KR100646505B1 - Battery case using nonferrous metal and secondary battery using the same - Google Patents

Abstract

The technical field to which the present invention pertains relates to a battery exterior material using a nonferrous metal and a secondary battery using the same. The technical problem to be solved is high mechanical strength to stably protect the battery from external impact, and to reduce the thickness of the battery. It is possible to increase, and also to suppress the swelling phenomenon to prevent the appearance deformation of the battery.

SUMMARY OF THE INVENTION In order to solve the above technical problem, a gist of the present invention includes a nonferrous metal having an approximately flat first surface and an approximately flat second surface opposite thereto, and a first material such as modified polypropylene (CPP) formed on the first surface of the nonferrous metal. Disclosed are a battery packaging material including an insulating layer, a second insulating layer such as nylon or polyethylene terephthalate (PET) formed on a second surface of a nonferrous metal, and a secondary battery using the same.

Secondary battery, exterior material, nonferrous metal, insulation layer, modified polypropylene

Description

Battery case using nonferrous metal and secondary battery using same {Battery case using nonferrous metal and secondary battery using the same}

1 is a perspective view showing a state before a drawing portion is formed as a battery exterior material according to the present invention.

FIG. 2 is an enlarged cross-sectional view taken along line 1-1 of FIG. 1.

3A is a perspective view illustrating a state in which a drawing unit is formed to accommodate an electrode assembly and the like in a battery exterior material according to the present invention, and FIG. 3B is an enlarged cross-sectional view illustrating a region 3a of FIG. 3A.

4 is a perspective view illustrating a secondary battery according to the present invention.

5 is a cross-sectional view taken along the line 4-4 of FIG.

<Description of Symbols for Main Parts of Drawings>

10; Battery exterior material according to the present invention

11; Nonferrous metal 11a; Front page

11b; Second page 12; First insulation layer

13; Second insulating layer 16; Drawing

17a; First region 17b; Second area

20; Secondary battery according to the present invention

21; Electrode assembly 21a; Positive plate

21b; Negative plate 21c; Separator

22a; Positive electrode tab 22b; Negative electrode tab

23; Protective circuit board

The present invention relates to a battery exterior material using a non-ferrous metal and a secondary battery using the same. More specifically, the mechanical strength is high, so that the battery can be stably protected from external impact, and the thickness thereof can be reduced, thereby increasing battery capacity and swelling. The present invention relates to a battery exterior material using a non-ferrous metal and a secondary battery using the same, which can prevent ring deformation by preventing ring appearance.

In general, a secondary battery such as a lithium polymer battery has a separator between a positive electrode plate and a negative electrode plate (hereinafter, referred to as an electrode plate, a negative electrode plate, and a separator) as an electrode assembly. Says battery. The separator is formed of a gel polymer electrolyte, and is prepared in a state in which an electrolyte solution is impregnated into the polymer to improve ionic conductivity.

On the other hand, the characteristics of a lithium polymer battery and a lithium ion battery are briefly compared as follows.

First, since the lithium polymer battery can have a plate-like structure in structure, it is not necessary to adopt the winding process required in the process of the lithium ion battery. Therefore, the electrode assembly can be laminated in the form of a plurality of plates, and the electrode assembly can be manufactured in a shape that is very suitable for the square structure.

Second, since all of the electrolyte is injected into the integrated cell, there is almost no electrolyte exposed to the outside.

Third, because it can be a plate-like structure, there is no need to apply pressure when making a square. Thus, it is crucially possible to manufacture the battery packaging material in a thin, flexible pouch instead of a thick, rigid square or cylindrical can. Such pouches usually have an aluminum foil or stainless steel foil as a center layer, and have a structure in which a thin insulating layer is adhered or laminated on both surfaces thereof.

When the flexible pouch is used as a battery packaging material, the thickness of the flexible pouch can be significantly reduced compared to the can, and more electrode assemblies can be accommodated in the same volume. That is, the capacity of the battery can be significantly increased. In addition, since the battery packaging material is soft, the battery can be easily manufactured in a desired shape, and therefore, there is an advantage that it is easy to attach to various electronic devices.

However, such a pouch-type battery packaging material has a problem that, despite increasing battery capacity and workability in various forms, the mechanical strength is weak and very vulnerable to external shock. For example, when the battery case is stuck to a sharp object (for example, a needle or a nail), a hole is easily formed, and when a battery bite is bitten, it is easily torn. Furthermore, when such a sharp object penetrates through the exterior material and contacts the internal electrode assembly, the positive electrode plate and the negative electrode plate are shorted with each other, and the battery may ignite or explode.

