Battery cartridge, battery cell including same, and method of manufacturing battery cell

Abstract

Disclosed are a battery cartridge, a battery cell including the battery cartridge, and a method of manufacturing the battery cell, the battery cartridge including: a first resin layer having a hot melt property; a metal layer having moisture barrier properties; a second resin layer configured to protect the internal component from external influence; and a heat dissipation layer including a carbon material and a binder, in which the heat dissipation layer is added to a surface of the second resin layer, and a thickness of the heat dissipation layer is 40 nm to 800 nm, thereby improving heat dissipation performance while minimizing a thickness increase of the battery cartridge.

Description

Technical Field

[0001] This application claims the benefit of priority to Korean Patent Application No. 2023-0132102, filed on October 4, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present invention relates to a pouch-shaped battery case including a carbon coating, a pouch-shaped battery cell including the same, and a method for manufacturing the pouch-shaped battery cell. More particularly, the present invention relates to a pouch-shaped battery case including such a carbon coating: the pouch-shaped battery case is capable of preventing the transfer of heat generated during the charging and discharging process, thereby preventing further fire and explosion. Background Art

[0003] Lithium secondary batteries, which are rechargeable and have high energy density, have attracted much attention as new energy sources with environmentally friendly characteristics, not only because they can significantly reduce the use of fossil fuels, but also because they do not generate byproducts due to the use of energy.

[0004] Lithium secondary batteries can be classified based on their shapes. Specifically, lithium secondary batteries can be divided into cylindrical battery cells manufactured by inserting an electrode assembly into a metal can, prismatic battery cells manufactured by inserting an electrode assembly into a metal can, and pouch-shaped battery cells manufactured by inserting an electrode assembly into a battery box made of a laminate sheet including a resin layer and a metal layer.

[0005] Among them, the pouch-shaped battery cell has the advantages of easy deformation and high energy density.

[0006] However, since the resin layer constituting the laminated sheet is made of a material such as nylon or polyethylene terephthalate that reduces heat dissipation performance, the resin layer has the disadvantage of being susceptible to the heating phenomenon that occurs during the charging and discharging of the secondary battery. In addition, as the temperature rises, the discharge amount increases, causing the usable time of the battery to decrease rapidly.

[0007] When the temperature of the battery cell exceeds the reference temperature due to the heating phenomenon of the secondary battery, the electrode assembly or the electrolyte decomposes, thereby generating a large amount of gas. The gas generated in the battery cell increases the internal pressure of the battery cell, thereby causing a swelling phenomenon in which the battery cell expands. Due to the swelling phenomenon, the size of the plurality of pouch-shaped battery cells arranged in the battery pack may change, thereby possibly deforming the packaging box.

[0008] Therefore, various methods have been tried to reduce the heating phenomenon of the pouch-shaped battery cells.

[0009] Patent document 1 relates to a packaging material for a pouch-shaped battery, which includes an outermost layer made of a heat-resistant resin, a barrier layer containing aluminum or an aluminum alloy, and an innermost layer made of a thermoplastic resin, wherein at least one of the layers constituting the packaging material includes a heat dissipation layer to which a carbon material is added or a separate additional heat dissipation layer containing a carbon material and a binder resin. In this configuration, when the temperature in a lithium secondary battery rises rapidly due to overcharging or an internal short circuit caused by an abnormal reaction in the battery, or when the battery is exposed to a high temperature environment, the carbon material dissipates the heat of the packaging material, thereby delaying and suppressing the internal temperature rise of the battery.

[0010] In Patent Document 1, a heat dissipation layer having a thickness of 1 μm or more is added to a packaging material, and measurement results of the degree to which the packaging material is cooled over time are disclosed.

[0011] Although Patent Document 1 shows that the thickness of the heat dissipation layer is proportional to the heat dissipation performance, there is a problem that when a thicker heat dissipation layer is used in order to improve the heat dissipation performance, the overall thickness of the packaging material is further increased.

[0012] Therefore, there is a need to develop a pouch-shaped battery case having improved heat dissipation characteristics while minimizing an increase in the thickness of the pouch-shaped battery case.

[0013] (Prior art literature)

[0014] (Patent Document 1) Korean Patent Application Publication No. 2013-0011977 (January 30, 2013) Summary of the invention

[0015] Technical issues

[0016] The present invention has been made in view of the above problems, and an object of the present invention is to provide a pouch-shaped battery case having minimized thickness increase and significantly improved heat dissipation performance, a pouch-shaped battery cell including the same, and a method of manufacturing the pouch-shaped battery cell.

