Unit cell inspection device

Abstract

The present invention relates to a unit cell inspection device, the unit cell inspection device including: a transport unit configured to transport a plurality of unit cells, each having an electrode, in a predetermined transport direction and including a plurality of transport rollers arranged along the transport direction; and an optical inspection unit configured to optically sense an inspection target unit cell, which is a unit cell positioned at a predetermined inspection position among the plurality of unit cells transported by the transport unit, wherein each of the unit cells further includes an electrode tab extending from the electrode and exposed to an outside of a separator provided in each of the unit cells, the optical inspection unit configured to set an area including an area where at least a portion of the electrode tab is located at the inspection position as a Region of Interest (ROI), and an adjacent transport roller, which is a transport roller disposed adjacent to the Region of Interest among the plurality of transport rollers, may be configured not to overlap the Region of Interest.

Description

Technical Field

[0001] [Cross - reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2022 - 0020455 filed on February 16, 2022 and Korean Patent Application No. 10 - 2023 - 0019638 filed on February 14, 2023, and all the contents disclosed in the documents of the Korean patent applications are included as part of this specification.

[0002] The present invention relates to a unit cell inspection device.

Background Art

[0003] Generally, a secondary battery, unlike a primary battery that cannot be charged, means a battery that can be charged and discharged, and is widely used in electronic devices such as mobile phones, notebook computers, camcorders, or electric vehicles. In particular, a lithium - ion secondary battery has a larger capacity and a higher energy density than a nickel - cadmium battery or a nickel - hydrogen battery, so its utilization degree has a tendency to increase rapidly.

[0004] Secondary batteries can be classified into cylindrical batteries and prismatic batteries in which an electrode assembly is built into a cylindrical or prismatic metal can according to the shape of the battery case, and pouch - type batteries in which the electrode assembly is built into a pouch - type case made of an aluminum laminate sheet, etc.

[0005] FIG. 1 is a view showing an example of a pouch - type secondary battery. The pouch - type secondary battery 1 includes an electrode assembly 2 formed by alternately laminating electrodes and a separator, and a pouch 二十 that houses the electrode assembly 2. Electrode tabs 15 may be respectively connected to the electrodes of the electrode assembly 2. The electrode tabs 15 may be welded to each other in a predetermined area and then connected to an electrode lead 17. The pouch 二十 includes a recessed cup portion 21 for housing the electrode assembly 2. The cup portion 21 of the pouch 二十 may be formed in one or two. FIG. 1 illustrates a pouch 二十 including a left - hand cup portion and a right - hand cup portion. A peripheral portion 23 (terrace) is formed by sealing around the cup portion 21.

[0006] On the other hand, during the manufacturing process of the electrode assembly 2, it is possible to optically inspect for any abnormalities in the unit cells constituting the electrode assembly 2 (for example, whether or not the electrode tabs of the unit cells are broken). This can be done by analyzing the images after photographing the unit cells. However, if the object to be inspected for abnormalities (for example, the electrode tabs of the unit cells) is obscured by other objects during the process of acquiring the image of the unit cells, it may be difficult to determine the presence or absence of abnormalities by analyzing the acquired image. For example, if rollers placed on the underside of the unit cells for transporting the unit cells obscure the electrode tabs of the unit cells, it may be difficult to accurately acquire an image of the electrode tabs, making it difficult to reliably determine the presence or absence of abnormalities in the electrode tabs through the acquired image. [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The object of the present invention is to provide a unit cell inspection device that can accurately determine whether or not there is an abnormality in the unit cell by preventing the unit cell being obscured by other objects during the process of acquiring an image of the unit cell for inspection. [Means for solving the problem]

[0008] In one example, the unit cell inspection device includes a transport unit equipped with a plurality of transport rollers arranged along a predetermined transport direction and configured to transport a plurality of unit cells, each having an electrode, in a predetermined transport direction, and an optical inspection unit configured to optically sense a unit cell to be inspected, which is a unit cell among the plurality of unit cells transported by the transport unit that comes to be located at a predetermined inspection position, wherein each unit cell further comprises an electrode tab extending from the electrode and exposed to the outside of a separation membrane provided on each unit cell, and the optical inspection unit is configured to set a region of interest (ROI) that includes a region in which at least a part of the electrode tab is located at the inspection position, and adjacent transport rollers, which are transport rollers among the plurality of transport rollers that are located adjacent to the region of interest, may be configured so as not to overlap with the region of interest.

