KR101264423B1 - The method sealing electrolyte pouring hole of battery - Google Patents

Abstract

According to an aspect of the present invention, a method for sealing an electrolyte injection hole, which is a passage for injecting an electrolyte into a battery case, includes: preparing a sealing material of a plastically deformable material surrounding a core material; Inserting the sealing material into the electrolyte injection hole; And pulling the core material to the outside so that the sealing material is plastically deformed to seal the electrolyte injection hole.

Therefore, the sealing property of the electrolyte injection hole is improved, and even if the welding and curing agent coating process performed after the electrolyte injection hole sealing is omitted, the electrolyte injection hole can be sealed.

Description

Sealing method of electrolyte injection hole of battery {THE METHOD SEALING ELECTROLYTE POURING HOLE OF BATTERY}

1 is an exploded perspective view illustrating a secondary battery according to an embodiment of the present invention;

2A and 2B are cross-sectional views showing before and after sealing of an electrolyte injection hole of a secondary battery according to an embodiment of the present invention;

3A and 3B are cross-sectional views showing before and after sealing of an electrolyte injection hole of a secondary battery according to another embodiment of the present invention;

4A and 4B are cross-sectional views illustrating before and after sealing of an electrolyte injection hole of a secondary battery according to still another exemplary embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10: secondary battery 11: can

12: electrode assembly 100: cap assembly

110: cap plate 112: electrolyte injection hole

200, 200 ', 200 ": seal 210, 210', 210": seal

211, 211 ', 211 ": Body 212, 212', 212": Bottom

213 ', 213 ": Head 230, 230', 230": Heartwood

250: contact member

The present invention relates to a method for sealing an electrolyte injection hole of a battery in which the sealing property of the electrolyte injection hole is improved.

In general, a secondary battery refers to a battery that can be charged and discharged, unlike a primary battery that cannot be charged, and is widely used in the field of advanced electronic devices such as a cellular phone, a notebook computer, a camcorder, and the like. In particular, lithium secondary batteries have an operating voltage of 3.6V, which is three times higher than nickel-cadmium batteries or nickel-hydrogen batteries, which are widely used as electronic equipment power sources, and are rapidly increasing in terms of high energy density per unit weight.

The secondary battery is classified into a liquid electrolyte battery and a polymer electrolyte battery according to the type of electrolyte. A battery using a liquid electrolyte is called a lithium ion battery, and a battery using a polymer electrolyte is called a lithium polymer battery. In the case of a lithium secondary battery, a nonaqueous electrolyte is used even when using a liquid electrolyte because of the reactivity of lithium and water (H ₂ O). As the non-aqueous electrolyte is used, the lithium ion battery may have a relatively high battery voltage because it is not controlled by the decomposition voltage of water during charging. The liquid electrolyte has a state in which the lithium salt is dissociated from the organic solvent. As the solvent in which the lithium salt is dissolved, ethylene carbonate, propylene carbonate or other alkyl group-containing carbonate or similar organic compound is used.

In a lithium secondary battery using a solid electrolyte, there will be no leakage problem of the electrolyte, but in the case of a lithium ion battery using a liquid electrolyte, preventing leakage of the electrolyte is an important problem as in the case of a general chemical battery. In particular, the problem of preventing leakage of electrolyte becomes more important, considering that portable phones, computers, personal digital assistants, camcorders, etc., in which lithium ion batteries are used as power sources, are expensive precision devices.

The secondary battery includes an electrode assembly, a can containing the electrode assembly and the electrolyte, and a cap assembly coupled to an open upper portion of the can.

In the electrode assembly, a positive electrode and a negative electrode and a separator interposed between these two electrodes are wound, and the positive and negative electrode tabs are drawn out from the positive and negative electrodes, respectively.

The can is a metal container having a substantially rectangular parallelepiped shape in a rectangular secondary battery, and is formed by a processing method such as deep drawing. It is therefore possible for the can itself to act as a terminal.

