CBI inter-bending device with position measurement

Abstract

The present invention provides a negative electrode tab bending device for a jelly roll electrode assembly having positive and negative electrode tabs, the device including: a jig for fixing the jelly roll electrode assembly so that the negative electrode tab is on top; a pressing device for pressing the negative electrode tab from top to bottom; a spindle device for moving the pressing device up and down; and a position measuring unit for measuring the vertical position of the pressing device.

Description

[Technical Field]

[0001] The present invention relates to a CBI in-tab bending device equipped with a position measurement unit, specifically to a CBI in-tab bending device equipped with a position measurement unit that measures the position of a pressing tool used when bending the negative electrode tab at the bottom of a jelly roll electrode assembly by 90 degrees. [Background technology]

[0002] A lithium secondary battery includes a positive electrode coated with a positive electrode active material, a negative electrode coated with a negative electrode active material, an electrode assembly having a separator laminated thereon between the positive electrode and the negative electrode to prevent short circuits and to allow lithium ions (Li-ions) to move, a battery case that houses the electrode assembly, and an electrolyte that is injected into the battery case to allow the lithium ions to move.

[0003] Lithium secondary batteries are classified into cylindrical batteries or prismatic batteries, which have an electrode assembly housed in a cylindrical or prismatic metal case, and pouch batteries, which have an electrode assembly housed in a pouch-shaped case made of aluminum laminate sheet, depending on the shape of the battery case. Cylindrical batteries have the advantages of being relatively large in capacity and structurally safe.

[0004] A cylindrical battery is manufactured by placing a jelly roll electrode assembly, which is formed by winding a positive electrode sheet, a negative electrode sheet, and a separator sheet between the positive electrode sheet and the negative electrode sheet, into a cylindrical battery case and sealing the case. The jelly roll electrode assembly is placed inside a cylindrical can, and the inner bottom of the cylindrical can is welded to the negative electrode tab located at the bottom of the jelly roll electrode assembly.

[0005] Before placing the jelly roll electrode assembly in the cylindrical can, a cylindrical bottom insulator (hereinafter referred to as "CBI") is provided at the bottom of the jelly roll electrode assembly to insulate it from the cylindrical can. The jelly roll electrode assembly is turned over so that the negative tab is on top, and then the negative tab is bent 90 degrees using a pressing tool. Prior to bending, the negative tab (In-Tab) is first aligned to match the position of the pressing tool.

[0006] FIG. 1 is a top view of a conventional CBI inter-venting device.

[0007] Referring to FIG. 1, the negative electrode tab (in-tab) must be aligned before being fed into the CBI in-tab bending machine. After receiving the jelly roll electrode assembly from the previous process and before bending, the negative electrode tab (in-tab) is aligned to the position of the pressing tool. Three rotating devices are shown in FIG. 1. The first rotating device 100 is a rotating device that can accommodate 16 jelly roll electrode assemblies and perform operations. The first rotating device 100 and the second rotating device 200 align the negative electrode tab (in-tab) to the position of the pressing tool. The electrode tab alignment device is a technology known from Patent Documents 4 and 5, etc., but since the present invention uses a jelly roll electrode assembly in which the electrode tabs, specifically the negative electrode tabs, have already been aligned, a description thereof will be omitted.

[0008] When a jelly roll electrode assembly is wound, the negative and positive electrode tabs protrude from the circular top or bottom surface of the wound electrode assembly. However, the protruding positions of the electrode tabs may be at the outermost, middle, or innermost edges of the jelly roll electrode assembly. These positions vary depending on the notching positions of the tabs during electrode assembly manufacturing. The negative and positive electrode tabs may be composed of multiple tabs. When the protruding position of the electrode tab is in the middle, it is called an in-tab. Specifically, the present invention corresponds to the case where there is only one negative electrode tab, which is called an in-tab.

[0009] The aligned jelly roll electrode assembly is then transferred to the final third rotary device 300, where the negative tab is bent 90 degrees by a CBI in-tab bending device. FIG. 1 shows this tool as a spindle tool 310. As mentioned above, the positive and negative tabs of the jelly roll electrode assembly protrude from the top or bottom of the circular wound electrode assembly. The jelly roll electrode assembly is placed vertically with the negative tab facing up, and the negative tab is bent by a pressing tool at the final rotary device 300.

[0010] If the negative electrode tab is vertically positioned, the negative electrode tab may not be bent by the pressing tool that bends from top to bottom, and may be deformed in a zigzag pattern or only partially broken.

