Battery expansion force prediction method, electronic equipment and storage medium
By acquiring the battery's lifespan degradation temperature and charge/discharge parameters, the correlation between the battery's expansion force under different health conditions is established, solving the problem of low efficiency in battery expansion force prediction and improving the accuracy and efficiency of battery expansion force prediction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- EVE POWER CO LTD
- Filing Date
- 2025-12-22
- Publication Date
- 2026-04-21
AI Technical Summary
Existing battery expansion force prediction methods require at least one measurement for each battery, resulting in a long measurement time for multiple batteries and a lack of efficiency.
By acquiring the lifetime decay temperature and charge/discharge parameters of the target battery, performing charge/discharge cycles, establishing the correlation between the battery's expansion force under different health conditions, and using this correlation to predict the battery's expansion force under a specified health condition.
This improved the accuracy and efficiency of battery expansion force prediction, shortened the testing cycle, and ensured the authenticity of battery aging mechanisms and the rationality of expansion force testing.
Smart Images
Figure CN121899673A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of expansion force prediction technology, specifically to battery expansion force prediction methods, electronic devices, and storage media. Background Technology
[0002] In related technologies, a common method for predicting battery expansion force is to directly measure it using a pressure sensor installed on the battery surface. However, this method is not applicable, as at least one measurement using a pressure sensor is required for each different battery to obtain the expansion force result. Therefore, measuring the expansion force of multiple different batteries takes a long time. Summary of the Invention
[0003] A method for predicting battery expansion force is provided, aiming to improve the prediction efficiency of battery expansion force.
[0004] In a first aspect, a method for predicting battery expansion force is provided, comprising the following steps: Obtain the target temperature and target charge / discharge parameters that accelerate the degradation of the target battery's lifespan; Based on the target temperature and target charge / discharge parameters, the target battery is subjected to charge / discharge cycles to obtain the expansion force of the target battery under multiple healthy states. Based on multiple health states and corresponding expansion forces, the correlation between the target battery's health state and expansion force is determined. Based on the correlation, the predicted expansion force of the target battery under a specified health condition is determined.
[0005] In one embodiment, the correlation between the target battery's health state and expansion force is determined based on multiple health states and corresponding expansion forces, including: Based on the difference in expansion force between the expansion forces corresponding to multiple health states, multiple target health states are determined among the multiple health states. Based on multiple target health states and corresponding expansion forces, the correlation between the target battery's health state and expansion force is determined.
[0006] In this embodiment, by determining multiple target health states among multiple health states, and by determining the correlation between the target battery's health state and expansion force based on the multiple target health states and the corresponding expansion force, the accuracy of the correlation can be guaranteed, thereby improving the accuracy of the target battery's expansion force prediction.
[0007] In one embodiment, multiple target health states are determined among multiple health states based on the difference in expansion forces between the expansion forces corresponding to multiple health states, including: Based on the difference in expansion force between multiple health states, the difference variables corresponding to the multiple health states are determined. In the health states where the difference variable meets the preset variable threshold, multiple target health states are determined.
[0008] In this embodiment, by determining multiple target health states based on the difference variables corresponding to multiple health states, the accuracy of multiple target health states can be guaranteed, the accuracy of the linear function between the target battery's health state and expansion force can be accurately obtained, and thus the accuracy of the expansion force prediction of the target battery can be guaranteed.
[0009] In one embodiment, multiple target health states include inflection point health states, specifying that a health state is less than the inflection point health state.
[0010] In this embodiment, the predicted expansion force of the target battery in a specified health state is predicted by determining the correlation between multiple target health states and corresponding expansion forces. Furthermore, since the specified health state is less than the inflection point health state, the prediction accuracy of the expansion force can be guaranteed.
[0011] In one embodiment, the battery expansion force prediction method further includes: The expansion force and cycle period of the sample battery during charge and discharge cycles were obtained under multiple test temperatures and corresponding test charge and discharge parameters. Based on the expansion force of the sample battery during charge-discharge cycles at multiple test temperatures and corresponding test charge-discharge parameters, candidate charge-discharge parameters at multiple test temperatures are determined. The target temperature and target charge / discharge parameters are determined based on the cycle period corresponding to the candidate charge / discharge parameters at each test temperature.
[0012] In this embodiment, the optimal stress conditions for accelerating battery aging were scientifically determined through multi-dimensional test data. This can significantly shorten the test cycle and achieve accelerated aging and accelerated expansion force testing of the battery while ensuring the authenticity of the battery aging mechanism.
[0013] In one embodiment, candidate charge-discharge parameters at multiple test temperatures are determined based on the expansion force of the sample battery during charge-discharge cycles at multiple test temperatures and corresponding test charge-discharge parameters, including: For any given test temperature and multiple corresponding test charge and discharge parameters, obtain the expansion force of the sample battery during the charge and discharge cycle at the test temperature and multiple corresponding test charge and discharge parameters; Based on the expansion force variation data corresponding to multiple test charge and discharge parameters, candidate charge and discharge parameters at the test temperature are determined, thus obtaining candidate charge and discharge parameters at multiple test temperatures.
[0014] In this embodiment, by determining the candidate charge-discharge parameters at the test temperature based on the expansion force change data corresponding to the expansion forces of multiple test charge-discharge parameters, it is possible to ensure the rationality of the battery expansion during cyclic charge-discharge at each test temperature according to the candidate charge-discharge parameters. This can be understood as the expansion force obtained by the battery under different test temperatures and corresponding candidate charge-discharge parameters being normal and consistent with the battery expansion law, thus effectively collecting the battery's expansion force.
[0015] In one embodiment, candidate charge / discharge parameters at the test temperature are determined based on the expansion force variation data corresponding to multiple test charge / discharge parameters, including: Based on the difference between the expansion forces corresponding to multiple test currents, the expansion force change data is obtained; Test charge-discharge parameters whose expansion force change data is less than the preset expansion force change threshold are determined as candidate charge-discharge parameters at the test temperature.
[0016] In this embodiment, by determining the candidate charge-discharge parameters at the test temperature based on the expansion force change data corresponding to the expansion forces of multiple test charge-discharge parameters, it is possible to ensure the rationality of the battery expansion during cyclic charge-discharge at each test temperature according to the candidate charge-discharge parameters. This can be understood as the expansion force obtained by the battery under different test temperatures and corresponding candidate charge-discharge parameters being normal and consistent with the battery expansion law, thus effectively collecting the battery's expansion force.
[0017] In one embodiment, the target temperature and target charge / discharge parameters are determined based on the cycle number corresponding to the candidate charge / discharge parameters at each test temperature, including: Based on the cycle periods corresponding to the candidate charge-discharge parameters at multiple test temperatures, the test temperature and the corresponding candidate charge-discharge parameters corresponding to the minimum cycle period are determined as the target temperature and target charge-discharge parameters.
[0018] In this embodiment, by determining the target temperature and target charge / discharge parameters based on the cycle period, among the test temperature and corresponding candidate charge / discharge parameters, the optimal cycle conditions for accelerated battery aging can be guaranteed, thereby realizing the accelerated expansion force test of the battery and improving the expansion force prediction efficiency of the target battery.
