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

Abstract

This application provides a battery state detection method, apparatus, device, storage medium, and program product. The method includes: obtaining the battery electrode thickness of a target battery and the battery state of health (SOH); and obtaining the battery state of charge (SOC) of the target battery based on the battery electrode thickness and the SOH. The method of this application can improve the accuracy of SOC detection.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery state detection method, apparatus, device, storage medium, and program product. Background Technology

[0002] With increasing emphasis on environmental protection and low carbon emissions, the development of new energy vehicles has accelerated significantly. The integration of automotive technologies with energy, transportation, and information communication technologies is accelerating, with electrification, connectivity, and intelligence becoming the development trend of the automotive industry. New technologies for new energy vehicles are emerging rapidly, such as: Application No. CN202410658157.7, Publication No. CN118238797B, entitled "Intelligent Energy Management System, Control Method, and Related Equipment for New Energy Vehicles"; Application No. CN202410672579.X, Publication No. CN118597091A, entitled "Intelligent Energy Management Method, System, and Related Equipment for New Energy Vehicles"; and Application No. 202410669449.0, entitled "Intelligent Energy Management System, Control Method, and Related Equipment for New Energy Vehicles." All of these applications describe hybrid technology primarily based on electricity, possessing multiple advantages such as speed, fuel efficiency, quietness, smoothness, and environmental friendliness. For example: Application number CN202211678720.4, publication number CN117382629B, entitled "Power Control Method, Device, Medium, Vehicle Controller, and Vehicle for a Vehicle"; Application number CN202311164098.X, publication number CN116890770B, entitled "Vehicle Control System, Method, and Vehicle"; Application number CN202311170393.6, publication number CN117533292B, entitled "Vehicle Control System, Control Method, Controller, and Vehicle". All of these applications describe a new energy power system with four wheel-side motors independently driven as its core, which greatly improves the safety and power performance of new energy vehicles.

[0003] For new energy vehicles, power is primarily provided by batteries. For batteries, the State of Charge (SOC) is a crucial indicator, essentially reflecting the amount of remaining charge. Accurately knowing the battery's SOC affects its overall performance, safety, and lifespan. The power performance and fuel economy of new energy vehicles are closely related to the battery's state of charge. Accurately estimating SOC allows for more precise application of the State of Power (SOP), thereby effectively improving vehicle fuel economy and battery lifespan. However, current methods for detecting SOC using open circuit voltage (OCV)-SOC lookup tables and ampere-hour integration methods suffer from low accuracy.

[0004] Therefore, improving the accuracy of SOC detection is an urgent problem to be solved. Summary of the Invention

[0005] This application provides battery state detection methods, apparatus, devices, storage media, and program products to improve the accuracy of SOC detection.

[0006] In a first aspect, embodiments of this application provide a battery state detection method, including:

[0007] Obtain the thickness of the battery electrode sheets of the target battery, and the state of health (SOH) of the battery;

[0008] The state of charge (SOC) of the target battery is obtained based on the thickness of the battery electrode and the state of charge (SOH).

[0009] Secondly, embodiments of this application provide a battery state detection device, comprising:

[0010] The acquisition module is used to acquire the thickness of the battery electrode sheets of the target battery, as well as the state of health (SOH) of the battery.

[0011] The processing module is used to obtain the state of charge (SOC) of the target battery based on the thickness of the battery electrode and the SOH.

[0012] Thirdly, embodiments of this application provide an electronic device, including: a memory and a processor;

[0013] The memory stores computer-executed instructions;

[0014] The processor executes computer execution instructions stored in the memory, causing the processor to perform the first aspect and / or various possible implementations of the first aspect as described above.

[0015] Fourthly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the first aspect and / or various possible implementations of the first aspect.

[0016] Fifthly, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the first aspect and / or various possible implementations of the first aspect.

