Thermal management multilayer sheet for batteries

Abstract

The battery assembly includes a thermal management multilayer sheet disposed on a surface of the electrochemical cell, the thermal management multilayer sheet including a thermal insulation layer, a first heat spreading layer disposed on a first side of the thermal insulation layer, and a second heat spreading layer disposed on a second side of the thermal insulation layer.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims priority to and the benefit of U.S. Provisional Application No. 62 / 977,904, filed February 18, 2020, U.S. Provisional Application No. 62 / 988,664, filed March 12, 2020, and U.S. Provisional Application No. 63 / 086,269, filed October 1, 2020, the entire contents of each of which are incorporated herein by reference. [Background technology]

[0002] The present disclosure is directed to a thermal management multilayer sheet for use in a battery, particularly for use in delaying or preventing thermal runaway in a lithium ion battery. The present disclosure is further directed to a method of making the thermal management multilayer sheet, an assembly for a battery, and a battery including the thermal management multilayer sheet.

[0003] Demand for electrochemical energy storage devices, such as lithium-ion batteries, is increasing due to the growth of applications such as electric vehicles and grid energy storage systems, as well as other multi-cell battery applications such as electric bicycles, uninterruptible power supply battery systems, and lead-acid replacement batteries. Larger applications such as grid storage and electric vehicles often use multiple electrochemical cells connected in series or parallel arrays. When a cell goes into thermal runaway mode, the heat generated by the cell can trigger a thermal runaway propagation reaction in adjacent cells, creating a cascade effect that can cause the entire battery to catch fire.

[0004] Attempts to reduce the flammability of such batteries have been explored, but many may have drawbacks. For example, modifying the electrolyte by adding non-flammable additives or using an inherently non-flammable electrolyte has been explored, but these approaches can adversely affect the electrochemical performance of the lithium-ion cell. Other approaches to preventing cascading thermal runaway include increasing the amount of insulation between cells or groups of cells to reduce the amount of heat transfer during a thermal event. However, these approaches can limit the upper limit of achievable energy density.

[0005] With the increasing demand for batteries with reduced risk of thermal runaway, there is a corresponding need for materials for use in batteries that prevent or slow the diffusion of heat, energy, or both to surrounding cells. Summary of the Invention [Means for solving the problem]

[0006] Disclosed herein is a battery assembly including a thermal management multilayer sheet disposed on a surface of an electrochemical cell, the thermal management multilayer sheet including a thermal insulation layer, a first heat spreading layer disposed on a first side of the thermal insulation layer, and a second heat spreading layer disposed on a second side of the thermal insulation layer.

[0007] A battery including the above assembly is also disclosed.

[0008] Also disclosed herein is a thermal management multilayer sheet including a first high-temperature laminate film adhered to a first side of a compressible thermal insulation layer and a second high-temperature laminate film adhered to a second, opposite side of the compressible thermal insulation layer, wherein the first high-temperature laminate film includes a first heat spreading layer disposed on a first side of the first integrity layer and a first adhesive layer disposed on a second, opposite side of the first integrity layer, the first adhesive layer adhering the first high-temperature laminate film to the first side of the compressible thermal insulation layer, and the second high-temperature laminate film includes a second heat spreading layer disposed on the first side of the second integrity layer and a second adhesive layer disposed on a second, opposite side of the second integrity layer, the second adhesive layer adhering the second high-temperature laminate film to the second side of the compressible thermal insulation layer.

[0009] The above-described and other features are illustrated by the following drawings, detailed description, examples, and claims.

[0010] The following drawings are exemplary embodiments and are provided to illustrate the present disclosure. The drawings, which illustrate examples, are not intended to limit devices made in accordance with the present disclosure to the materials, conditions, or process parameters described therein. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is an illustration of an assembly for a prior art battery including electrochemical cells and cooling fins. [Figure 2] FIG. 1 is an illustration of one embodiment of an enclosed electrochemical cell. [Figure 3] FIG. 1 is an illustration of one embodiment of a battery assembly including an encased electrochemical cell. [Figure 4] FIG. 2 is a schematic diagram of one embodiment of a cooling fin including coolant channels. [Figure 5] FIG. 1 is an illustration of one embodiment of a battery assembly including an encased electrochemical cell. [Figure 6] FIG. 1 is an illustration of one embodiment of a thermal management multilayer sheet. [Figure 7] FIG. 1 is an illustration of one embodiment of a thermal management multilayer sheet. [Figure 8] FIG. 1 is an illustration of one embodiment of a thermal management multilayer sheet positioned between two electrochemical cells. [Figure 9] FIG. 1 is an illustration of one embodiment of a thermal management multilayer sheet positioned between two electrochemical cells. [Figure 10] FIG. 1 is an illustration of one embodiment of a thermal management multilayer sheet positioned in a cell array. [Figure 11] FIG. 1 is an illustration of an embodiment of a pouch cell battery. [Figure 12] FIG. 1 is an illustration of one embodiment of an assembly for a battery including a thermal management multilayer sheet. [Figure 13] FIG. 1 is a schematic diagram of a flame test apparatus. [Figure 14] 1 is a graph of temperature (° C.) versus time (minutes (min)) showing the results of a flame test. [Figure 15] FIG. 1 is a schematic diagram of a hot plate test apparatus. [Figure 16] 1 is a graph of temperature (° C.) versus time (minutes) showing the results of a hot plate test. [Figure 17] 1 is a graph of temperature (° C.) versus time (minutes) showing the results of a hot plate test. DETAILED DESCRIPTION OF THE INVENTION

[0012] Preventing thermal runaway in batteries containing multiple cells is a challenging problem because cells adjacent to a cell experiencing thermal runaway can absorb enough energy from the event to rise above their design operating temperature, triggering adjacent cells to also enter thermal runaway. This propagation of an initiating thermal runaway event can result in a chain reaction in which the storage device enters a cascading series of thermal runaway events as cells transfer heat to adjacent cells.

[0013] One approach to preventing such cascading thermal runaway events is to place cooling fins between, and preferably in contact with, adjacent cells or groups of cells for thermal management during cell operation. In battery designs, the cooling fins can transfer energy from the cells to a cooling plate that runs perpendicular to the cells and the cooling fins. However, prior art cooling fins, typically made of aluminum, also have high Z-direction thermal conductivity and can transfer heat from a cell, such as a pouch cell, to an adjacent cell. This heat transfer from a cell 100 to an adjacent cell 101 through a prior art aluminum cooling fin 200 assembled with a cooling plate 300 is shown in FIG. 1. The arrows indicate heat transfer in the Z direction from the cell 100 to the adjacent cell 101.

[0014] To prevent cascading thermal runaway events, thermal management multilayer sheets can be used instead of or in addition to cooling fins to reduce thermal conductivity in the Z direction, thereby reducing heat transfer from one cell to an adjacent cell. The thermal barrier provided by the thermal management multilayer sheets can also be used at various locations in the battery to prevent thermal runaway. In this way, the use of thermal management multilayer sheets can reduce thermal conductivity in any one or more directions. Thermal management multilayer sheets can further improve the fire resistance of the battery.

[0015] Thus, described herein are battery assemblies and batteries including electrochemical cells or electrochemical cell arrays that include a thermal management multilayer sheet, where the thermal management multilayer sheet is disposed directly on the surface of the electrochemical cell (i.e., contacts at least a portion of at least one surface). As used herein, an electrochemical cell (or "cell") is the basic unit of a battery that includes an anode, a cathode, and an electrolyte. A "cell array" refers to an assembly of two or more electrochemical cells, e.g., 2, 5, 20, 50, or more. A cell or cell array together with the thermal management multilayer sheet and optional other battery components, such as a separator, current collector, and housing, such as a flexible pouch, is referred to herein as a "battery assembly." Battery assemblies and batteries can include a single electrochemical cell, a single cell array, or multiple cell arrays.

[0016] A variety of electrochemical cell types can be used, including pouch cells, prismatic cells, or cylindrical cells. A single cell or an array of cells can be in a flexible housing, such as a pouch cell. In one aspect, the cells are lithium-ion cells, such as lithium iron phosphate, lithium cobalt oxide, or other lithium metal oxide cells. Other types of cells that can be used include nickel metal hydride, nickel cadmium, nickel zinc, or silver zinc.