[0019] Secondly, this application also provides a battery expansion force prediction device, the device comprising: The data acquisition module is used to acquire the target temperature and target charge / discharge parameters that accelerate the degradation of the target battery life; The accelerated expansion module is used to perform charge-discharge cycles on the target battery based on the target temperature and target charge-discharge parameters, and obtain the expansion force of the target battery under multiple health states. The relationship establishment module is used to determine the correlation between the target battery's health state and expansion force based on multiple health states and corresponding expansion forces. The prediction module is used to determine the predicted expansion force of a target battery under a specified health condition based on correlation relationships.
[0020] Thirdly, this application also provides an electronic device, including a memory and a processor, the memory storing a computer program for controlling the processor to operate in order to perform the methods in any of the embodiments of any of the above aspects.
[0021] Fourthly, this application also provides a computer-readable storage medium including computer instructions that, when executed by a processor, implement the methods in any of the embodiments described above.
[0022] Fifthly, the present application provides a computer program product that, when executed by a processor, implements the method in any of the above-described embodiments.
[0023] Beneficial effects: This application obtains the target temperature and target charge / discharge parameters for accelerating the degradation of the target battery's lifespan, and performs charge / discharge cycles on the target battery based on the target temperature and target charge / discharge parameters. This accelerates battery aging and obtains the expansion force corresponding to the target battery under multiple health states, thereby achieving accelerated expansion of the target battery. Furthermore, based on the multiple health states of the target battery and the corresponding expansion force, the correlation between the target battery's health state and expansion force is determined, and this correlation is used to determine the predicted expansion force of the target battery under a specified health state, ensuring the accuracy of the expansion force prediction for the target battery. Attached Figure Description
[0024] To more clearly illustrate the technical solutions in the embodiments of this application, 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0025] Figure 1 This is a flowchart illustrating the battery expansion force prediction method provided by an exemplary embodiment of this disclosure; Figure 2 This is another flowchart illustrating the battery expansion force prediction method provided by an exemplary embodiment of this disclosure; Figure 3 This is a flowchart illustrating the battery expansion force prediction steps provided in an exemplary embodiment of this disclosure. Figure 4 This is a schematic diagram of a battery expansion force prediction device provided in some embodiments of this application; Figure 5 These are internal structural diagrams of electronic devices provided in some embodiments of this application. Detailed Implementation
[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0027] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0028] In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use this application. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that this application can be made without using these specific details. In other instances, well-known structures and processes are not described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.
[0029] On the one hand, this embodiment provides a method for predicting battery expansion force, such as... Figure 1 As shown, it includes the following steps: S101, obtain the target temperature and target charge / discharge parameters that accelerate the degradation of the target battery life.
[0030] The target battery refers to the battery for which expansion force prediction is required. The target temperature and target charge / discharge parameters are the test conditions for the target battery during charge / discharge cycles, used to rapidly bring the target battery to multiple health states. These can be understood as cyclic test conditions that accelerate the degradation of the target battery's lifespan (i.e., accelerate battery aging). The target temperature refers to the ambient temperature at which the target battery undergoes cyclic charge / discharge. The target charge / discharge parameters include the target current and target power. The target current refers to the charge / discharge rate at which the target battery undergoes cyclic charge / discharge. The target power refers to the charge / discharge power at which the target battery undergoes cyclic charge / discharge. The target power is positively correlated with the target current; therefore, either the target current or the target power can be selected and combined with the target temperature to obtain the cyclic conditions that accelerate the degradation of the target battery's lifespan.
[0031] For example, the terminal is communicatively connected to a battery testing device and a temperature control device. The battery testing device provides charging and discharging functions for the battery, and the temperature control device provides the required temperature for the battery during charge-discharge cycles. The target battery is connected to the battery testing device, and the target battery is placed within the temperature control area of the temperature control device.
[0032] The terminal responds to the cyclic testing command for the target battery, acquiring the target temperature and target charge / discharge parameters to accelerate the battery's lifespan degradation. These parameters can be obtained based on the target battery type. The target current and target temperature or target power are obtained based on the expansion force and cycle time of the sample battery during charge / discharge cycles at multiple test temperatures and multiple test currents or multiple test powers. The sample battery and the target battery have the same battery type; for example, the target battery is a lithium iron phosphate (LFP) battery. The target current includes the target charging current and the target discharging current; generally, the current ratios of the target charging current and the target discharging current are the same. The test current includes the test charging current and the test discharging current; generally, the current ratios of the test charging current and the test discharging current are the same. The cycle time refers to the number of cycles the sample battery takes to reach a preset healthy state during charge / discharge cycles, such as the number of cycles.
[0033] S102, based on the target temperature and target charge / discharge parameters, performs charge / discharge cycles on the target battery to obtain the expansion force of the target battery under multiple health states.
[0034] The multiple health states can be pre-set health states used to measure the expansion force of the target battery. Generally, the multiple health states can be health states within the life cycle of the target battery.
[0035] For example, the terminal inputs the acquired target current or target power to the battery testing equipment for charge and discharge control, and inputs the target temperature to the temperature control equipment for ambient temperature control, so that the target battery performs charge and discharge cycles according to the target current or target power at the target temperature, and measures the expansion force of the target battery in the multiple health states when it reaches the multiple health states preset by the target battery.
[0036] S103, based on multiple health states and corresponding expansion forces, determine the correlation between the target battery's health state and expansion force.
[0037] S104, Based on the correlation, determine the predicted expansion force of the target battery under a specified health condition.
[0038] For example, the terminal acquires the expansion force corresponding to the target battery in multiple health states. Based on the expansion force change data corresponding to each of the multiple health states, the terminal filters the multiple health states to obtain multiple target health states. Then, based on the multiple target health states and their corresponding expansion forces, the correlation between the target battery's health state and expansion force is determined, such as establishing a functional relationship between the target battery's health state and expansion force. The target health states are the health states used to establish the correlation, obtained by filtering based on expansion force change data. Specifically, the target health state can refer to the health state of the target battery in the linear expansion stage during cyclic charging and discharging. Therefore, the correlation between the target battery's corresponding health state and expansion force can refer to a linear relationship between the health state and expansion force.
[0039] Then, based on the correlation between the target battery's health state and its expansion force, the predicted expansion force of the target battery under a specified health state is determined. The specified health state can be the health state of the target battery throughout its entire lifespan, including its health state at the end of its lifespan.
[0040] In this embodiment, by obtaining the target temperature, target current, and / or target power to accelerate the degradation of the target battery's lifespan, and by performing charge-discharge cycles on the target battery based on the target temperature, target current, and / or target power, the battery aging can be accelerated to obtain the expansion force corresponding to the target battery in multiple health states, thereby achieving accelerated expansion of the target battery. Furthermore, based on the multiple health states of the target battery and the corresponding expansion forces, the correlation between the target battery's health states and expansion forces is determined, and this correlation is used to determine the predicted expansion force of the target battery in a specified health state, ensuring the accuracy of the target battery's expansion force prediction.
