Flexible insulating material

Abstract

A flexible insulating member is described. This insulating member may be a single layer, or it may include a first layer having an aerogel and a first fibrous component, and a second layer which is a mat having a second fibrous component. The first and second layers are bonded to each other. The flexible insulating member is flame retardant according to UL94 V0, has a thermal conductivity of less than 40 mW / m·K at 25°C, and has a thickness of at least 0.3 mm. A method for manufacturing this insulating member, along with its use, is described further.

Description

[Technical Field]

[0001] The present invention relates to the use of aerogel in products and methods for manufacturing them. More specifically, the present invention relates to a flexible insulating member, which may be a single-layer or multi-layer flexible insulating member such as a blanket, that utilizes aerogel in at least a portion of the insulating member.

[0002] Aerogel particles can have very low density, high porosity, and small pore size. Aerogels, especially silica aerogels, are useful as insulating materials due to their low density and low thermal conductivity. Aerogels can be formed by removing solvents from hydrogels, such as by supercritical drying techniques or by solvent substitution combined with atmospheric pressure drying. Silica aerogels are typically hydrophilic, but can be made hydrophobic by the use of specific treatment agents.

[0003] In its broadest sense, that is, "a gel having air as a dispersion medium," aerogels are produced by drying a suitable gel. When used in this sense, the term "aerogel" includes aerogels in the narrow sense, such as xerogels and cryogels. If the temperature at which the liquid is removed from the gel is higher than the critical temperature and the pressure is higher than the critical pressure, the gel is called an aerogel in the narrow sense. In contrast, if the liquid is removed from the gel below critical, for example, with the formation of a gas-liquid interface phase, the resulting gel is often called a xerogel. It should be noted that the gel according to the present invention is an aerogel in the sense that it is a gel having air as a dispersion medium.

[0004] Due to its excellent insulating properties, aerogels are incorporated into a variety of articles, including thermal control components (e.g., sheets, pads, or blankets) designed for applications such as construction, cooling, and pipe transport. One application of growing interest is in insulating rechargeable batteries in electric vehicles (EVs).

[0005] The automotive industry is shifting from conventional internal combustion engine (ICE) powertrains to battery-electric vehicles (EVs) to reduce greenhouse gas emissions. EVs utilize electrochemical energy storage systems or batteries instead of burning fossil fuels (gasoline or diesel) as an energy source. The most commonly used technology for EV batteries is lithium-ion chemistry, which typically consists of a cathode and anode separated by a separator and electrolyte. Lithium-ion batteries offer a good balance of energy density, power density, and cycle life, making them the most suitable system for powering EVs. However, lithium-ion batteries can experience thermal runaway under abused conditions, which can cause the battery to ignite or explode, thus endangering the lives of occupants. Regulatory standards already in place for EVs, such as GTR20, mandate that in the event of thermal runaway, the vehicle must provide a warning or escape time at least five minutes before a dangerous situation arises inside the vehicle.

[0006] Many technological avenues have been pursued, from the cell level to the pack level and the automobile level, to prevent or reduce the risk of thermal runaway. When a thermal runaway event occurs, heat is released from the cell experiencing the event. Alternatively, a thermal runaway event may propagate to adjacent cells, causing so-called thermal runaway propagation, which can escalate the risk.

[0007] Therefore, one effective solution to address this risk is to install a thermal barrier between battery cells to reduce thermal runaway propagation from the source cell to adjacent cells. The thermal barrier may be an aerogel / glass fiber blanket, ceramic paper, or silicone foam with a thermal conductivity in the range of 15–100 mW / m·K at room temperature. Lower thermal conductivity is always desirable as it further reduces heat transfer by conduction between the high-temperature source cell and the lower-temperature adjacent cells.

[0008] Silica-based aerogel particle products are excellent thermal insulation additives and can be used in a variety of product forms, including paper, coatings, plaster, boards, and blankets, and can be used in a wide range of industrial applications. Silica aerogel is lightweight and a good insulating solid. With a thermal conductivity of approximately 10-45 mW / m·K at room temperature, silica aerogel is considered the only solid material that has better insulating properties than still air.

[0009] However, even considering the above, one challenge in the industry is providing products that are thin enough for applications such as thermal barriers for battery cells. However, thinness comes with a potential undesirable decrease in thermal and / or flame properties. Furthermore, manufacturing thin products presents many challenges, particularly in wet-laid formation processes.

[0010] Therefore, there is a need to provide a flexible insulating member that has the minimum overall thickness but can be manufactured to achieve desirable properties as a thermal barrier for various applications, particularly as a thermal barrier for electric vehicle battery cells. [Overview of the project]

[0011] The feature of the present invention is to provide a thermal barrier useful for applications such as thermal barriers for vehicle battery cells.

[0012] A further feature of the present invention is to provide a thermal barrier that can be made thin while maintaining desirable thermal barrier properties.

[0013] A further feature of the present invention is to provide a thermal barrier that can be flexible and can be fabricated by a wet-laid process.

[0014] Furthermore, a key feature of the present invention is to provide a flexible thermal barrier that is flame-retardant and preferably maintains thermal barrier properties.

[0015] Further features and advantages of the present invention are partially described in the following description, some of which will become apparent from the description or may be acquired through the practice of the invention. The objectives and other advantages of the present invention are realized and achieved by the elements and combinations specifically pointed out in the specification and appended claims.

[0016] To achieve these and other advantages, and in accordance with the objectives of the present invention, the present invention relates to a flexible insulating member comprising a mat layer, as embodied and broadly described herein. The mat comprises at least a second fibrous component. A preformed aerogel is dispersed in the mat or otherwise present. The mat layer also has a first fibrous component dispersed in the mat. The flexible insulating member is flame retardant according to UL94 V0, has a thermal conductivity of less than 40 mW / m·K at 25°C, and has a thickness of at least 0.3 mm.

[0017] The present invention further relates to a multilayer flexible insulating member. The insulating member comprises a first layer and a second layer. The first layer comprises an aerogel and a first fibrous component, and the second layer comprises a mat comprising at least a second fibrous component. The first and second layers are bonded together to form a multilayer member. The multilayer flexible insulating member is flame retardant according to UL94 V0, has a thermal conductivity of less than 40 mW / m·K at 25°C, and has a thickness of at least 0.3 mm.

[0018] The present invention further relates to a method for producing a multilayer flexible insulating member of the present invention. This method includes forming a wet-laid layer (i.e., a first layer) on a second layer, and then drying the multilayer member.

[0019] It should be understood that both the general description above and the detailed description below are merely illustrative and descriptive, and are intended to provide a further explanation of the claimed invention.

[0020] The accompanying drawings incorporated in this application and constituting a part of this application illustrate some embodiments of the present invention and, together with the description, serve to explain the principles of the present invention.

Brief Description of the Drawings

[0021] [Figure 1] It is an enlarged side view of an embodiment of the flexible insulating member of the present invention, which is multilayered and has a slight engagement or mixing between the first layer and the second layer.

[0022] [Figure 2] It is an enlarged side view of another embodiment of the flexible insulating member of the present invention, which is multilayered and has more engagement or mixing (approximately 10% - 50%) between the first layer and the second layer so as to define an area of engagement or penetration.

[0023] [Figure 3] It is an enlarged side view of another embodiment of the flexible insulating member of the present invention, which is multilayered and has even more engagement or mixing (approximately 50% - 90%) between the first layer and the second layer so as to define an area of engagement or penetration.

[0024] [Figure 4] It is an enlarged side view of a further embodiment of the flexible insulating member of the present invention, which is single - layer and in which the aerogel and the first fibrous component are completely engaged, or embedded, or penetrated in the upper part of the mat.

[0025] [Figure 5] It is an enlarged side view of a further embodiment of the flexible insulating member of the present invention, which is single - layer and in which the aerogel and the first fibrous component are completely engaged, or embedded, or penetrated substantially throughout the thickness of the mat.

Modes for Carrying Out the Invention

[0026] The present invention relates to an insulating member containing an aerogel, such as aerogel particles. The present invention further relates to a flexible insulating member containing an aerogel. Furthermore, the present invention relates to a multilayer flexible insulating member containing an aerogel in at least one of its layers. Methods for producing the insulating member, along with the use of the insulating member, are further described herein.

[0027] Therefore, at least one aspect of the present invention specifically relates to a single-layer insulating member. The single layer is referred to herein as a “mat,” but the flexible insulating member may be, for example, a blanket, sheet, pad, mat, etc.

[0028] At least one further aspect of the present invention specifically relates to a multilayer insulating member in which the second layer is called a “mat,” but it is understood that in any embodiment of the present invention, this second layer and, in practice, the entire flexible insulating member may be, for example, a blanket, sheet, pad, mat, etc.

[0029] Furthermore, at least one aspect of the present invention, therefore, specifically relates to a multilayer flexible insulating member. The multilayer flexible insulating member may be, for example, a blanket, sheet, pad, mat, etc.

[0030] The insulating member comprises, essentially consists of, comprises, or includes at least a first layer or single layer. Optionally, the insulating member comprises only the first layer and does not include any other additional layers (i.e., a single-layer flexible insulating member).

[0031] Alternatively, the insulating member may comprise, be essentially composed of, consist of, or include at least a first and a second layer. The insulating member may optionally consist only of the first and second layers and not any other additional layers (i.e., a two-layer flexible insulating member).

[0032] As shown, as one option, the present invention relates to a flexible insulating member comprising a mat layer (e.g., a single layer). The mat comprises at least a second fibrous component and a pre-formed aerogel. The mat layer also has a first fibrous component dispersed in the mat. The flexible insulating member is flame retardant according to UL94 V0, has a thermal conductivity of less than 40 mW / m·K at 25°C, and has a thickness of at least 0.3 mm.

[0033] The flexible insulating member further has a thickness of at least 0.3 mm. This may be the average thickness, or it may be the maximum thickness. The thickness may be at least 0.4 mm or at least 0.5 mm. The thickness may be 0.3 mm to 10 mm, or 0.3 mm to 9 mm, or 0.3 mm to 8 mm, or 0.3 mm to 7 mm, or 0.3 mm to 6 mm, or 0.3 mm to 5 mm, or 0.3 mm to 4 mm, or 0.3 mm to 3 mm, or 0.3 mm to 2 mm, or 0.4 mm to 10 mm, or 0.5 mm to 10 mm, or 0.6 mm to 10 mm, or 0.3 mm to 1.5 mm, or 0.5 mm to 1.5 mm or more. The thickness may be 0.5 mm to 1.25 mm, 0.5 mm to 1 mm, or 0.5 mm to 0.75 mm. The thickness may be greater than 1.5 mm (e.g., 1.5 mm to 5 mm or 1.5 mm to 10 mm) in certain applications, as needed. Preferably, in a particular application, the overall average thickness of the multilayer flexible insulating material is less than 1.5 mm, less than 1.25 mm, less than 1 mm, less than 0.75 mm, less than 0.5 mm, or any range based on any two values ​​described herein.

[0034] Examples of the flexible insulating member of the present invention include, but are not limited to, blankets, mats, pads, or sheets, or other articles.

[0035] The mat can be considered a fibrous mat or a fibrous mat. For the purposes of the present invention, the mat can be considered a mat or a cloth. A “fibrous mat” is considered a ply of chopped (short and / or long) yarns / fibers held together by a binder and / or stitching. A “fibrous cloth” is considered a ply of continuous yarns / fibers manufactured by lamination techniques such as weaving or knitting. For the purposes of the present invention, a “mat containing a second fibrous component” may be either a fibrous mat or a fibrous cloth. The mat preferably meets the UL-94 V0 flame retardancy rating itself.

[0036] Examples of mats include, but are not limited to, chopped strand mats, continuous filament random mats, bale mats, continuous strand fiber mats, continuous strand bale surface mats, woven mats, and non-crimped cloth mats. The mat may be a mycalamine laminate paper layer, a rock wool layer, a slag wool layer, an alumina silica layer, a graphite fiber layer, a mineral wool fiber layer, a silicone rubber sheet layer, a silica fiber layer, a glass fiber layer, a carbon fiber layer, an e-glass cloth silicon coated ceramic paper layer, an aerogel mat layer, a polyamide paper layer, or any combination thereof, or may include them. One preferred mat may be, for example, a fiberglass mat.

