Thermal barrier articles for rechargeable electrical energy storage systems

Abstract

The thermal barrier article of the present invention comprises a multilayer material including a first fiber layer disposed on a first side of a ceramic layer and a second fiber layer disposed on the opposite side of the ceramic layer. The thermal barrier article may also include an alternating arrangement of multiple fiber layers and ceramic layers. In each of these embodiments, the thermal barrier article has sufficient flexibility and thermal properties to withstand a bending adjustment test and a pyrotechnic impact test having a temperature of at least 1200°C and releasing a non-negligible amount of particles.

Description

[Technical Field]

[0001] The present invention relates to the use of a multilayer material as a barrier article in a rechargeable electrical energy storage system, for example, which includes multiple single rechargeable battery cells, battery cell modules, or battery cell module packs.

[0002] The present invention also relates to batteries for electric vehicles, and more particularly to explosion-proof and heat-insulating barrier articles for managing thermal runaway events in battery cells / modules / packs. Furthermore, the articles provided may be particularly useful in automotive, aircraft, marine, and stationary energy storage applications. [Background technology]

[0003] Rechargeable or rechargeable batteries or rechargeable electrical energy storage systems, including multiple single battery cells, such as lithium-ion cells, are well known and are used in several technical fields as power sources for mobile phones, portable computers, electric vehicles or vehicles, hybrid vehicles, and the like.

[0004] Furthermore, it is known that rechargeable battery cells, such as lithium-ion cells, can experience internal overheating due to events such as short circuits within the cell, improper use of the cell, manufacturing defects, or exposure to extreme external temperatures. This internal overheating can lead to so-called "thermal runaway," where high temperatures increase the reaction rate within the cell, generating more heat than can be removed, which in turn increases the reaction rate, resulting in the generation of even more heat. In a typical lithium-ion battery configuration, for example, the heat generated in such a defective cell can reach 500°C to 1000°C, and even higher temperatures in localized hot spots.

[0005] Batteries for next-generation electric vehicles (EVs) are higher energy than those currently in use. High-energy batteries with similar energy densities, such as those designated as 811 (NMC, i.e., nickel-manganese-cobalt ratio), can fail catastrophically if punctured or overheated. When such an event occurs, the subsequent battery fire can reach over 1200°C and may also release fragments at a moderately high speed. Battery packs are generally housed in aluminum shells, but since aluminum melts at 660°C, the shell needs to be protected from flames and fragments caused by battery failure, and time must be given for occupants of the electric vehicle to exit if such a failure occurs. Battery packs may also be housed in fiber-reinforced polymer composites, which, like aluminum, can be destroyed at high temperatures.

[0006] While materials exist that can withstand high-temperature flames (i.e., those that can withstand exposure to flames exceeding 1200°C for several tens of minutes without being destroyed), these materials cannot withstand the explosions that accompany thermal runaway events in high-energy batteries. The significant risks posed by the propagation of thermal runaway necessitate the design of battery modules featuring explosion-proof and heat-insulating barriers to mitigate the effects of such thermal runaway and to ensure sufficient time for occupants to safely evacuate in the event of a fire. [Overview of the project]

[0007] As mentioned above, there is still a need for appropriate materials and placement that provide insulation and help prevent or mitigate damage to adjacent materials and areas from explosive particles generated by a faulty battery pack. There is also a need for such appropriate materials that are easy to use in the assembly process and provide flexibility in the design of rechargeable electrical energy storage systems.

[0008] The present invention provides a thermal barrier article comprising a multilayer material. The multilayer material comprises a first fiber layer located on a first side of a ceramic layer (also referred herein as a ceramic binder layer) and a second fiber layer located on the opposite side of the ceramic layer. In yet another embodiment, the barrier article may include an alternating arrangement of multiple fiber layers and ceramic layers. In each of these embodiments, the barrier article has sufficient flexibility and thermal properties to withstand both a bending adjustment test and a pyrotechnic impact test. A bending adjustment test is defined herein and simulates a manufacturing process involving multiple windings on a roll or cylinder on a production line. A pyrotechnic impact test is also defined herein and involves exposing the thermal barrier article to a Garb explosion having a temperature of at least 1200°C and releasing a non-negligible amount of particles. The thermal barrier article can withstand the pyrotechnic impact test for at least 2.5 seconds.

[0009] In the first embodiment, the at least one fiber layer includes a woven or nonwoven fiber mat or fiber cloth. In another embodiment, the fiber layer includes inorganic fibers.

[0010] In yet another embodiment, the ceramic layer comprises an inorganic filler and an inorganic binder.

[0011] In yet another embodiment, the inorganic filler may include kaolin clay, metakaolin, talc, mica, mullite, phlogopite, muscovite, montmorillonite, smectite, bentonite, illite, chlorite, sepiolite, attapulgite, halloysite, vermiculite, laponite, rectolite, perlite, fly ash, fumed silica, silica fume, Portland cement, or concrete mixtures.

[0012] In one embodiment, the inorganic binder may include materials used to bind sodium silicate, potassium silicate, lithium silicate, calcium silicate, colloidal silica, water, and other similar inorganic fillers.

[0013] In yet another embodiment, the ceramic layer may further contain a low concentration of severed organic fibers consisting of PVA, polypropylene, polyolefin blends or copolymers, nylon, and blends thereof.

[0014] In another embodiment, the fiber layers of the multilayer material may be identical throughout the multilayer material in at least one of the composition and thickness. In yet another embodiment, the fiber layers of the multilayer material may contain different materials and / or have different thicknesses in some or all of the fiber layers.

[0015] In yet another embodiment, the ceramic layers of the multilayer material may be identical throughout the multilayer material in at least one of the composition and thickness. In yet another embodiment, the ceramic layers of the multilayer material may contain different materials and / or have different thicknesses in some or all of the multiple ceramic layers.

[0016] In yet another embodiment, the at least one fiber layer includes a woven or nonwoven fiber mat or fiber cloth containing a plurality of fibers selected from the group consisting of A glass, C glass, D glass, E glass, M glass, R glass, S glass, ECR glass, AR glass, basalt fibers, silicate fibers (e.g., Astroquartz fibers), silicon carbide fibers, ceramic fibers (e.g., Nextel fibers), or other inorganic fibers.

[0017] In yet another embodiment, the at least one fiber layer comprises a ceramic or mineral composition consisting of basalt, alumina, aluminoborosilicate, Nextel, silicon carbide, quartz, and combinations thereof.

[0018] In yet another embodiment, the at least one fiber layer comprises a coating having an alkali-resistant composition, and in yet another embodiment, the alkali-resistant composition comprises calcium silicate.

[0019] In yet other embodiments, the barrier article further includes an adhesive layer applied to the outer surface of at least one fibrous layer. In yet other embodiments, the adhesive layer includes any one of a thermosetting adhesive, a B-stage adhesive, a hot melt adhesive, a pressure sensitive adhesive, a solvent-based adhesive, or an aqueous-based adhesive.

[0020] In yet other embodiments, the thermal barrier article has at least 5 firework resistance efficiency values and is operatively adapted to withstand the impact of a large amount of explosive particles at extremely high temperatures of at least 1200 °C (and / or well above 1200 °C) over a long period of time.

[0021] In yet other embodiments, the present invention provides a battery housing for an electric vehicle that includes at least one battery cell or battery assembly and the thermal barrier article described above.

[0022] In yet other embodiments, a method of preventing or at least reducing further dispersion of explosive fragments within or from an electric vehicle battery assembly includes providing at least one battery cell of the electric vehicle battery assembly with the thermal barrier article described above.

[0023] Protecting against risks associated with sudden thermal runaway events in electric vehicle batteries is an important technical challenge.

