Battery assemblies, particularly for use in electric VTOL aircraft.

Abstract

The present invention relates particularly to a battery assembly (42) for use in an electric propulsion VTOL aircraft, the battery assembly (42) comprising a base plate assembly (44) and at least one battery stack assembly (20), each battery stack assembly (20) comprising a plurality of battery cells (12) stacked on the base plate assembly (20) along a stacking direction (S) and thus forming a battery cell stack (10) and electrically connected in parallel or series, and a housing (22) surrounding the battery cells (12) on all four sides, each battery stack assembly (20) comprising at least one barrier plate member (16) inserted between adjacent battery cells (12) and connected to the housing (22) to form at least two separate sealed modules (14) of the battery cells (12) within the corresponding battery stack assembly (20).

Description

Technical Field

[0001] The present invention relates to a battery assembly for use particularly in an electric propulsion VTOL aircraft, an electric propulsion VTOL aircraft comprising at least one such battery assembly, and a method for assembling such a battery assembly.

[0002] For example, for certain new use cases, particularly electric propulsion aircraft having a vertical take-off and landing (VTOL) function, new requirements are being posed for battery assemblies or battery modules that function as a power source for the corresponding devices. In particular, on the one hand, high capacity and maximum output characteristics are desired, and on the other hand, such battery assemblies must be absolutely safe and highly reliable during their operation. In particular, potential thermal runaway events must be limited to the smallest possible volume within such battery assemblies in order to avoid their catastrophic failure. For example, compared to current high-performance battery assemblies installed in electric vehicles, a thermal runaway event during the flight operation of an electric propulsion aircraft can be catastrophic if not contained in an appropriate manner, because in order to evacuate the passengers, the aircraft must first continue its flight and the pilot must identify a safe landing site and perform an emergency landing, which requires a certain amount of time. [[ID=*11]]

[0003] Typical battery assemblies proposed for such use cases include one or more battery cell stacks, which in turn consist of a plurality of battery cells that are individually wired and managed. Such battery assemblies must meet certain requirements regarding their mechanical characteristics, meet performance requirements, and minimize not only the heat conduction within the battery assembly but also the heat conduction from the inside to their surroundings in order to enable safe and reliable handling of such battery modules and their integration into the corresponding aircraft.

[0004] Therefore, an object of the present invention is to provide an improved battery assembly, particularly for use in electric propulsion VTOL aircraft, that exhibits suitable behavior in the event of a thermal runaway, as well as improved mechanical and thermal properties.

[0005] For this purpose, the battery assembly according to the present invention comprises a base plate assembly and at least one battery stack assembly, each battery stack assembly including a plurality of battery cells stacked on the base plate assembly along the stacking direction and thus forming a battery cell stack and electrically connected in parallel or in series, and a housing surrounding the battery cells on all four sides, each battery stack assembly including at least one barrier plate member inserted between adjacent battery cells and fixed to the housing to form at least two separate sealed modules of at least one battery cell, respectively, within the corresponding battery stack assembly.

[0006] Therefore, by introducing and inserting barrier plate members inside the battery stack assembly, each surrounded by a housing, a sealed module of fewer battery cells or even a single battery cell can be formed. Thus, in the event of a thermal runaway event, the adverse effects of these events can be contained within the corresponding sealed module without spreading to the rest of the battery stack assembly. In other words, a potential thermal runaway event can be contained, and its propagation to adjacent modules can be prevented.

[0007] In addition, according to the present invention, the barrier plate member not only functions as a means of thermal isolation between different sealed modules of at least one battery stack assembly, but by fixing the barrier plate member to the housing of the battery stack assembly, the barrier plate member also contributes to the overall mechanical rigidity and stiffness of the battery assembly and is therefore also referred to as a structural thermal barrier. Thus, the barrier plate member can not only provide thermal isolation of potential thermal runaway events, but rather provide mechanical isolation by providing mechanical reinforcement to the stack, because even if battery cells in a particular sealed module of the battery stack assembly are burned out and therefore lose their mechanical integrity, the corresponding barrier plate member that restricts the sealed module above it will maintain its structural integrity and support the cells of the adjacent module, thus making it possible to still firmly support the sealed battery cell module above the module where thermal runaway occurred.

