KR20220074583A - Button type rechargeable battery - Google Patents

Abstract

The present invention relates to a secondary battery, and the button-type secondary battery according to the present invention includes an electrode assembly in which a first electrode, a separator, and a second electrode are alternately stacked and wound; a can including a body having an opening in which the electrode assembly is accommodated, and a cover covering the opening of the body and having a terminal hole; an insulating tape attached to the inner surface of the can to insulate the can and the electrode assembly; a first electrode terminal having one side inserted into the terminal hole and connected to the first electrode; and an insulating sealing part for insulating and sealing between the cover and the first electrode terminal, wherein the cover and the body are welded to be fixed and sealed between the cover and the body.

Description

Button type secondary battery {BUTTON TYPE RECHARGEABLE BATTERY}

The present invention relates to a button-type secondary battery.

Secondary batteries, unlike primary batteries, can be recharged, and have been widely researched and developed in recent years due to their small size and large capacity. As technology development and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly increasing.

The secondary battery is classified into a button cell, a cylindrical cell, a prismatic cell, and a pouch-type cell according to the shape of the battery case. In a secondary battery, an electrode assembly mounted inside a battery case is a charging/discharging power generating element having a stacked structure of an electrode and a separator.

In a conventional button-type secondary battery, an electrode assembly is accommodated in a battery case, and the battery case is composed of a cover and a body. In this case, an insulator was positioned between the electrode assembly and the can, and was provided on the upper and lower surfaces of the electrode assembly.

However, the insulator is positioned on the upper and lower surfaces of the electrode assembly to prevent the electrode assembly from being impregnated with the electrolyte, thereby reducing injectability, and due to the contraction and expansion of the electrode assembly, the insulator is separated from the electrode assembly and there is a high flow risk. come. If the insulator flows, there is a high risk of a short circuit and a serious threat to battery stability.

Korean Patent Publication No. 10-2016-0010121

One aspect of the present invention is to provide a button-type secondary battery capable of improving electrolyte injectability and flow risk.

A button-type secondary battery according to an embodiment of the present invention includes an electrode assembly in which a first electrode, a separator, and a second electrode are alternately stacked and wound; a can including a body having an opening in which the electrode assembly is accommodated, and a cover covering the opening of the body and having a terminal hole; an insulating tape attached to the inner surface of the can to insulate the can and the electrode assembly; a first electrode terminal having one side inserted into the terminal hole and connected to the first electrode; and an insulating sealing part that insulates and seals between the cover and the first electrode terminal, wherein the cover and the body are welded to be fixed and sealed between the cover and the body.

The battery pack according to an embodiment of the present invention may include a button-type secondary battery according to an embodiment of the present invention.

According to the present invention, by attaching the insulating tape to the can side between the electrode assembly and the can, the injectability of the electrolyte can be improved and the risk of flow of the insulating tape can be significantly reduced. In addition, there is an effect that the insulating tape is attached in the form of a film tape so that it is not scratched even when the electrode end touches and a short circuit can be reliably prevented.

1 is a cross-sectional view showing a button-type secondary battery according to an embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of region C in FIG. 1 .
3 is a cross-sectional view taken along line A-A' in FIG. 1 .
4 is a cross-sectional view taken along the line B-B' in FIG. 1 .
5 is a cross-sectional view showing a button-type secondary battery according to another embodiment of the present invention.

The objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings and preferred embodiments. In the present specification, in adding reference numbers to the components of each drawing, it should be noted that only the same components are given the same number as possible even though they are indicated on different drawings. In addition, the present invention may be embodied in several different forms and is not limited to the embodiments described herein. And, in describing the present invention, detailed descriptions of related known technologies that may unnecessarily obscure the gist of the present invention will be omitted.

Button type secondary battery according to an embodiment

1 is a cross-sectional view showing a button-type secondary battery according to an embodiment of the present invention.

Referring to FIG. 1 , a button-type secondary battery 100 according to an embodiment of the present invention includes an electrode assembly 110 including a first electrode 111 , a separator 114 , and a second electrode 112 , and a cover. A can 140 (Can) accommodating the electrode assembly 110 therein, including the 120 and the body 130, insulating tapes 160 and 170 insulating between the can 140 and the electrode assembly 110; It includes a first electrode terminal 150 connected to the first electrode 111 , and an insulating sealing part S that insulates between the first electrode terminal 150 and the cover 120 .

