WO2018056628A1

WO2018056628A1 - Secondary battery

Info

Publication number: WO2018056628A1
Application number: PCT/KR2017/010041
Authority: WO
Inventors: 이준용; 변상원; 안병규
Original assignee: 삼성에스디아이 주식회사
Priority date: 2016-09-20
Filing date: 2017-09-13
Publication date: 2018-03-29
Also published as: KR102249893B1; KR20180031444A

Abstract

A secondary battery according to an embodiment of the present invention comprises: an electrode assembly; a case accommodating the electrode assembly and having an opening formed at one side thereof; a cap plate which exposes an opening side end portion of the case and is coupled to the inside of the case to seal the electrode assembly; and a first insulating tape including a cap insulating portion covering an outer surface of the cap plate and an auxiliary insulating portion covering the opening side end portion of the case.

Description

Secondary battery

The present disclosure relates to a secondary battery, and more particularly, to a secondary battery including an insulating structure of a cap plate.

A high output secondary battery using a high energy density nonaqueous electrolyte has been developed. Low-capacity secondary batteries are mainly used for power supply of portable small electronic devices, and large-capacity secondary batteries in which a plurality of secondary batteries are connected in series are used for driving motors of electric or hybrid vehicles or power storage devices of renewable energy facilities. It is used for.

The secondary battery includes an electrode assembly, a case accommodating the electrode assembly, a cap plate coupled to the case to seal the electrode assembly and the electrolyte, and two terminals fixed to the cap plate.

The case and the cap plate are energized with any one of the positive electrode and the negative electrode constituting the electrode assembly, and the surface of the secondary battery except the electrode terminal is covered with an insulating material. The insulating material prevents the internal current of the secondary battery from leaking out and blocks the energization between neighboring secondary batteries when a plurality of secondary batteries are collected to form a battery module.

One aspect of the present invention is to provide a secondary battery that can improve the insulating properties by improving the insulating structure of the cap plate.

According to an embodiment of the present invention, a secondary battery includes an electrode assembly, a case accommodating the electrode assembly, an opening formed at one side thereof, a cap plate exposing an opening end of the case, and coupled to an inside of the case to seal the electrode assembly; And a first insulating tape including a cap insulating portion covering an outer surface of the cap plate and an auxiliary insulating portion covering an opening end of the case.

The secondary battery may further include a second insulating tape covering the outer surface of the case, and a portion of the auxiliary insulating portion may overlap the second insulating tape on the outer surface of the case.

The cap insulator may include four sides, and the auxiliary insulator may be divided into four and connected to one of four sides of the cap insulator. Each of the four auxiliary insulators can be folded into a depression from the cap insulator and attached to the opening side end of the case.

Each of the four auxiliary insulators has a first portion folded from the cap insulation and attached to the inner surface of the case, a second portion folded from the first portion and attached to the end surface of the case, and folded from the second portion. It may include a third portion attached to the outer surface of the.

The cap plate may be provided with first and second terminals, a sealing stopper, and a vent plate, and the cap insulation may form a plurality of openings that expose the first and second terminals, the sealing stopper, and the vent plate.

The first terminal and the second terminal may face each other along the first direction, and the four auxiliary insulation parts may face each other along the first direction with the first and second terminals interposed therebetween. And the remaining third and fourth auxiliary insulators.

The cap insulation portion may further include a protrusion part of which overlaps and is attached to each other and protrudes outward of the cap plate. The protrusion may be formed in parallel with a second direction crossing the first direction between the first auxiliary insulation and the first terminal and between the second auxiliary insulation and the second terminal. Each of the third and fourth auxiliary insulation portions may form cutouts on both sides of the protrusion.

According to the secondary battery of the present embodiment, by forming the auxiliary insulation on the first insulating tape, the insulation safety distance between the external metal frame and the secondary battery can be increased, and as a result, the insulation characteristics of the secondary battery can be improved.

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

FIG. 2 is an exploded perspective view of the secondary battery illustrated in FIG. 1.

3 is a cross-sectional view of a rechargeable battery cut along the line III-III of FIG. 1.

4 is a partially enlarged view of FIG. 3.

5 is a partial cross-sectional view of a battery module including a secondary battery of the first embodiment.

6 is a partial cross-sectional view of a battery module provided with a secondary battery of a comparative example.

