KR101075879B1 - Process for Preparing Cylindrical Battery to Prevent Deformation of Beading Portion - Google Patents

Abstract

The present invention is a method for manufacturing a secondary battery consisting of inserting a jelly-roll in a cylindrical can, forming a beading portion, injecting an electrolyte solution, mounting a cap assembly, and then sealing the battery can by crimping. In order to secure the internal space of the battery cell, a step of pressing the upper surface of the battery ('sizing process') is a process of forming the beading portion without supporting the lower surface of the beading portion and causing its downward deformation ('beading' The process of the present invention provides a method of manufacturing a cylindrical battery, characterized in that it is carried out simultaneously with or in the beading process.

The manufacturing method according to the present invention can minimize the loss of the internal space by preventing the bead portion is deformed downward by the pressure applied during the sizing process, so that the battery capacity can be relatively increased, and jelly-roll by the downward deformation of the bead portion This can prevent the internal short circuit that may occur while being pressed can improve the safety of the battery.

Description

Process for Preparing Cylindrical Battery to Prevent Deformation of Beading Portion

The present invention relates to a method for manufacturing a cylindrical battery for preventing deformation of the beading portion, and more particularly, to insert a jelly-roll in the cylindrical can, form the beading portion, inject the electrolyte, mount the cap assembly, and then crimp it. In the method of manufacturing a secondary battery configured to seal the battery can, the step of pressing the upper surface of the battery ('sizing step') in order to secure a large battery cell internal space compared to the same standard, the lower end of the bead portion It relates to a cylindrical battery which is configured to be carried out simultaneously with or in succession to the step of forming the beading portion ('beading process') without supporting the face and causing its downward deformation.

As the development and demand for mobile devices increases, the demand for secondary batteries as energy sources is increasing rapidly. Among them, many researches have been conducted and commercialized on lithium secondary batteries with high energy density and high discharge voltage. It is widely used.

According to the shape of the battery case, secondary batteries are classified into cylindrical batteries and rectangular batteries in which the electrode assembly is embedded in a cylindrical or rectangular metal can, and pouch-type batteries in which the electrode assembly is embedded in a pouch type case of an aluminum laminate sheet. .

In addition, the electrode assembly embedded in the battery case is a power generator capable of charging and discharging composed of a laminated structure of the anode / separator / cathode, a jelly-roll type wound through a separator between the long sheet-type anode and cathode coated with the active material And a plurality of positive and negative electrodes of a predetermined size are classified into a stack type in which a plurality of positive and negative electrodes are sequentially stacked in a state where a separator is interposed therebetween. Among them, the jelly-roll type electrode assembly has an advantage of being easy to manufacture and having a high energy density per weight.

1 illustrates a structure of a conventional cylindrical secondary battery as a vertical sectional view.

Referring to FIG. 1, a cylindrical secondary battery 10 generally includes a cylindrical can 20, a jelly-roll electrode assembly 30 accommodated in the can 20, and a cap coupled to an upper portion of the can 20. The assembly 40, the bead 21 for mounting the cap assembly 40, and the crimping portion 50 for sealing the battery.

The electrode assembly 30 has a structure that is wound in a jelly-roll shape with a separator 33 interposed between the positive electrode 31 and the negative electrode 32, and the positive electrode tab 34 is attached to the positive electrode 31. A negative electrode tab (not shown) is attached to the negative electrode 32, and is connected to the lower end of the can 20.

The cap assembly 40 includes an upper cap 41 for forming a positive electrode terminal, a positive temperature coefficient element 42 for blocking current due to a large increase in battery resistance when the temperature inside the battery increases, and a pressure increase inside the battery. Safety vents 43 for interrupting current and / or exhausting gas, insulating members 44 for electrically separating the safety vents 43 from the cap plate 45, except for certain parts, and connected to the anode 31. The cap plate 45 to which the positive electrode tab 34 is connected is laminated in this order. The cap assembly 40 is mounted on the beading portion 21 formed inwardly by beading the upper end of the can 20 while being mounted on the gasket 60.

In the cylindrical secondary battery, a jelly-roll type electrode assembly is generally inserted into a cylindrical can, a bead portion is formed in a can corresponding to the upper outer circumferential surface of the jelly-roll, and then a cap assembly equipped with a gasket is installed. Prepared by crimping and sizing.

