Article with thermal insulation properties

Abstract

The present disclosure relates generally to the field of cushioning articles, and more particularly to the field of articles with pressure management and thermal insulation properties. In some embodiments, the article is a compressible thermally insulating foam for buffering between cells, the compressible thermally insulating foam including a silicone foam having a thermally insulating filler. The present disclosure also relates to methods of making such articles and their use in industrial applications for pressure and thermal management applications.

Description

Technical Field

[0001] This disclosure relates generally to the field of cushioning articles, and more specifically to the field of articles having pressure management and thermal insulation properties. In some embodiments, the article is a compressible insulating foam for cushioning between batteries, the compressible insulating foam comprising a silicone foam with insulating filler. This disclosure also relates to methods of manufacturing such articles and their use in industrial applications for pressure and thermal management applications. Background Technology

[0002] Currently, vehicle electrification is one of the biggest trends in the automotive industry. Within this trend, the industry is primarily focused on the propulsion of electric vehicles powered by battery-powered electrical energy and the development of suitable electric vehicle batteries as energy storage devices. Electric vehicle batteries are used to power the propulsion systems of battery electric vehicles (BEVs) and hybrid electric vehicles (HEVs). These batteries (typically lithium-ion batteries) are designed with high ampere-hour capacities. The trend in electric vehicle battery development is shifting towards higher energy densities (kWh / kg) in batteries to allow for longer driving ranges and reduced charging times.

[0003] Due to the high energy density of electric vehicle batteries and the high energy flow during charging or discharging, there is a risk of hot spots and thermal runaway events. In such cases, the heat generated by the decomposition of battery cells spreads very rapidly to neighboring cells. This chain reaction could lead to an explosion or fire of the entire electric vehicle.

[0004] Furthermore, during the normal lifespan of these energy storage devices, particularly during the fast charge and discharge cycles of electric vehicle batteries, the battery cells used in such battery modules tend to continuously expand and contract. These expansion / contraction cycles can subject the battery cells to considerable stress conditions, which can lead not only to mechanical damage to the battery cells but also to complete failure of the battery module.

[0005] Against this backdrop, the use of thermal management solutions has rapidly become a way to mitigate temperature rise in battery components. Summary of the Invention

[0006] In a general implementation, this disclosure relates to a multi-layered thermal barrier, which includes:

[0007] One or more insulating porous foam layers,

[0008] One or more heat-resistant layers are disposed on an insulating porous foam layer.

[0009] The thermal insulation porous foam layer alternates with the heat-resistant layer.

[0010] The heat-resistant layer contains insulating particles.

[0011] The multi-layered thermal barrier exhibits a pressure of at least 30 kPa when subjected to 20% compression.

[0012] The multi-layered thermal barrier exhibited a pressure of less than 2,500 kPa when subjected to 55% compression, and

[0013] The cold plate requires more than 500 seconds to reach 150°C in the HCST test.

[0014] In some implementations, the weight ratio of the insulating porous foam layer to the heat-resistant layer in a multi-layer thermal barrier is 20%-75%.

[0015] In other embodiments, the multilayer thermal barrier does not have the following three-layer structure:

[0016] First heat-resistant layer,

[0017] A thermally insulating porous foam layer, which is adjacent to the first heat-resistant layer, and

[0018] The second heat-resistant layer is adjacent to the heat-insulating porous foam layer.

[0019] In other embodiments, the multilayer thermal barrier has the following three-layer structure:

[0020] First heat-resistant layer,

[0021] A thermally insulating porous foam layer, which is adjacent to the first heat-resistant layer, and

[0022] The second heat-resistant layer is adjacent to the heat-insulating porous foam layer. Attached Figure Description

[0023] Figure 1 —A multilayer thermal barrier (100) comprising an insulating porous foam layer (101) and one or more heat-resistant layers (102). Optionally, it is encapsulated with an organic polymer layer (106).

[0024] Figure 2 —Battery module 200 includes components of battery cells 202. One or more multilayer thermal barriers 201 formed of the exemplary materials described herein may be disposed at one or more locations throughout the battery module between individual battery cells or groups of battery cells.

[0025] Figure 3—The battery pack 300 includes a plurality of battery modules 302. A series of multi-layer thermal barriers 301 formed of the exemplary material described herein are configured to be placed between adjacent battery modules or on top of battery modules 302. The black rectangles indicate the placement of multi-layer thermal barriers on top of battery modules. Alternatively, the multi-layer thermal barriers may be placed between one or more battery packs and the walls of a battery pack container (not shown).

[0026] Figure 4 —The manufacturing process of the heat-resistant layer (102) of the multi-layer thermal barrier (100).

[0027] Figure 5 —The manufacturing process of the insulating porous foam layer (101) for assembling a multi-layer thermal barrier (100).

[0028] Figure 6 —A graph showing the compression response of a sample containing vermiculite.

[0029] Figure 7 —A graph showing the compression response of a sample containing ATH.

[0030] Figure 8 —This shows a graph illustrating the compression response of samples containing different fillers.

[0031] Figure 9 —This shows a graph illustrating the compression response of samples containing different fillers.

[0032] Figure 10 —This shows a graph illustrating the compression response of samples containing different fillers.

[0033] Figure 11 —A graph showing the thermal conductivity of samples containing different fillers.

[0034] Figure 12A —This shows a graph illustrating the response of samples containing different fillers in the HCST test.

[0035] Figure 12B —This shows a graph illustrating the response of samples containing different fillers in the HCST test.

[0036] Figure 13A — A photomicrograph of a worm sample before it expands.

[0037] Figure 13B — A photomicrograph of a worm sample after it has expanded.

[0038] Figure 14A — A photomicrograph of a worm sample before it expands.

[0039] Figure 14B — A photomicrograph of a worm sample after it has expanded.

[0040] Figure 15A — A photomicrograph of a worm sample before it expands.

[0041] Figure 15B — A photomicrograph of a worm sample after it has expanded.

[0042] Figure 16A —This shows a graph illustrating the compression response of different samples.

[0043] Figure 16B —This shows a graph illustrating the response of different samples in the HCST test.

[0044] Figure 17A —This shows a graph illustrating the compression response of different samples.

[0045] Figure 17B —This shows a graph illustrating the response of different samples in the HCST test.

[0046] Figure 18 —This shows a graph illustrating the response of different samples in the HCST test. Detailed Implementation

[0047] According to the first aspect, this disclosure relates to a multi-layered thermal barrier, the multi-layered thermal barrier comprising:

[0048] One or more insulating porous foam layers,

[0049] One or more heat-resistant layers, wherein the one or more heat-resistant layers are disposed on the heat-insulating porous foam layer.

[0050] The thermal insulation porous foam layer alternates with the heat-resistant layer.

[0051] The heat-resistant layer contains insulating particles.

[0052] The multi-layered thermal barrier exhibits a pressure of at least 30 kPa when subjected to 20% compression.

[0053] The multilayer thermal barrier exhibits a pressure of less than 2,500 kPa when subjected to 55% compression, and

[0054] The cold plate requires more than 500 seconds to reach 150°C in the HCST2 test.

[0055] In the context of this disclosure, it has been surprisingly found that the multilayer thermal barrier described above possesses excellent thermal insulation properties, excellent thermal runaway barrier performance, and excellent compressibility and pressure management characteristics. In some advantageous respects, the multilayer construction described above further exhibits excellent heat resistance and stability even at temperatures up to 600°C and after prolonged exposure to heat.

[0056] The multilayer structure is further characterized by one or more of the following advantages: a) excellent cushioning performance for individual battery cells when used in battery modules; b) excellent tolerance to high compressive and high-pressure conditions throughout the life of the battery module; c) the ability to maintain the foam structure of the polymer foam layer even under high-pressure conditions; d) a simple and cost-effective manufacturing method based on the availability of raw materials and the minimization of manufacturing steps; e) simple and versatile construction; f) excellent formulation flexibility of the polymer foam layer used herein; g) excellent construction and design of spacers in various ways. h) Flexibility in form, size, and shape; i) The ability to fine-tune the compression characteristics of multilayer structures for specific applications, operating conditions, and cell types; j) Excellent pressure distribution for individual cell units when used in battery assemblies; k) Excellent processability and conversion characteristics; l) Low thermal conductivity; m) The ability to be fabricated with relatively low thickness; n) Ready-to-use articles, particularly for thermal management applications; n) Extended durability of energy storage components using the cushioning articles of this disclosure; and o) The ability to adhere to various substrates such as metal or polymer surfaces without requiring adhesion-assisted processing steps or compositions.

[0057] These findings were particularly unexpected for various reasons. First, good cushioning properties and tolerance to high compressive forces and high pressure conditions are considered contradictory characteristics. Furthermore, thermal insulation and heat resistance are generally not desirable with compressible (soft) porous foam layers, especially those with relatively low thicknesses, and even more so under compression.

[0058] In the context of this disclosure, the inventors faced the technical challenge of designing a multilayer thermal barrier structure that achieved a delicate balance of excellent compressibility, tolerance to high compressive forces, and thermal insulation properties.

[0059] Not wanting to be bound by theory, it is believed that these superior characteristics and performance properties are particularly due to, for example, Figure 1 The combination of the following technical features emphasized herein: a) the use of an insulating porous foam layer (101) having specific properties; and b) the use of one or more heat-resistant layers (102) having specific properties disposed on the insulating porous foam layer. Optionally encapsulated by an encapsulating material (106). These layers may be arranged in other constructional arrangements, such as, for example, the porous foam layer (101) disposed on the heat-resistant layer (102). The components may also be further stacked on top of each other.

[0060] Not wishing to be bound by theory, it is believed that one or more heat-resistant layers as described above advantageously serve as a reaction force device to prevent or at least reduce unwanted compressive forces borne by the insulating porous foam layer, not only during normal charge and discharge cycles of the electric vehicle battery, but also during more extreme conditions such as thermal runaway events. More specifically, it is believed that one or more heat-resistant layers as described above can maintain critical and minimal gaps between battery cells even under high-pressure conditions, while still ensuring the appropriate buffering characteristics necessary to allow the battery cells to expand and contract during their life cycle. This ability to maintain these characteristics is considered to directly and advantageously influence the excellent thermal insulation properties provided by the buffer articles of this disclosure.

[0061] Considering that one or more of the aforementioned heat-resistant layers are expected to adversely affect the foam structure of the insulating porous foam layer, thereby impairing the thermal barrier properties, the set of advantageous properties detailed above provided by the multilayer construction described herein is even more surprising.

[0062] Therefore, multilayer thermal barriers are suitable for a variety of industrial applications, particularly thermal management applications. The multilayer thermal barriers disclosed herein are particularly suitable for thermal management applications in the transportation industry (especially the automotive industry), especially as thermal barriers, and even more so as thermal runaway barriers. Multilayer thermal barriers as described herein are ideally suited for use as separators with thermal runaway barrier characteristics in rechargeable energy storage systems, particularly battery modules. Advantageously, the multilayer thermal barriers of this disclosure can be used in the manufacture of battery modules, particularly electric vehicle battery modules and components. In one advantageous aspect, multilayer thermal barriers as described herein are suitable for manual or automated handling and application (especially by rapid robotic equipment), particularly due to their excellent robustness, dimensional stability, and handling characteristics. In some advantageous aspects, the multilayer thermal barriers also meet challenging fire safety standards due to their outstanding flame retardancy and thermal stability characteristics.

[0063] On one advantage, the multilayer thermal barrier used herein provides thermal insulation when subjected to hot-side / cold-side testing (further defined in the Examples section). Reaching a temperature of 150°C on the cold side requires more than 500 seconds.

