Battery swelling force determination method, electronic device, and storage medium

Abstract

The application discloses a battery swelling force determination method, an electronic device and a storage medium. The battery swelling force determination method comprises the following steps: acquiring charging and discharging data corresponding to charging and discharging parameters of a battery in a charging and discharging cycle process under different preset working conditions; wherein the preset working conditions comprise a preset temperature and a preset charging and discharging rate, and the charging and discharging parameters comprise a cycle number, a battery capacity parameter and a battery swelling force; determining an initial swelling force change model of the battery according to the relationship between the preset working conditions and the charging and discharging parameters; determining a target swelling force change model of the battery according to the initial swelling force change model and the charging and discharging data; determining a swelling force change amount of a to-be-tested battery according to a current working condition of the to-be-tested battery and the target swelling force change model, and determining a target swelling force of the to-be-tested battery according to the swelling force change amount and an initial swelling force of the to-be-tested battery. The technical scheme of the application realizes accurate determination of the swelling force of the battery, and avoids damage of the battery due to the swelling force exceeding a swelling force limit value.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a method for determining battery expansion force, an electronic device, and a storage medium. Background Technology

[0002] During use, batteries may swell, which affects their lifespan and can also damage the battery module if the expansion force exceeds the allowable limit, potentially leading to safety accidents. Therefore, studying the variation law of expansion force during the battery life cycle is of great significance for improving battery performance and safety.

[0003] Current research indicates that the increase in battery expansion force is linearly related to the number of cycles. However, due to the complex operating environment of batteries, the expansion force of a battery cannot be accurately determined based on the linear relationship between the increase in battery expansion force and the number of cycles. This may result in the battery expansion force exceeding the expansion force limit and causing damage. Summary of the Invention

[0004] This invention provides a method, electronic device, and storage medium for determining battery expansion force, so as to accurately determine the battery expansion force and avoid damage caused by the battery expansion force exceeding the expansion force limit.

[0005] According to one aspect of the present invention, a method for determining battery expansion force is provided, the method comprising:

[0006] The charging and discharging data corresponding to the charging and discharging parameters of the battery during the charging and discharging cycle under different preset operating conditions are obtained; wherein, the preset operating conditions include preset temperature and preset charge and discharge rate, and the charging and discharging parameters include cycle number, battery capacity parameters and battery expansion force;

[0007] The initial expansion force variation model of the battery is determined based on the relationship between the preset operating conditions and the charging and discharging parameters.

[0008] The target expansion force variation model of the battery is determined based on the initial expansion force variation model and the charge / discharge data.

[0009] The expansion force change of the battery under test is determined based on the current operating conditions of the battery under test and the target expansion force change model, and the target expansion force of the battery under test is determined based on the expansion force change and the initial expansion force of the battery under test.

[0010] Optionally, determining the target expansion force change model of the battery based on the initial expansion force change model and the charge / discharge data includes:

[0011] The initial expansion force variation model is transformed into an intermediate expansion force variation model based on the Arrhenius modified equation and the inverse power law model; wherein, the intermediate expansion force variation model includes a constant term, a rate factor, a temperature stress term, and a charge / discharge rate stress term;

[0012] Based on the discharge capacity data corresponding to the battery expansion force and the battery capacity parameters under different preset working conditions, determine the target constant, target rate coefficient, target expansion force growth factor, temperature stress coefficient, and charge / discharge rate stress coefficient corresponding to the constant term;

[0013] The target constant, target expansion factor, target expansion force growth factor, temperature stress term coefficient, and charge / discharge rate stress term coefficient are input into the intermediate expansion force variation model to obtain the target expansion force variation model.

[0014] Optionally, before converting the initial expansion force variation model into an intermediate expansion force variation model based on the Arrhenius modified equation and the inverse power law model, the method further includes:

[0015] Based on the relationship between the battery capacity retention rate corresponding to the battery capacity parameters and the preset operating conditions, the initial expansion force change model is expanded to update the initial expansion force change model.

[0016] Optionally, determining the target constant, target rate coefficient, target expansion force growth factor, temperature stress coefficient, and charge / discharge rate stress coefficient corresponding to the constant term based on the discharge capacity data corresponding to the battery expansion force and battery capacity parameters under different preset operating conditions includes:

[0017] Data preprocessing is performed on the discharge capacity data corresponding to the battery capacity parameters under different preset operating conditions to obtain the target discharge capacity data under different preset operating conditions;

[0018] Determine the temperature stress term coefficient and the charge / discharge rate stress term coefficient based on the target discharge capacity data;

[0019] Based on different preset operating conditions, the target constant, the target rate factor, and the target expansion force growth factor corresponding to the constant term are determined from the battery expansion force and discharge capacity data.

