Thermal insulation composition for battery devices, method for manufacturing the same, sheet manufactured using the same, and battery module containing the same.

Abstract

To provide a battery module having superior thermal insulation, along with fire resistance, flame retardancy, or non-flammability, for inhibiting heat propagation to adjacent cells due to thermal runaway of the battery, a method of manufacturing the battery module, and a battery pack including the battery module.SOLUTION: The present invention relates to a battery module including a plurality of cells, an insulation sheet between the plurality of cells, the insulation sheet having an upper surface and a lower surface disposed so as to face respective cells adjacent thereto, and a refractory layer formed on at least one edge surface between the upper and lower surfaces of the insulation sheet, wherein the refractory layer includes an inorganic binder. The present invention also 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 method for manufacturing the same, and a battery pack containing the same. [Background technology]

[0002] Rechargeable batteries are power storage systems that offer excellent energy density by converting electrical energy into chemical energy for storage. Unlike primary batteries, which cannot be recharged, rechargeable 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 increased due to the need to prevent environmental pollution, and high-capacity rechargeable batteries are being adopted in electric vehicles. Such rechargeable batteries require characteristics such as high density, high output, and stability.

[0003] On the other hand, in the case of a large number of high-capacity cells, such as lithium-ion batteries, one cell may overheat and experience thermal runaway for any reason, adversely affecting the other adjacent cells. Therefore, thermal insulation between adjacent cells is required.

[0004] Conventionally, plates or insulating resin boards were placed between cells to provide insulation and heat retention between adjacent cells.

[0005] The information disclosed above in the technology that forms the background of such inventions is merely for the purpose of improving the understanding of the background of the present invention, and therefore may include information that does not constitute prior art. [Overview of the project] [Problems that the invention aims to solve]

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

[0007] One embodiment provides a battery module comprising a plurality of cells, an insulating sheet provided between each of the plurality of cells, with its upper and lower surfaces facing the adjacent cell, and a fire-resistant layer formed on one or more of the edge surfaces between the upper and lower surfaces of the insulating sheet, wherein the fire-resistant layer comprises an inorganic binder.

[0008] The cell may be a secondary battery cell.

[0009] The heat insulating sheet may include a first substrate, a second substrate, and an aerogel layer provided between the first and second substrates.

[0010] Each of the first and second substrates may include a resin, a metal, an inorganic material other than a metal, or a composite thereof.

[0011] The aerogel layer may include an aerogel, a fibrous support, and a functional substance comprising a binder, a dispersant, or a combination thereof.

[0012] The aerogel has a BET specific surface area of ​​500 m². 2 / g~1,000m 2 / g is acceptable.

[0013] The fibrous support may be one or more selected from the group consisting of natural fibers, silica fibers, glass fibers, ceramic fibers, carbon fibers, graphite fibers, mineral fibers, and polymer fibers.

[0014] The binder includes an aqueous polymer binder, and the aqueous 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.

[0015] The dispersant may be one or more selected from the group consisting of surfactants and phosphate salts.

[0016] The aerogel layer may contain 10% to 90% by weight of the aerogel, 5% to 70% by weight of the fibrous support, and 0.5% to 20% by weight of the functional substance, relative to the total amount of the aerogel layer.

[0017] The inorganic binder may be one or more selected from the group consisting of aluminate, silicate, phosphate, sulfate, and chloride.

[0018] The inorganic binder may be one or more selected from the group consisting of general calcium aluminate, pure calcium aluminate, sodium silicate, potassium silicate, lithium silicate, sodium phosphate, potassium phosphate, magnesium phosphate, zinc phosphate, calcium phosphate, aluminum phosphate, iron phosphate, sodium dihydrogen phosphate, sodium tripolyphosphate, sodium hexametaphosphate, magnesium sulfate, aluminum sulfate, iron(III) sulfate, magnesium chloride, iron(III) chloride, and polyaluminum chloride.

[0019] The fire-resistant layer may be formed on the upper surface, the upper and lower surfaces, or the entire side surface of the heat-insulating sheet.

[0020] The fire-resistant layer may have a thickness of 120% to 400% of the thickness of the fire-resistant layer formed on the upper side of the heat-insulating sheet compared to the thickness of the fire-resistant layer formed on the lower side.

[0021] The battery module includes empty space other than the space in which the cells and the heat insulating sheet are arranged, and the fire-resistant layer is formed in the empty space formed on top of the battery module so as to cover part or all of the side surface of the heat insulating sheet and the side surfaces of the adjacent cells on both sides, and the fire-resistant layer may be formed with a thickness in the center greater than the thickness of the edges on both sides.

[0022] Another embodiment includes the steps of arranging a plurality of cells, arranging the upper and lower surfaces of a heat insulation sheet between the plurality of cells so that they face adjacent cells respectively, and forming a refractory layer on any one or more surfaces of the edge side surfaces between the upper and lower surfaces of the heat insulation sheet, and the refractory layer includes an inorganic binder, and provides a method for manufacturing a battery module.

[0023] The step of forming the refractory layer may be performed before or after arranging the heat insulation sheet between the plurality of cells.

[0024] The step of forming the refractory layer can be performed by any one or more methods of gap coating, dip coating, slot die coating, blade coating, dispensing, printing, brush coating, and potting using an inorganic binder solution dispersed in a solvent.

[0025] Still another embodiment provides a battery pack including the battery module.

Advantages of the Invention

[0026] The battery module according to the present invention can suppress the propagation of heat and flame to adjacent cells due to thermal runaway of the cells.

[0027] In addition, the heat insulation sheet provided in the battery module according to the present invention is excellent in compression performance in addition to heat insulation performance, and has mechanical strength and dimensional stability, so it can prevent the dropout of the aerogel layer that may occur from external impacts, and prevent work convenience and contamination of the mechanism.

Brief Description of the Drawings

[0028] [Figure 1] It is a schematic diagram showing the structure of a battery module according to an embodiment. [Figure 2] It is a schematic diagram showing the structure of a battery module according to an embodiment. [Figure 3]This is a schematic diagram showing the structure of a battery module according to one embodiment. [Figure 4] This is a schematic diagram showing the structure of a battery module according to one embodiment. [Figure 5] This is a schematic diagram showing the structure of a battery module according to one embodiment. [Figure 6] This is a schematic diagram showing the cross-sectional structure of a thermal insulation sheet according to one embodiment. [Figure 7] This is a photograph showing the results of a fire resistance evaluation experiment. [Figure 8] This graph shows the results of the thermal runaway delay evaluation. [Modes for carrying out the invention]

[0029] The embodiments are described below in detail so that they can be easily implemented by a person with ordinary skill in the art. However, the embodiments may be realized in various different forms and are not limited to those described herein.