[0064] On one advantage, when measured according to the compression test method described in the experimental section, the multilayer thermal barrier used herein achieves a compression value of at least 60% when using compressive forces not greater than 1000 kPa, 900 kPa, 800 kPa, 700 kPa, 600 kPa, 500 kPa, 400 kPa, 300 kPa, 250 kPa, 200 kPa, 150 kPa, 100 kPa, 80 kPa, 60 kPa, or even 50 kPa.

[0065] In another advantageous aspect, when measured according to the compression test method described in the experimental section, the multilayer thermal barrier used in this paper achieves a compression value of at least 20% when using a compressive force greater than 30 kPa, greater than 40 kPa, greater than 50 kPa, or even greater than 60 kPa.

[0066] In the context of this disclosure, the term "adjacent" is intended to mean two stacked films or layers that are arranged directly adjacent to each other (i.e., abutting or in direct contact with each other), or that are not arranged directly adjacent to each other (i.e., when at least one additional film or layer (e.g., an adhesive layer) is arranged between the initial two stacked films or layers). In the context of this disclosure, the term "closely adjacent" is intended to mean two stacked films or layers that are arranged directly adjacent to each other (i.e., abutting or in direct contact with each other). The terms top layer and bottom layer, or top film and bottom film, are used herein to indicate the position of a layer or film relative to the surface of the substrate supporting such a layer or film during the formation of a polymer foam layer. The direction of movement of a movable substrate, layer, or film is referred to herein as the downstream direction. The related terms upstream and downstream describe the position along the extension of the substrate.

[0067] Thermally Insulating Porous Foam Layer

[0068] The insulating porous foam layers used in this article are not particularly limited, but some insulating porous foam layers can provide various advantages over others.

[0069] According to an advantageous aspect, the porous foam layer used herein comprises a material that, when measured according to the thermal stability test method described in the experimental section, has a weight loss of no more than 70%, no more than 60%, no more than 50%, no more than 40%, no more than 30%, or even no more than 25% after three minutes at 600°C.

[0070] The porous foam layer type described above is usually referred to as heat-resistant material or heat-resistant foam layer.

[0071] According to one exemplary aspect, the porous foam layer used in the multilayer construction of this disclosure comprises a material selected from the group consisting of: elastomeric materials, thermoplastic materials, thermoplastic elastomer materials, thermoplastic non-elastomeric materials, thermosetting materials, and any combination or mixture thereof.

[0072] In one advantageous aspect, the porous foam layer used herein comprises materials selected from the group consisting of: silicone elastomers, fluorinated silicone rubbers, aromatic polyamides, polybenzimidazoles, polysulfides, polyimides, polysulfones, polyetherketones, fluorocarbons, polyisoprene, polybutadiene, polychloroprene, polyurethanes, polyolefins (particularly polyethylene, polypropylene, and ethyl vinyl acetate), polystyrene, and any combination or mixture thereof.

[0073] On a more advantageous side, the porous foam layer used in this paper comprises materials selected from the group consisting of elastomeric materials.

[0074] In another advantageous aspect, when measured according to the compression test method described in the experimental section, the polymer foam layer used herein achieves a compression value of at least 60% when using compressive forces not exceeding 1000 kPa, 900 kPa, 800 kPa, 700 kPa, 600 kPa, 500 kPa, 400 kPa, 300 kPa, 250 kPa, 200 kPa, 150 kPa, 100 kPa, 80 kPa, 60 kPa, or even 50 kPa. This type of polymer foam layer is commonly referred to as a (relatively highly) compressible polymer foam layer (or flexible polymer foam layer).

[0075] In another more advantageous aspect, the porous foam layer used herein comprises materials selected from the group consisting of: silicone elastomers, particularly silicone rubber, and more particularly organopolysiloxane polymers.

[0076] In a particularly advantageous aspect of this disclosure, the porous foam layer used herein is a silicone rubber foam layer.

[0077] According to an advantageous aspect, the silicone rubber foam layer used herein can be obtained from a curable and foamable precursor of the silicone rubber foam layer, particularly a precursor composition that can be foamed in situ.

[0078] The precursor compositions for silicone rubber foams used herein are not particularly limited, as long as they are curable and foamable. Any curable and foamable precursors for silicone rubber foams commonly known in the art may be formally used in the context of this disclosure. Those skilled in the art will readily identify suitable curable and foamable precursors for silicone rubber foams used herein, based on this disclosure.

[0079] According to a more favorable aspect, the precursor for the silicone rubber foam layer used herein is a two-part composition.

[0080] In one typical aspect, the bipartite precursor composition of silicone rubber foam is selected from the group consisting of addition-curing bipartite silicone compositions, condensation-curing bipartite silicone compositions, and any combination or mixture thereof.

[0081] In a preferred aspect, the precursor of the silicone rubber foam used herein comprises an addition-curing bipartite organosilicon composition, particularly an addition-curing bipartite organopolysiloxane composition.

[0082] Those skilled in the art can readily identify suitable addition-curing bipartite organopolysiloxane compositions used herein as precursors for silicone rubber foams based on the following disclosure.

[0083] According to a particularly advantageous aspect of this disclosure, the precursor for the silicone rubber foam used herein comprises:

[0084] a) At least one organopolysiloxane compound A;

[0085] b) At least one organohydrogen polysiloxane compound B containing at least two, in particular at least three, hydrogen atoms per molecule;

[0086] c) At least one hydroxyl-containing compound C;

[0087] d) An effective amount of curing catalyst D, especially a platinum-based curing catalyst; and

[0088] e) Optional foaming agent.

[0089] In one exemplary aspect, at least one organopolysiloxane compound A used herein has the following formula:

[0090]

[0091] in:

[0092] R and R” are independently chosen from C1 to C2. 30 The group consisting of hydrocarbon groups, and in particular, R is an alkyl group selected from the group consisting of methyl, ethyl, propyl, trifluoropropyl and phenyl, and optionally, R is a methyl group;

[0093] R' is C1 to C 20 The alkenyl group, and in particular, R' is selected from the group consisting of vinyl, allyl, hexenyl, decenyl and tetradecenyl, and more particularly, R' is a vinyl group;

[0094] R” is in particular an alkyl group, such as methyl, ethyl, propyl, trifluoropropyl, phenyl, and especially, R” is a methyl group; and

[0095] n is an integer with values ​​in the range of 5 to 1000, particularly 5 to 100.

[0096] In another exemplary aspect, the at least one hydroxyl-containing compound C used herein is selected from alcohols; polyols, particularly polyols having 3 to 12 carbon atoms and having at least two hydroxyl groups per molecule on average; silanols; organopolysiloxanes containing silanols; silanes containing silanols; water; and any combination or mixture thereof.

[0097] In yet another exemplary aspect, at least one hydroxyl-containing compound C used herein is selected from the group consisting of organopolysiloxanes containing silanols.

[0098] According to an advantageous aspect of this disclosure, the porous foam layer used herein can be obtained by a method comprising the following steps:

[0099] a) Provide a base;

[0100] b) Provide a first solid film and apply the first solid film onto the substrate;

[0101] c) Provide a coating tool having an upstream side and a downstream side, wherein the coating tool is offset from the substrate to form a gap perpendicular to the surface of the substrate;

[0102] d) Move the first solid film relative to the coating tool in the downstream direction;

[0103] e) Provide the curable (and foamable) precursor of the porous foam to the upstream side of the coating tool, thereby coating the porous foam precursor as a layer onto the substrate provided with the first solid film through the gap.

[0104] f) Provide a second solid film and apply the second solid film (at least partially) along the upstream side of the coating tool, such that the first solid film and the second solid film are applied simultaneously with the (adjacent) layers of the silicone rubber foam precursor;

[0105] g) Foaming or allowing the precursor of the porous foam to foam;

[0106] h) Curing or allowing the layer of the porous foam precursor to cure, thereby forming a porous foam layer;

[0107] i) Optionally, expose a layer of the porous foam precursor to heat treatment; and

[0108] Optionally, the first solid membrane and / or the second solid membrane are removed from the porous foam layer.

[0109] Figure 5The diagram illustrates an exemplary method for manufacturing a polymer foam layer (particularly a silicone rubber foam layer) and a schematic diagram of a coating apparatus suitable for this manufacturing method. The coating apparatus 1 includes a substrate 2, a coating tool 7 in the form of a coating blade, an unwinding roller 11 and a winding roller 12 for a first solid film 5, and an unwinding roller 9 and a winding roller 10 for a second solid film 6. (The substrate 2 is provided with the first solid film 5.) The downstream direction 8 of the movement of the first solid film relative to the coating tool 7 is indicated by an arrow with the corresponding reference numerals.

[0110] In one typical aspect of this disclosure, a curable and foamable precursor 3 of porous foam is provided upstream of the coating tool 7, thereby coating the porous foam precursor 3 as a layer onto a substrate 2 provided with a first solid film 5 through gaps. Figure 5 In this design, a curable and foamable precursor 3 of porous foam is represented as forming a so-called "rolling bead" at the upstream side of a coating tool 7. A second solid film 6 is applied (at least partially) along the upstream side of the coating tool 7, such that a first solid film 5 and a second solid film 6 are applied simultaneously with the formation of a layer of the porous foam precursor 3. The layer of the porous foam precursor 3 is then allowed to foam and cure, thereby producing a porous foam layer 4, which typically has a first solid film 5 on its bottom surface and a second solid film 6 on its top surface. Optionally, the layer of the porous foam precursor 3 may be exposed to heat treatment typically performed in an oven (not shown). In a typical aspect, the thickness of the porous foam layer 4 resulting from the foaming of the porous foam precursor 3 layer is greater than the initial layer of the porous foam precursor 3. After processing, the first solid film 5 and / or the second solid film 6 may be removed from the porous foam layer 4.

[0111] According to an advantageous aspect, the porous foam precursor used in this article is a composition that can be foamed in situ, which means that the foaming of the precursor occurs without the need for any additional compounds, especially external compounds.

[0112] According to another advantageous aspect, the foaming of the porous foam precursor used in this paper is carried out using gaseous compounds, particularly hydrogen.

[0113] On a more advantageous side, the foaming of the porous foam precursor used in this paper is carried out by either gas generation or gas injection.

[0114] According to a preferred aspect, the foaming of the porous foam precursor used herein is carried out by gas generation, particularly in-situ gas generation.

[0115] In another aspect, the porous foam precursor used in this article also includes an optional foaming agent.

[0116] The substrate used herein is not particularly limited. Those skilled in the art can readily identify suitable substrates for use herein based on this disclosure.

[0117] In a typical aspect of this disclosure, the substrate used herein is a temporary support for manufacturing purposes and for the separation and removal of the silicone rubber foam layer therefrom after foaming and curing. The substrate may optionally be provided with a surface treatment agent adapted to allow clean removal of the silicone rubber foam layer from the substrate (through a first solid film). Advantageously, the substrate used herein and providing the temporary support may be provided in the form of an annular strip. Alternatively, the substrate used herein may be a static temporary support.

[0118] In one particular aspect of this disclosure, the porous foam layer obtained after foaming and curing is separated from the substrate and can be wound into, for example, rolls.

[0119] According to an advantageous aspect of this disclosure, the substrate used herein comprises a material selected from the group consisting of polymers, metals, ceramics, composite materials, and any combination or mixture thereof.

