Battery charging voltage curve estimation method and device and battery state estimation method

Abstract

The invention relates to the technical field of battery management, in particular to a battery charging voltage curve estimation method and device and a battery state estimation method, and the method comprises the steps: obtaining a battery complete charging voltage curve at the initial stage of a life cycle through collecting battery complete charging data at the initial stage of the life cycle of a battery; constructing a battery charging process model according to the complete charging voltage curve of the battery at the initial stage of the life cycle, collecting actual charging data of the battery to obtain an actual charging voltage curve of the battery, and calculating the actual charging voltage curve of the battery according to the current actual charging voltage curve; utilizing the constructed battery charging process model to predict a battery complete charging voltage estimation curve capable of accurately reflecting the current battery complete charging state; the accuracy of battery state estimation can be improved when battery state estimation can be carried out based on the obtained battery complete charging voltage estimation curve.

Description

Technical Field

[0001] The present application relates to the technical field of battery management, and particularly relates to a method for estimating a battery charging voltage curve, a device, and a method for estimating a battery state. Background Art

[0002] Power batteries usually rarely experience full charge and full discharge scenarios. During actual use, power batteries usually cycle within the range of 30%-80% SOC (State of Charge). However, the overall charge and discharge voltage curve of the battery plays a crucial role in battery state analysis.

[0003] However, there is currently a lack of a method for estimating the complete voltage curve. Currently, the industry focuses on directly estimating the battery state through incomplete voltage curve information. For example, the dQ / dV capacity increment curve is usually used as a method for estimating battery capacity. This method requires the complete charging section as data input. Due to the limitations of incomplete charge and discharge of actual vehicle batteries, currently the industry mainly estimates the overall peak area based on the peak area of partial dQ / dV. Thus, capacity is estimated through the capacity increment curve. Estimating the overall battery state based on an incomplete charging curve is incomplete and inaccurate, and it is easy to make a wrong estimate of the battery state. Summary of the Invention

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present application is to provide a method for estimating a battery charging voltage curve, a device, and a method for estimating a battery state, which can accurately predict the complete charging voltage curve of the battery according to the actual battery charging voltage curve of the battery, and can accurately estimate the battery state by using the predicted complete charging voltage curve of the battery.

[0005] To achieve the above purpose and other related purposes, the present application provides a method for estimating a battery charging voltage curve, including:

[0006] Collect the complete charging data of the battery at the initial stage of the battery life cycle to obtain the complete charging voltage curve of the battery at the initial stage of the life cycle;

[0007] Obtain a battery charging process model according to the complete charging voltage curve of the battery at the initial stage of the life cycle;

[0008] Collect the actual charging data of the battery to obtain the actual charging voltage curve of the battery;

[0009] Obtain a predicted complete charging voltage curve of the battery by using the battery charging process model according to the actual charging voltage curve of the battery.

[0010] In an optional embodiment of the present application, obtaining a battery charging process model according to the complete charging voltage curve of the battery at the initial stage of the life cycle includes:

[0011] Obtain the complete charging voltage curve of the battery at the initial stage of its life cycle;

[0012] Fit the complete charging voltage curve of the battery at the initial stage of its life cycle through a time series model of random walk to obtain the battery charging process model.

[0013] In an alternative embodiment of the present application, fitting the complete charging voltage curve of the battery at the initial stage of its life cycle through a time series model of random walk to obtain the battery charging process model includes:

[0014] Fit the complete charging voltage curve of the battery at the initial stage of its life cycle through a time series model of random walk to obtain the variation of the kernel function at different charging voltages, so as to obtain the battery charging process model.

[0015] In an alternative embodiment of the present application, the expression of the battery charging process model is as follows:

[0016] y t = α + y t-1 + e t

[0017] where t is the current moment, t - 1 is the previous moment, α is a constant, y is the charging voltage, and e t is the kernel function.

