Degassing and filtering components for encapsulated thermal barriers

Abstract

The present disclosure relates to materials and systems for managing the problem of thermal runaway in energy storage systems. Exemplary embodiments include an insulating layer encapsulated to form an insulating barrier. The insulating barrier includes a particle-trapping layer. The particle-trapping layer traps particles that are released from the insulating barrier during compression of the insulating barrier.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 218,205, filed on July 2, 2021, and entitled "Materials, Systems, and Methods for Mitigation of Electrical Energy Storage Thermal Events," and U.S. Provisional Patent Application No. 63 / 311,299, filed on February 17, 2022, and entitled "Venting and Filtering Components for a Battery Barrier," each of which is incorporated by reference in its entirety into this specification.

[0002] The present disclosure relates generally to materials, systems, and methods for venting and filtering of battery modules or battery packs. In particular, the present disclosure relates to materials, systems, and methods that provide filtered venting that allows gas to escape an insulating barrier while capturing particulate matter in the emitted gas. [Background technology]

[0003] Rechargeable batteries, such as lithium-ion batteries, have found wide applications in motor-driven energy storage systems. Lithium-ion batteries (LIBs) are widely used in powering portable electronic devices, such as cell 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 exist because LIBs are susceptible to catastrophic failure under "severe 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 exposed to conditions outside their design range.

[0004] Thermal runaway can occur when the internal reaction rate increases to the point where more heat is generated than can be extracted, resulting in a further increase in both reaction rate and heat generation. During thermal runaway, high temperatures trigger a chain of exothermic reactions in the battery, causing the temperature of the battery to rise rapidly. In many cases, when thermal runaway occurs in one battery cell, the generated heat causes cells in close proximity to the cell experiencing thermal runaway to heat up faster. Each cell that adds to the thermal runaway reaction traps additional energy to continue the reaction, causing thermal runaway propagation within the battery pack, and ultimately resulting in a catastrophic accident resulting in fire or explosion. Rapid heat dissipation and effective blocking of 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 battery thermal runaway, many approaches have been explored with the goal of reducing safety hazards through rational design of battery components. To prevent such cascading thermal runaway events from occurring, LIBs are typically designed to either keep the stored energy low enough, or to utilize thermal barriers between cells inside a battery module or pack, or to insulate cells from thermal events that may occur in adjacent cells, or a combination of both. The former severely limits the amount of energy that can potentially be stored in such devices. The latter limits the available energy density by restricting the manner in which closed cells can be arranged.

[0006] Aerogel materials have been used as thermal barrier materials. Aerogel thermal barriers offer many advantages over other thermal barrier materials. Some of these benefits include favorable resistance to heat and fire propagation while minimizing the thickness and weight of the materials used. Aerogel thermal barriers also have favorable properties related to compressibility, compressive resiliency, and compliance. The light weight and low stiffness of some aerogel-based thermal barriers can make them difficult to install between battery cells, especially in mass production situations. Additionally, aerogel thermal barriers tend to generate particulate matter (dust) that can be harmful to electrical storage systems, creating manufacturing challenges.

[0007] To alleviate problems associated with handling the aerogel material, the aerogel thermal barrier is sometimes encapsulated. The encapsulation material used to encapsulate the aerogel thermal barrier generally creates an airtight seal around the thermal barrier and prevents particulate matter from escaping from the insulating barrier. Summary of the Invention

[0008] It is an object of the present disclosure to obviate or mitigate at least one of the disadvantages of the aforementioned methods and materials described above. The insulating barrier provided herein is designed to improve the encapsulation and handling of thermal barriers used in battery modules or battery packs.

[0009] In an aspect of the disclosure, an insulating barrier for use in an electrical energy storage system includes at least one insulating layer, an encapsulation layer at least partially surrounding the insulating layer, the encapsulation layer including one or more openings, and a particle-trapping layer coupled to the encapsulation layer. Particles and gases generated during compression of the insulating barrier flow toward the one or more openings in the encapsulation layer. The particles and gases flow through the particle-trapping layer where at least a portion of the particles are retained within the particle-trapping layer.

[0010] In an embodiment of the present disclosure, the particle-trap layer is disposed on the exterior surface of the encapsulation layer across the one or more openings such that particles generated during compression of the insulating barrier pass through the one or more openings in the encapsulation layer and are at least partially retained within the particle-trap layer.

[0011] In an aspect of the disclosure, the encapsulation layer has an elongated opening. The encapsulation layer partially covers the insulating layer such that the elongated opening in the encapsulation layer is disposed along a side of the insulating layer. The particle-trap layer is bonded to the encapsulation layer such that the particle-trap layer is disposed over the elongated opening in the encapsulation layer.

[0012] In an aspect of the present disclosure, the encapsulation layer has a plurality of openings disposed along one or more sides of the insulating layer, and a particle-trap layer is coupled to the encapsulation layer such that the particle-trap layer is disposed over the plurality of openings in the encapsulation layer.

