Method for determining cb value of lithium battery, controller, medium, bms and electrical equipment

Abstract

The application discloses a lithium battery CB value determination method, a controller, a medium, a BMS and an electrical equipment, and relates to the technical field of lithium batteries. The method can obtain the charge-discharge data of a lithium battery, current first dV / dQ data, and second dV / dQ data of the lithium battery when the lithium battery is shipped. Then, the method can accurately determine the cathode loss capacity value and the anode loss capacity value of the lithium battery based on the charge-discharge data, the first dV / dQ data and the second dV / dQ data, and then determine the CB value of the lithium battery in use based on the cathode loss capacity value and the anode loss capacity value.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium batteries, and particularly relates to a CB value determination method for a lithium battery, a controller, a medium, a BMS and an electrical equipment. BACKGROUND

[0002] The overage factor of a lithium battery, also known as a cell balance (CB) value, is a core parameter for determining the safety, cycle life and energy density of the battery. Therefore, it is particularly important to determine the CB value of the lithium battery in its entire life cycle.

[0003] However, the CB value of a fresh lithium battery can only be evaluated at present, that is, the CB value of the lithium battery is evaluated when the lithium battery has not been subjected to charge-discharge cycles. Therefore, there is an urgent need for a method for determining the CB value of a lithium battery in use. SUMMARY

[0004] The present application provides a CB value determination method for a lithium battery, a controller, a medium, a BMS and an electrical equipment, which can determine the CB value of the lithium battery in use.

[0005] In a first aspect, a CB value determination method for a lithium battery is provided, and the method comprises:

[0006] obtaining charge-discharge data of the lithium battery, current first dV / dQ data and second dV / dQ data of the lithium battery when it is shipped;

[0007] determining a cathode loss capacity value and an anode loss capacity value of the lithium battery based on the charge-discharge data, the first dV / dQ data and the second dV / dQ data;

[0008] determining a CB value of the lithium battery in use based on the cathode loss capacity value and the anode loss capacity value.

[0009] The method can obtain the charge-discharge data of the lithium battery, the current first dV / dQ data and the second dV / dQ data of the lithium battery when it is shipped. Subsequently, the method can accurately determine the cathode loss capacity value and the anode loss capacity value of the lithium battery based on the charge-discharge data, the first dV / dQ data and the second dV / dQ data, and then determine the CB value of the lithium battery in use based on the cathode loss capacity value and the anode loss capacity value.

[0010] Optionally, the lithium battery comprises an electrolyte, and determining the cathode loss capacity value and the anode loss capacity value of the lithium battery based on the charge-discharge data, the first dV / dQ data and the second dV / dQ data comprises:

[0011] determine a total charge loss capacity value and a total discharge loss capacity value of the lithium battery based on the charge and discharge data;

[0012] determine a first total loss capacity value, a lithium loss total value and a second total loss capacity value of the lithium battery based on the first dV / dQ data and the second dV / dQ data, wherein the first total loss capacity value is a sum of the cathode loss capacity value and the anode loss capacity value, the second total loss capacity value is a sum of the cathode loss capacity value and a target lithium loss value, and the target lithium loss value is caused by the electrolyte decomposition and lithium ion deposition in the electrolyte;

[0013] determine the cathode loss capacity value and the anode loss capacity value of the lithium battery based on the total charge loss capacity value, the total discharge loss capacity value, the first total loss capacity value, the second total loss capacity value and the lithium loss total value.

[0014] Optionally, the first dV / dQ data is represented by a first dV / dQ curve, and the second dV / dQ data is represented by a second dV / dQ curve; determining the first total loss capacity value, the lithium loss total value and the second total loss capacity value of the lithium battery based on the first dV / dQ data and the second dV / dQ data comprises:

[0015] obtaining a lateral distance reduction amount of a first peak and a second peak in the first dV / dQ curve compared to the second dV / dQ curve, a lateral position change amount of the second peak, and an intensity reduction amount of a third peak;

[0016] determining the first total loss capacity value of the lithium battery based on the lateral distance reduction amount, wherein the first total loss capacity value is proportional to the lateral distance reduction amount;

[0017] determining the lithium loss total value of the lithium battery based on the lateral position change amount, wherein the lithium loss total value is proportional to the lateral position change amount;

[0018] determining the second total loss capacity value of the lithium battery based on the intensity reduction amount, wherein the second total loss capacity value is proportional to the intensity reduction amount;

[0019] wherein the first peak and the second peak are both associated with the first total loss capacity of the lithium battery, the second peak is further associated with the lithium loss total value of the lithium battery, and the third peak is associated with the second total loss capacity of the lithium battery.

[0020] Optionally, obtaining the lateral distance reduction amount of the first peak and the second peak in the first dV / dQ curve compared to the second dV / dQ curve, the lateral position change amount of the second peak, and the intensity reduction amount of the third peak comprises:

[0021] from the first dV / dQ curve, a first lateral distance between the first peak and the second peak, a first lateral position of the second peak, and a first peak value of the third peak are obtained;

[0022] a second lateral distance between the first peak and the second peak, a second lateral position of the second peak, and a second peak value of the third peak are obtained, the second lateral distance, the second lateral position and the second peak value being determined based on the second dV / dQ curve;

[0023] based on a difference between the second lateral distance and the first lateral distance, a lateral distance reduction amount of the first peak and the second peak is determined;

[0024] based on a difference between the second lateral position and the first lateral position, a lateral position change amount of the second peak is determined;

[0025] based on a difference between the second peak value and the first peak value, an intensity reduction amount of the third peak is determined.

[0026] Optionally, based on the charge-discharge data, a total charge loss capacity value and a total discharge loss capacity value of the lithium battery are determined, comprising:

[0027] based on the charge-discharge data, charge loss capacity values and discharge loss capacity values of the lithium battery in each charge-discharge cycle up to the present are obtained;

[0028] based on a sum of the charge loss capacity values of the lithium battery in a plurality of the charge-discharge cycles up to the present, the total charge loss capacity value of the lithium battery is determined;

[0029] based on a sum of the discharge loss capacity values of the lithium battery in a plurality of the charge-discharge cycles up to the present, the total discharge loss capacity value of the lithium battery is determined.

[0030] Optionally, based on the charge-discharge data, charge loss capacity values and discharge loss capacity values of the lithium battery in each charge-discharge cycle up to the present are obtained, comprising:

[0031] based on the charge-discharge data, charge capacity values and discharge capacity values of the lithium battery in each charge-discharge cycle up to the present are obtained;

[0032] for each charge-discharge cycle, based on a difference between the discharge capacity value in the previous charge-discharge cycle and the charge capacity value in the present charge-discharge cycle, a charge loss capacity value in the present charge-discharge cycle is determined;

[0033] And, based on the difference between the charging capacity value and the discharging capacity value in this charging and discharging cycle, a discharging loss capacity value in this charging and discharging cycle is determined.

[0034] Optionally, based on the total charging loss capacity value, the total discharging loss capacity value, the first total loss capacity value, the second total loss capacity value and the total lithium loss value, a cathode loss capacity value and an anode loss capacity value of the lithium battery are determined, comprising:

[0035] The total charging loss capacity value, the total discharging loss capacity value, the first total loss capacity value, the second total loss capacity value and the total lithium loss value are input into a loss capacity calculation model to obtain a first loss component value, a second loss component value, a third loss component value and a fourth loss component value output by the loss capacity calculation model;

[0036] Based on the sum of the first loss component value and the second loss component value, a cathode loss capacity value of the lithium battery is determined.

[0037] Based on the sum of the third loss component value and the fourth loss component value, an anode loss capacity value of the lithium battery is determined.

[0038] The first loss component value is a capacity loss value caused by structural damage of the cathode, and the second loss component value is a capacity loss value caused by polarization of the cathode; the third loss component value is a capacity loss value caused by structural damage of the anode, and the fourth loss component value is a capacity loss value caused by polarization of the anode.

[0039] Optionally, the loss capacity calculation model comprises:

[0040] A first functional relationship in which the first total loss capacity varies with the first loss component, the second loss component, the third loss component and the fourth loss component;

[0041] A second functional relationship in which the total lithium loss varies with the target lithium loss, the second loss component and the fourth loss component;

[0042] A third functional relationship in which the second total loss capacity varies with the first loss component, the second loss component and the target lithium loss;

[0043] A fourth functional relationship in which the total charging loss capacity varies with the second loss component and the third loss component;

[0044] A fifth functional relationship in which the total discharging loss capacity varies with the target lithium loss, the first loss component and the fourth loss component;

[0045] The first total loss capacity value, the lithium loss total value, the second total loss capacity value, the charging total loss capacity value and the discharging total loss capacity value are input into a loss capacity calculation model to obtain first, second, third and fourth loss component values output by the loss capacity calculation model, including:

[0046] The first total loss capacity value is input into the first function relationship, the lithium loss total value is input into the third function relationship, the second total loss capacity value is input into the third function relationship, the charging total loss capacity value is input into the fourth function relationship, and the discharging total loss capacity value is input into the fifth function relationship to obtain the first to fourth loss component values.