[0030] A battery module according to one embodiment includes a plurality of cells, an insulating sheet provided between each of the plurality of cells, with its upper and lower surfaces facing the adjacent cell, and a fire-resistant layer formed on one or more of the edge surfaces between the upper and lower surfaces of the insulating sheet, wherein the fire-resistant layer may include an inorganic binder.

[0031] In a battery module according to one embodiment, the fire-resistant layer may be formed on one or more of the edge surfaces of the heat-insulating sheet, selected from the upper surface, lower surface, front surface, and rear surface. Specifically, the fire-resistant layer may be formed on the upper surface, upper and lower surfaces, or the entire side surface of the edge surface of the heat-insulating sheet. More specifically, the fire-resistant layer may be required to be formed on the upper surface of the edge surface of the heat-insulating sheet.

[0032] In a battery module according to one embodiment, the fire-resistant layer may be formed by coating a portion or all of the portion of the surface of the heat-insulating sheet that does not face the cells and is exposed to the outside.

[0033] In a battery module according to one embodiment, the fire-resistant layer may be formed by further coating a part or all of the cells adjacent to the heat-insulating sheet.

[0034] In addition to excellent heat insulation, the battery module having the above structure also possesses fire resistance and flame retardancy or non-combustibility, and can suppress the propagation of heat and flames to adjacent cells due to thermal runaway of cells. In particular, conventionally, when an insulating sheet is provided between cells for insulation, the edges of the insulating sheet are exposed to the air, and heat or flames may be transmitted to the exposed edges during thermal runaway. However, the battery module according to one embodiment can effectively suppress this by providing a fire-resistant layer. Furthermore, the insulating sheet has excellent compression performance, ensures mechanical strength and dimensional stability, prevents the aerogel layer from falling off due to external impact, and improves work convenience and prevents contamination of the mechanism.

[0035] 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 respectively, are arranged with a separator membrane in between, and are sealed in a battery case together with an electrolyte to constitute a secondary battery cell. Depending on the shape of the battery case, they may be classified as cylindrical, rectangular, or pouch type, and a plurality of secondary battery cells are connected in series or parallel to constitute a battery module.

[0036] Such secondary batteries require high stability, but if they are overcharged, for example, decomposition reactions of the positive electrode active material or electrolyte and other side reactions will proceed, and as heat is released through these reactions, it can eventually lead to the explosion of the secondary battery cell.

[0037] In this regard, the present invention provides excellent heat insulation, fire resistance, and flame retardancy or non-combustibility by placing an insulating sheet between each of the cells and providing a fire-resistant layer on the side surface of the insulating sheet, thereby suppressing the propagation of heat and flames to adjacent cells due to thermal runaway of a cell.

[0038] In this explanation, left / right is based on the drawing. For example, in a rectangular hexahedron, if the left face is considered the first side, then the right face can be considered the second side, which is opposite to the first side.

[0039] Figure 1 is a schematic diagram showing a part of a battery module according to one embodiment, which includes heat insulating sheets placed between a plurality of cells, and in which a fire-resistant layer is formed on the upper side surface of the heat insulating sheets. In this case, it is possible to prevent flames generated in one cell from moving from the upper side surface of the heat insulating sheet into the open space within the battery module, and to effectively prevent flames from spreading to adjacent cells.

[0040] Referring to Figure 1, a battery module 100 according to one embodiment includes a plurality of cells 10, and may include an insulating sheet 20 provided between each of the plurality of cells 10. Here, the insulating sheet 20 may be arranged so that its upper and lower surfaces face the adjacent cells 10, respectively. It may also include a fire-resistant layer 30 formed on the upper surface of the side surface of the insulating sheet 20. This makes it possible to provide a battery module with enhanced safety by blocking the flame in advance when one cell experiences thermal runaway and suppressing the spread of the flame to other cells as much as possible, and furthermore, a secondary battery pack including the secondary battery module can be provided.

[0041] In one embodiment, the fire-resistant layer may be formed on the upper and lower surfaces, or the entire surface, of the side surface of the heat-insulating sheet. Here, the upper and lower surfaces refer to the surfaces formed on the upper and lower parts, respectively, based on the configuration in which the heat-insulating sheet is arranged.

[0042] For example, the fire-resistant layer may be formed on the entire side surface of the heat-insulating sheet. In this case, it is possible to prevent flames generated in one cell from moving through the side surface of the heat-insulating sheet into the empty space within the battery module, and to effectively prevent flames from spreading to adjacent cells.

[0043] As another example, the fire-resistant layer may be formed on both the upper and lower opposing sides of the heat-insulating sheet. In this case, while minimizing the installation of the fire-resistant layer, it is possible to prevent flames generated in one cell from moving through the upper and lower sides of the heat-insulating sheet into the open space within the battery module, thereby more effectively preventing the flames from spreading to adjacent cells.

[0044] Figure 2 is a schematic diagram showing a part of a battery module according to one embodiment, which includes heat insulating sheets arranged between a plurality of cells, and in which a fire-resistant layer is formed on the upper and lower sides of the heat insulating sheets.

[0045] Referring to Figure 2, the battery module 100 may include a plurality of cells 10 and an insulating sheet 20 provided between each of the plurality of cells 10. Here, the insulating sheet 12 may be positioned so that its upper and lower surfaces face the adjacent cells 10. It may also include a fire-resistant layer 30 formed on the upper and lower surfaces of the sides of the insulating sheet 20. This makes it possible to provide a battery module with enhanced safety by blocking the flame in advance when one cell experiences thermal runaway and minimizing the spread of the flame to other cells, and furthermore, to provide a secondary battery pack including the secondary battery module.

[0046] In one embodiment, when the fire-resistant layer is formed on the entire side surface of the heat-insulating sheet, the fire-resistant layers formed on the front and rear surfaces are not shown in the cross-sectional view and are represented as shown in Figure 2, so their illustration has been omitted.

[0047] In one embodiment, the fire-resistant layer may have a thickness of 120% to 400%, 150% to 350%, or 200% to 350% of the thickness of the fire-resistant layer formed on the upper side of the heat-insulating sheet. Specifically, the fire-resistant layer may have a thickness of 1.2 to 4 times, 1.5 to 3.5 times, or 2 to 3.5 times the thickness of the fire-resistant layer formed on the lower side of the heat-insulating sheet. By controlling the thickness ratio of the fire-resistant layers formed on the upper and lower sides of the heat-insulating sheet as described above, it is possible to effectively prevent flames from moving upward and spreading in a single cell during thermal runaway.

[0048] Figure 3 is a schematic diagram showing a part of a battery module according to one embodiment, which includes heat insulating sheets arranged between a plurality of cells, and in which fire-resistant layers are formed on the upper and lower surfaces of the sides of the heat insulating sheets, the thickness of the fire-resistant layer formed on the upper surface is greater than the thickness of the fire-resistant layer formed on the lower surface.