[0013] In some aspects of the present disclosure, the particle capture layer is bonded to the encapsulation layer by an adhesive material that is positioned proximate to an opening in the encapsulation layer to act as a barrier to the flow of particles and gases toward the particle capture layer.

[0014] In an aspect of the disclosure, the particle-trap layer is disposed inside the encapsulation layer such that, during use, particles and gases generated during compression of the insulating barrier enter the particle-trap layer before passing through one or more openings in the encapsulation layer and are at least partially retained within the particle-trap layer.

[0015] The particle-trapping layer can be a foam material, a woven material, a nonwoven material, or a mesh material.

[0016] In an embodiment of the present disclosure, the insulating barrier includes one or more polymer films bonded to a particle-trapping layer. The polymer films inhibit and / or trap particles during compression of the insulating barrier. One or more of the polymer films may take the form of a filter that inhibits the flow of particles through the polymer film and allows the passage of gas through the polymer film. In an embodiment of the present disclosure, one of the polymer films covers a portion of the particle-trapping layer opposite the insulating layer. In another embodiment of the present disclosure, one of the polymer films covers a portion of the insulating layer and the particle-trapping layer.

[0017] In an embodiment of the present disclosure, the insulating layer has a thermal conductivity through the thickness dimension of the insulating layer of less than about 50 mW / m·K at 25° C. and less than about 60 mW / m·K at 600° C. In an embodiment of the present disclosure, the insulating layer comprises an aerogel.

[0018] In an aspect of the present disclosure, the insulating layer comprises an aerogel material.

[0019] In aspects of the present disclosure, the encapsulation layer comprises a polymeric material. In some aspects of the present disclosure, the encapsulation layer comprises a polymeric material and a metal layer embedded in the polymeric material.

[0020] In another aspect of the disclosure, a battery module includes a plurality of battery cells and one or more insulating barriers disposed between adjacent battery cells as described herein.

[0021] In another aspect, the device or vehicle provided herein comprises the battery module or battery 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, a secret information gathering sensor, an electronic integrated garment, a night vision device, a power tool, a calculator, a radio, a remote control device, a GPS device, a handheld and portable television, a car starter, a flashlight, an acoustic device, a portable heating device, a portable vacuum cleaner, or a portable medical tool.In some embodiments, the vehicle is an electric car.

[0022] The insulating barriers described herein may provide one or more advantages over existing thermal runaway mitigation solutions. The insulating barriers described herein may minimize or eliminate thermal runaway propagation in cells without significantly impacting the energy density and assembly cost of the battery module or battery pack. The insulating barriers of the present disclosure may provide favorable properties in terms of compressibility, compressive resilience, and compliance to accommodate continued cell expansion over the life of the cell, while retaining favorable thermal properties under normal operating conditions and under thermal runaway conditions. The insulating barriers described herein are durable, easy to handle, favorable resistance to heat and fire propagation while minimizing the thickness and weight of the materials used, and also have favorable properties in terms of compressibility, compressive resilience, and compliance.

[0023] The disclosure is therefore described in general terms and reference is now made to the accompanying drawings, which are not necessarily drawn to scale. [Brief description of the drawings]

[0024] [Figure 1] 1A and 1B are projections of an insulating barrier having a particle-trapping layer bonded to the side of the insulating layer. [Diagram 2] 1A and 1B are projections of an insulating barrier having a particle-trapping layer bonded to a side of an insulating layer that is partially covered by an encapsulation layer. [Diagram 3] FIG. 2 is a projection view of an insulating barrier having a particle-trap layer bonded to a side of an insulating layer, the particle-trap layer being encapsulated by the insulating layer. [Figure 4] 1 shows end and side views of an insulating barrier having an encapsulated insulating layer with a particle-trapping layer bonded to a sidewall of the insulating layer. [Diagram 5] FIG. 2 shows a projection view of an insulating barrier with a polymeric film filter layer. [Figure 6] FIG. 1 shows a schematic diagram of an insulating barrier having a particle-trapping layer encapsulated with an insulating layer and one or more openings in the encapsulation layer that allow gas to escape through the insulating barrier. [Figure 7] FIG. 2 shows a schematic diagram of an insulating barrier having an encapsulated insulating layer in which a particle-trapping layer is bonded to the encapsulation layer via an adhesive. [Figure 8] FIG. 13 shows an alternative schematic diagram of an insulating barrier having an encapsulated insulating layer in which a particle-trapping layer is bonded to the encapsulation layer via an adhesive. [Figure 9] FIG. 1 shows a schematic diagram of a battery module having an insulating barrier between battery cells. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] 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 thereto are not intended to limit the invention to the particular forms disclosed, 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.

[0026] In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown, by way of illustration, specific embodiments in which the present 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.

