KR20230127445A - A Battery Cell Having a Venting Gas Inducing Part On a Lead Film And a Battery Module Including It - Google Patents

Abstract

The present invention relates to a battery cell having a venting gas guide in a lead film and a battery module including the same, and more specifically, to a case made of a laminated sheet including an inner resin layer, a metal layer, and an outer resin layer, and an electrode accommodated in the case. An assembly, an electrode tab positioned on a side of the electrode assembly, an electrode lead having one side connected to the electrode tab and the other side protruding out of the case, and a lead film provided on upper and lower surfaces of the electrode lead, the lead film relates to a battery cell having a venting gas induction part in a lead film, characterized in that one or more molten parts having a pattern shape are formed, and a battery module including the same.

Description

A battery cell having a venting gas inducing part on a lead film and a battery module including the same

The present invention relates to a battery cell having a venting gas induction unit in a lead film and a battery module including the same, and specifically, a molten unit that melts at a relatively lower temperature than the lead film is provided in the lead film, so that gas is generated in the case. It relates to a battery cell having a venting gas guiding unit on a lead film capable of guiding a venting gas discharge direction, and a battery module including the same.

Demand for secondary batteries capable of storing electrical energy produced due to the development of alternative energy due to air pollution and energy depletion due to the use of fossil fuels has recently increased. Secondary batteries capable of charging and discharging are closely used in daily life, such as being used in mobile devices, electric vehicles, hybrid electric vehicles, and the like.

Secondary batteries, which are used as an energy source for various electronic devices indispensably used in modern society, are increasing in capacity due to the increase in usage and complexity of mobile devices and the development of electric vehicles. A plurality of battery cells are disposed in small devices to meet user demand, but a battery module electrically connecting a plurality of battery cells or a battery pack having a plurality of such battery modules is used in automobiles and the like.

On the other hand, battery cells generate high-temperature heat or venting gas due to various causes such as overcharge, overcurrent, or external shock. Car damage may occur.

1 is a perspective view showing a battery cell according to the prior art. Referring to FIG. 1, a battery cell according to the prior art includes a pouch case 10, an electrode assembly 20 accommodated in the pouch case 10, one side of the electrode assembly 20 is connected to the electrode assembly 20, and the other side is a pouch. An electrode lead 30 protruding outward from the case 10 and a sealant 40 surrounding the electrode lead 30 are included, and a notch 41 is formed in the sealant 40 .

In the battery cell according to the prior art, the notch 41 of the sealant 40 is broken when high-temperature heat and venting gas are generated from the electrode assembly 20 stored inside the battery cell due to overcharging, overcurrent, and external impact. Venting gas is released to the outside to prevent secondary damage.

According to this prior art, the safety of the battery cell can be increased by releasing the venting gas when the venting gas is generated, but the sealing of the pouch case 10 is not formed in the portion where the notch 41 is formed, so the holding force of the sealing can be reduced. there is

Korean Patent Publication No. 2006-0112035

In order to solve the above problems, in the present invention, a battery cell with improved safety capable of maintaining an appropriate level of sealing strength when the battery cell operates normally and discharging venting gas when high-temperature heat and gas is generated, and It is an object to provide a battery module including this.

In addition, an object of the present invention is to provide a battery cell capable of inducing emission of venting gas in a desired direction and a battery module including the same.

In order to achieve the above object, a battery cell having a venting gas induction unit in a lead film according to the present invention is a case made of a laminate sheet including an inner resin layer 110, a metal layer 120, and an outer resin layer 130. (100); an electrode assembly 200 accommodated in the case 100; an electrode tab 300 positioned on a side of the electrode assembly 200; an electrode lead 400 having one side connected to the electrode tab 300 and the other side protruding outward from the case 100; and a lead film 500 provided on upper and lower surfaces of the electrode lead 400, wherein at least one fusion part 510 having a pattern shape is formed in the lead film 500.

In addition, in the battery cell according to the present invention, the melting portion 510 is characterized in that the width of the lead film 500 becomes narrower toward the outer direction from the inner edge of the lead film 500 .

In addition, in the battery cell according to the present invention, the melting temperature of the melting part 510 is lower than the melting temperature of the lead film 500 .

In addition, in the battery cell according to the present invention, the melting portion 510 is characterized in that the thermoplastic material.

Also, in the battery cell according to the present invention, the fusion part 510 is characterized in that it is a material having chemical resistance.

In addition, in the battery cell according to the present invention, the melting unit 510 is polyimide, polypropylene, polyethylene, polyethylene terephthalate and polyvinyl chloride, and It is characterized by including any one or more of high density polyethylene.

