Thermal insulation composite material and product made of thermal insulation composite material

Abstract

Insulating composites and articles formed therefrom are described herein. The thermally insulating composite includes a fibrillated polymer matrix, thermally insulating particles, and additional particle components, such as one or more of reinforcing fibers, expandable microspheres, and opacifiers. The thermally insulating particles and additional particle components are permanently embedded within the fibrillated polymer matrix. The insulating composite acts as a heat propagation barrier when exposed to a temperature sufficient to partially or fully volatilize the fibrillated polymer matrix within the insulating composite. The thermally insulating composite is suitable for use in applications and / or articles having at least one heat-sensitive component capable of releasing energy (typically upon failure of the component) sufficient to generate a temperature at which the fibrillated polymer matrix within the thermally insulating composite is partially or fully volatilized, however, the thermal insulation composite still provides a sufficient thermal insulation effect to protect one or more adjacent thermal sensitive components from damage.

Description

Technical Field

[0001] The present disclosure relates generally to thermal insulation materials and articles made therefrom, and more particularly to thermal insulation composites and articles made therefrom that are capable of maintaining thermal insulation and thermal barrier properties when exposed to elevated temperatures. Background Art

[0002] High-temperature thermal insulation materials are often incorporated into electronic devices to protect sensitive components located therein or to protect users from uncomfortably high heat radiated by heat sources. Certain applications, such as battery packs, may benefit from the use of high-temperature thermal insulation materials, which can also be used as high-temperature thermal insulation composites capable of withstanding extremely high temperatures, such as thermal runaway events in lithium-ion batteries. However, many conventional thermal insulation materials are difficult to process, difficult to form into the desired shape or thickness for the intended application, and / or they may be subject to excessive dusting.

[0003] Various protective articles require insulating materials that are thin, strong, conformable, compressible, and have thermal insulation properties (e.g., thermal conductivity sufficient for the intended use). However, some insulating materials are used in applications or devices where high temperature events may occur, such as when a component within the device fails and releases energy sufficient to trigger an adverse event (e.g., a thermal runaway event). The resulting temperature increase may damage other components inside or outside the device. In some embodiments, the high temperature event may be sufficient to damage a second component, wherein damage to the second component may trigger a second high temperature event (e.g., an adjacent cell within a high energy battery (e.g., a lithium ion battery)).

[0004] Therefore, there is a need for a high-temperature thermal insulation composite material suitable for high-temperature use that is thin, conformable, thermally insulating, and can function as a high-temperature thermal insulation composite material when exposed to high temperatures. Summary of the Invention

[0005] According to one aspect ("Aspect 1"), an insulating composite material comprises 50 weight percent or less of a fibrillated polymer matrix, greater than 40 weight percent of insulating particles, wherein the insulating particles are selected from the group consisting of fumed silica, amorphous silica, colloidal silica, precipitated silica, fused silica, silica gels, silica xerogels, silicates, fumed metal oxides, and combinations thereof, and greater than about 1 weight percent of a combined total amount of additional particulate components selected from the group consisting of one or more opacifiers, one or more reinforcing fibers, one or more expandable microspheres, and any combination thereof, wherein the weight percents are based on the total weight of the final insulating composite material, and wherein the insulating particles and additional particulate components are durably embedded in the fibrillated polymer matrix.

[0006] According to another aspect of aspect 1 ("Aspect 2"), the thermal insulation particles are fumed silica particles.

[0007] According to another aspect of aspect 1 or aspect 2 ("Aspect 3"), the thermal insulation composite material is a tube, a tape, or a sheet having a thickness or a wall thickness of 5 mm or less.

[0008] According to another aspect of any of aspects 1-3 ("Aspect 4"), the fibrillated polymer matrix comprises a polyolefin, an ultra-high molecular weight polyethylene, a fluoropolymer, polytetrafluoroethylene, expanded polytetrafluoroethylene, a polyurethane, a polyester, a polyamide, or any combination thereof.

[0009] According to another aspect of any one of aspects 1-4 ("Aspect 5"), the polymer is polytetrafluoroethylene (ePTFE), ultra-high molecular weight polyethylene (UHMWPE), or a combination thereof.

[0010] According to another aspect of any one of aspects 1-5 ("Aspect 6"), the combined total amount of the additional particulate components comprises greater than 1% by weight of one or more sunscreens.

[0011] According to another aspect of any one of aspects 1-6 ("Aspect 7"), the additional particulate component comprises up to 30% by weight of expandable microspheres.

[0012] According to another aspect of any one of aspects 1 to 7 ("Aspect 8"), the sunscreen is selected from carbon black, titanium dioxide, aluminum oxide, zirconium dioxide, iron oxide, silicon carbide, molybdenum silicide, manganese oxide, polydialkylsiloxanes wherein the alkyl group contains 1 to 7 carbon atoms, or any combination thereof.

[0013] According to another aspect of any of aspects 1-8 ("Aspect 9"), the one or more reinforcing fibers comprise carbon fibers, glass fibers, aluminoborosilicate fibers, or combinations thereof.

[0014] According to one aspect (“Aspect 10”), a thermal insulation composite comprises less than 50 weight percent of a fibrillated polymer matrix, insulating particles selected from the group consisting of fumed silica, amorphous silica, colloidal silica, precipitated silica, fused silica, silica gels, silica xerogels, silicates, fumed metal oxides, and combinations thereof, greater than about 1 weight percent of at least one opacifier, up to 25 weight percent of reinforcing fibers, and less than 20 weight percent of expandable microspheres, wherein the weight percents are based on the total weight of the thermal insulation composite in a final state, and wherein the insulating particles and additional particulate components are durably embedded in the fibrillated polymer matrix.

[0015] According to another aspect of aspect 10 ("Aspect 11"), the thermal insulation particles are fumed silica particles.

[0016] According to another aspect of aspect 10 or aspect 11 ("Aspect 12"), the thermal insulation composite material is a tube, a tape, or a sheet having a thickness or a wall thickness of 5 mm or less.

[0017] According to another aspect of aspects 10-12 ("Aspect 13"), the fibrillated polymer matrix comprises a polyolefin, an ultra-high molecular weight polyethylene, a fluoropolymer, polytetrafluoroethylene, expanded polytetrafluoroethylene, a polyurethane, a polyester, a polyamide, or any combination thereof.

[0018] According to another aspect of aspects 10-13 ("Aspect 14"), the polymer is expanded polytetrafluoroethylene (ePTFE), ultra-high molecular weight polyethylene, or a combination thereof.

[0019] According to another aspect of aspects 10-14 ("Aspect 15"), the combined total amount of the additional particulate components comprises greater than 10% of one or more sunscreens.

[0020] According to another aspect of aspects 10-15 ("Aspect 16"), the additional particulate component comprises up to 30% by weight of expandable microspheres.

[0021] According to another aspect of aspects 10-16 ("Aspect 17"), the sunscreen is selected from carbon black, titanium dioxide, aluminum oxide, zirconium dioxide, iron oxide, silicon carbide, molybdenum silicide, manganese oxide, polydialkylsiloxanes wherein the alkyl group contains 1 to 4 carbon atoms, or any combination thereof.

[0022] According to another aspect of aspects 10-17 ("Aspect 18"), the one or more reinforcing fibers comprise carbon fibers, glass fibers, aluminoborosilicate fibers, or combinations thereof.

[0023] According to another aspect (“Aspect 19”), an article comprises the thermal insulation composite material as described in any one of Aspects 1-9.

[0024] According to another aspect (“Aspect 20”), an article comprises the thermal insulation composite material of any one of Aspects 10-18.

[0025] According to another aspect (“Aspect 21”), use of the thermal insulation composite material according to any one of Aspects 1 to 9 for preventing heat propagation in a lithium-ion battery.

[0026] According to another aspect (“Aspect 22”), use of the thermal insulation composite material according to any one of Aspects 10 to 18 for preventing heat propagation in a lithium-ion battery.