[0017] In one embodiment, a battery assembly includes a thermal management multilayer sheet disposed on the surface of an electrochemical cell or cell array. As shown in FIG. 2, the thermal management multilayer sheet 400 can be disposed on at least two surfaces of the cell 102 to provide an encapsulated cell 500. The thermal management multilayer sheet can include three or more layers, as described in detail below. As shown in FIG. 2, the thermal management multilayer sheet 400 is directly on, i.e., in direct contact with, at least two, preferably two, surfaces of the cell 102, with no intervening layers. As further shown in FIG. 2, the thermal management multilayer sheet 400 completely covers, i.e., is in complete contact with, at least two, preferably two, surfaces of the cell 102. Alternatively, the thermal management multilayer sheet 400 can be in partial contact with one or more surfaces of the battery. Thus, the term "encapsulated" is used herein for convenience and does not require complete contact between all surfaces of the cell 102. Additionally, it will be understood that the thermal management multilayer sheet 400 can be in any configuration suitable for the battery configuration. Thus, the term "sheet" encompasses flat layers, as shown, as well as layers that have a profile or are formed, for example, by thermoforming. By providing an encased cell with a thermal management multilayer sheet, thermal conductivity in any one or more directions can be reduced. In one embodiment, the thermal management multilayer sheet reduces thermal conductivity in the Z direction, thus reducing heat transfer from one cell to an adjacent cell.

[0018] 3 shows one embodiment of a battery assembly 1000 including an encased cell 500. The encased cell 500 is positioned within the battery such that a first side 400a of the thermal management multilayer sheet 400 opposite the cell 102 is in thermal contact with the cooling fin 200 and a second side 400b of the thermal management multilayer sheet 400 opposite the cell 102 is in thermal contact with the cooling plate 300.

[0019] As shown in Figure 3, the cooling fins 200 and the wrapped cells 500 are positioned within the battery in a Y direction or perpendicular to the Z direction shown in Figure 1. The cooling fins 200 can be positioned so that the broad surface of the cooling fins 200 faces the wrapped surface of the wrapped cells 500. Heat transferred from the wrapped cells 500 to the cooling fins 200 can be conducted directly to the cooling plate 300 via the lower end of the cooling fins 200.

[0020] Exemplary materials for the cooling plate 300 include aluminum, copper, or alloys thereof. The cooling fins can have an average thickness of 0.0005 inches (12.7 μm) to 0.0200 inches (508 μm), preferably 0.001 inches (25.4 μm) to 0.005 inches (127 μm), and can comprise, for example, aluminum or an aluminum alloy. In one embodiment, the cooling fins can include multiple channels, thereby allowing coolant to flow through the cooling channels. For example, grooves can be stamped into first and, optionally, second foil sheets or plates, which are then joined, for example, by a nickel brazing process, to provide the cooling channels. Figure 4 is a schematic diagram of an exemplary cooling fin including coolant channels.

[0021] A battery assembly can include one or more cells and one or more cooling fins. As shown in FIG. 5 , one embodiment of the battery assembly 1001 includes a cell array, i.e., at least two encased cells. The battery assembly 1001 further includes a pressure pad 600, also referred to as a compression pad or battery pad when in the battery, and referred to herein as a "pressure pad" for convenience in all embodiments. The pressure pad 600 is disposed between the two encased cells. The pad can be disposed between adjacent cells or between cell arrays, as shown in FIG. 5 , to accommodate changes in compression, particularly during cell expansion. The pad can ensure that a substantially constant pressure is maintained on the cells.

[0022] Cooling fins 200 are positioned on opposite sides of the encased cells. A cooling plate 300 is in thermal communication with the cooling fins 200. Additional cooling fins may be present. As noted above, the cells of the cell array may be prismatic cells, pouch cells, cylindrical cells, etc., and are preferably pouch cells. In one embodiment, the cells are lithium-ion cells. In another embodiment, the cells are lithium-ion pouch cells.

[0023] One embodiment of a thermal management multilayer sheet is shown in Figure 6, where the thermal management multilayer sheet 401 includes a first heat spreading layer 61 disposed on a first side 62a of a thermal insulation layer 62. A second heat spreading layer 63 is disposed on a second side 62b of the thermal insulation layer 62. The use of two heat spreading layers can significantly improve the thermal management properties of the multilayer sheet.

[0024] The first and second heat spreading layers 61, 63 each independently comprise a material having a high thermal conductivity (Tc), such as greater than 10 watts per meter-Kelvin (W / m*K), preferably greater than 50 W / m*K, or more preferably greater than 100 W / m*K, each measured at 23° C. For example, the material may have a thermal conductivity of 10 to 6,000 W / m*K at 23° C., or 50 to 6,000 W / m*K at 23° C., or 100 to 6,000 W / m*K, or 100 to 1,000 W / m*K, or 100 to 500 W / m*K, each measured at 23° C. Such materials include metals such as copper, aluminum, silver, or alloys of copper, aluminum, or silver; ceramics such as boron nitride, aluminum nitride, silicon carbide, or beryllium oxide; or carbonaceous materials such as carbon fiber, carbon nanotubes, graphene, or graphite. For example, the heat spreading layer can be a tape or sheet comprising carbon fiber or carbon nanotubes, such as that available from Huntsman under the tradename MIRALON. In another aspect, the heat spreading layer is a metal or metal alloy foil, preferably aluminum or an aluminum alloy. In one aspect, the first and second heat spreading layers are each independently a foil, a woven or nonwoven fiber mat, or a polymer foam.

[0025] The thickness of the first and second heat spreading layers may depend on the materials used, the degree of thermal conductivity desired, cost, desired thickness, or weight of the battery, or similar considerations. For example, the heat spreading layer may have a thickness of 5 to 1,000 micrometers (μm), such as 0.0005 to 0.039 inches (12.7 to 991 μm), 0.001 to 0.005 inches (25.4 to 127 μm), or 0.002 to 0.039 inches (51 to 991 μm). The metal foils may each independently have a thickness of 0.0005 to 0.020 inches (12.7 to 508 μm), or 0.001 to 0.005 inches (25.4 to 127 μm).

[0026] The thermal insulation layer 62 is selected to retard thermal runaway. To retard thermal runaway, the thermal insulation layer 62 may have one or more of the following: a low thermal conductivity, such as 0.01 to 1.0 watts per meter-Kelvin (W / m*K), preferably 0.01 to 0.09 W / m*K, each measured at 23°C; a high latent heat of fusion, such as 70 to 350 Joules per gram (J / g); or both. The thermal insulation layer is preferably porous, which can improve its thermal insulation properties. The porosity can vary widely, such as 2 to 98% of the total volume of the layer, or 2 to 50% of the total volume of the layer, or 5 to 50% of the total volume of the layer, or 50 to 95% of the total volume of the layer. The pores 62d of the thermal insulation layer 62 can be open, closed, or a combination thereof. The pores 62d can have a regular shape, an irregular shape, or a combination thereof.

[0027] The thermal insulation layer 62 generally comprises a non-metallic material, which, as used herein, means that the material does not comprise only a metal or metal alloy, such as only aluminum or an aluminum alloy. However, it is understood that some non-metallic materials can include metals or metal ions in addition to other components. For example, non-metallic materials include mica, a mineral composed of silica in which some of the silicon ions may be replaced with aluminum ions. Exemplary materials used in thermal insulation layers include mica, vermiculite, zeolite, aerogel, polymer foam, polymer fiber, cork, or fiberglass. Combinations of different materials can be used.

[0028] In one embodiment, the use of polymer foams, particularly elastomeric polymer foams, in thermal management multilayer sheets can provide dramatic improvements in reduced thermal conductivity in any one or more directions. In one embodiment, such improvements can be provided by a particularly low thermal conductivity, such as, for example, 0.01 to 0.09 W / m*K measured at 23°C; a high latent heat of fusion, such as 70 to 350 Joules per gram (J / g); or both, as described herein. In one embodiment, improvements in reduced thermal conductivity can also be provided by pores in the polymer foam, which can enhance thermal insulation, as described herein.

