Battery heat insulating sheet and manufacturing method thereof

Abstract

To provide a battery insulation sheet and a manufacturing method for the battery insulation sheet.SOLUTION: A battery insulation sheet includes a substrate, and an aerogel layer on the substrate, wherein the aerogel layer includes: a fibrous support; an aerogel; and a functional material including a binder, a dispersant, or a combination thereof, and satisfies a following formula 1: 50≤A≤100000, A=Ti / Ds, wherein, in the formula 1, Ti denotes a thickness of the aerogel layer, and Ds denotes an average diameter of the fibrous support. Also there is provided a manufacturing method for the battery insulation sheet.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a battery insulating sheet and a method for manufacturing 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. Recently, interest in electric vehicles has increased to prevent environmental pollution, leading to the adoption of high-capacity secondary batteries for electric vehicles. These secondary batteries are required to have characteristics such as high density, high output, and stability.

[0003] In addition, when a battery contains a large number of high-capacity cells such as lithium-ion secondary batteries, there is a risk that one cell may overheat for some reason and go into thermal runaway, adversely affecting other adjacent cells, so it is necessary to thermally insulate adjacent cells from each other.

[0004] For this reason, conventionally, plates or insulating resin plates have been placed between the cells to insulate and heat the adjacent cells.

[0005] The above information disclosed in the Background of the Invention section is intended solely to enhance understanding of the background of the present invention and may therefore 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 insulation sheet having excellent heat insulation, compression properties, and dust resistance, and a manufacturing method thereof. [Means for solving the problem]

[0007] One embodiment provides a battery insulation sheet including a substrate and an aerogel layer formed on the substrate, wherein the aerogel layer includes a fibrous support, an aerogel, and a functional material including a binder, a dispersant, or a combination thereof, and satisfies the following formula 1: [Formula 1] 50≦A≦100000, A=T i / D s In the above formula 1, the above T i is the thickness of the aerogel layer, and D s is the average diameter of the fibrous support.

[0008] The thickness of the aerogel layer may be 1 mm to 10 mm.

[0009] The average diameter of the fibrous support may be 0.1 μm to 20 μm.

[0010] The A may be 200 to 10,000.

[0011] The surface of the fibrous support may be coated with an aerogel.

[0012] The substrate may contain one or more materials selected from the group consisting of resins, metals, and inorganic materials other than metals.

[0013] The fibrous support may comprise one or more fibers selected from the group consisting of natural fibers, silica fibers, glass fibers, carbon fibers, basalt fibers, and polymeric fibers.

[0014] The aerogel has a BET specific surface area of ​​500 m 2 / g~1,000m 2 / g.

[0015] The binder includes a water-based polymer binder, and the water-based polymer binder may include one or more selected from the group consisting of aqueous polymers, anionic water-soluble polymers, cationic water-soluble polymers, and water-dispersible polymers.

[0016] The binder may be contained in an amount of 0.5% by weight to 20% by weight based on the total amount of the aerogel layer.

[0017] The binder may include a water-soluble polymer and a water-dispersible polymer, and the water-soluble polymer and the water-dispersible polymer may be included in a weight ratio of 1:1 to 1:5.

[0018] The dispersant may include one or more selected from the group consisting of surfactants and phosphate-based salts.

[0019] The dispersant may be contained in an amount of 0.1% by weight to 6% by weight based on the total amount of the aerogel layer.

[0020] The binder and the dispersant may be contained in a weight ratio of 1:0.001 to 1:0.67.

[0021] The aerogel layer may contain 5% by weight to 70% by weight of the fibrous support, 10% by weight to 90% by weight of the aerogel, and 0.5% by weight to 20% by weight of the functional material, based on the total weight of the aerogel layer.

[0022] 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, based on the total weight of the aerogel layer.

[0023] The aerogel layer may contain, relative to the total amount of the aerogel layer, 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 5% by weight of the dispersant.

[0024] Another embodiment provides a method for manufacturing a battery insulation sheet, the method comprising: coating an aerogel composition on a substrate; and drying the aerogel composition coated on the substrate to form an aerogel layer, the aerogel layer including a fibrous support; an aerogel; and a functional material including a binder, a dispersant, or a combination thereof, and satisfying the following formula 1: [Formula 1] 50≦A≦100000, A=T i / D s In the above formula 1, the above T i is the thickness of the aerogel layer, and D s is the average diameter of the fibrous support.

[0025] The method for producing the aerogel composition may include the steps of: mixing a functional material, including a binder, a dispersant, or a combination thereof, with a solvent to produce a solvent mixture; mixing the solvent mixture with an aerogel to produce an aerogel mixture; and mixing the aerogel mixture with a fibrous support to produce an aerogel composition.

