Nspection system for electrode sheet and nspection method for electrode sheet using the same

Abstract

The present disclosure relates to an electrode sheet inspection system comprising: a conveying unit for conveying an electrode sheet having an insulating coating portion; a measuring unit for measuring the insulating coating portion of the electrode sheet; and a control unit for analyzing an image transmitted from the measuring unit; wherein the measuring unit comprises: first and second illumination units provided on the upper side of the electrode sheet to irradiate light onto the electrode sheet; a third illumination unit provided adjacent to the side of the electrode sheet to irradiate light onto the electrode sheet; and a shooting unit provided on the upper side of the electrode sheet to photograph the electrode sheet and transmit the image to the control unit.

Description

Technology Field

[0001] The present disclosure relates to an electrode sheet inspection system and an electrode sheet inspection method using the same. Background Technology

[0002] Unlike primary batteries, secondary batteries are rechargeable, and demand is gradually increasing due to their potential for miniaturization and high capacity. These secondary batteries are manufactured in the form of single battery cells packaged into a pack or battery packs connecting dozens of cells, and are widely used as power sources for mobile phones, laptops, and electric vehicle motors.

[0003] Various studies are being conducted to manufacture these battery cells with uniform quality while simultaneously achieving high productivity. In particular, in the manufacturing process of battery cells, electrode sheets used as positive or negative electrodes are mainly processed in-line, and it is necessary to reduce inefficiencies caused by process stoppages due to defect detection and handling of electrode sheets during the in-line process, as well as maintenance and repair. The problem to be solved

[0004] One embodiment of the present disclosure can provide an electrode sheet inspection system capable of improving the process efficiency of a battery cell and an electrode sheet inspection method using the same.

[0005] In addition, one embodiment of the present disclosure can provide an electrode sheet inspection system capable of efficiently handling defects in an electrode sheet in which an inline process is performed, and an electrode sheet inspection method using the same.

[0006] Meanwhile, the present disclosure can be widely applied in the field of green technology, such as electric vehicles, battery charging stations, energy storage systems (ESS), and other photovoltaic and wind power generation that utilize batteries. In addition, the present disclosure can be used in eco-friendly mobility, including electric vehicles and hybrid vehicles, to prevent climate change by suppressing air pollution and greenhouse fluid emissions. means of solving the problem

[0007] One embodiment of the present disclosure includes an electrode sheet inspection system and an electrode sheet inspection method using the same.

[0008] In one embodiment, the electrode sheet inspection system comprises: a conveying unit for conveying an electrode sheet having an insulating coating portion; a measuring unit for measuring the insulating coating portion of the electrode sheet; and a control unit for analyzing an image transmitted from the measuring unit. The measuring unit may include: first and second illumination units provided on the upper side of the electrode sheet to irradiate light onto the electrode sheet; a third illumination unit provided adjacent to the side of the electrode sheet to irradiate light onto the electrode sheet; and a shooting unit provided on the upper side of the electrode sheet to photograph the electrode sheet and transmit the image to the control unit.

[0009] In one embodiment, the first lighting unit may include a white LED having a wavelength of 380 nm to 760 nm, and the second and third lighting units may each include a blue LED having a wavelength of 350 nm to 495 nm.

[0010] In one embodiment, the first lighting unit is spaced apart from the electrode sheet by a first distance of 90 mm to 1100 mm and irradiates the light at a first angle of 70° to 95° with respect to the electrode sheet, the second lighting unit is spaced apart from the electrode sheet by a second distance of 90 mm to 1100 mm and irradiates the light at a second angle of 75° to 95° with respect to the electrode sheet, and the third lighting unit is spaced apart from the electrode sheet by a third distance of 70 mm to 130 mm and irradiates the light at a third angle of 10° to 30° with respect to the electrode sheet.

[0011] In one embodiment, the imaging unit is provided at a fourth angle of 40° to 65° with respect to the electrode sheet, and can acquire an image by light irradiated by each of the first to third illumination units.

[0012] In one embodiment, regarding the transfer path of the electrode sheet, an electrode sheet meandering detection unit provided at the front end of the measuring unit may be further included.

[0013] In one embodiment, the electrode sheet meandering detection unit includes a detection sensor that measures the transport path of the electrode sheet, and when the transport path measured by the detection sensor deviates by a first distance from a pre-entered range, it is transmitted to the control unit, and the control unit can adjust the position of one or more of the first to third lighting units and the shooting unit according to the information transmitted from the electrode sheet meandering detection unit.

[0014] In one embodiment, the control unit can analyze the image transmitted from the measuring unit to measure either the thickness or the width of the insulating coating unit and determine whether it is defective.

[0015] In one embodiment, the transfer path of the electrode sheet may further include a defect location indicator provided at the rear end of the measuring unit.

[0016] In one embodiment, when the control unit determines that either the thickness or the width of the insulating coating part is defective, the control unit transmits to the defect location indicator, the defect location indicator includes an ink marking device, and the defect location indicator can mark on the electrode sheet using the ink marking device.