[0027] According to another aspect ("Aspect 23"), an article comprises a first component capable of generating a high temperature event comprising a first temperature, and an insulating composite material positioned between the first component and the second component, wherein a first side of the insulating composite material faces the first component and an opposite side faces the second component; the insulating composite material comprises (1) greater than or equal to about 40 weight percent insulating particles, wherein the insulating particles are selected from the group consisting of: fumed silica, amorphous silica, colloidal silica, precipitated silica, fused silica, silica gel, silica xerogel, silicates, fumed metal oxides, and combinations thereof, (2) less than or equal to about 60 weight percent of a fibrillated polymer matrix, and (3) 1 weight percent to 45 weight percent of one or more additional particulate components selected from the group consisting of: one or more sunscreens, one or more reinforcing fibers, one or more expandable microspheres, and combinations thereof, wherein the weight percent is based on the total weight percent of the insulating composite material in a final state, and wherein the insulating particles and the additional particulate components are durably embedded in the fibrillated polymer matrix.

[0028] According to another aspect of aspect 23 ("Aspect 24"), the thermal insulation particles are fumed silica particles.

[0029] In one aspect (“Aspect 25”), a multilayer insulating composite material comprises a first layer and a second layer, each of the first layer and the second layer comprising (1) greater than or equal to about 40 weight percent insulating particles, wherein the insulating particles are selected from the group consisting of: fumed silica, amorphous silica, colloidal silica, precipitated silica, fused silica, silica gels, silica xerogels, silicates, fumed metal oxides, and combinations thereof, (2) less than or equal to about 60 weight percent of a fibrillated polymer matrix, and (3) 1 weight percent to 45 weight percent of one or more additional particulate components selected from the group consisting of: one or more sunscreens, one or more reinforcing fibers, one or more expandable microspheres, and combinations thereof, such that the total weight percent equals 100 weight percent, wherein the one or more additional particulate components vary in one or more of chemical composition, particle size, and particle size distribution along a first thickness of the first layer, and wherein the additional particulate components vary in one or more of chemical composition, particle size, and particle size distribution along a second thickness of the second layer.

[0030] According to another aspect of aspect 25 ("Aspect 26"), it includes a third layer, wherein the third layer includes one or more additional particulate components, and the additional particulate components vary along the thickness of the third layer in one or more aspects of chemical composition, particle size, and particle size distribution.

[0031] According to another aspect of aspect 25 or aspect 26 ("Aspect 27"), the one or more additional components are sunscreens and the first layer comprises a sunscreen having a first particle size distribution, the second layer comprises a sunscreen having a second particle size distribution, and the third layer comprises a sunscreen having a third particle size distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification. They illustrate embodiments of the disclosure and together with the description serve to explain the principles of the disclosure.

[0033] Figure 1A is a schematic cross-sectional view of an insulating composite material having insulating particles and additional particles whose components vary along its thickness, according to some embodiments.

[0034] Figure 1B is a schematic cross-sectional view of a multilayer thermal insulation composite material having different particle size distributions in different layers according to some embodiments.

[0035] Figure 2 is a schematic diagram of a testing system for evaluating the performance of a sample in a Protective Heat Propagation Barrier Assay according to some embodiments.

[0036] Figure 3 A schematic side view of a contact compression zone is shown when testing a sample in the Protective Heat Transmission Barrier Test, according to some embodiments. DETAILED DESCRIPTION

[0037] It should be noted that the drawings referred to herein are not necessarily drawn to scale and may be exaggerated in order to illustrate aspects of the present disclosure, and in this regard the drawings should not be considered limiting.

[0038] As used herein, "ultrahigh molecular weight" refers to polymers with a number average molecular weight ranging from 1,000,000 g / mol to 10,000,000 g / mol. In some embodiments, the polymer may have a number average molecular weight of 3,000,000 to 10,000,000 or 5,000,000 to 10,000,000.

[0039] Unless otherwise specified, as used herein, the term "weight percent" or "wt%" refers to the weight percent of a component based on the total weight percent of the final thermal insulation composite (i.e., after removing the lubricant). "Weight%" can be defined as the mass of the component divided by the total mass of the thermal insulation component (after removing the lubricant) multiplied by 100.

[0040] As used herein, "additional particulate components" include sunscreen(s), reinforcing fibers, expandable microspheres, and any combination thereof.

[0041] As used herein, the term "high temperature" refers to a temperature sufficient to partially or completely degrade (e.g., depolymerize, chain scission, and / or volatilize) the fibrillated polymer matrix within the high temperature insulation composite material described herein. In one aspect, "high temperature" is a temperature sufficient to partially or completely volatilize the fibrillated polymer within the high temperature insulation composite material.

[0042] As used herein, the term "high temperature event" is intended to describe circumstances where temperatures are reached sufficient to partially or completely volatilize the fibrillated polymer matrix within the high temperature insulation composite.

[0043] The thermal insulation composite (1) provides thermal conductivity prior to exposure to a high temperature event and (2) acts as a protective heat transmission barrier when subjected to a high temperature event (wherein the temperature is sufficient to partially or completely volatilize the fibrillated polymer binder within the thermal insulation composite). It should be understood that the phrases "fibrillated polymer matrix" and "fibrillated polymer binder" are used interchangeably herein.

[0044] The thermal insulation composite material is suitable for applications and / or articles having at least one heat-sensitive component, wherein the heat-sensitive component is capable of releasing energy (usually upon failure of the component) sufficient to generate a temperature at which the fibrillated polymer matrix within the thermal insulation composite material partially or completely volatilizes (e.g., degrades), but the thermal insulation composite material still provides sufficient thermal insulation to protect one or more adjacent heat-sensitive components from damage. This is particularly important in applications / articles where the temperature of a first high-temperature thermal event (usually associated with a failure of a component) can damage an adjacent heat-sensitive component, which in turn can generate a second high-temperature thermal event, and so on (e.g., the propagation of a runaway high-temperature thermal event in a high-energy battery). The thermal insulation composite material protectively delays or prevents the propagation of heat energy from a first side of the thermal insulation composite layer to a second, opposite side of the thermal insulation composite layer, so that one or more heat-sensitive components on the second, opposite side of the thermal insulation composite material are fully protected from the effects of the high-temperature thermal event, so that the adjacent heat-sensitive components do not enter a thermal runaway event or the thermal runaway propagation rate is reduced.

[0045] In certain applications, such as in certain high-energy batteries, high-temperature thermal events may occur. As described above, high-temperature thermal events may be sufficient to damage adjacent heat-sensitive components, and include situations where adjacent heat-sensitive components are exposed to high-temperature events that may trigger secondary high-temperature events in adjacent heat-sensitive components (such as runaway events in faulty lithium-ion batteries). Therefore, there is a need for a thermal barrier that protects adjacent heat-sensitive components from being exposed to high temperatures (destructive temperatures). As shown in the test described herein, one side ("challenge side") of a thin sheet of heat-insulating composite material (about 1 mm thick) is compressed into contact with a stainless steel block heated to about 800°C (i.e., a temperature sufficient to volatilize the fibrillated polymer). The maximum temperature of the opposite side of the sheet ("protection side") is significantly lower. In one embodiment, the heat-insulating composite materials that can act as a heat-transfer barrier are those that, when the challenge side is exposed to a temperature of about 800°C in accordance with the protective heat-transfer barrier test described below, can limit the maximum temperature of the protection side to 215°C or lower.

[0046] Depending on the choice of fibrillating polymer, the temperature required to partially or completely volatilize the fibrillated polymer binder in the thermal insulating composite material varies. Thus, the thermal insulating composite materials are those that, when subjected to a temperature that at least partially volatilizes the fibrillated polymer matrix (i.e., the challenge side), can provide a reduction in the maximum observed temperature (i.e., the protected / insulating side) by at least about 70%, at least about 73%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, or at least about 95% (where 100% is the maximum or the total % is equal to 100%). In another embodiment, the challenge side temperature includes thermal energy sufficient to completely volatilize the fibrillated polymer matrix.

[0047] In another embodiment, the high temperature event comprises a temperature that partially or completely volatilizes the fibrillated polymer matrix in the thermal insulation composite, the temperature being at least about 250°C, at least about 300°C, at least about 350°C, at least about 400°C, at least about 450°C, at least about 500°C, at least about 550°C, at least about 600°C, at least about 650°C, at least about 700°C, at least about 750°C, at least about 800°C, or at least about 850°C, wherein the thermal insulation composite has a The maximum temperature on the opposite side does not exceed about 225° C., does not exceed about 220° C., does not exceed about 215° C., does not exceed about 210° C., does not exceed about 205° C., does not exceed about 200° C., does not exceed about 195° C., does not exceed about 190° C., does not exceed about 185° C., does not exceed about 180° C., does not exceed about 175° C., does not exceed about 170° C., does not exceed about 165° C., does not exceed about 160° C., does not exceed about 155° C., does not exceed about 150° C., or does not exceed about 145° C. In at least one embodiment, the high temperature thermal event on the challenge side of the insulation composite is at least 800° C., while the maximum temperature on the opposite side (protected / insulating side) of the insulation composite is 215° C. or less.

