CN105990596B - Method of manufacturing can for secondary battery and secondary battery using the same - Google Patents

Abstract

Provided are a method of manufacturing a can for a secondary battery and a secondary battery using the can, which can suppress failures such as wrinkles or cracks from occurring in the can for the secondary battery. The method includes: preparing a metal panel; cutting the metal panel to a predetermined length; forming a preform by forming a recessed portion at a central area of a top surface of the cut metal panel, the recessed portion having a thickness less than that of a surrounding portion thickness; and the top surface of the stamped preform.

Description

Method of manufacturing can for secondary battery and secondary battery using the same

This application claims priority to, and all rights and interests in, Korean Patent Application No. 10-2014-0146311 filed in the Korean Intellectual Property Office on October 27, 2014, the entire contents of which are hereby incorporated by reference.

technical field

The present invention relates to a method of manufacturing a can for a secondary battery and a secondary battery using the can.

Background technique

Generally, unlike primary batteries which are not rechargeable, secondary batteries can be discharged and recharged. The secondary battery may be of a low-capacity type including battery cells in the form of packs commonly used for small portable electronic devices such as cellular phones and camcorders, or a high-capacity type including battery cells used for A battery cell of a motor-driven power supply has several battery cells connected to each other and is widely used as a power supply for hybrid vehicles and the like.

Secondary batteries can be manufactured in various shapes, such as a cylindrical shape or a prismatic shape. A typical secondary battery may include an electrode assembly having a positive electrode plate and a negative electrode plate (a separator serving as an insulator is located between the positive electrode plate and the negative electrode plate) accommodated in a can together with an electrolyte, and a cap having an electrode terminal coupled to the can plate.

When the internal pressure of the secondary battery rises due to overheating caused by overcharge or decomposition of the electrolyte solution in the battery, combustion or explosion may occur in the secondary battery. Therefore, there is a need to manufacture secondary batteries with improved safety.

SUMMARY OF THE INVENTION

The present invention provides a method of manufacturing a can for a secondary battery and a secondary battery using the same, which can suppress the occurrence of failures such as wrinkles or cracks in the can for the secondary battery.

The present invention also provides a method of manufacturing a can for a secondary battery and a secondary battery using the can, which can reduce cutting by reducing a height difference between a long side surface and a short side surface of the can Scrap that is then discarded.

These and other objects of the present invention will be described in, or will be apparent from, the following description of the preferred embodiment.

According to an aspect of the present invention, there is provided a method of manufacturing a can for a secondary battery, the method comprising: preparing a metal panel; cutting the metal panel into a predetermined length; A recessed portion is formed at the central region to form the preform, the thickness of the recessed portion is smaller than that of the surrounding portion; and a top surface of the preform is punched.

After cutting the metal panel, the method of manufacturing the can for a secondary battery may further include forming rounded portions at corners of the cut metal panel.

In the step of stamping the preform, the preform may be formed into a can having a bottom surface and long and short side surfaces, the step of stamping the preform further comprising removing from upper regions of the long and short side surfaces scrap so that the long and short side surfaces have the same height.

In the step of forming the preform, the width of the recessed portion may be 10% to 90% of the width of the top surface of the preform.

In the step of forming the preform, the depth of the recessed portion may be 1% to 50% of the thickness of the preform.

During the step of punching, the punch pressing the top surface of the preform may contact the surrounding portion earlier than other portions of the top surface of the preform.

In the step of forming the preform, the top surface of the recessed portion may be flat.

In the step of forming the preform, the recessed portion may have a depth that gradually increases toward a central region of the recessed portion.

In the step of forming the preform, the top surface of the recessed portion may be circular or oval.

According to another aspect of the present invention, there is provided a secondary battery including: an electrode assembly including a first electrode plate, a second electrode plate, and a battery between the first electrode plate and the second electrode plate a separator; a can that accommodates the electrode assembly and has a top opening; a cover plate that seals the top opening of the can; and first and second electrode terminals that are electrically connected to the first and second electrode plates and protrude to the cover plate The upper portion of the metal panel wherein the tank is formed by stamping a preform having a recess formed at a central region of the top surface of the metal panel, the recessed portion having a thickness less than the thickness of the surrounding portion of the top surface of the metal panel.

