Online detection method for lithium precipitation of battery

Abstract

The invention discloses a battery lithium precipitation on-line detection method, and relates to the technical field of charging lithium batteries, and the method comprises the steps: S1, in multiple charging processes of a to-be-detected battery, recording the first 20 charging processes as normal charging processes, and determining a preset voltage platform growth rate A; s2, after the normal charging process, selecting one charging process every 50-100 charging processes, extracting voltage data of all the selected charging processes, calculating a voltage platform of each selected charging process, and determining a voltage platform growth rate e of each selected charging process; and S3, calculating a ratio e / A of the voltage platform growth rate of each selected charging process to a preset voltage platform growth rate, and if e / A of a plurality of continuous selected charging processes exceeds the set ratio, judging that lithium precipitation occurs in the battery. Voltage data in the battery charging process is directly adopted, hardware cost does not need to be increased, data collection and judgment can be completed after charging is completed, and efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of rechargeable lithium batteries, and in particular to an online detection method for battery lithium deposition. Background Art

[0002] There is a risk of lithium deposition during overcharging or low-temperature charging of the battery. Battery lithium deposition will not only cause battery capacity decay and reduce the service life of the entire battery pack; the reaction of lithium dendrites with the electrolyte may also melt through the diaphragm, causing a local short circuit inside the battery, a rapid rise in battery temperature, and the battery or even the entire battery pack is at risk of thermal runaway. Although the battery management system can issue an alarm by monitoring rapid changes in battery temperature, this situation has already seriously threatened the safety of passengers and vehicles. Therefore, if the changes in battery lithium deposition can be monitored at an early stage, it will effectively reduce the risk of battery thermal runaway due to lithium deposition, which is of great significance to ensuring the safety of passengers and vehicles.

[0003] The conventional method to determine whether a battery has lithium deposition is to disassemble the battery cell. However, this method is costly and will damage the main body. It cannot be applied on a large scale. For other laboratory-level non-destructive testing methods, the required data cannot be obtained immediately in the battery replacement scenario, and additional testing equipment is required, which is costly.

[0004] A Chinese invention patent with publication number CN112776667A discloses a lithium plating detection method, which collects battery voltage data in a static state after charging at the vehicle end or battery swap station scenario, and calculates the voltage deviation at each moment based on the collected voltage data; when the calculated voltage deviation corresponding to a certain moment is greater than the voltage deviation at the previous moment, it triggers the calculation of the battery voltage change trend, and determines whether the battery is lithium plating based on the calculated voltage change trend. This patent requires additional data collection of the battery cell at rest after charging, which requires additional waiting time, affecting the battery swap efficiency.

[0005] Therefore, it is necessary to develop a method that directly uses the actual data of the battery charging process for lithium plating detection. The lithium plating detection can be completed after charging is completed, which is fast and efficient. Summary of the invention

[0006] The purpose of the present invention is to solve the shortcomings of the above-mentioned background technology and provide a method for directly using actual data from the battery charging process for lithium plating detection. The lithium plating detection can be completed after charging is completed, which is fast and efficient.

[0007] The technical solution of the present invention is: a battery lithium deposition online detection method, comprising:

[0008] S1. In the multiple charging processes completed by the battery to be tested, the first 20 to 50 charging processes are recorded as normal charging processes, the voltage data of the normal charging process in the preset SOC range is extracted, the voltage platform of the normal charging process is calculated, and the preset voltage platform growth rate A is determined;

[0009] S2. After the normal charging process, select a charging process every 50 to 100 charging processes, extract the voltage data of all selected charging processes within the preset SOC range, calculate the voltage platform of each selected charging process, and determine the voltage platform growth rate e of each selected charging process;

[0010] S3. Calculate the ratio e / A of the voltage platform growth rate of each selected charging process to the preset voltage platform growth rate. If the e / A of multiple consecutive selected charging processes exceeds the set ratio, it is determined that lithium deposition occurs in the battery.

