Materials, systems, and methods for foil encapsulation of aerogels and aerogel composites

Abstract

The present disclosure relates to materials and systems for managing thermal runaway problems in energy storage systems. Exemplary embodiments include an insulating layer that is encapsulated to form an insulating barrier. The encapsulation layer is made from a laminate film that includes a malleable layer sandwiched between an outer polymer layer and an inner polymer layer.

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 / 304,258, filed January 28, 2022 and entitled "Materials, Systems, and Methods for Foil Encapsulation of Aerogels and Aerogel Composites," and U.S. Provisional Patent Application No. 63 / 313,063, filed February 23, 2022 and entitled "Materials, Systems, and Methods for Foil Encapsulation of Aerogels and Aerogel Composites," the contents of both provisional applications are incorporated herein by reference in their entireties.

[0002] The present disclosure relates generally to materials, systems, and methods for sealing materials. In particular, the present disclosure relates to materials, systems, and methods for sealing thermal barriers used between battery cells or modules in energy storage systems. The present disclosure further relates to sealing aerogel thermal barriers. The present disclosure further relates to battery modules or packs including one or more battery cells that include a sealed thermal shield, as well as systems including those 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, or operated 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] 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, eventually leading to a catastrophe involving fire or explosion. Promoting heat dissipation and blocking the heat transfer path can be an effective measure to reduce the danger caused by thermal runaway propagation.

[0005] 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 how closely cells can be placed.

[0006] 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 standpoint, but in this approach, the ability of the insulating material to contain the heat combined with the volume of insulation required determines the upper limit of the energy density that can be achieved.

[0007] Another approach is through the use of phase change materials. These materials undergo an endothermic phase change when they reach an elevated temperature. 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 at cooling, they are combustible themselves and therefore are not useful in preventing thermal runaway once ignition occurs within the storage device.

[0008] The incorporation of intumescent materials is another solution to prevent thermal runaway cascades. These materials are designed to expand above a certain temperature, creating a charred layer that is lightweight and provides thermal insulation when needed. These materials can be effective in providing an insulating effect, but the expansion of the material must be taken into account in the design of the storage device.

[0009] Aerogel materials have also been used as thermal barriers. Aerogel thermal barriers offer many advantages over other thermal barriers. Some of these advantages include good resistance to heat and flame propagation while minimizing the thickness and weight of the material used. Aerogel thermal barriers also have favorable properties of compressibility, compressive elasticity, and compliance. Some aerogel-based thermal barriers are light weight and have low stiffness, which can make them difficult to install between battery cells, especially in a mass production environment. Additionally, aerogel thermal barriers tend to generate particulate matter (dust) that can be detrimental to the energy storage system, creating manufacturing issues.

[0010] Many different materials are available, each with many different properties, both favorable and unfavorable, and it would be advantageous to encapsulate the heat shield to provide additional protection to both the battery cell and the thermal barrier while also simplifying the manufacturing process. Summary of the Invention

[0011] It is an object of the present disclosure to obviate or mitigate at least one of the disadvantages of the conventional methods and materials described above. Provided herein are support members designed to improve sealing and handling of thermal barriers used in battery modules or battery packs.

[0012] In one aspect of the disclosure, an insulating barrier for use in an electrical energy storage system includes at least one insulating layer and an encapsulation layer at least partially surrounding the insulating layer. The encapsulation layer includes a laminate film including an outer polymer layer, a malleable layer including a malleable material, and an inner polymer layer. The inner polymer layer is in contact with the insulating layer, and the malleable layer is disposed between the outer polymer layer and the inner polymer layer.

[0013] The outer polymer layer comprises a polymer that is resistant to the dielectric heat transfer fluid in the electrical energy storage system. For example, the outer polymer layer comprises a polymer that is resistant to the heat transfer fluid selected from the group consisting of hydrocarbon fluids, ester fluids, silicone fluids, fluoroether fluids, and combinations thereof. In one aspect of the present disclosure, the outer polymer layer is made from a polymer selected from the group consisting of polyoxymethylene, acrylonitrile butadiene styrene, polyamideimide, polyamide, polycarbonate, polyester, polyetherimide, polystyrene, polysulfone, polyimide, and terephthalate.

[0014] The inner polymer layer comprises a polymer that can be heat welded to itself. For example, the inner polymer layer comprises a polyolefin polymer. In some embodiments, the inner polymer is composed of a different polymer than the polymer of the outer polymer layer.

[0015] In some embodiments, the malleable layer comprises a metal foil. In some embodiments, the malleable layer comprises a malleable polymer.

[0016] In one aspect of the present disclosure, the sealing layer further comprises an adhesive disposed between the outer polymeric layer and the malleable layer and / or between the inner polymeric layer and the malleable layer.

[0017] In one embodiment of the present disclosure, the outer polymer layer has a thickness of about 10 μm to about 100 μm. In one embodiment of the present disclosure, the malleable layer has a thickness of about 10 μm to about 100 μm. In one embodiment of the present disclosure, the inner polymer layer has a thickness of about 10 μm to about 100 μm. In one embodiment of the present disclosure, the sealing layer has a total thickness of about 30 μm to about 300 μm.

[0018] In one embodiment of the present disclosure, the insulating layer has a thermal conductivity through the thickness 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 one embodiment of the present disclosure, the insulating layer comprises an aerogel.

[0019] In one embodiment of the present disclosure, the sealing layer completely surrounds the insulating layer. In one embodiment of the present disclosure, the sealing layer is composed of two laminate films heat-sealed together. In one embodiment of the present disclosure, the sealing layer surrounds the insulating layer. The sealing layer is heat-sealed to itself to form a housing that at least partially surrounds the insulating layer.

[0020] In one aspect of the disclosure, a method of sealing an insulating layer for use between battery cells of an electrical energy storage system includes surrounding at least a portion of the insulating layer with a laminate film including an outer polymer layer, a malleable layer including a malleable material, and an inner polymer layer, where the inner polymer layer is in contact with the insulating layer and the malleable layer is disposed between the outer polymer layer and the inner polymer layer, and heat welding the laminate film to form a sealing layer, where the sealing layer at least partially surrounds the insulating layer.

[0021] In one embodiment of the present disclosure, a method for sealing an insulating layer includes covering at least a portion of the insulating layer with a first laminate film; covering at least a portion of the insulating layer with a second laminate film; and heat-welding a portion of the first laminate film to the second laminate film to form a sealing layer.

[0022] In one aspect of the disclosure, a method of sealing an insulating layer includes forming a first recess in a first laminate film, the first recess having a shape and size complementary to the insulating layer; forming a second recess in a second laminate film, the second recess having a shape and size complementary to the insulating layer. Forming the sealing layer includes disposing an insulating layer in the first recess of the first laminate film; disposing a second laminate film on the first laminate film with the second recess substantially aligned with the first recess; and heat welding a portion of the first laminate film to a portion of the second laminate film.

