Battery cell self-discharge state detection method, electronic equipment and storage medium

Abstract

The embodiment of the invention provides a method for detecting the self-discharging state of a battery cell, electronic equipment and a storage medium, and is applied to the electronic equipment, and the method comprises the following steps: when any to-be-detected battery cell is switched from a discharging state to a standing state, detecting the self-discharging state of the battery cell; acquiring a first static voltage of the to-be-detected cell at the first time point, a second static voltage of the to-be-detected cell at the second time point and an interval duration between the first time point and the second time point; based on the first static voltage, the second static voltage and the interval duration, determining a target voltage drop speed of the to-be-detected cell; obtaining a first residual electric quantity of the to-be-detected battery cell when the discharge state is cut off, and determining a corresponding first voltage drop speed threshold value based on the first residual electric quantity; and comparing the target voltage drop speed with a first voltage drop speed threshold value, and determining the self-discharge state of the to-be-detected cell. According to the invention, the detection of the self-discharge state of the battery cell corresponds to different voltage drop speed judgment standards at different residual electric quantities, so that the accuracy of the detection of the self-discharge state of the battery cell is improved.

Description

Technical Field

[0001] This application relates to the technical field of electronic devices, and particularly to a method for detecting the self-discharge state of a battery cell, an electronic device, and a storage medium. Background Art

[0002] The consistency of the battery system voltage is an important factor restricting the charge and discharge capacity of the battery pack or energy storage system. When the battery has abnormal self-discharge, the remaining power of the abnormal battery cell slowly decreases over time, resulting in an inevitable deterioration of the system consistency. Even if the battery system is balanced and charged, the deterioration can only be suppressed for a short time. Therefore, it is particularly important to identify the battery cells with abnormal self-discharge in the battery system.

[0003] By detecting the voltage drop rate of the battery cells after the battery system is emptied and left standing for a period of time, but the remaining power of the battery cells in the battery system is not completely consistent during the detection, and the voltage drop rate of the same battery cell with abnormal self-discharge is also different under different remaining powers. In the related art, using the same threshold as the self-discharge abnormality judgment standard for the battery system is prone to misjudgment and affects the performance of the battery system. Summary of the Invention

[0004] Embodiments of this application provide a method for detecting the self-discharge state of a battery cell, an electronic device, and a storage medium. The detection of the self-discharge state of the battery cell corresponds to different voltage drop rate judgment criteria for different remaining powers, thereby improving the accuracy of detecting the self-discharge state of the battery cell.

[0005] In a first aspect, embodiments of this application provide a method for detecting the self-discharge state of a battery cell, which is applied to an electronic device. The electronic device includes a battery system, and the battery system includes a plurality of battery cells to be detected. The method includes:

[0006] When any one of the battery cells to be detected switches from the discharging state to the static state, obtain the first static voltage of the battery cell to be detected at a first time point, the second static voltage at a second time point, and the time interval between the first time point and the second time point;

[0007] Based on the first static voltage, the second static voltage, and the time interval, determine the target voltage drop rate of the battery cell to be detected;

[0008] Obtain the first remaining power of the battery cell to be detected when the discharging state ends, and determine the corresponding first voltage drop rate threshold based on the first remaining power;

[0009] Compare the target voltage drop rate with the first voltage drop rate threshold to determine the self-discharge state of the battery cell to be detected.

[0010] Optionally, in some embodiments of the present application, before obtaining the first static voltage of the cell to be detected at the first time point, the second static voltage at the second time point, and the time interval between the first time point and the second time point when any of the cells to be detected switches from the discharging state to the static state, the method further includes:

[0011] Obtaining a first abnormal cell of the battery system;

[0012] At a preset temperature, fully charge and discharge the first abnormal cell, and adjust the first abnormal cell to a first preset remaining power;

[0013] When the first abnormal cell is at the first preset remaining power, obtain the first preset voltage of the first abnormal cell at the first time point, the second preset voltage at the second time point, and the time interval between the first time point and the second time point;

[0014] Based on the first preset voltage, the second preset voltage, and the time interval, determine a first preset voltage drop speed threshold corresponding to the first abnormal cell at the first preset remaining power;

[0015] Form a first preset voltage drop speed threshold set with different preset voltage drop speed thresholds corresponding to the first abnormal cell at different remaining powers.

[0016] Optionally, in some embodiments of the present application, the determining the corresponding first voltage drop speed threshold based on the first remaining power includes:

[0017] Based on the first remaining power of the cell to be detected, determine the remaining power of the first abnormal cell;

[0018] Based on the remaining power of the first abnormal cell, obtain the first target voltage drop speed threshold from the first preset voltage drop speed threshold set.

[0019] Optionally, in some embodiments of the present application, the comparing the target voltage drop speed with the first voltage drop speed threshold to determine the self-discharge state of the cell to be detected includes:

[0020] If the target voltage drop speed is greater than or equal to the first voltage drop speed threshold, determine that the cell to be detected is a target abnormal cell;

[0021] If the target voltage drop speed is less than the first voltage drop speed threshold, determine that the self-discharge of the cell to be detected is normal.

[0022] Optionally, in some embodiments of the present application, after determining the target voltage drop rate of the battery cell to be detected based on the first static voltage, the second static voltage, and the interval duration, the method further includes:

[0023] Obtaining the second remaining power and the target life state of the battery cell to be detected when the discharge state ends;

[0024] Determining a corresponding second voltage drop rate threshold based on the second remaining power and the target life state;

[0025] Comparing the target voltage drop rate with the second voltage drop rate threshold to determine the self-discharge state of the battery cell to be detected.

[0026] Optionally, in some embodiments of the present application, before obtaining the first static voltage of the battery cell to be detected at the first time point, the second static voltage at the second time point, and the interval duration between the first time point and the second time point when any of the battery cells to be detected switches from the discharge state to the stationary state, the method further includes:

[0027] Obtaining a set of abnormal battery cells of the battery system, where the set of abnormal battery cells includes abnormal battery cells in different life states;

[0028] Performing full charge and full discharge on the second abnormal battery cell at a preset temperature and adjusting the second abnormal battery cell to a second preset remaining power, where the second abnormal battery cell is an abnormal battery cell in any life state in the set of abnormal battery cells;

[0029] When the second abnormal battery cell is at the second preset remaining power, obtaining the third preset voltage of the second abnormal battery cell at the first time point, the fourth preset voltage at the second time point, and the interval duration between the first time point and the second time point;

[0030] Determining a corresponding second preset voltage drop rate threshold of the second abnormal battery cell at the second preset remaining power based on the third preset voltage, the fourth preset voltage, and the interval duration;

[0031] Forming a second preset voltage drop rate threshold set with different preset voltage drop rate thresholds corresponding to abnormal battery cells in different life states in the set of abnormal battery cells at different remaining powers.

