection system 700 can be integrated inside the battery system 800, for example, in a spare space within the battery assembly 804 housing, or integrated onto the circuit board of the battery management system. Alternatively, the battery detection system 700 can also be located outside the battery system, for example, as a stand-alone microcontroller, or in the controller of the device (e.g., a vehicle) to which the battery system 800 is applied. When the battery detection system 700 is integrated inside the battery management system, the signal acquisition module 8031, timing judgment module 8032, warning output module 8033, and actuator control module 8034 can be implemented by the processor and memory of the battery management system. When the processor executes the computer program stored in the memory, the functions of the above modules are realized.

[0181] Based on the above embodiments, this application also provides a vehicle, which includes at least one of the following: any battery detection system and any battery system provided in this application have the same beneficial effects, and will not be repeated here to avoid repetition.

[0182] The vehicles may include pure electric vehicles and hybrid vehicles.

[0183] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0184] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A battery testing method, characterized in that, include: Acquire the signal values ​​of multiple signals from the battery assembly; Each signal is individually assessed to determine whether its signal value is abnormal, and when an abnormal signal value is determined to be abnormal, the time of the abnormality is recorded; the plurality of signals include a first type of signal and a second type of signal, wherein the first type of signal is a signal characterizing the casing state of the battery assembly, and the second type of signal is a signal characterizing the internal state of the battery assembly; The cause of the anomaly is determined based on the timing relationship between the first type of signal and the second type of signal.

2. The method according to claim 1, characterized in that, The step of determining the cause of the anomaly based on the timing relationship between the anomalies in the first type of signal and the second type of signal includes: If the first abnormality of the first type of signal occurs before the second abnormality of the second type of signal, and the time difference between the first abnormality and the second abnormality exceeds a first set duration, or if the signal value of the first type of signal is abnormal and the signal value of the second type of signal is not abnormal, the cause of the abnormality is determined to be shell damage. If the second abnormal transmission time of the second type of signal precedes the first abnormal occurrence time of the first type of signal, and the time difference between the first abnormal occurrence time and the second abnormal occurrence time exceeds the first set duration, or if the second type of signal is abnormal and the first type of signal is not abnormal, the cause of the abnormality is determined to be internal thermal runaway. If both the first type of signal and the second type of signal are abnormal, and the time difference between the first abnormality time of the first type of signal and the second abnormality time of the second type of signal does not exceed the first set time, the cause of the abnormality is determined to be the combined effect of shell damage and thermal runaway.

3. The method according to claim 2, characterized in that, After determining the cause of the anomaly, the method further includes: If the cause of the anomaly is determined to be the combined effect of shell damage and thermal runaway, a first warning control command is generated. The first warning control command is used to control the actuator to perform at least one of the following operations: first prompt operation, power-off isolation operation, cooling operation, fire extinguishing operation, and emergency stop operation. If the cause of the anomaly is determined to be internal thermal runaway, a second early warning control command is generated. The second early warning control command is used to control the actuator to perform at least one of the following operations: a second prompt operation, a power-off isolation operation, a cooling operation, and a fire extinguishing operation. If the cause of the abnormality is determined to be shell damage, a third early warning control command is generated. The third early warning control command is used to control the actuator to perform at least one of the following operations: a third prompt operation and a power-off isolation operation.

4. The method according to claim 3, characterized in that, The step of determining the cause of the anomaly as shell damage when the first anomaly of the first type of signal occurs before the second anomaly of the second type of signal, and the time difference between the first anomaly and the second anomaly exceeds a first preset duration, or when the signal value of the first type of signal is abnormal but the signal value of the second type of signal is not abnormal, includes: If the first abnormality of the first type of signal occurs before the second abnormality of the second type of signal, and the time difference between the first abnormality and the second abnormality exceeds a first set duration, the cause of the abnormality is determined to be first type of shell damage. If the signal value of the first type of signal is abnormal and the signal value of the second type of signal is not abnormal, the cause of the abnormality is determined to be damage to the second type of casing. If the cause of the anomaly is determined to be shell damage, a third early warning control command is generated, including: If the cause of the anomaly is determined to be damage to the first type of casing, the third early warning control command is generated. If the cause of the anomaly is determined to be damage to the second type of housing, a fourth early warning control command is generated, which is used to control the actuator to perform a fourth prompt operation.

5. The method according to any one of claims 1-4, characterized in that, The first type of signal includes optical signals, and the second type of signal includes at least one of temperature signals, pressure signals, and gas concentration signals; The step of determining the cause of the anomaly based on the timing relationship between the anomalies in the first type of signal and the second type of signal includes: If the occurrence of the optical signal anomaly precedes the occurrence of any one of the temperature signal, pressure signal, and gas concentration signal anomalies, and the time difference exceeds a first set duration, the cause of the anomaly is determined to be a type of shell damage. If the optical signal is abnormal but the temperature signal, pressure signal, and gas concentration signal are not abnormal, the cause of the abnormality is determined to be damage to the second type of housing. If the anomaly in at least one of the temperature signal, the pressure signal, and the gas concentration signal occurs before the anomaly in the optical signal, and the time difference exceeds the first set duration, the cause of the anomaly is determined to be internal thermal runaway. If the time difference between the time of an anomaly in at least one of the temperature signal, the pressure signal, and the gas concentration signal and the time of an anomaly in the optical signal does not exceed the first set duration, the cause of the anomaly is determined to be a combination of shell damage and thermal runaway.

6. The method according to any one of claims 1-4, characterized in that, The second type of signal includes electrochemical impedance spectroscopy signals; Obtaining the signal value of the second type of signal includes: Obtain the impedance value of the electrochemical impedance spectroscopy signal at at least one target frequency; Determining whether the signal value of the second type of signal is abnormal includes: If the impedance value at the target frequency exceeds the corresponding set impedance threshold, it is determined that the electrochemical impedance spectroscopy signal is abnormal.

7. A battery testing system, characterized in that, include: The acquisition module is used to acquire the signal values ​​of multiple signals from the battery assembly; The judgment module is used to judge whether the signal value of each signal is abnormal, and when the signal value of the signal is determined to be abnormal, record the time when the abnormality occurs; the plurality of signals include a first type of signal and a second type of signal, wherein the first type of signal is a signal characterizing the shell state of the battery assembly, and the second type of signal is a signal characterizing the internal state of the battery assembly; The determination module allows the user to determine the cause of the anomaly based on the timing relationship between the anomalies in the first type of signal and the second type of signal.

8. A battery system, characterized in that, include: The battery assembly, sensor, actuator, and battery detection system as described in claim 7, wherein the battery detection system is electrically connected to the battery assembly, the sensor, and the actuator, respectively.

9. The battery system according to claim 8, characterized in that, The sensor includes a first type of sensor and a second type of sensor. The first type of sensor includes a photosensitive sensor, and the second type of sensor includes at least one of a temperature sensor, a gas sensor, a pressure sensor, and an electrochemical impedance spectroscopy measuring device. The actuator includes at least one of a prompting device, a fuse, a cooling device, and a fire extinguishing device.

10. A vehicle, characterized in that, Includes at least one of the following: The battery testing system as described in claim 7; The battery system as described in claim 8 or 9.

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