[0023] In one aspect of the present disclosure, in a method of sealing an insulating layer, a first recess is formed in a first laminate film, the shape and size of the first recess being complementary to the insulating layer. A second recess is formed in a second laminate film, the shape and size of the second recess being complementary to the first recess. Forming the sealing layer includes disposing an insulating layer in the first recess of the first laminate film; disposing a second laminate film on the first laminate film with the second recess substantially aligned with the first recess such that a portion of the second recess is disposed inside the first recess; and heat welding a portion of the first laminate film to a portion of the second laminate film.

[0024] In one aspect of the present disclosure, in a method of sealing an insulating layer, a first recess is formed in a first laminate film, the shape and size of the first recess being complementary to the insulating layer. A second recess is formed in a second laminate film, the shape and size of the second recess being complementary to the first recess. Forming the sealing layer includes disposing an insulating layer in the first recess of the first laminate film; disposing a second laminate film on the first laminate film with the second recess substantially aligned with the first recess such that a portion of the second recess is disposed inside the first recess; and heat welding a portion of the first laminate film to a portion of the second laminate film.

[0025] In one aspect of the disclosure, in a method of sealing an insulating layer, a first recess is formed in a first laminate film, the shape and size of the first recess being complementary to the insulating layer. A second recess is formed in the laminate film, the shape and size of the second recess being complementary to the insulating layer. Forming the sealing layer at this point includes disposing the insulating layer in the first recess of the laminate film; folding the laminate film such that the second recess of the laminate film is substantially aligned with the first recess; and heat welding a portion of the laminate film to itself.

[0026] In one aspect of the present disclosure, the extended heat-sealed portion of the laminate film is folded against one or more sides of the insulating layer.

[0027] In another aspect of the present disclosure, a battery module includes a plurality of battery cells and one or more insulation barriers disposed between adjacent battery cells, as described herein.

[0028] 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 intelligence 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.

[0029] The insulating barriers described herein can provide one or more advantages over existing thermal runaway mitigation solutions. The insulating 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 insulating 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 insulating 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.

[0030] 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]

[0031] [Figure 1A] FIG. 2 is a cross-sectional view of an insulating layer sealed with a laminate film. [Figure 1B] FIG. [Figure 1C] FIG. 2 is a side view of a laminate film having two outer polymer layers. [Figure 2A] FIG. 1 is a schematic diagram of a process for forming an encapsulating layer around an insulating layer using two laminating film sheets. [Figure 2B] FIG. 2B shows a schematic diagram of an insulating layer encapsulated with an encapsulation layer formed by the process shown in FIG. 2A. [Figure 2C] 1 shows a schematic diagram of an alternative process in which a single laminate film sheet is used to form the encapsulating layer around the insulating layer. [Figure 3A] FIG. 1 shows a schematic diagram of a process for forming an encapsulating layer around an insulating layer using two laminate film sheets, both sheets having a recess to receive the insulating layer. [Figure 3B] FIG. 3B illustrates a top view of an insulating layer encapsulated with an encapsulation layer formed by the process illustrated in FIG. 3A. [Figure 3C] FIG. 13 shows a schematic diagram of an alternative process in which a single laminate film sheet with two recesses is used to form a sealing layer around an insulating layer. [Figure 4A] FIG. 13 is a schematic diagram of an alternative process using two recessed laminate film sheets to form an encapsulating layer around an insulating layer. [Figure 4B] FIG. 4B illustrates a top view of an insulating layer encapsulated with an encapsulation layer formed by the process illustrated in FIG. 4A. [Figure 4C] FIG. 13 shows a schematic diagram of an alternative process in which a single laminate film sheet with two recesses is used to form a sealing layer around an insulating layer. [Figure 5A]1 shows a schematic diagram of an alternative process in which two laminate film sheets are used to form an encapsulating layer around an insulating layer, one sheet having an indentation while the other sheet does not. [Figure 5B] FIG. 5B illustrates a top view of an insulating layer encapsulated with an encapsulation layer formed by the process illustrated in FIG. 5A. [Figure 5C] FIG. 1 shows a schematic diagram of an alternative process in which a laminate film sheet having a single recess in one section (and no recess in the other section) is used to form an encapsulating layer around an insulating layer. [Figure 6A] 1 shows a schematic diagram of a method for folding the sealing layer. [Figure 6B] 1 shows a schematic diagram of a method for folding an encapsulation having corner notches. [Figure 6C] 1 shows a schematic diagram of a method for doubling-folding the edges of the sealing layer. [Figure 7] 1 shows a schematic diagram of depressions formed in a laminate film. [Figure 8A] 1 shows a flow chart of an assembly process for encapsulating an insulating barrier with a single laminate film. [Figure 8B] 1 shows a flow chart of an assembly process for sealing an insulating barrier with two laminate films. [Figure 9] FIG. 1 shows a schematic diagram of a battery module having an insulating barrier between battery cells.

[0032] While the invention may be susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. The drawings may not be to scale. It should be understood, however, that the drawings and detailed description are not intended to limit the invention to the particular forms disclosed, as defined in the appended claims, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] In the following detailed description of the preferred embodiments, references are made to the accompanying drawings which form a part hereof, and in which specific embodiments are shown by way of illustration and by way of 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.

[0034] The present disclosure relates to an insulating barrier and a system including the insulating barrier for managing thermal runaway issues in energy storage systems. An exemplary embodiment includes an insulating barrier including at least one insulating layer and an encapsulation layer at least partially surrounding the insulating layer.

[0035] The insulating layer can include any type of insulating layer commonly used to separate battery cells or battery modules. Exemplary insulating layers include, but are not limited to, polymer-based thermal barriers (e.g., polypropylene, polyester, polyimide, and aromatic polyamide (aramid)), phase change materials, intumescent materials, aerogel materials, mineral-based barriers (e.g., mica), and inorganic thermal barriers (e.g., fiberglass-containing barriers).

[0036] In a preferred embodiment, the insulating layer comprises an aerogel material. A description of aerogel insulating layers is provided in U.S. Patent Application Publication No. 2021 / 0167438 and U.S. Provisional Patent Application No. 63 / 218,205, both of which are incorporated herein by reference.

[0037] The insulating layer can have a thermal conductivity through its thickness 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 of any two of these values, at 25° C. and under a load of up to about 5 MPa.

[0038] Insulation layers can have many different physical properties that make it difficult to incorporate the insulation layers into a battery module or battery pack. For example, some insulation layers have a very low flexural modulus (e.g., less than 10 MPa), making the material difficult to handle and place between battery cells. In addition, materials with low flexural modulus can be difficult to manipulate, especially when using automated sealing processes. Some insulation layers tend to generate particulate matter (dust) that can have adverse effects on the energy storage system, causing manufacturing problems.

[0039] The present disclosure helps to alleviate these problems by using a sealing layer that includes a laminate film. The sealing layer surrounds at least a portion of the insulating layer. In one embodiment, the laminate film includes an outer polymer layer, a malleable layer that includes a malleable material, and an inner polymer layer. The inner polymer layer is in contact with the insulating layer. The malleable layer is disposed between the outer polymer layer and the inner polymer layer. The inner and outer polymer layers act as a barrier to prevent damage to the insulating layer from the surrounding atmosphere and fluids present in the energy storage system. The malleable layer also provides protection to the insulating layer, but it also provides additional support to the insulating layer as a rigid, yet malleable, support for the insulating layer.

