Method and device for adjusting self-discharge rate threshold value of battery cell, equipment and medium

Abstract

The invention provides a cell self-discharge rate threshold adjustment method, device, equipment and medium, and relates to the technical field of battery self-discharge detection.The method comprises the steps that first self-discharge rates of a plurality of cells are obtained after the plurality of cells stand for a first duration, and second self-discharge rates of the plurality of cells are obtained after the plurality of cells stand for a second duration, the first duration is smaller than the second duration; based on the second self-discharge rate, the first self-discharge rate threshold value is adjusted to obtain a second self-discharge rate threshold value, and the first self-discharge rate threshold value is determined based on the multiple first self-discharge rates. According to the invention, the accuracy of the self-discharge rate threshold can be improved, and the accuracy of abnormal cell screening is further improved.

Description

Technical Field

[0001] This application relates to the technical field of battery self-discharge detection, and particularly relates to a method, device, equipment and medium for adjusting the self-discharge rate threshold of a battery cell. Background Art

[0002] Currently, the screening of battery cells with excessive self-discharge is carried out according to the self-discharge rate threshold. However, due to the lack of reliability in the determination process of the self-discharge rate threshold, the self-discharge rate threshold is not accurate enough, which in turn leads to inaccurate screening of battery cells. Summary of the Invention

[0003] Embodiments of this application provide a method, device, equipment and medium for adjusting the self-discharge rate threshold of a battery cell, providing a reliable determination process for the self-discharge rate threshold, improving the accuracy of the self-discharge rate threshold, and further improving the accuracy of battery cell screening.

[0004] In a first aspect, embodiments of this application provide a method for adjusting the self-discharge rate threshold of a battery cell, including the following steps:

[0005] Obtain the first self-discharge rates of multiple battery cells after the multiple battery cells are static for a first duration, and obtain the second self-discharge rates of the multiple battery cells after the multiple battery cells are static for a second duration, where the first duration is less than the second duration;

[0006] Based on the second self-discharge rates, adjust the first self-discharge rate threshold to obtain a second self-discharge rate threshold, where the first self-discharge rate threshold is determined based on multiple first self-discharge rates.

[0007] In some embodiments, adjusting the first self-discharge rate threshold based on the second self-discharge rates includes:

[0008] Perform a normal distribution analysis on multiple second self-discharge rates to obtain a normal analysis result;

[0009] In the case where the normal analysis result indicates the existence of discrete points, adjust the first self-discharge rate threshold.

[0010] In some embodiments, adjusting the first self-discharge rate threshold based on the second self-discharge rates includes:

[0011] Analyze the correlation between the first self-discharge rate and the second self-discharge rate, and in the case where the obtained first correlation coefficient does not meet the preset correlation coefficient threshold, adjust the first self-discharge rate threshold.

[0012] In some embodiments, adjusting the first self-discharge rate threshold based on the second self-discharge rates includes:

[0013] Perform a normal distribution analysis on multiple second self-discharge rates to obtain a normal analysis result;

[0014] In the case where the normal analysis result is characterized by the presence of discrete points, adjust the standing condition corresponding to the first self-discharge rate threshold to obtain a new normal analysis result corresponding to the new second self-discharge rate;

[0015] In the case where the new normal analysis result is characterized by the absence of discrete points, obtain the new first self-discharge rate and the new second self-discharge rate of the battery cell after the standing condition is adjusted;

[0016] Analyze the correlation between the new first self-discharge rate and the new second self-discharge rate, and adjust the first self-discharge rate threshold when the obtained second correlation coefficient does not meet the preset correlation coefficient threshold.

[0017] In some embodiments, adjusting the first self-discharge rate threshold to obtain the second self-discharge rate threshold includes:

[0018] Lower the first self-discharge rate threshold to obtain the second self-discharge rate threshold;

[0019] Alternatively, adjust the standing condition corresponding to the first self-discharge rate threshold, obtain the new first self-discharge rate after the standing condition is adjusted, and calculate the second self-discharge rate threshold based on the new first self-discharge rate, where the standing condition includes the standing time, the standing temperature, and the SOC of the battery cell.

[0020] In some embodiments, after obtaining the second self-discharge rate threshold, the method further includes:

[0021] Screen abnormal battery cells based on the second self-discharge rate threshold.

[0022] In some embodiments, obtaining the first self-discharge rate of multiple battery cells and obtaining the second self-discharge rate of multiple battery cells includes:

[0023] Obtain the first open-circuit voltage, the second open-circuit voltage, and the third open-circuit voltage of multiple battery cells at the first time point, the second time point, and the third time point respectively, where the difference between the first time point and the second time point is the first duration, and the difference between the second time point and the third time point is the second duration;

[0024] Calculate the first self-discharge rate based on the first open-circuit voltage, the second open-circuit voltage, and the first duration, and calculate the second self-discharge rate based on the second open-circuit voltage, the third open-circuit voltage, and the second duration.

[0025] In some embodiments, the first self-discharge rate threshold is determined by the following method:

[0026] Obtain the first mean and the first standard deviation of multiple first self-discharge rates, and determine the first discrete point based on the first mean, the first standard deviation, and the first standard deviation coefficient;

[0027] Perform a forward verification on the battery cell corresponding to the first discrete point, and determine the first self-discharge rate threshold according to the verification result;

[0028] Perform a normal distribution analysis on multiple second self-discharge rates to obtain a normal analysis result, including:

[0029] Obtain the second mean and the second standard deviation of the multiple second self-discharge rates, and determine the normal analysis result based on the second mean, the second standard deviation, and the second standard deviation coefficient. Among them, the normal analysis result is whether there is a second discrete point, and the first standard deviation coefficient is greater than the second standard deviation coefficient.

[0030] In a second aspect, an embodiment of the present application further provides an adjustment device for the self-discharge rate threshold of a battery cell. The device includes:

[0031] An acquisition module, configured to acquire the first self-discharge rates of multiple battery cells after the multiple battery cells are static for a first duration, and acquire the second self-discharge rates of the multiple battery cells after the multiple battery cells are static for a second duration, where the first duration is less than the second duration;

[0032] An adjustment module, configured to adjust the first self-discharge rate threshold based on the second self-discharge rate to obtain a second self-discharge rate threshold, where the first self-discharge rate threshold is determined based on multiple first self-discharge rates.

[0033] In the present application, the implementation manners of the modules included in the device are not limited. For example, the acquisition module and the adjustment module can be integrated into a processing module, or split into more sub-modules.

[0034] In a third aspect, an embodiment of the present application further provides an electronic device. The electronic device includes: at least one processor; and a memory communicatively connected to the at least one processor;

[0035] Wherein, the memory stores a computer program executable by the at least one processor. The computer program is executed by the at least one processor so that the at least one processor can execute the steps in the adjustment method for the self-discharge rate threshold of a battery cell according to any one of the above embodiments.