[0017] The battery state detection method, apparatus, device, storage medium, and program product provided in this 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 accurately detect the SOC during battery use and reduce the problem of poor SOC detection accuracy caused by factors such as current acquisition deviation and initial SOC deviation, thereby improving the accuracy of battery SOC detection. Attached Figure Description

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

[0019] Figure 1 A schematic flowchart illustrating a battery state detection method provided in an embodiment of this application;

[0020] Figure 2 A flowchart illustrating another battery state detection method provided in an embodiment of this application;

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

[0022] Figure 4 A schematic flowchart illustrating another battery state detection method provided in this application embodiment;

[0023] Figure 5 A schematic flowchart illustrating another battery state detection method provided in an embodiment of this application;

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

[0025] Figure 7 A schematic flowchart illustrating another battery state detection method provided in an embodiment of this application;

[0026] Figure 8 This is a schematic diagram of the structure of a battery state detection device provided in an embodiment of this application;

[0027] Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.

[0028] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0029] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0030] First, let's introduce the technical terms used in the embodiments of this application:

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

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

[0033] Currently, the SOC of a battery is mainly detected by the OCV-SOC lookup table method and the ampere-hour integration method.

[0034] The open-circuit voltage lookup table method is based on a specific relationship between OCV and SOC, using OCV to evaluate SOC. This method avoids the problems of the ampere-hour integration method. However, polarization occurs during battery charging and discharging, and OCV needs to wait for the battery to rest for a period of time to remove polarization before an accurate open-circuit voltage value can be determined. Therefore, it cannot be used to evaluate SOC in real time during battery use (e.g., during the driving of an electric vehicle). In addition, lithium iron phosphate batteries have a voltage plateau region, meaning that the characteristic curves of OCV and SOC are not obvious, and the open-circuit voltage lookup table method cannot be used to obtain SOC in this region.

[0035] The ampere-hour integration method obtains the charge / discharge capacity by integrating the current over time, and calculates the current SOC based on the accumulated charge / discharge capacity from the initial SOC. However, the ampere-hour integration method requires a high degree of accuracy in the initial SOC value. If the initial SOC value has an error, the SOC value obtained by subsequent integration will deviate. In this case, the charge / discharge power value based on the incorrect SOC may exceed the battery's operating range, thereby affecting battery life and potentially causing battery safety issues. Furthermore, if the current sensor is affected by environmental factors, zero-point drift, or unknown factors, resulting in inaccurate current sampling, errors will accumulate during time integration, leading to a significant deviation in the obtained SOC.

[0036] During the research process, the applicant discovered that the thickness of the battery electrode changes synchronously with the battery's SOC and SOH, and this change is relatively stable. In view of this, this application provides a battery state detection method. By obtaining the thickness of the battery electrode and the SOH of the target battery, the SOC of the target battery is obtained based on the thickness of the battery electrode and the SOH. Compared with the prior art, this method can accurately detect the SOC during battery use and also reduces the problem of poor SOC detection accuracy caused by factors such as current acquisition deviation and initial SOC deviation, thereby improving the accuracy of battery SOC detection.

[0037] The battery state detection method provided in this application can be executed by a terminal device with data processing capabilities, or by the processing chip of that terminal device, or by software or program code implementing the data processing method. When the executing entity is a terminal device with data processing capabilities, the terminal device can be, for example, a computing device such as a computer or mobile phone with computing capabilities. The computing device can be equipped with software or program code that runs the battery state detection method, and the battery's SOC can be detected through the software or program code.

[0038] The technical solution of this application and how it solves the above-mentioned technical problems will be described in detail below through specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described below with reference to the accompanying drawings.

[0039] Figure 1 This is a schematic flowchart illustrating a battery state detection method provided in an embodiment of this application. Figure 1 As shown, the method includes:

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

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

[0042] The thickness of the battery electrode can be obtained in real time by a thickness acquisition device pre-installed inside the battery cell. This device can be, for example, a resistance strain gauge or an optical sensor (which acquires the thickness of the battery electrode through optical measurement). Alternatively, the thickness of the battery electrode can be obtained through a capacitance measurement method, for example, by using the battery electrode as one of the plates of a capacitor and determining the thickness of the battery electrode based on the change in the capacitance value of the capacitor.

[0043] The State of Health (SOH) of the target battery can be obtained from the Battery Management System (BMS) or based on battery operating data using a deep learning model to predict SOH. For example, the SOH of the target battery can be obtained in real time during the charging and discharging process, based on preset time intervals, or based on a preset number of charge-discharge cycles, as long as it represents the current SOH of the target battery.

