Induction heating apparatus, method for manufacturing an electrode assembly containing the same, and apparatus for manufacturing an electrode assembly containing the same

Abstract

In order to solve the problems caused by inconsistent adhesive strength, the present invention provides an induction heating device including at least one induction heating plate that inductively heats an electrode assembly and an induction heating coil built into the induction heating plate, wherein the induction heating coil includes: a first portion of the induction heating coil forming a winding, serpentine pattern; and a second portion of the induction heating coil extending around the induction heating plate; a method for manufacturing an electrode assembly including the induction heating device; and an apparatus for manufacturing an electrode assembly including the induction heating device.

Description

Technical Field

[0001] The present invention claims the benefit of the filing dates of Korean Patent Application No. 10-2023-0058195 filed with the Korean Intellectual Property Office on May 4, 2023, and Korean Patent Application No. 10-2024-0047755 filed with the Korean Intellectual Property Office on April 9, 2024, and all of its contents are included herein.

[0002] The present invention relates to an induction heating device, a method for manufacturing an electrode assembly including the same, and a manufacturing apparatus for an electrode assembly including the same.

Background Art

[0003] Unlike primary batteries, secondary batteries are rechargeable and have been extensively researched and developed in recent years due to their potential for miniaturization and high capacity. As the technology development and demand for mobile devices increase, the demand for secondary batteries as an energy source has been rapidly increasing.

[0004] Secondary batteries are classified into coin-type batteries, cylindrical batteries, prismatic batteries, and pouch-type batteries according to the shape of the battery case. The electrode assembly installed inside the battery case in a secondary battery is a power generation element capable of charge and discharge in the form of a laminated structure of electrodes and a separator.

[0005] The electrode assembly can be generally classified into a jelly-roll type in which a separator is interposed between sheet-shaped positive and negative electrodes coated with active materials and wound, a stack type in which a number of positive and negative electrodes are sequentially laminated with a separator interposed therebetween, and a stack-and-folding type in which unit cells of the stack type are wound with a long separation film.

[0006] Here, in the stack-and-folding type electrode assembly, the separator is folded and laminated in a zigzag shape, and an electrode of the positive or negative electrode is inserted between the folded separators, thereby manufacturing an electrode assembly in a form in which the positive electrode, the separator, and the negative electrode are laminated.

[0007] In this process, heat and pressure are applied to the laminate, which is a stack of the positive electrode, the separation membrane, and the negative electrode, in order to bond the electrodes and the separation membrane together.

[0008] However, applying heat and pressure to the laminate to bond the electrodes (positive electrode, negative electrode) and the separation film within the laminate requires a long time and a lot of energy.

[0009] Furthermore, when heat and pressure were applied to the laminate, there was a problem in that the heat and pressure could not be applied uniformly regardless of the stacking position of the electrodes and the separation membrane due to the difference in stacking positions (stack height) of the electrodes and the separation membrane within the laminate. In other words, a problem arose in which the adhesive force between the separation membrane and the electrodes was not constant.

[0010] As a result, there was a problem with the performance of the electrode assembly becoming inconsistent.

[0011] To solve this problem, a method of induction heating the laminate containing electrodes and a separation membrane was considered, but there was a problem in that it was difficult to ensure the desired level of temperature uniformity depending on the form of the coil used for induction heating.

[0012] Therefore, research is needed on induction heating coil configurations to ensure temperature uniformity. [Prior art documents] [Patent Documents]

[0013] [Patent Document 1] Korean Published Patent Publication No. 10-2013-0132230 [Overview of the project] [Problems that the invention aims to solve]

[0014] The present invention aims to provide an induction heating device for resolving problems caused by inconsistent adhesive strength, a method for manufacturing an electrode assembly including the same, and an apparatus for manufacturing an electrode assembly including the same. [Means for solving the problem]

[0015] One embodiment of the present invention provides an induction heating device comprising at least one induction heating plate having a main surface along its longitudinal and widthwise directions for induction heating an electrode assembly, and an induction heating coil incorporated in the induction heating plate, wherein the induction heating coil comprises a first portion of the induction heating coil having a meandering pattern that curves in the thickness direction perpendicular to the main surface of the induction heating plate to a first depth, and a second portion of the induction heating coil extending around the induction heating plate to a second depth in the thickness direction perpendicular to the main surface of the induction heating plate.

[0016] One embodiment of the present invention provides a method for manufacturing an electrode assembly comprising a first electrode, a separation membrane, and a second electrode, comprising: a stacking step of stacking the laminate comprising the first electrode, the separation membrane, and the second electrode on a stacking table; an induction heating step of induction heating the laminate using an induction heating device; and a heat press step of heating and pressurizing the induction heated laminate.

[0017] One embodiment of the present invention provides an electrode assembly manufacturing apparatus for manufacturing an electrode assembly comprising a first electrode, a separation membrane, and a second electrode, comprising: a stack table on which the first electrode, separation membrane, and second electrode are stacked and the stack comprising the first electrode, separation membrane, and second electrode is placed; a heat press section for heating and pressurizing the stack; and an induction heating section for induction heating the stack before heating and pressurizing the stack in the heat press section, wherein the induction heating section is an induction heating device. [Effects of the Invention]

[0018] The induction heating device according to an embodiment of the present application can transfer heat uniformly during the process of manufacturing an electrode assembly and can reduce temperature unevenness.

[0019] The induction heating device according to an embodiment of the present application can be applied to electrode assemblies of various sizes and has process advantages.

[0020] The method for manufacturing an electrode assembly and the manufacturing device for an electrode assembly according to an embodiment of the present application can shorten the time for manufacturing the electrode assembly.

[0021] The method for manufacturing an electrode assembly and the manufacturing device for an electrode assembly according to an embodiment of the present application can easily adjust the temperature of the electrodes within a specific temperature range and can reduce the temperature deviation between the electrodes, thus providing an electrode assembly with uniform performance.

[0022] [[ID=

[16] ]The electrode assembly according to an embodiment of the present application has the advantage that the variation in the air permeability of the separation membrane due to position is small and the performance is uniform.

Brief Description of the Drawings

[0023] <舍 [Figure 1] It is a diagram exemplarily showing a conventional induction heating device. [Figure 2] It is a diagram showing the transfer pattern of an electrode assembly manufactured using a conventional induction heating device. [Figure 3] It is a diagram exemplarily showing an induction heating device according to an embodiment of the present invention. [Figure 4] It is a diagram exemplarily showing an induction heating device according to an embodiment of the present invention. [Figure 5] It is a diagram showing the transfer pattern and adhesion force pattern of an electrode assembly manufactured using an induction heating device according to an embodiment of the present invention. [Figure 6] It is a plan view exemplarily showing a manufacturing device for an electrode assembly according to an embodiment of the present invention. [Figure 7] It is a front view showing the concept of a manufacturing device for an electrode assembly according to an embodiment of the present invention. [Figure 8] This is a cross-sectional view illustrating a typical electrode assembly. [Figure 9] This figure illustrates the process by applying a method or apparatus for manufacturing an electrode assembly according to one embodiment of the present invention. [Figure 10] This figure illustrates the process by applying a method or apparatus for manufacturing an electrode assembly according to one embodiment of the present invention. [Figure 11] (a) is a perspective view showing a first heat press section 50 according to one embodiment of the present invention, and (b) is a perspective view showing a second heat press section 60 according to one embodiment of the present invention. [Modes for carrying out the invention]

[0024] The present invention will be described in detail below so that it can be easily implemented by a person with ordinary skill in the art to which the present invention pertains. However, the present invention can be embodied in a variety of different forms and is not limited to the configuration described herein.

[0025] Wherever a part of this specification is said to "include" a component, this means, unless otherwise stated, that it may include other components rather than excluding them.

[0026] In one embodiment of the present invention, the electrode assemblies may be stacked in such a manner that the first electrode and the second electrode are alternately arranged between the folding separation membranes.

[0027] In this specification, stacking the first electrode and the second electrode alternately between the folded separation membranes is referred to as zigzag stacking.

