Materials, systems, and methods for mitigating thermal events in electrical energy storage.

Abstract

Providing materials and systems to manage the problem of thermal runaway in energy storage systems. [Solution] A multilayer material for use as a thermal barrier in an electrical energy storage system, wherein the multilayer material comprises a core portion including a layered assembly, the layered assembly including at least one insulating layer and at least one heat-capacitating layer, and an exterior disposed outside the core portion, the exterior including at least one sacrificial material layer, the sacrificial material layer including a compressible pad, wherein the heat-capacitating layer has a specific heat capacity of at least about 200 J / (kg·K), and the insulating layer has a thermal conductivity of less than about 50 mW / m·K at 25°C and less than about 60 mW / m·K at 600°C, across the thickness dimension of the insulating layer.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims the benefit and priority of U.S. Provisional Patent Application No. 63 / 218,205, filed on 2 July 2021, entitled “Materials, Systems, and Methods for Mitigation of Electrical Energy Storage Thermal Events,” the entire contents of which are incorporated herein by reference.

[0002] This disclosure relates, in general, to materials and systems for preventing or mitigating thermal events such as thermal runaway problems in energy storage systems. In particular, this disclosure provides a multilayer thermal barrier material comprising at least one insulating layer, at least one compressible pad, and optionally one or more layers. The optional one or more layers have desirable heat dissipation properties, desirable fire resistance, flame retardancy, and / or abrasion resistance properties, and / or desirable performance for use as a thermal barrier. This disclosure further relates to a battery module or battery pack comprising one or more battery cells comprising the multilayer thermal barrier material, and similarly to a system comprising such battery module or pack. [Background technology]

[0003] Rechargeable batteries, such as lithium-ion batteries, have been found to have a wide range of applications in power-driven energy storage systems. Lithium-ion batteries (LIBs) are widely used to power portable electronic devices such as mobile phones, tablets, laptops, and power tools, and, due to their higher operating voltage, lower memory effect, and higher energy density compared to conventional batteries, they are also widely used to power other high-current devices such as electric vehicles. However, there are safety concerns because LIBs are susceptible to sudden failures under "harsh conditions," such as when overcharged (charged beyond the design voltage), over-discharged, or when operating at or exposed to high temperatures and pressures. As a result, narrow operating temperature ranges and charge / discharge rates limit the use of LIBs, as they can fail due to rapid self-heating or thermal runaway events when exposed to conditions outside their design range.

[0004] As shown in Figure 1, the electrochemical cell of a lithium-ion battery (LIB) mainly consists of a positive electrode, a negative electrode, an electrolyte capable of conducting lithium ions, a separator that separates the positive and negative electrodes, and a current collector. (LiCoO2, LiFePO4, LiMn2O4, Li2TiO3, LiNi) 0.8 Co 0.15 Al 0.05 O2(NCA) and LiNi 1 / 3 Co 1 / 3 Mn 1 / 3O2(NMC) is one of six types of cathode materials widely used in lithium-ion batteries. These six types of batteries account for the majority of the current battery market share. The electrolyte consists of a lithium salt dissolved in a specific solvent (mainly containing ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), and propylene carbonate (PC)). The lithium salt is generally selected from LiClO4, LiPF6, LiBF4, LiBOB, etc. The separator material is generally a polyolefin resin material. Microporous membranes of polypropylene (PP) and polyethylene (PE) are commonly used as separators in commercial lithium-ion batteries. Aluminum foil is commonly used as a current collector for the positive electrode and copper foil for the negative electrode. Carbon-based materials, including rigid carbon, carbon nanotubes, and graphene, are currently the main choice for the negative electrode in most commercial lithium-ion batteries. Furthermore, other novel negative electrode materials such as titanium oxides, alloy / de-alloying materials, and conversion materials have also been investigated, and these have shown good thermal and electrochemical properties.

[0005] LIB operation under normal conditions Under normal operation, lithium ions move by diffusion and migration from one electrode to the other through the electrolyte and separator.

[0006] During LIB charging, lithium ions in the electrolyte solution migrate from the cathode through the separator, inserting themselves into the anode (Figure 2). Charged equilibrium electrons also move to the anode, but they travel through the external circuitry of the charger. During discharge, a reverse flow process occurs, and electrons flow through the powered device (Figure 2). During this process, heat is generated within the cell by three main mechanisms. The first mechanism is reversible heat generated by entropy changes associated with redox reactions that occur during the lithiation process (discharge) and the delithiation process (charging). Reversible heat is also called entropy heat. The second mechanism is irreversible heat associated with electrode polarization caused by cell overpotential. Finally, there is irreversible heat associated with resistive losses, which is called Joule heating. Joule heating is due to the movement of lithium ions and electrons within the cell. Under normal conditions, self-heating is very small, generally of low importance, and can be easily dissipated by good battery design or battery temperature control systems. However, under harsh conditions, several side reactions can occur that lead to thermal runaway. Understanding the causes of thermal runaway can guide the design of functional materials to improve the safety and reliability of lithium-ion batteries (LIBs).

[0007] Overview of Thermal Runaway and Thermal Runaway Propagation Thermal runaway can occur when the internal reaction rate increases to the point where more heat is generated than can be extracted, resulting in a further increase in both reaction rate and heat generation. During thermal runaway, high temperatures trigger a chain reaction of exothermic reactions in the battery, causing the battery temperature to rise sharply. Often, when thermal runaway occurs in one battery cell, the generated heat comes into close contact with the cell experiencing the runaway reaction, rapidly heating it up. Each cell added to the runaway reaction contains additional energy that sustains the reaction, causing thermal runaway propagation within the battery pack (Figure 3), ultimately leading to a major accident such as a fire or explosion. Rapid heat dissipation and effective blocking of heat transfer pathways can be effective measures to reduce the hazards posed by thermal runaway propagation.

[0008] Induction of thermal runaway - extreme conditions Thermal runaway can be triggered by various types of runaways, including mechanical, electrical, and thermal runaways (Figure 3). Each type of runaway can induce an internal short circuit (ISC) in the battery, leading to a rise in temperature. Severe conditions can be initiated externally or internally. Internal factors that can cause various types of runaways include, for example, stress induced by service, degradation, design errors, configuration parameters such as cell spacing, cell interconnect style, and cell form factor, as well as manufacturing, operation, and maintenance. External factors include damage or injury to the LIB from cell drops or cell penetration, etc.

[0009] Machine runaway Mechanical runaway is primarily caused by mechanical forces and is usually triggered by external factors such as serious car accidents, including collisions, shattering, penetration, and bending. When a battery or battery pack is impacted or caught in a collision, potential damage can occur inside the battery, including separator rupture and leakage of flammable electrolyte, initiating ISC, which then leads to thermal runaway. Destructive deformation and displacement caused by the applied force are two common characteristics of mechanical runaway. Battery pack deformation is quite possible during car collisions. The layout of the battery pack in electric vehicles affects the collision response of the battery pack. Battery pack deformation can have dangerous consequences. Battery separators can be torn, causing internal short circuits (ISC). Flammable electrolyte leaks, potentially resulting in a fire. Penetration is another common phenomenon that can occur during vehicle collisions. Compared to shattering, penetration can instantly induce a severe ISC when it begins. Mechanical failure and electrical short circuits can occur simultaneously, and the severe conditions of penetration can be even more serious than simple mechanical or electrical runaway.

[0010] Electrical runaway Electrical runaway primarily includes internal or external short circuits, overcharging, and over-discharging of lithium-ion batteries (LIBs).

[0011] Internal short circuits occur in over 90% of severe conditions. Roughly speaking, an internal short circuit occurs when the cathode and anode collide with each other due to a failure in the battery separator. Internal short circuits can be caused by (1) mechanical runaway when the separator fails due to penetration or shattering, (2) electrical runaway when the separator penetrates due to dendrite growth (Figure 4), and (3) thermal runaway when the separator collapses due to high temperature.

[0012] An external short circuit is formed when electrodes with a voltage difference are connected by a conductor. External short circuits in battery packs can occur due to deformation during a car crash, water ingress, contamination by conductors, or electric shocks during maintenance. Compared to penetration, generally, the heat released on the circuit in an external short circuit does not heat the cells. An external short circuit can cause high current and high heat generation in the battery, which is mainly due to heat generation according to Ohm's law. When the temperature begins to exceed about 70°C, the cells begin to break down. This can result in discharge and electrolyte leakage.

[0013] Overcharging can be defined as charging a battery beyond its design voltage. Overcharging can cause a series of problems, including the deposition of Li metal on the anode, and can be induced by a characteristic high current density, a vigorous charging profile, the decomposition of the cathode material which releases oxygen, and the decomposition of the organic electrolyte which releases heat and gaseous products (H2, hydrocarbons, CO, etc.), which seriously affect the electrochemical performance and safety of the battery. The overcharging process can be divided into three stages. In the first stage, (1) the voltage and temperature remain unaffected and virtually unchanged. In the second stage, (2) lithium dendrite deposition occurs on the voltage platform. And in the third stage, (3) as heat and gases are generated, the voltage drops dramatically and thermal runaway occurs in the battery.

[0014] Over-discharge is another potential electrical stressor. Generally, voltage mismatches among multiple cells in a battery pack are unavoidable. Therefore, if the battery management system fails to monitor the voltage of any single cell, the cell with the lowest voltage will over-discharge. The mechanism of runaway over-discharge differs from other mechanisms, and its potential danger may be underestimated. The cell with the lowest voltage in a battery pack may be forcibly discharged by other cells connected in series during over-discharge. During forced discharge, the poles reverse, the cell voltage becomes negative, and abnormal heat generation occurs in the over-discharged cell.

[0015] thermal runaway Thermal runaway is generally induced by overheating. Overheating of lithium-ion batteries can occur due to mechanical runaway, electrical runaway, and connector contact loss. Generally, LIBs are stable at their normal operating temperature. However, above a certain temperature, the stability of the LIB becomes unpredictable, and as the temperature rises, chemical reactions within the battery case produce gases that lead to an increase in internal pressure within the battery case. These gases may further react with the cathode, releasing more heat and creating temperatures inside or adjacent to the battery that can ignite the electrolyte in the presence of oxygen. When the electrolyte burns, oxygen is produced, further intensifying the combustion. At some point, the increase in pressure within the battery case can lead to the battery case rupturing. Leaked gases can ignite and burn.

[0016] Thermal runaway, caused by mechanical, electrical, and thermal extreme conditions, can induce continuous heat generation, resulting in a rise in temperature inside the battery. A series of chain reactions may occur at different stages as the temperature increases. Thermal runaway follows, for example, the chain reaction mechanisms of physical and / or chemical processes, during which decomposition reactions of the battery component materials occur one after another (Figure 3).

[0017] Overview of a chain reaction during thermal runaway Understanding the evolution of these physical and / or chemical processes helps to develop mitigation strategies for LIB thermal runaway. LIB can result in different thermal runaway inductions in different temperature states or regimes, including state I: low temperature (<0 °C), state II: normal temperature (0 - 90 °C), and state III: high temperature (>90 °C) (Figure 5).

[0018] In state I, at low temperatures, LIB cannot operate efficiently because it causes a decrease in the rate of electrochemical reactions. At low temperatures, as a result of the decrease in the activity of electrode materials and the lithium ion diffusion rate in the electrolyte, battery performance drops dramatically. The result of the deceleration of chemical reactions at low temperatures includes unwanted Li deposition, plating, and dendrite growth. Dendrites are tree-like structures that can form on the lithium plating of the battery. Dendrites can quickly penetrate the porous plastic film between the battery's separator and the anode and cathode of the battery (Figure 4). Li deposition and dendrite growth within the cell are regarded as the main factors for inducing thermal runaway at low temperatures. Without wishing to be bound by theory, it is considered possible that unwanted Li deposition and dendrites can cause ISC in the battery, leading to thermal runaway.

[0019] In State II (operation at normal temperature), heat generation is minimized compared to the heat generated in the thermal runaway process. The heat generation during this operating state is mainly caused by solid and liquid-phase Li-ion diffusion, electrochemical reactions at the solid-liquid interface, and side reactions. Heat generation can cause temperature increases and temperature differences inside the battery, and these temperature differences can affect the life and safety of the lithium-ion battery. During Stage II, initial overheating can occur as a result of at least one of the above-described internal or external inductions such as overcharging of the battery, exposure to excessive temperatures, external short circuits due to miswiring, or internal short circuits due to cell defects. When initial overheating starts, as the temperature rises towards 90 °C, the battery operation changes from the normal state to the abnormal state. When the temperature is higher than 40 °C, the life of the lithium-ion battery can be shortened because side reactions speed up, and when the temperature is about 90 °C or higher, it may induce the decomposition of the solid electrolyte interphase (SEI) film, which is defined as the start of thermal runaway. SEI is formed on the anode of the lithium-ion battery during the first few cycles of the charge cycle. SEI provides a passivation layer on the anode surface, and the passivation layer prevents further electrolyte decomposition and provides the long calendar life required for many applications. The initial decomposition of SEI is regarded as the first side reaction occurring during the entire thermal runaway process. The initial decomposition of SEI occurs at 80 - 120 °C and shows a peak at about 100 °C. The starting temperature can be lower than 80 °C, as reported by Wang et al. (Thermochim. Acta 437 (2005) 12 - 16), where the decomposition of SEI may start from a temperature as low as 57 °C.

[0020] Decomposition of SEI When Stage III starts, the internal temperature rises rapidly, resulting in the decomposition of the SEI film. The SEI layer mainly consists of stable components (such as LiF and Li2CO3) and metastable components (such as polymers, ROCO2Li, (CH2OCO2Li)2, and ROLi). However, the metastable components can thermally decompose and release combustible gases and oxygen at temperatures generally exceeding 90 °C. The decomposition of the SEI film is considered to be the start of thermal runaway, and then a series of exothermic reactions are induced.

[0021] When SEI decomposition occurs, the temperature rises, and the lithium metal anode or intercalated lithium reacts with the organic solvent in the electrolyte, releasing flammable hydrocarbon gases (ethane, methane, etc.). This is an exothermic reaction that further intensifies the temperature rise.

[0022] Disassembly of the separator When T (temperature) > approximately 130°C, the polyethylene (PE) / polypropylene (PP) separator begins to melt, and the situation worsens, resulting in a short circuit between the cathode and anode. The melting of the PE / PP separator is a thermal adsorption process, but the ISC (Internal Stabilization Cycle) produced by the melting of the separator further exacerbates the thermal runaway process.

[0023] Gas emission and decomposition of electrolytes When the temperature (T) exceeds approximately 180°C, the heat generated by ISC causes the decomposition of the lithium metal oxide cathode material, leading to the release of oxygen. Furthermore, cathode failure generates even more heat, further increasing the temperature and pressure, and consequently accelerating the reaction. Subsequently, heat accumulation and gas release (oxygen and flammable gases) induce combustion and explosion of the lithium-ion battery.

[0024] In a thermal runaway process, only 2% of the heat generated by ISC is due to chemical reactions, including the decomposition of the SEI layer and electrolyte, while 98% is due to chemical reactions. The largest proportion of heat generated, approximately 48%, comes from the rapid redox reaction between the cathode and anode, while the heat generated by other chemical reactions in the anode, cathode, and electrolyte is much smaller. The least heat generated is from the decomposition of the SEI film.

[0025] The need for mitigation measures against thermal runaway Based on an understanding of the mechanisms that cause battery thermal runaway, many approaches have been explored with the goal of reducing safety hazards through the rational design of battery components. To prevent such cascaded thermal runaway events from occurring, LIBs are generally designed to either keep the stored energy sufficiently low, utilize sufficient insulating material between cells within the battery module or battery pack, isolate cells from thermal events that may occur in adjacent cells, or a combination of these. The former strictly limits the amount of energy that can potentially be stored in such a device. The latter limits the effective energy density by restricting the arrangements in which closed cells can be installed. Effective insulation and heat dissipation measures are needed to mitigate the potential for thermal runaway in LIBs.

[0026] Current heat dissipation methods used for LIBs Currently, several different methods are employed to maximize energy density while taking precautions to prevent cascading thermal runaway. One approach involves incorporating sufficient insulation between cells or between clusters of cells. This approach is generally desirable due to its safety advantages. However, this approach has an upper limit on the achievable energy density, determined by the required volume of insulation combined with the insulating material's ability to contain heat. Another approach involves using phase-change materials. These materials undergo an endothermic phase change when they reach a certain temperature. The endothermic phase change absorbs some of the heat being generated, thereby cooling the local area. Generally, with respect to electrical storage devices, these phase-change materials rely on hydrocarbon materials such as waxes and fatty acids. While these systems are effective in cooling, they are flammable, and if ignition occurs within the storage device, they are not beneficial in preventing thermal runaway. Incorporating expansion materials is another measure to prevent cascading thermal runaway. These materials expand above a specified temperature, producing carbides designed to be lightweight and providing insulation when needed. While these materials can be effective in providing insulating benefits, the expansion of the materials must be considered when designing storage devices.

[0027] The need for a new thermal barrier to meet the mechanical requirements of the LIB system. During charging and discharging, the expansion of the anode and cathode can result in changes in the cell's dimensions (expansion). For example, silicon undergoes a volume change of up to 300% during intercalation, while graphite undergoes a volume expansion of approximately 10%. This change results in both reversible and irreversible components, with magnitudes depending on the exact cell chemical reaction. Reversible changes in cell thickness depend solely on the cell's state of charge (SOC) and can result in thickness increases greater than 2%. Irreversible cell expansion is associated with increased pressure inside the cell and is caused by the formation of SEI (Sectional Integral Isolation). The greatest factor in this change occurs during the first charging cycle when the SEI is first formed, but expansion continues throughout the cell's lifespan.

[0028] While extensive research is being conducted to create novel materials with desirable thermal properties to prevent thermal runaway problems, the mechanical properties of these materials, despite their importance, receive little attention. For example, an effective thermal barrier is needed between cells in a battery module or battery pack that can provide resistance to compressive deformation to accommodate the continuous expansion of cells throughout their lifespan. In addition, relatively low loads of less than 1 MPa are generally applied to the material between cells during the initial assembly of a battery module. When cells inside a battery module or battery pack expand or swell during a charge / discharge cycle, loads of up to approximately 5 MPa can be applied to the material between cells. Therefore, the compressibility, compressive elasticity, and compliance of the material, such as the thermal barrier between cells, are critical properties.

[0029] Therefore, a novel thermal barrier is needed to meet the mechanical requirements of the LIB system in order to provide effective insulation under thermal runaway conditions and effective heat dissipation under normal conditions. [Overview of the project]

[0030] The purpose of this disclosure is to prevent or mitigate at least one of the disadvantages of the aforementioned methods and materials described above in order to prevent or mitigate thermal runaway in rechargeable batteries, such as lithium-ion batteries. The multilayer materials provided herein are designed to improve the safety of lithium-ion batteries.

[0031] In particular, the object of this disclosure is to provide multilayer materials for use as thermal barriers in electrical energy storage systems, solving the problem of heat transfer in battery modules or battery packs, and stopping or mitigating heat transfer when one cell experiences thermal runaway. The unique configuration of the multilayer materials of this disclosure can help solve the problem of heat transfer between cells.

[0032] Mitigation measures can be effective at the material, cell, and system levels, ensuring the overall safety of energy storage systems using rechargeable batteries such as lithium-ion batteries. The multilayer materials of this disclosure can perform at least one of the following mitigation steps: (1) reducing the likelihood of severe conditions; (2) eliminating severe conditions at the time a runaway occurs; (3) improving the thermal stability of battery cells in contact with severe conditions; (4) reducing the energy released under normal operating conditions and in the event of thermal runaway; and (5) reducing propagation hazards and limiting damage to a limited area.

[0033] Another object of this disclosure is to provide a battery module or battery pack comprising a multilayer material according to the present invention that can protect the battery pack from thermal damage due to thermal runaway of a single cell and ensure a safe design for the battery pack.

[0034] In one overall embodiment, the Disclosure provides novel multilayer materials comprising aerogel compositions, such as reinforced aerogel compositions. Aerogel compositions are durable, easy to handle, and have desirable resistance to heat and fire propagation while minimizing the thickness and weight of the materials used, as well as having desirable properties with respect to compressibility, compressive resilience, and compliance. For example, multilayer materials according to embodiments disclosed herein may comprise at least one insulating layer comprising an aerogel composition or a reinforced aerogel composition.

[0035] In one overall embodiment, the multilayer materials disclosed herein are useful for isolating, insulating, and protecting battery cells or battery components of any configuration of battery, such as pouch cells, cylindrical cells, prism cells, and packs and modules that incorporate or contain any such cells. The multilayer materials disclosed herein are useful in rechargeable batteries, such as lithium-ion batteries, solid-state batteries, and any other energy storage devices, or in technologies that require isolation, insulation, and protection.

[0036] In one overall aspect, the present disclosure aims to provide battery modules and battery packs used to simultaneously improve the heat dissipation performance and thermal runaway protection performance of power batteries. Referring to Figure 6, in a power-driven energy storage system, it is common for several cells 100 to be packed together in a pre-selected configuration (e.g., in parallel, in series, or combined) to form a battery module. Several such battery modules 200 can further be combined or joined to form various battery packs 300 known in the art. During operation and discharge, such cells, battery modules, or battery packs typically generate or produce a quantity of heat that can significantly adversely affect the performance resulting therefrom. Therefore, it is generally important to maintain the temperature of such cells, or the resulting battery module or battery pack, within a properly narrow specified range in order to maintain desired or optimal performance. The objective of the present disclosure is to maintain the temperature of such cells, battery modules, or battery packs within an optimal range.

[0037] In addition to maintaining the cell temperature within a specified range, the purpose is also to maintain the structural integrity of the cell. The materials within the cell need to have both flexibility and resilience to adapt to volume changes during battery operation. In some embodiments, the materials need to be flame-retardant or fire-resistant to maintain structural integrity after or during thermal events.

[0038] In one embodiment, a multilayer material provided herein for use as a thermal barrier in an electrical energy storage system comprises a core portion including a layered assembly of at least one insulating layer and at least one heat-capacitating layer stacked alternately in a direction perpendicular to its maximum surface, and an exterior portion located outside the core portion, comprising at least one sacrificial material layer including a compressible pad, and at least one encapsulating material layer selected from polymers, elastomers, or a combination thereof. In some embodiments, the sacrificial material layer has a compressive force deflection (CFD) of 25% at about 20 kPa to about 100 kPa, for example, about 27 kPa to about 55 kPa.