[0024] Embodiments of the present invention address the challenges associated with conventional materials by providing explosion-resistant and heat-resistant barrier articles that combine relatively thin and flexible multilayer materials. The structure may include a multilayer material comprising at least one fiber layer and at least one ceramic layer, with an adhesive layer disposed on the outer surface of the fiber layer (opposite the ceramic layer), a multilayer material in which the first and second fiber layers are disposed on both sides of the ceramic layer, or a multilayer material in which multiple fiber layers and ceramic layers are arranged alternately. Each fiber layer may include a woven or nonwoven fiber mat or fiber cloth containing inorganic fibers, and each ceramic layer may include an inorganic filler and an inorganic binder. The flexible structures disclosed herein provide explosion-resistant and heat-resistant barrier articles that are operationally adapted to withstand pyrotechnic shock tests that release temperatures far exceeding 1200°C and a significant amount of particles for at least 2.5 seconds. [Brief explanation of the drawing]

[0025] The present invention will be described in further detail by illustrating specific embodiments of the invention with reference to the following drawings.

[0026] [Figure 1A] Figure 1A is a schematic cross-sectional view of an example barrier article according to an embodiment of the present invention.

[0027] [Figure 1B] Figure 1B is a schematic cross-sectional view of an example barrier article according to an embodiment of the present invention.

[0028] [Figure 1C] Figure 1C is a schematic cross-sectional view of an example barrier article according to an embodiment of the present invention.

[0029] [Figure 1D] Figure 1D is a schematic cross-sectional view of an example barrier article according to an embodiment of the present invention.

[0030] [Figure 2] Figure 2 is a schematic diagram of the battery compartment of an example electric vehicle.

[0031] [Figure 3] Figure 3 shows probability plots of the difference from the mean for 11 non-bent, non-flexible sample structures ("As-Is structures") and 11 bent or flexible sample structures ("Bend-Flex structures").

[0032] The repeated use of reference numerals in the specification and drawings is intended to represent identical or similar features or elements of the disclosure. Those skilled in the art should understand that numerous other modifications and embodiments can be devised within the scope of this disclosure. Drawings may not necessarily be drawn to scale. [Modes for carrying out the invention]

[0033] As used herein, the term “operatally adapted” refers to a structure that is designed, configured, and / or dimensioned to perform a particular operation or performance.

[0034] As used herein, the terms “preferred” and “preferably” refer to embodiments described herein that may offer certain advantages under specific circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unhelpful, nor is it intended to exclude other embodiments from the scope of the invention.

[0035] In this specification and the appended claims, the singular forms "a," "an," and "the" are to be interpreted as including multiple subjects unless the context clearly indicates otherwise. Therefore, for example, a reference to "a" or "the" component may include one or more components and their equivalents known to those skilled in the art. Furthermore, the terms "and / or" mean one or all of the enumerated elements, or any combination of two or more of them.

[0036] It should be noted that "comprises" and its variations, when appearing herein, do not have a restrictive meaning. Furthermore, "a," "an," "the," "at least one," and "one or more" are used interchangeably herein. Relative terms such as left, right, front, rear, up, down, side, upper, lower, horizontal, and vertical may be used, but these refer to the viewpoint observed in a particular drawing. These terms are used solely for the purpose of simplifying the explanation and do not limit the scope of the invention in any way.

[0037] Throughout this specification, the terms “one embodiment,” “a particular embodiment,” “one or more embodiments,” or “embodiment” mean that certain features, structures, materials, or properties described in relation to such embodiment are included in at least one embodiment of the present invention. Therefore, where phrases such as “in one embodiment,” “a particular embodiment,” “one or more embodiments,” or “in an embodiment” appear, they do not necessarily refer to the same embodiment.

[0038] According to one embodiment of the present invention, a thermal barrier article (also referred to simply as a barrier article) comprises a multilayer material including at least one fiber layer and at least one ceramic layer. Optionally, an adhesive can be applied to the fiber layer (opposite the ceramic layer). In another embodiment, the barrier article may include a first fiber layer located on a first side of the ceramic layer (also referred to herein as a ceramic binder layer) and a second fiber layer located on the opposite side of the ceramic layer. In yet another embodiment, the barrier article may include an alternating arrangement of multiple fiber layers and ceramic layers. In each of these embodiments, the barrier article has sufficient flexibility to withstand a bending adjustment test and sufficient thermal barrier properties to withstand a pyrotechnic impact test.

[0039] The bending adjustment test is defined below and simulates a manufacturing process involving multiple windings on a roll or cylinder on a production line. The pyrotechnic shock test or pyrotechnic test is also defined below and involves exposing the heat barrier article to a Garb explosion having a temperature of at least 1200°C and / or well above 1200°C and releasing a non-negligible amount of particles. The heat barrier article must be able to withstand the pyrotechnic shock test for at least 2.5 seconds in very thin structures and at least 6 seconds in thick structures.

[0040] Because the aforementioned multilayer material structure possesses relatively high robustness and resilience, it can be easily processed and handled safely in manufacturing environments without compromising its explosion resistance.

[0041] In the first embodiment, the fiber layer comprises a woven or nonwoven fiber mat or fiber cloth, wherein the woven or nonwoven fiber mat or fiber cloth comprises inorganic fibers. Furthermore, the ceramic layer comprises an inorganic filler and an inorganic binder.

[0042] The multilayer material according to the present invention can be used, for example, to ensure the overall safety of a vehicle equipped with a rechargeable electric energy storage system. The multilayer material may include at least three layers of alternating material compositions. When applied to electric vehicles or hybrid vehicles, the alternating materials need to have an appropriate overall thickness to fit into a potentially constrained deployment space, while still providing sufficient thermal properties and explosion resistance.

[0043] The multilayer material according to the embodiments of the present invention is relatively thin (about 1.5 mm or less), and the overall thickness can be adjusted to be greater depending on the specific application. Furthermore, the multilayer material is relatively lightweight (about 2000-3000 g / m²), but higher or lower weights can be used depending on the specific application and / or requirements.

[0044] To more safely house the battery pack in the event of thermal runaway, the battery housing cover should be protected from flames and debris from a failed battery by a fire-resistant and explosion-resistant lining (sometimes referred to as "underlid" material).

[0045] Suitable materials used as thermal barriers must withstand exposure to high temperatures and pressures accompanied by gas releases and particle ejections without excessive damage. Furthermore, these materials must provide thermal and insulating properties during and after high temperatures, pressures, and gas and / or particle impacts.

[0046] The multilayer materials according to the present invention may be flexible, semi-flexible, or bendable, but this does not impair their resistance to explosion or explosive impact. "Flexibility" means having sufficient resilience and robustness to withstand the bending adjustment tests described herein. The flexibility of the multilayer material ensures sufficient bendability to withstand manufacturing processes involving multiple windings on a roll or cylinder on a production line. This manufacturing suitability expands the applicability and enables more effective use of the material. Specifically, the flexibility of the material makes it possible to bend the material, increasing the options for its application in rechargeable electric energy storage systems.

[0047] The multilayer material according to the present invention may include inorganic fiber fabrics containing A glass, C glass, D glass, E glass, M glass, R glass, S glass, ECR glass, AR glass, basalt fibers, silicate fibers (Astroquartz fibers), silicon carbide fibers, ceramic fibers (e.g., Nextel fibers), other inorganic fibers, or combinations thereof. The fibers may be chemically treated. The inorganic fiber fabric may include, for example, single-layer fabrics, knitted fabrics, entangled fabrics, crocheted fabrics, or multilayer fabrics obtained by sewing, mechanically entangling, or inorganic adhesives to bond woven or nonwoven layers, or combinations thereof.

[0048] In other embodiments, as described above, if the fiber layer includes a woven or nonwoven fiber mat, the other fiber layer may include inorganic particles or inorganic fibers, such as inorganic paper or inorganic board. This layer may include, for example, inorganic insulating paper containing glass fibers and microfibers, i.e., 3M CEQUIN, which is commercially available from 3M Company in St. Paul, Minnesota, USA.

