Managing thermal propagation

Abstract

A thermal management apparatus includes a multilayered sheet that includes a thermally insulating core including a first surface and a second surface opposite the first surface; a first thermally conductive layer that is disposed to a first portion of the first surface of the thermally insulating core; and a second thermally conductive layer that is disposed to a first portion of the second opposite surface of the thermally insulating core. Each of the first surface and the second surface of the thermally insulating core includes a second portion exposed to an environment.

Description

24POLY0063-WO-ORD 1MANAGING THERMAL PROPAGATIONTECHNICAL FIELD

[0001] The present disclosure relates generally to the field of energy storage systems, and more particularly to battery packs used in high energy application, such as electric vehicles and motorbikes (e.g., EVs). Specifically, the disclosure pertains to a thermal management apparatus that manages (e.g., some, all, or substantially) the effects and propagation of heat from one battery cell to another adjacent cell during thermal runaway events.BACKGROUND

[0002] Lithium-ion batteries and other battery technologies have become integral to many applications, including EVs, portable electronics, large-scale energy storage systems, and electric motors. These batteries offer significant advantages in terms of energy capacity, efficiency, and power output. However, one of the major concerns associated with these battery technologies is thermal runaway.

[0003] Thermal runaway refers to a chain reaction within a battery cell, in which an initial temperature increase triggers further reactions that release more heat, causing a dangerous and escalating rise in temperature. This can result in the release of flammable gases, rupture of the cell, or even a fire or explosion. Thermal runaway can be initiated by various factors, including overcharging, internal short circuits, external heat, or mechanical damage to the battery. Once initiated, the heat generated by thermal runaway can spread to adjacent cells in a battery pack, leading to failure of the battery system.

[0004] In typical battery packs, especially those used in EVs and large energy storage systems, individual battery cells are densely packed together to maximize energy density. Unfortunately, this close packing increases the risk of thermal runaway propagation, where the heat from an affected cell spreads to neighboring cells, causing multiple cells to enter thermal runaway, often referred to as a “thermal cascade” or “thermal propagation.” Once a thermal cascade / propagation begins, it can be difficult to stop, and the resulting failure can be costly and / or dangerous.24POLY0063-WO-ORD 2SUMMARY

[0005] In an example implementation, a thermal management apparatus includes a multilayered sheet that includes a thermally insulating core including a first surface and a second surface opposite the first surface; a first thermally conductive layer that is disposed to a first portion of the first surface of the thermally insulating core; and a second thermally conductive layer that is disposed to a first portion of the second opposite surface of the thermally insulating core. Each of the first surface and the second surface of the thermally insulating core includes a second portion exposed to an environment.

[0006] An aspect combinable with the example implementation includes a first plurality of thermally conductive layers that includes the first thermally conductive layer.

[0007] In another aspect combinable with one, some, or all of the previous aspects, each layer of the first plurality of thermally conductive layers is disposed to a portion of the first surface of the thermally insulating core.

[0008] Another aspect combinable with one, some, or all of the previous aspects includes a second plurality of thermally conductive layers that includes the second thermally conductive layer.

[0009] In another aspect combinable with one, some, or all of the previous aspects, each layer of the second plurality of thermally conductive layers is disposed to a portion of the second surface of the thermally insulating core .

[0010] In another aspect combinable with one, some, or all of the previous aspects, at least two layers of the first plurality of thermally conductive layers are separated by a first clearance.

[0011] In another aspect combinable with one, some, or all of the previous aspects, at least two layers of the second plurality of thermally conductive layers are separated by a second clearance.

[0012] In another aspect combinable with one, some, or all of the previous aspects, the first and second clearances are substantially equal.

[0013] In another aspect combinable with one, some, or all of the previous aspects, the thermally insulating core includes a glass filled polypropylene blend with a Glow-Wire Flammability (GWFI) value of about 900 or greater, as measured according to IEC 60695-2-12.24POLY0063-WO-ORD 3

[0014] In another aspect combinable with one, some, or all of the previous aspects, a glass content in the glass filled polypropylene blend is at least about 20 wt% to about 40 wt% by total weight of the blend.

[0015] In another aspect combinable with one, some, or all of the previous aspects, the thermally insulating core has a thickness value of at least about 0.5 mm to at least about 3 mm, preferably, from at least about 1 mm to at least about 2.5 mm, and more preferably, from at least about 1.5 mm to at least about 2 mm.

[0016] In another aspect combinable with one, some, or all of the previous aspects, a minimum thickness of the first thermally conductive layer and the second thermally conductive is about 0.1 mm, preferably, the minimum thickness is about 0.3 mm, and more preferably, the minimum thickness is about 0.5 mm.

[0017] In another aspect combinable with one, some, or all of the previous aspects, the first thermally conductive layer and second thermally conductive layer include one or more perforated regions; and the thermally insulating core is exposed to the environment at the one or more perforated regions.

