Battery module, manufacturing method thereof, and battery pack including the same

Abstract

To provide a battery module having excellent thermal insulation, fire resistance, and flame retardancy or non-flammability to inhibit propagation of heat in a cell to cells adjacent thereto due to thermal runaway of a battery, a method of manufacturing the same, and a battery pack including the same.SOLUTION: The present invention relates to a battery module. The battery module includes a plurality of cells and an insulation member provided between the plurality of cells, the insulation member having an upper surface and a lower surface disposed so as to face cells adjacent thereto, respectively. The insulation member includes a first insulation sheet, a second insulation sheet, and an expansion layer formed between the first insulation sheet and the second insulation sheet. The present invention further relates to a method of manufacturing the battery module, and a battery pack including the battery module.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a battery module, a manufacturing method thereof, and a battery pack including the same. [Background technology]

[0002] Secondary batteries are power storage systems that offer excellent energy density by converting electrical energy into chemical energy and storing it. Unlike primary batteries, which cannot be recharged, secondary batteries are rechargeable and are widely used in IT devices such as smartphones, cellular phones, laptops, and tablet PCs. In recent years, interest in electric vehicles has grown to prevent environmental pollution, and high-capacity secondary batteries are being adopted for electric vehicles. Such secondary batteries are required to have characteristics such as high density, high output, and stability.

[0003] On the other hand, when a battery contains a large number of high-capacity cells such as lithium secondary batteries, one cell may overheat for some reason and experience thermal runaway, adversely affecting other adjacent cells, so it is required that adjacent cells are thermally insulated from each other.

[0004] Therefore, conventionally, plates or insulating resin plates are placed between the cells to insulate and heat the adjacent cells.

[0005] The above-mentioned information disclosed in the background of the invention is merely intended to enhance understanding of the background of the invention, and therefore may include information that does not constitute prior art. Summary of the Invention [Problem to be solved by the invention]

[0006] One embodiment provides a battery module having excellent heat insulation properties as well as fire resistance and flame retardancy or non-combustibility in order to suppress heat propagation between adjacent cells due to thermal runaway of the battery, a manufacturing method thereof, and a battery pack including the same. [Means for solving the problem]

[0007] One embodiment provides a battery module including a plurality of cells and insulating members respectively provided between the plurality of cells and arranged such that their upper and lower surfaces face adjacent cells, wherein the insulating members include a first insulating sheet, a second insulating sheet, and an expansion layer formed between the first insulating sheet and the second insulating sheet.

[0008] The cells may be secondary battery cells.

[0009] The first and second insulation sheets may each include a substrate and an aerogel layer formed on the substrate.

[0010] The substrates of the first and second insulation sheets may be disposed so as to face the adjacent cells, and the aerogel layers may be disposed so as to face the expanded layers.

[0011] The base material of each of the first and second heat insulating sheets may be formed of one or more materials selected from the group consisting of resins, metals, and inorganic materials other than metals.

[0012] The aerogel layers of the first and second insulation sheets may each comprise an aerogel, a fibrous support, and a functional material including a binder, a dispersant, or a combination thereof.

[0013] The aerogel has a BET specific surface area of ​​500 m 2 / g~1,000m 2 / g.

[0014] The fibrous support may be one or more fibers selected from the group consisting of natural fibers, silica fibers, glass fibers, carbon fibers, graphite fibers, mineral fibers, and polymer fibers.

[0015] The binder may include a water-based polymeric binder.

[0016] The dispersant may be one or more selected from the group consisting of surfactants, silane coupling agents, and phosphate salts.

[0017] The aerogel layer may contain 10% by weight to 90% by weight of the aerogel, 5% by weight to 70% by weight of the fibrous support, and 0.5% by weight to 20% by weight of the functional material, based on the total amount of the aerogel layer.

[0018] The expandable layer may be one or more selected from the group consisting of foaming materials that expand when the ambient temperature increases to 100 to 200°C, and flame-retardant materials with a melting temperature of 60 to 100°C.

[0019] The foaming substance may be at least one selected from the group consisting of expanded graphite, organic foaming agents, and inorganic foaming agents, the organic foaming agent may be at least one selected from the group consisting of azodicarbonamide, dinitropentamethylenetetramine, and oxybis(benzenesulfonylhydrazide), and the inorganic foaming agent may be at least one selected from the group consisting of hydrogencarbonates, carbonates, and organic acid salts.

[0020] The flame retardant material may be one or more selected from the group consisting of polyurethane, polyvinyl chloride, and polymers in which a flame retardant is dispersed.

[0021] The thickness of the expansion layer may be 1% to 30% of the total thickness of the heat insulating member.

[0022] When the expansion layer expands, the expansion layer flows out from the side of the heat insulating member to form an outflow portion, and the length of the outflow portion from the side of the heat insulating member may be 500% to 3000% of the thickness of the expansion layer.

[0023] The battery module may include an empty space other than the space where the cells and the insulating member are disposed, and may further include a coating layer formed to cover a side surface of the insulating member in the empty space formed below the battery module, and the coating layer may include a flexible polymer.

[0024] The flexible polymer may be at least one selected from the group consisting of fluorine-based polymers, polyurethane-based polymers, polyolefin-based polymers, and silicon-based polymers.

[0025] Another embodiment provides a method for manufacturing a battery module, the method including: manufacturing an insulating member; and disposing the insulating member between a plurality of cells so that an upper surface and a lower surface of the insulating member face an adjacent cell, respectively, wherein the insulating member includes a first insulating sheet, a second insulating sheet, and an expansion layer formed between the first insulating sheet and the second insulating sheet.

[0026] Yet another embodiment provides a battery pack including the battery module. [Effects of the Invention]

[0027] A battery module according to an embodiment can suppress the propagation of heat and flames to adjacent cells due to thermal runaway of a cell.

[0028] In addition, the heat insulating sheet provided in the battery module according to an embodiment has excellent compressibility in addition to heat insulating properties, and has mechanical strength and dimensional stability, thereby preventing the aerogel layer from falling off due to external impact, improving workability and preventing contamination of the mechanism. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a schematic diagram illustrating a structure of a battery module according to an embodiment. [Figure 2] 10 is a schematic diagram illustrating a state after an expansion layer has expanded in a battery module according to an embodiment. FIG. [Figure 3] 1 is a schematic diagram showing a cross-sectional structure of a heat insulating member according to one embodiment. [Figure 4] FIG. 10 is a schematic diagram showing the structure of a battery module according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0030] Although the present invention will be described in detail below so that those skilled in the art can easily implement the present invention, it should be understood that the present invention may be embodied in various different forms and is not limited to the embodiments set forth herein.