[0039] In another embodiment, a multilayer material provided herein for use as a thermal barrier in an electrical energy storage system comprises a core portion comprising a layered assembly of at least one insulating layer and at least one thermal conductive layer stacked alternately in a direction perpendicular to its maximum surface, and an exterior portion disposed outside the core portion comprising at least one sacrificial material layer and at least one encapsulating material layer selected from polymers, elastomers, or a combination thereof. In some embodiments, the sacrificial material layer has a compressive force deflection (CFD) of 25% at about 20 kPa to about 100 kPa, for example, about 27 kPa to about 55 kPa.

[0040] In one embodiment, a multilayer material provided herein for use as a thermal barrier in an electrical energy storage system includes a core portion comprising at least one insulating layer; an external portion located outside the core portion and comprising at least one sacrificial material layer comprising a compressible pad having a compressibility coefficient of about 1 MPa to about 12 MPa; and at least one encapsulating material layer selected from polymers, elastomers, or a combination thereof, wherein the encapsulating material layer is sandwiched between the core portion and the external sacrificial material layer. In some embodiments, the core portion further comprises at least one heat capacity layer having a specific heat capacity of at least about 200 J / (kg·K). In some embodiments, the core portion comprises a layered assembly of at least one insulating layer and at least one heat capacity layer stacked alternately in a direction perpendicular to its maximum surface. In some embodiments, the core portion further comprises at least one heat conduction layer having a thermal conductivity of at least about 200 mW / m·K along the in-plane dimensions of the heat conduction layer. In some embodiments, the core portion includes a layered arrangement of at least one insulating layer and at least one thermal conductive layer that are alternately stacked in a direction perpendicular to its largest surface.

[0041] In another embodiment, a multilayer material provided herein for use as a thermal barrier in an electrical energy storage system comprises a core layer having two sides comprising at least one compressible material layer having a compressibility coefficient of about 1 MPa to about 12 MPa, and optionally at least one thermal conductive layer and / or at least one thermal capacity layer, and two insulating layers having a thermal conductivity of less than about 50 mW / m·K at 25°C and less than about 60 mW / m·K at 600°C through the thickness dimension of the insulating layer, wherein the core layer is sandwiched by the two insulating layers, the optional at least one thermal conductive layer having an in-plane thermal conductivity of at least about 200 mW / m·K, and the optional at least one thermal capacity layer having a specific heat capacity of at least about 200 J / (kg·K), and the multilayer material is optionally encapsulated in an encapsulating material selected from at least one of polymers, elastomers, or a combination thereof. In some embodiments, the core layer further comprises a flame retardant layer. In some embodiments, the core layer lacks an optional at least one thermal conduction layer and an optional at least one heat capacity layer. In some embodiments, the core layer includes an optional at least one thermal conduction layer and lacks an optional at least one heat capacity layer. In some embodiments, the core layer includes two thermal conduction layers and one compressible material layer, the compressible material layer being sandwiched between the two thermal conduction layers. In some embodiments, the core layer includes an optional at least one heat capacity layer and lacks an optional at least one thermal conduction layer. In some embodiments, the core layer includes two thermal conduction layers and one compressible material layer, the compressible material layer being sandwiched between the two thermal conduction layers. In some embodiments, the core layer includes one heat capacity layer and two compressible material layers, the heat capacity layer being sandwiched between the two compressible material layers. In some embodiments, the multilayer material further includes two heat capacity layers, each heat capacity layer located on the outer surface of each insulating layer.

[0042] Any embodiment of the above aspects may include one or more of the following features. For example, in some embodiments, the encapsulation material layer is sandwiched between the core and the sacrificial material layer. In some embodiments, the sacrificial material layer comprises a material selected from the group consisting of siloxane, polyolefin, polyurethane, phenol, melamine, cellulose acetate, and polystyrene. In some embodiments, the sacrificial material layer is in the form of a foam. In one or more embodiments, the onset temperature of the chemical decomposition of the sacrificial material layer is in the range of about 200°C to about 400°C.

[0043] In some embodiments, the exterior further includes a layer made of a material selected from a group of materials such as abrasion-resistant materials, expansion materials, flame-retardant materials, non-combustible materials, or combinations thereof.

[0044] In some embodiments, the heat capacity layer has a specific heat capacity of at least about 200 J / (kg·K). In some embodiments, the heat capacity layer is a phase change material. In some embodiments, the heat capacity layer includes stainless steel.

[0045] In some embodiments, the encapsulation material layer is a polyethylene terephthalate layer.

[0046] In some embodiments, the encapsulation material layer further includes a metal layer positioned between the encapsulation layer and the core.

[0047] In some embodiments, the insulating layer has a thermal conductivity of less than about 50 mW / m·K at 25°C and less than about 60 mW / m·K at 600°C, across the thickness dimension of the insulating layer. In some embodiments, the insulating layer comprises aerogel. In some embodiments, the insulating layer further comprises a material selected from the group consisting of mica, porous silica, ceramic fibers, mineral wool, and combinations thereof. In some embodiments, the insulating layer is aerogel-deficient, and the insulating layer further comprises a material selected from the group consisting of mica, porous silica, ceramic fibers, mineral wool, and combinations thereof.

[0048] In some embodiments, the thermal conductive layer has a thermal conductivity of at least about 200 mW / m·K along the in-plane dimensions of the thermal conductive layer. In some embodiments, the thermal conductive layer comprises at least one layer including a metal, carbon, a conductive polymer, or a combination thereof. In some embodiments, the thermal conductive layer is a phase-change material. In some embodiments, the thermal conductive layer is a metal selected from aluminum, copper, and steel. In some embodiments, the thermal conductive layer conducts heat away from a localized thermal load, preferably to an environment. In some embodiments, the thermal conductive layer is a form selected from the group consisting of mesh, sheet, perforated sheet, foil, and perforated foil. In some embodiments, the thermal conductivity of the insulating layer, for example, aerogel, across its thickness dimensions at 25°C remains the same or increases by a small amount when subjected to a maximum load of about 5 MPa. In some embodiments, the thermal conductivity of the insulating layer across its thickness dimensions increases by less than about 50 mW / m·K at 25°C when subjected to a maximum load of about 5 MPa. In some embodiments, the thermal conductive layer includes aluminum.

[0049] In some embodiments, the insulating layer containing the aerogel further includes a reinforcing material. In some embodiments, the reinforcing material is a fiber selected from organic polymer fibers, inorganic fibers, carbon fibers, or a combination thereof. In some embodiments, the fiber is in the form of separate fibers, woven materials, dry-laid nonwoven materials, wet-laid nonwoven materials, needle-punched nonwovens, padding, webs, mats, felts, and / or combinations thereof. In some embodiments, the inorganic fiber is selected from glass fibers, rock fibers, metal fibers, boron fibers, ceramic fibers, basalt fibers, or a combination thereof. In one or more embodiments, the aerogel includes a silica-based aerogel. In one or more embodiments, the aerogel includes one or more additives, the additives present at a level of at least about 5 to 40 weight percent of the aerogel, preferably at at least about 5 to 20 weight percent of the aerogel, and more preferably at at least about 10 to 20 weight percent of the aerogel. In some embodiments, one or more additives include a fire-resistant additive. In some embodiments, one or more additives include an opacifier selected from B4C, diatomaceous earth, manganese ferrite, MnO, NiO, SnO, Ag2O, Bi2O3, TiC, WC, carbon black, titanium oxide, iron titanium oxide, zirconium silicate, zirconium oxide, iron(I) oxide, iron(III) oxide, manganese dioxide, iron titanium oxide (ilmenite), chromium oxide, or mixtures thereof. In some embodiments, one or more additives include an opacifier containing silicon carbide. In some embodiments, one or more additives include a combination of a fire-resistant additive and an opacifier. In one or more embodiments, the aerogel has a density in the range of about 0.25 g / cc to about 1.0 g / cc. In some embodiments, the aerogel has a flexural modulus of about 2 MPa to about 8 MPa. In some embodiments, the aerogel yields a set compression in the range of about 10% to about 25% at about 70°C. In some embodiments, the aerogel exhibits compressive resistance, with the compressive resistance at 25% strain ranging from approximately 40 kPa to approximately 180 kPa. In one or more embodiments, the aerogel is in the form of a monolith, beads, particles, granules, powder, thin film, sheet, or a combination thereof.

[0050] In some embodiments, the thermal conductive layer comprises at least one layer including a metal, carbon, a conductive polymer, or a combination thereof. In some embodiments, the thermal conductive layer is a phase-change material. In some embodiments, the thermal conductive layer is a metal selected from aluminum, copper, and steel. In some embodiments, the thermal conductive layer conducts heat away from a localized thermal load, preferably to an environment. In some embodiments, the thermal conductive layer is a form selected from the group consisting of mesh, sheets, perforated sheets, foils, and perforated foils. In some embodiments, the thermal conductivity of the insulating layer, for example, aerogel, across its thickness dimension at 25°C remains the same or increases slightly when subjected to a maximum load of about 5 MPa. In some embodiments, the thermal conductivity of the insulating layer across its thickness dimension increases by less than about 50 mW / m·K at 25°C when subjected to a maximum load of about 5 MPa.

[0051] In another embodiment, a multilayer material for use as a thermal barrier in an electrical energy storage system is provided herein. The multilayer material comprises a core portion including a layered assembly, the layered assembly comprising at least one insulating layer and at least one thermal capacity layer. The exterior is located outside the core portion and comprises at least one sacrificial material layer, the sacrificial material layer comprising a compressible pad having a compressive force deflection (CFD) of 25% at about 20 kPa to about 100 kPa, for example, about 27 kPa to about 55 kPa. The thermal capacity layer has a specific heat capacity of at least about 200 J / (kg·K), and the insulating layer has a thermal conductivity of less than about 50 mW / m·K at 25°C and less than about 60 mW / m·K at 600°C, through the thickness dimension of the insulating layer.

[0052] In another embodiment, a multilayer material for use as a thermal barrier in an electrical energy storage system is provided herein. The multilayer material comprises a core portion including a layered assembly, the layered assembly including at least one insulating layer and at least one thermal conductive layer. The exterior is located outside the core portion and includes at least one sacrificial material layer having a compressive force deflection (CFD) of 25% at about 20 kPa to about 100 kPa, for example, about 27 kPa to about 55 kPa. The thermal conductive layer has a thermal conductivity of at least about 200 mW / m·K along the in-plane dimensions of the thermal conductive layer, and the insulating layer has a thermal conductivity of less than about 50 mW / m·K at 25°C and less than about 60 mW / m·K at 600°C through the thickness dimensions of the insulating layer.

[0053] In one embodiment, a multilayer material for use as a thermal barrier in an electrical energy storage system includes a core layer comprising at least one compressible material layer having a compressibility coefficient of about 1 MPa to about 12 MPa, and at least one thermal conductive layer and / or at least one thermal capacity layer. The multilayer material also includes two of the above insulating layers having a thermal conductivity of less than about 50 mW / m·K at 25°C and less than about 60 mW / m·K at 600°C, through the thickness dimension of the insulating layers. The core layer is sandwiched between the two insulating layers. The multilayer material is optionally encapsulated in an encapsulating material.

[0054] In one embodiment, the use of multilayer materials according to various embodiments of any of the above embodiments of a battery pack including multiple single battery cells or modules of battery cells is provided herein for thermally isolating single battery cells or modules of battery cells from one another. In some embodiments, a runaway event occurring in one or more battery cells or modules of battery cells of a portion of the battery does not result in damage to the battery cells or modules of the portion of the battery that is isolated from the portion of the battery where the runaway event occurs by multilayer materials according to any of the above embodiments.

[0055] In another embodiment, various embodiments of any of the above embodiments of a battery pack including a plurality of single battery cells or modules of battery cells, for thermally isolating a single battery cell or a module of battery cells from one another, multilayer materials according to the claims are provided herein.

[0056] In one embodiment, a battery module provided herein includes a first battery cell having a first surface, a second battery cell having a second surface, the second surface facing the first surface, and a multilayer material disposed between the first surface and the second surface according to various embodiments of any of the above embodiments. In some embodiments, the multilayer material covers at least about 80% of the surface area of ​​the opposing first and second surfaces.

[0057] In another embodiment, a battery module provided herein comprises at least one battery cell and a multilayer material according to various embodiments of any of the above embodiments, wherein the multilayer material is disposed on the surface of at least one battery cell or on the surface of the battery module.

[0058] In one embodiment, a battery pack provided herein includes a plurality of cells and a spacer positioned between two adjacent cells or two adjacent modules, wherein the spacer includes a multilayer material according to various embodiments according to any of the above embodiments.

[0059] A battery module or battery pack according to any of the above embodiments further includes a cooling system configured to remove heat from the battery pack. In some embodiments, at least one layer of the multilayer material is in thermal communication with the cooling system. In some embodiments, a thermal conductive layer is in thermal communication with the cooling system.

[0060] In other embodiments, the devices or vehicles provided herein include a battery module or battery pack according to any one of the embodiments described above. In some embodiments, the devices are laptop computers, PDAs, mobile phones, tag scanners, audio devices, video devices, display panels, video cameras, digital cameras, desktop computers, military portable computers, military telephones, laser rangefinders, digital communication devices, sensitive information gathering sensors, electronically integrated clothing, night vision devices, power tools, calculators, radios, remote control devices, GPS devices, handheld and portable televisions, car starters, flashlights, acoustic devices, portable heating devices, portable vacuum cleaners, or portable medical tools. In some embodiments, the vehicles are electric vehicles.

[0061] In one or more embodiments, the multilayer material according to any of the above embodiments has an average thickness in the range of about 2 mm to about 10 mm in an uncompressed state.

[0062] The multilayer materials described herein may offer one or more advantages over existing thermal runaway mitigation measures. These multilayer materials can minimize or eliminate thermal runaway propagation in cells and assembly costs without significantly affecting the energy density of the battery module or battery pack. The multilayer materials of this disclosure can provide favorable properties regarding compressibility, compressive resilience, and compliance to accommodate the continuous cell expansion throughout the cell's lifespan, while maintaining favorable thermal properties under normal operating conditions and thermal runaway conditions. The multilayer materials described herein are durable, easy to handle, offer favorable resistance to heat and fire propagation while minimizing the thickness and weight of the materials used, and also possess favorable properties regarding compressibility, compressive resilience, and compliance.

[0063] Therefore, the attached figures, which are described in general terms in this disclosure but are not necessarily drawn to scale, are referenced here. [Brief explanation of the drawing]

[0064] [Figure 1] This is a schematic diagram of the electrochemical cell of a lithium-ion battery. [Figure 2] This is a schematic diagram of the charging and discharging process of a lithium-ion battery. [Figure 3] This diagram schematically illustrates the severe thermal runaway conditions and thermal runaway propagation process within a battery module. [Figure 4] This is a schematic diagram of dendrite growth on lithium plating of a battery. [Figure 5] The three stages that lead to a thermal runaway process are outlined below. [Figure 6] A schematic diagram of a battery cell, battery module, and battery pack is shown. [Figure 7] A schematic representation of a multilayer material according to a specific embodiment disclosed herein is shown. [Figure 8] A schematic representation of a multilayer material according to a specific embodiment disclosed herein is shown. [Figure 9A] The embodiments disclosed herein schematically illustrate multilayer materials for use as thermal barriers in electrical energy storage systems. [Figure 9B] The embodiments disclosed herein schematically illustrate multilayer materials for use as thermal barriers in electrical energy storage systems. [Figure 9C] The embodiments disclosed herein schematically illustrate multilayer materials for use as thermal barriers in electrical energy storage systems. [Figure 9D] The embodiments disclosed herein schematically illustrate multilayer materials for use as thermal barriers in electrical energy storage systems. [Figure 9E] The embodiments disclosed herein schematically illustrate multilayer materials for use as thermal barriers in electrical energy storage systems. [Modes for carrying out the invention]

[0065] The following detailed description of preferred embodiments includes references to accompanying drawings that form part of it and illustrate specific embodiments in which the disclosure may be implemented. It should be understood that other embodiments may be utilized and structural modifications may be made without departing from the scope of the disclosure.

[0066] This disclosure covers multilayer materials and systems, including multilayer materials, for managing the problem of thermal runaway in energy storage systems. Exemplary embodiments include a multilayer material comprising at least one insulating layer, at least one compressible pad, and one or more optional layers. The one or more optional layers have desirable heat dissipation properties, desirable fire resistance, flame retardancy, and / or abrasion resistance properties, and have desirable performance for use as a thermal barrier. This disclosure further relates to a battery module or battery pack comprising one or more battery cells and a multilayer thermal barrier material installed in thermal communication with the battery cells.

[0067] One or more insulating layers of the multilayer materials disclosed herein may comprise an aerogel composition or a reinforced aerogel composition. Aerogel materials are known to possess about 2 to 6 times the thermal resistance of other common types of insulating materials, such as foams and fiberglass. Aerogels can improve effective shielding and thermal insulation without substantially increasing the thickness of the insulating material or adding additional weight. Aerogels are known to be a structural classification having low density, an open-cell structure, a large surface area, and nanometer-scale pore diameters.

[0068] Multilayer materials according to embodiments of the present disclosure, and multilayer materials including aerogel compositions, provide desirable properties with respect to compressibility, compressive resilience, and compliance. When used as a thermal barrier between cells in a battery module, the multilayer material may provide resistance to compressive deformation that adapts to cell expansion due to degradation and expansion of the active material during the battery's charge / discharge cycle.

[0069] This disclosure also provides a battery module or battery pack comprising at least one battery cell and a multilayer material, arranged on a battery cell or battery module, for example, on the surface of at least one battery cell or on the surface of a battery module, according to embodiments disclosed herein. For example, the battery module or battery pack has an inner surface and an outer surface. In certain embodiments, the multilayer material is on the inner surface of the battery module or battery pack. In certain embodiments, the multilayer material is on the outer surface of the battery module or battery pack.

[0070] The multilayer materials of this disclosure may have a variety of unique configurations in which two or more layers having thermally and / or mechanically favorable properties are arranged in a particular manner. Figure 7 shows an exemplary multilayer material 400 according to embodiments disclosed herein. In one embodiment, the multilayer material 400 for use as a thermal barrier in an electrical energy storage system includes a core portion 700 comprising a layered assembly of insulating layers 470 and 480 and heat-capacitating layers 430, 440, and / or 450 alternately stacked in a direction perpendicular to the maximum surface, and an outer portion 600 disposed outside the core portion 700, wherein each outer portion 600 has a sacrificial material layer comprising a compressible pad. The compressible pads 410 / 460 have a compressibility coefficient of about 1 MPa to about 12 MPa. The encapsulating material layer 420 is selected from a polymer, an elastomer, or a combination thereof. The heat-capacitating layers 430, 440, and 450 have a specific heat capacity of at least about 200 J / (kg·K). The insulating layers 470 and 480 have a thermal conductivity of less than approximately 50 mW / m·K at 25°C and less than approximately 60 mW / m·K at 600°C, across the thickness dimensions of the insulating layers.

[0071] In some embodiments, insulating layers 470 and 480 are made from the same material. In some embodiments, insulating layers 470 and 480 are made from different materials having different thermal and / or mechanical properties. In some embodiments, heat-capacitating layers 430, 440, and 450 are made from the same material. In some embodiments, heat-capacitating layers 430, 440, and 450 are made from different materials having different thermal and / or mechanical properties. Also, the compressible pads 410 and 460 can be made from different or the same material.

[0072] Figure 8 shows a multilayer material 500 according to an embodiment disclosed herein. In one embodiment, the multilayer material 500 for use as a thermal barrier in an electrical energy storage system includes a core 700 comprising a layered assembly of insulating layers 470 and 480 and thermal conductive layers 530, 540, and 550, alternately stacked in a direction perpendicular to the maximum surface. The outer 600 is located outside the core 700. Each outer 600 has a sacrificial material layer including a compressible pad. The compressible pads 410 / 460 have a compressibility coefficient of about 1 MPa to about 12 MPa. The encapsulating material layer 420 is selected from a polymer, elastomer, or a combination thereof. The thermal conductive layers 530, 540, and 550 have a thermal conductivity of at least about 200 mW / m·K along the in-plane dimensions of the thermal conductive layer. The insulating layers 470 and / or 480 have a thermal conductivity of less than approximately 50 mW / m·K at 25°C and less than approximately 60 mW / m·K at 600°C, throughout the thickness dimension of the insulating layer.

[0073] In some embodiments, the thermal conductive layers 530, 540, and 550 are made from the same material. In some embodiments, the thermal conductive layers 530, 440, and 550 are made from different materials having different thermal and / or mechanical properties.

[0074] In some embodiments, as shown in Figures 7 and 8, the encapsulation material layer 420 is sandwiched between the core portion 700 and a sacrificial material layer having at least one compressible pad 410 and / or 460. In some embodiments, the sacrificial material layer having at least one compressible pad 410 and / or 460 is sandwiched between the core portion 700 and the encapsulation material layer 420.

[0075] Multilayer materials according to the embodiments disclosed herein may have an average thickness in the range of about 2 mm to about 10 mm in an uncompressed state. The average thickness of the multilayer material may decrease when exposed to external mechanical loads of, for example, less than 1 MPa, such as loads applied to the material between cells during the initial assembly of a battery module.

[0076] In the exemplary configuration of the multilayer material shown in Figure 9A, the multilayer material 800 for use as a thermal barrier in an electrical energy storage system comprises a core layer having a compressible pad 410 with a compressibility factor of about 1 MPa to about 12 MPa (e.g., 1.5 MPa, 2 MPa, 4 MPa, 5 MPa, 6 MPa, 8 MPa, 9 MPa, 10 MPa, 11 MPa, 11.5 MPa), and two insulating layers 470 and 480 having a thermal conductivity of less than about 50 mW / m·K at 25°C and less than about 60 mW / m·K at 600°C, through the thickness dimension of the insulating layers. The core layer is sandwiched between the two insulating layers 470 and 480, and the multilayer material is optionally encapsulated in an encapsulation material 420 selected from at least one of polymers, elastomers, or a combination thereof.