[0017] In one embodiment, the electrode sheet comprises: a metal sheet; a coating portion formed on at least one of one side and the other side of the metal sheet; a non-coating portion where the metal sheet is exposed and the coating portion is not provided; and an insulating coating portion provided to cover at least a portion of the coating portion at the boundary between the coating portion and the non-coating portion, and the electrode sheet inspection system can determine whether the insulating coating portion is defective.

[0018] In one embodiment, the electrode sheet inspection method comprises: an insulating coating part measurement step in which an insulating coating part is provided and the electrode sheet is transported, and an image is obtained by measuring the insulating coating part of the electrode sheet using a measuring unit; and an insulating coating part determination step in which the image is analyzed to determine whether the insulating coating part is defective; wherein the measuring unit may include: first and second lighting units provided on the upper side of the electrode sheet to irradiate light onto the electrode sheet; a third lighting unit provided adjacent to the side of the electrode sheet to irradiate light onto the electrode sheet; and a shooting unit provided on the upper side of the electrode sheet to photograph the electrode sheet and transmit the image to the control unit.

[0019] In one embodiment, the imaging unit is provided at an angle of 40° to 65° with respect to the electrode sheet, and can acquire an image by light irradiated by each of the first to third illumination units.

[0020] In one embodiment, prior to the insulation coating part measurement step, the method further includes an electrode sheet path detection step for measuring the transfer path of the electrode sheet, wherein the electrode sheet path detection step measures the transfer path of the electrode sheet by means of a detection sensor, and if the transfer path measured by the detection sensor deviates by a first distance from a pre-entered range, it is transmitted to a control unit, and the control unit can adjust the position of one or more of the first to third lighting units and the shooting unit.

[0021] In one embodiment, after the insulating coating part determination step, a defect location indication step for indicating the bonding position of the electrode sheet is further included, and the defect location indication step may indicate on the electrode sheet when the insulating coating part is determined to be defective in the insulating coating part determination step.

[0022] In one embodiment, the method further includes an electrode sheet path detection step for measuring the transport path of the electrode sheet before the insulation coating part measurement step; and a defect location indication step for indicating the bonding position of the electrode sheet after the insulation coating part determination step; wherein the electrode sheet path detection step, the insulation coating part measurement step, the insulation coating part determination step, and the defect location indication step can be performed in-line. Effects of the invention

[0023] According to one embodiment of the present disclosure, an electrode sheet inspection system capable of improving the process efficiency of a battery cell and an electrode sheet inspection method using the same may be provided.

[0024] In addition, according to one embodiment of the present disclosure, an electrode sheet inspection system capable of efficiently processing defects in an electrode sheet in which an inline process is performed, and an electrode sheet inspection method using the same may be provided. Brief explanation of the drawing

[0025] FIG. 1 is a schematic diagram illustrating an electrode sheet inspection system according to one embodiment of the present disclosure. Figure 2 is a side view illustrating the inspection of an electrode sheet using the electrode sheet inspection system of Figure 1. Figure 3 is a front view illustrating the inspection of an electrode sheet using the electrode sheet inspection system of Figure 1. FIG. 4 is a drawing showing an electrode sheet according to one embodiment of the present disclosure. Figure 5 is a diagram illustrating the inspection of the insulating coating portion of an electrode sheet. Figure 6 is a diagram for explaining the operation of the third lighting unit of Figure 1. FIG. 7 is a schematic diagram showing an electrode sheet inspection system according to another embodiment of the present disclosure. FIG. 8 is a flowchart illustrating an electrode sheet inspection method according to another embodiment of the present disclosure. Specific details for implementing the invention

[0026] Structural or functional descriptions of the embodiments disclosed in this specification or application are provided merely for the purpose of explaining embodiments according to the technical concept of this disclosure. Embodiments according to the technical concept of this disclosure may be implemented in various forms other than those disclosed in this specification or application, and the technical concept of this disclosure is not to be interpreted as being limited to the embodiments described in this specification or application.

[0028] FIG. 1 is a schematic diagram illustrating an electrode sheet inspection system according to one embodiment of the present disclosure. FIG. 2 is a side view illustrating the inspection of an electrode sheet using the electrode sheet inspection system of FIG. 1. FIG. 3 is a front view illustrating the inspection of an electrode sheet using the electrode sheet inspection system of FIG. 1. FIG. 4 is a diagram showing an electrode sheet according to one embodiment of the present disclosure. FIG. 5 is a diagram for explaining the inspection of the insulating coating portion of the electrode sheet. FIG. 6 is a diagram for explaining the operation of the third lighting unit of FIG. 1.

