Aerogel composition for battery heat insulating sheet, method for producing the same, battery heat insulating sheet formed using the same, and battery module including the same

Abstract

To provide an aerogel composition for battery thermal insulation sheets excellent in thermal insulation and fire resistance, a method of manufacturing the same, a battery thermal insulation sheet formed using the same, and a battery module including the same.SOLUTION: A battery thermal insulation sheet 100 has a structure comprising: a first substrate 110; an aerogel layer 120 formed on the first substrate 110; and a second substrate 130 formed on the aerogel layer 120. The first and second substrates are arranged to face cells adjacent thereto, respectively, and are formed from substances identical to or different from each other. An aerogel composition forming the aerogel layer contains, based on the total weight of solids in the aerogel composition, 55 wt.% to 75 wt.% of aerogel, 20 wt.% to 40 wt.% of a binder, and 0.1 wt.% to 8 wt.% of a phosphorus-based material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an aerogel composition for a battery insulation sheet, a method for producing the same, a battery insulation sheet formed using the same, and a battery module including the same. [Background technology]

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

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

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

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

[0006] One embodiment provides an aerogel composition for a battery insulation sheet having excellent thermal insulation properties and heat resistance, a method for manufacturing the same, a battery insulation sheet formed using the same, and a battery module including the same. [Means for solving the problem]

[0007] One embodiment provides an aerogel composition for a battery insulation sheet, comprising: an aerogel; a binder; or a functional material comprising the binder and a dispersant; and a solvent, wherein the binder comprises a first binder comprising a water-based polymer binder and a second binder comprising a fluorocarbon-based binder.

[0008] The aerogel has a BET specific surface area of ​​500 m 2 / g~1,000m 2 / g.

[0009] The aerogel may be contained in an amount of 30% by weight to 70% by weight based on the total solid content of the aerogel composition.

[0010] The aqueous polymer binder may include at least one selected from the group consisting of aqueous polymers, anionic water-soluble polymers, cationic water-soluble polymers, and water-dispersible polymers.

[0011] The fluorocarbon binder may include at least one selected from the group consisting of polytetrafluoroethylene, polyvinylidene fluoride, and polyvinylidene fluoride-hexapropylene copolymer.

[0012] The first binder and the second binder may be included in a weight ratio of 0.1:1 to 20:1.

[0013] When the functional material includes the dispersant, the dispersant may include one or more selected from the group consisting of surfactants and phosphate salts.

[0014] The functional material may be contained in an amount of 30% by weight to 70% by weight based on the total solid content of the aerogel composition.

[0015] The solvent may include one or more selected from the group consisting of polar solvents and non-polar solvents.

[0016] The weight ratio of the solvent to the total amount of solids in the aerogel composition may be 1:1 to 1:90.

[0017] The aerogel composition may further include a flame retardant containing a phosphorus-based material.

[0018] The phosphorus-based material may include at least one of phosphate-based ammonium salt, red phosphorus, and compounds represented by the following formulas (1) and (2).

[0019] [ka]

[0020] In formula (1), Ar 1 ~Ar 3 are each independently a substituted or unsubstituted C6 to C20 aryl group.

[0021] JPEG0007734232000002.jpg59139

[0022] In formula (2), Ar 4 ~Ar 10 are each independently a substituted or unsubstituted C6 to C20 aryl group.

[0023] The flame retardant may be included in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the functional material.

[0024] The aerogel composition may contain 40% by weight to 60% by weight of the aerogel, 10% by weight to 50% by weight of the first binder, and 1% by weight to 45% by weight of the second binder, relative to the total solid content of the aerogel composition.

[0025] When the functional substance includes the dispersant, the aerogel composition may include, relative to the total solid content of the aerogel composition, 40 wt % to 60 wt % of the aerogel, 10 wt % to 50 wt % of the first binder, 1 wt % to 45 wt % of the second binder, and 0.1 wt % to 5 wt % of the dispersant.

[0026] When the functional material includes the dispersant, the aerogel composition may include, relative to the total solid content of the aerogel composition, 40% by weight to 60% by weight of the aerogel, 10% by weight to 50% by weight of the first binder, 1% by weight to 45% by weight of the second binder, 0.1% by weight to 5% by weight of the dispersant, and 0.1% by weight to 8% by weight of the flame retardant.

[0027] Another embodiment provides a method for producing an aerogel composition for a battery insulation sheet, the method comprising: mixing a functional material including a binder or the binder and a dispersant with a solvent to prepare a solvent mixture; and mixing the solvent mixture with an aerogel to prepare an aerogel composition, wherein the binder includes a first binder including a water-based polymer binder and a second binder including a fluorocarbon-based binder.

[0028] Yet another embodiment may provide a battery insulation sheet including a first substrate, a second substrate, and an aerogel layer formed between the first substrate and the second substrate, wherein the aerogel layer is formed using the aerogel composition.

