Method, device and equipment for evaluating continuous charging performance of lithium ion battery

Abstract

The invention discloses a method, a device and equipment for evaluating the continuous charging performance of a lithium ion battery, and relates to the technical field of power batteries. The method comprises the following steps: calculating the continuous charging performance of the lithium ion battery based on a negative electrode potential safety threshold line and a linear curve of negative electrode potentials and dynamic charging currents of a battery cell at different characteristic charge states at various target characteristic temperatures; determining the maximum charging current of the battery cell in different characteristic charge states at each target characteristic temperature; determining charging performance data of the battery cell based on the maximum charging current of the battery cell in different characteristic charge states at the target characteristic temperature of each temperature interval; and formulating a corresponding continuous charging MAP based on the charging performance data of the battery cell and a double-safety margin dynamic adjustment strategy, and evaluating and verifying the continuous charging performance of the lithium ion battery at the current temperature. Through the mode, the maximum charging current of the battery cell at different temperatures and different charge states is accurately determined, and the continuous charging MAP is formulated.

Description

Technical Field

[0001] The present application relates to the field of power battery technology, and in particular to a method, device and equipment for evaluating the continuous charging performance of a lithium-ion battery. Background Art

[0002] The lithium deposition phenomenon of lithium-ion batteries refers to the phenomenon that during the battery charging process, due to certain abnormal conditions, the lithium ions extracted from the positive electrode cannot be embedded in the negative electrode, thereby precipitating on the surface of the negative electrode to form a layer of metallic lithium. When lithium-ion batteries are charged at a high rate, the polarization effect is large. As the charging current increases, the negative electrode potential gradually decreases. When the negative electrode potential is lower than the lithium deposition potential, there is a risk of lithium deposition. Lithium deposition is an irreversible process, especially under low temperature conditions. Lithium dendrites are easily formed, piercing the diaphragm to cause a short circuit, and there are battery life attenuation and safety risks. Therefore, the evaluation of the continuous charging performance of lithium-ion batteries requires that the negative electrode potential of the battery cell is above the lithium deposition potential, and the maximum continuous charging current is determined to ensure the safety of the battery cell throughout its life cycle, thereby achieving safe and efficient operation of the battery.

[0003] In the prior art, there are few studies on methods for quickly evaluating the continuous charging current of lithium-ion batteries, and the evaluation of the continuous charging performance of lithium-ion batteries has problems such as many test conditions, long test cycles, and high test resources and labor costs.

[0004] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0005] The main purpose of this application is to provide a method, device and equipment for evaluating the continuous charging performance of lithium-ion batteries, aiming to solve the technical problems that the traditional methods of evaluating the continuous charging performance of lithium-ion batteries in the prior art are relatively complex, costly, and difficult to achieve quickly and accurately.

[0006] To achieve the above objectives, the present application provides a method for evaluating the continuous charging performance of a lithium-ion battery, the method comprising:

[0007] Dividing the operating temperature range of the battery cell in the lithium-ion battery into a plurality of temperature intervals, setting a plurality of characteristic temperatures in the temperature interval according to a preset temperature gradient, and setting a plurality of characteristic charge states in the charge state range according to a preset charge gradient, wherein the temperature interval includes at least a low temperature zone, a normal temperature zone, and a high temperature zone;

[0008] Select a target characteristic temperature from the temperature range, and determine the maximum charging current corresponding to different characteristic states of charge of the battery cell at each target characteristic temperature based on the negative electrode potential safety threshold line and the linear curves of the negative electrode potential and the dynamic charging current corresponding to different characteristic states of charge of the battery cell at each target characteristic temperature;

[0009] Determine the charging performance data of each temperature interval based on the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature of each temperature interval, wherein different strategies are used to determine the charging performance data for different temperature intervals;

[0010] Based on the charging performance data of each temperature range, determine the charging performance data of the battery cell within the operating temperature range;

[0011] Based on the charging performance data of the battery cell within the operating temperature range and based on the dual safety margin dynamic adjustment strategy, the corresponding continuous charging MAP is formulated to evaluate and verify the continuous charging performance of the lithium-ion battery at the current temperature.

[0012] In one embodiment, based on the negative electrode potential safety threshold line and the linear curves of the negative electrode potential and the dynamic charging current corresponding to different characteristic charge states of the battery cell at each target characteristic temperature, the step of determining the maximum charging current corresponding to different characteristic charge states of the battery cell at each target characteristic temperature includes:

[0013] Obtain the linear curves of negative electrode potential and dynamic charging current under different characteristic charge states at each target characteristic temperature;

[0014] Determine the intersection point between the negative electrode potential safety threshold line and each linear curve;

[0015] The charging current at the intersection of the battery cell corresponding to different characteristic charge states at each target characteristic temperature is taken as the maximum charging current.

[0016] In one embodiment, the step of obtaining linear curves of negative electrode potential and dynamic charging current corresponding to different characteristic charge states of the battery cell at each target characteristic temperature includes:

[0017] Discharging the battery cell to a first state of charge according to a preset discharge current;

[0018] Based on a dynamic current test strategy, a charging test is performed on the battery cell at different target characteristic temperatures to charge the battery cell to a second state of charge, wherein the dynamic current test strategy adopts a plurality of preset charging currents;

[0019] Based on the three-electrode strategy, the negative electrode potential data and battery voltage data of the battery cell during the charging test are recorded to generate the change curves of the negative electrode potential and the state of charge corresponding to each target characteristic temperature of the battery cell under different charging currents;

[0020] Based on the change curves of the negative electrode potential and the state of charge of the battery cell corresponding to each target characteristic temperature under different charging currents, the linear curves of the negative electrode potential and the dynamic charging current corresponding to different characteristic states of charge of the battery cell at each target characteristic temperature are determined.

[0021] In one embodiment, based on the change curves of the negative electrode potential and the state of charge of the battery cell corresponding to each target characteristic temperature under different charging currents, the step of determining the linear curves of the negative electrode potential and the dynamic charging current corresponding to different characteristic states of charge of the battery cell at each target characteristic temperature includes:

[0022] Based on the change curves of the negative electrode potential and the state of charge of the battery cell at each target characteristic temperature under different charging currents, the charging current data and the negative electrode potential data corresponding to different characteristic states of charge of the battery cell at each target characteristic temperature are determined, and valid linear data are screened out;

[0023] The effective linear data corresponding to different characteristic charge states of the battery cell at each target characteristic temperature are fitted to obtain the linear curves of the negative electrode potential and the charging current corresponding to different characteristic charge states of the battery cell at each target characteristic temperature.

[0024] In one embodiment, the target characteristic temperature in the normal temperature zone is all characteristic temperatures in the normal temperature zone, the target characteristic temperature in the low temperature zone is a preset number of characteristic temperatures selected from the low temperature zone, and the target characteristic temperature in the high temperature zone is all characteristic temperatures in the high temperature zone. Based on the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in each temperature interval, the step of determining the charging performance data in each temperature interval includes:

[0025] Determine the charging performance data in the normal temperature zone based on the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the normal temperature zone;

[0026] Based on the maximum charging current corresponding to different characteristic charge states of the battery cells at target characteristic temperatures in the normal temperature zone and the low temperature zone, a maximum charging current calculation model for the low temperature zone is fitted, and based on the maximum charging current calculation model, the charging performance data for the low temperature zone is determined;

[0027] Based on the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone, the maximum safe charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone is determined, and based on the maximum safe charging current, the charging performance data for the high temperature zone is generated.

[0028] In one embodiment, based on the maximum charging current corresponding to different characteristic states of charge of the battery cell at the target characteristic temperature in the high temperature zone, the step of determining the maximum safe charging current corresponding to different characteristic states of charge of the battery cell at the target characteristic temperature in the high temperature zone includes:

[0029] Obtain the maximum charging current with temperature rise corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone;

[0030] Based on the maximum charging current corresponding to different characteristic states of charge at the target characteristic temperature of the battery cell in the normal temperature zone, the upper limit of the current in the normal temperature zone corresponding to the different characteristic states of charge is determined, and based on the upper limit of the current in the normal temperature zone corresponding to the different characteristic states of charge, the maximum charging current corresponding to different characteristic states of charge at the target characteristic temperature of the battery cell in the high temperature zone is adjusted;

[0031] Based on the principle of safety first, the current with the smallest value is determined from the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone and the maximum charging current with temperature rise as the maximum safe charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone.