[0018] In another aspect combinable with one, some, or all of the previous aspects, at least one of the one or more perforated regions is at least one of oval, circular, rectangular, square, triangular, or polygonal, and the one or more perforated regions are arranged in a uniform pattern, a non-uniform pattern, or a random pattern.

[0019] Another aspect combinable with one, some, or all of the previous aspects includes a battery pack that includes one or more battery cells; and a bus bar configured to electrically connect the one or more battery cells.

[0020] In another aspect combinable with one, some, or all of the previous aspects, the multilayered sheet is configured to be disposed on a portion of an outer surface of the one or more battery cells.

[0021] In another aspect combinable with one, some, or all of the previous aspects, an external shape of the battery pack is hexagonal, square, or octagonal.

[0022] In another aspect combinable with one, some, or all of the previous aspects, the one or more battery cells includes one or more cylindrical type battery cells or one or more prismatic type battery cells.24POLY0063-WO-ORD 4

[0023] In another aspect combinable with one, some, or all of the previous aspects, the multilayered sheet is configured to accommodate foaming and charring of the thermally insulating core during a thermal runaway event in such a way that the multilayered sheet substantially prevents propagation of the thermal runaway event.

[0024] Example implementation according to the present disclosure can include one, some, or all of the following features. For example, example implementations can improve the mitigation and control of thermal propagation from one battery cell to another during a thermal runaway event, thereby reducing the risk of a thermal cascade and damage to the battery pack.

[0025] In another aspect combinable with one, some, or all of the previous aspects, a material of the thermally insulating core includes one or more insulative properties such that, at a particular distance, the one or more insulative properties is sufficient to maintain heat conductivity between adjacent battery cells so a temperature of a first battery cell of the adjacent cells is less than an auto-ignition temperature of a second battery cell of the adjacent cells.

[0026] The disclosure described herein addresses this need by providing a thermal management apparatus that can include a multilayered sheet and a battery pack design with integrated features. These features manage and / or control the heat generated during normal charging and discharging of the battery, and during thermal runaway, preventing it from spreading to other cells in the pack and enhancing the overall safety and reliability of a battery pack system.

[0027] Features which are described in the context of separate aspects, implementations, and embodiments of the disclosure may be used together and / or be interchangeable. Similarly, features described in the context of a single embodiment or implementation may also be provided separately or in any suitable sub / combination.BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and other features, aspect, and advantages of the present disclosure are better understood when the following detailed description of the disclosure is read with reference to the accompanying drawings, in which:

[0029] FIG. 1 is a schematic cross section drawing of an example implementation of a multilayered sheet.

[0030] FIG. 2 is schematic cross section of another example implementation of the multilayered sheet with different configurations.24POLY0063-WO-ORD 5

[0031] FIG. 3 is a schematic cross section of another example implementation of the multilayered sheet with different thermally conductive layers configurations.

[0032] FIG. 4 is a side perspective view of the multilayered sheet shown in FIG. 5.

[0033] FIG. 5 is a schematic cross section of another example implementation of the multilayered sheet with different thermally conductive layers configurations.

[0034] FIG. 6 is an illustrative drawing and example of a lab scale battery experiencing change in temperatures, specifically, the charring behavior of glass filled thermoplastics.

[0035] FIG. 7A is a prospective view of a further example implementations of the multilayered sheet with perforated thermally conductive layers

[0036] FIG. 7B is a prospective view of a cross section of the multilayered sheet shown in FIG. 7A.

[0037] FIG. 7C a schematic cross section of the multilayered sheet shown in FIG. 7A integrated between battery cells.

[0038] FIG. 8 is a top view that shows another example implementation of the multilayered sheet integrated in a battery pack with one or more battery cells and a bus bar.

[0039] FIG. 9A is a perspective view of a cylindrical battery cells with the multilayered sheet being integrated between battery cells.

[0040] FIG. 9B is a is a perspective view of a prismatic or pouch battery cells with the multilayered sheet being placed between battery cells.

[0041] FIG. 9C shows a top view of a schematic hexagonal battery pack arrangement.

[0042] FIG. 9D shows a top view of a schematic square battery pack arrangement.

[0043] FIG. 10 is a schematic cross section of another example implementation of the multilayered sheet.DETAILED DESCRIPTION

[0044] In typical battery packs, especially those used in EVs and large energy storage systems, individual battery cells are densely packed together to maximize energy density. Unfortunately, this close packing increases the risk of thermal runaway propagation, where the heat from an affected cell spreads to neighboring cells, causing multiple cells to enter thermal runaway, often referred to as a “thermal cascade” or “thermal propagation.” Once a thermal24POLY0063-WO-ORD 6 cascade or thermal propagation begins, it can be difficult to stop, and the resulting failure can be costly and / or dangerous.

