CN116754946B

CN116754946B - Battery stability evaluation method, device, equipment, storage medium and system

Info

Publication number: CN116754946B
Application number: CN202311048467.9A
Authority: CN
Inventors: 冯婷; 徐飘雪; 王少飞; 魏奕民
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2023-08-21
Filing date: 2023-08-21
Publication date: 2024-04-02
Anticipated expiration: 2043-08-21
Also published as: CN116754946A

Abstract

The embodiment of the application provides a battery stability evaluation method, device, equipment, storage medium and system. The method comprises the following steps: charging the to-be-measured battery subjected to standing treatment, and determining an electric quantity loss value based on a first charging quantity of the to-be-measured battery; evaluating the stability of the battery to be tested according to the electric quantity loss value and the comparison electric quantity loss value; the reference electric quantity loss value is determined based on the amount of charge obtained by charging the reference battery subjected to the stationary treatment. Because the battery to be tested can generate oxidation reaction in the process of standing, the oxidation reaction can cause electric quantity loss, and the more the oxidation reaction is, the more the electric quantity loss is, the weaker the stability of the battery is, so that the electric quantity loss value can be determined by recharging the battery to be tested which is subjected to standing, then the stability of the battery to be tested is evaluated according to the electric quantity loss value, the test time is relatively short, and the time required for evaluating the stability of the battery is reduced.

Description

Battery stability evaluation method, device, equipment, storage medium and system

Technical Field

The present application relates to the field of battery technologies, and in particular, to a method, an apparatus, a device, a storage medium, and a system for evaluating battery stability.

Background

The stability of a battery is an important parameter for battery safety evaluation, and therefore, during the development of a battery, the stability of the battery is evaluated to determine whether the stability of the battery meets the requirement.

The current method for evaluating the stability of the battery material is to charge and discharge the battery many times, which takes a long time, and the efficiency of evaluating the stability of the battery material is low.

Disclosure of Invention

An embodiment of the application aims to provide a battery stability evaluation method, device, electronic equipment, storage medium and system, which are used for reducing the time required for battery stability evaluation.

In a first aspect, an embodiment of the present application provides a battery stability evaluation method, including:

charging the to-be-measured battery subjected to standing treatment, and determining an electric quantity loss value based on a first charging quantity for charging the to-be-measured battery;

evaluating the stability of the battery to be tested according to the electric quantity loss value and the comparison electric quantity loss value; wherein the reference electric quantity loss value is determined based on a charge quantity obtained by charging the reference battery subjected to the stationary treatment.

In this embodiment of the present application, since the battery to be measured is in the process of standing, the oxidation reaction will occur in the battery, and this oxidation reaction will result in electric quantity loss, and, the more the oxidation reaction is, the weaker the stability of the battery, therefore, the battery to be measured through standing can be recharged, thereby determining the electric quantity loss value, then the stability of the battery to be measured is evaluated according to the electric quantity loss value, and the test time is relatively short, thereby reducing the time period required for evaluating the stability of the battery.

In any embodiment, before charging the battery to be tested subjected to the standing treatment, the method further comprises:

charging the voltage of the initial battery to a preset cut-off voltage; the initial battery charged to the preset cut-off voltage is taken as the battery to be tested before standing and charging;

charging the to-be-measured battery subjected to the standing treatment, comprising:

and charging the voltage of the battery to be tested to the cut-off voltage according to the charging parameter for charging the initial battery.

In this embodiment of the present application, since the batteries are charged to the same cut-off voltage by using different charging parameters, the amounts of electricity charged into the batteries are also different, so that the to-be-measured battery is charged according to the charging parameters for charging the initial battery, thereby reducing the error in calculating the electric quantity loss value.

In any embodiment, evaluating the stability of the battery to be tested according to the power loss value and the control power loss value includes:

and comparing the electric quantity loss value with the control electric quantity loss value, and determining the stability of the battery to be detected to be higher than that of the control battery according to the comparison result.

According to the embodiment of the application, the electric quantity loss value is compared with the control electric quantity loss value, so that the stability of the battery to be tested can be qualitatively estimated to be higher than that of the control battery.

obtaining electric quantity deviation of the electric quantity loss value and the comparison electric quantity loss value;

and determining the stability index of the battery to be tested according to the electric quantity deviation and the stability index of the control battery.

According to the embodiment of the application, the stability index of the battery to be tested is determined through the electric quantity deviation of the electric quantity loss value and the comparison electric quantity loss value and the stability index of the comparison battery, so that the quantitative evaluation of the stability of the battery to be tested is realized.

In any embodiment, determining the charge loss value based on the first charge amount includes:

recording the charging time length and the current value in the charging process;

Determining a first charge amount according to the charge duration and the current value;

the first charge amount is determined as a power loss value.

According to the method and the device for evaluating the stability of the battery, the first charging amount is obtained through calculation of the charging duration and the current value corresponding to each time period in the charging process, and the battery to be tested can undergo oxidation reaction in the standing process to cause electric quantity loss, so that the electric quantity loss value can be obtained according to the first charging amount of the battery to be tested, and the efficiency of evaluating the stability of the battery is improved.

In any embodiment, the standing process comprises:

standing the battery to be tested for a preset period of time;

discharging the battery to be tested after standing for a preset period of time, and recording the discharge amount after the discharge is finished;

determining a charge loss value based on the first charge amount includes:

charging the battery to be measured after discharging to a voltage value before standing to obtain a first charge amount;

and determining a power loss value according to the discharge amount and the first charge amount.

The embodiment of the application provides another mode for determining the electric quantity loss value, namely, the battery is firstly kept stand for a preset time period, oxidation reaction occurs in the battery to be tested in the standing process, electric quantity loss is caused, after the battery to be tested is kept stand for a preset time period, the battery to be tested is discharged, after discharging is completed, the battery is charged to a voltage value before the battery is kept stand again, then in the electric quantity loss value determined according to the discharging quantity and the first charging quantity, the influence of electric quantity loss caused by negative electrode reduction on electric quantity loss value calculation can be reduced, and the accuracy of electric quantity loss value calculation is improved.

