Battery case, battery cell including same, and method for manufacturing same battery cell

Abstract

The present invention relates to a battery case, a battery cell including same, and a method for manufacturing the battery cell, the battery case comprising: a first resin layer with thermal fusion properties; a metal layer with moisture barrier properties; a second resin layer for protecting internal components from the outside; and a heat dissipation layer including a carbon material and a binder, wherein the heat dissipation layer is added to the surface of the second resin layer and has a thickness of 40 nm to 800 nm, whereby the battery case exhibits improved heat dissipation performance while minimizing an increase in thickness.

Description

Battery case, battery cell including the same, and method for manufacturing the battery cell

[0001] This application claims the benefit of priority to Korean Patent Application No. 2023-0132102, filed October 4, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a pouch-type battery case including a carbon coating layer, a pouch-type battery cell including the same, and a method for manufacturing the pouch-type battery cell. Specifically, the present invention relates to a pouch-type battery case including a carbon coating layer capable of preventing further ignition and explosion by blocking the transfer of heat generated during the charging and discharging process.

[0003]

[0004] Lithium secondary batteries, which are rechargeable and have high energy density, are attracting attention as a new energy source that not only can drastically reduce the use of fossil fuels, but is also environmentally friendly because they do not produce byproducts from energy use.

[0005] Lithium secondary batteries can be classified according to their shape, and more specifically, they can be classified into cylindrical battery cells and square battery cells manufactured by inserting an electrode assembly into a can made of metal, and pouch-type battery cells manufactured by inserting an electrode assembly into a battery case formed by molding a laminate sheet including a resin layer and a metal layer.

[0006] Among these, the pouch-type battery cell has the advantages of being easy to change shape and having high energy density.

[0007] However, the resin layer constituting the laminate sheet is composed of materials that have poor heat dissipation performance, such as nylon or polyethylene terephthalate, making it vulnerable to the heat generation phenomenon that occurs during charging and discharging of secondary batteries. Furthermore, as the temperature increases, the discharge amount increases, causing a rapid decrease in the usable life of the battery.

[0008] When the temperature of a battery cell exceeds a reference temperature due to the overheating phenomenon of a secondary battery, the electrode assembly or electrolyte decomposes, generating a large amount of gas. This gas generated within the battery cell increases the internal pressure of the battery cell, causing the cell itself to swell. This swelling can cause dimensional changes in the multiple pouch-type battery cells arranged within the battery pack, and can also cause problems such as deformation of the pack case.

[0009] Accordingly, various methods are being attempted to reduce the heat generation phenomenon of pouch-type battery cells.

[0010] Patent Document 1 relates to a packaging material for a pouch-type battery, comprising an outermost layer of a heat-resistant resin, a barrier layer containing aluminum or an aluminum alloy, and an innermost layer of a thermoplastic resin, wherein the packaging material comprises a heat-dissipating layer containing a carbon material added to at least one of the constituent layers or a separate additional heat-dissipating layer containing a carbon material and a binder resin. By having such a configuration, when the internal temperature of the battery rapidly rises due to overcharging or an internal short circuit caused by an abnormal reaction within the lithium secondary battery or when the battery is exposed to a high-temperature environment, the carbon material disperses the heat of the packaging material, thereby delaying and suppressing the rise in the internal temperature of the battery.

[0011] Patent Document 1 discloses adding a heat dissipation layer having a thickness of 1 micrometer or more to a packaging material and measuring the cooling degree of the packaging material over time.

[0012] Patent Document 1 shows that the thicker the heat dissipation layer, the better the heat dissipation performance. However, there is a problem in that the overall thickness of the packaging material increases when a thick heat dissipation layer is used for heat dissipation performance.

[0013] Therefore, there is a need to develop a pouch-type battery case with improved heat dissipation characteristics while minimizing the increase in thickness of the pouch-type battery case.

[0014] (Prior art literature)

[0015] (Patent Document 1) Korean Patent Publication No. 2013-0011977 (January 30, 2013)

[0016]

[0017] The present invention is intended to solve the above-mentioned problems, and aims to provide a pouch-type battery case that minimizes an increase in the thickness of the pouch-type battery case and significantly increases heat dissipation performance, a pouch-type battery cell including the pouch-type battery case, and a method for manufacturing the pouch-type battery cell.