[0036] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. The computer program is loaded by a processor to execute the steps in the adjustment method for the self-discharge rate threshold of a battery cell according to any one of the above embodiments.

[0037] The method for adjusting the self-discharge rate threshold of an electric cell provided by an embodiment of the present application uses a second self-discharge rate to verify whether a first self-discharge rate threshold is accurate, and adjusts the first self-discharge rate threshold when the first self-discharge rate threshold is inaccurate, where the first self-discharge rate threshold is determined according to a first self-discharge rate. That is, a second self-discharge rate is calculated through long-term (second duration) data, and the second self-discharge rate is used to verify the first self-discharge rate threshold determined based on short-term (first duration) data, and the first self-discharge rate threshold is adjusted according to the verification result to improve the accuracy of the self-discharge rate threshold, thereby improving the accuracy of abnormal electric cell screening. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the accompanying drawings required for the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those skilled in the art, other accompanying drawings can be obtained based on these drawings without creative efforts.

[0039] Figure 1 is a flowchart of the method for adjusting the self-discharge rate threshold of an electric cell provided by some embodiments of the present application;

[0040] Figure 2 is a normal distribution diagram of the second self-discharge rate K2 provided by some embodiments of the present application;

[0041] Figure 3 is a normal distribution diagram of the first self-discharge rate K1 provided by some embodiments of the present application;

[0042] Figure 4 is a self-discharge diagram of an electric cell provided by some embodiments of the present application;

[0043] Figure 5 is a correlation analysis diagram of the first self-discharge rate K1 and the second self-discharge rate K2 provided by some embodiments of the present application;

[0044] Figure 6 is a structural diagram of the device for adjusting the self-discharge rate threshold of an electric cell provided by some embodiments of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to 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 of the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present application.

[0046] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, the meaning of "a plurality" is two or more unless otherwise specifically defined.

[0047] "A and / or B" includes the following three combinations: only A, only B, and the combination of A and B.

[0048] The use of "is applicable to" or "is configured to" in the present application means open and inclusive language, which does not exclude a device that is applicable to or configured to perform additional tasks or steps. Additionally, the use of "based on" means open and inclusive because a process, step, calculation, or other action "based on" one or more conditions or values can in practice be based on additional conditions or values beyond those stated.

[0049] In the present application, the term "exemplary" is used to mean "serving as an example, illustration, or explanation". Any embodiment described as "exemplary" in the present application is not necessarily to be construed as more preferred or advantageous than other embodiments. In order for any person skilled in the art to implement and use the present application, the following description is provided. In the following description, details are set forth for purposes of explanation. It should be understood that those of ordinary skill in the art can recognize that the present application can be implemented without the use of these specific details. In other instances, well-known structures and processes are not elaborated in detail to avoid obscuring the description of the present application with unnecessary details. Therefore, the present application is not intended to be limited to the embodiments shown, but rather to be consistent with the broadest scope that conforms to the principles and features disclosed in the present application.

[0050] When the battery is in an open-circuit storage state, a phenomenon of spontaneous capacity loss will occur. Excessive self-discharge will cause the storage voltage of the battery to drop too fast, affecting the consistency, life, and capacity of the battery voltage. Therefore, the screening of self-discharge is extremely important during the production process of the battery cells.

[0051] Self-discharge can be divided into physical self-discharge and chemical self-discharge. Among them, the power consumption behavior of SEI film formation is the main source of chemical self-discharge, resulting in irreparable power loss. Physical self-discharge is mainly caused by internal micro-shorts. The reasons for micro-shorts mainly include dust particles, diaphragm breakage, tab warping and contacting the shell, abnormal diaphragm incoming materials, etc. during the battery manufacturing process. Abnormal physical self-discharge will cause the voltage of the battery cell to be low, thus triggering the differential pressure alarm of the battery management system (BMS). Therefore, the screening of battery cells with abnormal physical self-discharge is particularly important.

[0052] Currently, self-discharge screening uses a self-discharge rate threshold to screen abnormal self-discharging battery cells. The determination process of the self-discharge rate threshold includes: based on a set standard deviation coefficient, performing a normal distribution analysis on the self-discharge rate values of multiple battery cells collected to determine discrete points from multiple battery cells, and then verifying the set standard deviation coefficient through positive verification of the discrete points to determine whether it is reasonable. When it is reasonable, determine the self-discharge rate threshold related to the set standard deviation coefficient; when it is unreasonable, adjust the set standard deviation coefficient and determine the self-discharge rate threshold related to the adjusted standard deviation coefficient. However, due to the non-linearity and hysteresis of chemical self-discharge, the self-discharge rate threshold determined only by the above process may be too low or too high, resulting in inaccurate self-discharge screening.

[0053] In view of this, the embodiments of the present application provide a method, device, equipment and medium for adjusting the self-discharge rate threshold of a battery cell. Among them, the method for adjusting the self-discharge rate threshold of a battery cell uses a second self-discharge rate to verify whether the first self-discharge rate threshold is accurate, and when the first self-discharge rate threshold is inaccurate, adjusts the first self-discharge rate threshold, where the first self-discharge rate threshold is determined according to the first self-discharge rate. That is, calculate the first self-discharge rate from short-term (i.e., the first duration) data, calculate the second self-discharge rate from long-term (i.e., the second duration) data, and use the second self-discharge rate to verify whether the first self-discharge rate threshold is accurate, and then adjust the first self-discharge rate threshold according to the verification result to improve the accuracy of the self-discharge rate threshold, thereby improving the accuracy of abnormal battery cell screening, and thus can solve at least part of the above technical problems.

[0054] On the one hand, the embodiments of the present application provide a method for adjusting the self-discharge rate threshold of a battery cell, as Figure 1 shown, the method for adjusting the self-discharge rate threshold of a battery cell includes the following steps:

[0055] S101, obtain the first self-discharge rate of multiple battery cells after the multiple battery cells are static for the first duration, and obtain the second self-discharge rate of the multiple battery cells after the multiple battery cells are static for the second duration.

[0056] Among them, the self-discharge rate refers to the rate of power loss caused by internal physical or chemical reactions per unit time under open-circuit static conditions of the battery. The first self-discharge rate and the second self-discharge rate can be calculated respectively based on the change values of the open-circuit voltage before and after the first static time and the second static time of the battery cell, or can be calculated respectively based on the capacity loss values before and after the first static time and the second static time.

