A battery management system

Abstract

This invention provides a battery management system that stores a limit charging voltage table for battery cells. The limit charging voltage table includes temperature and the corresponding limit charging voltage. When charging a target battery cell, the system looks up the corresponding target limit charging voltage in the limit charging voltage table based on the current temperature, and then charges the target battery cell using the corresponding target limit charging voltage as the cutoff condition. Regardless of whether the target battery cell is continuously charged or regeneratively charged, this invention can reduce the risk of lithium plating caused by the actual charging current value being greater than the actual charging capacity of the battery cell due to the SOC deviation calculated by the BMS system, thereby improving the safety of battery cell use.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more specifically to a battery management system. Background Technology

[0002] In recent years, the new energy vehicle industry has developed rapidly. The key component of new energy vehicles is the power battery. The quality of the power battery has a significant impact on the vehicle's power performance and the driver's experience. For example, thermal runaway of the power battery can lead to spontaneous combustion of new energy vehicles.

[0003] When charging the power battery of a new energy vehicle, the BMS (Battery Management System) first calculates the actual state of charge (SOC) of the cell, and then finds a pre-set current value from the charging current meter that matches the actual SOC's charging capacity. If the BMS calculates or misjudges the SOC, the matched charging current will also be incorrect, resulting in an incorrect charging current being used. If the charging current exceeds the cell's actual charging capacity corresponding to the SOC, lithium plating will occur, ultimately leading to a short circuit within the cell, triggering thermal runaway, and potentially causing the new energy vehicle to spontaneously combust. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention is proposed. This invention provides a battery management system, comprising: a storage module for storing a limiting charging voltage meter; and a processing module that invokes the limiting charging voltage meter and searches the limiting charging voltage meter for a target limiting charging voltage corresponding to the current temperature of the target battery cell, so that during charging, the target limiting charging voltage serves as the charging cutoff condition.

[0005] In one embodiment of the present invention, the step of determining the limiting charging voltage meter includes: manufacturing a test cell; adjusting the state of charge (SOC) value of the test cell to a first preset SOC value, and placing the test cell at a target temperature to achieve thermal equilibrium, then charging the test cell with a preset continuous charging current to obtain a SOC curve of the test cell; finding a first full-cell voltage corresponding to a preset negative parameter potential margin value in the SOC curve; adjusting the SOC value of the test cell to a second preset SOC value, using the first full-cell voltage as a cutoff condition, charging the test cell with the preset continuous charging current to determine a first target full-cell voltage corresponding to the target temperature; adjusting the SOC value of the test cell to the second preset SOC value, then charging the test cell with a preset feedback charging current to determine a second target full-cell voltage corresponding to the target temperature; determining a limiting charging voltage corresponding to the target temperature based on the first target full-cell voltage and the second target full-cell voltage; and manufacturing the limiting charging voltage meter based on the limiting charging voltage corresponding to different target temperatures.

[0006] In one embodiment of the present invention, adjusting the state of charge (SOC) value of the test cell to a second preset SOC value, charging the test cell with the preset continuous charging current using the first full-cell voltage as a cutoff condition, and determining the first target full-cell voltage corresponding to the target temperature includes: adjusting the SOC value of the test cell to the second preset SOC value and placing the test cell at the target temperature to achieve thermal equilibrium; using the first full-cell voltage as a cutoff condition, performing constant current and constant voltage charging on the test cell with the preset continuous charging current, and obtaining the measured negative parameter potential of the test cell during the constant current and constant voltage charging process; during the constant current and constant voltage charging process, when the measured negative parameter potential of the test cell is... When the measured negative parameter potential is greater than or equal to the preset negative parameter potential margin value, the first full battery voltage is determined to be the first target full battery voltage corresponding to the target temperature. During the constant current and constant voltage charging process, when the measured negative parameter potential is less than the preset negative parameter potential margin value for the first time, the full battery voltage is reduced at least once using the first full battery voltage as the reference battery voltage, and the reduced full battery voltage is used as the cutoff condition. The test cell is then charged with constant current and constant voltage using the preset continuous charging current until the measured negative parameter potential of the test cell is greater than or equal to the preset negative parameter potential margin value. The full battery voltage corresponding to the measured negative parameter potential being greater than or equal to the preset negative parameter potential margin value is determined to be the first target full battery voltage corresponding to the target temperature.

[0007] In one embodiment of the present invention, the at least one reduction of the full battery voltage includes: a successive gradient reduction of the full battery voltage.

[0008] In one embodiment of the present invention, adjusting the state of charge (SOC) value of the test cell to the second preset SOC value, and performing constant current charging on the test cell with a preset feedback charging current to determine the second target full-cell voltage corresponding to the target temperature includes: adjusting the SOC value of the test cell to the second preset SOC value and placing the test cell at the target temperature to achieve thermal equilibrium; performing constant current charging on the test cell with a preset feedback charging current and obtaining the full-cell voltage at the end of the feedback charging process; when the full-cell voltage at the end of the feedback charging is greater than the first target full-cell voltage, determining the first target full-cell voltage as the second target full-cell voltage; when the full-cell voltage at the end of the feedback charging is less than or equal to the first target full-cell voltage, determining the full-cell voltage at the end of the feedback charging as the second target full-cell voltage.

[0009] In one embodiment of the present invention, before adjusting the state of charge (SOC) value of the test cell to a first preset SOC value, the step of determining the limiting charging voltage meter further includes: fabricating a continuous charging current meter and a feedback charging current meter based on the negative parameter potential margin value and the SOC curves of the test cell at different temperatures; wherein, the continuous charging current meter includes temperature, the SOC value of the test cell, and the corresponding continuous charging current; the feedback charging current meter includes temperature, the SOC value of the test cell, and the corresponding feedback charging current for a preset feedback time; matching a corresponding preset continuous charging current in the continuous charging current meter according to the first preset SOC value and the target temperature; and matching a corresponding preset feedback charging current in the feedback charging current meter according to the first preset SOC value and the target temperature.

