WO2019203450A1

WO2019203450A1 - Secondary battery

Info

Publication number: WO2019203450A1
Application number: PCT/KR2019/003015
Authority: WO
Inventors: 허치훈; 곽승호; 김범래; 김진환; 김춘숙; 박소담; 양승훈; 오용호; 이병곤
Original assignee: 삼성에스디아이 주식회사
Priority date: 2018-04-17
Filing date: 2019-03-15
Publication date: 2019-10-24
Also published as: KR102538094B1; CN111989801A; KR20190121069A

Abstract

A secondary battery (rechargeable battery) according to one embodiment of the present invention comprises: a case for accommodating an electrode assembly for performing charging and discharging and an electrolyte solution; a cap plate sealing the opening of the case and having an electrolyte solution injection hole; and a sealing cap for sealing the electrolyte solution injection hole, wherein the sealing cap comprises a first coupling part for sealing the inner part of the electrolyte solution injection hole, and a second coupling part connected to the first coupling part so as to seal the outer part of the electrolyte solution injection hole.

Description

Secondary battery

The present disclosure relates to a secondary battery, and more particularly, to a secondary battery for sealing an electrolyte injection hole provided in a cap plate with a sealing stopper.

Secondary batteries, unlike primary batteries, are batteries that repeatedly perform charging and discharging. Small capacity rechargeable batteries are used in portable electronic devices such as mobile phones, notebook computers and camcorders. Large-capacity and high-density secondary batteries are used to power motors or store energy for hybrid and electric vehicles.

For example, the secondary battery includes an electrode assembly for charging and discharging, a case accommodating the electrode assembly, a cap plate coupled to the opening of the case and having an electrolyte injection hole, and a sealing stopper for sealing the electrolyte injection hole.

The manufacturing process of the secondary battery includes an electrode process, an assembly process and a chemical conversion process. The assembly process includes initial charging (precharging) immediately after assembling the secondary battery, and the initial charging generates gas inside the secondary battery.

The chemical conversion process is a process that proceeds to have a function of the assembled secondary battery as a battery. The chemical conversion process is a charging process in which a secondary battery is sealed after removing a gas generated during initial charging.

That is, the chemical conversion process converts chemical energy into electrochemical energy by supplying electrical energy to a secondary battery. In the chemical conversion process, the active materials of the positive electrode and the negative electrode change from a low energy state to a high energy state.

During the chemical conversion process, gas is also generated inside the secondary battery. For example, when the electrolyte is a carbonate-based organic solvent, a portion of the electrolyte is decomposed during the initial filling process, and gas is generated and discharged before the chemical conversion process. Since the secondary battery is sealed after the initial charging and before the chemical conversion process, the gas generated by the chemical conversion process increases the internal pressure of the secondary battery.

When gas generated in the chemical conversion process remains inside the secondary battery, the quality of the secondary battery is degraded. Therefore, it is necessary to remove the gas remaining in the secondary battery after the chemical conversion process.

One aspect of the present invention is to provide a secondary battery that discharges and removes the gas generated in the chemical conversion process to the electrolyte injection hole, and then seals the electrolyte injection hole with a sealing stopper.

According to an exemplary embodiment of the present invention, a secondary battery includes a case accommodating an electrode assembly and an electrolyte solution that charges and discharges, a cap plate that seals an opening of the case and includes an electrolyte injection hole, and a sealing stopper that seals the electrolyte injection hole. It includes, The sealing stopper includes a first coupling portion for sealing the inner portion of the electrolyte injection port, and a second coupling portion connected to the first coupling portion, sealing the outer portion of the electrolyte injection hole.

The electrolyte injection hole according to an embodiment of the present invention includes a first injection portion formed as a first inner circumferential surface, and a second injection portion connected to the first injection portion and formed as a second inner circumferential surface larger than the first inner circumferential surface. Can be.

The first injection unit according to an embodiment of the present invention may be formed as a cylindrical through-hole of the first inner circumferential surface, the second injection portion may be formed as an expandable through-hole gradually extending the second inner circumferential surface.

According to an embodiment of the present invention, the first coupling part is formed of a cylinder corresponding to the cylindrical through hole, and the second coupling part is connected to the first coupling part and the cylindrical part corresponding to the first injection part and the Connected to the cylinder portion may include a cone portion corresponding to the second injection portion.

The second coupling part according to an embodiment of the present invention may be buried in the second injection part to form the same plane as the outer surface of the cap plate.

The sealing plug according to an embodiment of the present invention may further include a fixing part connected to the first coupling part and fixed to an inner portion of the first injection part.

