Method and device for acquiring lithium precipitation boundary charging current of power battery

Abstract

The invention provides a method and a device for acquiring lithium precipitation boundary charging current of a power battery. The method comprises the following steps: establishing a battery model of a lithium ion battery based on a P2D theory; adding a negative electrode lithium precipitation equation for the battery model to obtain an initial charging model; calibrating the initial charging model to obtain a calibrated charging model; battery charging simulation is carried out based on a preset initial charging current and the calibrated charging model, and lithium precipitation-free charging current boundaries under different battery SOCs and environment temperatures are determined; obtaining all lithium precipitation-free charging current boundaries; and generating the charging current MAP of the non-lithium-precipitation boundary of the battery cell according to all the non-lithium-precipitation charging current boundaries. According to the method and device, the lithium precipitation boundary charging current curve of the power battery can be quickly obtained through battery charging simulation, the cost is low, and the accuracy is high.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a method and device for obtaining charging current at the lithium deposition boundary of a power battery. Background Art

[0002] In the field of power battery technology, especially under low temperature and high rate charging conditions, the stability and safety of battery performance have become crucial considerations. Specifically, power batteries are very prone to lithium deposition under the dual effects of low temperature environment and high rate charging. Lithium deposition not only causes a significant reduction in battery capacity, but also poses a serious threat to the thermal safety of the battery, increases the risk of thermal runaway of the battery, and thus seriously affects the service life and reliability of the power battery. The existing method for determining the charging rate of power batteries usually relies on three-electrode tests, which collect key parameters such as the negative electrode potential and temperature of the battery, and then determine the power battery lithium deposition boundary charging current curve based on these test results. However, it has been found in practice that the existing method can only determine the charging current under part of the SOC, and it is impossible to obtain a detailed power battery lithium deposition boundary charging current curve, and there are disadvantages such as long test time cycle, high cost, and inability to collect large amounts of data. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a method and device for obtaining the charging current of the lithium deposition boundary of a power battery, which can quickly obtain the charging current curve of the lithium deposition boundary of the power battery through battery charging simulation, with low cost and high accuracy.

[0004] The first aspect of the present application provides a method for obtaining a charging current at a lithium deposition boundary of a power battery, comprising:

[0005] Establish a battery model for lithium-ion batteries based on P2D theory;

[0006] Adding a negative electrode lithium deposition equation to the battery model to obtain an initial charging model;

[0007] Calibrate the initial charging model to obtain a calibrated charging model;

[0008] Performing battery charging simulation based on a preset initial charging current and the calibrated charging model to determine the lithium-free charging current boundary under different battery SOCs and ambient temperatures;

[0009] Get all the charging current boundaries without lithium deposition;

[0010] A charging current MAP of a cell without lithium deposition boundary is generated according to all the charging current boundaries without lithium deposition.

[0011] In the above implementation process, the method can quickly obtain the charging current curve of the lithium deposition boundary of the power battery through battery charging simulation, with low cost and high accuracy.

[0012] Furthermore, the calibrating the initial charging model to obtain a calibrated charging model includes:

[0013] Build a reference electrode battery test bench;

[0014] The reference electrode battery test bench is used to test the potentials under different charging curves to obtain test data;

[0015] The initial charging model is calibrated according to the test data to obtain a calibrated charging model.

[0016] Furthermore, the battery charging simulation is performed based on the preset initial charging current and the calibrated charging model to determine the lithium-free charging current boundary under different battery SOCs and ambient temperatures, including:

[0017] Determine the preset initial charging current as the current charging current;

[0018] Inputting the current charging current into the charging model through a current control module to charge the battery model;

[0019] detecting the negative electrode potential output by the charging model;

[0020] When the negative electrode potential is 0, obtaining the output current of the charging model;

[0021] Acquire the current battery SOC of the battery model and the ambient temperature corresponding to the battery model;

[0022] The output current is determined as a lithium-free charging current boundary under the current battery SOC and the ambient temperature.

