Battery state detection method and device, equipment, storage medium and program product

Abstract

The embodiment of the invention provides a battery state detection method and device, equipment, a storage medium and a program product. The method comprises the steps of obtaining the thickness of a battery pole piece of a target battery and the SOH of the battery, and obtaining the SOC of the target battery according to the thickness of the battery pole piece and the SOH. According to the method, the accuracy of SOC detection can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery status detection method, device, equipment, storage medium and program product. Background Art

[0002] As people pay more and more attention to environmental protection and low carbon, the pace of development of new energy vehicles has also accelerated significantly. The integration of automobiles with related technologies in the fields of energy, transportation, information and communication has accelerated, and electrification, networking and intelligence have become the development trend and trend of the automobile industry. New technologies for new energy vehicles have sprung up like mushrooms after a rain, for example: the application number is CN202410658157.7, the publication number is CN118238797B, and the invention name is new energy vehicle energy intelligent management system, control method and related equipment; the application number is CN202410672579.X, the publication number is CN118597091A, and the invention name is new energy vehicle energy intelligent management method, system and related equipment; the application number is 202410669449.0, and the invention name is new energy vehicle energy intelligent management system, control method and related equipment. The above applications all describe hybrid technology based on electricity, which has multiple advantages such as fast, economical, quiet, smooth and green. For example: the application number is CN202211678720.4, the publication number is CN117382629B, and the invention name is vehicle power control method, device, medium, vehicle controller and vehicle; the application number is CN202311164098.X, the publication number is CN116890770B, and the invention name is vehicle control system, method and vehicle; the application number is CN202311170393.6, the publication number is CN117533292B, and the invention name is vehicle control system, control method, controller and vehicle. The above applications all describe a new energy power system with four wheel-side motors independently driven as the core, which greatly improves the safety and power of new energy vehicles.

[0003] For new energy vehicles, they mainly rely on batteries for power. For batteries, the battery state (State of Charge, SOC) is an important status indicator of the battery. SOC essentially reflects the amount of remaining power in the battery. Accurately knowing the battery's SOC is related to the overall performance, safety, and life of the battery. The power performance and economy of new energy vehicles are closely related to the state of the battery. Accurately estimating the SOC can have a more accurate application of the battery power state (State of Power, SOP), thereby effectively improving the power economy of the whole vehicle and the battery life. However, the current method of detecting SOC through the open circuit voltage (Open Circuit Voltage, OCV)-SOC lookup table method and the ampere-hour integration method has the problem of low accuracy.

[0004] Therefore, how to improve the accuracy of SOC detection is an urgent problem to be solved. Summary of the invention

[0005] The embodiments of the present application provide a battery status detection method, device, equipment, storage medium and program product to achieve the effect of improving the accuracy of SOC detection.

[0006] In a first aspect, an embodiment of the present application provides a battery status detection method, comprising:

[0007] Obtain the battery electrode thickness of the target battery and the battery health status SOH;

[0008] The battery state SOC of the target battery is obtained according to the battery electrode thickness and the SOH.

[0009] In a second aspect, an embodiment of the present application provides a battery status detection device, including:

[0010] An acquisition module is used to obtain the battery electrode thickness of the target battery and the battery health status SOH;

[0011] A processing module is used to obtain the battery state SOC of the target battery according to the battery electrode thickness and the SOH.

[0012] In a third aspect, an embodiment of the present application provides an electronic device, including: a memory, a processor;

[0013] The memory stores computer-executable instructions;

[0014] The processor executes the computer-executable instructions stored in the memory, so that the processor executes the above first aspect and / or various possible implementations of the first aspect.

[0015] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the first aspect above and / or various possible implementations of the first aspect.

[0016] In a fifth aspect, an embodiment of the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the above first aspect and / or various possible implementation methods of the first aspect.

[0017] The battery status detection method, device, equipment, storage medium and program product provided in the embodiments of the present application obtain the battery electrode thickness and SOH of the target battery, and obtain the SOC of the target battery based on the battery electrode thickness and SOH. Compared with the prior art, it can not only accurately detect the SOC during the use of the battery, but also reduce the problem of poor SOC detection accuracy caused by factors such as current collection deviation and initial SOC deviation, thereby improving the accuracy of battery SOC detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0019] Figure 1 A flowchart of a battery status detection method provided in an embodiment of the present application;

[0020] Figure 2 A flowchart of another battery status detection method provided in an embodiment of the present application;

[0021] Figure 3 A schematic diagram of a mapping relationship provided in an embodiment of the present application;

[0022] Figure 4 A flowchart of another battery status detection method provided in an embodiment of the present application;

[0023] Figure 5 A flowchart of another battery status detection method provided in an embodiment of the present application;

[0024] Figure 6 A schematic diagram of another mapping relationship provided in an embodiment of the present application;

[0025] Figure 7 A flowchart of another battery status detection method provided in an embodiment of the present application;

[0026] Figure 8 A schematic diagram of the structure of a battery status detection device provided in an embodiment of the present application;

[0027] Fig. 9 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0028] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0029] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0030] First, the professional terms involved in the embodiments of the present application are introduced:

[0031] Battery State of Charge (SOC): refers to the ratio of the remaining power in the battery to the rated capacity of the battery, usually expressed as a percentage. For example, if a battery has a rated capacity of 100Ah and the current remaining power is 50Ah, then its SOC is 50%.

