Battery housing

Abstract

The invention relates to a battery housing (100) for receiving a plurality of battery cells or battery modules, in particular in an electrically drivable vehicle, comprising an one-piece, hot-formed and press-hardened receiving trough (101) made of steel for receiving the plurality of battery cells or battery modules, wherein the receiving trough (101) has a baseplate (103) and an outer wall (105) which is arranged around the baseplate (103), wherein the outer wall (105) delimits a trough interior (107) of the receiving trough (101), wherein a flange (109) around the outer wall (105) is arranged on the outer wall (105) of the receiving trough (101), which flange extends at an angle to the outer wall (105) of the receiving trough (101), wherein the receiving trough (101) has a tensile strength of at least 1300 MPa at least in some sections; and a corrugated bottom walling (111) which is made of a steel alloy and has a plurality of bearing sections (115) which are each integrally bonded to the baseplate (103) of the receiving trough (101) by way of a soldered connection (117), and wherein the corrugated bottom walling (111) has a plurality of extension sections (119) which are arranged at a distance from the baseplate (103) of the receiving trough (101), wherein the plurality of extension sections (119) of the corrugated bottom walling (111) and the baseplate (103) of the receiving trough (101) delimit a plurality of fluid guiding channels (121) for guiding a fluid, wherein the soldered connections (117) between the baseplate (103) of the receiving trough (101) and the bearing sections (115) of the corrugated bottom walling (111) are designed to provide fluidic sealing of the fluid guiding channels (121).

Description

[0001] Battery enclosure

[0002] The present disclosure relates to a battery housing for accommodating a plurality of battery cells or battery modules, in particular in an electrically driven vehicle, and to a method for producing a battery housing.

[0003] Battery enclosures are used in a wide range of technical applications to house batteries, in particular battery cells and / or battery modules, and to protect them from external environmental influences, for example to provide electrical energy in electrically powered vehicles or in battery storage systems to provide electrical energy in buildings.

[0004] To ensure a consistent temperature of the batteries, especially battery cells and / or battery modules, during operation, there is a need to provide temperature-controlled battery enclosures. This is achieved in conventional battery enclosures, for example, by installing separate plate heat exchangers or cooling plates for flowing fluid through cooling channels. Furthermore, there is a need to provide mechanically stable battery enclosures that are easy to manufacture.

[0005] The document DE 10 2012 012 663 A1 discloses a housing for a battery pack of a vehicle drive battery.

[0006] The document DE 10 2012 018 105 A1 discloses a method for producing a battery carrier for holding an electric battery module.

[0007] It is the object of the present disclosure to provide a temperature-controlled battery housing which is mechanically stable and which is easy to manufacture.

[0008] This object is achieved by the features of the independent claims. Advantageous embodiments are the subject of the dependent claims, the description, and the accompanying figures. The present disclosure is based on the finding that a two-piece design of the battery housing comprising a receiving tray and a corrugated bottom wall, which are connected to one another by soldered joints, provides an advantageous battery housing with integrated fluid channels for conducting fluid.

[0009] The present disclosure is based on the further finding that by using a hot forming step and a press hardening step during the manufacture of the battery housing, a particularly high tensile strength of the receiving tray and thus a high structural stability of the battery housing can be achieved.