[0023] Furthermore, the method further comprises:

[0024] When the current battery SOC does not reach the preset value, the current value of the output current is determined as the current charging current, and the current charging current is input into the charging model through the current control module to charge the battery model.

[0025] Furthermore, the method further comprises:

[0026] When the negative electrode potential is greater than 0, the current value of the current charging current is increased through the current control module, and the current charging current is input into the charging model through the current control module to charge the battery model.

[0027] Furthermore, the method further comprises:

[0028] When the negative electrode potential is less than 0, the current value of the current charging current is reduced through the current control module, and the current charging current is input into the charging model through the current control module to charge the battery model.

[0029] A second aspect of the present application provides a device for obtaining charging current at a lithium deposition boundary of a power battery, wherein the device for obtaining charging current at a lithium deposition boundary of a power battery comprises:

[0030] Establishing a unit for establishing a battery model of lithium-ion batteries based on P2D theory;

[0031] An adding unit is used to add a negative electrode lithium deposition equation to the battery model to obtain an initial charging model;

[0032] A calibration unit, used for calibrating the initial charging model to obtain a calibrated charging model;

[0033] A simulation unit, used to perform battery charging simulation based on a preset initial charging current and the calibrated charging model, and determine a lithium-free charging current boundary under different battery SOCs and ambient temperatures;

[0034] An acquisition unit, used for acquiring all non-lithium deposition charging current boundaries;

[0035] A generating unit is used to generate a charging current MAP of a cell without lithium deposition boundary according to all the charging current boundaries without lithium deposition.

[0036] Furthermore, the calibration unit includes:

[0037] Build subunits for building reference electrode battery test bench;

[0038] A test subunit, used to test the potential under different charging curves through the reference electrode battery test bench to obtain test data;

[0039] The calibration subunit is used to calibrate the initial charging model according to the test data to obtain a calibrated charging model.

[0040] Furthermore, the simulation unit comprises:

[0041] A first determining subunit, configured to determine a preset initial charging current as a current charging current;

[0042] An input subunit, used for inputting the current charging current into the charging model through a current control module to charge the battery model;

[0043] A detection subunit, used for detecting the negative electrode potential output by the charging model;

[0044] An acquisition subunit, used for acquiring an output current of the charging model when the negative electrode potential is 0;

[0045] The acquisition subunit is further used to acquire the current battery SOC of the battery model and the ambient temperature corresponding to the battery model;

[0046] The second determination subunit is used to determine the output current as a lithium-free charging current boundary under the current battery SOC and the ambient temperature.

[0047] Furthermore, the simulation unit also includes:

[0048] The circulation subunit is used to increase the current value of the current charging current through the current control module when the negative electrode potential is greater than 0, and trigger the input subunit to input the current charging current into the charging model through the current control module to charge the battery model.

[0049] Furthermore, the simulation unit also includes:

[0050] The circulation subunit is used to reduce the current value of the current charging current through the current control module when the negative electrode potential is less than 0, and trigger the input subunit to input the current charging current into the charging model through the current control module to charge the battery model.

[0051] In a third aspect, the present application provides an electronic device, including a memory and a processor, wherein the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to execute the method for obtaining the charging current at the lithium deposition boundary of a power battery as described in any one of the first aspects of the present application.

[0052] A fourth aspect of the present application provides a computer-readable storage medium storing computer program instructions, which, when read and executed by a processor, executes the method for obtaining the lithium deposition boundary charging current of the power battery described in any one of the first aspect of the present application.

[0053] The beneficial effects of the present application are as follows: the method and device can quickly obtain the lithium deposition boundary charging current curve of the power battery through battery charging simulation, with low cost and high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0055] Figure 1 A schematic flow chart of a method for obtaining charging current at the lithium deposition boundary of a power battery provided in an embodiment of the present application;

[0056] Figure 2 A schematic flow chart of another method for obtaining charging current at the lithium deposition boundary of a power battery provided in an embodiment of the present application;

[0057] Figure 3 A schematic diagram of an example of a method for obtaining a lithium deposition boundary charging current of a power battery provided in an embodiment of the present application;