[0048] Thermal insulation composite materials

[0049] The insulating composite materials described herein include a fibrillated polymer matrix, insulating particles, and additional particulate components (e.g., one or more sunscreens, reinforcing fibers, expandable microspheres, and combinations thereof). In one embodiment, the insulating composite material includes greater than 1% by weight of the combined total amount of the additional particulate components, including one or more sunscreens, reinforcing fibers, expandable microspheres, and combinations thereof. As described above, unless otherwise defined, the term weight percent (wt%) refers to the percentage relative to the total weight of the insulating composite material. In another embodiment, the insulating composite material includes greater than 1% by weight of (one or more) sunscreens.

[0050] The insulating particles and additional particle components (i.e., one or more sunscreens and / or reinforcing fibers and / or expandable microspheres) are permanently embedded within the fibrillated polymer matrix. As used herein, the phrase "permanently embedded" is intended to describe that the insulating particles and additional particle components of the insulating composite material are non-covalently fixed within the fibrillated polymer matrix. There is no separate adhesive to fix or otherwise bond the insulating particles and additional particle components within the fibrillated polymer matrix. Furthermore, it should be understood that in some embodiments, the insulating particles and additional particle components are located throughout the thickness of the fibrillated polymer matrix of the insulating composite material.

[0051] The insulating composite material, due at least to the strength of the fibrillated polymer matrix, can be formed into thin, flexible, compressible, and conformable shapes, thereby facilitating the ability to manufacture shaped materials suitable for target applications.

[0052] Thermal insulation particles

[0053] The term "thermal insulation particles" refers to silica-based thermal insulation particles, which include at least one of the following: fumed silica, amorphous silica, colloidal silica, precipitated silica, fused silica, silica gel (excluding any silica aerogel), silica xerogel, silicate (e.g., calcium silicate), fumed metal oxides (e.g., fumed alumina, fumed titania, fumed blends of silica / alumina / titania), and combinations thereof. In one embodiment, the thermal insulation particles may be modified to include functional groups to change the relative hydrophilicity / hydrophobicity of the particles (e.g., fumed hydrophobic silica). In another embodiment, the "thermal insulation particles" are composed of fumed silica particles, amorphous silica particles, hydrophobic silica particles, precipitated silica particles, fused silica particles, silica gel particles (excluding silica aerogel), silicate particles (e.g., calcium silicate particles), and any combination thereof. In yet another embodiment, the "thermal insulation particles" may be composed solely of fumed silica particles.

[0054] The silica-based insulating particles may be present in the insulating composite in an amount of at least 1 weight percent (based on the total weight of the insulating particles), at least 2 weight percent, at least 3 weight percent, at least 4 weight percent, at least 5 weight percent, at least 6 weight percent, at least 7 weight percent, at least 8 weight percent, at least 9 weight percent, at least 10 weight percent, at least 20 weight percent, at least 30 weight percent, at least 40 weight percent, at least 50 weight percent, at least 60 weight percent, at least 70 weight percent, at least 80 weight percent, at least 90 weight percent, at least 95 weight percent, or at least 99 weight percent. In some embodiments, the amount of silica-based insulating particles present in the insulating composite material may be from about 1% to about 100% by weight, from about 5% to about 100% by weight, from about 10% to about 100% by weight, from about 20% to about 100% by weight, from about 30% to about 100% by weight, from about 40% to about 100% by weight, from about 50% to about 100% by weight, from about 60% to about 100% by weight, from about 70% to about 100% by weight, from about 80% to about 100% by weight, or from about 90% to about 100% by weight. In other embodiments, the amount of silica-based insulating particles present in the insulating composite material may be from about 40% to about 99% by weight, from about 40% to about 95% by weight, from about 50% to about 95% by weight, from about 60% to about 95% by weight, from about 70% to about 95% by weight, from about 80% to about 95% by weight, or from about 90% to about 95% by weight. In other embodiments, the insulating particles can be present in the insulating composite material in an amount of about 1% to about 80% by weight, about 2% to about 80% by weight, about 3% to about 80% by weight, about 4% to about 80% by weight, about 5% to about 80% by weight, about 6% to about 80% by weight, about 7% to about 80% by weight, about 8% to about 80% by weight, about 9% to about 80% by weight, about 10% to about 80% by weight, about 20% to about 80% by weight, about 30% to about 80% by weight, about 40% to about 80% by weight, about 50% to about 80% by weight, about 60% to about 80% by weight, or about 70% to about 80% by weight. In some embodiments, the silica-based insulating particles can be present only in the insulating particles. The silica-based insulating particles can be fumed silica or include fumed silica.

[0055] sunscreen

[0056] In one embodiment, the thermal insulation composite material includes at least one sunscreen, and the sunscreen may be present in the thermal insulation composite material outside the additional thermal insulation particles. Sunscreen reduces radiant heat transfer and improves thermal performance. Non-limiting examples of suitable sunscreens for thermal insulation composite materials include, but are not limited to: carbon black, titanium dioxide, iron oxide, silicon carbide, molybdenum silicide, manganese oxide, polydialkylsiloxanes with alkyl groups containing 1 to 4 carbon atoms, or any combination thereof. In one embodiment, the sunscreen can be used in the form of a finely dispersed powder. In at least one embodiment, the amount of sunscreen present in the thermal insulation composite material (based on the total weight of the thermal insulation composite material) may be up to about 60 weight %. In some embodiments, the amount of sunscreen present in the thermal insulation composite material (based on the total weight of the thermal insulation composite material) is greater than about 1 weight %.

[0057] In some embodiments, the amount of sunscreen present in the insulating composite (based on the total weight of the insulating composite) is greater than about 10 weight %. In some embodiments, the amount of sunscreen present in the high temperature insulating composite can be about 1 weight % to about 60 weight % (based on the total weight of the insulating composite), about 3 weight % to about 60 weight %, about 5 weight % to about 60 weight %, about 7 weight % to about 60 weight %, about 10 weight % to about 60 weight %, about 15 weight % to about 60 weight %, about 20 weight % to about 60 weight %, about 25 weight % to about 60 weight %, about 30 weight % to about 60 weight %, about 35 weight % to about 60 weight %, about 40 weight % to about 60 weight %, about 45 weight % to about 60 weight %, or about 50 weight % to about 60 weight %. In some embodiments, the amount of the opacifier present in the insulating composite material can be from about 1% to about 45% by weight (based on the total weight of the insulating composite material), from about 3% to about 45% by weight, from about 5% to about 45% by weight, from about 10% to about 45% by weight, from about 15% to about 45% by weight, from about 15% to about 30% by weight, or from about 15% to about 25% by weight. In some embodiments, the amount of the opacifier present in the insulating composite material can be less than about 10% by weight, from about 1% to about 10% by weight, from about 2% to about 10% by weight, from about 3% to about 10% by weight, from about 4% to about 10% by weight, from about 5% to about 10% by weight, from about 6% to about 10% by weight, from about 7% to about 10% by weight, from about 8% to about 10% by weight, or from about 9% to about 10% by weight.

[0058] Reinforcement fiber

[0059] In some embodiments, the thermal insulation composite material further comprises at least one reinforcing fiber. In one embodiment, the reinforcing fiber can be a chopped fiber having a size of about 0.1 mm to about 25 mm, about 0.1 to about 19 mm, about 0.1 mm to about 15 mm, about 0.1 mm to about 13 mm, about 0.1 mm to about 10 mm, about 0.1 mm to about 7 mm, or about 0.1 mm to about 5 mm. A variety of reinforcing fibers can be used, and can include, for example, but not limited to, fibers of carbon fiber, glass fiber, aluminoborosilicate fiber, or a combination thereof. In at least one embodiment, the reinforcing fiber is chopped glass fiber. The amount of reinforcing fiber present in the high-temperature thermal insulation composite material is at most about 25 weight %. In some embodiments, the amount of reinforcing fiber present in the thermal insulation composite material is about 1 weight % to about 25 weight %, about 2 weight % to about 20 weight %, about 3 weight % to about 20 weight %, about 5 weight % to about 15 weight %, about 8 weight % to about 15 weight %, about 9 weight % to about 15 weight %, or about 10 weight % to about 15 weight %. In some embodiments, the reinforcing fibers are present in an amount from about 1 wt % to about 10 wt %, from about 2 wt % to about 10 wt %, from about 3 wt % to about 10 wt %, from about 4 wt % to about 10 wt %, from about 5 wt % to about 10 wt %, from about 6 wt % to about 10 wt %, from about 7 wt % to about 10 wt %, or from about 8 wt % to about 10 wt %.