[0032] Battery Health of Charge (SOH): refers to an indicator that measures the health of a battery, usually defined as the ratio of the actual available capacity of the battery to the initial rated capacity of the battery, usually expressed as a percentage. For example, if the initial rated capacity of a battery is 100Ah, and after a period of use, the actual available capacity becomes 80Ah, then its SOH is 80%.

[0033] At present, the SOC is mainly detected through the OCV-SOC table lookup method and the ampere-hour integration method to obtain the battery SOC.

[0034] The open circuit voltage lookup table method is based on a specific relationship between OCV and SOC, and evaluates SOC through OCV. This method can avoid the problems of the ampere-hour integration method. However, polarization occurs when the battery is charged and discharged. OCV needs to wait for the battery to stand for a period of time to remove polarization before the accurate open circuit voltage value can be determined. Therefore, it is impossible to use OCV in real time to evaluate SOC during battery use (such as during the driving of electric vehicles). In addition, lithium iron phosphate batteries have a voltage platform area, that is, there is a problem that the OCV and SOC characteristic curves are not obvious. In this area, the open circuit voltage lookup table method cannot be used to obtain SOC.

[0035] The ampere-hour integration method obtains the charge and discharge capacity by integrating the current over time, and calculates the current SOC based on the accumulated charge and discharge capacity based on the initial SOC. However, the ampere-hour integration method requires a high accuracy of the initial SOC value. If there is an error in the initial SOC value, the SOC values ​​obtained by subsequent integration will deviate. In this case, there is a risk that the charge and discharge power value based on the wrong SOC will exceed the battery's operating capacity, thereby affecting the battery life and causing battery safety problems. In addition, if the current sensor is interfered by the environment, zero drift and unknown factors, resulting in inaccurate current sampling, there will also be cumulative errors during time integration, resulting in a large deviation in the obtained SOC.

[0036] During the research process, the applicant discovered that the thickness of the battery electrode of the battery will change synchronously with the SOC and SOH of the battery, and the change is relatively stable. In view of this, the present application provides a battery status detection method, by obtaining the battery electrode thickness and SOH of the target battery, and obtaining the SOC of the target battery according to the battery electrode thickness and SOH. Compared with the prior art, the SOC can be accurately detected during the use of the battery, and the problem of poor SOC detection accuracy caused by factors such as current acquisition deviation and initial SOC deviation can be reduced, thereby improving the accuracy of battery SOC detection.

[0037] The execution subject of the battery status detection method provided in the present application may be a terminal device with data processing function, or a processing chip of the terminal device, or software or program code for implementing the data processing method. When the execution subject is a terminal device with data processing function, the terminal device may be, for example, a computing device such as a computer or a mobile phone with computing function, and the computing device may be deployed with software or program code for running the battery status detection method, and the battery SOC is detected through the software or program code.

[0038] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below through specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0039] Figure 1 A flowchart of a battery status detection method provided in an embodiment of the present application. Figure 1 As shown, the method includes:

[0040] S101, obtaining the battery electrode thickness and SOH of the target battery.

[0041] The battery electrode thickness can be, for example, the electrode thickness of the positive electrode of the battery or the electrode thickness of the negative electrode of the battery. During the charge and discharge process of the target battery, the battery electrode will expand and deform, resulting in different battery electrode thicknesses when the target battery is at different SOCs and SOHs.

[0042] The thickness of the battery pole piece can be acquired in real time by a pole piece thickness collector pre-installed inside the battery cell, and the pole piece thickness collector can be, for example, a resistive strain gauge, an optical sensor (collecting the thickness of the battery pole piece by optical measurement method), etc. Alternatively, the thickness of the battery pole piece can be acquired by a capacitive measurement method, for example, the battery pole piece is used as a plate of a capacitor, and the thickness of the battery pole piece is determined according to the change in the capacitance value of the capacitor.

[0043] The SOH of the target battery can be obtained from a battery management system (BMS), or based on battery operation data, using a deep learning model that predicts SOH, etc. The SOH of the target battery can be obtained in real time during the charge and discharge process of the target battery, or based on a preset time interval, or based on a preset number of charge and discharge times, etc., as long as it can represent the current SOH of the target battery.

[0044] S102, obtaining the SOC of the target battery according to the battery electrode thickness and SOH.

[0045] In this step, the SOC of the target battery can be obtained according to the thickness of the battery electrode and the SOH. Alternatively, the change of the thickness of the battery electrode (such as the expansion rate and change rate of the thickness of the battery electrode) can be obtained according to the thickness of the battery electrode, and then the SOC of the target battery can be obtained according to the change of the thickness of the battery electrode and the SOH.

[0046] A possible implementation method is to obtain the SOC of the target battery based on the battery electrode thickness, SOH, and a pre-built mapping relationship. The mapping relationship is a mapping relationship between the battery electrode thickness, SOH, and SOC, for example, a mapping data table or a function curve including the mapping relationship between the battery electrode thickness, SOH, and SOC. After obtaining the battery electrode thickness and SOH of the target battery, the SOC can be obtained using the pre-built mapping relationship.