[0032] Optionally, in some embodiments of the present application, the determining a corresponding second voltage drop rate threshold based on the second remaining power and the target life state includes:

[0033] Determining the second abnormal battery cell from the set of abnormal battery cells based on the target life state;

[0034] Determine the remaining power of the second abnormal battery cell based on the second remaining power of the battery cell to be detected;

[0035] Based on the remaining power of the second battery cell, obtain the second target voltage drop speed threshold from the second preset voltage drop speed set.

[0036] Optionally, in some embodiments of the present application, the comparing the target voltage drop speed with the second voltage drop speed threshold to determine the self-discharge state of the battery cell to be detected includes:

[0037] If the target voltage drop speed is greater than or equal to the second voltage drop speed threshold, determine that the battery cell to be detected is the target abnormal battery cell;

[0038] If the target voltage drop speed is less than the second voltage drop speed threshold, determine that the self-discharge of the battery cell to be detected is normal.

[0039] Optionally, in some embodiments of the present application, the method further includes:

[0040] If the battery cell to be detected is the target abnormal battery cell, replace the battery cell to be detected.

[0041] In a second aspect, an embodiment of the present application provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the steps of the detection method for the self-discharge state of any battery cell as described above are implemented.

[0042] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, and the storage medium stores a computer program. When the computer program is executed by a processor, the steps of the detection method for the self-discharge state of any battery cell as described above are implemented.

[0043] An embodiment of the present application provides a method for detecting the self-discharge state of a battery cell, an electronic device, and a storage medium. When any battery cell to be detected switches from a discharging state to a static state, obtain the first static voltage of the battery cell to be detected at a first time point, the second static voltage at a second time point, and the time interval between the first time point and the second time point; based on the first static voltage, the second static voltage, and the time interval, determine the target voltage drop speed of the battery cell to be detected; obtain the first remaining power of the battery cell to be detected when the discharging state ends, and determine the corresponding first voltage drop speed threshold based on the first remaining power; compare the target voltage drop speed with the first voltage drop speed threshold to determine the self-discharge state of the battery cell to be detected. In the present application, the detection of the self-discharge state of the battery cell has different voltage drop speed judgment criteria corresponding to different remaining powers, thereby improving the accuracy of the detection of the self-discharge state of the battery cell. Description of the Drawings

[0044] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0045] Figure 1 is the first flowchart of the method for detecting the self-discharge state of the battery cell provided by the embodiment of the present application;

[0046] Figure 2 is the second flowchart of the method for detecting the self-discharge state of the battery cell provided by the embodiment of the present application;

[0047] Figure 3 is the structural schematic diagram of the electronic device provided by the embodiment of the present application. Detailed implementation manners

[0048] To make the features and advantages of the present application more obvious and understandable, the following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0049] When the following description involves the accompanying drawings, unless otherwise indicated, the same numbers in different accompanying drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present application. On the contrary, they are only examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0050] Hereinafter, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as implying or suggesting relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0051] It should be noted that abnormal self-discharge refers to the phenomenon that the remaining power of the battery cell naturally decreases due to internal electrochemical reactions without charge and discharge operations. Under normal circumstances, the battery cell will also have a certain degree of self-discharge, but when the self-discharge speed exceeds the normal range, abnormal self-discharge occurs. In the case of abnormal self-discharge, the remaining power of the battery cell will slowly decrease over time, resulting in the deterioration of the battery system consistency. Even with equalization and charging, the deterioration can only be suppressed for a short time.

[0052] Battery system consistency refers to the uniformity of each cell in a battery pack in terms of voltage, remaining charge, charge and discharge performance, etc. In a battery system, cells are usually connected in series or parallel, so the state of each cell will affect the performance of the entire system. When a cell has abnormal self-discharge, its remaining charge will gradually decrease, resulting in the voltage of this cell being inconsistent with that of other normal cells. For example, the voltage of a normal cell may be 3.7V, while the voltage of a cell with abnormal self-discharge may be only 3.5V. During the charge and discharge process, the inconsistent voltage and remaining charge of the cells will lead to a decline in the overall performance of the system. For example, during charging, a cell with abnormal self-discharge may not be able to be fully charged synchronously with other cells, resulting in an extended charging time or incomplete charging; during discharging, a cell with abnormal self-discharge may deplete its charge prematurely, causing the entire system to stop working prematurely and affecting the effective capacity of the system.

[0053] Balanced charge replenishment is a technology that replenishes the charge of cells through an external circuit, aiming to keep the SOC of each cell consistent, thereby improving the overall performance of the system. However, balanced charge replenishment can only alleviate the problems caused by abnormal self-discharge in a short period. The reasons are as follows: The self-discharge speed remains unchanged: Even if the SOC of the abnormal cell is temporarily increased through balanced charge replenishment, the internal self-discharge problem of the cell is not solved, and the SOC will still continue to decline; Dynamic inconsistency: In actual operation, the SOC and voltage of the cells will change continuously. The voltage of the cell with abnormal self-discharge drops faster, and even after balanced charge replenishment, the difference between it and other cells will gradually increase; System performance is limited: Even if the SOC of the cells is temporarily made consistent through balanced charge replenishment, due to the damaged performance of the cell with abnormal self-discharge, the charge and discharge efficiency and capacity of the entire system will still be limited.

[0054] That is to say, after discharging and leaving the battery system static for a period of time, the voltage drop speed of the cells is detected for judgment. However, the remaining charges of the cells in the battery system are not completely consistent during detection, and the voltage drop speed of the same cell with abnormal self-discharge after standing at different remaining charges is also different. In the related technology, using the same threshold as the judgment standard for abnormal self-discharge in the battery system is prone to misjudgment, affecting the performance of the battery system.

[0055] To improve the accuracy of detecting the self-discharge state of cells, the embodiments of the present application provide a method for detecting the self-discharge state of cells, which will be described in detail below. It should be noted that the description order of the following embodiments does not limit the priority order of the embodiments.