The sizing process is a process of pressing the battery into a mold in a sealed state of the injection hole in order to reduce the width of the beading portion to secure the internal space. 2 and 3 disclose schematic views showing the shape of the bead portion before and after the sizing process. Referring to these figures, the width L of the beading portion (see FIG. 2) before the sizing process decreases as L '(see FIG. 3) by the sizing process, but also causes a problem that the inner side of the beading portion is deformed downward. Due to the downward deformation of the bead portion, the internal space of the battery is reduced, and thus the battery capacity may be reduced compared to the same standard. In addition, when the downwardly deformed bead portion comes into contact with the top surface of the electrode assembly or the electrode tab, a short circuit may be caused, thereby seriously affecting the safety of the battery. On the other hand, since the sizing process proceeds at a fast descending speed in order to prevent the width of the bead part from being restored again, strong impact may cause damage to the electrode assembly.

As a technique for preventing the deformation of the bead portion, for example, Korean Patent Application Publication No. 1998-037981 is a first step of rotating the case at a predetermined speed, a tool for forming a bead portion on the outer peripheral surface of the rotating case The present invention discloses a method of manufacturing a battery case comprising a second step of pressurizing at a predetermined speed so that the bead part is formed by stretching, and a third step of pressing the case in which the bead part is formed in the longitudinal direction. Accordingly, in order to prevent the bead portion from deforming downward when pressing the bead portion, a technique of forming the thickness of the upper portion of the bead portion is smaller than the thickness of the lower portion.

However, even in this case, since the downward deformation of the bead portion cannot be fundamentally prevented, the reliability is low. Even if the downward deformation is prevented, the upper portion of the bead portion is not formed horizontally, so that the upper cap assembly cannot be stably mounted. There is. In addition, it is not easy to adjust the thickness of the bead portion, there is a limit in practical use, and due to the friction generated by contact between the mold and the beading knife in the formation of the bead portion, the mechanical strength of the relatively thin upper portion of the bead portion is weak and easily. Since it may be damaged, there is a problem in the safety of the battery. On the other hand, the pressurization in the above technique is only carried out in the general beading process and does not mean a sizing process.

Japanese Patent Application Laid-Open No. 1999-277153 discloses a method of manufacturing a cylindrical member constituting a positive electrode container in a sodium sulfur battery, and discloses a technique of performing a beading process while applying pressure in the upper and lower parts. This is to prevent the problem that the thickness of the bead portion is reduced by the beading process, thereby reducing the corrosion resistance and durability, and failing to exhibit a sufficient spring effect, and that the member is stretched and formed to press the upper and lower portions of the member to form the bead portion. Since it is a technique for reducing, it can be applied only when forming the beading portion in the inner surface of the cylindrical member is empty.

Therefore, there is a high need for a technique capable of preventing deformation of the bead portion in an easy manner.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-described problems of the prior art and the technical problems required from the past.

The inventors of the present application, after in-depth study and various experiments, support the bottom surface of the beading part during the sizing process, and simultaneously or continuously perform the beading process when preventing the downward deformation of the beading part to prevent unnecessary battery internal space. The inventors have found that wasteful waste can be prevented and the safety of the battery can be improved, and the present invention has been completed.

The method for manufacturing a cylindrical battery according to the present invention is a method for manufacturing a secondary battery comprising inserting a jelly-roll in a cylindrical can, forming a beading portion, injecting electrolyte, mounting a cap assembly, and then crimping to seal the battery can. In order to secure a large battery cell internal space compared to the same standard, the step of pressing the upper surface of the battery ('sizing process'), while supporting the lower surface of the beading portion without causing its downward deformation, It is comprised simultaneously with the process of forming a bead part ('beading process'), or continuing to the said beading process.

The manufacturing method according to the present invention may be specifically configured to include the following steps i) to vi).

i) inserting a jelly-roll into the cylindrical can;

ii) a beading step of forming a beading part on an upper end of the can;

iii) a sizing process performed simultaneously with or subsequent to the beading process, the width of the beading portion being reduced;

iv) an electrolyte injection process for injecting an electrolyte solution;

v) a cap assembly process for mounting the cap assembly on top of the beading portion; And

vi) A crimping process for sealing the inside of the can by crimping the top of the can.

That is, unlike the prior art method of performing the sizing process by pressing the top surface of the battery after the crimping process, the sizing process is performed simultaneously or continuously with the beading process, so that the width of the beading portion can be controlled relatively precisely. Therefore, the outer diameter and the height of the battery can be adjusted according to the desired degree.