[0029] Referring to FIG. 1, an electrode sheet inspection system (100) according to one embodiment of the present disclosure may include: a conveying unit (110) for conveying an electrode sheet (10) having an insulating coating portion; a measuring unit (120) for measuring the insulating coating portion of the electrode sheet (10); and a control unit (130) for analyzing an image transmitted from the measuring unit (120). Additionally, the measuring unit (120) may include: first and second illumination units (121, 122) provided on the upper side of the electrode sheet (10) to irradiate light onto the electrode sheet (10); a third illumination unit (123) provided adjacent to the side of the electrode sheet (10) to irradiate light onto the electrode sheet (10); and a shooting unit (124) provided on the upper side of the electrode sheet (10) to photograph the electrode sheet (10) and transmit the image to the control unit (130).

[0030] Typically, during the manufacturing process of secondary batteries, electrode sheets, such as positive and negative electrodes, are transported, and defects in the electrode sheets are measured and detected during this process. At this time, the electrode sheets are transported at a predetermined speed via a roll-to-roll process; however, reducing the transport speed to ensure accurate defect detection during the process of photographing and detecting defects can lower productivity. Furthermore, there was a disadvantage in that defect detection was difficult due to light reflection caused by the fact that the materials constituting the electrode sheets consist of metal and positive or negative active materials.

[0031] On the other hand, the electrode sheet inspection system (100) according to the embodiment of the present disclosure can effectively detect defects in an electrode sheet being transported at a predetermined speed by utilizing a novel configuration. In addition, the electrode sheet inspection system (100) according to the embodiment of the present disclosure can effectively detect defects in an insulating coating portion that occupies a very small area of ​​the electrode sheet (10), regardless of the slope, size, and shape of the insulating coating portion. The electrode sheet inspection system (100) according to the embodiment of the present disclosure can effectively and accurately detect defects in the insulating coating portion of the electrode sheet, thereby reducing unnecessary electrode sheet loss and effectively improving productivity.

[0032] The above transfer unit (110) can transfer the electrode sheet (10). The electrode sheet (10) may be provided in the form of a sheet extended in one direction. The above transfer unit (110) is for transferring the electrode sheet and may include a roll-to-roll device or a conveyor device, etc. The above transfer unit (110) can transfer the electrode sheet at a first speed.

[0033] The above measuring unit (120) can measure the electrode sheet (10) being transported at the first speed by the above transport unit (110). Specifically, the above measuring unit (120) can measure the insulating coating portion of the electrode sheet (10).

[0034] The above measuring unit (120) may include first to third lighting units (121, 122, 123) and a shooting unit (124). The first to third lighting units (121, 122, 123) can irradiate light by controlling it at various angles with respect to the electrode sheet (10), and the shooting unit (124) can generate an image by shooting the electrode sheet (10) using the light irradiated and reflected from the electrode sheet (10).

[0035] Referring to FIGS. 2 to 4, the first lighting unit (121) and the second lighting unit (122) are provided on the upper side of the electrode sheet (10) to irradiate light onto the electrode sheet (10). The first and second lighting units (121, 122) are provided with different wavelengths and can irradiate light onto the electrode sheet (10) at different angles. The third lighting unit (123) is provided adjacent to the side of the electrode sheet (10) to irradiate light onto the electrode sheet (10). Additionally, the first and second lighting units (121, 122) provided on the upper side of the electrode sheet (10) may be provided with different wavelengths.

[0036] As described above, the electrode sheet inspection system (100) according to the embodiment of the present disclosure can more accurately measure the thickness, width, and length of the insulating coating portion (15) of the electrode sheet (10) by varying the position at which light is irradiated onto the electrode sheet (10) and varying the wavelength range according to each position, so that the light applied by the first to third illumination units (121, 122, 123) interacts with each other.

[0037] The electrode sheet (10) may include a metal sheet (11) made of metal or the like, a coating portion (12) formed on at least one of one side and the other side of the metal sheet (11), and a non-coating portion that is a part where the metal sheet is exposed and the coating portion (12) is not provided. The coating portion (12) may include an area on the metal sheet (11) where an active material, such as a positive electrode active material or a negative electrode active material, is provided, and the non-coating portion may be a part where the metal sheet (11) is exposed as is. The insulating coating portion (15) may be provided at the boundary between the coating portion (12) and the non-coating portion to cover at least a portion of the coating portion (12). The electrode sheet inspection system (100) according to the present embodiment can determine whether the insulating coating portion (15) is defective.

[0038] The coating portion (12) may be provided by preparing the active material into a slurry and coating the slurry onto the sheet (11). The slurry may contain a solvent and an active material, and may be formed by coating the slurry onto the metal sheet (11) and then drying the solvent. The slurry may be provided in a form having a predetermined viscosity, so that an edge taper phenomenon may occur during the process of forming the coating portion (12). Specifically, the end of the coating portion (12), which is the part between the coating portion (12) and the uncoated portion where the coating portion (12) starts or ends, may be provided in a slanted shape due to the drag phenomenon caused by the frictional force of the slurry with the metal sheet (11).