[0018] In an alternative embodiment of the present application, according to the actual charging voltage curve of the battery, using the battery charging process model to obtain the complete charging voltage prediction curve of the battery includes:

[0019] According to the terminal voltage of the actual charging voltage curve of the battery, use the battery charging process model to obtain the complete charging voltage prediction curve of the battery.

[0020] In an alternative embodiment of the present application, according to the terminal voltage of the actual charging voltage curve of the battery, using the battery charging process model to obtain the complete charging voltage prediction curve of the battery includes:

[0021] According to the initial charging voltage of the actual charging voltage curve of the battery, use the battery charging process model to predict the first charging voltage curve segment from the initial charging voltage to the discharge cut-off voltage when the battery is fully discharged;

[0022] According to the terminal charging voltage of the actual charging voltage curve of the battery, use the battery charging process model to predict the second charging voltage curve segment from the terminal charging voltage to the charging cut-off voltage when the battery is fully charged;

[0023] Obtain the complete charging voltage prediction curve of the battery based on the actual charging voltage curve of the battery, the first charging voltage curve segment, and the second charging voltage curve segment.

[0024] In an alternative embodiment of the present application, the battery charging conditions corresponding to the complete charging voltage curve of the battery in the initial stage of the life cycle are the same as those of the actual charging voltage curve of the battery.

[0025] In an alternative embodiment of the present application, the battery is a single lithium battery.

[0026] To achieve the above object and other related objects, the present application provides a battery discharge voltage curve estimation device, including:

[0027] A first curve acquisition module, configured to collect the complete charging data of the battery in the initial stage of the battery life cycle to obtain the complete charging voltage curve of the battery in the initial stage of the life cycle;

[0028] A charging model construction module, configured to obtain a battery charging process model according to the complete charging voltage curve of the battery in the initial stage of the life cycle;

[0029] A second curve acquisition module, configured to collect the actual charging data of the battery to obtain the actual charging voltage curve of the battery;

[0030] A charging curve prediction module, configured to obtain the complete charging voltage prediction curve of the battery by using the battery charging process model according to the actual charging voltage curve of the battery.

[0031] To achieve the above object and other related objects, the present application provides a battery state estimation method, including:

[0032] Collect the complete charging data of the battery in the initial stage of the battery life cycle to obtain the complete charging voltage curve of the battery in the initial stage of the life cycle;

[0033] Obtain a battery charging process model according to the complete charging voltage curve of the battery in the initial stage of the life cycle;

[0034] Collect the actual charging data of the battery to obtain the actual charging voltage curve of the battery;

[0035] Obtain the complete charging voltage prediction curve of the battery by using the battery charging process model according to the actual charging voltage curve of the battery;

[0036] Estimate the battery state according to the complete charging voltage prediction curve of the battery.

[0037] Based on the complete charging voltage curve of the battery in the initial stage of the life cycle, a battery charging process model is constructed, and according to the actual charging voltage curve of the battery, the constructed battery charging process model is used for fitting to obtain a battery complete charging voltage prediction curve that can accurately reflect the current complete charging state of the battery; based on the obtained battery complete charging voltage prediction curve, the battery state can be accurately estimated. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic flowchart of a method for estimating a battery charging voltage curve in a specific embodiment of the present application.

[0039] Figure 2 It is the complete charging voltage curves of the same single lithium battery in different charge-discharge cycles under the same charging conditions.

[0040] Figure 3 It is the time-normalized complete charging voltage curves of the same single lithium battery in different charge-discharge cycles under the same charging conditions.

[0041] Figure 4 It is the actual charging voltage curve of the single lithium battery.

[0042] Figure 5 It is the battery complete charging voltage prediction curve of the single lithium battery estimated by the battery charging voltage curve estimation method based on this embodiment.

[0043] Figure 6 It is a comparison diagram of the battery complete charging voltage prediction curve and the actual curve of the battery complete charging voltage of the single lithium battery estimated by the battery charging voltage curve estimation method based on this embodiment.