In any embodiment, determining the charge loss value from the discharge amount and the first charge amount includes:

obtaining an electric quantity difference value between the first charge quantity and the discharge quantity;

and determining the electric quantity difference value as an electric quantity loss value.

According to the method and the device for calculating the electric quantity loss value, the influence of the electric quantity loss caused by negative electrode reduction on the calculation of the electric quantity loss value can be reduced through the electric quantity loss value determined according to the discharge quantity and the first charge quantity, and the accuracy of the calculation of the electric quantity loss value is improved.

In any embodiment, before the battery to be tested is left to stand for a preset period of time, the method further comprises:

charging the battery to be tested after discharging to a voltage value before standing, comprising:

and charging the voltage of the battery to be tested after the discharge is finished to the cut-off voltage again according to the charging parameters for charging the initial battery.

According to the method and the device, the batteries are charged to the same cut-off voltage by utilizing different charging parameters, and the electric quantity charged into the batteries is different, so that the voltage of the battery to be tested after the discharge is finished is charged to the cut-off voltage again according to the charging parameters used when the initial battery is charged, and the error of calculating the electric quantity loss value can be reduced.

In any embodiment, the battery to be tested is different from the battery material in the control battery; the battery material comprises a positive electrode plate or electrolyte.

The evaluation method provided by the embodiment of the application can evaluate the oxidation resistance of the positive electrode plate and also evaluate the oxidation resistance of the electrolyte.

In a second aspect, embodiments of the present application provide another battery stability assessment method, including:

charging the voltage values of a plurality of initial batteries to a preset cut-off voltage, wherein the charging parameters of the initial batteries are the same;

recharging the voltage values of the batteries to be tested subjected to the standing treatment to the cut-off voltage according to the charging parameters, and recording a second charging amount; the initial batteries are subjected to standing treatment to form batteries to be tested, and positive pole pieces corresponding to the batteries to be tested are different;

determining a power loss value according to the second charge amount;

and evaluating the stability of the positive pole piece of the battery to be tested according to the electric quantity loss values respectively corresponding to the plurality of batteries to be tested.

In this embodiment of the present application, since the positive electrode piece of the battery to be measured is subjected to an oxidation reaction in the standing process, the oxidation reaction may cause electric quantity loss, and the more the oxidation reaction is, the weaker the stability of the battery is, so that the electric quantity loss value can be determined by recharging the battery to be measured that is subjected to standing, and then the stability of the battery to be measured is evaluated according to the electric quantity loss value, and the test time is relatively short.

In a third aspect, embodiments of the present application provide a battery stability evaluation method, including:

charging the voltage values of the plurality of initial batteries to a preset cut-off voltage, wherein the charging parameters of the plurality of initial batteries are the same;

recharging the voltage values of the batteries to be tested subjected to the standing treatment to the cut-off voltage according to the charging parameters, and recording a third charging amount; the initial batteries are subjected to standing treatment to form batteries to be tested, and electrolyte corresponding to the batteries to be tested is different;

determining a power loss value according to the third charge amount;

and evaluating the stability of the electrolyte of the battery to be tested according to the electric quantity loss values respectively corresponding to the plurality of batteries to be tested.

In this embodiment of the present application, since the electrolyte of the battery to be measured is subjected to an oxidation reaction in the standing process, the oxidation reaction may cause electric quantity loss, and the more the oxidation reaction is, the more the electric quantity loss is, the weaker the stability of the battery is, so that the electric quantity loss value can be determined by recharging the battery to be measured that is subjected to standing, and then the stability of the battery to be measured is evaluated according to the electric quantity loss value, and the test time is relatively short.

In a fourth aspect, embodiments of the present application provide a battery stability evaluation device, including:

The electric quantity measurement module is used for charging the battery to be measured after standing treatment, and determining an electric quantity loss value based on a first charging quantity of the battery to be measured;

the evaluation module is used for evaluating the stability of the battery to be tested according to the electric quantity loss value and the comparison electric quantity loss value;

wherein the reference electric quantity loss value is determined based on a charge quantity obtained by charging the reference battery subjected to the stationary treatment.

In a fifth aspect, embodiments of the present application provide a battery stability evaluation apparatus, including: a processor, a memory, and a bus, wherein,

the processor and the memory complete communication with each other through the bus;

the memory stores program instructions executable by the processor, the processor invoking the program instructions to enable the method of the first aspect or the second aspect or the third aspect to be performed.

In a sixth aspect, embodiments of the present application provide a non-transitory computer readable storage medium comprising:

the non-transitory computer readable storage medium stores computer instructions that cause the computer to perform the method of the first aspect or the second aspect or the third aspect.

In a seventh aspect, embodiments of the present application provide a battery stability assessment system, comprising: a charging power supply and the battery stability evaluation apparatus as described in the fifth aspect; wherein:

The charging power supply is used for charging the battery to be tested;

the battery stability evaluation device is used for calculating the electric quantity loss value of the battery to be tested and evaluating the stability of the battery to be tested according to the electric quantity loss value.

Additional features and advantages of the application will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the embodiments of the application. The objectives and other advantages of the application will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic flow chart of a battery stability evaluation method according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a battery loss provided in an embodiment of the present application;

Fig. 3 is a schematic flow chart of another battery stability evaluation method according to an embodiment of the present disclosure;

FIG. 4 is a flowchart illustrating another method for evaluating battery stability according to an embodiment of the present disclosure;

fig. 5 is a schematic structural diagram of a battery stability evaluation device according to an embodiment of the present application;

fig. 6 is a schematic structural diagram of another battery stability evaluation device according to an embodiment of the present disclosure;

fig. 7 is a schematic structural diagram of another battery stability evaluation device according to an embodiment of the present disclosure;

fig. 8 is a schematic physical structure diagram of a battery stability evaluation device according to an embodiment of the present application;

fig. 9 is a schematic structural diagram of a battery stability evaluation system according to an embodiment of the present application;

fig. 10 is a schematic diagram of a test circuit according to an embodiment of the present application.

Detailed Description

Embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical solutions of the present application, and thus are only examples, and are not intended to limit the scope of protection of the present application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description and claims of the present application and in the description of the figures above are intended to cover non-exclusive inclusions.