[0009] In another example, the region of interest may be defined based on the region where the electrode tab is located at the inspection position during normal transport of the unit cell, and the region where the electrode tab is located at the inspection position during oblique transport of the unit cell.

[0010] In yet another example, the region of interest may be configured to include a region extending outward from the separation membrane by a first distance in the longitudinal direction at the longitudinal end of the separation membrane where the electrode tab begins to be exposed when the electrode tab is positioned longitudinally on the adjacent transport roller perpendicular to the transport direction, and a region extending inward from the separation membrane by a second distance in the opposite longitudinal direction at the end.

[0011] In yet another example, the first distance may be a length defined in the longitudinal direction, and may be set based on the exposed length of the electrode tab that is exposed to the outside of the separation membrane at the end of the separation membrane.

[0012] In yet another example, the first distance may be 15 mm to 30 mm.

[0013] In yet another example, the second distance may be a length defined in the longitudinal direction, and may be set based on the exposed length of the electrode tab that is exposed to the outside of the separation membrane at the end of the separation membrane and a predetermined margin distance.

[0014] In yet another example, the second distance may be 15 mm to 30 mm.

[0015] In yet another example, the first distance may be less than or equal to the second distance.

[0016] In yet another example, the adjacent transport roller may be provided with a length that does not infringe upon the area of ​​interest.

[0017] In yet another example, the optical inspection unit may include a lamp positioned above the unit cell to be inspected, which is configured to irradiate light toward the unit cell to be inspected, and a camera positioned below the unit cell to be inspected, which is configured to photograph the unit cell to be inspected while it is illuminated by the lamp.

[0018] In yet another example, the optical inspection unit may further include a reflector that changes the imaging path by the camera in an orthogonal direction.

[0019] In yet another example, the electrode tab includes a positive electrode tab and a negative electrode tab extending from one of the electrodes, a positive electrode, and the other electrode, a negative electrode, respectively, in the longitudinal direction of the adjacent transport rollers perpendicular to the transport direction and in the opposite direction, and the optical inspection unit may include a positive electrode tab inspection unit that optically inspects the positive electrode tab by setting a region of interest that includes the region in which at least a part of the positive electrode tab is located at the inspection position, and a negative electrode tab inspection unit that optically inspects the negative electrode tab by setting a region of interest that includes the region in which at least a part of the negative electrode tab is located at the inspection position.

[0020] In yet another example, the adjacent transfer roller may be arranged so as to at least partially overlap with the inspection target unit cell that comes to be located at the inspection position.

[0021] In yet another example, the distance between the adjacent transfer roller and another transfer roller arranged closest to the adjacent transfer roller may be shorter than the width of the unit cell defined in the transfer direction.

Advantages of the Invention

[0022] According to the present invention, since the adjacent transfer roller does not infringe on the region of interest, when processing the region of interest in the image acquired by the optical inspection unit, the problem of being unable to determine or misjudging the presence or absence of abnormality of the electrode tab due to the interference of the transfer roller can be solved.

