Thermal barrier reinforcement structure

Abstract

Various disclosed embodiments relate to structural features of a thermal barrier. The present disclosure includes a battery module having a stack of battery cells located within a module housing and a thermal barrier including an aerogel between at least two cells in the stack of battery cells. The thermal barrier may include a separation layer having a major planar surface. The structural features may be dispersed within the separation layer. The structural features may include a plurality of elements, each of which extends at least partially through the major planar surface.

Description

[Technical Field]

[0001] Priority claims This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 488,347, filed March 3, 2023, which is incorporated herein by reference in its entirety.

[0002] Technical Field The present disclosure generally relates to materials, systems, and methods for preventing or mitigating thermal events, such as thermal runaway problems, in energy storage systems. In particular, the present disclosure provides thermal barrier materials. The present disclosure further relates to battery modules or packs having one or more battery cells that include the thermal barrier materials, as well as systems that include these battery modules or packs. The generally described embodiments may include aerogel materials. [Background technology]

[0003] Lithium-ion batteries (LIBs) are widely used to power portable electronic devices such as mobile phones, tablets, laptops, power tools, and other high-current devices such as electric vehicles because of their high operating voltage, low memory effect, and high energy density compared to conventional batteries. However, safety concerns have arisen due to the susceptibility of LIBs to catastrophic failure under "abuse conditions," such as when rechargeable batteries are overcharged, overdischarged, operated at high temperatures and pressures, or exposed to high temperatures and pressures.

[0004] Effective insulation and heat dissipation strategies are needed to address these and other technical challenges in LIBs to prevent the occurrence of cascading thermal runaway events. Summary of the Invention

[0005] In one embodiment, a battery module includes a stack of battery cells located within a module housing and a thermal barrier between at least two cells in the stack of battery cells, the thermal barrier including an aerogel, the thermal barrier including a separation layer and structural features dispersed in the separation layer.

[0006] In an aspect, a thermal barrier for use in a battery module can include a separation layer comprising an aerogel, the separation layer configured to thermally isolate individual battery cells within the battery module, and structural features dispersed within the separation layer.

[0007] In some embodiments, a method of creating structural features in a thermal barrier comprising an aerogel can include removing a portion of the aerogel to form one or more cavities, and forming a structural feature in the one or more cavities.

[0008] In some aspects, a method of creating a structural feature in a thermal barrier comprising an aerogel can include forming the structural feature and inserting the aerogel into and around the structural feature.

[0009] The drawings are not necessarily drawn to scale, and like numbers may describe like components in different figures. Like numbers with different letter suffixes may represent different instances of like components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. [Brief explanation of the drawings]

[0010] [Figure 1A] FIG. 1A shows an example battery module. [Figure 1B] FIG. 1B shows an example battery module. [Figure 2A-2B] 2A-2B show exemplary structural features for use in thermal barriers. [Figure 3A-3C] 3A-3C show exemplary structural features of a thermal barrier made from aerogel in one example. [Figures 4A-4C] 4A-4C show exemplary structural features. [Figure 5A] FIG. 5A shows exemplary structural features of a thermal barrier having an aerogel and encapsulation. [Figure 5B] FIG. 5B shows exemplary structural features of a thermal barrier with aerogel and encapsulation. [Figure 5C] FIG. 5C shows exemplary structural features of a thermal barrier with aerogel and encapsulation. [Figure 6A] FIG. 6A shows the structural features of an example thermal barrier with aerogel. [Figure 6B] FIG. 6B shows the structural features of an example thermal barrier with aerogel. [Figure 6C] FIG. 6C shows the structural features of an example thermal barrier with aerogel. [Figure 6D] FIG. 6D shows the structural features of an example thermal barrier with aerogel. [Figures 7A-7B] 7A-7B show exemplary thermal barrier structural features with aerogel. [Figure 8A] FIG. 8A shows an exemplary thermal barrier having structural features and aerogel. [Figure 8B] FIG. 8B shows an exemplary thermal barrier having structural features and aerogel. [Figure 8C] FIG. 8C shows an exemplary thermal barrier having structural features and aerogel. [Figure 8D] FIG. 8D shows an exemplary thermal barrier having structural features and aerogel. [Figures 9A-9F] 9A-9F show thermal barriers with structural features having encapsulation in certain examples. [Figures 10A-10D] 10A-10D show structural features made from a three-dimensional web in one example. [Figures 11A-11B] 11A-11B show exemplary structural features of a thermal barrier comprising an aerogel. [Figure 12A] FIG. 12A shows an exemplary structural feature with aerogel. [Figure 12B] FIG. 12B shows an exemplary structural feature with aerogel. [Figure 12C] FIG. 12C shows an exemplary structural feature with aerogel. [Figure 12D] FIG. 12D shows an exemplary structural feature with aerogel. [Figures 13A-13B] 13A-13B show exemplary structural features with aerogel. [Figure 14] FIG. 14 shows a flow diagram of a method for fabricating a thermal barrier in one example. DETAILED DESCRIPTION OF THE INVENTION

[0011] The following description and drawings sufficiently describe particular embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, portions and features of other embodiments. The claimed embodiments encompass all available equivalents of those claims.

[0012] This disclosure describes, among other things, systems and methods relating to thermal barriers for battery modules. The thermal barriers can be aerogel-based thermal barriers, such as for within or around battery modules. Discussed herein is, among other things, the creation and use of structural features within such thermal barriers to impart shear strength and compressibility to the thermal barriers.

[0013] Thermal barriers, which may include thermal insulating layers and structures, can be used in battery modules to help regulate temperature and heat flow within such battery modules. In one aspect, lithium-ion batteries, which are often used in stacks of many battery cells, can benefit from thermal regulation to prevent thermal runaway, which can lead to potential fires, overheating, combustion, or other problems associated with high temperatures within such batteries.

[0014] Such thermal barriers may be made from thermal insulating materials (isolation, isolating, insulating, or insulating materials or layers) such as aerogel materials, as discussed in detail below. While these materials provide thermal benefits, they may also be subjected to mechanical stresses, such as during the charge and discharge process within a battery cell stack. In this case, large shear stresses may exist between the thermal barrier and adjacent battery cells and be imparted to the thermal barrier. The shear stresses may prevent the thermal barrier from disengaging from between the two battery cells. Furthermore, the materials from which the thermal barrier is made may not have the compressibility desired for large battery stacks. Improved compressibility may be desired to accommodate the expansion and contraction of battery volume during the charge and discharge process.

[0015] For this reason, the use of structural features within the thermal barrier is discussed herein. Structural features can be inserted into and around the aerogel of the thermal barrier to impart shear strength and compressibility. Structural features, in one aspect, can include dots, rods, tubes, lattices, nets, ribbons, frames, or other suitable shapes that support the structural integrity of the aerogel. These structural features, in one aspect, can be created first, and the aerogel inserted around them. Alternatively, these structural features can be formed within an already formed aerogel.