[0029] Yet another embodiment may provide a battery module including a plurality of cells and the battery insulation sheets respectively disposed between the plurality of cells, wherein the first substrate and the second substrate are each disposed to face an adjacent cell. [Effects of the Invention]

[0030] The battery insulation sheet according to an embodiment may have thermal insulation properties and heat resistance, and a battery module including the battery insulation sheet according to an embodiment may be able to suppress the spread of heat and flames between adjacent cells due to thermal runaway of a cell. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a schematic diagram illustrating a structure of a battery insulation sheet according to an embodiment. [Figure 2] 1 is a schematic diagram illustrating a battery insulation sheet formed between a plurality of cells according to an embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0032] The following detailed description of the embodiments will be made in order to enable those skilled in the art to easily implement the present invention, but the embodiments may be realized in various different forms and are not limited to the embodiments described herein.

[0033] Insulation is a material that prevents heat from moving from high temperature areas to low temperature areas, and is used in refrigerators, freezer warehouses, buildings, and various industrial sectors including the aircraft, electronics, and automotive industries.

[0034] Such a heat insulating material must have excellent heat insulating properties due to low thermal conductivity, and must also have sufficient mechanical strength to maintain such heat insulating properties.

[0035] Meanwhile, aerogel is a transparent or translucent cutting-edge material with a nanoporous structure. It has extremely low density and low thermal conductivity, and therefore has great potential as an insulating material. It is also considered a highly efficient super-insulating material that can be used in a variety of industrial fields.

[0036] Furthermore, the greatest advantage of aerogel is that it exhibits lower thermal conductivity than conventional organic insulation materials such as styrofoam, and that it can solve the fatal weaknesses of organic insulation materials, namely their vulnerability to fire and the generation of toxic gases during a fire.

[0037] According to one embodiment, the aerogel composition for a battery insulation sheet includes an aerogel, a functional material including a binder or a binder and a dispersant, and a solvent. The binder may include a first binder including a water-based polymer binder and a second binder including a fluorocarbon-based binder.

[0038] The battery insulation sheet made of the aerogel composition comprising the above-mentioned components has excellent insulation properties and heat resistance, and can suppress the spread of heat and flames to adjacent cells due to thermal runaway of the cells.

[0039] 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.

[0040] 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 a particle size within the above range, the heat insulating properties can be improved and heat transfer between multiple cells can be delayed.

[0041] The average particle size (D50) can be measured, for example, using a laser diffraction method or a scanning electron microscope (SEM) photograph, and the average particle size (D50) of particles can be defined as the particle size at 50% of the particle size distribution (the particle size corresponding to 50% of the cumulative volume of the particle size distribution).

[0042] The aerogel content may be 30 to 70 wt %, 40 to 60 wt %, or 45 to 55 wt % based on the total solid content of the aerogel composition. By producing a battery insulation sheet using an aerogel composition containing aerogel within the above range, the heat insulating properties of the battery insulation sheet can be improved.

[0043] In one embodiment, the binder may include a first binder including a water-based polymer binder and a second binder including a fluorocarbon-based binder.

[0044] The aqueous polymer binder can include, for example, one or more selected from the group consisting of aqueous polymers, anionic water-soluble polymers, cationic water-soluble polymers, and water-dispersible polymers.

[0045] The water-soluble polymer may include, but is not limited to, one or more selected from the group consisting of polyvinyl alcohol, polyethylene oxide, polyacrylamide, and polyvinylpyrilidone.

[0046] The anionic water-soluble polymer may include at least one selected from the group consisting of polymers having functional groups of 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.

[0047] 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, but are not limited to, at least one selected from the group consisting of polyethylene amine and polyamine.

[0048] 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.

[0049] The content of the first binder may be 10 to 50 wt%, 20 to 48 wt%, or 25 to 45.5 wt%, based on the total solid content of the aerogel composition. By producing a battery insulation sheet using an aerogel composition containing a first binder within the above range, the heat insulation properties, durability, and dust resistance of the battery insulation sheet can be improved.

[0050] The fluorocarbon binder may include a heat-resistant binder, and may include, for example, one or more selected from the group consisting of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and polyvinylidene fluoride-hexapropylene (PVDF-HFP) copolymer.

[0051] The content of the second binder may be 1 to 45 wt%, 3 to 35 wt%, or 4.5 to 25 wt%, based on the total solid content of the aerogel composition. By producing a battery insulation sheet using an aerogel composition containing a second binder within the above range, the heat resistance, durability, and dust resistance of the battery insulation sheet can be improved.

[0052] The first binder and the second binder may be included in a weight ratio of 0.1:1 to 20:1, 1:1 to 15:1, or 1:1 to 10:1. By mixing the first binder and the second binder within the above ranges, it is possible to improve the heat insulation property and heat resistance.

