KR20170055439A - Pouch type secondary battery and method of making the same - Google Patents

Abstract

The present invention relates to a pouch type secondary battery and a manufacturing method thereof. The pouch type secondary battery forms a sealing unit by being bonded with a non-heating method since metal layers, which are the edge of a laminate sheet of each of upper and lower pouches, face each other. Since a sealing unit of an external circumferential surface of the pouch is formed by bonding the metal layer, a possibility of moisture penetration from the outside and a possibility of electrolyte leakage in a battery can be lower or prevented.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a pouch type secondary battery,

The present invention relates to a pouch-type secondary battery and a method of manufacturing the same, and more particularly, to a pouch-type secondary battery in which a metal layer of an edge portion of a laminate sheet constituting an upper pouch and a lower pouch are bonded to each other in a non- And a manufacturing method thereof.

As technology development and demand for mobile devices have increased, there has been a rapid increase in the demand for secondary batteries as an energy source. Many researches have been made on lithium secondary batteries having high energy density and discharge voltage among these secondary batteries, .

The lithium secondary battery is classified into a cylindrical battery, a prismatic battery, a pouch-type battery, and the like depending on the outer shape thereof, and may be classified into a lithium ion battery, a lithium ion polymer battery, and a lithium polymer battery depending on the type of electrolyte.

Due to recent trend toward miniaturization of mobile devices, there is a growing demand for thin rectangular prismatic batteries and pouch-type cells, and particularly for pouch-type cells which are easy to deform in shape, low in manufacturing cost, Interest is high.

In general, a pouch-type battery is manufactured from a laminate sheet for a pouch including an inner resin layer, a metal layer, and an outer resin layer, and includes a housing space in which an electrode assembly and an electrolyte solution are accommodated, and a sealing part sealed around the housing space. . The electrode assembly housed in the storage space may be a jelly-roll (wound type) electrode assembly, a stacked (laminated) electrode assembly, or a composite (stacked / folded) electrode assembly.

1 is an exploded perspective view schematically showing a configuration of a general pouch type secondary battery. Referring to FIG. 1, a pouch type secondary battery includes an electrode assembly 10 and a pouch 20 as a basic structure.

The electrode assembly 10 may include a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode to electrically insulate the positive electrode from the negative electrode. And a negative electrode tab extending from the negative electrode.

Each of the positive electrode tab and the negative electrode tab may be joined to the positive electrode lead 11 and the negative electrode lead 12 by resistance welding, ultrasonic welding, laser welding or the like. The electrode lead is exposed to the outside of the pouch, The secondary battery and the external application device are electrically connected to each other.

The electrode assembly 10 is put into a pouch 20 for a secondary battery together with an electrolyte including an electrolyte.

The secondary battery pouch 20 may be divided into an upper case 21 and a lower case 22 and may be referred to as a single cap or a double cap depending on the storage space of the electrode assembly 10. A portion of the pouch for a secondary battery which is sealed around the storage space is referred to as a " sealing portion ", and in particular, an edge portion where the electrode tab and / or electrode lead is disposed in the pouch edge portion is referred to as a " terrace portion ".

The secondary battery pouch 20 may be composed of a laminated sheet having a metal layer interposed therebetween in order to protect the electrolyte solution and the electrode assembly 10 introduced into the battery cell and to improve the electrochemical properties of the battery cell and to improve heat dissipation have. An outer resin layer coated with an insulating material such as polyethylene terephthalate (PET) resin or nylon resin may be formed on the outer side of the metal layer in order to ensure insulation between the battery cell and the outside. An inner resin layer including a lead-free polypropylene (CPP) or polypropylene (PP) may be formed on the lower surface of the upper case 21 and the upper surface of the lower case 22 have. The inner resin layer serves not only to bond the outer circumferential surface of the upper case 21 and the outer circumferential surface of the lower case 22, but also to prevent the conductivity between the metal layer and the electrolyte injected into the pouch 20.

2 is an enlarged cross-sectional view of part A and part B in Fig. 2, the upper case 21 has a predetermined layered structure in the order of the outer resin layer 25, the metal layer 24, and the inner resin layer 23 from above, The inner resin layer 23, the metal layer 24, and the outer resin layer 25 as shown in FIG. The upper case 21 and the lower case 22 may be thermally fused at the outer circumferential surface to form a sealing portion. As a method of forming the sealing portion, a sealing portion of the upper case 21 and the lower case 22 is thermocompression-bonded using a bar-type sealing tool as shown in Fig. 3 The method is known.