[0056] Please refer to Figure 1 , Figure 1It is the first process schematic diagram of the detection method for the self-discharge state of the battery cell provided by the embodiment of the present application. The detection method for the self-discharge state of the battery cell is applied to an electronic device, and the electronic device includes a battery system. The battery system includes multiple battery cells to be detected. The specific process of the detection method for the self-discharge state of the battery cell can be as follows:

[0057] 101. When any battery cell to be detected switches from the discharging state to the static state, obtain the first static voltage of the battery cell to be detected at the first time point, the second static voltage at the second time point, and the interval duration between the first time point and the second time point.

[0058] In this embodiment, the battery system is the core component of the electronic device, mainly used for storing and releasing electrical energy. The battery system is composed of multiple battery cells, which are connected in series or parallel to meet the requirements of the energy storage system for voltage and capacity. The battery system may include components such as battery cells, a battery management system, electrical connectors, and a housing. The types of battery systems may include lithium-ion battery systems, sodium-ion battery systems, etc. During the process of detecting the self-discharge of the battery cells in the battery system, each battery cell in the battery system can be used as a battery cell to be detected, that is, the battery system includes multiple battery cells to be detected.

[0059] It should be noted that in the battery system, the battery cells usually have a charging state, a discharging state, and a static state. The detection condition in this embodiment is that the state of the battery cell to be detected switches from the discharging state to the static state. Among them, the discharging state means that the battery cell is providing electrical energy for the device, and at this time, the voltage of the battery cell will gradually decrease with discharging; the static state means that the battery cell stops discharging and is in a static state, and at this time, the voltage change of the battery cell is mainly caused by self-discharge. When the battery cell switches from the discharging state to the static state, its voltage will gradually stabilize, but it will still slowly decrease due to self-discharge. Therefore, measuring the voltage drop speed of the battery cell is the key to judging the self-discharge state.

[0060] Optionally, when any battery cell to be detected is in the static state, obtain the first static voltage, the second static voltage, and the interval duration. Among them, the first static voltage U1 is the voltage measured at the first time point after the battery cell is static; the second static voltage U2 is the voltage measured at the second time point after the battery cell is static; the interval duration T is the time interval from the first time point to the second time point. Among them, after obtaining the first static voltage U1, shut down the battery system, disconnect the battery cell voltage acquisition harness through the maintenance window to prevent the battery management system from taking power from the battery cell to be detected, and at the same time modify the temperature control strategy to control the temperature of the battery cell at a preset temperature such as 25°C; after standing for the interval duration T, reconnect the battery cell voltage acquisition harness of the battery cell to be detected to obtain the second static voltage U2.

[0061] Optionally, in some embodiments, before the step of "when any cell to be detected switches from the discharging state to the static state, obtaining the first static voltage of the cell to be detected at the first time point, the second static voltage at the second time point, and the interval duration between the first time point and the second time point", the method may further include:

[0062] Obtaining a first abnormal cell of the battery system; performing a full charge and discharge on the first abnormal cell at a preset temperature, and adjusting the first abnormal cell to a first preset remaining power; when the first abnormal cell is at the first preset remaining power, obtaining the first preset voltage of the first abnormal cell at the first time point, the second preset voltage at the second time point, and the interval duration between the first time point and the second time point; determining a first preset voltage drop speed threshold corresponding to the first abnormal cell at the first preset remaining power based on the first preset voltage, the second preset voltage, and the interval duration; and forming a first preset voltage drop speed threshold set by different preset voltage drop speed thresholds corresponding to the first abnormal cell at different remaining powers.

[0063] Specifically, in a battery system, there may be some cells with abnormal self-discharge. These cells are usually identified through preliminary detection (such as too fast voltage drop speed). For example, during on-site operation, by monitoring the cell voltage, it is found that the voltage drop speed of some cells is significantly higher than that of other cells, and these cells are marked as the first abnormal cells.

[0064] It can be understood that in order to ensure the accuracy of the test, it is necessary to test the abnormal cells under unified conditions. The specific steps are as follows: preset temperature: select a stable temperature environment, such as 25 °C. Temperature has a significant impact on the self-discharge speed of the cell, so it is necessary to control the test at a constant temperature; full charge and discharge: perform a complete charge and discharge cycle on the abnormal cell to eliminate the possible voltage memory effect inside the cell and restore its consistency; adjust to the first preset remaining power: adjust the remaining power of the cell to a preset value, such as 40%. This preset value is the basic remaining power point for subsequent tests.

[0065] After adjusting the remaining power of the first abnormal battery cell to the first preset remaining power, obtain the first preset voltage at the first time point, the second preset voltage at the second time point, and the time interval between the first time point and the second time point. Based on this, calculate the difference between the second preset voltage and the first preset voltage, and calculate the ratio of this difference to the time interval to obtain the first preset voltage drop speed threshold corresponding to the first abnormal battery cell at the first preset remaining power. It should be noted that in order to comprehensively evaluate the self-discharge characteristics of the battery cell, the above steps need to be repeated at multiple different remaining power points to obtain the voltage drop speed thresholds at different remaining powers, and combine them to form the first preset voltage drop speed threshold set for subsequent judgment of the self-discharge state of other battery cells. Thus, systematically obtain the voltage drop speed thresholds of abnormal battery cells at different remaining powers, and construct a complete threshold set to directly obtain the threshold through experimental data, avoiding the limitations of a single threshold; applicable to battery cells in different remaining power states, improving the accuracy of judgment; through the complete threshold set, the self-discharge characteristics of the battery cell can be comprehensively evaluated.

[0066] For example, when the remaining power is 30%, repeat the above steps, and the calculated voltage drop speed threshold is 0.45 mV / h; when the remaining power is 20%, the calculated voltage drop speed threshold is 0.50 mV / h; when the remaining power is 10%, the calculated voltage drop speed threshold is 0.60 mV / h. Therefore, the first preset voltage drop speed threshold set is (K 10％ = 0.60 mV / h; K 20％ = 0.50 mV / h; K 30％ = 0.45 mV / h).

[0067] 102. Based on the first static voltage, the second static voltage, and the time interval, determine the target voltage drop speed of the battery cell to be detected.

[0068] In some embodiments, the target voltage drop speed is determined by measuring the voltage change of the battery cell in the static state. Among them, the first static voltage U1 is the voltage measured at the first time point after the battery cell switches from the discharge state to the static state, serving as the starting voltage value for calculating the voltage drop speed; the second static voltage U2 is the voltage measured at the second time point after the battery cell has been static for a period of time, serving as the ending voltage value for calculating the voltage drop speed; the time interval T is the time interval from measuring the first static voltage to measuring the second static voltage, usually in hours, and is used to calculate the voltage change speed per unit time. The target voltage drop speed of the battery cell to be detected is the voltage reduction speed per unit time of the battery cell in the static state, which is a key parameter for judging the self-discharge state of the battery cell. The calculation formula is K = (U1 - U2) / T, where the unit of K is mV / h (millivolt per hour).

