Apparatus and method for manufacturing electrode assembly

Abstract

The present invention relates to an electrode assembly manufacturing apparatus including a stack table, a gripper, and a first press unit. The stack includes a first electrode, a second electrode, and a section of a separator between the first and second electrodes. The stack table is configured to support the stack. The gripper is configured to fix the stack. The first press unit is configured to heat and compress the stack fixed by the gripper.

Description

[Technical field]

[0001] This application claims the benefit of the filing date of Korean Patent Application No. 10-2021-0090592 filed with the Korean Intellectual Property Office on July 9, 2021, Korean Patent Application No. 10-2021-0090588 filed with the Korean Intellectual Property Office on July 9, 2021, and Korean Patent Application No. 10-2021-0090589 filed with the Korean Intellectual Property Office on July 9, 2021, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to an apparatus and method for manufacturing an electrode assembly, and more particularly, to an apparatus and method for manufacturing an electrode assembly, in which a stack of an anode, a separator, and a cathode is fixed using a gripper, and then pressure is applied to the stack to prevent the electrodes from being distorted when pressure is applied. [Background technology]

[0003] Unlike primary batteries, secondary batteries are rechargeable and 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 growing rapidly.

[0004] Secondary batteries are classified into coin-type batteries, cylindrical batteries, square batteries, and pouch-type batteries according to the shape of the battery case. The electrode assembly attached inside the battery case of a secondary battery is a power generating element capable of charging and discharging, which is made of a laminated structure of electrodes and a separator.

[0005] The electrode assembly can be alternatively classified into a jelly-roll type in which a sheet-type anode and cathode coated with an active material are wound with a separator interposed between them; a stack type in which a number of anodes and cathodes are stacked in sequence with a separator interposed between them; and a stack-and-fold type in which a stack-type unit cell is wound with a long separator film.

[0006] In a conventional process for manufacturing a stack-and-fold type electrode assembly, a laminate in which electrodes and a separator are stacked is heated and pressurized to bond the electrodes and the separator to manufacture the electrode assembly. However, it is known that when the laminate is compressed in the conventional process for manufacturing the electrode assembly, the electrodes are distorted.

[0007] In order to solve these problems of the conventional electrode assembly, the electrodes and the separator are heated and laminated, and then the layers are laminated and pressurized to bond them together, and the separator envelops the outermost edge of the laminate of the electrodes and the separator, thereby manufacturing an electrode assembly.

[0008] However, this advantage is reduced for later stacked electrodes: the adhesion of the first stacked electrode increases through multiple pressing steps, but the adhesion of the last stacked electrode is relatively low because it only goes through one pressing step, with the last stacked electrode having the weakest adhesion.

[0009] That is, the adhesive strength decreases in the stacking direction, so it is necessary to provide a more uniform adhesive strength throughout the stack of the electrode assembly. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention provides an electrode assembly manufacturing apparatus and a manufacturing method thereof, which pressurize and fix upper and lower surfaces of a stack in which electrodes and a separator are stacked, and then heat and press the stack.

[0011] The present invention provides an apparatus and method for manufacturing an electrode assembly, which can ensure uniformity of adhesive strength of the electrode assembly through two pressure processes. [Means for solving the problem]

[0012] One embodiment of the present invention provides an electrode assembly manufacturing apparatus for manufacturing a laminate including a first electrode, a second electrode, and a second electrode portion of a separator between the first electrode and the second electrode, the electrode assembly manufacturing apparatus including: a stack table for supporting the laminate; a gripper for fixing the laminate; and a first press portion for heating and compressing the laminate fixed by the gripper.

[0013] In one embodiment of the present invention, in fixing the laminate, the gripper may hold the laminate in any one or any combination of the same position relative to the first press part, the same orientation relative to the first press part, and the same configuration. In one embodiment of the present invention, in maintaining the laminate in the same configuration, one or more layers of the laminate, such as adjacent first and second electrodes, may be maintained in a position opposite each other. In one embodiment and another embodiment, in maintaining the laminate in the same configuration, one or more surfaces of the laminate pressed by the gripper, such as the top and bottom ends of the laminate, may be maintained in a position opposite each other.

[0014] In one embodiment of the present invention, there is provided an apparatus for manufacturing an electrode assembly, wherein the first press section includes a pair of pressure blocks configured to compress opposing surfaces of the laminate, the pair of pressure blocks being movable toward each other to compress either one or both of the laminate and the gripper.

[0015] In one embodiment of the present invention, there is provided an apparatus for manufacturing an electrode assembly, wherein the gripper is provided in the form of a pillar or plate extending in a direction parallel to one or both of an upper surface defined by an upper surface of the laminate and a lower surface defined by a lower surface of the laminate, the gripper presses a portion of one or both of the upper surface and the lower surface of the fixing part to fix the laminate, and at least one of a pair of pressure blocks of the first press part includes a gripper groove having a shape corresponding to the shape of the gripper.

[0016] One embodiment of the present invention provides an electrode assembly manufacturing apparatus, further comprising a second press section that heats and presses the laminate, wherein a pair of pressure blocks of the second press section provide flat pressure surfaces that contact the laminate and press the laminate.

[0017] One embodiment of the present invention provides an electrode assembly manufacturing apparatus, further comprising a second press section for heating and pressing the laminate, the gripper being provided in the form of a column or plate extending in a direction parallel to one or both of an upper surface defined by an upper surface of the laminate and a lower surface defined by a lower surface of the laminate, the gripper fixing a portion of one or both of the upper surface and the lower surface of the laminate, each of a pair of press blocks of the first press section having a flat press surface that contacts the laminate and presses the laminate, and at least one or more of the pair of press blocks of the second press section including at least one or more second press block grooves configured to be placed on corresponding compressed portions of the laminate.

[0018] In one embodiment of the present invention, there is provided an apparatus for manufacturing an electrode assembly, wherein the gripper is provided in the form of a pillar or plate extending in a direction parallel to one or both of an upper surface defined by an upper surface of the laminate and a lower surface defined by a lower surface of the laminate, the gripper presses a portion of one or both of the upper surface and the lower surface of the laminate to fix the laminate, and at least one of a pair of pressure blocks of the first press section presses the gripper so that the gripper presses the laminate.

[0019] In one embodiment of the present invention, there is provided an apparatus for manufacturing an electrode assembly, wherein the first press section includes a press heater that heats a pair of press blocks.

[0020] In one embodiment of the present invention, there is provided an apparatus for manufacturing an electrode assembly, wherein the length and width of the pressing surfaces of the pair of pressing blocks are greater than the length and width of the laminate.

[0021] One embodiment of the present invention provides an apparatus for manufacturing an electrode assembly, comprising: a separation membrane supplying unit that supplies the separation membrane to the stack table; a first electrode supplying unit that stacks the first electrode on a first electrode portion of the separation membrane supported on the stack table includes a first electrode mounting table that mounts the first electrode before the first electrode is stacked on the separation membrane; and a first transfer head that temporarily fixes the first electrode and transfers the first electrode from the first electrode mounting table to the first electrode portion on the separation membrane supported on the stack table while the first electrode is temporarily fixed; and when the second electrode portion is supported on the stack table, a second electrode supplying unit that stacks the second electrode on the second electrode portion of the separation membrane includes a second electrode mounting table on which the second electrode is mounted before the second electrode is stacked on the separation membrane, and a second transfer head that temporarily fixes the second electrode and transfers the second electrode from the second electrode mounting table to the second electrode portion of the separation membrane supported on the stack table while the second electrode is temporarily fixed.

[0022] In one embodiment of the invention, the first and second transfer heads may each include a vacuum device for temporarily fixing the first and second electrodes.

[0023] One embodiment of the present invention provides an apparatus for manufacturing an electrode assembly, further comprising a rotating unit that rotates the stack table, wherein the first electrode supply unit is provided on one side of the rotating unit and the second electrode supply unit is provided on the other side opposite to the one side of the rotating unit, and the stack table is rotated to the second side so as to face the second transfer head when the second electrode is stacked.

[0024] In one embodiment of the present invention, there is provided an apparatus for manufacturing an electrode assembly, wherein the rotation unit rotates the stack table alternately toward the first electrode supply unit and toward the second electrode supply unit.

[0025] In one embodiment of the present invention, there is provided an apparatus for manufacturing an electrode assembly, wherein the first press section presses the laminate for a time period ranging from 5 seconds to 20 seconds in an environment in which the ambient temperature is in the range of 45°C to 75°C and a pressure in the range of 1 MPa to 2.5 MPa is applied.

[0026] In one embodiment of the present invention, there is provided an apparatus for manufacturing an electrode assembly, wherein a second press section that heats and pressurizes the laminate is pressurized by the first press section for 5 to 60 seconds in an environment having an ambient temperature of 50°C to 90°C and applying a pressure of 1 MPa to 6 MPa.

[0027] Another embodiment of the present invention provides a method for manufacturing an electrode assembly, comprising: providing and stacking a first electrode, a separator, and a second electrode, and disposing the separator between the first electrode and the second electrode to provide a laminate of the first electrode and the second electrode; heating and pressing the stack in a first press while clamping the laminate with a gripper; and heating and pressing the laminate using a second press after heating and pressing the laminate in the first press.

[0028] In another embodiment of the present invention, there is provided a method for manufacturing an electrode assembly, wherein the step of heating and pressing the laminate using the second press unit heats and presses the laminate after the gripper is removed.