[0058] Figure 4 A schematic diagram of the structure of a device for acquiring charging current at the lithium deposition boundary of a power battery provided in an embodiment of the present application;

[0059] Figure 5 A schematic diagram of the structure of another device for acquiring charging current at the lithium deposition boundary of a power battery provided in an embodiment of the present application. DETAILED DESCRIPTION

[0060] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0061] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0062] Example 1

[0063] Please see Figure 1 , Figure 1 A schematic flow chart of a method for obtaining a charging current at a lithium deposition boundary of a power battery provided in this embodiment. The method for obtaining a charging current at a lithium deposition boundary of a power battery includes:

[0064] S101. Establish a battery model for lithium-ion batteries based on P2D theory.

[0065] S102. Add a negative electrode lithium plating equation to the battery model to obtain an initial charging model.

[0066] In this embodiment, the method can establish a simulation model of a lithium-ion battery based on the P2D theory, and add a negative electrode lithium plating equation according to the side reactions occurring at the negative electrode when the battery cell is charged at a high rate.

[0067] In this embodiment, the method mainly considers the formation of SEI film and the "dead lithium" that cannot be re-oxidized during discharge due to loss of electrical contact, and completes the establishment of the initial charging model.

[0068] In this example, the key equations used in modeling are as follows:

[0069] (1) The reaction rates of the positive and negative electrode local reactions and the lithium deposition side reaction of the battery model all follow the BV equation:

[0070]

[0071] Exchange current density equation:

[0072]

[0073] Exchange current density of lithium precipitation reaction:

[0074]

[0075] Where α a，1 , α c，1 are the lithium ion insertion / extraction reaction exchange coefficients of the anode and cathode, η1 is the reaction overpotential, c e is the liquid phase lithium ion concentration, k1 is the lithium ion insertion / extraction reaction rate constant, k2 is the ion precipitation / dissolution reaction rate constant, c s，max is the maximum solid phase lithium ion concentration.

[0076] S103: Calibrate the initial charging model to obtain a calibrated charging model.

[0077] S104: Perform battery charging simulation based on a preset initial charging current and a calibrated charging model to determine a lithium-free charging current boundary under different battery SOCs and ambient temperatures.

[0078] S105, obtaining all the charging current boundaries without lithium deposition.

[0079] S106 , generating a charging current MAP for a cell without lithium deposition boundaries according to all charging current boundaries without lithium deposition.

[0080] In this embodiment, the execution subject of the method may be a computing device such as a computer or a server, and no limitation is made in this embodiment.

[0081] In this embodiment, the execution subject of the method may also be a smart device such as a smart phone, a tablet computer, etc., which is not limited in this embodiment.

[0082] It can be seen that the method for obtaining the lithium deposition boundary charging current of the power battery described in this embodiment can quickly obtain the lithium deposition boundary charging current curve of the power battery through battery charging simulation, with low cost and high accuracy.

[0083] Example 2

[0084] Please see Figure 2 , Figure 2 A schematic flow chart of a method for obtaining a charging current at a lithium deposition boundary of a power battery provided in this embodiment. The method for obtaining a charging current at a lithium deposition boundary of a power battery includes:

[0085] S201. Establish a battery model for lithium-ion batteries based on P2D theory.

[0086] S202. Add a negative electrode lithium plating equation to the battery model to obtain an initial charging model.

[0087] S203. Build a reference electrode battery test bench.

[0088] S204. Test the potentials under different charging curves using a reference electrode battery test bench to obtain test data.

[0089] S205 . Calibrate the initial charging model according to the test data to obtain a calibrated charging model.

[0090] In this embodiment, the method builds a reference electrode battery test bench, tests the potential under different charging curves, calibrates the initial charging model with the test data, and obtains a calibrated charging model.

[0091] S206: Determine the preset initial charging current as the current charging current.

[0092] S207. Input the current charging current into the charging model through the current control module to charge the battery model.

[0093] S208: Detect the negative electrode potential output by the charging model.

[0094] S209: When the negative electrode potential is 0, the output current of the charging model is obtained.