[0047] Optionally, the lithium battery comprises a cathode and an anode; and based on the cathode loss capacity value and the anode loss capacity value, a CB value of the lithium battery in use is determined, including:

[0048] Based on the cathode loss capacity value and the anode loss capacity value, a target remaining capacity of the lithium battery is determined, the target remaining capacity being a larger one of a maximum remaining capacity value of the cathode and a maximum remaining capacity value of the anode;

[0049] Based on the target remaining capacity and a full capacity of the lithium battery at present, the CB value of the lithium battery in use is determined.

[0050] Optionally, in a case where the target remaining capacity is the maximum remaining capacity value of the cathode, the CB value is proportional to a ratio of the full capacity to the target remaining capacity;

[0051] In a case where the target remaining capacity is the maximum remaining capacity value of the anode, the CB value is proportional to a ratio of the target remaining capacity to the full capacity.

[0052] Optionally, based on the cathode loss capacity value and the anode loss capacity value, the target remaining capacity of the lithium battery is determined, including:

[0053] An initial maximum capacity value of the cathode and an initial maximum capacity value of the anode are obtained;

[0054] Based on a difference between the initial maximum capacity value of the cathode and the cathode loss capacity value, a maximum remaining capacity value of the cathode is determined, and based on a difference between the initial maximum capacity value of the anode and the anode loss capacity value, a maximum remaining capacity value of the anode is determined;

[0055] The greater value between the maximum remaining capacity value of the cathode and the maximum remaining capacity value of the anode is determined as the target remaining capacity of the lithium battery.

[0056] Optionally, before determining the CB value of the lithium battery in use based on the target remaining capacity and the current full capacity of the lithium battery, the method further comprises:

[0057] The smaller value between the maximum remaining capacity value of the cathode and the maximum remaining capacity value of the anode is determined as the current full capacity of the lithium battery.

[0058] Therefore, the full capacity can be quickly obtained, and the determination efficiency of the CB value can be improved.

[0059] Optionally, before determining the CB value of the lithium battery in use based on the target remaining capacity and the current full capacity of the lithium battery, the method further comprises:

[0060] Obtaining the current non-polarization discharge curve of the lithium battery;

[0061] Based on the non-polarization discharge curve, obtaining the current full capacity of the lithium battery.

[0062] Therefore, the accuracy of obtaining the full capacity can be improved, and the determination accuracy of the CB value is improved.

[0063] In a second aspect, a controller is provided, and the controller comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and when the processor executes the computer program, the method in the first aspect is implemented.

[0064] In a third aspect, a computer readable storage medium is provided, and the computer readable storage medium stores a computer program, and when the computer program is executed by a processor, the method in the first aspect is implemented.

[0065] In a fourth aspect, a computer program product is provided, and the computer program product comprises a computer program or computer instructions, and when the computer program or the computer instructions are executed by a processor, the method in the first aspect is implemented.

[0066] In a fifth aspect, a BMS is provided, and the BMS comprises the controller in the second aspect.

[0067] In a sixth aspect, an electrical appliance is provided, and the electrical appliance comprises the BMS in the fifth aspect.

[0068] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0069] Figure 1 This is a flowchart of a method for determining the CB value of a lithium battery according to an embodiment of this application;

[0070] Figure 2 This is a flowchart of another method for determining the CB value of a lithium battery provided in an embodiment of this application;

[0071] Figure 3 This is a comparative schematic diagram of the non-polarized discharge curve of a lithium battery provided in the embodiments of this application;

[0072] Figure 4 This is a schematic diagram illustrating the capacity change of a lithium battery during a charge-discharge cycle, as provided in an embodiment of this application.

[0073] Figure 5 Based on Figure 3 The diagram shows the dV / dQ curve obtained from the non-polarized discharge curve.

[0074] Figure 6 This is a flowchart of a method for determining the CB value of a lithium battery during use based on the cathode loss capacity value and anode loss capacity value of the lithium battery, provided in an embodiment of this application.

[0075] Figure 7 This is a schematic diagram of the anode capacity change curve, cathode capacity change curve, and polarization-free discharge curve of a fresh lithium battery provided in the embodiments of this application;

[0076] Figure 8 This is a schematic diagram illustrating one of the causes of capacity loss in lithium batteries, provided in an embodiment of this application.

[0077] Figure 9 This is a schematic diagram of the anode capacity change curve, cathode capacity change curve, and non-polarized discharge curve of a lithium battery during use, provided in an embodiment of this application.

[0078] Figure 10 This application provides a schematic diagram of the curves relating anode capacity to cathode capacity.

[0079] Figure 11 This application provides a schematic diagram of a stacked wafer design.

[0080] Figure 12 This application provides another schematic diagram of a stacked wafer design.

[0081] Figure 13is a schematic diagram of another lamination design provided by an embodiment of the present application;

[0082] Figure 14 is a schematic diagram of another lamination design provided by an embodiment of the present application;

[0083] Figure 15 is a schematic diagram of another lamination design provided by an embodiment of the present application;

[0084] Figure 16 is a schematic diagram of a structure of a controller provided by an embodiment of the present application. DETAILED DESCRIPTION

[0085] Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein the same or like reference numerals are used throughout the drawing figures to refer to the same or like elements or to like functions of like elements. The embodiments described below are merely exemplary for the purposes of explanation and are not intended to limit the application, which is limited only by the claims and equivalents thereof.

[0086] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the use of the terms "including," "comprising," "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

[0087] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the technical features indicated. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0088] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to each other. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0089] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0090] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0091] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above-mentioned terms in the embodiments of the present application can be understood according to the specific circumstances.

[0092] If not specifically stated, all embodiments and optional embodiments of the present application can be combined to form new technical solutions. If not specifically stated, all technical features and optional technical features of the present application can be combined to form new technical solutions. If not specifically stated, all steps of the present application can be performed in sequence, or randomly, preferably in sequence. For example, the method comprises steps (a) and (b), which means that the method can comprise steps (a) and (b) in sequence, or steps (b) and (a) in sequence. For example, it is mentioned that the method can further comprise step (c), which means that step (c) can be added to the method in any order, for example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0093] The CB value of the lithium battery is the ratio of the anode capacity to the cathode capacity of the lithium battery, also known as the N / P (Negative / Positive) value. The CB value of the lithium battery has a significant impact on the performance of the battery cell. For example, different CB values will cause differences in the capacity of the positive electrode material and the negative electrode material; will affect the full charging time of the battery, especially the charging time of the constant voltage stage; will cause differences in the energy density and the first coulomb efficiency of the battery; and will also cause significant differences in the performance of the battery in high-voltage cycling, floating, storage, and heat box testing.

[0094] Therefore, it is crucial to determine the CB value of the lithium battery throughout its life cycle. However, currently, the CB value of the lithium battery is evaluated when the lithium battery is not subjected to charging and discharging cycles. There are few reports on methods for determining the CB value of the lithium battery during its calendar use.

[0095] Therefore, the embodiments of the present application provide a method for determining CB value of a lithium battery, which is applied to a BMS of the lithium battery. Referring to Figure 1 The method comprises the following steps:

[0096] In step 101, the BMS acquires the charge-discharge data of the lithium battery, the first dV / dQ data of the lithium battery, and the second dV / dQ data of the lithium battery when the lithium battery is manufactured.

[0097] With the use of the lithium battery (such as calendar use and cycle use), the cathode capacity and the anode capacity of the lithium battery will be lost. Therefore, the current cathode loss capacity value and the anode loss capacity value of the lithium battery need to be determined to determine the actual capacity of the current anode (i.e. the maximum remaining capacity value) and the maximum remaining capacity value of the cathode (i.e. the cathode capacity), so as to accurately calculate the current CB value of the lithium battery.

[0098] After the cathode capacity and the anode capacity of the lithium battery are lost, the dV / dQ data of the lithium battery will change, and the charge capacity and the discharge capacity of the lithium battery will also be lost. The change of the dV / dQ data and the total loss capacity of the charge and the total loss capacity of the discharge of the lithium battery until the current lithium battery can be used to infer the current cathode loss capacity value and the anode loss capacity value of the lithium battery.

[0099] Therefore, when the BMS needs to determine the CB value of the lithium battery in use, the BMS can acquire the charge-discharge data of the lithium battery, the first dV / dQ data of the lithium battery, and the second dV / dQ data of the lithium battery when the lithium battery is manufactured.

[0100] In step 102, the BMS determines the cathode loss capacity value and the anode loss capacity value of the lithium battery based on the charge-discharge data, the first dV / dQ data, and the second dV / dQ data.

[0101] The BMS can determine the total loss capacity value of the charge and the total loss capacity value of the discharge of the lithium battery based on the charge-discharge data, and determine the first total loss capacity value, the total lithium loss value, and the second total loss capacity value of the lithium battery based on the first dV / dQ data and the second dV / dQ data. Then, the BMS can determine the cathode loss capacity value and the anode loss capacity value of the lithium battery based on the total loss capacity value of the charge, the total loss capacity value of the discharge, the first total loss capacity value, the second total loss capacity value, and the total lithium loss value.

[0102] The first total loss capacity value is the sum of the cathode loss capacity value and the anode loss capacity value, and the second total loss capacity value is the sum of the cathode loss capacity value and the target lithium loss value in the electrolyte of the lithium battery.

[0103] In step 103, the BMS determines the CB value of the lithium battery in use based on the cathode loss capacity value and the anode loss capacity value.