In the description of the embodiments of the present application, the technical terms "first," "second," etc. are used merely to distinguish between different objects and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, a particular order or a primary or secondary relationship. In the description of the embodiments of the present application, the meaning of "plurality" is two or more unless explicitly defined otherwise.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

In the description of the embodiments of the present application, the term "and/or" is merely an association relationship describing an association object, which means that three relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

In the description of the embodiments of the present application, the term "plurality" refers to two or more (including two), and similarly, "plural sets" refers to two or more (including two), and "plural sheets" refers to two or more (including two).

In the description of the embodiments of the present application, the orientation or positional relationship indicated by the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of describing the embodiments of the present application and for simplifying the description, rather than indicating or implying that the apparatus or element referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the embodiments of the present application.

In the description of the embodiments of the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured" and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally formed; or may be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the embodiments of the present application will be understood by those of ordinary skill in the art according to the specific circumstances.

The stability of a battery is an important index for evaluating the safety of a battery, and in order to produce a battery with better safety, the stability of the battery needs to be evaluated in the research and development stage. In general, the stability of a battery to be evaluated can be evaluated by means of cyclic charge and discharge, but this method requires a long time, which is disadvantageous for accelerating the development cycle. It is understood that the stability of the positive electrode sheet according to the embodiments of the present application may be characterized by the oxidation resistance of the positive electrode sheet, and the stability of the electrolyte may be characterized by the oxidation resistance of the electrolyte.

In order to solve the above technical problems, the embodiments of the present application provide a method, an apparatus, a device, a storage medium, and a system for evaluating battery stability. After the battery to be measured is subjected to standing treatment, the battery to be measured is recharged to the voltage before standing, so that the electric quantity loss of the battery to be measured in the standing process can be calculated, and the stability of the battery is evaluated based on the electric quantity loss. In this process, the time required for the evaluation is relatively short, and the evaluation efficiency is improved.

Fig. 1 is a schematic flow chart of a battery stability evaluation method according to an embodiment of the present application, as shown in fig. 1, where the method is applied to a battery stability evaluation device, and the method includes:

Step 101: charging the to-be-measured battery subjected to standing treatment, and determining an electric quantity loss value based on a first charging quantity of the to-be-measured battery;

step 102: and evaluating the stability of the battery to be tested according to the electric quantity loss value and the comparison electric quantity loss value.

In a specific implementation process, the battery to be tested can be a soft package battery, a battery core and the like, and comprises a positive pole piece, a negative pole piece, an isolating film and electrolyte. The standing treatment of the battery to be tested comprises the steps of storing the battery to be tested in an incubator with a certain temperature, wherein the standing time can be set according to actual conditions, and the battery to be tested can be stored for 1 day, 1.5 days, 2 days or 3 days, etc. It should be noted that the battery to be measured may be placed in a room temperature or the like.

In the process of charging the to-be-measured battery subjected to the standing treatment, a certain multiplying power can be adopted for charging, a constant-voltage charging mode can be adopted for charging, constant-current charging can be adopted, constant voltage and constant current can be carried out firstly, or constant current and constant voltage can be carried out firstly, and specific charging parameters can be preset. And after the charging is completed, counting a first charging amount for charging the battery to be tested. It can be understood that the charging parameters also include a cut-off voltage, that is, the characteristic that the charging is completed when the voltage of the battery to be measured reaches the cut-off voltage. It should be noted that whether the charging is completed may be determined based on the voltage of the battery to be measured before the standing process, for example: if the voltage of the battery to be tested is 5V before the standing treatment, the battery to be tested is charged to 5V, and the charging is completed. Therefore, the first charge amount charged into the battery to be measured is the electric quantity loss value during the standing period.

It can be understood that, the battery to be measured is in the process of standing still, positive pole oxidation reaction and negative pole reduction reaction can all take place for its inside, positive pole oxidation reaction and negative pole reduction reaction can make the electric quantity of battery to be measured take place the loss, and the electric quantity loss accessible that positive pole oxidation reaction leads to is charged again to the battery to be measured and is mended the electric quantity, and the electric quantity loss that negative pole reduction reaction leads to is irreversible, can't recharge, therefore, the electric quantity loss that the positive pole oxidation reaction leads to is measured through the mode that the accessible was charged to the battery to be measured again to this embodiment of the application, consequently, the electric quantity loss value in this application embodiment is referred to the battery to be measured in the process of standing still, mainly because the electric quantity loss that positive pole oxidation reaction leads to. And the electric quantity loss value and the stability of the battery to be tested are in a negative correlation relationship, so that the stability of the battery to be tested can be evaluated through the electric quantity loss value.

In addition, the comparison battery can be an existing battery, after the electric quantity loss value of the battery to be detected is obtained, the electric quantity loss value of the battery to be detected can be compared with the comparison electric quantity loss value of the comparison battery, so that whether the stability of the battery to be detected is higher than that of the comparison battery can be obtained. The method for obtaining the reference electric quantity loss value of the reference battery is the same as the method for obtaining the electric quantity loss value of the battery to be measured, namely, the reference battery after standing treatment is charged, and the reference electric quantity loss value is obtained. It should be noted that the voltage of the reference battery before the standing process may be the same as the voltage of the battery to be measured before the standing process, and the environmental factors (e.g., temperature) of the battery to be measured and the reference battery during the standing process may be the same, so that the accuracy of the stability evaluation of the battery to be measured may be improved.

In another case, the reference battery may be other batteries than the battery to be measured among the plurality of batteries participating in the evaluation, wherein any one of the plurality of batteries participating in the evaluation may be used as the battery to be measured, and the test environments of the plurality of batteries participating in the evaluation are the same when the evaluation is performed, so that the stability condition of the battery to be measured among the plurality of batteries participating in the evaluation may be determined according to the electric quantity loss value of the battery to be measured and the reference electric quantity loss value, for example: it is possible to determine whether the stability of the battery to be measured among the plurality of batteries is the weakest, or is in the middle, or is the highest.

