Battery cell inspection device

Abstract

A battery cell inspection device according to an embodiment of the present invention may comprise: a first transfer unit for transferring a battery cell; a vision inspection unit for acquiring appearance information of the battery cell; a second transfer unit for transferring the battery cell that has been determined to be abnormal from the appearance information acquired from the vision inspection unit; a pickup unit for moving the battery cell transferred by the second transfer unit; and a plasma inspection unit for using a plasma arc to inspect whether the surface of the battery cell transferred by the pickup unit has defects.

Description

Battery cell inspection device

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0185134 dated December 12, 2024 and Korean Patent Application No. 10-2025-0195538 dated December 10, 2025, and all contents disclosed in the documents of said Korean patent applications are incorporated herein as part of this specification.

[0003] The present invention relates to a battery cell inspection device, and more specifically, to a battery cell inspection device capable of performing battery cell inspection in a non-contact manner and executing it automatically and continuously.

[0004] In modern society, as the use of portable devices such as mobile phones, laptops, camcorders, and digital cameras, as well as energy storage systems (ESS), has become commonplace, the development of technologies in related fields is becoming active. Furthermore, rechargeable secondary batteries are being utilized as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs) as a solution to address air pollution caused by conventional gasoline vehicles using fossil fuels; consequently, the need for the development of secondary batteries is increasing.

[0005] Currently commercialized rechargeable batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium-ion batteries. Among these, lithium-ion batteries are receiving the most attention due to their advantages of free charging and discharging, low self-discharge rate, and high energy density.

[0006] These lithium secondary batteries primarily use lithium-based oxides and carbon materials as the positive and negative active materials, respectively. The lithium secondary battery comprises an electrode assembly in which a positive plate and a negative plate, each coated with the positive and negative active materials, are arranged with a separator in between, and an outer casing, namely a battery case, that seals and houses the electrode assembly together with an electrolyte.

[0007] While small mobile devices use one or two or three battery cells per device, medium-to-large devices such as automobiles or energy storage systems (ESS) require high output and large capacity. Therefore, medium-to-large battery modules in which multiple battery cells are electrically connected are used.

[0008] Since it is desirable for medium-to-large battery modules to be manufactured with the smallest possible size and weight, prismatic batteries and pouch-type batteries, which can be stacked with high integration density and have a low weight-to-capacity ratio, are mainly used as battery cells for medium-to-large battery modules.

[0009] Since these battery modules contain multiple battery cells, there is a problem in that if a thermal event occurs in any one battery cell, it can easily propagate to adjacent battery cells through the electrode leads. Therefore, it is important to manage normal or defective battery cells during the battery cell manufacturing process.

[0010] However, currently, the determination of surface defects in battery cells is performed by operators who visually inspect the surface and use an insulation resistance meter to directly verify current flow by bringing the defective area into contact with the metal layer at the end of the battery cell to check for damage to the insulation layer. Consequently, over-inspection or under-inspection occurs due to the operator's visual inspection, and the risk of damage to the battery cell increases during the process of checking for insulation layer damage on the surface. Furthermore, variations occur among operators depending on their skill level, and it is difficult to establish a database regarding inspection information.

[0011] The problem that the present invention aims to solve is to provide a battery cell inspection device capable of performing battery cell inspection in a non-contact manner and executing it automatically and continuously.

[0012] However, the problems that the embodiments of the present invention aim to solve are not limited to the problems described above and can be expanded in various ways within the scope of the technical ideas included in the present invention.

[0013] A battery cell inspection device according to one embodiment of the present invention may include a first transfer unit for transferring a battery cell, a vision inspection unit for acquiring external appearance information of the battery cell and inspecting for defects, a second transfer unit for transferring the battery cell determined to have defects based on the external appearance information acquired from the vision inspection unit, a pickup unit for moving the battery cell transferred by the second transfer unit, and a plasma inspection unit for inspecting for defects on the surface of the battery cell transferred by the pickup unit using a plasma arc.

[0014] The above battery cell inspection device may further include a third transfer unit for transferring the battery cell determined to be defective by the plasma inspection unit.

[0015] The above pickup unit can move the battery cell determined to be defective by the plasma inspection unit to the third transfer unit, and move the battery cell determined to be normal by the plasma inspection unit to the first transfer unit.

[0016] The first transfer unit and the second transfer unit transfer the battery cell in directions orthogonal to each other, and the second transfer unit and the third transfer unit transfer the battery cell in directions orthogonal to each other.

[0017] The first transfer unit and the third transfer unit transfer the battery cell in opposite directions to each other, and the pickup unit is positioned between the first transfer unit and the third transfer unit so as to be accessible on the first transfer unit, the second transfer unit, and the third transfer unit.

[0018] The above battery cell inspection device may further include a defect determination unit that determines an external appearance abnormality of the battery cell from the vision inspection unit and determines a surface defect from the plasma inspection unit.

[0019] The above plasma inspection unit may include a plasma nozzle that generates a plasma arc on the surface of the battery cell at a predetermined distance from the surface of the battery cell.

[0020] The above plasma inspection unit further includes a vision camera that acquires an image of the location where the plasma arc is injected into the battery cell, and the defect determination unit can determine whether the surface of the battery cell is defective based on the shape of the plasma arc acquired by the vision camera.

[0021] The above defect determination unit can extract a light detection area in which a light amount greater than a predetermined amount is detected based on the amount of light at the location where the plasma arc is injected, and determine that a surface defect has occurred in the battery cell if the light detection area is larger than a predetermined area.

[0022] The above defect determination unit extracts the brightness of each pixel on an image obtained by the vision camera, extracts pixels where the brightness of each pixel is greater than or equal to a predetermined value as the light detection area, and the area of ​​the light detection area when the surface of the battery cell is defective may be larger than the area of ​​the light detection area when the surface of the battery cell is normal.

[0023] The above defect determination unit can determine that the surface of the battery cell is normal when the area of ​​the light detection region is 0.

[0024] The above plasma inspection unit may further include a lighting unit that repeatedly flashes at a predetermined period while the plasma arc is injected into the battery cell.

[0025] The plasma inspection unit acquires shape information of the battery cell when the lighting unit is in an on state, and acquires shape and location information of the plasma arc when the lighting unit is in an off state, and the defect determination unit determines the location of the plasma arc occurrence for the battery cell and can determine whether there is a surface defect of the battery cell at the location of the plasma arc occurrence.

[0026] The vision camera is positioned to aim at the same area as the surface of the battery cell that the plasma nozzle aims at, and the direction in which the vision camera aims may be oblique to the direction in which the plasma nozzle aims at the surface of the battery cell.

[0027] The direction in which the above plasma nozzle is oriented may be the direction in which the plasma nozzle forms the shortest distance with the surface of the battery cell.

[0028] The above plasma inspection unit further includes a conductive member disposed on a surface opposite to the surface of the battery cell where the plasma arc is injected, and the defect determination unit can determine whether the surface of the battery cell is defective based on the amount of change in voltage measured at the conductive member when the plasma arc is injected.

[0029] The above defect determination unit may determine that a surface defect has occurred in the battery cell if the amount of change in voltage measured at the conductive member deviates from a predetermined standard value.

[0030] The defect determination unit can primarily detect an external defect of the battery cell from the external information of the battery cell obtained through the vision inspection unit, and obtain the location coordinates of the area where the external defect occurred on the surface of the battery cell where the external defect occurred.

