KR101675011B1 - Stack and folding-type electrode assembly and method for fabricating the same - Google Patents

Abstract

A stack-folding type electrode assembly in which electrolyte is uniformly impregnated in a unit cell to improve cycle characteristics, and a method of manufacturing the same. The stack-folding type electrode assembly according to the present invention is an electrode assembly in which a plurality of stacked unit cells are overlapped and a continuous folding separator sheet is interposed in each overlapping portion, And a porous tube is interposed between the separator sheet and the side surface of the unit cell. According to the present invention, the electrolytic solution is uniformly impregnated in the unit cell to improve the battery cycle characteristics, and the vaporized electrolyte or gas generated in the electrode assembly can be easily discharged to the outside.

Description

[0001] Stack-folding electrode assembly and method of fabricating the same [0002]

The present invention relates to a stack-folding type electrode assembly and a method of manufacturing the stack-folding type electrode assembly, and more particularly, to a stack-folding type electrode assembly in which electrolyte is uniformly impregnated in a unit cell to improve battery cycle characteristics, And a manufacturing method thereof.

Due to the development of technology and demand for mobile devices, the demand for secondary batteries is also rapidly increasing. Among them, lithium secondary batteries, which have high energy density, high operating voltage and excellent storage and life characteristics, It is widely used as an energy source.

The secondary battery is roughly classified into a cylindrical battery, a prismatic battery and a pouch-shaped battery according to the structural characteristics of the outside and the inside. Among them, the secondary battery can be stacked with a high degree of integration, and prismatic batteries and pouch- .

The electrode assembly of the anode / separator / cathode structure constituting the secondary battery is largely classified into a jelly-roll type (winding type) and a stack type (laminate type) depending on its structure. In the jelly-roll type electrode assembly, an electrode active material or the like is coated on a metal foil used as a current collector, dried and pressed, cut into a band shape having a desired width and length, and a cathode and an anode are diaphragm- . The jelly-roll type electrode assembly is suitable for a cylindrical battery. However, when applied to a square or pouch type battery, it has disadvantages such as peeling of an electrode active material and low space utilization. On the other hand, the stacked electrode assembly has a structure in which a plurality of positive electrode and negative electrode unit cells are sequentially stacked and has a merit that it is easy to obtain a rectangular shape. However, when the manufacturing process is troublesome and impact is applied, .

In order to solve such a problem, the jelly-roll type and stack type mixed type electrode assemblies have been proposed in which a full cell or a positive electrode (cathode) / separator / cathode (anode) / separator A stack-folding type electrode assembly having a structure in which a bicell having an anode / cathode structure is folded by using a continuous long folding separator sheet has been developed.

FIG. 1 shows a stack-folding type electrode assembly folded from a center of a unit cell to a folding separator sheet according to a related art.

Referring to FIG. 1, a plurality of unit cells 10 are stacked, and a folding separator sheet 20 is interposed in each of the overlapping portions. The folding separator sheet 20 has a unit length capable of wrapping around the unit cell 10 and is folded inward for each unit length to start from the central unit cell 10 to the outermost unit cell 10, And covers the unit cell 10 and is interposed in the overlapping portion of the unit cell 10. The end portion of the folding sheet 20 is finished by the adhesive tape 30 or the like.

In general, the stack-folding type electrode assembly has its outer surface surrounded by the folding separator sheet 20, and the folding separator sheet 20 on the side of the unit cell 10, There is a disadvantage in that the electrolyte injected at the final stage of the battery production reaches the inner unit cell and is not completely wetted and the infiltration rate is slow. This is one of the causes of inefficiently increasing the manufacturing process time of the battery. In addition, when the electrode is not sufficiently wetted with the electrolyte, the SEI film of the negative electrode is not properly formed and the lifetime characteristics of the battery deteriorate. Therefore, conventionally, in order to promote the wetting of the electrolyte solution to the electrode, an additional process such as aging in which the negative electrode is stored in the electrolyte solution for a predetermined time after the electrolyte solution is injected is added, or vacuum or pressure is applied We are trying to solve these problems using special process techniques.