In this embodiment of the present application, since the battery to be measured is in the process of standing, the oxidation reaction will occur in the battery, and this oxidation reaction will result in electric quantity loss, and, the more the oxidation reaction is, the lower the stability of the battery, therefore, the battery to be measured through standing can be recharged, thereby determining the electric quantity loss value, then the stability of the battery to be measured is evaluated according to the electric quantity loss value, the test time is relatively short, thereby reducing the time period required for evaluating the stability of the battery.

On the basis of the above embodiment, before charging the battery to be measured subjected to the standing treatment, the method further includes:

Charging the voltage of the initial battery to a preset cut-off voltage; the method comprises the steps of standing an initial battery charged to a preset cut-off voltage to form a battery to be tested;

In a specific implementation process, the battery before standing and charging is called an initial battery, and the battery obtained after charging and standing the initial battery is the battery to be tested. The cut-off voltage is preset, and when the voltage of the initial battery reaches the cut-off voltage in the process of charging the initial battery, the initial battery can be stopped from being charged. The determination method of the cut-off voltage may be: the voltage corresponding to the state of charge of the battery to be tested is taken as the cut-off voltage, or the voltage corresponding to the state of charge of 90% or 85% can be taken as the cut-off voltage, and the cut-off voltage can be specifically set according to actual test requirements.

After the initial battery is charged, the initial battery is left to stand for processing such as: the initial battery may be placed in an incubator at a preset temperature for a preset period of time. It will be appreciated that the temperature in the incubator may be a constant value or may vary over time, and may be specifically set according to the actual test requirements. The initial battery and the control battery may be placed in the same incubator for the same period of time, thereby reducing the impact of the environment on the battery stability assessment.

Fig. 2 is a schematic diagram of a battery loss provided in the embodiment of the present application, as shown in fig. 2, the voltage of the initial battery may be charged to a voltage corresponding to 100% soc, and then the initial battery is allowed to stand for t days, where the value of t is 1, 2, 3, etc. During the standing period, positive electrode oxidation reaction and negative electrode reduction reaction are generated in the initial battery, and the two reactions can lead to electric quantity loss, so that after t days of standing, the SOC of the battery to be tested becomes x%, wherein x is less than 100, and in the standing period, the electric quantity loss caused by the negative electrode reduction reaction cannot be recovered through recharging, namely, the electric quantity loss caused by the negative electrode reduction is irreversible electric quantity loss of the battery; the positive electrode oxidation reaction can be repaired by charging, so that the battery to be tested can be charged, and in order to improve the reversible electric quantity loss value, the battery to be tested is charged according to the charging parameters used in the process of charging the initial battery during charging, and the voltage of the battery to be tested before standing is reached.

On the basis of the above embodiment, evaluating the stability of the battery to be tested according to the electric quantity loss value and the control electric quantity loss value includes:

In a specific implementation process, comparing the electric quantity loss value of the battery to be detected with the comparison electric quantity loss value of the comparison battery, and if the electric quantity loss value is larger than the comparison electric quantity loss value, indicating that the oxidation reaction of the battery to be detected is larger in the standing process, wherein the stability of the battery to be detected is lower than that of the comparison battery; otherwise, if the electric quantity loss value is smaller than the reference electric quantity loss value, the fact that the oxidation reaction of the battery to be tested is smaller in the standing process is indicated, and the stability of the battery to be tested is higher than that of the reference battery.

In a specific implementation, the stability indicator is one way to evaluate the quantitative evaluation stability level, for example, the stability indicator may include multiple levels, different levels are used to characterize the stability of the battery, and the stability indicator is assumed to include level 1, level 2, level 3, and level 4, where the higher the level, the higher the stability. It should be noted that the number of levels corresponding to the stability index may be more or less, for example, may be 3 levels, may be 5 levels, or the like. The level and the stability may be set according to the actual situation, that is, the lower the level of the index is, the higher the stability of the battery is.

In order to quantitatively evaluate the stability of the battery to be tested, a relationship between the power deviation and the stability index may be preset, for example: the electric quantity deviation is between (0-2 mAh), the stability index is reduced by one grade, the current deviation is between (2 mAh,4 mAh), the stability index is reduced by two grades, the current deviation is between (-2 mAh,0 uA), the stability index is increased by one grade, the current deviation is between (-4 mAh, -2 mAh), the stability index is increased by two grades, and so on.

The stability index includes 4 grades, and the higher the grade is, the higher the stability of the battery is, the index of the stability of the control battery is 2 grades, and the current deviation corresponding to the change between adjacent grades is a fixed value of 2 mAh. After the battery stability evaluation device obtains the electric quantity loss value and the comparison electric quantity loss value, the electric quantity loss value can be subtracted from the comparison electric quantity loss value, and electric quantity deviation is obtained. It can be understood that if the electric quantity deviation is positive, it indicates that the electric quantity loss value is higher than the reference electric quantity loss value, and the stability of the battery to be measured is lower than that of the reference battery; and if the electric quantity deviation is negative, the electric quantity loss value is lower than the comparison electric quantity loss value, and the stability of the battery to be tested is higher than that of the comparison battery. If the electric quantity deviation between the electric quantity loss value and the comparison electric quantity loss value is-3 mAh, the stability index of the battery to be tested can be determined to be 2 grades higher than the stability index of the comparison battery, namely the stability index of the battery to be evaluated is 4 grades.

On the basis of the above embodiment, determining the charge amount loss value based on the first charge amount includes:

obtaining a charging duration and a current value in a charging process;

the first charge amount is determined as a power loss value.

In a specific implementation process, the charging duration refers to a duration required for charging the voltage of the battery to be tested to the cut-off voltage. The current value in the charging process refers to the current value corresponding to each time point in the charging process. When the battery to be tested is charged, constant current can be adopted for charging, and constant voltage or constant current before constant voltage and the like can also be adopted. For the constant current charging mode, the current value flowing through the battery to be tested is unchanged in the charging process, so that the charging duration and the current value can be multiplied to obtain a first charging amount for charging the battery to be tested, and the first charging amount is the electric quantity loss value of the battery to be tested in the standing process. For the case that the current changes in the charging process, the first charge amount charged into the battery to be measured may be obtained according to the integral of the current values respectively corresponding to the respective time points in the charging process.