[0044] Figure 7 It is a functional module diagram of a battery charging voltage curve estimation device in a specific embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] The following uses specific specific examples to illustrate the implementation manners of the present application. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. The present application can also be implemented or applied through other different specific implementation manners, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application.

[0046] As Figure 1 shown, the embodiments of the present application disclose a method for estimating a battery charging voltage curve, including the following steps:

[0047] Step S10, collect the battery complete charging data in the initial stage of the battery life cycle to obtain the battery complete charging voltage curve in the initial stage of the life cycle;

[0048] Step S20, obtaining a battery charging process model according to a battery complete charging voltage curve at the beginning of life (BOL);

[0049] Step S30, collecting actual charging data of the battery to obtain an actual charging voltage curve of the battery;

[0050] Step S40, according to the actual charging voltage curve of the battery, using the battery charging process model to obtain a battery complete charging voltage estimation curve.

[0051] Through the battery charging voltage curve estimation method of the present application, the battery complete charging voltage estimation curve reflecting the current battery complete charging state can be accurately obtained without fully charging and discharging the battery, and the battery state can be accurately estimated using the predicted battery complete charging voltage curve.

[0052] The following will take a single lithium battery as an example to explain in detail the battery charging voltage curve estimation process of the present application. Of course, the battery charging voltage curve estimation method of this embodiment can also be applied to other types of batteries.

[0053] First, execute step S10 and step S20 to collect battery complete charging data at the beginning of the battery life cycle to obtain the battery complete charging voltage curve at the beginning of the battery life cycle; obtain the battery charging process model based on the battery complete charging voltage curve at the beginning of the battery life cycle.

[0054] As the charge and discharge cycle of a single lithium battery (also called a lithium battery cell) progresses, the lithium inside the single lithium battery breaks down, the SEI (Solid Electrolyte Interface) membrane thickens, and the available capacity of the single lithium battery decreases. Under the same charging conditions, a single lithium battery can be charged to the full charge cut-off voltage in a shorter time.

[0055] As the battery capacity changes during aging, the charging time changes. When charging single lithium batteries of different aging degrees under the same charging conditions, the charging time of the battery at the beginning of the life cycle is long, while the charging time of the aged battery is shortened. Figure 2 The figure shows the complete charging voltage curve of the same single lithium battery under the same charging conditions when it is charged and discharged for 1, 50 and 100 cycles. Figure 2It can be seen that as the number of charge-discharge cycles of a single lithium battery increases, the actual complete charging voltage curve of the single lithium battery moves to the upper left, and the charging time for the single lithium battery to charge from the lowest battery voltage (defined as the discharge cut-off voltage at full discharge) of 3.1V to the highest battery voltage of 4.23V (defined as the charging cut-off voltage at full charge) becomes shorter. However, the voltage platform characteristics of the single lithium battery in different voltage segments do not change with the change of battery capacity, indicating that during the normal aging process of the battery, the lithium deintercalation and intercalation characteristics of the battery do not change. Physically, the charging voltage curve of the battery can be estimated based on the voltage platform characteristics of the battery. It should be noted that for different types of single lithium batteries, the charging cut-off voltage at full charge and the discharge cut-off voltage at full discharge are different.

[0056] By means of time coefficient normalization, for Figure 2 each complete charging voltage curve in, divide each charging moment by the total duration of the complete charging voltage curve to obtain the normalized time from 0 to 1, so as to obtain, as Figure 3 shown, the time coefficient normalized complete charging voltage curves of the same single lithium battery at 1 cycle, 50 cycles and 100 cycles of charge-discharge under the same charging conditions. From Figure 3 this, it can be seen that for single lithium batteries with different charge-discharge cycles, after time coefficient normalization, it can be seen that the voltage platforms of the aged single lithium batteries are basically the same. Single lithium batteries with different numbers of charge-discharge cycles have the same number of voltage platforms and the same voltage platform positions.

