Battery risk early warning method, device, equipment, medium and program product

Abstract

The invention provides a battery risk early warning method, device and equipment, a medium and a program product, and belongs to the technical field of batteries. The battery risk early warning method comprises the steps of performing first mode charging on a to-be-detected battery in a preset electric quantity, and obtaining first charging data of the to-be-detected battery in the first mode charging; performing second mode charging on the to-be-tested battery charged in the first mode, and acquiring second charging data of the to-be-tested battery in the second mode charging; based on the first charging data and the second charging data, determining a current early warning value of the to-be-detected battery; and determining that the to-be-detected battery is in a risk state in response to the condition that the current early warning value and the historical early warning value of the to-be-detected battery meet a preset early warning condition. According to the battery risk early warning method, the calendar life risk of the battery can be quickly evaluated.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery risk warning method, device, equipment, medium and program product. Background Art

[0002] Energy conservation and emission reduction are the key to sustainable social development. Electric vehicles have become an important part of the sustainable development of the automotive industry due to their advantages in energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in their development.

[0003] The calendar life of a battery refers to the performance degradation of a battery due to the passage of time when the battery is not in use. This is a natural degradation process that is independent of the frequency of use and is mainly caused by chemical reactions and material aging inside the battery. How to quickly assess the risk of calendar life has a crucial impact on the use and deployment of batteries. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems in the background technology. To this end, one purpose of the present application is to provide a battery risk warning method, device, equipment, medium and program product to quickly evaluate the battery calendar life risk.

[0005] An embodiment of the first aspect of the present application provides a battery risk warning method, including: performing a first mode charging on a battery to be tested at a preset power level, and obtaining first charging data of the battery to be tested in the first mode charging; performing a second mode charging on the battery to be tested after being charged in the first mode, and obtaining second charging data of the battery to be tested in the second mode charging; determining a current warning value of the battery to be tested based on the first charging data and the second charging data; and determining that the battery to be tested is in a risk state in response to the current warning value and the historical warning value of the battery to be tested satisfying a preset warning condition.

[0006] In the technical solution of the embodiment of the present application, the first charging data and the second charging data of the battery to be tested are obtained through the first mode charging and the second mode charging, and then the current warning value is determined, and according to the current warning value and the historical warning value, it is determined whether the battery to be tested is currently in a risky state. It is possible to quickly determine whether the battery has a calendar life risk without going through the entire calendar test cycle, that is, to quickly obtain the test risk, identify abnormal batteries with risks in advance, and thus intercept the risky batteries in time to facilitate further improvement thereof, which greatly shortens the calendar life test time, is beneficial to improving the efficiency of battery testing and research and development, and saves testing resources.

[0007] In some embodiments, the first mode charging of the battery under test at a preset power level includes: based on a first charging rate, constant current charging of the battery under test at a preset power level until the voltage of the battery under test reaches a maximum voltage; wherein the first charging rate A1 satisfies: 0.1Cn A1 Cn is a preset capacity value or the remaining capacity of the battery to be tested measured in the previous warning value determination process.

[0008] By performing constant current charging on the battery to be tested at the first charging rate, the charging current can be kept at the maximum allowable value, and the battery power can be quickly charged to a certain level, thereby achieving efficient and fast charging. At the same time, the control logic of constant current charging is simple, easy to implement, and low in cost. At the same time, by reasonably setting the first charging rate, a lower discharge current can be used to reduce the pressure of the chemical reaction inside the battery, reduce the loss of electrode materials, and extend the life. At the same time, the polarization reaction inside the battery can be reduced, the charging efficiency can be improved, and the safety of the battery can be effectively improved.

[0009] In some embodiments, the second mode charging is performed on the battery to be tested after being charged in the first mode, including: performing constant voltage charging on the battery to be tested after being charged in the first mode until the current of the battery to be tested reaches the cut-off current; wherein the cut-off current B satisfies , Cn is the preset capacity value or the remaining capacity of the battery to be tested measured in the previous warning value determination process.

[0010] By using constant voltage charging after constant current charging until the end of charging, overcharging can be avoided, the battery can be protected, and the battery life can be extended. At the same time, by setting the cut-off current reasonably, the battery can be ensured to be fully charged, which helps to obtain the accuracy of the current remaining capacity of the battery in the fully charged state, while improving safety and optimizing charging efficiency.

[0011] In some embodiments, based on the first charging data and the second charging data, the current warning value of the battery to be tested is determined, including: based on the first charging data, determining the differential voltage curve of the battery to be tested; based on the differential voltage curve, determining the first peak moment, wherein the first peak moment is used to characterize the peak moment when the negative electrode material of the battery to be tested undergoes a phase transition; based on the first peak moment, the first charging data and the second charging data, determining the current warning value of the battery to be tested.

[0012] In this embodiment, the differential voltage curve can be determined through the first charging data, and the current warning value can be obtained according to the differential voltage curve, which can accurately reflect the changes in negative electrode lithium deposition, and thus can play an accurate warning role, which is beneficial to the effectiveness of risk status judgment.

[0013] In some embodiments, determining the first peak moment based on the differential voltage curve includes: determining the occurrence time of the peak in the differential voltage curve within the first preset state of charge range as the first peak moment, wherein the first preset state of charge range SOC1 satisfies: 50% SOC1 .

[0014] By limiting the first preset state of charge range, this embodiment can accurately find the peak moment when the negative electrode material undergoes phase transformation in the differential voltage curve, that is, accurately obtain the first peak moment.

[0015] In some embodiments, based on the first peak moment, the first charging data and the second charging data, the current warning value of the battery to be tested is determined, including: based on the first charging data, determining the first amount of electricity charged into the battery to be tested from the first peak moment to the first charging end moment of the first mode charging; based on the second charging data, determining the second amount of electricity charged into the battery to be tested from the first charging end moment to the second charging end moment of the second mode charging; and determining the ratio of the first amount of electricity to the second amount of electricity as the current warning value of the battery to be tested.

[0016] The current warning value can be obtained through this embodiment, and the current warning value can be used to accurately and effectively reflect the risk status of the battery to be tested.

[0017] In some embodiments, in response to a current warning value and a historical warning value of the battery to be tested satisfying a preset warning condition, determining that the battery to be tested is in a risky state includes: determining a warning data set based on the current warning value and the historical warning values ​​of the battery to be tested, wherein the warning data set includes each warning value of the battery to be tested determined in chronological order; in response to a continuous decrease in the warning value in the warning data set, and the decrease in the warning value becomes larger successively, determining that the battery to be tested is in a risky state.

[0018] This embodiment can accurately determine that the battery is in a risky state by determining that the warning value continuously decreases and the decrease amplitude gradually increases, thereby improving the accuracy of the risk warning.

[0019] In some embodiments, in response to a warning value continuously decreasing in a warning data set, and the magnitude of the decrease in the warning value becomes larger successively, it is determined that the battery to be tested is in a risk state, including: in response to a warning value decreasing for the first time in the warning data set, and the magnitude of the decrease in the warning value meets a first threshold, it is determined that the battery to be tested is in a first-level warning state; in response to a warning value decreasing twice in a row in the warning data set, and the magnitude of the decrease in the warning value becomes larger successively, it is determined that the battery to be tested is in a second-level warning state; in response to a warning value decreasing three times in a row in the warning data set, and the magnitude of the decrease in the warning value becomes larger successively, it is determined that the battery to be tested is in a third-level warning state, wherein the third-level warning state is used to characterize that the battery to be tested is in a risk state.

[0020] In this embodiment, a three-level warning mechanism can be used to implement a step-by-step warning, quickly and accurately determine whether the battery is in a risky state, and improve the accuracy of risk warning.

[0021] In some embodiments, the method further includes: discharging the battery to be tested in a first mode until the power of the battery to be tested reaches a preset power; wherein the preset power E satisfies, E0, E0 is the rated capacity of the battery to be tested.

[0022] In this embodiment, the power of the battery to be tested can be reduced by discharging in the first mode, thereby increasing the amount of subsequent first charging data and second charging data, so as to accurately analyze the risk status of the battery.

[0023] In some embodiments, performing a first mode discharge on the battery to be tested includes: performing a constant current discharge on the battery to be tested based on a first discharge rate; wherein the first discharge rate D1 satisfies: D1 , Cn is the preset capacity value or the remaining capacity of the battery to be tested measured in the previous warning value determination process.

[0024] In this embodiment, constant current discharge has the advantages of stable current, reliable data, and simple control. At the same time, by reasonably setting the first discharge rate, the battery life can be extended, the discharge capacity can be increased, the influence of internal resistance can be reduced, and the safety can be improved.

[0025] In some embodiments, the method also includes: in response to the current warning value and the historical warning value of the battery to be tested not satisfying the preset warning condition, determining the current remaining capacity of the battery to be tested; in response to the current remaining capacity not decaying to the preset state or the total test time of the battery to be tested not reaching the preset time, storing the battery to be tested at high temperature; and executing the process of determining the next warning value of the battery to be tested.

[0026] In this embodiment, when no risk state occurs, the calendar life test can continue to be performed, and calendar aging can be performed on batteries that do not present a risk to obtain the calendar life of the battery.

