Mechanical barrier device with flow-through cooling for use in power systems.

Abstract

The present disclosure relates to materials and systems for managing thermal runaway problems in energy storage systems. Exemplary embodiments include a barrier having a mechanically compressible layer that allows fluid flow through the barrier. The present disclosure further relates to a battery module or pack having one or more battery cells, and the barrier disposed in thermal communication with the battery cells.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 285,680, filed December 3, 2021, and entitled “Mechanical Barrier Elements With Flow-Through Cooling For Use In Electrical Power Systems,” the contents of which are incorporated by reference in their entirety herein.

[0002] The present disclosure generally relates to barriers and systems for preventing or mitigating thermal events, such as thermal runaway problems, in energy storage systems while providing fluid cooling. The present disclosure further relates to battery modules or packs having one or more battery cells that include the barriers, as well as systems that include these battery modules or packs. [Background technology]

[0003] Rechargeable batteries, such as lithium-ion batteries, have found wide applications in power drives and energy storage systems. Lithium-ion batteries (LIBs) are widely used in powering portable electronic devices, such as mobile phones, tablets, laptops, power tools, and other high current devices, such as electric vehicles, due to their high operating voltage, low memory effect, and high energy density compared to conventional batteries. However, safety concerns have been raised due to the susceptibility of LIBs to catastrophic failure under "abuse conditions," such as when rechargeable batteries are overcharged (charged beyond their design voltage), overdischarged, operated 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 may fail due to rapid self-heating or thermal runaway events when subjected to conditions outside their design ranges.

[0004] As shown in Figure 1, the electrochemical cell of a LIB mainly consists of a positive electrode, a negative electrode, an electrolyte capable of conducting lithium ions, a separator that separates the positive electrode and the negative electrode, and a current collector. 0.8 Co 0.15 Al 0.05 O2(NCA) and LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2(NMC) are the six types of cathode materials widely used in Li-ion batteries. At present, these six types of batteries occupy the majority of the battery market share. The electrolyte consists of lithium salts dissolved in specific solvents (mainly including ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), and propylene carbonate (PC)). The lithium salts are generally selected from LiClO4, LiPF6, LiBF4, LiBOB, etc. The separator materials are generally polyolefin-based resin materials. Polypropylene (PP) and polyethylene (PE)-based microporous membranes are commonly used as separators in commercial lithium-ion batteries. Usually, aluminum foil is used as the current collector for the positive electrode, and copper foil is used for the negative electrode. Currently, carbon-based materials, including hard carbon, carbon nanotubes and graphene, are the predominant choice for the majority of negative electrodes in commercial lithium-ion batteries, and other novel anode materials, such as titanium-based oxides, alloying / de-alloying materials and conversion materials, have also been explored and have shown good thermal and electrochemical performance.

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

[0006] When a LIB is charged, lithium ions in the electrolyte migrate from the cathode, through the separator, and into the anode themselves (Figure 2). Charge-balancing electrons also migrate to the anode, but through an external circuit in the charger. During discharge, the reverse process occurs, with electrons flowing through the device to which power is being supplied (Figure 2). During this process, heat is generated in the cell by three main mechanisms. The first mechanism is reversible heat, which is caused by the entropic changes associated with the redox reactions that occur during the lithiation (discharging) and delithiation (charging) processes. Reversible heat is also called entropic heat. The second mechanism is irreversible heat, which is associated with electrode polarization caused by overvoltages in the cell. Finally, there is irreversible heat, called Joule heat, which is associated with ohmic losses. Joule heat is due to the movement of lithium ions and electrons in the cell. Under normal conditions, self-heating is very low, generally insignificant, and can be easily dissipated by good battery design or battery thermal management systems. However, under misuse conditions, several side reactions can occur that lead to thermal runaway. Understanding the cause of thermal runaway can guide the design of functional materials to improve the safety and reliability of LIBs.

[0007] Overview of thermal runaway and thermal runaway propagation Thermal runaway can occur when both reaction rate and heat generation are further increased by increasing the internal reaction rate to the point where more heat is being generated than can be removed. During thermal runaway, the temperature of the battery rises rapidly when high temperatures trigger a chain of exothermic reactions within the battery. Often, when thermal runaway occurs within one battery cell, the generated heat rapidly heats cells in the immediate vicinity of the cell experiencing thermal runaway. As each cell that participates in the thermal runaway reaction contains additional energy to continue the reaction, the thermal runaway propagates within the battery pack (Figure 3), eventually leading to a catastrophe involving fire or explosion. Promoting heat dissipation and having the effect of blocking the heat transfer path can be an effective measure to reduce the danger caused by thermal runaway propagation.

[0008] Thermal runaway induction - misuse conditions Thermal runaway can be triggered by various types of misuse, including mechanical, electrical, and thermal misuse (Figure 3). Each type of misuse can induce an internal short circuit (ISC) in the battery, which can cause an increase in temperature. Misuse conditions can be externally or internally initiated. For example, service-induced stress, aging, design (e.g., incorrect construction parameters such as cell spacing, cell interconnect style, cell form factor, etc.), manufacturing errors, operational errors, and maintenance errors are internal factors that can cause various types of misuse. External factors include breakage or damage to the LIB, such as from dropping or penetrating a cell.

[0009] Mechanical Abuse Mechanical abuse occurs primarily through mechanical forces, typically due to external factors such as severe vehicle collisions, including impacts, crushing, penetration, and bending. When a battery or battery pack is impacted or involved in a collision, potential damage to the battery internals, including separator rupture and leakage of flammable electrolyte, can occur, initiating ISC and resulting in thermal runaway. Destructive deformation and displacement caused by the application of force are two common characteristics of mechanical abuse. During a vehicle collision, there is a significant possibility of deformation of the battery pack. The layout of the battery pack installed in an electric vehicle affects the crash response of the battery pack. When the battery pack is deformed, the battery separator can tear, causing an internal short circuit (ISC), and if the flammable electrolyte leaks, there can be dangerous consequences such as fire. Penetration is another common phenomenon that can occur during a vehicle collision. Compared to a crushing condition, when a penetration is initiated, an immediate and violent ISC can be triggered. Mechanical breakdown and electrical shorting can occur simultaneously, and penetration abuse conditions can be more severe than simple mechanical or electrical abuse conditions.

[0010] Electrical Abuse The electrical abuse mainly includes internal or external short circuit, overcharging, and over-discharging of the LIB.

[0011] Internal short circuits occur in over 90% of abuse conditions. Roughly speaking, an internal short circuit occurs when the cathode and anode contact each other due to a failure of the battery separator. Internal short circuits can occur due to (1) mechanical abuse, when the separator is destroyed by penetration or crushing, (2) electrical abuse, when the separator is penetrated by dendrite growth (Figure 4), and (3) thermal abuse, when the separator is crushed at high temperatures.

[0012] An external short circuit is formed when electrodes with a voltage difference are connected by a conductor. An external short circuit in a battery pack can occur due to deformation during a car crash, water ingress, contamination by a conductor, or electric shock during maintenance. Compared to penetration, the heat released in an external short circuit generally does not heat the cells. An external short circuit can cause a large current and high heat to be generated in the battery, mainly due to the occurrence of ohmic heating. When the temperature starts to exceed about 70°C, the battery will start to explode. As a result, blowout and electrolyte leakage can be triggered.

[0013] Overcharging can be defined as charging a battery beyond its design voltage. Overcharging can be triggered by high specific current density, aggressive charging profile, etc., and can cause a series of problems including Li metal deposition on the anode, which severely impacts the electrochemical performance and safety of the battery, decomposition of the cathode material releasing oxygen, and decomposition of the organic electrolyte releasing heat and gaseous products (H2, hydrocarbons, CO, etc.). The overcharging process can be divided into three phases. In the first phase, (1) the voltage and temperature are not affected and remain substantially unchanged; in the second phase, (2) lithium dendrite deposition occurs on the voltage platform; and in the third phase, (3) the battery experiences thermal runaway as the voltage drops dramatically as heat and gas are generated.

[0014] Over-discharge is another possible electrical abuse condition. Generally, voltage mismatch between cells in a battery pack is inevitable. Therefore, when the battery management system is unable to monitor the voltage of any single cell, the cell with the lowest voltage will over-discharge. The over-discharge abuse mechanism is different from the others, and the potential danger may be underestimated. The cell with the lowest voltage in a battery pack can be forced to discharge by other cells connected in series during over-discharge. During the forced discharge, the polarity is reversed and the cell voltage becomes negative, which will generate abnormal heat when the cell is over-discharged.

[0015] Thermal Abuse Thermal abuse is typically triggered by overheating. Overheating of lithium-ion batteries can occur due to mechanical abuse, electrical abuse, and loss of contact in connectors. Generally, at normal operating temperatures, LIBs are stable, but above a certain temperature, the stability of LIBs becomes less predictable, and as temperatures increase, chemical reactions within the battery case produce gases and increase internal pressure within the battery case. These gases can further react with the cathode, releasing more heat and generating temperatures within or adjacent to the battery that can ignite the electrolyte in the presence of oxygen. As the electrolyte burns, oxygen is produced, further promoting combustion. At some point, the increased pressure within the battery case causes the battery case to burst. The gases can ignite and burn if they leak.

[0016] Thermal runaway can occur due to mechanical, electrical and thermal abuse conditions, which induces continuous heat generation, thus increasing the temperature inside the battery. A series of chain reactions can occur at different stages as the temperature increases. Thermal runaway follows a chain reaction mechanism, e.g., physical and / or chemical processes, during which the decomposition reactions of the battery component materials occur one after the other (Figure 3).

[0017] Overview of the chain reaction during thermal runaway Understanding the evolution of these physical and / or chemical processes can help develop mitigation measures for thermal runaway in LIBs. LIBs can have different triggers for thermal runaway in different temperature states or regions (Figure 5), including State I: low temperature (<0°C), State II: ambient temperature (0-90°C), and State III: high temperature (>90°C).

[0018] In state I, LIBs cannot function efficiently due to the slowdown of electrochemical reaction rates at low temperatures. At low temperatures, the activity of electrode materials decreases and the rate of lithium ion diffusion in the electrolyte decreases, resulting in a dramatic drop in battery performance. The consequences of the slowdown of chemical reactions at low temperatures include unwanted Li deposition, plating, and dendrite growth. Dendrites are tree-like structures that can form on lithium plating in the battery. They can rapidly penetrate the battery separator, a porous plastic film between the battery anode and cathode (Figure 4). Li deposition and dendrite growth in the cell are considered the main contributing factors for inducing thermal runaway at low temperatures. Without wishing to be bound by theory, it is believed that unwanted Li deposition and dendrites can cause ISC in the battery, leading to thermal runaway.

[0019] In state II (room temperature operation), heat generation is minimal compared to the heat generated in the thermal runaway process. Heat generation during this operating state occurs mainly due to the diffusion of Li-ions in the solid and liquid phases, electrochemical reactions at the solid-liquid interface, and side reactions. Heat generation can cause temperature rise and temperature differences inside the battery, which can affect the life and safety of lithium-ion batteries. During state II, initial overheating can occur as a result of at least one of the internal or external triggers mentioned above, such as overcharging the battery, exposure to excessive temperatures, external short circuit due to wiring faults, or internal short circuit due to cell failure. Once initial overheating begins, the battery operation changes from normal to abnormal as the temperature increases toward 90°C. Temperatures higher than 40°C can shorten the life of the lithium-ion battery due to faster side reactions, and temperatures near or above 90°C can trigger the decomposition of the solid electrolyte interface (SEI) film, which is defined as the onset of thermal runaway. During the first few charging cycles, an SEI is generated on the anode of the lithium-ion battery. The SEI provides a passivation layer on the anode surface that inhibits further electrolyte decomposition and provides the long calendar life required for many applications. The initial decomposition of the SEI is considered the first side reaction occurring during the complete thermal runaway process. The initial decomposition of the SEI occurs between 80 and 120°C, with the peak located at about 100°C. The onset temperature can be below 80°C, as reported by Wang et al. (Thermochim. Acta 437 (2005) 12-16) that SEI decomposition can begin at temperatures as low as 57°C.

[0020] Decomposition of SEI When stage III begins, the internal temperature rises rapidly and the SEI film decomposes. The SEI layer mainly consists of stable components (such as LiF and Li2CO3) and metastable components (polymers, ROCO2Li, (CH2OCO2Li)2, and ROLi). However, the metastable components can exothermically decompose at approximately >90°C, releasing flammable gases and oxygen. The decomposition of the SEI film is considered the beginning of thermal runaway, which then triggers a series of exothermic reactions.

[0021] Due to the decomposition of the SEI, the temperature increases and the lithium metal or intercalated lithium in the anode reacts with the organic solvent in the electrolyte to release flammable hydrocarbon gases (ethane, methane, etc.), an exothermic reaction that further increases the temperature.

[0022] Disassembly of the separator For T > approx. 130°C, the polyethylene (PE) / polypropylene (PP) separator begins to melt, further exacerbating the situation and causing a short circuit between the cathode and anode. While the melting of the PE / PP separator is a thermal adsorption process, the ISC caused by the separator melting further exacerbates the thermal runaway process.

[0023] Gas evolution and electrolyte decomposition For T > approx. 180°C, heat generation by ISC causes the lithium metal oxide cathode material to decompose and release oxygen. Cathode breakdown is also highly exothermic, further increasing the temperature and pressure, which in turn accelerates the reaction. Heat accumulation and gas release (oxygen and flammable gases) can then induce combustion and explosion of the lithium-ion battery.

[0024] In the thermal runaway process, the heat generation caused by ISC is only 2%, while chemical reactions account for 98%, including the decomposition of the SEI layer, decomposition of the electrolyte, etc. The highest percentage of heat generation is caused by the rapid oxidation-reduction reaction between the cathode and anode, which accounts for about 48%, while the heat generation of other chemical reactions in the anode, cathode and electrolyte is much smaller. The smallest heat generation is the decomposition of the SEI film.

[0025] The need for thermal runaway mitigation measures Based on the understanding of the mechanisms that lead to thermal runaway in batteries, many approaches have been investigated with the aim of mitigating safety hazards through rational design of battery components. To prevent such cascades of thermal runaway events from occurring, LIBs are typically designed to either keep the stored energy low enough, or use sufficient insulating material between cells in a battery module or pack to insulate them from possible thermal events in adjacent cells, or a combination of both. The former significantly limits the amount of energy that can potentially be stored in such devices. The latter limits the effective energy density by restricting the extent to which cells can be placed in close proximity. Effective insulation and thermal dissipation strategies are needed to mitigate the possibility of thermal runaway in LIBs.

[0026] Current heat dissipation methods used in LIBs Currently, there are many different methods used to maximize energy density while preventing thermal runaway cascades. One approach is to incorporate a sufficient amount of insulation between cells or cell clusters. This approach is generally considered desirable from a safety perspective, but in this approach, the ability of the insulating material to contain heat combined with the volume of insulation required determines the upper limit of the energy density that can be achieved. Another approach is through the use of phase change materials. These materials undergo an endothermic phase change when a certain elevated temperature is reached. The endothermic phase change cools the local area by absorbing some of the heat that is generated. Typically, for power storage devices, these phase change materials rely on hydrocarbon materials such as waxes and fatty acids. Although these systems are effective for cooling, they are combustible themselves and therefore are not beneficial in preventing thermal runaway once ignition in the storage device occurs. The incorporation of intumescent materials is another measure to prevent thermal runaway cascades. These materials are designed to expand above a certain temperature and produce a charred layer that is lightweight and provides thermal insulation where needed. While these materials can be effective in providing an insulating effect, the expansion of the material must be taken into account in the design of the storage device.

[0027] The need for novel thermal barriers to meet the mechanical requirements of LIB systems Swelling of the anode and cathode during charging and discharging can cause the cell to change dimensions (swell). For example, silicon has a typical volume change of up to 300% during intercalation, and graphite has a volume expansion of about 10%. This change has both reversible and irreversible components, the magnitude of which depends on the exact cell chemistry. Reversible changes in cell thickness depend only on the cell's state of charge (SOC) and can result in thickness increases of more than 2%. Irreversible swelling of the cell is associated with an increase in pressure inside the cell and occurs due to the formation of the SEI. The largest component of this change occurs during the first charging cycle, when the SEI is first formed, but swelling continues during the life of the cell.

[0028] Extensive research has been conducted to create new materials with favorable thermal properties to prevent thermal runaway problems, but the mechanical properties of those materials have received less attention, despite their importance. For example, there is a need for an effective thermal barrier that can be used between cells in a battery module or battery pack and resist compressive deformation to accommodate subsequent cell swelling during the life of the cell. In addition, during the initial assembly of the battery module, a relatively low load, typically 1 MPa or less, is applied to the material between the cells. When the cells in the battery module or battery pack expand or swell during charge / discharge cycles, loads of up to about 5 MPa can be applied to the material between the cells. Therefore, compressibility, compressive recovery, and compliance of the material, e.g., the thermal barrier between the cells, are important properties.

[0029] Therefore, new thermal barriers that meet the mechanical requirements of LIB systems are needed to provide effective thermal insulation under thermal runaway conditions and effective heat dissipation under normal conditions. Summary of the Invention

[0030] It is an object of the present disclosure to obviate or mitigate at least one of the shortcomings of the above-mentioned previous methods and materials for preventing or mitigating thermal runaway in rechargeable batteries, such as lithium-ion batteries. The barrier materials provided herein are designed to improve the safety of lithium-ion batteries.