[0017] Technical Solution

[0018] In order to achieve the above-mentioned purpose, the battery box according to the present invention includes: a first resin layer having hot-melt properties; a metal layer having moisture barrier properties; a second resin layer configured to protect internal components from external influences; and a heat dissipation layer comprising a carbon material and a binder, wherein the heat dissipation layer is added to the surface of the second resin layer, and the thickness of the heat dissipation layer is 40nm to 800nm.

[0019] In the battery case, the carbon material may be at least one selected from the group consisting of graphite, carbon nanotube (CNT), single-walled carbon nanotube (SWNT), graphene, and activated carbon fiber (ACF).

[0020] In the battery case, the carbon material may be graphene prepared using a liquid phase exfoliation method.

[0021] In the battery box, the thickness of the heat dissipation layer can be 80nm to 800nm.

[0022] In the battery case, the binder may be contained so as to account for 0.01 wt % to 5 wt % based on the total weight of solid contents.

[0023] In the battery case, the adhesive may be at least one selected from the following: an epoxy-based adhesive, an acrylic-based adhesive, a hydrocarbon-based adhesive, a polyester-based adhesive, a vinyl-based adhesive, a urethane-based adhesive, and an acrylate-based adhesive, or a copolymer containing the same.

[0024] In a battery cell including the battery box, an electrode assembly is accommodated in the battery box, a sealing portion is formed on the periphery of a cup portion configured to allow the electrode assembly to be accommodated therein, an electrode lead connected to an electrode tab of the electrode assembly extends outward from the sealing portion of the battery box, and a heat dissipation layer is provided on the outer surface of the battery box.

[0025] One embodiment of the method for manufacturing the battery cell includes: manufacturing a battery box made of a laminate sheet including a first resin layer, a metal layer and a second resin layer; preparing a solution for a heat dissipation layer including a carbon material and a binder; forming a heat dissipation layer on the battery box; and accommodating an electrode assembly in the battery box and sealing the battery box.

[0026] The step of forming the heat dissipation layer may be performed using a gravure coating method.

[0027] Another embodiment of the method for manufacturing the battery cell includes: preparing a battery box made of a laminate sheet including a first resin layer, a metal layer and a second resin layer; accommodating an electrode assembly in the battery box and sealing the battery box; preparing a solution for a heat dissipation layer including a carbon material and a binder; and forming a heat dissipation layer on the battery box.

[0028] In the method of manufacturing a battery cell, the step of forming the heat dissipation layer may be performed using a dip coating method.

[0029] Furthermore, the present invention can provide various combinations of the above-mentioned solving means.

[0030] Beneficial Effects

[0031] As is apparent from the above description, the battery case according to the present invention exhibits high heat dissipation performance even if the thickness of the heat dissipation layer is several tens to several hundreds of nanometers.

[0032] Furthermore, by reducing the thickness of the heat dissipation layer, manufacturing costs can be reduced, and by effectively managing heat, the risk of shortened product life, malfunction, and fire can be reduced.

[0033] In addition, energy density can be improved by minimizing the increase in battery case thickness. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 2 are a perspective view and a partial vertical cross-sectional view of a pouch-shaped battery cell according to the present invention. DETAILED DESCRIPTION

[0035] Now, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the preferred embodiments of the present invention. However, when describing in detail the operating principle of the preferred embodiments of the present invention, when the detailed description of known functions and configurations incorporated herein may obscure the subject matter of the present invention, these detailed descriptions will be omitted.

[0036] The same reference numerals will be used throughout the drawings to refer to components that perform similar functions or operations. Throughout the specification, when it is mentioned that one component is connected to another component, not only can the one component be directly connected to the other component, but the one component can also be indirectly connected to the other component through another component. In addition, unless otherwise mentioned, the inclusion of a certain element does not mean the exclusion of other elements, but means that such elements may also be included.

[0037] Unless otherwise specifically limited, the description embodying elements by limitation or addition may be applied to all inventions and is not limited to a specific invention.

[0038] In the description and claims of the invention of this application, unless otherwise mentioned, the singular form is intended to include the plural form.

[0039] In the description and claims of the invention of this application, unless otherwise mentioned, "or" includes "and". Therefore, "including A or B" means three cases, namely, the case including A, the case including B, and the case including A and B.