[0057] Schematically, for multiple battery cells, the first static time can be carried out first and then the second static time can be continuously carried out, or the first static time can be carried out first and then the second static time can be carried out after an interval of a certain time, so as to obtain the first self-discharge rate and the second self-discharge rate. The above-mentioned first static time is less than the second static time. Schematically, if the first static time is a time in hours such as 24 - 72 hours, then the second static time is a time in days such as 7 - 30 days; if the first static time is a time in days such as 7 - 30 days, then the second static time is a time in months such as 3 - 12 months.

[0058] S102, based on the second self-discharge rate, adjust the first self-discharge rate threshold to obtain the second self-discharge rate threshold.

[0059] Among them, the first self-discharge rate threshold is determined based on multiple first self-discharge rates.

[0060] That is to say, first calculate the first self-discharge rate based on short-term (the first static time) data, determine the first self-discharge rate threshold according to the first self-discharge rate, then calculate the second self-discharge rate based on long-term (the second static time) data, and use the second self-discharge rate to verify the first self-discharge rate threshold, and adjust the first self-discharge rate threshold according to the verification result to obtain the second self-discharge rate threshold.

[0061] In this step, since the inaccuracy of the first self-discharge rate threshold is mainly because the chemical self-discharge is not eliminated thoroughly enough, and the correlation between the first self-discharge rate and the second self-discharge rate can show whether the chemical self-discharge is eliminated thoroughly and whether the first self-discharge rate threshold is determined only based on physical self-discharge. It can be understood that since the chemical self-discharge exhibits non-linear change characteristics and the physical self-discharge has a linear relationship with time, therefore, if the chemical self-discharge has been eliminated thoroughly and only physical self-discharge remains in the battery cell, there is a high correlation between the second self-discharge rate determined based on long-term data and the first self-discharge rate determined based on short-term data; if the chemical self-discharge is not eliminated thoroughly enough, the correlation between the second self-discharge rate and the first self-discharge rate is low. To sum up, the second self-discharge rate can be used to verify whether the first self-discharge rate threshold is accurate. If there is a high correlation between the first self-discharge rate and the second self-discharge rate, it is determined that the first self-discharge rate threshold is relatively accurate and there is no need to adjust the first self-discharge rate threshold; if the correlation between the first self-discharge rate and the second self-discharge rate is low, it is determined that the first self-discharge rate threshold is not accurate enough and the first self-discharge rate threshold needs to be adjusted.

[0062] After adjusting the first self-discharge rate threshold, a second self-discharge rate threshold is obtained, and abnormal battery cells are screened based on the second self-discharge rate threshold. Schematically, the second self-discharge rate threshold is compared with the first self-discharge rate. If the first self-discharge rate is greater than the second self-discharge rate threshold, the corresponding battery cell is determined to be an abnormal battery cell. If the first self-discharge rate is less than or equal to the second self-discharge rate threshold, the corresponding battery cell is determined to be a normal battery cell.

[0063] Without the need to adjust the first self-discharge rate threshold, abnormal battery cells are screened based on the first self-discharge rate threshold. That is, the first self-discharge rate is compared with the first self-discharge rate threshold, and when the first self-discharge rate is greater than the first self-discharge rate threshold, the corresponding battery cell is determined to be an abnormal battery cell; when the first self-discharge rate is less than or equal to the first self-discharge rate threshold, the corresponding battery cell is determined to be a normal battery cell.

[0064] The method for adjusting the self-discharge rate threshold of the battery cell provided by the embodiments of the present application uses the second self-discharge rate to verify whether the first self-discharge rate threshold is accurate, and adjusts the first self-discharge rate threshold when the first self-discharge rate threshold is inaccurate, where the first self-discharge rate threshold is determined according to the first self-discharge rate. That is, the second self-discharge rate calculated based on long-term (i.e., the second duration) data is used to verify the first self-discharge rate threshold determined based on short-term (i.e., the first duration) data, and the first self-discharge rate threshold is adjusted according to the verification result to improve the accuracy of the self-discharge rate threshold, thereby improving the accuracy of abnormal battery cell screening.

[0065] In some embodiments of the present application, adjusting the first self-discharge rate threshold based on the second self-discharge rate includes:

[0066] Perform a normal distribution analysis on multiple second self-discharge rates to obtain a normal analysis result.

[0067] When the normal analysis result shows the existence of discrete points, adjust the first self-discharge rate threshold.

[0068] In this embodiment, it is determined whether the first self-discharge rate threshold is accurate based on the normal analysis result of the second self-discharge rate. It can be understood that if the second self-discharge rate does not show a normal distribution around the mean but discrete points appear, it indicates that the chemical self-discharge of the battery cell during the second-duration standing process has not been completely eliminated. Then, based on the characteristic that physical self-discharge is a stable linear process, it can be determined that the chemical self-discharge during the first-duration standing process before the second duration must also not have been completely eliminated, and a linear relationship between the first self-discharge rate and the second self-discharge rate cannot be presented in the state where the battery cell has only physical self-discharge. Therefore, it is determined that the first self-discharge rate threshold is inaccurate, and then the first self-discharge rate threshold needs to be adjusted.

[0069] As a possible implementation, calculate the mean and standard deviation corresponding to multiple second self-discharge rates, and perform a normal distribution analysis on the multiple second self-discharge rates using a set standard deviation coefficient. If the normal analysis result shows discrete points of the second self-discharge rate, it indicates that the value of the first self-discharge rate affected by chemical self-discharge is not accurate enough. Correspondingly, the first self-discharge rate threshold determined based on the first self-discharge rate is also not accurate enough and needs to be adjusted. If the normal analysis result shows no discrete points of the second self-discharge rate and all second self-discharge rates are within the normal range, the first self-discharge rate may only reflect physical self-discharge or may reflect both physical self-discharge and chemical self-discharge, which can be determined through further data analysis. Here, when it is determined that the normal analysis result shows no discrete points, the first self-discharge rate threshold is not adjusted. Schematically, divide the numerical range of N second self-discharge rates into intervals, count the frequencies of the N second self-discharge rates in each range interval, and draw a histogram of the second self-discharge rate K2 as shown in Figure 2 and determine the normal range (i.e., the numerical range covered between the black dotted lines in Figure 2 ) based on the set standard deviation coefficient, the mean and standard deviation corresponding to the second self-discharge rate. If the second self-discharge rate K2 exceeds this normal range, determine the second self-discharge rate K2 as a discrete point. It should be understood that the larger the set standard deviation coefficient, the larger the normal range; conversely, the smaller the set standard deviation coefficient, the smaller the normal range, Figure 2 and the distance between the black dotted lines in

[0070] changes continuously according to the size of the set standard deviation coefficient. In other embodiments of the present application, the normal analysis result can also be determined based on other methods such as the Q-Q plot (Quantile-Quantile Plot) or P-P plot (Probability-Probability Plot) of the N second self-discharge rates.

