Petmultiplex and embossed aerogel processing

Abstract

An aerogel composite sheet material and associated methods are disclosed. In one aspect, an aerogel composite sheet material includes a plurality of individual fiber sheets arranged in a stack, and a matrix including an aerogel surrounding the plurality of individual fiber sheets. In one aspect, an aerogel composite sheet material includes a fiber sheet and a matrix including an aerogel surrounding the fiber sheet. The aerogel composite sheet material can include an exposed major surface that includes a fracture surface.

Description

PETMULTIPLEX AND EMBOSSED AEROGEL PROCESSINGClaim of priority

[0001] This patent application claims the benefit of priority, under 35 U.S.C. § 119(e), to U.S. Provisional Patent Application Serial No. 63 / 453,388, entitled “MULTIPLEX AND EMBOSSED AEROGEL PROCESSING,” filed on March 20, 2023, which is hereby incorporated by reference herein in its entirety.Technical Field

[0002] The present disclosure relates generally to composite sheets that provide thermal isolation. In one particular example, materials and methods are described for preventing or mitigating thermal events, such as thermal runaway issues, in energy storage systems. In particular, the present disclosure provides thermal barrier materials. The present disclosure further relates to a battery system or pack with one or more battery cells that includes the thermal barrier materials, as well as systems including those battery systems or packs.Background

[0003] Thermal barriers are used in a number of heat related applications. One important application includes lithium-ion batteries, where thermal barriers are used to provide isolation between adjacent cells and external components. The thermal barrier isolation improves safety in the event of a thermal runaway event that may happen in one or more cells of a battery module. Although lithium-ion batteries are described as one aspect use of thermal barriers in the present disclosure, the present disclosure is not so limited.

[0004] 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 because of their high working voltage, low memory effects, and high energy density compared to traditional batteries. However, safely is a concern as LIBs are susceptible to catastrophic failure under “abuse conditions” such as when a rechargeable battery isovercharged (being charged beyond the designed voltage), over-discharged, operated at or exposed to high temperature and high pressure.

[0005] To prevent cascading thermal runaway events from occurring, there is a need for effective insulation and heat dissipation strategies to address these and other technical challenges of LIBs.Brief Description of the Drawings

[0006] FIG. 1 A shows a battery’ system in accordance with some aspects.

[0007] FIG. IB shows a cross section of the battery system from Figure1A in accordance with some aspects.

[0008]

[0009] FIG. 2 shows a stack of composite sheet material in accordance with some aspects.

[0010] FIG. 3 shows an aerogel composite sheet material in accordance with some aspects.

[0011] FIG. 4 shows another example of an aerogel composite sheet material in accordance with some aspects.

[0012] FIG. 5A shows another example of an aerogel composite sheet material in accordance with some aspects.

[0013] FIG. 5B shows a close up view of an aerogel composite sheet material with a fracture surface in accordance with some aspects.

[0014] FIG. 5C shows a close up view of an aerogel composite sheet material with a fracture surface in accordance with some aspects.

[0015] FIG. 5D shows pictures of an aerogel composite sheet material in accordance with some aspects.

[0016] FIG. 6 shows a fiber sheet in accordance with some aspects.

[0017] FIG. 7 shows a magnified view of a fiber sheet in accordance with some aspects.

[0018] FIG. 8 shows a schematic close up view of another fiber sheet in accordance with some aspects.

[0019] FIG. 9 shows an aerogel composite sheet material in accordance with some aspects.

[0020] FIG. 10 shows another example of an aerogel composite sheet material in accordance with some aspects.

[0021] FIG. 11 shows another example of an aerogel composite sheet material in accordance with some aspects.

[0022] FIG. 12 shows another example of an aerogel composite sheet material in accordance with some aspects.

[0023] FIG. 13 shows a flow chart of a method in accordance with some aspects.

[0024] FIG. 14 shows a flow chart of another method in accordance with some aspects.

[0025] FIG. 15 shows an electronic device in accordance with some aspects.

[0026] FIG. 16 shows an electric vehicle in accordance with some aspects.

[0027] FIG. 17 shows selected operations of forming an aerogel composite in accordance with some aspects.Description of Embodiments

[0028] The following description and the drawings sufficiently illustrate specific 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, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims.

[0029] Insulation materials, and reinforced insulation materials as described in aspects below, can be used as a single heat resistant layer, or in combination with other layers that provide additional function to a multilayer configuration, such as mechanical strength, compressibility, heat dissipation / conduction, etc. Insulation layers described are responsible for reliably containing and controlling heat flow from heat-generating parts in small spaces and to provide safety and prevention of fire propagation for such products in the fields of electronic, industrial and automotive technologies.

[0030] In many aspects of the present disclosure, the insulation layer functions as a flame / fire deflector layer either by itself or in combination with other materials that enhance performance of containing and controlling heat flow. For example, the insulation layer may itself be resistant to flame and / orhot gases and further include entrained particulate materials that modify or enhance heat containment and control.

[0031] One aspect of a highly effective insulation layer includes an aerogel. Aerogels describe a class of material based upon their structure, namely low density, open cell structures, large surface areas (often 900 m2 / g or higher) and subnanometer scale pore sizes. The pores may be filled with gases such as air. Aerogels can be distinguished from other porous materials by their physical and structural properties. Although an aerogel material is an exemplary insulation material, the present disclosure is not so limited. Other thermal insulation material layers may also be used in aspects of the present disclosure.

[0032] Selected aspects of aerogel formation and properties are described. In several aspects, a precursor material is gelled to form a network of pores that are filled with solvent. The solvent is then extracted, leaving behind a porous matrix. A variety of different aerogel compositions are known, and they may be inorganic, organic and inorganic / organic hybrid. Inorganic aerogels are generally based upon 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.