[0037] The mat may be a medium-density fiber mat. The mat may be a high-density fiber mat. The second layer may be a woven or non-woven fabric layer.

[0038] The mat may be considered to be a woven mat or a non-woven mat, or may include both.

[0039] Examples of commercially available mats that can be used include, but are not limited to, FIBREGLAST mats (e.g., FIBREGLAST 260 mats) or other continuous strand bale surface mats or continuous strand mats such as fiberglass mats.

[0040] The mat itself (before the pre-formed aerogel and the first fibrous components are dispersed in the mat) may be porous and / or have random openings or voids. The pores or openings or voids may comprise at least 5% of the total volume of the second layer, such as at least 10%, at least 15%, or 5% to 20% of the total volume of the mat.

[0041] Details of the aerogel and the first fibrous component, as well as details of any optional component, are described below in detail for the multilayer insulating member and apply equally to this embodiment.

[0042] Regarding the single-layer flexible insulating material, the aerogel is pre-formed before being dispersed in the mat, rather than being formed in situ on the mat. As a result, the aerogel particles largely maintain their shape and size while dispersed in the mat.

[0043] When aerogel particles are dispersed in a mat, they can be considered to be unevenly dispersed throughout the mat. In other words, the distribution of aerogel particles across the mat is not uniform and can differ between different sections of the mat. Therefore, one section of the mat may have an aerogel density that differs by at least 5%, at least 10%, at least 15%, at least 20%, or at least 25% or more compared to other sections of the same mat.

[0044] When aerogel particles are dispersed in the mat, and because the aerogel particles are pre-formed before dispersion, they preferably do not coat the fibers present in the mat. When comparing in-situ aerogel particles with pre-formed aerogel particles, the average particle size or D10 or D90 diameter distribution of the pre-formed aerogel particles can usually be quite different. For example, the D90 value of pre-formed aerogel particles in the mat may be at least 10%, at least 20%, or at least 30% higher than that of in-situ aerogel particles.

[0045] In this embodiment having a single layer, the dispersion of the aerogel and the first fibrous component can be carried out by casting or pouring or otherwise dispersing a slurry of the aerogel and the first fibrous component (i.e., the slurry is preferably aggregated), which at least partially fills or occupies the voids, openings, or pores present in the mat. This can optionally be further characterized as follows: The flexible insulating member is such that the mat has thickness and pores throughout the entire thickness, and the aerogel and the first fibrous component fill / occupy at least 50% of the pores over at least 90% of the thickness of the mat.

[0046] The flexible insulating member may further or alternatively be characterized in that the mat (dry) itself is permeable, the preformed aerogel and the first fibrous component are dispersed in the mat, and after the member is dried, the permeability is reduced by at least 50%. The reduction may be at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or 50% to 90%, such as 50% to 99%.

[0047] Optionally, in the flexible insulating member, the preformed aerogel and the first fibrous component may be completely dispersed below the top surface of the mat. Therefore, when observing the exposed top surface of the mat, the aerogel and the first fibrous component are either not visible or occupy less than 20% (e.g., less than 15%, less than 10%, less than 5%, less than 1%) of the exposed top surface of the cross-section of the mat.

[0048] In further embodiments of the present invention, a multilayer insulating member is described in more detail.

[0049] The first layer comprises, essentially consists of, comprises, or includes aerogel and a first fibrous component. The first layer can be produced by wet-laid technology from a composition (e.g., slurry) containing aerogel particles and the first fibrous component together with one or more other materials of any choice.

[0050] The second layer comprises, is essentially, consists of, or includes a mat. The mat comprises, is essentially, consists of, or includes a second fibrous component.

[0051] In the multilayer flexible insulating member of the present invention, the first layer and the second layer are bonded together.

[0052] Flexible insulating material (e.g., single-layer flexible insulating material or multi-layer flexible insulating material) is further flame-retardant in accordance with UL94 V0 (i.e., meets or satisfies UL94 V0).

[0053] Flexible insulating material (e.g., single-layer flexible insulating material or multi-layer flexible insulating material) further has a thermal conductivity at 25°C of less than 40 mW / m·K. The thermal conductivity at 25°C may be less than 35 mW / m·K, or less than 30 mW / m·K, or less than 25 mW / m·K, or less than 20 mW / m, or less than 15 mW / m·K, or less than 10 mW / m·K, or between 1 mW / m·K and 39 mW / m·K, or any range based on any two values ​​described herein.

[0054] The multilayer flexible insulating member further has a thickness of at least 0.3 mm. This may be the average thickness. The thickness may be at least 0.4 mm or at least 0.5 mm. The thickness may be 0.3 mm to 10 mm, or 0.3 mm to 9 mm, or 0.3 mm to 8 mm, or 0.3 mm to 7 mm, or 0.3 mm to 6 mm, or 0.3 mm to 5 mm, or 0.3 mm to 4 mm, or 0.3 mm to 3 mm, or 0.3 mm to 2 mm, or 0.4 mm to 10 mm, or 0.5 mm to 10 mm, or 0.6 mm to 10 mm, or 0.3 mm to 1.5 mm, or 0.5 mm to 1.5 mm or more. The thickness may be 0.5 mm to 1.25 mm, 0.5 mm to 1 mm, or 0.5 mm to 0.75 mm. The thickness may be greater than 1.5 mm (e.g., 1.5 mm to 5 mm or 1.5 mm to 10 mm) in certain applications, as needed. Preferably, in a particular application, the overall average thickness of the multilayer flexible insulating material is less than 1.5 mm, less than 1.25 mm, less than 1 mm, less than 0.75 mm, less than 0.5 mm, or any range based on any two values ​​described herein.

[0055] Examples of the flexible insulating member of the present invention include, but are not limited to, blankets, mats, pads, or sheets, or other articles.

[0056] The first and second layers may be bonded together such that the two layers cannot be easily separated, for example, by hand. Bonding the first layer to the second layer can be considered as weaving or interpenetration of at least a portion of the surface of the first layer that is in contact with the surface of the second layer. The force required to separate the two layers may be at least 0.5 N, or at least 1 N, or at least 1.5 N, or at least 2 N. The peel force can be measured according to ASTM D751-06 (180-degree test). The bonded layers should have a pressure of at least 0.1 kgf / cm². 3 For example, 0.1~5 4 kgf / cm 3 , or 0.3~4.5 4kgf / cm 3 , or 0.5~4 kgf / cm² 3Alternatively, it may have an average peeling force within any range based on any two values ​​described herein.

[0057] The first and second layers can be bonded together, for example, by a portion of the first layer penetrating, intertwining, or embedding with a portion of the second layer. For example, the first and second layers can be bonded together by calendering or by spot bonding. Alternatively or additionally, bonding the two layers can be achieved, or may include chemical bonding between portions of the first and second layers. For example, a portion of the binder present in at least one of the layers can provide adhesion to the other layer. As another example, by forming the first layer on the second layer by a wet-laid technique (e.g., pouring a slurry of the composition forming the first layer), once the first layer is formed and dries, sufficient adhesion to the second layer can be achieved by itself through the penetration of portions of the first layer into portions of the second layer, and by bonding and / or adhesion resulting from one layer drying on the other.

[0058] Optionally, the bonding of the first layer to the second layer can be achieved without the presence of a chemical adhesive on the layers. Optionally, the first and second layers can be bonded to each other without a separate adhesive layer.

[0059] Optionally, two or more flexible insulating members (e.g., single-layer flexible insulating members or multi-layer flexible insulating members) can be bonded or laminated onto each other. When two or more flexible insulating members of the present invention are bonded or laminated onto each other, each of the flexible insulating members may be the same or different from each other in terms of thickness and / or the constituent components forming each of the insulating members. The laminated members or insulating members may have an overall average thickness of 0.6 mm to 10 mm, or 0.6 mm to 20 mm, or 0.6 mm to 30 mm. Lamination or bonding of insulating members to form an article can be achieved in one of the forms described with respect to bonding a first layer to a second layer to form one insulating member.

[0060] Optionally, in a multilayer flexible insulating member, the first layer partially penetrates or permeates the second layer such that at least a portion of the multilayer flexible insulating member includes a mat in which aerogel and a first fibrous component interlock with each other to define a region within the multilayer flexible insulating member.

[0061] This region could be 1 / 10 to 1 / 4 of the upper part (upper side) of the second layer. This region could be 1 / 4 to 1 / 2 of the upper part of the second layer. This region could be 1 / 2 to 3 / 4 of the upper part of the second layer. This region could be 3 / 4 to 7 / 8 of the upper part of the second layer.

[0062] Flexible insulating material (e.g., single-layer flexible insulating material or multi-layer flexible insulating material) may have a tensile strength of at least 10 N. The tensile strength may be in the range of about 10 N to 90 N, or about 10 N to 80 N, or about 10 N to 70 N, or about 15 N to 70 N, or about 20 N to 70 N, or about 30 N to 70 N, or about 40 N to 70 N, or about 10 N to 60 N, or about 10 N to 50 N, or about 10 N to 40 N, or any range based on any two values ​​described herein. The tensile strength may be considered the ultimate tensile strength. The tensile strength may be the mean tensile strength. The tensile strength may be measured using a constant-speed elongation device in accordance with the ASTM D828 standard test method for tensile properties.

[0063] The aerogel in a single layer or at least a first layer can be any type of aerogel. The aerogel can be aerogel microparticles. The aerogel can be aerogel particles.

[0064] The aerogel may be silica aerogel particles and / or hydrophobic silica aerogel particles.

[0065] The aerogel may be surface-modified using a surface modifier.

[0066] The aerogel in the first layer may be uniformly or evenly distributed throughout the entire first layer.

[0067] Aerogel particles can have particle sizes ranging from 0.1 mm to 5 mm, for example, 0.1 mm to 4 mm, 0.1 mm to 1.5 mm, 0.5 mm to 4 mm, or 1 mm to 4 mm. Further details of the aerogel are provided below in a later section. The particle size range of the aerogel can be determined by sieving.

[0068] The aerogel used for the first layer or monolayer may be characterized by one or more properties. For example, the aerogel (e.g., aerogel particles) may have a porosity of more than about 60% and a density of less than about 0.4 g / cc, or a density of about 0.05 to about 0.15 g / cc.

[0069] The aerogel used may have a thermal conductivity of less than approximately 40 mW / m·K, less than approximately 25 mW / m·K, or approximately 12 mW / m·K to approximately 18 mW / m·K, or lower. The thermal conductivity can be measured as described in the examples.

[0070] The aerogel used may have a caloric content of less than 10 MJ / kg, less than 8 MJ / kg, less than 7 MJ / kg, or less than 6 MJ / kg. The caloric content can be measured using a cylinder calorimeter or other apparatus known to those skilled in the art for such measurement. Methods such as ASTM E711-87 can be used.

[0071] As a further option, all components of the first layer may form an aerogel slurry dispersed in the mat, or they may be part of an aggregated mixture resulting in an aggregated wet-laid material, resulting in an aggregated layer or an aggregated aerogel composition dispersed in the layer.

[0072] The first fibrous components of the first layer may be uniformly or evenly distributed throughout the first layer. Optionally, the first fibrous components may be unevenly distributed throughout the first layer.

[0073] The first fibrous components, together with the aerogel of the first layer, may be uniformly or homogeneously distributed throughout the first layer such that the distribution of each component is substantially the same throughout the first layer (for example, differences of less than 10% by weight, less than 5% by weight, or less than 1% by weight of each component).

[0074] The first fibrous component may be one type of fiber or a combination of two or more types of fibers.