1, when the electrolytic solution is vaporized in an emergency such as high temperature or overcharging, or when gas is generated in the electrode assembly, the folded separator sheet 20 in which vaporized electrolytic solution or gas is stacked in multiple layers, It is difficult to discharge easily, so that the battery is often swollen. At this time, the vaporized electrolytic solution or gas or the like may be discharged in a direction perpendicular to the winding direction (the direction in which the electrode tabs protrude, in the drawing, the direction perpendicular to the paper surface) that is not blocked by the folding separator sheet 20, Etc. are generated more in the central portion of the stack-folding type electrode assembly, there is a limit in that the gas generated at the center is discharged in both directions in which the electrode tabs protrude. Accordingly, the swelling phenomenon of the battery due to the gas and the vaporized electrolyte in the central portion of the stack-folding type electrode assembly is more likely to occur, so that the degree of bending of the electrodes of the positive and negative electrodes of the unit cell is greater In addition, if the battery is in a high-temperature or over-charged state, the separator interposed in the unit cell wears or shrinks. When the battery is in an emergency state of high temperature or overcharge, the electrodes of the unit cell are bent Shrinkage or abrasion of the separator may occur at the same time, so that the positive electrode and the negative electrode come into contact with each other at the end corner of the unit cell to cause a short circuit. Such interelectrode short circuit generates a lot of heat, so that ignition or explosion of the battery may occur, which may seriously lower the safety of the secondary battery.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a stack-folding type electrode capable of enhancing battery cycle characteristics by uniformly impregnating an electrolyte solution in a unit cell and discharging a vaporized electrolyte or gas generated inside the electrode assembly to the outside easily. Assembly and a method of manufacturing the same.

According to an aspect of the present invention, there is provided a stack-folding type electrode assembly comprising a plurality of stacked unit cells overlapping each other, and a continuous folding separator sheet interposed between the stacked unit cells, And a porous tube is interposed between the folding separator sheet wrapped around the cells and the side surface of the unit cell.

The porous tube may be provided on both side surfaces of the central unit cell. The porous tube may be provided on both side surfaces of the unit cell. One end of the porous tube may be open and the other end closed. The unit cell may be a pull cell or a bicycle. The stack-folding type electrode assembly according to the present invention may further include through holes formed on both sides of the folding separator sheet, with respect to a direction in which the electrode tab protrudes. In one embodiment, the folding separator sheet may have a hole formed at a position corresponding to a side surface of the unit cell.

The folding separator sheet may be the same material as the separator constituting the unit cell. The present invention also provides a secondary battery including the stack-folding type electrode assembly.

A method of manufacturing a stack-folding type electrode assembly according to the present invention includes positioning a central unit cell at a first end of a folding separator sheet and successively positioning the unit cells at a predetermined interval in the same electrode alignment manner, Disposing a porous tube; And folding the folded separator sheet to the outside where the adjacent unit cells are located and folding each unit cell by folding the unit cell and the porous tube once with the long length of the folding separator sheet, .

In the stack-folding type electrode assembly manufacturing method according to the present invention, after the folding of the folding separator sheet is completed, forming a through hole on both sides of the folding separator sheet based on the direction in which the electrode tab protrudes .

The through hole may be formed by partially punching a corresponding portion of the folding separator sheet with a needle having a predetermined diameter. In another embodiment, the folding separator sheet may have a hole formed at a position corresponding to a side surface of the unit cell.

In the method of manufacturing a stack-folding type electrode assembly according to the present invention, the porous tube may be compressed during folding.

According to the present invention, by providing a porous tube between the folding separator sheet of the stack-folding type electrode assembly and the side surface of the unit cell, a passage for the electrolytic solution during the activation process of the battery is provided to remarkably improve the impregnation property and impregnation speed . Therefore, the cell making period can be shortened and the battery cycle characteristics can be improved.

In addition, when an abnormal phenomenon such as high temperature and overcharging occurs, vaporized electrolytic solution and gas can be quickly discharged to the outside of the electrode assembly through the porous tube, thereby preventing swelling of the battery, thereby improving the safety and performance of the battery.

In order to help impregnate the electrolyte and discharge the gas, a through hole is formed on the side surface of the folding separator sheet together with the porous tube, or a hole is formed in the folding separator sheet and folded, thereby maximizing the effect of the porous tube. Generally, the side of the electrode assembly is relatively longer than the upper or lower end of the electrode tab. Therefore, when the electrolyte and gas passages are provided on the side of the electrode assembly through the porous tube as in the present invention, the wetting process is further shortened .

