KR20220148098A - Secondary battery and method for manufacturing the same - Google Patents

Abstract

A secondary battery of the present invention comprises: an electrode assembly in which a laminated sheet having a negative electrode structure including a positive electrode having a positive electrode tab, a separator, and a negative electrode tab is wound in a jelly-roll form and a core portion is formed in the center; a can into which the electrode assembly is inserted and to which the negative electrode tab is connected; a cap assembly which is coupled to the opening of the can and to which the positive electrode tab is connected; and a reinforcing member provided at an end of the separator exposed externally from the positive electrode or the negative electrode and preventing the heat of the positive electrode tab or the negative electrode tab from being transferred to the separator. Accordingly, shrinkage of the separator can be prevented and as a result, short circuit or ignition can be prevented.

Description

Secondary battery and manufacturing method thereof

The present invention relates to a secondary battery and a method for manufacturing the same, and more particularly, to a secondary battery capable of preventing heat from a positive electrode tab or a negative electrode tab from being transferred to a separator, and a method for manufacturing the same.

In general, a secondary battery refers to a battery that can be charged and discharged, unlike a primary battery that cannot be charged. Such secondary batteries are widely used in high-tech electronic devices such as phones, notebook computers, and camcorders.

The secondary battery is classified into a can-type secondary battery in which the electrode assembly is embedded in a metal can, and a pouch-type secondary battery in which the electrode assembly is embedded in a pouch. The can-type secondary battery includes an electrode assembly, an electrolyte, a can for accommodating the electrode assembly and the electrolyte, and a cap assembly mounted in an opening of the can. And the pouch-type secondary battery includes an electrode assembly, an electrolyte, and a pouch accommodating the electrode assembly and the electrolyte.

On the other hand, the electrode assembly of the can-type secondary battery has a structure in which electrodes and separators are alternately stacked and wound in a jelly-roll form. The electrode includes a positive electrode and a negative electrode, and the positive electrode includes a positive electrode tab, and the negative electrode includes a negative electrode tab. In addition, the positive electrode tab is connected to the cap assembly, and the negative electrode tab is connected to the can.

However, in a can-type secondary battery having the above structure, high heat is generated in the positive electrode tab and the negative electrode tab when an external short circuit occurs, and as the high heat of the positive electrode tab and the negative electrode tab is transferred to the separator, the separator contracts, and as a result, the positive electrode and the negative electrode respond to each other There was a problem in that a short circuit or fire occurred.

In particular, since the separator is tightly wound in the core part of the electrode assembly close to the positive electrode tab, the separator is severely contracted, and as a result, there is a problem in that a short circuit or a high possibility of ignition occurs.

Patent Publication No. 10-2007-0108761.

An object of the present invention is to prevent heat from the positive electrode tab or the negative electrode tab from being transferred to the separator even when high heat is generated in the positive electrode tab and the negative electrode tab, thereby preventing the separator from shrinking, and as a result, short circuit or ignition may occur. An object of the present invention is to provide a secondary battery capable of preventing the occurrence and a method for manufacturing the same.

The secondary battery of the present invention includes: an electrode assembly in which a laminated sheet having a positive electrode having a positive electrode tab, a separator, and a negative electrode having a negative electrode tab is wound in a jelly-roll form, and a core part is formed in the center; a can into which the electrode assembly is inserted and to which the negative electrode tab is connected; a cap assembly coupled to the opening of the can and to which the positive electrode tab is connected; and a reinforcing member provided at an end of the separator exposed to the outside from the positive electrode or the negative electrode and preventing heat of the positive electrode tab or the negative electrode tab from being transferred to the separator.

The reinforcing member may include a first reinforcing layer provided only on one surface of the separation membrane located in the core portion.

The reinforcing member may further include a second reinforcing layer provided only at an end of the separator positioned within a set range with respect to the positive electrode tab or the negative electrode tab.

The reinforcing member may be made of a material having insulation and heat insulating properties.

The second reinforcing layers respectively coated on the surfaces of the separators corresponding to each other may be provided so as not to contact each other in order to prevent heat transfer.