[0020] Optionally, determining the target constant, the target rate factor, and the target expansion force growth factor corresponding to the constant term based on the battery expansion force and discharge capacity data under different preset operating conditions includes:

[0021] Based on different preset operating conditions, multiple sets of initial constants, initial rate coefficients, and initial expansion force growth factors are obtained from the battery expansion force and discharge capacity data; wherein, one preset operating condition corresponds to one initial constant, one initial rate coefficient, and one initial expansion force growth factor.

[0022] One initial expansion force growth factor is selected from all the initial expansion force growth factors as the target expansion force growth factor. The initial constant, initial rate coefficient, target expansion force growth factor, temperature stress term coefficient, and charge / discharge rate stress term coefficient corresponding to the preset working condition are input into the intermediate expansion force variation model until the intermediate expansion force variation model is trained. The target expansion force growth factor is between the maximum and minimum values ​​of all the initial expansion force growth factors.

[0023] The target expansion force growth factor, temperature stress term coefficient, charge / discharge rate stress term coefficient, and discharge capacity data are input into the trained intermediate expansion force variation model to obtain the target constant and the target rate coefficient.

[0024] Optionally, the training of the intermediate expansion force variation model includes:

[0025] The calculated expansion force value output by the intermediate expansion force variation model meets the preset conditions.

[0026] Optionally, determining the initial expansion force change model of the battery based on the relationship between the preset operating conditions and the charging / discharging parameters includes:

[0027] Based on the relationship between the number of cycles, the battery capacity retention rate corresponding to the battery capacity parameters, and the battery expansion force under different preset operating conditions, the initial expansion force change model of the battery is determined.

[0028] Optionally, obtaining the charge and discharge data corresponding to the charge and discharge parameters of the battery during charge and discharge cycles under different preset operating conditions includes:

[0029] Control the battery to charge and discharge under preset operating conditions;

[0030] Obtain the charging and discharging data corresponding to the charging and discharging parameters after the battery has been charged and discharged, and return to execute the step of controlling the battery to charge and discharge under the preset operating conditions until the number of times the battery has been charged and discharged reaches the preset number.

[0031] Update the preset operating conditions, and return to the step of controlling the battery to charge and discharge under the preset operating conditions according to the updated preset operating conditions.

[0032] According to another aspect of the present invention, a battery expansion force determining device is provided, the device comprising:

[0033] The parameter acquisition module is used to acquire charge and discharge data corresponding to the charge and discharge parameters of the battery during the charge and discharge cycle under different preset operating conditions; wherein, the preset operating conditions include preset temperature and preset charge and discharge rate, and the charge and discharge parameters include cycle number, battery capacity parameters and battery expansion force;

[0034] The initial expansion force variation model determination module is used to determine the initial expansion force variation model of the battery based on the relationship between the preset operating conditions and the charging and discharging parameters.

[0035] The target expansion force variation model determination module is used to determine the target expansion force variation model of the battery based on the initial expansion force variation model and the charge / discharge data.

[0036] The target expansion force determination module is used to determine the expansion force change of the battery under test based on the current operating conditions of the battery under test and the target expansion force change model, and to determine the target expansion force of the battery under test based on the expansion force change and the initial expansion force of the battery under test.

[0037] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:

[0038] At least one processor; and

[0039] A memory communicatively connected to the at least one processor; wherein,

[0040] The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the battery expansion force determination method according to any embodiment of the present invention.

[0041] According to another aspect of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium storing computer instructions for causing a processor to execute and implement the battery expansion force determination method according to any embodiment of the present invention.

[0042] The technical solution of this invention sets different preset temperatures and preset charge / discharge rates, allowing the battery to undergo charge / discharge cycles under different preset operating conditions. Charge / discharge data corresponding to the battery's charge / discharge parameters during these cycles are obtained, facilitating the determination of the relationship between the battery's expansion force and preset temperature, preset charge / discharge rate, number of cycles, and battery capacity parameters. An initial expansion force change model is determined based on the relationship between the preset operating conditions and charge / discharge parameters. A target expansion force change model is then determined based on the initial expansion force change model and the charge / discharge data. By combining parameters such as battery temperature, charge / discharge rate, and number of cycles, the target expansion force change model accurately reflects the relationship between the battery's expansion force change, temperature, charge / discharge rate, and number of cycles. Therefore, the target expansion force change model allows for accurate calculation of the battery's expansion force change, facilitating accurate calculation of the battery's expansion force under test. Substituting the parameter values ​​corresponding to the current operating conditions of the battery under test into the target expansion force change model calculates the expansion force change. Adding or subtracting the expansion force change from the initial expansion force before charge / discharge gives the target expansion force of the battery under test. The technical solution of this invention solves the problem that the expansion force of the battery cannot be accurately determined, which may cause the battery to be damaged due to the expansion force exceeding the expansion force limit. It achieves accurate determination of the battery's expansion force and avoids damage caused by the battery's expansion force exceeding the expansion force limit.