The width of the recessed portion may be 10% to 90% of the width of the top surface of the preform.

The depth of the recessed portion may be 1% to 50% of the thickness of the preform.

As described above, according to the method of manufacturing the can for a secondary battery and the secondary battery using the same, it is possible to suppress the occurrence of failures such as wrinkles or cracks in the can for the secondary battery.

In addition, according to the method of manufacturing a can for a secondary battery and a secondary battery using the same, scrap that is cut and then discarded can be reduced by reducing the height difference between the long side surface and the short side surface of the can.

Description of drawings

The above and other features and advantages of the present invention will become more apparent by describing in detail preferred embodiments of the present invention with reference to the accompanying drawings, in which:

1 is a flowchart illustrating a method of manufacturing a can for a secondary battery according to an embodiment of the present invention;

2 to 10 are a perspective view, a top view, and a side view sequentially illustrating a method of manufacturing a can for a secondary battery according to an embodiment of the present invention;

11 is a cross-sectional view illustrating a secondary battery employing a can for a secondary battery according to an embodiment of the present invention;

12 shows a perspective view, a top view and a side view showing a preform for a can of a secondary battery according to another embodiment of the present invention;

FIG. 13 shows a perspective view, a top view, and a side view showing a preform of a can for a secondary battery according to yet another embodiment of the present invention.

Detailed ways

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings; however, they may be embodied in 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 disclosure to those skilled in the art.

As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. The terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the invention. As used herein, the singular forms are also intended to include the plural forms unless the context clearly dictates otherwise. It will also be understood that when the terms "comprising" and/or "comprising" are used in this specification, it indicates the presence of the stated features, integers, steps, operations, elements and/or components, but does not preclude the presence or addition of one or Still other features, integers, steps, operations, elements, components and/or groups thereof.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another.

1 is a flowchart illustrating a method of manufacturing a can for a secondary battery according to an embodiment of the present invention, and FIGS. 2 to 10 are sequentially illustrating a method of manufacturing a can for a secondary battery according to an embodiment of the present invention. Perspective, top and side views of the tank method.

First, referring to FIG. 1 , a method of manufacturing a can for a secondary battery according to an embodiment of the present invention includes: preparing a metal panel ( S10 ); cutting the metal panel ( S20 ); forming a circular portion ( S30 ); forming a preform parts (S40); punching (S50); and scrap removal (S60).

Referring to FIG. 2, in the step of preparing a metal panel (S10), a metal panel 1 to be formed into a can in a subsequent process is prepared. Here, the metal panel 1 is formed by cold forging (specifically, rolling or extrusion) using a long plate-shaped panel. In addition, the metal panel 1 is made of conductive metal such as aluminum, aluminum alloy, or nickel-plated steel.

Next, referring to FIG. 3 , in the step of cutting the metal panel ( S20 ), the metal panel 1 is cut into a predetermined length to be divided into a plurality of metal panels 10 .

Next, referring to FIG. 4 , in the step of forming the rounded portion ( S30 ), the rounded portion 12 is formed at the corner of each cut metal panel 10 and the bottom surface of the corner. Therefore, the long side surfaces of the formed product (ie, the can) can be prevented from being cracked due to cracks generated in the opening of the can, so that the appearance of the can can be made clean and neat without crack marks.

5 and 6, in the step of forming the preform (S40), a recessed portion 11a is formed at the central region of the top surface 11 of the cut metal panel 10 to form the preform 10'. Here, the recessed portion 11a is formed by further pressing or cutting the top surface 11 of the metal panel 10 downward. Therefore, compared with the peripheral portion 11b of the top surface 11 of the metal panel 10, the central region where the recessed portion 11a is formed has a smaller thickness. In addition, the top surface of the recessed portion 11a may be flat.