[0010] According to a first aspect, the disclosure relates to a battery housing for accommodating a plurality of battery cells or battery modules, in particular in an electrically driven vehicle, comprising a one-piece, hot-formed, and press-hardened steel receptacle for accommodating the plurality of battery cells or battery modules, wherein the receptacle has a base plate and an outer wall arranged circumferentially around the base plate, wherein the outer wall delimits a trough interior of the receptacle, wherein a flange is arranged circumferentially around the outer wall of the receptacle and extends at an angle to the outer wall of the receptacle, wherein the receptacle has, at least in sections, a tensile strength of at least 1300 MPa; and a corrugated base wall made of a steel alloy, which has a plurality of contact sections,which are each integrally connected to the base plate of the receiving tray by a solder joint, and wherein the corrugated base wall has a plurality of extension sections arranged at a distance from the base plate of the receiving tray, wherein the plurality of extension sections of the corrugated base wall and the base plate of the receiving tray delimit a plurality of fluid guide channels for guiding a fluid, wherein the solder joints between the base plate of the receiving tray and the contact sections of the corrugated base wall are designed to provide a fluidic seal for the fluid guide channels. This achieves the technical advantage that a plurality of fluid guide channels for guiding fluid are formed integrally in the battery housing by the solder joints between the corrugated base wall and the base plate of the receiving tray.and that the hot forming and press hardening during the manufacture of the battery housing can produce a receptacle which has a particularly high structural stability.

[0011] Alternatively, the one-piece, hot-formed steel receptacle may be made of a non-press-hardened material.

[0012] In one embodiment, an extension section of the corrugated bottom wall is arranged between each two adjacent contact sections of the corrugated bottom wall, wherein the respective soldered connections between the respective two adjacent contact sections of the corrugated bottom wall and the bottom plate of the receiving trough are designed to provide a fluidic seal of the fluid guide channel, which is delimited by the respective extension section of the corrugated bottom wall and the bottom plate of the receiving trough.

[0013] This provides the technical advantage of creating an effective material connection between the corrugated base wall and the base plate, and also allowing the fluid guide channels to be effectively sealed from one another.

[0014] In one embodiment, the base plate of the receiving tray protrudes beyond the corrugated base wall.

[0015] This achieves the technical advantage that the double-layer design is only present in the area of ​​the base plate, and in a curved transition area between the base plate and the outer wall, the receiving tray is designed as a single layer, which facilitates the molding process of the receiving tray and ensures the pre-formed or specified geometry and dimensional accuracy of the fluid guide channels during the hot forming of the receiving tray.

[0016] In particular, the receiving tray has a curved transition region that connects the base plate to the outer wall of the receiving tray. The base plate extends in particular straight, in particular horizontally, and the outer wall extends in particular straight, in particular vertically, and the curved transition region has a curvature.

[0017] In one embodiment, the outer wall of the receiving trough has a tensile strength of at least 1300 MPa, at least in sections, in particular completely. Preferably, the transition region also has a tensile strength of at least 1300 MPa.

[0018] This achieves the technical advantage that a particularly stable battery housing is provided due to the corresponding tensile strength of the outer wall or the transition area of ​​at least 1300 MPa.

[0019] In one embodiment, the base plate of the receiving trough has at least one section with a tensile strength of at least 1300 MPa and the base plate of the receiving trough has at least one further section with a tensile strength of less than 1300 MPa, wherein the base plate of the receiving trough has in particular a plurality of contact regions which bear against the contact sections of the corrugated base wall, wherein the contact regions have a tensile strength of at least 1300 MPa, and / or wherein the base plate of the receiving trough has in particular a plurality of exposed regions which are spaced apart from the extension sections of the corrugated base wall, wherein the exposed regions have a tensile strength of 600 MPa to 1200 MPa.

[0020] This achieves the technical advantage that, due to the press hardening following soldering during the manufacture of the battery housing, different sections with high and low tensile strength are obtained in the base plate due to the manufacturing process. Particularly in the area of ​​the soldered joints, i.e., at the contact areas of the base plate, the base plate has a tensile strength of at least 1300 MPa. Particularly in the exposed area of ​​the base plate, i.e., between the contact areas, the base plate has a tensile strength of less than 1300 MPa, in particular between 600 MPa and 1200 MPa. The tensile strength preferably results from incomplete or missing hardening of the exposed areas, so that, in particular, the metallic ferritic-pearlitic microstructure of the initial state is recreated.

