CN115808636A

CN115808636A - Battery capacity loss test method and device, computer equipment and storage medium

Info

Publication number: CN115808636A
Application number: CN202211137214.4A
Authority: CN
Inventors: 冯婷; 张继君; 王少飞; 魏奕民
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2022-09-19
Filing date: 2022-09-19
Publication date: 2023-03-17

Abstract

The application relates to a method and a device for testing battery capacity loss, computer equipment and a storage medium. The method comprises the following steps: the method comprises the steps of carrying out constant voltage charging on a battery to be tested, obtaining leakage current of a target electrode of the battery to be tested, carrying out constant voltage charging according to preset test duration, wherein the target electrode comprises an electrode with working voltage in a platform area, and determining a capacity loss value of the target electrode of the battery to be tested based on the leakage current of the target electrode and the preset test duration. By adopting the method, the capacity loss value of the target electrode of the battery to be tested can be measured through simple test operation and short-time electrical property test, a positive and negative electrode secondary reaction model of the battery does not need to be established in a simulation manner, and the long-term electrical property test of the battery to be tested is also not needed, so that the test efficiency of the battery capacity attenuation is greatly improved.

Description

Battery capacity loss test method and device, computer equipment and storage medium

Technical Field

The present application relates to the field of battery detection technologies, and in particular, to a method and an apparatus for testing battery capacity loss, a computer device, a storage medium, and a computer program product.

Background

In the battery industry, battery capacity is often used as an index for evaluating battery life. However, the battery has a problem of capacity continuous decay in the use stage. Therefore, it becomes important to study and analyze the mechanism of the capacity fade of the battery. Research shows that the life attenuation of the lithium ion battery is closely related to the internal chemical/electrochemical side reaction of the lithium ion, and the loss of the active material of the positive electrode of the battery and the loss of the active material of the negative electrode of the battery are just one of the reasons of the life attenuation of the battery.

At present, the method for evaluating the loss of the anode and cathode materials of the battery mainly comprises the following steps: and (3) simulating and establishing a battery anode and cathode side reaction model, and calculating the lithium embedding amount change of the anode and the cathode caused by side reaction in the storage process of the battery through the model, or detecting the loss of the anode and the cathode materials through long-term electrical property test.

However, in the above method, a large number of experimental tests are required to obtain the key parameters, which is time-consuming, tedious in operation process and low in test efficiency.

Disclosure of Invention

In view of the above, it is necessary to provide a battery capacity loss testing method, apparatus, computer device, computer readable storage medium and computer program product capable of improving testing efficiency.

In a first aspect, the present application provides a method for testing capacity loss of a battery. The method comprises the following steps:

performing constant voltage charging on a battery to be tested, and acquiring leakage current of a target electrode of the battery to be tested, wherein the target electrode is subjected to constant voltage charging according to preset test duration and comprises an electrode with working voltage in a non-platform area;

and determining the capacity loss value of the target electrode of the battery to be tested based on the leakage current of the target electrode and the preset test duration.

According to the technical scheme, the battery to be tested is charged at constant voltage, the leakage current of the target electrode of the battery to be tested after the testing time is long is obtained, and the capacity loss value of the target electrode is determined according to the leakage current of the target electrode and the preset testing time. In the whole process, the characteristic of high charging efficiency of constant voltage charging is utilized, the capacity loss test time is shortened, a simulation establishment of a battery anode and cathode side reaction model is not needed, a long-term electrical property test on the battery to be tested is also not needed, the capacity loss value of the target electrode of the battery to be tested is measured through simple test operation and short-time electrical property test, and the test efficiency of battery capacity attenuation is greatly improved.

In some embodiments, if the battery under test further has an electrode with an operating voltage in the plateau region, the method further comprises:

the method comprises the steps of sequentially carrying out complete discharge, charge and complete discharge on a battery to be tested which is subjected to constant voltage charge according to a preset test duration to obtain the total capacity loss values of a positive electrode and a negative electrode;

and obtaining the capacity loss value of the electrode with the working voltage of the battery to be tested in the platform area according to the total capacity loss values of the anode and the cathode and the capacity loss value of the target electrode.

According to the technical scheme, the battery to be tested is completely discharged, charged and completely discharged again in sequence, the capacity loss of the battery in the charging and storing process can be simulated, the total positive and negative capacity loss values are obtained, further, the capacity loss value of the electrode with the working voltage in the platform area is obtained according to the total positive and negative capacity loss values and the capacity loss value of the target electrode, the problem that the leakage current of the electrode at one end cannot be measured and the capacity loss value of the electrode cannot be evaluated is solved, the positive capacity loss value and the negative capacity loss value are effectively distinguished, and the battery with longer service life is favorably designed.

In some embodiments, the steps of sequentially performing full discharge, charge and full discharge on a battery to be tested which is subjected to constant voltage charge according to a preset test duration include:

completely discharging the battery to be tested which is subjected to constant voltage charging according to a preset test duration, and recording a first complete discharge capacity;

charging the battery to be tested by using a preset SOC test value, wherein the preset SOC test value is obtained based on the current SOC value of the battery to be tested;

fully discharging the battery to be tested which is charged according to the preset test duration again, and recording a second full discharge capacity;

and obtaining the total capacity loss value of the anode and the cathode according to the first complete discharge capacity and the second complete discharge capacity.

According to the technical scheme, the battery to be tested is charged by the preset SOC test value, and one-time complete discharge is respectively carried out before and after the battery to be tested is charged by the test SOC value, so that the real capacity loss condition of the battery to be tested can be accurately simulated, and the total discharge capacity of the battery to be tested before and after the battery to be tested is charged can accurately represent the total capacity loss value of the anode and the cathode.

In some embodiments, before the constant voltage charging of the battery under test, the method further comprises:

acquiring battery state data of a battery to be tested;

determining a target electrode of the battery to be tested according to battery state data, wherein the battery state data comprises a mapping relation between SOC and OCV (Open Circuit Voltage) and a current SOC value.

In the technical scheme of the embodiment of the application, the state of the electrode of the battery to be tested can be simply and quickly judged through the state number of the battery, such as the mapping relation of SOC and OCV and the current SOC value, and then the target electrode is determined.