Brief Description of the Drawings

[0023] [Figure 1] It is a diagram showing an example of a pouch-type secondary battery. [Figure 2] It is a diagram showing a unit cell inspection device according to Example 1 of the present invention. [Figure 3] It is a plan view of the inspection device of FIG. 2 as viewed from above. [Figure 4] It is a diagram of the inspection target unit cell located at the inspection position as viewed from below, and illustrates a case where the transfer roller hides the electrode tab in the region of interest. [Figure 5] It is a diagram of the inspection target unit cell located at the inspection position as viewed from below, and illustrates a case where the transfer roller does not hide the electrode tab in the region of interest. [Figure 6] It is a diagram of the inspection target unit cell located at the inspection position as viewed from below, and illustrates a case where the separation film is obliquely transferred. [Figure 7] It is a diagram specifically showing the optical inspection unit in the inspection device of FIG. 2. [Figure 8] It is a diagram showing a unit cell inspection device according to Example 2 of the present invention.

Modes for Carrying Out the Invention

[0024] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings, so that they can be easily implemented by a person with ordinary skill in the art to which the present invention pertains. However, the present invention may be embodied in a variety of different forms and is not limited to or restricted by the following embodiments.

[0025] In order to clearly explain the present invention, detailed descriptions of prior art that are irrelevant to the description or that may obscure the essence of the invention are omitted. In this specification, when assigning reference numerals to components in each drawing, the same or similar reference numerals are used throughout the specification for components that are the same or similar.

[0026] Furthermore, the terms and words used in this specification and the claims shall not be interpreted in a manner limited to their ordinary and lexicographical meanings, but rather in a manner consistent with the technical idea of ​​the present invention, in accordance with the principle that inventors themselves may define the concepts of terms as appropriate in order to best describe their invention.

[0027] Example 1 Figure 2 shows a unit cell inspection device according to Embodiment 1 of the present invention, and Figure 3 is a plan view of the inspection device of Figure 2 as seen from above. The device according to Embodiment 1 of the present invention is a device for inspecting unit cells 10, and may be, for example, a device for inspecting electrode tabs 15a and 15b of the unit cell 10. The inspection device according to this embodiment may include a transfer unit 110 for transporting the unit cell 10 and an optical inspection unit 130 for inspecting the unit cell 10.

[0028] The transfer unit 110 may be provided to transfer the unit cell 10 in a predetermined transfer direction (D1). For example, the transfer unit 110 may include a belt conveyor (not shown) for transferring the unit cell 10. The belt conveyor may include a drive roller (not shown) that provides driving force and an annular belt (not shown) that is circulated by the drive roller. The unit cell 10 may be placed on the belt circulated by the drive roller and transferred.

[0029] The transfer unit 110 may be implemented in a manner that transfers the separation film 19, as shown in Figure 2. The electrode assembly 2 (see Figure 1) that constitutes the battery may be composed of various types. For example, the electrode assembly 2 may be composed of a stack-folding type. The stack-folding type electrode assembly 2 may be manufactured by folding a unit cell 10 (full cell or bi-cell) in which electrodes 11a, 11b and a separation membrane 13 are stacked in a certain order, using the separation film 19. The transfer unit 110 may transfer the separation film 19 and the unit cell 10 placed on the separation film 19 (see Figure 3). For this purpose, the transfer unit 110 may include a drive roller (not shown) for unwinding the separation film 19 from a roller (not shown) on which the separation film 19 is wound. Since the separation film 19 also plays the role of a separation membrane, the separation film 19 and the separation membrane 13 contained in the unit cell 10 may all be referred to as separation membranes below. For reference, the inspection device in this embodiment may be positioned in front of or as part of the folding device.

[0030] The transfer unit 110 may include a plurality of transfer rollers 111 arranged along the transfer direction (D1). The transfer rollers 111 may support the separation film 19 during its transfer. For this purpose, the transfer rollers 111 may be positioned below the separation film 19. The transfer rollers 111 may be idler rollers to which no driving force is provided.