[0039] The insulating coating portion (15) is provided at the boundary between the coating portion (12) and the uncoated portion, so as to cover the end of the coating portion (12). At this time, the end of the coating portion (12) may be provided with an inclination at various angles depending on material characteristics such as the viscosity of the slurry and the surface contact angle of the metal sheet, and methodological characteristics such as the coating method and drying method. The insulating coating portion (15) is formed according to the shape of the inclination of the coating portion (12), and as a result, the height, thickness, and width may be affected by the inclination of the coating portion (12).

[0040] The insulating coating portion (15) may be made of an insulating material. The insulating coating portion (15) covers the end of the coating portion (12) to prevent stability problems of the secondary battery that may occur due to the detachment of the coating portion (12).

[0041] The insulating coating portion (15) may be provided with a predetermined average thickness (T) in the coating portion (12). The average thickness (T) of the insulating coating portion (15) may be 3 μm to 50 μm. If the average thickness (T) of the insulating coating portion (15) is less than 3 μm, it is difficult to coat the coating portion (12) uniformly, and defects such as the coating portion (12) being exposed may occur during the production process. In addition, if the average thickness (T) of the insulating coating portion (15) is greater than 50 μm, the thickness of the portion where the insulating coating portion (15) is provided is too thick, making it difficult to align the electrode sheet (10), etc., in the correct position during the lamination process, which causes problems. Specifically, the average thickness (T) of the insulating coating portion (15) may be 3 μm to 40 μm, or 3 μm to 30 μm, or 5 μm to 20 μm, or 5 μm to 10 μm.

[0042] The insulating coating portion (15) may be formed by connecting the end of the coating portion (12) to the uncoated portion. The width (W) of the insulating coating portion (15) may be 5 mm to 30 mm. If the width (W) of the insulating coating portion (15) is less than 5 mm, it may be difficult to stably fix the end of the coating portion (12), and thus the insulating properties may be degraded. If the width (W) of the insulating coating portion (15) is greater than 30 mm, the area in which the movement of lithium ions is restricted within the electrode sheet (10) increases, which may reduce the capacity efficiency per unit volume of the secondary battery. Specifically, the width (W) of the insulating coating portion (15) may be 3 mm to 25 mm, or 3 mm to 20 mm, or 5 mm to 15 mm, or 5 mm to 10 mm.

[0043] Conventionally, when verifying defects in such an insulating coating part, there was a problem in that it was difficult to accurately measure the thickness or width of the insulating coating part due to the degree of inclination of the end of the coating part provided at the bottom of the insulating coating part and the resulting light reflection. This will be explained in detail with reference to FIG. 5.

[0044] In the case of FIG. 5(a), when the slope of the coating portion (12) on the metal sheet (11) in the electrode sheet (10) is gentle, the insulating coating portion (15) covers along the slope of the coating portion (12), and the thickness, width, length, etc. of the insulating coating portion (15) can be confirmed by detecting the overlap of the insulating coating portion (15) using a camera or the like. Specifically, when the light irradiated by a light source is 100%, 70% of the light is reflected by the slope of the coating portion (12), and 5% of the light is reflected by the insulating coating portion (12). At this time, 10% of the light is transmitted to the camera by the coating portion (12), and 5% of the light is transmitted by the insulating coating portion (12) to form an image. The defect status of the insulating coating portion (15) can be determined by the image obtained by the camera.

[0045] On the other hand, as in the case of FIG. 5(b), when the slurry is formed to have a steep slope and the slope of the coating part (12) is steep, it is difficult to detect the overlap portion using the camera, and as a result, there is a problem in that it is difficult to check whether the insulating coating part (15) is defective. Specifically, even if the light source irradiates light at 100%, due to the slope of the coating part (12), the camera receives 90% of the light from the coating part (12) and 10% of the light from the insulating coating part (12), and since most of the information received by the camera is light reflection from the coating part (12), the visibility of the insulating coating part (15) is reduced, making it difficult to check whether the insulating coating part (12) is defective.

[0046] On the other hand, the electrode sheet inspection system (100) according to the embodiment of the present disclosure includes the imaging unit (124) together with the first to third lighting units (121, 122, 123), and the first to third lighting units (121, 122, 123) and the imaging unit (124) can effectively check whether the insulating coating part (12) is defective regardless of the degree of inclination of the coating part (12).

[0047] The first lighting unit (121) may include a white LED with a wavelength of 380 nm to 760 nm, and the second and third lighting units (122, 123) may each include a blue LED with a wavelength of 350 nm to 495 nm.

[0048] By making the first lighting unit (121) and the second lighting unit (122) provided on the upper side of the electrode sheet (10) have different wavelengths within the aforementioned range, and by applying light of a composite wavelength on the upper side of the electrode sheet (10), the visibility of the insulating coating portion (15) on the upper side of the electrode sheet (10) can be improved.

[0049] The light applied from the second lighting unit (122) is provided with a different wavelength from the light applied from the first lighting unit (121), so that a composite wavelength can be formed on the upper surface of the electrode sheet (10). Specifically, the light from the second lighting unit (122) may be provided with a lower wavelength than the light from the first lighting unit (121).