[0049] Referring to Figure 3, the battery module 100 may include a plurality of cells 10 and an insulating sheet 20 provided between each of the plurality of cells 10. Here, the insulating sheet 12 may be positioned so that its upper and lower surfaces face adjacent cells 10. The insulating sheet 20 also includes a fire-resistant layer 30 formed on the upper and lower surfaces of its side, and the thickness of the fire-resistant layer formed on the upper surface may be greater than the thickness of the fire-resistant layer formed on the lower surface. This effectively blocks flames that move upward when one cell experiences thermal runaway, minimizing the spread of flames to other cells, thereby providing a battery module with enhanced safety, and furthermore, a secondary battery pack including the secondary battery module can be provided.

[0050] In one embodiment, the battery module includes empty space other than the space in which the cells and the heat insulating sheet are arranged, and the fire-resistant layer is formed in the empty space formed on top of the battery module so as to cover part or all of the side surface of the heat insulating sheet and the side surfaces of adjacent cells on both sides, and the fire-resistant layer may be formed with a thickness in the center that is greater than the thickness of the edges on both sides. For example, the fire-resistant layer may be formed in the shape of a trapezoid or a dome. Forming the fire-resistant layer with a thickness in the center that is greater than the thickness of the edges on both sides has the effect of blocking flames and heat transmitted from the vent at the center of the cell in the plane direction to adjacent cells during thermal runaway of the cell by shielding the heat and flames of the fire-resistant layer in the center, thereby delaying or preventing further thermal runaway.

[0051] Figure 4 is a schematic diagram showing a part of a battery module that includes insulating sheets placed between multiple cells, and in which a fire-resistant layer is formed on the upper side of the insulating sheet, with the fire-resistant layer forming a trapezoidal shape.

[0052] Referring to Figure 4, a battery module 100 according to one embodiment includes a plurality of cells 10, and may include a heat insulating sheet 20 provided between each of the plurality of cells 10. Here, the heat insulating sheet 12 may be arranged so that its upper and lower surfaces face adjacent cells 10. It may also include a fire-resistant layer 30 formed on the upper surface of the side surface of the heat insulating sheet 20, and the fire-resistant layer 30 may be formed in a trapezoidal shape with a thickness in the center greater than the thickness of the edges on both sides. In this case, the fire-resistant layer may also be formed on the lower surface of the side surface of the heat insulating sheet, and the fire-resistant layer formed on the lower surface may be thinner than the fire-resistant layer formed on the upper surface. This makes it possible to provide a battery module with enhanced safety by blocking the flame in advance when one cell experiences thermal runaway and suppressing the propagation of the flame to other cells as much as possible, and furthermore, a secondary battery pack including the secondary battery module can be provided.

[0053] Figure 5 is a schematic diagram showing a part of a battery module that includes insulating sheets placed between multiple cells, and in which a fire-resistant layer is formed on the upper side of the insulating sheet, with the fire-resistant layer forming a dome shape.

[0054] Referring to Figure 5, a battery module 100 according to one embodiment includes a plurality of cells 10, and may include a heat insulating sheet 20 provided between each of the plurality of cells 10. Here, the heat insulating sheet 12 may be arranged so that its upper and lower surfaces face adjacent cells 10. It may also include a fire-resistant layer 30 formed on the upper surface of the side surface of the heat insulating sheet 20, and the fire-resistant layer 30 may be formed in a dome shape with a thickness in the center greater than the thickness of the edges on both sides. In this case, the fire-resistant layer may also be formed on the lower surface of the side surface of the heat insulating sheet, and the fire-resistant layer formed on the lower surface may be thinner than the fire-resistant layer formed on the upper surface. This makes it possible to provide a battery module with enhanced safety by blocking the flame in advance when one cell experiences thermal runaway and suppressing the propagation of the flame to other cells as much as possible, and furthermore, to provide a secondary battery pack including the secondary battery module.

[0055] In one embodiment, the heat insulating sheet may include a first substrate, a second substrate, and an aerogel layer provided between the first and second substrates. Here, the first and second substrates each constitute the upper and lower surfaces of the heat insulating sheet, and may be arranged to face adjacent cells, and may include edge surfaces between the upper and lower surfaces of the heat insulating sheet.

[0056] Figure 6 is a schematic diagram showing the structure of a heat insulating sheet according to one embodiment.

[0057] Referring to Figure 6, the heat insulating sheet 20 may be formed with a structure including a first substrate 21, a second substrate 22, and an aerogel layer 23 provided between the first substrate 21 and the second substrate 22. Here, the first substrate 21 and the second substrate 22 each form the upper and lower surfaces of the heat insulating sheet 20, and may be arranged to face adjacent cells 10, respectively.

[0058] The first and second substrates can be made from a variety of materials, such as resins, metals, non-metallic inorganic materials, or composites thereof, and are not limited in type. Furthermore, the form of the substrate is not particularly limited, and can be a film, thin film, sheet, etc.

[0059] The resin may be, for example, one or more selected from the group consisting of polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and polyamide.

[0060] The aforementioned metal may be one or more selected from the group consisting of, for example, copper, nickel, cobalt, iron, chromium, vanadium, palladium, ruthenium, rhodium, molybdenium, tungsten, iridium, silver, gold, and platinum. When using a substrate made of the aforementioned metal material, the substrate may be subjected to corrosion prevention treatment, insulation treatment, etc., as necessary.

[0061] The inorganic material may be one or more selected from the group consisting of calcium carbonate (CaCO3), talc, and mica.

[0062] As a specific example, the first and second substrates may contain inorganic materials, and as a more specific example, they may contain mica. In this case, the thermal insulation properties and durability of the thermal insulation sheet can be improved.

[0063] The aerogel layer may include an aerogel, a fibrous support, and a functional substance comprising a binder, a dispersant, or a combination thereof.

[0064] In one embodiment, the aerogel has a BET specific surface area of ​​500 m². 2 / g~1,000m 2 It may be / g. For example, the aerogel has a BET specific surface area of ​​500m². 2 / g~950m 2 / g, 550m 2 / g~950m 2 / g, or 600 m 2 / g to 900 m 2

[0065]

[0066]

[0067]

[0068]

[0069]

[0070] It may be / g. By including an aerogel having a BET specific surface area value within the above range, a heat insulation sheet can be provided that effectively prevents heat transfer and heat propagation between a plurality of cells. The average particle size (D50) of the aerogel may be 5 μm to 200 μm, 10 μm to 100 μm, or 20 μm to 50 μm. By including an aerogel having a particle size within the above range, the heat insulation properties can be improved and heat transfer between a plurality of cells can be delayed. The average particle size (D50) can be measured, for example, using the laser diffraction method or a scanning electron microscope (SEM) photograph, and the average particle size (D50) of the particles can be defined as the particle size at the 50% reference of the particle size distribution (the particle size corresponding to 50% volume accumulation of the particle size distribution). The content of the aerogel may be 10% by weight to 90% by weight, 30% by weight to 70% by weight, or 40% by weight to 60% by weight based on the total amount of the aerogel layer. When manufacturing a battery heat insulation sheet containing an aerogel within the above range, the heat insulation performance can be improved. In one embodiment, by including the fibrous support in the aerogel layer, the durability of the heat insulation sheet formed using the same can be improved. The fibrous support may include fibers that are used as supports for ordinary heat insulation materials. For example, the fibrous support may be one or more selected from the group consisting of natural fibers, silica fibers, glass fibers, ceramic fibers, carbon fibers, graphite fibers, mineral fibers, and polymer fibers. As a specific example, the fibrous support may include glass fibers, but is not limited thereto.The aforementioned natural fiber may be one or more selected from the group consisting of, for example, hemp, jute, flax, coir, hemp, and cellulose.