An inner surface around the electrolyte injection hole according to an embodiment of the present invention may form one plane with an inner surface of the cap plate.

The inner surface around the electrolyte injection hole according to an embodiment of the present invention may form a protrusion protruding into the case from the inner surface of the cap plate.

According to an embodiment of the present invention, the first injection unit may define the first inner circumferential surface as a first cylindrical through hole, and the second injection unit may define the second inner circumferential surface as a second cylindrical through hole larger than the first cylindrical through hole. Can be.

The sealing stopper according to an embodiment of the present invention may be formed of PolyEthylene (PE), PerFluoroAlkoxy (PFA) or PolyTraFluoroEthylene (PTFE).

The secondary battery electrolyte injection hole sealing stopper according to an embodiment of the present invention is sealed to the electrolyte injection hole of the secondary battery, and is connected to the first coupling portion for sealing the inner portion of the electrolyte injection hole, and the first coupling portion, And a second engagement portion sealing the outer portion of the first injection portion.

According to an embodiment of the present invention, after the initial charging, the chemical conversion process is carried out with the sealing plug completely removed from the electrolyte inlet, and after the chemical conversion process (that is, after the gas generated during the chemical conversion process is removed by the electrolyte inlet) The electrolyte injection opening can be sealed with a sealing stopper. Therefore, the quality of the secondary battery may be improved because the gas generated during the chemical conversion process may discharge gas remaining in the secondary battery.

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

FIG. 2 is another cross-sectional view along the line II-II of FIG. 1.

FIG. 3 is a cross-sectional view illustrating a state in which a sealing stopper is temporarily assembled to an electrolyte injection hole provided in the cap plate of FIG. 2 (after the initial charging and before the chemical conversion process).

FIG. 4 is a cross-sectional view of a state in which the sealing plug is temporarily taken out of the electrolyte injection hole and the gas is discharged to the electrolyte injection hole (or before assembling) in the chemical conversion process.

FIG. 5 is a cross-sectional view of a state in which a sealing stopper is completely assembled into an electrolyte injection hole after discharging the gas generated during the chemical conversion process as shown in FIG. 4.

FIG. 6 is a cross-sectional view illustrating a state in which a sealing stopper is temporarily assembled into an electrolyte injection hole of a secondary battery according to a second embodiment of the present invention (after initial charge and before chemical conversion).

FIG. 7 is a cross-sectional view of a state in which the sealing stopper is temporarily withdrawn from the electrolyte injection hole and the gas is discharged to the electrolyte injection hole during the chemical conversion process, and then the sealing plug is completely assembled into the electrolyte injection hole.

FIG. 8 is a cross-sectional view illustrating a state in which a sealing stopper is temporarily assembled into an electrolyte injection hole of a secondary battery according to a third embodiment of the present invention (after initial charge and before chemical conversion).

FIG. 9 is a cross-sectional view of a state in which the sealing stopper is temporarily taken out from the electrolyte injection hole and the gas is discharged to the electrolyte injection hole during the chemical conversion step, and then the sealing plug is completely assembled into the electrolyte injection hole.

FIG. 10 is a cross-sectional view of a state in which a gas is discharged (or before assembling) to a electrolyte injection hole by temporarily drawing a sealing stopper from an electrolyte injection hole during a chemical forming process of a secondary battery according to a third exemplary embodiment of the present invention.

FIG. 11 is a cross-sectional view of a state in which a sealing stopper is completely assembled into an electrolyte injection hole after the chemical conversion process of FIG.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like elements throughout the specification.

1 is a perspective view of a rechargeable battery according to a first exemplary embodiment of the present invention, and FIG. 2 is another cross-sectional view taken along line II-II of FIG. 1.

1 and 2, the secondary battery 1 includes an electrode assembly 10 for charging and discharging a current, a case 15 containing the electrode assembly 10, and a cap coupled to an opening of the case 15. The plate 20 and the cap plate 20 may include a sealing stopper 27 for sealing the electrolyte injection hole 29 provided.

The secondary battery 1 may further include electrode terminals (negative and positive electrode terminals) 21 and 22 and an overcharge safety device (OSD) 40 installed on the cap plate 20.

For example, the electrode assembly 10 arranges the cathode 11 and the anode 12 on both sides of the separator 13, which is an electrical insulation material, and jelly the cathode 11, the separator 13, and the anode 12. It can be formed by rolling in a roll state. Although not shown in the drawings, the electrode assembly may be formed in a stack type in which a cathode, a separator, and a cathode are stacked.

Each of the negative electrode 11 and the positive electrode 12 includes

coating portions

11a and 12a coated with an active material on a current collector of a metal plate, and

plain portions

11b and 12b formed of a current collector exposed by not applying an active material. It may include.