[0033] Inorganic aerogels may be formed from metal oxide or metal alkoxide materials. The metal oxide or metal alkoxide materials may be based on oxides or alkoxides of any metal that can form oxides. 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 (such as tetraethoxylsilane), or via gelation of silicic acid or water glass. Other relevant inorganic precursor materials for silica based aerogel synthesis include, but are not limited to metal silicates such as sodium silicate or potassium silicate, alkoxysilanes, partially hydrolyzed alkoxysilanes, tetraethoxylsilane (TEOS), partially hydrolyzed TEOS, condensed polymers of TEOS, tetramethoxylsilane (TMOS), partially hydrolyzed TMOS, condensed polymers of TMOS, tetra-n- propoxysilane, partially hydrolyzed and / or condensed polymers of tetra-n- propoxysilane, polyethylsilicates, partially hydrolyzed poly ethy silicates, monomeric alkydalkoxy silanes, bis-trialkoxy alkyl or aryl silanes, polyhedral silsesquioxanes, or combinations thereof.

[0034] In certain embodiments of the present disclosure, pre-hydrolyzed TEOS, such as Silbond H-5 (SBH5, Silbond Corp), which is hydrolyzed with a water / silica ratio of about 1.9-2, may be used as commercially available or may be further hydrolyzed prior to incorporation into the gelling process. Partially hydrolyzed TEOS or TMOS, such as polyethysilicate (Silbond 40) or polymethylsilicate may also be used as commercially available or may be further hydrolyzed prior to incorporation into the gelling process.

[0035] Inorganic aerogels can also include gel precursors comprising at least one hydrophobic group, such as alkyl metal alkoxides, cycloalkyl metal alkoxides, and aryl metal alkoxides, which can impart or improve certain properties in the gel such as stability and hydrophobicity. Inorganic silica aerogels can specifically include hydrophobic precursors such as alkylsilanes or arylsilanes. Hydrophobic gel precursors may be used as primary precursor materials to form the framework of a gel material. However, hydrophobic gel precursors are more commonly used as co-precursors in combination with simple metal alkoxides in the formation of amalgam aerogels. Hydrophobic inorganic precursor materials for silica based aerogel synthesis include, but are not limited to trimethyl methoxysilane (TMS), dimethyl dimethoxysilane (DMS), methyl trimethoxy silane (MTMS). trimethyl ethoxysilane, dimethyl diethoxysilane (DMDS), methyl triethoxysilane (MTES), ethyl triethoxysilane (ETES), diethyl diethoxysilane, dimethyl diethoxysilane (DMDES), ethyl triethoxysilane, propyl trimethoxysilane, propyl triethoxysilane, phenyl trimethoxysilane, phenyl triethoxysilane (PhTES), hexamethyldisilazane and hexaethyldisilazane, and the like. Any derivatives of any of the above precursors may be used and specifically certain polymeric of other chemical groups may be added or cross-linked to one or more of the above precursors.

[0036] Organic aerogels are generally formed from carbon-based polymeric precursors. Such polymeric materials include, but are not limited to resorcinol formaldehydes (RF). polyimide, polyacrylate, polymethyl methacrylate, acrylate oligomers, polyoxyalkylene, polyurethane, polyphenol, polybutadiane, trialkoxysilyl-terminated polydimethylsiloxane, polystyrene, polyacrylonitrile, polyfurfural, melamine-formaldehyde, cresol formaldehyde, phenol-furfural. polyether, polyol, polyisocyanate, polyhydroxybenze, polyvinyl alcohol dialdehyde, polycyanurates, polyacrylamides, various epoxies, agar.agarose, chitosan, and combinations thereof. As one aspect, organic RF aerogels are typically made from the sol-gel polymerization of resorcinol or melamine with formaldehyde under alkaline conditions.

[0037] Organic / inorganic hybrid aerogels are mainly comprised of (organically modified silica (“ormosil’') aerogels. These ormosil materials include organic components that are covalently bonded to a silica network. Ormosils are typically formed through the hydrolysis and condensation of organically modified silanes, R— Si(OX)s, with traditional alkoxide precursors, Y(0X)4. In these formulas, X may represent, for example, CH3, C2H5, C3H7, C4H9; Y may represent, for example, Si, Ti, Zr, or Al; and R may be any organic fragment such as methyl, ethyl, propyl, butyl, isopropyl, methacrylate, acrylate, vinyl, epoxide, and the like. The organic components in ormosil aerogel may also be dispersed throughout or chemically bonded to the silica network.

[0038] Aerogels can be formed from flexible gel precursors. Various flexible layers, including flexible fiber-reinforced aerogels, can be readily combined and shaped to give pre-forms that when mechanically compressed along one or more axes, give compressively strong bodies along any of those axes.

[0039] One method of aerogel formation includes batch casting. Batch casting includes catalyzing one entire volume of sol to induce gelation simultaneously throughout that volume. Gel-forming techniques include adjusting the pH and / or temperature of a dilute metal oxide sol to a point where gelation occurs. Suitable materials for forming inorganic aerogels include oxides of most of the metals that can form oxides, such as silicon, aluminum, titanium, zirconium, hafnium, yttrium, vanadium, and the like. Particularly preferred are gels formed primarily from alcohol solutions of hydrolyzed silicate esters due to their ready availability and low cost (alcogel). Organic aerogels can also be made from melamine formaldehydes, resorcinol formaldehydes, and the like.

