KR100717754B1 - Secondary battery - Google Patents

Abstract

The secondary battery according to the present invention includes an electrode group including a positive electrode and a negative electrode, and a separator disposed between the positive electrode and the negative electrode so that the case can be stably insulated, the case in which the electrode group is built, and coupled to the case. A cap plate sealing the case, an electrode terminal having a lead portion protruding outward of the case and electrically connected to the electrode group, and installed between the electrode terminal and the cap plate, wherein the lead portion and the And a gasket provided with a blocking portion to insulate the case.

Secondary Battery, Gasket, Breaker, Lead

Description

Secondary Battery {SECONDARY BATTERY}

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

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

3 is a cutaway perspective view illustrating a gasket according to the first embodiment of the present invention.

4 is a perspective view showing a gasket according to the second embodiment of the present invention.

5 is a perspective view illustrating a gasket according to a third exemplary embodiment of the present invention.

The present invention relates to a secondary battery, and more particularly, to a secondary battery having an improved structure of a gasket installed in a terminal insertion hole.

A secondary battery is a battery that can be charged and discharged unlike a primary battery that is not rechargeable. Low-capacity secondary batteries are used in portable electronic devices such as mobile phones, notebook computers, and camcorders, and large-capacity batteries are widely used as power sources for driving motors in hybrid vehicles.

The secondary battery is manufactured in various shapes. Typical shapes include cylindrical and rectangular shapes.

Recently, the high-output secondary battery, which can be used for driving a motor requiring a large power, for example, an electric vehicle, connects a plurality of series in series to form a large capacity secondary battery.

As described above, one large capacity secondary battery (hereinafter, referred to as a battery module for convenience of description throughout) is made of a secondary battery (hereinafter, referred to as a unit cell for convenience of description throughout) of a plurality of connected in series or in parallel.

Each unit cell includes a case having an electrode group in which a cathode and a cathode are disposed with a separator interposed therebetween, and a space in which the electrode group is built, a cap plate coupled to the case and sealing the electrode group; The positive electrode terminal and the negative electrode terminal which are electrically connected and inserted into the terminal insertion hole formed in the cap plate and protrude outward, and a gasket inserted into the terminal insertion hole to ensure the tightness.

The electrode terminal including the positive terminal and the negative terminal includes an external terminal protruding to the outside and a lead portion formed under the external terminal and electrically connected to the electrode group.

The lead portion is joined to the uncoated portion formed at both ends of the electrode group by welding or the like. In this case, a part of the lead portion is fitted to the electrode group, but the rest has a structure protruding outside the electrode group.

At this time, the lead portion is located close to the case, but if the lead portion is in contact with the case, the lead portion and the case is in contact with the short circuit occurs.

In particular, when the unit cell is installed in an electric vehicle or the like and used for driving a motor, when vibration is transmitted inside the unit cell and the electrode terminal is shaken, the probability of contact between the electrode terminal and the case is further increased and a short circuit occurs accordingly. As a result, the unit cell may be overheated or severely exploded.

The present invention is to solve the above problems, an object of the present invention is to provide a secondary battery comprising a gasket for stably insulating the electrode terminal and the case.

In order to achieve the above object, a secondary battery according to the present invention includes an electrode group including a positive electrode and a negative electrode, and a separator disposed between the positive electrode and the negative electrode, a case in which the electrode group is built, and coupled to the case. An electrode terminal having a cap plate that seals the case and a lead portion protruding outward of the case and electrically connected to the electrode group, and installed between the electrode terminal and the cap plate, wherein the lead portion and the And a gasket provided with a blocking portion to insulate the case.

The electrode terminal may include an external terminal portion protruding to the outside of the case, a flange portion positioned below the external terminal portion, and a lead portion installed below the flange portion and attached to the electrode group.

The gasket may include a protrusion part into which the electrode terminal is inserted, a flange support part formed under the protrusion part to contact the flange part, and a blocking part formed under the flange support part.

The blocking part may be formed to have a structure surrounding the lead part.