[0040] The battery box according to the present invention may be a pouch-shaped battery box made of a laminate sheet including a resin layer and a metal layer. Specifically, the battery box may include: a first resin layer having a hot melt property for sealing a battery cell; a metal layer having a moisture barrier property; a second resin layer configured to protect an electrode assembly in the battery box from external influences; and a heat dissipation layer including a carbon material and a binder, wherein the heat dissipation layer may be added to the surface of the second resin layer, and the thickness of the heat dissipation layer may be 40nm to 800nm.

[0041] Specifically, the first resin layer may be made of a polymer resin that is heat-fusible, has low electrolyte absorption, and is neither swollen nor corroded by the electrolyte, such as a cast polypropylene film (CPP).

[0042] The metal layer may be made of aluminum (Al) or an aluminum alloy so as to exhibit a function of improving the strength of the battery case in addition to the function of preventing the inflow of foreign matter such as gas and moisture and preventing the outflow of the electrolyte.

[0043] Since the second resin layer needs to have excellent resistance to the external environment, the second resin layer must have tensile strength and weather resistance higher than a predetermined level. In this regard, the polymer resin of the second resin layer may include polyethylene naphthalate (PEN), polyethylene terephthalate (PET), or stretched nylon having excellent tensile strength and weather resistance.

[0044] The heat dissipation layer may include a carbon material and a binder configured to bond the carbon material, wherein the carbon material may be at least one selected from the following: graphite, carbon nanotubes (CNTs), single-walled carbon nanotubes (SWNTs), graphene and activated carbon fibers (ACFs), and more particularly may be graphene.

[0045] Graphene has a structure in which hexagons each composed of six carbons are connected to each other to form a single layer having a two-dimensional structure, unlike carbon nanotubes having a tubular one-dimensional structure and graphite having a three-dimensional structure in which a plurality of layers are stacked.

[0046] The electron mobility of graphene is 50,000 cm 2 / V second or more, which means that electrons move at the speed of light as if they had zero mass. Graphene is also characterized by structural and chemical stability and excellent thermal conductivity, and is composed only of carbon, which is a relatively light element, making it easy to form one-dimensional or two-dimensional nanopatterns. In particular, graphene sheets are inexpensive materials with excellent price competitiveness compared to conventional nanomaterials.

[0047] In the pouch-shaped battery case according to the present invention, the thickness of the first resin layer is 10 μm to 50 μm, the thickness of the metal layer is 20 μm to 150 μm, and the thickness of the second resin layer is 5 μm to 40 μm. If the thickness of each layer of the pouch-shaped battery case is too small, it is difficult to achieve the effect of blocking substances and improving strength, which is undesirable. On the contrary, if the thickness of each layer is too large, the workability is reduced and the thickness of the sheet increases, which is also undesirable.

[0048] The thickness of the heat dissipation layer may be 40 nm to 800 nm, in particular, 80 nm to 800 nm. If the thickness of the heat dissipation layer is less than 40 nm, the heat dissipation performance may be reduced and the safety may be reduced, which is not desirable, and if the thickness of the heat dissipation layer is greater than 800 nm, the effect of improving the heat dissipation performance is low and the cost is significantly increased, which is also not desirable.

[0049] The binder may be at least one selected from the following: an epoxy-based binder, an acrylic-based binder, a hydrocarbon-based binder, a polyester-based binder, a vinyl-based binder, and a urethane-based binder, or a copolymer thereof. For example, the binder may be polyvinylidene fluoride, polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-trichloroethylene, polymethyl methacrylate, polyacrylonitrile, polyvinyl acetate, ethylene-vinyl acetate copolymer (polyethylene-co-vinyl acetate), polyimide, or polyethylene oxide.

[0050] The acrylic-based binder may be at least one selected from the following: methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, isobutyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, and lauryl (meth)acrylate.

[0051] The binder may be contained at 0.01 to 5 wt %, specifically 0.1 to 1 wt %, based on the total weight of the solid content.

[0052] If the binder content is less than 0.01 wt % based on the total weight of the solid content, surface adhesion may be reduced, which is undesirable, and if the binder content is greater than 5 wt % based on the total weight of the solid content, heat dissipation characteristics may be reduced, which is also undesirable.

