Battery life prediction method, related equipment and storage medium

Abstract

The invention discloses a battery life prediction method, related equipment and a storage medium, and the method comprises the steps: carrying out the multiple charging and discharging tests of a battery, obtaining the discharge capacity of the battery obtained through the detection of each charging and discharging test, and each charging and discharging test comprises the charging process of the battery and the discharging process of the battery; determining a target attenuation factor of the battery based on the difference between the discharge capacities of the batteries in different charge and discharge tests, and determining the current health state of the battery based on the statistical value of the discharge capacity of each battery; determining a cycle life relationship of the battery based on the target attenuation factor and the current health state; and based on the cycle life relationship, predicting the number of times of charging and discharging of the battery under the condition that the future health state of the battery reaches the target health state and / or predicting the future health state of the battery after multiple times of charging and discharging. According to the scheme, how many times of charging and discharging of the battery can reach the specific health state can be determined.

Description

Technical Field

[0001] The present application relates to the field of computers, and in particular to a battery life prediction method, related equipment and storage medium. Background Art

[0002] As the number of battery charge and discharge cycles increases, battery performance will decline and capacity will usually decay. When the decay reaches a certain level, there is a risk of battery bulging, lithium deposition, etc. Therefore, it is necessary to predict the battery life. The so-called battery life can be understood as the number of times the battery can be charged and discharged, so as to make avoidance plans and early warning reminders in advance.

[0003] However, it is currently necessary to obtain a large amount of historical usage data to train the deep learning model so that the trained deep learning model can predict the health status of the battery in the future based on the battery usage data in a period of time. However, this method requires a large amount of data to train the model, and the process is relatively cumbersome. Summary of the invention

[0004] The present application at least provides a battery life prediction method, related equipment and storage medium.

[0005] The present application provides a battery life prediction method, comprising: performing multiple charge and discharge tests on a battery to obtain the battery discharge capacity detected in each charge and discharge test, wherein each charge and discharge test includes a charging process for the battery and a discharging process for the battery; determining a target attenuation factor of the battery based on the difference between the battery discharge capacities in different charge and discharge tests, and determining the current health state of the battery based on the statistical value of the discharge capacity of each battery; determining a cycle life relationship of the battery based on the target attenuation factor and the current health state, wherein the cycle life relationship of the battery is used to characterize the correspondence between the number of charge and discharge times of the battery and the current health state, the target attenuation factor, and the health state of the battery; based on the cycle life relationship, predicting the number of charge and discharge times that the battery can perform when the future health state of the battery reaches the target health state and / or predicting the future health state of the battery after multiple charge and discharges.

[0006] In the above scheme, multiple battery discharge capacities are obtained by performing multiple charge and discharge tests on the battery, and then the target attenuation factor of the battery and the battery health status can be determined based on the multiple battery discharge capacities. Based on the target attenuation factor and the current health status, the cycle life relationship of the battery can be determined. Subsequently, the cycle life relationship can be used to determine the number of charge and discharge times that the battery can be charged and discharged before reaching the target health status, or to predict the health status of the battery after multiple charge and discharge times. There is no need to train the deep learning model with a large amount of historical usage data, which simplifies the battery life prediction process.

[0007] In some embodiments, the dependent variable in the cycle life relationship is the number of charge and discharge cycles, and the independent variable of the cycle life relationship is the health state of the battery. The cycle life relationship of the battery is determined based on the target attenuation factor and the current health state, including: obtaining the health state difference between the future health state and the current health state of the battery; using the ratio relationship between the health state difference and the target attenuation factor as the input of the cycle life relationship, and the number of charge and discharge cycles as the output of the cycle life relationship.

[0008] In the above scheme, the target attenuation factor is determined based on the difference between the battery discharge capacity in different charge and discharge tests. Therefore, when the current health state of the battery is known, the future health state of the given battery can be used to determine the number of charge and discharge times that the battery can still perform based on the difference between the future health state and the current health state of the battery and the target attenuation factor, or the future health state of the battery can be determined by the number of charge and discharge times performed by the given battery.

[0009] In some embodiments, obtaining the health status difference between the future health status and the current health status of the battery includes: obtaining a first function value of the future health status of the battery under a monotonically increasing function, a second function value of the current health status under a monotonically increasing function, and a third function value of the target attenuation factor under a monotonically increasing function; taking the difference between the first function value and the second function value as the health status difference, and taking the ratio between the health status difference and the third function value as a ratio relationship.

[0010] In the above scheme, if the future health state in the monotonically increasing function decreases, the first function value decreases and the health state difference increases. Therefore, the number of charge and discharge times that the battery can perform when reaching a certain health state or the future health state of the battery can be determined when the number of charge and discharge times of the battery is specified.

[0011] In some embodiments, the battery discharge capacity obtained by multiple charge and discharge tests includes a first battery discharge capacity, a second battery discharge capacity, and a third battery discharge capacity obtained in sequence, and based on the discharge capacity of each battery, determining the target attenuation factor of the battery includes: taking the ratio of the second battery discharge capacity to the first battery discharge capacity as the first attenuation factor, and taking the ratio of the third battery discharge capacity to the second battery discharge capacity as the second attenuation factor; based on the first attenuation factor and the second attenuation factor, obtaining the target attenuation factor.

[0012] In the above scheme, by obtaining the battery discharge capacity measured in the middle of adjacent charge and discharge tests, the change of the attenuation factor during the adjacent charge and discharge tests can be determined, and by determining the final target attenuation factor based on multiple attenuation factors, the accuracy of the target attenuation factor can be improved.

[0013] In some embodiments, based on the discharge capacity of each battery, a method for determining the current health state of the battery includes: obtaining mathematical statistical values ​​of the first battery discharge capacity, the second battery discharge capacity, and the third battery discharge capacity; and using the ratio between the mathematical statistical values ​​and the battery nominal capacity of the battery as the current health state of the battery.