[0041] In one embodiment, such as Figure 2As shown, based on multiple health states and corresponding expansion forces, the correlation between the target battery's health state and expansion force is determined, including: S201, Based on the difference in expansion force between the expansion forces corresponding to multiple health states, determine multiple target health states among the multiple health states; S202, based on multiple target health states and corresponding expansion forces, determine the correlation between the target battery's health state and expansion force.
[0042] Among them, the target health state refers to the health state of the target battery in the linear expansion stage during the cycle of charge and discharge.
[0043] For example, the terminal collects the expansion force of the target battery under multiple health states, calculates the difference in expansion force between the expansion forces corresponding to the multiple health states, and obtains expansion force change data between the expansion forces corresponding to the multiple health states. Based on the expansion force change data, multiple target health states are determined among the multiple health states. Specifically, according to a preset number, health states whose expansion force change data is less than a preset threshold are determined as the target health states under that preset number.
[0044] Then, based on multiple target health states and corresponding expansion forces, the correlation between the target battery's health state and expansion force is determined.
[0045] In this embodiment, by determining multiple target health states among multiple health states, and by determining the correlation between the target battery's health state and expansion force based on the multiple target health states and the corresponding expansion force, the accuracy of the correlation can be guaranteed, thereby improving the accuracy of the target battery's expansion force prediction.
[0046] In an exemplary embodiment, based on a preset quantity, multiple target health states, and corresponding expansion forces, the correlation between the target battery's health state and expansion force is determined. This correlation is generally a linear function. Specifically, when the preset quantity is less than or equal to a preset quantity threshold, a low-order linear function, such as a linear function, is determined between the target battery's health state and expansion force based on the multiple health states and corresponding expansion forces. When the preset quantity is greater than the preset quantity threshold, a linear fit is performed on the multiple health states and corresponding expansion forces to obtain a high-order linear function, such as an exponential function, between the target battery's health state and expansion force.
[0047] In this embodiment, by determining the correlation between the target battery's health state and expansion force based on a preset number, multiple target health states, and corresponding expansion forces, the prediction flexibility of battery expansion force can be achieved, thereby improving the prediction efficiency and accuracy of battery expansion force.
[0048] In one embodiment, S201, based on the difference in expansion force between the expansion forces corresponding to the multiple health states, multiple target health states are determined among the multiple health states, including: Based on the difference in expansion force between multiple health states, the difference variables corresponding to the multiple health states are determined. In the health states where the difference variable meets the preset variable threshold, multiple target health states are determined.
[0049] For example, the expansion force change data includes difference variables of expansion force differences between multiple health states, which can be obtained by calculating the differences between expansion force differences. Then, among the health states where the difference variables meet preset variable thresholds, multiple target health states are determined. For example, if the target battery has an expansion force of 300 at 100% SOH, 730 at 95% SOH, 1370 at 90% SOH, 2090 at 85% SOH, and 2800 at 80% SOH, then the expansion force difference 1 between 100% SOH and 95% SOH is 430, the expansion force difference 2 between 95% SOH and 90% SOH is 640, the expansion force difference 3 between 90% SOH and 85% SOH is 720, and the expansion force difference 430 between 85% SOH and 80% SOH is 720. The expansion force difference value 4 is 710, while the difference between expansion force difference value 1 and expansion force difference value 2 is 310, which is greater than the preset variable threshold of 100. Therefore, the healthy states of 100% SOH and 95% SOH are not the target healthy states. The difference between expansion force difference value 2 and expansion force difference value 3 is 80, which is less than the preset variable threshold of 100, and the difference between expansion force difference value 3 and expansion force difference value 4 is 10, which is less than the preset variable threshold of 100. Therefore, the healthy states of 90% SOH, 85% SOH, and 80% SOH are the target healthy states. It can be seen that the expansion force corresponding to the target healthy states of 90% SOH, 85% SOH, and 80% SOH shows an increasing trend of approximately 700 increments. This indicates that the expansion force of the target battery in the target healthy states of 90% SOH, 85% SOH, and 80% SOH shows a linear increase, that is, there is a linear relationship between the healthy state and the expansion force. After obtaining multiple target health states and corresponding expansion forces, the terminal establishes a linear function between the target battery's health state and expansion force to predict the target battery's expansion force under a specified health state.
[0050] In this embodiment, by determining multiple target health states based on the difference variables corresponding to multiple health states, the accuracy of multiple target health states can be guaranteed, the accuracy of obtaining the linear function between the target battery's health state and expansion force can be accurately obtained, and thus the accuracy of the target battery's expansion force prediction can be guaranteed.
[0051] In one embodiment, multiple target health states include inflection point health states, specifying that a health state is less than the inflection point health state.
[0052] For example, the multiple target health states include inflection point health states. Inflection point health states represent the health states when the difference variables corresponding to the multiple health states change from being greater than or equal to a preset variable threshold to being less than a preset variable threshold. This can be understood as the health state corresponding to the dividing point where the expansion force of the target battery changes from a nonlinear law to a linear law. For example, the expansion force of the target battery is 300 at 100% SOH, 730 at 95% SOH, 1370 at 90% SOH, and 2090 at 85% SOH. The expansion force difference 1 between 100% SOH and 95% SOH is 430, the expansion force difference 2 between 95% SOH and 90% SOH is 640, and the expansion force difference 3 between 90% SOH and 85% SOH is 720. When the difference between expansion force difference 1 and expansion force difference 2 is 310 and greater than the preset variable threshold of 100, and the difference between expansion force difference 2 and expansion force difference 3 is 80 and less than the preset variable threshold of 100, the healthy state of 90% SOH is determined to be the inflection point healthy state.
[0053] After obtaining the correlation between the target battery's health state and expansion force, the terminal can acquire a specified health state, which is less than the inflection point health state. Specifically, the specified health state is also less than any target health state. Then, based on the correlation between the target battery's health state and expansion force, the terminal determines the predicted expansion force of the target battery in the specified health state.
[0054] In an exemplary embodiment, the terminal can determine multiple target health states corresponding to the target battery based on the inflection point health state corresponding to the target battery. For example, at least one health state lower than the inflection point health state can be determined as multiple target health states corresponding to the target battery, including the inflection point health state. Then, the terminal proceeds to the step of determining the correlation between the target battery's health state and its expansion force based on the multiple target health states and their corresponding expansion forces, until the predicted expansion force of the target battery in a specified health state is obtained.
[0055] In an exemplary embodiment, the terminal can also determine at least two target health states corresponding to the target battery based on the health state interval between the inflection point health state corresponding to the target battery and the specified health state. For multiple target health states and their corresponding expansion forces, the terminal determines the predicted expansion force of the target battery in the specified health state according to a preset linear relationship. For example, if the inflection point health state corresponding to the target battery is 90% and the specified health state is 70%, then at least two target health states can be determined between [90%SOH, 70%SOH]. The target health states also include the inflection point health state. For example, if the preset quantity is 2 and less than the preset quantity threshold of 10, the two target health states corresponding to the target battery are determined to be 90%SOH (abbreviated as S2) and 85%SOH (abbreviated as S3), and the specified health state is 70%SOH (abbreviated as S1). The expansion forces of the target battery at 90%SOH and 85%SOH are obtained as P2 and P3, respectively. The calculation of the predicted expansion force P1 of the target battery in the specified health state S1 is shown in formula (1).