[0060] Expandable microspheres

[0061] The insulating composite material may also include one or more expandable microspheres (e.g., Available from Nouryon Chemicals Ltd., The Netherlands. In one embodiment, the thermal insulation composite includes up to about 20% by weight of an expandable polymer microsphere, such as Expandable microspheres can generally be described as expandable thermoplastic microspheres that encapsulate an expandable gas. In some embodiments, the insulating composite comprises expandable microspheres in an amount of about 1 wt % to about 20 wt %, about 1 wt % to about 15 wt %, or about 1 wt % to about 10 wt %. In some embodiments, the expandable microspheres are present in the insulating composite in an amount of about 1 wt % to about 15 wt %, about 1 wt % to about 14 wt %, about 1 wt % to about 13 wt %, about 1 wt % to about 12 wt %, about 1 wt % to about 11 wt %, about 1 wt % to about 10 wt %, about 1 wt % to about 9 wt %, about 1 wt % to about 8 wt %, about 1 wt % to about 7 wt %, about 1 wt % to about 6 wt %, about 1 wt % to about 5 wt %, or about 1 wt % to about 3 wt %.

[0062] In some embodiments, the expandable microspheres are present in the insulating composite in an amount from about 0.1% to about 10% by weight, from about 0.1% to about 9% by weight, from about 0.1% to about 8% by weight, from about 0.1% to about 7% by weight, from about 0.1% to about 6% by weight, from about 0.1% to about 5% by weight, from about 0.1% to about 5% by weight, from about 0.1% to about 4% by weight, from about 0.1% to about 3% by weight, from about 0.1% to about 2% by weight, from about 0.1% to about 1% by weight, from about 0.5% to about 5% by weight, from about 0.5% to about 4% by weight, from about 0.5% to about 3% by weight, from about 0.5% to about 2% by weight, or from about 0.5% to about 1% by weight.

[0063] The use of expandable microspheres can reduce the density of the resulting thermal insulation composite and the product comprising the thermal insulation composite. In one embodiment, the density of the thermal insulation composite is in the range of about 0.01 g / cm 3 to about 0.40g / cm 3 , about 0.01g / cm 3 to about 0.30g / cm 3 , about 0.01g / cm 3 to about 0.25g / cm 3 , or about 0.05g / cm 3 to about 0.25g / cm 3 . Additionally, the insulating composite is compressible, meaning that its overall thickness can be reduced by applying pressure to the insulating composite. Embodiments of the insulating composite comprising expandable microspheres exhibit improved compressibility at low to moderate compressive stress values ​​while maintaining compressive stiffness as the compressive stress rises to higher values. The compressibility of the insulating composite can be adjusted by varying the number of expandable microspheres. Additionally, the compressible insulating composite helps accommodate gaps or voids that arise from individual dimensions when placed in a container or volume of a fixed, specific size (e.g., a battery cell). The insulating composite can also maintain a desired compressive stress or torque on a single cell as the cell changes dimensions due to temperature fluctuations and charge-discharge cycling.

[0064] Additional components

[0065] The insulating composite may also include one or more additional components such as, but not limited to, flame retardants, additional polymers, opacifiers (as described above), intumescent materials, oxygen scavengers, dyes, plasticizers, and thickeners.

[0066] like Figure 1AAs shown, the insulating particles, sunscreen, reinforcing fibers, expandable microspheres and / or additional components (hereinafter collectively referred to as "particulate components

[230] ") are permanently embedded in the microstructure of the fibrillated polymer matrix of the thermal insulation composite material. As described above, the phrase "permanently embedded" is intended to mean that the insulating particles and additional particulate components (e.g., insulating particles, reinforcing fibers, expandable microspheres and sunscreen) of the high temperature thermal insulation composite material are non-covalently fixed within the fibrillated polymer matrix. There is no separate binder to fix the particulate components within the fibrillated polymer matrix. In addition, it should be understood that the insulating particles and additional particulate components are located throughout the thickness of the fibrillated polymer matrix. The insulating particles and additional particulate components

[230] are approximately uniformly distributed throughout the microstructure of the fibrillated polymer film of the thermal insulation composite material

[200] . The thermal insulation composite material

[200] has a challenge side

[210] , a protection side

[220] , a height (H) and a length (L).

[0067] Thermal insulation composites can be made from Figure 1A The composite material (e.g., a single layer) is generally shown, or optionally formed from a plurality of layers such as Figure 1B Generally, a multilayer stacked composite material (e.g., multiple single-layer insulation composite materials) is formed. In the multilayer stacked insulation composite material, each layer can have insulation particles and / or additional particle components having different chemical compositions, different particle sizes, different particle size distributions, or different particle distributions. In one embodiment, an opacifier having different properties (e.g., composition, size, and / or shape) can be distributed throughout the thickness of the insulation composite material, as described in Hu et al. [Radiative Characteristics of Opacifier-Loaded Silica Aerogel Composites, 2013].

[0068] like Figure 1B As shown, in the multi-layer stacked thermal insulation composite material, for the sake of convenience of explanation, only the sunscreen among the additional particle components in the multi-layer stacked thermal insulation composite material is shown. Figure 1B 1 is a schematic cross-sectional view of an embodiment of a multi-layer stacked thermal insulation composite material having multiple layers. As shown in the figure, the multi-layer stacked thermal insulation composite material

[240] has a height (H) and a length (L). The multi-layer stacked thermal insulation composite material

[240] includes a challenge side

[250] and a protection side

[260] .

[0069] In such Figure 1BIn the embodiment shown, the height (H) is divided into three layers, namely layer A

[270] , layer B

[280] , and layer C

[290] . In some embodiments, layer A

[270] , layer B

[280] , and layer C

[290] may contain the same type of sunscreen but with different size distributions. In other embodiments, layer A

[270] , layer B

[280] , and layer C

[290] may contain different types of sunscreen and with different size distributions. Figure 1B As shown, layer A

[270] contains a first opacifier

[300] having a first size distribution, layer B

[280] contains a first opacifier

[300] having a second size distribution, and layer C

[290] contains a second opacifier

[310] having a first size distribution. The first opacifier

[300] may be silicon carbide and the second opacifier

[310] may be carbon black, but this is exemplary in nature and is not intended to limit the scope of the present disclosure. In some embodiments, the additional particulate component may be different in each layer, or only in certain layers. In other embodiments, the particulate component in each layer is the same, but the size distribution of each layer is different. Thus, each layer in a multi-layer stacked thermal insulation composite material may include thermal insulation particles and / or one or more additional particulate components, wherein the additional particulate components have different chemical compositions, different particle sizes, and / or different particle size distributions within each layer (or only within certain layers).

[0070] In forming the multilayer stacked insulating composite, each layer is formed separately as described below and then layered or stacked together in a manner that achieves the desired orientation of each layer in the multilayer stacked insulating composite. The layers can be bonded to each other in any conventional manner (e.g., lamination, bonding, or other bonding means) to form the multilayer insulating composite.

[0071] Fibrillated polymer matrix

[0072] The use of fibrillable polymers to prepare thermal insulation composites can form thin and flexible shapes (such as films, sheets and tubes), in which the thermal insulation particles and other additional particle components are permanently embedded (such as non-covalently bound; there is little or no dust) and distributed in the fibrillated polymer matrix. It should be understood that there is no absorption step to introduce the thermal insulation particles and additional particle components into the fibrillated polymer matrix. Therefore, the thermal insulation particles and additional particle components in the high-temperature thermal insulation composite are permanently embedded in the fibrillated polymer matrix. For many applications where high temperature events may occur (such as capacitors, heating elements, high-energy batteries, etc.), a thin and flexible shape is very important. Even if the fibrillated polymer matrix in the thermal insulation composite is completely volatilized, the remaining components can still provide a separate matrix to provide protection. This is at least due to the better thermal stability of the additional particle components relative to the fibrillated polymer matrix. In at least one embodiment, the thickness of the thermal insulation composite is about 5 mm or less, about 4 mm or less, about 3 mm or less, about 2 mm or less, or about 1 mm or less. In some embodiments, the insulating composite has a thickness of about 1 mm to about 5 mm, about 1 mm to about 4 mm, about 1 mm to about 3 mm, about 1 mm to about 2 mm, about 0.01 mm to about 5 mm, about 0.01 mm to about 4 mm, about 0.1 mm to about 3 mm, about 0.1 mm to about 2.5 mm, about 0.1 mm to about 2 mm, about 0.1 mm to about 1.5 mm, or about 0.1 mm to about 1 mm. In other embodiments, the insulating composite has a thickness of less than or equal to 1 mm.