[0075] The fibers may be synthetic fibers and / or natural fibers. The fibers may be polymer fibers or inorganic fibers. The fibers may be one or more microfibers of any of the fibers described herein, including polyester fibers, rayon fibers, spandex fibers, acrylic fibers, metal fibers, glass fibers, ceramic fibers, carbon fibers, rubber fibers, cellulose fibers, lyocell fibers, triacetate fibers, acetate fibers, polyolefin fibers, and / or the fibers described herein.

[0076] Examples of the first fibrous component include, but are not limited to, glass fibers, ceramic fibers, ceramic wool, and / or polymer fibers. Examples of ceramic wool include, for example, zirconium-containing ceramic wool and mineral wool. Polymer fibers may be temperature-resistant polymer fibers such as aramid and / or polybenzimidazole (PBI) fibers. These materials can represent the entire fibrous component or can be used in combination with ceramic fibers (e.g., alumina-silica ceramic fibers). In some cases, ceramic wool, polymer fibers such as aramid and / or polybenzimidazole fibers, and / or combinations thereof, are provided in an amount less than 50% of the total weight of the fibrous component in the first layer.

[0077] The first fibrous component may be present in an amount of at least 10% by weight, such as 10% to 90% by weight, based on the total dry weight of the first layer. This amount may be 20% to 80% by weight, 30% to 70% by weight, 40% to 70% by weight, 50% to 90% by weight, 60% to 90% by weight, 10% to 30% by weight, 10% to 40% by weight, or any range based on any two values ​​described herein.

[0078] The amount of aerogel and the amount of the first fibrous component can be characterized as a weight ratio. The weight ratio of aerogel to fiber may be 10:1 to 1:10 (based on dry weight). This weight ratio may be 10:1 to 9:1, or 10:1 to 8:1, or 10:1 to 7:1, or 10:1 to 6:1, or 10:1 to 5:1, or 10:1 to 4:1, or 10:1 to 3:1, or 10:1 to 2:1, or 10:1 to 1:1, or 1:10 to 1:9, or 1:10 to 1:8, or 1:10 to 1:7, or 1:10 to 1:6, or 1:10 to 1:5, or 1:10 to 1:4, or 1:10 to 1:3, or 1:10 to 1:2, or any range based on any two values ​​described herein.

[0079] In other embodiments, the composition (forming a single layer, a first layer, or a second layer) may include rubber particles such as silicone rubber particles. These particles can be used together with conventional ceramic fibers, and / or wool and / or polymer fibers as described herein (e.g., PBI, aramid).

[0080] With respect to the second layer, the mat is either the second layer or at least part of the second layer.

[0081] The mat can be considered a fibrous mat or a fibrous mat. For the purposes of the present invention, the mat can be considered a mat or a cloth. A “fibrous mat” is considered a ply of chopped (short and / or long) yarns / fibers held together by a binder and / or stitching. A “fibrous cloth” is considered a ply of continuous yarns / fibers manufactured by lamination techniques such as weaving or knitting. For the purposes of the present invention, a “mat containing a second fibrous component” may be either a fibrous mat or a fibrous cloth. The mat preferably meets the UL-94 V0 flame retardancy rating itself.

[0082] Examples of mats include, but are not limited to, chopped strand mats, continuous filament random mats, bale mats, continuous strand fiber mats, continuous strand bale surface mats, woven mats, and non-crimped cloth mats. The mat may be a mycalamine laminate paper layer, a rock wool layer, a slag wool layer, an alumina silica layer, a graphite fiber layer, a mineral wool fiber layer, a ceramic wool layer, a silicone rubber sheet layer, a silica fiber layer, a glass fiber layer, a carbon fiber layer, an e-glass cloth silicon coated ceramic paper layer, an aerogel mat layer, a polyamide paper layer, or any combination thereof, or may include them. One preferred mat may be, for example, a fiberglass mat.

[0083] The mat may be a medium-density fiber mat. The mat may be a high-density fiber mat. The second layer may be a woven or non-woven fabric layer.

[0084] The second layer may be considered to be, or may include, a woven mat or a non-woven mat.

[0085] Examples of commercially available mats that can be used include, but are not limited to, FIBREGLAST mats (e.g., FIBREGLAST 260 mats) or other continuous strand bale surface mats or continuous strand mats such as fiberglass mats.

[0086] The single layer or the second layer may be porous and / or have random openings or voids. The pores or openings or voids may comprise at least 5% of the total volume of the second layer, for example, at least 10%, at least 15%, at least 25%, at least 35%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, for example, 5% to 99%, or 5% to 20%, or 50% to 99%, or 25% to 95%, or 40% to 80%, or 60% to 95%, or 70% to 90% of the total volume of the second layer.

[0087] A single layer or a second layer may have a thickness of 0.2 mm to 0.5 mm or more in at least a portion of the second layer. This thickness may be a maximum thickness measurement or an average thickness measurement. The second layer may vary in thickness across its entire cross-sectional area. The thickness may be 0.2 mm to 0.4 mm, or 0.2 mm to 0.3 mm. The average or maximum thickness of the second layer may be approximately 0.5 mm to 2 mm, or 0.5 mm to 1 mm, or 0.5 mm to 0.75 mm, or any range based on any two values ​​described herein.

[0088] The second layer of mats may include several mats that are laminated, bonded, or otherwise connected to each other in order to form the second layer of mats. If multiple mats are used, the mats may be the same or different from each other.

[0089] A single or second layer of matting may contain a binder and / or other components. This amount may be at least 1% by weight, based on the weight of the matting, such as 1% to 10% by weight or more, 2% to 15% by weight, 5% to 10% by weight, 6% to 15% by weight, or any range based on any two values ​​described herein. Multiple layers, single layers, or all layers may optionally be free of any binder.

[0090] Further details and options for a single layer or a first layer are provided. The first layer may further comprise or include at least one binder. The binder is usually uniformly distributed throughout the layer. The weight ratio of aerogel to binder may be 70:1 to 1:1, or 60:1 to 1:1, or 50:1 to 1:1, or 10:1 to 3:1 (measured, for example, as a wet slurry before wet laying). This weight ratio may be approximately 40:1 to 1:1, or 30:1 to 1:1, or 20:1 to 1:1, or 10:1 to 1:1, or 5:1 to 1:1, or approximately 10:1 to 4:1, or 10:1 to 5:1, or 10:1 to 6:1, or 9:1 to 3:1, or 8:1 to 3:1, or 7:1 to 3:1, or 6:1 to 3:1, or any range based on any two values ​​specified herein.

[0091] A single layer or a first layer may further comprise or include at least one flocculant. The flocculant may typically be uniformly distributed throughout the layer. The weight ratio of aerogel to flocculant may be 20:1 to 1:1, or 10:1 to 1:1, or 5:1 to 1:1, or 3:1 to 2:1 (measured, for example, as a wet slurry before wet-laid). This weight ratio may be 4:1 to 1:1, or 3:1 to 1:1, or 2:1 to 1:1, or about 3:1 to 2.5:1, or 3:1 to 2.75:1, or any range based on any two values ​​described herein.

[0092] The flocculant in a single layer or a first layer may be present in an amount of 1% to 10% by weight (dry mass) based on the total dry weight of the first layer. This amount may be 1.5% to 10% by weight, 2% to 10% by weight, 3% to 10% by weight, 4% to 10% by weight, 5% to 10% by weight, 6% to 10% by weight, 7% to 10% by weight, or any range based on any two values ​​described herein. Multiple layers, single layers, or all layers may optionally be free of any flocculant.

[0093] The flocculant may be an organic flocculant. The flocculant may be an inorganic flocculant. The flocculant may be a polymeric organic flocculant. The flocculant may be an inorganic salt of a polyvalent metal (e.g., aluminum, iron, calcium, magnesium, or zinc).

[0094] The flocculant may be a polymer flocculant, such as a polymeric organic flocculant. Examples include polyelectrolytes (cationic or anionic), nonionic polymers, polysaccharides (e.g., starch, cationic chitosan, etc.), polypeptides, polyamines, or polyacrylamides. Other examples of flocculants include, but are not limited to, aluminum sulfate (alum), aluminum chloride, sodium aluminate, aluminum chlorohydrate, polyaluminum chloride, ferric chloride, ferric sulfate, ferrous sulfate, ferric chloride, or their calcium salt versions, or their magnesium salt versions, or their zinc salt versions.

[0095] A single layer or a first layer may further comprise or include at least one viscosity modifier. The viscosity modifier in a single layer or a first layer may be present in an amount of 1% to 10% by weight (dry mass) based on the total dry weight of the first layer. This amount may be 1.5% to 10% by weight, 2% to 10% by weight, 3% to 10% by weight, 4% to 10% by weight, 5% to 10% by weight, 6% to 10% by weight, 7% to 10% by weight, or any range based on any two values ​​described herein. A multilayer or single layer, or all layers, may optionally be free of any viscosity modifier.

[0096] Viscosity modifiers can typically be uniformly present throughout the layer. The weight ratio of aerogel to viscosity modifier can be 90:1–1.5:1, or 80:1–1.5:1, or 70:1–1.5:1, or 60:1–1.5:1, or 50:1–1.5:1, or 40:1–1.5:1, or 30:1–1.5:1, or 20:1–1.5:1, or 10:1–1.5:1, or 5:1–1.5:1 (measured, for example, as a wet slurry before wet laying). This weight ratio can be approximately 5:1–2:1, 5:1–2.5:1, 5:1–3:1, 4:1–1.5:1, 3.5:1–1.5:1, or any range based on any two values ​​described herein.

[0097] The single layer or first layer of the insulating material may be such that aerogel (e.g., aerogel particles) can be present in the single layer or first layer in an amount of 10% to 90% by weight, based on the total dry weight of the first layer. This amount may be 20% to 80% by weight, 30% to 70% by weight, 40% to 70% by weight, 50% to 90% by weight, 60% to 90% by weight, 10% to 30% by weight, 10% to 40% by weight, or any range based on any two values ​​described herein.

[0098] A single layer or first layer of an insulating material may be such that a first fibrous component (e.g., glass fiber) can be present in the single layer or first layer in an amount of 10% to 90% by weight, based on the total dry weight of the first layer. This amount may be 20% to 80% by weight, 30% to 70% by weight, 40% to 70% by weight, 50% to 90% by weight, 60% to 90% by weight, 10% to 30% by weight, 10% to 40% by weight, or any range based on any two values ​​described herein.

[0099] The first layer may be a nonwoven fabric layer. In at least one embodiment, the first layer can be considered a wet-laid nonwoven fabric layer.

[0100] Additional components may be present in the monolayer or the first layer. The monolayer or the first layer may further comprise or include at least one polymer, at least one metal oxide, and / or at least one inorganic particle other than a metal oxide. The first layer or the slurry used to produce the first layer may further comprise materials such as an IR opacifier, and / or a flame retardant or fire retardant, and / or a heat absorber, and / or a processing aid. Other examples include one or more binders, water, dispersants, emulsifiers, and / or flocculants, which may be included as needed in the production of the monolayer and / or the first layer and / or the second layer.

[0101] A single layer or a first layer may further comprise or include at least one IR opacifier. Examples of IR opacifiers include, but are not limited to, carbon black, alumina, graphite, titanium dioxide, iron oxide, silicon carbide, or zirconium dioxide, or any combination thereof.

[0102] Further details are provided regarding the aerogel components of a single layer or a first layer.

[0103] In certain embodiments, the aerogel is a silica aerogel in the form of fine particles. Any type of silica aerogel particles can be used in the mixture. The aerogel can be formed as described in U.S. Patent No. 7,470,725. Suitable aerogels can be made from water glass or organic materials such as TEOS and TMOS. To reduce the contribution of radiation to thermal conductivity, IR opacifiers such as carbon black, alumina, graphite, titanium dioxide, iron oxide, silicon carbide, zirconium dioxide, or mixtures thereof can be incorporated into the aerogel particles. Aerogel particles are available from various suppliers, including Cabot Corporation under the ENOVA and ENTERA brands, and JIOS Aerogel under the AEROVA brand.

[0104] The aerogel may optionally be surface-modified. Various surface modifiers are described in U.S. Patent Application Publication No. 2001034375, which is incorporated herein by reference in whole.

