Battery housing containing a battery device with multiple battery cells for electric aircraft

Abstract

The invention relates to a battery housing (10) for an electric aircraft (100), the battery housing (10) being configured to accommodate a battery device (20) having a plurality of battery cells (22), the battery housing (10) comprising at least one inner wall (30) and at least one outer wall (40), the inner wall (30) and the outer wall (40) together forming a battery volume (50) for holding the plurality of battery cells (22), characterized in that the at least one outer wall (40) comprises an outer side surface (42), wherein the outer side surface (42) has an aerodynamic shape for constituting a part of a fuselage (110) of the electric aircraft (100).

Description

[0001] The present invention relates to a battery housing for an electric aircraft that houses a battery device having multiple battery cells, a mounting method for mounting such a battery housing, and a battery assembly including a battery housing having battery devices.

[0002] As is well known, if an aircraft must be equipped with electric engines, a battery unit is required to store and supply electrical energy. In current concepts of electric aircraft, the battery unit consists of multiple battery cells that need to be housed in a battery casing. Furthermore, in current concepts, the battery casing is typically an internal battery casing to be placed inside the aircraft. This is particularly helpful in preventing any mechanical damage to the battery unit during critical phases of flight or landing, such as in an aircraft crash, for safety reasons.

[0003] Based on the current concept, one drawback is that the battery casing needs to be placed inside the aircraft, thus occupying a certain amount of internal space. Therefore, placing those battery casings inside reduces the flexibility of using the aircraft's internal space, thereby compressing cargo space and / or passenger space. Furthermore, such known casings are often very complex, leading to additional problems during manufacturing and installation, especially when placing the casing inside an electric aircraft. Finally, a further issue is the additional weight, which comes not only from the battery device itself but also from the material of the battery casing, as this material needs to provide safety protection and coverage for the battery device.

[0004] One object of the present invention is to at least partially solve the above-mentioned problems. Specifically, the object of the present invention is to provide a cost-effective and easily implemented solution for reducing the weight and / or volume of battery devices in electric aircraft.

[0005] The aforementioned objective is achieved by a battery casing having the features of claim 1, an mounting method having the features of claim 14, and a battery assembly having the features of claim 16. Any features described in the dependent claims may be freely combined with each other.

[0006] According to the present invention, a battery housing for an electric aircraft is provided, the battery housing being used to house a battery device having a plurality of battery cells. Such a battery housing includes at least one inner wall and at least one outer wall, the inner wall and the outer wall together forming a battery volume for holding the plurality of battery cells. The battery housing of the present invention is characterized in that at least one outer wall includes an outer surface, wherein the outer surface has an aerodynamic shape for forming part of the fuselage of the electric aircraft.

[0007] According to the present invention, the battery housing is a solution based on the current concept of electric aircraft. Therefore, there is a need to accommodate a battery device formed by multiple battery cells. To improve the safety and placement stability of the battery cells in the aircraft, and especially to provide a compression option for the multiple battery cells of the compressed battery device, such a battery volume may also be provided with cell compartments, each accommodating one or more of those multiple battery cells.

[0008] Compared to current solutions, according to the present invention, the battery casing now comprises at least two different types of outer walls. One type is considered to be an outer wall having the aerodynamic shape of the present invention for forming part of the fuselage. In other words, the outer wall thus has a dual function. The first function is to form the battery casing and close the battery volume for holding multiple battery cells. Additionally, the second function of the outer wall is to provide an aerodynamic shape and form at least a portion of the fuselage of the electric aircraft. As described later, the fuselage of an aircraft has an external aerodynamic shape that is essentially configured to form aerodynamic functions similar to a wing, or to reduce aerodynamic friction with the surrounding air, thereby improving the efficiency of the electric aircraft during flight operations.

[0009] According to the present invention, the type of aerodynamic shape formed by the outer surface of the outer wall of the battery casing is not important. At least due to the combination of two functions, the additional closing wall required in the current concept is no longer necessary in the battery casing of the present invention. Furthermore, the battery casing still includes an inner wall to close the battery volume together with the outer wall.