[0077] In the exemplary configuration of the multilayer material shown in Figure 9B, the multilayer material 810 for use as a thermal barrier in an electrical energy storage system includes a core layer comprising a compressible pad 410 having a compressibility coefficient of about 1 MPa to about 12 MPa, and two thermal conductive layers 530 and 540. The multilayer material 810 also has two of the above insulating layers 470 and 480 having thermal conductivity of less than about 50 mW / m·K at 25°C and less than about 60 mW / m·K at 600°C through the thickness dimension of the insulating layer, the core layer is sandwiched by the two insulating layers 470 and 480, and at least one thermal conductive layer has an in-plane thermal conductivity of at least about 200 mW / m·K, and the multilayer material is optionally encapsulated in an encapsulation material 420 selected from at least one of polymers, elastomers, or a combination thereof.

[0078] In the exemplary embodiment shown in Figure 9C, a multilayer material 820 for use as a thermal barrier in an electrical energy storage system includes a core layer comprising a compressible pad 410 having a compressibility coefficient of about 1 MPa to about 12 MPa, and two heat-capacitating layers 430 and 440. The core layer is sandwiched by two insulating layers 470 and 480 having thermal conductivity of less than about 50 mW / m·K at 25°C and less than about 60 mW / m·K at 600°C, through the thickness dimension of the insulating layers. The heat-capacitating layers have a specific heat capacity of at least about 200 J / (kg·K). The multilayer material is optionally encapsulated in an encapsulating material 420 selected from at least one of polymers, elastomers, or a combination thereof.

[0079] In the exemplary embodiment shown in Figure 9D, a multilayer material 830 for use as a thermal barrier in an electrical energy storage system includes a core layer having a compressible pad 410 with a compressibility coefficient of about 1 MPa to about 12 MPa and two heat-capacitance layers 430 and 440. Two insulating layers 470 and 480 sandwich the core layer, having a thermal conductivity of less than about 50 mW / m·K at 25°C and less than about 60 mW / m·K at 600°C through the thickness dimension of the insulating layers. The heat-capacitance layers have a specific heat capacity of at least about 200 J / (kg·K). The multilayer material 830 further includes two additional heat-capacitance layers 435 and 445 disposed on the outer surface of each insulating layer 470 and 480. The multilayer material is optionally encapsulated in an encapsulation material 420 selected from at least one of polymers, elastomers, or a combination thereof.

[0080] In the exemplary configuration of the multilayer material shown in Figure 9E, the multilayer material 840 for use as a thermal barrier in an electrical energy storage system includes a core layer comprising two compressible pads 410 and 460, each having a compressibility coefficient of about 1 MPa to about 12 MPa, and one heat-capacitating layer 430. Two insulating layers 470 and 480 sandwich the core layer, having a thermal conductivity of less than about 50 mW / m·K at 25°C and less than about 60 mW / m·K at 600°C through the thickness dimension of the insulating layer. The heat-capacitating layer has a specific heat capacity of at least about 200 J / (kg·K). The multilayer material is optionally encapsulated in an encapsulating material 420 selected from at least one of polymers, elastomers, or a combination thereof. The heat-capacitating layer 430 is sandwiched by the two compressible pads 410 and 460.

[0081] Insulation layer The insulating layers of multilayer materials described herein are involved in reliably controlling heat flow from heat-generating parts in small spaces, providing safety and prevention against fire propagation in such products in the fields of electronics, industrial technology, and automotive technology. Insulating layers with excellent compression properties may be useful in addressing these needs. In many embodiments of this disclosure, the insulating layer also functions as a flame / fire deflection layer, either by itself or in combination with other layers of the multilayer material. For example, an aerogel layer combined with an insulating layer, such as a layer of metal or mica, can provide protection for the underlying layer from flames and / or hot gases, as well as from flames / hot gases containing particulate materials, such as materials that may be pushed out of the LIB during a thermal runaway event. To give another example, the insulating layer itself may be resistant to flames and / or hot gases, as well as flames / hot gases containing particulate materials. Insulating layers such as mica, porous silica, and aerogel can function as flame / fire deflection layers in combination with a non-combustible layer. Insulating layers containing aerogel, such as the layers disclosed in the embodiments of this specification, are durable, easy to handle, have favorable resistance to heat and fire propagation while minimizing the thickness and weight of the materials used, and also possess favorable properties with respect to compressibility, compressive resilience, and compliance.

[0082] Aerogels are a class of porous materials with open cells, comprising an interconnected structure of a framework in which corresponding pores are integrated within the skeleton, and an interstitial phase within the pore network mainly composed of gases such as air. Aerogels are generally characterized by low density, high porosity, large surface area, and small pore diameter. Aerogels can be distinguished from other porous materials by their physical and structural properties.

[0083] Therefore, in some embodiments, the insulating layer of the multilayer material of the present disclosure includes an aerogel. In some embodiments, the insulating layer may further include a material selected from the group consisting of mica, porous silica, ceramic fibers, mineral wool, and combinations thereof. In some cases, the insulating layer lacks aerogel. In some embodiments, the insulating layer may include a material selected from the group consisting of mica, porous silica, ceramic fibers, mineral wool, and combinations thereof.

[0084] In certain embodiments, the insulating layer of the present disclosure has a thermal conductivity at 25°C, through the thickness dimension of the insulating layer, of about 50 mW / mK or less, about 40 mW / mK or less, about 30 mW / mK or less, about 25 mW / mK or less, about 20 mW / mK or less, about 18 mW / mK or less, about 16 mW / mK or less, about 14 mW / mK or less, about 12 mW / mK or less, about 10 mW / mK or less, about 5 mW / mK or less, or between any two of these values. In certain embodiments, the insulating layer of the present disclosure has a thermal conductivity at 600°C, through the thickness dimension of the insulating layer, of approximately 60 mW / mK or less, approximately 50 mW / mK or less, approximately 40 mW / mK or less, approximately 30 mW / mK or less, approximately 25 mW / mK or less, approximately 20 mW / mK or less, approximately 18 mW / mK or less, approximately 16 mW / mK or less, approximately 14 mW / mK or less, approximately 12 mW / mK or less, approximately 10 mW / mK or less, approximately 5 mW / mK or less, or between any two of these values.

[0085] The insulating layers of the present disclosure, for example, insulating layers including aerogel, can retain or increase a small amount of thermal conductivity (typically measured in units of mW / m·K) when subjected to a load of up to about 5 MPa. In certain embodiments, the insulating layers of the present disclosure have a thermal conductivity of about 50 mW / mK or less, about 40 mW / mK or less, about 30 mW / mK or less, about 25 mW / mK or less, about 20 mW / mK or less, about 18 mW / mK or less, about 16 mW / mK or less, about 14 mW / mK or less, about 12 mW / mK or less, about 10 mW / mK or less, about 5 mW / mK or less, or between any two of these values, through the thickness dimension of the insulating layer when subjected to a load of up to about 5 MPa. As a result of the load subjected to the aerogel insulating layer, the thickness of the aerogel insulating layer may decrease. For example, the thickness of an aerogel insulating layer can decrease by 50% or less, 40% or less, 30% or less, 25% or less, 20% or less, 15% or less, 10% or less, 5% or less, or any two of these values ​​when a load is applied in the range of approximately 0.50 MPa to 5 MPa. As the thickness decreases, the thermal resistance of the insulating layer containing aerogel may decrease, but the thermal conductivity can be retained or even increased by only a small amount.

[0086] In certain embodiments, the insulating layer of the Disclosure may have a heat of combustion of approximately 750 cal / g or less, approximately 717 cal / g or less, approximately 700 cal / g or less, approximately 650 cal / g or less, approximately 600 cal / g or less, approximately 575 cal / g or less, approximately 550 cal / g or less, approximately 500 cal / g or less, approximately 450 cal / g or less, approximately 400 cal / g or less, approximately 350 cal / g or less, approximately 300 cal / g or less, approximately 250 cal / g or less, approximately 200 cal / g or less, approximately 150 cal / g or less, approximately 100 cal / g or less, approximately 50 cal / g or less, approximately 25 cal / g or less, approximately 10 cal / g or less, or in the range between any two of these values. An insulating layer with improved heat of combustion compared to another insulating layer has a lower heat of combustion value compared to the reference insulating layer. In certain embodiments of the Disclosure, the HOC of the insulating layer is improved by mixing a fire-grade additive into the insulating layer.

[0087] In certain embodiments, the insulating layer of the present disclosure has an onset temperature of thermal decomposition at about 300 °C or higher, about 320 °C or higher, about 340 °C or higher, about 360 °C or higher, about 380 °C or higher, about 400 °C or higher, about 420 °C or higher, about 440 °C or higher, about 460 °C or higher, about 480 °C or higher, about 500 °C or higher, about 515 °C or higher, about 550 °C or higher, about 600 °C or higher, or in a range between any two of these values. In the context of this specification, for example, for a first composition having an onset temperature of thermal decomposition higher than that of a second composition, it would be contemplated that the first composition is improved over the second composition. When adding one or more fire rating additives, it is contemplated herein that the onset temperature of thermal decomposition of the composition or material increases compared to a composition that does not contain any fire rating additives.

[0088] The term "flexural modulus" or "modulus of flexural elasticity" is a measure of the material stiffness / resistance to bending when a force is applied perpendicular to the long edge of a sample known as a three-point bending test. The flexural modulus indicates the ability of a material to bend. The flexural modulus is represented by the slope of the initial straight portion of the stress-strain curve and is calculated by dividing the change in stress by the corresponding change in strain. Thus, the ratio of stress to strain is a measure of the flexural modulus. The international standard unit of flexural modulus is the pascal (Pa or N / m 2 or m -1 ·kg·s -2 ). The practical units used are megapascal (MPa or N / mm 2 ) or gigapascal (GPa or kN / mm 2 ). In US customary units, it is expressed as pounds (force) per square inch (psi). In certain embodiments, the insulating layer of the present disclosure has a flexural modulus of about 8 MPa or less, about 7 MPa or less, about 6 MPa or less, about 5 MPa or less, about 4 MPa or less, about 3 MPa or less. Preferably, the insulating layer of the present disclosure, such as an aerogel, has a flexural modulus of about 2 MPa to about 8 MPa.

[0089] As described above, the compressive and elastic properties of the materials between cells or between battery modules and battery packs are important for adapting to the expansion of cells during their lifecycle. In certain embodiments, the insulating layer, or multilayer material including the insulating layer, is (i) compressible to at least 50%, preferably at least 65%, most preferably at least 80%, of its original thickness or uncompressed thickness, and (ii) sufficiently resilient so that after compression for several seconds, the insulating layer returns to at least 70%, preferably at least 75%, most preferably at least 80%, of its original thickness or uncompressed thickness.

[0090] In certain embodiments, the compressibility coefficient of an insulating layer (e.g., a layer containing aerogel), a compressible component of a multilayer material including an insulating layer, or a multilayer material as a whole is in the range of about 1 MPa, about 2 MPa, about 3 MPa, about 4 MPa, about 5 MPa, about 6 MPa, about 7 MPa, about 8 MPa, about 9 MPa, about 10 MPa, about 11 MPa, about 12 MPa, or any two of these values.

[0091] aerogel The aerogel of the present invention may be organic, inorganic, or a mixture thereof. In some embodiments, the aerogel includes silica-based aerogels. The insulating layer of the multilayer material containing the aerogel further includes a reinforcing material. The reinforcing material may be any material that provides elasticity, adaptability, or structural stability to the aerogel material. Examples of well-known reinforcing materials, but not limited to, include open-cell macroporous skeletal reinforcing materials, closed-cell macroporous skeletal reinforcing materials, open-cell membranes, honeycomb reinforcing materials, polymer reinforcing materials, as well as fibrous reinforcing materials such as separate fibers, woven materials, nonwoven materials, needle-punched nonwovens, padding, webs, mats, and felts.

[0092] The reinforcing material can be selected from organic polymer fibers, inorganic fibers, carbon fibers, or a combination thereof. Inorganic fibers can be selected from glass fibers, rock fibers, metal fibers, boron fibers, ceramic fibers, basalt fibers, or a combination thereof.

[0093] In some embodiments, the reinforcing material may include a material having multiple layers. For example, the multiple layers of the material can be bonded together. In an exemplary embodiment, at least one of the multiple layers may include a first material, and at least one other layer of the multiple layers may include a second material. The first and second materials may have the same or different material properties. For example, the first material may be more compressible than the second material. Another example is that the first material may include closed cells, and the second material may include open cells.

[0094] Aerogels are typically described as a framework of interconnected structures consisting of interconnected oligomers, polymers, or colloidal particles. Aerogel frameworks can be made from a variety of precursor materials, including inorganic precursor materials (such as those used to produce silica-based aerogels), organic precursor materials (such as those used to produce carbon-based aerogels), hybrid inorganic / organic precursor materials, and combinations thereof. In the context of this disclosure, the term “amalgam aerogel” refers to an aerogel produced from a combination of two or more different gel precursors. The corresponding precursors are referred to as “amalgam precursors.”

[0095] Inorganic aerogel Inorganic aerogels are generally formed from metal oxide or metal alkoxide materials. These materials may be based on oxides or alkoxides of any metal capable of forming oxides. Such metals include, but are not limited to, silicon, aluminum, titanium, zirconium, hafnium, yttrium, vanadium, and cerium. Inorganic silica aerogels have traditionally been produced by hydrolysis and condensation of silica-based alkoxides (such as tetraethoxysilane) or by gelation of silicic acid or water glass. Other relevant inorganic precursor materials for silica-based aerogel synthesis include metal silicates, which include, but are not limited to, sodium silicate or potassium silicate, alkoxylanes, partially hydrolyzed alkoxylanes, tetraethoxysilane (TEOS), partially hydrolyzed TEOS, condensed polymers of TEOS, tetramethoxysilane (TMOS), partially hydrolyzed TMOS, condensed polymers of TMOS, tetra-n-propoxysilane, partially hydrolyzed polymers and / or condensed polymers of tetra-n-propoxysilane, polyethyl silicates, partially hydrolyzed polyethyl silicates, monomeric alkylalkoxysilanes, bistrialkoxyalkyl or arylsilanes, polyhedral silsesquioxanes, or combinations thereof.

[0096] In certain embodiments of this disclosure, a pre-hydrolyzed TEOS such as Silbond H-5 (SBH5, Silbond Corp) is hydrolyzed at a water / silica ratio of about 1.9 to 2, which can be used commercially or may be further hydrolyzed before being mixed into the gelling process. A partially hydrolyzed TEOS or TMOS such as polyethyl silicate (Silbond 40) or polymethyl silicate can also be used commercially or may be further hydrolyzed before being mixed into the gelling process.

[0097] Inorganic aerogels may also contain gel precursors comprising at least one hydrophobic group, such as alkyl metal alkoxides, cycloalkyl metal alkoxides, and aryl metal alkoxides, which can impart or improve certain gel properties such as stability and hydrophobicity. Inorganic silica aerogels may specifically contain hydrophobic precursors such as alkylsilanes or arylsilanes. Hydrophobic gel precursors can be used as primary precursor materials to form the backbone of gel materials. However, hydrophobic gel precursors are more commonly used as co-precursors in combination with simple metal alkoxides in the formation of amalgam aerogels. Hydrophobic inorganic precursor materials for silica-based aerogel synthesis include, but are not limited to, trimethylmethoxysilane (TMS), dimethyldimethoxysilane (DMS), methyltrimethoxysilane (MTMS), trimethylethoxysilane, dimethyldiethoxysilane (DMDS), methyltriethoxysilane (MTES), ethyltriethoxysilane (ETES), diethyldiethoxysilane, dimethyldiethoxysilane (DMDES), ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane (PhTES), hexamethyldisilazane, hexaethyldisilazane, and the like. Any derivative of any of the above precursors may be used, specifically, certain polymers of other chemical groups may be added to or crosslinked to one of the above precursors.

[0098] Furthermore, aerogels can be treated to impart or improve hydrophobicity. Hydrophobic treatment can be applied to sol-gel solutions, wet gels before liquid extraction, or aerogels following liquid extraction. Hydrophobic treatment is particularly common to products of metal oxide aerogels, such as silica aerogels. Examples of hydrophobic treatment of gels are described in more detail below, specifically in relation to treating silica wet gels. However, the specific examples and examples provided herein are not intended to limit the scope of this disclosure to any particular type of hydrophobic treatment or aerogel substrate. This disclosure includes any gel or aerogel known to those skilled in the art, and similarly may include related methods for hydrophobic treatment of aerogels, either in the case of wet gel formation or dry aerogel formation.

[0099] Hydrophobic treatment is carried out by reacting hydroxyl groups on the gel, such as silanol groups (Si-OH), present on the silica gel skeleton with the functional group of a hydrophobic agent. The resulting reaction converts the silanol groups and the hydrophobic agent into hydrophobic groups on the silica gel skeleton. Hydrophobic agent compounds can react with hydroxyl groups on the gel according to the following reaction: RNMX4-N (hydrophobic agent) + MOH (silanol) → MOMRN (hydrophobic group) + HX. Hydrophobic treatment can be performed both on the outer macrosurface of the silica gel and on the internal pore surfaces within the porous network structure of the gel.

[0100] The gel can be immersed in a mixture of a hydrophobic agent and an optional hydrophobic treatment solvent, which is suitable for the solubility of the hydrophobic agent and also miscible with the gel solvent of the wet gel. A wide range of hydrophobic treatment solvents can be used, including methanol, ethanol, isopropanol, xylene, toluene, benzene, dimethylformamide, and hexane. Alternatively, a liquid or gaseous hydrophobic agent can be brought into direct contact with the gel to impart hydrophobicity.

[0101] The hydrophobic treatment process may include mixing or stirring to help the hydrophobic agent penetrate the wet gel. The hydrophobic treatment process may also include changing other conditions such as temperature and pH, and further enhancing and optimizing the treatment reaction. After the reaction is complete, the wet gel is washed to remove unreacted compounds and by-products from the reaction.

[0102] Hydrophobic agents for hydrophobic treatment of aerogels are generally compounds of the following formula: RNMX4-N, where M is a metal, R is a hydrophobic group such as CH3, CH2CH3, C6H6, or a similar hydrophobic alkyl, cycloalkyl, or aryl moiety, and X is a halogen, usually Cl. Specific examples of hydrophobic agents, though not limited to them, include trimethylchlorosilane (TMCS), triethylchlorosilane (TECS), triphenylchlorosilane (TPCS), dimethylchlorosilane (DMCS), and dimethyldichlorosilane (DMDCS). Hydrophobic agents may also be of the following formula: Y(R3M)2, where M is a metal, Y is a crosslinking group such as NH or O, and R is a hydrophobic group such as CH3, CH2CH3, C6H6, or a similar hydrophobic alkyl, cycloalkyl, or aryl moiety. Specific examples of such hydrophobic agents include, but are not limited to, hexamethyldisilazane [HMDZ] and hexamethyldisiloxane [HMDSO]. Hydrophobic agents may further include the following compounds: RNMV4-N, where V is a reactive or leaving group other than a halogen. Specific examples of such hydrophobic agents include, but are not limited to, vinyltriethoxysilane and vinyltrimethoxysilane.

[0103] The hydrophobic treatment of the present disclosure may also be performed during the removal, replacement, or drying of the liquid from the gel. In specific embodiments, the hydrophobic treatment may be performed in a supercritical fluid environment (e.g., supercritical carbon dioxide, but not limited to) and may be combined with a drying or extraction step.

[0104] Organic aerogel Organic aerogels are generally formed from carbon-based polymer precursors. Such polymer materials include, but are not limited to, resorcinol formaldehyde (RF), polyimides, polyacrylates, polymethyl methacrylates, acrylate oligomers, polyoxyalkylenes, polyurethanes, polyphenols, polybutadianes, trialkoxysilyl-terminated polydimethylsiloxanes, polystyrenes, polyacrylonitriles, polyfurfural, melamine formaldehyde, cresol formaldehyde, phenol furfural, polyethers, polyols, polyisocyanates, polyhydroxybenzes, polyvinyl alcohol dialdehydes, polycyanurates, polyacrylamides, various epoxies, agars, chitosans, and combinations thereof. As an example, organic RF aerogels are generally made from sol-gel polymerization of resorcinol or melamine with formaldehyde in an alkaline state.

[0105] Organic / Inorganic Hybrid Aerogel Organic / inorganic hybrid aerogels primarily consist of organically modified silica ("ormosyl") aerogels. These ormosyl materials contain organic components covalently bonded to the silica network. Ormosyl is generally formed by the hydrolysis and condensation of organically modified silanes, R--Si(OX)3, using the conventional alkoxide precursor Y(OX)4. In these formulas, X can represent, for example, CH3, C2H5, C3H7, or C4H9; Y can represent, for example, Si, Ti, Zr, or Al; and R can be any organic fragment such as methyl, ethyl, propyl, butyl, isopropyl, methacrylate, acrylate, vinyl, or epoxide. The organic components of the ormosyl aerogel can also be dispersed throughout the silica network or chemically bonded to the silica network.

[0106] In certain embodiments, the aerogels of the Disclosure are preferably inorganic silica aerogels mainly formed from prepolymerized silica precursors such as oligomers, or hydrolyzed silicates formed from silicon alkoxides in an alcohol solvent. In certain embodiments, such prepolymerized silica precursors or hydrolyzed silicates may be formed in situ from other precursors or silicates such as alkoxysilanes or water glass. However, the Disclosure as a whole can be practiced using any other aerogel composition known to those skilled in the art, and is not limited to any one of the precursor materials or amalgam mixtures of the precursor materials.