On the basis of the above embodiment, the standing process includes:

standing the battery to be tested for a preset period of time;

determining a charge loss value based on the first charge amount includes:

In a specific implementation process, another method for obtaining a power loss value is provided in the embodiments of the present application, which specifically includes the following steps:

the battery to be measured is firstly placed for a preset time period, and particularly the battery to be measured can be placed in an incubator with a certain temperature for storage, wherein the preset time period can be set according to actual conditions, and can be stored for 10 hours, 1 day, 1.5 days, 2 days or 3 days, and the like. It should be noted that the battery to be measured may be placed in a room temperature or the like. And after standing for a preset period of time, discharging the battery to be tested, and obtaining the discharge capacity after the discharge is finished. The cut-off voltage of the discharge may be set in advance, and may be a voltage corresponding to 10% soc, a voltage corresponding to 15% soc, a voltage corresponding to 30% soc, or the like of the battery to be measured. The cut-off voltage of the discharge is smaller than the voltage of the battery to be tested before standing.

And charging the battery to be tested after discharging is finished, so that the voltage of the battery to be tested returns to the voltage value before standing, and a first charge amount is obtained. The electric quantity loss value can be obtained by subtracting the discharge amount from the first charge amount.

The oxidation side reaction of the positive electrolyte in the battery can cause reversible electric quantity loss of the battery, and the reduction side reaction of the negative electrode can cause irreversible electric quantity loss. According to the embodiment of the application, the battery is firstly discharged, the discharge quantity represents the residual quantity of the battery to be measured after the reversible electric quantity loss and the irreversible electric quantity loss, the battery to be measured is charged, the reversible electric quantity loss can be recovered in the charging process, and the irreversible electric quantity loss cannot be recovered, so that the first charge quantity represents the residual quantity of the battery to be measured after the irreversible electric quantity loss value. Therefore, the difference between the first charge amount and the discharge amount is a reversible electric quantity loss, i.e., the oxidation amount of the positive electrode electrolyte. According to the embodiment of the application, the stability of the battery is measured through the oxidation amount of the positive electrode electrolyte, namely, the greater the oxidation amount of the positive electrode electrolyte is, the lower the stability of the battery is; the smaller the oxidation amount of the positive electrode electrolyte, the higher the stability of the battery.

The embodiment of the application provides another mode for determining the electric quantity loss value, namely, the battery is firstly kept stand for a preset time period, oxidation reaction occurs in the battery to be tested in the standing process, electric quantity loss is caused, after the battery to be tested is kept stand for a preset time period, the battery to be tested is discharged, after discharging is completed, the battery is charged to a voltage value before the battery is kept stand again, then the influence of electric quantity loss caused by negative electrode reduction on electric quantity loss value calculation can be reduced in the electric quantity loss value determined according to the discharging quantity and the first charging quantity, and the accuracy of electric quantity loss value calculation is improved.

On the basis of the above embodiment, before the battery to be tested is left to stand for a preset period of time, the method further includes:

After the initial battery is charged, the initial battery is left for a preset period of time, for example: the initial battery may be placed in an incubator at a preset temperature for a preset period of time. It will be appreciated that the temperature in the incubator may be a constant value or may vary over time, and may be specifically set according to the actual test requirements. The initial battery and the control battery may be placed in the same incubator for the same period of time, thereby reducing the impact of the environment on the battery stability assessment.

The battery after standing for a preset period of time is called a battery to be tested, and because the battery is charged to the same cut-off voltage by utilizing different charging parameters, the electric quantity charged into the battery is different, and therefore, the battery to be tested is charged according to the charging parameters for charging the initial battery, the error for calculating the electric quantity loss value can be reduced, and the accuracy of stability assessment of the battery to be tested is improved.

On the basis of the embodiment, the battery materials in the battery to be tested and the battery materials in the control battery are different; the battery material comprises a positive electrode piece or electrolyte.

In a specific implementation process, the battery stability evaluation method disclosed by the embodiment of the application can be used for evaluating the stability of the positive electrode plate or electrolyte in the battery, and the stability of the battery is reflected by the stability of the positive electrode plate or the electrolyte. When the stability of the positive electrode plate is evaluated, the positive electrode plate of the battery to be evaluated is different from the positive electrode plate of the control battery, and other components of the battery are the same, wherein the other components include, but are not limited to, electrolyte, a negative electrode plate and the like. Similarly, when evaluating the stability of the electrolyte, the electrolyte of the battery to be evaluated is different from the electrolyte of the control battery, and the other components of the battery are the same, wherein the other components include, but are not limited to, a positive electrode sheet, a negative electrode sheet, and the like.

The stability of the positive electrode plate and the stability of the electrolyte are both one of the stability of the battery, so that the stability of the positive electrode plate can be evaluated by the evaluation method provided by the embodiment of the application, and the stability of the electrolyte can also be evaluated, so that the stability of the battery is evaluated. It should be noted that other materials that have an effect on the oxidation reaction inside the battery may also be used to evaluate the stability of the battery.

Fig. 3 is a schematic flow chart of another method for evaluating stability of a battery according to an embodiment of the present application, as shown in fig. 3, where the method is used for evaluating stability of a positive electrode plate of a battery to be tested. It can be understood that the stability of the positive electrode sheet can reflect the stability of the battery, the stronger the stability, the higher the stability of the battery; the weaker the stability, the lower the stability of the battery. The method comprises the following steps:

step 301: charging the voltage values of the plurality of initial batteries to a preset cut-off voltage, wherein the charging parameters of the plurality of initial batteries are the same;

step 302: recharging the voltage values of the batteries to be tested subjected to the standing treatment to the cut-off voltage according to the charging parameters, and recording a second charging amount; the initial batteries are subjected to standing treatment to form batteries to be tested, and positive pole pieces corresponding to the batteries to be tested are different;

Step 303: determining a power loss value according to the second charge amount;

step 304: and evaluating the stability of the positive pole piece of the battery to be tested according to the electric quantity loss values respectively corresponding to the plurality of batteries to be tested.