[0026] The solvent may include one or more selected from the group consisting of polar solvents and non-polar solvents. [Effects of the Invention]

[0027] The battery insulation sheet according to one embodiment includes an aerogel layer in the form of a fibrous support surface coated with aerogel, and has excellent heat insulation and compression properties, low manufacturing costs, and can prevent aerogel dust generation during manufacturing and actual use. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a schematic diagram showing a battery insulation sheet formed between a plurality of cells according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram illustrating the structure of a battery insulation sheet according to an embodiment. [Figure 3]FIG. 3 is a schematic diagram illustrating the structure of a battery insulation sheet according to an embodiment. [Figure 4] FIG. 4 is an SEM image of a cross section of the battery heat insulating sheet of Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0029] 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 many different forms and is not limited to the embodiments set forth herein.

[0030] Insulation is a material used to prevent the movement of heat from high to low places, and is used not only in the construction of refrigerators, cold storage warehouses, and buildings, but also in various industrial fields including the aircraft, electronic parts, and automotive industries.

[0031] Such a heat insulating material must have excellent heat insulating properties through low thermal conductivity, and also must have sufficient mechanical strength to maintain such heat insulating properties.

[0032] Aerogel is a transparent or translucent cutting-edge material with a nanoporous structure. It has very low density and low thermal conductivity, so it has great potential as an insulating material and is considered to be a highly efficient super-insulating material that can be used in a variety of industrial fields.

[0033] The greatest advantage of aerogel is that it has lower thermal conductivity than conventional organic insulation materials such as styrofoam, and it solves the fatal weaknesses of organic insulation materials, such as vulnerability to fire and the generation of harmful gases during a fire.

[0034] However, aerogels generally have very low strength, such as being easily broken even by a small impact due to their high brittleness, and are difficult to process into very thin thicknesses and shapes. Therefore, despite their excellent thermal insulation properties, it is very difficult to manufacture thermal insulation materials using aerogels alone.

[0035] According to one embodiment, a battery insulation sheet includes a substrate and an aerogel layer formed on the substrate. The aerogel layer includes a fibrous support, an aerogel, and a functional material including a binder, a dispersant, or a combination thereof, and may satisfy the following formula 1: [Formula 1] 50≦A≦100000, A=T i / D s In the above formula 1, the above T i is the thickness of the aerogel layer, and D s is the average diameter of the fibrous support.

[0036] The battery insulation sheet formed with this structure has excellent insulation properties and compression characteristics, low manufacturing costs, and can prevent aerogel dust generation during manufacturing and actual use. Furthermore, the aerogel layer has a form in which the surface of the fibrous support is coated with aerogel, and the aerogel and the fibrous support are uniformly distributed, and the bonding strength between the aerogel and the fibrous support is strong, thereby reducing dust generation due to aerogel detachment.

[0037] FIG. 1 is a schematic diagram showing a battery insulation sheet formed between a plurality of cells according to an embodiment. 1, a battery insulation sheet 100 according to an embodiment may be formed between each of the cells 200 in a battery module including the plurality of cells 200. Here, the upper and lower surfaces of the battery insulation sheet may be disposed to face each of the adjacent cells. By forming the battery insulation sheet 100 according to an embodiment between each of the plurality of cells 200, a fire can be blocked in advance within the cell, and the spread of the fire to other cells can be minimized, thereby providing a battery module and a battery pack including the same with improved safety.

[0038] FIG. 2 is a schematic diagram illustrating the structure of a battery insulation sheet according to an embodiment. Referring to FIG. 2, the battery insulation sheet 100 includes a substrate 110 and an aerogel layer 120 formed on the substrate 110, where the upper and lower surfaces of the battery insulation sheet may be arranged to face the adjacent cells, respectively. By forming an aerogel layer using the aerogel composition according to an embodiment on the substrate, the battery insulation sheet has improved heat insulation properties as well as compression characteristics, and can prevent the aerogel from detaching and generating dust when the battery insulation sheet is manufactured or installed inside a device.

[0039] FIG. 3 is a schematic diagram showing the structure of a battery insulation sheet according to another embodiment. 3, in one embodiment, the battery insulation sheet 100 may have a structure including a first substrate 130, an aerogel layer 120 formed on the first substrate 130, and a second substrate 140 formed on the aerogel layer 120. Here, the first substrate and the second substrate may be disposed to face the adjacent cell, respectively. The first substrate and the second substrate may be formed of the same or different materials.

[0040] In the above formula (1), the value of A may be, for example, 50 to 100,000, 100 to 30,000, or 200 to 10,000. By satisfying the value of A within this range, the ratio of the thickness of the aerogel layer to the average diameter of the fibrous support can be controlled, and the aerogel layer structure can be formed with a robust structure. In this case, it becomes easier to withstand excessive pressure during heat transfer between multiple cells. Furthermore, by controlling the ratio of the thickness of the aerogel layer to the average diameter of the fibrous support, the coatability of the aerogel layer is improved, making it easier to install a heat insulating sheet between multiple cells.