[0021] In one embodiment, the corrugated bottom wall is fastened to an inner side of the base plate of the receiving tray facing the tray interior by means of the soldered connections, or the corrugated bottom wall is fastened to an outer side of the base plate of the receiving tray facing away from the tray interior by means of the soldered connections.

[0022] This achieves the technical advantage that, depending on the installation situation, an advantageous double-layered design of the battery housing is created in the area of ​​the base plate.

[0023] In one embodiment, the receiving trough is formed from a press-hardened steel, in particular from a press-hardened manganese-boron steel (MnB steel).

[0024] Table 1 below shows possible steel alloys for the receiving trough (steel A to D) and for the corrugated bottom wall (steel E or F). The alloying elements are given in weight percent, with the remainder being iron and smelting-related impurities.

[0025] In one embodiment, the receiving tray is made of a so-called tailored welded blank (TWB).

[0026] With a Tailored Welded Blank (TWB), the steel grade is selected based on the intended load. Where hardening is intended, a press-hardenable steel alloy (steel A to D) is used, as described above, while less stressed or vulnerable sections are made of non-hardenable steel (steel E or F).

[0027] In particular, a tailored welded blank can be designed such that the formed outer walls are made of non-hardenable steel, while the base and preferably also the transition area are made of hardenable steel. The term "welded blank" describes the delivery condition, which consists of a flat, butt-welded steel sheet made from several individual sheets of different steel grades and / or with different sheet thicknesses. In this case, the "TWB" represents the precursor to the receiving trough. These are expressly not individually preformed outer walls and base plates that are only welded together after forming.

[0028] Table 1

[0029] This provides the technical advantage of achieving particularly high structural stability.

[0030] In one embodiment, the receiving trough and preferably the corrugated bottom wall has a metallic coating which is applied on one or both sides, wherein the metallic coating comprises in particular an aluminum, aluminum-silicon, aluminum-zinc, or aluminum-silicon-zinc alloy, and / or wherein the metallic coating has in particular a layer thickness between 10 .m and 50 .m, and / or wherein the metallic coating has in particular a basis weight between 60 mg / m 2 and 180 mg / m 2 has.

[0031] This achieves the technical advantage that a corresponding metallic coating protects the receiving trough from scaling during heat treatment and can also provide corrosion protection afterwards.

[0032] In particular, this coating can be implemented in combination with a solder and / or flux. In particular, the metallic coating is applied additionally and underneath the solder and / or flux, thus contributing to ensuring a fluid-tight solder connection and preventing scaling in the exposed area of ​​the base plate and the outer walls of the receiving trough during heat treatment. In the case of a corrugated base wall and an applied aluminum-silicon coating, the steel sheet can be pre-alloyed, i.e., the coated steel sheet can be heat-treated, before forming the channel structure to counteract cracking during pre-forming.

[0033] In one embodiment, the corrugated bottom wall is designed as a cold-formed bottom wall and in particular has a metallic coating as scale protection.

[0034] The cold-formed base wall creates the cooling channels in the double-layered area between the base plate and the base wall, providing the technical advantage of achieving structural stability of the corrugated base wall and the receiving trough as a whole.

[0035] In one embodiment, the corrugated bottom wall has a metallic coating as scale protection. This coating can be applied in combination with a solder and / or flux. However, the coating can also be applied only in areas not exposed to solder and / or flux, or on the side facing away from the receiving trough precursor.

[0036] In one embodiment, the base plate of the receiving trough has at least one barrier bead which is designed to limit a material flow from the base plate, in particular from the region of the soldered connections, during the hot forming of the receiving trough.

[0037] This achieves the technical advantage that the manufacturing process of the receiving trough can be optimized by the barrier bead, since any flowing material that occurs during this process can be effectively absorbed in the at least one barrier bead and thus cannot escape uncontrollably. In particular, the at least one barrier bead comprises a single barrier bead surrounding the base plate. Alternatively, and in particular, the at least one barrier bead comprises a plurality of barrier beads surrounding the base plate at least in sections.