In a specific implementation process, the battery type of the battery to be tested may be: liNi _0.5 Mn _1.5 O ₄ (lithium nickel manganese oxide)/graphite cell (abbreviated as LNMO/Gr cell); 1.2Ah soft package battery, wherein the storage temperature of the battery in the standing process is 60 ℃, and the storage charge state of the battery to be tested before standing is 100% SOC 4.9V; the standing time period was 3 days. The electrolyte of the battery to be tested is high-voltage-resistant electrolyte. The batteries to be tested comprise 3 batteries, wherein the positive pole piece of the battery A1 to be tested is made of LNMO material: LNMO; positive pole piece of battery A2 to be testedThe LNMO material is coated with alumina: LNMO-Al ₂ O ₃ (aluminum oxide coated lithium nickel manganese oxide); the positive pole piece of the battery A3 to be tested is made of titanium oxide coated LNMO material: LNMO-TiO ₂ (titanium oxide-coated lithium nickel manganese oxide).

And charging the initial batteries corresponding to the three batteries to be tested respectively according to the same charging parameters, so that the voltage of the initial batteries reaches the cut-off voltage. The charging parameters may include multiplying power and charging mode (e.g., constant current, constant voltage, constant current followed by constant voltage, constant voltage followed by constant current, etc.). After the initial battery is charged, the initial battery is placed in the same environment for the same time period. The initial battery after being placed for a preset period of time is called a battery to be tested. And charging the battery to be tested again according to the charging parameters for charging the initial battery, so that the voltage of the battery to be tested reaches the cut-off voltage again, and recording the second charging amount. The second charging amount for charging each battery to be tested is the electric quantity loss value Qc of the battery to be tested, and in order to verify the feasibility of the battery stability evaluation method provided by the embodiment of the application, the experiment also measures the gas yield of the three batteries to be tested, because the gas yield is also an index for representing the magnitude of side reaction occurring in the battery, that is, the larger the gas yield is, the larger the side reaction in the battery is, and the lower the battery stability is. Experimental data are as follows:

From the above table, the stability ranks of the three batteries to be tested are A2< A1< A3.

It should be noted that the materials of the positive electrode sheet may be other, and the above listed materials of the positive electrode sheet are only examples.

Fig. 4 is a schematic flow chart of another method for evaluating the stability of an electrolyte of a battery to be evaluated, as shown in fig. 4, where it is understood that the stability of the electrolyte may reflect the stability of the battery, and the stronger the stability, the higher the stability of the battery; the weaker the stability, the lower the stability of the battery. The method comprises the following steps:

step 401: charging the voltage values of the plurality of initial batteries to a preset cut-off voltage, wherein the charging parameters of the plurality of initial batteries are the same;

Step 402: recharging the voltage values of the batteries to be tested subjected to the standing treatment to the cut-off voltage according to preset charging parameters, and recording a third charging amount; the initial batteries are subjected to standing treatment to form batteries to be tested, and electrolyte corresponding to the batteries to be tested is different;

step 403: determining a power loss value according to the third charge amount;

step 404: and evaluating the stability of the electrolyte of the battery to be tested according to the electric quantity loss values respectively corresponding to the plurality of batteries to be tested.

In a specific implementation process, the battery type of the battery to be tested is as follows: ternary NCM 811/graphite cell; 840mAh soft package battery; the storage temperature of the battery in the standing process is 65 ℃; the storage charge state of the battery to be tested before standing is 100% SOC 4.2V (100% SOC); the standing time period was 7 days. Base electrolyte: 1M LiPF6 (lithium hexafluorophosphate) EC (ethylene carbonate)/EMC (ethylmethyl carbonate) (3:7 wt% ratio), test cell EL1 with 1% DTD (ethylene sulfate) added to the Base electrolyte, test cell EL2 with 2% DTD added to the Base electrolyte, test cell EL3 with 2% VC (vinylene carbonate) +1% DTD added to the Base electrolyte, test cell EL4 with 4% PS (1, 3-propane sultone) added to the Base electrolyte, test cell EL5 with 1% LiBOB (lithium bisoxalato borate) +2% VC added to the Base electrolyte, test cell EL6 with 2% VC added to the Base electrolyte, test cell EL7 with 2% VC+1% DTD+1% TTSPi (tris (trimethylsilyl) -phosphite) added to the Base electrolyte.

The numbers of the batteries to be tested are marked as EL1, EL2, EL3 and EL4, and the components of the four groups of batteries to be tested are consistent except that the electrolyte is different.

The specific test flow is as follows:

step 1: the batteries EL1, EL2, EL3, EL4, EL5, EL6, EL7 to be tested are charged with the same charging parameters to a preset cut-off voltage.

Step 2: and after the charging is finished, taking down the test battery, and placing the battery to be tested in an incubator with the same temperature for storage, wherein the storage time is t days.

Step 3: taking out the battery to be tested after the storage time is reached, and charging again by using the same charging parameters as those in the step 1 until the battery to be tested is charged to the same cut-off voltage;

step 4: obtaining third charge amounts respectively corresponding to the batteries to be detected, and respectively marking the third charge amounts as Q1, Q2, Q3, Q4, Q5, Q6 and Q7; the third charge amount may characterize a loss of charge due to a positive electrode oxidation side reaction. In order to verify the feasibility of the battery stability assessment method provided by the embodiment of the application, the experiment also measures the gas yield of the battery to be tested, because the gas yield is also an index for representing the side reaction occurring in the battery, namely, the larger the gas yield is, the larger the side reaction in the battery is, and the lower the battery stability is. Experimental data are as follows:

From the above table, it can be seen that Q_EL4> Q_EL5> Q_EL1> Q_EL2> Q_EL6> Q_EL3> Q_EL7; the electrolyte oxidation resistance is described as follows: EL7> EL3> EL6> EL2> EL1> EL5> EL4, and further the battery stability ranking is also: EL7> EL3> EL6> EL2> EL1> EL5> EL4.