[0071] The method for adjusting the self-discharge rate threshold of an electric cell provided by the embodiments of the present application analyzes the normal distribution of multiple second self-discharge rates, and when the normal analysis result shows the existence of discrete points, adjusts the first self-discharge rate threshold to improve the accuracy of the self-discharge rate threshold and further improve the accuracy of abnormal electric cell screening.

[0072] In some embodiments of the present application, adjusting the first self-discharge rate threshold based on the second self-discharge rate includes:

[0073] Analyze the correlation between the first self-discharge rate and the second self-discharge rate, and when the obtained first correlation coefficient does not meet the preset correlation coefficient threshold, adjust the first self-discharge rate threshold.

[0074] In this embodiment, if the chemical self-discharge is eliminated thoroughly, both the first self-discharge rate calculated based on short-term data and the second self-discharge rate calculated based on long-term data only reflect the physical self-discharge. Also, due to the linear characteristics of the physical self-discharge, the first self-discharge rate should be highly correlated with the second self-discharge rate. Therefore, the accuracy of the first self-discharge rate threshold is verified by analyzing the correlation between the first self-discharge rate and the second self-discharge rate.

[0075] As a possible implementation, the first correlation coefficient is obtained by calculating the Pearson correlation coefficient between the first self-discharge rate and the second self-discharge rate; it can also be a polynomial regression analysis of the first self-discharge rate and the second self-discharge rate, and the first correlation coefficient is determined based on the analysis result; it can also be determined whether the first self-discharge rate and the second self-discharge rate belong to the same probability distribution through the K-S test (Kolmogorov–Smirnov Test), and the first correlation coefficient is determined based on the probability distribution result; in addition, the first correlation coefficient can also be determined by calculating the multi-dimensional distance between the first self-discharge rate and the second self-discharge rate, and so on. After determining the first correlation coefficient, if the first correlation coefficient is less than the preset correlation coefficient threshold, it indicates that the correlation between the first self-discharge rate and the second self-discharge rate is low, and the corresponding first self-discharge rate threshold is too high due to the existence of chemical self-discharge and needs to be further adjusted. If the first correlation coefficient is greater than or equal to the preset correlation coefficient threshold, it is determined that the correlation between the first self-discharge rate and the second self-discharge rate is high, and there is no need to adjust the first self-discharge rate threshold.

[0076] The method for adjusting the self-discharge rate threshold of an electric cell provided by the embodiments of the present application determines the first correlation coefficient between the first self-discharge rate and the second self-discharge rate through the correlation analysis between the first self-discharge rate and the second self-discharge rate, and when the first correlation coefficient does not meet the preset correlation coefficient threshold, adjusts the first self-discharge rate threshold, thereby improving the accuracy of the self-discharge rate threshold and further improving the accuracy of abnormal electric cell screening.

[0077] In some embodiments of the present application, adjusting the first self-discharge rate threshold based on the second self-discharge rate includes:

[0078] Performing a normal distribution analysis on multiple second self-discharge rates to obtain a normal analysis result.

[0079] In the case where the normal analysis result indicates the existence of discrete points, adjust the standing condition corresponding to the first self-discharge rate threshold to obtain a new normal analysis result corresponding to the new second self-discharge rate. It can be understood that the standing condition is the standing condition for the battery cell to remove the chemical self-discharge stage. Different standing conditions affect whether the chemical self-discharge is completely eliminated, and thus affect the first self-discharge rate threshold. The standing condition can specifically be the standing environment of the battery cell (such as temperature, humidity, duration, etc.), or the initial standing state of the battery cell (such as the SOC of the battery cell, etc.). Adjusting the standing condition corresponding to the first self-discharge rate threshold means adjusting the standing condition that generates the first self-discharge rate threshold.

[0080] In the case where the new normal analysis result indicates the absence of discrete points, obtain the new first self-discharge rate and the new second self-discharge rate of multiple battery cells after the standing condition is adjusted.

[0081] Analyze the correlation between the new first self-discharge rate and the new second self-discharge rate, and adjust the first self-discharge rate threshold when the obtained second correlation coefficient does not meet the preset correlation coefficient threshold.

[0082] In this embodiment, first perform a normal distribution analysis on multiple second self-discharge rates. When the normal analysis result indicates the absence of discrete points, directly perform a correlation analysis based on the first self-discharge rate and the second self-discharge rate without adjusting the standing condition. When the normal analysis result indicates the existence of discrete points, adjust the standing condition corresponding to the first self-discharge rate threshold. After the standing condition is adjusted, let new battery cells stand, and continuously obtain the new first self-discharge rate and the new second self-discharge rate corresponding to the new battery cells. Also, perform a normal distribution analysis after each new second self-discharge rate is obtained to obtain a new normal analysis result corresponding to the new second self-discharge rate. Stop the iteration when the new normal analysis result shows the absence of discrete points, and further adjust the standing condition when the new normal analysis result shows the existence of discrete points, and then obtain the new normal analysis result for the next round. Until the normal analysis result indicates the absence of discrete points, use the new first self-discharge rate and the new second self-discharge rate calculated during this round as the latest first self-discharge rate and the latest second self-discharge rate, and then perform a correlation analysis based on the latest first self-discharge rate and the latest second self-discharge rate. When the obtained second correlation coefficient is less than the preset correlation coefficient threshold, adjust the new first self-discharge rate threshold. When the second correlation coefficient is greater than or equal to the preset correlation coefficient threshold, do not adjust the new first self-discharge rate threshold.

[0083] Similarly to the first correlation coefficient, the second correlation coefficient can also be determined by means of Pearson correlation coefficient, polynomial regression analysis, K-S test, etc. The first correlation coefficient is obtained by performing a correlation analysis on the first self-discharge rate and the second self-discharge rate. The second correlation coefficient can be obtained by performing a correlation analysis on the first self-discharge rate and the second self-discharge rate (i.e., without adjusting the standing condition), or can be obtained by performing a correlation analysis on the new first self-discharge rate and the new second self-discharge rate (i.e., under the adjusted standing condition).

