Laminating apparatus including a press roller configured such that its pressing force is adjustable, and electrode assembly manufactured using the same

Abstract

The present invention relates to a laminating apparatus for manufacturing an electrode assembly, and more particularly, to a laminating apparatus including a pressing roller configured to press electrodes constituting an electrode assembly, a rotation shaft configured to rotate the pressing roller, a pressing cylinder configured to adjust a pressing force applied to the pressing roller, and a thickness measuring sensor configured to measure a thickness of one of the electrodes, thereby ensuring adhesion between the electrodes constituting the electrode assembly even in the presence of a thickness deviation between electrode mixture layers.

Description

Technical Field

[0001] This application claims the benefit of priority to Korean Patent Application No. 2021-0016895, filed on February 5, 2021, the entire disclosure of which is incorporated herein by reference.

[0002] This invention relates to a laminating apparatus including a pressing roller configured to adjust its pressing pressure, and to an electrode assembly manufactured using the laminating apparatus. More specifically, the invention relates to a laminating apparatus including a pressing roller and an electrode assembly manufactured using the laminating apparatus, the pressing roller being configured to adjust its pressing pressure to prevent non-uniform adhesion between the electrodes due to thickness variations between the electrodes constituting a dual cell. Background Technology

[0003] With the increasing capacity and accelerating improvement in energy density of lithium-ion batteries, they have been used as a power source for medium and large-sized devices such as vehicles or energy storage systems, as well as small devices such as portable electronic devices.

[0004] Lithium-ion batteries can be manufactured by housing an electrode assembly configured to have a positive electrode, a separator, and a negative electrode stacked in sequence within a battery casing and sealing the battery casing hermetically.

[0005] The electrode assembly includes: a single-cell configured to have a first electrode and a separator stacked; a mono-cell configured to have a first electrode, a separator, and a second electrode stacked; and a bi-cell configured to have a first electrode, a separator, a second electrode, a separator, and a third electrode stacked.

[0006] Each electrode constituting an electrode assembly is manufactured by applying an electrode mixture to one or both opposite surfaces of a thin current collector made of copper, aluminum, or nickel and then drying and pressing it.

[0007] Electrodes manufactured in this way undergo a process of stacking and laminating electrodes with diaphragms inserted between them, thereby bonding the electrodes together. However, when thickness variations occur between the electrode mixture layers applied to the electrodes, the electrodes will bond unevenly to each other.

[0008] Related to this, Figure 1 This is a diagram illustrating a dual-cell lamination process using conventional lamination equipment.

[0009] Reference Figure 1The electrode assembly is a dual-cell battery configured with a first electrode 110, a separator 140, a second electrode 120, and a third electrode 130 stacked sequentially. The electrode mixture layer 122 on the two opposing surfaces of the electrode current collector 121 applied to the second electrode 120 has an uneven thickness. The left side of each electrode mixture layer is thinner, while the right side of each electrode mixture layer is thicker.

[0010] A pair of pressing rollers 150 are positioned above the first electrode 110 and below the third electrode 130 to press the electrode assembly. At this time, the pressing rollers 150 apply uniform pressure to the entire surface of the first electrode 110 and the third electrode 130 that abut against the pressing rollers. As a result, the left side of the electrode mixture layer 122 of the second electrode is difficult to make close contact with the left side of the first electrode 110 and the left side of the third electrode 130.

[0011] As mentioned above, if adhesion is not achieved at the interface between electrodes, it will lead to non-uniform degradation of the electrodes, making it difficult for lithium ions to move, which will increase the resistance and thus reduce the performance of the lithium secondary battery.

[0012] Furthermore, in the manufacturing process of stacked folded electrode assemblies, dual cells must be arranged side by side on a long sheet-type separator, and an electrode separated from one dual cell may be set together with another dual cell.

[0013] This problem can occur when the thickness of the second electrode, which is located in the middle of the electrodes constituting the dual cell, is uneven, due to poor adhesion between the first and second electrodes and between the third and second electrodes.