[0008] It should be noted that the base plate assembly of the battery assembly according to the present invention does not have to be a monolithic plate member, but can be arranged to have an internal space for housing certain components, which will be discussed in detail below. Therefore, even when the base plate assembly functions as a structural member that must be able to support the weight of the components stacked on it, the base plate assembly may nevertheless include a plurality of parts, such as an upper structural cover on which the battery stack assembly is placed, and a lower sheet member for sealing the internal space.

[0009] According to the present invention, at least one battery stack assembly of a battery assembly may further include an upper compression plate and / or a bottom compression plate that compress the cell stack along the stacking direction. In this, the compression plate helps to transmit the corresponding compressive force all the way to the housing.

[0010] Furthermore, in the battery assembly according to the present invention, at least one battery stack assembly may further comprise a cooling device that extends inside and / or outside the housing, and through and / or into each individual battery cell module, preferably in the form of a continuous series of individual connected cooling plates for each battery cell module, or in the form of a continuous cooling plate across the battery stack. In particular, the cooling device may be connected to the individual battery cells using thermal pads and / or thermal paste to ensure optimal heat transfer. When such a cooling device is provided inside the housing of the corresponding battery stack assembly, it is clear that suitable measures must be taken to seal the corresponding module using at least one barrier plate member. For example, the barrier plate member may have a suitable notch, and the components of the cooling device may extend using suitable sealing means arranged around the notch. It is further noted that in embodiments where the cooling device extends outside the housing, heat conduction on the device in the event of a thermal runaway event can be prevented to an even greater extent, while when the cooling device extends inside the housing, higher cooling efficiency can be achieved.

[0011] In addition, in the battery assembly according to the present invention, at least one battery stack assembly may further include an electronic device located inside the housing and extending into each battery cell module, the electronic device preferably including at least one of a temperature sensor and a voltage sensor, for example, one temperature sensor per battery cell module and / or one voltage sensor per battery cell. The electronic device may be formed from, for example, a flexible circuit board located inside the corresponding battery stack assembly, or may include such a device. In a similar manner to that discussed for cooling devices, the electronic device must also be installed in such a manner that the multiple battery cell modules can still be sealed to each other, and that the barrier plate members used for this task can still be securely connected to the battery stack assembly housing. By installing the temperature sensor and / or voltage sensor inside the barrier stack assembly, it is possible to detect the operating parameters of the corresponding battery cells in real time to ensure their intended operation. Furthermore, if such sensors are located in direct proximity to the battery cells, any potential thermal runaway events can also be detected immediately. The data output by the sensor may be transferred to the central electronic control component of the corresponding battery assembly and processed in any preferred manner.

[0012] In the event of a thermal runaway incident, to allow for the release of gas and possible other debris and to reduce thermal stress on the corresponding battery stack assembly, the housing of the battery stack assembly may include through-holes with overpressure vents for each battery cell module, preferably all located on the same side of the housing. Therefore, if a thermal runaway incident occurs in one of the sealed battery cell modules, the resulting overpressure will cause the corresponding overpressure vent to rupture, and the gas can escape from the battery stack assembly housing through the respective through-holes in a controlled manner.

[0013] For this purpose, and to safely keep the runaway thermal gases away from the battery assembly while reducing the components required for their release, at least one of the battery stack assemblies of the battery assembly according to the present invention may further comprise an exhaust duct located outside the housing, connecting at least two of the through-holes and comprising an outlet opening. Thus, each battery stack assembly only needs to be provided with a single outlet opening for the runaway thermal gases, which reduces the installation effort when installing the corresponding battery assembly in a superstructure such as an electric propulsion VTOL aircraft.

[0014] The battery assembly according to the present invention may, of course, comprise only a single battery stack assembly stacked on its base plate assembly. However, in order to maximize capacity and possible output voltage while maintaining a suitable form factor, the battery stack assembly may also comprise multiple substantially identical battery stack assemblies, the stacking orientation of which the multiple substantially identical battery stack assemblies are arranged in parallel. These multiple battery stack assemblies may be arranged, for example, in a row adjacent to each other, or in several rows forming a rectangle. This makes it possible to provide a lightweight battery pack with very good crash characteristics, in particular, because crash absorption features may be located below the base plate assembly, as part of a higher structure on which the battery assembly is installed, especially as part of an aircraft.