[0016] The structural features may include materials selected from a non-limiting list of foams, elastomers, thermoplastics, cross-linked polymers, amorphous and / or crystalline polymers, polymer or plastic materials, or dielectric materials, in one aspect, polyimides, polycarbonates, polyesters, fiberglass, or other suitable materials with suitable electrical and thermal properties. Each material has its own compressibility. The shear strength and compressibility of the thermal barrier can be tailored by selecting structural features of different materials.

[0017] The thermal barrier insulating materials described in the following embodiments can be used as a single heat-resistant layer or in combination with other layers that provide additional functionality in a multi-layer configuration, such as mechanical strength, compressibility, heat dissipation / conduction, etc. The insulating layers described herein are responsible for ensuring containment and control of heat flow from heat-generating components in small spaces, providing safety and fire prevention for such products in the fields of electronics, industrial, and automotive technology.

[0018] In many embodiments of the present disclosure, the insulating layer functions as a flame / fire deflector layer, either by itself or in combination with other materials that enhance its ability to contain and control heat flow. In one aspect, the insulating layer itself is flame and / or hot gas resistant and may further include entrained particulate materials that modify or enhance heat containment and control.

[0019] The insulating layer may 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, heat capacity materials, intumescent materials, aerogel materials, mineral-based barriers (e.g., mica), and inorganic thermal barriers (e.g., glass fiber-containing barriers).

[0020] One example of a highly effective insulating layer includes aerogels, which are characterized by their structure: low density, open cell structure, and large surface area (often over 900 m²). 2 This paper describes a class of materials based on their pore sizes (e.g., pore sizes of 1000 sq ft / g or greater) and sub-nanometer scale. The pores may be filled with a gas, such as air. Aerogels can be distinguished from other porous materials by their physical and structural properties. Aerogel materials are exemplary insulating materials, but the invention is not limited thereto. Other thermal insulating material layers may also be used in the examples of this disclosure.

[0021] Selected examples of aerogel formation and properties are described below. In some examples, precursor materials are gelled to form a network of solvent-filled pores. The solvent is then extracted, leaving a porous matrix. A variety of different aerogel compositions are known, and they may be inorganic, organic, and inorganic / organic hybrids. Inorganic aerogels are generally based on metal alkoxides and include materials such as silica, zirconia, alumina, and other oxides. Organic aerogels include, but are not limited to, urethane aerogels, resorcinol formaldehyde aerogels, and polyimide aerogels.

[0022] Inorganic aerogels can generally be formed from metal oxide or metal alkoxide materials. The metal oxide or metal alkoxide materials can be based on the oxide or alkoxide of any metal capable of forming an oxide. Such metals include, but are not limited to, silicon, aluminum, titanium, zirconium, hafnium, yttrium, vanadium, cerium, and the like. Inorganic silica aerogels are traditionally made via the hydrolysis and condensation of silica-based alkoxides (e.g., tetraethoxysilane) or via the gelation of silicic acid or water glass. Other relevant inorganic precursor materials for silica-based aerogel synthesis include, but are not limited to, metal silicates such as sodium silicate or potassium silicate, alkoxysilanes, partially hydrolyzed alkoxysilanes, tetraethoxysilane (TEOS), partially hydrolyzed TEOS, condensation polymers of TEOS, tetramethoxysilane (TMOS), partially hydrolyzed TMOS, condensation polymers of TMOS, tetra-n-propoxysilane, partially hydrolyzed and / or condensation polymers of tetra-n-propoxysilane, polyethylsilicate, partially hydrolyzed polyethylsilicate, monomeric alkylalkoxysilanes, bis-trialkoxyalkyl or arylsilanes, polyhedral silsesquioxanes, or combinations thereof.

[0023] In certain embodiments of the present disclosure, prehydrolyzed TEOS, such as Silbond H-5 (SBH5, Silbond Corp), which is hydrolyzed to a water / silica ratio of about 1.9 to 2, may be used commercially or may be further hydrolyzed before being incorporated into the gelation process. Partially hydrolyzed TEOS or TMOS, such as polyethyl silicate (Silbond 40) or polymethyl silicate, may also be used commercially or may be further hydrolyzed before being incorporated into the gelation process.

[0024] Inorganic aerogels can also include gel precursors containing at least one hydrophobic group, such as alkyl metal alkoxides, cycloalkyl metal alkoxides, and aryl metal alkoxides, which can impart or improve certain properties to the gel, such as stability and hydrophobicity. Inorganic silica aerogels, specifically, can include hydrophobic precursors such as alkyl silanes or aryl silanes. The hydrophobic gel precursor may be used as the primary precursor material to form the framework of the gel material. However, hydrophobic gel precursors are more commonly used as co-precursors in combination with simple metal alkoxides to form amalgam aerogels. Hydrophobic inorganic precursor materials for silica-based aerogel synthesis include, but are not limited to, trimethylmethoxysilane (TMS), dimethyldimethoxysilane (DMS), methyltrimethoxysilane (MTMS), trimethylethoxysilane, dimethyldiethoxysilane (DMDS), methyltriethoxysilane (MTES), ethyltriethoxysilane (ETES), diethyldiethoxysilane, dimethyldiethoxysilane (DMDES), ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane (PhTES), hexamethyldisilazane, and hexaethyldisilazane. Any derivatives of any of the above precursors may also be used, particularly certain polymers of other chemical groups may be added to or crosslinked with one or more of the above precursors.

[0025] Organic aerogels are generally formed from carbon-based polymer precursors. Such polymeric materials include, but are not limited to, resorcinol formaldehyde (RF), polyimides, polyacrylates, polymethyl methacrylates, acrylate oligomers, polyoxyalkylenes, polyurethanes, polyphenols, polybutadiene, trialkoxysilyl-terminated polydimethylsiloxanes, polystyrenes, polyacrylonitriles, polyfurfural, melamine-formaldehyde, cresol formaldehyde, phenol-furfural, polyethers, polyols, polyisocyanates, polyhydroxybenzenes, polyvinyl alcohol dialdehyde, polycyanurates, polyacrylamides, various epoxies, agar, agarose, chitosan, and combinations thereof. As an example, organic RF aerogels are generally prepared from the sol-gel polymerization of resorcinol or melamine with formaldehyde under alkaline conditions.

[0026] Organic / inorganic hybrid aerogels are primarily composed of organically modified silica ("ormosil") aerogels. These ormosil materials contain organic components covalently bonded to the silica network. Ormosils are typically formed by the hydrolysis and condensation of an organically modified silane, R-Si(OX)3, with a conventional alkoxide precursor, Y(OX)4. In these formulas, X can represent, for example, CH3, CH5, CH7, or CH9; Y can represent, for example, Si, Ti, Zr, or Al; and R can be any organic fragment, such as methyl, ethyl, propyl, butyl, isopropyl, methacrylate, acrylate, vinyl, or epoxide. Additionally, the organic components in ormosil aerogels can be dispersed throughout the silica network or chemically bonded to it.

[0027] Aerogels can be formed from flexible gel precursors. Various flexible layers, including flexible fiber-reinforced aerogels, can be easily combined and shaped to obtain a preform that, when mechanically compressed along one or more axes, provides an object with high compressive strength along any of those axes.