[0029] In another embodiment of the invention, the second press section may be the first press section with the grippers removed.

[0030] In another embodiment of the present invention, there is provided a method for manufacturing an electrode assembly, wherein in the step of heating and pressing the laminate in the first press section, a surface of the laminate where the gripper is not located is pressed.

[0031] In another embodiment of the present invention, there is provided a method for manufacturing an electrode assembly, wherein the step of heating and pressing the laminate in the first press section presses a surface of the laminate provided with the gripper on the surface of the laminate.

[0032] In another embodiment of the present invention, there is provided a method for manufacturing an electrode assembly, wherein the step of heating and pressing the laminate in a first press section is performed for a time period of 5 to 20 seconds in an environment having an ambient temperature of 45°C to 75°C and applying a pressure of 1 MPa to 2.5 MPa.

[0033] In another embodiment of the present invention, there is provided a method for manufacturing an electrode assembly, wherein the step of heating and pressing the laminate in the second press section is performed for 5 to 60 seconds in an environment where the ambient temperature is 50°C to 90°C and a pressure in the range of 1 MPa to 6 MPa is applied.

[0034] Another embodiment of the present invention provides an electrode assembly manufacturing apparatus for manufacturing a laminate including a first electrode, a second electrode, a first electrode portion of a separation membrane based on the first electrode, and a second electrode portion of a separation membrane between the first electrode and the second electrode, the electrode assembly manufacturing apparatus including: a stack table configured to support the laminate; a separation membrane supplying device configured to supply the separation membrane to the stack table; a first electrode supplying unit configured to stack the first electrode on the first electrode portion of the separation membrane supported by the stack table; a second electrode supplying unit configured to stack the second electrode on the second electrode portion of the separation membrane supported by the stack table; a gripper configured to fix the laminate; a first press unit configured to heat and pressurize the laminate fixed by the gripper, and a second press unit configured to heat and pressurize the laminate. Effect of the Invention

[0035] According to the electrode assembly manufacturing apparatus and the electrode assembly manufacturing method, the laminate in the manufactured electrode assembly may include a plurality of first electrodes and a plurality of second electrodes. In one embodiment, the plurality of first electrodes and the plurality of second electrodes may be alternately arranged between the stacked portions of the separator.

[0036] According to the electrode assembly manufacturing apparatus and the electrode assembly manufacturing method of the present invention, after the electrodes and the separator are stacked, the stack is fixed, and then heating and pressurization are performed to compress the electrode assembly, thereby preventing or at least suppressing deformation of the electrodes of the electrode assembly.

[0037] In addition, after removing the member fixing the laminate, the laminate is heated and pressurized, so that adhesion can be provided to areas where adhesion is not ensured because they are not heated or pressed by the member fixing the laminate, and uniform adhesion of the electrode assembly can be ensured. [Brief description of the drawings]

[0038] [Figure 1] 1 is a cross-sectional view showing an electrode assembly according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view showing a stack of the electrode assembly of FIG. 1. [Diagram 3] 1 is a plan view showing an apparatus for manufacturing an electrode assembly according to an embodiment of the present invention; [Figure 4] FIG. 2 is a front view showing a manufacturing apparatus for the electrode assembly of FIG. [Figure 5(a)] FIG. 11 is a perspective view showing a first press section and a gripper according to still another embodiment. [Figure 5(b)] FIG. 11 is a perspective view showing a second pressing section according to still another embodiment. [Figure 5(c)] FIG. 11 is a perspective view showing a second pressing section according to still another embodiment. [Figure 6] FIG. 11 is a perspective view showing a first press section and a gripper according to still another embodiment. [Figure 7] 11 is a flowchart of a method for manufacturing an electrode assembly according to still another embodiment. [Explanation of symbols]

[0039] S ···Laminate 1...1st electrode 1a First electrode tab 2...Second electrode 2a Second electrode tab 4...1st separation membrane 4a...Laminated part 4b Folding section 5...Second separation membrane 100 Manufacturing apparatus for electrode assembly 10. Stack Table 20...Separation membrane supply section 21 Separation membrane roll 30...First electrode supply section 31 First electrode mounting table 32 First transfer head 33 First electrode roll 34 No. 1 cutter 35 First conveyor 36 First electrode supply head 37 First moving part 40...Second electrode supply section 41 Second electrode mounting table 42 Second transfer head 43 Second electrode roll 44 No. 2 cutter 45 Second conveyor 46 Second electrode supply head 47 Second moving part 50, 150 ···First Press Section 50a, 50b, 150a, 150b...First pressure block 51 Gripper 51a Main unit 51b...Fixed part 52 Gripper groove 60, 160 ···Second Press Section 60a, 60b, 160a, 160b...Second pressure block 162 Second pressure block groove DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] The detailed description of the present invention is intended to fully explain the present invention to those having ordinary skill in the art. Throughout this specification, when a part is described as "including" a certain component, or when a certain structure and shape are described as "characterized", this means that other components, structures, and shapes may be included, without excluding other components or excluding other structures and shapes, unless otherwise specified to the contrary.

[0041] Since the present invention can be modified in various ways and can have various embodiments, a specific embodiment will be presented and described in detail in the detailed description. However, this is not intended to limit the content of the invention by the embodiment, and it should be understood that the present invention includes all modifications, equivalents, or alternatives included in the spirit and technical scope of the present invention.

[0042] Hereinafter, the present invention will be described in detail with reference to the drawings. However, the drawings are for illustrating the present invention, and the scope of the present invention is not limited by the drawings.

[0043] 1 and 2, the electrode assembly may include a laminate S and a second separator 5 surrounding the laminate S.

[0044] As shown, in the laminate S, the first electrodes 1 and the second electrodes 2 may be alternately arranged between the laminated portions 4a of the first separator 4. Furthermore, as shown, the first separator 4 may be folded in a zigzag shape to form the laminated portions 4a.

[0045] 3 to 5, an electrode assembly manufacturing apparatus 100 includes a stack table 10, a separation membrane supply unit 20, a first electrode supply unit 30, a second electrode supply unit 40, and a second press unit 60. The stack table 10 may have one support surface on which the first electrode 1, the stack of the first separator 4 and the second electrode 2 are stacked in this order. The stack S includes the first combination, the first electrode 1, the second electrode 2 stacked on the first combination, and an additional portion of the first separator 4 arranged between the first and second electrodes. The first separator 4 may be folded in a zigzag manner to form a folded portion 4b on the opposing side of the stack 4a of the first separator 4 and each stack 4a of the separator. The folded portion 4b includes a folded portion of the stack S. In this manner, each stack 4a of the first separator 4 is arranged between each of the first electrodes 1 and the second electrodes 2 in the stack S in which each first electrode 1 is alternately arranged with each of the second electrodes 2.

[0046] The stack table 10 can rotate in one direction toward each of the first electrodes 1 provided so that the first electrodes 1 are stacked on the stacked portions 4a of the first separator 4 supported by the stack table 10 and the previously stacked electrode and separator stacked portions 4a, and can rotate in the other direction opposite to the one direction toward each of the second electrodes 2 provided so that the second electrodes 2 are stacked on the stacked portions 4a of the first separator 4 supported by the stack table 10 and the previously stacked electrode and separator stacked portions 4a. Therefore, the electrode assembly manufacturing apparatus 100 may further include a rotating unit (not shown) that rotates the stack table 10. For details regarding such a rotating unit, please refer to Korean Patent Publication No. 10-2020-0023853, which is incorporated herein by reference.

[0047] In the electrode assembly manufacturing apparatus 100, the first electrode supply unit 30 may be located on one side of the stack table 10, and the second electrode supply unit 40 may be located on the other side of the stack table 10. In the configuration of the electrode assembly manufacturing apparatus 100 shown in the figure, the rotation unit may alternately rotate the stack table 10 in the direction of the first electrode supply unit 30 and the direction of the second electrode supply unit 40.

[0048] For example, the separation membrane supply unit 20 may be located above the stack table 10, i.e., along the stacking direction of the stack S. In this configuration, the first electrode supply unit 30 may be located on the left side of the stack table 10, and the second electrode supply unit 40 may be located on the right side of the stack table 10 based on the stacking direction of the stack S.

[0049] In the configuration of the electrode assembly manufacturing apparatus 100 shown in the figures, the rotating unit may rotate the stack table 10 so that, when stacking the first electrode 1, the stack table 10 faces the first transfer head 32 or another first mounting device for temporarily holding the first electrode 1. When stacking the second electrode 2, the rotating unit may rotate the stack table 10 so that the stack table 10 faces a second mounting device or a second transfer head 42 for temporarily holding the second electrode 2.

[0050] In using the electrode assembly manufacturing apparatus 100, the stacking portion 4a and the folding portion 4b of the first separator 4 may be supplied by the separator supplying portion 20 and placed on the stack table 10 as a partial arrangement. When the rotating portion rotates the stack table 10 to the left, the first electrode 1 supplied from the first electrode supplying portion 30 may be supplied onto the first separator 4. The rotating portion may also rotate the stack table 10 to the right, and such rotation may occur at the same time as the first separator 4 is supplied. In such a rotating configuration of the rotating portion, the first separator 4 may form a first pocket in the form of a left pocket covering the lower surface, right side surface and upper surface of the first electrode 1 of the laminate S. Here, the first electrode 1 of the laminate S may be placed on the stack table 10 such that the upper surface of the first electrode 1 is covered by a portion of the first separator 4. In this case, the second electrode 2 may be supplied from the second electrode supplying portion 40 to the portion of the first separator 4 covering the upper surface of the first electrode 1.

