Method, device, medium, BMS system and vehicle for online adjusting charging strategy

Abstract

The present invention relates to a method, device, medium, BMS system and vehicle for online adjusting a charging strategy. The method includes: online monitoring the cell temperature, cell health state, state of charge and internal resistance characteristics; determining a stepped charging strategy under the current cell temperature and the current cell health state according to a first mapping relationship, a second mapping relationship or a third mapping relationship; wherein, the first mapping relationship records the internal resistance relationship between different cell temperature conditions and the reference charging temperature condition under 100% cell health state; the second mapping relationship records the internal resistance relationship between different cell health state conditions under a preset temperature condition and 100% cell health state; the third mapping relationship records the internal resistance relationship between different cell temperature conditions and different cell health state conditions and the reference charging temperature condition and 100% cell health state. The present invention can realize online real-time adjustment of the charging strategy based on real-time internal resistance testing.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a method, device, medium, BMS system and vehicle for online adjusting a charging strategy. Background Art

[0002] The determination of voltage and current in the charging strategy aims to ensure the safety and rapidity of the battery cells during the charging process, with no lithium plating on the negative electrode and no oxygen evolution on the positive electrode side. As the SOH of the battery cells changes, the charging capacity of the battery cells decreases, and adjustment needs to be made by reducing the current or voltage. At present, most of the adjustment methods are to perform a large-scale refresh of the built-in charging strategy. Since the attenuation mechanisms of the battery cells are inconsistent, the resulting attenuation degrees are also inconsistent. Therefore, different strategies need to be adopted for battery cells with different attenuation degrees.

[0003] The existing charging strategy is generally formulated by observing the negative electrode interface or by measuring the potential of the negative electrode side through a three-electrode test. However, the existing methods need to remotely refresh the program at a charging station to update, and cannot correct the charging strategy in a timely manner according to the health state of the battery cells. Moreover, the program refresh takes a long time and cannot cover the entire life cycle of the battery and the battery pack. The sudden changes in charging time and charging capacity after the program refresh also bring a bad experience to customers. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method, device, medium, BMS system and vehicle for online adjusting a charging strategy in view of the problems existing in the prior art.

[0005] To solve the above technical problem, the present invention provides a method for online adjusting a charging strategy, including the following steps: online monitoring the cell temperature, cell health state, state of charge and internal resistance characteristics; wherein, the internal resistance characteristics include at least one of the positive electrode internal resistance of the cell, the negative electrode internal resistance of the cell and the total internal resistance of the cell; determining a step charging strategy under the current cell temperature and current cell health state according to at least one of a first mapping relationship, a second mapping relationship and a third mapping relationship; wherein, the first mapping relationship records the internal resistance relationship between different cell temperature conditions under 100% cell health state and the reference charging temperature condition; the second mapping relationship records the internal resistance relationship between different cell health state conditions under a preset temperature condition and 100% cell health state; the third mapping relationship records the internal resistance relationship between different cell temperature conditions and different cell health state conditions and the reference charging temperature condition and 100% cell health state.

[0006] The beneficial effect of the present invention is that based on real-time internal resistance testing, relying on offline stored data and an online monitoring platform, the battery cells can adjust the charging current-SOC strategy online and without damage, and generate a step charging strategy under different cell temperatures and different cell health states.

[0007] Based on the above technical solutions, the present invention can be further improved as follows.

[0008] Furthermore, the above technical solution further includes the step of pre-generating a first mapping relationship, which specifically includes:

[0009] Using the HPPC method to obtain the internal resistance characteristics of the three-electrode battery cell of BOL at 100% battery cell health state and the reference charging temperature;

[0010] Using the HPPC method to obtain the internal resistance characteristics of the three-electrode battery cell of BOL at 100% battery cell health state and other battery cell temperature conditions other than the reference charging temperature;

[0011] Using the first mapping relationship to record the following resistance relationships at 100% battery cell health state:

[0012] Recording the ratio of the internal resistance of the positive electrode of the battery cell under different battery cell temperature conditions to the internal resistance of the positive electrode of the battery cell under the reference charging temperature condition, denoted as the first ratio a i ; i takes different positive numbers, representing different battery cell temperatures;

[0013] And recording the ratio of the internal resistance of the negative electrode of the battery cell under different battery cell temperature conditions to the internal resistance of the negative electrode of the battery cell under the reference charging temperature condition, denoted as the second ratio b i ,

[0014] And recording the ratio of the internal resistance of the positive electrode of the battery cell to the total internal resistance of the battery cell at different battery cell temperatures, denoted as the first proportion α i , recording the ratio of the internal resistance of the negative electrode of the battery cell to the total internal resistance of the battery cell at different battery cell temperatures, denoted as the second proportion β i , α i +β i = 1.

[0015] The beneficial effect of adopting the above further solution is that by testing the internal resistances of the positive and negative electrodes of the battery cell and the total internal resistance of the battery cell under different battery cell temperature conditions, and recording the relationships between the internal resistances of the positive and negative electrodes of the battery cell under different battery cell temperature conditions and the internal resistance of the battery cell under the reference charging temperature condition and the internal resistance ratios under different battery cell temperature conditions at 100% battery cell health state, it is convenient to determine the corresponding relationship between the internal resistances of the positive and negative electrodes of the battery cell and the internal resistance of the battery cell under the reference temperature condition according to the on-line real-time monitored battery cell temperature during the use of the battery cell, and then quickly formulate the corresponding real-time charging strategy according to the corresponding relationship and the strategy under the reference charging temperature.

[0016] Furthermore, the above technical solution further includes the step of pre-generating a second mapping relationship, which specifically includes:

[0017] Using the HPPC method to obtain the internal resistance characteristics of the three-electrode battery cell of BOL at the preset battery cell temperature condition and 100% battery cell health state;

[0018] The internal resistance characteristics of a three - electrode battery cell of BOL under preset battery cell temperature conditions and different battery cell health states are obtained by using the HPPC method;

[0019] Using the second mapping relationship to record the following resistance relationships under preset battery cell temperature conditions:

[0020] Record the ratio of the internal resistance of the positive electrode of the battery cell under different battery cell health state conditions to the internal resistance of the positive electrode of the battery cell in the 100% battery cell health state, denoted as the third ratio a j ; j takes different positive numbers, representing different battery cell health states;

[0021] And record the ratio of the internal resistance of the negative electrode of the battery cell under different battery cell health state conditions to the internal resistance of the negative electrode of the battery cell in the 100% battery cell health state, denoted as the fourth ratio b j ;

[0022] And record the ratio of the internal resistance of the positive electrode of the battery cell under different battery cell health state conditions to the total internal resistance of the battery cell, denoted as the third proportion α j , record the ratio of the internal resistance of the negative electrode of the battery cell under different battery cell health state conditions to the total internal resistance of the battery cell, denoted as the fourth proportion β j , α j +β j = 1.