[0011] In the above scheme, the voltage data of the charging process is used to determine the battery voltage platform under the current charging number at each preset charging number interval. Then, according to the charging number of the battery to be detected and the impedance corresponding to the battery to be detected, the voltage platform growth rate of the battery to be detected under each charging number is determined. Then, by comparing the voltage platform growth rate of the battery to be detected with the preset voltage platform growth rate A, the lithium deposition of the battery to be detected can be confirmed in situ online. And as the battery continues to age, if the lithium-ion battery does not undergo lithium deposition during use, there is an approximate linear relationship between the growth of the voltage platform and the number of charging times, but when the battery undergoes lithium deposition during use, the voltage platform will show abnormal growth. Therefore, by analyzing the changes in the voltage platform growth rate of the lithium-ion battery under each number of charging times, it is possible to accurately analyze whether the battery has lithium deposition.

[0012] Preferably, in step S1, determining the preset voltage platform growth rate A includes:

[0013] The voltage platform of the first normal charging process is taken as the preset reference a, and the average value of the voltage platforms of all normal charging processes is taken as b, and the preset voltage platform growth rate is calculated according to A=(ba) / a*100%.

[0014] In the above scheme, considering that even if the battery model is the same, the preset voltage platform growth rate A of the battery may be different, therefore, the voltage platform growth rate corresponding to 20 to 50 charges of the battery to be tested (when no lithium deposition occurs in the battery) is used as the preset voltage platform growth rate A, thereby improving the accuracy of the preset voltage platform growth rate A.

[0015] Preferably, in step S2, determining the voltage platform growth rate e of each selected charging process includes:

[0016] The growth rate of the voltage platform of each selected charging process is calculated according to e=(voltage platform of each selected charging process-a) / a*100%.

[0017] Preferably, in step S3, if e / A≥the set ratio for at least three consecutive selected charging processes, it is determined that lithium deposition occurs in the battery.

[0018] In the above scheme, it is considered that the voltage platform may increase abnormally at a certain number of charging times due to a certain accidental factor, and the abnormal increase of the voltage platform is not caused by the lithium deposition of the battery. Through multiple judgments, when the voltage platform growth rate of the battery in several consecutive charging times is greater than the preset growth rate of the battery, it is determined that the battery has lithium deposition, avoiding misjudgment and improving the accuracy of battery lithium deposition judgment.

[0019] Preferably, in step S3, the set ratio range is 5 to 10.

[0020] Preferably, in steps S1 and S2, calculating the voltage platform includes:

[0021] Multi-point sampling is performed within the preset SOC range to obtain the voltage corresponding to each SOC sampling point, and the voltage corresponding to all SOC sampling points is averaged to obtain a voltage platform to ensure that the charging current deviation of all SOC sampling points in the same charging process does not exceed the preset deviation range.

[0022] Furthermore, the voltages corresponding to the SOC sampling points are obtained by the following correction processing:

[0023] The ambient temperature of the first normal charging process is taken as the reference temperature T1, the ambient temperature of each charging process is taken as T2, and the starting voltage collected within the preset SOC range is taken as the reference voltage V0. The SOC sampling point of each charging process is used to correct the collected voltage V1 according to the following formula to obtain the voltage V2 of V1 at the reference temperature T1.

[0024]

[0025] Wherein, T1 is the set reference temperature, in °C;

[0026] V0 is the selected reference voltage, in V;

[0027] K is the temperature coefficient, the value range is 2*10 3 -5*10 3 ;

[0028] T2 is the ambient temperature during charging, in °C;

[0029] V1 is the actual collected voltage at the sampling point, in V;

[0030] V2 is the corrected voltage at the sampling point, in V.

[0031] In the above scheme, taking into account that in each usage cycle, due to differences in the working environment of the battery, etc., the temperature of the battery during the charging process will be different, the voltage V1 of the detected battery at temperature T2 is corrected by the above method, so that the output voltages are all the voltage platform V2 at the reference temperature T1, thereby improving the accuracy of the battery's voltage platform, thereby improving the accuracy of subsequent confirmation of lithium plating conditions.

[0032] Furthermore, the current preset deviation range of the same charging process is ≤5%.

[0033] Furthermore, the sampling frequency is 1 to 10 Hz in a preset SOC range.

[0034] Furthermore, the preset SOC range is m-n, then m≥10% SOC, n≤90% SOC and nm≥50% SOC. Steps S1 and S2 use the same preset SOC range.

[0035] Furthermore, the preset SOC range is 10-90% SOC or 20-90% SOC or 30-90% SOC, that is, m=10% SOC, n=90% SOC or m=20% SOC, n=90% SOC or m=30% SOC, n=90% SOC.