[0014] Therefore, a technique is needed to ensure the bonding force between all electrodes when the thickness of the electrode mixture layer of the second electrode, which is located in the middle of the electrodes constituting the dual cell, is uneven. Summary of the Invention

[0015] Technical issues

[0016] The present invention was made in view of the above problems. The object of the present invention is to provide a lamination apparatus including a pressing roller and an electrode assembly manufactured using the lamination apparatus, wherein the pressing roller is configured to have an adjustable pressing force to prevent a decrease in the adhesion between the electrodes due to thickness variations between the electrode mixture layers constituting the dual cell.

[0017] Technical solution

[0018] To achieve the above objectives, the laminating apparatus according to the present invention is a laminating apparatus for manufacturing electrode assemblies, comprising: a pressing roller configured to press electrodes constituting the electrode assembly; a rotating shaft configured to rotate the pressing roller; a pressing cylinder configured to adjust the pressing force applied to the pressing roller; and a thickness measuring sensor configured to measure the thickness of an electrode mixture layer of the electrodes.

[0019] In the lamination apparatus according to the invention, the pressing cylinder may include a first pressing cylinder and a second pressing cylinder respectively coupled to opposite ends of the rotating shaft.

[0020] In the laminating apparatus according to the invention, the pressing force applied by the first pressing cylinder and the pressing force applied by the second pressing cylinder are different from each other.

[0021] In the lamination apparatus according to the present invention, the thickness measuring sensor may include a first thickness measuring sensor and a second thickness measuring sensor respectively disposed at opposite ends of the electrode.

[0022] The laminating apparatus according to the invention may further include a controller configured to control the pressing force of the pressing cylinder when a difference arises between the thickness of the electrode mixture layer of the electrode as measured by the first thickness measuring sensor and the thickness of the electrode mixture layer of the electrode as measured by the second thickness measuring sensor.

[0023] In the lamination apparatus according to the invention, when a difference arises between the thickness of the electrode mixture layer of the electrode as measured by the first thickness measuring sensor and the thickness of the electrode mixture layer of the electrode as measured by the second thickness measuring sensor, the pressing roller can press the electrode more forcefully at the location where the electrode thickness is smaller.

[0024] In the lamination apparatus according to the invention, the electrode assembly may be a dual-cell battery configured to have a structure in which a first electrode, a separator, a second electrode, a separator, and a third electrode are stacked.

[0025] The lamination apparatus according to the invention may further include: a first electrode supply unit; a second electrode supply unit; and a third electrode supply unit, wherein the thickness measuring sensor is capable of measuring the thickness of the electrode mixture layer of the second electrode supplied from the second electrode supply unit.

[0026] In the lamination apparatus according to the invention, each of the electrodes may be a double-sided electrode formed by coating two opposite surfaces of an electrode current collector with an electrode mixture, and the lamination apparatus may be disposed on each of the upper and lower surfaces of the electrode assembly.

[0027] In the lamination apparatus according to the invention, the thickness measurement sensor may include: an irradiation section configured to irradiate beta rays capable of passing through the electrode; and a receiving section configured to sense the beta rays irradiated by the irradiation section, wherein the irradiation section may be disposed on either the upper surface or the lower surface of the electrode, and the receiving section may be disposed on the other surface.

[0028] In the lamination apparatus according to the invention, the pressing force applied to the first and second ends of the upper pressing roller disposed on the upper surface of the electrode can be set independently of the pressing force applied to the first and second ends of the lower pressing roller disposed on the lower surface of the electrode.

[0029] In the laminating apparatus according to the invention, the pressing roller may be configured to be heated.

[0030] The present invention provides an electrode assembly manufactured using the lamination equipment. Specifically, the electrode assembly may be a dual-cell battery configured to have a structure in which a first electrode, a separator, a second electrode, a separator, and a third electrode are sequentially stacked, and the first electrode and the second electrode are bonded to each other across their entire periphery, and the second electrode and the third electrode are bonded to each other across their entire periphery.

