Method and device for predicting battery life attenuation curve, equipment, storage medium and program product

Abstract

The invention relates to the technical field of batteries, and discloses a battery life attenuation curve prediction method and device, equipment, a storage medium and a program product. The method comprises the following steps: determining each life attenuation stage of a battery based on battery parameters of the battery; respectively determining performance parameters of the battery at a demarcation point of adjacent stages in each life attenuation stage; and generating a life attenuation curve of the battery based on the cycle test data of the battery in a first stage and the performance parameters of the battery at each demarcation point, the first stage being any one of the life attenuation stages. According to the method, before the life attenuation curve is predicted, the life attenuation stages of the battery and the performance parameters at the demarcation points of the adjacent stages are determined, and on this basis, the life attenuation curve of the whole life cycle of the battery can be predicted based on the cycle test data of any life attenuation stage; the workload of loop testing and the required loop testing data volume are reduced, and the efficiency and accuracy of life prediction are improved.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and in particular, to a method, device, equipment, storage medium, and program product for predicting the battery life attenuation curve. Background Art

[0002] During the use of lithium batteries, their performance shows a certain degree of attenuation as the number of charge-discharge cycles increases. By fitting the battery life attenuation curve of lithium batteries, it is helpful to accurately grasp the life characteristics of lithium batteries, reasonably use lithium batteries, extend their service life, improve the safety of battery use, and timely replace batteries with poor health conditions.

[0003] In related technologies, the measured data during the battery charge-discharge cycle is usually measured, and the battery life attenuation curve is fitted based on the measured data. However, since there are obvious differences in the life attenuation characteristics of the battery in different usage stages of the entire life cycle, and the accuracy of the fitted battery life attenuation curve depends on the richness of the collected data, related technologies need to collect the measured data of different usage stages of the entire life cycle of the battery. The amount of data to be collected is large, the cost is high, and the accuracy of the fitted battery life attenuation curve is not good.

[0004] The above statements are only used to provide background technical information related to the present application, and do not necessarily constitute prior art. Summary of the Invention

[0005] In view of the technical problems in the related art that fitting the battery life attenuation curve requires collecting a large amount of measured data, high cost, and poor accuracy. The present application provides a method, device, equipment, storage medium, and program product for predicting the battery life attenuation curve. Only by collecting the cycle test data of any life attenuation stage of the battery can the prediction of the life attenuation curve be carried out, greatly reducing the amount of data collection, reducing the cost, and improving the accuracy of life prediction.

[0006] In the first aspect of the embodiments of the present application, a method for predicting the battery life attenuation curve is provided, including: Based on the battery parameters of the battery, determine each life attenuation stage of the battery; Respectively determine the performance parameters of the battery at the demarcation points between adjacent stages in each life attenuation stage; Based on the cycle test data of the battery in the first stage and the performance parameters at each demarcation point, generate the life attenuation curve of the battery, where the first stage is any stage in each life attenuation stage.

[0007] Based on the battery parameters of the battery itself, the actual life attenuation stages of the battery are automatically determined. For the division of the life attenuation stages of the battery to be predicted, it is more in line with the actual situation of the battery, and the accuracy is very high. By using the cycle test data of any life attenuation stage of the battery and the performance parameters at the demarcation point between any two adjacent stages, the life attenuation curve of the battery can be obtained. The amount of measured data required in the whole prediction process is very small, which can reduce a large amount of actual test time, improve the battery life prediction efficiency, and at the same time reduce the cost caused by actual tests. During the process of predicting the life attenuation curve of the battery, the actual life attenuation stages of the battery are divided and the performance parameters at the demarcation point between any two adjacent stages are determined. Therefore, the life attenuation curve finally obtained includes the life attenuation conditions of each life attenuation stage of the battery, realizing the staged description of the life attenuation curve of the battery, reducing the dependence of the accuracy of the life attenuation curve on the measured data, and effectively improving the accuracy of the life attenuation curve.

[0008] In some embodiments of the present application, determining the life attenuation stages of the battery based on the battery parameters of the battery includes: Determining the life attenuation stages of the battery based on the initial electrolyte filling amount and / or the performance lower limit threshold included in the battery parameters; Wherein, the performance lower limit threshold is used to characterize that the battery stops being used when the performance parameters of the battery reach the performance lower limit threshold.

[0009] The size of the initial electrolyte filling amount has an important impact on the attenuation of battery performance. Determining the life attenuation stages of the battery based on the initial electrolyte filling amount fully considers the influence of the initial electrolyte filling amount on the battery life attenuation, and the determined life attenuation stages are closer to the actual situation of the battery, improving the accuracy of determining the life attenuation stages. The performance lower limit threshold affects the determination of the life attenuation stages in the later stage of battery use. Determining the life attenuation stages of the battery based on the performance lower limit threshold can improve the accuracy of determining the life attenuation stages in the later stage of battery use. Combining the initial electrolyte filling amount and the performance lower limit threshold to determine the life attenuation curves of the battery not only considers the influence of the initial electrolyte filling amount on the performance attenuation during the whole life cycle of the battery, but also considers the influence of the performance lower limit threshold on the life attenuation stages in the later stage of battery use, with more comprehensive consideration factors, making the accuracy of the determined life attenuation stages of the battery higher.

[0010] In some embodiments of the present application, determining the life attenuation stages of the battery based on the initial electrolyte filling amount includes: Based on the initial electrolyte filling amount and the preset electrolyte consumption rate of the battery, determining the target number of cycles required for the initial electrolyte filling amount to be consumed completely; Based on the target number of cycles, determine each life attenuation stage included in the battery.

[0011] By using the initial electrolyte filling amount of the battery and the preset electrolyte consumption rate, estimate the target number of cycles experienced by the battery when the electrolyte dries up. Based on this target number of cycles, determine each life attenuation stage included in the battery, fully considering the influence of electrolyte dry-up on the life attenuation stage of the battery during the entire life cycle of the battery, and being able to accurately determine each actual life attenuation stage included in the battery.

[0012] In some embodiments of the present application, the determining each life attenuation stage included in the battery based on the target number of cycles includes: If the target number of cycles is less than or equal to the first number of cycles required for the battery to reach the starting point of the linear attenuation stage, determine that the battery includes an initial rapid attenuation stage, a mid-term slow attenuation stage, and a final accelerated attenuation stage; If the target number of cycles is greater than the first number of cycles and less than or equal to the second number of cycles required for the battery to reach the end point of the linear attenuation stage, determine that the battery includes the initial rapid attenuation stage, the mid-term slow attenuation stage, a linear attenuation stage, and a final accelerated attenuation stage; If the target number of cycles is greater than the number of cycles corresponding to the performance lower limit threshold, determine that the battery includes the initial rapid attenuation stage, the mid-term slow attenuation stage, and the linear attenuation stage.

[0013] By using the initial electrolyte filling amount of the battery and the preset electrolyte consumption rate, estimate the target number of cycles experienced by the battery when the electrolyte dries up. Based on the comparison of the target number of cycles with the first number of cycles at the starting point of the battery reaching the linear attenuation stage, the second number of cycles at the end point of the linear attenuation stage, and the number of cycles corresponding to the battery reaching the performance lower limit threshold, through simple numerical size comparison, each actual life attenuation stage included in the battery can be determined. In this way, fully considering the influence of electrolyte dry-up in different stages of the entire life cycle of the battery on the life attenuation stage of the battery, each actual life attenuation stage included in the battery can be accurately determined. Compared with the related art that can only know which life attenuation stages the battery includes after fitting a life attenuation curve based on a large number of measured data in the entire life cycle, the embodiments of the present application can, before obtaining the life attenuation curve, pre-determine each life attenuation stage included in the battery based on the initial electrolyte filling amount of the battery, and then use each life attenuation stage included in the battery to assist in predicting the life attenuation curve of the battery, providing a solution for predicting the life attenuation curve that is substantially different from the related art. And since the life attenuation stage of the battery is known before prediction, it also helps to improve the accuracy of predicting the life attenuation curve.

[0014] In some embodiments of the present application, determining each life attenuation stage of the battery based on the lower limit threshold of performance includes: Based on the lower limit threshold of performance being less than or equal to the performance parameter at the starting point when the battery enters the linear attenuation stage, determining that the battery includes an initial rapid attenuation stage and a medium-term slow attenuation stage; Based on the lower limit threshold of performance being greater than the performance parameter at the starting point and less than or equal to the performance parameter at the ending point of the linear attenuation stage, determining that the battery includes the initial rapid attenuation stage, the medium-term slow attenuation stage, and the linear attenuation stage; Based on the lower limit threshold of performance being greater than the performance parameter at the ending point, determining that the battery includes the initial rapid attenuation stage, the medium-term slow attenuation stage, the linear attenuation stage, and a final accelerated attenuation stage.

[0015] The above embodiments fully consider the influence of the lower limit threshold of the battery's performance on the battery's life attenuation stage, can accurately determine each life attenuation stage actually included in the battery, can pre-determine each life attenuation stage included in the battery based on the lower limit threshold of the battery's performance before obtaining the life attenuation curve, and then use each life attenuation stage included in the battery to assist in predicting the battery's life attenuation curve. Since the life attenuation stage of the battery is known before prediction, it helps to improve the accuracy of predicting the life attenuation curve.

[0016] In some embodiments of the present application, determining each life attenuation stage of the battery based on the initial electrolyte filling amount and the lower limit threshold of performance includes: Determining each life attenuation stage of the battery based on a first stage combination of each life attenuation stage determined based on the initial electrolyte filling amount and a second stage combination of each life attenuation stage determined based on the lower limit threshold of performance.

[0017] Comprehensively considering the first stage combination and the second stage combination to determine each life attenuation stage of the battery. In this way, the influence of the electrolyte and the lower limit threshold of performance on the battery's life attenuation stage is comprehensively considered, which can effectively improve the accuracy of the finally determined life attenuation stage, and further helps to improve the accuracy of subsequent life attenuation curve prediction.

[0018] In some embodiments of the present application, the determining each life attenuation stage of the battery based on the battery parameters of the battery includes: Based on the battery model included in the battery parameters, obtaining each life attenuation stage of the battery from a first mapping relationship between the battery model and the life attenuation stage stored in advance; Among them, the first mapping relationship is determined based on the initial electrolyte filling amount corresponding to the battery model and / or the performance lower limit threshold, and the performance lower limit threshold is used to characterize that the battery stops being used when the performance parameters of the battery of the battery model reach the performance lower limit threshold.

[0019] After the first mapping relationship is pre-configured, when it is necessary to predict the life attenuation curve of the battery to be predicted, it is only necessary to query the corresponding life attenuation stage from the first mapping relationship based on the battery model of the battery, which can shorten the time consumed to determine each life attenuation stage included in the battery and improve the processing efficiency. And the first mapping relationship is determined based on the initial electrolyte filling amount corresponding to the battery model and / or the performance lower limit threshold, fully considering the influence of the electrolyte and / or the performance lower limit threshold on the battery life attenuation, and improving the accuracy of determining the life attenuation stage.

[0020] In some embodiments of the present application, the separately determining the performance parameters of the battery at the boundary points between adjacent stages in each life attenuation stage includes: Based on the battery model included in the battery parameters, obtain the performance parameters of the battery at the boundary points between adjacent stages in each life attenuation stage from the second mapping relationship between the battery model and the performance parameters at the boundary points stored in advance; Among them, the second mapping relationship is determined based on the cycle test data of the sample battery of the battery model.

[0021] After the second mapping relationship is pre-configured, when it is necessary to predict the life attenuation curve of the battery to be predicted, it is only necessary to query the performance parameters of the corresponding boundary points from the second mapping relationship based on the battery model of the battery, which can shorten the time consumed to determine the performance parameters of each boundary point and improve the processing efficiency.