FIG. 1 shows a stack-folding type electrode assembly folded from a center of a unit cell to a folding separator sheet according to a related art.
2 is a cross-sectional view of a stack-folding type electrode assembly according to an embodiment of the present invention.
3 is a perspective view of a porous tube included in a stack-folding type electrode assembly according to an embodiment of the present invention.
4 is a cross-sectional view of a stack-folding type electrode assembly according to another embodiment of the present invention.
5 is a cross-sectional view of a stack-folding type electrode assembly according to another embodiment of the present invention.
6 is a cross-sectional view of a stack-folding type electrode assembly according to another embodiment of the present invention.
7 is a view for explaining a method of manufacturing a stack-folding type electrode assembly according to an embodiment of the present invention.
8 is a view for explaining a method of manufacturing a stack-folding type electrode assembly according to another embodiment of the present invention.
9 is a perspective view of a stack-folding type electrode assembly according to another embodiment of the present invention.
10 is a cross-sectional view of a stack-folding type electrode assembly according to another embodiment of the present invention.
11 is a view for explaining a method of manufacturing a stack-folding type electrode assembly according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It is provided to let you know.

In addition, the battery or the electrode assembly included in the present invention is not particularly limited in its shape and may include various shapes. For example, the battery or the electrode assembly may be formed by crossing different types of stacked unit cells, A stack-folding type electrode assembly in which the stacked-folded electrode assembly is wound in a long-cut folded separator sheet, a stack-folding type electrode assembly in the above-described manner, An Z-type stack-electrode assembly for folding the stacked unit cells in a zigzag direction when the stacked unit cells are wound with a folding separator sheet, and the like.

2 is a cross-sectional view of a stack-folding type electrode assembly according to an embodiment of the present invention.

Referring to FIG. 2, a plurality of stacked unit cells 110 are stacked in a stack-folding type electrode assembly 100, and a folding separator sheet 120 is interposed between the stacked unit cells 110 in each stacking unit. The folding separator sheet 120 has a unit length that can cover the unit cell 110 and is bent inward for each unit length to start from the center unit cell 110 and continue to the outermost unit cell 110, And is interposed in the overlapped portion of the unit cell 110 with a structure that surrounds the unit cell 110. [ Further, the distal end portion of the folding sheet 120 is thermally fused or bonded with an adhesive tape 130 or the like.

As described above, in the stack-folding type electrode assembly 100 according to the embodiment of the present invention, a plurality of stacked unit cells 110 are overlapped and a continuous folding separator sheet 120 is interposed therebetween A porous tube 140 is interposed between the folded separator sheet 120 wrapped around the stacked unit cells 110 and the side surface of the stacked unit cell 110. The porous tube 140 may include at least one of the porous tubes 140 extending in a direction parallel to the side surface of the unit cell 110. When the porous tube 140 is symmetrical, And may be provided on both sides. The porous tube 140 may be compressed upon folding. For this, the material of the porous tube 140 is preferably made of a flexible and compressible material like the folding sheet 120.

The unit cell 110 may be a full cell of a positive electrode / separator / negative electrode structure or a bi-cell of a positive electrode (cathode) / separator / cathode (anode) / separator / anode (cathode) structure. The positive electrode is prepared, for example, by applying a mixture of a positive electrode active material, a conductive material and a binder to both surfaces of a positive electrode current collector, followed by drying and pressing, and if necessary, a filler is further added to the mixture. The negative electrode is prepared by applying, drying and pressing an anode active material on an anode current collector, and may optionally further include a conductive material, a binder, a filler, and the like as described above. The number of unit cells 110 such as a pull cell or a bi-cell wound on the folding separator sheet 120 may be varied depending on the structure of each unit cell such as a pull cell or a bi- Lt; / RTI > In FIG. 2, five unit cells 110 are shown for convenience of illustration. However, the number of unit cells 110 included in the stack-folding type electrode assembly 100 may be more than 15, for example, about 15.