[0031] Furthermore, the present invention can provide various combinations of the above-mentioned solutions.

[0032] Beneficial effects

[0033] As is evident from the above description, in this invention, the pressing force of the pressing roller configured to press the dual batteries is adjustable, thus ensuring adhesion between the electrodes by increasing the pressing force of the pressing roller in the portion where the electrode mixture layer is less thick.

[0034] In addition, a thickness measurement sensor can be used to measure the thickness of the electrode mixture layer of the second electrode located in the middle of the dual cell, thereby forming an adhesive surface at the entire interface between the first electrode and the separator and at the entire interface between the separator and the second electrode.

[0035] Furthermore, the pressing force applied to the pressing roller positioned above the first electrode of the dual battery and the pressing roller positioned below the third electrode can be adjusted individually by the first pressing cylinder and the second pressing cylinder, which are connected to opposite ends of the rotating shaft of the pressing roller, thereby ensuring the adhesion between the first electrode and the second electrode and between the third electrode and the second electrode, even if there is a thickness deviation between the electrode mixture layers formed on the opposite two surfaces of the second electrode.

[0036] Furthermore, the pressing roller is configured such that the temperature of the pressing roller can be increased, thereby further increasing the adhesion between the electrodes.

[0037] Due to the increased adhesion between the electrodes as described above, a battery cell with low resistance can be provided. Furthermore, non-uniform degradation of the electrode assembly is prevented, thereby providing a battery cell with increased lifespan.

[0038] Furthermore, when manufacturing stacked folded electrode assemblies, dual cells can be arranged side by side on the separator, thereby reducing incorrect dual cell placement and thus ensuring the productivity of the electrode assembly. Attached Figure Description

[0039] Figure 1 This is a diagram illustrating a dual-cell lamination process using conventional lamination equipment.

[0040] Figure 2 This is a front view showing the state of laminating a dual-cell battery using the lamination apparatus according to the invention.

[0041] Figure 3 This is a side view showing the state of laminating a dual battery using a lamination apparatus according to one embodiment.

[0042] Figure 4 It is shown to Figure 3 Add a perspective view of the controller status to the laminating equipment.

[0043] Figure 5 This is a side view showing the state of laminating a dual battery using a lamination device according to another embodiment.

[0044] Figure 6 It is shown to Figure 5 Add a perspective view of the controller status to the laminating equipment.

[0045] Figure 7 These are vertical cross-sectional and plan views of the dual-cell battery manufactured based on the experimental example. Detailed Implementation

[0046] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, enabling those skilled in the art to readily implement these preferred embodiments. However, in describing the working principle of the preferred embodiments of the present invention, detailed descriptions of known functions and structures incorporated herein may obscure the main points of the invention, and such descriptions will be omitted.

[0047] Furthermore, the same reference numerals will be used throughout the accompanying drawings to denote components performing similar functions or operations. Where, throughout the application, one component is referred to as being connected to another component, that one component may not only be directly connected to the other component, but also indirectly connected to the other component via another component. Moreover, including an element does not imply the exclusion of other elements, but rather the inclusion of further elements, unless otherwise stated.

[0048] Furthermore, unless otherwise specified, the description of elements by limitation or addition can be applied to all inventions and does not limit any particular invention.

[0049] Furthermore, in the specification of this invention and the claims of this application, unless otherwise stated, the singular form is intended to include the plural form.

[0050] Furthermore, in the specification of this invention and the claims of this application, unless otherwise stated, "or" includes "and". Therefore, "including A or B" refers to three cases: including A, including B, and including both A and B.

[0051] In the following, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0052] Figure 2 This is a front view showing the state of laminating a dual-cell battery using the lamination apparatus according to the invention.

[0053] Reference Figure 2 Pressing rollers 251 are provided above and below the electrode assembly.

[0054] The electrode assembly is a dual cell configured to have a first electrode 210, a separator 240, a second electrode 220, and a third electrode 230 stacked sequentially. The first electrode 210 and the third electrode 230 are electrodes with the same polarity, and the second electrode 220 is an electrode with a polarity different from that of the first electrode 210 and the third electrode 230.

