Battery binning method, apparatus, medium, and system

Abstract

The present disclosure relates to a battery grading method, device, medium and system. The battery grading method comprises: adjusting a plurality of target batteries to the same state of charge; discharging the plurality of target batteries at the same discharge rate; obtaining a plurality of direct current resistances of the target batteries at a plurality of preset discharge times; determining a resistance difference value of the direct current resistances of the target batteries at any two of the preset discharge times based on the plurality of direct current resistances; determining a root mean square of the target batteries with respect to the resistance difference value based on the resistance difference value; and grading the plurality of target batteries based on the root mean square. The present disclosure determines the root mean square based on the difference value of the direct current resistances by testing the direct current resistances of the batteries at a plurality of discharge times, and grades the batteries based on the root mean square, which can effectively improve the consistency of the batteries in the middle and later stages of the battery pack cycle, prolong the service life of the battery pack, and improve the cruising range of the electric vehicle.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of batteries, and in particular, to a battery grading method, device, medium and system. BACKGROUND

[0002] In recent years, with the continuous development of society, people's living standards are constantly improving, and people's demand for cars is also growing. Due to energy shortages and environmental pollution problems caused by traditional cars, electric cars powered by electricity have emerged.

[0003] Generally, the battery of an electric vehicle uses a lithium battery pack, and the lithium battery pack is composed of hundreds or thousands of lithium batteries through series and parallel connection. The consistency of lithium batteries will directly affect the service life of the battery pack and the cruising range of the electric vehicle. Therefore, it is particularly important to grade the batteries to ensure the consistency of each battery. However, after grading the batteries using existing battery grading methods, due to the polarization of the batteries, the inconsistency of the batteries will still occur in the middle and later stages of battery cycling, affecting the cycle life of the batteries and thus affecting the cruising range of the electric vehicle. SUMMARY

[0004] To solve the above technical problems or at least partially solve the above technical problems, the present disclosure provides a battery grading method, device, medium and system.

[0005] The present disclosure provides a battery grading method, comprising:

[0006] adjusting a plurality of target batteries to the same state of charge;

[0007] discharging the plurality of target batteries at the same discharge rate;

[0008] obtaining a plurality of direct current resistances of the target batteries at a plurality of preset discharge times;

[0009] determining, based on the plurality of direct current resistances, a resistance difference value of the direct current resistances of the target batteries at any two of the preset discharge times;

[0010] determining, based on the resistance difference value, a root mean square of the target batteries with respect to the resistance difference value;

[0011] grading the plurality of target batteries based on the root mean square.

[0012] In some embodiments, at least one of the plurality of direct current resistances only includes an ohmic resistance, and at least one of the plurality of direct current resistances includes at least one of an electrochemical polarization resistance and a concentration polarization resistance and an ohmic resistance.

[0013] In some embodiments, the plurality of preset discharging time points are a plurality of time points in a range from 0.1 second to 120 seconds, and include at least one time point less than or equal to 0.2 second and at least one time point greater than or equal to 1 second.

[0014] In some embodiments, based on the root mean square, the plurality of target batteries are graded, including:

[0015] Based on the size of the root mean square, the plurality of target batteries are sorted in a preset size order;

[0016] According to the arrangement order of the plurality of target batteries, the target batteries meeting a preset grading condition are divided into a grade.

[0017] In some embodiments, the preset grading condition includes:

[0018] The number of target batteries in each grade reaches a preset grading number; or,

[0019] The difference between the maximum value and the minimum value of the root mean square in each grade is less than or equal to a preset threshold.

[0020] In some embodiments, the state of charge ranges from 20% to 90%.

[0021] In some embodiments, the discharging rate ranges from 0.01C to 5C.

[0022] In some embodiments, before adjusting the plurality of target batteries to the same state of charge, the method further includes:

[0023] Preliminary grading of the batteries to be graded;

[0024] Part or all of the batteries to be graded in each grade after preliminary grading are used as the plurality of target batteries.