[0010] In one embodiment of the present invention, before adjusting the state of charge value of the test cell to the first preset state of charge value, the step of determining the limiting charging voltage meter further includes: determining the limit negative parameter potential margin value for which the test cell does not undergo lithium plating; wherein, the preset negative parameter potential margin value is the limit negative parameter potential margin value.

[0011] In one embodiment of the present invention, determining the limiting charging voltage corresponding to the target temperature based on the first target full battery voltage and the second target full battery voltage includes: determining the minimum value among the first target full battery voltage and the second target full battery voltage as the limiting charging voltage corresponding to the target temperature.

[0012] In one embodiment of the present invention, the second preset state of charge value is 99% SOC.

[0013] In one embodiment of the present invention, the test cell is a three-electrode test cell.

[0014] This invention provides a battery management system, including a storage module and a processing module. The storage module stores a limit charging voltage table, which includes temperature and a corresponding limit charging voltage. Once a limit charging voltage table for a target battery cell is matched, the system can look up the corresponding target limit charging voltage in the limit charging voltage table based on the target cell's current temperature. Thus, the target limit charging voltage can be used as the cutoff condition for charging the battery cell. This invention pre-stores the limit charging voltage table in the battery management system, reducing the risk of lithium plating and thermal runaway during charging, thereby improving the safety of battery cell use. Attached Figure Description

[0015] The above and other objects, features, and advantages of the present invention will become more apparent from the more detailed description of the embodiments of the invention in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same parts or steps.

[0016] Figure 1 The diagram shown is a working block diagram of a battery management system provided by an exemplary embodiment of the present invention.

[0017] Figure 2 The diagram shown is a flowchart illustrating the steps of determining a limiting charging voltage meter according to another exemplary embodiment of the present invention.

[0018] Figure 3 The diagram shown is a flowchart illustrating the steps of determining a limiting charging voltage meter according to another exemplary embodiment of the present invention.

[0019] Figure 4 The diagram shown is a flowchart illustrating the steps of determining a limiting charging voltage meter according to another exemplary embodiment of the present invention.

[0020] Figure 5 The diagram shown is a flowchart illustrating the steps of determining a limiting charging voltage meter according to another exemplary embodiment of the present invention.

[0021] Figure 6 This is a structural block diagram of an electronic device provided in an exemplary embodiment of the present invention.

[0022] Figure 7 The diagram shows the structure of a three-electrode test cell. Detailed Implementation

[0023] In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. All directional indications (such as up, down, left, right, front, back, top, bottom, etc.) in the embodiments of this invention are only used to explain the relative positional relationships and movement of the components in a specific orientation (as shown in the accompanying drawings). If the specific orientation changes, the directional indication will also change accordingly. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0024] Furthermore, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0025] Exemplary System

[0026] As a first aspect of the present invention, the present invention provides a battery management system, such as... Figure 1 As shown, the battery management system 100 specifically includes:

[0027] Storage module 102 is used to store a limit charging voltage meter, which includes temperature and a limit charging voltage corresponding to the temperature.

[0028] Processing module 101 calls the limiting charging voltage table and searches for the target limiting charging voltage corresponding to the current temperature of the target cell in the limiting charging voltage table, so that the target limiting charging voltage is used as the charging cutoff condition during charging.

[0029] Specifically, the charging voltage limit refers to the highest voltage a battery can withstand during charging. When the battery voltage reaches this limit, the charging process switches to a constant voltage charging phase (i.e., current output stops), at which point the charging current gradually decreases until charging is complete. This ensures that the battery will not continue to be subjected to excessively high voltages after it is fully charged, thereby extending the battery's lifespan.

[0030] Specifically, the Battery Management System (BMS) stores limit charging voltage tables for multiple battery cells. Different cells use different electrode materials and / or different manufacturing methods (specifically, different cells can be distinguished by their model number). That is, each cell with different electrode materials or different manufacturing methods corresponds to a separate limit charging voltage table. The limit charging voltage table for a battery cell includes temperature and the corresponding limit charging voltage.

[0031] Specifically, the battery management system can query the limit charging voltage table that matches the battery cell in the storage module based on the battery cell (such as the cell model).

[0032] Once a limit charging voltage table matching the target cell is found, the corresponding target limit charging voltage can be found in the limit charging voltage table based on the current temperature of the target cell, so that the target limit charging voltage is used as the charging cutoff condition during charging.

[0033] This invention provides a battery management system, including a storage module and a processing module. The storage module stores a limit charging voltage table, which includes temperature and a corresponding limit charging voltage. Once the limit charging voltage table for a battery cell is matched, the system can look up the corresponding target limit charging voltage in the limit charging voltage table based on the current temperature of the target battery cell. Thus, the target battery cell can be charged using the target limit charging voltage as the cutoff condition. This invention pre-stores limit charging voltages in the battery management system, reducing the risk of lithium plating and thermal runaway during charging of the target battery cell, thereby improving the safety of battery cell use.

[0034] In one embodiment of the present invention, such as Figure 2 As shown, the steps for determining the limiting charging voltage meter specifically include the following steps:

[0035] S1: Adjust the state of charge (SOC) value of the test cell to the first preset SOC value, and place the test cell at the target temperature to reach thermal equilibrium. Then, charge the test cell with a preset continuous charging current to obtain the SOC curve of the test cell. Specifically, the test cell can be a lithium iron phosphate / graphite system cell.

[0036] First, a test cell is fabricated, comprising a positive electrode, a negative electrode, and a reference electrode. The test cell is then pre-treated to activate the reference electrode. Optionally, the test cell is a three-electrode test cell (see [link to relevant documentation]). Figure 7 (As shown).

[0037] Specifically, the first preset state of charge (SOC) value can be 0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90%. For example, if the first preset SOC value is 0%, then S1 means adjusting the SOC value of the tested cell to 0%.

[0038] The state of charge (SOC) of the test cell, whose reference electrode has been activated, is adjusted to a first preset SOC value, and then placed at multiple target temperatures to achieve thermal equilibrium. Achieving thermal equilibrium at the target temperatures means that the heat generated and dissipated within the test cell reaches a dynamic balance, ensuring a relatively stable internal temperature.