[0031] The above plasma nozzle can move to generate a plasma arc corresponding to the position coordinates of the area where the above external abnormality occurred.

[0032] The above pickup unit may be a multi-joint robot capable of gripping the battery cell.

[0033] The above pickup unit can rotate while holding the battery cell so that when the surface inspection of the battery cell is performed by the plasma inspection unit, the plasma arc generated by the plasma nozzle is injected onto the entire surface of the battery cell.

[0034] The above battery cell includes an electrode assembly and a pouch case housing the electrode assembly, wherein the pouch case has an internal metal layer exposed through its outer periphery and the outer periphery is joined and sealed while the electrode assembly is housed therein, and the defect determination unit can determine that no surface defect of the battery cell occurs in the area where the metal layer is exposed through the outer periphery while the pouch case is sealed.

[0035] A battery cell inspection device according to another embodiment of the present invention may include a main transfer unit for transferring a battery cell, a vision inspection unit for acquiring external information of the battery cell and inspecting for defects, a first loading unit for transferring and loading the battery cell determined to have defects from the external information acquired by the vision inspection unit, a pickup unit for moving the battery cell loaded in the first loading unit, and a plasma inspection unit for inspecting for defects on the surface of the battery cell transferred by the pickup unit using a plasma arc.

[0036] The above battery cell inspection device may further include a second loading unit to which the battery cell determined to be defective by the plasma inspection unit is transferred and loaded.

[0037] The above pickup unit can move the battery cell determined to be defective by the plasma inspection unit to the second loading unit, and move the battery cell determined to be normal by the plasma inspection unit to the main transfer unit.

[0038] The battery cell inspection device according to the embodiments of the present invention can improve inspection accuracy by automating the inspection of the battery cell and performing the inspection of the battery cell surface according to a certain standard rather than the judgment of an operator.

[0039] In addition, the battery cell inspection device according to the embodiments of the present invention can perform inspection of the battery cell in a non-contact manner, thereby preventing the risk of damage to the battery cell during the inspection process.

[0040] In addition, since each process for battery cell inspection according to the embodiments of the present invention can be performed sequentially and continuously, a large volume of battery cell inspection is possible, and productivity can be improved.

[0041] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims.

[0042] FIG. 1 is a schematic diagram illustrating a battery cell inspection device according to one embodiment of the present invention.

[0043] FIG. 2 illustrates the case where a battery cell is moved from the second transfer unit of the battery cell inspection device shown in FIG. 1 to the plasma inspection unit.

[0044] FIG. 3 illustrates a case where a battery cell is moved after the battery cell has been inspected by the plasma inspection unit of the battery cell inspection device shown in FIG. 2.

[0045] FIG. 4 is a schematic side view illustrating an example of a plasma inspection unit of a battery cell inspection device illustrated in FIG. 1.

[0046] Figure 5 is a cross-sectional view schematically illustrating the cross-section of a pouch case of a battery cell.

[0047] FIG. 6 is a diagram illustrating an example of the behavior of a plasma arc and the detection thereof when the battery cell surface is normal during inspection of defects through the plasma inspection unit shown in FIG. 4.

[0048] FIG. 7 is a diagram illustrating an example of the behavior of a plasma arc and the detection thereof when a defect is detected during an inspection of whether the surface of a battery cell is defective through the plasma inspection unit shown in FIG. 4.

[0049] Figure 8 is a diagram showing an image of a plasma arc acquired by a vision camera while the illumination unit of the plasma inspection unit is flashing.

[0050] FIG. 9 is a side view schematically illustrating the plasma inspection unit shown in FIG. 4 and another example of a plasma inspection unit.

[0051] FIG. 10 is a diagram showing the voltage measured at a conductive member when inspecting for defects on the surface of a battery cell through the plasma inspection unit illustrated in FIG. 9.

[0052] Figure 11 is a diagram illustrating an inspection exclusion area in a battery cell.

[0053] FIG. 12 is a schematic diagram illustrating a battery cell inspection device according to another embodiment of the present invention.

[0054] FIG. 13 illustrates the case where a battery cell is moved from the first loading section of the battery cell inspection device shown in FIG. 12 to the plasma inspection section.

[0055] FIG. 14 illustrates a case where a battery cell is moved after the battery cell has been inspected by the plasma inspection unit of the battery cell inspection device shown in FIG. 13.

[0056] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0057] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0058] Furthermore, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and thus the present invention is not necessarily limited to what is illustrated. Thicknesses have been enlarged in the drawings to clearly represent various layers and regions. Additionally, for convenience of explanation, the thickness of some layers and regions has been exaggerated in the drawings.

[0059] Furthermore, when a part such as a layer, membrane, region, or plate is said to be "on" or "on" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in between. Also, saying that a part is "on" or "on" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "on" or "on" facing the opposite direction of gravity.

[0060] In addition, terms indicating directions such as front, back, left, right, up, and down have been used; however, these terms are merely for the convenience of explanation and may vary depending on the location of the object or the observer.

[0061] Furthermore, throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0062] Additionally, throughout the specification, "planar" means when the subject part is viewed from above, and "cross-sectional" means when the cross-section obtained by vertically cutting the subject part is viewed from the side.

[0063] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0064] FIG. 1 is a schematic diagram illustrating a battery cell inspection device according to an embodiment of the present invention. FIG. 2 illustrates a case where a battery cell is moved from a second transfer unit of the battery cell inspection device illustrated in FIG. 1 to a plasma inspection unit. FIG. 3 illustrates a case where a battery cell is moved after inspection of the battery cell is performed from the plasma inspection unit of the battery cell inspection device illustrated in FIG. 2. FIG. 4 is a schematic side view illustrating the plasma inspection unit of the battery cell inspection device illustrated in FIG. 1.

[0065] Referring to FIGS. 1 to 4, a battery cell inspection device (100) according to one embodiment of the present invention may include a first transfer unit (110) for transferring a battery cell (10), a vision inspection unit (120) for acquiring external information of a battery cell (10) being transferred and inspecting for abnormalities, a second transfer unit (130) for transferring a battery cell (10) determined to have an abnormality from the external information acquired from the vision inspection unit (120), a plasma inspection unit (140) for inspecting for defects on the surface of a battery cell (10) transferred by the second transfer unit (130) by a plasma arc, a pickup unit (150) for moving a battery cell (10) from the second transfer unit (130) to the plasma inspection unit (140), and a third transfer unit (160) for transferring a battery cell (10) determined to be defective from the plasma inspection unit (140).

[0066] First, a battery cell (10) according to one embodiment of the present invention may be a pouch-type battery in which an electrode assembly having electrode leads protruding in one or both directions is housed in a pouch case (20). However, this is merely an example, and a battery cell according to another embodiment of the present invention may be a prismatic battery. For convenience of explanation, the following description will be based on a battery cell (10) that is a pouch-type battery.

[0067] The battery cell (10) may have a rectangular sheet shape. The battery cell (10) may be formed by housing an electrode assembly in a pouch case (20) of a laminate sheet comprising a resin layer and a metal layer, and then bonding the outer periphery of the pouch case (20). For example, the battery cell (10) may have a structure in which two electrode leads protrude from each end of the cell body facing each other. As another embodiment, a structure in which all electrode leads of the battery cell (10) protrude in one direction is also possible. One of the electrode leads is a positive electrode lead, and the other is a negative electrode lead.

