阅读说明：本技术 防止电池壳体被腐蚀的用于圆柱形电池的衬垫及包括该衬垫的圆柱形电池 (Gasket for cylindrical battery preventing battery case from being corroded and cylindrical battery comprising same ) 是由 皇甫光洙 于 2020-04-07 设计创作，主要内容包括：公开了一种用于圆柱形电池的衬垫及包括该衬垫的圆柱形电池,该衬垫包括：配置为支撑盖组件的支撑部；和从支撑部的外侧向上延伸的压接部,其中在压接部的末端的外侧形成有向下延伸的延伸部。(Disclosed are a gasket for a cylindrical battery and a cylindrical battery including the same, the gasket including: a support portion configured to support the cap assembly; and a crimping part extending upward from an outer side of the supporting part, wherein an extending part extending downward is formed at an outer side of a tip of the crimping part.)

1. A gasket for a cylindrical battery configured to have a ring shape, the gasket for a cylindrical battery comprising:

a support part constituting a lower portion of the gasket, the support part configured to support a cap assembly; and

a crimping part constituting a side part of the packing, the crimping part extending upward from an outer side of the supporting part, wherein

An extension part extending downwards is formed at the outer side of the end of the crimping part.

2. The gasket for a cylindrical battery according to claim 1, wherein a protrusion structure is formed on an upper surface of the support part.

3. The gasket for a cylindrical battery according to claim 1, wherein an outermost radius of the extension part is smaller than an inner radius of the crimp part in a state where the crimp part is deformed to assemble the cylindrical battery.

4. The gasket for a cylindrical battery according to claim 1, further comprising a lower end portion formed at an inner side of the support portion so as to extend downward.

5. A cylindrical battery comprising:

a cylindrical battery case in which the electrode assembly is accommodated;

a cap assembly mounted in the open portion of the cylindrical battery case; and

the gasket for cylindrical batteries according to any one of claims 1 to 4, which is interposed between the cylindrical battery case and the cap assembly, wherein

An upper portion of the cylindrical battery case wraps the outer circumference of the cap assembly and is bent toward a central portion of the cylindrical battery case, and

the end of the upper part of the cylindrical battery case is received in a receiving part defined by the extension part of the gasket for the cylindrical battery.

6. The cylindrical battery according to claim 5, wherein a distance between the crimping part and a tip of the extending part is equal to or less than a thickness of the upper part of the battery case.

7. The cylindrical battery according to claim 5, wherein the receiving part has a structure inclined downward in a direction toward the center of the battery case in a state in which the cylindrical battery is coupled.

8. The cylindrical battery according to claim 5, wherein the extension is formed in a shape in which the thickness of the extension is gradually reduced from a starting end of the extension to a terminal end of the extension.

9. The cylindrical battery according to claim 5, wherein

An uncoated portion from which an anti-corrosion layer is removed is formed on at least a portion of the upper part of the battery case, and

the extension has a structure configured to wrap around the uncoated portion.

10. The cylindrical battery according to claim 5, wherein

The cap assembly includes a top cap and a safety vent,

a recess is formed in a lower surface of the safety vent, and

the recess is provided to engage with a protrusion structure formed on an upper surface of the support part of the gasket for a cylindrical battery, so that the safety vent and the gasket for a cylindrical battery are coupled to each other.

11. The cylindrical battery according to claim 5, wherein

The battery case includes a beading portion configured to support the cap assembly and the gasket for the cylindrical battery, and

a lower end portion formed inside the support portion of the gasket for a cylindrical battery so as to extend downward is located between the beading portion and the cap assembly.

12. The cylindrical battery according to claim 11, wherein

The cap assembly further includes a current interrupt device coupled to a lower surface of the safety vent, and

the lower end portion of the gasket includes a structure extending in a direction toward a center of the gasket so as to support the current interruptive device.

13. A battery pack comprising the cylindrical battery according to claim 5.

Technical Field

This application claims the benefit of priority from korean patent application No. 2019-0053969, filed on 8/5/2019, the entire disclosure of which is incorporated herein by reference.