[0071] The ceramic fiber may be one or more selected from the group consisting of silicon carbide, silicon nitride, boron nitride, and aluminum silicon carbide.

[0072] The mineral fiber may be, for example, a mineral fiber containing one or more selected from the group consisting of basalt, wollastonite, alumina, boron, quartz, silica, slag, and rock.

[0073] The polymer fiber may be one or more selected from the group consisting of, for example, nylon, polyimide, polyamide, polybenzimidazole, polybenzoxazole, polyamideimide, polyethylene terephthalate, polybutylene terephthalate, polyester, polyethylene (PE), and polypropylene (PP). Specifically, the polymer fiber may be one or more selected from the group consisting of polyimide, polyamide, and polybenzimidazole, but is not limited thereto.

[0074] The fibrous support may be one or more selected from the group consisting of, for example, powder, wool, chop, felt, batting, and lofty batting, but is not limited thereto.

[0075] The average 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. Including a fibrous support having an average diameter within the above range can make the structure of the aerogel layer more rigid and reduce manufacturing costs.

[0076] The average length of the fibrous support may be, for example, 50 μm to 1000 μm, 70 μm to 800 μm, or 100 μm to 600 μm. By including a fibrous support having an average length within the above range, the aerogel layer can be formed firmly and its durability can be improved.

[0077] The content of the fibrous support may be 5% to 70% by weight, 25% to 60% by weight, or 30% to 50% by weight relative to the total amount of the aerogel layer. When an aerogel layer containing the fibrous support is formed within these ranges to manufacture an insulating sheet, durability may be improved.

[0078] In one embodiment, the binder may include an aqueous polymer binder. For example, the aqueous 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.

[0079] The aqueous polymer may be, but is not limited to, one or more selected from the group consisting of polyvinyl alcohol, polyethylene oxide, polyacrylamide, and polyvinylpyrrolidone.

[0080] The anionic water-soluble polymer may be one or more selected from the group consisting of polymers having functional groups of carboxylic acids, sulfonic acids, sulfate esters, phosphate esters, and their salts. For example, the anionic water-soluble polymer may be a polymer having a carboxylic acid group, and a specific example may include, but is not limited to, polymaleic acid.

[0081] The cationic water-soluble polymer may be one or more selected from the group consisting of polymers having functional groups of amines, ammonium, phosphonium, sulfonium, and their salts. For example, the cationic water-soluble polymer may be a polymer having an amine group, and as a specific example, it may be one or more selected from the group consisting of polyethyleneamine and polyamine, but is not limited thereto.

[0082] The water-dispersible polymer may be one or more selected from the group consisting of water-dispersible polyurethane and water-dispersible polyester, but is not limited thereto.

[0083] The binder may include aqueous polymers and water-dispersible polymers. For example, it may include aqueous polymers having both binder properties and dispersion properties, and water-dispersible polyurethanes having fire-resistant properties. Specific examples include polyvinyl alcohol and water-dispersible polyurethanes.

[0084] The weight ratio of the aqueous polymer and the water-dispersible polymer may be 1:1 to 1:5, 1:1 to 1:4, or 1:2 to 1:3. By using the aqueous polymer and the water-dispersible polymer together within the above weight ratio range, the heat insulation, dust resistance, compression characteristics, fire resistance, and mechanical properties of the heat insulation sheet can be further improved.

[0085] The binder content may be 0.5% to 20% by weight, 2% to 15% by weight, or 8% to 15% by weight relative to the total amount of the aerogel layer. When a battery insulation sheet is manufactured using an aerogel composition containing a binder within the above range, the dust properties of the battery insulation sheet may be improved.

[0086] The binder content may be 0.5% to 20% by weight, 2% to 15% by weight, or 8% to 15% by weight relative to the total amount of the aerogel layer. A heat insulating sheet containing an aerogel layer containing a binder within these ranges may have improved dust-free properties.

[0087] In one embodiment, the dispersant may be one or more selected from the group consisting of surfactants and phosphate salts. Specifically, the dispersant may include, but is not limited to, one or more nonionic surfactants, anionic surfactants, amphoteric surfactants, natural surfactants such as lecithin, and phosphates.

[0088] If the aforementioned dispersant is further included, the fibrous support and aerogel may exist in a more uniformly dispersed form within the aerogel layer.

[0089] The content of the dispersant may be 0.1% to 6% by weight, 0.1% to 5% by weight, or 0.1% to 3% by weight relative to the total amount of the aerogel layer. By including the dispersant within the above range, a battery insulation sheet with excellent heat insulation, compression properties, and dust properties can be manufactured.

[0090] The binder and the dispersant may be present in weight ratios 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 dispersant are used together in weight ratios within these ranges, the aerogel may exist in a more uniformly dispersed form within the aerogel layer.

[0091] In one embodiment, the fibrous support may be present in an amount of 5% to 70% by weight, the aerogel in an amount of 10% to 90% by weight, and the functional substance in an amount of 0.5% to 20% by weight, relative to the total amount of the aerogel layer.

[0092] As an example, the aerogel layer may contain, with respect to the total amount of the aerogel layer, 25% to 60% by weight of the fibrous support, 30% to 70% by weight of the aerogel, and 2% to 15% by weight of the binder.

[0093] Specifically, the aerogel layer may contain, with respect to the total amount of the aerogel layer, 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. Constructing the aerogel layer within these ranges allows for excellent heat insulation while simultaneously improving durability, enhancing the bonding strength between the fibrous support and the aerogel, and preventing dust generation.

[0094] As another example, the aerogel layer may contain, with respect to the total amount of the aerogel layer, 25% to 60% by weight of the fibrous support, 30% to 70% by weight of the aerogel, 2% to 15% by weight of the binder, and 0.1% to 5% by weight of the dispersant.

