KR20060028187A - Li secondary battery - Google Patents

Abstract

The present invention relates to a lithium secondary battery having an insulating case which is more easily inserted into a case for a lithium secondary battery and can reduce manufacturing costs. The present invention relates to a lithium secondary battery including a first electrode plate, a second electrode plate, the first electrode plate, and a first electrode plate. An electrode assembly having a separator interposed between the two electrode plates; A case having a space for accommodating the electrode assembly; A cap assembly coupled to and sealing the case; Comprising a body portion and a side portion folded in close contact with the body side end surface, characterized in that to provide a lithium secondary battery comprising an insulating case for electrically insulating the electrode assembly and the cap assembly.

Lithium Secondary Battery, Insulation Case, Notch

Description

Lithium Secondary Battery

1 is a perspective view for explaining a conventional insulating case.

Figure 2 is an exploded perspective view for explaining a lithium secondary battery according to an embodiment of the present invention.

3A is an exploded view illustrating an insulating case of a lithium secondary battery according to an embodiment of the present invention.

Figure 3b is a perspective view for explaining an insulating case of a lithium secondary battery according to an embodiment of the present invention.

4 is an exploded view illustrating an insulating case of a lithium secondary battery according to another embodiment of the present invention.

(Explanation of symbols for main parts of drawing)

200; Lithium secondary battery 210; case

300; Electrode assembly 310; First electrode plate

315; First electrode tab 320; Second electrode plate

325; Second electrode tab 330; Separator

340; Insulating tape 400; Cap assembly

410; Cap plate 411; Terminal through hole

412; Electrolyte injection hole 420; Electrode terminals

430; Gasket 440; Insulation Plate

450; Terminal plate 460; Insulated case

462; Electrolyte injection aperture 465; Body

467; Side portion 468; Notch

The present invention relates to a lithium secondary battery, and more particularly, to a lithium secondary battery having an insulating case that can be more easily inserted into the case for a lithium secondary battery and the manufacturing cost can be reduced.

Recently, compact and lightweight electric / electronic devices such as cellular phones, notebook computers, camcorders, etc. have been actively developed and produced. These portable electric / electronic devices have a battery pack that can be operated in a place where no separate power source is provided. The built-in battery pack includes at least one battery therein for outputting a predetermined level of voltage for driving the portable electric / electronic device for a period of time.

In view of economical aspects, the battery pack employs a secondary battery capable of charging and discharging. Representative secondary batteries include lithium secondary batteries such as nickel-cadmium (Ni-Cd) batteries, nickel-hydrogen (Ni-MH) batteries, lithium (Li) batteries, and lithium ion (Li-ion) batteries.

In particular, the lithium secondary battery has an operating voltage of 3.6 V, which is three times higher than that of a nickel-cadmium battery or a nickel-hydrogen battery, which is widely used as a power source for portable electronic equipment, and is rapidly expanding in terms of high energy density per unit weight. It is a trend.

Such lithium secondary batteries mainly use lithium-based oxides as positive electrode active materials and carbon materials as negative electrode active materials. In general, a battery is classified into a liquid electrolyte battery and a polymer electrolyte battery according to the type of electrolyte, and a battery using a liquid electrolyte is called a lithium ion battery, and a battery using a polymer electrolyte is called a lithium polymer battery. Moreover, although a lithium secondary battery is manufactured in various shapes, typical shapes include cylindrical shape, square shape, and pouch type.

Typically, the lithium secondary battery is positioned between the positive electrode plate coated with a positive electrode active material, the negative electrode plate coated with a negative electrode active material, and between the positive electrode plate and the negative electrode plate to prevent a short and prevent lithium ion (Li-ion). And an electrode assembly in which a separator capable of moving only is wound, a lithium secondary battery case accommodating the electrode assembly, and an electrolyte solution injected into the lithium secondary battery case to enable movement of lithium ions.

The lithium secondary battery is coated with the positive electrode active material, the positive electrode electrode plate is connected to the positive electrode tab, the negative electrode active material is coated, the negative electrode plate is connected to the negative electrode tab and the separator is laminated, and then wound to prepare an electrode assembly.

Then, the electrode assembly is accommodated in the lithium secondary battery case, the insulating case is seated, and then the cap assembly is combined with the lithium secondary battery case to prevent the electrode assembly from detaching, and then the electrolyte solution in the lithium secondary battery case. After the injection, sealing is completed to complete the lithium secondary battery.

However, the lithium secondary battery as described above has a problem in that the insulating case flows due to an external impact or the like, causing a short between the positive electrode plate and the negative electrode plate of the electrode assembly.