[0084] In the method for adjusting the self-discharge rate threshold of the battery cell provided in the embodiments of the present application, first, a normal distribution analysis is performed on the second self-discharge rate. When the normal analysis result shows the existence of discrete points, the standing condition corresponding to the first self-discharge rate threshold is adjusted to obtain a new normal analysis result corresponding to the new second self-discharge rate. When the new normal analysis result shows the absence of discrete points, the adjustment of the standing condition is stopped, and finally the latest first self-discharge rate and the latest second self-discharge rate are obtained. Based on the latest first self-discharge rate, the latest first self-discharge rate threshold is obtained, thereby enabling a preliminary adjustment of the first self-discharge rate threshold. Subsequently, the correlation between the latest first self-discharge rate and the latest second self-discharge rate is analyzed. When the second correlation coefficient obtained from the analysis does not meet the preset correlation coefficient threshold, the first self-discharge rate threshold is further adjusted. The normal distribution analysis of the second self-discharge rate provides relatively accurate first and second self-discharge rates for the subsequent correlation analysis, so as to improve the accuracy of the second correlation coefficient, and further accurately adjust the first self-discharge rate threshold based on the second correlation coefficient.

[0085] In some embodiments of the present application, adjusting the first self-discharge rate threshold to obtain the second self-discharge rate threshold includes:

[0086] Lowering the first self-discharge rate threshold to obtain the second self-discharge rate threshold.

[0087] In this embodiment, when chemical self-discharge is not completely eliminated, the first self-discharge rate will be too large because chemical self-discharge and physical self-discharge are carried out simultaneously, which will cause the first self-discharge rate threshold to be higher than the ideal self-discharge rate threshold (the self-discharge rate threshold determined only during physical self-discharge). Therefore, the first self-discharge rate threshold can be lowered based on experience. The first self-discharge rate threshold can also be gradually adjusted according to a preset adjustment rule. For example, assuming that the standing time in the standing condition corresponding to the first self-discharge rate threshold is 48 hours, which is far different from the conventional standing time of 7 days for eliminating chemical self-discharge (the 7 days here is an assumed value, and the specific time varies according to the type of battery cell), a larger first self-discharge rate threshold decrease range is set. Assuming that the standing time is 5 days, it is less different from the conventional standing time for eliminating chemical self-discharge, so a smaller first self-discharge rate threshold decrease range is set. The specific decrease value of the first self-discharge rate threshold can be determined by data analysis, machine learning, etc. For example, after a large amount of battery test data is collected, the relationship between the first self-discharge rate threshold and chemical self-discharge is obtained through data analysis, and the specific decrease value of the first self-discharge rate threshold is determined based on the relationship between the first self-discharge rate threshold and chemical self-discharge. Alternatively, a model that can reflect the relationship between the first self-discharge rate threshold and chemical self-discharge is obtained by training with battery test data, and the specific decrease value of the first self-discharge rate threshold is predicted by using the model, which is not limited to this.

[0088] In some other embodiments of the present application, the stationary conditions corresponding to the first self-discharge rate threshold are adjusted, and a new first self-discharge rate is obtained after the stationary conditions are adjusted, and the second self-discharge rate threshold is calculated based on the new first self-discharge rate, wherein the stationary conditions include the stationary time, the stationary temperature, and the SOC of the battery cell. It should be understood that the stationary time is different from the first duration and the second duration. The battery cell is first stationary for a certain stationary time, and then for the first duration and the second duration. The stationary time here is a time specifically used to eliminate chemical self-discharge, and does not overlap with the first duration of the first self-discharge rate and the second duration of the second self-discharge rate obtained later. The stationary conditions are the stationary conditions of the battery cell in the stage of removing chemical self-discharge, which can be the same as or different from the temperature of the first self-discharge rate and the second self-discharge rate acquisition stage, and there is no limitation on this.

[0089] Since the chemical self-discharge elimination is not thorough enough, the first self-discharge rate threshold is not accurate enough. Therefore, the chemical self-discharge can be eliminated more thoroughly by adjusting the standing conditions corresponding to the first self-discharge rate threshold, so as to determine the second self-discharge rate threshold based on the new first self-discharge rate obtained after the standing conditions are adjusted. The specific adjustment methods can be to extend the standing time, increase the standing temperature, reduce the SOC of the battery cell, reduce the environmental humidity, etc. One or more of the above-mentioned various standing conditions can be adjusted, and no limitation is made thereto. After adjusting the standing conditions, the battery cell is left standing for the first duration according to the adjusted standing conditions, so as to obtain a new first self-discharge rate, and then the second self-discharge rate threshold is calculated based on the new first self-discharge rate.

[0090] The method for adjusting the self-discharge rate threshold of the battery cell provided in the embodiment of the present application can adjust the first self-discharge rate threshold by directly reducing the first self-discharge rate threshold, or can adjust the first self-discharge rate threshold by adjusting the standing conditions, so as to ensure the accuracy of the first self-discharge rate threshold.

[0091] In some embodiments of the present application, obtaining the first self-discharge rate of multiple battery cells and obtaining the second self-discharge rate of multiple battery cells includes:

[0092] Obtaining the first open-circuit voltage, the second open-circuit voltage, and the third open-circuit voltage of multiple battery cells at the first time point, the second time point, and the third time point respectively.

[0093] Wherein, the difference between the first time point and the second time point is the first duration, and the difference between the second time point and the third time point is the second duration.

[0094] The first self-discharge rate is calculated based on the first open-circuit voltage, the second open-circuit voltage, and the first duration, and the second self-discharge rate is calculated based on the second open-circuit voltage, the third open-circuit voltage, and the second duration.

[0095] That is, after the battery cell stands for the first duration, it continues to stand for the second duration, and the first self-discharge rate and the second self-discharge rate are calculated based on the open-circuit voltages measured at the first time point, the second time point, and the third time point. As a possible implementation manner, after the battery cell reaches the standing time t0, the battery cell stands for the first duration t1 and continues to stand for the second duration t2. The first time point is the time point when the standing time t0 is reached, the second time point is the time point when the first duration t1 is reached, and the third time point is the time point when the second duration t2 is reached. The first self-discharge rate The second self-discharge rate OCV1 is the first open-circuit voltage measured at the first time point, OCV2 is the second open-circuit voltage measured at the second time point, and OCV3 is the third open-circuit voltage measured at the third time point.

[0096] In some embodiments of the present application, the first self-discharge rate threshold is determined in the following manner:

[0097] Obtain the first mean and the first standard deviation of multiple first self-discharge rates, and determine the first discrete point based on the first mean, the first standard deviation, and the first standard deviation coefficient.

[0098] Conduct a positive verification on the battery cells corresponding to the first discrete point, and determine the first self-discharge rate threshold according to the verification result.

[0099] Conduct a normal distribution analysis on multiple second self-discharge rates to obtain a normal analysis result, including:

[0100] Obtain the second mean and the second standard deviation of multiple second self-discharge rates, and determine the normal analysis result based on the second mean, the second standard deviation, and the second standard deviation coefficient, where the normal analysis result is used to indicate whether there is a second discrete point, and the first standard deviation coefficient is greater than the second standard deviation coefficient.