[0104] In the embodiment of the present application, the BMS can determine the target residual capacity of the lithium battery based on the cathode loss capacity value and the anode loss capacity value. The target residual capacity is the larger one of the maximum residual capacity value of the cathode and the maximum residual capacity value of the anode. Then, the BMS can determine the CB value of the lithium battery in use based on the target residual capacity and the current full capacity of the lithium battery.

[0105] To sum up, the embodiment of the present application provides a method for determining the CB value of a lithium battery. The method can obtain the charge-discharge data of the lithium battery, the current first dV / dQ data, and the second dV / dQ data of the lithium battery when it is shipped. Subsequently, the method can accurately determine the cathode loss capacity value and the anode loss capacity value of the lithium battery based on the charge-discharge data, the first dV / dQ data, and the second dV / dQ data, and then determine the CB value of the lithium battery in use based on the cathode loss capacity value and the anode loss capacity value.

[0106] Figure 2 is another method for determining the CB value of a lithium battery provided by the embodiment of the present application, which can be applied to the BMS of the lithium battery. Referring to Figure 2 , the method comprises:

[0107] Step 201: Obtain the charge-discharge data of the lithium battery, the current first dV / dQ data, and the second dV / dQ data of the lithium battery when it is shipped.

[0108] The charge-discharge data can reflect the charge capacity value and the discharge capacity value of the lithium battery in each charge-discharge cycle, and the charge-discharge data can be represented by a charge-discharge curve. The first dV / dQ data can be represented by a first dV / dQ curve. The second dV / dQ data can be represented by a second dV / dQ curve, and is the dV / dQ data of the lithium battery when it is not subjected to charge-discharge cycles, i.e., the dV / dQ data of a fresh lithium battery.

[0109] The second dV / dQ data can be pre-stored by the BMS. The charge-discharge data of the lithium battery can be pre-recorded by the BMS. Specifically, during the cyclic use of the lithium battery, the BMS can record the change of the voltage with the capacity when the battery is discharged from the full charge state (i.e., the charge cut-off voltage) to the discharge cut-off voltage, and the change of the voltage with the capacity when the battery is charged from the discharge cut-off voltage to the full charge state, thereby obtaining the charge-discharge data of the lithium battery. The capacity when the battery is discharged to the discharge cut-off voltage each time is the discharge capacity value of the lithium battery at this time. The capacity when the battery is charged to the full charge state each time is the charge capacity value of the lithium battery at this time.

[0110] For the first dV / dQ data, the BMS can first obtain the current non-polarization discharge curve (which can also be referred to as a small rate discharge curve) of the lithium battery, and then differentiates the non-polarization discharge curve, so as to obtain the first dV / dQ curve of the lithium battery. That is, the first dV / dQ curve is the differentiation result of the current non-polarization discharge curve. The non-polarization discharge curve refers to a curve of voltage change with capacity recorded when the lithium battery is discharged at a very low discharge rate (usually less than C / 10, such as C / 20 or C / 50). C represents the discharge rate.

[0111] In the embodiments of the present application, the CB value of the lithium battery is the ratio of the anode capacity to the cathode capacity of the lithium battery. However, with the use (such as calendar use and cycle use) of the lithium battery, the cathode capacity and the anode capacity of the lithium battery will be lost. Therefore, the current cathode lost capacity value and the anode lost capacity value of the lithium battery need to be determined to determine the maximum residual capacity value of the current anode and the maximum residual capacity value of the cathode, so as to accurately calculate the current CB value of the lithium battery.

[0112] After the cathode capacity and the anode capacity of the lithium battery are lost, the current non-polarization discharge curve of the lithium battery will be significantly different from the non-polarization discharge curve at the time of factory shipment, thereby causing the dV / dQ curve of the lithium battery to change; and will also cause the charge capacity and the discharge capacity of the lithium battery to be lost. Moreover, the change of the first dV / dQ curve of the lithium battery compared with the second dV / dQ curve, and the total lost capacity of charging and the total lost capacity of discharging of the lithium battery up to the present, can be used to determine the current cathode lost capacity value and the anode lost capacity value of the lithium battery.

[0113] Therefore, when the BMS needs to determine the CB value of the lithium battery in use, the BMS can obtain the charge-discharge data of the lithium battery, the current first dV / dQ data, and the second dV / dQ data of the lithium battery at the time of factory shipment.

[0114] In the embodiments of the present application, the BMS can periodically obtain the CB value of the lithium battery in use. Correspondingly, the BMS can periodically obtain the charge-discharge data of the lithium battery, the current first dV / dQ data, and the second dV / dQ data of the lithium battery at the time of factory shipment. Alternatively, the BMS can obtain the charge-discharge data, the current first dV / dQ data, and the second dV / dQ data of the lithium battery at the time of factory shipment in response to a determination instruction for the CB value.

[0115] Figure 3 A comparison diagram of non-polarization discharge curves of a lithium battery is shown. The lithium battery is an NCM811 / Gr system lithium battery. From the left to the right, the discharge rate is gradually reduced. Figure 3It can be seen that, compared with the discharge capacity value corresponding to the end point of the non-polarization discharge curve in the initial state, the discharge capacity value corresponding to the end point of the non-polarization discharge curve of the lithium battery after calendar use is smaller. That is, the capacity of the lithium battery after use will decay. The initial state refers to the state before the charge and discharge cycle occurs.

[0116] In step 202, the total charge loss capacity value and the total discharge loss capacity value of the lithium battery are determined based on the charge and discharge data of the lithium battery.

[0117] In the embodiments of the present application, the process of step 202 performed by the BMS can include:

[0118] In step S1, the charge loss capacity value and the discharge loss capacity value of the lithium battery in each charge and discharge cycle up to the present are obtained based on the charge and discharge data of the lithium battery.

[0119] Figure 4 A schematic diagram of the capacity change of a lithium battery in a charge and discharge cycle process is shown. Figure 4 In the initial state, represents the discharge charge discharge, represents the charge loss capacity value, represents the discharge loss capacity value. From Figure 4 It can be seen that, after each charge and discharge cycle, the charge capacity value and the discharge capacity value of the lithium battery will be lost.

[0120] Based on this, the BMS can obtain the charge capacity value and the discharge capacity value of the lithium battery in each charge and discharge cycle from the factory up to the present multiple charge and discharge cycles based on the charge and discharge data. Then, as Figure 4 shown, for each charge and discharge cycle, the BMS can determine the charge loss capacity value in this charge and discharge cycle based on the difference between the discharge capacity value in the previous charge and discharge cycle (i.e., the discharge capacity value when the voltage reaches the discharge cutoff voltage) and the charge capacity value in this charge and discharge cycle (i.e., the charge capacity value when the voltage reaches the charge cutoff voltage). And the BMS can determine the discharge loss capacity value in this charge and discharge cycle based on the difference between the charge capacity value and the discharge capacity value in this charge and discharge cycle.

[0121] Alternatively, the charge loss capacity value in each charge and discharge cycle can be the difference between the discharge capacity value in the previous charge and discharge cycle and the charge capacity value in this charge and discharge cycle, or the product of the difference and a preset coefficient. For example, the charge loss capacity value in each charge and discharge cycle is the difference, i.e., the charge loss capacity value in the i-th charge and discharge cycle is satisfies: =D (i-1) ​- C i . wherein D (i-1) is the discharge capacity value in the i-1th charge-discharge cycle, C i is the charge capacity value in the ith charge-discharge cycle. i is an integer greater than or equal to 1 and less than or equal to the total number of charge-discharge cycles up to the present. The preset coefficient can be pre-stored by the BMS, such as 0.999.

[0122] The discharge loss capacity value in each charge-discharge cycle can be the difference between the charge capacity value in the charge-discharge cycle and the discharge capacity value in the charge-discharge cycle, or the product of the difference and a preset coefficient. For example, the discharge loss capacity value in each charge-discharge cycle is the difference, i.e., the discharge loss capacity value in the ith charge-discharge cycle is satisfies: =C i - D i .

[0123] It should be noted that the method provided in the embodiments of the present application only considers the charge loss capacity value in the charge-discharge cycle when calculating the total charge loss capacity value of the lithium battery, and eliminates the superposition effect of the discharge loss capacity value in the pre-stage on the charge loss capacity value. Similarly, when calculating the total discharge loss capacity value of the lithium battery, only the discharge loss capacity value in the charge-discharge cycle is considered. In addition, when calculating, the charge-discharge current used can be a very small current without polarization, such as 0.02C. Thus, the influence of the kinetic capacity loss can be eliminated, and only the thermodynamic capacity loss is considered, so as to ensure that the calculated total charge (or discharge) loss capacity value can reflect the true irreversible decay of the lithium battery, and then the accuracy of the determined CB value can be ensured to be high.

[0124] Step S2, determining the total charge loss capacity value of the lithium battery based on the sum of the charge loss capacity values of the lithium battery in the multiple charge-discharge cycles up to the present.

[0125] The BMS can directly determine the sum of the charge loss capacity values of the lithium battery in the multiple charge-discharge cycles as the total charge loss capacity value of the lithium battery. Alternatively, the BMS can determine the product of the sum of the charge loss capacity values of the lithium battery in the multiple charge-discharge cycles and a preset coefficient as the total charge loss capacity value of the lithium battery.

