Battery module inspection method

Abstract

The present invention relates to a method for inspecting a battery module, and the method for inspecting a battery module according to the present invention includes a first vision inspection process for inspecting a cell stack in which a plurality of battery cells are stacked, and inspecting the number and positions of electrode leads provided on each of the plurality of battery cells via a vision camera, and a second vision inspection process for inspecting the number and bending state of electrode leads provided on each of the plurality of battery cells via a vision camera after the first vision inspection process.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0012733, filed January 27, 2022, and Korean Patent Application No. 10-2023-0010161, filed January 26, 2023, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference. The present invention relates to a method for inspecting a battery module. [Background technology]

[0002] Unlike primary batteries, secondary batteries are rechargeable and have the potential to be small and have large capacities. Due to the increasing technological development and demand for mobile devices, the demand for secondary batteries as an energy source is rapidly increasing.

[0003] Secondary batteries are classified into coin-type batteries, cylindrical batteries, prismatic batteries, and pouch-type batteries depending on the shape of the battery case. In secondary batteries, the electrode assembly attached inside the battery case is a chargeable and dischargeable power generating element consisting of a laminated structure of electrodes and separators.

[0004] Secondary batteries have attracted much attention as energy sources for power plants such as electric bicycles, electric vehicles, and hybrid electric vehicles, as well as for mobile devices such as mobile phones, digital cameras, and laptop computers.

[0005] Small devices such as mobile phones and cameras use small battery packs containing a single battery cell, while medium- to large-sized devices such as laptops and electric vehicles use medium- to large-sized battery packs containing two or more battery cells connected in parallel and / or series. Therefore, the number of battery cells included in the battery pack can be set in various ways depending on the desired output voltage or charge / discharge capacity.

[0006] Meanwhile, when constructing a battery pack by connecting multiple battery cells in series / parallel, a common method is to first construct a battery module consisting of at least one battery cell, and then use this at least one battery module to construct the battery pack by adding other components. The number of battery modules included in the battery pack or the number of battery cells included in a battery module can be set in various ways depending on the desired output voltage or charge / discharge capacity. The battery module thus configured includes multiple stacked battery cells and a busbar frame that electrically connects the electrode leads of the multiple battery cells.

[0007] Previously, workers performed visual inspections before and after assembly of ICB busbar frame assemblies. This resulted in misdetections due to human inspection errors caused by worker-dependent inspections. In addition, labor costs increased as manual inspections of ICB busbar frame assemblies became more common. Summary of the Invention [Problem to be solved by the invention]

[0008] One aspect of the present invention is to provide a battery module inspection method that can prevent misdetection when inspecting a cell stack in which multiple battery cells are stacked during the battery module manufacturing process. [Means for solving the problem]

[0009] A battery module inspection method according to an embodiment of the present invention may include a first vision inspection process for inspecting a cell stack in which a plurality of battery cells are stacked, and inspecting the number and positions of electrode leads provided on each of the plurality of battery cells via a vision camera, and a second vision inspection process for inspecting the number and bending state of electrode leads provided on each of the plurality of battery cells via a vision camera after the first vision inspection process. [Effects of the Invention]

[0010] According to the present invention, when inspecting a cell stack in which a plurality of battery cells are stacked during the manufacturing process of a battery module, automatic vision inspection can be performed using a vision camera to prevent erroneous inspections. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a perspective view showing a battery module inspected by a battery module inspection method according to an embodiment of the present invention; [Figure 2] 1 is an exploded perspective view showing a battery module inspected by a battery module inspection method according to an embodiment of the present invention; [Figure 3] 3 is a front view showing a first vision inspection process in the battery module inspection method according to the embodiment of the present invention. FIG. [Figure 4] 1 is a perspective view of a main part showing a first vision inspection process in a battery module inspection method according to an embodiment of the present invention. FIG. [Figure 5] 1 is a plan view showing an electrode lead photographed by a vision camera during a first vision inspection process of a battery module inspection method according to an embodiment of the present invention. FIG. [Figure 6] 10 is a front view showing a second vision inspection process in the battery module inspection method according to the embodiment of the present invention. FIG. [Figure 7] 1 is a perspective view of a main part illustrating the concept of a second vision inspection process in a battery module inspection method according to an embodiment of the present invention; [Figure 8] 10 is a side view showing a state in which an electrode lead is photographed through a vision camera during the second vision inspection process of the battery module inspection method according to the embodiment of the present invention. FIG. [Figure 9] 10 is a front view showing a third vision inspection process in the battery module inspection method according to the embodiment of the present invention. FIG. [Figure 10]10 is a perspective view of a main part illustrating the concept of a third vision inspection process in the battery module inspection method according to an embodiment of the present invention; FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] The objectives, particular advantages, and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments taken in conjunction with the accompanying drawings. It should be noted that, when referring to components in each drawing, identical components have been given the same reference numerals whenever possible, even when they appear in different drawings. Furthermore, the present invention may be realized in various different forms and is not limited to the embodiments described herein. Furthermore, in describing the present invention, detailed descriptions of related publicly known technologies that may unnecessarily obscure the gist of the present invention will be omitted.

