KR20220149019A - A System for Investigating a Total Electrode Condition of a Battery - Google Patents

Abstract

The present invention relates to a system for inspecting a total electrode condition in a battery. The inspection system includes: a battery supply module (11) consecutively supplied with batteries for inspection; a two-dimensional inspection module (12) obtaining a two-dimensional X-ray image of the supplied batteries; a three-dimensional inspection subject determination module (14) determining a three-dimensional inspection subject according to an inspection result by the two-dimensional inspection module (12); a three-dimensional inspection module (15) obtaining a three-dimensional X-ray image of a battery determined as a three-dimensional inspection target; and an inspection determination module (16) determining whether the batteries transferred from the two-dimensional inspection module (12) and the three-dimensional inspection module (15) is normal or defective, wherein the three-dimensional inspection modules (15) is connected with the two-dimensional inspection module (12) through a battery transfer path to perform the inspection on the batteries transferred from the two-dimensional inspection module (12) in accordance with predetermined criteria. Therefore, the inspection system can be applied to various types of battery inspections.

Description

A System for Investigating a Total Electrode Condition of a Battery

The present invention relates to an internal whole electrode condition inspection system, and more particularly, to a battery internal whole electrode condition inspection system for inspecting the state of electrodes aligned inside a battery so that inspection errors can be reduced.

The X-ray inspection method corresponding to the non-destructive inspection has the advantage that it is possible to inspect the interior including the exterior without damage to the article. The X-ray inspection method has the advantage of being able to investigate the internal defects of the inspection object, but has a disadvantage that inspection equipment is complicated and the inspection must be performed in a shielding structure. Therefore, it is necessary to make the inspection in a structure that can be made efficiently. Various techniques related to X-ray inspection are known in the art, and for example, Patent Registration No. 10-0978054 discloses a battery X-ray inspection apparatus in which an inspection object can be rotated at various angles. In addition, Patent Publication No. 10-2019-0013014 discloses an X-ray inspection apparatus capable of inspecting internal defects and junctions. The battery for an electric vehicle may have a cylindrical structure or a pouch-type structure, and electrodes may be disposed in a jelly roll structure or a pouch structure inside each battery type. Such an internal electrode arrangement structure may be inspected by an X-ray inspection apparatus, and may be inspected by a 2D inspection or a 3D inspection method. In the case of inspection by the 2D inspection method, it is possible to inspect all the electrodes inside the battery, but it has a disadvantage in that the false defect rate is high. On the other hand, in the case of the 3D inspection method, the false defect rate can be lowered to be below a certain level such as 0.05%, for example, but it has a disadvantage that the inspection takes a lot of time. Therefore, it is necessary to develop an inspection method capable of reducing the false defect rate to a predetermined level while shortening the inspection time, but the prior art does not disclose such a technique.

The present invention is to solve the problems of the prior art and has the following objects.

Prior Art 1: Patent Registration No. 10-0978054 (Jarvis Co., Ltd., 2010.08.25. Announcement) Battery X-ray inspection device Prior art 2: Patent Publication No. 10-2019-0013014 (Jarvis Co., Ltd., published on Feb. 11, 2019) X-ray inspection device capable of inspecting internal defects and junctions

SUMMARY OF THE INVENTION It is an object of the present invention to provide a system for inspecting the state of all electrodes inside a battery capable of maintaining a false defect rate at a predetermined level while reducing an inspection time.

According to a suitable embodiment of the present invention, the internal whole electrode state inspection system includes a battery supply module to which a battery for inspection is continuously supplied; a 2D inspection module for acquiring a 2D X-ray image of the supplied battery; a 3D inspection target determining module configured to determine a 3D inspection target according to an inspection result by the 2D inspection module; a 3D inspection module for acquiring a 3D X-ray image of a battery determined as a 3D inspection target; and an inspection determination module for determining whether the battery transferred from the 2D inspection module and the 3D inspection module is normal or defective, wherein the 3D inspection module is connected to the 2D inspection module by a battery transfer path and is based on a predetermined criterion in the 2D inspection module Inspect the transferred batteries according to

According to another suitable embodiment of the present invention, the 3D inspection module 15 is installed in the inspection path extending from the 2D inspection module.

According to another suitable embodiment of the present invention, at least two 2D X-ray images according to different X-ray irradiation directions for one reference direction of each battery are obtained by the 2D inspection module.

According to another suitable embodiment of the present invention, at least two 2D X-ray images according to different reference points are acquired for each battery by the 2D inspection module 12 .