[0027] The present disclosure is directed to insulating barriers and systems including insulating barriers to manage thermal runaway issues in energy storage systems. Exemplary embodiments include an insulating barrier including at least one insulating layer and an encapsulation layer at least partially surrounding the insulating layer.

[0028] The insulating layer may include any type of insulating layer typically 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, expandable materials, aerogel materials, mineral-based barriers (e.g., mica), and inorganic thermal barriers (e.g., fiberglass containing barriers).

[0029] In a preferred embodiment, the insulating layer comprises an aerogel material. A description of aerogel insulating layers is set forth 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.

[0030] The insulating layer can have a thermal conductivity of about 50 mW / mK or less, about 40 mW / mK or less, about 30 mW / mK or less, about 25 mW / mK or less, about 20 mW / mK or less, about 18 mW / mK or less, about 16 mW / mK or less, about 14 mW / mK or less, about 12 mW / mK or less, about 10 mW / mK or less, about 5 mW / mK or less, or a range between any two of these values, at 25° C. when subjected to a load of up to about 5 MPa through the thickness dimension of the insulating layer.

[0031] Insulation layers can have several 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 it difficult to handle and position the material between battery cells. In addition, materials with low flexural modulus can be difficult to manipulate, especially when using automated encapsulation processes. Some insulation layers tend to generate particulate matter (dust) that can be harmful to electrical storage systems, creating manufacturing challenges.

[0032] These problems can be alleviated by using an encapsulation layer. The encapsulation layer surrounds at least a portion of the insulating layer to inhibit or prevent particulate matter from being released into the battery module or battery pack. The encapsulation layer is generally sealed around the insulating layer so that particles and gas cannot enter or leave the encapsulation layer. During compression of the encapsulation layer, the encapsulation layer may rupture or leak released particles and gas into the battery module. To alleviate this problem, improvements can be made to the encapsulation layer. The first improvement is that the encapsulation layer is provided with one or more openings. These openings provide a flow path that allows the gas and particles to exit the encapsulation layer. The second improvement is to bond a particle-trapping layer to the encapsulation layer. The particles and gas generated during compression of the insulating barrier are allowed to flow toward the one or more openings in the encapsulation layer, and the particulate matter flowing with the gas is at least partially retained within the particle-trapping layer.

[0033] The encapsulation layer is a single layer or multi-layer material. The encapsulation layer may be in the form of a thin film, an envelope, or a bag. The encapsulation layer may be made of any material suitable for enclosing the insulating layer. The material used to form the encapsulation layer may be selected from polymers, elastomers, or combinations thereof. Examples of suitable polymers such as polyethylene terephthalate (PET), polyethylene (PE), polyimide (PI), polypropylene, polyamide, rubber, and nylon have very low thermal conductivity (less than 1 W / m) which has the effect of reducing the thermal conductivity of the planar surface throughout the system. In one embodiment, the encapsulation layer comprises a polyethylene terephthalate polymer.

[0034] In another embodiment, the encapsulation layer is made of a multi-layer material. For example, a multi-layer material similar to that used to form the pouch battery cell case may be used. In one embodiment, the encapsulation layer includes a laminate including three layers, namely a first polymer layer, a second thermally conductive layer, and a third polymer layer, with the thermally conductive layer sandwiched between the first and third polymer layers. The first and third polymer layers are preferably formed from polymers having very low thermal conductivity (less than 1 W / m). Examples of polymers that can be used for the first and third polymer layers include, but are not limited to, polyethylene terephthalate (PET), polyethylene (PE), polypropylene, polyamide, and nylon. Examples of thermally conductive materials that can be used for the second layer include, but are not limited to, metals (e.g., copper, stainless steel, or aluminum), carbon fiber, graphite, and silicon carbide. When using a metal thermally conductive layer, the metal can be in the form of a foil sandwiched between the polymer layers.

[0035] In another embodiment, the encapsulation layer comprises a laminate including three layers, namely a first polymer layer, a second flame retardant layer, and a third polymer layer, with the flame retardant layer sandwiched between the first and third polymer layers. As previously explained, the first and third polymer layers are preferably formed from polymers with very low thermal conductivity (less than 1 W / m). Examples of flame retardant materials that can be used in the second layer include, but are not limited to, metals (e.g., copper, stainless steel, or aluminum), mica, polybenzimidazole fibers (PBI fibers), coated nylon, melamine, modacrylic, and aromatic polyamides (aramids). When using a metal thermally conductive layer, the metal can be in the form of a foil sandwiched between the polymer layers.

[0036] Metal is a preferred material for use in the laminate encapsulation layer. Metal provides both thermally conductive properties and flame retardant properties to the encapsulation layer. By using a single material to provide both flame retardant and thermally conductive properties, the thickness of the encapsulation layer can be minimized.