[0040] An embodiment of an insulating barrier including an insulating layer encapsulated by an encapsulation layer is shown in FIG. 1A. The insulating barrier 100 includes an insulating layer 110. The insulating layer 110 is surrounded by an encapsulation layer 120. In one embodiment, the encapsulation layer is a laminate film including an outer polymer layer 122, a malleable layer 124, and an inner polymer layer 126. An enlarged side view of the laminate film is shown in FIG. 1B. When used to encapsulate an insulating layer, the inner polymer layer 126 contacts the insulating layer 110. The malleable layer 124 is disposed between the outer polymer layer 122 and the inner polymer layer 126.

[0041] In some electrical energy storage systems, a fluid transport system is coupled to the electrical energy storage system. In use, the fluid transport system passes a heat transfer fluid through the electrical energy storage system and collects the heat transfer fluid after the fluid has passed through the electrical energy storage system. The fluid transport system passes a dielectric liquid fluid or a dielectric gas through the electrical energy storage system. In some aspects, the fluid is heated or cooled such that the fluid heats or cools, respectively, components within the electrical energy storage system.

[0042] Exemplary dielectric heat transfer fluids include, but are not limited to, hydrocarbon fluids, ester fluids, silicone fluids, and fluoroether fluids. Hydrocarbon fluids that can be used to cool components of an electrical energy storage system include, but are not limited to, aromatic hydrocarbons (e.g., diethylbenzene and dibenzyltoluene) and aliphatic hydrocarbons (e.g., paraffin oil, isoparaffin oil, and polyalphaolefins). Ester fluids that can be used to cool components of an electrical energy storage system include, but are not limited to, diester and polyol ester heat transfer fluids. Silicone fluids that can be used to cool components of an electrical energy storage system include, but are not limited to, dimethylpolysiloxane, methylphenylpolysiloxane, diphenylpolysiloxane, and halogenated polysiloxane. Fluoroether fluids that can be used to cool components of an electrical energy storage device include, but are not limited to, perfluoropolyethers and hydrofluoroethers.

[0043] In one embodiment of the present disclosure, the outer polymer layer comprises a polymer that is resistant to the dielectric heat transfer fluid in an electrical energy storage system. In a particular embodiment of the present disclosure, the outer polymer layer comprises a polymer that is resistant to one or more heat transfer fluids commonly used in electrical energy storage systems. For example, the outer layer comprises a polymer that is resistant to a hydrocarbon fluid, an ester fluid, a silicone fluid, a fluoroether fluid, or any combination of these fluids. Exemplary polymers that can be used for the outer polymer layer include, but are not limited to, polyoxymethylene, acrylonitrile butadiene styrene, polyamideimide, polyamide, polycarbonate, polyester, polyetherimide, polystyrene, polysulfone, polyimide, terephthalate, or combinations thereof.

[0044] The outer polymer layer may also provide wear protection to the insulating layer. During use, external stress may cause damage to the insulating layer. When the insulating layer is damaged, the insulating properties of the insulating layer may be compromised. External stresses that may occur in an unprotected insulating layer include, but are not limited to, stresses caused by battery cell expansion, changes in ambient temperature, external impact, external rupture, and external damage to the insulating layer. In some aspects of the present disclosure, the outer polymer layer is selected from materials that protect the insulating layer from external stresses. Exemplary polymers that can be used as the outer polymer layer include, but are not limited to, polyethylene terephthalate ("PET") and oriented nylon ("ONy").

[0045] Although a single outer polymer layer is described above, it should be understood that the outer polymer layer may be composed of two or more polymer layers. Figure 1C shows an embodiment of the present disclosure including an outer layer composed of two different polymer layers 122a and 122b. When multiple outer polymer layers are used, the additional outer polymer layers may be formed of the same or different polymers. In one embodiment of the present invention, the outer polymer layer is composed of an ONy polymer layer with an overlying PET polymer layer.

[0046] 1A, the inner polymer layer 126 is in contact with the insulating layer 110. The inner polymer layer 110 at least partially surrounds the insulating layer and protects it from external chemical and mechanical damage. The insulating layer also acts as a barrier to retain particulate matter from the insulating layer contained within the encapsulation layer, blocking or preventing damaging particles from dispersing within the electrical energy storage system.

[0047] As discussed herein, the sealing layer 120 may be composed of two separate laminate films (e.g., top film 120a and bottom film 120b) that are connected together to form a seal around the insulating layer 110. In an alternative embodiment, the sealing layer may be formed from a single laminate film that seals the insulating layer, which is folded and sealed back onto itself.

[0048] In one embodiment, the inner polymer layer 126 comprises a material that can be heat welded to itself. As shown in FIG. 1A, after sealing the insulating layer 110, the sealing layer 120 expands in a direction away from the insulating layer. For example, an inner polymer layer disposed on a top surface of the insulating layer can be heat welded to an inner polymer layer disposed on a bottom surface of the insulating layer to form a seal around the insulating layer. The heat seal can be formed by applying a heated object to the top and / or bottom laminate films at a location outside the insulating layer. The heat from the heated object will raise the temperature of the polymer to a point that can melt the polymers used for the top and bottom layers. An exemplary polymer that can be used as the inner layer of the laminate film is a polyolefin polymer. Examples of polyolefin polymers that can be used as the inner polymer layer include, but are not limited to, polyethylene and polypropylene.

[0049] The inner polymer layer may also provide chemical and / or thermal resistance to the insulating layer. During use, the power demand of the battery module may increase the temperature of the battery cells. Similarly, as the power demand of the battery pack increases, the temperature of the battery module may increase. As the temperature of the components separated by the insulating layer increases, the insulating layer may be stressed. Furthermore, leakage of chemicals from the battery cells may chemically damage the insulating layer and impair its thermal properties. In some aspects of the invention, the inner polymer layer is selected from materials that protect the insulating layer from chemical and thermal damage. Polyolefin polymers provide the insulating layer with excellent chemical and thermal resistance.

[0050] In one embodiment, the malleable layer 124 is disposed between the inner polymer layer 126 and the outer polymer layer 122. The malleable layer is used in some embodiments to provide support and protection for the insulating barrier. For example, an insulating layer including a woven or non-woven fiber reinforced support. Such support-based insulating layers can be difficult to install in an electrical energy storage system, especially between battery cells, due to their light weight and low stiffness. In a mass production environment, these problems are exacerbated. Disposing the malleable layer in the sealing layer can act as a support to facilitate handling of the insulating barrier during manufacturing.