[0051] By repeating the above process, the first separator 4 may be placed on the stack table 10 from the separator supply unit 20 in the form of a left pocket and a right pocket at a position opposite the left pocket. In this configuration, when each portion of the first separator 4 is arranged to be located on the stack table 10, the left and right pockets alternately form left and right openings, respectively, and the left and right openings may be configured to accommodate the first electrode 1 and the second electrode 2 supplied by the first electrode supply unit 30 and the second electrode supply unit 40, respectively. Also, when the first separator 4 is folded, the folding portion 4b of the first separator 4, which may be in the form of a folded portion, may be provided at a position facing the left and right openings (see FIG. 2). A mirror arrangement may be used with respect to the arrangement of the electrode assembly manufacturing apparatus 100. In some alternative arrangements, the first separator 4 may form a first pocket in the form of a right pocket covering the lower surface, left surface, and upper surface of the second electrode 2. In one embodiment, the second electrode 2 may be the first electrode of a stack S placed on the stack table 10 .

[0052] The stack table 10 may further include a table body (not shown) that determines the shape of the stack table 10, and a table heater (not shown), and the table heater may be, for example, a resistance coil mounted above, below, or inside the body of the stack table 10. The table heater may heat the table body to heat the laminate S attached to the stack table 10.

[0053] The table heater can heat the laminate S before the laminate S is heated and compressed by the first press unit 50 of the electrode assembly manufacturing apparatus 100. Preheating the laminate S by such a table heater can shorten the time it takes for heat to be conducted to the center of the laminate S, and can reduce the pressurization time required for sufficient pressurization by the first press unit 50.

[0054] In addition, when the laminate S preheated by the table heater is pressed and fixed by the gripper 51 of the first press section 50 described further in this specification, the portion pressed by the gripper 51 may be primarily bonded, and a second bond may be formed by the pressure applied by the first press section 50.

[0055] 3 and 4, as in the example of the electrode assembly manufacturing apparatus 100, the separation membrane supplying unit 20 may be configured to supply the first separation membrane 4 to the stack table 10. For details of such a separation membrane supplying unit, refer to Korean Patent Publication No. 10-2020-0023853. For example, as shown in FIG. 4, the separation membrane supplying unit 20 may be located above the stack table 10. In addition, the separation membrane supplying unit 20 may include a separation membrane roll 21 around which the first separation membrane 4 is wound. The first separation membrane 4 wound around the separation membrane roll 21 may be gradually unwound by gravity and supplied to the stack table 10.

[0056] The separation membrane supply unit 20 has a passage through which the first separation membrane 4 passes. The separation membrane supply unit 20 may include a separation membrane heating unit (not shown) for heating the passing first separation membrane 4. For details of the separation membrane heating unit, refer to Korean Patent Publication No. 10-2020-0023853.

[0057] The separation membrane heating unit may include a pair of bodies (not shown) and a separation membrane heater (not shown) for heating the bodies. The pair of bodies may be located on both sides of the first separation membrane 4 with a predetermined distance between them so that the first separation membrane 4 can pass through. For example, the first separation membrane 4 may pass through the separation membrane heating unit in a non-contact manner so that the first separation membrane 4 is heated in a non-contact manner. In one embodiment, the pair of bodies of the separation membrane heating unit may be formed in the shape of, for example, a rectangular block.

[0058] As illustrated in the electrode assembly manufacturing apparatus 100, the first electrode supply unit 30 may be configured to supply the first electrode 1 to the stack table 10 and stack the first electrode 1 on the stack table 10. The first electrode supply unit 30 may include a first electrode attachment table 31 on which the first electrode 1 is attached before being stacked on the stack table 10.

[0059] The first electrode supply unit 30 may also include a first electrode roll 33, a first cutter 34, a first conveyor 35, and a first electrode supply head 36. The first electrode supply unit 30 winds the first electrode sheet on which the first electrode 1 is formed around the first electrode roll 33 and gradually unwinds it while supplying any one of the first electrodes 1 to the first electrode attachment table 31. The first cutter 34 can cut the first electrode 1 from the first electrode sheet supplied from the first electrode roll 33 to a previously set length. The first cutter 34 may cut the first electrode sheet so that the first electrode tab 1a protrudes from the end of the first electrode 1.

[0060] The first electrode 1 cut by the first cutter 34 may be fed to a first conveyor 35, which may be in the form of a belt as shown, and may move the first electrode 1 to a first electrode mounting table 31. A first electrode feed head 36 (e.g., via a vacuum fitting, suction cup, or similar fitting, or other form of temporary attachment such as magnetic attachment, etc.) may pick up the first electrode 1 placed on the first conveyor 35 and position it on the first electrode mounting table 31.

[0061] As shown, the first electrode supply section 30 may include a first transfer head 32 and a first mover section 37 along which the first transfer head 32 can extend and oscillate.

[0062] The first transfer head 32 (e.g., via a vacuum fitting, suction cup, or similar fitting, or other temporary form of attachment such as magnetic attachment) can pick up the first electrode 1 attached to the first electrode attachment table 31. In one embodiment, the first transfer head 32 can include a vacuum suction unit (not shown) on a bottom surface of the transfer head that can be configured to suck the first electrode 1 through the vacuum inlet to attach the first electrode 1 to the bottom surface of the first transfer head 32. A channel formed in the first transfer head 32 can couple the vacuum inlet to the vacuum suction device (not shown).

[0063] The first mover 37 may be configured to pick up the first electrode 1 mounted on the first electrode mounting table 31 and move the first transfer head 32 to a position where it can be released, e.g., by reducing or removing the vacuum suction or other force applied to the first electrode 1 to hold the first electrode 1 against the transfer head, so that it is placed on the stack table 10. In this manner, the first transfer head 32 may transfer the first electrode 1 from the first electrode mounting table 31, via the other electrodes 1, 2, to a section of the first separation membrane 4 that is to be placed on or to be placed on the stack table 10.

[0064] The second electrode supply unit 40 may have, or may essentially have, a mirror configuration of the first electrode supply unit 30. In this manner, the second electrode supply unit 40 may supply the second electrode 2 to a portion of the stack S attached to the stack table 10, and stack the second electrode 2 onto such portion of the stack S on the stack table 10.

[0065] The second electrode supply unit 40 may include a second electrode attachment table 41 on which the second electrode 2 is attached before being moved to a portion of the stack S on the stack table 10 and stacked.

[0066] The second electrode supply unit 40 may include a second electrode roll 43 on which the second electrode sheet on which the second electrode 2 is formed is wound up, a second cutter 44 that cuts the second electrode sheet at regular intervals while unwinding the second electrode sheet from the second electrode roll 43 to form second electrodes 2 of a certain size, a second conveyor 45 that moves the second electrodes 2 cut by the second cutter 44, and a second electrode supply head 46 that picks up the second electrodes 2 moved by the second conveyor 45 and attaches them to the second electrode attachment table 41.

[0067] Similar to the first cutter 34 , the second cutter 44 may cut the second electrode sheet so that the formed second electrode 2 includes a second electrode tab 2 a protruding from an end of the second electrode 2 .

[0068] The second electrode supply unit 40 may also include a second transfer head 42 that picks up the second electrode 2 attached to the second electrode attachment table 41, and a second moving unit 47 configured to move to an upper portion of the stack table 10 where the second transfer head 42 is released, for example, by reducing or removing the vacuum suction or other force applied to the second electrode 2 to hold the second electrode 2 against the second transfer head 42. At this time, the second transfer head 42 may stack the second electrode 2 on a portion of the stack S on the stack table 10. The second transfer head 42 may be formed in the same manner as the first transfer head 32, such that the second electrode 2 is temporarily attached to the second transfer head 42 at the bottom surface of the second transfer head 42.

[0069] The laminate S may be moved to the press section by a gripper 51 that grips the laminate on the stack table 10 and then moves the laminate to the press section where the heat pressing operation is performed. The press section may be divided into a first press section 50 and a second press section 60.

[0070] Referring to FIG. 5(a) and FIG. 5(b), the first press unit 50 may first heat and press the laminate S in a fixed state. The first press unit 50 includes a pair of first press blocks 50a, 50b, and may further include a gripper 51 for fixing the laminate S so that the electrodes in the laminate are not disturbed when the press unit presses the laminate. When fixing the laminate S, the gripper 51 may maintain the relative positions of the first electrode 1, the second electrode 2, and the laminated portion 4a of the first separator 4 located between the first electrode and the second electrode. As shown in the example, in order to maintain such relative positions, the gripper 51 may press the upper and lower surfaces of the laminate S. In one embodiment, when fixing the laminate S, the gripper 51 may maintain the laminate in the same position relative to the first press unit 50, particularly in any one or any combination of the same orientation and the same configuration relative to the pair of first press blocks 50a, 50b. In one embodiment, in maintaining the stack S in the same configuration, one or more layers of the stack may be maintained in relative positions, such as the first and second electrodes 1, 2. In one embodiment and in another embodiment, in maintaining the stack in the same configuration, one or more of the surfaces of the stack pressed by the grippers, such as the top and bottom surfaces, i.e., the top and bottom surfaces of the stack S, may be maintained in relative positions with respect to each other.