[0018]

[0019] To achieve this purpose, a battery case according to the present invention comprises a first resin layer having heat-melting properties, a metal layer having moisture barrier properties, a second resin layer for protecting internal components from the outside, and a heat dissipation layer including 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 may be 40 nm to 800 nm.

[0020] In the above 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).

[0021] In the above battery case, the carbon material may be graphene manufactured by a liquid exfoliation method.

[0022] In the above battery case, the thickness of the heat dissipation layer may be 80 nm to 800 nm.

[0023] In the above battery case, the binder may be included in a range of 0.01 wt% to 5 wt% based on the total weight of the solid content.

[0024] In the above battery case, the binder may be one or more selected from the group consisting of epoxy, acrylic, hydrocarbon, polyester, vinyl, urethane, and acrylate, or a copolymer including these.

[0025] In a battery cell including the above battery case, an electrode assembly is accommodated inside the battery case, a sealing portion is formed on the outer periphery of a cup portion in which the electrode assembly is accommodated, electrode leads connected to electrode tabs of the electrode assembly extend outward from the sealing portion of the battery case, and a heat dissipation layer is provided on the outer surface of the battery case.

[0026] The present invention provides a method for manufacturing the battery cell, and as one embodiment, the method may include a step of preparing a battery case composed of a laminate sheet including a first resin layer, a metal layer, and a second resin layer, a step of preparing a solution for a heat dissipation layer including a carbon material and a binder, a step of forming a heat dissipation layer in the battery case, and a step of accommodating an electrode assembly in the battery case and then sealing it.

[0027] The step of forming the above heat dissipation layer may use a gravure coating method.

[0028] In addition, the present invention provides a method for manufacturing the battery cell, which may include, as another embodiment, a step of preparing a battery case composed of a laminate sheet including a first resin layer, a metal layer, and a second resin layer, a step of accommodating an electrode assembly in the battery case and then sealing it, a step of preparing a solution for a heat dissipation layer including a carbon material and a binder, and a step of forming a heat dissipation layer in the battery case.

[0029] In the above method for manufacturing a battery cell, the step of forming the heat dissipation layer may use a dip coating method.

[0030]

[0031] The present invention can also be provided in a form in which various means for solving the above problem are combined.

[0032]

[0033] As described above, the battery case according to the present invention exhibits high heat dissipation performance even though the thickness of the heat dissipation layer is applied at the level of tens to hundreds of nanometers.

[0034] Additionally, by reducing the thickness of the heat dissipation layer, manufacturing costs can be reduced, and by efficiently managing heat, the risk of shortened product life, failure, and fire can be reduced.

[0035] Additionally, it can have the effect of improving energy density by minimizing the increase in thickness of the battery case.

[0036]

[0037] Figure 1 is a perspective view and a vertical cross-sectional view of a portion of a pouch-type battery cell according to the present invention.

[0038]

[0039] Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail, so that those with ordinary skill in the art can easily implement the present invention. When describing the operating principles of the embodiments of the present invention in detail, detailed descriptions of related known functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present invention.

[0040] Parts with similar functions and actions are designated by the same drawing reference numerals throughout the drawings. Throughout the specification, when a part is said to be connected to another part, this includes not only direct connections but also indirect connections with other elements intervening. Furthermore, inclusion of a component does not exclude other components unless otherwise specifically stated, but rather implies the inclusion of additional components.

[0041] Descriptions that specify or add elements can be applied to all inventions unless otherwise specified, and are not limited to descriptions of specific inventions.

[0042] Throughout the description and claims of the invention herein, the singular includes the plural unless otherwise stated.

[0043] Throughout the description and claims of the present invention, the term "or" includes "and" unless otherwise stated. Therefore, "comprising A or B" means all three cases of including A, including B, or including A and B.