[0045] The current solutions in the market utilize heat shields or on active cooling systems, which may not be effective in preventing the spread of heat between cells once thermal runaway has begun, or they can introduce additional complexity and cost to the battery system. For example, heat shield or barriers tend to expand, foam, and / or char when exposed to heat, causing the excess material to overflow to adjacent cells or impacting the integrity of the shield or barrier. As used herein, the term battery cells can, in some aspects, refer to individual electrochemical cells that store and provide electrical energy. Each battery cell can have a specific shape, such as cylindrical, prismatic, or pouch, and can contain the necessary components for energy storage, including electrodes, electrolyte, and a casing. Battery cells can be arranged in various configurations to form a battery pack that may have different shapes.

[0046] In addition, a battery cell should maintain cell temperature during normal operation of charging and discharging. For normal operation, heat conductive material would be preferred but for a thermal runaway event, heat insulating material would be preferred. During normal operation of charging or discharging of cells within a battery pack, there is heat generation by the cells that result in increased cell temperature. This heat must be taken out from the cells to maintain the temperature in the optimal range so that life and state of health of the cells is maintained for longer duration. Presently, materials like TIM or PCM are used between cells that absorb / transfer the heat generated during normal operation. For thermal runaway, other materials like mica sheets or aerogel mats are used to limit cell to cell TRA propagation. Alternatively, an active cooling system can also used in the battery pack to main cell temperatures.

[0047] It is, therefore, an object of various example implementations to provide an improved thermal management apparatus that improve the mitigation and control of thermal propagation from one battery cell to another during a thermal runaway event, as well as maintain or help maintain battery cell temperature during normal operation of charging and discharging. The disclosure described herein addresses this need by providing a thermal management apparatus that includes a multilayered sheet with integrated features that include integration of thermally conductive materials (e.g., Al / TIM / PCM) and thermally insulative materials (e.g., STAMAX™ 30YH570 or PPc H1030) for better heat extraction and transfer during normal operation as well as enhanced thermal runaway propagation performance.24POLY0063-WO-ORD 7

[0048] For example, the present disclosure shows perforation features in one or more thermally conductive layer that can be disposed to a thermally insulating core. Further, the present disclosure shows that, in some example implementations, one or more clearances are created or being created between the thermally conductive layers, exposing the thermally insulating core to the environment. Additionally, in example aspects, the thermally conductive layers are designed and disposed in such a way that makes one or more portions of the thermally insulating core uncovered and exposed to the environment. These features can enable the thermally insulating core to expand during a thermal runaway event without substantially compromising the integrity of the thermal management apparatus or battery pack.

[0049] With reference now to the figures, and in particular to the figures, an example implementation of a thermal management apparatus that includes a multilayered sheet 100B with a thermally insulating core 101 A, a first thermally conductive layer, and a second thermally conductive layer is shown. In example implementations, a thermal management apparatus can include a multilayered sheet, for example, 100B, 100A, 200B, 700A, 850, and / or 901A, and a battery pack 800.

[0050] FIG. 1 illustrates a cross sectional view of the multilayered sheet 100B that includes a thermally insulating core 101 A having a first surface 101.1 A and a second opposite surface 101.2A, a first thermally conductive layer 103B, and a second thermally conductive layer 102B. The thermally insulating core 101 A occupies the central position of the multilayered sheet 100B. The first thermally conductive layer 103B is disposed to (e.g., attached to or otherwise in contact with) the first surface 101.1 A of the thermally insulating core 101 A, while the second thermally conductive layer 102B is being disposed to (e.g., attached to or otherwise in contact with) the second opposite surface 101.2A of the thermally insulating core 101 A.

[0051] In some example implementations, the first thermally conductive layer 103B and the second thermally conductive layer 102B can extend to substantially match the dimensions of the thermally insulating core 101 A, for example, in terms of length and width. This configuration creates a symmetrical or substantial symmetrical structure or sheet, making the thermally insulating core 101A, the first thermally conductive layer 103B, and the second thermally conductive layer 102B share identical or substantially identical boundaries, as shown in FIG. 1.

[0052] FIG. 2 shows a cross section of an example aspect of a multilayered sheet 100 A. FIG. 2 shows a cross section view of a multilayered sheet 100 A that includes a thermally insulating24POLY0063-WO-ORD 8 core 101 A having a first surface 101.1 A and a second opposite surface 101.2A, a first thermally conductive layer 103 A, and a second thermally conductive layer 102A. The thermally insulating core 101 A occupies the central position of the multilayered sheet 100 A. The first thermally conductive layer 103 A is disposed to (e.g., attached to or otherwise in contact with) the first surface 101.1 A of the thermally insulating core 101 A, while the second thermally conductive layer 102A is being disposed to (e.g., attached to or otherwise in contact with) the second opposite surface 101.2A of the thermally insulating core 101 A. The first thermally conductive layer 103 A extends partially over a first portion of the first surface 101.1 A of the thermally insulating core 101 A, leaving a second portion 105A of the first surface 101.1 A uncovered and can be exposed to an environment (e.g., a volume within a battery cell apparatus), as shown in FIG. 2. In some example implementations, the second thermally conductive layer 102 A extends partially over a first portion of the second opposing surface 101.2A of the thermally insulating core 101 A, leaving a second portion 105B of second opposing surface 101.2 A uncovered and can expose the second portion 105B to the environment.