[0068] A battery cell (10) can be manufactured by attaching the periphery of a pouch case (20) while an electrode assembly (not shown) is housed in the pouch case (20). As another example, the battery cell (10) may have the electrode assembly housed in a state where one side of the pouch case (20) is folded and the remaining sides are sealed. Meanwhile, a detailed description of the pouch case (20) will be described later with reference to FIG. 5.

[0069] The first transfer unit (110) is a device for transferring a battery cell (10) in one direction and may take the form of, for example, a conveyor. The conveyor is driven by a driving device not shown, and the battery cell (10) may be transferred along the progress of the conveyor. However, the type of the first transfer unit (110) is not limited to what is described above, and any device for transferring a battery cell (10) may be applied in various ways depending on the environment in which the present invention is implemented. For example, the first transfer unit (110) may take the form of a P&P device, a shuttle, etc. Meanwhile, the second transfer unit (130) and the third transfer unit (160) described later are also devices for transferring a battery cell (10) in the same way as the first transfer unit (110), so the same content as the first transfer unit (110) may be applied, and a detailed description thereof will be omitted.

[0070] The vision inspection unit (120) can obtain external information of the battery cell (10). As illustrated in FIG. 1, the battery cell (10) for which external information has been obtained through the vision inspection unit (120) can be transported through the first transport unit (110). However, the arrangement of the vision inspection unit (120) is not limited to what is described above. For example, the vision inspection unit (120) can obtain external information of the battery cell (10) being transported through the first transport unit (110).

[0071] The vision inspection unit (120) may include an image sensor (not shown) capable of acquiring an image of the battery cell (10). For example, the vision inspection unit (120) can acquire external information of the battery cell (10) by acquiring an image of the entire surface of the battery cell (10) through the image sensor. The external information of the battery cell (10) acquired by the vision inspection unit (120) can be transmitted to a defect determination unit described later, and the defect determination unit can determine whether there is an abnormality on the surface of the battery cell (10) from the external information of the battery cell (10).

[0072] The second transfer unit (130) can transfer a battery cell (10) that is determined to have an abnormality from the appearance information obtained from the vision inspection unit (120) among the battery cells (10) being transferred through the first transfer unit (110). To this end, although not shown in FIG. 1, the battery cell inspection device (100) may include a moving unit that moves the battery cell (10) being transferred through the first transfer unit (110) to the second transfer unit (130). For example, the moving unit may grasp the battery cell (10) on the first transfer unit (110) and move it to the second transfer unit (130). Meanwhile, the method by which the moving unit moves the battery cell (10) is not limited to the above description and can be modified and changed in various ways depending on the environment in which the present invention is implemented. For example, the moving unit can move the battery cell (10) on the first transfer section (110) toward the second transfer section (130).

[0073] The plasma inspection unit (140) first inspects the battery cell (10) that was determined to have an abnormality based on the appearance information obtained from the vision inspection unit (120) and finally determines whether there is a defect on the surface of the battery cell (10).

[0074] Referring to FIG. 4, the plasma inspection unit (140) may include a plasma nozzle (141) that generates a plasma arc on the surface of a battery cell (10) at a predetermined distance from the surface of the battery cell, a vision camera (142) that acquires an image of the position where the plasma arc is injected into the battery cell, a support unit (143) that supports the plasma nozzle (141) and the vision camera (142), a lighting unit (144) that repeatedly flashes at a predetermined period while the plasma arc is injected into the battery cell (10), and a holder unit (145) that supports the battery cell (10).

[0075] The plasma nozzle (141) can be extended toward the surface of the battery cell (10) to generate a plasma arc on the surface of the battery cell (10). The plasma generated from the plasma nozzle (141) refers to an ionized gas, and the ions and electrons within the plasma are charged particles and possess electrical conductivity. When a plasma arc is generated on the surface of the battery cell (10), the shape of the plasma arc generated in the damaged part of the surface of the battery cell (10) and in the undamaged part may differ. Various gases such as Ar, He, Ne, Air, and N2 can be used as the plasma reaction gas, and preferably, the plasma reaction gas may be Ar.

[0076] A vision camera (142) can acquire an image of the location where a plasma arc is injected into a battery cell (10), and for this purpose, the vision camera (142) may include an image sensor (not shown). That is, the plasma inspection unit (140) can acquire the shape of the plasma arc injected into the battery cell (10) through the vision camera (142). The shape information of the plasma arc injected into the battery cell (10) acquired by the vision camera (142) can be transmitted to a defect determination unit described later, and the defect determination unit can determine whether there is a surface defect of the battery cell (10) from the shape information of the plasma arc of the battery cell (10). Meanwhile, although the shape of the plasma arc has been described as one factor for determining whether there is a surface defect of the battery cell (10), it is not limited to what has been described above. That is, various physical and electrical factors may be used to determine whether there is a surface defect of the battery cell (10). For example, thermal changes, sound changes, electrical changes, etc., resulting from the generation of a plasma arc may be used. More specifically, as an example of an electrical change, the surface defect of the battery cell (10) can be determined based on the amount of change in current that generates a plasma arc in the plasma nozzle (141).

[0077] The vision camera (142) may be positioned to aim at the same area as the surface of the battery cell (10) that the plasma nozzle (141) aims at. At this time, the direction (d1) that the plasma nozzle (141) aims at may be the direction in which the plasma nozzle (141) forms the shortest distance to the surface of the battery cell (10). That is, the direction (d1) that the plasma nozzle (141) aims at may be a direction orthogonal to the surface of the battery cell (10). In addition, the direction (d2) that the vision camera (142) aims at may be oblique to the direction (d1) that the plasma nozzle (141) aims at the surface of the battery cell (10). That is, the direction (d2) that the vision camera (142) aims at may form a predetermined angle (θ) with respect to the direction (d2) that the plasma nozzle (141) aims at. Because the direction (d2) that the vision camera (142) is directed is oblique to the direction (d1) that the plasma nozzle (141) is directed, the vision camera (142) can acquire an image of a larger area of ​​the battery cell (10).

[0078] The support member (143) is a member that supports the plasma nozzle (141) and the vision camera (142). The support member (143) can be moved by a driving means not shown in FIG. 4. For example, the support member (143) can be moved in a horizontal direction and / or a vertical direction. Thus, the plasma inspection unit (140) can perform an inspection of the battery cell (10) by moving the support member (143) to a position corresponding to the location of the area where an appearance abnormality occurred on the surface of the battery cell (10) while supporting the plasma nozzle (141) and the vision camera (142).

[0079] The lighting unit (144) can repeatedly flash at a predetermined cycle while the plasma arc is injected into the battery cell (10). For example, the lighting unit (144) can flash at least several times or dozens of times at a short cycle while the plasma arc is injected into the battery cell (10). When the lighting unit (144) is on, the overall shape of the battery cell (10) is clearly visible due to the light, and when the lighting unit (144) is off, the shape of the plasma arc injected into the battery cell (10) is clearly visible because there is no light. A method for determining surface defects of the battery cell (10) through the lighting unit (144) will be described later with reference to FIG. 7 below. Meanwhile, the position in which the lighting unit (144) is placed in the plasma inspection unit (140) in FIG. 4 is merely exemplary, and the position is not limited by the shape shown. That is, the position of the lighting unit (144) can be varied and changed according to the environment in which the present invention is implemented so as not to affect the plasma arc generated by the plasma nozzle (141) and the image obtained from the vision camera (142).