[0040] As noted above, an aerogel may be organic, inorganic, or a mixture thereof. In some aspects, the aerogel includes a silica-based aerogel. One or more layers in a thermal barrier may include a reinforcement material. The reinforcement material may be any material that provides resilience, conformability, or structural stability to the aerogel material. Aspects of reinforcement materials include, but are not limited to, open-cell macroporousframework reinforcement materials, closed-cell macroporous framework reinforcement materials, open-cell membranes (e.g open-cell foams), honeycomb reinforcement materials, polymeric reinforcement materials, and fiber reinforcement materials such as discrete fibers, woven materials, nonwoven materials, needled non-wovens, battings, webs, mats, and felts.

[0041] The reinforcement material can be selected from organic polymer-based fibers, inorganic fibers, carbon-based fibers or a combination thereof. The inorganic fibers are selected from glass fibers, rock fibers, metal fibers, boron fibers, ceramic fibers, basalt fibers, or combination thereof. In some aspects, the reinforcement material can include a reinforcement including a plurality of layers of material.

[0042] In addition to thermal insulating layers, thermally conductive layers in combination with thermal insulating layers are effective at channeling unwanted heat to a desired external location, such as external heat dissipating fins, a heat dissipating housing, or other external structure to dissipate unwanted heat to a heat sink (e.g. outside ambient air, a radiator, a high heat capacity mass). In one aspect, a thermally conductive layer or layers helps to dissipate heat away from a localized heat load within a battery system or pack. Aspects of high thermal conductivity materials include carbon fiber, graphite, silicon carbide, metals including but not limited to copper, stainless steel, aluminum, and the like, as well as combinations thereof.

[0043] To aid in the distribution and removal of heat, in at least one embodiment the thermally conductive layer is coupled to a heat sink. It will be appreciated that there are a variety of heat sink types and configurations, as well as different techniques for coupling the heat sink to the thermally conductive layer, and that 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 a multilayer structure can be in thermal communication with an element of a cooling system of a battery system or pack, such as a cooling plate or cooling channel of the cooling system.

[0044] Figure 1A shows one aspect of a battery system 100 that may include an aerogel composite sheet material. The system 100 includes one or more battery cells 102. A heat sink 104 is shown located on a side of the system 100, and in thermal communication with the battery cells 102. Figure IB showsa cross section of batery module 100. One or more of the cells 102 are shown separated by a thermal barrier 110. Although in Figure IB, only selected groups of cells 102 are separated by thermal barrier 110, the present disclosure is not so limited. In other aspects, every cell 102 is bounded by thermal barriers. Side, botom or top surfaces of the batery7module 100 may also include a thermal barrier. In one aspect, the cells 102 are lithium ion pouch cells, although the present disclosure is not so limited. Lithium ion pouch cells are frequently used in electric vehicle batery systems.

[0045] Figure 2 shows selected components of an aerogel composite sheet material. Aspects of aerogel composite sheet materials described in the present disclosure may be used as all or part of a thermal barrier 110 as shown in Figure IB. Although a thermal barrier in a batery system is used as an example, other uses apart from batery devices are within the scope of the present disclosure.

[0046] In Figure 2, a number of fiber sheets 202 are shown and arranged in a stack. In one aspect, the number of fiber sheets 202 include glass fiber veil sheets. Glass fiber veil sheets are readily available, very thin, and are easily incorporated into a manufacturing process and products as described below. Although used as an effective example, the present disclosure is not so limited. Other fiber veils such as carbon fiber veil, or other fiber weights are also within the scope of the present disclosure.

[0047] Glass fiber veil is distinguishable over glass fiber batting in a number of respects. In one aspect, glass fiber veil includes a fiber length of approximately 12mm. In one aspect, glass fiber veil includes an areal density between 2 and 200 grams per square meter. In one aspect, glass fiber veil includes an areal density between 100 and 250 g / m2with a thickness between 0.025 and 0.050 cm. In contrast, glass fiber bating may include areal density that overlaps with glass fiber veil, however, a thickness of glass fiber bating is 0.5 cm or thicker, up to several centimeters.

[0048] In one aspect, glass fiber veil is manufactured through a solutionbased paper making process, where chopped fibers (around one inch or shorter) are held together by an organic binder. In contrast, glass fiber bating includes longer fibers formed by pulling apart fiber bundles with teeth or wires. Fibers in glass fiber bating are then held together by needling or stapling, moving thefibers in the Z direction to hold the web together. Glass fiber veil and glass fiber batting are recognized in the industry as distinctly different products.

[0049] Figure 3 shows an aerogel composite sheet material 200. The aerogel composite sheet material 200 includes a matrix 204 that includes an aerogel. In one aspect, the aerogel is a monolithic aerogel matrix 204. In one aspect, the matrix 204 includes and aerogel component, such as particles or a powder of aerogel material mixed with a binder to form the matrix 204. As discussed above, a matrix 204 that includes an aerogel provides very low thermal conductivity and is especially effective at thermal isolation even at very thin thicknesses.

[0050] The matrix 204 is shown surrounding the fiber sheets 202. In one aspect a matrix is defined as a continuous phase that encapsulates a dispersed phase. In the example of Figure 3, the fibers sheets 202 are the dispersed phase, and the matrix 204 is shown encapsulating the fiber sheets 202. In the example of Figure 3, multiple fiber sheets 202 are stacked, however, the sheets 202 remain separate. The continuous matrix 204 infuses and penetrates between the fiber sheets 202, and penetrates within structure (fibers, etc.) of the sheets 202.