[0032] In one embodiment, the step of obtaining the maximum charging current with temperature rise corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone includes:

[0033] Obtain the corresponding relationship between the specific heat capacity of the battery cell, the mass of the battery cell, the temperature difference, the dynamic internal resistance of the battery cell and the maximum charging current with temperature rise;

[0034] Based on the specific heat capacity of the battery cell, the battery cell mass, the dynamic internal resistance of the battery cell, the temperature difference between the target characteristic temperature in the high temperature zone and the upper limit of the operating temperature, and the corresponding relationship, the maximum charging current corresponding to the temperature rise of the battery cell at different characteristic charge states at the target characteristic temperature in the high temperature zone is determined.

[0035] In one embodiment, based on the charging performance data of the battery cell within the operating temperature range and based on the dual safety margin dynamic adjustment strategy, a corresponding continuous charging MAP is formulated, and the steps of evaluating and verifying the continuous charging performance of the lithium-ion battery at the current temperature include:

[0036] Get the current state of charge and current temperature;

[0037] When the current state of charge is less than the preset boundary state of charge, the target temperature is determined according to the current temperature and the temperature safety margin, and the temperature safety margin is determined according to the temperature safety factor and the preset temperature gradient;

[0038] Determine the target state of charge according to the current state of charge and the state of charge safety margin, the state of charge safety margin is determined according to the state of charge safety factor and the preset charge gradient;

[0039] Based on the target temperature and the target state of charge, determining a corresponding target maximum charging current in the charging performance data;

[0040] Generates a continuous charge MAP for the current temperature based on the target maximum charge current.

[0041] In addition, to achieve the above-mentioned purpose, the present application also proposes a device for evaluating the continuous charging performance of a lithium-ion battery, and the device for evaluating the continuous charging performance of a lithium-ion battery comprises:

[0042] A parameter division module, for dividing the operating temperature range of the battery cell in the lithium-ion battery into a plurality of temperature intervals, setting a plurality of characteristic temperatures in the temperature interval according to a preset temperature gradient, and setting a plurality of characteristic charge states in the charge state range according to a preset charge gradient, wherein the temperature interval includes at least a low temperature zone, a normal temperature zone, and a high temperature zone;

[0043] A data calculation module is used to select a target characteristic temperature from the temperature range, and determine the maximum charging current corresponding to different characteristic charge states of the battery cell at each target characteristic temperature based on the negative electrode potential safety threshold line and the linear curves of the negative electrode potential and the dynamic charging current corresponding to different characteristic charge states of the battery cell at each target characteristic temperature;

[0044] The data calculation module is further used to determine the charging performance data of each temperature interval based on the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature of each temperature interval, wherein different strategies are used to determine the charging performance data for different temperature intervals;

[0045] The data calculation module is also used to determine the charging performance data of the battery cell within the operating temperature range based on the charging performance data of each temperature range;

[0046] The performance evaluation module is used to formulate the corresponding continuous charging MAP based on the charging performance data of the battery cell within the operating temperature range and the dual safety margin dynamic adjustment strategy, and to evaluate and verify the continuous charging performance of the lithium-ion battery at the current temperature.

[0047] In addition, to achieve the above-mentioned purpose, the present application also proposes a device for evaluating the continuous charging performance of a lithium-ion battery. The device for evaluating the continuous charging performance of a lithium-ion battery includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. The computer program is configured to implement the steps of the method for evaluating the continuous charging performance of a lithium-ion battery as described above.

[0048] In addition, to achieve the above-mentioned purpose, the present invention also proposes a storage medium, which is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, the steps of the method for evaluating the continuous charging performance of a lithium-ion battery as described above are implemented.

[0049] In addition, to achieve the above-mentioned purpose, the present application also provides a computer program product, which includes a computer program, and when the computer program is executed by a processor, the steps of the method for evaluating the continuous charging performance of a lithium-ion battery as described above are implemented.

[0050] The present application provides a method for evaluating the continuous charging performance of a lithium-ion battery, which divides the operating temperature range of a battery cell in the lithium-ion battery into multiple temperature intervals, sets multiple characteristic temperatures in the temperature interval according to a preset temperature gradient, and sets multiple characteristic charge states in the charge state range according to a preset charge gradient, wherein the temperature interval at least includes a low temperature zone, a normal temperature zone, and a high temperature zone; selects a target characteristic temperature from the temperature interval, and determines the maximum charging current corresponding to the different characteristic charge states of the battery cell at each target characteristic temperature based on a negative electrode potential safety threshold line and a linear curve of the negative electrode potential and the dynamic charging current corresponding to different characteristic charge states of the battery cell at each target characteristic temperature; determines the charging performance data of each temperature interval based on the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature of each temperature interval, wherein different strategies are used to determine the charging performance data for different temperature intervals; determines the charging performance data of the battery cell within the operating temperature range based on the charging performance data of each temperature interval; formulates a corresponding continuous charging MAP based on the charging performance data of the battery cell within the operating temperature range and based on a dual safety margin dynamic adjustment strategy, and evaluates and verifies the continuous charging performance of the lithium-ion battery at the current temperature. The present application combines the dynamic current method and the three-electrode method at different temperatures and different states of charge to obtain a linear curve of the negative electrode potential and the dynamic charging current, and sets a negative electrode potential safety threshold line for the lithium plating potential. The intersection of the linear curve and the negative electrode potential safety threshold line is used to determine the maximum charging current of the battery cell at different temperatures and different states of charge, and the maximum continuous charging capacity of the battery cell is quickly and accurately evaluated. At the same time, based on the maximum continuous charging capacity of the battery cell, a continuous charging strategy and a charging MAP of the battery cell are formulated to ensure the safety of the battery cell throughout its life cycle, and to achieve safe and efficient operation of the power battery, thereby solving the technical problems that the traditional method of evaluating the continuous charging performance of lithium-ion batteries is relatively complex, costly, and difficult to achieve quickly and accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0052] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0053] Figure 1 This is a flow chart of Embodiment 1 of the method for evaluating the continuous charging performance of a lithium-ion battery of the present application;

[0054] Figure 2 A schematic diagram of a negative electrode potential change curve of a method for evaluating continuous charging performance of a lithium-ion battery provided in Example 1 of the present application;

[0055] Figure 3 A schematic diagram of linear curve fitting of a method for evaluating continuous charging performance of a lithium-ion battery provided in Example 1 of the present application;

[0056] Figure 4 A schematic diagram of a maximum current fitting curve in a low temperature region of a method for evaluating the continuous charging performance of a lithium-ion battery provided in Example 1 of the present application;

[0057] Figure 5 This is a flow chart of Embodiment 2 of the method for evaluating the continuous charging performance of a lithium-ion battery of the present application;

[0058] Figure 6 This is a schematic diagram of the module structure of a device for evaluating the continuous charging performance of a lithium-ion battery according to an embodiment of the present application;

[0059] Figure 7 Schematic diagram of the device structure of the hardware operating environment involved in the method for evaluating the continuous charging performance of a lithium-ion battery in an embodiment of the present application.

[0060] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0061] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0062] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0063] It should be noted that the execution subject of this embodiment can be a computing service device with data processing, network communication and program running functions, such as a tablet computer, a personal computer, a mobile phone, etc., or an electronic device capable of realizing the above functions, a lithium-ion battery continuous charging performance evaluation device, etc., and this embodiment does not specifically limit this. The following takes the lithium-ion battery continuous charging performance evaluation device as an example to illustrate this embodiment and the following embodiments.

[0064] The present application embodiment provides a method for evaluating the continuous charging performance of a lithium-ion battery, referring to Figure 1 , Figure 1 This is a flow chart of a first embodiment of a method for evaluating continuous charging performance of a lithium-ion battery of the present invention.

[0065] In this embodiment, the method for evaluating the continuous charging performance of a lithium-ion battery includes steps S10 to S40:

[0066] Step S10, dividing the operating temperature range of the battery cell in the lithium-ion battery into a plurality of temperature intervals, setting a plurality of characteristic temperatures in the temperature interval according to a preset temperature gradient, and setting a plurality of characteristic states of charge in the state of charge range according to a preset charge gradient;

[0067] It should be noted that the operating temperature range of the battery cell generally refers to the temperature range in which the battery cell works normally, which can be set according to actual conditions and is not specifically limited thereto. The battery cell in this embodiment is a lithium-ion battery cell. In this embodiment, the operating temperature range of the battery cell is divided into multiple temperature intervals, and the temperature intervals include at least a low temperature zone, a normal temperature zone, and a high temperature zone. The characteristic temperature refers to the pre-set operating temperature of the battery cell, and the preset temperature gradient is the gradient between the characteristic temperatures.