[0028] In this context, to give a more specific explanation of the configuration in which the first electrode and the second electrode are alternately arranged between the folded separation membranes, the folded separation membrane can mean a separation membrane in which the separation membranes are stacked in a zigzag pattern. More specifically, the separation membrane is folded in a manner that alternately moves back and forth between the left side and the right side of the stacking axis with respect to the stacking axis, and is stacked in a zigzag pattern. This means that the first electrode and the second electrode are stacked alternately between the stacked separation membranes. Here, the stacking axis means a virtual axis that is parallel to the direction in which the first electrode, the separation membrane and the second electrode are stacked, and passes through the center of the stacked material in which the electrodes and separation membranes are stacked.

[0029] In other words, the arrangement of the first electrode and the second electrode alternately between the separation membranes means that the separation membranes overlap in a zigzag pattern and are stacked in the direction of the stacking axis, and that one first electrode and one second electrode are alternately inserted into the space (between the separation membranes) created by the overlapping of the separation membranes.

[0030] <Induction heating device> One embodiment of the present invention provides an induction heating device including an induction heating coil. The induction heating device according to one embodiment of the present invention may include an induction heating coil and an induction heating plate.

[0031] The induction heating plate according to the present invention has a main surface along the longitudinal and width directions and is characterized by inductively heating an electrode assembly.

[0032] The induction heating apparatus according to the present invention may have the following characteristics: when the induction heating plate is viewed from above, that is, when the first portion of the induction heating coil has a winding, serpentine pattern in the thickness direction perpendicular to the main surface of the induction heating plate to a first depth, and the second portion of the induction heating coil extends along the circumference of the induction heating plate in the thickness direction perpendicular to the main surface of the induction heating plate to a second depth.

[0033] In one embodiment of the present invention, the main surface of the induction heating plate may be positioned to face the electrode assembly that is to be induction heated, and the first and second portions of the induction heating coil may extend in a direction parallel to the main surface of the induction heating plate.

[0034] In one embodiment of the present invention, "first depth" or "second depth" refers to a predetermined depth that is a certain distance away from the main surface of the induction heating plate in the thickness direction (or depth direction) perpendicular to the main surface, and the first depth and the second depth may be the same or different. Referring to Figure 3(d), the first part 191a of the induction heating coil is separated from the main surface (not shown) of the induction heating plate 192 by a distance t1 in the thickness direction perpendicular to the main surface, and this t1 can be called the first depth. The second part 191b of the induction heating coil is separated from the main surface (not shown) of the induction heating plate 192 by a distance t2 in the thickness direction perpendicular to the main surface, and this t2 can be called the second depth. Referring to Figure 3(c) or Figure 3(d), t1 and t2 are different from each other, and although not shown, referring to Figure 4(c), t1 and t2 are the same.

[0035] In one embodiment of the present invention, the first depth and the second depth are different from each other, and the induction heating coil may further include a third portion that connects the first portion of the induction heating coil and the second portion of the induction heating coil to each other. That is, the first portion of the induction heating coil may be arranged on a plane different from that of the second portion of the induction heating coil and connected to each other by the third portion of the induction heating coil. In this case, the first portion and the second portion of the induction heating coil may be connected by the third portion of the induction heating coil and form an integrated unit. The above features make it possible to optimize induction heating of the electrode assembly. Optimizing induction heating means that a transfer pattern, i.e., a mark, that occurs when a particular part of the electrode assembly is heated more than the other is not generated, and that the assembly can be heated uniformly.

[0036] An induction heating device according to one embodiment of the present invention may be used in the manufacture of an electrode assembly.

[0037] In one embodiment of the present invention, the at least one induction heating plate may include a first induction heating plate on which an electrode assembly comprising a positive electrode, a negative electrode, and a separation membrane disposed between the positive and negative electrodes is placed; and a second induction heating plate disposed opposite to the first induction heating plate. In this case, the first induction heating plate may be a lower heating plate, and the second induction heating plate may be an upper induction heating plate.

[0038] In one embodiment of the present invention, the induction heating device may have at least one of the first induction heating plate and the second induction heating plate incorporating the induction heating coil. Alternatively, both the first induction heating plate and the second induction heating plate may have the induction heating coil incorporated.

[0039] In another embodiment of the present invention, the first depth and the second depth may be the same, meaning that the second portion of the induction heating coil is arranged on the same plane as the first portion of the induction heating coil. In this case, the second portion of the induction heating coil can be avoided from short-circuiting with the first portion of the induction heating coil. That is, the second portion can cross the first portion on the same plane while avoiding physical contact with the first portion.

[0040] In one embodiment of the present invention, when the second portion of the induction heating coil is arranged on the same plane as the first portion of the induction heating coil, the first portion and the second portion are in a continuous configuration. That is, the first portion and the second portion are connected.

[0041] In one embodiment of the present invention, the induction heating coil further includes a third portion of the induction heating coil connecting the first portion and the second portion of the induction heating coil, wherein, when viewed from the thickness direction perpendicular to the main surface of the induction heating plate, the second portion of the induction heating coil may cross the first portion of the induction heating coil such that it overlaps with the apex formed on the first portion of the induction heating coil. That is, the induction heating coil may have a two-layer structure consisting of an upper layer and a lower layer. Here, the upper layer may correspond to the layer on which the first portion of the induction heating coil is arranged, and the lower layer may correspond to the layer on which the second portion of the induction heating coil is arranged.

[0042] One embodiment of the present invention provides an induction heating device comprising: a lower induction heating plate on which a heating object is placed on one side; an upper induction heating plate having a surface facing one side of the lower induction heating plate; and an induction heating coil provided inside at least one of the lower induction heating plate and the upper induction heating plate, wherein the induction heating coil has a two-layer structure of an upper layer and a lower layer, and the upper layer of the induction heating coil has a winding, serpentine pattern when viewed in the direction of one side of the lower induction heating plate.

[0043] In one embodiment of the present invention, the third portion of the induction heating coil may be arranged to extend in the height direction (or thickness direction) of the induction heating plate so as to connect the first portion and the second portion of the induction heating coil, which are arranged on different planes, to each other. That is, the third portion of the induction heating coil may extend in the height direction of the induction heating plate. Of course, the third portion of the induction heating coil can also be arranged vertically, which is the height direction of the induction heating plate, and can also extend in an oblique direction.

[0044] The lower layer on which the second portion of the induction heating coil is arranged can be horizontal to the upper layer on which the first portion of the induction heating coil is arranged, meaning that the upper layer and the lower layer of the induction heating coil can be separated. In other words, even when there is a two-layer structure, the first portion and the second portion of the induction heating coil are arranged on different planes so as not to short-circuit each other.

[0045] In one embodiment of the present invention, the length of the third portion may be 0 mm or more. More specifically, it may be 0 mm or more and 40 mm or less, but the upper limit of the length may vary depending on the size of the induction heating plate.

[0046] In this case, the third portion having a length of 0 mm means that the first and second portions of the induction heating coil are arranged on the same plane, and the third portion having a length exceeding 0 mm means that the first and second portions of the induction heating coil have a two-layer structure.

[0047] In one embodiment of the present invention, the first portion and the second portion of the induction heating coil may be connected. In this case, if a two-layer structure is present, a third portion of the induction heating coil may be further included. For example, in the case of a two-layer structure, the first portion of the induction heating coil has a winding, meandering pattern from the starting point to the end of the first portion. Then, at the last end of the first portion of the induction heating coil, the induction heating coil extends perpendicularly in the direction of the second portion of the induction heating coil. In this case, the perpendicularly extending coil represents the third portion of the induction heating coil. At the last end of the third portion of the induction heating coil, the induction heating coil may extend in the direction of the starting point of the first portion of the induction heating coil to form the second portion of the induction heating coil.

[0048] In one embodiment of the present invention, the second portion of the induction heating coil may extend along the induction heating plate with a second depth in a thickness direction perpendicular to the main surface of the induction heating plate, and this may cross the first portion of the induction heating coil so as to overlap with the apex formed in the first portion of the induction heating coil, or it may surround the edge of the first portion of the induction heating coil.

[0049] The shape of the second portion of the induction heating coil is not limited, as long as it can cross the first portion of the induction heating coil so as to overlap with the apex formed in the first portion of the induction heating coil. However, in the case of a two-layer structure, having a linear shape is preferable because it can reduce manufacturing costs.