[0049] In other embodiments, at least one fiber layer may be formed from a multilayer structure mechanically joined by stitching or needle punching.

[0050] Each fiber layer can have a thickness ranging from, for example, 0.04 to 1.5 mm, and a thickness of, for example, 0.1 to 0.6 mm. Also, the density can range from 35 to 1500 g / m². 2 The weight may include the following. The diameter of individual filaments may range from approximately 4 to 13 microns. The number of filaments per yarn may vary from approximately 5 to 1000. Typical weaving patterns may include plain weave, basket weave, twill weave, leno weave, four-piece satin weave, eight-piece satin weave, and others common in the industry. The warp and weft may be identical or different in composition.

[0051] In some embodiments, the ceramic layer comprises an inorganic binder and one or more fillers or additives. For example, the fillers may include inorganic materials such as kaolin clay, metakaolin, talc, mica, mullite, phlogopite, muscovite, montmorillonite, smectite, bentonite, illite, chlorite, sepiolite, attapulgite, halloysite, vermiculite, laponite, rectolite, perlite, fly ash, fumed silica, silica fume, Portland cement, concrete mixtures, and combinations thereof. The form of the fillers may include beads, solid particles, crushed powder, flakes, needles, rods, chopped fibers, hollow spheres, hollow tubes, and combinations thereof.

[0052] Examples of clays or aluminosilicates include, but are not limited to, kaolin clay, talc, mica, scheelite, montmorillonite, smectite, bentonite, illite, chlorite, sepiolite, attapulgite, halloysite, laponite, lectolite, perlite, and combinations thereof. Suitable types of kaolin clay include, but are not limited to, water-washed kaolin clay, exfoliated kaolin clay, calcined kaolin clay, and surface-treated kaolin clay.

[0053] Examples of minerals include, but are not limited to, calcite, aragonite, limestone, quartz, sphalerite, colemanite, ferberite, fluorite, gypsum, rutile, and apatite.

[0054] Optionally, flow regulators, endothermic fillers, and mixtures thereof, such as alumina trihydrate and magnesium hydroxide, may be added.

[0055] The inorganic binder may include sodium silicate, potassium silicate, lithium silicate, calcium silicate, colloidal silica, (poly)phosphate, (poly)borate, (poly)aluminate, water, and combinations thereof.

[0056] Optionally, additional organic materials can be added to the ceramic layer composition. Examples include glycerol, polyurethane, polyvinyl alcohol, styrene-butadiene, polystyrene, neoprene, polyvinyl chloride, polyvinyl acetate, acrylonitrile copolymers, acrylic polymers and copolymers, and carbohydrates (e.g., sugars). These additional organic materials may be added in relatively small amounts, up to 5% by weight.

[0057] In some embodiments, the ceramic layers of the multilayer material, or each ceramic layer, may have a thickness of about 0.2 mm to about 1.5 mm.

[0058] The overall thickness of the multilayer material may range from 0.5 mm to 5 mm. In some applications where thinner materials are used, the overall thickness of the multilayer material may range from 0.7 mm to 2 mm. The thickness of the material can be adjusted depending on the application in which it is used. As described above, the material may have flexibility that improves ease of application in the assembly process and helps to withstand shocks and vibrations in automotive or other environments.

[0059] In other embodiments, the ceramic layer may further contain sliced ​​inorganic or organic fibers in a concentration of about 0.2% to about 3% by weight.

[0060] As will be apparent from the description herein, when multiple ceramic layers are used, each ceramic layer may have the same or different composition and / or the same or different thickness.

[0061] In one embodiment, the multilayer material may be formed by first mixing an inorganic binder, an inorganic filler, any cut organic fibers, and any additives. This mixture is applied between two or more fiber layers, for example, by die-coating one fiber layer and then layering a second fiber layer on top of it. The application may be distributed onto one fiber layer and pressed between the two fiber layers in a calender or nip, or by other techniques. During the formation of the multilayer material, certain amounts of binder and / or filler from the ceramic layer may penetrate into one or both adjacent fiber layers. The ceramic layer may be cured or dried in an oven or other suitable apparatus. Optionally, an adhesive may be applied to one or both sides.

[0062] In another embodiment, optionally, the barrier article may further include an adhesive layer applied to the outer surface of at least one fiber layer. The adhesive layer may include any of the following: a thermosetting adhesive, a step B adhesive, a hot melt adhesive, a pressure-sensitive adhesive, a solvent-based adhesive, or a water-based adhesive.

[0063] In another embodiment, one or more fiber layers may be in the form of a tape on which an adhesive layer (e.g., a pressure-sensitive adhesive layer) has already been placed on the fiber layer material.

[0064] In one preferred embodiment, each of the fiber layers comprises a woven or nonwoven glass fiber mat or fiber cloth, and at least one ceramic layer comprises an inorganic filler and an inorganic binder.

[0065] One embodiment of the present invention relates to a rechargeable electrical energy storage system comprising at least one battery cell and a barrier article as described above.

[0066] One embodiment of the multilayer material according to the present invention may be used, for example, as a barrier article that helps to enhance the overall safety of a vehicle equipped with a rechargeable electrical energy storage system.

[0067] The multilayer material may be arranged in a rechargeable electrical energy storage system such that the fiber layer is positioned to face at least one battery cell / pack / module. The fiber layer is selected to have high resistance to temperature and other shocks that may occur during thermal runaway events.

[0068] The rechargeable electrical energy storage system according to the present invention may provide a thermal barrier article disposed between at least one battery cell and the lid of the storage system. The thermal barrier article may, for example, be fixed to the lid, or it may be disposed between the battery cell and the lid. In such a position, the thermal barrier article may be used as an insulating barrier for the lid, or to protect the lid and any systems or components disposed adjacent to the lid. The thermal barrier article may also be used as an insulating barrier for electrical components around the battery cell or battery pack, such as cables or busbars. If the thermal barrier article provides additional electrical insulation properties, short circuits due to deformation or other damage may also be mitigated / prevented. Another possibility is to position the thermal barrier article so as to cover the burst plate of at least one battery cell. Of course, the thermal barrier article may be disposed within the rechargeable electrical energy storage system in a manner that satisfies all of the above requirements. As described above, it may be advantageous to position the thermal barrier article such that the fiber layer faces at least one battery cell, particularly the burst plate of the battery cell.

[0069] Furthermore, the use of the barrier articles according to the present invention is not limited to the use of a specific type of rechargeable electrical energy storage system. For example, they may be used in rechargeable electrical energy storage systems that include prismatic battery cells, pouch cells, or cylindrical cells.

[0070] Furthermore, the use of the barrier articles according to the present invention is not limited to use in a specific type of vehicle.

[0071] Various embodiments of the present invention are described below and shown in the drawings, where similar elements are given the same reference numerals.

[0072] Figures 1A, 1B, 1C, and 1D are schematic cross-sectional views of an example barrier article according to an embodiment of the present invention.

[0073] Figure 1A shows a cross-sectional view of a barrier article 1A according to one embodiment of the present invention. The barrier article 1A in Figure 1A includes first and second fiber layers 2a and 2b and a ceramic layer 3. The fiber layers and ceramic layer may have the compositions described above. In this example, the first fiber layer 2a has a different composition and / or thickness from the second fiber layer 2b. Of course, in other embodiments, the first fiber layer 2a may have the same composition and thickness as the second fiber layer 2b. In other embodiments, as shown in Figure 1B, the barrier article 1B may include alternating layers of fiber layers and ceramic layers. In this example, the barrier article 1B includes four fiber layers (2a, 2b, 2a, 2b) and three ceramic layers 3. Thus, in other embodiments of the present invention, the barrier article may include 2, 3, 4, 5, 6, 7, 8, 9, 10 (or more) fiber layers and 2, 3, 4, 5, 6, 7, 8, 9 (or more) ceramic layers.