[0068] For example, if the operating temperature range is T min ~T max , the preset temperature gradient is ΔT, and in the order of temperature from low to high, the characteristic temperature in the entire operating temperature range can be expressed as T 1 、T 2 ,…,T n , the low temperature zone can be set as T 1 ~T l , normal temperature zone is T l ~T m , high temperature zone is T m ~T n , where T min is the minimum operating temperature of the battery cell, T max is the maximum operating temperature of the battery cell, then T 1 =T min , T n =T max , T n =T 1 +ΔT·(n-1), l<m<n.

[0069] In addition, it should be noted that the state of charge range refers to the range of the state of charge (SOC) of the battery cell, usually 0 to 100%. The characteristic state of charge refers to a preset battery cell SOC value, and the preset charge gradient is the gradient between characteristic states of charge.

[0070] For example, if the preset charge gradient is ΔSOC, then SOC i =i·ΔSOC, where i is the i-th SOC value. It can be understood that SOC 1 =0 is the minimum SOC value of the battery cell, SOC j=100% is the maximum SOC value of the battery cell, 0≤i≤j.

[0071] Step S20, selecting a target characteristic temperature from the temperature range, and determining the maximum charging current corresponding to the different characteristic states of charge of the battery cell at each target characteristic temperature based on the negative electrode potential safety threshold line and the linear curves of the negative electrode potential and the dynamic charging current corresponding to the different characteristic states of charge of the battery cell at each target characteristic temperature;

[0072] It should be noted that the target characteristic temperature is the temperature selected from the characteristic temperature of each temperature interval in this embodiment. Based on the target characteristic temperature of each temperature interval, the maximum charging current is determined under different characteristic charge states to evaluate the continuous charging capability of the battery cell at different temperatures.

[0073] In a feasible implementation, step S20 may include steps S201 to S202:

[0074] Step S201, obtaining linear curves of negative electrode potential and dynamic charging current of the battery cell at different characteristic charge states at each target characteristic temperature;

[0075] In a feasible implementation, step S201 may include steps S2011 to S2014:

[0076] Step S2011, discharging the battery cell to a first state of charge according to a preset discharge current;

[0077] It should be noted that the first state of charge refers to SOC=0, and the preset discharge current is a set current for discharge use, for example: 1C, which is not specifically limited.

[0078] It can be understood that the battery cell is discharged at the 1C standard to the discharge cut-off voltage, at which time SOC=0 is satisfied.

[0079] Step S2012, based on a dynamic current test strategy, at different target characteristic temperatures, performing a charging test on the battery cell to charge the battery cell to a second state of charge, wherein the dynamic current test strategy adopts a plurality of preset charging currents;

[0080] It should be noted that the second state of charge refers to SOC = 100%. The dynamic current test strategy refers to using a plurality of preset charging currents to perform charging tests on the battery cells respectively.

[0081] It can be understood that at the target characteristic temperature, the battery cell is charged with different charging currents to charge the battery cell to the charging cut-off voltage, which satisfies SOC = 100%. The charging current can be recorded as I 1 ,I 2 ,…,I n .

[0082] Step S2013, based on the three-electrode strategy, recording the negative electrode potential data and battery voltage data of the battery cell during the charging test, and generating a change curve of the negative electrode potential and the state of charge corresponding to each target characteristic temperature of the battery cell under different charging currents;

[0083] It should be noted that the three-electrode strategy is the three-electrode method. The three-electrode strategy measures the electrode potential by introducing a reference electrode. The reference electrode is an electrode used as a reference comparison when measuring the positive / negative electrode potential of the battery. This electrode does not participate in charging and discharging, has no polarization effect, and can accurately detect the potential value of the measured battery cell. The measured electrode and the reference electrode with a known precise electrode potential value constitute a battery cell. The electromotive force value of the battery cell is measured, and the electrode potential of the measured electrode can be calculated. Therefore, this embodiment adopts a three-electrode strategy to record the negative electrode potential of the battery cell during the charging test and the battery voltage at the same time.

[0084] During the charging test, the negative electrode potential and battery voltage of the battery cell will change with the change of SOC. According to the negative electrode potential corresponding to different characteristic charge states at each target characteristic temperature, the curve of the negative electrode potential changing with SOC at each target characteristic temperature can be obtained, that is, the change curve of the negative electrode potential and the state of charge at each target characteristic temperature. According to the battery voltage corresponding to different characteristic charge states at each target characteristic temperature, the curve of the battery voltage changing with SOC at each target characteristic temperature can be obtained, that is, the change curve of the battery voltage and the state of charge at each target characteristic temperature. For example, assuming that the selected target characteristic temperature is T k , the characteristic state of charge is SOC 1 =0, SOC 2 ,…,SOC i ,…,SOC j , i = 0, 1, ..., j, we can get Figure 2 The similar curves of negative electrode potential and state of charge and battery voltage and state of charge in the figure may have different changing rules due to different battery systems and different battery types. Therefore, Figure 2 Just an example.

[0085] Since the present embodiment adopts different charging currents to perform charging test on the battery cells, each charging current has a corresponding change curve. That is to say, if the dynamic current test strategy sets n charging currents, then at the target characteristic temperature, n change curves of the negative electrode potential and the state of charge corresponding to different charging currents and n change curves of the battery voltage and the state of charge can be obtained.

[0086] Step S2014, based on the change curves of the negative electrode potential and the state of charge of the battery cell corresponding to each target characteristic temperature under different charging currents, determine the linear curves of the negative electrode potential and the dynamic charging current corresponding to different characteristic states of charge of the battery cell at each target characteristic temperature.

[0087] In a feasible implementation, step S2014 may include: determining the charging current data and negative electrode potential data corresponding to different characteristic states of charge of the battery cell at each target characteristic temperature based on the change curve of the negative electrode potential and state of charge corresponding to each target characteristic temperature under different charging currents, and screening out valid linear data; fitting the valid linear data corresponding to different characteristic states of charge of the battery cell at each target characteristic temperature to obtain the linear curve of the negative electrode potential and charging current corresponding to different characteristic states of charge of the battery cell at each target characteristic temperature.

[0088] It should be noted that, according to the change curves of the negative electrode potential and the state of charge corresponding to each target characteristic temperature of the battery cell under different charging currents, the charging current and the negative electrode potential corresponding to each characteristic state of charge under the target characteristic temperature can be found. Since n change curves of the negative electrode potential and the state of charge corresponding to different charging currents can be obtained under the target characteristic temperature, n corresponding charging currents and negative electrode potentials can be obtained for the same characteristic state of charge under the target characteristic temperature. For example, assuming that the selected target characteristic temperature is T k , the selected characteristic state of charge is SOC i , extract the target characteristic temperature as T k And the state of charge is SOC i For data on different charging currents and negative electrode potentials, refer to Figure 3 , the intersection A represents a data point. Since each target characteristic temperature has n curves of the change of negative electrode potential and state of charge corresponding to different charging currents, the target characteristic temperature is T k And the state of charge is SOC i There are n intersection points A, denoted by A 1 ~A n , point A 1 =(I 1 , V cath1 ), point A 2 =(I 2 , V cath2 ), point A n =(I n , V cath,n ), point A n The characteristic temperature is T k , characteristic state of charge is SOC i And the charging current is I n The negative electrode potential at .

[0089] It can be understood that according to the charging current data and negative electrode potential data corresponding to different characteristic charge states of the battery cell at each target characteristic temperature, the negative electrode potential V cath The linear curve of negative electrode potential and charging current I is obtained by comparing the linear curve of negative electrode potential and charging current corresponding to different characteristic charge states of the battery cell at each target characteristic temperature. cath -I curve meets the better linearity, and it is necessary to make certain trade-offs in the data so that the fitting curve meets the linear relationship. The effective linear data is the data that can meet the linear requirements after screening. For example, refer to Figure 3 , point A 3 The linear curve cannot be satisfied and the data needs to be eliminated.

[0090] It should be understood that the effective linear data corresponding to each characteristic state of charge at the target characteristic temperature are fitted to obtain a linear curve of the negative electrode potential and the charging current corresponding to each characteristic state of charge at the target characteristic temperature, thereby obtaining a linear curve of the negative electrode potential and the charging current corresponding to different characteristic states of charge of the battery cell at each target characteristic temperature. For example, the target characteristic temperature is T k And the state of charge is SOC i When , we can fit Figure 3 The linear curve of negative electrode potential and charging current is shown.

[0091] Step S202, determining the intersection points between the negative electrode potential safety threshold line and each linear curve, and taking the charging current at the intersection points corresponding to different characteristic charge states of the battery cell at each target characteristic temperature as the maximum charging current.