[0014] In the above scheme, the mathematical statistical value can generally be any value obtained by mathematical statistics, such as the average value, the maximum value, the minimum value, the middle value, etc., and then the ratio between the data statistical value and the battery nominal capacity of the battery is used as the current health state of the battery, which is more accurate than randomly selecting the ratio between a battery discharge capacity and the battery nominal capacity as the current health state of the battery.

[0015] In some embodiments, a battery is subjected to multiple charge and discharge tests to obtain the battery discharge capacity detected in each charge and discharge test, including: obtaining performance parameters of the battery, the performance parameters of the battery include a charge and discharge range, and the charge and discharge range includes an upper cut-off voltage and a lower cut-off voltage of the battery; for each charge and discharge test, the battery is charged to the upper cut-off voltage and the charged battery is discharged to the lower cut-off voltage; and the battery discharge capacity is obtained for each charge and discharge test.

[0016] In the above scheme, the battery discharge capacity of the battery can be determined by first charging the battery to an upper cut-off voltage and then discharging the battery to a lower cut-off voltage.

[0017] In some embodiments, the performance parameters of the battery include a charge and discharge rate, the charge and discharge rate includes a charging rate, and charging the battery to an upper cutoff voltage includes: charging the battery to the upper cutoff voltage using the charging rate; leaving the battery to stand for a first preset time period; charging the battery to the upper cutoff voltage using a small charging rate, the small charging rate being less than the charging rate.

[0018] In the above scheme, by first charging the battery to the upper cut-off voltage using a larger charging rate, the test time can be saved, and subsequently charging the battery to the upper cut-off voltage using a smaller charging rate can ensure that the battery can be fully charged.

[0019] In some embodiments, the performance parameters of the battery include a charge and discharge rate, the charge and discharge rate includes a discharge rate, and discharging the charged battery to a lower cutoff voltage includes: discharging the charged battery to the lower cutoff voltage using the discharge rate; leaving the battery to stand for a second preset time period; discharging the battery to the lower cutoff voltage using a small discharge rate, the small discharge rate being less than the discharge rate.

[0020] In the above scheme, by first discharging the battery to the lower cut-off voltage using a larger discharge rate, the test time can be saved, and subsequently discharging the battery to the lower cut-off voltage using a smaller discharge rate can ensure that the battery can be discharged.

[0021] In some embodiments, for each charge and discharge test, the battery is charged to an upper cutoff voltage and the charged battery is discharged to a lower cutoff voltage, including: for a charging process in a non-first charge and discharge test, in response to the charged battery being discharged to the lower cutoff voltage in the last charge and discharge test and the battery being left at rest for a third preset time period, charging the battery to the upper cutoff voltage; and / or, for a discharging process in each charge and discharge test, in response to the battery being charged to the upper cutoff voltage and the battery being left at rest for a fourth preset time period, discharging the charged battery to the lower cutoff voltage.

[0022] In the above solution, by standing still for the third preset time period, the polarization of the battery during the discharge process can be reduced. In addition, by standing still for the fourth preset time period, the polarization of the battery during the charging process can be reduced.

[0023] In some embodiments, the method also includes: determining a current attenuation factor of the battery based on the battery discharge capacity obtained in the current charge and discharge test and the battery discharge capacity obtained in the previous charge and discharge test; in response to the difference between the current attenuation factor and the historical attenuation factor being greater than the allowed preset difference, determining that the charge and discharge test is to continue, the historical attenuation factor includes the attenuation factor determined from the battery discharge capacity detected in at least two historical charge and discharge tests.

[0024] In the above scheme, if the difference between the current attenuation factor and the historical attenuation factor is large, it means that the attenuation factor is still inaccurate. By continuing to test until the attenuation factor is stable, the attenuation factor determined subsequently is more accurate.

[0025] In some embodiments, in response to a difference between the current decay factor and the historical decay factor being less than or equal to an allowable preset difference, it is determined that the charge-discharge test is stopped.

[0026] In the above scheme, if the difference between the current attenuation factor and the historical attenuation factor is small, it means that the attenuation factor of the battery has tended to be stable. At this time, the target attenuation factor determined based on these attenuation factors is more accurate.

[0027] The present application provides an electronic device, including a charging and discharging component, a processor and a memory, wherein the charging and discharging component can perform multiple charging and discharging tests on a battery; the processor is connected to the memory and the charging and discharging component respectively, and the processor is used to execute program instructions stored in the memory to implement the above-mentioned battery life prediction method.

[0028] The present application provides an electrical device, which includes the above-mentioned electronic device and a battery, and the electronic device is connected to the battery to implement the above-mentioned battery life prediction method.

[0029] The present application provides a computer-readable storage medium having program instructions stored thereon, and when the program instructions are executed by a processor, any of the above-mentioned battery life prediction methods is implemented.

[0030] In the above scheme, multiple battery discharge capacities are obtained by performing multiple charge and discharge tests on the battery, and then the target attenuation factor of the battery and the battery health status can be determined based on the multiple battery discharge capacities. Based on the target attenuation factor and the current health status, the cycle life relationship of the battery can be determined. Subsequently, the cycle life relationship can be used to determine the number of charge and discharge times that the battery can be charged and discharged before reaching the target health status, or to predict the health status of the battery after multiple charge and discharge times. There is no need to train the deep learning model with a large amount of historical usage data, which simplifies the battery life prediction process.

[0031] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings herein are incorporated into the specification and constitute a part of the specification. These drawings illustrate embodiments consistent with the present application and are used together with the specification to illustrate the technical solution of the present application.

[0033] Figure 1 is a flowchart of an embodiment of a battery life prediction method provided by some embodiments; Figure 2 Some embodiments provide Figure 1 Schematic diagram of the sub-process of step S13; Figure 3 Some embodiments provide Figure 1 Schematic diagram of the sub-process of step S11; Figure 4 Some embodiments provide Figure 3 Schematic diagram of the sub-process of step S112; Figure 5 Some embodiments provide Figure 3 Another sub-process diagram of step S112; Figure 6a is a schematic diagram of attenuation factor sizes under different health states provided by some embodiments; Figure 6b is a schematic diagram of test results of a battery life prediction method provided by some embodiments; Figure 7 is a schematic diagram of the structure of an electronic device provided in some embodiments; Figure 8 is a schematic diagram of the structure of an electric device provided in some embodiments; Fig. 9It is a schematic diagram of the structure of a computer-readable storage medium provided in some embodiments. DETAILED DESCRIPTION

[0034] The scheme of the embodiment of the present application is described in detail below in conjunction with the drawings of the specification.