According to another suitable embodiment of the present invention, one X-ray image for a plurality of batteries is acquired by the 2D inspection module or the 3D inspection module, and the plurality of batteries are aligned in different directions.

According to another suitable embodiment of the present invention, the ratio of the objects to be inspected by the 3D inspection module is determined by the predetermined false defect ratio.

The system for inspecting the state of all electrodes inside a battery according to the present invention reduces the inspection time by a hybrid inspection structure in which a 2D inspection structure and a 3D inspection structure are combined, and simultaneously lowers the falsetto ratio to a predetermined level. The inspection system according to the present invention can be applied to various types of battery inspection, and can be advantageously applied to battery inspection for electric vehicles.

1, 2A and 2B show an embodiment of a system for inspecting the state of all electrodes inside a battery according to the present invention.
3 and 4 are diagrams illustrating an embodiment of a battery test method in the test system according to the present invention.
5A and 5B show an embodiment of a process in which a battery is inspected by the inspection system according to the present invention.
6 illustrates an embodiment of a battery tested by the inspection system according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the accompanying drawings, but the embodiments are for a clear understanding of the present invention, and the present invention is not limited thereto. In the following description, components having the same reference numerals in different drawings have similar functions, so unless necessary for the understanding of the invention, the description will not be repeated and well-known components will be briefly described or omitted, but the present invention It should not be construed as being excluded from the embodiment of

1, 2A and 2B show an embodiment of a system for inspecting the state of all electrodes inside a battery according to the present invention.

Referring to FIG. 1, the battery internal entire electrode state inspection system includes a battery supply module 11 to which a battery for inspection is continuously supplied; 2D inspection module 12 for acquiring a 2D X-ray image of the supplied battery; a 3D inspection target determination module 14 that determines a 3D inspection target according to the inspection result by the 2D inspection module 12; 3D inspection module 15 for acquiring a 3D X-ray image of the battery determined as a 3D inspection target; and an inspection determination module 16 that determines whether the battery transferred from the 2D inspection module 12 and the 3D inspection module 15 is normal or defective, wherein the 3D inspection module 15 includes the 2D inspection module 12 and the battery transport path, and the 2D inspection module 12 inspects the transported battery according to a predetermined criterion.

The supply module 11 may include a conveying means such as a conveyor, and various types of batteries such as a cylindrical battery or a pouch type battery may be continuously conveyed along the supply path 211 . A plurality of batteries may be continuously transferred to the 2D inspection module 12 along the supply path 211 , and the 2D inspection module 12 includes the first X-ray inspection module 21 . The first X-ray inspection module 21 may include at least one X-ray tube and a detector, and a 2D X-ray image corresponding to at least one flat image for each battery may be obtained. An X-ray image of a predetermined portion of the battery moving along the rotation table may be obtained by the first X-ray inspection module 21 . One or more X-ray tubes and detectors may be disposed, for example, two X-ray tubes and two detectors may be disposed at different positions on the rotary table. In addition, X-ray images for different parts of the battery or different directions of the battery may be obtained by different X-ray tubes and detectors. And it can be determined whether each battery is defective from the 2D X-ray image obtained in this way. The obtained 2D image may be transmitted to the inspection result classification module 13 , and the inspection result classification module 13 may classify the batteries into three groups, for example, according to the inspection results of each battery. For example, the test result classification module 13 may classify each battery into three classification groups, such as normal, defective, and undetermined. In addition, the transport path of the battery may be determined by the path setting module 22 according to the inspection result of the inspection result classification module 13 . The route setting module 22 may have a function of determining a transfer time while determining a transfer path of each battery. The battery determined to be normal by the path setting module 22 may be transferred to the discharge setting module 25 along the normal induction path 222 . In contrast, at least a portion of the battery determined to be defective and at least a portion determined to be undeterminable may be moved along the secondary inspection path 221 to the 3D inspection module 15 . It may be determined whether a 3D X-ray image or a CT image should be obtained by the second X-ray examination module) by the 3D examination target determination module 14 for the battery determined to be defective or determined to be undeterminable. For example, if the defect state is clear from the 2D image, the 3D image may not be acquired and may be re-inspected or discharged as a defect. In the case of a battery determined to be undetermined, a 3D image may be acquired or it may be determined to be re-inspected. The determination of whether to acquire the 3D image by the 3D inspection target determination module 14 may be determined according to the location of the defect occurrence in the battery, the form of the defect occurrence, or the state of the acquired 2D image.