[0105] Silica aerogels can have particle sizes ranging from 0.1 mm to 5 mm, for example, 0.1 mm to 4 mm, 0.1 mm to 1.5 mm, or 1 mm to 4 mm. Aerogels can have narrow or broad particle size distributions and can be in the form of crushed powder. The diameter of the aerogel particles is measured along the longest cross-sectional line in a given particle.

[0106] Silica aerogel particles are hydrophobic and can exhibit a water contact angle greater than 90 degrees. Examples of commercially available aerogels include ENOVA brand aerogels from Cabot Corporation, as well as P100 and P200 aerogels, also from Cabot Corporation.

[0107] The aerogel may be a mixture of silica aerogel and hydrophobic silica aerogel.

[0108] Aerogel particles are also commercially available as mixtures with opacifying agents such as carbon black.

[0109] The aerogel is preferably preformed (prepared before the fabrication of the first layer as described herein) so that any desired aerogel structure, morphology, or other properties can be selected, which may often be present in the final product.

[0110] Further details are provided regarding the first fibrous component. The fibrous component may include ceramic wool and / or temperature-resistant polymer fibers. Examples of such polymer fibers are polybenzimidazole (PBI), aromatic polyamide (aramid), or any combination thereof. These materials may be supplied in amounts of 0.5 to 100% by weight based on the total weight of all fibrous components in the first layer. In one embodiment, the wool and / or temperature-resistant polymer fibers are supplied in a relative amount of less than 50% by weight, for example, 40, 30, 20, or even less than 10% by weight, based on the total weight of all fibrous components in the first layer.

[0111] Ceramic fibers are typically produced by a drawing process and then cut to the desired length, while ceramic "wool" (or other types of wool, e.g., mineral wool, and sometimes "stone" wool) is often produced by spinning a molten material. Generally, wool tends to have longer, more entangled fibers. Individually, wool fibers may not be stronger than shorter ceramic fibers (produced by drawing and cutting). However, in bulk, wool can have an additive effect that can improve the mechanical integrity of thermally controlled articles.

[0112] The diameter of wool fibers can range from approximately 1 micron (μm) to several hundred microns. The fiber length can range from approximately 100 μm to several hundred μm or more, and sometimes reach several hundred millimeters (mm) in length.

[0113] These high aspect ratio wools also have the effect of improving drainage and retention in wet-laid articles, as they provide extra surface area for the active material to be sufficiently dispersed to aggregate during the solidification process. This reduces the amount of active material removed along with excess process water during the formation process.

[0114] The amount of ceramic wool that can be used often depends on the desired properties (e.g., tensile strength, tear resistance, impact resistance), the intended application, and / or other factors. Ceramic wool may be supplied in amounts ranging from 0.5 to 100% by weight (relative to the weight of the fibrous components used to prepare the composition of the first layer). Optionally, ceramic wool may be present in amounts ranging from about 5 to about 30% by weight. For example, ceramic wool may be present in the fibrous components in amounts ranging from about 10 to about 20% by weight, based on the total weight of the fibrous components in the first layer.

[0115] For a finished product, such as a blanket, ceramic wool may be present in the final product in an amount of approximately 0.5 to 2% by weight, such as within the range of 0.25% to 4% of the weight of the first layer, for example, within the range of approximately 0.5 to 1.0%, approximately 0.5 to 1.5%, approximately 0.5 to 2.0% by weight, or within the range of approximately 1.0 to 1.5%, approximately 1.0 to 2% by weight, or approximately 1.5 to 2.0% by weight.

[0116] Suitable ceramic wools include aluminum (provided as Al2O3), silicon (in the form of SiO2), and iron (in Fe2O3), or any combination thereof. Some ceramic wools may also include titania (TiO2) in addition to or instead of any of these components.

[0117] Although not a required element, the presence of zirconium can provide mechanical benefits and / or contribute to the temperature resistance of the final heat-controlled article (e.g., blanket). In some embodiments, zirconium (typically in the form of zirconium oxide (ZrO2)) is provided in zirconium-containing wool, which may also contain other elements such as aluminum, silicon, iron, and / or titanium. Commercially, Ceramaterials (Dingmans Ferry, PA) offers two types of spun fibers, one with a higher zirconia concentration (with a temperature resistance of up to 2600°F / 1400°C) and the other with a lower zirconia content (2300°F / 1400°C).

[0118] Another type of wool that can be used to prepare the compositions described herein is mineral wool (sometimes also known as "stone" wool). Mineral wool is commercially available from Rockwool A / S, Knauf Insulation (Shelbyville, IN, USA), and other suppliers under the trade name "Rockwool®" mineral wool. The amount of mineral wool may be the same as or similar to that used for ceramic wool. However, other ranges may also be used.

[0119] In some embodiments, the compositions described herein for forming the first layer may contain various forms of temperature-resistant polymer materials. Some approaches utilize aramid fibers, which may be defined as "pulp" (0.1–6 mm) or short fibers (greater than 6 mm). Aramid short fibers and pulp are widely available, with DuPont (under the trade name Kevlar®) being a major global manufacturer.

[0120] Another approach utilizes polybenzimidazole (PBI) fibers, which typically exhibit excellent heat and chemical resistance. PBI fibers have no distinct melting point and therefore do not ignite or drip when exposed to high temperatures. PBI fibers can be purchased from PBI Performance Products (Charlotte, NC).

[0121] Materials such as aramid or PBI fibers are considered particularly useful in addressing the bulging and shrinking observed in battery packages when charging or discharging under high or low temperature conditions. By allowing the battery case to expand, pressure on the battery compartment is reduced, thereby decreasing wear and tear on the battery material.

[0122] While these polymer fibers still impart these advantageous properties, their addition can impair the desired low flammability grade of the finished product, such as a blanket; therefore, these polymer fibers are typically used in the smallest possible amount.

[0123] PBI and / or aramid fibers may be provided in an amount ranging from about 0.5 to 100% by weight (relative to the weight of the fibrous components used to prepare the composition forming the first layer). In exemplary examples, PBI and / or aramid fibers may be present in an amount ranging from about 5 to about 30% by weight. For example, PBI and / or aramid fibers may be present in the fibrous components in an amount ranging from about 10 to about 20% by weight.

[0124] Fibers such as aramid or PBI can be used in amounts of 0.25% to 4% (based on the weight of the article), for example, in the range of about 0.5% to about 1.0% by weight, about 0.5% to about 1.5% by weight, about 0.5% to about 2.0% by weight, or in the range of about 1.0% to about 1.5% by weight, about 1.0% to about 2% by weight, or about 1.5% to about 2.0% by weight, for example, in amounts of about 0.5% to about 2% by weight.

[0125] Suitable chopped ceramic fibers that can be used in the compositions described herein include one or more (two, three, four, or more) inorganic oxides such as Al2O3, B2O3, Na2O, K2O, CaO, and MgO. Some fibers may also contain silicon dioxide. Many types of ceramic fibers are commercially available, often well-characterized with respect to composition, length, and / or other properties. Suitable chopped ceramic fibers include, but are not limited to, Unifrax's 7000 and 6000 series fibers. In one example, the ceramic fiber is a coarsely chopped, high-purity alumina-silica product from Unifrax.

[0126] Glass or other fibers can typically be used in combination with the ceramic fibers and / or ceramic wool, aramid and / or PBI fibers described above. Exemplary glass fibers include, for example, borosilicate (B fibers) and calcium aluminoborosilicate (E fibers) which can be obtained from Lauscha Fiber International, and / or silica-based fibers (Q fibers) which can be obtained from, for example, Johns Manville.

[0127] Other fibers that can be added to ceramic fibers, ceramic wool, and / or polymer fibers such as PBI or aramid include non-ceramic fibers such as cellulose, cotton, carbon, acrylic, polyvinyl alcohol (PVA), phenol, polyolefin, and / or other types of fibers, as well as mixtures of such fibers.

[0128] The fibers used may be of any configuration known to those skilled in the art. For example, the fibers may be in the form of chopped fibers, microfibers, woven fibers, or nonwoven fibers.

[0129] The shape of the fiber cross-section can be circular, polygonal, trefoil, pentaphylla, octaphylla, strip, fir tree, dumbbell, or other shapes. The fiber may have a constant or varying diameter along its length. In some embodiments, hollow fibers can be used. Furthermore, the fiber material may be smooth or crimped, curled or straight.

[0130] In some embodiments, coated fibers can be used. One example is polyester fibers metallized with a metal such as aluminum.

[0131] Fibers modified with additives are also preferred. Examples of such additives include, but are not limited to, antistatic agents such as carbon black; and / or IR opacifiers such as carbon black, titanium dioxide, alumina, iron oxide, or zirconium dioxide, silicon carbide, or any mixture thereof (typically used to reduce the contribution of radiation to thermal conductivity). The amount of each additive or the total amount of additives can be 0% to 20% by weight on a dry weight basis, based on the entire layer or insulating material. These amounts may be at least 1% by weight, at least 2% by weight, at least 5% by weight, at least 10% by weight, or at least 15% by weight, such as 0.1% to 20% by weight, or 0.5% to 20% by weight, or 1% to 20% by weight (based on the dry weight basis of the entire layer or insulating material).

[0132] In addition to including an IR opacifier, the radiation contribution to thermal conductivity can be further reduced by using blackened polyester fibers blackened with carbon black or simply carbon fibers.

[0133] The amount of fiber used depends on its density, diameter, length, etc., and can be 1% to 99% of the weight of the first layer. In certain embodiments, the weight ratio of the aerogel component to the first fibrous component may be in the range of 1:10 to 10:1, for example, 1:1 to 1:2.

[0134] The length and diameter of fibers, often ceramic fibers, can be varied depending on the specific application. For example, thinner fibers can add flexibility, while the length and / or distribution of the fibers can play a role in increasing the mechanical strength of the final product, such as a blanket. By using two or more different types of fibers, or fibers made from the same material but featuring different fiber lengths, a bimodal or multimodal length distribution of the fibers can be obtained.

[0135] In addition to the aerogel components, the compositions described herein preferably further comprise one or more other components. Often, these components or components are selected to impart specific functions and / or properties to the final article (e.g., a blanket). In some cases, the type and / or amount of added components is selected to achieve a balance or compromise between desirable and less desirable contributions that the components may bring to the final product. Manufacturing parameters, end-use, or other factors may be considered when selecting the type and / or amount of components used.

[0136] In some embodiments, the composition includes silicone particles. This material is thought to potentially improve both the strengthening and elasticity of the finished product, such as a blanket.

[0137] Silicone powders or particles with various average particle sizes (avg PS), for example, in the range of approximately 1 micron to 1 mm in diameter, are commercially available. For example, suppliers such as Shin-Etsu Silicone offer suitable elastic particles in their KMP series of silicone powders. For instance, particles with an avg PS of 13 μm are available under product code KMP-598, while product KMP-402 offers a PS of 30 μm.

[0138] The suitable amount that can be used can be determined by taking into account the desired properties, manufacturing parameters, and / or other factors. In some embodiments, the silicone particles are supplied in a ratio of up to 1:1 (e.g., by weight) relative to the aerogel components.

[0139] Silicone rubber particles can be used in conjunction with ceramic fibers and / or wool and / or temperature-resistant polymer fibers as described herein. For example, they can be combined with aerogel particles, ceramic fibers and / or ceramic wool, aramid fibers and / or PBI fibers. Alternatively, silicone particles can be used in compositions that do not contain ceramic wool or polymer fibers such as aramid or PBI.

[0140] In many embodiments, the compositions described herein include opacifiers, such as infrared (IR) opacifiers, to reduce radiant heat transfer. These materials reduce the transmission of infrared radiation and may include, for example, carbon black, mica, alumina, graphite, titanium dioxide, rutile sand, iron oxide, silicon carbide (SiC), graphite, or zirconium dioxide. Some preferred types of titanium dioxide include, for example, Tipure® (DuPont) and Altiris® (Huntsman). IR opacifiers can be used alone or as a mixture of two or more compounds.