[0031] In particular, it is an object of the present disclosure to provide a barrier for use as a thermal barrier in an electrical energy storage system to solve the problem of heat propagation in a battery module or battery pack and to stop or mitigate heat propagation in the event that one cell has a thermal runaway. The unique configuration of the barrier of the present disclosure can be useful in solving the problem of heat propagation between cells. The barrier of the present disclosure can also be useful in dissipating heat generated during normal use of the battery module or battery pack. A heat transfer fluid can be passed through the barrier using flow paths defined within the barrier, which can be useful in regulating the temperature of the battery module or battery pack.

[0032] Mitigation measures can function at the material level, cell level, and system level to ensure the overall safety of energy storage systems that use rechargeable batteries such as lithium-ion batteries. The barriers according to the present disclosure can perform at least one of the following mitigation steps: (1) reduce the likelihood of abuse conditions, (2) eliminate abuse conditions once they occur, (3) improve the thermal stability of the battery cells against abuse conditions, (4) reduce the energy released under normal operating conditions and thermal runaway cases, and (5) mitigate the risk of propagation and limit damage to a limited area.

[0033] Another object of the present disclosure is to provide a battery module or pack including a barrier according to the present invention, which can protect the battery pack from thermal damage due to thermal runaway of one cell and ensure a safe design of the battery pack.

[0034] In one general aspect, the present disclosure provides novel barriers comprising aerogel compositions, e.g., reinforced aerogel compositions, that are durable, easy to handle, and have favorable resistance to heat and flame propagation while minimizing the thickness and weight of the materials used, as well as favorable properties of compressibility, compression recovery, and compliance. For example, a barrier according to an aspect disclosed herein can include at least one insulating layer comprising an aerogel composition or a reinforced aerogel composition.

[0035] In one general aspect, the barriers disclosed herein are useful for isolating, insulating and protecting battery cells or battery components of any configuration of battery, e.g., pouch cells, cylindrical cells, non-circular cells, as well as packs and modules incorporating or including any such cells. The barriers disclosed herein are useful for rechargeable batteries, e.g., lithium ion batteries, solid-state batteries, and any other energy storage device or technology where isolation, insulation and protection is required.

[0036] In one general aspect, the present disclosure aims to provide battery modules and battery packs that are used to simultaneously improve the heat dissipation and thermal runaway protection performance of an electrical energy storage system. In an electrical energy storage system, it is common for a number of cells 100 to be packed together in a preselected arrangement (e.g., in parallel, in series, or in combination) to form a battery module 200 (see FIG. 6). A number of such battery modules may be combined or joined to form various battery packs 300 as known in the art. During operation and discharge, such cells, battery modules, or battery packs generally generate or generate amounts of heat that can significantly and adversely affect the performance resulting therefrom. Thus, in order to maintain a desired or optimal performance by such cells or the resulting battery module or battery pack, it is generally important to maintain the temperature of such cells, battery modules, or battery packs within a very narrow predetermined range. It is an objective of the present disclosure to keep the temperature of such cells, battery modules, or battery packs within an optimal range.

[0037] In addition to maintaining the temperature of the cell within a given range, the goal is to maintain the structural integrity of the cell. The materials within the cell must be both compliant and resilient to accommodate changes in volume during battery operation. In some embodiments, the materials must be flame or fire resistant to maintain structural integrity after or during a thermal event.

[0038] In one aspect, provided herein is a barrier for use between battery cells in an electrical energy storage system, the barrier including at least one insulating layer and at least one compressible layer coupled to the at least one insulating layer, the compressible layer including a pair of rigid plates and one or more spring elements disposed between the rigid plates.

[0039] In some embodiments, at least one of the pair of rigid plates is a thermally conductive plate. The thermally conductive plate can have a thermal conductivity of at least about 200 mW / mK. The thermally conductive plate can be made of a metal, such as aluminum, copper, or stainless steel.

[0040] In some embodiments, the pair of rigid plates are identical in size and shape, and the pair of rigid plates are in an aligned configuration. When in the aligned configuration, an outer edge of one of the pair of rigid plates is substantially aligned with an outer edge of the other of the pair of rigid plates. A guide may be positioned between the pair of rigid plates. The guide may be useful for maintaining the rigid plates in the aligned configuration.

[0041] A variety of different spring elements may be used in the compressible layer. In some embodiments, the one or more spring elements include one or more cantilever spring elements. In some embodiments, the one or more spring elements include one or more coil springs. In some embodiments, the one or more spring elements include one or more bow springs. In some embodiments, the one or more spring elements include one or more wave springs. A combination of different types of springs may also be used in the compressible layer.

[0042] In some embodiments, the spring element is configured to press the rigid plate against an adjacent battery cell in the electrical energy storage system. The spring element may have a spring constant that allows the spring element to compress as the adjacent battery cell expands during use. In some embodiments, the one or more springs are positioned between the rigid plates such that a flow passage is formed between the rigid plates. If present, the flow passage has a width between 1 mm and 5 mm.

[0043] In some embodiments, the insulating layer has a thermal conductivity through a thickness dimension of the insulating layer of less than about 50 mW / mK at 25° C. and less than about 60 mW / mK at 600° C. In some embodiments, the insulating layer comprises an aerogel. In some embodiments, the insulating layer further comprises a material selected from the group consisting of mica, microporous silica, ceramic fibers, mineral wool, and combinations thereof. In some embodiments, the insulating layer is devoid of aerogel, and the insulating layer comprises a material selected from the group consisting of mica, microporous silica, ceramic fibers, mineral wool, and combinations thereof.

[0044] In some embodiments, the insulating layer comprising aerogel further comprises a reinforcing material. In some embodiments, the reinforcing material is a fiber selected from organic polymer-based fibers, inorganic fibers, carbon-based fibers, or combinations thereof. In some embodiments, the fiber is in the form of a staple fiber, a woven material, a dry-laid nonwoven material, a wet-laid nonwoven material, a needled nonwoven, a batting, a web, a mat, a felt, and / or combinations thereof. In some embodiments, the inorganic fiber is selected from glass fiber, rock fiber, metal fiber, boron fiber, ceramic fiber, basalt fiber, or combinations thereof. In one or more embodiments, the aerogel comprises a silica-based aerogel.

[0045] In one or more embodiments, the aerogel comprises one or more additives, the additives being present at a level of at least about 5-40 weight percent of the aerogel, preferably at a level of at least about 5-20 weight percent of the aerogel, more preferably at a level of at least about 10-20 weight percent of the aerogel. In some embodiments, the one or more additives comprise a fire class additive. In some embodiments, the one or more additives comprise an opacifying agent selected from B4C, diatomaceous earth, manganese ferrite, MnO, NiO, SnO, Ag2O, Bi2O3, TiC, WC, carbon black, titanium dioxide, 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, the one or more additives comprise an opacifying agent containing silicon carbide. In some embodiments, the one or more additives comprise a combination of a fire class additive and an opacifying agent.

[0046] 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 has a compression set in the range of about 10% to about 25% at about 70° C. In some embodiments, the aerogel exhibits compression resistance, the compression resistance at 25% strain being between about 40 kPa to about 180 kPa. In one or more embodiments, the aerogel is in the form of a monolith, beads, particles, granules, powder, thin film, sheet, or combinations thereof.

[0047] In some embodiments, the insulating layer is encapsulated by a facing layer. In embodiments where a hydrocarbon heat transfer fluid is used in the battery module or battery pack, the facing layer is inert to the hydrocarbon dielectric fluid. In embodiments where a fluorine-based heat transfer fluid is used in the battery module or battery pack, the facing layer is inert to the fluorine-based dielectric fluid.

[0048] In some embodiments, the barrier has an average thickness in the uncompressed state within the range of between about 5 mm and about 30 mm, and the barrier is compressible to a minimum average thickness of between about 2 mm and 10 mm.

[0049] In one aspect, provided herein is the use of the barrier of various embodiments of any of the above aspects in a battery module including a plurality of single battery cells. In another aspect, provided herein is the use of the barrier of various embodiments of any of the above aspects in an embodiment of a battery pack including a plurality of battery modules. The barrier can be used to thermally isolate single battery cells or single battery modules from each other. In some embodiments, a runaway event occurring in one or more battery cells or battery modules of one portion of a battery pack does not damage the battery cells or battery modules in the portion of the battery pack that is separated by a battery according to any one of the above aspects.

[0050] In one aspect, provided herein is a battery module including a first battery cell having a first surface, a second battery cell having a second surface, the second surface being in opposing relationship to the first surface, and a barrier according to various embodiments of any of the above aspects disposed between the first and second surfaces, hi some embodiments, the barrier covers at least about 80% of the surface area of ​​the opposing first and second surfaces.

[0051] In another aspect, provided herein is a battery module including a plurality of battery cells and a barrier according to various embodiments of any of the aspects above, the barrier being disposed between adjacent battery cells.

[0052] In one aspect, provided herein is a battery pack including a plurality of cells and a spacer disposed between two adjacent cells or two adjacent modules, the spacer including a barrier according to various embodiments of any of the aspects above.

[0053] In one aspect, a power supply system includes one or more battery modules as according to various embodiments of any of the above aspects, and a fluid transfer system coupled to the battery modules. The fluid transfer system delivers fluid into the battery modules and collects the fluid after it passes through the battery modules. The fluid transfer system delivers a dielectric liquid fluid into the battery modules or delivers a dielectric gas into the battery modules. In some aspects, the fluid is heated or cooled such that the fluid heats or cools, respectively, a plurality of battery cells in the battery modules.

[0054] In one aspect, the barrier according to various embodiments of any of the above aspects defines a flow path between adjacent pairs of battery cells. In use, a fluid flows through the flow path. In some aspects, the battery module includes a manifold coupled to a fluid transfer system having one or more ports aligned with the flow path, and in use, fluid from the fluid transfer system enters the manifold, exits through one or more outlets, and enters the flow path. The fluid transfer system can include a cooling component. The cooling component can be used to maintain a temperature of the fluid at or below the operating temperature of the battery cells.

[0055] In one aspect, the power system includes a battery pack, the battery pack including a plurality of battery modules and batteries disposed between adjacent battery modules and a fluid transfer system coupled to the battery pack as described above, the fluid transfer system directs fluid into the battery pack and collects the fluid after it passes through the battery pack. The fluid transfer system directs a dielectric liquid fluid into the battery pack or directs a dielectric gas into the battery pack. In some aspects, the fluid is heated or cooled such that the fluid heats or cools, respectively, the plurality of battery modules in the battery pack.

[0056] In one aspect, the barrier according to various embodiments of any of the above aspects defines a flow path between adjacent pairs of battery modules. In use, a fluid flows through the flow path. In some aspects, the battery pack includes a manifold coupled to a fluid transfer system having one or more ports aligned with the flow path, and in use, fluid from the fluid transfer system enters the manifold, exits through one or more outlets, and enters the flow path. The fluid transfer system can include a cooling component. The cooling component can be used to maintain a temperature of the fluid at or below the operating temperature of the battery modules.

[0057] In one embodiment, the spring elements in the barrier are disposed between a pair of rigid plates to create turbulent flow. In some embodiments, the turbulent flow is a flow having a Reynolds number greater than 1000.

[0058] In another aspect, provided herein is a device or vehicle comprising a battery module or pack according to any one of the above aspects. In some embodiments, the device is a laptop computer, a PDA, a mobile phone, a tag scanner, an audio device, a video device, a display panel, a video camera, a digital camera, a desktop computer, a military portable computer, a military telephone, a laser range finder, a digital communication device, an information gathering sensor, an electronics integrated garment, a night vision device, a power tool, a calculator, a radio, a remote control appliance, a GPS device, a handheld and portable television, an automobile starter, a flashlight, a sound device, a portable heating device, a portable vacuum cleaner, or a portable medical device. In some embodiments, the vehicle is an electric car.

[0059] The barriers described herein can provide one or more advantages over existing thermal runaway mitigation solutions. The barriers described herein can minimize or eliminate thermal runaway propagation in cells without significantly impacting the energy density and assembly costs of the battery module or pack. The barriers of the present disclosure can provide favorable compressibility, compression recovery, and compliance properties to accommodate continued cell swelling while having favorable thermal properties under thermal runaway conditions as well as under normal operating conditions during the life of the cell. The barriers described herein are durable, easy to handle, and have favorable resistance to heat and flame propagation while minimizing the thickness and weight of the materials used, yet also have favorable compressibility, compression recovery, and compliance properties.

[0060] Having thus described the disclosure in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale. [Brief description of the drawings]

[0061] [Figure 1] FIG. 1 is a schematic diagram of an electrochemical cell of a Li-ion battery. [Diagram 2] FIG. 1 is a schematic diagram of the charge and discharge process in a Li-ion battery. [Diagram 3] 1 illustrates a schematic of a thermal runaway abuse condition and a thermal runaway propagation process in a battery module. [Figure 4] FIG. 1 is a schematic diagram of dendritic growth on lithium plating in a battery. [Diagram 5] The three stages leading to the thermal runaway process are shown diagrammatically. [Figure 6] 1 illustrates a schematic diagram of a battery cell, a battery module, and a battery pack. [Figure 7] 1 illustrates a schematic representation of a barrier according to certain embodiments disclosed herein. [Figure 8] 13A-13C illustrate schematic diagrams of alternative barrier configurations in accordance with certain embodiments disclosed herein. [Figure 9A] 1 shows a schematic of a battery cell before expansion and compression of the barrier. [Figure 9B] 13A-13C show schematic diagrams of a battery cell after expansion and compression of the barrier. [Figure 10A] 1A and 1B are schematic diagrams illustrating a top view of a compressible layer with linear wave springs. [Figure 10B] 1A and 1B illustrate schematic side views of a compressible layer with linear wave springs. [Figure 11A] 1A and 1B show schematic diagrams of a top view of a compressible layer with a cantilever spring. [Figure 11B] 1A and 1B show schematic diagrams of a side view of a compressible layer with a cantilever spring; [Figure 12] 1 illustrates a schematic representation of a compressible layer having dimple spring elements. [Figure 13] 1 illustrates a schematic representation of a compressible layer with a coil spring. [Figure 14A] 1A and 1B show schematic top views of a compressible layer with bow springs. [Figure 14B] 1A and 1B show schematic side views of a compressible layer with bow springs. [Figure 15A] 13A and 13B illustrate schematic top views of a compressible layer having a bow spring disposed within an indentation formed in a rigid plate. [Figure 15B] 1A and 1B are schematic diagrams illustrating a side view of a compressible layer having a bow spring disposed within an indentation formed in a rigid plate. [Figure 16] 13A-13C illustrate diagrammatically the use of flow channels defined in a compressible layer by spring elements for cooling of battery cells. [Figure 17] 1 illustrates a schematic diagram of an energy storage system including a battery module or battery pack coupled to a heat transfer unit and a fluid transport system including a pump for circulating a heat transfer fluid. [Figure 18] 1 illustrates a schematic of a battery module or battery pack having a fluid manifold. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0062] In the following detailed description of the preferred embodiments, references are made to the accompanying drawings that form a part hereof, and which show by way of illustration specific embodiments in which the disclosure may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present disclosure.

[0063] It is to be understood that the present disclosure is not limited to any particular device or method, which may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. As used in this specification and the appended claims, the singular forms "a," "an," and "the" include singular and plural referents unless the content clearly dictates otherwise. Furthermore, the word "may" is used throughout this application in its permissive sense (i.e., "may" or "can") and not its mandatory sense (i.e., "must"). The term "include" and its derivatives mean "including, but not limited to." The term "coupled" means directly or indirectly connected.

[0064] definition As used herein, "about" means approximately or near, and in the context of a stated numerical value or range, means ±5% of the numerical value. In one embodiment, the term "about" can include conventional rounding to significant figures of a numerical value. Furthermore, the phrase "about 'x' to 'y'" includes "about 'x' to about 'y'".

[0065] As used herein, the terms "composition" and "composite" are used interchangeably.

[0066] As used herein, the terms "compressible pad" and "compressible layer" are used interchangeably.

[0067] Within the context of the present disclosure, the terms "aerogel," "aerogel material," or "aerogel matrix" refer to a gel that includes a framework of interconnected structures, has a corresponding network of interconnected pores integrated within the framework, and contains a gas, such as air, as a dispersed interstitial medium, that exhibits the following properties that are attributed to aerogels: (a) an average pore size in the range of about 2 nm to about 100 nm; (b) a porosity of at least 80% or greater; and (c) a porosity of at least about 100 nm. 2 It is characterized by the physical and structural property of having a surface area of ​​0.1 μm / g or more (as determined by nitrogen porosimetry testing).

[0068] Thus, the aerogel materials of the present disclosure include any aerogel or other open cell material that meets the defining elements set forth in the preceding paragraph, including materials that may be otherwise categorized as xerogels, cryogels, ambigels, microporous materials, etc.

[0069] The aerogel material may also be further 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, more particularly about 0.25 g / cc or less, and (f) at least 50% of the total pore volume comprises pores having a pore diameter between 2 and 50 nm (although embodiments disclosed herein include aerogel frameworks and compositions that include pores having a pore diameter greater than 50 nm, as discussed in more detail below). However, these additional properties need not be met to characterize a compound as an aerogel material.

[0070] Within the context of this disclosure, the term "aerogel composition" refers to any composite material that includes an aerogel material as a component of the composite. Examples of aerogel compositions include, but are not limited to, fiber-reinforced aerogel composites; aerogel composites that include added elements such as opacifying agents; aerogel composites reinforced by an open-cell macroporous framework; aerogel-polymer composites; and composites that incorporate aerogel particulates, particles, granules, beads, or powders into solid or semi-solid materials, such as combining them with binders, resins, cements, foams, polymers, or similar solid materials. Aerogel compositions are generally obtained after removing the solvent from the various gel materials disclosed herein. The aerogel compositions thus obtained may undergo further processing or treatment. The various gel materials may also undergo additional processing or treatment that is otherwise known or useful in the art before undergoing solvent removal (or liquid extraction or drying).