[0069] For example, the first static voltage U1 of the battery cell to be detected is 3.6V, the second static voltage U2 is 3.58V, and the time interval between the first static voltage and the second static voltage is 24 hours. Then the target voltage drop rate K is 0.83mV / h.

[0070] 103. Obtain the first remaining charge of the battery cell to be detected when the discharge state ends, and determine the corresponding first voltage drop rate threshold based on the first remaining charge.

[0071] In some embodiments, during on-site charge and discharge operations, a complete charge and discharge cycle of the battery system is performed until the battery cell discharge ends. At the end of the discharge, record the dynamic voltage U3 of the battery cell, which is the voltage of the battery cell at the end of discharge. Through experiments or known battery cell characteristic curves, establish the relationship between voltage and remaining charge. For example, the voltage U3 of the battery cell at the end of discharge may correspond to a specific SOC value. Through program analysis, match U3 with the remaining charge to determine the first remaining charge of the battery cell at the end of discharge.

[0072] Optionally, in some embodiments, the step of "determining the corresponding first voltage drop rate threshold based on the first remaining charge" may specifically include:

[0073] Based on the first remaining charge of the battery cell to be detected, determine the remaining charge of the first abnormal battery cell; based on the remaining charge of the first abnormal battery cell, obtain the first target voltage drop rate threshold from the first preset voltage drop rate threshold set.

[0074] Specifically, according to the first voltage drop rate threshold set obtained by pre-testing, find the first target voltage drop rate threshold corresponding to the first remaining charge. For example, if the remaining charge of the battery cell to be monitored is 30%, then the remaining charge of the first abnormal battery cell is 30%, and the first target voltage drop rate threshold corresponding to the first abnormal battery cell when the remaining charge is 30% is found.

[0075] For example, at the end of the discharge, record the dynamic voltage U3 of the battery cell as 3.00V, and determine that the remaining charge corresponding to U3 = 3.00V is 30% according to the known battery cell characteristic curve. Assume that the pre-tested voltage drop rate threshold set is: when the remaining charge is 10%, the voltage drop rate threshold is 0.60mV / h; when the remaining charge is 20%, the voltage drop rate threshold is 0.50mV / h; when the remaining charge is 30%, the voltage drop rate threshold is 0.45mV / h; when the remaining charge is 40%, the voltage drop rate threshold is 0.417mV / h. Then when the first remaining charge of the battery cell to be detected is 30%, the remaining charge of the corresponding first abnormal battery cell is 30%, and the first target voltage drop rate threshold is 0.45mV / h.

[0076] 104. Compare the target voltage drop rate with the first voltage drop rate threshold to determine the self-discharge state of the battery cell to be detected.

[0077] The target voltage drop rate K is calculated by measuring the voltage change of the battery cell in the static state. The specific formula is: K = (U1 - U2) / T, where: U1 is the static voltage of the battery cell after standing for 3 hours; U2 is the static voltage of the battery cell after standing for another period of time (such as 24 hours); T is the time interval from measuring U1 to measuring U2.

[0078] The first voltage drop rate threshold is obtained through experimental tests in advance and is used to judge whether the self-discharge of the battery cell is abnormal at a specific remaining charge. The threshold is determined according to the remaining charge state of the battery cell. For example, when the remaining charge is 30%, the first voltage drop rate threshold is 0.45 mV / h; when the remaining charge is 40%, the first voltage drop rate threshold is 0.417 mV / h.

[0079] Optionally, in some embodiments, the step of "comparing the target voltage drop rate with the first voltage drop rate threshold to determine the self-discharge state of the battery cell to be detected" may specifically include:

[0080] If the target voltage drop rate is greater than or equal to the first voltage drop rate threshold, determine that the battery cell to be detected is the target abnormal battery cell; if the target voltage drop rate is less than the first voltage drop rate threshold, determine that the self-discharge of the battery cell to be detected is normal.

[0081] Specifically, compare the calculated target voltage drop rate K with the first voltage drop rate threshold at the corresponding remaining charge. If K is greater than or equal to the first voltage drop rate threshold, it indicates that the self-discharge rate of the battery cell is too fast and there is self-discharge abnormality, and the battery cell to be detected is determined to be the target abnormal battery cell; if K is less than the first voltage drop rate threshold, it indicates that the self-discharge rate of the battery cell is within the normal range, and the battery cell to be detected is determined to have normal self-discharge.

[0082] Optionally, in some embodiments, if the battery cell to be detected is the target abnormal battery cell, replace the battery cell to be detected.

[0083] Optionally, in some embodiments, the replaced abnormal battery cell needs to be sent back to the laboratory for further testing to verify whether its self-discharge state is consistent with the on-site judgment. The laboratory test steps are as follows: Single battery cell test: Test the abnormal battery cell separately, including full charge and full discharge operations, and adjust it to different SOC states. Measure the voltage change of the battery cell in the static state and calculate its actual voltage drop rate. Verify the self-discharge state: Compare the voltage drop rate obtained from the laboratory test with the voltage drop rate judged on-site to verify whether the self-discharge state of the battery cell is consistent with the expectation.

[0084] If laboratory tests find that there are deviations in on-site judgments, it is necessary to revise the test standards to optimize the judgment threshold. The optimization steps are as follows: Analyze the deviation: Compare the laboratory test results with the on-site judgment results and analyze the reasons for the deviation. For example, the deviation may be due to differences in environmental conditions (such as temperature, humidity) or changes in the aging characteristics of the battery cells; Revise the threshold: Adjust the corresponding remaining voltage drop speed threshold according to the laboratory test results. For example, if the laboratory test finds that the actual voltage drop speed is higher than the on-site threshold, it may be necessary to increase the threshold; Update the standard: Update the revised threshold into the test standard to form a new judgment standard, ensuring that the new standard is more in line with the actual on-site situation and improving the accuracy and reliability of the judgment.

