CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to German Patent Application DE 10 2017 218 310.1 filed Oct. 13, 2017, the entire disclosure of which is incorporated by reference herein.

TECHNICAL FIELD

The present disclosure relates to a battery housing for the structural integration of a battery in a vehicle, in particular an aircraft or spacecraft, to a battery arrangement with a battery housing of this type and to a method for producing such a battery housing.

BACKGROUND

Although usable in diverse applications, the present disclosure and the problem on which the disclosure herein is based will be explained in more detail with respect to passenger aircraft. However, the described methods and devices can also be used in different vehicles and in all sectors of the transport industry, for example for road vehicles, for rail vehicles, for aircraft or for watercraft.

Lithium-ion batteries can be encountered as rechargeable energy accumulators in the most diverse sectors of the art. In particular, they serve in electro mobility as energy accumulators for electric cars and hybrid vehicles. For this purpose, many manufacturers implement a multiplicity of batteries in the form of what are referred to as battery packs in the region of the floor of a vehicle body, see, for example, the documents DE 10 2011 005 403 A1 and EP 2 008 354 A2. It may be entirely necessary in this case to connect several thousand individual cells to one another, e.g. lithium-ion round cells having a cylinder diameter of approximately 20 mm and a length of approximately 100 mm. However, the generic integration concepts pursued in this case are not always suitable for meeting the technical requirements and boundary conditions for aircraft in a structural respect.

The document DE 10 2005 024 408 A1 describes a method for reinforcing foam materials during the production of fiber-reinforced plastics components, the method also being referred to as the “tied-foam-core” technique. In the method, a foam material is provided with fiber bundles which are introduced into the foam material with a needle. In this case, a through hole is first of all pricked into the foam material from one side with the needle in order then to be able to pick up a fiber bundle located on the other side with the needle and pull same into the foam material. The through hole with the fiber bundle located therein is subsequently infiltrated with a matrix material, e.g. a synthetic resin, and cured such that, as a result, the foam material is pierced with rigid pins and reinforced. For a sandwich structure, this infiltration step can be carried out when cover layers have already been applied, wherein the cover layers and the reinforced core material can be cured together.

SUMMARY

Against this background, the present disclosure is based on the object of finding solutions for cost-effectively and simultaneously securely integrating a large number of batteries in a vehicle.

According to the disclosure herein, this object is achieved by a battery housing, a battery arrangement, and a method with features disclosed herein.

According thereto, a battery housing for the structural integration of batteries in a vehicle, in particular an aircraft or spacecraft, is provided. The battery housing comprises an inner housing for receiving a battery, and an outer housing which surrounds the inner housing in such a manner that a cavity is formed between the inner housing and the outer housing, wherein a multiplicity or plurality of pins are formed in the cavity and connect the inner housing to the outer housing.

Furthermore, a battery arrangement comprising at least one battery housing according to the disclosure herein is provided. The battery arrangement furthermore comprises at least one battery which is arranged in the inner housing of the at least one battery housing.

Furthermore, an aircraft or space craft comprising a battery arrangement according to the disclosure herein is provided.

A method for producing at least one battery housing for the structural integration of batteries in a vehicle, in particular an aircraft or spacecraft, is furthermore provided. The method comprises forming, in particular two, housing half shells from a foam material, wherein each housing half shell is formed on at least one inner side with at least one receiving depression; covering the inner side and an outer side opposite the inner side with a respective cover layer; connecting the cover layer of the outer side to the cover layer of the inner side at least in the region of the at least one receiving depression via pins and/or fiber bundles; joining together the housing half shells on the inner sides, which are provided with a cover layer, to form a housing shell, wherein the receiving depressions of the housing half shells in each case in pairs form an inner housing for receiving a battery, and the outer sides of the housing shells in each case form an outer housing surrounding the inner housing; infiltrating the housing shell with a matrix material; and curing the housing shell to form at least one battery housing.

A concept on which the present disclosure is based consists in or comprises in each case encapsulating a battery in a dedicated housing, wherein an inner housing is surrounded by a cavity which can be used for different purposes and which is also pierced by structure-reinforcing pins which structurally anchor the inner housing in an outer housing. The pins can advantageously be designed, arranged and oriented here in different embodiments, depending on which requirements the specific application poses to a person skilled in the art. The cavity can be used, for example, in order to regulate the operating temperature of the enclosed battery, for example by an airflow or in general a fluid flow being conducted through the cavity. In a departure from fluids for regulating temperature, a suitable extinguishing agent or fire-retardant fluid can also be introduced in the event of damage. Furthermore, a cavity of this type can serve as an outlet channel in order to conduct away gases or liquids which possibly occur in the event of damage. The inner housing can advantageously be designed in such a manner that thermal expansion of the battery is made possible in order to meet any operating conditions. In this case, the pins can connect the inner housing to the outer housing in a flexible manner such that the inner housing is movable to a certain extent inside the outer housing.