[0071] The aerogel compositions of the present disclosure may include reinforced aerogel compositions. Within the context of the present disclosure, the term "reinforced aerogel composition" refers to an aerogel composition that includes a reinforcing phase within the aerogel material, where the reinforcing phase is not part of the aerogel framework itself.

[0072] Within the context of this disclosure, the term "fiber reinforced aerogel composition" refers to a reinforced aerogel composition that includes a fiber reinforcement material as the reinforcing phase. Examples of fiber reinforcement materials include, but are not limited to, staple fibers, woven materials, dry-laid nonwoven materials, wet-laid nonwoven materials, needled nonwovens, battings, webs, mats, felts, and / or combinations thereof.

[0073] The fiber reinforcement material can be selected from organic polymer-based fibers, inorganic fibers, carbon-based fibers, or combinations thereof. The fiber reinforcement material can be polyester, polyolefin terephthalate, poly(ethylene) naphthalate, polycarbonate (e.g., rayon, nylon), cotton (e.g., Lycra manufactured by DuPont), carbon (e.g., graphite), polyacrylonitrile (PAN), oxidized PAN, uncarbonized heat-treated PAN (e.g., manufactured by SGL Carbon), glass or glass fiber-based materials (S-glass, 901 glass, 902 glass, 475 glass, E-glass, etc.), silica-based fibers such as quartz (e.g., Quartz manufactured by Saint-Gobain), Q felt (Johns Polyamide fibers such as Duraback (manufactured by Carborundum), Kevlar, Nomex, Sontera (all manufactured by DuPont), and Conex (manufactured by Taijin); polyolefins such as Tyvek (manufactured by DuPont), Dyneema (manufactured by DSM), and Spectra (manufactured by Honeywell); other polypropylene fibers such as Typar and Xavan (both manufactured by DuPont); fluoropolymers such as PTFE, which have trade names such as Teflon (manufactured by DuPont) and Goretex (manufactured by WLGORE); The range of materials may include, but are not limited to, silicon carbide fibers such as silicon carbide fibers manufactured by Epson Ceramics, ceramic fibers such as Nextel manufactured by 3M, acrylic polymers, wool, silk, hemp, leather, suede fibers, PBO-Zylon fibers manufactured by Tyobo, liquid crystal materials such as Vectan manufactured by Hoechst, Cambrelle fibers manufactured by DuPont, polyurethanes, polyamides, wood fibers, boron, aluminum, iron, stainless steel fibers, and other thermoplastics such as PEEK, PES, PEI, PEK, PPS, etc. Glass or glass fiber based fiber reinforced materials may be manufactured using one or more techniques. In certain embodiments, it is desirable to make them using carding and cross-lapping or airlaid processes.In exemplary embodiments, carded and cross-wrapped glass or fiberglass based fibrous reinforcement materials offer certain advantages over airlaid materials. For example, carded and cross-wrapped glass or fiberglass based fibrous reinforcement materials can provide consistent material thickness for a given basis weight of reinforcement material. In certain additional embodiments, it may be desirable to further needle the fibrous reinforcement material, which requires entangling of the fibers in the z-direction, to improve mechanical and other properties in the final aerogel composition.

[0074] Within the context of this disclosure, references to "thermal runaway" generally refer to a sudden, rapid increase in cell temperature and pressure due to various operating factors, which can result in excessive temperature propagation throughout the associated module. Potential causes of thermal runaway in such systems may include, for example, cell failure and / or short circuit (both internal and external), overcharging, cell puncture or bursting such as in the case of an accident, and excessive ambient temperature (e.g., temperatures generally above 55°C). In normal use, cells heat up as a result of their internal resistance. Under normal power / current loads and ambient operating conditions, the temperature within most Li-ion cells can be relatively easily controlled to stay within the range of 20°C to 55°C. However, stressful conditions such as high power consumption at high cell / ambient temperatures, as well as individual cell failures, can rapidly increase localized heat generation. In particular, above a critical temperature, exothermic chemical reactions within the cells are activated. Furthermore, chemical heat generation generally increases exponentially with temperature. As a result, heat generation becomes much greater than the available heat dissipation. Thermal runaway could cause cells to erupt and internal temperatures to exceed 200°C.

[0075] Within the context of the present disclosure, the terms "flexible" and "flexibility" refer to the ability of a material or composition to bend or flex without macrostructural failure. The compressible layers of the present disclosure can be compressed at least 5%, at least 25%, at least 45%, at least 65%, or at least 85% without macroscopic failure. Similarly, the terms "highly flexible" or "highly flexible" refer to a material that can be bent to at least 90° without macroscopic failure and / or have a bend radius of less than U inches. Additionally, the terms "classified flexible" and "classified as flexible" refer to a material or composition that can be classified as flexible according to ASTM Cl 101 (ASTM International, West Conshohocken, PA).

[0076] The insulating layers of the present disclosure can be flexible, highly flexible, and / or graded flexible. The aerogel compositions of the present disclosure can also be drapeable. Within the context of the present disclosure, the terms "drapeable" and "drapeability" refer to the ability of a material to bend or flex 90° or more with a radius of curvature of about 4 inches or less without macroscopic failure. The insulating layers according to certain embodiments of the present disclosure are flexible such that the compositions are non-rigid and may be applied or conformed to a three-dimensional surface or object, or may be preformed into various shapes and configurations to simplify installation or application.

[0077] Within the context of this disclosure, the term "additive" or "additive element" refers to a material that may be added to an aerogel composition before, during, or after the production of the aerogel. Additives may be added to modify or improve desirable properties in the aerogel or to counter undesirable properties in the aerogel. Additives are generally added to the aerogel material either before gelation to a precursor liquid, during gelation to a transition state material, or after gelation to a solid or semi-solid material.

[0078] Examples of additives include, but are not limited to, microfibers, fillers, reinforcing agents, stabilizers, thickening agents, elastic compounds, opacifying agents, coloring or pigmentation compounds, radiation absorbing compounds, radiation reflecting compounds, fire class additives, corrosion inhibitors, thermally conductive components, components that impart heat capacity, phase change materials, pH adjusters, redox adjusters, HCN mitigating agents, off-gassing mitigating agents, electrically conductive compounds, electrically dielectric compounds, magnetic compounds, radar blocking components, hardeners, anti-shrinkage agents, and other aerogel additives known to those skilled in the art.

[0079] In certain embodiments, the aerogel compositions, reinforced aerogel compositions, and barriers disclosed herein can perform during a high temperature event, for example, can provide thermal protection during a high temperature event as disclosed herein. A high temperature event can be a temperature rise of at least about 1 cm for at least 2 seconds. 2 at least about 25 kW / m 2 , at least about 30 kW / m 2 , at least about 35 kW / m 2 , or at least about 40 kW / m 2 It is characterized by a sustained heat flux of about 40 kW / m 2 Heat fluxes of at least about 10 cm are associated with those resulting from general ignition (Behavior of Charring Solids under Fire-Level Heat Fluxes; Milosavljevic, I., Suuberg, EM; NISTIR 5499; September 1994). In particular, a high temperature event is a heat flux of at least about 10 cm for a duration of at least 1 minute. 2 The heat flux over the area is about 40 kW / m.

[0080] Within the context of this disclosure, the terms "thermal conductivity" and "TC" refer to a measurement of the ability of a material or composition to transfer heat between two surfaces on either side of the material or composition, with a temperature difference between the two surfaces. Specifically, thermal conductivity is measured as the heat energy transferred per unit time and per unit surface area divided by the temperature difference. It is generally expressed in mW / m * K(meter*It is recorded in SI units as milliwatts per kelvin. The thermal conductivity of the material is determined using the 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,United Kingdom);or Determination of steady-state thermal resistance and related properties-Guarded hot plate apparatus (ISO 8203, International Organization for Standardization, Switzerland). Due to different methods that may yield different results, it is understood that within the context of this disclosure, unless expressly stated otherwise, thermal conductivity measurements are taken in accordance with the ASTM C518 standard (Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus) at a temperature of about 37.5°C, at atmospheric pressure in the ambient environment, and under a compressive load of about 2 psi. Measurements reported in accordance with ASTM C518 generally correlate well with any measurements made in accordance with EN 12667 with any associated adjustments for compressive load.;

[0081] Thermal conductivity measurements can also be taken under compression at atmospheric pressure at a temperature of about 10° C. Thermal conductivity measurements at 10° C. are typically 0.5 to 0.7 mW / mK lower than 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. of 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 within a range between any two of these values.

[0082] Within the context of this disclosure, the term "density" refers to a measure of the mass per unit volume of a material or composition. The term "density" generally refers to the apparent density of a material as well as the bulk density of a composition. Density is generally expressed in kg / m 3The density of a material or composition, such as an aerogel, may be determined by methods known in the art, including, but 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). Due to different methods that may yield different results, it is understood that within the context of this disclosure, density measurements are taken according to ASTM C167 standard (Standard Test Methods for Thickness and Density of Blanket or Batt Thermal Insulations) at 2 psi compression for thickness measurements unless otherwise noted.In certain embodiments, the aerogel material or composition of the present disclosure has a density 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 within a range between any two of these values.

[0083] The hydrophobicity of an aerogel material or composition can be expressed in terms of water vapor uptake. Within the context of this disclosure, the term "water vapor uptake" refers to a measure of the ability of an aerogel material or composition to absorb water vapor. Water vapor uptake can be expressed as the percentage (by weight) of water absorbed or otherwise retained by the aerogel material or composition when exposed to water vapor under specific measurement conditions. The water vapor uptake of an aerogel material or composition can be determined by methods known in the art, including, but not limited to, 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: Determination of long term water absorption by diffusion (EN 12088, British Standards Institution, United Kingdom). It is understood that, within the context of this disclosure, measurements of water vapor uptake are taken according to ASTM C1104 (Standard Test Method for Determining the Water Vapor Sorption of Unfaced Mineral Fiber Insulation) at 49° C. and 95% humidity under ambient pressure for 24 hours (modified from 96 hours according to ASTM C1104) unless otherwise noted, due to different methods that may yield different results. In certain embodiments, the aerogel materials or compositions of the present disclosure can have a water vapor uptake 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 within a range between any two of these values.An aerogel material or composition has improved water vapor uptake compared to another aerogel material or composition and has a lower percent water vapor uptake / retention compared to a reference aerogel material or composition.

[0084] The hydrophobicity of an aerogel material or composition can be expressed by measuring the equilibrium contact angle at the interface of the material surface with a water droplet. The aerogel materials or compositions of the present disclosure can have a water contact angle 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 within a range between any two of these values.

[0085] Within the context of this disclosure, the terms "heat of combustion", "HOC", and "ΔΗC" refer to a measurement of the amount of heat energy released during the combustion or exothermic pyrolysis of a material or composition. Heat of combustion is generally recorded in calories of heat energy released per gram of aerogel material or composition (cal / g) or as megajoules of heat energy released per kilogram of material or composition (MJ / kg). Heat of combustion of a material or composition may 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). Within the context of this disclosure, measurements of heat of combustion are taken according to the EN ISO 1716 standard (Reaction to fire tests for products-Determination of the gross heat of combustion (calorific value)) unless otherwise specified.

[0086] Within the context of this disclosure, all thermal analyses and associated definitions refer to measurements performed starting at 25° C. and ramping to 1000° C. at a ramp rate of 20° C. per minute in air at ambient pressure. Therefore, any changes in these parameters must be taken into account (or re-run under these conditions) when measuring and calculating the onset of thermal decomposition, peak temperature of heat release, peak temperature of heat absorption, etc.

[0087] Within the context of this disclosure, the terms "onset of thermal decomposition" and "TD" refer to the measurement of the lowest temperature of the ambient heat at which a rapid exothermic reaction from the decomposition of an organic material appears within a material or composition. The onset of thermal decomposition of an organic material within a material or composition can be measured using thermogravimetric analysis (TGA). The TGA curve of a material indicates the weight loss (% mass) of the material when exposed to an elevated ambient temperature, i.e., indicates thermal decomposition. The onset of thermal decomposition of a material can be correlated to the intersection of the following tangents of the TGA curve: a tangent to the baseline of the TGA curve, and a tangent to the TGA curve at the maximum slope point during the rapid exothermic decomposition event associated with the decomposition of the organic material. Within the context of this disclosure, the measurement of the onset of thermal decomposition of an organic material is obtained using TGA analysis as provided in this paragraph, unless otherwise stated.

[0088] The onset of thermal decomposition of a material may also be measured using differential scanning calorimetry (DSC) analysis. The DSC curve of a material indicates the heat energy (mW / mg) released by the material when exposed to a gradual increase in ambient temperature. The onset of thermal decomposition temperature of the material can be correlated with the point in the DSC curve where ΔmW / mg (change in thermal energy output) increases to a maximum, thus indicating exothermic heat production from the aerogel material. Within the context of this disclosure, measurements of the onset of thermal decomposition using DSC, TGA, or both are taken using a temperature ramp rate of 20° C. / min as further defined in the previous paragraph, unless otherwise stated. DSC and TGA each provide similar values ​​for this onset of thermal decomposition, and in many cases, the tests are performed simultaneously, so results are obtained from both.

[0089] Within the context of this disclosure, the terms "onset of endothermic decomposition" and "TED" refer to the measurement of the lowest temperature of the heat of the environment at which an endothermic reaction due to decomposition or dehydration appears within a material or composition. The onset of endothermic decomposition of a material or composition may be measured using thermogravimetric analysis (TGA). The TGA curve of a material indicates the weight loss (% mass) of the material when exposed to an increase in ambient temperature. The onset of thermal decomposition of a material may be correlated to the intersection of the following tangents of the TGA curve: a tangent to the baseline of the TGA curve and a tangent to the TGA curve at the maximum slope point during the rapid endothermic decomposition or dehydration of the material. Within the context of this disclosure, the measurement of the onset of endothermic decomposition of a material is obtained using TGA analysis as provided in this paragraph unless otherwise stated.

[0090] Within the context of this disclosure, the terms "furnace temperature rise" and "ΔΤR" refer to a measurement of the difference between the maximum temperature (TMAX) of a material or composition under pyrolysis conditions relative to the baseline temperature of that material or composition under pyrolysis conditions (usually the final temperature or TFIN). The furnace temperature rise is typically recorded in degrees Celsius or °C. The furnace temperature 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). Within the context of this disclosure, furnace temperature rise measurements are taken according to conditions comparable to the EN ISO 1182 standard (Reaction to fire tests for building and transport products: Non-combustibility test) unless otherwise specified. In certain embodiments, the aerogel compositions of the present disclosure can have an oven temperature rise 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 within a range between any two of these values. Within the context of compositional stability at elevated temperatures, for example, a first composition having an oven temperature rise that is lower than the oven temperature rise of a second composition is considered an improvement of the first composition relative to the second composition. It is contemplated herein that when one or more fire class additives are added, the oven temperature rise of the composition is reduced compared to a composition that does not include a fire class additive.

[0091] Within the context of this disclosure, the terms "flame time" and "TFLAME" refer to the measurement of a sustained fire of a material or composition under pyrolytic conditions, where a "sustained flame" is the duration of a flame lasting 5 seconds or more anywhere on the visible portion of the sample. Flame times are typically 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). Within the context of this disclosure, flame time measurements are taken according to conditions comparable to the EN ISO 1182 standard (Reaction to fire tests for building and transport products: Non-combustibility test), unless otherwise specified. In certain embodiments, the aerogel compositions of the present disclosure have a flame time 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 within a range between any two of these values. Within the context of this specification, for example, a first composition having a flame time that is shorter than the flame time of a second composition is considered an improvement of the first composition over the second composition. It is contemplated herein that when one or more fire class additives are added, the flame time of the composition is reduced compared to a composition that does not include any fire class additives.

[0092] Within the context of this disclosure, the terms "mass loss" and "ΔM" refer to a measurement of the amount of a material, composition, or composite that is lost or burned off under pyrolytic conditions. Mass loss is typically reported as weight percent or wt%. Mass loss of a material, composition, or composite 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). Within the context of this disclosure, mass loss measurements are taken according to conditions comparable to the EN ISO 1182 standard (Reaction to fire tests for building and transport products: Non-combustibility test), unless otherwise specified. In certain embodiments, the insulating layer or aerogel composition of the present disclosure can have a mass loss 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 within a range between any two of these values. Within the context of this specification, for example, a first composition having a mass loss less than the mass loss of a second composition is considered an improvement of the first composition over the second composition. It is contemplated herein that when one or more fire class additives are added, the mass loss of the composition is reduced compared to a composition that does not include any fire class additives.

[0093] Within the context of this disclosure, the term "peak heat release temperature" refers to the measured temperature of the ambient heat at which the exothermic heat release due to decomposition is maximum. The peak heat release temperature of a material or composition may be measured using TGA analysis, differential scanning calorimetry (DSC), or a combination thereof. DSC and TGA each provide similar values ​​for the peak heat release temperature, and in many cases, the tests are performed simultaneously, so that the results are obtained from both. In a typical DSC analysis, heat flow is plotted against increasing temperature, and the peak heat release temperature is the temperature at which the highest peak occurs in such a curve. Within the context of this disclosure, the measured value of the peak heat release temperature of a material or composition is obtained using TGA analysis as provided in this paragraph, unless otherwise specified.