On the other hand, in the secondary battery manufacturing method of the present invention, (a) a laminated sheet having a positive electrode having a positive electrode tab, a separator, and a negative electrode having a negative electrode tab is wound in a jelly-roll form, and a core portion is formed in the center. manufacturing an electrode assembly; (b) inserting the electrode assembly into the can, and then connecting the negative electrode tab included in the electrode assembly to the can; (c) coating an end of the separator exposed to the outside from the positive electrode or the negative electrode with a reinforcing member to prevent heat from the positive electrode tab or the negative electrode tab from being transferred to the separator; and (d) connecting the positive electrode tab of the electrode assembly to the cap assembly, and then coupling the cap assembly to the opening of the can to manufacture a secondary battery.

In the step (c), the reinforcing member may include a first reinforcing layer formed while being coated on only one surface of the separator located in the core portion.

In step (c), the reinforcing member may further include a second reinforcing layer coated only on the end of the separator positioned within a set range with respect to the positive electrode tab or the negative electrode tab.

In the step (c), the reinforcing member may be made of a material having insulation and heat insulating properties.

The step (c) may further include a protective layer coating process for protecting the reinforcing member while being coated on the outside of the reinforcing member.

The protective layer may be coated to surround the entire reinforcing member.

The second reinforcing layers respectively coated on the surfaces of the separators corresponding to each other in step (c) may be coated so as not to contact each other to prevent heat transfer.

In the step (c), before coating the second reinforcing layer, attaching a protective film to the positive electrode tab to prevent the second reinforcing layer from being coated on the positive electrode tab, and attaching to the positive electrode tab when the coating of the second reinforcing layer is completed It may further include a process of removing the old protective film.

In the step (c), when the first reinforcing layer is coated, the first reinforcing layer may be coated on one surface of the separator located in the core part in a state in which the can is vertically erected and then the can is rotated left and right.

The setting range may be a rotation radius of 2 mm to 10 mm based on the positive electrode tab or the negative electrode tab.

The secondary battery of the present invention includes a reinforcing member that prevents the heat of the positive electrode tab or the negative electrode tab from being transferred to the separator, thereby preventing the separator located in the core part of the electrode assembly and the separator adjacent to the positive electrode tab or the negative electrode tab from shrinking. and, as a result, safety can be improved.

1 is a perspective view illustrating a secondary battery according to a first embodiment of the present invention;
2 is a cross-sectional view illustrating a secondary battery according to a first embodiment of the present invention.
3 is an enlarged view of part 'A' shown in FIG.
4 is a partial plan view illustrating an electrode assembly in which a positive electrode tab of a secondary battery according to a first embodiment of the present invention is located;
5 is an enlarged view of part 'B' shown in FIG.
6 is a partial bottom view illustrating an electrode assembly in which a negative electrode tab of a secondary battery according to a first embodiment of the present invention is located;
7 is a flowchart illustrating a method for manufacturing a secondary battery according to a first embodiment of the present invention.
8 is a cross-sectional view illustrating a secondary battery according to a second embodiment of the present invention.
9 is a perspective view illustrating a protective film of a secondary battery according to a second embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily carry out the present invention. However, the present invention may be embodied in several different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

[Secondary battery according to the first embodiment of the present invention]

As shown in FIGS. 1 to 6 , the secondary battery 100 according to the first embodiment of the present invention includes an electrode assembly 110 , a can 120 accommodating the electrode assembly 110 , and a can 120 . It includes a cap assembly 130 mounted on the opening of the.

electrode assembly

The electrode assembly 110 has a structure in which a laminated sheet in which a positive electrode 111 and a negative electrode 112 are laminated with a separator 113 interposed therebetween is wound in a jelly-roll form. Here, the positive electrode 111 is provided with a positive electrode tab 111a coupled to the cap assembly 130 , and the negative electrode 112 is provided with a negative electrode tab 112a coupled to the can 120 .

Meanwhile, in the center of the electrode assembly wound in a jelly-roll shape, a core part 110a penetrating vertically as seen in FIG. 1 is formed.

can

The can 120 has a cylindrical shape, and includes a receiving part for accommodating the electrode assembly 110 , a coupling part provided on the upper side of the receiving part and coupled to the cap assembly, and a beading provided between the receiving part and the coupling water to support the cap assembly. It has a structure that includes parts. Here, the negative electrode tab 112a of the electrode assembly 110 is coupled to the bottom surface of the can.

cap assembly

The cap assembly 130 is for sealing the opening of the can, and has a structure in which a vent, a current breaker, a PTC, and a top cap are sequentially positioned from the bottom. Here, the positive electrode tab 111a of the electrode assembly 110 is coupled to the bottom surface of the vent.