7 is a partially enlarged cross-sectional view of a rechargeable battery according to a second exemplary embodiment of the present invention.

FIG. 8 is a perspective view of a first insulating tape of the secondary battery illustrated in FIG. 7.

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.

In addition, since the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of description, the present invention is not necessarily limited to the illustrated.

Throughout the specification, when a part is "connected" to another part, it includes not only "directly connected", but also "indirectly connected" between other members. In addition, when a part is said to "include" a certain component, this means that it may further include other components, except to exclude other components unless otherwise stated.

1 is a perspective view of a rechargeable battery according to a first exemplary embodiment of the present invention, FIG. 2 is an exploded perspective view of the rechargeable battery illustrated in FIG. 1, and FIG. 3 is a cutaway view taken along line III-III of FIG. 1. It is sectional drawing, and FIG. 4 is a partial enlarged view of FIG.

1 to 4, the secondary battery 100 of the first embodiment exposes an electrode assembly 110, a case 120 accommodating the electrode assembly 110, and an opening end of the case 120. And a cap plate 130 coupled to the inside of the case 120, a first insulating tape 140 covering the outer surface of the cap plate 130 and the opening side end of the case 120, and an outer surface of the case 120. It includes a second insulating tape 150 covering the.

The electrode assembly 110 includes a separator 113 and a first electrode 111 and a second electrode 112 positioned with the separator 113 interposed therebetween. One of the first electrode 111 and the second electrode 112 is an anode, and the other is a cathode. Each of the first and

second electrodes

111 and 112 includes a current collector made of a thin metal foil and an active material coated on the current collector surface.

Each of the first and

second electrodes

111 and 112 may be divided into

coating portions

111a and 112a coated with an active material on a current collector and non-coated

portions

111b and 112b without an active material coated on a current collector. The uncoated portion 111b of the first electrode 111 is positioned at one side of the electrode assembly 110, and the uncoated portion 112b of the second electrode 112 is positioned at the other side of the electrode assembly 110. The first and

second electrodes

111 and 112 and the separator 113 may be wound in the form of a jelly roll to form the electrode assembly 110.

The case 120 may have a substantially rectangular parallelepiped shape and form an opening at one side. The cap plate 130 exposes the open end of the case 120 and is fixed to the inside of the case 120 to seal the electrode assembly 110. The case 120 and the cap plate 130 may be made of metal such as aluminum, and the cap plate 130 may be fixed to the case 120 by welding.

The cap plate 130 is provided with an electrolyte injection hole 131 for injecting electrolyte into the sealed case 120, and after the electrolyte injection, the electrolyte injection hole 131 is sealed with a sealing stopper 132. A vent hole 133 is formed in the cap plate 130, and a vent plate 134 is installed in the vent hole 133. The vent plate 134 is broken when the internal pressure of the sealed case 120 is greater than or equal to the set pressure to open the vent hole 133. The vent plate 134 may have a notch 135 that induces an incision.

The first terminal 160 and the second terminal 170 are installed in the terminal holes H1 and H2 of the cap plate 130. The first and

second terminals

160 and 170 respectively extend laterally from the

rivet terminals

161 and 171 passing through the cap plate 130 and the

rivet terminals

161 and 171 inside the cap plate 130. The

flanges

162 and 172 and

plate terminals

163 and 173 disposed outside the cap plate 130 and connected to the

rivet terminals

161 and 171 by riveting or welding may be included.

The first and

second gaskets

164 and 174 are installed between the

rivet terminals

161 and 171 of the first and

second terminals

160 and 170 and the inner walls of the terminal holes H1 and H2, respectively. , 171 and the cap plate 130 are sealed and insulated. The first and

second gaskets

164 and 174 prevent leakage of the electrolyte through the terminal holes H1 and H2.

The first lead tab 181 is installed at one side of the electrode assembly 110 in the case 120, and the second lead tab 182 is installed at the other side of the electrode assembly 110. The first lead tab 181 is in contact with the uncoated portion 111b of the first electrode 111, and the second lead tab 182 is in contact with the uncoated portion 112b of the second electrode 112.

The first and

second lead tabs

181, 182 are coupled to the lower side of the

rivet terminals

161, 171 while contacting the

flanges

162, 172. The first and

second terminals

160 and 170 are energized with the first and

second electrodes

111 and 112 by the first and

second lead tabs

181 and 182, respectively.