[0094] In the context of endothermic materials, the term "peak heat absorption temperature" refers to the measured temperature of the environmental heat at which endothermic heat absorption due to decomposition is minimal. The peak heat absorption temperature of a material or composition may be measured using TGA analysis, differential scanning calorimetry (DSC), or a combination thereof. In a typical DSC analysis, heat flow is plotted against increasing temperature, and the peak heat absorption temperature is the temperature at which the lowest peak in such a curve occurs. Within the context of this disclosure, the measured peak heat absorption temperature of a material or composition is obtained using TGA analysis as provided in this paragraph, unless otherwise specified.

[0095] Within the context of this disclosure, the terms "low flammability" and "low flammability" refer to a material or composition that meets 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. Within the context of this disclosure, the terms "non-flammability" and "non-flammable" refer to a material or composition that meets 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. It is contemplated that the flammability of a composition (e.g., a combination of furnace temperature rise, flame time, and mass loss) is reduced upon inclusion of one or more fire class additives as described herein.

[0096] Within the context of this disclosure, the terms "low flammability" and "low flammability" refer to a low flammability material or composition having a total heat of combustion (HOC) of 3 MJ / kg or less. Within the context of this disclosure, the terms "non-flammability" and "non-flammable" refer to a non-flammability material or composition having a heat of combustion (HOC) of 2 MJ / kg or less. As described herein, it is contemplated that the HOC of a composition is reduced upon inclusion of one or more fire class additives.

[0097] Within the context of this disclosure, the term "hydrophobically bonded silicon" refers to a silicon atom in a gel or aerogel framework that contains at least one hydrophobic group covalently bonded to the silicon atom. Examples of hydrophobically bonded silicon include, but are not limited to, silicon atoms in silica groups in a gel framework formed from a gel precursor that contains at least one hydrophobic group (such as MTES or DMDS). Hydrophobically bonded silicon may also include, but is not limited to, silicon atoms in the gel framework or on the surface of the gel that have been treated with a hydrophobizing agent (e.g., HMDZ) to impart or improve hydrophobicity by incorporating additional hydrophobic groups into the composition. Hydrophobic groups in the present disclosure include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertbutyl, octyl, phenyl, or other substituted or unsubstituted hydrophobic organic groups known to those skilled in the art. Within the context of this disclosure, "hydrophobic groups", "hydrophobic organic material", and "hydrophobic organic content" specifically exclude easily hydrolyzable organosilicon-bonded alkoxy groups on the framework of the gel material, which are the product of the reaction between organic solvents and silanol groups. Groups such as these excluded can be distinguished from this hydrophobic organic content by NMR analysis. The amount of hydrophobically bonded silicon contained in the aerogel can be analyzed using NMR spectroscopy, such as CP / MAS 29Si solid-state NMR. NMR analysis of the aerogel allows the characterization and relative 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). NMR analysis can also be used to analyze the bond chemistry of the hydrophobic silicon contained in the aerogels by allowing specific types of hydrophobic silicon to be categorized into subtypes (e.g., categorizing T-type hydrophobic silicon into T1, T2, and T3 species).Specific details regarding NMR analysis of silica materials can be found in the article "Applications of Solid-State NMR to the Study of Organic / Inorganic Multicomponent Materials" by Geppi et al., particularly pages 7-9 (Appl. Spec. Rev. (2008), 44-1:1-89), which is incorporated herein by reference according to the specifically cited pages.

[0098] Characterization of hydrophobic bond silicon in CP / MAS 29Si NMR analysis can be based on the following chemical shift peaks: M1 (30-10 ppm); D1 (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 definitive. The exact chemical shift peaks that can be attributed to various silicon species in a material can depend on the specific chemical composition of the material and can generally be deciphered through routine experimentation and analysis by those skilled in the art.

[0099] Within the context of this disclosure, the term "hydrophobic organic content" or "hydrophobic material content" or "hydrophobic content" refers to the amount of hydrophobic organic material bound to the framework in an aerogel material or composition. The hydrophobic organic content of an aerogel material or composition can be expressed as a weight percent of the amount of hydrophobic organic material on the aerogel framework relative to the total amount of material in the aerogel material or composition. The hydrophobic organic content can be calculated by one of ordinary skill in the art based on the nature and relative concentrations of the materials used to make the aerogel material or composition. The hydrophobic organic content can also be measured using thermogravimetric analysis (TGA) of the material of interest, preferably in an oxygen atmosphere (although TGA in alternative gas environments is also useful). Specifically, the percentage of hydrophobic organic material in an aerogel can be correlated to the percentage of weight loss in a hydrophobic aerogel material or composition when subjected to combustion heat temperatures during TGA analysis, with adjustments made for water loss, residual solvent loss, and loss of easily hydrolyzable alkoxy groups during TGA analysis. Other alternative techniques such as differential scanning calorimetry, elemental analysis (especially carbon), chromatographic techniques, nuclear magnetic resonance spectroscopy, and other analytical techniques known to those skilled in the art may be used to measure and determine the hydrophobic content in the aerogel compositions of the present disclosure. In certain instances, a combination of known techniques may be useful or necessary in determining the hydrophobic content of the aerogel compositions of the present disclosure.

[0100] The aerogel material or composition of the present disclosure can 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 within a range between any two of these values.

[0101] The term "fuel content" refers to the total amount of combustible material in an aerogel material or composition, which can be correlated to the total percent weight loss in the aerogel material or composition when subjected to heat of combustion temperatures during TGA or TG-DSC analysis while adjusting for moisture loss. The fuel content of an aerogel material or composition can include not only the hydrophobic organic content, but also other combustible residual alcohol solvents, filler materials, reinforcing materials, and easily hydrolyzable alkoxy groups.

[0102] Within the context of this disclosure, the term "ormosil" encompasses the aforementioned materials as well as other organically modified materials, sometimes referred to as "ormocers." Ormosils are often used as coatings, and ormosil films are cast onto substrates, for example, by sol-gel processes. Other organic-inorganic hybrid aerogel examples of the present disclosure include, but are not limited to, silica-polyether, silica-PMMA, silica-chitosan, carbides, nitrides, and other combinations of the aforementioned organic and inorganic aerogel-forming compounds. Published U.S. Patent Application 20050192367 (paragraphs

[0022] -

[0038] and

[0044] -

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

[0103] Battery cell barrier The present disclosure is directed to barriers and systems including the barriers to manage thermal runaway problems in energy storage systems. An exemplary embodiment includes a barrier having at least one insulating layer and at least one compressible layer coupled to the at least one insulating layer. The compressible layer includes a pair of rigid plates and one or more spring elements disposed between the rigid plates. The present disclosure further relates to a battery module or battery pack having one or more battery cells, and a barrier disposed in thermal communication with the battery module or battery cell, respectively. Within the context of the present disclosure, the phrase "battery element" refers to a battery cell or battery module.

[0104] One or more of the insulating layers of the barriers disclosed herein can include an aerogel composition or a reinforced aerogel composition. Aerogel materials are known to have approximately 2-6 times the thermal resistance of other common types of insulators, e.g., foams, fiberglass, etc. Aerogels can enhance effective shielding and thermal insulation without substantially increasing the thickness of the insulator or adding additional weight. Aerogels are known to be a class of structures with low density, open cell structure, large surface area, and nanometer scale pore size.

[0105] Barriers including aerogel compositions according to embodiments of the present disclosure provide favorable properties of compressibility, compression recovery, and compliance. When used as a thermal barrier between cells in a battery module, the compressible layer of the barrier can provide resistance to compressive deformation to accommodate cell expansion due to decomposition and swelling of the active materials during battery charge / discharge cycles.

[0106] The present disclosure also provides a battery module or battery pack, which includes at least one battery cell and a barrier according to an embodiment disclosed herein disposed on the battery cell or battery module, e.g., on a surface of the at least one battery cell or on a surface of the battery module. For example, the battery module or battery pack has an inner surface and an outer surface. In certain embodiments, the barrier is on an inner surface of the battery module or battery pack. In certain embodiments, the barrier is on an outer surface of the battery module or battery pack. FIG. 6 shows a schematic diagram of a battery cell, a battery module, and a battery pack.

[0107] FIG. 7 shows a schematic diagram of a barrier 400 according to embodiments disclosed herein. In one embodiment, the barrier 400 includes at least one insulating layer 410 and at least one compressible layer 420 coupled to the at least one insulating layer. In an embodiment, the compressible layer includes a pair of rigid plates 422 and one or more spring elements 425 disposed between the rigid plates. The compressible layer may be coupled to the insulating layer to form the barrier layer. In an embodiment, the compressible layer is placed in contact with the insulating layer to form the barrier layer. The insulating layer may be attached to the compressible layer by an adhesive mechanism. Exemplary adhesives include, but are not limited to, aerosol adhesives, urethane-based adhesives, acrylate adhesives, hot melt adhesives, epoxies, rubber resin adhesives, polyurethane composite adhesives, and combinations thereof. In some embodiments, the insulating layer may be attached to the compressible layer by a non-adhesive mechanism, such as a mechanism selected from the group consisting of flame bonding, needling, stitching, sealing bags, rivets, buttons, clamps, wraps, braces, and combinations thereof. In some embodiments, the layers can be attached together using any combination of adhesive and non-adhesive mechanisms described above. A barrier layer, in one embodiment, is disposed between two adjacent battery cells or battery modules (collectively referred to herein as "battery elements") 430 to mitigate heat transfer between the battery elements and protect the battery elements from thermal runaway events.

[0108] In the embodiment shown in FIG. 7, the barrier 400 includes a single compressible layer 420 bonded to a single insulating layer 410. In other embodiments, multiple compressible layers and multiple insulating layers may be bonded together to form the barrier. For example, FIG. 8 shows an embodiment of a barrier 500 including an insulating layer 510 positioned between two compressible layers 520a, 520b. Each compressible layer includes at least a pair of rigid plates 522 and one or more spring elements 525 disposed between the rigid plates. The compressible layer can be placed in contact with the insulating layer to form the barrier layer. The insulating layer may be bonded to the compressible layer using an adhesive or fasteners (e.g., screws, rivets, etc.). The barrier is disposed between two adjacent battery elements 530.

[0109] Insulation layer The insulating layer of the barrier described herein serves to reliably control heat flow from heat generating components in small spaces and provide safety and prevention of flame propagation for such products in electronic, industrial and automotive technologies. An insulating layer with excellent properties in compression can be useful in addressing these needs. In many embodiments of the present disclosure, the insulating layer also functions as a flame / ignition deflector layer, either by itself or in combination with a compressible layer. For example, the insulating layer can be combined with a rigid plate of a compressible layer to provide protection for adjacent battery cells or battery modules from flame and / or hot gases as well as flame / hot gases entrained with particulate material, such as material that may be ejected from a battery cell during a thermal runaway event. In another embodiment, the insulating layer can be resistant to flame and / or hot gases as well as flame / hot gases entrained with particulate material. An insulating layer such as mica, microporous silica, or aerogel can be combined with a fire resistant layer that can function as a flame / ignition deflector layer. Insulation layers comprising aerogel as described in embodiments herein are durable, easy to handle, and have favorable resistance to heat and flame propagation while minimizing the thickness and weight of the material used, as well as favorable properties of compressibility, compression recovery, and compliance.

[0110] Aerogels are a class of porous materials having open cells that comprise a framework of interconnected structures with a corresponding network of pores integrated within the framework, and an interstitial phase within the pore network that consists primarily of a gas, such as air. Aerogels are generally characterized by low density, high porosity, large surface area, and small pore size. Aerogels can be distinguished from other porous materials by their physical and structural properties.

[0111] Thus, in some embodiments, the insulating layer of the barrier of the present disclosure comprises an aerogel. In some embodiments, the insulating layer can further comprise a material selected from the group consisting of mica, microporous silica, ceramic fibers, mineral wool, and combinations thereof. In some cases, the insulating layer lacks aerogel. In some embodiments, the insulating layer can comprise a material selected from the group consisting of mica, microporous silica, ceramic fibers, mineral wool, and combinations thereof.

[0112] 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 within a range 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 about 60 mW / mK or less, 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 within a range between any two of these values.

[0113] Insulation layers of the present disclosure, such as insulation layers comprising aerogel, can retain or increase a substantial amount of thermal conductivity (typically measured in mW / mK) under a load of up to about 5 MPa. In certain embodiments, insulation layers of the present disclosure have a thermal conductivity through the thickness dimension of the insulation 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 within a range between any two of these values, at 25° C. under a load of up to about 5 MPa. The thickness of the aerogel insulation layer can decrease as a result of the load experienced by the aerogel insulation layer. For example, the thickness of an aerogel insulation layer may 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 within a range between any two of these values, under a load in the range of about 0.50 MPa to 5 MPa. The thermal resistance of an insulation layer including aerogel may decrease as the thickness decreases, but the thermal conductivity may be retained or increased by only a limited amount.

[0114] In certain embodiments, an insulating layer of the present disclosure may have a heat of combustion of about 750 cal / g or less, about 717 cal / g or less, about 700 cal / g or less, about 650 cal / g or less, about 600 cal / g or less, about 575 cal / g or less, about 550 cal / g or less, about 500 cal / g or less, about 450 cal / g or less, about 400 cal / g or less, about 350 cal / g or less, about 300 cal / g or less, about 250 cal / g or less, about 200 cal / g or less, about 150 cal / g or less, about 100 cal / g or less, about 50 cal / g or less, about 25 cal / g or less, about 10 cal / g or less, or within a range between any two of these values. An insulating layer having an improved heat of combustion relative to another insulating layer has a lower heat of combustion value relative to a reference insulating layer. In certain embodiments of the present disclosure, the heat of combustion of an insulating layer is improved by incorporating a fire class additive into the insulating layer.

[0115] In certain embodiments, the insulating layer of the present disclosure has an onset of thermal decomposition of about 300° C. or more, about 320° C. or more, about 340° C. or more, about 360° C. or more, about 380° C. or more, about 400° C. or more, about 420° C. or more, about 440° C. or more, about 460° C. or more, about 480° C. or more, about 500° C. or more, about 515° C. or more, about 550° C. or more, about 600° C. or more, or within a range between any two of these values. Within the context of this specification, for example, a first composition having an onset of thermal decomposition higher than the onset of thermal decomposition of a second composition is considered an improvement of the first composition over the second composition. It is contemplated herein that when one or more fire class additives are added, the onset of thermal decomposition of the composition or material is increased compared to a composition without any fire class additives.

[0116] The term "flexural modulus" or "flexural modulus" is a measure of a material's stiffness / resistance to bending when a force is applied perpendicular to the long dimension of the sample, known as a three-point bend test. Flexural modulus indicates the ability of a material to bend. Flexural modulus is represented by the slope of the initial linear portion of the stress-strain curve and is calculated by dividing the change in stress by the corresponding change in strain. The ratio of stress to strain is therefore 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 unit used is megapascals (MPa or N / mm 2 ) or gigapascals (GPa or kN / mm 2 ) in U.S. 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, or about 3 MPa or less. Preferably, the insulating layer of the present disclosure, e.g., aerogel, has a flexural modulus of about 2 MPa to about 8 MPa.

[0117] In certain embodiments, the compressive modulus of an insulating layer (e.g., a layer including an aerogel) is 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 within a range between any two of these values.

[0118] Aerogel In embodiments, the insulating layer may be formed from an aerogel. The aerogel may be organic, inorganic, or a mixture thereof. In some embodiments, the aerogel comprises a silica-based aerogel. The insulating layer of the barrier may be an aerogel further comprising a reinforcing material. The reinforcing material may be any material that provides the aerogel material with resilience, compliance, or structural stability. Examples of well-known reinforcing materials include, but are not limited to, open-cell macroporous framework reinforcing materials, closed-cell macroporous framework reinforcing materials, open-cell membranes, honeycomb reinforcing materials, polymeric reinforcing materials, and fibrous reinforcing materials, such as, for example, staple fibers, woven materials, nonwoven materials, needled nonwovens, battings, webs, mats, and felts.

[0119] The reinforcing material can be selected from organic polymer-based fibers, inorganic fibers, carbon-based fibers, or combinations thereof. The inorganic fibers are selected from glass fibers, rock fibers, metal fibers, boron fibers, ceramic fibers, basalt fibers, or combinations thereof.

[0120] In some embodiments, the reinforcing material can include a reinforcing material that includes multiple layers of material. For example, multiple layers of material can be bonded together. In an exemplary embodiment, at least one of the multiple layers can include a first material and at least one other layer of the multiple layers can include a second material. The first material and the second material can have the same or different material properties. For example, the first material can be more compressible than the second material. In another example, the first material can include closed cells and the second material can include open cells.

[0121] Aerogels are described as frameworks of interconnected structures, most commonly composed of interconnected oligomeric, polymeric, or colloidal particles. Aerogel frameworks can be made from a variety of precursor materials, including inorganic precursor materials (e.g., precursors used to make silica-based aerogels); organic precursor materials (e.g., precursors used to make carbon-based aerogels); hybrid inorganic / organic precursor materials; and combinations thereof. Within the context of this disclosure, the term "amalgam aerogel" refers to an aerogel made from a combination of two or more different gel precursors, the corresponding precursors being referred to as "amalgam precursors."