Hereinafter, a button-type secondary battery according to an embodiment of the present invention will be described in more detail.

The button-type secondary battery 100 may be a secondary battery having a larger diameter than a height. The electrode assembly 110 may be contained in the can 140 of the button type secondary battery.

The electrode assembly 110 is a power generating element capable of charging and discharging, and the electrode 113 and the separator 114 are assembled to form a structure in which they are alternately stacked. Here, the electrode assembly 110 may have a wound shape.

The electrode 113 may include a first electrode 111 and a second electrode 112 . In addition, the separator 114 separates the first electrode 111 and the second electrode 112 to electrically insulate them. Here, the first electrode 111 and the second electrode 112 may be formed in a sheet shape, wound together with the separator 114 , and formed in a jelly roll shape. In this case, the electrode assembly 110 may be wound in a cylindrical shape, for example. That is, the winding shaft may be disposed in a form perpendicular to the ground.

The width (or diameter) of the electrode assembly 110 may be formed to be greater than the height.

The first electrode 111 may be formed of, for example, an anode, and the second electrode 112 may be formed of, for example, a cathode. Here, the first electrode 111 is not necessarily made of an anode and the second electrode 112 is not necessarily made of a cathode, and the first electrode 111 is made of a cathode, and the second electrode 112 is Of course, it may be formed in both directions.

The positive electrode may include a positive electrode current collector (not shown) and a positive electrode active material (not shown) applied to the positive electrode current collector. The positive electrode current collector may be made of, for example, an aluminum foil, and the positive electrode active material is, for example, lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium nickel cobalt manganese oxide, lithium iron phosphate. , or a compound or mixture containing at least one of them.

The negative electrode may include a negative electrode current collector (not shown) and a negative electrode active material (not shown) applied to the negative electrode current collector. The negative electrode current collector may be made of, for example, a foil made of a copper (Cu) or nickel (Ni) material. The anode active material may be made of, for example, natural graphite, artificial graphite, lithium metal, lithium alloy, carbon, petroleum coke, activated carbon, graphite, silicon compound, tin compound, titanium compound, or an alloy thereof. In this case, the negative active material may further include, for example, non-graphite-based SiO (silica, silica) or SiC (silicon carbide, silicon carbide).

The separator 114 is made of an insulating material and is alternately stacked with the first electrode 111 and the second electrode 112 . Here, the separator 114 may be positioned between the first electrode 111 and the second electrode 112 and on the outer surfaces of the first electrode 111 and the second electrode 112 . In this case, the separator 114 may also be positioned at the outermost side in the width direction W when the electrode assembly 110 is wound.

In addition, the separator 114 may be made of a flexible material. In this case, the separator 114 may be formed of, for example, a polyolefin-based resin film such as polyethylene or polypropylene having microporosity.

FIG. 2 is an enlarged cross-sectional view of region C in FIG. 1 . 1 and 2 , the can 140 has a receiving part formed therein to accommodate the electrode assembly 110 therein.

In addition, the can 140 has an opening that is opened to one side, a body 130 having a receiving part in which the electrode assembly 110 is accommodated, and covers the opening of the body 130 , and a terminal hole 121 is formed therein. It may include a formed cover 120 .

In addition, since the cover 120 and the body 130 are welded, the space between the cover 120 and the body 130 may be fixed and sealed.

In this case, the welding may be seam welding. Here, the seam welding may in particular be a laser seam welding. The seam welding is a method of continuously performing spot welding, using an electrode having a rotating roller shape instead of an electrode of the spot welding, and rotating the electrode while supplying a welding current. Such seam welding is used for continuous work such as containers and long pipes that require airtightness. In particular, when the roller for seam welding rotates, part of the supply current flows to the welded portion first and part flows between the roller electrodes, so a large supply current is required. In this way, by welding the cover 120 and the body 130 through the seam welding, the sealing between the cover 120 and the body 130 can be coupled.

In addition, the cover 120 is formed in a plate shape, and the body 130 may be formed in a cup shape having a vertical cross section of, for example, a “C” shape.

In addition, the can 140 may be formed in a cylindrical shape, for example.

And, between the outer peripheral surface of the cover 120 and the inner peripheral surface of the body 130 may be welded.

In addition, the cover 120 is seated on the seating protrusion 131 formed on the inner wall of the body 130 , thereby increasing the bondability between the cover 120 and the body 130 .