[0050] The third lighting unit (123) can apply light to the electrode sheet (10) from the side of the electrode sheet (10). If the wavelength of the third lighting unit (123) is less than 350 nm, the visibility of the insulating coating part (15) is reduced due to light reflection from the side of the electrode sheet (10), and if it is greater than 435 nm, the imaging unit (124) cannot effectively receive the light transmitted by the third lighting unit (123), which causes a problem.

[0051] The first lighting unit (121) is spaced apart from the electrode sheet (11) by a first distance (L1) of 90 mm to 1100 mm and can irradiate the light at a first angle (θ1) of 70˚ to 95˚ with respect to the electrode sheet (11).

[0052] The first lighting unit (121) is provided on the upper part of the electrode sheet (10) to inspect for defects in the coating portion (12) and the insulating coating portion (15). The first lighting unit (121) can irradiate light from the upper part of the electrode sheet (10) in a direction toward the coating portion (12) from the unlit portion. The first lighting unit (121) can check for defects in the insulating coating portion (15) and, together with the formation of defects in the coating portion (12), such as pinholes or bubbles, by changing the angle within the range of the first angle (θ1). By maintaining the first distance (L1) and the first angle (θ1), the first lighting unit (121) can improve the visibility of the coating portion (12) and the insulating coating portion (15) on the upper part of the electrode sheet (10).

[0053] The second lighting unit (122) is spaced apart from the electrode sheet (11) by a second distance (L2) of 90 mm to 1100 mm and can irradiate the light at a second angle (θ2) of 75˚ to 95˚ with respect to the electrode sheet.

[0054] The second lighting unit (122) can inspect for defects in the insulating coating portion (15) on the upper surface of the electrode sheet (10). The second lighting unit (122) can irradiate light from the coating portion (12) on the upper surface of the electrode sheet (10) in a direction toward the unlit portion. Specifically, the second lighting unit (122) is provided at the second angle (θ2) to improve the detection capability of the thickness, width, length, etc. of the insulating coating portion (15) by irradiating light. By maintaining the second distance (L2) and the second angle (θ2), the second lighting unit (122) can improve the visibility of the insulating coating portion (15) by forming a composite wavelength with the second lighting unit (122) on the upper surface of the electrode sheet (10).

[0055] The third lighting unit (123) is spaced apart from the electrode sheet (10) by a third distance (L3) of 70 mm to 130 mm, and can irradiate the light at a third angle (θ3) of 10° to 30° with respect to the electrode sheet (10).

[0056] Referring to FIG. 6, the third lighting unit (123) is spaced apart from the side of the electrode sheet (10) and can form a shadow (S) at the boundary of the insulating coating part (15).

[0057] As shown in FIG. 6(a), when the slope of the coating portion (12) formed on the metal sheet (11) of the electrode sheet (10) is steep, the third lighting unit (123) can form a shadow (S) at the part where the slope of the insulating coating portion (15) begins. Also, as shown in FIG. 6(b), when the slope of the coating portion (12) formed on the metal sheet (11) of the electrode sheet (10) is gentle, the third lighting unit (123) can form a shadow (S) at the part where the slope of the insulating coating portion (15) begins. That is, the third lighting unit (123) is provided adjacent to the side of the electrode sheet (10) and forms a shadow (S) at the part where the slope of the insulating coating portion (15) begins, thereby effectively detecting the overlapping portion of the insulating coating portion (15).

[0058] The electrode sheet inspection system (100) according to the present embodiment can effectively detect the thickness or width of the insulating coating portion (15) by controlling the arrangement, angle, and distance of the first to third lighting units (121, 122, 123) to the electrode sheet (10). In addition, by controlling the light irradiated from the first to third lighting units (121, 122, 123), each light is efficiently applied to the electrode sheet (10), and an image with improved visibility of the thickness or width of the insulating coating portion (15) can be obtained by the imaging unit (130).

[0059] The above-mentioned imaging unit (124) is provided at a fourth angle (θ4) of 40° to 65° with respect to the electrode sheet (10), and can acquire an image by light irradiated by each of the first to third illumination units (121, 122, 123). The above-mentioned imaging unit (124) can check the thickness or width of the insulating coating part (15) by the light irradiated from the first to third illumination units (121, 122, 123) and input through the light reflected from the insulating coating part (15).

[0060] The above-mentioned imaging unit (124) may include a line scan camera, but is not limited thereto. Additionally, the above-mentioned imaging unit (124) may obtain images by wavelength range, and the resolution of the above-mentioned imaging unit (124) may be less than 25 μm.

[0061] The above-mentioned shooting unit (124) can obtain an image including the insulating coating part (15). In the image, the insulating coating part (15) can be distinguished by color, brightness, saturation, etc. For example, in the image, the insulating coating part (15) can be represented as a lighter gray than the surroundings, and visibility can be improved by the shadow (S, see FIG. 6) created by the third lighting unit (123).