[0023] The beneficial effect of adopting the above - mentioned further solution is that by testing the total internal resistance and internal resistance ratio of the battery cell under different battery cell health state conditions under preset battery cell temperature conditions, the internal resistances of the positive and negative electrodes of the battery cell under the current battery cell health state condition are determined according to the total internal resistance and internal resistance ratio of the battery cell, and the relationships between the internal resistances of the positive and negative electrodes of the battery cell under different battery cell temperature conditions and different battery cell health states and those of the battery cell under the reference charging temperature condition are recorded. It is convenient to determine the corresponding relationship between the internal resistances of the positive and negative electrodes of the battery cell and the internal resistance of the battery cell in the 100% battery cell health state according to the on - line real - time monitored battery cell temperature and battery cell health state during the use of the battery cell. Furthermore, the corresponding real - time charging strategy can be quickly formulated according to the corresponding relationship and the charging strategy in the 100% battery cell health state.

[0024] Furthermore, the above - mentioned technical solution also includes the step of pre - generating a third mapping relationship, specifically including:

[0025] Using the HPPC method to obtain the internal resistance characteristics of a three - electrode battery cell of BOL under the reference charging temperature condition and 100% battery cell health state;

[0026] Using the HPPC method to obtain the internal resistance characteristics of a three - electrode battery cell of BOL under different battery cell temperature conditions and different battery cell health states;

[0027] Using the third mapping relationship to record the following resistance relationships:

[0028] Record the ratio of the internal resistance of the positive electrode of the battery cell under different battery cell temperatures and different state of health conditions to the internal resistance of the positive electrode of the battery cell at the reference charging temperature and 100% state of health of the battery cell, denoted as the fifth ratio a ij ; ij takes different positive numbers, representing different battery cell temperatures and different states of health of the battery cell;

[0029] And record the ratio of the internal resistance of the negative electrode of the battery cell under different battery cell temperatures and different state of health conditions to the internal resistance of the negative electrode of the battery cell at the reference charging temperature and 100% state of health of the battery cell, denoted as the sixth ratio b ij ;

[0030] And record the ratio of the internal resistance of the positive electrode of the battery cell to the total internal resistance of the battery cell under different battery cell temperatures and different state of health conditions, denoted as the fifth ratio α ij , record the ratio of the internal resistance of the negative electrode of the battery cell to the total internal resistance of the battery cell under different state of health conditions of the battery cell, denoted as the sixth ratio β ij , α ij +β ij =1

[0031] The beneficial effect of adopting the above further solution is that by testing the internal resistance and internal resistance ratio of the battery cell under different battery cell temperatures and different state of health conditions of the battery cell, the internal resistance of the positive and negative electrodes of the battery cell under different battery cell temperatures and different state of health conditions is determined according to the internal resistance and internal resistance ratio of the battery cell, and the relationship between the internal resistance of the positive and negative electrodes of the battery cell under different battery cell temperatures and different state of health conditions and the internal resistance of the positive and negative electrodes of the battery cell at the reference charging temperature and 100% state of health of the battery cell is recorded, which is convenient for determining the corresponding relationship between the internal resistance of the positive and negative electrodes of the battery cell and the internal resistance of the battery cell at the reference charging temperature and 100% state of health of the battery cell according to the on-line real-time monitored battery cell temperature and battery cell state of health during the use of the battery cell, and then quickly formulating the corresponding real-time charging strategy according to the corresponding relationship and the reference charging strategy.

[0032] Further, determine the step charging strategy under the current battery cell temperature and the current state of health of the battery cell according to at least one of the first mapping relationship, the second mapping relationship and the third mapping relationship. The calculation process is as follows: determine that the maximum current value Imax under the current battery cell temperature and the state of health SOH of the battery cell takes the value of min(Imax3, Imax4); Imax3 = SOH * min(Imax1, Imax2) / a j ; Imax4 = SOH * min(Imax1, Imax2) / b j ; Imax1 = I1 / a i ; Imax2 = I1 / b i ; or Imax takes the value of min(Imax5, Imax6) Imax5 = SOH * I1 / a ij ; Imax6 = SOH * I1 / bij ;

[0033] Among them, I1 is the charging current under the reference charging strategy condition; SOH represents the current cell health state, and a i is the ratio of the internal resistance of the positive electrode of the cell under the condition that the current cell temperature is i to the internal resistance of the positive electrode of the cell under the reference charging temperature condition when the cell health state is 100%; b i is the ratio of the internal resistance of the negative electrode of the cell under the condition that the current cell temperature is i to the internal resistance of the negative electrode of the cell under the reference charging temperature condition when the cell health state is 100%; a j is the ratio of the internal resistance of the positive electrode of the cell under the condition that the current cell health state is j to the internal resistance of the positive electrode of the cell when the cell health state is 100% under the preset cell temperature condition; b j is the ratio of the internal resistance of the positive electrode of the cell under the condition that the current cell health state is j to the internal resistance of the positive electrode of the cell when the cell health state is 100% under the preset cell temperature condition;

[0034] a ij is the ratio of the internal resistance of the positive electrode of the cell under the condition that the current cell temperature is i and the current health state is j to the internal resistance of the positive electrode of the cell under the reference charging temperature and 100% cell health state; b ij is the ratio of the internal resistance of the positive electrode of the cell under the condition that the current cell temperature is i and the current health state is j to the internal resistance of the positive electrode of the cell under the reference charging temperature and 100% cell health state.

[0035] The beneficial effect of adopting the above further solution is that the stepped charging strategy under the current cell temperature and the current cell health state is determined according to at least one of the first mapping relationship, the second mapping relationship, and the third mapping relationship, which is convenient for the cell to quickly determine the matching real-time charging strategy according to the on-line real-time monitored cell temperature and cell health state during use.

[0036] To solve the above technical problems, the present invention provides a device for online adjusting a charging strategy based on the internal resistance characteristics of battery cells, including an information acquisition module, a data storage module, and a data processing module; the information acquisition module is used for online monitoring the battery cell temperature, the battery cell health state, the state of charge, and the internal resistance characteristics; wherein, the internal resistance characteristics include at least one of the positive electrode internal resistance of the battery cell, the negative electrode internal resistance of the battery cell, and the total internal resistance of the battery cell; the data storage module is used for storing at least one of a first mapping relationship, a second mapping relationship, and a third mapping relationship; wherein, the first mapping relationship records the internal resistance relationship between different battery cell temperature conditions and the reference charging temperature condition under the condition of 100% battery cell health state; the second mapping relationship records the internal resistance relationship between different battery cell health state conditions under a preset temperature condition and the internal resistance under the condition of 100% battery cell health state; the third mapping relationship records the internal resistance relationship between different battery cell temperature conditions and different battery cell health state conditions and the reference charging temperature condition and 100% battery cell health state; the data processing module is used for determining the step charging strategy of the current battery cell according to at least one of the first mapping relationship, the second mapping relationship, and the third mapping relationship based on the current battery cell temperature and the current battery cell health state.

[0037] Based on the above technical solution, the present invention can be further improved as follows.