[0122] Inorganic aerogel Inorganic aerogels are generally formed from metal oxide or metal alkoxide materials. The metal oxide or metal alkoxide materials can be based on the oxide or alkoxide of any metal capable of forming an oxide. Such metals include, but are not limited to, silicon, aluminum, titanium, zirconium, hafnium, yttrium, vanadium, cerium, and the like. Inorganic silica aerogels are traditionally made via hydrolysis and condensation of silica-based alkoxides (e.g., tetraethoxysilane) or via gelation of silicic acid or water glass. Other relevant inorganic precursor materials for silica-based aerogel synthesis include, but are not limited to, metal silicates such as sodium silicate or potassium silicate, alkoxysilanes, partially hydrolyzed alkoxysilanes, tetraethoxysilane (TEOS), partially hydrolyzed TEOS, condensation polymers of TEOS, tetramethoxysilane (TMOS), partially hydrolyzed TMOS, condensation polymers of TMOS, tetra-n-propoxysilane, partially hydrolyzed and / or condensation polymers of tetra-n-propoxysilane, polyethylsilicates, partially hydrolyzed polyethylsilicates, monomeric alkylalkoxysilanes, bis-trialkoxyalkyl or aryl silanes, polyhedral silsesquioxanes, or combinations thereof.

[0123] In certain embodiments of the present disclosure, prehydrolyzed TEOS, such as Silbond H-5 (SBH5, Silbond Corp), which is hydrolyzed to a water / silica ratio of about 1.9 to 2, may be used commercially or may be further hydrolyzed before being incorporated into the gelation process. Partially hydrolyzed TEOS or TMOS, such as polyethylsilicate (Silbond 40) or polymethylsilicate, may also be used commercially or may be further hydrolyzed before being incorporated into the gelation process.

[0124] Inorganic aerogels may also include gel precursors containing at least one hydrophobic group, such as alkyl metal alkoxides, cycloalkyl metal alkoxides, and aryl metal alkoxides, which may impart or improve certain properties to the gel, such as stability and hydrophobicity. Inorganic silica aerogels may specifically include hydrophobic precursors, such as alkyl silanes or aryl silanes. Hydrophobic gel precursors may be used as the primary precursor material to form the framework of the gel material. However, hydrophobic gel precursors are more commonly used as co-precursors in combination with simple metal alkoxides to form 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, and hexaethyldisilazane. Any derivatives of any of the above precursors may be used, in particular certain polymers of other chemical groups may be added or crosslinked to one or more of the above precursors.

[0125] Aerogels may also be treated to impart or improve hydrophobicity. Hydrophobization treatments can be applied to sol-gel solutions, wet gels prior to liquid extraction, or aerogels after liquid extraction. Hydrophobization treatments are common in the manufacture of metal oxide aerogels, particularly silica aerogels. Examples of hydrophobization treatments of gels are discussed in more detail below, specifically in the context of treating silica wet gels. However, the specific examples and illustrations provided herein are not intended to limit the scope of the present disclosure to any specific type of hydrophobization treatment procedure or aerogel substrate. The present disclosure includes any gel or aerogel known to one of skill in the art, as well as related methods of hydrophobization treatment of aerogels, either in wet gel or dried aerogel form.

[0126] The hydrophobization treatment is carried out by reacting hydroxyl moieties on the gel, such as silanol groups (Si-OH) present on the silica gel framework, with the functional groups of the hydrophobizing agent. The resulting reaction converts the silanol groups and the hydrophobizing agent into hydrophobic groups on the silica gel framework. The hydrophobizing agent compound can react with the hydroxyl groups on the gel according to the following reaction: RNMX4-N (hydrophobizing agent) + MOH (silanol) → MOMRN (hydrophobic group) + HX. The hydrophobization treatment can be carried out both on the outer macroscopic surface of the silica gel and on the inner pore surfaces within the porous network of the gel.

[0127] The gel can be immersed in a mixture of a hydrophobizing agent and an optional hydrophobizing treatment solvent in which the hydrophobizing agent is soluble and which is also miscible with the gel solvent in the wet gel. A wide range of hydrophobizing treatment solvents can be used, including solvents such as methanol, ethanol, isopropanol, xylene, toluene, benzene, dimethylformamide, and hexane. A hydrophobizing agent in liquid or gas form can also be directly contacted with the gel to impart hydrophobicity.

[0128] The hydrophobization treatment process may include mixing or agitation to aid in the penetration of the hydrophobizing agent into the wet gel. The hydrophobization treatment process may also include varying other conditions, such as temperature and pH, to further enhance and optimize the treatment reaction. After the reaction is complete, the wet gel is washed to remove unreacted compounds and reaction by-products.

[0129] The hydrophobizing agent for the hydrophobization treatment of aerogels is generally a compound of the formula RNMX4-N, where M is a metal, R is a hydrophobic group such as CH3, CH2CH3, CH6H6, or a similar hydrophobic alkyl, cycloalkyl, or aryl moiety, and X is a halogen, usually Cl. Specific examples of hydrophobizing agents include, but are not limited to, trimethylchlorosilane (TMCS), triethylchlorosilane (TECS), triphenylchlorosilane (TPCS), dimethylchlorosilane (DMCS), dimethyldichlorosilane (DMDCS), and the like. The hydrophobizing agent can also be of the formula Y(RM)2, where M is a metal, Y is a bridging group such as NH or O, and R is a hydrophobic group such as CH3, CH2CH3, CH6H6, or a similar hydrophobic alkyl, cycloalkyl, or aryl moiety. Specific examples of such hydrophobizing agents include, but are not limited to, hexamethyldisilazane [HMDZ] and hexamethyldisiloxane [HMDSO]. The hydrophobizing agent may further include a compound of the formula: RNMV4-N, where V is a reactive or leaving group other than halogen. Specific examples of such hydrophobizing agents include, but are not limited to, vinyltriethoxysilane and vinyltrimethoxysilane.

[0130] The hydrophobization treatment of the present disclosure may also be performed during the removal, exchange, or drying of liquid in the gel. In specific embodiments, the hydrophobization treatment may be performed in a supercritical fluid environment (such as, but not limited to, supercritical carbon dioxide) and may be combined with a drying or extraction step.

[0131] Organic aerogel Organic aerogels are generally formed from carbon-based polymer precursors. These polymeric materials include, but are not limited to, resorcinol formaldehyde (RF), polyimides, polyacrylates, polymethylmethacrylates, acrylate oligomers, polyoxyalkylenes, polyurethanes, polyphenols, polybutadienes, trialkoxysilyl-terminated polydimethylsiloxanes, polystyrenes, polyacrylonitriles, polyfurfural, melamine-formaldehyde, cresol formaldehyde, phenol-furfural, polyethers, polyols, polyisocyanates, polyhydroxybenzenes, polyvinyl alcohol dialdehyde, polycyanurates, polyacrylamides, various epoxies, agar, agarose, chitosan, and combinations thereof. As an example, organic RF aerogels are generally made from the sol-gel polymerization of resorcinol or melamine with formaldehyde under alkaline conditions.

[0132] Organic / inorganic hybrid aerogel Organic / inorganic hybrid aerogels consist primarily of (organically modified silica ("ormosil")) aerogels. These ormosil materials contain an organic component that is covalently bonded to the silica network. Ormosils are typically formed by the hydrolysis and condensation of an organically modified silane, R-Si(OX)3, with a traditional alkoxide precursor, Y(OX)4. In these formulas, X can represent, for example, CH3, C2H5, C3H7, 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, epoxide, etc. The organic component in an ormosil aerogel can also be dispersed throughout the silica network or chemically bonded to the silica network.

[0133] In certain embodiments, the aerogels of the present disclosure are inorganic silica aerogels formed primarily from prepolymerized silica precursors, preferably as oligomers, or hydrolyzed silicate esters formed from silicon alkoxides in alcohol solvents. In certain embodiments, such prepolymerized silica precursors or hydrolyzed silicate esters may be formed in situ from other precursors or silicate esters, such as alkoxysilanes or water glass. However, the present disclosure as a whole may be practiced with any other aerogel composition known to those skilled in the art and is not limited to any one precursor material or amalgam mixtures of precursor materials.

[0134] Macropores As discussed above, aerogel compositions according to embodiments of the present disclosure can include an aerogel framework containing macropores. Without being bound to any particular theory of operation, the presence of macropores within the aerogel framework can allow for compression of the aerogel composition, e.g., a reinforced aerogel composition, while maintaining or even improving thermal properties, e.g., decreasing thermal conductivity. For example, the macropores can be deformed, crushed, or otherwise reduced in size by compression of the composition, thereby allowing the thickness of the composition to decrease under load. However, as the macropores deform, they effectively become smaller pores. As a result, the pathways for heat transfer within the aerogel framework can become more tortuous as the macropores deform, thereby improving thermal properties (e.g., decreasing thermal conductivity). Within the context of the present disclosure, "mesopores" are pores having an average pore size in the range of about 2 nm to about 50 nm. Aerogel frameworks are generally mesoporous (i.e., contain pores having a mean diameter primarily in the range of about 2 nm to about 50 nm). In certain embodiments, the aerogel framework of the aerogel composition of the present disclosure can include macropores. Within the context of the present disclosure, "macropores" are pores having an average pore size greater than about 50 nm. The aerogel framework can include both macropores and mesopores. For example, at least 10% of the pore volume of the aerogel framework can be composed of macropores, at least 5% of the pore volume of the aerogel framework can be composed of macropores, at least 75% of the pore volume of the aerogel framework can be composed of macropores, at least 95% of the pore volume of the aerogel framework can be composed of macropores, or 100% of the pore volume of the aerogel framework can be composed of macropores. In some specific embodiments, the aerogel framework can be a macroporous aerogel framework such that a majority of its pore volume is composed of macropores.In some cases, the macroporous aerogel framework can also include micropores and / or mesopores. In some embodiments, the average pore size (diameter) of the pores in the aerogel framework can be greater than 50 nm, 50 nm to 5000 nm, 250 nm to 2000 nm, 500 nm to 2000 nm, 500 nm to 1400 nm, or greater than 1200 nm. In certain embodiments, the average pore size can be greater than 50 nm, 50 nm to 1000 nm, preferably 100 nm to 800 nm, and more preferably greater than 250 nm to 750 nm in diameter.

[0135] Uniform and non-uniform pore size distribution In some embodiments, the variation in pore size within the aerogel framework can be uniformly distributed throughout the aerogel framework, e.g., the average pore size can be substantially the same throughout the aerogel framework.

[0136] In other embodiments, the variation in pore size within the aerogel framework can be distributed non-uniformly throughout the aerogel framework. For example, the average pore size can be different within a particular region of the aerogel framework. In some exemplary embodiments, the average pore size can be larger within the upper surface, the lower surface, or both the upper and lower surface regions of the aerogel framework. For example, the macropores can be distributed within the composition such that the ratio of macropores to mesopores is greater at the upper surface than the lower surface, greater at the lower surface than the upper surface, or greater at both the upper and lower surfaces than in an intermediate region between the upper and lower surfaces. For another example, the macropores can be distributed within the composition such that the ratio of macropores to mesopores is 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 an intermediate region between the upper and lower surfaces. In other embodiments, the average pore size can be greater within an intermediate region between the upper and lower surfaces of the aerogel framework.

[0137] Macropore formation Macropores can be formed during the manufacture of the aerogel composition. For example, macropore formation can be induced in a gel precursor material during its transition into the gel composition. In some embodiments, macropore formation can be by inducing spinodal decomposition, for example, of a gel precursor solution. In another example, macropore formation can be induced by the addition of one or more blowing agents.

[0138] Macropores present within the resulting aerogel framework can be created by selecting processing conditions that favor the formation of macropores versus mesopores and / or micropores. The amount of macropores can be determined by a number of variables: (1) the polymerization solvent, (2) the polymerization temperature, (3) the polymer molecular weight, (4) the molecular weight distribution, (5) the copolymer composition, (6) the amount of branching, (7) the amount of crosslinking, (8) the branching method, (9) the crosslinking method, (10) the method used to form the gel, (11) the type of catalyst used to form the gel, (12) the chemical composition of the catalyst used to form the gel, (13) the amount of catalyst used to form the gel, (14) the gel formation temperature, (15) the type of gas flowing over the material during gel formation, (16) the rate at which the gas flows over the material during gel formation, (17) the pressure of the atmosphere during gel formation, (18) the removal of dissolved gas during gel formation, (19) the presence of solid additives in the resin during gel formation, (20) the amount of time of the gel formation process, (21) the substrate used to form the gel, (22) the type of solvent or solvents used at each step of the solvent exchange process, (23) the composition of the solvent or solvents used at each step of the solvent exchange process, and (24) the amount of time at which the solvent exchange process is carried out. (25) the amount of time used in each step of the solvent exchange process, (26) the flow rate of the solvent exchange solvent, (27) the type of flow rate of the solvent exchange solvent, (28) the agitation rate of the solvent exchange solvent, (29) the temperature used at each step of the solvent exchange process, (30) the ratio of the volume of the solvent exchange solvent to the volume of the part, (31) the drying method, (32) the temperature at each step during the drying process, (33) the pressure at each step of the drying process, (34) the composition of the gas used at each step of the drying process, (35) the gas flow rate at each step of the drying process, (36) the temperature of the gas at each step of the drying process, (37) the temperature of the part at each step of the drying process, (38) the presence of an enclosure around the part at each step of the drying process, (39) the type of enclosure around the part during drying, and / or (40) the solvent used at each step of the drying process. The polyfunctional amine and diamine compounds may be added as solids, neat or dissolved in a suitable solvent, either separately or together in one or more portions.In another aspect, a method of making an aerogel can include the steps of: (a) providing a multifunctional amine compound and at least one diamine compound to a solvent to form a solution; (b) providing at least one dianhydride compound to the solution of step (a) under conditions sufficient to form a branched polymer matrix solution, where the branched polymer matrix is ​​solubilized in the solution; and (c) subjecting the branched polymer matrix solution to conditions sufficient to form an aerogel having an open cell structure. Macropores present in the resulting aerogel framework can be formed by the methods described above. In one preferred, non-limiting aspect, the formation of macropores versus smaller mesopores and micropores can be controlled primarily by controlling the polymer / solvent kinetics during gel formation.

[0139] As discussed above, aerogel compositions according to embodiments of the present disclosure can include an aerogel framework and a reinforcing material, where at least a portion of the reinforcing material does not include aerogel. For example, the aerogel framework can extend partially through the thickness of the reinforcing material. In such embodiments, a portion of the reinforcing material, e.g., OCMF, fibers, or a combination thereof, can include aerogel material and a portion can be free of aerogel. 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.

[0140] Without being bound to any particular theory of operation, aerogel compositions in which at least a portion of the reinforcing material does not include aerogel can provide advantageous properties of compressibility, compression recovery, and compliance. For example, the properties of the reinforcing material can be selected to provide sufficient reinforcement and support for thermal properties in the regions that include aerogel, yet provide sufficient compressibility, compression recovery, and / or compliance in the regions that are free of aerogel. The aerogel-containing portion of the reinforced aerogel composition can be selected to provide a desired thermal conductivity, e.g., about 25 mW / m * K below the aerogel-free reinforcement portion can provide or improve desired physical properties, such as compressibility.

[0141] In some embodiments, reinforced aerogel compositions in which at least a portion of the reinforcing material is free of 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 can be less than the volume of the reinforcing material such that the precursor extends only partially through the reinforcing material. Upon drying, the resulting reinforced aerogel composition includes an aerogel framework that extends through less than the entire thickness of the reinforcing material, as described above. In other embodiments, reinforced aerogel compositions in which at least a portion of the reinforcing material is free of aerogel can be formed by removing a surface aerogel layer from the reinforced aerogel composition.

[0142] In some embodiments, reinforced aerogel compositions, where at least a portion of the reinforcement material does not include aerogel, can be formed using reinforcement materials with mixed properties throughout the thickness of the reinforcement material. For example, the reinforcement material can include multiple layers, each layer having various properties, such as differences in average pore / cell size, material composition, closed cells, open cells, surface treatment, or combinations thereof. The multiple layers can be bonded together, for example, with an adhesive, by flame bonding, or by other suitable methods or mechanisms as discussed herein. The different properties of the reinforcement material can vary the distribution of aerogel through the layers. For example, the open cell portion of the reinforcement material can include an aerogel framework while the closed cell portion remains substantially free of aerogel. Similarly, other material properties of the reinforcement material or those layers can determine the distribution of aerogel within the reinforcement material and thus within the reinforced aerogel composition.

[0143] In some exemplary embodiments, reinforced aerogel compositions 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 properties of the reinforcing material or layer or the reinforcing material control or influence the amount of precursor solution that fills that material or layer, e.g., during a casting process, to provide partial filling of the reinforcing material by the precursor solution. For example, one layer of the reinforcing material can have open cells and another layer of the reinforcing material can have closed cells. When a precursor solution is combined with such a reinforcing material, the gel precursor solution can infiltrate the open cells of that layer but not substantially infiltrate the closed cells of the other layer. When such a composition is dried, the resulting reinforced aerogel composition can include a portion that does not contain aerogel, e.g., a closed cell layer, but another portion that does contain aerogel, e.g., an open cell layer.