[0095] Specifically, the aerogel layer may contain, with respect to the total amount of the aerogel layer, 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 3% by weight of the dispersant. Constructing the aerogel layer within these ranges improves the dispersibility of the aerogel, realizes excellent heat insulation properties, improves durability, enhances the bonding strength between the fibrous support and the aerogel, and prevents the generation of dust.

[0096] The aerogel layer may have a configuration in which the surface of the fibrous support is coated with aerogel. In this case, the aerogel and the fibrous support are uniformly distributed, and the bonding strength between the aerogel and the fibrous support is high, which can reduce the generation of dust due to aerogel detachment.

[0097] In one embodiment, the aerogel layer may be formed as a single layer or a multi-layer structure. When the aerogel layer is formed as a multi-layer structure, the aerogel layer may be formed as 2 to 10 layers, 2 to 7 layers, or 2 to 5 layers.

[0098] In one embodiment, the fire-resistant layer may contain an inorganic binder or be composed of an inorganic binder.

[0099] The inorganic binder may be one or more selected from the group consisting of aluminate, silicate, phosphate, sulfate, and chloride.

[0100] The aluminate may be one or more selected from the group consisting of general calcium aluminate and pure calcium aluminate.

[0101] The silicate may be one or more selected from the group consisting of sodium silicate, potassium silicate, and lithium silicate.

[0102] The phosphate may be one or more selected from the group consisting of sodium phosphate, potassium phosphate, magnesium phosphate, zinc phosphate, calcium phosphate, aluminum phosphate, iron phosphate, sodium dihydrogen phosphate, sodium tripolyphosphate, and sodium hexametaphosphate.

[0103] The sulfate may be one or more selected from the group consisting of magnesium sulfate, aluminum sulfate, and iron(III) sulfate.

[0104] The chloride may be one or more selected from the group consisting of magnesium chloride, iron(III) chloride, and polyaluminum chloride.

[0105] As a specific example, the inorganic binder may be one or more selected from the group consisting of calcium aluminate, sodium silicate, and aluminum phosphate. By including the inorganic binder, the fire resistance of the heat insulating sheet can be improved and flame propagation between cells can be prevented.

[0106] A method for manufacturing a battery module according to one embodiment may include the steps of: arranging a plurality of cells; arranging a heat insulating sheet between the plurality of cells such that the upper and lower surfaces of the sheet face adjacent cells; and forming a fire-resistant layer on one or more of the edge surfaces between the upper and lower surfaces of the heat insulating sheet.

[0107] In one embodiment, the arrangement of the multiple cells is not particularly limited and can be appropriately arranged depending on the type of battery.

[0108] In one embodiment, an insulating sheet can be placed between each of the plurality of cells. The insulating sheet may be positioned so that its upper and lower surfaces face the adjacent cells, respectively.

[0109] The heat insulating sheet may include the steps of forming a first substrate, applying an aerogel composition onto the first substrate, and forming a second substrate on the applied aerogel composition.

[0110] The specific details of the first and second substrates can be described above, and their size and shape can be appropriately adjusted and formed by the cell structure.

[0111] The steps for preparing the aerogel composition may include: a step of mixing a functional substance containing a binder, a dispersant, or a combination thereof with a solvent to produce a solvent mixture; a step of mixing the solvent mixture and aerogel to produce an aerogel mixture; and a step of mixing the aerogel mixture and a fibrous support to produce an aerogel composition.

[0112] In the step of preparing a solvent mixture by mixing a functional substance with the aforementioned solvent, either a binder can be mixed with the solvent, or a binder and a dispersant can be mixed with the solvent. In one embodiment, the solvent may be one or more selected from the group consisting of polar solvents and nonpolar solvents. The polar solvent may include water, an alcohol-based solvent, or a combination thereof.

[0113] The water may include, for example, purified water, ultrapure water, or a combination thereof.

[0114] The alcohol-based solvent may be, but is not limited to, one or more selected from the group consisting of methanol, ethanol, propanol, pentanol, butanol, hexanol, ethylene glycol, propylene glycol, diethylene glycol, and glycerol.

[0115] The nonpolar solvent may include a hydrocarbon solvent. For example, the hydrocarbon solvent may be one or more selected from the group consisting of hexane, pentane, heptane, toluene, and benzene, and is more preferably an alkane solvent such as hexane, or a mixture containing an alkane solvent, but is not limited thereto.

[0116] The solvent may include water. Using water as the solvent can effectively reduce raw material costs and post-processing costs. However, when water is used as the solvent, there is a problem in that mixing with hydrophobic aerogel is not easy. In one embodiment, the aerogel is uniformly dispersed by controlling the mixing stage design, mixing conditions, and the addition and amount of binder and dispersant. By uniformly dispersing the aerogel in the composition in this way, a battery insulation sheet with excellent heat insulation, durability, and low dust characteristics can be formed at a thin thickness without using a large amount of binder.

[0117] The solvent may be included in such a weight ratio to the total solid content of the aerogel composition that 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 this range, the viscosity can be controlled to coat the aerogel layer.

[0118] The specific details regarding the binder and dispersant can be provided as described above.

[0119] In the step of mixing the aforementioned solvent mixture and aerogel to produce an aerogel mixture, the specific description of the aerogel can be as described above.

[0120] In the step of mixing the aerogel mixture and the fibrous support to produce the aerogel composition, a specific explanation of the fibrous support can be given as described above.

[0121] In one embodiment, the aerogel composition may further contain a silane compound. The silane compound may be one or more selected from the group consisting of, for example, 3-(trimethoxysilyl)propyl methacrylate, methyltriethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, octadecyltrimethoxysilane, ethyltriethoxysilane, and 3-glycidoxypropyltrimethoxysilane. The inclusion of the silane compound further improves dispersibility.

[0122] In one embodiment, the aerogel composition may further selectively contain additives such as wetting agents, emulsifiers, compatibilizers, viscosity modifiers, pH modifiers, stabilizers, antioxidants, acidic or basic scavenging agents, metal deactivators, defoamers, antistatic agents, thickeners, adhesion improvers, binders, flame retardants, impact modifiers, pigments, dyes, colorants, and deodorants.

[0123] In each of the steps of preparing a solvent mixture by mixing a functional substance containing a binder, a dispersant, or a combination thereof with the solvent, preparing an aerogel mixture by mixing the solvent mixture with aerogel powder, and preparing an aerogel composition by mixing the aerogel mixture with a fibrous support, a mixer can be used during mixing. For example, the mixer may include, but is not limited to, a planetary mixer and a thinky mixer.

[0124] As a specific example, a planetary mixer can be used when mixing the solvent mixture and the aerogel powder. When the solvent mixture and the aerogel powder are mixed using the planetary mixer, the aerogel powder can be uniformly dispersed in the solvent.

[0125] The planetary mixer may be equipment that can be used to mix or stir different substances together to produce a homogeneous mixture. It may include blades capable of planetary motion.