[0027] In some embodiments, determining the current remaining capacity of the battery to be tested includes: performing a second mode discharge on the battery to be tested until the voltage of the battery to be tested reaches a minimum voltage, and obtaining first discharge data of the battery to be tested in the second mode discharge; and determining the current remaining capacity of the battery to be tested based on the first discharge data.

[0028] By discharging the battery to be tested to the minimum voltage through the first mode discharge, the current remaining capacity of the battery to be tested can be accurately obtained, and overcharging can be prevented, which is beneficial to the life and safety of the battery.

[0029] In some embodiments, performing a second mode discharge on the battery to be tested includes: performing a constant current discharge on the battery to be tested based on a second discharge rate; wherein the second discharge rate D2 satisfies: D2 , Cn is the preset capacity value or the remaining capacity of the battery to be tested measured in the previous warning value determination process.

[0030] Constant current discharge has the advantages of stable current, reliable data and simple control. It can accurately measure the remaining capacity of the battery. At the same time, by reasonably setting the second discharge rate, it can extend the battery life, increase the discharge capacity, reduce the influence of internal resistance and improve safety.

[0031] In some embodiments, after the battery to be tested is discharged in the second mode until the power of the battery to be tested reaches the minimum voltage, the method further includes: charging the battery to be tested in the third mode until the battery to be tested reaches a second preset state of charge; wherein the second preset state of charge SOC2 satisfies: 90% SOC2 .

[0032] By discharging in the second mode, after measuring the current remaining capacity, and before storage, the battery to be tested can be charged so that it is fully charged or nearly fully charged, and the battery SOC can be adjusted for aging testing, that is, for the next round of testing.

[0033] In some embodiments, the third mode charging of the battery to be tested includes: performing constant current charging of the battery to be tested based on a second charging rate; wherein the second charging rate A2 satisfies: 0 A2 Cn is a preset capacity value or the remaining capacity of the battery to be tested measured in the previous warning value determination process.

[0034] In this embodiment, by performing constant current charging on the battery to be tested at the second charging rate, the charging current can be kept at the maximum allowable value, and the battery can be quickly charged to full charge, thereby achieving efficient and fast charging. At the same time, the control logic of constant current charging is simple, easy to implement, low cost, and safe and reliable.

[0035] An embodiment of the second aspect of the present application provides a battery risk warning device, including: a first acquisition module, used to perform a first mode charging on a battery to be tested at a preset power level, and obtain first charging data of the battery to be tested in the first mode charging; a second acquisition module, used to perform a second mode charging on the battery to be tested after being charged in the first mode, and obtain second charging data of the battery to be tested in the second mode charging; a first determination module, used to determine a current warning value of the battery to be tested based on the first charging data and the second charging data; and a second determination module, used to determine that the battery to be tested is in a risk state in response to the current warning value and the historical warning value of the battery to be tested satisfying a preset warning condition.

[0036] An embodiment of the third aspect of the present application provides a computing device, including: at least one processor; and at least one memory communicatively connected to the at least one processor, the at least one memory storing instructions, which, when executed individually or collectively by the at least one processor, enable the computing device to execute the battery risk warning method in the above embodiment.

[0037] An embodiment of the fourth aspect of the present application provides a computer-readable storage medium storing instructions, which, when executed individually or collectively by one or more processors of a computing device, enable the computing device to execute the battery risk warning method in the above embodiment.

[0038] An embodiment of the fifth aspect of the present application provides a computer program product, including instructions, which, when executed individually or collectively by one or more processors of a computing device, enable the computing device to execute the battery risk warning method in the above embodiment.

[0039] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0041] Figure 1 A flowchart of a battery risk warning method provided in some embodiments of the present application; Figure 2 Differential voltage curves provided for some embodiments of the present application; Figure 3 A current variation curve in the second mode charging provided by some embodiments of the present application; Figure 4 A calendar life decay curve of a battery to be tested provided in some embodiments of the present application; Figure 5 A warning value variation curve of a battery to be tested provided in some embodiments of the present application; Figure 6 A schematic diagram of a battery risk warning device according to some embodiments of the present application; Figure 7 A schematic diagram of a computing device for implementing a battery risk warning method provided in some embodiments of the present application. DETAILED DESCRIPTION

[0042] The following embodiments of the technical solution of the present application will be described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians 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" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0044] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0045] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0046] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the 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 associated objects before and after are in an "or" relationship.

[0047] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0048] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0049] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0050] At present, from the perspective of market development, the application of rechargeable batteries is becoming more and more extensive. Rechargeable batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in various electronic devices, such as electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of rechargeable batteries, the market demand is also constantly expanding.

[0051] The calendar life of a battery refers to the performance degradation of a battery when it is not in use, only due to the passage of time. During this period, it is not used or is only used in small amounts. This is a natural degradation process that is independent of the frequency of use and is mainly caused by chemical reactions inside the battery and material aging. It can be understood that the calendar life test can test whether the battery has a life risk. Risky batteries can be intercepted in time to avoid losses to users. Batteries that pass the test can be released for safe use by users.

[0052] In the related art, the calendar life test of the battery is to store the battery at a specific temperature for a period of time, then test the remaining capacity, and repeat the process until the test time meets the requirements (for example, one or two years). By analyzing the remaining capacity obtained by this method to judge the attenuation of the calendar life, it is possible to evaluate whether the battery has a calendar life risk.

[0053] However, since calendar life testing takes a long time, it usually takes at least one or two years to obtain effective evaluation results. In other words, it takes a long time to determine whether the battery has calendar life risks, resulting in a long battery testing and R&D cycle.

[0054] In response to the above problems, an embodiment of the present application provides a battery risk warning method, which can be used in the calendar life test of a battery, by charging a battery to be tested at a preset power level in a first mode, and obtaining first charging data of the battery to be tested in the first mode charging; charging the battery to be tested after being charged in the first mode in a second mode, and obtaining second charging data of the battery to be tested in the second mode charging; determining a current warning value of the battery to be tested based on the first charging data and the second charging data; and determining that the battery to be tested is in a risky state in response to the current warning value and the historical warning value of the battery to be tested satisfying preset warning conditions, so that it is possible to quickly determine whether the battery has a calendar life risk through the warning value, so that the battery with a calendar life risk can be intercepted in time to facilitate further improvement, thereby greatly shortening the calendar life test time and the battery testing and development cycle.

[0055] The battery risk warning method provided in the embodiment of the present application can be applied to the calendar life test of the battery to quickly expose the calendar life risk of the battery (i.e., to achieve pre-exposure of the storage cell life risk). It can be understood that the method provided in the embodiment of the present application is not limited to the calendar life test, and it can also be used in other scenarios of the battery that require risk warning, for example, it can be used in ORT (Ongoing Reliability Testing) detection of mass-produced batteries (such as including cycle life testing or storage calendar aging testing), or the method provided in this embodiment can also be used in the testing of batteries that have been put into use, for example, the battery of an electric vehicle can collect charging data through BMS (Battery Management System) or charging piles after the electric vehicle is used to implement the battery risk warning method provided in this embodiment.

[0056] The battery involved in the embodiments of the present application may be, but is not limited to, a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel metal hydride battery, a nickel cadmium battery, a lead storage battery, etc. In addition, the battery involved in the embodiments of the present application may be a battery in an electric vehicle, or a battery in other electrical equipment or energy storage equipment.

[0057] The energy storage device in the embodiment of the present application may include one or more battery clusters to increase the voltage and capacity of the energy storage device. The battery cluster may include multiple batteries, and the multiple batteries are connected in series through a busbar to increase the voltage of the energy storage device. When the energy storage device includes multiple battery clusters, the multiple battery clusters are connected in parallel to increase the capacity of the energy storage device.

[0058] The energy storage device can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems or temporary power supply systems, etc. The energy storage device can store electrical energy as needed and output electrical energy at an appropriate time. For example, the energy storage device can store electrical energy during low electricity consumption, and provide electrical energy to relevant users or electrical equipment during peak electricity consumption. The energy storage system provided in the embodiment of the present application can be any power system that requires the use of an energy storage device. As an example, the energy storage device is an energy storage container or an energy storage cabinet.

[0059] The electrical equipment in the embodiments of the present application may be, but is not limited to, mobile phones, tablets, laptop computers, electric toys, electric tools, battery cars, electric cars, ships, spacecraft, etc. Among them, the electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and the spacecraft may include airplanes, rockets, space shuttles, and spacecraft, etc.

[0060] It should be understood that the battery involved in the embodiments of the present application is not limited to the energy storage devices and electrical equipment described above, but can also be applied to all battery devices including a box and electrical equipment using the battery device.

[0061] For ease of explanation, the battery risk warning method provided by this embodiment is described below in conjunction with the scenario of calendar life test. The same is true for other test scenarios, which will not be described in detail.

[0062] Figure 1 This is a flowchart of a battery risk warning method provided in some embodiments of the present application. Figure 1 , an embodiment of the present application provides a battery risk warning method 100, comprising the following steps S110 to S140.