[0085] As can be seen from the above, in this embodiment, when any battery cell to be detected switches from the discharging state to the static state, the first static voltage of the battery cell to be detected at the first time point, the second static voltage at the second time point, and the time interval between the first time point and the second time point are obtained; based on the first static voltage, the second static voltage, and the time interval, the target voltage drop speed of the battery cell to be detected is determined; the first remaining power of the battery cell to be detected at the end of the discharging state is obtained, and the corresponding first voltage drop speed threshold is determined based on the first remaining power; the target voltage drop speed is compared with the first voltage drop speed threshold to determine the self-discharge state of the battery cell to be detected. In this embodiment, the detection of the self-discharge state of the battery cell has different voltage drop speed judgment criteria corresponding to different remaining powers, avoiding the misjudgment situation caused by using a certain threshold as the self-discharge abnormality judgment standard in the related art, thereby improving the accuracy of the self-discharge state detection of the battery cell.

[0086] Since the life states of the individual battery cells in the battery system are not exactly the same, if the self-discharge abnormality is judged only based on the threshold corresponding to the same life state, it is easy to cause misjudgment. Therefore, to further improve the accuracy of the self-discharge state detection of the battery cell, please refer to Figure 2 , Figure 2 is the second process schematic diagram of the method for detecting the self-discharge state of the battery cell provided by the embodiment of the present application. The specific process of the method for detecting the self-discharge state of the battery cell provided by this embodiment can be as follows:

[0087] 201. When any battery cell to be detected switches from the discharging state to the static state, obtain the first static voltage of the battery cell to be detected at the first time point, the second static voltage at the second time point, and the time interval between the first time point and the second time point.

[0088] In this embodiment, for the specific description of obtaining data in step 201, please refer to the description of step 101 in the above embodiment, and details are not described here.

[0089] Optionally, in some embodiments, before the step of "when any cell to be detected switches from the discharging state to the static state, obtaining the first static voltage of the cell to be detected at the first time point, the second static voltage at the second time point, and the interval duration between the first time point and the second time point", it may further include:

[0090] Obtain the set of abnormal cells of the battery system, where the set of abnormal cells includes abnormal cells in different life states; at a preset temperature, fully charge and discharge the second abnormal cell and adjust the second abnormal cell to a second preset remaining power, where the second abnormal cell is any abnormal cell in any life state in the set of abnormal cells; when the second abnormal cell is at the second preset remaining power, obtain the third preset voltage of the second abnormal cell at the first time point, the fourth preset voltage at the second time point, and the interval duration between the first time point and the second time point; based on the third preset voltage, the fourth preset voltage, and the interval duration, determine the second preset voltage drop speed threshold corresponding to the second abnormal cell at the second preset remaining power; form a second preset voltage drop speed threshold set with different preset voltage drop speed thresholds corresponding to abnormal cells in different life states in the set of abnormal cells at different remaining powers.

[0091] Specifically, obtain the set of abnormal cells. The set of abnormal cells refers to the set of cells determined to have self-discharge abnormalities in the battery system. The cells in the set of abnormal cells may be in different life states. For example: new cells (close to full life state); mid-life cells; cells close to the end of life. These cells are determined to be abnormal through on-site operation feedback and are collected for further testing.

[0092] Select the second abnormal cell from the set of abnormal cells and perform a full charge and discharge operation on it. The purpose is to: eliminate the voltage memory effect inside the cell; ensure that the cell is in a consistent initial state.

[0093] Adjust the second preset remaining power of the second abnormal cell to a preset value (such as 30% or 40%), and obtain the third preset voltage U3, the fourth preset voltage U4, and the interval duration T. Among them, when the second abnormal cell is at the second preset remaining power, measure the third preset voltage U3: the voltage measured at the first time point; the fourth preset voltage U4: the voltage measured at the second time point; the interval duration T: the time interval from the first time point to the second time point. Calculate the second preset voltage drop speed threshold K = (U3 - U4) / T corresponding to the second abnormal cell at the second preset remaining power based on the third preset voltage U3, the fourth preset voltage U4, and the interval duration T.

[0094] Repeat the above steps for each battery cell (in different life states) in the abnormal battery cell set to obtain different voltage drop rate thresholds at different remaining battery levels. Combine the different voltage drop rate thresholds to form a second preset voltage drop rate threshold set for subsequent determination of the self-discharge state of other battery cells. Thus, systematically obtain the voltage drop rate thresholds of abnormal battery cells at different remaining battery levels and construct a complete threshold set to directly obtain the thresholds through experimental data, avoiding the limitations of a single threshold; applicable to battery cells in different remaining battery states, improving the accuracy of judgment; through the complete threshold set, comprehensively evaluate the self-discharge characteristics of the battery cells.

[0095] For example, select a second abnormal battery cell from the abnormal battery cell set. Assume that the life state of the second abnormal battery cell is in the middle stage. Perform a complete charge and discharge cycle on the second abnormal battery cell to ensure its state is consistent. Adjust the remaining battery level of the second abnormal battery cell to a second preset remaining battery level, such as 30%; after standing for 3 hours, measure the third preset voltage U3 of the second abnormal battery cell, such as 3.50V; continue to stand for 24 hours and then measure the fourth preset voltage U4 of the second abnormal battery cell, such as 3.48V; calculate the second preset voltage drop rate threshold K = 0.83mV / h. Therefore, the second preset voltage drop rate threshold of the second abnormal battery cell at a second preset remaining battery level of 30% is 0.83mV / h.

[0096] Repeat the above steps for other battery cells (in different life states) in the abnormal battery cell set to obtain their voltage drop rate thresholds at different remaining battery levels. For example: the remaining battery level of a new battery cell is 30%, and the calculated second preset voltage drop rate threshold is 0.70mV / h; the remaining battery level of a battery cell with a middle-stage life is 30%, and the calculated second preset voltage drop rate threshold is; the remaining battery level of a battery cell with an end-stage life is 30%, and the calculated second preset voltage drop rate threshold is 0.95mV / h. Combine them to form a second preset voltage drop rate threshold set: (new battery cell: 0.70mV / h; middle-stage life battery cell: 0.83mV / h; end-stage life battery cell: 0.95mV / h).

[0097] 202. Determine the target voltage drop rate of the battery cell to be detected based on the first static voltage, the second static voltage, and the interval duration.

[0098] For the specific description of step 202 for calculating the target voltage drop rate, please refer to the description of step 102 in the above embodiment and will not be elaborated here.

[0099] 203. Obtain the second remaining battery level and the target life state of the battery cell to be detected when the discharge state ends.

[0100] In a battery system, the remaining power and life status of each battery cell are key parameters for judging its self-discharge status. Specifically, when the battery cell discharges to cut-off, by measuring its dynamic voltage U3 and combining the matching relationship between voltage and remaining power, the remaining power of the battery cell is determined. Among them, the battery cell to be detected corresponds to the second remaining power.

