Thermal barrier components for battery assemblies, and battery assemblies

Abstract

A thermal barrier component (10) for a battery assembly (50) includes a stack of layers (11), the stack (11) comprising a core layer (12) and at least one thermal insulation layer (14) disposed on at least one side of the core layer (12), the core layer (12) comprising an inlet (18) made of a rigid material, preferably a rigid foam material or an aluminum honeycomb structure, and a frame element (20) surrounding the inlet (18) in a circumferential direction.

Description

[Technical Field]

[0001] The present invention relates to thermal barrier components for battery assemblies, specifically thermal barrier components for battery assemblies used in electric aircraft, such as electric vertical take-off and landing (eVTOL) aircraft, and processes for manufacturing thermal barrier components. Furthermore, protection for battery assemblies comprising such thermal barrier components, and protection for processes for manufacturing battery assemblies are also claimed. [Background technology]

[0002] Under certain conditions, such as electrical failures or poor cooling, high-energy-density rechargeable battery assemblies, including those based on lithium-ion batteries, may experience thermal runaway.

[0003] These batteries typically comprise multiple battery modules, each battery module containing at least one battery cell, preferably several stacked battery cells, for example, each battery module containing at least six battery cells.

[0004] In the event of thermal runaway, the affected battery module generates a significant amount of heat. If there is insufficient insulation between adjacent modules, the high temperature can cause adjacent modules to experience thermal runaway, and thus the thermal runaway can propagate throughout the entire battery assembly.

[0005] In particular, when the device is an aircraft, it is necessary to prevent thermal runaway occurring within a given battery cell module from propagating to adjacent modules in order to ensure the safety of the device in which the battery assembly is used.

[0006] For example, the temperature inside an affected battery module could reach up to 1500°C during a thermal runaway event, but the temperature of adjacent modules should still not exceed, for example, 130°C, to avoid triggering a propagation reaction.

[0007] A conventional technique known as battery potting involves embedding battery cells within a resin material for the purpose of providing insulation, as well as shock and vibration resistance. However, battery potting requires a fairly complex assembly process, which significantly increases the weight of the resulting assembly.

[0008] Another known solution is to provide a thermal barrier component with low thermal conductivity as insulation between adjacent battery cell modules.

[0009] However, during thermal runaway, not only high temperatures but also high pressures are generated, resulting in high mechanical loads and corrosion processes caused by high-speed particles. [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] Against this backdrop, the object of the present invention is to provide an improved type of thermal barrier component that is lightweight, easily integrated into a battery assembly, and suitable for resisting the thermal load, high pressure, and mechanical load generated during thermal runaway in order to contain the reaction and prevent or reduce the propagation of thermal runaway to adjacent battery cell modules. [Means for solving the problem]

[0011] This objective is achieved by a thermal barrier component for a battery assembly having the features described in claim 1, and a process for manufacturing a thermal barrier component having the features described in claim 17.

[0012] The thermal barrier component according to the present invention includes a stack of layers, the stack including a core layer and at least one thermal insulation layer and / or corrosion barrier layer disposed on at least one side surface of the core layer, the core layer including an inlet containing a rigid material, preferably a rigid foam material, and a frame element surrounding the inlet in a circumferential direction.

[0013] One of the main ideas of the present invention is to form thermal barrier components as a multilayer stack, where different functions of the components, such as providing resistance to high mechanical loads or pressures on the one hand, and resistance to high thermal loads on the other, are provided by different layers that are tuned to the respective functions of those components.

[0014] Thermal barrier components serve a dual purpose as both thermal barriers and structural components by connecting to the battery housing and contributing to the overall rigidity of the battery assembly and its resistance to overpressure from thermal runaway events.

[0015] The thermal barrier component according to the present invention can be used to define and isolate compartments within a battery assembly, each compartment housing, for example, a battery cell module containing 6 to 18 stacked battery cells, particularly pouch cells.

[0016] In particular, the thermal barrier component can be configured to withstand, for example, burst pressures of up to 6 bar and / or temperatures of up to 1500°C.

[0017] In addition, the proposed thermal barrier structure allows for the grouping of at least two cells, preferably 6 to 18 cells, together, rather than insulating each cell using a thermal barrier element. This significantly reduces the weight of the battery stack.

[0018] The overall thickness of the thermal barrier component, i.e., its dimension along the lamination direction, can be 20 mm or less, and for deformables having an insulating layer provided on at least both sides of the core layer, it can be particularly 9 mm to 20 mm, preferably about 16 mm, for low weight and pack size while maintaining the desired thermal and mechanical performance. The thickness of a component having an insulating layer provided on only one side of the core layer can, of course, be even smaller. Here, thickness refers to the uncompressed state of the component.

[0019] According to the present invention, the core layer includes an inlet and is made of a rigid material, particularly a rigid foam material, preferably a structural foam material, such as a polymethacrylimide (PMI) based on Rohacell® or including, for example, an aluminum honeycomb structure. In this way, the inlet is lightweight and is suitable for carrying the shear load generated during thermal runaway. In particular, the foam material or honeycomb structure can also provide a certain degree of heat insulation.