In addition, in the battery cell according to the present invention, the melting portion 510 is characterized in that a plasticizer is added.

In addition, in the battery cell according to the present invention, the shape is characterized in that a triangle.

In addition, in the battery cell according to the present invention, the shape is characterized in that the semicircular.

In addition, in the battery cell according to the present invention, the shape is characterized in that the trapezoid.

In addition, the present invention may be a battery module including a battery cell having the above-described characteristics.

In addition, the present invention may be a battery pack including the battery module described above.

As described above, according to the battery cell having the venting gas induction part in the lead film according to the present invention and the battery module including the same, the melting part having a relatively lower melting temperature than the lead film is formed in the lead film, so that the inside of the case It has the advantage of being able to quickly release the venting gas when high-temperature heat and venting gas are generated.

In addition, according to the battery cell and battery module in which the venting gas induction part is provided in the lead film according to the present invention, since the melting part is provided near the electrode lead so that the venting gas does not go to the nearby battery cell, damage caused by the venting gas can be minimized. There is an advantage to being

1 is a perspective view showing a battery cell according to the prior art.
2 is a view from above of a battery cell according to a first preferred embodiment of the present invention.
FIG. 3 is a cross-sectional view taken along the line A-A' of FIG. 2 in the vertical direction.
FIG. 4 is an enlarged perspective view of a lead film positioned in close contact with an electrode lead in the battery cell of FIG. 2 .
5 is a top view of a battery cell according to a second preferred embodiment of the present invention.
6 is a view from above of a battery cell according to a third preferred embodiment of the present invention.

Hereinafter, an embodiment in which a person skilled in the art can easily practice the present invention will be described in detail with reference to the accompanying drawings. However, in the detailed description of the operating principle of the preferred embodiment of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted.

In addition, the same reference numerals are used for parts having similar functions and actions throughout the drawings. Throughout the specification, when a part is said to be connected to another part, this includes not only the case where it is directly connected, but also the case where it is indirectly connected with another element interposed therebetween. In addition, including a certain component does not exclude other components unless otherwise stated, but means that other components may be further included.

Hereinafter, a battery cell having a venting gas induction unit in a lead film according to the present invention and a battery module including the same will be described with reference to the accompanying drawings.

2 is a view from above of a battery cell according to a first preferred embodiment of the present invention, FIG. 3 is a cross-sectional view showing a state cut in the vertical direction along line A-A' of FIG. 2, and FIG. 4 is a view of FIG. It is an enlarged perspective view of a lead film positioned in close contact with an electrode lead in a battery cell.

2 to 4, the battery cell according to the present invention includes a case 100, an electrode assembly 200, an electrode tab 300, an electrode lead 400, and a lead film 500. It consists of

First, the case 100 may be composed of an upper case and a lower case, and may include a pocket-shaped space for accommodating the electrode assembly 200 .

The case 100 uses a laminate sheet composed of an inner resin layer 110, a metal layer 120, and an outer resin layer 130 to form a space portion capable of accommodating the electrode assembly 200.

Since the inner resin layer 110 is in direct contact with the electrode assembly 200, it must have insulation and electrolytic resistance, and also has excellent heat sealing strength for sealing with the outside, that is, the sealing area where the inner layers are thermally bonded to each other. should have

Materials for the inner coating layer 110 include polyolefin-based resins such as polypropylene, polyethylene, polyethylene acrylic acid, and polybutylene, which have excellent chemical resistance and good sealing properties; It may be selected from polyurethane resins and polyimide resins, but is not limited thereto, and polypropylene excellent in chemical resistance and mechanical properties such as tensile strength, rigidity, surface hardness, and impact resistance is most preferred.

The metal layer 120 in contact with the inner resin layer 110 corresponds to a barrier layer that prevents moisture or various gases from penetrating into the battery from the outside. A preferred material for this metal layer is an aluminum thin film that is lightweight and has excellent moldability. can be used

In addition, an external resin layer 130 is provided on the other side of the metal layer 120, and the external resin layer 130 protects the electrode assembly 200 and has tensile strength and moisture permeability to secure heat resistance and chemical resistance. and a heat-resistant polymer having excellent air permeation resistance, for example, nylon or polyethylene terephthalate, but is not limited thereto.