[0056] (1) In this embodiment, the predicted expansion force of the target battery in a specified health state is predicted by determining the correlation between multiple target health states and corresponding expansion forces. Furthermore, since the specified health state is less than the inflection point health state, the prediction accuracy of the expansion force can be guaranteed.
[0057] In one embodiment, such as Figure 3 As shown, the battery expansion force prediction method also includes: S301, Obtain the expansion force and cycle period of the sample battery during charge and discharge cycles at multiple test temperatures and corresponding test charge and discharge parameters; S302, Based on the expansion force of the sample battery during charge-discharge cycles at multiple test temperatures and corresponding test charge-discharge parameters, determine the candidate charge-discharge parameters at multiple test temperatures; S303 determines the target temperature and target charge / discharge parameters based on the cycle period corresponding to the candidate charge / discharge parameters at each test temperature.
[0058] For example, multiple test currents and corresponding test charge / discharge parameters can be determined based on the reference cycle parameters corresponding to the sample battery. The reference cycle parameters can be a MAP table, which defines the boundaries of the maximum charge / discharge current and charge / discharge power that the battery can continuously output / input under different temperatures (T), different states of charge (SoC), and different states of health (SOH). For example, when the sample battery is a lithium battery, the MAP table designed for continuous charge / discharge current or charge / discharge power includes: 25℃ maximum support for 0.7C / 0.7P - 5000 cycles - 70% SOH, 35℃ maximum support for 1.0C / 1.0P - 3500 cycles - 70% SOH, 45℃ maximum support for 1.2C / 1.2P - 2000 cycles - 70% SOH, and 60℃ maximum support for 1.5C / 1.5P - 1000 cycles - 70% SOH. Based on the reference charge-discharge data corresponding to the sample battery, multiple test temperatures are set in advance, such as 25℃, 35℃, 45℃ and 60℃, and multiple test charge-discharge parameters are set for the corresponding test temperatures, such as 25℃: 0.7C / 0.7P, 0.7C, etc.; 35℃: 0.5C / 0.5P, 1.0C / 1.0P, etc.; 45℃: 0.5C / 0.5P, 1.2C / 1.2P, etc.; 60℃: 0.5C / 0.5P, 1.2C / 1.2P, 1.5C / 1.5P, etc.
[0059] The terminal acquires multiple test temperatures and corresponding charge / discharge parameters. For each test temperature and corresponding charge / discharge parameters, the sample battery is subjected to charge / discharge cycles at the same test temperature according to the multiple charge / discharge parameters corresponding to that test temperature. The expansion force of the sample battery under different health states during the charge / discharge cycle at each test current is collected, as well as the cycle period when each health state is reached. Based on the change data of the expansion force of the sample battery during the charge / discharge cycle at the multiple test temperatures and corresponding charge / discharge parameters, candidate charge / discharge parameters at the multiple test temperatures are determined. Then, based on the cycle period corresponding to the candidate charge / discharge parameters at each test temperature, the target temperature and target charge / discharge parameters are determined.
[0060] In this embodiment, by determining candidate charge and discharge parameters based on expansion force change data, and by effectively determining the target temperature and target charge and discharge parameters to accelerate battery life degradation based on cycle period, the optimal stress conditions for accelerating battery aging can be scientifically determined through multi-dimensional test data, ensuring the accuracy of the target temperature and target charge and discharge parameters.
[0061] In one embodiment, such as Figure 4 As shown in S302, based on the expansion force of the sample battery during charge-discharge cycles at multiple test temperatures and corresponding test charge-discharge parameters, candidate charge-discharge parameters at multiple test temperatures are determined, including: S401, for any test temperature and corresponding multiple test charge and discharge parameters, obtain the expansion force of the sample battery during the charge and discharge cycle at the test temperature and corresponding multiple test charge and discharge parameters. S402, based on the expansion force change data between the expansion forces corresponding to multiple test charge and discharge parameters, determine the candidate charge and discharge parameters at the test temperature, thereby obtaining the candidate charge and discharge parameters at multiple test temperatures.
[0062] For example, the terminal acquires the expansion force of the sample battery during the charge-discharge cycle at any test temperature and corresponding multiple test charge-discharge parameters. Specifically, it can acquire the expansion force corresponding to multiple health states of the sample battery during the charge-discharge cycle at the test temperature and corresponding multiple test charge-discharge parameters, and acquire the expansion force change data between the expansion forces of the multiple test charge-discharge parameters in the same health state. The expansion force change data can be obtained by calculating the difference between the expansion forces in the same health state.
[0063] Based on the expansion force variation data corresponding to multiple test charge and discharge parameters, candidate charge and discharge parameters at the test temperature are determined, thereby obtaining candidate charge and discharge parameters at multiple test temperatures.
[0064] In this embodiment, by determining the candidate charge-discharge parameters at the test temperature based on the expansion force change data corresponding to the expansion forces of multiple test charge-discharge parameters, it is possible to ensure the rationality of the battery expansion during cyclic charge-discharge at each test temperature according to the candidate charge-discharge parameters. This can be understood as the expansion force obtained by the battery under different test temperatures and corresponding candidate charge-discharge parameters being normal and consistent with the battery expansion law, thus effectively collecting the battery's expansion force.
[0065] In one embodiment, S402, based on the expansion force change data corresponding to the expansion forces of multiple test charge-discharge parameters, candidate charge-discharge parameters at the test temperature are determined, including: Based on the difference between the expansion forces corresponding to multiple test currents, the expansion force change data is obtained; Test charge-discharge parameters whose expansion force change data is less than the preset expansion force change threshold are determined as candidate charge-discharge parameters at the test temperature.
[0066] For example, the terminal calculates the difference between the expansion forces of multiple test charge-discharge parameters under the same health state, and obtains the expansion force change data of the target battery under the same health state corresponding to the multiple test charge-discharge parameters. When the expansion force change data corresponding to each health state is less than a preset expansion force change threshold, the test charge-discharge parameter corresponding to the expansion force change data is determined as a candidate charge-discharge parameter at the test temperature.
[0067] In an exemplary embodiment, the terminal can generate multiple expansion force curves corresponding to the test charge-discharge parameters based on the expansion force of the sample battery under the test temperature and corresponding multiple test charge-discharge parameters in multiple health states. Then, the terminal compares the curve differences between the expansion force curves corresponding to each test charge-discharge parameter and determines the test charge-discharge parameters with curve differences less than a preset threshold as candidate charge-discharge parameters corresponding to the test temperature.
[0068] In this embodiment, by determining the candidate charge-discharge parameters at the test temperature based on the expansion force change data corresponding to the expansion forces of multiple test charge-discharge parameters, it is possible to ensure the rationality of the battery expansion during cyclic charge-discharge at each test temperature according to the candidate charge-discharge parameters. This can be understood as the expansion force obtained by the battery under different test temperatures and corresponding candidate charge-discharge parameters being normal and consistent with the battery expansion law, thus effectively collecting the battery's expansion force.