[0022] In some embodiments of the present application, the construction process of the second mapping relationship includes: Perform a cycle test on the sample battery at the nominal rate of the sample battery at a preset temperature to obtain the cycle test data of the sample battery; Based on the battery parameters of the sample battery, determine each life attenuation stage of the sample battery; Based on the cycle test data, separately determine the performance parameters of the battery at the boundary points between adjacent stages in each life attenuation stage of the sample battery; Store the battery model and the performance parameters at each boundary point as the second mapping relationship.

[0023] In the above manner, as long as the sample battery is subjected to cyclic testing and the life attenuation stage is determined, the second mapping relationship can be obtained, without the need to determine the second mapping relationship temporarily during the process of predicting the life of the battery to be predicted, which can improve the life prediction efficiency of the battery to be predicted.

[0024] In some embodiments of the present application, determining the performance parameters at the demarcation points between adjacent stages in each life attenuation stage of the sample battery based on the cyclic test data includes: Based on the cyclic test data, fitting a curve of the attenuation slope varying with the battery performance parameters; the attenuation slope is used to characterize the attenuation amount of the battery performance parameters corresponding to a preset number of cycles. Based on the curve, determining the performance parameters at the demarcation points between adjacent stages in each life attenuation stage of the sample battery.

[0025] Since this curve can accurately and intuitively depict the life attenuation law of the sample battery, the performance parameters at the demarcation points between adjacent stages in each life attenuation stage of the sample battery can be accurately identified based on this curve, improving the identification accuracy of the performance parameters at the demarcation points.

[0026] In some embodiments of the present application, determining the performance parameters at the demarcation points between adjacent stages in each life attenuation stage of the sample battery based on the curve includes: In the case where the sample battery includes an initial rapid attenuation stage and a middle slow attenuation stage, based on the curve, determining the performance parameters at the first demarcation point between the initial rapid attenuation stage and the middle slow attenuation stage. In the case where the sample battery includes a linear attenuation stage, based on the curve, determining the performance parameters at the second demarcation point between the linear attenuation stage and the previous adjacent attenuation stage. In the case where the sample battery includes a final accelerated attenuation stage, based on the cyclic test data, determining the electrolyte consumption rate of the sample battery; based on the electrolyte consumption rate and the initial electrolyte filling amount of the sample battery, determining the third demarcation point of electrolyte dry-out of the sample battery, and taking the performance parameters at the third demarcation point as the performance parameters at the demarcation point between the final accelerated attenuation stage and the previous adjacent attenuation stage.

[0027] Since the change curve can accurately and intuitively depict the life attenuation law of the sample battery, the first demarcation point at which the sample battery switches from the initial rapid attenuation stage to the intermediate slow attenuation stage can be accurately identified based on this change curve, improving the identification accuracy of the performance parameters at the demarcation point between the initial rapid attenuation stage and the intermediate slow attenuation stage. The reason for the formation of the linear attenuation stage is that after the SEI film of the battery grows to a certain extent, the dissolution rate and growth rate of the SEI film are the same, the thickness of the SEI film no longer changes, and at this time, the attenuation rate of the battery remains unchanged, and the attenuation is along a linear attenuation. However, due to the high measurement difficulty of the SEI film, fitting the change curve of the above attenuation slope using the cyclic test data of the sample battery and using this change curve to identify the second demarcation point between the linear attenuation stage and the previous adjacent attenuation stage converts the difficult method of measuring the SEI film into a simple and easy-to-operate method of fitting the change curve, improving the efficiency and accuracy of identifying the second demarcation point. For the final accelerated attenuation stage, the above process fully considers the influence of the electrolyte on the battery life attenuation, determines the electrolyte consumption rate of the sample battery using the cyclic test data, estimates the timing of the electrolyte dry-out of the sample battery, and then determines the performance parameters at the third demarcation point between the final accelerated attenuation stage and the previous adjacent attenuation stage, achieving rapid and accurate identification of the performance parameters at the demarcation point between the final accelerated attenuation stage and the previous adjacent attenuation stage.

[0028] In some embodiments of the present application, generating the life attenuation curve of the battery based on the cyclic test data of the battery in the first stage and the performance parameters at each demarcation point includes: Fitting a first life function relationship of the first stage based on the cyclic test data of the battery in the first stage; Based on the first life function relationship and the performance parameters at each demarcation point, obtaining the life function relationships of the stages other than the first stage in each life attenuation stage included in the battery; Drawing the life attenuation curve of the battery based on the life function relationships of each life attenuation stage included in the battery.

[0029] In the embodiments of the present application, only the cyclic test data of the battery in the first stage needs to be used, without obtaining the cyclic test data of each stage of the entire life cycle of the battery, reducing the workload of the cyclic test and the amount of cyclic test data to be collected, and reducing the cost. Using the cyclic test data of the first stage and combining the performance parameters at the demarcation points between adjacent stages in each life attenuation stage of the battery, the life attenuation curve of the battery can be obtained, which helps to improve the efficiency and accuracy of predicting the life attenuation curve.

[0030] In some embodiments of the present application, obtaining the life function relationships of the stages other than the first stage in each life attenuation stage included in the battery based on the first life function relationship and the performance parameters at each of the demarcation points includes: Based on the first life function relationship, the slopes of the life attenuation curves of the first stage and the second stage are equal at the first demarcation point between the first stage and the second stage, and the life values of the first stage and the second stage are both equal to the performance parameter at the first demarcation point, to obtain the second life function relationship of the second stage; the second stage is any stage adjacent to the first stage among the life attenuation stages included in the battery.

[0031] For adjacent life attenuation stages, if the life function relationship of one of the life attenuation stages is known, the life function relationship of the unknown life attenuation stage can be solved by using the correlation relationship between the adjacent life attenuation stages at their demarcation point. Therefore, for each life attenuation stage included in the battery, after obtaining the life function relationship of any one stage, by using the correlation relationship between adjacent life attenuation stages, the life function relationships of all life attenuation stages can be obtained quickly. So only the cyclic test data of the battery in one life attenuation stage needs to be collected, and the life function relationship of this life attenuation stage is fitted, then the life function relationships of all life attenuation stages of the battery can be obtained, and further the life attenuation curve of the entire life cycle of the battery can be obtained, greatly improving the efficiency of battery life prediction, reducing the amount of data collection required for life prediction, reducing costs, and at the same time improving the accuracy of life prediction.

[0032] In a second aspect of the embodiments of the present application, a device for predicting a battery life attenuation curve is provided, including: A first determination module, configured to determine each life attenuation stage of the battery based on the battery parameters of the battery; A second determination module, configured to respectively determine the performance parameters of the battery at the demarcation points of adjacent stages among each life attenuation stage; A generation module, configured to generate the life attenuation curve of the battery based on the cyclic test data of the battery in the first stage and the performance parameters at each of the demarcation points, where the first stage is any one of each life attenuation stage.

[0033] In a third aspect of the embodiments of the present application, an electronic device is provided, including a memory, a processor, and a computer program stored on the memory and executable on the processor, where the processor executes the program to implement the method described in the first aspect above.

[0034] In a fourth aspect of the embodiments of the present application, a computer-readable storage medium is provided, on which a computer program is stored, and the program is executed by a processor to implement the method described in the first aspect above.

[0035] In an embodiment of a fifth aspect of the present application, a computer program product is provided, including a computer program, and the computer program is executed by a processor to implement the method described in the first aspect.

[0036] The above description is only an overview of the technical solutions of the embodiments of the present application. In order to be able to understand the technical means of the embodiments of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the embodiments of the present application more obvious and understandable, the specific embodiments of the present application are specifically described below. Description of the Drawings

[0037] By reading the detailed description of the following embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the embodiments of the present application and are not considered as a limitation of the present application. And in all the drawings, the same reference numerals are used to represent the same components. In the drawings: Figure 1 is a flowchart of a method for predicting a battery life attenuation curve provided according to some embodiments of the present application; Figure 2 is a flowchart of another method for predicting a battery life attenuation curve provided according to some embodiments of the present application; Figure 3 is a schematic flowchart of determining each life attenuation stage of a battery provided according to some embodiments of the present application; Figure 4 is a flowchart of another method for predicting a battery life attenuation curve provided according to some embodiments of the present application; Figure 5 is a schematic flowchart of determining performance parameters at a demarcation point between adjacent life attenuation stages provided according to some embodiments of the present application; Figure 6 is a schematic flowchart of predicting a life attenuation curve of a lithium iron phosphate battery provided according to some embodiments of the present application; Figure 7 is a schematic diagram of an attenuation curve of a battery provided according to some embodiments of the present application; Figure 8 is a schematic structural diagram of a device for predicting a battery life attenuation curve provided according to some embodiments of the present application; Figure 9 is a schematic structural diagram of an electronic device provided according to some embodiments of the present application. Detailed Embodiments

[0038] The embodiments of the technical solution of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present application more clearly, so they are only examples and cannot be used to limit the protection scope of the present application.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above description of the drawings are intended to cover non-exclusive inclusion.

[0040] In the description of the embodiments of this application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "a plurality" is more than two, unless otherwise specifically defined.

[0041] Referring to "embodiments" herein means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of this application. The phrase appears in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0042] In the description of the embodiments of this application, the term "and / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: there is A, there is both A and B, and there is B. In addition, the character " / " in this article generally means that the associated objects before and after are in an "or" relationship.

[0043] In the description of the embodiments of this application, the term "a plurality" refers to more than two (including two). Similarly, "a plurality of groups" refers to more than two groups (including two groups), and "a plurality of pieces" refers to more than two pieces (including two pieces).

[0044] The battery life attenuation curve is a curve depicting the change of battery performance over time or the degree of use (such as the number of charge-discharge cycles). The horizontal axis of the battery life attenuation curve usually represents the degree of use of the battery, which can be the number of charge-discharge cycles, time, depth of discharge, etc. The vertical axis of the battery life attenuation curve represents the key performance indicators of the battery. In the embodiments of this application, the vertical axis is represented as a performance parameter, and the performance parameter can be, but is not limited to, any one of the state of health (SOH), capacity, energy, energy efficiency, etc. of the battery.

[0045] The battery life attenuation curve shows the whole process of the battery from the initial state to a significant decline in performance. It is a tool for evaluating the battery life and health status. Analyzing the battery life attenuation curve helps to accurately understand the life characteristics of lithium batteries, use lithium batteries reasonably, extend their service life, improve the safety of battery use, and replace batteries with poor health conditions in a timely manner, etc.

[0046] In the related art, a solution for obtaining the battery life attenuation curve is provided. This solution measures the actual data during the battery's cyclic use and fits the battery life attenuation curve based on the actual data. However, since the performance of lithium batteries shows a certain degree of attenuation as the number of cyclic uses increases during use, there are obvious differences in the battery life attenuation characteristics at different usage stages in the entire life cycle of the battery. And the accuracy of the battery life attenuation curve fitted by the related art depends on the richness of the collected data. Therefore, in order to improve the accuracy of the fitted battery life attenuation curve, the related art needs to collect a large amount of actual data at different usage stages in the entire life cycle of the battery, which results in a large amount of data collection and high costs.

[0047] Based on the above problems existing in the related art, some embodiments of the present application propose a prediction method, device, equipment, storage medium, and program product for the battery life attenuation curve. This prediction method determines each life attenuation stage of the battery based on the battery parameters of the battery; respectively determines the performance parameters of the battery at the demarcation points between adjacent stages in each life attenuation stage; and generates the battery life attenuation curve based on the cyclic test data of the battery in the first stage and the performance parameters of the battery at each demarcation point, where the first stage is any one of the life attenuation stages.