[0101] The life status of the battery cell can be determined by its usage time, charge-discharge cycle times or other aging indicators. For example, the battery cell may be in a new state, mid-life or near the end of its life. Among them, the battery cell to be detected corresponds to the target life status.

[0102] 204. Determine the corresponding second voltage drop speed threshold based on the second remaining power and the target life status.

[0103] Optionally, in some embodiments, the step of "determining the corresponding second voltage drop speed threshold based on the second remaining power and the target life status" may specifically include:

[0104] Based on the target life status, determine the second abnormal battery cell from the set of abnormal battery cells; based on the second remaining power of the battery cell to be detected, determine the remaining power of the second abnormal battery cell; based on the remaining power of the second battery cell, obtain the second target voltage drop speed threshold from the second preset voltage drop speed set.

[0105] Specifically, based on the second remaining power and the target life status of the battery cell to be detected, obtain the corresponding second target voltage drop speed threshold from the pre-constructed second preset voltage drop speed threshold set.

[0106] 205. Compare the target voltage drop speed with the second voltage drop speed threshold to determine the self-discharge status of the battery cell to be detected.

[0107] The target voltage drop speed K is calculated by measuring the voltage change of the battery cell in the static state. The specific formula is: K = (U3 - U4) / T, where: U3 is the static voltage of the battery cell after standing for 3 hours; U4 is the static voltage of the battery cell after standing for a further period of time (such as 24 hours); T is the time interval between measuring U3 and measuring U4.

[0108] The second voltage drop speed threshold is obtained through experimental tests in advance and is used to judge whether the self-discharge of the battery cell is abnormal at a specific remaining power. The threshold is determined according to the remaining power status of the battery cell. For example: when the remaining power is 30%, the second voltage drop speed threshold is 0.45 mV / h; when the remaining power is 40%, the second voltage drop speed threshold is 0.42 mV / h.

[0109] Optionally, in some embodiments, the step of "comparing the target voltage drop speed with the second voltage drop speed threshold to determine the self-discharge status of the battery cell to be detected" may specifically include:

[0110] If the target voltage drop rate is greater than or equal to the second voltage drop rate threshold, determine that the cell to be detected is the target abnormal cell; if the target voltage drop rate is less than the second voltage drop rate threshold, determine that the self-discharge of the cell to be detected is normal.

[0111] Specifically, compare the calculated target voltage drop rate K with the second voltage drop rate threshold at the corresponding remaining battery capacity. If K is greater than or equal to the second voltage drop rate threshold, it indicates that the self-discharge rate of the cell is too fast and there is self-discharge abnormality, and the cell to be detected is determined as the target abnormal cell; if K is less than the second voltage drop rate threshold, it indicates that the self-discharge rate of the cell is within the normal range, and the cell to be detected is determined as having normal self-discharge.

[0112] Optionally, in some embodiments, if the cell to be detected is the target abnormal cell, replace the cell to be detected.

[0113] As can be seen from the above, in this embodiment, when any cell to be detected switches from the discharging state to the static state, obtain the first static voltage of the cell to be detected at the first time point, the second static voltage at the second time point, and the time interval between the first time point and the second time point; based on the first static voltage, the second static voltage, and the time interval, determine the target voltage drop rate of the cell to be detected; obtain the second remaining battery capacity and the target life state of the cell to be detected when the discharging state ends; determine the corresponding second voltage drop rate threshold based on the second remaining battery capacity and the target life state; compare the target voltage drop rate with the second voltage drop rate threshold to determine the self-discharge state of the cell to be detected. In this embodiment, after determining the life state, different remaining battery capacities correspond to different voltage drop rate judgment criteria for the self-discharge state detection of the cell, thereby further improving the accuracy of the self-discharge state detection of the cell.

[0114] Correspondingly, an embodiment of the present application further provides an electronic device. Please refer to Figure 3 , Figure 3 is the first structural schematic diagram of the electronic device provided by the embodiment of the present application.

[0115] The electronic device 300 may include a processor 301 with one or more processing cores, a memory 302 with one or more computer-readable storage media, and other components. Among them, the processor 301 is electrically connected to the memory 302. Those skilled in the art can understand that Figure 3 the structure of the electronic device shown in

[0116] The processor 301 is the control center of the electronic device 300 and may include one or more processing cores. The processor 301 connects various parts of the entire electronic device through various interfaces and circuits, and executes various functions of the electronic device and processes data by running or calling computer programs stored in the memory 302 and calling data stored in the memory 302, thereby performing overall management and control of the electronic device. Optionally, the processor 301 may be implemented in at least one hardware form of digital signal processing (DSP), field programmable gate array (FPGA), or programmable logic array (PLA). The processor 301 may integrate one or a combination of several of a CPU, a graphics processing unit (GPU), and a modem. Among them, the CPU mainly processes the operating system, user pages, application programs, etc.; the GPU is responsible for rendering and drawing display content; the modem is used to process wireless communication. It can be understood that the above modem may not be integrated into the processor 301 and may be implemented separately through a communication chip.

[0117] The memory 302 can be used to store software programs and modules. The processor 301 executes various functional applications and data processing by running the computer programs and modules stored in the memory 302. The memory 302 mainly includes a program storage area and a data storage area. Among them, the program storage area can store the operating system, computer programs required for at least one function, etc.; the data storage area can store data created according to the use of the electronic device.

[0118] In addition, the memory 302 may include high-speed random access memory and may also include non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage devices. Correspondingly, the memory 302 may further include a memory controller to provide the processor 301 with access to the memory 302.

[0119] In the embodiment of the present application, the processor 301 in the electronic device 300 loads the instructions corresponding to the processes of one or more computer programs into the memory 302 according to the following steps, and the processor 301 runs the computer programs stored in the memory 302 to implement various functions as follows:

[0120] When any cell to be detected switches from a discharging state to a stationary state, obtain the first static voltage of the cell to be detected at a first time point, the second static voltage at a second time point, and the time interval between the first time point and the second time point;

[0121] Determine the target voltage drop rate of the battery cell to be detected based on the first static voltage, the second static voltage, and the interval duration.

[0122] Obtain the first remaining power of the battery cell to be detected when the discharge state ends, and determine the corresponding first voltage drop rate threshold based on the first remaining power.

[0123] Compare the target voltage drop rate with the first voltage drop rate threshold to determine the self-discharge state of the battery cell to be detected.