[0028] One method of aerogel formation involves batch casting. Batch casting involves catalyzing an entire volume of sol to simultaneously induce gelation throughout that volume. Gel formation techniques involve adjusting the pH and / or temperature of a dilute metal oxide sol to a point where gelation occurs. Materials suitable for forming inorganic aerogels include oxides of most metals capable of forming oxides, such as silicon, aluminum, titanium, zirconium, hafnium, yttrium, and vanadium. Particularly preferred are gels formed primarily from alcoholic solutions of hydrolyzed silicate esters (alcogels) due to their ready availability and low cost. Organic aerogels can also be made from melamine formaldehyde, resorcinol formaldehyde, and the like.

[0029] The aerogel may be organic, inorganic, or a mixture thereof, hi some embodiments, the aerogel comprises a silica-based aerogel.

[0030] In one example, the aerogel material may be monolithic or continuous throughout the structure or layer. In another example, the aerogel material may include a composite aerogel material having aerogel particles mixed with a binder. Other additives may be included in the composite aerogel material, including, but not limited to, surfactants that aid in the dispersion of the aerogel particles within the binder. The composite aerogel slurry may be applied to a support such as a mesh, felt, or web and then dried to form a composite aerogel structure.

[0031] One or more layers within the thermal barrier may include a reinforcing material. The reinforcing material may be any material that provides recovery, compliance, or structural stability to the aerogel material. Examples of reinforcing materials include, but are not limited to, open-cell macroporous framework reinforcement materials, closed-cell macroporous framework reinforcement materials, open-cell membranes, honeycomb reinforcement materials, polymeric reinforcement materials, and fibrous reinforcement materials such as staple fibers, woven materials, nonwoven materials, needled nonwovens, battings, webs, mats, and felts.

[0032] The reinforcing material of the thermal barrier can be selected from organic polymer-based fibers, inorganic fibers, carbon-based fibers, or combinations thereof. The inorganic fibers can be selected from glass fibers, rock fibers, metal fibers, boron fibers, ceramic fibers, basalt fibers, or combinations thereof. In some examples, the reinforcing material can include a reinforcement comprising multiple layers of material.

[0033] In addition to the thermal insulation layer, the thermal barrier may further include a thermally conductive layer. The thermally conductive layer, combined with the thermal insulation layer, is effective in directing unwanted heat to a desired external location, such as external heat dissipation fins, a heat dissipation enclosure, or other external structure for dissipating the unwanted heat to the ambient air. In one example, one or more thermally conductive layers help dissipate heat from localized heat loads within the battery module or pack. Examples of highly thermally conductive materials include carbon fiber, graphite, silicon carbide, metals including, but not limited to, copper, stainless steel, aluminum, etc., as well as combinations thereof.

[0034] To aid in heat distribution and removal, in at least one embodiment, the thermally conductive layer is coupled to a heat sink. It is understood that there are various heat sink types and configurations, as well as different techniques for coupling the heat sink to the thermally conductive layer, and the present disclosure is not limited to the use of any one type of heat sink / coupling technique. For example, at least one thermally conductive layer of the multilayer materials disclosed herein may be in thermal communication with an element of a battery module or pack's cooling system, such as a cold plate or cooling channel of the cooling system. In another example, at least one thermally conductive layer of the multilayer materials described herein may be in thermal communication with other elements of the battery pack, battery module, or battery system that can function as a heat sink, such as a wall of the pack, module, or system, or with other elements of the multilayer material disposed between battery cells. Thermal communication between the thermally conductive layer of the multilayer material and the heat sink element in the battery system can enable the removal of excess heat from the cell(s) adjacent to the multilayer material to the heat sink, thereby reducing the impact, severity, or propagation of thermal events that may generate excess heat.

[0035] 1A-1B illustrate an example battery module 100. FIG. 1A illustrates an example of the battery module 100. The module 100 includes a stack of battery cells 101. In one embodiment, the stack of cells 101 includes lithium-ion cells 102. Several configurations of the lithium-ion cells 102 are possible. In one example, the stack of lithium-ion cells 102 includes lithium-ion pouch cells, although the invention is not limited thereto. A heat sink 104 is shown located on the side of the module 100 and in thermal communication with the battery cells 102. In the example of FIG. 1A, the stack of battery cells 102 is located within a module housing 106. A module cover 108 is also shown enclosing the stack of battery cells 102 within the module housing 106.

[0036] A thermal barrier 110 is shown between at least two cells in the stack of battery cells 102. In the example of FIG. 1A , a thermal barrier 110 is included between each cell in the stack of battery cells 102, although the present invention is not so limited. In one aspect, groups of cells 102 are separated by the thermal barrier 110. The inclusion of the thermal barrier 110 provides an improved level of safety during a thermal runaway event in one or more of the cells 102. In the event of a thermal runaway event, the area affected by the destruction of the failed cell 102 is contained within the area between the thermal barrier 110 and / or the module housing 106. An improved thermal barrier 110 is desired to better isolate and protect adjacent areas within the battery module 100, particularly during a thermal runaway event in one or more individual cells 102.

[0037] The heat sink 104 is shown in FIG. 1A. Examples of the heat sink 104 include, but are not limited to, a passive heat sink, such as a metal plate, and an active heat sink, such as a fluid recirculation system that removes heat to a remote location. In the example of FIG. 1A, the thermal barrier 110 mates with the heat sink within a slot or other recess. In one embodiment, the heat sink 104 is a separate component contained within the module housing 106. In one embodiment, the heat sink 104 is integrated into the bottom surface of the module housing 106.

[0038] FIG. 1B shows a cross-sectional view of the battery module 100 of FIG. 1A taken along line AA′. At least some of the cells 102 are separated by thermal barriers 110. A space 130 above the cells 102 within the module housing 106 and module cover 108 is shown. In one embodiment, the cells 102 may include a vent that directs gas into the space 130. During a thermal runaway event, thermal runaway ejecta may vent into the space 130 above the cells 102. In such an event, it is desirable to contain the high-temperature thermal runaway ejecta and prevent it from affecting adjacent cells 102. The thermal barrier 110 can contain the thermal runaway ejecta within the space 130 and prevent it from affecting adjacent battery cells 102.

[0039] 1A and 1B may, in one embodiment, include a thermal barrier 110 having one or more structural features integrated into the thermal barrier. These structural features may be integrated into the thermal barrier in various configurations, as described below.

[0040] 2A-2B illustrate an exemplary structural feature 200 for use in a thermal barrier. FIGS. 2A and 2B show different perspective views of the structural feature 200. In one embodiment, the structural feature 200 can include a group of tubes along the length or width of the thermal barrier as a reinforcing material. In one embodiment, the reinforcing material can be used as an alternative to fibrous fill, such as glass fiber, polymer fiber, or a combination thereof. In one embodiment, the reinforcing materials described herein can be applied together with fibrous fill, such as glass fiber, polymer fiber, or a combination thereof. When applied together, aerogel can be formed within the fibrous fill. In this case, both aerogel and fibrous fill can be included within the reinforcing materials disclosed herein for a thermal barrier. In the structural feature 200, the tube can help hold the insulating material in place, such as by helping to contain the aerogel powder. For example, the tube of the structural feature 200 can be dipped into an aerogel precursor. The precursor can then form an aerogel within the tube according to the process described above. In one aspect, the aerogel formation process can include one or more steps of gelation, aging, and supercritical drying. The tubes may undergo the same steps during the formation of the aerogel from the precursor.