[0031] The optical inspection unit 130 may be configured to optically sense the unit cell 10' to be inspected (see Figure 2). The optical inspection unit 130 may be configured to capture an image of the unit cell 10' to be inspected, process it, and inspect whether there are any abnormalities in the unit cell 10'. For this purpose, the optical inspection unit 130 may include a camera 133 (see Figure 7), such as a CCD camera, for photographing the unit cell 10' to be inspected. Here, the unit cell 10' to be inspected may be a unit cell 10 that is located at a predetermined inspection position (I) (see Figure 2) among a plurality of unit cells 10 transported by the transport unit 110. The inspection position (I) may be a position in which the camera 133 of the optical inspection unit 130 can photograph the unit cell 10.

[0032] The optical inspection unit 130 may set the region of interest (R) (see Figure 5) (ROI) to include the area where the electrode tabs 15a and 15b are located at the inspection position (I). The region of interest (R) may be an area in the image captured by the camera 133 of the optical inspection unit 130 that requires processing (image processing) to determine whether or not there is an abnormality. By setting the region of interest (R) to include the area where the electrode tabs 15a and 15b are located at the inspection position (I), the optical inspection unit 130 can inspect whether or not there is an abnormality in the electrode tabs 15a and 15b. If it is possible to determine whether or not there is an abnormality in only a part of the electrode tabs 15a and 15b, the region of interest (R) may be set to include the area where a part of the electrode tabs 15a and 15b are located. Here, the electrode tabs 15a and 15b may extend from the electrodes 11a and 11b and be provided in the unit cell 10 so as to be exposed to the outside of the separation membrane 13 that separates the electrodes 11a and 11b. For example, Figure 3 illustrates electrode tabs 15a and 15b that are exposed to the outside of the separation membrane 13 of the unit cell 10 and also exposed to the outside of the separation film 19. For reference, in Figure 5, which will be described later, the region of interest (R) is set such that it includes a portion of one of the two electrode tabs 15a and 15b.

[0033] When the optical inspection unit 130 photographs the unit cell 10' to be inspected, the transport roller 111' of the transport unit 110 may interfere with the optical inspection unit 130's photography. For example, the optical inspection unit 130 may photograph the unit cell 10' to be inspected from below, but if the transport roller 111' is formed to be long in the longitudinal direction (D2) of the transport roller 111' as shown in Figure 4, the transport roller 111' may obscure a part of the electrode tab 15a in the region of interest (R') when the optical inspection unit 130 is taking a photograph. The electrode tabs 15a and 15b may also bend inward into the separation film 19 due to collisions with other parts during transport, but if the transport roller 111' obscures the electrode tab 15a in the region of interest (R'), it may be difficult for the optical inspection unit 130 to reliably acquire an image of the electrode tab 15a that is bent inward into the separation film 19. Such problems caused by obscuration (or superposition) may become more pronounced during oblique transport, as will be discussed later. For example, the degree to which the transport roller obscures the region of interest may be greater during oblique transport compared to normal transport. Figure 4 is a view from below of the unit cell to be inspected at the inspection position, illustrating a case where the transport roller obscures the electrode tab in the region of interest.

[0034] In the unit cell inspection apparatus according to this embodiment, in order to resolve the above-mentioned problems, the adjacent transfer roller 111a, which is a transfer roller 111 positioned adjacent to the region of interest (R), may be provided so as not to overlap with the region of interest (R), as shown in Figure 5. For example, the adjacent transfer roller 111a may be provided so as not to encroach on the region of interest (R). The length of the transfer roller 111a in Figure 5 may be shorter than the length of the transfer roller 111' in Figure 4. For example, when electrode tabs 15a and 15b are provided so as to be exposed in the longitudinal direction (D2) and the opposite direction of the adjacent transfer roller 111a, respectively (and when two regions of interest are set corresponding to the electrode tabs, as in Embodiment 2 described later), the length of the adjacent transfer roller 111a in Figure 5 may be 60 mm shorter than the length of the transfer roller 111' in Figure 4. Figure 5 is a view from below of a unit cell to be inspected located at the inspection position, illustrating a case where the transfer roller does not hide the electrode tabs in the region of interest. For reference, the presence or absence of superposition can be determined by the stacking direction of the electrode and the separation film, or by the direction perpendicular to the separation film (up and down direction, using Figure 2 as a reference).