[0074] Figure 1C shows a cross-sectional view of a barrier article 1C according to another embodiment of the present invention. In this example, the ceramic layer 3 is located on the first side of the fiber layer 2a. The fiber layer and the ceramic layer may have the compositions described above. An adhesive layer 4 is located on the second (opposite) side or outer surface of the fiber layer 2a. The adhesive layer may have the compositions described above. In another embodiment, the adhesive layer 4 may be located on the ceramic layer 3 opposite to the fiber layer 2a. In yet another embodiment, as shown in Figure 1D, the barrier article 1D includes first and second fiber layers 2a and a ceramic layer 3 located between these first and second fiber layers, with an adhesive layer 4 located on each outer surface of the first and second fiber layers, respectively. In yet another embodiment of the present invention, the barrier article may include 2, 3, 4, 5, 6, 7, 8, 9, 10 (or more) fiber layers and 2, 3, 4, 5, 6, 7, 8, 9 (or more) ceramic layers.

[0075] Figure 2 is a schematic diagram of a rechargeable electrical energy storage system 5. The system includes prismatic battery cells 6. Each of the prismatic battery cells 6 includes a burst plate 7 for releasing potentially generated excess pressure through vent holes, for example, in the event of a thermal runaway event. The cells 6 are arranged within a housing 8 (which is actually closed, but is shown with two open walls—one front wall and one side wall). The housing provides a lid 9.

[0076] As already mentioned above, regulations require that rechargeable energy storage systems be constructed in a manner that prevents external fires. One area that needs to be protected is the area above the burst plate 7. System components located above the burst plate require an insulating barrier to prevent battery burnout and open flames outside the system. According to the present invention, a barrier article, such as one of the barrier articles shown in Figures 1A to 1D, is placed between the battery cell 6 / burst plate 7 and the lid 9.

[0077] Multilayer materials 1a to 1d may also be placed between the cell 6 and the side or bottom wall of the housing 8 (not shown).

[0078] The explosion-proof and thermally insulating barrier articles described herein may, in some embodiments, be effective in mitigating the effects of thermal runaway propagation in lithium-ion batteries. These articles may also be useful in other commercial and industrial applications, such as automotive, electric transport, residential, industrial, marine, and aerospace applications, where it is necessary to protect personnel or surrounding structures from the effects of flying debris or temperature fluctuations. For example, the explosion-proof and thermally insulating barrier articles can be incorporated into primary structures extending along or around the compartmentalized structure of transport or buildings to protect users and occupants. Such applications may include protection around battery modules, fuel tanks, and other enclosures or compartments.

[0079] Further components, their configurations, and test methods are described in the following subsections.

[0080] Furthermore, the particle size of the inorganic filler particles in the binder layer can be limited only by the thickness of the ceramic layer. Typically, the inorganic filler particles have a maximum particle size of about 8000 μm in at least one direction. More typically, the inorganic filler particles have a particle size ranging from about 0.1 μm to about 2000 μm in at least one direction. Even more typically, the inorganic filler particles have a particle size ranging from about 0.2 μm to about 50 μm in at least one direction.

[0081] These layers, and consecutive layers, are shown to be in flat contact with each other in Figures 1A-1D. However, it should be understood that the layers of barrier articles 1A-1D are flexible, and the contact areas between layers may not be planar or consecutive.

[0082] The barrier articles 1a to 1d in Figures 1A to 1D may be positioned in one or more locations within an electric vehicle battery module. Typically, multiple battery cells are structurally aligned and fixed within a battery housing. The battery cells can be of any shape (e.g., cylindrical or rectangular) or size. Generally, there are gaps between each battery cell and / or between the battery cells and the wall of the battery housing. The barrier articles may be fixed to the lid of the housing or positioned on the wall of the battery housing.

[0083] Experiments and Examples Table 1: Test materials [Table 1]

[0084] In this embodiment, seven types of ceramic compositions were used. Ceramic composition A: 63.5% Kasil 6 + 0.8% deionized water + 35.7% Polyplate P01 Ceramic composition B: 59.5% Kasil 6 + 2.0% deionized water + 38.5% Polyplate P01 Ceramic composition C: 52.0% Kasil 1 + 31.0% Satintone SP33 + 17.0% Suzorite 20S Ceramic composition D: 48.0% Kasil 1 + 12.0% Sodium K Silicate + 40.0% Polyplate P01 Ceramic composition E: 60.0% Kasil 6 + 20.0% CFP 012 + 20.0% Fused Silica 550 Ceramic composition F: 78.8% sodium potassium silicate + 0.2% Nextel 720 chopped fiber + 11.0% Mattex Pro + 10.0% Suzorite 20S Ceramic composition G: 61.0% Kasil 6 + 4.0% Nycon RC + 35.0% Mattex Pro

[0085] Table 2: Weight percentage of each component in the ceramic composition after drying [Table 2]

[0086] Bending adjustment A 100 x 100 mm fiber / ceramic sample was placed halfway on the edge of a laboratory bench, with a plate positioned parallel to the sample on top, leaving half of the sample unconstrained in space. The free half of the sample was bent downward at an angle of approximately 45 degrees in the center, causing a crack in the dry ceramic, but the fibers did not break. The sample was clearly damaged along this central crack.

[0087] bend adjustment A 100 x 100 mm fiber / ceramic sample was bent around a 6-inch diameter cylinder as follows: 1) A pair of opposite sides of a 100 x 100 mm square sample were placed parallel to the axis of the cylinder, and the sample was bent in one direction around the cylinder (bent out of the plane) so that the sample had a smooth and tight curvature around the cylinder. 2) Next, the sample was placed on the opposite side of the cylinder so that it could be bent in the opposite direction. 3) Steps 1) and 2) were repeated 9 times, resulting in a total of 10 bends in each direction. This simulates the process of a dried material passing around multiple rolls in a manufacturing line, or the possible handling during the manufacturing process. After the initial bend, bending becomes easier, which indicates partial breakage or loosening of the ceramic material and / or loosening from the ceramic fibers.

[0088] Pyrotechnic impact test A pyrotechnic impact test (also called a pyrotechnic resistance test) involves mounting a cloth and / or ceramic sample on an aluminum plate fixed 30 mm above a pyrotechnic gelbug, and igniting the gelbug to generate an explosion. The pyrotechnic charge in a general-purpose gelbug composition contains potassium nitrate, potassium benzoate, sulfur, and titanium. These components are mixed and then filled into a complexly wound paper tube using a hydraulic press. A clay nozzle is pressed into the tube against the pyrotechnic charge. The gelbug can be ignited in various ways, but is usually ignited by an electronically generated pulse for precise timing. The ignited charge produces an explosion of combustion particles and hot gases, which are ejected through the nozzle.

[0089] The pyrotechnic test was video recorded at 30 frames per second. Before the 20-second duration of the pyrotechnic gelb ended, the explosion from the gelb damaged the cloth / ceramic structure, and then the aluminum plate. The pyrotechnic test recording was analyzed with video editing software to determine the time when the gelb explosion first started and the time when the gelb explosion was observed to have penetrated the aluminum plate. The total time the specimen with the aluminum plate withstood the explosion was calculated by subtracting the time when the explosion was observed to have penetrated the aluminum plate from the time when the explosion first started. This difference was rounded to the nearest 0.1 second. The time required to penetrate the aluminum plate without ceramic or cloth was 0.80 seconds, with a standard deviation of 0.08 seconds (n=4). All results shown below are calculated by subtracting the 0.8 seconds required to penetrate the aluminum plate from the total time required for the specimen with the aluminum plate to penetrate the explosion. For example, if a sample with an aluminum plate withstands an explosion for 9.8 seconds until the aluminum plate penetrates the back of the sample, the pyrostatic resistance time of that sample is 9.8 - 0.8 = 9.0 seconds. To calculate the efficiency or relative performance (pyrostatic resistance efficiency) of structures of different thicknesses, this pyrostatic resistance time can be divided by the thickness of the tested structure. This pyrostatic resistance efficiency result is expressed in seconds / millimeter, and a higher value indicates a material that withstands explosions more effectively or efficiently.