The blocking portion may be formed of a plate member.

The blocking part may have a structure in which a cross section is bent in an arc shape.

The blocking portion may be made of a flat member.

The blocking portion may be formed bent portion bent at both ends.

The blocking part may have a length corresponding to the length of the lead part.

Here, the secondary battery (or battery module) is a device that operates by using a motor such as a HEV (hybrid car), an EV (electric vehicle), a wireless cleaner, an electric bicycle, an electric scooter, and the like to drive a motor of the device. It can be used as an energy source.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

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

Referring to the drawings described above, the secondary battery 10 according to the present embodiment includes an electrode group 15 in which the positive electrode 11 and the negative electrode 12 are positioned with the separator 13 interposed therebetween, and the electrode group. A case 14 having one end open to accommodate the 15, a cap plate 17 coupled to the case 14 to seal the case 14, and the electrode group 15 electrically. Electrode terminals 21 and 22 connected to and inserted into the cap plate 17.

Here, the electrode group 15 includes a separator 13 including a coating part coated with an active material on a current collector and an uncoated part 11a, 12a on which an active material is not applied to the current collector. ) May be formed in a stacked configuration, or in the state in which the anode 11, the separator 13, and the cathode 12 are stacked, they may have a jelly-roll type formed by winding them in a vortex.

An electrode terminal is electrically connected to the electrode group 15. The positive electrode terminal 21 is electrically connected to the positive electrode uncoated portion 11a, and the negative electrode terminal 22 is electrically connected to the negative electrode uncoated portion 12a.

As shown in FIG. 2, the electrode terminals 21 and 22 may have outer terminal portions 21a and 22a protruding out of the cap plate 17 and flange portions formed under the outer terminal portions 21a and 22a. (21b, 22b) and lead portions (21c, 22c) formed below the flange portions (21b, 22b) and attached to the uncoated portions (11a, 12a) of the electrode group (15).

The positive electrode lead portion 21c formed on the positive electrode terminal 21 is connected to the positive electrode uncoated portion 11a, and the negative electrode lead portion 22c formed on the negative electrode terminal 22 is connected to the negative electrode uncoated portion 12a. The lead portions 21c and 22c are fixed to the uncoated portions 11a and 12a of the electrode group 15 by ultrasonic welding or the like.

The case 14 is made of a conductive metal such as aluminum, an aluminum alloy, or nickel plated steel, and the shape of the case 14 has an inner space in which the electrode group 15 is located, and is formed in an open shape at one end. In the present embodiment, the rectangular secondary battery 10 is described as an example, but the present invention is not limited thereto and may be formed in a cylindrical or other shape in addition to the rectangular.

In addition, a cap plate 17 is coupled to the open end of the case 14 to seal the case 14, and electrode terminals 21 and 22 are inserted into the cap plate 17 to the outside of the case 14. An electrode terminal insertion hole 16 protruding from the electrode is formed.

The electrode terminal insertion hole 16 is provided with a gasket 25 that insulates the electrode terminals 21 and 22 and the cap plate 17 and seals the electrode terminal insertion hole 16.

The gasket 25 is made of an elastic insulator such as silicone and rubber. In addition, the gasket 25 is a protrusion 25a fitted to the electrode terminal insertion hole 16 and a flange support portion 25b formed below the protrusion 25a to be in contact with the bottom surface of the cap plate 17, and the It is provided below the flange support part 25b, and includes the interruption | block part 25c which insulates the lead part 21c, 22c of the electrode terminal 21, 22, and the case 14. As shown in FIG.

As shown in FIG. 3, the protrusion 25a is formed in a cylindrical tube shape so that the protrusion 25a can be inserted into the electrode terminal insertion hole 16 while the external terminal parts 21a and 22a are inserted.

The flange supporting portion 25b insulates the flange portions 21b and 22b of the electrode terminals 21 and 22 from the cap plate 17 and surrounds the upper and outer peripheral surfaces of the flange portions 21b and 22b. Made of structure.