[0035] In the following description, for the purpose of explanation rather than limitation, specific details such as specific subsystem structures, interfaces, and technologies are provided to facilitate a thorough understanding of the present application.

[0036] The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the objects associated before and after are in an "or" relationship. In addition, "many" in this article means two or more than two. In addition, the term "at least one" in this article means any combination of at least two of any one or more of a plurality of, for example, including at least one of A, B, and C, can mean including any one or more elements selected from the set consisting of A, B, and C.

[0037] Battery life assessment plays a great role in reducing the risks during battery use. However, the current method for battery life assessment is still to predict through deep learning models trained with a large amount of training data in advance, which is relatively cumbersome.

[0038] This solution takes into account that the change in the health state of the battery is related to the change in the discharge capacity of the battery, and the change in the capacity of the battery can be represented by the attenuation factor of the battery, so that the battery can be subjected to multiple charge and discharge tests to obtain multiple battery discharge capacities, and then the target attenuation factor of the battery and the health state of the battery can be determined based on the multiple battery discharge capacities, and the cycle life relationship of the battery can be determined based on the target attenuation factor and the current health state. Subsequently, the cycle life relationship can be used to determine the number of charge and discharge times that the battery can be charged and discharged before reaching the target health state, or to predict the health state of the battery after multiple charge and discharge times. The battery life prediction method provided by this solution can predict the life of the battery with only the results of multiple charge and discharge tests, without the need for a large amount of historical usage data to train the deep learning model, thereby simplifying the process of battery life prediction.

[0039] See also Figure 1, the battery life prediction method provided in the present application may include the contents of the following steps S11 to S14. Step S11: Perform multiple charge and discharge tests on the battery to obtain the battery discharge capacity detected in each charge and discharge test. Each charge and discharge test includes a charging process for the battery and a discharging process for the battery. Step S12: Determine the target attenuation factor of the battery based on the difference between the battery discharge capacities in different charge and discharge tests, and determine the current health state of the battery based on the statistical values ​​of the discharge capacity of each battery. Step S13: Determine the cycle life relationship of the battery based on the target attenuation factor and the current health state. Step S14: Based on the cycle life relationship, predict the number of charge and discharge times that the battery can perform when the future health state of the battery reaches the target health state and / or predict the future health state of the battery after multiple charge and discharges.

[0040] The battery described in this embodiment may be a retired battery, and a retired battery may be considered to be a battery whose health state reaches a retired health state, for example, the retired health state may be 85% SOH or 80% SOH or other custom health states. The charge and discharge test may be to charge the battery to full and then discharge the battery to empty. The battery discharge capacity (SOC) may be considered to be the volumetric capacity of the battery that can be discharged. That is, the battery is first charged to full and then the amount of electricity discharged during the process of discharging the battery to empty can be considered to be the battery discharge capacity. The target attenuation factor may characterize the change in the battery discharge capacity before and after the charge and discharge test. The multiple times may be three or more times, and the battery discharge capacity detected by the previous charge and discharge test may vary from the battery discharge capacity detected by the next charge and discharge test, so the target attenuation factor of the battery may be determined by the change in battery capacity detected in different charge and discharge tests. The health state of the battery can be considered as the SOH (State of health) value. The current health state of the battery can be determined by the ratio between the battery discharge capacity and the battery nominal capacity detected in at least one charge and discharge test, for example, the ratio between one of the battery discharge capacity and the battery nominal capacity is used as the current health state of the battery, or the ratio between the mathematical statistical value such as the average value of the discharge capacity of each battery and the battery nominal capacity can also be used as the current health state of the battery. Optionally, the cycle life relationship of the battery is used to characterize the corresponding relationship between the number of charge and discharge times of the battery and the current health state, the target attenuation factor, and the future health state of the battery. The cycle life relationship of the battery can predict the future health state of the battery based on the number of charge and discharge times, or can also predict the number of charge and discharge times of the battery based on the future health state of the battery. Among them, the form of the cycle life relationship of the battery includes but is not limited to a cycle life curve, an equation, etc. Among them, the number of charge and discharge times described in this embodiment can be the number of times the battery is charged to full and discharged to empty, that is, the battery is charged to full and then discharged to empty. The target health state can be any health state of concern, such as a health state corresponding to the end of life.

[0041] In the above scheme, multiple battery discharge capacities are obtained by performing multiple charge and discharge tests on the battery, and then the target attenuation factor of the battery and the battery health status can be determined based on the multiple battery discharge capacities. Based on the target attenuation factor and the current health status, the cycle life relationship of the battery can be determined. Subsequently, the cycle life relationship can be used to determine the number of charge and discharge times that the battery can be charged and discharged before reaching the target health status, or to predict the health status of the battery after multiple charge and discharge times. There is no need to train the deep learning model with a large amount of historical usage data, which simplifies the battery life prediction process.

[0042] In some embodiments, the dependent variable in the cycle life relationship is the number of charge and discharge cycles, and the independent variable in the cycle life relationship is the health status of the battery. Figure 2 The above-mentioned method for determining the cycle life relationship of the battery based on the target attenuation factor and the current health state may include: step S131: obtaining the health state difference between the future health state and the current health state of the battery; step S132: using the ratio relationship between the health state difference and the target attenuation factor as the input of the cycle life relationship, and the number of charge and discharge times as the output of the cycle life relationship.

[0043] The health status difference between the future health status and the current health status of the battery can be directly taking the difference between the future health status and the current health status as the health status difference, or can be taking the ratio between the future health status and the current health status as the health status difference.