[0025] In some embodiments, the preliminary grading of the batteries to be graded includes:

[0026] Obtaining an electrical performance parameter of the batteries to be graded, wherein the electrical performance parameter includes at least one of open circuit voltage, alternating current internal resistance, capacity, and self-discharge value;

[0027] Based on the electrical performance parameter, the batteries to be graded are preliminarily graded.

[0028] The present disclosure provides a battery grading device, including:

[0029] A state of charge adjustment module for adjusting a plurality of target batteries to the same state of charge;

[0030] A discharging module for discharging the plurality of target batteries at the same discharging rate;

[0031] The direct current resistance acquisition module is configured to acquire a plurality of direct current resistances of the target battery at a plurality of preset discharge moments.

[0032] The internal resistance difference value determination module is configured to determine, based on the plurality of direct current resistances, an internal resistance difference value of the target battery at any two of the preset discharge moments.

[0033] The root mean square determination module is configured to determine, based on the internal resistance difference value, a root mean square of the target battery with respect to the internal resistance difference value.

[0034] The battery grading module is configured to grade the plurality of target batteries based on the root mean square.

[0035] The present disclosure also provides a computer-readable storage medium storing a program or instructions, which cause a computer to perform the steps of any of the above methods.

[0036] The present disclosure also provides an electronic device, comprising a processor and a memory.

[0037] The processor is configured to perform the steps of any of the above methods by invoking the program or instructions stored in the memory.

[0038] The technical solution provided by the embodiments of the present disclosure has the following advantages compared with the prior art:

[0039] The technical solution provided by the embodiments of the present disclosure has the following advantages compared with the prior art: BRIEF DESCRIPTION OF DRAWINGS

[0040] The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present disclosure and, together with the specification, serve to explain the principles of the present disclosure.

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative labor.

[0042] Figure 1 A flowchart of a battery grading method provided by the embodiments of the present disclosure;

[0043] Figure 2 A cycle curve comparison diagram of the embodiments and comparative examples provided by the embodiments of the present disclosure;

[0044] Figure 3 A structural block diagram of a battery grading device provided by the embodiments of the present disclosure;

[0045] Figure 4 A structural schematic diagram of an electronic device provided by the embodiments of the present disclosure. DETAILED DESCRIPTION

[0046] In order to more clearly illustrate the above-mentioned purposes, features and advantages of the present disclosure, the following will further describe the solutions of the present disclosure. It should be noted that, in the case of no conflict, the embodiments of the present disclosure and the features in the embodiments can be combined with each other.

[0047] In the following description, many specific details are set forth in order to fully understand the present disclosure, but the present disclosure can also be implemented in other different ways from those described herein; obviously, the embodiments in the specification are only some of the embodiments of the present disclosure, not all the embodiments.

[0048] Figure 1 A flowchart of a battery grading method provided by the embodiments of the present disclosure. The method can be executed by a battery grading device, which can be realized in the form of software and / or hardware, and can be applied to an electronic device. The electronic device can be configured on a server or a terminal. The terminal can include a personal computer, a notebook computer, a smart phone and a tablet computer, etc. The server can be realized by an independent server or a server cluster composed of multiple servers. As shown in the figure, the method includes the following steps: Figure 1

[0049] S110, adjusting a plurality of target batteries to the same state of charge.

[0050] S120, discharging the plurality of target batteries at the same discharge rate.

[0051] ​Based on S110 and S120, by adjusting the plurality of target batteries to the same state of charge, discharging the plurality of target batteries at the same state of charge and at the same discharge rate can ensure the accuracy of the battery grading.

[0052] In some embodiments, the state of charge ranges from 20% to 90%. In this way, by specifying the range of the state of charge, the state of charge can be avoided to affect the battery grading. For S110, all target batteries can be adjusted to the same state of charge by charging or discharging according to the current state of charge of each target battery. In the embodiments of the present disclosure, each target battery is a battery of the same type, so the voltage of the target battery can be monitored, and when the voltage of each target battery is the same, it can be determined that the state of charge of each target battery is the same.