[0090] Examples Comparative example 1 (CE1) Kasil 6 was applied to a layer of TG430 using a #30 Meyer bar, and immediately afterward, another layer of TG430 was placed on top of the Kasil 6 layer. This structure was dried in an oven at 120°C. The structure was very flexible and could be wrapped around a 6-inch diameter cylinder with relatively little force. Two 100×100mm specimens were cut from this structure and attached to a 100×100mm aluminum plate using 91022 transfer adhesive, and pyrotechnic tests were performed. One specimen withstood 2.8 seconds before being destroyed by the explosion, and the other specimen withstood 1.2 seconds.

[0091] Comparative Example 2 (CE2) Kasil 6 was applied to a layer of TG430 using a #30 Meyer bar, and immediately afterward, another layer of TG430 was placed on top of the Kasil 6 layer. This was repeated two more times to create a four-layer TG430 structure bonded with three thin layers of Kasil 6. This structure was dried in an oven at 120°C. The structure was very flexible and could be wrapped around a 6-inch diameter cylinder with relatively little force. Two 100×100mm samples were cut from this structure and attached to a 100×100mm aluminum plate using 91022 transfer adhesive, and pyrotechnic tests were performed. One sample withstood 3.5 seconds before being destroyed by the explosion, and the other sample withstood 4.3 seconds.

[0092] Comparative Example 3 (CE3) Kasil 6 was applied to a layer of SC2025 using a #30 Meyer bar, and immediately afterward, another layer of SC2025 was placed on top of the Kasil 6 layer. This structure was dried in an oven at 120°C. The structure was very flexible and could be wrapped around a 6-inch diameter cylinder with relatively little force. Two 100×100mm specimens were cut from this structure and attached to a 100×100mm aluminum plate using 91022 transfer adhesive, and pyrotechnic tests were performed. Both specimens withstood 1.8 seconds before being destroyed by explosion.

[0093] Comparative Example 4 (CE4) Ceramic composition B was applied to two 100 × 100 mm aluminum plates and dried first at 100°C, then at 120°C. After drying at 100°C, the brittle coating cracked into five individual irregularly shaped pieces, which were warped and not flat. After drying at 120°C, this brittle coating cracked into even more pieces, each consisting of approximately 7-8 pieces, and was further warped. The thickness of this dried coating was 0.79 mm. To subject this composition to pyrotechnic testing, 91022 adhesive was applied to two new 100 × 100 mm aluminum plates, and the individual pieces were carefully placed on the adhesive. A flat plate was then placed on top, and the pieces were pressed down to ensure that the slightly warped pieces adhered to the adhesive. Further fracture occurred in the coating during this process, but the pieces adhered well to the adhesive, and there were sufficiently large areas without fracture, allowing the pyrotechnic gel to be placed in the fracture-free area. One sample withstood 7.8 seconds before being destroyed by the explosion, and the other sample withstood 4.5 seconds. While this ceramic structure offers good resistance in pyrotechnic testing, its brittleness makes it difficult to process in a continuous manner, nor can it be handled in large quantities without breaking.

[0094] Comparative Example 5 (CE5) Ceramic composition B was applied onto a layer of SC2025 and dried at 120°C. Two 100 x 100 mm samples were cut from this coating and subjected to bending. During bending, the samples developed cracks in numerous places, and pieces of ceramic peeled off from the SC2025 fibers in numerous places. Although this two-layer structure yielded a more planar structure than Comparative Example 4, it was more difficult to process in a roll-to-roll manufacturing process, and it was not easy to handle it continuously without compromising its properties.

[0095] Comparative example 6 (CE6) Three 100 x 100 mm squares were cut from 0.75 mm thick 304 stainless steel and each was subjected to a pyrotechnic test. Only the steel plates were subjected to the pyrotechnic test (no aluminum plates or adhesives were used). One sample withstood the test for 2.5 seconds, while the other two samples each withstood for 1.3 seconds.

[0096] Comparative example 7 (CE7) Three 100 x 100 mm squares were cut from 1.61 mm thick 304 stainless steel and each was subjected to a pyrotechnic test. Only the steel plates were subjected to the pyrotechnic test (no aluminum plates or adhesives were used). One sample withstood the test for 5.5 seconds, while the other two samples each withstood for 5.3 seconds.

[0097] Comparative example 8 (CE8) Three 100 x 100 mm squares were cut from 2.24 mm thick 304 stainless steel and each was subjected to a pyrotechnic test. Only the steel plates were subjected to the pyrotechnic test (no aluminum plates, no adhesive). One sample withstood for 11.6 seconds, another for 8.9 seconds, and the third for 9.0 seconds.

[0098] Table 3: Pyrotechnic test results for Comparative Examples 1-4 [Table 3] *The pyrotechnic resistance time is the time the entire structure with the aluminum plate withstood the explosion, minus the time the aluminum plate itself withstood the explosion (0.8 seconds). Pyrotechnic resistance efficiency is the pyrotechnic resistance time divided by the thickness of the structure.

[0099] Example 1 Ceramic composition A was applied between the SC2025 layer and the 1162 cross layer and dried in an oven at 120°C. This resulted in a thickness of 1.53 mm and a base weight of 2520 g / m². 2 A structure was obtained. Two 100 x 100 mm samples were cut from this structure and attached to a 100 x 100 mm aluminum plate using 91022 transfer adhesive (with the SC2025 side facing the adhesive side), and then subjected to a pyrotechnic test. One sample withstood the explosion for 9.8 seconds before being destroyed, and the other sample withstood for 11.1 seconds.

[0100] Example 2 Ceramic composition A was applied between the SC2025 layer and the 1162 cross layer and dried in an oven at 120°C. This resulted in a thickness of 1.49 mm and a base weight of 2470 g / m². 2A structure was obtained. One 100 x 100 mm sample was cut from this structure and attached to a 100 x 100 mm aluminum plate using 91022 transfer adhesive (with the 1162 side facing the adhesive side), and then subjected to a pyrotechnic test. This sample withstood the explosion for 9.4 seconds before being destroyed.

[0101] Example 3 Ceramic composition A was applied between the SC2025 layer and the 1162 cross layer and dried in an oven at 120°C. This resulted in a thickness of 1.50 mm and a base weight of 2470 g / m². 2 A structure was obtained. One 100 x 100 mm sample was cut from this structure and used for bending adjustment. This cracked structure was attached to a 100 x 100 mm aluminum plate using 91022 transfer adhesive (with the 1162 side facing the adhesive side), and a pyrotechnic test was performed so that the gelb exploded towards the center of the crack in the structure. This sample withstood 10.6 seconds before being destroyed by the explosion.

[0102] Example 4 Ceramic composition B was applied between two layers of TG430 cloth and dried in an oven at 120°C. This resulted in a thickness of 1.28 mm and a base weight of 2300 g / m². 2 A structure was obtained. Two 100 x 100 mm samples were cut from this structure and attached to a 100 x 100 mm aluminum plate using 91022 transfer adhesive, and then subjected to a pyrotechnic test. One sample withstood the explosion for 10.5 seconds before being destroyed, and the other sample withstood for 8.5 seconds.

[0103] Example 5 Ceramic composition B was applied between two layers of TG430 cloth and dried in an oven at 120°C. This resulted in a thickness of 1.28 mm and a base weight of 2300 g / m². 2 A structure was obtained. Two 100 x 100 mm samples were cut from this structure and each was used for bending adjustment. These bent samples were attached to a 100 x 100 mm aluminum plate using 91022 transfer adhesive and subjected to pyrotechnic testing. One sample withstood for 9.9 seconds, and the other for 9.7 seconds.