Moreover, since the sizing process is performed while supporting the bottom surface of the beading portion, the downward deformation of the beading portion due to the pressure applied during the sizing process is prevented, and as a result, the internal space increases as much as the downward deformation of the beading portion is prevented. Battery capacity can be increased for the same specification. In addition, since the downwardly deformed portion of the bead portion can be prevented from contacting the top surface of the jelly-roll, the electrode tab, and the like, the safety is excellent.

In the present invention, the beading portion is formed to prevent the flow of the jelly-roll located below and to mount the cap assembly, it has a structure indented in the inner direction of the cylindrical can. Therefore, the downwardly deforming the beading portion means that the indented portion is deformed while bending in the jelly-roll direction.

The beading process and the sizing process may be preferably performed by an upper spindle which is mounted on the top of the can and rotates, and a bead supporting jig which is capable of vertically moving inside the upper spindle.

In the present invention, the bead support jig, for example, may have a structure that can be moved up and down inside the upper spindle (for example, the central hollow portion). The bead supporting jig having a structure capable of vertically moving in the central hollow of the upper spindle may be, for example, a cylindrical structure in which a hollow is formed at the center such as the upper spindle so that the electrode tab may protrude.

In some cases, the bead supporting jig may be formed integrally with the upper spindle, or may be a structure that is raised and lowered together with the upper spindle for the efficiency of the process. All such modifications should be construed as falling within the scope of the present invention.

In addition, the bead support jig may have a variable bottom support structure for supporting the bottom surface of the bead portion to prevent the downward deformation of the bead portion.

As an example of such a structure, the bead supporting jig has the bottom support part extended in a horizontal direction like an umbrella to support the bottom surface of the bead part by using a centrifugal force generated while the upper spindle rotates during the beading process. When the rotation of the upper spindle is stopped after the pressure is applied to the sizing process, that is, when the centrifugal force is removed, the lower support may be operated in a so-called blade manner to return to the original position.

Even when the sizing process proceeds at a fast descending speed by such a lower supporter, the lower surface of the beaded part can be supported to prevent its downward deformation. In addition, when the lower support portion of the jig for supporting the beading portion is positioned at the portion where the beading portion is to be formed during the beading process, it may serve as a guide of the beading process, thereby helping to form a uniform beading portion.

The lower support portion may be formed perpendicular to the longitudinal direction of the battery in parallel to the lower surface of the beading portion to prevent the downward deformation of the lower surface of the beading portion. In addition, the thickness of the lower support portion is not particularly limited as long as it can be inserted between the lower surface of the bead portion and the upper surface of the jelly-roll or the insulating member located at the upper end thereof, and may be preferably about 0.1 to 0.5 mm. That is, when the thickness of the lower end support portion is too thick, it may cause unnecessary space waste, and insertion into the bead bottom end surface forming position may not be easy. On the contrary, when the thickness is too thin, it is not preferable because it may be difficult to provide a mechanical stiffness that can prevent the downward deformation of the bead portion in the sizing process.

The variable structure of the lower support part is not particularly limited as long as it is capable of expanding and contracting in the horizontal direction so as to support the lower surface of the beading part. For example, a disk-shaped lower end support formed on the lower part of the bead supporting jig. Since the additional hollow portion is coupled to the spring mounted inside, the bottom support portion may be folded and unfolded by contracting or expanding the spring according to the vertical movement position of the bead supporting jig. In addition, as described above, a structure in which the lower support portion is unfolded in a blade manner by the rotational force of the jig, or a structure in which the bead supporting jig is folded while being introduced into the central hollow portion of the upper spindle may be possible.

On the other hand, the upper spindle serves to rotate the cylindrical battery together with the lower spindle in a fixed state of the top of the cylindrical battery, the hollow portion is formed in the center is configured to protrude to the electrode tab protruding from the jelly-roll Can be. The upper spindle may consist of a single member, or may consist of a first member inserted into the inner surface of the cylindrical can and a second member pressing on the outer surface. On the other hand, the bottom of the can is rotated after being stably fixed by the lower spindle.

Referring to the beading process and the sizing process performed by the bead support jig illustratively,

The battery can is fixed by an upper spindle and a lower spindle having a bead supporting jig therein,

As the upper and lower spindles rotate, the bead supporting jigs in the upper spindles unfold, the beading knife advances to form the beading portion,

While the beading knife reverses while maintaining the upper and lower spindles rotating, while the beading part supporting jig supports the lowering part of the beading portion, the upper spindle is further lowered to press the beading portion, thereby sizing.

After the sizing is completed, the bead supporting jig is restored to its original state as the upper and lower spindles stop rotating, the upper spindle is raised and the lower spindle is lowered.