[0011] To solve this problem, before the pressing tool presses the in-tab negative electrode tab, the end of the negative electrode tab is bent slightly at an angle as a preliminary step.The pressing tool presses the middle part of the tilted negative electrode tab, naturally bending the entire negative electrode tab 90 degrees.

[0012] The apparatus shown in Figure 1 is capable of continuously working on a large number of jelly roll electrode assemblies, so unless the working conditions are improved, a large number of defective products may be produced.

[0013] The bending angle changes depending on the pressing depth of the pressing tool. If the pressing tool is pressed too lightly, the bending will not be completed and the negative tab will not be bent at 90 degrees. When such a jelly roll electrode assembly is inserted into a cylindrical can, defects will occur during the process of welding the negative tab.

[0014] If the pressing tool presses too deeply, the negative electrode tab itself, which is to be bent, may be crushed. Defects often occur when the electrode tabs are not properly aligned in the preliminary steps, but defects also often occur depending on the pressing depth of the pressing tool.

[0015] Despite these problems, conventional CBI in-tub bending machines do not measure the position of the pressing tool relative to the pressing depth. By measuring the position of the pressing tool relative to the pressing depth and comparing and improving it, product quality can be improved and the reject rate can be reduced, but it seems that this problem was not recognized in the past. In other words, the pressing tool moves up and down using the spindle device, but the position due to this movement was not measured.

[0016] Patent Document 1 discloses a device that places a can 20 with a jelly roll 10 inserted on a transport carrier 30 that is open at the top and bottom, and performs tasks such as aligning the tabs. However, the device does not have a spindle for aligning the jelly roll tabs, nor does it have a height sensor for measuring the position of the spindle.

[0017] Patent Document 2 discloses that the battery includes a lead 3 that connects an electrode group 14 and a sealing plate 2, and that in order to assemble the sealing plate 2 into the opening of a cylindrical battery case 1, an upper spindle 7 descends from the top of the cylindrical battery case 1 to guide the sealing plate 2 into the opening 1a of the battery case for assembly. However, it differs in that it does not have a configuration in which electrode tabs are bent, but rather the technology involves lowering the upper spindle 7 to assemble the sealing plate 2 into the case 1.

[0018] Patent Document 3 discloses that the press device includes a slide position detection means 8 that measures the height of a slide 4 that moves up and down by a slide driving means 2 and performs press processing, but the difference is that this technology is not a technology for bending electrode tabs, but is used in a hydraulic press device.

[0019] As such, no technology has been presented for measuring the position of the pressing depth of the pressing tool separately, and it appears that possible defects could not be recognized. [Prior art documents] [Patent documents]

[0020] [Patent Document 1] Korean Patent No. 10-0486149

[0021] [Patent Document 2] JP 1997-167602 A

[0022] [Patent Document 3] Korean Patent Publication No. 10-2018-0046403

[0023] [Patent Document 4] Korean Patent No. 10-0145206

[0024] [Patent Document 5] Korean Patent No. 10-0148933 Summary of the Invention [Problem to be solved by the invention]

[0025] The present invention has been made to solve the above problems, and aims to provide a CBI in-tab bending device having a position measuring unit that measures the position of a pressing tool used when bending the lower negative tab of a jelly roll electrode assembly 90 degrees, a jelly roll electrode assembly bent by the CBI in-tab bending device, a cylindrical battery including the bent jelly roll electrode assembly, and a method for bending the lower negative tab of a jelly roll electrode assembly 90 degrees using the CBI in-tab bending device. [Means for solving the problem]

[0026] To achieve the above object, the present invention provides a negative electrode tab bending device for a jelly roll electrode assembly having positive and negative electrode tabs, the electrode tab bending device including: a jig for fixing the jelly roll electrode assembly so that the negative electrode tab is on top; a pressing device for pressing the negative electrode tab from top to bottom; a spindle device for moving the pressing device up and down; and a position measuring unit for measuring the vertical position of the pressing device.

[0027] In the present invention, the spindle refers to a device part that moves along a cam and moves up and down, and the negative electrode tab according to the present invention is usually located at the bottom of the cylindrical can.

[0028] The position measuring unit may include a measuring dog attached to the upper surface of the pressing tool and a displacement sensor that measures the height of the measuring dog, and the displacement sensor may be fixed to a separate bracket.