[0051] The malleable layer may also provide additional thermal and mechanical protection when used in a battery module. In some aspects of the present disclosure, an insulating barrier is disposed between battery cells in a battery module. During a thermal runaway event, a battery cell may explode and release hot particles and gases throughout the module. These releases may cause damage to the cases of adjacent battery cells and potentially cause adjacent battery cells to go into a runaway state. An insulating barrier including a malleable layer may inhibit or prevent particulate matter and gases from damaging adjacent battery cells. The malleable layer may also protect the insulating layer from moisture and air.

[0052] In one aspect, the malleable layer comprises a malleable polymer or a malleable metal foil. Aluminum is the most common metal used in laminate sealing layers, although other malleable metal foils such as stainless steel and copper foil can also be used.

[0053] The use of metal foil can also add heat transfer properties to the insulation barrier. When thermal runaway of a battery cell occurs, the battery cell becomes very hot. This heat can be radiated to adjacent battery cells, increasing the likelihood that the adjacent battery cells will go into a runaway state. The use of metal foil can improve the thermal properties of the insulation barrier by providing a thermally conductive metal foil to the insulation layer. Heat generated by an adjacent runaway battery cell can be transferred to the metal foil layer. The metal foil layer can be connected to a portion of the case (e.g., a cooling plate) that allows heat to be transferred through the metal foil in a direction away from the battery cell.

[0054] As discussed herein, the sealing layer is comprised of a laminate structure including an outer polymer layer, an inner polymer layer, and a malleable layer disposed between the polymer layers. In some aspects, the inner polymer layer is comprised of a different polymeric material than the polymeric layer of the outer polymer layer. For example, the inner polymer layer can be comprised of a material that can be easily melted, while the outer polymer layer can be comprised of a material that is resistant to the coolants used in electrical energy storage systems.

[0055] The laminate film used as the sealing layer can be constructed as a single film composed of multiple layers, as described herein. In one embodiment, the laminate film can be formed by placing a malleable layer between two polymer layers and using heat and / or pressure to melt the inner and outer polymer layers. In another embodiment, adhesive or tape can be used to hold the layers together. For example, adhesive can be placed between the outer polymer layer and the malleable layer and / or between the inner polymer layer and the malleable layer.

[0056] In one embodiment, the thickness of the sealing layer is about 30 μm to about 300 μm. The sealing layer can have a thickness of up to about 30 μm, up to about 40 μm, up to about 50 μm, up to about 60 μm, up to about 70 μm, up to about 80 μm, up to about 90 μm, up to about 100 μm, up to about 120 μm, up to about 150 μm, up to about 200 μm, up to about 250 μm, or up to about 300 μm. When the sealing layer is a laminate film, the inner polymer layer can have a thickness of about 10 μm to about 100 μm; the malleable layer can have a thickness of about 10 μm to about 100 μm; and the outer polymer layer can have a thickness of about 10 μm to about 100 μm.

[0057] Insulation layers of the present disclosure, such as insulation layers comprising aerogel, may retain or slightly increase thermal conductivity (usually measured in mW / mK) under loads of up to about 5 MPa. In certain embodiments, insulation layers of the present disclosure have a thermal conductivity through the thickness 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 of any two of these values, at 25° C. and a load of up to about 5 MPa. The thickness of the aerogel insulation layer may decrease as a result of the load experienced by the aerogel insulation layer. For example, the thickness of the aerogel insulation layer may be reduced 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 any two of these values ​​under loads ranging from about 0.50 MPa to 5 MPa. The heat resistance of the insulation layer including aerogel may decrease as the thickness is reduced, but the thermal conductivity may be maintained or increased only slightly.

[0058] In one embodiment, the sealing layer completely surrounds the insulating layer. Complete sealing of the insulating layer can be achieved by heat welding two laminate films together. As used herein, the term "heat welding" refers to a process of connecting two pieces of polymeric material by fusing them with heat. In a heat welding process, one or both of the polymeric pieces are heated above the glass transition temperature of the material used to form one or both of the polymeric pieces. Heating the polymeric pieces above the glass transition temperature causes the material of one or both pieces to soften and fuse with the other piece.

[0059] In one embodiment, a method of sealing an insulating layer includes surrounding at least a portion of the insulating layer with a laminate film as described herein, and heat-sealing the laminate film to form a sealing layer, where the sealing layer at least partially surrounds the insulating layer. FIG. 2A shows one embodiment of a method of sealing an insulating layer. In this embodiment, two separate laminate films 220a and 220b each cover at least a portion of the insulating layer 210. For example, the first laminate film 220a can cover the top surface of the insulating layer, and the second laminate film 220b can cover the bottom surface of the insulating layer. Both the first and second laminate films are positioned such that the inner polymer layers are in contact with each other. The sealing layer can be formed by heat-sealing a portion of the first laminate film to the second laminate film. For example, a heating element in the overall shape of the insulating layer can be brought into contact with and pressed onto the first laminate film. The heated element melts the inner polymer layer of the first laminate film with the inner polymer layer of the second laminate film. Figure 2B shows a schematic diagram of a completely sealed insulating layer.

[0060] In another embodiment, the insulating layer is sealed by surrounding at least a portion of the insulating layer with a laminate film and heat-sealing the laminate film to form a sealing layer that at least partially surrounds the insulating layer, as described herein. FIG. 2C illustrates one embodiment of a method for sealing an insulating layer. In this embodiment, a single laminate film 225 is folded over itself such that each section of the single laminate film covers at least a portion of the insulating layer 210. For example, a first section of the laminate film 225a can cover the top surface of the insulating layer, and a second section of the laminate film 225b can cover the bottom surface of the insulating layer. Both the first and second sections of the laminate film are positioned such that the inner polymer layers are in contact with each other. The sealing layer can be formed by heat-sealing a portion of the first laminate film to the second laminate film. For example, a heating element in the overall shape of the insulating layer can be brought into contact with and pressed onto the first laminate film. The heated element causes the inner polymer layer of the first laminate film to fuse with the inner polymer layer of the second laminate film.

[0061] As shown in FIG. 3A, the method of sealing the insulating layer 310 includes forming a first recess 325 in a first laminate film 320. The first recess 325 is formed by bending the laminate film into a shape that is complementary in shape and size to the insulating layer. The presence of a malleable layer in the laminate film allows the first recess to be formed and to maintain the desired shape and size. A second recess 335 is formed in a second laminate film 330. Both the first and second laminate films are positioned such that the insulating layer is located within the recess. For example, in one embodiment, the insulating layer 310 is first placed within the second recess 335. The first laminate film 320 is then placed over the second laminate film such that the insulating layer is located within the first recess 325. The sealing layer can be completed by heat welding a portion of the first laminate film to the second laminate film. FIG. 3B shows a top view of the fully encapsulated insulating layer.

[0062] In an alternative embodiment, the sealing layer is sealed to itself. In this alternative embodiment, a single sealing layer is folded over itself and is long enough to enclose the insulating layer. Once folded over, the sealing layer is heat welded to itself to seal the insulating layer. FIG. 3C shows a schematic diagram of a method of sealing the insulating layer 310 with a sealing layer 350 comprising a single laminate film. A first recess 354 and a second recess 358 are formed in the laminate film 350. Both recesses have a size and shape complementary to the insulating layer. In this embodiment, the sealing layer is formed by placing the insulating layer 310 in the first recess 354. The laminate film is folded over itself such that the second recess 358 is substantially aligned with the first recess 354. The sealing layer can be completed by heat welding a portion of the first laminate film to the second laminate film.