[0063] Step S110 , performing first mode charging on the battery to be tested at a preset power level, and obtaining first charging data of the battery to be tested in the first mode charging.

[0064] Step S120, performing second-mode charging on the battery to be tested after being charged in the first mode, and obtaining second charging data of the battery to be tested in the second-mode charging.

[0065] Step S130, determining a current warning value of the battery to be tested based on the first charging data and the second charging data.

[0066] Step S140 , in response to the current warning value and the historical warning value of the battery to be tested meeting a preset warning condition, determining that the battery to be tested is in a risky state.

[0067] Specifically, the preset power can be a specific power value or power range, for example, it can be 50%, 40%, 30%, 20% or 0 of the rated power of the battery, etc., and can be set according to actual conditions. The battery to be tested refers to the battery to be risk assessed. The battery category can refer to the above description and will not be repeated here.

[0068] The first mode charging refers to charging the battery in a specific charging mode, which can be a constant current (CC) charging mode, a constant voltage (Constant Voltage) charging mode, a fast charging mode, a trickle charging mode, a segmented charging mode, and other charging modes.

[0069] The first charging data refers to relevant data during the first mode charging process, such as data on changes in voltage, current, capacity, etc. over time and charging start and end times, and can be specifically collected according to the charging mode.

[0070] The second charging mode refers to charging the battery in another specific charging mode, which can also be a constant current (CC) charging mode, a constant voltage (CV) charging mode, a fast charging mode, a trickle charging mode, a segmented charging mode, etc. It can be understood that the charging modes of the first mode charging and the second mode charging can be different. For example, the first mode charging can be constant current charging, the second mode charging can be constant voltage charging, and so on.

[0071] The second charging data refers to relevant data during the second mode charging process, such as data on changes in voltage, current, capacity, etc. over time and charging start and end times, etc., and can be specifically collected according to the charging mode.

[0072] In this embodiment, in step S110, the battery to be tested at a preset power level may be charged in a first mode to obtain first charging data.

[0073] After step S110 , the battery to be tested may then be charged in a second mode to obtain second charging data.

[0074] After obtaining the first charging data in step S110 and the second charging data in step S120 , the first charging data and the second charging data may be processed, such as by differential processing, to obtain a current warning value.

[0075] It can be understood that in the calendar life test, multiple rounds of testing need to be performed in cycles, and each round of testing requires the battery to be stored at a specific temperature for a period of time, and then the remaining capacity of the battery is tested. The method 100 provided in this embodiment can be applied to each round of testing, that is, steps S110 to S140 can be performed after each round of storage, and the current warning value is the warning value measured in the current round. The historical warning value is each warning value determined before the current warning value, that is, each warning value obtained in each round before the current round.

[0076] In step S140, it is possible to determine whether the battery to be tested is currently in a risky state by judging whether the current warning value and the historical warning value satisfy a preset warning condition.

[0077] The preset warning condition may be a change pattern of the warning value, such as a continuous decrease in the warning value or a turning point in the warning value, which may be determined based on comparative tests. Being in a risky state means that the battery to be tested has a life risk and needs to be intercepted.

[0078] It can be understood that if the preset warning conditions are not met, it can be determined that the current battery is not in a risky state and the next round of testing can be performed. If the preset warning conditions are met, it is determined that the battery to be tested has a calendar life risk and the test is terminated at the same time, that is, the calendar life test can be terminated in advance without the need for the next round of testing.

[0079] In some embodiments, in order to obtain accurate test results, the above steps S110 to S120 can be performed once after the battery to be tested has been used for a period of time (short-term use + long-term static). In addition, the battery power can be reduced to below 50% (preset power) as much as possible before charging in step S110. It can be understood that in the actual test process, steps S110 to S140 provided in this embodiment can be interleaved into other test processes according to frequency / time. For example, in the cycle test, the above steps can be performed once after every 100~200cls, and in the storage test, the above steps can be performed once every 10~30 days of storage.

[0080] In this embodiment, the first charging data and the second charging data of the battery to be tested can be obtained through the first mode charging and the second mode charging, and then the current warning value can be determined, and according to the current warning value and the historical warning value, it can be determined whether the battery to be tested is currently in a risky state. Compared with the calendar testing method in the related art to discover risky batteries, the method provided in this embodiment can quickly determine whether the battery has a calendar life risk without going through the entire calendar testing cycle, that is, the test risk can be quickly obtained, and abnormal batteries with risks can be identified in advance, so that risky batteries can be intercepted in time for further improvement, which greatly shortens the calendar life test time, is conducive to improving the efficiency of battery testing and research and development, and saving testing resources.

[0081] According to some embodiments of the present application, the first mode charging of the battery to be tested at a preset power level in step S110 may include: based on a first charging rate, constant current charging of the battery to be tested at a preset power level until the voltage of the battery to be tested reaches a maximum voltage; wherein the first charging rate A1 satisfies: 0.1Cn A1 Cn is a preset capacity value or the remaining capacity of the battery to be tested measured in the previous warning value determination process.

[0082] In this embodiment, the first mode charging may refer to constant current charging (CC) at a first charging rate, and when the voltage of the battery to be tested reaches the maximum voltage Vmax, the constant current charging is stopped. Among them, constant current charging refers to keeping the charging current constant during the charging process. Among them, the maximum voltage refers to the maximum voltage during the battery charging process. Ensuring that the voltage during the charging process does not exceed the maximum voltage can prevent the battery from being overcharged, which is beneficial to the life and safety of the battery.

[0083] Among them, the remaining capacity refers to the amount of electricity that the battery can still release in the current state. The first charging rate A1 is a parameter used to describe the speed of battery charging, which can be expressed as the ratio of the battery's charging current to Cn. Among them, Cn can adopt a preset capacity value, that is, in multiple rounds, Cn adopts a fixed value. The preset capacity value can be, for example, the rated capacity of the battery to be tested or the residual capacity measured in the first round (the first warning value determination process) of the calendar life test. Of course, the value of Cn can also change according to different rounds of testing. For example, since the calendar life test needs to be carried out for multiple rounds, the Cn value can also be the residual capacity of the battery to be tested measured in the previous warning value determination process, that is, the residual capacity of the battery to be tested measured in the previous round (referred to as the previous residual capacity), and the residual capacity of the previous round is used as the value of Cn in each round.

[0084] In this embodiment, the first charging rate A1 can be 0.1Cn, 0.15Cn, 0.2Cn, 0.25Cn, 0.3Cn, 0.32Cn, 0.33Cn, etc.

[0085] In some embodiments, the first mode charging condition may be 0.33Cn CC Vmax, that is, constant current charging is performed with a current of 0.33 times the preset capacity value or the last remaining capacity, and constant current charging is stopped when the battery voltage reaches the set maximum voltage Vmax.

[0086] In this embodiment, by performing constant current charging on the battery to be tested at the first charging rate, the charging current can be kept at the maximum allowable value, the battery power can be quickly charged to a certain level, and efficient and fast charging can be achieved. At the same time, the control logic of constant current charging is simple, easy to implement, and low in cost. At the same time, by reasonably setting the first charging rate, it is possible to use a lower discharge current, reduce the pressure of the chemical reaction inside the battery, reduce the loss of electrode materials, and extend the life. At the same time, the internal polarization reaction of the battery is reduced, the charging efficiency is improved, and the safety of the battery can be effectively improved.

[0087] According to some embodiments of the present application, the second mode charging of the battery to be tested after being charged in the first mode in step S120 may include: performing constant voltage charging on the battery to be tested after being charged in the first mode until the current of the battery to be tested reaches the cut-off current; wherein the cut-off current B satisfies , Cn is the preset capacity value or the remaining capacity of the battery to be tested measured in the previous warning value determination process.

[0088] In this embodiment, after the first mode charging is performed, the second mode charging can be switched to, and the second mode charging can refer to constant voltage charging (CV), and when the current of the battery to be tested reaches the cut-off current, the constant voltage charging is stopped. Among them, constant voltage charging refers to keeping the charging voltage constant during the charging process.

[0089] The cut-off current B refers to the current threshold used to determine whether charging is completed during the battery charging process. The value of Cn can refer to the above embodiment and will not be described in detail.

[0090] In this embodiment, the cut-off current B can be 0.02Cn, 0.03Cn, 0.04Cn, 0.05Cn, etc.

[0091] In some embodiments, the second mode charging condition may be Vmax CV 0.04Cn, that is, when the voltage of the first mode charging reaches Vmax, it switches to constant voltage charging, and the charging current gradually decreases until 0.04Cn, at which time the second mode charging is terminated.

[0092] In this embodiment, constant voltage charging is adopted after constant current charging until charging is completed, so as to avoid overcharging, protect the battery and prolong the battery life. At the same time, by reasonably setting the cut-off current, the battery can be ensured to be fully charged, which helps to obtain the accuracy of the current remaining capacity of the battery in the fully charged state, and at the same time can improve safety and optimize charging efficiency.