[0053] In one embodiment, the dispersant may include at least one selected from the group consisting of surfactants and phosphate salts. Specific examples of the dispersant include, but are not limited to, at least one of nonionic surfactants, anionic surfactants, amphoteric surfactants, natural surfactants such as lecithin, and phosphate salts.

[0054] When a dispersant is further contained, the dispersion of the aerogel in the composition is further improved, the aerogel is dispersed uniformly, and the heat insulating properties can be improved.

[0055] 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 solid content of the aerogel composition. By including a dispersant within the above range, the aerogel composition can be produced at low cost, and a battery insulation sheet having excellent heat insulation properties, durability, and dust resistance can be produced using this.

[0056] In one embodiment, the binder and 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. Mixing the binder and dispersant in a weight ratio within the above ranges may allow the aerogel to be more uniformly dispersed in the aerogel layer.

[0057] The functional substance may be contained in an amount of 30% to 70% by weight, 40% to 60% by weight, or 45% to 55% by weight relative to the total solid content of the aerogel composition.

[0058] In one embodiment, the solvent may include one or more selected from the group consisting of polar solvents and non-polar solvents.

[0059] The polar solvent may include water, an alcohol-based solvent, or a combination thereof.

[0060] The water may include, for example, purified water, deionized water, or a combination thereof.

[0061] 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.

[0062] 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 is preferably, but not limited to, an alkane solvent such as hexane, or a mixture containing an alkane solvent.

[0063] 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 mixing step design, mixing conditions, and the addition and amounts of binder and dispersant. Uniform dispersion of the aerogel in the composition in this manner allows for the formation of a thin battery insulation sheet with excellent insulation properties, durability, and low dusting, even without using a large amount of binder.

[0064] The solvent may be contained in such a way that the weight ratio of the solvent to the total solid content of the aerogel composition is 1:1 to 1:90. For example, the weight ratio of the solvent to the total solid content of the aerogel composition may be 1:50 to 1:70, 1:20 to 1:30, or 1:2 to 1:10. By controlling the weight ratio of the solvent to the total solid content within the above range, the viscosity can be controlled and an aerogel layer can be coated.

[0065] In one embodiment, the phosphorus-based material can include any material that has flame retardant properties and contains phosphorus.

[0066] The phosphorus-based substance may include, for example, one or more of phosphate-based ammonium salts, red phosphorus, and compounds represented by the following formulas (1) and (2).

[0067] The phosphate-based ammonium salt may include one or more selected from the group consisting of anhydrous ammonium phosphate, diammonium hydrogen phosphate, ammonium polyphosphate, and monoammonium phosphate. As a specific example, the phosphorus-based material may include anhydrous ammonium phosphate. When the phosphate-based ammonium salt is included, char is formed by phosphorylation when the ambient temperature increases due to thermal runaway of the cell, thereby blocking the transfer of heat to other cells.

[0068] Any commercially available red phosphorus can be used as a flame retardant. For example, red phosphorus is an allotrope of elemental phosphorus (P) and is obtained as a reddish-purple amorphous powder.

[0069] The red phosphorus may be microencapsulated in a polymer such as a phenol-formaldehyde resin. Microencapsulation can prevent direct contact between the red phosphorus and external components when the red phosphorus is stored together with one of the catalyst components, thereby extending the storage time. Microencapsulated red phosphorus can be prevented from being hydrolyzed to unstable volatile compounds such as phosphine.

[0070] [ka]

[0071] In formula (1), Ar 1 ~Ar 3 are each independently a substituted or unsubstituted C6 to C20 aryl group. For example, Ar 1 ~Ar 3 are each independently a substituted or unsubstituted C6 to C18 aryl group or a C6 to C12 aryl group.

[0072] [ka]

[0073] In formula (2), Ar 4 ~Ar 10 are each independently a substituted or unsubstituted C6 to C20 aryl group. For example, Ar 4 ~Ar 10 are each independently a substituted or unsubstituted C6 to C18 aryl group or a C6 to C12 aryl group.

[0074] The phosphorus-based materials represented by the above formulas (1) and (2) form polyphosphoric acid when the ambient temperature increases, and the polyphosphoric acid undergoes esterification and dehydrogenation reactions to form a carbon layer. The carbon layer thus formed can provide a flame retardant effect by blocking oxygen and latent heat.

[0075] For purposes of this invention, an "aryl group" is defined as a monovalent substituent derived from an aromatic hydrocarbon.

[0076] Specific examples of the aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthryl group, a naphthacenyl group, a tolyl group, a biphenylyl group, a terphenylyl group, a fluoranthenyl group, a fluorenyl group, a perylenyl group, an indenyl group, an azulenyl group, a heptalenyl group, a phenalenyl group, and a phenanthrenyl group.

[0077] In the above formula (1) and formula (2), Ar 1 ~Ar 10 may each be substituted or unsubstituted with an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a halogen group, a cyano group, or a trimethylsilyl group.