[0041] In some examples, the tube can have regular openings. In some examples, the tube can have irregular openings. In some examples, the openings can be filled with insulating material during preparation. In some examples, the insulating material can include aerogel. In some examples, the aerogel can include a reinforcing material. In some examples, the reinforcing material can be fiberglass. In some examples, the openings can be lumens. In some examples, the openings can allow air to move through the structural feature 200 and the thermal barrier. This can aid in air flow in and out of the insulating material during compression of the thermal barrier.

[0042] In one example, the cross section of the tubes can be honeycomb shaped to add additional compressibility along the thickness (e.g., X direction) of the thermal barrier and structural feature 200. In some embodiments, the cross section of the tubes can be polygonal. In some embodiments, the cross section of the tubes can be hexagonal. Different shapes of the cross section of the tubes can provide different compressibility to the structural feature 200 and corresponding thermal barrier.

[0043] In some examples, the structural feature 200 can be made from a polymer such as polyimide, polycarbonate, polyester, or a combination thereof. In addition to the shape of the tube cross section described above, various materials can further tailor the compressibility of the thermal barrier. In one aspect, the material used for the structural feature 200 can melt and carbonize at high temperatures, such as during a thermal runaway. In this case, such a carbonized structural feature can still mechanically support the thermal barrier material.

[0044] Each of the tubes within the structural feature 200 can have a diameter (H1) of about 0.1 mm to about 50 mm, in one embodiment. The structural feature 200 can have a thickness (T1) of about 0.2 mm to about 50 mm. In one embodiment, the thickness T1 can be about 1 to about 100 times the diameter H1. The larger the ratio of thickness T1 to diameter H1, the greater the number of tubes within the structural feature 200, resulting in greater compressibility. A smaller ratio of thickness T1 to diameter H1 facilitates processability, particularly during immersion of the aerogel precursor within the structural feature 200, due to the relatively large tube diameter H1. In some embodiments, thickness T1 may be about 50 mm, while diameter H1 may be about 0.5 mm, or thickness T1 may be about 30 mm, while diameter H1 may be about 3 mm, or thickness T1 may be about 15 mm, while diameter H1 may be about 0.5 mm, or thickness T1 may be about 10 mm, while diameter H1 may be about 0.2 mm, or thickness T1 may be about 10 mm, while diameter H1 may be about 10 mm, or thickness T1 may be about 5 mm, while diameter H1 may be about 0.5 mm, or thickness T1 may be about 2 mm, while diameter H1 may be about 0.3 mm.

[0045] 3A-3C illustrate a thermal barrier including structural feature 300 and aerogel 310 in one embodiment. Aerogel 310 can be an aerogel in one embodiment and is correspondingly referred to hereinafter as aerogel 310. However, aerogel 310 can also be any other suitable insulating material or composition. Structural feature 300 can be similar to structural feature 200 described above. In the example of FIG. 3A, structural feature 300 can be contained within or embedded in aerogel 310. Aerogel 310 can form the outer surface of the thermal barrier. In FIG. 3B, structural feature 300 can extend partially beyond aerogel 310. Both structural feature 300 and aerogel 310 can form the outer surface of the thermal barrier. In FIG. 3C, structural feature 300 can surround aerogel 310. Structural feature 300 can form the outer surface of the thermal barrier.

[0046] 3B, the outer surface of the tube of structural feature 300 may face outward on one or more surfaces of the thermal barrier, such as to allow contact between the tube and one or more adjacent battery cells. This configuration may engage adjacent battery cells and provide additional shear force to help prevent the thermal barrier from disengaging from between two adjacent battery cells and / or allow shear force to be transferred through the thermal barrier from one adjacent battery cell to another adjacent battery cell.

[0047] In some cases, the tubes of structural feature 300 may be stacked and oriented so that one or more concave surfaces face the exterior surface of the thermal barrier. In this case, the concave surfaces may potentially align with the edges of the thermal barrier of aerogel 310 (FIG. 3A). The aerogel 310 may fill the concave portions and form the flat major surfaces of the thermal barrier. In some embodiments, the method for manufacturing the configuration of FIG. 3A may be less complex (e.g., a simpler process) than the methods used to manufacture other configurations, such as those shown in FIGS. 3B and 3C. In some cases, the concave surfaces may not align with the edges of the aerogel (FIG. 3B). In some embodiments, this configuration may allow for increased shear forces applied between the structural feature and adjacent battery cells without substantial damage to the structural feature. In some cases, the concave surfaces may be exposed to the exterior of aerogel 310 (FIG. 3C). In some embodiments, this configuration can be effective in containing particulate material, eg, dust, that may be generated by insulating material, eg, aerogel 310, within structural feature 300.

[0048] 4A-4C illustrate an exemplary structural feature 400. A perspective view of structural feature 400 is shown in FIG. 4A. Side views of structural feature 400 are shown in FIGS. 4B and 4C. While structural features 200 and 300 described above include multiple tubes whose lengths (e.g., in the Y direction) may extend across a longer length (e.g., in the Y direction) of the thermal barrier, the lengths (e.g., in the X direction) of the tubes of structural feature 400 instead extend across a shorter thickness (e.g., in the X direction) of the thermal barrier comprising insulating material 410. In one aspect, the lengths of the tubes of structural feature 400 may extend perpendicular to the largest surface (e.g., in the YZ plane) of the thermal barrier.

[0049] Structural feature 400 may provide increased shear force to adjacent battery cells compared to the configuration described with respect to FIGS. 2A and 2B, where the length of the tube (Y direction) may extend within the major surface of the thermal barrier (YZ plane). This is because the honeycomb-shaped cross-section of the tube in the configuration of FIG. 4A may provide improved shear force compared to the peripheral surface of the tube in the configuration of FIG. 2A. Furthermore, the tube of structural feature 400 may extend its length along the thickness of the thermal barrier, allowing for improved expansion characteristics along the thermal barrier's largest surface (YZ plane). Expansion of the honeycomb-shaped cross-section in the YZ plane ( FIG. 4A ) may be easier than length expansion in the YZ plane ( FIG. 2A ). Structural feature 400 may also provide increased pressure to accommodate expansion of adjacent battery cells over cycles and lifetime compared to the configuration in FIG. 2A. This is because compressing the tube along its length (X direction) in FIG. 4A is more difficult than compressing it across its cross section (XZ plane) in FIG. 2A.

[0050] In some embodiments of the structural feature 400, the tubes can extend along the entire thickness of the thermal barrier, as shown in FIG. 4C. In some embodiments of the structural feature 400, the tubes can extend along a portion of the thickness of the thermal barrier, as shown in FIG. 4B. The configuration of FIG. 4C can provide lower thermal conductivity than the configuration of FIG. 4B because it includes more insulating material 410 compared to the configuration of FIG. 4B. The configuration of FIG. 4B is "less dusty" because the insulating material 410, which typically contributes to dust, can be included within the structural feature 400. The outside of the thermal barrier, which may contact adjacent battery cells, can be formed from structural features that have less dust than the insulating material 410 included therein.