[0010] Compared to current solutions in the prior art, the dual function of the outer wall of this invention—serving to enclose the battery volume and to ultimately define and construct the aircraft fuselage—achieves a reduction in required installation space and weight. In the prior art, the outer portion of the fuselage requires space and weight, as does the outer wall of the battery housing. The combination of at least a portion of the fuselage with the outer wall of the battery volume eliminates at least a portion of this additional weight, thus providing additional free space. Furthermore, the accessibility of the battery housing is optimized due to the location of the outer wall as part of the aircraft fuselage. As described later, this beneficial accessibility can, for example, lead to a better and easier installation process, a better and easier inspection process, and / or even better and easier replacement of battery cells or the entire battery assembly.

[0011] Based on this invention, the aircraft still maintains a complete fuselage from the outside, relative to the necessary aerodynamic functions described above. Due to the functional combination of the invention, the fuselage at least partially forms and constitutes the battery housing according to the invention. In other words, the battery housing can be partially pre-installed, for example, consisting only of the inner wall and multiple battery cells, and then this semi-finished component is placed as part of the aircraft, thus having easier accessibility near the outside of the aircraft. The battery housing is then constructed and closed in such a way that the fuselage forms an outer wall including the outer surface. As can be seen from this specification, not only is the final aircraft optimized in terms of weight and complexity and through increased free space availability, but the installation steps of the battery device and the replacement methods that may be necessary are also optimized by using the invention.

[0012] According to the invention, the battery housing is characterized by an outer wall comprising a mounting interface for reversible mounting to an adjacent fuselage wall, reversibly mounting to an aircraft structural element, and / or reversibly mounting to at least one inner wall. The mounting interface thus includes reversible mounting functionality. In other words, the mounting interface provides removability for detachment from the respective adjacent fuselage wall, aircraft structural element, and / or inner wall. This particularly ensures optimized accessibility even when the aircraft is already in service. For example, after a certain number of flight cycles, the battery unit needs to be inspected and / or replaced with a new battery unit. The proposed concept is advantageous because it provides the necessary accessibility to the battery unit to improve the inspection and / or replacement of used battery units. In current solutions where the battery housing is located internally (i.e., the battery housing does not include at least a portion of the fuselage shell), complete or at least partial disassembly of the fuselage is required. According to the invention, the battery housing provides improved accessibility to the battery unit. Specifically, due to reversible installation, the mounting interface allows for reversible disassembly steps, thus providing improved access to the battery assembly and / or multiple battery cells. Of course, the mounting interface can also integrate electrical coupling systems and functions, ensuring an electrical connection is established when the battery is installed at the mounting interface. Disconnection (especially high-voltage disconnection) is automatically provided via electrical decoupling upon removal from the mounting interface.

[0013] Another advantage is that, according to the invention, the battery housing is characterized by a mounting interface including an opening passage that defines opening movement of the outer wall between a closed position and an open position. This must be understood as the mounting interface providing defined movement between two end positions (meaning an open position and a closed position). Therefore, the closed position is defined as providing an aerodynamic shape in a continuous neighborhood of adjacent fuselage components. It must be understood that, especially in the absence of any edges or additional friction surfaces, the aerodynamic shape of the fuselage is fully constituted by the outer wall of the battery housing in its closed position. The open position can be defined as the possibility of separation from the mounting interface and / or the direct accessibility of the battery cell and / or the battery assembly as a whole. This results in optimized and improved capabilities for inspecting the battery assembly and / or replacing the battery assembly from the battery housing.