[0104] Example 6 Ceramic composition A was applied between the SC2025 layer and the 1162 cross layer and dried in an oven at 120°C. As a result, a structure with a thickness of 1.22 mm and a basis weight of 1890 g / m 2 was obtained. Two 100×100 mm samples were cut out from this structure, attached to a 100×100 mm aluminum plate using the 91022 transfer adhesive (with the 1162 side facing the adhesive side), and directly subjected to the pyrotechnic test. These samples withstood for an average of 7.1 seconds until they were destroyed by the explosion.

[0105] Example 7 Ceramic composition A was applied between the SC2025 layer and the 1162 cross layer and dried in an oven at 120°C. As a result, a structure with a thickness of 1.72 mm and a basis weight of 2890 g / m 2 was obtained. Two 100×100 mm samples were cut out from this structure, attached to a 100×100 mm aluminum plate using the 91022 transfer adhesive (with the 1162 side facing the adhesive side), and directly subjected to the pyrotechnic test. These samples withstood for an average of 14.6 seconds until they were destroyed by the explosion.

[0106] Example 8 Ceramic composition A was applied between the 1162 cross layer and the 1597 cross layer and dried in an oven at 120°C. As a result, a structure with a thickness of 1.84 mm and a basis weight of 3010 g / m 2 was obtained. Two 100×100 mm samples were cut out from this structure, attached to a 100×100 mm aluminum plate using the 91022 transfer adhesive (with the 1162 side facing the adhesive side), and directly subjected to the pyrotechnic test. One sample withstood for 14.9 seconds and the other sample withstood for 13.9 seconds.

[0107] Example 9 Ceramic composition A was applied between two layers of 1162 cross and dried in an oven at 120°C. As a result, a structure with a thickness of 0.59 mm and a basis weight of 1030 g / m 2A structure was obtained. Two 100 x 100 mm samples were cut from this structure and attached to a 100 x 100 mm aluminum plate using 91022 transfer adhesive, and then subjected to a pyrotechnic test. One sample withstood for 2.7 seconds, and the other sample withstood for 2.9 seconds.

[0108] Example 10 Ceramic composition C was applied between the PW-200-13-100 layer and the PW-350-13-100 layer and dried in an oven at 120°C. This resulted in a thickness of 1.49 mm and a base weight of 1820 g / m². 2 A structure was obtained. Two 100 x 100 mm samples were cut from this structure and attached to a 100 x 100 mm aluminum plate using 91022 transfer adhesive (with the PW-200-13-100 side facing the adhesive side), and then subjected to a pyrotechnic test. One sample withstood for 10.4 seconds, and the other sample withstood for 7.7 seconds.

[0109] Example 11 Ceramic composition D was applied between two layers of TG430 cloth and dried in an oven at 120°C. This resulted in a thickness of 1.03 mm and a base weight of 1650 g / m². 2 A structure was obtained. Two 100 x 100 mm samples were cut from this structure and attached to a 100 x 100 mm aluminum plate using 91022 transfer adhesive, and then subjected to a pyrotechnic test. One sample withstood for 7.7 seconds, and the other sample withstood for 9.1 seconds.

[0110] Example 12 Ceramic composition D was applied between two layers of TG430 cloth and dried in an oven at 120°C. This resulted in a thickness of 1.02 mm and a base weight of 1650 g / m². 2 A structure was obtained. Two 100 x 100 mm samples were cut from this structure and used for bending adjustment. These cracked structures were attached to a 100 x 100 mm aluminum plate using 91022 transfer adhesive, and a pyrotechnic test was performed so that a gelb would explode towards the center of the crack in the structure. One sample withstood for 8.2 seconds, and the other sample withstood for 7.3 seconds.

[0111] Example 13 Ceramic composition E was applied between the SC2025 layer and the TG430 cloth layer and dried in an oven at 120°C. This resulted in a thickness of 1.56 mm and a base weight of 2210 g / m². 2 A structure was obtained. Two 100 x 100 mm samples were cut from this structure and attached to a 100 x 100 mm aluminum plate using 91022 transfer adhesive (with the SC2025 side facing the adhesive side), and then subjected to a pyrotechnic test. One sample withstood for 4.8 seconds, and the other sample withstood for 4.7 seconds.

[0112] Example 14 Ceramic composition E was applied between the SC2025 layer and the TG430 cloth layer and dried in an oven at 120°C. This resulted in a thickness of 1.56 mm and a base weight of 2240 g / m². 2 A structure was obtained. Two 100 x 100 mm samples were cut from this structure and used for bending adjustment. These cracked structures were attached to a 100 x 100 mm aluminum plate using 91022 transfer adhesive (with the SC2025 side facing the adhesive side), and a pyrotechnic test was performed so that the gelb would explode towards the center of the structure. One sample withstood for 4.6 seconds, and the other sample withstood for 4.5 seconds.

[0113] Example 15 Ceramic composition F was applied between two layers of TG430 cloth and dried in an oven at 120°C. This resulted in a thickness of 1.19 mm and a base weight of 1860 g / m². 2 A structure was obtained. Two 100 x 100 mm samples were cut from this structure and attached to a 100 x 100 mm aluminum plate using 91022 transfer adhesive, and then subjected to a pyrotechnic test. One sample withstood for 5.0 seconds, and the other sample withstood for 6.1 seconds.

[0114] Example 16 Ceramic composition F was applied between two layers of TG430 cloth and dried in an oven at 120°C. This resulted in a thickness of 1.10 mm and a base weight of 1750 g / m². 2A structure was obtained. Two 100 x 100 mm samples were cut from this structure and used for bending adjustment. These cracked structures were attached to a 100 x 100 mm aluminum plate using 91022 transfer adhesive, and a pyrotechnic test was performed so that the gelb exploded towards the center of the structure. One sample withstood for 5.0 seconds, and the other sample withstood for 5.1 seconds.

[0115] Example 17 Ceramic composition G was applied between two layers of TG430 cloth and dried in an oven at 120°C. This resulted in a thickness of 1.24 mm and a base weight of 1730 g / m². 2 A structure was obtained. Two 100 x 100 mm samples were cut from this structure and attached to a 100 x 100 mm aluminum plate using 91022 transfer adhesive, and then subjected to a pyrotechnic test. One sample withstood for 3.7 seconds, and the other sample withstood for 4.5 seconds.

[0116] Example 18 Ceramic composition G was applied between two layers of TG430 cloth and dried in an oven at 120°C. This resulted in a thickness of 1.27 mm and a base weight of 1710 g / m². 2 A structure was obtained. Two 100 x 100 mm samples were cut from this structure and subjected to bending adjustment. These cracked structures were attached to a 100 x 100 mm aluminum plate using 91022 transfer adhesive, and a pyrotechnic test was performed so that a gelb would explode towards the center of the crack in the structure. One sample withstood for 4.3 seconds, and the other sample withstood for 4.0 seconds.

[0117] Table 4: Pyrotechnical test results for Examples 1-18 [Table 4]

[0118] Example 1 illustrates the variability in this test, showing moderate variation between samples (note that there was also variability in the simpler comparative example). Example 2, using undamaged ceramic, survived for 9.4 seconds. Example 3, using ceramic with a crack in the center of the explosion, survived for 10.6 seconds. Example 3, using ceramic with a crack sandwiched between fabric layers, showed better performance than the undamaged Example 2, but given the variability in this test, Example 3 is likely to perform similarly to Example 2. This demonstrates the synergistic effect of sandwiching the ceramic layer between the fabric layers.

[0119] Furthermore, the structure with ceramic sandwiched between layers of fabric showed improved pyrostatic resistance compared to the stainless steel comparative example. For example, the pyrostatic resistance efficiency of the sandwich structures in Examples 1-3 was approximately twice that of the 304 stainless steel comparative sample of similar thickness (Comparative Example 7).