[0031] A battery module according to one embodiment includes a plurality of cells and insulating members respectively provided between the plurality of cells and arranged such that their upper and lower surfaces face adjacent cells, and the insulating members may include a first insulating sheet, a second insulating sheet, and an expansion layer formed between the first insulating sheet and the second insulating sheet.

[0032] The battery module having the above structure has excellent thermal insulation properties, as well as fire resistance and flame retardancy or non-combustibility, and can suppress the spread of heat and flame to adjacent cells due to thermal runaway of a cell. In addition, the thermal insulation sheet has excellent compressibility, ensuring mechanical strength and dimensional stability, and preventing the aerogel layer from falling off due to external impact, thereby improving workability and preventing contamination of the mechanism.

[0033] In one embodiment, the cell may be a secondary battery cell. The secondary battery may be, for example, a lithium secondary battery. The lithium secondary battery may be manufactured in various forms, such as a lithium ion battery, an all-solid-state battery, or a lithium metal battery. For example, the lithium secondary battery may have a structure in which a positive electrode plate and a negative electrode plate, each coated with a positive electrode active material and a negative electrode active material, are arranged with a separator sandwiched therebetween, and the positive electrode plate and negative electrode active material are sealed together with an electrolyte in a battery case to form a secondary battery cell. Depending on the shape of the battery case, the battery case may be classified as cylindrical, prismatic, or pouch-shaped, and a plurality of secondary battery cells may be connected in series or parallel to form a battery module.

[0034] Such secondary batteries require high stability. However, for example, if they are overcharged, decomposition reactions of the positive electrode active material or electrolyte and other side reactions may occur, and these reactions may release heat, eventually leading to an explosion of the secondary battery cell.

[0035] In this regard, in the present invention, an insulating member including a first insulating sheet, a second insulating sheet, and an expansion layer formed between the first insulating sheet and the second insulating sheet is arranged between each of the cells, and in addition to excellent insulating properties, the insulating member has fire resistance and flame retardancy or non-combustibility, and can suppress the spread of heat and flame to adjacent cells due to thermal runaway of a cell.

[0036] FIG. 1 is a schematic diagram showing a battery module having heat insulating members disposed between a plurality of cells.

[0037] 1, a battery module 1000 according to one embodiment may include a plurality of cells 100 and may include a thermal insulation member 200 provided between each of the plurality of cells 100. Here, the thermal insulation member 200 may include a first thermal insulation sheet 210, a second thermal insulation sheet 220, and an expansion layer 230 formed between the first thermal insulation sheet 210 and the second thermal insulation sheet 220. As a result, in the event of thermal runaway in one cell, the flame is first blocked to minimize the spread of the flame to other cells, thereby providing a battery module with improved safety, and further providing a secondary battery pack including the secondary battery module.

[0038] The insulating member includes an upper surface, a lower surface, and an edge side surface between the upper surface and the lower surface, and when the upper surface and the lower surface of the insulating member face adjacent cells, the edge side surface of the insulating member may positionally include an upper surface, a lower surface, a front surface, and a rear surface.

[0039] FIG. 2 is a schematic diagram showing a case where the expansion layer expands at a certain temperature or higher and flows out onto the upper and lower side surfaces of the heat insulating member.

[0040] Referring to FIG. 2, a battery module 1000 according to one embodiment includes a plurality of cells 100 and an insulating member 200 provided between each of the plurality of cells 100. The insulating member 200 may include a first insulating sheet 210, a second insulating sheet 220, and an expansion layer 230 formed between the first insulating sheet 210 and the second insulating sheet 220. When the ambient temperature rises above a certain temperature due to thermal runaway, the expansion layer 230 expands, and the plurality of cells 100 formed on both sides of the insulating member 200 also expand. As a result, the expansion layer 230 flows out from the upper and lower sides of the insulating member 200, forming an outflow portion 231 and filling the empty space within the battery module 1000, thereby preventing flame propagation.

[0041] In one embodiment, the first and second insulation sheets may each include a substrate and an aerogel layer formed on the substrate, wherein the substrates of the first and second insulation sheets may face the adjacent cells, and the aerogel layers may face the expanded layer.

[0042] FIG. 3 is a schematic diagram showing the structure of a heat insulating member according to one embodiment.

[0043] 3, the first insulation sheet 210 may include a first substrate 211 and a first aerogel layer 212 formed on the first substrate 211. The second insulation sheet 220 may include a second substrate 221 and a second aerogel layer 222 formed on the second substrate 221. Here, the first substrate 211 and the second substrate 221 each face the adjacent cell, and the first aerogel layer 212 and the second aerogel layer 222 each face the expansion layer 230, thereby forming an insulation member 200. When an insulation member having such a structure is included, the expansion layer spreads into and fills the empty space within the battery module during thermal runaway, thereby preventing the flame from spreading into the empty space.

[0044] Hereinafter, even without the notation of first or second, the heat insulating sheet can mean the first heat insulating sheet, the second heat insulating sheet, or both the first and second heat insulating sheets; the substrate can mean the first substrate, the second substrate, or both the first and second substrates; and the aerogel layer can mean the first aerogel layer, the second aerogel layer, or both the first and second aerogel layers.

[0045] The substrates of the first and second heat insulating sheets, i.e., the first substrate and the second substrate, may each be formed of one or more materials selected from the group consisting of resins, metals, and inorganic materials other than metals, or various substrates such as composites thereof can be used, and there is no limitation on the type. Furthermore, the form of the substrate is not particularly limited, and may be a film, thin film, sheet, or the like.

[0046] The resin may be, for example, one or more selected from the group consisting of polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and polyamide.

[0047] The metal may be, for example, one or more selected from the group consisting of copper, nickel, cobalt, iron, chromium, vanadium, palladium, ruthenium, rhodium, molybdenum, tungsten, iridium, silver, gold, and platinum. When using a substrate made of such a metal material, the substrate may be subjected to corrosion prevention treatment, insulation treatment, etc., as necessary.

[0048] The inorganic material may be one or more selected from the group consisting of calcium carbonate (CaCO3), talc, and mica.