More specifically, the bead supporting jig descends to the open top of the cylindrical can together with the upper spindle, so that the can is stably fixed by the upper spindle and the lower spindle. Then, as the upper and lower spindles rotate, the variable bottom support of the bead support jig unfolds and is inserted between the bottom face of the bead and the jelly-roll to consequently support the bottom face of the bead.

As described above, in the state where the battery can is pressed by the upper and lower spindles, the beading knife is advanced in the can direction to press the outer surface of the battery can to form a bead in the inwardly inward shape of the can. Therefore, the bead supporting jig may help to form a uniform bead by guiding the beading knife during the beading process.

After the beading portion is formed, a sizing process is performed to appropriately reduce the width of the beading portion as desired by lowering the upper spindle to further press the beading end surface. In the sizing process, even when the lower support portion of the bead supporting jig stably supports the beading portion, the downward deformation of the beading portion may be prevented even when the upper spindle presses the beading portion at a high descending speed.

The width of the bead may be appropriately adjusted in consideration of the height of the desired battery, the shape of the bead, the interference with the cap assembly component, the ease of the process, and the width of the bead before the sizing process may be preferably 1 to 1.5 mm. And, the width of the pressed bead portion after the sizing process may be 0.1 to 0.5 mm.

After performing this sizing process, the upper and lower spindles stop rotating and are varied so that the lower support portion of the bead supporting jig can be removed from the lower surface of the beading portion and ascends with the upper spindle, and the lower spindle is lowered.

The material of the cylindrical can is not particularly limited, and preferably, may be formed of any one of stainless steel, steel, aluminum, or an equivalent thereof.

The present invention also provides a cylindrical secondary battery produced by the above method. The battery may preferably be a lithium secondary battery using a lithium salt-containing electrolyte having high energy density, discharge voltage, and output safety.

The secondary battery according to the present invention is prevented by the deformation of the beading portion by the sizing process, it may be preferably a structure in which the width of the beading portion is 0.1 ~ 0.5 mm and its bottom surface is maintained in a horizontal state. Such a secondary battery may have a relatively high battery capacity as compared to the conventional secondary battery, since its internal content increases as the downward deformation of the bead portion is prevented.

Other components of the lithium secondary battery according to the present invention will be briefly described below.

In general, a lithium secondary battery is composed of a positive electrode, a negative electrode, a separator, a lithium salt-containing nonaqueous electrolyte, and the like.

The positive electrode is produced by, for example, applying a mixture of a positive electrode active material, a conductive material, and a binder onto a positive electrode current collector, followed by drying, and further, a filler may be further added as necessary. The negative electrode is also manufactured by applying and drying a negative electrode material on the negative electrode current collector, and if necessary, the components as described above may be further included.

The separator is interposed between the cathode and the anode, and an insulating thin film having high ion permeability and mechanical strength is used.

The lithium salt-containing non-aqueous electrolyte solution consists of a nonaqueous electrolyte solution and a lithium salt, and a liquid nonaqueous electrolyte solution, a solid electrolyte, an inorganic solid electrolyte, and the like are used as the nonaqueous electrolyte solution.

Since the current collector, the electrode active material, the conductive material, the binder, the filler, the separator, the electrolyte, the lithium salt, and the like are known in the art, a detailed description thereof will be omitted herein.

The lithium secondary battery according to the present invention can be produced by conventional methods known in the art. That is, it may be prepared by inserting a porous separator between the anode and the cathode and injecting the electrolyte therein.

The positive electrode may be manufactured by, for example, applying a slurry containing the lithium transition metal oxide active material, the conductive material, and the binder described above onto a current collector, followed by drying. Similarly, the negative electrode can be produced by, for example, applying a slurry containing the carbon active material, the conductive material, and the binder described above onto a thin current collector and then drying.

The present invention is also used as a jig used in the manufacturing process of the cylindrical secondary battery, mounted on the top of the can is mounted in a form capable of vertical movement in the central hollow portion of the upper spindle to rotate, to support the bottom surface of the beading portion when moving downwards By including a lower support that is variable so that it is variable so that it can be removed from the bottom surface of the bead portion when moving upwards, to provide a bead support jig, characterized in that for supporting the bottom surface of the bead portion during the sizing process.

When the secondary battery is manufactured using the bead support jig, the bottom surface of the bead part is stably supported, thereby preventing the bead part from deforming downward due to the pressure applied during the sizing process. The performance degradation can be prevented.