The uncoated portion 11b of the cathode 11 may be formed at one end of the cathode 11 along the cathode 11 to be wound. The uncoated portion 12b of the positive electrode 12 may be formed at one end of the positive electrode 12 along the positive electrode 12 to be wound. The

plain portions

11b and 12b may be disposed at both ends of the electrode assembly 10, respectively.

For example, the case 15 is formed of an approximately rectangular parallelepiped to set a space for accommodating the electrode assembly 10 and the electrolyte therein, and forms an opening connecting the external and internal spaces on one surface of the rectangular parallelepiped. The opening allows insertion of the electrode assembly 10 into the case 15.

The cap plate 20 may be installed in the opening of the case 15 to seal the case 15. For example, the case 15 and the cap plate 20 may be made of aluminum and welded to each other.

In addition, the cap plate 20 may include a vent hole 24 and terminal holes H1 and H2. The vent hole 24 may be sealed with a vent plate 25 to discharge the internal pressure of the secondary battery 1 when a defect occurs.

When the internal pressure of the secondary battery 1 reaches a set pressure (excess pressure), the vent plate 25 may be cut to open the vent hole 24. The vent plate 25 may have a notch 25a for inducing an incision.

The cathode and

anode terminals

21 and 22 may be installed in the terminal holes H1 and H2 of the cap plate 20, respectively, and may be electrically connected to the electrode assembly 10. That is, the negative electrode and the

positive electrode terminals

21 and 22 may be electrically connected to the negative electrode and the

positive electrode

11 and 12 of the electrode assembly 10, respectively. Therefore, the electrode assembly 10 may be drawn out of the case 15 through the cathode and

anode terminals

21 and 22.

The cathode and

anode terminals

21 and 22 may form the same structure inside the cap plate 20. Therefore, the same structure will be described together, and different structures will be described separately because different structures are formed outside the cap plate 20.

The cathode and

anode terminals

21 and 22 are

rivet terminals

21a and 22a respectively installed in the terminal holes H1 and H2 of the cap plate 20 and the

rivet terminals

21a and 22a inside the cap plate 20.

Flanges

21b and 22b which are integrally formed in a wide range), and

plate terminals

21c and 22c which are disposed outside the cap plate 20 and are connected by riveting or welding to the

rivet terminals

21a and 22a. Can be.

The negative electrode and the

positive electrode gaskets

36 and 37 are respectively provided between the negative electrode and the

rivet terminals

21a and 22a of the

positive electrode terminals

21 and 22 and the inner surfaces of the terminal holes H1 and H2 of the cap plate 20, respectively. In addition, it is possible to seal and electrically insulate between the

rivet terminals

21a and 22a of the

anode terminals

21 and 22 and the cap plate 20.

The cathode and

anode gaskets

36 and 37 are further installed between the

flanges

21b and 22b and the inner surface of the cap plate 20 to further seal and electrically connect the

flanges

21b and 22b and the cap plate 20. Can be insulated. That is, the negative electrode and the

positive electrode gaskets

36 and 37 may prevent the leakage of the electrolyte through the terminal holes H1 and H2 by installing the negative and

positive terminals

21 and 22 in the cap plate 20. have.

The cathode and

anode lead tabs

51 and 52 electrically connect the cathode and

anode terminals

21 and 22 to the cathode and the

anode

11 and 12 of the electrode assembly 10, respectively. That is, the cathode and

anode lead tabs

51 and 52 are coupled to the lower ends of the

rivet terminals

21a and 22a to caulk the lower ends, so that the cathode and

anode lead tabs

51 and 52 are flanged 21b and 22b. While being supported at, it may be connected to the lower ends of the

rivet terminals

21a and 22a.

The negative electrode and the positive

electrode insulating members

61 and 62 are disposed between the negative electrode, the

positive lead tabs

51 and 52 and the cap plate 20, respectively, and the negative and positive

lead tabs

51 and 52 and the cap plate 20 are respectively provided. Can be electrically insulated.

The cathode and

anode insulation members

61 and 62 are coupled to the cap plate 20 on one side, and the anode,

anode lead tabs

51 and 52,

rivet terminals

21a and 22a and

flanges

21b and 22b on the other side. Since it encloses the structure of the connection can be stabilized.

Meanwhile, the overcharge safety device 40 will be described in relation to the plate terminal 21c of the negative electrode terminal 21, and the top plate 46 will be described in relation to the plate terminal 22c of the positive electrode terminal 22. do.