[0141] IR opacifiers can be added in amounts that result in a target level of IR transmission reduction in a thermally controlled article (e.g., a blanket). Exemplary such levels may be 2%–150%, 2%–100%, or 5%–40% of the opacifier, based on the weight of the mixture of silica aerogel and hydrophobic silica-containing particles. The range of IR wavelengths covered can be expanded by adding opacifiers with two or more different average particle sizes to a given composition.

[0142] In some embodiments, the heat-controlled article (blanket) may contain a flame retardant or fire retardant. The flame retardant may be, for example, an alkali oxide, an alkaline earth metal oxide, an aluminum trihydrate, magnesium hydroxide, antimony oxide, titanium dioxide, rutile sand, a melamine compound, a phosphate compound, or a halogen compound. In certain embodiments, the titanium dioxide particles may have a diameter of about 1.18 μm, 0.9–1.3 μm, 0.8–1.4 μm, or 0.5–4.0 μm, and in certain embodiments, the particle size distribution may have a d50 of about 1.0 μm + / - 0.01 μm, + / - 0.02 μm, or + / - 0.05 μm. Examples of halogenated flame retardants include brominated flame retardants (BFRs), such as organic bromine compounds including polymeric organic bromine compounds. In another set of embodiments, the flame retardant has a structure with a high ratio of heteroatoms to carbon atoms. For example, in some embodiments, the heteroatom:carbon atom ratio may be greater than 0.5:1, greater than 1:1, or greater than 2:1, and in certain embodiments, the heteroatom may be nitrogen and / or sulfur. Flame retardants and / or fire retardants can be incorporated into the thermal control member at concentrations sufficient to suppress flammability or to meet specifications such as UL94-V0. Alternatively or additionally, embodiments of the thermal control member may exhibit calorie content of, for example, less than 10 MJ / kg, less than 8 MJ / kg, less than 5 MJ / kg, less than 3 MJ / kg, less than 2 MJ / kg, or less than 1 MJ / kg, for example, 0.5 MJ / kg or 1 MJ / kg to 5 MJ / kg.

[0143] The concentration of the fire retardant and / or flame retardant that can be used (for example, in the first layer and / or both layers) may be in the range of 0.1% to 5.0% by weight, 0.2% to 2.0% by weight, and 0.3% to 1.5% by weight relative to the mass of the heat control member. In certain embodiments, the flame retardant or fire retardant is combined with aerogel particles and a mixture of, for example, silica aerogel and hydrophobic silica-containing particles.

[0144] Heat-absorbing materials can also be used. Such materials help thermally controlled articles (e.g., blankets) function not only as insulators that slow heat transfer but also as heat accumulators that can store thermal energy. Examples of such heat-absorbing materials include aluminum hydroxide and others known to those skilled in the art. Alternatively or additionally, heat-absorbing materials may include phase-change materials that store heat by undergoing a thermodynamic phase transition. Heat-absorbing materials can be combined with aerogel particles and / or hydrophobic silica aerogel, or deposited on the surface of aerogel pores, or impregnated into aerogel pores.

[0145] The composition for forming the first layer may include a binder. In some cases, the binder can help prevent widespread dispersion or dissipation of silica aerogel, hydrophobic silica-containing particles, and / or other particulate components of the insulating material in the event of a catastrophic failure or explosion of an insulated item, such as a battery. Examples of suitable binders include, but are not limited to, silicone, polyvinyl alcohol, polyvinylidene fluoride, polyethylene terephthalate, polybutylene terephthalate, and acrylate polymers. Binders containing heat-resistant polymers and / or flame-retardant polymers are preferred. Binders such as polyvinyl alcohol can also bind additives such as carbon black to the aerogel particles to reduce dust scattering during assembly. The binder may be mixed with some or all of the components of the mixture, including any additives to be incorporated into the mixture, using an impeller or other suitable apparatus known to those skilled in the art. Preferably, the binder does not make the aerogel blanket flammable by UL94 or other flammability test methods.

[0146] Processing aids may also be included in the composition forming the first layer. The selected processing aids depend on the manufacturing method and form of the heat-controlled article. Suitable processing aids include, but are not limited to, defoamers, surfactants, dispersants, and emulsifiers.

[0147] In many cases, components can be combined in any preferred manner, but techniques for incorporating some of the constituent components can benefit from further consideration. For example, in the case of fibers, if the mixing energy is too low, undispersed fiber bundles may be produced that do not efficiently improve performance. On the other hand, excessive dispersion (under unlimited length mixing or mixing energy) can lead to self-entanglement and "boring." Excessive chopping and cutting energy will shorten the fiber length below the ideal length, which may affect the attributes or performance of the product. Regarding equipment, it has been found that mixing operations relying on cutting blades with sharp leading edges can also contribute to a reduction in fiber length. On a short timescale, this may be relatively harmless, but the effect is expected to accelerate over longer periods.

[0148] Furthermore, it was found that certain properties of the materials being incorporated can make them more susceptible to the "over-processing" effect. For example, in the case of fibers, this effect is more pronounced with respect to fiber lengths longer than approximately 6 mm (0.25 inches) and / or finer roughness.

[0149] Accordingly, some embodiments described herein relate to controlling some of the mixing parameters, such as mixing time, supplied energy, and type of equipment, for example, blade type. In certain examples, the mixing parameters take into account the properties of the material being processed. In other examples, the properties of the material are evaluated and then correlated to suitable mixing parameters. The establishment of suitable mixing parameters can be based on routine experiments, prior experience, etc.

[0150] To form the first layer described herein (or to form a slurry dispersed in a mat for a single layer), the components can be combined in any preferred manner and may involve a single step. However, often the mixing is carried out in a series of two or more steps using equipment known in the art. In one example, aerogel particles and fibers are added to a solution containing processing aids such as an antifoaming agent, a surfactant, a dispersant, and / or an emulsifier.

[0151] The first layer may take any form known to those skilled in the art. For example, the techniques described in U.S. Patent No. 9,399,864, U.S. Patent Application Publication No. 2021 / 0363699, International Publication No. 2022024085, Chinese Patent No. 112759353, U.S. Patent No. 11274044, Chinese Patent No. 112681009, No. 113943171, No. 110093783, No. 112681009, Application Publication No. 2015-048543, and / or U.S. Patent Application Publication No. 2020 / 0295328 can be used in preparing the first layer, taking into account the details of the first layer provided herein, and all of these contents are incorporated herein by reference. This can also be applied to the formation of a single layer.

[0152] As shown, the first layer can be formed by a wet-laid process. Furthermore, the dispersion of aerogel and the first fibrous component in a mat to form a monolayer can also be achieved by a wet-laid type process. Generally, in a "wet-laid" process, aerogel particles and optionally selected materials are aggregated from an aqueous slurry to form a substantially stable, homogeneous suspension (floc) of particles. The floc can be separated from the aqueous solvent to form a two-phase system consisting of aggregated aerogel particles and a substantially aqueous supernatant. The aggregated material can support a uniform distribution of different particles that can make up the first layer. This stable, uniform distribution of particles can provide a first layer exhibiting a uniform composition throughout.

[0153] In one embodiment, such as that described in U.S. Patent No. 9,399,864, the aqueous slurry is prepared using a mixture of silica aerogel, hydrophobic silica-containing particles, ceramic fibers, and other components (e.g., binders, opacifiers, fire retardants, defoamers, etc.). A charged compound or other emulsifier or dispersant is added to the slurry to produce an emulsion, which is then coagulated with a flocculant. This process can be employed herein in consideration of the embodiments of the present invention described herein.

[0154] The resulting floc can then be poured onto a second layer or placed elsewhere, the second layer may be on a belt. The first and second layers can then be dewatered.

[0155] Optionally, the act of flocculating the composition forming the first layer (e.g., slurry) can be controlled to result in smaller flocs. Smaller flocs are discharged more slowly when wet-laid onto the second layer and can intertwine with the fibrous second layer. This can result in better overall properties in the final product, such as combustion and / or adhesion properties. Optionally, flocculation can be under-flocculated, meaning that flocculation in the slurry does not reach completion (e.g., under-flocculation can be less than 99% completion, less than 95% completion, less than 90% completion, less than 85% completion, less than 80% completion, etc., where % is the degree of flocculation out of 100% complete flocculation). This can be achieved by using less flocculant.

[0156] While not bound by any particular theory, it is believed that as aggregation becomes more efficient, the aerogel particles can be packed more densely into the first layer. In a preferred embodiment, the aerogel particles constitute at least 40 mass%, for example, at least 42 mass%, at least 44 mass%, at least 46 mass%, at least 48 mass%, or at least 50 mass%, for example, 40 mass% to 55 mass%, 40 mass% to 60 mass%, or 40 mass% to 65 mass% of the first layer.

[0157] The flocculant is preferably capable of flocculating enough solids in the mixture so that the majority of the solids float on top of the aqueous mixture, keeping the aqueous medium relatively clear rather than cloudy. Examples of flocculants include, but are not limited to, polydiallyldimethylammonium chloride (PDADMAC) and SuperFloc® 577 (Kemira).

[0158] In one embodiment, the packing density of various components may be increased before drying by using compression to push out additional water from the flocs. For example, the flocs can be passed through a roll press. The roll press increases the packing density of the various components by squeezing out water from the flocs. In the final product, this reduces pores between particles as residual water is replaced by air during drying.

[0159] Flexible insulating members (e.g., blankets) may be manufactured in a substantially planar or flat form for insertion between cells of a rechargeable battery, such as a lithium-ion battery. In other approaches, the insulating members may be prepared in other desired shapes. For example, insulating articles may be molded to be positioned around specific components within a battery or other device and may have more complex shapes.

[0160] In some embodiments, the insulating article includes additional sheet-like material to improve mechanical integrity, heat resistance, mechanical elasticity, and / or other properties. Examples include, but are not limited to, silicone-based materials, polyvinylidene fluoride, chlorinated polyethylene, aramid materials such as Kevlar (e.g., aramid fiber woven mats), and Kevlar nanofiber aerogels, such as those described in Lyu, et al., ACS Nano 2019, 13, 2236-2245. Kevlar or other aramid fiber woven mats may be impregnated with a shear-thickening fluid as described in U.S. Patent No. 7,825,045 (the contents of which are incorporated herein by reference).

[0161] In some cases, an envelope can be used to serve roles such as preventing dust dispersion, helping to maintain the shape of the insulating material, and facilitating the handling or installation of the insulating material. The material forming the envelope is preferably a flame-retardant and / or heat-resistant polymer material, including, for example, silicone, polyvinylidene fluoride (PVDF), chlorinated polyethylene, and other similar polymers known to those skilled in the art. Alternatively or additionally, the envelope material may include reinforcing fibers, such as aramid fibers, to provide puncture resistance. The reinforcing material may be used in combination with other polymers, or the entire envelope may be formed from such a polymer, for example, a woven fabric of aramid fibers.

[0162] For example, a first layer (or single layer), which may be a nonwoven blanket produced by a wet-laid process, is considered to provide significant benefits to the finished product. Therefore, the insulating materials described herein can have excellent insulating properties, for example, to reduce heat transfer from a battery cell experiencing thermal runaway to an adjacent cell or other battery component. The composition is preferably flame-retardant, and the composition will produce an article that will pass the UL94-V0 test or other flammability / combustibility tests.

[0163] Figures 1 to 5 illustrate various embodiments of the present invention. Specifically, Figure 1 is an enlarged side view of one embodiment of the flexible insulating member 10 of the present invention, which is multilayered and has slight interlocking or mixing between the first and second layers. As shown in Figure 1, the first layer 18 is located on top of the second layer 19, and the two layers are bonded to each other. The bottom of the first layer 18 is slightly interlocked or mixed with the top of the layer 19. Aerogel particles 12 (of various sizes, of any choice) and the first fibrous component 14 form at least partially the first layer 18. The second layer 19 is formed from the second fibrous component 16.