In order to solve this problem, as shown in Figure 1, by forming a protrusion 110 protruding a predetermined length in the lower side of the insulating case 100, the insulating case 100 is in close contact with the case for the lithium secondary battery flows The structure which prevents it is adopted. However, when the insulating case 100 having the protrusion 110 is inserted into the lithium secondary battery case, it is difficult to insert it due to the protrusion. In addition, the insulating case 100 has a complicated structure, the mold for forming the insulating case 100 is complicated, there is a difficulty in manufacturing, there is a problem that the manufacturing cost increases.

An object of the present invention is to solve the above problems of the prior art, the present invention is more easily inserted into a case for a lithium secondary battery, and to provide a lithium secondary battery having an insulating case that can reduce the manufacturing cost Has its purpose.

The present invention for achieving the above object is an electrode assembly having a separator interposed between the first electrode plate, the second electrode plate, the first electrode plate and the second electrode plate; A case having a space for accommodating the electrode assembly; A cap assembly coupled to and sealing the case; Comprising a body portion and a side portion folded in close contact with the body side end surface, characterized in that to provide a lithium secondary battery comprising an insulating case for electrically insulating the electrode assembly and the cap assembly.

The insulating case further includes a notch portion formed between the body portion and the side portion, wherein the side portion is folded and adhered to the short side surface of the body portion through the notch portion.

In this case, the notch may be formed on an upper surface of the insulating case, or the notch may be formed on a lower surface of the insulating case.

In addition, the width of the side portion is greater than the width of the body portion, it is preferable that the side portion protrudes in the minor axis direction of the body portion in close contact with the body portion.

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

2 is an exploded perspective view for describing a lithium secondary battery according to an embodiment of the present invention.

Referring to FIG. 2, the lithium secondary battery 200 according to the exemplary embodiment of the present invention includes a lithium secondary battery case 210 and a jelly-roll electrode assembly 300 accommodated in the lithium secondary battery case 210. ) And a cap assembly 400 coupled to an upper portion of the lithium secondary battery case 210.

The lithium secondary battery case 210 is formed of a metal can having a shape of a substantially box (box) having an upper opening, and may itself serve as a terminal.

The electrode assembly 300 is attached to any one of the first electrode tab 315 used as the positive electrode tab and the second electrode tab 325 used as the negative electrode tab, for example, the first electrode tab 315. The second electrode plate 320 to which the first electrode plate 310 and the other one of the first electrode tab 315 and the second electrode tab 325 are attached, for example, the second electrode tab 325. The separator 330 interposed between the first electrode plate 310 and the second electrode plate 320 is wound to be accommodated in the lithium secondary battery case 310. In order to prevent a short circuit between the first electrode plate 310 and the second electrode plate 320 at the boundary where the first electrode tab 315 and the second electrode tab 325 are drawn out from the electrode assembly 300. Each is insulated by an insulating tape 340.

In addition, the first electrode plate 310 and the second electrode plate 320 have different polarities from each other, and at least one surface of each of the first electrode plate 310 and the second electrode plate 320 may be a positive electrode active material or a negative electrode. The active material is applied. In this case, a chalcogenide compound is used as the cathode active material, and complex metal oxides such as LiCoO 2, LiMn 2 O 4, LiNiO 2, LiNi 1-x Cox O 2 (0 <x <1), and LiMnO 2 are used. As the negative electrode active material, carbon (C) -based materials, Si, Sn, tin oxides, composite tin alloys, transition metal oxides, lithium metal nitrides, or lithium metal oxides are used. In addition, an electrode plate used as a positive electrode plate among the first electrode plate 310 and the second electrode plate 320, for example, the first electrode plate 310 is made of aluminum (Al) and a cathode electrode plate. The electrode plate used as, for example, the second electrode plate 320 is made of a copper (Cu) material, the separator 330 generally uses polyethylene (PE) or polypropylene (PP), but The invention is not limited to the above materials.

The cap assembly 400 is provided with a flat cap plate 410 having a size and shape corresponding to the opening of the secondary battery case 210. A terminal through hole 411 is formed at the center of the cap plate 410, and an electrolyte injection hole 412 for injecting an electrolyte is formed at one side of the cap plate 410, and the electrolyte injection hole 412. ) Is combined with the bowl 415 and sealed.

An electrode terminal 420, for example, a negative electrode terminal, may be inserted into the terminal throughhole 411. The outer surface of the electrode terminal 420 is provided with a tube-shaped gasket 430 for electrical insulation with the cap plate 410. An insulating plate 440 is disposed on the bottom surface of the cap plate 410. The terminal plate 450 is installed on the lower surface of the insulating plate 440.

The electrode terminal 420 is inserted through the terminal through hole 411 while the gasket 430 surrounds the outer circumferential surface. The bottom portion of the electrode terminal 420 is electrically connected to the terminal plate 450 with the insulating plate 440 interposed therebetween.