[0035] In this embodiment, the unit cell inspection device does not have adjacent transfer rollers 111a encroaching on the region of interest (R). Therefore, when the optical inspection unit 130 processes the region of interest (R) from the image it has acquired, it is possible to eliminate the problem of being unable to determine, or incorrectly determining, whether there are any abnormalities in the electrode tabs 15a and 15b due to interference from the transfer rollers 111.

[0036] On the other hand, in this embodiment, the adjacent transfer roller 111a may be positioned to at least partially overlap the unit cell 10' to be inspected, which will be located at the inspection position (I), in order to resolve the following problems. Figure 5 illustrates an adjacent transfer roller 111a that partially overlaps the electrodes 11a, 11b and the separation membrane 13 of the unit cell 10' to be inspected.

[0037] The separation film 19 is prone to sagging vertically downwards during the manufacturing process. During the manufacturing of stack-folding type electrode assemblies, the tension on the separation film may be interrupted during the folding process (for example, when preparing to fold the next electrode assembly after the completion of one electrode assembly). When such an interruption occurs, the tension applied to the separation film weakens, making it prone to sagging downwards. In this case, if the supply of separation film continues upstream of the inspection device, this sagging may become more pronounced. Furthermore, if unit cells are placed on the separation film, the weight of the unit cells may cause the sagging of the separation film to become even more pronounced.

[0038] When such sagging occurs, the captured image is distorted, making it impossible to accurately inspect the object being examined. Furthermore, deformation such as wrinkles may occur in the electrode assembly. In the captured image, the separation membrane can be represented by a light color and the electrodes by a dark color. When a change from a dark color to a light color is recognized (for this reason, a trigger sensor is usually used), it can be recognized that the unit cell has passed (or arrived) and imaging can be started (after a predetermined time has elapsed). However, if the separation film sags, problems arise with this recognition, and problems may also occur with the timing of imaging.

[0039] To resolve these issues, that is, to prevent the separation film 19 from sagging, the adjacent transfer rollers 111a in this embodiment may be positioned to support the separation film 19 by at least partially overlapping the unit cell 10' under inspection, as shown in Figure 5. Alternatively, the spacing between the transfer rollers 111 may be narrowed to support the separation film 19. For example, the spacing between an adjacent transfer roller 111a and the other transfer roller 111 (or other adjacent transfer roller) positioned closest to it may be shorter than the width of the unit cell defined in the transfer direction (D1) (e.g., the width of the electrode in the left-right direction relative to Figure 5). This minimizes the area of ​​the separation film 19 that is not supported by the transfer rollers. Alternatively, for supporting the separation film 19, the adjacent transfer rollers 111a may have a maximum length (see Figure 5) that does not overlap the region of interest (or is separated by a predetermined extra distance in the region of interest).

[0040] The unit cell inspection device of this embodiment can achieve both the prevention of sagging of the separation film and the prevention of interference of the captured image by adjacent transport rollers, as described above.

[0041] On the other hand, the region of interest (R) may be defined as follows:

[0042] Firstly, the region of interest (R) may be set taking into account the region (A1) where the electrode tab 15a is located at the inspection position (I) (see Figure 2) during normal transport of the unit cell 10, as shown in Figure 5. Normal transport refers to the case where the separation film 19 is transported along a defined path, and can be contrasted with oblique transport, which is the case where the separation film 19 is transported deviating from the defined path. As shown in Figure 5, the electrode tab 15a may be located in region A1 at the inspection position (I) during normal transport.