[0038] Further, the data processing module is specifically used for: determining that the maximum current value Imax under the conditions of the current battery cell temperature and the battery cell health state SOH takes the value of min(Imax3, Imax4); Imax3 = SOH * min(Imax1, Imax2) / a j ; Imax4 = SOH * min(Imax1, Imax2) / b j ; Imax1 = I1 / a i ; Imax2 = I1 / b i ; or Imax takes the value of min(Imax5, Imax6) Imax5 = SOH * I1 / a ij ; Imax6 = SOH * I1 / b ij ;

[0039] Wherein, I1 is the charging current under the condition of the reference charging strategy; SOH represents the current battery cell health state, a i is the ratio of the positive electrode internal resistance of the battery cell at the current battery cell temperature i under the condition of 100% battery cell health state to the positive electrode internal resistance under the reference charging temperature condition; b i is the ratio of the negative electrode internal resistance of the battery cell at the current battery cell temperature i under the condition of 100% battery cell health state to the negative electrode internal resistance under the reference charging temperature condition; a jis the ratio of the internal resistance of the positive electrode of the battery cell under the condition that the current battery cell health state is j to the internal resistance of the positive electrode of the battery cell under the condition of 100% battery cell health state at the preset battery cell temperature condition; b j is the ratio of the internal resistance of the positive electrode of the battery cell under the condition that the current battery cell health state is j to the internal resistance of the positive electrode of the battery cell under the condition of 100% battery cell health state at the preset battery cell temperature condition;

[0040] a ij is the ratio of the internal resistance of the positive electrode of the battery cell under the condition that the current battery cell temperature is i and the current health state is j to the internal resistance of the positive electrode of the battery cell under the reference charging temperature and 100% battery cell health state; b ij is the ratio of the internal resistance of the positive electrode of the battery cell under the condition that the current battery cell temperature is i and the current health state is j to the internal resistance of the positive electrode of the battery cell under the reference charging temperature and 100% battery cell health state.

[0041] To solve the above technical problems, the present invention provides a computer-readable storage medium, including instructions, which when running on a computer, cause the computer to execute the online adjustment charging strategy method of the above technical solution.

[0042] To solve the above technical problems, the present invention provides a vehicle-mounted BMS system, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the method of online adjustment charging strategy described in the above technical solution.

[0043] To solve the above technical problems, the present invention provides a vehicle, including the vehicle-mounted BMS system of the above technical solution.

[0044] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is the flowchart of the method for online adjustment charging strategy provided by the embodiment of the present invention;

[0046] Figure 2 is the charging SOC-negative electrode potential curve graph obtained by charging the battery cell at different rates by the trial current method at the reference temperature provided by the embodiment of the present invention;

[0047] Figure 3 is the fast charging strategy curve graph at different battery cell temperatures provided by the embodiment of the present invention;

[0048] Figure 4 is the fast charging strategy curve graph at different SOHs at the reference temperature T1 provided by the embodiment of the present invention;

[0049] Figure 5 is the block diagram of the method for online adjustment charging strategy provided by the embodiment of the present invention. Specific Embodiments

[0050] The following specific examples illustrate the embodiments of the present disclosure. Those skilled in the art can easily understand the other advantages and effects of the present disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all embodiments. The present disclosure can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present disclosure without creative efforts belong to the scope of protection of the present disclosure.

[0051] It should be noted that the following describes various aspects of embodiments within the scope of the appended claims. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is illustrative only. Based on the present disclosure, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement a device and / or practice a method. Additionally, this device and / or this method can be implemented using other structures and / or functionality in addition to one or more of the aspects described herein.

[0052] Figure 1 It is a flowchart of a method for online adjusting a charging strategy provided by an embodiment of the present invention. As Figure 1 shown, the method includes:

[0053] S110, online monitoring the cell temperature, cell health state, state of charge, and internal resistance characteristics; wherein, the internal resistance characteristics include at least one of the positive electrode internal resistance of the cell, the negative electrode internal resistance of the cell, and the total internal resistance of the cell;

[0054] S120, determining a stepped charging strategy under the current cell temperature and the current cell health state according to at least one of a first mapping relationship, a second mapping relationship, and a third mapping relationship.

[0055] Among them, the first mapping relationship records the internal resistance relationship between different cell temperature conditions and the reference charging temperature condition under 100% cell health state; the second mapping relationship records the internal resistance relationship between different cell health state conditions under a preset temperature condition and the internal resistance under 100% cell health state; the third mapping relationship records the internal resistance relationship between different cell temperature conditions and different cell health state conditions and the reference charging temperature condition and 100% cell health state.

[0056] Existing charging strategies generally include built-in fixed charging strategies or offline refreshed programs to update charging strategies, or require loading a communication module on the BMS to upload data to the background. After analysis by the background, a usage strategy suitable for this battery pack is formulated. None of these can update the charging strategy in real time.

[0057] An embodiment of the present invention provides a method for online adjusting a charging strategy. This method online monitors the cell temperature, cell health state, state of charge, and cell internal resistance. Based on real-time internal resistance testing, according to offline stored data and online monitored data, the cell can adjust the charging current-SOC strategy online and without loss, and generate a stepped charging strategy under different cell temperatures and different cell health states.

[0058] The BOL (Beginning of Life) charging strategy formulated by the trial current method under the reference charging temperature and 100% cell health state SOH1 is used as the reference charging strategy. Specifically, the capacity or voltage is used as the cut-off condition, and the charging strategy is verified by cyclic disassembly. No lithium plating occurs at the negative electrode interface. First, charge at different currents (currents between the minimum current and the maximum current) under the reference temperature T1 (10°C - 40°C) until reaching the negative electrode cut-off potential (-50 mV to 100 mV) of the fabricated three-electrode cell or the upper limit voltage of the cell to stop charging. Among them, the negative electrode cut-off potential is regarded as the lithium plating potential.

[0059] An embodiment of the present invention formulates a reference charging strategy according to the trial current method. The charging strategy meets the requirements of the upper and lower limits of the positive and negative electrodes, ensuring that no lithium plating occurs at the negative electrode of the cell and no overcharging occurs at the positive electrode. Then, based on the reference charging strategy and the internal resistance relationship between the reference charging temperature, reference SOH and the measured temperature, measured SOH, a charging strategy for the measured temperature and measured SOH is derived. And the derived strategy is corrected to check its upper and lower limits of the positive and negative electrodes to meet the requirements of charging safety.

[0060] Based on the above embodiments, the embodiment of the present invention further includes the step of pre-generating the first mapping relationship, specifically including:

[0061] a1. Obtain the internal resistance characteristics of a three - electrode cell at BOL (beginning of life) under 100% cell health state and the reference charging temperature T1 using the HPPC (Hybrid Pulse Power Characteristic) method; including the internal resistance R of the positive electrode of the first cell T1+ , the internal resistance R of the negative electrode of the first cell T1- , and the total internal resistance R of the first cell T1 .

[0062] a2. Obtain the internal resistance characteristics of a three - electrode cell at BOL under 100% cell health state and other cell temperature conditions (such as at temperature T2) other than the reference charging temperature using the HPPC method; including the internal resistance R of the positive electrode of the second cell T2+ , the internal resistance R of the negative electrode of the second cell T2- , and the total internal resistance R of the second cell T2 .