[0050] Furthermore, if the induction heating coil does not have a two-layer structure, the third portion of the induction heating coil is not necessary. Also, the shape of the second portion of the induction heating coil is not limited as long as it is not short-circuited with the first portion of the induction heating coil and crosses the first portion of the induction heating coil so as to overlap with the apex formed on the first portion of the induction heating coil when viewed from the thickness direction perpendicular to the main surface of the induction heating plate. However, it is preferable that the second portion of the induction heating coil has a larger linear portion, as this can reduce manufacturing costs.

[0051] Here, the second part of the induction heating coil is positioned to cross the first part of the induction heating coil. However, "crossing" does not necessarily mean that it must overlap with the first part of the induction heating coil when viewed from the thickness direction perpendicular to the main surface of the induction heating plate. That is, when viewed from the thickness direction perpendicular to the main surface of the induction heating plate, the second part of the induction heating coil can cross in a way that overlaps with the first part of the induction heating coil, but it can also cross in a way that surrounds the outer perimeter of the first part of the induction heating coil. In other words, when viewed from a plane, they may not overlap.

[0052] In one embodiment of the present invention, when viewed from the thickness direction perpendicular to the main surface of the induction heating plate, the second induction heating portion may surround the edge of the first portion of the induction heating coil.

[0053] In one embodiment of the present invention, the first portion of the induction heating coil and the second portion of the induction heating coil may form at least one closed curve when viewed from the thickness direction perpendicular to the main surface of the induction heating plate.

[0054] In one embodiment of the present invention, the at least one induction heating plate may contain a non-conductive material. That is, in one embodiment of the present invention, at least one of the first induction heating plate and the second induction heating plate may contain a non-conductive material.

[0055] The induction heating plate may include an AC generator that supplies alternating current to the induction heating coil, and can perform a function to protect the induction heating coil. Using a non-conductive material for the induction heating plate is to prevent the induced current from the induction heating coil from also being generated on the induction heating plate.

[0056] The induction heating plate may be a mold made of a non-conductive material. The non-conductive material may be epoxy, but is not limited to epoxy.

[0057] Furthermore, the induction heating coil and induction heating plate may consist of a single set.

[0058] The induction heating unit may include an AC generator, but is not limited thereto; any means capable of generating an electromagnetic induction phenomenon in the induction heating coil can be applied.

[0059] In one embodiment of the present invention, the first portion of the induction heating coil may move in the longitudinal direction of the induction heating plate while reciprocating in the width direction of the induction heating plate to form a meandering pattern.

[0060] In other words, the first portion of the induction heating coil may be a winding, meandering pattern that is embedded in the induction heating plate and moves back and forth in a zigzag pattern in the width direction of the induction heating plate while moving in the longitudinal direction of the induction heating plate. The winding, meandering pattern may be a configuration in which semi-elliptical shapes are alternately arranged in a continuous manner, with a central axis in the longitudinal direction as the reference, having a longer radius in the direction perpendicular to the central axis, i.e., in the width direction of the heating plate, and a shorter radius along the direction of travel of the central axis, i.e., in the longitudinal direction of the induction heating plate. The central axis means a straight line passing through the center of the winding, meandering pattern in the direction in which the winding, meandering pattern moves.

[0061] In one embodiment of the present invention, the first portion of the induction heating coil forms a semi-elliptical shape while reciprocating in the width direction of the induction heating plate, the semi-elliptical shape having a longer radius in the width direction of the induction heating plate and a shorter radius in the longitudinal direction of the induction heating plate, the longer radius being 50 mm or more and 80 mm or less, and the shorter radius being 10 mm or more and 40 mm or less.

[0062] In one embodiment of the present invention, the semi-elliptical shape may be periodically arranged along the central axis. Also in one embodiment of the present invention, the period of the coil may be 10 mm or more and 30 mm or less, preferably 10 mm or more and 25 mm or less, and more preferably 10 mm or more and 25 mm or less.

[0063] If the above conditions are met, the efficiency of induction heating can be further increased.

[0064] Figure 1 illustrates an existing induction heating device. Referring to Figure 1, the existing induction heating device 90 may include an induction heating coil 91 and an induction heating plate 92. More specifically, induction heating coils 91a and 91b may be built inside induction heating plates 92a and 92b. The existing induction heating device 90 may include a U-shaped induction heating coil 91. The induction heating coils 91a and 91b may be arranged facing each other, and the specific arrangement of the induction heating coils 91 may be as shown in Figure 1, but is not limited thereto. When an alternating current is applied to the induction heating coil 91, an induced current can be generated in the metallic electrodes within the laminate, and the electrodes are heated by the induced current.

[0065] When using existing U-shaped induction heating coils, as shown in Figure 2, the amount of heat transferred to the induction heating coil varies greatly depending on its position.

[0066] Specifically, in the full-width cross-sectional view of the cell in Figure 2, the dark shaded areas extending from the lower left and upper right ends to the center indicate that heat is spreading from the area in contact with the induction heating coil, resulting in a higher temperature. In the full-width cross-sectional view of the cell in Figure 2, the dark shaded areas at the upper left and lower right ends indicate areas where heat has not reached and the temperature has decreased. Thus, because the difference in heat transfer varies depending on the location, it was confirmed that specific transfer patterns appear, as shown in the transfer pattern diagram in Figure 2.

[0067] Figures 3 and 4 show the induction heating device 190 according to the present invention. Figure 3 is an illustrative diagram showing a configuration in which the first part and the second part of the induction heating coil have a two-layer structure, and Figure 4 is an illustrative diagram showing a configuration in which the first part and the second part of the induction heating coil are arranged on the same plane.

[0068] Figure 3(a) shows the configuration of the induction heating coil when the induction heating plate 192 is viewed in plan. Figure 3(b) is a perspective view when the induction heating coil is built into the induction heating plate 192. Figure 3(c) shows the configuration of the induction heating coil when viewed in cross-section of the induction heating plate 192.

[0069] Referring to Figure 3(b), the induction heating coil may consist of three parts. The induction coil 191 may include a first part 191a of the induction heating coil that reciprocates in a zigzag pattern in the width direction of the induction heating plate 192, a second part 191b of the induction heating coil that crosses the first part 191a of the induction heating coil, and a third part 191c of the induction heating coil that connects the first part 191a and the second part 191b of the induction heating coil to each other.

[0070] Assuming that the first portion 191a of the induction heating coil is positioned on a first plane located at a first depth in the thickness direction perpendicular to the main surface of the induction heating plate 192, the second portion 191b of the induction heating coil may be positioned on a plane different from the first plane. This is to prevent short circuits from occurring between the second portion 191b and the first portion 191a of the induction heating coil when they cross each other.

[0071] Therefore, the third portion 191c of the induction heating coil may extend in the depth direction (thickness direction), i.e., the z-axis direction, to connect the first portion 191a of the induction heating coil and the second portion 191b of the induction heating coil.

[0072] In other words, the induction heating coil 191 may have a two-layer structure, or a third portion 191c of the induction heating coil may be connected between the two layers to form a single unit.

[0073] Referring to Figure 3(b), assuming that the first part 191a of the induction heating coil is placed in the upper layer (2 layers) and the second part 191b of the induction heating coil is placed in the lower layer (1 layer), the second part 191b of the induction heating coil can surround the edge of the first part 191a of the induction heating coil in the lower layer.

[0074] In other words, in a plan view, the second portion 191b of the induction heating coil crosses the first portion 191a of the induction heating coil such that it coincides with the vertices of the semi-elliptical meandering pattern formed by the first portion 191a of the induction heating coil.

[0075] As shown in Figure 3(b), the second portion 191b of the induction heating coil wraps around the first portion 191a of the induction heating coil so that it can cross the first portion 191a of the induction heating coil not only along the left edge of the induction heating plate but also along the right edge of the induction heating plate. That is, in a plan view, the second portion of the induction heating can be configured to surround the edge of the first portion of the induction heating coil.

[0076] As a result, referring to Figure 3(a), which is a plan view, in plan view, the first part 191a of the meandering induction heating coil and the second part 191b of the linear induction heating coil can be combined to create a number of closed curves. These closed curves are then arranged so that multiple curves are adjacent to each other in the longitudinal direction of the induction heating plate.

[0077] Each closed curve may constitute a single induction heating unit.