[0039] The target temperature is preset, and multiple target temperatures can follow a certain pattern. For example, the temperature difference between any two adjacent target temperatures is the same, such as a temperature difference of 10℃ between two adjacent target temperatures, or target temperatures of -20℃, -10℃, 0℃, 10℃, 20℃, 30℃, 40℃, and 50℃.

[0040] After the test cell reaches thermal equilibrium at each target temperature, the test cell that has reached thermal equilibrium at each target temperature is charged with a preset continuous charging current to 100% SOC to obtain the state of charge curve of the test cell at the target temperature.

[0041] Specifically, the preset continuous charging current can be found in the continuous charging current table of the test cell based on the target temperature and the first preset state of charge value. Continuous charging current refers to the current flowing continuously over a certain period of time, used to describe the current characteristics during battery charging. The continuous charging current table of the test cell is shown in Table 1 below.

[0042] Table 1: Continuous Charging Current of Test Cells

[0043]

[0044] Note: A2…H10 represent the charging current rate value.

[0045] For example, when the first preset state of charge (SOC) is 0% and the target temperature is -10℃, the corresponding preset continuous charging current is 0.2C. In this case, S1 is: adjust the SOC of the test cell to 0% and place the test cell at -10℃ to achieve thermal equilibrium, then charge the test cell at a constant current of 0.2C to obtain the SOC curve of the test cell.

[0046] S2: Find the first full cell voltage in the state of charge curve that corresponds to the preset negative parameter potential margin value;

[0047] During the charging process of the test cell, the positive parameter potential margin, negative parameter potential margin, and full battery voltage are monitored simultaneously. The full battery voltage during charging is displayed in the form of a state-of-charge curve. Therefore, once the preset negative parameter potential margin value is determined, the corresponding full battery voltage can be determined by searching the state-of-charge curve based on the monitoring time corresponding to the preset negative parameter potential margin value.

[0048] The preset negative parameter potential margin value is greater than or equal to the limiting negative parameter potential margin value V0 corresponding to the condition that lithium plating does not occur during charging of the test cell. The limiting negative parameter potential margin corresponding to the condition that lithium plating does not occur during charging of the test cell is determined empirically and calculated based on the redox potential of Li+ / Li as the reference point of 0.

[0049] Optionally, the preset negative parameter potential margin value is 0–30 mV vs Li+ / Li. Once the preset negative parameter potential margin value is determined, the first full cell voltage corresponding to the preset negative parameter potential margin value can be determined in the state of charge curve based on the detection time corresponding to the preset negative parameter potential margin value.

[0050] By using steps S1 and S2, the first full cell voltage corresponding to the absence of lithium plating during the charging process of the test cell to 100% SOC at each target temperature, starting from the first preset state of charge value.

[0051] S20: Using the first full battery voltage as the cutoff condition, the test cell is charged to full charge using a preset continuous charging current with constant current and constant voltage.

[0052] Once the first full-cell voltage corresponding to the condition that lithium plating does not occur during the charging process to 100% SOC at each target temperature using the first preset state of charge value as the charging starting point is determined, the first full-cell voltage can be used as the cutoff condition. By charging the test cell with a preset continuous charging current at a constant current and constant voltage, it can be ensured that the test cell is fully charged when the negative parameter potential reaches the limit negative parameter potential margin value V0 during the charging process.

[0053] S3: Adjust the state of charge value of the test cell to the second preset state of charge value, use the first full cell voltage as the cutoff condition, charge the test cell with a preset continuous charging current, and determine the first target full cell voltage corresponding to the target temperature.

[0054] In S20, the first full-cell voltage is used as the cutoff condition. After the test cell is charged to full capacity using a constant current and constant voltage charging current, the state of charge (SOC) of the test cell is adjusted to a second preset SOC value, for example, 99% SOC. Then, S3 is: adjust the SOC of the test cell to 99% SOC. After adjusting the SOC of the test cell to the second preset SOC value, it is placed at the target temperature to reach thermal equilibrium. Then, using the first full-cell voltage obtained in S1 corresponding to the absence of lithium plating as the cutoff condition, the test cell is charged with a preset continuous charging current (determined according to the target temperature and the first preset SOC value) to determine the first target full-cell voltage at the target temperature where lithium plating will not occur.

[0055] It should be noted that by executing S3 at each target temperature, the first target full cell voltage corresponding to each target temperature can be obtained. For example, when the target temperature is 20°C, after adjusting the second preset state of charge value, the first full cell voltage corresponding to 20°C is used as the cutoff condition when determining the first target full cell voltage corresponding to 20°C.

[0056] The test cell is charged with constant voltage and constant current using a preset continuous charging current (i.e., the current value corresponding to the first preset state of charge value). The first target full cell voltage is obtained by using the first full cell voltage as the cutoff condition. This ensures that the test cell can be fully charged when the negative parameter potential reaches the limit negative parameter potential margin value V0 corresponding to the time when lithium plating does not occur during the charging of the test cell.

[0057] For example, when the first preset state of charge (SOC) is 10% and the target temperature is -10℃, the corresponding preset continuous charging current can be found in Table 1 as B2, and the second preset SOC is 99% SOC. In this case, S3 is: adjust the SOC of the test cell to 99% SOC, and charge the test cell with the preset continuous charging current B2 at a constant current to determine the first target full battery voltage corresponding to -10℃ and 10% SOC.

[0058] S3 can be used to determine the first target full cell voltage that will not cause lithium plating when the test cell with the first preset state of charge value is continuously fully charged at the target temperature.

[0059] S4: Adjust the state of charge value of the test cell to the second preset state of charge value, and charge the test cell with a preset feedback charging current to determine the second target full cell voltage corresponding to the target temperature;

[0060] After S20, where the first full-cell voltage is used as the cutoff condition, the test cell is continuously charged to full capacity using a constant current and constant voltage. Then, the state of charge (SOC) of the test cell is adjusted back to a second preset SOC value, for example, 99% SOC. Therefore, S4 involves adjusting the SOC of the test cell to 99% SOC. After adjustment, once thermal equilibrium is reached at the target temperature, the test cell is continuously charged to 100% SOC using a preset feedback charging current to determine the second target full-cell voltage at the target temperature.