[0069] In one embodiment, S303, based on the cycle number corresponding to the candidate charge / discharge parameters at each test temperature, the target temperature and target charge / discharge parameters are determined, including: Based on the cycle periods corresponding to the candidate charge-discharge parameters at multiple test temperatures, the test temperature and the corresponding candidate charge-discharge parameters corresponding to the minimum cycle period are determined as the target temperature and target charge-discharge parameters.
[0070] For example, after determining the candidate charge / discharge parameters corresponding to each test temperature, the terminal determines the test temperature and the corresponding candidate charge / discharge parameters corresponding to the minimum cycle period as the target temperature and target charge / discharge parameters based on the cycle period corresponding to each candidate charge / discharge parameter. For instance, if the cycle period of a sample battery at 60℃ and 1.5C / 1.5P to 70% SOH is 90 days, the cycle period at 45℃ and 1.2C / 1.2P to 70% SOH is 200 days, and the cycle period at 35℃ and 1.0C / 1.P to 70% SOH is 400 days, and 90 days is the minimum cycle period among 90, 200, and 400, then the 60℃ and 1.5C / 1.5P corresponding to 90 days are determined as the target temperature and target charge / discharge parameters.
[0071] In this embodiment, by determining the target temperature and target charge / discharge parameters based on the cycle period, among the test temperature and corresponding candidate charge / discharge parameters, the optimal cycle conditions for accelerated battery aging can be guaranteed, thereby realizing the accelerated expansion force test of the battery and improving the expansion force prediction efficiency of the target battery.
[0072] In an exemplary embodiment, under conditions where the temperature and charge / discharge current / power conform to the lithium battery design's continuous charge / discharge current / power MAP table or usage specifications (e.g., maximum support of 0.7C / 0.7P at 25°C for 5000 cycles at 70% SOH, maximum support of 1.0C / 1.0P at 35°C for 3500 cycles at 70% SOH, maximum support of 1.2C / 1.2P at 45°C for 2000 cycles at 70% SOH, and maximum support of 1.5C / 1.5P at 60°C for 1000 cycles at 70% SOH), different temperatures and rate cycles only affect the lithium battery's cycle life and do not affect the expansion force at the same SOH state. The main reason is that under different acceleration conditions, the degree of material structure damage, SEI film thickness, and electrolyte consumption of lithium-ion batteries at the same SOH are not significantly different. Therefore, the expansion force of lithium-ion batteries is basically the same when the SOH state is the same.
[0073] Based on this, taking lithium iron phosphate batteries as an example, conventional cycling conditions (such as 25℃, 0.5C / 0.5P) are set as a comparative example, and implementation examples with different cycling acceleration conditions are set, such as increasing the cycling temperature and rate to make the battery quickly reach 70% SOH, thereby accelerating the testing of expansion force throughout the entire life cycle. The specific implementation is as follows: Comparative Example 1 Cyclic testing: Under 25℃ conditions, the lithium iron phosphate battery was subjected to a 0.5C cycle test, with a voltage range of 2.5-3.65V; the initial preload was 300kgf, and a pressure sensor was added to monitor the expansion force changes throughout the entire life cycle during the cycle. First, it was charged at 0.5C constant current and constant voltage to 3.65V, then stopped at 0.05C, and allowed to stand for 30 minutes; then it was discharged at 0.5C constant current to 2.5V, and allowed to stand for 30 minutes; then the next cycle was performed until the discharge capacity decayed to 70% SOH of the rated capacity (5000 cycles, test period approximately 1000 days).
[0074] Example 1 Cyclic testing: Under 25℃ conditions, the lithium iron phosphate battery was subjected to a 0.7C cycle test, with a voltage range of 2.5-3.65V; the initial preload was 300kgf, and a pressure sensor was added to monitor the expansion force changes throughout the entire life cycle. First, the battery was charged at a constant current and constant voltage of 0.7C to 3.65V, then stopped at 0.05C, and allowed to rest for 30 minutes; then it was discharged at a constant current of 0.7C to 2.5V, and allowed to rest for 30 minutes; then the next cycle was performed until the discharge capacity decayed to 70% of the rated capacity at SOH (5000 cycles, test period approximately 750 days).
[0075] Example 2 Cyclic testing: Under 25℃ conditions, the lithium iron phosphate battery was subjected to a 1.0C cycle test, with a voltage range of 2.5-3.65V; the initial preload was 300kgf, and a pressure sensor was added to monitor the expansion force changes throughout the entire life cycle during the cycle. First, it was charged at 1.0C constant current and constant voltage to 3.65V, cut off at 0.05C, and allowed to stand for 30 minutes; then it was discharged at 1.0C constant current to 2.5V cutoff, and allowed to stand for 30 minutes; then the next cycle was performed until the discharge capacity decayed to 70% SOH of the rated capacity (3000 cycles, test period approximately 350 days).
[0076] Example 3 Cyclic testing: The lithium iron phosphate battery was subjected to a 0.5C cycle test at 35℃, with a voltage range of 2.5-3.65V. The initial preload was 300kgf, and a pressure sensor was added to monitor the expansion force changes throughout the entire life cycle. First, the battery was charged at a constant current and constant voltage of 0.5C to 3.65V, then stopped at 0.05C and allowed to stand for 30 minutes. Next, it was discharged at a constant current of 0.5C to 2.5V and allowed to stand for 30 minutes. Then, the next cycle was performed until the discharge capacity decayed to 70% of the rated capacity at sea level (SOH) (3500 cycles, approximately 700 days).
[0077] Example 4 Cyclic testing: The lithium iron phosphate battery was subjected to a 0.5C cycle test at 45℃, with a voltage range of 2.5-3.65V. The initial preload was 300kgf, and a pressure sensor was added to monitor the expansion force changes throughout the entire life cycle. The battery was first charged at a constant current and constant voltage of 0.5C to 3.65V, then stopped at 0.05C and allowed to stand for 30 minutes. Next, it was discharged at a constant current of 0.5C to 2.5V and allowed to stand for 30 minutes. This process was repeated until the discharge capacity decayed to 70% of the rated capacity at sea level (SOH) (2000 cycles, approximately 375 days).
[0078] Example 5 Cyclic testing: The lithium iron phosphate battery was subjected to a 0.5C cycle test at 60℃, with a voltage range of 2.5-3.65V. The initial preload was 300kgf, and a pressure sensor was added to monitor the expansion force changes throughout the entire life cycle. First, the battery was charged at a constant current and constant voltage of 0.5C to 3.65V, then stopped at 0.05C and allowed to stand for 30 minutes. Next, it was discharged at a constant current of 0.5C to 2.5V and allowed to stand for 30 minutes. Then, the next cycle was performed until the discharge capacity decayed to 70% of the rated capacity at sea level (SOH) (1000 cycles, test period approximately 180 days).