[0044] S102. Based on the thickness of the battery electrode and the SOH, obtain the SOC of the target battery.

[0045] In this step, the SOC of the target battery can be obtained based on the battery electrode thickness and SOH. Alternatively, the SOC of the target battery can be obtained based on the changes in the battery electrode thickness (e.g., the expansion rate, rate of change, etc. of the battery electrode thickness) and then based on the changes in the battery electrode thickness and SOH.

[0046] One possible implementation is to obtain the SOC of the target battery based on the battery electrode thickness, SOH, and a pre-built mapping relationship. This mapping relationship, which is a relationship between battery electrode thickness, SOH, and SOC, can be, for example, a mapping data table or function curve that includes the mapping relationship between battery electrode thickness, SOH, and SOC. Once the battery electrode thickness and SOH of the target battery are obtained, the SOC can be obtained using the pre-built mapping relationship.

[0047] This mapping relationship can be obtained in advance by measuring the thickness of the battery electrode sheets of the target battery or a battery of the same model 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) can be set, and the corresponding battery electrode sheet thicknesses can be measured to obtain this mapping relationship.

[0048] Another possible implementation is to obtain the SOC of the target battery through a pre-trained machine learning model. That is, the battery electrode thickness and SOH are used as model inputs, and the pre-trained machine learning model outputs the predicted SOC. This machine learning model can be, for example, a neural network model, a decision tree model, a vector machine model, etc., and this application is not limited to this. Specifically, the battery electrode thickness of the target battery or batteries of the same model can be obtained under different SOC and SOH conditions. This data can be used as training data to train the machine learning model to obtain a predictive model that can predict the SOC based on the battery electrode thickness and SOH.

[0049] The method provided in this application obtains the thickness of the battery electrode and the state of harmonics (SOH) of the target battery, and obtains the state of charge (SOC) of the target battery based on the thickness of the battery electrode and the SOH. Compared with the prior art, it can accurately detect the SOC during battery use and reduce the problem of poor SOC detection accuracy caused by factors such as current acquisition deviation and initial SOC deviation, thereby improving the accuracy of SOC detection of the battery.

[0050] The following section will take obtaining the expansion rate of the battery electrode through the thickness of the battery electrode as an example to explain in detail how the state of the battery (SOC) of the target battery is obtained based on the thickness of the battery electrode and the state of charge (SOH) in the aforementioned step S102. Figure 2 This is a flowchart illustrating another battery state detection method provided in an embodiment of this application. Figure 2 As shown, the aforementioned step S102 may specifically include:

[0051] S201. Based on the thickness of the battery electrode and the state of oxygen (SOH), obtain the expansion rate of the target battery.

[0052] The expansion rate of the target battery is essentially the expansion rate of the current battery electrode thickness based on a certain reference thickness (also known as the electrode reference thickness). This 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] During the charging and discharging process of the target battery, the battery electrodes undergo expansion and deformation, resulting in varying electrode thicknesses at different states of charge (SOC) and states of equilibrium (SOH). Therefore, the expansion rate of the electrode thickness based on a reference electrode thickness also differs under different SOH conditions. Based on this, a correlation can be established between electrode thickness, SOH, and the expansion rate of the target battery.

[0054] One possible approach is to establish different correlations between battery electrode thickness and the expansion rate of the target battery for different State of Hypothesis (SOH). For example, correlation 1 could be used when the SOH is 100%, and correlation 2 could be used when the SOH is 50%. Based on the correlations corresponding to the SOH and the battery electrode thickness, the expansion rate of the target battery can be obtained.

[0055] Another possible implementation involves using different reference electrode thicknesses for different state of equilibrium (SOH). The expansion rate of the battery electrode thickness based on the reference electrode thickness is calculated using the reference electrode thickness corresponding to the SOH and the battery electrode thickness. This implementation can be achieved through the following sub-steps:

[0056] S2011. Obtain the reference thickness of the electrode based on the SOH.

[0057] One possible implementation is to obtain the electrode reference thickness by pre-stored correlation between SOH and electrode reference thickness, as well as the SOH value. For example, when SOH is 100%, the electrode reference thickness is 1 mm, and when SOH is 10%, the electrode reference thickness is 0.2 mm, etc.