[0048] This method first determines the actual life attenuation stages of the battery and the performance parameters of the battery at the demarcation points between adjacent stages in each life attenuation stage. Then, based on the cyclic test data of any stage of the battery and the performance parameters of the battery at the demarcation points between adjacent stages in each life attenuation stage, the battery life attenuation curve can be generated. In this process, only the cyclic test data of one of the life attenuation stages of the battery needs to be collected, and there is no need to collect the cyclic test data of each stage in the entire life cycle of the battery. The amount of data to be collected is very small and the cost is low. Based on the small amount of collected data and the performance parameters of the battery at the demarcation points between adjacent stages included in each life attenuation stage of the battery, the battery life attenuation curve is generated. The accuracy of the generated life attenuation curve is little affected by the amount of collected data, which can effectively improve the efficiency and accuracy of predicting the life attenuation curve.

[0049] In some embodiments of the present application, the battery may be, but is not limited to, a battery cell, a single battery, a battery module, a battery pack, an energy storage cabinet, an energy storage container, etc. The battery may be a lithium-ion battery, including but not limited to lithium cobalt oxide battery, lithium manganese oxide battery, lithium nickel oxide battery, lithium iron phosphate battery, etc. For batteries of any chemical system without lithium, if there are obvious differences in the life attenuation characteristics of the battery at different usage stages in the entire life cycle of the battery and it can be divided into multiple life attenuation stages, then the prediction method of the battery life attenuation curve provided by some embodiments of the present application is also applicable. The batteries mentioned in the following discussion are illustrated by taking lithium-ion batteries as an example.

[0050] In some embodiments of the present application, the battery may be a battery of any shape and structure. For example, the battery may be a cylindrical battery, a flat battery, a soft-pack battery, a square battery, etc. The battery can be applied to any application scenario where a battery is needed. The battery can be used as a consumer electronics battery, such as for mobile phones, laptops, etc. The battery can also be used as an energy storage battery, and the battery can also be used as a power battery, such as for electric vehicles, electric bicycles, electric aircraft, electric ships, etc.

[0051] The prediction method of the battery life attenuation curve provided by some embodiments of the present application can predict the battery in any usage state, that is, at any moment in the entire life cycle of the battery, the prediction method provided by the embodiments of the present application can be used to predict the battery life attenuation curve. For example, for a newly produced battery, a newly put into use battery, a battery after being used for a period of time, etc., the battery life attenuation curve can be predicted.

[0052] Some embodiments of the present application provide a prediction method of a battery life attenuation curve. Refer to Figure 1 , and this method includes the following steps 101-103.

[0053] Step 101: Based on the battery parameters of the battery, determine each life attenuation stage of the battery.

[0054] Step 102: Respectively determine the performance parameters of the battery at the demarcation points between adjacent stages in each life attenuation stage.

[0055] Step 103: Based on the cycle test data of the battery in the first stage and the performance parameters at each demarcation point, generate the battery life attenuation curve, where the first stage is any one of the life attenuation stages.

[0056] In some embodiments of the present application, the execution subject for executing the prediction method of the battery life attenuation curve can be any device with computing power, including but not limited to a physical server, a server cluster, a cloud server, a mobile phone, a computer, a vehicle-mounted terminal, etc.

[0057] The battery performance shows a certain degree of attenuation as the number of charge-discharge cycles increases. There are obvious differences in the battery life attenuation characteristics throughout the entire life cycle of the battery. Based on these differences in life attenuation characteristics, the embodiments of this application divide the possible life attenuation stages of the battery, specifically at least into an initial rapid attenuation stage, a mid-term slow attenuation stage, a linear attenuation stage, and a final accelerated attenuation stage.

[0058] The above division of the life attenuation stages is mainly based on the growth and consumption rules of the SEI (Solid Electrolyte Interphase) film on the negative electrode of the battery. In a lithium-ion battery, the main reason for the battery life attenuation is the formation and growth of the SEI film on the negative electrode. The formation process of the SEI film consumes the active lithium in the battery, and the reduction of active lithium directly leads to the attenuation of the battery capacity. As the SEI film continues to grow, this consumption continues, resulting in a gradual decline in the overall performance of the battery.

[0059] When the battery is first used, that is, in the early stage of the battery, the formation and growth rate of the SEI film are relatively fast. At this time, the SEI film is relatively thin and unstable. This instability makes the SEI film more prone to phenomena such as rupture and recombination. Due to the instability of the SEI film, it will accelerate the consumption of active lithium in the battery. The rapid consumption of active lithium causes the available capacity of the battery to rapidly decrease and the state of health (SOH) of the battery to rapidly decline. Therefore, the performance of the battery deteriorates significantly in a short period of time. The embodiments of this application divide the initial rapid attenuation stage based on the characteristics of rapid attenuation in the early stage of the battery.

[0060] After the battery has been used for a period of time and has gone through the above initial rapid attenuation stage, the structure of the SEI film becomes relatively stable and the growth rate slows down. The reaction of the SEI film consuming active lithium is not as intense as in the early stage. Since the growth of the SEI film slows down, the consumption rate of active lithium also decreases accordingly. Therefore, the loss rate of the battery capacity also slows down, entering a relatively stable slow attenuation stage. The embodiments of this application refer to this stage as the mid-term slow attenuation stage.

[0061] As the battery is used for a longer time, the SEI film grows to a certain extent, and the dissolution rate and growth rate of the SEI film reach a dynamic equilibrium. The dissolution rate refers to the process in which the components of the SEI film may dissolve into the electrolyte under the electrochemical environment of the battery operation. The growth rate refers to the speed at which new SEI film materials are still being generated due to the charge and discharge reactions of the battery. When the dissolution rate is equal to the growth rate, the thickness of the SEI film no longer changes. Because macroscopically, the generated part is just offset by the dissolved part. Once the thickness of the SEI film is stable, the attenuation rate of the battery remains unchanged at this time, that is, the battery life attenuation follows a linear attenuation. Linear attenuation can be understood as the performance of the battery (such as capacity, energy, energy efficiency, etc.) decreasing at a relatively stable rate over time. The embodiments of the present application refer to this stage as the linear attenuation stage.

[0062] When the battery is used in the later stage, the electrolyte is gradually consumed during the long-term electrochemical reaction process, and the situation of insufficient electrolyte may occur. During the charge and discharge process of the battery, ions need to migrate between the positive and negative electrodes through the electrolyte. When the electrolyte is insufficient, the ion migration channel is restricted, which will cause the electrochemical reaction inside the battery to not proceed normally. Moreover, insufficient electrolyte may also cause local overheating inside the battery. Because the electrolyte also has a heat dissipation effect to a certain extent, when it is insufficient, the heat cannot be dissipated in time, accelerating the aging and performance attenuation of the materials inside the battery. Therefore, insufficient electrolyte in the later stage of battery use will cause the battery performance attenuation to accelerate sharply. The embodiments of the present application refer to this stage as the terminal accelerated attenuation stage.

[0063] Due to differences in the structure, chemical system, and usage conditions of different batteries, the actual life attenuation stages included in different batteries may be different, and the actual life attenuation stages included in a battery may be some or all of the above-defined life attenuation stages.

[0064] For the battery to be predicted, some embodiments of the present application determine the actual life attenuation stage of the battery based on the battery parameters of the battery itself, and then determine the performance parameters of the battery at the boundary point between any two adjacent stages among the life attenuation stages of the battery. The performance parameters can be any one of SOH, capacity, energy, energy efficiency, etc. Using the cycle test data of any life attenuation stage of the battery and the performance parameters at the boundary point between any two adjacent stages as described above, the life attenuation curve of the entire life cycle of the battery can be obtained.

[0065] Based on the battery parameters of the battery itself, the above embodiments automatically determine the actual life attenuation stages of the battery. For the division of the life attenuation stages of the battery to be predicted, it is more in line with the actual situation of the battery, and the accuracy is very high. By using the cycle test data of any life attenuation stage of the battery and the performance parameters at the boundary point between any two adjacent stages, the life attenuation curve of the battery can be obtained. The amount of measured data required in the whole prediction process is very small, which can reduce a large amount of actual test time, improve the battery life prediction efficiency, and at the same time reduce the cost caused by actual tests. During the process of predicting the life attenuation curve of the battery, the actual life attenuation stages of the battery are divided and the performance parameters at the boundary point between any two adjacent stages are determined. Therefore, the finally obtained life attenuation curve includes the life attenuation conditions of each life attenuation stage of the battery, realizing the staged description of the life attenuation curve of the battery, reducing the dependence of the accuracy of the life attenuation curve on the measured data, and effectively improving the accuracy of the life attenuation curve.

[0066] In some embodiments of the present application, the actual life attenuation stages included in the battery can be determined in the following manner, including: determining the life attenuation stages of the battery based on the initial electrolyte filling amount and / or the performance lower limit threshold included in the battery parameters; wherein, the performance lower limit threshold is used to characterize that the battery stops being used when the performance parameter of the battery reaches the performance lower limit threshold.

[0067] The initial electrolyte filling amount of the battery refers to the amount of electrolyte first filled into the battery during the manufacturing process of the battery. The initial electrolyte filling amount can be determined according to factors such as the specifications of the battery, design requirements, and electrode materials. The initial electrolyte filling amount has an impact on the initial performance of the battery and the performance during subsequent use.

[0068] The performance lower limit threshold of the battery refers to that when the performance of the battery drops to a specific performance level during use, the battery needs to stop being used. This performance level is usually set as the standard for "end of life" of the battery. The performance lower limit threshold can be the lower limit threshold of any one of the performance indicators such as SOH, capacity, energy, energy efficiency, etc. The performance lower limit threshold uses the same performance indicator as the performance parameter in step 102. For example, if the performance parameter in step 102 is capacity, then the performance lower limit threshold is the lower limit threshold of capacity.

[0069] The initial electrolyte filling amount has an obvious impact on the battery life attenuation stage. In the initial stage of the battery, the amount of electrolyte is sufficient, and the electrolyte can fully infiltrate the electrode material, enabling the battery to have good ion transport and electrochemical reactions. As the battery is used, the electrolyte will be gradually consumed, especially the electrolyte used to form and maintain the SEI film. The reduction of the electrolyte will lead to insufficient infiltration on the surface of the electrode material, affecting the ion transport efficiency, thus causing the battery performance to start to decline and the battery attenuation rate to accelerate. When the amount of electrolyte is reduced to a certain extent and cannot meet the infiltration and ion transport requirements of the electrode material, the battery performance will decline sharply. Therefore, the size of the initial electrolyte filling amount has an important impact on the attenuation of battery performance. Determining each life attenuation stage of the battery based on the initial electrolyte filling amount fully considers the influence of the initial electrolyte filling amount on battery life attenuation. The determined life attenuation stage is closer to the actual situation of the battery, improving the accuracy of determining the life attenuation stage.

[0070] The performance lower limit threshold refers to the lower limit threshold reached by the battery performance when the battery is stopped from being used due to the decline in battery performance affecting its use. When the battery performance drops to the set performance lower limit threshold, it is considered that the battery reaches the end-of-life point. If the battery continues to be used, the attenuation rate will further accelerate and the performance indicators will deteriorate rapidly. Therefore, it is necessary to replace the battery when the battery performance parameters reach the performance lower limit threshold. After the battery is replaced and stopped from being used, the subsequent life attenuation situation of the battery can be ignored. Therefore, the life lower limit threshold will affect the determination of the life attenuation stage in the later stage of battery use. Determining each life attenuation stage of the battery based on the performance lower limit threshold can improve the accuracy of determining the life attenuation stage in the later stage of battery use.

[0071] In some of the above embodiments, it is also possible to combine the initial electrolyte filling amount and the performance lower limit threshold to determine each life attenuation curve of the battery, considering both the influence of the initial electrolyte filling amount on the performance attenuation during the entire life cycle of the battery and the influence of the performance lower limit threshold on the life attenuation stage in the later stage of battery use. The considered factors are more comprehensive, making the determination of each life attenuation stage of the battery more accurate.