[0053] In some embodiments, the discharge rate ranges from 0.01C to 5C. In this way, by specifying the discharge rate, the battery polarization related direct current resistance can be obtained, so that the polarization of the battery after grading tends to be the same. For S120, the plurality of target batteries can be connected in series, and a constant current discharge device can be used to discharge the plurality of target batteries at a certain fixed discharge rate (such as 4C).

[0054] S130, obtaining a plurality of direct current resistances of the target battery at a plurality of preset discharge times.

[0055] In the embodiments of the present disclosure, for each target battery, the direct current resistance at each preset discharge time can be calculated by using the following formula:

[0056] R = (U1-U2) / I 放 ;

[0057] wherein R represents the direct current resistance of the target battery at the current preset discharge time; U1 represents the voltage of the target battery before discharging; U2 represents the voltage of the target battery at the current preset discharge time; and I 放 represents the discharging current.

[0058] In view of the influence of battery polarization, the battery generates an electrochemical polarization internal resistance and / or a concentration polarization internal resistance with the increase of the discharge time, and changes over time. Therefore, to improve the influence of battery polarization, the DC internal resistances obtained at the plurality of preset discharge moments should distinguish the ohmic resistance, the electrochemical polarization internal resistance and the concentration polarization internal resistance, so as to ensure that the polarization conditions of the target batteries in the same grade after grading tend to be the same. Based on this, in some embodiments, at least one of the plurality of DC internal resistances only includes the ohmic internal resistance, and at least one of the plurality of DC internal resistances includes at least one of the electrochemical polarization internal resistance and the concentration polarization internal resistance and the ohmic internal resistance. In one implementable manner, for each target battery, the plurality of DC internal resistances includes a first DC internal resistance, a second DC internal resistance and a third DC internal resistance, wherein the first DC internal resistance is the ohmic internal resistance, the second DC internal resistance includes the ohmic internal resistance and the electrochemical polarization internal resistance or the concentration polarization internal resistance, and the third DC internal resistance includes the ohmic internal resistance, the electrochemical polarization internal resistance and the concentration polarization internal resistance. In this way, the ohmic internal resistance, the electrochemical polarization internal resistance and the concentration polarization internal resistance can be accurately distinguished, the changes of the DC internal resistance caused by battery polarization are fully considered, and it is ensured that the polarization conditions of the target batteries in the same grade after grading tend to be the same.

[0059] Based on the above technical solution, to obtain the DC internal resistance that can distinguish the ohmic internal resistance, the electrochemical polarization internal resistance and the concentration polarization internal resistance, in some embodiments, the plurality of preset discharge moments are a plurality of moments in 0.1 seconds to 120 seconds, and include at least one moment less than or equal to 0.2 seconds and at least one moment greater than or equal to 1 second. Specifically, when the preset discharge moment is less than or equal to 0.2 seconds (such as 0.1 second), the DC internal resistance of the battery can be approximated to the ohmic internal resistance; when the preset discharge moment is greater than or equal to 1 second, the DC internal resistance of the battery includes the ohmic internal resistance, the electrochemical polarization internal resistance and / or the concentration polarization internal resistance. At present, the existing equipment still cannot accurately measure the size and generation time of the electrochemical polarization internal resistance and the concentration polarization internal resistance, and the generation time of the electrochemical polarization internal resistance and the concentration polarization internal resistance is different under different environments (such as temperature, discharge current and battery structure). Therefore, the DC internal resistance at a plurality of discharge moments can be selected when the battery discharge time is greater than or equal to 1 second, so as to improve the accuracy of the DC internal resistance that distinguishes the ohmic internal resistance, the electrochemical polarization internal resistance and the concentration polarization internal resistance as much as possible. In one implementable manner, the plurality of preset discharge moments can include 0.1 seconds, 1 second, 10 seconds, 30 seconds and 60 seconds.

[0060] It should be noted that the starting moment of the discharge of the target battery can be recorded as 0 seconds, and the timing starts from 0 seconds, and any subsequent moment is referred to the 0 seconds.

[0061] S140, based on the plurality of DC internal resistances, determining the internal resistance difference value of the DC internal resistance of the target battery at any two preset discharge moments.