[0071] The pair of first pressure blocks 50a, 50b of the first press section 50 may move toward or away from each other. The pair of first pressure blocks 50a, 50b may compress either or both of the laminate S and the gripper 51 as they move toward each other.

[0072] In this way, the first press section 50 can heat and pressurize the laminate S to reduce or eliminate the space between the first electrode 1 and the laminate portion 4a of the first separation membrane 4, and between the second electrode 2 and the laminate portion 4a.

[0073] As shown, the pressure surface of each of the pair of first pressure blocks 50a, 50b configured for contacting and applying pressure to the laminate S may be provided as a flat surface. At least one of the pair of first pressure blocks 50a, 50b may include a gripper groove 52 having a shape corresponding to the fixing portion 51b of the gripper 51 described below. In the example shown in FIG. 5(a), each of the pair of first pressure blocks 50a, 50b includes four gripper grooves 52 corresponding to the four fixing portions 51b. However, the number of gripper grooves may be more or less. Preferably, the number of gripper grooves should match the number of fixing parts used.

[0074] The gripper 51 may include a main body 51a and a plurality of fixing portions 51b. As shown, the main body 51a may have a length x and a height y (such height being measured in the stacking direction of the laminate S) that are the same or approximately the same as the length and height of the laminate S. In one embodiment, the main body may have a height that is longer than the length x of the laminate S and greater than the height y of the laminate S. The fixing portions 51b extend from the side of the main body 51a. The fixing portions 51b may preferably be in the form of a rod, a column, or a plate that extends toward the laminate S when the gripper 51 is in a suitable position in the first press section 50. In this suitable position, the fixing portions 51b have a width z in a direction toward the laminate S. Here, the length x of the laminate S may refer to the portion where the distance from one end to the other end of the laminate S is the longest, and the height y may refer to the distance in the direction in which the laminate S is stacked. Width z may refer to the distance measured in a direction perpendicular to the direction in which the length x and height y distances are measured, for example the distance measured across the top surface of the stack S away from the gripper 51.

[0075] The fixing portions 51b may be provided in two rows, one row aligned with the gripper groove 52 of the first pressurizing block 50a and the other row aligned with the gripper groove 52 of the first pressurizing block 50b. The position of each of the fixing portions 51b may be adjusted in the height direction of the main body 51a. In this manner, each of the fixing portions 51b may be in contact with the upper and lower surfaces of the stack S, preferably disposed along its width, and may fix the position of the stack S and the relative positions of the first electrode 1 and the second electrode 2 within the stack S.

[0076] In one embodiment, when in operation, the first press section 50 may compress the laminate S for 5 to 20 seconds, for example using a pair of first pressure blocks 50a, 50b, in an environment with an ambient temperature of 45°C to 75°C and a pressure of 1 MPa to 2.5 MPa.

[0077] In one embodiment, the second press section 60 may perform a second compression on the laminate S that has already been primarily compressed by applying heat and pressure to the laminate S that has been preheated and compressed by the first press section 50 .

[0078] As shown in Fig. 5(b), the second press section 60 includes a pair of second pressurizing blocks 60a, 60b. The pair of second pressurizing blocks 60a, 60b may be moved toward or away from each other. The pair of second pressurizing blocks 60a, 60b can compress the laminate by applying pressure to the upper and lower surfaces of the laminate S while moving toward each other.

[0079] As shown, the pressing surface of each of the pair of second press blocks 60a, 60b configured for contacting and compressing the laminate S may be provided as a flat surface. As in the illustrated example, in one embodiment, grooves such as the groove for the fixing portion 51b may be omitted from the second press blocks 60a, 60b. In other embodiments, at least one of the pair of second press blocks 60a, 60b may include a groove. Referring to FIG. 5(c), in one embodiment, such a groove may be generally in the form of a second press block groove 162 of the second press section 160. However, unlike the second press block groove 162, the groove of the pair of second press blocks of the second press section (not shown) used after the first press section 50 and gripper 51 may extend along the surface or face of the laminate S compressed by one or both of the first press blocks 50a, 50b. In this manner, such a groove of the second press block defines a protruding portion of the press block that provides a pressing surface for pressing the laminate S.

[0080] In one embodiment, during operation, the second press section 60 may compress the laminate previously compressed by the first press section 50 for a period of 5 to 60 seconds in an environment having an ambient temperature in the range of 50°C to 90°C and applying a pressure in the range of 1 MPa to 6 MPa. In one embodiment, the second press section 60 may heat and press only a portion of the laminate S where the gripper 51 is located, for example, a position where the laminate S is not heated and pressed by the first press section 50. In another embodiment, the second press section 50 may heat and press all areas of the upper and lower surfaces of the laminate S.

[0081] In one embodiment, each of the pair of first pressure blocks 50a, 50b of the first press section 50 includes a gripper groove having a shape corresponding to the fixed portion 51b of the gripper 51, and each of the pair of second pressure blocks 60a, 60b of the second press section 60 has a flat pressure surface without a gripper groove.

[0082] In one embodiment, the first press unit 50 may clamp the top and bottom surfaces of the laminate S with grippers 51 while initially compressing the heated laminate S. In this manner, in areas or regions of the stack where the grippers 51 are not located, the space between the first electrodes 1 and adjacent laminate portions 4a of the first separator 4 may be reduced or eliminated during bonding of such first electrodes 1 and their adjacent laminate portions, and the space between the second electrodes 2 and their adjacent laminate portions may be reduced or eliminated during bonding of such second electrodes 2 and their adjacent laminate portions.

[0083] In one embodiment, the second press unit 60 may compress and further heat the preheated laminate S previously bonded by the first press unit 50 and from which the gripper 51 has been removed. Thus, the second press unit 60 may reduce or eliminate the space between the first electrode 1 and the adjacent laminates 4a of the first separator 4 and the space between the second electrode 2 and the adjacent laminates in the regions of the upper and lower surfaces of the laminate S pressed by the gripper 51 during the primary pressing by the first press unit 50 during bonding. In one embodiment, each of the pair of second pressing blocks 60a, 60b may be a rectangular block in the shape of a rectangular parallelepiped. In one embodiment, the pair of second pressing blocks 60a, 60b may have a flat pressing surface as previously described herein.

[0084] 6, in one embodiment, the first press section 150 may have the same configuration as the first press section 50, except that the pair of first press blocks 150a, 150b of the first press section 150 may exclude the gripper groove 52. Instead, each of the pair of first press blocks 150a, 150b of the first press section 50 may have a flat press surface, like the pair of second press blocks 60a, 60b. In this manner, when the pair of first press blocks 150a, 150b move toward each other, the flat press surfaces of the first press blocks may press the fixed portion 51b of the gripper 51 and the gripper 51 to press the upper and lower surfaces of the stack S. In one embodiment, as shown in FIG. 5(c), each of the pair of second pressure blocks 160a, 160b of the second press unit 160 may have a second pressure block groove 162 located at a position where the gripper 51 presses the upper and lower surfaces of the laminate S when the first press unit 150 applies pressure. In this manner, the groove areas of the pair of second pressure blocks 160a, 160b do not come into contact with each other when the second press unit 160 applies pressure, so that the laminate S is not pressed. As further shown in FIG. 5(c), the second pressure block groove 162 may have a shape corresponding to the fixing portion 51b of the gripper 51.

[0085] In one embodiment, the fixing portion 51b may include a heat conductive material, preferably a metal material, and more preferably a material including aluminum or an aluminum alloy, iron or an iron alloy, or a combination of aluminum and iron. By transferring heat to the laminate S, when the first press unit 50 compresses the laminate S fixed by the gripper 51, adjacent laminate portions 4a of the electrodes 1 and 2 and the first separator 4 may be joined while reducing or eliminating the space between them.

[0086] In one embodiment, the second press unit 60 may not compress areas of the laminate S where the grippers 51 were previously located, but instead may only compress areas of the laminate S where the grippers were not previously located and areas not compressed by the first press unit 50. Such compression by the second press unit 60 may reduce or eliminate the space between the electrodes 1, 2 and adjacent laminate portions 4a of the first separator 4, thereby bonding each electrode to the separator.

[0087] Further, each of the pair of first pressurizing blocks 50a, 50b may be a rectangular block having a rectangular parallelepiped shape. In one embodiment, the pair of first pressurizing blocks 50a, 50b may have a flat pressurizing surface as previously described herein.

[0088] Either one or both of the first and second press units 50, 60 may include a press heater (not shown) and may be configured to heat a portion of the laminate S of the first and second electrodes 1 and the first separator 4 when each pair of the first and second press blocks 50a, 50b, 60a, 60b presses the laminate. In this manner, when the laminate S is pressed by the first and second press units 50, 60, the thermal fusion between the first electrode 1, the first separator 4 and the second electrode 2 is more firmly performed, and stronger adhesion can be formed between these layers.

[0089] In any of the pair of first and second pressure blocks 50a, 50b, 60a, 60b, the length and width of each pressure surface may be greater than the corresponding length x and width z of the laminate S in which the first electrode 1, the first separation membrane 4, and the second electrode 2 are stacked.