Here, the width D1 _of the recessed portion 11a is preferably ₁₀ % to 90% of the width D2 of the top surface of the preform 10'. When the width D1 _of the recessed portion 11a is less _than 10% of the width D2 of the top surface of the preform 10', the effect of reducing the height difference between the long side surface and the short side surface of the can in the process of forming the can is negligible. When the width D1 _of the recessed portion 11a is greater _than 90% of the width D2 of the top surface of the preform 10', the possibility of securing the height of the can is reduced.

In addition, the depth _H2 of the recessed portion 11a is preferably ₁ % to 50% of the thickness H1 of the preform 10'. When the depth _H2 of the recessed portion 11a is less than ₁ % of the thickness H1 of the preform 10', the effect of reducing the height difference between the long side surface and the short side surface of the can is in forming a stamping to be described later. The process of forming the tank during the process is negligible. When the depth _H2 of the recessed portion 11a is greater _than 50% of the thickness H1 of the preform 10', compared with the height of the long side surface at the center region of the can in the punching process to be described later, it is ensured that the can The possibility of the height of the short side surface is significantly reduced.

Next, referring to FIGS. 7 to 9 , in the step of punching ( S50 ), the preform 10 ′ is mounted on the die D and the top surface of the preform 10 ′ is pressed by the punching machine P to form a bottom surface 100 a and side surface 100b of the tank. Stamping (S50) may be performed through a deep drawing process or a punch forging process.

Here, when the punch P presses the top surface of the preform 10', the punch P contacts the surrounding portion 11b earlier than the other portions. Therefore, the concentration of plastic flow will occur earlier on the surrounding portion 11b, and the plastic flow will be less concentrated on the preform 10' compared to other parts of the preform 10' formed as the short side surface of the tank is formed as a central area (ie, the recessed portion 11a) of the long side surface of the can, thereby reducing the height difference between the long side surface and the short side surface of the can. That is, in order to make the long side surface and the short side surface of the can have the same height, by suppressing the generation of waste due to the reduced height difference between the long side surface and the short side surface of the can, cutting and then discarding can be reduced of waste.

As shown in FIG. 8 , when the punching is performed using the deep drawing process ( S50 ), as the areas of the die D and the punch P are gradually reduced, the area of the bottom surface 100 a of the can is gradually reduced and the side surface 100 b of the can is gradually reduced The length is gradually increased to finally form the can with the desired shape due to excessive force applied to the preform 10' when the deep drawing process is performed by initially setting the area of the die D and punch P as required Cracks may develop in the final produced can.

However, in a punch forging process, using a metal block to form the preform 10', a can product that is 80% to 90% complete can be formed through a single forging process using mechanical pressure.

As described above, the stamping process is finally performed, thereby forming the can 100 ′ having the bottom surface 100 a , the long side surfaces 100 b and the short side surfaces 100 c , as shown in FIG. 9 .

Here, since there is a difference between the height _H3 of each long side surface 100b and the height H4 _of each short side surface 100c of the tank 100', it is necessary to remove the height H4 based _on each short side surface 100c the upper area of the cutting line C.

Referring to Table 1, it can be confirmed that as the depth _H2 of the recessed portion 11a increases, the difference between the height _H3 of each long side surface 100b and the height H4 _of each short side surface 100c of the can 100' difference decreases. Here, the thickness H ₁ of the preform 10 ′ used in the experiment was 9 mm.

Table 1

Next, referring to FIGS. 9 and 10 , in the step of removing the scrap ( S60 ), as described above, the scrap S in the upper region of the cutting line C is removed, thereby forming a long side surface 100 b and a short side surface including equal heights Tank 100 of 100c, as shown in FIG. 10 .

11 is a cross-sectional view illustrating a secondary battery employing a can for a secondary battery according to an embodiment of the present invention.