In addition, the blocking portion 25c is formed of a curved plate member extending downward from the flange support portion 25b so as to surround the outside of the lead portions 21c and 22c protruding outward from the electrode group 15, Preferably it consists of a semicircular cross-sectional structure.

Therefore, the blocking part 25c is positioned between the lead parts 21c and 22c and the case 14 to insulate the lead parts 21c and 22c and the case 14. In particular, the blocking part 25c is formed in a curved shape in an arc shape and can be stably insulated while covering the lead parts 21c and 22c.

4 is a perspective view showing a gasket according to the second embodiment of the present invention.

Referring to the drawings described above, the gasket 30 according to the present embodiment is formed below the protrusion 31 and the protrusion 31 having a cylindrical tubular shape to insulate between the flange portion and the cap plate 17. It comprises a flange support portion 32, and the structure extending down from the flange support portion 32 comprises a blocking portion 33 to insulate the leads (21c, 22c) and the case (14).

The flange support part 32 according to the present exemplary embodiment has a rectangular plate structure, and has a central portion penetrated so that the positive terminal 21 or the negative terminal 22 can be inserted therein. And the blocking portion 33 is formed, the blocking portion 33 is made of a flat plate shape.

5 is a perspective view illustrating a gasket according to a third exemplary embodiment of the present invention. Referring to the drawings described above, the gasket 40 according to the present embodiment is formed under the protrusion 41 and the protrusion 41 to be inserted into the terminal insertion hole 16 of the electrode terminals 21 and 22. A flange support portion 42 is in contact with the flange portion, and a blocking portion 43 formed below the flange support portion 42 to insulate the lead portions 21a and 22a from the case 14.

The blocking portion 43 includes a plate portion 43a extending downward from the flange support portion 42 and a bent portion 43b formed at both ends of the plate portion 43a. The blocking portion 43 is made of a width corresponding to the inner surface of the case 14, the bent portion 43b is preferably formed to contact the inner edge of the case (14). Therefore, the blocking part 43 has a structure bent in a 'c' shape to insulate the lead parts (21c, 22c) from the outside and both side ends.

The secondary battery of the present invention is a device that operates by using a motor such as a hybrid electric vehicle (HEV), an electric vehicle (EV), a wireless cleaner, an electric bicycle, an electric scooter, and the like, and is used as an energy source for driving a motor of the device. Can be used.

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

As described above, according to an exemplary embodiment of the present invention, an avoidance part may be formed on the outer side of the gasket to maximize the size of the gasket. In the process of fixing the cap plate and the case by welding, the gasket and the laser interfere with the welding defect. It can be prevented from occurring to improve the structural stability and reliability of the secondary battery.

Claims (10)

An electrode group including an anode and a cathode, and a separator disposed between the anode and the cathode; A case in which the electrode group is built; A cap plate coupled to the case to seal the case; An electrode terminal protruding out of the case and having a lead part electrically connected to the electrode group; And A gasket that insulates the electrode terminal from the cap plate and the case by fitting the electrode terminal; Including; A secondary battery is formed in the lower portion of the gasket is provided between the lead portion and the case, the plate-shaped blocking portion to insulate the lead portion and the case. According to claim 1, The electrode terminal and the outer terminal portion protruding to the outside of the case A flange portion located below the outer terminal portion, and A secondary battery comprising a lead portion provided below the flange portion and attached to the electrode group. The method of claim 2, The gasket includes a protrusion into which the electrode terminal is inserted; A flange support part formed below the protrusion part and in contact with the flange part; Secondary battery comprising a blocking portion formed below the flange support. According to claim 1, The blocking part is formed of a structure surrounding the lead part. delete According to claim 1, The blocking part is a secondary battery having a cross-section curved in an arc shape. According to claim 1, The blocking unit is a secondary battery comprising a flat member. According to claim 1, The blocking part is a secondary battery having a bent portion formed at both ends. According to claim 1, The blocking unit is a secondary battery made of a length corresponding to the length of the lead portion. According to claim 1, The secondary battery is a secondary battery for driving a motor.

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