[0126] Step S3, determining the total discharge loss capacity value of the lithium battery based on the sum of the discharge loss capacity values of the lithium battery in the multiple charge-discharge cycles up to the present.

[0127] The BMS can determine the total discharge loss capacity value of the lithium battery as the sum of the discharge loss capacity values of the lithium battery in the multiple charge-discharge cycles. Alternatively, the BMS can determine the total discharge loss capacity value of the lithium battery as the product of the sum of the discharge loss capacity values of the lithium battery in the multiple charge-discharge cycles and a preset coefficient.

[0128] In step 203, the first total loss capacity value, the total lithium loss value, and the second total loss capacity value of the lithium battery are determined based on the first dV / dQ data and the second dV / dQ data.

[0129] The first total loss capacity value is the sum of the cathode loss capacity value and the anode loss capacity value of the lithium battery. The second total loss capacity value is the sum of the cathode loss capacity value and the target lithium loss value of the lithium battery. The target lithium loss value is caused by the decomposition of the electrolyte and the deposition of lithium ions in the electrolyte.

[0130] In the embodiments of the present application, the BMS can obtain the lateral distance reduction amount of the first peak and the second peak in the first dV / dQ curve relative to the second dV / dQ curve, the lateral position change amount of the second peak, and the intensity reduction amount of the third peak. Then, the BMS can determine the first total loss capacity value of the lithium battery based on the lateral distance reduction amount, determine the total lithium loss value of the lithium battery based on the position change amount, and determine the second total loss capacity value of the lithium battery based on the intensity reduction amount.

[0131] The first total loss capacity value is proportional to the lateral distance reduction amount. For example, the first total loss capacity value can be the lateral distance reduction amount, or can be the product of the lateral distance reduction amount and a preset coefficient. The total lithium loss value is proportional to the position change amount. For example, the total lithium loss value can be the position change amount, or can be the product of the total lithium loss value and a preset coefficient. The second total loss capacity value is proportional to the intensity reduction amount. For example, the second total loss capacity value can be the intensity reduction amount, or can be the product of the intensity reduction amount and a preset coefficient.

[0132] The first peak and the second peak are both associated with the first total loss capacity, and the second peak is also associated with the total lithium loss. The third peak is associated with the second total loss capacity. The first total loss capacity is the parameter to which the first total loss capacity value belongs. That is, the first total loss capacity value is the parameter value of the first total loss capacity. The total lithium loss is the parameter to which the total lithium loss value belongs. The second total loss capacity is the parameter to which the second total loss capacity value belongs. In addition, the association of each of the first peak, the second peak, and the third peak with the parameter can be determined by the BMS in advance.

[0133] In the embodiments of the present application, the process of obtaining, by the BMS, the lateral distance reduction amount of the first peak and the second peak, the lateral position change amount of the second peak, and the intensity reduction amount of the third peak can include:

[0134] The BMS obtains, from the first dV / dQ curve, a first lateral distance between the first peak and the second peak, a first lateral position of the second peak, and a first peak value of the third peak; and obtains a second lateral distance between the first peak and the second peak, a second lateral position of the second peak, and a second peak value of the third peak. Subsequently, the BMS can determine, based on a difference between the second lateral distance and the first lateral distance, a lateral distance reduction amount of the first peak and the second peak; based on a difference between the second lateral position and the first lateral position, a lateral position change amount of the second peak; and based on a difference between the second peak value and the first peak value, an intensity reduction amount of the third peak.

[0135] The second lateral distance, the second lateral position, and the second peak value are determined based on the second dV / dQ curve. For example, the second lateral distance, the second lateral position, and the second peak value can be pre-stored by the BMS. Alternatively, the BMS can obtain the second lateral distance, the second lateral position, and the second peak value from the second dV / dQ curve.

[0136] It can be understood that the first (or second) lateral distance refers to a projection value of a distance between the first peak and the second peak on the horizontal axis of the first (or second) dV / dQ curve. The first (or second) lateral position refers to a position of the second peak on the horizontal axis of the first (or second) dV / dQ curve. The difference between the second lateral distance and the first lateral distance refers to a difference obtained by subtracting the first lateral distance from the second lateral distance. The difference between the second lateral position and the first lateral position refers to a difference obtained by subtracting the first lateral position from the second lateral position. The difference between the second peak value and the first peak value refers to a difference obtained by subtracting the first peak value from the second peak value.

[0137] An example of the method for determining the cathode loss capacity value and the anode loss capacity value of the lithium battery is shown in FIG. 4. Figure 5 An example of the method for determining the cathode loss capacity value and the anode loss capacity value of the lithium battery is shown in FIG. 4. Figure 3 The non-polarization discharge curve shown in FIG. 3 is used to obtain a schematic diagram of the dV / dQ curve. From the non-polarization discharge curve, the BMS can obtain the first dV / dQ curve and the second dV / dQ curve. Figure 5 It can be seen that there is a large difference between the non-polarization discharge curves of the fresh lithium battery and the used lithium battery.

[0138] Figure 5 In the example shown in FIG. 4, the middle peak 1 is the first peak, the peak 2 is the second peak, and the peak 3 is the third peak. The first lateral distance between the peak 1 and the peak 2 is d1, the second lateral distance is d2, the lateral position change amount of the peak 2 is A2, and the intensity reduction amount of the peak 3 is A1. Therefore, the BMS determines the first total loss capacity value as d2-d1, the lithium loss total amount value as A2, and the second total loss capacity value as A1.

[0139] Step 204: determining the cathode loss capacity value and the anode loss capacity value of the lithium battery based on the charging total loss capacity value, the discharging total loss capacity value, the first total loss capacity value, the lithium loss total amount value, and the second total loss capacity value of the lithium battery.

[0140] In the embodiments of the present application, the BMS can input the total charge loss capacity value, the total discharge loss capacity value, the first total loss capacity value, the second total loss capacity value and the total lithium loss value into the loss capacity calculation model to obtain the first loss component value, the second loss component value, the third loss component value and the fourth loss component value output by the loss capacity calculation model. Then, the BMS can determine the cathode loss capacity value of the lithium battery based on the sum of the first loss component value and the second loss component value, and determine the anode loss capacity value of the lithium battery based on the sum of the third loss component value and the fourth loss component value.

[0141] The cathode loss capacity value is proportional to the sum of the first loss component value and the second loss component value. For example, the cathode loss capacity value can be the sum of the first loss component value and the second loss component value, or the product of the sum and a preset coefficient.

[0142] The anode loss capacity value of the lithium battery is proportional to the sum of the third loss component value and the fourth loss component value. For example, the anode loss capacity value can be the sum of the third loss component value and the fourth loss component value, or the product of the sum and a preset coefficient.

[0143] The first loss component value is the capacity loss value of the cathode caused by structural damage of the cathode, and the second loss component value is the capacity loss value of the cathode caused by cathode polarization. The third loss component value is the capacity loss value of the anode caused by structural damage of the anode, and the fourth loss component value is the capacity loss value of the anode caused by anode polarization.

[0144] In the embodiments of the present application, the loss capacity calculation model can include: a first functional relationship that the first total loss capacity changes with the first loss component, the second loss component, the third loss component and the fourth loss component; a second functional relationship that the total lithium loss changes with the target lithium loss, the second loss component and the fourth loss component; a third functional relationship that the second total loss capacity changes with the third loss component, the fourth loss component and the target lithium loss; a fourth functional relationship that the total charge loss capacity changes with the second loss component and the third loss component; and a fifth functional relationship that the total discharge loss capacity changes with the target lithium loss, the first loss component and the fourth loss component.

[0145] The first loss component is a parameter to which the first loss component value belongs, the second loss component is a parameter to which the second loss component value belongs, the third loss component is a parameter to which the third loss component value belongs, and the fourth loss component is a parameter to which the first loss component belongs. The target lithium loss is a parameter to which the target lithium loss value described above belongs.

[0146] The process in which the BMS inputs the total charge loss capacity value, the total discharge loss capacity value, the first total loss capacity value, the second total loss capacity value, and the total lithium loss value into the loss capacity calculation model to obtain the first loss component value, the second loss component value, the third loss component value, and the fourth loss component value output by the loss capacity calculation model can include: inputting the first total loss capacity value into a first function relationship, inputting the total lithium loss value into a second function relationship, inputting the second total loss capacity value into a third function relationship, inputting the total charge loss capacity value into a fourth function relationship, and inputting the total discharge loss capacity value into a fifth function relationship, so as to obtain the first loss component value to the fourth loss component value.

[0147] For example, the first function relationship to the fifth function relationship can satisfy:

[0148] Q1 = LAM-PE + LAM-NE = PE-de + PE-Li + NE-de + NE-Li

[0149] Q2 = LLI = LLI(Pure) + PE-Li + NE-Li

[0150] Q3 = LAM-NE + LLI(Pure) = NE-de + NE-Li + LLI(Pure)

[0151] = PE-Li + NE-de

[0152] = LLI(Pure) + PE-de + NE-Li

[0153] wherein Q1 represents the first total loss capacity, LAM-PE represents the cathode loss capacity, LAM-NE represents the anode loss capacity. PE-de represents the first loss component, PE-Li represents the second loss component, NE-de represents the third loss component, and NE-Li represents the fourth loss component. Q2 represents the total lithium loss, LLI(Pure) represents the target lithium loss. Q3 represents the second total loss capacity, represents the total charge loss capacity, represents the total discharge loss capacity.