[0051] The matrix 204 of the aerogel composite sheet material 200 includes an exterior surface 206. In one aspect the aerogel composite sheet material 200 can be fractured along fracture surface plane 210. The resulting structure is shown as a second aerogel composite sheet 400 in Figure 4. A remaining composite sheet material 400B is left once the second aerogel composite sheet 400 is separated from the composite sheet material 200. The second aerogel composite sheet 400 includes a portion of the matrix 204 that includes a first major surface side that is the exterior surface 206, and a second major surface side that includes a fracture surface 212. The fracture surface 212 will be physically identifiable by structures such as surface roughness, sharp edges from brittle fracture, fracture patterns that follow a surface topography of the encapsulated fiber sheet 202, etc. Examples of fracture surfaces are shown in more detail in Figures 5B and 5C discussed below .

[0052] It is desirable to have thermal barriers for any number of uses that are reinforced with a structure such as fiber sheets 202. Aerogel materials, while extremely thermally insulative, can be fragile and prone to fracture. Reinforcement with one or more fiber sheets in a composite form helps tomaintain structural integrity. It is also desirable to have predictable, consistent thicknesses of an aerogel composite sheet. A thinner aerogel composite sheet can leave more space for additional cells in a battery system, which improves an amount of charge that can be stored.

[0053] In manufacturing, an aerogel composite sheet material 200 with multiple fiber sheets 202 stacked, as shown in Figure 4, can be easily manufactured, and later fractured into a number of second aerogel composite sheets 400. This manufacturing process is easier, more efficient (i.e., number of components produced per unit time), and in some embodiments, produces a more dimensionally uniform and thinner component than forming a single very thin aerogel composite sheet by itself. Additionally, this manufacturing process can be used to manufacture any of a number of selectable thicknesses of a second aerogel composite sheet 400. A fracture line 210 from Figure 3 can be chosen to select one, two, three, etc. fiber sheets 202 to be included within the second aerogel composite sheets 400. Choosing where to facture the aerogel composite sheet matenal 200 in effect selects an end thickness of the second aerogel composite sheet 400. Additionally, due to the controlled fracture line between adjacent fiber sheets 202 in the stack, a resulting consistency of thickness of the second aerogel composite sheet 400 is improved.

[0054] Figure 5A shows a third aerogel composite sheet 500 according to one aspect. The third aerogel composite sheet 500 comes from a middle of the aerogel composite sheet material 200 from Figure 3, and as a result, includes both a first fracture surface 212 and a second fracture surface 214 on opposing major surfaces of the third aerogel composite sheet 500. Although the third aerogel composite sheet 500 is shown with only a single fiber sheet 202 encapsulated by matrix 204, the present disclosure is not so limited. Other numbers of fiber sheets 202 may be included depending on a desired thickness of the third aerogel composite sheet 500.

[0055] Figures 5B and 5C show closer detail of examples of fracture surfaces. Figure 5B shows a close up view of an end of a composite sheet 510 similar to composite sheet 500 from Figure 5A. A fiber sheet 512 is shown encapsulated by aerogel 514. The aerogel 514 includes a number of pores 516 as are found in aerogels, by definition. A top surface 520 and a bottom surface 522 of the aerogel 514 are shown. Figure 5B illustrates how each of surfaces520, 522 exhibit physical features of a fracture surface as discussed above. A number of open, fractured pores 518 are visible on the top surface 520 and the bottom surface 522. In contrast, edge 524 is either sealed, or more sealed than the fractured surfaces 520, 522 because the edge 524 was cured against a side of a mold, and was not subsequently fractured. In one aspect, fractured surfaces 520, 522 include open, fractured pores 518, while non-fractured surfaces such as edge 524 do not include open, fractured pores 518. In one aspect, fractured surfaces 520, 522 include a larger number or concentration of open, fractured pores 518, while non-fractured surfaces such as edge 524 include fewer open, fractured pores 518. This physical feature distinction, among others, provides a physically distinct indication that the composite sheet 510 was formed by fracturing from a larger stack of composite sheet material such as composite sheet material 200 from Figure 3.

[0056] In one aspect, the composite sheet 510 is cut from a larger composite sheet along edges 524, and as such, surfaces 520, 522 and edge 524 all include open, fractured pores 518. However, major surfaces such as top surface 520 and bottom surface 522 will be distinctly different from reinforced aerogel sheets that were not fractured apart as shown in Figures 4 and 5A-5C.

[0057] Figure 5C shows a closer view of a fracture surface 532 of an aerogel in a composite sheet such as composite sheet 510. A number of exposed arced surfaces 534 and peaks 536 are present, resulting from fracture of an aerogel matrix in the composite sheet. In one aspect, the aerogel matrix includes a silica aerogel. Silica aerogel is particularly brittle in fracture characteristics, and when fractured, will result in the physically visible features such as open, fractured pores 518 and arced surfaces 534 and peaks 536.

[0058] Figure 5D show s an end view 540 and a top view' 550 of a composite sheet material 541. The top view 550 shows a major surface 551 of the composite sheet material 541. A plurality of stacked fiber sheets 542 are shown in the end view 540 with a number of fracture planes 544 visible between the plurality of stacked fiber sheets 542. In the end view' 540, although fracture planes 544 are visible, the stacked fiber sheets 542 are not yet completely fractured apart from one another to form an entire major surface with fracture characteristics across the entire major surface.