The present invention relates to a gasket for a cylindrical battery configured to prevent a battery case from being corroded and a cylindrical battery including the same, and more particularly, to a gasket for a cylindrical battery having a structure configured to wrap an upper portion of a cylindrical battery case from which an anti-corrosion layer is removed to prevent the battery case from being corroded and a cylindrical battery including the same.

Background

With the growing trend of mobile devices including mobile phones, headsets, and vacuum cleaners, most of these mobile devices, which are wired products, have also been manufactured as wireless products. A lithium secondary battery having high energy density, high operating voltage, and excellent life characteristics has been widely used as an energy source for wireless products.

The lithium secondary battery is classified into: a cylindrical secondary battery configured such that an electrode assembly is mounted in a cylindrical metal can, a prismatic secondary battery configured such that an electrode assembly is mounted in a prismatic metal can, or a pouch-shaped secondary battery configured such that an electrode assembly is mounted in a pouch case made of an aluminum laminate sheet. Among them, the cylindrical secondary battery has advantages in that the cylindrical secondary battery has a relatively large capacity and is structurally stable.

In a cylindrical secondary battery, in order to prevent a battery case from being corroded, a steel plate made of an iron (Fe) material, coated with nickel or the like, is used as the battery case, and after a forming process such as deep drawing, a process of cutting a cylindrical battery case portion from the steel plate as a base material is performed.

At this time, the cut surface of the battery case is a portion where the nickel coating layer is not formed, and thus a section of the iron material is exposed. The cutting surface is exposed even after a crimping process, whereby the cutting surface may be rusted or corroded.

Patent document 1 relates to a secondary battery including: a battery case configured to receive the electrode assembly without providing a crimping portion, and a cap assembly coupled to an open end of the battery case.

In patent document 1, a cover having a structure configured to wrap an upper portion of an edge of a cap assembly and an upper portion of a battery case is used, wherein the cover can be used to prevent exposure of the battery case, however, in order to fix the cover, a structure in which the upper portion of the battery case is deformed is used. When the upper portion of the battery case is deformed as described above, an additional process is required, and thus the battery manufacturing process becomes complicated.

Patent document 2 relates to a cylindrical battery employing an evaporable corrosion inhibitor comprising a polymer resin and a sodium nitrate-based material, and a corrosion-resistant gasket comprising a base resin.

Patent document 2 discloses a method in which a material in an anticorrosive lining reacts with moisture to generate nitrogen oxide, and the nitrogen oxide oxidizes the surface of a cylindrical can, thereby preventing a crimping portion from being corroded even under high-temperature and high-humidity conditions.

Patent document 3 relates to a cylindrical battery including a gasket having: a first portion including an insertion recess into which an end portion of the cylindrical housing is inserted and fixed; and a second portion extending from the first portion to an interior of the case so as to support the cap assembly.

In patent document 3, a gasket having an insertion recess into which an end portion of a battery case is inserted is used; however, the gasket is applied to a cylindrical battery that is not formed with the crimping part and the crimping part, and has a structure in which the tip of the battery case is inserted into the first part before the crimping part of the battery case is formed.

Therefore, there is a high necessity for a gasket for a cylindrical secondary battery having a crimping structure, wherein the gasket is configured to have a structure in which: this structure can prevent the battery case from being corroded even in the case where the nickel coating layer is removed from the end of the upper portion of the battery case and thus the exposed portion is formed.

(Prior art document)

(patent document)

Korean patent application laid-open No. 2012-0047114 (2012.05.11)

Korean patent application laid-open No. 2018-0127938 (2018.11.30)

Korean patent application laid-open No. 1998-030967 (1998.07.25)

Disclosure of Invention

Technical problem

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a gasket for a cylindrical battery having a structure configured to wrap the end of a battery case from which an anti-corrosion coating is easily removed to prevent the battery case from being corroded, and a cylindrical battery including the same.