[0029] The displacement sensor may be a laser displacement sensor. A laser displacement sensor emits a laser from a light projecting portion of the sensor and reads the displacement through the reflected laser. However, the displacement sensor is not limited to a laser displacement sensor as long as it has the function of measuring displacement. The negative electrode tab is an in-tab.

[0030] When the pressing tool presses the negative electrode tab, it may press a side surface of the middle portion of the negative electrode tab. Before the pressing tool presses the negative electrode tab, at least a portion of the negative electrode tab is in an obliquely deformed state. This may be performed by a device provided in the previous step.

[0031] When the jelly roll electrode assembly is fixed in the jig, the negative electrode tab may be aligned with the pressing surface of the pressing tool, and the alignment may be performed by an in-tab alignment device provided in the previous step.

[0032] The present invention also provides a method for bending a negative electrode tab of a jelly roll electrode assembly using the electrode tab bending device according to any one of claims 1 to 7, including a first step of fixing the jelly roll electrode assembly with the jig so that the negative electrode tab is on the upper side, and a second step of pressing the negative electrode tab from above downward with the pressing tool, wherein the second step is performed simultaneously with the step of measuring the vertical position of the pressing tool using the position measuring unit.

[0033] The present invention also provides a jelly roll electrode assembly in which the negative electrode tab is bent by an electrode tab bending device.

[0034] The present invention also provides a cylindrical battery including the jelly roll electrode assembly according to the present invention.

[0035] Furthermore, the present invention can provide a means for solving problems by arbitrarily combining the means for solving problems described above. [Effects of the Invention]

[0036] The present invention provides a negative electrode tab bending device for a jelly roll electrode assembly having positive and negative electrode tabs, the electrode tab bending device including: a jig that fixes the jelly roll electrode assembly so that the negative electrode tab is on top; a pressing device that presses the negative electrode tab from top to bottom; a spindle device that moves the pressing device up and down; and a position measuring unit that measures the vertical position of the pressing device.

[0037] The present invention has the effect of reducing the defect rate in CBI in-tab bending by measuring the position of the pressing tool in the negative electrode tab bending device. [Brief explanation of the drawings]

[0038] [Figure 1] 1 is a top view of a conventional CBI inter-venting device; FIG.

[0039] [Figure 2] 1 is a top view of a CBI inter-vention device according to the present invention; FIG.

[0040] [Figure 3] 1 is a schematic diagram showing displacement measurement of a pressing tool of a CBI in-tub bending device according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0041] Hereinafter, with reference to the accompanying drawings, a detailed description will be given of an embodiment of the present invention that will enable a person skilled in the art to easily carry out the present invention. In describing the operation principle of the embodiment of the present invention in detail, detailed description of related well-known functions or configurations will be omitted if it is determined that such detailed description may unnecessarily obscure the gist of the present invention.

[0042] Furthermore, the same reference numerals are used throughout the drawings for parts having similar functions and actions. Throughout the specification, when a part is said to be connected to another part, this includes not only a direct connection but also an indirect connection via another element therebetween. Furthermore, unless otherwise specified, "including a certain element" does not mean that other elements are excluded, but that other elements may also be included.

[0043] Furthermore, descriptions that limit or add specific elements are applicable to all inventions and are not limited to a particular invention unless otherwise specified.

[0044] Furthermore, throughout the description of the present invention and the claims, the singular includes the plural unless otherwise stated.

[0045] Furthermore, throughout the description of the present invention and the claims, unless otherwise specified, "or" includes "and." Therefore, "including A or B" means three cases: including A, including B, or including both A and B.

[0046] Furthermore, all numerical ranges include both endpoints and all intermediate values ​​therebetween unless expressly stated to the contrary.

[0047] The present invention will now be described in detail with reference to the accompanying drawings, in which: FIG.

[0048] FIG. 2 is a top view of the CBI in-tube bending apparatus according to the present invention, and FIG. 3 is a schematic diagram showing the displacement measurement of the pressing tool of the CBI in-tube bending apparatus according to the present invention.

[0049] FIG. 1 is a top view of a conventional CBI inter-bending device, and FIG. 2 shows the same as FIG. 1, further including a measuring dog 320, a displacement sensor 330, and a bracket 400. As shown in FIG.