[0124] Optionally, in some embodiments of the present application, before the processor obtains the first static voltage of the battery cell to be detected at the first time point, the second static voltage at the second time point, and the interval duration between the first time point and the second time point when any battery cell to be detected switches from the discharge state to the stationary state, the processor further specifically executes: obtaining the first abnormal battery cell of the battery system; performing full charge and discharge on the first abnormal battery cell at a preset temperature, and adjusting the first abnormal battery cell to the first preset remaining power; when the first abnormal battery cell is at the first preset remaining power, obtaining the first preset voltage of the first abnormal battery cell at the first time point, the second preset voltage at the second time point, and the interval duration between the first time point and the second time point; determining the first preset voltage drop rate threshold corresponding to the first abnormal battery cell at the first preset remaining power based on the first preset voltage, the second preset voltage, and the interval duration; and forming a first preset voltage drop rate threshold set with different preset voltage drop rate thresholds corresponding to the first abnormal battery cell at different remaining powers.

[0125] Optionally, in some embodiments of the present application, when the processor executes to determine the corresponding first voltage drop rate threshold based on the first remaining power, the processor specifically executes: determining the remaining power of the first abnormal battery cell based on the first remaining power of the battery cell to be detected; and obtaining the first target voltage drop rate threshold from the first preset voltage drop rate threshold set based on the remaining power of the first abnormal battery cell.

[0126] Optionally, in some embodiments of the present application, when the processor executes to compare the target voltage drop rate with the first voltage drop rate threshold to determine the self-discharge state of the battery cell to be detected, the processor specifically executes: if the target voltage drop rate is greater than or equal to the first voltage drop rate threshold, determining that the battery cell to be detected is the target abnormal battery cell; if the target voltage drop rate is less than the first voltage drop rate threshold, determining that the self-discharge of the battery cell to be detected is normal.

[0127] Optionally, in some embodiments of the present application, after the processor determines the target voltage drop rate of the battery cell to be detected based on the first static voltage, the second static voltage, and the interval duration, it further specifically performs: obtaining the second remaining power and the target life state of the battery cell to be detected when the discharge state ends; determining the corresponding second voltage drop rate threshold based on the second remaining power and the target life state; comparing the target voltage drop rate with the second voltage drop rate threshold to determine the self-discharge state of the battery cell to be detected.

[0128] Optionally, in some embodiments of the present application, before the processor obtains the first static voltage of the battery cell to be detected at the first time point, the second static voltage at the second time point, and the interval duration between the first time point and the second time point when any battery cell to be detected switches from the discharge state to the stationary state, it is further configured to perform: obtaining a set of abnormal battery cells of the battery system, where the set of abnormal battery cells includes abnormal battery cells with different life states; performing full charge and discharge on the second abnormal battery cell at a preset temperature and adjusting the second abnormal battery cell to a second preset remaining power, where the second abnormal battery cell is any abnormal battery cell with a life state in the set of abnormal battery cells; when the second abnormal battery cell is at the second preset remaining power, obtaining the third preset voltage of the second abnormal battery cell at the first time point, the fourth preset voltage at the second time point, and the interval duration between the first time point and the second time point; determining the second preset voltage drop rate threshold corresponding to the second abnormal battery cell at the second preset remaining power based on the third preset voltage, the fourth preset voltage, and the interval duration; and forming a second preset voltage drop rate threshold set with different preset voltage drop rate thresholds corresponding to abnormal battery cells with different life states in different remaining powers in the set of abnormal battery cells.

[0129] Optionally, in some embodiments of the present application, when the processor determines the corresponding second voltage drop rate threshold based on the second remaining power and the target life state, it specifically performs: determining the second abnormal battery cell from the set of abnormal battery cells based on the target life state; determining the remaining power of the second abnormal battery cell based on the second remaining power of the battery cell to be detected; and obtaining the second target voltage drop rate threshold from the second preset voltage drop rate set based on the remaining power of the second battery cell.

[0130] Optionally, in some embodiments of the present application, when the processor compares the target voltage drop rate with the second voltage drop rate threshold to determine the self-discharge state of the battery cell to be detected, it specifically performs: if the target voltage drop rate is greater than or equal to the second voltage drop rate threshold, determining that the battery cell to be detected is the target abnormal battery cell; if the target voltage drop rate is less than the second voltage drop rate threshold, determining that the self-discharge of the battery cell to be detected is normal.

[0131] Optionally, in some embodiments of the present application, the processor is further configured to perform: if the battery cell to be detected is a target abnormal battery cell, replace the battery cell to be detected.

[0132] For the specific implementation of each of the above operations, reference may be made to the previous embodiments and will not be elaborated herein.

[0133] When any battery cell to be detected switches from the discharging state to the static state in the embodiments of the present application, the first static voltage of the battery cell to be detected at the first time point, the second static voltage at the second time point, and the time interval between the first time point and the second time point are obtained; based on the first static voltage, the second static voltage, and the time interval, the target voltage drop rate of the battery cell to be detected is determined; the first remaining power of the battery cell to be detected at the end of the discharging state is obtained, and the corresponding first voltage drop rate threshold is determined based on the first remaining power; the target voltage drop rate is compared with the first voltage drop rate threshold to determine the self-discharge state of the battery cell to be detected. In the present application, the detection of the self-discharge state of the battery cell has different voltage drop rate judgment criteria corresponding to different remaining powers, thereby improving the accuracy of the detection of the self-discharge state of the battery cell.

[0134] Those of ordinary skill in the art can understand that all or part of the steps in the above-mentioned various methods can be completed by instructions, or by controlling relevant hardware through instructions. The instructions can be stored in a computer-readable storage medium and loaded and executed by a processor.

[0135] Therefore, an embodiment of the present application provides a computer-readable storage medium, in which multiple instructions are stored, and the instructions can be loaded by a processor to execute the steps in any of the methods for detecting the self-discharge state of a battery cell provided by the embodiments of the present application. For example, the instructions can perform the following steps:

[0136] When any battery cell to be detected switches from the discharging state to the static state, obtain the first static voltage of the battery cell to be detected at the first time point, the second static voltage at the second time point, and the time interval between the first time point and the second time point; based on the first static voltage, the second static voltage, and the time interval, determine the target voltage drop rate of the battery cell to be detected; obtain the first remaining power of the battery cell to be detected at the end of the discharging state, and determine the corresponding first voltage drop rate threshold based on the first remaining power; compare the target voltage drop rate with the first voltage drop rate threshold to determine the self-discharge state of the battery cell to be detected.