[0090] As shown in FIG. 1 and FIG. 2, the laminate S may be configured such that the first separator 4 surrounds the outermost surface of the laminate. In this manner, the inner surface of the first separator 4 surrounding the laminate S may be bonded to the outer surface of the folded portion 4b of the first separator 4 facing the corresponding outer surfaces of the first and second electrodes 1, 2 and the inner surface of the separator, and the laminated portion and folded portion 4a, 4b of the first and second electrodes 1, 2 and the first separator 4 may be joined by heating and pressing the first and second press units 50, 60. Here, the outermost surface of the laminate S surrounded by the first separator 4 may include the upper surface, the lower surface and two opposing side surfaces of the laminate. The two side surfaces of the laminate S in a plane parallel to the stacking direction do not include the electrode tabs 1a, 2b. The upper and lower surfaces of the laminate S may be perpendicular to these side surfaces.

[0091] Therefore, when the first electrode 1, the first separator 4, and the second electrode 2 are stacked to form an electrode assembly, the use of the gripper 51 can more effectively prevent the first electrode 1, the second electrode 2, and the first separator 4 from becoming dislodged from the stacked configuration when pressure is applied by the press units 50 and 60.

[0092] In one embodiment, the electrode assembly manufacturing apparatus 100 may further include a third moving part (not shown) attached to the third moving head (not shown) and configured to rotate or move in another manner. The third moving part and the third moving head may be the same as or similar to the first and second moving parts 37, 47 and the first and second moving heads 32, 42, respectively. In this manner, the third moving part and the third moving head may move the laminate S to the second pressing part 60 after the primary pressing by the first pressing part 50. In one embodiment, the third moving head may be a suction head that allows the third moving head to temporarily hold the laminate S via vacuum suction.

[0093] In one embodiment, the first press section 50 compresses the laminate S while heating the laminate. In this manner, the laminate S can achieve the minimum adhesion necessary to withstand transfer of the laminate through the third transfer head by vacuum suction while maintaining the laminate's morphology.

[0094] In some embodiments, the third moving section may include a connecting section (not shown) connecting the rotating shaft and the third transfer head. In such a configuration, when the third transfer head initially sucks in the laminate S bonded by the first press section 50, the rotating shaft of the third moving section can rotate to move the laminate from the first press section 50 to the second press section 60.

[0095] Referring to FIG. 6, the electrode assembly manufacturing process may include a laminate manufacturing step (S10) for manufacturing a laminate such as laminate S, a first heat press step (S20) for initial heating and pressing of the laminate, and a second heat press step (S30) for secondary heating and pressing, e.g., subsequent heating and pressing of the initially pressed laminate.

[0096] The step of producing a laminate (S10) may be performed by supplying and stacking a first electrode (e.g., first electrode 1), a separator (e.g., first separator 4) and a second electrode (e.g., second electrode 2) to the laminate during a stacking process on a stack table (e.g., stack table 10). The laminate being processed in this step is supported by the stack table.

[0097] In step S11 of producing a stack, a section of the separator may be fed to the stack table. In one embodiment, a section of the separator may be stacked on the stack table. In step S12, the stack table is rotated toward a first electrode feeder, e.g., first electrode feeder 30. In step S13, the first electrode is fed and then attached to the stack table or stacked on top of an otherwise attached separator section. In step S14, the stack table is rotated toward a second electrode feeder, e.g., second electrode feeder 40, and folded so that an additional section of the separator is placed on the first electrode. In step S15, a second electrode is fed and then stacked on top of another section of the separator. In step S16, steps S12, S13, S14, and S15 are repeated to sequentially add one or more additional first electrodes, separator sections, and one or more additional second electrodes. In repeating step S12, another portion of the separator is folded and stacked onto the second electrode via rotation of the stack table, and a next first electrode is provided and stacked onto the additional portion of the separator. By alternate rotation of the stack table, the separator may be stacked between the first and second electrodes in a zigzag pattern.

[0098] Also, in step S17 of the step (S10) of preparing the laminate, the outermost portion of the laminate may be surrounded by the separator by rotating the separator in one direction. Here, the outermost portion of the laminate includes the upper surface, the lower surface, and both opposing side surfaces of the laminate. Each side surface may extend in a plane parallel to the stacking direction of the laminate. Each of the side surfaces may exclude all surfaces on which the electrode tabs, for example the first electrode tab 1a, are located. The upper surface and the lower surface of the laminate each include a surface perpendicular to one or both of the side surfaces of the laminate.

[0099] The first heat pressing step (S20) is a step for providing adhesive force to the entire laminate. In this step, one or both of the upper and lower surfaces of the laminate may be pressed and fixed using a gripper, for example, gripper 51. At the same time, the upper and lower surfaces of the laminate may be pressed toward each other in a heated first press section, for example, first press section 50, by a pair of press blocks, such as press blocks 50a and 50b.

[0100] At this time, the first press unit may be used to pressurize the upper or lower surface of the laminate with a gripper positioned on a portion of the upper or lower surface of the laminate.

[0101] In one embodiment, in the first heat pressing step (S20), the first electrode, the separator, and the second electrode on the surface where the gripper is located may not be bonded. That is, in the first heat pressing step S20, the first electrode, the separator, and the second electrode may be bonded by pressing only the surface of the laminate where the gripper is not located. In one embodiment, the first press part may include a groove having a shape corresponding to the shape of the gripper so as not to press the gripper.

[0102] In one embodiment, in the first heat pressing step (S20), the surface of the laminate where the gripper is located is pressed to bond the first electrode, the separator, and the second electrode. In one embodiment, the first press unit may be provided with a flat surface for pressing the laminate, and the gripper may include a thermally conductive material. In this way, the gripper can press the laminate by receiving heat from the heated first press unit, and adhesive force can be imparted only to the first electrode, the separator, and the second electrode in the portion of the laminate where the gripper is located.

[0103] The first heat pressing step (S20) may be performed in an environment in which the ambient temperature of the laminate is in the range of 45°C to 75°C and a pressure in the range of 1 MPa to 2.5 MPa is applied, while the laminate is fixed by a gripper for a period of 5 seconds to 20 seconds.

[0104] The second heat pressing step (S30) may provide a secondary adhesive force to the laminate after the initial adhesive force has been provided in the first heat pressing step (S20). The second heat pressing step (S30) may provide such adhesive force to a part or parts of the laminate that were not provided with adhesive force in the first heat pressing step (S20).

[0105] The second heat pressing step (S30) may be performed after the first heat pressing step (S20), in which case the laminate may be pressed with the grippers removed from the laminate. In the second heat pressing step (S30), the laminate may be pressed using a heated second press unit, for example, second press unit 60.

[0106] In one embodiment, in the second heat pressing step (S30), the second press section may have a flat surface for pressing the entire surface of the laminate opposite to the surface of the laminate to be pressed.

[0107] In one embodiment, in the second heat pressing step (S30), the second press may include holes or grooves having a shape corresponding to the shape of the grippers so as to press only the portions of the laminate where the grippers are not located. In this manner, adhesive force may be applied to the entire stack, and indeed may be applied uniformly throughout the stack.

[0108] In one embodiment, in the second heat pressing step (S30), the grippers are removed and the initially heated and pressed laminate may be pressed for a time in the range of 5 seconds to 60 seconds in an environment having an ambient temperature of 50°C to 90°C and an ambient pressure of 1 MPa to 6 MPa.

[0109] In one embodiment, the ambient temperature for the second heat pressing step (S30) may be 50° C. or higher, preferably 65° C. or higher.

[0110] In one embodiment, the ambient temperature for the second heat pressing step (S30) may be 90°C or less, preferably 85°C or less.

[0111] In one embodiment, the ambient temperature for the second heat pressing step (S30) may be 50° C. to 90° C., preferably 65° C. to 90° C., more preferably 65° C. to 85° C. Most preferably, the ambient temperature for the second heat pressing step may be 70° C.

[0112] In one embodiment, the pressure applied in the second heat pressing step (S30) may be 1 MPa or more, preferably 1.5 MPa or more, and more preferably 3 MPa or more.

[0113] In one embodiment, the pressure applied in the second heat pressing step (S30) may be 6 MPa or less, preferably 5.5 MPa or less.

[0114] In one embodiment, the pressure applied in the second heat pressing step (S30) may be from 1 MPa to 6 MPa, preferably from 1.5 MPa to 6 MPa, and more preferably from 3 MPa to 5.5 MPa.

[0115] In one embodiment, the heating and pressing in the second heat pressing step (S30) may be for a period of 5 seconds or more, preferably 7 seconds or more.

[0116] In one embodiment, the heating and pressing in the second heat pressing step (S30) may be for 60 seconds or less, preferably 30 seconds or less, and more preferably 25 seconds or less.

[0117] In one embodiment, the heating and pressing in the second heat pressing step (S30) may be for a period ranging from 5 seconds to 60 seconds, preferably from 5 seconds to 30 seconds, and more preferably from 7 seconds to 25 seconds.

[0118] In one embodiment, the second heat pressing step (S30) may be heated and pressed in an environment having an ambient temperature in the range of 50°C to 90°C and a pressure of 1 MPa to 6 MPa applied for 5 seconds to 60 seconds, preferably in an environment having an ambient temperature in the range of 6°C to 90°C and a pressure of 1.5 MPa to 6 MPa applied for 5 seconds to 30 seconds. More preferably, the second heat pressing step may be heated and pressed in an environment having an ambient temperature of 65°C to 85°C and a pressure of 3 MPa to 5.5 MPa applied for 7 seconds to 25 seconds. Here, the environment for the second heat pressing step (S30) is most preferably an ambient temperature of 70°C.