The electrode assembly 200 accommodated in the case 100 is a jelly-roll type electrode assembly having a structure in which a separator is interposed between a long sheet-shaped negative electrode and a positive electrode and then wound up, or a rectangular positive electrode and negative electrode with a separator interposed therebetween. A stack-type electrode assembly composed of unit cells in a stacked structure, a stack-folding type electrode assembly in which unit cells are wound by a long separation film, or unit cells are stacked with a separator interposed therebetween and mutually interact with each other. It may be made of an attached lamination-stack type electrode assembly or the like, but is not limited thereto.

Specifically, the negative electrode is manufactured by applying a slurry in which a negative electrode active material and a binder are mixed to a negative electrode current collector.

Here, examples of the negative electrode active material include carbon such as non-graphitizable carbon and graphite-based carbon; Li _x Fe ₂ O ₃ (0≤x≤1), Li _x WO ₂ (0≤x≤1), Sn _x Me _1-x Me'yOz (Me: Mn, Fe, Pb, Ge; Me': Al , B, P, Si, elements of groups 1, 2, and 3 of the periodic table, halogens; 0<x≤1;1≤y≤3;1≤z≤8); lithium metal; lithium alloy; silicon-based alloys; tin-based alloys; SnO, SnO ₂ , PbO, PbO ₂ , Pb ₂ O ₃ , Pb ₃ O ₄ , Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O ₅ , GeO, GeO ₂ , Bi ₂ O ₃ , Bi ₂ O ₄ , metal oxides such as Bi ₂ O ₅ ; conductive polymers such as polyacetylene; Li-Co-Ni based materials; Si, SiO, SiO ₂ Alone or a mixture thereof, such as Si-based, may be used, but is not limited to these.

The positive electrode is manufactured by applying a slurry in which a positive electrode active material and a binder are mixed to a positive electrode current collector.

Examples of the cathode active material include layered compounds such as lithium cobalt oxide (LiCoO2) and lithium nickel oxide (LiNiO2), or compounds substituted with one or more transition metals; lithium manganese oxides such as Li _1+x Mn _2-x O ₄ (where x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , LiMnO ₂ ; lithium copper oxide (Li ₂ CuO ₂ ); vanadium oxides such as LiV ₃ O ₈ , LiFe ₃ O ₄ , V ₂ O ₅ , and Cu ₂ V ₂ O ₇ ; Ni site type lithium nickel oxide represented by the formula LiNi _1-x M _x O ₂ , where M = Co, Mn, Al, Cu, Fe, Mg, B or Ga, and x = 0.01 to 0.3; Formula LiMn _2-x M _x O ₂ where M = Co, Ni, Fe, Cr, Zn or Ta and x = 0.01 to 0.1 or Li ₂ Mn ₃ MO ₈ where M = Fe, Co, Ni, Cu or Zn) lithium manganese composite oxide; LiMn ₂ O ₄ in which Li part of the formula is substituted with an alkaline earth metal ion; disulfide compounds; Fe ₂ (MoO ₄ ) ₃ etc. are mentioned, but it is not limited only to these.

On the other hand, the negative electrode current collector and the positive electrode collector are composed of a portion coated with a slurry mixed with an active material and a non-coated portion where the slurry is not applied. A tab 300 is formed.

An electrode lead 400 is connected to the electrode tab 300 by spot welding or the like, and a lead film 500 is positioned around the electrode lead 400 .

Here, the lead film 500 is located in a sealing portion where the lower case and the upper case are heat-sealed to fix the electrode lead 400 to the case 100 .

Thus, the lead film 500 prevents electricity generated from the electrode assembly 200 from flowing to the case 100 through the electrode lead 400 and maintains the sealing of the case 100 .

On the other hand, the lead film 500 is preferably made of a non-conductive material that does not conduct electricity well, and generally uses an insulating tape that is easy to attach to the electrode lead 400 and has a relatively thin thickness, but is not limited thereto.

Specifically, the lead film 500 is polyimide (PI: polyimide), polypropylene (PP: polypropylene), polyethylene (PE: polyethylene), polyethylene terephthalate (PET: polyethylene terephthalate) and polyvinyl chloride (PVC: polyvinyl chloride). It is composed of any one or two or more materials selected from the group consisting of , high density polyethylene (HDPE), and epoxy resin, and is thermally fused with the inner resin layer 110 of the battery case through heat and pressure. are glued

The lead film 500 includes a melting portion 510 having a shape in which the width decreases from the inner edge of the lead film 500 toward the outer direction. Specifically, the lead film 500 has a narrower width toward the outer direction from the inner edge A melting portion 510 having a triangular shape is provided.

The melting part 510 maintains the sealing state of the electrode lead 400 and the case 100 when the battery cell operates normally, but when gas is generated with high temperature heat from the battery cell, it is preferentially melted and venting gas It acts as a channel for excretion.