[0044] In the above scheme, the target attenuation factor is determined based on the difference between the battery discharge capacity in different charge and discharge tests. Therefore, when the current health state of the battery is known, the future health state of the given battery can be used to determine the number of charge and discharge times that the battery can still perform based on the difference between the future health state and the current health state of the battery and the target attenuation factor, or the future health state of the battery can be determined by the number of charge and discharge times performed by the given battery.

[0045] In some embodiments, obtaining the health status difference between the future health status and the current health status of the battery includes: obtaining a first function value of the future health status of the battery under a monotonically increasing function, a second function value of the current health status under a monotonically increasing function, and a third function value of the target attenuation factor under a monotonically increasing function; taking the difference between the first function value and the second function value as the health status difference, and taking the ratio between the health status difference and the third function value as a ratio relationship.

[0046] The monotonically increasing function includes, but is not limited to, a logarithmic function or other linear function with a number greater than 1 as the base. Exemplarily, a first logarithmic function with the health state of the battery as the true number, a second logarithmic function with the current health state of the battery as the true number, and a third logarithmic function with the target attenuation factor as the true number are determined respectively. The bases of the first logarithmic function, the second logarithmic function, and the third logarithmic function are the same. Based on the first logarithmic function, the second logarithmic function, and the third logarithmic function, based on the target attenuation factor and the current health state, the cycle life relationship of the battery is determined.

[0047] In this embodiment, the cycle life relationship is taken as a cycle life curve as an example. The dependent variable of the cycle life curve can be the health state of the battery, and the independent variable of the cycle life curve can be the number of charge and discharge times of the battery. Among them, the bases of the first logarithmic function, the second logarithmic function and the third logarithmic function include but are not limited to any values ​​such as e and 10. Based on the first logarithmic function, the second logarithmic function and the third logarithmic function, based on the target attenuation factor and the current health state, the way to determine the cycle life relationship of the battery can be to obtain the difference between the function value (first function value) of the first logarithmic function and the function value (second function value) of the second logarithmic function, and use the ratio between the difference and the function value of the third logarithmic function as the input of the cycle life relationship. In other embodiments, the absolute value of the difference between the function value of the second logarithmic function and the function value of the first logarithmic function can also be obtained, and the ratio of the absolute value to the function value (third function value) of the third logarithmic function can be used as the input of the cycle life relationship. The above method for determining the cycle life relationship of the battery based on the first logarithmic function, the second logarithmic function and the third logarithmic function, based on the target attenuation factor and the current health state may include the following steps: subtracting the function value of the first logarithmic function from the function value of the second logarithmic function. The ratio of the result obtained by the subtraction operation to the function value of the third logarithmic function is used as the input of the expression of the cycle life relationship. The output of the expression of the cycle life relationship is the number of charge and discharge times of the battery.

[0048] The expression for determining the cycle life relationship can be referred to formula (1): Formula (1); in, It can represent a point in the future or an end point. Indicates the target health state of the battery, for example, it can indicate the end-of-life point of the battery or the future health state between the current health state and the end-of-life point. Indicates the current health status of the battery, Represents the target attenuation factor. The battery health status is from the current state to the The number of charge and discharge times that can be performed at this time. In formula (1) represents the first function value, represents the second function value, Represents the third function value.

[0049] In the above scheme, if the future health state in the monotonically increasing function decreases, the first function value decreases and the health state difference increases. Therefore, the number of charge and discharge times that the battery can perform when reaching a certain health state or the future health state of the battery can be determined when the number of charge and discharge times of the battery is specified.

[0050] In some embodiments, the independent variable in the cycle life relationship is the number of charge and discharge times, and the dependent variable of the cycle life relationship is the health state of the battery. The above method of determining the cycle life relationship of the battery based on the target attenuation factor and the current health state includes: using the target attenuation factor as the base of the exponential function, and the number of charge and discharge times as the exponent of the exponential function; adjusting the exponential function using the current health state to obtain the cycle life relationship.

[0051] The cycle life relationship provided in this embodiment is different from the cycle life relationship provided by the above formula (1). This embodiment takes the cycle life relationship as a cycle life curve as an example. The dependent variable of the cycle life curve can be the future health state of the battery, and the independent variable of the cycle life curve can be the number of charge and discharge times of the battery. The method of adjusting the exponential function using the current health state can be to use the current health state as the coefficient of the exponential function, or it can be to use the current health state as the coefficient of the exponential function after correction. In the obtained cycle life relationship, the future health state of the battery is used as the output of the cycle life relationship, and the exponential function is used as the input of the equation of the cycle life relationship.

[0052] In the above scheme, by taking the target attenuation factor as the base of the exponential function and the number of charge and discharge times as the exponent of the exponential function, it is possible to determine how the target attenuation factor changes with the number of charge and discharge times. After adjusting the exponential function using the current health status, the cycle life relationship can be made so that the number of charge and discharge cycles that the battery can still achieve can be predicted based on the target health status when the current health status is known.

[0053] In some embodiments, the exponential function is adjusted using the current health state to obtain the cycle-life relationship, including: using the current health state as a coefficient of the exponential function, and using the exponential function as the cycle-life relationship.

[0054] For example, the cycle life relationship can be obtained by referring to formula (2): Formula (2); in, represents the dependent variable, i.e., the future health status of the battery after n times of charge and discharge, Indicates the current health status. represents the target attenuation factor, Indicates the number of charge and discharge times.

[0055] In the above scheme, by taking the current health state as the coefficient of the exponential function and determining the change of the target attenuation factor according to the number of charge and discharge times, the independent variable in the cycle life relationship can be determined when the dependent variable of the cycle life relationship is determined.

[0056] In some embodiments, the battery discharge capacities detected by multiple charge-discharge tests include a first battery discharge capacity, a second battery discharge capacity, and a third battery discharge capacity obtained in sequence. The method for determining the target attenuation factor of the battery based on each battery discharge capacity includes: using the ratio between the second battery discharge capacity and the first battery discharge capacity as the first attenuation factor, and using the ratio between the third battery discharge capacity and the second battery discharge capacity as the second attenuation factor. Based on the first attenuation factor and the second attenuation factor, the target attenuation factor is obtained.