[0092] It should be noted that the negative electrode potential safety threshold line is the negative electrode potential safety threshold line where lithium plating does not occur. During the charging process of lithium batteries, lithium ions will be deintercalated from the positive electrode and embedded in the negative electrode. When some abnormal conditions occur, it is easy to cause the lithium deintercalated from the positive electrode to be unable to be embedded in the negative electrode. At this time, the lithium ions will precipitate on the surface of the negative electrode, forming a layer of gray substance. This phenomenon is called lithium plating. As the charging rate increases, the charging current increases, the polarization effect increases, the lithium ion embedding reaction kinetics and the diffusion rate in the solid phase of the negative electrode material decrease, and the negative electrode potential gradually decreases. At the same time, polarization will also cause the lithium plating potential to shift negatively. Therefore, the standard lithium plating potential is considered to be ≤0V. When the negative electrode potential is lower than the lithium plating potential, lithium plating will occur, especially under low temperature conditions, it is easy to form lithium dendrites, pierce the diaphragm and cause a short circuit, and there is a risk of battery life attenuation and safety risks.

[0093] In order to ensure that the negative electrode potential has sufficient redundancy and ensure the safety of the battery cell throughout its life cycle, it is necessary to set the negative electrode potential higher than the standard lithium deposition potential as a safety potential, also known as the negative electrode potential safety threshold V Saf, used to determine the negative electrode potential safety threshold line, the negative electrode potential safety threshold V Saf It can be set to 10mV. It can also be flexibly adjusted according to actual needs, and there is no specific limitation on this. The negative electrode potential safety threshold line is a parallel line that is independent of the charging rate.

[0094] It is understandable that this embodiment needs to find the intersection between the negative electrode potential safety threshold line and each linear curve, and the charging current at the intersection is the maximum charging current corresponding to the target characteristic temperature and characteristic state of charge. Figure 3 Point B is the negative electrode potential safety threshold line and the linear curve (the target characteristic temperature is T k And the state of charge is SOC i ), the charging current I corresponding to point B at this time MAx That is, the target characteristic temperature is T k And the state of charge is SOC i The maximum charging current at When a point A n When the potential is lower than the negative electrode safety threshold line, it means that the corresponding charging current has the risk of negative electrode lithium deposition, so this point should be eliminated.

[0095] Thus, the maximum charging current corresponding to different characteristic charge states of the battery cell at each target characteristic temperature can be obtained, that is:

[0096]

[0097] Among them, T k represents the kth target characteristic temperature, SOC i represents the i-th characteristic state of charge, Indicates that the cell is at the target characteristic temperature T k and characteristic state of charge SOC i The maximum charging current under

[0098] Step S30, determining charging performance data for each temperature interval based on the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in each temperature interval, wherein different strategies are used to determine the charging performance data for different temperature intervals;

[0099] It should be noted that the charging performance data of each temperature range, i.e., the continuous charging capacity of the battery cell in each temperature range, is usually characterized by the maximum charging current corresponding to different temperatures and different SOCs. Since different temperature ranges need to consider different influencing factors, different temperature ranges need to further adopt different strategies to determine the charging performance data based on the maximum charging current corresponding to different characteristic charge states at the target characteristic temperature of the temperature range. The target characteristic temperature in the normal temperature range is all the characteristic temperatures in the normal temperature range, the target characteristic temperature in the low temperature range is a preset number of characteristic temperatures selected in the low temperature range, and the target characteristic temperature in the high temperature range is all the characteristic temperatures in the high temperature range.

[0100] In a feasible implementation, step S30 may include steps S301 to S302:

[0101] Step S301, determining charging performance data in the normal temperature range based on the maximum charging current corresponding to different characteristic charge states of the battery cell at a target characteristic temperature in the normal temperature range;

[0102] It should be noted that the target characteristic temperature in the normal temperature zone selected in this embodiment is all characteristic temperatures in the normal temperature zone. Therefore, the maximum charging current corresponding to different characteristic charge states of the battery cell at the characteristic temperature in the normal temperature zone is the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the normal temperature zone. The maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the normal temperature zone can be used to characterize the continuous charging capacity of the battery cell in the normal temperature zone. After arranging in a certain order, the charging performance data of the normal temperature zone is generated. It is assumed that the working condition of all temperature values ​​in the normal temperature zone is T l ~T m , then the charging performance data in the normal temperature zone can be expressed as:

[0103]

[0104] Where, T k Indicates T l ~T m The kth characteristic temperature, SOC i represents the i-th characteristic state of charge, I nor (T, SOC) represents the charging performance data in the normal temperature zone. Indicates that the cell is at characteristic temperature T k and characteristic state of charge SOC i The maximum charging current under

[0105] Step S302, fitting a maximum charging current calculation model for the low temperature zone based on the maximum charging current corresponding to different characteristic charge states of the battery cells at target characteristic temperatures in the normal temperature zone and the low temperature zone, and determining charging performance data for the low temperature zone based on the maximum charging current calculation model;

[0106] It should be noted that low temperature has a great impact on charging capacity, so a preset number of characteristic temperatures are selected in the low temperature zone to evaluate charging capacity, and the charging capacity is determined by function fitting in the remaining low temperature zone temperatures. The preset number can be 3, and the specific number and specific value are not specifically limited. For example, the low temperature zone T 1 ~T l The target characteristic temperature selected is T x 、T y 、T z , T 1 ≤T x ≤T y ≤T z ≤T l , T x =-20℃, T y =-10℃, T z =0℃, the continuous charging capability of the battery cell at the target characteristic temperature can be expressed as:

[0107]

[0108]

[0109]

[0110] Where, T x 、T y 、T z Indicates the target characteristic temperature in the low temperature zone, SOC i represents the i-th characteristic state of charge, Indicates that the cell is at the target characteristic temperature T x and characteristic state of charge SOC i The maximum charging current under Indicates that the cell is at the target characteristic temperature T y and characteristic state of charge SOC i The maximum charging current under Indicates that the cell is at the target characteristic temperature T z and characteristic state of charge SOC i The maximum charging current under Respectively represent the battery cell at the target characteristic temperature T x 、T y 、T z Continuous charging capability.

[0111] It can be understood that the maximum charging current corresponding to different characteristic charge states of the battery cell at each target characteristic temperature in the normal temperature zone and the low temperature zone is used, with temperature as the independent variable and maximum charging current as the dependent variable, and a polynomial function is used to fit the relationship between the maximum charging current and temperature to obtain a maximum charging current calculation model for the low temperature zone, which is used to estimate the maximum charging current corresponding to different SOCs at other characteristic temperatures in the low temperature zone, thereby confirming the continuous charging capacity of the low temperature zone. The polynomial function used for fitting can be a binomial or a difference form, and there is no specific limitation on this. For example, if the polynomial function used for fitting is I=aT 2 +bT+c, we can get Figure 4 The fitting curve is shown.

[0112] It should be understood that by using the maximum charging current calculation model in the low temperature zone, the maximum charging current at other characteristic temperatures in the low temperature zone can be obtained, so as to use the maximum charging current corresponding to the different characteristic charge states of the battery cell at all characteristic temperatures in the low temperature zone to characterize the continuous charging capacity of the battery cell in the low temperature zone. After arranging in a certain order, the charging performance data of the low temperature zone is generated.

[0113] Step S303, based on the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone, determine the maximum safe charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone, and generate charging performance data for the high temperature zone based on the maximum safe charging current.

[0114] It should be noted that the charging capacity (maximum charging current) is greatly affected by temperature, which is mainly manifested in the following aspects: under high temperature conditions, the activity of the positive and negative active materials increases, which will accelerate the rate of chemical reactions inside the battery, aggravate the side reaction of lithium ion diffusion speed, and accelerate battery aging, thereby shortening the battery cycle life; under high temperature conditions, the stability of the SEI film may be destroyed, and the side reaction of electrolyte decomposition and the structural decay of the positive electrode material may be increased. Therefore, under the same state of charge, the high temperature charging current cannot be higher than the maximum charging current at room temperature. At the same time, under adiabatic conditions, the temperature rise of the battery cell is calculated, and the maximum charging current is checked and controlled to ensure that the battery works safely under high temperature conditions. At this time, a safe maximum charging current can be further determined, that is, the maximum safe charging current, which is used to characterize the continuous charging capacity of the battery cell in the high temperature zone. After arranging in a certain order, the charging performance data of the high temperature zone is generated. Assuming that all temperature values ​​in the high temperature zone are T m ~T n , then the charging performance data in the high temperature zone can be expressed as:

[0115]

[0116] Where, T h Indicates Tm ~T n The hth characteristic temperature, SOC i represents the i-th characteristic state of charge, I hot (T, SOC) represents the charging performance data in the high temperature zone, Indicates that the cell is at characteristic temperature T h and characteristic state of charge SOC i The maximum safe charging current.