[0093] According to some embodiments of the present application, determining the current warning value of the battery to be tested based on the first charging data and the second charging data in step S130 may include: determining the differential voltage curve of the battery to be tested based on the first charging data; determining the first peak moment based on the differential voltage curve, wherein the first peak moment is used to characterize the peak moment at which the negative electrode material of the battery to be tested undergoes a phase transition; determining the current warning value of the battery to be tested based on the first peak moment, the first charging data, and the second charging data.

[0094] In this embodiment, taking constant current charging as an example, the first charging data may include voltage variation data V of the battery to be tested over time and capacity variation data Q of the battery to be tested over time, and the differential voltage curve may be obtained by dV / dQ.

[0095] Figure 2 For differential voltage curves provided in some embodiments of the present application, please refer to Figure 2 , Figure 2 Based on the first charging rate, the battery to be tested with a preset power level is charged with a constant current until the voltage of the battery to be tested reaches a voltage differential curve at a maximum voltage stage.

[0096] The first peak moment T1 may be the peak moment when the negative electrode material of the battery to be tested undergoes a phase transition, for example, the moment corresponding to the phase transition peak of the negative electrode material graphite from the LiC12 phase to the LiC6 phase. For example, it may be determined by the moment corresponding to the peak of the differential voltage curve in a specific voltage range.

[0097] It can be understood that the specific voltage range may be related to the type of battery. For example, the peak value of a lithium iron phosphate battery appears at about 3.5V, and that of a ternary lithium battery appears at about 3.7V. The first peak moment T1 may be determined through the above specific range.

[0098] The current warning value may be obtained according to the first peak moment and the first charging data and the second charging data.

[0099] It can be understood that when the inventors of the present application differentiated according to the first charging data, they found that the differential capacitance curve (dQ / dV) represents the amount of charge that the material can charge and discharge under a unit voltage change. At high SOC (State of Charge), the potential of graphite remains near 0V, and even if lithium deposition occurs, the potential of graphite will not change much. However, the positive electrode material, especially the ternary nickel-cobalt-manganese material, will cause a significant change in voltage due to the collapse of the lithium-poor phase material. Therefore, the differential capacitance curve under high SOC reflects the change of the positive electrode material, rather than the change of lithium deposition at the negative electrode, so it cannot play an accurate early warning role. In this embodiment, the differential voltage curve can be determined according to the first charging data, and the current early warning value can be obtained according to the differential voltage curve, so that the change of lithium deposition at the negative electrode can be accurately reflected, and then an accurate early warning role can be played, which is beneficial to the effectiveness of risk status judgment.

[0100] According to some embodiments of the present application, determining the first peak moment based on the differential voltage curve includes: determining the occurrence time of the peak in the differential voltage curve within the first preset state of charge range as the first peak moment, wherein the first preset state of charge range SOC1 satisfies: 50% SOC1 .

[0101] The state of charge (SOC) is a parameter that describes the remaining power of the battery, usually expressed as a percentage. The first preset state of charge range SOC1 satisfies: 50% SOC1 It can be understood that there is usually only one peak in this range, and this peak corresponds to the moment when the phase transition peak of the negative electrode material graphite from the LiC12 phase to the LiC6 phase corresponds to.

[0102] Please refer to Figure 2 The voltage differential curve will also fluctuate and have a peak in the early stage. By limiting the first preset state of charge range, the peak moment when the negative electrode material in the differential voltage curve undergoes a phase transition can be accurately found, that is, the first peak moment T1 can be accurately obtained.

[0103] According to some embodiments of the present application, the above-mentioned steps of determining the current warning value of the battery to be tested based on the first peak moment, the first charging data and the second charging data may include: determining a first amount of electricity charged into the battery to be tested from the first peak moment to the first charging end moment of the first mode charging based on the first charging data; determining a second amount of electricity charged into the battery to be tested from the first charging end moment to the second charging end moment of the second mode charging based on the second charging data; and determining the ratio of the first amount of electricity to the second amount of electricity as the current warning value of the battery to be tested.

[0104] In this embodiment, the first charging data also includes a first charging end time T2, that is, the charging end time of the first mode charging, for example, the time when the voltage of the battery to be tested reaches the maximum voltage in the first mode charging, such as Figure 2 The first charging data may also include first change data of current over time. It can be understood that during constant current charging, the current is a constant value.

[0105] Figure 3 For the current variation curve in the second mode charging provided in some embodiments of the present application, please refer to Figure 3 , Figure 3 The battery to be tested is charged in the first mode with a constant voltage until the current of the battery to be tested reaches a current change curve with time in the cut-off current stage.

[0106] The starting time of the current change curve corresponds to the first charging end time T2 of the first mode charging, and the second charging data also includes the second charging end time, that is, the charging end time of the second mode charging, for example, the time when the battery to be tested reaches the cut-off current in the second mode charging, such as Figure 3 The moment T3.

[0107] The second charging data may also include second variation data of the current over time. It can be understood that during constant voltage charging, the current is variation data, such as Figure 3 shown.

[0108] After obtaining T1, T2, and T3, the current warning value can be obtained according to T1, T2, T3 and the current in the two modes of charging, and the first power charged into the battery under test during the time period from T1 to T2 , the second amount of electricity charged into the battery under test during the time period from T2 to T3 , get the current warning value.

[0109] Understandably, the first power The calculation method can be to calculate the amount of electricity charged in the first mode charging (constant current charging) stage from T1 to T2, ,in A charging current for first mode charging.

[0110] Second power The calculation method can be to calculate the amount of electricity charged in the second mode charging (constant voltage charging) stage from T2 to T3, ,in, The charging current for the second mode charging is a variable value.

[0111] Current warning value It can be calculated based on the first power and the second power. .

[0112] The current warning value can be obtained through this embodiment, and the current warning value can be used to accurately and effectively reflect the risk status of the battery to be tested.

[0113] According to some embodiments of the present application, in response to a current warning value and a historical warning value of the battery to be tested satisfying a preset warning condition, determining that the battery to be tested is in a risky state may include: determining a warning data set based on the current warning value and the historical warning value of the battery to be tested, wherein the warning data set includes each warning value of the battery to be tested determined in chronological order; in response to a continuous decrease in the warning value in the warning data set, and the decrease in the warning value becomes larger successively, determining that the battery to be tested is in a risky state.

[0114] In this embodiment, a warning data set can be obtained based on the current warning value and the historical warning values. It can be understood that the warning data set can be a data sequence, that is, each warning data is added to the warning data set in sequence according to the rounds of calendar life test. It can be understood that the current warning value is always the last warning value data in the warning data set.

[0115] Of course, the warning data set may also be expressed in the form of a curve, for example, a curve showing the relationship between the number of test days (which may be the number of battery storage days in a calendar life test) and the warning value.

[0116] It can be understood that by judging that each warning value in the warning data set decreases continuously and the decrease amplitude increases successively, it can be determined that the battery under test is in a risky state. It can be understood that the continuous decrease may refer to a decrease for 2 consecutive times, a decrease for 3 consecutive times, or a decrease for 4 consecutive times.

[0117] It is understandable that when problems such as lithium plating occur in the battery cell, since the lithium insertion process changes from only lithium plating into graphite to lithium plating into graphite and lithium metal deposition, an additional lithium plating process is added, which will cause the Q2 value to increase, the Q1 value to decrease, and the warning value to drop significantly. Therefore, the decrease in the warning value can be used to accurately determine whether the battery is in a risky state.

[0118] This embodiment can accurately determine that the battery is in a risky state by determining that the warning value continuously decreases and the decrease amplitude gradually increases, thereby improving the accuracy of the risk warning.

[0119] According to some embodiments of the present application, in response to a warning value continuously decreasing in a warning data set, and the magnitude of the decrease in the warning value becomes larger successively, determining that the battery to be tested is in a risky state may include: in response to a warning value decreasing for the first time in the warning data set, and the magnitude of the decrease in the warning value meets a first threshold, determining that the battery to be tested is in a first-level warning state; in response to a warning value decreasing twice in a row in the warning data set, and the magnitude of the decrease in the warning value becomes larger successively, determining that the battery to be tested is in a second-level warning state; in response to a warning value decreasing three times in a row in the warning data set, and the magnitude of the decrease in the warning value becomes larger successively, determining that the battery to be tested is in a third-level warning state, wherein the third-level warning state is used to characterize that the battery to be tested is in a risky state.

[0120] This embodiment may adopt a three-level warning mechanism, and when the third-level warning state is reached, it is determined that the battery is in a risk state. In the first-level risk state and the second-level risk state, only a prompt may be given without any processing.

[0121] It can be understood that the current warning value is expressed as , the previous warning value of the current warning value (i.e. the warning value determined in the previous round) is expressed as , and so on, the early warning data set can be expressed as [ ], where i is the cumulative number of rounds of the current calendar life test.

[0122] When the warning value in the warning data set drops for the first time, that is, when the warning value drops for the first time , and the difference between the two ( ) exceeds the first threshold, it can be considered that the battery to be tested is in a first-level warning state. The first threshold can be determined according to actual experimental tests, and can be zero or other numbers.

[0123] When the warning value in the warning data set decreases twice in a row, and the decrease in the warning value becomes larger, it can be understood that ,and When this state occurs, it can be determined that the battery under test is currently in the second-level warning state.