[0062] The above-mentioned shooting unit (124) may be provided at the above-mentioned fourth angle (θ4). By providing the shooting unit (124) at the aforementioned angle, light from the above-mentioned first to third lighting units (121, 122, 123) is efficiently received, and the visibility of the insulating coating part (15) within the image can be further improved.

[0063] The control unit (130) can determine whether there is a defect by analyzing the image transmitted from the measurement unit (120) and measuring at least one of the thickness and width of the insulating coating unit (15). The control unit (130) can acquire individual images from the first to third lighting units (121, 122, 123) using a multi-line shot, etc. Additionally, the control unit (130) can set a Sub ROI (Sub Region of Interest) and generate a profile within the ROI to extract edge portions. The control unit (130) can determine whether at least one of the thickness and width of the insulating coating unit (15) is included within a previously stored data range (OK) or exists outside the previously stored data range (NG).

[0064] The above image may be provided in various forms, such as video, images, etc., and in the control unit (130), the defect of the insulating coating unit (15) is not limited to the above description and various methods may be used.

[0065] The electrode sheet inspection system according to the embodiment of the present disclosure can evaluate with high accuracy whether there are defects in the insulating coating portion of an electrode sheet, which is difficult to inspect by conventional vision.

[0066] In addition, the electrode sheet inspection system according to the embodiment of the present disclosure can effectively select defects in the electrode sheet and improve the visibility of the insulating coating portion, regardless of the degree of inclination of the coating portion in the electrode sheet.

[0067] In addition, the electrode sheet inspection system according to the embodiment of the present disclosure can reduce loss and improve the manufacturing yield of the electrode sheet by accurately inspecting defects in the insulating coating portion of the electrode sheet.

[0068] In addition, the electrode sheet inspection system according to the embodiment of the present disclosure can improve process yield and productivity by applying it to the assembly process and electrode manufacturing process of a secondary battery, etc.

[0070] Hereinafter, another embodiment of the present disclosure is described using FIGS. 7 and 8. In the following embodiment, configurations that overlap with those described in FIGS. 1 to 6 are omitted from the description.

[0072] FIG. 7 is a schematic diagram showing an electrode sheet inspection system according to another embodiment of the present disclosure.

[0073] Referring to FIG. 7, the electrode sheet inspection system (200) according to the present embodiment may include a conveying unit (210) for conveying an electrode sheet, a measuring unit (220) for measuring the electrode sheet, a control unit (230) for receiving an image from the measuring unit (220), an electrode sheet meandering detection unit (240), and a defect location display unit (250).

[0074] The electrode sheet may include a metal sheet (11), a coating portion (12) formed by coating a slurry on the metal sheet (11), and an insulating coating portion (15) made of an insulating material that covers the end of the coating portion (12). The electrode sheet inspection system (200) according to the present embodiment can detect whether the insulating coating portion (15) is defective in the electrode sheet being transported with high accuracy. In addition, the electrode sheet meandering detection unit (240) controls the transport path of the electrode sheet, and the defect location display unit (250) can display the defect when a defect in the insulating coating portion (15) is confirmed.

[0075] The above measuring unit (220) may include a first and second lighting unit that applies light to the electrode sheet and a shooting unit that obtains an image of the insulating coating unit (15) by the light.

[0076] The electrode sheet meandering detection unit (240) may be provided at the front of the measurement unit (220) with respect to the transfer path of the electrode sheet.

[0077] The electrode sheet meandering detection unit (240) may include a detection sensor that measures the transport path of the electrode sheet. The electrode sheet meandering detection unit (240) may transmit to the control unit (230) if the transport path measured by the detection sensor deviates by a first distance from a pre-entered range. The control unit (230) may adjust the position of one or more of the first to third lighting units and the shooting unit according to the information transmitted from the electrode sheet meandering detection unit (240).

[0078] For example, the electrode sheet meandering detection unit (240) can be transmitted to the control unit (230) when the first distance is 3 mm or more. When the transport path of the electrode sheet deviates from the first distance, the reflection path of the light applied from the first to third lighting units changes, and as a result, the visibility of the insulating coating unit (15) may be reduced.

[0079] Accordingly, the electrode sheet meandering detection unit (240) is provided prior to the measurement unit (220) to check the transport path of the electrode sheet and transmit it to the control unit (230), thereby enabling control of the angle, position, etc. of at least one of the first to third lighting units and the shooting unit.

[0080] The electrode sheet meandering detection unit (240) can control the influence on the detection of defects in the insulating coating unit (15) caused by the electrode sheet's transport path by confirming the electrode sheet's transport path before the measurement unit (220).

[0081] The above defect location indicator (250) may be provided at the rear end of the measuring unit (220) with respect to the transfer path of the electrode sheet. If the control unit (230) determines that at least one of the thickness and width of the insulating coating unit (15) is defective, the control unit (230) may transmit the information to the defect location indicator (250).