[0014] According to the invention, the battery housing is characterized in that the mounting interface is detachable from the opposing mounting interface, at least in the open position, which provides another advantage. As mentioned above, in some cases, it may be necessary to inspect, replace, or at least remove the battery unit from the electric aircraft. This can be achieved easily and quickly through reversible removal from the opposing mounting interface in the open position. Specifically, in maintenance situations, the aircraft can provide an opening in the outer wall, meaning it can be moved to the open position. Once in the open position, the battery unit can be detached from the electric aircraft, specifically from the opposing mounting interface, by removing or separating the entire battery unit, still attached to the outer wall, from the opposing mounting interface. The detached battery unit, along with the outer wall, can then be placed on a separate workbench, for example, for detailed inspection or checking of the battery unit's functionality. Simultaneously, to increase the aircraft's flight hours, a separate and / or new battery unit, along with a new outer wall, can be attached to the opposing mounting interface, moved back to the closed position, and the aircraft is ready to fly again while the inspection procedures for the detached battery unit continue.

[0015] Another advantage is achieved if, according to the invention, the battery casing is characterized in that at least one outer wall includes at least one overpressure port leading to the battery volume, each overpressure port having a port closure that irreversibly opens in response to overpressure occurring in the battery volume. In some very rare situations, battery devices may experience electrical and / or chemical problems. Some of these problems can lead to so-called thermal runaway, in which the internal pressure of the battery device increases rapidly. From a safety perspective, it is necessary to avoid explosions caused by high overpressure inside the battery device. To address this safety issue, according to this embodiment of the invention, at least one overpressure port leading to the battery volume is provided. The overpressure port can automatically open due to overpressure inside the battery volume, and thus provides release of such overpressure. The overpressure port can, for example, be part of a valve system, specifically including a break line that automatically and irreversibly opens under overpressure inside the battery volume. The opening is an opening to the outside of the aircraft rather than the inside, meaning that the overpressure gas causing the overpressure is also released to the outside of the aircraft. Releasing to the outside of the aircraft further enhances the safety of this function. In terms of weight reduction and volume reduction, those overpressure ports can be embodied, for example, as rupture openings or rupture diaphragms. No channels or additional guiding elements are needed for the overpressure gas because those overpressure ports are directly part of the outer wall and therefore open directly to the outside of the aircraft.

[0016] According to the invention, the battery housing is characterized in that the port closure includes a hinge portion that allows the port closure to hinge from a sealed position of the sealed battery volume to a release position for releasing overpressurized gas from the battery volume. Such a hinge portion allows for defined movement of the port closure. A major advantage of this hinge portion is the fact that the port closure, after being opened, is not released but remains in a safe and defined release position. This prevents any particles, components, or even the entire port closure from being sucked into any fan or other engine parts of the aircraft, thus avoiding further mechanical damage. The hinge prevents such complete separation and therefore increases the safety and reliability of those engine parts of the aircraft.

[0017] Another advantage can be achieved if, according to the invention, the battery casing is characterized in that the port closure includes multiple break lines that cause the port closure to break into closure fragments having a harmless diameter that is innocuous to an aircraft fan. The harmless diameter is, for example, small enough to be considered harmless in terms of mechanical damage or destruction to the fan or blades of an aircraft engine. If any part or particle from an open port closure reaches a certain size, it can cause mechanical failures and problems when ingested into the fan and blades of an aircraft engine. Therefore, from a mechanical point of view, the harmless diameter can be defined according to the invention, meaning that particles with a harmless diameter or smaller are considered harmless in terms of the mechanical damage they cause to the fan of an aircraft engine. Those break lines can be defined as break lines in the form of fracture lines, or can be undefined break lines provided solely by the material of the components of the port closure itself. For example, the port closure can be provided by a porous material that automatically breaks into small, powdery fragments upon opening the port closure, which are automatically considered smaller than the harmless diameter in question.

[0018] According to the invention, the battery housing is characterized in that the port closure includes a retaining element for holding the port closure in place after it has left the sealed position. This can be achieved, for example, according to a hinge portion as further discussed above. Of course, a safety line or a bridge of fixing material can also be used to provide this retaining function. Furthermore, a hinge portion providing bending movement for the port closure portion can be considered as a retaining element for holding the port closure connected to the outer wall when it leaves the sealed position.