[0043] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a flowchart of a method for determining battery expansion force provided in an embodiment of the present invention;

[0046] Figure 2 This is a flowchart of another method for determining battery expansion force provided by an embodiment of the present invention;

[0047] Figure 3 This is a flowchart of another method for determining battery expansion force provided by an embodiment of the present invention;

[0048] Figure 4This is a schematic diagram of a battery expansion force determination device provided in an embodiment of the present invention;

[0049] Figure 5 This is a schematic diagram of the structure of an electronic device that implements the battery expansion force determination method of this invention. Detailed Implementation

[0050] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0051] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0052] Figure 1 This is a flowchart of a method for determining battery expansion force provided by an embodiment of the present invention. Figure 1 As shown, the method for determining the battery expansion force includes:

[0053] S110. Obtain charge and discharge data corresponding to the charge and discharge parameters of the battery during charge and discharge cycles under different preset operating conditions; wherein, the preset operating conditions include preset temperature and preset charge and discharge rate, and the charge and discharge parameters include cycle number, battery capacity parameters and battery expansion force.

[0054] Specifically, the charge / discharge rate is used to represent the battery's charge / discharge capacity. It is calculated by dividing the charge / discharge current by the battery's rated capacity. 1C represents the current intensity when the battery is fully discharged in one hour. Preset charge / discharge rates include, for example, 0.5C and 1C, but other rates may also be included. Preset temperatures include, for example, 25°C, 35°C, and 45°C, but other temperatures may also be included. By setting different preset temperatures and preset charge / discharge rates, the battery undergoes charge / discharge cycles under different preset operating conditions. The charge / discharge data corresponding to the battery's charge / discharge parameters during these cycles are obtained, facilitating the determination of the relationship between the battery's expansion force and preset temperature, preset charge / discharge rate, number of cycles, and battery capacity parameters.

[0055] S120. Determine the initial expansion force variation model of the battery based on the relationship between the preset operating conditions and the charging and discharging parameters.

[0056] Specifically, by controlling the battery to undergo multiple charge-discharge cycles under different preset operating conditions within the battery's lifespan, such as when the battery's State of Health (SOH) is greater than or equal to 80%, charge-discharge data corresponding to the battery's charge-discharge parameters can be obtained. Based on the patterns in the charge-discharge data, the relationship between the change in the battery's expansion force and preset temperature, preset charge-discharge rate, number of cycles, and battery capacity parameters can be determined. In other words, by determining the relationship between the preset operating conditions and the charge-discharge parameters, the initial expansion force change model of the battery can be obtained.

[0057] S130. Determine the target expansion force change model of the battery based on the initial expansion force change model and charge / discharge data.

[0058] Specifically, by substituting multiple sets of charge-discharge data into the initial expansion force change model, the model parameters can be determined, such as the various coefficients and constants in the model. Substituting these model parameters into the initial expansion force change model yields the target expansion force change model for the battery. By combining parameters such as battery temperature, charge-discharge rate, and cycle count, the target expansion force change model is determined. This model accurately reflects the relationship between the battery's expansion force change, temperature, charge-discharge rate, and cycle count. Therefore, based on the target expansion force change model, the battery's expansion force change can be accurately calculated, facilitating accurate calculation of the battery's expansion force.

[0059] S140. Determine the change in expansion force of the battery under test based on the current operating conditions and the target expansion force change model, and determine the target expansion force of the battery under test based on the change in expansion force and the initial expansion force of the battery under test.

[0060] Specifically, the initial expansion force of the battery under test is the expansion force of the battery before it undergoes a charge-discharge cycle. When it is necessary to determine the expansion force of the battery under test, the current operating conditions of the battery are obtained, such as the current temperature and current charge / discharge rate. Substituting the parameter values ​​corresponding to the current operating conditions into the target expansion force change model, the change in expansion force of the battery under test can be calculated. Adding or subtracting the change in expansion force from the initial expansion force of the battery before charge / discharge gives the target expansion force of the battery under test. By comparing the expansion force of the battery under test with its expansion force limit, if the expansion force exceeds the limit, alarms or power-off operations can be initiated to prevent damage to the battery and improve its safety performance.

[0061] The technical solution of this embodiment sets different preset temperatures and preset charge / discharge rates, allowing the battery to undergo charge / discharge cycles under different preset operating conditions. It acquires charge / discharge data corresponding to the battery's charge / discharge parameters during these cycles, facilitating the determination of the relationship between the battery's expansion force and preset temperature, preset charge / discharge rate, number of cycles, and battery capacity parameters. An initial expansion force change model is determined based on the relationship between the preset operating conditions and charge / discharge parameters. A target expansion force change model is then determined based on the initial expansion force change model and the charge / discharge data. By combining parameters such as battery temperature, charge / discharge rate, and number of cycles, the target expansion force change model accurately reflects the relationship between the battery's expansion force change, temperature, charge / discharge rate, and number of cycles. Therefore, the target expansion force change model allows for accurate calculation of the battery's expansion force change, facilitating accurate calculation of the battery's expansion force under test. Substituting the parameter values ​​corresponding to the current operating conditions of the battery under test into the target expansion force change model calculates the expansion force change. Adding or subtracting the expansion force change from the initial expansion force before charge / discharge gives the target expansion force of the battery under test. The technical solution of this embodiment solves the problem that the expansion force of the battery cannot be accurately determined, which may cause the battery expansion force to exceed the expansion force limit and be damaged. It realizes the accurate determination of the battery expansion force and avoids the battery expansion force exceeding the expansion force limit and being damaged.