[0047] The mapping relationship may be obtained by measuring the thickness of the battery pole piece of the target battery or the battery of the same model as the target battery under different SOC and SOH conditions. For example, in a laboratory environment, different initial SOC values ​​(such as 10%, 20%, 30%, etc.) and different SOH values ​​(simulated by aging the battery to different degrees) may be set, and the corresponding battery pole piece thickness may be measured to obtain the mapping relationship.

[0048] Another possible implementation method is to obtain the SOC of the target battery through a pre-trained machine learning model. That is, the battery pole thickness and SOH are used as model inputs, and the predicted SOC is output by the pre-trained machine learning model. The machine learning model can be, for example, a neural network model, a decision tree model, a vector machine model, etc., and the present application does not limit this. Specifically, the battery pole thickness corresponding to the target battery or the battery of the same model as the target battery under different SOC and SOH conditions can be obtained, and these data are used as training data to train the machine learning model to obtain a prediction model that can predict the SOC based on the battery pole thickness and SOH.

[0049] The method provided in the embodiment of the present application obtains the battery electrode thickness and SOH of the target battery, and obtains the SOC of the target battery based on the battery electrode thickness and SOH. Compared with the prior art, it can not only accurately detect the SOC during the use of the battery, but also reduce the problem of poor SOC detection accuracy caused by factors such as current collection deviation and initial SOC deviation, thereby improving the accuracy of SOC detection of the battery.

[0050] Next, taking the example of obtaining the expansion rate of the battery electrode sheet through the thickness of the battery electrode sheet, how to obtain the battery state SOC of the target battery according to the thickness of the battery electrode sheet and SOH in the aforementioned step S102 is described in detail. Figure 2 A flowchart of another battery status detection method provided in an embodiment of the present application. Figure 2 As shown, the aforementioned step S102 may specifically include:

[0051] S201. Obtain the expansion rate of the target battery according to the battery electrode thickness and SOH.

[0052] Among them, the expansion rate of the target battery is actually the expansion rate of the current battery electrode thickness based on a certain reference thickness (also referred to as the electrode reference thickness). The reference thickness can be, for example, the battery electrode thickness at a specific SOC under a preset SOH, or a preset thickness value, etc.

[0053] Since the battery electrode will expand and deform during the charge and discharge process of the target battery, the battery electrode thickness is different when the target battery is at different SOC and SOH. Therefore, under different SOH, the expansion rate of the battery electrode thickness based on the reference electrode thickness is also different. Based on this, the correlation between the battery electrode thickness, SOH and the expansion rate of the target battery can be constructed.

[0054] One possible implementation method is to construct different associations between the thickness of the battery electrode and the expansion rate of the target battery for different SOHs. For example, when the SOH is 100%, association 1 is used, and when the SOH is 50%, association 2 is used. Based on the association corresponding to the SOH and the thickness of the battery electrode, the expansion rate of the target battery can be obtained.

[0055] Another possible implementation method is to correspond to different reference thicknesses of the electrode under different SOH. The expansion rate of the battery electrode thickness based on the reference thickness of the electrode is calculated by the reference thickness of the electrode corresponding to the SOH and the thickness of the battery electrode. This implementation method can be specifically implemented through the following sub-steps:

[0056] S2011. Obtain the reference thickness of the electrode according to SOH.

[0057] One possible implementation method is to obtain the reference thickness of the pole piece through the pre-stored association between SOH and the reference thickness of the pole piece, and SOH. For example, when SOH is 100%, the reference thickness of the pole piece is 1 mm, when SOH is 10%, the reference thickness of the pole piece is 0.2 mm, and so on.

[0058] Another possible implementation method is that different SOHs correspond to different electrode thickness coefficients. The electrode reference thickness is obtained based on the electrode thickness coefficients corresponding to different SOHs and a preset reference battery electrode thickness (which can be set according to actual needs, such as a preset thickness value, or the electrode thickness of the battery in a preset state, etc.).

[0059] S2012. Obtain the expansion rate of the target battery according to the battery electrode thickness and the electrode reference thickness.

[0060] Specifically, the electrode thickness difference can be determined based on the difference between the battery electrode thickness and the electrode reference thickness. Then, the expansion rate is determined based on the electrode thickness difference and the electrode reference thickness. At this time, the expansion rate of the target battery represents the expansion ratio of the battery electrode thickness of the target battery compared to the electrode reference thickness. Exemplarily, the expansion rate of the target battery can be shown as the following formula (1):

[0061] (1)

[0062] in, is the expansion rate of the target battery, is the battery electrode thickness of the target battery at the current condition, is the reference thickness of the pole piece.

[0063] S202: Obtain the SOC of the target battery according to the expansion rate and the mapping relationship between the expansion rate and the SOC.

[0064] According to the expansion rate, the SOC corresponding to the expansion rate is determined in the mapping relationship between the expansion rate and the SOC, and the SOC is used as the SOC of the target battery.

[0065] For example, the mapping relationship between the expansion rate and the SOC is shown in Table 1 below:

[0066] Table 1

[0067]

[0068] If the expansion rate is 1.3%, then the SOC of the target battery can be determined to be 20%. It should be understood that Table 1 is only an example of a mapping relationship for ease of understanding and is not limiting. The mapping relationship can set data accuracy according to actual needs, for example, it can be subdivided into one expansion rate value for every 1% of SOC, or one expansion rate value for every 0.1% of SOC, etc., and this application does not limit this.