[0119] Here, the pressure for initial heating and pressurization and the pressure for secondary heating and pressurization refer to the pressure applied by a pair of pressure blocks, and the ambient temperature refers to the temperature of heat applied by the body of the stack table or the pair of pressurization blocks. Furthermore, the pair of pressurization blocks may be the same or different. That is, the stack may be heated and pressurized by the pair of pressurization blocks while the stack is held by the grippers, and then heated and pressurized by the same pair of pressurization blocks while the grip by the grippers is loosened.

[0120] If the temperature, pressure, and time conditions are not met, the electrodes of the electrode assembly may not be firmly bonded and the assembly may become overly porous.

[0121] That is, when the conditions of temperature, pressure, and time are met, the electrodes constituting the electrode assembly may be simultaneously given appropriate adhesive strength without being individually heated or pressurized to manufacture the electrode assembly, while ensuring air permeability between the separator and the electrodes constituting the electrode assembly and minimizing damage to the unit electrodes.

[0122] In one embodiment, the positive electrode can be prepared, for example, by coating a positive electrode current collector with a positive electrode coating mixture that includes a positive electrode active material, a conductive material, and a binder, and then drying the coating mixture. If necessary, a filler may be added to the mixture. Such materials may be any suitable material used in the relevant field, particularly a material commonly used for a particular application field.

[0123] Specifically, the positive electrode active material is, for example, a layered compound such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), or a compound substituted with one or more transition metals; 1+x Mn 2-x Lithium manganese oxides such as LiMnO4 (where x is 0 to 0.33), LiMnO3, LiMn2O3, and LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, LiFe3O4, V2O5, and Cu2V2O7; and the chemical formula LiNi 1-x M x Lithium nickel oxide with Ni site represented by the chemical formula LiMnO2 (where M=Co, Mn, Al, Cu, Fe, Mg, B or Ga, and x=0.01 to 0.3); 2-x M x Examples of such compounds include, but are not limited to, lithium manganese composite oxides represented by Li2Mn3MO8 (where M is Co, Ni, Fe, Cr, Zn, or Ta, and x is 0.01 to 0.1) or Li2Mn3MO8 (where M is Fe, Co, Ni, Cu, or Zn); LiMn2O4 in which part of the Li in the chemical formula is replaced with an alkaline earth metal ion; disulfide compounds; and Fe2(MoO4)3.

[0124] Materials that can be used for the anode current collector are not particularly limited. The anode current collector preferably has a relatively high electrical conductivity without causing chemical changes when used in a battery. For example, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc. may be used. The anode current collector may be preferably aluminum. Preferably, the surface of the collector in contact with the coating mixture may include fine irregularities to increase the adhesive strength between the collector and the anode coating mixture. In addition, various forms such as a film, sheet, foil, net, porous body, foam, nonwoven fabric body, etc. are possible. The anode current collector may generally have a thickness of 3 μm to 500 μm.

[0125] The conductive material contained in the anode coating mixture may generally be contained in an amount of 1 to 50% by weight of the total weight of the mixture including the anode active material. For example, graphite such as natural graphite or artificial graphite; carbon black such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, summer black; conductive fiber such as carbon fiber or metal fiber; metal powder such as carbon fluoride, aluminum, nickel powder; conductive whiskey such as zinc oxide or potassium titanate; conductive metal oxide such as titanium oxide; conductive material such as polyphenylene derivatives may be used.

[0126] The binder of the anode coating mixture is a component that aids in bonding between the active material and the conductive material and in binding the coating mixture to the current collector. Such binders may generally be included in an amount of 1-50% by weight of the total weight of the mixture including the anode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butylene rubber, fluororubber, various copolymers, and the like.

[0127] The filler, which is optionally added to the anode coating mixture, may be used as a component to suppress the expansion of the anode. Such a filler is not particularly limited, and may include a fibrous material that does not cause a chemical change when used in a battery. For example, olefin polymers such as polyethylene and polypropylene; glass fiber, carbon fiber, and other fibrous materials may be used.

[0128] In one embodiment, the negative electrode may be prepared by applying a negative electrode active material onto a negative electrode current collector, drying, and pressing the negative electrode active material. If necessary, the negative electrode active material may further include a conductive material, a binder, a filler, and the like as described above. In this case, a material commonly used in the art may be used. Specifically, the negative electrode active material may be, for example, carbon such as non-graphitizable carbon or graphite-based carbon; Li x Fe2O3(0≦x≦1), Li x WO2(0≦x≦1), Sn x Me 1-x Me' y O zMetal composite oxides such as (Me: Mn, Fe, Pb, Ge; Me': Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, halogen; 0 < x ≦ 1; 1 ≦ y ≦ 3; 1 ≦ z ≦ 8), etc.; lithium metal; lithium alloy; silicon-based alloy; tin-based alloy; metal oxides such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, and Bi2O5; conductive polymers such as polyacetylene; Li-Co-Ni-based materials, etc. may be used.

[0129] The material that can be used for the cathode current collector is not particularly limited. The cathode current collector preferably does not cause a chemical change when used in a battery and has a relatively high conductivity. For example, copper, stainless steel, aluminum, nickel, titanium, fired carbon, those with a surface treatment of carbon, nickel, titanium, silver, etc. on the surface of copper or stainless steel, aluminum-cadmium alloy, etc. can be used. Also, similar to the anode current collector, fine irregularities can be formed on the surface to strengthen the binding force of the cathode active material. It may be used in various forms such as films, sheets, foils, nets, porous bodies, foams, non-woven bodies, etc. Furthermore, the cathode current collector may generally have a thickness of 3 μm to 500 μm.

[0130] In one embodiment of the present invention, the separation membrane may be an organic / inorganic composite porous SRS (Safety-Reinforcing Separators) separation membrane. The SRS separation membrane may have a structure in which a coating layer component containing inorganic particles and a binder polymer is applied on a polyolefin-based separation membrane substrate.

[0131] Such an SRS separation membrane does not cause high-temperature thermal shrinkage due to the heat resistance of the inorganic particles. Therefore, even if the electrode assembly penetrates through by a needle-shaped conductor, the elongation rate of the safety separation membrane can be maintained.

[0132] The SRS separator may have a uniform pore structure formed by the interstitial volume between inorganic particles, which are a component of the coating layer, as well as the pore structure contained in the separator substrate itself. The pores can not only significantly reduce external impacts on the electrode assembly, but also allow smooth movement of lithium ions through the pores, and a large amount of electrolyte can be filled to show a high impregnation rate, thereby improving the performance of the battery.

[0133] In one embodiment of the present invention, the separator may be sized according to the width dimension (perpendicular to the longitudinal dimension in which the separator is expanded) of the separator so that the separator extends outward from both sides beyond the edges corresponding to the adjacent anode and cathode (hereinafter, "excess portion"). In addition, the separator may be configured to have a structure in which a coating layer thicker than the thickness of the separator is formed on one or both sides of the excess portion of the separator to prevent the separator from shrinking. For details regarding the thick coating layer of the excess portion extending outward from the separator, refer to Korean Patent Publication No. 10-2016-0054219, the entire contents of which are incorporated herein by reference. In one embodiment of the present invention, the excess portion of the separator may be 5% to 12% in size based on the width of the separator. In another embodiment of the present invention, the coating layer may be coated on both sides of the separator with a size of 50% to 90% in size based on the width of the excess portion of the separator on one side. In addition, the widths of the coating layers on both sides may be the same or different sizes.

[0134] In one embodiment of the present invention, the coating layer may contain inorganic particles and a binder polymer.

[0135] In one embodiment of the present invention, examples of the polyolefin-based separation membrane component include high density polyethylene, linear low density polyethylene, low density polyethylene, ultra-high molecular weight polyethylene, polypropylene, or derivatives thereof.

[0136] In one embodiment of the present invention, the thickness of the coating layer may be smaller than the thickness of the first electrode or the second electrode. In a specific example, the thickness of the coating layer may be 30% to 99% of the thickness of the first electrode or the second electrode.

[0137] In one embodiment of the present invention, the coating layer may be formed by wet coating or dry coating.

[0138] In one embodiment of the present invention, the substrate and the coating layer are present in a form of anchoring in which the pores on the surface of the polyolefin-based separator substrate and the coating layer are intertwined, and the separator substrate and the active layer can be physically strongly bonded. The thickness ratio of the substrate and the active layer of the separator may be 9:1 to 1:9. Preferably, the thickness ratio may be 5:5.

[0139] In one embodiment of the present invention, the inorganic particles may be inorganic particles commonly used in the art. The inorganic particles interact with each other to form micropores in the form of empty spaces between the inorganic particles, and at the same time, can help structurally maintain the physical form of the coating layer. In addition, the inorganic particles generally have physical properties that do not change even at high temperatures of 200°C or higher, so that the organic / inorganic composite porous film formed has excellent heat resistance.