[0044] The battery case according to the present invention may be a pouch-type battery case composed of a laminate sheet including a resin layer and a metal layer. Specifically, the battery case includes a first resin layer having heat-sealability for sealing a battery cell, a metal layer having moisture barrier properties, a second resin layer for protecting an electrode assembly inside from the outside, and a heat dissipation layer including a carbon material and a binder, wherein the heat dissipation layer is added to a surface of the second resin layer, and the thickness of the heat dissipation layer may be 40 nm to 800 nm.

[0045] Specifically, the first resin layer may be formed of a polymer resin that has heat-sealability, low hygroscopicity with respect to the electrolyte, and does not expand or erode due to the electrolyte, and may be formed of, for example, a non-stretched polypropylene film (CPP).

[0046] In addition to the function of preventing the inflow of foreign substances such as gas and moisture and the outflow of electrolyte, the metal layer may be made of aluminum (Al) or an aluminum alloy so that it can have the function of improving the strength of the battery case.

[0047] Since the second resin layer must have excellent resistance to external environments, it requires a certain level of tensile strength and weather resistance. In this regard, the polymer resin of the second resin layer may include polyethylene naphthalate (PEN), polyethylene terephthalate (PET), or stretched nylon, which have excellent tensile strength and weather resistance.

[0048] The above heat dissipation layer includes a carbon material and a binder for bonding thereof, and 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 (Activated Carbon Fiber-ACF), and more specifically, may be graphene.

[0049] The above graphene is a structure in which hexagons of six carbon atoms are connected to each other to form a two-dimensional single layer. It has a structure that is different from carbon nanotubes, which are formed into a one-dimensional tubular structure, or graphite, which is formed into a three-dimensional structure by stacking multiple layers.

[0050] Graphene boasts an electron mobility of over 50,000 ㎠ / Vs, allowing electrons to move at the speed of light, as if they had zero mass. Furthermore, it boasts structural and chemical stability, as well as excellent thermal conductivity. Furthermore, its composition of carbon, a relatively light element, makes it easy to fabricate one- or two-dimensional nanopatterns. Furthermore, graphene sheets are inexpensive and offer excellent price competitiveness compared to existing nanomaterials.

[0051] 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 thin, it is difficult to expect a barrier function for materials and an improvement in strength, and conversely, if it is too thick, the processability is reduced and an increase in the thickness of the sheet is caused, which is not preferable.

[0052] The thickness of the heat dissipation layer is 40 nm to 800 nm, and more specifically, 80 nm to 800 nm. If the thickness of the heat dissipation layer is thinner than 40 nm, the heat dissipation performance may be reduced, which may cause safety issues. If the thickness of the heat dissipation layer is thicker than 800 nm, the heat dissipation effect may be low and the cost may significantly increase, which is not desirable.

[0053] The above binder may be one or more selected from the group consisting of epoxy, acrylic, hydrocarbon, polyester, vinyl, and urethane, or a copolymer including these, for example, polyvinylidene fluoride, polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-trichloroethylene, polymethylmethacrylate, polyacrylonitrile, polyvinylacetate, polyethylene-covinylacetate, polyimide, polyethylene oxide, etc.

[0054] The above acrylic binder may be at least one selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, iso-butyl (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.

[0055] The above binder may be included in a range of 0.01 wt% to 5 wt% based on the total weight of the solid content, and specifically, may be included in a range of 0.1 wt% to 1 wt%.

[0056] If the content of the above binder is less than 0.01 wt% based on the total weight of the solid content, surface adhesion may be reduced, and if it is more than 5 wt%, heat dissipation properties may be reduced, which is not desirable.

[0057] There are various methods for producing graphene, including mechanical exfoliation, epitaxy, thermal expansion, chemical functionalization, and gas phase and organic solvent dispersion. However, from an industrial perspective, the most widely used methods include growing graphene directly from a copper plate or catalyst substrate by chemical vapor deposition, and producing reduced graphene by oxidizing graphite to separate the graphene and then reducing it using a reducing agent or heat treatment.