[0078] In the present invention, the term "C#", where "#" is a positive integer, refers to any hydrocarbon having # carbon atoms. Thus, the term "C6" refers to a hydrocarbon compound having 6 carbon atoms, and the term "C20" refers to a hydrocarbon compound having 20 carbon atoms.

[0079] The flame retardant may be contained in an amount of 0.01 to 20 wt%, 0.1 to 10 wt%, or 0.25 to 5 wt%, based on the total solid content of the aerogel composition. When the phosphorus-based substance is contained within the above range, the heat resistance as well as the heat insulating properties of the heat insulating sheet are improved, and heat transfer between cells can be blocked.

[0080] The flame retardant may be included in an amount of 0.1 to 20 parts by weight, 0.5 to 17 parts by weight, or 1 to 10 parts by weight per 100 parts by weight of the functional material. If the content of the phosphorus-based material relative to the content of the functional material is controlled within the above range, char is formed when the heat insulating sheet is exposed to a high-temperature environment, and this char can act as a flame shield, resulting in excellent heat resistance of the heat insulating sheet and preventing the spread of heat and flames to adjacent cells due to thermal runaway of the cells.

[0081] In one embodiment, the aerogel composition may include, based on the total solid content of the aerogel composition, 40% to 60% by weight of the aerogel, 20% to 48% by weight of the first binder, and 3% to 35% by weight of the second binder.

[0082] As a specific example, the aerogel composition may contain 45% to 55% by weight of aerogel, 25% to 45.5% by weight of the first binder, and 4.5% to 25% by weight of the second binder, relative to the total solid content of the aerogel composition. When the aerogel composition is formulated within the above ranges, excellent heat insulation properties are achieved and heat resistance is improved, thereby blocking heat transfer between cells.

[0083] In one embodiment, the aerogel composition may contain, relative to the total solid content of the aerogel composition, 40 wt % to 60 wt % aerogel, 10 wt % to 50 wt % first binder, 1 wt % to 45 wt % second binder, and 0.1 wt % to 5 wt % dispersant.

[0084] As a specific example, the aerogel composition may contain, relative to the total solid content of the aerogel composition, 45% to 55% by weight of aerogel, 25% to 45.5% by weight of the first binder, 4.5% to 25% by weight of the second binder, and 0.1% to 5% by weight of the dispersant. When the aerogel composition is formulated within the above ranges, the dispersibility of the aerogel is improved, achieving excellent thermal insulation and improving heat resistance, thereby more effectively blocking heat transfer between cells.

[0085] In one embodiment, the aerogel composition may contain, relative to the total solid content of the aerogel composition, 40 wt % to 60 wt % aerogel, 10 wt % to 50 wt % first binder, 1 wt % to 45 wt % second binder, 0.1 wt % to 5 wt % dispersant, and 0.1 wt % to 8 wt % flame retardant.

[0086] As a specific example, the aerogel composition may contain, relative to the total solid content of the aerogel composition, 45% to 55% by weight of aerogel, 25% to 45.5% by weight of the first binder, 4.5% to 25% by weight of the second binder, 0.1% to 5% by weight of the dispersant, and 0.1% to 8% by weight of the flame retardant. When the aerogel composition is formulated within the above ranges, the dispersibility of the aerogel is improved, achieving excellent thermal insulation while also improving heat resistance and fire resistance, thereby more effectively blocking heat transfer between cells.

[0087] In one embodiment, the aerogel composition may further include a silane-based compound. The silane-based compound may include, for example, one or more compounds selected from the group consisting of 3-(trimethoxysilyl)propylmethacrylate, methyltriethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, octadecyltrimethoxysilane, ethyltriethoxysilane, and 3-glycidoxypropyltrimethoxysilane. The inclusion of a silane-based compound may further improve dispersibility.

[0088] In one embodiment, the composition may further optionally contain additives such as wetting agents, emulsifiers, compatibilizers, viscosity adjusters, 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.

[0089] According to one embodiment, a method for manufacturing an aerogel composition includes: mixing a functional material including a binder or a binder and a dispersant with a solvent to prepare a solvent mixture; and mixing the solvent mixture with an aerogel to prepare an aerogel composition. The binder may include a first binder including a water-based polymer binder and a second binder including a fluorocarbon-based binder.

[0090] In the step of preparing the solvent mixture by mixing the functional material with the solvent, the first binder and the second binder may be mixed as the functional material with the solvent, or the first binder, the second binder, and the dispersant may be mixed as the functional material with the solvent. Here, the specific description of the solvent, the binder, and the dispersant may be as described above.

[0091] In the step of preparing the solvent mixture by mixing the functional material with the solvent, a flame retardant containing a phosphate-based ammonium salt may be further added. Here, the specific description regarding the flame retardant may be the same as that described above.

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

[0093] In each of the steps of preparing a solvent mixture by mixing a functional material including a binder or a binder and a dispersant with a solvent and preparing an aerogel composition by mixing the solvent mixture with an aerogel, 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.