[0120] The porous foam layer used in this disclosure can be obtained by using a coating tool provided with an upstream side and a downstream side. The coating tool is offset from the substrate to form a gap perpendicular to the surface of the substrate.

[0121] The coating tools used herein are not particularly limited. Any coating tool commonly known in the art may be used in the context of this disclosure. Those skilled in the art can readily identify suitable coating tools for use herein based on this disclosure.

[0122] The coating tools used in this disclosure each have an upstream side (or surface) and a downstream side (or surface). In a typical aspect, the coating tool used herein also has a bottom portion facing the surface of the substrate that receives the precursor of the polymer foam. The gap is measured as the minimum distance between the bottom portion of the coating tool and the exposed surface of the substrate. The gap may be substantially uniform in the transverse direction (i.e., in the direction perpendicular to the downstream direction), or it may vary continuously or discontinuously in the transverse direction. The gap between the coating tool and the surface of the substrate is typically adjusted to control the thickness of the corresponding coating and other parameters, including, for example, the speed of the substrate in the downstream direction, the type of coating tool, the angle at which the coating tool is oriented relative to the normal of the substrate, and the type of substrate.

[0123] In one advantageous aspect of this disclosure, the gap between the coating tool and the substrate (coating tool gap) is in the range of 10 micrometers to 3000 micrometers, 50 micrometers to 2500 micrometers, 50 micrometers to 2000 micrometers, 50 micrometers to 1500 micrometers, 100 micrometers to 1500 micrometers, 100 micrometers to 1000 micrometers, 200 micrometers to 1000 micrometers, 200 micrometers to 800 micrometers, or even 200 micrometers to 600 micrometers.

[0124] The coating tool used herein may be arranged perpendicular to the surface of the substrate, or may be tilted such that the angle between the substrate surface and the downstream side (or surface) of the coating tool is in the range of 50° to 130° or even 80° to 100°. The coating tool used herein is generally solid and may be rigid or flexible. The coating tool used herein may take on various shapes, forms, and sizes depending on the target application and desired properties of the silicone rubber foam layer.

[0125] In one advantageous aspect, the coating tools used herein comprise materials selected from the group consisting of polymers, metals, ceramics, composites, glass, and any combination or mixture thereof. More advantageously, the coating tools used herein comprise materials selected from the group consisting of metals, particularly aluminum, stainless steel, and any combination thereof. Flexible coating tools used herein are generally relatively thin and have a thickness ranging from 0.1 mm to 0.75 mm, particularly in the downstream direction. Rigid coating tools used herein are generally at least 1 mm thick or even at least 3 mm thick.

[0126] According to a typical aspect of this disclosure, the coating tool used herein is selected from the group consisting of coating knives, coating blades, coating rollers, coating roller blades, and any combination thereof.

[0127] On one hand, the coating tool used in this paper is selected from coating knives. Indeed, it has been found that using coating tools in the form of coating knives provides a more reproducible coating method and a better quality coating, which translates into a silicone rubber foam layer with advantageous properties.

[0128] In another advantageous aspect, the coating tool used in this paper is selected from the group consisting of a coating roller and an air knife.

[0129] According to another advantageous aspect, the cross-sectional shape of the bottom portion of the coating tool (especially a coating knife) in the longitudinal direction is designed to allow the formation of a precursor layer and the removal of excess precursor. Typically, the cross-sectional shape of the bottom portion of the coating tool, as it extends laterally towards the substrate, is substantially planar, curved, concave, or convex.

[0130] According to an advantageous aspect of this disclosure, the porous foam layer of this disclosure can be obtained by a method wherein the step of providing a curable (and foamable) precursor of porous foam to the upstream side of a coating tool is immediately followed by providing a second solid film and applying the second solid film along the upstream side of the coating tool, such that the steps of applying the first solid film and the second solid film are performed simultaneously with the formation of the (adjacent) layer of the porous foam precursor.

[0131] According to another advantageous aspect of this disclosure, the steps of foaming or allowing the porous foam precursor to foam and curing or allowing the layer of the porous foam precursor to cure to form a porous foam layer are performed simultaneously.

[0132] The solid membranes used herein as the first and second solid membranes are not particularly limited. Any solid membrane commonly known in the art may be formally used in the context of this disclosure. Suitable solid membranes for use herein can be readily identified by those skilled in the art based on this disclosure.

[0133] According to an advantageous aspect, the first solid membrane and / or the second solid membrane used in this disclosure are impermeable membranes, particularly impermeable flexible membranes. As used herein, the term "impermeable" is intended to mean impermeable to liquid and gaseous compounds, particularly gaseous compounds.

[0134] According to another advantageous aspect of this disclosure, the first solid membrane and / or the second solid membrane used herein are selected from the group consisting of polymer membranes, metal membranes, composite membranes, and any combination thereof.

[0135] In a more advantageous aspect of this disclosure, the first and / or second solid films used herein are selected from the group consisting of polymer films, particularly comprising polymer materials selected from the group consisting of thermoplastic polymers.

[0136] In another more advantageous aspect of this disclosure, the first solid membrane and / or the second solid membrane used herein are polymer membranes, wherein the polymer material is selected from the group consisting of polyester, polyether, polyolefin, polyamide, polybenzimidazole, polycarbonate, polyethersulfone, polyoxymethylene, polyetherimide, polystyrene, polyvinyl chloride, and any mixture or combination thereof.

[0137] In another more advantageous aspect of this disclosure, the first solid membrane and / or the second solid membrane used herein are polymer membranes comprising a polymer material selected from the group consisting of polyesters, polyolefins (particularly PP and PE), polyetherimides, and any mixtures or combinations thereof.

[0138] In a particularly advantageous aspect, the first solid membrane and / or the second solid membrane used in this disclosure are polymer membranes comprising a polymer material selected from the group consisting of polyesters, particularly polyethylene terephthalate.

[0139] According to an advantageous aspect of this disclosure, the porous foam layer of this disclosure can be obtained by a method in which a first solid film is applied to the bottom surface of the layer of the porous foam precursor, and a second solid film is applied to the top (exposed) surface of the layer of the porous foam precursor.

[0140] In one typical aspect of this disclosure, the first solid membrane and / or the second solid membrane are in direct contact with the adjacent porous foam layer.

[0141] In another advantageous aspect of this disclosure, the first primary (top) surface and the second (opposite) primary (bottom) surface of the porous foam layer and / or the first solid film and / or the second solid film are free from any adhesion-promoting composition or treatment agent, particularly free from primer composition, adhesive composition and physical surface treatment agent.

[0142] In another advantageous aspect of this disclosure, the first primary (top) surface and the second (opposite) primary (bottom) surface of the porous foam layer and / or the first solid film and / or the second solid film contain an adhesion-promoting composition or treatment agent, particularly a primer composition, an adhesive composition, and a physical surface treatment agent.

[0143] In another advantageous aspect of this disclosure, no intermediate layer of any kind is contained between the first primary (top) surface or the second (opposite) primary (bottom) surface of the porous foam layer and the first solid film and / or the second solid film.

[0144] In one typical aspect of this disclosure, the first and second solid films are in close contact with the corresponding surfaces of the silicone rubber foam layer, thereby avoiding (or at least reducing) the inclusion of air between the solid films and the corresponding surfaces of the porous foam layer.

[0145] According to an advantageous aspect, the porous foam layer used herein includes gas cavities, particularly hydrogen gas cavities, air gas cavities, and any mixtures thereof.

[0146] According to an advantageous aspect, the porous foam layer used herein includes air cavities with a rectangular shape in the direction of the layer thickness (i.e., in the direction perpendicular to the plane formed by the foam layer).

[0147] According to a more favorable aspect, the air cavities that can exist in the silicone rubber foam layer have an elongated elliptical shape in the direction of the layer thickness.

[0148] Furthermore, the air cavity used in this paper is not surrounded by any ceramic or polymer shell (other than the surrounding silicone polymer matrix).

[0149] In one particular aspect, the mean size (at its largest scale) of the air cavities used in this paper is no greater than 500 μm, no greater than 400 μm, no greater than 300 μm, no greater than 200 μm, no greater than 150 μm, no greater than 120 μm, no greater than 100 μm, no greater than 80 μm, no greater than 60 μm, no greater than 50 μm, no greater than 40 μm, no greater than 30 μm, or even greater than 20 μm (when calculated from SEM micrographs).

[0150] In another specific aspect, the mean average size (at the largest scale) of the air cavities used in this paper is in the range of 5 μm to 3000 μm, 5 μm to 2000 μm, 10 μm to 1500 μm, 20 μm to 1500 μm, 20 μm to 1000 μm, 20 μm to 800 μm, 20 μm to 600 μm, 20 μm to 500 μm, or even 20 μm to 400 μm (when calculated from SEM micrographs).

[0151] According to one typical aspect, the porous foam layer used herein does not contain a hollow cavity (surrounded by any ceramic or polymer shell) selected from the group consisting of hollow microspheres, glass bubbles, expandable microspheres, especially hydrocarbon-filled expandable microspheres, hollow inorganic particles, expanded inorganic particles, and any combination or mixture thereof.

[0152] According to an advantage, the porous foam layer used in this paper comprises non-synthetic foam.

[0153] The porous foam layer used in this article may contain additional (optional) components or additives, depending on the target application.

[0154] In one particular aspect of this disclosure, the porous foam layer used herein also comprises additives, which are particularly selected from the group consisting of: flame retardants, softeners, hardeners, filler materials, tackifiers, nucleating agents, colorants, pigments, preservatives, rheology modifiers (particularly aluminum hydroxide, magnesium hydroxide, magnesium carbonate, calcium magnesium carbonate, hydromagnesia, calcium magnesium carbonate-hydromagnesia, hydromagnesia and calcium carbonate), UV stabilizers, thixotropic agents, surface additives, flow additives, nanoparticles, antioxidants, reinforcing agents, toughening agents, silica particles, glass or synthetic fibers, insulating particles, conductive particles, electrically insulating particles, infrared shading particles, and any combination or mixture thereof.

[0155] On one advantageous aspect, the porous foam layer also comprises a non-flammable (or non-combustible) filler material. On an even more advantageous aspect, the non-flammable filler material used herein is selected from inorganic fibers, particularly from the group consisting of mineral fibers, mineral wool, silicate fibers, ceramic fibers, glass fibers, carbon fibers, graphite fibers, asbestos fibers, aramid fibers, and any combination or mixture thereof.

[0156] According to a more favorable aspect, the non-flammable filler material used herein is selected from the group consisting of mineral fibers, silicate fibers, ceramic fibers, asbestos fibers, aramid fibers, and any combination or mixture thereof.

[0157] According to a particularly advantageous aspect, the non-flammable filler materials used herein are selected from the group consisting of mineral fibers. In the context of this disclosure, it has been surprisingly found that polymer foams (particularly silicone rubber foams) also containing mineral fibers exhibit excellent heat resistance and thermal stability properties, as well as improved resistance to surface cracking and surface brittleness even after prolonged exposure to temperatures up to 600°C. Without wishing to be bound by theory, these beneficial properties are believed to be particularly attributable to the excellent compatibility of the mineral fibers (particularly silicate fibers) with the surrounding polymer matrix (particularly an organosilicon polymer matrix), which participates in densifying and mechanically stabilizing the resulting matrix.

[0158] In one particular aspect of this implementation, based on the total weight of the porous foam precursor composition, the non-flammable filler material used herein is included in the polymer foam in an amount ranging from 0.5% to 40% by weight, 1% to 30% by weight, 1% to 20% by weight, 1% to 10% by weight, 1% to 8% by weight, 2% to 8% by weight, 2% to 6% by weight, or even 3% to 6% by weight.