[0079] Example 6 Cyclic testing: The lithium iron phosphate battery was subjected to a 1.0C cycle test at 35℃, with a voltage range of 2.5-3.65V. The initial preload was 300kgf, and a pressure sensor was added to monitor the expansion force changes throughout the entire life cycle. First, the battery was charged at a constant current and constant voltage of 1.0C to 3.65V, then stopped at 0.05C and allowed to stand for 30 minutes. Next, it was discharged at a constant current of 1.0C to 2.5V and allowed to stand for 30 minutes. Then, the next cycle was performed until the discharge capacity decayed to 70% of the rated capacity at sea level (SOH) (3500 cycles, approximately 400 days).
[0080] Example 7 Cyclic testing: The lithium iron phosphate battery was subjected to a 1.2C cycle test at 45℃, with a voltage range of 2.5-3.65V. The initial preload was 300kgf, and a pressure sensor was added to monitor the expansion force changes throughout the entire life cycle. First, the battery was charged at a constant current and constant voltage of 1.2C to 3.65V, then stopped at 0.05C and allowed to stand for 30 minutes. Next, it was discharged at a constant current of 1.2C to 2.5V and allowed to stand for 30 minutes. Then, the next cycle was performed until the discharge capacity decayed to 70% of the rated capacity at sea level (SOH) (2000 cycles, approximately 200 days).
[0081] Example 8 Cyclic testing: The lithium iron phosphate battery was subjected to a 1.5C cycle test at 60℃, with a voltage range of 2.5-3.65V. The initial preload was 300kgf, and a pressure sensor was added to monitor the expansion force changes throughout the entire life cycle. First, the battery was charged at a constant current and constant voltage of 1.5C to 3.65V, then stopped at 0.05C and allowed to stand for 30 minutes. Next, it was discharged at a constant current of 1.5C to 2.5V and allowed to stand for 30 minutes. Then, the next cycle was performed until the discharge capacity decayed to 70% of the rated capacity at sea level (SOH) (1000 cycles, test period approximately 90 days).
[0082] Comparative Example 2 Cyclic testing: Under 25℃ conditions, the lithium iron phosphate battery was subjected to a 0.5P cycle test, with a voltage range of 2.5-3.65V; the initial preload was 300kgf, and a pressure sensor was added to monitor the expansion force changes throughout the entire life cycle during the cycle. First, it was charged at a constant power of 0.5P to the cutoff voltage of 3.65V and then allowed to stand for 30 minutes; then it was discharged at a constant power of 0.5P to the cutoff voltage of 2.5V and allowed to stand for 30 minutes; then the next cycle was performed until the discharge capacity decayed to 70% SOH of the rated capacity (5000 cycles, test period of approximately 1000 days).
[0083] Example 9 Cyclic testing: Under 25℃ conditions, the lithium iron phosphate battery was subjected to a 0.7P cycle test, with a voltage range of 2.5-3.65V; the initial preload was 300kgf, and a pressure sensor was added to monitor the expansion force changes throughout the entire life cycle during the cycle. First, it was charged at a constant power of 0.7P to the cutoff voltage of 3.65V and then allowed to rest for 30 minutes; then it was discharged at a constant power of 0.7P to the cutoff voltage of 2.5V and allowed to rest for 30 minutes; then the next cycle was performed until the discharge capacity decayed to 70% SOH of the rated capacity (5000 cycles, test period approximately 750 days).
[0084] Example 10 Cyclic testing: Under 25℃ conditions, the lithium iron phosphate battery was subjected to a 1.0P cycle test, with a voltage range of 2.5-3.65V; the initial preload was 300kgf, and a pressure sensor was added to monitor the expansion force changes throughout the entire life cycle during the cycle. First, it was charged at a constant power of 1.0P to the cutoff voltage of 3.65V and then allowed to stand for 30 minutes; then it was discharged at a constant power of 1.0P to the cutoff voltage of 2.5V and allowed to stand for 30 minutes; then the next cycle was performed until the discharge capacity decayed to 70% SOH of the rated capacity (3000 cycles, test period approximately 350 days).
[0085] Example 11 Cyclic testing: The lithium iron phosphate battery was subjected to a 0.5P cycle test at 35℃, with a voltage range of 2.5-3.65V. The initial preload was 300kgf, and a pressure sensor was added to monitor the expansion force changes throughout the entire life cycle. First, the battery was charged at a constant power of 0.5P until the cutoff voltage of 3.65V, then allowed to rest for 30 minutes; then it was discharged at a constant power of 0.5P until the cutoff voltage of 2.5V, and allowed to rest for 30 minutes; then the next cycle was performed until the discharge capacity decayed to 70% of the rated capacity at sea level (SOH) (3500 cycles, test period approximately 700 days).
[0086] Example 12 Cyclic testing: The lithium iron phosphate battery was subjected to a 0.5P cycle test at 45℃, with a voltage range of 2.5-3.65V. The initial preload was 300kgf, and a pressure sensor was added to monitor the expansion force changes throughout the entire life cycle. The battery was first charged at a constant power of 0.5P to the 3.65V cutoff, then allowed to rest for 30 minutes; then discharged at a constant power of 0.5P to the 2.5V cutoff, and allowed to rest for 30 minutes; then the next cycle was performed until the discharge capacity decayed to 70% of the rated capacity at sea level (SOH) (2000 cycles, test period approximately 375 days).
[0087] Example 13 Cyclic testing: The lithium iron phosphate battery was subjected to a 0.5P cycle test at 60℃, with a voltage range of 2.5-3.65V. The initial preload was 300kgf, and a pressure sensor was added to monitor the expansion force changes throughout the entire life cycle. First, the battery was charged at a constant power of 0.5P until the cutoff voltage of 3.65V, then allowed to rest for 30 minutes; then it was discharged at a constant power of 0.5P until the cutoff voltage of 2.5V, and allowed to rest for 30 minutes; then the next cycle was performed until the discharge capacity decayed to 70% of the rated capacity at sea level (SOH) (1000 cycles, test period approximately 180 days).
[0088] Example 14 Cyclic testing: The lithium iron phosphate battery was subjected to a 1.0P cycle test at 35℃, with a voltage range of 2.5-3.65V. The initial preload was 300kgf, and a pressure sensor was added to monitor the expansion force changes throughout the entire life cycle. First, the battery was charged at a constant power of 1.0P to the 3.65V cutoff, and then allowed to rest for 30 minutes. Next, it was discharged at a constant power of 1.0P to the 2.5V cutoff, and allowed to rest for 30 minutes. Then, the next cycle was performed until the discharge capacity decayed to 70% of the rated capacity at sea level (SOH) (3500 cycles, approximately 400 days).
[0089] Example 15 Cyclic testing: The lithium iron phosphate battery was subjected to a 1.2P cycle test at 45℃, with a voltage range of 2.5-3.65V. The initial preload was 300kgf, and a pressure sensor was added to monitor the expansion force changes throughout the entire life cycle. The battery was first charged at a constant power of 1.2P to the 3.65V cutoff, then allowed to rest for 30 minutes; then discharged at a constant power of 1.2P to the 2.5V cutoff, and allowed to rest for 30 minutes; then the next cycle was performed until the discharge capacity decayed to 70% SOH of the rated capacity (2000 cycles, approximately 200 days).