Technical scheme

In order to achieve the above object, the present invention may provide a gasket for a cylindrical battery configured to have a ring shape, the gasket for a cylindrical battery including: a support part constituting a lower portion of the gasket, the support part configured to support a cap assembly; and a crimping part constituting a side of the pad, the crimping part extending upward from an outer side of the supporting part, wherein an extension part extending downward is formed at an outer side of a tip of the crimping part.

A protrusion structure may be formed on an upper surface of the support part.

The outermost radius of the extension part may be smaller than an inner radius of the crimp part in a state where the crimp part is deformed to assemble the cylindrical battery.

The gasket for a cylindrical battery may further include a lower end portion formed at an inner side of the support portion so as to extend downward.

Further, the present invention may provide a cylindrical battery including the gasket for a cylindrical battery, wherein the cylindrical battery includes: a cylindrical battery case in which the electrode assembly is accommodated; a cap assembly mounted in the open portion of the cylindrical battery case; and the gasket for a cylindrical battery interposed between the cylindrical battery case and the cap assembly, and wherein an upper portion of the cylindrical battery case wraps an outer circumference of the cap assembly and is bent toward a central portion of the cylindrical battery case, and a tip of the upper portion of the cylindrical battery case is received in a receiving part defined by the extension of the gasket for a cylindrical battery.

A distance between the crimping part and the tip of the extending part may be equal to or less than a thickness of the upper part of the battery case.

The receiving part may have a structure inclined downward in a direction toward the center of the battery case in a state where the cylindrical batteries are coupled.

The extension may be formed in a shape in which a thickness of the extension is gradually reduced from a start end of the extension to a tip end of the extension.

An uncoated portion from which an anti-corrosion layer is removed may be formed on at least a portion of the upper portion of the battery case, and the extension may have a structure configured to wrap the uncoated portion.

The cap assembly may include a top cap and a safety vent, a recess may be formed in a lower surface of the safety vent, and the recess may be provided to engage with a protrusion structure formed on an upper surface of the support part of the gasket for a cylindrical battery, so that the safety vent and the gasket for a cylindrical battery are coupled to each other.

The battery case may include a beading portion configured to support the cap assembly and the gasket for a cylindrical battery, and a lower end portion formed inside the supporting portion of the gasket for a cylindrical battery so as to extend downward may be located between the beading portion and the cap assembly.

The cap assembly may further include a current interrupt device coupled to a lower surface of the safety vent, and the lower end portion of the gasket may include a structure extending in a direction toward a center of the gasket so as to support the current interrupt device.

The present invention provides a battery pack including the cylindrical battery.

Drawings

Fig. 1 is an upper sectional view of a cylindrical secondary battery including a gasket according to the present invention before assembly.

Fig. 2 is a partially cut-away perspective view of a gasket according to the present invention.

Fig. 3 is an upper sectional view of a cylindrical secondary battery including a gasket according to the present invention after assembly.

Fig. 4 is an enlarged cross-sectional view of an extension of a gasket according to the present invention.

Detailed Description

Now, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily carry out the present invention. However, in describing in detail the operation principle of the preferred embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may obscure the subject matter of the present invention.

Further, the same reference numerals will be used throughout the drawings to designate portions that perform similar functions or operations. In the case where one portion is referred to as being connected to another portion in the present application, not only may the one portion be directly connected to the other portion, but also the one portion may be indirectly connected to the other portion via another portion. In addition, the inclusion of a certain element does not mean that other elements are excluded, but means that other elements may be further included unless otherwise specified.

In the present invention, in order to prevent the battery case of the cylindrical battery from being corroded, the structure of the gasket, which is the sealing member of the cylindrical battery, is deformed.

Generally, in order to prevent the cylindrical battery from being corroded, a steel sheet having a nickel coating layer formed on the surface thereof is used. The steel plate is deep-drawn to be formed into the shape of the battery case, and the formed portion is cut from the steel plate, thereby serving as the battery case.

At this time, the cut surface of the battery case is a portion where the nickel coating layer is not formed, and the cut surface may be rusted or corroded when exposed to air.