[0043] However, the optical inspection unit 130 can determine that an abnormality has occurred in the electrode tab 15a when the portion of the electrode tab 15a exposed to the outside of the separation film 19 bends outwards from the separation film 19, or when the portion of the electrode tab 15a exposed to the outside of the separation film 19 bends inwards from the separation film 19. For such determination, the region of interest (R) may be set to include the region where the portion of the electrode tab 15a exposed to the outside of the separation film 19 is located, and the region where the portion bent inwards is located when the portion of the electrode tab 15a exposed to the outside of the separation film 19 bends inwards from the separation film 19.

[0044] Secondly, the region of interest (R) may be set taking into consideration at least one of the first distance (L1) and the second distance (L2) described later. When the electrode tab 15a is positioned in the longitudinal direction (D2) of the adjacent transport roller 111a, perpendicular to the transport direction (D1) of the unit cell 10, the electrode tab 15a begins to be exposed to the outside of the separation film 19 at the end 19a on the longitudinal direction (D2) side of the separation film 19. The first distance (L1) is the distance set as the longitudinal direction (D2) at the end 19a of the separation film 19 as described above, and the second distance (L2) is the distance set as the opposite direction to the longitudinal direction (D2) at the end 19a of the separation film 19. The region of interest (R) may be set to include a region extending outward from the end 19a of the separation film 19 by a first distance (L1), and a region extending inward from the end 19a of the separation film 19 by a second distance (L2).

[0045] The first distance (L1) may be set based on the exposed length (h1) of the electrode tab 15a that is exposed to the outside of the separation film 19 at the end 19a of the separation film 19. The exposed length (h1) of the electrode tab 15a may be the length defined in the longitudinal direction (D2). For example, the first distance (L1) may be set similarly to the exposed length (h1) of the electrode tab 15a so as to include the exposed portion of the electrode tab 15a located at the inspection position (I) (see Figure 2) in the region of interest (R). Alternatively, considering that the electrode tab 15a may bend or shift position during skewed transport, and that a margin area may be needed during image processing, the first distance (L1) may be set to be longer than the exposed length (h1), i.e., a predetermined margin distance, as shown in Figure 5. For example, if the exposed length (h1) of the electrode tab 15a is 15 mm, the first distance (L1) may be set to 15 mm to 30 mm.

[0046] The second distance (L2) may be set based on the exposed length (h1) of the electrode tab 15a that is exposed to the outside of the separation film 19 at the end 19a of the separation film 19 and a predetermined margin distance. If the exposed portion of the electrode tab 15a is completely folded inward into the separation film 19, the exposed portion of the electrode tab 15a may be located inside the separation film 19 by the exposed length (h1) at the end 19a of the separation film 13. To ensure that all such cases can be inspected, the second distance (L2) may be set taking into account the exposed length (h1) of the electrode tab 15a. Furthermore, taking into account the displacement of the electrode tab 15a, the margin area during image processing, etc., the second distance (L2) may be set taking into account the exposed length (h1) of the electrode tab 15a and a predetermined margin distance. For example, if the exposed length (h1) of the electrode tab 15a is 15 mm, the second distance (L2) may be set to 15 mm to 30 mm. On the other hand, the second distance (L2) may be greater than or equal to the first distance (L1).

[0047] Thirdly, the region of interest (R) may be set based on the region where the electrode tab 15a is located at the inspection position (I) during normal transport of the unit cell 10, and the region where the electrode tab 15a is located at the inspection position (I) during oblique transport of the unit cell 10. The separation film 19 may be transported in a twisted state for various reasons during transport, as shown in Figure 6. In Figure 6, reference numeral 19a indicates the end of the separation film 19 during normal transport, and reference numeral 19a' indicates the end of the separation film 19 during oblique transport. Even if the position of the electrode tab 15a changes due to such twisting, the region of interest (R) may be set considering both the position of the electrode tab 15a during normal transport (see A1 in Figure 5) and the position of the electrode tab 15a during oblique transport (see A2 in Figure 6) in order to inspect for abnormalities in the electrode tab 15a. This allows, for example, at least a portion of the electrode tab to be included in the region of interest even during oblique transport, and it is possible that the transport rollers do not overlap the region of interest set in this way.