11 , a secondary battery 1000 according to an embodiment of the present invention includes a can 100, an electrode assembly 110, a first current collector plate 120, a first terminal part 130, a second current collector plate 150, a second terminal part 160, and a cover Component 180 . A plurality of secondary batteries 1000 may be connected in series to constitute a large-capacity battery pack that outputs a high voltage.

As described above, the can 100, which is a can manufactured by the method of manufacturing a can for a secondary battery, may be made of conductive metal such as aluminum, aluminum alloy, or nickel-plated steel, and may have an approximately hexahedral shape, so The hexahedral shape has a top opening 101 through which the electrode assembly 110, the first current collector plate 120 and the second current collector plate 150 can be inserted and placed. Because the can 100 and lid assembly 180 are shown engaged with each other in FIG. 11 , the top opening 101 is not shown in detail, but corresponds to a substantially open portion of the rim of the lid assembly 180 . Meanwhile, the inner surface of the can 100 according to this embodiment may be insulated from the electrode assembly 110 , the first current collector plate 120 , the second current collector plate 150 , and the cap assembly 180 .

The electrode assembly 110 includes a rolled or laminated stack structure having a first electrode plate 111 , a separator 113 and a second electrode plate 112 , and may be in the shape of a thin plate or a thin foil. In this embodiment, the first electrode plate 111 may be a negative electrode, and the second electrode plate 112 may be a positive electrode, but the present invention is not limited to this embodiment.

The first electrode plate 111 may include a negative electrode current collector formed of a thin conductive metal plate (eg, made of a foil or material of copper (Cu) or nickel (Ni)) and a negative electrode current collector coated on opposite surfaces of the negative electrode current collector. Negative active material. In addition, the first electrode plate 111 may include a first electrode uncoated portion 111a to which the first electrode active material is not coated.

The first electrode uncoated portion 111 a may serve as a passage for current to flow between the first electrode plate 111 and the outside of the first electrode plate 111 . The present invention is not limited to the materials of the first electrode plate 111 listed here, and may be any suitable material recognized by those skilled in the art.

The second electrode plate 112 may include a positive electrode current collector made of a foil or material of aluminum (Al) and a positive electrode active material coated on opposite surfaces of the positive electrode current collector. In addition, the second electrode plate 112 may include a second electrode uncoated portion 112a to which the anode active material is not coated.

The second electrode uncoated portion 112 a may serve as a passage for current to flow between the second electrode plate 112 and the outside of the second electrode plate 112 . The present invention is not limited to the materials of the second electrode plate 112 listed here, and may be any suitable material recognized by those skilled in the art.

In other embodiments, the polarities of the first electrode plate 111 and the second electrode plate 112 may be different from those described above. That is, the first electrode plate 111 may be a positive electrode, and the second electrode plate 112 may be a negative electrode.

The separator 113 may be located between the first electrode plate 111 and the second electrode plate 112 to prevent electrical short circuit and allow movement of lithium ions. The separator 113 according to this embodiment may be made of a material selected from the group consisting of polyethylene, polypropylene, or a copolymer of polypropylene and polyethylene. In a preferred embodiment, the separator 113 has a larger width than the first electrode plate 111 or the second electrode plate 112 , which may be advantageous in preventing a short circuit between the first electrode plate 111 and the second electrode plate 112 .

The first collector plate 120 and the second collector plate 150 electrically connected to the first electrode plate 111 and the second electrode plate 112 are bonded to opposite ends of the electrode assembly 110, respectively. Preferably, the first current collector plate 120 and the second current collector plate 150 are bonded to the first electrode uncoated portion 111a and the second electrode uncoated portion 112a corresponding to opposite ends of the electrode assembly 110, respectively.

The electrode assembly 110 and the electrolyte are provided in the tank 100 . The electrolyte may include organic solvents such as ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC) or dimethyl carbonate (DMC) and organic solvents such as LiPF ₆ Or the lithium salt of _LiBF4 . Electrolytes can be liquid, solid or gel. The first current collector plate 120 may be formed of a conductive metal such as aluminum, copper, copper alloys, and their equivalents.