[0063] a3. Calculate the ratio of the internal resistance of the positive electrode of the cell under the undetermined temperature and SOC conditions to that under the reference charging temperature conditions (i.e., the first ratio a i ; i takes different positive numbers, representing different cell temperatures), the ratio of the internal resistance of the negative electrode (i.e., the second ratio b i ), as well as the proportion of the internal resistance of the positive electrode (i.e., the first proportion α i ) and the proportion of the internal resistance of the negative electrode (i.e., the second proportion β i ) at different cell temperatures. Among them, the ratio of the internal resistance of the positive electrode a i = R T2+ / R T1+ ; the ratio of the internal resistance of the negative electrode b i = R T2- / R T1- ; when the cell temperature i takes the temperature T1, the proportion of the internal resistance of the positive electrode α T1 = R T1+ / R T1 , the proportion of the internal resistance of the negative electrode β T1＝ R T1- / R T1 ; when the cell temperature i takes the temperature T2, the proportion of the internal resistance of the positive electrode α T2 = R T2+ / R T2 , the proportion of the internal resistance of the negative electrode β T2 = R T2- / R T2 ;

[0064] a4. Use the above - mentioned ratios as coefficients for calculating the charging current at the undetermined strategy temperature T2 and SOC. At the undetermined temperature T2 and SOC conditions, Imax1 = I1 / a i ; Imax2 = I1 / b i; I1 is the charging current under the reference charging strategy condition; the value of Imax under the undetermined strategy temperature T2 and SOC condition is min(Imax1, Imax2).

[0065] a5. Obtain the maximum current under other temperatures and other SOC states according to the methods of a2 - a4, and generate a charging strategy map, that is, an SOC - temperature - current map.

[0066] a6. Use the first mapping relationship to record the ratio of the internal resistance of the positive and negative electrodes of the battery cell under different battery cell temperature conditions to the internal resistance of the positive and negative electrodes of the battery cell under the reference charging temperature condition, and the internal resistance ratio at different battery cell temperatures when the battery cell health state is 100%.

[0067] In the embodiment of the present invention, by testing the internal resistance and internal resistance ratio of the positive and negative electrodes of the battery cell under different battery cell temperature conditions when the battery cell health state is 100%, and recording the relationship between the internal resistance of the positive and negative electrodes of the battery cell under different battery cell temperature conditions and the internal resistance of the positive and negative electrodes of the battery cell under the reference charging temperature condition, as well as the internal resistance ratio under different battery cell temperature conditions, it is convenient to determine the corresponding relationship between the internal resistance of the positive and negative electrodes of the battery cell and the internal resistance of the battery cell under the reference temperature condition according to the on - line real - time monitored battery cell temperature during the use of the battery cell, and then quickly formulate the corresponding real - time charging strategy according to the corresponding relationship and the reference charging strategy.

[0068] On the basis of the above - mentioned embodiment, the embodiment of the present invention further includes the step of pre - generating a second mapping relationship, which specifically includes:

[0069] b1. Online test the total internal resistance R of the battery cell under the condition of a preset battery cell temperature (such as temperature T2). T2 , and respectively determine the positive - electrode internal resistance R T2 = R SOH2+ * α T2 and the negative - electrode internal resistance R T2 = R * β SOH2- of the battery cell under the current battery cell health state according to the total internal resistance R T2 ;

[0070] b2. Calculate the ratio of the positive - electrode internal resistance of the battery cell under the undetermined SOH - T2 charging temperature condition to the positive - electrode internal resistance of the battery cell under the T2 charging temperature condition and when the battery cell health state is 100% (i.e., the third ratio a j ; j takes different positive numbers, representing different battery cell health states) a j = R SOH2+ / R T2+ and the ratio of the negative - electrode internal resistance (i.e., the fourth ratio b j ) b j = R SOH2- / R T2- .

[0071] b3. Use the above ratio as the coefficient for calculating the to-be-determined charging current. Under the to-be-determined conditions, Imax3 = SOH * min(Imax1, Imax2) / a j ; Imax4 = SOH * min(Imax1, Imax2) / b j . Under the to-be-determined SOH-T2 conditions, the value of Imax is min(Imax3, Imax4);

[0072] b4. Obtain the maximum current under other temperatures, other SOH states, and other SOC states according to the methods of b1 - b3, and generate a charging strategy map under the to-be-determined SOH state.

[0073] b5. The second mapping relationship records the ratio of the positive and negative internal resistances of the battery cell under the condition of the preset battery cell temperature and different battery cell health states (SOH) to the positive and negative internal resistances of the battery cell under the condition of the preset battery cell temperature and 100% battery cell health state.

[0074] In the embodiment of the present invention, by testing the total internal resistance and the internal resistance ratio of the battery cell under different battery cell health states under the condition of the preset battery cell temperature, the positive and negative internal resistances of the battery cell under the current battery cell health state condition are determined according to the total internal resistance and the internal resistance ratio of the battery cell, and the relationship between the positive and negative internal resistances of the battery cell under the condition of the preset battery cell temperature and different battery cell health states and the positive and negative internal resistances of the battery cell under the condition of the preset battery cell temperature and 100% battery cell health state is recorded, which is convenient for determining the corresponding relationship between the positive and negative internal resistances of the battery cell and the internal resistance of the battery cell under the corresponding battery cell temperature and 100% battery cell health state according to the online real-time monitored battery cell temperature and battery cell health state during the use of the battery cell, and then quickly formulating the corresponding real-time charging strategy according to the corresponding relationship and the strategy under the condition of the preset battery cell temperature and 100% battery cell health state.

[0075] Further, the above technical solution further includes the step of pre-generating a third mapping relationship, which specifically includes: obtaining the internal resistance characteristics of the three-electrode battery cell at BOL under the condition of the preset battery cell temperature and 100% battery cell health state by using the HPPC method; obtaining the internal resistance characteristics of the three-electrode battery cell at BOL under the condition of the preset battery cell temperature and different battery cell health states by using the HPPC method; using the second mapping relationship to record the following resistance relationships under the condition of the preset battery cell temperature: recording the ratio of the positive internal resistance of the battery cell under different battery cell health state conditions to the positive internal resistance of the battery cell under 100% battery cell health state, denoted as the third ratio a j ; j takes different positive numbers, representing different battery cell health states; and recording the ratio of the negative internal resistance of the battery cell under different battery cell health state conditions to the negative internal resistance of the battery cell under 100% battery cell health state, denoted as the fourth ratio b j ; and recording the ratio of the positive internal resistance of the battery cell under different battery cell health state conditions to the total internal resistance of the battery cell, denoted as the third ratio α j, Record the ratio of the internal resistance of the negative electrode of the battery cell to the total internal resistance of the battery cell under different battery cell health state conditions, denoted as the fourth ratio β j , α j + β j = 1.

[0076] In the embodiments of the present invention, by testing the internal resistance and internal resistance ratio of the battery cell under different battery cell health state conditions under a preset battery cell temperature condition, the internal resistance of the positive and negative electrodes of the battery cell under the current battery cell health state condition is determined according to the internal resistance and internal resistance ratio of the battery cell, and the relationship between the internal resistance of the positive and negative electrodes of the battery cell under different battery cell temperature conditions and different battery cell health states and the internal resistance of the positive and negative electrodes of the battery cell under the reference charging temperature condition is recorded, which is convenient for determining the corresponding relationship between the internal resistance of the positive and negative electrodes of the battery cell and the internal resistance of the battery cell under 100% battery cell health state according to the online real-time monitored battery cell temperature and battery cell health state during the use of the battery cell, and then quickly formulating the corresponding real-time charging strategy according to the corresponding relationship and the charging strategy under 100% battery cell health state.