[0061] Specifically, the preset feedback charging current can be found in the feedback charging current table of the test cell based on the target temperature and the first preset state of charge (e.g., the first preset state of charge is 0% SOC). The feedback charging current table of the test cell is shown in Table 2 below.

[0062] Table 2: Test Cell Feedback Charging Current Table

[0063]

[0064] Note: a2-h10 represents the feedback charging current rate value for 10 seconds.

[0065] For example, when the first preset state of charge (SOC) is 10% and the target temperature is -10℃, the corresponding preset feedback charging current is b2, and the second preset SOC is 99%. In this case, S4 is: adjust the SOC of the test cell to 99% SOC, and use the preset feedback charging current b2 to charge the test cell at a constant current to determine the second target full battery voltage corresponding to -10℃ and 10% SOC; through S4, the second target full battery voltage corresponding to the test cell with the first preset SOC at the target temperature when fully charged by feedback charging can be determined.

[0066] S5: Determine the target temperature and the corresponding limiting charging voltage based on the first target full battery voltage and the second target full battery voltage.

[0067] Specifically, the limiting charging voltage can be the first target full battery voltage. When continuously charging the test cell, the first target full battery voltage is used as the charging cutoff condition, and lithium plating will not occur during the charging process.

[0068] Limiting the charging voltage can also be done using the second target full battery voltage. When the test cell is recharged, the second target full battery voltage is used as the charging cutoff condition, and lithium plating will not occur during the charging process.

[0069] Optionally, the limiting charging voltage can also be the minimum value between the first target full-cell voltage and the second target full-cell voltage. When the test cell is charged from the second state of charge starting point using the feedback charging current corresponding to the first state of charge value and the continuous charging current, respectively, the first target full-cell voltage and the second target full-cell voltage corresponding to the absence of lithium plating are determined. Then, the minimum value between the first target full-cell voltage and the second target full-cell voltage is selected as the limiting charging voltage corresponding to the target temperature. In this case, regardless of whether the test cell is continuously charged or regeneratively charged, as long as the minimum value between the first target full-cell voltage and the second target full-cell voltage (i.e., the limiting charging voltage) is used as the charging cutoff condition, the risk of lithium plating and thermal runaway of the test cell during charging can be reduced, regardless of whether it is regenerative charging or continuous charging.

[0070] By executing S1-S5 at each target temperature for the same preset state of charge (e.g., the first preset state of charge), the first target full cell voltage, the second target full cell voltage, and the limiting charging voltage corresponding to each target temperature can be obtained. These can be integrated into a first voltage correspondence table, as shown in Table 3 below. Table 3 shows the first target full cell voltage, the second target full cell voltage, and the limiting charging voltage corresponding to charging the test cell at different target temperatures.

[0071] Once the first voltage correspondence table is determined, the table can be selected based on the actual charging type when charging the test cell. For example, when continuously charging the test cell, the cutoff condition can be either the limiting charging voltage corresponding to the target temperature or the first target full-cell voltage. Similarly, when regenerative charging the test cell, the cutoff condition can be either the second target full-cell voltage corresponding to the target temperature or the limiting charging voltage.

[0072] Table 3:

[0073]

[0074] It should be noted that by performing S1-S5 on the same preset state of charge value (e.g., the first preset state of charge value) at each target temperature, the limiting charging voltage corresponding to each target temperature can be obtained. Then, a limiting charging voltage table corresponding to the test cell can be made, as shown in Table 4.

[0075] Table 4:

[0076]

[0077] Once the limiting charging voltage table is determined, when actually charging the target cell corresponding to the test cell, the corresponding limiting charging voltage can be selected from the limiting charging voltage table according to the current temperature of the target cell.

[0078] Once the limiting charging voltage is determined, it is stored in the BMS system. This allows the system to find the corresponding limiting charging voltage in the limiting charging voltage table based on the current temperature when charging the target cell. The target cell is then charged using the corresponding limiting charging voltage as the cutoff condition. Regardless of whether continuous charging or regenerative charging is used for the target cell, this reduces the risk of lithium plating and thermal runaway during the charging process, thereby improving the safety of the tested cell.

[0079] The steps for determining the limiting charging voltage provided by this invention are as follows: First, the state of charge (SOC) of the test cell is adjusted to a first preset SOC value. Then, the test cell is continuously charged using a preset continuous charging current corresponding to the target temperature and the first preset SOC value. During continuous charging, the positive parameter potential margin, negative parameter potential margin, and full cell voltage of the test cell are constantly monitored. The full cell voltage corresponding to the negative parameter potential reaching the limit negative parameter potential margin is taken as the first full cell voltage. Next, the SOC of the test cell is adjusted to a second preset SOC value, and the test cell is continuously charged using the first full cell voltage as the cutoff condition to obtain the first target full cell voltage without lithium plating. The SOC of the test cell is adjusted to the second preset SOC value again, and the test cell is recharged to obtain the second target full cell voltage without lithium plating. Finally, the minimum value between the first target full cell voltage and the second target full cell voltage is taken as the limiting charging voltage corresponding to the target temperature. This allows for the determination of limiting charging voltages for test cells at different temperatures, forming a limiting charging voltage table. This table is stored in the BMS system, so that when charging a target cell, the corresponding limiting charging voltage can be found in the table based on the current temperature. The target cell is then charged using the corresponding limiting charging voltage as the cutoff condition. Regardless of whether continuous charging or regenerative charging is used for the target cell, the risk of lithium plating and thermal runaway during charging can be reduced, thus improving the safety of the target cell in use.