Moreover, the secondary battery using such an exterior material has a disadvantage in that a swelling phenomenon in which the battery swells to the outside when it is left at high temperature occurs severely. That is, since the packaging material surrounding the electrode assembly is soft and the mechanical strength is weak, the thickness and the appearance of the battery are easily deformed by the gas generated in the polymer electrolyte therein.

The present invention is to overcome the above-mentioned conventional problems, an object of the present invention to provide a battery exterior material using a non-ferrous metal and a secondary battery using the same that can stably protect the battery from external shock by increasing the mechanical strength.

Another object of the present invention is to provide a battery exterior material using a non-ferrous metal and a secondary battery using the same, despite the increase in mechanical strength, the thickness can be made relatively thinner to increase the battery capacity.

Still another object of the present invention is to provide a battery exterior material using a non-ferrous metal and a secondary battery using the same, which can prevent the swelling phenomenon and prevent deformation and thickness of the battery.

In order to achieve the above object, the battery packaging material according to the present invention includes a nonferrous metal having a flat first surface and a flat second surface opposite thereto, a first insulating layer formed on the first surface of the nonferrous metal, and a second nonferrous metal. A second insulating layer formed on the surface.

Here, the nonferrous metal is copper, lead, tin, zinc, gold, platinum, nickel, magnesium, cadmium, uranium, thorium, plutonium, beryllium, titanium, zirconium, niobium, vanadium, hafnium, indium, tantalum, molybdenum, tungsten, silicon , Germanium, potassium, gallium may be formed of any one or an alloy thereof.

In addition, the thickness between the first surface and the second surface of the nonferrous metal may be 20 ~ 100um.

In addition, the nonferrous metal may have an elongation of 20 to 60%.

In addition, the first insulating layer may be modified polypropylene (CPP).

In addition, the second insulating layer may be any one selected from nylon and polyethylene terephthalate (PET).

In addition, the battery packaging material may include a first region having a drawing portion having a predetermined depth so as to accommodate an electrode assembly having a separator interposed between a plurality of positive electrode plates and a negative electrode plate, and beginning to be folded at one end of the first region to cover the drawing portion. It may include a second area.

In addition, the battery packaging material may be one in which the first insulating layer corresponding to the outer circumference of the drawing part of the first region and the second region is bonded to each other by thermal welding.

In addition, in order to achieve the above object, the secondary battery according to the present invention includes a plurality of positive electrode plates and a negative electrode plate provided with a separator, and has a positive electrode tab and a negative electrode tab connected to the outside by extending a predetermined length from the positive electrode plate and the negative electrode plate. The electrode assembly includes a first region having a drawing portion of a predetermined depth to accommodate the electrode assembly, and a non-ferrous metal exterior material having a second region to cover the drawing portion of the first region.

Here, the packaging material includes a non-ferrous metal having a first flat surface and a flat second surface opposite thereto, a first insulating layer formed on the first surface of the nonferrous metal, and a second insulating layer formed on the second surface of the nonferrous metal. Can be made.

In addition, the non-ferrous metal is copper, lead, tin, zinc, gold, platinum, nickel, magnesium, cadmium, uranium, thorium, plutonium, beryllium, titanium, zirconium, niobium, vanadium, hafnium, indium, tantalum, molybdenum, tungsten, silicon , Germanium, potassium, gallium may be formed of any one or an alloy thereof.

In addition, the thickness between the first surface and the second surface of the nonferrous metal may be 20 ~ 100um.

In addition, the nonferrous metal may have an elongation of 20 to 60%.

In addition, the first insulating layer may be modified polypropylene (CPP).

In addition, the second insulating layer may be any one selected from nylon and polyethylene terephthalate (PET).

The first insulating layer corresponding to the outer circumference of the drawing part of the first region and the second region may be bonded to each other by thermal welding.

In addition, the positive electrode tab and the negative electrode tab may be extended to a certain length outside the exterior member, the protective circuit board is located on the exterior member, the positive electrode tab and the negative electrode tab may be connected to the protective circuit board.

As described above, the present invention can stably protect the battery from external impact by using a non-ferrous metal having a high mechanical strength as an exterior material.

In addition, the present invention enables the thickness of the exterior material to be relatively thin due to the high mechanical strength of the packaging material, and thus the volume of the electrode assembly can be made larger by the thinner thickness, thereby further increasing the battery capacity. .