[0058] However, the chemical vapor deposition method has the disadvantage of being difficult to apply to large areas and, in particular, difficult to transfer to large areas on glass surfaces. In addition, the reduced graphene method, which manufactures and reduces graphene oxide from graphite, has problems such as very low productivity due to the multiple processes and damage to the unique properties of graphene.

[0059] The carbon material constituting the heat dissipation layer according to the present invention may include graphene manufactured by a liquid exfoliation method.

[0060] The above liquid exfoliation method is a method designed to maintain the physical and electrical properties of graphene, and can prevent defects formed during the production of reduced graphene oxide (rGO) through a chemical exfoliation method, and is a method for forming graphene without functional groups. It is a method of inducing intercalation of graphite layers using an ionic substance and an organic solvent, dispersing it, and then separating the layers of the dispersed solution using an ultracentrifugation method to separate single-layer graphene.

[0061] Graphene produced using the above liquid exfoliation method exhibits superior dispersibility compared to graphene produced using conventional CVD or oxidation / reduction methods, enabling the formation of a uniform coating layer without the use of a separate dispersant. Furthermore, the liquid exfoliation method results in superior crystallinity, resulting in superior adhesion due to π-π stacking when coated as a film.

[0062] The present invention provides a battery cell including the battery case, and the battery cell may be a pouch-type battery cell. FIG. 1 illustrates a perspective view and a vertical cross-sectional view of a portion of a pouch-type battery cell according to the present invention.

[0063] Referring to FIG. 1, a pouch-type battery cell (100) has an electrode assembly (300) housed inside the pouch-type battery case (200), a sealing portion (202) is formed on the outer periphery of a cup portion (201) in which the electrode assembly (300) is housed, electrode leads (310) connected to electrode tabs of the electrode assembly (300) extend outward from the sealing portion (202) of the pouch-type battery case (200), and a heat dissipation layer (240) is present on the outer surface of the pouch-type battery case (200).

[0064] As a method for manufacturing a pouch-type battery cell, a first embodiment may include a step of preparing a pouch-type battery case composed of a laminate sheet including a first resin layer, a metal layer, and a second resin layer, a step of preparing a solution for a heat dissipation layer including a carbon material and a binder, a step of forming a heat dissipation layer in the pouch-type battery case, and a step of accommodating an electrode assembly in the pouch-type battery case and then sealing it.

[0065] The step of forming the heat dissipation layer may be configured by a method of coating the heat dissipation layer on the outer surface of the second resin layer using a gravure coating method.

[0066] As the above gravure coating method, a solution for a heat dissipation layer is prepared by adding 0.01 wt% to 1 wt% of an acrylic binder to graphene ink manufactured by a liquid exfoliation method.

[0067] In a step prior to forming the cup portion in the pouch-type battery case, the heat dissipation layer is formed by coating the solution for the heat dissipation layer on the outer surface of the second resin layer using a gravure coating method.

[0068] In this way, a cup part is formed in a pouch-shaped battery case in which a heat dissipation layer is formed, an electrode assembly is placed therein, and then heat-sealed to manufacture a pouch-shaped battery cell.

[0069] The above gravure coating method can form a heat dissipation layer with a uniform thickness, but since a pouch-type battery cell is manufactured using a coated pouch-type battery case, the heat dissipation layer is not formed on the electrode lead or lead film.

[0070] As a method for manufacturing a pouch-type battery cell, a second embodiment may include a step of preparing a pouch-type battery case composed of a laminate sheet including a first resin layer, a metal layer, and a second resin layer, a step of accommodating an electrode assembly in the pouch-type battery case and then sealing it, a step of preparing a solution for a heat-dissipating layer including a carbon material and a binder, and a step of forming a heat-dissipating layer in the pouch-type battery case.

[0071] In the method for manufacturing a pouch-shaped battery cell according to the second embodiment, the step of forming a heat dissipation layer is different from the method for manufacturing a pouch-shaped battery cell according to the first embodiment in that it is performed after assembling the pouch-shaped battery cell.

[0072] Specifically, a solution for a heat dissipation layer is prepared by adding 0.01 wt% to 1 wt% of an acrylic binder to graphene ink manufactured by a liquid exfoliation method.