[0154] The BMS can input the total charge loss capacity value, the total discharge loss capacity value, the first total loss capacity value, the second total loss capacity value, and the total lithium loss value into the above function relationships through the loss capacity calculation model to obtain a plurality of equations. Subsequently, the loss capacity calculation model can solve the plurality of equations simultaneously to output the first loss component value to the fourth loss component value.

[0155] Step 205, determining the CB value of the lithium battery in use based on the cathode loss capacity value and the anode loss capacity value of the lithium battery.

[0156] Referring to Figure 6 , the process of step 205 performed by the BMS can include:

[0157] Step 2051, determining the target residual capacity of the lithium battery based on the cathode loss capacity value and the anode loss capacity value of the lithium battery.

[0158] Wherein, the target residual capacity is the larger one of the maximum residual capacity value of the cathode and the maximum residual capacity value of the anode.

[0159] In the embodiments of the present application, the BMS can obtain the initial maximum capacity value of the cathode (which can also be referred to as the full capacity of the cathode) and the initial maximum capacity value of the anode (which can also be referred to as the full capacity of the anode). Then, the BMS can determine the maximum residual capacity value of the cathode based on the difference between the initial maximum capacity value of the cathode and the cathode loss capacity value, and determine the maximum residual capacity value of the anode based on the difference between the initial maximum capacity value of the anode and the anode loss capacity value. After that, the BMS can determine the larger one of the maximum residual capacity value of the cathode and the maximum residual capacity value of the anode as the target residual capacity of the lithium battery.

[0160] Wherein, the maximum residual capacity value of the cathode is proportional to the difference between the initial maximum capacity value of the cathode and the cathode loss capacity value. The maximum residual capacity value of the anode is proportional to the difference between the initial maximum capacity value of the anode and the anode loss capacity value. For example, the maximum residual capacity value of the cathode (or the anode) can be the difference between the initial maximum capacity value of the cathode (or the anode) and the cathode (or anode) loss capacity value, or the product of the difference and a preset coefficient. The difference between the initial maximum capacity value of the cathode (or the anode) and the cathode (or anode) loss capacity value refers to the difference obtained by subtracting the cathode (or anode) loss capacity value from the initial maximum capacity value of the cathode (or the anode).

[0161] The initial maximum capacity value of the cathode and the initial maximum capacity value of the anode can be pre-stored by the BMS. For example, the staff can assemble the electrode materials of the lithium battery which has not undergone charge-discharge cycles into a button half-cell, test the button half-cell to obtain the initial maximum capacity values of the cathode and the anode, and write them into the BMS.

[0162] Step 2052, determining the CB value of the lithium battery in use based on the target residual capacity and the current full capacity of the lithium battery.

[0163] wherein, in the case that the target remaining capacity is the maximum remaining capacity value of the cathode, the CB value is proportional to the ratio of the current full capacity to the target remaining capacity. In the case that the target remaining capacity is the maximum remaining capacity value of the anode, the CB value is proportional to the ratio of the target remaining capacity to the current full capacity. The current full capacity refers to the maximum amount of electricity that the lithium battery can store when it is fully charged.

[0164] For example, in the case that the target remaining capacity is the maximum remaining capacity value of the cathode, the CB value can satisfy: In the case that the target remaining capacity is the maximum remaining capacity value of the anode, the CB value can satisfy: .

[0165] In one possible embodiment, the BMS can determine the current full capacity of the lithium battery as the smaller one of the maximum remaining capacity value of the cathode and the maximum remaining capacity value of the anode.

[0166] In another possible embodiment, the BMS can obtain the current non-polarization discharge curve of the lithium battery, and obtain the current full capacity of the lithium battery based on the non-polarization discharge curve. The full capacity is the capacity value corresponding to the end point of the non-polarization discharge curve. That is, the capacity of the lithium battery when it is fully charged or discharged using a very small non-polarization current (regarded as a non-polarization current) is the current full capacity of the lithium battery.

[0167] The following describes the change of the non-polarization discharge curve after the cathode capacity and the anode capacity of the lithium battery are lost:

[0168] Figure 7 is a schematic diagram of the anode capacity change curve, the cathode capacity change curve, and the non-polarization discharge curve of a fresh lithium battery. Wherein, 0% of the cathode (i.e. the positive electrode) capacity indicates that 100% of the active sites in the cathode material are occupied by lithium ions (i.e. Li + ), and Li + is not completely deintercalated. 100% of the cathode capacity indicates that 0% of the active sites in the cathode material are occupied by Li + , and Li + is completely deintercalated. 0% of the anode (i.e. the negative electrode) capacity indicates that 0% of the active sites in the anode material are occupied by Li + , and Li + is completely deintercalated. 100% of the anode capacity indicates that 100% of the active sites in the anode material are occupied by Li + . Wherein, the active site is a specific position in the electrode material that can reversibly interact (such as intercalation, deintercalation, adsorption, or chemical reaction) with Li + , and is a carrier for Li + storage and migration.

[0169] FromFigure 7 It can be seen that during the discharge process, the discharge capacity of the lithium battery gradually increases, while the voltage gradually decreases. During the discharge process, Li... + It will de-intercalate from the anode and intercalate back into the cathode. Therefore, as... Figure 7 As shown, with the gradual increase of the discharge capacity value, the Li deintercalation from the anode... + The more [X3] there is, the smaller the anode capacity will be, starting from X3 and gradually decreasing until it reaches X2. X2 is less than X3 and greater than 0%. Meanwhile, as the discharge capacity value gradually increases, the Li embedded in the cathode […]. + The more lithium is added, the lower the cathode capacity will gradually decrease from X1, eventually reaching 0%, meaning that 100% of the active sites on the cathode will be covered by Li. + occupy.

[0170] like Figure 7 As shown, when a lithium battery is fully charged, its cathode capacity is X1, where X1 is less than 100%. This means that the cathode capacity of a lithium battery will not reach 100% when fully charged, but rather has a certain design margin (i.e., ...). Figure 7 (The positive electrode design margin is shown). This is mainly because when the cathode capacity is 100%, the Li... + It will completely escape from the cathode, causing significant damage to the structural stability of the cathode material. Furthermore, the anode capacity is designed with a certain margin during the charging and discharging of lithium batteries. For example... Figure 7 As shown, the usable range of the anode capacity is from X2 to X3, where X3 is less than 100%, i.e. Figure 7 The diagram shows negative electrode design margin 1 and negative electrode design margin 2. This arrangement is mainly based on the following considerations: Firstly, during the first discharge of a fresh lithium battery, a portion of the active sites in the anode (such as...) Figure 7 The negative electrode design margin 2) shown will participate in the formation of the solid electrolyte interface (SEI) film; on the other hand, the anode needs more active sites (such as...) compared to the cathode. Figure 7 The negative electrode design margin shown is 1), so that the Li extracted from the cathode + It can be completely contained by the anode, which can avoid lithium plating on the negative electrode or the negative electrode potential being less than or equal to 0V.

[0171] However, with the use of lithium batteries, they experience various forms of capacity loss. For example... Figure 8 As shown, various capacity losses include: the collapse of partial structures (such as the dissolution of transition metal atoms or the formation of inert phases) due to the calendar aging of the cathode material, leading to Li... + The first loss component caused by the inability to re-enter is denoted as PE-de (Positive electrode-degradation); this is due to the formation of a Li-rich cathode. +The cathode electrolyte interface (CEI) film or inert phase leads to Li + The component that cannot be extracted from the cathode, i.e., the second loss component caused by cathode polarization, is denoted as PE-Li (Positive Electrode-Li); due to the calendar aging of the anode material, part of the structure collapses (such as Li). + Deintercalation causes anode expansion, resulting in extreme fatigue strain, and in severe cases, the negative electrode particles break down, leading to Li... + The third loss component caused by the inability to embed is denoted as NE-de (Negative electrode-degradation); this is due to the formation of Li-rich anode material. + SEI or inert phase leads to Li + The component that cannot be removed from the anode, i.e., the fourth loss component caused by anodic polarization, is denoted as NE-Li (Negative electrode-Li); this loss is due to the decomposition of the electrolyte and the presence of Li in the electrolyte. + The loss of target lithium due to deposition. Among them, Li + Deposition can be caused by high-rate charging conditions, which refer to charging at a current rate greater than the rate threshold. The inert phase refers to inert phases other than the SEI and CEI modes. The second and fourth loss components will cause Li in the lithium battery to... + The total amount decreased.

[0172] As lithium batteries age, various capacity losses occur, causing changes in the anode capacity variation curve, cathode capacity variation curve, and the non-polarized discharge curve of the entire cell. For example... Figure 9 As shown, the first loss component PE-de will cause Li to be intercalated back into the cathode. + The quantity decreases, so when the lithium battery is fully discharged, the cathode capacity will change from 0% to X4, where X4 is greater than 0%. The second loss component, PE-Li, causes Li to be extracted from the cathode. + The reduced quantity means that when the lithium battery is fully charged, the cathode capacity decreases from X1 to X5, where X5 is less than X1. The fourth loss component, NE-Li, causes Li to be extracted from the anode. + The number of cells decreases, so when the cell is fully discharged, the anode capacity changes from X2 to X6, where X6 is greater than X2. The third loss component, PE-de, causes the Li-containing cells embedded in the anode to... + With fewer cells, the anode capacity becomes X7 when the battery is fully discharged, and X7 is less than X3. In lithium-ion batteries experiencing lithium loss, the positive electrode curve shifts to the upper left, and the negative electrode curve shifts to the lower left.