[0051] 5A-5C illustrate an exemplary structural feature 500 for use in a thermal barrier having an insulating material 510 and an encapsulation layer 512. The structural feature 500 may include curved plates, as shown in FIG. 5A. Each of the curved plates of the structural feature 500 may be zigzag, such as between two horizontal planes (e.g., between parallel YZ planes). The insulating material 510 may be formed within the structural feature 500. The encapsulation layer 512 contains particulate material, e.g., dust, that may be generated by the insulating material 510 within the structural feature 500.

[0052] In some cases, as shown in FIG. 5A, the curved plate may have one or more parallel strip portions 502 in the horizontal (YZ) plane, such as aligned with the YZ plane. In one embodiment, the structural feature 500 can include multiple layers (e.g., three layers in FIG. 5A ) of parallel strip portions in a plane parallel to the YZ plane. The parallel strip portions 502 can serve as a base to support the zigzag portions of the structural feature 500. The zigzag portions can provide compressibility in the thickness direction (X direction) of the thermal barrier. The elastic layer can accommodate the volumetric expansion and contraction of adjacent battery cells during charge and discharge processes.

[0053] 5B, the structural features 500 may be embedded in an insulating material 510, such as the aerogel material described above. The insulating material 510 may form the outer surface of the thermal barrier.

[0054] 5C, such horizontal surfaces may be extended to contact one another, thus forming an encapsulation layer 512. Such an encapsulation layer 512 may, in one embodiment, be disposed on the largest surface (YZ plane) of the thermal barrier. In some embodiments, the thermal barrier may include an encapsulation layer 512 on the parallel strip portions 502. The encapsulation layer 512 prevents dust from entering the insulating material 510.

[0055] 6A-6D illustrate a structural feature 600 within a thermal barrier having an insulating material 610, such as aerogel. FIG. 6A illustrates a perspective view, FIGS. 6B and 6C illustrate side views from the Y and Z directions, respectively, and FIG. 6D illustrates a top view of the structural feature 600 from the X direction. Here, the structural feature 600 is similar to that described with reference to FIGS. 5A and 5B above, except that the outermost parallel strip portions 502 may be exposed at the surface of the thermal barrier to increase shear forces, and may include one or more curved or zigzag plates. The plates may be arranged to provide a lattice structure.

[0056] In the embodiments of FIGS. 6A-6D, the structural feature 600 extends beyond the insulating material 610 of the thermal barrier, and a portion of the structural feature 600, such as a strip, angle, or polygon, may extend outward from the outer surface of the thermal barrier. In some embodiments, the side of the structural feature 600 in the XZ plane may be exposed as the outer surface of the thermal barrier. In some embodiments, the polygonal surface of the structural feature 600 of FIG. 6C may be exposed. In some cases, as shown in FIG. 6D, parallel strips 602 may be used in the structural feature 600. A portion of the parallel strips may extend beyond the insulating material 610 and be exposed as the outer surface of the thermal barrier. The exposed surface of the structural feature 600 can improve shear forces between the thermal barrier and adjacent components, such as a battery cell.

[0057] In some cases, the cross section of the structural feature 600 may include a parallelogram, in which case the corners of the parallelogram may be flattened to connect with adjacent curved plates.

[0058] 7A-7B illustrate an exemplary thermal barrier structural feature 700 having an insulating material 710 (e.g., aerogel). In the example of FIGS. 7A-7B, the thermal barrier structural feature 700 may include curved cables, such as cables with rounded peaks and valleys. The cables of the thermal barrier structural feature 700 may be arranged such that the curves extend along a plane (the XY plane) and are parallel to one another. In some embodiments, adjacent curved cables within the structural feature 700 may be offset from one another by a semicircle along the Y direction. The thermal barrier structural feature 700 may include several curved cables that are symmetrical along a central axis (the Y axis). In one embodiment, the curved cables may be sinusoidally curved.

[0059] Insulating material 710 can be formed within the thermal barrier structural feature 700. In some embodiments where the insulating material is an aerogel, the aerogel precursor can be a sol incorporated by the thermal insulation material 700, such as by dipping, painting, brushing, spraying, or other suitable method, followed by gelling, aging, and drying. In some cases, the aerogel insulating material 710 can be mixed with additives such as a solution, binder, or the like. In some cases, the aerogel insulating material 710 can include a reinforcing material, such as a fiberglass reinforcement material or a foam reinforcement material. The aerogel insulating materials of the structural features of other embodiments discussed herein can be similarly applied.

[0060] 8A-8D show one embodiment of a thermal barrier comprising a structural feature 800 and an insulating material such as aerogel 810. In the embodiment of Figures 8A-8D, structural feature 800 can be made from a cable that curves along the thermal barrier, similar to that discussed with reference to Figures 7A-7B above.

[0061] Structural feature 800 can have portions 812 that extend beyond aerogel 810 on one or more surfaces. In one embodiment, extended portions 812 of structural feature 800 can extend beyond the surface of aerogel 810 to provide additional shear force between the thermal barrier and adjacent components of the battery pack, such as the battery cell. In some embodiments where the cross section is elliptical, the top of the ellipse can extend beyond aerogel 810.

[0062] Structural feature 800 can have circular cross-sections, as seen in the side view of FIG. 8B along the Z direction. These circular cross-sections are aligned to form channels through which aerogel 810 can be dispersed. Another side view in FIG. 8C shows a view along the length of the curved cables along the Y direction. FIG. 8D shows a top view of the curved cables aligned with one another along the X direction. In some embodiments, every other curved cable is offset from one another.

[0063] 9A-9B show a thermal barrier having a structural feature 900 with an encapsulation 920. The structural feature 900 can be made from curved surfaces. The curved surfaces form tubes along the Z direction, similar to those described above with reference to FIGS. 8A-8D. FIGS. 9A-9B show perspective views of the structural feature 900, where the length of the tube (Z direction) can be parallel to one of the shorter edges (Z direction) of the thermal barrier. FIGS. 9D-9E show perspective views of the structural feature 900, where the length of the tube (Z direction) can be parallel to the longest edge (Z direction) of the thermal barrier. FIGS. 9C and 9F show side views of the structural feature 900.

[0064] One or more sides of the structural feature 900 may be encapsulated, such as by an encapsulation 920. In Figures 9A-9C, the curved surface of the structural feature 900 may extend across the thickness of the thermal barrier. Curved cables may be stacked to form an interconnected multi-layer structural feature 900. The stacked curved surfaces may together form one or more channels (or tubes), such as extending along the thermal barrier, either parallel to the shorter edge of the thermal barrier along the Z direction (Figures 9A-9C) or parallel to the longer edge of the thermal barrier along the Z direction (Figures 9D-9F). Aerogel may be dispersed within the channels. These channels may have circular or elliptical cross sections, in one embodiment.