[0013] FIG. 1 is a perspective view showing a battery module to be inspected by a battery module inspection method according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view showing a battery module to be inspected by a battery module inspection method according to an embodiment of the present invention.

[0014] In addition, Figure 3 is a front view showing the first vision inspection process in the battery module inspection method of an embodiment of the present invention, Figure 4 is an oblique view of the main parts showing the first vision inspection process in the battery module inspection method of an embodiment of the present invention, and Figure 6 is a front view showing the second vision inspection process in the battery module inspection method of an embodiment of the present invention.

[0015] 1 to 6, the battery module inspection method according to the embodiment of the present invention includes a first vision inspection process of inspecting the number and positions of electrode leads 20 provided in each of a plurality of battery cells 10 using vision cameras 110 and 120, and a second vision inspection process of inspecting the number and bending state of the electrode leads 20 provided in each of the plurality of battery cells 10 using the vision cameras 110 and 120. The battery module inspection method according to the embodiment of the present invention may further include a third vision inspection process of inspecting the number and positions of the electrode leads 20 by photographing the lower parts of the electrode leads 20 using the vision cameras 110 and 120.

[0016] 1 and 2, a battery module 1 inspected by the battery module inspection method according to an embodiment of the present invention may include a cell stack S in which a plurality of battery cells 10 are stacked, bus bar frames 60, 70 that electrically connect electrode leads 20 of the plurality of battery cells 10, and a module case 30 that accommodates the cell stack S and the bus bar frames 60, 70. The battery module may further include end plates 40, 50 that cover openings on both sides of the module case 30.

[0017] The cell stack S can be formed by stacking a plurality of battery cells 10 containing an electrolyte solution. The battery cell 10 may include an electrode assembly, an electrolyte, and a pouch that houses the electrode assembly and the electrolyte.

[0018] The electrode assembly is a power generating element capable of charging and discharging, and may be formed by alternately stacking electrodes and separators. In this case, the electrodes may include positive and negative electrodes, and the positive electrodes, separators, and negative electrodes may be alternately stacked. Here, the separator separates and electrically insulates the positive and negative electrodes.

[0019] The battery cell 10 may further include an electrode lead 20, one side of which is connected to an electrode of the electrode assembly and the other side of which extends outside the pouch. The electrode lead 20 may include a positive electrode lead 21 connected to the positive electrode and a negative electrode lead 22 connected to the negative electrode.

[0020] FIG. 5 is a plan view showing an electrode lead photographed by a vision camera in the first vision inspection process of the battery module inspection method according to the embodiment of the present invention.

[0021] Referring to Figures 2, 3 to 5, in the first vision inspection process, a cell stack S in which a plurality of battery cells 10 are stacked is inspected, and the number and positions of the electrode leads 20 provided on each of the plurality of battery cells 10 can be inspected via vision cameras 110 and 120.

[0022] The first vision inspection process can be performed before the cell stack S is assembled to the bus bar frames 60,70. In the first vision inspection process, the upper part of the electrode leads 20 inserted into the insulating blocks 150 and 160 is photographed through the vision cameras 110 and 120, so that the number and positions of the electrode leads 20 can be inspected.

[0023] In addition, the first vision inspection process can detect the ends 20a of the electrode leads 20 within a plurality of imaginary rectangular shapes L1, the same number as the number of the electrode leads 20, to confirm their quantity and position. If even one electrode lead 20 is not detected within the plurality of imaginary rectangular shapes L1, it is determined to be defective. If two or more electrode leads 20 are detected within the imaginary rectangular shapes L1, it is determined to be defective due to duplicate insertion. Specifically, for example, the upper portion of the positive electrode lead 21 is photographed with a vision camera, and if one end 21a of the positive electrode lead 21 is located within each of the plurality of imaginary rectangular shapes L1, it is determined to be normal. Defective determination of the negative electrode lead 22 can be performed in the same manner as defective determination of the positive electrode lead 21. In the first vision inspection process, when the electrode leads 20 are inspected via the vision cameras 110 and 120, the electrode leads 20 can be illuminated via the illuminators 130 and 140. Here, the illuminators 130, 140 may be provided as bar illuminators 130, 140.