[0107] Macropores As described above, an aerogel composition according to an embodiment of the present disclosure may include an aerogel framework containing macropores. Without being bound by any particular theory of operation, the presence of macropores in the aerogel framework may allow the aerogel composition, e.g., a reinforced aerogel composition, to be compressible, while simultaneously maintaining or further improving its thermal properties, e.g., reducing thermal conductivity. For example, macropores may be deformable, crushed, or otherwise reduced in size by compression of the composition, thereby allowing a reduction in the thickness of the composition when a load is applied. However, as macropores deform, they effectively become smaller pores. As a result, as macropores deform, the heat transfer pathways within the aerogel framework may become more meandering, thereby improving thermal properties, e.g., reducing thermal conductivity. In the context of the present disclosure, “mesopore” refers to a pore with an average pore diameter in the range of about 2 nm to about 50 nm. Aerogel frameworks are generally mesoporous (i.e., mainly containing pores with an average diameter in the range of about 2 nm to about 50 nm). In certain embodiments, the aerogel skeleton of the aerogel composition of the present disclosure may include macropores. In the context of the present disclosure, “macropore” refers to a pore with an average pore diameter greater than about 50 nm. The aerogel skeleton may include both macropores and mesopores. For example, at least 10% of the pore volume of the aerogel skeleton may consist of macropores, at least 5% of the pore volume of the aerogel skeleton may consist of macropores, at least 75% of the pore volume of the aerogel skeleton may consist of macropores, at least 95% of the pore volume of the aerogel skeleton may consist of macropores, or 100% of the pore volume of the aerogel skeleton may consist of macropores. In some particular embodiments, the aerogel skeleton may be a macroporous aerogel skeleton, so that the majority of its pore volume consists of macropores. In some cases, the macroporous aerogel skeleton may also include micropores and / or mesopores. In some embodiments, the average pore size (diameter) of the aerogel framework is greater than 50 nm and may be between 50 nm and 5000 nm, 250 nm and 2000 nm, 500 nm and 2000 nm, 500 nm and 1400 nm, or 1200 nm.In certain embodiments, the average pore diameter may be greater than 50 nm, and may range from 50 nm to 1000 nm, preferably from 100 nm to 800 nm, and more preferably from 250 nm to 750 nm.

[0108] Distribution of homogeneous and heterogeneous pore sizes

[0109] In some embodiments, variations in pore size within the aerogel framework can be homogeneously distributed throughout the aerogel framework. For example, the average pore size may be substantially the same across the entire aerogel framework.

[0110] In other embodiments, variations in pore size within the aerogel framework can be heterogeneously distributed throughout the aerogel framework. For example, the average pore size may differ in specific regions of the aerogel framework. In some exemplary embodiments, the average pore size may be larger in the upper surface, lower surface, or both upper and lower surfaces of the aerogel framework. For example, due to the distribution of macropores within the composition, the ratio of macropores to mesopores may be greater on the upper surface than on the lower surface, greater on the lower surface than on the upper surface, or greater on both the upper and lower surfaces than in the intermediate region between the upper and lower surfaces. Another example is that due to the distribution of macropores within the composition, the ratio of macropores to mesopores may be greater near the upper surface than near the lower surface, greater near the lower surface than near the upper surface, or greater near both the upper and lower surfaces than in the intermediate region between the upper and lower surfaces. In other embodiments, the average pore size may be larger in the intermediate region between the upper and lower surfaces of the aerogel framework.

[0111] Macropore formation Macropores can be formed during the production of an aerogel composition. For example, macropore formation can be induced in the gel precursor material during the transition to the gel composition. In some embodiments, macropore formation can be achieved, for example, by inducing spinodal decomposition of the gel precursor solution. Another example is that macropore formation can be induced by adding one or more foaming agents.

[0112] The resulting macropores in the aerogel framework can be formed by selecting processing conditions that are more favorable to macropore formation compared to mesopores and / or micropores. The amount of macropores can be adjusted by implementing one, any combination of, or all of the following variables. The variables are: (1) polymerization solvent, (2) polymerization temperature, (3) polymer molecular weight, (4) molecular weight distribution, (5) copolymer composition, (6) branching amount, (7) crosslinking amount, (8) branching method, (9) crosslinking method, (10) method used for gel formation, (11) type of catalyst used for gel formation, (12) chemical composition of catalyst used for gel formation, (13) amount of catalyst used for gel formation, (14) gel formation temperature, (15) type of gas flowing through the material during gel formation, (16) flow rate of gas flowing through the material during gel formation, (17) atmospheric pressure during gel formation, (18) removal of dissolved gases during gel formation, (19) presence of solid additives in the resin during gel formation, (20) time of the gel formation process, (21) substrate used for gel formation, (22) type of one or more solvents used in each step of the solvent exchange process, (23) type of one or more solvents used in each step of the solvent exchange process. (24) the time used in each step of the solvent exchange process, (25) the residence time of a portion in each step of the solvent exchange process, (26) the flow rate of the solvent in the solvent exchange, (27) the type of solvent flow in the solvent exchange, (28) the stirring rate of the solvent in the solvent exchange, (29) the temperature used in each step of the solvent exchange process, (30) the ratio of the volume of the solvent to the volume of a portion in the solvent exchange, (31) the drying method, (32) the temperature of each step in the drying process, (33) the pressure at each step of the drying process, (34) the composition of the gas used in each step of the drying process, (35) the velocity of the gas flow in each step of the drying process, (36) the temperature of the gas in each step of the drying process, (37) the temperature of a portion in each step of the drying process, (38) the presence of a housing around the portion in each step of the drying process, (39) the type of housing around the portion being dried, and / or (40) the solvent used in each step of the drying process.The polyfunctional amine and diamine compounds may be added separately or together as solids in one or more parts, and may be pure or soluble in a suitable solvent. In other embodiments, a method for preparing an aerogel may include (a) providing a polyfunctional amine compound and at least one diamine compound in a solvent to form a solution; (b) providing at least one dianhydride compound to the solution of step (a) in a manner sufficient to form a branched polymer matrix solution, wherein the branched polymer matrix is ​​solubilized in the solution; and (c) exposing the branched polymer matrix solution in a manner sufficient to form an aerogel having an open-cell structure. The macropores present in the resulting aerogel skeleton can be formed in the manner described above. In one preferred, non-limiting embodiment, the formation of macropores, compared to smaller mesopores and micropores, can be controlled primarily by controlling the polymer / solvent dynamics during gel formation.

[0113] As described above, an aerogel composition according to an embodiment of the present disclosure may include an aerogel skeleton and reinforcing materials, at least a portion of which does not contain aerogel. For example, the aerogel skeleton may extend partially through the thickness of the reinforcing material. In such embodiments, portions of the reinforcing material, such as OCMF, fibers, or a combination thereof, may include aerogel material, while portions may be aerogel-free. For example, in some embodiments, the aerogel extends through about 90% of the thickness of the reinforcing material, through a range of about 50% to about 90% of the thickness of the reinforcing material, through a range of about 10% to about 50% of the thickness of the reinforcing material, or through about 10% of the thickness of the reinforcing material.

[0114] Without being bound by any particular operating theory, an aerogel composition in which at least a portion of the reinforcing material does not contain aerogel can provide desirable properties of compressibility, compressive elasticity, and compliance. For example, the properties of the reinforcing material can be selected to provide sufficient reinforcement and support the thermal properties of the aerogel-containing region, and also to provide sufficient compressibility, compressive elasticity, and / or compliance in the aerogel-free region. The aerogel-containing portion of the reinforcing aerogel composition can provide a desired thermal conductivity, e.g., less than about 25 mW / m*K, while the aerogel-free reinforcing portion can provide or improve desired physical properties, e.g., a desired compressibility.

[0115] In some embodiments, a reinforcing aerogel composition in which at least a portion of the reinforcing material does not contain aerogel can be formed using the methods disclosed herein, in which the reinforcing material is combined with a precursor solution in an amount sufficient to partially fill the reinforcing material with the precursor solution. For example, the volume of the precursor may be less than the volume of the reinforcing material, so that the precursor extends only partially through the reinforcing portion. As described above, when dried, the resulting reinforcing aerogel composition contains an aerogel skeleton extending through an area smaller than the total thickness of the reinforcing material. In other embodiments, a reinforcing aerogel composition in which at least a portion of the reinforcing material does not contain aerogel can be formed by removing a surface aerogel layer from the reinforcing aerogel composition.

[0116] In some embodiments, a reinforcing aerogel composition in which at least a portion of the reinforcing material does not contain aerogel can be formed using a reinforcing material having properties that allow it to mix through the thickness of the reinforcing portion. For example, the reinforcing portion may comprise multiple layers, each having different properties, e.g., differences in average pore / cell size, material composition, closed-cell, open-cell, surface treatment, or a combination thereof. The multiple layers can be bonded together, for example, by using an adhesive, by frame bonding, or by other suitable methods or mechanisms, such as those described herein. Different properties of the reinforcing material can result in variations in the distribution of aerogel through the layers. For example, the open-cell portion of the reinforcing material may contain an aerogel skeleton, while the closed-cell portion may remain substantially aerogel-free. Similarly, other material properties of the reinforcing material or its layers can be used to determine the distribution of aerogel in the reinforcing portion, and consequently, the distribution in the reinforcing aerogel composition.

[0117] In some exemplary embodiments, a reinforcing aerogel composition in which at least a portion of the reinforcing material does not contain aerogel can be formed using the methods disclosed herein, and depending on the properties of the reinforcing material or the properties of the layers of the reinforcing material, the amount of precursor solution filling the material or layer is controlled or influenced, for example, during the coating process, to provide partial filling of the reinforcing material with the precursor solution. For example, one layer of the reinforcing material may have open cells and another layer of the reinforcing material may have closed cells. When the precursor solution is combined with such a reinforcing material, the gel precursor solution may penetrate the open cells of the layer while substantially not penetrating the closed cells of the other layer. When such a composition dries, the resulting reinforcing aerogel composition may include one portion that does not contain aerogel, e.g., a closed-cell layer, while the other portion, e.g., an open-cell layer, contains aerogel.

[0118] In some embodiments, the additives disclosed herein (e.g., endothermic additives, opacity additives, fire-resistant additives, or other additives) can be non-uniformly dispersed within the reinforced aerogel composition. For example, the additive material may vary through the thickness of the aerogel composition or along the length and / or width of the aerogel composition. For example, the additive can accumulate on one side of the aerogel composition. In some embodiments, the additive material(s) can be aggregated in one layer of the aerogel compound, or provided as separate layers consisting of additives essentially adjacent to or attached to the compound. For example, a thermal control member may essentially include a layer consisting of an endothermic material such as gypsum, sodium bicarbonate, or magnesia cement. In further exemplary embodiments, the aerogel composition may also include at least one layer of additional material, either within the composition or as a surface layer. For example, the layer may be selected from the group consisting of polymer sheets, metal sheets, fiber sheets, highly oriented graphite materials (e.g., pyrolytic graphite sheets), and fabric sheets. In some embodiments, the epidermal layer can be attached to the composition by an adhesive mechanism selected from, for example, aerosol adhesives, urethane adhesives, acrylate adhesives, hot melt adhesives, epoxy, rubber resin adhesives, polyurethane compound adhesives, and combinations thereof. In some embodiments, the epidermal layer can be attached to the composition by a non-adhesive mechanism, for example, by a mechanism selected from a group consisting of frame bonding, needling, stitching, seal bags, rivets, buttons, clamps, wraps, braces, and combinations thereof. In some embodiments, the epidermal layer can be attached to the composition using any combination of the aforementioned adhesive and non-adhesive mechanisms.

[0119] Powdered aerogel composition As described herein, aerogel compositions or compounds may include materials that admixture aerogel fine particles, particles, granules, beads, or powder with a binder such as an adhesive, a resin, cement, foam, polymer, or similar solid or solidifying material into a solid or semi-solid material. For example, an aerogel composition may include a reinforcing agent, aerogel particles, and optionally a binder. In exemplary embodiments, a slurry can be provided comprising aerogel particles and at least one type of wetting agent. For example, the aerogel particles can be coated or wetted with at least one wetting agent such as a surfactant or dispersant. The aerogel particles can be fully wetted, partially wetted (e.g., surface wetted), or present in the slurry. Preferred wetting agents are volatile and allow for proper restoration of the hydrophobicity of the hydrophobic aerogel particles. If the wetting agent remains on the surface of the aerogel particles, the remaining wetting agent may contribute to the overall thermal conductivity of the composite material. Therefore, preferred wetting agents are removable by decomposition or other means, or by volatilization without such means. In general, any wetting agent compatible with aerogel can be used.

[0120] Humectant Slurries or aerogels coated with wetting agents may be useful as a method for easily mixing hydrophobic aerogels with a variety of materials such as other water-containing fluids, slurries, adhesives, and binder materials, which can optionally be cured to form solid materials, fibers, metallic fibers, separate fibers, woven materials, nonwoven materials, needle-punched nonwovens, padding, webs, mats, felts, and combinations thereof. Aerogels wetted with at least one wetting agent, or slurries containing aerogels with at least one wetting agent, allow for easy introduction and uniform distribution of hydrophobic aerogels. Wet-laid processes, such as those described in U.S. Patent Nos. 9,399,864, 8,021,583, 7,635,411, and 5,399,422 (each of these patents is incorporated herein by reference as a whole), use aqueous slurries to disperse aerogel particles, fibers, and other additives. Next, the slurry can be dewatered to form layers of aerogel particles, fibers, and additives, which can then be dried and optionally calendered to produce an aerogel compound.

[0121] Aerogel particles and additives In other embodiments, the aerogel composition comprises aerogel particles, at least one inorganic matrix material, and optionally may also include fibers, auxiliary materials, additives, and further inorganic binders. In some embodiments, the inorganic matrix material may include phyllosilicates, such as naturally occurring phyllosilicates like kaolin, clay, or bentonite, synthetic phyllosilicates like magadite or kenyite, or mixtures thereof. The phyllosilicate may or may not be combustible, for example, by drying the material and removing the water of crystallization. In some embodiments, the inorganic matrix material may also include inorganic binders such as cement, lime, gypsum, or suitable mixtures thereof, combined with the phyllosilicate. In some embodiments, the inorganic matrix material may also include other inorganic additives such as fire-resistant additives, opacifiers, or combinations thereof disclosed herein. Aerogel compositions containing inorganic matrix materials and exemplary processes thereof are disclosed in U.S. Patent No. 6,143,400 and U.S. Patent No. 6,083,619 (each of those patents is incorporated herein by reference as a whole). In some embodiments, the aerogel composition may include aerogel particles coated onto or absorbed in woven materials, nonwoven materials, needle-punched nonwovens, padding, webs, mats, felts, and combinations thereof. Adhesive binders may be included in the composition. Additives such as fire-resistant additives, opacifiers, or combinations thereof, as disclosed herein, may also be included. Aerogel compositions coated onto or absorbed into fabrics and exemplary processes thereof are disclosed in U.S. Patent Publication No. 2019 / 0264381A1 (that patent is incorporated herein by reference as a whole).

[0122] As described herein, aerogel compounds can be laminated to or face other materials, such as reinforcing layers of surface materials. In one embodiment, the disclosure provides a multilayer laminate comprising at least one base layer containing a reinforcing aerogel composition and at least one skin layer. In one embodiment, the skin layer comprises a reinforcing material. In one embodiment, the reinforcing aerogel composition is reinforced with a fiber-reinforced layer or an open-cell foam-reinforced layer. In one embodiment, the disclosure provides a multilayer laminate comprising a base layer containing a reinforcing aerogel composition and at least two skin layers comprising reinforcing materials, the two skin layers being on opposite sides of the base layer. For example, multilayer aerogel laminate compounds can be produced according to the methods and materials described in U.S. Patent Application No. 2007 / 0173157.

[0123] The surface layer may include materials that help provide specific characteristics to the final synthetic structure, such as improved flexibility or reduced surface powdering. The surface material may be rigid or flexible. The surface material may include a conductive layer or reflective foil. For example, the surface material may include a metallic material or a metallized material. The surface material may include a nonwoven fabric material. The surface layer can be placed on the surface of the synthetic structure or on the surface of a reinforcing aerogel compound forming the synthetic structure, such as a thermal control member. The surface layer can form a continuous coating or bag around the synthetic structure or around a reinforcing aerogel compound forming the synthetic structure, such as a thermal control member. In some embodiments, one or more surface layers can encapsulate the synthetic structure or a reinforcing aerogel compound forming the synthetic structure.

[0124] In one embodiment, the surface layer comprises a polymer sheet surrounding the synthetic structure, more specifically, polymer materials including polyester, polyethylene, polyurethane, polypropylene, polyacrylonitrile, polyamide, aramid, more specifically, polymers such as polyethylene terephthalate, low-density polyethylene, ethylene-propylene copolymer, poly(4-methylpentane), polytetrafluoroethylene, poly(l-butene), polystyrene, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polyvinyl acrylonitrile, polymethyl methacrylate, polyoxymethylene, polyphenylene sulfone, cellulose triacetate, polycarbonate, polyethylene naphthalate, polycaprolactam, polyhexamethylene adipamide, polyundecanoamide, polyimide, or combinations thereof. In one embodiment, the polymer sheet comprises or essentially consists of a foamed polymer material, more specifically, a foamed polymer material including PTFE (ePTFE), foamed polypropylene (ePP), foamed polyethylene (ePE), foamed polystyrene (ePS), or a combination thereof. In one preferred embodiment, the face material essentially consists of a foamed polymer material. In one embodiment, the polymer sheet comprises or essentially consists of a microporous polymer material characterized by pore sizes ranging from 0.1 μm to 210 μm, 0.1 μm to 115 μm, 0.1 μm to 15 μm, or 0.1 μm to 0.6 μm.

[0125] In one embodiment, the surface layer material includes, or essentially consists of, a fluoropolymer material. In the context of this disclosure, the terms “fluoropolymer” or “fluoropolymer material” primarily refer to materials containing polymer fluorocarbons. Suitable fluoropolymer surface layer materials include, but are not limited to, polytetrafluoroethylene (PTFE), polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), perfluoroalkoxy (PFA), fluorinated ethylene propylene (FEP), polychlorotrifluoroethylene (PCTFE), ethylenetetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), ethylene chlorotrifluoroethylene (ECTFE), and combinations thereof, including, but not limited to, microporous PTFE as described in U.S. Patent No. 5,814,405 and foamed PTFE (ePTFE) such as Gore-Tex® (commercially available from WLGore). In one preferred embodiment, the surface material essentially consists of a fluoropolymer material. In one preferred embodiment, the surface material essentially consists of a foamed PTFE (ePTFE) material.

[0126] In one embodiment, the surface layer material includes or essentially consists of a non-fluoropolymer material. In the context of this disclosure, the terms “non-fluoropolymer” or “non-fluoropolymer material” refer to materials that do not contain fluoropolymer materials. Suitable non-fluoropolymer surface layer materials include, but are not limited to, aluminum vapor-deposited Mylar, low-density polyethylene such as Tyvek® (commercially available from DuPont), rubber or rubber compounds, nonwoven materials, elastic fibers such as spandex, nylon, Lycra, or elastane, and combinations thereof. In one embodiment, the surface material is a flexible surface material.

[0127] In some embodiments, the surface layer material may include automotive resins and polymers, such as materials having a maximum operating temperature of approximately 100°C, approximately 120°C, or approximately 150°C. For example, the surface layer material may include acrylonitrile butadiene styrene (ABS), polycarbonate ABS, polypropylene, polyurethane, polystyrene, polyethylene, polycarbonate, polyimide, polyamide, PVC, or combinations thereof. For example, aerogel compounds and thermal control members according to embodiments disclosed herein may include layers of automotive resin or automotive polymer, a metal layer or metallized layer, and an aerogel layer.

[0128] The surface layer can be attached to the substrate by using an adhesive suitable for fixing inorganic or organic surface materials to the substrate reinforcement. Examples of adhesives that can be used in this disclosure include, but are not limited to, cement-based adhesives, sodium silicate, latex, adhesives, silicone, polystyrene, aerosol adhesives, urethane, acrylic adhesives, hot-melt bonding systems, commercially available bonding systems from 3M, epoxy resins, rubber resin adhesives, and mixtures of polyurethane adhesives such as those described in U.S. Patent No. 4,532,316.

[0129] The surface layer can also be attached to the substrate by using an appropriate non-adhesive or technique to fix an inorganic or organic surface material to the substrate reinforcement. Examples of non-adhesive materials or techniques that can be used in this disclosure include, but are not limited to, heat fusion, ultrasonic stitching, RF sealing, stitching or threading, needling, sealing bags, rivets or buttons, clamps, wraps, or other non-adhesive lamination materials.

[0130] The epidermis can be attached to the substrate at any stage in the production of the aerogel composite material. In one embodiment, the epidermis is attached to the substrate after the sol-gel solution is injected into the base reinforcing material, but before gelation. In another embodiment, the epidermis is attached to the substrate after the sol-gel solution is injected into the base reinforcing material, and after subsequent gelation, but before the gel material degrades or dries. In yet another embodiment, the epidermis is attached to the substrate after the gel material has aged or dried. In a preferred embodiment, the epidermis is attached to the substrate before the sol-gel solution is injected into the base reinforcing material. The epidermis may be solid and impermeable to fluids. The epidermis may be porous and permeable to fluids. In a preferred embodiment, the epidermis is porous and permeable to fluids, containing pores or holes with a diameter large enough to allow the fluid to diffuse through the surface material. In another preferred embodiment, the epidermal layer is attached to the base reinforcement before the sol-gel solution is injected into the base reinforcement, and the epidermal layer is porous and includes pores or holes with a diameter large enough to allow fluid penetration and diffusion through the surface material. In yet another preferred embodiment, the epidermal layer is attached to an open-cell foam reinforcement before the sol-gel solution is injected into the foam reinforcement, and the epidermal layer is porous and includes pores or holes with a diameter large enough to allow fluid penetration and diffusion through the surface material.

[0131] milking agent The aerogel composition may contain an opacifying agent that reduces the radiative component of heat transfer. At any point before gel formation, the opaque compound or its precursor may be dispersed in a mixture containing the gel precursor. Examples of opaque compounds include, but are not limited to, boron carbide (B4C), diatomaceous earth, manganese ferrite, MnO, NiO, SnO, Ag2O, Bi2O3, carbon black, graphite, titanium dioxide, iron titanoxide, aluminum oxide, zirconium silicate, zirconium oxide, iron(II) oxide, iron(III) oxide, manganese dioxide, iron-titanium oxide (ilmenite), chromium oxide, carbides (SiC, TiC, or WC-1, etc.), or mixtures thereof. Examples of precursors of opaque compounds include, but are not limited to, TiOSO4 or TiOCl2. In some embodiments, silicon carbide hair crystals or fibers can be excluded from the opaque compounds used as additives. When an aerogel composition is intended for use in electrical devices, for example, as a barrier layer in batteries or for other related applications, a composition containing an opacifier can possess high dielectric strength with high capacitance and high surface resistivity as desired. In such embodiments, the carbon additive used as the opacifier may be nonconductive or may be modified to reduce electrical conductivity. For example, the opacifier can be surface-oxidized to reduce electrical conductivity. In some embodiments, carbon additives with inherent electrical conductivity can be used as opacifiers in aerogel compositions intended for use in electrical devices. In such embodiments, the conductive carbon additive can be used at concentrations below the penetration threshold to provide the composition with appropriate dielectric strength for use in electrical devices.