Hereinafter, the present invention will be further described with reference to the drawings, but the scope of the present invention is not limited thereto.

4 and 5 schematically show a manufacturing process of the cylindrical secondary battery according to one embodiment of the present invention.

Referring to these drawings, first, the jelly-roll 110 is inserted into the housing of the cylindrical can 200, and the negative electrode tab 130 attached to the cathode of the jelly-roll 110 is attached to the bottom of the can 200. Connect. Then, the insulating member 140 is mounted on the upper end of the jelly-roll 110. Meanwhile, the positive electrode tab 120 is attached to the positive electrode of the jelly roll 110, and the insulating tape 121 is partially attached to the positive electrode tab 120, and the center of the jelly roll 110 is attached to the positive electrode tab 120. It protrudes to the open top of the can 200 through the formed hollow portion 150. The positive electrode tab 120 may protrude from the insulating member 140, and an opening is formed to allow gas generated inside the battery to be discharged to the outside through the hollow part 150.

Then, the beading process and the sizing process are performed. The apparatus for this purpose includes an upper spindle 710 for fixing the inner side of the open top of the battery and an outer surface of the can, a bead supporting jig 720 positioned inside the upper spindle 710, and a lower spindle for fixing the lower end of the battery. 730, and a beading knife 740 for flowing from the side of the battery to form the beading portion.

The upper spindle 710 descends to an open upper end of the battery together with the bead supporting jig 720 to fix the upper inner and outer surfaces of the can 200. In addition, the lower spindle 730 is raised to fix the bottom outer surface of the can.

The upper spindle 710 and the lower spindle 730 rotate, at which time the variable lower support 721 of the bead support jig 720 is unfolded like an umbrella and is positioned on the bottom surface of the position where the bead is to be formed. Done. At the same time, the beading knife 740 moves forward from the upper side of the can 200 to form the beading portion 210 having the structure indented inward and then moves backward.

Then, as shown in Figure 5, while the upper spindle 710 is further lowered by pressing the upper surface of the beading portion 210 to perform a sizing process to reduce the width of the beading portion (210). At this time, the bottom surface of the beading portion 210 is supported by the variable bottom supporting portion 721 of the beading portion supporting jig 720 is compressed without being deformed downward substantially perpendicular to the longitudinal direction of the battery. After performing the sizing process, the upper spindle 710 and the lower spindle 730 stop the rotation, so that the lower support 721 of the bead support jig 720 returns to its original position and the The upper spindle 710 and the bead supporting jig 720 are raised and the lower spindle 730 is lowered to complete the bidding process and the sizing process.

Therefore, downward deformation of the beading unit 210 is prevented, thereby preventing battery waste of internal space, thereby increasing battery capacity, and preventing battery from risk of internal short circuit due to downward deformation of the compressed beading unit 210. Can improve.

In addition, it is possible to precisely control the width of the bead portion by performing a sizing process simultaneously or continuously with the beading process. In addition, even when the sizing process is performed at a high descending speed, downward deformation of the beading part 210 may be prevented by the variable lower support part 721 of the beading part supporting jig 720.

6 and 7 schematically show one exemplary bead support jig that can be used in the manufacturing process of the battery according to FIG. 4.

First, referring to FIG. 6, which shows a state in which the bottom support of the bead support jig is unfolded during the sizing process, the bead support jig 720 has a cylindrical hollow similar to the shape of the upper spindle (refer to FIG. 4; 710). Because of the structure, the positive electrode tab (see FIG. 4; 120) of the battery may protrude through the hollow portion and move upward and downward with the upper spindle. A lower support portion 721 is formed at the lower end of the bead supporting jig 720 to prevent downward deformation of the bead by placing it on the lower surface of the bead and supporting it.

The lower support part 721 is formed substantially perpendicular to the longitudinal direction of the beading part supporting jig 720, and its width W is formed to be substantially the same as the width of the lower surface of the beading part. Even when pressure is applied to the top, the bottom surface of the bead portion is supported so that it can be formed parallel to the top surface of the jelly-roll without downward. After the bead supporting jig 720 is lowered to the open top of the battery case (can) together with the upper spindle, the lower support 721 is expanded while being rotated together with the upper spindle to be inserted at a position to form the bead.