[0069] Optionally, as mentioned above, the mapping relationship may also be a functional relationship, and is not limited to the data table mapping form shown in Table 1.

[0070] For example, Figure 3 A schematic diagram of a mapping relationship provided in an embodiment of the present application. Figure 3 As shown, the mapping relationship is a functional relationship between the expansion rate of the battery pole piece thickness and the SOC. The functional relationship can be obtained by fitting multiple sets of test data under a certain SOH, and the test data includes the SOC and the expansion rate of the battery pole piece thickness. According to the SOH of the target battery, the functional relationship corresponding to the SOH is determined, and the expansion rate of the battery pole piece thickness is substituted into the functional relationship to obtain the SOC corresponding to the expansion rate of the battery pole piece thickness and the SOH.

[0071] The method provided in the embodiment of the present application obtains the expansion rate of the target battery through the thickness of the battery electrode and SOH, and obtains the SOC of the target battery based on the expansion rate and the mapping relationship between the expansion rate and SOC. This method has fewer influencing factors on the data required for detecting the SOC and has higher accuracy, thereby improving the accuracy of the battery's SOC detection.

[0072] Next, taking different SOHs corresponding to different pole piece thickness coefficients as an example, how to obtain the pole piece reference thickness according to the SOH in the aforementioned step S2011 is described in detail. Figure 4 A flowchart of another battery status detection method provided in an embodiment of the present application is shown below. Figure 4 As shown, the aforementioned step S2011 may specifically include:

[0073] S401. According to SOH, obtain a pole piece thickness coefficient corresponding to SOH.

[0074] The pole piece thickness coefficient is determined based on the battery pole piece thickness at different SOHs under the preset SOC, and the reference battery pole piece thickness. For example, the same type of battery as the target battery can be tested in advance to obtain the battery pole piece thickness at the preset SOC under different SOHs. The preset SOC can be set according to actual needs, for example, the preset SOC can be set to 100%, 20%, 0%, etc. The SOC corresponding to the reference battery pole piece thickness is also the preset SOC.

[0075] The reference battery electrode thickness is taken as an example, the SOH of the reference battery is 100%, and the corresponding battery electrode thickness when the reference battery is discharged to the cut-off voltage. Among them, when the reference battery is discharged to the cut-off voltage, the preset SOC is represented as 0%. Correspondingly, the calculation formula of the electrode thickness coefficient can be shown as the following formula (2):

[0076] (2)

[0077] in, is the pole piece thickness coefficient, To preset the battery electrode thickness of different SOH under SOC, It is the reference battery electrode thickness, that is, the battery electrode thickness corresponding to the SOH of 100% and discharged to the cut-off voltage.

[0078] S402, determining the reference thickness of the electrode under SOH according to the electrode thickness coefficient and the reference battery electrode thickness.

[0079] After determining the SOH of the target battery, the reference thickness of the electrode under the current SOH can be determined based on the product of the electrode thickness coefficient and the electrode thickness of the reference battery.

[0080] Continuing with the above formula (2) as an example, the above formula (2) can be obtained by transposing the terms to obtain the formula (3) which is equivalent to the above formula (2):

[0081] (3)

[0082] The SOH of the target battery can be substituted into the formula (3): , you can get the reference thickness of the electrode under the SOH of the target battery. For example, assuming the SOH of the target battery is 50%, you can get the corresponding electrode thickness coefficient when the SOH is 50%. , and the reference battery electrode thickness , get the reference thickness of the pole piece (That is, ).

[0083] In the above implementation, the formula (1) corresponding to the expansion rate of the target battery can be converted into the following formula (4):

[0084] (4)

[0085] That is, it is only necessary to calculate the expansion rate of the target battery based on the electrode thickness coefficient corresponding to the SOH and the reference battery electrode thickness.

[0086] The method provided in the embodiment of the present application obtains the electrode thickness coefficient corresponding to the SOH and, with reference to the battery electrode thickness, calculates the expansion rate of the battery electrode thickness of the target battery compared to the reference electrode thickness, thereby eliminating the influencing factors of different changes in battery electrode thickness caused by different SOH. Therefore, the expansion rate of the target battery can be obtained only based on the relationship between the electrode thickness coefficient and SOH obtained in advance and the reference battery electrode thickness, and further based on the expansion rate of the target battery and the mapping relationship between the expansion rate and SOC, the SOC of the target battery can be determined, thereby improving the efficiency and accuracy of detecting the battery SOC.

[0087] In one possible implementation, if the mapping relationship between the expansion rate and the SOC is stored in a mapping data table, and the data accuracy in the mapping relationship is lower than the actual data accuracy, it is impossible to directly query the corresponding SOC from the mapping data table based on the expansion rate. In this case, the SOC corresponding to the expansion rate can also be determined by calculating interpolation.

[0088] In this implementation, the mapping relationship between the expansion rate and the SOC includes: an expansion rate interval, a first SOC corresponding to a lower limit of the expansion rate interval, and a second SOC corresponding to an upper limit of the expansion rate interval, and the first SOC is less than the second SOC.

