Materials, systems and methods for incorporating an insulating layer into the sealing layer of a pouch cell - Patents.com

Abstract

The present disclosure relates to materials and systems for managing thermal runaway issues in energy storage systems. Exemplary embodiments include an insulating layer disposed on a sealing material used to seal pouch battery cells. The sealing layer for the pouch battery cells is made from a laminate film that includes an insulating layer.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No. 63 / 316,497, entitled “MATERIALS, SYSTEMS, AND METHODS INCORPORATING AN INSULATION LAYER INTO THE ENCAPSULATING LAYER OF A POUCH CELL,” filed March 4, 2022, which is incorporated by reference in its entirety.

[0002] The present disclosure relates generally to materials, systems, and methods for incorporating an insulating layer in a sealing layer of a pouch cell. The present disclosure further relates to a battery module or battery pack including one or more battery cells having an insulating layer in a sealing layer of a pouch cell. [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. Summary of the Invention

[0010] It is an object of the present disclosure to obviate or mitigate at least one of the disadvantages of the above-mentioned conventional methods and materials. The use of an insulating layer in the sealing material of a pouch battery cell mitigates problems associated with overheating and thermal runaway of the battery cell.

[0011] Example 1 of the present disclosure includes a battery cell including battery cell components. The battery cell components include one or more cathodes, one or more anodes, and one or more separators disposed between the one or more cathodes and the one or more anodes. The battery cell further includes a sealing material that surrounds the battery cell components. The sealing layer includes an insulating layer. In some embodiments, the battery cell may be a lithium ion battery cell.

[0012] Example 2 includes the subject matter of Example 1, where the encapsulation material of the battery cell includes a laminate film including an inner polymer layer and an insulating layer disposed on the inner polymer layer, the inner polymer layer being in contact with the components of the battery cell.

[0013] Example 3 includes the subject matter of Example 1 or Example 2, where the encapsulating material includes a laminate film including an inner polymer layer, an insulating layer in contact with the inner polymer layer, and an outer polymer layer in contact with the insulating layer, the inner polymer layer in contact with a component of the battery cell, and the insulating layer disposed between the inner polymer layer and the outer polymer layer.

[0014] Example 4 includes the subject matter of any of the previous examples, wherein the encapsulating material includes a laminate film including an inner polymer layer, an insulating layer in contact with the inner polymer layer, a malleable layer in contact with the insulating layer, the malleable layer including a malleable material, and an outer polymer layer in contact with the malleable layer, wherein the inner polymer layer is in contact with a component of the battery cell, the insulating layer is disposed between the inner polymer layer and the malleable layer, and the malleable layer is disposed between the insulating layer and the outer polymer layer.

[0015] Example 5 includes the subject matter of any of the previous examples, wherein the encapsulating material includes a laminate film including an inner polymer layer, a malleable layer in contact with the inner polymer layer, the malleable layer including a malleable material, an insulating layer in contact with the malleable layer, and an outer polymer layer in contact with the insulating layer, the inner polymer layer in contact with a component of the battery cell, the malleable layer disposed between the inner polymer layer and the insulating layer, and the insulating layer disposed between the malleable layer and the outer polymer layer.

[0016] Example 6 includes the subject matter of any of the previous examples, wherein the encapsulating material includes a laminate film including an inner polymer layer, a malleable layer including a malleable material in contact with the inner polymer layer, an outer polymer layer in contact with the malleable layer, and an insulating layer in contact with the outer polymer layer, wherein the inner polymer layer is in contact with a component of the battery cell, the malleable layer is disposed between the inner polymer layer and the outer polymer layer, and the outer polymer layer is disposed between the malleable layer and the insulating layer.

[0017] Example 7 includes the subject matter of any of the previous examples, wherein the outer polymer layer includes a polymer that is resistant to a dielectric heat transfer fluid in an electrical energy storage system. For example, the outer polymer layer includes 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 combinations thereof. In one aspect of the 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. In a particular aspect of the invention, the outer polymer layer is made of polyethylene terephthalate ("PET") or oriented nylon ("ONy") and the inner polymer layer is made of polypropylene ("PP").

[0018] Example 8 includes the subject matter of any of the previous examples, wherein the inner polymer layer includes a polymer that can be heat welded to itself. For example, the inner polymer layer includes a polyolefin polymer. In some embodiments, the inner polymer is composed of a different polymer than the polymer of the outer polymer layer.

[0019] Example 9 includes the subject matter of any of the previous examples, wherein the malleable layer in some embodiments includes a metal foil. In some embodiments, the malleable layer includes a malleable polymer.