In addition, the present invention, by high mechanical strength of the packaging material, it is possible to fundamentally suppress the swelling phenomenon, to prevent the thickness and appearance deformation of the battery.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings such that those skilled in the art may easily implement the present invention.

Referring to FIG. 1, a state before a drawing portion is formed as a battery exterior material according to the present invention is illustrated, and referring to FIG. 2, an enlarged cross-sectional view taken along line 1-1 of FIG. 1 is illustrated.

As shown in the drawing, the battery packaging material 10 according to the present invention includes a non-ferrous metal 11, a first insulating layer 12 formed on one surface of the non-ferrous metal 11, and a second insulating layer formed on the other surface of the non-ferrous metal 11. It consists of (13).

First, the nonferrous metal 11 is composed of a first surface 11a that is approximately flat or completely flat, and a second surface 11b that is approximately flat or completely flat as an opposite surface thereof. In addition, the non-ferrous metal 11 has a thickness between about 20 μm and about 100 μm between the first surface 11 a and the second surface 11 b, and is formed to be thinner by several or tens of um. That is, since the non-ferrous metal 11 can increase the mechanical strength compared to the conventional, the thickness can be lower than the conventional. Moreover, the thickness can be made higher while the thickness is lowered. Thus, more volumes of electrode assemblies (not shown) can be accommodated in the volume as in the prior art. In addition, the nonferrous metal 11 is copper, lead, tin, zinc, gold, platinum, nickel, magnesium, cadmium, uranium, thorium, plutonium, beryllium, titanium, zirconium, niobium, vanadium, hafnium, indium, tantalum, molybdenum, Tungsten, silicon, germanium, potassium, gallium, or any one thereof, or an alloy thereof, or each alloy. The non-ferrous metal 11 has a high mechanical strength and corrosion resistance, thereby increasing the mechanical strength of the battery packaging material and improving the corrosion resistance of the electrolyte. Of course, the non-ferrous metal 11 is also excellent in efficiency to completely inhibit the penetration of moisture from the outside of the battery to the inside. On the other hand, the non-ferrous metal 11 is preferably used that the elongation is about 20 ~ 60% so that the drawing portion (not shown) and the like can be easily formed. That is, the non-ferrous metal 11 is a drawing portion of a predetermined depth is formed by a mold or the like so that the electrode assembly, etc. can be stored later, to adjust the elongation to the above value so that the non-ferrous metal 11 is not broken when forming the drawing portion. good. For example, the non-ferrous metal 11 can be adjusted to 20 to 60% by appropriately adjusting the alloy ratio or by heat treatment in a temperature of several hundred degrees and an inert gas atmosphere (or air atmosphere).

On the other hand, due to the characteristics of the non-ferrous metal 11 described above, the present invention can also appropriately suppress the swelling phenomenon that may occur in a high temperature situation after battery assembly. Therefore, the thickness and appearance deformation of the battery can also be sufficiently prevented.

Subsequently, the first insulating layer 12 formed on the first surface 11a of the nonferrous metal 11 may be modified polypropylene (CPP). The modified polypropylene (CPP) may be coated with a thickness of approximately 30 to 40 μm on the first surface 11 a of the nonferrous metal 11 through an adhesive (not shown). In addition, the modified polypropylene may be formed to be slightly thicker than the thickness of the nonferrous metal 11 since the electrode assembly and the like are in direct contact with each other and are thermally fused together.

Subsequently, the second insulating layer 13 formed on the second surface 11b of the nonferrous metal 11 may be any one selected from nylon or polyethylene terephthalate (PET). For example, the nylon or polyethylene terephthalate (PET) may be formed on the second surface 11b of the nonferrous metal 11 by a high temperature lamination method. In addition, the thickness may be approximately 5 ~ 10um. In addition, polyethylene terephthalate (PET) as the second insulating layer 13 may be an alloy film. More specifically, the polyethylene terephthalate (PET) may further include a powdery impact reinforcing rubber, an adhesion enhancing solubilizer and an adhesive surrounding the rubber. In this way, the present invention has better elongation and better impact resistance of the battery packaging material due to the powder-impact strengthening rubber contained in polyethylene terephthalate (PET). Furthermore, the present invention also has excellent adhesion to the nonferrous metal 11 due to the adhesion enhancing solubilizer surrounding the impact reinforcing rubber. That is, the adhesiveness with respect to the 2nd surface 11b of the nonferrous metal 11 improves. Furthermore, in the present invention, since the adhesive is pre-dispersed in polyethylene terephthalate (PET), it is possible to laminate polyethylene terephthalate (PET) at high temperature without the need to apply a special adhesive to the non-ferrous metal (11). That is, the manufacturing process of the battery packaging material 10 can be further simplified. Of course, there may be no adhesive among the components of the polyethylene terephthalate (PET). In this case, after applying the adhesive to the second surface 11b of the nonferrous metal 11 in advance, the polyethylene terephthalate (PET) is adhered to It may be formed.