[0019] Another advantage is that, according to the invention, the battery housing is characterized by at least one inner wall and / or at least one outer wall comprising compartment walls separating the battery volume and cell compartments. As further discussed above, the battery volume can be divided into different cell compartments, particularly in a uniform manner. Those cell compartments are configured to hold multiple battery cells, and thus allow for further separation of the different battery cells of the battery assembly. Another advantage of using compartment walls is the fact that the battery cells can be compressed between the compartment walls, and therefore the required compression of the battery cells can be achieved through the existing internal compartment walls of the battery housing itself. This is further enhanced by the use of any overpressure ports, especially those in each of the compartment walls that include such overpressure ports leading to the outside.

[0020] According to the invention, the battery housing is characterized by a plurality of battery cells arranged inside the battery volume and at least partially covered by a stabilizing material, particularly stabilizing foam, which provides another advantage. In other words, after the installation steps of moving the battery cells and inserting them into the battery volume and / or into compartments within the battery volume, the remaining free space between the cells can be filled, for example, with stabilizing foam. Of course, other mechanical solutions can also be used, such as lightweight interface elements extending from one of the inner surfaces to the cells, to reduce movement and, in particular, to prevent any relative movement of the battery cells within the battery housing.

[0021] Another advantage is that, according to the invention, the battery housing is characterized in that at least one inner wall and / or at least one outer wall comprises structural elements for bearing structural loads from the fuselage of the electric aircraft. These structural elements are intended to bear loads and provide load paths for loads generated by the operation of the electric aircraft. These loads can be air loads, for example, during taxiing, landing, or takeoff, as well as land loads. Furthermore, providing load paths during flight operations means that any mechanical loads applied to the electric aircraft by movement in the air can be guided through these load paths via these structural elements. In other words, providing these additional structural elements provides additional functionality and thus reduces the need for individual structural elements within the aircraft. In other words, the battery housing can therefore be part of the load path within the electric aircraft's interior, thus increasing the optimization of the aircraft's internal weight and space utilization.

[0022] According to the invention, the battery casing is characterized in that at least one outer wall has an outer surface that forms a side of the aircraft fuselage. This provides another advantage. By placing the outer wall on the side of the fuselage, accessibility in terms of opening and obtaining access to the battery casing is further increased. Furthermore, the installation process during the production of such electric aircraft is optimized by positioning the outer surface on the side of the aircraft fuselage.

[0023] According to the invention, the battery casing is characterized in that at least one inner wall includes an inner surface having a geometric extension different from the outer surface of at least one outer wall. The difference in geometric extension shape means that the outer wall has an extension shape defined by the aerodynamic function provided by the outer surface. The inner surface does not need to provide aerodynamic function and therefore can be provided with a completely different geometric extension shape. Specifically, the inner surface can include a simple internal geometric extension shape, which reduces complexity and manufacturing costs.

[0024] Another aspect of the present invention provides a method for mounting an inventive battery casing and an electric aircraft according to the invention. This mounting method includes the following steps: - Multiple battery cells are placed in a battery volume to form a battery device. - Install the battery casing on the electric aircraft, forming at least part of the fuselage.

[0025] The method of the present invention uses the battery casing of the present invention and has the same advantages and optimizations as described in detail with respect to the battery casing of the present invention.

[0026] Another advantage is that, according to the invention, the installation method is characterized by the battery device being fully assembled and electrically connected to the electrical interface of the electric aircraft prior to the installation step. In other words, from an electrical perspective, pre-connection allows for easy and particularly safe installation on the electric aircraft. This can be achieved, for example, by a hinge function as described with respect to the battery housing of the invention.

[0027] Another aspect of the present invention is to provide a battery assembly comprising at least one battery casing of the present invention, wherein a battery device having a plurality of battery cells is housed within a battery volume. Therefore, the battery assembly of the present invention also provides the same advantages as described in detail with respect to the battery casing of the present invention.

[0028] Another aspect of the present invention is to provide an electric aircraft comprising at least one battery assembly according to the present invention. Therefore, the electric aircraft of the present invention also provides the same advantages as described in detail with respect to the battery casing of the present invention.

