Lithium ion battery consistency screening method and system based on infrared thermal imaging technology

Abstract

The invention discloses a lithium ion battery consistency screening method and system based on an infrared thermal imaging technology, and relates to the technical field of lithium ion battery consistency screening, and the method comprises the steps: carrying out the central point symmetric arrangement of lithium ion batteries to be detected, and connecting the arranged lithium ion batteries in series to form a lithium ion battery pack, placing the central point of the lithium ion battery pack and the central point of the lens of the infrared thermal imager on the same vertical straight line; charging and discharging testing is carried out on the lithium ion battery pack, the highest temperature change sequence of each lithium ion battery is obtained, pairwise similarity comparison analysis is carried out on the highest temperature change sequence of each lithium ion battery based on a dynamic time planning method, and the minimum distance value between the two temperature change sequences is obtained through output; and comparing the minimum distance value between all the two temperature change sequences with a preset threshold value, determining the lithium ion battery with the minimum distance value smaller than the preset threshold value as the lithium ion battery with good consistency, otherwise, determining the lithium ion battery with poor consistency, and re-screening and re-arranging the lithium ion batteries with poor consistency until all the lithium ion batteries with good consistency are screened out.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium ion battery consistency screening, and in particular to a lithium ion battery consistency screening method and system based on infrared thermal imaging technology. Background Art

[0002] Currently, lithium-ion batteries are the preferred energy source and core energy storage device for consumer electronic devices and new energy vehicles. Lithium-ion batteries and the new energy industry they represent have maintained sustained rapid growth. Lithium-ion batteries have many advantages such as high voltage, high energy density, low cost and rechargeability.

[0003] Lithium-ion batteries are composed of positive electrode materials, negative electrode materials, separators, electrolytes and other accessories. They need to maintain a high degree of consistency when used in groups in order to maximize the capacity of each battery and reduce overcharging and over-discharging. However, in the production and manufacturing process of lithium-ion batteries, the existing technology is difficult to ensure that the internal structure and materials are completely consistent, so there will be differences in parameters such as capacity and internal resistance. At the same time, during the service process of lithium-ion batteries, due to long-term circulation and heat generation, the battery will produce irreversible changes such as capacity loss and increased internal resistance. Different aging behaviors will be exhibited due to different environments, resulting in overall inconsistency of the battery pack.

[0004] Currently, the screening of lithium-ion battery consistency is mainly focused on different forms of capacity sorting. However, the capacity sorting of single cells is time-consuming and requires the disassembly of old battery packs. Summary of the invention

[0005] In order to solve the deficiencies mentioned in the above background technology, the purpose of the present invention is to provide a lithium-ion battery consistency screening method and system based on infrared thermal imaging technology to solve the problem that the existing lithium-ion battery consistency screening is time-consuming and inefficient.

[0006] In the first aspect, the purpose of the present invention can be achieved by the following technical solution: a lithium ion battery consistency screening method based on infrared thermal imaging technology, the method comprising the following steps:

[0007] Arrange the lithium-ion batteries to be tested symmetrically at their center points, connect the arranged lithium-ion batteries in series to form a lithium-ion battery pack, and place the center point of the lithium-ion battery pack and the center point of the infrared thermal imager lens on the same vertical line;

[0008] Perform charge and discharge tests on the lithium-ion battery pack to obtain the maximum temperature change sequence of each lithium-ion battery, perform pairwise similarity comparison analysis on the maximum temperature change sequence of each lithium-ion battery based on the dynamic time planning method, and output the minimum distance value between two temperature change sequences;

[0009] The minimum distance value between all two temperature change sequences is compared with a preset threshold value. Lithium-ion batteries with a minimum distance value less than the preset threshold value are judged to have good consistency, otherwise they are lithium-ion batteries with poor consistency. The lithium-ion batteries with poor consistency are re-screened and rearranged until all lithium-ion batteries with good consistency are screened out.