[0078] In one embodiment of the present invention, the first and second portions of the induction heating coil may be shaped differently from those shown in Figures 3(a) and 3(b), and this is not limiting. For example, the first portion of the induction heating coil may be sharply bent at the apex of a semi-elliptical meandering pattern, and may have a sharper shape and reciprocate in a zigzag pattern. As another example, the first meandering pattern formed by the first portion of the induction heating coil may occupy half of the total width of the induction heating plate 192, and the second meandering pattern formed by the first portion of the induction heating coil may occupy half of the total width of the induction heating plate 192, but may be located on the other side of the first meandering pattern. Such an arrangement can increase the surface area occupied by the induction heating coil on the induction heating plate. Furthermore, methods can be considered to design the shape of the second portion of the induction heating coil differently in order to increase or decrease the size of each induction heating unit. For example, the portion of the second part of the induction heating coil that extends longitudinally along the induction heating plate may be positioned off-center relative to the central axis, or the second part of the induction heating coil may be made to reach from one end of the heating plate to the opposite end and then return to the same end, thereby creating a larger parallel portion that extends longitudinally along the second part.

[0079] As a result, in one embodiment of the present invention, an induction heating device is configured such that multiple closed-curve-shaped induction heating units are arranged closely together in the longitudinal direction of the induction heating plate. This configuration allows heating of objects of various sizes regardless of length, as long as the width of the object to be heated remains constant.

[0080] On the other hand, referring to Figure 4, unlike the embodiment shown in Figure 3, the first portion 191a and the second portion 191b of the induction heating coil may be arranged on the same plane.

[0081] In this case, when the second portion 191b of the induction heating coil crosses the first portion 191a of the induction heating coil, the two portions may short-circuit with each other. Therefore, the second portion 191b of the induction heating coil can be designed to avoid the first portion 191a of the induction heating coil at the point where it meets the first portion 191a of the induction heating coil while crossing it.

[0082] As a result, as in the case of Figure 3, referring to the plan view of Figure 4(a), in plan view, the first part 191a of the meandering induction heating coil and the second part 191b of the linear induction heating coil can be combined to form multiple closed curves. These closed curves are then arranged so that multiple curves are adjacent to each other in the longitudinal direction of the induction heating plate.

[0083] Each closed curve may constitute a single induction heating unit.

[0084] Referring to Figures 3 and 4, it can be understood that in a plan view, the cases in which the second part 191b of the induction heating coil and the first part 191a of the induction heating coil overlap each other are limited. However, it is also possible for the second part 191b of the induction heating coil to surround the first part 191a of the induction heating coil while being separated from the edge of the first part 191a by a certain distance.

[0085] In one embodiment of the present invention, the first and second portions of the induction heating coil may be shaped differently from those shown in Figures 4(a) and 4(b), and there are no limitations. For example, the first portion of the induction heating coil may be sharply bent at the apex of a semi-elliptical meandering pattern, having a sharper shape and reciprocating in a zigzag pattern. As another example, the first meandering pattern formed by the first portion of the induction heating coil may occupy half of the total width of the induction heating plate 192, and the second meandering pattern formed by the first portion of the induction heating coil may occupy half of the total width of the induction heating plate 192, but located on the other side of the first meandering pattern. Such an arrangement can increase the surface area occupied by the induction heating coil on the induction heating plate. Furthermore, methods can be considered to design the shape of the second portion of the induction heating coil differently in order to increase or decrease the size of each induction heating unit. For example, the portion of the induction heating coil that extends longitudinally along the induction heating plate can be positioned off-center from the central axis, or the second portion of the induction heating coil can be made to avoid the first portion at each intersection, reaching from one end of the heating plate to the opposite end, and then returning to the first end, thereby creating a larger parallel portion that extends longitudinally along the second portion.

[0086] As a result, as shown in Figure 5, it was confirmed that the laminate could be heated uniformly using the induction heating device according to the present invention.

[0087] In other words, as can be seen in Figure 5, by observing the completed electrode assembly and measuring the adhesive force pattern, it was confirmed that the adhesive force pattern was uniform.

[0088] <Manufacturing method for electrode assemblies> One embodiment of the present invention provides a method for manufacturing an electrode assembly including a first electrode, a separation membrane, and a second electrode, utilizing the induction heating device of the present invention.

[0089] The method for manufacturing an electrode assembly according to the present invention is characterized in that, between the stacking step, which is the step of manufacturing the laminate, and the heat pressing step, which is the step of heating and pressurizing the laminate, the method includes a step of induction heating the laminate.

[0090] The heat press step includes a lower plate on which an electrode assembly to be heated and pressurized is placed and which can be heated, and an upper plate corresponding to the lower plate which can also be heated. The lower plate and the upper plate may be a pair of pressurizing blocks.

[0091] In the heat-press stage, where the electrode assembly is heated and pressurized, electrodes located at the outermost edges of the laminate (the uppermost and lowermost edges of the laminate) are in direct physical contact with the lower and upper plates, and therefore may receive more heat and pressure than electrodes located in the middle of the laminate. This is because the heat-press stage involves heating while applying pressure in physical contact with the uppermost and lowermost edges of the laminate.

[0092] In other words, during the heat pressing stage, the electrodes within the laminate may be heated at different temperatures depending on their location, resulting in different adhesive forces between the electrodes and the separator film depending on their position. As a result, the performance of the electrode assembly may become non-uniform depending on its location.

[0093] Therefore, the method for manufacturing an electrode assembly according to the present invention involves heating a localized area within the laminate, particularly the center, with more heat via an induction heating step. The heat applied to the localized area is then diffused throughout the entire electrode assembly. Furthermore, the electrode assembly is heated and pressurized in a heat press step following the induction heating step, thereby ensuring that the electrode assembly is uniformly heated throughout.

[0094] This reduces the deviation in the air permeability of the separation membrane inside the electrode assembly manufactured by the heat pressing step, and reduces the deviation in adhesive strength between the electrode and the separation membrane, thereby enabling the manufacture of an electrode assembly with uniform performance.

[0095] In one embodiment of the present invention, the stacking step may include the steps of supplying the first electrode to the stacking table; supplying the second electrode to the stacking table; and supplying the separation membrane to the stacking table.

[0096] In this specification, "induction heating" refers to heating an object using the electromagnetic induction phenomenon. In this way, the induced current generated in the object by the electromagnetic induction phenomenon generates Joule heat in the object. Therefore, induction heating is a heating method that can locally heat an object even when it is a certain distance away from the heating element, compared to direct heating methods that heat the object by directly contacting it.

[0097] A coil can be used to perform the aforementioned induction heating, and this can be defined as an "induction heating coil." The induction heating method has the advantage of easily adjusting the heat and time applied to the object being heated. Furthermore, non-contact heating is possible, and the object being heated can be avoided without causing damage.

[0098] In this specification, the "induction heating step" can mean locally heating a laminate using the electromagnetic induction heating phenomenon. The laminate that is locally heated may be an electrode located in the center of the laminate. When using a direct heating method, the uppermost or lowermost electrodes of the electrode assembly may be heated more than the electrodes in the center of the electrode assembly. However, in a method for manufacturing an electrode assembly according to one embodiment of the present invention, the center of the electrode assembly is first selectively heated by the induction heating method, and then the electrode assembly is heated by a direct heating method in the subsequent heat press step, so that the electrode assembly is ultimately heated uniformly.

[0099] In one embodiment of the present invention, the induction heating step involves induction heating of a portion of the laminate, allowing the heat to diffuse throughout the entire laminate and heat the entire laminate.

[0100] In one embodiment of the present invention, the induction heating step can induce heating of a first electrode or a second electrode in the laminate. More specifically, in one embodiment of the present invention, the induction heating step can induce heating of a first electrode or a second electrode located in the center of the laminate. In the heat press step, the first electrode or second electrode located in the center of the laminate may receive relatively less heat than the first electrode or second electrode located on the outermost edge of the laminate. However, by applying heat to the first electrode or second electrode located in the center of the laminate first through the induction heating step, and then proceeding with the heat press step, heat can be applied uniformly throughout the entire laminate.

[0101] In this specification, in addition to induction heating only a portion (local region) of the surface of the laminate, induction heating of the entire surface of the laminate is also possible, but the objective of the present invention can be achieved even if only a portion is induction heated. Furthermore, it can be distinguished from heat pressing in that no pressure is applied to the laminate.