[0057] Optionally, the first battery discharge capacity is obtained before the second battery discharge capacity, and the second battery discharge capacity is obtained before the third battery discharge capacity. Exemplarily, the first battery discharge capacity is detected in the nth charge-discharge test, the second battery discharge capacity is detected in the mth charge-discharge test, and the third battery discharge capacity is detected in the kth charge-discharge test, where n < m < k. Exemplarily, m may be equal to n + 1, and k may be equal to n + 2. The method for obtaining the first attenuation factor can refer to formula (3), and the method for obtaining the second attenuation factor can refer to formula (4).

[0058] Formula (3); Formula (4); Wherein, represents the first battery discharge capacity, represents the second battery discharge capacity, represents the third battery discharge capacity, represents the first attenuation factor, represents the second attenuation factor.

[0059] In some application scenarios, in addition to the first battery discharge capacity, the second battery discharge capacity, and the third battery discharge capacity, there may also be more battery discharge capacities. The number of battery discharge capacities may be the same as the number of charge-discharge tests, or may be less than the number of charge-discharge tests. For example, outliers, that is, discharge capacities with relatively large differences from other discharge capacities, are removed from the multiple battery discharge capacities detected in the charge-discharge tests. For example, the discharge capacity at the beginning of the charge-discharge test of the battery is unstable, and as the charge-discharge test progresses, the subsequent obtained discharge capacities change relatively stably.

[0060] The above-mentioned method of obtaining the target attenuation factor based on the first attenuation factor and the second attenuation factor can be to use one of the first attenuation factor and the second attenuation factor as the target attenuation factor, or to obtain the target attenuation factor after averaging or weighted fusion of the first attenuation factor and the second attenuation factor. Among them, the weight between the first attenuation factor and the second attenuation factor can be preset, for example, it can be set that the weight of the attenuation factor obtained first is less than the weight of the attenuation factor obtained later, that is, the weight of the first attenuation factor can be less than the weight of the second attenuation factor, or in other embodiments, the weight can also be dynamically determined according to the ratio of the first attenuation factor to the second attenuation factor.

[0061] In the above scheme, by obtaining the battery discharge capacity measured in the middle of adjacent charge and discharge tests, the change of the attenuation factor during the adjacent charge and discharge tests can be determined, and by determining the final target attenuation factor based on multiple attenuation factors, the accuracy of the target attenuation factor can be improved.

[0062] In some embodiments, the method of obtaining the target attenuation factor based on the first attenuation factor and the second attenuation factor may include: obtaining a difference between the first attenuation factor and the second attenuation factor. In response to the difference between the first attenuation factor and the second attenuation factor being less than or equal to an allowed preset difference, averaging the first attenuation factor and the second attenuation factor to obtain the target attenuation factor.

[0063] In some application scenarios, if the difference between the first attenuation factor and the second attenuation factor is greater than the allowed preset difference, the battery may continue to be charged and discharged to obtain more attenuation factors until the difference between the attenuation factors is smaller.

[0064] In the above scheme, if the difference between the first attenuation factor and the second attenuation factor is small, it means that the attenuation factor of the battery has tended to be stable. At this time, the target attenuation factor obtained by averaging multiple attenuation factors is more accurate.

[0065] In some embodiments, the method for determining the current health state of the battery based on the discharge capacity of each battery includes: obtaining mathematical statistics of the discharge capacity of the first battery, the discharge capacity of the second battery, and the discharge capacity of the third battery, and using the ratio between the mathematical statistics and the nominal capacity of the battery as the current health state of the battery.

[0066] The mathematical statistical value includes, but is not limited to, any value obtained through mathematical statistics, such as an average value, a maximum value, a minimum value, and a median value. In this embodiment, the mathematical statistical value is taken as an example, namely, an average value.

[0067] In the above scheme, using the ratio between the data statistic and the battery nominal capacity as the current health state of the battery is more accurate than randomly selecting a ratio between a battery discharge capacity and the battery nominal capacity as the current health state of the battery.

[0068] In some embodiments, see Figure 3 , the above step S11 may include the following steps: Step S111: Obtain the performance parameters of the battery. The performance parameters of the battery include the charge and discharge interval, and the charge and discharge interval includes the upper cut-off voltage and the lower cut-off voltage of the battery. Step S112: For each charge and discharge test, charge the battery to the upper cut-off voltage and discharge the charged battery to the lower cut-off voltage. Step S113: Obtain the battery discharge capacity for each charge and discharge test.

[0069] The charge and discharge interval of a battery can be considered as the voltage range of the battery during the charging and discharging process. The upper cut-off voltage is also known as the charge cut-off voltage (Charge Cut-off Voltage): During charging, in order to reduce the damage to the battery caused by overcharging, charging should be stopped when this voltage is reached. The lower cut-off voltage is also known as the discharge cut-off voltage (Discharge Cut-off Voltage): During discharging, in order to reduce the damage to the battery caused by deep discharge, discharging should be stopped when the battery voltage drops to this level. Among them, the charge and discharge intervals of the same battery in different health states are the same. Optionally, for the first charge and discharge test of the battery, the initial voltage of the battery during the charging process may not be the lower cut-off voltage, that is, the first charge may not require the battery to be emptied first. In other embodiments, the charging process in the first charge and discharge test may require the battery to be emptied before charging.

[0070] In the above scheme, the battery discharge capacity of the battery can be determined by first charging the battery to an upper cut-off voltage and then discharging the battery to a lower cut-off voltage.

[0071] In some embodiments, the performance parameters of the battery include the charge and discharge rate, and the charge and discharge rate includes the charge rate. Figure 4 The above-mentioned method of charging the battery to the upper cut-off voltage may include the following steps: step S21: charging the battery to the upper cut-off voltage using the charging rate; step S22: leaving the battery to stand for a first preset time period; step S23: charging the battery to the upper cut-off voltage using a small charging rate. The small charging rate is less than the charging rate.