Accordingly, the present invention solves the above-mentioned problems by applying a new structure to a gasket used as a sealing member of a cylindrical battery. That is, the structure of the gasket is changed such that the gasket wraps the end of the upper portion of the battery case where the nickel coating layer is not formed.

In connection with this, fig. 1 is an upper sectional view of a cylindrical secondary battery including a gasket according to the present invention before assembly, and fig. 2 is a partially cut-away perspective view of the gasket according to the present invention.

Referring to fig. 1 and 2, the cap assembly 110 includes: a top cover 101, the top cover 101 having a protrusion structure serving as a positive electrode terminal; a safety vent 102, the safety vent 102 being located at the lower part of the top cover 101 and wrapping the outer circumference of the top cover 101; a current interrupt device 104 provided to contact a lower surface of the safety vent 102; and a CID pad 103, the CID pad 103 being configured to block contact between the current interrupt device 104 and the outer periphery of the safety vent 102.

The gasket for securing insulation between the cap assembly 110 and the battery case and sealing the battery case includes: a support part 121 configured to support the cover assembly, a crimp part 122 extending upward from an outer side of the support part 121, and an extension part 123 formed at an outer side of a tip of the crimp part 122 so as to extend downward.

The gasket further includes a lower end portion 124 formed inside the support portion 121 so as to extend downward, the lower end portion 124 including a structure further extending in a direction toward the center of the gasket so as to support the current interruptive device 104 and the CID gasket 103, the CID gasket 103 being configured to ensure insulation between the current interruptive device 104 and the safety vent 102.

The safety vent 102 has a recess 105 formed in a lower surface thereof, and a protrusion structure 125 is formed on an upper surface of the support part 121. The protrusion structure 125 may be inserted into the recess 105 so that the cap assembly including the safety vent may be stably coupled to the gasket, and the cap assembly may be fixed in place by the coupling therebetween.

Although the protrusion structures 125 are shown as two rows of annular structures, one or more protrusions spaced apart from each other may be formed continuously or discontinuously.

The extension part 123 defines a receiving part 126 configured to receive the terminal end of the battery case, and the extension part 123 is formed in a shape in which the thickness of the extension part 123 is gradually reduced from the start end 123a of the extension part to the terminal end 123b of the extension part, whereby the terminal end 123b of the extension part can more closely contact the battery case in a state in which the battery case is received in the receiving part 126.

Fig. 3 is an upper sectional view of a cylindrical secondary battery including a gasket according to the present invention after assembly, and fig. 4 is an enlarged sectional view of an extension of the gasket according to the present invention. Referring to fig. 3 and 4, there is shown a state in which the gasket and cap assembly 110 of fig. 1 and 2 is received in the battery case 200 of the cylindrical battery of fig. 3 to be sealed.

The upper part 201 of the battery case 200 is bent toward the central portion of the battery case through the crimping process and thus deformed into a structure configured to wrap the upper portion of the gasket and the upper surface of the outer circumference of the cap assembly, and the tip 202 of the upper part 201 of the deformed battery case 200 is received in the receiving part 126 of the gasket defined by the extension 123.

The length of the extension 123 is not particularly limited, but is a length sufficient to wrap the uncoated portion 201a formed at the upper portion of the battery case from which the corrosion prevention layer is removed. The non-coating portion 201a from which the corrosion prevention layer is removed is not formed at the end but is pushed from the upper portion of the battery case toward the outer or inner lower end portion due to the deformation of metal during the manufacture of the battery case. Heretofore, it has been considered that the intended design in which the uncoated portion is formed at the tip portion to prevent corrosion by contact between the tip portion and the gasket is such that continuous corrosion cannot be prevented at the uncoated portion pushed from the upper portion of the case toward the outer lower end portion or the inner lower end portion.