[0049] As a specific example, the substrate may include an inorganic material, and more specifically, it may include mica, which can improve the heat insulating properties and durability of the heat insulating sheet.

[0050] The aerogel layers of the first and second insulation sheets, i.e., the first and second aerogel layers, may each comprise an aerogel, a fibrous support, and a functional material including a binder, a dispersant, or a combination thereof.

[0051] The aerogel has a BET specific surface area of ​​500 m 2 / g~1,000m 2 For example, the aerogel may have a BET specific surface area of ​​500 m 2 / g~950m 2 / g, 550m 2 / g~950m 2 / g, or 600m 2 / g~900m 2 By including an aerogel having a BET specific surface area value within the above range, scattering of the aerogel particles can be prevented and heat insulation can be improved.

[0052] The particle size of the aerogel may be 5 μm to 200 μm, 10 μm to 100 μm, or 20 μm to 60 μm. By including aerogel having a particle size within the above range, the heat insulating properties can be improved and heat transfer between the multiple cells can be delayed.

[0053] The content of the aerogel may be 10 to 90% by weight, 30 to 70% by weight, or 40 to 60% by weight, based on the total weight of the aerogel layer. By including the aerogel within this range, excellent heat insulating properties of the heat insulating sheet can be obtained.

[0054] Meanwhile, aerogel is a transparent or translucent cutting-edge material with a nanoporous structure. It has extremely low density and low thermal conductivity, and therefore has great potential as an insulating material. It is also considered a highly efficient super-insulating material that can be used in a variety of industrial fields.

[0055] Furthermore, the greatest advantage of aerogel is that it exhibits lower thermal conductivity than conventional organic insulation materials such as styrofoam and overcomes the fatal weaknesses of organic insulation materials, such as vulnerability to fire and the generation of toxic gases during a fire. However, aerogel is highly brittle, easily broken by even a small impact, and has very low strength. It is also difficult to process into very thin thicknesses and shapes. Therefore, despite its excellent insulating properties, it has been very difficult to manufacture insulation materials using aerogel alone. Therefore, in one embodiment, a fibrous support and a functional material containing a binder, a dispersant, or a combination thereof are included to improve the durability of the aerogel layer and prevent external impacts and dust generation during operation.

[0056] By including the fibrous support in the aerogel layer, the durability of the heat insulating sheet formed using the same can be improved.

[0057] The fibrous support may include fibers commonly used as supports for insulating materials. For example, the fibrous support may be one or more fibers selected from the group consisting of natural fibers, silica fibers, glass fibers, carbon fibers, graphite fibers, mineral fibers, and polymer fibers. As a specific example, the fibrous support may include, but is not limited to, glass fibers.

[0058] The natural fiber may be, for example, one or more fibers selected from the group consisting of hemp, jute, flax, coir, hemp, and cellulose.

[0059] The mineral fibers may be, for example, one or more mineral fibers selected from the group consisting of basalt, wollastonite, alumina, silica, slag, and rock.

[0060] The polymer fiber may be, for example, one or more selected from the group consisting of nylon, polyimide, polyamide, polybenzimidazole, polybenzoxazole, polyamideimide, polyethyleneterephthalate, polybutyleneterephthalate, polyester, polyethylene (PE), and polypropylene (PP). Specific examples of the polymer fiber include, but are not limited to, one or more selected from the group consisting of polyimide, polyamide, and polybenzimidazole.

[0061] The fibrous support may be, for example, in the form of wool or chopped strands, but is not limited thereto.

[0062] The diameter of the fibrous support may be, for example, 0.1 μm to 20 μm, 0.1 μm to 15 μm, 0.1 μm to 5 μm, 1 μm to 15 μm, or 3 μm to 10 μm. By including a fibrous support having a diameter within the above range, the structure of the aerogel layer can be made stronger, and production costs can be reduced.

[0063] The content of the fibrous support may be 5 to 70% by weight, 25 to 60% by weight, or 30 to 50% by weight, based on the total weight of the aerogel layer. When an aerogel layer containing a fibrous support within the above range is formed to produce a heat insulating sheet, durability can be improved.

[0064] The binder may include a water-based polymer binder. For example, the water-based polymer binder may be one or more selected from the group consisting of aqueous polymers, anionic water-soluble polymers, cationic water-soluble polymers, and water-dispersible polymers.

[0065] The aqueous polymer may be, for example, one or more selected from the group consisting of polyvinyl alcohol, polyethylene oxide, polyacrylamide, and polyvinylpyrrolidone, but is not limited thereto.

[0066] The anionic water-soluble polymer may be one or more selected from the group consisting of polymers having functional groups such as carboxylic acid, sulfonic acid, sulfate, phosphate, and salts thereof. For example, the anionic water-soluble polymer may be a polymer having a carboxylic acid group, and a specific example thereof may include, but is not limited to, polymaleic acid.

[0067] The cationic water-soluble polymer may be at least one selected from the group consisting of polymers having functional groups such as amine, ammonium, phosphonium, sulfonium, and salts thereof. For example, the cationic water-soluble polymer may be a polymer having an amine group, and specific examples thereof include, but are not limited to, at least one selected from the group consisting of polyethylene amine and polyamine.

[0068] The water-dispersible polymer may be at least one selected from the group consisting of water-dispersible polyurethane and water-dispersible polyester, but is not limited thereto.

[0069] The binder may include a water-based polymer and a water-dispersible polymer, for example, a water-based polymer having binder properties and dispersing properties, and a water-dispersible polyurethane having fire-resistant properties, and a specific example thereof may include polyvinyl alcohol and water-dispersible polyurethane.

[0070] The weight ratio of the aqueous polymer to the water-dispersible polymer may be 1:1 to 1:5, 1:1 to 1:4, or 1:2 to 1:3. When the weight ratio of the aqueous polymer to the water-dispersible polymer is within this range, the heat insulation properties, dust resistance, and compressibility of the heat insulating sheet can be further improved, as well as the fire resistance and mechanical properties.

[0071] The content of the binder may be 0.5 to 20% by weight, 2 to 15% by weight, or 8 to 15% by weight, based on the total weight of the aerogel layer. A heat insulating sheet including an aerogel layer containing a binder within this range can have improved dust resistance.

[0072] The dispersant may be at least one selected from the group consisting of a surfactant, a silane coupling agent, and a phosphate salt. Specific examples of the dispersant include, but are not limited to, at least one of a nonionic surfactant, an anionic surfactant, an amphoteric surfactant, a natural surfactant such as lecithin, and a phosphate salt.