On the other hand, in the secondary battery, when an external short circuit occurs, heat is generated in the positive electrode tab and the negative electrode tab, and the heat from the positive electrode tab and the negative electrode tab is transferred to the separator, causing the separator to contract, resulting in short circuit and fire. In particular, since the separator located in the core of the electrode assembly was tightly wound, there was a problem in that the positive electrode tab and the negative electrode tab greatly contract due to heat generation.

The secondary battery 100 according to the first embodiment of the present invention is provided at the end of the separator 113 exposed to the outside from the positive electrode or the negative electrode, and the heat of the positive electrode tab 111a or the negative electrode tab 112a is removed from the separator ( 113) may include a reinforcing member to prevent transmission to. As a result, it is possible to prevent shrinkage of the separation membrane, and to prevent short circuit or ignition.

That is, the reinforcing member blocks the strength reinforcement and heat transfer of the separator 113 adjacent to the positive electrode tab 111a and the negative electrode tab 112a, and the separator 113 located in the core portion 110a of the electrode assembly 110, As a result, it is possible to prevent contraction of the separation membrane 113 and to prevent short circuit and ignition.

For example, the reinforcing member includes a first reinforcing layer 140 and a second reinforcing layer 150 as shown in FIGS. 3 to 6 .

The first reinforcing layer 140 is provided while being coated on the surface of the separator 113 located in the core portion 110a of the electrode assembly 110 . That is, the first reinforcing layer 140 reinforces the strength of the separator 113 and blocks heat transfer to prevent the separator from being contracted.

In other words, referring to FIGS. 3 and 4 , the first reinforcing layer 140 is an end of the separator 113 exposed from the anode 111 and the cathode 112 (as viewed in FIG. 2 , the separator exposed from the anode and the cathode) top and bottom) of the same thickness), so the strength of the entire separator exposed to the outside of the positive and negative electrodes can be reinforced, and the high heat of the positive and negative tabs can be blocked from being transmitted to the separator, as a result It is possible to significantly prevent the contraction of the separation membrane 113 to prevent short circuit and fire.

Meanwhile, the first reinforcing layer 140 may be provided only on the end surfaces of the separator exposed to the outside of the anode and the cathode. Accordingly, an increase in the weight of the electrode assembly may be minimized, and the use of the first reinforcing layer may be minimized. That is, the shrinkage of the separator occurs on the end surfaces of the separator exposed to the outside of the positive electrode and the negative electrode, and accordingly, as the first reinforcement layer is provided only on the end surfaces of the separator exposed to the outside of the positive electrode and the negative electrode, unnecessary waste of the first reinforcement layer can prevent

Meanwhile, the reinforcing member may include a second reinforcing layer 150 coated on the separator 113 positioned within a set range based on the positive electrode tab 111a and the negative electrode tab 112a of the electrode assembly 110 .

In particular, the second reinforcing layer 150 may be provided only at the end of the separator positioned within a set range with respect to the positive electrode tab or the negative electrode tab.

That is, as shown in FIG. 4 , the second reinforcing layer 150 may be provided at the end of the separator 113 positioned within the set range α with respect to the positive electrode tab 111a, and accordingly, the positive electrode tab It is possible to prevent heat from being transferred to the separation membrane, and as a result, it is possible to prevent the separation membrane 113 from being contracted. In summary, it is possible to prevent contraction of the separator due to heat generation of the positive electrode tab during an external short circuit.

In particular, since the second reinforcing layer 150 is provided only at the end of the separator located within the set range α with respect to the positive electrode tab, unnecessary waste of the second reinforcing layer can be prevented, and as a result, the manufacturing cost can be greatly reduced. This eliminates the need to coat the second reinforcing layer up to the separator outside the set range because shrinkage occurs only to the separator positioned within the set range α with respect to the cathode tab when the cathode tab heats up.

Here, the setting range (α) may be a rotation radius of 2 mm to 10 mm based on the positive electrode tab. That is, the high heat of the positive electrode tab may be diffused from a rotation radius of 2 mm to 10 mm, and accordingly, it is necessary to provide a second reinforcing layer at the end of the separator located at a rotation radius of 2 mm to 10 mm based on the positive electrode tab. Meanwhile, the setting range may be set eccentrically with respect to the positive electrode tab according to the diffusion range of high heat generated in the positive electrode tab.