[0080] The holder portion (145) is a member that supports the battery cell (10). The battery cell (10) can be fixed by the holder portion (145) so that its position does not change while being inspected by the plasma inspection portion (140). The battery cell (10) is moved from the second transfer portion (130) to the holder portion (145) by the pickup unit (150) described later, and surface defects of the battery cell (10) can be determined while it is mounted on the holder portion (145).

[0081] Referring again to FIG. 2, the pickup unit (150) can move the battery cell (10) from the second transfer unit (130) to the plasma inspection unit (140). Also, referring to FIG. 3, the pickup unit (150) can move the battery cell (10) determined to be defective from the plasma inspection unit (140) to the third transfer unit (160), and move the battery cell (10) determined to be normal from the plasma inspection unit (140) to the first transfer unit (110).

[0082] The pickup unit (150) may be a multi-joint robot capable of gripping a battery cell (10). The pickup unit (150) may include an adsorption pad capable of adsorbing and gripping the battery cell (10). However, the method by which the pickup unit (150) grips the battery cell (10) is not limited to the method described above and may be modified and changed in various ways depending on the environment in which the present invention is implemented. For example, the pickup unit (150) may grip the battery cell (10) by physically pressing it.

[0083] As illustrated in FIG. 4, when surface inspection of a battery cell (10) is performed by the plasma inspection unit (140), the pickup unit (150) can rotate the battery cell (10) while holding it so that a plasma arc generated by the plasma nozzle (141) is injected onto the entire surface of the battery cell (10). For example, the pickup unit (150) can move the battery cell (10) while holding it so that one side of the battery cell (10) faces the plasma nozzle (141). After the plasma inspection unit (140) inspects one side of the battery cell (10), the pickup unit (150) can rotate the battery cell (10), and the plasma inspection unit (140) can inspect the other side of the battery cell (10) and can also inspect corners such as the terrace portion of the battery cell (10).

[0084] The first transfer unit (110) and the second transfer unit (130) can transfer battery cells in mutually orthogonal directions, and the second transfer unit (130) and the third transfer unit (160) can transfer battery cells in mutually orthogonal directions. At this time, the first transfer unit (110) and the third transfer unit (160) can transfer battery cells in opposite directions. Accordingly, the first transfer unit (110), the second transfer unit (130), and the third transfer unit (160) can surround the pickup unit (150) with one side open. For example, the first transfer unit (110), the second transfer unit (130), and the third transfer unit (160) can be arranged to form a "U" shape. Through such an arrangement, the battery cell inspection device (100) according to the embodiments of the present invention can use space efficiently, and as a result, the work path can be shortened and productivity can be improved.

[0085] The pickup unit (150) is positioned between the first transfer unit (110) and the third transfer unit (160) and is accessible to the first transfer unit (110), the second transfer unit (130), and the third transfer unit (160). The fact that the pickup unit (150) is accessible to the first transfer unit (110), the second transfer unit (130), and the third transfer unit (160) means that, for example, it is possible to grasp a battery cell (10) being transferred to the second transfer unit (130), and to move a battery cell (10) that has been judged as defective or normal by the plasma inspection unit (140) to the first transfer unit (110) or the third transfer unit (160).

[0086] The third transfer unit (160) can transfer the battery cell (10) that has been finally determined to have defects from the plasma inspection unit (140).

[0087] Battery cells (10) that are initially found to have no external defects through the vision inspection unit (120) can be continuously transported through the first transport unit (110). Even if a battery cell (10) is determined to have an external defect through the vision inspection unit (120) but is determined to be normal through the plasma inspection unit (140), it can be moved back to the first transport unit (110) through the pickup unit (150) and transported through the first transport unit (110). Battery cells (10) that are finally determined to have defects by the plasma inspection unit (140) can be transported separately from normal battery cells (10) through the third transport unit (160). In this way, since each process for inspecting battery cells (10) in the battery cell inspection device (100) according to the embodiments of the present invention can be performed sequentially and continuously, it is possible to inspect a large number of battery cells (10) and achieve improved productivity.

[0088] Although not illustrated in FIG. 1, the battery cell inspection device (100) may include a defect determination unit. The defect determination unit may be in the form of a processor, and the processor may include, for example, a microcontroller unit (MCU). The processor may be provided inside the battery cell inspection device (100) or separately provided outside the battery cell inspection device (100) to communicate remotely with the battery cell inspection device (100). The form of the processor may be varied or changed in various ways depending on the environment in which the present invention is implemented. The processor may control the overall operation of the battery cell inspection device (100). For example, the processor may control the operation of each of the first transfer unit (110), the second transfer unit (130), and the third transfer unit (160). Additionally, the processor may control the operation of the pickup unit (150).

[0089] The defect determination unit can determine an abnormality in the appearance of the battery cell by receiving external information of the battery cell from the vision inspection unit (120), and can determine a surface defect of the battery cell (10) by utilizing a plasma arc generated from the plasma inspection unit (140) described later.

[0090] Specifically, the defect determination unit can primarily detect an external defect of the battery cell (10) from the external information of the battery cell (10) obtained through the vision inspection unit (120), and obtain the location coordinates of the area where the external defect occurred on the surface of the battery cell (10) where the external defect occurred. When the defect determination unit performs an inspection on the plasma inspection unit (140), it can move the support unit (143) so that the plasma nozzle (141) generates a plasma arc at a location corresponding to the location coordinates of the area where the external defect occurred on the battery cell (10) through the vision inspection unit (120).

[0091] The defect determination unit can determine whether the surface of the battery cell (10) is defective based on at least one of the shape of the plasma arc obtained by the vision camera (142) and the amount of change of the current for generating the plasma arc.

[0092] For example, the defect determination unit may extract a light detection area where a light amount greater than a predetermined amount is detected based on the amount of light at the location where the plasma arc is injected, and if the light detection area is smaller than a predetermined area, it may determine that a surface defect has occurred in the battery cell (10). Alternatively, the defect determination unit may determine that a surface defect has occurred in the battery cell (10) if the amount of change in the current generating the plasma arc from the plasma nozzle (141) deviates from a predetermined standard value.

[0093] Meanwhile, more detailed information regarding the criteria for normal or defective surface of the battery cell (10) and the process for determining whether the surface of the battery cell (10) is defective will be described later.

[0094] Figure 5 is a cross-sectional view schematically illustrating the cross-section of a pouch case of a battery cell.

[0095] Specifically, FIG. 5(a) illustrates a normal pouch case (20). FIG. 5(b) illustrates an example in which a groove has occurred in the outer resin layer (21) on the surface of the pouch case (20), but the case is normal. FIG. 5(c) illustrates an example in which damage has occurred in the outer resin layer (21) on the surface of the pouch case (20).

[0096] Referring to FIG. 5(a), the pouch case (20) may be formed from a laminate sheet. Specifically, the pouch case (20) may include an inner resin layer (23) for sealing, a metal layer (22) for preventing penetration of material, and an outermost outer resin layer (21). Based on the electrode assembly inside the pouch case (20), the inner resin layer (23) may be located at the innermost position, the outer resin layer (21) may be located at the outermost position, and the metal layer (22) may be located between the inner resin layer (23) and the outer resin layer (21).