The overcharge safety device 40 on the side of the negative electrode terminal 21 may generate gas inside due to overcharging of the secondary battery 1, and thus may be configured to implement an external short circuit as the internal pressure increases.

For example, the overcharge safety device 40 may include a shorting tab 41 and a shorting member 43 spaced apart or shorted. The shorting tab 41 may be electrically connected to the rivet terminal 21a of the negative electrode terminal 21 and disposed outside the cap plate 20 through the insulating member 31.

The insulating member 31 may be installed between the shorting tab 41 and the cap plate 20 to electrically insulate the shorting tab 41 and the cap plate 20. That is, the cap plate 20 may maintain a state of being electrically insulated from the negative electrode terminal 21.

By combining the shorting tab 41 and the plate terminal 21c with the upper end of the rivet terminal 21a and caulking the upper end, the shorting tab 41 and the plate terminal 21c are coupled to the upper end of the rivet terminal 21a. Can be. Therefore, the shorting tab 41 and the plate terminal 21c may be fixed to the cap plate 20 with the insulating member 31 interposed therebetween.

The short circuit member 43 may be installed in the short circuit hole 42 formed in the cap plate 20. The shorting tab 41 may be connected to the negative electrode terminal 21 to extend along the outside of the shorting member 43.

Accordingly, the shorting tab 41 and the shorting member 43 correspond to each other in the shorting hole 42, maintain the spaced apart state (solid line state) to face each other, and increase the internal pressure of the secondary battery 1 due to overcharging. When the excess pressure is reached, a short circuit state (virtual line state) can be formed by the inversion of the short circuit member 43.

The top plate 46 on the side of the positive electrode terminal 22 may electrically connect the plate terminal 22c and the cap plate 20 of the positive electrode terminal 22. For example, the top plate 46 may be interposed between the plate terminal 22c and the cap plate 20 and penetrate the rivet terminal 22a.

Therefore, the top plate 46 and the plate terminal 22c are coupled to the top of the rivet terminal 22a to caulk the top, so that the top plate 46 and the plate terminal 22c are placed on the top of the rivet terminal 22a. Combined. The plate terminal 22c may be installed outside the cap plate 20 with the top plate 46 interposed therebetween.

Meanwhile, the anode gasket 37 may be further extended between the rivet terminal 22a and the top plate 46. That is, the anode gasket 37 may prevent the rivet terminal 22a and the top plate 46 from being electrically connected directly. That is, the rivet terminal 22a may be electrically connected to the top plate 46 through the plate terminal 22c.

Meanwhile, the electrolyte injection hole 29 provided in the cap plate 20 allows the cap plate 20 to be coupled to the case 15 and then injects the electrolyte into the case 15. After the electrolyte injection, the electrolyte injection opening 29 may be sealed with a sealing stopper 27.

Referring to FIG. 3, after the initial filling and before the chemical conversion process, the electrolyte injection hole 29 is treated as a preassembled sealed state with a sealing stopper 27.

That is, the sealing stopper 27 may be assembled to the electrolyte injection hole 29 after discharging the gas generated during the initial charging. The sealing stopper 27 may be coupled to be withdrawn from the electrolyte injection hole 29 in order to discharge the gas by opening the electrolyte injection hole 29 during the chemical conversion process. Temporary assembling of the sealing stopper 27 enables extraction from the electrolyte injection opening 29 after the initial filling and before the chemical conversion process.

Referring to FIG. 4, in the chemical conversion process, the electrolyte injection hole 29 may discharge and remove the gas generated during the chemical conversion process by temporarily opening the preassembled sealing stopper 27. The sealing stopper 27, which has been preassembled, may be reused or replaced with a new product after the chemical conversion process.

Referring to FIG. 5, after discharging and removing the gas generated during the chemical conversion process, the electrolyte injection hole 29 may be sealed again with a sealing plug 27 that has been preassembled. At this time, the sealing stopper 27 may be replaced with a new product.

As shown in FIGS. 3 to 5, after the initial charging, the sealing plug 27 is temporarily taken out of the electrolyte injection hole 29 to discharge the gas generated in the secondary battery 1 during the chemical conversion process. After that, since the electrolyte injection hole 29 is again sealed by the sealing stopper 27, gas may not remain in the secondary battery 1. That is, the quality of the secondary battery 1 can be improved.

3 to 5 again, the electrolyte injection hole 29 includes a first injection portion 291 formed as a first inner circumferential surface, and a second injection portion 292 formed as a second inner circumferential surface. It may include. The second injection unit 292 is connected to the first injection unit 291 and is formed larger than the first inner circumferential surface.