The first current collector plate 120 contacts the first electrode uncoated portion 111 a protruding to one end of the electrode assembly 110 to be electrically connected to the first electrode plate 111 . The first current collector plate 120 includes a first electrode connection part 121 connected to the first electrode plate 111 , a first terminal connection part 122 connected to the first terminal part 130 , and a first electrode connection part 121 and a first terminal connection part 122 of the first connecting portion 123 . The first current collector plate 120 may be integrally formed. The first current collector plate 120 includes a corner portion formed by bending the first connection portion 123 so that the first current collector plate 120 has a substantially "L"-shaped configuration.

The first electrode connection portion 121 contacts the first electrode uncoated portion 111 a protruding to one end of the electrode assembly 110 to be electrically connected to the first electrode plate 111 . The first electrode connection portion 121 is welded to the first electrode uncoated portion 111a and is disposed vertically.

The first terminal connection part 122 is welded to the first terminal part 130 and has the shape of a plate disposed in a substantially horizontal direction to be installed between the cap plate 181 of the cap assembly 180 and the electrode assembly 110 to be described later. The first terminal hole 122 a is formed through a portion between the top and bottom surfaces of the first terminal connection portion 122 . The first electrode terminal 131 of the first terminal part 130 is fitted and coupled to the first terminal hole 122a. That is, the first terminal holes 122 a may be dimensioned to correspond to the first electrode terminals 131 to receive the first electrode terminals 131 .

The first connection part 123 may have one side connected to the first electrode connection part 121 and the other side connected to the first terminal connection part 122 . The first connection portion 123 may have an angle C1 curved between the one side and the other side, and may have a generally "L"-shaped configuration.

The first terminal portion 130 may generally be formed of metal or metal equivalents, and may be electrically connected to the first current collector plate 120 . The first terminal part 130 may include a first electrode terminal 131 accommodated in the first terminal hole 122 a of the first current collector plate 120 , a first terminal plate 132 coupled to the first electrode terminal 131 , and a first connection plate 133 .

The first electrode terminal 131 may pass through the cap plate 181 , which will be described later, to extend upward and protrude by a predetermined length and be electrically connected to the first current collector plate 120 under the cap plate 181 . The first electrode terminal 131 extends upward from the cap plate 181 and protrudes by a predetermined length, and may have a laterally extending flange 131 a formed under the cap plate 181 to prevent the first electrode terminal 131 from being detached from the cap plate 181 . In the first electrode terminal 131, a region formed under the flange 131a may be fitted into the first terminal hole 122a of the first current collector plate 120, and then riveted or welded. In addition, in the first electrode terminal 131, a region formed on the flange 131a may pass through the cap plate 181 to extend upward and protrude by a predetermined length, and the first connection plate 133 may be fixed to the extended and protruded region.

The first connection plate 133 may be spaced apart from the cover plate 181 by an upper insulating member 184 to be described later to be disposed in parallel with the cover plate 181 .

The first connection plate 133 may be generally formed of metal or metal equivalent, and may be electrically connected to the first electrode terminal 131 . The first terminal hole 133a is formed in the first connection plate 133 to allow the upper region of the first electrode terminal 131 to pass therethrough.

The second current collector plate 150 includes a second electrode connection part 151 connected to the second electrode plate 112 , a second terminal connection part 152 connected to the second terminal part 160 , and a second electrode connection part 151 and a second terminal connection part connected 152 of the second connecting portion 153 . The second current collector plate 150 may be integrally formed. The second current collector plate 150 includes a corner portion formed by bending the second connection portion 153 so that the second current collector plate 150 has a generally "L"-shaped configuration. The second current collector plate 150 may be formed of a conductive material selected from aluminum, aluminum alloys, and their equivalents.

The second electrode connection portion 151 contacts the second electrode uncoated portion 112 a protruding to one end of the electrode assembly 110 to be electrically connected to the second electrode plate 112 . The second electrode connection portion 151 is welded to the second electrode uncoated portion 112a and is disposed vertically.