[0140] In addition, the material that can be used for the inorganic particles is not particularly limited, but is preferably an electrochemically stable material. That is, the inorganic particles that can be used in the present invention are not particularly limited as long as they do not undergo oxidation and / or reduction reactions in the operating voltage range of the applied battery (for example, 0 to 5 V based on Li / Li+). In particular, when inorganic particles with ion transfer ability are used, the ion conductivity in the electrochemical element can be increased to improve performance. Therefore, it is preferable to use inorganic particles with as high an ion conductivity as possible. In addition, when the inorganic particles have a high density, it is difficult to disperse the inorganic particles during coating, which increases the weight of the battery during battery manufacture. Therefore, it is preferable to use inorganic particles with as low a density as possible. In addition, in the case of an inorganic material with a high dielectric constant, it contributes to an increase in the degree of dissociation of the electrolyte salt, for example, lithium salt, in the liquid electrolyte, and can improve the ion conductivity of the electrolyte.

[0141] For the above reasons, the inorganic particles may be at least one type selected from the group consisting of inorganic particles having piezoelectricity and inorganic particles having lithium ion transport ability.

[0142] The piezoelectric inorganic particles are non-conductors at normal pressure, but when a certain pressure is applied, they are materials that have the property of conducting electricity due to changes in their internal structure. They are also materials that exhibit high dielectric constant characteristics with a dielectric constant of 100 or more. The piezoelectric inorganic particles are also materials (e.g., separators) that have the function of generating electric charges when stretched or compressed by applying a certain pressure, with one side being positively charged and the other side being negatively charged, thereby generating a potential difference between both sides.

[0143] When inorganic particles having the above characteristics are used as a coating layer component, if an internal short circuit occurs between the electrodes due to an external impact such as a needle-shaped conductor, the inorganic particles coated on the separator may prevent the anode and cathode from coming into direct contact with each other. In addition, the piezoelectricity of the inorganic particles generates a potential difference within the particles, which causes electron transfer (i.e., a minute current flow) between the electrodes, resulting in a gradual decrease in the battery voltage and thus improved safety.

[0144] Examples of the inorganic particles having piezoelectricity include BaTiO3, Pb(Zr,Ti)O3 (PZT), Pb 1-x La x Zr 1-y Ti y O3(PLZT), PB(Mg3Nb 2 / 3 )O3-PbTiO3 (PMN-PT) and hafnia (HfO2), but is not limited thereto.

[0145] The inorganic particles having lithium ion transport ability refer to inorganic particles that contain lithium elements but do not store lithium but instead transport lithium ions. The inorganic particles having lithium ion transport ability can transport lithium ions through a type of defect present inside the particle structure. As a result, the lithium ion conductivity in the battery is improved, and thus the battery performance can be improved.

[0146] Examples of inorganic particles having the lithium ion transfer ability include lithium phosphate (Li3PO4), lithium titanium phosphate (Li x Ti y (PO4)3, 0 <x<2、0<y<3)、リチウムアルミニウムチタニウムホスフェート(Li x Al y Ti z (PO4)3, 0 <x<2、0<y<1、0<z<3)、(LiAlTiP) x O yIt is glass (0 < x < 4, 0 < y < 13), lithium lanthanum titanate (LixLayTiO3, 0 < x < 2, 0 < y < 3), lithium germanium thiophosphate (Li x Ge y P z S w , 0 < x < 4, 0 < y < 1, 0 < z < 1, 0 < w < 5), lithium nitride (Li x N y , 0 < x < 4, 0 < y < 2), SiS2 (Li x Si y S z , 0 < x < 3, 0 < y < 2, 0 < z < 4) - based glass and P2S5 (Li x P y S z , 0 < x < 3, 0 < y < 3, 0 < z < 7) - based glass, and may be one or more selected from the group consisting of, but not limited to, these.

[0147] The composition ratio of the inorganic particles and the binder polymer constituting the coating layer of the separation membrane is not particularly limited, but can be adjusted within the range of 10:90 to 99:1% by weight, and a range of 80:20 to 99:1% by weight is preferred. When the composition ratio is less than 10:90% by weight, the content of the polymer becomes excessively large, and the pore size and porosity due to the decrease in the empty space formed between the inorganic particles decrease, which may cause a decrease in the performance of the final battery. On the other hand, when it exceeds 99:1% by weight, since the polymer content is too small, the adhesive force between the inorganics weakens, and the mechanical properties of the final organic / inorganic composite porous separation membrane may decrease.

[0148] In one embodiment of the present invention, as the binder polymer, a binder polymer generally used in the art may be used.

[0149] Among the above organic / inorganic composite porous separation membranes, the coating layer may further contain other commonly known additives in addition to the aforementioned inorganic particles and binder polymer.

[0150] In one embodiment of the present invention, the coating layer can also be said to be an active layer.

[0151] Although the present invention has been described in detail with reference to exemplary configurations, the electrode assembly manufacturing apparatus according to the present invention is not limited to these configurations. Various embodiments may be implemented by those skilled in the art within the scope of the technical concept of the present invention.

[0152] In addition, the description of the manufacturing apparatus for an electrode assembly according to the present invention and the configuration of the apparatus are applicable to the manufacturing method for an electrode assembly according to the present invention and the electrode assembly manufactured by the manufacturing method. The electrode assembly can be manufactured by the manufacturing apparatus for an electrode assembly according to the present invention.

[0153] While the present invention has been described above with reference to preferred embodiments, it will be understood that those skilled in the art can make various modifications and variations of the present invention without departing from the spirit and scope of the present invention as set forth in the following claims.

[0154] Working Example 1) Example 1 Nineteen anodes, 20 cathodes and a separation membrane were supplied to the stack table from the anode supply unit, cathode supply unit and separation membrane supply unit, respectively.

[0155] More specifically, the anode and cathode were supplied in the form of an anode sheet and a cathode sheet cut into pieces, respectively, and the separator was supplied in the form of a separator sheet. Then, the supplied separator was folded while rotating the stack table, and the anode, cathode, and separator were stacked. At this time, stacking was performed while pressing and fixing the upper surface of the anode or cathode stacked on the top of the stack table with a gripper, so that the anodes and cathodes were alternately arranged between the folded separators, and a stack using 39 electrodes was manufactured.

[0156] After the laminate was produced, it was gripped with a gripper and pressed for 15 seconds while being heated in an environment of an ambient temperature of 70° C. and a pressure of 1.91 MPa (first heat press step).

[0157] After the first heat pressing step, a second heat pressing step was performed in which the stack table was heated to a temperature (temperature condition) of 70° C. and the laminate was pressed with a pressure block of the press at a pressure (pressure condition) of 2.71 MPa for 10 seconds (pressing time) as shown in Table 1 below, thereby manufacturing the electrode assembly of Example 1.

[0158] The above-described content of the present invention may be applied in the process of manufacturing the electrode assembly.

[0159] 2) Examples 2 to 12 The electrode assemblies of Examples 2 to 12 were manufactured in the same manner as in Example 1, except that the second heat pressing was performed under the temperature conditions, pressure conditions, and pressing time shown in the following Table 1. That is, the first heat pressing conditions of Examples 1 to 12 were the same.

[0160] [Table 1]

[0161] 3) Comparative Examples 1 to 5 The electrode assemblies of Comparative Examples 1 to 5 were manufactured in the same manner as in Example 1, except that the first heat pressing step was performed under the temperature conditions, pressure conditions, and pressing times shown in Table 2 below, and the second heat pressing step was not performed.

[0162] [Table 2]

[0163] The electrode assemblies of Examples 1 to 12 and Comparative Examples 1 to 5 prepared under the conditions of Tables 1 and 2 were subjected to vacuum suction for 60 seconds under the same conditions as the electrode supply unit of the present invention. As a result, it was observed that the electrodes and the separator were separated from all of the electrode assemblies of Comparative Examples 1 to 5 within 60 seconds.

[0164] This means that the electrode assemblies of Comparative Examples 1 to 5 have poor adhesion between the electrodes and the separator, whereas the electrode assemblies according to the present invention, which have undergone the first and second pressings, have good adhesion and have an excellent effect of preventing loosening of the folding of the electrode assembly.

[0165] In the case of Comparative Examples 6 and 7, separation of the electrode and the separator was not observed before 60 seconds, but it was confirmed that damage occurred to the electrode assembly when vacuum adsorption was performed under a pressure condition of 2.54 MPa.

[0166] 3) Experimental Example 1 - Adhesion strength evaluation and voltage resistance evaluation The electrode assemblies of Examples 1 to 12 and Comparative Examples 6 and 7, in which no separation between the electrode and the separator was observed before 60 seconds as a result of vacuum suction, were disassembled and analyzed to measure the adhesive strength of the upper, lower and middle surfaces. Specifically, the adhesive strength between the cathode located at the lowest end in the stacking direction of the electrode assembly and the separator (cathode adhesive strength) was measured and determined as the lower adhesive strength, and the adhesive strength between the cathode located at the highest end in the stacking direction of the electrode assembly and the separator (anode adhesive strength) was measured and determined as the upper adhesive strength. The adhesive strength between the cathode located at the midpoint between the upper and lower ends of the electrode assembly and the separator (cathode adhesive strength) was measured and determined as the middle adhesive strength.

[0167] More specifically, the upper end, the lower end, and the intermediate positions between the upper end and the lower end of the electrode assembly were separated along the stacking direction of the electrode assembly.

[0168] The cathode and the separator of each separated electrode assembly were sampled to have a width of 55 mm and a length of 20 mm.