In some embodiments, if it is determined that the target electrode of the battery under test includes a positive electrode and a negative electrode according to the battery state data, before performing the constant voltage charging on the battery under test, the method further includes:

transmitting a three-electrode battery assembly message;

when the three-electrode battery is assembled, acquiring an SOC value of the three-electrode battery, and adjusting the SOC value of the three-electrode battery to a preset SOC test value, wherein the preset SOC test value is obtained based on the current SOC value of the battery to be tested;

carry out constant voltage charging to the battery that awaits measuring, obtain according to predetermineeing test duration and carry out the leakage current of the target electrode of the battery that awaits measuring that constant voltage charges and include:

reading an open-circuit voltage value corresponding to a preset SOC test value;

and carrying out constant voltage charging on the three-electrode battery according to the open-circuit voltage value, and obtaining the positive leakage current and the negative leakage current of the three-electrode battery which is subjected to constant voltage charging according to the preset test duration.

According to the technical scheme, the three-electrode battery is assembled, constant-voltage charging is carried out on the three-electrode battery, positive leakage current and negative leakage current can be measured respectively, and then the positive capacity loss value and the negative capacity loss value can be conveniently obtained through evaluation according to the positive leakage current and the negative leakage current.

In some embodiments, determining the capacity loss value of the target electrode of the battery under test based on the leakage current and the preset test duration comprises:

and performing integral operation on the leakage current of the target electrode under the preset test duration to obtain the capacity loss value of the target electrode of the battery to be tested.

According to the technical scheme of the embodiment of the application, the capacity loss value of the target electrode of the battery to be tested can be quickly and accurately obtained by performing integral operation on the leakage current of the target electrode under the preset testing duration.

In some embodiments, performing constant voltage charging on the battery to be tested if the battery to be tested also has an electrode with a working voltage in the platform region, and obtaining the leakage current of the target electrode of the battery to be tested, which is subjected to constant voltage charging according to the preset test duration, includes:

carrying out constant voltage charging on the battery to be tested for multiple times according to the preset test times, and recording the leakage current of the target electrode of the battery to be tested after constant voltage charging is carried out according to the preset test duration each time;

determining a capacity loss value of a target electrode of the battery to be tested based on the leakage current and the preset test duration comprises:

and performing integral operation on the leakage current of the target electrode of the battery to be tested under different preset test durations, and determining the capacity loss value of the target electrode of the battery to be tested.

According to the technical scheme, the capacity loss of the battery in the actual use and storage process can be simulated more truly by carrying out constant voltage charging on the battery to be tested for multiple times, the leakage currents of the target electrode under the condition of multiple preset test durations are obtained, and then the accuracy of the more accurate capacity loss value of the target electrode of the battery to be tested can be obtained by carrying out integral operation on the leakage currents of the target electrode of the battery to be tested under the condition of different preset test durations.

In a second aspect, the present application further provides a battery capacity loss testing device. The device comprises:

and the data acquisition module is used for carrying out constant voltage charging on the battery to be tested and acquiring the leakage current of a target electrode of the battery to be tested, which carries out constant voltage charging according to the preset test duration, wherein the target electrode comprises an electrode of which the working voltage is in a non-platform area.

And the capacity loss value determining module is used for determining the capacity loss value of the target electrode of the battery to be tested based on the leakage current of the target electrode and the preset testing time.

In a third aspect, the present application also provides a computer device. The computer device comprises a memory and a processor, wherein the memory stores a computer program, and the processor realizes the steps of the battery capacity loss testing method when executing the computer program.

In a fourth aspect, the present application further provides a computer-readable storage medium. The computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the above-mentioned battery capacity loss testing method.

In a fifth aspect, the present application further provides a computer program product. The computer program product comprises a computer program which, when executed by a processor, implements the steps of the above-described battery capacity loss testing method.

The foregoing description is only an overview of the technical solutions of the present application, and the present application can be implemented according to the content of the description in order to make the technical means of the present application more clearly understood, and the following detailed description of the present application is given in order to make the above and other objects, features, and advantages of the present application more clearly understandable.

Drawings

FIG. 1 is a diagram of an exemplary application of a method for testing capacity loss of a battery in accordance with certain embodiments;

FIG. 2 is a schematic flow chart of a battery capacity loss test method in some embodiments;

FIG. 3 is a schematic flow chart of a method for testing capacity loss of a battery in other embodiments;

FIG. 4 is a schematic flow chart of the step of obtaining total positive and negative capacitance loss values in some embodiments;

FIG. 5 is a schematic flow chart of a method for testing capacity loss of a battery according to some embodiments;

FIG. 6 is a schematic flow chart of a method for testing capacity loss of a battery in further embodiments;

FIG. 7 is a block diagram of a battery capacity loss testing apparatus in some embodiments;

FIG. 8 is a block diagram of a battery capacity loss testing apparatus according to further embodiments;

FIG. 9 is a diagram of the internal structure of a computer device in some embodiments.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are merely used to more clearly illustrate the technical solutions of the present application, and therefore are only examples, and the protection scope of the present application is not limited thereby.

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 "including" and "having," and any variations thereof, in the description and claims of this application and the description of the above figures are intended to cover non-exclusive inclusions.

In the description of the embodiments of the present application, the technical terms "first", "second", and the like are used only for distinguishing different objects, and are not to be construed as indicating or implying relative importance or implicitly indicating the number, specific order, or primary-secondary relationship of the technical features indicated. In the description of the embodiments of the present application, "a plurality" means two or more unless specifically defined otherwise.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase 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. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

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

At present, the application of the battery is more and more extensive from the development of market situation. The battery is not only applied to energy storage power supply systems such as hydraulic power, firepower, wind power and solar power stations, but also widely applied to electric vehicles such as electric bicycles, electric motorcycles, electric automobiles and the like, and a plurality of fields such as military equipment and aerospace. With the continuous expansion of the application field of the power battery, the market demand is also continuously expanding.

With the increasing requirements on energy conservation, emission reduction and environmental protection, the new energy automobile industry is developed vigorously in recent years. The power battery is one of the core components of the electric automobile, and the performance indexes of the power battery, such as battery capacity, directly influence the overall performance of the electric automobile. In order to ensure the normal running and safety performance of the electric automobile, after the electric automobile runs for a certain mileage, the battery needs to be replaced, and the importance of the service life evaluation of the battery on the electric automobile can be seen.