[0124] When the warning value of the warning data set decreases three times in a row, and the decrease in the warning value increases successively, it can be understood that ,and When this state occurs, it can be determined that the battery to be tested is currently in the third-level warning state, that is, in a risk state.

[0125] Figure 4The calendar life decay curve of the battery to be tested provided in some embodiments of the present application is Figure 5 This is a curve of the change of the warning value of the battery to be tested provided in some embodiments of the present application. Please refer to Figure 4 and Figure 5 In order to obtain an accurate early warning mechanism, this embodiment uses two groups of cells as a control group, and two parallel sample cells are used in each group. The cells in the first group (black curve in the figure) can be normal cells, and for comparison, the second group (grey curve in the figure) can be abnormal cells (i.e., cells that are expected to have calendar life risks) made by replacing electrode materials.

[0126] In order to accurately verify the method provided in this embodiment, the calendar life test method is used to perform calendar life tests on two groups of battery cells, that is, the battery is stored at a specific temperature for a period of time, and then the remaining capacity is tested, and the above storage and remaining capacity tests are repeated until the battery capacity decays to a preset state, thereby obtaining Figure 4 The calendar life decay curve is the relationship between the capacity retention rate of the battery cell and the number of storage days. Figure 4 It can be seen that the remaining capacity of the second group of batteries decreased significantly after being stored for about 100 days.

[0127] At the same time, the method 100 can be used to calculate the warning value after each storage to obtain a warning value data set, and the warning value data set is used Figure 5 The relationship curve between the warning value and the storage days is shown.

[0128] and Figure 5 Through the warning value, it was found that in the second round of testing of the second group of battery cells, the warning value had shown a slight decline. In the third round of testing, it showed obvious lithium plating signals (that is, the curve showed a significant decline). At the same time, the first group of battery cells also showed lithium plating signals at around 120 days.

[0129] Based on the above experimental analysis and principle analysis, a three-level early warning mechanism can be obtained, namely: Level 1 warning status: The warning value drops for the first time.

[0130] Level 2 warning status: The warning value decreases twice in a row, and the decrease becomes larger.

[0131] Level 3 warning status: The warning value decreases three times in a row, and the decline gradually increases.

[0132] In addition, it is understandable that Figure 5 In the three-level early warning mechanism, for the second group of cells, when obvious lithium plating signals appear (i.e., risk state), it takes about 45 days to confirm that the cell is at risk. Figure 4In the present invention, it takes at least 100 days to judge whether there is a risk by the capacity retention rate. Therefore, the present method 100 can quickly determine whether the battery has a calendar life risk.

[0133] In this embodiment, a three-level warning mechanism can be used to implement a step-by-step warning, quickly and accurately determine whether the battery is in a risky state, and improve the accuracy of risk warning.

[0134] According to some embodiments of the present application, the method 100 may further include: performing a first mode discharge on the battery to be tested until the power of the battery to be tested reaches a preset power; wherein the preset power E satisfies, 0.5E0, E0 is the rated capacity of the battery to be tested.

[0135] Specifically, before step S110, the battery to be tested may be discharged in a first mode to reduce the power of the battery to be tested, so as to facilitate subsequent charging and improve the validity of the obtained charging data. The first mode discharge may be constant current discharge, constant voltage discharge, constant power discharge, pulse discharge or constant resistance discharge.

[0136] It can be understood that the stopping condition of the first mode discharge is that the power of the battery to be tested reaches the preset power E. In this embodiment, 0.5E0, E0 is the rated capacity of the battery to be tested, E can be 0, that is, the battery to be tested is at the lower limit of the capacity corresponding to 0%. Of course, E can also be 0.1E0, 0.2E0, 0.3E0, 0.4E0, 0.5E0, etc.

[0137] It can be understood that, for lithium iron phosphate batteries, the first mode discharge can discharge the voltage to below 3.3V, and the ternary lithium battery can discharge the voltage to below 3.6V, so that the power of the battery to be tested reaches the preset power.

[0138] In this embodiment, the power of the battery to be tested can be reduced by discharging in the first mode, thereby increasing the amount of subsequent first charging data and second charging data, so as to accurately analyze the risk status of the battery.

[0139] According to some embodiments of the present application, performing a first mode discharge on the battery to be tested may include: performing a constant current discharge on the battery to be tested based on a first discharge rate; wherein the first discharge rate D1 satisfies: D1 , Cn is the preset capacity value or the remaining capacity of the battery to be tested measured in the previous warning value determination process.

[0140] In this embodiment, the first mode discharge may refer to constant current discharge (DC) at a first discharge rate, and when the power of the battery to be tested reaches a preset power, the constant current discharge is stopped. The constant current discharge refers to the battery releasing electrical energy in the form of a constant current.

[0141] The first discharge rate D1 is a parameter used to describe the speed of battery discharge, which can be expressed as the ratio of the battery discharge current to Cn. D1 For example, the first discharge rate D1 can be 0.1Cn, 0.2Cn, 0.3Cn, 0.33Cn, 0.4Cn, 0.5Cn, 0.6Cn, 0.7Cn, 0.8Cn, 0.9Cn, 1.0Cn, etc. The value of Cn can refer to the above embodiment and will not be repeated here.

[0142] In some embodiments, the first mode discharge condition can be 0.33Cn DC Vmin, that is, constant current discharge is performed with a current of 0.33 times the preset capacity value or the previous remaining capacity until the voltage drops to Vmin. Vmin here can refer to the minimum voltage Vmin of the battery to be tested. It can be understood that when discharged to the minimum voltage, the corresponding power is 0.

[0143] In this embodiment, constant current discharge has the advantages of stable current, reliable data, and simple control. At the same time, by reasonably setting the first discharge rate, the battery life can be extended, the discharge capacity can be increased, the influence of internal resistance can be reduced, and the safety can be improved.

[0144] According to some embodiments of the present application, method 100 may further include the following steps: in response to the current warning value and the historical warning value of the battery to be tested not satisfying the preset warning condition, determining the current remaining capacity of the battery to be tested; in response to the current remaining capacity not decaying to a preset state or the total test time of the battery to be tested not reaching a preset time, storing the battery to be tested at high temperature; and executing the process of determining the next warning value of the battery to be tested.

[0145] It can be understood that when method 100 is used for calendar life testing, when it is determined that the current warning value and the historical warning value of the battery to be tested do not meet the preset warning condition, if the battery to be tested does not reach the third-level warning state, the battery to be tested can be subjected to a remaining capacity test to obtain the current remaining capacity of the battery to be tested. The current remaining capacity is the amount of electricity that can be released by the battery in the current state.

[0146] The preset state may be a battery health state (SOH) representation, for example, it may be 60% SOH, of course, it may also be 70% SOH or 80% SOH, which may be set according to actual conditions. The preset number of days may be the total number of days planned for the calendar life test, for example, the preset number of days may be 500 days, etc.

[0147] It is understood that the storage of the calendar life test can be carried out in a high temperature environment to accelerate calendar aging. When the current remaining capacity has not decayed to the preset state or the total test days of the battery to be tested have not reached the preset number of days, the high temperature storage can continue for a certain number of days (for example, 15 days). The temperature of the high temperature storage can be in the range of 45 degrees to 70 degrees.

[0148] After high-temperature storage, the process of determining the next warning value of the battery to be tested can be executed, that is, returning to execute steps S110 to S140 to perform the next round of testing, so as to determine the next warning value of the current warning value, that is, the next warning value.

[0149] In addition, the method 100 may include: in response to the current remaining capacity decaying to a preset state or the total test duration of the battery under test reaching a preset duration, ending the calendar life test of the battery under test. It is understood that In the related art, when the battery to be tested is subjected to a calendar life test, the test termination condition is that the current remaining capacity decays to a preset state or the total test duration of the battery to be tested reaches a preset duration. After the test is completed, all test data are analyzed to determine whether the battery is risky. In the present embodiment, the calendar life test can be terminated in advance for the battery to be tested that is in a risky state, without waiting until the test termination condition is reached. The battery in a risky state can be discovered in time, thereby shortening the test time.

[0150] In this embodiment, when no risk state occurs, the calendar life test can continue to be performed, and calendar aging can be performed on batteries that do not present a risk to obtain the calendar life of the battery.

[0151] According to some embodiments of the present application, determining the current remaining capacity of the battery to be tested in the above steps includes: performing a second mode discharge on the battery to be tested until the voltage of the battery to be tested reaches a minimum voltage, and obtaining first discharge data of the battery to be tested in the second mode discharge; based on the first discharge data, determining the current remaining capacity of the battery to be tested.

[0152] It can be understood that the battery to be tested can be fully charged in the second mode of charging, and the voltage of the battery to be tested can be discharged to the minimum voltage Vmin through the second mode of discharging. The minimum voltage refers to the minimum voltage during the discharge process of the battery, and ensuring that the voltage during the discharge process will not be lower than the minimum voltage can prevent the battery from being over-discharged, which is beneficial to the life and safety of the battery.