[0058] Another possible implementation is to obtain the electrode reference thickness based on the electrode thickness coefficient corresponding to different SOHs and the 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).

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

[0060] Specifically, the electrode thickness difference can be determined based on the difference between the battery electrode thickness and the reference electrode thickness. Then, the expansion rate is determined based on the electrode thickness difference and the reference electrode thickness. In this case, the expansion rate of the target battery characterizes the expansion ratio of the battery electrode thickness of the target battery relative to the reference electrode thickness. For example, the expansion rate of the target battery can be shown in the following formula (1):

[0061] (1)

[0062] in, The expansion rate of the target battery. Given the current electrode thickness of the target battery, This is the reference thickness for the electrode.

[0063] S202. Based on the expansion rate and the mapping relationship between the expansion rate and SOC, obtain the SOC of the target battery.

[0064] Based on the expansion rate, the SOC corresponding to the expansion rate is determined in the mapping relationship between expansion rate and SOC, and this SOC is taken as the SOC of the target battery.

[0065] For example, the mapping relationship between expansion rate and 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 merely an example of a mapping relationship for ease of understanding and is not a limitation. This mapping relationship can be configured with varying data precision according to actual needs; for example, it can be subdivided into one expansion rate value for every 1% SOC, or one expansion rate value for every 0.1% SOC, etc. This application does not impose any limitations on this.

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

[0070] For example, Figure 3 This is a schematic diagram illustrating a mapping relationship provided in an embodiment of this application. For example... Figure 3 As shown, this mapping relationship is a functional relationship between the expansion rate of the battery electrode thickness and the State of Charge (SOC). This functional relationship can be obtained, for example, by fitting multiple sets of test data under a certain State of Health (SOH), where the test data includes both the SOC and the expansion rate of the battery electrode thickness. Based on the SOH of the target battery, the functional relationship corresponding to the SOH is determined. Substituting the expansion rate of the battery electrode thickness into this functional relationship yields the SOC corresponding to the expansion rate of the battery electrode thickness and the SOH.

[0071] The method provided in this application obtains the expansion rate of the target battery by measuring the thickness of the battery electrode and the state of oxygen (SOH). Based on the expansion rate and the mapping relationship between the expansion rate and the state of oxygen (SOC), the SOC of the target battery is obtained. This method has fewer influencing factors on the data required for SOC detection and has higher accuracy, thereby improving the accuracy of SOC detection for batteries.

[0072] Below, taking different SOH values ​​corresponding to different electrode thickness coefficients as an example, we will give a detailed introduction to how to obtain the electrode reference thickness based on SOH in the aforementioned step S2011. Figure 4 This is a flowchart illustrating another battery state detection method provided in an embodiment of this application. Figure 4 As shown, the aforementioned step S2011 may specifically include:

[0073] S401. Based on SOH, obtain the electrode thickness coefficient corresponding to SOH.

[0074] The electrode thickness coefficient is determined based on the battery electrode thickness at different SOHs under a preset SOC, and also by a reference battery electrode thickness. For example, batteries of the same model as the target battery can be tested beforehand to obtain the battery electrode thickness at different SOHs and the preset SOC. This preset SOC can be set according to actual needs, for example, it can be set to 100%, 20%, 0%, etc. The SOC corresponding to the reference battery electrode thickness is also a preset SOC.

[0075] Taking the reference battery electrode thickness as an example, where the reference battery's SOH is 100% and the reference battery is discharged to the cutoff voltage, the electrode thickness is described below. Here, the reference battery being discharged to the cutoff voltage indicates that the preset SOC is 0%. Correspondingly, the formula for calculating the electrode thickness coefficient is as shown in formula (2) below:

[0076] (2)

[0077] in, The electrode thickness coefficient is... To preset the battery electrode thickness for different SOHs at SOC, The reference battery electrode thickness is the battery electrode thickness when SOH is 100% and the battery electrode thickness when discharged to the cutoff voltage.

[0078] S402. Determine the reference electrode thickness under SOH based on the electrode thickness coefficient and the reference battery electrode thickness.