[0059] Figure 6 shows one aspect of a fiber sheet 602 that may be used in aerogel composite sheets as described. In the example of Figure 6, the fibers in the fiber sheet are woven into a specific pattern. Figure 7 shows another example of a fiber sheet 702 that may be used in aerogel composite sheets as described. In the example of Figure 7, the fibers in the fiber sheet are nonwoven, and are randomly oriented into a mat. Although two different configurations of fiber sheets (602. 702) are shown, the present disclosure is not so limited. Other weaves, fiber densities, etc. apart from the examples of Figures 6 and 7 are included in the scope of the present disclosure. Any of several fiber materials may be used to form fiber sheets such as fiber sheets 202, 602, and 702. Example fibers materials include, but are not limited to glass fibers, carbon fibers boron fibers, combinations of glass, carbon, boron, etc. are within the scope of the present disclosure. Another example fiber includes oxidized polyacrylonitrile (OP AN) fibers. OP AN fibers have an advantage of being inherently fire resistant, thermally stable, exhibit excellent resistance to chemicals and solvents and are electrically nonconductive.

[0060] Figure 8 shows a diagram view of a portion of a fiber sheet 802 according to another example. In one example, the fiber sheet 802 is a glass fiber veil. In the example of Figure 8, a binder material 812 is included at intersections 810 between a number of fibers in the fiber sheet 802. Examples of binder materials include, but are not limited to, poly vinyl alcohol (PVA), acry lic, styrene, and / or combinations of these etc. Binder materials at fiber intersections can be helpful in non-woven fiber sheet examples. The addition of binder materials helps hold the fiber sheet together during encapsulation with the matrix. In some examples, a binder may be used to maintain contact at intersection points of various fibers. This in turn, may provide compressive and / or dimensional resilience so that a fiber sheet 802 thus treated returns to its (approximate) shape and / or dimensions upon release of an applied force. In some examples, the binder may be a multicomponent fiber, with one polymer of a higher melting point, and lower melting point polymer on the outside. This lower melting point polymer will act as the binder. When heated, it will soften or melt, and bind to any other fibers it is in contact with.

[0061] Figure 9 shows another example of an aerogel composite sheet material 900. The material 900 includes a plurality of individual fiber sheetsarranged in a stack. In Figure 9, a first fiber sheet 902 and a second fiber sheet 904 are shown for illustration. The material 900 also includes a matrix 901 including an aerogel surrounding the plurality of individual fiber sheets.

[0062] Figure 9 further shows fiber sheets 902 and 904 coupled together along one or more connection pattern elements 906. In one aspect, the connection pattern elements can be described as quilting, although the present disclosure is not so limited. A number of different connection configurations are possible. In one aspect, the connection pattern elements 906 include stitching. In one aspect, the connection pattern elements 906 include melted and re-cooled portions of binder from within the fiber sheets 902, 904 such as binder 812 as shown in Figure 8.

[0063] Figure 10 shows another example of an aerogel composite sheet material 1000 including fiber sheets 1002 and 1004 coupled together along one or more connection pattern elements 1006. An aerogel matrix 1001 is shown encapsulation and infused within the fiber sheets 1002 and 1004. In the example of Figure 10, the connection pattern elements 1006 include a separate adhesive 1008 forming the connection pattern elements 1006. In one aspect, adhesive 1008 may be included, while a different binder 812 is used within a fiber sheet as shown in Figure 8. In one aspect, the adhesive 1008 is chosen to provide different characteristics from the binder 812 from Figure 8. In one aspect, the adhesive 1008 is chosen to better facilitate separation of sheets after encapsulation with the aerogel matrix, as shown in Figures 3, 4, and 5A-5C. PVA has been demonstrated to be particularly effective at providing sufficient binding force to form a composite sheet material 200 as shown in Figures 10-12 and Figure 3, yet weak enough to provide good separation between aerogel composite sheets as shown in Figures 4 and 5A-5C. Although PVA is used as one aspect, the disclosure is not so limited.

[0064] Any of a number of geometries or patterns of connection pattern elements 1006, 1008 are within the scope of the present disclosure. Figure 11 shows a first fiber sheet 1102 and a second fiber sheet 1104. Figure 11 shows a number of connection pattern elements 1106 that include lines. Figure 12 shows a first fiber sheet 1202 and a second fiber sheet 1204. Figure 12 shows a number of connection pattern elements 1206 that include points.

[0065] It can be difficult to fully reinforce a thicker aerogel composite material. Examples of multiple fiber sheets as described can be manufactured to a desired thickness depending on a selected stack of fiber sheets. Sheets can be attached together as described before encapsulation with a matrix. In this way, a desired end product thickness can be chosen before encapsulation with the matrix by forming the connection pattern elements in a chosen number of fiber sheets. For example, a 1mm thickness product may utilize one sheet, a 5mm thick product may utilize 5 sheets, a 10mm thickness product may utilize 10 sheets, etc. Also, in one aspect, a 10mm thickness product may be separated in a mid layer into two separate 5mm thickness products.

[0066] Any number of connection methods for the connection pattern elements are possible. As noted above, stitching or selective locations of adhesive patterns are examples of possible connection methods. In an example where each fiber sheet already includes binder, such as binder 812 from Figure 8, it is possible to merely press and heat a stack of fiber sheets at selected locations (lines, points, etc.). The heating forms connection pattern elements from the binder already present in the fiber sheets. As noted in Figure 10, an additional adhesive may also be used. Although example methods of forming connection pattern elements are discussed, the present disclosure is not so limited. Other methods of forming connection pattern elements are also within the scope of the present disclosure.

[0067] Figure 13 shows a flow diagram of an example method of manufacturing an aerogel composite sheet material. In operation 1302, a desired thickness of an aerogel composite material is selected. In operation 1304. two or more fiber sheets are stacked, wherein a number of fiber sheets stacked corresponds to the desired thickness. In operation 1306, an aerogel material is incorporated into the number of fiber sheets, and in operation 1308, the aerogel material is cured with the number of fiber sheets. As noted in examples above, the aerogel material may be monolithic, or may be a separate matrix that includes aerogel particles suspended within the matrix.