[0153] The second mode discharge may be the same as the first mode discharge or may be different. The second mode discharge may be constant current discharge, constant voltage discharge, constant power discharge, pulse discharge or constant resistance discharge, etc. It is understood that the stopping condition of the second mode discharge is that the power of the battery to be tested reaches the minimum voltage.

[0154] At the same time, the first discharge data during the second mode discharge process can be recorded, and the first discharge data can be the discharge time and discharge current of the second mode discharge, so that the current remaining capacity of the battery to be tested can be calculated according to the first discharge data. It can be understood that the current remaining capacity can be used as Cn for the next round.

[0155] By discharging the battery to be tested to the minimum voltage through the first mode discharge, the current remaining capacity of the battery to be tested can be accurately obtained, and overcharging can be prevented, which is beneficial to the life and safety of the battery.

[0156] According to some embodiments of the present application, the second mode discharge of the battery to be tested in the above step includes: performing constant current discharge on the battery to be tested based on a second discharge rate; wherein the second discharge rate D2 satisfies: 0 D2 , Cn is the preset capacity value or the remaining capacity of the battery to be tested measured in the previous warning value determination process.

[0157] In this embodiment, the second mode discharge may refer to constant current discharge at a second discharge rate, and the constant current discharge is stopped when the voltage of the battery to be tested reaches a minimum voltage.

[0158] The second discharge rate D2 is a parameter used to describe the speed of battery discharge, which can be expressed as the ratio of the battery discharge current to Cn. D2 For example, the first discharge rate D2 can be 0.1Cn, 0.2Cn, 0.3Cn, 0.33Cn, 0.4Cn, 0.5Cn, 0.6Cn, 0.7Cn, 0.8Cn, 0.9Cn, 1.0Cn, etc. The value of Cn can refer to the above embodiment and will not be repeated here.

[0159] In some embodiments, the second mode discharge condition may be 0.33Cn DC Vmin, ie, constant current discharge is performed at a current of 0.33 times of the preset capacity value or the last remaining capacity until the voltage drops to Vmin, where Vmin may refer to the minimum voltage Vmin of the battery to be tested.

[0160] Constant current discharge has the advantages of stable current, reliable data and simple control. It can accurately measure the remaining capacity of the battery. At the same time, by reasonably setting the second discharge rate, it can extend the battery life, increase the discharge capacity, reduce the influence of internal resistance and improve safety.

[0161] According to some embodiments of the present application, after performing the second mode discharge on the battery to be tested in the above steps until the power of the battery to be tested reaches the minimum voltage, method 100 may further include: performing the third mode charging on the battery to be tested until the battery to be tested reaches a second preset state of charge.

[0162] The second preset state of charge SOC2 satisfies: 90% SOC2 .

[0163] The third mode charging refers to charging the battery in a specific charging mode, which can be a constant current charging mode, a constant voltage charging mode, a fast charging mode, a trickle charging mode, a segmented charging mode, and other charging modes. The charging cut-off condition of the third mode charging can be that the voltage of the battery to be tested reaches the second preset state of charge SOC2. In this embodiment, 90% SOC2 , for example, it may be 90%, 92%, 94%, 96%, 98%, 100%, etc. It can be understood that the third charging mode may be the same as the first charging mode, but may also be different.

[0164] By discharging in the second mode, after measuring the current remaining capacity, and before storage, the battery to be tested can be charged so that it is fully charged or nearly fully charged, and the battery SOC can be adjusted for aging testing, that is, for the next round of testing.

[0165] According to some embodiments of the present application, the third mode charging of the battery to be tested in the above steps includes: performing constant current charging of the battery to be tested based on the second charging rate; wherein the second charging rate A2 satisfies: 0 A2 Cn is a preset capacity value or the remaining capacity of the battery to be tested measured in the previous warning value determination process.

[0166] In this embodiment, the third mode charging may refer to constant current charging (CC) at a second charging rate, and when the voltage of the battery to be tested reaches a second preset state of charge, the constant current charging is stopped.

[0167] The second charging rate A2 is a parameter used to describe the charging speed of the battery, which can be expressed as the ratio of the charging current of the battery to Cn. The value of Cn can refer to the above embodiment and will not be described in detail.

[0168] In this embodiment, the second charging rate A2 can be 0.1Cn, 0.2Cn, 0.3Cn, 0.33Cn, etc.

[0169] In some embodiments, the third mode charging condition may be 0.33Cn CC Vmax, that is, constant current charging is performed at a current of 0.33 times the preset capacity value or the previous remaining capacity, and when the battery voltage reaches the set maximum voltage Vmax, constant current charging is stopped. It can be understood that when the battery voltage reaches Vmax, the battery is close to being fully charged, and the battery SOC meets the second preset state of charge.

[0170] In this embodiment, by performing constant current charging on the battery to be tested at the second charging rate, the charging current can be kept at the maximum allowable value, and the battery can be quickly charged to full charge, thereby achieving efficient and fast charging. At the same time, the control logic of constant current charging is simple, easy to implement, low cost, and safe and reliable.

[0171] In addition, it can be understood that the voltage of the battery can be stabilized by standing for a period of time, such as 5 minutes, before or between each charging and discharging step, which is beneficial to the accuracy of the measured data. For example, standing can be adopted before the first mode discharge, between the first mode discharge and the first mode charge, between the first mode charge and the second mode charge, between the second mode charge and the second mode discharge, and between the second mode discharge and the third mode charge to achieve the effect of stabilizing the voltage.

[0172] Figure 6 For a schematic diagram of a battery risk warning device in some embodiments of the present application, please refer to Figure 6 , the embodiment of the present application provides a battery risk warning device 600, including the following modules: The first acquisition module 610 is used to perform first mode charging on the battery to be tested at a preset power level, and to acquire first charging data of the battery to be tested in the first mode charging.

[0173] The second acquisition module 620 is used to perform second-mode charging on the battery to be tested after being charged in the first mode, and to obtain second charging data of the battery to be tested in the second-mode charging.

[0174] The first determining module 630 is configured to determine a current warning value of the battery to be tested based on the first charging data and the second charging data.

[0175] The second determination module 640 is configured to determine that the battery to be tested is in a risky state in response to the current warning value and the historical warning value of the battery to be tested satisfying a preset warning condition.

[0176] The first acquisition module 610, the second acquisition module 620, the first determination module 630 and the second determination module 640 may correspond to S110 to S140 in the battery risk warning method, respectively, and for the sake of brevity, they are not described here. It should be understood that corresponding to the embodiment of the battery risk warning method, the battery risk warning device 600 may also include more modules.

[0177] It should be noted that the functions of the various modules discussed herein can be divided into multiple modules, and / or at least some functions of multiple modules can be combined into a single module. The specific module discussed herein performing an action includes the specific module itself performing the action, or alternatively the specific module calling or otherwise accessing another component or module that performs the action (or performs the action in conjunction with the specific module). Therefore, the specific module that performs an action can include the specific module itself that performs the action and / or another module that the specific module calls or otherwise accesses and performs the action.

[0178] It should also be understood that various techniques may be described herein in the general context of software hardware elements or program modules. Figure 6 The various modules described can be implemented in hardware or in hardware in combination with software and / or firmware. For example, these modules can be implemented as computer program code / instructions, which are configured to be executed in one or more processors and stored in a computer-readable storage medium. Alternatively, these modules can be implemented as hardware logic / circuits. The hardware logic / circuit may include an integrated circuit chip (which includes a processor (e.g., a central processing unit (CPU), a microcontroller, a microprocessor, a digital signal processor (DSP), etc.), a memory, one or more communication interfaces, and / or one or more components in other circuits), and may optionally execute the received program code and / or include embedded firmware to perform functions.

[0179] Figure 7 A schematic diagram of a computing device for implementing a battery risk warning method provided in some embodiments of the present application. Figure 7 As shown, an embodiment of the present application also provides a computing device 700, including: at least one processor 705; and at least one memory 707 communicatively connected to the at least one processor 705, the at least one memory 707 storing instructions, and when the instructions are executed individually or collectively by the at least one processor 705, the computing device executes the method of any one of the above embodiments.

[0180] The computing device 700 may include at least one processor 705, memory 707, (multiple) communication interfaces 702, a display device 701, other input / output (I / O) devices 703, and one or more mass storage devices 706, which can communicate with each other, such as through a bus 704 or other appropriate connections. The memory 707 stores instructions, which, when executed by the processor 705, cause the processor 705 to perform the battery risk warning method in the above-mentioned embodiment.

[0181] The processor 705 may be a single processing unit or multiple processing units, all of which may include a single or multiple computing units or multiple cores. The processor 705 may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, state machines, logic circuits, and / or any computing device that manipulates signals based on operating instructions. Among other capabilities, the processor 705 may be configured to obtain and execute computer-readable instructions stored in the memory 707, mass storage device 706, or other computer-readable media, such as program codes of an operating system 708, program codes of an application program 709, program codes of other programs 710, and the like.