[0053] As methods for preparing graphene, mechanical exfoliation, epitaxy, thermal expansion, chemical functionalization, gas phase, and dispersion in an organic solvent are used, but at an industrial level, a method of directly growing graphene from a copper plate or a catalytic substrate by chemical vapor deposition, and a method of oxidizing and separating graphite to prepare graphene oxide and reducing it using a reducing agent or by heat treatment to prepare reduced graphene are widely used.

[0054] However, the chemical vapor deposition method has the disadvantage that it is difficult to apply to a large area, especially difficult to transfer to a glass surface with a large area, while the reduced graphene preparation method of preparing graphene oxide from graphite and reducing the graphene oxide has problems such as undergoing multiple processes and extremely low productivity and destroying the inherent properties of graphene.

[0055] The carbon material constituting the heat dissipation layer according to the present invention may include graphene prepared using a liquid phase exfoliation method.

[0056] Liquid phase exfoliation is a method designed to maintain the physical and electrical properties of graphene, which can prevent defects formed during the preparation of reduced graphene oxide (rGO) using a chemical exfoliation method and can form graphene without functional groups. Liquid phase exfoliation is a method that uses ionic substances and organic solvents to induce intercalation of graphite layers, disperses them, and separates single-layer graphene by layer separation of the dispersed solution using ultracentrifugation.

[0057] Since graphene prepared by liquid phase exfoliation has better dispersibility than graphene prepared by conventional CVD or oxidation / reduction methods, a uniform coating can be formed without using a separate dispersant. In addition, since the crystallinity of graphene is excellent due to the liquid phase exfoliation method, the adhesion through π-π stacking is excellent when coating the film.

[0058] The present invention provides a battery cell comprising the battery case, wherein the battery cell may be a pouch-shaped battery cell. Figure 1 2 are a perspective view and a partial vertical sectional view of a pouch-shaped battery cell according to the present invention.

[0059] Reference Figure 1 In the pouch-shaped battery cell 100, the electrode assembly 300 is accommodated in the pouch-shaped battery box 200, a sealing portion 202 is formed on the outer periphery of the cup portion 201 accommodating the electrode assembly 300, an electrode lead 310 connected to the electrode tab of the electrode assembly 300 extends outward from the sealing portion 202 of the pouch-shaped battery box 200, and a heat dissipation layer 240 is provided on the outer surface of the pouch-shaped battery box 200.

[0060] A first embodiment of a method for manufacturing a pouch-shaped battery cell may include the following steps: preparing a pouch-shaped battery case made of a laminate sheet including a first resin layer, a metal layer, and a second resin layer; preparing a solution for a heat dissipation layer including a carbon material and a binder; forming a heat dissipation layer on the pouch-shaped battery case; and accommodating an electrode assembly in the pouch-shaped battery case and sealing the pouch-shaped battery case.

[0061] The step of forming the heat dissipation layer may be performed by a method of forming the heat dissipation layer on the outer surface of the second resin layer using a gravure coating method.

[0062] In the gravure coating method, 0.01 wt % to 1 wt % of an acrylic-based binder is added to graphene ink prepared using a liquid phase exfoliation method to prepare a solution for a heat dissipation layer.

[0063] Before molding the cup portion in the pouch-shaped battery case, the outer surface of the second resin layer was coated with a solution for a heat dissipation layer using a gravure coating method to form a heat dissipation layer.

[0064] The pouch-shaped battery cell is manufactured by molding a cup portion in a pouch-shaped battery case in which a heat dissipation layer is thus formed, accommodating an electrode assembly in the cup portion, and sealing the pouch-shaped battery cell by heat fusion.

[0065] When the gravure coating method is used, the heat dissipation layer may have a uniform thickness, but since the pouch-shaped battery cell is manufactured using the coated pouch-shaped battery case, the heat dissipation layer may not be formed on the electrode lead or the lead film.

[0066] A second embodiment of the method for manufacturing a pouch-shaped battery cell may include the following steps: preparing a pouch-shaped battery box made of a laminate sheet including a first resin layer, a metal layer, and a second resin layer; housing an electrode assembly in the pouch-shaped battery box and sealing the pouch-shaped battery box; preparing a solution for a heat dissipation layer including a carbon material and a binder; and forming a heat dissipation layer on the pouch-shaped battery box.

[0067] The method of manufacturing the pouch-shaped battery cell according to the second embodiment is different from the method of manufacturing the pouch-shaped battery cell according to the first embodiment in that the step of forming the heat dissipation layer is performed after assembling the pouch-shaped battery cell.