[0117] In a feasible implementation, step S303 may include steps S3031 to S3033:

[0118] Step S3031, obtaining the maximum charging current with temperature rise corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone;

[0119] It should be noted that the maximum charging current under temperature rise refers to the maximum charging current obtained based on the temperature rise.

[0120] In a feasible implementation, step S3031 may include: obtaining the correspondence between the specific heat capacity of the battery cell, the mass of the battery cell, the temperature difference, the dynamic internal resistance of the battery cell and the maximum charging current with temperature rise; based on the specific heat capacity of the battery cell, the mass of the battery cell, the dynamic internal resistance of the battery cell, the temperature difference between the target characteristic temperature in the high temperature zone and the upper limit of the operating temperature, and the correspondence, determining the maximum charging current with temperature rise corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone.

[0121] It should be noted that the temperature difference refers to the difference between the target characteristic temperature and the upper limit of the operating temperature, which is the upper limit of the operating temperature range of the battery cell. The corresponding relationship between the specific heat capacity of the battery cell, the mass of the battery cell, the temperature difference, the dynamic internal resistance of the battery cell and the maximum charging current at temperature rise is the calculation formula for the maximum charging current at temperature rise. Under adiabatic conditions, if I 2 ·R·t=c p ·m·Δt, we can get: Therefore, the characteristic temperature is T h And the characteristic state of charge is SOC i When the maximum charging current based on temperature rise, that is, the maximum charging current based on temperature rise is:

[0122]

[0123] In the formula, Indicates that the cell is at characteristic temperature T h and characteristic state of charge SOC i Maximum charging current under temperature rise, c p is the specific heat capacity of the battery cell, m is the mass of the battery cell, Δt is the temperature difference, Δt=T limit -Th , T limit is the upper limit of the cell operating temperature, T h is the target characteristic temperature, R is the dynamic internal resistance of the battery cell. The dynamic internal resistance of 100s DC charging under normal temperature conditions can be selected. The 100s polarization effect is relatively stable, which is also in line with the internal resistance level of actual operation and can be flexibly adjusted according to actual needs.

[0124] It is understandable that the maximum safe charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone cannot be greater than the maximum charging current at temperature rise.

[0125] Step S3032, determining the upper limits of the current in the normal temperature zone corresponding to the different characteristic states of charge at the target characteristic temperature of the battery cell in the normal temperature zone based on the maximum charging currents corresponding to the different characteristic states of charge, and adjusting the maximum charging currents corresponding to the different characteristic states of charge at the target characteristic temperature of the high temperature zone based on the upper limits of the current in the normal temperature zone corresponding to the different characteristic states of charge;

[0126] It should be noted that the upper limit of current in the normal temperature zone is the maximum value of the maximum charging current in the normal temperature zone corresponding to each characteristic state of charge. Since the charging current at high temperature cannot be higher than the maximum charging current at normal temperature under the same state of charge, it is necessary to limit the maximum charging current in the high temperature zone according to the upper limit of current in the normal temperature zone corresponding to different characteristic states of charge, so that the maximum charging current corresponding to different characteristic states of charge at the target characteristic temperature of the normal temperature zone of the battery cell will not exceed the upper limit of current in the normal temperature zone of the corresponding characteristic state of charge.

[0127] Step S3033, based on the principle of safety first, from the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone and the maximum charging current with temperature rise, determine the current with the smallest value as the maximum safe charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone.

[0128] It is understandable that, following the principle of safety first, the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone cannot be greater than the maximum charging current at temperature rise. Therefore, a minimum value needs to be selected as the corresponding maximum safe charging current, as shown below:

[0129]

[0130] Where, T h Indicates high temperature zone T m ~T n The hth characteristic temperature, SOC i represents the i-th characteristic state of charge, Indicates that the cell is at characteristic temperature T h and characteristic state of charge SOCi The maximum safe charging current under Indicates that the cell is at characteristic temperature T h and characteristic state of charge SOC i Maximum charging current under temperature rise, Indicates that the cell is at characteristic temperature T h and characteristic state of charge SOC i The maximum charging current under

[0131] Step S40, based on the charging performance data of each temperature interval, determining the charging performance data of the battery cell within the operating temperature range:

[0132] It should be noted that by integrating the charging performance data of each temperature range, the charging performance data of the battery cell within the operating temperature range can be obtained:

[0133]

[0134] Where, T 1 ~T n Indicates characteristic temperature, SOC i represents the i-th characteristic state of charge, I(T, SOC) represents the charging performance data within the operating temperature range, Indicates the continuous charging capability of the battery cell at different characteristic temperatures and different characteristic states of charge.

[0135] Step S50, based on the charging performance data of the battery cell within the operating temperature range and based on the dual safety margin dynamic adjustment strategy, a corresponding continuous charging MAP is formulated to evaluate and verify the continuous charging performance of the lithium-ion battery at the current temperature.

[0136] It should be noted that the continuous charging capability of the above-mentioned battery cells is used as a benchmark to develop the continuous charging MAP of the battery cells and conduct evaluation and verification. In order to ensure the safe and efficient operation of the battery cells, the principle of the continuous charging MAP system is to determine the maximum charging current according to the dual safety margin dynamic adjustment strategy, that is, to set the temperature safety margin and the state of charge safety margin. When the state of charge is less than the preset boundary, the maximum charging current is determined according to the preset temperature safety margin and the state of charge safety margin.

[0137] Based on the operating temperature range of the battery cell, select the verification characteristic temperature. Based on the verification characteristic temperature, determine the verification target temperature according to the preset temperature safety margin. The temperature safety margin is based on the verification characteristic temperature increased by εΔT, and the increased temperature is selected as the verification target temperature, where ε is the temperature safety factor, usually set to 1 or 2, and ΔT is the preset temperature gradient. It can be seen that the temperature safety margin is determined according to the temperature safety factor and the preset temperature gradient, which is the product of the temperature safety factor and the preset temperature gradient. The verification characteristic temperature is increased according to the temperature safety margin, and the resulting temperature is the verification target temperature.

[0138] Based on the verification target temperature, a charge and discharge cycle test is performed (charging means selecting the corresponding charging current of the corresponding charging MAP). After the cycle test, the battery cell is fully charged under the corresponding conditions, that is, SOC=100%, and the battery cell is disassembled to check whether there is lithium deposition on the interface to verify the reliability of the continuous charging MAP. If lithium deposition occurs, the current needs to be readjusted for evaluation and verification.

[0139] Exemplarily, the verification characteristic temperature may be 20°C, 0°C, -10°C, -20°C, without specific limitation. If the preset temperature gradient ΔT = 5°C, the temperature safety factor ε = 1, the state of charge safety factor β = 1, and the calculated temperature safety margin εΔT = 5°C, the verification characteristic temperature is increased by 5°C, and the increased temperature value is selected as the verification target temperature. The corresponding verification target temperatures are 25°C, 5°C, -5°C, and -15°C.

[0140] The present embodiment provides a method for evaluating the continuous charging performance of a lithium-ion battery. At different temperatures and different states of charge, a linear curve of the negative electrode potential and the dynamic charging current is obtained by combining a dynamic current method and a three-electrode method, and a negative electrode potential safety threshold line of the lithium plating potential is set. The intersection of the linear curve and the negative electrode potential safety threshold line is used to determine the maximum charging current of the battery cell at different temperatures and different states of charge, and the maximum continuous charging capacity of the battery cell is quickly and accurately evaluated. At the same time, based on the maximum continuous charging capacity of the battery cell, a continuous charging strategy and a charging MAP of the battery cell are formulated to ensure the safety of the battery cell throughout its life cycle and achieve safe and efficient operation of the power battery.

[0141] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as those in the above-mentioned embodiment 1 can be referred to the above introduction, and will not be repeated in the following. Figure 5 , step S50 may include steps S501 to S504:

[0142] Step S501, obtaining the current state of charge and current temperature;

[0143] It should be noted that the current state of charge refers to the current SOC value of the battery cell, and the current temperature refers to the current temperature of the battery cell.

[0144] Step S502, when the current state of charge is less than the preset boundary state of charge, determining the target temperature according to the current temperature and the temperature safety margin, wherein the temperature safety margin is determined according to the temperature safety factor and the preset temperature gradient;

[0145] It should be noted that the preset boundary state of charge is a preset boundary SOC value, for example: SOC=60%, which can be set according to actual conditions and is not specifically limited. When the current state of charge is less than the preset boundary state of charge, a continuous charging MAP needs to be formulated according to the temperature safety margin.