[0062] In some embodiments, the resistance difference value of the DC internal resistance of the target battery at any two adjacent preset discharge moments can be determined based on the plurality of DC internal resistances, so that the calculation amount can be greatly reduced while ensuring the accuracy of battery grading. In the embodiments of the present disclosure, for each target battery, the resistance difference value of the DC internal resistance of the target battery at any two adjacent preset discharge moments can be calculated by using the following formula:

[0063] D n-1 =R n -R n-1 ;

[0064] wherein R n represents the DC internal resistance of the target battery at the nth preset discharge moment, R n-1 represents the DC internal resistance of the target battery at the (n-1)th preset discharge moment, and n is an integer greater than or equal to 2.

[0065] In one implementation, the plurality of DC internal resistances of the target battery at 0.1 seconds, 1 second, 10 seconds, 30 seconds and 60 seconds are obtained, and are denoted as R1, R2, R3, R4 and R5 respectively. At this time, the resistance difference values of the DC internal resistance of the target battery at any two adjacent preset discharge moments are D1, D2, D3 and D4 respectively, wherein D1=R2-R1, D2=R3-R2, D3=R4-R3 and D4=R5-R4.

[0066] S150, determining the root mean square of the resistance difference value of the target battery based on the resistance difference value.

[0067] In the embodiments of the present disclosure, for each target battery, the root mean square of the resistance difference value of the target battery can be calculated by using the following formula:

[0068]

[0069] S160, grading the plurality of target batteries based on the root mean square.

[0070] In some embodiments, grading the plurality of target batteries based on the root mean square can include the following steps:

[0071] S161, sorting the plurality of target batteries in a preset size order based on the size of the root mean square.

[0072] In some embodiments, the preset size order can be from large to small or from small to large.

[0073] S162, dividing the target batteries meeting the preset grading condition into one grade according to the arrangement order of the plurality of target batteries.

[0074] In some embodiments, the target batteries can be binned according to the number of target batteries in the order of arrangement of the target batteries. In one implementation, the preset binning condition includes that the number of target batteries in each bin reaches a preset binning number. Specifically, the first target battery is counted in the order of arrangement of the target batteries, and when the count reaches the preset binning number, the counted target batteries are divided into a bin. Then, the next target battery is counted again, and when the count reaches the preset bining number, the counted target batteries are divided into another bin. In this way, the binning of all target batteries is completed. The preset binning number is determined according to actual conditions.

[0075] In some embodiments, the target batteries can be binned according to the difference of the root mean square in the order of arrangement of the target batteries. In one implementation, the preset binning condition includes that the difference between the maximum and minimum of the root mean square in each bin is less than or equal to a preset threshold. Specifically, the root mean square corresponding to the first target battery is taken as the maximum of the root mean square of the first bin in the order of arrangement of the target batteries, and then the root mean square of the subsequent target battery is compared with the maximum of the root mean square. The subsequent target battery with a root mean square difference less than or equal to the preset threshold is binned with the first target battery. Then, the target battery with a first root mean square difference greater than the preset threshold is taken as the first target battery of another bin, and the above steps are repeated to divide another bin of target batteries. In this way, the binning of all target batteries is completed. The preset threshold is determined according to actual conditions.

[0076] The battery binning method provided by the embodiments of the present disclosure obtains the plurality of direct current resistances of the target battery at the plurality of preset discharge moments, then determines the resistance difference of the direct current resistance of the target battery at any two adjacent preset discharge moments based on the plurality of direct current resistances, determines the root mean square of the target battery with respect to the resistance difference based on the resistance difference, and finally bins the plurality of target batteries based on the root mean square. In this way, the root mean square is determined according to the plurality of direct current resistances obtained at different discharge moments, the influence of battery polarization is considered, the polarization of the target batteries binned in this way tends to be the same, thereby effectively improving the consistency of the battery pack in the middle and later stages of the cycle, prolonging the service life of the battery pack, and improving the cruising range of the electric vehicle. In addition, the technical scheme of the present disclosure can be realized by the existing binning equipment, without the need to increase new equipment, low cost, and strong practicability.