[0077] Optionally, on the basis of the above embodiments, the embodiments of the present invention generate a stepped charging strategy under different battery cell temperatures and different battery cell health states, and the calculation process is as follows: Determine that the maximum current value Imax under the current battery cell temperature and battery cell health state SOH condition takes the value of min(Imax3, Imax4); Imax3 = SOH * min(Imax1, Imax2) / a j ; Imax4 = SOH * min(Imax1, Imax2) / b j ; Imax1 = I1 / a i ; Imax2 = I1 / b i ; or Imax takes the value of min(Imax5, Imax6) Imax5 = SOH * I1 / a ij ; Imax6 = SOH * I1 / b ij ;

[0078] Among them, I1 is the charging current under the reference charging strategy condition; SOH represents the current battery cell health state, a i is the ratio of the internal resistance of the positive electrode of the battery cell under the current battery cell temperature of i condition to the internal resistance of the positive electrode of the battery cell under the reference charging temperature condition under 100% battery cell health state; b i is the ratio of the internal resistance of the negative electrode of the battery cell under the current battery cell temperature of i condition to the internal resistance of the negative electrode of the battery cell under the reference charging temperature condition under 100% battery cell health state; a j is the ratio of the internal resistance of the positive electrode of the battery cell under the current battery cell health state of j condition to the internal resistance of the positive electrode of the battery cell under 100% battery cell health state under the preset battery cell temperature condition; b jis the ratio of the internal resistance of the positive electrode of the battery cell under the current battery cell health state of condition j to the internal resistance of the positive electrode of the battery cell under 100% battery cell health state under the preset battery cell temperature condition; a ij is the ratio of the internal resistance of the positive electrode of the battery cell under the condition that the current battery cell temperature is i and the current health state is j to the internal resistance of the positive electrode of the battery cell under the reference charging temperature and 100% battery cell health state; b ij is the ratio of the internal resistance of the positive electrode of the battery cell under the condition that the current battery cell temperature is i and the current health state is j to the internal resistance of the positive electrode of the battery cell under the reference charging temperature and 100% battery cell health state.

[0079] Among them, the measured values of the internal resistance of the positive electrode and the internal resistance of the negative electrode of the battery cell in different states can be directly measured. According to the measured values, the positive electrode internal resistance ratio and the negative electrode internal resistance ratio are calculated respectively. It is also possible to obtain the total internal resistance of the resistance in different states. According to the total internal resistance and the positive and negative electrode internal resistance ratios in the corresponding states, the internal resistance of the positive electrode and the internal resistance of the negative electrode corresponding to the total internal resistance are calculated respectively. Furthermore, the positive electrode internal resistance ratio and the negative electrode internal resistance ratio are calculated respectively according to the calculated internal resistance of the positive electrode and the internal resistance of the negative electrode.

[0080] The embodiment of the present invention determines the step charging strategy under the current battery cell temperature and the current battery cell health state according to at least one of the first mapping relationship, the second mapping relationship, and the third mapping relationship, which is convenient for the battery cell to quickly determine the matching real-time charging strategy according to the on-line real-time monitored battery cell temperature and the battery cell health state during use.

[0081] The following uses specific examples to describe the present invention in detail.

[0082] 1. The determination process of the BOL charging strategy at different battery cell temperatures is as follows:

[0083] c1. Charge the battery cell at different rates I1, I2, I3, I4, I5, I6, I7, I8, I9 at the reference temperature T1 using the trial current method. The lower limit of lithium for the negative electrode is 40 mV, and the charging SOC-negative electrode potential curve as shown in the appendix Figure 2 is obtained.

[0084] c2. According to the above charging SOC-negative electrode potential curve, select the current and the cut-off SOC at the lowest point of the negative electrode potential. Obtain the charging strategy at the reference temperature T1, that is, the charging strategy represented by the T1 curve in the appendix Figure 3 is obtained.

[0085] c3. Perform HPPC10s at the cut-off SOC for the battery cell at the reference temperature and the measured temperature. Obtain the DC internal resistance DCR at different cut-off SOCs.

[0086] c4. According to the relationship between the current and the internal resistance, obtain the charging current at the measured temperatures T2 and T3 at different cut-off SOCs.

[0087] c5. Verify the negative electrode potential of the three - temperature charging strategy. Modify the charging cut - off SOC of T3. The potential of the positive electrode vs. lithium should be less than 4.350 V. Obtain Figure 3 the charging strategies of the other two temperature BOLs as shown.

[0088] 2. The determination process of the BOL charging strategy under different state of health (SOH) is as follows:

[0089] d1. Charge the battery cell at different rates I1, I2, I3, I4, I5, I6, I7, I8, I9 at the reference temperature T1 using the trial - current method. The lower limit of the negative electrode vs. lithium is 40 mV. Obtain Figure 2 the charging SOC - negative electrode potential curve as attached.

[0090] d2. According to the above SOC - negative electrode potential curve, select the current and cut - off SOC at the lowest point of the negative electrode potential. Obtain the charging strategy at the reference temperature T1, that is, the charging strategy represented by the T1 curve as attached. Figure 3 the charging strategy represented by the T1 curve as attached.

[0091] d3. Conduct an internal resistance test HPPC10S on the battery cell at 100% SOH and the SOH to be measured at the T1 temperature reference. Obtain the DCR at different cut - off SOCs.

[0092] d4. According to the relationship between current and internal resistance, obtain the charging currents at different cut - off SOCs for the 85% SOH and EOL to be measured.

[0093] d5. Verify the negative electrode potential of the charging strategies for different SOHs. Modify the charging cut - off SOC for the SOH to be measured. The potential of the positive electrode vs. lithium should be less than 4.350 V. Obtain Figure 4 the charging curve as shown.

[0094] 3. Online test the DCR, temperature, and SOC of a certain electric vehicle battery cell. Its capacity decays and the internal resistance increases; there are BOL capacity - T - SOC - DCR curves and charging strategies in the existing stored data. Run the test software to obtain the internal resistance of the battery cell, obtain the internal resistance coefficient from the internal resistance, retrieve the stored data, and then obtain the SOC - charging current curve of the battery under the current state through the calculation module.

[0095] Specifically, taking the charging strategy at the T1 temperature under 100% battery cell health state formulated by the three - electrode trial - current method as the reference, that is, the T1 - SOC - maximum current curve as the reference. Offline three - electrode HPPC tests are conducted to collect the internal resistances of the positive and negative sides at different SOCs, different SOHs, and different temperatures of the battery cell. Online monitor the temperature, monitor the capacity decay of the battery cell, and conduct HPPC tests on the internal resistance of the battery cell. Calculate the ratio of the internal resistances of the positive and negative sides of the battery cell under the to - be - determined temperature and to - be - determined SOH to the internal resistance under the reference charging strategy conditions. This ratio is the charging current coefficient for the to - be - measured conditions. Generate the charging strategy online according to the coefficient.