[0132] Fire-resistant additive The aerogel composition may contain one or more fire-resistant additives. In the context of this disclosure, the term “fire-resistant additive” refers to a material that, in relation to its reaction to fire, produces an endothermic effect and can be miscible into the aerogel composition. Furthermore, in certain embodiments, the fire-resistant additive has an endothermic decomposition (ED) onset temperature that is not greater than 100°C above the thermal decomposition (Td) onset temperature of the aerogel composition in which the fire-resistant additive is present, and in certain embodiments, has an ED onset temperature that is not less than 50°C below the Td of the aerogel composition in which the fire-resistant additive is present. In other words, the ED of the fire-resistant additive is (T d -50℃)~(T d It has a temperature range of +100℃.

number

[0133] Prior to, simultaneously with, or following miscion or mixing with a sol (e.g., silica sols formulated from alkyl silicate or water glass in various ways as understood in the prior art), the fire-resistant additive can be mixed with a medium containing ethanol and optionally up to 10% by volume of water, or otherwise dispersed in that medium. The mixture may be mixed and / or stirred as necessary to achieve substantially uniform dispersion of the additive in the medium. Without being bound by theory, additional endothermic effects can be obtained by utilizing the hydrated forms of the aforementioned clays and other fire-resistant additives. For example, halloysite clay (a product commercially available from Applied Minerals, Inc. under the trade name DRAGONITE, or simply Halloysite from Imerys) and kaolinite clay are aluminum silicate clays that, in their hydrated form, produce endothermic effects by releasing hydrated water upon heating (gas dilution). As another example, carbon in its hydrated form can release carbon dioxide at heating temperature or upon heating.

[0134] In the context of this disclosure, the term “heat of dehydration” means the amount of heat required to evaporate water from a material in a hydrated form (and, where applicable, for dihydroxylation) when not exposed to a heating. Heat of dehydration is generally expressed on a unit weight basis.

[0135] In certain embodiments, the fire-resistant additives of the Disclosure have a thermal decomposition onset temperature in the range of approximately 100°C or higher, approximately 130°C or higher, approximately 200°C or higher, approximately 230°C or higher, approximately 240°C or higher, approximately 330°C or higher, 350°C or higher, approximately 400°C or higher, approximately 415°C or higher, approximately 425°C or higher, approximately 450°C or higher, approximately 500°C or higher, approximately 550°C or higher, approximately 600°C or higher, approximately 650°C or higher, approximately 700°C or higher, approximately 750°C or higher, approximately 800°C or higher, or between any two of these values. In certain embodiments, the fire-resistant additives of the Disclosure have a thermal decomposition onset temperature of approximately 440°C or 570°C. In certain embodiments, the fire-resistant additive of the present disclosure has a thermal decomposition onset temperature that is not greater than approximately 50°C, not greater than approximately 40°C, not greater than approximately 30°C, not greater than approximately 20°C, not greater than approximately 10°C, not greater than approximately 5°C, or in a range between any two of these values, relative to the Td of the aerogel composition (without the fire-resistant additive) to which the fire-resistant additive is mixed.

[0136] The fire-resistant additives of this disclosure include, but are not limited to, the following clay materials: phyllosilicate clay (illite, etc.), kaolin or kaolinite (aluminum silicate; Al2Si2O5(OH)4), metakaolin, halloysite (aluminum silicate; Al2Si2O5(OH)4), endelite (aluminum silicate; Al2Si2O5(OH)4), mica (silica mineral), diaspore (aluminum hydroxide oxide; α-AlO(OH)), gibbsite (aluminum hydroxide oxide; γ-AlO(OH)), boehmite (aluminum hydroxide oxide; γ-AlO(OH)), montmorillonite, byderite, pyrophyllite (aluminum silicate; Al2Si4O 10Examples of carbon atoms include (OH)2), nontronite, brabiite, smectite, revalierite, rectolite, celadonite, attapulgite, chloroparl, volconcoreite, allofen, lacewinite, dillnite, severite, myrosite, corylite, simolite, newtonite, sodium bicarbonate (NaHCO3), magnesium hydroxide (or magnesium dihydrate, "MDH"), alumina trihydrate ("ATH"), gypsum (calcium sulfate dihydrate; CaSO4·2H2O), valintonite (MgCO3·2H2O), neskehonite (MgCO3·3H2O), lancefordite (MgCO3·5H2O), hydrated magnesium carbonate (Mg5(CO3)4(OH)2·4H2O), dolomite, and other carbon atoms such as lithium carbon, though not limited to these. In certain embodiments of this disclosure, a clay material having at least a partial layered structure is used among several clay materials. In certain embodiments of this disclosure, the clay material as a fire-resistant additive in the aerogel composition has at least some water, such as in a hydrated form. The additive may be in a hydrated crystalline form or may become hydrated during the manufacturing / processing of the composition of this disclosure. In certain embodiments, the fire-resistant additive also includes a low-melting-point additive that absorbs heat without changing its chemical composition. An example of this class is low-melting-point glass, such as inert glass beads. Other additives that may be useful in the composition of this disclosure include, but are not limited to, wollastonite (calcium silicate) and titanium dioxide (TiO2). In certain embodiments, other additives may include, but are not limited to, infrared opacifiers such as titanium dioxide or silicon carbide, but are not limited to, low-melting-point glass frit, ceramifiers such as calcium silicate, or char-forming agents such as phosphates and sulfates. In certain embodiments, the additive may require special treatment, such as techniques to ensure that the additive is uniformly distributed and does not aggregate in large quantities to alter product performance. Treatment techniques may include additional static and dynamic mixers, stabilizers, process state adjustments, and other techniques known in the art.

[0137] Amount of additives The amount of additives in the aerogel compositions disclosed herein may depend on the desired properties of the composition. The amount of additives used during the preparation and processing of sol-gel compositions is generally referred to as a weight percentage of the silica content of the sol. The amount of additives in the sol may vary by weight relative to the silica content from about 5 wt% to about 70 wt%. In certain embodiments, the amount of additives in the sol is 10 wt% to 60 wt% relative to the silica content, and in certain preferred embodiments, the amount is 20 wt% to 40 wt% relative to the silica content. In exemplary embodiments, the amount of additives in the sol relative to the silica content is in the range of about 5% to about 20%, about 10% to about 20%, about 10% to about 30%, about 10% to about 20%, about 30 wt% to about 50 wt%, about 35 wt% to about 45 wt%, or about 35 wt% to about 40 wt% relative to the silica content. In some embodiments, the amount of additive in the sol is at least about 10 wt% relative to the silica content, or about 10 wt% relative to the silica content. In some embodiments, the amount of additive is in the range of about 5 wt% to about 15 wt% relative to the silica content. In certain embodiments, there may be two or more types of additives. One or more fire-resistant additives may also be present in the final aerogel composition. In some preferred embodiments, including a fire-resistant aluminum silicate additive, the additive is present in the aerogel composition at about 60 to 70 wt% relative to the silica content. For example, in some preferred embodiments, including a fire-resistant aluminum silicate additive such as kaolin, or a combination of a fire-resistant aluminum silicate additive such as kaolin and alumina trihydrate ("ATH"), the total amount of additives present in the aerogel composition is about 30 to 40 wt% relative to the silica content. To give another example, in some preferred embodiments in which the additive contains silicon carbide, the total amount of the additive present in the aerogel composition is about 30-40 wt%, for example 35 wt%, relative to the silica content. To give another example, in some preferred embodiments in which the additive contains silicon carbide, the total amount of the additive present in the aerogel composition is about 5-15 wt%, for example 10 wt%, relative to the silica content.

[0138] When referring to the final reinforcing aerogel composition, the amount of additives is generally referred to as a weight percentage of the final reinforcing aerogel composition. The amount of additives in the final reinforcing aerogel composition can vary from about 1% to about 50%, about 1% to about 25%, or about 10% to about 25% relative to the weight of the reinforcing aerogel composition. In exemplary embodiments, the amount of additives in the final reinforcing aerogel composition ranges from about 10% to about 20% relative to the weight of the reinforcing aerogel composition. In exemplary embodiments, the amount of additives in the final reinforcing aerogel composition is within the range of about 1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, about 10%, about 11%, about 12%, about 13%, about 14%, about 15%, about 16%, about 17%, about 18%, about 19%, about 20%, or any of the aforementioned percentages, as a weight percentage of the composition. In certain embodiments, the amount of additives in the final reinforced aerogel composition is about 15% of the weight of the reinforced aerogel composition. In certain embodiments, the amount of additives in the final reinforced aerogel composition is about 13% of the weight of the reinforced aerogel composition. For example, in some preferred embodiments, which include additives such as silicon carbide, the total amount of additives present in the aerogel composition is about 10-20 wt%, for example, about 15 wt%, of the weight of the reinforced aerogel composition. To give another example, in some preferred embodiments, which include silicon carbide as an additive, the total amount of additives present in the aerogel composition is about 3-5 wt%, for example, about 4 wt%, of the weight of the reinforced aerogel composition.

[0139] Initiation temperature of thermal decomposition of fire-resistant additives In certain embodiments, fire-resistant additives can be classified or grouped based on their onset temperature of thermal decomposition. For example, fire-resistant additives can be classified or grouped as having onset temperatures of thermal decomposition below about 200°C, below about 400°C, or above about 400°C. For example, additives with onset temperatures of thermal decomposition below about 200°C include sodium bicarbonate (NaHCO3), Neskehonite (MgCO3·3H2O), and gypsum (calcium sulfate dihydrate; CaSO4·2H2O). Another example of additives with onset temperatures of thermal decomposition below about 400°C includes alumina trihydrate ("ATH"), magnesium hydrate (magnesium carbon hydrate; Mg5(CO3)4(OH)2·4H2O), and magnesium hydroxide (or magnesium dihydrate, "MDH"). To give another example, additives with a thermal decomposition onset temperature of less than approximately 400°C include halloysite (aluminum silicate; Al2Si2O5(OH)4), kaolin or kaolinite (aluminum silicate; Al2Si2O5(OH)4), boehmite (aluminum hydroxide oxide; γ-AlO(OH)), or high-temperature phase change materials (PCMs).

[0140] In certain embodiments of this disclosure, clay materials, such as aluminosilicate clays like halloysite or kaolinite, are dehydrated and, for example, metahaloysite or metakaolin, used as additives in the aerogel composition. Other additives that may be useful in the compositions of this disclosure include, but are not limited to, wollastonite (calcium silicate) and titanium dioxide (TiO2). In certain embodiments, other additives may include, but are not limited to, infrared opacifiers such as titanium dioxide or silicon carbide, but are not limited to, low-melting-point glass frit, ceramifiers such as calcium silicate, or char-forming agents such as phosphates and sulfates. In certain embodiments, the additives may require consideration of special treatments, such as techniques to ensure that the additives are uniformly distributed and do not aggregate in large quantities to alter product performance. Treatment techniques may include additional static and dynamic mixers, stabilizers, process state adjustments, and others known in the art. One or more fire-resistant additives may also be present in the final aerogel composition.

[0141] In certain exemplary embodiments, the inclusion of additives, such as aluminosilicate clay materials like halloysite or kaolin in the aerogel materials and compositions of the Disclosure, may result in improved high-temperature shrinkage properties. An exemplary high-temperature shrinkage test method is the "Standard Test Method for Linear Shrinkage of Preformed High-Temperature Thermal Insulation Subjected to Soaking Heat" (ASTM C356, ASTM International, West Conshohocken, PA). In such a test, a material called a "thermal soak" is exposed to a temperature greater than 1000°C for a period of up to 60 minutes. In certain exemplary embodiments, the aerogel materials or compositions of the Disclosure may have high-temperature shrinkage in the range of about 20% or less, about 15% or less, about 10% or less, about 6% or less, about 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, or any combination of linear shrinkage, width shrinkage, thickness shrinkage, or dimensional shrinkage.

[0142] In some exemplary embodiments, certain basic catalysts used to catalyze precursor reactions may produce trace levels of other alkali metals in the aerogel composition. Trace levels of alkali, e.g., sodium or potassium, of 100-500 ppm in aerogel materials can adversely affect high-temperature shrinkage and thermal durability. However, without being bound by any particular mechanism or theory, aluminosilicate clay materials such as halloysite or kaolin can sequester released alkali, e.g., sodium or potassium, thereby reducing or eliminating the effects of alkali on shrinkage and thermal durability. In specific embodiments of this disclosure, the aluminosilicate clay material is dehydrated, e.g., metahaloysite or metakaolin. For example, aerogel materials or compositions containing amounts of metakaolin or metahaloysite greater than about 0.5 wt% relative to the silica content can significantly reduce thermal shrinkage and thermal durability. In exemplary embodiments, the aerogel material or composition may contain an amount of metakaolin or metahaloysite ranging from about 0.5 wt% to about 3.0 wt% relative to the silica content.

[0143] Encapsulation layer or encapsulation material layer In some embodiments, the core portion of the multilayer material disclosed herein, or the multilayer material itself, may be encapsulated by an encapsulation layer. For example, the encapsulation layer may include one or more layers of material surrounding the multilayer material, and / or a coating of material surrounding the multilayer material, and / or the core portion of the multilayer material. For example, the encapsulation layer may include a thin film, a layer, an envelope, or a coating. The encapsulation member can be made from any material suitable for surrounding the synthetic structure, or the reinforcing aerogel composite forming the synthetic structure. For example, the encapsulation member can reduce or eliminate the generation of dust or particulate material falling from the synthetic structure. The encapsulation material layer can be selected from polymers, elastomers, or combinations thereof. Examples of suitable polymers such as polyethylene terephthalate (PET), polyethylene (PE), polyimide (PI), rubber, and nylon have very low thermal conductivity (less than 1 W / m), which has the effect of reducing the planar thermal conductivity throughout the system. In one embodiment, the encapsulation layer includes a polyethylene terephthalate layer.

[0144] The encapsulation layer may include at least one vent that allows air to flow in and out of the panel. The encapsulation member may include at least one filter that filters out particulate matter. In an exemplary embodiment, the encapsulation layer includes a vent that allows air to flow in and out of the panel, and a particulate filter located above the vent that keeps particulate matter within the encapsulation member. In another embodiment, the encapsulation layer includes an edge seal that includes at least one vent and at least one particulate filter. In a further embodiment, the encapsulation layer includes an edge seal that includes at least one vent and at least one particulate filter, the vent in the edge seal allowing air to flow in and out of the edge of the encapsulation member, and the filter captures and retains particulate matter in the airflow, preventing air pollution outside the encapsulation layer by particulate matter.

[0145] Thermal capacitance layer In exemplary embodiments, a multilayer material may include a material or layer of material that provides thermal capacitance (i.e., a heat-capacitating material), for example, a material having a specific heat capacity of at least about 0.2 J / (g·°C). In some embodiments, the material providing thermal capacitance has a specific heat capacity of at least about 0.5 J / (g·°C). For example, the heat-capacitating material may include metals such as aluminum, titanium, nickel, steel, iron, or combinations thereof. In some embodiments, a multilayer material may include a layer or coating of the thermal capacitance-providing material. In some embodiments, a multilayer material may include particles of the thermal capacitance-providing material within the layers of the multilayer material, for example, within the layers of an aerogel composition. In certain embodiments, a multilayer material may include at least one layer of the thermal capacitance-providing material placed adjacent to an aerogel composition. In certain embodiments, a multilayer material may include at least one layer of the thermal capacitance-providing material placed between at least two of a plurality of layers of an aerogel composition. In exemplary embodiments, a multilayer material may include both thermal conductive and heat-capacitating materials.

[0146] For example, a multilayer material may include materials that provide both thermal capacitance and thermal conductivity, such as metals such as aluminum, titanium, nickel, steel, iron, or combinations thereof. Another example is a multilayer material which may include one or more different materials or layers of materials, each providing either thermal capacitance, thermal conductivity, or a combination thereof, such as a layer containing a metal and a layer containing a thermally conductive polymer. Preferably, the thermally conductive layer has a melting temperature of at least 300°C, more preferably at least 600°C, even more preferably at least 1000°C, and even more preferably at least 1500°C.

[0147] In some embodiments, the thermal capacitance material can be selected from phase-change materials. Phase-change materials are suitable for a variety of applications in energy storage systems, and it can be recognized that the material should not only have relatively high thermal capacitance during the phase change, but also be relatively low-cost and self-contained, i.e., no seals or special containment are required over the operating temperature range of the device, e.g., a packaged battery module. Desirable additional properties for energy storage applications include high thermal conductivity to rapidly transfer heat away from heat-generating components and the ability to customize the temperature at which the phase change occurs.

[0148] In some embodiments, the heat-capacitating material has a thermal conductivity of at least about 200 mW / m·K along the in-plane dimensions.

[0149] heat conduction layer The thermal conductive layers disclosed herein have been found to exhibit a significantly increased ability to rapidly dissipate heat throughout the entire xy plane of a multilayer material, further improving durability under high thermal loads. Examples of high thermal conductive materials include carbon fiber, graphite, silicon carbide, and metals, the metals including, but not limited to, copper, stainless steel, aluminum, and combinations thereof.

[0150] In exemplary embodiments, the multilayer material may include a layer of thermal conductive material or material that provides thermal conductivity. The thermal conductive layer of the present disclosure helps to dissipate heat away from localized thermal loads inside a battery module or battery pack. For example, the thermal conductive layer may have a thermal conductivity of at least about 200 mW / m·K along its in-plane dimensions. The thermal conductive material may include at least one layer comprising a metal, carbon, a conductive polymer, or a combination thereof.

[0151] In some embodiments of the above-described model, the multilayer material may comprise one or more thermal conductive layers, i.e., the multilayer material has a thermal conductivity greater than 50 W / mK, more preferably greater than 100 W / mK, and even more preferably greater than 200 W / mK (all values ​​measured at 25°C). For example, the multilayer material may comprise at least one layer comprising a thermal conductive material, e.g., a layer comprising a metal, carbon, a thermal conductive polymer, or a combination thereof. When used in relation to these embodiments, the thermal conductive material refers to a material having a thermal conductivity greater than that of an insulating material, e.g., an aerogel composition. In certain embodiments, the thermal conductive material has a thermal conductivity at least about an order of magnitude greater than that of the aerogel composition. In some embodiments, the multilayer material may comprise multiple layers of the aerogel composition. In certain embodiments, the multilayer material may comprise at least one layer of conductive material positioned adjacent to the aerogel composition. In certain embodiments, the multilayer material may comprise at least one layer of conductive material positioned between at least two of the multiple layers of the aerogel composition. In some embodiments, the multilayer material may include particles of a conductive material disposed within the layers of the multilayer material, for example, within the layers of an aerogel composition.

[0152] To assist in heat distribution and removal, in at least one embodiment, the thermal conduction layer is coupled to a heat sink. It is recognized that, as there are various types and configurations of heat sinks, there are different techniques for coupling a heat sink to a thermal conduction layer, and that this disclosure is not limited to the use of any one type of heat sink / coupling technique. For example, at least one thermal conduction layer of a multilayer material disclosed herein can be in thermal communication with an element of a cooling system of a battery module or battery pack, such as a cooling plate or cooling channel of a cooling system. To give another example, at least one thermal conduction layer of a multilayer material disclosed herein can be in thermal communication with other elements of a battery pack, battery module or battery system that can function as a heat sink, such as the wall of a pack, module or system, or with other elements of the multilayer material placed between battery cells. As described in more detail herein, thermal communication between a thermal conduction layer of a multilayer material and a heat sink element in a battery system may enable the removal of excess heat from one or more cells adjacent to the multilayer material to the heat sink, thereby reducing, for example, the impact, severity, or propagation of thermal events that may generate excess heat.

[0153] Preferably, the thermal conductive layer has a melting temperature of at least 300°C, more preferably at least 600°C, even more preferably at least 1000°C, and even more preferably at least 1500°C.

[0154] The thickness of the thermal conductive layer can depend on the composition, the properties of other multilayer elements such as compression pads, the number of thermal conductions contained in the multilayer material, and various factors of the composition. Functionally speaking, the thermal conductive layer should be thick enough to provide the desired in-plane thermal conductivity.

[0155] In some embodiments, the thermal conductive material, for example, a pyrolytic graphite sheet (PGS), may have a thickness in the range of about 0.010 mm, 0.025 mm, 0.05 mm, 0.07 mm, 0.10 mm, or between any two of these values, and an in-plane thermal conductivity in the range of about 600 to about 1950 W / mK. In some embodiments, the thermal conductive material, for example, a metal plate, may have a thickness in the range of about 0.05 mm, about 0.07 mm, about 0.10 mm, about 0.20 mm, about 0.25 mm, about 0.30 mm, about 0.5 mm, about 0.75 mm, about 1 mm, about 1.5 mm, about 2 mm, about 3 mm, about 4 mm, about 5 mm, or between any two of these values.

[0156] In some embodiments, the thermal conductive material can be selected from phase-change materials.

[0157] In some embodiments, a thermal paste can be used between layers of a multilayer material to ensure uniform and consistent heat conduction between such layers. As used herein, thermal paste refers to a variety of materials also known as thermal compounds, thermal greases, thermal conductive materials (TIMs), thermal gels, thermal pastes, heat sink compounds, and heat sink pastes. For example, a layer of thermal paste can be placed between an aerogel composition and any of the other layers. Other layers include a single or multiple layers containing a thermal conductive or heat-capacitating material, a single or multiple skin layers, or an inclusion layer.

[0158] Sacrificial material layer In exemplary embodiments, a multilayer material may include a sacrificial material or a layer of sacrificial material. In the context of this disclosure, the terms “sacrificial material” or “sacrificial layer” refer to a material or layer that is intended to be sacrificed, or at least partially removed, in response to mechanical, thermal, chemical, and / or electromagnetic conditions the layer is subjected to. For example, a sacrificial material or sacrificial layer may decompose when exposed to high temperatures, such as temperatures that occur before or during a thermal runaway event in a battery. In some embodiments, the sacrificial material layer may be located on an external surface. For example, it may be located on the outer surface of the core portion of the multilayer material, or on the outer surface of the multilayer material, for example, on the outer surface of the multilayer material.