[0053] In example aspects, the second portion 105A of the first surface 101.1 A and the second portion 105B of the second opposing surface 101.2A can vary in dimensions such that the length (L) and width (W) of the exposed portions 105 A and 105B are not fixed or not substantially fixed. These dimensions L and W of the second portion 105A of the first surface 101.1 A and the second portion 105B of the second opposing surface 101.2A can be adjusted according to design and application requirements.

[0054] In example implementations, the multilayered sheet 100 A can have two second portions 105A and 105B being uncovered. For example, the first thermally conductive layer 103 A can extend partially over a first portion of the first surface 101.1 A of the thermally insulating core 101 A, leaving a second portion 105A of the first surface 101.1 A uncovered, and the second thermally conductive layer 102 A can extend partially over a first portion of the second opposing surface 101.2A of the thermally insulating core 101 A, leaving a second portion 105B of second opposing surface 101.2 A uncovered and expose the second portion 105B to the environment.

[0055] In some example implementations, a multilayered sheet 200B can include a first plurality of thermally conductive layers 202A and a second plurality of thermally conductive layer 202B, as shown in FIG. 3 and FIG. 4. For example, the first thermally conductive layer 103B is included in the first plurality of thermally conductive layers 202A, and the second thermally24POLY0063-WO-ORD 9 conductive layer 102B is included in the second plurality of thermally conductive layers 202B. Further, each layer of the first plurality of thermally conductive layers is disposed to the first surface 101.1 A of the thermally insulating core 101 A, and each layer of the second plurality of thermally conductive layers 202B is disposed to the second opposite surface 101.2A of the thermally insulating core 101 A.

[0056] In various example implementations, each layer of the first plurality of thermally conductive layers 202A and / or the second plurality of thermally conductive layer 202B can extend to substantially match the dimensions of the thermally insulating core 101 A, for example, in terms of length and width, as shown in FIG. 3, FIG. 4, and FIG. 5.

[0057] In other examples, one or more layers of the first plurality of thermally conductive layers 202A and / or the second plurality of thermally conductive layer 202B can extend to substantially match the dimensions of the thermally insulating core 101A, for example, in terms of length and width. In other aspects, one or more layers of only the first plurality of thermally conductive layers 202A can extend to substantially match the dimensions of the thermally insulating core 101 A, for example, in terms of length and width. In other examples, one or more layers of only the second plurality of thermally conductive layers 202B can extend to substantially match the dimensions of the thermally insulating core 101 A, for example, in terms of length and width.

[0058] FIG. 3 shows a cross sectional view of an example implementation of the multilayered sheet 200B with the first plurality of thermally conductive layers 202A and the second plurality of thermally conductive layers 202B. Additionally, FIG. 3 shows an example aspect in which two layers of the first plurality of thermally conductive layers 202A can be separated by a first clearance 203A. Further, two layers of the second plurality of thermally conductive layers 202B can be separated by a second clearance 203B, as shown in FIG. 3. In some aspects, each of the first clearance 203A and the second clearance 203B can be equal or substantially equal in dimension.

[0059] FIG. 5 shows a cross sectional view of another example implementation in which three layers of the first plurality of thermally conductive layers 202A and the second plurality of thermally conductive layers 202B can be separated by one or more clearances. For example, the first plurality of thermally conductive layers 202A can have a first clearance 303A and a second24POLY0063-WO-ORD 10 clearance 304 A, and the second plurality of thermally conductive layers can have a first clearance 303B and a second clearance 304B, as shown in FIG. 4 and FIG. 5.

[0060] In example implementations, the clearances 203B, 203A, 303A, 304A, 303B, and 304B can vary in dimensions and / or shapes such that such that the length (L), width (W), and shape of clearances 203B, 203 A, 303 A, 304A, 303B, and 304B may not be fixed or substantially fixed, and can be adjusted according to design and application requirements.

[0061] The clearances 203B, 203A, 303A, 304A, 303B, and 304B, and the uncovered portions 105 A and 105B can enable the thermally insulating core 101 A to expand during a thermal runaway event without compromising or substantially compromising the integrity of the thermal management apparatus. For example, thermoplastic and glass filled thermoplastics can have good thermal and electrical insulation properties. However, such materials can expand, foam, and / or char when exposed to heat. This surface and dimensional changes can impact the integrity and properties of such materials, especially in multilayered sheet design. As used herein, the terms charring or foaming can, in some aspects, refer to a chemical decomposition or surface properties changes that leaves behind a carbon rich residue, which forms a protective layer on the surface, and can improve thermal insulating properties. Such layer can help to reduce heat transfer from one cell to other, neighboring cells. Further, the thermoplastic used herein can, in some aspects, include, but are not limited to, polycarbonate, polymethyl methacrylate, polyethylene terephthalate, polyvinyl chloride, polyethylene, and polypropylene.