4 schematically shows the cross section of each of the laminate sheet 421 of the upper case and the laminate sheet 422 of the lower case before sealing and the right side of Fig. And schematically showing the cross section of the laminated sheet after the laminate sheet of the upper case and the laminate sheet of the lower case are fused with a sealing tool.

4, the laminate sheet 421 of the upper case includes the outer resin layer 425, the metal layer 422, and the inner resin layer 423 in order from the top, and the laminate sheet 422 of the lower case, An inner resin layer 423, a metal layer 422, and an outer resin layer 425 in this order from the top. After the sealing tool is applied, the inner resin layer 423 is fused to face to face, and the metal layer 424 and the outer resin layer 425 are laminated on the inner resin layer 423 as the center. 4 and 4, the thickness of the laminate sheet for pouch is generally thin after the sealing tool is applied, but the outer resin layer 25, the metal layer 24 and the inner resin layer 23 are still thin Layer structure is maintained.

On the other hand, the cross section of the inner resin layer constituting the pouch for the secondary battery is exposed to the outside of the pouch even after sealing. Since the inner resin layer is mainly made of the polymer resin material, the water penetration can easily occur through the cross section of the inner resin layer in spite of fusion of the upper case and the lower case, and there is a possibility of electrolyte leakage. Such moisture permeability and possibility of leakage of the electrolyte act as a factor that hinders the life and stability of the battery when the battery is used over a long period of time.

Accordingly, it is necessary to develop a pouch for a secondary battery that can suppress moisture penetration and prevent electrolyte leakage.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and the technical problems required from the past.

It is an object of the present invention to provide a pouch for a secondary battery and a pouch-type secondary battery including the pouch having a sealing part having a specific structure capable of greatly improving the water resistance and durability of the pouch for the secondary battery.

Another object of the present invention is to provide a method for improving the sealing property of the sealing part without damaging the pouch laminate film.

According to one aspect of the present invention, there is provided a pouch for a secondary battery comprising an upper pouch and a lower pouch formed of a laminate sheet including an outer resin layer, a metal layer, and an inner resin layer, wherein a metal layer of the laminate sheet of the upper pouch and the lower pouch, There is provided a pouch for a secondary battery which is bonded in a non-heating manner to face each other to form a sealing portion. At this time, a terrace portion is not included in the sealing portion.

The metal layer may be formed of aluminum.

The thickness of the pouch sealing portion may become thinner toward the outside.

The upper pouch and the lower pouch bonded by the metal layer may be surrounded by an inner resin layer.

According to another aspect of the present invention, there is provided a pouch-type secondary battery in which an electrode assembly including an anode, a cathode, and a separator interposed between the anode and the cathode, and an electrolyte are accommodated in the pouch for the secondary battery, / RTI >

The pouch type secondary battery may be a lithium secondary battery.

According to another aspect of the present invention, there is provided a method of manufacturing an electrode assembly, comprising the steps of: preparing an upper pouch and a lower pouch each formed of a laminate sheet including an outer resin layer, a metal layer, and an inner resin layer; And a step of bonding the laminate sheet metal layer to the pouch edge portion in a non-heat-type manner facing each other, and a method for manufacturing the pouch for a secondary battery.

At the edge portion of the pouch excluding the terrace portion, the metal layer constituting the laminate sheet may extend to the outside of the inner resin layer.

The upper pouch and the portion to be sealed at the lower pouch may be fused by a sealing tool of the bar-shaped bar prior to joining the metal layer.

The joining may be performed by solid-state welding such as friction stir welding or cold welding.

The sealing tool may be a sealing tool that forms a thinner thickness toward the outside of the pouch sealing portion.

The pouch for a secondary battery according to the present invention is formed by bonding the metal layers of the upper pouch and the lower pouch in a non-heated manner, so that the pouch sealing part can be formed without damaging the laminate sheet, and the possibility of moisture permeation from the outside and electrolyte leakage of the battery are lower It can be prevented or prevented.

As a result, the life of the battery is prolonged and the safety of the battery is improved.