[0096] The method for online adjusting the charging strategy provided by the embodiment of the present invention can output the charging strategy by integrating the offline data and the online monitoring data. Among them, the offline data is the charging strategy for different cell temperatures in BOL and the internal resistance and the ratio of the internal resistance of the positive and negative electrodes at different cell temperatures and different SOCs in the BOL stage. The online collected data is the internal resistance at different cell temperatures in the SOH state to be measured. The method for online adjusting the charging strategy provided by the embodiment of the present invention is applicable to different vehicle models, different system cells, and cells with different attenuation degrees. In this way, there is no need to update the software of the attenuated cells and input new charging strategies. Moreover, the charging strategy is updated as the SOH decreases, avoiding using high-rate charging in extreme emergencies such as rapid cell attenuation, sharp increase in cell internal resistance, and cell abuse. It can adjust in real time and switch to a small current in time to prevent the extreme situation from deteriorating further.

[0097] As Figure 5 shown, the embodiment of the present invention provides a device for online adjusting the charging strategy based on the internal resistance characteristics of the cell, including an information acquisition module, a data storage module, and a data processing module.

[0098] The information acquisition module is used to online monitor the cell temperature, the cell health state, the state of charge, and the internal resistance characteristics; among them, the internal resistance characteristics include at least one of the internal resistance of the positive electrode of the cell, the internal resistance of the negative electrode of the cell, and the total internal resistance of the cell; the data storage module is used to store at least one of the first mapping relationship, the second mapping relationship, and the third mapping relationship; among them, the first mapping relationship records the internal resistance relationship between different cell temperature conditions and the reference charging temperature condition under 100% cell health state; the second mapping relationship records the internal resistance relationship between different cell health state conditions under a preset temperature condition and 100% cell health state; the third mapping relationship records the internal resistance relationship between different cell temperature conditions and different cell health state conditions and the reference charging temperature condition and 100% cell health state; the data processing module is used to determine the step charging strategy of the current cell temperature and the current cell health state according to at least one of the first mapping relationship, the second mapping relationship, and the third mapping relationship.

[0099] Optionally, the generation process of the first mapping relationship stored in the data storage module includes: using the HPPC (Hybrid Pulse Power Characteristic) method to obtain the internal resistance characteristics of the three-electrode cell in BOL under 100% cell health state and the reference charging temperature T1; including the first internal resistance R of the positive electrode of the cell T1+ 、the first internal resistance R of the negative electrode T1- 、the first total internal resistance R of the cell T1 .

[0100] a2. The internal resistance characteristics of a three - electrode battery cell for obtaining BOL using the HPPC method under other battery cell temperature conditions (such as at temperature T2) than the reference charging temperature at 100% battery cell health state; including the second positive - electrode internal resistance R T2+ and the second negative - electrode internal resistance R T2- and the second total battery cell internal resistance R T2 .

[0101] a3. Calculate the ratio of the positive - electrode internal resistance of the battery cell under the to - be - determined temperature and SOC conditions to that under the reference charging temperature conditions (i.e., the first ratio a i ; i takes different positive numbers, representing different battery cell temperatures), and the ratio of the negative - electrode internal resistance (i.e., the second ratio b i ), as well as the proportion of the positive - electrode internal resistance (i.e., the first proportion α i ) and the proportion of the negative - electrode internal resistance (i.e., the second proportion β i ) at different battery cell temperatures. Among them, the positive - electrode internal resistance ratio a i = R T2+ / R T1+ ; the negative - electrode internal resistance ratio b i = R T2- / R T1- ; when the battery cell temperature i takes the T1 temperature, the positive - electrode internal resistance proportion α T1 = R T1+ / R T1 , and the negative - electrode internal resistance proportion β T1＝ R T1- / R T1 ; when the battery cell temperature i takes the T2 temperature, the positive - electrode internal resistance proportion α T2 = R T2+ / R T2 , and the negative - electrode internal resistance proportion β T2 = R T2- / R T2 .

[0102] In the embodiments of the present invention, by testing the positive and negative electrode internal resistances and the internal resistance proportions of the battery cell under different battery cell temperature conditions at 100% battery cell health state, and recording the relationships between the positive and negative electrode internal resistances of the battery cell under different battery cell temperature conditions and the reference charging temperature conditions, as well as the internal resistance proportions under different battery cell temperature conditions, it is convenient to determine the corresponding relationships between the positive and negative electrode internal resistances of the battery cell and the internal resistance of the battery cell under the reference temperature conditions according to the on - line real - time monitored battery cell temperature during the use of the battery cell, and then quickly formulate the corresponding real - time charging strategy according to the corresponding relationships and the reference charging strategy.

[0103] Optionally, the generation of the second mapping relationship stored in the data storage module includes: on - line testing the total battery cell internal resistance R T2 of the battery cell under the preset battery cell temperature (such as temperature T2), and according to the total battery cell internal resistance R T2and the internal resistance ratios under corresponding cell temperature conditions respectively determine the positive electrode internal resistance R of the cell under the current cell health state SOH2+ = R T2 *α T2 and the negative electrode internal resistance R SOH2- = R * β T2 ; Calculate the ratio of the positive electrode internal resistance of the cell under the SOH - T2 charging temperature condition to the positive electrode internal resistance of the cell under the T2 charging temperature condition and 100% cell health state (i.e., the third ratio a j ; j takes different positive numbers, representing different cell health states) a j = R SOH2+ / R T2+ and the ratio of the negative electrode internal resistance (i.e., the fourth ratio b j ) b j = R SOH2- / R T2- .

[0104] In the embodiment of the present invention, by testing the total internal resistance and internal resistance ratio of the cell under different cell health states under the preset cell temperature conditions, the positive and negative electrode internal resistances of the cell under the current cell health state conditions are determined according to the total internal resistance and internal resistance ratio of the cell, and the relationship between the positive and negative electrode internal resistances of the cell under different cell temperature conditions and different cell health states and the cell under the reference charging temperature condition is recorded, which is convenient for determining the corresponding relationship between the positive and negative electrode internal resistances of the cell and the internal resistance of the cell under the preset temperature condition and 100% cell health state according to the online real - time monitored cell temperature and cell health state during the use of the cell, and then quickly formulating the corresponding real - time charging strategy according to the corresponding relationship and the reference charging strategy.

[0105] Optionally, the generation of the third mapping relationship stored in the data storage module includes: obtaining the internal resistance characteristics of the three - electrode cell at BOL under the preset cell temperature condition and 100% cell health state by using the HPPC method; obtaining the internal resistance characteristics of the three - electrode cell at BOL under the preset cell temperature condition and different cell health states by using the HPPC method; using the second mapping relationship to record the following resistance relationships under the preset cell temperature condition: recording the ratio of the positive electrode internal resistance of the cell under different cell health state conditions to the positive electrode internal resistance of the cell under 100% cell health state, denoted as the third ratio a j ; j takes different positive numbers, representing different cell health states; and recording the ratio of the negative electrode internal resistance of the cell under different cell health state conditions to the negative electrode internal resistance of the cell under 100% cell health state, denoted as the fourth ratio b j ; and recording the ratio of the positive electrode internal resistance of the cell under different cell health state conditions to the total internal resistance of the cell, denoted as the third ratio α j , recording the ratio of the negative electrode internal resistance of the cell under different cell health state conditions to the total internal resistance of the cell, denoted as the fourth ratio β j , α j+β j = 1.