[0057] It can be seen from this that the charging curve of a lithium battery is only related to the materials of the positive and negative electrodes of the lithium battery. The voltage platform of the charging curve is related to the phase change and the rate at which lithium ions in the lithium battery are deintercalated from the positive electrode and then intercalated into the negative electrode during charging, and the compounds formed. The voltage platform is not affected by the normal aging of lithium ions and changes in external characteristics, such as the temperature of the lithium battery, the charging rate, the capacity of the lithium battery, the charge-discharge depth, etc. When the external characteristics change, the slope of the charging curve will change, but there will be no movement or disappearance of the voltage platform. The complete charging voltage curve at the initial stage of the intrinsic life cycle of the lithium battery can be used as a template for estimating the charging voltage curve of the entire single lithium battery life cycle. Based on this principle, the complete charging data of the battery at the initial stage of the life cycle can be collected to obtain the complete charging voltage curve of the battery at the initial stage of the life cycle; and according to the complete charging voltage curve of the battery at the initial stage of the life cycle, a battery charging process model can be constructed as a model for estimating the charging voltage curve of the entire single lithium battery life cycle.

[0058] In this embodiment, when obtaining the battery charging process model according to the complete charging voltage curve of the battery in the initial stage of the life cycle, the complete charging voltage curve of the battery with the same specification as the single lithium battery to be predicted or in the initial stage of its own life cycle can be obtained from historical data. For example, the complete charging voltage curve of the battery after 1 charge and discharge cycle (of course, it can also be any number from 2 to 10). The complete charging voltage curve of the battery in the initial stage of the life cycle is fitted by a time series model of random walk to obtain the battery charging process model.

[0059] Among them, random walk makes predictions about the data points at the next moment based on the data at the previous moment. The expression of the battery charging process model is as follows:

[0060] y t =α + y t-1 + e t

[0061] Among them, t is the current moment, t - 1 is the previous moment, α is a constant, y is the charging voltage, and e t is the kernel function related to the charging voltage.

[0062] It can be seen from this that when fitting the complete charging voltage curve of the battery in the initial stage of the life cycle by a time series model of random walk to obtain the battery charging process model, it is actually fitting the complete charging voltage curve of the battery in the initial stage of the life cycle by a time series model of random walk to obtain the changes of the kernel function at different charging voltages and the constant α, so as to obtain the battery charging process model.

[0063] Next, step S30 is executed to collect the actual charging data of the battery to obtain the actual charging voltage curve of the battery. Among them, the actual charging voltage curve of the battery refers to the battery charging voltage curve when it is not fully charged, also known as the incomplete battery charging voltage curve. Figure 4 shows the actual charging voltage curve of the single lithium battery when the charging range is 20% - 80% SOC (State of Charge) ( Figure 4 the curve represented by original values in).

[0064] The single lithium battery to be predicted is the same as the single lithium battery when obtaining the battery charging process model, or a single lithium battery of the same specification, and the corresponding battery charging conditions need to be kept basically the same, so that the accuracy of the predicted complete charging voltage estimation curve of the battery based on the battery charging process model can be higher in the follow-up. Of course, in other embodiments, the single lithium battery to be predicted is the same as the single lithium battery when obtaining the battery charging process model, or a single lithium battery of the same specification, but the battery charging conditions can also be inconsistent.

[0065] Finally, step S40 is performed to obtain a battery full charging voltage estimation curve based on the actual battery charging voltage curve using the battery charging process model. After obtaining the actual battery charging voltage curve, the terminal voltage of the actual battery charging voltage curve can be obtained first, and then the battery full charging voltage estimation curve can be obtained based on the terminal voltage of the actual battery charging voltage curve using the battery charging process model.