[0126] In one embodiment, the planetary mixer may include one or more planetary blades and one or more high-speed dispersion blades. Specifically, the planetary mixer may include one or more planetary blades and one or more high-speed dispersion blades.

[0127] The planetary blades and high-speed dispersion blades rotate continuously around their respective axes. The rotational speed may be expressed in units of rotations per minute (rpm).

[0128] In one embodiment, the planetary mixer may include a first blade and a second blade having different axes of rotation. 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 rotational speeds of the first blade and the second blade. Specifically, the first blade may be an open blade and the second blade may be a despa blade.

[0129] The rotational 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. The rotational 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.

[0130] When adding a functional substance to the solvent and mixing, the rotation speed of the first blade 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, 600 rpm to 1000 rpm, or 700 rpm to 800 rpm. Mixing the solvent and the functional substance as described above produces a solvent mixture in which the binder, dispersant, or a combination thereof is uniformly dispersed, making aerogel mixing easier in subsequent steps.

[0131] 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. When the aerogel powder is added to the solvent mixture and mixed as described above, it is possible to prevent the aerogel powder from agglomerating with each other and induce a uniform dispersion.

[0132] 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. When the aerogel mixture and the fibrous support are mixed in this way, air bubbles in the composition are removed, the viscosity is adjusted, and the fibrous support is easily dispersed among the uniformly dispersed aerogel, so that the fibrous support may exist in the composition in a form in which the aerogel covers the periphery. Here, a binder is present between the aerogel and the fibrous support, which can improve the binding force between the aerogel and the fibrous support.

[0133] By forming the heat insulating sheet using the method according to one embodiment, not only is the heat insulating property improved, but the durability is also improved, and it is possible to prevent the aerogel from falling off and generating dust when the heat insulating sheet is manufactured, installed inside the device, or when external vibrations occur.

[0134] In one embodiment, the step of forming a fire-resistant layer on one or more of the edge surfaces between the upper and lower surfaces of the heat-insulating sheet may be performed before or after placing the heat-insulating sheet between the plurality of cells.

[0135] For example, the step of forming the fire-resistant layer may be performed before placing the heat-insulating sheet between the multiple cells. In this case, after manufacturing the heat-insulating sheet, the fire-resistant layer can be formed on one or more of the sides of the heat-insulating sheet, and the heat-insulating sheets with the fire-resistant layer can be placed between the multiple cells.

[0136] The fire-resistant layer may be formed by a coating process of an inorganic binder solution dispersed in a solvent, such as gap coating, dip coating, slot die coating, blade coating, dispensing, printing, brush coating, or porting using molding. Specifically, a fire-resistant layer can be formed by coating one or more sides of the heat-insulating sheet with an inorganic binder in a solution dispersed in a solvent, and drying it at room temperature or at a temperature of 40°C to 80°C within 24 hours.

[0137] As another example, the step of forming the fire-resistant layer may be performed after placing the heat-insulating sheet between the plurality of cells. In this case, a heat-insulating sheet can be placed between each of the plurality of cells, and the fire-resistant layer can be formed on one or more of the sides of the heat-insulating sheet.

[0138] The fire-resistant layer may be formed by solution processes such as gap coating, dispensing, printing, brush coating, and porting. Specifically, a solution-type inorganic binder dispersed in a solvent can be injected into one or more sides of the insulation sheet from the side of the insulation sheet exposed inside the battery module in which the plurality of cells and the insulation sheet are arranged, and dried at room temperature or at a temperature of 40°C to 80°C within 24 hours to form a fire-resistant layer.

[0139] One embodiment includes a battery pack containing the battery modules. Multiple battery modules may be arranged inside the battery pack.

[0140] The following describes specific embodiments of the present invention. However, the embodiments described below are merely for illustrative purposes or to illustrate the present invention, and the present invention should not be limited to them. Furthermore, any matters not described herein can be sufficiently inferred by technical means by those skilled in the art, and therefore their explanations are omitted.

[0141] (Battery module manufacturing) Example 1 1. Manufacturing of thermal insulation sheets After adding polyvinyl alcohol (Sigma Aldrich, Poly(vinyl alcohol)) as a binder to ultrapure water as the solvent, the mixture was prepared by mixing under the conditions of an open blade at 30 rpm and a despa blade at 700 rpm. Subsequently, a BET value of 800 m was added to the solvent mixture. 2 After adding aerogel powder at a concentration of / g, the mixture was prepared by mixing at 70 rpm with the open blade and 1500 rpm with the despa blade. After adding glass wool to the aerogel mixture, the mixture was prepared by mixing at 30 rpm with the open blade and 1200 rpm with the despa blade. A planetary mixer (DN Tech, PT-005) was used for mixing.

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

[0143] The manufactured aerogel composition was slurry-coated onto a 0.1 mm thick mica sheet (Famica, Muscovite), then another 0.1 mm thick mica sheet was laminated in a sandwich-type manner and coated using a roll-rolling method. Afterward, it was dried at 60°C for 24 hours to form an aerogel layer, thereby producing a battery insulation sheet. The total thickness of the manufactured battery insulation sheet was confirmed to be 1.38 mm.

[0144] 2. Fireproof layer manufacturing A fire-resistant layer was formed on the upper side of the aforementioned heat-insulating sheet using a dispensing printing method with calcium silicate as an inorganic binder. At this time, the thickness of the fire-resistant layer was confirmed to be 0.3 mm.

[0145] 3. Battery module manufacturing Multiple cells are arranged within the battery module, and an insulating sheet with a fire-resistant layer is placed between each of the multiple cells.

[0146] Example 2 The same method as in Example 1 was used, except that calcium aluminate was used instead of calcium silicate as the inorganic binder in Example 1.

[0147] Example 3 The same method as in Example 1 was used, except that aluminum phosphate was used instead of calcium silicate as the inorganic binder in Example 1.

[0148] Example 4 The refractory layer was manufactured in the same manner as in Example 1, except that a brush coating method was used instead of a dispensing printing method during the manufacturing of the refractory layer.

[0149] Example 5 The same method as in Example 1 was used for manufacturing, except that a fire-resistant layer was formed on the upper and lower sides of the heat-insulating sheet.

[0150] Example 6 The same method as in Example 1 was used, except that a fire-resistant layer was formed on the entire side surface of the heat-insulating sheet.

[0151] Example 7 In Example 1, a fire-resistant layer was formed on the upper and lower sides of the heat-insulating sheet. The only difference was that the thickness of the fire-resistant layer formed on the upper side was adjusted to 0.7 mm, and the thickness of the fire-resistant layer formed on the lower side was adjusted to 0.3 mm. Otherwise, it was manufactured using the same method as in Example 1.