[0024] In the first vision inspection process, the second vision inspection process, and the third vision inspection process, the electrode lead 20 can be illuminated via the illuminators 130 and 140 from the diagonal direction above the direction in which the electrode lead 20 extends.

[0025] As a result, the first vision inspection process can easily detect any imperfections in the number and position of the stacked battery cells 10 in the cell stack S before assembling the cell stack S and the bus bar frames 60, 70. Therefore, the first vision inspection process can easily inspect whether the cell stack S and the bus bar frames 60, 70 can be assembled before assembling the cell stack S and the bus bar frames 60, 70.

[0026] Fig. 7 is a perspective view of a main part illustrating an example of the concept of the second vision inspection process in the battery module inspection method according to an embodiment of the present invention, and Fig. 8 is a side view illustrating the state in which an electrode lead is photographed by a vision camera in the second vision inspection process of the battery module inspection method according to an embodiment of the present invention. In Fig. 7, the bus bar frame is illustrated in a simplified manner.

[0027] 2, 6, and 8, in the second vision inspection process, the number and bending state of the electrode leads 20 provided on each of the plurality of battery cells 10 can be inspected through the vision cameras 110 and 120.

[0028] In addition, in the second vision inspection process, the front of the electrode leads 20 is photographed via the vision cameras 110, 120 to inspect the number and bending state of the electrode leads 20. Here, the second vision inspection process can be performed after the cell stack S is assembled to the bus bar frames 60, 70. As a result, the second vision inspection process can easily detect incorrect insertion and bending of the electrode leads 20 when assembling the cell stack S to the bus bar frames 60, 70. Furthermore, the second vision inspection process can easily detect assembly defects between the cell stack S and the bus bar frames 60, 70.

[0029] 7 and 8, the method for inspecting the number of electrode leads 20 in the second vision inspection process can confirm the quantity by detecting the ends 20a of the electrode leads 20 within a plurality of imaginary rectangular shapes L2 that is the same as the number of the electrode leads 20. Here, if even one electrode lead 20 is not detected within the plurality of imaginary rectangular shapes L2, it can be determined as defective, and if two or more electrode leads 20 are detected within the imaginary rectangular shapes L2, it can be determined as defective in quantity due to duplicate insertion.

[0030] The method for inspecting the bent state of the electrode lead 20 in the second vision inspection process involves detecting the end 20a of the electrode lead 20 and tracking its length, and if it is detected that the length E of the detected end of the electrode lead 20 is 3.3% or more shorter than the standard length of the end of the electrode lead, it can be determined that the bend is defective. In this case, for example, if the length of the electrode lead 20 is specified as 30 mm, a bend of 2 mm or more can be determined to be defective.

[0031] 6 and 7, in the second vision inspection process, the electrode lead 20 may be illuminated through the illuminators 130 and 140 from a direction opposite to the direction in which the electrode lead 20 extends. In this case, in the second vision inspection process, the axial direction in which the electrode lead 20 extends and the illumination axis of the illuminators 130 and 140 may be coaxial.

[0032] Fig. 9 is a front view showing a third vision inspection process in the battery module inspection method according to an embodiment of the present invention, and Fig. 10 is a perspective view of a main part exemplarily showing the concept of the third vision inspection process in the battery module inspection method according to an embodiment of the present invention. In Fig. 10, a bus bar frame is shown in a simplified schematic view.

[0033] Referring to Figures 2, 9, and 10, in the third vision inspection process, after the cell stack S is assembled into the busbar frames 60, 70, the number and positions of the electrode leads 20 provided on each of the multiple battery cells 10 can be inspected via the vision cameras 110, 120.

[0034] In the third vision inspection process, the lower part of the electrode lead 20 is photographed through the vision cameras 110 and 120, and the number and position of the electrode lead 20 can be inspected.

[0035] In the third vision inspection process, the electrode lead 20 can be illuminated through the illuminators 130 and 140 from a diagonal direction below the direction in which the electrode lead 20 extends.

[0036] Therefore, the third vision inspection process can easily check whether the electrode leads 20 are incorrectly inserted into the bus bar frames 60, 70 or whether there is a defect in the insertion length after the cell stack S is assembled to the bus bar frames 60, 70. As a result, the third vision inspection process can easily detect defects in the assembly state of the cell stack S and the bus bar frames 60, 70.