1 is a schematic view of a conventional pouch type secondary battery.
2 is a view schematically showing the structure of a laminated sheet constituting the pouch for the secondary battery of FIG.
FIG. 3 is a schematic view of a conventional method for fusing a portion to be sealed at an upper pouch and a lower pouch using a sealing tool.
Fig. 4 is a schematic view showing general aspects before and after fusion of a laminate sheet of an upper pouch and a laminate sheet of a lower pouch.
5 is a schematic view of a laminate sheet of an upper pouch and a laminate sheet of a lower pouch according to an embodiment of the present invention, together with a sealing tool applicable thereto.
6 is a schematic view of a laminate sheet of an upper pouch and a laminate sheet of a lower pouch according to another embodiment of the present invention, together with a sealing tool applicable thereto.
7 is a schematic cross-sectional view of a pouch sealing portion for a secondary battery according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately It should be interpreted in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined.

Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

According to one aspect of the present invention, in a pouch for a secondary battery including an upper pouch and a lower pouch formed of a laminate sheet including an outer resin layer, a metal layer, and an inner resin layer, the upper pouch and the lower pouch The metal layer of the laminate constituting the laminate is bonded to each other in a non-heating manner, the inner resin layer does not exist in the sealing portion, and since the sealing tool is applied, the metal layer becomes thinner toward the outside of the sealing portion. The upper pouch and the lower pouch may be separated from each other or may be connected to one side.

Referring to FIG. 7, a pouch for a secondary battery according to an embodiment of the present invention will be described. The thickness of the pouch sealing portion decreases toward the outside. In addition, the end surface of the pouch sealing portion is composed of a metal layer or a metal layer and an outer resin layer, and the inner resin layer 723 is present inside the bonded metal layer and is not exposed to the outside. Therefore, it is possible to prevent the external moisture from penetrating into the battery through the cross section of the inner resin layer 723, and also to prevent the electrolyte from leaking to the outside through the inner resin layer 723. On the other hand, since the metal layer of the laminated film is brought into contact with the electrolytic solution, it is desirable to further secure the sealing property of the bonded metal layer.

The metal that can be used as the metal layer in the present invention is a metal that can be used in the art to secure the mechanical strength of the pouch outer cover material and to prevent the gas, moisture and the like outside the secondary battery from flowing into the secondary battery. It does not. Non-limiting examples of the metal include aluminum. In the case of aluminum, it is advantageous in that it can secure a mechanical strength of a predetermined level or more, yet it is light in weight, and it is advantageous to improve the electrochemical properties due to the electrode assembly and the electrolytic solution, and to improve the heat dissipation. However, the present invention is not limited thereto, and various materials other than aluminum may be used as a metal layer. The thickness of the metal layer is not particularly limited, but may be 20 to 100 占 퐉 in consideration of the welding processability and the ability to inhibit moisture permeation.

The outer resin layer is made of a material having electrical insulation and is provided outside the metal layer so as to protect the electrode assembly from external substances and electrically insulate the electrode assembly and the metal layer from the outside.

Non-limiting examples of materials that may be used as the outer resin layer include but are not limited to polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymers, polyacrylonitrile, polyimide, polyamide, cellulose, , Oriented Nylon. And at least one material selected from the group consisting of polyester, polyparaphenylene benzobisoxazole, polyarylate, Teflon, and glass fiber. The outer resin layer may have a single film structure made of any one material or a composite film structure in which two or more materials are respectively formed in layers.

The inner resin layer is formed inside the metal layer so that the metal layer and the electrode assembly or the metal layer and the electrolyte can be electrically insulated.

Non-limiting examples of materials that can constitute the inner resin layer include polyethylene, polypropylene, casted polypropylene (CPP), polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymer, polyacrylonitrile, Polyamide, polyamide, cellulose, aramid, nylon, polyester, polyparaphenylene benzobisoxazole, polyarylate, teflon, and glass fiber. The inner resin layer may have a single film structure composed of any one material, or may have a composite film structure in which two or more materials are respectively formed of layers.