[0066] The terminal voltage includes a first-end charging voltage at the beginning of actual charging and a tail-end charging voltage at the end of actual charging, wherein the first-end charging voltage and the tail-end charging voltage may be a single charging voltage at the first and last ends of the actual charging voltage curve of the battery, or may be a collection of multiple charging voltages at the first and last ends of the actual charging voltage curve of the battery.

[0067] According to the terminal voltage of the actual charging voltage curve of the battery, using the battery charging process model to obtain a battery complete charging voltage estimation curve may further include:

[0068] According to the head end charging voltage of the actual charging voltage curve of the battery, the battery charging process model is used to predict a first charging voltage curve segment from the head end charging voltage to the discharge cut-off voltage when the battery is fully discharged; according to the tail end charging voltage of the actual charging voltage curve of the battery, the battery charging process model is used to predict a second charging voltage curve segment from the tail end charging voltage to the charging cut-off voltage when the battery is fully charged; based on the actual charging voltage curve of the battery, the first charging voltage curve segment and the second charging voltage curve segment, the battery complete charging voltage estimation curve is obtained by splicing.

[0069] After the battery full charging voltage estimation curve is obtained, the battery state estimation can be performed according to the battery full charging voltage estimation curve.

[0070] by Figure 4 Taking the actual charging voltage curve of a single lithium battery as an example, the charging voltage at the first end is 3.6V and the charging voltage at the tail end is 4.1V. The charging voltage at the first end is 3.6V and the charging voltage at the tail end is 4.1V. The charging voltage at the first end is 3.6V and the charging voltage at the tail end is 4.1V. The charging voltage at the previous moment is estimated with 3.6V as the starting point until the discharge cut-off voltage is 3.1V. Similarly, the charging voltage at the next moment is estimated with 4.1V as the starting point until the charging cut-off voltage is 4.25V. Then, the predicted two charging voltage curve segments ( Figure 5 The curve represented by the estimated values ​​in the figure) and the actual charging voltage curve of the battery ( Figure 5 The curve represented by the original values ​​in ) is spliced ​​to obtain Figure 5 The complete charging voltage estimation curve of a single lithium battery is shown.Figure 6 The comparison diagram of the estimated curve of the complete charging voltage of a single lithium battery (the curve represented by the estimate values in Figure 6 ) and the actual curve of the complete charging voltage of the battery (the curve represented by the original values in Figure 6 ). It can be seen from the figure that the voltage platform of the single lithium battery has not changed, and the estimated curve of the complete charging voltage of the battery is very close to the actual curve of the complete charging voltage of the battery. Therefore, the battery state is accurately estimated based on the estimated curve of the complete charging voltage of the battery.

[0071] Figure 7 This is a functional module diagram of the battery discharge voltage curve estimation device 11 provided in the embodiment of the present application. Please refer to Figure 7 . The battery discharge voltage curve estimation device 11 includes a first curve acquisition module 111, a charging model construction module 112, a second curve acquisition module 113, and a charging curve estimation module 114.

[0072] Among them, the first curve acquisition module 111 is used to collect the complete charging data of the battery at the initial stage of the battery life cycle to obtain the complete charging voltage curve of the battery at the initial stage of the life cycle; the charging model construction module 112 is used to obtain the battery charging process model according to the complete charging voltage curve of the battery at the initial stage of the life cycle; the second curve acquisition module 113 is used to obtain the actual charging voltage curve of the battery; the charging curve estimation module 114 is used to obtain the estimated curve of the complete charging voltage of the battery according to the actual charging voltage curve of the battery by using the battery charging process model.

[0073] It should be noted that the battery discharge voltage curve estimation device in this embodiment is a device corresponding to the above battery discharge voltage curve estimation method. The functional modules in the battery discharge voltage curve estimation device respectively correspond to the corresponding steps in the battery discharge voltage curve estimation method. The battery discharge voltage curve estimation device in this embodiment can be implemented in cooperation with the battery discharge voltage curve estimation method. Correspondingly, the relevant technical details mentioned in the battery discharge voltage curve estimation device in this embodiment can also be applied to the above battery discharge voltage curve estimation method.