[0041] The substrate may be made of various materials, such as resin, metal, inorganic material other than metal, or a composite thereof, and the type of the substrate is not limited. The form of the substrate may be a film, thin film, sheet, or the like, and is not particularly limited.

[0042] The resin may include, for example, one or more selected from the group consisting of polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and polyamide.

[0043] The metal may include, 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 a metal material, the substrate may be subjected to corrosion prevention treatment, insulation treatment, etc., as necessary.

[0044] The inorganic material may include one or more selected from the group consisting of calcium carbonate (CaCO3), talc, and mica.

[0045] As a specific example, the substrate may include an inorganic material, and as a further specific example, it may include mica, which can improve the heat insulating properties and durability of the heat insulating sheet.

[0046] The thickness of the substrate may be 0.01 mm to 5 mm, 0.05 mm to 3 mm, or 0.1 mm to 1 mm. A heat insulating sheet can be formed by forming an aerogel layer on a substrate having a thickness within the above range.

[0047] In the battery insulation sheet, the aerogel layer may include a fibrous support; an aerogel; and a functional material including a binder, a dispersant, or a combination thereof.

[0048] The thickness of the aerogel layer may be 1 mm to 10 mm, 1 mm to 5 mm, or 1 mm to 3 mm. By forming an aerogel layer on a substrate having a thickness within the above range, a heat insulating sheet with excellent heat insulating and compressible properties can be produced.

[0049] In one embodiment, the fibrous support may be included in the aerogel layer, thereby improving the durability of the battery insulation sheet.

[0050] The fibrous support may include fibers commonly used in supports for conventional insulating materials. For example, the fibrous support may include 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 glass fibers, but is not limited thereto.

[0051] The natural fibers may include, for example, one or more selected from the group consisting of hemp, jute, flax, coir, kenaf, and cellulose.

[0052] The mineral fibers may be, for example, mineral fibers containing one or more selected from the group consisting of basalt, wollastonite, alumina, silica, slag, and rock.

[0053] The polymer fiber may include, for example, one or more selected from the group consisting of nylon, polyimide, polyamide, polybenzimidazole, polybenzoxazole, polyamideimide, polyethyleneterephtalate, polybutyleneterephtalate, polyester, polyethylene (PE), and polypropylene (PP). Specific examples of the polymer fiber include, but are not limited to, any one or more of polyimide, polyamide, and polybenzimidazole.

[0054] The fibrous support may be, for example, in the form of wool or chopped strands, but is not limited thereto.

[0055] 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. By including a fibrous support having an average diameter within the above range, the structure of the aerogel layer can be made more robust and production costs can be reduced.

[0056] 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 durability can be improved.

[0057] 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. A battery insulation sheet including an aerogel layer containing a fibrous support within this range can improve durability.

[0058] In one embodiment, 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 within the above range, it is possible to provide a heat insulating sheet that can effectively prevent heat transfer and heat propagation between a plurality of cells.

[0059] 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 aerogel having an average particle size within the above range, the heat insulating properties can be improved and heat transfer between multiple cells can be delayed.

[0060] In this disclosure, when particles are spherical, "particle size" refers to the particle size or average particle size, and when particles are non-spherical, "particle size" refers to the major axis length or average major axis length. Particle size (or size) can be measured using a scanning electron microscope or a particle size analyzer. For example, a Horiba LA-950 laser particle size analyzer can be used as a particle size distribution analyzer. When particle size is measured using a particle size distribution analyzer, the average particle size (or particle size) is called D50. D50 refers to the average particle size (or particle size) of particles whose cumulative volume corresponds to 50 vol% in a particle size distribution (e.g., cumulative distribution). In a distribution curve accumulating from smallest to largest particle sizes, D50 refers to the particle size value corresponding to 50% of the smallest particles when the total number of particles is 100%.

[0061] 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. When a battery insulation sheet is produced using an aerogel composition containing aerogel in this range, the heat insulating properties of the battery insulation sheet can be improved.

[0062] In one embodiment, the binder may include a water-based polymer binder, for example, the water-based polymer binder may include at least one selected from the group consisting of a water-soluble polymer, an anionic water-soluble polymer, a cationic water-soluble polymer, and a water-dispersible polymer.

[0063] The aqueous polymer may include, but is not limited to, one or more selected from the group consisting of polyvinyl alcohol, polyethylene oxide, polyacrylamide, and polyvinylpyrrolidone.

[0064] The anionic water-soluble polymer may include at least one 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.

[0065] The cationic water-soluble polymer may include 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 may include at least one selected from the group consisting of polyethylene amine and polyamine, but are not limited thereto.