However, the problem of continuous capacity fading of the battery occurs during the use stage, and it becomes important to study and analyze the mechanism of the capacity fading of the battery. Research shows that the life attenuation of lithium ion batteries (hereinafter referred to as lithium batteries) commonly used in electric vehicles is closely related to the internal chemical/electrochemical side reactions of lithium ions, and the loss of the active material of the positive electrode of the battery and the loss of the active material of the negative electrode of the battery are just one of the main causes of the life attenuation of the battery.

The conventional method for evaluating the battery life decay mainly comprises the following steps: and (3) simulating and establishing a battery anode and cathode side reaction model, and calculating the lithium embedding amount change of the anode and the cathode caused by side reaction in the storage process of the battery through the model, or detecting the loss of the anode and the cathode materials through long-term electrical property test. However, in the above methods, from the viewpoint of the evaluation of the loss of the active material of the entire battery, the loss of the positive electrode active material and the loss of the negative electrode active material are not distinguished, and the above methods require a large number of experimental tests to obtain key parameters, which takes a long time and is complicated in operation process, and the test efficiency is low.

In order to improve the efficiency of the battery life decay test, the applicant researches and discovers that the leakage currents of the anode and the cathode of the battery can represent the rates of the anode and the cathode side reactions, if the degrees of the performance degradation of the battery caused by the anode and the cathode side reactions respectively can be effectively distinguished, the rapid evaluation of the anode and the cathode materials is realized, and the design of the battery with longer service life is facilitated. The applicant also noticed that, compared to the conventional constant current charging method, the constant voltage charging method has the advantages of short charging time, low energy consumption and high charging efficiency.

Based on the above consideration, the applicant has proposed a scheme for evaluating the capacity loss of the electrode based on the constant voltage charging test leakage current, that is, performing constant voltage charging on the battery to be tested to obtain the leakage current of the target electrode of the battery to be tested performing constant voltage charging according to the preset test duration, and then determining the capacity loss value of the target electrode of the battery to be tested based on the leakage current of the target electrode and the preset test duration. In the whole testing process, a battery anode and cathode side reaction model does not need to be established in a simulation mode, the long-term electrical property test of the battery to be tested is also not needed, the operation is simpler, the capacity loss value of the battery electrode to be tested can be measured through the short-time electrical property test, and the testing efficiency of the battery capacity attenuation is greatly improved.

It can be understood that the battery capacity loss test method of the present application is not only applicable to lithium batteries, but also applicable to other batteries with positive electrodes made of deintercalating materials, such as sodium ion batteries, potassium ion batteries, and the like; more specifically, it is applicable to batteries including, but not limited to, lithium nickel cobalt manganese oxide ternary materials, lithium nickel cobalt aluminum ternary materials, lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium iron phosphate, lithium iron manganese phosphate, lithium manganese rich manganese based materials, and the like as the positive electrode.

The battery capacity loss testing method provided by the embodiment of the application can be applied to the application environment shown in fig. 1. The controller 102 performs test management and control on the battery capacity loss testing device, and evaluates the side reaction capacity loss of the battery under test in the battery capacity loss testing device 104. Specifically, the tester may send a test instruction to the controller 102, the controller 102 responds to the test instruction, performs constant voltage charging on the battery to be tested, obtains a leakage current of a target electrode of the battery to be tested, which performs constant voltage charging in a preset test duration, after performing constant voltage charging in the preset test duration, and then determines a capacity loss value of the target electrode of the battery to be tested based on the leakage current of the target electrode and the preset test duration, where the target electrode includes an electrode whose working voltage is in a non-platform area.

In one embodiment, as shown in fig. 2, a method for testing battery capacity loss is provided, which is illustrated by applying the method to the controller 102 in fig. 1, and includes the following steps:

and 200, performing constant voltage charging on the battery to be tested, and acquiring the leakage current of a target electrode of the battery to be tested, which is subjected to constant voltage charging according to the preset test duration, wherein the target electrode comprises an electrode of which the working voltage is in a non-platform area.

The battery to be tested may be a lithium battery. The leakage current is a current value when the current change is in a more stable state, that is, a current when the current change is in the more stable state is determined as the leakage current. The leakage current of the target electrode may be indicative of the rate of side reactions at the electrode. In this embodiment, the target electrode includes an electrode whose working voltage is in a non-platform region, that is, may include a positive electrode and a negative electrode, may also include only the positive electrode, or include only the negative electrode, and may be specifically determined according to a battery state of the battery to be tested. Compared with constant-current charging, constant-voltage charging has the characteristics of short charging time and high charging efficiency, so that in the embodiment, the constant-voltage charging can be performed on the battery to be tested to complete the rapid charging of the battery to be tested. Specifically, the capacity loss testing device may be a charge and discharge meter, as shown in fig. 1, the capacity loss testing device includes two voltmeters, two ammeters (ammeter 1 and ammeter 2), and a battery to be tested, and may be configured to read an open-circuit voltage value of the battery to be tested, which is recorded as OCV1, perform constant-voltage charging on the battery through the OCV1 by using a constant-voltage source, and at this time, the ammeter 1 outputs leakage currents of target electrodes at different times. After charging is completed, the battery to be tested is placed for a preset test time period, such as 10 days, and then the leakage current of the test time period, such as 1-10 days, is recorded.

And step 400, determining a capacity loss value of the target electrode of the battery to be tested based on the leakage current of the target electrode and the preset test duration.

In the present embodiment, the capacity loss value refers to the amount of capacity loss generated during the storage and use of the battery. The capacity loss value includes a side reaction capacity loss value, which is a capacity loss amount caused by a side reaction occurring inside the battery, and a capacity loss value caused by a generated by-product. After the target leakage current is obtained, a capacity loss value of the target electrode of the battery to be tested may be determined based on the target electrode leakage current and a preset test duration. Specifically, if the precision of the capacitance loss testing device is high enough and the value of the leakage current measured by the ammeter is accurate enough, the product of the leakage current of the target electrode and the preset testing time period may be obtained to determine the capacitance loss value of the target electrode. If the precision of the capacity loss testing device is at a normal level, the leakage current of the target electrode can be integrated for a preset testing duration, and the integration result is determined as the capacity loss value of the target electrode.

As shown in fig. 3, in some embodiments, step 400 includes: and step 420, performing integral operation on the leakage current of the target electrode under the preset test duration to obtain the capacity loss value of the target electrode of the battery to be tested.