If it is determined by the 3D inspection object determination module 14 that a 3D image is to be acquired, the battery may be transferred to the second X-ray inspection module 23 . The second X-ray inspection module 23 may include a rotation stage capable of rotating a battery and an irradiation position adjusting means capable of adjusting the direction in which the X-rays are irradiated from the X-ray tube. The battery located on the rotation stage may be rotated at various angles, and X-rays may be irradiated at various angles by the irradiation position adjusting means. Accordingly, a plurality of X-ray images in different directions may be obtained, and the plurality of X-ray images may become a 3D X-ray image or a CT image. In addition, whether the battery is defective may be determined based on the obtained 3D image, and the tested battery may be transferred to the test determination module 16 through the test completion path 231 . The test determination module 16 may have a function of determining a final test result for each battery tested by the first and second X-ray modules. Each battery may be determined as either normal, defective or retested by the inspection determination module 16 and may be moved to the discharge module 17 together with the determination result. The discharge module 17 may include a discharge path setting module 25 . The discharge path setting module 25 may have a function of guiding each battery to any one of three discharge paths. Specifically, the discharge path setting module 25 may transfer each battery to a subsequent process step of the battery through the normal induction path 251 . The discharge path setting module 25 may transfer each battery to the defective collection module 24 . Alternatively, the discharge path setting module 25 may transfer each battery to the retest path 26 . The discharge path setting module 25 may include various path setting means capable of guiding the battery to different discharge paths, and the present invention is not limited thereby.

Referring to FIG. 2B , the 3D inspection module 15 is connected to the 2D inspection module 12 by a battery transfer path, and the 2D inspection module 12 inspects the transferred battery according to a predetermined standard. The supply path 211 may be a conveyor structure capable of transporting a carrier loaded with batteries, and the supply path 211 may be connected to a process line 211a installed for manufacturing the battery. The battery transferred through the process line 211a may be loaded on a carrier and moved along the supply path 211 to be introduced into the first inspection module 21 . The first inspection module 21 for acquiring the 2D X-ray image may have a closed structure, and the supply path 211 extends into the first inspection module 211 and the loading module 212 has an engaging rotation block structure. ) to deliver the carrier. The loading module 212 may deliver the carrier to the rotary table 213 that rotates in engagement with the loading module 212 while having a rotary rotary structure. The carrier may be rotated by being fixed to a fixed block formed along the circumferential surface of the rotating table 213 . One or more X-ray tubes (T11, T12) are disposed on the outside of the rotary table 213, and a detector for obtaining an X-ray image from each X-ray tube (T11, T12) is disposed inside the rotary table 213 can be A plurality of X-ray tubes T11 and T12 may be disposed, and X-ray images for different parts or different directions of the battery may be obtained. A 2D X-ray image of all batteries supplied by the first inspection module 21 may be acquired, and the inspection-completed battery has a path determined by the path setting module 22 including two rotation blocks that are interlocked and rotated can be transported along The battery determined to be normal may be guided along the normal induction path 222 and transferred to the primary normal discharge path 251a. In contrast, the battery determined to be defective or impossible to determine may be moved along the secondary inspection path 221 . The secondary inspection path 221 may be connected to the second inspection module 23 , and the normal induction path 222 may extend to the outside of the second inspection module 23 and be connected to the primary normal discharge path 251a. . The second inspection module 23 may have a closed structure, and the battery loaded in the carrier that is put into the inside of the second inspection module 23 is stored inside the second inspection module 23 by the feeding control module 27 . can be put into The feeding control module 27 may have a function of adjusting the input speed of the battery according to the state in which the inspection is performed inside the second inspection module 23 while maintaining the transferred battery in a standby state. The path selection module 28 is disposed inside the second inspection module 23 , and each battery may be moved to the 3D X-ray image acquisition device by the path selection module 28 or guided to the re-inspection path 26 . . In order to obtain a 3D X-ray image, a plurality of X-ray tubes T21 to T2N may be disposed inside the second examination module 23, and the plurality of X-ray tubes T21 to T2N may be of the second examination module 23. It may be disposed linearly along the transport path of the battery or carrier disposed therein. The battery may be loaded on the rotation stages ST1 to STN, and the rotation stages ST1 to STN may have a rotatable structure. Detectors D1 to DN may be rotatably disposed below the rotation stages ST1 to STN. With such an inspection structure, 3D images or CT images of different parts of the battery may be obtained by the respective X-ray tubes T21 to T2N and the detectors D1 to DN. In addition, a defect may be determined based on the acquired 3D image or CT image, and the discharge path may be determined by the discharge path setting module 25 . Specifically, the battery finally determined to be defective may be transferred to the defective collection module 24 , and the battery determined to be normal may be discharged along the secondary normal discharge path 251b. Thereafter, the battery determined to be normal may be put into a subsequent processing line, and the empty carrier may be moved along the carrier conveyor 29 . The first and second inspection modules 21 and 23 may have various arrangement structures and are not limited to the presented embodiment.