Fig. 5 is a schematic structural diagram of a battery stability evaluation device according to an embodiment of the present application, where the device may be a module, a program segment, or a code on an electronic device. It should be understood that the apparatus corresponds to the embodiment of the method of fig. 1 described above, and is capable of performing the steps involved in the embodiment of the method of fig. 1, and specific functions of the apparatus may be referred to in the foregoing description, and detailed descriptions thereof are omitted herein as appropriate to avoid redundancy. The device comprises: a power measurement module 501 and an evaluation module 502, wherein:

The electric quantity measurement module 501 is configured to charge the battery to be measured after the standing process, and determine an electric quantity loss value based on a first charge amount for charging the battery to be measured;

the evaluation module 502 is configured to evaluate the stability of the battery to be tested according to the electric quantity loss value and a reference electric quantity loss value;

On the basis of the above embodiment, the apparatus further includes a first precharge module for:

charging the voltage of the initial battery to a preset cut-off voltage; the initial battery charged to a preset cut-off voltage is subjected to standing treatment to form the battery to be tested;

the power measurement module 501 is specifically configured to:

Based on the above embodiment, the evaluation module 502 is specifically configured to:

and comparing the electric quantity loss value with a control electric quantity loss value, and determining the stability of the battery to be tested to be higher than that of the control battery according to a comparison result.

Obtaining the electric quantity deviation of the electric quantity loss value and the comparison electric quantity loss value;

and determining the index of the stability of the battery to be tested according to the electric quantity deviation and the index of the stability of the control battery.

Based on the above embodiment, the power measurement module 501 is specifically configured to:

obtaining a charging duration and a current value in a charging process;

determining the first charge amount according to the charge duration and the current value;

the first charge amount is determined as the electric quantity loss value.

On the basis of the above embodiment, the standing process includes:

standing the battery to be tested for a preset period of time;

the power measurement module 501 is specifically configured to:

charging the battery to be measured after discharging to a voltage value before standing to obtain the first charge quantity;

and determining the electric quantity loss value according to the discharge quantity and the first charge quantity.

and determining the electric quantity difference value as the electric quantity loss value.

On the basis of the above embodiment, the apparatus further includes a second precharge module for:

the power measurement module 501 is specifically configured to:

On the basis of the above embodiment, the battery to be measured is different from the battery material in the control battery; the battery material comprises a positive electrode plate or electrolyte.

Fig. 6 is a schematic structural diagram of another battery stability assessment apparatus provided in an embodiment of the present application, where the apparatus may be a module, a program segment, or a code on an electronic device. It should be understood that the apparatus corresponds to the above embodiment of the method of fig. 3, and is capable of executing the steps involved in the embodiment of the method of fig. 3, and specific functions of the apparatus may be referred to in the above description, and detailed descriptions thereof are omitted herein as appropriate to avoid redundancy. The device comprises: a third pre-charge module 601, a first recharging module 602, a first charge loss determination module 603, and a pole piece stability evaluation module 604, wherein:

The third pre-charging module 601 is configured to charge voltage values of a plurality of initial batteries to a preset cutoff voltage, where charging parameters of charging the plurality of initial batteries are the same;

the first recharging module 602 is configured to recharge the voltage value of the battery to be measured after the standing process to the cut-off voltage according to the charging parameter, and record a second charging amount; the initial battery is subjected to standing treatment to form the battery to be tested, and positive pole pieces corresponding to a plurality of batteries to be tested are different;

the first power loss determination module 603 is configured to determine a power loss value according to the second charge amount;

the pole piece stability evaluation module 604 is configured to evaluate stability of the positive pole piece of the to-be-tested battery according to the electric quantity loss values corresponding to the to-be-tested batteries respectively.

Fig. 7 is a schematic structural diagram of another battery stability assessment apparatus provided in an embodiment of the present application, where the apparatus may be a module, a program segment, or a code on an electronic device. It should be understood that the apparatus corresponds to the embodiment of the method of fig. 4 described above, and is capable of performing the steps involved in the embodiment of the method of fig. 4, and specific functions of the apparatus may be referred to in the foregoing description, and detailed descriptions thereof are omitted herein as appropriate to avoid redundancy. The device comprises: a fourth precharge module 701, a second recharge module 702, a second charge loss determination module 703, and a pole piece stability evaluation module 704, wherein:

The fourth pre-charging module 701 is configured to charge the voltage values of a plurality of initial batteries to a preset cutoff voltage, where charging parameters of charging the plurality of initial batteries are the same;

the second recharging module 702 is configured to recharge the voltage values of the plurality of batteries to be measured after the standing process to the cut-off voltage according to the charging parameter, and record a third charging amount; the initial battery is subjected to standing treatment to form the battery to be tested, and electrolyte corresponding to a plurality of batteries to be tested is different;

the second power loss determination module 703 is configured to determine a power loss value according to the third charge amount;

the electrolyte stability evaluation module 704 is configured to evaluate the stability of the electrolyte of the to-be-measured battery according to the electric quantity loss values corresponding to the to-be-measured batteries respectively.

Fig. 8 is a schematic physical structure diagram of a battery stability evaluation device according to an embodiment of the present application, as shown in fig. 8, where the battery stability evaluation device includes: a processor (processor) 801, a memory (memory) 802, and a bus 803; wherein,

the processor 801 and memory 802 communicate with each other via the bus 803;

the processor 801 is configured to invoke program instructions in the memory 802 to perform the methods provided by the method embodiments described above.

The processor 801 may be an integrated circuit chip with signal processing capabilities. The processor 801 may be a general-purpose processor including a central processing unit (Central Processing Unit, CPU), a network processor (Network Processor, NP), and the like; but also Digital Signal Processors (DSPs), application Specific Integrated Circuits (ASICs), field Programmable Gate Arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. Which may implement or perform the various methods, steps, and logical blocks disclosed in embodiments of the present application. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

Memory 802 may include, but is not limited to, random access Memory (Random Access Memory, RAM), read Only Memory (ROM), programmable Read Only Memory (Programmable Read-Only Memory, PROM), erasable Read Only Memory (Erasable Programmable Read-Only Memory, EPROM), electrically erasable Read Only Memory (Electrically Erasable Programmable Read-Only Memory, EEPROM), and the like.

The present embodiments disclose a computer program product comprising a computer program stored on a non-transitory computer readable storage medium, the computer program comprising program instructions which, when executed by a computer, are capable of performing the methods provided by the method embodiments described above.