[0072] Exemplarily, the small charging rate includes but is not limited to one percent of the charging rate or the minimum charging rate allowed for charging. The first preset time period can be 30 minutes or other customized time periods. In some application scenarios, taking the battery's charge and discharge range of 2.5V-3.65V and the charging rate of 0.5C as an example, you can first charge to 3.65V at a constant current of 0.05C, let the battery stand for 30 minutes, and then charge to 3.65V at a constant current of 0.05C. By standing for the first preset time period, the polarization of the battery during the charging process can be reduced.

[0073] In the above scheme, by first charging the battery to the upper cut-off voltage using a larger charging rate, the test time can be saved, and subsequently charging the battery to the upper cut-off voltage using a smaller charging rate can ensure that the battery can be fully charged.

[0074] In some embodiments, the performance parameters of the battery include the charge and discharge rate, and the charge and discharge rate includes the discharge rate. Figure 5 The above-mentioned method of discharging the charged battery to the lower cut-off voltage may include the following steps: step S31: discharging the charged battery to the lower cut-off voltage using a discharge rate; step S32: leaving the battery to stand for a second preset time period; step S33: discharging the battery to the lower cut-off voltage using a small discharge rate. The small discharge rate is less than the discharge rate.

[0075] Exemplarily, the small discharge rate includes but is not limited to one hundredth of the discharge rate or the minimum discharge rate allowed for discharge. The second preset time period may be 30 minutes or other custom time period. The first preset time period and the second preset time period may be the same or different. In some application scenarios, taking the battery charge and discharge range of 2.5V-3.65V and the discharge rate of 0.5C as an example, you can first discharge to 2.5V at a constant current of 0.05C, let the battery stand for 30 minutes, and then discharge to 2.5V at a constant current of 0.05C. By standing for the second preset time period, the polarization of the battery during the discharge process can be reduced.

[0076] In the above scheme, by first discharging the battery to the lower cut-off voltage using a larger discharge rate, the test time can be saved, and subsequently discharging the battery to the lower cut-off voltage using a smaller discharge rate can ensure that the battery can be discharged.

[0077] In some embodiments, for each charge and discharge test, the battery is charged to an upper cutoff voltage and the charged battery is discharged to a lower cutoff voltage, including: for a charging process in a non-first charge and discharge test, in response to the charged battery being discharged to the lower cutoff voltage in the last charge and discharge test and the battery being left at rest for a third preset time period, charging the battery to the upper cutoff voltage; and / or, for a discharging process in each charge and discharge test, in response to the battery being charged to the upper cutoff voltage and the battery being left at rest for a fourth preset time period, discharging the charged battery to the lower cutoff voltage.

[0078] That is, after charging the battery to the upper cut-off voltage, the battery is left to stand for a fourth preset time period before discharging the battery. For the charging process in a non-first charge and discharge test, after discharging the battery to the lower cut-off voltage, the battery is left to stand for a third preset time period before a new round of charging of the battery is performed. The third preset time period and the fourth preset time period may be the same or different, wherein the third preset time period may be less than the first preset time period, and the fourth preset time period may be less than the second preset time period, for example, the third preset time period and the fourth preset time period may both be 5 minutes. In some embodiments, the charging process during the first charge and discharge test may also be to charge the battery after it has been left to stand for a certain period of time, for example, it may also be left to stand for 5 minutes.

[0079] In the above solution, by standing still for the third preset time period, the polarization of the battery during the discharge process can be reduced. In addition, by standing still for the fourth preset time period, the polarization of the battery during the charging process can be reduced.

[0080] In some embodiments, the method also includes: determining a current attenuation factor of the battery based on the battery discharge capacity obtained in the current charge and discharge test and the battery discharge capacity obtained in the previous charge and discharge test; in response to the difference between the current attenuation factor and the historical attenuation factor being greater than the allowed preset difference, determining that the charge and discharge test is to continue, the historical attenuation factor includes the attenuation factor determined from the battery discharge capacity detected in at least two historical charge and discharge tests.

[0081] Exemplarily, the current attenuation factor is determined based on the battery discharge capacity detected in the nth charge and discharge test and the battery discharge capacity detected in the n-1th charge and discharge test, and the historical attenuation factor can be determined based on the battery discharge capacity detected in the n-1th charge and discharge test and the battery discharge capacity detected in the n-2th charge and discharge test. If three charge and discharge tests have been performed, and the difference between the current attenuation factor and the historical attenuation factor is greater than the allowed preset difference, it is determined that a fourth charge and discharge test is required. In some application scenarios, the allowed preset difference can be set according to demand. In some application scenarios, the allowed preset difference can be determined based on the attenuation factors obtained from multiple battery tests in the same health state, for example, the respective attenuation factors of different batteries determined in adjacent charge and discharge tests are determined separately, and the maximum difference in the attenuation factors of different batteries is used as the allowed preset difference. In other application scenarios, the allowable preset difference can also be determined based on the attenuation factors obtained from battery tests in multiple different health states. The two attenuation factors of batteries in different health states obtained in at least three charge and discharge tests can be determined respectively, and an attenuation factor difference is determined for each battery, and the maximum attenuation factor difference or the average value of each attenuation factor difference is used as the allowable preset difference. In some application scenarios, at least two attenuation factors obtained from at least three charge and discharge tests of batteries on the verge of being scrapped can be determined, for example, the maximum attenuation factor difference or the average value of each attenuation factor difference is used as the allowable preset difference.

[0082] In the above scheme, if the difference between the current attenuation factor and the historical attenuation factor is large, it means that the attenuation factor is still inaccurate. By continuing to test until the attenuation factor is stable, the attenuation factor determined subsequently is more accurate.

[0083] Please refer to Figure 6a , the attenuation factor of the battery's health state SOH gradually stabilizes after it is less than 0.8SOH, and this health state reaches 85%SOH or 80%SOH, which is also a retired battery. Therefore, the cycle life of retired batteries can be determined by obtaining their attenuation factors. Of course, due to errors in the test process, the attenuation factors determined in different charge and discharge test processes may vary greatly, so you can choose to perform more charge and discharge tests on the battery until the error between the attenuation factors is small, and then determine the target attenuation factor by averaging or statistical median.