[0029] When mica, vermiculite, zeolite, or other particulate material is used, the layer can include a composition including the particulate material and a binder. The binder is selected to maintain the layer's low thermal conductivity, high latent heat of fusion, or both. The binder can improve the strength of the particulate layer. Exemplary binders include epoxy, phenolic resin, polyamide, polyimide, polyester such as poly(butylene terephthalate), polyethylene, polypropylene, polystyrene, polycarbonate, polysulfone, polyurethane, silicone, and the like. Epoxy resin, silicone resin, phenolic resin, or other thermosetting resin is preferred for binding or improving the strength of the particulate layer. The amount of binder is selected to achieve optimal thermal conductivity and mechanical properties (e.g., high strength). For example, the composition can contain 20-90 weight percent (wt%) particulate filler and 10-80 wt% binder, or 20-80 wt% particulate filler and 20-80 wt% binder, each based on the total weight of the composition and totaling 100 wt%.

[0030] Aerogels are open-celled solid matrices containing an interconnected nanostructured network with a porosity of greater than 50% by volume (vol%), more preferably greater than 90% by volume. Aerogels can be derived from gels by replacing the liquid component in the gel with a gas or by drying a wet gel, such as by supercritical drying. Exemplary aerogels include polymeric aerogels, including poly(vinyl alcohol), urethane, polyimide, or polyacrylamide aerogels; polysaccharide aerogels, including chitin and chitosan aerogels; or inorganic ceramic aerogels, such as aluminum oxide or silica aerogels.

[0031] The polymer fibers or foams can comprise one or more of a wide variety of thermoplastics, blends of thermoplastics, or thermosets. Examples of thermoplastics that can be used include polyacetal, polyacrylic, polyamides such as nylon 6, nylon 6,6, nylon 6,10, nylon 6,12, nylon 11, or nylon 12, polyamideimide, polyarylate, polycarbonate, polystyrene, polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN), polyetherketone, polyetheretherketone, polyetherketoneketone, polyetherimide, polyolefins such as polypropylene, polyethylene, or copolymers of polyethylene or polypropylene, polyphenylene sulfide, polystyrene, polysulfones such as polyarylsulfone and polyethersulfone, polyurethanes, polyvinyl chloride, polychlorotrifluoroethylene, polyvinylidene fluoride (PVDF), polyvinyl fluoride, polytetrafluoroethylene, perf Fluorinated polymers such as fluoromethyl vinyl ether, fluorinated polyethylene-propylene (FEP), or tetrafluoroethylene-vinylidene fluoride-hexafluoropropylene (HFP), ethylene propylene rubber (EPR), ethylene propylene diene monomer rubber (EPDM), styrene-acrylonitrile (SAN), styrene-maleic anhydride (SMA), acrylonitrile-butadiene-styrene (ABS), natural rubber, nitrile rubber, butyl rubber, cyclic olefin copolymers, polydicyclopentadiene rubber, styrene-ethylene / propylene-styrene block copolymer (SEPS), styrene-butadiene block copolymer (SB), styrene-butadiene-styrene copolymer (SBS), styrene-ethylene / butylene-styrene block copolymer (SEBS), polybutadiene, isoprene, polybutadiene-isoprene copolymers, and the like, or combinations thereof.

[0032] Examples of blends of thermoplastic polymers that can be used in the polymer fibers or foams include ABS / nylon, polycarbonate / ABS, ABS / polyvinyl chloride, polyphenylene ether / polystyrene, polyphenylene ether / nylon, polysulfone / ABS, polycarbonate / thermoplastic urethane, polycarbonate / PET, polycarbonate / PBT, thermoplastic elastomer alloy, PET / PBT, SMA / ABS, polyetheretherketone / polyethersulfone, styrene-butadiene rubber, polyethylene / nylon, polyethylene / polyacetal, and the like, or combinations thereof.

[0033] Examples of thermosetting resins that can be used for the polymeric fibers or foams include polyurethanes, epoxies, phenolics, polyesters, polyamides, silicones, etc., or combinations thereof. Blends of thermosetting resins can be used, as well as blends of thermoplastic and thermosetting resins.

[0034] Preferred polymer fibers or foams that can be used in the thermal insulation layer include epoxy, polyamide, polyimide, polyester such as PBT, polyethylene, polypropylene, polystyrene, polycarbonate, polysulfone, polyurethane, silicone, vinyl ester, etc., or combinations thereof. In one embodiment, the polymer fibers include a heat-resistant polymer, such as a polymer having a Tg of 180°C or higher, for example, polyetherimide, polysulfone, polyphthalamide, polyphenylene sulfide, polyarylate, polyetheretherketone, etc., or combinations thereof. The polymer fibers can be in the form of a woven or nonwoven mat or tape. Polyurethane or silicone foams, particularly compressible polyurethane or silicone foams, are preferred and are described in more detail below. The polymer foam or fiber can include other additives known in the art, such as processing aids, flame retardants, fillers, antioxidants, antiozonants, ultraviolet (UV) or heat stabilizers, or combinations thereof. The filler can be selected to provide additional thermal insulation, heat absorption, or heat deflection properties. Exemplary fillers include silica, talc, calcium carbonate, clay, mica, ceramics such as vermiculite, or combinations thereof.

[0035] Cork materials that can be used for the thermal insulation layer include both natural and synthetic cork.

[0036] Exemplary fiberglass layers include A-glass, C-glass, D-glass, or combinations thereof. D-glass or E-glass is preferred. The fiberglass layer can be disposed in a polymer matrix or coated with a polymer. Epoxy, polyamide, polyimide, polyester such as poly(butylene terephthalate), polyethylene, polypropylene, polystyrene, polycarbonate, polysulfone, polyurethane, silicone, vinyl ester, and the like can be used. Preferred binders include epoxies, polyesters, and vinyl esters.

[0037] The thickness of the thermal insulation layer 62 can depend on the material used, the degree of thermal conductivity desired, cost, the desired thickness or weight of the battery, or similar considerations. For example, the thermal insulation layer 62 can have a thickness of 50 to 15,000 μm, e.g., 50 to 5,000, or 50 to 4,000 μm, or 0.002 to 0.118 inches (51 to 2,997 μm), preferably 0.006 to 0.020 inches (152 to 508 μm). In one embodiment, the thermal insulation layer can comprise mica, zeolite, polymer fiber, or fiberglass and can have a thickness of 50 to 5,000 μm. In another embodiment, the thermal insulation layer can comprise a polymer foam and can have a thickness of 250 to 10,000 μm, or 500 to 10,000 μm.

[0038] The first, second, or both thermal spreading and thermal insulating layers can be disposed directly on one another, or can be disposed on one another and adhered using one or more layers of adhesive. When adhesive layers are used, the adhesive layers can have a thickness of 0.00025 to 0.010 inches (6 to 254 μm), or 0.0005 to 0.003 inches (12.7 to 76 μm). A wide variety of adhesives are known in the art and can be used. For example, the adhesive layers can each independently comprise a polyester adhesive, a polyvinyl fluoride adhesive, an acrylic or methacrylic adhesive, or a silicone adhesive. In one embodiment, the adhesive is a silicone adhesive. Solvent-cast, hot-melt, and two-part adhesives can be used. In one embodiment, each adhesive layer can independently comprise an inorganic filler, which can be thermally spreading or thermally insulating.

[0039] Optionally, each adhesive layer can contain a filler that can independently be thermally diffusive (thermally conductive) or thermally insulating. Exemplary fillers include aerogel fillers, glass microballoons, gas-filled hollow polymer microspheres, boron nitride, aluminum nitride, mica, talc, carbon nanotubes, graphite, or combinations thereof. Additives can be surface-coated to provide desired properties; for example, fillers can be treated with silanes to improve dispersion or adhesion. For example, each adhesive layer can contain a high-aspect-ratio, platy filler, such as mica or talc. In one embodiment, no filler is present.