3 and 4 are diagrams illustrating an embodiment of a battery test method in the test system according to the present invention.

Referring to FIG. 3 , the battery B may be a cylindrical battery, and the cylindrical battery may have an electrode structure of a jelly roll structure. Specifically, the positive electrode 32 and the negative electrode 34 may be insulated from each other by the insulating plate 33 and wound around the central axis 35 . In addition, the electrodes 32 and 34 may be disposed inside the case 31 to be protected. In order to inspect the battery B having such a structure, the X-rays X11 and X12 are irradiated to the battery B by the X-ray tube F to obtain an X-ray image. The acquired X-ray image may be a 2D image or an image for forming a 3D image, and whether the battery B is defective may be determined based on the X-ray image. The arrangement state of the anode 32 and the cathode 34 should be confirmed from the acquired X-ray image, and the X-ray image may be formed by X-ray transmittance. Therefore, the arrangement state of the anode 32 or the cathode 33 at the boundary portion of the case 31 may be affected by the transmittance of the case 31 . Accordingly, there is a problem in that it is difficult to clearly determine the arrangement state of the boundary portion. In order to solve this problem, the X-rays X21 to X42 are irradiated in different directions with respect to the reference direction of the battery B, and X-ray images of the battery B in different directions may be obtained. Specifically, each battery B may be moved along an inspection path RP formed on the rotary table for inspection. In addition, the reference directions RL of the battery B at different positions P1 , P2 , and P3 may be different from each other at the center of the rotary table. X-ray images in different directions may be acquired by one or more X-ray tubes at different locations (P1, P2, P3), and thereby at a location corresponding to the boundary at one location (for example, P1). A clear electrode image can be obtained at a different location (eg P2 or P2) for In addition, it is possible to test all the electrodes of the battery by such an inspection method and to reduce inspection errors. In addition, establishment of an inspection path by the inspection determination module 16 may be facilitated as described above.

The battery B may have a pouch or stack structure, and as shown in FIG. 4 , the positive electrode plate 41 and the negative electrode plate 42 may be insulated from each other while forming a layer while forming a plate shape, respectively. In such a battery structure, the battery inspection may include an arrangement state inspection of the positive electrode plate 41 and the negative electrode plate 42 . X-rays X51, X52, X61, and X62 may be irradiated from the X-ray tube T1 in order to inspect the arrangement of the positive electrode plate 41 and the negative electrode plate 42 to obtain an X-ray image. The edge distances D11 and D12 of the positive electrode plate 41 and the negative electrode plate 42 are obtained from the acquired X-ray image, and the arrangement state between the positive electrode plate 41 and the negative electrode plate 42 can be inspected based on this. have. However, as shown in the middle part of FIG. 4 , when the negative electrode plate 42 is arranged to be inclined with respect to the positive electrode plate 41, the inclined edge lengths D21 and D22) are the edge lengths D11 and D12 depending on the inclined shape. can be the same as As a result, there is a problem in that a defective battery may be determined as a normal battery. In order to solve this problem, as shown in the middle part of FIG. 4 , the X-rays X71, X72, X81, X82 are irradiated in different directions of the battery B by one X-ray tube T1 so as to be irradiated in different directions. An X-ray image of may be obtained. Alternatively, two X-ray images may be obtained by at least two X-ray tubes T1 and T2 positioned in different directions. And the edge distances D11 and D12 are calculated from the two X-ray images, so that the arrangement of the electrode plates 41 and 42 can be confirmed.

In the battery inspection process, a plurality of batteries B1 to BN must be inspected, and it is necessary to shorten the inspection time in order to increase inspection efficiency. To this end, X-ray images for a plurality of batteries B1 to BN may be acquired by one X-ray tube T3. For example, a plurality of batteries B1 to BN are arranged to be inclined at different angles with respect to a reference direction, and a plurality of batteries B1 to BN by X-rays X91 to X94 irradiated from one X-ray tube T3. ), one X-ray image can be obtained. In addition, the alignment state of the electrode plates 41 and 42 of the plurality of batteries B1 to BN may be inspected from one image. The X-ray tube T1 may irradiate the X-rays X91 to X94 in various positions or directions according to the structure or inspection site of the batteries B1 to BN. The X-ray images for inspection of the batteries B1 to BN may be acquired in various ways and are not limited to the presented embodiment.