[0062] Based on the above technical solution, optionally, an initial expansion force variation model for the battery can be determined according to the relationship between preset operating conditions and charging / discharging parameters, including:

[0063] Based on the relationship between the number of cycles, battery capacity retention rate, and battery expansion force corresponding to different preset operating conditions, the initial expansion force variation model of the battery is determined.

[0064] Specifically, changes in battery expansion force include stress changes caused by temperature variations and stress changes caused by charge / discharge rates. Battery capacity retention refers to the ratio of the battery's current capacity to its standard capacity. The number of charge / discharge cycles, battery temperature, and charge / discharge rate affect the battery's capacity retention rate. Therefore, the battery's capacity retention rate Q can be considered a function of the number of charge / discharge cycles N, temperature T, and charge / discharge rate C. The initial expansion force change model of the battery can then be expressed as ΔF = A + B * Q(C, T, N). D Where ΔF is the change in battery expansion force, A is a constant, B is the rate factor, D is the expansion force growth factor, C is the charge / discharge rate of the battery, N is the number of charge / discharge cycles of the battery, T is the battery temperature, and Q is the battery capacity retention rate.

[0065] Figure 2 This is a flowchart of another method for determining battery expansion force provided by an embodiment of the present invention. Optionally, refer to... Figure 2 Methods for determining battery expansion force include:

[0066] S210. Obtain charge and discharge data corresponding to the charge and discharge parameters of the battery during charge and discharge cycles under different preset operating conditions; wherein, the preset operating conditions include preset temperature and preset charge and discharge rate, and the charge and discharge parameters include cycle number, battery capacity parameters and battery expansion force.

[0067] S220. Determine the initial expansion force variation model of the battery based on the relationship between the preset operating conditions and the charging and discharging parameters.

[0068] S230. Based on the relationship between the battery capacity retention rate corresponding to the battery capacity parameters and the preset operating conditions, expand the initial expansion force change model to update the initial expansion force change model.

[0069] Specifically, the battery charge / discharge data includes the battery capacity retention rate. Based on the relationship between the battery capacity retention rate Q and the battery temperature T, the battery charge / discharge rate C, and the number of charge / discharge cycles N, the initial expansion force change model is expanded to obtain the updated initial expansion force change model. Where F1(T) and F3(T) are functions of battery temperature change, and F2(C) and F4(C) are functions of battery charge / discharge rate change.

[0070] S240. Based on the Arrhenius modified equation and the inverse power law model, the initial expansion force variation model is transformed into an intermediate expansion force variation model; wherein, the intermediate expansion force variation model includes a constant term, a rate factor, a temperature stress term, and a charge / discharge rate stress term.

[0071] Specifically, the Arrhenius modified equation is an empirical formula established by the Swedish scientist Arrhenius regarding the relationship between the chemical reaction rate constant and temperature. The formula is written as... Where k is the rate constant, R is the molar gas constant, T1 is the thermodynamic temperature, Ea is the apparent activation energy, and n is the pre-exponential factor (also known as the frequency factor). The inverse power-law model shows that the component lifetime is inversely proportional to the power of the principal stress. Therefore, based on the Arrhenius modified equation and the inverse power-law model, the initial expansion force variation model... In this context, F1(T) can be expressed as F2(C) can be expressed as F2(C) = e (d*C+e) F3(T) can be expressed as F3(T) = f*T 2 +g*T, F4(C) can be expressed as F4(C)=h*C+i. Substituting the expressions for F1(T), F2(C), F3(T), and F4(C) into the initial expansion force variation model, the intermediate expansion force variation model can be obtained. Where A is the constant term of the intermediate expansion force variation model, B is the rate coefficient, a, b, c, f and g are the temperature stress coefficients, and d, e, h and i are the charge / discharge rate stress coefficients.

[0072] S250. Based on the discharge capacity data corresponding to the battery expansion force and battery capacity parameters under different preset working conditions, determine the target constant, target rate coefficient, target expansion force growth factor, temperature stress coefficient, and charge / discharge rate stress coefficient corresponding to the constant terms.

[0073] Specifically, the battery charge / discharge data includes the battery's discharge capacity data. Based on the discharge capacity data corresponding to the battery expansion force and battery capacity parameters under different preset operating conditions, a fitting process is performed to determine the target constant, target rate coefficient, target expansion force growth factor, temperature stress coefficient, and charge / discharge rate stress coefficient corresponding to the constant terms. This facilitates the determination of the coefficient values ​​in the target expansion force variation model, thereby defining the target expansion force variation model.