[0040] If the thermal insulation layer is not compressible or does not have reliable or sufficient compression-set values, it may be advantageous to use a pressure pad in combination with a thermal management multilayer, as shown in Figure 5. Of course, the pressure pad can be located elsewhere within the battery. In one embodiment, the pressure pad can have a thickness of 0.010 to 0.500 inches (254 to 12,700 μm) and can comprise a compressible material with reliable and consistent compression-set resistance (c-set) and stress relaxation performance over a wide temperature range. Exemplary materials of this type include polyurethane or silicone foams (such as PORON® polyurethane foam or BISCO® silicone foam, available from Rogers Corporation). Other compressible materials that can be used as pressure pads are described herein.

[0041] 7 shows a thermal management multilayer sheet 402 including a compressible thermal insulation layer 83. The multilayer sheet 402 further includes first and second high temperature laminates 81, 82. The first and second high temperature laminates 81, 82 are each disposed on a first side 83a and an opposite second side 83b, respectively, of the compressible thermal insulation layer 83. As used herein, "compressible" refers to the elastomeric property of a material being compressed under pressure and returning to its original state when the pressure is released.

[0042] The compressible thermal insulation layer can be selected to have properties that provide pressure management for the battery and allow it to replace or supplement pads as described above. In particular, the compressible thermal insulation layer is selected to provide one or more of reliable and consistent c-set resistance and stress relaxation performance over a wide range of temperatures, e.g., from -15 to 120°C. The compressible thermal insulation layer can have a compression set of less than 10%, preferably less than 5%, at 158°F (70°C) as measured according to ASTM D 3574-95 Test D. In some embodiments, the compressible thermal insulation layer can have a force retention of greater than 50%, as measured at 70°F (21°C) for 168 hours according to ISO 3384. The compressible thermal insulation layer can have a thickness effective to provide the desired pressure management. For example, the compressible thermal insulation layer can have an uncompressed thickness of 250 to 15,000 μm, or 0.020 to 0.500 inches (508 to 12,700 μm), or 0.040 to 0.157 inches (1,016 to 3,988 μm).

[0043] In one embodiment, thermal insulation layer 62 (FIG. 5) or compressible thermal insulation layer 83 (FIG. 7) is a compressible material such as an elastomer or rubber as mentioned above, particularly polyvinyl acetate (EVA), thermoplastic elastomer (TPE), EPR, or EPDM; or a polymer foam.

[0044] In one embodiment, the compressible thermal insulation layer is a compressible polymer foam. As used herein, "foam" means a material having a porous (i.e., cellular) structure. An exemplary compressible foam has a compressibility of 65 pounds per cubic foot (pcf) (1,041 kilograms per cubic meter (kg / m)). 3 )) lower density, preferably 55 pcf (881 kg / m 3 ) or less, or preferably 25 pcf (400 kg / m 3 The compressible polymer foam may have a void volume content of at least 5 to 99%, preferably 30% or greater, based on the total volume of the foam.

[0045] The compressible polymer foam may be any of the polymeric materials described above. As described above in connection with the polymeric fibers and foams, optional additives may be present in the composition for producing the compressible polymeric foam. In one embodiment, the compressible polymeric foam has a compressibility of 5 to 30 pounds per cubic foot (lb / ft), as measured according to ASTM D 3574-95 Test C. 3 )(80~481kg / m 3 ) density, 0.5~100lb / in 2 (351.5 to 70,307 kilograms per square meter (kg / m 2 )) and a compression set at 158°F (70°C) of less than 10%, preferably less than 5%, measured according to ASTM D 3574-95 Test D. Preferably, the compressible polymer foam is a polyurethane or silicone foam having the aforementioned properties.

[0046] In one embodiment, the compressible polymer foam has an average cell size of 50 to 250 μm; and a compressibility of 5 to 50 lb / ft, as can be measured, for example, according to ASTM D 3574-95. 3 (80-800.9 kg / m 3 ), preferably 6 to 25 lb / ft 3 (96-400kg / m 3The compressible polyurethane foam may be an open-cell, low-resilience polyurethane foam having a density of 1000 psi (1000 psi), a compression set at 158°F (70°C) of less than 10% as measured according to ASTM D 3574-95 Test D, and a force deflection between 1 and 250 pounds per square inch (psi) (7 and 1724 kilopascals (kPa)). Compressible polyurethane foams can be produced from compositions known in the art. Suitable compressible polyurethane foams are sold by Rogers Corporation, Woodstock, Conn., under the name PORON® 4700, e.g., PORON® EVExtend 4701-43RL. These compressible polyurethane foams can be formulated to provide a range of properties, including compression set resistance. Foams with excellent compression set resistance provide cushioning and maintain their original shape and thickness under load for extended periods of time.

[0047] In another embodiment, the compressible polymer foam is a silicone foam containing polysiloxane. In one embodiment, the silicone foam is produced as a result of the reaction of water with hydride groups in the polysiloxane polymer precursor composition and the resulting liberation of hydrogen gas. This reaction is generally catalyzed by a noble metal, preferably a platinum catalyst. The catalyst can be deposited on an inert support such as silica gel, alumina, or carbon black. Various platinum catalyst inhibitors can also be used to control the kinetics of the spraying and curing reactions to control the porosity and density of the silicone foam. Examples of such inhibitors include polymethylvinylsiloxane cyclic compounds and acetylenic alcohols. These inhibitors must not interfere with foaming and curing in such a way as to destroy the foam.

[0048] In one embodiment, the polysiloxane polymer has a viscosity of 100 to 1,000,000 poises at 25°C and has chain substituents such as hydride, methyl, ethyl, propyl, vinyl, phenyl, and trifluoropropyl. The end groups on the polysiloxane polymer can be hydride, hydroxyl, vinyl, vinyldiorganosiloxy, alkoxy, acyloxy, allyl, oxime, aminoxy, isopropenoxy, epoxy, mercapto, or other known reactive end groups. Silicone foams can also be produced using several polysiloxane polymers with different molecular weights (e.g., bimodal or trimodal molecular weight distributions), as long as the viscosity of the combination is within the specified range. It is also possible to use several polysiloxane base polymers with different functional or reactive groups to produce the desired foam. In one embodiment, the polysiloxane polymer contains 0.2 moles of hydride (Si-H) groups per mole of water.

[0049] Methods for producing compressible polymer foams are generally known. Foams can be mechanically foamed, physically or chemically blown, or both. Polyurethane foams can be made by casting a mechanically foamed composition. In particular, reactive polyurethane precursors can be mixed, mechanically foamed, and then cast to form a layer and cured. In the production of silicone foams, the reactive components of the precursor composition are stored in two packages: one containing a platinum catalyst and the other a polysiloxane polymer containing hydride groups, which prevents premature reaction. In another production method, the polysiloxane polymer is introduced into an extruder along with conductive particles, water, an optional physical blowing agent, and other desired additives. The platinum catalyst is then metered into the extruder to initiate the foaming and curing reaction. The use of a physical blowing agent, such as liquid carbon dioxide or supercritical carbon dioxide, in conjunction with a chemical blowing agent, such as water, can result in foams with lower densities. In yet another method, the liquid silicone components are metered, mixed, and dispensed into a device such as a mold or continuous coating line. Foaming then occurs either in the mold or on a continuous coating line.

[0050] The compressible thermal insulation layer can include a reinforcing material to enhance its strength. The reinforcing material for the thermal insulation layer can be fibrous, e.g., continuous fiber in the form of a woven or nonwoven fiber mat, which can have a thickness of 20 to 600 μm, or 0.001 to 0.020 inches (25.4 to 508 μm), preferably 0.001 to 0.005 inches (25.4 to 127 μm). The reinforcing material for the thermal insulation layer can include a high-temperature resistant woven or nonwoven polymer fiber mat, such as polyetherimide, polysulfone, polyphthalamide, polyphenylene sulfide, polyarylate, polyetheretherketone, or the like; or a woven or nonwoven glass fiber mat, such as fiberglass, as described above. In one embodiment, the reinforcing material for the thermal insulation layer includes plain weave 1080E-glass.