[0095] S210 : Obtain the current battery SOC of the battery model and the ambient temperature corresponding to the battery model.

[0096] S211, determining the output current as a lithium-free charging current boundary under the current battery SOC and ambient temperature.

[0097] As an optional implementation, the method further includes:

[0098] When the negative electrode potential is greater than 0, the current value of the current charging current is increased through the current control module, and the current charging current is input into the charging model through the current control module to charge the battery model.

[0099] As an optional implementation, the method further includes:

[0100] When the negative electrode potential is less than 0, the current value of the current charging current is reduced through the current control module, and the current charging current is input into the charging model through the current control module to charge the battery model.

[0101] S212, obtaining all the charging current boundaries without lithium deposition.

[0102] As an optional implementation, the method further includes:

[0103] When the current battery SOC reaches a preset value, step S212 is executed, where the preset value may be 100%, 90%, etc.

[0104] As an optional implementation, the method further includes:

[0105] When the current battery SOC mentioned above does not reach the preset value, the current value of the output current is determined as the current charging current, and step S207 is executed.

[0106] S213, generating a charging current MAP for a cell without lithium deposition boundaries according to all charging current boundaries without lithium deposition.

[0107] Please see Figure 3 , Figure 3 The present invention shows an example flow chart of a method for obtaining the charging current of the lithium precipitation boundary of a power battery. Among them, the method can be used to calibrate the charging model, give the initial charging current, and the model outputs the negative electrode potential. When the negative electrode potential is greater than zero, the charging current is increased through the current control module; if the negative electrode potential is less than zero, the charging current is reduced through the current control module. When the negative electrode potential is zero, the current I is output. The current I obtained at this time is the charging current boundary without lithium precipitation at the battery SOC and temperature at this moment. Then, this current I is used to charge the charging model, the battery model SOC increases, and the negative electrode potential value continues to be output. It is compared whether the negative electrode potential is equal to zero, and the charging current continues to be adjusted through the current control module.

[0108] In this embodiment, the execution subject of the method may be a computing device such as a computer or a server, and no limitation is made in this embodiment.

[0109] In this embodiment, the execution subject of the method may also be a smart device such as a smart phone, a tablet computer, etc., which is not limited in this embodiment.

[0110] It can be seen that the method for obtaining the lithium deposition boundary charging current of the power battery described in this embodiment can quickly obtain the lithium deposition boundary charging current curve of the power battery through battery charging simulation, with low cost and high accuracy.

[0111] Example 3

[0112] Please see Figure 4 , Figure 4 This is a schematic diagram of the structure of a device for acquiring charging current at the lithium deposition boundary of a power battery provided in this embodiment. Figure 4 As shown, the device for obtaining the charging current at the lithium deposition boundary of the power battery includes:

[0113] An establishing unit 310 is used to establish a battery model of a lithium-ion battery based on the P2D theory;

[0114] An adding unit 320 is used to add a negative electrode lithium deposition equation to the battery model to obtain an initial charging model;

[0115] A calibration unit 330, used to calibrate the initial charging model to obtain a calibrated charging model;

[0116] The simulation unit 340 is used to perform battery charging simulation based on a preset initial charging current and a calibrated charging model to determine a lithium-free charging current boundary under different battery SOCs and ambient temperatures;

[0117] An acquisition unit 350 is used to acquire all non-lithium deposition charging current boundaries;

[0118] The generating unit 360 is used to generate a charging current MAP of a cell without lithium deposition boundary according to all charging current boundaries without lithium deposition.

[0119] In this embodiment, the explanation of the device for obtaining the charging current at the lithium deposition boundary of the power battery can refer to the description in Embodiment 1 or Embodiment 2, which will not be described in detail in this embodiment.

[0120] It can be seen that the device for acquiring the lithium deposition boundary charging current of the power battery described in this embodiment can quickly acquire the lithium deposition boundary charging current curve of the power battery through battery charging simulation, with low cost and high accuracy.