[0089] For example, taking the data in Table 1 above as an example, the mapping relationship between the expansion rate and the SOC may be as shown in Table 2 below:

[0090] Table 2

[0091]

[0092] Based on the above Table 2, the above step S202 may specifically include:

[0093] If the expansion rate is equal to the lower limit, the SOC of the target battery is equal to the first SOC. For example, taking the expansion rate range of 0.45%-1.3% as an example, the first SOC is 10%. When the expansion rate of the target battery is 0.45% (that is, the expansion rate is equal to the lower limit), the first SOC corresponding to the expansion rate is 10%.

[0094] If the expansion rate is equal to the upper limit, the SOC of the target battery is equal to the second SOC. For example, taking the expansion rate range of 0.45%-1.3% as an example, the first SOC is 20%. When the expansion rate of the target battery is 1.3% (that is, the expansion rate is equal to the upper limit), the second SOC corresponding to the expansion rate is 20%.

[0095] If the expansion rate is greater than the lower limit and less than the upper limit, the SOC of the target battery is obtained by interpolating between the first SOC and the second SOC. For example, taking the expansion rate interval of 0.45%-1.3% as an example, the first SOC is 10% and the second SOC is 20%. When the expansion rate of the target battery is 0.9% (i.e., the expansion rate is greater than the lower limit and less than the upper limit), the expansion rate interval and the expansion rate of the target battery can be interpolated to determine the position where the expansion rate of the target battery falls in the expansion rate interval. Since the expansion rate interval corresponds to the SOC interval, the position where the expansion rate of the target battery falls in the expansion rate interval corresponds to the position where the SOC of the target battery falls in the SOC interval. Based on the position where the expansion rate of the target battery falls in the expansion rate interval and the SOC interval, the SOC after interpolation calculation can be obtained, that is, the SOC corresponding to the expansion rate of the target battery. Among them, the interpolation calculation can be, for example, a linear interpolation calculation, or other interpolation calculation methods that can achieve the same effect.

[0096] Optionally, if the mapping relationship between the expansion rate and the SOC is stored in a mapping data table, and the data accuracy in the mapping relationship is lower than the actual data accuracy, it is impossible to directly query the corresponding SOC from the mapping data table according to the expansion rate, and the mapping data table can also be fitted into a corresponding function curve to determine the SOC corresponding to the expansion rate according to the function curve. For example, the mapping data table is fitted into a corresponding function curve to obtain a function relationship or a function image of the function curve, and the expansion rate of the target battery is substituted based on the function relationship or the function image to obtain the SOC corresponding to the expansion rate of the target battery.

[0097] The method provided in the embodiment of the present application uses an interpolation method or a curve fitting method. When the mapping relationship between the expansion rate and the SOC is stored in a mapping data table, and the data accuracy in the mapping relationship is lower than the actual data accuracy, and the corresponding SOC cannot be directly obtained from the mapping data table according to the expansion rate query, the SOC corresponding to the expansion rate is inferred, thereby providing data support for improving the accuracy of SOC detection.

[0098] In addition, the degree of change in the thickness of the battery electrode is different when the battery is in the charging state and the discharging state. Therefore, the present application can also obtain the mapping relationship between the expansion rate and SOC in the charging state and the discharging state according to the different charging and discharging states of the target battery, so as to further improve the accuracy of the battery SOC detection.

[0099] Figure 5 A flowchart of another battery status detection method provided in an embodiment of the present application is shown below. Figure 5 As shown, the method may also include:

[0100] S501: Obtain the charge and discharge status of a target battery.

[0101] The charge and discharge status of the target battery is obtained directly from the BMS, or according to the working data of the target battery. For example, a current sensor (such as a Hall effect current sensor) can be connected in series in the charge and discharge circuit of the target battery to obtain current information. If the current is positive, it means that the battery is in a charging state; if the current is negative, it means that the battery is in a discharging state.

[0102] S502 . According to the charge and discharge state of the target battery, a mapping relationship between the expansion rate and the SOC corresponding to the charge and discharge state is obtained.

[0103] In the process of constructing the mapping relationship between the expansion rate and SOC mentioned above, the expansion rate and SOC can be divided into two types of test data: the expansion rate and SOC in the charging state, and the expansion rate and SOC in the discharging state. According to different types of test data, the mapping relationship between the expansion rate and SOC corresponding to the charging state and the mapping relationship between the expansion rate and SOC corresponding to the discharging state are generated.

[0104] For example, the mapping relationship between the expansion rate and the SOC corresponding to the charge and discharge state may be as shown in the following Table 3:

[0105] Table 3

[0106]

[0107] Correspondingly, if the mapping relationship between the expansion rate and the SOC is represented by a functional relationship, under the same SOH, it can be represented by two functional relationships corresponding to the charge and discharge states, or two function curves corresponding to the charge and discharge states. Figure 6 A schematic diagram of another mapping relationship provided in an embodiment of the present application, such as Figure 6 As shown, under the same SOH, it includes a first function curve corresponding to the charging state and a second function curve corresponding to the discharging state.

[0108] According to the charge and discharge state of the target battery, a mapping relationship of a corresponding category is selected from the pre-stored mapping relationships of the expansion rate and the SOC to obtain a mapping relationship of the expansion rate and the SOC corresponding to the charge and discharge state. For example, if the charge and discharge state of the target battery is a charging state, a mapping relationship of the expansion rate and the SOC corresponding to the charging state is obtained; if the charge and discharge state of the target battery is a discharging state, a mapping relationship of the expansion rate and the SOC corresponding to the discharging state is obtained.