[0050] The spindle tool 310 referred to in FIGS. 1 and 3 includes a spindle 315 and a pressing device 340. Referring to FIG. 3, the present invention relates to a device for bending a negative electrode tab 12 of a jelly roll electrode assembly 10 having a positive electrode tab 14 and a negative electrode tab 12. The device includes a jig 500 that fixes the jelly roll electrode assembly 10 so that the negative electrode tab 12 is on top, a pressing device 340 that presses the negative electrode tab 12 from top to bottom, a spindle 315 that moves the pressing device 340 up and down, and a position measuring unit 600 that measures the vertical position of the pressing device 340. The position measuring unit 600 includes a measuring dog 320 and a displacement sensor 330. In the present invention, the spindle 315 refers to a device that moves up and down along a cam, and the negative electrode tab 12 according to the present invention is typically located at the bottom of a cylindrical can.

[0051] The position measuring unit 600 includes a measuring dog 320 attached to the upper surface of the pressing tool 340 and a displacement sensor 330 that measures the height of the measuring dog 320. The displacement sensor 330 is fixed to a separate bracket 400. The displacement sensor 330 is a laser displacement sensor that emits a laser from a light emitting portion of the sensor and reads the displacement based on the reflected laser. Meanwhile, the negative electrode tab 12 is an in-tab.

[0052] The left (lower) side of FIG. 3 is a schematic diagram before the pressing tool 340 presses the negative electrode tab 12, and the right (upper) side of FIG. 3 is a schematic diagram after the pressing tool 340 presses the negative electrode tab 12. The right side of FIG. 3 overlaps the pressing tool 340 and the negative electrode tab 12 to facilitate understanding. Position measurement values ​​D1 and D2 represent the positions of the respective pressing tools 340 and provide quantitative data on the actual pressure applied by the pressing tools. The difference in position measurement values ​​alone makes it easy to determine whether the negative electrode tab was bent properly, identify only the device where a defect occurs, and determine the range of proper bending, thereby significantly improving quality. The CBI in-tab bending device according to the present invention has already been applied to an actual cylindrical battery manufacturing process, making a significant contribution to improving product quality.

[0053] Those skilled in the art will be able to make various applications and modifications within the scope of the present invention based on the above content. [Explanation of symbols]

[0054] 10 Jelly roll electrode assembly

[0055] 12 Negative electrode tab

[0056] 14 Positive electrode tab

[0057] 100 First rotating device

[0058] 200 Second Rotating Device

[0059] 300 Third Rotating Device

[0060] 310 Spindle Tool

[0061] 315 Spindle

[0062] 320 Measuring Dog

[0063] 330 Displacement Sensor

[0064] 340 Pressing Instruments

[0065] 400 bracket

[0066] 500 jig

[0067] 600(320, 330) Position measurement section

[0068] D1, D2 position measurement values

Claims

1. A negative electrode tab bending device for a jelly roll electrode assembly having positive and negative electrode tabs, a jig for fixing the jelly roll electrode assembly so that the negative electrode tab faces upward; a pressing tool that presses the negative electrode tab from above downward; a spindle device for moving the pressing tool up and down; a position measuring unit for measuring the vertical position of the pressing tool; An electrode tab bending device comprising:

2. The position measurement unit a measuring dog attached to the upper surface of the pressing tool; a displacement sensor for measuring the height of the measuring dog; The electrode tab bending device of claim 1 , comprising:

3. The electrode tab bending device according to claim 2 , wherein the displacement sensor is fixed to a separate bracket.

4. The electrode tab bending device according to claim 2 , wherein the displacement sensor is a laser displacement sensor.

5. 2. The electrode tab bending device according to claim 1, wherein the negative electrode tab is an in-tab.

6. The electrode tab bending device according to claim 1 , wherein the pressing tool presses a side surface of a middle portion of the negative electrode tab when pressing the negative electrode tab.

7. 2. The electrode tab bending device according to claim 1, wherein when the jelly roll electrode assembly is fixed in the jig, the negative electrode tab is fixed in the jig in a state where the direction of the negative electrode tab is aligned so as to coincide with the pressing surface of the pressing tool.

8. a first step of fixing the jelly roll electrode assembly in the jig so that the negative electrode tab faces upward; a second step of pressing the negative electrode tab from above downward with the pressing tool; A method for bending a negative electrode tab of a jelly roll electrode assembly using the electrode tab bending apparatus according to any one of claims 1 to 7, comprising: The second step is performed simultaneously with the step of measuring the vertical position of the pressing tool using the position measuring unit.

9. A jelly roll electrode assembly, wherein the negative electrode tab is bent by the electrode tab bending device according to any one of claims 1 to 7.

10. A cylindrical battery comprising the jellyroll electrode assembly of claim 9.

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