[0146] Temperature safety margin refers to the amount of time that the battery is adjusted at the current temperature when setting the continuous charging MAP. ε ΔT, select the charging capacity corresponding to the lowered temperature value as the fast charge MAP value, where ε is the temperature safety factor, usually set to 1 or 2, and ΔT is the preset temperature gradient. It can be seen that the temperature safety margin is determined according to the temperature safety factor and the preset temperature gradient, which is the product of the temperature safety factor and the preset temperature gradient. The current temperature is lowered according to the temperature safety margin, and the resulting temperature is the target temperature.

[0147] Step S503, determining a target state of charge according to the current state of charge and a state of charge safety margin, wherein the state of charge safety margin is determined according to a state of charge safety factor and a preset charge gradient;

[0148] It should be noted that the state of charge safety margin refers to the selection of the charging capacity corresponding to the increased SOC value as the fast charge MAP value when formulating the continuous charging MAP, based on the current state of charge, by adjusting βΔSOC, where β is the state of charge safety factor, usually set to 1 or 2, and ΔSOC is the preset charge gradient. It can be seen that the state of charge safety margin is determined based on the state of charge safety factor and the preset charge gradient, which is the product of the state of charge safety factor and the preset charge gradient. The current state of charge is adjusted upward according to the state of charge safety margin, and the resulting state of charge is the target state of charge.

[0149] Step S504 , based on the target temperature and the target state of charge, a corresponding target maximum charging current is determined in the charging performance data, and based on the target maximum charging current, a continuous charging MAP at the current temperature is generated.

[0150] It is understandable that according to the target temperature and the target state of charge, the appropriate maximum charging current, that is, the target maximum charging current The final continuous charge MAP can then be specified based on the target maximum charge current.

[0151] It should be understood that if the SOC value is high, the charging current at this time is small and the difference is not large. Therefore, when the current state of charge is greater than or equal to the preset boundary state of charge, the charging performance data corresponding to the target temperature and the current state of charge can be used to formulate a continuous charging MAP, that is, the target maximum charging current is determined according to the target temperature and the current state of charge to generate a continuous charging MAP at the current temperature.

[0152] Exemplarily, the maximum continuous charging capacity (charging current) of the battery cell at 20°C and 25°C is shown in Table 1, with a preset temperature gradient ΔT=5°C, a preset SOC gradient ΔSOC=10%, a temperature safety factor ε=1, a state of charge safety factor β=1, and a pre-charge boundary state of charge of SOC=60%. If the current temperature of the battery cell is 25°C and the current state of charge is less than 60%, the temperature safety margin εΔT=5°C is calculated, the current temperature is lowered by 5°C, and the charging capacity corresponding to the lowered temperature value is selected as the fast charging MAP value, that is, the target temperature is 20°C, the charging capacity corresponding to 20°C is selected, and the state of charge safety margin βΔSOC=10% is calculated, the current state of charge is increased by 10%, and the charging capacity corresponding to the increased state of charge is selected as the fast charging MAP value, that is, the target state of charge is the current SOC+10%, and the corresponding charging capacity is selected; if the current state of charge is greater than or equal to 60%, the corresponding charging capacity is determined according to the target temperature and the current state of charge. The final continuous charging MAP corresponding to 25°C is shown in Table 2.

[0153] Table 1

[0154]

[0155] Table 2

[0156]

[0157] The present embodiment provides a method for evaluating the continuous charging performance of a lithium-ion battery. At different temperatures and different states of charge, a linear curve of the negative electrode potential and the dynamic charging current is obtained by combining a dynamic current method and a three-electrode method, and a negative electrode potential safety threshold line of the lithium plating potential is set. The intersection of the linear curve and the negative electrode potential safety threshold line is used to determine the maximum charging current of the battery cell at different temperatures and different states of charge, and the maximum continuous charging capacity of the battery cell is quickly and accurately evaluated. At the same time, based on the maximum continuous charging capacity of the battery cell, a continuous charging strategy and a charging MAP of the battery cell are formulated to ensure the safety of the battery cell throughout its life cycle and achieve safe and efficient operation of the power battery.

[0158] This application also provides a device for evaluating the continuous charging performance of a lithium-ion battery. Figure 6 , the evaluation device for the continuous charging performance of lithium-ion batteries includes:

[0159] The parameter division module 10 is used to divide the operating temperature range of the battery cell in the lithium-ion battery into a plurality of temperature intervals, set a plurality of characteristic temperatures in the temperature interval according to a preset temperature gradient, and set a plurality of characteristic charge states in the charge state range according to a preset charge gradient, wherein the temperature interval includes at least a low temperature zone, a normal temperature zone, and a high temperature zone;

[0160] The data calculation module 20 is used to select a target characteristic temperature from the temperature range, and determine the maximum charging current corresponding to the different characteristic charge states of the battery cell at each target characteristic temperature based on the negative electrode potential safety threshold line and the linear curves of the negative electrode potential and the dynamic charging current corresponding to the different characteristic charge states of the battery cell at each target characteristic temperature;

[0161] The data calculation module 20 is further used to determine the charging performance data of each temperature interval based on the maximum charging current corresponding to the different characteristic charge states of the battery cell at the target characteristic temperature of each temperature interval, wherein different strategies are used to determine the charging performance data for different temperature intervals;

[0162] The data calculation module 20 is further used to determine the charging performance data of the battery cell within the operating temperature range based on the charging performance data of each temperature interval;

[0163] The performance evaluation module 30 is used to formulate a corresponding continuous charging MAP based on the charging performance data of the battery cell within the operating temperature range and based on the dual safety margin dynamic adjustment strategy, and evaluate and verify the continuous charging performance of the lithium-ion battery at the current temperature.

[0164] In a feasible implementation manner, the data calculation module 20 is further used to obtain a linear curve of the negative electrode potential and the dynamic charging current of the battery cell at different characteristic charge states at each target characteristic temperature;

[0165] Determine the intersection point between the negative electrode potential safety threshold line and each linear curve;

[0166] The charging current at the intersection of the battery cell corresponding to different characteristic charge states at each target characteristic temperature is taken as the maximum charging current.

[0167] In a feasible implementation manner, the data calculation module 20 is further configured to discharge the battery cell to a first state of charge according to a preset discharge current;

[0168] Based on a dynamic current test strategy, a charging test is performed on the battery cell at different target characteristic temperatures to charge the battery cell to a second state of charge, wherein the dynamic current test strategy adopts a plurality of preset charging currents;

[0169] Based on the three-electrode strategy, the negative electrode potential data and battery voltage data of the battery cell during the charging test are recorded to generate the change curves of the negative electrode potential and the state of charge corresponding to each target characteristic temperature of the battery cell under different charging currents;

[0170] Based on the change curves of the negative electrode potential and the state of charge of the battery cell corresponding to each target characteristic temperature under different charging currents, the linear curves of the negative electrode potential and the dynamic charging current corresponding to different characteristic states of charge of the battery cell at each target characteristic temperature are determined.

[0171] In a feasible implementation manner, the data calculation module 20 is further used to determine the charging current data and negative electrode potential data corresponding to different characteristic charge states of the battery cell at each target characteristic temperature based on the change curves of the negative electrode potential and the charge state of the battery cell at each target characteristic temperature under different charging currents, and screen out valid linear data;

[0172] The effective linear data corresponding to different characteristic charge states of the battery cell at each target characteristic temperature are fitted to obtain the linear curves of the negative electrode potential and the charging current corresponding to different characteristic charge states of the battery cell at each target characteristic temperature.

[0173] In a feasible implementation manner, the data calculation module 20 is further used to determine the charging performance data in the normal temperature zone based on the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the normal temperature zone;

[0174] Based on the maximum charging current corresponding to different characteristic charge states of the battery cells at target characteristic temperatures in the normal temperature zone and the low temperature zone, a maximum charging current calculation model for the low temperature zone is fitted, and based on the maximum charging current calculation model, the charging performance data for the low temperature zone is determined;

[0175] Based on the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone, the maximum safe charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone is determined, and based on the maximum safe charging current, the charging performance data for the high temperature zone is generated.

[0176] In a feasible implementation manner, the data calculation module 20 is further used to obtain the maximum charging current with a temperature rise corresponding to different characteristic charge states of the battery cell at a target characteristic temperature in the high temperature zone;

[0177] Based on the maximum charging current corresponding to different characteristic states of charge at the target characteristic temperature of the battery cell in the normal temperature zone, the upper limit of the current in the normal temperature zone corresponding to the different characteristic states of charge is determined, and based on the upper limit of the current in the normal temperature zone corresponding to the different characteristic states of charge, the maximum charging current corresponding to different characteristic states of charge at the target characteristic temperature of the battery cell in the high temperature zone is adjusted;

[0178] Based on the principle of safety first, the current with the smallest value is determined from the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone and the maximum charging current with temperature rise as the maximum safe charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone.