[0062] FIG. 6 shows a representative example of a battery prototype that uses a glass filled polypropylene blend in its pack design. When exposed to heat, the glass polypropylene exhibits charring and / or foaming. This example is provided for illustrative purposes only, to demonstrate the behavior of thermoplastics and / or glass filled thermoplastics when exposed to change in temperatures.

[0063] FIG. 7A shows a prospective view of a further example implementations of a multilayered sheet 700A with a first perforated thermally conductive layer 702A and a second perforated thermally conductive layer 702B. The thermally insulating core 101A occupies the central position of the multilayered sheet 100B. The first perforated thermally conductive layer 702A is disposed to the first surface 101.1 A of the thermally insulating core 101 A, while the second perforated thermally conductive layer 702B is disposed to the second opposite surface24POLY0063-WO-ORD 11 the environment and is uncovered at the perforated regions 701. In example implementations, the first perforated thermally conductive layer 702A and / or the second perforated thermally conductive layer 702B can have one or more perforated regions. Further, the perforated regions, for example 701, can have different shapes and sizes, and can be arranged in different patterns. For example, in various aspects, the perforated regions, for example 701, can be oval, circular, rectangular, square, triangular, and / or irregular. In further aspects, the perforated regions, for example 701 can be in uniform pattern, nonuniform pattern, and / or random pattern.

[0064] As used herein, the term perforation can, in some aspects, refer to alteration and / or discontinuity in a sheet. For example, perforations can include holes, cuts, or other disruptions in the material, varying in size, shape, depth, pattern, and arrangement, and may or may not pass entirely through the sheet or its individual layers.

[0065] FIG. 7B shows a prospective view of a cross section of the multilayered sheet 700A with the first perforated thermally conductive layer 702A and the second perforated thermally conductive layer 702B.

[0066] FIG. 7C shows the multilayered sheet 700A with the first perforated thermally conductive layer 702A and the second perforated thermally conductive layer 702B disposed to or integrated between at least two battery cells A and B. The first perforated thermally conductive layer 702A is configured to be disposed on a portion 1 A of an outer surface of battery cell A, and the second perforated thermally conductive layer 702B is configured to be disposed on a portion IB of an outer surface of battery cell B. The thermally insulating core 101 A is exposed to the environment and is uncovered at the perforated regions 701. In example implementations, when the thermally insulating core 101A is exposed to change in temperatures, for example, as a result of a thermal runaway event, the core 101A can expand, foam, and / or char in these regions 701 without impacting or substantially impacting the sheet’s 700A structure or integrity.

[0067] In example implementations, the multilayered sheet 700A with the first perforated thermally conductive layer 702A and the second perforated thermally conductive layer 702B can extend to substantially match the dimensions of the battery cells A and B, for example, in terms of length and width, as shown in FIG. 7 A, FIG. 7B, and FIG. 7C. Additionally, in further implementations, the multilayered sheet 700A with the first perforated thermally conductive layer 702A and the second perforated thermally conductive layer 702B can be configured and designed such that it does not match or substantially match the dimensions of any given battery cells. For24POLY0063-WO-ORD 12 example, the multilayered sheet 700A can be integrated to occupy a central portion, bottom portion, and / or a top portion of the battery cell A and B or alternatively, the battery pack 800.

[0068] In further aspects, the first perforated thermally conductive layer 702 A and the second perforated thermally conductive layer 702B can extend to substantially match the dimensions of the of the thermally insulating core 101 A, for example, in terms of length and width, as shown in FIG. 7A, FIG. 7B, and FIG. 7C. Additionally, in further implementations, the first perforated thermally conductive layer 702A and the second perforated thermally conductive layer 702B can be configured and designed such that it does not match or substantially match the dimensions of the thermally insulating core 101 A.

[0069] In further example implementations, the thermal management apparatus can further include a battery pack 800 with one or more battery cells 801, a bus bar 802 that can be configured to electrically connect the one or more battery cells, and a multilayered sheet 810 that can be configured to be disposed on a portion of an outer surface 803 of the one or more battery cells 801, as shown in FIG. 8.

[0070] In some aspects, the bus bar 802 is or includes a conductive strip or bar that is used to distribute electrical power within the battery pack 800. The bus bar 802 connects multiple battery cells electrically 801, facilitating the transfer of current and ensuring proper power distribution across the system. Further, the material of the bus bar 802 can vary and can include metals such as copper or aluminum, or other materials with relatively high electrical conductivity.

[0071] The one or more battery cells 801 can have different shapes, sizes, and arrangements. For example, the battery cells can be cylindrical type battery cells 801.1 or prismatic type battery cells 801.2, as shown in FIGS. 9A and 9B. Additionally, the one or more battery cells 801 can have hexagonal or square shape or arrangement, as shown in FIG. 9C and FIG. 9D.