[0073] When the dispersant is further included, the dispersion of the aerogel is improved during the preparation of the aerogel layer, and the aerogel and the fibrous support can be uniformly dispersed.

[0074] The content of the dispersant may be 0.1 to 6 wt %, 0.1 to 5 wt %, or 0.1 to 3 wt %, based on the total weight of the aerogel layer. By including a dispersant within this range, an aerogel layer can be produced at low cost, and a heat insulating sheet having excellent heat insulating properties, uniformity, and dust resistance can be produced using the aerogel layer.

[0075] In one embodiment, the binder and the dispersant may be included in a weight ratio of 1:0.001 to 1:0.67, 1:0.001 to 1:0.5, or 1:0.001 to 1:0.3. When the binder and the dispersant are used in combination in a weight ratio within this range, the aerogel may be more uniformly dispersed in the aerogel layer.

[0076] In one embodiment, the aerogel layer may contain 25% by weight to 60% by weight of the fibrous support, 30% by weight to 70% by weight of the aerogel, and 2% by weight to 15% by weight of the binder, relative to the total amount of the aerogel layer.

[0077] As a specific example, the aerogel layer may contain 30 to 50% by weight of the fibrous support, 40 to 60% by weight of the aerogel, and 8 to 15% by weight of the binder, relative to the total weight of the aerogel layer. When the aerogel layer is formed within these ranges, excellent heat insulation can be achieved, durability can be improved, the bonding strength between the fibrous support and the aerogel can be improved, and dust generation can be prevented.

[0078] In one embodiment, the aerogel layer may contain 25% by weight to 60% by weight of the fibrous support, 30% by weight to 70% by weight of the aerogel, 2% by weight to 15% by weight of the binder, and 0.1% by weight to 3% by weight of the dispersant, relative to the total amount of the aerogel layer.

[0079] As a specific example, the aerogel layer may contain 30 to 50% by weight of the fibrous support, 40 to 60% by weight of the aerogel, 5 to 10% by weight of the binder, and 0.1 to 2% by weight of the dispersant, relative to the total amount of the aerogel layer. When the aerogel layer is formed within these ranges, excellent heat insulation can be achieved, durability can be improved, the bonding strength between the fibrous support and the aerogel can be improved, and dust generation can be prevented.

[0080] In one embodiment, the expandable layer may be formed of at least one material selected from the group consisting of a foam material that expands when the ambient temperature increases to 100°C to 200°C, and a flame-retardant material having a melting temperature of 60°C to 100°C.

[0081] The foaming agent is not particularly limited as long as it foams and expands in volume when the ambient temperature increases to, for example, 100°C to 200°C, 120°C to 180°C, or 120°C to 170°C, and may include, for example, one or more foaming agents selected from the group consisting of expanded graphite, organic foaming agents, and inorganic foaming agents. Specific examples of the organic foaming agent include one or more selected from the group consisting of azodicarbonamide, dinitropentamethylenetetramine, and oxybis(benzenesulfonylhydrazide), and the inorganic foaming agent includes one or more selected from the group consisting of bicarbonates, carbonates, and organic acid salts.

[0082] The foaming agent may be mixed with a polymer to form a coating solution. The polymer may be any polymer capable of controlling the desired expanded thickness of the expandable layer and the foaming trigger temperature of the foaming agent, and may be, for example, at least one polymer selected from the group consisting of polyimide, polyamide, polybenzimidazole, polybenzoxazole, polyamideimide, polyurethane, polyethylene terephthalate, polybutylene terephthalate, polyester, polyethylene (PE), and polypropylene (PP).

[0083] Here, the coating liquid containing the foaming material and the polymer material may foam and expand in volume when the ambient temperature increases to, for example, 100°C to 200°C, 120°C to 180°C, or 120°C to 170°C.

[0084] The foaming material and the polymeric material may form a coating liquid in a weight ratio of 1:9 to 5:5, 1:9 to 4:6, or 1:9 to 3:7.

[0085] The flame retardant material is not particularly limited as long as it has a melting temperature of, for example, 60° C. to 100° C. or 80° C. to 100° C., and may be, for example, one or more selected from the group consisting of polyurethane, polyvinyl chloride, and polymers having a flame retardant dispersed therein. Here, the flame retardant may include the types of flame retardants described below.

[0086] When the expansion layer is formed using the foam material and the flame-retardant material, the expansion layer quickly leaks from the edge side of the insulating member to the upper and lower portions under certain temperature conditions, filling empty spaces within the battery module and thereby preventing the spread of flames. Here, the upper and lower portions may refer to the upper and lower portions based on the shape in which the insulating member is arranged.

[0087] The expansion layer may be formed to a thickness of 1% to 30%, 5% to 25%, or 10% to 17% of the total thickness of the heat insulating member. By forming the expansion layer with a thickness within this range, it is possible to effectively prevent flame propagation in the event of thermal runaway of one cell.

[0088] The expandable layer expands under certain temperature conditions and flows out from the side of the thermal insulation member, and the length of the outflow portion formed by the expandable layer flowing out from the side of the thermal insulation member may be 500% to 3000%, 1000% to 2500%, or 1300% to 2000% of the thickness of the expandable layer before expansion. Specifically, the expandable layer expands when the ambient temperature rises above a certain level, and the length of the outflow portion after expansion may increase 5 to 30 times, 10 to 25 times, or 13 to 20 times the thickness before expansion.

[0089] The battery module may include an empty space other than the space in which the cells and the heat insulating member are formed, and the length of the outflow portion may be 200% or more, 200% to 500%, or 200% to 400% of the height of the empty space formed at the upper part of the battery module. Specifically, the length of the outflow portion may be 2 times or more, 2 times to 5 times, or 2 times to 4 times the height of the empty space formed at the upper part of the battery module.

[0090] In one embodiment, the battery module includes an empty space other than the space where the cells and the insulating member are disposed, and further includes a coating layer formed to cover a side surface of the insulating member in the empty space formed in the lower part of the battery module, the coating layer may include a flexible polymer. By forming the coating layer, an expansion layer between the first insulating sheet and the second insulating sheet is concentrated and flows upward during heat exposure, and in this case, a flame moving upward can be effectively blocked.

[0091] FIG. 4 is a schematic view showing a battery module including a coating layer formed to cover the side surface of the heat insulating member in an empty space formed under the battery module.