[0074] S260. Input the target constant, target expansion factor, target expansion force growth factor, temperature stress term coefficient, and charge / discharge rate stress term coefficient into the intermediate expansion force variation model to obtain the target expansion force variation model.

[0075] Specifically, by determining the target expansion force change model, the change in expansion force of the battery under test can be calculated, thereby determining the expansion force of the battery under test, which makes it easier to determine whether the expansion force of the battery under test exceeds the expansion force limit.

[0076] S270. Determine the change in expansion force of the battery under test based on the current operating conditions and the target expansion force change model, and determine the target expansion force of the battery under test based on the change in expansion force and the initial expansion force of the battery under test.

[0077] Based on the above technical solutions, Figure 3This is a flowchart of another method for determining battery expansion force provided by an embodiment of the present invention. Optionally, refer to... Figure 3 Methods for determining battery expansion force include:

[0078] S310. Obtain charge and discharge data corresponding to charge and discharge parameters during the charge and discharge cycle of the battery under different preset operating conditions; wherein, the preset operating conditions include preset temperature and preset charge and discharge rate, and the charge and discharge parameters include cycle number, battery capacity parameters and battery expansion force.

[0079] S320. Determine the initial expansion force variation model of the battery based on the relationship between the preset operating conditions and the charging and discharging parameters.

[0080] S330. Based on the relationship between the battery capacity retention rate corresponding to the battery capacity parameters and the preset operating conditions, expand the initial expansion force change model to update the initial expansion force change model.

[0081] S340. Based on the Arrhenius modified equation and the inverse power law model, the initial expansion force variation model is transformed into an intermediate expansion force variation model; wherein, the intermediate expansion force variation model includes a constant term, a rate factor, a temperature stress term, and a charge / discharge rate stress term.

[0082] S350: Perform data preprocessing on the discharge capacity data corresponding to the battery capacity parameters under different preset operating conditions to obtain the target discharge capacity data under different preset operating conditions.

[0083] Specifically, data preprocessing of the discharge capacity data, such as filtering, is performed to remove data noise and obtain clean target discharge capacity data. Surface noise data interferes with the calculation of model parameters, thereby further improving the accuracy of the target expansion force change model and thus improving the accuracy of expansion force calculation.

[0084] S360. Determine the temperature stress term coefficient and the charge / discharge rate stress term coefficient based on the target discharge capacity data.

[0085] Specifically, for example, the target discharge capacity data is fitted based on the Gaussian degradation equation, and the relationship between the target discharge capacity data and the capacity retention rate Q and the number of battery charge-discharge cycles N under various operating conditions is analyzed. The initial values ​​of F1(T)*F2(C) and F3(T)+F4(C) are obtained by formal fitting. Then, the preset charge / discharge rate C and preset battery temperature T corresponding to the preset operating conditions are substituted into F1(T)*F2(C) and F3(T)+F4(C) for calculation to obtain the correlation coefficients a, b, c, e, f, g, h and i, thereby determining the expression of the battery capacity retention rate Q.

[0086] S370. Based on the battery expansion force and discharge capacity data under different preset operating conditions, determine the target constant, target rate coefficient, and target expansion force growth factor corresponding to the constant term.

[0087] Specifically, after removing data noise, the battery expansion force and discharge capacity data under each preset operating condition are fitted to obtain multiple sets of initial constants, initial rate coefficients, and initial expansion force growth factors. One initial expansion force growth factor is selected from all these as the target expansion force growth factor, ensuring that the calculated expansion force value obtained after substituting the initial constants, initial rate coefficients, target expansion force growth factors, temperature stress coefficients, and charge / discharge rate stress coefficients corresponding to the preset operating condition into the intermediate expansion force variation model is close to the measured value. Then, the target expansion force growth factor, temperature stress coefficient, and charge / discharge rate stress coefficient are substituted into the intermediate expansion force variation model, and the target constant and target rate coefficient corresponding to the constant term are determined in conjunction with the discharge capacity data.

[0088] S380. Input the target constant, target expansion factor, target expansion force growth factor, temperature stress term coefficient, and charge / discharge rate stress term coefficient into the intermediate expansion force variation model to obtain the target expansion force variation model.

[0089] S390. Determine the change in expansion force of the battery under test based on the current operating conditions and the target expansion force change model, and determine the target expansion force of the battery under test based on the change in expansion force and the initial expansion force of the battery under test.

[0090] Based on the above technical solution, optionally, S307, according to the battery expansion force and discharge capacity data under different preset operating conditions, determines the target constant, target rate coefficient, and target expansion force growth factor corresponding to the constant term, including:

[0091] Step a1: Based on the battery expansion force and discharge capacity data under different preset operating conditions, obtain multiple sets of initial constants, initial rate coefficients and initial expansion force growth factors; wherein, one preset operating condition corresponds to one initial constant, one initial rate coefficient and one initial expansion force growth factor.