[0073] A dip coating method can be used to coat the remaining parts of the assembled pouch-type battery cell, excluding the electrode leads, by dipping them in the solution for the heat-dissipating layer.

[0074] The above-mentioned dip coating method has a low process cost and can form a heat dissipation layer on all parts except the electrode leads, but has the disadvantages that the thickness of the heat dissipation layer is not uniform and a large amount of solution for the heat dissipation layer is used.

[0075]

[0076] Hereinafter, the present invention will be described with reference to embodiments, but this is for easier understanding of the present invention, and the scope of the present invention is not limited thereto.

[0077]

[0078] <Example 1>

[0079] A solution for a heat-radiating layer was prepared by adding 1 g of graphene ink manufactured by a liquid exfoliation method and 0.1 g of an acrylic binder as a binder to 100 ml of ethanol as a solvent.

[0080] The solution for the above heat dissipation layer was coated on the outer surface of the second resin layer of the pouch-type battery case using the gravure coating method to a thickness of 40 nm to form a heat dissipation layer.

[0081] A cup portion was formed in the pouch-type battery case manufactured in this manner, an electrode assembly was placed therein, and then the outer periphery of the cup portion was subjected to heat and pressure heat sealing to manufacture 10 pouch-type battery cells.

[0082]

[0083] <Example 2>

[0084] Ten pouch-type battery cells were manufactured in the same manner as in Example 1, except that the heat dissipation layer was formed to have a thickness of 80 nm.

[0085]

[0086] <Example 3>

[0087] Ten pouch-type battery cells were manufactured in the same manner as in Example 1, except that the heat dissipation layer was formed to have a thickness of 200 nm.

[0088]

[0089] <Example 4>

[0090] Ten pouch-type battery cells were manufactured in the same manner as in Example 1, except that the heat dissipation layer was formed to have a thickness of 400 nm.

[0091]

[0092] <Example 5>

[0093] Ten pouch-type battery cells were manufactured in the same manner as in Example 1, except that the heat dissipation layer was formed to have a thickness of 800 nm.

[0094]

[0095] <Comparative Example>

[0096] Ten pouch-type battery cells were manufactured using the same method as Example 1 using a pouch-type battery case without a heat dissipation layer formed thereon.

[0097]

[0098] <Hot box 테스트>

[0099] In order to confirm the heat dissipation performance of the pouch-type battery cells manufactured in Examples 1 to 5 and Comparative Examples, fully charged pouch-type battery cells were placed in a chamber, the temperature of the chamber was increased from room temperature to 5°C / min, and when it reached 140°C, the temperature was maintained for 1 hour to check for damage to the pouch-type battery cells.

[0100] The results and cost of the heat dissipation layer according to thickness are shown in Table 1 below.

[0101]

[0102] Adhesion Test

[0103] In the pouch-shaped battery case having the heat-dissipating layer formed as manufactured in Examples 1 to 5 above, a cross hatch cutter was used to create a scratch with a cross line measuring 10 mm x 10 mm on the surface on which the heat-dissipating layer was formed, and then tape was attached. After rubbing the tape with uniform force, the tape was removed and the number of pieces of the heat-dissipating layer that fell off was counted.

[0104] Using the number of pieces like this, the size of the adhesive strength of the heat dissipation layer was expressed as a numerical value from 0B to 5B.

[0105] Specifically, the adhesion test can be conducted according to the standards of KS M ISO 2409 and ASTM D3359.

[0106] In the comparative example in Table 1 below, the adhesive strength of the heat dissipation layer could not be measured because a pouch-type battery case without a heat dissipation layer was used.