The second terminal connection part 152 is welded to the second terminal part 160 and has the shape of a plate arranged in a substantially horizontal direction to be installed between the cap plate 181 of the cap assembly 180 and the electrode assembly 110 to be described later.

The second terminal hole 152 a and the fuse hole 152 b are formed in the second terminal connection part 152 to pass through a portion between the top surface and the bottom surface of the second terminal connection part 152 . The second electrode terminal 161 of the second terminal part 160 is fitted and coupled to the second terminal hole 152a. That is, the second terminal hole 152a may be dimensioned to correspond to the second electrode terminal 161 to receive the second electrode terminal 161 .

In the second terminal connection portion 152 , the fusible hole 152 b is located at a region adjacent to the corner C2 so as not to overlap with the second terminal hole 152 a coupled to the second electrode terminal 161 . The region where the fuse hole 152b is formed has a smaller cross-sectional area than other regions of the second terminal connection portion 152 .

Therefore, the region where the fuse hole 152b is formed can be melted by high heat generated when a high current of 3000A or more flows instantaneously due to a high current short circuit occurring in the secondary battery 1000, thereby serving as a fuse for breaking the current.

Here, when heat is generated due to overcharging of the secondary battery 1000 and the electrolyte is decomposed, when the inverted plate 189 of the cap assembly 180 and the first connection plate 133 to be described later come into contact with each other, a high current short circuit may be caused. In addition, in the case of pressing the secondary battery 1000 in the Y-axis direction, when the second terminal portion 160 and the other side of the first connection plate 133 are in contact with each other, a short circuit of high current is also caused. In the case of pressing the secondary battery 1000 in the Z-axis direction, when the bottom surfaces of the cap plate 181 and the first connection plate 133 may come into direct contact with each other, a high current short circuit may also be caused. That is, since the region where the fuse hole 152b is formed is melted to interrupt the current due to the short circuit of the high current, the charging or discharging operation of the secondary battery 1000 can be stopped before facing a dangerous situation such as fire or explosion.

The second connection part 153 may have one side connected to the second electrode connection part 151 and the other side connected to the second terminal connection part 152 . The second connecting portion 153 may have a corner C2 curved between the one side and the other side, and may have a generally "L"-shaped configuration.

The second terminal portion 160 may generally be formed of metal or a metal equivalent, and may be electrically connected to the second current collector plate 150 . In addition, the second terminal part 160 may be electrically connected to the cap plate 181 . The second terminal part 160 may include a second electrode terminal 161 accommodated in the second terminal hole 152 a of the second current collector plate 150 and a second terminal plate 162 coupled to the second electrode terminal 161 .

The second electrode terminal 161 may pass through the cap plate 181 , which will be described later, to extend upward and protrude by a predetermined length and be electrically connected to the second current collector plate 150 under the cap plate 181 . The second electrode terminal 161 extends upward from the cap plate 181 and protrudes by a predetermined length, and may have a laterally extending flange 161 a formed under the cap plate 181 to prevent the second electrode terminal 161 from being detached from the cap plate 181 . In the second electrode terminal 161, a region formed under the flange 161a may be fitted into the second terminal hole 152a of the second current collector plate 150, and then riveted or welded. In addition, in the second electrode terminal 161, a region formed on the flange 161a may pass through the cap plate 181 to extend upward and protrude by a predetermined length, and the second terminal plate 162 may be fixed to the extended and protruded region.

The second terminal plate 162 is in the shape of a plate having second terminal holes 162a through which the second terminal plate 162 passes. The second terminal holes 162 a of the second terminal plate 162 may be horizontally dimensioned and shaped to correspond to the second electrode terminals 161 to receive the second electrode terminals 161 . The second electrode terminals 161 protruding upward from the cover plate 18 are fitted into the second terminal holes 162a of the second terminal plate 162, and then riveted or welded.