[0068] Specifically, the solution for the heat dissipation layer is prepared by adding 0.01 wt % to 1 wt % of an acrylic-based binder to graphene ink prepared using a liquid phase exfoliation method.

[0069] A dip coating method may be used in which the remaining portion of the assembled pouch-shaped battery cell except for the electrode lead may be dipped into a solution for a heat dissipation layer for coating.

[0070] Although the dip coating method has low process cost and can form a heat dissipation layer on all parts of the pouch-shaped battery cell except the electrode leads, the dip coating method has disadvantages of uneven thickness of the heat dissipation layer and a large amount of solution used for the heat dissipation layer.

[0071] The present invention will be described hereinafter with reference to examples, which are provided only for easier understanding of the present invention and should not be construed as limiting the scope of the present invention.

[0072] <Example 1>

[0073] A solution for a heat dissipation layer was prepared by adding 1 g of graphene ink prepared using a liquid phase exfoliation method and 0.1 g of an acrylic acid-based binder as a binder to 100 ml of ethanol as a solvent.

[0074] The outer surface of the second resin layer of the pouch-shaped battery case was coated with a solution for a heat dissipation layer using a gravure coating method to form a heat dissipation layer having a thickness of 40 nm.

[0075] A cup portion was molded in the thus prepared pouch-shaped battery case, the electrode assembly was housed in the cup portion, and the periphery of the cup portion was heated and pressurized to be sealed by heat fusion, thereby manufacturing 10 pouch-shaped battery cells.

[0076] <Example 2>

[0077] Ten pouch-shaped battery cells were manufactured using the same method as in Example 1, except that the heat dissipation layer was formed to have a thickness of 80 nm.

[0078] <Example 3>

[0079] Ten pouch-shaped battery cells were manufactured using the same method as in Example 1, except that the heat dissipation layer was formed to have a thickness of 200 nm.

[0080] <Example 4>

[0081] Ten pouch-shaped battery cells were manufactured using the same method as in Example 1, except that the heat dissipation layer was formed to have a thickness of 400 nm.

[0082] <Example 5>

[0083] Ten pouch-shaped battery cells were manufactured using the same method as in Example 1, except that the heat dissipation layer was formed to have a thickness of 800 nm.

[0084] <Comparative Example>

[0085] Ten pouch-shaped battery cells were manufactured using the same method as in Example 1 using the pouch-shaped battery case on which the heat dissipation layer was not formed.

[0086] <Hot box test>

[0087] In order to examine the heat dissipation performance of the pouch-shaped battery cells manufactured in Examples 1 to 5 and the comparative example, the fully charged pouch-shaped battery cells were placed in a chamber, the temperature of the chamber was increased from room temperature at 5°C / min, and when the temperature reached 140°C, the damage to the pouch-shaped battery cells was examined while maintaining the temperature for 1 hour.

[0088] The results based on thickness and cost of the heat sink layer are shown in Table 1 below.

[0089] <Adhesion Test>

[0090] In the pouch-shaped battery case with the heat dissipation layer prepared in each of Examples 1 to 5, on the surface of the pouch-shaped battery case on which the heat dissipation layer was formed, scratches were made with cross lines using a crosshatch cutter to form a 10 mm×10 mm area, and then an adhesive tape was attached to the surface of the pouch-shaped battery case. After rubbing the adhesive tape with uniform force, the adhesive tape was peeled off, and the number of sheets of the heat dissipation layer separated from the surface of the pouch-shaped battery case was counted.

[0091] The adhesiveness of the heat dissipation layer is expressed as a numerical value from 0B to 5B using the number of sheets.

[0092] Specifically, the adhesion test may be performed according to the standard KS M ISO 2409 and the standard ASTM D3359.

[0093] In the following Table 1, since a pouch-shaped battery case on which no heat dissipation layer was formed was used in the comparative example, the adhesiveness of the heat dissipation layer was not measured.