The sealing plug 27 may be formed to seal the first and

second injection parts

291 and 292 of the electrolyte injection hole 29. For example, the sealing stopper 27 may include a first coupling part 271 and a second coupling part 272.

The first coupling portion 271 seals the outer portion 91a of the first injection portion 291 after the initial charge and before the chemical conversion process (preliminary assembled state), and after the chemical conversion process, the inner side of the first injection portion 291. The portion 91b can be sealed. That is, after the chemical conversion process, when the sealing stopper 27 is completely assembled to the electrolyte injection hole 29, the first coupling part 271 may seal the inner portion 91b.

The second coupling portion 272 is connected to the first coupling portion 271, spaced apart from the second injection portion 292 after the initial charge, before the chemical conversion process (pre-assembled state), after the chemical conversion process, the second injection portion The outer portion 91a of the 292 and the first injection portion 291 can be sealed. That is, after the chemical conversion process, when the sealing stopper 27 is completely assembled to the electrolyte injection hole 29, the second coupling part 272 may seal the second injection part 292 and the outer part 91a. .

The boundary between the outer portion 91a and the inner portion 91b of the first injection portion 291 is a sealing plug 27 when the secondary battery 1 is handled from the electrolyte injection opening 29 before the chemical conversion process after the initial charge. It can be set in a range that can have a mutual fastening force not to be separated.

For example, the first injection portion 291 forms a first inner circumferential surface as a cylindrical through hole, and the second injection portion 292 gradually expands the second inner circumferential surface while going outward from the first injection portion 291. It can be formed as an expandable through hole.

The first coupling portion 271 may be formed as a cylinder corresponding to the cylindrical through hole. The second coupling portion 272 is connected to the first coupling portion 271 and is connected to the cylindrical portion 721 and the cylindrical portion 721 corresponding to the first injection portion 291, and the second injection portion 292 is connected to the first coupling portion 271. It may include a cone 722 corresponding to the.

The cone portion 722 may be embedded in the second injection portion 292 after the chemical conversion process to form the same plane as the outer surface of the cap plate 20. The cone portion 722 is pre-assembled sealing plug 27 to the electrolyte injection hole 29, or during the chemical conversion process, withdraw the gas by drawing or withdrawing the preassembled sealing plug 27 from the electrolyte injection port 29 When the sealing stopper 27 is completely assembled to the electrolyte injection opening 29, the handling of the sealing stopper 27 can be facilitated.

The first coupling portion 271 is coupled to the outer portion 91a of the first injection portion 291 when the sealing plug 27 is temporarily assembled to the electrolyte injection opening 29 after the initial charging and before the chemical conversion process. After the chemical conversion process, when the sealing stopper 27 is completely assembled to the electrolyte injection hole 29, the sealing plug 27 may be tightly coupled to the inner portion 91b of the first injection portion 291. Therefore, after the initial charging and before the chemical conversion process, the first coupling part 271 of the sealing stopper 27 may maintain the sealed state of the electrolyte injection hole 29.

The second coupling part 272 is spaced apart from the second injection part 292 when the sealing stopper 27 is temporarily assembled into the electrolyte injection hole 29 after the initial charging process, and after the chemical conversion process, the sealing stopper ( When the 27 is fully assembled to the electrolyte injection hole 29, the second injection portion 292 and the outer portion 91a of the first injection portion 291 may be coupled by interference fit. Therefore, after the chemical conversion process, the first and

second coupling parts

271 and 272 of the sealing stopper 27 may maintain the sealing state of the electrolyte injection hole 29.

The inner surface of the cap plate 20 around the electrolyte injection hole 29 may form one plane with the inner surface of the cap plate 20. In addition, the end portion 273 of the first coupling portion 271 may be formed smaller than the inner diameter of the first injection portion 291 to facilitate the insertion of the sealing member 27 into the electrolyte injection hole 29.

The end 273 may be disposed in a space between the case 15 and the cap plate 20 outside the first injection unit 291. Therefore, the coupling range of the first coupling portion 271 and the first injection portion 291 is secured to the maximum to ensure the coupling and sealing performance.

For example, the sealing stopper 27 may be formed of polyethylene (PolyEthylene, PE), PFA (PerFluoroAlkoxy), or polytetrafluoroethylene (PolyTtetraFluoroEthylene, PTFE), and may have a set elastic restoring force. That is, the sealing stopper 27 can maintain the elastic restoring force even after the chemical conversion process.