The second terminal portion 160 may be formed of a conductive material selected from aluminum, aluminum alloys, and their equivalents, but is not limited thereto.

Cap assembly 180 is coupled to canister 100 . In detail, the cover assembly 180 includes a cover plate 181 , sealing gaskets 182 and 187 , a safety hole 183 , upper insulating members 184 and 186 , lower insulating members 185 and 188 , and an inverted plate 189 .

The cover plate 181 may seal the top opening 101 of the can 100 and may be formed of the same material as the can 100 . For example, the cover plate 181 may be bonded to the can 100 by laser welding. The cap plate 181 may be electrically connected to the second terminal part 160 such that the cap plate 181 has the same polarity as the second terminal part 160 . Therefore, the cover plate 181 and the canister 100 may have the same polarity. The cover plate 181 may include a vent hole 181 a and a short-circuit hole 181 b passing through a portion between the top and bottom surfaces of the cover plate 181 . Here, the short-circuit hole 181b is located below the connection plate 133 .

The sealing gaskets 182 and 187 are formed of an insulating material, and include a first sealing gasket 182 formed between the first electrode terminal 131 and the cap plate 181 and a second sealing gasket 182 formed between the second electrode terminal 161 and the cap plate 181 Gasket 187. The sealing gaskets 182 and 187 seal the portion between each of the first electrode terminal 131 and the second electrode terminal 161 and the cap plate 181 . The first sealing gasket 182 and the second sealing gasket 187 may prevent external moisture from permeating into the secondary battery 1000 or prevent electrolyte contained in the secondary battery 1000 from flowing out.

The safety hole 183 may be installed in the vent hole 181a of the cover plate 181 and may have a notch configured to open under a predefined pressure.

The upper insulating members 184 and 186 may include a first upper insulating member 184 formed between the connection plate 133 and the cap plate 181 and a second upper insulating member 186 formed between the second terminal plate 162 and the cap plate 181 .

The first upper insulating member 184 electrically insulates the connection plate 133 and the cap plate 181 from each other. In addition, the first upper insulating member 184 may include a first upper insulating member hole 184a formed under the connection plate 133 and an extension portion 184b protruding upward from the first terminal hole 133a of the connection plate 133, and the extension portion 184b may allow the connection plate 133 and the first electrode terminal 131 are electrically insulated from each other.

In addition, the first upper insulating member 184 may be closely attached to the cover plate 181 . In addition, the first upper insulating member 184 may also be closely attached to the first sealing gasket 182 . The first upper insulating member 184 may electrically insulate the first terminal part 130 and the cap plate 181 from each other.

The second upper insulating member 186 may be formed between the second terminal plate 162 and the cap plate 181 , but a portion of the second terminal plate 162 may contact the cap plate 181 to be electrically connected with the cap plate 181 .

The lower insulating members 185 and 188 may include a first lower insulating member 185 formed between the first current collector plate 120 and the cap plate 181 and a second lower insulating member formed between the second current collector plate 150 and the cap plate 181 188.

The first lower insulating member 185 and the second lower insulating member 188 may prevent unnecessary electrical shorts from occurring between each of the first and second current collector plates 120 and 150 and the cap plate 181 . That is, the first lower insulating member 185 and the second lower insulating member 188 can prevent unnecessary occurrences between the first current collector plate 120 and the cap plate 181 and between the second current collector plate 150 and the cap plate 181 Electrical short circuit. In addition, the first lower insulating member 185 and the second lower insulating member 188 are formed between each of the first electrode terminal 131 and the second electrode terminal 161 and the cap plate 181, thereby preventing the An unnecessary electrical short occurs between each of the electrode terminals 161 and the cap plate 181 .

The inverted plate 189 is provided in the short-circuit hole 181 b of the cover plate 181 and is covered by the first connection plate 133 . Here, the inverted plate 189 includes a circular portion protruding downward and an edge portion fixed to the cover plate 181 . The inverted plate 189 and the cover plate 181 may have the same polarity.