[0144] In some embodiments, the additives disclosed herein (e.g., heat absorbing additives, opacifying additives, flame class additives, or other additives) can be non-uniformly distributed within the reinforced aerogel composition. For example, the additive material can vary through the thickness 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 concentrated in one layer of the aerogel composite or provided as a separate layer consisting essentially of the additive adjacent to or attached to the composite. For example, the thermal control member can include a layer consisting essentially of a heat absorbing material, such as gypsum, sodium bicarbonate, magnesia-based cement. In further exemplary embodiments, the aerogel composition can also include at least one additional layer of material, either within the composition or as a facing layer. For example, the layer can be a layer selected from the group consisting of a polymer sheet, a metal sheet, a fiber sheet, a highly oriented graphite material, such as a pyrolytic graphite sheet, and a fabric sheet. In some embodiments, the facing layer can be attached to the composition, for example, by a selected adhesion mechanism. Exemplary adhesive mechanisms include, but are not limited to, aerosol adhesives, urethane-based adhesives, acrylate adhesives, hot melt adhesives, epoxies, rubber resin adhesives, polyurethane composite adhesives, and combinations thereof. In some embodiments, the facing layer can be attached to the composition by a non-adhesive mechanism. Exemplary non-adhesive mechanisms include, but are not limited to, flame bonding, needling, stitching, sealing bags, rivets, buttons, clamps, wraps, braces, and combinations thereof. In some embodiments, the facing layer can be attached to the composition using any combination of the adhesive and non-adhesive mechanisms described above.

[0145] Powder aerogel composition As discussed herein, an aerogel composition or composite can include a material that incorporates the aerogel particulates, particles, granules, beads, or powder into a solid or semi-solid material in combination with a binder, such as, for example, an adhesive, resin, cement, foam, polymer, or similar solid or solidified material. For example, an aerogel composition can include a reinforcing material, aerogel particles, and optionally a binder. In an exemplary embodiment, a slurry can be provided that includes aerogel particles and at least one type of wetting agent. For example, the aerogel particles can be coated or wetted by at least one wetting agent, such as a surfactant or dispersant. The aerogel particles can be fully wet, partially wet (e.g., surface wet), or present in the slurry. A preferred wetting agent can be volatilized to allow for proper recovery of the hydrophobicity of the hydrophobic aerogel particles. If the wetting agent remains on the surface of the aerogel particles, the remaining wetting agent can contribute to the overall thermal conductivity of the composite. Thus, a preferred wetting agent is one that is removable, for example, by volatilization with or without decomposition or other means. Generally, any wetting agent that is miscible with the aerogel can be used.

[0146] Wetting Agent Wetting agent-coated slurries or aerogels can be useful as a method to easily introduce hydrophobic aerogels into various materials, such as other water-containing fluids, slurries, adhesives, binder materials, which can be optionally cured to form solid materials, fibers, metallized fibers, staple fibers, woven materials, nonwoven materials, needled nonwovens, battings, webs, mats, felts, and combinations thereof. Aerogels wetted with at least one wetting agent, or slurries containing aerogels with at least one wetting agent, can facilitate the introduction and uniform distribution of hydrophobic aerogels. Wet processes, such as those described in U.S. Pat. Nos. 9,399,864, 8,021,583, 7,635,411, and 5,399,422 (each of which is incorporated herein by reference in its entirety), use aqueous slurries to disperse aerogel particles, fibers, and other additives. The slurry can then be dewatered to form a layer of aerogel particles, fibers, and additives, which can be dried and optionally calendared to produce an aerogel composite.

[0147] Aerogel particles and additives In other embodiments, the aerogel composition can include aerogel particles, at least one inorganic matrix material, and optionally fibers, auxiliary materials, additives, and additional inorganic binders. The inorganic matrix material can include, in some embodiments, a phyllosilicate, such as a naturally occurring phyllosilicate such as kaolin, clay, or bentonite, a synthetic phyllosilicate such as magadiite or kenyaite, or a mixture thereof. The phyllosilicate may or may not be calcined, for example, to dry the material and remove the water of crystallization. The inorganic matrix material can also include, in some embodiments, an inorganic binder, such as cement, lime, gypsum, or a suitable mixture thereof, in combination with the phyllosilicate. The inorganic matrix material can also include, in some embodiments, other inorganic additives disclosed herein, such as fire class additives, opacifying agents, or combinations thereof. Exemplary processes and aerogel compositions comprising inorganic matrix materials are disclosed in U.S. Patent Nos. 6,143,400 and 6,083,619, each of which is incorporated herein by reference in its entirety. In some embodiments, the aerogel composition can include aerogel particles coated on or absorbed within woven materials, nonwoven materials, needled nonwovens, battings, webs, mats, felts, and combinations thereof. An adhesive binder can be included in the composition. Additives such as fire class additives, opacifying agents, or combinations thereof, as disclosed herein, can also be included. Exemplary processes and aerogel compositions coated on or absorbed into textiles are disclosed in U.S. Patent Publication No. 2019 / 0264381 A1, each of which is incorporated herein by reference in its entirety.

[0148] As discussed herein, the aerogel composite can be laminated or faced with a reinforcing layer of another material, such as a facing material. In one embodiment, the present disclosure provides a multilayer laminate including at least one base layer including a reinforced aerogel composition and at least one facing layer. In one embodiment, the facing layer includes a reinforcing material. In one embodiment, the reinforced aerogel composition is reinforced by a fiber reinforcement layer or an open cell foam reinforcement layer. In one embodiment, the present disclosure provides a multilayer laminate including a base layer containing a reinforced aerogel composition and at least two facing layers containing a reinforcing material, the two facing layers being on opposing surfaces of the base layer. For example, a multilayer aerogel laminate composite can be manufactured according to the methods and materials described in U.S. Patent Application Publication No. 2007 / 0173157.

[0149] The facing layer can include a material that helps provide specific properties to the final composite structure, such as improved flexibility or reduced dust. The facing material can be rigid or flexible. The facing material can include a conductive layer or a reflective foil. For example, the facing material can include a metal or metal-deposited material. The facing material can include a nonwoven material. The facing layer can be selected to protect the insulating layer from dielectric fluids, such as hydrocarbon-based dielectric cooling fluids and fluorine-based dielectric cooling fluids. The facing layer can be disposed on a surface of the composite structure, or the reinforced aerogel composite that forms the composite structure, such as a thermal control member. The facing layer can form a continuous coating or bag around the composite structure, or the reinforced aerogel composite that forms the composite structure, such as a thermal control member. In some embodiments, one or more facing layers can encapsulate the composite structure, or the reinforced aerogel composite that forms the composite structure.

[0150] In one embodiment, the facing layer comprises a polymer sheet surrounding the insulating layer; more specifically, a polymeric material including polyester, polyethylene, polyurethane, polypropylene, polyacrylonitrile, polyamide, aramid; more specifically, a polymer such as polyethylene terephthalate, low density polyethylene, ethylene-propylene copolymer, poly(4-methyl-pentane), polytetrafluoroethylene, poly(1-butene), polystyrene, polyvinylacetatae, 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 consists essentially of an expanded polymer material, more specifically expanded polymer material containing PTFE (ePTFE), expanded polypropylene (ePP), expanded polyethylene (ePE), expanded polystyrene (ePS), or a combination thereof. In one preferred embodiment, the facing material consists essentially of an expanded polymer material. In one embodiment, the polymer sheet comprises or consists essentially of a microporous polymer material characterized by pore sizes in the range of 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.

[0151] In one embodiment, the facing layer material comprises or consists essentially of a fluoropolymer material. Within the context of this disclosure, the term "fluoropolymeric" or "fluoropolymer material" refers to a material that consists primarily of polymeric fluorocarbons. Suitable fluoropolymer facing layer materials include, but are not limited to, PTFE, including microporous polytetrafluoroethylene (PTFE) as described in U.S. Pat. No. 5,814,405, and expanded PTFE (ePTFE), such as Gore-Tex® (available from WL Gore); polyvinyl fluoride (PVF); polyvinylidene fluoride (PVDF); perfluoroalkoxy (PFA); fluorinated ethylene-propylene (FEP); polychlorotrifluoroethylene (PCTFE); ethylene tetrafluoroethylene (ETFE); polyvinylidene fluoride (PVDF); ethylene chlorotrifluoroethylene (ECTFE); and combinations thereof. In one preferred embodiment, the facing material consists essentially of a fluoropolymer material. In one preferred embodiment, the facing material consists essentially of an expanded PTFE (ePTFE) material.

[0152] In one embodiment, the facing layer material comprises or consists essentially of a non-fluoropolymer material. Within the context of this disclosure, the term "non-fluoropolymer" or "non-fluoropolymer material" refers to a material that does not contain a fluoropolymer material. Suitable non-fluoropolymer facing layer materials include, but are not limited to, aluminum-vapor-deposited Mylar; low-density polyethylene, such as Tyvek® (available from DuPont); rubber or rubber composites; non-woven materials, elastic fibers, such as spandex, nylon, lycra or elastane; and combinations thereof. In one embodiment, the facing material is a flexible facing material.

[0153] In some embodiments, the facing layer material can include automotive resins and polymers, such as those having a maximum use temperature of up to about 100° C., up to about 120° C., or up to about 150° C. For example, the facing layer material can include acrylonitrile butadiene styrene (ABS) polycarbonate ABS, polypropylene, polyurethane, polystyrene, polyethylene, polycarbonate, polyimide, polyamide, PVC, or combinations thereof. For example, the aerogel composites and thermal control members according to embodiments disclosed herein can include a layer of automotive resin or automotive polymer, a metal or metal deposited layer, and an aerogel layer.

[0154] The facing layer can be attached to the insulating layer using an adhesive suitable for fixing the inorganic or organic facing material to the reinforcing material of the base layer. Examples of adhesives that can be used in the present disclosure include, but are not limited to, cement-based adhesives, sodium silicate, latex, pressure sensitive adhesives, silicones, polystyrene, aerosol adhesives, urethanes, acrylate adhesives, hot melt adhesive systems, adhesive systems available from 3M, epoxies, rubber resin adhesives, polyurethane adhesive mixtures (such as those described in U.S. Pat. No. 4,532,316).

[0155] The facing layer can also be attached to the insulating layer using a non-adhesive material or technique suitable for fastening the inorganic or organic facing material to the reinforcing material of the base layer. Examples of non-adhesive materials or techniques that can be used in the present disclosure include, but are not limited to, heat sealing, ultrasonic stitching, RF sealing, stitching or threading, needling, sealing bags, rivets or buttons, clamps, wraps, or other non-adhesive laminate materials.

[0156] The facing layer can be attached to the insulating layer at any stage of the manufacture of the aerogel composite. In one embodiment, the facing layer is attached to the insulating layer after the sol-gel solution is infused into the base reinforcing material, but before gelling. In another embodiment, the facing layer is attached to the insulating layer after gelling following infusion of the sol-gel solution into the base reinforcing material, but before aging or drying the gel material. In yet another embodiment, the facing layer is attached to the insulating layer after aging and drying the gel material. In a preferred embodiment, the facing layer is attached to the reinforcing material of the base layer before infusing the sol-gel solution into the base reinforcing material. The facing layer can be solid and fluid impermeable.

[0157] Preferably, the facing layer is inert to the cooling fluid used to cool the battery module or battery pack. As described in more detail below, the insulating layer may be exposed to a cooling fluid (liquid or gas) that may flow through the compressible layer. To suppress or prevent chemical modification of the insulating layer, the facing layer may surround the insulating layer and be formed from a material that is inert to the cooling fluid used. For example, if a hydrocarbon-based dielectric cooling fluid is used, the facing layer may be formed from a material that is chemically inert to the hydrocarbon-based dielectric cooling fluid. Alternatively, if a fluorine-based dielectric cooling fluid is used, the facing layer may be formed from a material that is chemically inert to the fluorine-based dielectric cooling fluid.

[0158] Opacifying Agent The aerogel composition may include an opacifying agent to reduce the radiative component of heat transfer. The opacifying compound or its precursor may be dispersed in the mixture containing the gel precursor at any time prior to gel formation. Examples of opacifying compounds include, but are not limited to, boron carbide (B4C), diatomaceous earth, manganese ferrite, MnO, NiO, SnO, Ag2O, Bi2O3, carbon black, graphite, titanium oxide, iron / titanium oxide, aluminum oxide, zirconium silicate, zirconium oxide, iron(II) oxide, iron(III) oxide, manganese dioxide, iron / titanium oxide (ilmenite), chromium oxide, carbides (such as SiC, TiC, or WC), or mixtures thereof. Examples of opacifying compound precursors include, but are not limited to, TiOSO4 or TiOCl2. In some embodiments, the opacifying compound used as an additive may exclude silicon carbide whiskers or fibers. When the aerogel composition is intended for use in an electrical device, such as a battery as a barrier layer or other related application, the composition including the opacifying agent can desirably have a high dielectric strength with high volume and surface resistivity. In such embodiments, the carbon additive used as the opacifying agent can be non-conductive or modified to reduce the electrical conductivity. For example, the opacifying agent can be surface oxidized to reduce the electrical conductivity. In some embodiments, a carbonaceous additive with inherent electrical conductivity can be used as an opacifying agent in an aerogel composition intended for use in an electrical device. In such embodiments, the conductive carbonaceous additive can be used at a concentration below the percolation threshold to provide a composition with a dielectric strength suitable for use in an electrical device.

[0159] Flame Class Additives The aerogel composition may include one or more fire class additives. Within the context of this disclosure, the term "fire class additive" refers to a material that has an endothermic effect in the context of a response to a fire and that can be incorporated into the aerogel composition. In more specific embodiments, the fire class additive has an onset of endothermic decomposition (ED) of 100° C. or less that is higher than the onset of thermal decomposition (Td) of the aerogel composition in which the fire class additive is present, and in specific embodiments, also has an onset of ED of 50° C. or less that is lower than the Td of the aerogel composition in which the fire class additive is present. In other words, the ED of the fire class additive is (T d -50℃)~(T d +100℃) range:

number

[0160] Prior to, simultaneously with, or even subsequent to incorporation or mixing with the sol (e.g., silica sol prepared from alkyl silicates or water glass in various ways as understood in the art), the fire class additive can be mixed with or otherwise dispersed in a medium comprising ethanol and optionally up to 10 vol.% water. The mixture can be mixed and / or agitated as necessary to achieve a substantially uniform dispersion of the additive in the medium. Without being bound by theory, the hydrated forms of the clays referenced above and other fire class additives can be utilized to provide additional endothermic effects. For example, halloysite clay (commercially available from Applied Minerals, Inc. under the trade name DRAGONITE or simply halloysite from Imerys), kaolinite clay, is an aluminum silicate clay that, in hydrated form, has an endothermic effect by releasing water of hydration at elevated temperatures (gas dilution). As another example, carbonates in hydrated form can release carbon dioxide upon heating or elevated temperatures.

[0161] Within the context of this disclosure, the term "heat of dehydration" refers to the amount of heat required to evaporate water (and dihydroxylate, if applicable) from a material in its hydrated form when not exposed to elevated temperature. Heat of dehydration is generally expressed on a unit weight basis.

[0162] In certain embodiments, the flame class additives of the present disclosure have an onset of thermal decomposition of about 100° C. or higher, about 130° C. or higher, about 200° C. or higher, about 230° C. or higher, about 240° C. or higher, about 330° C. or higher, 350° C. or higher, about 400° C. or higher, about 415° C. or higher, about 425° C. or higher, about 450° C. or higher, about 500° C. or higher, about 550° C. or higher, about 600° C. or higher, about 650° C. or higher, about 700° C. or higher, about 750° C. or higher, about 800° C. or higher, or within a range between any two of these values. In certain embodiments, the fire class additives of the present disclosure have an onset of thermal decomposition of about 440° C. or 570° C. In certain embodiments, the fire class additives of the present disclosure have an onset of thermal decomposition that is no more than 50° C. above or below, no more than 40° C. above or below, no more than 30° C. above or below, no more than 20° C. above or below, no more than 10° C. above or below, no more than 5° C. above or below, or within a range between any two of these values, of the Td of the aerogel composition (without the fire class additive) into which the fire class additive is incorporated.

[0163] The fire class additives of the present disclosure may be used in combination with clay materials, such as, but not limited to, phyllosilicate clays (such as illite), kaolin or kaolinite (aluminum silicate; Al2Si2O5(OH)4), metakaolin, halloysite (aluminum silicate; Al2Si2O5(OH)4), endellite (aluminum silicate; Al2Si2O5(OH)4), mica (silica minerals), diaspore (aluminum oxide hydroxide; α-AlO(OH)), gibbsite (aluminum hydroxide), boehmite (aluminum oxide hydroxide; γ-AlO(OH)), montmorillonite, beidellite, pyrophyllite (aluminum silicate; Al2Si4O 10(OH)2), nontronite, bravaisite, smectite, leverierite, rectorite, celadonite, attapulgite, chloropearl, volkonskoite, allophane, racewinite, dillnite, severite, miloschite, collyrite, cimolite and newtonite. wtonite), sodium bicarbonate (NaHCO3), magnesium hydroxide (or magnesium dihydroxide, "MDH"), alumina trihydrate ("ATH"), gypsum (calcium sulfate dihydrate; CaSO4·2H2O), barlintonite (MgCO3·2H2O), nesquehonite (MgCO3·3H2O), lansfordite (MgCO3·H2O), hydromagnesite (hydrated magnesium carbonate; Mg5(CO3)4(OH)2·H2O), other carbonates, including, but not limited to, dolomite and lithium carbonate. Among the clay materials, certain embodiments of the present disclosure use clay materials having at least a partially layered structure. In certain embodiments of the present disclosure, the clay material as a fire class additive in the aerogel composition has at least some water, e.g., in a hydrated form. The additive may be in a hydrous crystalline form or may become hydrated in the manufacture / processing of the composition of the present disclosure. In certain embodiments, the fire class additives also include low melting additives that absorb heat without changing chemical composition. An example of this class is low melting glass, such as inert glass beads. Other additives that may be useful in the compositions of the present 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, low melting glass frits, ceramifiers, such as calcium silicate, or charformers, such as, but not limited to, phosphates and sulfates.In certain embodiments, additives may require special processing considerations, such as techniques to ensure that the additive is distributed evenly and does not aggregate in large amounts, causing inconsistencies in product performance. Processing techniques may include additional static and dynamic agitators, stabilizers, adjustments to processing conditions, and others known in the art.