[0015] In such embodiments of the battery assembly according to the present invention, an exhaust manifold may be provided for connecting the outlet openings of multiple battery stack assemblies. This exhaust manifold can further reduce the installation effort of the battery assemblies because, even in embodiments having multiple battery stack assemblies, only a single outlet is provided for thermal runaway gases that must be connected to a single leadout.

[0016] In embodiments having multiple battery stack assemblies, the battery assembly according to the present invention may further comprise a superstructure assembly for mechanically connecting the multiple battery stack assemblies, preferably the superstructure assembly may comprise mounting points for attaching the battery assembly to a higher structure. Thus, the superstructure assembly primarily functions as a means for improving the overall rigidity and mechanical stiffness of the battery assembly and may enable the battery assembly to be fixed to a higher structure, such as an electric propulsion VTOL aircraft, using its mounting points.

[0017] With respect to a base plate assembly for a battery assembly according to the present invention, the base plate assembly may include a structural cover and an internal space for supporting at least one battery stack assembly, the internal space may house electronic components for managing the battery assembly, in particular at least one cell supervisory circuit, at least one current sensor module, at least one power controller and / or one pyro fuse, and / or the base plate assembly, the structural cover in particular may include a bottom mounting point for mounting the battery assembly to a higher structure, and / or adjacent battery assemblies for connecting them in parallel. Thus, by integrating such electronic components into the base plate assembly, the overall size of the battery assembly may be reduced, and it becomes possible to position such electronic components in close proximity to the battery cells that the electronic components supervise and manage. Herein, the structural cover for supporting at least one battery stack assembly must have sufficient mechanical strength to support the expected load, while the size and shape of the internal space can be selected in different configurations depending on the electronic components to be housed in the internal space.

[0018] As briefly described above, at least one barrier plate member of the battery assembly according to the present invention may be formed to have mechanical strength, which is sufficient to support at least the mass of all components of the battery cell module located directly above the at least one barrier plate member, preferably the mass of all battery cell modules located above the at least one barrier plate member, and / or the at least one barrier plate member may have a thermal insulating material on its surface. Thus, the objective of thermally and mechanically isolating any thermal runaway events that may occur within the battery cell module separated by the corresponding barrier plate member can be ensured.

[0019] The number of battery cells in at least one battery stack and the number of battery cell modules can be selected almost arbitrarily, for example, taking into account the overall available size of the corresponding battery assembly, as well as its intended capacity and output voltage. However, in a preferred embodiment, at least one battery stack assembly may contain a total of 54 battery cells, and / or each of the battery cell modules may contain six battery cells or a single battery cell with a corresponding number of barrier plate members inserted between the corresponding battery cells of the battery stack assembly.

[0020] In another aspect, the present invention relates to an electric propulsion VTOL aircraft comprising a fuselage, at least a pair of wings, at least one electric propulsion motor, and at least one battery assembly. In particular, to optimize the aircraft's center of gravity and weight distribution, multiple battery assemblies may be provided and positioned symmetrically on the lateral sides of the fuselage.

[0021] In yet another aspect, the present invention relates to a method for assembling a battery assembly according to the present invention, the method comprising the steps of stacking a plurality of battery cells on top of each other, with at least one barrier plate member inserted at a desired position between a pair of adjacent battery cells, for each of at least one battery stack assembly; compressing the resulting battery cell stack along the stacking direction; and positioning the housing around the battery cell stack by fixing the housing to the barrier plate member and optionally to upper and / or lower compression plates, the housing may preferably include four individual side walls or a single side wall and a U-shaped wall member. In particular, one of the side walls may be provided with through-holes and overpressure exhaust holes for each of the separate sealed modules of battery cells separated by the barrier plate member.

[0022] Further features and advantages of the present invention will become clearer from the following description of its embodiments. [Brief explanation of the drawing]

[0023] [Figure 1] A single battery cell stack included in a battery assembly according to the present invention. [Figure 2] Battery stack assembly of the battery assembly according to the present invention, as shown in exploded view and assembly view. [Figure 3] A battery assembly according to the present invention, as shown in an exploded view. [Figure 4] Battery assembly shown in Figure 3 in two separate figures during a thermal runaway event. [Figure 5] A schematic isometric view of a VTOL aircraft according to the present invention.