[0020] The inlet can include or consist of an inlet material having at least one of the properties listed in the following table, preferably some or even all of these properties.

[0021]

Table 1

[0022] The temperature given under "Thermal stability" refers to the temperature until the mass loss does not exceed 20% or more when the material is heated at 20 °C / min in nitrogen.

[0023] In particular, the inlet material can have a shear strength of 0.5 MPa to 15 MPa and a density of 10 kg / m 3 to 500 kg / m 3 and preferably a shear strength of 1.2 MPa to 7 MPa and a density of 50 kg / m 3 to 300 kg / m 3 of density.

[0024] The frame element is provided to circumferentially surround the inlet of the core layer in order to protect the edge of the inlet from high temperature and / or flames.

[0025] The frame element can include or consist of a frame material having at least one of the properties listed in the following table, preferably some or all of these properties.

[0026] For example, the frame elements may include or consist of flame-retardant materials, particularly flame-retardant glass fiber reinforced polymer (GFRP) materials, such as FR4 or FR5NEMA, or polymers such as PEEK or polyimide.

[0027] Regarding manufacturing techniques, frame elements can be produced, for example, by waterjet cutting, injection molding, pressing, or punching.

[0028] [Table 2]

[0029] The frame elements and entrances can be attached to one another, preferably together with any other components of the core layer, using co-curing, and especially with film adhesive, as described below.

[0030] In this application, terms such as circumferential direction or axial direction preferably refer to the stacking direction of the stack as the axial direction.

[0031] Therefore, frame elements surrounding the entrance in a circumferential direction mean that the frame elements cover their surface portions of the entrance, having surface normals that are substantially perpendicular to the stacking direction.

[0032] To protect the core layer from high temperatures, at least one insulating layer can be placed on at least one side of the core layer. Preferably, at least two insulating layers are provided, one of which is placed on a first side of the core layer and the other on a second side of the core layer opposite to the first side, so that the two insulating layers sandwich the core layer.

[0033] Alternatively, or in addition, a corrosion barrier layer may be placed on at least one side of the core layer, particularly in addition to or covering the insulating layer(s), to protect the component from high-speed particles and gases, as described in more detail below.

[0034] The overall thickness of the core layer, i.e., its dimension along the lamination direction, can be less than 1 cm, preferably 3 mm to 5 mm, more preferably about 4 mm, for low weight and pack size while maintaining the desired thermal and mechanical performance.

[0035] It should be noted that the thermal barrier layer(s) and / or corrosion barrier layer(s) may be attached to each other and / or to the core layer, for example, by double-sided adhesive tape, or they may be provided as floating layers held in place by compression within the battery assembly.

[0036] In certain examples, a thermal barrier component includes an insulating layer on only one side of the core layer. This component can be used as a compression plate in a battery stack. Preferably, the outermost insulating layer of such a component is covered by a corrosion barrier layer, as described below.

[0037] The insulating layer may include aerogel, particularly silica aerogel. More specifically, the insulating layer may include a blanket in which silica aerogel is incorporated into nonwoven fabric fibers. Preferably, the insulating layer is compressible.

[0038] Preferably, an insulating layer containing silica aerogel has the technical effect of insulating structural components from intense heat release during thermal runaway and adjacent battery modules / cells, and preventing thermal runaway from propagating to adjacent battery modules. In addition, the insulating layer, particularly the silica aerogel layer, is advantageous because it provides cell compression to the battery cell, preferably the pouch cell.

[0039] It should be noted that, as used in this application, the term "layer" includes configurations in which a given layer comprises several sublayers.

[0040] In particular, the insulation layer may include 1 to 4 sublayers, especially 3 sublayers, each sublayer having a thickness of, for example, 1 to 3 mm, especially about 2 mm.

[0041] The overall insulation layer on one side or each side of the core layer can have a thickness of 3mm to 8mm, preferably 4mm to 6mm, and especially about 5mm, in an uncompressed state.

[0042] The thermal insulation layer may include or consist of thermal insulation materials having at least one, preferably some or all, of the properties listed in the table below.

[0043] [Table 3]

[0044] It should be noted that, as used herein, the term compressive stiffness refers to the slope of the compressive stress-to-strain curve measured at 40%.

[0045] According to a particular embodiment, the component further includes a plurality of studs or inserts distributed around the circumference of a frame element, each stud or insert being partially embedded within the frame element and partially protruding therefrom, particularly in an outward direction perpendicular to the stacking direction.

[0046] Studs or inserts held in place by frame elements can be used, for example, as fastening elements for fastening thermal barrier components to the housing wall of a battery assembly. For stability, the studs or inserts may contain or be made of metallic material, particularly titanium.

[0047] To provide primary bending and tensile strength, the core layer may further include two cover panels made from, for example, carbon fiber reinforced polymer (CFRP) material, particularly from woven epoxy CFRP ply, so that both the inlet and frame elements of the core layer are positioned between the two cover panels, and the core layer has a sandwich structure.

[0048] The entrance, frame elements, and studs can be attached to the core layer cover panel using a film adhesive, for example, by co-curing.