[0080] like Figure 3 As shown, in one embodiment of the present invention, determining the first target full battery voltage during continuous charging corresponding to the target temperature, namely S3 (adjusting the state of charge value of the test cell to a second preset state of charge value, using the first full battery voltage as the cutoff condition, charging the test cell with a preset continuous charging current, and determining the first target full battery voltage corresponding to the target temperature), specifically includes the following steps:

[0081] S31: Adjust the state of charge (SOC) value of the test cell to the second preset SOC value, and place the test cell at the target temperature to achieve thermal equilibrium;

[0082] For example, if the second preset state of charge value is 99% SOC, then S31 is to adjust the state of charge value of the test cell to 99% SOC, and then place the test cell at the target temperature to achieve thermal equilibrium.

[0083] S32: Using the first full battery voltage as the cutoff condition, the test cell is charged with constant current and constant voltage using a preset continuous charging current; and the measured negative parameter potential of the test cell is obtained during the constant current and constant voltage charging process.

[0084] As described in S1 above, the preset continuous charging current can be found in the continuous charging current table of the test cell based on the target temperature and the first preset state of charge value (e.g., 0% SOC).

[0085] Using the first full-cell voltage determined in S2 as the charging cutoff condition, the test cell is charged with constant current and constant voltage using a preset continuous charging current, and the measured negative parameter potential of the test cell is detected at all times during the charging process.

[0086] S33: Determine whether the measured negative parameter potential of the test cell is greater than or equal to the preset negative parameter potential margin value;

[0087] If the judgment result of S33 is yes, that is, the measured negative parameter potential of the test cell is greater than or equal to the preset negative parameter potential margin value, then the first full cell voltage is used as the charging cutoff condition, and the test cell continues to be charged with constant current and constant voltage, while the measured negative parameter potential of the test cell is monitored, i.e., S32 is executed. After executing S32, S33 is executed. If the judgment result of S33 is still yes, then S32-S33 is executed. If the measured negative parameter potential of the test cell is still greater than or equal to the preset negative parameter potential margin value when the test cell is charged to 100% SOC, that is, when the measured negative parameter potential of the test cell is greater than or equal to the preset negative parameter potential margin value during the constant current and constant voltage charging process, then the first full cell voltage can be determined as the first target full cell voltage corresponding to the target temperature, i.e., S34.

[0088] If the judgment result of S33 is negative, that is, when the measured negative parameter potential of the test cell is lower than the preset negative parameter potential margin value for the first time, then if the test cell is continued to be charged with the first full cell voltage as the charging cutoff condition, lithium plating will occur. Therefore, the full cell voltage is reduced using the first full cell voltage as the reference cell voltage, and the reduced full cell voltage is used as the cutoff condition to perform constant current and constant voltage charging on the test cell with a preset continuous charging current, i.e., S35 is executed.

[0089] S34: Determine the first full cell voltage as the first target full cell voltage corresponding to the target temperature;

[0090] During constant current and constant voltage charging, if the measured negative parameter potential of the test cell is greater than or equal to the preset negative parameter potential margin value, it indicates that no lithium plating occurred in the test cell when charging with the first full cell voltage as the charging cutoff condition. Therefore, the first full cell voltage can be used as the first target full cell voltage corresponding to the target temperature.

[0091] S35: Reduce the full battery voltage and use the reduced full battery voltage as the cutoff condition to charge the test cell with a preset continuous charging current under constant current and constant voltage.

[0092] S36: Obtain the measured negative parameter potential of the test cell during constant current and constant voltage charging;

[0093] Using the first full-cell voltage as the reference voltage, the full-cell voltage is reduced, and the test cell is charged using the reduced full-cell voltage as the cutoff condition. While continuing to charge the test cell using the reduced full-cell voltage as the cutoff condition, the measured negative parameter potential of the test cell is constantly monitored during the charging process.

[0094] S37: Determine whether the measured negative parameter potential of the test cell is greater than or equal to the preset negative parameter potential margin value;

[0095] If the judgment result of S37 is yes, that is, the measured negative parameter potential of the test cell is greater than or equal to the preset negative parameter potential margin value, then the test cell is continuously charged with constant current and constant voltage using the reduced full battery voltage in S35 as the cutoff condition, and the measured negative parameter potential of the test cell is monitored during the charging process, that is, S36-S37 are executed. If the measured negative parameter potential of the test cell is still greater than or equal to the preset negative parameter potential margin value when the test cell is charged to 100% SOC, that is, when the measured negative parameter potential of the test cell is greater than or equal to the preset negative parameter potential margin value after the full battery voltage is reduced and then charged, then the reduced full battery voltage can be determined as the first target full battery voltage corresponding to the target temperature, that is, S38.

[0096] If the judgment result of S37 is negative, that is, the measured negative parameter potential of the test cell is still less than the preset negative parameter potential margin value, then the full battery voltage will continue to be reduced, and the reduced full battery voltage will be used as the cutoff condition. The test cell will be charged with constant current and constant voltage using the preset continuous charging current, that is, S35-S36 will be executed.

[0097] S38: The first target full cell voltage corresponding to the target temperature is the full cell voltage corresponding to the measured negative parameter potential being greater than or equal to the preset negative parameter potential margin value.

[0098] If, after the reduction of the full battery voltage is used as the charging cutoff condition, the measured negative parameter potential is always greater than or equal to the preset negative parameter potential margin value until the test cell is charged to 100% SOC, then the reduced full battery voltage is the first target full battery voltage corresponding to the target temperature.

[0099] In summary, if the measured negative parameter potential of the test cell is less than the preset negative parameter potential margin value for the first time, then S35-S38 will be executed until the test cell is fully charged, at which point the measured negative parameter potential of the test cell will be greater than or equal to the preset negative parameter potential margin value. The full cell voltage corresponding to the measured negative parameter potential being greater than or equal to the preset negative parameter potential margin value will then be the first target full cell voltage corresponding to the target temperature.

[0100] When charging the test cell with a continuous charging current, the measured negative parameter potential of the test cell is constantly monitored and compared with a preset negative parameter potential margin value. If the measured negative parameter potential is lower than the preset negative parameter potential margin value, the full-cell voltage of the test cell during charging is reduced until the measured negative parameter potential is lower than the preset negative parameter potential margin value. When reducing the battery voltage based on the first full-cell voltage, the reduction can be performed once or multiple times. When reducing the full-cell voltage multiple times, the voltage reduction value is the same each time, i.e., a gradient reduction of the first full-cell voltage, for example, the voltage reduction value can be 0.01V each time. This ensures that when continuously charging the test cell with the obtained first target full-cell voltage as the cutoff condition, lithium plating will not occur during the entire charging process.