Therefore, after the initial charging and before the chemical conversion process, the sealing stopper 27 is temporarily assembled in the electrolyte injection hole 29, and during the chemical conversion process, the sealing stopper 27 is temporarily withdrawn from the electrolyte injection hole 29 and generated during the chemical conversion process. Allow internal gas to be exhausted. After the chemical conversion process, the sealing stopper 27 may be elastically completely assembled to the electrolyte injection hole 29 again. That is, the sealing performance between the sealing stopper 27 and the electrolyte injection hole 29 can be secured.

In addition, when the sealing stopper 27 is used as a temporary sealing stopper before the chemical conversion process after the initial filling, it can be manufactured by injection molding to lower the manufacturing cost. Since the sealing plug 27 is made larger than the electrolyte injection hole 29 with a set diameter, the sealing plug 27 may easily implement an interference fit for implementing the required sealing performance.

In addition, the sealing plug 27 may be applied to the operation of removing the internal gas of the secondary battery 1 or injecting the electrolyte solution, or may be repeatedly reused in products of the same specification.

In addition, the sealing stopper 27 may be added as an automated process during the production process of the secondary battery 1 because it enables the supply and process management in the process of assembling the secondary battery (1).

In addition, the sealing stopper 27 is temporarily withdrawn from the electrolyte injection opening 29 of the secondary battery 1 at the point where gas is finally generated to remove gas, thereby greatly improving the quality of the secondary battery 1. You can.

Hereinafter, various embodiments of the present invention will be described. Hereinafter, the description of the same configuration will be omitted, and different configurations will be described in comparison with the first embodiment and the previously described embodiment.

FIG. 6 is a cross-sectional view illustrating a state in which a sealing stopper is temporarily assembled to an electrolyte injection hole of a secondary battery according to a second embodiment of the present invention (after initial charging and before chemical conversion), and FIG. 7 is a state of FIG. It is sectional drawing of the state which fully sealed the sealing plug to the electrolyte injection hole after taking out a sealing stopper temporarily from the electrolyte injection hole, and discharging gas to an electrolyte injection hole.

6 and 7, in the cap plate 220 of the secondary battery 2 according to the second embodiment of the present invention, the inner surface around the electrolyte injection hole 48 is a case at the inner surface of the cap plate 20. Protrusions 48P that protrude into the interior of 15 can be formed.

Compared with the first injection portion 291 according to the first embodiment of the present invention forming the first inner circumferential surface as a cylindrical through hole, the cylindrical through hole of the first injection portion 481 of the second embodiment has a protrusion 48P. It can extend further through.

In the sealing plug 56, the first coupling portion 561 may be formed in a cylinder corresponding to the cylindrical through-hole further extending to the protrusion 48P. Compared with the first coupling portion 271 of the first embodiment of the present invention having a cylinder corresponding to the cylindrical through hole, the cylinder of the first coupling portion 561 of the second embodiment has a cylindrical through hole that extends. Correspondingly longer can be formed.

The second coupling part 562 is connected to the first coupling part 561 and the cylindrical part 621 and the cylindrical part 621 corresponding to the first injection part 481 further extended to the protrusion part 48P. And include a cone 622 corresponding to the second injection portion 482.

The cone portion 622 may be embedded in the second injection portion 482 after the chemical conversion process to form the same plane as the outer surface of the cap plate 220. The cone portion 622 is pre-assembled sealing plug 56 to the electrolyte injection hole 48, or during the chemical conversion process, withdraw the gas by drawing or withdrawing the preassembled sealing plug 56 from the electrolyte injection hole 48 When the sealing stopper 56 is completely assembled to the electrolyte injection opening 48, the handling of the sealing stopper 56 can be facilitated.

In the sealing stopper 56, the first coupling part 561 is an outer portion of the first injection part 481 when the sealing stopper 56 is preassembled to the electrolyte injection hole 48 after the initial charging and before the chemical conversion process. The inner portion 81b of the first injection portion 481 extending to the projection 48P when the sealing stopper 56 is fully assembled to the electrolyte injection hole 48 after the chemical conversion process, and after the chemical conversion process. Can be combined into an interference fit. Therefore, after the initial charging and before the chemical conversion process, the first coupling part 561 of the sealing stopper 56 may maintain the sealed state of the electrolyte injection hole 48.

In the second embodiment of the present invention, the inner portion 81b of the protrusion 48P and the first injection portion 481 has the same thickness as that of the cap plate 20 of the first embodiment. Compared to the first embodiment, the fastening and sealing performance with the first coupling part 561 may be further improved after the chemical conversion process.

The second coupling part 562 is spaced apart from the second injection part 482 when the sealing stopper 56 is temporarily assembled into the electrolyte injection hole 48 after the initial charging step, and after the chemical conversion step, the sealing stopper When the 56 is fully assembled to the electrolyte injection hole 48, it may be coupled to the second injection portion 482 and the outer portion 81a of the first injection portion 481 by interference fit. Therefore, after the chemical conversion process, the first and

second coupling parts

561 and 562 of the sealing stopper 56 may maintain the sealing state of the electrolyte injection hole 48.