[0055] Each of the first electrode 210, the second electrode 220, and the third electrode 230 is a double-sided electrode on two opposing surfaces of an electrode mixture layer applied to an electrode current collector.

[0056] The thickness of each electrode mixture layer 222 on the upper and lower surfaces of the electrode current collector 221 applied to the second electrode 220 is uneven. The left side of each electrode mixture layer is relatively thin, while the right side of each electrode mixture layer is relatively thick.

[0057] In this case, when Figure 1 When the electrode assembly is pressed with the rotating shafts 252 of the pressing rollers 251 arranged parallel to each other, it is difficult to remove the gaps between the first electrode 210 and the second electrode 220, and between the third electrode 230 and the second electrode 220, on the left side where the thickness of each electrode mixture layer 222 is relatively small. As a result, unadhesive portions are produced on the left side portions of the first electrode 210 and the second electrode 220, and on the left side portions of the third electrode 230 and the second electrode 220.

[0058] Therefore, in this invention, the first pressing cylinder 253 and the second pressing cylinder 263, which are configured to be independently controlled, are coupled to the opposite ends of each rotating shaft 252 configured to rotate the pressing roller 251.

[0059] Specifically, the pressing force applied by the first pressing cylinder 253 and the pressing force applied by the second pressing cylinder 263 may be different from each other. The first pressing cylinder 253 is disposed adjacent to the portion of each electrode mixture layer with a relatively smaller thickness, and the second pressing cylinder 263 is disposed adjacent to the portion of each electrode mixture layer with a relatively larger thickness.

[0060] When the pressing force applied by the first pressing cylinder 253 is greater than the pressing force applied by the second pressing cylinder 263, the first electrode 210 and the third electrode 230 can be strongly pressed in the direction toward the second electrode 220. Therefore, the electrodes can be completely adhered to each other at the left portion where the thickness of each electrode mixture layer 222 is relatively small and the right portion where the thickness of each electrode mixture layer 222 is relatively large.

[0061] Figure 3 This is a side view showing the state of laminating a dual-cell battery using a lamination apparatus according to one embodiment. Figure 4 It is shown to Figure 3 Add a perspective view of the controller status to the laminating equipment.

[0062] Reference Figure 3 and Figure 4 The lamination apparatus according to the invention, configured to manufacture dual batteries, includes: a pressing roller 351 configured to press electrodes constituting an electrode assembly; a rotating shaft 352 configured to rotate the pressing roller 351; a first pressing cylinder 353 and a second pressing cylinder 363 configured to adjust the pressing force applied to the pressing roller 351; and a first thickness measuring sensor 381 and a second thickness measuring sensor 382 configured to measure the thickness of one of the electrodes.

[0063] The laminating apparatus further includes: a first electrode supply unit configured to supply a first electrode 310; a second electrode supply unit configured to supply a second electrode 320; and a third electrode supply unit configured to supply a third electrode 330, wherein a thickness measuring sensor measures the thickness of the second electrode 320 supplied from the second electrode supply unit.

[0064] The electrode assembly is a dual-cell battery configured to sequentially stack a first electrode 310, a separator 340, a second electrode 320, a separator 340, and a third electrode 330. The first electrode 310 is configured to form an electrode mixture layer 312 on two opposing surfaces of the electrode current collector 311, the second electrode 320 is configured to form an electrode mixture layer 322 on two opposing surfaces of the electrode current collector 321, and the second electrode 330 is configured to form an electrode mixture layer 332 on two opposing surfaces of the electrode current collector 331.

[0065] The first electrode 310 and the third electrode 330 are electrodes with the same polarity, while the second electrode 320 is an electrode with a polarity different from that of the first electrode 310 and the third electrode 330. That is, when the first electrode and the third electrode are positive, the second electrode is negative. When the first electrode and the third electrode are negative, the second electrode is positive.