The first electrode terminal 150 may include an insertion part 151 provided on one side and inserted into the terminal hole 121 and a locking part 152 provided on the other side and having a larger diameter than the terminal hole 121 . can

The insertion part 151 may be inserted into the terminal hole 121 to be connected to the first electrode 111 .

The locking part 152 has a larger diameter than the terminal hole 121 and is located outside the cover 120 to prevent the first electrode terminal 150 from being separated from the inside of the can 140 .

The insulating sealing part S may insulate and seal between the cover 120 and the first electrode terminal 150 .

Here, the insulating sealing part S may include an electrically insulating and heat-resistant material.

At this time, the insulating sealing part (S) includes a gasket (S1) made of an electrically insulating and heat-resistant material, and an adhesive means (142) for bonding the gasket (S1) to the cover 120 and the first electrode terminal 150. can

FIG. 3 is a cross-sectional view taken along line A-A' in FIG. 1 , and FIG. 4 is a cross-sectional view taken along line B-B' in FIG. 1 .

1, 3, and 4 , the insulating tapes 160 and 170 include an insulating material, are positioned between the can 140 and the electrode assembly 110 , and are positioned between the can 140 and the electrode assembly 110 . insulate Here, the insulating tapes 160 and 170 may be attached to the inner surface of the can 140 . In this case, the insulating tapes 160 and 170 may be attached to the upper and lower surfaces of the can 140 from the inner surface.

Meanwhile, the insulating tapes 160 and 170 may include a first layer in contact with the can 140 and a second layer facing the electrode assembly.

The first layer may include an adhesive material, and the second layer may include an insulating polymer film having abrasion resistance. In this case, the insulating polymer film may be, for example, polyimide.

In addition, the insulating tapes 160 and 170 may include an upper insulating tape 160 positioned on the upper surface of the inner surface of the can 140 and a lower insulating tape 170 positioned on the lower surface of the inner surface of the can 140 .

The upper insulating tape 160 may be attached to the cover 120 , and the lower insulating tape 170 may be attached to the body 130 .

In addition, the upper insulating tape 160 and the lower insulating tape 170 may be formed in the form of a disk having a hollow center portion. In this case, the upper insulating tape 160 and the lower insulating tape 170 may each have an upper central hole 161 and a lower central hole 171 penetrating through the center in the vertical direction.

Accordingly, the upper insulating tape 160 and the lower insulating tape 170 each including an insulating polymer film are attached to the cover 120 and the body 130 , and the electrode assembly 110 , the cover 120 , and the body 130 . ) can be insulated, and the electrolyte solution is more easily impregnated into the electrode assembly 110 to improve electrolyte injection properties, and the upper insulation tape 160 and the lower insulation tape according to the contraction and expansion of the electrode assembly 110 ( 170) can significantly reduce the flow risk.

In addition, in the case of a button cell, there is a problem in that the end of the electrode 113 comes into contact with the upper surface of the cover 120 or the lower surface of the body 130 to cause friction, but the present invention provides an upper insulating tape comprising an insulating polymer film, respectively. 160 and the lower insulating tape 170 are attached to the cover 120 and the body 130, and the insulating material is coated on the cover 120 and the body 130, so that the coating material may be partially scratched off. can prevent Accordingly, in the present invention, since the insulating tapes 160 and 170 are attached in the form of a film tape, the electrode 113 is not scratched even when the end thereof is touched, and short circuit can be reliably prevented.

In other words, assuming, for example, a case in which a coating material is coated for insulation, the thickness may not always be uniformly coated during the coating process. There may be a thinly coated portion and there may be a thickly coated portion. However, when the end of the electrode touches the thinly coated part, it is very easily scratched (a kind of scratch), and the scratched part may break the insulation. In this case, a short may occur. In contrast, in the present invention, since the insulating tapes 160 and 170 in the form of a film are attached, the same thickness can be implemented on the entire inner surface of the can 140 . Accordingly, even if the end of the electrode is in contact with a portion, insulation can be well maintained on all portions of the upper inner surface or the lower inner surface of the can 140 .

On the other hand, the button-type secondary battery 100 according to an embodiment of the present invention may further include a center pin (P) positioned at the center of the winding of the electrode assembly (110).

In this case, the width of the upper central hole 161 and the lower central hole of the upper insulating tape 160 and the lower insulating tape 170 may be formed to be smaller than the width of the center pin P.