[0049] To withstand the high-speed gases and flying particles propelled by the high pressure generated during thermal runaway, the stack may further include at least one corrosion barrier layer forming the outermost layer of the stack, preferably two corrosion barrier layers forming the outermost layer on opposing sides of the stack. The corrosion barrier layer(s) may include or consist of fiber-reinforced polymers, particularly CFRP materials, more specifically phenolic CFRP materials.

[0050] The corrosion barrier layer may include or consist of corrosion barrier materials having at least one of the properties listed in the table below, preferably some or all of these properties.

[0051] [Table 4]

[0052] The corrosion barrier layer can have a thickness of, for example, 0.4 mm to 1.5 mm.

[0053] The disclosed layer stacking provides the best compromise between different requirements for thermal barrier components, which include lightweight design, compressibility to account for and / or prevent / reduce cell expansion, rigidity, thermal insulation, and heat resistance.

[0054] To facilitate assembly, the stack can be symmetrical with respect to the intermediate plane passing through the core layer, and as a result, the thermal barrier components can be installed in at least two different orientations.

[0055] According to a particular embodiment of the present invention, the frame element may include a closed boundary section and at least one inner bridge section connecting opposing sides of the boundary section, and the entrance may include at least two entrance portions separated by the bridge section. The bridge section can increase the resistance of the thermal barrier component to different mechanical loads, for example, by increasing the bending or torsional stiffness of the component.

[0056] To more securely hold the stud or insert in place, at least one bridge section of the frame element can connect two opposing anchor portions of the frame element, each anchor portion having one of the studs or inserts embedded therein.

[0057] Each stud may have a retaining projection that prevents the stud from being pulled out of the frame element. The stud may be, for example, T-shaped, with the upper horizontal bar of the T-shape forming the retaining projection. A threaded portion may be formed at the distal end of the stud.

[0058] To electrically connect battery cells adjacent to a thermal barrier component and enable high-voltage through-connections between adjacent modules, the thermal barrier component may include a connector plate and an electrically insulated connector plate holder, the connector plate holder having a mounting surface for the connector on a first side of the connector plate holder and connecting to the edge region of the layer stack on a second side of the connector plate holder opposite to the first side.

[0059] For example, a connector plate holder may include a mounting groove on a second side surface of the connector plate holder, and the edge region of the core layer of the layer stack can be inserted into the mounting groove to attach the connector plate holder.

[0060] For better electrical insulation, woven fiberglass electrical insulators can be provided on or wrapped around all electrical conductive components of the thermal barrier component adjacent to the connector plate, particularly all CFRP components adjacent to the connector plate.

[0061] In this context, it should be noted that corrosion barrier layers should be considered to form the outermost layer of the stack, insofar as they form the outermost surface over at least 50%, preferably at least 80% or 90%, of the entire surface of the stack.

[0062] According to certain embodiments, at least one of the studs or inserts may extend through a hole provided in the connector plate holder, which also helps to properly position the connector plate during assembly.

[0063] Protection for a battery assembly is also claimed, including a housing and at least one battery stack housed within the housing, each battery stack comprising at least one thermal barrier component, in particular multiple thermal barrier components, and at least one battery module, preferably several such battery modules, having at least one battery cell, wherein the battery modules or modules and the thermal barrier components or components are stacked alternately, and the thermal barrier components or components are fixedly mounted to the housing.

[0064] Preferably, plate-shaped thermal barrier components(s) are fixedly mounted to the circumferential walls of the housing, particularly the stack housing, so that these barrier components become part of the assembly's mechanical load-bearing structure, defining compartments for the battery modules(s), regardless of the internal structure of the thermal barrier components. Therefore, it is conceivable that protection for such battery assemblies may be claimed even if the thermal barrier components do not conform to the invention as described above. Nevertheless, according to certain embodiments, the thermal barrier components(s) are thermal barrier components(s) according to the present invention, as described above.

[0065] The circumferential or side walls of the housing, to which the thermal barrier components are attached, are used for storage and sealing, as well as for supporting stack compression loads.

[0066] As described above, each battery module includes at least one battery cell, preferably multiple stacked battery cells, in particular pouch cells.

[0067] Preferably, one or more thermal barrier components of the stack are attached to the housing using studs or inserts that are provided on or integrated with one or more thermal barrier components as described above, or using separate fasteners that connect the housing to one or more thermal barrier components. These fasteners can be inserted, for example, from the outside through the walls of the housing into the thermal barrier component(s).

[0068] In this way, the thermal barrier component is stably fixed within the housing, supporting the cell stack and also providing stability and rigidity to the assembly, while preventing or reducing the propagation of a thermal runway from one battery module to another.

[0069] For completeness, it should be noted that each battery module preferably includes several stacked battery cells, for example, six battery cells. However, this should not preclude configurations in which the battery module consists of a single battery cell. Furthermore, the battery assembly according to the present invention may include only several battery stacks or only a single battery stack.

[0070] According to certain embodiments, the stack may include only one battery module disposed between two thermal barrier components according to the present invention. These thermal barrier components are used as compression plates and preferably have thermal insulation and a corrosion barrier layer provided on only one side of the core layer, optionally.

