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 on January 27, 2022 and Korean Patent Application No. 10-2023-0010161 filed on January 26, 2023, and all contents disclosed in the documents of said Korean patent applications are incorporated by reference into this specification. The present invention relates to a method for inspecting a battery module. [Background technology]

[0002] Unlike primary batteries, secondary batteries can be recharged, and they have the potential to be small and have large capacity, so they have been the subject of much research and development in recent years. As technological development and demand for mobile devices increases, the demand for secondary batteries as an energy source is rapidly increasing.

[0003] Secondary batteries are classified into coin type batteries, cylindrical type batteries, prismatic type batteries, and pouch type batteries according to 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 having a laminated structure of electrodes and separators.

[0004] Secondary batteries have attracted much attention not only for use in mobile devices such as mobile phones, digital cameras, and notebook computers, but also as energy sources for power plants such as electric bicycles, electric cars, and hybrid electric cars.

[0005] Small devices such as mobile phones and cameras use small battery packs containing one battery cell, while medium- to large-sized devices such as notebook computers and electric cars 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 contained in the battery pack can be set in various ways depending on the required output voltage or charge / discharge capacity.

[0006] Meanwhile, when a battery pack is constructed by connecting a plurality of battery cells in series / parallel, a method is generally used in which a battery module consisting of at least one battery cell is first constructed, and the battery pack is constructed by adding other components to the at least one battery module. The number of battery modules included in the battery pack or the number of battery cells included in the battery module can be set in various ways according to the required output voltage or charge / discharge capacity. The battery module thus constructed includes a plurality of battery cells stacked on top of each other, and a busbar frame that electrically connects the electrode leads of the plurality of battery cells.

[0007] Previously, the inspection of the ICB busbar frame assembly was done visually by the workers before and after assembly. This resulted in mis-inspection due to human inspection error caused by the worker-dependent inspection. In addition, the labor cost increased due to the progress of manual inspection of the ICB busbar frame assembly. 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 a plurality of battery cells are stacked during the manufacturing process of the battery module. [Means for solving the problem]

[0009] A method for inspecting a battery module 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. Effect 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 inspection. [Brief description 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; [Diagram 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; [Diagram 3] 2 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 portion showing a first vision inspection process in a battery module inspection method according to an embodiment of the present invention. FIG. [Diagram 5] 1 is a plan view showing a state in which an electrode lead is photographed through 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] 11 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 portion illustrating an example of the concept of a second vision inspection process in a battery module inspection method according to an embodiment of the present invention. FIG. [Figure 8] 11 is a side view showing a state in which an electrode lead is photographed through a vision camera during a second vision inspection process of a battery module inspection method according to an embodiment of the present invention. FIG. [Figure 9] 11 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]1 is a perspective view of a main part illustrating an example of the concept of a third vision inspection process in a battery module inspection method according to an embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The object, particular advantages, and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments in conjunction with the accompanying drawings. In this specification, when referring to components in each drawing, it should be noted that the same components are numbered as much as possible even when they are displayed in other drawings. In addition, the present invention may be realized in various different forms, and is not limited to the embodiments described herein. In describing the present invention, detailed descriptions of related 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 a key portion 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 method for inspecting a battery module according to an embodiment of the present invention includes a first vision inspection process for inspecting the number and positions of electrode leads 20 provided in each of a plurality of battery cells 10 through vision cameras (Vision Cameras) 110, 120, and a second vision inspection process for inspecting the number and bending state of the electrode leads 20 provided in each of the plurality of battery cells 10 through the vision cameras 110, 120. In addition, the method for inspecting a battery module according to an embodiment of the present invention may further include a third vision inspection process for inspecting the number and positions of the electrode leads 20 by photographing the lower parts of the electrode leads 20 through the vision cameras 110, 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. In addition, 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 form a stack in which a plurality of battery cells 10 containing an electrolyte are stacked. The battery cell 10 may include an electrode assembly and an electrolyte, and a pouch that houses the electrode assembly and the electrolyte therein.

[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 a positive electrode and a negative electrode, and the positive electrode, the separator, and the negative electrode may be alternately stacked. Here, the separator separates the positive electrode and the negative electrode to electrically insulate them.