[0159] In another typical aspect, the porous foam layer used in this paper does not contain thermally conductive fillers.

[0160] In another aspect of this disclosure, the porous foam layer comprises inorganic particles. These inorganic particles can be solid, hollow, or include multiple pores. Such particles can include, for example, unexpanded expanded material particles, irreversibly or permanently expanded expanded materials, diatomaceous earth, inorganic aerogel materials, porous ceramic (e.g., silica) materials, irreversibly or permanently expanded perlite minerals, hollow ceramics, or other inorganic (e.g., glass) microspheres. Such porous inorganic particles, such as those found, for example, in irreversibly or permanently expanded vermiculite, are particularly desirable. Irreversible or permanently expanded perlite mineral particles also include pores, but perlite minerals are harder and less compressible than vermiculite minerals. Silica-based and other aerogel particles also include pores.

[0161] As used herein, irreversibly or permanently expanding expandable particles (e.g., vermiculite and perlite mineral particles) refer to particles that have been heated to a temperature and time such that the particles irreversibly or permanently expand to at least 10% and at most 100% of their expandability, or are pre-expanded before being used to form a thermal runaway barrier, or are post-expanded after being incorporated into a nonwoven fiber thermal insulation monolayer.

[0162] Expandable particles (e.g., vermiculite particles) can be permanently expanded by overheating the particles beyond their reversible point (e.g., in the range of about 350°C to about 1000°C for vermiculite). Such permanently expanded particles (e.g., vermiculite particles) can have an expanded accordion or worm-like structure that, compared to the same particles in their unexpanded state, more readily breaks into smaller particles due to its elongated geometry, lower density, and lower mechanical stability. As the heating temperature increases, the degree of permanent expansion of the particles increases (i.e., the particles can become larger and / or longer). It is also desirable to use vermiculite that has been permanently expanded through chemical treatment methods.

[0163] Because they are more prone to splitting in their expanded state, post-expansion of the expanded particles is expected after the unexpanded expanded particles have been incorporated into the nonwoven fiber thermal insulation. Even with mild processing to prevent them from splitting substantially, it is believed that incorporating pre-expanded expanded particles into the nonwoven fiber thermal insulation can still cause the expanded particles to become oriented in the planes of the insulation (i.e., the x-axis, y-axis, and / or between). For example, with pre-expanded vermiculite particles, elongated particles may become generally aligned with the fiber in the longitudinal or downstream direction (i.e., the y-axis) of the nonwoven fiber thermal insulation, rather than in the thickness direction (i.e., the z-axis).

[0164] Conversely, when post-expanded (i.e., after preparing nonwoven fiber thermal insulation with unexpanded expanded particles), the expanded expanded particles are not primarily oriented in the plane of the insulation. Compared to the same particles in their expanded state, unexpanded expanded particles typically have a more uniform structural geometry (i.e., an aspect ratio closer to 1). This more uniform structural geometry is believed to be less likely to be affected by fiber alignment during the formation of the nonwoven fiber thermal insulation. As a result, post-expanded expanded particles are more likely to be isotropically oriented within the nonwoven fiber thermal insulation. For example, with respect to post-expanded vermiculite particles, elongated particles may become aligned in the thickness direction (i.e., the z-axis), in the plane (i.e., the x-axis, y-axis, and / or between them), or in their off-axis directions. This difference in orientation between pre-expanded and post-expanded particles is believed to be caused by the more uniform structural geometry of the unexpanded particles compared to their expanded state.

[0165] According to an advantageous aspect of this disclosure, when measured according to the method described in the experimental section, the porous foam layer used herein has a strength of no more than 500 kg / m³. 3 Not greater than 450 kg / m 3 Not more than 400 kg / m 3 No more than 380 kg / m 3 No more than 350 kg / m 3 Not more than 320 kg / m 3 No more than 300 kg / m3 Not more than 280 kg / m 3 Not more than 250 kg / m 3 Not more than 220 kg / m 3 Or even no more than 200 kg / m 3 The density.

[0166] According to another advantageous aspect of this disclosure, when measured according to the method described in the experimental section, the porous foam layer used herein has a density of 200 kg / m³. 3 Up to 500kg / m 3 200kg / m 3 Up to 450kg / m 3 200kg / m 3 Up to 400kg / m 3 200kg / m 3 Up to 380kg / m 3 200kg / m 3 Up to 350kg / m 3 200kg / m 3 Up to 320kg / m 3 200kg / m 3 Up to 300kg / m 3 200kg / m 3 Up to 280kg / m 3 Or even 200kg / m 3 Up to 250kg / m 3 The density within the range.

[0167] According to another advantageous aspect of this disclosure, the porous foam layer used herein has a hardness greater than 10, greater than 15, greater than 20, greater than 25, greater than 30, greater than 40 or even greater than 50 (Shore 00).

[0168] According to another advantageous aspect of this disclosure, the porous foam layer used herein has a hardness (Shore 00) in the range of 10 to 80, 10 to 70, 20 to 70, 25 to 60, 25 to 55, 30 to 55, 30 to 50, 30 to 45 or even 30 to 40.

[0169] According to another advantageous aspect of this disclosure, when measured according to the thermal insulation test method 1 described in the experimental section, the porous foam layer used herein has a heat transfer time of up to 150°C of greater than 20 seconds, greater than 40 seconds, greater than 60 seconds, greater than 80 seconds, greater than 100 seconds, greater than 120 seconds, greater than 140 seconds, greater than 150 seconds, greater than 160 seconds, greater than 170 seconds, or even greater than 180 seconds.

[0170] According to another advantageous aspect of this disclosure, when measured according to the thermal insulation test method 1 described in the experimental section, the porous foam layer used herein has a heat transfer time of up to 150°C in the range of 20 to 200 seconds, 40 to 200 seconds, 60 to 200 seconds, 100 to 200 seconds, 120 to 200 seconds, 140 to 200 seconds, 160 to 200 seconds, or even 160 to 180 seconds.

[0171] According to another advantageous aspect of this disclosure, when measured according to the test methods described in the experimental section, the porous foam layer used herein has a thermal conductivity of not more than 1 W / m / K, not more than 0.8 W / m / K, not more than 0.6 W / m / K, not more than 0.5 W / m / K, not more than 0.4 W / m / K, not more than 0.3 W / m / K, not more than 0.2 W / m / K, not more than 0.1 W / m / K, not more than 0.05 W / m / K, or even not more than 0.01 W / m / K.

[0172] According to another advantageous aspect of this disclosure, when measured according to the test methods described in the experimental section, the porous foam layer used herein has a thermal conductivity in the range of 0.01 W / m / K to 1 W / m / K, 0.05 W / m / K to 1 W / m / K, 0.1 W / m / K to 1 W / m / K, 0.2 W / m / K to 1 W / m / K, or even 0.2 W / m / K to 0.8 W / m / K.

[0173] According to another advantageous aspect of this disclosure, the porous foam layer used herein undergoes a ceramization process at a temperature not exceeding 600°C, not exceeding 550°C, not exceeding 500°C, not exceeding 450°C, not exceeding 400°C, not exceeding 350°C, not exceeding 300°C, or even not exceeding 250°C.

[0174] According to another advantageous aspect of this disclosure, the porous foam layer used herein undergoes a ceramization process at temperatures ranging from 200°C to 600°C, 200°C to 550°C, 200°C to 500°C, 200°C to 450°C, 200°C to 400°C, 200°C to 350°C, 250°C to 350°C, or even 250°C to 300°C.

[0175] In the context of this disclosure, it has been surprisingly found that porous foam layers capable of undergoing ceramization, particularly at relatively low temperatures, possess excellent heat resistance and thermal stability properties.

[0176] According to another advantageous aspect of this disclosure, the porous foam layer used herein has a V-0 classification when measured according to the UL-94 standard flammability test method.

[0177] On one advantage, the porous foam layer used in this paper has a thickness of no more than 10,000 micrometers, no more than 8,000 micrometers, no more than 6,000 micrometers, no more than 5,000 micrometers, no more than 4,000 micrometers, no more than 3,000 micrometers, no more than 2,500 micrometers, no more than 2,000 micrometers, or even no more than 1,500 micrometers.

[0178] In another advantageous aspect, the porous foam layer used herein has a thickness ranging from 100 micrometers to 10,000 micrometers, 100 micrometers to 8,000 micrometers, 100 micrometers to 6,000 micrometers, 200 micrometers to 5,000 micrometers, 300 micrometers to 5,000 micrometers, 300 micrometers to 4,500 micrometers, 300 micrometers to 4,000 micrometers, 500 micrometers to 4,000 micrometers, 500 micrometers to 3,000 micrometers, 500 micrometers to 2,500 micrometers, 500 micrometers to 2,000 micrometers, 500 micrometers to 1,500 micrometers, 800 micrometers to 1,500 micrometers, or even 1,000 micrometers to 1,500 micrometers.

[0179] According to a particular aspect of this disclosure, the porous foam layer used herein may be provided with a first solid membrane and / or a second solid membrane. In an alternative embodiment, the polymer foam layer may not be provided with either the first solid membrane or the second solid membrane.

[0180] As will be apparent to those skilled in the art, the porous foam layers used herein can take on various forms, shapes, and sizes, depending on the target application. Similarly, the porous foam layers used herein can be post-processed or converted, as this is customary practice in the art.

[0181] According to one exemplary aspect, the porous foam layer used herein may be in the form of a roll, particularly a flat roll, around a core. The porous foam layer in the form of a roll may or may not have a first solid membrane and / or a second solid membrane.

[0182] According to one exemplary aspect, the porous foam layer used herein can be cut into smaller segments of various forms, shapes, and sizes.

[0183] Heat Resistant Layer

[0184] The multilayer thermal barrier disclosed herein also includes one or more heat-resistant layers disposed on or adjacent to the insulating porous foam layer.

[0185] One or more heat-resistant layers are dry-laid or wet-laid nonwoven fiber thermal insulation monolayers (e.g., in the form of pads, sheets, tapes, or three-dimensional thin-walled structures), comprising a fiber matrix of ceramic or other forms of nonmetallic (i.e., not metals, metal alloys, or metal composites) inorganic fibers, and thermally insulating ceramic or other forms of nonmetallic (i.e., not metals, metal alloys, or metal composites) inorganic particles (these inorganic particles are uniformly, consistently, substantially, or otherwise integrated throughout the manufacturing process or to a degree permissible by the manufacturing process (e.g., a small amount of particle settling may be present at the bottom of the pad in both dry-laid and wet-laid processes)). The inorganic filler particles and inorganic fibers are dispersed within the fiber matrix, and an organic or inorganic binder (e.g., organic or inorganic adhesive binder, organic or inorganic binder fibers that are needle-punched, sewn or otherwise mechanically wound into the fiber matrix to hold the fiber matrix together, etc.) is uniformly, consistently, substantially or otherwise dispersed throughout the manufacturing process or to the extent permitted by the manufacturing process in order to bond the inorganic filler particles and inorganic fibers together, or otherwise hold the fiber matrix together before being installed between battery cells, for the required time to withstand at least the required degree of handling (e.g. during the encapsulation process).

[0186] One or more heat-resistant layers may optionally be encapsulated by an organic material (e.g., polymer, paper, etc.) encapsulation layer (e.g., one or more opposing interlayers, each in the form of a film, coating, organic fiber nonwoven or woven fabric, etc.), the organic material encapsulation layer encapsulating all, most or part of at least one or two main surfaces, and preferably also encapsulating all, most or part of the outer periphery of the nonwoven fiber thermal insulation monolayer, to prevent or significantly reduce the shedding or loss of inorganic fibers or particles from the encapsulated nonwoven fiber thermal insulation monolayer.