One embodiment of a method of forming a pouch sealing portion according to the present invention is shown in Fig. 5, the laminate sheet of each of the upper pouch and the lower pouch includes an inner resin layer 523, a metal layer 524 and an outer resin layer 525, and the metal layer 524 is formed to be longer than the inner resin layer As shown in Fig. The length of the metal layer extending to the outside longer than the inner resin layer is not particularly limited as long as the intermetallic bonding can be ensured. However, it may be preferable that the metal layer and the inner resin layer are terminated at the same end in order to secure safety in the pouch terrace portion. The laminate sheet may be fused, if necessary, by a rod-shaped sealing tool as shown in Fig. The sealing tool can be applied, for example, at a temperature of 25 to 500 DEG C or a pressure of 1.0 MPa or less, or in the temperature range and the pressure range, but is not limited thereto. For example, it can be fused at room temperature only by pressure without a heating process.

Another embodiment of a method of forming a pouch sealing portion according to the present invention is shown in Fig. 6, the laminate sheet of each of the upper pouch and the lower pouch includes an inner resin layer 623, a metal layer 624, and an outer resin layer 625, and the metal layer and the inner resin layer are terminated at the same end . In this case, since it is difficult to apply the non-heating type bonding in the structure in which the inner resin layer is bonded, in the present invention, the inner resin layer is pushed into the sealing part by a sealing tool or the like, As shown in FIG. To this end, a sealing tool may be applied that allows for the formation of a thinner thickness sealing portion outside the pouch sealing portion, for example, a seal of the type described in FIG. 6, such that more pressure is applied to the outside of the pouch sealing portion, Tools can be applied. The sealing tool can be applied, for example, at a temperature of 25 to 500 DEG C or a pressure of 1.0 MPa or less, or in the temperature range and the pressure range, as described above, but is not limited thereto.

Then, the upper pouch and the lower pouch edge are pressed together by a method of bonding the metal layer of the laminate sheet in a non-heated manner. In the present specification, the term 'non-heat-joining' refers to joining that strongly pressurizes materials at room temperature to induce local press-contact, and preferably solid-state welding methods such as cold-pressing and friction stir welding have. This is because when a metal layer is bonded by a method such as resistance welding or ultrasonic welding, there is a high possibility that a defect occurs in a welded portion, and a welded portion may be dropped due to vibration of an external impact. On the other hand, in the case of joining in the same manner as cold welding or friction stir welding, the metal layer can be stably bonded. In particular, friction stir welding is eco-friendly welding in which harmful rays and harmful substances are not discharged during the welding process because a heat source, a welding rod, and a charging agent are unnecessary compared with other welding. In addition, since dynamic recombination occurs, solidification cracks which may occur in the fusion bonding can be prevented, and there is almost no deformation, which is advantageous in that the mechanical properties are excellent.

Inside the pouch for a secondary battery formed of the laminate sheet, an electrode assembly and an electrolyte including an anode, a cathode, and a separator interposed between the anode and the cathode may be accommodated.

The positive electrode includes a positive electrode active material and a positive electrode collector, and the negative electrode includes a negative electrode active material and a negative electrode collector.

The positive electrode may be prepared by applying a mixture of a positive electrode active material, a conductive material and a binder on a positive electrode current collector, followed by drying. If necessary, a filler may be further added to the mixture.

The cathode active material may be a layered compound such as lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), or a compound substituted with a transition metal or higher; 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 and LiMnO ₂ ; Lithium copper oxide (Li ₂ CuO ₂ ); Vanadium oxides such as LiV ₃ O ₈ , V ₂ O ₅ and Cu ₂ V ₂ O ₇ ; Formula _{LiNi 1 - x M x O 2} ( where, the M = Co, Mn, Al, Cu, Fe, Mg, B or Ga, x = 0.01 ~ 0.3 Im) Ni site type lithium nickel oxide which is represented by; Formula _{LiMn 2 - x M x O 2} ( where, M = Co, Ni, Fe , Cr, and Zn, or Ta, x = 0.01 ~ 0.1 Im) or Li ₂ Mn ₃ MO ₈ (where, M = Fe, Co, Ni, Cu, or Zn); LiMn ₂ O _{4 in} which a part of Li in the formula is substituted with an alkaline earth metal ion; Disulfide compounds; Fe ₂ (MoO ₄ ) ₃ , and the like. However, the present invention is not limited to these.

The cathode current collector generally has a thickness of 3 to 500 mu m. Such a positive electrode current collector is not particularly limited as long as it has high conductivity without causing chemical change in the battery, and may be formed of a material such as stainless steel, aluminum, nickel, titanium, sintered carbon, or a surface of aluminum or stainless steel Treated with carbon, nickel, titanium, silver or the like may be used. The current collector may have fine irregularities on the surface thereof to increase the adhesive force of the cathode active material, and various forms such as a film, a sheet, a foil, a net, a porous body, a foam, and a nonwoven fabric are possible.