[0073] As used herein, the terms "fibrillation" and "fibrillable" refer to the ability of a polymer to form a microstructure of nodes and fibrils, or a microstructure consisting essentially of only fibrils, when subjected to sufficient shear forces. In some embodiments, the fibrillated polymers can be mixed, for example, by wet mixing, dispersion, or coagulation. The time and temperature at which shearing and / or mixing occurs varies with particle size, the materials used, and the amount of particles mixed, and can be readily determined by one skilled in the art.

[0074] Thermal insulation composites can be obtained with a variety of fibrillated polymers. Using fibrillated polymers as binders for thermal insulation composites can provide strength (and the ability to form thin materials), conformability, and compressibility, while also allowing the particle components to be durably embedded in a cohesive shape. It should be noted that the thermal insulation particles and additional particle components (expandable microspheres, sunscreens, and reinforcing fibers) are considered herein as "particle components." In the blending / molding process, the fibrillated polymer particles and particle components in the thermal insulation composite are blended with sufficient shear forces to produce a fibrillated polymer matrix (a microstructure consisting of nodes interconnected by fibrils or essentially only fibrils), and the particle material is durably embedded therein.

[0075] The decomposition temperature of the fibrillated polymer matrix varies depending on the polymer. In one aspect, the fibrillated polymer matrix is ​​prepared from fibrillated polymer particles of polyolefins, fluoropolymers, polyurethanes, polyesters, polyamides, polylactic acid, or any combination thereof. Non-limiting examples of fibrillated polymers include, but are not limited to, polytetrafluoroethylene (PTFE) (U.S. Patent No. 3,315,020 to Gore; U.S. Patent No. 3,953,566 to Gore; U.S. Patent No. 7,083,225 to Baille), expanded polytetrafluoroethylene (ePTFE), ultra-high molecular weight polyethylene (UHMWPE) (U.S. Patent No. 10,577,468 to Sbriglia), polylactic acid (PLLA; U.S. Patent No. 9,732,184 to Sbriglia), vinylidene fluoride and tetrafluoroethylene or trifluoroethylene. Copolymers (e.g., VDF-co-(TFE or TrFE) polymers; U.S. Pat. No. 10,266,670 to Sbriglia), poly(ethylene tetrafluoroethylene) (ETFE; U.S. Pat. No. 9,932,429 to Sbriglia), parylene (PPX; U.S. Pat. No. 2016 / 0032069 to Sbriglia), and polytetrafluoroethylene (PTFE; U.S. Pat. No. 3,315,020 to Gore; U.S. Pat. No. 3,953,566 to Gore; U.S. Pat. No. 7,083,225 to Baille). In one embodiment, the fibrillated polymer is a fibrillated PTFE made from fine powder particles of PTFE that is not melt processible (i.e., the melt flow viscosity is too high for melt extrusion and high shear blending and / or paste processing is required to form the fibrillated polymer matrix) (see, e.g., Expanded PTFE Applications Handbook - Technology, Manufacturing and Applications, Ebnesajjad, Sina (1997), Elsevier, Cambridge, MA).

[0076] As used herein, the term "PTFE" includes homopolymeric PTFE and modified PTFE resins (e.g., having up to 5 weight percent, up to 4 weight percent, up to 3 weight percent, up to 2 weight percent, or up to 1 weight percent of one or more olefinic comonomers, including but not limited to perfluoroalkylethylenes (e.g., perfluorobutylethylene; U.S. Pat. No. 7,083,225 to Baille), hexafluoropropylene, perfluoroalkyl vinyl ethers (C1-C8 alkyl; e.g., perfluoromethyl vinyl ether, perfluoroethyl vinyl ether, perfluoropropyl vinyl ether, perfluorooctyl vinyl ether, etc.). PTFE is also intended to include expanded modified PTFE and expanded copolymers of PTFE, such as those described in U.S. Pat. No. 5,708,044 to Branca, U.S. Pat. No. 6,541,589 to Baillie, U.S. Pat. No. 7,531,611 to Sabol et al., U.S. Pat. No. 8,637,144 to Ford, and U.S. Pat. No. 9,139,669 to Xu et al.

[0077] Suitable fibrillating fluoropolymers may also include fibrillable copolymers and terpolymers of tetrafluoroethylene (TFE) with comonomers such as vinylidene fluoride (VDF), vinylidene fluoride, hexafluoroisobutylene (HFIB), trifluoroethylene (TrFE), chlorotrifluoroethylene (CTFE), hexafluoropropylene (HFP), fluorodioxolanes or fluorodioxolanes (e.g., U.S. Pat. No. 9,040,646 to Ford), and ethylene (e.g., ethylene tetrafluoroethylene (ETFE; U.S. Pat. No. 9,932,429; supra). All of the above polymers will at least partially or completely volatilize (degrade) upon exposure to high temperature events of temperatures of at least 800°C.

[0078] In some embodiments, the fibrillable polymer matrix is ​​a polytetrafluoroethylene (PTFE) matrix having a microstructure of nodes and fibrils or a microstructure consisting essentially of only fibrils. The fibrils of the PTFE particles interconnect with other PTFE fibrils and / or nodes, forming a network within and around the particle components, effectively securing them and durably embedding them in the fibrillated polymer matrix.

[0079] The fibrillated polymer is present in the insulating composite in an amount of about 60 wt % or less, about 50 wt % or less, about 40 wt % or less, about 30 wt % or less, about 20 wt % or less, or about 10 wt % or less. The fibrillated polymer is present in the insulating composite in an amount of about 1 wt % to about 60 wt %, about 1 wt % to about 50 wt %, about 1 wt % to about 40 wt %.

[0080] %, about 1 wt % to about 30 wt %, about 1 wt % to about 25 wt %, about 1 wt % to about 20 wt %, about 1 wt % to about 15 wt %, about 1 wt % to about 15 wt %, or about 1 wt % to about 10 wt %. In other embodiments, the amount of the fibrillated polymer is in the range of about 5 wt % to about 30 wt %, about 10 wt % to about 25 wt %, about 1 wt % to about 20 wt %, about 1 wt % to about 15 wt %, about 1 wt % to about 10 wt %, or about 1 wt % to about 5 wt %.

[0081] In some embodiments, the porous fibrillated polymer matrix can be prepared by dry mixing fibrillable polymer particles with other particulate components, in a manner generally as taught in U.S. Publication No. 2010 / 0119699 to Zhong et al., U.S. Pat. No. 7,118,801 to Ristic-Lehmann et al., U.S. Pat. No. 5,849,235 to Sassa et al., U.S. Pat. No. 6,218,000 to Rudolf et al., or U.S. Pat. No. 4,985,296 to Mortimer, Jr.

[0082] In one embodiment, the coagulant is prepared using the general method described in U.S. Patent No. 7,118,801 to Ristic-Lehmann et al. The general method for preparing the coagulant includes mixing an aqueous dispersion of the particulate component particles (insulating particles, sunscreen, reinforcing fibers and / or expandable microspheres) with a dispersion of fibrillable polymer particles and then coagulating the mixture by stirring or by adding a coagulant. In the presence of the insulating particles and the other particulate components, the co-coagulation of the polymer particles forms an intimate blend of the fibrillable polymer particles, the insulating particles and the other particulate components (i.e., the insulating material). The insulating material is drained and dried in a convection oven at about 433K. Depending on the type of wetting agent used, the dried insulating material can be in the form of a loosely bound powder or in the form of a soft cake, which can then be cooled and ground to obtain the insulating material in powder form. The powdered insulating material can then be mixed with a suitable hydrocarbon lubricant (e.g., an isoparaffin lubricant (e.g., The thermal insulation composite material is obtained by mixing a plurality of thermally insulating materials, such as a thermally insulating composite material and a thermally insulating composite material, and then performing a subsequent mechanical processing step to induce fibrillation of the bonding matrix and form it into a desired shape (e.g., a tape, sheet, or putty). The mechanical processing step may include one or more of the following steps: high shear mixing, pressing, calendaring, and combinations thereof to form a thermally insulating composite material having a fibrillated polymer matrix. At least one drying step is included to remove the alkane lubricant.