[0173] Therefore, it can be seen that in the use of lithium battery calendars, such as Figure 10As shown, the position of the segment of the electrode that does not release lithium and the position of the segment of the electrode that releases lithium can change due to factors such as loss of electrode material and polarization. Thus, the CB value of the lithium battery in calendar use can dynamically change.

[0174] According to the above description, the method provided in the embodiments of the present application can analyze various loss capacities of the lithium battery in use from the two dimensions of kinetics and thermodynamics, analyze the influence of various loss capacities on electrode capacity, and thus propose calculation logic of cathode loss capacity and anode loss capacity, and then calculate the current real CB value of the lithium battery. Since the dimensions considered are relatively comprehensive, the calculation logic can be relatively close to the actual working condition of the lithium battery, and thus the reliability of the determined CB value can be relatively high.

[0175] In the embodiments of the present application, the cathode tab area, the anode tab area and the tab SOC of the fresh stacked battery can be changed to simulate different failure modes (i.e. mechanisms causing capacity attenuation); and the characteristic peaks of the dV / dQ curve of the lithium battery under different failure modes are calibrated, so as to determine the peaks in the dV / dQ curve associated with the first total loss capacity, the lithium loss amount and the second total loss capacity. Then, when the CB value needs to be determined, the parameter values of the parameters of the first total loss capacity, the lithium loss amount and the second total loss capacity can be quantified by comparing the position or peak value of the characteristic peaks of the dV / dQ curve.

[0176] It can be understood that, taking the stacked battery as an example, the stacked battery can be designed by referring to the following manner to realize the calibration of the characteristic peaks in the dV / dQ curve of the lithium battery associated with the first total loss capacity, the lithium loss amount and the second total loss capacity:

[0177] Figure 11 A stacked battery design for evaluating LLI is shown. As shown in FIG. 6A, cathode tabs with multiple gradient state of charge (SOC) can be used, and the anode uses 0% SOC tabs. As the lithium content in the cathode decreases, the overall system LLI increases, and the capacity loss or lithium consumption loss mode at full charge is mainly LLI. Figure 11

[0178] Figure 12 A stacked battery design for evaluating PE-Li is shown. As shown in FIG. 7A, 0% SOC cathode tabs and 0% SOC anode tabs are used. The cathode area decreases, i.e. the cathode capacity decreases, and the anode capacity remains unchanged. As the lithium content in the cathode decreases, the overall system LLI increases, and the capacity loss or lithium consumption loss mode at full charge is mainly LLI and PE-Li. Figure 12

[0179] Figure 13 ​​A stack design for evaluating PE-de is shown. As shown in Figure 13 100% SOC cathode electrode sheet and 100% SOC anode electrode sheet are used. The cathode area is reduced, the lithium content is unchanged, and the anode area is unchanged. Due to the loss of the anode material, the residual lithium in the cathode is too much, the LLI is increased, and the capacity loss or lithium consumption loss mode at full discharge is mainly LLI and PE-de. +

[0180] Figure 14 A stack design for evaluating NE-Li is shown. As shown in Figure 14 100% SOC cathode electrode sheet and 100% SOC anode electrode sheet are used. The anode area is reduced, the anode capacity is reduced, and the cathode capacity is unchanged. With the reduction of the lithium content in the anode, the LLI of the whole system is increased, and the capacity loss or lithium consumption loss mode at full discharge is mainly LLI and NE-Li.

[0181] Figure 15 A stack design for evaluating NE-de is shown. As shown in Figure 15 0% SOC cathode electrode sheet and 0% SOC anode electrode sheet are used. The anode area is reduced, the anode capacity is reduced, the cathode capacity is unchanged, the lithium content is unchanged, and the cathode area is unchanged. Due to the loss of the anode material, the residual lithium in the cathode is too much, the LLI is increased, and the capacity loss or lithium consumption loss mode at full discharge is mainly LLI and NE-de.

[0182] It can be understood that the order of the steps of the method for determining the CB value of the lithium battery provided by the embodiments of the present application can be adjusted appropriately, and the steps can also be increased or decreased accordingly according to the circumstances. Any person skilled in the art can easily think of a method of change within the technical range disclosed by the present application, which should be covered within the protection scope of the present application, and therefore will not be described again.

[0183] In summary, the embodiments of the present application provide a method for determining the CB value of a lithium battery. The method can obtain the charge and discharge data of the lithium battery, the first dV / dQ data at present, and the second dV / dQ data when the lithium battery is shipped. Subsequently, the method can accurately determine the cathode loss capacity value and the anode loss capacity value of the lithium battery based on the charge and discharge data, the first dV / dQ data, and the second dV / dQ data, and then determine the CB value of the lithium battery in the use process based on the cathode loss capacity value and the anode loss capacity value.

[0184] The embodiments of the present application provide a controller which can be used to execute the method for determining the CB value of the lithium battery provided by the above-mentioned method embodiments. Referring to Figure 16 , the controller 300 includes a processor 301. The processor 301 is configured to: ​

[0185] obtain the charge-discharge data of the lithium battery, the first dV / dQ data, and the second dV / dQ data of the lithium battery when the lithium battery is shipped;

[0186] determine the cathode loss capacity value and the anode loss capacity value of the lithium battery based on the charge-discharge data, the first dV / dQ data, and the second dV / dQ data;

[0187] determine the CB value of the lithium battery in use based on the cathode loss capacity value and the anode loss capacity value.

[0188] Optionally, the lithium battery comprises an electrolyte. The process in which the processor 301 determines the cathode loss capacity value and the anode loss capacity value of the lithium battery based on the charge-discharge data, the first dV / dQ data, and the second dV / dQ data can comprise:

[0189] determine the total charge loss capacity value and the total discharge loss capacity value of the lithium battery based on the charge-discharge data;

[0190] determine the first total loss capacity value, the lithium loss total value, and the second total loss capacity value of the lithium battery based on the first dV / dQ data and the second dV / dQ data, wherein the first total loss capacity value is the sum of the cathode loss capacity value and the anode loss capacity value, and the second total loss capacity value is the sum of the cathode loss capacity value and the target lithium loss value, and the target lithium loss value is caused by electrolyte decomposition and lithium ion deposition in the electrolyte;

[0191] determine the cathode loss capacity value and the anode loss capacity value of the lithium battery based on the total charge loss capacity value, the total discharge loss capacity value, the first total loss capacity value, the second total loss capacity value, and the lithium loss total value.

[0192] Optionally, the first dV / dQ data is represented by a first dV / dQ curve, and the second dV / dQ data is represented by a second dV / dQ curve. The process in which the processor 301 determines the first total loss capacity value, the lithium loss total value, and the second total loss capacity value of the lithium battery based on the first dV / dQ data and the second dV / dQ data can comprise:

[0193] obtain the lateral distance reduction amount of the first peak and the second peak in the first dV / dQ curve, the lateral position change amount of the second peak, and the intensity reduction amount of the third peak compared to the second dV / dQ curve;

[0194] determine the first total loss capacity value of the lithium battery based on the lateral distance reduction amount, and the first total loss capacity value is directly proportional to the lateral distance reduction amount;

[0195] determine the lithium loss total value of the lithium battery based on the lateral position change amount, and the lithium loss total value is directly proportional to the lateral position change amount;

[0196] determine a second total loss capacity value of the lithium battery based on the intensity reduction amount, the second total loss capacity value being proportional to the intensity reduction amount;

[0197] wherein the first peak and the second peak are both associated with a first total loss capacity of the lithium battery, the second peak is further associated with a total lithium loss of the lithium battery, and the third peak is associated with a second total loss capacity of the lithium battery.

[0198] Optionally, the process that the processor 301 obtains the lateral distance reduction amount of the first peak and the second peak, the lateral position change amount of the second peak, and the intensity reduction amount of the third peak in the first dV / dQ curve compared to the second dV / dQ curve can include:

[0199] obtain a first lateral distance of the first peak and the second peak, a first lateral position of the second peak, and a first peak value of the third peak from the first dV / dQ curve;

[0200] obtain a second lateral distance of the first peak and the second peak, a second lateral position of the second peak, and a second peak value of the third peak, the second lateral distance, the second lateral position, and the second peak value being determined based on the second dV / dQ curve;

[0201] determine the lateral distance reduction amount of the first peak and the second peak based on a difference between the second lateral distance and the first lateral distance;

[0202] determine the lateral position change amount of the second peak based on a difference between the second lateral position and the first lateral position;

[0203] determine the intensity reduction amount of the third peak based on a difference between the second peak value and the first peak value.

[0204] Optionally, the process that the processor 301 determines the charge total loss capacity value and the discharge total loss capacity value of the lithium battery based on the charge-discharge data can include:

[0205] obtain, based on the charge-discharge data, charge loss capacity values and discharge loss capacity values of the lithium battery in each charge-discharge cycle up to the present;

[0206] determine the charge total loss capacity value of the lithium battery based on a sum of the charge loss capacity values of the lithium battery in the multiple charge-discharge cycles up to the present;

[0207] determine the discharge total loss capacity value of the lithium battery based on a sum of the discharge loss capacity values of the lithium battery in the multiple charge-discharge cycles up to the present.