[0038] The barrier bead can be formed on the finished, hot-formed receiving trough in the base plate near the curved transition area to the outer wall by a slight notch, in particular in the order of maximum 2 / 10 of the wall thickness compared to an area of ​​the base plate exposed further inside or in the middle.

[0039] In one embodiment, the solder joints comprise a high-melting brazing solder, which in particular comprises flux to reduce oxide formation.

[0040] This achieves the technical advantage that the solder joints are formed at high temperatures, and a protective gas atmosphere or vacuum is not required during production. In particular, a brass or nickel silver brazing alloy with a temperature range between 870°C and 920°C, or a nickel-based brazing alloy, can be used, eliminating the need for soldering in a protective gas atmosphere or even a vacuum.

[0041] In one embodiment, the outer wall of the receiving tray has at least four tray corners, wherein two tray corners are connected by a side wall section of the outer wall of the receiving tray and by the base plate of the receiving tray, wherein the battery housing has a plurality of crash frame profiles which are arranged on at least two side wall sections and are designed to absorb forces acting on the side wall section from the outside by deformation.

[0042] This achieves the technical advantage that crash frame profiles arranged on the side wall sections ensure effective structural stability of the

[0043] Ensure the receiving tray is secure even in the event of a crash.

[0044] According to a second aspect, the disclosure relates to a method for producing a

[0045] Battery housing for accommodating a plurality of battery cells or

[0046] Battery modules, in particular in an electrically driven vehicle, wherein the

[0047] Method comprising the following method steps: Providing a one-piece,

[0048] Steel existing receiving trough precursor, which has a base plate,

[0049] Providing a corrugated bottom wall made of a steel alloy, which has a plurality of contact sections and a plurality of

[0050] extension sections, applications of a particularly high-melting brazing alloy to each of the contact sections of the corrugated

[0051] Floor wall and / or onto the floor plate, bringing the corrugated

[0052] Bottom wall with the bottom plate, Joint heating of the corrugated

[0053] Bottom wall and the receiving trough precursor to form a plurality of material-fit solder joints between the contact sections of the corrugated

[0054] floor wall and the floor plate, thermoforming of the

[0055] Receptacle precursor to a receptacle for receiving the majority of

[0056] Battery cells or battery modules, wherein the receiving tray has the base plate and an outer wall which is arranged circumferentially around the base plate, wherein the outer wall delimits a tray interior of the receiving tray, wherein a flange which surrounds the outer wall is arranged on the outer wall of the receiving tray and extends at an angle to the outer wall of the receiving tray, and at least sectionally press-hardening the receiving tray in order to obtain a press-hardened receiving tray, wherein the press-hardened receiving tray has at least sectionally a tensile strength of at least 1300 MPa, such that the base plate is press-hardened at least in the region of the soldered connections.

[0057] This achieves the technical advantage of producing both the support tray itself and the completion of a floor-integrated cooling structure for the battery enclosure in a single manufacturing process. This eliminates the need for subsequent welding, which introduces critical stresses and heat-affected zones that generate notch effects, as well as the time-consuming, less durable, and less sustainable bonding of the corrugated floor wall.

[0058] In one embodiment, the hot forming and the at least partially press hardening as well as the completion of the soldered joints are carried out in a common process step and / or in a single pressing tool.

[0059] This achieves the technical advantage of simplifying the manufacturing process.

[0060] In one embodiment, bringing the corrugated bottom wall into contact with the bottom plate comprises the following further method step: pre-fixing the corrugated bottom wall to the bottom plate by spot welding.

[0061] This achieves the technical advantage of advantageous pre-positioning of the corrugated bottom wall and preventing the two sheet layers from shifting during the heating, transfer, and, above all, hot forming process steps. In one embodiment, the joint heating of the corrugated bottom wall and the receiving trough precursor comprises heating to at least one temperature corresponding to an austenitizing temperature Ac1 of the steel-formed receiving trough precursor, wherein heating is carried out, in particular, at a temperature of at least 850°C, and / or wherein the joint heating is carried out, in particular, not in a protective gas atmosphere and / or not in a vacuum atmosphere.