[0179] In a feasible implementation manner, the data calculation module 20 is further used to obtain the corresponding relationship between the specific heat capacity of the battery cell, the mass of the battery cell, the temperature difference, the dynamic internal resistance of the battery cell and the maximum charging current with temperature rise;

[0180] Based on the specific heat capacity of the battery cell, the battery cell mass, the dynamic internal resistance of the battery cell, the temperature difference between the target characteristic temperature in the high temperature zone and the upper limit of the operating temperature, and the corresponding relationship, the maximum charging current corresponding to the temperature rise of the battery cell at different characteristic charge states at the target characteristic temperature in the high temperature zone is determined.

[0181] In a feasible implementation manner, the performance evaluation module 30 is further used to obtain the current state of charge and the current temperature;

[0182] When the current state of charge is less than the preset boundary state of charge, the target temperature is determined according to the current temperature and the temperature safety margin, and the temperature safety margin is determined according to the temperature safety factor and the preset temperature gradient;

[0183] Determine the target state of charge according to the current state of charge and the state of charge safety margin, the state of charge safety margin is determined according to the state of charge safety factor and the preset charge gradient;

[0184] Based on the target temperature and the target state of charge, determining a corresponding target maximum charging current in the charging performance data;

[0185] Generates a continuous charge MAP for the current temperature based on the target maximum charge current.

[0186] The device for evaluating the continuous charging performance of a lithium-ion battery provided in the present application adopts the method for evaluating the continuous charging performance of a lithium-ion battery in the above-mentioned embodiment, and can solve the technical problem that the traditional method for evaluating the continuous charging performance of a lithium-ion battery is relatively complicated, costly, and difficult to implement quickly and accurately. Compared with the prior art, the beneficial effects of the device for evaluating the continuous charging performance of a lithium-ion battery provided in the present application are the same as the beneficial effects of the method for evaluating the continuous charging performance of a lithium-ion battery provided in the above-mentioned embodiment, and the other technical features of the device for evaluating the continuous charging performance of a lithium-ion battery are the same as the features disclosed in the above-mentioned embodiment method, and are not described in detail here.

[0187] The present application provides a device for evaluating the continuous charging performance of a lithium-ion battery, the device comprising: at least one processor; and a memory connected to the at least one processor in communication; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method for evaluating the continuous charging performance of a lithium-ion battery in the first embodiment.

[0188] Reference below Figure 7 , which shows a schematic diagram of the structure of a device for evaluating the continuous charging performance of a lithium-ion battery suitable for realizing the embodiment of the present application. The device for evaluating the continuous charging performance of a lithium-ion battery in the embodiment of the present application may include, but is not limited to, mobile terminals such as mobile phones, laptop computers, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions), PMPs (Portable Media Players), vehicle-mounted terminals (such as vehicle-mounted navigation terminals), etc., and fixed terminals such as digital TVs, desktop computers, etc. Figure 7 The illustrated evaluation device for continuous charging performance of a lithium-ion battery is merely an example and should not limit the functions and scope of use of the embodiments of the present application.

[0189] like Figure 7As shown, the evaluation device for continuous charging performance of lithium-ion batteries may include a processing device 1001 (e.g., a central processing unit, a graphics processor, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM: Read Only Memory) 1002 or a program loaded from a storage device 1003 to a random access memory (RAM: Random Access Memory) 1004. Various programs and data required for the operation of the evaluation device for continuous charging performance of lithium-ion batteries are also stored in RAM1004. The processing device 1001, ROM1002, and RAM1004 are connected to each other via a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Typically, the following systems can be connected to the I / O interface 1006: input devices 1007 including, for example, a touch screen, a touchpad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; output devices 1008 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; storage devices 1003 including, for example, a magnetic tape, a hard disk, etc.; and communication devices 1009. The communication device 1009 can allow the evaluation device for the continuous charging performance of a lithium-ion battery to communicate wirelessly or wired with other devices to exchange data. Although the figure shows an evaluation device for the continuous charging performance of a lithium-ion battery with various systems, it should be understood that it is not required to implement or have all the systems shown. More or fewer systems may be implemented or have instead.

[0190] In particular, according to the embodiments disclosed in the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiments disclosed in the present application include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through a communication device, or installed from a storage device 1003, or installed from a ROM 1002. When the computer program is executed by the processing device 1001, the above-mentioned functions defined in the method of the embodiment disclosed in the present application are executed.

[0191] The lithium-ion battery continuous charging performance evaluation device provided by the present application adopts the lithium-ion battery continuous charging performance evaluation method in the above-mentioned embodiment, which can solve the technical problems that the traditional method of evaluating the continuous charging performance of lithium-ion batteries is relatively complicated, costly, and difficult to achieve quickly and accurately. Compared with the prior art, the beneficial effects of the lithium-ion battery continuous charging performance evaluation device provided by the present application are the same as the beneficial effects of the lithium-ion battery continuous charging performance evaluation method provided by the above-mentioned embodiment, and the other technical features of the lithium-ion battery continuous charging performance evaluation device are the same as the features disclosed in the method of the previous embodiment, and will not be repeated.

[0192] It should be understood that the various parts disclosed in this application can be implemented by hardware, software, firmware or a combination thereof. In the description of the above embodiments, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0193] The above are only specific implementations 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.

[0194] The present application provides a computer-readable storage medium having computer-readable program instructions (ie, computer programs) stored thereon, and the computer-readable program instructions are used to execute the method for evaluating the continuous charging performance of a lithium-ion battery in the above-mentioned embodiment.

[0195] The computer-readable storage medium provided in the present application may be, for example, a USB flash drive, but is not limited to electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, systems or devices, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, system or device. The program code contained on the computer-readable storage medium may be transmitted using any appropriate medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination of the above.

[0196] The computer-readable storage medium carries one or more programs. When the one or more programs are executed by the lithium-ion battery continuous charging performance evaluation device, the lithium-ion battery continuous charging performance evaluation device: divides the operating temperature range of the battery cell in the lithium-ion battery into multiple temperature intervals, sets multiple characteristic temperatures in the temperature interval according to a preset temperature gradient, and sets multiple characteristic charge states in the charge state range according to a preset charge gradient, wherein the temperature interval includes at least a low temperature zone, a normal temperature zone, and a high temperature zone; selects a target characteristic temperature from the temperature interval, and calculates the negative electrode potential and the dynamic charge state based on the negative electrode potential safety threshold line and the negative electrode potential corresponding to the different characteristic charge states of the battery cell at each target characteristic temperature. The linear curve of the charging current is used to determine the maximum charging current corresponding to different characteristic states of charge of the battery cell at each target characteristic temperature; the charging performance data of each temperature interval is determined based on the maximum charging current corresponding to different characteristic states of charge of the battery cell at the target characteristic temperature of each temperature interval, wherein different strategies are used to determine the charging performance data for different temperature intervals; based on the charging performance data of each temperature interval, the charging performance data of the battery cell within the operating temperature range is determined; based on the charging performance data of the battery cell within the operating temperature range and based on the dual safety margin dynamic adjustment strategy, the corresponding continuous charging MAP is formulated to evaluate and verify the continuous charging performance of the lithium-ion battery at the current temperature.

[0197] Computer program code for performing the operations of the present application may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0198] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession 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 square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0199] The readable storage medium provided by the present application is a computer-readable storage medium, which stores computer-readable program instructions (i.e., computer programs) for executing the above-mentioned method for evaluating the continuous charging performance of lithium-ion batteries, and can solve the technical problems that the traditional method for evaluating the continuous charging performance of lithium-ion batteries is relatively complex, costly, and difficult to implement quickly and accurately. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided by the present application are the same as the beneficial effects of the method for evaluating the continuous charging performance of lithium-ion batteries provided by the above-mentioned embodiments, and will not be repeated here.

[0200] The present application also provides a computer program product, including a computer program, which implements the steps of the above-mentioned method for evaluating the continuous charging performance of a lithium-ion battery when the computer program is executed by a processor.

[0201] The computer program product provided by the present application can solve the technical problem that the traditional method of evaluating the continuous charging performance of lithium-ion batteries is relatively complicated, costly, and difficult to achieve quickly and accurately. Compared with the prior art, the beneficial effects of the computer program product provided by the present application are the same as the beneficial effects of the method for evaluating the continuous charging performance of lithium-ion batteries provided in the above embodiment, and will not be described in detail here.