[0037] An embodiment of an insulating barrier including a particle-trap layer is shown in Figures 1A and 1B. The insulating barrier 100 includes an insulating layer 110. The insulating layer 110 is surrounded by an encapsulation layer 120. As shown in Figure 1B, one or more openings 130 may be formed in the encapsulation layer 120. A particle-trap layer 140 is coupled to the encapsulation layer 120. In this embodiment, the particle-trap layer 140 is disposed on the outer surface of the encapsulation layer 120 across the one or more openings. During compression of the insulating barrier, particles and gas flow toward one or more of the openings in the encapsulation layer. As the particles and gas pass through the openings, the gas and particles enter the particle-trap layer where at least a portion of the particles are retained within the particle-trap layer. In this and any other embodiment, the particle-trap layer is shown as being disposed at an end of the insulating layer, but it should be understood that the particle-trap layer and the openings in the encapsulation layer may be disposed along any side of the insulating layer (i.e., top, bottom, front wall, rear wall, front end, and rear end).

[0038] As used herein, a particle trapping layer refers to a layer of material that can trap particles that impact the material. Examples of materials used for particle trapping layers include, but are not limited to, foam (open or closed cell), woven materials, nonwoven materials (e.g., felt, batting, matted cloth), or netting materials. Generally, particle trapping layers are made of materials that allow gas to pass through the material while particles are retained in the particle trapping layer.

[0039] An embodiment of an insulating barrier including a particle-trap layer is shown in Figures 2A and 2B. The insulating barrier 200 includes an insulating layer 210. The insulating layer 210 is surrounded by an encapsulation layer 220. As shown in Figure 2B, the encapsulation layer is not completely sealed along one side of the insulating layer. In this way, a single elongated opening 230 along the entire side of the insulating layer is formed. A particle-trap layer 240 is bonded over the elongated opening 230. In this embodiment, the particle-trap layer 240 is disposed on the outer surface of the insulating layer 210. During compression of the insulating barrier, particles and gas flow toward the elongated opening in the encapsulation layer. As the particles and gas pass through the opening, the gas and particles enter the particle-trap layer, where at least a portion of the particles are retained within the particle-trap layer.

[0040] Another embodiment of an insulating barrier including a particle-trap layer is shown in FIG. 3. The insulating barrier 300 includes an insulating layer 310. The insulating layer 310 is surrounded by an encapsulation layer 320. One or more openings 330 may be formed in the encapsulation layer 320. A particle-trap layer 340 is coupled to the encapsulation layer 320. In this embodiment, the particle-trap layer 340 is disposed between the insulating layer 310 and the encapsulation layer 320 in fluid contact with the one or more openings. During compression of the insulating barrier, the particles and gas flow toward one or more of the openings in the encapsulation layer. As the particles and gas travel toward the openings, the gas and particles enter the particle-trap layer where at least a portion of the particles are retained within the particle-trap layer. The gas continues through the particle-trap layer 340 and exits through the openings 330. As the gas passes through the material, the particles are substantially retained in the particle-trap layer.

[0041] Another embodiment of an insulating barrier including a particle-trap layer is shown in FIG. 4. The insulating barrier 400 includes an insulating layer 410. The insulating layer 410 is surrounded by an encapsulation layer 420. One or more openings 430 may be formed in the sidewall of the encapsulation layer 420. A particle-trap layer 440 is attached to the encapsulation layer 420 using an adhesive 450 (e.g., an adhesive strip). In this embodiment, the particle-trap layer 440 is disposed over the openings formed in the encapsulation layer. During compression of the insulating barrier, the particles and gas flow toward one or more of the openings in the encapsulation layer. As the particles and gas pass through the openings 430, the gas and particles enter the particle-trap layer 440, where at least a portion of the particles are retained within the particle-trap layer. As the gas passes through the material, the particles are substantially retained in the particle-trap layer.

[0042] Another embodiment of an insulating barrier including a particle-trap layer is shown in Figures 5A and 5B. The insulating barrier 500 includes an insulating layer 510. A particle-trap layer 540 is bonded to the insulating layer 510. In some embodiments, a first polymer film 515 is disposed between the insulating layer and the particle-trap layer. The insulating layer 510, the first polymer film 515, and the particle-trap layer 540 are surrounded by an encapsulation layer 520. One or more openings 530 may be formed in the encapsulation layer 520. A second polymer film 550 is bonded to the particle-trap layer 540 and disposed between the insulating layer 510, the particle-trap layer 540, and the openings 530. The first and second polymer films may be in the form of a filter that allows gas to pass through the film but prevents the progression of particles through the film. Examples of polymeric materials that can be used include polyethylene terephthalate (PET) and polypropylene (PP). The first and second polymer films are thin films (e.g., polymer films having a thickness of less than 1 mm). During compression of the insulating barrier, particles and gas flow toward one or more of the openings in the encapsulation layer. The first and second polymer films act as filters that capture at least a portion of the particles as they are forced toward the openings. The gas continues through the particle-trapping layer 540 and exits through the openings 530. As the gas passes through the material, the particles are substantially retained in the particle-trapping layer.