[0101] For example, at a target temperature of 20℃, the first preset state of charge (SOC) is 0%, and the second preset SOC is 99%. According to Table 1 above, the corresponding preset continuous charging current is 1.2C. When charging the test cell at 1.2C, the first full-cell voltage (i.e., the full-cell voltage corresponding to a negative parameter potential greater than the preset negative parameter potential margin (i.e., 0MV)) is 3.51V. First, using 3.51V as the cutoff condition, the test cell is charged to full capacity using a constant current and constant voltage at 1.2C. Then, the SOC of the test cell is adjusted to the second preset SOC (99% SOC). When the test cell is charged again at 1.2C with 1% SOC remaining, if the measured negative parameter potential is <0mV, then the first full-cell voltage of 3.51V is reduced to 3.50V before charging the test cell again. Until the measured negative parameter potential is >0mV during charging, the corresponding new full-cell voltage will replace the first full-cell voltage set at 0% SOC charging. The whole process is a process of repeated comparison and iteration to ensure that the final full-cell charging cutoff condition can meet the requirement of negative parameter voltage >0mV.

[0102] In one embodiment of the present invention, such as Figure 4As shown, the specific method for determining the first target full battery voltage corresponding to the feedback charging at the target temperature, namely S4 (adjusting the state of charge value of the test cell to the second preset state of charge value, performing constant current charging on the test cell with the preset feedback charging current, and determining the target temperature and the corresponding second target full battery voltage), specifically includes the following steps:

[0103] S41: Adjust the state of charge (SOC) value of the test cell to the second preset SOC value, and place the test cell at the target temperature to achieve thermal equilibrium;

[0104] Specifically, the second preset state of charge (SOC) value can be 99%. After adjusting the SOC value of the test cell to the second preset value, the test cell is placed at the target temperature to reach thermal equilibrium.

[0105] S42: Perform constant current charging on the test cell with a preset feedback charging current, and obtain the full battery voltage at the end of the feedback charging process during constant current charging.

[0106] Specifically, the preset feedback charging current can be obtained from the feedback charging current table (as shown in Table 2 above) based on the first preset state of charge value and the target temperature.

[0107] Then, the test cell is charged with constant current using a preset feedback charging current, and the full battery voltage at the end of the feedback charging process is obtained in real time.

[0108] S43: Determine whether the full battery voltage at the end of the feedback charging is greater than the first target full battery voltage.

[0109] When the judgment result of S43 is yes, that is, the full battery voltage at the end of the feedback charging is greater than the first target full battery voltage, the first target full battery voltage can be determined as the second target full battery voltage corresponding to the target temperature, and S44 is executed.

[0110] When the judgment result of S43 is negative, that is, the full battery voltage at the end of the feedback charging is less than or equal to the first target full battery voltage, the user resigns and the full battery voltage at the end of the feedback charging can be determined as the second target full battery voltage corresponding to the target temperature, that is, S45 is executed.

[0111] S44: Determine the first target full cell voltage as the second target full cell voltage;

[0112] S45: Determine the full battery voltage at the end of the feedback charging as the second target full battery voltage.

[0113] In one embodiment of the present invention, such as Figure 5As shown, before S1 (adjusting the state of charge (SOC) value of the test cell to the first preset SOC value, placing the test cell at the target temperature to reach thermal equilibrium, and then charging the test cell with a preset continuous charging current to obtain the SOC curve of the test cell), the step of determining the limiting charging voltage meter also includes the following steps:

[0114] S10: Based on the negative parameter potential margin value and the state of charge curve of the test cell at different temperatures, make a continuous charging current meter and a feedback charging current meter; wherein, the continuous charging current meter includes temperature, the state of charge value of the test cell of the battery and the corresponding continuous charging current; the feedback charging current meter includes temperature, the state of charge value of the test cell of the battery and the corresponding feedback charging current at the preset feedback time.

[0115] S11: Match the corresponding preset continuous charging current in the continuous charging current table according to the first preset state of charge value and the target temperature.

[0116] S12: Match the corresponding preset feedback charging current in the feedback charging current table according to the first preset state of charge value and the target temperature.

[0117] In one embodiment of the present invention, before S1 (adjusting the state of charge (SOC) value of the test cell to a first preset SOC value, placing the test cell at a target temperature to achieve thermal equilibrium, and then charging the test cell with a preset continuous charging current to obtain the SOC curve of the test cell), the step of determining the limiting charging voltage meter further includes the following steps:

[0118] S13: Determine the limit of negative parameter potential margin for the test cell of the battery to prevent lithium plating;

[0119] Specifically, based on the design and manufacturing method of the test cell, the limiting negative parameter potential margin of 0mV Vs Li+ / Li is determined to prevent lithium plating during charging of the test cell.

[0120] The preset negative parameter potential margin value is the limit negative parameter potential margin value.

[0121] The present invention will be implemented in more detail below by illustrating specific embodiments to determine the steps of limiting the charging voltage meter.

[0122] Example 1:

[0123] S300: Determine the limit of negative parameter potential margin of 0mV Vs Li+ / Li for test cells of square aluminum-shell lithium iron phosphate / graphite system to prevent lithium plating.

[0124] S301: Based on the limit negative parameter potential margin, formulate the continuous charging current table corresponding to different state of charge values ​​of the test cell at different temperatures (as shown in Table 1 above) and the feedback charging current table (as shown in Table 2 above).

[0125] S302: After activating the lithium plating of the reference electrode of the test cell, adjust the state of charge (SOC) of the test cell to the first preset SOC value of 0% and place it at 10℃ for 3 hours to reach temperature equilibrium.

[0126] S303: In Table 1, the continuous charging current corresponding to the target temperature of 10℃ and the first preset state of charge value of 0% SOC is found to be 0.8C. The test cell is then charged at a constant current of 0.8C to 100% SOC to obtain the state of charge curve of the test cell.