In specific implementation, the leakage current of the target electrode under the preset test duration may be obtained by performing an integral operation according to the leakage current and the capacity loss value of the target electrode. If the leakage current of the target electrode includes an anode leakage current and a cathode leakage current, integral operation may be performed on the anode leakage current value and the cathode leakage current value respectively under a preset test duration to obtain an anode capacity loss value ^ I _ leak _ neg. (t) dt and a cathode capacity loss value ^ I _ leak _ neg. (t) dt under the test duration.

As shown in fig. 3, in some embodiments, before the constant voltage charging of the battery under test, the method further includes: step 100, obtaining battery state data of a battery to be tested, and determining a target electrode of the battery to be tested according to the battery state data, wherein the battery state data comprises a mapping relation between SOC and OCV and a current SOC value.

The battery State data includes a mapping relationship of SOC and OCV, and a current SOC value, SOH (State of Health), SOF (State of Function), or other battery State parameters. The mapping relationship between SOC and OCV may be an SOC-OCV curve or a mapping relationship table between SOC and OCV. In this embodiment, the mapping relationship between SOC and OCV is exemplified by a discharge SOC-OCV curve of the positive electrode and a discharge SOC-OCV curve of the negative electrode of the battery to be measured. The discharging SOC-OCV curve may be obtained by obtaining a current SOC value of the battery to be measured, and further obtaining SOC-OCV curves of the positive electrode and the negative electrode of the battery to be measured, where each SOC value has a corresponding OCV value in the SOC-OCV curves.

Specifically, the SOC/OCV curves are defined as a positive electrode discharge SOC-OCV curve and a negative electrode discharge SOC-OCV curveFor example, the discharge SOC-OCV curve reflects the state of the electrodes, and is the superposition of the state changes of the positive and negative electrodes. In the whole discharging process, the voltage curve of the lithium battery can be divided into the following 3 stages: 1. the terminal voltage of the battery rapidly drops in the initial stage, and the voltage drops more rapidly the larger the discharge rate is. 2. The battery voltage enters a period of slow change, which can be called a plateau region of the battery, and the smaller the discharge rate, the longer the plateau region lasts, the higher the plateau voltage, and the slower the voltage drop. 3. When the battery charge approaches the end of discharge, the battery load voltage begins to drop sharply until the discharge cutoff voltage is reached. In this embodiment, the SOC-OCV curve can be divided into a plateau region, a non-plateau region and a transition region according to the slope (which can be regarded as a voltage drop) of each curve segment in the SOC-OCV curve. Specifically, if the slope of a certain curve segment of the SOC-OCV curve

If the slope of a certain curve segment of the SOC-OCV curve is not 0 and has an obvious slope, the curve segment is defined as a non-plateau region (a slope region) of the SOC-OCV curve, and the rest curve segments are defined as transition regions.

In specific implementation, according to the battery state data, determining the target electrode of the battery to be tested may be: reading a current SOC value of a battery to be measured, then, judging whether a voltage corresponding to the current SOC value is in a non-platform area of a negative SOC-OCV curve and a non-platform area of a negative SOC-OCV curve, if the voltage corresponding to the current SOC value is in the non-platform area of the positive SOC-OCV curve and is in the platform area of the negative SOC-OCV curve, determining that a target electrode is a positive electrode, if the voltage corresponding to the current SOC value is in the platform area of the positive SOC-OCV curve and is in the non-platform area of the negative SOC-OCV curve, determining that the target electrode is a negative electrode, and if the voltage corresponding to the current SOC value is in the platform area of the positive SOC-OCV curve and is in the platform area of the negative SOC-OCV curve, determining that the target electrode comprises the positive electrode and the negative electrode.

In the technical scheme of the embodiment of the application, the target electrode can be simply and quickly determined through the current SOC value of the battery to be tested and the mapping relation between the SOC and the OCV.

As shown in fig. 3, in some embodiments, if the battery to be tested further has an electrode with an operating voltage in the platform region, the method further includes:

and step 600, performing complete discharge, charge and complete discharge on the battery to be tested which is subjected to constant voltage charge according to the preset test duration in sequence to obtain the total capacity loss value of the anode and the cathode.

And 800, obtaining the capacity loss value of the electrode with the working voltage of the battery to be tested in the platform area according to the total capacity loss values of the anode and the cathode and the capacity loss value of the target electrode.

The total capacity loss value of the anode and the cathode refers to the sum of the capacity loss value of the anode and the capacity loss value of the cathode. In practical applications, if the voltage enters a stage of slow change, the voltage change of the electrode is very small, so that the leakage current of the electrode cannot be effectively obtained through constant voltage charging. Therefore, the first capacity loss testing method is provided for testing the battery to be tested under the condition that the target electrode comprises the positive electrode and the negative electrode; and aiming at the condition that the target electrode comprises a positive electrode or a negative electrode, a second capacity loss testing method is provided for testing the battery to be tested. Specifically, the first capacity loss testing method is a testing method in which a battery to be tested is assembled into a three-electrode battery, the positive electrode leakage current value and the negative electrode leakage current value of the three-electrode battery are tested by a constant voltage charging method, and then the capacity loss amounts of the positive electrode and the negative electrode are obtained by evaluating the positive electrode leakage current value and the negative electrode leakage current value. The second capacity loss test method is a test method for testing the leakage current value of the battery in a constant voltage charging mode and obtaining the capacity loss values of the anode and the cathode of the battery by performing charging and discharging tests on the battery to be tested.

In this embodiment, for the target electrode including the positive electrode or the negative electrode, the second capacity loss testing method is adopted to perform the capacity loss test on the battery to be tested. Specifically, after the capacity loss value of the target electrode is determined according to the leakage current and the preset test duration of the target electrode, the battery to be tested, which is charged at constant voltage according to the preset test duration, may be sequentially subjected to complete discharge, charge and complete discharge, and the charge and discharge test is performed on the battery to be tested, so as to obtain the total capacity loss values of the positive and negative electrodes of the battery, that is, the positive and negative capacity loss values, and further subtract the capacity loss value of the target electrode from the total capacity loss value caused by the positive and negative side reactions, so as to obtain the capacity loss value of the other electrode. For example, if the target electrode is a positive electrode, the capacity loss value of the positive electrode is denoted as Q _ loss _ pos. (t), and the total capacity loss value of the positive electrode and the negative electrode is denoted as Q _ loss _ total (t), the capacity loss value of the negative electrode is denoted as Q _ loss _ neg. (t) = Q _ loss _ total (t) -Q _ loss _ pos. (t).