[0083] The insulating composite material can be formed into a relatively thin profile (e.g., a sheet). The thin profile of the high-temperature insulating composite material is attractive for use in electronic devices and / or batteries where undesirable high-temperature thermal events may occur. In one embodiment, the insulating composite material is formed into a shaped putty, tube, strip, or sheet having an average thickness (or wall thickness in the case of a tube) of less than about 5 mm, about 4 mm or less, about 3 mm or less, about 2 mm or less, or about 1 mm or less.

[0084] Thermal insulation products including thermal insulation composites

[0085] In one embodiment, a thermal insulation product includes a first component capable of generating a high temperature event (i.e., a first temperature), a second component to be protected from exposure to the first temperature caused by the high temperature event, and a thermal insulation composite material. The thermal insulation component is located between the first component and the second component. The thermal insulation component can be in the form of a tube, a sheet, or a film. The first side of the thermal insulation composite material can face the first component, and the second side of the thermal insulation composite material can face the second component. In some embodiments, the thermal conductivity of the thermal insulation composite material under atmospheric conditions (298.15K, 101.3kPa) does not exceed 25 milliwatts per meter Kelvin (Mw / mK).

[0086] The thermal insulation product may also include one or more support materials in the form of support layers on one or more sides of the thermal insulation composite material. In one embodiment, the support layer is a polymer layer, a woven layer, a braided layer, a non-woven layer or any combination thereof. The polymer layer can be a non-porous layer, a porous layer, a microporous layer and a combination thereof. Non-limiting additional support layers include fluoropolymer films (such as polytetrafluoroethylene films), expanded fluoropolymer films (such as expanded polytetrafluoroethylene films), polyolefin films (such as polyethylene films), metal films, electrical insulating layers, adhesive layers or any combination thereof. The support layer can be included in the thermal insulation product by laminating, adhering or otherwise bonding one or more support layers to the high temperature thermal insulation composite material. For example, the thermal insulation composite material can be a sheet or film form having a first side and a second side, wherein the thickness is less than the width and / or length direction. One or more support layers can be adhered or otherwise bonded or fixed to the first side, the second side, or both the first side and the second side of the thermal insulation composite material.

[0087] One or more support layers may be adhered or otherwise bonded or secured to the thermal insulation composite material using adhesion, welding, calendering, coating, or any combination thereof. In some embodiments, the thermal insulation article may comprise multiple layers. For example, the thermal insulation composite material may be bonded with a layer of expanded PTFE on one or both sides to produce a thermal insulation composite material having a double or triple layer structure. One or more textile layers, such as woven fabrics, textiles, nonwovens, or any combination thereof, may be adhered or otherwise bonded or secured to the thermal insulation composite material. For example, as is known in the art, the adhesive may be applied to the thermal insulation composite material, the textile, or both the thermal insulation composite material and the textile in a continuous or discontinuous manner.

[0088] The textile layer can be a woven, textile, nonwoven, or any combination thereof. In some embodiments, the woven, textile, or nonwoven can be a flame retardant woven, flame retardant textile, or flame retardant nonwoven. Suitable textile layers are well known in the art and can include elastic and non-elastic textiles, such as Polyurethane, polyester, polyamide, acrylic, cotton, wool, silk, linen, rayon, flax, jute; flame retardant textiles, e.g. Aramid (available from DuPont de Nemours and Company, Wilmington, Delaware), aramid, flame retardant cotton, polybenzimidazole, poly(p-phenylene-2,6-benzobisoxazole), flame retardant rayon, modacrylic, modacrylic blend, polyamine, carbon, glass fiber, or any combination thereof.

[0089] lithium-ion batteries

[0090] In some embodiments, the thermal insulation composite is used as a thermal insulation and protective barrier layer in a high energy battery (e.g., a multi-core lithium ion battery). In one aspect, the thermal insulation and protective barrier is used to at least partially or completely surround or separate one or more cells in the battery or the battery itself. In another embodiment, the battery cell is completely surrounded by the thermal insulation composite. The thermal insulation composite can also be used to insulate modules or battery packs to prevent the spread of heat energy or to prevent the harmful effects of the spread that may occur when the heat energy spreads to the other side of the insulation component.

[0091] Other embodiments in which the thermal insulation composite material may be utilized include, but are not limited to, lithium batteries for electrification of aircraft and drones, lithium batteries for residential energy storage (e.g., solar or wind energy storage), lithium batteries for energy backup systems for buildings and critical infrastructure, batteries for computer power backup systems or uninterruptible power systems (UPS), batteries for electric boats, drones and unmanned aerial vehicles (UAVs), batteries for personal vehicles (e.g., motorcycles), and batteries for emergency medical backup systems.

[0092] The disclosure of the present application has been generally described above and in conjunction with specific embodiments. It will be apparent to those skilled in the art that various modifications and variations may be made to the present disclosure without departing from the spirit or scope of the present disclosure as defined in the appended claims.

[0093] Test Method

[0094] Density measurement

[0095] The density of the insulation composite was calculated using the formula density = mass / volume. The mass of a 1.5-inch diameter punch was measured using a Sartorius Entris 224-1S analytical balance. The sample thickness was measured using a Mitutoyo Litematic VI-50 contact thickness gauge, with the sample placed between two glass slides of known thickness and a probe force of 0.2 N. Three samples were tested, recorded, and then averaged to provide the average density.

[0096] tensile strength

[0097] A flat-faced grip and a 0.445 kN load cell were used. The tensile strength of the films was measured using a 5565 tensile tester. The gauge length was 6.35 cm and the crosshead speed was 50.8 cm / min (strain rate = 13.3% / sec). To ensure comparable results, the laboratory temperature was maintained between 68°F (20°C) and 72°F (22.2°C). If the sample broke at the grip interface, the data was discarded.

[0098] For longitudinal (lengthwise) tensile strength measurements, the larger dimension of the sample is oriented in the machine direction, or "downweb" direction. For transverse tensile strength measurements, the larger dimension of the sample is oriented perpendicular to the machine direction, also known as the "crossweb" direction. The thickness of the sample is then measured using a Mitutoyo 547-400 Absolute caliper. Each sample is then tested separately on the tensile tester. Three different sections are measured for each sample. The average of the three maximum load (i.e., peak force) measurements is used.

[0099] Calculate longitudinal and transverse tensile strength using the following formulas:

[0100] Tensile strength = maximum load / cross-sectional area

[0101] The average of three cross-web tests was recorded as the longitudinal and transverse tensile strength.

[0102] thickness

[0103] The sample thickness was measured using the integrated thickness measurement function of a thermal conductivity meter (Laser Comp, Inc., Saugus, MA, Fox 314 model). Single measurements were recorded.

[0104] Room temperature thermal conductivity

[0105] Thermal conductivity was also measured without compressing the sample. The samples were measured using a Laser Comp Fox 314 thermal conductivity analyzer (Laser Comp, Saugus, MA). Single measurements were recorded. Two 8" x 8" (20.3 cm x 20.3 cm) samples were stacked and measured at a 20-degree temperature difference (hot plate 35°C, cold plate 15°C).

[0106] Compression set test

[0107] Compressive stress-strain properties and compression set properties were determined using ASTM D395-18, except that the sample thickness was 1 mm and the diameter was 3.08 cm (i.e., an Instron 5565 test frame using a 1 kN load cell; an upper platen with a 5.08 cm diameter; a lower platen with a 12.7 cm diameter self-aligning spherical seat; an LVDT deflection sensor fixed to the upper platen and in contact with the lower platen; and a thermal insulation composite material with a 3.08 cm diameter). Compression set properties were measured at 50% compressive displacement, held for 30 minutes, and calculated using the following formula:

[0108]

[0109] Where t0 refers to the original thickness, t i The final thickness is then measured using a Mitutoyo Litematic VI-50 contact thickness gauge. The sample is sandwiched between glass sheets and then brought into contact with the probe at a force of 0.2 N. After the 0.2 N contact, the probe is allowed to equilibrate for 30 seconds.