[0094] As a specific example, a planetary mixer can be used to mix the solvent mixture and the aerogel. By using a planetary mixer to mix the solvent mixture and the aerogel, the aerogel can be uniformly dispersed in the solvent.

[0095] A planetary mixer may be a device that can be used to mix or stir different materials to produce a homogeneous mixture. It may include blades that can move in planetary motion.

[0096] In one embodiment, the planetary mixer can include one or more of one or more planetary blades and one or more high-speed dispersion blades. As a specific example, the planetary mixer can include one or more planetary blades and one or more high-speed dispersion blades.

[0097] The planetary blades and high-speed dispersion blades rotate continuously about their axes, and the rotational speed may be expressed in units of rotations per minute (rpm).

[0098] In one embodiment, the planetary mixer may include a first blade and a second blade having different rotation axes. For example, the first blade may be a low-speed blade and the second blade may be a high-speed blade. Here, low speed and high speed refer to the relative rotation speeds of the first blade and the second blade. As a specific example, the first blade may be an open blade and the second blade may be a Despa blade.

[0099] 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.

[0100] When the functional material is added to the solvent and mixed, 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, 600 rpm to 1000 rpm, or 700 rpm to 800 rpm. By mixing the solvent and functional material as described above, a solvent mixture in which the binder or the binder and dispersant are uniformly dispersed is produced, making it easier to mix the aerogel in the subsequent step.

[0101] When mixing the solvent mixture and 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.

[0102] A battery insulation sheet according to one embodiment includes a first substrate, a second substrate, and an aerogel layer formed between the first substrate and the second substrate, and the aerogel layer may be formed using the aerogel composition described above.

[0103] FIG. 1 is a schematic diagram showing the structure of a battery insulation sheet according to one embodiment.

[0104] 1 , in one embodiment, a battery insulation sheet 100 may have a structure including a first substrate 110, an aerogel layer 120 formed on the first substrate 110, and a second substrate 130 formed on the aerogel layer 120. Here, the first substrate 110 and the second substrate 130 may be disposed to face the adjacent cell. In this case, the first substrate 110 and the second substrate 130 may be formed of the same or different materials.

[0105] By forming the aerogel layer 120 between the first substrate 110 and the second substrate 130 using an aerogel composition according to one embodiment, the battery insulation sheet 100 has improved durability as well as thermal insulation properties, and can block heat transfer between cells due to its excellent heat resistance.

[0106] In the battery insulation sheet 100, the specific description of the aerogel composition forming the aerogel layer 120 can be as described above.

[0107] The first substrate 110 and the second substrate 130 may be made of various materials, such as resin, metal, inorganic material other than metal, or a composite thereof, and are not limited to a specific type. The form of the substrate may be a film, thin film, sheet, or the like, and is not particularly limited to a specific form.

[0108] The resin may include, for example, one or more selected from the group consisting of polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and polyamide.

[0109] 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 a metal substrate is used, the substrate may be subjected to corrosion prevention treatment, insulation treatment, etc., as necessary.

[0110] The inorganic material may include one or more selected from the group consisting of calcium carbonate (CaCO3), talc, and mica.

[0111] As a specific example, each of the first substrate 110 and the second substrate 130 may include an inorganic material, and more specifically, may include mica, which may improve the thermal insulation properties and durability of the heat insulating sheet.

[0112] In one embodiment, the aerogel layer 120 may be formed in a single layer structure or a multi-layer structure. When the aerogel layer 120 is formed in a multi-layer structure, the aerogel layer 120 may be formed in 2 to 10 layers, 2 to 7 layers, or 2 to 5 layers.

[0113] A method for manufacturing the battery insulation sheet 100 according to one embodiment may include the steps of applying an aerogel composition to a first substrate 110, laminating a second substrate 130 on the applied aerogel composition to form a laminate, pressing the laminate, and drying the laminate.

[0114] In the method for manufacturing the battery insulation sheet, the first substrate 110 and the second substrate 130 may be specifically described above.

[0115] In the step of applying the aerogel composition onto the first substrate 110, the aerogel composition can be applied directly onto the first substrate 110.

[0116] The step of applying the aerogel composition onto the first substrate 110 may be carried out in the same manner as applying a slurry onto a conventional substrate.

[0117] The step of applying the aerogel composition onto the first substrate 110 may be repeated once or twice or more times.

[0118] In one embodiment, an aerogel composition is applied to a first substrate 110, and a second substrate 130 is then laminated on the applied aerogel composition to form a structure in which the first substrate 110, the aerogel layer 120, and the second substrate 130 are sequentially laminated.

[0119] In one embodiment, the step of pressing the laminate may be carried out by a conventional pressing method.

[0120] In one embodiment, in the step of drying the laminate, the drying 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. By drying at such a temperature condition, it is possible to form a robust aerogel layer on the substrate without a separate adhesive member or adhesive, while preventing detachment of the aerogel layer 120 from the first substrate 110 and the second substrate 130.