For example, if the target electrode is determined to include the positive electrode or the negative electrode according to the SOC-OCV curves of the positive electrode and the negative electrode, the process of testing the battery to be tested may be: referring to fig. 1, the positive electrode and the negative electrode of the capacity loss testing device are connected with the positive electrode and the negative electrode of the battery to be tested, the switch 1 is disconnected, the open-circuit voltage value of the battery to be tested is read through the voltmeter and recorded as OCV1, then the constant voltage source charges the battery to be tested in a constant voltage mode through the read OCV1, at the moment, the negative electrode voltage does not change or changes very little, only the ammeter 1 outputs the positive electrode leakage current at different time along with the time lapse, in the process, the positive electrode leakage current when the current change state is balanced and stable is recorded as I _ leak _ pos. _0, and the positive electrode side reaction rate is represented. And then, the battery to be tested after constant voltage charging is completed is completely discharged, charged and completely discharged again in sequence, the side reaction capacity loss process of the battery in the charging and storing (storing) process is simulated, the positive electrode leakage current of the battery to be tested in a non-platform area for a corresponding preset test time period such as 3 days is recorded, and the total capacity loss value Q _ loss _ total (t) of the positive electrode and the negative electrode is obtained. Then, an anode capacity loss value Q _ loss _ pos (t) is obtained from the anode leakage current and a preset test duration, and the cathode capacity loss value Q _ loss _ neg (t) = Q _ loss _ total (t) -Q _ loss _ pos (t). It can be understood that if the anode of the battery is determined to be Ping Taiou and the cathode is determined to be in a non-platform area according to the SOC-OCV curves of the anode and the cathode, the cathode leakage current is measured in a constant voltage charging manner, and then the cathode capacity loss value is obtained according to the cathode leakage current and the preset test duration. And then, subtracting the negative electrode capacity loss value from the positive electrode total capacity loss value to obtain a positive electrode capacity loss value.

According to the technical scheme of the embodiment of the application, the battery to be tested is completely discharged, charged and completely discharged again in sequence, so that the capacity loss of the battery in the storage process can be simulated, the total positive and negative capacity loss values can be obtained, further, the capacity loss value of the electrode with the working voltage in the platform area can be obtained according to the total positive and negative capacity loss values and the capacity loss value of the target electrode, the problem that the leakage current of the electrode at one end cannot be measured and the capacity loss value of the electrode cannot be evaluated is solved, the positive capacity loss value and the negative capacity loss value are effectively distinguished, and the battery with longer service life can be designed.

As shown in fig. 4, in some embodiments, step 600 comprises:

and step 620, completely discharging the battery to be tested which is subjected to constant voltage charging according to the preset test duration, and recording the first complete discharge capacity.

And step 640, charging the battery to be tested by using a preset SOC test value, wherein the preset SOC test value is obtained based on the current SOC value of the battery to be tested.

And 660, completely discharging the battery to be tested which is charged according to the preset test duration again, and recording a second complete discharge capacity.

And step 680, acquiring a total capacity loss value of the anode and the cathode according to the first complete discharge capacity and the second complete discharge capacity.

Accepting the above embodiment, after the constant voltage charging is completed, the process of complete discharging, charging and complete discharging is carried out in sequence on the battery to be tested which carries out the constant voltage charging according to the preset test duration: the battery to be tested can be completely discharged firstly, and the complete discharge capacity of the battery to be tested in a complete discharge state is recorded to obtain a first complete discharge capacity which is marked as Q1. And then, charging the battery to be tested after complete discharge according to a preset test time length and charging the battery to be tested after complete discharge by using a preset SOC storage value, wherein the SOC storage value can be the current actual SOC value of the battery to be tested before testing, simulating a capacity loss process of the battery in a charging and storing process, recording the leakage current of the target electrode of the battery to be tested after charging, and establishing a corresponding relation between the test time length and the leakage current of the target electrode. And then, completely discharging the battery to be measured again, recording the discharge capacity of the battery to be measured in the completely discharged state again, and recording the discharge capacity as a second discharge capacity Q2, and then obtaining the total loss value Q _ loss _ total (t) = Q1-Q2 of the positive and negative electrodes according to the first complete discharge capacity Q1 and the second complete discharge capacity Q2. It can be understood that the test time for charging the fully discharged battery to be tested by using the preset SOC storage value may be equal to or different from the preset time for constant voltage charging, which may be determined according to the situation.

As shown in fig. 5, in some embodiments, if it is determined that the target electrode of the battery to be tested includes a positive electrode and a negative electrode according to the battery state data, before performing the constant voltage charging on the battery to be tested, the method further includes:

step 120, a three-electrode battery assembly message is sent.

And 140, when the three-electrode battery is assembled, acquiring the SOC value of the three-electrode battery, and adjusting the SOC value of the three-electrode battery to a preset SOC test value, wherein the preset SOC test value is obtained based on the current SOC value of the battery to be tested.

Step 200 comprises: and step 220, reading an open-circuit voltage value corresponding to the preset SOC test value, performing constant-voltage charging on the three-electrode battery according to the open-circuit voltage value, and acquiring the positive leakage current and the negative leakage current of the three-electrode battery performing constant-voltage charging according to the preset test duration.

Step 400 comprises: and step 420, respectively performing integral operation on the positive leakage current and the negative leakage current of the battery to be tested under the preset test duration, and determining the capacity loss value of the positive electrode and the negative capacity loss value of the battery to be tested.

The three-electrode cell is designed to eliminate the large error of electrode potential caused by polarization current, and comprises a working electrode, a reference electrode and an auxiliary electrode (also called a counter electrode), wherein the reference electrode for stabilizing the working electrode is introduced on the basis of a common two-electrode system (the working electrode and the counter electrode).