5A and 5B show an embodiment of a process in which a battery is inspected by the inspection system according to the present invention.

5A and 5B, the battery inspection method includes the steps of continuously transferring the battery (P51); A step (P52) of obtaining a 2D X-ray image for each battery to be a primary inspection; Classifying the examination results based on the X-ray image obtained in the first examination (P53); Determining whether to obtain a 3D X-ray image according to the classification result (P54); Determining whether each battery is normal according to the 2D test result or the 3D test result (P55); and discharging to the bad discharge path (P56) or discharged to the normal discharge path (P57) according to the determination result.

A 2D X-ray image may be obtained for all the transferred batteries (P52), and each battery may be classified based on the 2D X-ray image (P53). The resolution of the 2D X-ray image may be set in various ways, and the inspection speed or the false defect rate may be different according to the resolution. In order to secure the inspection performance, the false defect rate may be set to be, for example, 0.05% or less, and the 3D inspection object may be determined. For example, if the false false positive rate is 5% at the required inspection speed of 200 PPM (Pack Per Minute) by the 2D X-ray inspection method P52, it is difficult to satisfy the false false positive rate determined by the 2D inspection method. In this case, the battery test may be performed in parallel with the 3D test method P55 to be suitable for 0.05% corresponding to the determined false defect rate. In such an inspection structure, the 2D X-ray inspection rate becomes 190 PPM, and the 3D inspection X-ray inspection rate becomes 10 PPM, so that the overall inspection speed may be lowered. However, it allows efficient battery inspection while satisfying the false-failure ratio condition. In the inspection structure of such a hybrid structure, as described with reference to FIGS. 2 to 4 , X-ray images may be acquired in various ways in order to improve inspection efficiency. The combination of the 3D X-ray inspection method may be performed in various ways and is not limited to the presented embodiment.

6 illustrates an embodiment of a battery tested by the inspection system according to the present invention.

Referring to FIG. 6 , in the case of the 2D X-ray image on the left, an image in which the case and the electrode are not clearly distinguished may be generated in the boundary portions EP1 and EP2. In such a case, it is difficult to determine whether a product is defective, and a false false positive in which a product that is substantially normal is determined to be defective may occur. In contrast, in the case of the 3D X-ray image on the right side, a clear image of the boundary portions EP1 and EP2 of the battery B may be obtained, and thus false false positives do not occur. The inspection system according to the present invention can reduce the false defect rate generated from such an X-ray image. The false false positive caused by the 2D X-ray image may occur due to various causes in various regions and is not limited to the presented embodiment.

Although the present invention has been described in detail with reference to the presented embodiments, those skilled in the art can make various modifications and modified inventions without departing from the technical spirit of the present invention with reference to the presented embodiments. . The present invention is not limited by such variations and modifications, but only by the claims appended hereto.

11: Battery supply module 12: 2D inspection module
14: 3D inspection target determination module 15: 3D inspection module
16: inspection determination module 21: first X-ray inspection module
22: path setting module 23: second x-ray inspection module
25: emission setting module 28: path selection module
211: supply path 221: inspection path

Claims (6)

a battery supply module 11 to which batteries for inspection are continuously supplied;
2D inspection module 12 for acquiring a 2D X-ray image of the supplied battery;
a 3D inspection target determination module 14 that determines a 3D inspection target according to the inspection result by the 2D inspection module 12;
3D inspection module 15 for acquiring a 3D X-ray image of the battery determined as a 3D inspection target; and
2D inspection module 12 and an inspection determination module 16 for determining whether the battery transferred from the 3D inspection module 15 is normal or defective,
The 3D inspection module 15 is connected to the 2D inspection module 12 by a battery transport path, and the 2D inspection module 12 performs the inspection on the transferred battery according to a predetermined standard, all electrodes inside the battery health check system. The system according to claim 1, wherein the 3D inspection module (15) is installed in the inspection path (221) extending from the 2D inspection module (12). The system according to claim 1, wherein at least two 2D X-ray images according to different X-ray irradiation directions for one reference direction of each battery are acquired by the 2D inspection module (12). . The system according to claim 1, wherein at least two 2D X-ray images according to different reference points are acquired for each battery by the 2D inspection module (12). The battery according to claim 1, wherein one X-ray image for a plurality of batteries is obtained by the 2D inspection module (12) or the 3D inspection module (15), and the plurality of batteries are aligned in different directions. Electrode condition inspection system. The system according to claim 1, wherein the ratio of the inspection target by the 3D inspection module (15) is determined by a predetermined false defect ratio.

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