[0202] The above are only some embodiments of the present application, and are not intended to limit the patent scope of the present application. All equivalent structural changes made using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A method for evaluating the continuous charging performance of a lithium-ion battery, characterized in that: The method comprises: Dividing the operating temperature range of the battery cell in the lithium-ion battery into a plurality of temperature intervals, setting a plurality of characteristic temperatures in the temperature interval according to a preset temperature gradient, and setting a plurality of characteristic charge states in the charge state range according to a preset charge gradient, wherein the temperature interval includes at least a low temperature zone, a normal temperature zone, and a high temperature zone; Select a target characteristic temperature from the temperature range, and determine the maximum charging current corresponding to the different characteristic states of charge of the battery cell at each target characteristic temperature based on the negative electrode potential safety threshold line and the linear curves of the negative electrode potential and the dynamic charging current corresponding to the different characteristic states of charge of the battery cell at each target characteristic temperature; Determine charging performance data for each temperature interval based on the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in each temperature interval, wherein different strategies are used to determine the charging performance data for different temperature intervals; Determining charging performance data of the battery cell within the operating temperature range based on the charging performance data of each temperature interval; Based on the charging performance data of the battery cell within the operating temperature range and based on the dual safety margin dynamic adjustment strategy, a corresponding continuous charging MAP is formulated to evaluate and verify the continuous charging performance of the lithium-ion battery at the current temperature.

2. The method according to claim 1, characterized in that The step of determining the maximum charging current corresponding to different characteristic states of charge of the battery cell at each target characteristic temperature based on the negative electrode potential safety threshold line and the linear curves of the negative electrode potential and the dynamic charging current corresponding to different characteristic states of charge of the battery cell at each target characteristic temperature comprises: Obtaining linear curves of negative electrode potential and dynamic charging current of the battery cell under different characteristic charge states at each target characteristic temperature; Determine the intersection point between the negative electrode potential safety threshold line and each linear curve; The charging current at the intersection of the battery cell corresponding to different characteristic charge states at each target characteristic temperature is taken as the maximum charging current.

3. The method according to claim 2, characterized in that The step of obtaining a linear curve of the negative electrode potential and the dynamic charging current corresponding to different characteristic charge states of the battery cell at each target characteristic temperature comprises: Discharging the battery cell to a first state of charge according to a preset discharge current; Based on a dynamic current test strategy, a charging test is performed on the battery cell at different target characteristic temperatures to charge the battery cell to a second state of charge, wherein the dynamic current test strategy adopts a plurality of preset charging currents; Based on the three-electrode strategy, the negative electrode potential data and battery voltage data of the battery cell during the charging test are recorded, and the change curves of the negative electrode potential and the state of charge of the battery cell corresponding to each target characteristic temperature under different charging currents are generated; Based on the change curves of the negative electrode potential and the state of charge of the battery cell corresponding to each target characteristic temperature under different charging currents, a linear curve of the negative electrode potential and the dynamic charging current corresponding to different characteristic states of charge of the battery cell at each target characteristic temperature is determined.

4. The method according to claim 3, characterized in that The step of determining the linear curves of the negative electrode potential and the dynamic charging current corresponding to different characteristic states of charge of the battery cell at each target characteristic temperature based on the change curves of the negative electrode potential and the state of charge corresponding to each target characteristic temperature of the battery cell under different charging currents comprises: Based on the change curves of the negative electrode potential and the state of charge of the battery cell at each target characteristic temperature under different charging currents, the charging current data and the negative electrode potential data corresponding to different characteristic states of charge of the battery cell at each target characteristic temperature are determined, and valid linear data are screened out; The effective linear data corresponding to different characteristic charge states of the battery cell at each target characteristic temperature are fitted to obtain linear curves of negative electrode potential and charging current corresponding to different characteristic charge states of the battery cell at each target characteristic temperature.

5. The method according to claim 1, characterized in that The target characteristic temperature in the normal temperature zone is all characteristic temperatures in the normal temperature zone, the target characteristic temperature in the low temperature zone is a preset number of characteristic temperatures selected from the low temperature zone, and the target characteristic temperature in the high temperature zone is all characteristic temperatures in the high temperature zone. The step of determining the charging performance data of each temperature interval based on the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in each temperature interval includes: Determining charging performance data in the normal temperature range based on maximum charging currents corresponding to different characteristic charge states of the battery cell at a target characteristic temperature in the normal temperature range; Based on the maximum charging currents corresponding to different characteristic charge states of the battery cell at target characteristic temperatures in the normal temperature zone and the low temperature zone, a maximum charging current calculation model for the low temperature zone is fitted, and charging performance data for the low temperature zone is determined based on the maximum charging current calculation model; Based on the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone, the maximum safe charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone is determined, and based on the maximum safe charging current, the charging performance data of the high temperature zone is generated.

6. The method according to claim 5, characterized in that The step of determining the maximum safe charging current corresponding to different characteristic states of charge of the battery cell at the target characteristic temperature in the high temperature zone based on the maximum charging current corresponding to different characteristic states of charge of the battery cell at the target characteristic temperature in the high temperature zone comprises: Obtaining the maximum charging current with temperature rise corresponding to different characteristic charge states of the battery cell at a target characteristic temperature in a high temperature zone; Based on the maximum charging current corresponding to different characteristic states of charge at the target characteristic temperature of the battery cell in the normal temperature zone, the upper limit of the current in the normal temperature zone corresponding to the different characteristic states of charge is determined, and based on the upper limit of the current in the normal temperature zone corresponding to the different characteristic states of charge, the maximum charging current corresponding to different characteristic states of charge of the battery cell at the target characteristic temperature in the high temperature zone is adjusted; Based on the principle of safety first, the current with the smallest value is determined from the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone and the maximum charging current with temperature rise as the maximum safe charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone.

7. The method according to claim 6, characterized in that The step of obtaining the maximum charging current with temperature rise corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone comprises: Obtain the corresponding relationship between the specific heat capacity of the battery cell, the mass of the battery cell, the temperature difference, the dynamic internal resistance of the battery cell and the maximum charging current with temperature rise; Based on the specific heat capacity of the battery cell, the mass of the battery cell, the dynamic internal resistance of the battery cell, the temperature difference between the target characteristic temperature in the high temperature zone and the upper limit of the operating temperature, and the corresponding relationship, the maximum charging current with temperature rise corresponding to different characteristic charge states of the battery cell at the target characteristic temperature in the high temperature zone is determined.

8. The method according to any one of claims 1 to 7, characterized in that The step of formulating a corresponding continuous charging MAP based on the charging performance data of the battery cell within the operating temperature range and based on a dual safety margin dynamic adjustment strategy, and evaluating and verifying the continuous charging performance of the lithium-ion battery at the current temperature includes: Get the current state of charge and current temperature; When the current state of charge is less than a preset boundary state of charge, determining a target temperature according to the current temperature and a temperature safety margin, wherein the temperature safety margin is determined according to a temperature safety factor and a preset temperature gradient; Determining a target state of charge according to the current state of charge and a state of charge safety margin, wherein the state of charge safety margin is determined according to a state of charge safety factor and a preset charge gradient; Based on the target temperature and the target state of charge, determining a corresponding target maximum charging current in the charging performance data; Based on the target maximum charging current, a continuous charging MAP at the current temperature is generated.

9. A device for evaluating the continuous charging performance of a lithium-ion battery, characterized in that: The device for evaluating the continuous charging performance of a lithium-ion battery comprises: A parameter division module, used to divide the operating temperature range of the battery cell in the lithium-ion battery into multiple temperature intervals, set multiple characteristic temperatures in the temperature interval according to a preset temperature gradient, and set multiple characteristic charge states in the charge state range according to a preset charge gradient, wherein the temperature interval includes at least a low temperature zone, a normal temperature zone, and a high temperature zone; A data calculation module is used to select a target characteristic temperature from the temperature range, and determine the maximum charging current corresponding to the different characteristic states of charge of the battery cell at each target characteristic temperature based on the negative electrode potential safety threshold line and the linear curves of the negative electrode potential and the dynamic charging current corresponding to the different characteristic states of charge of the battery cell at each target characteristic temperature; The data calculation module is further used to determine the charging performance data of each temperature interval based on the maximum charging current corresponding to different characteristic charge states of the battery cell at the target characteristic temperature of each temperature interval, wherein different strategies are used to determine the charging performance data in different temperature intervals; The data calculation module is further used to determine the charging performance data of the battery cell within the operating temperature range based on the charging performance data of each temperature interval; The performance evaluation module is used to formulate a corresponding continuous charging MAP based on the charging performance data of the battery cell within the operating temperature range and based on a dual safety margin dynamic adjustment strategy, and evaluate and verify the continuous charging performance of the lithium-ion battery at the current temperature.

10. A device for evaluating the continuous charging performance of a lithium-ion battery, characterized in that: The device comprises: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the method for evaluating the continuous charging performance of a lithium-ion battery according to any one of claims 1 to 8.

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