[0187] The reduction in inorganic fiber or particle loss is significant when the amount of inorganic fiber or particle loss is less than 10%, 5%, or 1% of the original fiber or particle content of the nonwoven fiber thermal insulation layer. The thinner the organic encapsulation layer (i.e., the lower the organic content of the barrier), the better the thermal / cold test results.

[0188] The multi-layer thermal barrier of the present invention can be used between battery modules or components, or it can be positioned on top of or around the periphery of a battery module. Figure 2 and Figure 3A battery module (200, 300) including battery cells (202, 302) is shown. Multilayer thermal barriers (201, 301) are shown positioned between adjacent battery cells (202, 302) and on top of the battery cells (202, 302), respectively. The multilayer thermal barriers can be (a) provided in a stacked form within a container (e.g., cardboard or other box), (b) continuously adhered to the main surface of a strip of double-sided adhesive tape, the opposite main surface of which is protected by a release liner, or (c) sandwiched or otherwise arranged to encapsulate within a series of spaced-apart nonwoven fibrous thermal insulation layers between two relatively long organic (e.g., polymer) encapsulation layers (e.g., in the form of two films, coatings, fibrous fabrics, etc.).

[0189] Inorganic binders, organic binders, or combinations thereof used for heat-resistant layers may include, for example, those disclosed in US 8,834,759. Examples of inorganic binders suitable for dry-web or wet-web fiber processing may include silicone particles that transform into fusible silica upon heating. Organic-inorganic hybrid binders are also useful, such as, for example, WACKER. ® MQ803 TF is a co-hydrolysis product of tetraalkoxysilane (Q unit) and trimethylalkoxysilane (M unit). WACKER ® The chemical structure of MQ 803 TF can be viewed as a three-dimensional network of polysilicic acid units, which are capped with trimethylsilyl groups. Some residual ethoxy and hydroxyl functionalities exist. The average molecular weight can be precisely controlled by the ratio of M units to Q units. This ratio is relevant for WACKER... ® For the MQ 803 TF, it is approximately 0.67.

[0190] Exemplary binder fibers include bicomponent core-shell polymer fibers used in a dry web-forming process. In a wet web-forming process, ethylene vinyl acetate latex dispersion binders, bicomponent core-shell polymer fibers, or a combination of both can be used. When polymer binder fibers are used, the binder can be activated by heating and compressing the nonwoven fiber thermal insulation material. Combinations of organic and inorganic binders can also be used.

[0191] Exemplary commercially available heat-resistant layers that can be used in multilayer thermal barrier assemblies include the Flame Barrier FRB-NT series, FRB-BK series, FRB-WT series, and FRB-NC series (all purchased from 3M), flexible or rigid mica paper or sheets such as NEMA 86P purchased from Asheville Mica, NewsPort News, VA, United States, or flexible mica sheets from USA Mica, Tekonsha, MI, United States.

[0192] As used in this article, the term “inorganic” refers to ceramics or other non-metallic (i.e., not metals, metal alloys or metal composites) inorganic materials.

[0193] Thermal runaway is a phenomenon where a battery cell experiences an exothermic chain reaction, leading to an uncontrollable rise in the cell's temperature. Among other causes, exothermic chain reactions can be caused by factors such as overheating of the battery cell, overvoltage of the battery cell, and mechanical puncture of the battery cell.

[0194] "Thermal runaway" refers to the phenomenon where thermal runaway of a battery cell leads to thermal runaway of the remaining battery cells in a battery pack or system.

[0195] A "thermal runaway event" refers to a chain reaction in which one battery cell in a battery cell container overheats, causing adjacent battery cells to overheat and potentially leading to an explosion or fire, until the number of overheated battery cells reaches a critical point, resulting in the destruction of all or more of the battery cells in the module or its components. Factors that can cause battery cell overheating include: physical damage, application of overvoltage, and overheating (internal short circuit within the battery cell).

[0196] As the energy density of a battery cell increases, the temperature at which a battery cell begins to fail (e.g., from at least losing its efficiency or becoming inoperable to ignition, combustion, or explosion) decreases. Similarly, as the energy density of a battery cell decreases, the temperature at which a battery cell begins to fail increases. For example, with a controlled ramp-up of temperature, NMC811 battery cells tend to begin to fail or even explode when the temperature reaches approximately 120°C to 130°C, while NMC622 battery cells begin to fail or even explode when the temperature reaches approximately 180°C. For battery cells with lower energy densities (e.g., NMC532 and NMC433 battery cells), the corresponding temperatures are higher. For physically larger battery cells or when temperatures rise rapidly, thermal runaway through the battery cell can cause local temperatures to take longer to reach a critical point. It is believed that this thermal runaway effect can result in a slightly higher actual temperature at which a battery cell begins to fail or explode. The thermal runaway barrier of the present invention may be necessary to prevent adjacent cells from reaching temperatures in the range of approximately 130°C to approximately 150°C.

[0197] As used in this article, “preventing” thermal runaway events means preventing the overheating of a single battery cell from causing overheating of adjacent battery cells. This barrier is considered to prevent thermal runaway events when adjacent battery cells do not reach temperatures above 130°C to 150°C.

[0198] As used in this article, a “stop” thermal runaway event refers to an overheating of a single battery cell that causes only adjacent battery cells (i.e., one or two battery cells on either side of the overheated battery cell) to overheat, and the remaining battery cells in the battery module or assembly do not overheat.

[0199] As used herein, a “mitigated” thermal runaway event means that the thermal runaway event is mitigated for at least a sufficiently long time to allow persons adjacent to the battery module or component (e.g., occupants inside the passenger compartment of an electric vehicle) to escape to a safe distance away from the battery module or component before being injured by the thermal runaway event. Once a battery cell fails (e.g., catches fire) and a thermal barrier is present, the time for any adjacent battery cell to propagate the failure (e.g., fire) is at least five minutes, and preferably more than ten minutes or even twenty minutes.

[0200] Inorganic particles can be solid, hollow, or contain multiple pores. Such particles can include, for example, unexpanded expanded material particles, irreversibly or permanently expanded expanded materials, diatomaceous earth, inorganic aerogel materials, porous ceramic (e.g., silica) materials, irreversibly or permanently expanded perlite minerals, hollow ceramics, or other inorganic (e.g., glass) microspheres. Such porous inorganic particles, such as those found, for example, in irreversibly or permanently expanded vermiculite, are particularly desirable. Irreversible or permanently expanded perlite mineral particles also contain pores, but perlite minerals are harder and less compressible than vermiculite minerals. Silica-based and other aerogel particles also contain pores.

[0201] As used herein, irreversibly or permanently expanding expandable particles (e.g., vermiculite and perlite mineral particles) refer to particles that have been heated to a temperature and time such that the particles irreversibly or permanently expand to at least 10% and at most 100% of their expandability, or are pre-expanded before being used to form a thermal runaway barrier, or are post-expanded after being incorporated into a nonwoven fiber thermal insulation monolayer.

[0202] Expandable particles (e.g., vermiculite particles) can be permanently expanded by overheating the particles beyond their reversible point (e.g., in the range of about 350°C to about 1000°C for vermiculite). Such permanently expanded particles (e.g., vermiculite particles) can have an expanded accordion or worm-like structure that, compared to the same particles in their unexpanded state, more readily breaks into smaller particles due to its elongated geometry, lower density, and lower mechanical stability. As the heating temperature increases, the degree of permanent expansion of the particles increases (i.e., the particles can become larger and / or longer). It is also desirable to use vermiculite that has been permanently expanded through chemical treatment methods.

[0203] Because they are more prone to splitting in their expanded state, post-expansion of the expanded particles is expected after the unexpanded expanded particles have been incorporated into the nonwoven fiber thermal insulation. Even with mild processing to prevent them from splitting substantially, it is believed that incorporating pre-expanded expanded particles into the nonwoven fiber thermal insulation can still cause the expanded particles to become oriented in the planes of the insulation (i.e., the x-axis, y-axis, and / or between). For example, with pre-expanded vermiculite particles, elongated particles may become generally aligned with the fiber in the longitudinal or downstream direction (i.e., the y-axis) of the nonwoven fiber thermal insulation, rather than in the thickness direction (i.e., the z-axis).

[0204] Conversely, when post-expanded (i.e., after preparing nonwoven fiber thermal insulation with unexpanded expanded particles), the expanded expanded particles are not primarily oriented in the plane of the insulation. Compared to the same particles in their expanded state, unexpanded expanded particles typically have a more uniform structural geometry (i.e., an aspect ratio closer to 1). This more uniform structural geometry is believed to be less likely to be affected by fiber alignment during the formation of the nonwoven fiber thermal insulation. As a result, post-expanded expanded particles are more likely to be isotropically oriented within the nonwoven fiber thermal insulation. For example, with respect to post-expanded vermiculite particles, elongated particles may become aligned in the thickness direction (i.e., the z-axis), in the plane (i.e., the x-axis, y-axis, and / or between them), or in their off-axis directions. This difference in orientation between pre-expanded and post-expanded particles is believed to be caused by the more uniform structural geometry of the unexpanded particles compared to their expanded state.

[0205] The amount of inorganic fibers contained in the heat-resistant layer ranges from about 15% to 19% by weight to up to about 70%, 75%, 80%, 85% or 90% by weight in the nonwoven fiber thermal insulation layer.

[0206] The amount of fiber particles that the heat-resistant layer may contain ranges from about 3% by weight to up to about 60% by weight of the amount of inorganic fibers in the nonwoven fiber thermal insulation layer.

[0207] Without the addition of insulating particles, the inorganic fiber content is 95.2% in dry-laid and 95.5% in wet-laid. At the lowest level of aerogel filler loading, the inorganic fiber content is 72% for both dry and wet-laid processes. For dry-laid nonwoven fiber thermal insulation, the fibers are open (i.e., large clumps of fiber are separated, becoming less dense), which removes some loose particles. For wet-laid nonwoven fiber thermal insulation, the fibers are wet-cleaned, which removes more loose particles than the dry-laid opening process. Uncleaned SuperWool Plus from Morgan contains approximately 40% loose particles, representing an actual fiber content of 19%–43% in nonwoven fiber thermal insulation. For nonwoven fiber thermal insulation, a fiber content ranging from approximately 10% to up to approximately 80% may be required. Lower fiber content will require higher amounts of organic binder. Other additives may be included (e.g., flame retardants, heat-absorbing materials, infrared-reflecting materials, etc.).

[0208] The amount of inorganic thermal insulating particles that the heat-resistant layer may contain ranges from as low as about 10% by weight to as high as about 40%, 45%, 50%, 55%, or 60% by weight in nonwoven fiber thermal insulation layers. For example, a particle content of up to 60% can be obtained using a dry web forming process, and a particle content of up to 50% can be obtained using a wet web forming process.

[0209] The amount of organic binder that the heat-resistant layer may contain ranges from as low as about 2.5 wt%, 3.0 wt%, or 3.5 wt% to as high as about 7.5 wt%, 8.0 wt%, 8.5 wt%, 9.0 wt%, 9.5 wt%, or 10.0 wt% in the nonwoven fiber thermal insulation layer.