[0109] S503 . Obtain the SOC of the target battery according to the expansion rate and the mapping relationship between the expansion rate and the SOC corresponding to the charge and discharge state.

[0110] In this step, how to obtain the SOC of the target battery according to the expansion rate and the mapping relationship between the expansion rate and SOC corresponding to the charge and discharge state can be referred to the aforementioned Figure 2-Figure 4 The difference between this step and the content in the above method is that two types of mapping relationships corresponding to the charge and discharge states are divided, and other implementation contents remain unchanged and will not be repeated here.

[0111] The method provided in the embodiment of the present application obtains the charge and discharge state of the target battery, and obtains the mapping relationship between the expansion rate corresponding to the charge and discharge state and the SOC according to the charge and discharge state of the target battery. The SOC of the target battery is obtained according to the expansion rate and the mapping relationship between the expansion rate corresponding to the charge and discharge state and the SOC, so as to detect and obtain the SOC using a more accurate mapping relationship under different states according to different charge and discharge states, thereby further improving the accuracy of the battery SOC detection.

[0112] Optionally, the battery electrode sheet thickness obtained in the aforementioned step S101 may be the thickness of a specific position of the battery electrode sheet, or the thickness of M different positions on the electrode sheet of the target battery, where M is an integer greater than or equal to 2. When the obtained battery electrode sheet thickness is the thickness of M different positions on the electrode sheet of the target battery, the method of the present application may further include the following steps: Figure 7 The scheme shown.

[0113] Figure 7 A flowchart of another battery status detection method provided in an embodiment of the present application is shown below. Figure 7 As shown, the method may also include:

[0114] S701. Obtain M candidate expansion rates of a target battery according to the thicknesses of M battery electrodes.

[0115] In this step, the aforementioned method of obtaining the expansion rate of the target battery according to the battery electrode thickness can be referred to, and for each of the M battery electrode thicknesses, the corresponding expansion rate is obtained, and finally M candidate expansion rates are obtained, which will not be repeated here.

[0116] S702: Determine N target expansion rates from the M candidate expansion rates.

[0117] Wherein, N is an integer greater than or equal to 1 and less than or equal to M. Since the values ​​of the M expansion rates are different, N expansion rates that are relatively stable among the M candidate expansion rates may be selected as target expansion rates.

[0118] Optionally, based on historical test data, it is possible to determine which locations in the battery electrode have thicknesses with relatively stable expansion rates, and use candidate expansion rates corresponding to these locations as target expansion rates.

[0119] Optionally, the discreteness of the M candidate expansion ratios may be determined according to the standard deviation, variance, etc. of the M candidate expansion ratios, and the N candidate expansion ratios with smaller discreteness may be used as the target expansion ratios.

[0120] S703 . Obtain the target battery SOC according to the N target expansion rates and the mapping relationship between the expansion rate and the SOC.

[0121] In a possible implementation, N SOC values ​​may be obtained according to N target expansion rates and the mapping relationship between the expansion rate and the SOC, and then the SOC of the target battery may be obtained according to the N SOC values. For example, the mean or median of the N SOC values ​​may be used as the SOC of the target battery.

[0122] Another possible implementation manner is to obtain a first expansion rate according to N target expansion rates, and obtain the SOC of the target battery according to the first expansion rate and the mapping relationship between the expansion rate and the SOC. For example, the first expansion rate may be determined based on the average of the N target expansion rates (that is, the average is used as the first expansion rate), or the first expansion rate may be determined based on the median of the N target expansion rates (that is, the median is used as the first expansion rate), etc. After determining the first expansion rate, based on the first expansion rate and the mapping relationship between the expansion rate and the SOC, the SOC of the target battery is obtained by the method of obtaining the SOC according to the expansion rate and the mapping relationship between the expansion rate and the SOC provided in the above embodiments.

[0123] Optionally, the M battery electrode sheet thicknesses may be processed first to obtain N more representative or more stable battery electrode sheet thicknesses, and then the target battery electrode sheet thickness is determined based on the N battery electrode sheet thicknesses (for example, the average of the N battery electrode sheet thicknesses is used as the target battery electrode sheet thickness), and finally the SOC of the target battery is obtained based on the mapping relationship between the target battery electrode sheet thickness, the expansion rate and the SOC. Alternatively, the M battery electrode sheet thicknesses may be processed to obtain N more representative or more stable battery electrode sheet thicknesses, and then N target expansion rates may be obtained based on the N battery electrode sheet thicknesses, and then the SOC of the target battery may be obtained through the method of step S703.

[0124] The method provided in the embodiment of the present application collects M battery pole piece thicknesses, and obtains M candidate expansion rates of the target battery based on the M battery pole piece thicknesses. By screening the M candidate expansion rates, the candidate expansion rates corresponding to N positions with stronger representativeness or greater stability are determined, and the SOC of the target battery is determined by comprehensive analysis based on the N candidate expansion rates and the mapping relationship between the expansion rate and the SOC, thereby increasing the data volume and analysis dimension, thereby further improving the accuracy and reliability of SOC detection.

[0125] Figure 8 This is a schematic diagram of the structure of a battery status detection device provided in an embodiment of the present application. Figure 8 As shown, the battery status detection device may include: an acquisition module 11 and a processing module 12.