[0152] Example 8 1. Manufacturing of thermal insulation sheets After adding polyvinyl alcohol (Sigma Aldrich, Poly(vinyl alcohol)) as a binder to ultrapure water as the solvent, the mixture was prepared by mixing under the conditions of an open blade at 30 rpm and a despa blade at 700 rpm. Subsequently, a BET value of 800 m was added to the solvent mixture. 2After adding aerogel powder at a concentration of / g, the mixture was prepared by mixing at 70 rpm with the open blade and 1500 rpm with the despa blade. After adding glass wool to the aerogel mixture, the mixture was prepared by mixing at 30 rpm with the open blade and 1200 rpm with the despa blade. A planetary mixer (DN Tech, PT-005) was used for mixing.

[0153] The solid content of the manufactured aerogel composition was confirmed to be 50% by weight of aerogel, 40% by weight of glass wool, and 10% by weight of polyvinyl alcohol.

[0154] The manufactured aerogel composition was slurry-coated onto a 0.1 mm thick mica sheet (Famica, Muscovite), then another 0.1 mm thick mica sheet was laminated in a sandwich-type manner and coated using a roll-rolling method. Afterward, it was dried at 60°C for 24 hours to form an aerogel layer, thereby manufacturing a battery insulation sheet. The total thickness of the manufactured battery insulation sheet was confirmed to be 1.38 mm.

[0155] 2. Battery module manufacturing Multiple cells were arranged within the battery module, and an insulating sheet was placed between each of the multiple cells.

[0156] 3.Refractory layer manufacturing A trapezoidal open molding was attached to the upper surface of the insulating sheet placed between each of the aforementioned cells, covering a portion of the side surface of the adjacent cell. A refractory layer was then formed by injecting calcium silicate in solution as an inorganic binder and drying the mixture. At this time, the thickness of the center of the refractory layer was confirmed to be 0.7 mm, and the thickness of the edges on both sides was confirmed to be 0.5 mm.

[0157] Comparative Example 1 1. Manufacturing of aerogel composition An aerogel composition was prepared by adding polyvinyl alcohol (Sigma Aldrich, Poly(vinyl alcohol)) as a binder and aerogel with a BET value of 800 m2 / g to ultrapure water as a solvent and mixing. A planetary mixer (DN Tech, PT-005) was used for mixing.

[0158] The solid content of the manufactured aerogel composition was confirmed to be 50% by weight of aerogel, 40% by weight of glass wool, and 10% by weight of polyvinyl alcohol.

[0159] 2. Manufacturing of battery insulation sheets The manufactured aerogel composition was slurry-coated onto a 0.1 mm thick mica sheet (Famica, Muscovite), then another 0.1 mm thick mica sheet was laminated in a sandwich-type manner and coated using a roll-rolling method. Afterward, it was dried at 60°C for 24 hours to form an aerogel layer, thereby manufacturing a battery insulation sheet. The total thickness of the manufactured battery insulation sheet was confirmed to be 1.38 mm.

[0160] (Example of experiment) Experimental Example 1: Fire Resistance Evaluation The fire resistance was evaluated using the heat-insulating sheets manufactured in Examples 1-8 and Comparative Example 1 described above.

[0161] Specifically, using a gas ignition torch device, the sheets were irradiated for 10 minutes in the direction of the surface where the refractory layer was formed, under conditions of an irradiation temperature of 1100±10℃ and an irradiation distance of 5cm or less from the flame. After observing changes such as the collapse of the refractory layer and internal structure, a 20×60mm sample was taken from the side of the insulation sheet, and the toughness, which indicates the energy stored until the sheet's final failure / breakdown, was measured using a 3-point bending test with a Universal Test Machine (UTM). The toughness measurements for each insulation sheet were then evaluated, and the toughness values ​​are shown in Table 1 below. In addition, photographs of Examples 1, 4, and 8 and Comparative Example 1 after flame irradiation can be seen in Figure 7.

[0162] [Table 1]

[0163] Referring to Table 1, the toughness measurement results, which represent the mechanical durability after flame irradiation, can be confirmed from Examples 1 to 3 depending on the type of inorganic binder. This confirms that calcium silicate, calcium aluminate, and aluminum phosphate all exhibit excellent fire resistance when used as inorganic binders.

[0164] Furthermore, from Examples 1 and 4, the results of fire resistance evaluation using the fire-resistant layer formation method were confirmed, and it was confirmed that the dispensing printing method forms a more uniform and dense fire-resistant layer and exhibits superior fire resistance compared to the brush coating method.

[0165] Furthermore, from Example 5, it was confirmed that toughness is further improved when the fire-resistant layer is formed on the upper and lower surfaces of the side surface of the heat-insulating sheet. In Example 6, the fire-resistant layer is formed on the entire side surface of the heat-insulating sheet, and toughness is improved to some extent, but the degree of improvement is small and the efficiency is low. Furthermore, from Example 7, it was confirmed that when the fire-resistant layer is formed on the upper and lower surfaces of the side surface of the heat-insulating sheet, increasing the thickness of the fire-resistant layer formed on the upper surface further improves toughness.

[0166] Furthermore, from Example 8, it was confirmed that even when the fire-resistant layer is formed on the upper and lower sides of the heat-insulating sheet, the toughness is effectively improved when it is formed in a trapezoidal shape so as to cover the upper side of the heat-insulating sheet and a portion of the side of the adjacent cell.

[0167] On the other hand, in Comparative Example 1, which did not contain a fire-resistant layer, it was confirmed that the fire resistance was significantly reduced.

[0168] Furthermore, Figure 7 shows internal photographs of the battery insulation sheets after fire resistance testing for Examples 1-4, 8, and Comparative Example 1. As can be seen in Figure 7, the internal structure revealed that the fire resistance of the side surfaces of the insulation sheets was excellent in the examples due to the formation of a fire-resistant layer.

[0169] Specifically, in Comparative Example 1, it was confirmed that the fire resistance and structural fragility of the side surface of the insulation sheet were very poor. In contrast, in Examples 1, 4, and 8, it was confirmed that they had excellent fire resistance and did not burn, as well as excellent structural stability and insulation properties.

[0170] Experimental Example 2: Thermal Runaway Delay Evaluation Thermal runaway delay evaluation was performed using the thermal insulation sheets manufactured in Examples 1-8 and Comparative Example 1 described above.

[0171] Specifically, using a simple modular device consisting of three rectangular cells, a thermal runaway test was performed on each insulation sheet by artificially inducing thermal runaway by heating a heating wire pad attached to the detonating cell (heating rate of 20°C / min) under a fastening pressure of 15kN for the insulation sheets between the cells. The thermal runaway delay time (s) was measured and is shown in Table 2 below. Furthermore, the temperature changes over time for Examples 1 and 4 and Comparative Example 1 are shown in Figure 8.