[0019] The battery cell 10 may further include an electrode lead 20 having one side connected to an electrode of the electrode assembly and the other side extending 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 a state in which an electrode lead is 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 and 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 step can be performed prior to assembly of the cell stack S to the busbar 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, in the first vision inspection process, the end 20a of the electrode lead 20 can be detected within a plurality of imaginary rectangular shapes L1, which is the same as the number of the electrode leads 20, to confirm the quantity and position. Here, if even one electrode lead 20 is not detected within the plurality of imaginary rectangular shapes L1, it can be determined that the electrode lead 20 is defective, and if two or more electrode leads 20 are detected within the imaginary rectangular shape L1, it can be determined that the electrode lead 20 is defective due to overlapping insertion. In this case, as a specific example, the upper part of the positive electrode lead 21 is photographed by a vision camera, and if the end 21a of the positive electrode lead 21 is located one by one within each of the plurality of imaginary rectangular shapes L1, it can be determined that the electrode lead 20 is normal. The defect determination of the negative electrode lead 22 can be performed in the same manner as the defect determination of the positive electrode lead 21. In the first vision inspection process, when the electrode lead 20 is inspected via the vision cameras 110 and 120, the electrode lead 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 an upper diagonal direction relative to the direction in which the electrode lead 20 extends.

[0025] As a result, the first vision inspection process can easily detect defects in the number and positions 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 or not 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 a concept of a 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 a 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, a 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 in 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 busbar frames 60, 70. As a result, the second vision inspection process can easily detect the occurrence of incorrect insertion and bending defects of the electrode leads 20 when assembling the cell stack S to the busbar frames 60, 70. Furthermore, the second vision inspection process can easily detect assembly defects between the cell stack S and the busbar frames 60, 70.

[0029] 7 and 8, the method of inspecting the quantity of electrode leads 20 in the second vision inspection process can detect 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 to confirm the quantity. 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 quantity due to duplicated insertion.

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

[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 extension direction of the electrode lead 20. In this case, in the second vision inspection process, the axial direction in which the electrode lead 20 extends may be coaxial with the illumination axis of the illuminators 130 and 140.

[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 manner.

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

[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 makes it possible to easily check whether the electrode leads 20 are erroneously inserted into the bus bar frames 60, 70 and 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 makes it possible to 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, similarly to the defect determination method in the first vision inspection process, the ends of the electrode leads 20 can be detected within a plurality of imaginary rectangular shapes equal in number to the plurality of electrode leads 20 to confirm the quantity and position. Here, if even one electrode lead 20 is not detected within the plurality of imaginary rectangular shapes, it can be determined as defective, and if two or more electrode leads 20 are detected within the imaginary rectangular shapes, it can be determined as defective due to duplicated insertion.

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

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

[0040] Here, the moving means may include a frame on 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 shaft 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, 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, this is for the purpose of specifically explaining the present invention, and the present invention is not limited thereto. It is possible to carry out various embodiments within the technical concept of the present invention by a person having ordinary skill in the art. Moreover, the specific scope of protection of the invention will become 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 lead 30: Module case 40, 50: End plate 60, 70: Busbar frame 110, 120: Vision camera 130, 140: Illumination equipment 150, 160: Insulation block S: Cell stack E: Length of end

Claims

1. a first vision inspection step of inspecting a cell stack in which a plurality of battery cells are stacked, and inspecting the number and positions of electrode leads provided in each of the plurality of battery cells via a vision camera; a second vision inspection process for inspecting the number and bending state of electrode leads provided in each of the plurality of battery cells through a vision camera after the first vision inspection process; A battery module inspection method comprising:

2. the first vision inspection step is performed before the cell stack is assembled onto a bus bar frame; The method of claim 1 , wherein the second vision inspection step is performed after the cell stack is assembled onto a bus bar frame.

3. In the first vision inspection process, The method of claim 1 , further comprising the step of photographing an upper portion of the electrode leads inserted into the insulating block via the vision camera to inspect the number and positions of the electrode leads.

4. In the second vision inspection process, The method for inspecting a battery module according to claim 1 , further comprising the step of photographing a front view of the electrode leads via the vision camera to inspect the number and bending state of the electrode leads.

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

6. In the third vision inspection process, The method of inspecting a battery module according to claim 5 , further comprising the step of inspecting the number and positions of the electrode leads by photographing lower portions of the electrode leads via the vision camera.

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

8. In the first vision inspection process, 8. The method for inspecting a battery module according to claim 7, wherein the electrode leads are illuminated via the illuminator from a diagonal direction above a direction in which the electrode leads extend.

9. In the second vision inspection process, 8. The method for inspecting a battery module according to claim 7, wherein the electrode leads are illuminated via the illuminator from a direction opposite to a direction in which the electrode leads extend.

10. In the third vision inspection process, 8. The method for inspecting a battery module according to claim 7, wherein the electrode leads are illuminated via the illuminator from a diagonal direction below a direction in which the electrode leads extend.

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