[0072] In example aspects, the multilayered sheet 810 that can be configured to and designed to fit between the one or more battery cells 801 regardless of the shape, size, and / or arrangements of the cells 801, for example, the multilayered sheet 810 can be wavy, straight, or other configurations, to accommodate the different cell types and arrangements. For example, FIG. 9A shows a perspective view of cylindrical battery cells 901 A and a multilayered sheet 902A that is design in such a way that can be inserted or fitted between the cylindrical cells 901 A. FIG.24POLY0063-WO-ORD 139B is another example of a prismatic-type battery cells 90 IB that shows another design of a multilayered sheet 902B that can be inserted or fitted between prismatic type battery cells 901B.

[0073] In example implementations, the thickness, for example, 555 A, of the thermally insulating core 101 A can be at least, equal to, and / or between any two of 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, and 1 mm. In other example implementations, the thickness 555 A of the thermally insulating core 101 A can be at least, equal to, and / or between any two of 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, and 4 mm. In In yet other example implementations, the thickness 555A of the thermally insulating core 101A can be at least, equal to, and / or between any two of 1 mm, 1.5 mm, and 2 mm. in further examples, the thickness of the thermally insulating core 101 A can be greater than 4 mm.

[0074] In example aspects, the minimum thickness, for example, 555B, of the first thermally conductive layer and / or the second thermally conductive can be at least, equal to, and / or between any two of 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, and 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, and 2 mm.

[0075] In example implementations, the thermally insulating core 101 A can include glass filled thermoplastic. The thermoplastic used herein can, in some aspects, be any suitable material that exhibits the necessary characteristics for the intended application. Examples of such thermoplastics can include, but are not limited to, polycarbonate, polymethyl methacrylate, polyethylene terephthalate, polyvinyl chloride, polyethylene, and polypropylene.

[0076] In further example implementations of the present disclosure, the thermally insulating core 101 A can include glass filled polypropylene. The polypropylene can be a polypropylene homopolymer or a polypropylene copolymer, either including random copolymers, (multi)block copolymers or any other combination.

[0077] The glass can be hollow glass bubble, fiber, or any other suitable glass additives. Additionally, the glass used in the glass filled thermoplastic blend (e.g., polypropylene), can be in an amount from 1 wt% to 40 wt% by total weight of the thermoplastic blend. In example aspects, the glass can be used in an amount of at least, equal to, and / or between any two of 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 29 wt%, 30 wt%, 31 wt%, 32 wt%, 33 wt%, 34 wt%, 35 wt%, 36 wt%, 37 wt%, 38 wt%, 39 wt%, and 40 wt% by total weight of the thermoplastic blend.24POLY0063-WO-ORD 14

[0078] In example implementations, the thermoplastic blend (e.g., polypropylene) used for producing the thermally insulating core 101A and / or other components of the thermal managements apparatus can have a tensile modulus at 23 °C 6000 MPa to 9000 MPa, or at least, equal to, and / or between any two of 6000 MPa, 6200 MPa, 6400 MPa, 6600 MPa, 6800 MPa, 7000 MPa, 7200 MPa, 7400 MPa, 7600 MPa, 7800 MPa, 8000 MPa, 8200 MPa, 8400 MPa, 8600 MPa, 8800 MPa, and 9000 MPa, as measured by ISO 527 / 1 A.

[0079] Further, the Charpy Impact Strength Notched of the thermoplastic blend (e.g., polypropylene) at 23 °C can be from 10 kJ / m2 to 20 kJ / m2 or at least, equal to, and / or between any two of 10 kJ / m2, 12 kJ / m2, 14 kJ / m2, and 16 kJ / m2, 18 kJ / m2, and 20 kJ / m2, as measured by ISO 179 / leA.

[0080] The Izod notched impact strength of the thermoplastic blend (e.g., polypropylene) at 23 °C can be from 5 kJ / m2 to 15 kJ / m2 or at least, equal to, and / or between any two of 5 kJ / m2, 5 kJ / m2, 6 kJ / m2, 7 kJ / m2, 8 kJ / m2, 9 kJ / m2, 10 kJ / m2, 11 kJ / m2, 12 kJ / m2, 13 kJ / m2, 14 kJ / m2, and 15 kJ / m2 22 kJ / m2, as measured by ISO 180 / 1 A.

[0081] The coefficient of linear thermal expansion (CTE) of the thermoplastic blend (e.g., polypropylene) at -30 °C to 100°C can be from 40 pm / mK to 60 pm / mK, or at least, equal to, and / or between any two of 41 pm / mK, 42 pm / mK, 43 pm / mK, 44, pm / mK, 45 pm / mK, 46 pm / mK, 47 pm / mK, 48 pm / mK, 49 pm / mK, 50 pm / mK, 51 pm / mK, 52 pm / mK, 53 pm / mK, 54 pm / mK, 55 pm / mK, 56 pm / mK, 57 pm / mK, 58 pm / mK, 59 pm / mK, and 60 pm / mK, as measured by ISO 11359-2.