[0121] In one embodiment, the steps of pressing the laminate and drying the laminate may be performed in separate steps or may be performed simultaneously.

[0122] A battery module according to one embodiment includes a plurality of cells and battery insulation sheets 100 respectively provided between the plurality of cells, and the first substrate 110 and the second substrate 130 may each be arranged to face the adjacent cell.

[0123] FIG. 2 is a schematic diagram showing a battery insulation sheet 100 according to an embodiment formed between a plurality of cells.

[0124] 2, 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, one side of the battery insulation sheet 100 on which the first substrate 110 is formed and the other side on which the second substrate 130 is formed 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, it is possible to first block a flame inside the cell and minimize the spread of the flame to other cells, thereby providing a battery module and a battery pack including the same with improved safety. [Example]

[0125] Specific examples of the present invention will be presented below. However, the examples described below are merely for the purpose of specifically illustrating or explaining the present invention, and the present invention should not be limited thereto. Furthermore, since the contents not described here can be sufficiently inferred by those skilled in the art, a description thereof will be omitted.

[0126] (battery insulation sheet manufacturing) Example 1 1. Aerogel Composition Preparation Polyvinyl alcohol (Sigma Aldrich, Poly(vinyl alcohol)) as the first binder and polytetrafluoroethylene as the second binder were added to ultrapure water as the solvent, and then mixed under the conditions of an open blade of 30 rpm and a Despa blade of 700 rpm to prepare a solvent mixture. 2 After adding the aerogel (1 / g), the mixture was mixed at an open blade speed of 70 rpm and a Desper blade speed of 1500 rpm using a planetary mixer (DN Tech, PT-005) to prepare an aerogel composition.

[0127] The solid content of the prepared aerogel composition was confirmed to be 50 wt% aerogel, 45.5 wt% polyvinyl alcohol, and 4.5 wt% polytetrafluoroethylene.

[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 coated using a roll rolling method. The aerogel layer was then formed by drying at 60°C for 24 hours, producing a battery insulation sheet. The total thickness of the battery insulation sheet was confirmed to be 1.38 mm.

[0129] Example 2 The aerogel composition was prepared in the same manner as in Example 1, except that the amounts of raw materials added during the preparation of the aerogel composition were adjusted to prepare an aerogel composition with a solid content of 50 wt % aerogel, 41.7 wt % polyvinyl alcohol, and 8.3 wt % polytetrafluoroethylene.

[0130] Example 3 The same method as in Example 1 was used to prepare the aerogel composition, except that the amounts of raw materials added were adjusted to prepare an aerogel composition with a solid content of 50 wt % aerogel, 35.7 wt % polyvinyl alcohol, and 14.3 wt % polytetrafluoroethylene.

[0131] Example 4 The aerogel composition was prepared in the same manner as in Example 1, except that the amounts of raw materials added during the preparation of the aerogel composition were adjusted to prepare an aerogel composition with a solid content of 50 wt % aerogel, 25 wt % polyvinyl alcohol, and 25 wt % polytetrafluoroethylene.

[0132] Example 5 The aerogel composition was prepared in the same manner as in Example 1, except that the amounts of raw materials added during the preparation of the aerogel composition were adjusted to prepare an aerogel composition with a solid content of 50 wt % aerogel, 47.6 wt % polyvinyl alcohol, and 2.4 wt % polytetrafluoroethylene.

[0133] Example 6 The aerogel composition was prepared in the same manner as in Example 1, except that the amounts of raw materials added during the preparation of the aerogel composition were adjusted to prepare an aerogel composition with a solid content of 50 wt % aerogel, 10 wt % polyvinyl alcohol, and 40 wt % polytetrafluoroethylene. In this case, the dispersibility of the aerogel was reduced, making it difficult to prepare a heat insulating sheet.

[0134] Example 7 The same method as in Example 1 was used to prepare the composite material, except that polyurethane was used instead of polyvinyl alcohol as the first binder, and polyvinylidene fluoride (PVDF) was used instead of polytetrafluoroethylene as the second binder.

[0135] Example 8 1. Aerogel Composition Preparation Polyvinyl alcohol (Sigma Aldrich, Poly(vinyl alcohol)) as the first binder, polytetrafluoroethylene as the second binder, and a surfactant (Triton-X100, Sigma Aldrich) as a dispersant were added to ultrapure water as a solvent, and then mixed with an open blade at 30 rpm and a desparate blade at 700 rpm to produce a solvent mixture. 2 After adding the aerogel (1 / g), the mixture was mixed at an open blade speed of 70 rpm and a Desper blade speed of 1500 rpm using a planetary mixer (DN Tech, PT-005) to prepare an aerogel composition.

[0136] The solids content of the prepared aerogel composition was determined to be 50 wt % aerogel, 45.5 wt % polyvinyl alcohol, 4.0 wt % polytetrafluoroethylene, and 0.5 wt % dispersant.