[0102] In one embodiment of the present invention, the induction heating step can proceed for 1 to 60 seconds, preferably 5 to 40 seconds, and more preferably 10 to 30 seconds. The induction heating time can be selected considering the degree to which the electrode assembly is heated unevenly during the heat press stage.

[0103] In one embodiment of the present invention, the induction heating step may be performed by induction heating the laminate using an induction heating coil.

[0104] A method for manufacturing an electrode assembly according to one embodiment of the present invention may include a step of transferring the laminate to a heat press step after the stacking step. In order to transfer the laminate in the transfer step, the laminate may be gripped with a gripper.

[0105] The gripper can maintain its grip on the laminate during the heat pressing stage.

[0106] In one embodiment of the present invention, a method for manufacturing an electrode assembly allows for induction heating of the laminate while it is being transferred from the stacking table to the heat press section.

[0107] More specifically, in one embodiment of the present invention, the induction heating step further includes a transfer step between the stacking step and the heat pressing step in which the laminate is gripped by a gripper including an induction heating coil and the laminate is transferred, and the induction heating step can be carried out with the gripper during the transfer step.

[0108] More specifically, in one embodiment of the present invention, the induction heating step may include the steps of: gripping the laminate with a gripper including an induction heating coil; transferring the gripped laminate to a heat press step; and induction heating the laminate with the induction heating coil of the gripper while the laminate is being transferred.

[0109] In other words, by integrating the induction heating coil into the gripper or attaching it to the gripper, there is no need to provide a separate space for induction heating, and the manufacturing equipment for the electrode assembly can be made more compact.

[0110] On the other hand, in one embodiment of the present invention, the induction heating step further includes a transfer step between the stacking step and the heat pressing step in which the laminate is transferred to an induction heating device including an induction heating coil, and the induction heating step can be carried out in the induction heating device. The induction heating device may be a method commonly used in the art, as long as it can carry out induction heating, or it may be an induction heating device according to the present invention.

[0111] More specifically, in one embodiment of the present invention, the induction heating step may include the steps of: gripping the laminate with a gripper and transferring the gripped laminate to an induction heating device including an induction heating coil; and induction heating the laminate in the induction heating device.

[0112] In other words, the induction heating coil may not be mounted inside or outside the gripper, but rather a separate induction heating device may include the induction heating coil. When a separate induction heating device is used, there is an advantage that the induction heating step can be performed even if the thickness of the laminate including the electrodes and separation membrane is increased.

[0113] Furthermore, when using a separate induction heating device as in the present invention, the electrode tab portion protruding from the electrode can be further heated by the induction heating device, thereby reducing the temperature difference between the electrode tab and the electrode.

[0114] In one embodiment of the present invention, the induction heating step may involve heating the laminate at a temperature of 40°C or higher and 90°C or lower, preferably 50°C or higher and 80°C or lower. When the laminate is induction heated within this temperature range, the laminate can be heated without damaging the electrodes and separation film inside the laminate.

[0115] In one embodiment of the present invention, the induction heating coil may be in contact with or at a certain distance from the laminate.

[0116] The induction heating coil has the advantage of being able to raise the internal temperature of the laminate even when induction heating is performed in a short time, because it can transfer heat to the maximum extent when in contact with the laminate (distance between the laminate and the induction heating coil is 0 mm).

[0117] Furthermore, if the induction heating coil is located at a certain distance from the laminate, there is an advantage in that the heat generated by the induction heating coil can raise the internal temperature of the laminate without damaging it.

[0118] In one embodiment of the present invention, the certain distance may be 15 mm or less. More specifically, in one embodiment of the present invention, the certain distance may be greater than 0 mm and 15 mm or less, preferably 0.05 mm or more and 10 mm or less, and even more preferably 0.3 mm or more and 5 mm or less. When the distance is met, as described above, the electrodes can be inductively heated without damaging the laminate.

[0119] A method for manufacturing an electrode assembly according to one embodiment of the present invention may further include a step of removing the induction heating unit from the path of movement of the electrode assembly before the heat pressing step. This prevents physical collision between the induction heating unit and the heat pressing unit.

[0120] Furthermore, physical collisions between the gripper and the heat press section can also be prevented through the first and second heat press stages described later.

[0121] A method for manufacturing an electrode assembly according to one embodiment of the present invention may further include a waiting step between the induction heating step and the heat press step, in which the laminate is left in the atmosphere for a certain period of time. The atmosphere means that after the induction heating step, induction heating is stopped for a certain period of time, and the body waits for the heat applied to the laminate by induction heating to diffuse throughout the entire laminate.

[0122] The heat transferred to a portion of the laminate during the aforementioned waiting stage can be transferred to the entire laminate. Thus, by intentionally suspending the induction heating of the laminate for a certain period of time before proceeding to the heat press stage, the heat transferred to the laminate by induction heating is allowed to diffuse evenly throughout the entire laminate.

[0123] Then, by heating and pressurizing the laminate through a subsequent heat-pressing stage, the uniformity of the electrode thickness throughout the electrode assembly can be improved.

[0124] In one embodiment of the present invention, the waiting stage may proceed for 3 seconds or more and 60 seconds or less, preferably 5 seconds or more and 45 seconds or less, and more preferably 10 seconds or more and 40 seconds or less.

[0125] When the aforementioned time range is met, sufficient time can be ensured for the heat transferred to a portion of the electrodes inside the laminate by induction heating to be evenly distributed throughout the entire laminate. In other words, if the waiting stage proceeds for less than 3 seconds, the heat transferred to a portion of the laminate is less likely to be transferred to the entire electrode. On the other hand, if the waiting stage proceeds for more than 60 seconds, the temperature of the electrodes, which has risen due to the transferred heat, may cool down, which can lead to a problem where the effect of induction heating is reduced.

[0126] The aforementioned waiting time may be changed depending on the time and temperature range during the subsequent heat pressing stage in which the laminate is heated.

[0127] In one embodiment of the present invention, the step of manufacturing a laminate in which a first electrode and a second electrode are alternately arranged between folding separation membranes may be carried out using techniques commonly used in the art. For example, the step may involve stacking the first electrode on the stack table, covering the first electrode with a separation membrane, then stacking the second electrode on the upper surface of the separation membrane, then folding the separation membrane to cover the second electrode, and subsequently stacking the first electrode on the upper surface of the separation membrane, and repeating this process. In this embodiment, this will be referred to as the zigzag stacking method. In this case, the process of the separation membrane moving while covering the first electrode or second electrode placed on the separation membrane may involve methods such as the stack table moving from side to side, the separation membrane moving from side to side, or the stack table rotating.

[0128] In the zigzag stacking method described above, the holding mechanism can maintain the alignment of the stacked material as it grips the stacked material and the first electrode, second electrode, and separation film are stacked.

[0129] In this specification, "holding mechanism" refers to a mechanism that grips the stacked material placed on the stacking table in order to stack the first electrode or the second electrode in the zigzag stacking method, and is different from a gripper that grips the stacked material during the heat press stage.

[0130] In one embodiment of the present invention, the separation membrane may be supplied in the form of a separation membrane sheet. That is, additionally supplied separation membranes may be supplied in a continuous form. Furthermore, the term "top surface" may mean the surface opposite to the surface on which the separation membrane or electrode is placed on the stack table.

[0131] A method for manufacturing an electrode assembly according to one embodiment of the present invention may include a heat press step of heating and pressurizing the induction-heated laminate, as described above. The heat press step may involve heating the laminate while pressurizing it in the lamination axis direction. The heat press step may also be carried out by a heat press section described later.

[0132] Furthermore, in one embodiment of the present invention, the heat pressing step may include the steps of moving the laminate between a pair of pressure blocks including a press heater; the step of the pair of pressure blocks moving relative to each other in the lamination axis direction to apply surface pressure to the laminate; and the step of heating the laminate.

[0133] The pair of pressure blocks may consist of a lower plate and an upper plate facing the lower plate.

[0134] Furthermore, in one embodiment of the present invention, the heat pressing step may include the steps of moving the laminate between a pair of pressure blocks; the step of moving the pair of pressure blocks in the lamination axis direction to apply surface pressure to the laminate; and the step of heating the laminate with a separately provided press heater.

[0135] In other words, the press heater may be included in the pressurizing block or may be provided in a separate configuration.

[0136] A method for manufacturing an electrode assembly according to one embodiment of the present invention may further include a step of loosening the gripper's grip before the heat pressing step.