[0010] In combination with the first aspect, in some implementations of the first aspect, the method further includes: the process of placing the center point of the lithium-ion battery pack and the center point of the infrared thermal imager lens on the same vertical line:

[0011] Attach thermal tape to the top of each lithium-ion battery facing the infrared thermal imager, point the infrared thermal imager lens downward, and place the lithium-ion battery pack at a preset distance below the infrared thermal imager so that the center point of the lithium-ion battery pack and the center point of the infrared thermal imager lens are in a vertical line.

[0012] In combination with the first aspect, in certain implementations of the first aspect, the method further includes: the material of the thermally conductive tape is acrylic pressure-sensitive adhesive to remove reflective interference caused by the smooth surfaces of the positive and negative electrodes of the lithium-ion battery in the infrared thermal imaging test.

[0013] In combination with the first aspect, in some implementations of the first aspect, the method further includes: the infrared thermal imager collects infrared temperature data once every 30 seconds, and the emissivity is set to 0.90.

[0014] In combination with the first aspect, in some implementations of the first aspect, the method further includes: the process of performing a charge and discharge test on the lithium-ion battery pack:

[0015] Connect the lithium-ion battery pack to the charge and discharge tester, and connect the charge and discharge tester to the computer to set the following charge and discharge parameters: constant current discharge 1.00C until the voltage is less than the discharge cut-off voltage of the single lithium-ion battery × the number of batteries in series, constant current charge 1.00C until the voltage is greater than or equal to the charge cut-off voltage of the single lithium-ion battery × the number of batteries in series, constant voltage charge, the voltage = the charge cut-off voltage of the single lithium-ion battery × the number of batteries in series, until the current is less than 0.02C, constant current discharge 1.00C until the voltage is less than the discharge cut-off voltage of the single lithium-ion battery × the number of batteries in series.

[0016] In combination with the first aspect, in certain implementations of the first aspect, the method further includes: the calculation process of performing pairwise similarity comparison analysis on the maximum temperature change sequence of each lithium-ion battery based on the dynamic time planning method is as follows:

[0017] For two time-varying temperature sequence vectors X(i), i = 1, 2, ..., m and Y(j), j = 1, 2, ..., n, a distance table is constructed using the distance function D(i, j), which is defined as follows:

[0018]

[0019] Finally, when i=m, j=n, D(m,n) is the minimum distance value between two temperature change sequences.

[0020] In combination with the first aspect, in certain implementations of the first aspect, the method further includes: the dynamic time planning method processes two temperature change sequences with the same arrangement but different test times: for the case where m≠n exists.

[0021] In the second aspect, in order to achieve the above-mentioned purpose, the present invention discloses a lithium-ion battery consistency screening system based on infrared thermal imaging technology, comprising:

[0022] The battery arrangement module is used to arrange the lithium-ion batteries to be tested symmetrically at their center points, connect the arranged lithium-ion batteries in series to form a lithium-ion battery pack, and place the center point of the lithium-ion battery pack and the center point of the infrared thermal imager lens on the same vertical line;

[0023] A sequence analysis module is used to perform charge and discharge tests on lithium-ion battery packs, obtain the highest temperature change sequence of each lithium-ion battery, perform pairwise similarity comparison analysis on the highest temperature change sequence of each lithium-ion battery based on a dynamic time planning method, and output the minimum distance value between two temperature change sequences;

[0024] The consistency screening module is used to compare the minimum distance value between all two temperature change sequences with a preset threshold value. Lithium-ion batteries with a minimum distance value less than the preset threshold value are judged to have good consistency, otherwise they are lithium-ion batteries with poor consistency. The lithium-ion batteries with poor consistency are re-screened and arranged until all lithium-ion batteries with good consistency are screened out.

[0025] In another aspect of the present invention, in order to achieve the above-mentioned purpose, a terminal device is disclosed, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor, wherein the memory stores a computer program capable of running on the processor, and when the processor loads and executes the computer program, the lithium-ion battery consistency screening method based on infrared thermal imaging technology as described above is adopted.