[0097] The pouch case (20) may further include a first adhesive layer (24) between the outer resin layer (21) and the metal layer (22) to laminate the outer resin layer (21) and the metal layer (22). Additionally, the pouch case (20) may further include a second adhesive layer (25) between the metal layer (22) and the inner resin layer (23) to laminate the metal layer (22) and the inner resin layer (23).

[0098] The outer resin layer (21) may have excellent tensile strength and weather resistance relative to its thickness and electrical insulation to protect the electrode assembly from the outside. This outer resin layer (21) may include polyethylene terephthalate (PET) resin or nylon resin. The metal layer (22) may maintain the mechanical strength of the pouch case (20) and prevent air, moisture, etc. from entering the interior of the pouch-type secondary battery. This metal layer (22) may include aluminum (Al). The inner resin layer (23) may be thermally fused to each other by heat and / or pressure applied while the electrode assembly is embedded. This inner resin layer (23) may include casted polypropylene (CPP) or polypropylene (PP).

[0099] If the outer resin layer (21) of the pouch case (20) is damaged, the metal layer (22) located below the outer resin layer (21) may be exposed to the outside. In this case, safety issues such as ignition or explosion may occur in the battery cell (10).

[0100] Referring to FIG. 5(b), a groove (g1) in which the metal layer (22) is not exposed may be formed in the outer resin layer (21) of the pouch case (20). In this case, the metal layer (22) is covered by the outer resin layer (21) through the groove (g1) and is not exposed to the outside. Accordingly, the pouch case (20) in which the groove (g1) in which the metal layer (22) is not exposed to the outside corresponds to a normal pouch.

[0101] However, a pouch case (20) having a groove (g1) formed so that the metal layer (22) is not exposed to the outside may be determined to have an abnormality in the appearance of the battery cell (10) by the aforementioned vision inspection unit (120). However, in the case of a groove (g1) where the metal layer (22) is not exposed to the outside, there is no risk of the metal layer (22) being exposed to the outside, so safety is not compromised for the battery cell (10). A pouch case (20) having such a groove (g1) where the metal layer (22) is not exposed to the outside may be determined to have a normal surface by the plasma inspection unit (140). Meanwhile, a detailed explanation of the process in which the surface of the battery cell (10) is determined to be normal through the plasma inspection unit (140) will be provided later.

[0102] Referring to FIG. 5(c), a groove (g2) in which a metal layer (22) is exposed may be formed in the outer resin layer (21) of the pouch case (20). In this case, the metal layer (22) inside the outer resin layer (21) is exposed to the outside through the groove (g2). Accordingly, the pouch case (20) in which the groove (g2) in which the metal layer (22) is exposed to the outside is a defective pouch.

[0103] As with the case of FIG. 5(b), a pouch case (20) having a groove (g2) formed in which the metal layer (22) is exposed to the outside can be determined by the aforementioned vision inspection unit (120) to have an abnormality in the appearance of the battery cell (10). In addition, in the case of a groove (g2) in which the metal layer (22) is exposed to the outside, there is a high risk of safety issues occurring with the battery cell (10) because the metal layer (22) is exposed to the outside. A pouch case (20) having such a groove (g2) in which the metal layer (22) is exposed to the outside can be determined to have a surface defect by the plasma inspection unit (140). Meanwhile, a detailed explanation of the process in which the surface of the battery cell (10) is determined to be defective through the plasma inspection unit (140) will be provided later.

[0104] FIG. 6 is a diagram illustrating an example of the behavior of a plasma arc and its detection when the surface of a battery cell is normal during an inspection for defects through the plasma inspection unit illustrated in FIG. 4. FIG. 7 is a diagram illustrating an example of the behavior of a plasma arc and its detection when the surface of a battery cell is defective during an inspection for defects through the plasma inspection unit illustrated in FIG. 4.

[0105] Specifically, FIG. 6(a) schematically illustrates the behavior of a plasma arc after it reaches the surface of a battery cell (10) by being injected from the plasma nozzle (141) of the plasma inspection unit (140) when the surface of the battery cell (10) is normal. FIG. 6(b) shows an image of the shape of the plasma arc when the surface of the battery cell (10) is normal. FIG. 6(c) illustrates the result after processing the image of FIG. 6(b) for the detection of the plasma arc. Additionally, FIG. 7(a) schematically illustrates the behavior of a plasma arc after it reaches the surface of a battery cell (10) by being injected from the plasma nozzle (141) of the plasma inspection unit (140) when the surface of the battery cell (10) is defective. FIG. 7(b) shows an image of the shape of the plasma arc when the surface of the battery cell (10) is defective. Figure 7(c) shows the result after processing the image of Figure 7(b) for the detection of a plasma arc.

[0106] Referring to FIGS. 6 and 7, a plasma arc is injected through a plasma nozzle (141) onto the surface of a battery cell (10) as shown in FIGS. 6 (a) and (b). When the surface of the battery cell (10) is normal as in FIGS. 6 (a) and (b), the metal layer (22) inside the pouch case (20) is not exposed to the outside, so the plasma arc can be reflected from the surface of the outer resin layer (21) of the pouch case (20). On the other hand, when the surface of the battery cell (10) is defective as in FIGS. 7 (a) and (b), the metal layer (22) inside the pouch case (20) is exposed to the outside, so the plasma arc is not reflected from the surface of the outer resin layer (21) of the pouch case (20) but can be absorbed by the inner metal layer (22).

[0107] In this way, when the surface of the battery cell (10) is defective, the plasma arc is absorbed at the surface of the battery cell (10). Therefore, compared to the plasma arc shape when the surface of the battery cell (10) is normal, the plasma arc can have a brighter shape (i.e., a larger amount of light) because the plasma arc is concentrated in a localized area. Additionally, compared to the plasma arc shape when the surface of the battery cell (10) is defective, the size (i.e., area) of the region where the plasma arc is concentrated, i.e., the region with a predetermined amount of light or more, can be larger.

[0108] Based on this, the defect determination unit can extract a light detection area through the shape of the plasma arc obtained from the vision camera (142) of the plasma inspection unit (140). Specifically, based on the amount of light at the location where the plasma arc is injected, a light detection area can be extracted in which a predetermined amount of light is detected relative to the surface of the battery cell (10) where the plasma arc is not injected.

[0109] For example, the defect determination unit may extract the brightness of each pixel on the images shown in FIG. 6(b) and FIG. 7(b), and may extract pixels where the brightness of each pixel is greater than or equal to a predetermined value as light detection areas. More specifically, when the defect determination unit extracts the brightness of each pixel on the image, it may determine the pixel brightness (G / L) based on black as 0 and white as 255. At this time, the defect determination unit may determine a case where the pixel brightness (G / L) is greater than or equal to a predetermined value (x) as a light detection area. For example, the defect determination unit may determine a case where the pixel brightness (G / L) is 150 or greater, preferably 200 or greater, as a light detection area. Meanwhile, the pixel brightness (G / L) is not limited by the above description and may be modified and changed in various ways depending on the environment in which the present invention is implemented.