[0137] In other words, the step of loosening the gripper's grip may include the step of stopping the pressure applied to the top surface of the laminate by the gripper, and the step of separating the gripper from the laminate.

[0138] Furthermore, the step of moving the laminate between a pair of pressure blocks including a press heater during the heat pressing stage may include not only the case where only the laminate itself is moved, but also the case where the laminate is placed on a stack table and moved together with the stack table. In this case, the objects heated and pressurized by the pair of pressure blocks and the press heater can mean the laminate and the stack table.

[0139] In one embodiment of the present invention, the heat pressing step may involve heating and pressurizing the laminate for 5 to 60 seconds under temperature conditions of 50°C to 90°C and pressure conditions of 0.5 MPa to 6.0 MPa. More preferably, the laminate may be heated and pressurized for 5 to 30 seconds under temperature conditions of 65°C to 90°C and pressure conditions of 1.0 MPa to 6.0 MPa. More preferably, the laminate may be heated and pressurized for 7 to 25 seconds under temperature conditions of 65°C to 85°C and pressure conditions of 3 MPa to 5.5 MPa.

[0140] When heating and pressurizing while satisfying the above conditions, the adhesion between the first electrode and the separation membrane, and between the separation membrane and the second electrode can be improved without damaging the first electrode, the separation membrane, and the second electrode. As a result, the performance of the electrode assembly can be improved.

[0141] In one embodiment of the present invention, the heat pressing step is not performed while the induction heating step is in progress.

[0142] In one embodiment of the present invention, the induction heating step may include the steps of: measuring the temperature distribution on the surface of the laminate; setting the induction heating temperature for the laminate according to the measured temperature distribution; and induction heating the laminate based on the set induction heating temperature. That is, by adjusting the induction heating temperature of the laminate according to the temperature distribution on the upper surface of the laminate being measured, the electrodes can be efficiently induction heated without using unnecessary energy.

[0143] <Manufacturing equipment for electrode assemblies> One embodiment of the present invention provides a manufacturing apparatus for an electrode assembly including a first electrode, a separation membrane, and a second electrode, utilizing the induction heating device of the present invention.

[0144] For reference, a semi-finished state in which the first electrode, separation membrane, and second electrode are repeatedly stacked can be represented as a laminate, and by proceeding with the separation membrane winding process on the semi-finished product, a single distinguishable component can be classified as an electrode assembly.

[0145] The electrode assembly manufacturing apparatus is characterized by including an induction heating section. The induction heating section of the electrode assembly manufacturing apparatus of the present invention performs the induction heating step described above. That is, by using the electrode assembly manufacturing apparatus of the present invention, during the heat pressing step carried out by the heat pressing section, the laminate including the first electrode, the separation membrane, and the second electrode is uniformly heated, and uniform adhesion between each layer in the laminate can be ensured. As a result, variations in separation membrane air permeability, variations in separation membrane film thickness, and variations in adhesion strength depending on the stacking position of the electrode assembly can be reduced, and an electrode assembly with uniform performance can be manufactured while reducing the volume of the electrode assembly. Furthermore, an electrode assembly with increased energy density per unit volume can be manufactured.

[0146] The electrode assembly manufacturing apparatus according to the present invention may further include a separation membrane supply unit for supplying a separation membrane to a stack table; a first electrode supply unit for supplying a first electrode to a stack table; and a second electrode supply unit for supplying a second electrode to a stack table.

[0147] In one embodiment of the present invention, the induction heating unit may be a gripper that grips the laminate to transfer it to a heat press unit. The gripper may include an induction heating coil. The induction heating coil may be built inside the gripper as described above, or it may be provided on the outside of the gripper. When the gripper performs the role of an induction heating unit, the process space required for the induction heating unit can be eliminated, and induction heating can be carried out while transferring the laminate, thus shortening the process time. The gripper can perform the function of gripping the laminate while transferring it from the stack table to the heat press unit.

[0148] In one embodiment of the present invention, the induction heating section may be provided separately from the gripper for transporting the laminate. That is, the induction heating section may include an induction heating device including an induction heating coil; and a moving section for moving the induction heating device to the surface of the laminate. Once the moving section moves the induction heating device to an appropriate distance from the laminate, the induction heating device can induce heating of the laminate. When induction heating of the laminate is complete, the moving section can move the induction heating device away from the laminate.

[0149] In this case, as mentioned above, it has the advantage of being easy to apply even with thick laminates, and it can also be used when inductively heating electrode tabs.

[0150] In this specification, "part" means an interface that performs a specific function within an electrode assembly manufacturing apparatus.

[0151] The induction heating coil in the electrode assembly manufacturing apparatus according to one embodiment of the present invention may be in contact with or at a certain distance from the laminate. In this case, the certain distance may be 15 mm or less, more specifically greater than 0 mm and 15 mm or less, preferably 0.05 mm or more and 10 mm or less, and even more preferably 0.3 mm or more and 5 mm or less.

[0152] The advantages of the induction heating coil being in contact with the laminate and the advantages of the induction heating coil being at a certain distance from the laminate are as described in the method for manufacturing the electrode assembly.

[0153] An apparatus for manufacturing an electrode assembly according to one embodiment of the present invention may further include a control unit that measures the temperature distribution on the surface of a laminate and sets an induction heating temperature for the laminate according to the measured temperature distribution, or determines whether or not to interrupt induction heating of the laminate based on the induction heating temperature and the induction heating time for the laminate.

[0154] Furthermore, the control unit can also adjust the induction heating time for the laminate.

[0155] In other words, the control unit can set the conditions for proceeding with the induction heating stage and the standby stage. The conditions described above in the method for manufacturing the electrode assembly can be applied to each of these conditions.

[0156] In one embodiment of the present invention, the heat press section may consist of a pair of pressure blocks, and the pair of pressure blocks may move in directions opposite to each other to apply surface pressure to the laminate.

[0157] The heat press section includes a pair of pressure blocks and a press heater for heating the pressure blocks. As the press heater heats the pressure blocks, the pair of pressure blocks move in a direction facing each other, allowing surface pressure to be applied to the laminate placed between the pressure blocks.

[0158] In this case, the pair of pressure blocks may include a press heater inside.

[0159] In another embodiment of the present invention, the heat press section may consist of two divided heat press sections, that is, a first heat press section and a second heat press section.

[0160] Referring to Figure 7, the first heat press section may include a pair of first pressure blocks. The pressure surfaces of the pair of first pressure blocks may include grooves corresponding to the grippers so that the grippers can press the laminate while gripping it. The pressure surfaces other than the grooves may be flat. The second heat press section may include a pair of second pressure blocks. The pressure surfaces of the pair of second pressure blocks may be flat. That is, when the laminate is placed on the pressure surfaces of the pressure blocks, the second pressure blocks can move relative to each other to heat and pressurize the laminate.

[0161] Dividing the heat press section into two parts as described above allows the heated laminate to cool while being transported, preventing the loss of adhesive strength between each layer within the laminate.

[0162] The conditions for heating and pressurizing the laminate in the heat press section are the same as those for the heat press stage described above.

[0163] In one embodiment of the present invention, the stacking table may include a table body on which the stacked material is placed and a drive unit for driving the table body. The table body may include a stacking table heater that can heat the stacked material to a predetermined temperature when the stacked material is placed on it.

[0164] In one embodiment of the present invention, the first electrode supply unit may include at least one of a first electrode mounting table, a first electrode roll, a first cutter, a first conveyor belt, and a first electrode supply head.

[0165] Furthermore, the first electrode mounting table may include a first electrode heater that heats the first electrode placed on the first electrode mounting table to a predetermined temperature.

[0166] In one embodiment of the present invention, the second electrode supply unit may include at least one of a second electrode mounting table, a second electrode roll, a second cutter, a second conveyor belt, and a second electrode supply head.

[0167] Furthermore, the second electrode mounting table may include a second electrode heater that heats the second electrode placed on the second electrode mounting table to a predetermined temperature.

[0168] In one embodiment of the present invention, the first electrode stacking unit may include a first suction head for vacuum-applying the first electrode placed on the first electrode placement table. The first electrode can be moved from the first electrode placement table to the stacking table via the first electrode stacking unit.