[0020] Example 10 includes the subject matter of any of the previous examples, wherein the sealing layer further includes an adhesive disposed between the outer polymeric layer and the malleable layer and / or between the inner polymeric layer and the malleable layer.

[0021] Example 11 includes the subject matter of any of the previous examples, wherein the outer polymer layer has a thickness of about 10 μm to about 100 μm. In one embodiment of the disclosure, the malleable layer has a thickness of about 10 μm to about 100 μm. In one embodiment of the disclosure, the inner polymer layer has a thickness of about 10 μm to about 100 μm.

[0022] Example 12 includes the subject matter of any of the previous examples, wherein the insulating layer has a thermal conductivity in a dimension of a 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. In one aspect of the disclosure, the insulating layer comprises an aerogel.

[0023] Examples include a battery module comprising a plurality of battery cells having an encapsulation layer including an insulating layer as described herein and including the subject matter of any of the previous examples.

[0024] In another aspect, provided herein is a device or vehicle comprising a battery module or pack according to any one of the above examples. 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 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.

[0025] The use of an insulating layer in the encapsulation material of a battery cell, including the subject matter of any of the preceding examples, described herein can provide one or more advantages over existing thermal runaway mitigation strategies. The insulating layer can minimize or eliminate thermal runaway propagation in the cell without significantly impacting the energy density and assembly cost of the battery module or pack. The insulating layer can also provide favorable compressibility, compression recovery, and compliance properties to accommodate continued battery 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 layer has favorable resistance to heat and flame propagation while minimizing the thickness and weight of the material used.

[0026] Having thus described the disclosure in general terms, reference is now made to the accompanying drawings, which are not necessarily drawn to scale. [Brief description of the drawings]

[0027] [Figure 1] FIG. 1 shows a schematic diagram of a pouch battery cell. [Diagram 2] FIG. 2 shows a cross-sectional view of a typical laminate film used to encapsulate components of a battery cell. [Figure 3A] FIG. 3A shows a top view of the battery components encapsulated by the laminate film. [Figure 3B] FIG. 3B shows a cross-sectional view of a laminate film used to encapsulate the components of a battery cell with an outer insulating layer. [Figure 4] FIG. 4 shows a cross-sectional view of a laminate film used to encapsulate components of a battery cell having an insulating layer surrounded by an inner polymer layer and an outer polymer layer. [Diagram 5] FIG. 5 shows a cross-sectional view of a laminate film used to encapsulate components of a battery cell having a malleable layer and an insulating layer surrounded by inner and outer polymer layers. [Figure 6]FIG. 6 shows a cross-sectional view of a laminate film used to encapsulate components of a battery cell having a malleable layer and an insulating layer surrounded by inner and outer polymer layers, with the insulating layer disposed between the malleable layer and the outer polymer layer. [Figure 7] FIG. 7 shows a cross-sectional view of a laminate film used to encapsulate components of a battery cell having a malleable layer surrounded by inner and outer polymer layers, with an outer insulating layer disposed between the malleable layer and the outer polymer layer. [Figure 8] FIG. 8 shows a schematic diagram of a battery module. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] 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.

[0029] 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.

[0030] One of the most common types of batteries in use today is the lithium-ion battery cell. A lithium-ion battery cell typically contains a cathode composed of carbon (e.g., graphite) and an anode composed of lithium. A non-aqueous electrolyte is used, usually containing a lithium salt. A polymer separator is used to separate the anode from the cathode.

[0031] FIG. 1 shows a schematic diagram of a typical pouch battery cell (e.g., a lithium pouch battery cell). A pouch battery cell is composed of one or more cathodes and one or more anodes. The one or more cathodes and anodes are typically in the form of sheets. The cathodes and anodes are separated from each other by a separator. An electrolyte composition is disposed between the cathode(s) and anode(s). The cathode(s), anode(s), electrolyte composition and separator, as well as other components such as current collectors and tabs, are collectively referred to herein as "battery cell components." In a pouch cell battery, the battery cell components are sealed in a flexible laminate film as shown in FIG. 1. It should be understood that FIG. 1 is intended for illustrative purposes only and that the number of cathodes and anodes may vary depending on the intended use of the battery cell and the type of chemistry being used to generate power.

[0032] Pouch battery cells offer many advantages over prismatic batteries, which use a hard aluminum or stainless steel case to seal the chemical components in. Some of the advantages of pouch battery cells are that they can be lighter in weight and that pouch battery cells can be easily made into a variety of sizes and shapes.