[0107]

[0108] Heat dissipation layer (nm) Hot box test pass rate (%) Price (won / ㎡) Adhesion test Example 140701505B Example 2801003005B Example 32001007005B Example 44001001,4005B Example 58001002,8005B Comparative example -30--

[0109] *** Results of the above adhesion test: 5B: The cut surface is clean and the squares of the grid do not separate, 4B: Small pieces of the coating separate at the intersections (less than 5% of the grid area), 3B: Small pieces of the coating separate along the edges and at the intersections of the cut sections (5-15% of the grid area), 2B: The edges of the cut surface of the coating and some of the squares separate (15-35% of the grid area), 1B: The coating peeled significantly along the edges of the cut surface and the squares separated (35-65% of the grid area), 0B: More peeling and separation than 1B (more than 65% of the grid area)

[0110] Referring to Table 1 above, 30% of the pouch-type battery cells of Example 1 having a heat dissipation layer thickness of 40 nm failed the hot box test, and 70% of the pouch-type battery cells of the comparative example failed the test. However, the pouch-type battery cells of Examples 2 to 5 having a heat dissipation layer thickness of 80 nm to 800 nm showed results of passing the hot box test at 100%.

[0111] In this way, since the present invention uses graphene manufactured by a liquid exfoliation method as a heat dissipation layer, it does not require a separate dispersant, and even if the thickness of the heat dissipation layer is formed in the range of tens to hundreds of nanometers, it shows the effect of significantly improving heat dissipation performance.

[0112]

[0113] Anyone with ordinary knowledge in the field 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 contents.

[0114] (Explanation of symbols)

[0115] 100: Pouch-type battery cell

[0116] 200: Pouch-type battery case

[0117] 201: Cup Department

[0118] 202: Sealing section

[0119] 210: First resin layer

[0120] 220: Metal layer

[0121] 230: Second resin layer

[0122] 240: Heat dissipation layer

[0123] 300: Electrode assembly

[0124] 310: Electrode lead

Claims

1. First resin layer with heat-melting properties; Moisture-barrier metal layer; A second resin layer to protect the internal components from the outside; and A heat dissipation layer comprising carbon material and a binder; Including, The above heat dissipation layer is added to the surface of the second resin layer, A battery case wherein the thickness of the heat dissipation layer is 40 nm to 800 nm.

2. In paragraph 1, A battery case wherein the carbon material is at least one selected from the group consisting of graphite, carbon nanotube (CNT), single-walled carbon nanotube (SWNT), graphene, and activated carbon fiber (ACF).

3. In paragraph 2, A battery case wherein the above carbon material is graphene manufactured by a liquid exfoliation method.

4. In paragraph 1, A battery case wherein the thickness of the heat dissipation layer is 80 nm to 800 nm.

5. In paragraph 1, A battery case in which the above binder is included in a range of 0.01 wt% to 5 wt% based on the total weight of the solid content.

6. In paragraph 1, The above binder is a battery case which is at least one selected from the group consisting of epoxy, acrylic, hydrocarbon, polyester, vinyl, urethane, and acrylate, or a copolymer containing these.

7. In a battery cell including a battery case according to any one of clauses 1 to 6, The electrode assembly is stored inside the above battery case, A sealing portion is formed on the outer periphery of the cup portion in which the above electrode assembly is stored. The electrode leads connected to the electrode tabs of the above electrode assembly extend outward from the sealing portion of the above battery case, A battery cell having a heat dissipation layer on the outer surface of the battery case.

8. In the method for manufacturing a battery cell according to Article 7, A step of preparing a battery case composed of a laminate sheet including a first resin layer, a metal layer, and a second resin layer; A step of preparing a solution for a heat dissipation layer comprising a carbon material and a binder; A step of forming a heat dissipation layer on the above battery case; and A step of accommodating the electrode assembly in the above battery case and then sealing it; A method for manufacturing a battery cell including:

9. In paragraph 8, The step of forming the above heat dissipation layer is a method for manufacturing a battery cell using a gravure coating method.

10. In the method for manufacturing a battery cell according to Article 7, A step of preparing a battery case composed of a laminate sheet including a first resin layer, a metal layer, and a second resin layer; A step of accommodating the electrode assembly in the above battery case and then sealing it; A step of preparing a solution for a heat dissipation layer including a carbon material and a binder; and A step of forming a heat dissipation layer on the above battery case; A method for manufacturing a battery cell including:

11. In paragraph 10, The step of forming the above heat dissipation layer is a method for manufacturing a battery cell using a dip coating method.

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