[0137] For the specific implementation of each of the above operations, reference may be made to the previous embodiments and will not be elaborated herein.

[0138] Among them, the storage medium may include: read-only memory (ROM, Read Only Memory), random access memory (RAM, Random Access Memory), magnetic disk, optical disk, etc.

[0139] Since the instructions stored in the storage medium can execute the steps in any of the methods for detecting the self-discharge state of the battery cell provided in the embodiments of the present application, the beneficial effects achievable by any of the methods for detecting the self-discharge state of the battery cell provided in the embodiments of the present application can be realized. For details, refer to the previous embodiments and will not be elaborated here.

[0140] The above has introduced in detail a method for detecting the self-discharge state of a battery cell, an electronic device, and a storage medium provided in the embodiments of the present application. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A method for detecting the self-discharge state of a battery cell, characterized in that: Applied to an electronic device, the electronic device includes a battery system, the battery system includes a plurality of cells to be tested, and the method includes: When any of the cells to be detected is switched from a discharge state to a static state, obtaining a first static voltage of the cell to be detected at a first time point, a second static voltage at a second time point, and an interval between the first time point and the second time point; Determining a target voltage drop rate of the battery cell to be tested based on the first static voltage, the second static voltage and the interval duration; Acquire a first remaining capacity of the battery cell to be detected when the discharge state is terminated, and determine a corresponding first voltage drop rate threshold based on the first remaining capacity; The target voltage drop rate is compared with the first voltage drop rate threshold to determine the self-discharge state of the battery cell to be detected.

2. The method for detecting the self-discharge state of a battery cell according to claim 1, characterized in that: When any of the cells to be detected is switched from a discharge state to a static state, before obtaining a first static voltage of the cell to be detected at a first time point, a second static voltage at a second time point, and an interval between the first time point and the second time point, the method further includes: Acquire a first abnormal battery cell of the battery system; At a preset temperature, fully charge and discharge the first abnormal battery cell, and adjust the first abnormal battery cell to a first preset remaining power; When the first abnormal battery cell is at the first preset remaining power, obtaining a first preset voltage of the first abnormal battery cell at the first time point, a second preset voltage at the second time point, and an interval between the first time point and the second time point; Based on the first preset voltage, the second preset voltage, and the interval duration, determining a first preset voltage drop rate threshold corresponding to the first abnormal battery cell at the first preset remaining power; Different preset voltage drop rate thresholds corresponding to the first abnormal battery cell at different remaining capacities form a first preset voltage drop rate threshold set.

3. The method for detecting the self-discharge state of a battery cell according to claim 2, characterized in that: The determining a corresponding first voltage drop rate threshold based on the first remaining power includes: Determining the remaining power of the first abnormal battery cell based on the first remaining power of the battery cell to be detected; Based on the remaining power of the first abnormal battery cell, the first target voltage drop rate threshold is obtained from the first preset voltage drop rate threshold set.

4. The method for detecting the self-discharge state of a battery cell according to claim 3, characterized in that: The step of comparing the target voltage drop rate with the first voltage drop rate threshold to determine the self-discharge state of the battery cell to be detected includes: If the target voltage drop rate is greater than or equal to the first voltage drop rate threshold, determining that the battery cell to be detected is a target abnormal battery cell; If the target voltage drop rate is less than the first voltage drop rate threshold, it is determined that the self-discharge of the battery cell to be detected is normal.

5. The method for detecting the self-discharge state of a battery cell according to claim 1, characterized in that: After determining the target voltage drop rate of the battery cell to be tested based on the first static voltage, the second static voltage and the interval duration, the method further includes: Obtaining a second remaining power and a target life state of the battery cell to be detected when the discharge state is terminated; Determine a corresponding second voltage drop rate threshold based on the second remaining power and the target life state; The target voltage drop rate is compared with the second voltage drop rate threshold to determine the self-discharge state of the battery cell to be detected.

6. The method for detecting the self-discharge state of a battery cell according to claim 5, characterized in that: When any of the cells to be detected is switched from a discharge state to a static state, before obtaining a first static voltage of the cell to be detected at a first time point, a second static voltage at a second time point, and an interval between the first time point and the second time point, the method further includes: Acquire a set of abnormal cells of the battery system, wherein the set of abnormal cells includes abnormal cells in different life states; At a preset temperature, fully charge and discharge the second abnormal battery cell, and adjust the second abnormal battery cell to a second preset remaining power, wherein the second abnormal battery cell is an abnormal battery cell of any life state in the abnormal battery cell set; When the second abnormal battery cell is at the second preset remaining power, obtaining a third preset voltage of the second abnormal battery cell at the first time point, a fourth preset voltage at the second time point, and an interval between the first time point and the second time point; Based on the third preset voltage, the fourth preset voltage and the interval time, determining a second preset voltage drop rate threshold corresponding to the second abnormal battery cell at the second preset remaining power; The abnormal cells in the abnormal cell set that are in different life states and have different preset voltage drop rate thresholds corresponding to the abnormal cells at different remaining capacities form a second preset voltage drop rate threshold set.

7. The method for detecting the self-discharge state of a battery cell according to claim 6, characterized in that: The determining a corresponding second voltage drop rate threshold based on the second remaining power and the target life state includes: Based on the target life state, determining the second abnormal battery cell from the abnormal battery cell set; Determining the remaining power of the second abnormal battery cell based on the second remaining power of the battery cell to be detected; Based on the remaining power of the second battery cell, the second target voltage drop rate threshold is obtained from the second preset voltage drop rate set.

8. The method for detecting the self-discharge state of a battery cell according to claim 7, characterized in that: The step of comparing the target voltage drop rate with the second voltage drop rate threshold to determine the self-discharge state of the battery cell to be detected includes: If the target voltage drop rate is greater than or equal to the second voltage drop rate threshold, determining that the battery cell to be detected is a target abnormal battery cell; If the target voltage drop rate is less than the second voltage drop rate threshold, it is determined that the self-discharge of the battery cell to be detected is normal.

9. The method for detecting the self-discharge state of a battery cell according to claim 4 or 8, characterized in that: The method further comprises: If the battery cell to be detected is the target abnormal battery cell, the battery cell to be detected is replaced.

10. An electronic device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the method for detecting the self-discharge state of the battery cell as described in any one of claims 1 to 9 are implemented.

11. A computer-readable storage medium, characterized in that: A computer program is stored thereon, wherein when the computer program is executed by a processor, the steps of the method for detecting the self-discharge state of a battery cell as claimed in any one of claims 1 to 9 are implemented.

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