In addition, as shown in FIGS. 5 and 6 , the second reinforcing layer 150 may be provided at an end of the separator 113 positioned within a set range β with respect to the negative electrode tab 112a. Accordingly, it is possible to prevent the heat of the negative electrode tab from being transferred to the separator, and as a result, it is possible to prevent the separator 113 from being contracted. That is, it is possible to prevent contraction of the separator due to heat of the negative electrode tab during an external short circuit.

In particular, since the second reinforcing layer 150 is provided only at the end of the separator positioned within the set range β with respect to the negative electrode tab, unnecessary waste of the second reinforcing layer can be prevented, and as a result, manufacturing cost can be greatly reduced.

Here, the setting range β may be a rotation radius of 2 mm to 10 mm based on the negative electrode tab. That is, the high heat of the negative electrode tab can be spread from a rotation radius of 2 mm to 10 mm, and accordingly, it is necessary to provide a second reinforcing layer at the end of the separator located at a rotation radius of 2 mm to 10 mm based on the negative electrode tab.

Meanwhile, the second reinforcing layers 150 respectively coated on the separation membranes 113 corresponding to each other may be provided so as not to contact each other in order to prevent heat transfer. That is, a space may be formed between the second reinforcing layers 150 respectively coated on the corresponding separators 113 .

Meanwhile, the reinforcing member may be formed of a material having heat insulation properties and insulation properties. Accordingly, it is possible to prevent the heat of the positive electrode tab and the negative electrode tab from being transferred to the separator. For example, the reinforcing member may be ethylene propylene or epoxy.

Therefore, since the secondary battery 100 according to the first embodiment of the present invention includes a reinforcing member, it is possible to prevent heat from the positive electrode tab and the negative electrode tab from being transferred to the separator, and accordingly, It is possible to prevent shrinkage of the separation membrane, and as a result, short circuit and ignition can be prevented, thereby improving safety.

Hereinafter, a method for manufacturing a secondary battery according to a first embodiment of the present invention will be described.

[Method for manufacturing secondary battery according to the first embodiment of the present invention]

As shown in FIG. 7 , the secondary battery manufacturing method according to the first embodiment of the present invention includes (a) manufacturing an electrode assembly, (b) accommodating the electrode assembly in a can, (c) reinforcing member A coating step, (d) comprising the step of manufacturing a secondary battery.

In step (a), the electrode assembly ( 110) is prepared. At this time, referring to FIG. 1 , since the electrode assembly 110 is wound in a jelly-roll shape, a core portion 110a penetrating vertically is formed in the center of the electrode assembly.

In step (b), the electrode assembly 110 is inserted into the can 120 , and then the negative electrode tab 112a included in the electrode assembly 110 is coupled to the bottom surface of the can 120 .

In step (c), a reinforcing member is coated on the end of the separator 113 exposed to the outside from the positive electrode 111 or the negative electrode 112 so that the heat of the positive electrode tab 111a or the negative electrode tab 112a is removed from the separator 113 . to prevent transmission to

That is, step (c) includes a first reinforcing layer coating process, and in the first reinforcing layer coating process, the first reinforcing layer 140 is applied to only one surface of the separator 113 located in the core portion 110a of the electrode assembly 110 . coating Accordingly, while the heat of the positive electrode tab is blocked by the first reinforcing layer, it is possible to prevent shrinkage of the separator located in the core part. Here, the first reinforcing layer 140 is formed by applying a first protective liquid to the surface of the separator 113 and drying it.

In particular, in step (c), when the first reinforcing layer 140 is coated, the can 120 is vertically erected, and then the can 120 is rotated left and right. A first reinforcing layer is coated on one surface. Thereby, workability can be improved.

Meanwhile, step (c) further includes a second reinforcing layer coating process, wherein the second reinforcing layer coating process is performed only at the end of the separator positioned within a set range with respect to the positive electrode tab 111a or the negative electrode tab 112a. (150) is coated.