[0092] 4, a battery module 1000 according to an embodiment may include a plurality of cells 100 and may include a thermal insulation member 200 provided between each of the plurality of cells 100. Here, the thermal insulation member 200 may include a first thermal insulation sheet 210, a second thermal insulation sheet 220, and an expansion layer 230 formed between the first thermal insulation sheet 210 and the second thermal insulation sheet 220. The battery module 1000 may also include a coating layer 300 formed to cover a side surface of the thermal insulation member 200 in an empty space formed at the bottom of the battery module 1000. As a result, when a thermal runaway occurs in one cell, the expansion layer 230 effectively flows upward to block the flame moving upward, thereby effectively suppressing the propagation of the flame to other cells.

[0093] The flexible polymer is not particularly limited as long as it is a polymer having flexibility, and may be, for example, one or more types selected from the group consisting of fluorine-based polymers, polyurethane-based polymers, polyolefin-based polymers, and silicon-based polymers.

[0094] The fluoropolymer may be, for example, one or more selected from the group consisting of polytetrafluoroethylene (PTFE), perfluoroalkoxyethylene (PFA), fluoroethylenepropylene (FEP), ethylene-tetrafluoroethylene (ETFE), polyvinyldene fluoride (PVDF), and polychlorotrifluoroethylene (PCTFE). The fluoropolymer may be a substance that is flexible and independently flame-retardant.

[0095] The polyurethane polymer is not particularly limited as long as it is a conventional polyurethane produced by polymerization of a polyol and a polyisocyanate. Here, the polyol may be, for example, a conventional polyol used in the production of polyurethane, and may be one or more selected from the group consisting of polyether polyol, polyester polyol, polyamide polyol, polyesteramide polyol, polythioether polyol, polycarbonate polyol, polyacetal polyol, polyolefin polyol, polysiloxane polyol, acrylic polyol, and silicone polyol. Furthermore, the polyisocyanate may include, for example, a typical polyisocyanate used in the production of polyurethane, and may be one or more selected from the group consisting of toluene diisocyanate, isophorone diisocyanate, cyclohexane-1,4-diisocyanate, 4,4-dicyclohexylmethane diisocyanate, 4,4-di(aminocyclohexyl)methane hexamethylene diisocyanate, 1,4-phenylene diisocyanate, 4,4-diphenylmethane diisocyanate, xylene diisocyanate, 1,5-naphthalene diisocyanate, trimethylhexamethylene diisocyanate, and norborane diisocyanate.

[0096] The polyolefin polymer may be, for example, one or more selected from the group consisting of polyethylene, polypropylene, polybutylene, polypentene, polyvinylidene fluoride, and polymethyl methacrylate.

[0097] The silicon-based polymer may be, for example, one or more selected from the group consisting of polydimethylsiloxane, polymethylethylsiloxane, polydiethylsiloxane, polymethylphenylsiloxane, polydiphenylsiloxane, and polyethylphenylsiloxane.

[0098] The coating layer may further include a flame retardant, and the type of the flame retardant is not particularly limited and may be, for example, at least one selected from the group consisting of inorganic flame retardants, phosphorus-based flame retardants, nitrogen compound-based flame retardants, silicon-based flame retardants, melamine-based flame retardants, and halogen-based flame retardants.

[0099] The inorganic flame retardant may include a metal oxide, a metal hydroxide, or a combination thereof, for example, but is not limited to, one or more selected from the group consisting of silicon oxide, magnesium hydroxide, aluminum hydroxide, antimony oxide, sodium carbonate, zinc oxide, iron oxide, tin oxide, zinc borate, and calcium borate.

[0100] The phosphorus-based flame retardant includes a typical phosphorus-containing flame retardant, and may be, for example, at least one selected from the group consisting of phosphate, phosphonate, phosphinate, phosphine oxide, phosphazene, and ammonium salts thereof, but is not limited thereto.

[0101] The phosphorus-based flame retardant may have two or more hydroxyl groups at the functional group terminal. As a specific example, the phosphorus-based flame retardant may include ammonium polyphosphate having a multifunctional hydroxyl group. The use of a phosphorus-based flame retardant having a multifunctional hydroxyl group can provide excellent flame retardancy.

[0102] The nitrogen compound-based flame retardant may be at least one selected from the group consisting of an aliphatic amine compound, an aromatic amine compound, a nitrogen-containing heterocyclic compound, a cyanide compound, an aliphatic amide, an aromatic amide, urea, and thiourea, but is not limited thereto.

[0103] The silicone-based flame retardant may include a silicone resin, a silicone oil, or a combination thereof. The silicone resin may include a resin having an RSiO structure, where R represents an alkyl group having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, or a propyl group; an aromatic group; or a substituent in which one or more hydrogen atoms of the alkyl group and the aromatic group are substituted with a vinyl group. The silicone oil may be, but is not limited to, one or more selected from the group consisting of polydimethylsiloxane and modified polydimethylsiloxane in which at least one methyl group on the side chain or terminal of the polydimethylsiloxane is modified with one or more of a hydrogen atom, an alkyl group, a cyclohexyl group, a phenyl group, a benzyl group, an epoxy group, a polyether group, a carboxyl group, a mercapto group, a chloroalkyl group, an alkyl alcohol ester group, an alcohol group, an allyl group, a vinyl group, and a trifluoromethyl group.

[0104] The melamine-based flame retardant may be at least one selected from the group consisting of melamine phosphate, dimelamine phosphate, melamine pyrophosphate, and melamine cyanurate, but is not limited thereto.

[0105] The halogen-based flame retardant may be any halogen-based compound that can function as a flame retardant, and may be, but is not limited to, at least one selected from the group consisting of decabromodiphenyl ether, decabromodiphenylethane, tetrabromobisphenol-A, tetrabromobisphenol-A epoxy oligomer, octabromotrimethylphenylindane, ethylene-bis-tetrabromophthalimide, tris(tribromophenol)triazine, and brominated polystyrene.

[0106] The content of the flame retardant may be 1 to 10 wt %, 2 to 8 wt %, or 3 to 6 wt % relative to the total weight of the coating layer. By forming a coating layer containing a flame retardant within this range, dust generation from the aerogel can be prevented and the flame retardancy or non-combustibility of the heat insulating member can be improved.