[0063] An alternative method of sealing the insulating layer is shown in FIG. 4A. In this alternative embodiment, the method of sealing the insulating layer 410 includes forming a first recess 425 in a first laminate film 420. The first recess 425 is formed by bending the laminate film into a shape that is complementary in shape and size to the insulating layer. A second recess 435 is formed in a second laminate film 430. The second recess 435 has a shape and size that is complementary in shape and size to the first recess. Specifically, the second recess 435 is of a shape and size that allows the recessed portion of the second laminate film to fit into the first recess. Both the first and second laminate films are positioned such that the insulating layer is located within the first recess 425 and over the second recess 435, as shown in FIG. 4A. For example, in one embodiment, the insulating layer 410 is first placed in the first recess 425. The second laminate film 430 is then placed in contact with the first laminate film such that the insulating layer is located in the first recess 425 and over the second recess 435. The encapsulation layer can be completed by heat welding a portion of the first laminate film to the second laminate film. Figure 4B shows a top view of the fully encapsulated insulating layer.

[0064] In another aspect, a single laminate film is used to form the encapsulating insulating layer. FIG. 4C shows an embodiment in which a single laminate film 450 is folded over itself such that each section of the single laminate film covers at least a portion of the insulating layer 410. In one embodiment, a first recess 465 is formed in the first section of the laminate film. The first recess 465 is formed by bending the laminate film into a shape that is complementary in shape and size to the insulating layer. A second recess 475 is formed in the second section of the laminate film. The second recess 475 has a shape and size that is complementary in shape and size to the first recess. Specifically, the second recess 475 is of a shape and size that allows the recessed portion of the second laminate film to fit into the first recess. The first section of laminate film and the second section of laminate film are positioned such that the insulating layer is located within the first recess 465 and over the second recess 475, as shown in FIG. 4C. For example, in one embodiment, the insulating layer 410 is first positioned within the first recess 465. The second section of laminate film 450 is folded over and placed in contact with the first laminate film such that the insulating layer is located within the first recess 465 and in contact with the second recess 475. The sealing layer can be completed by heat welding a portion of the first section of laminate film to a portion of the second section of laminate film to form a sealing insulating layer.

[0065] An alternative method of sealing the insulating layer is shown in FIG. 5A. As shown in FIG. 5A, the method of sealing the insulating layer 510 includes forming a first recess 525 in a first laminate film 520. The insulating layer 510 is placed in the first recess 525. A second laminate film 530 is then placed in contact with the first laminate film such that the insulating layer is covered by the second laminate film. The sealing layer can be completed by heat welding a portion of the first laminate film to the second laminate film. FIG. 5B shows a top view of the fully sealed insulating layer.

[0066] 5C illustrates an embodiment in which a single laminate film 550 is folded over on itself such that each section of the single laminate film covers at least a portion of the insulating layer 510. As shown in FIG. 5C, a first recess 565 is formed in the first section of the laminate film 550. The insulating layer 510 is placed in the first recess 565. A second section 575 of the laminate film 550 is then placed in contact with the first section of the laminate film such that the insulating layer is covered by the second section of the laminate film. A portion of the first section of the laminate film can be heat welded to a portion of the second section of the laminate film to complete the sealing layer.

[0067] For example, after the sealing layer is formed by heat welding the laminate film(s), there may be some additional material surrounding the insulating layer, typically the portions of the sealing layer that are heat welded together. As shown in FIG. 6A, the insulating layer is sealed with the sealing layer 620. The heat welded sealing layer portions 625 extend outward from the insulating layer. This may be problematic in some energy storage systems where there is very little, if any, additional space to accommodate these extensions. In this embodiment, the extensions 625 may be folded back toward the insulating layer to reduce the size of the insulating barrier. In an alternative embodiment shown in FIG. 6B, a notch 630 may be formed in the extensions 625. The notch allows the extensions to be folded more easily without bulging material at the corners, where there may be double the material if each edge of the seal is folded toward the insulating layer. In some embodiments, a double fold may be used.

[0068] Figure 6C shows an embodiment where the edge is folded twice. In Figure 6C, an insulating layer (not shown) is sealed with a sealing layer 620. A heat sealed portion 625 of the sealing layer extends outward from the insulating layer. The first fold is a 180 degree fold where the edge material is folded over on itself. To further reduce the extended edge, the edge material is folded a second time at 90 degrees so that the edge material is folded against the side of the pouch.

[0069] When a dimple is used to form a pouch around the insulating barrier, the physical parameters of the dimple can be optimized to improve the sealing of the insulating layer. Figure 7 shows a schematic diagram of a dimple 710 formed in a laminate film 700. The dimple parameters that can be varied to improve the sealing of the insulating layer include the depth (D); length (L), and the dimple angle θ. C , and the inner edge radius θ E The coefficients can be optimized to take into account the material of the malleable layer and its thickness.

[0070] FIG. 8A shows a typical assembly process for sealing the insulating layer using a single laminate film. In a typical assembly process, both the laminate film and the insulating layer material are supplied as rolls and introduced into the assembly process. First, both the laminate film and the insulating layer material are unwound from the roll for the process. The laminate film is cut to the predetermined length required for sealing, and the necessary recesses for the process are formed in the laminate film. The insulating layer (in this example, the aerogel insulating layer) is also cut to the predetermined length required for use as a thermal barrier between battery cells or modules. The cut material is removed from the cutting machine and prepared for assembly. In this example, a single laminate sheet is used to seal the insulating layer by folding the laminate sheet onto itself. The laminate film is prepared by forming fold lines or creases in the laminate film. Next, the insulating layer (aerogel) is placed on the appropriate portion of the laminate film, and the film is prepared for heat sealing. The two sides of the laminate film are heat sealed together to partially encapsulate the insulating layer, forming a bag-like enclosure with an open end. In some embodiments, the open end of the bag is heat sealed to complete the encapsulation of the insulating layer. In an alternative embodiment, the partially encapsulated insulating layer is placed in a vacuum chamber. When a vacuum is applied to the chamber, the open end of the sealing layer is sealed to complete the complete encapsulation of the insulating layer under vacuum. The process is completed by folding the heat-sealed end of the sealing layer to the side, if necessary.