[0101] As a possible implementation, calculate the first mean μ1 and the first standard deviation σ1 according to M first self-discharge rates K1, that is where M is the total number of K1, and K1m is the m-th K1. Determine the first discrete point among multiple first self-discharge rates according to the first mean μ1, the first standard deviation σ1, and the first standard deviation coefficient a1 (i.e., μ1 ± a1 * σ1). Conduct a positive verification on the battery cells corresponding to the first discrete point, that is, disassemble the battery cells corresponding to the first discrete point to confirm whether there is a real self-discharge problem. If there is a real self-discharge problem, then determine the first self-discharge rate threshold based on the corresponding first self-discharge rate.

[0102] Schematically, divide the numerical range interval of M first self-discharge rates K1, count the frequencies of M first self-discharge rates K1 in each range interval, and draw a histogram of the first self-discharge rate K1 as shown in Figure 3 Based on the range interval and the frequency, and determine the normal range (i.e., the numerical range covered between the black dashed lines in Figure 3 ) through the first mean μ1, the first standard deviation σ1, and the first standard deviation coefficient a1. If the first self-discharge rate K1 exceeds this normal range, then determine the first self-discharge rate K1 as a discrete point. In other embodiments of the present application, the first discrete point can also be determined based on other methods such as the Q-Q plot (Quantile-Quantile Plot) and P-P plot (Probability-Probability Plot) of M first self-discharge rates K1.

[0103] Calculate the second mean μ2 and the second standard deviation σ2 according to N second self-discharge rates K2, that is Wherein, N is the total number of K2, K2n is the nth K2. And according to the second mean μ2, the second standard deviation σ2 and the second standard deviation coefficient a2 (ie, μ2±a2*σ2), the second discrete point in the second self-discharge rate is determined, which can be based on Figure 2 The histogram shown determines the second discrete points.

[0104] The above-mentioned first standard deviation coefficient a1 and second standard deviation coefficient a2 can be 1, 2, 3, 3.5, 4, etc. In addition, considering that the first self-discharge rate determined based on short-term data may be affected by the joint influence of chemical self-discharge and physical self-discharge, resulting in large data fluctuations, when the first standard deviation coefficient a1 is small, more discrete points are screened, resulting in excessive disassembly verification and high cost. The second self-discharge rate determined based on long-term data mainly reflects physical self-discharge and the data is more stable. It is necessary to capture slight differences in the data by setting a smaller second standard deviation coefficient a2 to improve the sensitivity of the second discrete point screening. In summary, the set first standard deviation coefficient a1 is greater than the second standard deviation coefficient a2. Schematically, a1 is 4.5 and a2 is 3.

[0105] In addition, in the process of positive verification of the battery cell corresponding to the first discrete point, the first standard deviation coefficient a1 can be adjusted according to the probability that the battery cell really has a self-discharge problem shown by the verification result. For example, when the probability that the self-discharge problem really exists is low, the probability that the self-discharge problem really exists can be increased by increasing the first standard deviation coefficient a1, thereby speeding up the determination of the first self-discharge rate threshold.

[0106] In some embodiments of the present application, the present application further provides a method for adjusting a cell self-discharge rate threshold, the method comprising the following steps:

[0107] S201, under the condition of a static temperature of 45°C and a static time of 24-48h, multiple cells are chemically self-discharged and removed, and the cells are cooled at room temperature for 16-28h. At this time, the first open circuit voltage OCV1 at room temperature is measured, and the 24-48h and 16-28h before OCV1 are measured are both t0. The relationship between self-discharge and time is as follows Figure 4 As shown in FIG. 1 , chemical self-discharge is dominant in stage t0, and physical self-discharge is dominant in stages t1 and t2.

[0108] S202, after the battery cell is left to stand for a first period of time t1 (e.g., 24-72 hours at room temperature), a second open circuit voltage OCV2 is measured, and The first self-discharge rate K1 is calculated and analyzed. The normal distribution of the first self-discharge rate K1 is analyzed, and the first self-discharge rate threshold is determined according to the normal analysis result.

[0109] In this step, the first discrete points are determined according to the first mean value μ1, the first standard deviation σ1, and the first coefficient of standard deviation a1 (i.e., μ1±a1*σ1) of the first self-discharge rate K1. Schematically, the normal distribution of K1 is as shown in Figure 3 Figure Figure 3 . The cells corresponding to the first discrete points are subjected to positive verification, that is, the interfaces of the corresponding cells are disassembled to confirm whether there are actual self-discharge abnormal problems in the corresponding cells. When the positive verification results show that the cells indeed have abnormal self-discharge rates, the first self-discharge rate threshold is determined based on these cells.

[0110] S203, the cells are left standing for a second duration t2 (such as 1-2 months at room temperature), and the third open-circuit voltage OCV3 is measured after standing. The second self-discharge rate K2 is calculated according to Figure . A normal distribution analysis is performed on the second self-discharge rate K2 to determine whether there are discrete points in the second self-discharge rate K2. If there are discrete points, it is determined that the first self-discharge rate threshold is inaccurate, and the first self-discharge rate threshold needs to be adjusted. By continuously adjusting the standing conditions corresponding to the first self-discharge rate threshold, a new second self-discharge rate K2 is obtained, and further normal distribution analysis is performed on the new second self-discharge rate K2 until the normal analysis results show that there are no discrete points in the new second self-discharge rate K2. When there are no discrete points in the second self-discharge rate K2, step S204 is entered.

[0111] In this step, the second discrete points are determined according to the second mean value μ2, the second standard deviation σ2, and the second coefficient of standard deviation a2 (i.e., μ2±a2*σ2). Schematically, the normal distribution of K2 is as shown in Figure 2 Figure Figure 2 . After it is determined that there are second discrete points in the second self-discharge rate K2, the first self-discharge rate threshold is adjusted. The first self-discharge rate threshold can be adjusted by adjusting the standing conditions. Specifically, the standing time, standing temperature, SOC of the cells, etc. can be adjusted. After the standing conditions are adjusted, the cells are left standing for chemical self-discharge elimination, and then left standing for the first duration and the second duration to obtain a new first self-discharge rate and a new second self-discharge rate. A new normal distribution analysis is performed according to the new second self-discharge rate to obtain a new normal analysis result corresponding to the new second self-discharge rate. When the new normal analysis results show that there are no second discrete points, step S204 is entered.

[0112] S204, a correlation analysis is performed on the first self-discharge rate K1 and the second self-discharge rate K2. When the correlation coefficient between the first self-discharge rate K1 and the second self-discharge rate K2 is greater than or equal to the preset correlation coefficient threshold, it is determined that the first self-discharge rate threshold does not need to be adjusted. If the correlation coefficient is less than the preset correlation coefficient threshold, the first self-discharge rate threshold needs to be adjusted until the new correlation coefficient is greater than or equal to the preset correlation coefficient threshold. Finally, the second self-discharge rate threshold is obtained, and then step S205 is entered.