[0043] Another embodiment of an insulating barrier including a particle-trap layer is shown in FIG. 6. The insulating barrier 600 includes an insulating layer 610. A particle-trap layer 640 is bonded to the insulating layer 610. A polymer film 650 is bonded to the particle-trap layer 640. The insulating layer 610, the polymer film 650, and the particle-trap layer 640 are surrounded by an encapsulation layer 620. The encapsulation layer 620 has one or more openings 630 formed therein. The polymer film 650 is disposed between the particle-trap layer 640 and the one or more openings 630. The polymer film 650 may be impermeable to the passage of gas and particles. During compression of the insulating barrier, particles and gas flow toward one or more of the openings in the encapsulation layer. Due to the barrier properties of the polymer film 650, gas and particles that enter the particle-trap layer are directed further away from the openings through the particle-trap layer before the gas is exhausted from the openings 630. By extending the flow path through the particle-trapping material, particle trapping efficiency is increased.

[0044] Another embodiment of an insulating barrier including a particle-trap layer is shown in FIG. 7. The insulating barrier 700 includes an insulating layer 710. The insulating layer 710 is surrounded by an encapsulation layer 720. A particle-trap layer 740 is bonded to the insulating layer 710 by attaching the particle-trap layer to the encapsulation layer using an adhesive 760 (e.g., an adhesive strip or adhesive pad). A polymer film 750 is bonded to the particle-trap layer 740. The encapsulation layer 720 has one or more openings 730 formed therein. The polymer film 750 is disposed on the opposite side of the particle-trap layer 740 from the insulating layer 710. The polymer film 750 may be impermeable to the passage of gas and particles. As shown in FIG. 7, during compression of the insulating barrier, particles and gas flow toward and through one or more of the openings in the encapsulation layer. The barrier properties of the polymer film 750 allow the gas and particles to pass through the particle-trap layer before the gas is exhausted from the particle-trap layer. The adhesive 760 creates an additional barrier to particle and gas flow. The adhesive 760 directs particles and gases escaping from the encapsulation layer to the particle-trapping layer. By providing a directional flow path through the particle-trapping material, particle trapping efficiency is improved.

[0045] Another embodiment of an insulating barrier including a particle-trap layer is shown in FIG. 8. The insulating barrier 800 includes an insulating layer 810. The insulating layer 810 is surrounded by an encapsulation layer 820. A particle-trap layer 840 is bonded to the insulating layer 810 by attaching the particle-trap layer to the encapsulation layer using an adhesive 860 (e.g., an adhesive strip or adhesive pad). A polymer film 850 is bonded to the particle-trap layer 840. The encapsulation layer 820 is formed with one or more openings 830. The polymer film 850 is disposed on the opposite side of the particle-trap layer 840 from the insulating layer 810. The polymer film 850 may be impermeable to the passage of gas and particles. As shown in FIG. 8, during compression of the insulating barrier, particles and gas flow toward and through one or more of the openings in the encapsulation layer. The barrier properties of the polymer film 850 allow the gas and particles to pass through the particle-trap layer before the gas is exhausted from the particle-trap layer. The adhesive 860 creates an additional barrier to particle and gas flow. The adhesive 860 further directs particles and gases into the particle-trapping layer, providing a longer flow path for particle capture. By providing a directional flow path through the particle-trapping material, particle capture efficiency is improved.

[0046] 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 utilized in its sense including "and / or" unless the context clearly dictates otherwise.

[0047] Within the context of this disclosure, the terms "aerogel," "aerogel material," or "aerogel matrix" refer to a gel that includes an interconnected framework with a corresponding network of interconnected pores integrated within the framework, that confines a gas, such as air, as a dispersed interstitial medium, and that is characterized by the following physical and structural properties (as determined by nitrogen porosimetry testing) that are attributable to aerogels: (a) an average pore size ranging from 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 / g or more surface area.

[0048] Thus, the aerogel materials of the present disclosure include any aerogel or other open-cell type material that satisfies the defining elements set forth in the preceding paragraph, including materials that can otherwise be classified as xerogels, cryogels, ambigels, microporous materials, etc.