[0127] S304: Find the full cell voltage corresponding to the limit negative parameter potential margin of 0mVVs Li+ / Li in the charge state curve of the test cell obtained in S400. This is the first full cell voltage.

[0128] S305: Using the first full-cell voltage as the cutoff condition, the test cell is charged to full charge at a constant current and constant voltage of 0.8C.

[0129] S306: Adjust the state of charge (SOC) of the test cell, which has been fully charged in S305, to 99%. Place the test cell at 10°C to achieve temperature equilibrium. Using the first full-cell voltage as the cutoff condition, charge the test cell at a constant current and constant voltage of 0.8C to fully charge the remaining 1% SOC. During charging, monitor the negative parameter potential in real time. If the measured negative parameter potential is <0mV, lower the first full-cell voltage and continue charging the test cell. Continue charging until the measured negative parameter potential is >0mV. The corresponding new full-cell voltage will then replace the first full-cell voltage. This process involves repeated comparisons and iterations to ensure that the final full-cell charging cutoff condition meets the requirement of a negative parameter voltage >0mV. Finally, obtain the first target full-cell voltage and record it.

[0130] S307: Find the feedback charging current corresponding to 10℃ and 0% SOC in Table 2 as 3C. Adjust the state of charge (SOC) of the test cell that has been fully charged by S306 to 99% SOC, and place the test cell at 10℃ to achieve temperature equilibrium. Perform constant current charging of the test cell at 3C to fully charge the remaining 1% SOC of the test cell, determine the second target full battery voltage corresponding to 10℃ and 0% SOC, and record it.

[0131] S308: Take the minimum value of the first target full cell voltage and the second target full cell voltage as the limiting charging voltage corresponding to 10℃ and 0% SOC.

[0132] The limiting charging voltage corresponding to continuous charging of the test cell at 10℃ can be obtained through S300-S308.

[0133] By charging the test cell through S300-S308 at different temperatures, the limiting charging voltage corresponding to different temperatures can be obtained;

[0134] S309: Create a limit charging voltage table based on the limit charging voltage corresponding to different target temperatures, as shown in Table 4 above.

[0135] The parameter that differs between Example 2 and Example 1 is that the first preset state of charge value is 10% SOC.

[0136] S400: Determine the limit of negative parameter potential margin of 0mV Vs Li+ / Li for test cells of square aluminum-cased lithium iron phosphate / graphite system to prevent lithium plating.

[0137] S401: Based on the limit negative parameter potential margin, formulate the continuous charging current table corresponding to different state of charge values ​​of the test cell at different temperatures (as shown in Table 1 above) and the feedback charging current table (as shown in Table 2 above).

[0138] S402: After activating the lithium plating of the reference electrode of the test cell, adjust the state of charge (SOC) of the test cell to the first preset SOC value of 10%, and place it at 10°C to achieve temperature equilibrium.

[0139] S403: Find the continuous charging current D2 corresponding to the target temperature of 10℃ and the first preset state of charge value of 10% SOC in Table 1, and use D2 to charge the test cell at a constant current to 100% SOC to obtain the state of charge curve of the test cell.

[0140] S404: Find the full cell voltage corresponding to the limit negative parameter potential margin of 0mVVs Li+ / Li in the charge state curve of the test cell obtained in S403. This is the first full cell voltage.

[0141] S405: Using the first full battery voltage as the cutoff condition, the test cell is charged to full charge using D2 with constant current and constant voltage.

[0142] S406: Adjust the state of charge (SOC) of the test cell, which has been fully charged in S405, to 99%. Place the test cell at 10°C to achieve temperature equilibrium. Using the first full-cell voltage as the cutoff condition, use D2 to charge the test cell with constant current and constant voltage until the remaining 1% SOC is fully charged. During charging, the negative parameter potential is monitored in real time. If the measured negative parameter potential is <0mV, the first full-cell voltage is lowered before charging the test cell again. This process continues until the measured negative parameter potential is >0mV during charging. The corresponding new full-cell voltage will then replace the first full-cell voltage. This entire process involves repeated comparisons and iterations to ensure that the final full-cell charging cutoff condition meets the requirement of a negative parameter voltage >0mV. The first target full-cell voltage is then obtained and recorded.

[0143] S407: Find the feedback charging current d2 corresponding to the target temperature of 10℃ and the first preset state of charge (SOC) of 10% in Table 2. Adjust the SOC of the test cell, which has been fully charged in S406, to 99% and place it at 10℃ to achieve temperature equilibrium. Perform constant current charging on the test cell using d2 to fully charge the remaining 1% SOC of the test cell, thereby determining the second target full battery voltage corresponding to 10℃ and 10% SOC, and record it.

[0144] S408: Take the minimum value of the first target full cell voltage and the second target full cell voltage as the limiting charging voltage corresponding to 10℃ and 10% SOC.

[0145] The limiting charging voltage corresponding to continuous charging of the test cell at 10℃ can be obtained through S400-S408.

[0146] By charging the test cell through S400-S408 at different temperatures, the corresponding limiting charging voltage for different temperatures can be obtained.

[0147] S409: Create a limit charging voltage meter based on the limit charging voltage corresponding to different target temperatures.

[0148] Figure 6 A block diagram of an electronic device according to an embodiment of the present invention is illustrated. Figure 6 As shown, the electronic device 10 includes one or more processors 11 and memory 12.

[0149] The processor 11 may be a central processing unit (CPU) or other form of processing unit with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device 10 to perform desired functions.

[0150] The memory 12 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 11 may execute the program instructions to implement the lithium plating detection method of the various embodiments of the present invention described above and / or other desired functions. Various contents such as input signals, signal components, and noise components may also be stored in the computer-readable storage medium.

[0151] In one example, the electronic device 10 may also include an input device 13 and an output device 14, which are interconnected via a bus system and / or other forms of connection mechanism (not shown).

[0152] When the electronic device 10 is a standalone device, the input device 13 can be a communication network connector for receiving the collected input signals from the first device and the second device.