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

[0080] Continuing with the example of formula (2), formula (2) can be rearranged to obtain formula (3), which is equivalent to formula (2):

[0081] (3)

[0082] In this case, the SOH of the target battery can be substituted into formula (3). This allows us to obtain the reference electrode thickness at the state of harmonic equilibrium (SOH) of the target battery. For example, assuming the SOH of the target battery is 50%, the electrode thickness coefficient corresponding to 50% SOH can be obtained. And the thickness of the reference battery electrode Obtain the reference thickness of the electrode. (i.e., in the aforementioned formula (1)) ).

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

[0084] (4)

[0085] That is, the expansion rate of the target battery can be calculated simply by using the electrode thickness coefficient corresponding to SOH and the reference battery electrode thickness.

[0086] The method provided in this application calculates the expansion rate of the target battery electrode thickness relative to the reference electrode thickness by obtaining the electrode thickness coefficient corresponding to the state of equilibrium (SOH) and the reference battery electrode thickness. This eliminates the influence of different SOH values ​​causing different variations in battery electrode thickness. Thus, the expansion rate of the target battery can be obtained solely based on the relationship between the electrode thickness coefficient and SOH obtained through pre-testing, and the reference battery electrode thickness. Furthermore, the SOC of the target battery is determined based on the expansion rate and the mapping relationship between the expansion rate and SOC, thereby improving the efficiency and accuracy of battery SOC detection.

[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 precision in the mapping relationship is lower than the actual data precision, the corresponding SOC cannot be directly obtained from the mapping data table based on the expansion rate. In this case, the SOC corresponding to the expansion rate can be determined by interpolation.

[0088] In this implementation, the mapping relationship between expansion rate and SOC includes: expansion rate range, first SOC corresponding to the lower limit of expansion rate range, and second SOC corresponding to the upper limit of expansion rate range, wherein 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 expansion rate and SOC can be shown in Table 2 below:

[0090] Table 2

[0091]

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

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

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

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

[0096] Optionally, if the mapping relationship between expansion rate and SOC is stored in a mapping data table, and the precision of the data in the mapping relationship is lower than the precision of the actual data, it is not possible to directly retrieve the corresponding SOC from the mapping data table based on the expansion rate. Alternatively, the mapping data table can be fitted with a corresponding function curve, and the SOC corresponding to the expansion rate can be determined based on this function curve. For example, the mapping data table can be fitted with a corresponding function curve to obtain the function expression or graph of the curve. Based on the function expression or graph, the expansion rate of the target battery can be substituted to obtain the SOC corresponding to the expansion rate of the target battery.

[0097] The method provided in this application embodiment, through interpolation or curve fitting, calculates the SOC corresponding to the expansion rate when the mapping relationship between the expansion rate and SOC is stored in a mapping data table and the data precision in the mapping relationship is lower than the actual data precision, making it impossible to directly query the corresponding SOC from the mapping data table based on the expansion rate. This provides data support for improving the accuracy of SOC detection.

[0098] Furthermore, 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, this application can also obtain the mapping relationship between the expansion rate and the state of charge (SOC) under the charging state and the discharging state of the target battery, respectively, so as to further improve the accuracy of the battery's SOC detection.

[0099] Figure 5 This is a schematic flowchart illustrating another battery state detection method provided in an embodiment of this application. Figure 5 As shown, this method may also include:

[0100] S501. Obtain the charge / discharge status of the target battery.

[0101] The charge / discharge state of the target battery can be obtained directly from the BMS or based on the battery's operating data. For example, a current sensor (e.g., a Hall effect current sensor) can be connected in series in the battery's charge / discharge circuit to acquire current information. A positive current value indicates that the battery is charging; a negative current value indicates that the battery is discharging.

[0102] S502. Based on the charge / discharge state of the target battery, obtain the mapping relationship between the expansion rate and SOC corresponding to the charge / discharge state.

[0103] In the aforementioned process of constructing the mapping relationship between expansion rate and SOC, the expansion rate and SOC can be divided into two categories of test data: expansion rate and SOC under charging conditions, and expansion rate and SOC under discharging conditions. Based on the different categories of test data, mapping relationships between expansion rate and SOC corresponding to the charging state and the discharging state are generated.