[0210] The heat-resistant layer according to any embodiment may have an installation (i.e., compression, e.g., between two battery cells) thickness ranging from about 0.5 mm to at most about 10 mm, wherein the lower limit may be about 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, and the upper limit may be about 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, or 2.5 mm. In some applications, the installation thickness can even reach approximately 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3.0mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4.0mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, 5.0mm, 6mm, 7mm, 8mm, 9mm, or even 10mm. The installation thickness of the nonwoven fiber thermal insulation layer is always less than its uninstalled (i.e., uncompressed) thickness. The performance of the heat-resistant layer is measured when it is in its installed (i.e., compressed) state.

[0211] The heat-resistant layer according to any embodiment may have an uncompressed (i.e., unpressurized) thickness ranging from about 1 mm to at most less than 20 mm, wherein the lower limit may be about 1 mm, 1.5 mm, 2 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3.0 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, or 3.5 mm, and the upper limit may be about 4.0 mm, 4.1 mm, 4.2 mm, 4.3 mm, 4.4 mm, 4.5 mm, 4.6 mm, 4.7 mm, 4.8 mm, 4.9 mm, 5.0 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, or 20 mm. The uncompressed thickness of the nonwoven fiber thermal insulation layer is always greater than its installed thickness.

[0212] The heat-resistant layer according to any embodiment may have a basis weight ranging from as low as about 250 g / m², 300 g / m², 350 g / m², or 400 g / m² for gaps of about 1 mm to up to about 800 g / m², 850 g / m², 900 g / m², 950 g / m², or 1000 g / m² for gaps of about 2 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, or less than 5.0 mm. In one embodiment, the inorganic thermal insulating particles are vermiculite, and the nonwoven fiber thermal insulation layer has a basis weight of 300 g / m² and is installed with gaps of about 1 mm. In another embodiment, the inorganic thermal insulating particles are silica aerogel, and the nonwoven fiber thermal insulation layer has a basis weight of 250 g / m² and is installed with gaps of about 1 mm.

[0213] The heat-resistant layer according to any embodiment may have a basis weight in the range of about 250 g / m² to at most about 400 g / m². Specifically, for example, when the inorganic thermal insulating particles are vermiculite and the gaps are about 1 mm, a basis weight in the range of about 300 g / m² to at most 400 g / m² may be required. When aerogel particles are used and the gaps are about 1 mm, a basis weight of about 250 g / m² may also be required. When the gaps are about 2.0 mm, a basis weight in the range of about 800 g / m² to at most about 1000 g / m² may be required.

[0214] According to any embodiment, the heat-resistant layer is prepared from or includes at least the following particles: inorganic (e.g., titanium dioxide, zirconium oxide, and / or silica) aerogels, dry gels, hollow or porous ceramic (e.g., glass, alumina, etc.) microspheres (e.g., bubbles, foam spheres, beads, etc.), unexpanded vermiculite, irreversibly or permanently expanded vermiculite (i.e., vermiculite that has been heated to a certain temperature and sustained for a period of time, causing the vermiculite particles to irreversibly or permanently expand to at least 10% and at most 100% of their expandability, or by means of forming a screen). Pre-expanded perlite before being used to form a barrier, or post-expanded after being placed in a nonwoven fiber thermal insulation monolayer; pyrolytic silica and other forms of porous silica; irreversibly or permanently expanded perlite (i.e., perlite that has been heated to a certain temperature and sustained for a period of time, causing the perlite particles to irreversibly or permanently expand to at least 10% and at most 100% of their expandability, or by pre-expanding before being used to form a barrier, or by post-expanding after being placed in a nonwoven fiber thermal insulation monolayer); unexpanded perlite; pumice; expanded clay; diatomaceous earth; titanium dioxide; and zirconium oxide.

[0215] The heat-resistant layer according to any embodiment may comprise an inorganic fiber matrix of fibers selected from the group consisting of: alkaline earth silicate fibers, refractory ceramic fibers (RCF), polycrystalline wool (PCW) fibers, basalt fibers, glass fibers, and silicate fibers. Glass fibers and silica fibers typically contain no or only nominal loose particles. PCW typically contains up to 5% loose particles, while alkaline earth silicate (AES) fibers contain up to 60% particles when uncleaned and contain a minimum of about 10%–30% loose particles when cleaned.

[0216] The heat-resistant layer according to any embodiment may include an organic binder in the form of polymer fibers (e.g., PE / PET, PET, FRPET), dry polymer powders (e.g., LDPE, polyamide, epoxy resin powders (3M SCOTCHCAST 265, 3MSCOTCHKOTE 6258)) or liquid binders (e.g., acrylic latex, ethylene vinyl acetate (EAF68) latex, silicone resin, polyurethane, etc.).

[0217] The heat-resistant layer according to any embodiment may be encapsulated by an organic encapsulation layer. The organic encapsulation layer may be in the form of a continuous layer, a discontinuous layer (e.g., having perforations, pores, or voids that allow gas to permeate the organic layer), or a combination of both. Alternatively, the organic layer may be in the form of a film, a loosely woven fabric, a woven or nonwoven fabric, an adhesive layer (e.g., a thermoplastic or hot-melt adhesive), or a combination thereof. An example of an organic layer is a copolyester polymer film.

[0218] The organic encapsulation layer can be a calendered layer, a hot melt coating, a sprayed layer, a dip coating, or a laminate (e.g., by using a pressure-sensitive adhesive or other adhesive), and can be sealed around the peripheral edges.

[0219] The heat-resistant layer according to any embodiment passes the UL94 V0 test.

[0220] The heat-resistant layer according to any embodiment comprises inorganic thermally insulating particles prepared from particles of an irreversibly or permanently expanding expandable material or comprising at least such particles. The expandable expandable material may irreversibly or permanently expand to at least about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90% to at most 100% of its expandability.

[0221] The inorganic thermal insulating particles in the heat-resistant layer may include pyrolytic silica particles with a surface area ranging from about 100 m² / g to at most about 400 m² / g.

[0222] The heat-resistant layer according to any embodiment can be assembled by using a wet web-forming process or a dry web-forming process to form a nonwoven fiber thermal insulation layer. See also Figure 4Inorganic thermal insulating particles are uniformly or consistently distributed throughout or within the nonwoven fiber thermal insulation layer. The layer can be exposed to heat for a period of time to cause the unexpanded particles to expand irreversibly. Heating can occur before or after the inorganic thermal insulating particles are placed within the nonwoven fiber thermal insulation layer.

[0223] In one particular aspect of this disclosure, at least one expanding and / or contracting surface expands (and / or contracts) when exposed to thermal energy (heat).

[0224] According to an advantageous aspect, when measured at 0.1 MPa according to the thermal insulation test method 2 described in the experimental section, the buffer article of this disclosure has a heat transfer time of up to 150°C for greater than 20 seconds, greater than 60 seconds, greater than 100 seconds, greater than 150 seconds, greater than 180 seconds, greater than 200 seconds, greater than 240 seconds, greater than 280 seconds, greater than 300 seconds, greater than 320 seconds, greater than 340 seconds, greater than 350 seconds, or even greater than 360 seconds.

[0225] According to another advantageous aspect of this disclosure, when measured at 0.1 MPa according to test method 2 described in the experimental section, the multilayer thermal barrier has a heat transfer time of up to 150°C in the range of 20 to 380 seconds, 40 to 380 seconds, 60 to 380 seconds, 100 to 380 seconds, 150 to 380 seconds, 180 to 380 seconds, 200 to 380 seconds, 250 to 380 seconds, or even 300 to 380 seconds.

[0226] According to another advantageous aspect of this disclosure, when measured at 1 MPa according to the thermal insulation test method 2 described in the experimental section, the multilayer thermal barrier has a heat transfer time of up to 150°C of greater than 20 seconds, greater than 40 seconds, greater than 60 seconds, greater than 80 seconds, greater than 100 seconds, greater than 120 seconds, greater than 140 seconds, or even greater than 150 seconds.

[0227] According to another advantageous aspect, when measured at 1 MPa according to the thermal insulation test method 2 described in the experimental section, the multilayer thermal barrier of this disclosure has a heat transfer time of up to 150°C in the range of 20 to 180 seconds, 40 to 180 seconds, 60 to 180 seconds, 100 to 180 seconds, 120 to 180 seconds, 140 to 180 seconds, or even 140 to 160 seconds.

[0228] According to another advantageous aspect, when measured according to the test methods described in the experimental section, the multilayer thermal barrier of this disclosure has a thermal conductivity of not more than 1 W / m / K, not more than 0.8 W / m / K, not more than 0.6 W / m / K, not more than 0.5 W / m / K, not more than 0.4 W / m / K, not more than 0.3 W / m / K, not more than 0.2 W / m / K, not more than 0.1 W / m / K, not more than 0.05 W / m / K, or even not more than 0.01 W / m / K.

[0229] In another advantageous aspect, when measured according to the test methods described in the experimental section, the multilayer thermal barrier of this disclosure has a thermal conductivity in the range of 0.01 W / m / K to 1 W / m / K, 0.05 W / m / K to 1 W / m / K, 0.1 W / m / K to 1 W / m / K, 0.2 W / m / K to 1 W / m / K, or even 0.2 W / m / K to 0.8 W / m / K.

[0230] Another advantage is that the multilayer thermal barrier of this disclosure has a V-0 classification when measured according to the UL-94 standard flammability test method.

[0231] According to an exemplary aspect of this disclosure, the multilayer thermal barrier has a thickness ranging from 100 micrometers to 20,000 micrometers, 100 micrometers to 15,000 micrometers, 100 micrometers to 10,000 micrometers, 100 micrometers to 8,000 micrometers, 100 micrometers to 6,000 micrometers, 200 micrometers to 5,000 micrometers, 300 micrometers to 5,000 micrometers, 300 micrometers to 4,500 micrometers, 300 micrometers to 4,000 micrometers, 500 micrometers to 4,000 micrometers, 1,000 micrometers to 3,000 micrometers, 1,000 micrometers to 2,500 micrometers, 1,500 micrometers to 2,500 micrometers, or even 2,000 micrometers to 2,500 micrometers.

[0232] According to another aspect, this disclosure relates to a method for manufacturing a multilayer thermal barrier as described above, wherein the method includes the following steps:

[0233] a) Provide a porous foam layer as described above;

[0234] b) Provide one or more heat-resistant layers as described above; and

[0235] c) A heat-resistant layer is laminated on one or more surfaces of a porous foam layer, or a porous foam layer is laminated on one or more surfaces of a heat-resistant layer.

[0236] In another aspect, this disclosure relates to rechargeable energy storage systems, particularly battery modules, that include multilayer thermal barrier articles as described above.

[0237] In another aspect, this disclosure relates to a battery module comprising a plurality of battery cells separated from each other by gaps and a multilayer thermal barrier as described above positioned in the gaps between the battery cells.

[0238] Suitable battery modules, battery sub-cells, and methods of manufacturing thereof used herein are described, for example, in EP-A1-3352290 (Goeb et al.), particularly Figures 1-3 The contents of the patent are incorporated herein by reference in their entirety in paragraphs

[0016] to

[0035] .

[0239] According to an advantageous aspect of the battery module disclosed herein, the battery cells used herein are selected from the group consisting of pouch-shaped energy storage battery cells and prismatic energy storage battery cells, particularly from the group consisting of pouch-shaped energy storage battery cells.

[0240] According to another aspect, this disclosure relates to a method for manufacturing a battery module, the method comprising the following steps:

[0241] a) Provide multiple battery cells separated from each other by gaps; and

[0242] b) Position the multi-layer thermal barrier as described above in the gaps between the battery cells.