Therefore, the melting temperature of the melting part 510 is lower than the melting temperature of the lead film 500 and may be a chemical resistant material or a thermoplastic resin.

That is, polyimide, polypropylene, polyethylene, polyethylene terephthalate, and polyvinyl chloride, which are the same materials as the lead film 500, and high density polyethylene polyethylene).

For example, when polypropylene is used as a material for the lead film 500, considering that the commonly known melting temperature of polypropylene is 160°C, the melting part 510 has a melting temperature of approximately 120°C. Polyethylene corresponding to the vicinity and high density polyethylene having a melting temperature of about 135° C. can be used.

Of course, it is not limited to the above case, and when the material of the melting unit 510 is changed, the melting unit 510 is not particularly limited as long as the material is lower than the melting temperature of the corresponding lead film 500 .

Meanwhile, the melting unit 510 may be made of the same material as the lead film 500 . However, in the case of the same material, it is good to add a certain amount of a phthalate-based plasticizer to relatively lower the melting temperature of the melting unit 510, and adjusting the melting temperature through the addition of such a plasticizer is a known technology, so specific description will be omitted.

When the lead film 500 having the fusion part 510 as described above is placed in contact with the electrode lead 400, the part where the fusion part 510 is formed among the sealing parts provided along the edge of the case 100 melts first.

Accordingly, when an event occurs in a specific battery cell, the venting gas can be rapidly released, thereby preventing secondary accidents such as explosions. In addition, in a battery module in which a plurality of battery cells are arranged side by side, since the discharge direction of the venting gas is toward the electrode lead 400, the venting gas is not directed to the battery cells located nearby, and thus the safety of the battery module can be increased. there is

5 is a top view of a battery cell according to a second preferred embodiment of the present invention. Referring to FIG. 5, since the battery cell according to the second embodiment of the present invention is the same as the first embodiment described in FIGS. 2 to 4 except for the shape of the melting part 510, the same configuration Description is omitted.

In the battery cell according to the second preferred embodiment of the present invention, the melting unit 510 has a semicircular shape.

Although the fusion part 510 is shown in a semi-circular shape in FIG. 4 , it may also have a semi-elliptical shape, and it is not limited thereto as long as the width decreases from the inner edge of the lead film 500 toward the outer side.

6 is a view from above of a battery cell according to a third preferred embodiment of the present invention. Referring to FIG. 6, since the battery cell according to the third preferred embodiment of the present invention is the same as the first embodiment described in FIGS. 2 to 4 except for the shape of the melting part 510, the same configuration Description will be omitted.

In the battery cell according to the third preferred embodiment of the present invention, the melting part 510 has a trapezoidal shape.

In addition, the present invention may be a battery module including the battery cell described above, and may be a battery pack including the battery module described above.

Those skilled in the art to which the present invention pertains will be able to perform various applications and modifications within the scope of the present invention based on the above information.

100: case
110: inner resin layer
120: metal layer
130: external resin layer
200: electrode assembly
300: electrode tab
400: electrode lead
500: lead film
510: melting part

Claims (12)

A case made of a laminate sheet including an inner resin layer, a metal layer, and an outer resin layer;
an electrode assembly accommodated in the case;
an electrode tab positioned on a side of the electrode assembly;
an electrode lead having one side connected to the electrode tab and the other side protruding out of the case; and
Including a lead film provided on the upper and lower surfaces of the electrode lead,
A battery cell, characterized in that at least one molten portion having a pattern shape is formed on the lead film. According to claim 1,
The battery cell, characterized in that the melting portion has a shape in which the width becomes narrower toward the outer direction from the inner edge of the lead film. According to claim 2,
The battery cell, characterized in that the melting temperature of the melting portion is lower than the melting temperature of the lead film. According to claim 3,
The battery cell, characterized in that the melting portion is a thermoplastic material. According to claim 3,
The battery cell, characterized in that the melting portion is a material having chemical resistance. According to claim 3,
The melting unit includes at least one of polyimide, polypropylene, polyethylene, polyethylene terephthalate and polyvinyl chloride, and high density polyethylene A battery cell characterized in that to do. According to claim 6,
The battery cell, characterized in that the melting portion is added to the plasticizer. According to claim 2,
The battery cell, characterized in that the shape is a triangle. According to claim 2,
The battery cell, characterized in that the shape is semicircular. According to claim 2,
The battery cell, characterized in that the shape is trapezoidal. A battery module comprising the battery cell according to any one of claims 1 to 10. A battery pack comprising the battery module according to claim 11.

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