[0029] Other embodiments of the invention are described in detail relative to the schematically shown diagrams: Figure 1 A first embodiment of the battery casing of the present invention, Figure 2 Another embodiment of the battery casing of the present invention, Figure 3 Figure 2 In the embodiment, in the open position, Figure 4 Another embodiment of the battery casing of the present invention, in the open position, Figure 5 Another embodiment of the battery casing of the present invention, Figure 6 Figure 5 The embodiment is in the released position of the port closure. Figure 7 Another embodiment of the battery casing, wherein the port closure is in the released position, and Figure 8 Another embodiment of the battery casing of the present invention.

[0030] Figure 1An embodiment of the battery housing 10 of the present invention is depicted. It shows a side portion of the fuselage 110 of an electric aircraft 100. This side portion of the fuselage 110 forms a fuselage wall 112, which is partially formed by the outer surface 42 of the outer wall 40 of the battery housing 10. The battery housing 10 provides a battery volume 50 formed by the outer wall 40 and the inner wall 30. Figure 1 In one embodiment, the battery volume 50 is divided into three or more unit compartments 52 by a compartment wall 70. Each of those unit compartments 52 includes a plurality of battery cells 22 forming the battery device 20 according to the invention. Furthermore, it can be seen that the geometric extension shape of the outer surface 42 of the outer wall 40 is more complex than that of the inner wall 30 having the inner surface 32, because it needs to match the aerodynamic shape of the fuselage wall 112.

[0031] Figure 1 Another embodiment of the invention is depicted, which provides accessibility to a plurality of battery cells 22. An opening axis OA is provided using a hinged mounting interface 44. Figure 2 This shows the outer wall 40 in its closed position CP, while... Figure 3 The open position OP in the middle provides accessibility to multiple battery cells 22.

[0032] Figure 4 Display and Figure 2 and 3 Different solutions. In this embodiment, the entire battery housing 10 can be moved from the closed position CP to the open position OP, such as... Figure 4 As depicted in the diagram. Here, the battery housing 10, which includes the outer wall 40 and the inner wall 30, can be detached from the mounting interface 44, for example, and can be replaced by a new battery housing 10, for example.

[0033] Figure 5 An overvoltage safety solution is demonstrated. Here, a portion of the battery housing 10 is depicted as having a cell compartment 52 including an overvoltage port 60. Figure 5 In this configuration, the overpressure port 60 is closed by the port closure 62, thus providing a sealed position SP. If the pressure inside the unit compartment 52 increases beyond a certain threshold, the port closure 62 moves to the release position RP, for example... Figure 6 As depicted in the diagram. Since this is part of the outer wall 40, the overpressure can be released as the gas enters the air outside the electric aircraft, and no additional guide channel for the overpressure gas is required.

[0034] exist Figure 7 In the middle, the port closure 62 further provides a retaining element 64, the retaining element being as follows: Figure 6This refers to a portion of the hinge section 63 disclosed herein. In both cases, the result is that the port closure 62 remains in the released position RP while connected to the outer wall 40, thus preventing damage to any fans of the electric aircraft 100's engine.

[0035] Figure 8 Another solution for the battery housing 10 is shown. In this case, the cell compartment 52 is filled with a stabilizing material 80, for example, in the form of a stabilizing foam. In this embodiment, the structural element 90 also provides the possibility of bearing loads from the outer wall 40 and thus from the fuselage 110 of the aircraft 100. Furthermore, since the battery cell 20 is implemented and housed within the battery volume 50 in this figure, this can also be considered as the battery assembly 200 according to the invention.

[0036] The above discussion of the embodiments describes the invention by way of example only.