[0074] It should be noted that in actual implementation, all or part of the above functional modules can be integrated into one physical entity or physically separated. And these modules can all be implemented in the form of software called by a processing element; they can also all be implemented in the form of hardware; or some modules can be implemented in the form of software called by a processing element and some modules can be implemented in the form of hardware. In addition, all or part of these modules can be integrated together or can be independently implemented. The processing element mentioned here can be an integrated circuit with signal processing capabilities. In the implementation process, part or all of the steps of the above method, or each of the above functional modules, can be completed by the integrated logic circuit in the processor element or the instructions in the form of software.

[0075] In summary, the battery charging voltage curve estimation method and device of the present application are based on the complete charging voltage curve of the battery in the initial stage of the life cycle, construct a battery charging process model, and according to the actual charging voltage curve of the battery, use the constructed battery charging process model to predict the complete charging voltage prediction curve of the battery; and the complete charging voltage prediction curve of the battery can accurately reflect the complete charging state of the current battery state and can be used as input data for accurate battery state estimation.

[0076] In the description herein, numerous specific details are provided, such as examples of components and / or methods, to provide a complete understanding of embodiments of the present application. However, those skilled in the art will recognize that embodiments of the present application can be practiced without one or more of the specific details or by other devices, systems, components, methods, parts, materials, parts, etc.

[0077] It should also be understood that one or more of the elements shown in the drawings can also be implemented in a more separated or more integrated manner, or even removed because they cannot be operated in some cases or provided because they are useful for a specific application.

[0078] In addition, unless otherwise clearly specified, any marked arrows in the drawings should be regarded as exemplary only and not restrictive. In addition, unless otherwise specified, the term "or" used herein generally intends to mean "and / or". In cases where the separation or combination ability of the terms is unclear and foreseeable, the combination of components or steps will also be regarded as having been specified.

[0079] The foregoing description of the embodiments shown in this application (including what is described in the abstract of the specification) is not intended to be exhaustive or to limit the application to the precise forms disclosed herein. While specific embodiments of the application and examples of the application have been described herein for illustrative purposes only, various equivalent modifications will be apparent to and can be made by those skilled in the art within the spirit and scope of the application. As noted, these modifications can be made to the application in accordance with the foregoing description of the embodiments of the application, and these modifications will be within the spirit and scope of the application.

[0080] The systems and methods have been described generally herein to facilitate an understanding of the details of the application. Additionally, various specific details have been given to provide an overall understanding of embodiments of the application. However, one of ordinary skill in the relevant art will recognize that embodiments of the application may be practiced without one or more of the specific details, or with other devices, systems, components, methods, materials, parts, etc. In other instances, well-known structures, materials, and / or operations have not been shown or described in detail to avoid obscuring aspects of the embodiments of the application.

[0081] Accordingly, while the application has been described herein with reference to its specific embodiments, modifications, various changes, and substitutions are also within the foregoing disclosure, and it is to be understood that in some instances, some features of the application may be employed without a corresponding use of other features without departing from the scope and spirit of the claimed invention. Accordingly, many modifications may be made to adapt a particular environment or material to the essential scope and spirit of the application. The application is not intended to be limited to the specific terms and / or the specific embodiments disclosed as the best mode contemplated for carrying out the application, but the application will include any and all embodiments and equivalents falling within the scope of the appended claims. Accordingly, the scope of the application is to be determined only by the appended claims.

Claims

1. A method for estimating a battery charging voltage curve, characterized in that, Including: Collecting the complete charging data of the battery at the initial stage of the battery life cycle to obtain the complete charging voltage curve of the battery at the initial stage of the life cycle; Obtaining a battery charging process model according to the complete charging voltage curve of the battery at the initial stage of the life cycle; Collecting the actual charging data of the battery to obtain the actual charging voltage curve of the battery; According to the actual charging voltage curve of the battery, using the battery charging process model to obtain the predicted curve of the complete charging voltage of the battery.