For example, as shown in FIG. 4 , the second reinforcing layer 150 may be coated on the end of the separator 113 positioned within a set range α with respect to the positive electrode tab 111a, and thus It is possible to prevent heat from being transferred to the separator.

Here, the setting range (α) may be a rotation radius of 2 mm to 10 mm based on the positive electrode tab.

In addition, as shown in FIG. 6 , the second reinforcing layer 150 may be provided at the end of the separator 113 positioned within the set range β with respect to the negative electrode tab 112a. Accordingly, it is possible to prevent the heat of the negative electrode tab from being transferred to the separator.

The setting range β may be a rotation radius of 2 mm to 10 mm based on the negative electrode tab.

Meanwhile, the reinforcing member may be formed of a material having heat insulation properties and insulation properties. For example, the first reinforcing layer may be formed of ethylene propylene or epoxy.

Meanwhile, the second reinforcing layers 150 respectively coated on the separation membranes 113 corresponding to each other in step (c) may be provided in a non-contact structure. It is possible to prevent high heat from being transferred to the second reinforcing layers corresponding to each other.

Meanwhile, the first reinforcing layer 140 and the second reinforcing layer 150 are formed of the same material, and the second reinforcing layer 150 is coated thinner than the first reinforcing layer 140 . This increases the thickness of the first coating layer because the core portion of the electrode assembly has a low heat dissipation power, and decreases the thickness of the second reinforcing layer because the heat dissipation power increases toward the outer shell of the electrode assembly.

In step (d), the positive electrode tab 111a of the electrode assembly 110 is coupled to the cap assembly 130 , and then the cap assembly 130 is coupled to the opening of the can 120 .

When the above steps are completed, the finished secondary battery 100 can be manufactured.

Hereinafter, in describing another embodiment of the present invention, the same reference numerals are used for components having the same configuration and functions as those of the above-described embodiment, and overlapping descriptions are omitted.

[Secondary battery according to the second embodiment of the present invention]

As shown in FIG. 8 , the secondary battery according to the second embodiment of the present invention includes an electrode assembly 110 , a can 120 accommodating the electrode assembly 110 , and a cap mounted in the opening of the can 120 . assembly 130 .

And the first reinforcing layer 140 coated on the core portion of the electrode assembly 110, and the second reinforcing layer 150 coated on the separator adjacent to the positive electrode tab 111a and the negative electrode tab 112a of the electrode assembly 110. include

Here, a protective layer 160 for protecting the first reinforcing layer 140 and the second reinforcing layer 150 is coated on the outside of the first reinforcing layer 140 and the second reinforcing layer 150 , and thus the first reinforcing layer 140 and the second reinforcing layer 150 are coated. Damage to the reinforcing layer 140 and the second reinforcing layer 150 may be prevented.

In particular, the protective layer 160 is coated to surround the entire first reinforcing layer 140 and the second reinforcing layer 150 , and thus the entire first reinforcing layer 140 and the second reinforcing layer 150 . can be reliably protected.

Meanwhile, the protective layer 160 may use an insulating material cheaper than the first reinforcing layer 140 and the second reinforcing layer 150 , thereby reducing manufacturing cost.

Hereinafter, a method for manufacturing a secondary battery according to a second embodiment of the present invention will be described.

[Method for manufacturing secondary battery according to the second embodiment of the present invention]

Referring to FIGS. 8 and 9, the secondary battery manufacturing method according to the second embodiment of the present invention includes (a) manufacturing an electrode assembly, (b) accommodating the electrode assembly in a can, (c) coating a reinforcing member step, (d) coupling the cap assembly to the can to manufacture a secondary battery.

Here, steps (a), (b), (c), and (d) have the same manufacturing method as that of the first embodiment described above, and thus overlapping descriptions will be omitted.

However, the secondary battery manufacturing method according to the second embodiment of the present invention further includes a protective layer coating process in step (c).

That is, in the protective layer coating process, as shown in FIG. 8 , the protective layer 160 is coated on the outside of the first reinforcing layer 140 and the second reinforcing layer 150 . In particular, the protective layer 160 is coated to cover the entire first reinforcing layer 140 and the second reinforcing layer 150 . Accordingly, the first reinforcing layer and the second reinforcing layer may be protected.

Meanwhile, step (c) may include a protective film attaching process before coating of the second reinforcing layer 150 with reference to FIG. 9 . In the protective film attaching process, the protective film 170 is attached to the positive electrode tab 111a to prevent the second reinforcing layer 150 from being coated on the positive electrode tab.