[0208] Optionally, the process that the processor 301 obtains the charge loss capacity values and the discharge loss capacity values of the lithium battery in each charge-discharge cycle up to the present based on the charge-discharge data can include:

[0209] Based on the charging and discharging data, the charging capacity value and the discharging capacity value of the lithium battery in each charging and discharging cycle up to the present are obtained;

[0210] For each charging and discharging cycle, based on the difference between the discharging capacity value in the previous charging and discharging cycle and the charging capacity value in the current charging and discharging cycle, the charging loss capacity value in the current charging and discharging cycle is determined;

[0211] And, based on the difference between the charging capacity value and the discharging capacity value in the current charging and discharging cycle, the discharging loss capacity value in the current charging and discharging cycle is determined.

[0212] Optionally, the process of determining the cathode loss capacity value and the anode loss capacity value of the lithium battery based on the total charging loss capacity value, the total discharging loss capacity value, the first total loss capacity value, the second total loss capacity value and the total lithium loss value can include:

[0213] inputting the total charging loss capacity value, the total discharging loss capacity value, the first total loss capacity value, the second total loss capacity value and the total lithium loss value into a loss capacity calculation model to obtain a first loss component value, a second loss component value, a third loss component value and a fourth loss component value output by the loss capacity calculation model;

[0214] determining the cathode loss capacity value of the lithium battery based on the sum of the first loss component value and the second loss component value;

[0215] determining the anode loss capacity value of the lithium battery based on the sum of the third loss component value and the fourth loss component value;

[0216] The first loss component value is the capacity loss value caused by the structural damage of the cathode, and the second loss component value is the capacity loss value caused by the cathode polarization; the third loss component value is the capacity loss value caused by the structural damage of the anode, and the fourth loss component value is the capacity loss value caused by the anode polarization.

[0217] Optionally, the loss capacity calculation model includes:

[0218] a first functional relationship between the first total loss capacity and the first loss component, the second loss component, the third loss component and the fourth loss component;

[0219] a second functional relationship between the total lithium loss and the target lithium loss, the second loss component and the fourth loss component;

[0220] a third functional relationship between the second total loss capacity and the first loss component, the second loss component and the target lithium loss;

[0221] a fourth functional relationship between the total charging loss capacity and the second loss component and the third loss component;

[0222] a fifth function relationship of the total discharge loss capacity varying with the target lithium loss, the first loss component and the fourth loss component.

[0223] The process in which the processor 301 inputs the total charge loss capacity value, the total discharge loss capacity value, the first total loss capacity value, the second total loss capacity value and the total lithium loss value into the loss capacity calculation model to obtain the first loss component value, the second loss component value, the third loss component value and the fourth loss component value output by the loss capacity calculation model can include:

[0224] The first total loss capacity value is brought into the first function relationship, the total lithium loss value is brought into the third function relationship, the second total loss capacity value is brought into the third function relationship, the total charge loss capacity value is brought into the fourth function relationship, and the total discharge loss capacity value is brought into the fifth function relationship to obtain the first loss component value to the fourth loss component value.

[0225] Optionally, the lithium battery includes a cathode and an anode. The process in which the processor 301 determines the CB value of the lithium battery in use based on the cathode loss capacity value and the anode loss capacity value can include:

[0226] Based on the cathode loss capacity value and the anode loss capacity value, a target remaining capacity of the lithium battery is determined, the target remaining capacity being the larger one of a maximum remaining capacity value of the cathode and a maximum remaining capacity value of the anode.

[0227] Based on the target remaining capacity and a current full capacity of the lithium battery, the CB value of the lithium battery in use is determined.

[0228] Optionally, in a case where the target remaining capacity is the maximum remaining capacity value of the cathode, the CB value is proportional to a ratio of the full capacity to the target remaining capacity.

[0229] In a case where the target remaining capacity is the maximum remaining capacity value of the anode, the CB value is proportional to a ratio of the target remaining capacity to the full capacity.

[0230] Optionally, the process in which the processor 301 determines the target remaining capacity of the lithium battery based on the cathode loss capacity value and the anode loss capacity value can include:

[0231] An initial maximum capacity value of the cathode and an initial maximum capacity value of the anode are obtained.

[0232] Based on a difference between the initial maximum capacity value of the cathode and the cathode loss capacity value, a maximum remaining capacity value of the cathode is determined, and based on a difference between the initial maximum capacity value of the anode and the anode loss capacity value, a maximum remaining capacity value of the anode is determined.

[0233] The larger of the maximum remaining capacity of the cathode and the maximum remaining capacity of the anode is determined as the target remaining capacity of the lithium battery.

[0234] Optionally, processor 301 can also be used for:

[0235] Before determining the CB value of the lithium battery during use based on the target remaining capacity and the current full charge capacity of the lithium battery, the smaller of the maximum remaining capacity value of the cathode and the maximum remaining capacity value of the anode is determined as the current full charge capacity of the lithium battery.

[0236] Therefore, the full capacitance can be obtained quickly, thereby improving the efficiency of determining the CB value.

[0237] Optionally, processor 301 can also be used for:

[0238] Before determining the CB value of the lithium battery during use based on the target remaining capacity and the current full charge capacity of the lithium battery, obtain the current non-polarized discharge curve of the lithium battery.

[0239] The current full-charge capacity of the lithium battery is obtained based on the non-polarized discharge curve.

[0240] This improves the accuracy of obtaining full capacitance and the accuracy of determining the CB value.

[0241] In summary, this application provides a controller capable of acquiring charge / discharge data of a lithium battery, the current first dV / dQ data, and the second dV / dQ data at the time of manufacture. Subsequently, based on this charge / discharge data, the first dV / dQ data, and the second dV / dQ data, the controller can accurately determine the cathode loss capacity value and the anode loss capacity value of the lithium battery. Furthermore, based on these cathode loss capacity values ​​and anode loss capacity values, the CB value of the lithium battery during use can be determined.

[0242] like Figure 16 As shown, the controller 300 further includes a memory 303. The processor 301 and the memory 303 are connected, for example, via a bus 302. Optionally, the controller 300 may also include a transceiver 304. It should be noted that in practical applications, the transceiver 304 is not limited to one, and the structure of the controller 300 does not constitute a limitation on the embodiments of this application.

[0243] The processor 301 can be a CPU (Central Processing Unit), a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array) or other programmable logic device, transistor logic device, hardware component, or any combination thereof. It can implement or execute various exemplary logical blocks, modules and circuits described in combination with the disclosure. The processor 301 can also be a combination of computing functions, such as one or more microprocessor combinations, combinations of DSP and microprocessor, etc.

[0244] The bus 302 can include a path for transmitting information between the above-mentioned components. The bus 302 can be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. The bus 302 can be divided into an address bus, a data bus, a control bus, etc. For convenience of representation, Figure 16 Only one thick line is used in the figure, but it does not mean that there is only one bus or only one type of bus.

[0245] The memory 303 is used to store a computer program corresponding to the CB value determination method of the lithium battery provided by the above-mentioned embodiments of the application, which is controlled and executed by the processor 301. The processor 301 is used to execute the computer program stored in the memory 303 to realize the content shown in the foregoing method embodiments.

[0246] The embodiments of the present application provide a computer readable storage medium, which stores a computer program. When the computer program is executed by a processor, the method provided by the above-mentioned method embodiments is realized. As shown in the method. Figure 1 Or Figure 2 The method.

[0247] The embodiments of the present application provide a computer program product, which includes a computer program or computer instructions. When the computer program or computer instructions are executed by a processor, the method provided by the above-mentioned method embodiments is realized. As shown in the method. Figure 1 Or Figure 2 The method.

[0248] The embodiments of the present application provide a BMS, which includes a controller provided by the above-mentioned device embodiments. As shown in the method.Figure 16 the controller.

[0249] The embodiments of the present application also provide an electrical appliance, comprising the BMS provided by the device embodiments described above. Optionally, the electrical appliance can comprise a vehicle, a terminal device, an energy storage device, a machine device, etc. The terminal device can be a mobile phone, a tablet computer, a notebook computer, a desktop computer, etc. The machine device can be a robot or a robotic dog, etc.

[0250] It should be understood that the logic and / or steps represented in the flowcharts and / or otherwise described herein, for example, can be considered as a list of executable instructions for implementing logic functions, and can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor- based system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions, or a combination of the above. For purposes of this specification, a "computer-readable medium" can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection (electronic) having one or more wires, a portable computer diskette (magnetic), a random-access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, and a portable compact disc read-only memory (CDROM). In addition, the computer-readable medium can even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, for example, via the optical scanner of a device or other suitable device and then compiled, interpreted, or processed in a suitable manner, if necessary, and stored in a computer memory.

[0251] It should be understood that parts of the present application can be realized by hardware, software, firmware, or a combination thereof. In the above-described embodiments, a plurality of steps or methods can be realized by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if realized by hardware, and as in another embodiment, any one or a combination of the following technologies known in the art can be used: discrete logic circuitry having logic gates for implementing logic functions on data signals, application-specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), etc.