[0092] Specifically, under each preset operating condition, the battery expansion force and discharge capacity data corresponding to the preset operating condition are fitted to obtain the initial constant, initial rate coefficient and initial expansion force growth factor corresponding to each preset operating condition, thus obtaining multiple sets of initial constant, initial rate coefficient and initial expansion force growth factor.

[0093] Step a2: Select one initial expansion force growth factor from all initial expansion force growth factors as the target expansion force growth factor. Substitute the initial constant, initial rate coefficient, target expansion force growth factor, temperature stress term coefficient, and charge / discharge rate stress term coefficient corresponding to the preset working condition into the input intermediate expansion force change model until the intermediate expansion force change model is trained. The target expansion force growth factor is between the maximum and minimum values ​​of all initial expansion force growth factors.

[0094] Specifically, an initial expansion force growth factor is selected from the maximum and minimum values ​​of all initial expansion force growth factors as the target expansion force growth factor. The selection of the target expansion force growth factor should ensure that the initial constant, initial rate coefficient, target expansion force growth factor, temperature stress term coefficient, and charge / discharge rate stress term coefficient corresponding to the preset working condition are input into the intermediate expansion force variation model. If the output value of the intermediate expansion force variation model meets the preset conditions, the intermediate expansion force variation model is trained and the selected target expansion force growth factor is appropriate and can be used as the final target expansion force growth factor. If the output value of the intermediate expansion force variation model does not meet the preset conditions, the initial expansion force growth factor is reselected as the target expansion force growth factor, that is, the intermediate expansion force variation model is trained again until the intermediate expansion force variation model is trained.

[0095] Optionally, the intermediate expansion force variation model training is completed, including:

[0096] The calculated expansion force value output by the intermediate expansion force variation model meets the preset conditions.

[0097] Specifically, the battery is charged and discharged under preset operating conditions, and the expansion force of the battery after the cycle is measured to obtain the measured expansion force value corresponding to the preset operating conditions. The calculated expansion force value meets preset conditions, such as a small difference between the calculated expansion force value and the corresponding measured expansion force value, or the smallest variance obtained from the difference between each calculated expansion force value and the corresponding measured expansion force value. If the calculated expansion force value obtained after inputting the initial constant, initial rate coefficient, target expansion force growth factor, temperature stress term coefficient, and charge / discharge rate stress term coefficient corresponding to the preset operating conditions into the intermediate expansion force variation model satisfies the preset relationship with the measured expansion force value, then the intermediate expansion force variation model training is complete, and the selected target expansion force growth factor is appropriate and can be used as the final target expansion force growth factor.

[0098] Step a3: Input the target expansion force growth factor, temperature stress term coefficient, charge / discharge rate stress term coefficient, and discharge capacity data into the trained intermediate expansion force change model to obtain the target constant and target rate coefficient.

[0099] Specifically, taking lithium iron phosphate batteries as an example, the target expansion force growth factor was ultimately determined to be 4.05. Based on the target expansion force growth factor, temperature stress term coefficient, and charge / discharge rate stress term coefficient, the model was updated to obtain the target constants and target rate coefficients under different preset operating conditions. For operating conditions not included in the preset conditions, the target constants and target rate coefficients can be obtained through linear interpolation. Taking lithium iron phosphate batteries as an example, the target constants and target rate coefficients under different preset operating conditions are obtained. Table 1 shows the target constant A and target rate coefficient B corresponding to different preset operating conditions.

[0100] Table 1 Target constant A and target multiplier coefficient B corresponding to different preset working conditions

[0101]

[0102] As shown in Table 1, when the preset operating conditions are a preset temperature of 25℃ and a preset charge / discharge rate of 1C, the target constant A is -569 and the target rate factor B is 550; when the preset operating conditions are a preset temperature of 35℃ and a preset charge / discharge rate of 1C, the target constant A is -672 and the target rate factor B is 639; when the preset operating conditions are a preset temperature of 45℃ and a preset charge / discharge rate of 1C, the target constant A is -816 and the target rate factor B is 779; when the preset operating conditions are a preset temperature of 25℃ and a preset charge / discharge rate of 0.5C, the target constant A is -536 and the target rate factor B is 506; when the preset operating conditions are a preset temperature of 35℃ and a preset charge / discharge rate of 0.5C, the target constant A is -600 and the target rate factor B is 561; and when the preset operating conditions are a preset temperature of 45℃ and a preset charge / discharge rate of 0.5C, the target constant A is -739 and the target rate factor B is 710.

[0103] Optionally, S301 acquires charge and discharge data corresponding to the charge and discharge parameters of the battery during charge and discharge cycles under different preset operating conditions, including:

[0104] Step b1: Control the battery to charge and discharge under preset operating conditions.