[0026] In another aspect of the present invention, in order to achieve the above-mentioned purpose, a computer-readable storage medium is disclosed, in which a computer program is stored. When the computer program is loaded and executed by a processor, the lithium-ion battery consistency screening method based on infrared thermal imaging technology as described above is adopted.

[0027] Beneficial effects of the present invention:

[0028] The present invention arranges or analyzes lithium-ion batteries in a center-point symmetrical manner, and can eliminate the mutual influence of heat generation of batteries in a lithium-ion battery pack when performing infrared thermal imaging temperature testing, with high accuracy; the use of a dynamic time planning method can flexibly handle complex situations such as nonlinearity and time delay, and can compare lithium-ion batteries in different screening rounds; the present invention can perform consistency screening by performing a single cycle test on multiple batteries, and is particularly suitable for large-scale, group-arranged lithium-ion batteries and battery packs, and the more batteries are tested in a single test, the higher the consistency screening efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 It is a schematic flow chart of the method of the present invention;

[0031] Figure 2 is a flow chart of a method for implementing the present invention;

[0032] Figure 3 It is a structural schematic diagram of the infrared thermal imaging test of the present invention;

[0033] Figure 4 The embodiment tests the temperature change process of each lithium-ion battery;

[0034] Figure 5 It is a schematic diagram of the system structure of the present invention;

[0035] Figure 6 This is an infrared thermal imaging image of a battery pack of the present invention;

[0036] In the picture: 1. Infrared thermal imager; 2. Lithium-ion battery to be tested. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Embodiment 1:

[0039] The following is an introduction to the relevant terms involved in the embodiments of the present application:

[0040] Lithium-ion battery is a secondary battery (rechargeable battery) that mainly relies on the movement of lithium ions between the positive and negative electrodes to work. + Insertion and deinsertion back and forth between the two electrodes: During charging, Li + It is deintercalated from the positive electrode and intercalated into the negative electrode through the electrolyte, and the negative electrode is in a lithium-rich state; the opposite is true during discharge.

[0041] like Figure 1 As shown, a lithium-ion battery consistency screening method based on infrared thermal imaging technology includes the following steps:

[0042] S101: Arrange the lithium-ion batteries 2 to be tested symmetrically at their center points, connect the arranged lithium-ion batteries in series to form a lithium-ion battery pack, and place the center point of the lithium-ion battery pack and the center point of the infrared thermal imager 1 lens on the same vertical line;

[0043] The process of placing the center point of the lithium-ion battery pack and the center point of the infrared thermal imager 1 lens on the same vertical line:

[0044] Attach thermal conductive tape to the top of each lithium-ion battery facing the infrared thermal imager 1, point the infrared thermal imager 1 lens downward, and place the lithium-ion battery pack at a preset distance of 10-15 cm below the infrared thermal imager 1, so that the center point of the lithium-ion battery pack and the center point of the infrared thermal imager 1 lens are in a vertical straight line.

[0045] The material of the thermal conductive tape is acrylic pressure-sensitive adhesive, which removes the reflective interference caused by the smooth surfaces of the positive and negative electrodes of the lithium-ion battery in the infrared thermal imaging test.

[0046] The infrared thermal imager 1 collects infrared temperature data every 30 seconds, the emissivity is set to 0.90, and is connected to a computer to store the captured data.

[0047] S102: performing a charge and discharge test on the lithium-ion battery pack to obtain a maximum temperature change sequence of each lithium-ion battery, performing a pairwise similarity comparison analysis on the maximum temperature change sequence of each lithium-ion battery based on a dynamic time planning method, and outputting a minimum distance value between two temperature change sequences;

[0048] Perform a charge and discharge test on the lithium-ion battery pack, connect the lithium-ion battery pack to the charge and discharge tester, and connect the charge and discharge tester to the computer to set the following charge and discharge parameters: constant current discharge (1.00C) to voltage < single lithium-ion battery discharge cut-off voltage × number of batteries in series, constant current charge (1.00C) to voltage ≥ single lithium-ion battery charge cut-off voltage × number of batteries in series, constant voltage charge (voltage = single lithium-ion battery charge cut-off voltage × number of batteries in series) to current <0.02C, constant current discharge (1.00C) to voltage < single lithium-ion battery discharge cut-off voltage × number of batteries in series. Obtain the highest temperature change sequence in the thermal conductive adhesive coverage area on the top of each lithium-ion battery during the charge and discharge test.