The folding separator sheet 120 may be made of the same material as the separator constituting the unit cell 110. The folding separator sheet or separator may be a polyethylene film containing micropores, a polypropylene film, or a multilayer film produced by a combination of these films, and a layered film made of polyvinylidene fluoride, polyethylene oxide, polyacrylonitrile, or polyvinylidene Fluorinated hexafluoropropylene copolymer, and polymer film for a polymer electrolyte of a fluorinated hexafluoropropylene copolymer, and may be a single layer or a multi-layered folding separator sheet or separator film .

3 is a perspective view of a porous tube included in a stack-folding type electrode assembly according to an embodiment of the present invention.

As shown in the figure, the porous tube 140 is a barrel shape extending in one direction and includes many fine holes 142, so that the electrolyte and the gas can smoothly move. The porous tube 140 may be opened at one end and closed at the other end in the electrode assembly. As shown in the drawing, when the electrolyte is injected in the direction of the arrow through the opened end, the electrolyte can be moved in all directions through the fine holes 142. The reason for closing the other end of the porous tube 140 is to allow the electrolyte to move in the circumferential direction in the cross section perpendicular to the long axis of the porous tube 140, that is, in all directions through the fine holes 142. This makes it possible to smoothly impregnate the side surface of the electrode assembly with electrolyte. In addition, when gas is generated in the battery, the battery can be easily discharged to the outside through one opened end of the porous tube 140, thereby improving battery swelling.

As described above, according to the present invention, the porous tube 140 is disposed between the folding separator sheet 120 surrounding the unit cell 110 and the side surface of the unit cell 110, and the porous membrane 140 is formed through the fine holes 142 of the porous tube 140, The electrolyte can be easily impregnated into the interior of the cell, and at the same time, the gas inside the cell is efficiently discharged in the event of instability, thereby enhancing the stability of the cell. The electrode assembly having such a structure has advantages of reducing cell manufacturing time due to improvement of wettability of the cell and discharging the cell pressure constantly in an unsafe situation, thereby preventing shorting or sparking that may occur in the side venting. As a result, it is possible to secure the production period, cost reduction and safety without changing the cell manufacturing process.

The stack-folding type electrode assembly according to the present invention can be a component of a lithium ion secondary battery. The present invention can also be used as a middle- or large-sized battery module that includes such a secondary battery as a unit cell.

4 is a cross-sectional view of a stack-folding type electrode assembly according to another embodiment of the present invention.

The stack-folding type electrode assembly shown in FIG. 4 is different from the stack-folding type electrode assembly 100 shown in FIG. 2 in that the porous tube 140 is provided on both sides of the unit cell 110.

5 is a cross-sectional view of a stack-folding type electrode assembly according to another embodiment of the present invention. As shown in FIG. 5, the porous tubes 140 are arranged alternately in the left and right directions, respectively, while the porous tubes 140 correspond to one unit cell 110 one by one.

6 is a cross-sectional view of a stack-folding type electrode assembly according to another embodiment of the present invention. The stack-folding type electrode assembly shown in FIG. 6 is characterized in that the porous tubes 140 are disposed at positions corresponding to the left lower side and the right upper side with respect to the center unit cell 110, respectively.

2 and 4 to 6, the number and positions of the porous tubes 140 can be changed as desired, and the porous tube 140 can be interposed between the folding separator sheet 120 and the side surface of the stacked unit cell 110 . In order to prevent the electrode assembly from becoming bulky due to the insertion of the porous tube 140, it is preferable to wind the folded sheet 120 to the maximum extent during folding so that the porous tube 140 is contained in the electrode assembly in a compressed state.

7 is a view for explaining a method of manufacturing a stack-folding type electrode assembly according to an embodiment of the present invention. This method can be regarded as a method of manufacturing the stack-folding type electrode assembly 100 as shown in Fig.

First, the positive electrode and the negative electrode are laminated with a separator interposed therebetween, and a plurality of pull cells or bi-cells are cut by a predetermined size to prepare a unit cell 110. After the folding separator sheet 120 is cut and prepared, the unit cells 110 are arranged as shown in FIG. The folding separator sheet 120 has a width slightly larger than that of the unit cell 110 while exposing the electrode tab T of the unit cell 110 and may have an extended length that covers the electrode assembly once after being wound, The outermost end of the separator sheet 120 can be fixed by heat-sealing or taping. For example, the folding separator sheet 120 itself can be melted and adhered and fixed by contact with a folding separator sheet 120 to be finished, such as a heat welder or a hot plate, have.