[0104] For example, the mapping relationship between the expansion rate corresponding to the state of charge and discharge and the state of charge (SOC) can be shown in Table 3 below:

[0105] Table 3

[0106]

[0107] Correspondingly, if the mapping relationship between the expansion rate and the state of charge (SOC) is expressed by a functional relationship, then under the same state of charge (SOH), it can be represented by two functional relationships corresponding to the charge and discharge states, or by two functional curves corresponding to the charge and discharge states. Figure 6 A schematic diagram illustrating another mapping relationship provided in the embodiments of this application, such as... Figure 6 As shown, under the same SOH, there are first function curves corresponding to the charging state and second function curves corresponding to the discharging state.

[0108] Based on the target battery's state of charge / discharge, a corresponding mapping relationship is selected from the pre-stored mapping relationship between expansion rate and SOC to obtain the mapping relationship between expansion rate and SOC corresponding to the charge / discharge state. For example, if the target battery's state of charge is charging, the mapping relationship between expansion rate and SOC corresponding to the charging state is obtained; if the target battery's state of charge / discharge is discharging, the mapping relationship between expansion rate and SOC corresponding to the discharging state is obtained.

[0109] S503. Based on the expansion rate and the mapping relationship between the expansion rate and SOC corresponding to the charge / discharge state, obtain the SOC of the target battery.

[0110] In this step, the specific method for obtaining the target battery's SOC based on the expansion rate and the mapping relationship between the expansion rate and SOC corresponding to the charge / discharge state can be referred to the aforementioned section. Figures 2-4 The content in this step differs from that in the aforementioned method only in that it divides the mapping relationship between the charging and discharging states into two categories. The other implementation content remains unchanged and will not be elaborated here.

[0111] The method provided in this application obtains the charge / discharge state of the target battery and, based on the charge / discharge state, obtains the mapping relationship between the expansion rate and the State of Charge (SOC) corresponding to the charge / discharge state. Based on the expansion rate and the mapping relationship between the expansion rate and SOC corresponding to the charge / discharge state, the SOC of the target battery is obtained. This allows for the detection and acquisition of SOC using a more accurate mapping relationship under different charge / discharge states, thereby further improving the accuracy of battery SOC detection.

[0112] Optionally, obtaining the battery electrode thickness in step S101 can be either obtaining the thickness at a specific location on the battery electrode or obtaining the thickness at M different locations on the electrode of the target battery, where M is an integer greater than or equal to 2. When the obtained battery electrode thickness is the thickness at M different locations on the electrode of the target battery, the method of this application may further include the following: Figure 7 The scheme shown.

[0113] Figure 7 This is a schematic flowchart illustrating another battery state detection method provided in an embodiment of this application. Figure 7 As shown, this method may also include:

[0114] S701. Based on the thickness of M battery electrodes, obtain M candidate expansion rates of the target battery.

[0115] In this step, we can refer to the aforementioned method of obtaining the expansion rate of the target battery based on the thickness of the battery electrode. For each of the M battery electrode thicknesses, we can obtain the corresponding expansion rate, and finally obtain M candidate expansion rates. This will not be elaborated here.

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

[0117] Where 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, the N most stable expansion rates among the M candidate expansion rates can be selected as the target expansion rates.

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

[0119] Optionally, the dispersion of the M candidate expansion rates can be determined based on the standard deviation, variance, etc., and the N candidate expansion rates with smaller dispersion can be used as the target expansion rate.

[0120] S703. Based on N target expansion rates and the mapping relationship between expansion rate and SOC, obtain the SOC of the target battery.

[0121] One possible implementation is to obtain N SOC values ​​based on N target expansion rates and the mapping relationship between expansion rate and SOC, and then obtain the SOC of the target battery based on these N SOC values. For example, the mean or median of the N SOC values ​​can be used as the SOC of the target battery.

[0122] Another possible implementation is to obtain a first expansion rate based on N target expansion rates, and then obtain the SOC of the target battery based on the first expansion rate and the mapping relationship between expansion rate and SOC. For example, the first expansion rate can be determined based on the average of the N target expansion rates (i.e., the average is used as the first expansion rate), or it can be determined based on the median of the N target expansion rates (i.e., the median is used as the first expansion rate), etc. After determining the first expansion rate, the SOC of the target battery is obtained based on the first expansion rate and the mapping relationship between expansion rate and SOC, using the method of obtaining SOC based on expansion rate and the mapping relationship between expansion rate and SOC provided in the aforementioned embodiments.