[0072] In some embodiments of the present application, such as Figure 2 shown, based on the initial electrolyte filling amount, the following specific method can be used to determine each life attenuation stage of the battery, including: Step 1011: Based on the initial electrolyte filling amount and the preset electrolyte consumption rate of the battery, determine the target number of cycles required for the initial electrolyte filling amount to be consumed completely.

[0073] Step 1012: Based on the target number of cycles, determine each life attenuation stage included in the battery.

[0074] The preset electrolyte consumption rate of a battery refers to the rate at which the electrolyte is consumed during the use of the battery, which is preset according to factors such as the chemical system of the battery, electrode materials, and usage conditions during the battery design and manufacturing process.

[0075] The above preset electrolyte consumption rate may refer to the amount of electrolyte consumed by the battery in each cycle. The ratio of the initial electrolyte filling amount of the battery to the preset electrolyte consumption rate can be calculated, and this ratio can be used as the target number of cycles required for the initial electrolyte filling amount to be consumed completely. In some other embodiments, in order to prevent the battery from suddenly failing due to electrolyte depletion during use, a margin coefficient can also be introduced. The margin coefficient is used to characterize that when the battery consumes the electrolyte of this margin coefficient, the above target number of cycles is reached. For example, the margin coefficient can be set to 90%, indicating that when 90% of the initial electrolyte filling amount of the battery is consumed, the number of cycles of the battery reaches the target number of cycles. In the case of introducing the margin coefficient, the product of the initial electrolyte filling amount of the battery and the margin coefficient can be calculated first, and the ratio of this product to the preset electrolyte consumption rate can be calculated, and this ratio can be used as the target number of cycles required for the initial electrolyte filling amount to be consumed completely.

[0076] Using the initial electrolyte filling amount of the battery and the preset electrolyte consumption rate, the target number of cycles experienced by the battery when the electrolyte dries up is estimated, and each life attenuation stage included in the battery is determined based on this target number of cycles. It fully considers the influence of electrolyte dry-up on the life attenuation stage of the battery during the entire life cycle of the battery, and can accurately determine each actual life attenuation stage included in the battery.

[0077] In some embodiments of the present application, as Figure 3 shown, based on the target number of cycles, each life attenuation stage included in the battery can be determined specifically in the following manner: Step 10121: If the target number of cycles is less than or equal to the first number of cycles required for the battery to reach the starting point of the linear attenuation stage, it is determined that the battery includes an initial rapid attenuation stage, a middle slow attenuation stage, and a final accelerated attenuation stage.

[0078] Step 10122: If the target number of cycles is greater than the first number of cycles and less than or equal to the second number of cycles required for the battery to reach the end point of the linear attenuation stage, it is determined that the battery includes an initial rapid attenuation stage, a middle slow attenuation stage, a linear attenuation stage, and a final accelerated attenuation stage.

[0079] Step 10123: If the target number of cycles is greater than the number of cycles corresponding to the performance lower limit threshold of the battery, it is determined that the battery includes an initial rapid attenuation stage, a middle slow attenuation stage, and a linear attenuation stage.

[0080] The first number of cycles required for the above battery to reach the starting point of the linear attenuation stage, and the second number of cycles required for the battery to reach the ending point of the linear attenuation stage can be obtained in various ways. As an example, sample batteries of the same model and batch as the battery to be predicted can be selected, and the sample batteries can be cycled using a battery testing device to obtain test data. Among them, the battery testing device can include, but is not limited to, a battery cycler, a charge and discharge tester, etc. The test data can include, but is not limited to, initial parameters such as the initial capacity, internal resistance, and voltage of the sample battery, as well as parameters such as capacity, internal resistance, and voltage after each cycle. Then, based on the test data, the life attenuation curve of the sample battery is fitted, and the first number of cycles corresponding to the starting point of the sample battery entering the linear attenuation stage and the second number of cycles corresponding to the ending point of the sample battery reaching the linear attenuation stage are identified from the life attenuation curve of the sample battery. The above-mentioned fitting of the life attenuation curve of the sample battery based on the test data can adopt the fitting method in the related technology, which will not be elaborated here. As another example, a known empirical formula (such as the Arrhenius equation) can be used to predict the life and attenuation behavior of the battery, so as to estimate the first number of cycles corresponding to the starting point of the linear attenuation stage of the sample battery and the second number of cycles corresponding to the ending point. The specific processing process of using the empirical formula can refer to the method of the related technology, which will not be elaborated here.

[0081] After obtaining the above target number of cycles, the first number of cycles required for the battery to reach the starting point of the linear attenuation stage, and the second number of cycles required for the battery to reach the ending point of the linear attenuation stage, the target number of cycles is compared with the first number of cycles and the second number of cycles. If the target number of cycles is less than or equal to the first number of cycles, it indicates that the electrolyte dries up before the battery enters the linear attenuation stage. Therefore, after the battery experiences the initial rapid attenuation stage and the middle slow attenuation stage, it will enter the final accelerated attenuation stage due to the drying up of the electrolyte. So it is determined that the actual life attenuation stages included in the battery are the initial rapid attenuation stage, the middle slow attenuation stage, and the final accelerated attenuation stage.

[0082] If it is compared that the target number of cycles is greater than the first number of cycles and less than or equal to the second number of cycles, it indicates that the electrolyte dries up after the battery enters the linear attenuation stage. Therefore, the battery will experience the initial rapid attenuation stage, the middle slow attenuation stage, and the linear attenuation stage, and then enter the final accelerated attenuation stage due to the drying up of the electrolyte. So it is determined that the actual life attenuation stages included in the battery are the initial rapid attenuation stage, the middle slow attenuation stage, the linear attenuation stage, and the final accelerated attenuation stage.

[0083] If it is determined that the target number of cycles is greater than the number of cycles corresponding to the performance lower threshold, since the performance lower threshold refers to the lower threshold of the battery performance when the battery is stopped from being used due to the battery performance degradation to an extent that affects the use. The battery will be stopped from being used when the remaining life of the battery reaches the performance lower threshold. If the target number of cycles is greater than the number of cycles corresponding to the performance lower threshold, it indicates that the electrolyte in the battery has not dried up when the battery performance degrades to an extent that affects the use and the battery is stopped from being used. In this case, the battery will not experience a sharp decline in performance due to the drying up of the battery. Therefore, it is determined that the battery does not have an end-stage accelerated decay phase, that is, the actual life decay phases included in the battery include an initial rapid decay phase, a middle slow decay phase, and a linear decay phase.

[0084] Using the initial electrolyte filling amount of the battery and the preset electrolyte consumption rate, estimate the target number of cycles experienced by the battery when the electrolyte dries up. Based on the comparison of the target number of cycles with the first number of cycles at the starting point of the linear decay phase of the battery, the second number of cycles at the ending point of the linear decay phase, and the number of cycles corresponding to the battery reaching the performance lower threshold, through simple numerical comparison, the actual life decay phases included in the battery can be determined. In this way, fully considering the impact of electrolyte drying up at different stages in the entire life cycle of the battery on the life decay phases of the battery, the actual life decay phases included in the battery can be accurately determined. Compared with the related art that can only know which life decay phases the battery includes after fitting the life decay curve based on a large number of measured data in the entire life cycle, the embodiments of the present application can, before obtaining the life decay curve, pre-determine the actual life decay phases included in the battery based on the initial electrolyte filling amount of the battery, and then use the actual life decay phases included in the battery to assist in predicting the life decay curve of the battery, providing a solution for predicting the life decay curve that is substantially different from the related art. And since the life decay phases of the battery are known before prediction, it also helps to improve the accuracy of predicting the life decay curve.

[0085] In some embodiments of the present application, as Figure 4 shown, based on the performance lower threshold of the battery, the actual life decay phases of the battery can be determined in the following manner, including: Step 10131: Determine that the battery includes an initial rapid decay phase and a middle slow decay phase based on the fact that the performance lower threshold is less than or equal to the performance parameter at the starting point of the battery entering the linear decay phase.

[0086] Step 10132: Determine that the battery includes an initial rapid decay phase, a middle slow decay phase, and a linear decay phase based on the fact that the performance lower threshold is greater than the performance parameter at the starting point and less than or equal to the performance parameter at the ending point of the linear decay phase.

[0087] Step 10133: Based on the performance lower limit threshold being greater than the performance parameter at the end point, it is determined that the battery includes an initial rapid decay stage, a mid-term slow decay stage, a linear decay stage, and a final accelerated decay stage.

[0088] For the performance parameters at the starting point where the above-mentioned battery enters the linear decay stage and the performance parameters at the end point where the battery reaches the end of the linear decay stage, the acquisition methods of these two performance parameters can be similar to the acquisition methods of the first cycle number at the starting point where the battery enters the linear decay stage and the second cycle number at the end point of the linear decay stage described above. That is, by conducting experimental tests on sample batteries of the same model and batch as the battery, fitting the life decay curve based on the measured data, and then determining the performance parameters at the starting point and end point of the linear decay stage based on the life decay curve. Or, known empirical formulas can also be used to analyze and obtain the performance parameters at the starting point and end point of the linear decay stage. The specific acquisition process will not be elaborated here.

[0089] The above-mentioned performance parameters can be, but are not limited to, any one of battery health SOH, capacity, energy, or energy efficiency, etc. Correspondingly, the performance lower limit threshold can also include battery health SOH, capacity, energy, or energy efficiency, etc. The performance parameters and the performance lower limit threshold are represented by the same parameter. For example, both use battery health SOH, or both use capacity, etc.

[0090] In the case where the performance lower limit threshold is less than or equal to the performance parameter at the starting point where the battery enters the linear decay stage, it indicates that the battery reaches the performance lower limit threshold before entering the linear decay stage and is then stopped from being used. In this case, the battery does not include the linear decay stage and subsequent stages. Therefore, the actual life decay stages included in the battery are the initial rapid decay stage and the mid-term slow decay stage.

[0091] In the case where the performance lower limit threshold is greater than the performance parameter at the starting point where the battery enters the linear decay stage and less than or equal to the performance parameter at the end point of the linear decay stage, it indicates that the battery reaches the performance lower limit threshold after entering the linear decay stage. Therefore, before being stopped from being used, the actual life decay stages experienced by the battery include the initial rapid decay stage, the mid-term slow decay stage, and the linear decay stage.

[0092] In the case where the performance lower limit threshold is greater than the performance parameter at the end point of the linear decay stage, it indicates that the battery will reach the performance lower limit threshold after the end of the linear decay stage of the battery. Therefore, after the end of the linear decay stage, the battery will also enter the final accelerated decay stage. So, it is determined that the battery actually includes the initial rapid decay stage, the mid-term slow decay stage, the linear decay stage, and the final accelerated decay stage.

[0093] The above embodiments fully consider the influence of the lower limit threshold of the battery performance on the battery life attenuation stage, can accurately determine each actual life attenuation stage of the battery, can pre-determine each life attenuation stage included in the battery based on the lower limit threshold of the battery performance before obtaining the life attenuation curve, and then use each life attenuation stage included in the battery to assist in predicting the life attenuation curve of the battery. Since the life attenuation stage of the battery is known before prediction, it helps to improve the accuracy of predicting the life attenuation curve.

[0094] In some embodiments of the present application, each life attenuation stage of the battery can also be determined based on the initial electrolyte filling amount and the lower limit threshold of the performance, specifically including: determining the first stage combination composed of each life attenuation stage determined based on the initial electrolyte filling amount, and the second stage combination composed of each life attenuation stage determined based on the lower limit threshold of the performance, and determining each life attenuation stage of the battery.

[0095] In one implementation manner, the intersection of the first stage combination and the second stage combination can be taken, and the life attenuation stages included in the intersection are used as each life attenuation stage of the battery.

[0096] In another implementation manner, from the first stage combination and the second stage combination, the combination with the least number of included stages is determined; each life attenuation stage in the combination with the least number of included stages is determined as each life attenuation stage of the battery.