[0164] Figure 2 is an enlarged side view of another embodiment of the flexible insulating member 20 of the present invention, which is multilayered and has more interlocking or mixing between the first and second layers (approximately 10% to 50% of the thickness of the second layer) to define the interlocking or penetration region 13. Figure 2 shows the same components as Figure 1 in other respects.

[0165] Figure 3 is an enlarged side view of another embodiment of the flexible insulating member 30 of the present invention, which is multilayered and has even more interlocking or mixing between the first and second layers (approximately 50% to 90% of the thickness of the second layer) defining the interlocking or penetration region 13. Figure 3 shows the same components as Figure 1 in all other respects.

[0166] Figure 4 is an enlarged side view of a further embodiment of the flexible insulating member 40 of the present invention, which is a single layer 19 in which the aerogel 12 and the first fibrous component 14 are fully interlocked, embedded, or penetrated in the upper portion of the mat 16. As shown in Figure 4 (arrow 21), the aerogel 12 and the first fibrous component are partially and slightly exposed on the upper outer surface of the single layer 19.

[0167] Figure 5 is an enlarged side view of a further embodiment of the flexible insulating member 50 of the present invention, which is a single layer 19 in which the aerogel 19 and the first fibrous component 14 are fully interlocked, embedded, or penetrated throughout the entire thickness of the mat 16. The more easily visible mat 16 (Figure 4) is fully interlocked or embedded with the aerogel 12 and the first fibrous component 14 in Figure 5. As also shown in Figure 5 (arrow 21), the aerogel 12 and the first fibrous component 14 are not exposed on the upper outer surface of the single layer 19.

[0168] Additional advantages to insulating materials may include increased flexibility, compressibility, elasticity, tensile strength, and / or impact resistance. By allowing the battery container to expand and contract, these articles contribute to mitigating the effects of dimensional changes in the battery compartment (e.g., cells, modules, and packs), thereby reducing the wear that this type of cycle may have on the battery material.

[0169] The insulating material may exhibit excellent thermal stability. For example, the insulating material may shrink by less than 2% after aging at 650°C according to ASTM-C356. The insulating material may have a thermal conductivity at 25°C of less than 40 mW / m·K or less than 30 mW / m·K, preferably less than 25 mW / m·K, more preferably less than 20 mW / m·K, according to the test method ASTM C518, for example, 5 mW / m·K to 20 mW / m·K or 8 mW / m·K to 15 mW / m·K or 15 mW / m·K to 25 mW / m·K (or any range based on any two values ​​described herein).

[0170] The insulating material may have a property called flexibility, which can be measured according to ASTM C1101 or another suitable technique. Manual bending tests can be particularly useful in the initial screening stage of a product.

[0171] In a particular embodiment, the insulating material is a blanket having a flame retardant flammability rating according to UL94-V0.

[0172] The flexible insulating members (either single-layer or multi-layer) provided herein may further be part of a composite insulating structure. In one embodiment, the composite insulating structure includes a sandwich of two, three, or more flexible insulating members provided herein, at least one of which contains a higher concentration of an IR opacifier, such as carbon black. The concentration of carbon black may be 0.5 to 10% by weight, for example, 1% to 8% by weight, or 3% to 6% by weight. Carbon black is one of the most effective IR opacifiers, but it is highly flammable. By protecting a flexible insulating member with a higher concentration of carbon black with a flexible insulating member having a lower concentration of carbon black (less than 0.5% by weight, e.g., less than 0.4 or 0.3% by weight) or no carbon black, the carbon black can provide IR absorption at high temperatures (close to and above 1000 degrees) where IR conduction is a crucial vector for heat transfer, while the less carbon black, e.g., carbon black-free, flexible insulating member acts as a thermal buffer, protecting the carbon black-rich flexible insulating layer from oxidation. Alternatively, a carbon black-rich flexible insulating member can be sandwiched between two less carbon black flexible insulating members to form a three-part composite.

[0173] Alternatively or additionally, the flexible insulating material may be made from a carbon black-rich or carbon black-low material and used in combination with aerogel blankets or paper manufactured from aerogel and fibers by other means, and with less or more carbon black, respectively. For example, a carbon black-rich flexible insulating member may be sandwiched between one or more carbon black-low aerogel blankets and papers produced according to other methods known to those skilled in the art, such as those described in U.S. Patent No. 1,1380953, No. 9868843, International Publication No. 2022024085, U.S. Patent No. 1,1274044, International Publication No. 2021045484, No. 2021219976, No. 2022189425, U.S. Patent Application Publication No. 2022 / 200080, International Publication No. 2024059682, No. 2023230251, U.S. Patent No. 7,635411, and No. 9399864, all of which are incorporated herein by reference. Such aerogel blankets or pads may contain 10% to 90% by weight of aerogel, for example, 20% to 80% by weight, or 30% to 70% by weight, or 40% to 50% by weight of aerogel. Such aerogel blankets or pads may contain 10% to 90% by weight of fiber, for example, 20% to 80% by weight, or 30% to 70% by weight, or 40% to 50% by weight of fiber. The fiber may be any of the fibers described above, or it may be fiberglass or another woven or nonwoven fiber mat. Alternatively or additionally, one or more low-carbon-black flexible insulating members may be used to sandwich the carbon-black-rich aerogel blanket and paper produced according to other methods known to those skilled in the art, including any of the patent documents listed above.

[0174] A composite insulating structure can be produced by laminating two or three flexible insulating members or other aerogel blankets or papers together with adhesive, or by utilizing any adhesive tendency of such materials. Alternatively or additionally, a second layer may be applied as a coating on the flexible insulating members by spray coating, using emulsions, or using other coating techniques known to those skilled in the art. In this embodiment, formulations similar to those used to produce the flexible insulating members (except, if necessary, containing more or less carbon black) can be used. Alternatively or additionally, additional emulsions may be aggregated on the flexible insulating members, and the mat may be essentially replaced by the flexible insulating members in the manner provided herein. If the composite insulating structure is a three-part structure, each of the three parts may be formulated and / or bonded differently to form a complete composite insulating structure.

[0175] The carbon black may be any carbon black known to those skilled in the art. A carbon black with a small surface area, for example, one with an iodine value of 15-60 g / kg, is preferred. Exemplary carbon blacks include Regal 85, Spheron 6000, and Monarch 120 carbon black from Cabot Corporation. Alternatively or additionally, a surface-treated carbon black to lower the pH, such as Mogul E carbon black from Cabot Corporation, may be used. Such carbon blacks may be more compatible with water-based systems for preparing the flexible insulating layer provided herein, or for other aerogel blankets and papers prepared using aqueous media. Alternatively, carbon blacks with a higher surface area may provide enhanced IR opacity. Such carbon blacks may also produce viscosity at lower addition levels, requiring increased use of dispersants. Exemplary higher surface area carbon blacks include, but are not limited to, Monarch 570 and Mogul L carbon black from Cabot Corporation. Other suitable carbon blacks are available commercially from Cabot Corporation under the trademarks Regal®, Black Pearls®, Elftex®, Monarch®, Mogul®, Spheron®, Sterling®, and Vulcan®. Other commercially available carbon blacks include, but are not limited to, those available from Birla Carbon under the trademarks Raven®, Statex®, Furnex®, and Neotex®, and those available from Orion Engineered Carbons under the trademarks Corax®, Durax®, Ecorax®, and Purex®.Other carbonaceous IR opacifiers that may be used in addition to or instead of carbon black (but in the same proportions as described above) include, but are not limited to, activated carbon, carbon aerogels, carbon xerogels, carbon fibers, recycled carbon from the thermal decomposition of carbon black-filled plastics or elastomers, and partially carbonized polymer fibers such as partially carbonized polyacrylonitrile or polyamide fibers, or any combination thereof.

[0176] Alternatively or additionally, composite insulating structures include flexible insulating members combined with additional sheet-like materials to improve mechanical integrity, heat resistance, mechanical elasticity, and / or other properties. Examples include, but are not limited to, silicone-based materials, polyvinylidene fluoride, chlorinated polyethylene, aramid materials such as Kevlar (e.g., aramid fiber woven mats), and Kevlar nanofiber aerogels, such as those described in Lyu, et al., ACS Nano 2019, 13, 2236-2245. Kevlar or other aramid fiber woven mats may be impregnated with shear-thickening fluids, such as those described in U.S. Patent No. 7,825,045 (the contents of which are incorporated herein by reference).

[0177] Alternatively or additionally, the composite insulating structure includes a flexible insulating member combined with an envelope that can prevent dust scattering, help maintain the shape of the flexible insulating member, and facilitate the operation or installation of the flexible insulating member. The material forming the envelope is preferably a flame-retardant and / or heat-resistant polymer material, including, for example, silicone, polyvinylidene fluoride (PVDF), polyethylene terephthalate (PET), chlorinated polyethylene, and other similar polymers known to those skilled in the art. Alternatively or additionally, the envelope material may include reinforcing fibers, such as aramid fibers, to provide puncture resistance. The reinforcing material may be used in combination with other polymers, or the entire envelope may be formed from such a polymer, e.g., a woven fabric of aramid fibers. In one embodiment, the envelope may include one or two polymer films, e.g., PET films, arranged around two planar sides of the aerogel composition. In some embodiments, a frame, for example, made of silicone rubber, may be arranged around the edges of the flexible insulating member and the envelope to seal the envelope and facilitate handling of the resulting composite insulating structure.

[0178] Alternatively or additionally, the composite insulating structure may include several layers of flexible insulating material laminated on top of each other. Optionally, the layers may be separated by any of the materials described above in relation to an envelope. Alternatively or additionally, the layers may be separated by foam pads or mica sheets to further improve insulating performance. Alternatively or additionally, such layers may be used on the outside of the composite insulating structure. In some embodiments, it may be desirable to include a thermal conductive material configured in a controlled manner, for example, to transport heat to a heat sink. The various layers may be bonded to each other by any suitable adhesive known to those skilled in the art, or by needling, or by enclosing them by an envelope to maintain the laminated structure.

[0179] Alternatively or additionally, the flexible insulating member may include a coating. For example, a polymer or prepolymer solution or emulsion may be sprayed, painted, cast, or otherwise coated onto one or more outer surfaces of the flexible insulating member or the composite insulating structure and cured. Suitable cured polymers include polyolefins, silicones, polyvinyl alcohol, starch, polytetrafluoroethylene, phenols, melamine, phenol formaldehyde, acrylic polymers, and other polymers known to those skilled in the art. Such coatings can provide functionality similar to the envelopes described above, but with less material. Alternatively or additionally, the flexible insulating member may be surface treated, for example, hydrophobized. The flexible insulating member may be contacted with a hydrophobizing agent such as a silane compound, a silazane compound, a disiloxane compound, etc. Examples of silane compounds include alkyl halosilanes having the formula R ’ x SiX 4-x and alkoxysilanes having the formula R ’ x Si(OR ’’ ) 4-x , where in the formula, R ’ is selected from the group consisting of C1-C 10 branched and straight-chain alkyl or alkenyl, C3-C 10 cycloalkyl, and C6-C 10 aryl, R ’’ is C1-C5 branched or straight-chain alkyl, X is a halogen, preferably chlorine, and x is an integer from 1 to 3. The flexible insulating member may be immersed directly in the hydrophobizing agent or exposed to the vapor of the hydrophobizing agent. Alternatively, the flexible insulating member may be immersed in a mixture of the hydrophobizing agent and a suitable solvent. The temperature and pH of the treatment medium can be adjusted as known to those skilled in the art to manipulate the degree of treatment. Exemplary treatment agents include, but are not limited to, trimethylchlorosilane, dimethyldichlorosilane, hexamethyldisilazane, hexamethyldisiloxane, and other hydrophobizing agents known to those skilled in the art. The hydrophobizing agent is preferably water-soluble and / or has a boiling point of less than 200 °C, less than 150 °C, or preferably less than 100 °C.