[0071] According to another specific embodiment, the stack may include only one thermal barrier component according to the present invention, disposed between two battery modules, the thermal barrier component including thermal insulation and optionally a corrosion barrier layer provided on both sides of the core layer.

[0072] However, in many cases, the stack will include multiple thermal barrier components according to the present invention and multiple battery modules stacked alternately.

[0073] Mechanical cell requirements are a key factor for the conceptual architecture of the design; that is, cells must be compressed for optimal and safe operation. Furthermore, cells change their thickness due to changes in charge state and aging effects. Specifically, the following compression conditions must be met: When the cell is at its minimum thickness (=initial assembly condition), it must be compressed to a minimum of 6 psi, and when the cell is at its maximum thickness, the maximum pressure on the cell must be less than 60 psi.

[0074] To meet both requirements, a foam pad with nonlinear rigid behavior (between cells) and a compressible thermal insulation layer (on the thermal barrier component) can be used.

[0075] Therefore, according to certain embodiments, the foam pad can also be placed between adjacent battery cells in a battery module or multiple modules, preferably between thermal barrier components(s) and the nearest adjacent battery cells(s). The material of the foam pad can be, for example, a urethane elastomer foam.

[0076] Foam pads can be used, in particular, due to their nonlinear stiffness behavior, which will be described in more detail below with respect to Figure 7. Compared with conventional elastic materials such as rubber, using foam pads allows for the absorption of changes in cell thickness due to expansion, using thinner compression pads, while still providing sufficient initial compression.

[0077] In particular, the height of the battery module, the height or thickness of the foam pad, and the height or thickness of the insulation layer of the thermal barrier component sandwiching the battery module can be selected so that the minimum desired pressure limit is reliably achieved in the initial state for the battery module, and the expected cell expansion can be absorbed by additional deformation of the insulation layer and foam pad so that the pressure inside the module does not exceed the maximum desired pressure limit.

[0078] The foam pad may include or consist of foam pad materials having at least one, preferably some, or even all of, of the properties listed in the table below.

[0079] [Table 5]

[0080] According to one aspect of the present invention, as described above, the process for manufacturing a thermal barrier component according to the present invention is: The steps include forming the core layer and The process includes the steps of: placing at least one thermal insulation layer on at least one surface of the core layer to form a stack of layers; and / or placing at least one corrosion barrier layer on at least one surface of the core layer. The step of forming the core layer includes providing an inlet, which includes a rigid material, preferably a rigid foam material, and frame elements that surround the inlet in a circumferential direction, and preferably co-curing the inlet and frame elements using a film adhesive.

[0081] In certain examples, the two insulation layers are either placed on both sides of the core layer or attached to both sides of the core layer.

[0082] Preferably, the insulation layer is placed on the outer side surface of the core layer, and the corrosion barrier layer is placed on the outer side surface of the insulation layer.

[0083] If the core layer includes additional components such as studs or cover panels as described above, these additional components are preferably co-cured together with the entrance and frame elements, particularly using a film adhesive.

[0084] For example, the insulation layer(s) can be attached to the core layer using double-sided tape, the corrosion barrier layer(s) can be attached to the insulation layer(s) (if provided) or the core layer, or the insulation layer(s) and / or corrosion barrier layer(s) can be provided as a "floating layer" as described above.

[0085] Furthermore, protection was also claimed for the process for manufacturing the battery assembly, and this process is A step of providing at least one thermal barrier component, preferably several thermal barrier components, wherein the step of providing at least one thermal barrier component preferably includes a process for manufacturing the thermal barrier component according to the present invention as described above. A step of providing at least one battery module, preferably a plurality of battery modules, wherein each battery module includes at least one battery cell, preferably a plurality of stacked battery cells, The steps include stacking thermal barrier components (multiple) and battery modules (multiple) alternately to form a battery stack, Preferably, the steps include compressing the battery stack to a predetermined stack height, and housing the compressed battery stack within the housing. The process includes the step of attaching a thermal barrier component or component of the battery stack to the housing.

[0086] If the thermal barrier component does not have an integrated stud or insert, a suitable fastener can be inserted into the thermal barrier component from the outside through the housing.

[0087] It should be noted that the steps of housing the compressed battery stack and attaching the stack's thermal barrier components to the housing do not need to be performed in this order and can be repeated. In particular, the side walls or circumferential walls can be attached to the thermal barrier components separately, and this step can be part of the process of assembling the housing around the battery stack.