[0097] According to the method for determining the life attenuation stage based on the initial electrolyte filling amount as described above, the first stage combination is determined. According to the method for determining the life attenuation stage based on the lower limit threshold of the performance as described above, the second stage combination is determined. Then, each life attenuation stage of the battery is determined by comprehensively considering the first stage combination and the second stage combination. In this way, the influence of the electrolyte and the lower limit threshold of the performance on the battery life attenuation stage is comprehensively considered, which can effectively improve the accuracy of the finally determined life attenuation stage, and further helps to improve the accuracy of subsequent life attenuation curve prediction.

[0098] In some embodiments of the present application, each life attenuation stage of the battery can also be determined by the following method, including: obtaining each life attenuation stage of the battery from the first mapping relationship between the battery model and the life attenuation stage stored in advance based on the battery model included in the battery parameters; wherein, the first mapping relationship is determined based on the initial electrolyte filling amount and / or the lower limit threshold corresponding to the battery model, and the lower limit threshold of the performance is used to characterize that the battery stops being used when the performance parameter of the battery of the battery model reaches the lower limit threshold.

[0099] In these embodiments, based on the initial electrolyte filling amount and / or the lower limit threshold of the performance corresponding to the battery model to be predicted in advance, each life attenuation stage of the battery of this battery model is determined in the manner provided in the foregoing embodiments. Then, in the device for executing the prediction method provided in the embodiments of the present application, the first mapping relationship between this battery model and each life attenuation stage of the battery belonging to this battery model is pre-configured.

[0100] After the first mapping relationship is pre-configured, when it is necessary to predict the life attenuation curve of the battery to be predicted, it is only necessary to query the corresponding life attenuation stage from the first mapping relationship based on the battery model of the battery, which can shorten the time consumed to determine each life attenuation stage included in the battery and improve the processing efficiency. Moreover, the first mapping relationship is determined based on the initial electrolyte filling amount and / or the lower limit threshold of the performance corresponding to this battery model, fully considering the influence of the electrolyte and / or the lower limit threshold of the performance on the battery life attenuation, and improving the accuracy of determining the life attenuation stage.

[0101] In some embodiments of the present application, the performance parameters of the battery at the demarcation point between adjacent stages in each life attenuation stage can be determined by the following method, including: based on the battery model included in the battery parameters, obtaining the performance parameters of the battery at the demarcation point between adjacent stages in each life attenuation stage from the second mapping relationship between the battery model and the performance parameters at the demarcation point stored in advance; wherein, the second mapping relationship is determined based on the cycle test data of the sample battery of the battery model.

[0102] In these embodiments, a sample battery of the same model as the battery to be predicted is selected in advance, the sample battery is subjected to a cycle test to obtain cycle test data, the performance parameters at the demarcation point between adjacent life attenuation stages of the battery of this battery model are determined based on the cycle test data, and the second mapping relationship between the battery model and the performance parameters of each demarcation point is pre-configured in the device for executing the prediction method of the embodiments of the present application.

[0103] After the second mapping relationship is pre-configured, when it is necessary to predict the life attenuation curve of the battery to be predicted, it is only necessary to query the corresponding performance parameters of each demarcation point from the second mapping relationship based on the battery model of the battery, which can shorten the time consumed to determine the performance parameters of each demarcation point and improve the processing efficiency.

[0104] In some embodiments of the present application, the construction process of the above second mapping relationship may include: Perform a cycling test on the sample battery at the nominal rate of the sample battery at a preset temperature to obtain the cycling test data of the sample battery; determine the respective life attenuation stages of the sample battery based on the battery parameters of the sample battery; based on the cycling test data, respectively determine the performance parameters at the demarcation points between adjacent stages in the respective life attenuation stages of the sample battery; store the battery model and the performance parameters at each demarcation point as a second mapping relationship.

[0105] The nominal rate of the above-mentioned battery is the current intensity recommended for discharging or charging the battery during design. The preset temperature can be a relatively high temperature, and a relatively high temperature can accelerate battery aging and shorten the time of the cycling test. For example, the value range of the preset temperature can be, but is not limited to, [55°C, 60°C], [65°C, 80°C], etc. The two temperature ranges given here are only examples, and in actual applications, the preset temperature can be any temperature.

[0106] Using the preset temperature and the nominal rate as the cycling test conditions, perform a cycling test on the sample battery of the same model as the battery to be predicted to obtain the cycling test data of the sample battery. Among them, the cycling test data can include parameters such as the capacity, voltage, and resistance of the battery after each cycle.

[0107] For the sample battery, the respective life attenuation stages of the sample battery are also determined in the same way as the method for determining the life attenuation stages introduced above, and the specific determination process will not be elaborated here.

[0108] Based on the cycling test data of the sample battery, respectively determine the performance parameters at the demarcation points between adjacent stages in the respective life attenuation stages of the sample battery, and then pre-store the battery model of the sample battery and the performance parameters at each demarcation point as a second mapping relationship. In this way, as long as the cycling test and the determination of the life attenuation stage are performed on the sample battery, the second mapping relationship can be obtained, without having to determine the second mapping relationship temporarily during the process of predicting the life of the battery to be predicted, which can improve the life prediction efficiency of the battery to be predicted.

[0109] In some embodiments of the present application, during the above process of generating the second mapping relationship, the performance parameters at the demarcation points between adjacent stages in the respective life attenuation stages of the sample battery can be specifically determined by the following method, including: Based on the cycling test data, fit the curve of the attenuation slope changing with the battery performance parameters; the attenuation slope is used to characterize the attenuation amount of the battery performance parameters corresponding to the preset number of cycles; based on this change curve, respectively determine the performance parameters at the demarcation points between adjacent stages in the respective life attenuation stages of the sample battery.

[0110] The above-mentioned battery performance parameters can include, but are not limited to, any one of the state of health of the battery, capacity, energy, energy efficiency, etc. Taking the battery performance parameter as the state of health of the battery as an example, the expression formula of the attenuation slope can be: where k is the attenuation slope, is the attenuation amount of the battery health state, is the preset number of cycles. The value of can be, but is not limited to, 10, 15, 20, etc.

[0111] The cycle test data of the sample battery can include parameters such as the capacity, voltage, and resistance of the sample battery after each cycle. The ratio between the capacity of the sample battery after each cycle and the rated capacity of the sample battery can be calculated respectively to obtain the state of health (SOH) of the sample battery after each cycle. Then calculate the attenuation amount of the state of health of the sample battery after every preset number of cycles of the sample battery. For example, assuming = 10, then calculate the difference between the initial state of health of the sample battery and the state of health SOH of the sample battery after the 10th cycle, calculate the difference between the state of health SOH of the sample battery after the 20th cycle and the state of health SOH of the sample battery after the 10th cycle,..., and so on to obtain multiple values. Substitute these values into the above expression formula of the attenuation slope respectively, and multiple groups of arrays of ( , k) can be obtained.

[0112] After obtaining multiple groups of arrays of ( , k) in the above manner, a change curve of the attenuation slope k with respect to the state of health SOH of the battery can be plotted with the abscissa being SOH and the ordinate being k. This change curve can well reflect the attenuation law of the battery.

[0113] The above attenuation amount of the battery health state can also be processed in other ways. For example, a voltage change curve can be fitted based on the voltage of the sample battery after each cycle in the cycle test data, and the voltage change curve can be analyzed to determine the health state of the battery. The specific analysis method can adopt the methods of related technologies and will not be elaborated here.

[0114] The above attenuation slope is expressed based on the attenuation amount of the battery health state. In addition, it can also be expressed using battery performance parameters such as the capacity, energy, and energy efficiency of the battery. The processing method of using other battery performance parameters to represent the attenuation slope is similar to the above processing method using the attenuation amount of the battery health state and will not be elaborated here.

[0115] Since this change curve can accurately and intuitively depict the life attenuation law of the sample battery, the performance parameters at the demarcation points between adjacent stages in each life attenuation stage of the sample battery can be accurately identified based on this change curve, improving the identification accuracy of the performance parameters at the demarcation points.

[0116] In some embodiments of the present application, specifically, the following method can be used to determine the performance parameters at the boundary points between adjacent stages in each life attenuation stage of the sample battery: Figure 5 As shown below: Step A1: Based on the cycle test data, fit the curve of the attenuation slope varying with the battery performance parameters; the attenuation slope is used to characterize the attenuation amount of the battery performance parameters corresponding to a preset number of cycles.

[0117] Step A2: When the sample battery includes an initial rapid attenuation stage and a mid-term slow attenuation stage, based on the curve, determine the performance parameters at the first boundary point between the initial rapid attenuation stage and the mid-term slow attenuation stage.

[0118] Step A3: When the sample battery includes a linear attenuation stage, based on the curve, determine the performance parameters at the second boundary point between the linear attenuation stage and the previous adjacent attenuation stage.

[0119] Step A4: When the sample battery includes a final accelerated attenuation stage, based on the cycle test data, determine the electrolyte consumption rate of the sample battery; based on the electrolyte consumption rate and the initial electrolyte filling amount of the sample battery, determine the third boundary point of the electrolyte dry-out of the sample battery, and use the performance parameters at the third boundary point as the performance parameters at the boundary point between the final accelerated attenuation stage and the previous adjacent attenuation stage.

[0120] Based on this curve, identify the boundary point where the attenuation slope k changes from rapid change to slow change. This boundary point is the first boundary point between the initial rapid attenuation stage and the mid-term slow attenuation stage. Take the abscissa value at the first boundary point in this curve as the performance parameters at the first boundary point. Since this curve can accurately and intuitively depict the life attenuation law of the sample battery, the first boundary point where the sample battery switches from the initial rapid attenuation stage to the mid-term slow attenuation stage can be accurately identified based on this curve, improving the identification accuracy of the performance parameters at the boundary point between the initial rapid attenuation stage and the mid-term slow attenuation stage.

[0121] When the sample battery includes a linear attenuation stage, since the attenuation slope in the linear attenuation stage is a fixed value, in the above curve, the linear attenuation stage will correspond to a line segment parallel to the abscissa. Therefore, the second boundary point between the linear attenuation stage and the previous adjacent attenuation stage can be easily identified from the above curve, and the abscissa value at the second boundary point is taken as the performance parameters at the second boundary point.

[0122] The reason for the formation of the linear attenuation stage is that after the SEI film of the battery grows to a certain extent, the dissolution rate and growth rate of the SEI film are the same, the thickness of the SEI film no longer changes, and at this time the attenuation rate of the battery remains unchanged, and the attenuation is linear. However, due to the high difficulty of measuring the SEI film, the change curve of the above attenuation slope is fitted using the cycle test data of the sample battery, and this change curve is used to identify the second demarcation point between the linear attenuation stage and the previous adjacent attenuation stage, converting the difficult way of measuring the SEI film into a simple and easy-to-operate way of fitting the change curve, improving the efficiency and accuracy of identifying the second demarcation point.

[0123] The late-stage accelerated attenuation stage is the stage in which the battery performance drops sharply due to the drying up of the electrolyte in the battery. During the cycling process, the consumption of the electrolyte will lead to the loss of active lithium and an increase in side reactions of the electrode material, thus affecting the battery capacity. Therefore, the capacity attenuation can be used as an indirect indicator of the electrolyte consumption. As the electrolyte is consumed, the conductivity of the electrolyte will decrease, and the ion transport resistance inside the battery will increase, resulting in an increase in the battery internal resistance. Therefore, the increase in internal resistance can also be used as an indirect indicator of the electrolyte consumption. The above electrolyte consumption rate can be determined based on the capacity and / or resistance after each cycle in the cycle test data.

[0124] As an example, based on the resistance after each cycle in the cycle test data, a relationship curve between the resistance and the number of cycles can be plotted, and the slope of the resistance increase can be calculated based on this relationship curve to infer the electrolyte consumption rate. For example, if the internal resistance increases linearly with the number of cycles, then the change in resistance caused by the electrolyte consumption in each cycle period can be estimated according to the slope of the resistance change, and then the electrolyte consumption rate can be determined.