[0049] Within the context of this disclosure, reference to "thermal runaway" generally refers to a sudden, rapid increase in cell temperature and pressure due to various operating factors, and thermal runaway may even result in the propagation of excessive temperatures throughout the associated module. Potential causes of thermal runaway in such systems may include, for example, cell defects and / or shorts (both internal and external), cell insulation breakdown or rupture such as overcharging, accidental events, and the like, and excessive ambient temperatures (e.g., temperatures typically greater than 55°C). In normal use, cells heat up as a result of internal resistance. Under normal power / current loads and ambient operating conditions, the temperature within most Li-ion cells can be relatively easily controlled to remain in the range of 20°C to 55°C. However, under stressful conditions such as high power draw at high cell / ambient temperatures, as well as individual cell defects, localized heating may increase suddenly. In particular, above a critical temperature, exothermic chemical reactions within the cells become active. Furthermore, chemical heat generation generally results in a rapid increase in temperature. As a result, the heat generation is much greater than the available heat dissipation. Thermal runaway can cause the temperature at the cell's vent and inside to exceed 200°C.

[0050] 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 where there is a temperature difference between the two surfaces. Thermal conductivity is specifically measured as the heat energy transferred per unit time and per unit surface area divided by the temperature difference. It is usually recorded in SI units as mW / m*K (milliwatts per meter*Kelvin). The thermal conductivity of a material may be determined by the following test methods known in the art: Test methods include, but are not limited to, Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus (ASTM C518, ASTM International, West Conshohocken, PA), Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus (ASTM C177, ASTM International, West Conshohocken,PA), Test Method for Steady-State Heat Transfer Properties of Pipe Insulation(ASTM C335,ASTM International,West Conshohocken,PA), Thin Heater Thermal Conductivity Test(ASTM C1114,ASTM International,West Conshohocken,PA), Standard Test Method for Thermal Transmission Properties of Thermally Conductive Electrical Insulation Materials(ASTM D5470,ASTM International,West Conshohocken,PA), Determination of thermal resistance by means of guarded hot plate and heat flow meter methods (EN 12667, British Standards Institution, United Kingdom), or Determination of steady-state thermal resistance and related properties-Guarded hot plate apparatus (ISO 8203, International Organization for Standardization, Switzerland). It is understood that, with different methods sometimes leading to different results, 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 ambient atmospheric pressure and under a compressive load of about 2 psi. Measurements reported as per ASTM C518 generally correlate well with any of the measurements made as per EN 12667 with any relevant adjustment for compressive load.

[0051] Thermal conductivity measurements are also obtained at a temperature of about 10° C. at atmospheric pressure during compression. Thermal conductivity measurements at 10° C. are generally 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 a range between any two of these values.

[0052] Use of isolation barriers inside battery modules or battery 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 significant barrier preventing the large-scale use of LIBs. Under extreme conditions, exothermic reactions can result in heat release that can trigger subsequent dangerous reactions. The situation worsens when heat release from cells under extreme conditions can activate chain reactions, resulting in sudden thermal runaway.

[0053] With the continuous improvement of the energy density of LIBs, it becomes increasingly urgent to enhance their safety for the development of electric devices, e.g., electric vehicles. The mechanisms behind the safety issues vary for different battery chemistries. The present technology focuses on tailoring the insulating barrier and the corresponding configuration of the tailored barrier to obtain favorable thermal and mechanical properties. The present technology's insulating barrier ensures the stability of the LIB under normal operation modes (e.g., withstanding applied compressive stress) while providing an effective heat dissipation solution under normal conditions as well as under thermal runaway conditions.

[0054] The insulation barriers disclosed herein are useful for isolating, insulating, and protecting battery cells or battery components of any configuration of battery, such as pouch cells, cylindrical cells, prismatic cells, as well as packs and modules incorporating or including any such cells. The insulation barriers disclosed herein are useful in rechargeable batteries, such as lithium ion batteries, solid state batteries, and any other energy storage device or technology requiring isolation, insulation, and protection.

[0055] Passive devices such as cooling systems may be used in conjunction with the insulating barriers of the present disclosure inside a battery module or battery pack.

[0056] An isolation barrier according to various embodiments of the present disclosure of a battery pack includes a plurality of single battery cells or modules of battery cells to thermally isolate the single battery cells or modules of battery cells from one another. A battery module is comprised of multiple battery cells arranged in a single housing. A battery pack is comprised of multiple battery modules. FIG. 9 shows an embodiment of a battery module 900 having multiple battery cells 950. An encapsulated isolation barrier 925 is disposed between the battery cells 950. The encapsulated isolation barrier can inhibit or prevent damage to adjacent battery cells when the battery cells experience thermal runaway or some other catastrophic battery cell failure.

[0057] 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 devices, video devices, display panels, video cameras, digital cameras, desktop computers, military portable computers, military phones, laser range finders, digital communication devices, intelligence gathering sensors, electronic integrated clothing, night vision equipment, power tools, calculators, radios, remote control devices, GPS devices, handheld and portable televisions, car starters, flashlights, sound devices, portable heating devices, portable vacuum cleaners, or portable medical tools. When used in vehicles, the battery packs can be used for all-electric vehicles or in hybrid vehicles.