[0065] 10A-10D show a structural feature 1000 made from a three-dimensional web. The structural feature 1000 can be a cable web that is expandable in three dimensions. An insulating material, such as aerogel 1010, can be within and around the structural feature 1000. An encapsulation 1020 can be used on one or more sides of the structural feature 1000.

[0066] In some embodiments, the cable web of structural feature 1000 may include curved cables. In some cases, the curved cables may be angled relative to the central plane of the thermal barrier. In one embodiment, the curved cables may be angled at approximately 45 degrees relative to the central XY plane of the thermal barrier. The curved cables within the web, in one embodiment, may be mirror images of each other along such a plane. In some cases, the curved cables within the web may lie parallel to such a plane, such as the cables in FIGS. 7A-8A.

[0067] The aerogel 1010 can be formed within the web of structural features 1000. In one embodiment, the aerogel 1010 can be formed in situ, such as by a sol-gel and drying process, or by powder forming aerogel. Such aerogels can be formed into a web by slurrying, using binders, solutions, and other additives as needed.

[0068] The aerogel 1010 may be encapsulated by encapsulation 1020 on one or more surfaces of the thermal barrier. In one embodiment, two opposing major surfaces may be encapsulated (FIG. 10C). In some embodiments, four surfaces may be encapsulated. In some embodiments, all six surfaces may be encapsulated (FIG. 10D).

[0069] 11A-11B show an exemplary structural feature 1100 of a thermal barrier having an insulating material such as aerogel 1110. In this example, the structural feature 1100 may be a web, such as a curved cable, in one embodiment, such as that described with reference to FIGS. 10A-10D above. In the structural feature 1100, the aerogel 1110 may fill or partially fill the structural feature 1100. In one embodiment, a portion of the curved cable of the structural feature 1100, such as a curved ridge, may extend beyond the aerogel 1110. A structural feature 1100 in which the aerogel 1110 is pulled out from the outermost surface of the structural feature 1100 can allow for greater shear forces within the thermal barrier, such as greater shear forces against adjacent battery cells or other components.

[0070] 12A-12D show an exemplary structural feature 1200 having an aerogel 1210. FIG. 12A shows a perspective view of structural feature 1200. FIG. 12D shows a top view of structural feature 1200 along the X direction. FIGS. 12B and 12C show side views of structural feature 1200 along the Y and Z directions, respectively. In the views of FIGS. 12C and 12D, the cross section of structural feature 1200 is elliptical. In the view of FIG. 12B, the cross section of structural feature 1200 is a parallelogram. Portion 1202 of structural feature 1200 is exposed outside of aerogel 1210.

[0071] In some embodiments, structural feature 1200 may be made from fibers of different diameters, lengths, cross-sectional shapes, the same fiber may have different diameters along its length, the diameter may change gradually or suddenly along the length of the fiber, and the fiber lengths may extend in different directions along the length of the fiber.

[0072] 13A-13B show an exemplary structural feature 1300 having an insulating material such as aerogel 1310. Structural feature 1300 can be a reticulated material such as a reticulated foam, reticulated fiber, reticulated resin, or reticulated polymer. In this embodiment, structural feature 1300 can be embedded in aerogel 1310. In one embodiment, the reticulated material can include interlaced ribbons or cables woven together randomly, forming voids between the interlaced ribbons or cables.

[0073] 14 shows a flow diagram of a method 1400 of fabricating a thermal barrier. The method 1400 may include forming a structural feature (block 1410) and inserting an aerogel into and around the structural feature (block 1420).

[0074] Inserting the aerogel (block 1420) may involve in-situ formation of the aerogel, such as by applying a sol-gel process and appropriate drying. In some cases, the method may involve preparing the aerogel powder in a slurry, in which case appropriate binders and additives may be used. Such a sol-gel or aerogel slurry may be inserted into and around already formed structural features, or structural features may be formed in and around already formed aerogel.

[0075] Various notes and examples Aspect 1 is a battery module including: a stack of battery cells positioned within a module housing; and a thermal barrier comprising aerogel between at least two cells in the stack of battery cells, the thermal barrier including: a separation layer having a major planar surface; and structural features dispersed in the separation layer, the structural features including a plurality of elements, each of the plurality of elements extending at least partially through the major planar surface.

[0076] In Example 2, the subject matter of Example 1 optionally includes wherein the separating layer comprises an aerogel.

[0077] In Example 3, the subject matter of any one or more of Examples 1-2 optionally includes wherein the separation layer includes a second major planar surface opposite the first major planar surface.

[0078] In Example 4, the subject matter of any one or more of Examples 1-3 optionally includes wherein the separation layer includes a thickness extending between the first major planar surface and the second major planar surface.

[0079] In Aspect 5, the subject matter of Aspect 4 optionally includes wherein the plurality of elements are embedded in the thickness.

[0080] In Example 6, the subject matter of any one or more of Examples 4-5 optionally includes where at least a portion of the plurality of elements extends outside the thickness.

[0081] In Example 7, the subject matter of any one or more of Examples 1-6 optionally includes, wherein the structural feature comprises a plurality of tubes extending along the length of the thermal barrier.

[0082] In an eighth aspect, the subject matter of the seventh aspect optionally includes wherein the plurality of tubes each include a lumen.

[0083] In embodiment 9, the subject matter of any one or more of embodiments 7-8 optionally includes, wherein the plurality of tubes each include a hexagonal cross-section.

[0084] In Example 10, the subject matter of any one or more of Examples 7-9 optionally includes, wherein the plurality of tubes each include one or more openings through which the aerogel particles can pass.

[0085] In Example 11, the subject matter of any one or more of Examples 7-10 optionally includes, wherein the plurality of tubes each include a diameter in the range of about 0.01% to about 100% of the thickness of the structural feature.

[0086] In Example 12, the subject matter of Example 11 optionally includes wherein the structural feature comprises a thickness of about 0.1 mm to about 10 mm.

[0087] In Example 13, the subject matter of any one or more of Examples 7-12 optionally includes, where one or more outer surfaces of a portion of the plurality of tubes are exposed to an adjacent battery cell.

[0088] In Example 14, the subject matter of any one or more of Examples 7-13 optionally includes, wherein the aerogel coats one or more exterior surfaces of a portion of the plurality of tubes.

[0089] In Example 15, the subject matter of any one or more of Examples 7-14 optionally includes, wherein the structural feature includes a plurality of concave surfaces facing one or more adjacent battery cells.

[0090] In Example 16, the subject matter of Example 15 optionally includes wherein the concave surface is filled with the aerogel.

[0091] In Example 17, the subject matter of any one or more of Examples 7-16 optionally includes wherein the thermal barrier includes a major surface and a minor surface perpendicular to the major surface, the major surface and the minor surface forming a right angle when they intersect with each other.

[0092] In Example 18, the subject matter of Example 17 optionally includes wherein the plurality of tubes extend parallel to the major surface.

[0093] In Example 19, the subject matter of any one or more of Examples 17-18 optionally includes wherein the plurality of tubes extend parallel to the minor surface.

[0094] In Example 20, the subject matter of any one or more of Examples 1-19 optionally includes, wherein the structural feature comprises one or more curved plates within the thermal barrier.