[0082] The above defect location indicator (250) may include an ink marking device. The above defect location indicator (250) may be marked on the electrode sheet using the ink marking device.

[0083] The defect location indicator (250) indicates only the defective part of the insulating coating part (15), thereby allowing for the selective removal of only the defective part of the insulating coating part (15). Therefore, unlike conventional methods, instead of discarding the entire electrode sheet arrangement, a portion is selected to distinguish between good and defective products, thereby improving the productivity of the secondary battery. Furthermore, the defective part of the insulating coating part (15) among the electrode sheets can be identified by the defect location indicator (250), allowing for effective analysis and feedback regarding the impact on the process.

[0085] FIG. 8 is a flowchart illustrating an electrode sheet inspection method according to another embodiment of the present disclosure.

[0086] Referring to FIG. 8, the electrode sheet inspection method according to the present embodiment may include: an insulating coating part measurement step (S100) in which an insulating coating part of the electrode sheet is measured by a measuring part while the electrode sheet is transported and an image is obtained; and an insulating coating part determination step (S200) in which the image is analyzed and the insulating coating part is determined to be defective.

[0087] The above measuring unit may include: first and second lighting units provided on the upper side of the electrode sheet to irradiate light onto the electrode sheet; a third lighting unit provided adjacent to the side of the electrode sheet to irradiate light onto the electrode sheet; and a shooting unit provided on the upper side of the electrode sheet to photograph the electrode sheet and transmit the image to the control unit.

[0088] In the above insulation coating part measurement step (S100), the shooting unit can generate an image by light applied by the first to third lighting units. The image can be transmitted to the control unit.

[0089] In the above insulation coating measurement step (S100), the electrode sheet can move at a constant speed while simultaneously measuring the insulation coating part by the measurement unit. The insulation coating measurement step (S100) can measure the insulation coating part without stopping the movement of the electrode sheet, thereby improving process efficiency.

[0090] The above-mentioned imaging unit is provided at an angle of 40° to 65° with respect to the electrode sheet, and can acquire an image by light irradiated by each of the first to third illumination units.

[0091] In the above insulation coating part determination step (S200), the control unit can determine whether the insulation coating part is defective by determining the image.

[0092] Prior to the insulation coating part measurement step, an electrode sheet path detection step for measuring the transfer path of the electrode sheet may be further included. The electrode sheet path detection step may measure the transfer path of the electrode sheet by means of a detection sensor. If the transfer path measured by the detection sensor deviates by a first distance from a pre-entered range, it is transmitted to a control unit, and the control unit may adjust the position of one or more of the first to third lighting units and the imaging unit.

[0093] By measuring the transfer path of the electrode sheet prior to the insulation coating measurement step and transmitting this to the control unit, the defect status of the insulation coating can be effectively determined.

[0094] After the insulation coating part determination step described above, a defect location marking step for indicating the bonding location of the electrode sheet may be further included. The defect location marking step may indicate the defect on the electrode sheet if the insulation coating part is determined to be defective in the insulation coating part determination step. By marking the defective portion of the insulation coating part on the electrode sheet, for example using an ink marking device, the defective portion can be effectively identified and controlled.

[0095] An electrode sheet inspection method according to an embodiment of the present disclosure may further include: an electrode sheet path detection step for measuring a transport path of the electrode sheet prior to the insulation coating part measurement step; and a defect location indication step for indicating a bonded position of the electrode sheet after the insulation coating part determination step. The electrode sheet path detection step, the insulation coating part measurement step, the insulation coating part determination step, and the defect location indication step may be performed in-line.

[0096] The above electrode sheet inspection method can determine whether the insulating coating portion of the electrode sheet is defective with high accuracy, and the accuracy of measuring defects in the insulating coating portion can be improved by the electrode sheet path detection step. In addition, by further including a defect location marking step, the defective part of the insulating coating portion in the electrode sheet can be easily identified, thereby improving productivity.

[0098] A person skilled in the art to which this disclosure pertains will understand that this disclosure may be practiced in other specific forms without altering the technical concept or essential features thereof. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. The scope of this disclosure is defined by the claims set forth below rather than by the detailed description above, and all modifications or variations derived from the meaning and scope of the claims and equivalents thereof should be interpreted as being included within the scope of this disclosure. Explanation of the symbols

[0099] 10 : Electrode sheet 100 : Electrode Sheet Inspection System 110 : Transfer unit 120 : Measuring part 121 : 1st lighting unit 122 : 2nd lighting unit 123 : 3rd lighting unit 124 : Filming Unit 130 : Control unit