[0066] The water-dispersible polymer may include, but is not limited to, one or more selected from the group consisting of water-dispersible polyurethane and water-dispersible polyester.

[0067] The binder may include a water-based polymer and a water-dispersible polymer. For example, the binder may include a water-based polymer having binder and dispersing properties and a water-dispersible polyurethane having fire-resistant properties. A specific example of the binder may include polyvinyl alcohol and a water-dispersible polyurethane.

[0068] 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 aqueous polymer and the water-dispersible polymer are mixed and used in a weight ratio 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.

[0069] 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. When a battery insulation sheet is manufactured using an aerogel composition containing a binder within this range, the dust resistance of the battery insulation sheet can be improved.

[0070] In one embodiment, the dispersant may include at least one selected from the group consisting of surfactants and phosphate salts, including, but not limited to, at least one of nonionic surfactants, anionic surfactants, amphoteric surfactants, natural surfactants such as lecithin, and phosphate salts.

[0071] When the dispersant is further contained, the dispersion of the aerogel in the composition can be further improved, and the fibrous support and the aerogel can be uniformly dispersed.

[0072] 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. When the dispersant is contained within the above range, a battery insulation sheet with excellent heat insulation properties, compressibility, and dust resistance can be produced.

[0073] 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 mixed in a weight ratio within this range, the aerogel may be more uniformly dispersed in the aerogel layer.

[0074] In one embodiment, the aerogel layer may contain 5 wt % to 70 wt % of the fibrous support, 10 wt % to 90 wt % of the aerogel, and 0.5 wt % to 20 wt % of the functional material, based on the total weight of the aerogel layer.

[0075] For example, 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, based on the total weight of the aerogel layer.

[0076] Specifically, the aerogel layer may contain, relative to the total weight 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. When the aerogel layer is formed within these ranges, excellent heat insulation can be realized, durability can be improved, and the bonding strength between the fibrous support and the aerogel can be improved, preventing dust generation.

[0077] As another example, the aerogel layer may contain, relative to the total weight of the aerogel layer, 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 5% by weight of the dispersant.

[0078] Specifically, the aerogel layer may contain, relative to the total weight 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. When the aerogel layer is formed within these ranges, the dispersibility of the aerogel can be improved, excellent heat insulation can be realized, and durability can be improved. The bonding strength between the fibrous support and the aerogel can be improved, preventing dust generation.

[0079] In one embodiment, the aerogel layer may have a single layer structure or a multi-layer structure. When the aerogel layer has a multi-layer structure, the aerogel layer may have 2 to 10 layers, 2 to 7 layers, or 2 to 5 layers.

[0080] A method for manufacturing a battery insulation sheet according to one embodiment includes coating an aerogel composition on a substrate; and drying the aerogel composition coated on the substrate to form an aerogel layer. The aerogel layer may include a fibrous support, an aerogel, and a functional material including a binder, a dispersant, or a combination thereof, and may satisfy the following formula 1. The specific descriptions regarding the substrate and the aerogel layer are as described above. The substrate may refer to the substrate of FIG. 2 or one of the first and second substrates of FIG. 3.

[0081] [Formula 1] 50≦A≦100000, A=T i / D s

[0082] In the above formula 1, the above T i is the thickness of the aerogel layer, and D s is the average diameter of the fibrous support.

[0083] The method for producing the aerogel composition may include the steps of: mixing a functional material, including a binder, a dispersant, or a combination thereof, with a solvent to produce a solvent mixture; mixing the solvent mixture with an aerogel to produce an aerogel mixture; and mixing the aerogel mixture with a fibrous support to produce an aerogel composition.

[0084] 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, as described above.

[0085] In one embodiment, the solvent may include at least one selected from the group consisting of polar solvents and non-polar solvents.

[0086] The polar solvent may include one or more selected from the group consisting of water and alcohol-based solvents.

[0087] The water may include, for example, purified water, deionized water, or a combination thereof.

[0088] The alcohol-based solvent may include, 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.

[0089] The non-polar solvent may include a hydrocarbon solvent, for example, one or more 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.

[0090] 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 hydrophobic aerogel. In one embodiment, however, the aerogel is uniformly dispersed by controlling the design of the mixing step, mixing conditions, and the amounts of binder and dispersant added. When the aerogel is uniformly dispersed in the composition, a thin battery insulation sheet with excellent insulation properties, compressibility, and low dust can be formed without using a large amount of binder.

[0091] 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 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, the viscosity can be controlled and the aerogel layer can be coated.

[0092] In the step of preparing the aerogel mixture by mixing the solvent mixture with the aerogel, the aerogel may be added in a powder form, and the specific description of the aerogel is as described above.

[0093] In the step of preparing an aerogel composition by mixing the aerogel mixture with the fibrous support, the specific description of the fibrous support is as described above.