[0077] In some embodiments, before adjusting the plurality of target batteries to the same state of charge, the method further comprises:

[0078] S210, the battery to be binned is preliminarily binned.

[0079] The preliminary grading is the conventional grading. In an embodiment, an electrical performance parameter of the battery to be graded is obtained, and the battery to be graded is preliminarily graded based on the electrical performance parameter, wherein the electrical performance parameter includes at least one of open circuit voltage, alternating current resistance, capacity and self-discharge value. Specifically, for the open circuit voltage, the batteries to be graded can be sequentially arranged based on the size of the open circuit voltage, and the batteries to be graded with a difference of less than 5 millivolts in the open circuit voltage are classified into one grade according to the arrangement order of the batteries to be graded. For the alternating current resistance, the batteries to be graded can be sequentially arranged based on the size of the alternating current resistance, and the batteries to be graded with a difference of less than 0.05 milliohm in the alternating current resistance are classified into one grade according to the arrangement order of the batteries to be graded. For the capacity, the batteries to be graded can be sequentially arranged based on the size of the capacity, and the batteries to be graded with a difference of less than 0.5 ampere-hour in the capacity are classified into one grade according to the arrangement order of the batteries to be graded. For the self-discharge value, the batteries to be graded can be sequentially arranged based on the size of the self-discharge value, and the batteries to be graded with a difference of less than 0.002 millivolt per hour in the self-discharge value are classified into one grade according to the arrangement order of the batteries to be graded.

[0080] S220, part or all of the batteries to be graded in each grade after the preliminary grading are selected as the target batteries.

[0081] Part or all of the batteries to be graded in each grade after the preliminary grading can be selected as the target batteries according to actual needs.

[0082] The embodiments of the present disclosure can not only eliminate the batteries with poor consistency, but also further grade the batteries in each grade after the conventional grading, thereby improving the consistency of the batteries in each grade after the further grading.

[0083] Based on the above technical solutions, the present disclosure further provides specific embodiments and comparative examples to illustrate the significance of the technical effects of the present disclosure.

[0084] Comparative Example 1

[0085] Taking a square cell battery model 44*220*102mm-160Ah as an example, 4000 batteries graded according to the conventional grading are selected, and 228 batteries are randomly selected to form a 1P228 battery pack.

[0086] Comparative Example 2

[0087] In Comparative Example 1, 1000 batteries were randomly selected, and the state of charge of the batteries was adjusted to 50%; the batteries were discharged at 0.2C for 10 seconds, charged at 0.2C for 10 seconds; discharged at 0.5C for 10 seconds, charged at 0.5C for 10 seconds; discharged at 1C for 10 seconds, charged at 1C for 10 seconds; discharged at 2C for 10 seconds, charged at 2C for 10 seconds; discharged at 3C for 10 seconds, charged at 3C for 10 seconds; the direct current internal resistance of the 10-second pulse discharge at 0.2C, 0.5C, 1C, 2C and 3C was calculated respectively, D1' was obtained by subtracting the direct current internal resistance at 0.5C from the direct current internal resistance at 0.2C, D2' was obtained by subtracting the direct current internal resistance at 1C from the direct current internal resistance at 0.5C, D3' was obtained by subtracting the direct current internal resistance at 2C from the direct current internal resistance at 1C, and D4' was obtained by subtracting the direct current internal resistance at 3C from the direct current internal resistance at 2C. D0' was obtained by calculating the arithmetic mean of D1', D2', D3' and D4'. D0' was sorted from large to small, and each 228 batteries were divided into a grade.