[0048] On the other hand, the optical inspection unit 130 may be configured as follows, as shown in Figure 7. Figure 7 is a diagram specifically showing the optical inspection unit of the inspection apparatus in Figure 2.

[0049] The optical inspection unit 130 may include a lamp 131 that is positioned to illuminate the unit cell 10' to be inspected. The lamp 131 can highlight the unit cell 10' so that the camera 133 (described later) can clearly photograph the unit cell 10'. The lamp 131 may be a backlight. The lamp 131 may be positioned above the unit cell 10' to be inspected. The optical inspection unit 130 may include a flat dome 137 to illuminate the unit cell 10' to be inspected uniformly at various angles.

[0050] The optical inspection unit 130 may include a camera 133 that is provided to photograph the unit cell 10' to be inspected while it is illuminated by light from the lamp 131. The camera 133 may be a CCD camera. The camera 133 may be positioned below the unit cell 10' to be inspected, opposite to the lamp 131. With this arrangement, the unit cell 10' to be inspected may be located between the camera 133 and the lamp 131.

[0051] The optical inspection unit 130 may include a reflector 135 that changes the imaging path of the camera 133 in a perpendicular direction. Using the reflector 135 increases the degree of freedom of position of the camera 133 and also reduces the vertical size of the inspection device.

[0052] Example 2 Figure 8 shows a unit cell inspection device according to Embodiment 2 of the present invention. The inspection device of Embodiment 2 differs from the inspection device of Embodiment 1 in that it has two inspection units. The inspection device of Embodiment 2 will be described below, focusing on these differences. For reference, the matters described in Embodiment 1 may be applied identically or similarly to Embodiment 2.

[0053] In this embodiment, the electrode tabs 15a and 15b of the unit cell 10' under inspection may include a positive electrode tab and a negative electrode tab extending from one of the electrodes 11a and 11b, which is the positive electrode, and the other, which is the negative electrode, in the longitudinal direction (D2) of the adjacent transport roller 111a and the opposite direction. That is, the positive electrode tab and the negative electrode tab may protrude in opposite directions from each other.

[0054] The optical inspection unit 130 of this embodiment may include a positive electrode tab inspection unit 130L for inspecting the positive electrode tab and a negative electrode tab inspection unit 130R for inspecting the negative electrode tab, so as to inspect all positive and negative electrode tabs that protrude in opposite directions from each other.

[0055] The positive electrode tab inspection unit 130L can optically inspect the positive electrode tab by setting a region of interest (R) that includes the region where at least a portion of the positive electrode tab is located at the inspection position (I). The positive electrode tab inspection unit 130L may include a lamp 131L, a flat dome 137L, a reflector 135L, and a camera 133L, similar to those described in Example 1.

[0056] The negative electrode tab inspection unit 130R can optically inspect the negative electrode tab by setting a region of interest (R) that includes the region where at least a portion of the negative electrode tab is located at the inspection position (I). The negative electrode tab inspection unit 130R may also include a lamp 131R, a flat dome 137R, a reflector 135R, and a camera 133R, similar to those described in Example 1.

[0057] The above description is merely illustrative of the technical concept of the present invention, and a person with ordinary skill in the art to which the present invention belongs can make various modifications and alterations as long as they do not deviate from the essential characteristics of the present invention.

[0058] Therefore, the embodiments disclosed in this invention are for illustrative purposes only, and not to limit the technical concept of the invention, and the scope of the technical concept of the invention is not limited by such embodiments.

[0059] The scope of protection of this invention shall be interpreted in accordance with the following claims, and all technical ideas within an equivalent scope shall be interpreted as being included within the scope of this invention.