[0182] The memory 707 and the mass storage device 706 are examples of computer-readable storage media for storing instructions that are executed by the processor 705 to implement the various functions described above. For example, the memory 707 may generally include both volatile memory and non-volatile memory (e.g., RAM, ROM, etc.). In addition, the mass storage device 706 may generally include a hard drive, a solid-state drive, a removable medium, including external and removable drives, a memory card, a flash memory, a floppy disk, an optical disk (e.g., a CD, a DVD), a storage array, a network attached storage, a storage area network, etc. The memory 707 and the mass storage device 706 may all be collectively referred to herein as memory or computer-readable storage media, and may be a non-transitory medium capable of storing computer-readable, processor-executable program instructions as computer program code, which may be executed by the processor 705 as a specific machine configured to implement the operations and functions described in the examples herein.

[0183] A plurality of programs may be stored on the mass storage device 706. These programs include an operating system 708, one or more application programs 709, other programs 710, and program data 711, and they may be loaded into the memory 707 for execution. Examples of such application programs or program modules may include, for example, computer program logic (e.g., computer program code or instructions) for implementing the following components / functions: the battery risk warning device 600 (including the first acquisition module 610, the second acquisition module 620, the first determination module 630, and the second determination module 640), the battery risk warning method 100 (including any suitable steps of the battery risk warning method 100), and / or other embodiments described herein.

[0184] Although in Figure 7 700 , but operating system 708 , application programs 709 , other programs 710 , and program data 711 , or portions thereof, may be implemented using any form of computer-readable media accessible by computing device 700 .

[0185] One or more communication interfaces 702 are used to exchange data with other computing devices, such as through a network, direct connection, etc. Such communication interfaces can be one or more of the following: any type of network interface (e.g., a network interface card (NIC)), a wired or wireless (such as IEEE 802.11 wireless LAN (WLAN)) wireless interface, a Worldwide Interoperability for Microwave Access (Wi-MAX) interface, an Ethernet interface, a Universal Serial Bus (USB) interface, a cellular network interface, a Bluetooth TM interface, a Near Field Communication (NFC) interface, etc. The communication interface 702 can facilitate communication within a variety of network and protocol types, including wired networks (e.g., LAN, cable, etc.) and wireless networks (e.g., WLAN, cellular, satellite, etc.), the Internet, etc. The communication interface 702 can also provide communication with an external storage device (not shown) such as a storage array, a network attached storage, a storage area network, etc.

[0186] In some examples, a display device 701 such as a monitor may be included for displaying information and images to a user. Other I / O devices 703 may be devices that receive various inputs from a user and provide various outputs to the user, and may include a touch input device, a gesture input device, a camera, a keyboard, a remote control, a mouse, a printer, an audio input / output device, and the like.

[0187] The technology described herein can be supported by these various configurations of the computing device 700, including but not limited to specific examples of the technology described herein. For example, the functionality can also be implemented in whole or in part on the "cloud" by using a distributed system. The cloud includes and / or represents a platform for resources. The platform abstracts the underlying functionality of the hardware (e.g., server) and software resources of the cloud. Resources may include applications and / or data that can be used when performing computing processing on a server away from the computing device 700. Resources may also include services provided over the Internet and / or through a subscriber network such as a cellular or Wi-Fi network. The platform can abstract resources and functions to connect the computing device 700 to other computer devices. Therefore, the implementation of the functions described herein can be distributed throughout the cloud. For example, the functions can be implemented partially on the computing device 700 and partially through a platform that abstracts the functions of the cloud.

[0188] An embodiment of the present application also provides a computer-readable storage medium having instructions stored thereon. When the instructions are executed individually or collectively by one or more processors of a computing device, the computing device executes a method as described in any of the above embodiments.

[0189] Computer-readable storage media include volatile and nonvolatile, removable and non-removable media implemented by any method or technology for storage of information, such as computer-readable instructions, data structures, program modules, or other data. Computer-readable storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD), or other optical storage devices, magnetic cassettes, magnetic tapes, magnetic disk storage devices or other magnetic storage devices, or any other non-transmission media that can be used to store information for access by a computer device.

[0190] An embodiment of the present application provides a computer program product, including instructions, which, when executed individually or collectively by one or more processors of a computing device, cause the computing device to execute the method in any of the above embodiments.

[0191] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below.

[0192] The embodiment of the present application provides a battery risk warning method 100, which can be used in various battery tests, wherein the battery to be tested can be divided into square shell battery, cylindrical battery, laminated battery, soft pack battery, etc. according to the battery type, and the battery to be tested can be lithium iron phosphate battery, ternary battery, solid-state battery, etc. according to the battery material system.

[0193] Considering that the cycle test can be performed hundreds of times in about 10 days, the risk of cycle life can be quickly obtained, but the storage test (calendar life test) must be stored for more than 100 days to obtain results. Therefore, the following method is introduced to address the problem of too long storage calendar aging (calendar life) evaluation cycle, taking storage testing as an example. The risk warning method may include the following steps: 1. Take the battery to be tested and adjust it to the specified power level, generally close to the fully charged state, for example, 1C CC Vmax (high SOC can accelerate calendar aging).

[0194] 2. Store at high temperature for a certain period of time, generally 15 days (high temperature can accelerate calendar aging).

[0195] 3. Perform standard test steps to obtain the discharge capacity value and the first-level risk warning value.

[0196] The standard test steps may include: 1) Let stand for 5 minutes.

[0197] 2) 0.33Cn DC Vmin (first mode discharge), that is, constant current discharge with 0.33 times Cn until the voltage drops to Vmin. It can be understood that the discharge can be put below 50% of the power, and the known cut-off lower limit is used for cut-off, that is, Vmin corresponds to 0% of the power.

[0198] 3) Let stand for 5 minutes.

[0199] 4) 0.33Cn CC Vmax (first mode charging), constant current charging is performed with 0.33 times Cn. When the battery voltage reaches the set maximum voltage Vmax, constant current charging is stopped. Vmax here is the known voltage upper limit. The Vmax of the LFP (lithium iron phosphate) system is 3.65~3.8V, and the Vmax of the ternary system is 4.2~4.4V.

[0200] 5) Vmax CV 0.04Cn (second mode charging), constant voltage charging, the charging current gradually decreases until the cut-off current reaches 0.04Cn.

[0201] 6) Let stand for 5 minutes.

[0202] 7) 0.33Cn DC Vmin (second mode discharge), constant current discharge with 0.33 times Cn until the voltage drops to Vmin. The purpose is to obtain the current remaining capacity of the battery under test after reaching the full charge state.

[0203] 8) Let stand for 5 minutes.

[0204] 9) 0.33Cn CC Vmax (third mode charging), constant current charging is performed with 0.33 times Cn. When the battery voltage reaches the set maximum voltage Vmax, constant current charging is stopped. The purpose is to adjust the SOC of the battery to be tested for aging. Generally, a state close to full charge (90%~100% SOC) is selected.

[0205] 4. Store at high temperature for 15 days, repeating steps 1) to 9) in the standard test until the capacity decays to the preset state (e.g. 60% SOH) or the total test time is reached (e.g. 200 days or 500 days, etc.).

[0206] It can be understood that in some embodiments, in the first round of testing before storage, the Cn value can take the rated capacity value (for example, if the rated capacity of the battery cell is 100Ah, then the Cn value is calculated as 100Ah), and then the current remaining capacity (for example, 99Ah) is obtained in step 7), and the Cn value of the second round of testing can be calculated using the current remaining capacity (according to 99Ah), and each subsequent Cn value is iterated according to the test value of the previous round of step 7).

[0207] In other embodiments, Cn may use a fixed value (preset capacity value), for example, directly use the rated capacity value, or the remaining capacity obtained in the first round of testing, etc.

[0208] In addition, it can be understood that steps 1) to 5) can be used in various types of tests, such as cycle test or storage test, and steps 6) to 9) are described by taking the storage test as an example.

[0209] During the above test steps, the data of the voltage and capacity changes with the charging time in step 4) can be recorded, and the differential voltage curve dV / dQ can be calculated.

[0210] Combination Figure 2 and Figure 3 When the battery to be tested is charged, approximately in the 50%~65% SOC range (the first preset state of charge range), a phase transition peak of graphite from LiC12 phase to LiC6 phase will appear, and the time point corresponding to the peak is taken as the first time (first peak moment) T1.

[0211] The time point corresponding to the end of CC charging in step 4) is taken as the second time (first charging end time) T2.

[0212] The time point at which the CV constant voltage charging in step 5) ends is recorded as the third time (second charging end time) T3.

[0213] Calculate the first amount of electricity: the first amount of electricity charged by constant current from T1 to T2 ,in A charging current for first mode charging.

[0214] Calculate the second amount of electricity: the second amount of electricity charged from the constant voltage stage from T2 to T3 ,in The charging current for the second mode charging.

[0215] Warning value of calendar life calculate: .

[0216] It is understandable that when the battery cell has problems such as lithium deposition, the lithium deposition process changes from only lithium deposition into graphite to lithium deposition into graphite and lithium metal deposition, which will cause the Q2 value to increase, the Q1 value to decrease, and the warning value to increase. There was a significant decline.

[0217] Combination Figure 4 and Figure 5 In this embodiment, two groups of cells are used as control groups, and two parallel sample cells are used in each group. The cells in the first group (black curve in the figure) can be normal cells. For comparison, the cells in the second group (grey curve in the figure) can be abnormal cells (i.e., cells that are expected to have calendar life risks) made by replacing electrode materials.