[0058] In this patent, certain U.S. patents, U.S. patent applications, and other materials (e.g., articles) are incorporated by reference. However, the text of such U.S. patents, U.S. patent applications, and other materials is incorporated by reference only to the extent that there is no conflict between such text and the other claims and drawings described herein. In the event of such a conflict, any such conflicting text so incorporated by the referenced U.S. patents, U.S. patent applications, and other materials is specifically not incorporated by reference in this patent.

[0059] Further refinements 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 for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It should be understood that the forms of the invention shown and described herein are to be considered as examples of multiple embodiments. Elements and materials may be substituted for those shown and described herein, and components and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to those 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. Some of the embodiments of the invention related to the present invention are given below. [Embodiment 1] 1. An isolation barrier for use in an electrical energy storage system, comprising: at least one insulating layer; an encapsulation layer at least partially surrounding the insulating layer, the encapsulation layer including one or more openings; and a particle-trap layer coupled to the encapsulation layer; The insulating barrier, wherein particles and gases generated during compression of the insulating barrier flow toward the one or more openings in the encapsulation layer, and the particles are at least partially retained within the particle-trapping layer. [Embodiment 2] 2. An insulating barrier as described in embodiment 1, wherein the particle-trap layer is disposed on an exterior surface of the encapsulation layer across the one or more openings, such that particles generated during compression of the insulating barrier pass through the one or more openings of the encapsulation layer and are at least partially retained within the particle-trap layer. [Embodiment 3] 3. The insulating barrier of embodiment 2, wherein the encapsulation layer includes an elongated opening, the encapsulation layer partially covers the insulating layer such that the elongated opening in the encapsulation layer is disposed along a side of the insulating layer, and the particle capture layer is bonded to the encapsulation layer such that the particle capture layer is disposed over the elongated opening in the encapsulation layer. [Embodiment 4] 3. The insulating barrier of embodiment 2, wherein the encapsulation layer includes a plurality of openings disposed along one or more sides of the insulating layer, and the particle capture layer is bonded to the encapsulation layer such that the particle capture layer is disposed over the plurality of openings in the encapsulation layer. [Embodiment 5] 5. The insulating barrier of embodiment 3 or embodiment 4, wherein the particle-trapping layer is bonded to the encapsulation layer by an adhesive material. [Embodiment 6] 6. The insulating barrier of embodiment 5, wherein the adhesive material is disposed proximate to the opening such that the adhesive material acts as a barrier to the flow of the particles and gases directing the particles and gases toward the particle-trap layer. [Embodiment 7] 2. An insulating barrier as described in embodiment 1, wherein the particle-trap layer is disposed inside the encapsulation layer, and wherein, during use, particles and gases generated during compression of the insulating barrier enter the particle-trap layer before passing through the one or more openings in the encapsulation layer and are at least partially retained within the particle-trap layer. [Embodiment 8] 8. The insulating barrier of any one of the preceding embodiments, wherein the particle-trap layer comprises a foam material. [Embodiment 9] 8. The insulating barrier of any one of the preceding claims, wherein the particle-trapping layer comprises a woven material, a nonwoven material, or a mesh material. [Embodiment 10] 10. The insulating barrier of any one of claims 1 to 9, further comprising one or more polymer films coupled to the particle-trapping layer, the polymer films inhibiting and / or trapping particles during compression of the insulating barrier. [Embodiment 11] 11. The insulating barrier of embodiment 10, wherein one or more of the polymer films are in the form of a filter that inhibits the flow of the particles through the polymer film and allows the passage of the gas through the polymer film. [Embodiment 12] 11. The insulating barrier of embodiment 10, wherein one of the polymer films covers a portion of the particle-trapping layer opposite the insulating layer. [Embodiment 13] 11. The insulating barrier of embodiment 10, wherein one of the polymer films covers the insulating layer and a portion of the particle-trapping layer. [Embodiment 14] 13. The insulating barrier of any one of the preceding claims, wherein the insulating layer has a thermal conductivity through a thickness dimension of the insulating layer of less than about 50 mW / m·K at 25°C and less than about 60 mW / m·K at 600°C. [Embodiment 15] 14. The insulating barrier of any one of the preceding embodiments, wherein the insulating layer comprises an aerogel. [Embodiment 16] 15. The insulating barrier of any one of the preceding embodiments, wherein the encapsulation layer comprises a polymeric material. [Embodiment 17] 15. The insulating barrier of any one of the preceding embodiments, wherein the encapsulation layer comprises a polymeric material and a metal layer embedded in the polymeric material. [Embodiment 18] A battery module, A plurality of battery cells; The battery module comprising one or more insulating barriers according to any one of embodiments 1 to 17, wherein at least one insulating barrier is disposed between adjacent battery cells. [Embodiment 19] 20. A power system comprising one or more battery modules as described in embodiment 18. [Embodiment 20] A device or vehicle comprising a battery module according to embodiment 18. [Embodiment 21] The device of embodiment 20, 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 range finder, a digital communication device, a secret intelligence gathering sensor, an electronic integrated garment, a night vision device, a power tool, a calculator, a radio, a remote control device, a GPS device, a handheld and portable television, a car starter, a flashlight, an acoustic device, a portable heating device, a portable vacuum cleaner, or a portable medical tool. [Embodiment 22] 21. The vehicle of embodiment 20, wherein the vehicle is an electric vehicle.