[0037] In the third vision inspection process, similar to the defect determination method in the first vision inspection process, the quantity and positions of the electrode leads 20 can be confirmed by detecting the ends of the electrode leads 20 within a plurality of imaginary square shapes that is the same as the number of the electrode leads 20. Here, if even one electrode lead 20 is not detected within the plurality of imaginary square shapes, it can be determined to be defective, and if two or more electrode leads 20 are detected within the imaginary square shapes, it can be determined to be defective due to duplicate insertion.

[0038] Meanwhile, the vision cameras 110 and 120 and the illuminators 130 and 140 used in the first, second, and third vision inspection processes can be moved to a fixed position by a moving means.

[0039] The vision cameras 110, 120 and the illuminators 130, 140 can be moved upward based on the electrode lead 20 of the battery cell 10 during the first vision inspection process via the moving means, moved in the coaxial direction based on the electrode lead 20 of the battery cell 10 during the second vision inspection process, and moved downward based on the electrode lead 20 of the battery cell 10 during the third vision inspection process.

[0040] Here, the moving means may include a frame to which the vision cameras 110, 120 and the illuminators 130, 140 are attached, and a rotating unit that rotates the frame. In this case, the rotating unit may include a servo motor that rotates the rotation axis of the rotating unit.

[0041] The battery module inspection method according to the embodiment of the invention configured as described above can prevent erroneous inspection by automatically performing vision inspection via the vision cameras 110 and 120 when inspecting a cell stack S in which multiple battery cells 10 are stacked during the manufacturing process of the battery module 1.

[0042] Although the present invention has been described in detail above with reference to specific embodiments, these are merely for the purpose of specifically explaining the present invention, and the present invention is not limited thereto. It is possible for a person skilled in the art to carry out various modifications within the technical concept of the present invention. The specific scope of protection of the invention will be apparent from the appended claims. [Explanation of symbols]

[0043] 1: Battery module 10: Battery cell 20: Electrode lead 20a: End 21: Positive lead 21a: End 22: Negative electrode lead 30: Module case 40, 50: End plate 60, 70: Bus bar frame 110, 120: Vision camera 130, 140: Illuminators 150, 160: Insulation block S: Cell stack E: Length of the end

Claims

1. a first vision inspection step of inspecting a cell stack in which a plurality of battery cells are stacked, and automatically inspecting the number and positions of electrode leads provided on each of the plurality of battery cells via a vision camera; a second vision inspection process for automatically inspecting the number and bending state of electrode leads provided on each of the plurality of battery cells using a vision camera after the first vision inspection process; Including, the first vision inspection process is performed before assembling the cell stack onto a bus bar frame; the second vision inspection process is performed after the cell stack is assembled onto a bus bar frame, The second vision inspection process includes: detecting an end of the electrode lead and tracking the length of the end; Calculating a ratio of the detected electrode lead end length to a predetermined electrode lead end length; and If the calculated ratio is 3.3% or more, the detected electrode lead is determined to be bent poorly. A battery module inspection method, comprising:

2. In the first vision inspection step, The method of claim 1 , wherein the number and positions of the electrode leads are inspected by photographing an upper portion of the electrode leads inserted into the insulating block using the vision camera.

3. In the second vision inspection step, The battery module inspection method according to claim 1 , wherein the number and bending state of the electrode leads are inspected by photographing a front view of the electrode leads via the vision camera.

4. 10. The battery module inspection method of claim 1, further comprising a third vision inspection process of inspecting the number and positions of electrode leads provided on each of the plurality of battery cells using a vision camera after assembling the cell stack onto the bus bar frame.

5. In the third vision inspection process, The battery module inspection method according to claim 4 , wherein the number and positions of the electrode leads are inspected by photographing the lower portions of the electrode leads via the vision camera.

6. 6. The battery module inspection method of claim 5, wherein in the first vision inspection process, the second vision inspection process, and the third vision inspection process, the electrode leads are illuminated via an illuminator when inspecting the electrode leads via the vision camera.

7. In the first vision inspection step, 7. The battery module inspection method according to claim 6, wherein the electrode leads are illuminated via the illuminator from a diagonal direction above the direction in which the electrode leads extend.

8. In the second vision inspection step, 7. The battery module inspection method according to claim 6, wherein the electrode leads are illuminated by the illuminator in a direction opposite to the direction in which the electrode leads extend.

9. In the third vision inspection process, 7. The battery module inspection method according to claim 6, wherein the electrode leads are illuminated via the illuminator from a diagonal direction below the direction in which the electrode leads extend.

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