[0088] Example

[0089] Table 1 is the grading data of part of the batteries after grading,

[0090]

[0091] In Comparative Example 1, 1000 batteries were randomly selected, and the state of charge of the batteries was adjusted to 50%; the batteries were discharged at 0.2C for 10 seconds, charged at 0.2C for 10 seconds; the direct current internal resistance at 0.1 second, 1 second, 10 seconds, 30 seconds and 60 seconds was obtained; D1 was obtained by subtracting the direct current internal resistance at 1 second from the direct current internal resistance at 0.1 second, D2 was obtained by subtracting the direct current internal resistance at 10 seconds from the direct current internal resistance at 1 second, D3 was obtained by subtracting the direct current internal resistance at 30 seconds from the direct current internal resistance at 10 seconds, and D4 was obtained by subtracting the direct current internal resistance at 60 seconds from the direct current internal resistance at 30 seconds. D0 was obtained by calculating the root mean square of D1, D2, D3 and D4. D0 was sorted from large to small, and each 228 batteries were divided into a grade. Table 1 is the grading data of part of the batteries after grading, Figure 2 The cycle curves of the examples and the comparative examples are compared in the following figure. Figure 2 It can be seen that, as the number of cycles of the battery pack increases, the capacity retention rate of the example is always greater than that of Comparative Examples 1 and 2, which shows that, compared with the technical solutions of Comparative Examples 1 and 2, the battery consistency after grading of the technical solution of the present disclosure is better, which can effectively improve the consistency of the battery pack in the middle and later stages of the cycle, and prolong the service life of the battery pack. In addition, compared with the technical solution of Comparative Example 2, the technical solution of the present disclosure does not need to perform the steps of discharging and charging back and forth, but only needs to discharge once to obtain the required data, and the operation is relatively simple, thereby improving the battery grading efficiency.

[0092] Corresponding to the battery grading method provided by the embodiment of the present disclosure, the embodiment of the present disclosure also provides a battery grading device. Figure 3A structural block diagram of the battery grading device provided by the embodiments of the present disclosure is shown in Figure 3 The battery grading device comprises:

[0093] A state of charge adjustment module 21 is configured to adjust the plurality of target batteries to the same state of charge.

[0094] A discharging module 22 is configured to discharge the plurality of target batteries at the same discharge rate.

[0095] A direct current internal resistance acquisition module 23 is configured to acquire a plurality of direct current internal resistances of the target battery at a plurality of preset discharging time points.

[0096] An internal resistance difference value determination module 24 is configured to determine, based on the plurality of direct current internal resistances, an internal resistance difference value of the direct current internal resistances of the target battery at any two preset discharging time points.

[0097] A root mean square determination module 25 is configured to determine, based on the internal resistance difference value, a root mean square of the target battery with respect to the internal resistance difference value.

[0098] A battery grading module 26 is configured to grade the plurality of target batteries based on the root mean square.

[0099] In some embodiments, at least one of the plurality of direct current internal resistances only comprises an ohmic internal resistance, and at least one of the plurality of direct current internal resistances comprises at least one of an electrochemical polarization internal resistance and a concentration polarization internal resistance and an ohmic internal resistance.

[0100] In some embodiments, the plurality of preset discharging time points are a plurality of time points in a range from 0.1 seconds to 120 seconds, and at least one time point is less than or equal to 0.2 seconds and at least one time point is greater than or equal to 1 second.

[0101] In some embodiments, the battery grading module 26 comprises:

[0102] A battery sorting unit is configured to sort the plurality of target batteries in a preset size order based on the size of the root mean square.

[0103] A battery grading unit is configured to grade the target batteries that meet a preset grading condition into a grade according to the arrangement order of the plurality of target batteries.

[0104] In some embodiments, the preset grading condition comprises:

[0105] The number of target batteries in each grade reaches a preset grading number; or,

[0106] The difference between the maximum value and the minimum value of the root mean square in each grade is less than or equal to a preset threshold value.

[0107] In some embodiments, the state of charge ranges from 20% to 90%.

[0108] In some embodiments, the discharge rate ranges from 0.01C to 5C.

[0109] In some embodiments, the battery grading device further comprises:

[0110] a battery preliminary grading module, configured to preliminarily grade the to-be-graded batteries before adjusting the plurality of target batteries to the same state of charge.

[0111] a target battery determination module, configured to determine part or all of the to-be-graded batteries in each grade after the preliminary grading as the plurality of target batteries.