[0107] A method for manufacturing a battery module according to one embodiment includes manufacturing an insulating member and disposing the insulating member between a plurality of cells so that an upper surface and a lower surface of the insulating member face adjacent cells, respectively, and the insulating member may include a first insulating sheet, a second insulating sheet, and an expansion layer formed between the first insulating sheet and the second insulating sheet.

[0108] In one embodiment, the step of manufacturing the insulation member may include the steps of manufacturing a first insulation sheet, manufacturing a second insulation sheet, and laminating an expansion layer between the first insulation sheet and the second insulation sheet.

[0109] The step of manufacturing the first insulation sheet may include the steps of forming a first substrate and applying an aerogel composition onto the first substrate to form a first aerogel layer.

[0110] The step of producing the second insulation sheet may include the steps of forming a second substrate and applying an aerogel composition onto the second substrate to form a second aerogel layer.

[0111] The first and second substrates may be as described above, and the size and shape may be appropriately adjusted depending on the cell structure.

[0112] The aerogel composition may be prepared by mixing a solvent with a functional material, such as a binder, a dispersant, or a combination thereof, to prepare a solvent mixture, mixing the solvent mixture with an aerogel to prepare an aerogel mixture, and mixing the aerogel mixture with a fibrous support to prepare an aerogel composition, thereby forming a first aerogel layer, a second aerogel layer, or both the first and second aerogel layers.

[0113] In the step of preparing the solvent mixture by mixing the functional material with the solvent, a binder may be mixed with the solvent, or a binder and a dispersant may be mixed with the solvent.

[0114] The solvent may be one or more selected from the group consisting of polar solvents and non-polar solvents.

[0115] The polar solvent may be one or more selected from the group consisting of water and alcohol-based solvents.

[0116] The water may be, for example, one or more types selected from the group consisting of purified water and ultrapure water.

[0117] The alcohol-based solvent may be, for example, one or more selected from the group consisting of methanol, ethanol, propanol, pentanol, butanol, hexanol, ethylene glycol, propylene glycol, diethylene glycol, and glycerol, but is not limited thereto.

[0118] The non-polar solvent may include a hydrocarbon solvent, for example, at least one selected from the group consisting of hexane, pentane, heptane, toluene, and benzene, and more preferably, an alkane solvent such as hexane, or a mixture containing an alkane solvent, but is not limited thereto.

[0119] The solvent may include water. Using water as a solvent can effectively reduce raw material costs and post-processing costs. However, when water is used as a solvent, it can be difficult to mix with the hydrophobic aerogel. In one embodiment, however, the aerogel is uniformly dispersed by controlling the mixing step design, mixing conditions, and the addition and amounts of binder and dispersant. By uniformly dispersing the aerogel in this manner in the composition, it is possible to form a thin aerogel layer with excellent heat insulation, durability, and low dust properties without using a large amount of binder.

[0120] The solvent may be contained in such a way that the weight ratio of the solvent to the total solid content of the aerogel composition is 1:1 to 1:90. For example, the weight ratio of the solvent to the total solid content of the aerogel composition may be 1:50 to 1:70, 1:20 to 1:30, or 1:2 to 1:10. By controlling the weight ratio of the solvent to the total solid content within the above range, it is possible to achieve a balance between dispersibility, coatability, and phase stability.

[0121] The specific explanation regarding the binder and dispersant may be as described above.

[0122] In the step of preparing the aerogel mixture by mixing the solvent mixture and the aerogel, the specific description of the aerogel may be the same as that described above.

[0123] In the step of preparing an aerogel composition by mixing the aerogel mixture and the fibrous support, the specific description of the fibrous support may be the same as described above.

[0124] In each of the steps of preparing a solvent mixture by mixing a functional material, such as a binder, a dispersant, or a combination thereof, with the solvent, preparing an aerogel mixture by mixing the solvent mixture with an aerogel, and preparing an aerogel composition by mixing the aerogel mixture with a fibrous support, a mixer may be used during mixing. For example, the mixer may include, but is not limited to, a planetary mixer, a PD mixer, a thinky mixer, a C-mixer, etc.

[0125] For example, a planetary mixer may be used to mix the solvent mixture and the aerogel. By using the planetary mixer to mix the solvent mixture and the aerogel, the aerogel can be uniformly dispersed in the solvent.

[0126] The planetary mixer may be a device that can be used to mix or stir different materials to produce a homogeneous mixture, and may include blades that can move in planetary motion.

[0127] In one embodiment, the planetary mixer may include one or more planetary blades and one or more high-speed dispersion blades. As a specific example, the planetary mixer may include one or more planetary blades and one or more high-speed dispersion blades.

[0128] The planetary blades and high-speed dispersion blades rotate continuously about their axes, and the rotational speed may be expressed in units of rotations per minute (rpm).

[0129] In one embodiment, the planetary mixer may include a first blade and a second blade having different rotation axes. For example, the first blade may be a low-speed blade, and the second blade may be a high-speed blade. Here, low speed and high speed refer to the relative rotation speeds of the first blade and the second blade. As a specific example, the first blade may be an open blade, and the second blade may be a Despa blade.

[0130] The rotation speed of the first blade may be, for example, 10 rpm to 100 rpm, 10 rpm to 60 rpm, or 30 rpm to 70 rpm, and the rotation speed of the second blade may be, for example, 100 rpm to 2000 rpm, 100 rpm to 1000 rpm, 300 rpm to 1700 rpm, or 500 rpm to 1700 rpm.

[0131] When the functional material is mixed with the solvent, the rotation speed of the first blade may be 10 to 60 rpm, 20 to 50 rpm, or 30 to 40 rpm, and the rotation speed of the second blade may be 300 to 1700 rpm, 600 to 1000 rpm, or 700 to 800 rpm. Mixing the solvent and functional material in this manner produces a solvent mixture in which the binder, dispersant, or a combination thereof is uniformly dispersed, making it easier to mix the aerogel in the subsequent step.

[0132] When mixing the solvent mixture and the aerogel powder, the rotation speed of the first blade of the mixer may be 30 rpm to 70 rpm, 40 rpm to 70 rpm, or 60 rpm to 70 rpm, and the rotation speed of the second blade may be 500 rpm to 1700 rpm, 600 rpm to 1600 rpm, or 800 rpm to 1500 rpm. By adding the aerogel powder to the solvent mixture and mixing it as described above, it is possible to prevent the aerogel powder from agglomerating with each other and induce uniform dispersion.