The first and second

insulating members

191 and 192 are installed between the first and

second lead tabs

181 and 182 and the cap plate 130, respectively, to form the first and

second lead tabs

181 and 182. Insulate the cap plate 130. The first and second insulating

members

191 and 192 are in contact with the cap plate 130, the

flanges

162 and 172, the lower side of the

rivet terminals

161 and 171, and the upper side of the

lead tabs

181 and 182. Stabilize the connection structure.

The first and second

top plates

165 and 175 are positioned outside the cap plate 130. The first and second

top plates

165 and 175 are positioned between the

plate terminals

163 and 173 of the first and

second terminals

160 and 170 and the cap plate 130, respectively. The first top plate 165 may be formed of an insulating material to insulate the first terminal 160 from the cap plate 130, and the second top plate 175 may be formed of a conductive material to form the second terminal 170. And the cap plate 130 may be energized.

In the above-described secondary battery 100, the case 120 and the cap plate 130 are energized with the second electrode 112 and the second terminal 170.

Each of the first and second

insulating tapes

140 and 150 covers the outer surface of the cap plate 130 and the outer surface of the case 120 so that the current of the secondary battery 100 does not leak out, and the plurality of secondary batteries 100 ) To form a battery module (not shown) to block the energization between neighboring secondary batteries 100. The first and second

insulating tapes

140 and 150 are formed of an insulating layer and an adhesive layer applied to one surface of the insulating layer.

The first insulating tape 140 includes a cap insulating portion 141 covering an outer surface of the cap plate 130 and an auxiliary insulating portion 142 covering an opening side end portion of the case 120.

The auxiliary insulating part 142 covers a part of the inner surface 121 of the case 120, an entire end surface 122, and a part of the outer surface 123 at the opening side end of the case 120. The auxiliary insulator 142 is integrally connected to the cap insulator 141 and is folded in a depressed shape and attached to an opening end of the case 120.

The edge of the cap plate 130 is fixed to the inside of the case 120 at a distance from the end surface 122 of the case 120. That is, the end surface 122 of the case 120 is positioned higher than the outer surface of the cap plate 130 (located further from the electrode assembly 110). In this case, a portion of the inner surface 121 of the case 120 is exposed outside the secondary battery 100 along the opening side end portion of the case 120.

The cap insulation part 141 covers the outer surface of the cap plate 130 while exposing the first and

second terminals

160 and 170, the sealing plug 132, and the vent plate 134. That is, the cap insulation part 141 exposes the first opening 141a exposing the first and

second terminals

160 and 170, and the second opening 141b exposing the electrolyte injection hole 131 and the sealing plug 132. ) And a third opening 141c exposing the vent plate 134.

The case 120 includes four sides and one bottom surface. The cap plate 130 and the cap insulator 141 have four sides corresponding to four sides of the case 120, and the auxiliary insulator 142 is connected to one of the four sides of the cap insulator 141. Can be. For example, the first insulation tape 140 may include a cap insulation portion 141 positioned at the center and four auxiliary insulation portions 142 connected to four sides of the cap insulation portion 141.

Each of the four auxiliary insulation portions 142 is folded from the cap insulation portion 141 and is folded from the first portion 143 and the first portion 143 attached to the inner surface 121 of the case 120. And a second portion 144 attached to the end surface 122 of the third portion 144, and a third portion 145 folded into the second portion 144 and attached to the outer surface 123 of the case 120.

As one auxiliary insulator 142 is connected to each of the four sides of the cap insulator 141, the auxiliary insulator 142 is formed on a portion of the inner surface 121 of the case 120 at each of four sides of the case 120. The entire end surface 122 and a part of the outer surface 123 may be effectively covered.

The second insulating tape 150 surrounds all five sides of the case 120. The second insulating tape 150 may include, for example, a fourth portion 151 corresponding to one side of the case 120, and fifth and

sixth portions

152 and 153 connected to both sides of the fourth portion 151. And seventh and

eighth portions

154 and 155 connected to one side of the fifth and

sixth portions

152 and 153, and a ninth portion 156 connected to the lower side of the fourth portion 151, respectively. Can be.