In the first injection portion 481, the boundary between the outer portion 81a and the inner portion 81b is formed after the initial charging, and before the chemical conversion process, the sealing plug 56 is disposed from the electrolyte injection hole 38 when the secondary battery 2 is handled. It can be determined in a range that can have a mutual fastening force not to be separated.

Since the first injection portion 481 has a projection 48P and a cylindrical through hole extending therefrom, the boundary between the outer portion 81a and the inner portion 81b in the second embodiment is larger than the boundary in the first embodiment. It may be further moved inside the case 15.

FIG. 8 is a cross-sectional view illustrating a state in which a sealing stopper is temporarily assembled to an electrolyte injection hole of a secondary battery according to a third embodiment of the present invention (after initial charging and before chemical conversion), and FIG. 9 is a state of FIG. It is sectional drawing of the state which fully sealed the sealing plug to the electrolyte injection hole after taking out a sealing stopper temporarily from the electrolyte injection hole, and discharging gas to an electrolyte injection hole.

8 and 9, in the secondary battery 3 according to the third embodiment of the present invention, the first injection portion 551 of the electrolyte injection hole 55 forms a first inner circumferential surface as a first cylindrical through hole. The second injection portion 552 may form the second inner circumferential surface as a second cylindrical through hole larger than the first cylindrical through hole.

The inner surface of the cap plate 320 around the electrolyte injection hole 55 may form a protrusion 58P protruding from the inner surface of the cap plate 320 into the case 15. The first cylindrical through hole of the first injection portion 551 extends further through the protrusion 58P.

In the sealing plug 54, the first coupling portion 541 may be formed in a cylinder corresponding to the first cylindrical through-hole further extended to the protrusion (58P). The second coupling portion 542 is connected to the first coupling portion 541 and the first cylindrical portion 421 and the first cylindrical portion (421) corresponding to the first injection portion 551 further extended to the protrusion (58P) ( The second cylindrical portion 422 connected to the 421 and corresponding to the second injection portion 552 may be included.

The second cylindrical portion 422 may be embedded in the second injection portion 552 after the chemical conversion process to form the same plane as the outer surface of the cap plate 320. Accordingly, the second cylindrical portion 422 temporarily assembles the sealing stopper 54 to the electrolyte injection hole 55, or, during the chemical conversion process, draws out the gas by discharging or withdrawing the preassembled sealing stopper 54 from the electrolyte injection hole 55. After discharging, when the sealing stopper 54 is fully assembled to the electrolyte injection opening 55, the handling of the sealing stopper 54 can be facilitated.

In the sealing stopper 54, the first coupling part 541 is an outer portion of the first injection part 551 when the sealing stopper 54 is preassembled to the electrolyte injection hole 55 after the initial charging and before the chemical conversion process. The inner portion 51b of the first injection portion 551 extending to the protrusion 58P when the sealing stopper 54 is completely assembled to the electrolyte injection opening 55 after the chemical conversion process, and is combined with 51a). Can be combined into an interference fit. Therefore, after the initial charging and before the chemical conversion process, the first coupling part 541 of the sealing stopper 54 may maintain the sealing state of the electrolyte injection hole 55.

In the third embodiment of the present invention, the inner portion 51b of the protrusion 58P and the first injection portion 551 has the same thickness as the cap plate 320 is the cap plate 20 of the first embodiment. As compared with the first embodiment, the fastening and sealing performance with the first coupling part 571 may be further improved.

The second coupling part 542 is spaced apart from the second injection part 552 when the sealing stopper 54 is temporarily assembled into the electrolyte injection hole 55 after the initial charging step, and after the chemical conversion step, the sealing stopper ( When 54 is fully assembled to the electrolyte injection hole 55, the second injection portion 552 and the outer portion 51a of the first injection portion 551 may be coupled by interference fit. Therefore, after the chemical conversion process, the first and

second coupling parts

541 and 542 of the sealing stopper 54 may maintain the sealing state of the electrolyte injection hole 55.

FIG. 10 is a cross-sectional view of a state in which a gas stopper is temporarily taken out of an electrolyte inlet during discharge of a secondary battery according to a third embodiment of the present invention to discharge gas (or before assembling) from the electrolyte inlet, and FIG. It is sectional drawing of the state in which the sealing stopper was fully assembled in the electrolyte injection port after 10 chemical conversion processes (after the gas produced at the chemical conversion process was discharge | released).