[0110] For compressive stress-strain properties, compression was initiated at a displacement rate of 0.5 mm / min until a displacement of 50% of the measured thickness was reached. Once 50% of the original thickness was reached, the plate's displacement was held constant for a period ranging from 30 minutes to 24 hours, after which the plate was released. Figure 4 shows a plot of compressive engineering stress versus thickness-normalized compressive deflection.

[0111]

[0112] where x irefers to the compressive displacement, and t0 refers to the original thickness of samples 1-4 of Example 2. This demonstrates that the compressive properties of the thermal insulation composite can be tuned to achieve a wide range of compressive deflections under a fixed compressive stress.

[0113] Protective heat transmission barrier test

[0114] The following test is used to measure the thermal barrier properties of an insulating composite when exposed to a heated substance at a temperature sufficient to partially or completely volatilize (e.g., degrade) the fibrillated polymer within the insulating composite. A thin sheet (~1 mm) of the insulating composite is placed in compression contact with a stainless steel block ("heat accumulator") at ~800°C having the following dimensions: height 5.5 inches (about 14.0 cm); width 3.5 inches (about 7.6 cm); thickness 0.5 inches (about 1.27 cm). The density of the composite is 7999.4 kg / m 3 , the volumetric heat capacity is 617.6 J / kgK, and the calculated sensible energy is 600 kJ. The side of the test material in contact with the heated substance is referred to herein as the "challenge side". Over a period of 10 to 60 minutes, the maximum temperature observed on the opposite side of the test material (also referred to herein as the "protection side") after contact is recorded. Thin sheets of thermal insulation composite materials (~1 mm thick) that can limit the maximum observed temperature to 215°C or less are considered suitable for use as thermal insulation composites.

[0115] One side (the "challenge side") of a rectangular sheet (~1 mm thick) of the test material was placed in contact under pressure with a rectangular stainless steel block (referred to herein as the "regenerator") heated to a target temperature of approximately 800°C. Two identical samples were placed on opposite sides of the rectangular regenerator to ensure symmetric heat dissipation. A K-type thermocouple was used to measure the temperature of the regenerator and the temperature on the opposite side of each test sample. After contact with the regenerator, the average temperature on the opposite side of each test sample was continuously recorded for a period of time (10 to 60 minutes), and the highest average temperature observed during the contact period was recorded.

[0116] refer to Figure 2 and Figure 3 ( Figure 3(side view of the components in the contact compression zone

[113] during the test test) showing that the test system

[100] consists of a high temperature furnace

[101] configured with an opening

[102] for accommodating a rectangular 304 stainless steel block ("regenerator")

[103] measuring 5.5 inches x 3.5 inches (approximately 14.0 cm x 7.6 cm x 0.95 cm). The total mass of the regenerator is 905 g. The regenerator is heated in the furnace

[101] to a temperature of approximately 800°C. The volume, material properties, volumetric heat capacity, and thermal conductivity of the regenerator are selected to provide a specific sensible heat energy output that is representative of the energy released upon failure of a lithium-ion battery cell. The temperature of the regenerator is measured using a K-type thermocouple

[104] bonded to the regenerator

[103] using a thermally stable and conductive ceramic epoxy. The regenerator

[103] at approximately 800°C is quickly removed from the furnace

[101] using a pneumatically controlled transport system

[105] and placed in a contact compression zone

[113] .

[0117] The test sample

[109] was adhered to a 1 cm thick, 4 inch x 6 inch (approximately 10.16 cm x

[0118] The surface of an aluminum support sheet

[108] having a thickness of 15.25 cm is provided. The aluminum sheet

[108] is provided with a small 90° flange to facilitate the fixing of the supported test sample to the pressure plate

[107] . A K-type thermocouple

[110] is placed in a groove with a depth of 0.5 mm on the surface of the thin aluminum support sheet

[108] opposite the test sample

[109] and is embedded in a thermally stable conductive ceramic epoxy resin so that the temperature of the opposite side of the test sample (i.e., the side not in direct contact with the heat accumulator) can be measured while maintaining the compression flatness.

[0119] The contact compression area

[113] with two flat pressing plates

[107] is used to compress the heat accumulator

[103] into contact with one side of each test sample

[109] . The plates

[107] are made of a machined stainless steel backing plate and a machined A glass ceramic front plate (Corning Incorporated, Corning, NY) was used. A thin aluminum sheet

[108] containing a supported test sample

[109] was placed on a pressure plate

[107] . The pressure plate

[107] was connected to a pneumatically controlled compression system

[112] for contacting the supported test sample with the thermal accumulator

[103] .

[0120] To initiate the test, the regenerator, at approximately 800°C, is quickly removed from the furnace

[101] and placed between two supported test specimens. A compression system

[112] is used to quickly move the platens (with supported test specimens) together, bringing the test specimens into compressive contact with the regenerator (at a pressure of ~42,300 Pa). Figure 3FIG4 is a side view showing the orientation of the elements in contact with the compression zone

[113] at the start of the test (time 0). A K-type thermocouple

[110] records the temperature of the opposite side of each test sample over time. The temperature of the heat accumulator and the temperature of the thin aluminum support sheet

[109] were recorded for a specified time (10 minutes to 60 minutes). The highest average temperature observed during the specified contact time was recorded. FIG5 is a representative graph showing the temperature of the heat accumulator and the temperature measured on the opposite side of the thermal insulation composite sample within 45 minutes after contact.

[0121] Example

[0122] Example 1

[0123] Thermal insulation composite materials

[0124] Fibrillable homopolymer polytetrafluoroethylene (PTFE) fine powder particles (12 wt%), 50 wt% fumed silica particles (Evonik % fumed silica; Evonik Corporation, Parsippany, New Jersey), 30 wt.% silicon carbide particles (opacifier) ​​[F1200 silicon carbide, Washington Mills North Grafton, Inc., North Grafton, Massachusetts], and 8 wt.% chopped glass fibers (#30 E-glass; 1 / 4 inch cut length (6.4 mm); fiber diameter 13 microns) [Fiber Glast Developments Corp., Brookville, Ohio] were blended with a mineral spirits lubricant. The blend was then formed into a tape and dried to form a thermal insulation composite in sheet form, as generally taught in U.S. Patent No. 7,868,083 to Ristic-Lehmann et al. The sheet had a thickness of approximately 1 mm and contained fibrillable PTFE particles, fumed silica particles, chopped glass fibers, and silicon carbide particles, which were durably embedded and fixed in a fibrillated PTFE matrix.

[0125] The insulating composite material samples were tested using the protective heat transfer barrier test described above. The insulating composite material sample was cut into two pieces and the two insulating composite material samples were placed on either side of the heat accumulator in the high temperature test device for testing. The maximum temperature of the two samples was observed, measured, averaged, and recorded. Table 1 provides a detailed breakdown of the test samples, including thickness, density, and corresponding performance as an insulating composite material (i.e., the average maximum temperature observed). It should be understood that the weight percentages are reported relative to the total weight of the final insulating composite material.

[0126] Thermal insulation composite materials

[0127] Example 2

[0128] Fibrillable homopolymer ultra-high molecular weight polyethylene (UHMWPE) fine powder particles (8.5 wt%), 52.2 wt% of fumed silica particles (Evonik % fumed silica; Evonik Corporation, Parsippany, New Jersey), 31.3 wt.% silicon carbide particles (opacifier) ​​[F1200 silicon carbide, Washington Mills North Grafton, Inc., North Grafton, Massachusetts], and 8 wt.% chopped glass fibers (#30 E-glass; 1 / 4 inch cut length (6.4 mm); fiber diameter 13 microns) [Fiber Glast Developments Corp., Brookville, Ohio] were blended with a mineral spirits lubricant. The blend was then formed into a tape and dried to form a thermal insulation composite in the form of a high-temperature sheet, as generally taught in U.S. Patent No. 7,868,083 to Ristic-Lehmann et al. The high-temperature sheet had a thickness of approximately 1 mm and contained fibrillable UHMWPE particles, fumed silica particles, chopped glass fibers, and silicon carbide particles, which were durably embedded and fixed in a fibrillated UHMWPE matrix.