[0159] In exemplary embodiments, the sacrificial material or layer of the Disclosure may include a compressible pad having a compressibility coefficient in the range of about 1 MPa, about 2 MPa, about 3 MPa, about 4 MPa, about 5 MPa, about 6 MPa, about 7 MPa, about 8 MPa, about 9 MPa, about 10 MPa, about 11 MPa, about 12 MPa, or between any two of these values. The sacrificial material layer can be selected from the group consisting of siloxanes, polyolefins, polyurethanes, phenols, melamines, cellulose acetates, and polystyrenes. In some cases, the material layer is in the form of a foam. In some embodiments, the compressible pad or foam may wear down due to exposure to mechanical loads (such as repeated loading). In some embodiments, the compressible pad or foam decomposes after exposure to an unusual mechanical event, a chemical event, and / or a thermal event.

[0160] In some embodiments, the onset temperature of the chemical decomposition of the sacrificial material layer is in the range of approximately 200°C to approximately 400°C.

[0161] Suitable foams for use as compressible pads in the embodiments disclosed herein have a density of about 1.0 g / cc or less, about 0.90 g / cc or less, about about 0.80 g / cc or less, about 0.70 g / cc or less, about 0.60 g / cc or less, about 0.50 g / cc or less, about 0.40 g / cc or less, about 0.30 g / cc or less, about 0.20 g / cc or less, about 0.16 g / cc, about 0.10 g / cc or less, about 0.08 g / cc or less, or lower than the range between any two of these values, and / or have a void volume content of at least about 20 to about 99%, specifically about 30% or more, based on the total volume of the foam. In exemplary embodiments, the foam has a density of approximately 0.08 g / cc to approximately 0.50 g / cc, a compressive force deflection (CFD) of 25% at approximately 27 kPa to approximately 55 kPa, and a compressive force set to less than approximately 10%, specifically less than 5%, at approximately 70°C. The CFD is measured by calculating the kPa force required to compress the sample to 25% of its original thickness, according to ASTM D1056.

[0162] The polymer used in the foam can be selected from various types of thermoplastic resins, mixtures of thermoplastic resins, or thermosetting resins. Examples of usable thermoplastic resins include polyacetal, polyacrylic, styrene-acrylonitrile, polyolefin, acrylonitrile-butadiene-styrene, polycarbonate, polystyrene, polyethylene terephthalate, polybutylene terephthalate, polyamide (but not limited to nylon 6, nylon 6,6, nylon 6,10, nylon 6,12, nylon 11, or nylon 12), polyamide-imide, polyarylate, polyurethane, ethylene propylene rubber (EPR), polyarylsulfone, polyethersulfone, polyphenylene sulfide, polyvinyl chloride, polysulfone, polyetherimide, polytetrafluoroethylene, fluorinated ethylene propylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, polyether ketone, polyether ether ketone, polyether ketone ketone bodies, etc., or combinations including at least one of the aforementioned thermoplastic resins.

[0163] Examples of thermoplastic resin mixtures that can be used in polymer foams include acrylonitrile-butadiene-styrene / nylon, polycarbonate / acrylonitrile-butadiene-styrene, acrylonitrile-butadiene-styrene / polyvinyl chloride, polyphenylene ether / polystyrene, polyphenylene ether / nylon, polysulfone / acrylonitrile-butadiene-styrene, polycarbonate / thermoplastic urethane, polycarbonate / polyethylene terephthalate, polycarbonate / polybutylene terephthalate, thermoplastic elastomer alloy, polyethylene terephthalate / polybutylene terephthalate, styrene-maleic anhydride / acrylonitrile-butadiene-styrene, polyetheretherketone / polyethersulfone, styrene-butadiene rubber, polyethylene / nylon, polyethylene / polyacetal, ethylene propylene rubber (EPR), etc., or combinations containing at least one of the aforementioned mixtures.

[0164] Examples of polymer thermosetting resins that can be used in polymer foams include polyurethane, epoxy, phenol, polyester, polyamide, silicon, etc., or combinations containing at least one of the aforementioned thermosetting resins. Mixtures of thermosetting resins and mixtures of thermoplastic resins and thermosetting resins can be used.

[0165] multilayer material As described above, multilayer materials according to embodiments of this disclosure offer desirable properties with respect to compressibility, compressive resilience, and compliance. When used as a thermal insulator between cells in a battery module, an insulating sheet formed using an aerogel composition may provide resistance to compressive deformation that adapts to the expansion of cells due to degradation and expansion of the active material during the battery's charge / discharge cycle. During the initial assembly of the battery module, relatively low loads of less than 1 MPa are generally applied to the thermal insulator, e.g., the multilayer materials disclosed herein. During use, for example, when cells in a battery module expand or swell during charge / discharge cycles, loads of up to approximately 5 MPa may be applied to the multilayer materials disclosed herein.

[0166] In exemplary embodiments, the disclosure provides a multilayer material exhibiting a compressibility of less than 25% at about 25 kPa. Optionally, upon compression release, the multilayer material may be sufficiently resilient to return to at least about 80%, 75%, 65%, 60%, or 50% of its original thickness. In some embodiments, the multilayer material exhibits a compressibility of less than 25% in the range of about 25 kPa to about 35 kPa, preferably less than 50% at about 50 kPa. In some embodiments, the multilayer material exhibits a compressibility in the range of about 25% to about 50% at about 50 kPa. In exemplary embodiments, the multilayer material exhibits a compressibility of less than 80% at about 245 kPa, for example, less than 70% at about 235 kPa. In exemplary embodiments, the multilayer material exhibits a compressibility of less than 70% at about 345 kPa. The thermal conductivity of the multilayer material comprising a reinforcing aerogel composition is preferably maintained at less than about 25 mW / m*K when the multilayer material is compressed.

[0167] As described herein, multilayer materials may comprise multiple layers of material, such as insulating layers, thermal conductive layers, heat-capacitating layers, encapsulating material layers, abrasion-resistant layers, fire-resistant / flame-retardant layers, heat-reflective layers, compressible layers, such as compressible pads, sacrificial layers, or combinations thereof. The combination and configuration of layers in the multilayer material can be selected to obtain a desired combination of properties, such as compressibility, elasticity, thermal performance, fire reactivity, and other properties. In some embodiments, the multilayer material comprises at least one compressible pad positioned between at least two layers of a reinforcing aerogel composition. For example, the compressible pad may be a foam or other compressible material such as polyolefin, polyurethane, phenol, melamine, cellulose acetate, or polystyrene. In certain embodiments, the multilayer material may also comprise at least one thermal conductive or heat-capacitating layer and at least one of multiple layers of the reinforcing aerogel composition. The thermal conductive or heat-capacitating material can absorb and / or disperse heat within the multilayer material. In some embodiments, the multilayer material may further comprise a heat-reflective layer. For example, the heat reflective layer may include a metal foil or metal sheet.

[0168] In embodiments of multilayer materials comprising several layers, layers can be attached to other layers by bonding mechanisms selected from, for example, aerosol adhesives, urethane adhesives, acrylate adhesives, hot melt adhesives, epoxy, rubber resin adhesives, polyurethane compound adhesives, and combinations thereof. In some embodiments, layers can be attached by non-adhesive mechanisms, selected from, for example, frame bonding, needling, stitching, seal bags, rivets, buttons, clamps, wraps, braces, and combinations thereof. In some embodiments, multiple layers can be attached together using any combination of the aforementioned bonding and non-adhesive mechanisms.

[0169] Final product of multilayer material Multilayer materials according to embodiments of this disclosure can be formed into various end products. In the simplest configuration, the multilayer material may be in the form of a sheet. The sheet can be formed continuously or semi-continuously, for example as a rolled product, or sheets of desired size and shape can be cut from a larger sheet or otherwise formed. The sheet material can be used to form a thermal barrier between battery cells. In other configurations, the reinforcing aerogel composition can be formed into a pouch to contain, for example, pouch cells of a battery, or into a cylinder to contain cylindrical battery cells.

[0170] The multilayer materials of this disclosure can be molded into a variety of three-dimensional forms, including paneling, pipe preforms, half-shell preforms, elbows, joints, pouches, cylinders, and other shapes typically required for insulating material applications in industrial and commercial uses.

[0171] As used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly indicates otherwise. As used herein and in the appended claims, the term “or” generally includes “and / or” unless the context clearly indicates otherwise.

[0172] As used herein, “about” means “approximately” or “nearly” and, in relation to the stated number or range, means ±5% of the number. In some embodiments, the term “about” may include conventional rounding according to the significant figures of the number. In addition, the phrase “about “x” to “y”” includes “about “x” to about “y”.”

[0173] The terms “composition” and “compound” as used herein are to be used interchangeably.

[0174] The terms “compressible pad” and “compressible layer” as used herein are interchangeable.

[0175] In the context of this disclosure, the terms “aerogel,” “aerogel material,” or “aerogel matrix” refer to a gel, which comprises a skeleton of interconnected structures in which a corresponding network of interconnected pores is integrated within the framework, containing gases such as air as a dispersion gap medium, and the gel is characterized by the following physical and structural properties (properties according to nitrogen porosimetry tests) attributable to aerogels as follows: (a) average pore size in the range of approximately 2 nm to approximately 100 nm, (b) porosity of at least 80%, and (c) approximately 100 nm 2 Surface area of ​​ / g or more

[0176] Therefore, the aerogel materials of this disclosure include any aerogel or other open-cell type material that satisfies the elements defined in the preceding paragraph, otherwise including materials that can be classified as xerogels, cryogels, ambigels, microporous materials, etc.

[0177] Furthermore, aerogel materials may be characterized by additional physical properties including (d) a pore volume of about 2.0 mL / g or more, particularly about 3.0 mL / g or more, (e) a density of about 0.50 g / cc or less, particularly about 0.3 g / cc or less, and even more particularly about 0.25 g / cc or less, and (f) at least 50% of the total pore volume including pores having a pore diameter of 2 to 50 nm (however, as will be described in more detail below, the embodiments disclosed herein include aerogel skeletons and compositions including pores having a pore diameter greater than 50 nm). However, characterization of the compound as an aerogel material is not required to satisfy these additional properties.

[0178] In the context of this disclosure, the term “aerogel composition” refers to any composite material that includes an aerogel material as a component of the compound. Examples of aerogel compositions include, but are not limited to, fiber-reinforced aerogel compounds; aerogel compounds containing additive elements such as opacifiers; aerogel compounds reinforced by an open-cell macroporous skeleton; aerogel-polymer compounds; and composite materials in which aerogel fine particles, particles, granules, beads, or powders are mixed with a binder, resin, cement, foam, polymer, or similar solid material into a solid or semi-solid material. Aerogel compositions are generally obtained from the various gel materials disclosed herein after the removal of the solvent. Therefore, aerogel compositions may undergo further additional processing or treatment. Also, the various gel materials may undergo other additional processing or treatment known or useful in the art before undergoing solvent removal (or liquid extraction or liquid drying).

[0179] The aerogel compositions of this disclosure may include reinforced aerogel compositions. In the context of this disclosure, the term “reinforced aerogel composition” refers to an aerogel composition that includes a reinforcing phase within the aerogel material, the reinforcing phase not being part of the aerogel skeleton itself.

[0180] In the context of this disclosure, the term “fiber-reinforced aerogel composition” refers to a reinforced aerogel composition comprising a fiber reinforcement as a reinforcing phase. Examples of fiber reinforcements include, but are not limited to, separate fibers, woven materials, dry-laid nonwoven materials, wet-laid nonwoven materials, needle-punched nonwovens, padding, webs, mats, felts, and / or combinations thereof.

[0181] Fiber reinforcement can be selected from organic polymer fibers, inorganic fibers, carbon fibers, or combinations thereof. Fiber reinforcement may include a variety of materials, including, but are not limited to, polyester; polyolefin terephthalate; poly(ethylene) naphthalate; polycarbonate (e.g., rayon, nylon); cotton (e.g., DuPont Lycra); carbon (e.g., graphite); polyacrylonitrile (PAN); oxidized PAN, uncarbonized heat-treated PAN (e.g., SGL carbon); glass or fiberglass materials (S glass, 901 glass, 902 glass, 475 glass, E glass, etc.); silica fibers such as quartz (e.g., Saint-Gobain Quartzel); Q-felt (Johns Polyaramid fibers such as Manville, Saffil, Unifrax, and other silica fibers; Duravac (Carborundum), Kevlar, Nomex, Sontera (all from DuPont), Conex (Taijin); polyolefins such as Tyvek (DuPont), Dyneema (DSM), and Spectra (Honeywell); other polypropylene fibers such as Typer and Xavan (both from DuPont); fluoropolymers such as PTFE, which has trade names like Teflon (DuPont) and Goretex (WLGORE); and Nicalon (COI Examples include silicon carbide fibers (such as Ceramics Inc.); ceramic fibers (such as Nextel Inc., 3M Inc.); acrylic polymers; fibers such as wool, silk, hemp, leather, and suede; liquid crystal materials such as PBO-Zylon fibers (Tyobo Inc.), Vectan (Hoechst Inc.), and Cambrelle fibers (DuPont Inc.); polyurethane, polyamide, wood fibers, boron, aluminum, iron, stainless steel fibers, and other thermoplastics such as PEEK, PES, PEI, PEK, and PPS. Glass or fiberglass-based fiber reinforced materials can be manufactured using one or more techniques. In certain embodiments, it is preferable to produce these materials using carding and cross-wrapping or air-laid processes.In exemplary embodiments, carded and cross-wrapped glass or fiberglass-based fiber reinforcements offer certain advantages over airlaid materials. For example, carded and cross-wrapped glass or fiberglass-based fiber reinforcements can provide a consistent material thickness relative to a given base weight of the reinforcement. In certain additional embodiments, it is desirable to further needle the fiber reinforcement, as the fibers need to be woven in the z direction to enhance the mechanical and other properties of the final aerogel composition.

[0182] In the context of this disclosure, the term “thermal runaway” generally refers to a sudden, rapid increase in cell temperature and pressure due to various operating factors, and thermal runaway can further result in the propagation of excessive temperature throughout the entire module in question. Potential causes of thermal runaway in such systems may include, for example, cell defects and / or short circuits (both internal and external), overcharging, cell dielectric breakdown or rupture due to an accident event, and excessive ambient temperature (e.g., generally above 55°C). Under normal use, cells heat up as a result of internal resistance. Under normal power / current loads and ambient operating conditions, the temperature inside most Li-ions in a cell can be relatively easily controlled to remain within the range of 20°C to 55°C. However, under stressful conditions such as high power extraction at high cell / ambient temperatures, as well as defects in individual cells, localized heat generation can increase rapidly. In particular, above the critical temperature, exothermic chemical reactions within the cell are activated. Furthermore, generally, chemical heat generation causes a rapid increase in temperature. As a result, the heat generated is far greater than the available heat dissipation. Due to thermal runaway, the temperature of the cell's vents and internal components may exceed 200°C.

[0183] In the context of this disclosure, the term “Foam” refers to a material comprising a substantially homogeneous composition of interconnected polymer structures in which a corresponding network or collection of pores is integrated within the framework, and which is formed by the dispersion of a certain proportion of gas in the form of bubbles in a liquid or resin foam material, and which, as a result, is retained as pores when the foam material solidifies into a solid structure. Generally, foams can be made using a variety of processes. See, for example, U.S. Patents 6,147,134, 5,889,071, 6,187,831, and 5,229,429. Accordingly, the foam materials of this disclosure include any material that satisfies the elements defined in this paragraph, otherwise including compounds that can be classified as OCMF materials, macroporous materials, etc. The foams as defined in this disclosure may be of thermoplastic, elastomer, and thermosetting resin (duromer) types.

[0184] In the context of this disclosure, the terms “flexible” and “flexible” refer to the ability of a material or composition to bend or flex without macrostructural failure. The insulating layers of this disclosure are capable of bending at least 5°, at least 25°, at least 45°, at least 65°, or at least 85° without macroscopic failure, and / or have a bending radius of less than 4 feet, less than 2 feet, less than 1 foot, less than 6 inches, less than 3 inches, less than 2 inches, less than 1 inch, or less than U inches without macroscopic failure. Similarly, the terms “highly flexible” or “highly flexible” refer to a material capable of bending to at least 90° without macroscopic failure, and / or having a bending radius of less than U inches. Furthermore, the terms “classified flexibility” and “classified as flexible” refer to a material or composition that can be classified as flexible according to ASTM C1 101 (ASTM International, West Conshohocken, PA).

[0185] The insulating layers of this disclosure may be flexible, may be highly flexible, and / or may be classified as flexible. The aerogel compositions of this disclosure may also be drapeable. In the context of this disclosure, the terms “drapeable” and “drapeability” refer to the ability of a material to bend or flex by 90° or more with a radius of curvature of about 4 inches or less, without macroscopic failure. An insulating layer according to a particular embodiment of this disclosure may be flexible such that the composition is non-rigid, and the composition may be applied to and conform to a three-dimensional surface or object, or may be preformed into various shapes and configurations to simplify installation or application.

[0186] In the context of this disclosure, the terms “additive” or “additive element” refer to materials that may be added to an aerogel composition before, during, or after aerogel formation. Additives may alter or improve desirable properties of the aerogel, or weaken undesirable properties of the aerogel. Generally, additives are added to the aerogel material, either before gelation into a precursor liquid, during gelation into a transition state material, or after gelation into a solid or semi-solid material.

[0187] Examples of additives include, but are not limited to, microfibers, fillers, reinforcing agents, stabilizers, thickeners, elastic compounds, opacifiers, coloring compounds or pigment compounds, radiation-absorbing compounds, radiation-reflecting compounds, fire-resistant additives, corrosion inhibitors, thermal conductive components, thermal capacitance-providing components, phase change materials, pH adjusters, redox adjusters, HCN mitigators, off-gas mitigators, conductive compounds, dielectric compounds, magnetic compounds, radar-blocking components, curing agents, shrinkage inhibitors, and other aerogel additives known to those skilled in the art. In some embodiments, the thermal capacitance-providing component may include a material having a specific heat capacity of at least about 0.3 J / (g·C). In some embodiments, the thermal capacitance-providing material has a specific heat capacity of at least about 0.5 J / (g·C). For example, the thermal capacitance-providing material may include metals such as aluminum, titanium, nickel, steel, iron, or combinations thereof. In some embodiments, a multilayer material may include one or more layers or coatings of the thermal capacitance-providing material. In some embodiments, the multilayer material may include particles of a material that provides thermal capacitance, which are arranged within one or more insulating layers containing an aerogel composition.

[0188] In certain embodiments, the aerogel compositions, reinforced aerogel compositions, and multilayer materials disclosed herein can be used during high-temperature events, for example, to provide thermal protection during high-temperature events such as those disclosed herein. The high-temperature event is defined as lasting at least 2 seconds and lasting at least about 1 cm 2 Across the area, at least approximately 25 kW / m 2 at least approximately 30 kW / m 2 , at least approximately 35 kW / m 2 , or at least about 40 kW / m 2 It is characterized by a sustained heat flux of approximately 40 kW / m². 2The heat flux is correlated with the heat flux generated from a typical fire (Behavior of Charring Solids under Fire-Level Heat Fluxes; Milosavljevic, I., Suuberg, EM; NISTIR 5499; September 1994). In special cases, high-temperature events can last for at least 1 minute and at least about 10 cm. 2 The heat flux across the area is approximately 40 kW / m.

[0189] In the context of this disclosure, the terms “thermal conductivity” and “TC” refer to a measure of the ability of a material or composition to transfer heat between two surfaces on either side of a material or composition where there is a temperature difference between the two surfaces. Thermal conductivity is specifically measured as the thermal energy transferred per unit time and per unit surface area divided by the temperature difference. It is typically expressed in SI units as mW / m². * K (milliwatts / meter) *It is recorded as Kelvin. The thermal conductivity of a material can be determined by the following test methods known in the art. Test methods include, but are not limited to, Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus (ASTM C518, ASTM International, West Conshohocken, PA), Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus (ASTM C177, ASTM International, West Conshohocken,PA), Test Method for Steady-State Heat Transfer Properties of Pipe Insulation(ASTM C335,ASTM International,West Conshohocken,PA), Thin Heater Thermal Conductivity Test(ASTM C1114,ASTM International,West Conshohocken,PA), Standard Test Method for Thermal Transmission Properties of Thermally Conductive Electrical Insulation Materials(ASTM D5470,ASTM International,West Conshohocken,PA), Determination of thermal resistance by means of guarded hot plate and heat flow meter methods(EN 12667,British Standards Institution,This includes the United Kingdom, or Determination of steady-state thermal resistance and related properties - Guarded hot plate apparatus (ISO 8203, International Organization for Standardization, Switzerland). It should be understood that, unless expressly otherwise specified in the context of this disclosure, thermal conductivity measurements are obtained according to ASTM C518 (Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus) at ambient atmospheric pressure, a temperature of approximately 37.5°C, and under a compressive load of approximately 2 psi, by different methods that may yield different results depending on the circumstances. Measurements reported according to ASTM C518 generally correlate well with any measurements performed according to EN12667 with any relevant adjustments to the compressive load.

[0190] Furthermore, thermal conductivity measurements can be obtained at a temperature of approximately 10°C at atmospheric pressure under compression. Thermal conductivity measurements at 10°C are generally lower, typically 0.5–0.7 mW / mK, than the corresponding thermal conductivity measurements at 37.5°C. In certain embodiments, the insulating layer of the present disclosure has a thermal conductivity at 10°C in the range of approximately 40 mW / mK or less, approximately 30 mW / mK or less, approximately 25 mW / mK or less, approximately 20 mW / mK or less, approximately 18 mW / mK or less, approximately 16 mW / mK or less, approximately 14 mW / mK or less, approximately 12 mW / mK or less, approximately 10 mW / mK or less, approximately 5 mW / mK or less, or between any two of these values.