[0088] The present invention will be described in more detail below with reference to specific embodiments of the invention illustrated in the accompanying drawings. [Brief explanation of the drawing]

[0089] [Figure 1] This is a perspective view of a thermal barrier component according to a first embodiment of the present invention. [Figure 2] Figure 1 is an enlarged cross-sectional view of the front end region of the part, cut out as a cross-sectional plane along the xz plane. [Figure 3] This is a perspective view of a portion of the part shown in Figure 1, which does not have a corrosion barrier layer or an insulating layer. [Figure 4] Sections a) to c) illustrate how the thermal barrier components and battery modules are assembled into a battery stack, and how several battery stacks are assembled to form a battery assembly according to one embodiment of the present invention. [Figure 5] Figures a) to c) show schematic diagrams illustrating several steps in a process for manufacturing a battery assembly according to a further embodiment of the present invention. [Figure 6] Figures a) and b) show a portion of the battery stack of a battery assembly according to one embodiment of the present invention in its initial state and after cell expansion. [Figure 7] This figure shows the compressive pressure as a function of compressive strain for exemplary rubber and foam materials. [Figure 8] This figure visualizes the compression pressure within the battery module of a battery assembly according to one embodiment of the present invention, as a function of cell thickness. [Modes for carrying out the invention]

[0090] To improve readability, please note that if a figure contains several identical features, only a selected single or several of these identical features will have reference numerals. Furthermore, not all features in each figure have reference numerals; only those necessary or useful for illustrating each figure are provided.

[0091] Corresponding or identical features in different embodiments are indicated by the same reference numerals. Additional embodiments are described primarily insofar as they differ from the first embodiment. Otherwise, the description of the first embodiment is referred to.

[0092] As shown in Figure 1, a thermal barrier component 10 according to one embodiment of the present invention comprises a stack of layers 11 including a core layer 12, two thermal insulation layers 14 disposed on opposing sides of the core layer 12, and two corrosion barrier layers 16 forming the outermost layer of the stack 11, the layers being stacked in a stacking direction S that coincides with the z-direction in the coordinate system, as shown in Figure 1.

[0093] Overall, the component 10 is plate-shaped, and in a top view along the stacking direction S, layers 12, 14, and 16 are all roughly rectangular, with small notches 12c1, 14c1, and 16c1 at the four corners for accommodating corner sealants provided in the battery assembly (not shown), and large notches 12c2, 14c2, and 16c2 at the front end where the connector plate 39 is provided on the connector plate holder 26.

[0094] Several studs 22 are distributed around the circumference of the core layer 12, protruding outward in a direction perpendicular to the stacking direction S. As will be described later, the studs 22 serve to fix the position of the thermal barrier component 10 within the battery assembly.

[0095] As shown in the cross-sectional view of Figure 2, the thermal barrier component 10 is preferably symmetric with respect to an intermediate plane M passing through the core layer 12, and the intermediate plane M coincides with the xy plane in the coordinate system of Figure 1.

[0096] The core layer 12 includes an inlet 18, a frame element 20 surrounding the inlet 18 in a circumferential direction (see also Figure 3), and two cover panels 24 that sandwich both the inlet 18 and the frame element 20.

[0097] To accommodate the shear loads generated during thermal runaway while maintaining a lightweight design, the inlet 18 preferably contains or consists of a rigid foam material, preferably a structural foam material, more preferably a polymethacrylimide (PMI) based material such as Rohacell® WF200. As another lightweight, even rigid and stable alternative, an aluminum honeycomb structure can be used for the inlet.

[0098] The frame element 20 can be made from flame-retardant fiber-reinforced polymers, particularly GFRP, such as FR4 or FR5NEMA, or from polymers such as PEEK or polyimide by techniques such as waterjet cutting, injection molding, pressing, or punching.

[0099] The primary purpose of the frame element 20 is to seal the foam inlet 18 from high temperatures and / or flames, and to hold the studs 22 in place. Furthermore, it can help increase the overall rigidity of the component 10 and / or provide a sealing area for a sealing element (not shown) provided between the heat barrier component 10 and the circumferential side wall of the stack housing.

[0100] To improve the bending and tension resistance of the core layer 12, the inlet 18 and frame element 20 are positioned between two cover panels 24, which are part of the core layer 12 and may include fiber-reinforced polymer, preferably woven epoxy CFRP ply.

[0101] Preferably, the studs 22 and core layer 12 are co-cured with a film adhesive, for example, polyester and / or a suitable epoxy resin, to bond the foam inlet 18, frame elements 20, and studs 22 to the cover panel 24 and / or its prepreg, while improving production time and cost. The thickness of the core layer 12 can be about 5 mm.

[0102] In this example, each insulation layer 14 includes several sublayers, for example, three sublayers, each sublayer containing silica aerogel which can be incorporated into a nonwoven fiber material in particular. The uncompressed thickness of each sublayer can be, for example, 1 mm to 3 mm, preferably about 2 mm.

[0103] One of the main purposes of the thermal insulation layer 14 is to insulate the structural components of the thermal barrier, particularly the inlet of the core layer and adjacent battery cells or modules, from intense heat dissipation during thermal runaway, thereby preventing or reducing the propagation of the reaction. Furthermore, they can provide cell compression. For example, a cell compression load of approximately 60 psi can be achieved.

[0104] The corrosion barrier layer 16 protects the more delicate insulation layer 14 from high-speed gases and particles during thermal runaway and contains insulating dust during assembly. They must be wear-resistant and suitable for withstanding high temperatures up to 1500°C, for example, and may include, for example, a single layer of phenolic CFRP and a double layer of GFRP.

[0105] The electrically insulated connector plate holder 26 is attached to the stack 11, and the connector plate 39 is mounted on the first side of the connector plate holder 26.