[0113] As a possible implementation, polynomial regression analysis is performed based on the obtained first self-discharge rate K1 and the second self-discharge rate K2 to determine the quadratic regression model of the first self-discharge rate K1 and the second self-discharge rate K2. Schematically, the polynomial regression analysis of K1 and K2 is as Figure 5 shown. Based on this quadratic regression model, the coefficient of determination R 2 (i.e., the correlation coefficient) is determined. This R 2 is used to measure the fitting degree of the quadratic regression model to the data K1 and K2. In some embodiments, when R 2 ≥0.7 (i.e., the correlation coefficient threshold), it is determined that there is a high correlation between the first self-discharge rate K1 and the second self-discharge rate K2. Conversely, the correlation between K1 and K2 is low. In other embodiments, the correlation coefficient threshold can also be set to 0.6, 0.75, 0.8, etc.

[0114] When the correlation between K1 and K2 is low, the static conditions can also be adjusted to obtain a new first self-discharge rate K1 and a new second self-discharge rate K2, and the correlation analysis is performed on the new first self-discharge rate K1 and the new second self-discharge rate K2 until the correlation between the new K1 and the new K2 is high, and then the final second self-discharge rate threshold is determined according to the latest first self-discharge rate K1.

[0115] In other embodiments of the present application, the second self-discharge rate threshold can also be obtained by reducing the first self-discharge rate threshold.

[0116] S205, screening abnormal battery cells based on the final second self-discharge rate threshold.

[0117] The method for adjusting the self-discharge rate threshold of a battery cell provided by the embodiments of the present application uses the second self-discharge rate to verify whether the first self-discharge rate threshold is accurate, and adjusts the first self-discharge rate threshold when the first self-discharge rate threshold is inaccurate, where the first self-discharge rate threshold is determined according to the first self-discharge rate. That is, the second self-discharge rate calculated based on long-term (i.e., the second duration) data is used to verify the first self-discharge rate threshold determined based on short-term (i.e., the first duration) data, and the first self-discharge rate threshold is adjusted according to the verification result to improve the accuracy of the self-discharge rate threshold, and further improve the accuracy of screening abnormal battery cells.

[0118] As Figure 6 shown, the embodiments of the present application also provide an apparatus for adjusting the self-discharge rate threshold of a battery cell. The apparatus includes an acquisition module 601 and an adjustment module 602.

[0119] Among them, the acquisition module 601 is configured to obtain the first self-discharge rate of multiple battery cells after the multiple battery cells are static for a first duration, and obtain the second self-discharge rate of the multiple battery cells after the multiple battery cells are static for a second duration, where the first duration is less than the second duration;

[0120] The adjustment module 602 is configured to adjust the first self-discharge rate threshold based on the second self-discharge rate to obtain a second self-discharge rate threshold, where the first self-discharge rate threshold is determined based on multiple first self-discharge rates.

[0121] In some embodiments of the present application, the adjustment module 602 is specifically configured to:

[0122] Perform a normal distribution analysis on multiple second self-discharge rates to obtain a normal analysis result;

[0123] When the normal analysis result indicates the presence of discrete points, adjust the first self-discharge rate threshold.

[0124] In some embodiments of the present application, the adjustment module 602 is specifically configured to:

[0125] Analyze the correlation between the first self-discharge rate and the second self-discharge rate, and when the obtained first correlation coefficient does not meet the preset correlation coefficient threshold, adjust the first self-discharge rate threshold.

[0126] In some embodiments of the present application, the adjustment module 602 is specifically configured to:

[0127] Perform a normal distribution analysis on multiple second self-discharge rates to obtain a normal analysis result;

[0128] When the normal analysis result indicates the presence of discrete points, adjust the static condition corresponding to the first self-discharge rate threshold to obtain a new normal analysis result corresponding to the new second self-discharge rate;

[0129] When the new normal analysis result indicates the absence of discrete points, obtain the new first self-discharge rate and the new second self-discharge rate of the multiple battery cells after the static condition is adjusted;

[0130] Analyze the correlation between the new first self-discharge rate and the new second self-discharge rate, and when the obtained second correlation coefficient does not meet the preset correlation coefficient threshold, adjust the first self-discharge rate threshold.

[0131] In some embodiments of the present application, the adjustment module 602 includes a first adjustment sub-module and a second adjustment sub-module.

[0132] Among them, the first adjustment sub-module is configured to reduce the first self-discharge rate threshold to obtain a second self-discharge rate threshold;

[0133] The first adjustment sub-module is used to adjust the rest conditions corresponding to the first self-discharge rate threshold, and obtain a new first self-discharge rate after the rest conditions are adjusted, and calculate a second self-discharge rate threshold based on the new first self-discharge rate, where the rest conditions include the rest time, the rest temperature, and the SOC of the battery cell.

[0134] In some embodiments of the present application, the device for adjusting the self-discharge rate threshold of the battery cell further includes a screening module.

[0135] The screening module is used to screen abnormal battery cells based on the second self-discharge rate threshold.

[0136] In some embodiments of the present application, the acquisition module 601 is specifically used for:

[0137] Obtain the first open-circuit voltage, the second open-circuit voltage, and the third open-circuit voltage of multiple battery cells at the first time point, the second time point, and the third time point respectively, where the difference between the first time point and the second time point is the first duration, and the difference between the second time point and the third time point is the second duration;

[0138] Calculate the first self-discharge rate based on the first open-circuit voltage, the second open-circuit voltage, and the first duration, and calculate the second self-discharge rate based on the second open-circuit voltage, the third open-circuit voltage, and the second duration.

[0139] In some embodiments of the present application, the first self-discharge rate threshold is determined in the following manner:

[0140] Obtain the first mean value and the first standard deviation of multiple first self-discharge rates, and determine the first discrete point based on the first mean value, the first standard deviation, and the first standard deviation coefficient;

[0141] Perform positive verification on the battery cells corresponding to the first discrete point, and determine the first self-discharge rate threshold according to the verification result;

[0142] Perform a normal distribution analysis on multiple second self-discharge rates to obtain a normal analysis result, including:

[0143] Obtain the second mean value and the second standard deviation of multiple second self-discharge rates, and determine the normal analysis result based on the second mean value, the second standard deviation, and the second standard deviation coefficient, where the normal analysis result is whether there is a second discrete point, and the first standard deviation coefficient is greater than the second standard deviation coefficient.