[0033] FIG. 2A shows a cross-sectional view of a typical laminate film 200 used to encapsulate the components of a battery cell (e.g., the pouch battery cell shown in FIG. 1). The laminate film includes an inner polymer layer 210, a metal foil layer 220 (typically aluminum), and an outer polymer layer 230. The inner polymer layer is typically formed from a polymer that is resistant to the chemical components of the pouch battery cell (e.g., the battery cell electrolyte). The metal foil layer is used to protect the battery cell from moisture and air. The metal foil layer can also be formed into compartments that hold the components of the battery cell. The outer polymer layer is used to protect the battery cell from external fluids, impacts, punctures, and scratches.

[0034] The present disclosure is directed to pouch battery cells that include an insulating layer in the sealing material that surrounds the components of the battery cell. The insulating layer incorporated in the sealing material of the pouch battery cell helps to prevent or inhibit the transfer of heat and heated particles to nearby battery cells during a thermal runaway event.

[0035] FIG. 3A shows a top view of the components of a battery cell sealed by a laminate film 300. The cross section A-A′ shown in FIG. 3A represents the location of the cross section used in the various examples of the sealed battery cell components shown in FIG. 3B, FIG. 4, FIG. 5, FIG. 6, and FIG. 7. Furthermore, for clarity, the cross sections shown in FIG. 3B, FIG. 4, FIG. 5, FIG. 6, and FIG. 7 show only a portion of the cross section. The portion shown includes only the components of the battery cell and one layer of the laminate film that seals the battery cell. For simplicity and convenience, this view is not specifically shown in the subsequent figures. FIG. 3B shows a cross section (A-A′) of an embodiment of a pouch battery cell laminate film 300. The pouch battery cell laminate film 300 is composed of an inner polymer layer 310 and an insulating layer 340 located on the inner polymer layer. The inner polymer layer is in contact with at least one of the components of the battery cell.

[0036] Adding an insulating layer to the battery cell sealing material can help mitigate problems associated with excessive heating and thermal runaway of the battery cells. 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., glass fiber-containing barriers). The insulating layer may be sealed to a single polymer film or a laminate of polymer films, as described in U.S. Provisional Patent Application No. 63 / 304,258, which is incorporated herein by reference.

[0037] 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.

[0038] The insulating layer can have a through-thickness thermal conductivity of about 50 mW / mK or less, about 40 mW / mK or less, about 30 mW / mK or less, about 25 mW / mK or less, about 20 mW / mK or less, about 18 mW / mK or less, about 16 mW / mK or less, about 14 mW / mK or less, about 12 mW / mK or less, about 10 mW / mK or less, about 5 mW / mK or less, or within a range of any two of these values, at 25° C. and under a load up to about 5 MPa.

[0039] In one aspect, the inner polymer layer comprises a material that can be heat welded to itself. Typically, after sealing the battery cell components, a portion of the inner polymer layer extends away from the battery cell components. The thermal seal may be formed by applying heat to the inner polymer layer. The applied heat increases the temperature of the polymer and may fuse the inner polymer layer to form a sealed pouch surrounding the battery cell components. An exemplary polymer that can be used as the inner polymer layer of the sealing material 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.

[0040] 4 shows a cross-sectional view (A-A') of an alternative embodiment of a pouch battery cell laminate film 400. The pouch battery cell laminate film 400 is composed of an inner polymer layer 410, an insulating layer 440, and an outer polymer layer 430. As shown in FIG. 4, the inner polymer layer 410 is in contact with the components of the battery cell. The insulating layer 440 is in contact with the inner polymer layer. The outer polymer layer 430 is in contact with the insulating layer. The insulating layer 440 is disposed between the inner polymer layer 410 and the outer polymer layer 430.

[0041] The outer polymer layer may also provide wear protection to the battery cell. During use, external stress may cause damage to the sealing material. If the sealing material is damaged, the battery cell may be compromised. External stresses that may occur in an unprotected battery cell include, but are not limited to, stresses caused by leakage of chemicals from a ruptured battery cell, expansion of the battery cell, 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 battery cell from external stresses. Exemplary polymers that may 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. Specific examples of polymers that may be used as the outer polymer layer include, but are not limited to, polyethylene terephthalate ("PET") and oriented nylon ("ONy").

[0042] Although a single outer polymer layer is described above, it should be understood that the outer polymer layer may be comprised of two or more polymer layers. When multiple outer polymer layers are used, the additional outer polymer layers may be formed from the same or different polymers. In one aspect of the invention, the outer polymer layer is comprised of an ONy polymer layer with an overlying PET polymer layer.