After the fourth portion 151 of the second insulating tape 150 is attached to one side of the case 120, the fifth portion 152 and the sixth portion 153 are folded to the other two sides of the case 120. The seventh portion 154 and the eighth portion 155 may then be folded and attached to the other side of the case 120. A portion of the seventh portion 154 and the eighth portion 155 may overlap each other. In addition, the ninth portion 156 may be folded and attached to the bottom surface of the case 120.

The shape of the second insulating tape 150 and the attachment method to the case 120 are not limited to the above-described example and may be variously changed.

The third portion 145 of the first insulating tape 140 overlaps the second insulating tape 150. When the second insulating tape 150 is attached to the case 120 before the first insulating tape 140, the third portion 145 of the first insulating tape 140 covers the second insulating tape 150. (See Figure 4). On the contrary, when the first insulating tape 140 is attached to the cap plate 130 and the case 120 before the second insulating tape 150, the second insulating tape 150 is formed of the first insulating tape 140. Cover the third portion 145.

In the rechargeable battery 100 of the first exemplary embodiment, the entire surface of the rechargeable battery 100 except for the first and

second terminals

160 and 170, the sealing plug 132, and the vent plate 134 is formed of the first and second

insulating tapes

140 and 150. Covered with At this time, the first insulating tape 140 is folded in a recessed shape at the opening side end of the case 120 to cover a part of the inner surface 121 of the case 120, the entire end surface 122, and a part of the outer surface 123. 142).

The large capacity battery module is composed of a plurality of secondary batteries 100. For example, the plurality of secondary batteries 100 may be connected in parallel, and the plurality of secondary batteries 100 connected in parallel may be connected in series to form a large capacity battery module.

FIG. 5 is a partial cross-sectional view of a battery module including the secondary battery of the first embodiment, and FIG. 6 is a partial cross-sectional view of the battery module including the secondary battery of the comparative example. In FIG. 6, the secondary battery of the comparative example has the same configuration as that of the secondary battery of the first embodiment except that the first insulating tape 240 does not include an auxiliary insulating portion.

Referring to FIG. 5, the first insulating tape 140 may include an auxiliary insulating part 142, and the auxiliary insulating part 142 may have an inner surface 121 of the case 120 along an opening end of the case 120. It covers a part and the whole of the cross section 122 and a part of the outer surface 123. The second insulating tape 150 surrounds the entire outer surface of the case 120. The outer metal frame 200 of the battery module is located outside the side surface of the case 120 of the secondary battery 100.

Since the secondary battery 100 is surrounded by the first and second

insulating tapes

140 and 150 and no current leaks out, the surface current of the secondary battery 100 affects insulation characteristics. After module assembly, the insulation creepage distance between the outer metal frame 200 and the secondary battery 100 becomes a surface path from the outer metal frame 200 to the conductive member exposed to the outside of the secondary battery 100.

In the case of the secondary battery 100 of the first embodiment, the insulation safety distance (shown by the arrow path A) is approximately the width of the second portion 144 and the width of the first portion 143 and the first portion 143. It may be expressed as the sum of the distances between the first terminals 160.

Referring to FIG. 6, the first insulating tape 240 of the comparative example covers the outer surface of the cap plate 130. In this case, a part of the inner surface 121 of the case 120 is exposed at the opening side end of the case 120, and in the process of attaching the first insulating tape 240 over the cap plate 130, the cap plate ( A portion of the edge of 130 may be exposed to the outside.

In the case of the secondary battery of the comparative example, the insulation safety distance (shown by the arrow path B) may be expressed as the sum of the width of the cross section 122 and the width of a portion of the inner surface 121 of the case 120 exposed to the outside.

Referring to FIGS. 5 and 6, in the secondary battery 100 of the first embodiment, as the auxiliary insulation part 142 is formed on the first insulating tape 140, the external metal frame 200 and the secondary metal frame 200 are formed in the large capacity battery module. The insulation safety distance between the cells 100 can be effectively increased, and as a result, insulation properties can be improved as compared with the secondary battery of the comparative example.

7 is a partially enlarged cross-sectional view of a rechargeable battery according to a second exemplary embodiment of the present invention, and FIG. 8 is a perspective view of a first insulating tape of the rechargeable battery illustrated in FIG. 7.