[0153] In addition, the input device 13 may also include, for example, a keyboard, a mouse, etc.

[0154] The output device 14 can output various information to the outside, including determined distance information, direction information, etc. The output device 14 may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, etc.

[0155] Of course, for the sake of simplicity, Figure 6 Only some of the components of the electronic device 10 relevant to the present invention are shown, omitting components such as buses, input / output interfaces, etc. In addition, the electronic device 10 may include any other suitable components depending on the specific application.

[0156] The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of the present invention. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0157] The computer-readable storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may, for example, include, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0158] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the invention to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

Claims

1. A battery management system, characterized in that, include: Storage module, the storage module being used to store the limiting charging voltage meter; The processing module calls the limiting charging voltage table and searches for the target limiting charging voltage corresponding to the current temperature of the target cell in the limiting charging voltage table, so that the target limiting charging voltage is used as the charging cutoff condition during charging.

2. The battery management system according to claim 1, characterized in that, The step of determining the limiting charging voltage meter includes: Manufacturing and testing battery cells; The state of charge (SOC) value of the test cell is adjusted to the first preset SOC value, and the test cell is placed at the target temperature to reach thermal equilibrium. Then, the test cell is charged with a constant current using a preset continuous charging current to obtain the SOC curve of the test cell. Find the first full cell voltage corresponding to the preset negative parameter potential margin value in the state of charge curve; The state of charge (SOC) value of the test cell is adjusted to a second preset SOC value. The test cell is charged with the preset continuous charging current using the first full cell voltage as the cutoff condition, and the first target full cell voltage corresponding to the target temperature is determined. The state of charge (SOC) value of the test cell is adjusted to the second preset SOC value, and the test cell is charged with a constant current using a preset feedback charging current to determine the second target full cell voltage corresponding to the target temperature. Determine the limiting charging voltage corresponding to the target temperature based on the first target full battery voltage and the second target full battery voltage; The limiting charging voltage table is made according to the limiting charging voltage corresponding to different target temperatures.

3. The battery management system according to claim 2, characterized in that, Adjusting the state of charge (SOC) value of the test cell to a second preset SOC value, charging the test cell with the preset continuous charging current using the first full-cell voltage as a cutoff condition, and determining the first target full-cell voltage corresponding to the target temperature, includes: The state of charge (SOC) value of the test cell is adjusted to the second preset SOC value, and the test cell is placed at the target temperature to reach thermal equilibrium. Using the first full battery voltage as the cutoff condition, the test cell is charged with constant current and constant voltage using a preset continuous charging current, and the measured negative parameter potential of the test cell is obtained during the constant current and constant voltage charging process. During the constant current and constant voltage charging process, when the measured negative parameter potential of the test cell is greater than or equal to the preset negative parameter potential margin value, the first full cell voltage is determined to be the first target full cell voltage corresponding to the target temperature. During the constant current and constant voltage charging process, when the measured negative parameter potential is less than the preset negative parameter potential margin value for the first time, the full battery voltage is reduced at least once, using the first full battery voltage as the reference battery voltage. The reduced full battery voltage is used as the cutoff condition, and the test cell is charged with constant current and constant voltage using the preset continuous charging current until the measured negative parameter potential of the test cell is greater than or equal to the preset negative parameter potential margin value. The full battery voltage corresponding to the measured negative parameter potential being greater than or equal to the preset negative parameter potential margin value is determined as the first target full battery voltage corresponding to the target temperature.

4. The battery management system according to claim 3, characterized in that, The at least one reduction in full battery voltage includes: The full cell voltage is gradually reduced in a gradient manner.

5. The battery management system according to claim 3, characterized in that, Adjusting the state of charge (SOC) value of the test cell to the second preset SOC value, and performing constant current charging on the test cell with a preset feedback charging current to determine the second target full battery voltage corresponding to the target temperature, including: The state of charge (SOC) value of the test cell is adjusted to the second preset SOC value, and the test cell is placed at the target temperature to reach thermal equilibrium. The test cell is charged with a preset feedback charging current at a constant current, and the full battery voltage at the end of the feedback charging process is obtained. When the full battery voltage at the feedback charging terminal is greater than the first target full battery voltage, the first target full battery voltage is determined to be the second target full battery voltage; When the full battery voltage at the feedback charging terminal is less than or equal to the first target full battery voltage, the full battery voltage at the feedback charging terminal is determined to be the second target full battery voltage.

6. The battery management system according to claim 2, characterized in that, Before adjusting the state of charge (SOC) value of the test cell to the first preset SOC value, the step of determining the limiting charging voltage meter further includes: Based on the negative parameter potential margin value and the state of charge curve of the test cell at different temperatures, a continuous charging current meter and a feedback charging current meter are manufactured; wherein, the continuous charging current meter includes temperature, the state of charge value of the test cell and the corresponding continuous charging current; the feedback charging current meter includes temperature, the state of charge value of the test cell and the corresponding feedback charging current at a preset feedback time. Based on the first preset state of charge value and the target temperature, a corresponding preset continuous charging current is matched in the continuous charging current table. Based on the first preset state of charge value and the target temperature, a corresponding preset feedback charging current is matched in the feedback charging current table.

7. The battery management system according to claim 2, characterized in that, Before adjusting the state of charge (SOC) value of the test cell to the first preset SOC value, the step of determining the limiting charging voltage meter further includes: Determine the limiting negative parameter potential margin value at which the test cell will not undergo lithium plating; Wherein, the preset negative parameter potential margin value is the limit negative parameter potential margin value.

8. The battery management system according to claim 2, characterized in that, The step of determining the limiting charging voltage corresponding to the target temperature based on the first target full battery voltage and the second target full battery voltage includes: The minimum value between the first target full-cell voltage and the second target full-cell voltage is determined to be the limiting charging voltage corresponding to the target temperature.

9. The battery management system according to claim 2, characterized in that, The second preset state of charge value is 99% SOC.

10. The battery management system according to claim 2, characterized in that, The test cell is a three-electrode test cell.

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