[0125] As another example, based on the capacity after each cycle in the cycle test data, a relationship curve between the capacity and the number of cycles can be plotted, and the slope of the capacity attenuation can be calculated based on this relationship curve. This slope can be associated with the electrolyte consumption rate because the consumption of the electrolyte is one of the important factors leading to the capacity attenuation. For example, if the capacity attenuates linearly with the number of cycles, the electrolyte consumption rate can be estimated through the slope of the capacity attenuation.

[0126] As yet another example, by comprehensively analyzing the capacity and resistance of each cycle period, a multiple linear regression model can be established, with the number of cycles as the independent variable and the capacity and resistance as the dependent variables. By fitting the model, the capacity attenuation coefficient and the resistance increase coefficient are obtained, and then based on the relationship between these two coefficients and the electrolyte consumption rate, the electrolyte consumption rate is determined. Because this method simultaneously considers the relationship between the capacity and the resistance and the electrolyte consumption rate, the accuracy of estimating the electrolyte consumption rate can be improved.

[0127] In addition to the various examples given above, the electrolyte consumption rate can also be obtained by means of related technologies, which will not be elaborated here.

[0128] After obtaining the electrolyte consumption rate of the sample battery, the ratio between the initial electrolyte filling amount of the sample battery and the electrolyte consumption rate can be calculated. This ratio is the number of cycles required for the initial electrolyte filling amount of the sample battery to be consumed and dried up. The cut-off point corresponding to this number of cycles is used as the third cut-off point for the electrolyte dry-up of the sample battery. Parameters such as capacity, resistance, or voltage corresponding to this number of cycles are obtained from the cycle test data of the sample battery. Based on these parameters corresponding to this number of cycles, the value of the performance parameter corresponding to this number of cycles is calculated, and this value of the performance parameter is used as the performance parameter at the third cut-off point.

[0129] The above process fully considers the influence of the electrolyte on the battery life attenuation, determines the electrolyte consumption rate of the sample battery using the cycle test data, estimates the timing of the electrolyte dry-up of the sample battery, and then determines the performance parameter at the third cut-off point between the final accelerated attenuation stage and the adjacent previous attenuation stage, realizing the rapid and accurate identification of the performance parameter at the cut-off point between the final accelerated attenuation stage and the adjacent previous attenuation stage.

[0130] Through the above method, based on the cycle test data of the sample battery in advance, the performance parameters at the cut-off points between any two adjacent stages in each life attenuation stage of the sample battery are identified. And the second mapping relationship between the battery model and the performance parameters at each cut-off point is stored in advance. In this way, when predicting the life of the battery to be predicted, the corresponding performance parameters at each cut-off point can be directly queried from the second mapping relationship based on the battery model. Then, based on the cycle test data of the battery in the first stage and the performance parameters at each cut-off point queried, the battery life attenuation curve is generated. Here, the first stage can be any life attenuation stage of the battery to be predicted.

[0131] In some embodiments of the present application, the battery life attenuation curve can be specifically generated in the following manner, including: fitting the first life function relationship of the first stage based on the cycle test data of the battery in the first stage; obtaining the life function relationships of the stages other than the first stage in each life attenuation stage included in the battery based on the first life function relationship and the performance parameters at each cut-off point; and plotting the battery life attenuation curve based on the life function relationships of each life attenuation stage included in the battery.

[0132] The cycle test data of the above first stage can be obtained by performing cycle tests on the battery at a preset temperature and the nominal rate of the battery. The meanings of the preset temperature and the nominal rate have been described above and will not be repeated here.

[0133] The first life function relationship in the first stage can be expressed by the following formula (1): ... (1) Wherein, is the remaining life of the battery in the first stage, n is the number of cycles, , , are the coefficients to be identified.

[0134] Based on the cycle test data of the battery in the first stage, multiple groups of (S, n) are obtained. Substituting these multiple groups of (S, n) into formula (1) gives a set of equations. Solving this set of equations yields the values of , , . Substituting the obtained , , into formula (1) gives the life function relationship in the first stage.

[0135] After obtaining the first life function relationship, combining the performance parameters at each demarcation point, the life function relationships of other stages except the first stage in the battery life attenuation stage are obtained, and then the battery life attenuation curve is plotted.

[0136] In the embodiments of the present application, only the cycle test data of the battery in the first stage is needed, without obtaining the cycle test data of each stage in the entire life cycle of the battery, reducing the workload of the cycle test and the amount of cycle test data to be collected, and reducing the cost. By using the cycle test data in the first stage and combining the performance parameters at the demarcation points between adjacent stages in each life attenuation stage of the battery, the battery life attenuation curve can be obtained, which helps to improve the efficiency and accuracy of predicting the life attenuation curve.

[0137] In some embodiments of the present application, the life function relationships of other life attenuation stages except the first stage can be obtained in the following manner, including: Based on the first life function relationship, the slopes of the life attenuation curves of the first stage and the second stage are equal at the first demarcation point between the first stage and the second stage, and the life values of the first stage and the second stage at the first demarcation point are both equal to the performance parameters at the first demarcation point, to obtain the second life function relationship in the second stage; the second stage is any stage adjacent to the first stage among the life attenuation stages included in the battery.

[0138] Since the battery life attenuation is continuous in time, the demarcation point between any two adjacent life attenuation stages in each life attenuation stage of the battery is also the intersection point of the two adjacent life attenuation stages. At this intersection point, the slopes of the life attenuation curves corresponding to the two adjacent stages are equal, and the life values of the two adjacent stages at this intersection point are also the same. Based on this correlation between adjacent life attenuation stages, if the life function relationship of one of the two adjacent life attenuation stages is known, a system of equations can be established based on the same slope and the same life value at the demarcation point to identify the coefficients to be identified in the life function relationship of the unknown stage among the two adjacent life attenuation stages, so as to obtain the life function relationship of the unknown stage.

[0139] As an example, assume that the life function relationship of the above-mentioned first stage is known, and the first stage is the mid-term slow attenuation stage. The battery includes a second stage adjacent to the first stage, and the second stage is the linear attenuation stage. The life function relationship of the second stage can be expressed by the following formula (2): ...(2) In formula (2), is the remaining life of the battery in the second stage, n is the number of cycles, , is the coefficient to be identified.

[0140] Based on the same slope of the first stage and the second stage at the demarcation point, construct the formula: ...(3) In formula (3), represents the derivative of formula (1) at the demarcation point between the first stage and the second stage, and this derivative is equal to the slope of the first stage at this demarcation point.

[0141] Based on the same life value of the first stage and the second stage at the demarcation point, construct the formula: = ...(4) In formula (4), represents the number of cycles at the demarcation point between the first stage and the second stage.

[0142] In formulas (3) and (4), only the coefficient to be identified , is unknown. Solve formulas (3) and (4) to obtain the coefficients , , and substitute them into formula (2) to obtain the life function relationship of the second stage.

[0143] For adjacent life attenuation stages, if the life function relationship of one of the life attenuation stages is known, the life function relationship of the unknown life attenuation stage can be obtained by using the correlation relationship between the adjacent life attenuation stages at their demarcation point. Therefore, for each life attenuation stage included in the battery, after obtaining the life function relationship of any one stage, the life function relationships of all life attenuation stages can be quickly obtained by using the correlation relationship between adjacent life attenuation stages. So, only the cyclic test data of the battery in one life attenuation stage needs to be collected, and the life function relationship of this life attenuation stage is fitted, then the life function relationships of all life attenuation stages of the battery can be obtained, and further the life attenuation curve of the entire life cycle of the battery can be obtained, greatly improving the efficiency of battery life prediction, reducing the amount of data collection required for life prediction, reducing costs, and at the same time improving the accuracy of life prediction.

[0144] To facilitate the understanding of the method for predicting the battery life attenuation curve provided by the embodiments of the present application, an example is given below. As Figure 6 shown, taking the battery to be predicted as a lithium iron phosphate battery as an example, the complete process of generating the life prediction curve of the lithium iron phosphate battery is described.

[0145] S1: Based on the battery model of the battery, determine each life attenuation stage of the battery from the pre-stored first mapping relationship.

[0146] Among them, the first mapping relationship includes the mapping relationship between the battery model and the life attenuation stage.

[0147] S2: Based on the battery model of the battery, determine the performance parameters of the battery at the demarcation point between adjacent stages of each life attenuation stage of the battery from the pre-stored second mapping relationship.

[0148] Among them, the second mapping relationship includes the mapping relationship between the battery model and the performance parameters at each demarcation point.

[0149] S3: Obtain the cyclic test data of the battery in the medium-term slow attenuation stage.

[0150] For lithium iron phosphate batteries of any battery model, they usually at least include an initial rapid attenuation stage and a medium-term slow attenuation stage. In the initial stage of using the lithium iron phosphate battery, the SEI film is relatively thin, and the formation and growth rate of the SEI film are relatively fast, accelerating the consumption of active lithium in the battery, and this stage is the initial rapid attenuation stage. As the use time extends, the structure of the SEI film becomes relatively stable, the growth rate also slows down, and the consumption rate of active lithium also decreases accordingly, and this stage is called the medium-term slow attenuation stage.

[0151] In this example, the life function relationship in the medium-term slow decay stage is determined first for illustration. The battery can be cycled tested at the nominal rate of the battery in an environment of 50°C in the medium-term slow decay stage to obtain the cycle test data of the battery in the medium-term slow decay stage.

[0152] Among them, the medium-term slow decay stage can be the stage entered when the remaining life of the battery reaches a preset value, and this preset value can be represented by performance parameters such as battery health, capacity, energy, energy efficiency, etc. Taking battery health as an example, the value of this preset value can be, but is not limited to, 95% SOH, 93% SOH, etc. In this example, the value of the preset value is taken as 95% SOH.

[0153] S4: Based on the cycle test data of the battery in the medium-term slow decay stage, fit the life function relationship in the medium-term slow decay stage.

[0154] In this example, taking the performance parameter as the state of health (SOH) of the battery, the life function relationship in the medium-term slow decay stage can be expressed as: —— Equation 1 Equation 1 can describe the decay trend of the battery health state in the medium-term slow decay stage, where are parameters to be identified, SOH is the ordinate of the decay curve (which can represent the capacity retention rate), and n is the abscissa of the decay curve (which can represent the number of cycles).

[0155] Substitute multiple groups of data sets of the number of cycles and capacity included in the cycle test data in the medium-term slow decay stage into Equation 1 to fit out Three parameters, that is, the description of the life function relationship in the medium-term slow decay stage is completed. Based on the life function relationship in the medium-term slow decay stage, the life decay curve segment of the battery in the medium-term slow decay stage can be drawn.

[0156] S5: Use the life function relationship in the medium-term slow decay stage and the performance parameters of the battery at the demarcation point between the medium-term slow decay stage and the initial rapid decay stage corresponding to the battery to obtain the life function relationship in the initial rapid decay stage.

[0157] The life function relationship in the initial rapid decay stage can be described as: —— Equation 2 Equation 2 can describe the decay trend of the battery health state in the initial rapid decay stage, where are parameters to be identified.

[0158] Based on the fact that the lifetime decay curves corresponding to the initial rapid decay stage and the intermediate slow decay stage intersect at the demarcation point, the slopes at the demarcation point are equal. The slope of the initial rapid decay stage at the demarcation point is the derivative and the slope of the intermediate slow decay stage at the demarcation point is the derivative to construct the equation: —— Equation 3 Based on the fact that the lifetime values at the demarcation point of the lifetime decay curves corresponding to the initial rapid decay stage and the intermediate slow decay stage are equal, and the number of cycles at the demarcation point is to construct the equation: —— Equation 4 —— Equation 5 Solve Equations 1 - 5 to identify and substitute it into Equation 2 to obtain the lifetime function relationship of the initial rapid decay stage.