On the bottom surface of the cap plate 410, one of the first electrode plate 310 and the second electrode plate 320, for example, the first electrode tab 315 drawn from the first electrode plate 310 Is welded to the lower end of the electrode terminal 320, the second one drawn from another one of the first electrode plate 310 and the second electrode plate 320, for example, the second electrode plate 320. Electrode tab 325 is welded.

On the other hand, the upper surface of the electrode assembly 300 electrically insulates the electrode assembly 300 and the cap assembly 400, and at the same time an insulating case 460 that can cover the upper end of the electrode assembly 300 Is installed. The insulating case 460 is provided with an electrolyte injection hole 462 at a position corresponding to the electrolyte injection hole 412 of the cap plate 410, to inject the electrolyte solution. The insulating case 460 is an insulating polymer resin, preferably made of polypropylene, but the material is not limited in the embodiment of the present invention. In addition, the insulating case 460 includes a body portion 465 and a side portion 467, and the side portion 467 protrudes a predetermined length in a short direction of the body portion 465.

3A is an exploded view illustrating an insulation case of a lithium secondary battery according to an embodiment of the present invention, and FIG. 3B is a perspective view illustrating an insulation case of a lithium secondary battery according to an embodiment of the present invention.

3A and 3B, an insulating case 460 of a lithium secondary battery according to an exemplary embodiment of the present invention has a structure including a body portion 465 and a side portion 467.

The body part 465 covers an upper end of the electrode assembly 300 to electrically insulate the electrode assembly 300 from the cap assembly 400.

The side portion 467 is positioned in a short side direction of the body portion 465, and is folded when the insulating case is inserted into the lithium secondary battery case 210 so as to be folded to a short side of the body portion to closely contact the body portion. do. At this time, the width W1 of the side portion 467 is preferably larger than the width W2 of the body portion 465. When the insulating case 460 is accommodated in the lithium secondary battery case 210, the side part 467 of the insulating case 460 protrudes a predetermined length so that the insulating case 460 and the lithium secondary battery have a predetermined length. This is to prevent the flow of the insulating case 460 by strengthening the adhesion between the cases 210.

In addition, a notch portion 468 is formed between the body portion 465 and the side portion 467. The notch 468 is formed on an upper surface of the insulating case 460. This is to allow the side part 467 to be folded by itself when the insulating case 460 is accommodated in the lithium secondary battery case 210.

4 is an exploded view illustrating an insulating case of a lithium secondary battery according to another exemplary embodiment of the present invention.

Referring to FIG. 4, the insulating case 460 of the lithium secondary battery 200 according to another exemplary embodiment of the present invention is structurally similar to the insulating case 460 illustrated in FIGS. 2, 3A, and 3B.

However, only the structure in which the side portion 467 is formed on the lower surface of the insulating case 460 is different. That is, the side portion 467 is folded through the notch portion 468 formed on the lower surface of the insulating case 460 to be in close contact with the short side surface of the body portion 465.

In the lithium secondary battery 200 as described above, the insulating case 460 may be more easily accommodated in the lithium secondary battery case 210.

In addition, the body portion 465 and the side portion 467 as described above, the side portion 467 is folded by itself in the process of being inserted into the insulating case 460 in the lithium secondary battery case 210, the side portion 467 ), The structure of the mold for forming the insulating case 460 made of a structure such that the predetermined length protrudes in the short axis direction of the body portion 465 is more structure than the mold for forming the insulating case having a conventional projection. Simple. Therefore, the manufacturing cost for forming the insulating case 460 can be reduced.

In addition, by allowing the side portion 467 to protrude a predetermined length in the short axis direction of the body portion 465, the adhesion between the insulating case 460 and the lithium secondary battery case 210 may also be maintained.

As described above, according to the present invention, the present invention may provide a lithium secondary battery having an insulation case which is more easily inserted into a case for a lithium secondary battery and can reduce manufacturing costs.

While the foregoing has been described with reference to preferred embodiments of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

Claims (5)

An electrode assembly having a first electrode plate, a second electrode plate, a separator interposed between the first electrode plate and the second electrode plate; A case having a space for accommodating the electrode assembly; A cap assembly coupled to and sealing the case; Lithium secondary battery comprising a body portion and a side portion folded in close contact with the short side of the body portion, the insulating case for electrically insulating the electrode assembly and the cap assembly. The method of claim 1, The insulating case further includes a notch portion formed between the body portion and the side portion, wherein the side portion is a lithium secondary battery, characterized in that the folded in close contact with the short side of the body portion through the notch portion. The method of claim 2, And the notch portion is formed on an upper surface of the insulating case. The method of claim 2, And the notch portion is formed on a lower surface of the insulation case. The method of claim 1, The width of the side portion is greater than the width of the body portion, The side surface portion is a lithium secondary battery, characterized in that protruding in the minor axis direction of the body portion in a state in close contact with the body portion.

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