[0137] 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 coated using a roll rolling method. The aerogel layer was then formed by drying at 60°C for 24 hours, producing a battery insulation sheet. The total thickness of the battery insulation sheet was confirmed to be 1.38 mm.

[0138] Example 9 1. Aerogel Composition Preparation Polyvinyl alcohol (Sigma Aldrich, Poly(vinyl alcohol)) as the first binder, polytetrafluoroethylene as the second binder, surfactant (Triton-X100, Sigma Aldrich) as a dispersant, and anhydrous ammonium phosphate (Sigma Aldrich, 7722-76-1) as a phosphorus-based material were added to ultrapure water as a solvent, and then mixed with an open blade at 30 rpm and a despa blade at 700 rpm to produce a solvent mixture. 2 After adding the aerogel (1 / g), the mixture was mixed at an open blade speed of 70 rpm and a Desper blade speed of 1500 rpm using a planetary mixer (DN Tech, PT-005) to prepare an aerogel composition.

[0139] The solids content of the prepared aerogel composition was determined to be 50 wt% aerogel, 45.25 wt% polyvinyl alcohol, 4.0 wt% polytetrafluoroethylene, 0.5 wt% dispersant, and 0.25 wt% anhydrous ammonium phosphate.

[0140] 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 coated using a roll rolling method. The aerogel layer was then formed by drying at 60°C for 24 hours, producing a battery insulation sheet. The total thickness of the battery insulation sheet was confirmed to be 1.38 mm.

[0141] Comparative Example 1 The aerogel composition was prepared in the same manner as in Example 1, except that the amounts of raw materials added during the preparation of the aerogel composition were adjusted to prepare an aerogel composition with a solid content of 50 wt % aerogel and 50 wt % polyvinyl alcohol.

[0142] Comparative Example 2 The same method as in Example 1 was used to prepare an aerogel composition, except that the amounts of raw materials added were adjusted to prepare an aerogel composition with a solid content of 50 wt % aerogel and 50 wt % polytetrafluoroethylene. In this case, a heat insulating sheet could not be prepared due to the difficulty in dispersion.

[0143] (Experimental example) Experimental example 1: Heat insulation evaluation The heat insulating properties were evaluated using the heat insulating sheets manufactured in the examples and comparative examples. Specifically, each heat insulating sheet was placed 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 the starting 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, as shown in Table 1 below.

[0144] Experimental example 2: Dust evaluation The dust resistance of the heat insulating sheets manufactured in the above examples and comparative examples was evaluated by the following method. Dust resistance test: Using a vibration tester (ASTMC592-04), measure the weight loss rate due to vibration under vibration conditions of 24Hz / 3mm, 6 hours - Sample preparation: Prepare a 12 x 12 inch insulation sheet. - Weight reduction rate [%] = [(weight of the insulation sheet before evaluation) - (weight of the insulation sheet after evaluation)] / (weight of the insulation sheet before evaluation) x 100

[0145] [Table 1]

[0146] Referring to Table 1 above, Examples 1 to 5 confirm the change in heat insulating properties depending on the component content of the aerogel composition, and it was confirmed that when the weight ratio of the first binder to the second binder was adjusted to 1:1 to 10:1, the heat insulating properties were very excellent. Furthermore, Examples 1 and 7 confirm the heat insulating properties depending on the type of the first binder and the second binder. Furthermore, Example 8 confirms that dust resistance was improved when the binder and dispersant were mixed. Furthermore, Example 9 confirms that heat insulating properties and dust resistance were further improved when polyvinyl alcohol and a flame retardant were included.

[0147] On the other hand, it was confirmed that the heat insulating properties were significantly reduced in Comparative Example 1, which did not contain a second binder, and that the heat insulating properties were significantly reduced in Comparative Example 2, which did not contain a first binder, and that a heat insulating sheet was not produced due to reduced dispersibility.

[0148] Therefore, it was confirmed that the aerogel composition according to one embodiment has excellent heat insulating properties and heat propagation blocking properties.

[0149] Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made within the scope of the claims, the detailed description of the invention, and the accompanying drawings, and it is to be understood that these modifications also fall within the scope of the present invention. [Explanation of symbols]

[0150] 100 Battery Heat Insulation Sheet 110 First base material 120 aerogel layer 130 Second base material 200 cells

Claims

1. Aerogel and a functional material containing a binder or the binder and a dispersant; a solvent, The aerogel composition for a battery insulation sheet, wherein the binder comprises a first binder including a water-based polymer binder and a second binder including a fluorocarbon-based binder.

2. The aerogel has a BET specific surface area of ​​500 m ２ / g to 1,000m ２ 2. The aerogel composition for a battery insulating sheet according to claim 1, wherein the aerogel composition has a viscosity of 1000 MPa or less.