[0066] The diaphragm 340 is attached to the outer surface of the electrode mixture layer 312 of the first electrode 310 facing the second electrode 320, and the first electrode 310 and the diaphragm 340 are cut into unit electrodes by a cutter 390 in a step prior to lamination.

[0067] The diaphragm 340 is attached to the outer surface of the electrode mixture layer 332 of the third electrode 330 facing the second electrode 320, and the third electrode 330 and the diaphragm 340 are cut into unit electrodes by a cutter 390 in a step prior to lamination.

[0068] The outer surface of the electrode mixture layer 322 of the second electrode 320 is not attached to the diaphragm 340, and the second electrode 320 is cut into unit electrodes by a cutter 390 in the step prior to lamination.

[0069] The pressing cylinder includes a first pressing cylinder 353 and a second pressing cylinder 363 respectively coupled to opposite ends of the rotating shaft 352, and the pressing cylinders can be controlled individually so that the pressing force applied to the pressing roller is different from each other.

[0070] The thickness of the electrode mixture layer 322 of the second electrode 320 may be non-uniform. A first thickness measuring sensor 381 and a second thickness measuring sensor 382, ​​configured to measure the thickness of the electrode mixture layer, are respectively disposed at opposite ends of the second electrode 320. Specifically, the first thickness measuring sensor 381 and the second thickness measuring sensor 382 are respectively disposed at opposite ends of the second electrode in the y-axis direction, where the y-axis direction is perpendicular to the electrode's movement direction x.

[0071] To ensure adhesion between the electrodes constituting the dual cell, identifying the thickness deviation of the second electrode allows us to determine the dimensions of the gaps between the first and second electrodes, and between the third and second electrodes. Therefore, checking the thickness deviation of the second electrode is crucial.

[0072] Each of the first thickness measuring sensor 381 and the second thickness measuring sensor 382 may consist of an upper sensor located above the second electrode and a lower sensor located below the second electrode. Beta rays emitted from the lower sensor pass through the second electrode and reach the upper sensor. The greater the loading of the electrode mixture layer of the second electrode, the smaller the remaining amount of beta rays reaching the upper sensor. Therefore, the thickness of the electrode mixture layer of the second electrode can be measured by calculating the loading of the electrode mixture layer based on the remaining amount of beta rays measured by the upper sensor.

[0073] When a difference arises between the thickness of the electrode mixture layer measured by the first thickness measuring sensor 381 and the thickness of the electrode mixture layer measured by the second thickness measuring sensor 382, ​​a difference arises between the pressing force applied by the first pressing cylinder 353 and the pressing force applied by the second pressing cylinder 363. The pressing cylinder located on the side with the smaller electrode mixture layer thickness applies a stronger pressing force to the pressing roller. As a result, the portions of the first and third electrodes adjacent to the smaller thickness portion of the electrode mixture layer of the second electrode are pressed more strongly in the direction toward the second electrode, thus increasing the adhesion between the first and second electrodes and the adhesion between the third and second electrodes.

[0074] In one specific example, the laminating equipment may include a controller 370 configured to control the pressing force of a first pressing cylinder 353 and a second pressing cylinder 363 based on the thickness of the electrode mixture layer measured by a first thickness measuring sensor 381 and a second thickness measuring sensor 382. Therefore, the values ​​measured by the first and second thickness measuring sensors can be calculated in real time, allowing adjustment of the pressing force of the pressing cylinders without worker intervention.

[0075] For example, the first thickness measuring sensor 381 and the second thickness measuring sensor 382 can be as follows: Figure 3 The electrode shown is positioned above the electrode entering the cutter 390, or as... Figure 4 The arrangement shown is between the cutter 390, which cuts the electrode sheet into unit electrodes, and the pressing roller.

[0076] In another specific example, a first thickness measuring sensor 381 and a second thickness measuring sensor 382 may be disposed on the upper and lower surfaces of the second electrode 320. Therefore, the thickness of the electrode mixture layer 322 applied to the upper surface of the second electrode 320 at opposite ends in the y-axis direction can be measured, and the thickness of the electrode mixture layer 322 applied to the lower surface of the second electrode 320 at opposite ends in the y-axis direction can also be measured.