10 and 11, in the secondary battery 4 according to the fourth exemplary embodiment of the present invention, the sealing plug 47 is connected to the first coupling part 271, so that the inside of the first injection part 291 is provided. It may further include a fixing portion 373 fixed to the portion (91b).

The fixing part 373 is deformed when the sealing stopper 47 is temporarily assembled to the electrolyte injection hole 29 after the initial charging process, and is coupled to the outer portion 91a of the first injection part 291 by force fitting. Can be.

After the chemical conversion process, when the sealing stopper 47 is completely assembled to the electrolyte injection hole 29, the fixing part 373 penetrates through the inner portion 91b of the first injection part 291 and the electrolyte injection hole 29. It is possible to fix the sealing plug 47 to the electrolyte injection hole 29 while being caught on the inner surface of the periphery.

Therefore, after the chemical conversion process, the fixing portion 373 of the sealing stopper 27 may maintain the sealing state of the electrolyte injection hole 29 more firmly.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the scope of the invention.

Description of the sign

1, 2, 3, 4: secondary battery 10: electrode assembly

11, 12: negative,

anode

11a, 12a: coating part

11b, 12b: Plain part 13: Separator

15:

case

20, 220, 320: cap plate

21, 22: um,

positive terminal

21a, 22a: rivet terminal

21b, 22b:

flange

21c, 22c: plate terminal

24: vent hole 25: vent plate

25a:

notches

27, 47, 54, 56: sealing stopper

29, 48, 55: electrolyte injection opening 31: insulating member

36, 37: negative, positive gasket 40: overcharge safety (OSD)

41: short circuit tab 43: short circuit member

46:

top plate

48P, 58P: protrusion

51, 52: negative,

positive lead tab

51a, 81a, 91a: outer part

51b, 81b, 91b: inner part 61, 62: negative and positive electrode insulating members

271, 561, 541:

first coupling portion

272, 562, 542: second coupling portion

273: ends 291, 481, 551: first injection portion

292, 482, 552: second injection portion 373: fixed portion

421 and 522: first and second cylinders 621 and 721: cylinders

622, 722: cone portion H1, H2: terminal hole

Claims

A case accommodating an electrode assembly and an electrolytic solution, each of which charge and discharge functions;

A cap plate sealing the opening of the case and having an electrolyte injection hole; And

Sealing plug for sealing the electrolyte injection hole

Including;

The sealing stopper,

A first coupling part sealing an inner portion of the electrolyte injection hole; And

A second coupling part connected to the first coupling part to seal an outer portion of the electrolyte injection hole;

Secondary battery comprising a.
The method of claim 1,

The electrolyte injection hole,

A first injection portion formed as a first inner circumferential surface; And

A second injection portion connected to the first injection portion and formed of a second inner circumference surface larger than the first inner circumference surface;

Secondary battery comprising a.
The method of claim 2,

The first injection portion forms the first inner peripheral surface as a cylindrical through hole,

The second injection unit is formed of an expansion through-hole that gradually extends the second inner circumferential surface.
The method of claim 3,

The first coupling portion,

It is formed of a cylinder corresponding to the cylindrical through hole,

The second coupling portion,

And a cylindrical portion connected to the first coupling portion and corresponding to the first injection portion and a cone portion connected to the cylindrical portion and corresponding to the second injection portion.
The method according to claim 2 or 4,

The second coupling portion,

The secondary battery is buried in the second injection portion to form the same plane as the outer surface of the cap plate.
The method of claim 1,

The sealing stopper,

And a fixing part connected to the first coupling part and fixed to an inner portion of the first injection part.
The method of claim 1,

The inner surface around the electrolyte inlet,

A secondary battery forming one plane with the inner surface of the cap plate.
The method of claim 2,

The inner surface around the electrolyte inlet,

A secondary battery forming a protrusion protruding into the case from the inner surface of the cap plate.
The method of claim 2,

The first injection portion forms the first inner peripheral surface as a first cylindrical through hole,

And the second injecting part forms the second inner circumferential surface as a second cylindrical through hole larger than the first cylindrical through hole.
The method of claim 1,

The sealing stopper is a secondary battery formed of PE (PolyEthylene), PFA (PerFluoroAlkoxy), or PTFE (PolyTtetraFluoroEthylene).
In the sealing stopper which seals the electrolyte injection hole of a secondary battery,

A first coupling part sealing an inner portion of the electrolyte injection hole; And

A second coupling part connected to the first coupling part to seal an outer portion of the first injection part;

Secondary battery electrolyte injection port sealing stopper comprising a.