[0094] In one embodiment, the aerogel composition may further include a silane-based compound. The silane-based compound may include at least one selected from the group consisting of 3-(trimethoxysilyl)propylmethacrylate, methyltriethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, octadecyltrimethoxysilane, ethyltriethoxysilane, and 3-glycidoxypropyltrimethoxysilane. When the silane-based compound is further included, dispersibility can be further improved.

[0095] In each of the steps of mixing the 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, a mixer may be used during mixing. For example, the mixer may include, but is not limited to, a planetary mixer or a thinky mixer.

[0096] For example, a planetary mixer can be used to mix the solvent mixture with the aerogel. When the planetary mixer is used to mix the solvent mixture with the aerogel, the aerogel can be uniformly dispersed in the solvent.

[0097] The planetary mixer may be a device that can be used to mix or agitate other materials to produce a homogeneous mixture. It may include blades capable of planetary motion.

[0098] 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.

[0099] The planetary blades and high-speed dispersion blades rotate continuously about their axes, and the rotational speed can be expressed in units of rotations per minute (rpm).

[0100] 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 between 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.

[0101] 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.

[0102] When the functional material is mixed with the solvent, the rotation speed of the first blade of the mixer 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. When the solvent and functional material are mixed as described above, a solvent mixture in which the binder, dispersant, or a combination thereof is uniformly dispersed is prepared, which makes it easier to mix the aerogel in the subsequent step.

[0103] When mixing the solvent mixture with the aerogel, 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 is added to the solvent mixture and mixed as described above, it is possible to prevent the aerogel from agglomerating with each other and induce uniform dispersion.

[0104] When mixing the aerogel mixture with 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 mixing the aerogel mixture with the fibrous support as described above, air bubbles within the composition are removed, the viscosity is adjusted, and the fibrous support is easily dispersed among the uniformly dispersed aerogel. The aerogel may even be present in a form in which it surrounds the fibrous support within the composition. Here, a binder may be present between the aerogel and the fibrous support, which can improve the bonding strength between the aerogel and the fibrous support.

[0105] The coating step may be performed by applying an aerogel slurry onto a conventional substrate.

[0106] The coating step may be repeated once or more than once.

[0107] The drying step may be performed at a temperature of, for example, 25° C. to 100° C., 45° C. to 90° C., or 60° C. to 85° C. Drying under these temperature conditions may prevent detachment between the substrate and the aerogel layer, and a robust aerogel layer may be formed on the substrate without the use of a separate adhesive or bonding material, and a coating layer may be formed in which the aerogel coats the peripheries of a plurality of dispersed fibrous supports.

[0108] In one embodiment, the method for manufacturing a battery insulation sheet may further include laminating a substrate on the coated aerogel composition before drying. In this case, a battery insulation sheet may be manufactured having a structure in which multiple substrates, for example, a first substrate and a second substrate, are formed on both sides of the aerogel layer without an adhesive layer.

[0109] According to one embodiment of the manufacturing method for a battery insulation sheet, a battery insulation sheet can be manufactured using a simple method of coating the sheet on a substrate and drying it, without using a separate adhesive or forming an adhesive layer. The aerogel is uniformly dispersed and has excellent compression properties, so that the battery insulation sheet can achieve excellent insulation and low dust properties even at a thin thickness.

[0110] In one embodiment, when preparing the aerogel layer, additives such as wetting agents, emulsifiers, compatibilizers, viscosity modifiers, pH adjusters, stabilizers, antioxidants, acidic or basic scavengers, metal deactivators, antifoaming agents, antistatic agents, thickeners, adhesion improvers, binders, flame retardants, impact modifiers, pigments, dyes, colorants, and deodorizers may be optionally added.

[0111] Specific examples of the present invention will be presented below. However, the examples described below are merely for the purpose of specifically illustrating and explaining the present invention, and the present invention is not limited thereto. Furthermore, since the contents not described here can be sufficiently inferred by those skilled in the art, the description thereof will be omitted.

[0112] (Manufacture of battery insulation sheets) Example 1 1. Preparation of Aerogel Composition Polyvinyl alcohol (Sigma Aldrich, Poly(vinyl alcohol)) was added as a binder to ultrapure water as a solvent, and mixed under conditions of an open blade of 30 rpm and a despa blade of 700 rpm to produce a solvent mixture. 2 An aerogel mixture was produced by adding 1 / g of aerogel and mixing with an open blade at 70 rpm and a Despa blade at 1500 rpm. Glass wool with an average diameter of 0.12 μm to 5 μm was added as a fibrous support to the aerogel mixture, and mixing was performed with an open blade at 30 rpm and a Despa blade at 1200 rpm to produce an aerogel composition. A planetary mixer (DNTEK, PT-005) was used for mixing.