[0252] Although the embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary, and are not to be interpreted as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A method for determining the CB value of a lithium battery, characterized in that, The method includes: Acquire the charge / discharge data of the lithium battery, the current first dV / dQ data, and the second dV / dQ data of the lithium battery at the time of manufacture; Based on the charge / discharge data, the first dV / dQ data, and the second dV / dQ data, the cathode loss capacity value and the anode loss capacity value of the lithium battery are determined. Based on the cathode capacity loss value and the anode capacity loss value, the target remaining capacity of the lithium battery is determined, wherein the target remaining capacity is the larger of the maximum remaining capacity value of the cathode and the maximum remaining capacity value of the anode. Based on the target remaining capacity and the current full charge capacity of the lithium battery, the battery balance (CB) value during use is determined. If the target remaining capacity is the maximum remaining capacity of the cathode, the CB value is proportional to the ratio of the current full charge capacity to the target remaining capacity. If the target remaining capacity is the maximum remaining capacity of the anode, the CB value is proportional to the ratio of the target remaining capacity to the current full charge capacity. The current full charge capacity refers to the maximum amount of electricity that the lithium battery can store when it is fully charged.

2. The method according to claim 1, characterized in that, The lithium battery includes: an electrolyte; based on the charge / discharge data, the first dV / dQ data, and the second dV / dQ data, determining the cathode loss capacity value and the anode loss capacity value of the lithium battery includes: Based on the charge and discharge data, the total charging capacity loss value and the total discharging capacity loss value of the lithium battery are determined. Based on the first dV / dQ data and the second dV / dQ data, a first total capacity loss value, a total lithium loss value, and a second total capacity loss value of the lithium battery are determined. The first total capacity loss value is the sum of the cathode capacity loss value and the anode capacity loss value. The second total capacity loss value is the sum of the cathode capacity loss value and the target lithium loss value. The target lithium loss value is caused by electrolyte decomposition and lithium ion deposition in the electrolyte. Based on the total charging capacity loss value, the total discharging capacity loss value, the first total capacity loss value, the second total capacity loss value, and the total lithium loss value, the cathode capacity loss value and the anode capacity loss value of the lithium battery are determined.

3. The method according to claim 2, characterized in that, The first dV / dQ data is represented by a first dV / dQ curve, and the second dV / dQ data is represented by a second dV / dQ curve; based on the first dV / dQ data and the second dV / dQ data, the first total capacity loss value, the total lithium loss value, and the second total capacity loss value of the lithium battery are determined, including: Compared to the second dV / dQ curve, obtain the reduction in lateral distance between the first peak and the second peak in the first dV / dQ curve, the change in lateral position of the second peak, and the reduction in intensity of the third peak; Based on the reduction in lateral distance, a first total capacity loss value for the lithium battery is determined, wherein the first total capacity loss value is proportional to the reduction in lateral distance. Based on the lateral position change, the total lithium loss of the lithium battery is determined, and the total lithium loss is proportional to the lateral position change. Based on the reduction in strength, a second total capacity loss value for the lithium battery is determined, wherein the second total capacity loss value is proportional to the reduction in strength. The first peak and the second peak are both associated with the first total capacity loss of the lithium battery, the second peak is also associated with the total lithium loss of the lithium battery, and the third peak is associated with the second total capacity loss of the lithium battery.

4. The method according to claim 3, characterized in that, Compared to the second dV / dQ curve, the reduction in lateral distance between the first and second peaks in the first dV / dQ curve, the change in lateral position of the second peak, and the reduction in intensity of the third peak are obtained, including: From the first dV / dQ curve, obtain the first lateral distance between the first peak and the second peak, the first lateral position of the second peak, and the first peak value of the third peak; The second lateral distance between the first peak and the second peak, the second lateral position of the second peak, and the second peak value of the third peak are obtained. The second lateral distance, the second lateral position, and the second peak value are determined based on the second dV / dQ curve. Based on the difference between the second lateral distance and the first lateral distance, the reduction in the lateral distance between the first peak and the second peak is determined; The change in the lateral position of the second peak is determined based on the difference between the second lateral position and the first lateral position. The intensity reduction of the third peak is determined based on the difference between the second peak and the first peak.

5. The method according to claim 2, characterized in that, Based on the charge and discharge data, the total charging capacity loss and total discharging capacity loss of the lithium battery are determined, including: Based on the charge and discharge data, the charging loss capacity value and discharging loss capacity value of the lithium battery in each charge and discharge cycle up to the current time are obtained. The total charging loss capacity value of the lithium battery is determined based on the sum of the charging loss capacity values ​​of the lithium battery in the multiple charge-discharge cycles up to the present. The total discharge capacity loss of the lithium battery is determined based on the sum of the discharge capacity loss values ​​of the lithium battery in the multiple charge-discharge cycles up to the present.

6. The method according to claim 5, characterized in that, Based on the charge and discharge data, the charging loss capacity value and discharging loss capacity value of the lithium battery up to the current charge and discharge cycle are obtained, including: Based on the charge and discharge data, the charging capacity and discharging capacity of the lithium battery up to the current charge and discharge cycle are obtained. For each charge-discharge cycle, the charging loss capacity value in the current charge-discharge cycle is determined based on the difference between the discharge capacity value in the previous charge-discharge cycle and the charging capacity value in the current charge-discharge cycle. Furthermore, based on the difference between the charging capacity value and the discharging capacity value in this charge-discharge cycle, the discharge loss capacity value in this charge-discharge cycle is determined.

7. The method according to any one of claims 2 to 6, characterized in that, Based on the total charging capacity loss value, the total discharging capacity loss value, the first total capacity loss value, the second total capacity loss value, and the total lithium loss value, the cathode capacity loss value and the anode capacity loss value of the lithium battery are determined, including: The total charging loss capacity value, the total discharging loss capacity value, the first total loss capacity value, the second total loss capacity value, and the total lithium loss value are input into the loss capacity calculation model to obtain the first loss component value, the second loss component value, the third loss component value, and the fourth loss component value output by the loss capacity calculation model. The cathode loss capacity value of the lithium battery is determined based on the sum of the first loss component value and the second loss component value. The anode loss capacity value of the lithium battery is determined based on the sum of the third loss component value and the fourth loss component value. Wherein, the first loss component value is the capacity loss value caused by structural damage to the cathode, the second loss component value is the capacity loss value caused by cathode polarization, the third loss component value is the capacity loss value caused by structural damage to the anode, and the fourth loss component value is the capacity loss value caused by anode polarization.

8. The method according to claim 7, characterized in that, The loss capacity calculation model includes: The first functional relationship between the first total loss capacity and the first loss component, the second loss component, the third loss component, and the fourth loss component; A second functional relationship between the total lithium loss and the target lithium loss, the second loss component, and the fourth loss component; The third functional relationship between the second total loss capacity and the first loss component, the second loss component and the target lithium loss; A fourth functional relationship between the total charging capacity loss and the second and third loss components; A fifth functional relationship between the total discharge loss capacity and the target lithium loss, the first loss component, and the fourth loss component; The step of inputting the total charging loss capacity value, the total discharging loss capacity value, the first total loss capacity value, the second total loss capacity value, and the total lithium loss value into the loss capacity calculation model to obtain the first loss component value, the second loss component value, the third loss component value, and the fourth loss component value output by the loss capacity calculation model includes: The first total capacity loss value is substituted into the first functional relationship, the total lithium loss value is substituted into the third functional relationship, the second total capacity loss value is substituted into the third functional relationship, the total charging capacity loss value is substituted into the fourth functional relationship, and the total discharging capacity loss value is substituted into the fifth functional relationship to solve for the first loss component value to the fourth loss component value.

9. The method according to any one of claims 1 to 6, characterized in that, Determining the target remaining capacity of the lithium battery based on the cathode loss capacity value and the anode loss capacity value includes: Obtain the initial maximum capacity value of the cathode and the initial maximum capacity value of the anode; The maximum remaining capacity of the cathode is determined based on the difference between the initial maximum capacity value of the cathode and the cathode loss capacity value, and the maximum remaining capacity value of the anode is determined based on the difference between the initial maximum capacity value of the anode and the anode loss capacity value. The larger of the maximum remaining capacity of the cathode and the maximum remaining capacity of the anode is determined as the target remaining capacity of the lithium battery.

10. The method according to any one of claims 1 to 6, characterized in that, Before determining the battery balance CB value of the lithium battery during use based on the target remaining capacity and the current full charge capacity of the lithium battery, the method further includes: The smaller of the maximum remaining capacity of the cathode and the maximum remaining capacity of the anode is determined as the current full-charge capacity of the lithium battery.

11. The method according to any one of claims 1 to 6, characterized in that, Before determining the battery balance CB value of the lithium battery during use based on the target remaining capacity and the current full charge capacity of the lithium battery, the method further includes: Obtain the current nonpolar discharge curve of the lithium battery; Based on the non-polarized discharge curve, the current full-charge capacity of the lithium battery is obtained.

12. A controller, characterized in that, The controller includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, it implements the method as described in any one of claims 1-11.

13. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1-11.

14. A BMS, characterized in that, The BMS includes: the controller as described in claim 12.

15. An electrical appliance, characterized in that, include: The BMS as described in claim 14.

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