[0120] Since the overall structural weight is extremely important for the performance of electric vehicles, the pyrotechnic resistance of these structures was evaluated based on weight rather than thickness. The density of 304 stainless steel (base weight divided by thickness) is approximately 7.9 g / cm³. 3 In contrast, the density of Examples 1-3 is approximately 1.7 g / cm³. 3 The pyrotechnic resistance values ​​(based on time) of the structures in Examples 1-3 are approximately twice that of the 304 stainless steel example. Therefore, as a function of weight (assuming the same thickness for the ceramic / cloth structure and the stainless steel example), the ceramic / cloth structures described herein have approximately nine times better pyrotechnic resistance than the stainless steel comparative example. In other words, for a given pyrotechnic explosion resistance, a stainless steel heat barrier article is approximately nine times heavier than a ceramic / cloth heat barrier article of comparable thickness (described herein).

[0121] Two samples from Example 4, which were not subjected to bending or flexing, survived for an average of 9.5 seconds. Two samples from Example 5, which had the same composition but underwent flexing adjustment, survived for an average of 9.8 seconds, demonstrating the synergistic effect of placing the ceramic layer between the fabric layers. This structure enhances both ease of manufacture and ease of use.

[0122] Furthermore, despite these examples containing two layers with relatively low pyrotechnic efficiency and one layer with relatively high pyrotechnic efficiency, the overall pyrotechnic efficiency of the structure is close to that of a single ceramic (which has high pyrotechnic efficiency). Comparative Example 4, which is ceramic alone, has a pyrotechnic efficiency of 7.8, while Examples 4 and 5 have 7.4 and 7.6, respectively, which are nearly comparable to Comparative Example 4. This is achieved despite the actual amount of ceramic being small, as indicated by both the overall thickness and base weight of Examples 4 and 5. The thickness of the ceramic in Examples 4 and 5 can be estimated by subtracting the thickness of the two TG430 layers from the overall structure thickness: 1.28 - 2 × (0.38) = 0.52 mm. The overall thickness of Comparative Example 4 (0.79 mm) is greater than that of Examples 4 and 5. There is also a phenomenon of ceramic seeping into the TG430. To account for this seepage, subtract the base weight of the TG430 fabric from the total base weight of Examples 4 and 5: 2300 - 2 × 430 = 1440 g / m 2 This is the 1690 g / m² of Comparative Example 4. 2 It is less than that. Therefore, laminated inorganic fabric / ceramic / inorganic fabric structures have a synergistic effect in terms of explosive performance.

[0123] Examples 7 and 8 demonstrate thicker, heavier structures designed to withstand extremely high-energy battery explosions. Even thicker structures may be employed depending on the specific application.

[0124] Example 9 demonstrates that a very thin ceramic layer (approximately 0.31 mm) can be formed between layers of glass cloth. This structure can be easily bent and flexed while still providing explosion resistance and can be easily manufactured in a continuous manufacturing process. A ceramic material only 0.31 mm thick would not withstand the tensile forces required to pass through a manufacturing process, even if it were lightly flexed on a large roll with a diameter of 25 cm (or more). Different battery systems and pack structures require different types of explosion protection. Depending on the different sizes and forms of batteries with higher energy density, and depending on the different pack structures (e.g., different backing plates or differences in the distance between the battery vent port and the explosive material), different thicknesses may be required to optimize weight, thickness, explosion protection, etc. Therefore, the ability to process structures with thinner ceramics is useful in battery applications that require lower explosion performance compared to others.

[0125] Example 10 shows the use of a blend of different types of fillers, the use of an inorganic fabric made of basalt fibers, and a ceramic composition consisting of 24 wt% binder and 76 wt% filler (on a dry basis).

[0126] Examples 11 and 12 show ceramic compositions containing two different binders, namely a blend of sodium silicate and potassium silicate. Similar to Examples 2 and 3, Examples 11 and 12 further demonstrate that even if the ceramic interlayer of the inorganic cloth / ceramic / inorganic cloth structure is bent and cracked, it can withstand pyrotechnic testing with little effect on explosive performance.

[0127] Examples 13 and 14 demonstrate the use of ceramic compositions blended with two different fillers. The flaked boron nitride filler exhibits anisotropic high thermal conductivity and very high thermal conductivity in the planar direction. Planar-oriented boron nitride flakes can provide heat dissipation in the planar direction of the ceramic because they preferentially orient in the plane during the coating process, especially with high flake concentrations.

[0128] By comparing the explosion resistance of Examples 13 and 14, it is demonstrated that the inorganic fabric / ceramic / inorganic fabric structure can be bent without losing explosion resistance.

[0129] Examples 15 and 16 show ceramic compositions having a high concentration of binder and three different fillers. After drying, the binder concentration is 61.3% by weight of sodium silicate and 0.4% by weight of inorganic fibers.

[0130] By comparing the explosion resistance of Examples 15 and 16, it is demonstrated that the inorganic fabric / ceramic / inorganic fabric structure can be bent without significantly impairing its explosion resistance.

[0131] Examples 17 and 18 show ceramic compositions with relatively high fiber concentrations. The fiber concentration in the dried ceramic is 6.4% by weight. By comparing the explosion resistance of Examples 17 and 18, it is shown that the inorganic fabric / ceramic / inorganic fabric structure can be bent without significantly impairing its explosion resistance and can still withstand cracking.

[0132] To address the data variability between samples subjected to direct pyrotechnic testing and those that underwent bending or flexing adjustments, samples were compared within each composition group. For example, the average pyrotechnic resistance (4.125 seconds) of the four structures in Examples 17 and 18 was subtracted from the individual values ​​for each structure in Examples 17 and 18. This resulted in deviations from the mean of the two structures in Example 17 (directly tested) of -0.43 seconds and +0.38 seconds, and deviations from the mean of the two structures in Example 18 (bending adjusted) of +0.18 seconds and -0.13 seconds. These deviations from the mean are shown in Table 5 for all pairs of directly tested and bent or flexing adjusted structures.

[0133] Table 5 shows the time difference from the mean value within each composition for pairs of samples tested as is and samples that were bent or flexed. The mean value for each composition group in Table 5 is zero (within the range of the rounding error of the significant figures shown).

[0134] Table 5 [Table 5]

[0135] Comparing the datasets of all 11 unbent, uncurved structures with the datasets of all 11 bent or curved structures, both datasets are shown to be statistically equivalent. Surprisingly, the largest deviations from the mean (both positive and negative) were found in the unbent, uncurved structures, at -1.15 seconds and +1.03 seconds, respectively. The mean for the 11 unbent, uncurved structures was +0.04 seconds with a standard deviation of 0.68 seconds. The mean for the 11 bent or curved structures was -0.04 seconds with a standard deviation of 0.35 seconds. The mean for the 11 bent or curved structures is slightly smaller than the mean for the 11 unbent, uncurved structures, but the standard deviations of both datasets are more than an order of magnitude larger than these means. This strongly suggests that the mean of the unbent, uncurved dataset is essentially the same as the mean of the bent or curved structures. A two-sample t-test comparing these two datasets shows that they are statistically identical: the p-value for this two-sample t-test is 0.76. A p-value greater than approximately 0.05 between two datasets suggests that the datasets have the same mean or mean value. Since 0.76 is much greater than 0.05, we can confidently say that the bending and flexing data are statistically identical to the unbent, unflexed structures; that is, bending and flexing do not alter their explosion resistance.

[0136] Furthermore, plotting these two datasets on a normal distribution probability plot (Figure 3) shows that each dataset follows a normal distribution: the p-value for the 11 unbent, straight structures is 0.76, and the p-value for the 11 bent or bent structures is 0.64. Since these p-values ​​are much larger than 0.05, these datasets follow a normal distribution, confirming that it is reasonable to compare the two datasets using a two-sample t-test.