[0113] The solid content of the prepared aerogel composition was confirmed to be 50 wt % aerogel, 40 wt % glass wool, and 10 wt % polyvinyl alcohol.

[0114] 2. Battery insulation sheet manufacturing The aerogel composition was slurry-coated on a 0.1 mm thick mica sheet (Famica, Muscovite), and then another 0.1 mm thick mica sheet was sandwiched between them and rolled to form a coating. The resulting mixture was then dried at 60°C for 24 hours to form an aerogel layer, producing a battery insulation sheet. The thickness of the aerogel layer was 1.18 mm, and the total thickness of the battery insulation sheet was 1.38 mm.

[0115] Example 2 The aerogel composition was prepared in the same manner as in Example 1, except that the amounts of raw materials added were adjusted to prepare an aerogel composition having a solid content of 60 wt % aerogel, 25 wt % glass wool, and 15 wt % polyvinyl alcohol.

[0116] Example 3 The aerogel composition was prepared in the same manner as in Example 1, except that the amounts of raw materials added were adjusted to prepare an aerogel composition having a solid content of 65 wt % aerogel, 25 wt % glass wool, and 10 wt % polyvinyl alcohol.

[0117] Example 4 The aerogel composition was prepared in the same manner as in Example 1, except that the amounts of raw materials added were adjusted to prepare an aerogel composition having a solid content of 45 wt % aerogel, 50 wt % glass wool, and 5 wt % polyvinyl alcohol.

[0118] Example 5 An aerogel composition was prepared in the same manner as in Example 1, except that the amounts of raw materials added were adjusted to prepare an aerogel composition having a solid content of 50 wt % aerogel, 49.7 wt % glass wool, and 0.3 wt % polyvinyl alcohol.

[0119] Example 6 The aerogel composition was prepared in the same manner as in Example 1, except that the amounts of raw materials added were adjusted to prepare an aerogel composition having a solid content of 40 wt % aerogel, 35 wt % glass wool, and 25 wt % polyvinyl alcohol.

[0120] Example 7 The aerogel composition was prepared using glass wool having an average diameter of 0.1 μm to 3 μm as the fibrous support, and the battery insulation sheet was prepared in the same manner as in Example 1, except that the thickness of the aerogel layer was adjusted to 1.3 mm.

[0121] Example 8 The aerogel composition was prepared in the same manner as in Example 1, except that glass wool having an average diameter of 10 μm to 15 μm was used as the fibrous support, and the thickness of the aerogel layer was adjusted to 1.3 mm when preparing the battery insulation sheet.

[0122] Example 9 The aerogel composition was prepared in the same manner as in Example 1, except that water-dispersible polyurethane was used as the binder instead of polyvinyl alcohol.

[0123] Example 10 1. Preparation of Aerogel Composition Polyvinyl alcohol (Sigma Aldrich, Poly(vinyl alcohol)) as a binder and surfactant (Triton-X100, Sigma Aldrich) as a dispersant were added to the ultrapure water solvent, and mixed at an open blade speed of 30 rpm and a desparate blade speed of 700 rpm to produce a solvent mixture. 2 An aerogel mixture was produced by adding 1 / g of aerogel and mixing with an open blade at 70 rpm and a Despa blade at 1500 rpm. Glass wool with an average diameter of 0.12 μm to 5 μm was added as a fibrous support to the aerogel mixture, and mixing was performed with an open blade at 30 rpm and a Despa blade at 1200 rpm to produce an aerogel composition. A planetary mixer (DNTEK, PT-005) was used for mixing.

[0124] The solid content of the prepared aerogel composition was confirmed to be 50 wt % aerogel, 40 wt % glass wool, 9.9 wt % polyvinyl alcohol, and 0.1 wt % dispersant.

[0125] 2. Battery insulation sheet manufacturing The prepared aerogel composition was applied as a slurry onto a 0.1 mm thick mica sheet (Famica, Muscovite), and then another 0.1 mm thick mica sheet was sandwiched and rolled to form a coating. The aerogel layer was then dried at 60°C for 24 hours to prepare a battery insulation sheet. The thickness of the aerogel layer was 1.18 mm, and the total thickness of the battery insulation sheet was 1.38 mm.

[0126] Example 11 1. Preparation of Aerogel Composition Polyvinyl alcohol (Sigma Aldrich, Poly(vinyl alcohol)) as a binder, water-dispersible polyurethane, and surfactant (Triton-X100, Sigma Aldrich) as a dispersant were added to ultrapure water as a solvent, and 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 produced by adding 1 / g of aerogel and mixing with an open blade at 70 rpm and a Despa blade at 1500 rpm. Glass wool with an average diameter of 0.12 μm to 5 μm was added as a fibrous support to the aerogel mixture, and mixing was performed with an open blade at 30 rpm and a Despa blade at 1200 rpm to produce an aerogel composition. A planetary mixer (DNTEK, PT-005) was used for mixing.