[0191] In the context of this disclosure, the term “density” refers to a measure of mass per unit volume of a material or composition. The term “density” generally refers to the apparent density of a material, and similarly, to the bulk density of a composition. Density is generally expressed in kg / m³. 3Alternatively, it may be recorded as g / cc. The density of a material or composition, for example, the density of an aerogel, may be determined by the following methods known in the art. These methods include, but are not limited to, Standard Test Method for Dimensions and Density of Preformed Block and Board-Type Thermal Insulation (ASTM C303, ASTM International, West Conshohocken, PA), Standard Test Methods for Thickness and Density of Blanket or Batt Thermal Insulations (ASTM C167, ASTM International, West Conshohocken, PA), Determination of the apparent density of preformed pipe insulation (EN 13470, British Standards Institution, United Kingdom), or Determination of the apparent density of preformed pipe insulation (ISO 18098, International Organization for Standardization, Switzerland). In the context of this disclosure, density measurements are obtained, unless otherwise specified, under a compressive force of 2 psi, in accordance with ASTM C167 (Standard Test Methods for Thickness and Density of Blanket or Batt Thermal Insulations) for thickness measurements, by different methods which may yield different results depending on the circumstances.In certain embodiments, the aerogel material or composition of the Disclosure has a density in the range of about 1.0 g / cc or less, about 0.90 g / cc or less, about 0.80 g / cc or less, about 0.70 g / cc or less, about 0.60 g / cc or less, about 0.50 g / cc or less, about 0.40 g / cc or less, about 0.30 g / cc or less, about 0.25 g / cc or less, about 0.20 g / cc or less, about 0.18 g / cc or less, about 0.16 g / cc or less, about 0.14 g / cc or less, about 0.12 g / cc or less, about 0.10 g / cc or less, about 0.05 g / cc or less, about 0.01 g / cc or less, or between any two of these values.

[0192] The hydrophobicity of an aerogel material or composition can be expressed in terms of water vapor absorption. In the context of this disclosure, the term “water vapor absorption” refers to a measure of the potential of an aerogel material or composition to absorb water vapor. Water vapor absorption can be expressed as the percentage (by weight) of water absorbed, or otherwise retained, by an aerogel material or composition when exposed to water vapor under specific measurement conditions. The water vapor absorption of an aerogel material or composition can be determined by methods known in the art. Known methods include, but are not limited to, the Standard Test Method for Determining the Water Vapor Sorption of Unfaced Mineral Fiber Insulation (ASTM C1104, ASTM International, West Conshohocken, PA), Thermal insulating products for building applications, and Determination of long-term water absorption by diffusion (EN 12088, British Standards Institution, United Kingdom). In the context of this disclosure, water vapor intake measurements are obtained, unless otherwise specified, at 49°C and 95% humidity for 24 hours (modified from 96 hours according to ASTM C1104) under ambient pressure, according to ASTM C1104 (Standard Test Method for Determining the Water Vapor Sorption of Unfaced Mineral Fiber Insulation). In certain embodiments, the aerogel materials or compositions of this disclosure may have water vapor intakes in the range of about 50 wt% or less, about 40 wt% or less, about 30 wt% or less, about 20 wt% or less, about 15 wt% or less, about 10 wt% or less, about 8 wt% or less, about 3 wt% or less, about 2 wt% or less, about 1 wt% or less, about 0.1 wt% or less, or between any two of these values.Aerogel materials or compositions that exhibit improved water vapor intake compared to other aerogel materials or compositions will have a lower water vapor intake / retention ratio compared to a standard aerogel material or composition.

[0193] The hydrophobicity of an aerogel material or composition can be expressed by measuring the equilibrium contact angle of a water droplet at the interface with the surface of the material. The aerogel materials or compositions of this disclosure may have water contact angles in the range of about 90° or more, about 120° or more, about 130° or more, about 140° or more, about 150° or more, about 160° or more, about 170° or more, about 175° or more, or between any two of these values.

[0194] In the context of this disclosure, the terms “heat of combustion,” “HOC,” and “ΔHC” refer to measured values ​​of the amount of thermal energy released by the combustion or exothermic decomposition of a material or composition. Heat of combustion is generally recorded in units of calories (cal / g) of thermal energy released per gram of aerogel material or composition, or in units of megajoules (MJ / kg) of thermal energy released per kilogram of material or composition. The heat of combustion of a material or composition can be determined by methods known in the art, including, but not limited to, Reaction to fire tests for products—Determination of the gross heat of combustion (calorific value) (EN ISO 1716, International Organization for Standardization, Switzerland; EN adopted). In the context of this disclosure, unless otherwise specified, measurements of heat of combustion are obtained in accordance with the EN ISO 1716 standard (Reaction to fire tests for products—Determination of the gross heat of combustion (calorific value)).

[0195] Within the context of this disclosure, all thermal analyses and related definitions refer to measurements taken under conditions where air is at ambient pressure, starting at 25°C and rising to a maximum of 1000°C at a rate of 20°C per minute. Therefore, when measuring and calculating the onset temperature of pyrolysis, the peak temperature of heat dissipation, the peak temperature of heat absorption, etc., it is necessary to consider (or re-perform) any change in any of these parameters.

[0196] In the context of this disclosure, the terms “onset temperature of pyrolysis” and “TD” refer to the lowest ambient temperature at which a rapid exothermic reaction from the decomposition of an organic material occurs in the material or composition. Thermogravimetric analysis (TGA) can be used to measure the onset temperature of pyrolysis of an organic material in a material or composition. The TGA curve of a material shows the weight loss (% mass) of the material as it is exposed to an increasing ambient temperature, and thus indicates pyrolysis. The onset temperature of pyrolysis of a material may correlate with the intersection of tangents to the following TGA curve: a straight line tangent to the baseline of the TGA curve, and a straight line tangent to the TGA curve at the point of maximum slope during a rapid exothermic decomposition event relating to the decomposition of an organic material. In the context of this disclosure, unless otherwise specified, measurements of the onset temperature of pyrolysis of an organic material are obtained using TGA analysis as provided in this paragraph.

[0197] Furthermore, differential scanning calorimetry (DSC) analysis can be used to measure the onset temperature of thermal decomposition of a material. The DSC curve of a material shows the thermal energy (mW / mg) released by the material as it is exposed to a gradual increase in ambient temperature. The onset temperature of thermal decomposition of a material may correlate with the point on the DSC curve where ΔmW / mg (change in thermal energy output) increases most significantly, and therefore the DSC curve indicates the amount of heat generated from the aerogel material. In the context of this disclosure, measurements of the onset temperature of thermal decomposition using DSC, TGA, or both are obtained using a temperature rise rate of 20°C / min, as further defined in the preceding paragraph, unless otherwise specifically stated. DSC and TGA each provide similar values ​​for this onset temperature of thermal decomposition, and multiple times, by performing the tests simultaneously, test results can be obtained from both DSC and TGA.

[0198] In the context of this disclosure, the terms “endothermic decomposition onset temperature” and “TED” refer to the measured ambient temperature at which an endothermic reaction from decomposition or dehydration occurs in the material or composition. Thermogravimetric analysis (TGA) may be used to measure the endothermic decomposition onset temperature in a material or composition. The TGA curve of a material shows the weight loss (% mass) of the material as it is exposed to an increase in ambient temperature. The onset temperature of thermal decomposition of a material may correlate with the intersection of tangents to the following TGA curve: a straight line tangent to the baseline of the TGA curve, and a straight line tangent to the TGA curve at the point of maximum slope during the period of rapid endothermic decomposition or dehydration of the material. In the context of this disclosure, measured values ​​of the endothermic decomposition onset temperature of a material or composition are obtained using TGA analysis as provided in this paragraph, unless otherwise specified.

[0199] In the context of this disclosure, the terms “furnace rise” and “ΔTR” refer to a measured difference between the maximum temperature (TMAX) of a material or composition under pyrolysis conditions and the reference temperature of that material or composition under pyrolysis conditions (usually the final temperature or TFIN). Furnace rise is generally recorded in units of Celsius or °C. The furnace rise of a material or composition may be determined by methods known in the art, including, but not limited to, Reaction to fire tests for building and transport products: Non-combustibility test (EN ISO 1182, International Organization for Standardization, Switzerland; EN adopted). In the context of this disclosure, unless otherwise specified, measured furnace rises are obtained under conditions equivalent to those of EN ISO 1182 (Reaction to fire tests for building and transport products: Non-combustibility test). In certain embodiments, the aerogel compositions of this disclosure may result in furnace temperature rises in the range of about 100°C or less, about 90°C or less, about 80°C or less, about 70°C or less, about 60°C or less, about 50°C or less, about 45°C or less, about 40°C or less, about 38°C or less, about 36°C or less, about 34°C or less, about 32°C or less, about 30°C or less, about 28°C or less, about 26°C or less, about 24°C or less, or between any two of these values. Within the range of the stability of the compositions at the increase in temperature, for example, a first composition having a lower furnace temperature rise than a second composition may be considered an improvement over the second composition. Herein, it is conceivable that adding one or more fire-resistant additives to a composition reduces the furnace temperature rise of the composition.

[0200] In the context of this disclosure, the terms “flame time” and “TFLAME” refer to measured values ​​of the duration of a flame of a material or composition under thermal decomposition conditions, where “duration of flame time” is the duration of the flame in any visible portion of the test sample lasting for 5 seconds or more. Flame times are generally recorded in seconds or minutes. The flame time of a material or composition may be determined by methods known in the art, including, but not limited to, Reaction to fire tests for building and transport products: Non-combustibility test (EN ISO 1182, International Organization for Standardization, Switzerland; EN adopted). In the context of this disclosure, unless otherwise specified, measured values ​​of flame time are obtained under conditions equivalent to those of EN ISO 1182 (Reaction to fire tests for building and transport products: Non-combustibility test). In certain embodiments, the aerogel compositions of this disclosure have a flame time in the range of about 30 seconds or less, about 25 seconds or less, about 20 seconds or less, about 15 seconds or less, about 10 seconds or less, about 5 seconds or less, about 2 seconds or less, or between any two of these values. In the context of this specification, for example, a first composition having a shorter flame time than a second composition may be considered an improvement over the second composition. This specification suggests that the flame time of a composition is shortened when one or more fire-resistant additives are added compared to a composition without any fire-resistant additives.

[0201] In the context of this disclosure, the terms “mass loss” and “ΔM” refer to measured amounts of material, composition, or compound lost or incinerated under thermal decomposition conditions. Mass loss is generally recorded in weight percent or wt%. The mass loss of material, composition, or compound may be determined by methods known in the art, including, but not limited to, Reaction to fire tests for building and transport products: Noncombustibility test (EN ISO 1182, International Organization for Standardization, Switzerland; EN adopted). In the context of this disclosure, unless otherwise specified, measured mass loss is obtained under conditions equivalent to those of EN ISO 1182 (Reaction to fire tests for building and transport products: Non-combustibility test). In certain embodiments, the insulating layer or aerogel composition of this disclosure may have a mass loss in the range of about 50% or less, about 40% or less, about 30% or less, about 28% or less, about 26% or less, about 24% or less, about 22% or less, about 20% or less, about 18% or less, about 16% or less, or between any two of these values. In the context of this specification, for example, a first composition having a mass loss smaller than that of a second composition may be considered an improvement over the second composition. It is conceivable herein that the mass loss of a composition will decrease when one or more fire-resistant additives are added compared to a composition without any fire-resistant additives.

[0202] In the context of this disclosure, the term “peak heat dissipation temperature” refers to a measured value of the ambient heat temperature at which the exothermic heat dissipation from decomposition is maximum. The peak heat dissipation temperature of a material or composition may be measured using TGA analysis, differential scanning calorimetry (DSC), or a combination thereof. DSC and TGA will each provide similar values ​​for the peak heat dissipation temperature. And, multiple times, by performing the tests simultaneously, results can be obtained from both DSC and TGA. In a typical DSC analysis, the heat flow is plotted against temperature, and the peak heat dissipation temperature is the temperature at which the highest peak of such a curve occurs. In the context of this disclosure, measured values ​​of the peak heat dissipation temperature of a material or composition are obtained using TGA analysis as provided in this paragraph, unless otherwise specified.

[0203] In relation to endothermic materials, the term “peak temperature of thermal absorption” refers to a measured value of the ambient heat temperature at which the endothermic thermal absorption from decomposition is maximum. The peak temperature of thermal absorption of a material or composition can be measured using TGA analysis, differential scanning calorimetry (DSC), or a combination thereof. In a typical DSC analysis, the heat flow is plotted against temperature, and the peak temperature of thermal absorption is the temperature at which the lowest peak in such a curve occurs. Within the context of this disclosure, measured values ​​of the peak temperature of thermal absorption of a material or composition are obtained using TGA analysis as provided in this paragraph, unless otherwise specified.

[0204] In the context of this disclosure, the terms “low flammability” and “low flammability” refer to materials or compositions that satisfy the following combination of properties: i) furnace temperature rise of 50°C or less, ii) flame time of 20 seconds or less, and iii) mass loss of 50 wt% or less. In the context of this disclosure, the terms “non-flammable” and “non-flammability” refer to materials or compositions that satisfy the following combination of properties: i) furnace temperature rise of 40°C or less, ii) flame time of 2 seconds or less, and iii) mass loss of 30 wt% or less. As described herein, it is conceivable that the flammability of a composition (e.g., a combination of furnace temperature rise, flame time, and mass loss) may be reduced depending on the inclusion of one or more fire-resistant additives.

[0205] In the context of this disclosure, the terms “low flammability” and “low flammability” refer to low-flammability materials or compositions having a total heat of combustion (HOC) of 3 MJ / kg or less. In the context of this disclosure, the terms “non-flammable” and “non-flammability” refer to non-flammable materials or compositions having a heat of combustion (HOC) of 2 MJ / kg or less. As described herein, it is conceivable that the HOC of a composition may decrease depending on the inclusion of one or more fire-resistant additives.

[0206] In the context of this disclosure, the term “hydrophobic-bonded silicon” refers to silicon atoms in a gel or aerogel skeleton containing at least one hydrophobic group covalently bonded to a silicon atom. Examples of hydrophobic-bonded silicon include, but are not limited to, silicon atoms of silica groups in a gel skeleton formed from a gel precursor containing at least one hydrophobic group (e.g., MTES or DMDS). Hydrophobic-bonded silicon may also include, but are not limited to, silicon atoms on a gel skeleton or gel surface treated with a hydrophobicizing agent (e.g., HMDZ) to impart or improve hydrophobicity by mixing additional hydrophobic groups into the composition. Hydrophobic groups in this disclosure include, but are not limited to, methyl groups, ethyl groups, propyl groups, isopropyl groups, butyl groups, isopropyl groups, tert-butyl groups, octyl groups, phenyl groups, or other substituted or unsubstituted hydrophobic organic groups known to those skilled in the art. In the context of this disclosure, the terms “hydrophobic group,” “hydrophobic organic material,” and “hydrophobic organic content” specifically exclude readily hydrolyzable organosilicon-bonded alkoxy groups on the gel material skeleton, which are reaction products of organic solvents and silanol groups. Such excluded groups can be distinguished from this hydrophobic organic content by NMR analysis. The amount of hydrophobic-bonded silicon encapsulated in aerogels can be analyzed using NMR spectroscopy, such as CP / MAS29Si Solid State NMR. NMR analysis of aerogels enables the characterization and related quantification of M-type hydrophobic-bonded silicon (monofunctional silica such as TMS derivatives), D-type hydrophobic-bonded silicon (bifunctional silica such as DMDS derivatives), T-type hydrophobic-bonded silicon (trifunctional silica such as MTES derivatives), and Q-type silicon (tetrafunctional silica such as TEOS derivatives). Furthermore, by using NMR analysis to categorize specific types of hydrophobic-bonded silicon into subtypes (such as categorizing T-type hydrophobic silicon into T1, T2, and T3 types), the bonding chemistry of hydrophobic silicon contained in aerogels can also be analyzed.Specific details regarding the NMR analysis of silica materials can be found in the paper "Applications of Solid-State NMR to the Study of Organic / Inorganic Multicomponent Materials" by Geppi et al. (Appl.Spec.Rev.(2008), 44-1:1-89), specifically on pages 7-9, which are incorporated herein by reference according to the specifically cited pages.

[0207] The characterization of hydrophobic bonded silicon by CP / MAS29SiNMR can be analyzed based on the following chemical shift peaks: Ml (30~10 ppm); DI (10~-10 ppm), D2 (-10~-20 ppm); T1 (-30~-40 ppm), T2 (-40~-50 ppm), T3 (-50~-70 ppm); Q2 (-70~-85 ppm), Q3 (-85~-95 ppm), Q4 (-95~-110 ppm). These chemical shift peaks are approximate and illustrative and are not intended to be limiting or restrictive. The exact chemical shift peaks resulting from various silicon species in the material may depend on the specific chemical composition of the material and can generally be deciphered by routine experiments and analyses by those skilled in the art.

[0208] In the context of this disclosure, the terms “hydrophobic organic content” or “hydrophobic substance content” or “hydrophobic content” refer to the amount of hydrophobic organic material bonded to the skeleton of an aerogel material or composition. The hydrophobic organic content of an aerogel material or composition can be expressed as a weight percentage of the amount of hydrophobic organic material on the aerogel skeleton compared to the total amount of material in the aerogel material or composition. The hydrophobic organic content can be calculated by those skilled in the art based on the properties of the materials used in producing the aerogel material or composition and the associated concentrations. Alternatively, the hydrophobic organic content can be measured using thermogravimetric analysis (TGA) of the material in question, preferably in an oxygen atmosphere (although TGA in alternative gas environments is also useful). Specifically, the proportion of hydrophobic organic material in an aerogel may correlate with the proportion of weight loss of the hydrophobic aerogel material or composition when exposed to combustion heat temperatures during TGA analysis, and adjustments are made during TGA analysis for water loss, loss of residual solvent, and loss of easily hydrolyzable alkoxy groups. The hydrophobic content of the aerogel compositions of this disclosure can be measured and determined using other alternative techniques, such as differential scanning calorimetry, elemental analysis (particularly carbon), chromatography, nuclear magnetic resonance spectroscopy, and other analytical techniques known to those skilled in the art. In some cases, a combination of known techniques may be useful or necessary in determining the hydrophobic content of the aerogel compositions of this disclosure.

[0209] The aerogel materials or compositions of this disclosure may have a hydrophobic organic content of 50 wt% or less, 40 wt% or less, 30 wt% or less, 25 wt% or less, 20 wt% or less, 15 wt% or less, 10 wt% or less, 8 wt% or less, 6 wt% or less, 5 wt% or less, 4 wt% or less, 3 wt% or less, 2 wt% or less, 1 wt% or less, or in a range between any two of these values.

[0210] The term "fuel content" refers to the total amount of combustible material in an aerogel material or composition, which may correlate with the total weight loss of the aerogel material or composition when exposed to combustion heat temperatures during TGA analysis or TG-DSC analysis, with adjustments made for water loss. The fuel content of an aerogel material or composition may include hydrophobic organic content, as well as other combustible residual alcohol solvents, fillers, reinforcing materials, and readily hydrolyzable alkoxy groups.

[0211] In the context of this disclosure, the term “Ormosyl” includes the aforementioned materials and also includes other organically modified materials, which may also be referred to as “Ormosera.” Ormosyl is often used as a coating on a substrate, for example, through a sol-gel process, in which the ormosyl film is applied. Other examples of organic-inorganic hybrid aerogels in this disclosure include, but are not limited to, silica-polyethers, silica-PMMA, silica-chitosan, carbides, nitrides, and other combinations of the aforementioned organic-inorganic aerogels that form compounds. Published U.S. Patent Application No. 20050192367 (paragraphs

[0022] –

[0038] and

[0044] –

[0058] ) contains teachings of such hybrid organic-inorganic materials, which are incorporated herein by reference according to the sections and paragraphs cited individually.

[0212] Use of multilayer materials inside battery modules or battery packs Lithium-ion batteries (LIBs) are considered one of the most important energy storage technologies due to their high operating voltage, low memory effect, and high energy density compared to conventional batteries. However, safety concerns present significant barriers to the large-scale use of LIBs. Under harsh conditions, the exothermic reaction can result in heat dissipation that may trigger subsequent dangerous reactions. The situation worsens when heat dissipation from a cell under harsh conditions can activate a chain reaction, leading to a sudden thermal runaway.

[0213] The continuous improvement in the energy density of lithium-ion batteries (LIBs) has made it increasingly urgent to enhance the safety of electrical devices, such as electric vehicles, in their development. The mechanisms behind safety issues vary depending on the different battery chemical reactions. This technology focuses on preparing multilayer materials and the corresponding configurations of these prepared materials in order to obtain desirable thermal and mechanical properties. The multilayer materials of this technology provide effective heat dissipation measures under normal conditions as well as under thermal runaway conditions, while ensuring the stability of the LIB under normal operating modes (e.g., withstanding applied compressive stress).

[0214] The multilayer materials disclosed herein are useful for isolating, insulating, and protecting battery cells or battery components of any configuration of battery, such as pouch cells, cylindrical cells, prism cells, and packs and modules incorporating or containing any such cells. The multilayer materials disclosed herein are useful in rechargeable batteries, such as lithium-ion batteries, solid-state batteries, and any other energy storage devices, or in technologies requiring isolation, insulation, and protection.

[0215] Passive devices such as cooling systems may be used in conjunction with the multilayer materials of this disclosure inside a battery module or battery pack.