[0243] According to another aspect, this disclosure relates to a method for cushioning at least one expanding (and / or contracting) surface, the method comprising the step of applying a cushioning article as described above to at least a portion of at least one expanding (and / or contracting) surface. In a particular aspect, at least one expanding (and / or contracting) surface expands (and / or contracts) upon exposure to thermal energy (heat).

[0244] According to another aspect, this disclosure relates to the use of the cushioning articles described above in industrial applications, particularly for thermal management applications, more particularly in the transportation industry, and even more particularly in the automotive, aerospace and aviation industries.

[0245] According to another aspect, this disclosure relates to the use of the buffer articles described above as thermal barriers, particularly thermal runaway barriers.

[0246] In another aspect, this disclosure relates to the use of the buffer articles described above as thermal barrier spacers in rechargeable energy storage systems, particularly battery modules, and especially thermal runaway barrier spacers.

[0247] In another aspect, this disclosure relates to the use of the buffer article as described above as a thermal barrier spacer, particularly a thermal runaway barrier spacer, between multiple battery cells in a rechargeable energy storage system, particularly a battery module.

[0248] In another aspect, this disclosure relates to the use of the buffer article as described above as a buffer spacer, particularly between multiple battery cells, in a rechargeable energy storage system, particularly a battery module.

[0249] In another aspect, this disclosure relates to the use of the cushioning article as described above as a cushioning spacer for cushioning at least one expanding (and / or contracting) surface, wherein at least one expanding surface expands (and / or contracts) particularly when exposed to heat energy (heat).

[0250] Exemplary Embodiments

[0251] 1. A thermally porous foam barrier, the thermally porous foam barrier comprising:

[0252] Organosilicon porous foam layer,

[0253] The insulating particles within the porous foam layer

[0254] The insulating particles described herein have an average particle size greater than 50 micrometers.

[0255] The thermally porous foam barrier has a thermal conductivity of less than 0.2 W / mk.

[0256] 2. The thermally porous foam barrier according to any one of the foregoing embodiments, wherein the insulating particles are selected from aluminum hydroxide (ATH) and vermiculite.

[0257] 3. The thermal porous foam barrier according to any one of the foregoing embodiments, wherein the insulating particles are vermiculite.

[0258] 4. The thermally porous foam barrier according to any one of the foregoing embodiments, wherein the insulating particles are unexpanded vermiculite.

[0259] 5. The thermally porous foam barrier according to any one of the foregoing embodiments, wherein the insulating particles are expanded vermiculite.

[0260] 6. The thermal porous foam barrier according to any one of the foregoing embodiments, wherein the multilayer thermal barrier exhibits a pressure of at least 35 kPa, or 40 kPa, or 50 kPa when subjected to 20% compression.

[0261] 7. The thermal porous foam barrier according to any one of the foregoing embodiments, wherein the multilayer thermal barrier exhibits a pressure of less than 1,750 kPa, or 1,500 kPa, or 1,250 kPa, or 1,000 kPa, or 750 kPa when subjected to 60% compression.

[0262] 8. The thermal porous foam barrier according to any one of the foregoing embodiments, wherein the cold plate needs to reach 150°C for at least 100 seconds, or 200 seconds, or 300 seconds, or 400 seconds in the HCST test.

[0263] 9. The thermal porous foam barrier according to any one of the foregoing embodiments, wherein the cold plate needs to reach 150°C for at least 600 seconds, or 700 seconds, or 800 seconds, or 900 seconds, or 1000 seconds in the HCST test.

[0264] 10. The thermally porous foam barrier according to any one of the foregoing embodiments, wherein the thermally insulating porous foam layer comprises a material selected from the group consisting of: silicone elastomers, fluorinated silicone rubbers, aromatic polyamides, polybenzimidazoles, polysulfides, polyimides, polysulfones, polyetherketones, fluorocarbons, polyisoprene, polybutadiene, polychloroprene, polyurethanes, polyolefins (particularly polyethylene, polypropylene, and ethyl vinyl acetate), polystyrene, and any combination or mixture thereof.

[0265] 11. The thermally porous foam barrier according to any one of the foregoing embodiments, wherein the thermally insulating porous foam layer comprises an organopolysiloxane polymer.

[0266] 12. The thermally porous foam barrier according to any one of the foregoing embodiments, wherein the thermally insulating porous foam layer can be obtained from a curable and in-situ foamable precursor.

[0267] 13. The thermally porous foam barrier according to any one of the foregoing embodiments, wherein the thermally insulating porous foam layer can be obtained by an addition-cured bipartite organopolysiloxane composition.

[0268] 14. The thermally porous foam barrier according to any one of the foregoing embodiments, wherein the thermally insulating porous foam layer can be obtained from a precursor, the precursor comprising:

[0269] a) At least one organopolysiloxane compound A;

[0270] b) At least one organohydrogen polysiloxane compound B containing at least two, in particular at least three, hydrogen atoms per molecule;

[0271] c) At least one hydroxyl-containing compound C;

[0272] d) An effective amount of curing catalyst D, especially a platinum-based curing catalyst; and

[0273] e) Optional foaming agent.

[0274] 15. The thermally porous foam barrier according to any one of the foregoing embodiments, wherein the thermally insulating porous foam layer can be obtained from a precursor, the precursor comprising:

[0275] a) At least one organopolysiloxane compound A;

[0276] b) At least one organohydrogen polysiloxane compound B containing at least two, in particular at least three, hydrogen atoms per molecule;

[0277] c) At least one hydroxyl-containing compound C;

[0278] d) An effective amount of curing catalyst D, especially a platinum-based curing catalyst; and

[0279] e) Optional foaming agent,

[0280] The at least one organopolysiloxane compound A has the following formula:

[0281]

[0282] in:

[0283] R and R” are independently chosen from C1 to C2. 30 The group consisting of hydrocarbon groups, and in particular, R is an alkyl group selected from the group consisting of methyl, ethyl, propyl, trifluoropropyl and phenyl, and optionally, R is a methyl group;

[0284] R' is C1 to C 20 The alkenyl group, and in particular, R' is selected from the group consisting of vinyl, allyl, hexenyl, decenyl and tetradecenyl, and more particularly, R' is a vinyl group;

[0285] R” is in particular an alkyl group, such as methyl, ethyl, propyl, trifluoropropyl, phenyl, and especially, R” is a methyl group; and

[0286] n is an integer with values ​​in the range of 5 to 1000, particularly 5 to 100.

[0287] 16. The thermally porous foam barrier according to any one of the foregoing embodiments, wherein the thermally insulating porous foam layer is formed from a precursor that undergoes foaming through a gaseous compound.

[0288] 17. The thermally porous foam barrier according to any one of the foregoing embodiments, wherein the thermally insulating porous foam layer has a density of 200 kg / m³. 3 Up to 500kg / m 3 The density within the range.

[0289] 18. The thermally porous foam barrier according to any one of the foregoing embodiments, wherein the thermally insulating porous foam layer has a heat transfer time of 140 to 200 seconds at 150°C in the HCST test.

[0290] 19. The thermally porous foam barrier according to any one of the foregoing embodiments, wherein the thermally insulating porous foam layer is capable of undergoing a ceramicization process at a temperature in the range of 200°C to 600°C.

[0291] 20. The thermally porous foam barrier according to any one of the foregoing embodiments, wherein the thermally insulating porous foam layer comprises a non-flammable filler material, the non-flammable filler material being particularly selected from the group consisting of inorganic fibers, particularly from the group consisting of mineral fibers, mineral wool, silicate fibers, ceramic fibers, glass fibers, carbon fibers, graphite fibers, asbestos fibers, aramid fibers, and any combination or mixture thereof.

[0292] 21. The thermally porous foam barrier according to any one of the foregoing embodiments, wherein the thermally insulating porous foam layer comprises a filler material selected from aluminum hydroxide (ATH), magnesium hydroxide (MDH), calcium magnesium carbonate-magnesium hydromagnesium ore, talc, clay, boron-based flame retardants, molybdenum compounds, tin compounds, antimony compounds, expandable graphite, gypsum, calcium carbonate, carbide fillers, metals, metal oxides, sulfates, sulfides, silicates, glass, titanates, and any combination or mixture thereof.

[0293] 22. The thermal porous foam barrier according to any one of the foregoing embodiments, wherein the thermal porous foam barrier passes the UL94 V0 test.

[0294] 23. A battery module comprising a thermally porous foam barrier according to any one of the foregoing embodiments.

[0295] Examples

[0296] This disclosure is further illustrated by the following examples. These examples are for illustrative purposes only and are not intended to limit the scope of the appended claims. Where applicable, brand names and trademark names are displayed in all uppercase letters and / or numbers.

[0297] Test Methods :

[0298] 1) Compression Test

[0299] Compression tests were performed in compression mode using a tensile testing machine from Zwick. The sample diameter was 50.8 mm and the thickness was >1000 μm. The test was performed at 23°C. The upper plate of the compression testing machine was moved at a speed of 1 mm / min until the maximum force of 2 MPa was reached. Then, the upper plate was moved back to the starting position at the same speed of 1 mm / min to perform a full load / unload cycle. The compressive force (in kPa) required to reach various compression values ​​was recorded.

[0300] Samples with a diameter of 50.8 mm were prepared. A monolayer sample was loaded between parallel plates in an Instron Model 5581 apparatus located in Building 280-W320 using a 5 kN load cell. The compression response was measured using a modified ASTM 3744. Three consecutive compressions from 0% to 70% were recorded with a constant displacement of 5 mm / min. For each cycle, a preload of 725 Pa was applied to the sample to determine the initial thickness. Data from the third cycle were reported according to ASTM standards to eliminate the Mullins effect.

[0301] 2) Coating Weight

[0302] The coating weight of the polymer foam layer was measured by weighing a 100 cm² sample cut from the sample layer using a circular cutter. The coating weight was then converted to g / m².

[0303] 3) Thickness

[0304] The thickness of the polymer foam layer was measured using a thickness gauge with a minimum base area of ​​650 mm². The pressure on the thickness gauge base was maintained at a maximum of 725 Pa.

[0305] A sample with a diameter of 50.8 mm was prepared. The monolayer sample was mounted between parallel plates on a Gustin-Bacon Measure-O-Matic. A mass of 33 g was applied to simulate a stress of 160 Pa on the sample. The thickness was recorded.

[0306] 4) Hot / Cold Side Test (HCST)

[0307] In a 10kN tensile testing machine (purchased from ZWICKROELL of Ulm, Germany), the top platen was heated to 800°C, and the sample was placed on a bottom pressure plate embedded with thermocouples, set at ambient temperature. A heat shield was used to cover the sample to ensure it remained at ambient temperature. The sample thickness was measured under a load of 4.9 kPa before testing. The heat shield was then removed, and the upper platen was lowered to this thickness at a closing rate of 250 mm / min. The test was then started at 0 seconds. The closing rate was then reduced to 2 mm / min, and the upper platen was lowered while maintaining a pressure of 1 MPa. The time it took for the sample to reach 150°C (302℉) was recorded and designated as t(150°C). As will be shown in the results, for some samples tested within a specified time period (e.g., 500 seconds), the cold plate did not reach 150°C. In those cases, the result is recorded as requiring more than 500 seconds for the cold plate to reach 150°C, even if the cold plate does not reach 150°C within the specified time. The base plate is made of stainless steel with a heat capacity of 450 J / (kg*K) and a thickness of 30 mm. The upper hot plate and the bottom cold plate have the same length and width, and each weighs 1260 g.