[0127] The solid content of the prepared aerogel composition was confirmed to be 50 wt % aerogel, 40 wt % glass wool, 3 wt % polyvinyl alcohol, 6.9 wt % water-dispersible polyurethane, and 0.1 wt % dispersant.

[0128] 2. Battery insulation sheet manufacturing The prepared aerogel composition was applied as a slurry onto a 0.1 mm thick mica sheet (Famica, Muscovite), and then another 0.1 mm thick mica sheet was sandwiched and rolled to form a coating. The aerogel layer was then dried at 60°C for 24 hours to prepare a battery insulation sheet. The thickness of the aerogel layer was 1.18 mm, and the total thickness of the battery insulation sheet was 1.38 mm.

[0129] Comparative Example 1 The aerogel composition was prepared in the same manner as in Example 1, except that the aerogel layer thickness was adjusted to 1.18 mm when preparing the battery insulation sheet, using glass wool having an average diameter of 30 μm to 40 μm as the fibrous support.

[0130] Comparative Example 2 The aerogel composition was prepared using glass wool having an average diameter of 0.01 μm to 0.015 μm as the fibrous support, and the battery insulation sheet was prepared in the same manner as in Example 1, except that the thickness of the aerogel layer was adjusted to 1.18 mm.

[0131] (Experimental example) Experimental example 1: SEM analysis The cross section of the aerogel layer of the battery insulation sheet prepared in Example 1 was observed using a Hitachi S-4800 SEM, and analysis was performed after Pt coating. The results are shown in Figure 4 below. Specifically, Figure 4 shows SEM images of the battery insulation sheet prepared in Example 1 taken at 300 magnifications (X300) and 800 magnifications (X800).

[0132] Figure 4 shows that the battery insulation sheet of Example 1 manufactured by the method of the present invention exhibits a unique structure. Specifically, when an aerogel layer is formed by impregnating a fiber blanket with an aerogel precursor at low temperature under reduced pressure, gelling the aerogel, and then supercritical drying it, there is a limit to the amount of aerogel that can be added, making it difficult to accurately add the aerogel. Furthermore, the aerogel is embedded in large particles on the surface of the blanket, which tends to fall off and generate a large amount of dust. However, Figure 4 shows that the aerogel coats a fibrous support, allowing the battery insulation sheet of the present invention to exhibit excellent insulation, compression, and low dust properties.

[0133] Experimental example 2: Evaluation of thermal insulation The heat insulating properties were evaluated using the heat insulating sheets produced in Examples 1 to 11 and Comparative Examples 1 and 2.

[0134] Specifically, each heat insulating sheet was inserted between a pair of opposing 1 mm 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 maintained at an initial temperature of 40°C. A pressure of 20 kN was then applied to the lower plate of the heat press, and the temperature of the lower plate of the heat press was measured after 11 minutes. The results are shown in Table 1 below.

[0135] Experimental example 3: Dust evaluation The heat insulating sheets produced in Examples 1 to 11 and Comparative Examples 1 and 2 were used to evaluate dustiness.

[0136] Specifically, the weight of each insulation sheet was measured before the evaluation. Then, the insulation sheet was placed on a rubber plate and hit with a rubber hammer at five points (tops and center) to remove dust, and then the weight of the insulation sheet was measured. The weight before and after the physical impact was compared to calculate the weight loss rate, and the results are shown in Table 1 below.

[0137] Experimental Example 4: Evaluation of compression characteristics The heat insulating sheets manufactured in Examples 1 to 11 and Comparative Examples 1 and 2 were used to evaluate compression characteristics.

[0138] Specifically, the zero point was taken using UTM equipment, and each insulation sheet was sandwiched between 1mm thick aluminum plates, and the compression rate was measured from 0kN to 80kN at a compression speed of 0.02mm / sec. The thickness was then measured at 5kN and 40kN, and the thickness reduction rate was expressed as the compression rate. The results are shown in Table 1 below.

[0139] [Table 1]

[0140] Referring to Table 1, it was confirmed that Examples 1 to 11 all exhibited excellent insulation properties, dust resistance, and compression properties. Looking at Examples 1 to 4, it was confirmed that insulation properties, dust resistance, and compression properties changed depending on the component content of the aerogel composition. In Example 5, dust resistance and compression properties slightly decreased with the change in the components of the aerogel composition, but insulation properties improved. In Example 6, insulation properties and compression properties slightly decreased. Looking at Examples 1, 7, and 8, it was confirmed that insulation properties, dust resistance, and compression properties changed depending on the A value. It was confirmed that when the A value was between 200 and 10,000, excellent insulation properties and dust resistance were achieved without a decrease in compression properties. In Example 9, dust resistance decreased slightly because the binder did not function as a dispersant, but insulation properties improved. Looking at Example 10, where a binder and dispersant were mixed, it was confirmed that insulation properties, dust resistance, and compression properties improved. Furthermore, in Example 11, it was confirmed that when polyvinyl alcohol, which can act as a dispersant, was mixed with a water-dispersible polyurethane binder, which cannot act as a dispersant, the heat insulation, dust resistance, and compressibility were further improved.