The binder is a component that assists in binding of the active material to the conductive material and bonding to the current collector, and is usually added in an amount of 1 to 50 wt% based on the total weight of the positive electrode mixture. As such a binder, a high molecular weight polyacrylonitrile-acrylic acid copolymer can be used, but the present invention is not limited thereto. Other examples include polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, Polypropylene, ethylene-propylene-diene monomer (EPDM), sulfonated EPDM, styrene butadiene rubber, fluorine rubber, various copolymers and the like.

The conductive material may be added in an amount of 1% by weight to 50% by weight based on the total weight of the anode mixture, which is conductive without causing chemical changes in the battery. For example, graphite such as natural graphite or artificial graphite; Carbon black such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and summer black; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskey such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; And conductive polymers such as polyphenylene derivatives can be used. The positive electrode may optionally contain a filler as a component for suppressing expansion.

The filler is not particularly limited as long as it is a fibrous material that does not cause chemical changes in the battery, and examples thereof include olefin polymers such as polyethylene and polypropylene; Fibrous materials such as glass fibers and carbon fibers are used.

The negative electrode can be obtained by applying a mixture containing a negative electrode active material, a binder and a conductive material to a current collector, followed by drying the solvent.

Examples of the negative electrode active material include carbon and graphite materials such as natural graphite, artificial graphite, expanded graphite, carbon fiber, non-graphitizable carbon, carbon black, carbon nanotube, fullerene and activated carbon; Metals such as Al, Si, Sn, Ag, Bi, Mg, Zn, In, Ge, Pb, Pd, Pt and Ti which can be alloyed with lithium and compounds containing these elements; Complex compounds of metals and their compounds and carbon and graphite materials; Lithium-containing nitrides, and the like.

And may further include a conductive material and / or a filler as a component for improving the conductivity of the negative electrode active material. The conductive material and the filler are the same as those described above with respect to the anode.

The negative electrode collector may typically be made to a thickness of about 3 to 500 [mu] m. Such an anode current collector is not particularly limited as long as it has electrical conductivity without causing a chemical change in the battery. For example, the anode current collector may be formed on the surface of copper, stainless steel, aluminum, nickel, titanium, fired carbon, copper or stainless steel Carbon, nickel, titanium, silver or the like, an aluminum-cadmium alloy, or the like can be used. In addition, like the positive electrode collector, fine unevenness can be formed on the surface to enhance the bonding force of the negative electrode active material, and it can be used in various forms such as films, sheets, foils, nets, porous bodies, foams and nonwoven fabrics.

The separator is interposed between the positive electrode and the negative electrode, and an insulating thin film having high ion permeability and mechanical strength is used. The pore diameter of the separator is generally 0.01 to 10 mu m and the thickness is generally 5 to 300 mu m. As such a separator, for example, an olefin-based polymer such as polypropylene having chemical resistance and hydrophobicity; A sheet or nonwoven fabric made of glass fiber, polyethylene, or the like can be used. When a solid electrolyte such as a polymer is used as the electrolyte, the solid electrolyte may also serve as a separator.

The separator preferably has a weight average molecular weight within a range of 1,000 to 20,000. Outside of the above molecular weight range, it may be difficult to ensure proper tensile strength and elongation.

The pouch type secondary battery according to the present invention may further include a lithium salt-containing non-aqueous electrolyte in addition to the positive electrode, the negative electrode and the separator.

The lithium salt-containing non-aqueous electrolyte is composed of a nonaqueous electrolyte and lithium.

As the non-aqueous electrolyte, a non-aqueous electrolyte, an organic solid electrolyte, an inorganic solid electrolyte and the like may be used.

Examples of the nonaqueous electrolytic solution include N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma-butylolactone, Dimethylformamide, dioxolane, acetonitrile, nitromethane, methyl formate, methyl acetate, phosphoric acid triester < RTI ID = 0.0 > , Trimethoxymethane, dioxolane derivatives, sulfolane, methylsulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate derivatives, tetrahydrofuran derivatives, ether, methyl propionate and ethyl propionate An aprotic organic solvent may be used.