[0169] The second electrode stacking section may include a second suction head for vacuum-applying the second electrode placed on the second electrode mounting table. The second electrode can be moved from the second electrode mounting table to the stacking table via the second electrode stacking section.

[0170] In one embodiment of the present invention, the first electrode may be a positive electrode and the second electrode may be a negative electrode.

[0171] In one embodiment of the present invention, the first electrode may be a negative electrode and the second electrode may be a positive electrode.

[0172] In one embodiment of the present invention, the current collector, active material, conductive material, etc. used in the positive electrode and negative electrode can be any material known in the industry without limitation, and the method for manufacturing the positive electrode and negative electrode can also be any method known in the industry without limitation.

[0173] In one embodiment of the present invention, the separation membrane may be any active material known in the industry without limitation, and the method for manufacturing the separation membrane may also be any method known in the industry without limitation. However, in one embodiment of the present invention, the separation membrane comprises a porous polymer substrate and an organic / inorganic composite porous coating layer formed on at least one surface of the polymer substrate, and the organic / inorganic composite porous coating layer may contain particulate binder resin and inorganic particles.

[0174] In one embodiment of the present invention, the particulate binder resin may contain one or more selected from the group consisting of fluorine-based polymers, acrylic polymer particles, acrylic polymer particles, and hybrid polymer particles of acrylic polymers.

[0175] In one embodiment of the present invention, the fluorine-based polymer may be a homopolymer of vinylidene fluoride, a copolymer of vinylidene fluoride and another polymerizable monomer, or a mixture of two or more thereof.

[0176] In one embodiment of the present invention, the inorganic particles may be Al2O3, but are not limited thereto.

[0177] Because it includes the aforementioned organic / inorganic composite porous coating layer, it is possible to manufacture an electrode assembly with enhanced adhesion between the electrode and the separation membrane by applying the induction heating step and heat pressing step described in the method for manufacturing an electrode assembly and / or the apparatus for manufacturing an electrode assembly.

[0178] The following describes in more detail an apparatus for manufacturing an electrode assembly and a method for manufacturing an electrode assembly, which are embodiments of the present invention. The following description assumes that the electrode assembly of the present invention is zigzag stacked.

[0179] Figure 6 shows a cross-sectional view of the process flow of an electrode assembly manufacturing apparatus according to one embodiment of the present invention, and Figure 7 shows a plan view of the process flow of an electrode assembly manufacturing apparatus according to one embodiment of the present invention. For convenience, Figure 6 omits the holding mechanism 170, heat press section 180, and induction heating device 190 shown in Figure 7, and Figure 7 omits the separation membrane supply section 120 shown in Figure 6.

[0180] Referring to Figures 6 to 8, the electrode assembly manufacturing apparatus 100 according to one embodiment of the present invention includes a separation membrane supply unit 120 for supplying a separation membrane 14 to a stack table 110, a first electrode supply unit 130 for supplying a first electrode 11 to the stack table 110, and a second electrode supply unit 140 for supplying a second electrode 12 to the stack table 110. In this case, the separation membrane 14, the first electrode 11, and the second electrode 12 may be heated in the first electrode supply unit 130 and the second electrode supply unit 140, respectively, before being supplied to the stack table 110.

[0181] Furthermore, the electrode assembly manufacturing apparatus 100 according to one embodiment of the present invention includes a first electrode stacking section 150 for stacking the first electrode 11 supplied by the first electrode supply section 130 onto the stacking table 110, and a second electrode stacking section 160 for stacking the second electrode 12 supplied by the second electrode supply section 140 onto the stacking table 110. In this case, the separation membrane 14 supplied by the separation membrane supply section 120 is stacked in a zigzag pattern, alternating between the left and right sides of the stacking axis with respect to the stacking axis. In this case, either the first electrode 11 or the second electrode 12 is alternately inserted into the space (between the separation membranes) created by the folding of the separation membrane 14, and as a result, a stack in which the first electrode 11, separation membrane 14, second electrode 12, and separation membrane 14 are repeatedly stacked is placed on the stacking table 110.

[0182] The separation membrane supply unit 120 may include a separation membrane heating unit 121 and a separation membrane roll 122. The separation membrane heating unit 121 is selectively applicable.

[0183] More specifically, the first electrode supply unit 130 may include a first electrode mounting table 131, a first electrode heater (not shown), a first electrode roll 133, a first cutter 134, a first conveyor belt 135, and a first electrode supply head 136. The first electrode heater (not shown) is selectively applicable.

[0184] Furthermore, the second electrode supply unit 140 may include a second electrode mounting table 141, a second electrode heater (not shown), a second electrode roll 143, a second cutter 144, a second conveyor belt 145, and a second electrode supply head 146. The second electrode heater (not shown) is selectively applicable.

[0185] The first electrode stacking section 150 stacks the first electrode 11 on the stacking table 110. In this case, the first electrode stacking section 150 may include a first suction head 151, a first head heater (not shown), and a first moving section 153. The second electrode stacking section 160 stacks the second electrode 12 on the stacking table 110. The second electrode stacking section 160 may include a second suction head 161, a second head heater (not shown), and a second moving section 163.

[0186] The first electrode stack section 150 and the second electrode stack section 160 may optionally further include a heater (not shown) for preheating the first and second electrodes.

[0187] Furthermore, the electrode assembly manufacturing apparatus 100 according to one embodiment of the present invention may further include a holding mechanism 170 for fixing the first electrode 11 and the second electrode 12 when they are stacked on the stack table 110. In addition, the electrode assembly manufacturing apparatus 100 according to one embodiment of the present invention includes a heat press section 180 for heating and pressurizing the stack placed on the stack table 110 to bond the first electrode 11, the separation membrane 14, and the second electrode 12 together.

[0188] Furthermore, the electrode assembly manufacturing apparatus 100 according to one embodiment of the present invention further includes an induction heating device 190 that induces heating of a laminate to transfer heat to electrodes within the laminate. It may also further include a control unit (not shown) that controls whether or not the induction heating unit 190 operates. As a result, an electrode assembly 10 as shown in Figure 8 can be manufactured.

[0189] Figure 8 is a cross-sectional view illustrating an electrode assembly manufactured by an electrode assembly manufacturing apparatus and electrode assembly manufacturing method according to one embodiment of the present invention.

[0190] Referring to Figure 8, the electrode assembly 10 may be configured in which a separation membrane folded in a zigzag shape and stacked is alternately inserted and stacked with a first electrode or a second electrode inserted into the space between the separation membranes.

[0191] In this case, the electrode assembly 10 may be provided in a form in which the outermost layer of the laminate is enclosed by the separation membrane 14. However, the configuration of the electrode assembly 10 is not limited to the example shown in Figure 8.

[0192] Figures 9 and 10 schematically illustrate the operation process of the induction heating unit according to the present invention.

[0193] Specifically, Figure 9 shows the case where the induction heating unit 190 is a gripper 51. The gripper 510 may include an induction heating coil (not shown). The gripper 51 can perform induction heating on the laminate S while gripping it. The laminate S may be transferred to the heat press unit 180 while induction heating is being performed by the gripper 51. In the heat press unit 180, the laminate S can be heated and pressurized. In this case, before heating and pressurizing the laminate S in the heat press unit 180, a waiting process (stage) may be performed in which induction heating on the laminate S is stopped and the laminate S is left waiting for a certain period of time. In this case, the conditions for the waiting process may be set by a control unit (not shown).

[0194] Figure 10 shows another embodiment of induction heating, in which the laminate S is induction heated using an induction heating device 190 provided separately from the gripper 51. In this case, the laminate S is moved to the induction heating device and then induction heated. Once induction heating is complete, the laminate S can be heated and pressurized in the heat press section 180, as in Figure 4. In this case, before heating and pressurizing the laminate S in the heat press section 180, a waiting step (stage) may be performed in which the induction heating of the induction heated laminate S is stopped and the laminate S is left waiting for a certain period of time. In this case as well, the conditions of the waiting step may be adjusted by a control unit (not shown). The waiting step may be performed with the laminate S held by the gripper 51 after being removed from the induction heating section 190, as shown in Figure 5.

[0195] The induction heating section 190 in Figures 9 and 10 may be an induction heating device according to the present invention.

[0196] The present invention is characterized by pre-heating, by induction heating, of the electrodes located in the central part of the active assembly, which is particularly vulnerable to heating, before the heat press stage in which the electrode assembly is heated and pressurized.