[0082] In further aspects, the thermoplastic blend (e.g., polypropylene) used for producing the thermally insulating core 101A and / or other components of the thermal managements apparatus can have a Glow-Wire Flammability (GWFI) value of at least, equal to, and / or between any two of 720, 740, 760, 780, 800, 820, 840, 860, 880, 900, 920, 940, 960, 980, and 1000, as measured according to IEC 60695-2-12. In further example implementations, the thermoplastic blend (e.g., polypropylene) used for producing the thermally insulating core 101A and / or other components of the thermal managements apparatus can have a Glow-Wire Flammability (GWFI) value of greater than 1000, as measured according to IEC 60695-2-12.

[0083] In example aspects, the glass filled polypropylene used for producing the thermally insulating core 101A and / or other components of the thermal managements apparatus can have a Glow-Wire Flammability (GWFI) value of at least, equal to, and / or between any two of 720, 740,24POLY0063-WO-ORD 15760, 780, 800, 820, 840, 860, 880, 900, 920, 940, 960, 980, and 1000, as measured according to IEC 60695-2-12. In further examples, the glass filled polypropylene used for producing the thermally insulating core 101A and / or other components of the thermal managements apparatus can have a Glow-Wire Flammability (GWFI) value of greater than 1000, as measured according to IEC 60695-2-12.

[0084] FIG. 10 illustrates a cross sectional view of a multilayered sheet 100C that includes the thermally insulating core 101 A having a first surface 101.1 A and a second opposite surface 101 ,2A (not shown in this figure), a first thermally conductive layer 300A, and a second thermally conductive layer 300B. The thermally insulating core 101 A occupies the central position of the multilayered sheet 100C. The first thermally conductive layer 300A is disposed to (e.g., attached to or otherwise in contact with) the first surface of the thermally insulating core 101A, while the second thermally conductive layer 300B is being disposed to (e.g., attached to or otherwise in contact with) the second opposite surface of the thermally insulating core 101 A. In example implementations, the first thermally conductive layer and / or the second thermally conductive, for example, 300 A and 300B, can include heat conduction materials for better heat transfer and dissipation during a thermal runaway event. Such materials can be aluminum, aluminum alloy, copper, copper alloy, graphite, magnesium, magnesium alloy, silver, gold and / or metal oxide.

[0085] In alternative example implementations, the first thermally conductive layer and / or the second thermally conductive, for example, 300A and 300B, can include a material that is not necessarily thermally conductive but can receive thermal energy. For example, the layers 300A and 300B can be phase change materials (PCMs), such as paraffin wax, salt hydrates, or fatty acids.

[0086] In other examples, the first thermally conductive layer and / or the second thermally conductive, for example, 300A and 300B, can include thermal interface materials (TIMs), such as silicone-based compounds, graphite sheets, and / or carbon nanotube composites,

[0087] Other various implementations can include polymeric composites doped with conductive fillers like graphene, boron nitride, or carbon black. Further, the first thermally conductive layer and / or the second thermally conductive, for example, 300A and 300B, can be polymeric composites that include aluminum, aluminum alloy, copper, copper alloy, graphite, magnesium, magnesium alloy, silver, gold and / or metal oxide, PCMs, conductive oxides, and / or TIMs.24POLY0063-WO-ORD 16

[0088] The multilayered sheet, for example, 100B, 100A, 200B, 700A, 850, and / or 901A, including the first and second thermally conductive layers, for example, 300A, 300B, 103B, 102B, 103A, 102A, 202B, 202A, and 702A, and the thermally insulating 101A can be manufactured using several methods depending on the materials and desired design. For example, thermal interface material TIM adhesive tapes can be applied to both sides of the core 101 A, creating a strong bond between the core 101 A and the first and second thermally conductive layers, for example, 300A, 300B, 103B, 102B, 103 A, 102A, 202B, 202A, and 702A while assuring efficient thermal transfer. In an extrusion process, the thermally insulating core 101 A material can be extruded and then thermoformed, with conductive layers such as aluminum, copper, or graphite sheets applied and bonded through heat and / or pressure.

[0089] In example aspects of manufacturing, injection molding can be deployed in which the core 101 A can be molded first, followed by over-molding with a conductive material like aluminum or other metals.

[0090] In other example aspects of manufacturing, coextrusion process can be used in which the core 101 A can be simultaneously extruded with conductive layers like aluminum laminate films (ALF) or other metallic or composite materials.

[0091] Alternatively, roll-to-roll lamination can bond pre-formed conductive films or foils onto the core 101A under heat and / or pressure. Adhesive bonding techniques can also be used, including epoxy, polyurethane, or pressure-sensitive adhesives, to attach the thermally conductive layers to the core 101 A, depending on the materials and environmental conditions.