The cap assembly includes a cap plate coupled to an upper portion of the can, an electrode terminal provided through a terminal hole, and a gasket for insulating the cap plate on an outer surface thereof, an insulating plate installed on a lower surface of the cap plate, and the insulation It is provided on the bottom surface of the plate and comprises a terminal plate that is energized with the electrode terminal. The negative electrode of the electrode assembly is electrically connected to the electrode terminal through the negative electrode tab and the terminal plate, and the positive electrode is electrically connected to the cap plate or the can through the positive electrode tab. Of course, it is also possible to design by changing the polarity.

On one side of the cap plate, an electrolyte injection hole is formed, which is a passage through which electrolyte is injected into the can, and the electrolyte injection hole has a ball having a larger size than the electrolyte injection hole at the inlet of the electrolyte injection hole after the electrolyte injection. It is sealed by indentation.

Furthermore, laser welding is performed along the edge of the sealed part, and the method which prevents leakage of electrolyte solution is selected by coating with the ultraviolet curing agent etc. over the area | region containing the said sealing part and a welding part.

However, the electrolyte injection hole sealing structure and the sealing method has the following problems.

When press-fitting a ball having a larger size than the electrolyte injection hole at the inlet of the electrolyte injection hole, the position distribution of the ball is very large, and the ball is directed to one side of the electrolyte injection hole entrance without obtaining a desired sealing shape. It is very likely that defects will be indented. As a result, defects occur in the subsequent welding and curing agent coating process.

Therefore, a phenomenon in which the electrolyte injected into the battery leaks along the inner wall of the electrolyte injection hole may occur, resulting in a decrease in the reliability of the battery.

The present invention is to solve the above problems, and improve the sealing property of the electrolyte injection hole, and further has a structure that ensures the sealing of the electrolyte injection hole even if the welding and curing agent coating process performed after sealing the electrolyte injection hole is omitted. It is an object of the present invention to provide a method for sealing the electrolyte injection hole.

A secondary battery according to an aspect of the present invention for achieving the above object,

And a cap assembly including an electrode assembly, a can housing accommodating the electrode assembly and the electrolyte solution, a cap plate on which an electrolyte injection hole is coupled to an open upper portion of the can, and a sealing part sealing the electrolyte injection hole. Blowing,

A sealing member made of a plastically deformable material including a body portion penetrating the electrolyte injection hole and a bottom portion formed integrally with the body portion and in close contact with a bottom surface of the cap plate of the outer peripheral edge of the electrolyte injection hole;

It is surrounded by the sealing material coupled to at least a portion of the sealing material, it characterized in that it comprises a core material made of a harder material than the sealing material.

Here, the bottom portion of the sealing material may be formed by pulling the core material upwards.

In addition, the sealing member and the cap plate may include an adhesive member located at least a section.

In addition, the sealing material may be formed integrally with the body portion and may include a head portion in close contact with the upper surface of the cap plate of the inlet side outer periphery of the electrolyte injection hole.

At this time, the contact member may be located at the outer periphery of the inlet and outlet side of the electrolyte injection hole.

On the other hand, the electrolyte injection hole sealing method of the battery according to another aspect of the present invention for achieving the above object,

Preparing a sealing material of a plastically deformable material surrounding the core material;

Inserting the sealing material into the electrolyte injection hole; And

And a step of pulling the core material to the outside so that the sealing material is plastically deformed to seal the electrolyte injection hole.

At this time, after the step of pulling the core material to the outside, it may include a step of cutting the portion protruding outward from the sealing material around the core material.

In addition, when the sealing material is inserted into the electrolyte injection hole, the adhesion member may be positioned in at least a portion of a portion of the battery case in which the electrolyte injection hole is formed and the sealing material.

In addition, when pulling the core material to the outside, the portion of the sealing material exposed to the outside of the battery may be pressed in the direction opposite to the direction of pulling the core material to the outside.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of a secondary battery according to the present invention.

1 is an exploded perspective view illustrating a rechargeable battery according to an exemplary embodiment of the present invention.

Referring to the drawings, the secondary battery 10 includes an electrode assembly 12, a can 11 containing the electrode assembly 12 and an electrolyte, and a cap assembly 100 coupled to the can 11. do.