The unit cell 110 placed at the front end of the folding separator sheet 120 is the central unit cell and the space 121 is the unit cell width (including the unit cell thickness). Reference numerals 122, 123, and 124 denote spaces spaced apart by a degree that the thickness (including the thickness of the unit cell) increases while rolling. As the unit cells 110 are sequentially folded, the folding thickness increases, so that the distance that the unit cells 110 face is gradually widened.

Since the folding separator sheet 120 is formed in such a manner that the electrode tabs T are formed facing opposite ends of the battery, the same poles may be arranged side by side when the cells are arranged. If the electrode tabs are formed side by side on one end of the battery, the mounting surface of the unit cell should be arranged so that the polarities of the electrode tabs match each other. That is, the first and second unit cells are positioned on the folding separator sheet 120 in the order of the positive electrode and the negative electrode, and the third or more unit cells are arranged such that the electrode direction is opposite to the electrode direction of the preceding unit cell Respectively. In this manner, the unit cells 110 are successively positioned in the same electrode alignment manner at predetermined intervals according to the type of the unit cells 110.

In this embodiment, the porous tube 140 is disposed on both sides of the first unit cell 110, that is, the center unit cell. The folding separator sheet 120 in which the unit cells 110 are located is directly passed through the roll laminator and adhered on the folding separator sheet 120 so that the center unit cell 110 and the porous tube 140 are connected to the folding separator sheet (120). Each of the unit cells 110 is folded and rolled out from the first unit cell 110 bonded to the outer side where adjacent unit cells are located. After the tape is wound around the tape 130, the tape 130 is fixedly attached or thermally fused.

The subsequent battery manufacturing process is as follows. The positive electrode and the negative electrode lead are welded to the electrode tab (T) portion of the stack-folding type electrode assembly 100 manufactured. At this time, it is effective to use aluminum as the positive electrode and copper as the negative electrode. After the packing of the welded cells into an aluminum pouch, an electrolyte is injected.

The electrolytic solution used in the art is not particularly limited. Specific examples of the solvent include dimethyl carbonate (DMC), ethylene carbonate (EC), ethyl methyl carbonate (EC), propylene carbonate (PC), diethyl carbonate (EC), ethylene carbonate (EC), dimethyl carbonate (DMA) At least one selected from the group consisting of N, N-dimethylformamide (DMF), N-methyl-2-pyrrolidinone (NMP), dimethyl sulfoxide (DMSO), tetrahydrofuran (THF), propylene carbonate use.

At this time, since the electrolyte is injected through the open end of the porous tube 140 and dispersed in the four directions through the fine holes 142 of the porous tube 140, the electrolyte impregnation process can be performed more quickly than in the prior art.

8 is a view for explaining a method of manufacturing a stack-folding type electrode assembly according to another embodiment of the present invention. This method can be regarded as a method of manufacturing an electrode assembly as shown in Fig.

Here, the porous tube 140 is disposed on each side of the unit cell 110. Each of the unit cells 110 and the porous tube 140 are folded and folded out from the first unit cell 110 to the outside where the adjacent unit cells are located.

9 is a perspective view of a stack-folding type electrode assembly according to another embodiment of the present invention.

After the folding of the folding separator sheet 120 is completed, through-holes 150 are formed on both sides of the folding separator sheet 120 on the basis of the protruding direction of the electrode tabs T, ) Is formed.

The size of the through hole 150 is not particularly limited. However, if the through hole 150 is formed too large, the function of the folding separator sheet 120 may be degraded or the folding separator sheet 120 may be damaged. If the size of the through hole 150 is too small, it is difficult to sufficiently improve the impregnating property of the electrolyte solution and the easy discharge of the gas, which are expected in the present invention. Therefore, the size of the through hole 150 may be adjusted to a proper size by a person skilled in the art in order to achieve the above purpose. More specifically, the through hole 150 may be formed to have a size of 0.1 to 2 mm according to a preferred embodiment of the present invention. have.

It is preferable that the positions where the through holes 150 are formed on the folding sheet 120 are parallel to the porous tubes 140 on both sides of the folding sheet 120.