[0095] In Example 21, the subject matter of Example 20 optionally includes wherein the structural feature includes one or more horizontal plates located on either side of the one or more curved plates.

[0096] In Example 22, the subject matter of any one or more of Examples 20-21 optionally includes, wherein the one or more curved plates are stacked on top of each other within the thermal barrier.

[0097] In Example 23, the subject matter of any one or more of Examples 1-22 optionally includes, wherein the structural feature includes a lattice structure.

[0098] In Example 24, the subject matter of any one or more of Examples 1-23 optionally includes, wherein the structural feature comprises a cross-shaped structure.

[0099] In Example 25, the subject matter of any one or more of Examples 1-24 optionally includes, wherein the structural feature includes one or more portions having a plurality of polygonal cross sections.

[0100] In Example 26, the subject matter of any one or more of Examples 1-25 optionally includes, wherein the structural feature includes one or more portions having a cross section of a plurality of parallelograms.

[0101] In Example 27, the subject matter of any one or more of Examples 1-26 optionally includes, wherein the structural feature includes one or more curved cables.

[0102] In Example 28, the subject matter of Example 27 optionally includes wherein the structural feature includes one or more curved cables shaped as a sine wave.

[0103] In Example 29, the subject matter of any one or more of Examples 27-28 optionally includes wherein the one or more curved cables shaped as a sine wave include a first curved cable and a second curved cable that are offset from one another.

[0104] In Example 30, the subject matter of any one or more of Examples 27-29 optionally includes where a portion of the structural feature extends through a surface of the thermal barrier.

[0105] In Example 31, the subject matter of any one or more of Examples 27-30 optionally includes, wherein the structural feature includes one or more portions having a plurality of circular cross sections.

[0106] In Example 32, the subject matter of any one or more of Examples 27-31 optionally includes, wherein the structural feature includes one or more portions having a plurality of elliptical cross sections.

[0107] In Example 33, the subject matter of any one or more of Examples 27-32 optionally includes, wherein the structural feature includes at least two curved cables stacked horizontally adjacent to each other within the thermal barrier.

[0108] In Example 34, the subject matter of any one or more of Examples 27-33 optionally includes, wherein the structural feature includes at least two curved cables stacked vertically on top of each other within the thermal barrier.

[0109] In Example 35, the subject matter of any one or more of Examples 1-34 optionally includes, wherein the structural feature includes a three-dimensional cable web.

[0110] In Example 36, the subject matter of Example 35 optionally includes wherein the cable web is expandable in three dimensions.

[0111] In Example 37, the subject matter of any one or more of Examples 35-36 optionally includes, wherein the cable web includes a plurality of curved cables.

[0112] In Example 38, the subject matter of any one or more of Examples 35-37 optionally includes an angle from a surface of the thermal barrier.

[0113] In Example 39, the subject matter of any one or more of Examples 1-38 optionally includes, wherein the structural feature comprises a polyimide, a polycarbonate, a polyester, or a combination thereof.

[0114] In Example 40, the subject matter of any one or more of Examples 1-39 optionally includes where the aerogel is formed within the structural feature.

[0115] In Example 41, the subject matter of any one or more of Examples 1-40 optionally includes, wherein the aerogel includes, at least partially within the structural features, a powder.

[0116] In Example 42, the subject matter of any one or more of Examples 1-41 optionally includes, wherein the separation layer comprises foam at least partially within the structural feature.

[0117] In Example 43, the subject matter of any one or more of Examples 1-42 optionally includes where the aerogel is at least partially disposed within the structural feature.

[0118] In Example 44, the subject matter of any one or more of Examples 1-43 optionally includes where the thermal barrier is encapsulated in one or more surfaces.

[0119] In Example 45, the subject matter of any one or more of Examples 1-44 optionally includes, wherein the structural feature is reticulated.

[0120] In Example 46, the subject matter of any one or more of Examples 1-45 optionally includes, wherein the structural feature comprises reticulated foam.

[0121] In Example 47, the subject matter of any one or more of Examples 1-46 optionally includes, wherein the structural feature comprises a braided fiber.

[0122] In Example 48, the subject matter of any one or more of Examples 1-47 optionally includes, wherein the structural feature comprises a reticulated resin.

[0123] In Example 49, the subject matter of any one or more of Examples 1-48 optionally includes, wherein the structural feature comprises a network polymer.

[0124] In embodiment 50, the subject matter of any one or more of embodiments 1-49 optionally includes a module cover enclosing the stack of battery cells within the module housing.

[0125] Aspect 51 is a thermal barrier for use in a battery module, the thermal barrier including a separation layer configured to thermally isolate individual battery cells within the battery module, and structural features dispersed within the separation layer.

[0126] Example 52 is the subject matter of Example 51, optionally wherein the structural feature comprises a plurality of tubes extending along the length of the thermal barrier.

[0127] In Example 53, the subject matter of Example 52 optionally includes wherein the plurality of tubes each include a hexagonal cross-section.

[0128] In Example 54, the subject matter of any one or more of Examples 51-53 optionally includes, wherein the structural feature includes one or more curved cables.

[0129] In Example 55, the subject matter of any one or more of Examples 51-54 optionally includes, wherein the structural feature includes a three-dimensional cable web.

[0130] In Example 56, the subject matter of any one or more of Examples 51-55 optionally includes, wherein the structural feature comprises a polyimide, a polycarbonate, a polyester, or a combination thereof.

[0131] Embodiment 57 is a method of creating a structural feature in a thermal barrier comprising an aerogel, the method comprising forming the structural feature and inserting aerogel into and around the structural feature.

[0132] In Example 58, the subject matter of Example 57 optionally includes, wherein forming the structural features includes heat pressing structural materials together to form a web.

[0133] Each of these non-limiting aspects may stand on its own or may be combined with one or more of the other aspects in various permutations or combinations.

[0134] The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are also referred to herein as "aspects." Such aspects may include elements in addition to those shown or described. However, the inventors also contemplate aspects in which only those elements shown or described are provided. Moreover, the inventors also contemplate aspects using any combination or permutation of the elements shown or described (or one or more aspects thereof), either with respect to the particular aspect (or one or more aspects thereof) or with respect to other aspects (or one or more aspects thereof) shown or described herein.

[0135] In the event of inconsistent usage between this document and any document incorporated by reference, the usage in this document will control.

[0136] As used herein, the terms "a" or "an" are used, as is common in patent documents, to include one or more, regardless of any other instance or usage of "at least one" or "one or more." As used herein, the term "or" is used to refer to a non-exclusive or, such that "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise indicated. As used herein, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein." Also, in the following claims, the terms "including" and "comprising" are open-ended. That is, in the following claims, systems, devices, articles, compositions, formulations, or processes that include elements in addition to the elements listed after such terms are still deemed to be within the scope of the claims. Moreover, in the following claims, the terms "first," "second," and "third," etc., are used merely as labels and are not intended to impose numerical requirements on their objects.