[0164] Amount of additive The amount of additive in the aerogel compositions disclosed herein may depend on the desired properties of the composition. The amount of additive used during preparation and processing of the sol-gel composition is generally referred to as a weight percentage relative to the silica content of the sol. The amount of additive in the sol may vary from about 5 wt% to about 70 wt% by weight relative to the silica content. In certain embodiments, the amount of additive in the sol is between 10 wt% and 60 wt% relative to the silica content, and in certain preferred embodiments, between 20 wt% and 40 wt% relative to the silica content. In exemplary embodiments, the amount of additive in the sol relative to the silica content is in the range of about 5 wt% to about 20 wt%, about 10 wt% to about 20 wt%, about 10 wt% to about 30 wt%, about 10 wt% to about 20 wt%, 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, the additive may be more than one type. Also, one or more fire class additives may be present in the final aerogel composition. In some preferred embodiments including an aluminum silicate fire class additive, the additive is present in the aerogel composition within about 60-70 wt% relative to the silica content. For example, in some preferred embodiments including an aluminum silicate fire class additive such as kaolin, or a combination of an aluminum silicate fire class additive such as kaolin and alumina trihydrate ("ATH"), the total amount of additive present in the aerogel composition is about 30-40 wt% relative to the silica content. As another example, in some preferred embodiments where the additive includes silicon carbide, the total amount of additive present in the aerogel composition is about 30-40 wt% relative to the silica content, such as 35 wt%. As another example, in some preferred embodiments in which the additive comprises silicon carbide, the total amount of additive present in the aerogel composition is about 5-15 wt %, e.g., 10 wt %, relative to the silica content.

[0165] When referring to the final reinforced aerogel composition, the amount of additive is generally referred to as a weight percent of the final reinforced aerogel composition. The amount of additive in the final reinforced aerogel composition can vary from about 1% to about 50%, from about 1% to about 25%, or from about 10% to about 25% by weight of the reinforced aerogel composition. In exemplary embodiments, the amount of additive in the final reinforced aerogel composition is in the range of about 10% to about 20% by weight of the reinforced aerogel composition. In exemplary embodiments, the amount of additive in the final reinforced aerogel composition is 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 a range between any of the aforementioned percentages, as a weight percent of the composition. In certain embodiments, the amount of additive in the final reinforced aerogel composition is about 15% by weight of the reinforced aerogel composition. In certain embodiments, the amount of additive in the final reinforced aerogel composition is about 13% by weight of the reinforced aerogel composition. For example, in some preferred embodiments including additives such as silicon carbide, the total amount of additive present in the aerogel composition is about 10-20% by weight of the reinforced aerogel composition, such as about 15% by weight. As another example, in some preferred embodiments including additives such as silicon carbide, the total amount of additive present in the aerogel composition is about 3-5% by weight of the reinforced aerogel composition, such as about 4% by weight.

[0166] Initiation of pyrolysis by fire class additives In certain embodiments, the fire class additives can be classified or grouped based on their onset temperature of thermal decomposition. For example, the fire class additives can be classified or grouped as having an onset temperature of thermal decomposition less than about 200° C., less than about 400° C., or greater than about 400° C. For example, additives having an onset temperature of thermal decomposition less than about 200° C. include sodium bicarbonate (NaHCO3), nesquehonite (MgCO3·3H2O), and gypsum (calcium sulfate dihydrate; CaSO4·2H2O). As another example, additives having an onset temperature of thermal decomposition less than about 400° C. include alumina trihydrate ("ATH"), hydromagnesite (hydrated magnesium carbonate; Mg5(CO3)4(OH)2·H2O), and magnesium hydroxide (or magnesium dihydroxide, "MDH"). As another example, additives having an onset temperature of thermal decomposition less than about 400° C. include halloysite (aluminum silicate; Al2Si2O5(OH)4), kaolin or kaolinite (aluminum silicate; Al2Si2O5(OH)4), boehmite (aluminum oxide hydroxide; γ-AlO(OH)), or a high temperature phase change material (PCM).

[0167] In certain embodiments of the present disclosure, the additives in the aerogel composition include clay materials, e.g., aluminosilicate clays such as halloysite or kaolinite, in dehydrated form, e.g., metahalloysite or metakaolin. Other additives that may be useful in the compositions of the present 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, low melting point glass frits, ceramifiers, such as calcium silicate, or charformers, such as, but are not limited to, phosphates and sulfates. In certain embodiments, additives may require special processing considerations, such as techniques to ensure that the additives are distributed evenly and do not aggregate in large quantities, causing variability in product performance. Processing techniques may include additional static and dynamic agitators, stabilizers, adjustment of processing conditions, and others known in the art. One or more fire class additives may also be present in the final aerogel composition.

[0168] In certain embodiments, the inclusion of additives in the aerogel materials and compositions of the present disclosure, such as aluminosilicate clay-based materials such as halloysite or kaolin, can improve high temperature shrinkage properties. One example of a test method for high temperature shrinkage 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 tests such as these, called "heat soaks," materials are exposed to temperatures in excess of 1000°C for durations of up to 60 minutes. In certain exemplary embodiments, the aerogel materials or compositions of the present disclosure can have a high temperature shrinkage, i.e., any combination of linear shrinkage, width shrinkage, thickness shrinkage, or dimensional shrinkage, 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 within a range between any two of these values.

[0169] In some exemplary embodiments, trace amounts of alkali metals can occur in the aerogel composition due to certain basic catalysts used to catalyze the precursor reaction. Trace amounts, e.g., 100-500 ppm, of alkali, e.g., sodium or potassium, in the aerogel material can have a detrimental effect on high temperature shrinkage and heat resistance. However, without being bound to any particular mechanism or theory, aluminosilicate clay-based materials, such as halloysite or kaolin, can reduce or eliminate the effect of alkali on shrinkage and heat resistance by scavenging volatile alkali, e.g., sodium or potassium. In certain embodiments of the present disclosure, the aluminosilicate clay material is in a dehydrated form, e.g., metahalloysite or metakaolin. For example, an aerogel material or composition that includes metakaolin or metahalloysite in an amount greater than about 0.5 wt% relative to the silica content can significantly reduce the heat shrinkage and heat resistance. In exemplary embodiments, the aerogel material or composition can include metakaolin or metahalloysite in an amount in the range of about 0.5 wt% to about 3.0 wt% relative to the silica content.

[0170] Thermally Conductive Plate In an embodiment, at least one of the pair of rigid plates is a thermally conductive plate. Preferably, both rigid plates are thermally conductive plates. The thermally conductive rigid plate provides both a rigid support for the spring elements and a heat transfer surface that allows heat from adjacent battery cells or battery modules to be transferred to a flow path formed between the pair of rigid thermally conductive plates.

[0171] The thermally conductive rigid plate is formed from a thermally conductive material. The thermally conductive material can have a thermal conductivity along an in-plane dimension of at least about 200 mW / mK. The thermally conductive material can have a thermal conductivity of more than 50 W / mK, more preferably more than 100 W / mK, and even more preferably more than 200 W / mK (all measured at 25°C). The thermally conductive material can include at least one layer containing a metal, carbon, a conductive polymer, or a combination thereof. Examples of thermally conductive materials that can be used to form the thermally conductive plate include carbon fiber, graphite, silicon carbide, metals including but not limited to copper, stainless steel, aluminum, and the like, as well as combinations thereof.

[0172] In some embodiments of the above aspects, the thermally conductive plate(s) can include one or more thermally conductive layers. For example, the thermally conductive plate can include at least one layer of a thermally conductive material, or at least one layer containing a thermally conductive material, such as a layer containing a metal, carbon, a thermally conductive polymer, or a combination thereof. As used in the context of these embodiments, a thermally conductive material refers to a material, such as an aerogel composition, that has a thermal conductivity that is higher than the thermal conductivity of the insulating layer. In certain embodiments, the thermally conductive material has a thermal conductivity that is at least about one order of magnitude higher than the thermal conductivity of the aerogel composition.

[0173] Preferably, the thermally conductive plate 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.

[0174] The thickness of the thermally conductive plate may depend on a variety of factors related to the material used, the properties of the insulating layer, the amount of pressure the spring elements exert against the plate, the amount of battery cells or modules, and the amount of space available within the battery module or battery pack. Functionally, the thermally conductive layer must be thick enough to provide the desired resistance against the spring elements.

[0175] In some embodiments, the thermally conductive plate can have a thickness of about 0.010 mm, 0.025 mm, 0.05 mm, 0.07 mm, 0.10 mm, or within a range between any two of these values, with an in-plane thermal conductivity in the range of about 600 to about 1950 W / mK. In some embodiments, the thermally conductive plate can have a thickness 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 within a range between any two of these values.

[0176] In some embodiments, the thermally conductive material can be selected from a phase change material.

[0177] In some embodiments, thermal paste can be used between an insulating layer and a compressible layer, or between a battery cell or module and a compressible layer to ensure uniform and consistent thermal conduction between such layers. As used herein, thermal paste refers to a variety of materials also known as thermal compounds, thermal greases, thermal interface materials (TIMs), thermal gels, heat pastes, heat sink compounds, and heat sink pastes. For example, a thermal paste layer can be disposed between an insulating layer (e.g., an aerogel composition) and a thermally conductive plate.

[0178] Compressible Layer As mentioned above, the barrier according to the embodiment of the present disclosure provides advantageous properties of compressibility, compression recovery, and compliance, in addition to low heat transfer and fire resistance properties. When used with an insulating layer, the compressible layer can provide resistance to compressive deformation to accommodate expansion of the cells due to decomposition and swelling of the active materials during the charge / discharge cycle of the battery. During initial assembly of the battery module or battery pack, a relatively low load of 1 MPa or less is typically applied to the barrier. During use, for example, as the cells in the battery module expand or swell during the charge / discharge cycle, a load of up to about 5 MPa can be applied to the compressible layer.

[0179] In an embodiment, the compressible layer has a compressive modulus of about 1 MPa to about 12 MPa. The compressive modulus of the compressible layer is determined by a spring element disposed between rigid plates. The compressive and recovery properties of the material between the cells or battery modules and packs are important to accommodate swelling during the life cycle of the cell. In a particular embodiment, the compressible layer includes a spring element that (i) is compressible by at least 50%, preferably at least 65%, and most preferably at least 80% of its original or uncompressed thickness, and (ii) returns to at least 70%, preferably at least 75%, and most preferably at least 100% of its original or uncompressed thickness after release of compression.

[0180] Spring element The compressible layer of the barrier layer includes a pair of rigid plates and one or more spring elements disposed between the rigid plates. Within the context of this disclosure, the term "spring element" refers to any elastic object that stores mechanical energy. Compression springs are preferred springs for use as spring elements. Exemplary compression springs include, but are not limited to, constant compression springs, variable compression springs, planar compression springs, serpentine compression springs, cantilever compression springs, bow compression springs, coil compression springs, helical compression springs, conical compression springs, wave springs, and linear springs. The "spring elements" of the compressible layer may include a single type of compression spring or a combination of different types of compression springs.

[0181] The spring element is constructed of a material that provides an elastic response to pressure applied to the plate. The material can be any metallic or polymeric material that provides the desired elastic response. Preferably, the spring element is made from stainless steel. The properties of the spring element are selected to provide an appropriate amount of compressive force to the rigid plate when placed between two battery cells or two battery modules. The compressive force is selected to be sufficient to keep the rigid plate in contact with the sides of the battery cells or battery modules. The upper limit of the compressive force is determined based on the intended expansion over the operational life of the battery cells or modules. In general, it can be expected that the battery cells or modules will expand to 50% to 100% of their initial thickness.

[0182] 9A-9B show typical expansion seen in a battery cell. FIGS. 9A-9B show a pair of battery cells 430 with a barrier 400 disposed between them. At the "beginning of life" of the energy storage system shown in FIG. 9A, the battery cells have their thinnest thickness. The spring elements 425 are in their least compressed state and provide sufficient pressure to press the rigid plate 422a against the battery cell 430 and the rigid plate 422b against the insulating layer 410. As the battery cells age, they begin to expand. The "end of life" stage of the battery cell is shown in FIG. 9B. As the battery cells expand, they press against the barrier, causing the spring elements to contract to compensate for the expansion of the battery cells. In an embodiment, the barrier has an average thickness in the range of between about 5 mm and about 30 mm during the uncompressed state or at the beginning of the life of the energy storage system, and the barrier is compressible to a minimum average thickness of between about 2 mm and 10 mm at or near the end of the life of the energy storage system.

[0183] To allow the battery cells or battery modules to expand during their life, the spring elements are selected to allow the appropriate amount of expansion. This is done by selecting a spring with the correct spring constant. This can be calculated using Hooke's Law as follows: F=-kΔx where (F) is the force generated by the spring, (Δx) is the displacement (e.g., compression) of the spring from its relaxed or neutral position, and (k) is the spring constant. Prior to placement in position between two battery elements, there is no displacement on the spring element and the force (F0) is zero. To place the barrier between the battery elements, the compressible element is compressed to reduce the width of the barrier so as to sandwich the barrier between the battery elements. Once positioned between the barrier elements, the spring element exerts an initial constant load (F) proportional to the amount of displacement (compression) of the spring element. i ) against the rigid plate. As the battery expands during use, the spring becomes more compressed and this constant load increases. Therefore, the spring constant is selected to allow the battery element to expand without the spring element impeding this expansion.

[0184] The spring constant (k) can be influenced by several factors. The primary factors that affect the spring constant include, but are not limited to, (1) the wire diameter of the spring material, (2) the diameter or length of the spring element, and (3) the free length of the spring element, which represents its length when not displaced from an equilibrium state. Each of these factors can be adjusted to create one or more spring elements that provide the appropriate amount of compressive force against a rigid plate over the life of the battery element. Thus, the spring constant of the spring element is selected to press the plate against an adjacent battery element in the electrical energy storage system. The spring element is also selected to have a spring constant that allows the spring element to be compressed as an adjacent battery cell expands.

[0185] The spring elements may be attached to one or both of the rigid plates, or may be disposed between the rigid plates without being attached to one or both of the rigid plates. If attached to one or more rigid plates, the spring elements may be attached using adhesives, welding, or mechanical fasteners.

[0186] Figures 7 and 8 show embodiments of a barrier including a compressible layer (420 and 520). In the illustrated embodiment, a linear wave spring is shown as the spring element 425. Figures 10A-10B show schematic diagrams of a compressible layer with a linear wave spring. In these embodiments, the compressible layer is comprised of a pair of rigid plates 422 with a linear wave spring 425 positioned between the rigid plates. The linear wave spring may be attached to the rigid plates or may be disposed between the rigid plates without any type of attachment. A linear wave spring is also shown in Figures 9A-9B.

[0187] 11A-11B show an embodiment of a cantilever compression spring formed on a surface of a rigid plate. FIG. 11A shows a rigid plate 622 having an array of tabs 625. Each tab of the array of tabs functions as a cantilever compression spring that can be elastically deformed during the operating conditions of the barrier disposed between the battery elements. The array of tabs 625 can be formed from any metal or polymer that is elastically deformable under the operating conditions of the energy storage system. In the embodiment shown in FIG. 11B, the array of tabs is disposed on the inner surface of each of the rigid plates 622. However, it should be understood that the array of tabs can be disposed on only one of the rigid plates.

[0188] 12 illustrates an embodiment of a rigid plate 722 having dimpled compression spring elements 725. In this embodiment, a plurality of dimpled compression spring elements 725 formed from a resilient compressible material are disposed on one or both inner surfaces of the rigid plate 722. The dimpled compression spring elements may be formed from a metal or a polymer. The dimpled compression spring elements may be hollow or solid.

[0189] 13 shows an embodiment of a portion of a compressible layer 800 having a plurality of coil compression spring elements 825 disposed on a surface of a rigid plate 822. Preferably, conical compression springs are used. Conical compression springs have a profile that decreases as they are compressed. As the battery element expands, the springs compress in on themselves, allowing the battery element to expand until the conical compression spring is fully compressed. Due to the conical shape of these spring elements, the springs can be compressed until the height of the springs is equal to the width of the wire used to make the springs.

[0190] 14A-14B show an embodiment of a compressible layer 900 having a plurality of arcuate compression spring elements 925 disposed on a surface of a rigid plate 922. As shown in FIG. 14B, the arcuate compression spring elements can be metal, metallic, or polymeric straps attached at their ends to one of a pair of rigid plates and in the middle to the other of the rigid plates. During use, expansion of the battery elements deforms the arcuate shape to accommodate the increased force from the battery elements. The straps can be held in place using welding, adhesives, or fasteners. In the embodiment shown in FIG. 15A-15B, the straps can be held in place by recesses formed in the rigid plates. For example, the first rigid plate 922a can be formed with a pair of recesses 927 for each strap to receive the ends of the strap. The second rigid plate 922b is formed with a recess 929 to receive the center of the strap. The use of recesses offers several advantages. The recesses can prevent slippage or movement of the strap when a compressive force is applied to the compressible layer. Another advantage is that the recesses help keep the rigid plates aligned during compression: for example, if a lateral force is applied to one of the rigid plates, the buckle is substantially incompressible in the lateral direction and therefore can hold the plates aligned when placed within the recesses.