[0137] All composition groups (e.g., Examples 2 and 3, 4 and 5, or 11 and 12) that were tested as is, or bent or curved, were made with different ceramic compositions, different thicknesses, and different inorganic fabric layers. To compensate for these differences, each composition group can be normalized to a percentage change from the mean and the same analysis can be performed. For example, the percentage changes from the mean for Examples 17 and 18 are -10.3% and +9.1% for the two Example 17 structures, and +4.2% and -3.0% for the two Example 18 structures (Table 6). The p-value for this two-sample t-test is 0.52 (much greater than 0.05), indicating that both datasets are statistically identical. Plotting the two datasets on a probability plot shows that both follow a normal distribution: the p-value for 11 unbent, uncurved structures is 0.50, and the p-value for 11 bent or curved structures is 0.96. This confirms that the results of the two-sample t-test show no statistically significant difference between the unbent, uncurved structures and the bent or curved structures.

[0138] Table 6 shows the percentage difference from the mean value within each composition for pairs of samples tested as is and samples that were bent or flexed. The mean value for each composition group is zero (within the range of the rounding error of the significant figures shown).

[0139] Table 6 [Table 6]

[0140] These embodiments demonstrate that placing ceramic or ceramic-like materials between layers of glass cloth provides a user-friendly structure with unexpected synergistic properties, suitable for manufacturing. These structures can be processed in continuous manufacturing processes and can be bent or flexed without adversely affecting explosive properties. A wide range of inorganic cloth structures can be utilized for these structures. The binder may be a single composition or a mixture of two or more binders. The filler may be a single inorganic material or a mixture of different materials. The shape of the filler may be spherical, plate-like, fibrous, and / or amorphous. The thickness of the fibrous cloth and ceramic may vary widely depending on the specific application.

[0141] All documents, patents, and patent applications cited in the above patent application are hereby incorporated in their entirety by reference and applied in a consistent manner. In the event of any inconsistency or contradiction between the incorporated portions of the cited documents and this application, the information set forth above shall prevail. The above description is provided to enable a person skilled in the art to implement the requested disclosure and should not be construed as limiting the scope of the disclosure as defined by the claims and their equivalents.

Claims

1. A thermal barrier article comprising a multilayer material, wherein the multilayer material comprises a first fiber layer, a second fiber layer, and at least one ceramic layer, the at least one ceramic layer comprising a first ceramic layer comprising an inorganic filler and an inorganic binder, the first fiber layer being located on a first side of the first ceramic layer, the second fiber layer being located on the opposite side of the first ceramic layer, the thermal barrier article having sufficient flexibility to withstand a bending adjustment test as defined herein, and capable of withstanding a pyrotechnic impact test as defined herein, having a temperature of at least 1200°C and releasing a non-negligible amount of particles, for at least 2.5 seconds.

2. The heat barrier article according to claim 1, wherein the heat barrier article has sufficient flexibility to withstand the bending adjustment test defined herein and can withstand the pyrotechnic shock test for at least 6 seconds.

3. The thermal barrier article according to claim 1, wherein the at least one fiber layer comprises a plurality of fiber layers, the at least one ceramic layer comprises a plurality of ceramic layers, and the multilayer material comprises an alternating arrangement of the plurality of fiber layers and the plurality of ceramic layers.

4. The heat barrier article according to any one of claims 1 to 3, wherein the at least one fiber layer includes a woven or nonwoven fiber mat or fiber cloth.

5. The heat barrier article according to claim 4, wherein the fiber layer includes inorganic fibers.

6. The thermal barrier article according to any one of claims 1 to 5, wherein the form of the inorganic filler is selected from the group consisting of beads, solid particles, pulverized powder, flakes, needles, rods, chopped fibers, hollow spheres, hollow tubes, and combinations thereof.

7. The thermal barrier article according to claim 1, wherein the inorganic filler comprises a filler material selected from the group consisting of kaolin clay, metakaolin, talc, mica, mullite, phlogopite, muscovite, montmorillonite, smectite, bentonite, illite, chlorite, sepiolite, attapulgite, halloysite, vermiculite, laponite, rectolite, perlite, fly ash, fumed silica, silica fume, Portland cement, concrete mixtures, and combinations thereof.

8. The thermal barrier article according to claim 1 or 6, wherein the inorganic binder comprises an inorganic binder selected from the group consisting of sodium silicate, potassium silicate, lithium silicate, calcium silicate, colloidal silica, (poly)phosphate, (poly)borate, (poly)aluminate, water, and combinations thereof.

9. The thermal barrier article according to any one of claims 1, 7, and 8, wherein the at least one ceramic layer comprises about 0.2% to about 3.0% by weight of cut organic fibers selected from the group consisting of PVA fibers, polypropylene fibers, fibers formed from polyolefin blends or copolymers, nylon fibers, and blends thereof.

10. The thermal barrier article according to any one of claims 1 to 9, wherein the fiber layer of the multilayer material is identical throughout the multilayer material in at least one of the composition and thickness.

11. The thermal barrier article according to any one of claims 1 to 10, wherein the fiber layers of the multilayer material may contain different materials in some or all of the multiple fiber layers and / or have different thicknesses.

12. The thermal barrier article according to any one of claims 1 to 11, wherein the ceramic layer of the multilayer material is identical throughout the multilayer material in at least one of its composition and thickness.

13. The thermal barrier article according to any one of claims 1 to 12, wherein the ceramic layers of the multilayer material may contain different materials in some or all of the multiple ceramic layers and / or have different thicknesses.

14. The heat barrier article according to any one of claims 1 to 13, wherein the at least one fiber layer comprises a fiber mat or fiber cloth of a woven or nonwoven fabric containing a plurality of fibers selected from the group consisting of A glass, C glass, D glass, E glass, M glass, R glass, S glass, ECR glass, AR glass, basalt fiber, silicate fiber, silicon carbide fiber, and ceramic fiber.

15. The thermal barrier article according to any one of claims 1 to 14, wherein the at least one fiber layer comprises a ceramic or mineral composition selected from the group consisting of basalt, alumina, aluminoborosilicate, Nextel, silicon carbide, quartz, and combinations thereof.

16. The thermal barrier article according to any one of claims 1 to 3, wherein at least one of the first fiber layer and the second fiber layer includes a coating having an alkali-resistant composition.

17. The thermal barrier article according to claim 16, wherein the alkali-resistant composition comprises calcium silicate.

18. The thermal barrier article according to claim 1, comprising an adhesive layer on the outer surface of at least one of the first fiber layer or the second fiber layer.

19. The thermal barrier article according to claim 18, wherein the adhesive layer includes an adhesive selected from the group consisting of thermosetting adhesives, hot melt adhesives, pressure-sensitive adhesives, solvent-based adhesives, and water-based adhesives.

20. The heat barrier article according to any one of claims 1 to 19, wherein the heat barrier article has a thickness in the range of about 0.5 mm to about 5.0 mm.

21. The heat barrier article according to any one of claims 1 to 20, wherein each fiber layer has a thickness in the range of about 0.04 mm to about 1.5 mm.

22. The thermal barrier article according to any one of claims 1 to 21, wherein each ceramic layer has a thickness in the range of about 0.2 mm to about 1.5 mm.

23. A battery compartment for an electric vehicle, comprising at least one battery cell or battery assembly, wherein a heat barrier article according to any one of claims 1 to 22 is disposed between the at least one battery cell or battery assembly and a lid.

24. A method for preventing or at least mitigating the further diffusion of explosive fragments within or from an electric vehicle battery assembly, the method comprising at least partially surrounding at least one battery cell or battery module of the electric vehicle battery assembly with a thermal barrier article according to any one of claims 1 to 22.

25. Use of a barrier article as a thermal insulation and explosion protection barrier in a rechargeable electrical energy storage system, wherein the barrier article comprises the composition of a thermal barrier article according to any one of claims 1 to 22.

26. The thermal barrier article according to any one of claims 1 to 22, wherein at least one of the first fiber layer and the second fiber layer includes a multilayer structure in which the layers are mechanically bonded.

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