[0068] In one aspect, after the aerogel material is incorporated into the number of fiber sheets, the aerogel material is cured with the number of fiber sheets while the number of fiber sheets are compressed together along a direction normal to major surfaces of the stack. In this example, a closer controlover thickness and surface variations of the resulting composite sheet material is obtained.

[0069] Figure 14 shows another flow diagram of an example method of manufacturing an aerogel composite sheet material. In operation 1402, two or more fiber sheets are stacked. In operation 1404, an aerogel material is incorporated into the stack. In operation 1406. the aerogel material is cured with the stack to form an encapsulated stack of fiber sheets, and in operation 1408. one or more encapsulated plies are separated from the encapsulated stack of fiber sheets.

[0070] As discussed above, one end use of aerogel composite sheet materials as described includes thermal barriers within battery systems. Battery systems are used in a number of electronic devices. Figure 15 illustrates an example electronic device 1500 that includes a battery system 1510. The battery system 1510 is coupled to functional electronics 1520 by circuitry 1512. In the example shown, the battery system 1510 and circuitry 1512 are contained in a housing 1502. A charge port 1514 is shown coupled to the batten’ system 1510 to facilitate recharging of the battery system 1510 when needed.

[0071] In one aspect, the functional electronics 1520 include devices such as semiconductor devices with transistors and storage circuits. Examples include, but are not limited to, telephones, computers, display screens, navigation systems, etc.

[0072] Figure 16 illustrates another electronic system that utilizes battery systems that include multilayer thermal barriers as described above. An electric vehicle 1600 is illustrated in Figure 16. The electric vehicle 1600 includes a chassis 1602 and wheels 1622. In the example shown, each wheel 1622 is coupled to a drive motor 1620. A battery system 1610 is shown coupled to the drive motors 1620 by circuitry’ 1606. A charge port 1604 is shown coupled to the battery’ system 1610 to facilitate recharging of the battery’ system 1610 when needed.

[0073] Examples of electric vehicle 1600 include, but are not limited to, consumer vehicles such as cars, trucks, etc. Commercial vehicles such as tractors and semi-trucks are also within the scope of the present disclosure. Although a four wheeled vehicle is shown, the present disclosure is not solimited. For example, two wheeled vehicles such as motorcycles and scooters are also within the scope of the present disclosure.

[0074] Figure 17 shows a manufacturing method to produce an embossed laminated aerogel composite sheet material according to one aspect. A system 1700 is shown, including a number of source rolls 1702 of fiber sheet 1704. A number of source rolls 1702 may be selected depending on a desired thickness of a final product and / or a reinforcement strength desired.

[0075] The fiber sheets 1704 are layered together in section 1706 and moved through embossing rolls 1710. The embossing rolls 1710 include a number of protrusions 1712 that apply concentrated pressure along a pattern such as squares, triangles, a line, points, etc. as described in examples above. In one aspect, the embossing rolls 1710 and / or the protrusions 1712 may be heated to selectively melt or soften a binder in the fiber sheets 1704 or fibers in the sheets themselves. In this way, multiple fiber sheets 1704 from unembossed section 1706 are bound together.

[0076] In one aspect, an embossed pattern divides the fiber sheets 1704 from section 1706 into a number of units 1708 that are separated by pattern elements 1709. Embossed patterns in general provide improved strength that is better for reliable conveyance along feed direction 1701. Embossed patterns across the product such as elements 1709 provide reduced buckling by providing regions of stress relief. In one aspect an embossed pattern is chosen to provide a stiff middle / planar section of each unit 1708, while also providing controlled flexing at relief locations such as elements 1709.

[0077] In one aspect, an embossed pattern includes lines or other elements that are predominantly along a feed direction 1701. Embossed pattern elements that are along the feed direction 1701 provide advantages such as improved tear strength.

[0078] The system 1700 also includes an aerogel dispense unit 1720. A wet sol is dispensed onto the number of units 1708 and is infiltrated into the fiber sheets 1704. In one aspect, the embossed pattern provides channels that improve distribution and infiltration of the w et sol into the fiber sheets 1704. A finished product may then be stored on a final roll 1730. The addition of an embossed pattern in the fiber sheets 1704 provides a more stable and stiff reinforcement structure in the number of units 1708, and improves a thicknesscontrol in a final aerogel composite. The improved consistency helps improve throughput and increases a rate of manufacture.

[0079] To better illustrate the method and apparatuses disclosed herein, a non-limiting list of embodiments is provided here:

[0080] Aspect 1. An aerogel composite sheet material, comprising: a fiber sheet formed from multiple fibers; a matrix including an aerogel surrounding the fiber sheet: and an exposed major surface of the composite sheet material that includes a fracture surface across substantially all of the exposed maj or surface.

[0081] Aspect 2. The aerogel composite sheet material of aspect 1, wherein the fiber sheet includes glass fibers.

[0082] Aspect 3. The aerogel composite sheet material of aspect 1, wherein the fiber sheet includes carbon fibers.

[0083] Aspect 4. The aerogel composite sheet material of aspect 1, wherein the fiber sheet includes non-woven fibers.

[0084] Aspect 5. The aerogel composite sheet material of aspect 4, wherein the non-woven fibers include a binder to hold the fibers together.

[0085] Aspect 6. The aerogel composite sheet material of aspect 5, wherein the binder includes poly vinyl alcohol (PVA).

[0086] Aspect 7. The aerogel composite sheet material of aspect 5, wherein a fiber length within the fiber sheet is approximately 12mm.