Such an encapsulation of a battery affords advantages in particular in the aerospace sector where, because of the high power requirements, ten thousand or more individual batteries or individual cells have to be installed, depending on the vehicle, in order, for example, to supply an electric drive with energy. It may be necessary in this connection to heat or to cool the batteries in order to set as efficient a working point as possible. Furthermore, the optimum working point can greatly vary during use of the vehicle (e.g. during take off, landing, taxiing and/or flight mode, etc.), wherein general operating temperatures of the vehicle may quite possibly fluctuate between −55° degrees and 75° degrees or more, but at least batteries nowadays should optimally operate approximately at room temperature. Added to this is the fact that, during operation, each battery generates thermal energy of the order of magnitude of several watts which should likewise be conducted away. As a result, it may be required, depending on use, for each individual battery to be individually connected and controlled or regulated and able to be replaced when required. The present disclosure now precisely permits this, with it being assured in particular in the event of damage, because of the physical separation that adjacent batteries are not affected, e.g. by the gases which possibly occur under high pressure and high temperature. The dimensioning of the cavity, or the outer dimensions of the battery housing, can be correspondingly advantageously selected in order, for example, to permit a desired volumetric flow of a fluid through the cavity.

A battery within the context of the disclosure herein is a general, rechargeable electric accumulator element. It may be a secondary cell, i.e. an individual accumulator element in the sense of a secondary element, a battery cell, a rechargeable cell or the like. However, batteries according to the disclosure herein in principle also comprise interconnected secondary cells and/or interconnected accumulator elements, i.e. a battery consisting of secondary cells. Batteries within the context of the disclosure herein in particular comprise lithium-ion batteries. The present disclosure is primarily concerned with the structural mounting or holding of batteries. The specific electrical circuitry and connection of the batteries can be carried out in any manner familiar to a person skilled in the art.

A further concept on which the disclosure herein is based involves the use of method steps which are particularly suitable for the cost-efficient mass production of fiber composite components, wherein the latter in turn have particular advantages especially in the air travel sector. During the production, the battery housing is defined here in the interior by a foam material which, inter alia, serves as a shaping tool during the production. By the foam material as support material, pins and/or fiber bundles (which are cured later by resin infiltration to form pins) can be introduced via the advantageous “tied-foam-core” technique in an automated method for reinforcing the housing and for connecting the inner housing and the outer housing. This technique is particularly efficient in terms of time and costs and is therefore especially suitable for the mass manufacturing of identical modules. Individual battery housings can then be readily connected in diverse arrangements and orientations to form rows, panels and/or packs of battery housings, with it being possible for several thousand individual batteries to be combined. Such an arrangement can advantageously also be undertaken prior to the infiltration with a resin system, or prior to the curing, in order to achieve an overall integral structure. In addition, the housing half shells used during the production can be used for different purposes. For example, cavities can be defined in order to conduct cooling and/or heating fluids or the like through the housing. The cavity between the inner housing and the outer housing can be configured as a safety barrier for emergency situations or malfunctions.

According to one development, a separating layer can be provided. The separating layer can be formed in the cavity. The separating layer can connect the inner housing to the outer housing in such a manner that the cavity is divided by the separating layer into two separate regions. The separating layer can be used for different purposes and applications.

For example, the separating layer can divide the cavity into two regions which are separated in a fluid-tight manner. The two separate regions can be used for the conducting through of fluids in different directions, e.g. cooling fluids, heating fluids, extinguishing fluids, etc. In one example, one region can be used as an outlet channel for toxic substances which may leak out of the battery in the event of damage. By contrast, the other region can be used for the conducting through of a cooling liquid.

For example, the separating layer can be designed as a stiffening layer of the battery housing. In this advantageous embodiment, the separating layer can therefore be used in order to form the battery housing to be robust in relation to severe accelerations. For example, a plurality of battery housings can be connected to one another in a different orientation, wherein the separating layers serve as stiffening regions. In one example, a panel consisting of battery housings can be provided, with the separating layer being oriented in a normal direction. Within this context, the separating layer can be designed for improving the flexural rigidity, the shearing resistance and/or rigidity to shearing force of the overall assembly.