[0180] The present invention includes the following aspects / embodiments / features in any order and / or any combination. 1. The present invention relates to a flexible insulating member comprising a layer which is a mat containing a second fibrous component, and a preformed aerogel and a first fibrous component dispersed in the mat, wherein the flexible insulating member is flame retardant according to UL94 V0, has a thermal conductivity of less than 40 mW / m·K at 25°C, and has a thickness of at least 0.3 mm. 2. A flexible insulating member according to any of the preceding or following embodiments / features / aspects, wherein the mat has a thickness and pores throughout its entire thickness, and the aerogel and first fibrous components fill / occupy at least 50% of the pores over at least 90% of the thickness of the mat. 3. The flexible insulating member according to any of the preceding or following embodiments / features / aspects, wherein the mat is itself breathable, and the breathability is reduced by at least 50% after the preformed aerogel and the first fibrous component are dispersed in the mat. 4. A flexible insulating member according to any of the preceding or following embodiments / features / aspects, wherein the preformed aerogel and the first fibrous component are completely dispersed below the upper surface of the mat. 5. Alternatively or additionally, the present invention relates to a flexible insulating member, A first layer comprising an aerogel and a first fibrous component, A second layer is a mat containing a second fibrous component, and comprises The present invention relates to a flexible insulating member comprising a first layer and a second layer bonded together, wherein the flexible insulating member is flame-retardant according to UL94 V0, has a thermal conductivity of less than 40 mW / m·K at 25°C, and has a thickness of at least 0.3 mm. 6. A flexible insulating member according to any of the preceding or following embodiments / features / aspects, wherein the flexible insulating member is a blanket, pad, or sheet. 7. A flexible insulating member according to any of the preceding or following embodiments / features / aspects, wherein the first layer and the second layer are bonded together such that they have a peel force of at least 0.1 kgf / cm³. 8. A flexible insulating member having a tensile strength of at least 10 N, as described in any of the preceding or following embodiments / features / appearances. 9. A flexible insulating member having a tensile strength of approximately 10N to 70N, as described in any of the preceding or following embodiments / features / appearances. 10. The aerogel is a flexible insulating member according to any of the preceding or following embodiments / features / appearances, wherein the aerogel is aerogel particles. 11. The aerogel particles are hydrophobic aerogel particles, as described in any of the preceding or following embodiments / features / appearances of the flexible insulating member. 12. The mat is a woven mat or a nonwoven mat, a flexible insulating member according to any of the preceding or following embodiments / features / appearances. 13. The second layer is a flexible insulating member according to any of the preceding or following embodiments / features / aspects, having porosity and / or random openings or voids. 14. A flexible insulating member according to any of the preceding or following embodiments / features / aspects, wherein the first layer has a weight ratio of aerogel to the first fibrous component of 10:1 to 1:10 as a wet slurry before wet laying. 15. A flexible insulating member according to any of the preceding or following embodiments / features / aspects, wherein the first fibrous component includes glass fibers, ceramic fibers, polymer fibers, carbon fibers, or any combination thereof. 16. A flexible insulating member according to any of the preceding or following embodiments / features / aspects, wherein the mat or first layer in which the aerogel is dispersed further comprises at least one binder and has a weight ratio of aerogel to binder of 50:1 to 1:1 as a wet slurry before being wet-laid. 17. A flexible insulating member according to any of the preceding or following embodiments / features / aspects, wherein the mat or first layer in which the aerogel is dispersed further comprises at least one flocculant and has a weight ratio of aerogel to flocculant of 5:1 to 1:1 as a wet slurry before being wet-laid. 18. A flexible insulating member according to any of the preceding or following embodiments / features / aspects, wherein the mat or first layer in which the aerogel is dispersed further comprises at least one viscosity modifier and has a weight ratio of aerogel to viscosity modifier of 5:1 to 1.5:1 as a wet slurry before being wet-laid. 19. A flexible insulating member according to any of the preceding or following embodiments / features / aspects, wherein the first layer and the second layer are bonded to each other by a portion of the first layer that penetrates, intertwines with, or is embedded in a portion of the second layer, and / or by chemical adhesion between a portion of the first layer and a portion of the second layer. 20. A flexible insulating member according to any of the preceding or following embodiments / features / appearances, having a thickness of 0.3 mm to 20 mm. 21. The second layer is a flexible insulating member according to any of the preceding or following embodiments / features / appearances, wherein the second layer has a thickness of 0.1 mm to 10 mm in at least a portion of the second layer. 22. A flexible insulating member according to any of the preceding or following embodiments / features / appearances, wherein the first layer and the second layer are bonded to each other without a separate adhesive layer. 23. A flexible insulating member according to any of the preceding or following embodiments / features / aspects, wherein, based on the dry weight of the mat or first layer, the aerogel particles are present in a mat or first layer in an amount of 10% to 90% by weight, and the first fibrous components are present in an amount of 10% to 90% by weight. 24. The first layer is a nonwoven fabric layer, the flexible insulating member according to any of the preceding or following embodiments / features / appearances. 25. The first layer is a wet-laid nonwoven fabric layer, the flexible insulating member according to any of the preceding or following embodiments / features / appearances. 26. A flexible insulating member according to any of the preceding or following embodiments / features / aspects, wherein the mat or first layer in which the aerogel is dispersed further comprises at least one polymer, at least one metal oxide, and at least one inorganic particle other than a metal oxide. 27. The flexible insulating member according to any of the preceding or following embodiments / features / appearances, wherein the flocculant is a polymeric organic flocculant or an inorganic salt of a polyvalent metal. 28. A flexible insulating member according to any of the preceding or following embodiments / features / aspects, wherein the mat or first layer in which the aerogel is dispersed further comprises at least one IR opacifying agent. 29. A flexible insulating member according to any of the preceding or following embodiments / features / aspects, wherein at least one IR opacifying agent is carbon black, alumina, graphite, titanium dioxide, iron oxide, silicon carbide, or zirconium dioxide, or any combination thereof. 30. The aerogel particles have a particle size in the range of 0.01 mm to 5 mm, for example, 0.1 mm to 4 mm, 0.1 mm to 1.5 mm, or 1 mm to 4 mm, as described in any of the preceding or following embodiments / features / appearances of the flexible insulating member. 31. A flexible insulating member according to any of the preceding or following embodiments / features / aspects, wherein the aerogel particles have a porosity of more than about 60% and a density of less than about 0.4 g / cc, or a density of about 0.05 to about 0.15 g / cc. 32. A flexible insulating member according to any of the preceding or following embodiments / features / appearances, wherein the aerogel has a thermal conductivity of less than approximately 40 mW / m·K, less than approximately 25 mW / m·K, or approximately 12 mW / m·K to approximately 18 mW / m·K, or lower. 33. A flexible insulating member according to any of the preceding or following embodiments / features / appearances, wherein the aerogel has a calorie content of less than 10 MJ / kg, less than 8 MJ / kg, less than 7 MJ / kg, or less than 6 MJ / kg. 34. The flexible insulating member according to any one of the prior claims, wherein the first fibrous component comprises ceramic wool and / or polymer fibers. 35. The flexible insulating member according to any one of the prior claims, wherein the first fibrous component is present in an amount of 10% to 60% by weight, based on the total dry weight of the mat or the first layer. 36. A flexible insulating member comprising the first layer and the second layer, as described in any of the preceding or following embodiments / features / appearances. 37. Alternatively or additionally, the present invention relates to a method for forming a flexible insulating member described in any of the preceding or following embodiments / features / aspects, comprising: a) forming a slurry of a composition comprising an aerogel and a first fibrous component; b) pouring the slurry onto a mat or a second layer in a wet-laid process to obtain either a first layer on the second layer or a single layer; and c) drying the first layer and the second layer or the single layer. 38. The method is one of the preceding or following embodiments / features / aspects, further comprising agglomerating the slurry before step b). 39. Alternatively or additionally, the present invention relates to a composite insulating structure, A first layer comprising a flexible insulating member described in any of the preceding or following embodiments / features / aspects, A second layer comprising aerogel and fibers, The present invention relates to a composite insulating structure in which one of the first and second layers contains 0.5 to 10% by weight of a carbonaceous IR opacifier, the other of the first and second layers contains less than 0.5% by weight of a carbonaceous IR opacifier, and the second layer optionally includes a flexible insulating member having a different composition from the flexible insulating member of the first layer. 40. A composite insulating structure according to any of the preceding or following embodiments / features / aspects, wherein one of the first and second layers contains 0.5 to 10% by weight of a carbonaceous IR opacifier, and the other of the first and second layers does not contain a carbonaceous IR opacifier. 41. The carbonaceous IR opacifier is selected from the group consisting of carbon black, activated carbon, carbon aerogel, carbon xerogel, carbon fiber, recycled carbon from the thermal decomposition of carbon black-filled plastics or elastomers, and partially carbonized polymer fibers, and combinations thereof, in the composite insulating structure described in any of the preceding or following embodiments / features / aspects. 42. The carbonaceous IR opacifier is carbon black, in the composite insulating structure according to any of the preceding or following embodiments / features / aspects. 43. A composite insulating structure according to any of the preceding or following embodiments / features / aspects, further comprising a third layer containing an aerogel, fibers, and less than 0.5% by weight of a carbonaceous IR opacifier. 44. A carbonaceous IR opacifying agent is independently selected for each layer in the composite insulating structure described in any of the preceding or following embodiments / features / aspects. 45. Alternatively or additionally, the present invention relates to a series of battery cells, the series comprising a plurality of battery cells electrically connected to one another, at least a portion of the battery cells being separated from each other by at least one thermal barrier, the thermal barrier comprising a flexible insulating member as described in the preceding or any of the following embodiments / features / aspects.

[0181] The present invention can be further described by the following non-limiting embodiments. [Examples]

[0182] Example 1

[0183] Experiments were conducted to evaluate the properties and / or performance of several multilayer flexible insulating materials, including a nonwoven first layer and a fiberglass mat as a second layer.

[0184] The blanket was produced by the wet-laid process described below. One liter of water was mixed in a WARING benchtop heavy-duty blender with a dispersant (Jeffamine M2070, Huntsman), a rheology modifier (Nalclear 71605, Nalco), and an antifoaming agent (Crucible Chemical) Foamkill® 830, and mixed at high shear for 10 seconds.

[0185] Ceramic fibers (Fiberfrax® 7001 C5 ceramic fibers, Unifrax, high-purity coarsely cut product with an average fiber diameter of 1.5-2.5 microns and a fiber index of 45-55% as measured by conical elutriation), aramid fibers (3 mm, Endnus New Material (Dongguan) Co., Ltd.), glass fibers (E-06-F, Unifrax), P200 aerogel particles (Cabot Corporation), 44 micron rutile titania sand (Loudwolf), F600 6 micron silicon carbide (Sturbridge Metallurgical Services), and aluminum trihydrate (ATH, Sigma-Aldrich) were added to a WARING heavy-duty blender in the amounts listed in Table 1. The mixtures in the blender were mixed at high shear (15,000 rpm) for 20 seconds to form a paste-like dispersion. Acrylic binder (Novacryl PSR 300, Synthomer) and silicone binder (Dowsil HV 496 resin, Dow) were added to a blender and mixed under high shear for a further 20 seconds to prepare a slurry. The slurry was transferred to a pitcher. To destabilize the slurry system, a flocculant (Sigma-Aldrich polydiallyldimethylammonium chloride (PDADMAC)) was added to the slurry to generate the amounts of flocs listed in Table 1. The slurry was then poured onto a 7-inch circular molding wire with a continuous strand bale (FIBREGLAST). The molding wire was then passed under vacuum to remove excess water from the aerogel flocs.

[0186] The sample was rolled in a metal cylinder to extrude some of the water and pack the various components more compactly, and then dried in an oven at 120°C for about 15 minutes.

[0187] The thickness of the sample was measured using a thickness gauge.

[0188] The thermal conductivity was measured using a LaserComp Heat Flow Meter instrument according to ASTM C518. When the sample was too thin to measure, the sample was supported with a shim, and the thermal conductivity of the resulting structure (shim + blanket) was determined. The thermal conductivity of this structure was then compared to the thermal conductivity of the shim alone to obtain the thermal conductivity of the blanket itself.