[0133] When mixing the aerogel mixture and the fibrous support, the rotation speed of the first blade of the mixer may be 10 rpm to 60 rpm, 20 rpm to 50 rpm, or 30 rpm to 40 rpm, and the rotation speed of the second blade may be 300 rpm to 1700 rpm, 400 rpm to 1500 rpm, or 800 rpm to 1200 rpm. Mixing the aerogel mixture and the fibrous support in this manner removes air bubbles from the composition, adjusts the viscosity, and facilitates dispersion of the fibrous support among the uniformly dispersed aerogel, allowing the aerogel to exist in a form in which it surrounds the fibrous support in the composition. The presence of a binder between the aerogel and the fibrous support can improve the bonding strength between the aerogel and the fibrous support.

[0134] By forming an aerogel layer using a method according to an embodiment, not only the heat insulating properties but also the durability are improved, and it is possible to prevent the aerogel from falling off and generating dust when manufacturing an insulating member, installing it inside an apparatus, or when external vibrations occur.

[0135] In one embodiment, the step of forming an expansion layer between the first and second insulation sheets and laminating them may involve arranging the first aerogel layer of the first insulation sheet and the second aerogel layer of the second insulation sheet so that they face each other, and forming an expansion layer between the first and second aerogel layers.

[0136] The expanded layer may be formed by coating, casting, etc. Specifically, the expanded layer may be formed on the first aerogel layer of the first insulation sheet by coating, and the second aerogel layer of the second insulation sheet may be laminated on the expanded layer so that they face each other, and then the two sheets may be attached to each other to manufacture the insulation member.

[0137] In one embodiment, in the step of disposing the insulating members between the plurality of cells so that the upper and lower surfaces of the insulating members face the adjacent cells, respectively, the manner in which the plurality of cells are disposed is not specifically limited, and the cells may be disposed appropriately depending on the type of battery.

[0138] A heat insulating member may be disposed between each of the plurality of cells, and the first or second substrate of the heat insulating member may have an upper surface and a lower surface, and the upper surface and the lower surface may be disposed so as to face the adjacent cell.

[0139] An embodiment includes a battery pack including the battery module, wherein a plurality of battery modules may be disposed within the battery pack.

[0140] Specific examples of the present invention will be presented below. However, the examples described below are merely for the purpose of specifically illustrating or explaining the present invention, and the present invention should not be limited thereto. Furthermore, since the contents not described here can be sufficiently inferred by those skilled in the art, a description thereof will be omitted.

[0141] (battery module manufacturing) Example 1 1.Insulation material manufacturing Polyvinyl alcohol (Sigma Aldrich, Poly(vinyl alcohol)) was added as a binder to ultrapure water as a solvent, and then mixed with an open blade at 30 rpm and a despa blade at 700 rpm to produce a solvent mixture. 2 An aerogel mixture was prepared by adding aerogel (1 / g) and mixing with an open blade at 70 rpm and a Despa blade at 1500 rpm. Glass wool was added to the aerogel mixture and mixed with an open blade at 30 rpm and a Despa blade at 1200 rpm to prepare an aerogel composition. A planetary mixer (DIENTEK, PT-005) was used for mixing.

[0142] The solid content of the prepared aerogel composition was confirmed to be 50 wt % aerogel, 40 wt % glass wool, and 10 wt % polyvinyl alcohol.

[0143] The prepared aerogel composition was applied as a slurry onto a 0.3 mm thick mica sheet (Famica, Muscovite) to prepare a heat insulating sheet. Two such heat insulating sheets were prepared and used as the first and second heat insulating sheets.

[0144] The first and second insulation sheets were placed with the aerogel composition-coated surfaces facing each other, and an expansion layer was formed between them by a coating method using a water-based thermally decomposable expansion coating liquid (Lord, Sipiol FR220), thereby producing an insulation member.

[0145] It was confirmed that the total thickness of the manufactured heat insulating member was 3 mm, and the thickness of the expansion layer was 0.3 mm.

[0146] 2. Battery module manufacturing A plurality of cells are arranged in a battery module, and a heat insulating member having an expansion layer formed thereon is arranged between the plurality of cells.

[0147] Example 2 The same method as in Example 1 was used to produce the expanded layer, except that the thickness of the expanded layer was 0.1 mm.

[0148] Example 3 The same method as in Example 1 was used to produce the expanded layer, except that the thickness of the expanded layer was 0.5 mm.

[0149] Example 4 The same method as in Example 1 was used to produce the expanded layer, except that the thickness of the expanded layer was 0.8 mm.

[0150] Example 5 The fabrication method was the same as in Example 1, except that a foam coating solution containing a foam material (UNICELL-5PT, manufactured by Dongjin Semichem) and polyimide (PHOTONECE, manufactured by Toray) in a ratio of 2:8 was used.

[0151] Comparative Example 1 The manufacturing method was the same as that of Example 1, except that the expansion layer was not formed.

[0152] (Experimental example) Experimental example 1: Heat insulation evaluation The heat insulating members manufactured in Examples 1 to 5 and Comparative Example 1 were used to evaluate the heat insulating properties.

[0153] Specifically, each insulation sheet was placed between a pair of opposing 1T thick aluminum plates, which were then placed on a heat press. The upper plate of the heat press was heated to 350°C, while the lower plate of the heat press was not heated and kept at the starting temperature of 40°C. A pressure of 20 kN was then applied to the lower plate of the heat press, and the maximum temperature of the lower plate of the heat press was measured after 11 minutes, and the results are shown in Table 1 below.

[0154] Experimental example 2: Compressibility evaluation The heat insulating members manufactured in Examples 1 to 5 and Comparative Example 1 were used to evaluate compression performance.

[0155] Specifically, the thickness ratio when a load of 5kN was applied was measured based on the thickness when a load of 40kN was applied using UTM equipment, and is shown in Table 1 below.

[0156] Experimental Example 3: Expansion evaluation 1. Expansion temperature The expansion temperatures of the expansion layers of the heat insulating members manufactured in Examples 1 to 5 and Comparative Example 1 were measured. Specifically, the expansion temperatures were measured by exposing the materials to a hot plate at intervals of 50°C, and the temperatures at which foaming was triggered were shown in Table 1 below.

[0157] 2. Length of outflow section after inflation The heat insulating members manufactured in Examples 1 to 5 and Comparative Example 1 were used to evaluate the expansion performance of the expansion layer.