According to one development, the method can furthermore comprise removing the foam material from the battery housing for forming a cavity between the inner housing and the outer housing. For this purpose, for example, a mechanical and/or chemical treatment of the foam material can be provided, e.g. a sandblasted process and/or a liquid solvent.

According to one development, the cavity can be at least partially filled with a foam material. The foam material can therefore be at least partially let into the cavity, or a foam material can be introduced retrospectively. The foam material can be used, for example, for thermal insulation or for improvement of the fire resistance of the battery housing. For example, the foam material can be provided in one of the separate regions defined by a separating layer while the other region can be determined for the conducting through of a cooling liquid or outgassing.

According to one development, the inner housing and the outer housing can be formed from plastic, in particular fiber-reinforced plastic. The pins can be formed by resin-infiltrated fiber bundles. For example, use can be made of carbon fibers, glass fibers and/or aramid fibers or the like. For example, a synthetic resin or another plastic known to a person skilled in the art can be used as the plastics or matrix material.

According to one development, the inner housing can be designed for receiving the battery in a precisely fitting manner. Within this context, any movement of the battery within the battery housing is suppressed. This is relevant especially in the case of aircraft since vibrations can occur here over a broad spectrum of frequencies and amplitudes and the batteries should furthermore be protected as well as possible in the event of impacts or strikes. However, it is alternatively also possible for a certain clearance to be left between the battery and the inner housing. In this case, the movement of the battery can be restricted via additional measures. For example, the manner of this measure may also facilitate a subsequent exchange of individual battery cells.

According to one development, the inner housing can be of cylindrical design for receiving a cylindrical battery. The battery housing according to the disclosure herein can thus be designed, for example, for receiving known and possibly standardized lithium-ion batteries.

According to one development of the battery arrangement, the at least one battery can be fastened in the inner housing.

According to one development of the battery arrangement, the at least one battery can be connected in an integrally bonded manner to the inner housing. For example, the battery can be fitted in the inner housing with a thermally conductive adhesive. For example, it is possible to select an adhesive which is dissolvable by action of radiation or the like such that the battery is exchangeable in the event of damage. Alternatively or additionally, the at least one battery can be fastened in a mechanically releasable manner to the inner housing, e.g. with a mechanical holder and/or via a plug-in, click and/or snap-action mechanism.

According to one development of the battery arrangement, the inner housing together with the battery can define an intermediate space which can be filled with a low-viscosity liquid. The low-viscosity liquid makes it not only possible to limit or to virtually completely suppress the movement of the battery within the inner housing. Furthermore, the low-viscosity liquid can be used for thermal conduction, i.e. more effectively cooling and/or heating up the battery.

According to one development of the battery arrangement, a plurality of battery housings and a plurality of batteries can be provided. It is firstly possible to connect individual battery housings to one another after their individual production, for example by adhesive bonding or other joining methods. Secondly, a battery arrangement comprising a plurality of battery housings can already be manufactured directly as an (integral) multiple module.

The cavities of the individual battery housings of the battery arrangement can be separated off from one another in a fluid-tight manner in this development. This affords the advantage that the batteries can be operated in a manner decoupled from one another in the individual battery housings. For example, the cavity can be used in each case for conducting away and/or conducting in fluids without any effect on the adjacent batteries occurring.

According to one development, the battery arrangement can be designed as a sandwich panel, cladding panel and/or floor panel and/or the like. Within this context, the battery arrangement according to the disclosure herein can be designed in particular as a multifunctional sandwich panel having structurally integrated batteries, which can be used, for example, as a floor panel and can furthermore be provided with thermal-insulation and/or air-conditioning properties.

According to one development of the method, the housing half shells can be formed with a plurality of receiving depressions such that a plurality of battery housings are produced simultaneously.

According to one development of the method, a shape-maintaining tool can be temporarily introduced into the receiving depressions of the two housing half shells in order to set a desired shape of the inner housing during the curing. For example, the receiving depressions can be at least temporarily filled with a metal cylinder which, during the following method steps, ensures the desired shape for the inner housing.

The above refinements and developments can be combined with one another as desired, if expedient. Further possible refinements, developments and implementations of the disclosure herein also comprise combinations, which are not explicitly mentioned, of features of the disclosure herein described previously or below with respect to the exemplary embodiments. In particular, a person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the present disclosure.