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

[0124] The method provided in this application collects the thickness of M battery electrodes and obtains M candidate expansion rates of the target battery based on these M electrode thicknesses. By screening the M candidate expansion rates, N candidate expansion rates corresponding to locations with stronger representativeness or greater stability are determined. Using these N candidate expansion rates, along with the mapping relationship between expansion rate and SOC, the SOC of the target battery is comprehensively analyzed and determined. This increases the amount of data and the analytical dimensions, thereby further improving the accuracy and reliability of SOC detection.

[0125] Figure 8 This is a schematic diagram of a battery state detection device provided in an embodiment of this 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 acquire the thickness of the battery electrode of the target battery, as well as the state of health (SOH) of the battery.

[0127] The processing module 12 is used to obtain the state of charge (SOC) of the target battery based on the thickness of the battery electrode and the SOH.

[0128] Optionally, the processing module 12 is specifically used to obtain the expansion rate of the target battery based on the thickness of the battery electrode and the SOH. Based on the expansion rate and the mapping relationship between the expansion rate and SOC, the SOC of the target battery is obtained.

[0129] Optionally, the processing module 12 is specifically used to obtain the reference thickness of the electrode based on the SOH. Based on the battery electrode thickness and the reference thickness, the expansion rate of the target battery is obtained.

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

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

[0132] Optionally, the processing module 12 is specifically used to determine the electrode thickness difference based on the difference between the battery electrode thickness and the reference electrode thickness. Based on the electrode thickness difference and the reference battery electrode thickness, the expansion rate is determined.

[0133] Optionally, the mapping relationship between the expansion rate and SOC includes: an expansion rate range, a first SOC corresponding to the lower limit of the expansion rate range, and a second SOC corresponding to the upper limit of the expansion rate range, wherein the first SOC is less than the second SOC. The processing module 12 is specifically configured to: if the expansion rate equals the lower limit, then the SOC of the target battery is equal to the first SOC; if the expansion rate equals the upper limit, then the SOC of the target battery is equal to the second SOC; if the expansion rate is greater than the lower limit and less than the upper limit, then the SOC of the target battery is obtained by interpolation between the first SOC and the second SOC.

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

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

[0136] Optionally, the processing module 12 is specifically used to obtain a first expansion rate based on the N target expansion rates. 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.

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

[0138] Optionally, the reference battery electrode thickness is the battery electrode thickness of a battery with a state of 100% salinity (SOH) and discharged to the cutoff voltage.

[0139] The battery state detection device provided in this application embodiment can execute the battery state detection method in the above method embodiment. Its implementation principle and technical effect are similar, and will not be described again here.

[0140] Figure 9 This is a schematic diagram of an electronic device provided in an embodiment of this application. The electronic device is used to perform the aforementioned battery state detection, and may be, for example, the aforementioned electronic device with data processing capabilities. Figure 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 program may include program code, which includes computer operation instructions.

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

[0143] The processor 901 is used to execute computer execution instructions stored in the memory 902 to implement the method described in the foregoing method embodiments. The processor 901 may be a CPU, an Application Specific Integrated Circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application.

[0144] The processor 901 can communicate and interact with external devices through the communication interface 903. These external devices can be, for example, the aforementioned BMS (Business Management System). In specific implementations, if the communication interface 903, memory 902, and processor 901 are implemented independently, they can be interconnected via a bus to complete communication. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc., but this does not imply that there is only one bus or one type of bus.

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

[0146] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0147] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-described method.

[0148] The aforementioned 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 storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0149] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from 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 reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0150] The division of units is merely a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

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

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

[0153] If a function is implemented as 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 this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0154] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0155] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A battery state detection method, characterized in that, include: Obtain the thickness of the target battery electrode, the state of health (SOH) of the battery, and the state of charge / discharge. Based on the SOH, obtain the reference thickness of the electrode; The expansion rate of the target battery is obtained based on the thickness of the battery electrode and the reference thickness of the electrode. Based on the charge / discharge state, obtain the mapping relationship between the expansion rate and SOC corresponding to the charge / discharge state; The SOC of the target battery is obtained based on the expansion rate and the mapping relationship between the expansion rate and SOC corresponding to the charge / discharge state.