[0090] Example 16 Cyclic testing: The lithium iron phosphate battery was subjected to a 1.5P cycle test at 60℃, with a voltage range of 2.5-3.65V. The initial preload was 300kgf, and a pressure sensor was added to monitor the expansion force changes throughout the entire life cycle. First, the battery was charged at a constant power of 1.5P until the cutoff voltage of 3.65V, then allowed to rest for 30 minutes; then it was discharged at a constant power of 1.5P until the cutoff voltage of 2.5V, and allowed to rest for 30 minutes; then the next cycle was performed until the discharge capacity decayed to 70% of the rated capacity at sea level (SOH) (1000 cycles, test period approximately 90 days).
[0091] The changes in expansion force under different cyclic test conditions are shown in Table 1.
[0092] Table 1
[0093] As shown in Table 1, through Examples 1 and 2 and Comparative Example 1, it can be found that under the same temperature condition of 25°C, when the current rate is within a reasonable range (0.5C-0.7C), the expansion force of the battery at the same SOH node (100% SOH to 70% SOH) is basically consistent, with a maximum deviation of no more than 1%, which is within a reasonable error range. As the current rate increases from 0.5C to 0.7C, the test cycle is shortened from 1000 days to 750 days. However, when the current rate is further increased to 1.0C (exceeding the reasonable current range designed for the battery at this temperature), although the test cycle is shortened to 350 days, the expansion force increases abnormally from 95% SOH, and at 70% SOH it is already 60% higher than the benchmark value of 4100 kgf. Therefore, reasonably increasing the current rate can accelerate the test cycle, but blindly increasing the current rate will cause abnormal reactions and lead to distortion of the expansion force test.
[0094] Through Examples 3, 4, and 5 and Comparative Example 1, it can be observed that under the same current rate of 0.5C, regardless of whether the temperature is increased from 25°C to 35°C, 45°C, or 60°C, the expansion force of the battery at each of the same SOH nodes (100% SOH to 70% SOH) is basically consistent, with a maximum deviation of no more than 2%, which is within a reasonable error range. As the temperature gradually increases, the test cycle shows a significant shortening trend: the test cycle is 1000 days at 25°C, shortened to 700 days at 35°C, further compressed to 375 days at 45°C, and only 180 days are needed to complete the full life cycle expansion force test at 60°C. Therefore, reasonably increasing the temperature can accelerate the test cycle.
[0095] Through Examples 6, 7, and 8 and Comparative Example 1, it can be observed that when temperature and current rate are synergistically increased and both conform to the continuous charge / discharge current / power MAP table or usage specifications for lithium iron phosphate batteries, the expansion force of the battery at each of the same SOH nodes (100% SOH to 70% SOH) is basically consistent, with a maximum deviation of no more than 5%. Moreover, the acceleration effect is significantly better than that of a single variable, rate increase or temperature increase: the test cycle of the baseline group (25℃ 0.5C) is 1000 days, while the combination of 35℃ and 1.0C shortens the cycle to 400 days, the combination of 45℃ and 1.2C is further compressed to 200 days, and the combination of 60℃ and 1.5C can complete the test in only 90 days.
[0096] Through Examples 9 and 10 and Comparative Example 2, it can be observed that under the same temperature condition of 25°C, when the power rate is within a reasonable range (0.5P-0.7P), the expansion force of the battery at the same SOH node (100% SOH to 70% SOH) is basically consistent, with a maximum deviation of no more than 1%, which is within a reasonable error range. As the power rate increases from 0.5P to 0.7P, the test cycle is shortened from 1000 days to 750 days. However, when the power rate is further increased to 1.0P (exceeding the reasonable power range designed for the battery at this temperature), although the test cycle is shortened to 350 days, the expansion force increases abnormally from 95% SOH, and at 70% SOH it is already 60% higher than the benchmark value of 4086 kgf. Therefore, reasonably increasing the power rate can accelerate the test cycle, but blindly increasing the power rate will cause abnormal reactions and lead to distortion of the expansion force test.
[0097] Through Examples 11, 12, and 13 and Comparative Example 2, it can be observed that under the same power rate of 0.5P, regardless of whether the temperature is increased from 25°C to 35°C, 45°C, or 60°C, the expansion force of the battery at each of the same SOH nodes (100% SOH to 70% SOH) is basically consistent, with a maximum deviation of no more than 3%, which is within a reasonable error range. As the temperature gradually increases, the test cycle shows a significant shortening trend: the test cycle is 1000 days at 25°C, shortened to 700 days at 35°C, further compressed to 375 days at 45°C, and only 180 days are needed to complete the full life cycle expansion force test at 60°C. Therefore, reasonably increasing the temperature can accelerate the test cycle.
[0098] Through Examples 14, 15, 16 and Comparative Example 2, it can be found that when temperature and power rate are synergistically increased and both meet the continuous charge / discharge current / power MAP or usage specifications of lithium iron phosphate batteries, the expansion force of the battery at each of the same SOH nodes (100% SOH to 70% SOH) is basically consistent, with a maximum deviation of no more than 5%. Moreover, the acceleration effect is significantly better than single variable power or temperature increase: the test cycle of the baseline group (25℃ 0.5P) is 1000 days, while the 35℃ and 1.0P combination shortens the cycle to 400 days, the 45℃ and 1.2P combination is further compressed to 200 days, and the 60℃ and 1.5P combination can complete the test in only 90 days.
[0099] In summary, whether the temperature is increased alone, the current rate / power is increased alone, or both are optimized synergistically, as long as the test conditions meet the continuous charge / discharge current / power MAP table or usage specifications for lithium iron phosphate batteries, and no abnormalities such as interface lithium plating or electrolyte side reactions occur, the expansion force of the battery at the same SOH node will be basically consistent, with an error of no more than 5%. Therefore, the test cycle can be shortened by reasonably increasing the temperature and current rate / power.
[0100] On the other hand, this embodiment provides a battery expansion force prediction device. Figure 4 This is a schematic diagram of a battery expansion force prediction device according to an embodiment of this application, as shown below. Figure 4 As shown, the battery expansion force prediction device 400 includes: a data acquisition module 401, an accelerated expansion module 402, a relationship establishment module 403, and a prediction module 404. The device will be described below.
[0101] Data acquisition module 401 is used to acquire the target temperature and target charge / discharge parameters that accelerate the degradation of the target battery life; The accelerated expansion module 402 is used to perform charge-discharge cycles on the target battery based on the target temperature and target charge-discharge parameters, and obtain the expansion force of the target battery under multiple health states. The relationship establishment module 403 is used to determine the correlation between the target battery's health state and expansion force based on multiple health states and corresponding expansion forces. The prediction module 404 is used to determine the predicted expansion force of the target battery under a specified health state based on the correlation relationship.