[0051] Referring again to FIG. 7 , the first high-temperature laminate 81 includes a first heat spreading layer 61 disposed on a first side 84a of a first integrity layer 84. A second side 84b of the first integrity layer 84 is disposed on a first adhesive layer 85. The first adhesive layer 85 adheres the first integrity layer 84 to a first side 83a of a compressible thermal insulation layer 83. The second high-temperature laminate film 82 includes a second heat spreading layer 63 disposed on a first side 86a of a second integrity layer 86. A second side 86b of the second integrity layer 86 is disposed on a second adhesive layer 87, which adheres the second integrity layer 86 to the second side 83b of the compressible thermal insulation layer 83.

[0052] The first and second heat spreading layers 61, 63 may be the same or different and are as described herein.

[0053] The first and second integrity layers 84, 86 are reinforcing materials for reinforcing the strength of the thermal management multilayer. Each can independently comprise continuous fibers in the form of a woven or nonwoven fiber mat, which can have a thickness of, for example, 20 to 600 μm, or 0.001 to 0.020 inches (25.4 to 508 μm), preferably 0.001 to 0.005 inches (25.4 to 127 μm). The first and second integrity layers can comprise high-temperature resistant woven or nonwoven polymer mats, such as polyetherimide, polysulfone, polyphthalamide, polyphenylene sulfide, polyarylate, polyetheretherketone, and the like; or woven or nonwoven glass mats, such as fiberglass, as described above. In one embodiment, each of the first and second integrity layers comprises plain weave 1080E-glass.

[0054] The first and second adhesive layers can have any thickness suitable for providing effective adhesion, preferably also tailored so as not to waste adhesive material or significantly adversely affect the desired properties of the thermal management multilayer sheet. For example, the first and second adhesive layers can have thicknesses of 0.00025 to 0.010 inches (6.35 to 254 μm), or 0.0005 to 0.003 inches (12.7 to 76.2 μm). The first and second adhesive layers 85, 87 can be the same or different, as described herein. For example, the first and second adhesive layers can each independently comprise a polyester adhesive, a polyvinyl fluoride adhesive, an acrylic or methacrylic adhesive, or a silicone adhesive. In one embodiment, the adhesive is a silicone adhesive. Also, as described above, each adhesive layer can independently comprise an inorganic filler, which can be thermally diffusive or thermally insulating. For example, the adhesive can comprise a high aspect ratio platy filler, such as mica or talc. In one embodiment, no filler is present.

[0055] Thermal management multilayers and subcombinations thereof (e.g., high-temperature laminates) can be manufactured by methods known in the art, depending on the materials used for the heat-spreading layer, thermal insulation layer, and optional adhesive layer. Manufacturing can be accomplished, for example, by stacking the layers individually and laminating them with or without adhesive; by coating or casting the heat-spreading layer composition onto the thermal insulation layer; by immersing the thermal insulation layer in the heat-spreading layer-forming composition; or by coating or casting the heat-spreading layer-forming composition directly onto the heat-spreading layer or onto an adhesive layer disposed on the heat-spreading layer. Processes such as roll-over-roll, knife-over-roll, reverse roll, slot die, or gravure coating can be used. In one embodiment, when the thermal insulation layer comprises a polymer foam, the foam-forming composition can be cast onto a first heat-spreading layer, such as a metal foil, foamed, covered with a second foil layer to control the foam thickness, and then heated to cure the foam. An adhesive layer can be present on one or both of the foil layers. Alternatively or additionally, subcombinations such as thermal insulation layers or high-temperature laminates can be commercially available and then assembled with one or more additional layers to form a thermal management multilayer. One example of a commercially available high-temperature laminate is plasma tape, e.g., an aluminum foil / glass cloth laminate that further includes a high-temperature silicone adhesive disposed on the glass cloth. Such laminates are commercially available from DeWAL under the trade name DW Series Plasma Tape, such as DW407 Plasma Tape.

[0056] It will be understood that the embodiments shown in Figures 6 and 7 are exemplary only, and that various combinations and subcombinations can be used depending on the desired properties. For example, a thermal management multi-layer sheet such as that shown in Figure 7 can include only a single integrity layer. Additional heat spreading, adhesive, or thermal insulation layers can be present. For example, a thermal management multi-layer sheet such as that shown in Figure 6 can include an additional thermal insulation layer on one side of the heat spreading layer, with or without an additional adhesive layer therebetween.

[0057] Yet another layer or component that can be present in the thermal management multilayer sheet includes a phase change material. Specifically, the thermal insulation layer can include a phase change material. Alternatively or additionally, a layer including a phase change material can be disposed on the thermal insulation layer. A phase change material is a substance that has a high heat of fusion and can absorb and release large amounts of latent heat during phase changes, such as melting and solidification, respectively. During a phase change, the temperature of the phase change material remains approximately constant. The phase change material inhibits or stops the flow of thermal energy through the material during the period when the phase change material is absorbing or releasing heat, typically during the material's phase change. In some instances, the phase change material can inhibit heat transfer during the period when the phase change material is absorbing or releasing heat, typically when the phase change material undergoes a transition between two states. This effect is typically transient and occurs until the latent heat of the phase change material is absorbed or released during the heating or cooling process. Heat can be stored or removed from the phase change material, which can typically be effectively recharged by a heat or cold source.

[0058] Suitable phase change materials are described, for example, in International Publication No. WO 2020 / 227201. As described therein, the phase change material can be encapsulated or unencapsulated, or a combination thereof can be used. The phase change material can be used in a composition further comprising a polymer, such as those described above. The polymer can include one or a combination of those described above, such as polyvinyl chloride, polystyrene, polyethersulfone, ABS, SAN, PEN, PBT, PET, PVDF, perfluoromethyl vinyl ether, polypropylene, polyethylene, copolymers of polyethylene or polypropylene, polytetrafluoroethylene (PTFE), FEP, vinylidene fluoride, HFP, EPR, EPDM, natural rubber, nitrile rubber, butyl rubber, cyclic olefin copolymers, polydicyclopentadiene rubber, thermoplastic polyurethane, SEPS, poly(styrene-butadiene-styrene) (SBS), SEBS, polybutadiene, isoprene, polybutadiene-isoprene copolymers, or combinations thereof. The amount of phase change material can be 20 to 98 wt%, or 40 to 97 wt%, or 50 to 96 wt%, or 50 to 95 wt%, or 40 to 95 wt%, or 50 to 90 wt%, or 60 to 85 wt%, or 75 to 85 wt%, based on the total weight of the phase change composition.

[0059] In one embodiment, the thermal insulation layer can include an intumescent composition, or the thermal management multilayer sheet can include a layer including the intumescent composition. This layer can be disposed on the thermal diffusion layer opposite the thermal insulation layer, or it can be disposed between the thermal diffusion layer and the thermal insulation layer. Without being bound by theory, it is believed that the intumescent material can reduce the spread of flames using two energy absorption mechanisms, including char formation and subsequent char expansion. For example, when the temperature reaches a value of, for example, 200-280°C, acidic species (e.g., polyphosphoric acid) can react with a carbon source (e.g., pentaerythritol) to form char. When the temperature increases to, for example, 280-350°C, the blowing agent decomposes to produce gaseous products, expanding the char. Intumescent materials are known, for example, as described in International Publication No. 2020 / 251825. The intumescent material can include an acid source, a blowing agent, and a carbon source. Each of these components can be present in a separate layer or as a blend, preferably an intimate blend. For example, the intumescent material can include an acid source of polyphosphoric acid such as tris(2,3-dibromopropyl)phosphate, tris(2-chloroethyl)phosphate, tris(2,3-dichloropropyl)phosphate, tris(1-chloro-3-bromoisopropyl)phosphate, bis(1-chloro-3-bromoisopropyl)-1-chloro-3-bromoisopropylphosphate, polyaminotriazine phosphate, melamine phosphate, guanylurea phosphate, or a combination thereof; a carbon source such as dextrin, phenol-formaldehyde resin, pentaerythritol, clay, polymer, or a combination thereof; and a blowing agent such as dicyandiamide, azodicarbonamide, melamine, guanidine, glycine, urea, a halogenated organic substance, or a combination thereof.