The center pin P may be formed in a cylindrical shape, and the upper central hole 161 and the lower central hole of the upper insulating tape 160 and the lower insulating tape 170 may be formed in a circular shape.

The diameter d2 of the upper central hole 161 and the diameter d3 of the lower central hole 171 of the upper insulating tape 160 and the lower insulating tape 170 are greater than the inner peripheral diameter d1 of the center pin P. can be made small.

Accordingly, the end of the center pin P is attached to the cover 120 and the body 130 through the upper central hole 161 and the lower central hole 171 of the upper insulating tape 160 and the lower insulating tape 170 . contact can be prevented.

In addition, it is possible to prevent the electrode located at the center of the electrode assembly, that is, located at a position in contact with the center pin P, from contacting the cover 120 or the body 130 . This can prevent a situation in which a short circuit may occur in advance.

On the other hand, the button-type secondary battery 100 according to an embodiment of the present invention has a first electrode lead 180 electrically connecting between the first electrode 111 and the first electrode terminal 150 , and a second electrode 112 . and a second electrode lead 190 electrically connecting the body 130 to each other.

The first electrode lead 180 is connected to the first electrode terminal 150 through the upper central hole 161 of the upper insulating tape 160 , and the second electrode lead 190 is the lower part of the lower insulating tape 170 . It may be connected to the body 130 through the central hole 171 .

At this time, the first electrode lead 180 is welded to the first electrode terminal 150 through the upper central hole 161 of the upper insulating tape 160 , and the second electrode lead 190 is the lower insulating tape 170 . It can be welded to the body 130 through the lower central hole 171 of the.

Here, an extension 132 extending in the direction of the lower central hole 171 of the lower insulating tape 170 from the bottom surface of the body 130 is further formed, so that the second electrode lead 190 and the body 130 are formed. It can facilitate welding and connection.

Button type secondary battery according to another embodiment

Hereinafter, a button-type secondary battery according to another embodiment will be described.

5 is a cross-sectional view showing a button-type secondary battery according to another embodiment of the present invention.

Referring to FIG. 5 , the button-type secondary battery 200 according to another embodiment of the present invention includes an electrode assembly 110 including a first electrode 111 , a separator 114 , and a second electrode 112 , and a cover. A can 140 (Can) accommodating the electrode assembly 110 therein, including the 120 and the body 130, insulating tapes 260 and 270 insulating between the can 140 and the electrode assembly 110; It includes a first electrode terminal 150 connected to the first electrode 111 , and an insulating sealing part S that insulates between the first electrode terminal 150 and the cover 120 .

The secondary battery 200 according to another embodiment of the present invention has a difference in that the insulating tapes 260 and 270 are formed of a single layer compared to the secondary battery according to the above-described embodiment. Accordingly, in the present embodiment, content overlapping with the embodiment will be briefly described, and differences will be mainly described.

In the secondary battery 200 according to another embodiment of the present invention, the insulating tapes 260 and 270 include an insulating material, and are positioned between the can 140 and the electrode assembly 110 to provide the can 140 and the electrode assembly 110 . Insulate between Here, the insulating tapes 260 and 270 may be heat-sealed to the inner surface of the can 140 . In this case, the insulating tapes 260 and 270 may be heat-sealed from the inner surface of the can 140 to the upper and lower surfaces.

In addition, the insulating tapes 260 and 270 may be formed of one layer in contact with the can 140 . In this case, the insulating tapes 260 and 270 may include an insulating polymer film having abrasion resistance. Here, the insulating polymer film may be, for example, polyimide.

In addition, the insulating tapes 260 and 270 may include an upper insulating tape 260 positioned on the upper surface of the inner surface of the can 140 and a lower insulating tape 270 positioned on the lower surface of the inner surface of the can 140 .

The upper insulating tape 260 may be heat-sealed to the cover 120 , and the lower insulating tape 270 may be heat-sealed to the body 130 .

In addition, the upper insulating tape 260 and the lower insulating tape 270 may be formed in the form of a disk having a hollow central portion. In this case, the upper insulating tape 260 and the lower insulating tape 270 may each have an upper central hole and a lower central hole penetrating through the center in the vertical direction.

Accordingly, the upper insulating tape 260 and the lower insulating tape 270 each including an insulating polymer film are heat-sealed to the cover 120 and the body 130, and the electrode assembly 110, the cover 120, and the body ( 130), the electrode assembly 110 is more easily impregnated with the electrolyte to improve the electrolyte injection property, and the upper insulation tape 260 and the lower insulation tape according to the contraction and expansion of the electrode assembly 110 (270) can reduce the flow risk.