[0197] Figure 11 shows the configuration of the heat presses 50 and 60, and in particular shows the case where the heat press sections 50 and 60 comprise a first heat press section 50 and a second heat press section 60.

[0198] Figure 11(a) is a perspective view showing the first heat press section 50, and Figure 11(b) is a perspective view showing the second heat press section 60.

[0199] Referring to Figure 11(a), the first heat press section 50 can heat and pressurize the laminate S while it is fixed by the gripper 51. The first heat press section 50 may consist of a pair of first pressurizing blocks 50a and 50b. The pair of first pressurizing blocks 50a and 50b have flat pressurizing surfaces, except for grooves that correspond to the fixing portion 51b of the gripper 51.

[0200] The gripper 51 may include a body 51a that corresponds to the length x and height y of the laminate S, or is wider than the length x and height y of the laminate S, and a fixing portion 51b that protrudes from the body 51a and grips the laminate S. Here, the length x of the laminate S means the longest distance from one end to the other of the laminate S, the height y means the distance in the stacking direction of the laminate S, and the width z means the distance across the top surface of the laminate S.

[0201] The fixing portion 51b can be adjusted in position along the height direction of the main body 51a, and the fixing portion 51b can contact the upper and lower surfaces of the laminate S to fix the laminate S.

[0202] Subsequently, the pair of first pressurizing blocks 50a and 50b move in opposing directions to heat and pressurize the laminate S. Through this heating and pressurizing, the electrodes and separation membrane inside the electrode assembly are stably bonded together.

[0203] The first heat press section 60 may be a component that complements the cooling of the induction-heated electrode assembly while it moves, and may be provided selectively. In other words, it may be omitted in some cases.

[0204] Referring to Figure 11(b), the second heat press section 60 can ultimately heat and pressurize the laminate S that has been initially heated and pressurized by the first heat press section 50. The second heat press section 60 includes a pair of second pressurizing blocks 60a and 60b, and the pair of pressurizing blocks 61 and 62 are moved in opposing directions to pressurize the laminate S surface. In addition, the pair of second pressurizing blocks 60a and 60b included in the second heat press section 60 may have pressurizing surfaces that contact and pressurize the laminate S that are all flat.

[0205] The description of the method for manufacturing an electrode assembly according to the present invention can also be applied to the apparatus for manufacturing an electrode assembly according to the present invention. The reverse is also true.

[0206] Although embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and it will be obvious to those with ordinary skill in the art that various modifications and variations are possible without departing from the technical idea of ​​the present invention as described in the claims. [Explanation of Symbols]

[0207] 10...electrode assembly 11...1st electrode 12...Second electrode 14...Separation membrane 50 ···First heat press section 50a, 50b...a pair of first pressure blocks 51 ···Grippa 51a ···Main body 51b...Fixed part 60 ···Second heat press section 60a, 60b... A pair of second pressure blocks 90 ···Existing induction heating devices 91 (91a, 91b) ... Induction heating coil 92 (92a, 92b) ... Induction heating plate 100 ··· Electrode assembly manufacturing equipment 110 ···Stackable Table 111 ···Table body 112 ···Stackable Table Heater 120...Separation membrane supply section 121 ···Separation membrane heating section 122 ···Separation membrane roll 130...1st electrode supply section 131 ···First electrode mounting table 133 ···First electrode roll 134 ···First cutter 135 ···First conveyor belt 136 ···First electrode supply head 140...Second electrode supply section 141 ···Second electrode mounting table 143 ···Second electrode roll 144 ···2nd cutter 145 ···Second conveyor belt 146 ···Second electrode supply head 150 ···First electrode stack section 151 ···First suction head 153 ···First Mobile Unit 160 ···Second electrode stack section 161 ···Second suction head 163 ···Second Mobile Unit 170 ···Holding mechanism 171 ···First Holding Organization 172 ···Second Holding Organization 180 ···Heat press section 181 ···First pressurization block 182 ···Second pressurization block 190...Induction heating device 191...Induction heating coil 191a ···First part of induction heating coil 191b...Second part of the induction heating coil 191c ···Third part of the induction heating coil 192 ···Induction heating plate S ···Laminate

Claims

1. An induction heating device comprising at least one induction heating plate having a main surface along the longitudinal and width directions for induction heating an electrode assembly, and an induction heating coil built into the induction heating plate, The induction heating coil is A first portion of an induction heating coil having a meandering pattern that curves to a first depth in the thickness direction perpendicular to the main surface of the induction heating plate; and A second portion of the induction heating coil extending around the induction heating plate with a second depth in the thickness direction perpendicular to the main surface of the induction heating plate. An induction heating device, including one.

2. The induction heating apparatus according to claim 1, wherein the main surface of the induction heating plate is arranged to face the electrode assembly that is to be induction heated.

3. The induction heating apparatus according to claim 1, wherein the first and second portions of the induction heating coil extend in a direction aligned with the main surface of the induction heating plate.

4. The at least one induction heating plate is a first induction heating plate on which the electrode assembly, which includes a positive electrode, a negative electrode, and a separation membrane disposed between the positive electrode and the negative electrode, is placed; and The induction heating apparatus according to claim 1, further comprising a second induction heating plate positioned opposite the first induction heating plate.

5. The induction heating apparatus according to claim 1, wherein the first depth and the second depth are different from each other, and further includes a third portion of the induction heating coil that connects the first portion of the induction heating coil and the second portion of the induction heating coil to each other.

6. The induction heating device according to claim 1, wherein the first depth and the second depth are the same, but the second portion of the induction heating coil is avoided from short-circuiting with the first portion of the induction heating coil.

7. The induction heating apparatus according to claim 1, wherein, when viewed from a thickness direction perpendicular to the main surface of the at least one induction heating plate, the second portion of the induction heating coil crosses the first portion of the induction heating coil such that it overlaps with the vertex formed on the first portion of the induction heating coil.

8. The induction heating apparatus according to claim 1, wherein, when viewed from a thickness direction perpendicular to the main surface of the at least one induction heating plate, the second portion of the induction heating coil surrounds the edge of the first portion of the induction heating coil.

9. The induction heating apparatus according to claim 1, wherein, when viewed from a thickness direction perpendicular to the main surface of the at least one induction heating plate, the first portion of the induction heating coil and the second portion of the induction heating coil form at least one closed curve.

10. The induction heating apparatus according to claim 1, wherein the at least one induction heating plate contains a non-conductive material.

11. The induction heating apparatus according to claim 1, wherein the first portion of the induction heating coil moves in the longitudinal direction of the induction heating plate while reciprocating in the width direction of the induction heating plate to form a meandering pattern.

12. The first portion of the induction heating coil is semi-elliptical in shape, and moves back and forth in the width direction of the induction heating plate. The aforementioned semi-elliptical shape has a longer radius in the width direction of the induction heating plate and a shorter radius in the longitudinal direction of the induction heating plate. The aforementioned long radius is 50 mm or more and 80 mm or less. The induction heating apparatus according to claim 1, wherein the aforementioned short radius is 10 mm or more and 40 mm or less.

13. The induction heating apparatus according to claim 12, wherein the semi-elliptical shape is periodically arranged in the longitudinal direction of the induction heating plate.

14. The induction heating apparatus according to claim 13, wherein the period is 10 mm or more and 30 mm or less.

15. A method for manufacturing an electrode assembly, comprising a first electrode, a separation membrane, and a second electrode, A stacking step in which the laminate including the first electrode, the separation membrane, and the second electrode is stacked on a stacking table; An induction heating step of induction heating the laminate with an induction heating apparatus according to any one of claims 1 to 14; and The heat press stage involves heating and pressurizing the induction-heated laminate. A method for manufacturing an electrode assembly, including [the specified component].

16. An electrode assembly manufacturing apparatus for manufacturing an electrode assembly including a first electrode, a separation membrane, and a second electrode, A stacking table on which the stacked material, including the first electrode, the separation membrane, and the second electrode, is placed; A heat press section for heating and pressurizing the laminate; and Before heating and pressurizing the laminate in the heat press section, an induction heating section is used to induction heat the laminate. Includes, The induction heating unit is an induction heating device according to any one of claims 1 to 14, wherein the apparatus is for manufacturing an electrode assembly.

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