[0308] Thermal barrier performance was tested on an MTS Model 43 device (3M Asset ID 1592446) with a hot surface temperature of 600°C and a constant stress of 100 kPa (EP-23032-1). Additional measurements were performed with a constant gap of 1.6 mm (EP-22347-1). A 65x65 mm sample size was used. Sample mass, response temperature, gap thickness, and pressure were recorded.

[0309] 5) Mechanical Cycling Test

[0310] Cyclic compression tests were performed in compression mode using a material testing instrument from Zwickroll. The samples had a diameter of 50.8 mm and a thickness greater than 1000 micrometers. The test was performed at ambient temperature (approximately 23°C). The upper plate of the compression tester was moved at a speed of 25 mm / min until a force of 0.15 MPa was reached. Then, the upper plate was moved up and down frequently at a rate of 1 mm / min until the required number of cycles was reached. Cyclic amplitude represents the expansion and contraction of the battery cell during charging and discharging (i.e., battery cell breathing). Maximum amplitudes occurred when the battery was fully discharged (SOC equals 0%) and fully charged (100% equals SOC). See also Figure 6(BOL indicates start of life, and EOL indicates end of life). The full-amplitude height is typically 0.5 mm and depends on the actual cell chemistry. Additionally, continuous irreversible cell swelling increases incrementally with each cycle, representing an irreversible change at the Li-ion electrode. Typical irreversible swelling is approximately 2% to 8% of the cell thickness and cell chemistry. Therefore, irreversible swelling ranges from approximately 0.5 mm to approximately 2.0 mm. Minimum and maximum pressures for each cycle are recorded and reported.

[0311] Particle Size

[0312] Particle size was analyzed using a Beckman Coulter LS13 320 via laser scattering. The 50% distribution percentage values ​​were recorded. Data from data tables were used where available.

[0313] Thermal Conductivity

[0314] Thermal conductivity was measured using a TA DTC-300 according to ASTM E1530. Measurements were performed at 50°C, 100°C, and 200°C at 21 PSI. The acquired data and reported averages are reproduced. Data are reported in GID 305293.

[0315] Porous Foam Construction

[0316] Raw Materials :

[0317] The following raw materials are used in the examples or may be used as substitutes for or in combination with the components used in the examples:

[0318] DOWSIL 3-8209 is a two-part room temperature curable silicone rubber foam formulation, which is commercially available under the trade name DOWSIL from Dow Chemical Company, Midland, MI, United States.

[0319] DOWSIL 3-8235 is another two-part room temperature curable silicone rubber foam formulation, which is commercially available under the trade name DOWSIL from Dow Chemical Company in Midland, Michigan, USA.

[0320] BLUESIL RT Foam 3242 is an open-cell silicone foam that is commercially available under the trade name BLUESIL from Elkem Silicones, Oslo, Norway.

[0321] COATFORCE CF30 is a silicate fiber and COATFORCE CF50 is a mineral fiber, both sourced from Rockwool BV, The Netherlands.

[0322] MARTINAL OL-104 LEO is a fine aluminum trioxide (ATH) with a d50 ranging from about 1.7 microns to about 2.1 microns. It was obtained from Martinswerk GmbH in Bergheim, Germany, under the trade name MARTINAL OL-104 LEO.

[0323] IMERSEAL 74S is a surface-treated calcium carbonate, acquired under the trade name IMERSEAL from Imerys S.A., Paris, France.

[0324] Porous Foam Preparation Examples :

[0325] An exemplary handmade porous foam layer is prepared according to the following procedure:

[0326] Using a SPEEDMIXER, the identified materials (see Table 1) were added by weight to each component A and B of the silicone foam at 1500 RPM for 120 seconds. CF50 was mixed with OL-104 LEO. The amounts of materials identified by weight as in Table 1 were added at a 1:1 volumetric mixing ratio to a 200 mL two-part cassette system (200 mL F System cassette) from Adchem GmbH. The two-part silicone system was mixed using a static mixer (MFH 10-18T) with a 4 bar pressure dispensing gun. After releasing 100 g of the mixed silicone into the container, the mixture was manually homogenized for 10 seconds using a wooden spatula. The mixture was then coated with a doctor blade coater between two layers of Hostaphan RN 50 / 50 solid film with a gap thickness of 600 micrometers (PE1 and PE2). The resulting sheet began to expand, and the reaction was completed by placing the sheet in an 80°C forced-air oven for ten minutes. Thickness, coating weight, density, thermal conductivity, and compression tests were performed, and the results are also included in Table 1.

[0327]

[0328] Parts A and B were prepared separately using a rapid mixer. The prepared materials were then mixed and applied between Laufenber 78 release liner pieces. The coating was set to a 17-mil gap in a lab-cut bar. The coated samples were exposed to room temperature for 1 minute, then cured in a 90°C oven for 18 minutes.

[0329]

[0330] Average Material Properties

[0331]

[0332] *Note: Arithmetic mean of the two particle distributions. Actual distributions are highly polarized, and the average is for reference only. Non-normal distribution.

[0333] Compression Response

[0334] For vermiculite, due to its stronger nucleation, smaller pores, and thinner thickness, reducing the filler diameter increases stiffness. Larger filler diameters increase thickness, thus reducing density and stiffness, and resulting in more efficient foaming. See also Figure 6 .

[0335]

[0336]

[0337] For ATH (Alternating Threatened Blend), due to stronger nucleation, smaller pores, and less thickness, reducing the filler diameter also increases stiffness. Reduced thickness increases density and stiffness. Larger fillers improve foaming efficiency. See also... Figure 7 .

[0338]

[0339]

[0340] *Note: Arithmetic mean of two particle distributions. Actual distributions are highly polarized, and the average is for reference only. Most small fillers may suppress foaming and mask the effects of larger fillers.

[0341] Note*: 122-2 has a basis weight that is about 70% higher than that of 122-3, and a density that is 10% lower. Similar densities result in similar CFD (compressive force deflection).

[0342] Comparing larger particles, a similar decrease in stiffness was observed at approximately the same density. It has been observed that the compressive response is largely density-controlled. Similarly, larger particles increase foam thickness, thereby reducing both density and stiffness. See also Figure 8 .

[0343]

[0344]

[0345] Similar particle sizes do not result in the same thickness. Using small vermiculite particles reduces foam thickness, thereby increasing density and, consequently, stiffness. See also Figure 9 .

[0346]

[0347]

[0348] By using large vermiculite particles, a softer compressive force can be obtained at the same density compared to using smaller ATH particles. See also Figure 10 .

[0349]

[0350]

[0351]

[0352]

[0353] Thermal Conductivity

[0354] By using large-particle vermiculite filler, the density and stiffness of the foam are reduced. At 21 PSI, vermiculite has a lower thermal conductivity per unit density than comparable fillers. See also Figure 11 .

[0355] Thermal Runaway

[0356] By using large-particle vermiculite filler, the foam exhibits superior transient thermal properties during thermal runaway events. At the same density and thickness (constant gap), the large vermiculite particle surface exhibits superior thermal properties. Under the same stress (constant load), the increased foam thickness due to the large particles improves performance. See also Figure 12A and Figure 12B .

[0357]

[0358] Vermiculite Expansion

[0359] Figure 13A , Figure 14A and Figure 15A The sample prepared exactly as is is shown, and Figure 13B , Figure 14B and Figure 15BThe corresponding sample after thermal expansion at 600℃ is shown.

[0360] Thermal Runaway

[0361] At the same density and stiffness, large-diameter vermiculite exhibits superior transient thermal properties compared to large-diameter NS. While larger diameter particles reduce stiffness, the vermiculite sample demonstrates better thermal performance. See also Figure 16A and Figure 16B .

[0362] At the same density and with reduced stiffness, large-diameter vermiculite exhibits superior transient thermal properties compared to small-particle ATH. It has been found that large-diameter particles typically reduce stiffness, thus decreasing thermal properties under constant pressure; however, vermiculite exhibits improved performance due to its thickness retention. See also Figure 17A , Figure 17B and Figure 18 .

[0363]

Claims

1. A thermally porous foam barrier, the thermally porous foam barrier comprising: Organosilicon porous foam layer, The insulating particles within the porous foam layer The insulating particles described herein have an average particle size greater than 50 micrometers. The thermally porous foam barrier has a thermal conductivity of less than 0.2 W / mk.

2. The thermally porous foam barrier according to any one of the preceding claims, wherein the insulating particles are selected from aluminum hydroxide (ATH) and vermiculite.

3. The thermal porous foam barrier according to any one of the preceding claims, wherein the multilayer thermal barrier exhibits a pressure of at least 35 kPa when subjected to 20% compression.

4. The thermal porous foam barrier according to any one of the preceding claims, wherein the multilayer thermal barrier exhibits a pressure of less than 1,750 kPa when subjected to 60% compression.

5. The thermal porous foam barrier according to any one of the preceding claims, wherein the cold plate requires at least 600 seconds to reach 150°C in the HCST test.

6. The thermally porous foam barrier according to any one of the preceding claims, wherein the thermally insulating porous foam layer comprises a material selected from the group consisting of: silicone elastomers, fluorinated silicone rubbers, aromatic polyamides, polybenzimidazoles, polysulfides, polyimides, polysulfones, polyetherketones, fluorocarbons, polyisoprene, polybutadiene, polychloroprene, polyurethanes, polyolefins (particularly polyethylene, polypropylene, and ethyl vinyl acetate), polystyrene, and any combination or mixture thereof.

7. The thermally porous foam barrier according to any one of the preceding claims, wherein the thermally insulating porous foam layer comprises an organopolysiloxane polymer.

8. The thermally porous foam barrier according to any one of the preceding claims, wherein the thermally insulating porous foam layer can be obtained from a curable and in-situ foamable precursor.

9. The thermally porous foam barrier according to any one of the preceding claims, wherein the thermally insulating porous foam layer can be obtained from a precursor, the precursor comprising: a) At least one organopolysiloxane compound A; b) At least one organohydrogen polysiloxane compound B containing at least two, in particular at least three, hydrogen atoms per molecule; c) At least one hydroxyl-containing compound C; d) An effective amount of curing catalyst D, especially a platinum-based curing catalyst; and e) Optional foaming agent.

10. The thermally porous foam barrier according to any one of the preceding claims, wherein the thermally insulating porous foam layer has a density of 200 kg / m³. 3 Up to 500kg / m 3 The density within the range.

11. The thermally porous foam barrier according to any one of the preceding claims, wherein the thermally insulating porous foam layer has a heat transfer time of 140 to 200 seconds at 150°C in an HCST test.

12. The thermally porous foam barrier according to any one of the preceding claims, wherein the thermally insulating porous foam layer is capable of undergoing a ceramicization process at a temperature in the range of 200°C to 600°C.

13. The thermally porous foam barrier according to any one of the preceding claims, wherein the thermally insulating porous foam layer comprises a non-flammable filler material selected from the group consisting of inorganic fibers.

14. The thermally porous foam barrier according to any one of the preceding claims, wherein the thermally insulating porous foam layer comprises a filler material selected from aluminum hydroxide (ATH), magnesium hydroxide (MDH), calcium magnesium carbonate-magnesium hydromagnesium ore, talc, clay, boron-based flame retardants, molybdenum compounds, tin compounds, antimony compounds, expandable graphite, gypsum, calcium carbonate, carbide fillers, metals, metal oxides, sulfates, sulfides, silicates, glass, titanates, and any combination or mixture thereof.

15. A battery module comprising a thermally porous foam barrier according to any one of the preceding claims.

Images