[0049] S103: Compare the minimum distance value between all two temperature change sequences with a preset threshold value, and determine that the lithium-ion batteries with a minimum distance value less than the preset threshold value are lithium-ion batteries with good consistency, otherwise, they are lithium-ion batteries with poor consistency. The lithium-ion batteries with poor consistency are re-screened and arranged until all lithium-ion batteries with good consistency are screened out.

[0050] The dynamic time planning method is used to perform pairwise similarity comparison analysis on the battery temperature change sequences that are arranged symmetrically at the center point or in groups of old lithium-ion battery packs that are arranged symmetrically at the center point. For two time-varying temperature sequence vectors X(i), i=1,2,…,m and Y(j), j=1,2,…,n, the distance function D(i,j) is used to construct a distance table, which is defined as follows:

[0051]

[0052] Finally, when i=m, j=n, D(m,n) is the minimum distance value between two temperature change sequences. The smaller the value, the more similar the two temperature change sequences are, and the higher the consistency of the corresponding two lithium-ion batteries.

[0053] The dynamic time planning method can handle two temperature change sequences with the same arrangement but different test times, that is, the possible situation of m≠n.

[0054] After analyzing all the temperature change sequences pairwise, sort the D(m,n) values ​​from small to large, compare the values, and select the lithium-ion battery with better consistency from small to large according to the required consistency.

[0055] 0≤D(m,n) value<50, good consistency; 50≤D(m,n) value<200, fair consistency; D(m,n) value>200, poor consistency.

[0056] The lithium-ion batteries with good consistency are assembled into battery packs or reserved for backup. The lithium-ion batteries with poor consistency are rearranged and screened again until all different lithium-ion battery combinations with good consistency are screened out.

[0057] Specifically, the present invention is further described below by way of embodiments:

[0058] Four lithium-ion batteries were selected, all of which had ternary nickel-manganese-cobalt cathode materials and were numbered 1#, 2#, 3# and 4#. Their actual capacities were 1#: 2.4686Ah, 2#: 2.4762Ah, 3#: 2.0542Ah, and 4#: 2.4647Ah.

[0059] 4 lithium-ion batteries Figure 3 They are arranged symmetrically at the center point and connected in series in the order of 1#, 2#, 3# and 4#. Thermal conductive tape is pasted on the top, and the lens of infrared thermal imager 1 is facing downward. The lithium-ion battery pack is placed 10 cm below the infrared thermal imager 1, so that the center point of the lithium-ion battery pack and the center point of the lens of infrared thermal imager 1 are in a vertical line. The infrared thermal imager 1 is set to collect infrared temperature data every 30 seconds, and the emissivity is set to 0.90.

[0060] Connect the lithium-ion battery pack to the charge and discharge tester, and set the charge and discharge parameters as follows: constant current discharge (1.00C, 2600mA) until the voltage is less than 11V, constant current charge (1.00C, 2600mA) until the voltage is ≥16.8V, constant voltage charge (16.8V) until the current is less than 50mA, constant current discharge (1.00C, 2600mA) until the voltage is less than 11V.

[0061] Get the time-varying temperature value sequence of the four batteries in the battery pack, see Figure 4 , respectively recorded as sequence 1#, sequence 2#, sequence 3# and sequence 4#. The four groups of sequences are subjected to dynamic time planning analysis in pairs to obtain the corresponding dynamic planning values ​​D(m,n). The analysis results of this embodiment are shown in Table 1.