[0060] The thermal management multilayer sheet is disposed over at least a portion of an electrochemical cell, such as at least one electrochemical cell, to provide a battery cell assembly. For example, FIG. 8 illustrates one embodiment of the positioning of the thermal management multilayer sheet in a battery assembly 1002, and FIG. 9 illustrates one embodiment of the positioning of the thermal management multilayer sheet in a battery assembly 1003. The cells can be lithium-ion cells, particularly pouch cells. FIGS. 8 and 9 show that the thermal management multilayer sheet 403 can be positioned between a first cell 103 and a second cell 104. FIG. 8 illustrates that the thermal management multilayer sheet 403 can be approximately the same size as the height and width of the cells 103, 104. FIG. 9 illustrates that the thermal management multilayer sheet 403 can be smaller than each of the cells 103, 104. As shown in FIG. 5, the thermal management multilayer sheet can also extend beyond the edges of the electrochemical cells to cover at least a portion or all of the cell's surface.

[0061] FIG. 10 illustrates that a battery assembly 1004 can include two or more cells (e.g., 103, 104) with a thermal management multilayer sheet 403 positioned between each cell 103, 104 and each of the other cells. In one embodiment, two to ten fire-resistant thermal management multilayer sheets can be placed on the cells or within the cell array during the manufacture of the battery assembly 1004. For example, the two to ten thermal management multilayer sheets can be placed internally, e.g., facing the electrodes, or externally, e.g., facing the exterior of the battery. For example, the two to ten fire-resistant thermal management multilayer sheets can be placed or adhered to the cells and / or pouches of a pouch cell. Of course, there can be one or more than ten thermal management multilayer sheets, depending on the number of cells and cell array. FIG. 10 also illustrates a thermal management multilayer sheet 403a positioned externally of the battery assembly 1004, facing the exterior of the battery.

[0062] In one aspect, at least a portion of the exposed outer edge of the thermal management multilayer sheet may include a material that draws heat away from the body of the thermal management multilayer sheet 88. Exemplary materials for application to the exposed edges of the thermal management multilayer sheet include ceramics such as boron nitride or aluminum nitride, metals such as aluminum, high heat capacity wax, phase change materials, etc., or combinations thereof.

[0063] The cell assembly is used in a battery. The battery includes a housing that at least partially encloses one or more electrochemical cells or cell arrays. As shown in FIG. 11 , an exemplary battery 2000 can include a flexible housing, e.g., a pouch 51, that surrounds and seals an electrode assembly 52. ​​The housing for the pouch cell or battery of FIG. 11 is typically a laminate material including a metal foil layer. For example, a laminate pouch cell material can include a metal foil, such as aluminum foil, between two polymer layers. The metal foil is intended to function as a barrier to all permeation into and out of the battery cell, including the diffusion of water. Thus, the laminate completely surrounds and seals the electrochemical cell or cell array. A thermal management multilayer sheet is added to the housing, i.e., pouch 51.

[0064] The electrode assembly 52 can include an anode, a separator, a cathode, and an electrolyte. The battery 2000 also includes a negative current collector 53 connected to the anode and a positive current collector 54 connected to the cathode. The negative current collector 53 and the positive current collector 54 can be electrically connected to a control electronics system 55 that includes the battery's control electronics. The battery 2000 also includes a negative external lead 56 and a positive external lead 57 that allow for connection of the battery 2000 to a circuit or device.

[0065] The thermal management multilayer sheet can be placed on or directly over any configuration of cells or cell arrays within a battery. The thermal management multilayer sheet can be placed between individual cells or cell arrays within a battery. The thermal management multilayer sheet can be placed on the side of, a portion of, or a selected set of cells or cell arrays within a battery, e.g., on top of, between, under, adjacent to, or a combination thereof. The thermal management multilayer sheet can be placed or adhered, for example, to multiple pouch cells, pressure management pads, cooling plates, or other internal battery components with no exposed adhesive. The battery assembly pressure can hold the stacked components in place.

[0066] For example, as shown in Fig. 12, a battery 2001 can include a plurality of cells of a plurality of cell arrays 700 inside a housing 800. A thermal management multilayer sheet 403 can be disposed between two cell arrays 700. As further shown in Fig. 12, the thermal management multilayer sheet 403 can be disposed along a plurality of cells of the cell array between a side surface of the housing 800 and a side surface of the cell array 700. As further shown in Fig. 12, the thermal management multilayer sheet 403 can be disposed between an end of the housing 800 and an end of one or more cell arrays 700.

[0067] The following examples are provided to illustrate the present disclosure. The examples are merely illustrative and are not intended to limit devices made in accordance with the present disclosure to the materials, conditions, or process parameters described therein. [Example]

[0068] The materials listed in Table 1 were used in the examples.

[0069] [Table 1]

[0070] The samples were prepared in the laboratory by using a heavy roller to adhere plasma tape to opposite sides of polyurethane foam sheets, and then placed adjacent to a 12.7 millimeter (mm) thick pouch cell analog and subjected to the burn test or hot plate test.

[0071] Comparative Example Only polyurethane foam sheets were used.

[0072] Example 1 The thermal management multilayer sheet included Plasma Tape 1 on both sides of a polyurethane foam sheet.

[0073] Example 2 The thermal management multilayer sheet included Plasma Tape 2 on both sides of a polyurethane foam sheet.

[0074] Example 3 The thermal management multilayer sheet included plasma tape 3 on both sides of a polyurethane foam sheet.

[0075] Example 4 The thermal management multilayer sheet included Plasma Tape 1 on both sides of the silicone foam.

[0076] Figure 13 shows the combustion test apparatus 1300. A hole was drilled through the pouch cell analog and a thermocouple probe 131 was inserted. A propane torch 132 was used to generate a 100 mm flame on the side of the sample 404 opposite the pouch cell analog 133. The propane torch 132 was positioned 25 mm from the surface of the sample 404. Temperatures were recorded from the probe at 0.5, 1, 2, 3, 5, 7, and 10 minute intervals.

[0077] After 10 minutes of direct flame exposure from a propane torch, the Comparative Example reached a maximum temperature of 604°C, as shown in Figure 14. Example 1 provided improved flame resistance, as shown in Figure 14. Example 1 reached a maximum temperature of 222°C after 10 minutes of direct flame exposure, providing excellent flame resistance.

[0078] FIG. 15 shows a hot plate test apparatus 1500. The sample 405 is a pouch cell analog 153 (e.g., 0.025 mm polyamide, 4-5 grams per square meter (g / m 2 ) adhesive, 0.040mm aluminum foil, 2~3g / m 2 The pouch cell analog 153 is placed against a 12.7 mm thick mica plate (having a pouch cell film composite containing 0.040 mm of adhesive and 0.040 mm of polypropylene). A through hole is drilled in the pouch cell analog 153 on the side facing the sample 405, and a temperature sensor, such as a thermocouple probe 92, is inserted into the pouch cell analog 153. A 0.001 inch (25.4 μm) aluminum foil 154 is placed between the sample 405 and the hot plate 152 to protect the surface of the hot plate 152. The hot plate 152 is allowed to reach a temperature of 550°C. The pouch cell analog 153 and sample 405 are placed on the hot plate 152 with the sample 405 closest to the hot plate 152. The temperature is measured using a temperature sensor 151 at time intervals such as 0 minutes, 0.5 minutes, 1 minute, 2 minutes, 3 minutes, 5 minutes, 7 minutes, and 10 minutes.

[0079] As shown in Figure 16, Example 1 experienced a 100 second delay in reaching 150°C compared to the Comparative Example, with a maximum temperature of 239°C compared to 273°C for the Comparative Example. Examples 2 and 3 showed similar performance improvements over the Comparative Example. As shown in Figure 17, Example 4 experienced a 142 second delay in reaching 150°C compared to the Comparative Example, with a maximum temperature of 199°C.

[0080] Described below are non-limiting aspects of the present disclosure.