[0144] It can be understood that the adjustment device for the self-discharge rate threshold of the battery cell provided by the embodiments of the present application uses the second self-discharge rate to verify whether the first self-discharge rate threshold is accurate, and adjusts the first self-discharge rate threshold when the first self-discharge rate threshold is inaccurate, where the first self-discharge rate threshold is determined according to the first self-discharge rate. That is, the second self-discharge rate calculated based on long-term (i.e., the second duration) data is used to verify the first self-discharge rate threshold determined based on short-term (i.e., the first duration) data, and the first self-discharge rate threshold is adjusted according to the verification result to improve the accuracy of the self-discharge rate threshold, thereby improving the accuracy of abnormal battery cell screening.

[0145] Correspondingly, the embodiments of the present application also provide an electronic device. The electronic device includes a processor and a memory communicatively connected to the processor. The memory stores a computer program executable by the processor. When the computer program is executed by the processor, the processor can execute the method for adjusting the self-discharge rate threshold of the battery cell in the embodiments of the present application.

[0146] Correspondingly, the embodiments of the present application also provide a computer-readable storage medium. The computer-readable storage medium stores computer instructions for causing a processor to implement the method for adjusting the self-discharge rate threshold of the battery cell in the embodiments of the present application when executed.

[0147] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0148] The above has introduced in detail a method, device, equipment and medium for adjusting the self-discharge rate threshold of a battery cell provided by 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 adjusting the self-discharge rate threshold of an electric cell, characterized in that, Including: Obtaining a first self-discharge rate of the plurality of battery cells after the plurality of battery cells are static for a first duration, and obtaining a second self-discharge rate of the plurality of battery cells after the plurality of battery cells are static for a second duration, where the first duration is less than the second duration; Based on the second self-discharge rate, adjusting a first self-discharge rate threshold to obtain a second self-discharge rate threshold, where the first self-discharge rate threshold is determined based on a plurality of the first self-discharge rates.

2. The method for adjusting the self-discharge rate threshold of the battery cell according to claim 1, wherein The adjusting the first self-discharge rate threshold based on the second self-discharge rate includes: Performing a normal distribution analysis on the plurality of second self-discharge rates to obtain a normal analysis result; When the normal analysis result indicates the existence of discrete points, adjusting the first self-discharge rate threshold.

3. The method for adjusting the self-discharge rate threshold of an electric cell according to claim 1, wherein The adjusting the first self-discharge rate threshold based on the second self-discharge rate includes: Analyzing the correlation between the first self-discharge rate and the second self-discharge rate, and when a first correlation coefficient obtained from the analysis does not meet a preset correlation coefficient threshold, adjusting the first self-discharge rate threshold.

4. The method for adjusting the self-discharge rate threshold of the battery cell according to claim 1, wherein, The adjusting the first self-discharge rate threshold based on the second self-discharge rate includes: Performing a normal distribution analysis on the plurality of second self-discharge rates to obtain a normal analysis result; When the normal analysis result indicates the existence of discrete points, adjusting the static condition corresponding to the first self-discharge rate threshold to obtain a new normal analysis result corresponding to the new second self-discharge rate; When the new normal analysis result indicates the absence of discrete points, obtaining a new first self-discharge rate and a new second self-discharge rate of the plurality of battery cells after the static condition is adjusted; Analyzing the correlation between the new first self-discharge rate and the new second self-discharge rate, and when a second correlation coefficient obtained from the analysis does not meet a preset correlation coefficient threshold, adjusting the first self-discharge rate threshold.

5. The method for adjusting the self-discharge rate threshold of the battery cell according to any one of claims 2 to 4, characterized in that, The adjusting the first self-discharge rate threshold to obtain the second self-discharge rate threshold includes: Reducing the first self-discharge rate threshold to obtain the second self-discharge rate threshold; Or, adjusting the static condition corresponding to the first self-discharge rate threshold and obtaining a new first self-discharge rate after the static condition is adjusted, and calculating the second self-discharge rate threshold based on the new first self-discharge rate, where the static condition includes a static time, a static temperature, and the SOC of the battery cell.

6. The method for adjusting the self-discharge rate threshold of an electric cell according to claim 1, wherein After obtaining the second self-discharge rate threshold, the method further includes: Screening abnormal battery cells based on the second self-discharge rate threshold.

7. The method for adjusting the self-discharge rate threshold of an electric cell according to claim 1, wherein The obtaining the first self-discharge rate of the plurality of battery cells and the obtaining the second self-discharge rate of the plurality of battery cells include: Obtaining a first open-circuit voltage, a second open-circuit voltage, and a third open-circuit voltage of the plurality of battery cells at a first time point, a second time point, and a third time point respectively, where the difference between the first time point and the second time point is the first duration, and the difference between the second time point and the third time point is the second duration; The first self-discharge rate is calculated based on the first open-circuit voltage, the second open-circuit voltage, and the first duration, and the second self-discharge rate is calculated based on the second open-circuit voltage, the third open-circuit voltage, and the second duration.

8. The method for adjusting the self-discharge rate threshold of an electric cell according to claim 4, wherein The first self-discharge rate threshold is determined in the following manner: Obtain the first mean and the first standard deviation of the plurality of first self-discharge rates, and determine the first discrete point based on the first mean, the first standard deviation, and the first standard deviation coefficient; Perform positive verification on the battery cells corresponding to the first discrete point, and determine the first self-discharge rate threshold according to the verification result; Perform a normal distribution analysis on the plurality of second self-discharge rates to obtain a normal analysis result, including: Obtain the second mean and the second standard deviation of the plurality of second self-discharge rates, and determine the normal analysis result based on the second mean, the second standard deviation, and the second standard deviation coefficient, where the normal analysis result is used to indicate whether there is a second discrete point, and the first standard deviation coefficient is greater than the second standard deviation coefficient.

9. An adjustment device for the self-discharge rate threshold of an electric cell, characterized in that, Including: An acquisition module, configured to acquire the first self-discharge rates of the plurality of battery cells after the plurality of battery cells are static for the first duration, and acquire the second self-discharge rates of the plurality of battery cells after the plurality of battery cells are static for the second duration, where the first duration is less than the second duration; An adjustment module, configured to adjust the first self-discharge rate threshold based on the second self-discharge rate to obtain a second self-discharge rate threshold, where the first self-discharge rate threshold is determined based on the plurality of first self-discharge rates.

10. An electronic device, characterized in that, The electronic device includes: at least one processor; and a memory communicatively connected to the at least one processor; Wherein, the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the steps in the method for adjusting the self-discharge rate threshold of the battery cell according to any one of claims 1 to 8.

11. A computer-readable storage medium, characterized in that, A computer program is stored thereon, and the computer program is loaded by a processor to execute the steps in the method for adjusting the self-discharge rate threshold of the battery cell according to any one of claims 1 to 8.

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