[0077] In other words, the thickness deviation between the electrode mixture layers applied to the upper and lower surfaces of the second electrode 320 can be measured, thereby enabling precise measurement of the gap between the first electrode 310 and the second electrode 320, as well as the gap between the third electrode 330 and the second electrode 320. The pressing force of the first pressing cylinder 353 and the second pressing cylinder 363 of the laminating device disposed on the lower surface of the second electrode 320 can be controlled independently of the pressing force of the first pressing cylinder 353 and the second pressing cylinder 363 of the laminating device disposed on the upper surface of the second electrode 320.

[0078] Therefore, the pressing force applied to the first and second ends of the upper pressing roller provided on the upper surface of the second electrode 320 can be set independently of the pressing force applied to the first and second ends of the lower pressing roller provided on the lower surface of the second electrode 320.

[0079] exist Figure 4 In the middle, the first electrode 310, the second electrode 320 and the third electrode 330 are stacked between the pressing rollers 351 with diaphragms (not shown) inserted between each electrode.

[0080] exist Figure 4 In this case, the electrode adjacent to the first pressing cylinder 353 has a relatively small thickness, so the pressing force of the first pressing cylinder 353 is greater than that of the second pressing cylinder 363. Therefore, the first pressing cylinder 353 and the second pressing cylinder 363 press the pressing roller 351 into close contact with the outermost electrode of the dual battery, and the pressing roller 351 adjacent to the rotation axis 352 connected to the first pressing cylinder 353 moves in a direction parallel to the z-axis and is pressed more strongly into contact with the dual battery.

[0081] Therefore, non-adhesion will not occur between the first, second, and third electrodes when a diaphragm is inserted between them.

[0082] In one specific example, the pressing roller 351 can be configured to be heated, so that the pressing roller can press the dual cells in a heated state. Therefore, the adhesion between the electrodes can be further increased.

[0083] Figure 5 This is a side view showing the state of laminating a dual-cell battery using a lamination apparatus according to another embodiment. Figure 6 It is shown toFigure 5 Add a perspective view of the controller status to the laminating equipment.

[0084] Reference Figure 5 and Figure 6 The structure includes the first electrode 310, the second electrode 320, the third electrode 330, and the separator 340 constituting the dual battery; the pressing roller 351; the rotating shaft 352; the first pressing cylinder 353, and the second pressing cylinder 363, and is similar in construction to... Figure 3 and Figure 4 The construction shown is the same, therefore refer to Figure 3 and Figure 4 The given description applies here as well.

[0085] Figure 5 and Figure 6 The thickness measurement sensor shown may include a first thickness measurement sensor 383 and a second thickness measurement sensor 384 respectively disposed at opposite ends of the second electrode 320 in the y-axis direction, thereby measuring the thickness of the electrode mixture layer 322 at positions corresponding to the opposite ends of the second electrode.

[0086] The first thickness measuring sensor 383 and the second thickness measuring sensor 384 each include irradiation portions 383a and 384a that irradiate beta rays capable of passing through the second electrode 320, and receiving portions 383b and 384b configured to sense the beta rays irradiated by the irradiation portions 383a and 384a. The irradiation portions 383a and 384a are disposed on the upper surface of the second electrode 320, and the receiving portions 383b and 384b are disposed on the lower surface of the second electrode.

[0087] Alternatively, the irradiation unit and the receiving unit can be positioned opposite to those shown in the figure.

[0088] The greater the thickness of the second electrode, the smaller the amount of β-rays remaining to reach the receiving part. Therefore, the total thickness of the electrode mixture layer applied to the upper and lower surfaces of the second electrode 320 can be measured using the first thickness measuring sensor 383 and the second thickness measuring sensor 384.

[0089] Alternatively, laser sensors can be placed above and below the second electrode, and the reflection time of the irradiated laser can be measured, thereby allowing the thickness of the second electrode to be measured.