[0141] Furthermore, looking at Comparative Examples 1 and 2, it was confirmed that the A value was not satisfied, and therefore the heat insulating properties, dust resistance and compressibility were all significantly reduced.

[0142] Therefore, it was confirmed that the aerogel composition according to an embodiment has excellent heat insulation properties, compressibility, and low dust properties.

[0143] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the claims, the detailed description of the invention, and the accompanying drawings, and it goes without saying that these modifications also fall within the scope of the present invention. [Explanation of symbols]

[0144] 100 Battery Heat Insulation Sheet 110 Base material 120 aerogel layer 130 1st base material 140 Second base material 200 cells

Claims

1. a substrate; an aerogel layer formed on the substrate; The aerogel layer comprises a fibrous support; an aerogel; and a functional material comprising a binder or a combination of a binder and a dispersant; the binder comprises a water-based polymer binder; the aqueous polymer binder includes a water-dispersible polymer, A battery insulation sheet that satisfies the following formula 1: [Formula 1] 50≦A≦100000、A=T ｉ / D ｓ In the above formula 1, the T ｉ is the thickness of the aerogel layer, and ｓ is the average diameter of the fibrous support.

2. The battery insulating sheet according to claim 1 , wherein the aerogel layer has a thickness of 1 mm to 10 mm.

3. The battery insulating sheet according to claim 1 , wherein the average diameter of the fibrous support is 0.1 μm to 20 μm.

4. The battery insulating sheet according to claim 1, wherein A is 200 to 10,000.

5. The battery insulating sheet according to claim 1 , wherein the surface of the fibrous support is coated with an aerogel.

6. The battery insulating sheet according to claim 1 , wherein the substrate comprises at least one material selected from the group consisting of resins, metals, and inorganic materials other than metals.

7. 2. The battery insulating sheet according to claim 1, wherein the fibrous support comprises at least one fiber selected from the group consisting of natural fibers, silica fibers, glass fibers, carbon fibers, basalt fibers, and polymer fibers.

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

9. The battery insulating sheet according to claim 1 , wherein the water-based polymer binder further comprises at least one selected from the group consisting of a water-based polymer, an anionic water-soluble polymer, and a cationic water-soluble polymer.

10. The battery insulating sheet according to claim 1 , wherein the binder is contained in an amount of 0.5% by weight to 20% by weight based on the total weight of the aerogel layer.

11. The binder includes a water-soluble polymer and a water-dispersible polymer, The battery insulating sheet according to claim 1 , wherein the water-based polymer and the water-dispersible polymer are contained in a weight ratio of 1:1 to 1:

5.

12. The battery insulating sheet according to claim 1 , wherein the dispersant comprises at least one selected from the group consisting of a surfactant and a phosphate-based salt.

13. The battery insulating sheet according to claim 1 , wherein the dispersant is contained in an amount of 0.1% by weight to 6% by weight based on the total weight of the aerogel layer.

14. The battery insulating sheet according to claim 1 , wherein the binder and the dispersant are contained in a weight ratio of 1:0.001 to 1:0.

67.

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

16. 2. The battery insulating sheet according to claim 1, wherein the aerogel layer comprises, relative to the total amount of the aerogel layer, 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.

17. 2. The battery insulating sheet according to claim 1, wherein the aerogel layer contains, relative to a total amount of the aerogel layer, 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 5% by weight of the dispersant.

18. Coating the aerogel composition on a substrate; and drying the aerogel composition coated on the substrate to form an aerogel layer. The aerogel layer comprises a fibrous support; an aerogel; and a functional material comprising a binder or a combination of a binder and a dispersant; the binder comprises a water-based polymer binder; the aqueous polymer binder includes a water-dispersible polymer, A method for producing a battery insulating sheet that satisfies the following formula 1: [Formula 1] 50≦A≦100000、A=T ｉ / D ｓ In the above formula 1, the T ｉ is the thickness of the aerogel layer, and ｓ is the average diameter of the fibrous support.

19. The method for producing the aerogel composition includes: mixing a functional material including a binder or a combination of a binder and a dispersant with a solvent to prepare a solvent mixture; mixing the solvent mixture with aerogel to prepare an aerogel mixture; and mixing the aerogel mixture with a fibrous support to produce an aerogel composition.

20. The method for manufacturing a battery insulating sheet according to claim 19, wherein the solvent includes at least one selected from the group consisting of polar solvents and non-polar solvents.

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