[0106] More specifically, the edge region of the core layer 12 forming the front wall rib is inserted into a mounting groove 30 provided on the second side surface of the connector plate holder 26 opposite to the connector plate 39. The cell tabs of adjacent battery cells can be welded to the connector plate 39 to electrically connect adjacent battery modules separated by the heat barrier component 10.

[0107] One of the studs 22 extends through the hole 260 and cylindrical boss 27 of the connector plate holder 26. This stud 22 can be longer than the other studs to support the front circumferential wall of the stack housing, as shown in Figure 4. Overall, the length of the studs 22 can depend on the wall thickness of the stack housing.

[0108] In the longitudinal edge regions, particularly near the connector plate holder 26, all layers containing carbon fibers, such as the corrosion barrier layer 16 and the cover panel 24, may include an additional electrical insulator 29, such as woven glass fiber.

[0109] As shown in Figure 3, in which the thermal insulation layer 14 and corrosion barrier layer 16 are omitted, the frame element 20 is substantially rectangular in a top view along the lamination direction S and includes a closed boundary section 21 that forms the outer edge of the core layer 12, and several inner bridge sections 23 that connect the opposing sides of the boundary section 21, the bridge sections 23 separating several separate inlet portions 19 of the inlet 18, four inlet portions 19 in this example.

[0110] More specifically, the inner bridge section 23 in this example is straight, extends along the width direction of the component 10, and connects the anchor portions 25 on the opposite side of the frame element 20, each anchor portion 25 having one of the internally embedded studs 22. Note that the internal structure of the frame element 20, particularly the inner bridge section 23, is actually shown with dashed lines in Figure 3 because they are typically covered and hidden by the cover panel 24.

[0111] As shown in Figure 3, the stud 22 in this example has a flat T-shaped head 22h with a projection 27 that prevents the stud 22 from being pulled out of the frame element 20, and a cylindrical portion 22c that protrudes from the frame element 20. The distal end 22e of the cylindrical portion 22c can be threaded.

[0112] The studs 22 can be made from metallic materials, particularly titanium, and may have coatings for galvanic corrosion resistance depending on their location.

[0113] It should be noted that the sealing compression stop 17 can be formed within the co-cured assembly, particularly within the outer circumferential plane of the closed boundary section 21 of the frame element 20, for example, near the studs 22 on the side wall of the heat barrier component 10.

[0114] The overall incompressible thickness of the heat barrier component 10, i.e., its dimension along the lamination direction S, can be 20 mm or less, and in particular 9 mm to 20 mm, preferably about 16 mm.

[0115] The surface of the heat barrier component 10 is preferably flat, especially in the case of a pouch cell, in order to maintain uniform cell compression.

[0116] As illustrated in Figure 4, several battery cells, particularly pouch cells, are stacked to form a battery module 45 (see Figure 4a), and several (in this case, nine) battery modules 45 are stacked alternately with the thermal barrier component 10 according to the present invention as described above to form a battery stack 40, as shown in the partially exploded assembly view of Figure 4b. The stack 40 is housed in a housing 47, which includes an upper stack wall 49, a lower stack wall 51, and four circumferential stack walls 46. The circumferential stack walls 46 are positioned relative to the stack 40 by inserting studs 22 or inserts that project horizontally from the thermal barrier component 10 into corresponding mounting holes provided in the circumferential stack wall 40 and secured by connecting elements, preferably nuts 31 screwed into the distal ends of the studs 22. The upper wall 49 and the lower wall 51 can be fixed to the circumferential wall 46.

[0117] In this way, the thermal barrier component 10 can form a structural web within the vertical cell stack 40, resisting tension in various load cases such as thermal runaway, collision scenarios, flight loads, and cell compression, and preventing thermal runaway from propagating to adjacent modules while remaining lightweight.

[0118] Some of these stacks 40, in this example there are three stacks, can be grouped together to form a battery assembly 50 according to one embodiment of the present invention, as shown in Figure 4c, the assembly 50 further includes an exhaust manifold component 53 configured to vent gases generated within the stacks 40 of the battery assembly 50 in a controlled manner through an exhaust opening 55 during normal operation or in the event of thermal runaway.

[0119] These battery assemblies 50 can be used in electric aircraft, particularly eVTOL aircraft. In this case, the assembly can be positioned, for example, along the side wall of the aircraft, so that exhaust gases can be discharged from the aircraft through a suitable outlet within the side wall.

[0120] Figure 5 illustrates several steps of a process for manufacturing a battery assembly according to further embodiments of the present invention, as shown in Figures a) to c).

[0121] Figure 5a) shows a stack 40 containing three battery modules 45, each battery module 45 containing five battery cells 60, with foam pads 62 provided between adjacent cells 60 of the module 45 to provide uniform cell compression. The number of modules and battery cells in the figure are selected for illustrative purposes only.

[0122] The battery module 45 is stacked alternately with the heat barrier component 10 according to the present invention.

[0123] Note that two different types of the heat barrier component 10, 10.1 and 10.2, are used.