[0037] Figure Labels 10 Battery casing 20 Battery Device 22 battery cells 30 Inner wall 32 Inner surface 34 Opposite mounting interface 40 outer wall 42 Outer surface 44 Installation Interface 50 battery capacity Unit 52 60 Overvoltage Port 62-port closure 63. Hinge section 64 Holding element 70 compartment wall 80 Stabilized Materials 90 Structural Components 100 Electric Aircraft 110 fuselage 112 Fuselage Wall 200 battery packs OA Open axis CP closing position OP Open Location SP sealing position RP release location

Claims

1. A battery housing (10) for an electric aircraft (100), the battery housing (10) for accommodating a battery device (20) having a plurality of battery cells (22), the battery housing (10) comprising at least one inner wall (30) and at least one outer wall (40), the inner wall (30) and the outer wall (40) together forming a battery volume (50) for holding the plurality of battery cells (22), characterized in that, The at least one outer wall (40) includes an outer surface (42) having an aerodynamic shape for forming part of the fuselage (110) of the electric aircraft (100).

2. The battery casing (10) according to claim 1, characterized in that, The outer wall (40) includes a mounting interface (44) for reversibly mounting on an adjacent fuselage wall (112), reversibly mounting on an aircraft structural element, and / or reversibly mounting on at least one inner wall (30).

3. The battery casing (10) according to claim 2, characterized in that, The mounting interface (44) includes an opening axis (OA) that defines the opening movement of the outer wall (40) between a closed position (CP) and an open position (OP).

4. The battery casing (10) according to claim 3, characterized in that, The mounting interface (44) can be separated from the opposing mounting interface (34) at least in the open position (OP).

5. The battery casing (10) according to any one of the preceding claims, characterized in that, The at least one outer wall (40) includes at least one overpressure port (60) leading to the battery volume (50), each overpressure port (60) having a port closure (62) that is irreversibly open in response to an overpressure in the battery volume (50).

6. The battery casing (10) according to claim 5, characterized in that, The port closure (62) includes a hinge portion (63) that allows the port closure (62) to move from a sealed position (SP) that seals the battery volume (50) to a release position (RP) that releases overpressure gas from the battery volume (50).

7. The battery casing (10) according to any one of claims 5 or 6, characterized in that, The port closure (62) includes multiple break lines that cause the port closure (62) to break into closure fragments having a harmless diameter that is harmless to the aircraft's fan.

8. The battery casing (10) according to any one of claims 5 to 7, characterized in that, The port closure (62) includes a retaining element (64) for retaining the port closure (62) after it has left the sealed position (SP).

9. The battery casing (10) according to any one of the preceding claims, characterized in that, The at least one inner wall (30) and / or the at least one outer wall (40) includes the compartment wall (70) of the battery volume (50) in the partition unit compartment (52).

10. The battery casing (10) according to any one of the preceding claims, characterized in that, The plurality of battery cells (22) are arranged inside the battery volume (50) and are at least partially covered by a stabilizing material (80), the stabilizing material (80) in particular including stabilizing foam.

11. The battery casing (10) according to any one of the preceding claims, characterized in that, The at least one inner wall (30) and / or the at least one outer wall (40) include a structural element (90) for bearing structural loads from the fuselage (110) of the electric aircraft (100).

12. The battery casing (10) according to any one of the preceding claims, characterized in that, The at least one outer wall (40) has the outer surface (42), which forms the side of the fuselage (110) of the aircraft (100).

13. The battery casing (10) according to any one of the preceding claims, characterized in that, The at least one inner wall (30) includes an inner surface (32) having a different geometric extension shape than the outer surface (42) of the at least one outer wall (40).

14. A method for mounting a battery housing (10) having the features of any one of claims 1 to 13 at an electric aircraft (100), comprising the following steps: - Multiple battery cells (22) are placed in the battery volume (50) to form the battery device (20). - The battery housing (10) is installed on the electric aircraft (100) to form at least a part of the fuselage (110).

15. The installation method according to claim 14, characterized in that, Prior to the installation step, the battery device (50) is fully assembled and electrically connected to the electrical interface of the electric aircraft (100).

16. A battery assembly (200) comprising at least one battery housing (100) having the features of any one of claims 1 to 13, wherein a battery device (20) having a plurality of battery cells (22) is housed within the battery volume (40).

17. An electric aircraft comprising at least one battery assembly (200) having the features of claim 16.

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