[0062] Table 1 Battery pack temperature value sequence comparison dynamic programming value

[0063] Comparison battery 1 Comparison Battery 2 Dynamic Programming Value 1 4 43.8 2 4 51.9 1 2 71.3 1 3 408.7 3 4 423.9 2 3 600.7

[0064] It can be seen that the consistency between 1# and 4# batteries is good, the consistency between 2# and 4# and 2# and 1# batteries is average, and the consistency between 3# and 1#, 2# and 4# batteries is poor. Further analysis shows that 1# and 4# batteries can directly form a battery pack, 2# battery can enter a new round of screening, and the consistency difference between 3# battery and other batteries is too large. Combined with the analysis of the temperature change sequence diagram, the heat generation of 3# battery is relatively serious, which proves that the capacity loss is large and can enter the stage of cascade utilization or material recovery.

[0065] Embodiment 2: In the second aspect, as Figure 5 As shown, in order to achieve the above purpose, the present invention discloses a lithium ion battery consistency screening system based on infrared thermal imaging technology, comprising:

[0066] The battery arrangement module 11 is used to arrange the lithium-ion batteries 2 to be tested symmetrically at their center points, connect the arranged lithium-ion batteries in series to form a lithium-ion battery pack, and place the center point of the lithium-ion battery pack and the center point of the infrared thermal imager 1 lens on the same vertical line;

[0067] The sequence analysis module 12 is used to perform charge and discharge tests on the lithium-ion battery pack, obtain the maximum temperature change sequence of each lithium-ion battery, perform pairwise similarity comparison analysis on the maximum temperature change sequence of each lithium-ion battery based on a dynamic time planning method, and output the minimum distance value between two temperature change sequences;

[0068] The consistency screening module 13 is used to compare the minimum distance value between all two temperature change sequences with a preset threshold value. The lithium-ion batteries with a minimum distance value less than the preset threshold value are judged to have good consistency, otherwise they are lithium-ion batteries with poor consistency. The lithium-ion batteries with poor consistency are re-screened and arranged until all lithium-ion batteries with good consistency are screened out.

[0069] Based on the same inventive concept, the present invention also provides a computer device, which includes: one or more processors, and a memory for storing one or more computer programs; the program includes program instructions, and the processor is used to execute the program instructions stored in the memory. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is used to implement one or more instructions, specifically for loading and executing one or more instructions in a computer storage medium to implement the above method.

[0070] It needs to be further explained that, based on the same inventive concept, the present invention also provides a computer storage medium, on which a computer program is stored, and the computer program is executed by a processor to execute the above method. The storage medium can adopt any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electrical, magnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present invention, a computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, device or device or used in combination with it.

[0071] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0072] The above shows and describes the basic principles, main features and advantages of the present disclosure. Those skilled in the art should understand that the present disclosure is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present disclosure. Without departing from the spirit and scope of the present disclosure, the present disclosure may have various changes and improvements, and these changes and improvements fall within the scope of the present disclosure to be protected.

Claims

1. A lithium-ion battery consistency screening method based on infrared thermal imaging technology, characterized in that: The method comprises the following steps: Arrange the lithium-ion batteries to be tested symmetrically at their center points, connect the arranged lithium-ion batteries in series to form a lithium-ion battery pack, and place the center point of the lithium-ion battery pack and the center point of the infrared thermal imager lens on the same vertical line; Perform charge and discharge tests on the lithium-ion battery pack to obtain the maximum temperature change sequence of each lithium-ion battery, perform pairwise similarity comparison analysis on the maximum temperature change sequence of each lithium-ion battery based on the dynamic time planning method, and output the minimum distance value between two temperature change sequences; The minimum distance value between all two temperature change sequences is compared with a preset threshold value. Lithium-ion batteries with a minimum distance value less than the preset threshold value are judged to have good consistency, otherwise they are lithium-ion batteries with poor consistency. The lithium-ion batteries with poor consistency are re-screened and rearranged until all lithium-ion batteries with good consistency are screened out.