The electrode assembly 12 typically forms a wide plate shape of the positive electrode 13 and the negative electrode 15 to increase the capacitance, and then separates the separator 14 between the positive electrode 13 and the negative electrode 15 from each other. Laminated and sandwiched and wound into a spiral shape to form a so-called 'Jelly Roll'. The negative electrode 15 and the positive electrode 13 may be formed by coating carbon as the negative electrode active material and lithium cobalt as the positive electrode active material, respectively, on a current collector made of copper and aluminum foil. The separator 14 is made of polyethylene, polypropylene, or a copolymer of polyethylene and polypropylene. Separator 14 is formed to be wider than the positive electrode 13 and the negative electrode 15 is advantageous to prevent short circuit between the electrode plates. In the electrode assembly 12, positive and negative electrode tabs 16 and 17 connected to each electrode are drawn out. An insulating tape 18 is wound around the positive and negative electrode tabs 16 and 17 to prevent a short circuit between the electrode plates 13 and 15 at the boundary portion drawn out of the electrode assembly 12.

The can 11 is a metal container having a substantially rectangular parallelepiped shape in a rectangular secondary battery as shown, and formed by a processing method such as deep drawing. It is therefore possible for the can itself to act as a terminal. As the material for forming the can, aluminum or aluminum alloy, which is a lightweight conductive metal, is preferable. The can 11 becomes a container of the electrode assembly 12 and the electrolyte solution, and the upper portion opened to the electrode assembly 12 is sealed by the cap assembly 100.

The cap assembly 100 includes a cap plate 110, an electrode terminal 130, an insulating plate 140, and a terminal plate 150. The cap plate 110 has a terminal through hole 111 formed therein, and the electrode terminal 130 penetrates through the terminal through hole 111 with the gasket 120 positioned to insulate the cap plate 110 from the outer surface thereof. Is installed. An insulating plate 140 is provided on the lower surface of the cap plate 110, and a terminal plate 150 is provided on the lower surface of the insulating plate 140. The lower end of the electrode terminal 130 is coupled to the terminal plate 150.

The negative electrode 15 of the electrode assembly 12 is electrically connected to the electrode terminal 130 through the negative electrode tab 17 and the terminal plate 150. In the case of the positive electrode 13 of the electrode assembly 12, the positive electrode tab 16 is welded to the cap plate 110 or the can 11. An insulating case 190 may be further installed below the terminal plate 150. On the other hand, the battery may be designed by changing the polarity.

The cap plate 110 is formed with an electrolyte injection hole 112 for injecting an electrolyte into the can 11, and a sealing part 200 for sealing the electrolyte injection hole 112 after electrolyte injection is formed. . This sealing part 200 is as follows in more detail.

Referring to FIG. 2B, the sealing part 200 of the secondary battery according to the exemplary embodiment of the present invention includes a sealing material 210 and a core material 230.

The sealing member 210 is formed of a body portion 211 penetrating through the electrolyte injection hole and the body portion 211 integrally with the bottom portion in close contact with the bottom surface of the cap plate 110 of the outlet side outer periphery of the electrolyte injection hole ( 212), and the sealing member 210 is made of a material capable of plastic deformation (eg, aluminum).

In addition, the core material 230 is surrounded by the sealant 210 while being coupled to at least a portion of the sealant 210, and is made of a harder material than the sealant 210.

Looking at the method of sealing the electrolyte injection hole with reference to Figure 2a and 2b,

First, prepare a sealing material surrounding the core material. In this case, the core material has a rod or rod shape, and the diameter of the lower end portion is greater than the diameter of the upper portion of the lower end portion, so that the core material can be combined with the sealing material surrounding the core material. That is, in order to pull up the sealing material together later when pulling the core material upward, the core material needs to be coupled with at least a part of the sealing material. The core material enables the core material to be structurally combined with the sealing material. . However, the content of the present invention is not limited to the above structural combinations. For example, bonding by soldering or adhesives is also possible.

Referring to FIG. 2B, the core material 230 is positioned along the central axis of the sealing part 200. In FIG. 2A, the bottom portion 212 shown in FIG. 2B is formed by pulling the core material embedded in the center of the sealing material upwards (arrow direction) so that the sealing material is plastically deformed, wherein the core material 230 defines the central axis of the sealing portion 200. This is because the bottom portion 212 is formed to be symmetrical with respect to the central axis of the sealing portion 200 so that effective sealing is possible.