[0043] FIG. 5 shows a cross-sectional view (A-A') of an alternative embodiment of a pouch battery cell laminate film 500. The pouch battery cell laminate film 500 is composed of an inner polymer layer 510, an insulating layer 540, a malleable layer 520, and an outer polymer layer 530. As shown in FIG. 5, the inner polymer layer 510 is in contact with the components of the battery cell. The insulating layer 540 is in contact with the inner polymer layer. The malleable layer 520, which includes a malleable material, is in contact with the insulating layer. The outer polymer layer 530 is in contact with the malleable layer. The insulating layer 540 is disposed between the inner polymer layer 510 and the malleable layer 520. The malleable layer 520 is disposed between the insulating layer 540 and the outer polymer layer 530. The malleable layer may be disposed within the sealing layer to act as a support to facilitate handling of the pouch battery cell during manufacturing.

[0044] The malleable layer may also provide additional thermal and mechanical protection when used in the sealing material of the battery cells. During a thermal runaway event, the battery cells may heat up and release hot particles and gases from the battery cells. These releases may cause damage to the sealing material of adjacent pouch battery cells, potentially causing the neighboring battery cells to go into a runaway state. The malleable layer may inhibit or prevent the particulate matter and gases from damaging the battery cells. The malleable layer may also provide additional protection from moisture and air to the battery cells.

[0045] 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.

[0046] The use of metal foils can also add heat transfer properties to the encapsulation material surrounding the components of the battery cells. 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 foils can improve the thermal properties of the battery cells by providing a thermally conductive metal foil to the encapsulation material. Heat generated by an adjacent runaway battery cell or an affected battery cell can be transferred to the metal foil layer. The metal foil layer can be connected to a portion of the battery module case (e.g., a cooling plate) that allows the heat to be transferred through the metal foil in a direction away from the battery cells.

[0047] FIG. 6 shows a cross-sectional view (A-A') of an alternative embodiment of a pouch battery cell laminate film 600. The pouch battery cell laminate film 600 is composed of an inner polymer layer 610, a malleable layer 620, an insulating layer 640, and an outer polymer layer 630. As shown in FIG. 6, the inner polymer layer 610 is in contact with the components of the battery cell. The malleable layer 620, which includes a malleable material, is in contact with the inner polymer layer. The insulating layer 640 is in contact with the malleable layer. The outer polymer layer 630 is in contact with the insulating layer. The malleable layer 620 is disposed between the inner polymer layer 610 and the insulating layer 640. The insulating layer 640 is disposed between the malleable layer 620 and the outer polymer layer 630.

[0048] FIG. 7 shows a cross-sectional view (A-A') of an alternative embodiment of a pouch battery cell laminate film 700. The pouch battery cell laminate film 700 is composed of an inner polymer layer 710, a malleable layer 720, an outer polymer layer 730, and an insulating layer 740. As shown in FIG. 7, the inner polymer layer 710 is in contact with the components of the battery cell. The malleable layer 720, which includes a malleable material, is in contact with the inner polymer layer. The outer polymer layer 730 is in contact with the malleable layer. The insulating layer 740 is in contact with the outer polymer layer. The malleable layer 720 is disposed between the inner polymer layer 710 and the outer polymer layer 730. The outer polymer layer 730 is disposed between the malleable layer 720 and the insulating layer 740.

[0049] The laminate film used as the sealing material can be a single film composed of multiple layers as described herein. In one embodiment, the laminate film can be formed by placing a malleable layer and an insulating layer between two polymer layers (an inner polymer layer and an outer polymer layer) and melting the inner and outer polymer layers using heat and / or pressure. In another embodiment, an adhesive or tape can be used to hold the layers together. For example, an adhesive can be placed between adjacent layers to form a laminate film.

[0050] Insulation layers of the present disclosure, such as insulation layers comprising aerogel, may retain or slightly increase thermal conductivity (typically measured in mW / m·k) 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.

[0051] 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.

[0052] 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'".

[0053] 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).

[0054] 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.

[0055] 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.

[0056] 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.;

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] The insulating barrier according to various embodiments of the present disclosure thermally isolates a plurality of individual battery cells or battery cell modules from each other in a battery pack that includes the individual battery cells or battery cell modules. A battery module is comprised of a plurality of battery cells arranged in a single housing. A battery pack is comprised of a plurality of battery modules. FIG. 8 illustrates an embodiment of a battery module 800 having a plurality of battery cells 850. The sealed battery cells 850 include an insulating material incorporated into the sealing material. The insulating layer of the sealing material can limit or prevent damage to adjacent battery cells if the battery cells experience thermal runaway or any other catastrophic battery cell failure. By incorporating an insulating layer into the sealing material, it may be possible to assemble the battery module without the need for an insulating barrier between the battery cells. Alternatively, an insulating barrier that includes an insulating material in the sealing material can be placed between the battery cells.