7 and 8, in the rechargeable battery 100a of the second embodiment, the first insulating tape 340 includes a protrusion 146 formed on the cap insulating portion 141. The protruding portion 146 is a portion of the cap insulation portion 141 overlapping two layers and attached to each other, and protruding to the outside of the cap plate 130 without covering the outer surface of the cap plate 130.

The first terminal 160 and the second terminal 170 face each other along the first direction. The auxiliary insulator 142 may include the first and second

auxiliary insulators

142a and 142b facing each other along the first direction with the first and

second terminals

160 and 170 interposed therebetween, and the remaining third and the second and insulator portions 142a and 142b. 4 auxiliary insulating

parts

142c and 142d.

The two protrusions 146 are positioned between the first auxiliary insulation 142a and the first terminal 160 and between the second auxiliary insulation 142b and the second terminal 170 and intersect with the first direction. It is formed parallel to the second direction.

The protruding portion 146 is added to the cap insulation portion 141, and because the extra insulation is made by folding two layers, the auxiliary insulation is not connected to both sides of the protruding portion 146. That is, the third and fourth auxiliary insulating

parts

142c and 142d form cutouts 147 on both sides of the protrusion 146, and the third and fourth auxiliary insulating

parts

142c and 142c are formed by the cutouts 147. 142d) Each is divided into three parts.

Since the protrusion 146 is a portion in which a part of the cap insulation portion 141 is overlapped in two layers, an insulation safety distance (shown by a C arrow path) between the external metal frame 200 and the secondary battery 100a is determined as described above. The protrusion 146 is twice as wide as in the first embodiment. Accordingly, the secondary battery 100a of the second embodiment may further improve insulation characteristics by increasing the insulation safety distance due to the protrusion 146.

In the secondary battery 100a of the second embodiment, the rest of the configuration except for the protrusion 146 is the same as in the above-described first embodiment, and thus redundant description thereof will be omitted.

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 range of.

Description of the sign

100: secondary battery 110: electrode assembly

120: case 130: cap plate

140: first insulating tape 141: cap insulating portion

142: auxiliary insulating portion 150: second insulating tape

160: first terminal 170: second terminal

181: first lead tab 182: second lead tab

191: first insulating member 192: second insulating member

200: outer metal frame

Claims

An electrode assembly;

A case accommodating the electrode assembly and having an opening formed at one side thereof;

A cap plate exposing an opening end of the case and coupled to an inside of the case to seal the electrode assembly; And

A first insulating tape including a cap insulating portion covering an outer surface of the cap plate and an auxiliary insulating portion covering an opening end of the case;

Secondary battery comprising a.
The method of claim 1,

Further comprising a second insulating tape covering the outer surface of the case,

A part of the auxiliary insulating part on the outer surface of the case overlaps with the second insulating tape.
The method of claim 1,

The cap insulator comprises four sides,

The secondary battery is divided into four and the secondary battery is formed to be connected to one of the four sides of the cap insulation.
The method of claim 3,

Each of the four auxiliary insulating parts is folded in a depressed shape from the cap insulating part and attached to an opening end of the case.
The method of claim 4, wherein

Each of the four auxiliary insulations,

A first portion folded from the cap insulation and attached to an inner surface of the case;

A second portion folded from the first portion and attached to an end surface of the case; And

A third portion folded from the second portion and attached to an outer surface of the case

Secondary battery comprising a.
The method of claim 3,

The cap plate is provided with first and second terminals, sealing plugs, and vent plates,

The cap insulating part may include a plurality of openings that expose the first and second terminals, the sealing plug, and the vent plate.
The method of claim 6,

The first terminal and the second terminal face each other along a first direction,

The four auxiliary insulating parts include first and second auxiliary insulating parts facing each other along the first direction with the first and second terminals interposed therebetween, and the remaining third and fourth auxiliary insulating parts.
The method of claim 7, wherein

The cap insulation part further includes a protrusion part of which is overlapped with each other in two layers and protrudes outwardly of the cap plate.
The method of claim 8,

The protrusion is formed in parallel with a second direction crossing the first direction between the first auxiliary insulating part and the first terminal and between the second auxiliary insulating part and the second terminal.
The method of claim 9,

Each of the third and fourth auxiliary insulating parts forms cutouts on both sides of the protrusion.