[0105] Specifically, preset operating conditions include, for example, preset temperature and preset charge / discharge rate, which control the battery to charge and discharge under preset conditions to complete one charge / discharge cycle. Charging, for example, means charging to the battery's maximum capacity, and discharging, for example, means discharging to the battery's minimum capacity. The minimum capacity is, for example, greater than zero, to prevent the battery from being damaged due to excessively low capacity.

[0106] Step b2: Obtain the charge and discharge data corresponding to the charge and discharge parameters after the battery has been charged and discharged.

[0107] Specifically, after the battery completes one charge and discharge cycle, the charge and discharge data corresponding to the battery's charge and discharge parameters are obtained, such as the number of charge and discharge cycles, and other charge and discharge data, such as battery capacity retention rate, battery expansion force, and other data corresponding to battery parameters. This embodiment does not limit these data.

[0108] Step b3: Determine whether the number of battery charge / discharge cycles has reached the preset number. If yes, proceed to step b4; otherwise, return to step b1.

[0109] Specifically, the number of times the battery is charged and discharged is the number of battery cycles. If the number of times the battery is charged and discharged reaches the preset number, the preset operating conditions can be changed to obtain the charging and discharging parameters of the battery under different preset operating conditions. If the number of times the battery is charged and discharged has not reached the preset number, the battery will continue to be controlled to charge and discharge until the number of times the battery is charged and discharged reaches the preset number.

[0110] Step b4: Determine whether the battery is being charged and discharged under all preset operating conditions. If yes, end; otherwise, proceed to step b5.

[0111] Specifically, there can be multiple preset operating conditions. If the battery has been charging and discharging under all the preset operating conditions, the charging and discharging will end. If the battery has not been charging and discharging under all the preset operating conditions, the preset operating conditions will be changed, and the battery will continue to be controlled to charge and discharge under the preset operating conditions until all preset operating conditions have been traversed.

[0112] Step b5: Change the preset operating conditions, and return to step b1 based on the updated preset operating conditions.

[0113] Specifically, the preset operating conditions can be changed, such as changing the preset temperature or the preset charge / discharge rate. Alternatively, both the preset temperature and the preset charge / discharge rate can be changed simultaneously, so that the battery can complete charging and discharging under all preset operating conditions.

[0114] Figure 4 This is a schematic diagram of a battery expansion force determination device provided in an embodiment of the present invention. Figure 4As shown, the battery expansion force determination device includes a parameter acquisition module 410, an initial expansion force change model determination module 420, a target expansion force change model determination module 430, and a target expansion force determination module 440. The parameter acquisition module 410 is used to acquire charge and discharge data corresponding to charge and discharge parameters during charge and discharge cycles under different preset operating conditions. The preset operating conditions include a preset temperature and a preset charge and discharge rate, and the charge and discharge parameters include the number of cycles, battery capacity parameters, and battery expansion force. The initial expansion force change model determination module 420 is used to determine the initial expansion force change model of the battery based on the relationship between the preset operating conditions and the charge and discharge parameters. The target expansion force change model determination module 430 is used to determine the target expansion force change model of the battery based on the initial expansion force change model and the charge and discharge data. The target expansion force determination module 440 is used to determine the expansion force change of the battery under test based on the current operating conditions and the target expansion force change model, and to determine the target expansion force of the battery under test based on the expansion force change and the initial expansion force of the battery under test.

[0115] Optionally, the target expansion force variation model determination module 430 is specifically used to convert the initial expansion force variation model into an intermediate expansion force variation model based on the Arrhenius modified equation and the inverse power law model; wherein, the intermediate expansion force variation model includes constant terms, rate coefficients, temperature stress terms, and charge / discharge rate stress terms; based on the discharge capacity data corresponding to the battery expansion force and battery capacity parameters under different preset operating conditions, the target constant, target rate coefficient, target expansion force growth factor, temperature stress term coefficient, and charge / discharge rate stress term coefficient corresponding to the constant terms are determined; the target constant, target rate coefficient, target expansion force growth factor, temperature stress term coefficient, and charge / discharge rate stress term coefficient are input into the intermediate expansion force variation model to obtain the target expansion force variation model.

[0116] The battery expansion force determination device provided in the embodiments of the present invention can execute the battery expansion force determination method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the method.

[0117] Figure 5 This is a schematic diagram of an electronic device implementing the battery expansion force determination method of this invention. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0118] like Figure 5 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 may also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0119] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of displays, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0120] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as the battery expansion force determination method.

[0121] In some embodiments, the battery swelling force determination method may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or mounted on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the battery swelling force determination method described above may be performed. Alternatively, in other embodiments, processor 11 may be configured to perform the battery swelling force determination method by any other suitable means (e.g., by means of firmware).