The present embodiment is described with respect to a capacity loss test performed on a battery to be tested by a first capacity loss test method. Specifically, the capacity loss testing device may be a charge-discharge meter including two voltmeters, two current meters, and a battery to be tested. With reference to fig. 1, the capacity loss test performed on the battery to be tested by the first capacity loss test method may be: and sending a three-electrode battery assembly message, and configuring and assembling the three-electrode battery by a tester based on the battery to be tested. It is understood that the three-electrode battery can be assembled by a machine or by a computer by constructing a three-electrode simulation model, depending on the actual situation. And then, standing the three-electrode battery for a certain time, such as 20 days, and until the battery is depolarized in a sufficient area, so as to reduce the polarization effect of the three-electrode battery. And then, connecting the anode and the cathode of the capacity loss testing device with the anode and the cathode of the battery respectively, connecting the reference electrode with the Chi Canbi electrode, closing the switch 1, and feeding back a message of the completion of the assembly of the three-electrode battery to the controller. Then, the controller obtains an SOC value of the three-electrode battery, and adjusts the SOC value of the battery to be tested to a preset SOC test value through the charging and discharging device, where the test SOC value may be an actual SOC value of the battery to be tested currently or a test value determined based on the actual SOC value, a battery open-circuit voltage value corresponding to the preset SOC test value is read through the voltmeter and is recorded as OCV1, the battery is charged at constant voltage by the constant voltage source through OCV1, at this time, the ammeter 1 outputs an anode leakage current value at different times and is recorded as I _ leak _ pos, the anode leakage current value may represent an anode-to-cathode reaction rate, the ammeter 2 outputs a cathode leakage current value at different times and is recorded as I _ leak _ neg, and the cathode leakage current value may represent a cathode-to-cathode reaction rate. Then, the positive leakage current and the negative leakage current for a preset test time period, such as 1-10 days, are obtained. Further, integral operation is respectively performed on the anode leakage current value and the cathode leakage current value under a preset test duration to obtain the anode capacity loss value ^ I _ leak _ neg. (t) dt and the cathode capacity loss value ^ I _ leak _ neg. (t) dt under the test duration.

According to the technical scheme, the three-electrode battery is assembled, constant-voltage charging is carried out on the three-electrode battery, leakage currents of the positive electrode and the negative electrode under the testing duration are rapidly measured, integration is carried out on the leakage currents of the positive electrode and the negative electrode under the testing duration, a positive electrode capacity loss value and a negative electrode capacity loss value are respectively obtained, the operation is simple, the positive electrode capacity loss value and the negative electrode capacity loss value are measured through short-time electrical property testing, and the testing efficiency is improved.

As shown in fig. 5, in some embodiments, if the battery to be tested has an electrode with an operating voltage in the platform region, step 200 includes:

and 240, carrying out constant voltage charging on the battery to be tested for multiple times according to the preset test times, and recording the leakage current of the target electrode of the battery to be tested after constant voltage charging is carried out according to the preset test duration each time.

Step 400 comprises: step 440, performing an integral operation on the leakage current of the target electrode of the battery to be tested under different preset test durations, and determining a capacity loss value of the target electrode of the battery to be tested.

The preset test times can be determined according to the precision of the test equipment, and are generally not less than 3 times. The present embodiment is described with respect to a test performed on a battery to be tested by using the second capacity loss test method. In specific implementation, in order to ensure the accuracy of the capacity loss value, after the preset test times are determined, the open-circuit voltage value of the battery to be tested is read, the battery to be tested is subjected to constant-voltage charging according to the preset test duration by using the open-circuit voltage value, after the battery is charged to the preset test duration, the open-circuit voltage value of the battery to be tested is read again, and the battery to be tested is subjected to constant-voltage charging according to the preset test duration by using the open-circuit voltage value. And repeating the steps until the test times reach the preset test times. In this way, the leakage currents of the target electrode under a plurality of test durations are obtained, and then the leakage currents of the target electrode under the plurality of test durations are integrated to obtain the capacity loss value of the target electrode. For example, if the leakage currents of the target electrodes are the anode leakage current stable value I _ leak _ pos _ t, and the preset test durations are t1, t2, and t3, a relationship curve I _ leak _ pos. _ t-t of I _ leak _ pos. _ t and t may be constructed according to the preset test durations and the preset test durations, and an area of the curve I _ leak _ pos. _ t-t is integrated to obtain an anode capacity loss value, which is denoted as Q _ loss _ pos. (t) = I _ leak _ pos. _ tdt.

To make the description of the battery capacity loss test method provided in the present application clearer, the following description is made with reference to fig. 6 and an embodiment, which includes the following steps:

step 1: and acquiring a discharging SOC-OCV curve of the anode and a discharging SOC-OCV curve of the cathode of the battery to be tested.

Step 2: if the working voltages of the anode and the cathode of the battery to be detected are both in a non-platform area (slope area) according to the slopes of the discharging SOC-OCV curves of the anode and the cathode, determining that the capacity loss detection method is a first capacity loss detection method, and entering step 3-1; if the working voltage of one anode (the anode or the cathode) of the battery to be detected is judged to be in the platform area, determining the capacity loss detection method as a second capacity loss detection method, and entering the step 3-2;

step 3-1-1: a three-electrode assembly message is sent.

Step 3-1-2: and when the three-electrode battery is assembled, acquiring the SOC value of the three-electrode battery, and adjusting the SOC value of the three-electrode battery to a preset SOC test value.

Step 3-1-3: and reading an open-circuit voltage value corresponding to the preset SOC test value.

Step 3-1-4: and carrying out constant voltage charging on the three-electrode battery by using the open-circuit voltage value to obtain the anode leakage current and the cathode leakage current at different time.

Step 3-1-5: and acquiring the anode leakage current and the cathode leakage current under the preset test duration, and respectively carrying out integral operation on the anode leakage current and the cathode leakage current under the preset test duration to obtain an anode capacity loss value and a cathode capacity loss value of the battery to be tested.

Step 3-2: and reading the open-circuit voltage value of the battery to be tested.

And 3-2-2, performing constant voltage charging on the battery to be tested for a period of time by using the open-circuit voltage value according to the preset test duration, and obtaining the leakage current of the target electrode at different times.

And 3-2-3, completely discharging the battery to be tested which is subjected to constant voltage charging according to the preset test duration, and recording the first complete discharge capacity.

And 3-2-4, charging the battery to be tested by using a preset SOC test value.

And 3-2-5, carrying out constant voltage charging on the battery to be tested after charging according to the preset test time according to the preset test times, and recording the leakage current of the target electrode of the battery to be tested, which is subjected to constant voltage charging according to the preset test time each time, so as to obtain the leakage currents of the target electrode under different test times.

And 3-2-6, completely discharging the battery to be tested after constant voltage charging for multiple times again, and recording a second complete discharge capacity.

And 3-2-7, obtaining the total capacity loss value of the anode and the cathode according to the first complete discharge capacity and the second complete discharge capacity.