Examples of the organic solid electrolyte include a polymer electrolyte such as a polyethylene derivative, a polyethylene oxide derivative, a polypropylene oxide derivative, a phosphate ester polymer, an agitation lysine, a polyester sulfide, a polyvinyl alcohol, a polyvinylidene fluoride, Polymers containing ionic dissociation groups, and the like can be used.

Examples of the inorganic solid electrolyte include Li ₃ N, LiI, Li ₅ NI ₂ , Li ₃ N-LiI-LiOH, LiSiO ₄ , LiSiO ₄ -LiI-LiOH, Li ₂ SiS ₃ , Li ₄ SiO ₄ , Nitrides, halides and sulfates of Li such as Li ₄ SiO ₄ -LiI-LiOH and Li ₃ PO ₄ -Li ₂ S-SiS ₂ can be used.

The lithium salt is a material that is readily soluble in the non-aqueous electrolyte, for example, LiCl, LiBr, LiI, LiClO 4, LiBF 4, LiB 10 Cl 10, LiPF 6, LiCF 3 SO 3, LiCF 3 CO 2, LiAsF _{6, LiSbF 6, LiAlCl 4,} CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2) ₂ NLi, may be used, such as chloroborane lithium, lower aliphatic carboxylic acid lithium, lithium tetraphenyl borate.

For the purpose of improving charge / discharge characteristics, flame retardancy, etc., non-aqueous electrolytes may be used in the form of, for example, pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, glyme, N, N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxyethanol, aluminum trichloride and the like are added It is possible. In some cases, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride may be further added to impart nonflammability, or a carbon dioxide gas may be further added to improve high-temperature storage characteristics.

The secondary battery according to the present invention can be preferably a lithium secondary battery, and is particularly applicable to a so-called lithium ion polymer battery in which a lithium-containing electrolyte is impregnated with an electrode assembly in the form of a gel.

In addition, the battery according to the present invention can be suitably used as a unit battery in a large-capacity large-capacity battery pack as well as a small-sized battery pack in a mobile device.

In addition, the present invention can provide a device including the battery pack as a power source, and more specifically, it can be a mobile electronic device.

Further, the battery pack of the present invention can be used as an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device in consideration of mounting efficiency, structural safety, and the like.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not to be limited to the details thereof and that various changes and modifications will be apparent to those skilled in the art. And various modifications and variations are possible within the scope of the appended claims.

Claims (12)

1. A pouch type secondary battery comprising an upper pouch formed of a laminate sheet including an outer resin layer, a metal layer and an inner resin layer, and a lower pouch,
Wherein a metal layer of the laminate sheet of each of the upper pouch and the lower pouch is bonded to each other in a non-heated manner to form a sealing part.
The method according to claim 1,
Wherein the metal layer is formed of aluminum.
The method according to claim 1,
And the thickness of the pouch sealing part decreases toward the outside.
The method according to claim 1,
Wherein the upper pouch and the lower pouch bonded by the metal layer are surrounded by an inner resin layer.
The method according to claim 1,
An electrode assembly comprising an anode, a cathode, and a separator interposed between the anode and the cathode, and an electrolytic solution contained therein.
The method according to claim 1,
Wherein the lithium secondary battery is a lithium secondary battery.
Preparing an upper pouch and a lower pouch each formed of a laminate sheet including an outer resin layer, a metal layer, and an inner resin layer; Storing the electrode assembly and the electrolyte in a pouch; And laminating the laminate sheet metal layer on the edge of the pouch in a non-
A method of manufacturing a pouch type secondary battery.
8. The method of claim 7,
Wherein the metal layer constituting the laminate sheet extends to the outside of the inner resin layer at the pouch edge portion excluding the terrace portion.
9. The method of claim 8,
Characterized in that prior to performing the bonding of the metal layer, the upper pouch and the part to be sealed of the lower pouch are fused by a sealing tool of the rod.
8. The method of claim 7,
Wherein the bonding is performed by friction stir welding or cold pressing.
10. The method of claim 9,
Wherein the sealing tool is a sealing tool that forms a thinner thickness toward the outside of the pouch sealing portion.
10. The method of claim 9,
Wherein the sealing tool is applied at a temperature of 25 to 500 DEG C, a pressure of 1.0 MPa or less, or in the temperature range and the pressure range.

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