The number of the through holes 150 is not particularly limited, and the number of the through holes 150 may be varied depending on the usage and size of the secondary battery. In this case, the number of the through holes 150 is related to the size of the through holes 150. When the size of the through holes 150 is small, a large number of through holes 150 can be formed from the center of the electrode assembly, When the size of the through hole 150 is relatively large, the number of the through holes 150 formed can be reduced to adjust the gas discharge amount, speed, and direction.

On the other hand, the shape of the through hole 150 is formed in a circular or elliptic curved shape which does not support the angle. In the case where the through hole 150 is not formed in such a curved shape and is formed in a mock-up or angled shape, stress may concentrate on the angled portion, thereby causing the folding separator sheet 120 to be easily damaged or functioning It can be degraded.

The through hole 150 may be formed by partially punching a corresponding portion of the folding and separating sheet 120 with a needle having a predetermined diameter without forming a through hole 150, have. The through hole (150) together with the porous tube (140) constitutes a path for electrolyte impregnation and gas discharge.

10 is a cross-sectional view of a stack-folding type electrode assembly according to another embodiment of the present invention. The folding separator sheet 120 is formed with a hole H at a position corresponding to the side surface of the unit cell 110. In order to manufacture such a stack-folding type electrode assembly, as shown in FIG. 11, a hole H is formed at a position corresponding to a side surface of the unit cell 110 in the folding separator sheet 120 before folding. The holes H are regularly punctured between the unit cells 110 by using a press cutting machine. The size of the hole (H) can be specifically set to be 10 to 30 mm in length, 0.5 to 2 mm in width, and 20 mm in the interval between holes (H). Within this range, have.

The hole H may be folded while being in parallel with the porous tube 140 so that the hole H and the porous tube 140 are communicated with each other. Since the hole H is located between the unit cells 110, the problem of shorting between the unit cells 110 does not occur and the effect of wetting and venting can be obtained.

As described above, the stack-folding type electrode assembly according to the present invention is formed by the porous pipe 140, the porous pipe 140, the through hole 150, the porous pipe 140 and the hole H, The electrolyte injected in the last step reaches the inner unit cell and can be completely wetted and the impregnation speed is also increased. A special process such as an additional process such as aging in which the negative electrode is sufficiently wetted with the electrolyte after storing the electrolyte for a certain period of time, a vacuum or a pressure is not required after the electrolyte injection, and the battery manufacturing time can be shortened.

The stack-folding type electrode assembly according to the present invention is a stack-folding type electrode assembly in which a porous pipe 140, a porous pipe 140, a through hole 150, a porous pipe 140 and a hole H are filled with an electrolytic solution Is vaporized or gas is generated inside the electrode assembly, the vaporized electrolytic solution or gas can be easily discharged to the outside. Therefore, the swelling phenomenon of the battery is relatively reduced and the possibility of occurrence of ignition or explosion of the battery can be reduced, so that the safety of the secondary battery can be greatly improved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but many variations and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims. It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the appended claims.

110 ... unit cell 120 ... folding separator sheet
130 ... adhesive tape 140 ... porous tube
150 ... Through hole H ... Hole

Claims (13)

delete delete delete delete delete delete delete delete A plurality of stacked unit cells are overlapped with each other and a continuous folding separator sheet is interposed in each of the overlapping portions, wherein the folded separator sheet wrapped by the stacked unit cells and the side faces of the unit cells have a porous A method of manufacturing a stack-folding type electrode assembly, comprising the steps of:
Placing a central unit cell at a first end of the folding separator sheet and successively positioning the unit cells at a predetermined interval in the same electrode alignment manner, and arranging a porous tube at a side of the unit cell; And
Folding the center unit cell and the porous tube once with the folding separator sheet having a long length and then folding the folding separator sheet to the outside where adjacent unit cells are located and folding each unit cell by folding Wherein the stacked electrode assembly is a stacked electrode assembly. The method of claim 9, further comprising forming a through hole on both sides of the folding separator sheet based on a direction in which the electrode tab protrudes after folding of the folding separator sheet is completed. A method of manufacturing a folding type electrode assembly. 11. The method of claim 10, wherein the through hole is formed by partially punching a corresponding portion of the folding separator sheet with a needle having a predetermined diameter. The stack-folding type electrode assembly of claim 9, wherein the folding separator sheet is formed with a hole at a position corresponding to a side surface of the unit cell. 10. The method of claim 9, wherein the porous tube is compressed during folding.

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