[0092] Other variations can include vapor deposition or sputtering processes to coat the core with a thin layer of conductive material. Further, mechanical fastening or embedding conductive materials into grooves or recesses in the core, for example, 101A, can provide alternative attachment methods for specialized applications. It is of note that variations in the manufacturing process can be made without departing from the scope of this disclosure, including but not limited to the use of alternative materials, molding techniques, or post-processing steps to achieve similar or improved performance features.

[0093] Throughout the description, specific details have been set forth in order to provide a more thorough understanding of the present disclosure. However, this disclosure can be practiced without these particulars. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive, sense. It will be clear to one having skill in the art that24POLY0063-WO-ORD 17 various modifications, adaptation, and alternative implementations, as well as further variations to the specific details disclosed herein, can be made, resulting in other embodiments or implementations that are within the scope of the present disclosure. All parameters, proportions, materials, and configurations described herein are examples only and can be changed depending on the specific embodiment.

[0094] Further, the terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, an apparatus or kit that “comprises,” “has,” “includes” or “contains” one or more elements possesses those one or more elements but is not limited to possessing only those elements. Further, an apparatus, device, component, or system that is configured in a certain way is configured in at least that way, but it can also be configured in other ways than those specifically described.

Claims

24POLY0063-WO-ORD 18CLAIMS1. A thermal management apparatus, comprising: a multilayered sheet that includes: a thermally insulating core comprising a first surface and a second surface opposite the first surface; a first thermally conductive layer that is disposed to a first portion of the first surface of the thermally insulating core; and a second thermally conductive layer that is disposed to a first portion of the second opposite surface of the thermally insulating core; wherein each of the first surface and the second surface of the thermally insulating core includes a second portion exposed to an environment.

2. The thermal management apparatus of claim 1, comprising: a first plurality of thermally conductive layers that includes the first thermally conductive layer, each layer of the first plurality of thermally conductive layers is disposed to a portion of the first surface of the thermally insulating core; a second plurality of thermally conductive layers that includes the second thermally conductive layer, each layer of the second plurality of thermally conductive layers is disposed to a portion of the second surface of the thermally insulating core .

3. The thermal management apparatus of claim 2, wherein at least two layers of the first plurality of thermally conductive layers are separated by a first clearance.

4. The thermal management apparatus of claim 3, wherein at least two layers of the second plurality of thermally conductive layers are separated by a second clearance.

5. The thermal management apparatus of claim 4, wherein the first and second clearances are substantially equal.

6. The thermal management apparatus of any one of claims 1 - 5, wherein the thermally insulating core comprises a glass filled polypropylene blend with a Glow-Wire Flammability (GWFI) value of about 900 or greater, as measured according to IEC 60695-2-12.24POLY0063-WO-ORD 197. The thermal management apparatus of claim 6, wherein a glass content in the glass filled polypropylene blend is at least about 20 wt% to about 40 wt% by total weight of the blend.

8. The thermal management apparatus of any one of claims 1 - 7, wherein the thermally insulating core has a thickness value of at least about 0.5 mm to at least about 3 mm, preferably, from at least about 1 mm to at least about 2.5 mm, and more preferably, from at least about 1.5 mm to at least about 2 mm.

9. The thermal management apparatus of any of claims 1 - 8, wherein a minimum thickness of the first thermally conductive layer and the second thermally conductive is about 0.1 mm, preferably, the minimum thickness is about 0.3 mm, and more preferably, the minimum thickness is about 0.5 mm.

10. The thermal management apparatus of any one of claims 1 - 9, wherein the first thermally conductive layer and second thermally conductive layer include one or more perforated regions; and the thermally insulating core is exposed to the environment at the one or more perforated regions.

11. The thermal management apparatus of claim 10, wherein at least one of the one or more perforated regions is at least one of oval, circular, rectangular, square, triangular, or polygonal, and the one or more perforated regions are arranged in a uniform pattern, a non- uniform pattern, or a random pattern.

12. The thermal management apparatus of any one of claims 1 - 11, comprising a battery pack that includes: one or more battery cells; and a bus bar configured to electrically connect the one or more battery cells; and wherein the multilayered sheet is configured to be disposed on a portion of an outer surface of the one or more battery cells.

13. The thermal management apparatus of claim 12, wherein an external shape of the battery pack is hexagonal, square, or octagonal.24POLY0063-WO-ORD 2014. The thermal management apparatus of either one of claims 12 or 13, wherein the one or more battery cells comprises one or more cylindrical type battery cells or one or more prismatic type battery cells.

15. The thermal management apparatus of any one of claims 1 - 14, wherein the multilayered sheet is configured to accommodate foaming and charring of the thermally insulating core during a thermal runaway event in such a way that the multilayered sheet substantially prevents propagation of the thermal runaway event.

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