[0172] [Table 2]

[0173] Referring to Table 2, the thermal runaway delay evaluation results for each type of inorganic binder can be confirmed from Examples 1 to 3. This confirms that calcium silicate, calcium aluminate, and aluminum phosphate all exhibit excellent thermal runaway delay effects when used as inorganic binders.

[0174] Furthermore, from Examples 1 and 4, the results of evaluating thermal runaway delay based on the method of forming the refractory layer were confirmed, confirming that the thermal runaway delay effect is superior when the refractory layer is formed uniformly and densely by the dispensing method. On the other hand, from Figure 8, it can be confirmed that in Examples 1 and 4, the formation of the refractory layer delays the temperature rise of adjacent cells during thermal runaway, and in Example 1, the temperature rise is further delayed during thermal runaway.

[0175] Furthermore, from Examples 1, 5-8, the results of evaluating thermal runaway delay based on the position and form of the fire-resistant layer were confirmed. This confirmed that a better thermal runaway delay effect is observed when the fire-resistant layer is formed on the upper and lower edges of the insulation sheet, when it is formed on the entire side surface, or when it is formed on the upper and lower edges, with the thickness of the fire-resistant layer formed on the upper surface being relatively thick. In addition, it was confirmed that even when the fire-resistant layer is formed on the upper and lower edges of the insulation sheet, effective thermal runaway delay is possible when it is formed in a trapezoidal shape covering the upper surface and a portion of the side surface of an adjacent cell.

[0176] On the other hand, in Comparative Example 1, since no reinforcing material is included, it is difficult to delay thermal runaway during thermal runaway, and as can be seen from Table 2 above and attached Figure 8, the temperature rise of adjacent cells appears immediately.

[0177] Although preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and can be implemented in various ways within the scope of the claims, the detailed description of the invention, and the accompanying drawings, and these variations naturally also fall within the scope of the present invention. [Explanation of Symbols]

[0178] 10 cells 20 Insulation Sheets 21 First base material 22 Second base material 23 Aerogel layer 30 Fireproof layer 100 Battery Modules

Claims

1. Multiple cells and An insulating sheet is provided between each of the aforementioned plurality of cells, with its upper and lower surfaces facing the adjacent cell, A battery module comprising a fire-resistant layer formed on one or more edge surfaces between the upper and lower surfaces of the heat-insulating sheet, The aforementioned heat insulating sheet and the aforementioned fire-resistant layer are composed of different materials. The fire-resistant layer comprises an inorganic binder, The aforementioned heat insulating sheet is First substrate and The second substrate and The material includes an aerogel layer provided between the first substrate and the second substrate, The battery module includes empty space other than the space in which the cells and the heat insulating sheet are arranged. The fire-resistant layer is formed in the open space formed above the battery module so as to cover the entire side surface of the heat-insulating sheet and part or all of the sides of the adjacent cells on both sides. The aforementioned fire-resistant layer is formed such that the thickness of the central part is greater than the thickness of the edges on both sides of the battery module.

2. The battery module according to claim 1, wherein the cell is a secondary battery cell.

3. The battery module according to claim 1, wherein each of the first substrate and the second substrate comprises a resin, a metal, an inorganic material other than a metal, or a composite thereof.

4. The battery module according to claim 1, wherein the aerogel layer comprises an aerogel, a fibrous support, and a functional substance including a binder, a dispersant, or a combination thereof.

5. The aerogel has a BET specific surface area of ​​500 m². 2 / g to 1,000m 2 The battery module according to claim 4, wherein the value is / g.

6. The battery module according to claim 4, wherein the fibrous support is one or more selected from the group consisting of natural fibers, silica fibers, glass fibers, ceramic fibers, carbon fibers, graphite fibers, mineral fibers, and polymer fibers.

7. The binder comprises an aqueous polymer binder. The battery module according to claim 4, wherein the aqueous polymer binder is one or more selected from the group consisting of aqueous polymers, anionic water-soluble polymers, cationic water-soluble polymers, and water-dispersible polymers.

8. The battery module according to claim 4, wherein the dispersant is one or more selected from the group consisting of surfactants and phosphate salts.

9. The battery module according to claim 4, wherein the aerogel layer comprises 10% to 90% by weight of the aerogel, 5% to 70% by weight of the fibrous support, and 0.5% to 20% by weight of the functional substance, relative to the total amount of the aerogel layer.

10. The battery module according to claim 1, wherein the inorganic binder is one or more selected from the group consisting of aluminate, silicate, phosphate, sulfate, and chloride.

11. The battery module according to claim 1, wherein the inorganic binder is one or more selected from the group consisting of general calcium aluminate, pure calcium aluminate, sodium silicate, potassium silicate, lithium silicate, sodium phosphate, potassium phosphate, magnesium phosphate, zinc phosphate, calcium phosphate, aluminum phosphate, iron phosphate, sodium dihydrogen phosphate, sodium tripolyphosphate, sodium hexametaphosphate, magnesium sulfate, aluminum sulfate, iron(III) sulfate, magnesium chloride, iron(III) chloride, and polyaluminum chloride.

12. The battery module according to claim 1, wherein the fire-resistant layer is formed on the upper and lower surfaces, or the entire side surface, of the side surface of the heat-insulating sheet.

13. The battery module according to claim 1, wherein the thickness of the fire-resistant layer formed on the upper side of the heat-insulating sheet is 120% to 400% of the thickness of the fire-resistant layer formed on the lower side.

14. The stage of arranging multiple cells, The step of arranging the thermal insulation sheet between the plurality of cells such that the upper and lower surfaces of the sheet face the adjacent cells, A method for manufacturing a battery module, comprising the step of forming a fire-resistant layer on one or more edge surfaces between the upper and lower surfaces of the heat-insulating sheet, The aforementioned heat insulating sheet and the aforementioned fire-resistant layer are composed of different materials. The fire-resistant layer comprises an inorganic binder, The aforementioned heat insulating sheet is First substrate and The second substrate and The material includes an aerogel layer provided between the first substrate and the second substrate, The battery module includes empty space other than the space in which the cells and the heat insulating sheet are arranged. The fire-resistant layer is formed in the open space formed above the battery module so as to cover the entire side surface of the heat-insulating sheet and part or all of the sides of the adjacent cells on both sides. A method for manufacturing a battery module, wherein the fire-resistant layer is formed with a thickness in the center greater than the thickness of the edges on both sides.

15. The method for manufacturing a battery module according to claim 14, wherein the step of forming the fire-resistant layer is performed before or after placing the heat insulating sheet between the plurality of cells.

16. The method for manufacturing a battery module according to claim 14, wherein the step of forming the fire-resistant layer is performed using one or more of the following methods: gap coating, dip coating, slot die coating, blade coating, dispensing, printing, brush coating, and porting, using an inorganic binder solution dispersed in a solvent.

17. A battery pack comprising a battery module according to any one of claims 1 to 13.

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