3. The aerogel and the functional substance are contained as solid components of the aerogel composition for battery insulation sheets, 2. The aerogel composition for a battery insulation sheet according to claim 1, wherein the content of the aerogel is 30 wt % to 70 wt % based on the total solid content of the aerogel composition for a battery insulation sheet.

4. 2. The aerogel composition for a battery insulation sheet according to claim 1, wherein the aqueous polymer binder comprises at least one selected from the group consisting of an aqueous polymer, an anionic water-soluble polymer, a cationic water-soluble polymer, and a water-dispersible polymer.

5. 2. The aerogel composition for a battery insulation sheet according to claim 1, wherein the fluorocarbon binder comprises at least one selected from the group consisting of polytetrafluoroethylene, polyvinylidene fluoride, and polyvinylidene fluoride-hexapropylene copolymer.

6. 2. The aerogel composition for a battery insulation sheet according to claim 1, wherein the first binder and the second binder are contained in a weight ratio of 0.1:1 to 20:

1.

7. When the functional substance contains the dispersant, 2. The aerogel composition for a battery insulation sheet according to claim 1, wherein the dispersant comprises at least one selected from the group consisting of a surfactant and a phosphate salt.

8. The aerogel and the functional substance are contained as solid components of the aerogel composition for battery insulation sheets, 2. The aerogel composition for a battery insulation sheet according to claim 1, wherein the content of the functional material is 30 wt % to 70 wt % based on the total solid content of the aerogel composition for a battery insulation sheet.

9. 2. The aerogel composition for a battery insulation sheet according to claim 1, wherein the solvent comprises at least one selected from the group consisting of polar solvents and non-polar solvents.

10. The aerogel and the functional substance are contained as solid components of the aerogel composition for battery insulation sheets, 2. The aerogel composition for battery insulation sheets according to claim 1, wherein a weight ratio of the solvent to a total amount of solids in the aerogel composition for battery insulation sheets is 1:1 to 1:

90.

11. The aerogel composition for a battery insulation sheet according to claim 1, further comprising a flame retardant containing a phosphorus-based material.

12. 12. The aerogel composition for a battery insulation sheet according to claim 11, wherein the phosphorus-based material comprises at least one of a phosphate-based ammonium salt, red phosphorus, and compounds represented by the following formulas (1) and (2): 【Chemical Formula 1】 In formula (1), Ar １ ~Ar ３ are each independently substituted or unsubstituted C ６ ~C ２０ is an aryl group, 【Chemistry 2】 In formula (2), Ar ４ ~Ar １０ are each independently substituted or unsubstituted C ６ ~C ２０ It is an aryl group.

13. The aerogel composition for battery insulation sheets as described in claim 11, wherein the content of the flame retardant is 0.1 to 20 parts by weight when the functional substance is 100 parts by weight.

14. The aerogel and the functional substance are contained as solid components of the aerogel composition for battery insulation sheets, 2. The aerogel composition for a battery insulation sheet according to claim 1, wherein the aerogel content is 40 wt % to 60 wt %, the first binder content is 10 wt % to 50 wt %, and the second binder content is 1 wt % to 45 wt %, relative to a total solid content of the aerogel composition for a battery insulation sheet.

15. The aerogel and the functional substance are contained as solid components of the aerogel composition for battery insulation sheets, When the functional substance contains the dispersant, 2. The aerogel composition for a battery insulation sheet according to claim 1, wherein the aerogel content is 40 wt % to 60 wt %, the first binder content is 10 wt % to 50 wt %, the second binder content is 1 wt % to 45 wt %, and the dispersant content is 0.1 wt % to 5 wt %, relative to a total solid content of the aerogel composition for a battery insulation sheet.

16. The aerogel and the functional substance are contained as solid components of the aerogel composition for battery insulation sheets, When the functional substance contains the dispersant, 12. The aerogel composition for a battery insulation sheet according to claim 11, wherein the aerogel content is 40 wt % to 60 wt %, the first binder content is 10 wt % to 50 wt %, the second binder content is 1 wt % to 45 wt %, the dispersant content is 0.1 wt % to 5 wt %, and the flame retardant content is 0.1 wt % to 8 wt %, relative to a total solid content of the aerogel composition for a battery insulation sheet.

17. preparing a solvent mixture by mixing a binder or a functional material including the binder and a dispersant into a solvent; and mixing the solvent mixture and an aerogel to prepare an aerogel composition; The method for producing an aerogel composition for a battery insulation sheet, wherein the binder comprises a first binder including a water-based polymer binder and a second binder including a fluorocarbon-based binder.

18. A first substrate; A second substrate; an aerogel layer formed between the first substrate and the second substrate, The aerogel layer is formed using the aerogel composition for battery insulation sheets according to any one of claims 1 to 16.

19. A plurality of cells; and the battery insulating sheet according to claim 18, which is disposed between the plurality of cells, The first substrate and the second substrate are each arranged to face an adjacent cell.

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