[0071] FIG. 8B shows a general assembly process for sealing the insulating layer using two laminate films. As discussed above, both the laminate film and the insulating layer material are supplied as rolls and introduced into the assembly process. First, both the laminate film and the insulating layer material are unwound from the roll for the process. The laminate film is cut into two separate pieces at the predetermined length required for sealing, and the recesses required for the process are formed in the laminate film. The insulating layer (in this example, the aerogel insulating layer) is also cut to the predetermined length required for use as a thermal barrier between battery cells or modules. The cut material is removed from the cutting machine and prepared for assembly. In this example, two laminate sheets are used to seal the insulating layer. The insulating layer (aerogel) is placed on the appropriate portion of the laminate film, and the film is prepared for heat sealing. The two sides and one end of the laminate film are heat welded together to partially encapsulate the insulating layer, forming a bag-like enclosure with an open end. In some embodiments, the open end of the bag is simply heat sealed to complete the encapsulation of the insulating layer. In one alternative embodiment, the partially sealed insulating layer is placed in a vacuum chamber. When a vacuum is applied to the chamber, the open end of the sealing layer is sealed to complete the full encapsulation of the insulating layer under vacuum. The process is completed by folding the heat sealed end of the sealing layer to the side, if necessary.

[0072] To determine the effectiveness of the insulating barrier described herein, a test protocol was developed. The test protocol tests the ability of the insulating barrier to withstand high temperatures and heated particle bombardment, which mimics the rupture conditions that may occur during thermal runaway of a battery cell. In both tests, the insulating barrier is bonded to a metal support plate (e.g., a stainless steel plate). A thermal sensor is attached to the support plate to monitor the temperature of the metal support plate during use.

[0073] To test the heat resistance of the insulating barrier, the insulating barrier is bonded to a support plate and subjected to a flame test. A propane torch (Benzomatic) is used to generate a temperature of approximately 1000° C. on the insulating barrier. During the test, the heat of the support plate can be monitored to determine the heat resistance of the insulating layer. After the flame test is completed, the insulating layer is observed for damage. In an exemplary flame test protocol, the insulating barrier is bonded to a support and a propane torch is used to heat the insulating layer at 1000° C. for 2 minutes. The insulating layer is then observed for damage.

[0074] The test protocol also includes a heated particle test. In the heated particle test, the same combustion test system is used but modified to include heated particles. In an exemplary experiment, an insulating barrier mounted on a support is heated to about 1000°C. A stream of particles inert to the operating temperature (about 1000°C) was directed at the insulating barrier such that the particles were heated with a torch before impinging on the insulating barrier. The heated particles were directed at the insulating barrier for 10 seconds. After the heated particles were stopped, the insulating barrier was heated at 1000°C without the particles for 2 minutes.

[0075] In both tests, the insulating barrier maintained its integrity and insulating properties. Under the test conditions, the polymer layer burned away, while the malleable layer (stainless steel) and insulating layer (aerogel) only discolored. The sealing member may reduce or eliminate the generation of dust or particulate matter that is shed from the insulating layer. Furthermore, the sealing layer may be formed from a material that allows marking or printing writing to be performed on the insulating barrier. Marking of the insulating layer is not always possible.

[0076] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally used in its sense including "and / or" unless the context clearly dictates otherwise.

[0077] 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 digits of the numerical value. Furthermore, the phrase "about 'x' to 'y'" includes "about 'x' to about 'y'".

[0078] Within the context of this 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, which has the following characteristics 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).

[0079] 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.

[0080] 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.

[0081] 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 insulating layer of the present disclosure can be bent at least 5°, at least 25°, at least 45°, at least 65°, or at least 85° without macroscopic failure; and / or has a bend radius of less than 4 feet, less than 2 feet, less than 1 foot, less than 6 inches, less than 3 inches, less than 2 inches, less than 1 inch, or less than U inches without macroscopic failure. Similarly, the terms "highly flexible" or "highly flexible" refer to a material that can be bent to at least 90° without macroscopic failure and / or has a bend radius of less than U inches. Additionally, the terms "classified flexibility" 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).

[0082] 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.

[0083] 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 should be 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.;

[0084] 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.

[0085] Use of isolation 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.

[0086] 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 tailoring the insulating barriers and the corresponding configuration of those tailored barriers to obtain favorable thermal and mechanical properties. The insulating barriers of the present technology ensure the stability of the LIBs under normal operating modes (e.g., to withstand applied compressive stress) while providing effective heat dissipation under normal conditions as well as thermal runaway conditions.

[0087] The insulating 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 insulating 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.

[0088] Passive devices such as cooling systems may be used in conjunction with the isolation barriers of the present disclosure within a battery module or battery pack.

[0089] Isolation barriers according to various embodiments of the present disclosure thermally isolate multiple individual battery cells or battery cell modules from one another in a battery pack that includes the individual battery cells or battery cell modules. A battery module is comprised of multiple battery cells arranged within a single housing. A battery pack is comprised of multiple battery modules. FIG. 9 illustrates an embodiment of a battery module 900 having multiple battery cells 950. A sealed isolation barrier 925 is disposed between the battery cells 950. The sealed isolation barrier may inhibit or prevent damage to adjacent battery cells if the battery cells are experiencing thermal runaway or any other catastrophic battery cell failure.

[0090] The battery modules and battery packs can be used to provide electrical energy to devices or vehicles. Devices that use the battery modules or battery packs include, but are not limited to, laptop computers, PDAs, cell phones, tag scanners, audio equipment, video equipment, display panels, video cameras, digital cameras, desktop computers, military portable computers, military telephones, laser range finders, digital communications equipment, intelligence gathering sensors, electronics-integrated clothing, night vision equipment, power tools, calculators, radios, remote control appliances, GPS devices, handheld and portable televisions, automobile starters, flashlights, sound devices, portable heating devices, portable vacuum cleaners, or portable medical devices. When used in vehicles, the battery packs can be used in fully electric or hybrid automobiles.

[0091] Aspects of the disclosure are set forth in the following numbered clauses.

[0092] 1. An isolation barrier for use in an electrical energy storage system, the isolation barrier comprising: At least one insulating layer, and and a sealing layer at least partially surrounding the insulating layer, the sealing layer comprising a laminate film including an outer polymer layer, a malleable layer comprising a malleable material, and an inner polymer layer, the inner polymer layer being in contact with the insulating layer, and the malleable layer being disposed between the outer polymer layer and the inner polymer layer.

[0093] 2. The insulating barrier of clause 1, wherein the outer polymer layer comprises a polymer that is resistant to a dielectric heat transfer fluid in the electrical energy storage system.

[0094] 3. The insulating barrier of clause 2, wherein the outer polymer layer comprises a polymer that is resistant to a heat transfer fluid selected from the group consisting of hydrocarbon fluids, ester fluids, silicone fluids, fluoroether fluids, and mixtures thereof.

[0095] 4. The insulating barrier of any one of the preceding clauses, wherein the outer polymer layer is made from a polymer selected from the group consisting of polyoxymethylene, acrylonitrile butadiene styrene, polyamideimide, polyamide, polycarbonate, polyester, polyetherimide, polystyrene, polysulfone, polyimide, and terephthalate.

[0096] 5. An insulating barrier according to any one of the preceding clauses, wherein the inner polymeric layer is comprised of a polymer capable of being heat welded to itself.

[0097] 6. The insulating barrier of any one of the preceding clauses, wherein the inner polymer layer is comprised of a polyolefin polymer.