[0110] When a light detection area is extracted, the defect determination unit calculates the area of ​​the light detection area, and if the light detection area is larger than a predetermined area, it can determine that a surface defect has occurred in the battery cell (10). For example, the defect determination unit can obtain the images shown in FIG. 6 (b) and FIG. 7 (b) by extracting the brightness of each pixel in the images shown in FIG. 6 (b) and FIG. 7 (b), and by processing the remaining area excluding the area where the pixel brightness (G / L) is greater than or equal to a predetermined value (x), that is, the area where the pixel brightness (G / L) is less than a predetermined value (x), as black (pixel brightness 0). More specifically, the defect determination unit can obtain the images shown in FIG. 6 (c) and FIG. 7 (c) by extracting the brightness of each pixel in the images shown in FIG. 6 (b) and FIG. 7 (b), and processing the brightness of the area where the pixel brightness (G / L) is less than 150, preferably less than 200, as 0. The defect determination unit can determine that a surface defect has occurred in the battery cell by calculating the area of ​​the region other than the black area on the images shown in FIG. 6 (c) and FIG. 7 (c), and if the light detection area is larger than a predetermined area.

[0111] For example, when comparing the light detection area formed in the surface normal battery cell (10) of FIGS. 6 (a) and (b) with the surface defective battery cell (10) of FIGS. 7 (a) and (b), the area of ​​the light detection area formed in the surface normal battery cell (10) is smaller than the area of ​​the light detection area formed in the surface defective battery cell (10). Meanwhile, the aforementioned predetermined area can be determined according to the intensity of the plasma arc emitted from the plasma nozzle (141), the distance between the plasma nozzle (141) and the surface of the battery cell (10), and in particular the brightness (G / L) of the pixel, and can be modified and changed in various ways depending on the environment in which the present invention is implemented.

[0112] For example, the defect determination unit may extract pixels whose brightness (G / L) is greater than or equal to a predetermined value (x) as a light detection area, and then determine whether a surface defect has occurred in the battery cell based on the presence or absence of the light detection area. That is, the defect determination unit may determine that the surface of the battery cell (10) is normal when the area of ​​the light detection area is 0. In such an example, the light detection area may be extracted based on a higher value, for example, 200, of the pixel brightness (G / L).

[0113] Figure 8 is a diagram showing an image of a plasma arc acquired by a vision camera while the illumination unit of the plasma inspection unit is flashing.

[0114] Referring to FIG. 8(a), when the illumination unit (144) is repeatedly flashing while the plasma arc is injected into the battery cell (10), the vision camera (142) can repeatedly acquire an image when the illumination unit (144) is on and an image when the illumination unit (144) is off. For example, FIG. 8(b) shows an image when the illumination unit (144) is off, and FIG. 8(c) shows an image when the illumination unit (144) is on.

[0115] As shown in FIG. 8(b), when the lighting unit (144) is off, there may be no or almost no influence from light other than the plasma arc, so the shape of the plasma arc acquired by the vision camera (142) can be seen more clearly and distinctly. However, since there is no light illuminating the battery cell (10), location information where the plasma arc occurs in the battery cell (10) can be obtained, but the exact location where the plasma arc occurs in the battery cell (10) cannot be known.

[0116] As shown in Fig. 8 (c), when the lighting unit (144) is on, light from the lighting unit (144) is generated along with the plasma arc, so the shape of the plasma arc acquired by the vision camera (142) may appear blurrier. However, since the lighting unit (144) generates light that illuminates the battery cell (10), the overall shape information of the battery cell (10) can be known.

[0117] Since the battery cell (10) is fixed in position by the holder (145) during the inspection of the battery cell (10), it can be positioned in the same location while the lighting unit (144) is flashing. For example, as shown in FIG. 8 (b) and (c), when the lighting unit (144) is off, the shape and location information of the plasma arc is obtained, and when the lighting unit (144) is on, the shape information of the battery cell (10) is obtained. Then, by combining the shape and location information of the plasma arc and the shape information of the battery cell (10), the location where the plasma arc occurs on the battery cell (10) can be accurately obtained. Therefore, by obtaining multiple images in the off and on states of the lighting unit (144) and combining them, not only the shape of the plasma arc but also the location where the plasma arc occurs on the battery cell (10) can be accurately obtained.

[0118] FIG. 9 is a schematic side view illustrating the plasma inspection unit shown in FIG. 4 and another example of a plasma inspection unit. FIG. 10 is a diagram showing the voltage measured at a conductive member when inspecting for defects on the surface of a battery cell through the plasma inspection unit shown in FIG. 9.

[0119] Referring to FIGS. 9 and 10, the plasma inspection unit (140') may include a conductive member (146) disposed on a surface opposite to the surface of the battery cell (10) on which the plasma arc is injected. For example, the conductive member (146) may be disposed on a holder unit (145) that supports the battery cell (10). The conductive member (146) may be an electrically conductive member for measuring changes in voltage when a plasma arc is injected into the battery cell (10) through the plasma inspection unit (140'). The conductive member (146) may be a flat plate-shaped member having a shape similar to that of the battery cell (10). For example, the conductive member (146) may be a member having a constant thickness, and the conductive member (146) may be implemented in various forms depending on the environment in which the present invention is implemented, such as a thin metal sheet, a conductive film, a conductive tape, or a conductive coating layer.

[0120] The defect determination unit can determine whether there is a defect on the surface of the battery cell (10) based on the amount of change in voltage measured at the conductive member (146) when the plasma arc is injected. For example, the defect determination unit can determine that a surface defect has occurred in the battery cell (10) if the amount of change in voltage measured at the conductive member (146) deviates from a predetermined standard value.

[0121] Referring again to FIGS. 6 and 7, when the surface of the battery cell (10) is normal as in FIGS. 6 (a) and (b), the metal layer (22) inside the pouch case (20) is not exposed to the outside, so the metal layer (22) located inside the battery cell (10) can be electrically insulated from the plasma arc. On the other hand, when the surface of the battery cell (10) is defective as in FIGS. 7 (a) and (b), the metal layer (22) inside the pouch case (20) is exposed to the outside, so the metal layer (22) located inside the battery cell (10) can be electrically connected to the plasma arc.

[0122] When a plasma arc is injected onto the surface of the battery cell (10), the battery cell (10) can function as a dielectric between the plasma nozzle (141) and the conductive member (146).

[0123] When the surface of the battery cell (10) is normal, the metal layer (22) inside the battery cell (10) and the plasma arc are electrically insulated, so even if the plasma arc is injected into the battery cell (10), there may be almost no change in capacitance through the battery cell (10). Accordingly, the voltage measured at the conductive member (146) can be maintained within a predetermined reference value.

[0124] If the surface of the battery cell (10) is defective, the electrical insulation between the metal layer (22) inside the battery cell (10) and the plasma arc is destroyed, so when the plasma arc is injected into the battery cell (10), problems such as a sudden change in capacitance through the battery cell (10) or local discharge may occur. Accordingly, the voltage measured at the conductive member (146) may deviate from a predetermined reference value.

[0125] Based on these points, the defect determination unit may determine that a surface defect has occurred in the battery cell (10) if the amount of change in voltage measured at the conductive member (146) deviates from a predetermined reference value. At this time, the predetermined reference value may be determined according to the intensity of the plasma arc emitted from the plasma nozzle (141), the distance between the plasma nozzle (141) and the surface of the battery cell (10), etc., and may be modified and changed in various ways depending on the environment in which the present invention is implemented.