In addition, referring to FIG. 7 illustrating a state in which the lower support portion 721 of the beading support jig is folded after the sizing process, the lower support portion 721 is folded when the rotation is stopped after completing the sizing process. Thus, the bead supporting jig then rises together when the upper spindle rises. Such a variable deformation of the lower support 721 is achieved, for example, by contraction and expansion of a spring (not shown) coupled with the lower support 721 inside the hollow of the bead support jig 720. May be

8 and 9 are schematic views of the bead support jig according to another embodiment of the present invention. However, except for the shape of the bottom support of the bead support jig is the same as Figures 6 and 7 and other components will not be described separately.

Referring to these drawings, the lower support portion 722 has a structure in which a plurality of members are continuously formed, and these members are unfolded by the rotational force when the bead supporting jig 720 rotates in one direction. In addition, the rotation of the bead support jig 720 with the upper spindle is folded back to its original state.

Although described above with reference to the drawings according to an embodiment of the present invention, those of ordinary skill in the art will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

As described above, the battery manufacturing method according to the present invention performs a sizing process simultaneously or continuously with the forming process of the beading portion, and stably supports the bottom surface of the beading portion in such a sizing process, thereby reducing the downward deformation of the beading portion. By preventing the waste of internal space of the battery, it is possible to relatively increase the battery capacity, and to improve the safety of the battery by blocking the risk of internal short circuit caused by the downwardly deformed beading portion, precisely width of the beading portion Can be controlled.

1 is a schematic cross-sectional view showing a representative superstructure of a cylindrical battery of the prior art;

Figure 2 is an enlarged schematic diagram of the bead portion before performing the sizing process in the process of manufacturing a cylindrical battery by the method of the prior art;

3 is an enlarged schematic view of the bead portion deformed downward after the sizing process in the process of manufacturing the cylindrical battery by the method of the prior art;

4 and 5 are schematic diagrams of a series of processes for manufacturing a cylindrical battery by the method according to one embodiment of the present invention;

6 and 7 are schematic views of the bead support jig used in Figure 4, Figure 6 shows a state in which the lower support of the bead support jig unfolded, Figure 7 is folded bottom support of the bead support jig Indicates status;

8 and 9 is a schematic view of the bead support jig according to another embodiment of the present invention, Figure 8 shows a state in which the lower support portion of the bead support jig unfolded, Figure 9 shows the bead support jig The lower support portion is in a folded state.

Claims (7)

In the manufacturing method of a secondary battery consisting of inserting a jelly-roll in a cylindrical can, forming a beading portion, injecting an electrolyte solution, mounting a cap assembly, and then sealing the battery can by crimping, inside a wide battery cell compared to the same standard. In order to secure the space, a step of pressing the top surface of the battery ('sizing process') is a step of forming a beading portion without supporting the bottom surface of the beading portion and causing its downward deformation ('beading process' ) Or simultaneously with or subsequent to the beading process. According to claim 1, The beading process and the sizing process is performed by the upper spindle is mounted on the top of the can rotates, and the bead portion support jig capable of vertically moving inside the upper spindle, the bead portion support The jig has a structure comprising a variable bottom support that can support the bottom surface of the beading portion during the sizing process. The jig for supporting the beading part of claim 2, wherein the jig for supporting the beading part includes a variable lower support part having a structure capable of supporting the bottom surface of the beading part by being unfolded by the rotational force generated by the rotation of the upper spindle. The manufacturing method characterized in that to restore the original state while folding by stopping the rotation. The method of claim 1, wherein the beading process and the sizing process, The battery can is fixed by an upper spindle and a lower spindle including a bead supporting jig, As the upper and lower spindles rotate, the bead supporting jig in the upper spindle is unfolded by the rotational force, the beading knife moves forward to form the beading portion, While the beading knife is retracted while maintaining the upper and lower spindles rotate, the beading unit supporting jig supports the lowering surface of the beading part, while the upper spindle is lowered to press the beading part and sizing. After stopping the rotation of the upper and lower spindles after the sizing is completed, the bead support jig is restored to its original state, the upper spindle is raised and the lower spindle is lowered. Jig used in the manufacturing process of the cylindrical battery, mounted on the top of the can in the form of a vertical movement is possible to move inside the upper spindle, it is located on the bottom surface of the beading portion in the downward movement to support it, the bottom of the beading portion A jig for beading part support, characterized by supporting a bottom surface of the beading part during a sizing process by including a variable lower supporter moving upward after being removed from the surface. Cylindrical secondary battery produced by the method according to any one of claims 1 to 4. 7. The cylindrical secondary battery according to claim 6, wherein a width of the bead portion of the secondary battery is 0.1 to 0.5 mm and its bottom surface is maintained in a horizontal state.

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