And 3-2-8, performing integral operation on the leakage current of the target electrode under a plurality of preset test durations to obtain the capacity loss value of the target electrode of the battery to be tested.

And 3-2-9, obtaining the capacity loss value of the electrode with the working voltage of the battery to be tested in the platform area according to the capacity loss value of the target electrode of the battery to be tested and the total positive and negative capacity loss values.

It should be understood that, although the steps in the flowcharts related to the embodiments as described above are sequentially displayed as indicated by arrows, the steps are not necessarily performed sequentially as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least a part of the steps in the flowcharts related to the embodiments described above may include multiple steps or multiple stages, which are not necessarily performed at the same time, but may be performed at different times, and the execution order of the steps or stages is not necessarily sequential, but may be rotated or alternated with other steps or at least a part of the steps or stages in other steps.

Based on the same inventive concept, the embodiment of the application also provides a battery capacity loss testing device for realizing the battery capacity loss testing method. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the method, so that specific limitations in one or more embodiments of the battery capacity loss testing device provided below can be referred to the limitations in the battery capacity loss testing method above, and details are not repeated herein.

In one embodiment, as shown in fig. 7, there is provided a battery capacity loss testing apparatus including: a data acquisition module 710 and a capacity loss value method determination module 720, wherein:

the data obtaining module 710 is configured to perform constant voltage charging on the battery to be tested, and obtain a leakage current of a target electrode of the battery to be tested, where the target electrode performs constant voltage charging according to a preset test duration, and the target electrode includes an electrode whose working voltage is in a non-platform area.

And a capacity loss value determining module 720, configured to determine a capacity loss value of the target electrode of the battery to be tested based on the leakage current of the target electrode and a preset testing duration.

As shown in fig. 8, in some embodiments, the apparatus further includes a charge-discharge capacity testing module 730, configured to perform complete discharge, charge, and complete discharge in sequence on the battery to be tested that is subjected to constant voltage charge according to a preset testing duration, to obtain total positive and negative capacity loss values, and obtain a capacity loss value of an electrode of the battery to be tested, where the working voltage of the battery to be tested is in the platform area, according to the total positive and negative capacity loss values and the capacity loss value of the target electrode.

According to the technical scheme, the battery to be tested is completely discharged, charged and completely discharged again in sequence, the capacity loss of the battery in the storage process can be simulated, the total positive and negative capacity loss values are obtained, further, the capacity loss value of the electrode with the working voltage in the platform area is obtained according to the total positive and negative capacity loss values and the capacity loss value of the target electrode, the problem that the leakage current of the electrode at one end cannot be measured and the capacity loss value of the electrode cannot be evaluated is solved, the positive capacity loss value and the negative capacity loss value are effectively distinguished, and the battery with longer service life is favorably designed.

In some embodiments, the charge-discharge capacity test module 730 is further configured to completely discharge the battery to be tested that is subjected to constant voltage charging according to a preset test duration, record a first complete discharge capacity, charge the battery to be tested according to a preset SOC test value, where the preset SOC test value is obtained based on a current SOC value of the battery to be tested, completely discharge the battery to be tested that is charged according to the preset test duration again, record a second complete discharge capacity, and obtain a total positive-negative capacity loss value according to the first complete discharge capacity and the second complete discharge capacity.

In the technical scheme of the embodiment of the application, the charging and discharging capacity testing module charges the battery to be tested by using the preset SOC test value, and performs one-time complete discharging before and after charging the battery to be tested by using the test SOC value respectively, so that the real capacity loss condition of the battery to be tested can be simulated accurately, and the total discharge capacity of the battery to be tested before and after charging can accurately represent the total capacity loss value of the positive electrode and the negative electrode.

In some embodiments, the apparatus further includes a target electrode determining module 702, configured to obtain battery state data of the battery to be tested, determine a target electrode of the battery to be tested according to the battery state data, where the battery state data includes a mapping relationship between SOC and OCV, and a current SOC value.

In the technical scheme of the embodiment of the application, whether the electrodes of the battery to be tested are in the non-platform area can be simply and quickly judged through the state number of the battery, such as the mapping relation comprising the SOC and the OCV, so that the target electrode is determined.

In some embodiments, the apparatus further includes a three-electrode assembly module 704, configured to send a three-electrode battery assembly message, and when the three-electrode battery is assembled, obtain an SOC value of the three-electrode battery, and adjust the SOC value of the three-electrode battery to a preset SOC test value, where the preset SOC test value is obtained based on a current SOC value of the battery to be tested; the data obtaining module 710 is further configured to read an open-circuit voltage value corresponding to the preset SOC test value, perform constant voltage charging on the three-electrode battery with the open-circuit voltage value, and obtain a positive leakage current and a negative leakage current of the three-electrode battery that is subjected to constant voltage charging according to a preset test duration.

According to the technical scheme, the three-electrode battery is assembled, constant-voltage charging is carried out on the three-electrode battery, the anode leakage current and the cathode leakage current can be measured respectively, and then the anode capacity loss value and the cathode capacity loss value can be conveniently obtained through evaluation respectively according to the anode leakage current and the cathode leakage current.

In some embodiments, the capacity loss value determining module 720 is further configured to perform an integration operation on the leakage current of the target electrode under the preset test duration to obtain a capacity loss value of the target electrode of the battery to be tested.

In some embodiments, the data obtaining module 710 is further configured to perform constant voltage charging on the battery to be tested for multiple times according to the preset test times, and record a leakage current of the target electrode of the battery to be tested after performing constant voltage charging according to the preset test duration each time;

the side reaction capacity loss determining module 720 is further configured to perform an integration operation on the leakage current of the target electrode of the battery to be tested under different preset test durations, and determine a capacity loss value of the target electrode of the battery to be tested.

According to the technical scheme, the battery to be tested is subjected to constant voltage charging for multiple times, the side reaction capacity loss of the battery in the actual use and storage process can be simulated more truly, the leakage currents of the target electrode under the preset test duration are obtained, and then the accuracy of the more accurate capacity loss value of the target electrode of the battery to be tested can be obtained by performing integral operation on the leakage currents of the target electrode of the battery to be tested under different preset test durations.

The modules in the capacity loss testing device can be wholly or partially implemented by software, hardware and a combination thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.