[0218] In order to accurately verify the method provided in this embodiment, the calendar life test method is used to perform calendar life tests on two groups of battery cells, that is, the battery is stored at a specific temperature for a period of time, and then the remaining capacity is tested, and the above storage and remaining capacity tests are repeated until the battery capacity decays to a preset state, thereby obtaining Figure 4 The calendar life decay curve is the relationship between the capacity retention rate of the battery cell and the number of storage days. Figure 4 It can be seen that the remaining capacity of the second group of batteries decreased significantly after being stored for about 100 days.

[0219] and Figure 5 Through the warning value, it was found that in the second round of testing of the second group of battery cells, the warning value had shown a slight decline. In the third round of testing, it showed obvious lithium plating signals (that is, the curve showed a significant decline). At the same time, the first group of battery cells also showed lithium plating signals at around 120 days.

[0220] Based on the above principles and measured results, the following early warning rules can be derived: Level 1 warning status: The warning value drops for the first time.

[0221] Level 2 warning status: The warning value decreases twice in a row, and the decrease becomes larger.

[0222] Level 3 warning status: The warning value decreases three times in a row, and the decline gradually increases.

[0223] In addition, it is understandable that Figure 5 In the three-level early warning mechanism, for the second group of cells, when obvious lithium plating signals appear (i.e., risk state), it takes about 45 days to confirm that the cell is at risk. Figure 4 It takes at least 100 days to determine whether there is a risk by using the capacity retention rate. It can be seen that the method 100 can provide an early warning method for quickly determining whether a battery has a calendar life risk. The required test cycle only takes about one month. Batteries that pass the evaluation can be released to the client, and batteries with risks can be intercepted in time for further improvement, thereby shortening the calendar life test time.

[0224] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery risk warning method, characterized in that: include: Performing first mode charging on a battery to be tested at a preset power level, and acquiring first charging data of the battery to be tested in the first mode charging; Performing second-mode charging on the battery to be tested after being charged in the first mode, and acquiring second charging data of the battery to be tested in the second-mode charging; Determining a current warning value of the battery to be tested based on the first charging data and the second charging data; In response to the current warning value and the historical warning value of the battery to be tested satisfying a preset warning condition, it is determined that the battery to be tested is in a risky state.

2. The method according to claim 1, characterized in that The method of charging the battery to be tested at a preset power level in a first mode includes: Based on the first charging rate, constant current charging is performed on the battery to be tested at a preset power level until the voltage of the battery to be tested reaches a maximum voltage; Among them, the first charging rate A1 satisfies: 0.1Cn A1 Cn is a preset capacity value or the remaining capacity of the battery to be tested measured in the previous warning value determination process.

3. The method according to claim 1, characterized in that The step of charging the battery to be tested in the second mode after being charged in the first mode includes: Performing constant voltage charging on the battery to be tested after being charged in the first mode until the current of the battery to be tested reaches a cut-off current; Wherein, the cut-off current B satisfies , Cn is a preset capacity value or the remaining capacity of the battery to be tested measured in the previous warning value determination process.

4. The method according to claim 1, characterized in that: The determining, based on the first charging data and the second charging data, a current warning value of the battery to be tested includes: Determining a differential voltage curve of the battery to be tested based on the first charging data; Based on the differential voltage curve, determining a first peak moment, wherein the first peak moment is used to characterize the peak moment when the negative electrode material of the battery to be tested undergoes a phase transition; Based on the first peak moment, the first charging data, and the second charging data, a current warning value of the battery to be tested is determined.

5. The method according to claim 4, characterized in that The determining of the first peak moment based on the differential voltage curve comprises: The occurrence time of the peak value in the first preset state of charge range in the differential voltage curve is determined as the first peak time, wherein the first preset state of charge range SOC1 satisfies: 50% SOC1 .

6. The method according to claim 5, characterized in that The determining the current warning value of the battery to be tested based on the first peak moment, the first charging data, and the second charging data includes: Based on the first charging data, determining a first amount of electricity charged into the battery under test from the first peak moment to a first charging end moment of the first mode charging; Based on the second charging data, determining a second amount of electricity charged into the battery under test from the first charging end time to a second charging end time of the second mode charging; The ratio of the first electric quantity to the second electric quantity is determined as the current warning value of the battery to be tested.

7. The method according to claim 1, characterized in that In response to the current warning value and the historical warning value of the battery to be tested meeting a preset warning condition, determining that the battery to be tested is in a risky state includes: Determine a warning data set based on the current warning value and the historical warning values ​​of the battery to be tested, wherein the warning data set includes each warning value of the battery to be tested determined in chronological order; In response to the warning values ​​of the warning data set continuously decreasing, and the decreasing amplitudes of the warning values ​​becoming larger successively, it is determined that the battery to be tested is in a risky state.

8. The method according to claim 7, characterized in that In response to the warning value of the warning data set continuously decreasing, and the decreasing amplitude of the warning value gradually increases, determining that the battery to be tested is in a risky state includes: In response to the warning value of the warning data set decreasing for the first time, and the decreasing amplitude of the warning value meets a first threshold, determining that the battery to be tested is in a first-level warning state; In response to the warning value of the warning data set decreasing twice in succession, and the decreasing amplitude of the warning value gradually increases, determining that the battery to be tested is in a level 2 warning state; In response to the warning value of the warning data set decreasing three times in a row, and the decreasing amplitude of the warning value becomes larger successively, it is determined that the battery to be tested is in a third-level warning state, wherein the third-level warning state is used to indicate that the battery to be tested is in a risky state.

9. The method according to any one of claims 1 to 8, characterized in that The method further comprises: Discharging the battery under test in a first mode until the power level of the battery under test reaches the preset power level; The preset power E satisfies: 0.5E0, where E0 is the rated capacity of the battery to be tested.

10. The method according to claim 9, characterized in that The step of discharging the battery to be tested in a first mode includes: Based on a first discharge rate, performing constant current discharge on the battery to be tested; Among them, the first discharge rate D1 satisfies: D1 , Cn is a preset capacity value or the remaining capacity of the battery to be tested measured in the previous warning value determination process.

11. The method according to any one of claims 1 to 8, characterized in that The method further comprises: In response to the current warning value and the historical warning value of the battery to be tested not satisfying the preset warning condition, determining the current remaining capacity of the battery to be tested; In response to the current remaining capacity not decaying to a preset state or the total test duration of the battery to be tested not reaching a preset duration, performing high temperature storage on the battery to be tested; A process of determining the next warning value of the battery to be tested is executed.

12. The method according to claim 11, characterized in that The determining the current remaining capacity of the battery to be tested includes: Performing a second mode discharge on the battery to be tested until the voltage of the battery to be tested reaches a minimum voltage, and obtaining first discharge data of the battery to be tested in the second mode discharge; Based on the first discharge data, a current remaining capacity of the battery to be tested is determined.

13. The method according to claim 12, characterized in that The step of discharging the battery under test in a second mode comprises: Based on the second discharge rate, performing constant current discharge on the battery to be tested; Among them, the second discharge rate D2 satisfies: 0 D2 , Cn is a preset capacity value or the remaining capacity of the battery to be tested measured in the previous warning value determination process.

14. The method according to claim 12, characterized in that After the battery to be tested is discharged in the second mode until the power level of the battery to be tested reaches a minimum voltage, the method further includes: Performing a third mode charging on the battery to be tested until the battery to be tested reaches a second preset state of charge; The second preset state of charge SOC2 satisfies: 90% SOC2 .

15. The method according to claim 14, characterized in that The charging of the battery to be tested in the third mode includes: Based on the second charging rate, the battery to be tested is charged with a constant current; Among them, the second charging rate A2 satisfies: 0 A2 Cn is a preset capacity value or the remaining capacity of the battery to be tested measured in the previous warning value determination process.

16. A battery risk warning device, characterized in that: include: A first acquisition module, used to perform a first mode charging on a battery to be tested at a preset power level, and to acquire first charging data of the battery to be tested in the first mode charging; A second acquisition module, used to perform a second mode charging on the battery to be tested after being charged in the first mode, and to obtain second charging data of the battery to be tested in the second mode charging; A first determining module, configured to determine a current warning value of the battery to be tested based on the first charging data and the second charging data; The second determining module is configured to determine that the battery to be tested is in a risky state in response to the current warning value and the historical warning value of the battery to be tested satisfying a preset warning condition.

17. A computing device, characterized in that include: at least one processor; as well as At least one memory is communicatively connected to the at least one processor, the at least one memory stores instructions, and when the instructions are executed by the at least one processor individually or collectively, the computing device performs the method of any one of claims 1 to 15.

18. A computer-readable storage medium, characterized in that: Instructions are stored, which, when executed individually or collectively by one or more processors of a computing device, cause the computing device to perform the method of any one of claims 1 to 15.

19. A computer program product, characterized in that The method comprises instructions which, when executed individually or collectively by one or more processors of a computing device, cause the computing device to perform the method of any one of claims 1 to 15.

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