[0126] Meanwhile, the method of inspecting surface defects of the battery cell (10) through the defect determination unit is not limited to what is described above and can be modified and changed in various ways depending on the environment in which the present invention is implemented. For example, the defect determination unit can calculate the amount of current and / or voltage applied to the plasma nozzle (141) of the plasma inspection unit (140). Specifically, the amount of change in current and / or voltage when a plasma arc is injected is measured, and if the amount of change in current and / or voltage that generates a plasma arc at the plasma nozzle (141) deviates from a predetermined standard value, it can be determined that a surface defect has occurred in the battery cell (10). For example, when comparing the amount of current and / or voltage applied while injecting a plasma arc into a surface-normal battery cell (10) in FIG. 6 (a) and (b) and a surface-defective battery cell (10) in FIG. 7 (a) and (b), the amount of current and / or voltage applied when injecting a plasma arc into a surface-defective battery cell (10) may be greater than in the case of a surface-normal battery cell (10).

[0127] Figure 11 is a diagram illustrating an inspection exclusion area in a battery cell.

[0128] Referring to FIG. 11, the battery cell (10) is an area (A) where the defect determination unit determines that no surface defects occur in the battery cell (10). E It may include ).

[0129] As described above, the battery cell (10) may include an electrode assembly and a pouch case (20) that houses the electrode assembly. The pouch case (20) may be formed in a predetermined shape to house the electrode assembly. For example, the pouch case (20) may be formed by cutting into a rectangular shape. In this case, the metal layer (22) inside the pouch case (20) may be exposed to the outside through the cut outer periphery.

[0130] A battery cell (10) can be formed by sealing the outer periphery of a pouch case (20) while the electrode assembly is housed in the pouch case (20). Therefore, even when the electrode assembly is sealed by the pouch case (20), a metal layer (22) can be exposed to the outside through the outer periphery of the pouch case (20). Accordingly, a plasma arc generated through the plasma inspection unit (140) can be absorbed by the metal layer (22) exposed through the outer periphery of the pouch case (20). In such a case, even if the surface of the battery cell (20) is normal, the defect judgment unit can determine that the surface of the battery cell (10) is defective as the plasma arc is absorbed.

[0131] Accordingly, the defect determination section is an area (A) where the metal layer (22) is exposed through the outer periphery of the battery cell (10) while the pouch case (20) is sealed. E ) can be determined that no surface defects occur in the battery cell (10). Through this, it is possible to prevent the surface of the battery cell (10) from being determined to be defective even when the surface is normal.

[0132] FIG. 12 is a schematic diagram illustrating a battery cell inspection device according to another embodiment of the present invention. FIG. 13 illustrates the case where a battery cell is moved from the first loading section of the battery cell inspection device illustrated in FIG. 12 to the plasma inspection section. FIG. 14 illustrates the case where a battery cell is moved after the inspection of the battery cell is performed from the plasma inspection section of the battery cell inspection device illustrated in FIG. 13.

[0133] Hereinafter, a battery cell inspection device (200) according to another embodiment of the present invention will be described with reference to FIGS. 12 to 14. However, detailed descriptions of components identical to or corresponding to the components described in the aforementioned battery cell inspection device (100) according to one embodiment of the present invention will be omitted.

[0134] Referring to FIGS. 12 to 14, the battery cell inspection device (200) may include a main transfer unit (210) for transferring a battery cell (10), a vision inspection unit (220) for acquiring external information of the battery cell (10) and inspecting for defects, a first loading unit (230) for transferring and loading a battery cell (10) that is determined to have defects from the external information acquired from the vision inspection unit (220), a plasma inspection unit (240) for inspecting for defects on the surface of the battery cell (10) transferred by a pickup unit (250) using a plasma arc, a pickup unit (250) for moving the battery cell (10) loaded in the first loading unit (230), and a second loading unit (260) for transferring and loading a battery cell (10) that is determined to have defects from the plasma inspection unit (240).

[0135] The main transfer unit (210) is a device for transferring a battery cell (10) in one direction, and since the same content as the first transfer unit (110) described above can be applied, a detailed description of the main transfer unit (210) will be omitted.

[0136] The first loading section (230) and the second loading section (260) can load battery cells (10) separately from the main transfer section (210).

[0137] The first loading unit (230) can receive and load battery cells (10) that are determined to have defects from the appearance information obtained from the vision inspection unit (240) among the battery cells (10) being transported through the main transport unit (210). To this end, although not shown in FIG. 12, the battery cell inspection device (200) may include a moving unit that moves the battery cells (10) being transported through the main transport unit (210) to the first loading unit (230). For example, the moving unit may grasp the battery cells (10) on the first transport unit (210) and move them to the first loading unit (230). Meanwhile, the method by which the moving unit moves the battery cells (10) is not limited to the above description and may be modified and changed in various ways depending on the environment in which the present invention is implemented.

[0138] Referring to FIG. 13, the pickup unit (250) can move the battery cell (10) from the first loading unit (230) to the plasma inspection unit (240). Additionally, referring to FIG. 14, the pickup unit (250) can move the battery cell (10) determined to be defective from the plasma inspection unit (240) to the second loading unit (260), and move the battery cell (10) determined to be normal from the plasma inspection unit (240) to the main transfer unit (210).

[0139] The second loading section (260) can load the battery cell (10) that was finally determined to be defective by the plasma inspection section (240).

[0140] The main transfer unit (210), the first loading unit (230), and the second loading unit (260) may be arranged to surround the pickup unit (250). For example, the pickup unit (250), the first loading unit (230), and the second loading unit (260) may be arranged on one side of the main transfer unit (210), and the first loading unit (230) and the second loading unit (260) may be arranged in opposite directions relative to each other with the pickup unit (250) as the center. Through such an arrangement, the battery cell inspection device (200) can utilize space efficiently, which can shorten the work path and improve productivity.

[0141] The pickup unit (250) is positioned on one side of the main transport unit (210) and is positioned between the first loading unit (230) and the second loading unit (260), thereby allowing access to the main transport unit (210), the first loading unit (230), and the second loading unit (260). The fact that the pickup unit (250) can access the main transport unit (210), the first loading unit (230), and the second loading unit (260) means, for example, that it is possible to grasp a battery cell (10) being transported to the first loading unit (230), and to move a battery cell (10) that has been judged as defective or normal by the plasma inspection unit (240) to the main transport unit (210) or the second loading unit (260).

[0142] Battery cells (10) that are initially found to have no external defects through the vision inspection unit (220) can be continuously transported through the main transport unit (210). Even if a battery cell (10) is determined to have an external defect through the vision inspection unit (220) but is determined to be normal through the plasma inspection unit (240), it can be moved back to the main transport unit (210) through the pickup unit (250) and transported through the main transport unit (210). Battery cells (10) that are finally determined to have defects by the plasma inspection unit (240) can be loaded separately from normal battery cells (10) through the second loading unit (260). In this way, since each process for inspecting battery cells (10) can be performed sequentially and continuously in the battery cell inspection device (200) according to the embodiments of the present invention, it is possible to inspect a large number of battery cells (10) and achieve improved productivity.

[0143] The drawings attached to this specification represent the components as conceptual diagrams for the convenience of understanding the invention. Accordingly, the spacing between components and the arrangement structure are not limited to those depicted, nor are the sizes and scales of the components limited to those depicted. These elements may be implemented by various modifications and changes to suit the environment in which the invention is implemented.