[0121] Example 4

[0122] Please see Figure 5 , Figure 5 This is a schematic diagram of the structure of a device for acquiring charging current at the lithium deposition boundary of a power battery provided in this embodiment. Figure 5 As shown, the device for obtaining the charging current at the lithium deposition boundary of the power battery includes:

[0123] An establishing unit 310 is used to establish a battery model of a lithium-ion battery based on the P2D theory;

[0124] An adding unit 320 is used to add a negative electrode lithium deposition equation to the battery model to obtain an initial charging model;

[0125] A calibration unit 330, used to calibrate the initial charging model to obtain a calibrated charging model;

[0126] The simulation unit 340 is used to perform battery charging simulation based on a preset initial charging current and a calibrated charging model to determine a lithium-free charging current boundary under different battery SOCs and ambient temperatures;

[0127] An acquisition unit 350 is used to acquire all non-lithium deposition charging current boundaries;

[0128] The generating unit 360 is used to generate a charging current MAP of a cell without lithium deposition boundary according to all charging current boundaries without lithium deposition.

[0129] As an optional implementation, the calibration unit 330 includes:

[0130] Building subunit 331, for building a reference electrode battery test bench;

[0131] The test subunit 332 is used to test the potential under different charging curves through the reference electrode battery test bench to obtain test data;

[0132] The calibration subunit 333 is used to calibrate the initial charging model according to the test data to obtain a calibrated charging model.

[0133] As an optional implementation, the simulation unit 340 includes:

[0134] A first determining subunit 341 is used to determine a preset initial charging current as a current charging current;

[0135] An input subunit 342, used to input the current charging current into the charging model through the current control module to charge the battery model;

[0136] A detection subunit 343, used to detect the negative electrode potential output by the charging model;

[0137] An acquisition subunit 344 is used to acquire the output current of the charging model when the negative electrode potential is 0;

[0138] The acquisition subunit 344 is further used to acquire the current battery SOC of the battery model and the ambient temperature corresponding to the battery model;

[0139] The second determining subunit 345 is used to determine the output current as a lithium-free charging current boundary under the current battery SOC and ambient temperature.

[0140] As an optional implementation, the simulation unit 340 further includes:

[0141] The circulation subunit 346 is used to increase the current value of the current charging current through the current control module when the negative electrode potential is greater than 0, and trigger the input subunit 342 to input the current charging current into the charging model through the current control module to charge the battery model.

[0142] As an optional implementation, the simulation unit 340 further includes:

[0143] The circulation subunit 346 is used to reduce the current value of the current charging current through the current control module when the negative electrode potential is less than 0, and trigger the input subunit 342 to input the current charging current into the charging model through the current control module to charge the battery model.

[0144] In this embodiment, the explanation of the device for obtaining the charging current at the lithium deposition boundary of the power battery can refer to the description in Embodiment 1 or Embodiment 2, which will not be described in detail in this embodiment.

[0145] It can be seen that the device for acquiring the lithium deposition boundary charging current of the power battery described in this embodiment can quickly acquire the lithium deposition boundary charging current curve of the power battery through battery charging simulation, with low cost and high accuracy.

[0146] An embodiment of the present application provides an electronic device, including a memory and a processor, wherein the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to execute the method for obtaining the charging current at the lithium deposition boundary of a power battery in Embodiment 1 or Embodiment 2 of the present application.

[0147] An embodiment of the present application provides a computer-readable storage medium storing computer program instructions. When the computer program instructions are read and executed by a processor, the method for obtaining the lithium deposition boundary charging current of the power battery in Embodiment 1 or Embodiment 2 of the present application is executed.

[0148] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0149] In addition, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0150] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0151] The above description is only an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0152] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0153] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, 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 other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

Claims

1. A method for obtaining charging current at the lithium deposition boundary of a power battery, characterized in that: include: Establish a battery model for lithium-ion batteries based on P2D theory; Adding a negative electrode lithium deposition equation to the battery model to obtain an initial charging model; Calibrate the initial charging model to obtain a calibrated charging model; Performing battery charging simulation based on a preset initial charging current and the calibrated charging model to determine the lithium-free charging current boundary under different battery SOCs and ambient temperatures; Get all the charging current boundaries without lithium deposition; A charging current MAP of a cell without lithium deposition boundary is generated according to all the charging current boundaries without lithium deposition.