[0216] The multilayer materials according to various embodiments of the present disclosure of battery packs include a single battery cell, or a plurality of such single battery cells, or a module of battery cells, for thermally isolating the battery cell modules from one another. Some embodiments of the present invention are shown below. [Embodiment 1] A multilayer material for use as a thermal barrier in an electrical energy storage system, wherein the multilayer material is A core portion comprising a layered assembly, wherein the layered assembly comprises at least one insulating layer and at least one heat-capacitating layer, An outer part located outside the core portion, the outer part comprising at least one sacrificial material layer, the sacrificial material layer comprising a compressible pad, and the outer part comprising, The multilayer material wherein the heat capacity layer has a specific heat capacity of at least about 200 J / (kg·K), and the insulating layer has a thermal conductivity of less than about 50 mW / m·K at 25°C and less than about 60 mW / m·K at 600°C, across the thickness dimension of the insulating layer. [Embodiment 2] A multilayer material for use as a thermal barrier in an electrical energy storage system, wherein the multilayer material is A core portion comprising a layered assembly, wherein the layered assembly comprises at least one insulating layer and at least one thermal conductive layer, An exterior disposed outside the core portion, the exterior comprising at least one sacrificial material layer, and the exterior includes, The multilayer material wherein the heat conductive layer has a thermal conductivity of at least about 200 mW / m·K along the in-plane dimensions of the heat conductive layer, and the insulating layer has a thermal conductivity of less than about 50 mW / m·K at 25°C and less than about 60 mW / m·K at 600°C along the thickness dimensions of the insulating layer. [Embodiment 3] The multilayer material according to Embodiments 1 and 2, further comprising a sealing material layer sandwiched between the core portion and the outer portion. [Embodiment 4] The multilayer material according to Embodiments 1 and 2, further comprising an encapsulation material layer, wherein the outer portion is sandwiched between the core portion and the encapsulation material layer. [Embodiment 5] The multilayer material according to any one of the prior embodiments, wherein the multilayer material has an average thickness between approximately 2 mm and approximately 10 mm in an uncompressed state. [Embodiment 6] The multilayer material according to any one of the prior embodiments, wherein the insulating layer comprises an aerogel. [Embodiment 7] The multilayer material according to embodiment 6, wherein the aerogel includes a reinforcing material. [Embodiment 8] The multilayer material according to Embodiment 7, wherein the reinforcing material includes fibers selected from organic polymer fibers, inorganic fibers, carbon fibers, or combinations thereof. [Embodiment 9] The multilayer material according to Embodiment 8, wherein the fibers are in the form of separate fibers, woven fabrics, dry-laid nonwoven fabrics, wet-laid nonwoven fabrics, needle-punched nonwoven fabrics, padding, webs, mats, felts, and / or combinations thereof. [Embodiment 10] The multilayer material according to Embodiment 8, wherein the inorganic fibers are selected from glass fibers, rock fibers, metal fibers, boron fibers, ceramic fibers, basalt fibers, or a combination thereof. [Embodiment 11] The multilayer material according to any one of Embodiments 6 to 10, wherein the aerogel includes a silica-based aerogel. [Embodiment 12] The multilayer material according to any one of embodiments 6 to 11, wherein the aerogel comprises one or more additives, and the one or more additives are present at a level of at least about 5 to 20 weight percent of the aerogel. [Embodiment 13] The multilayer material according to Embodiment 12, wherein one or more of the additives are present in the aerogel at a level of at least about 10 to 20 weight percent. [Embodiment 14] The multilayer material according to Embodiment 12, wherein one or more of the additives include a fire-resistant additive. [Embodiment 15] The multilayer material according to Embodiment 12, wherein one or more of the additives comprises an opacifying agent selected from B4C, diatomaceous earth, manganese ferrite, MnO, NiO, SnO, Ag2O, Bi2O3, TiC, WC, carbon black, titanium oxide, iron titanium oxide, zirconium silicate, zirconium oxide, iron(I) oxide, iron(III) oxide, manganese dioxide, iron titanium oxide (ilmenite), chromium oxide, or a mixture thereof. [Embodiment 16] The multilayer material according to Embodiment 12, wherein one or more of the additives include a silicon carbide-containing milking agent. [Embodiment 17] The multilayer material according to Embodiment 12, wherein the one or more additives include a combination of a fire-resistant additive and an opaque agent. [Embodiment 18] The multilayer material according to any one of Embodiments 6 to 17, wherein the aerogel has a density in the range of about 0.25 g / cc to about 1.0 g / cc. [Embodiment 19] The multilayer material according to any one of embodiments 6 to 18, wherein the aerogel has a flexural modulus of about 2 MPa to about 8 MPa. [Embodiment 20] The multilayer material according to any one of Embodiments 6 to 19, wherein the aerogel exhibits compressive resistance, and the compressive resistance at 25% strain is approximately 40 kPa to approximately 180 kPa. [Embodiment 21] The multilayer material according to any one of Embodiments 6 to 20, wherein the aerogel is in the form of a monolith, beads, particles, granules, powder, thin film, sheet, or a combination thereof. [Embodiment 22] A multilayer material according to any one of the prior embodiments, further comprising an encapsulation material layer, wherein the encapsulation material layer comprises a metal layer and one or more polymer layers, and the encapsulation layer is disposed between the core portion and the exterior. [Embodiment 23] The multilayer material according to any one of the prior embodiments, wherein the sacrificial material layer comprises a material selected from the group consisting of siloxane, polyolefin, polyurethane, phenol, melamine, cellulose acetate, and polystyrene. [Embodiment 24] The multilayer material according to any one of the prior embodiments, wherein the sacrificial material layer is in the form of a foam. [Embodiment 25] The multilayer material according to any one of the prior embodiments, wherein the starting temperature for the chemical decomposition of the sacrificial material layer is in the range of about 200°C to about 400°C. [Embodiment 26] The multilayer material according to any one of the prior embodiments, wherein the insulating layer further comprises a material selected from the group consisting of mica, porous silica, ceramic fibers, mineral wool, and combinations thereof. [Embodiment 27] The multilayer material according to any one of embodiments 2 to 26, wherein the thermal conductive layer comprises at least one layer comprising a metal, carbon, a conductive polymer, or a combination thereof. [Embodiment 28] The multilayer material according to any one of embodiments 2 to 26, wherein the thermal conductive layer includes a phase change material. [Embodiment 29] The multilayer material according to any one of embodiments 2 to 26, wherein the thermal conductive layer is a metal including aluminum, copper, or steel. [Embodiment 30] The multilayer material according to any one of embodiments 2 to 29, wherein the heat conductive layer conducts heat from a localized heat load. [Embodiment 31] The multilayer material according to embodiment 30, wherein the heat conductive layer releases heat from a localized heat load to the environment. [Embodiment 32] The multilayer material according to any one of embodiments 2 to 31, wherein the thermal conductive layer is a form selected from the group consisting of mesh, sheet, perforated sheet, foil, and perforated foil. [Embodiment 33] The multilayer material according to any one of Embodiments 1 and 3 to 26, wherein the heat capacity layer is a phase change material. [Embodiment 34] The multilayer material according to any one of the prior embodiments, wherein the exterior further includes a layer made of a material selected from a group of materials such as abrasion-resistant materials, expansive materials, flame-retardant materials, non-combustible materials, or combinations thereof. [Embodiment 35] The multilayer material according to any one of Embodiments 1 to 5 and Embodiments 22 to 34, wherein the insulating layer comprises a material selected from the group consisting of mica, porous silica, ceramic fibers, mineral wool, and combinations thereof. [Embodiment 36] The multilayer material according to any one of the prior embodiments, wherein the thermal conductivity at 25°C over the thickness dimension of the insulating layer remains the same or does not substantially increase under a load of up to approximately 5 MPa. [Embodiment 37] Use of a multilayer material according to any one of the prior embodiments for thermally separating the single cell cells or the battery cell modules in a battery pack comprising a plurality of single cell cells or a plurality of battery cell modules. [Embodiment 38] The use according to Embodiment 37, wherein a runaway event occurring in one or more battery cells or battery cell modules of a portion of the battery does not damage the battery cells or battery modules of the portion of the battery that is separated from the portion of the battery where the runaway event occurs by the multilayer material described in any one of Embodiments 1 to 36. [Embodiment 39] A first battery cell having a first surface, A second battery cell having a second surface, wherein the second surface faces the first surface, A multilayer material according to any one of embodiments 1 to 36 is disposed between the first surface and the second surface, A battery module, including... [Embodiment 40] The battery module according to Embodiment 39, wherein the multilayer material according to any one of Embodiments 1 to 36 covers at least about 80% of the surface area of ​​the opposing first and second surfaces. [Embodiment 41] It is a battery module, At least one battery cell, A multilayer material according to any one of Embodiments 1 to 36, wherein the multilayer material is disposed on the surface of at least one battery cell or on the surface of the battery module, The battery module, including the battery module. [Embodiment 42] The battery modules according to embodiments 39 and 41, further comprising a cooling system configured to remove heat from the battery pack. [Embodiment 43] The battery module according to embodiment 42, wherein at least one layer of the multilayer material is in thermal communication with the cooling system. [Embodiment 44] The battery module according to embodiment 43, wherein the heat conductive layer is in thermal communication with the cooling system. [Embodiment 45] A battery pack comprising a plurality of cells and spacers positioned between two adjacent cells or between two adjacent modules, wherein the spacers comprise a multilayer material as described in any one of embodiments 1 to 36. [Embodiment 46] The battery pack according to embodiment 45, further comprising a cooling system configured to remove heat from the battery pack. [Embodiment 47] The battery pack according to embodiment 46, wherein at least one layer of the multilayer material is in thermal communication with the cooling system. [Embodiment 48] The battery pack according to embodiment 47, wherein the heat conductive layer is in thermal communication with the cooling system. [Embodiment 49] A device or vehicle comprising a battery pack as described in any one of embodiments 45 to 48. [Embodiment 50] The device according to Embodiment 49, wherein the device is a laptop computer, PDA, mobile phone, tag scanner, audio device, video device, display panel, video camera, digital camera, desktop computer, military portable computer, military telephone, laser rangefinder, digital communication device, confidential information gathering sensor, electronically integrated clothing, night vision device, power tool, calculator, wireless, remote control device, GPS device, handheld television and portable television, car starter, flashlight, sound device, portable heating device, portable vacuum cleaner, or portable medical tool. [Embodiment 51] The vehicle according to embodiment 49, wherein the vehicle is an electric vehicle. [Embodiment 52] A multilayer material for use as a thermal barrier in an electrical energy storage system, wherein the multilayer material is A core layer comprising at least one compressible material layer having a compressibility coefficient of approximately 1 MPa to approximately 12 MPa, and at least one thermal conductive layer and / or at least one thermal capacity layer, The invention comprises two insulating layers having a thermal conductivity of less than approximately 50 mW / m·K at 25°C and less than approximately 60 mW / m·K at 600°C, through the thickness dimensions of the insulating layers. The core layer is sandwiched between the two insulating layers. The multilayer material is optionally encapsulated in an encapsulation material. [Embodiment 53] The multilayer material according to Embodiment 52, wherein the core layer further comprises a flame-retardant layer. [Embodiment 54] The multilayer material according to Embodiment 52, wherein the core layer includes at least one thermal conductive layer. [Embodiment 55] The multilayer material according to Embodiment 52, wherein the core layer includes at least one heat-capacitating layer. [Embodiment 56] The multilayer material according to Embodiment 52, wherein the core layer comprises two thermal conductive layers and one compressible material layer, and the compressible material layer is sandwiched between the two thermal conductive layers. [Embodiment 57] The multilayer material according to Embodiment 52, wherein the core layer comprises two heat-capacitating layers and one compressible material layer, and the compressible material layer is sandwiched between the two heat-capacitating layers. [Embodiment 58] The multilayer material according to Embodiment 52, wherein the core layer comprises one heat-capacitating layer and two compressible material layers, and the heat-capacitating layer is sandwiched between the two compressible material layers. [Embodiment 59] The multilayer material according to embodiment 52, wherein the multilayer material further comprises two heat-capacitating layers, each heat-capacitating layer being disposed on the outer surface of each insulating layer.

Claims

1. A multilayer material for use as a thermal barrier in an electrical energy storage system, wherein the multilayer material is A core portion comprising a layered assembly, wherein the layered assembly comprises at least one insulating layer and at least one heat-capacitating layer, An outer part located outside the core portion, the outer part comprising at least one sacrificial material layer, the sacrificial material layer comprising a compressible pad, and the outer part comprising, The multilayer material wherein the heat capacity layer has a specific heat capacity of at least about 200 J / (kg·K), and the insulating layer has a thermal conductivity of less than about 50 mW / m·K at 25°C and less than about 60 mW / m·K at 600°C, across the thickness dimension of the insulating layer.

2. A multilayer material for use as a thermal barrier in an electrical energy storage system, wherein the multilayer material is A core portion comprising a layered assembly, wherein the layered assembly comprises at least one insulating layer and at least one thermal conductive layer, An exterior disposed outside the core portion, the exterior comprising at least one sacrificial material layer, and the exterior includes, The multilayer material wherein the heat conductive layer has a thermal conductivity of at least about 200 mW / m·K along the in-plane dimensions of the heat conductive layer, and the insulating layer has a thermal conductivity of less than about 50 mW / m·K at 25°C and less than about 60 mW / m·K at 600°C along the thickness dimensions of the insulating layer.

3. The multilayer material according to claim 1, further comprising a encapsulation material layer sandwiched between the core portion and the outer portion.

4. The multilayer material according to claim 1, further comprising an encapsulation material layer, wherein the outer portion is sandwiched between the core portion and the encapsulation material layer.

5. The multilayer material according to claim 1, wherein the multilayer material has an average thickness between approximately 2 mm and approximately 10 mm in an uncompressed state.

6. The multilayer material according to claim 1, wherein the insulating layer includes aerogel.

7. The multilayer material according to claim 6, wherein the aerogel includes a reinforcing material.

8. The multilayer material according to claim 7, wherein the reinforcing material includes fibers selected from organic polymer fibers, inorganic fibers, carbon fibers, or combinations thereof.

9. The multilayer material according to claim 8, wherein the fibers are in the form of separate fibers, woven fabrics, dry-laid nonwoven fabrics, wet-laid nonwoven fabrics, needle-punched nonwoven fabrics, padding, webs, mats, felts, and / or combinations thereof.

10. The multilayer material according to claim 8, wherein the inorganic fibers are selected from glass fibers, rock fibers, metal fibers, boron fibers, ceramic fibers, basalt fibers, or a combination thereof.

11. The multilayer material according to claim 6, wherein the aerogel includes a silica-based aerogel.

12. The multilayer material according to claim 6, wherein the aerogel comprises one or more additives, and the one or more additives are present in at least about 5 to 20 weight percent of the aerogel.

13. The multilayer material according to claim 12, wherein one or more of the additives are present in the aerogel at a level of at least about 10 to 20 weight percent.

14. The multilayer material according to claim 12, wherein one or more of the additives include a fire-resistant additive.

15. The one or more additives mentioned above, B ４ C, diatomaceous earth, manganese ferrite, MnO, NiO, SnO, Ag ２ O, Bi ２ O ３ The multilayer material according to claim 12, comprising an opacifying agent selected from TiC, WC, carbon black, titanium oxide, iron titanium oxide, zirconium silicate, zirconium oxide, iron(I) oxide, iron(III) oxide, manganese dioxide, iron titanium oxide (ilmenite), chromium oxide, or mixtures thereof.

16. The multilayer material according to claim 12, wherein one or more of the additives include a milky agent containing silicon carbide.

17. The multilayer material according to claim 12, wherein the one or more additives include a combination of a fire-resistant additive and an opaque agent.

18. The multilayer material according to claim 6, wherein the aerogel has a density in the range of about 0.25 g / cc to about 1.0 g / cc.

19. The multilayer material according to claim 6, wherein the aerogel has a flexural modulus of about 2 MPa to about 8 MPa.

20. The multilayer material according to claim 6, wherein the aerogel exhibits compressive resistance, and the compressive resistance at 25% strain is approximately 40 kPa to approximately 180 kPa.

21. The multilayer material according to claim 6, wherein the aerogel is in the form of a monolith, beads, particles, granules, powder, thin film, sheet, or a combination thereof.

22. The multilayer material according to claim 1, further comprising an encapsulation material layer, wherein the encapsulation material layer comprises a metal layer and one or more polymer layers, and the encapsulation material layer is disposed between the core portion and the exterior.

23. The multilayer material according to claim 1, wherein the sacrificial material layer comprises a material selected from the group consisting of siloxane, polyolefin, polyurethane, phenol, melamine, cellulose acetate, and polystyrene.

24. The multilayer material according to claim 1, wherein the sacrificial material layer is in the form of a foam.

25. The multilayer material according to claim 1, wherein the starting temperature for the chemical decomposition of the sacrificial material layer is in the range of about 200°C to about 400°C.

26. The multilayer material according to claim 1, wherein the insulating layer further comprises a material selected from the group consisting of mica, porous silica, ceramic fibers, mineral wool, and combinations thereof.

27. The multilayer material according to claim 2, wherein the thermal conductive layer comprises at least one layer comprising a metal, carbon, a conductive polymer, or a combination thereof.

28. The multilayer material according to claim 2, wherein the thermal conductive layer includes a phase change material.

29. The multilayer material according to claim 2, wherein the heat conductive layer is a metal including aluminum, copper, or steel.

30. The multilayer material according to claim 2, wherein the heat conductive layer conducts heat from a localized heat load.

31. The multilayer material according to claim 30, wherein the heat conductive layer releases heat from a localized heat load to the environment.

32. The multilayer material according to claim 2, wherein the heat conductive layer is a form selected from the group consisting of mesh, sheet, perforated sheet, foil, and perforated foil.

33. The multilayer material according to claim 1, wherein the heat capacity layer is a phase change material.

34. The multilayer material according to claim 1, wherein the exterior further comprises a layer made of a material selected from a group of materials including abrasion-resistant materials, expansive materials, flame-retardant materials, non-combustible materials, or combinations thereof.

35. The multilayer material according to claim 1, wherein the insulating layer comprises a material selected from the group consisting of mica, porous silica, ceramic fibers, mineral wool, and combinations thereof.

36. The multilayer material according to claim 1, wherein the thermal conductivity at 25°C over the thickness dimension of the insulating layer remains the same or does not substantially increase under a load of up to approximately 5 MPa.

37. Use of a multilayer material according to any one of claims 1 to 36 for thermally separating the single cell cells or the battery cell modules in a battery pack comprising a plurality of single cell cells or a plurality of battery cell modules.

38. The use according to claim 37, wherein a runaway event occurring in one or more battery cells or battery cell modules in a portion of the battery pack does not damage the battery cells or battery modules in the portion of the battery pack that is separated from the portion of the battery pack where the runaway event occurs by the multilayer material.

39. A first battery cell having a first surface, A second battery cell having a second surface, wherein the second surface faces the first surface, A multilayer material according to any one of claims 1 to 36, disposed between the first surface and the second surface, A battery module, including...

40. The battery module according to claim 39, wherein the multilayer material covers at least about 80% of the surface area of ​​the opposing first and second surfaces.

41. It is a battery module, At least one battery cell, A multilayer material according to any one of claims 1 to 36, wherein the multilayer material is disposed on the surface of at least one battery cell or on the surface of the battery module, The battery module, including the battery module.

42. The battery module according to claim 39, further comprising a cooling system configured to remove heat from the battery module.

43. The battery module according to claim 41, further comprising a cooling system configured to remove heat from the battery module.

44. The battery module according to claim 42, wherein at least one layer of the multilayer material is in thermal communication with the cooling system.

45. The battery module according to claim 43, wherein at least one layer of the multilayer material is in thermal communication with the cooling system.

46. A battery module according to claim 39, in which claim 39 is a reference to any one of claims 2 and 27 to 32, wherein the battery module further comprises a cooling system configured to remove heat from the battery module, wherein at least one layer of the multilayer material is in thermal communication with the cooling system, and the thermal conductive layer is in thermal communication with the cooling system.

47. A battery module according to claim 41, in which claim 41 is a reference to any one of claims 2 and 27 to 32, wherein the battery module further comprises a cooling system configured to remove heat from the battery module, wherein at least one layer of the multilayer material is in thermal communication with the cooling system, and the thermal conductive layer is in thermal communication with the cooling system.

48. A battery pack comprising a plurality of cells and spacers positioned between two adjacent cells or between two adjacent modules, wherein the spacers comprise a multilayer material as described in any one of claims 1 to 36.

49. The battery pack according to claim 48, further comprising a cooling system configured to remove heat from the battery pack.

50. The battery pack according to claim 49, wherein at least one layer of the multilayer material is in thermal communication with the cooling system.

51. A battery pack according to claim 48, in which claim 48 refers to any one of claims 2 and 27 to 32, wherein the battery pack further comprises a cooling system configured to remove heat from the battery pack, wherein at least one layer of the multilayer material is in thermal communication with the cooling system, and the thermal conductive layer is in thermal communication with the cooling system.

52. A device or vehicle comprising the battery pack described in claim 45.

53. The device according to claim 52, wherein the device is a laptop computer, PDA, mobile phone, tag scanner, audio device, video device, display panel, video camera, digital camera, desktop computer, military portable computer, military telephone, laser rangefinder, digital communication device, confidential information gathering sensor, electronically integrated clothing, night vision device, power tool, calculator, wireless, remote control device, GPS device, handheld television and portable television, car starter, flashlight, sound device, portable heating device, portable vacuum cleaner, or portable medical tool.

54. The vehicle according to claim 52, wherein the vehicle is an electric vehicle.

55. A multilayer material for use as a thermal barrier in an electrical energy storage system, wherein the multilayer material is A core layer comprising at least one compressible material layer having a compressibility coefficient of approximately 1 MPa to approximately 12 MPa, and at least one thermal conductive layer and / or at least one thermal capacity layer, The invention comprises two insulating layers having a thermal conductivity of less than approximately 50 mW / m·K at 25°C and less than approximately 60 mW / m·K at 600°C, through the thickness dimensions of the insulating layers. The core layer is sandwiched between the two insulating layers. The multilayer material is optionally encapsulated in an encapsulation material.

56. The multilayer material according to claim 55, wherein the core layer further comprises a flame-retardant layer.

57. The multilayer material according to claim 55, wherein the core layer includes at least one thermal conductive layer.

58. The multilayer material according to claim 55, wherein the core layer includes at least one heat-capacitating layer.

59. The multilayer material according to claim 55, wherein the core layer comprises two thermal conductive layers and one compressible material layer, the compressible material layer being sandwiched between the two thermal conductive layers.

60. The multilayer material according to claim 55, wherein the core layer comprises two heat-capacitating layers and one compressible material layer, and the compressible material layer is sandwiched between the two heat-capacitating layers.

61. The multilayer material according to claim 55, wherein the core layer comprises one heat-capacitating layer and two compressible material layers, and the heat-capacitating layer is sandwiched between the two compressible material layers.

62. The multilayer material according to claim 55, wherein the multilayer material further comprises two heat-capacitating layers, each heat-capacitating layer being arranged on the outer surface of each insulating layer.

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