[0189] Flammability was measured according to the UL94 standard.

[0190] The blanket was made using the following formula (all amounts in grams):

[0191] [Table 1]

[0192] These thin blankets achieved good thermal conductivity for their thickness and were considered stronger than materials fabricated without a second layer. See Table 2.

[0193] Tensile strength was determined using an Instron instrument with a 2-inch x 6-inch test specimen, which was pulled at a speed of 20 mm / min using the tensile method indicated by the Instron instrument.

[0194] [Table 2]

[0195] In these examples, the blanket exhibited good adhesion to the glass web (second layer). Under UL94 testing, the flame propagated across the entire height of the sample when the glass web alone was used.

[0196] These results support the possibility that aerogel particles can make nonwoven blankets into excellent thermal barriers for use in Li-ion battery cells or packs, potentially reducing heat transfer during thermal runaway events.

[0197] While the present invention has been specifically shown and described with reference to its preferred embodiments, it will be understood by those skilled in the art that various modifications in form and detail can be made without departing from the scope of the invention as encompassed by the appended claims.

[0198] Where used herein, the terms "and / or" include any and all combinations of one or more of the enumerated items associated with them. Furthermore, all conjunctions used should be understood in the most comprehensive sense possible. Thus, the word "or" should be understood to have the definition of "logical disjunction" rather than "exclusive disjunction" unless the context clearly requires something else. Additionally, the singular forms and the articles "a," "an," and "the" are intended to include the plural forms unless otherwise specified. It will be further understood that, where used herein, the terms "includes," "comprises," "including," and / or "comprising" indicate the existence of the described features, requirements, processes, operations, elements, and components, but do not exclude the existence or addition of one or more other features, requirements, processes, operations, elements, components, and groups thereof. Furthermore, if an element containing a component or subsystem is mentioned and / or indicated as being connected to or coupled to another element, it will be understood that it may be directly connected to or coupled to the other element, or that intervening elements may exist.

[0199] Terms such as “first,” “second,” etc., are used herein to describe a variety of elements, but it will be understood that these elements should not be limited by these terms. These terms are used solely to distinguish one element from another. Thus, the elements discussed below may be referred to as the second element, and similarly, the second element may be referred to as the first element without departing from the teachings of the present invention.

[0200] Unless otherwise specified, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant art, and it will be further understood that they should not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0201] The applicants specifically incorporate the entire contents of all cited documents into this disclosure. Furthermore, where a quantity, concentration, or other value or parameter is presented as a range, a preferred range, or a list of preferred upper and lower limits, this should be understood as specifically disclosing all ranges formed from any pair of any upper or preferred value and any lower or preferred value of any range, regardless of whether the range is disclosed separately. Where a numerical range is described herein, unless otherwise specified, the range is intended to include its endpoints, as well as all integers and fractions within that range. The range of the present invention is not intended to be limited to any specific values ​​enumerated when defining a range. For any range provided herein, the numerical range may be "approximately" these ranges, and vice versa, and where a range is provided using the term "approximately", these ranges may be precisely the numerical range provided. Any combination of the embodiments, and / or components, and / or constituents, and / or properties described herein can be constructed herein and are considered part of the present invention.

[0202] Other embodiments of the present invention will be apparent to those skilled in the art from the discussion herein and the practice of the present invention disclosed herein. This specification and the examples are merely illustrative, and the true scope and spirit of the present invention are intended to be shown by the following claims and equivalents.

Claims

1. A flexible insulating member comprising a layer which is a mat containing a second fibrous component, and a pre-formed aerogel and a first fibrous component dispersed in the mat, wherein the flexible insulating member is flame retardant according to UL94 V0, has a thermal conductivity of less than 40 mW / m·K at 25°C, and has a thickness of at least 0.3 mm.

2. The flexible insulating member according to claim 1, wherein the mat has a thickness and pores extending over the entire thickness, and the aerogel and the first fibrous component fill / occupy at least 50% of the pores extending over at least 90% of the thickness of the mat.

3. The flexible insulating member according to claim 1 or 2, wherein the mat itself is breathable, and the breathability is reduced by at least 50% after the preformed aerogel and the first fibrous component are dispersed in the mat.

4. The flexible insulating member according to any one of claims 1 to 3, wherein the preformed aerogel and the first fibrous component are completely dispersed below the upper surface of the mat.

5. A flexible insulating member, A first layer comprising an aerogel and a first fibrous component, A second layer is a mat containing a second fibrous component, The first layer and the second layer are bonded together, and the flexible insulating member is flame retardant according to UL94 V0, has a thermal conductivity of less than 40 mW / m·K at 25°C, and has a thickness of at least 0.3 mm.

6. The flexible insulating member according to any one of claims 1 to 5, wherein the flexible insulating member is a blanket, a pad, or a sheet.

7. The first layer and the second layer have a density of at least 0.1 kgf / cm². ３ The flexible insulating members according to claim 5 or 6, which are bonded together to have a peeling force.

8. The flexible insulating member according to any one of claims 5 to 7, wherein the second layer is porous and / or has random openings or voids.

9. The flexible insulating member according to any one of claims 5 to 8, wherein the first layer and the second layer are bonded to each other by a portion of the first layer that penetrates, intertwines with, or is embedded in a portion of the second layer, and / or by chemical adhesion between a portion of the first layer and a portion of the second layer.

10. The flexible insulating member according to any one of claims 5 to 9, wherein the second layer has a thickness of 0.1 mm to 10 mm in at least a portion of the second layer.

11. The flexible insulating member according to any one of claims 5 to 10, wherein the first layer and the second layer are bonded to each other without a separate adhesive layer.

12. The flexible insulating member according to any one of claims 5 to 11, wherein the first layer is a nonwoven fabric layer.

13. The flexible insulating member according to any one of claims 5 to 12, wherein the first layer is a wet-laid nonwoven fabric layer.

14. A flexible insulating member according to any one of claims 5 to 13, comprising the first layer and the second layer.

15. A flexible insulating member according to any one of claims 1 to 14, having a tensile strength of at least 10 N.

16. A flexible insulating member according to any one of claims 1 to 15, having a tensile strength of approximately 10 N to 70 N.

17. The flexible insulating member according to any one of claims 1 to 16, wherein the aerogel is aerogel particles.

18. The flexible insulating member according to claim 17, wherein the aerogel particles are hydrophobic aerogel particles.

19. The flexible insulating member according to any one of claims 1 to 18, wherein the mat is a woven fabric mat or a nonwoven fabric mat.

20. The flexible insulating member according to any one of claims 1 to 19, wherein the first layer has a weight ratio of aerogel to a first fibrous component of 10:1 to 1:10 as a wet slurry before wet laying.

21. The flexible insulating member according to any one of claims 1 to 20, wherein the first fibrous component includes glass fiber, ceramic fiber, polymer fiber, carbon fiber, or any combination thereof.

22. The flexible insulating member according to any one of claims 1 to 21, wherein the mat or the first layer in which the aerogel is dispersed further comprises at least one binder and has a weight ratio of aerogel to binder of 50:1 to 1:1 as a wet slurry before wet laying.

23. The flexible insulating member according to any one of claims 1 to 22, wherein the mat or the first layer in which the aerogel is dispersed further comprises at least one flocculant and has a weight ratio of aerogel to flocculant of 5:1 to 1:1 as a wet slurry before wet laying.

24. The flexible insulating member according to any one of claims 1 to 23, wherein the mat or the first layer in which the aerogel is dispersed further comprises at least one viscosity modifier and has a weight ratio of aerogel to viscosity modifier of 5:1 to 1.5:1 as a wet slurry before wet laying.

25. The flexible insulating member according to any one of claims 1 to 24, wherein the thickness is 0.3 mm to 20 mm.

26. A flexible insulating member according to any one of claims 1 to 25, wherein in the mat or the first layer in which the aerogel is dispersed, the aerogel particles are present in an amount of 10% to 90% by weight, and the first fibrous component is present in an amount of 10% to 90% by weight, based on the dry weight of the mat or the first layer.

27. The flexible insulating member according to any one of claims 1 to 26, wherein the mat or the first layer in which the aerogel is dispersed further comprises at least one polymer, at least one metal oxide, and at least one inorganic particle other than a metal oxide.

28. The flexible insulating member according to claim 27, wherein the flocculant is a polymeric organic flocculant or an inorganic salt of a polyvalent metal.

29. The flexible insulating member according to any one of claims 1 to 28, wherein the mat or the first layer in which the aerogel is dispersed further comprises at least one IR opacifying agent.

30. The flexible insulating member according to claim 29, wherein the at least one IR opacifying agent is carbon black, alumina, graphite, titanium dioxide, iron oxide, silicon carbide, or zirconium dioxide, or any combination thereof.

31. The flexible insulating member according to any one of claims 1 to 30, wherein the aerogel particles have a particle size in the range of 0.01 mm to 5 mm, for example, 0.1 mm to 4 mm, 0.1 mm to 1.5 mm, or 1 mm to 4 mm.

32. The flexible insulating member according to any one of claims 1 to 31, wherein the aerogel particles have a porosity of more than about 60% and a density of less than about 0.4 g / cc, or a density of about 0.05 to about 0.15 g / cc.

33. The flexible insulating member according to any one of claims 1 to 32, wherein the aerogel has a thermal conductivity of less than about 40 mW / m·K, less than about 25 mW / m·K, or about 12 mW / m·K to about 18 mW / m·K, or lower.

34. The flexible insulating member according to any one of claims 1 to 33, wherein the aerogel has a calorie content of less than 10 MJ / kg, less than 8 MJ / kg, less than 7 MJ / kg, or less than 6 MJ / kg.

35. The flexible insulating member according to any one of claims 1 to 34, wherein the first fibrous component comprises ceramic wool and / or polymer fibers.

36. The flexible insulating member according to any one of claims 1 to 34, wherein the first fibrous component is present in an amount of 10% to 60% by weight based on the total dry weight of the mat or the first layer.

37. A method for forming a flexible insulating member according to any one of claims 1 to 36, comprising: a) forming a slurry of a composition comprising the aerogel and the first fibrous component; b) pouring the slurry onto the mat or the second layer in a wet laid process to obtain the first layer on the second layer or a single layer; and c) drying the first layer and the second layer or the single layer.

38. The method according to claim 38, further comprising agglomerating the slurry before step b).

39. A composite insulating structure, A first layer comprising a flexible insulating member according to any one of claims 1 to 37, A second layer comprising aerogel and fibers, A composite insulating structure comprising: one of the first layer and the second layer containing 0.5 to 10% by weight of a carbonaceous IR opacifier; the other of the first layer and the second layer containing less than 0.5% by weight of a carbonaceous IR opacifier; and the second layer optionally containing a flexible insulating member having a different composition from the flexible insulating member of the first layer.

40. The composite insulating structure according to claim 39, wherein one of the first layer and the second layer contains 0.5 to 10% by weight of a carbonaceous IR opacifier, and the other of the first layer and the second layer does not contain a carbonaceous IR opacifier.

41. The composite insulating structure according to claim 39 or 40, wherein the carbonaceous IR opacifier is selected from the group consisting of carbon black, activated carbon, carbon aerogel, carbon xerogel, carbon fiber, recycled carbon from the thermal decomposition of carbon black-filled plastics or elastomers, and partially carbonized polymer fibers, and combinations thereof.

42. The composite insulating structure according to any one of claims 39 to 41, wherein the carbonaceous IR opacifying agent is carbon black.

43. A composite insulating structure according to any one of claims 39 to 42, further comprising a third layer containing an aerogel, fibers, and less than 0.5% by weight of a carbonaceous IR opacifying agent.

44. The composite insulating structure according to any one of the claims, wherein the carbonaceous IR opacifying agent is independently selected for each layer.

45. A series of battery cells, the series comprising a plurality of battery cells electrically connected to one another, wherein at least a portion of the battery cells are separated from each other by at least one thermal barrier, the thermal barrier comprising a flexible insulating member as described in any one of claims 1 to 44.

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