[0158] Specifically, the temperature of the upper mold in the UTM equipment was set to 800°C, and a load of 1.3 MPa was applied to each insulation member for 1 minute to compress it. The expanded layer expanded and flowed out from the side of the insulation member, and the average length of the expanded part formed by the expansion layer flowing out from the side of the insulation member and the thickness of the insulation member after compression were measured and are shown in Table 1 below.

[0159] Experimental example 4: Heat propagation evaluation The battery modules manufactured in Examples 1 to 5 and Comparative Example 1 were evaluated for flame propagation.

[0160] Specifically, the heat transfer was evaluated using a 50 Ah rectangular (NCM 811 / Graphite) 2-cell simple module with an upper cover and a 1.5 mm gap between the top of the cell and the cover, using a method of heat transfer under nail penetration conditions. The results are shown in Table 1 below.

[0161] [Table 1]

[0162] Referring to Table 1 above, it was confirmed that Examples 1 and 3 had excellent heat insulation, compressibility, and heat transfer prevention properties. On the other hand, in Example 2, the expanded layer was formed thin, resulting in a small amount of outflow, and it was confirmed that some heat transfer occurred. Also, in Example 4, the expanded layer was formed thick, resulting in a decrease in the thickness of the insulating material after outflow, and it was confirmed that heat transfer occurred due to a decrease in insulating performance. Also, in Example 5, the expansion temperature of the internal expanded layer was high, resulting in less outflow compared to the heat transferred inside the insulating sheet, and it was confirmed that some heat transfer occurred.

[0163] On the other hand, Comparative Example 1 did not include an expansion layer and was unable to prevent heat propagation at all.

[0164] Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made within the scope of the claims, the detailed description of the invention, and the accompanying drawings, and it is natural that these modifications also fall within the scope of the present invention. [Explanation of symbols]

[0165] 100 cells 200 Heat insulating material 210 First Heat Insulation Sheet 211 1st base material 212 First aerogel layer 220 Second insulation sheet 221 Second base material 222 Second aerogel layer 230 Expansion layer 231 Outflow 300 coating layers 1000 Battery Module

Claims

1. A plurality of cells; a heat insulating member provided between each of the plurality of cells, the heat insulating member being disposed so that an upper surface and a lower surface thereof face an adjacent cell, The heat insulating member includes a first heat insulating sheet, a second heat insulating sheet, and an expansion layer formed between the first heat insulating sheet and the second heat insulating sheet, The first and second heat insulating sheets each include a substrate and an aerogel layer formed on the substrate, The aerogel layers of the first and second heat insulating sheets each include an aerogel; a fibrous support; and a functional material including a binder or a combination of a binder and a dispersant; The battery module, wherein the binder comprises a water-based polymer binder.

2. The battery module according to claim 1 , wherein the cells are secondary battery cells.

3. 2. The battery module according to claim 1, wherein the substrates of the first and second insulation sheets face the adjacent cells, and the aerogel layers face the expansion layers.

4. The battery module according to claim 1 , wherein the base material of each of the first insulating sheet and the second insulating sheet is at least one selected from the group consisting of resin, metal, and inorganic material other than metal.

5. The aerogel has a BET specific surface area of ​​500 m 2 / g to 1,000m 2 The battery module according to claim 1 , wherein the tensile strength is 1 / g.

6. 2. The battery module according to claim 1, wherein the fibrous support is at least one selected from the group consisting of natural fibers, silica fibers, glass fibers, carbon fibers, graphite fibers, mineral fibers, and polymer fibers.

7. 2. The battery module according to claim 1, wherein the aerogel layer comprises, relative to a total amount of the aerogel layer, 10% by weight to 90% by weight of the aerogel, 5% by weight to 70% by weight of the fibrous support, and 0.5% by weight to 20% by weight of the functional material.

8. A plurality of cells; a heat insulating member provided between each of the plurality of cells, the heat insulating member being disposed so that an upper surface and a lower surface thereof face an adjacent cell, The heat insulating member includes a first heat insulating sheet, a second heat insulating sheet, and an expansion layer formed between the first heat insulating sheet and the second heat insulating sheet, The expansion layer is at least one selected from the group consisting of foam materials that expand when the ambient temperature increases to 100°C to 200°C, and flame-retardant materials having a melting temperature of 60°C to 100°C.

9. the foaming material is at least one selected from the group consisting of expanded graphite, organic foaming agents, and inorganic foaming agents; the organic blowing agent is at least one selected from the group consisting of azodicarbonamide, dinitropentamethylenetetramine, and oxybis(benzenesulfonylhydrazide); The battery module according to claim 8 , wherein the inorganic foaming agent is at least one selected from the group consisting of bicarbonates, carbonates, and organic acid salts.

10. The battery module according to claim 8 , wherein the flame-retardant material is at least one selected from the group consisting of polyurethane, polyvinyl chloride, and a polymer having a flame retardant dispersed therein.

11. The battery module according to claim 1 , wherein the thickness of the expansion layer is 1% to 30% of the total thickness of the insulating member.

12. 2. The battery module of claim 1, wherein, when the expansion layer expands, the expansion layer flows out from a side surface of the insulating member to form an outflow portion, and the length of the outflow portion from the side surface of the insulating member is 500% to 3000% of the thickness of the expansion layer.

13. A plurality of cells; a heat insulating member provided between each of the plurality of cells, the heat insulating member being disposed so that an upper surface and a lower surface thereof face an adjacent cell, The heat insulating member includes a first heat insulating sheet, a second heat insulating sheet, and an expansion layer formed between the first heat insulating sheet and the second heat insulating sheet, the battery module includes an empty space other than a space in which the cells and the heat insulating members are disposed, a coating layer formed in a space formed under the battery module to cover a side surface of the heat insulating member; The battery module, wherein the coating layer comprises a flexible polymer.

14. The battery module according to claim 13, wherein the flexible polymer is at least one selected from the group consisting of a fluorine-based polymer, a polyurethane-based polymer, a polyolefin-based polymer, and a silicone-based polymer.

15. manufacturing an insulating element; and disposing the heat insulating member between the plurality of cells so that the upper surface and the lower surface of the heat insulating member face the adjacent cells, respectively; 2. The method of manufacturing a battery module according to claim 1, wherein the heat insulating member includes a first heat insulating sheet, a second heat insulating sheet, and an expansion layer formed between the first heat insulating sheet and the second heat insulating sheet.

16. A battery pack comprising a battery module described in any one of claims 1 to 14.

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