[0124] Inside the stack 40, a first type 10.1 of thermal barrier component 10 is provided between adjacent battery modules 45, which has two thermal insulation layers 14 provided on both sides of the core layer 12 and two corrosion barrier layers 16 forming the outermost layer on the opposing sides of the thermal barrier component 10.

[0125] The end of the stack 40 is formed by a second type 10.2 of the thermal barrier component 10 according to the present invention, where only one thermal insulation layer 14 provided on its side surface of the core layer 12 faces the interior of the stack 40, and only one corrosion barrier layer 16 provided on its side surface of the thermal insulation layer 14 faces the interior of the stack 40.

[0126] In this embodiment, both types of thermal barrier components 10 differ from the thermal barrier component 10 according to the first embodiment in that they do not include any integrated studs or inserts.

[0127] After forming a battery stack 40 by alternately stacking battery modules 45 and thermal barrier components 10, the stack 40 is compressed to a predetermined stack height h, for example, as indicated by arrow F in Figure 5b).

[0128] Next, as shown in Figure 5c), to form the battery assembly 50, the compressed stack 40 is housed within the housing 47, and the thermal barrier components 10 are attached to the housing 47 by fasteners 65 that connect the side walls 46 of the housing 47 to the core layer 12 of the thermal barrier components 10, particularly to the frame elements of the core layer 12 which are not visible in Figure 5c. Each fastener 65 can be inserted from the outside through the side wall 46 of the housing into its respective thermal barrier component 10.

[0129] In the illustrated example, two outermost thermal barrier components 10 according to one embodiment of the present invention form the upper and lower walls of the housing 47, but of course, it is also possible to use separate conventional upper and / or lower walls for the housing 47 instead of, or in addition to, these outermost thermal barrier components 10, as shown in Figure 5c.

[0130] It should be noted that the heat barrier component 10 can be offset from the circumferential wall 46 by a given distance, for example, about 1 mm, to allow for the assembly and installation of a sealing component (not shown).

[0131] Finally, please note that Figure 5 is highly simplified and does not show any details regarding the electrical connections of the battery cell 60.

[0132] Figure 6 also shows, in a simplified form in Figure 6a), a portion of the battery stack of an initial battery assembly according to one embodiment of the present invention, the illustrated portion comprising two thermal barrier components 10 according to one embodiment of the present invention, sandwiching a battery module 45 having six battery cells 60 in the form of pouch cells alternately stacked with seven foam pads 62. In Figure a), the cell thickness t is at its minimum value tA.

[0133] During operation, when the battery cell 60 is repeatedly charged and discharged, the cell thickness t reaches its maximum value t. B As illustrated in Figure 6b), battery swelling may occur. When the thermal barrier component 10 is fixed and connected to the side wall of the housing (not shown), the module height hM remains unchanged, while the foam pad 62 and insulation layer 14 of the thermal barrier component 10 are compressed to accommodate the increased cell thickness.

[0134] Figure 7 illustrates the reason why it is preferable to use a foamed material instead of a conventional material such as rubber for the pads between adjacent battery cells. This is a diagram showing the compression pressure p as a function s of the compressive strain for an exemplary rubber material and an exemplary foamed material.

[0135] The curve for the foam is non-linear and has a significant flat region, and thus the available strain range Δ min for a given fixed pressure range between the minimum pressure p max and the maximum pressure p ε is much larger than that for the rubber material, as shown in Figure 7. Therefore, the change in cell thickness due to expansion can be absorbed by a thinner compression pad made of foam while still providing sufficient initial compression.

[0136] Figure 8 visualizes the compression pressure p in the battery module of the battery assembly according to an embodiment of the present invention corresponding to Figure 6 as a function of the cell thickness t, where the cell thickness t A corresponds to that in Figure 6a), and the cell thickness t B corresponds to that in Figure 6b).

[0137] As shown in Figure 8, the module height, as well as the materials and thicknesses of the foamed pad and the thermal insulation layer, are such that in its initial state, at the cell thickness t A the compression pressure within the module exceeds the desired minimum threshold value p min and even when the cells expand to their maximum thickness t B the compression pressure within the module is selected to still be below the desired maximum threshold value p max .

[0138] Overall, the thermal barrier component according to the present invention is lightweight and easy to integrate into the battery assembly, and can serve a dual purpose as a thermal barrier that prevents the propagation of thermal runaway and as a structural component for the battery assembly that increases the resistance to different mechanical loads.

Claims

1. A thermal barrier component (10) for a battery assembly (50), The heat barrier component (10) includes a stack of layers (11), The aforementioned stack (11) The core layer (12) and The core layer (12) comprises at least one heat insulating layer (14) and / or corrosion barrier layer (16) disposed on at least one side surface of the core layer (12), The core layer (12) An inlet (18) containing a rigid material, preferably a rigid foamed material, The entrance (18) includes a frame element (20) that surrounds it in the circumferential direction, Heat barrier component (10).

2. The frame element (20) further comprises a plurality of studs (22) distributed around its circumference, Each stud (22) is partially embedded within the frame element (20) and partially protrudes outward from the frame element (20). The heat barrier component (10) according to claim 1.