[0126] The acquisition module 11 is used to obtain the battery electrode thickness of the target battery and the battery health state SOH.

[0127] The processing module 12 is used to obtain the battery state SOC of the target battery according to the battery electrode thickness and the SOH.

[0128] Optionally, the processing module 12 is specifically configured to obtain the expansion rate of the target battery according to the battery electrode thickness and the SOH, and obtain the SOC of the target battery according to the expansion rate and the mapping relationship between the expansion rate and the SOC.

[0129] Optionally, the processing module 12 is specifically configured to obtain a reference thickness of a pole piece according to the SOH, and to obtain a swelling rate of the target battery according to the thickness of the pole piece of the battery and the reference thickness of the pole piece.

[0130] Optionally, the processing module 12 is specifically used to obtain a pole piece thickness coefficient corresponding to the SOH according to the SOH. According to the pole piece thickness coefficient and the reference battery pole piece thickness, the pole piece reference thickness under the SOH is determined. The pole piece thickness coefficient is determined based on the battery pole piece thickness of different SOHs under a preset SOC, and the reference battery pole piece thickness.

[0131] Optionally, the processing module 12 is specifically used to determine the reference thickness of the electrode under the current SOH according to the product of the electrode thickness coefficient and the reference battery electrode thickness.

[0132] Optionally, the processing module 12 is specifically configured to determine a difference in electrode thickness according to a difference between the battery electrode thickness and a reference electrode thickness, and to determine the expansion rate according to the difference in electrode thickness and the reference battery electrode thickness.

[0133] Optionally, the mapping relationship between the expansion rate and the SOC includes: an expansion rate interval, a first SOC corresponding to the lower limit value of the expansion rate interval, and a second SOC corresponding to the upper limit value of the expansion rate interval, and when the first SOC is less than the second SOC. The processing module 12 is specifically configured to: if the expansion rate is equal to the lower limit value, the SOC of the target battery is equal to the first SOC. If the expansion rate is equal to the upper limit value, the SOC of the target battery is equal to the second SOC. If the expansion rate is greater than the lower limit value and less than the upper limit value, the SOC of the target battery is obtained by interpolating between the first SOC and the second SOC.

[0134] Optionally, the acquisition module 11 is further used to acquire the charge and discharge state of the target battery. The processing module 12 is further used to acquire the mapping relationship between the expansion rate corresponding to the charge and discharge state and the SOC according to the charge and discharge state of the target battery. The SOC of the target battery is obtained according to the expansion rate and the mapping relationship between the expansion rate corresponding to the charge and discharge state and the SOC.

[0135] Optionally, when the battery electrode sheet thickness includes the thickness of M different positions on the electrode sheet of the target battery, and M is an integer greater than or equal to 2, the acquisition module 11 is further used to acquire M candidate expansion rates of the target battery according to the M battery electrode sheet thicknesses. The processing module 12 is further used to determine N target expansion rates from the M candidate expansion rates, and N is an integer greater than or equal to 1 and less than or equal to M. According to the N target expansion rates and the mapping relationship between the expansion rate and the SOC, the SOC of the target battery is obtained.

[0136] Optionally, the processing module 12 is specifically configured to obtain a first expansion rate according to the N target expansion rates, and obtain the SOC of the target battery according to the first expansion rate and a mapping relationship between the expansion rate and the SOC.

[0137] Optionally, the processing module 12 is specifically configured to determine the first expansion rate based on an average of the N target expansion rates.

[0138] Optionally, the reference battery electrode thickness is the battery electrode thickness of the battery when the SOH is 100% and discharged to the cut-off voltage.

[0139] The battery status detection device provided in the embodiment of the present application can execute the battery status detection method in the above method embodiment, and its implementation principle and technical effect are similar and will not be repeated here.

[0140] Fig. 9 The structure diagram of an electronic device provided in an embodiment of the present application. The electronic device is used to perform the battery status detection mentioned above, for example, it can be the electronic device with data processing function mentioned above. Fig. 9 As shown, the electronic device 900 may include: at least one processor 901 , a memory 902 , and a communication interface 903 .

[0141] The memory 902 is used to store programs. Specifically, the programs may include program codes, and the program codes include computer operation instructions.

[0142] The memory 902 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0143] The processor 901 is used to execute the computer-executable instructions stored in the memory 902 to implement the method described in the above method embodiment. The processor 901 may be a CPU, or an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0144] The processor 901 can communicate and interact with external devices through the communication interface 903, and the external device can be, for example, the aforementioned BMS. In a specific implementation, if the communication interface 903, the memory 902, and the processor 901 are implemented independently, the communication interface 903, the memory 902, and the processor 901 can be interconnected through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc., but it does not mean that there is only one bus or one type of bus.

[0145] Optionally, in a specific implementation, if the communication interface 903, the memory 902 and the processor 901 are integrated on a chip, the communication interface 903, the memory 902 and the processor 901 can communicate through an internal interface.

[0146] The present application also provides a computer program product, including a computer program, which implements the above method when executed by a processor.

[0147] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When a processor executes the computer-executable instructions, the above method is implemented.

[0148] The above-mentioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. The readable storage medium can be any available medium that can be accessed by a general or special-purpose computer.

[0149] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (Application Specific Integrated Circuits, referred to as: ASIC). Of course, the processor and the readable storage medium can also exist in the device as discrete components.