2. The method according to claim 1, characterized in that, The step of obtaining the electrode reference thickness based on the SOH includes: Based on the SOH, the electrode thickness coefficient corresponding to the SOH is obtained. The electrode thickness coefficient is determined based on the battery electrode thickness at different SOHs under a preset SOC, and with reference to the battery electrode thickness. The reference electrode thickness under SOH is determined based on the electrode thickness coefficient and the reference battery electrode thickness.

3. The method according to claim 2, characterized in that, The step of determining the reference electrode thickness under the current state of equilibrium (SOH) based on the electrode thickness coefficient and the reference battery electrode thickness includes: The reference electrode thickness under the current state of equilibrium (SOH) is determined by the product of the electrode thickness coefficient and the reference battery electrode thickness.

4. The method according to claim 3, characterized in that, The step of obtaining the expansion rate of the target battery based on the battery electrode thickness and the reference electrode thickness includes: The electrode thickness difference is determined based on the difference between the battery electrode thickness and the electrode reference thickness. The expansion rate is determined based on the difference in electrode thickness and the thickness of the reference battery electrode.

5. The method according to claim 4, characterized in that, The mapping relationship between the expansion rate and the SOC includes: an expansion rate range, a first SOC corresponding to the lower limit of the expansion rate range, and a second SOC corresponding to the upper limit of the expansion rate range, wherein the first SOC is less than the second SOC. The step of obtaining the SOC of the target battery based on the expansion rate and the mapping relationship between the expansion rate and SOC includes: If the expansion rate is equal to the lower limit value, then the SOC of the target battery is equal to the first SOC; If the expansion rate is equal to the upper limit value, then the SOC of the target battery is equal to the second SOC; 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 interpolation between the first SOC and the second SOC.

6. The method according to any one of claims 1-5, characterized in that, The thickness of the battery electrode includes the thickness at M different locations on the electrode of the target battery, where M is an integer greater than or equal to 2; the method further includes: Based on the thicknesses of the M battery electrodes, obtain the M candidate expansion rates of the target battery; N target expansion rates are determined from the M candidate expansion rates, where N is an integer greater than or equal to 1 and less than or equal to M; The SOC of the target battery is obtained based on the N target expansion rates and the mapping relationship between expansion rate and SOC.

7. The method according to claim 6, characterized in that, The step of obtaining the SOC of the target battery based on the N target expansion rates and the mapping relationship between expansion rate and SOC includes: Based on the N target expansion rates, the first expansion rate is obtained; The SOC of the target battery is obtained based on the first expansion rate and the mapping relationship between the expansion rate and SOC.

8. The method according to claim 7, characterized in that, The step of obtaining the first expansion rate based on the N target expansion rates includes: The first expansion rate is determined based on the average of the N target expansion rates.

9. The method according to claim 2 or 3, characterized in that, The reference battery electrode thickness is the battery electrode thickness of the battery when the SOH is 100% and the battery is discharged to the cutoff voltage.

10. A battery state detection device, characterized in that, include: The acquisition module is used to acquire the thickness of the battery electrode, the state of health (SOH) of the battery, and the charge / discharge status of the target battery. The processing module is used to obtain the reference thickness of the electrode sheet based on the SOH; and to obtain the expansion rate of the target battery based on the battery electrode sheet thickness and the reference thickness of the electrode sheet. Based on the charge / discharge state, obtain the mapping relationship between the expansion rate and SOC corresponding to the charge / discharge state; based on the expansion rate and the mapping relationship between the expansion rate and SOC corresponding to the charge / discharge state, obtain the SOC of the target battery.

11. An electronic device, characterized in that, include: Memory, processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory, causing the processor to perform the method as described in any one of claims 1-9.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any one of claims 1-9.

13. A computer program product, characterized in that, Includes a computer program that, when executed by a processor, implements the method of any one of claims 1-9.

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