When the internal pressure exceeds a predetermined pressure due to overcharge of the secondary battery 1000, the inversion plate 189 may be reversed to protrude convexly upward, so that the fusing portion functions properly.

12 shows a perspective view, a top view and a side view showing a preform of a can for a secondary battery according to another embodiment of the present invention, and FIG. 13 shows a perspective view, a top view and a side view A can preform for a secondary battery according to yet another embodiment of the present invention is shown.

Referring to FIG. 12 , in a preform 20 ′ for a can for a secondary battery according to another embodiment of the present invention, the recessed portion 21 a may have a depth gradually increasing toward a central region thereof. That is, the concave portion 21a has an inverted dome-shaped configuration when viewed from the side.

Referring to FIG. 13 , in a preform 30 ′ for a can for a secondary battery according to still another embodiment of the present invention, the recessed portion 31 a may have a depth gradually increasing toward a central region thereof, and seen from a plan view, Can have a circular or oval configuration. That is, the recessed portion 31a may be in the shape of a funnel.

Although the recessed portion 11a of the can preform 10' for a secondary battery according to the embodiment of the present invention has a stepped height difference, the configuration shown in FIGS. 12 and 13 has an inverted arch shape and the funnel-shaped configuration of each of preforms 20' and 30' may selectively control the height of the long side surfaces of the final produced can.

While the present invention has been particularly shown and described with reference to the exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that forms may be made herein without departing from the spirit and scope of the invention as defined by the claims. Various changes in top and detail.

Claims (11)

1. a kind of method of tank of manufacture for secondary cell, which comprises

Prepare metal decking；

Metal decking is cut into scheduled length；

Recess is formed by the central area of the top surface of the metal decking in cutting to form preformed member, recess The thickness divided is less than the thickness of peripheral part；And

The top surface of punching press preformed member,

Wherein, in the punching press the step of, press the press machine of the top surface of preformed member than preformed member top surface other Part contacts peripheral part earlier.

2. according to the method described in claim 1, further including at the angle of the metal decking of cutting after cutting metal decking Form circular portion.

3. according to the method described in claim 2, wherein, the punching press preformed member the step of in, preformed member is formed as having The step of having the tank of bottom surface and long side surface and short side surface, punching press preformed member further includes from long side surface and short side table The upper area in face removes waste material, so that long side surface and short side surface height having the same.

4. according to the method described in claim 1, wherein, in the step of forming preformed member, the width of recess is pre- The 10% to 90% of the width of the top surface of molded part.

5. according to the method described in claim 1, wherein, in the step of forming preformed member, the depth of recess is pre- The 1% to 50% of the thickness of molded part.

6. according to the method described in claim 1, wherein, in the step of forming preformed member, the top surface of recess is Flat.

7. according to the method described in claim 1, wherein, in the step of forming preformed member, recess has towards recessed The depth being gradually increased into the central area of part.

8. according to the method described in claim 7, wherein, in the step of forming preformed member, the top surface of recess is It is circular or oval.

9. a kind of secondary cell, the secondary cell include:

Electrode assembly, including first electrode plate, second electrode plate and between first electrode plate and second electrode plate every Plate；

Tank, accommodate electrod component simultaneously have top opening；

Cover board, the top opening of hermetically sealed can；And

First electrode terminal and second electrode terminal are electrically connected to first electrode plate and second electrode plate and are projected into the upper of cover board Portion,

Wherein, tank has the preformed member of the recess of the central area for the top surface for being formed in metal decking by punching press It being formed, the thickness of recess is less than the thickness of peripheral part of the top surface of metal decking,

Wherein, in the punching press the step of, press the press machine of the top surface of preformed member than preformed member top surface other Part contacts peripheral part earlier.

10. secondary cell according to claim 9, wherein the width of recess is the width of the top surface of preformed member The 10% to 90% of degree.

11. secondary cell according to claim 9, wherein the depth of recess be preformed member thickness 1% to 50%.