[0137] The above description is intended to be illustrative, not limiting. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments may be employed, such as by those of ordinary skill in the art who review the above description. The Abstract is provided to enable the reader to quickly grasp the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be construed as intending that any unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter lies in less than all features of a particular disclosed embodiment. Accordingly, it is contemplated that the following claims are incorporated into the Detailed Description herein as examples or embodiments, with each claim standing on its own as a separate embodiment, and that such embodiments can be combined with each other in various combinations or variations. The scope of the invention should be determined with reference to the appended claims, along with the full range of equivalents to which such claims are entitled.

Claims

1. 1. A thermal barrier for use in a battery module, comprising: a separation layer; and structural features dispersed in the separation layer, the structural features comprising a plurality of elements.

2. The thermal barrier of claim 1 , wherein the separation layer comprises an aerogel.

3. 10. The thermal barrier of claim 1, wherein the separation layer includes a first major planar surface and a second major planar surface, the first major planar surface and the second major planar surface being on opposite surfaces of the thermal barrier.

4. The thermal barrier of claim 3 , wherein the isolation layer includes a thickness extending between the first major planar surface and the second major planar surface.

5. The thermal barrier of claim 4 , wherein the plurality of elements are embedded in the thickness.

6. The thermal barrier of claim 4 , wherein at least a portion of said plurality of elements extends outside said thickness.

7. The thermal barrier of claim 1 , wherein the structural features include a plurality of tubes extending along the length of the thermal barrier.

8. The thermal barrier of claim 7 , wherein the plurality of tubes each include a lumen.

9. The thermal barrier of claim 7 , wherein the plurality of tubes each include a hexagonal cross section.

10. The thermal barrier of claim 7 , wherein each of the plurality of tubes includes one or more openings disposed through its wall.

11. The thermal barrier of claim 7 , wherein the plurality of tubes each include a diameter ranging from about 0.01% to about 100% of the thickness of the structural feature.

12. The thermal barrier of claim 11 , wherein the structural feature comprises a thickness of from about 0.1 mm to about 10 mm.

13. The thermal barrier of claim 7 , wherein the thermal barrier is positioned adjacent to a battery cell and an outer surface of one or more of a portion of the plurality of tubes is positioned adjacent a surface of the battery cell.

14. The thermal barrier of claim 7 , wherein aerogel coats an exterior surface of one or more of a portion of the plurality of tubes.

15. The thermal barrier of claim 7 , wherein the thermal barrier is positioned adjacent to a battery cell and the structural feature comprises a plurality of concave surfaces facing the battery cell.

16. The thermal barrier of claim 15 wherein the concave surface is filled with aerogel.

17. The thermal barrier of claim 7 , wherein the thermal barrier includes a major surface and a minor surface perpendicular to the major surface, the major surface and the minor surface forming a right angle when they meet each other.

18. The thermal barrier of claim 17 , wherein the plurality of tubes extend parallel to the major surface.

19. The thermal barrier of claim 17 , wherein the plurality of tubes extend parallel to the minor surface.

20. The thermal barrier of claim 1 , wherein the structural features include one or more curved plates within the thermal barrier.

21. 21. The thermal barrier of claim 20, wherein the structural features include one or more horizontal plates located on either side of the one or more curved plates.

22. 21. The thermal barrier of claim 20, wherein the one or more curved plates are stacked on top of each other within the thermal barrier.

23. The thermal barrier of claim 1 , wherein the structural feature comprises a lattice structure.

24. The thermal barrier of claim 1 , wherein the structural feature comprises a cross-shaped structure.

25. The thermal barrier of claim 1 , wherein the structural feature comprises one or more portions having a multi-polygonal cross section.

26. The thermal barrier of claim 1 , wherein the structural feature comprises one or more portions having a cross section of a plurality of parallelograms.

27. The thermal barrier of claim 1 , wherein the structural feature comprises one or more curved cables.

28. 30. The thermal barrier of claim 27, wherein the structural feature comprises one or more curved cables shaped as a sine wave.

29. 30. The thermal barrier of claim 27, wherein the one or more curved cables shaped as a sine wave include a first curved cable and a second curved cable that are offset from one another.

30. 30. The thermal barrier of claim 27, wherein a portion of the structural feature extends beyond a surface of the thermal barrier.

31. 30. The thermal barrier of claim 27, wherein the structural feature comprises one or more portions having a plurality of circular cross sections.

32. 30. The thermal barrier of claim 27, wherein the structural feature comprises one or more portions having a plurality of elliptical cross sections.

33. 30. The thermal barrier of claim 27, wherein the structural feature comprises at least two curved cables stacked horizontally adjacent one another within the thermal barrier.

34. 30. The thermal barrier of claim 27, wherein the structural feature comprises at least two curved cables stacked vertically on top of each other within the thermal barrier.

35. The thermal barrier of claim 1 , wherein the structural feature comprises a three-dimensional cable web.

36. 36. The thermal barrier of claim 35, wherein the cable web is expandable in three dimensions.

37. 36. The thermal barrier of claim 35, wherein the cable web comprises a plurality of curved cables.

38. 36. The thermal barrier of claim 35, wherein a plurality of curved cables lie within the thermal barrier in a plane 45 degrees from a surface of the thermal barrier.

39. The thermal barrier of claim 1 , wherein the structural feature comprises a polyimide, a polycarbonate, a polyester, or a combination thereof.

40. The thermal barrier of claim 2 wherein the aerogel is formed within the structural features.

41. 3. The battery module of claim 2, wherein the aerogel comprises a powder at least partially within the structural features.

42. The thermal barrier of claim 1 , wherein the separation layer comprises foam at least partially within the structural feature.

43. The thermal barrier of claim 1 , wherein the structural feature comprises a polymer disposed at least partially within the separation layer.

44. The thermal barrier of claim 1 , wherein the thermal barrier is encapsulated on one or more surfaces.

45. The thermal barrier of claim 1 , wherein the structural feature is a mesh.

46. The thermal barrier of claim 1 , wherein the structural feature comprises reticulated foam.

47. The thermal barrier of claim 1 , wherein the structural feature comprises a fiber.

48. The thermal barrier of claim 1 , wherein the structural feature comprises a reticulated resin.

49. The thermal barrier of claim 1 , wherein the structural feature comprises a network polymer.

50. A battery module, a stack of battery cells located within a module housing; A thermal barrier comprising: an isolation layer configured to thermally isolate individual battery cells within the stack of battery cells; the thermal barrier including structural features dispersed within the separation layer.

51. 51. The battery module of claim 50, wherein the structural features include a plurality of tubes extending along the length of the thermal barrier.

52. 52. The battery module of claim 51, wherein the plurality of tubes each include a hexagonal cross section.

53. 51. The battery module of claim 50, wherein the structural features include one or more curved cables.

54. 51. The battery module of claim 50, wherein the structural feature comprises a three-dimensional cable web.

55. 51. The battery module of claim 50, wherein the structural features comprise polyimide, polycarbonate, polyester, or combinations thereof.

56. 1. A method of creating a structural feature in a thermal barrier comprising an aerogel composition, the method comprising: forming the structural feature; and forming the aerogel composition in and around the structural feature.

57. 57. The method of claim 56, wherein forming the structural features comprises heat pressing structural materials together to form a web.

Images