[0144] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention.

[0145] [Explanation of the symbol]

[0146] 10: Battery cell

[0147] 20: Pouch Case

[0148] 100: Battery cell inspection device

[0149] 110: 1st Transfer Unit

[0150] 120: Vision Inspection Department

[0151] 130: 2nd Transfer Unit

[0152] 140: Plasma Inspection Unit

[0153] 141: Plasma Nozzle

[0154] 142: Vision Camera

[0155] 143: Support

[0156] 150: Pickup Unit

[0157] 160: 3rd Transfer Unit

[0158] 200: Battery cell inspection device

[0159] 210: Main transfer unit

[0160] 220: Vision Inspection Department

[0161] 230: 1st Loading Section

[0162] 240: Plasma Inspection Unit

[0163] 250: Pickup Unit

[0164] 260: Second loading section

Claims

1. A first transfer unit for transferring a battery cell; A vision inspection unit that acquires external information of the above battery cell and inspects for abnormalities; A second transfer unit for transferring the battery cell determined to have an abnormality from the appearance information obtained from the vision inspection unit; A pickup unit for moving the battery cell transferred by the second transfer unit; and A battery cell inspection device comprising a plasma inspection unit that inspects the surface of the battery cell transported by the above pickup unit for defects by a plasma arc.

2. In Paragraph 1, A battery cell inspection device further comprising a third transfer unit for transferring the battery cell determined to be defective by the plasma inspection unit.

3. In Paragraph 2, A battery cell inspection device in which the above pickup unit moves the battery cell determined to be defective by the plasma inspection unit to the third transfer unit and moves the battery cell determined to be normal by the plasma inspection unit to the first transfer unit.

4. In Paragraph 3, The first transfer unit and the second transfer unit transfer the battery cell in directions orthogonal to each other, and A battery cell inspection device in which the second transfer unit and the third transfer unit transfer the battery cell in directions orthogonal to each other.

5. In Paragraph 4, The first transfer unit and the third transfer unit transfer the battery cell in opposite directions to each other, and A battery cell inspection device wherein the pickup unit is positioned between the first transfer unit and the third transfer unit and is accessible on the first transfer unit, the second transfer unit, and the third transfer unit.

6. In Paragraph 1, A battery cell inspection device further comprising a defect determination unit that determines an external appearance abnormality of the battery cell from the vision inspection unit and determines a surface defect from the plasma inspection unit.

7. In Paragraph 6, A battery cell inspection device comprising a plasma nozzle that generates a plasma arc on the surface of the battery cell at a predetermined distance from the surface of the battery cell.

8. In Paragraph 7, The above plasma inspection unit further includes a vision camera that acquires an image of the location where the plasma arc is injected into the battery cell, and A battery cell inspection device in which the above defect determination unit determines whether the surface of the battery cell is defective according to the shape of the plasma arc obtained by the vision camera.

9. In Paragraph 8, A battery cell inspection device, wherein the defect determination unit extracts a light detection area in which a predetermined amount of light is detected based on the amount of light at the position where the plasma arc is injected, and determines that a surface defect has occurred in the battery cell if the light detection area is larger than a predetermined area.

10. In Paragraph 9, The defect determination unit extracts the brightness of each pixel on an image acquired by the vision camera, and extracts pixels where the brightness of each pixel is greater than or equal to a predetermined value as the light detection area. A battery cell inspection device in which the area of ​​the light detection region when the surface of the battery cell is defective is larger than the area of ​​the light detection region when the surface of the battery cell is normal.

11. In Paragraph 10, The above defect determination unit determines that the surface of the battery cell is normal when the area of ​​the light detection region is 0, in a battery cell inspection device.

12. In Paragraph 9, A battery cell inspection device comprising a plasma inspection unit that further includes a lighting unit that repeatedly flashes at a predetermined period while the plasma arc is injected into the battery cell.

13. In Paragraph 12, The above plasma inspection unit acquires shape information of the battery cell when the lighting unit is in an on state, and acquires shape and position information of the plasma arc when the lighting unit is in an off state. The above defect determination unit determines the location where the plasma arc is generated for the battery cell and determines whether there is a surface defect of the battery cell at the location where the plasma arc is generated. A battery cell inspection device.

14. In Paragraph 8, The vision camera is positioned to aim at the same area as the area of ​​the battery cell surface that the plasma nozzle aims at, and A battery cell inspection device in which the direction in which the vision camera is directed is oblique to the direction in which the plasma nozzle is directed toward the surface of the battery cell.

15. In Paragraph 14, A battery cell inspection device in which the direction in which the plasma nozzle is directed is the direction in which the plasma nozzle forms the shortest distance with the surface of the battery cell.

16. In Paragraph 7, The above plasma inspection unit further includes a conductive member disposed on a surface opposite to the surface of the battery cell where the plasma arc is injected, and A battery cell inspection device in which the above defect determination unit determines whether the surface of the battery cell is defective based on the amount of change in voltage measured at the conductive member when the plasma arc is injected.

17. In Paragraph 16, A battery cell inspection device in which the above defect determination unit determines that a surface defect has occurred in the battery cell when the amount of change in the voltage measured in the above conductive member deviates from a predetermined reference value.

18. In Paragraph 7, The above defect determination unit primarily detects an appearance defect of the battery cell from the appearance information of the battery cell obtained through the vision inspection unit, and A battery cell inspection device for obtaining the location coordinates of the area where the appearance defect occurred on the surface of the battery cell where the appearance defect occurred.

19. In Paragraph 18, A battery cell inspection device in which the above plasma nozzle moves to generate a plasma arc corresponding to the position coordinates of the area where the above external defect occurred.

20. In Paragraph 7, The above pickup unit is a battery cell inspection device, which is a multi-joint robot capable of gripping the battery cell.

21. In Paragraph 20, A battery cell inspection device wherein the above pickup unit rotates while holding the battery cell so that the plasma arc generated by the plasma nozzle is injected onto the entire surface of the battery cell when the surface inspection of the battery cell is performed by the plasma inspection unit.

22. In Paragraph 6, The above battery cell includes an electrode assembly and a pouch case housing the electrode assembly, and The above pouch case has an internal metal layer exposed through its outer periphery, and the outer periphery is joined and sealed while the electrode assembly is housed therein. A battery cell inspection device in which the above defect determination unit determines that the area where the metal layer is exposed through the outer periphery while the pouch case is sealed does not have a surface defect of the battery cell.

23. Main transfer unit for transferring battery cells; A vision inspection unit that acquires external information of the above battery cell and inspects for abnormalities; A first loading unit in which the battery cell determined to have an abnormality from the appearance information obtained from the vision inspection unit is transferred and loaded; A pickup unit for moving the battery cell loaded in the first loading section; and A battery cell inspection device comprising a plasma inspection unit that inspects the surface of the battery cell transported by the above pickup unit for defects by a plasma arc.

24. In Paragraph 23, A battery cell inspection device further comprising a second loading section to which the battery cell determined to be defective by the plasma inspection section is transferred and loaded.

25. In Paragraph 24, A battery cell inspection device in which the above pickup unit moves the battery cell determined to be defective by the plasma inspection unit to the second loading unit and moves the battery cell determined to be normal by the plasma inspection unit to the main transfer unit.

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