Then, the sealing material is inserted into the electrolyte injection hole.

Then, pull the heart upwards. Accordingly, the portion of the sealing material combined with the core moves upwards together to form the bottom portion 212 of FIG. 2B while the sealing material is plastically deformed to seal the electrolyte injection hole.

At this time, the sealing property can be improved by pressing down the portion (upper surface of the sealing material) exposed to the outside of the battery in the sealing material in Figure 2a. That is, the entire sealing material is prevented from being pulled upward together with the core material, and the sealing volume can be reduced, so that the sealing part 200 as shown in FIG. 2B can be formed.

Referring to FIG. 2B, the lower end of the core member 230 is positioned below the lower surface of the cap plate 110. That is, if the cap plate 110 pulls up to the top when the core is pulled upward in FIG. 2A, the bottom surface of the bottom portion 212 may have a shape that is not flat but concave upward as shown in FIG. 2B. In some cases, this may rather deteriorate the sealing of the electrolyte injection hole, so it should be noted that the core material is excessively pulled upward.

Next, as shown in FIG. 2B, the portion protruding to the outside of the sealing member 211 around the core 230 may be cut. The core material 230 played a role of inducing plastic deformation of the sealing material, and a part protruding above the cap plate 110 serves as a terminal for drawing electricity generated from the electrode assembly to the outside or preventing deformation of the resin. If it does not play a separate role, such as the role of the holder no longer contributes to the structure of the battery occupies only the unnecessary space, it can be cut and proceed to the core pack process or battery pack process.

On the other hand, the contact member is located in at least some section between the sealing material and the cap plate can further enhance the sealing of the electrolyte injection hole, which will be described later.

Referring to FIG. 3B, the sealing part 200 ′ of the secondary battery according to another exemplary embodiment of the present invention includes a sealing material 210 ′ and a core material 230 ′.

The sealing material 210 'is formed integrally with the body portion 211' penetrating the electrolyte injection hole and the body portion 211 'and is in close contact with the upper surface of the cap plate 110 of the inlet side outer periphery of the electrolyte injection hole. And a bottom portion 212 'formed integrally with the body portion 211' and the body portion 211 'and adhered to the bottom surface of the cap plate 110 of the outlet side outer circumference of the electrolyte injection hole. The seal member 210 'is made of a material capable of plastic deformation (for example, aluminum).

In addition, the core material 230 ′ is surrounded by the sealing material 210 ′ while being coupled to at least a portion of the sealing material 210 ′, and is made of a harder material than the sealing material 210 ′.

In comparison with the embodiment shown in Fig. 2B, the sealing material 210 'of this embodiment further includes a head 213'. As shown in FIG. 3B, the head portion 213 ′ comes into close contact with the upper surface of the cap plate 110 of the electrolyte injection hole inlet side outer periphery, thereby further strengthening the sealing of the electrolyte injection hole.

Looking at the shape of the sealing portion 200 'of Figure 3b, it can be seen that the I-shaped. As shown in FIG. 3A, the shape until the sealing material is prepared and inserted into the electrolyte injection hole is T-shaped, and the shape of the sealing portion 200 'after pulling the core material upward is I-shaped. The same applies to the shape of the seal 200 ″ in FIG. 4B.

Since the method of sealing the electrolyte injection hole is the same as the embodiment shown in Figures 2a and 2b, description thereof will be omitted.

Referring to FIG. 4B, in comparison with the embodiment of FIG. 3B, the contact member 250 is the same except that the contact member 250 is positioned in at least some sections between the sealant 210 ″ and the cap plate 110. Only the member 250 will be described.

In FIG. 4B, the contact member 250 is positioned at the outer periphery of the inlet and outlet sides of the electrolyte injection hole. When the sealing member is inserted in FIG. 4A, the adhesive members are inserted together to be positioned at the outer periphery of the inlet and outlet sides of the electrolyte injection hole, and the core member 230 ″ is pulled upward to seal the I-shaped seal 200 as illustrated in FIG. 4B. Form ").