[0098] 7. An insulating barrier according to any one of the preceding clauses, wherein the inner polymeric layer is composed of a polymer different from the polymer of the outer polymeric layer.

[0099] 8. The insulating barrier of any one of the preceding clauses, wherein the outer polymer layer is comprised of polyethylene terephthalate ("PET") or oriented nylon ("ONy") and the inner polymer layer is comprised of polypropylene ("PP").

[0100] 9. The insulating barrier of any one of the preceding clauses, wherein the outer polymer layer is comprised of a first polymer film comprised of a first material and a second polymer film comprised of a second material, the first material being different from the second material.

[0101] 10. The insulating barrier of any one of the preceding clauses, wherein the malleable layer comprises a metal foil.

[0102] 11. The insulating barrier of any one of clauses 1-10, wherein the malleable layer comprises a malleable polymer.

[0103] 12. The insulating barrier of any one of the preceding clauses, wherein the sealing layer further comprises an adhesive disposed between the outer polymeric layer and the malleable layer and / or between the inner polymeric layer and the malleable layer.

[0104] 13. The insulating barrier of any one of the preceding clauses, wherein the outer polymer layer has a thickness of about 10 μm to about 100 μm.

[0105] 14. The insulating barrier of any one of the preceding clauses, wherein the malleable layer has a thickness of about 10 μm to about 100 μm.

[0106] 15. The insulating barrier of any one of the preceding clauses, wherein the inner polymer layer has a thickness of about 10 μm to about 100 μm.

[0107] 16. The insulating barrier of any one of the preceding clauses, wherein the sealing layer has a total thickness of about 30 μm to about 300 μm.

[0108] 17. An insulating barrier according to any one of the preceding clauses, wherein the insulating layer has a thermal conductivity through the thickness of the insulating layer of less than about 50 mW / mK at 25°C and less than about 60 mW / mK at 600°C.

[0109] 18. The insulating barrier of any one of the preceding clauses, wherein the insulating layer comprises an aerogel.

[0110] 19. The insulating barrier of any one of the preceding clauses, wherein the encapsulating layer completely surrounds the insulating layer.

[0111] 20. An insulating barrier according to any one of the preceding clauses, wherein the sealing layer is made of two laminated films heat welded together.

[0112] 21. An insulating barrier as described in any one of the preceding clauses, wherein the sealing layer surrounds the insulating layer and the sealing layer is heat welded to itself to form a housing at least partially surrounding the insulating layer.

[0113] twenty two. A plurality of battery cells; and 22. A battery module comprising one or more insulating barriers according to any one of clauses 1 to 21, wherein at least one insulating barrier is disposed between adjacent battery cells.

[0114] 23. A power system comprising one or more battery modules as described in clause 22.

[0115] 24. A device or vehicle including an electrical power system as described in clause 23.

[0116] 25. The device of clause 24, 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 communications device, an intelligence gathering sensor, an article of clothing with integrated electronics, 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.

[0117] 26. A vehicle as described in clause 24, wherein the vehicle is an electric vehicle.

[0118] 27. A method of sealing an insulating layer for use between battery cells of an electrical energy storage system, the method comprising: enclosing at least a portion of the insulating layer with a laminate film including an outer polymer layer, a malleable layer including a malleable material, and an inner polymer layer, the inner polymer layer being in contact with the insulating layer and the malleable layer being disposed between the outer polymer layer and the inner polymer layer; and The method includes heat welding the laminate film to form a sealing layer, the sealing layer at least partially surrounding the insulating layer.

[0119] 28. Forming the sealing layer covering at least a portion of the insulating layer with a first laminate film; covering at least a portion of the insulating layer with a second laminate film; and a part of the first laminate film is heat-welded to the second laminate film to form the sealing layer; 28. The method according to claim 27, comprising:

[0120] 29. A first recess is formed in the first laminate film, and the shape and size of the first recess are complementary to the insulating layer; A second recess is formed in the second laminate film, the shape and size of the second recess being complementary to the insulating layer; forming the sealing layer, disposing the insulating layer in the first recess of the first laminate film; placing the second laminate film onto the first laminate film with the second recess substantially aligned with the first recess; and a part of the first laminate film is heat-welded to a part of the second laminate film; 29. The method according to claim 28, comprising:

[0121] 30. A first recess is formed in the first laminate film, and the shape and size of the first recess are complementary to the insulating layer; A second recess is formed in the second laminate film, the shape and size of the second recess being complementary to the first recess; forming the sealing layer, disposing the insulating layer in the first recess of the first laminate film; placing the second laminate film on the first laminate film with the second recess substantially aligned with the first recess such that a portion of the second recess is disposed inside the first recess; and a part of the first laminate film is heat-welded to a part of the second laminate film; 29. The method according to claim 28, comprising:

[0122] 31. A first recess is formed in the first laminate film, and the shape and size of the first recess are complementary to the insulating layer; forming the sealing layer, disposing the insulating layer in the first recess of the first laminate film; placing the second laminate film on the first laminate film; and a part of the first laminate film is heat-welded to a part of the second laminate film; 29. The method according to claim 28, comprising:

[0123] 32. A first recess is formed in the laminate film, and the shape and size of the first recess are complementary to the insulating layer; A second recess is formed in the laminate film, the shape and size of the second recess being complementary to the insulating layer; forming the sealing layer, disposing the insulating layer in the first recess of the laminate film; folding the laminate film such that the second recess in the laminate film is substantially aligned with the first recess; and heat welding a portion of the laminate film to itself; 28. The method according to claim 27, comprising:

[0124] 33. A first recess is formed in the laminate film, and the shape and size of the first recess are complementary to the insulating layer; forming the sealing layer, disposing the insulating layer in the first recess of the laminate film; folding the laminate film such that a portion of the laminate film substantially covers the insulating layer and separate portions of the laminate film; and heat welding a portion of the laminate film to itself; 28. The method according to claim 27, comprising:

[0125] 34. The method of any one of clauses 27-33, wherein the encapsulating layer completely surrounds the insulating layer.

[0126] 35. The method of any one of clauses 27-34, wherein the heat-sealed portion of the laminate film is folded against one or more sides of the insulating layer.

[0127] 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 no conflict exists 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 that are so incorporated by reference is specifically not incorporated by reference into this patent.

[0128] 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. This description is therefore to be construed as illustrative only and is intended to teach those skilled in the art the general manner of carrying out the invention. It is to be understood that the forms of the invention shown and described herein are to be construed as exemplary embodiments. Elements and materials may be substituted for those shown and described herein, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described herein without departing from the spirit and scope of the invention, as set forth in the following claims.

[0129] As used in this specification and claims, the words "comprises" and "comprising" and variations thereof mean that the specified features, steps, or integers are included. The terms should not be interpreted as excluding the presence of other features, steps, or components.

[0130] Although certain exemplary embodiments of the present invention have been described, the scope of the appended claims is not intended to be limited to only these embodiments, and the claims should be construed literally, literally, and / or equivalently.