Referring to FIG. 3A, a state in which the drawing unit 16 is formed to accommodate the electrode assembly and the like in the battery packaging 10 according to the present invention is illustrated as a perspective view. Referring to FIG. 3B, region 3a of FIG. 3A is illustrated. This is shown enlarged.

As shown in the drawing, the above-described battery exterior member 10 may be divided into a first region 17a and a second region 17b, each of which is folded and heat-sealed. A drawing portion 16 having a predetermined width and depth may be further formed in the first region 17a to accommodate an electrode assembly (not shown) having a separator interposed between the plurality of positive and negative plates. Of course, the drawing portion 16 may also be formed in the second region 17b. As described above, the elongation of the exterior material 10, that is, the nonferrous metal 11, which is a main material, should be about 20 to 60% so that the exterior material 10 is not damaged during the formation of the drawing part 16.

In addition, the drawing part 16 is formed while the first insulating layer 12 such as the modified polypropylene (CPP) is in direct contact with the mold. Therefore, as described above, the packaging material 10 has a thickness in the order of the first insulating layer 12> nonferrous metal 11> second insulating layer 13. Furthermore, since the first insulating layer 12 corresponding to the outer periphery of the drawing portion 16 of the first region 17a and the second region 17b is thermally fused to each other, the first insulating layer 12 ) Is the thickest.

Referring to FIG. 4, a perspective view of a rechargeable battery 20 according to the present invention is illustrated, and referring to FIG. 5, a cross-sectional view taken along line 4-4 of FIG. 4 is illustrated.

As shown, the secondary battery 20 according to the present invention includes an electrode assembly 21, an exterior member 10 surrounding the electrode assembly, and a protective circuit board 23 mounted on the surface of the exterior member.

The electrode assembly 21 is, for example, a positive electrode plate 21a in which a lithium-based oxide is bound to an aluminum (Al) foil, a negative electrode plate 21b in which a carbon-based component is bound to a copper (Cu) foil, and a separator that is a gel polymer electrolyte. A plurality of 21c layers are laminated. On the other hand, an anode tab 22a made of aluminum is connected to the aluminum foil of the cathode plate 21a, and a cathode tab 22b made of nickel is connected to the copper foil of the anode plate 21b. 22a) and the negative electrode tab 22b may be formed to extend a predetermined length to the outside of the packaging material 10.

As described above, the exterior member 10 includes a first region 17a having a drawing portion 16 having a predetermined depth so that the electrode assembly 21 can be accommodated, and a drawing portion of the first region 17a. It consists of the 2nd area | region 17b which covers 16).

Of course, the exterior member 10 may be formed of the non-ferrous metal 11, the first insulating layer 12 such as modified polypropylene (CPP) formed on one surface of the non-ferrous metal 11, and the non-ferrous metal 11. It may be made of a second insulating layer 13, such as nylon or polyethylene terephthalate (PET) formed on the other surface. Of course, an adhesive may be further interposed between the nonferrous metal 11 and the first insulating layer 12, or between the nonferrous metal 11 and the second insulating layer 13. The electrode assembly 21 of the packaging material 10 having such a configuration is surrounded by the first insulating layer 12 such as the modified polypropylene (CPP), the outermost surface is nylon or polyethylene terephthalate ( A second insulating layer 13 such as PET) is formed. In addition, the battery packaging material 10 includes a first insulating layer 12 which is a portion 17c of the first region 17a and the second region 17b corresponding to the outer circumference of the drawing portion 16. At the same time as heat-sealed and bonded, it can be folded in a predetermined direction so that the volume of the exterior material 10 is minimized. Finally, all the remaining features of the exterior member 10 are the same as those of Figs. 1 to 3b, and further description thereof will be omitted.