[0090] When a dual cell configured to have a first electrode, a separator, a second electrode, a separator, and a third electrode stacked sequentially is manufactured using the lamination apparatus according to the invention as described above, adhesion can be achieved throughout the entire periphery between the first electrode and the second electrode, and between the second electrode and the third electrode.

[0091] The invention will be described below with reference to experimental examples. These experimental examples are provided only to facilitate a better understanding of the invention and should not be construed as limiting the scope of the invention.

[0092] <Experimental Example>

[0093] To examine the effect of the pressure applied when laminating a dual cell on the adhesion between the electrodes and the separator, a dual cell was manufactured.

[0094] Figure 7 These are vertical cross-sectional and plan views of the dual-cell battery manufactured based on the experimental example.

[0095] Reference Figure 7 The dual-cell configuration consists of a first electrode 310, an upper separator 441, a second electrode 320, a lower separator 442, and a third electrode 330 stacked sequentially, wherein the first electrode 310 and the third electrode 330 are positive electrodes, and the second electrode 320 is a negative electrode.

[0096] On the dual-cell battery thus manufactured, a first test was performed by setting the pressing force of the pressing roller used for lamination to 190 kgf and performing lamination at 90°C, and a second test was performed by setting the pressing force of the pressing roller to 170 kgf and performing lamination at 90°C.

[0097] As shown in the plan view of the dual-cell battery, the dual-cell battery is divided into three regions.

[0098] Specifically, the dual-cell structure is divided into: a tab portion, which is adjacent to the electrode tabs; a bottom portion, opposite to the tab portion; and an intermediate portion M located between the tab portion and the bottom portion. In each region, the adhesion forces between the second electrode 320 and the upper separator 441 (A), between the second electrode 320 and the lower separator 442 (B), between the first electrode 310 and the upper separator 441 (C), and between the third electrode 330 and the lower separator 442 (C) are measured.

[0099] To measure the adhesion force at (A), the second electrode 320 is fixed to a horizontal plate, the first electrode 310 and the upper diaphragm 441 are fixed to a gripping jig, and the first electrode and the upper diaphragm are pulled vertically to peel off from the second electrode, thereby measuring the adhesion force.

[0100] To measure the adhesion force at (B), the second electrode 320 is fixed to a horizontal plate, the third electrode 330 and the lower diaphragm 442 are fixed to a gripper, and the third electrode and the lower diaphragm are pulled vertically to peel off from the second electrode, thereby measuring the adhesion force.

[0101] To measure the adhesion force at (C), the first electrode 310 is fixed to a horizontal plate, the upper diaphragm 441 is fixed to a gripper, and the first electrode is pulled vertically to peel off the upper diaphragm, thereby measuring the adhesion force.

[0102] To measure the adhesion force at (D), the third electrode 330 is fixed to a horizontal plate, the lower diaphragm 442 is fixed to a gripper, and the third electrode is pulled vertically to peel off the lower diaphragm, thereby measuring the adhesion force.

[0103] In each of the first and second tests, as an adhesion force measurement experiment, the adhesion force at points (A) to (D) was measured twice for each of the butt panel portion, the lower portion, and the middle portion. The results and average values ​​are shown in the table below. The unit of adhesion force shown in the table below is gf / 20mm.

[0104] An Amtek Universal Testing Machine (UTM) was used as the adhesion force measurement device.

[0105] Referring to the table below, it can be seen that the adhesion force measured at higher pressure is higher than that measured at lower pressure.

[0106] Therefore, when the pressing force of the pressing roller is increased during lamination, it is expected that the adhesion between the electrode and the diaphragm can be increased. Thus, even if a gap is formed between the diaphragm and the electrode, the adhesion between the diaphragm and the electrode can be increased by increasing the pressing force of the pressing roller.

[0107]

[0108]

[0109] Those skilled in the art will understand that, based on the above description, various applications and modifications are possible within the scope of this invention.