[0036] When lithium deposition occurs in the battery, the BMS can send out a safety warning signal to remind the user that the battery needs to be inspected.

[0037] The beneficial effects of the present invention are:

[0038] 1. The present invention directly uses the voltage data during the battery charging process, does not require additional hardware costs, and is pure software with zero cost. Data collection and judgment can be completed after charging is completed, thereby improving efficiency.

[0039] 2. The present invention selects the voltage platform data of the battery to be tested during its first 20 to 50 charging cycles (at this stage, the battery has not yet experienced lithium deposition, and it is a normal charging process) to determine the preset voltage platform growth rate A. The data feedback of the actual charging behavior can be used to be as close to the battery's own performance as possible, thereby improving the accuracy and applicability of the preset voltage platform growth rate A.

[0040] 3. The present invention can realize online and instant detection by comparing the real-time voltage platform growth rate e of the battery to be tested with the preset voltage platform growth rate A to confirm whether lithium deposition has occurred in the battery. This method is not only efficient and convenient, but also provides strong technical support for real-time monitoring and evaluation of battery health status.

[0041] 4. The present invention takes into account that the voltage platform may show abnormal growth at a certain number of charging times due to some accidental factors. Through multiple judgments, when the growth rate of the voltage platform of the battery in several consecutive charging times is greater than the preset growth rate of the battery, it is determined that the battery has lithium deposition, thereby avoiding misjudgment and improving the accuracy of battery lithium deposition judgment. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 Flow chart of the present invention DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention is described in detail in conjunction with the accompanying drawings and specific embodiments. Here, it should also be noted that in order to avoid obscuring the present invention due to unnecessary details, only the structures and / or processing steps closely related to the scheme of the present invention are shown in the accompanying drawings, and other details that are not closely related to the present invention are omitted. In addition, it should also be noted that the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0044] like Figure 1 As shown, the battery lithium deposition online detection method of the present invention is generally carried out in the following steps:

[0045] S1. In the multiple charging processes of the battery to be tested, the first 20 to 50 charging processes are recorded as normal charging processes, the voltage data of the normal charging process in the preset SOC range is extracted, the voltage platform of the normal charging process is calculated, and the preset voltage platform growth rate A is determined. The specific calculation process of A is as follows:

[0046] The voltage platform of the first normal charging process is taken as the preset reference a, and the average value of the voltage platforms of all normal charging processes is taken as b, and the preset voltage platform growth rate is calculated according to A=(ba) / a*100%.

[0047] S2. After the normal charging process, select a charging process every 50 to 100 charging processes (selected at equal intervals), extract the voltage data of all selected charging processes within the preset SOC range, calculate the voltage platform of each selected charging process, and determine the voltage platform growth rate e of each selected charging process;

[0048] Taking a as a reference, the growth rate of the voltage platform of each selected charging process is calculated according to e=(voltage platform of each selected charging process-a) / a*100%.

[0049] S3. Calculate the ratio e / A of the voltage platform growth rate of each selected charging process to the preset voltage platform growth rate. If the e / A of at least three consecutive selected charging processes exceeds the set ratio, it is determined that lithium deposition occurs in the battery. The set ratio is a number between 5 and 10.

[0050] The above methods for calculating the voltage platform of the normal charging process and selecting the voltage platform of the charging process are the same, which are: multi-point sampling (sampling frequency is 1-10 Hz) is performed within the same preset SOC range (the preset SOC range can be 10-90% SOC or 20-90% SOC or 30-90% SOC) to obtain the voltage corresponding to each SOC sampling point, and the voltage corresponding to all SOC sampling points is averaged to obtain the voltage platform, ensuring that the charging current deviation of all SOC sampling points does not exceed the preset deviation range (that is, the preset deviation range is ≤5%. If the deviation of the SOC sampling point exceeds the preset deviation range, the SOC sampling point is discarded and another sampling point is taken until all SOC sampling points meet the deviation requirements. The deviation is calculated according to the conventional method, and the charging current deviation of each sampling point = |current of each sampling point-average current of all sampling points| / average current of all sampling points*100%).