[0024] Figure 1 shows, in an isometric view, a single battery cell stack 10 included in and considered below for the battery assembly according to the present invention. The battery cell stack 10 consists of a total of 54 individual battery cells 12 that are stacked along the stacking direction S and electrically connected in parallel or in series. The battery cells 12 may be, for example, of a known pouch type and may be lithium-based. Within the battery cell stack 10, a total of nine separate modules 14 of six battery cells 12 each are formed by inserting a barrier plate member between each adjacent battery cell 12. At this point, it must be mentioned that other numbers of modules per cell stack and other numbers of battery cells per module may be used in other embodiments of the present invention, for example, a single battery cell per module. Further, the battery cell stack 10 includes an upper compression plate 18a and a lower compression plate 18b that are adapted to compress the battery cell stack 10 along the stacking direction S in the assembled state.

[0025] Figure 2 shows, in both an exploded view and an assembly view, a battery stack assembly 20 that includes the battery cell stack 10. In addition to the cell stack 10, the battery stack assembly 20 includes a housing 22 that, in turn, includes two side walls 24, a rear wall 26, and a front wall 28. In the present specification, the front wall 28 for each individual battery cell module 14 is formed by a through hole 30 with an overpressure exhaust hole. The through hole is, in turn, connected by an exhaust duct member 32 that has a single outlet opening 34.

[0026] When installed within the housing 22 in its assembled state, the battery stack assembly further includes a cooling device 36 that extends inside the housing 22 and includes cooling plates 38 connected for the individual battery cell modules 14. The cooling device 36 may be connected to a central cooling system of a higher structure, such as the common cooling system 110 of the aircraft 100 shown in FIG. 5.

[0027] Similarly, the electronic device 40 is installed inside the housing 22 and extends into each battery cell module 14. The electronic device 40 may include, for example, one temperature sensor for each battery cell module 14 and one voltage sensor for each battery cell 12, and can deliver corresponding data to an electronic component 50 responsible for supervising and monitoring the functions of the battery cells 12 described below. Similar means may be provided for connecting them in series or in parallel to output the power of the individual battery cell modules 14 and recharge them after operation.

[0028] As can be particularly seen in the assembled view on the right side of FIG. 2, in the assembled state of the battery stack assembly 20, the barrier plate member 16 of the battery cell stack 10 is fixed to the housing 22 in order to effectively seal the individual battery cell modules 14 from each other and provide mechanical stability and strength to the assembly 20. For this purpose, different techniques for fixing the barrier plate member 16 to the housing 22, such as bolting and welding, may be used. Also, in particular, considering that the sealing performance of the barrier plate member 16 should not be impaired by the cooling device 26 and the electronic device 40 that extends inside the housing 22 and into each individual battery cell module 14, it is necessary to use suitable means for sealing the battery cell modules 14 from each other.

[0029] Here, Figure 3 shows an exploded view of a battery assembly 42 according to the present invention. The battery assembly 42 comprises a total of four identical battery stack assemblies 20, each aligned perpendicular to their common stacking direction S and stacked on a base plate assembly 44, so that the individual battery cells 12 of the corresponding battery stack assembly 20 can also be considered to be stacked on the base plate assembly 44 along the stacking direction S. This particular orientation can be beneficial in the case of large forces acting in the vertical direction because it can minimize damage to the cells 12 and the overall structure of the battery assembly 42 due to the stacking and compression of the battery cells, as well as the orientation of the housing 22 and base plate assembly 44. In the specific use case of a VTOL aircraft, the stacking direction S of the battery assembly 42 may correspond to the vertical direction of the aircraft, and as a result the battery assembly 42 may remain intact even in the event of a hard landing or crash.

[0030] The base plate assembly 44 itself consists of a structural cover 46 for actually supporting the battery stack 20 and a lower wall member 48, with an internal space formed between the structural cover 46 and the lower wall member 48 for housing electronic components 50 for managing the battery assembly 42. The electronic components 50 may include, for example, at least one cell supervisory circuit, at least one current sensor module, at least one power controller, and / or one pyro fuse. However, such examples for the electronic components 50 are known in the art, and by integrating the electronic components into the base plate assembly 44, the electronic components can be positioned in close proximity to the battery cells 12 that they are to supervise and monitor, and can be connected to the aforementioned electronic devices 40, as well as the wires connecting the individual battery cells 12. Thus, the overall size of the battery assembly 42 can be reduced.