[0063] 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.

[0064] 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.

[0065] 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.

Claims

1. A battery cell, A component of a battery cell, the component of the battery cell comprising: one or more cathodes; one or more anodes; components of the battery cell including one or more separators disposed between the one or more cathodes and the one or more anodes; the battery cell comprising: an encapsulation material surrounding components of the battery cell, the encapsulation material comprising an insulating layer.

2. 10. The battery cell of claim 1, wherein the encapsulation material comprises a laminate film including an inner polymer layer and an insulating layer disposed on the inner polymer layer, the inner polymer layer in contact with a component of the battery cell.

3. 2. The battery cell of claim 1, wherein the encapsulation material comprises a laminate film including an inner polymer layer, an insulating layer in contact with the inner polymer layer, and an outer polymer layer in contact with the insulating layer, the inner polymer layer in contact with a component of the battery cell, and the insulating layer disposed between the inner polymer layer and the outer polymer layer.

4. 2. The battery cell of claim 1, wherein the encapsulation material comprises a laminate film including an inner polymer layer, an insulating layer in contact with the inner polymer layer, a malleable layer including a malleable material in contact with the insulating layer, and an outer polymer layer in contact with the malleable layer, the inner polymer layer being in contact with a component of the battery cell, the insulating layer being disposed between the inner polymer layer and the malleable layer, and the malleable layer being disposed between the insulating layer and the outer polymer layer.

5. 2. The battery cell of claim 1, wherein the encapsulation material comprises a laminate film comprising an inner polymer layer, a malleable layer in contact with the inner polymer layer, the malleable layer comprising a malleable material, an insulating layer in contact with the malleable layer, and an outer polymer layer in contact with the insulating layer, the inner polymer layer in contact with a component of the battery cell, the malleable layer disposed between the inner polymer layer and the insulating layer, and the insulating layer disposed between the malleable layer and the outer polymer layer.

6. 2. The battery cell of claim 1, wherein the encapsulation material comprises a laminate film comprising an inner polymer layer, a malleable layer in contact with the inner polymer layer, the malleable layer comprising a malleable material, an outer polymer layer in contact with the malleable layer, and an insulating layer in contact with the outer polymer layer, the inner polymer layer in contact with a component of the battery cell, the malleable layer disposed between the inner polymer layer and the outer polymer layer, and the outer polymer layer disposed between the malleable layer and the insulating layer.

7. 10. The battery cell of any one of the preceding claims, wherein the battery cell is a lithium ion battery cell.

8. 10. The battery cell 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.

9. 2. The battery cell of any one of the preceding claims, wherein the inner polymer layer comprises a polyolefin polymer.

10. 2. The battery cell of any one of the preceding claims, wherein the inner polymer layer is made of a polymer different from the polymer of the outer polymer layer.

11. 10. The battery cell of any one of the preceding claims, wherein the outer polymer layer is made of polyethylene terephthalate ("PET") or oriented nylon ("ONy") and the inner polymer layer is made of polypropylene ("PP").

12. 13. The battery cell of any one of the preceding claims, wherein the outer polymer layer comprises a first polymer film made of a first material and a second polymer film made of a second material, the first material being different from the second material.

13. 2. The battery cell of any one of the preceding claims, wherein the malleable layer comprises a metal foil.

14. The battery cell of any one of claims 1 to 12, wherein the malleable layer comprises a malleable polymer.

15. 2. The battery cell of any one of the preceding claims, wherein the sealing layer further comprises an adhesive disposed between adjacent layers.

16. 2. The battery cell of any one of the preceding claims, wherein the outer polymer layer has a thickness of about 10 μm to about 100 μm.

17. 2. The battery cell of any one of the preceding claims, wherein the malleable layer has a thickness of about 10 μm to about 100 μm.

18. 2. The battery cell of any one of the preceding claims, wherein the inner polymer layer has a thickness of about 10 μm to about 100 μm.

19. 2. The battery cell of any one of the preceding claims, wherein the insulating layer has a thermal conductivity through its thickness of less than about 50 mW / m·K at 25°C and less than about 60 mW / m·K at 600°C.

20. 2. The battery cell of any one of the preceding claims, wherein the insulating layer comprises an aerogel.

21. 2. The battery cell of claim 1, wherein the sealing layer comprises two laminate films heat-sealed together.

22. A battery module comprising a plurality of battery cells according to any one of claims 1 to 21.

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

24. A device or vehicle comprising the battery module of claim 22 or 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.

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