[0106] In an embodiment of the present invention, by testing the internal resistance and the internal resistance ratio of the battery cell under different battery cell health state conditions under a preset battery cell temperature condition, the positive and negative internal resistances of the battery cell under the current battery cell health state condition are determined according to the internal resistance and the internal resistance ratio of the battery cell, and the relationship between the positive and negative internal resistances of the battery cell under different battery cell temperature conditions and different battery cell health states and the positive and negative internal resistances of the battery cell under the reference charging temperature condition is recorded, which is convenient for determining the corresponding relationship between the positive and negative internal resistances of the battery cell and the internal resistance of the battery cell under 100% battery cell health state according to the on-line real-time monitored battery cell temperature and battery cell health state during the use of the battery cell, and then quickly formulating a corresponding real-time charging strategy according to the corresponding relationship and the charging strategy under 100% battery cell health state.

[0107] Optionally, the data processing module is specifically configured to: determine that the maximum current value Imax under the current battery cell temperature and battery cell health state SOH condition takes the value of min(Imax3, Imax4); Imax3 = SOH * min(Imax1, Imax2) / a j ; Imax4 = SOH * min(Imax1, Imax2) / b j ; Imax1 = I1 / a i ; Imax2 = I1 / b i ; or Imax takes the value of min(Imax5, Imax6) Imax5 = SOH * I1 / a ij ; Imax6 = SOH * I1 / b ij ;

[0108] Wherein, I1 is the charging current under the reference charging strategy condition; SOH represents the current battery cell health state, a i is the ratio of the positive internal resistance of the battery cell under the current battery cell temperature of i condition to the positive internal resistance of the battery cell under the reference charging temperature condition under 100% battery cell health state; b i is the ratio of the negative internal resistance of the battery cell under the current battery cell temperature of i condition to the negative internal resistance of the battery cell under the reference charging temperature condition under 100% battery cell health state; a j is the ratio of the positive internal resistance of the battery cell under the preset battery cell temperature condition and the current battery cell health state of j condition to the positive internal resistance of the battery cell under 100% battery cell health state; b j is the ratio of the positive internal resistance of the battery cell under the preset battery cell temperature condition and the current battery cell health state of j condition to the positive internal resistance of the battery cell under 100% battery cell health state; a ij is the ratio of the positive internal resistance of the battery cell under the current battery cell temperature of i and the current health state of j condition to the positive internal resistance of the battery cell under the reference charging temperature and 100% battery cell health state; b ijIt is the ratio of the internal resistance of the positive electrode of the battery cell under the condition that the current battery cell temperature is i degrees and the current state of health is j to the internal resistance of the positive electrode of the battery cell under the reference charging temperature and 100% state of health of the battery cell.

[0109] To solve the above technical problems, the present invention provides a computer-readable storage medium, including instructions that, when run on a computer, cause the computer to execute the method for online adjusting the charging strategy of the above technical solution.

[0110] To solve the above technical problems, the present invention provides a vehicle-mounted BMS system, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the method for online adjusting the charging strategy of the above technical solution. To solve the above technical problems, the present invention provides a vehicle, including the vehicle-mounted BMS system of the above technical solution.

[0111] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, the specific working processes of the above-described devices and units can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0112] In several embodiments provided by the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of units is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0113] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiments of the present invention.

[0114] In addition, the functional units in various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above integrated units can be implemented in the form of hardware or in the form of software functional units.

[0115] When the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs that can store program codes.

[0116] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for online adjusting a charging strategy, characterized in that, It includes the following steps: Online monitor the cell temperature, cell health state, state of charge, and internal resistance characteristics; wherein, the internal resistance characteristics include at least one of the positive electrode internal resistance of the cell, the negative electrode internal resistance of the cell, and the total internal resistance of the cell; Determine the step charging strategy under the current cell temperature and current cell health state according to at least one of the first mapping relationship, the second mapping relationship, and the third mapping relationship; Wherein, the first mapping relationship records the internal resistance relationship between different cell temperature conditions and the reference charging temperature condition under 100% cell health state; the second mapping relationship records the internal resistance relationship between different cell health state conditions under a preset temperature condition and 100% cell health state; the third mapping relationship records the internal resistance relationship between different cell temperature conditions and different cell health state conditions and the reference charging temperature condition and 100% cell health state; Determine the step charging strategy under the current cell temperature and the current cell health state according to at least one of the first mapping relationship, the second mapping relationship, and the third mapping relationship. The calculation process is as follows: Determine that the maximum current value Imax under the current cell temperature and the state of health (SOH) condition of the cell takes the value of min(Imax3, Imax4); Imax3 = SOH * min(Imax1, Imax2) / a j ; Imax4 = SOH * min(Imax1, Imax2) / b j ; Imax1 = I 1 / a i ; Imax2 = I 1 / b i ; or Imax takes the value of min(Imax5, Imax6). Imax5 = SOH * I 1 / a ij ; Imax6 = SOH * I 1 / b ij ; Among them, I1 is the charging current under the reference charging strategy condition; SOH represents the current cell health state, and a i is the ratio of the internal resistance of the positive electrode of the cell at the current cell temperature of i to the internal resistance of the positive electrode of the cell under the reference charging temperature condition when the cell health state is 100%; b i is the ratio of the internal resistance of the negative electrode of the cell at the current cell temperature of i to the internal resistance of the negative electrode of the cell under the reference charging temperature condition when the cell health state is 100%; a j is the ratio of the internal resistance of the positive electrode of the cell at the current cell health state of j to the internal resistance of the positive electrode of the cell in the 100% cell health state under the preset cell temperature condition; b j is the ratio of the internal resistance of the positive electrode of the cell at the current cell health state of j to the internal resistance of the positive electrode of the cell in the 100% cell health state under the preset cell temperature condition; a ij is the ratio of the internal resistance of the positive electrode of the battery cell under the condition that the current battery cell temperature is i and the current state of health is j to the internal resistance of the positive electrode of the battery cell at the reference charging temperature and with 100% state of health of the battery cell; b ij is the ratio of the internal resistance of the positive electrode of the battery cell under the condition that the current battery cell temperature is i degrees and the current state of health is j to the internal resistance of the positive electrode of the battery cell at the reference charging temperature and with 100% state of health of the battery cell.