[0112] In some embodiments, the battery preliminary grading module comprises:

[0113] an electrical performance parameter acquisition unit, configured to acquire an electrical performance parameter of the to-be-graded batteries, wherein the electrical performance parameter comprises at least one of open circuit voltage, alternating current internal resistance, capacity and self-discharge value.

[0114] a battery preliminary grading unit, configured to preliminarily grade the to-be-graded batteries based on the electrical performance parameter.

[0115] The battery grading device disclosed in the above embodiments can perform the battery grading method disclosed in the above embodiments, and has the same or corresponding beneficial effects. To avoid repetition, details are not described herein.

[0116] The embodiments of the present disclosure further provide a computer readable storage medium storing programs or instructions, which cause a computer to execute the steps of any of the above methods.

[0117] Exemplarily, the programs or instructions cause the computer to execute a battery grading method, which comprises:

[0118] adjusting a plurality of target batteries to the same state of charge;

[0119] discharging the plurality of target batteries at the same discharge rate;

[0120] acquiring a plurality of direct current internal resistances of the target batteries at a plurality of preset discharging time points;

[0121] determining, based on the plurality of direct current internal resistances, a difference value of direct current internal resistance of the target batteries at any two of the preset discharging time points;

[0122] determining, based on the difference value of direct current internal resistance, a root mean square of the target batteries with respect to the difference value of direct current internal resistance;

[0123] grading the plurality of target batteries based on the root mean square.

[0124] Optionally, the computer executable instructions, when executed by the computer processor, can also be used to implement the technical solutions of any of the battery grading methods provided by the embodiments of the present disclosure to achieve the corresponding beneficial effects.

[0125] Through the above description of the embodiments, those skilled in the art can clearly understand that the embodiments of the present disclosure can be realized by means of software and necessary universal hardware, and of course can also be realized by hardware, but in many cases the former is a better embodiment. Based on such understanding, the technical solutions of the embodiments of the present disclosure can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as a floppy disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a FLASH memory, a hard disk, or an optical disc, and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in various embodiments of the present disclosure.

[0126] Based on the above embodiments, the embodiments of the present disclosure further provide an electronic device, comprising: a processor and a memory; the processor is configured to execute the steps of any of the above methods by invoking the program or instructions stored in the memory, to achieve the corresponding beneficial effects.

[0127] In some embodiments, Figure 4 The structure of an electronic device provided by the embodiments of the present disclosure is shown. Referring to Figure 4 The electronic device can include:

[0128] one or more processors 301, Figure 4 In the foregoing embodiments, the processor 301 is taken as an example.

[0129] a memory 302;

[0130] The electronic device can further include an input device 303 and an output device 304.

[0131] The processor 301, the memory 302, the input device 303 and the output device 304 in the electronic device can be connected by a bus or other means, Figure 4 In the foregoing embodiments, the connection mode is exemplarily illustrated by taking the connection by the bus as an example.

[0132] The memory 302 as a non-transitory computer readable storage medium can be used to store software programs, computer executable programs and modules, such as program instructions / modules corresponding to the method of the application program in the embodiments of the present disclosure (for example, the above-mentioned method for grading the battery). Figure 3The illustrated state of charge adjustment module 21, discharge module 22, DC internal resistance acquisition module 23, internal resistance difference value determination module 24, root mean square determination module 25, and battery grading module 26). The processor 301 performs various functional applications and data processing of the server by running software programs, instructions, and modules stored in the memory 302, that is, implements the method of the above method embodiments.

[0133] The memory 302 can include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application required by a function; the data storage area can store data created according to the use of the electronic device, etc.

[0134] In addition, the memory 302 can include a high-speed random access memory, and can also include a non-transitory memory, such as at least one magnetic disk storage device, a flash memory device, or other non-transitory solid-state memory device.

[0135] In some embodiments, the memory 302 can optionally include a memory remotely disposed relative to the processor 301, which can be connected to the terminal device through a network. Examples of the above-mentioned network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0136] The input device 303 can be used to receive input digital or character information, and generate key signal input related to user settings and function control of the electronic device.