[0094] [Table 1]

[0095] Heat dissipation layer(nm) Hot box test pass rate (%) <![CDATA[Price (KRW / m 2 )]]> Adhesion test Example 1 40 70 150 5B Example 2 80 100 300 5B Example 3 200 100 700 5B Example 4 400 100 1,400 5B Example 5 800 100 2,800 5B Comparative Example - 30 - -

[0096] The results of the adhesion test are as follows. 5B: the cut surface was clean and the grid squares were not separated, 4B: small pieces of coating separated at the intersections (less than 5% of the grid area), 3B: small pieces of coating separated along the edges of the cut portions and at the intersections (5% to 15% of the grid area), 2B: the edges of the cut surface of the coating and some square separation (15% to 35% of the grid area), 1B: the coating peeled severely along the edges of the cut surface and the squares separated (35% to 65% of the grid area), and 0B: more peeling and separation than 1B (greater than 65% of the grid area).

[0097] Referring to Table 1 above, it is shown that 30% of the pouch-shaped battery cells of Example 1 with a heat dissipation layer thickness of 40nm failed the hot box test, while 70% of the pouch-shaped battery cells of the comparative example failed the test. However, it is shown that 100% of the pouch-shaped battery cells of Examples 2 to 5 with a heat dissipation layer thickness of 80nm to 800nm ​​passed the hot box test.

[0098] In the present invention, as described above, since graphene prepared using a liquid phase exfoliation method is used as a heat dissipation layer, a separate dispersant is not required, and even if the heat dissipation layer is formed with a thickness ranging from tens to hundreds of nanometers, heat dissipation performance is significantly improved.

[0099] Those skilled in the art to which the present invention pertains will recognize that various applications and modifications may be made within the scope of the present invention based on the above description.

[0100] (Explanation of Reference Numerals)

[0101] 100: Pouch cell

[0102] 200: Pouch battery box

[0103] 201: Cup Department

[0104] 202: Sealing part

[0105] 210: First resin layer

[0106] 220: Metal layer

[0107] 230: Second resin layer

[0108] 240: Heat dissipation layer

[0109] 300: Electrode assembly

[0110] 310: Electrode lead

Claims

1. A battery box, comprising: A first resin layer having a hot-melt property; a metal layer having moisture barrier properties; a second resin layer configured to protect the internal components from external influences; as well as A heat dissipation layer comprising a carbon material and a binder, wherein The heat dissipation layer is added to the surface of the second resin layer, and The thickness of the heat dissipation layer is 40nm to 800nm.

2. The battery case according to claim 1, wherein the carbon material is at least one selected from the group consisting of graphite, carbon nanotubes (CNTs), single-walled carbon nanotubes (SWNTs), graphene, and activated carbon fibers (ACFs).

3. The battery case according to claim 2, wherein the carbon material is graphene prepared using a liquid phase exfoliation method. The battery case according to claim 1 , wherein the heat dissipation layer has a thickness of 80 nm to 800 nm.

5. The battery case according to claim 1, wherein the binder is contained in an amount of 0.01 wt % to 5 wt % based on the total weight of the solid contents.

6. A battery case according to claim 1, wherein the adhesive is at least one selected from the following: an epoxy-based adhesive, an acrylic-based adhesive, a hydrocarbon-based adhesive, a polyester-based adhesive, a vinyl-based adhesive, a urethane-based adhesive, and an acrylate-based adhesive, or a copolymer containing the same.

7. A battery unit comprising a battery case according to any one of claims 1 to 6, wherein The battery box contains an electrode assembly. A sealing portion is formed on an outer circumference of a cup portion configured to allow the electrode assembly to be accommodated therein, An electrode lead connected to the electrode tab of the electrode assembly extends outward from the sealing portion of the battery case, and A heat dissipation layer is arranged on the outer surface of the battery box.

8. A method for manufacturing the battery cell according to claim 7, the method comprising: preparing a battery case made of a laminate sheet including a first resin layer, a metal layer, and a second resin layer; preparing a solution for a heat dissipation layer comprising a carbon material and a binder; forming a heat dissipation layer on the battery box; as well as The electrode assembly is housed in the battery case and the battery case is sealed. 9 . The method according to claim 8 , wherein the step of forming the heat dissipation layer is performed using a gravure coating method.

10. A method of manufacturing the battery cell according to claim 7, the method comprising: preparing a battery case made of a laminate sheet including a first resin layer, a metal layer, and a second resin layer; Accommodating an electrode assembly in the battery case and sealing the battery case; preparing a solution for a heat dissipation layer comprising a carbon material and a binder; as well as A heat dissipation layer is formed on the battery box.

11. The method according to claim 10, wherein the step of forming the heat dissipation layer is performed using a dip coating method.

Images