The adhesion member 250 is to further strengthen the sealing of the electrolyte injection hole, the adhesion member 250 is polypropylene (PP), Tedra fluoroethylene- perfluoro alkyl vinyl ether copolymer (PFA), polytetra It may be made of a material that is any one selected from fluoroethylene (PTFE), Tedra fluoroethylene-hexafluoropropylene copolymer (FEP), or a combination thereof.

By forming the sealing portion 200 ″, the sealing of the electrolyte injection hole can be ensured even if the welding and curing agent coating process that is conventionally performed after the electrolyte injection hole sealing is omitted. It is not intended to exclude welding and / or curing agent coating processes after forming.

According to the present invention, the sealing property of the electrolyte injection hole is improved, and further, even if the welding and curing agent coating process performed after the electrolyte injection hole sealing is omitted, the electrolyte injection hole can be sealed.

Although the present invention has been described with reference to the illustrated embodiments, it is merely exemplary, and the present invention may cover various modifications and equivalent other embodiments that can be made by those skilled in the art. I will understand that.

Claims (23)

delete delete delete delete delete delete delete delete delete delete delete In the method for sealing the electrolyte injection hole of the cap plate which is a passage for injecting the electrolyte into the battery case, Preparing a sealing material of a plastically deformable material surrounding the core material; Inserting the sealing material into the electrolyte injection hole; And And pulling the core material to the outside so that the sealing material is plastically deformed to seal the electrolyte injection hole. The core material is made of a rod or rod formed with a diameter greater than that of the lower portion of the lower end portion, In the step of preparing the sealing material, the lower end of the core material is coupled to the sealing material, In the step of pulling the core material to the outside, the sealing material portion combined with the lower end of the core material moves upwards together to form a bottom portion in close contact with the bottom of the cap plate of the outer peripheral edge of the outlet side of the electrolyte injection hole while the sealing material is plastically deformed. An electrolyte injection hole sealing method of a battery, characterized in that. 13. The method of claim 12, After the step of pulling the core material to the outside, the electrolyte injection hole sealing method of the battery characterized in that it comprises the step of cutting the portion protruding outward than the sealing material around the center of the core material. delete 13. The method of claim 12, When the sealing material is inserted into the electrolyte injection hole, the electrolyte injection hole sealing method of the battery, characterized in that the contact member is located in at least a portion between the portion of the case where the electrolyte injection hole is formed and the sealing material. 13. The method of claim 12, When the core material is pulled to the outside, the electrolyte injection hole sealing method of the battery, characterized in that for pressing the portion of the sealing material exposed to the outside of the battery in the direction opposite to the direction of pulling the core material to the outside. The method according to any one of claims 12 to 13 and 15 to 16, The core material is a sealing method of the electrolyte injection hole of the battery, characterized in that made of a harder material than the sealing material. 13. The method of claim 12, The core material is an electrolyte injection hole sealing method of a battery, characterized in that located along the central axis of the electrolyte injection hole. 13. The method of claim 12, And a lower end portion of the core member is positioned below the bottom surface of the cap plate. 13. The method of claim 12, The sealing material, the electrolyte injection of the battery, characterized in that it comprises a body portion penetrating the electrolyte injection hole and the body portion integrally in close contact with the cap plate upper surface of the outer periphery of the inlet side of the electrolyte injection hole Ball sealing method. 21. The method of claim 20, The sealing material is an electrolyte injection hole sealing method of the battery, characterized in that the I-shaped. 21. The method of claim 20, The electrolyte injection hole sealing method of the battery, characterized in that the contact member is located on the outer periphery of the inlet and outlet side of the electrolyte injection hole. The method of claim 15 or 22, The contact member is selected from polypropylene (PP), tedra fluoroethylene-perfluoro alkyl vinyl ether copolymer (PFA), polytetra fluorethylene (PTFE), tedra fluoroethylene-hexafluoropropylene copolymer (FEP) The electrolyte injection hole sealing method of the battery, characterized in that made of a material of any one or a combination thereof.

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