[0102] In one embodiment, the relationship establishment module 403 is further configured to determine multiple target health states among multiple health states based on the difference in expansion force between the expansion forces corresponding to the multiple health states; and to determine the correlation between the target battery and the expansion force based on the multiple target health states and the corresponding expansion forces.
[0103] In one embodiment, the relationship establishment module 403 is further configured to determine the difference variables corresponding to the multiple health states based on the difference in expansion forces between the expansion forces corresponding to the multiple health states; and to determine multiple target health states among the health states in which the difference variables satisfy a preset variable threshold.
[0104] In one embodiment, multiple target health states include inflection point health states, specifying that a health state is less than the inflection point health state.
[0105] In one embodiment, the battery expansion force prediction device 400 is further configured to acquire the expansion force and cycle period of the sample battery during charge-discharge cycles at multiple test temperatures and corresponding test charge-discharge parameters; determine candidate charge-discharge parameters at multiple test temperatures based on the expansion force of the sample battery during charge-discharge cycles at multiple test temperatures and corresponding test charge-discharge parameters; and determine the target temperature and target charge-discharge parameters based on the cycle period corresponding to the candidate charge-discharge parameters at each test temperature.
[0106] In one embodiment, the battery expansion force prediction device 400 is further configured to acquire the expansion force of the sample battery during the charge-discharge cycle at any test temperature and corresponding multiple test charge-discharge parameters; and determine candidate charge-discharge parameters at the test temperature based on the expansion force change data between the expansion forces corresponding to the multiple test charge-discharge parameters, thereby obtaining candidate charge-discharge parameters at multiple test temperatures.
[0107] In one embodiment, the battery expansion force prediction device 400 is further configured to obtain expansion force change data based on the difference between the expansion forces corresponding to multiple test currents; and to determine the test charge-discharge parameters whose expansion force change data is less than a preset expansion force change threshold as candidate charge-discharge parameters at the test temperature.
[0108] In one embodiment, the battery expansion force prediction device 400 is further configured to determine the test temperature corresponding to the minimum cycle period and the corresponding candidate charge-discharge parameters as the target temperature and target charge-discharge parameters based on the cycle periods corresponding to the candidate charge-discharge parameters at multiple test temperatures.
[0109] Each module in the battery expansion force prediction device of the aforementioned energy storage equipment can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.
[0110] Thirdly, this embodiment provides an electronic device, including a memory and a processor. The memory stores computer instructions, and when the computer instructions are executed by the processor, they implement the method of any of the above embodiments.
[0111] In one embodiment, this embodiment also provides an electronic device, which may be a server, and its internal structure diagram may be as follows. Figure 5 As shown, this electronic device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer instructions, and a database. The internal memory provides an environment for the operation of the operating system and computer instructions stored in the non-volatile storage media. The database stores data involved in business data processing methods. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communicating with external terminals via a network connection. When the computer instructions are executed by the processor, a communication configuration method for an energy storage device is implemented.
[0112] Those skilled in the art will understand that Figure 5 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.
[0113] Fourthly, embodiments of this application provide a computer-readable storage medium storing computer instructions thereon, which are loaded by a processor to execute the arrangements in any of the methods described above. In embodiments of this application, the storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM), etc.
[0114] Fifthly, embodiments of this application provide a computer program product, including a computer program or instructions, which are executed by a processor to implement the steps of any of the methods described above.
[0115] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.
[0116] The battery screening method, electronic device, and computer-readable storage medium provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A method for predicting battery expansion force, characterized in that, Includes the following steps: Obtain the target temperature and target charge / discharge parameters that accelerate the degradation of the target battery's lifespan; Based on the target temperature and the target charge / discharge parameters, the target battery is subjected to charge / discharge cycles to obtain the expansion force of the target battery under multiple healthy states; Based on multiple health states and corresponding expansion forces, the correlation between the health state and expansion force of the target battery is determined. Based on the aforementioned correlation, the predicted expansion force of the target battery under a specified health condition is determined.
2. The method according to claim 1, characterized in that, The process of determining the correlation between the target battery's health state and expansion force based on multiple health states and corresponding expansion forces includes: Based on the difference in expansion force between the expansion forces corresponding to the multiple health states, multiple target health states are determined among the multiple health states; Based on multiple target health states and corresponding expansion forces, the correlation between the target battery's health state and expansion force is determined.
3. The method according to claim 2, characterized in that, The step of determining multiple target health states among the multiple health states based on the expansion force difference between the expansion forces corresponding to the multiple health states includes: Based on the difference in expansion force between the expansion forces corresponding to the multiple health states, the difference variables corresponding to the multiple health states are determined. Among the health states where the difference variable meets the preset variable threshold, multiple target health states are determined.
4. The method according to claim 2, characterized in that, The plurality of target health states include inflection point health states, and the specified health state is less than the inflection point health state.
5. The method according to claim 1, characterized in that, The method further includes: The expansion force and cycle period of the sample battery during charge and discharge cycles were obtained under multiple test temperatures and corresponding test charge and discharge parameters. Based on the expansion force of the sample battery during charge-discharge cycles at multiple test temperatures and corresponding test charge-discharge parameters, candidate charge-discharge parameters at multiple test temperatures are determined. The target temperature and target charge / discharge parameters are determined based on the cycle period corresponding to the candidate charge / discharge parameters at each test temperature.
6. The method according to claim 5, characterized in that, The step of determining candidate charge-discharge parameters at multiple test temperatures based on the expansion force of the sample battery during charge-discharge cycles at multiple test temperatures and corresponding test charge-discharge parameters includes: For any of the test temperatures and corresponding multiple test charge-discharge parameters, obtain the expansion force of the sample battery during the charge-discharge cycle at the test temperature and corresponding multiple test charge-discharge parameters; Based on the expansion force change data corresponding to the expansion forces of the multiple test charge and discharge parameters, candidate charge and discharge parameters at the test temperature are determined, thereby obtaining multiple candidate charge and discharge parameters at the test temperature.
7. The method according to claim 6, characterized in that, The step of determining candidate charge / discharge parameters at the test temperature based on the expansion force variation data corresponding to the expansion forces of multiple test charge / discharge parameters includes: Based on the differences between the expansion forces corresponding to the various test charge and discharge parameters, expansion force change data is obtained; Test charge-discharge parameters whose expansion force change data is less than a preset expansion force change threshold are determined as candidate charge-discharge parameters at the test temperature.
8. The method according to claim 5, characterized in that, The determination of the target temperature and target charge / discharge parameters based on the cycle period corresponding to the candidate charge / discharge parameters at each of the test temperatures includes: Based on the cycle periods corresponding to the candidate charge-discharge parameters at multiple test temperatures, the test temperature and the corresponding candidate charge-discharge parameters corresponding to the minimum cycle period are determined as the target temperature and target charge-discharge parameters.
9. An electronic device, characterized in that, The electronic device includes a processor and a memory, the memory storing a computer program configured to be executed by the processor to implement the steps of the method according to any one of claims 1 to 8.
10. A computer storage medium, characterized in that, The computer storage medium stores a computer program configured to be executed by a processor to implement the steps of the method according to any one of claims 1 to 8.