Claims

1. 1. An isolation barrier for use in an electrical energy storage system, the isolation barrier comprising: At least one insulating layer; and and a sealing layer at least partially surrounding the insulating layer, the sealing layer comprising a laminate film including an outer polymer layer, a malleable layer comprising a malleable material, and an inner polymer layer, the inner polymer layer being in contact with the insulating layer, and the malleable layer being disposed between the outer polymer layer and the inner polymer layer.

2. The insulating barrier of claim 1 , wherein the outer polymer layer comprises a polymer that is resistant to a dielectric heat transfer fluid in the electrical energy storage system.

3. 3. The insulating barrier of claim 2, wherein the outer polymer layer comprises a polymer that is resistant to a heat transfer fluid selected from the group consisting of a hydrocarbon fluid, an ester fluid, a silicone fluid, a fluoroether fluid, and mixtures thereof.

4. 10. The insulating barrier of any one of the preceding claims, wherein the outer polymer layer is made from a polymer selected from the group consisting of polyoxymethylene, acrylonitrile butadiene styrene, polyamideimide, polyamide, polycarbonate, polyester, polyetherimide, polystyrene, polysulfone, polyimide, and terephthalate.

5. 2. An insulating barrier according to any one of the preceding claims, wherein the inner polymeric layer is comprised of a polymer capable of being heat welded to itself.

6. 2. The insulating barrier of any one of the preceding claims, wherein the inner polymeric layer is comprised of a polyolefin polymer.

7. 2. An insulating barrier according to any one of the preceding claims, wherein the inner polymeric layer is composed of a polymer different from the polymer of the outer polymeric layer.

8. 10. The insulating barrier of any one of the preceding claims, wherein the outer polymeric layer is comprised of polyethylene terephthalate ("PET") or oriented nylon ("ONy") and the inner polymeric layer is constructed of polypropylene ("PP").

9. 10. The insulating barrier of any one of the preceding claims, wherein the outer polymer layer is comprised of a first polymer film comprised of a first material and a second polymer film comprised of a second material, the first material being different from the second material.

10. 2. The insulating barrier of any one of the preceding claims, wherein the malleable layer comprises a metal foil.

11. The insulating barrier of any one of claims 1 to 10, wherein the malleable layer comprises a malleable polymer.

12. 2. The insulating barrier of any one of the preceding claims, wherein the sealing layer further comprises an adhesive disposed between the outer polymeric layer and the malleable layer and / or between the inner polymeric layer and the malleable layer.

13. 2. The insulating barrier of any one of the preceding claims, wherein the outer polymer layer has a thickness of about 10 μm to about 100 μm.

14. The insulating barrier of any one of the preceding claims, wherein the malleable layer has a thickness of about 10 μm to about 100 μm.

15. The insulating barrier of any one of the preceding claims, wherein the inner polymer layer has a thickness of about 10 μm to about 100 μm.

16. The insulating barrier of any one of the preceding claims, wherein the sealing layer has a total thickness of about 30 μm to about 300 μm.

17. 2. An insulating barrier according to any one of the preceding claims, wherein the insulating layer has a thermal conductivity through the thickness 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.

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

19. 2. The insulating barrier of any one of the preceding claims, wherein the encapsulating layer completely surrounds the insulating layer.

20. 10. An insulating barrier according to any one of the preceding claims, wherein the sealing layer is made of two laminated films heat welded together.

21. 10. An insulating barrier according to any one of the preceding claims, wherein the sealing layer surrounds the insulating layer, the sealing layer being heat welded to itself to form a housing at least partially surrounding the insulating layer.

22. A plurality of battery cells; and A battery module comprising one or more insulating barriers according to any one of claims 1 to 21, wherein at least one insulating barrier is disposed between adjacent battery cells.

23. 23. A power system comprising one or more battery modules according to claim 22.

24. 24. A device or vehicle including the power system of claim 23.

25. 25. The device of claim 24, wherein the device is a laptop computer, a PDA, a cell 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 intelligence 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.

26. 25. The vehicle of claim 24, wherein the vehicle is an electric vehicle.

27. 1. A method of sealing an insulating layer for use between battery cells of an electrical energy storage system, the method comprising: enclosing at least a portion of the insulating layer with a laminate film including an outer polymer layer, a malleable layer including a malleable material, and an inner polymer layer, the inner polymer layer being in contact with the insulating layer and the malleable layer being disposed between the outer polymer layer and the inner polymer layer; and The method includes heat welding the laminate film to form a sealing layer, the sealing layer at least partially surrounding the insulating layer.

28. forming the sealing layer, covering at least a portion of the insulating layer with a first laminate film; covering at least a portion of the insulating layer with a second laminate film; and a part of the first laminate film is thermally welded to the second laminate film to form the sealing layer; 28. The method of claim 27, comprising:

29. a first recess is formed in the first laminate film, the shape and size of the first recess being complementary to the insulating layer; a second recess is formed in the second laminate film, the shape and size of the second recess being complementary to the insulating layer; forming the sealing layer, disposing the insulating layer in the first recess of the first laminate film; placing the second laminate film onto the first laminate film with the second recess substantially aligned with the first recess; and a part of the first laminate film is heat-welded to a part of the second laminate film; 30. The method of claim 28, comprising:

30. a first recess is formed in the first laminate film, the shape and size of the first recess being complementary to the insulating layer; A second recess is formed in the second laminate film, the shape and size of the second recess being complementary to the first recess; forming the sealing layer, disposing the insulating layer in the first recess of the first laminate film; placing the second laminate film on the first laminate film with the second recess substantially aligned with the first recess such that a portion of the second recess is disposed inside the first recess; and a part of the first laminate film is heat-welded to a part of the second laminate film; 30. The method of claim 28, comprising:

31. a first recess is formed in the first laminate film, the shape and size of the first recess being complementary to the insulating layer; forming the sealing layer, disposing the insulating layer in the first recess of the first laminate film; placing the second laminate film on the first laminate film; and a part of the first laminate film is heat-welded to a part of the second laminate film; 30. The method of claim 28, comprising:

32. A first recess is formed in the laminate film, the shape and size of the first recess being complementary to the insulating layer; A second recess is formed in the laminate film, the shape and size of the second recess being complementary to the insulating layer; forming the sealing layer, disposing the insulating layer in the first recess of the laminate film; folding the laminate film such that the second recess in the laminate film is substantially aligned with the first recess; and heat welding a portion of the laminate film to itself; 28. The method of claim 27, comprising:

33. A first recess is formed in the laminate film, the shape and size of the first recess being complementary to the insulating layer; forming the sealing layer, disposing the insulating layer in the first recess of the laminate film; folding the laminate film such that a portion of the laminate film substantially covers the insulating layer and separate portions of the laminate film; and heat welding a portion of the laminate film to itself; 28. The method of claim 27, comprising:

34. The method of any one of claims 27 to 33, wherein the encapsulating layer completely surrounds the insulating layer.

35. The method of any one of claims 27 to 34, wherein the heat-sealed portion of the laminate film is folded against one or more sides of the insulating layer.

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