2. The method for obtaining the charging current at the lithium deposition boundary of a power battery according to claim 1, characterized in that: The step of calibrating the initial charging model to obtain a calibrated charging model includes: Build a reference electrode battery test bench; The reference electrode battery test bench is used to test the potentials under different charging curves to obtain test data; The initial charging model is calibrated according to the test data to obtain a calibrated charging model.

3. The method for obtaining the charging current at the lithium deposition boundary of a power battery according to claim 1, characterized in that: The battery charging simulation is performed based on the preset initial charging current and the calibrated charging model to determine the lithium-free charging current boundary under different battery SOCs and ambient temperatures, including: Determine the preset initial charging current as the current charging current; Inputting the current charging current into the charging model through a current control module to charge the battery model; detecting the negative electrode potential output by the charging model; When the negative electrode potential is 0, obtaining the output current of the charging model; Acquire the current battery SOC of the battery model and the ambient temperature corresponding to the battery model; The output current is determined as a lithium-free charging current boundary under the current battery SOC and the ambient temperature.

4. The method for obtaining the charging current at the lithium deposition boundary of a power battery according to claim 3, characterized in that: The method further comprises: When the negative electrode potential is greater than 0, the current value of the current charging current is increased through the current control module, and the current charging current is input into the charging model through the current control module to charge the battery model.

5. The method for obtaining the charging current at the lithium deposition boundary of a power battery according to claim 3, characterized in that: The method further comprises: When the negative electrode potential is less than 0, the current value of the current charging current is reduced through the current control module, and the current charging current is input into the charging model through the current control module to charge the battery model.

6. A device for obtaining charging current at the lithium deposition boundary of a power battery, characterized in that: The device for acquiring the charging current at the lithium deposition boundary of the power battery comprises: Establishing a unit for establishing a battery model of lithium-ion batteries based on P2D theory; An adding unit is used to add a negative electrode lithium deposition equation to the battery model to obtain an initial charging model; A calibration unit, used for calibrating the initial charging model to obtain a calibrated charging model; A simulation unit, used to perform battery charging simulation based on a preset initial charging current and the calibrated charging model, and determine a lithium-free charging current boundary under different battery SOCs and ambient temperatures; An acquisition unit, used for acquiring all non-lithium deposition charging current boundaries; A generating unit is used to generate a charging current MAP of a battery cell without lithium deposition boundary according to all the charging current boundaries without lithium deposition.

7. The device for acquiring charging current at the lithium deposition boundary of a power battery according to claim 6, characterized in that: The calibration unit comprises: Build subunits for building reference electrode battery test bench; A test subunit, used to test the potential under different charging curves through the reference electrode battery test bench to obtain test data; The calibration subunit is used to calibrate the initial charging model according to the test data to obtain a calibrated charging model.

8. The device for acquiring charging current at the lithium deposition boundary of a power battery according to claim 6, characterized in that: The simulation unit comprises: A first determining subunit, configured to determine a preset initial charging current as a current charging current; An input subunit, used for inputting the current charging current into the charging model through a current control module to charge the battery model; A detection subunit, used for detecting the negative electrode potential output by the charging model; An acquisition subunit, used for acquiring an output current of the charging model when the negative electrode potential is 0; The acquisition subunit is further used to acquire the current battery SOC of the battery model and the ambient temperature corresponding to the battery model; The second determination subunit is used to determine the output current as a lithium-free charging current boundary under the current battery SOC and the ambient temperature.

9. An electronic device, characterized in that: The electronic device comprises a memory and a processor, the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to execute the method for obtaining the charging current at the lithium deposition boundary of a power battery according to any one of claims 1 to 5.

10. A readable storage medium, characterized in that: The readable storage medium stores computer program instructions, and when the computer program instructions are read and executed by a processor, the method for obtaining the lithium deposition boundary charging current of a power battery according to any one of claims 1 to 5 is executed.

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