2. The method for online adjusting a charging strategy according to claim 1, wherein It further includes the step of pre-generating the first mapping relationship, specifically including: Use the HPPC hybrid power pulse characteristic method to obtain the internal resistance characteristics of the three-electrode cell of the BOL charging strategy under 100% cell health state and the reference charging temperature; Use the HPPC hybrid power pulse characteristic method to obtain the internal resistance characteristics of the three-electrode cell of the BOL charging strategy under 100% cell health state and other cell temperature conditions other than the reference charging temperature; Use the first mapping relationship to record the following resistance relationship under 100% cell health state: Record the ratio of the internal resistance of the positive electrode of the battery cell under different battery cell temperature conditions to the internal resistance of the positive electrode of the battery cell under the reference charging temperature condition, denoted as the first ratio a i ; i takes different positive numbers, representing different battery cell temperatures; and recording the ratio of the internal resistance of the negative electrode of the battery cell under different battery cell temperature conditions to the internal resistance of the negative electrode of the battery cell under the reference charging temperature condition, denoted as the second ratio b i , And record the ratio of the internal resistance of the positive electrode of the battery cell to the total internal resistance of the battery cell at different battery cell temperatures, denoted as the first ratio α i , record the ratio of the internal resistance of the negative electrode of the battery cell to the total internal resistance of the battery cell at different battery cell temperatures, denoted as the second ratio β i , α i +β i = 1.

3. The method for online adjusting the charging strategy according to claim 2, characterized in that It further includes the step of pre-generating the second mapping relationship, specifically including: Use the HPPC hybrid power pulse characteristic method to obtain the internal resistance characteristics of the three-electrode cell of the BOL charging strategy under the preset cell temperature condition and 100% cell health state; Use the HPPC hybrid power pulse characteristic method to obtain the internal resistance characteristics of the three-electrode cell of the BOL charging strategy under the preset cell temperature condition and different cell health states; Use the second mapping relationship to record the following resistance relationship under the preset cell temperature condition: Record the ratio of the internal resistance of the positive electrode of the battery cell under different battery cell health state conditions to the internal resistance of the positive electrode of the battery cell under 100% battery cell health state, denoted as the third ratio a j ; j takes different positive numbers, representing different battery cell health states; and record the ratio of the internal resistance of the negative electrode of the battery cell under different battery cell health state conditions to the internal resistance of the negative electrode of the battery cell under 100% battery cell health state, denoted as the fourth ratio b j ; And record the ratio of the internal resistance of the positive electrode of the battery cell to the total internal resistance of the battery cell under different battery cell health state conditions, denoted as the third ratio α j , record the ratio of the internal resistance of the negative electrode of the battery cell to the total internal resistance of the battery cell under different battery cell health state conditions, denoted as the fourth ratio β j , α j +β j = 1.

4. The method for online adjusting a charging strategy according to claim 1, wherein It further includes the step of pre-generating the third mapping relationship, specifically including: Use the HPPC hybrid power pulse characteristic method to obtain the internal resistance characteristics of the three-electrode cell of the BOL charging strategy under the reference charging temperature condition and 100% cell health state; Use the HPPC hybrid power pulse characteristic method to obtain the internal resistance characteristics of the three-electrode cell of the BOL charging strategy under different cell temperature conditions and different cell health states; Use the third mapping relationship to record the following resistance relationship: Record the ratio of the internal resistance of the positive electrode of the battery cell under different battery cell temperatures and different state-of-health conditions to the internal resistance of the positive electrode of the battery cell at the reference charging temperature and 100% state-of-health of the battery cell, denoted as the fifth ratio a ij ; ij takes different positive numbers, representing different battery cell temperatures and different states-of-health of the battery cell; and record the ratio of the internal resistance of the negative electrode of the battery cell under different battery cell temperatures and different battery cell health state conditions to the internal resistance of the negative electrode of the battery cell under the reference charging temperature and 100% battery cell health state, denoted as the sixth ratio b ij ; And record the ratio of the internal resistance of the positive electrode of the battery cell to the total internal resistance of the battery cell under different battery cell temperature and different battery cell health state conditions, denoted as the fifth ratio α ij , record the ratio of the internal resistance of the negative electrode of the battery cell to the total internal resistance of the battery cell under different battery cell health state conditions, denoted as the sixth ratio β ij , α ij +β ij = 1.

5. An apparatus for online adjusting a charging strategy, characterized in that, It includes an information acquisition module, a data storage module, and a data processing module; The information acquisition module is used to online monitor the cell temperature, cell health state, state of charge, and internal resistance characteristics; wherein, the internal resistance characteristics include at least one of the positive electrode internal resistance of the cell, the negative electrode internal resistance of the cell, and the total internal resistance of the cell; The data storage module is used to store at least one of the first mapping relationship, the second mapping relationship, and the third mapping relationship; wherein, the first mapping relationship records the internal resistance relationship between different cell temperature conditions and the reference charging temperature condition under 100% cell health state; the second mapping relationship records the internal resistance relationship between different cell health state conditions and the internal resistance under 100% cell health state under a preset temperature condition; the third mapping relationship records the internal resistance relationship between different cell temperature conditions and different cell health state conditions and the reference charging temperature condition and 100% cell health state; The data processing module is used to determine the step charging strategy of the current cell temperature and the current cell health state according to at least one of the first mapping relationship, the second mapping relationship, and the third mapping relationship; The data processing module is specifically used for: determining that the maximum current value Imax under the current cell temperature and the state of health (SOH) of the cell takes the value of min(Imax3, Imax4); Imax3 = SOH * min(Imax1, Imax2) / a j ; Imax4 = SOH * min(Imax1, Imax2) / b j ; Imax1 = I1 / a i ; Imax2 = I1 / b i ; or Imax takes the value of min(Imax5, Imax6), Imax5 = SOH * I1 / a ij ; Imax6 = SOH * I1 / b ij ; Among them, I1 is the charging current under the reference charging strategy condition; SOH represents the current cell health state, and a i is the ratio of the internal resistance of the positive electrode of the cell at the current cell temperature of i to the internal resistance of the positive electrode of the cell under the reference charging temperature condition when the cell health state is 100%; b i is the ratio of the internal resistance of the negative electrode of the cell at the current cell temperature of i to the internal resistance of the negative electrode of the cell under the reference charging temperature condition when the cell health state is 100%; a j is the ratio of the internal resistance of the positive electrode of the cell at the current cell health state of j to the internal resistance of the positive electrode of the cell in the 100% cell health state under the preset cell temperature condition; b j is the ratio of the internal resistance of the positive electrode of the cell at the current cell health state of j to the internal resistance of the positive electrode of the cell in the 100% cell health state under the preset cell temperature condition; a ij is the ratio of the internal resistance of the positive electrode of the battery cell under the condition that the current battery cell temperature is i and the current state of health is j to the internal resistance of the positive electrode of the battery cell at the reference charging temperature and 100% state of health of the battery cell; b ij is the ratio of the internal resistance of the positive electrode of the battery cell under the condition that the current battery cell temperature is i degrees and the current state of health is j to the internal resistance of the positive electrode of the battery cell at the reference charging temperature and 100% state of health of the battery cell.

6. A computer-readable storage medium, comprising instructions, characterized in that, When the instruction runs on the computer, the computer is caused to execute the online adjustment charging strategy method according to any one of claims 1 to 4.

7. A vehicle-mounted BMS system, characterized in that, It includes a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that when the processor executes the program, it implements the method of online adjustment of the charging strategy according to any one of claims 1 to 4.

8. A vehicle, characterized in that, It includes the in-vehicle BMS system according to claim 7.

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