Claims

Claim 1 An electrode sheet inspection system comprising: a conveying unit for conveying an electrode sheet having an insulating coating portion; a measuring unit for measuring the insulating coating portion of the electrode sheet; and a control unit for analyzing an image transmitted from the measuring unit; wherein the measuring unit comprises: first and second lighting units provided on the upper side of the electrode sheet to irradiate light onto the electrode sheet; a third lighting unit provided adjacent to the side of the electrode sheet to irradiate light onto the electrode sheet; and a shooting unit provided on the upper side of the electrode sheet to photograph the electrode sheet and transmit the image to the control unit. Claim 2 An electrode sheet inspection system according to claim 1, wherein the first illumination unit comprises a white LED having a wavelength of 380 nm to 760 nm, and the second and third illumination units each comprise a blue LED having a wavelength of 350 nm to 495 nm. Claim 3 An electrode sheet inspection system according to claim 1, wherein the first lighting unit is spaced apart from the electrode sheet by a first distance of 90 mm to 1100 mm and irradiates the light at a first angle of 70° to 95° with respect to the electrode sheet, the second lighting unit is spaced apart from the electrode sheet by a second distance of 90 mm to 1100 mm and irradiates the light at a second angle of 75° to 95° with respect to the electrode sheet, and the third lighting unit is spaced apart from the electrode sheet by a third distance of 70 mm to 130 mm and irradiates the light at a third angle of 10° to 30° with respect to the electrode sheet. Claim 4 An electrode sheet inspection system according to claim 1, wherein the imaging unit is provided at a fourth angle of 40° to 65° with respect to the electrode sheet, and acquires an image by light irradiated by each of the first to third illumination units. Claim 5 An electrode sheet inspection system according to claim 1, further comprising an electrode sheet meandering detection unit provided at the front end of the measuring unit with respect to the transfer path of the electrode sheet. Claim 6 In claim 5, the electrode sheet meandering detection unit includes a detection sensor that measures the transport path of the electrode sheet, and when the transport path measured by the detection sensor deviates by a first distance from a pre-entered range, it is transmitted to the control unit, and the control unit adjusts the position of one or more of the first to third lighting units and the shooting unit according to the information transmitted from the electrode sheet meandering detection unit. Claim 7 In claim 1, the control unit analyzes the image transmitted from the measuring unit to measure at least one of the thickness and width of the insulating coating part and determines whether there is a defect in the electrode sheet inspection system. Claim 8 In claim 7, an electrode sheet inspection system further comprising a defect location indicator provided at the rear end of the measuring unit with respect to the transfer path of the electrode sheet. Claim 9 An electrode sheet inspection system according to claim 8, wherein if at least one of the thickness and width of the insulating coating part is determined to be defective by the control unit, the control unit transmits to the defect location indicator, the defect location indicator includes an ink marking device, and the defect location indicator uses the ink marking device to mark on the electrode sheet. Claim 10 In claim 1, the electrode sheet comprises: a metal sheet; a coating portion formed on at least one of one side and the other side of the metal sheet; a non-coating portion where the metal sheet is exposed and the coating portion is not provided; and an insulating coating portion provided to cover at least a portion of the coating portion at the boundary between the coating portion and the non-coating portion; and the electrode sheet inspection system is an electrode sheet inspection system that determines whether the insulating coating portion is defective. Claim 11 An electrode sheet inspection method using an electrode sheet inspection system according to any one of claims 1 to 10, comprising: an insulating coating part measurement step of obtaining an image by measuring the insulating coating part of the electrode sheet by means of a measuring unit while transporting the electrode sheet and having an insulating coating part; and an insulating coating part determination step of determining whether the insulating coating part is defective by analyzing the image; wherein the measuring unit comprises: first and second lighting units provided on the upper side of the electrode sheet to irradiate light onto the electrode sheet; a third lighting unit provided adjacent to the side of the electrode sheet to irradiate light onto the electrode sheet; and a shooting unit provided on the upper side of the electrode sheet to photograph the electrode sheet and transmit the image to the control unit. Claim 12 In claim 11, the above-mentioned imaging unit is provided at an angle of 40° to 65° with respect to the electrode sheet, and an electrode sheet inspection method is used to acquire an image by light irradiated by each of the first to third illumination units. Claim 13 In claim 11, prior to the insulation coating part measurement step, the electrode sheet path detection step further comprises measuring the transfer path of the electrode sheet, wherein the electrode sheet path detection step measures the transfer path of the electrode sheet by means of a detection sensor, and if the transfer path measured by the detection sensor deviates by a first distance from a pre-entered range, transmits it to a control unit, and the control unit adjusts the position of one or more of the first to third lighting units and the imaging unit. Claim 14 An electrode sheet inspection method according to claim 11, further comprising a defect location marking step for marking a bonding location of the electrode sheet after the insulation coating part judgment step, wherein the defect location marking step marks the electrode sheet when the insulation coating part is judged to be defective in the insulation coating part judgment step. Claim 15 An electrode sheet inspection method according to claim 11, further comprising: an electrode sheet path detection step for measuring the transport path of the electrode sheet prior to the insulation coating part measurement step; and a defect location indication step for indicating the bonding position of the electrode sheet after the insulation coating part judgment step; wherein the electrode sheet path detection step, the insulation coating part measurement step, the insulation coating part judgment step, and the defect location indication step are performed in-line.

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