[0159] Affected by factors such as the electrolyte filling amount and the lower performance threshold of the battery, the lifetime decay stages of different batteries are different. If it is determined through step S1 that the battery includes only a linear decay stage in addition to the initial rapid decay stage and the intermediate slow decay stage, then steps S6 and S8 are sequentially executed. If the battery includes only a final accelerated decay stage in addition to the initial rapid decay stage and the intermediate slow decay stage, then steps S7 and S8 are sequentially executed. If the battery includes both a linear decay stage and a final accelerated decay stage in addition to the initial rapid decay stage and the intermediate slow decay stage, then steps S6 - S8 are sequentially executed.

[0160] S6: Using the lifetime function relationship of the intermediate slow decay stage and the performance parameters of the battery at the demarcation point between the intermediate slow decay stage and the linear decay stage corresponding to the battery, obtain the lifetime function relationship of the linear decay stage.

[0161] The linear decay stage can be described as: —— Equation 6 where are the parameters to be identified, SOH is the ordinate of the decay curve (representing the capacity retention rate), and n is the abscissa of the decay curve (representing the number of cycles).

[0162] Based on the fact that the lifetime decay curves corresponding to the intermediate slow decay stage and the linear decay stage intersect at the demarcation point, the slopes at the demarcation point are equal. The slope of the intermediate slow decay stage at the demarcation point is expressed as the derivative and the slope of the linear decay stage at the demarcation point is to construct the equation: —— Equation 7 Based on the fact that the life values at the demarcation point of the life decay curves corresponding to the medium-term slow decay stage and the linear decay stage are equal, the number of cycles at the demarcation point is expressed as , construct the equation: —— Equation 8 —— Equation 9 Solve equations 1, 6 - 9 to complete the identification of the parameter , and substitute it into equation 6 to obtain the life function relationship of the linear decay stage.

[0163] S7: Utilize the life function relationship of the linear decay stage and the performance parameters of the battery at the demarcation point between the linear decay stage and the terminal accelerated decay stage corresponding to this battery to obtain the life function relationship of the terminal accelerated decay stage.

[0164] The terminal accelerated decay stage can be described as: —— Equation 10 Among them, is the parameter to be identified, SOH is the ordinate of the decay curve (representing the capacity retention rate), and n is the abscissa of the decay curve (representing the number of cycles).

[0165] Based on the fact that the life decay curves corresponding to the linear decay stage and the terminal accelerated decay stage intersect at the demarcation point, so the slopes at the demarcation point are equal. The slope of the linear decay stage is , and the slope of the terminal accelerated decay stage at the demarcation point can be expressed as the derivative , construct the equation: —— Equation 11 Based on the fact that the life values of the life decay curves corresponding to the linear decay stage and the terminal accelerated decay stage are equal at the demarcation point, the number of cycles at the demarcation point is expressed as , construct the equation: —— Equation 12 —— Equation 13 Solve equations 10 - 13 to complete the identification of the parameter , and substitute it into equation 10 to obtain the life function relationship of the terminal accelerated decay stage.

[0166] S8: Based on the life function relationships of each life decay stage of this battery, respectively plot the decay curve segments of each life decay stage to obtain the life decay curve of the entire life cycle of this battery.

[0167] When the life attenuation stage included in the battery includes an initial rapid attenuation stage, a medium-term slow attenuation stage, a linear attenuation stage, and a final-stage accelerated attenuation stage, the generated life attenuation curve is as Figure 7 shown.

[0168] If the life attenuation stage included in the battery only includes an initial rapid attenuation stage and a medium-term slow attenuation stage, then the generated life attenuation curve will only include Figure 7 the blue curve segment and the red curve segment in, and there are no green and yellow curve segments.

[0169] If the life attenuation stage included in the battery only includes an initial rapid attenuation stage, a medium-term slow attenuation stage, and a linear attenuation stage, then the generated life attenuation curve will only include Figure 7 the blue curve segment, the red curve segment, and the green curve segment in, and there is no yellow curve segment.

[0170] If the life attenuation stage included in the battery only includes an initial rapid attenuation stage, a medium-term slow attenuation stage, and a final-stage accelerated attenuation stage, then the generated life attenuation curve will only include Figure 7 the blue curve segment, the red curve segment, and the yellow curve segment in, and there is no green curve segment, and the red curve segment and the yellow curve segment are continuous curves.

[0171] Figure 6 The prediction process of the battery life attenuation curve shown is only for illustration. Based on the prediction method provided in the foregoing embodiments, Figure 6 the content of each step and the execution order of each step can have other change forms.

[0172] Through Figure 6 the prediction method shown, before generating the life attenuation curve of the battery, it is possible to quickly know based on the battery model what the life attenuation stages of the battery are, and to know the performance parameters at the demarcation points between adjacent life attenuation stages. Knowing these information in advance helps to improve the convenience and accuracy of subsequent life prediction. Only the cycle test data of the battery in the medium-term slow attenuation stage need to be collected in the above prediction process, without collecting the cycle test data of each stage in the entire life cycle of the battery, which greatly reduces the data collection volume, reduces the cost, and improves the processing efficiency. Based on the cycle test data of the medium-term slow attenuation stage, first fit the life function relationship of the medium-term slow attenuation stage, and then based on the correlation relationship between adjacent life attenuation stages at the demarcation points, through simple calculations, the life function relationships of each life attenuation stage of the battery can be quickly obtained, reducing the overall computation amount of life prediction, occupying less computing power resources, and quickly and accurately predicting the life attenuation curve of the battery.

[0173] The descriptions of the various embodiments above tend to emphasize the differences between the various embodiments. Their similarities or resemblances can be referred to each other. For the sake of brevity, they will not be elaborated herein.

[0174] Some embodiments of the present application also provide a prediction device for the battery life attenuation curve, and this device is used to execute the prediction method for the battery life attenuation curve provided in any of the foregoing embodiments. Refer to Figure 8 As shown, this device includes: A first determination module 401, configured to determine each life attenuation stage of the battery based on the battery parameters of the battery; A second determination module 402, configured to respectively determine the performance parameters of the battery at the demarcation points between adjacent stages in each life attenuation stage; A generation module 403, configured to generate a battery life attenuation curve based on the cycle test data of the battery in the first stage and the performance parameters at each demarcation point, where the first stage is any one of the life attenuation stages.

[0175] The first determination module 401 is configured to determine each life attenuation stage of the battery based on the initial electrolyte filling amount and / or the performance lower limit threshold included in the battery parameters; wherein, the performance lower limit threshold is used to characterize that the battery stops being used when the performance parameters of the battery reach the performance lower limit threshold.

[0176] The first determination module 401 is specifically configured to determine the target number of cycles required for the initial electrolyte filling amount to be consumed based on the initial electrolyte filling amount and the preset electrolyte consumption rate of the battery; and determine each life attenuation stage included in the battery based on the target number of cycles.

[0177] The first determination module 401 is specifically configured to, if the target number of cycles is less than or equal to the first number of cycles required for the battery to reach the starting point of the linear attenuation stage, determine that the battery includes an initial rapid attenuation stage, a middle slow attenuation stage, and an end accelerated attenuation stage; if the target number of cycles is greater than the first number of cycles and less than or equal to the second number of cycles required for the battery to reach the end point of the linear attenuation stage, determine that the battery includes an initial rapid attenuation stage, a middle slow attenuation stage, a linear attenuation stage, and an end accelerated attenuation stage; if the target number of cycles is greater than the number of cycles corresponding to the performance lower limit threshold, determine that the first life attenuation stage combination includes an initial rapid attenuation stage, a middle slow attenuation stage, and a linear attenuation stage.

[0178] The first determination module 401 is specifically configured to determine that the battery includes an initial rapid decay stage and a mid-term slow decay stage based on that the performance lower limit threshold is less than or equal to the performance parameter at the starting point when the battery enters the linear decay stage; determine that the battery includes an initial rapid decay stage, a mid-term slow decay stage, and a linear decay stage based on that the performance lower limit threshold is greater than the performance parameter at the starting point and less than or equal to the performance parameter at the end point of the linear decay stage; determine that the battery includes an initial rapid decay stage, a mid-term slow decay stage, a linear decay stage, and a final accelerated decay stage based on that the performance lower limit threshold is greater than the performance parameter at the end point.

[0179] The first determination module 401 is specifically configured to determine the respective life decay stages of the battery based on the first stage combination composed of the respective life decay stages determined based on the initial electrolyte filling amount and the second stage combination composed of the respective life decay stages determined based on the performance lower limit threshold.

[0180] The first determination module 401 is configured to obtain the respective life decay stages of the battery from the first mapping relationship between the battery model and the life decay stage stored in advance based on the battery model included in the battery parameters; wherein, the first mapping relationship is determined based on the initial electrolyte filling amount and / or the performance lower limit threshold corresponding to the battery model, and the performance lower limit threshold is used to characterize that the battery stops being used when the performance parameter of the battery of the battery model reaches the performance lower limit threshold.

[0181] The second determination module 402 is configured to obtain the performance parameters of the battery at the boundary points between adjacent stages in the respective life decay stages from the second mapping relationship between the battery model and the performance parameters at the boundary points stored in advance based on the battery model included in the battery parameters; wherein, the second mapping relationship is determined based on the cycle test data of the sample battery of the battery model.

[0182] The device further includes a construction module for the second mapping relationship, configured to perform a cycle test on the sample battery at the nominal rate of the sample battery at a preset temperature to obtain the cycle test data of the sample battery; determine the respective life decay stages of the sample battery based on the battery parameters of the sample battery; determine the performance parameters at the boundary points between adjacent stages in the respective life decay stages of the sample battery respectively based on the cycle test data; and store the battery model and the performance parameters at the respective boundary points as the second mapping relationship.

[0183] The construction module is specifically configured to fit a curve of the decay slope varying with the battery performance parameter based on the cycle test data; the decay slope is used to characterize the decay amount of the battery performance parameter corresponding to a preset number of cycles; and determine the performance parameters at the boundary points between adjacent stages in the respective life decay stages of the sample battery respectively based on the variation curve.

[0184] A construction module, specifically used to determine the performance parameters at the first demarcation point between the initial rapid decay stage and the intermediate slow decay stage based on the change curve when the sample battery includes an initial rapid decay stage and an intermediate slow decay stage; to determine the performance parameters at the second demarcation point between the linear decay stage and the adjacent previous decay stage based on the change curve when the sample battery includes a linear decay stage; to determine the electrolyte consumption rate of the sample battery based on the cycle test data when the sample battery includes a final accelerated decay stage; and to determine the third demarcation point of the electrolyte dry-out of the sample battery based on the electrolyte consumption rate and the initial electrolyte filling amount of the sample battery, and use the performance parameters at the third demarcation point as the performance parameters at the demarcation point between the final accelerated decay stage and the adjacent previous decay stage.

[0185] A generation module 403, configured to fit the life function relationship of the first stage based on the cycle test data of the battery in the first stage; to obtain the life function relationships of the stages other than the first stage in each life decay stage included in the battery based on the first life function relationship and the performance parameters at each demarcation point; and to draw the life decay curve of the battery based on the life function relationships of each life decay stage included in the battery.

[0186] The generation module 403 is specifically configured to obtain the second life function relationship of the second stage based on the first life function relationship, the slopes of the life decay curves of the first stage and the second stage being equal at the first demarcation point between the first stage and the second stage, and the life values of the first stage and the second stage being equal to the performance parameters at the first demarcation point; the second stage being any stage adjacent to the first stage among the life decay stages included in the battery.

[0187] The device for predicting the battery life decay curve provided by the embodiments of the present application and the method provided by the embodiments of the present application are based on the same inventive concept and have the same beneficial effects as the method adopted, run, or implemented by it.