[0081] Aspect 1: A battery assembly including a thermal management multilayer sheet disposed on a surface of an electrochemical cell, the thermal management multilayer sheet including a thermal insulation layer, a first heat diffusion layer disposed on a first side of the thermal insulation layer, and a second heat diffusion layer disposed on a second side of the thermal insulation layer.

[0082] Embodiment 2: The battery assembly of embodiment 1, wherein the thermal management multilayer sheet is disposed directly on at least two surfaces of the electrochemical cell, and preferably the multilayer sheet is further disposed over at least two surfaces of the cell.

[0083] Embodiment 3: The battery assembly of any of the preceding embodiments, wherein the electrochemical cell comprises a prismatic cell, a pouch cell, or a cylindrical cell, preferably a pouch cell.

[0084] Aspect 4: The battery assembly of any of the preceding aspects, wherein the first and second heat spreading layers each independently have a thickness of 5 to 1,000 micrometers.

[0085] Aspect 5: The battery assembly of any of the preceding aspects, wherein the first and second heat spreading layers each independently comprise copper, aluminum, silver, a copper alloy, an aluminum alloy, a silver alloy, boron nitride, aluminum nitride, silicon carbide, beryllium oxide, carbon fiber, carbon nanotubes, graphene, graphite, or a combination thereof.

[0086] Aspect 6: The battery assembly of any of the preceding aspects, wherein the thermal insulation layer has a thickness of 50 to 15,000 micrometers, or 50 to 5,000 micrometers.

[0087] Aspect 7: The battery assembly of any of the preceding aspects, wherein the thermal insulation layer has a thermal conductivity of 0.01 to 1.0 W / m*K at 23°C, a heat of fusion of 70 to 350 J / g, or both; preferably, the thermal insulation layer has a thermal conductivity of 0.01 to 0.09 W / m*K at 23°C, a heat of fusion of 70 to 350 J / g, or both.

[0088] Aspect 8: The battery assembly of any of the preceding aspects, wherein the thermal insulation layer comprises mica, vermiculite, zeolite, aerogel, polymer foam, polymer fiber, cork, fiberglass, or a combination thereof, preferably wherein the thermal insulation layer comprises zeolite, aerogel, polymer foam, polymer fiber, cork, fiberglass, or a combination thereof.

[0089] Aspect 9: The battery assembly of any of the preceding aspects, wherein the thermal insulation layer is compressible and has a compression set of less than 10% at 158°F (70°C) as measured according to ASTM D 3574-95 Test D.

[0090] Embodiment 10: The battery assembly of embodiment 9, wherein the thermal insulation layer comprises a compressible elastomeric polymer, and preferably, the compressible elastomeric polymer comprises vinyl acetate, a thermoplastic elastomer, an ethylene-propylene rubber, an ethylene-propylene-diene monomer rubber, or a combination thereof.

[0091] Embodiment 11: The battery assembly of embodiment 9, wherein the thermal insulation layer comprises a compressible polymer foam, preferably a polyurethane foam or a silicone foam.

[0092] Aspect 12: The compressible polymer foam has a compressibility of 80 to 481 kg / m 3 Density, measured according to ASTM D 3574-95 Test C, 351.5 to 70,307 kg / m 2 and a compression set at 158°F (70°C) of less than 10%, preferably less than 5%, as measured according to ASTM D 3574-95 Test D.

[0093] Embodiment 13: The battery assembly of embodiment 11 or 12, wherein the compressible polymer foam is in the form of a layer having an uncompressed thickness of 250 to 15,000 micrometers.

[0094] Embodiment 14: The battery assembly of any one of the preceding embodiments, further comprising an adhesive layer disposed between the first heat spreading layer and the thermal insulation layer.

[0095] Embodiment 15: The battery assembly of embodiment 14, wherein the adhesive layer further comprises a particulate filler.

[0096] Embodiment 16: The battery assembly of any one of the preceding embodiments, further comprising an integrity layer comprising a heat-resistant reinforcing material disposed between the first heat spreading layer and the thermal insulation layer.

[0097] Embodiment 17: The battery assembly of embodiment 16, wherein the heat-resistant reinforcing material comprises a woven or nonwoven mat comprising a high-temperature resistant polymer or glass.

[0098] Embodiment 18: The battery assembly of embodiment 16 or 17, wherein the integrity layer has a thickness of 20 to 600 micrometers.

[0099] Aspect 19: The battery assembly of any one of the preceding aspects, wherein the thermal management multilayer sheet includes, in order, a first heat spreading layer, a first integrity layer, a first adhesive layer, a thermal insulation layer, a second adhesive layer, a second integrity layer, and a second heat spreading layer.

[0100] Embodiment 20: The battery assembly of any one of the preceding embodiments, wherein the assembly includes at least two electrochemical cells.

[0101] Embodiment 21: A battery comprising the battery assembly of any one of Embodiments 1 to 20 and a housing at least partially enclosing the battery assembly.

[0102] Aspect 22: A thermal management multilayer sheet comprising a first high-temperature laminate adhered to a first side of a compressible thermal insulation layer and a second high-temperature laminate adhered to a second, opposite side of the compressible thermal insulation layer, wherein the first high-temperature laminate film comprises a first heat spreading layer disposed on a first side of the first integrity layer and a first adhesive layer disposed on a second side opposite the first integrity layer, the first adhesive layer adhering the first high-temperature laminate film to the first side of the compressible thermal insulation layer, and the second high-temperature laminate film comprises a second heat spreading layer disposed on a first side of the second integrity layer and a second adhesive layer disposed on a second side opposite the second integrity layer, the second adhesive layer adhering the second high-temperature laminate film to the second side of the compressible thermal insulation layer.

[0103] Embodiment 23: An assembly for a battery, comprising the thermally insulating multilayer sheet of embodiment 22 disposed over an electrochemical cell.

[0104] Embodiment 24: The battery assembly of embodiment 23, wherein the assembly comprises at least two electrochemical cells.

[0105] Embodiment 25: A battery comprising the battery assembly of any one of embodiments 23 or 24 and a housing at least partially enclosing the battery assembly.

[0106] Aspect 26: A battery comprising: a thermal management multilayer sheet positioned adjacent to at least two surfaces of an electrochemical cell; cooling fins contacting a surface of the thermal management multilayer sheet opposite the electrochemical cell; and a cooling plate perpendicular to and in thermal contact with the cooling fins, wherein the thermal management multilayer sheet comprises a first heat spreading layer positioned on a first side of the thermal insulation layer and a second heat spreading layer positioned on a second side of the thermal insulation layer.

[0107] Embodiment 27: The battery of embodiment 26, wherein the thermal management multilayer sheet covers two surfaces of the electrochemical cell.

[0108] Embodiment 28: The battery of embodiment 26 or 27, wherein the electrochemical cell comprises a prismatic cell, a pouch cell, or a cylindrical cell, preferably a pouch cell.

[0109] Embodiment 29: The battery of any one of embodiments 26-28, wherein the first and second heat spreading layers each independently have a thickness between 0.0005 inches (12.7 micrometers) and 0.0200 inches (508 micrometers), preferably between 0.001 inches (25.4 micrometers) and 0.005 inches (127 micrometers).

[0110] Embodiment 30: The battery of any one of Embodiments 26 to 29, wherein the first and second heat spreading layers each independently comprise copper, aluminum, an alloy of copper or aluminum, boron nitride, aluminum nitride, a nonwoven carbon nanotube sheet or tape, a carbon nanotube film, or a graphite film, preferably aluminum or an aluminum alloy.

[0111] Embodiment 31: The battery of any one of embodiments 26-30, wherein the thermal insulation layer has a thickness of 0.002 inches (51 micrometers) to 0.039 inches (991 micrometers), preferably 0.006 inches (152 micrometers) to 0.020 inches (508 micrometers).

[0112] Embodiment 32: The battery of any one of Embodiments 26 to 31, wherein the thermal insulation layer has a thermal conductivity at 23° C. of 0.01 to 0.09 W / m*K, a heat of fusion of 70 to 350 J / g, or both.