[0122] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0123] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0124] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0125] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0126] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0127] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0128] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0129] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for determining battery expansion force, characterized in that, include: The charging and discharging data corresponding to the charging and discharging parameters of the battery during the charging and discharging cycle under different preset operating conditions are obtained; wherein, the preset operating conditions include preset temperature and preset charge and discharge rate, and the charging and discharging parameters include cycle number, battery capacity parameters and battery expansion force; The initial expansion force variation model of the battery is determined based on the relationship between the preset operating conditions and the charging and discharging parameters. The target expansion force variation model of the battery is determined based on the initial expansion force variation model and the charge / discharge data. The expansion force change of the battery under test is determined based on the current operating conditions of the battery under test and the target expansion force change model, and the target expansion force of the battery under test is determined based on the expansion force change and the initial expansion force of the battery under test. Determining the target expansion force change model of the battery based on the initial expansion force change model and the charge / discharge data includes: The initial expansion force variation model is transformed into an intermediate expansion force variation model based on the Arrhenius modified equation and the inverse power law model; wherein, the intermediate expansion force variation model includes a constant term, a rate factor, a temperature stress term, and a charge / discharge rate stress term; Based on the discharge capacity data corresponding to the battery expansion force and the battery capacity parameters under different preset working conditions, determine the target constant, target rate coefficient, target expansion force growth factor, temperature stress coefficient, and charge / discharge rate stress coefficient corresponding to the constant term; The target constant, target expansion factor, target expansion force growth factor, temperature stress term coefficient, and charge / discharge rate stress term coefficient are input into the intermediate expansion force variation model to obtain the target expansion force variation model.

2. The method according to claim 1, characterized in that, Before converting the initial expansion force variation model into an intermediate expansion force variation model based on the Arrhenius modified equation and the inverse power law model, the following steps are also included: Based on the relationship between the battery capacity retention rate corresponding to the battery capacity parameters and the preset operating conditions, the initial expansion force change model is expanded to update the initial expansion force change model.

3. The method according to claim 1, characterized in that, The step of determining the target constant, target rate coefficient, target expansion force growth factor, temperature stress coefficient, and charge / discharge rate stress coefficient corresponding to the constant term based on the discharge capacity data corresponding to the battery expansion force and battery capacity parameters under different preset operating conditions includes: Data preprocessing is performed on the discharge capacity data corresponding to the battery capacity parameters under different preset operating conditions to obtain the target discharge capacity data under different preset operating conditions; Determine the temperature stress term coefficient and the charge / discharge rate stress term coefficient based on the target discharge capacity data; Based on different preset operating conditions, the target constant, the target rate factor, and the target expansion force growth factor corresponding to the constant term are determined from the battery expansion force and discharge capacity data.

4. The method according to claim 3, characterized in that, The step of determining the target constant, the target rate factor, and the target expansion force growth factor corresponding to the constant term based on the battery expansion force and discharge capacity data under different preset operating conditions includes: Based on different preset operating conditions, multiple sets of initial constants, initial rate coefficients, and initial expansion force growth factors are obtained from the battery expansion force and discharge capacity data; wherein, one preset operating condition corresponds to one initial constant, one initial rate coefficient, and one initial expansion force growth factor. One initial expansion force growth factor is selected from all the initial expansion force growth factors as the target expansion force growth factor. The initial constant, initial rate coefficient, target expansion force growth factor, temperature stress term coefficient, and charge / discharge rate stress term coefficient corresponding to the preset working condition are input into the intermediate expansion force variation model until the intermediate expansion force variation model is trained. The target expansion force growth factor is between the maximum and minimum values ​​of all the initial expansion force growth factors. The target expansion force growth factor, temperature stress term coefficient, charge / discharge rate stress term coefficient, and discharge capacity data are input into the trained intermediate expansion force variation model to obtain the target constant and the target rate coefficient.

5. The method according to claim 4, characterized in that, The intermediate expansion force variation model has been trained, including: The calculated expansion force value output by the intermediate expansion force variation model meets the preset conditions.

6. The method according to any one of claims 1 to 5, characterized in that, The step of determining the initial expansion force change model of the battery based on the relationship between the preset operating conditions and the charging and discharging parameters includes: Based on the relationship between the number of cycles, the battery capacity retention rate corresponding to the battery capacity parameters, and the battery expansion force under different preset operating conditions, the initial expansion force change model of the battery is determined.

7. The method according to any one of claims 1 to 5, characterized in that, The step of obtaining charge and discharge data corresponding to the charge and discharge parameters of the battery during charge and discharge cycles under different preset operating conditions includes: Control the battery to charge and discharge under preset operating conditions; Obtain the charging and discharging data corresponding to the charging and discharging parameters after the battery has been charged and discharged, and return to execute the step of controlling the battery to charge and discharge under the preset operating conditions until the number of times the battery has been charged and discharged reaches the preset number. Update the preset operating conditions, and return to the step of controlling the battery to charge and discharge under the preset operating conditions according to the updated preset operating conditions.

8. An electronic device, characterized in that, The electronic device includes: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor to enable the at least one processor to perform the battery expansion force determination method according to any one of claims 1-7.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that cause a processor to execute the battery expansion force determination method according to any one of claims 1-7.

Images