[0051] Since the temperature of the charging process may vary, the temperature of each SOC sampling point may be different. Therefore, the collected voltage is corrected to obtain the voltage of the reference temperature. The correction method is:

[0052] Taking the voltage at the starting sampling point within the preset SOC range as the reference voltage V0 and the charging temperature at the starting sampling point as the reference temperature T1, the voltage V1 at the charging temperature T2 is corrected according to the following formula to obtain the voltage platform V2 of V1 at the reference temperature T1.

[0053]

[0054] Wherein, T1 is the set reference temperature, in °C;

[0055] V0 is the set reference voltage, in V;

[0056] K is the temperature coefficient, the value range is 2*10 3 -5*10 3 ;

[0057] T2 is the actual charging temperature at the sampling point, in °C;

[0058] V1 is the actual collected voltage at the sampling point, in V;

[0059] V2 is the corrected voltage at the sampling point, in V.

[0060] In the embodiment of the present application, the battery model and material type are not specifically limited. For example, the positive electrode material can be lithium cobalt oxide, lithium nickel cobalt manganese oxide, and lithium iron phosphate. The following is a detailed description of the battery lithium deposition online detection method in combination with specific data. The unit of all voltage data below is V.

[0061] Example 1

[0062] The battery lithium deposition online detection method provided in this embodiment is performed according to the following steps:

[0063] S1. In the multiple charging processes completed by the battery to be tested (using 0.5C charging rate, battery type is NCM), the first 20 charging processes are recorded as normal charging processes, and the voltage data in the 10-90% SOC range of the normal charging process are extracted. The voltage platform of the normal charging process is calculated, and the preset voltage platform growth rate A is determined. The specific calculation process of A is as follows:

[0064] The voltage platform of the first normal charging process is taken as the preset reference a, and the average value of the voltage platforms of all normal charging processes is taken as b. Then, the preset voltage platform growth rate is calculated according to A=(ba) / a*100%. In this embodiment, a=3.2V, b=3.203V, and A=0.1%.

[0065] S2. After the normal charging process, one charging process is selected every 50 charging processes, and the voltage data of the selected charging process in the range of 10-90% SOC is extracted, and the voltage platform of each selected charging process is calculated to determine the voltage platform growth rate e of each selected charging process;

[0066] Taking a as a reference, the growth rate of the voltage platform of each selected charging process is calculated according to e=(voltage platform of each selected charging process-a) / a*100%.

[0067] S3. Calculate the ratio e / A of the voltage platform growth rate e of each selected charging process to the preset voltage platform growth rate A. The calculation results are shown in Table 1. If the e / A of at least three consecutive selected charging processes exceeds the set ratio, the set ratio is 5, that is, the e / A of at least three consecutive selected charging processes is ≥5, then it is determined that lithium deposition occurs in the battery.

[0068] Table 1 Growth rate e and e / A data

[0069]

[0070] It can be seen from Table 1 that the ratio e / A is less than 5. Therefore, it is judged that the battery of this embodiment is normal and no lithium deposition occurs.

[0071] The method for calculating the voltage platform of the normal charging process in step S1 and selecting the voltage platform of the charging process in step S2 is the same, which is: multi-point sampling is performed within the same preset 10-90% SOC range, and the sampling frequency is 10HZ to obtain the voltage corresponding to each SOC sampling point, and the voltage corresponding to all SOC sampling points is averaged to obtain the voltage platform, ensuring that the charging current deviation of all SOC sampling points in the same charging process is ≤5%. If the deviation of the SOC sampling point exceeds the preset deviation range, the SOC sampling point is discarded and another sampling point is taken until all SOC sampling points meet the deviation requirements.

[0072] Example 2

[0073] The battery lithium deposition online detection method provided in this embodiment is performed according to the following steps:

[0074] S1. In the multiple charging processes completed by the battery to be tested (using 1C rate charging, the battery type is NCM), the first 20 charging processes are recorded as normal charging processes, and the voltage data in the range of 20-90% SOC of the normal charging process are extracted. The voltage platform of the normal charging process is calculated (the calculation method is the same as that in Example 1), and the preset voltage platform growth rate A is determined. The specific calculation process of A is as follows:

[0075] The voltage platform of the first normal charging process is taken as the preset reference a, and the average value of the voltage platforms of the last 10 normal charging processes is taken as b. Then, the preset voltage platform growth rate is calculated according to A=(ba) / a*100%. In this embodiment, a=3.21V, b=3.2132V, and A=0.1%.