Meanwhile, step (c) may further include a protective film removal process when the coating of the second reinforcing layer 150 is completed. The protective film removal process may remove the protective film 170 attached to the positive electrode tab 111a to prevent contamination of the electrode assembly in advance.

The scope of the present invention is indicated by the following claims rather than the above detailed description, and various embodiments derived from the meaning and scope of the claims and their equivalent concepts are possible.

100: secondary battery
110: electrode assembly
110a: core part
111: positive electrode
111a: positive electrode tab
112: cathode
112a: negative electrode tab
113: separator
120: can
130: cap assembly
140: first reinforcing layer
150: second reinforcing layer
160: protective layer
170: protective film

Claims (15)

an electrode assembly in which a laminated sheet having a positive electrode having a positive electrode tab, a separator, and a negative electrode having a negative electrode tab is wound in a jelly-roll form, and a core portion is formed in the center;
a can into which the electrode assembly is inserted and to which the negative electrode tab is connected;
a cap assembly coupled to the opening of the can and to which the positive electrode tab is connected; and
A secondary battery comprising a reinforcing member provided at an end of the separator exposed to the outside from the positive electrode or the negative electrode and preventing heat of the positive electrode tab or the negative electrode tab from being transferred to the separator. The method according to claim 1,
The reinforcing member may include a first reinforcing layer provided only on one surface of the separator located in the core portion. 3. The method according to claim 2,
The reinforcing member may further include a second reinforcing layer provided only at an end of the separator positioned within a set range with respect to the positive electrode tab or the negative electrode tab. The method according to claim 1,
The reinforcing member is a secondary battery provided with a material having insulation and heat insulating properties. 4. The method according to claim 3,
The second reinforcing layers respectively provided on the surfaces of the separators corresponding to each other are provided so as not to contact each other in order to prevent heat transfer. (a) manufacturing an electrode assembly by winding a laminated sheet having a positive electrode having a positive electrode tab, a separator, and a negative electrode having a negative electrode tab in the form of a jelly-roll, and winding a core portion to be formed in the center;
(b) inserting the electrode assembly into the can, and then connecting the negative electrode tab included in the electrode assembly to the can;
(c) coating an end of the separator exposed to the outside from the positive electrode or the negative electrode with a reinforcing member to prevent heat from the positive electrode tab or the negative electrode tab from being transferred to the separator; and
(d) manufacturing a secondary battery by connecting the positive electrode tab of the electrode assembly to the cap assembly and then coupling the cap assembly to the opening of the can. 7. The method of claim 6,
In the step (c), the reinforcing member includes a first reinforcing layer coated on only one surface of the separator located in the core part. 8. The method of claim 7,
In the step (c), the reinforcing member further comprises a second reinforcing layer coated only on the end of the separator positioned within a set range with respect to the positive electrode tab or the negative electrode tab. 7. The method of claim 6,
In the step (c), the reinforcing member is a secondary battery manufacturing method that is provided with a material having insulation and heat insulating properties. 7. The method of claim 6,
The step (c) further comprises a protective layer coating process for protecting the reinforcing member while being coated on the outside of the reinforcing member. 11. The method of claim 10,
The method for manufacturing a secondary battery in which the protective layer is coated to surround the entire reinforcing member. 11. The method of claim 10,
In the step (c), the second reinforcing layers respectively coated on the surfaces of the separators corresponding to each other are coated so as not to contact each other to prevent heat transfer. 9. The method of claim 8,
In the step (c), before coating the second reinforcing layer, attaching a protective film to the positive electrode tab to prevent the second reinforcing layer from being coated on the positive electrode tab, and attaching to the positive electrode tab when the coating of the second reinforcing layer is completed A secondary battery manufacturing method further comprising a step of removing the old protective film. 8. The method of claim 7,
The step (c) is a secondary battery manufacturing method of coating the first reinforcement layer on one surface of the separator located in the core part in a state in which the can is vertically erected and then the can is rotated left and right when the first reinforcement layer is coated. . 9. The method of claim 8,
The setting range is a secondary battery manufacturing method with a rotation radius of 2 mm to 10 mm based on the positive electrode tab or the negative electrode tab.

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