In particular, in the case where the battery is exposed to the outside, it is very important to prevent the battery from being corroded in consideration of condensation of steam due to a change in atmospheric temperature, contamination due to rain or snow, and the like. However, corrosion continues to occur due to the lack of recognition of this slight difference, and this problem remains unsolved. In contrast, the present invention can solve this problem by recognizing the fact that the uncoated portion is pushed.

However, in consideration of the fact that the extension 123 is located at the outer surface of the upper portion of the battery case, in order to prevent the overall length of the cylindrical battery from increasing, the extension may be formed to have a length of the maximum upper protrusion that does not extend to the crimping portion of the battery case.

Specifically, referring to fig. 4, the outermost radius a1 of the extension part may be formed to be smaller than the inner radius a2 of the crimp part.

Further, in order to prevent an increase in the total length of the cylindrical battery due to the addition of the extension portion, a structure is applied in which the thickness of the extension portion is reduced in a direction toward the end thereof.

When the gasket and the cap assembly 110 are in close contact with each other in a state where the crimp part 122 and the crimp part 203 are formed after the cap assembly 110 and the gasket are accommodated in the battery case 200, the protrusion structure 125 of the gasket is inserted into the recess 105 of the safety vent, whereby a structure capable of achieving stable fixation therebetween can be provided.

The battery case 200 is formed in a structure having a crimping portion 203 in which the lower end 124 of the gasket is located between the crimping portion 203 and the cap assembly 110, thereby blocking contact therebetween.

Preferably, the extension 123 is located at the outer surface of the battery case 200 so as to be in close contact with the battery case 200. A distance b1 between the crimp part 122 of the gasket and the tip of the extension part 123 may be equal to a thickness b2 of the upper portion of the battery case.

Alternatively, the gasket may be made of an elastic member, wherein a distance b1 between the crimp part 122 and the tip of the extension part 123 may be less than a thickness b2 of the upper part of the battery case. When the upper portion of the battery case 200 is inserted into the receiving part 126, the receiving part 126 may be deformed to be expanded such that the upper portion of the battery case is seated therein.

In addition, the receiving part 126 may have a structure inclined downward in a direction toward the center of the battery case. Therefore, even in the case where a force to return the upper portion of the battery case to the state before the upper portion of the battery case is crimped is applied to the crimped upper portion of the battery case due to the backrush phenomenon, the exposure of the uncoated portion can be minimized, and as an additional effect, the sealing of the battery case can be stably maintained.

Further, the present invention may provide a battery pack configured such that cylindrical batteries each having the above-described structure are connected in series and/or parallel with each other, and may provide a battery pack having high output, high capacity, and improved safety.

Those skilled in the art to which the invention pertains will appreciate that various applications and modifications can be made based on the above description without departing from the scope of the invention.

(reference number description)

101: top cover

102: safety vent

103: CID gasket

104: current interruption device

105: concave part

110: cap assembly

121: supporting part

122: crimping part

123: extension part

123 a: the beginning of the extension

123 b: end of the extension part

124: lower end part

125: protrusion structure

126: accommodating part

200: battery case

201: upper part of battery case

201 a: uncoated part

202: terminal of upper part of battery case

203: curled edge part

a 1: outermost radius of extension

a 2: inside radius of crimping part

b 1: distance between crimping part and tip of extension part

b 2: the thickness of the upper portion of the battery case.

Industrial applicability

As apparent from the above description, the present invention has a structure in which a receiving part configured to receive the end of the upper part of the battery case is formed in the extension part of the gasket, whereby corrosion of an iron (Fe) exposed part, which is a nickel (Ni) plating layer rupture part, inevitably occurring at the end of the upper part of the battery case during the manufacturing process of the battery case can be prevented.

Further, the extension portion of the gasket is formed to have a structure inclined downward in a direction toward the center of the battery case, whereby the distal end of the upper portion of the battery case can be prevented from being separated from the receiving portion of the gasket due to the rewinding of the crimp portion.

Further, the length of the extended portion of the gasket is limited to a predetermined range, whereby the overall size of the cylindrical secondary battery can be prevented from increasing even in the case where the extended portion is formed.