[0169] The sample was attached to a glass slide so that the electrodes were located on the adhesive side of the glass slide.

[0170] Thereafter, the slide glass to which the sample was attached was placed on an adhesion tester, and the separator was pulled in a direction perpendicular to the plane on which the slide glass was placed, and the value at which the separator was peeled off from the electrode was measured.

[0171] The results are shown in Table 3 below.

[0172] [Table 3]

[0173] Referring to the results in Table 3, in the case of Comparative Examples 6 and 7, as described above, it was confirmed that the electrode assembly may be damaged when vacuum suction is performed under a pressure condition of 2.54 MPa, and the variation in adhesive strength is much larger than 15 gf / 20 mm, which means that the performance of the electrode assembly is not uniform depending on the position.

[0174] On the other hand, in the cases of Examples 1 to 12, it was confirmed that the variation in adhesive strength was less than 15 gf / 20 mm and was not significant, that is, it was confirmed that the electrode assemblies of Examples 1 to 12 had uniform performance.

[0175] 3) Experimental Example 2 - Breathability Evaluation Among Examples 1 to 12, the air permeability of the electrode assemblies of Examples 1, 6, and 12, which differ only in the temperature condition of the second press, was evaluated.

[0176] Specifically, the separation membranes were collected from the electrode assemblies of Examples 1, 6, and 12, and then cut into separation membrane samples measuring 5 cm x 5 cm (width x length). The separator samples were then washed with acetone.

[0177] Hereinafter, the air permeability of Examples 1, 6 and 12 was measured according to the JIS Gurley measurement method of the Japanese Industrial Standard, using a Toyoseiki Gurley type Densometer (No. 158) at room temperature and a pressure of 0.05 MPa, by measuring the time it took for 100 ml (or 100 cc) of air to pass through a 1 square inch separation membrane.

[0178] The results are shown in Table 4.

[0179] [Table 4]

[0180] From the results of Table 4, it was confirmed that when the second heat pressing conditions according to the present invention were met, the permeability corresponding to each position was less than 120 sec / 100 ml, which is a suitable level for use as an electrode assembly. In addition, it was confirmed that the deviation in permeability according to position was 20 sec / 100 ml or less, which is a level that can be determined to be uniform. In other words, it was again confirmed that the performance of the electrode assembly manufactured by the manufacturing method according to the present invention is uniform.

[0181] Among them, it was confirmed that the deviation in air permeability was the smallest in Example 1 where the temperature condition was 70° C. From the above experimental examples, it was confirmed that the electrode assembly according to the present invention has appropriate and uniform air permeability and adhesive strength.

Claims

1. 1. An apparatus for manufacturing an electrode assembly for manufacturing a laminate including a first electrode, a second electrode, and a second electrode portion of a separator between the first electrode and the second electrode, comprising: a stack table for supporting the stack; a gripper for fixing the laminate; a first press section for heating and compressing the laminate held by the grippers; and A second press section for heating and pressing the laminate. An apparatus for manufacturing an electrode assembly, comprising:

2. the first press section includes a pair of pressure blocks configured to compress opposing surfaces of the laminate; The electrode assembly manufacturing apparatus according to claim 1 , wherein the pair of pressure blocks are movable toward each other to compress either one or both of the laminate and the gripper.

3. The gripper is provided in the form of a post or plate extending in a direction parallel to one or both of an upper surface defined by an upper surface of the stack and a lower surface defined by a lower surface of the stack; the gripper applies pressure to a portion of one or both of an upper surface and a lower surface of the stack to secure the stack; The manufacturing apparatus for an electrode assembly according to claim 2 , wherein at least one of the pair of pressure blocks of the first press unit includes a gripper groove having a shape corresponding to a shape of the gripper.

4. An electrode assembly manufacturing apparatus as described in claim 3, wherein a pair of pressure blocks of the second press section have flat pressure surfaces that contact the laminate and pressurize the laminate.

5. The gripper is provided in the form of a pillar or plate extending in a direction parallel to one or both of an upper surface defined by an upper surface of the laminate and a lower surface defined by a lower surface of the laminate; the gripper clamps a portion of either one or both of an upper surface and a lower surface of the stack; Each of the pair of pressure blocks of the first press section has a flat pressure surface that contacts the laminate and presses the laminate, 3. The electrode assembly manufacturing apparatus of claim 2, wherein at least one of the pair of pressure blocks of the second press section includes at least one second pressure block groove configured to be placed on a corresponding compressed portion of the laminate.

6. The gripper is provided in the form of a post or plate extending in a direction parallel to one or both of an upper surface defined by an upper surface of the stack and a lower surface defined by a lower surface of the stack; the gripper applies pressure to a portion of one or both of an upper surface and a lower surface of the stack to secure the stack; The manufacturing apparatus for an electrode assembly according to claim 2 , wherein at least one of the pair of pressure blocks of the first press section presses the gripper so that the gripper presses the laminate.

7. 3. The electrode assembly manufacturing apparatus according to claim 2, wherein the first press section includes a press heater for heating a pair of pressurizing blocks.

8. 3. The electrode assembly manufacturing apparatus according to claim 2, wherein the length and width of the pressing surfaces of the pair of pressing blocks are greater than the length and width of the laminate.

9. a separation membrane supply unit that supplies the separation membrane to the stack table; a first electrode supplying unit that stacks the first electrode on the first electrode portion of the separation membrane supported on the stack table includes: a first electrode mounting table that mounts the first electrode before the first electrode is stacked on the separation membrane; and a first transfer head that temporarily fixes the first electrode and transfers the first electrode from the first electrode mounting table to the first electrode portion of the separation membrane supported on the stack table in a state in which the first electrode is temporarily fixed; 2. The electrode assembly manufacturing apparatus of claim 1, wherein when the second electrode portion is supported on the stack table, a second electrode supplying unit that stacks the second electrode on the second electrode portion of the separation membrane includes a second electrode mounting table on which the second electrode is mounted before the second electrode is stacked on the separation membrane, and a second transfer head that temporarily fixes the second electrode and transfers the second electrode from the second electrode mounting table to the second electrode portion of the separation membrane supported on the stack table while the second electrode is temporarily fixed.

10. Further comprising a rotating unit that rotates the stack table, the first electrode supply unit is provided on one side of the rotating unit, and the second electrode supply unit is provided on the other side opposite to the one side of the rotating unit, The electrode assembly manufacturing apparatus according to claim 9 , further comprising: rotating the stack table to a second side so as to face the second transfer head when the second electrode is stacked.

11. The apparatus for manufacturing an electrode assembly according to claim 10 , wherein the rotating unit alternately rotates the stack table toward the first electrode supply unit and toward the second electrode supply unit.

12. 2. The electrode assembly manufacturing apparatus of claim 1, wherein the first press unit presses the laminate for a time period ranging from 5 seconds to 20 seconds in an environment in which an ambient temperature is in the range of 45° C. to 75° C. and a pressure in the range of 1 MPa to 2.5 MPa is applied.

13. 2. The electrode assembly manufacturing apparatus of claim 1, wherein the second press section that heats and pressurizes the laminate presses the laminate for 5 to 60 seconds in an environment having an ambient temperature of 50° C. to 90° C. and applying a pressure of 1 MPa to 6 MPa.

14. providing and stacking a first electrode, a separator, and a second electrode, and disposing the separator between the first electrode and the second electrode to produce a stack of the first electrode and the second electrode; applying heat and pressure to the stack in a first press while clamping the stack with grippers; and After the step of heating and pressing the laminate in the first press section, the step of heating and pressing the laminate using a second press section. A method for manufacturing an electrode assembly comprising:

15. The method of claim 14 , wherein the step of applying heat and pressure to the laminate using the second press unit applies heat and pressure to the laminate after the gripper is removed.

16. The method of claim 14 , wherein in the step of heating and pressing the laminate in the first press unit, a surface of the laminate not positioned by the gripper is pressed.

17. The method of claim 14 , wherein in the step of heating and pressing the laminate in the first press section, the gripper presses a surface of the laminate provided on the surface of the laminate.

18. 15. The method of claim 14, wherein the step of heating and pressing the laminate in the first press section is performed in an environment having an ambient temperature of 45° C. to 75° C. and applying a pressure of 1 MPa to 2.5 MPa for a time of 5 seconds to 20 seconds.

19. 15. The method of claim 14, wherein the step of heating and pressing the laminate in the second press unit is performed in an environment in which the ambient temperature is 50° C. to 90° C. and a pressure in the range of 1 MPa to 6 MPa is applied for 5 seconds to 60 seconds.

20. 1. An apparatus for manufacturing an electrode assembly for manufacturing a laminate including a first electrode, a second electrode, a first electrode portion of a separator based on the first electrode, and a second electrode portion of a separator between the first electrode and the second electrode, a stack table configured to support the stack; a separation membrane supply device configured to supply the separation membrane to the stack table; a first electrode supplying unit configured to stack the first electrode on a first electrode portion of the separation membrane supported by the stack table; a second electrode supplying unit configured to stack the second electrode on a second electrode portion of the separation membrane supported by the stack table; a gripper configured to secure the laminate; a first press section configured to apply heat and pressure to the laminate secured by the grippers; and a second press section configured to heat and press the laminate; An apparatus for manufacturing an electrode assembly, comprising:

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