[0076] S2. After the normal charging process, one charging process is selected every 50 charging processes, and the voltage data of the selected charging process in the range of 20%-90% SOC is extracted, and the voltage platform of each selected charging process is calculated (the calculation method is the same as that in Example 1), and the voltage platform growth rate e of each selected charging process is determined;

[0077] Taking a as a reference, the growth rate of the voltage platform of each selected charging process is calculated according to e=(voltage platform of each selected charging process-a) / a*100%.

[0078] S3. Calculate the ratio e / A of the voltage platform growth rate of each selected charging process to the preset voltage platform growth rate. The calculation results are shown in Table 2. If e / A is ≥ 5 for at least three consecutive selected charging processes, it is determined that lithium deposition occurs in the battery.

[0079] Table 2 Growth rate e and e / A data

[0080]

[0081] It can be seen from Table 2 that starting from the 8th selected charging process, all e / A≥5, so this embodiment determines that lithium deposition occurs in the battery.

[0082] The method for calculating the voltage platform of the normal charging process in step S1 and selecting the voltage platform of the charging process in step S2 is the same, which is: multi-point sampling is performed within the same preset 20-90% SOC range, and the sampling frequency is 10HZ to obtain the voltage corresponding to each SOC sampling point, and the voltage corresponding to all SOC sampling points is averaged to obtain the voltage platform, ensuring that the charging current deviation of all SOC sampling points in the same charging process is ≤5%. If the deviation of the SOC sampling point exceeds the preset deviation range, the SOC sampling point is discarded and another sampling point is taken until all SOC sampling points meet the deviation requirements.

[0083] Example 3

[0084] The battery lithium deposition online detection method provided in this embodiment is performed according to the following steps:

[0085] S1. In the multiple charging processes completed by the battery to be tested (using 2C rate charging, the battery type is NCM), the first 20 charging processes are recorded as normal charging processes, and the voltage data in the range of 30-90% SOC of the normal charging process are extracted. The voltage platform of the normal charging process is calculated (the calculation method is the same as that in Example 1), and the preset voltage platform growth rate A is determined. The specific calculation process of A is as follows:

[0086] The voltage platform of the first normal charging process is taken as the preset reference a, and the average value of the voltage platforms of the last 10 normal charging processes is taken as b. The preset voltage platform growth rate is calculated according to A=(ba) / a*100%. In this embodiment, a=3.23V, b=3.23323V, and A=0.1%.

[0087] S2. After the normal charging process, one charging process is selected every 50 charging processes, and the voltage data of the selected charging process in the range of 30%-90% SOC is extracted, and the voltage platform of each selected charging process is calculated (the calculation method is the same as that in Example 1), and the voltage platform growth rate e of each selected charging process is determined;

[0088] Taking a as a reference, the growth rate of the voltage platform of each selected charging process is calculated according to e=(voltage platform of each selected charging process-a) / a*100%.

[0089] S3. Calculate the ratio e / A of the voltage platform growth rate of each selected charging process to the preset voltage platform growth rate. The calculation results are shown in Table 3. If e / A is ≥ 5 for at least 3 consecutive selected charging processes, it is determined that lithium deposition occurs in the battery.

[0090] Table 3 Growth rate e and e / A data

[0091]

[0092] It can be seen from Table 3 that starting from the fifth selected charging process, all e / A≥5, so this embodiment determines that lithium deposition occurs in the battery.

[0093] The above step S1 calculates the voltage platform of the normal charging process and the method for selecting the voltage platform of the charging process in step S2 is the same, both of which are: multi-point sampling is performed within the same preset 30-90% SOC range, the sampling frequency is 10HZ to obtain the voltage corresponding to each SOC sampling point, and the voltage corresponding to all SOC sampling points is averaged to obtain the voltage platform, ensuring that the charging current deviation of all SOC sampling points in the same charging process is ≤5%. If the deviation of the SOC sampling point exceeds the preset deviation range, the SOC sampling point is discarded and another sampling point is taken until all SOC sampling points meet the deviation requirements.