The present embodiment provides a non-transitory computer-readable storage medium storing computer instructions that cause a computer to perform the methods provided by the above-described method embodiments.

Fig. 9 is a schematic structural diagram of a battery stability evaluation system according to an embodiment of the present application, as shown in fig. 9, the system includes a charging power source 901 and a battery stability evaluation device 902, where:

the charging power supply is used for charging the battery to be tested;

the battery stability evaluation device is used for calculating a power loss value of the battery to be tested, and evaluating the stability of the battery to be tested according to the power loss value, and can be seen in the above embodiments of the method.

Fig. 10 is a schematic diagram of a test circuit provided in the embodiment of the present application, as shown in fig. 10, when calculating a power loss value, the ammeter 903 may be used to measure a current value of the charging power supply 901 flowing through the battery to be tested during the process of charging the battery to be tested, and send the measured current value to the battery stability evaluation device 902.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. The above-described apparatus embodiments are merely illustrative, for example, the division of the units is merely a logical function division, and there may be other manners of division in actual implementation, and for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be through some communication interface, device or unit indirect coupling or communication connection, which may be in electrical, mechanical or other form.

Further, the units described as separate units may or may not be physically separate, and units displayed as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

Furthermore, functional modules in various embodiments of the present application may be integrated together to form a single portion, or each module may exist alone, or two or more modules may be integrated to form a single portion.

In this document, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

The foregoing is merely exemplary embodiments of the present application and is not intended to limit the scope of the present application, and various modifications and variations may be suggested to one skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A battery stability evaluation method, characterized by comprising:

charging the to-be-measured battery subjected to the standing treatment to a preset cut-off voltage before the standing treatment, and determining an electric quantity loss value based on a first charging quantity for charging the to-be-measured battery;

evaluating the stability of the battery to be tested according to the electric quantity loss value and the control electric quantity loss value;

wherein the reference electric quantity loss value is determined based on a charge quantity obtained by charging the reference battery subjected to the stationary treatment;

the standing treatment includes:

standing the battery to be tested for a preset period of time;

the determining the power loss value based on the first charge amount for charging the battery to be measured includes:

determining the electric quantity loss value according to the discharge quantity and the first charge quantity;

the determining the electric quantity loss value according to the discharge quantity and the first charge quantity includes:

2. The method according to claim 1, wherein before charging the battery to be measured subjected to the standing treatment, the method further comprises:

the method for charging the to-be-measured battery subjected to the standing treatment comprises the following steps:

3. The method of claim 1, wherein the evaluating the stability of the battery under test based on the charge loss value and a control charge loss value comprises:

4. The method of claim 1, wherein the evaluating the stability of the battery under test based on the charge loss value and a control charge loss value comprises:

5. The method of claim 1, wherein prior to leaving the battery under test for a preset period of time, the method further comprises:

the method for charging the battery to be tested after discharging to the voltage value before standing comprises the following steps:

6. The method of any one of claims 1-5, wherein the battery to be tested is of a different material than the battery in the control battery; the battery material comprises a positive electrode plate or electrolyte.

7. A battery stability evaluation method, characterized by comprising:

Recharging the voltage values of the batteries to be tested subjected to the standing treatment to the cut-off voltage according to the charging parameters, and recording a second charging amount; the initial battery is subjected to standing treatment to form the battery to be tested, and positive pole pieces corresponding to a plurality of batteries to be tested are different;

determining a power loss value according to the second charge amount;

evaluating the stability of the positive pole piece of the battery to be tested according to the electric quantity loss values respectively corresponding to the batteries to be tested;

and recharging the voltage values of the plurality of batteries to be tested subjected to the standing treatment to the cut-off voltage according to the charging parameters, and recording a second charging amount, wherein the method comprises the following steps of:

standing the battery to be tested for a preset period of time;

charging the battery to be measured after discharging to a voltage value before standing to obtain the second charging amount;

the determining a power loss value according to the second charge amount includes:

obtaining an electric quantity difference value between the second charge quantity and the discharge quantity;

8. A battery stability evaluation method, characterized by comprising:

recharging the voltage values of the batteries to be tested subjected to the standing treatment to the cut-off voltage according to the charging parameters, and recording a third charging amount; the initial battery is subjected to standing treatment to form the battery to be tested, and electrolyte corresponding to a plurality of batteries to be tested is different;

determining a power loss value according to the third charge amount;

evaluating the stability of the electrolyte of the battery to be tested according to the electric quantity loss values respectively corresponding to the plurality of batteries to be tested;

and recharging the voltage values of the plurality of batteries to be tested subjected to the standing treatment to the cut-off voltage according to the charging parameters, and recording a third charging amount, wherein the method comprises the following steps of:

standing the battery to be tested for a preset period of time;

charging the battery to be tested after discharging to a voltage value before standing to obtain the third charge quantity;

the determining the power loss value according to the third charge amount includes:

obtaining an electric quantity difference value between the third charge quantity and the discharge quantity;

9. A battery stability evaluation device, characterized by comprising:

the electric quantity measurement module is used for charging the to-be-measured battery subjected to the standing treatment to a preset cut-off voltage before the standing treatment, and determining an electric quantity loss value based on a first charging quantity for charging the to-be-measured battery;

the evaluation module is used for evaluating the stability of the battery to be tested according to the electric quantity loss value and the control electric quantity loss value;

the standing treatment includes:

standing the battery to be tested for a preset period of time;

the electric quantity measuring module is specifically used for:

10. A battery stability evaluation apparatus, characterized by comprising: a processor, a memory, and a bus, wherein,

the memory stores program instructions executable by the processor, the processor invoking the program instructions to perform the method of any of claims 1-8.

11. A non-transitory computer readable storage medium storing computer instructions which, when executed by a computer, cause the computer to perform the method of any of claims 1-8.

12. A battery stability evaluation system, comprising: a charging power supply and the battery stability evaluation apparatus according to claim 10; wherein:

the charging power supply is used for charging the battery to be tested;

the battery stability evaluation device is used for calculating the electric quantity loss value of the battery to be tested, and evaluating the stability of the battery to be tested according to the electric quantity loss value.