In addition, in the case of a button cell, there is a problem that the end of the electrode touches the upper surface of the cover 120 or the lower surface of the body 130 and causes friction, but the present invention provides an upper insulating tape 260 including an insulating polymer film, respectively. And the lower insulating tape 270 is heat-sealed to the cover 120 and the body 130, so that the insulating material is coated on the cover 120 and the body 130 to prevent the problem that the coating material may be partially scratched off can do. Accordingly, in the present invention, since the insulating tapes 260 and 270 are attached in the form of a film tape, they are not scratched even when the electrode ends touch, and short circuits can be reliably prevented.

In addition, the insulating tapes 260 and 270 are heat-sealed to the inside of the can 140 to more firmly maintain a fixing force between the insulating tapes 260 and 270 and the can 140 .

Although the present invention has been described in detail through specific examples, it is intended to describe the present invention in detail, and the present invention is not limited thereto. It will be said that various implementations are possible by those of ordinary skill in the art within the technical spirit of the present invention.

In addition, the specific protection scope of the invention will become clear by the appended claims.

100,200: button type secondary battery
110: electrode assembly
111: first electrode
112: second electrode
113: electrode
114: separator
120: cover
121: terminal hole
130: body
131: seating jaw
132: extension
140: can
150: first electrode terminal
151: insertion part
152: catch
160,260: upper insulating tape
161: upper central hall
170,270: lower insulating tape
180: first electrode lead
190: second electrode lead
P: center pin
S: Insulation sealing part

Claims (13)

an electrode assembly in which a first electrode, a separator, and a second electrode are alternately stacked and wound;
a can including a body having an opening formed therein to accommodate the electrode assembly, and a cover covering the opening of the body and having a terminal hole;
an insulating tape attached to the inner surface of the can to insulate the can and the electrode assembly;
a first electrode terminal having one side inserted into the terminal hole and connected to the first electrode; and
and an insulating sealing part for insulating and sealing between the cover and the first electrode terminal,
The cover and the body are welded to form a button-type secondary battery that is fixed and sealed between the cover and the body. The method according to claim 1,
the insulating tape
an upper insulating tape positioned on the upper surface of the inner surface of the can; and
A button-type secondary battery including a lower insulating tape positioned on a lower surface of the inner surface of the can. 3. The method according to claim 2,
The upper insulating tape is attached to the cover, and the lower insulating tape is attached to the body button type secondary battery. 4. The method according to claim 3,
The upper insulating tape and the lower insulating tape have an upper central hole and a lower central hole penetrating vertically through a central portion of the button type secondary battery, respectively. 5. The method according to claim 4,
Further comprising a center pin located in the winding center of the electrode assembly,
The width of the upper central hole and the lower central hole of the upper insulating tape and the lower insulating tape is smaller than the width of the center pin. 6. The method of claim 5,
The center pin is formed in a cylindrical shape,
The upper central hole and the lower central hole of the upper insulating tape and the lower insulating tape are formed in a circular shape,
Diameters of the upper and lower central holes of the upper insulating tape and the lower insulating tape are smaller than the inner peripheral diameter of the center pin. 5. The method according to claim 4,
a first electrode lead electrically connecting the first electrode and the first electrode terminal; and
Further comprising a second electrode lead electrically connecting the second electrode and the body,
the first electrode lead is connected to the first electrode terminal through an upper central hole of the upper insulating tape;
The second electrode lead is a button-type secondary battery connected to the body through a lower central hole of the lower insulating tape. 3. The method according to claim 2,
The can is formed in a cylindrical shape,
The upper insulating tape and the lower insulating tape are button-type secondary batteries formed in a disk shape. The method according to claim 1,
The width of the electrode assembly is formed to be greater than the height of the button type secondary battery. The method according to claim 1,
The insulating tape includes a first layer in contact with the can and a second layer facing the electrode assembly,
The first layer includes an adhesive material,
The second layer is a button type secondary battery comprising an insulating polymer film having abrasion resistance. The method according to claim 1,
The insulating tape consists of one layer,
The insulating tape is a button-type secondary battery in which an insulating polymer film having abrasion resistance is heat-sealed to a can. The method according to claim 1,
The welding is a seam welding Button type secondary battery. A battery pack comprising the button-type secondary battery according to any one of claims 1 to 12.

Images