[0084] In some embodiments, in response to a difference between the current decay factor and the historical decay factor being less than or equal to an allowable preset difference, it is determined that the charge-discharge test is stopped.

[0085] In the above scheme, if the difference between the current attenuation factor and the historical attenuation factor is small, it means that the attenuation factor of the battery has tended to be stable. At this time, the target attenuation factor determined based on these attenuation factors is more accurate.

[0086] In some embodiments, the battery may be a retired battery, for example, a lithium iron phosphate (LFP) battery. The battery life prediction method provided in this embodiment may further include the following steps: first, perform multiple charge and discharge tests on the battery. Each charge and discharge test may include the following steps: First, obtain the charge and discharge range, nominal capacity, and charge and discharge rate of the retired battery. Taking LFP cells as an example, assume that the charge and discharge range of the retired battery is 2.5V-3.65V, the charge rate is 0.5C, and the discharge rate is 0.5C.

[0087] For the charging process in each charge and discharge test: 1. Let the battery stand for 5 minutes; 2. Charge to 3.65V with 0.5C constant current; 3. Let the battery stand for 30 minutes; 4. Charge to 3.65V with 0.05C constant current.

[0088] For the discharge process in each charge and discharge test: 1. Let the battery stand for 5 minutes; 2. Discharge at 0.5C constant current to 2.5V; 3. Let the battery stand for 30 minutes; 0.05C constant current discharge value is 2.5V.

[0089] The charge and discharge test is repeated at least three times to obtain at least three battery discharge capacities. The number of repetitions of the charge and discharge test can be determined based on the stability of the attenuation factor. If the difference between the two attenuation factors determined by at least three battery discharge capacities is less than or equal to the allowed preset difference, the attenuation factor is considered stable. Otherwise, the attenuation factor is considered unstable and needs to be tested again. In this embodiment, three charge and discharge tests are performed on the battery as an example. The first battery discharge capacity, the second battery discharge capacity, and the third battery discharge capacity are detected to determine the first attenuation factor and the second attenuation factor, respectively. The specific determination method is as described above and will not be repeated here.

[0090] The discharge capacities of the batteries detected are averaged, and the ratio between the average value and the nominal capacity of the battery is taken as the current health state of the battery.

[0091] Since the battery has decayed to a certain extent after a long period of operation, generally below 85%, the battery decay factor is relatively stable and is considered unchanged. The determined cycle life relationship is shown in the above formula (1) or formula (2).

[0092] The test results of the battery life prediction method provided in this embodiment can be referred to as Figure 6bThe battery was charged and discharged multiple times in an environment of 45°C, and the health status of the battery detected was basically consistent with the predicted results. Figure 6b The solid line in the middle represents the actual measured value, and the dotted line represents the predicted value. Specifically, it includes the results of three cycles of charge and discharge measurement after the battery health status reaches 85% SOH.

[0093] See also Figure 7 The electronic device 40 provided in the embodiment of the present application includes a memory 41, a processor 42 and a charge-discharge component 43, and the charge-discharge component 43 can perform multiple charge-discharge tests on the battery; the processor 42 is connected to the memory 41 and the charge-discharge component 43 respectively, and the processor 42 is used to execute the program instructions stored in the memory 41 to implement the steps in any of the above-mentioned battery life prediction method embodiments. In a specific implementation scenario, the electronic device 40 may include but is not limited to: vehicles, monitoring equipment, microcomputers, servers, and in addition, the electronic device 40 may also include carrier devices such as laptops and tablet computers, which are not limited here.

[0094] The charge and discharge assembly 43 may include a charge and discharge circuit, wherein the charge and discharge assembly 43 may also be used to record the discharge capacity of the battery during each charge and discharge process.

[0095] Specifically, the processor 42 is used to control itself and the memory 41 to implement the steps in any of the above-mentioned battery life prediction method embodiments. The processor 42 can also be called a CPU (Central Processing Unit). The processor 42 may be an integrated circuit chip with signal processing capabilities. The processor 42 can also be a general-purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application-specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field-programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. In addition, the processor 42 can be implemented by an integrated circuit chip.

[0096] See also Figure 8 The present application provides an electrical device 10, which includes the above-mentioned electronic device 40 and a battery 50, and the electronic device 40 is connected to the battery 50 to implement the above-mentioned battery life prediction method.

[0097] The electrical device 10 can be used for electrical devices that use the battery 50 as a power source or various energy storage systems that use the battery 50 as an energy storage element. That is, the battery 50 can be a power battery or an energy storage battery. The electrical device 10 can be a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, an energy storage container, and the like. Among them, the electric toy can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like, and the spacecraft can include airplanes, rockets, space shuttles, and spacecrafts, and the like.

[0098] The charging and discharging assembly (not shown) of the electronic device 40 is connected to the battery 50 so that the charging and discharging assembly can perform charging and discharging tests on the battery.

[0099] See also Fig. 9 , Fig. 9 The computer-readable storage medium 60 has program instructions 61 stored thereon, and when the program instructions 61 are executed by a processor, the steps in any of the above-mentioned battery life prediction method embodiments are implemented.

[0100] In some embodiments, the functions or modules included in the device provided by the embodiments of the present disclosure can be used to execute the method described in the above method embodiments. The specific implementation can refer to the description of the above method embodiments, and for the sake of brevity, it will not be repeated here.

[0101] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other, and for the sake of brevity, they will not be repeated herein.

[0102] In the several embodiments provided in the present application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device implementation described above is only schematic. For example, the division of modules or units is only a logical function division. There may be other division methods in actual implementation. For example, units or components can be combined or integrated into another system, or some features can be ignored or not executed. In another image position, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0103] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit. If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or part of the contribution to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor (processor) to perform all or part of the steps of each implementation method of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program code.