Claims

1. A transfer unit is provided to transfer a plurality of unit cells, each having an electrode, in a predetermined transfer direction, and comprises a plurality of transfer rollers arranged along the transfer direction, The optical inspection unit is provided to optically sense a unit cell to be inspected, which is a unit cell that will be located at a predetermined inspection position among a plurality of unit cells transported by the transport unit, Each of the unit cells further comprises an electrode tab extending from the electrode and exposed to the outside of the separation membrane provided on each of the unit cells, The optical inspection unit is provided to set a region of interest (ROI) that includes the region in which at least a portion of the electrode tab is located at the inspection position. Among the plurality of transfer rollers, the adjacent transfer roller, which is a transfer roller positioned adjacent to the region of interest, is provided so as not to overlap with the region of interest. The optical inspection unit is a unit cell inspection device that photographs the unit cell to be inspected from below the unit cell to be inspected.

2. The aforementioned area of ​​interest is, The unit cell inspection device according to claim 1, which is set based on the region where the electrode tab is located at the inspection position during normal transport of the unit cell, and the region where the electrode tab is located at the inspection position during oblique transport of the unit cell.

3. The transfer unit transfers the separation film and transfers the unit cells placed on the separation film, The aforementioned area of ​​interest is, The unit cell inspection apparatus according to claim 1, wherein when the electrode tab is positioned in the longitudinal direction of the adjacent transport roller perpendicular to the transport direction, the electrode tab begins to be exposed at the longitudinal end of the separation film, the separation film is configured to include a region extending outward by a first distance in the longitudinal direction and a region extending inward by a second distance in the opposite longitudinal direction at the end.

4. The first distance is, The unit cell inspection apparatus according to claim 3, wherein the length defined in the longitudinal direction is set based on the exposed length of the electrode tab that is exposed to the outside of the separation film at the end of the separation film.

5. The unit cell inspection apparatus according to claim 3, wherein the first distance is 15 mm to 30 mm.

6. The aforementioned second distance is, The unit cell inspection apparatus according to claim 3, wherein the length defined in the longitudinal direction is set based on the exposed length of the electrode tab that is exposed to the outside of the separation film at the end of the separation film and a predetermined margin distance.

7. The unit cell inspection apparatus according to claim 3, wherein the second distance is 15 mm to 30 mm.

8. The unit cell inspection apparatus according to claim 3, wherein the first distance is less than or equal to the second distance.

9. The adjacent transfer roller is The unit cell inspection device according to claim 1, provided to have a length that does not infringe upon the region of interest.

10. The aforementioned optical inspection unit is A lamp is provided to irradiate light toward the unit cell to be inspected, and is positioned above the unit cell to be inspected. The unit cell inspection apparatus according to claim 1, further comprising: a camera positioned below the unit cell to be inspected, which is provided to photograph the unit cell to be inspected while it is illuminated by the lamp; and the unit cell to be inspected.

11. The aforementioned optical inspection unit is The unit cell inspection apparatus according to claim 10, further comprising a reflector that changes the shooting path of the camera in an orthogonal direction.

12. The electrode tab is The adjacent transport rollers, perpendicular to the transport direction, include a positive electrode tab and a negative electrode tab, extending from one of the electrodes, which is a positive electrode, and the other electrode, which is a negative electrode, respectively, in the longitudinal direction and the opposite direction of the transport direction. The aforementioned optical inspection unit is A positive electrode tab inspection unit sets a region of interest that includes the region in which at least a part of the positive electrode tab is located at the inspection position, and optically inspects the positive electrode tab. A unit cell inspection apparatus according to claim 1, comprising: a negative electrode tab inspection unit that sets a region including the region in which at least a part of the negative electrode tab is located at the inspection position as a region of interest and optically inspects the negative electrode tab.

13. The unit cell inspection apparatus according to claim 1, wherein the adjacent transfer roller is arranged to at least partially overlap the unit cell to be inspected, which will be located at the inspection position.

14. The unit cell inspection apparatus according to any one of claims 1 to 13, wherein the distance between the adjacent transport roller and the other transport roller positioned closest to the adjacent transport roller is shorter than the width of the unit cell as defined in the transport direction.

Images