The protective circuit board 23 is attached to one side of the exterior member 10 to protect the battery 20 from an overcharge voltage (current) or an overdischarge voltage (current). Of course, the protective circuit board 23 is electrically connected to the positive electrode tab 22a and the negative electrode tab 22b.

As described above, the battery exterior material and the secondary battery using the non-ferrous metal according to the present invention by using the non-ferrous metal having a large mechanical strength as an exterior material, there is an effect capable of stably protecting the battery from external impact.

In addition, the present invention is capable of making the thickness relatively thin due to the high mechanical strength of the packaging material, and thus, the volume of the electrode assembly can be made larger by the thinner thickness, so that the capacity of the battery can be further increased. There is.                     

In addition, the present invention has a high mechanical strength of the packaging material, thereby essentially suppressing the swelling phenomenon, it is possible to prevent the thickness and appearance deformation of the battery.

What has been described above is just one embodiment for carrying out the battery packaging material and the secondary battery using the non-ferrous metal according to the present invention, the present invention is not limited to the above-described embodiment, which is claimed in the claims As will be apparent to those skilled in the art to which the present invention pertains without departing from the gist of the present invention, the technical spirit of the present invention may be changed to the extent that various modifications can be made.

Claims (18)

A non-ferrous metal having a flat first side and a flat second side opposite thereto; A first insulating layer formed on the first surface of the nonferrous metal, A second insulating layer formed on the second surface of the nonferrous metal, The non-ferrous metal battery packaging material, characterized in that the elongation is 20 ~ 60%. The method of claim 1, wherein the nonferrous metal is copper, lead, tin, zinc, gold, platinum, nickel, magnesium, cadmium, uranium, thorium, plutonium, beryllium, titanium, zirconium, niobium, vanadium, hafnium, indium, tantalum, molybdenum And tungsten, silicon, germanium, potassium, gallium, or any one selected from these alloys. The battery packaging material according to claim 1, wherein a thickness between the first and second surfaces of the nonferrous metal is 20 to 100um. delete The battery packaging material according to claim 1, wherein the first insulating layer is modified polypropylene (CPP). The method of claim 1, wherein the second insulating layer is a battery packaging material, characterized in that any one selected from nylon or polyethylene terephthalate (PET). The method of claim 1, wherein the battery packaging material has a first region having a drawing portion of a predetermined depth so that an electrode assembly with a separator interposed between the plurality of positive electrode plates and the negative electrode plate, and start folding at one end of the first region And a second area covering the drawing part. 8. The battery packaging material according to claim 7, wherein the battery packaging material is formed by bonding a first insulating layer corresponding to the outer circumference of the drawing part among the first region and the second region by thermal welding. delete An electrode assembly having a plurality of positive electrode plates and a negative electrode plate provided through a separator, and having a positive electrode tab and a negative electrode tab connected to the outside by a predetermined length from the positive electrode plate and the negative electrode plate; And, And a first region having a drawing portion having a predetermined depth to accommodate the electrode assembly, and a non-ferrous metal exterior material having a second region to cover the drawing portion of the first region. battery. The method of claim 10, wherein the packaging material A non-ferrous metal having a first flat surface and a flat second surface opposite thereto; A first insulating layer formed on the first surface of the nonferrous metal; And, And a second insulating layer formed on the second surface of the nonferrous metal. The method of claim 10, wherein the non-ferrous metal is copper, lead, tin, zinc, gold, platinum, nickel, magnesium, cadmium, uranium, thorium, plutonium, beryllium, titanium, zirconium, niobium, vanadium, hafnium, indium, tantalum, molybdenum And tungsten, silicon, germanium, potassium, gallium, or any one selected from the alloys thereof. The secondary battery of claim 10, wherein a thickness between the first surface and the second surface of the nonferrous metal is 20 μm to 100 μm. The secondary battery of claim 10, wherein the nonferrous metal has an elongation of 20 to 60%. The secondary battery of claim 10, wherein the first insulating layer is modified polypropylene (CPP). The secondary battery of claim 10, wherein the second insulating layer is any one selected from nylon and polyethylene terephthalate (PET). The secondary battery of claim 10, wherein a first insulating layer corresponding to an outer circumference of the drawing part of the first region and the second region is bonded to each other by thermal welding. The method of claim 10, wherein the positive electrode tab and the negative electrode tab is a predetermined length extending to the outside of the packaging material, a protective circuit board is located on the packaging material, the protective circuit board is characterized in that the positive electrode tab and the negative electrode tab is connected. Secondary battery.

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