Claims

1. 1. An isolation barrier for use in an electrical energy storage system, comprising: At least one insulating layer; an encapsulation layer at least partially surrounding the insulating layer, the encapsulation layer including one or more openings; and a particle-trapping layer coupled to the encapsulation layer and disposed between the at least one insulating layer and the encapsulation layer; The insulating barrier, wherein particles and gases generated during compression of the insulating barrier flow toward the one or more openings in the encapsulation layer, and the particles are at least partially retained within the particle-trapping layer.

2. An insulating barrier for use in an electric energy storage system, comprising: At least one insulating layer; an encapsulation layer at least partially surrounding the insulating layer, the encapsulation layer including one or more openings; and a particle-trap layer coupled to the encapsulation layer; particles and gases generated during compression of the insulating barrier flow toward the one or more openings in the encapsulation layer, and the particles are at least partially retained within the particle-trapping layer; an insulating barrier, wherein the particle capture layer is disposed on an outer surface of the encapsulation layer across the one or more openings, and particles generated during compression of the insulating barrier pass through the one or more openings in the encapsulation layer and are at least partially retained within the particle capture layer.

3. 3. The insulation barrier of claim 2, wherein the encapsulation layer includes an elongated opening, the encapsulation layer partially covers the insulation layer such that the elongated opening in the encapsulation layer is disposed along a side of the insulation layer, and the particle-trap layer is bonded to the encapsulation layer such that the particle-trap layer is disposed over the elongated opening in the encapsulation layer.

4. 3. The insulation barrier of claim 2, wherein the encapsulation layer includes a plurality of openings disposed along one or more sides of the insulation layer, and the particle-trap layer is coupled to the encapsulation layer such that the particle-trap layer is disposed over the plurality of openings in the encapsulation layer.

5. The insulating barrier of claim 3 , wherein the particle-trap layer is bonded to the encapsulation layer by an adhesive material.

6. 6. The insulating barrier of claim 5, wherein the adhesive material is disposed proximate the opening such that the adhesive material acts as a barrier to the flow of the particles and gases directing the particles and gases toward the particle-trap layer.

7. 2. The insulating barrier of claim 1 , wherein during use, particles and gases generated during compression of the insulating barrier enter the particle-trap layer before passing through the one or more openings in the encapsulation layer and are at least partially retained within the particle-trap layer.

8. The insulating barrier of claim 1 , wherein the particle-trapping layer comprises a foam material.

9. The insulating barrier of claim 1 , wherein the particle-trapping layer comprises a woven material, a nonwoven material, or a mesh material.

10. 10. The insulating barrier of claim 1, further comprising one or more polymer films coupled to the particle-trapping layer, the polymer films inhibiting and / or trapping particles during compression of the insulating barrier.

11. 11. The insulating barrier of claim 10, wherein one or more of the polymer films is in the form of a filter that inhibits the flow of the particles through the polymer film and allows the passage of the gas through the polymer film.

12. The insulating barrier of claim 10 , wherein one of the polymer films covers a portion of the particle-trapping layer opposite the insulating layer.

13. The insulating barrier of claim 10 , wherein one of the polymer films covers a portion of the insulating layer and the particle-trapping layer.

14. 10. The insulation barrier of claim 1, wherein the insulation layer has a thermal conductivity through a thickness dimension of the insulation layer of less than about 50 mW / m·K at 25° C. and less than about 60 mW / m·K at 600° C.

15. The insulating barrier of claim 1 , wherein the insulating layer comprises an aerogel.

16. The insulating barrier of claim 1 , wherein the encapsulation layer comprises a polymeric material.

17. The insulating barrier of claim 1 , wherein the encapsulation layer comprises a polymeric material and a metal layer embedded in the polymeric material.

18. A battery module, A plurality of battery cells; and one or more insulating barriers according to any one of claims 1 to 17, wherein at least one insulating barrier is disposed between adjacent battery cells.

19. 20. A power system comprising one or more battery modules according to claim 18.

20. 20. A device or vehicle comprising the battery module of claim 18.

21. 21. The device of claim 20, 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 range finder, a digital communication device, a secret intelligence gathering sensor, an electronic integrated garment, a night vision device, a power tool, a calculator, a radio, a remote control device, a GPS device, a handheld and portable television, a car starter, a flashlight, a sound device, a portable heating device, a portable vacuum cleaner, or a portable medical tool.

22. 21. The vehicle of claim 20, wherein the vehicle is an electric vehicle.

Images