[0110] (Refer to the labeling explanation)

[0111] 110, 210, 310: First electrode

[0112] 120, 220, 320: Second electrode

[0113] 121, 221, 311, 321, 331: Electrode current collectors

[0114] 122, 222, 312, 322, 332: Electrode mixture layer

[0115] 130, 230, 330: Third electrode

[0116] 140, 240, 340, 441, 442: Diaphragm

[0117] 150, 251, 351: Press rollers

[0118] 252, 352: Rotation axis

[0119] 253, 353: First pressing cylinder

[0120] 263, 363: Second pressing cylinder

[0121] 370: Controller

[0122] 381, 383: First thickness measurement sensor

[0123] 382, 384: Second thickness measurement sensor

[0124] 383a, 384a: Irradiation section

[0125] 383b, 384b: Receiving Unit

[0126] 390: Cutter

[0127] 441: Upper diaphragm

[0128] 442: Lower diaphragm.

Claims

1. A laminating apparatus for manufacturing electrode assemblies, the laminating apparatus comprising: A pressing roller configured to press the electrodes constituting the electrode assembly; The rotating shaft is configured to rotate the pressing roller; A pressing cylinder configured to adjust the pressing force applied to the pressing roller; and A thickness measurement sensor configured to measure the thickness of the electrode mixture layer of the electrodes. The pressing cylinder includes a first pressing cylinder and a second pressing cylinder respectively connected to opposite ends of the rotating shaft. The pressing force applied by the first pressing cylinder and the pressing force applied by the second pressing cylinder are different from each other. The electrode assembly is a dual-cell battery configured to have a structure in which a first electrode, a separator, a second electrode, a separator, and a third electrode are stacked. The thickness measurement sensor measures the thickness deviation between the electrode mixture layers applied to the upper and lower surfaces of the second electrode, thereby measuring the gap between the first and second electrodes, and the gap between the third and second electrodes. The thickness measuring sensor includes a first thickness measuring sensor and a second thickness measuring sensor respectively disposed at opposite ends of the electrode. When a difference arises between the thickness of the electrode mixture layer of the electrode measured by the first thickness sensor and the thickness of the electrode mixture layer of the electrode measured by the second thickness sensor, the pressing roller presses the electrode more forcefully at the location where the electrode thickness is smaller. This causes the portions of the first and third electrodes adjacent to the smaller thickness portion of the electrode mixture layer of the second electrode to be pressed more forcefully in the direction toward the second electrode. The laminating apparatus further includes a controller configured to control the pressing force of the pressing cylinder when a difference arises between the thickness of the electrode mixture layer of the electrode as measured by the first thickness measuring sensor and the thickness of the electrode mixture layer of the electrode as measured by the second thickness measuring sensor.

2. The laminating apparatus according to claim 1, further comprising: First electrode supply unit; Second electrode supply unit; and Third electrode supply unit, The thickness measuring sensor measures the thickness of the electrode mixture layer of the second electrode supplied from the second electrode supply unit.

3. The laminating apparatus according to claim 1, wherein: Each of the electrodes is a double-sided electrode formed by coating an electrode mixture on two opposing surfaces of the electrode current collector. The laminating device is disposed on each of the upper and lower surfaces of the electrode assembly.

4. The laminating apparatus according to claim 3, wherein: The thickness measurement sensor includes: an irradiation unit configured to irradiate beta rays capable of passing through the electrodes; and a receiving unit configured to sense the beta rays irradiated by the irradiation unit. The irradiation part is disposed on either the upper or lower surface of the electrode, while the receiving part is disposed on the other surface.

5. The laminating apparatus according to claim 3, wherein the pressing force applied to the first and second ends of the upper pressing roller disposed on the upper surface of the electrode is set independently of the pressing force applied to the first and second ends of the lower pressing roller disposed on the lower surface of the electrode.

6. The laminating apparatus of claim 1, wherein the pressing roller is configured to be heated.

7. An electrode assembly manufactured using the lamination apparatus according to any one of claims 1 to 6, wherein: The first electrode and the second electrode are bonded to each other throughout the periphery, and the second electrode and the third electrode are bonded to each other throughout the periphery.

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