Claims

1. A battery life prediction method, characterized in that: include: Perform multiple charge and discharge tests on the battery to obtain the battery discharge capacity detected by each charge and discharge test, wherein each charge and discharge test includes a charging process of the battery and a discharging process of the battery; Determining a target attenuation factor of the battery based on a difference between discharge capacities of the battery in different charge and discharge tests, and determining a current health state of the battery based on a statistical value of the discharge capacity of each of the batteries; Determining a cycle life relationship of the battery based on the target attenuation factor and the current state of health; Based on the cycle-life relationship, the number of charge and discharge times that the battery can perform when the future health state of the battery reaches the target health state is predicted and / or the future health state of the battery after multiple charge and discharge processes is predicted.

2. The battery life prediction method according to claim 1, characterized in that: The dependent variable in the cycle life relationship is the number of charge and discharge times, the independent variable in the cycle life relationship is the future health state of the battery, and determining the cycle life relationship of the battery based on the target attenuation factor and the current health state includes: Obtaining a health state difference between a future health state of the battery and the current health state; The ratio relationship between the health state difference and the target attenuation factor is used as the input of the cycle life relationship, and the number of charge and discharge times is used as the output of the cycle life relationship.

3. The battery life prediction method according to claim 2, characterized in that: The obtaining a health state difference between the future health state of the battery and the current health state includes: Obtaining a first function value of the future health state of the battery under a monotonically increasing function, a second function value of the current health state under a monotonically increasing function, and a third function value of the target attenuation factor under the monotonically increasing function; The difference between the first function value and the second function value is taken as the health state difference, and the ratio between the health state difference and the third function value is taken as the ratio relationship.

4. The battery life prediction method according to any one of claims 1 to 3, characterized in that: The battery discharge capacity obtained by the multiple charge and discharge tests includes a first battery discharge capacity, a second battery discharge capacity, and a third battery discharge capacity obtained in sequence, and the determining of the target attenuation factor of the battery based on the difference between the battery discharge capacities in different charge and discharge tests includes: Using the ratio of the discharge capacity of the second battery to the discharge capacity of the first battery as a first attenuation factor, and using the ratio of the discharge capacity of the third battery to the discharge capacity of the second battery as a second attenuation factor; The target attenuation factor is obtained based on the first attenuation factor and the second attenuation factor.

5. The battery life prediction method according to claim 4, characterized in that: The determining the current health state of the battery based on the statistical value of the discharge capacity of each of the batteries includes: Obtaining mathematical statistics of the first battery discharge capacity, the second battery discharge capacity, and the third battery discharge capacity; The ratio between the mathematical statistic value and the nominal capacity of the battery is used as the current health state of the battery.

6. The battery life prediction method according to any one of claims 1 to 3, characterized in that: The method of performing multiple charge and discharge tests on the battery to obtain the battery discharge capacity detected by each charge and discharge test includes: Acquire performance parameters of the battery, wherein the performance parameters of the battery include a charge and discharge interval, and the charge and discharge interval includes an upper cut-off voltage and a lower cut-off voltage of the battery; For each of the charge and discharge tests, the battery is charged to the upper cut-off voltage and the charged battery is discharged to the lower cut-off voltage; The battery discharge capacity of each charge and discharge test is obtained.

7. The battery life prediction method according to claim 6, characterized in that: The performance parameter of the battery includes a charge and discharge rate, and the charge and discharge rate includes a charge rate. Charging the battery to the upper cut-off voltage includes: Charging the battery to the upper cut-off voltage using the discharge rate; Allowing the battery to stand for a first preset period of time; The battery is charged to the upper cut-off voltage using a small charging rate, wherein the small charging rate is less than the charging rate.

8. The battery life prediction method according to claim 6, characterized in that: The performance parameter of the battery includes a charge and discharge rate, the charge and discharge rate includes a discharge rate, and discharging the charged battery to the lower cut-off voltage includes: Discharging the charged battery to the lower cut-off voltage using the discharge rate; leaving the battery to rest for a second preset period of time; The battery is discharged to the lower cut-off voltage using a small discharge rate, wherein the small discharge rate is less than the discharge rate.

9. The battery life prediction method according to claim 6, characterized in that: For each of the charge and discharge tests, charging the battery to the upper cut-off voltage and discharging the charged battery to the lower cut-off voltage comprises: For a charging process in a non-first charge and discharge test, in response to the battery being discharged to the lower cut-off voltage in the last charge and discharge test and the battery being left to rest for a third preset time period, charging the battery to the upper cut-off voltage is performed; And / or, for the discharging process in each charge and discharge test, in response to the battery being charged to the upper cut-off voltage and the battery being left to stand for a fourth preset time period, discharging the charged battery to the lower cut-off voltage is performed.

10. The battery life prediction method according to claim 6, characterized in that: The method further comprises: Determine a current attenuation factor of the battery based on the battery discharge capacity detected in the current charge and discharge test and the battery discharge capacity detected in the previous charge and discharge test; In response to a difference between the current attenuation factor and the historical attenuation factor being greater than an allowable preset difference, it is determined that the charge and discharge test is continued, wherein the historical attenuation factor includes an attenuation factor determined from a battery discharge capacity detected in at least two historical charge and discharge tests.

11. The battery life prediction method according to claim 10, characterized in that: In response to a difference between the current attenuation factor and the historical attenuation factor being less than or equal to an allowable preset difference, it is determined that the charge-discharge test is stopped.

12. An electronic device, characterized in that: The electronic device comprises: A charge and discharge assembly, which can perform multiple charge and discharge tests on the battery; A processor and a memory, wherein the processor is connected to the memory and the charging and discharging assembly respectively, and the processor is used to execute program instructions stored in the memory to implement the battery life prediction method according to any one of claims 1 to 11.

13. An electrical device, characterized in that: The electrical device comprises the electronic device as claimed in claim 12 and a battery, and the electronic device is connected to the battery to implement the battery life prediction method as claimed in any one of claims 1 to 11.

14. A computer-readable storage medium having program instructions stored thereon, characterized in that: When the program instructions are executed by a processor, the battery life prediction method according to any one of claims 1 to 11 is implemented.

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