[0031] Additionally, the battery assembly 42 comprises a superstructure assembly 52 that, in a similar manner, mechanically connects to the battery stack assembly 20 and increases the mechanical strength of the battery assembly 42 in a direction perpendicular to the stacking direction S. Both the base plate assembly 44 and the superstructure assembly 52 may be provided with a bottom mounting point and a top mounting point, respectively, to enable the battery assembly 42 to be mounted to a superstructure such as a VTOL aircraft.

[0032] Furthermore, Figure 3 also shows an exhaust manifold 54, which, in its assembled state, connects all the single outlet openings 34 of the four battery stack assemblies 20 in such a manner that a single common outlet opening 56 is formed, so that if a thermal runaway event occurs in any of the battery stack assemblies 20, the resulting gases can be safely and controlledly guided through its exhaust manifold 54.

[0033] Here, Figure 4 shows the battery assembly 42 of Figure 3 in two views during a thermal runaway event: a front view on the right and a cross-sectional view on the left along plan AA. In this specification, the thermal runaway event occurs in the bottommost battery cell module 14 of the battery stack assembly 20 on the right. Due to the resulting overpressure, the overpressure exhaust port of the through-hole 30 corresponding to this particular battery cell module 14 ruptures, and the emerging combustion gases are directed through the exhaust duct 32 and its outlet opening 34 to the exhaust manifold 54, and then from the battery assembly 20 through its corresponding outlet opening 56. Thus, the thermal effects of the thermal runaway event are limited to the corresponding battery cell module 14, as well as the exhaust duct 32 and exhaust manifold 54. Due to the structure of the battery assembly 42 according to the present invention, adjacent battery cell modules 14 and battery stack assembly 20 are sufficiently isolated with respect to both thermal and mechanical effects so that no adverse effects are expected on them.

[0034] Finally, Figure 5 shows a VTOL aircraft according to the present invention in a schematic form, generally referred to as reference numeral 100. The aircraft 100 comprises a fuselage 102, a pair of wings 104, and a pair of canards positioned further forward of the wings 104 with respect to the main horizontal flight direction X of the aircraft 100, although these are not shown in Figure 5 for clarity.

[0035] For each of the wings 304 and canards, a plurality of propulsion unit structures 106 are connected using dedicated attachment assemblies, which allow the propulsion motors 108 integrated with the propulsion unit structures 106 to pivot relative to the wings 104 or canards around their respective axes Y, where Y substantially corresponds to the width direction of the aircraft 100. Each of the propulsion unit structures 106 is pivotably mounted to the trailing edge of the respective wings 104 or canards and is formed as a flap supporting at least one propulsion motor 108. In this specification, the propulsion motor 108 is formed by an electrically driven rotor, particularly in a ducted fan configuration.

[0036] To supply electrical energy to the motor 108, the battery assembly 42 according to the embodiments of Figures 3 and 4 is provided to the fuselage 102 of the aircraft 100, specifically integrated into its cabin sidewalls, and wired and controlled for the motor 108, as well as the corresponding operation of other electrical components of the aircraft 100. In the aircraft 100, the stacking direction S of the battery stack assembly of the battery assembly 42 is aligned with the vertical direction Z of the aircraft 100 to optimize force distribution in the event of a hard landing or even a collision. A common cooling system 110 is provided to all of the battery assemblies 42 to control their operating temperatures during flight of the aircraft 100, as can also be seen in Figure 5.

Claims

1. A battery assembly (42) for use in an electric propulsion VTOL aircraft (100), - Base plate assembly (44), - comprising at least one battery stack assembly (20), each battery stack assembly (20) A plurality of battery cells (12) are stacked on the base plate assembly (20) along the stacking direction (S), thereby forming a battery cell stack (10) and electrically connected in parallel or series, ○A housing (22) that surrounds the battery cell (12) on all four sides, A battery assembly (42) comprising at least one barrier plate member (16) inserted between adjacent battery cells (12) and connected to the housing (22) to form at least two separate sealed modules (14) of at least one battery cell (12) within the corresponding battery stack assembly (20).