2. The lithium-ion battery consistency screening method based on infrared thermal imaging technology according to claim 1, characterized in that: The process of placing the center point of the lithium-ion battery pack and the center point of the infrared thermal imager lens on the same vertical line: Attach thermal tape to the top of each lithium-ion battery facing the infrared thermal imager, point the infrared thermal imager lens downward, and place the lithium-ion battery pack at a preset distance below the infrared thermal imager so that the center point of the lithium-ion battery pack and the center point of the infrared thermal imager lens are in a vertical line.

3. The lithium-ion battery consistency screening method based on infrared thermal imaging technology according to claim 2, characterized in that: The material of the thermal conductive tape is acrylic pressure-sensitive adhesive, which removes the reflective interference caused by the smooth surfaces of the positive and negative electrodes of the lithium-ion battery in the infrared thermal imaging test.

4. The lithium-ion battery consistency screening method based on infrared thermal imaging technology according to claim 3 is characterized in that: The infrared thermal imager collects infrared temperature data every 30 seconds, and the emissivity is set to 0.

90.

5. The method for screening consistency of lithium-ion batteries based on infrared thermal imaging technology according to claim 1, characterized in that: The process of charging and discharging the lithium-ion battery pack is as follows: Connect the lithium-ion battery pack to the charge and discharge tester, and connect the charge and discharge tester to the computer to set the following charge and discharge parameters: constant current discharge 1.00C until the voltage is less than the discharge cut-off voltage of the single lithium-ion battery × the number of batteries in series, constant current charge 1.00C until the voltage is greater than or equal to the charge cut-off voltage of the single lithium-ion battery × the number of batteries in series, constant voltage charge, the voltage = the charge cut-off voltage of the single lithium-ion battery × the number of batteries in series, until the current is less than 0.02C, constant current discharge 1.00C until the voltage is less than the discharge cut-off voltage of the single lithium-ion battery × the number of batteries in series.

6. The lithium-ion battery consistency screening method based on infrared thermal imaging technology according to claim 1, characterized in that: The calculation process of performing pairwise similarity comparison analysis on the maximum temperature change sequence of each lithium-ion battery based on the dynamic time planning method is as follows: For two time-varying temperature sequence vectors X(i), i = 1, 2, ..., m and Y(j), j = 1, 2, ..., n, a distance table is constructed using the distance function D(i, j), which is defined as follows: Finally, when i=m, j=n, D(m,n) is the minimum distance value between two temperature change sequences.

7. The lithium-ion battery consistency screening method based on infrared thermal imaging technology according to claim 6, characterized in that: The dynamic time planning method processes two temperature change sequences with the same arrangement but different test times: for the case where m≠n exists.

8. Lithium-ion battery consistency screening system based on infrared thermal imaging technology, characterized in that: include: The battery arrangement module is used to arrange the lithium-ion batteries to be tested symmetrically at their center points, connect the arranged lithium-ion batteries in series to form a lithium-ion battery pack, and place the center point of the lithium-ion battery pack and the center point of the infrared thermal imager lens on the same vertical line; A sequence analysis module is used to perform charge and discharge tests on lithium-ion battery packs, obtain the highest temperature change sequence of each lithium-ion battery, perform pairwise similarity comparison analysis on the highest temperature change sequence of each lithium-ion battery based on a dynamic time planning method, and output the minimum distance value between two temperature change sequences; The consistency screening module is used to compare the minimum distance value between all two temperature change sequences with a preset threshold value. Lithium-ion batteries with a minimum distance value less than the preset threshold value are judged to have good consistency, otherwise they are lithium-ion batteries with poor consistency. The lithium-ion batteries with poor consistency are re-screened and arranged until all lithium-ion batteries with good consistency are screened out.

9. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that: The memory stores a computer program that can be run on the processor. When the processor loads and executes the computer program, the lithium-ion battery consistency screening method based on infrared thermal imaging technology described in any one of claims 1 to 7 is adopted.

10. A computer-readable storage medium having a computer program stored therein, characterized in that: When the computer program is loaded and executed by the processor, the lithium-ion battery consistency screening method based on infrared thermal imaging technology described in any one of claims 1 to 7 is adopted.

Images