[0094] Since the ambient temperature during the charging process may vary, the temperature of each SOC sampling point may be different. Therefore, taking the first normal charging process as the benchmark, the voltage corresponding to the SOC sampling point during the charging process is obtained through the following correction processing:

[0095] The ambient temperature of the first normal charging process is taken as the reference temperature T1 (in this embodiment, T1 = 25°C), the ambient temperature of each charging process is taken as T2, and the starting voltage collected within the preset SOC range is taken as the reference voltage V0 (in this embodiment, V0 = 30% SOC starting voltage), K = 2*10 3 The SOC sampling point of each charging process is used to correct the collected voltage V1 (70% SOC sampling point) according to the following formula to obtain the voltage V2 of V1 at the reference temperature T1. The calculated data is shown in Table 4.

[0096]

[0097] Table 4

[0098]

[0099] From Table 4, it can be seen that V1=3.23V is corrected to obtain a voltage of 3.2349V at the reference temperature T1=25°C.

Claims

1. A battery lithium deposition online detection method, characterized in that: include: S1. In the multiple charging processes completed by the battery to be tested, the first 20 to 50 charging processes are recorded as normal charging processes, the voltage data of the normal charging process in the preset SOC range is extracted, the voltage platform of the normal charging process is calculated, and the preset voltage platform growth rate A is determined; S2. After the normal charging process, select a charging process every 50 to 100 charging processes, extract the voltage data of all selected charging processes within the preset SOC range, calculate the voltage platform of each selected charging process, and determine the voltage platform growth rate e of each selected charging process; S3. Calculate the ratio e / A of the voltage platform growth rate of each selected charging process to the preset voltage platform growth rate. If e / A of multiple consecutive selected charging processes is ≥ the set ratio, it is determined that lithium deposition occurs in the battery.

2. The battery lithium deposition online detection method according to claim 1, characterized in that: In step S1, determining the preset voltage platform growth rate A includes: The voltage platform of the first normal charging process is taken as the preset reference a, and the average value of the voltage platforms of all normal charging processes is taken as b, and the preset voltage platform growth rate is calculated according to A=(ba) / a*100%.

3. The battery lithium deposition online detection method according to claim 2, characterized in that: In step S2, determining the voltage platform growth rate e of each selected charging process includes: The growth rate of the voltage platform of each selected charging process is calculated according to e=(voltage platform of each selected charging process-a) / a*100%.

4. The battery lithium deposition online detection method according to claim 1, characterized in that: In step S3, if the e / A of at least three consecutive selected charging processes exceeds the set ratio, it is determined that lithium deposition occurs in the battery.

5. The battery lithium deposition online detection method according to claim 1, characterized in that: In step S3, the ratio range is set to 5-10.

6. The battery lithium deposition online detection method according to claim 1, characterized in that: In steps S1 and S2, calculating the voltage platform includes: Multi-point sampling is performed within the preset SOC range to obtain the voltage corresponding to each SOC sampling point, and the voltage corresponding to all SOC sampling points is averaged to obtain a voltage platform to ensure that the charging current deviation of all SOC sampling points in the same charging process does not exceed the preset deviation range.

7. The battery lithium deposition online detection method according to claim 6, characterized in that: The voltages corresponding to the SOC sampling points are obtained through the following corrections: The ambient temperature of the first normal charging process is taken as the reference temperature T1, the ambient temperature of each charging process is taken as T2, and the starting voltage collected within the preset SOC range is taken as the reference voltage V0. The SOC sampling point of each charging process is used to correct the collected voltage V1 according to the following formula to obtain the voltage V2 of V1 at the reference temperature T1. Wherein, T1 is the set reference temperature, in °C; V0 is the selected reference voltage, in V; K is the temperature coefficient, the value range is 2*10 3 -5*10 3 ; T2 is the ambient temperature during charging, in °C; V1 is the actual collected voltage at the sampling point, in V; V2 is the corrected voltage at the sampling point, in V.

8. The battery lithium deposition online detection method according to claim 6, characterized in that: The current preset deviation range of the same charging process is ≤5%.

9. The battery lithium deposition online detection method according to claim 6, characterized in that: The sampling frequency is 1 to 10 Hz in the preset SOC range.

10. The battery lithium deposition online detection method according to claim 6, characterized in that: The preset SOC range is m-n, wherein m≥10% SOC, n≤90% SOC and nm≥50% SOC.

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