[0191] In use, the barrier is placed in contact with adjacent battery elements (e.g., battery cells or battery modules). The barrier preferably comprises rigid plates (e.g., thermally conductive rigid plates) that are substantially identical in size and shape to one another, for example as shown in Figures 7, 8, 9A, and 9B. The rigid plates are also in an aligned configuration such that an outer edge of one of the pair of rigid plates is substantially aligned with an outer edge of the other of the pair of rigid plates.

[0192] During use, expansion of the battery elements may increase pressure on the rigid plates, but is countered by the spring elements. If the expansion of the battery elements is uneven, for example in a location that creates asymmetric pressure on the rigid plates, the rigid plates may slide out of the aligned position. To keep the rigid plates in the aligned position, one or more guides may be positioned between the pair of rigid plates. The guides are attached to each plate and keep the plates from sliding out of the aligned position. FIG. 10B shows an embodiment of two plates 422 with a guide 427 positioned between them. The guides can be rods or bolts and are connected to each rigid plate to inhibit or prevent lateral movement of the rigid plates relative to each other. The guides 427 may also include stops 429. The stops 429 may prevent complete compression of the compressible layer. For example, during a thermal runaway event, an explosive force is applied to the compressible layer when adjacent battery cells may burst. This force may overcome the resistance of the spring elements and bring the rigid members into contact with one another. The placement of stops 429 along the guides 427 may prevent complete collapse of the compressible layer in the event extreme forces are applied against the rigid plate.

[0193] Use of barriers within battery modules or packs Lithium-ion batteries (LIBs) are considered to be 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 are a major obstacle preventing the large-scale application of LIBs. Under misuse conditions, exothermic reactions can release heat and trigger subsequent unsafe reactions. The situation becomes even worse as heat is released from the misuse of the cell, activating chain reactions that can cause catastrophic thermal runaway.

[0194] With the continuous improvement of LIBs in energy density, improving their safety is becoming increasingly urgent for the development of electric devices (e.g., electric vehicles). The mechanisms underlying the safety issues are different for various battery chemistries. The present technology focuses on creating barriers to obtain favorable thermal and mechanical properties. The barriers of the present technology ensure the stability of the LIB under normal operating modes (e.g., to withstand applied compressive stress) while providing effective heat dissipation under normal as well as thermal runaway conditions.

[0195] The barriers disclosed herein are useful for isolating, insulating and protecting battery cells or battery components of any configuration of battery, e.g., pouch cells, cylindrical cells, non-circular cells, as well as packs and modules incorporating or including any such cells. The barriers disclosed herein are useful for rechargeable batteries, e.g., lithium ion batteries, solid-state batteries, and any other energy storage device or technology where isolation, insulation and protection is required.

[0196] The cooling system may be used in combination with the barrier of the present disclosure in a battery module or battery pack. FIG. 16 shows an embodiment of a cooling system used with the barrier of the present disclosure. In FIG. 16, two battery elements (battery cells 1130) are separated by a barrier 1100 including an insulating layer 1110 and two compressible layers 1120. The compressible layers 1120 are disposed on opposite sides of the insulating layer 1110. The barrier is disposed between the battery elements 1130 and expands via a spring element to contact the battery elements. An advantage of the barrier of the present disclosure is that the compressible layers define flow paths between the rigid plates. This flow path can be used to direct a heat transfer fluid between the individual battery elements (i.e., battery cells or battery modules) as shown in FIG. 16.

[0197] To obtain optimal fluid flow through the barrier, the spring element is selected to maintain a flow path having a width between 1 mm and 5 mm over the life of the battery. For example, the flow path may have a width of 5 mm at the beginning of the life of the battery element, but may shrink to 1 mm at the end of the life of the battery element. The use of the spring element allows for the creation of a flow path while the spring is expanded, and fluid flows around and through the spring element.

[0198] In an embodiment, the power supply system may include one or more battery modules and a fluid transfer system coupled to the battery modules. A schematic diagram of the power supply system is shown in FIG. 17. The power supply system 1200 includes a battery element 1230. The battery element 1230 includes one or more battery cells arranged in a battery module or one or more battery modules arranged in a battery pack. The battery module or battery pack is sealed such that the battery element is contained within a sealed container. The battery cells or battery modules are separated by a barrier of the present disclosure. The barrier includes an insulating layer and one or two compressible layers as previously described. A flow path is defined through the compressible layer of the barrier.

[0199] The power supply system 1200 also includes a fluid transfer system, which includes a heat transfer unit 1250 and a pump 1255 for circulating a heat transfer fluid. The pump 1255 is coupled to a container that holds the battery elements 1230 via a conduit 1262. The heat transfer fluid from the pump passes through the battery elements and exits the container to a heat transfer unit 1270 via a conduit 1264. Upon being introduced into the container, the fluid passes through a compressible layer of a barrier to transfer heat between the heat transfer fluid and the battery elements. In this embodiment of the power supply system, the rigid plate of the compressible layer is preferably constructed from a thermally conductive material. In the heat transfer unit, the fluid is heated or cooled as needed before being pumped back to the pump via a conduit 1266. Exemplary fluid transfer systems for use in the power supply system are described in U.S. Pat. No. 8,663,828, U.S. Pat. No. 9,178,187, and U.S. Patent Application Publication No. 2020 / 0020998, each of which is incorporated herein by reference.

[0200] The heat transfer fluid may be heated or cooled, depending on the requirements of the system. For example, during normal use, when electrical energy is supplied to the device, the battery element generates heat. The heat transfer fluid is cooled to help remove the generated heat from the battery element. For example, the heat transfer fluid may be cooled to a temperature below the operating temperature of the battery cells to keep the battery cells cool. In other embodiments, the battery cells may need to be heated. This may be important if the battery elements are in a device that is exposed to low temperatures for long periods of time. Therefore, it may be necessary to heat the battery elements before use by passing a heated fluid (e.g., a fluid hotter than the ambient temperature) through the battery elements.

[0201] In an embodiment, a heat transfer fluid is introduced into a vessel holding the battery element, the fluid passes through the vessel and exits through an outlet coupled to conduit 1264. The fluid can be pumped into the bottom of the vessel and exits through the top of the vessel, or the fluid can be pumped into the top of the vessel and exits through the bottom of the vessel. Alternatively, the fluid can be pumped into a side of the vessel and exit through a different side of the vessel. Thus, the flow of fluid through the barrier can be horizontal (along the long side of the battery element) or vertical (top to bottom or bottom to top of the battery element).

[0202] The spring elements in the barrier may be arranged in a predetermined pattern that produces laminar or turbulent flow when in contact with the heat transfer fluid. In a preferred embodiment, turbulent flow is produced in the barrier by appropriate placement or configuration of the spring elements. The production of turbulent flow increases the amount of time that the heat transfer fluid is in contact with the battery elements. Within the context of the present disclosure, turbulent flow occurs when the flow has a Reynolds number of greater than 1000, greater than 1500, greater than 2000, greater than 2500, greater than 3000, greater than 3500, greater than 4000, greater than 4500, or greater than 5000.

[0203] FIG. 18 shows a schematic diagram of a battery module or battery pack 1300. In the case of a battery module, a plurality of battery cells 1330 are separated by a barrier 1310. In the case of a battery pack, a plurality of battery modules 1330 are separated by a barrier 1310. The barriers disclosed herein have one or more flow paths 1315 formed in a compressible layer. A manifold 1350 may be disposed inside the battery module or battery pack to optimize the flow of heat transfer fluid into the flow paths. In use, fluid from a pump is transferred to the battery module or battery pack and pumped into the manifold. The manifold includes a fluid inlet 1353 and a series of outlets 1355 aligned with the flow paths in the barrier. The heat transfer fluid is then distributed into the manifold and exits the manifold through a series of outlets. The outlets direct the heat transfer fluid into the flow paths defined in the barrier. The directed heat transfer fluid then passes through the flow paths and changes the temperature of the battery elements. The use of a manifold can help ensure that the majority of the heat transfer fluid is directed into the barrier. A vessel outlet 1360 may be located on the opposite side to allow the heat transfer fluid to exit the vessel after it has passed through the flow path.

[0204] The heat transfer fluid may be either a liquid or a gas. In an embodiment, the heat transfer fluid is a dielectric fluid. Examples of dielectric heat transfer fluids include hydrocarbon-based dielectric cooling fluids and fluorine-based dielectric cooling fluids. The preferred heat transfer fluid is a liquid heat transfer fluid. When a liquid heat transfer fluid is used, the container holding the battery elements is sealed to prevent the fluid from leaking out of the container. Depending on the type of heat transfer fluid used (e.g., a hydrocarbon fluid or a fluorine-based fluid), the facing layer may encapsulate the insulating layer to prevent degradation of the insulating layer by the heat transfer fluid.

[0205] In another embodiment, provided herein is a device or vehicle comprising a battery module or pack according to any one of the above aspects. In some embodiments, the device is a laptop computer, a PDA, a mobile phone, a tag scanner, an audio device, a video device, a display panel, a video camera, a digital camera, a desktop computer, a military portable computer, a military telephone, a laser range finder, a digital communication device, an information gathering sensor, an electronics integrated garment, a night vision device, a power tool, a calculator, a radio, a remote control appliance, a GPS device, a handheld and portable television, an automobile starter, a flashlight, a sound device, a portable heating device, a portable vacuum cleaner, or a portable medical device. In some embodiments, the vehicle is an electric car.

[0206] Certain U.S. patents, U.S. patent applications, and other materials (e.g., articles) are incorporated by reference in this patent. However, the text of such U.S. patents, U.S. patent applications, and other materials is incorporated by reference only to the extent that there is no conflict between such text and the other descriptions and drawings set forth herein. In the event of such a conflict, any such conflicting text of the U.S. patents, U.S. patent applications, and other materials so incorporated by reference is not specifically incorporated by reference into this patent.

[0207] Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Thus, this description should be interpreted merely as illustrative, with the purpose of teaching those skilled in the art the general manner of carrying out the invention. It should be understood that the forms of the invention shown and described herein should be taken as examples of embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would become apparent to those skilled in the art after having the benefit of this description of the invention. Changes may be made to the elements described herein without departing from the spirit and scope of the invention as set forth in the following claims.

Claims

1. 1. A barrier for use between battery cells in an electrical energy storage system, comprising: At least one insulating layer; and at least one compressible layer coupled to the at least one insulating layer, the compressible layer including a pair of rigid plates and one or more spring elements disposed between the rigid plates; The barrier comprising:

2. The barrier of claim 1 , wherein at least one of the pair of rigid plates is a thermally conductive plate.

3. The barrier of claim 2 , wherein the thermally conductive plate has a thermal conductivity of at least about 200 mW / mK.

4. 4. The barrier of claim 2 or 3, wherein the thermally conductive plate comprises a metal selected from aluminum, copper and stainless steel.

5. the pair of rigid plates being substantially identical in size and shape; 10. A barrier as claimed in any one of the preceding claims, wherein the pair of rigid plates are in an aligned arrangement, in which an outer edge of one of the pair of rigid plates is substantially aligned with an outer edge of the other of the pair of rigid plates.

6. A guide is positioned between the pair of rigid plates; The barrier of claim 5 , wherein the guide maintains the rigid plate in the aligned position.

7. 10. A barrier according to any one of the preceding claims, wherein the one or more spring elements comprise one or more cantilever spring elements.

8. A barrier according to any preceding claim, wherein the one or more spring elements comprise one or more coil springs.

9. A barrier according to any preceding claim, wherein the one or more spring elements comprise one or more bow springs.

10. A barrier according to any preceding claim, wherein the one or more spring elements comprise one or more wave springs.

11. 2. The barrier of any one of the preceding claims, wherein the spring element is configured to urge the rigid plate against adjacent battery cells in the electrical energy storage system.

12. 12. The barrier of claim 11, wherein the spring element has a spring constant that allows the spring element to compress as the adjacent battery cells expand during use.

13. 10. A barrier according to any one of the preceding claims, wherein the one or more springs are positioned between the rigid plates such that a flow path is formed between the rigid plates.

14. The barrier of claim 13, wherein a channel having a width between 1 mm and 5 mm is formed between the rigid plates.

15. 2. A barrier according to any one of the preceding claims, wherein the insulating layer has a thermal conductivity through a thickness dimension of the insulating layer of less than about 50 mW / m-K at 25°C and less than about 60 mW / m-K at 600°C.

16. 2. The barrier of any one of the preceding claims, wherein the insulating layer comprises an aerogel.

17. 2. A barrier according to any one of the preceding claims, wherein the insulating layer comprises a reinforcing material.

18. 20. The barrier of claim 17, wherein the reinforcing material is a fiber selected from organic polymer-based fibers, inorganic fibers, carbon-based fibers, or combinations thereof.

19. 2. The barrier of any one of the preceding claims, wherein the insulating layer comprises one or more additives, the additives being present at a level of at least about 5-20 weight percent of the aerogel.

20. 20. The barrier of claim 19, wherein the one or more additives include a fire class additive.

21. 2. A barrier according to any one of the preceding claims, wherein the insulating layer has a flexural modulus of about 2 MPa to about 8 MPa.

22. the insulating layer has a compressive resistance; 10. The barrier of any one of the preceding claims, wherein the compression resistance at 25% strain is between about 40 kPa and about 180 kPa.

23. 2. A barrier according to any one of the preceding claims, wherein the insulating layer is encapsulated by a facing layer.

24. 24. The barrier of claim 23, wherein the facing layer is inert to hydrocarbon dielectric fluids.

25. 25. A barrier according to claim 23 or 24, wherein the facing layer is inert to fluorinated dielectric fluids.

26. the barrier has an average thickness in an uncompressed state within a range between about 5 mm and about 30 mm; 10. A barrier according to any one of the preceding claims, wherein the barrier is compressible to a minimum average thickness of between about 2mm and 10mm.

27. 13. Use of a barrier according to any one of the preceding claims in a battery pack comprising a plurality of battery modules, or in a battery module comprising a plurality of battery cells, for thermally isolating said battery modules or said battery cells from each other.

28. 28. The use of claim 27, wherein a runaway event occurring within one or more battery cells or battery modules of a portion of the battery does not cause damage to battery cells or battery modules within the battery pack.

29. A plurality of battery cells; and One or more barriers according to any one of claims 1 to 26, wherein at least one barrier is disposed between adjacent battery cells; a battery module including:

30. 30. A battery comprising one or more battery modules according to claim 29 and a fluid transfer system coupled to said battery modules; The fluid transfer system directs fluid into the one or more battery modules and collects the fluid after it has passed through the one or more battery modules.

31. 31. The power system of claim 30, wherein the fluid transfer system delivers a dielectric liquid fluid into the battery modules.

32. 31. The power system of claim 30, wherein the fluid transfer system delivers a dielectric gas into the battery module.

33. The power supply system according to any one of claims 30 to 32, wherein the fluid is heated or cooled, so that the fluid heats or cools, respectively, the plurality of battery cells in the battery module.

34. 33. The power system of any one of claims 30 to 32, wherein the barrier defines a flow path between adjacent pairs of battery cells, and in use, the fluid flows through the flow path.

35. 35. The power system of claim 34, wherein at least one of the one or more battery modules further includes a manifold coupled to the fluid transfer system having one or more ports aligned with the flow paths, and wherein during use, fluid from the fluid transfer system enters the manifold, exits through one or more outlets, and enters the flow paths.

36. the fluid transfer system includes a cooling component; The power system of any one of claims 30 to 35, wherein the cooling component maintains a temperature of the fluid below an operating temperature of the battery cells.

37. A battery pack comprising a plurality of battery modules according to claim 29 and a barrier according to any one of claims 1 to 26 disposed between adjacent battery modules; and a fluid transfer system coupled to the battery pack, the fluid transfer system delivering fluid into the battery pack and collecting the fluid after it has passed through the battery pack; , a power system.

38. 38. The power system of claim 37, wherein the fluid transfer system delivers a dielectric liquid fluid into the battery pack.

39. 38. The power system of claim 37, wherein the fluid transfer system delivers a dielectric gas into the battery pack.

40. The power supply system of any one of claims 37 to 39, wherein the fluid is heated or cooled, such that the fluid heats or cools, respectively, the battery modules in the battery pack.

41. 41. The power system of any one of claims 37 to 40, wherein the barrier defines a flow path between the adjacent pairs of battery modules, and in use, the fluid flows through the flow path.

42. 42. The power system of claim 41, wherein the spring element in the barrier is disposed between the pair of rigid plates to create turbulent flow.

43. 43. The power system of claim 42 wherein the turbulent flow has a Reynolds number greater than 1000.

44. 44. The power system of any one of claims 41 to 43, wherein the battery pack includes a manifold coupled to the fluid transfer system having one or more ports aligned with the flow paths, and wherein during use, fluid from the fluid transfer system enters the manifold, exits through one or more outlets, and enters the flow paths.

45. the fluid transfer system includes a cooling component; The power system of any one of claims 37 to 44, wherein the cooling component maintains a temperature of the fluid below an operating temperature of the battery cells.

46. A device or vehicle including a power supply system according to any one of claims 37 to 45.

47. 47. The device of claim 46, wherein the device is a laptop computer, a PDA, a mobile phone, a tag scanner, an audio device, a video device, a display panel, a video camera, a digital camera, a desktop computer, a military portable computer, a military telephone, a laser ranging device, a digital communication device, an information gathering sensor, an electronics integrated garment, a night vision device, a power tool, a calculator, a radio, a remote controlled appliance, a GPS device, a handheld and portable television, an automobile starter, a flashlight, a sound device, a portable heating device, a portable vacuum cleaner, or a portable medical device.

48. 47. The vehicle of claim 46, wherein the vehicle is an electric vehicle.

Images