2. The method for estimating the battery charging voltage curve according to claim 1, wherein Obtaining a battery charging process model according to the complete charging voltage curve of the battery at the initial stage of the life cycle, including: Obtaining the complete charging voltage curve of the battery at the initial stage of the life cycle; Fitting the complete charging voltage curve of the battery at the initial stage of the life cycle by a time series model of random walk to obtain the battery charging process model.

3. The method for estimating the battery charging voltage curve according to claim 1, wherein Fitting the complete charging voltage curve of the battery at the initial stage of the life cycle by a time series model of random walk to obtain the battery charging process model, including: Fitting the complete charging voltage curve of the battery at the initial stage of the life cycle by a time series model of random walk, obtaining the change of the kernel function at different charging voltages, and obtaining the battery charging process model.

4. The method for estimating the battery charging voltage curve according to claim 3, wherein The expression of the battery charging process model is as follows: y t = α + y t-1 + e t where t is the current time, t - 1 is the previous time, α is a constant, y is the charging voltage, and e t is the kernel function.

5. The method for estimating the battery charging voltage curve according to claim 3, wherein According to the actual charging voltage curve of the battery, using the battery charging process model to obtain the predicted curve of the complete charging voltage of the battery, including: According to the terminal voltage of the actual charging voltage curve of the battery, using the battery charging process model to obtain the predicted curve of the complete charging voltage of the battery.

6. The charging voltage curve estimation method according to claim 5, characterized in that According to the terminal voltage of the actual charging voltage curve of the battery, using the battery charging process model to obtain the predicted curve of the complete charging voltage of the battery, including: According to the initial charging voltage of the actual charging voltage curve of the battery, using the battery charging process model to predict the first charging voltage curve segment from the initial charging voltage to the discharge cut-off voltage when the battery is fully discharged; According to the terminal charging voltage of the actual charging voltage curve of the battery, using the battery charging process model to predict the second charging voltage curve segment from the terminal charging voltage to the charge cut-off voltage when the battery is fully charged; Based on the actual charging voltage curve of the battery, the first charging voltage curve segment and the second charging voltage curve segment, obtaining the predicted curve of the complete charging voltage of the battery.

7. The method for estimating a battery charging voltage curve according to claim 1, wherein The complete charging voltage curve of the battery at the initial stage of the life cycle is consistent with the battery charging conditions corresponding to the actual charging voltage curve of the battery.

8. The method for estimating a battery charging voltage curve according to claim 1, wherein The battery is a single lithium battery.

9. A battery discharge voltage curve estimation device, characterized in that Including: A first curve acquisition module, configured to collect the complete charging data of the battery at the initial stage of the battery life cycle to obtain the complete charging voltage curve of the battery at the initial stage of the life cycle; A charging model construction module, configured to obtain a battery charging process model according to the complete charging voltage curve of the battery at the initial stage of the life cycle; A second curve acquisition module, configured to collect the actual charging data of the battery to obtain the actual charging voltage curve of the battery; A charging curve prediction module, configured to obtain the predicted curve of the complete charging voltage of the battery according to the actual charging voltage curve of the battery and using the battery charging process model.

10. A battery state estimation method, characterized in that, Including: Collect the complete charging data of the battery at the initial stage of its life cycle to obtain the complete charging voltage curve of the battery at the initial stage of its life cycle; Obtain the battery charging process model based on the complete charging voltage curve of the battery at the initial stage of its life cycle; Collect the actual charging data of the battery to obtain the actual charging voltage curve of the battery; Based on the actual charging voltage curve of the battery, use the battery charging process model to obtain the estimated complete charging voltage curve of the battery; Estimate the battery state based on the estimated complete charging voltage curve of the battery.

Images