[0087] Aspect 8. The aerogel composite sheet material of aspect 5, wherein the fiber sheet includes an areal density between 2 and 200 grams per square meter.

[0088] Aspect 9. An aerogel composite sheet material, comprising: a plurality of individual fiber sheets arranged in a stack, each sheet formed from multiple fibers; and a matrix including an aerogel surrounding the plurality7of individual fiber sheets and infused between and within the plurality of individual fiber sheets.

[0089] Aspect 10. The aerogel composite sheet material of aspect 9, wherein the plurality of individual fiber sheets includes non-woven fiber sheets.

[0090] Aspect 11. The aerogel composite sheet material of aspect 10, wherein the non-woven fiber sheets include a binder that coats fibers within an individual sheet to hold the fibers together.

[0091] Aspect 12. The aerogel composite sheet material of aspect 9, wherein multiple individual fiber sheets in the stack are coupled together along one or more connection pattern elements.

[0092] Aspect 13. The aerogel composite sheet material of aspect 12, wherein the connection pattern elements include lines.

[0093] Aspect 14. The aerogel composite sheet material of aspect 12, wherein the connection pattern elements include points.

[0094] Aspect 15. The aerogel composite sheet material of aspect 12, wherein connection pattern elements are formed from one or more components of the individual fiber sheets.

[0095] Aspect 16. The aerogel composite sheet material of aspect 12, wherein connection pattern elements are formed from a binder separate from the individual fiber sheets.

[0096] Aspect 17. A method of manufacturing an aerogel composite sheet material, comprising: selecting a desired thickness of an aerogel composite material; stacking two or more fiber sheets, wherein a number of fiber sheets stacked corresponds to the desired thickness; incorporating an aerogel material into the number of fiber sheets; and curing the aerogel material with the number of fiber sheets.

[0097] Aspect 18. The method of aspect 17, wherein curing the aerogel material includes curing to form a monolithic aerogel matrix around the number of fiber sheets.

[0098] Aspect 19. The method of aspect 17, wherein curing the aerogel material includes curing a matrix that includes aerogel particles around the number of fiber sheets.

[0099] Aspect 20. The method of aspect 17, wherein incorporating an aerogel material into the number of fiber sheets includes utilizing a binder to hold aerogel particles in the number of fiber sheets, and curing a matrix around the number of fiber sheets and aerogel particles.

[0100] Aspect 21 . A method of manufacturing an aerogel composite sheet material, comprising: stacking two or more fiber sheets to form a stack; incorporating an aerogel material into the stack; curing the aerogel material with the stack to form an encapsulated stack of fiber sheets; and separating one or more encapsulated plies from the encapsulated stack of fiber sheets.

[0101] Aspect 22. The method of aspect 21, wherein separating one or more encapsulated plies from the encapsulated stack of fiber sheets includes fracturing one or more encapsulated plies from the encapsulated stack of fiber sheets.

[0102] Aspect 23. The method of aspect 21, wherein curing the aerogel material includes curing to form a monolithic aerogel matrix around the stack.

[0103] Aspect 24. The method of aspect 21, wherein curing the aerogel material includes curing a matrix that includes aerogel particles around the stack.

[0104] Aspect 25. The method of aspect 21, wherein incorporating an aerogel material into the stack includes utilizing a binder to hold aerogel particles in the stack, and curing a matrix around the stack and aerogel particles.

[0105] Aspect 26. A battery system, comprising: a stack of lithium-ion cells; a thermal barrier located between cells in the stack of lithium-ion cells, the thermal barrier including a composite sheet material including; a fiber sheet formed from multiple fibers; a matrix including an aerogel surrounding the fiber sheet; and an exposed major surface of the composite sheet material that includes a fracture surface across substantially all of the exposed major surface.

[0106] Aspect 27. A battery system, comprising: a stack of lithium-ion cells; a thermal barrier located between cells in the stack of lithium-ion cells, the thermal barrier including; a plurality of individual fiber sheets arranged in a stack, each sheet formed from multiple fibers; and a matrix including an aerogel surrounding the plurality of individual fiber sheets.

[0107] The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to comply with 37 C.F.R. §1.72(b), to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted w ith 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 interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are herebyincorporated into the Detailed Description, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

[0108] Although an overv iew of the inventive subject matter has been described with reference to specific aspects, various modifications and changes may be made to these embodiments without departing from the broader scope of embodiments of the present disclosure. Such embodiments of the inventive subject matter may be referred to herein, individually or collectively, by the term "‘invention” merely for convenience and without intending to voluntarily limit the scope of this application to any single disclosure or inventive concept if more than one is, in fact, disclosed.

[0109] The embodiments illustrated herein are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed. Other embodiments may be used and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. The Detailed Description, therefore, is not to be taken in a limiting sense, and the scope of various embodiments is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled.

[0110] As used herein, the term “or” may be construed in either an inclusive or exclusive sense. Moreover, plural instances may be provided for resources, operations, or structures described herein as a single instance.Additionally, boundaries between various resources, operations, systems, engines, and data stores are somewhat arbitrary, and particular operations are illustrated in a context of specific illustrative configurations. Other allocations of functionality are envisioned and may fall within a scope of various embodiments of the present disclosure. In general, structures and functionality presented as separate resources in the example configurations may be implemented as a combined structure or resource. Similarly, structures and functionality presented as a single resource may be implemented as separate resources. These and other variations, modifications, additions, and improvements fall within a scope of embodiments of the present disclosure as represented by the appended claims.The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.