[0113] Embodiment 33: The battery of any one of Embodiments 26-32, wherein the thermal insulation layer comprises aerogel, mica, foam such as polyurethane or silicone foam, cork, or fiberglass.

[0114] Embodiment 34: The battery of any one of Embodiments 26-33, wherein the thermal insulation layer further comprises a filler.

[0115] Embodiment 35: The battery of any one of embodiments 26 to 34, wherein the cooling fins include coolant channels.

[0116] Embodiment 36: The battery of any one of embodiments 26-35, further comprising a pressure pad, wherein the pressure pad comprises polyurethane foam or silicone foam.

[0117] The compositions, methods, and articles described herein can alternatively comprise, consist of, or consist essentially of any suitable material, step, or component disclosed herein. The compositions, methods, and articles may additionally or alternatively be formulated to be free or substantially free of any material (or species), step, or component that is not necessary to achieve the function or purpose of the compositions, methods, and articles.

[0118] The terms "a" and "an" do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. The term "or" means "and / or" unless the context clearly dictates otherwise. References throughout this specification to "one embodiment," "another embodiment," etc., mean that a particular element (e.g., a feature, structure, step, or characteristic) described in connection with that embodiment is included in at least one embodiment described herein and may or may not be present in other embodiments. Furthermore, it will be understood that the described elements can be combined in any suitable manner in the various embodiments.

[0119] When an element such as a layer, film (including a thermally insulating multilayer film), region, or substrate is referred to as being "on" another element, it can be adjacent to the other element, directly on the other element, or there can be intervening elements. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements. Furthermore, when an element such as a layer, film (including a thermally insulating multilayer film), region, or substrate is referred to as being "on" or "directly on" another element, all or a portion of the element can be adjacent to all or a portion of the other element.

[0120] Unless otherwise specified herein, all test standards are the most recent standards in effect as of the filing date of this application or, if priority is claimed, as of the filing date of the earliest priority application in which the test standard appears.

[0121] The endpoints of all ranges directed to the same component or property are inclusive, independently combinable, and include all intermediate points and ranges. As used herein, terms such as "first," "second," "primary," "secondary," and the like, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms "combination of" or "at least one of" mean that the list includes not only each element individually, but also combinations of two or more elements of the list, and combinations of at least one element of the list with similar elements not listed. The term "combination" also includes blends, mixtures, alloys, reaction products, and the like.

[0122] Unless otherwise defined, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0123] All cited patents, patent applications, and other references are incorporated herein by reference in their entirety, except that if a term in this application contradicts or conflicts with a term in an incorporated reference, the term from this application takes precedence over the conflicting term from the incorporated reference.

[0124] In the drawings, the width and thickness of layers and regions are exaggerated for clarity and convenience of description. Like reference numerals in the drawings denote like elements.

[0125] Exemplary embodiments are described herein with reference to cross-section illustrations that are schematic illustrations of idealized embodiments. As such, variations from the shapes of the illustrations are to be expected as a result, for example, of manufacturing techniques and / or tolerances. Thus, the embodiments described herein should not be construed as limited to the particular shapes of regions as illustrated herein, but are to include deviations in shapes that result, for example, from manufacturing. For example, a region illustrated or described as flat may typically have rough and / or non-linear features. Furthermore, sharp angles shown may be rounded. Thus, the regions illustrated in the figures are schematic in nature, and their shapes are not intended to illustrate the precise shapes of the regions, nor are they intended to limit the scope of the claims.

[0126] While particular embodiments have been described, presently unforeseen or unanticipated alternatives, modifications, variations, improvements, and substantial equivalents may occur to applicant or others skilled in the art. Accordingly, the appended claims are intended to embrace all such alternatives, modifications, variations, improvements, and substantial equivalents as filed and as they may be amended. [Explanation of symbols]

[0127] 51 pouches 52 Electrode Assembly 53 Negative current collector 54 Positive current collector 55 Control Electronic System 56 Negative external lead 57 Positive external lead 61 First heat diffusion layer 62 Thermal insulation layer 63 Second heat diffusion layer 81 First High Temperature Laminate 82 Second High Temperature Laminate 83 Compressible thermal insulation layer 84 First Integrity Layer 85 First adhesive layer 86 Second Layer of Integrity 87 Second adhesive layer 88 Thermal Management Materials that draw heat away from the body of the multilayer sheet 102, 103, 104 cells 131 Thermocouple Probe 132 Propane Torch 133, 153 Pouch Cell Analog 151 Temperature Sensor 152 Hot plate 154 Aluminum foil 200 Cooling fins 300 Cooling Plate 400, 401, 402, 403 Thermal management multilayer sheet Samples 404 and 405 500 wrapped cells 600 pressure pads 700 cell array 800 Housing 1000, 1001, 1002, 1003, 1004 Battery Assemblies 1300 Combustion Test Equipment 1500 Hot Plate Testing Apparatus 2000, 2001 batteries

Claims

1. Thermal management multilayer sheet disposed on the surface of an electrochemical cell A battery assembly comprising: The thermal management multilayer sheet comprises: a thermal insulation layer (62) comprising a compressible polymer foam; a first heat spreading layer (61) disposed on a first side of the thermal insulation layer; an integrity layer including a heat resistant reinforcing material disposed between the first heat spreading layer and the thermal insulation layer; a second heat spreading layer (63) disposed on a second side of the thermal insulation layer; 12. An assembly for a battery, comprising:

2. 10. The battery assembly of claim 1, wherein the first and second heat spreading layers each independently have a thickness of 5 to 1,000 micrometers.

3. 3. The battery assembly of claim 1, wherein the first and second heat spreading layers each independently comprise copper, aluminum, silver, a copper alloy, an aluminum alloy, a silver alloy, boron nitride, aluminum nitride, silicon carbide, beryllium oxide, carbon fiber, carbon nanotubes, graphene, graphite, or a combination thereof.

4. 4. The battery assembly according to claim 1, wherein the thermal insulation layer has a thickness of 50 to 15,000 micrometers.

5. 5. The battery assembly according to claim 1, wherein the thermal insulation layer has a thermal conductivity of 0.01 to 1.0 W / m*K at 23° C., a heat of fusion of 70 to 350 J / g, or both.

6. 6. The battery assembly of claim 1, wherein the thermal insulation layer has a compression set of less than 10% at 158°F (70°C) as measured according to ASTM D 3574-95 Test D.

7. 7. The battery assembly according to claim 1, wherein the thermal insulating layer comprises polyurethane foam or silicone foam.

8. The compressible polymer foam has a compressibility of 80 to 481 kg / m ３ Density, measured according to ASTM D 3574-95 Test C, from 351.5 to 70,307 kg / m ２ 8. The battery assembly of claim 1, having a 25% compressive force deflection of 0.01% or less and a compression set at 158°F (70°C) of less than 10% as measured according to ASTM D 3574-95 Test D.

9. 9. The battery assembly of claim 1, wherein the compressible polymer foam is in the form of a layer having an uncompressed thickness of 250 to 15,000 micrometers.

10. 10. The battery assembly according to claim 1, further comprising an adhesive layer disposed between the first heat spreading layer and the thermal insulation layer.

11. The battery assembly of claim 10 , wherein the adhesive layer further comprises a particulate filler.

12. 12. The battery assembly of claim 1, wherein the integrity layer has a thickness of 20 to 600 micrometers.

13. A thermal management multilayer sheet disposed on the surface of an electrochemical cell. A battery assembly comprising: The thermal management multilayer sheet comprises, in order: a first heat spreading layer (61) disposed on a first side of the thermal insulating layer (62); a first integrity layer; and a first adhesive layer; the thermal insulation layer (62) comprising a compressible polymer foam; a second adhesive layer; and a second integrity layer; and a second heat spreading layer (63) disposed on a second side of the thermal insulation layer (62); 12. An assembly for a battery, comprising:

14. A battery assembly as described in claim 13, wherein the first integrity layer includes a heat-resistant reinforcing material.

15. A battery assembly according to any one of claims 1 to 14; a housing at least partially enclosing the battery assembly; Including batteries.

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