[0150] The division of units is only a logical function division, and there may be other divisions in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, device or unit, which can be electrical, mechanical or other forms.

[0151] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0152] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0153] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0154] Those skilled in the art can understand that all or part of the steps of implementing the above-mentioned method embodiments can be completed by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes: ROM, RAM, disk or optical disk and other media that can store program codes.

[0155] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A battery status detection method, characterized in that: include: Obtain the battery electrode thickness of the target battery and the battery health status SOH; The battery state SOC of the target battery is obtained according to the battery electrode thickness and the SOH.

2. The method according to claim 1, characterized in that The obtaining the battery state SOC of the target battery according to the battery electrode thickness and the SOH includes: Obtaining the expansion rate of the target battery according to the battery electrode thickness and the SOH; The SOC of the target battery is obtained according to the expansion rate and a mapping relationship between the expansion rate and the SOC.

3. The method according to claim 2, characterized in that The step of obtaining the expansion rate of the target battery according to the battery electrode thickness and the SOH includes: According to the SOH, obtaining a reference thickness of the electrode; The expansion rate of the target battery is obtained according to the battery electrode thickness and the electrode reference thickness.

4. The method according to claim 3, characterized in that The step of obtaining a reference thickness of a pole piece according to the SOH comprises: According to the SOH, obtaining a pole piece thickness coefficient corresponding to the SOH, wherein the pole piece thickness coefficient is based on the battery pole piece thickness at different SOHs under a preset SOC, and is determined with reference to the battery pole piece thickness; The reference thickness of the electrode under the SOH is determined according to the electrode thickness coefficient and the reference battery electrode thickness.

5. The method according to claim 4, characterized in that Determining the reference thickness of the electrode under the current SOH according to the electrode thickness coefficient and the reference battery electrode thickness includes: The reference thickness of the electrode under the current SOH is determined according to the product of the electrode thickness coefficient and the reference battery electrode thickness.

6. The method according to claim 5, characterized in that The step of obtaining the expansion rate of the target battery according to the battery electrode sheet thickness and the electrode sheet reference thickness includes: Determining a pole piece thickness difference according to a difference between the battery pole piece thickness and the pole piece reference thickness; The expansion rate is determined based on the difference in electrode thickness and the reference battery electrode thickness.

7. The method according to claim 6, characterized in that The mapping relationship between the expansion rate and the SOC includes: an expansion rate interval, a first SOC corresponding to a lower limit value of the expansion rate interval, and a second SOC corresponding to an upper limit value of the expansion rate interval, wherein the first SOC is less than the second SOC; The obtaining the SOC of the target battery according to the expansion rate and the mapping relationship between the expansion rate and the SOC includes: If the expansion rate is equal to the lower limit value, the SOC of the target battery is equal to the first SOC; If the expansion rate is equal to the upper limit value, the SOC of the target battery is equal to the second SOC; If the expansion rate is greater than the lower limit value and less than the upper limit value, the SOC of the target battery is obtained by interpolating between the first SOC and the second SOC.

8. The method according to claim 2, characterized in that: The method further comprises: Acquiring the charge and discharge status of the target battery; The obtaining the SOC of the target battery according to the expansion rate and the mapping relationship between the expansion rate and the SOC includes: According to the charge and discharge state of the target battery, obtaining a mapping relationship between the expansion rate and the SOC corresponding to the charge and discharge state; The SOC of the target battery is obtained according to the expansion rate and the mapping relationship between the expansion rate and the SOC corresponding to the charge and discharge state.

9. The method according to any one of claims 2 to 8, characterized in that: The battery electrode sheet thickness includes the thickness of M different positions on the electrode sheet of the target battery, where M is an integer greater than or equal to 2; the method further includes: According to the thicknesses of the M battery pole pieces, obtaining M candidate expansion rates of the target battery; Determine N target expansion ratios from the M candidate expansion ratios, where N is an integer greater than or equal to 1 and less than or equal to M; The target battery SOC is obtained according to the N target expansion rates and a mapping relationship between the expansion rate and the SOC.

10. The method according to claim 9, characterized in that The step of obtaining the SOC of the target battery according to the N target expansion rates and the mapping relationship between the expansion rate and the SOC includes: Acquire a first expansion rate according to the N target expansion rates; The SOC of the target battery is obtained according to the first expansion rate and a mapping relationship between the expansion rate and the SOC.

11. The method according to claim 10, characterized in that The obtaining a first expansion rate according to the N target expansion rates includes: The first expansion ratio is determined based on an average of the N target expansion ratios.

12. The method according to claim 4 or 5, characterized in that: The reference battery electrode thickness is the battery electrode thickness of the battery when the SOH is 100% and discharged to the cut-off voltage.

13. A battery status detection device, characterized in that: include: An acquisition module is used to obtain the battery electrode thickness of the target battery and the battery health status SOH; A processing module is used to obtain the battery state SOC of the target battery according to the battery electrode thickness and the SOH.

14. An electronic device, characterized in that: include: Memory, processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory, so that the processor performs the method according to any one of claims 1 to 12.

15. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 12 when executed by a processor.

16. A computer program product, characterized in that The invention comprises a computer program, which implements the method according to any one of claims 1 to 12 when being executed by a processor.

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