[0111] The foregoing description, for the purpose of explanation, has been described with reference to specific aspects. However, the illustrative discussions above are not intended to be exhaustive or to limit the possible aspects to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The aspects were chosen and described in order to best explain the principles involved and their practical applications, to thereby enable others skilled in the art to best utilize the various aspects with various modifications as are suited to the particular use contemplated.

[0112] It will also be understood that, although the terms "first, " "second,” and so forth may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first contact could be termed a second contact, and, similarly, a second contact could be termed a first contact, without departing from the scope of the present aspects. The first contact and the second contact are both contacts, but they are not the same contact.

[0113] The terminology used in the description of the aspects herein is for the purpose of describing particular aspects only and is not intended to be limiting. As used in the description of the aspects and the appended examples, the singular forms “a,” "an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term "and / or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. It will be further understood that the terms “comprises” and / or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0114] As used herein, the term “if’ may be construed to mean “when” or “upon” or “in response to determining” or “in response to detecting,” depending on the context. Similarly, the phrase "if it is determined” or "if [a stated condition or event] is detected” may be construed to mean "upondetermining” or “in response to determining” or “upon detecting [the stated condition or event]” or “in response to detecting [the stated condition or event].” depending on the context.

Claims

Claims1. An aerogel composite sheet material, comprising: a fiber sheet formed from multiple fibers; a matrix including an aerogel surrounding the fiber sheet; and an exposed major surface of the composite sheet material that includes a fracture surface across substantially all of the exposed major surface.

2. The aerogel composite sheet material of claim 1, wherein the fiber sheet includes glass fibers.

3. The aerogel composite sheet material of claim 1. wherein the fiber sheet includes carbon fibers.

4. The aerogel composite sheet material of claim 1 , wherein the fiber sheet includes non-woven fibers.

5. The aerogel composite sheet material of claim 4, wherein the non-woven fibers include a binder to hold the fibers together.

6. The aerogel composite sheet material of claim 5. wherein the binder includes poly vinyl alcohol (PVA).

7. The aerogel composite sheet material of claim 5, wherein a fiber length within the fiber sheet is approximately 12mm.

8. The aerogel composite sheet material of claim 5, wherein the fiber sheet includes an areal density7between 2 and 200 grams per square meter.

9. An aerogel composite sheet material, comprising: a plurality of individual fiber sheets arranged in a stack, each sheet formed from multiple fibers; and a matrix including an aerogel surrounding the plurality of individual fiber sheets and infused between and within the plurality of individual fiber sheets.

10. The aerogel composite sheet material of claim 9, wherein the plurality of individual fiber sheets includes non-woven fiber sheets.

11. The aerogel composite sheet material of claim 10, wherein the nonwoven fiber sheets include a binder that coats fibers within an individual sheet to hold the fibers together.

12. The aerogel composite sheet material of claim 9, wherein multiple individual fiber sheets in the stack are coupled together along one or more connection pattern elements.

13. The aerogel composite sheet material of claim 12, wherein the connection pattern elements include lines.

14. The aerogel composite sheet material of claim 12, wherein the connection pattern elements include points.

15. The aerogel composite sheet material of claim 12, wherein connection pattern elements are formed from one or more components of the individual fiber sheets.

16. The aerogel composite sheet material of claim 12, wherein connection pattern elements are formed from a binder separate from the individual fiber sheets.

17. A method of manufacturing an aerogel composite sheet material, comprising: selecting a desired thickness of an aerogel composite material; stacking two or more fiber sheets, wherein a number of fiber sheets stacked corresponds to the desired thickness; incorporating an aerogel material into the number of fiber sheets; and curing the aerogel material with the number of fiber sheets.

18. The method of claim 17, wherein curing the aerogel material includes curing to form a monolithic aerogel matrix around the number of fiber sheets.

19. The method of claim 17, wherein curing the aerogel material includes curing a matrix that includes aerogel particles around the number of fiber sheets.

20. The method of claim 17, wherein incorporating an aerogel material into the number of fiber sheets includes utilizing a binder to hold aerogel particles in the number of fiber sheets, and curing a matrix around the number of fiber sheets and aerogel particles.

21. A method of manufacturing an aerogel composite sheet material, comprising: stacking two or more fiber sheets to form a stack; incorporating an aerogel material into the stack; curing the aerogel material with the stack to form an encapsulated stack of fiber sheets; and separating one or more encapsulated plies from the encapsulated stack of fiber sheets.

22. The method of claim 21, wherein separating one or more encapsulated plies from the encapsulated stack of fiber sheets includes fracturing one or more encapsulated plies from the encapsulated stack of fiber sheets.

23. The method of claim 21, wherein curing the aerogel material includes curing to form a monolithic aerogel matrix around the stack.

24. The method of claim 21, wherein curing the aerogel material includes curing a matrix that includes aerogel particles around the stack.

25. The method of claim 21, wherein incorporating an aerogel material into the stack includes utilizing a binder to hold aerogel particles in the stack, and curing a matrix around the stack and aerogel particles.

26. A battery system, comprising: a stack of lithium-ion cells; a thermal barrier located between cells in the stack of lithium-ion cells, the thermal barrier including a composite sheet material including; a fiber sheet formed from multiple fibers; a matrix including an aerogel surrounding the fiber sheet; and an exposed major surface of the composite sheet material that includes a fracture surface across substantially all of the exposed major surface.

27. A battery system, comprising: a stack of lithium-ion cells; a thermal barrier located between cells in the stack of lithium-ion cells, the thermal barrier including; a plurality of individual fiber sheets arranged in a stack, each sheet formed from multiple fibers; and a matrix including an aerogel surrounding the plurality of individual fiber sheets.

Images