[0188] The descriptions of the above embodiments tend to emphasize the differences between the embodiments, and their similarities or similarities can be referred to each other. For the sake of brevity, they will not be elaborated herein.

[0189] Some other embodiments of the present application provide an electronic device, which includes a memory, a processor, and a computer program stored on the memory and executable on the processor. The processor executes the program to implement the method for predicting the battery life decay curve in any of the above embodiments.

[0190] As Figure 9As shown, the electronic device 60 may include: a processor 600, a memory 601, a bus 602, and a communication interface 603. The processor 600, the communication interface 603, and the memory 601 are connected through the bus 602. A computer program that can run on the processor 600 is stored in the memory 601. When the processor 600 runs this computer program, it executes the method provided in any of the foregoing embodiments of the present application.

[0191] Among them, the memory 601 may include a high-speed random access memory (RAM: Random Access Memory), and may also include a non-volatile memory, such as at least one disk memory. Through at least one communication interface 603 (which can be wired or wireless), a communication connection is realized between this device network element and at least one other network element, and the Internet, wide area network, local area network, metropolitan area network, etc. can be used.

[0192] The bus 602 may be an ISA bus, a PCI bus, an EISA bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. Among them, the memory 601 is used to store a program. After receiving an execution instruction, the processor 600 executes this program. Any of the methods disclosed in any of the foregoing embodiments of the present application can be applied to the processor 600 or implemented by the processor 600.

[0193] The processor 600 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the integrated logic circuit in the hardware of the processor 600 or by an instruction in software form. The above-mentioned processor 600 may be a general-purpose processor, which may include a central processing unit (CPU for short), a network processor (NP for short), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. It can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or this processor may also be any conventional processor, etc. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as being executed by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software module may be located in a mature storage medium in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. This storage medium is located in the memory 601, and the processor 600 reads the information in the memory 601 and combines its hardware to complete the steps of the above method.

[0194] The electronic device provided by the embodiment of the present application and the method provided by the embodiment of the present application are based on the same inventive concept and have the same beneficial effects as the method adopted, run or implemented by it.

[0195] Some other embodiments of the present application provide a computer-readable storage medium, on which a computer program is stored, and the program is executed by a processor to implement the method of any of the above embodiments.

[0196] The computer-readable storage medium provided by the embodiment of the present application and the method provided by the embodiment of the present application are based on the same inventive concept and have the same beneficial effects as the method adopted, run or implemented by it.

[0197] The embodiment of the present application also provides a computer program product corresponding to the method provided by the foregoing embodiment. The computer program product includes a computer program, and the computer program is executed by a processor to implement the method for predicting the battery life decay curve provided by the foregoing embodiment.

[0198] The computer program product provided by the above embodiment of the present application and the method provided by the embodiment of the present application are based on the same inventive concept and have the same beneficial effects as the method adopted, run or implemented by the application program stored therein.

[0199] The descriptions of the above embodiments tend to emphasize the differences between the embodiments. Their similarities or similarities can be referred to each other. For the sake of brevity, they will not be repeated herein.

[0200] It should be noted that: The term "module" is not intended to be limited to a specific physical form. Depending on the specific application, a module can be implemented as hardware, firmware, software, and / or a combination thereof. In addition, different modules can share common components or even be implemented by the same components. There may or may not be a clear boundary between different modules.

[0201] The algorithms and displays provided herein are not inherently related to any particular computer, virtual device, or other device. Various general-purpose devices can also be used in conjunction with the examples based herein. The structure required to construct such a device is obvious from the above description. In addition, the present application is not directed to any specific programming language. It should be understood that the content of the present application described herein can be implemented using various programming languages, and the description of the specific language above is to disclose the best implementation mode of the present application.

[0202] It should be understood that although the steps in the flowchart of the accompanying drawings are shown sequentially in the direction of the arrows, these steps are not necessarily executed sequentially in the order indicated by the arrows. Unless otherwise clearly stated in this document, there is no strict order restriction for the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or sub-steps or stages of other steps.

[0203] The above embodiments only represent the implementation manners of the present application, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A method for predicting the battery life attenuation curve, characterized in that Including: Determining each life attenuation stage of the battery based on battery parameters of the battery; Respectively determining performance parameters of the battery at a demarcation point between adjacent stages in each of the life attenuation stages; Generating a life attenuation curve of the battery based on cycle test data of the battery in a first stage and the performance parameters at each of the demarcation points, where the first stage is any one of the life attenuation stages.

2. The method according to claim 1, wherein The determining each life attenuation stage of the battery based on battery parameters of the battery includes: Determining each life attenuation stage of the battery based on an initial electrolyte filling amount and / or a performance lower limit threshold included in the battery parameters; Wherein, the performance lower limit threshold is used to characterize that the battery stops being used when the performance parameter of the battery reaches the performance lower limit threshold.

3. The method according to claim 2, characterized in that, The determining each life attenuation stage of the battery based on the initial electrolyte filling amount includes: Determining a target number of cycles required for the initial electrolyte filling amount to be consumed completely based on the initial electrolyte filling amount and a preset electrolyte consumption rate of the battery; Determining each life attenuation stage included in the battery based on the target number of cycles.

4. The method according to claim 3, wherein The determining each life attenuation stage included in the battery based on the target number of cycles includes: If the target number of cycles is less than or equal to a first number of cycles required for the battery to reach a starting point of a linear attenuation stage, determining that the battery includes an initial rapid attenuation stage, a middle slow attenuation stage, and a final accelerated attenuation stage; If the target number of cycles is greater than the first number of cycles and less than or equal to a second number of cycles required for the battery to reach an end point of the linear attenuation stage, determining that the battery includes the initial rapid attenuation stage, the middle slow attenuation stage, a linear attenuation stage, and a final accelerated attenuation stage; If the target number of cycles is greater than the number of cycles corresponding to the performance lower limit threshold, determining that the battery includes the initial rapid attenuation stage, the middle slow attenuation stage, and the linear attenuation stage.

5. The method according to claim 2, wherein The determining each life attenuation stage of the battery based on the performance lower limit threshold includes: Determining that the battery includes an initial rapid attenuation stage and a middle slow attenuation stage based on the performance lower limit threshold being less than or equal to a performance parameter at a starting point where the battery enters the linear attenuation stage; Determining that the battery includes the initial rapid attenuation stage, the middle slow attenuation stage, and a linear attenuation stage based on the performance lower limit threshold being greater than the performance parameter at the starting point and less than or equal to a performance parameter at an end point of the linear attenuation stage; Determining that the battery includes the initial rapid attenuation stage, the middle slow attenuation stage, the linear attenuation stage, and a final accelerated attenuation stage based on the performance lower limit threshold being greater than the performance parameter at the end point.

6. The method according to any one of claims 2-5, characterized in that, The determining each life attenuation stage of the battery based on the initial electrolyte filling amount and the performance lower limit threshold includes: Determine each life attenuation stage of the battery based on a first stage combination composed of each life attenuation stage determined based on the initial electrolyte filling amount and a second stage combination composed of each life attenuation stage determined based on the performance lower limit threshold.

7. The method according to claim 1, wherein Determining each life attenuation stage of the battery based on the battery parameters of the battery includes: Based on the battery model included in the battery parameters, obtain each life attenuation stage of the battery from a first mapping relationship between the battery model and the life attenuation stage stored in advance; Among them, the first mapping relationship is determined based on the initial electrolyte filling amount and / or the performance lower limit threshold corresponding to the battery model, and the performance lower limit threshold is used to characterize that the battery stops being used when the performance parameters of the battery of the battery model reach the performance lower limit threshold.

8. The method according to any one of claims 1-5 and 7, characterized in that Respectively determining the performance parameters of the battery at the demarcation points between adjacent stages in each life attenuation stage includes: Based on the battery model included in the battery parameters, obtain the performance parameters of the battery at the demarcation points between adjacent stages in each life attenuation stage from a second mapping relationship between the battery model and the performance parameters at the demarcation points stored in advance; Among them, the second mapping relationship is determined based on the cycle test data of the sample battery of the battery model.

9. The method according to claim 8, characterized in that The construction process of the second mapping relationship includes: Perform a cycle test on the sample battery at the nominal rate of the sample battery at a preset temperature to obtain the cycle test data of the sample battery; Based on the battery parameters of the sample battery, determine each life attenuation stage of the sample battery; Based on the cycle test data, respectively determine the performance parameters at the demarcation points between adjacent stages in each life attenuation stage of the sample battery; Store the battery model and the performance parameters at each demarcation point as the second mapping relationship.

10. The method according to claim 9, characterized in that, Respectively determining the performance parameters at the demarcation points between adjacent stages in each life attenuation stage of the sample battery based on the cycle test data includes: Based on the cycle test data, fit a curve of the attenuation slope varying with the battery performance parameters; the attenuation slope is used to characterize the attenuation amount of the battery performance parameters corresponding to a preset number of cycles; Based on the curve, respectively determine the performance parameters at the demarcation points between adjacent stages in each life attenuation stage of the sample battery.

11. The method according to claim 10, wherein Respectively determining the performance parameters at the demarcation points between adjacent stages in each life attenuation stage of the sample battery based on the curve includes: In the case where the sample battery includes an initial rapid attenuation stage and a mid-term slow attenuation stage, based on the curve, determine the performance parameters at the first demarcation point between the initial rapid attenuation stage and the mid-term slow attenuation stage; In the case where the sample battery includes a linear attenuation stage, based on the curve, determine the performance parameters at the second demarcation point between the linear attenuation stage and the previous adjacent attenuation stage; When the sample battery includes an end - stage accelerated degradation phase, based on the cyclic test data, determine the electrolyte consumption rate of the sample battery; based on the electrolyte consumption rate and the initial electrolyte filling amount of the sample battery, determine the third demarcation point of electrolyte dry - out of the sample battery, and use the performance parameters at the third demarcation point as the performance parameters at the demarcation point between the end - stage accelerated degradation phase and the adjacent previous degradation phase.

12. The method according to any one of claims 1-5 and 7, characterized in that, The generating the life degradation curve of the battery based on the cyclic test data of the battery in the first stage and the performance parameters at each of the demarcation points includes: Based on the cyclic test data of the battery in the first stage, fit the first life function relationship of the first stage; Based on the first life function relationship and the performance parameters at each of the demarcation points, obtain the life function relationships of the stages other than the first stage in each of the life degradation stages included in the battery; Based on the life function relationships of each of the life degradation stages included in the battery, draw the life degradation curve of the battery.

13. The method according to claim 12, wherein The obtaining the life function relationships of the stages other than the first stage in each of the life degradation stages included in the battery based on the first life function relationship and the performance parameters at each of the demarcation points includes: Based on the first life function relationship, the slopes of the life degradation curves of the first stage and the second stage are equal at the first demarcation point between the first stage and the second stage, and the life values of the first stage and the second stage are both equal to the performance parameters at the first demarcation point, obtain the second life function relationship of the second stage; the second stage is any stage adjacent to the first stage among the life degradation stages included in the battery.

14. A prediction device for a battery life attenuation curve, characterized in that, Includes: A first determination module, configured to determine each life degradation stage of the battery based on the battery parameters of the battery; A second determination module, configured to respectively determine the performance parameters of the battery at the demarcation points of adjacent stages in each of the life degradation stages; A generation module, configured to generate the life degradation curve of the battery based on the cyclic test data of the battery in the first stage and the performance parameters at each of the demarcation points, where the first stage is any stage among each of the life degradation stages.

15. An electronic device, characterized in that, Includes a memory, a processor, and a computer program stored on the memory and executable on the processor, and the processor executes the program to implement the method according to any one of claims 1 - 13.

16. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the method according to any one of claims 1 - 13.

17. A computer program product, comprising a computer program, characterized in that, The computer program is executed by the processor to implement the method according to any one of claims 1 - 13.

Images