2. The battery assembly (42) according to claim 1, wherein at least one of the battery stack assemblies (20) comprises an upper compression plate (18a) and / or a bottom compression plate (18b) that compresses the cell stack (10) along the stacking direction (S).

3. A battery assembly (42) according to any one of the prior claims, wherein at least one of the battery stack assemblies (20) further comprises a cooling device (36) extending inside and / or outside the housing (22) through and / or into each battery cell module (14), preferably in the form of a continuous connected cooling plate (38) for each of the individual battery cell modules (14), or in the form of a continuous cooling plate across the battery stack.

4. At least one of the battery stack assemblies (20) further comprises an electronic device (40) extending inside the housing (22) and into each battery cell module (14), wherein the electronic device (40) preferably comprises at least one of a temperature sensor and a voltage sensor, for example, one temperature sensor for each battery cell module (14) and / or one voltage sensor for each battery cell (12), as described in any one of the prior claims, the battery assembly (42).

5. The battery assembly (42) according to any one of the prior claims, wherein for each battery cell module (14), the housing (22) of the battery stack assembly (20) is provided with through-holes (30) having overpressure exhaust holes, and preferably all of the through-holes (30) are located on the same side surface of the housing (22).

6. The battery assembly (42) according to claim 5, wherein at least one of the battery cell stacks (20) further comprises an exhaust duct (32), the exhaust duct (32) is located outside the housing (22), connects at least two of the through holes (30), and comprises an outlet opening (34).

7. A battery assembly (42) according to any one of the prior claims, comprising a plurality of substantially identical battery stack assemblies (20), wherein the stacking direction (S) of the plurality of substantially identical battery stack assemblies (20) is arranged in parallel.

8. The battery assembly (42) according to claims 6 and 7, further comprising an exhaust manifold (54) connecting the outlet openings (34) of the plurality of battery stack assemblies (20).

9. The system further comprises a superstructure assembly (52) for mechanically connecting the plurality of battery stack assemblies (20), Preferably, the superstructure assembly (52) is provided with an upper mounting point for attaching the battery assembly (42) to the superstructure, according to claim 7 or 8.

10. The base plate assembly (44) comprises a structural cover (46) for supporting the at least one battery stack assembly (20), and an internal space, within which electronic components (50) for managing the battery assembly (42), in particular at least one cell monitoring circuit, at least one current sensor module, at least one power controller, and / or one pyrofuse are housed. and / or The battery assembly (42) according to any one of the prior claims, wherein the base plate assembly (44), in particular the structural cover (46), is provided with a bottom mounting point for mounting the battery assembly (42) to a higher structure and / or an adjacent battery assembly.

11. The at least one barrier plate member (16) is formed to have mechanical strength, and the mechanical strength is sufficient to support at least the mass of all components of the battery cell module (14) positioned above the at least one barrier plate member (16), preferably the mass of all battery cell modules (14) positioned above the at least one barrier plate member (16), and / or The battery assembly (42) according to any one of the prior claims, wherein at least one barrier plate member (16) is provided with a non-combustible material and / or a heat insulating material on its surface.

12. The at least one battery stack assembly (20) comprises a total of 54 battery cells (12), and / or The battery assembly (42) according to any one of the prior claims, wherein each battery cell module (14) of the at least one battery stack assembly (20) comprises six battery cells (12) or a single battery cell.

13. An electric propulsion VTOL aircraft (100) comprising a fuselage (102), at least a pair of wings (104), at least one electric propulsion motor (108), and at least one battery assembly (42) as described in any one of the prior claims.

14. The electric propulsion VTOL aircraft (100) according to claim 13, wherein a plurality of battery assemblies (42) are provided and positioned symmetrically on the lateral side walls of the fuselage (102).

15. A method for assembling a battery assembly (42) according to any one of claims 1 to 12, wherein for each of the battery stack assemblies (20): a) The steps of stacking the plurality of battery cells (12) on top of each other, with at least one barrier plate member (16) inserted at a desired position between a pair of adjacent battery cells (12), b) The step of compressing the resulting battery cell stack (10) along the stacking direction (S), c) Installing the housing (22) around the battery cell stack (10) by fixing it to the barrier plate member (16) and optionally the upper and / or lower compression plates (18a, 18b), The method wherein the housing (22) preferably comprises four individual side walls (24, 26, 28) or a single side wall and a U-shaped wall member.

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