3. The stack (11) comprises at least two insulating layers (14), One of the aforementioned heat insulating layers (14) is placed on the first side surface of the core layer (12), and Another of the thermal insulation layers (14) is positioned on the second side of the core layer (12) opposite to the first side. The thermal barrier component according to claim 1 or 2.

4. The core layer (12) further comprises two cover panels (24) between which both the entrance (18) and the frame element (20) are disposed. A thermal barrier component (10) according to any one of the prior claims.

5. The stack (11) further comprises at least one corrosion barrier layer (16) forming the outermost layer of the stack (11), preferably two corrosion barrier layers (16) forming the outermost layer on opposing sides of the stack (11). A thermal barrier component (10) according to any one of the prior claims.

6. The stack (11) is symmetric with respect to an intermediate plane (M) passing through the core layer (12). A thermal barrier component (10) according to any one of the prior claims.

7. The frame element (20) is Closed boundary section (21), The boundary section (21) comprises at least one inner bridge section (23) connecting opposing sides, The inlet (18) comprises at least two inlet portions (19) separated by the bridge section (23), A thermal barrier component (10) according to any one of the prior claims.

8. Each of the studs (22) has a retaining projection (27) that prevents the stud (22) from being pulled out from the frame element (20). A thermal barrier component (10) according to any one of the prior claims.

9. Connector plate (39) and The electrical insulated connector plate holder (26) is further provided, The connector plate holder (26) The first side surface has a mounting surface (28) for the connector plate (39), and On the second side of the connector plate holder (26), opposite to the first side, is connected to the edge region of the layer stack (11), A thermal barrier component (10) according to any one of the prior claims.

10. The connector plate holder (26) further comprises a mounting groove (30) on the second side surface of the connector plate holder (26), The edge region of the core layer (12) of the stack (11) of the aforementioned layers is inserted into the mounting groove (30). The heat barrier component (10) according to claim 6.

11. The rigid material of the inlet (18) is, for example, polymethacrylimide (PMI) or a structural foam material based on an aluminum honeycomb structure. and / or, The frame element (20) comprises a polymer material, preferably a fiber-reinforced polymer material, and more particularly a glass fiber-reinforced polymer material. and / or, The cover panel (24) includes a carbon fiber reinforced polymer, particularly a woven carbon fiber reinforced polymer. and / or, The stud (22) contains a metal material, particularly titanium. A thermal barrier component (10) according to any one of the prior claims.

12. The aforementioned heat insulating layer (14) contains silica aerogel, particularly in the form of a blanket in which silica aerogel is incorporated into nonwoven fabric fibers. and / or The corrosion barrier layer (16) comprises a fiber-reinforced polymer, preferably a carbon fiber-reinforced polymer, and more particularly a phenolic carbon fiber-reinforced polymer. A thermal barrier component (10) according to any one of the prior claims.

13. The inlet (18), the frame element (20), and the stud (22) are attached to the cover panel (24) of the core layer (12) by co-curing them using a film adhesive. In particular, the thermal barrier component (10) according to claims 2 and 4, in combination with any of the other prior claims.

14. A battery assembly (50), Housing (47) and The housing (47) comprises at least one battery stack (40), Each battery stack (40) Preferably, at least one thermal barrier component (10) as described in any one of the prior claims, It comprises at least one battery module (45) having at least one battery cell (60), One or more battery modules (45) and one or more heat barrier components (10) are stacked alternately. The one or more heat barrier components (10) are fixedly attached to the housing (47). Battery assembly (50).

15. The one or more heat barrier components (10) of the stack (40) Using a stud (22) or insert provided on or integrated with one or more of the aforementioned heat barrier components (10), Using a separate fastener (65) to connect the housing (47) to the one or more heat barrier components (10), The housing (47) is attached to the above housing, The battery assembly (50) according to claim 14.

16. The foam pad is positioned between adjacent battery cells (60) of one or more battery modules (45). The battery assembly (50) according to claim 14 or 15.

17. A process for manufacturing a thermal barrier component (10) according to any one of claims 1 to 13, The steps include forming a core layer (12) and The process includes the step of placing at least one thermal insulation layer (14) and / or at least one corrosion barrier layer (16) on at least one surface of the core layer (12) in order to form a stack of layers (11), The step of forming the core layer (12) is, An entrance (18) is provided, comprising a rigid material and a frame element (20) that surrounds the entrance (18) in the circumferential direction. This includes co-curing the inlet (18) and the frame element (20), process.

18. A process for manufacturing a battery assembly according to any one of claims 14 to 16, A step of providing at least one thermal barrier component (10), preferably several thermal barrier components (10), wherein the step of providing the at least one thermal barrier component (10) preferably includes the process of claim 17. A step of providing at least one battery module (45), preferably a plurality of battery modules (45), wherein each battery module (45) comprises at least one battery cell (60), preferably a plurality of stacked battery cells (60), The steps include stacking one or more heat barrier components (10) and the one or more battery modules (45) alternately to form a battery stack (40), Preferably, the battery stack is compressed to a predetermined stack height (h), The steps include: housing the compressed battery stack (40) inside the housing (47); The step of attaching one or more heat barrier components (10) of the battery stack (40) to the housing (47) is included. process.

Images