[0137] The output device 304 can include a display device such as a display screen.

[0138] In the embodiments of the present disclosure, the electronic device can be a battery management system, a controller, a server, or a terminal, etc. capable of executing the battery grading method of the embodiments of the present disclosure, and is not limited thereto.

[0139] It should be noted that in this paper, relationship terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the statement "including a…" does not exclude the presence of another identical element in the process, method, article or device including the element.

[0140] The foregoing is merely illustrative of the various implementations of the present disclosure and the general principles thereof. Numerous modifications can be made to these illustrations, and equivalents can be substituted therefor, without departing from the scope of the present disclosure. The specific embodiments commensurate with the specific application are intended to be illustrative only and not limiting of the scope of the application as set forth in the following claims.

Claims

1. A battery grading method, characterized in that, include: Adjust multiple target batteries to the same state of charge; The multiple target batteries are discharged at the same discharge rate; Obtain multiple DC internal resistances of the target battery at multiple preset discharge times; Based on the multiple DC internal resistances, the internal resistance difference of the target battery at any two adjacent preset discharge times is determined. Based on the internal resistance difference, determine the root mean square of the target battery with respect to the internal resistance difference; Based on the root mean square, the multiple target batteries are categorized.

2. The method according to claim 1, characterized in that, At least one of the plurality of DC internal resistances includes only ohmic internal resistance, and at least one of the plurality of DC internal resistances includes at least one of electrochemical polarization internal resistance and concentration polarization internal resistance as well as ohmic internal resistance.

3. The method according to claim 2, characterized in that, The plurality of preset discharge times are multiple times ranging from 0.1 seconds to 120 seconds, including at least one time less than or equal to 0.2 seconds and at least one time greater than or equal to 1 second.

4. The method according to claim 1, characterized in that, Based on the root mean square (RMS), the plurality of target batteries are categorized, including: Based on the root mean square value, the multiple target batteries are sorted according to a preset size order; According to the arrangement order of the multiple target batteries, the target batteries that meet the preset grading conditions are divided into one grade.

5. The method according to claim 4, characterized in that, The preset grading conditions include: The number of target batteries in each grade reaches the preset grade number; or... The difference between the maximum and minimum values ​​of the root mean square in each range is less than or equal to a preset threshold.

6. The method according to claim 1, characterized in that, The state of charge ranges from 20% to 90%.

7. The method according to claim 1, characterized in that, The discharge rate ranges from 0.01C to 5C.

8. The method according to claim 1, characterized in that, The method further includes, prior to adjusting multiple target batteries to the same state of charge: Perform initial grading of the batteries to be graded; Some or all of the batteries to be categorized in each of the initial categorizations are used as the multiple target batteries.

9. The method according to claim 8, characterized in that, The batteries to be categorized are initially categorized, including: Obtain the electrical performance parameters of the battery to be categorized, wherein the electrical performance parameters include at least one of open-circuit voltage, AC internal resistance, capacity, and self-discharge value; The batteries to be classified are initially classified based on the electrical performance parameters.

10. A battery grading device, characterized in that, include: A state of charge adjustment module is used to adjust multiple target batteries to the same state of charge. A discharge module is used to discharge the plurality of target batteries at the same discharge rate; A DC internal resistance acquisition module is used to acquire multiple DC internal resistances of the target battery at multiple preset discharge times; The internal resistance difference determination module is used to determine the internal resistance difference of the target battery at any two adjacent preset discharge times based on the plurality of DC internal resistances. The root mean square (RMS) determination module is used to determine the root mean square of the target battery with respect to the internal resistance difference based on the internal resistance difference. A battery grading module is used to categorize the multiple target batteries based on the root mean square (RMS).

11. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a program or instructions that cause a computer to perform the steps of the method as described in any one of claims 1 to 9.

12. An electronic device, characterized in that, include: Processor and memory; The processor executes the steps of the method as described in any one of claims 1 to 9 by invoking programs or instructions stored in the memory.

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