In one embodiment, a computer device is provided, which may be a server, and the internal structure thereof may be as shown in fig. 9. The computer device includes a processor, a memory, an Input/Output interface (I/O for short), and a communication interface. The processor, the memory and the input/output interface are connected through a system bus, and the communication interface is connected to the system bus through the input/output interface. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of an operating system and computer programs in the non-volatile storage medium. The database of the computer equipment is used for storing data such as the mapping relation between the anode and cathode SOC and OCV of the battery to be tested, a preset SOC test value, a preset test duration and the like. The input/output interface of the computer device is used for exchanging information between the processor and an external device. The communication interface of the computer device is used for connecting and communicating with an external terminal through a network. The computer program is executed by a processor to implement a battery capacity loss testing method. It will be appreciated that in other embodiments the computer device may also be a terminal, the computer device comprising a processor, a memory, an input/output interface, a communication interface, a display unit and an input means. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device comprises a nonvolatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of an operating system and computer programs in the non-volatile storage medium. The input/output interface of the computer device is used for exchanging information between the processor and an external device. The communication interface of the computer device is used for carrying out wired or wireless communication with an external terminal, and the wireless communication can be realized through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. The computer program is executed by a processor to implement a battery capacity loss testing method.

Those skilled in the art will appreciate that the architecture shown in fig. 9 is merely a block diagram of some of the structures associated with the disclosed aspects and is not intended to limit the computing devices to which the disclosed aspects apply, as particular computing devices may include more or less components than those shown, or may combine certain components, or have a different arrangement of components.

In some embodiments, there is provided a computer device comprising a memory and a processor, the memory having stored therein a computer program, the processor implementing the steps of the battery capacity loss test method described above when executing the computer program.

In some embodiments, a computer-readable storage medium is provided, on which a computer program is stored, which computer program, when being executed by a processor, carries out the steps of the above-mentioned battery capacity loss testing method.

In one embodiment, a computer program product is provided comprising a computer program which, when executed by a processor, performs the steps of the above-described battery capacity loss testing method.

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above may be implemented by hardware instructions of a computer program, which may be stored in a non-volatile computer-readable storage medium, and when executed, may include the processes of the embodiments of the methods described above. Any reference to memory, database, or other medium used in the embodiments provided herein may include at least one of non-volatile and volatile memory. The nonvolatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical Memory, high-density embedded nonvolatile Memory, resistive Random Access Memory (ReRAM), magnetic Random Access Memory (MRAM), ferroelectric Random Access Memory (FRAM), phase Change Memory (PCM), graphene Memory, and the like. Volatile Memory can include Random Access Memory (RAM), external cache Memory, and the like. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM), among others. The databases referred to in various embodiments provided herein may include at least one of relational and non-relational databases. The non-relational database may include, but is not limited to, a block chain based distributed database, and the like. The processors referred to in the embodiments provided herein may be general purpose processors, central processing units, graphics processors, digital signal processors, programmable logic devices, quantum computing based data processing logic devices, etc., without limitation.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present disclosure, and the present disclosure should be construed as being covered by the claims and the specification. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. The present application is not intended to be limited to the particular embodiments disclosed herein but is to cover all embodiments that may fall within the scope of the appended claims.

Claims

1. A method for testing capacity loss of a battery, the method comprising:

2. The method of claim 1, wherein if the battery under test further has an electrode with an operating voltage in a plateau region, the method further comprises:

and obtaining the capacity loss value of the electrode of which the working voltage of the battery to be tested is in the platform area according to the total capacity loss value of the anode and the cathode and the capacity loss value of the target electrode.

3. The method of claim 2, wherein the steps of completely discharging, charging and completely discharging the battery to be tested which is subjected to constant voltage charging according to the preset test duration in sequence, and obtaining the total capacity loss values of the positive electrode and the negative electrode comprise:

completely discharging the battery to be tested which is charged according to the preset test duration again, and recording a second complete discharge capacity;

4. The method of claim 1, wherein before the constant voltage charging of the battery under test, the method further comprises:

acquiring battery state data of the battery to be tested;

and determining a target electrode of the battery to be tested according to the battery state data, wherein the battery state data comprises a mapping relation between SOC and OCV and a current SOC value.

5. The method of claim 4, wherein if it is determined from the battery status data that the target electrode of the battery under test includes a positive electrode and a negative electrode, before the constant voltage charging the battery under test, the method further comprises:

transmitting a three-electrode battery assembly message;

carry out constant voltage charging to the battery that awaits measuring, the leakage current that obtains the target electrode of the battery that awaits measuring that carries out constant voltage charging according to predetermineeing test duration includes:

reading an open-circuit voltage value corresponding to the preset SOC test value;

and carrying out constant voltage charging on the three-electrode battery according to the open-circuit voltage value, and obtaining the positive leakage current and the negative leakage current of the three-electrode battery which is subjected to constant voltage charging according to preset test duration.

6. The method according to any one of claims 1 to 5, wherein the determining the capacity loss value of the target electrode of the battery under test based on the leakage current and the preset test time period comprises:

and carrying out integral operation on the leakage current of the target electrode under the preset test duration to obtain the capacity loss value of the target electrode of the battery to be tested.

7. The method according to any one of claims 1 to 4, wherein if the battery under test has an electrode with an operating voltage in a platform region, the performing constant voltage charging on the battery under test, and obtaining the leakage current of the target electrode of the battery under test that is subjected to constant voltage charging according to a preset test duration comprises:

carrying out constant voltage charging on a battery to be tested for multiple times according to preset test times, and recording the leakage current of a target electrode of the battery to be tested after constant voltage charging is carried out according to preset test duration each time;

8. A battery capacity loss testing apparatus, the apparatus comprising:

the system comprises a data acquisition module, a data acquisition module and a data processing module, wherein the data acquisition module is used for carrying out constant voltage charging on a battery to be tested and acquiring leakage current of a target electrode of the battery to be tested, which carries out constant voltage charging according to preset test duration, and the target electrode comprises an electrode of which the working voltage is in a non-platform area;

and the capacity loss value determining module is used for determining the capacity loss value of the target electrode of the battery to be tested based on the leakage current of the target electrode and the preset testing time length.

9. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor, when executing the computer program, implements the steps of the method of any of claims 1 to 8.

10. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the method of any one of claims 1 to 7.

11. A computer program product comprising a computer program, characterized in that the computer program realizes the steps of the method of any one of claims 1 to 7 when executed by a processor.