[0129] High-temperature thermal insulation composite samples were tested using the protective heat transfer barrier test described above. Two samples were tested. The maximum temperatures for both samples were observed, measured, averaged, and recorded. Table 1 provides a breakdown of the tested samples, including thickness, density, and corresponding performance as high-temperature thermal insulation composites (i.e., the average maximum temperature observed). It should be understood that weight percentages are reported relative to the total weight of the final high-temperature thermal insulation composite.

[0130] Table 1 High temperature thermal insulation composite material samples and corresponding thermal properties of Examples 1 and 2

[0131]

[0132] The invention of this application has been described above generally and in conjunction with specific embodiments. It will be apparent to those skilled in the art that various modifications and variations may be made to the embodiments described herein without departing from the spirit and scope of the invention. Therefore, the embodiments are intended to cover such modifications and variations of the invention as come within the scope of the appended claims and their equivalents.

Claims

1. A thermal insulation composite material comprising: 50% by weight or less of a fibrillated polymer matrix; Greater than 40% by weight of insulating particles, wherein the insulating particles are selected from the group consisting of fumed silica, amorphous silica, colloidal silica, precipitated silica, fused silica, silica gels, silica xerogels, silicates, fumed metal oxides, and combinations thereof; and greater than about 1% by weight of the combined total amount of additional particulate components selected from the group consisting of one or more sunscreens, one or more reinforcing fibers, one or more expandable microspheres, and any combination thereof, wherein the weight % is based on the total weight of the final thermal insulation composite material, and in, The thermal insulation particles and additional particle components are durably embedded within the fibrillated polymer matrix. 2 . The thermal insulation composite material according to claim 1 , wherein the thermal insulation particles are fumed silica particles.

3. The thermal insulation composite material according to claim 1 or claim 2, wherein the thermal insulation composite material is a tube, a strip or a sheet having a thickness or a wall thickness of 5 mm or less.

4. The thermal insulation composite material according to any one of claims 1 to 3, wherein the fibrillated polymer matrix comprises polyolefin, ultra-high molecular weight polyethylene, fluoropolymer, polytetrafluoroethylene, expanded polytetrafluoroethylene, polyurethane, polyester, polyamide or any combination thereof.

5. The thermal insulation composite material according to any one of claims 1 to 4, wherein the polymer is polytetrafluoroethylene (ePTFE), ultra-high molecular weight polyethylene (UHMWPE) or a combination thereof.

6. The insulating composite material of any one of claims 1-5, wherein the combined total amount of the additional particulate components comprises greater than 1% by weight of one or more sunscreens.

7. The insulating composite material of any one of claims 1 to 6, wherein the additional particulate component comprises up to 30% by weight of expandable microspheres.

8. The thermal insulation composite material according to any one of claims 1 to 7, wherein the opacifier is selected from carbon black, titanium dioxide, aluminum oxide, zirconium dioxide, iron oxide, silicon carbide, molybdenum silicide, manganese oxide, polydialkylsiloxane in which the alkyl group contains 1 to 7 carbon atoms, or any combination thereof.

9. The thermal insulation composite material of any one of claims 1 to 8, wherein the one or more reinforcing fibers comprise carbon fibers, glass fibers, aluminoborosilicate fibers, or a combination thereof.

10. A thermal insulation composite material comprising: less than 50% by weight of a fibrillated polymer matrix; Less than 80% by weight of thermal insulation particles, wherein the thermal insulation particles are selected from the group consisting of fumed silica, amorphous silica, colloidal silica, precipitated silica, fused silica, silica gel, silica xerogel, silicates, fumed metal oxides, and combinations thereof; greater than about 1% by weight of at least one sunscreen; Up to 25% by weight of reinforcing fibers; and less than 20% by weight of expandable microspheres, wherein the weight % is based on the total weight of the thermal insulation composite product in the final state, and in, The thermal insulation particles and additional particle components are durably embedded within the fibrillated polymer matrix. The thermal insulation composite material according to claim 10 , wherein the thermal insulation particles are fumed silica particles.

12. The thermal insulation composite material according to claim 10 or claim 11, wherein the thermal insulation composite material is a tube, a tape or a sheet having a thickness or a wall thickness of 5 mm or less.

13. The thermal insulation composite material of any one of claims 10-12, wherein the fibrillated polymer matrix comprises polyolefin, ultra-high molecular weight polyethylene, fluoropolymer, polytetrafluoroethylene, expanded polytetrafluoroethylene, polyurethane, polyester, polyamide, or any combination thereof.

14. The thermal insulation composite material according to any one of claims 10 to 13, wherein the polymer is polytetrafluoroethylene (ePTFE), ultra-high molecular weight polyethylene (UHMWPE) or a combination thereof.

15. The insulating composite material of any one of claims 10-14, wherein the combined total amount of the additional particulate components comprises greater than 1% by weight of one or more sunscreens.

16. The insulating composite material of any one of claims 10 to 15, wherein the additional particulate component comprises up to 30% by weight of expandable microspheres.

17. The thermal insulation composite material according to any one of claims 10 to 16, wherein the opacifier is selected from carbon black, titanium dioxide, aluminum oxide, zirconium dioxide, iron oxide, silicon carbide, molybdenum silicide, manganese oxide, polydialkylsiloxane in which the alkyl group contains 1 to 4 carbon atoms, or any combination thereof.

18. The thermal insulation composite material of any one of claims 10-17, wherein the one or more reinforcing fibers comprise carbon fibers, glass fibers, aluminoborosilicate fibers, or combinations thereof.

19. An article comprising the thermal insulation composite material according to any one of claims 1 to 9.

20. An article comprising the thermal insulation composite material according to any one of claims 10 to 18.

21. Use of the thermal insulation composite material according to any one of claims 1 to 9 for preventing heat propagation in a lithium-ion battery.

22. Use of the thermal insulation composite material according to any one of claims 10 to 18 for preventing heat propagation in a lithium-ion battery.

23. An article comprising: a first component capable of generating a high temperature event comprising a first temperature; a second component to be protected from exposure to the first temperature; and a thermal insulation composite material positioned between the first component and the second component, wherein a first side of the thermal insulation composite material faces the first component and an opposite side faces the second component; the thermal insulation composite material comprising: Greater than or equal to about 40 weight percent thermal insulation particles, wherein the thermal insulation particles are selected from the group consisting of fumed silica, amorphous silica, colloidal silica, precipitated silica, fused silica, silica gel, silica xerogel, silicates, fumed metal oxides, and combinations thereof; less than or equal to about 60% by weight of a fibrillated polymer matrix; and 1% to 45% by weight of one or more additional particulate components selected from the group consisting of one or more sunscreens, one or more reinforcing fibers, one or more expandable microspheres, and any combination thereof, wherein the weight % is based on the total weight of the thermal insulation composite material in the final state, and Therein, the thermal insulation particles and the additional particle components are permanently embedded in the fibrillated polymer matrix.

24. The article of claim 23, wherein the thermally insulating particles are fumed silica particles.

25. A multilayer thermal insulation composite material comprising: A first layer and a second layer, each of the first layer and the second layer comprising: Greater than or equal to about 40 weight percent thermal insulation particles, wherein the thermal insulation particles are selected from the group consisting of fumed silica, amorphous silica, colloidal silica, precipitated silica, fused silica, silica gel, silica xerogel, silicates, fumed metal oxides, and combinations thereof; less than or equal to about 60% by weight of a fibrillated polymer matrix; and 1 wt % to 45 wt % of one or more additional particulate components selected from the group consisting of one or more sunscreens, one or more reinforcing fibers, one or more expandable microspheres, and any combination thereof, such that the total wt % equals 100 wt %, wherein the one or more additional particulate components vary along the first thickness of the first layer in one or more of chemical composition, particle size, and particle size distribution, and Wherein the one or more additional particulate components vary along the second thickness of the second layer in one or more of chemical composition, particle size, and particle size distribution.

26. The multilayer insulating composite material of claim 25, comprising a third layer, the third layer comprising one or more additional particulate components, the additional particulate components varying in one or more of chemical composition, particle size, and particle size distribution along the thickness of the third layer.

27. The multilayer insulating composite of claim 25 or claim 26, wherein the one or more additional components is an opacifier and the first layer comprises an opacifier having a first particle size distribution, the second layer comprises an opacifier having a second particle size distribution, and the third layer comprises an opacifier having a third particle size distribution.

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