[0062] In one embodiment, the pressing tool itself has at least one tool projection in a tool half near the transition region of the receiving trough to be formed and the contact section of the base plate, whereby the previously described blocking bead or notch is formed in the base plate, and the material flow in the receiving trough precursor or in the steel sheet during hot forming from the base plate into the outer wall is limited or completely prevented.

[0063] This provides the technical advantage of achieving good formability and advantageous formation of the solder joints without the need for a protective gas atmosphere or a vacuum atmosphere.

[0064] In particular, the austenitizing temperature Ac1 is approximately 730°C to 770°C, with complete austenitization occurring at approximately 820°C to 850°C, so that the combined heating to at least 850°C produces an austenite structure, which can be advantageously further processed. The heating time or holding time at this temperature is at least 3.5 and preferably no more than 15 minutes.

[0065] The advantageous embodiments mentioned for the battery housing according to the first aspect are also advantageous embodiments for the method for producing the battery housing according to the second aspect and vice versa.

[0066] Further embodiments are explained with reference to the accompanying figures. Figure 1 shows a schematic representation of a battery housing according to a first embodiment;

[0067] Fig. 2 is a schematic representation of a battery housing according to a second embodiment;

[0068] Fig. 3 is a schematic top view of a battery housing according to the second embodiment;

[0069] Fig. 4 is a schematic representation of a battery housing according to a third embodiment from below;

[0070] Fig. 5 is a schematic representation of a battery housing according to a fourth embodiment from below; and

[0071] Figs. 6A-6C are a schematic representation of a method for manufacturing a battery enclosure according to an embodiment.

[0072] It is emphasized that in Figures 1 and 2, as well as 6A to 6C, vertical dashed lines are introduced, which merely schematically represent an interruption of the corresponding receiving tray.

[0073] Figure 1 shows a schematic representation of a battery housing according to a first embodiment, in particular a battery housing 100 for accommodating a plurality of battery cells or battery modules not shown in Figure 1, in particular in an electrically powered vehicle. Figure 1 shows a sectional view through the battery housing 100.

[0074] The battery housing 100 has a receiving tray 101, shown in Fig. 1, for accommodating the plurality of battery cells or battery modules. The receiving tray 101 is made of steel and is formed in one piece, in particular from a single material. The receiving tray 101 is designed as a hot-formed and press-hardened receiving tray 101. The receiving tray 101 has a base plate 103 and an outer wall 105 arranged circumferentially around the base plate 103. As can be seen from Fig. 1, the outer wall 105 delimits a tray interior 107 of the receiving tray 101.

[0075] On the outer wall 105 of the receiving trough 101 there is arranged a flange 109 which surrounds the outer wall 105 and extends at an angle, in particular almost at a right angle, to the outer wall 105 of the receiving trough 101.

[0076] The base plate 103 of the receiving tray 101 accommodates the plurality of battery cells or battery modules, wherein the battery cells or battery modules are not shown in Fig. 1. The plurality of electric battery cells or battery modules can be placed, in particular, on the base plate 103, and the battery cells or battery modules are accommodated, in particular, in receiving areas delimited by inner walls (not shown in Fig. 1).

[0077] Even if not shown in Fig. 1, the battery housing 100, particularly in the installed state, for example in a motor vehicle, has a cover which is connected to the flange 109 surrounding the outer wall 105 in order to close off the tray interior 107 from an outer region of the battery housing 100. In particular, a further flange of the cover is connected to the flange 109 of the outer wall 105, in particular by a material fit, a form fit, and / or a force fit, in order to ensure effective fastening of the cover to the outer wall 105.

[0078] As shown in Figure 1, the battery housing 100 further includes a corrugated bottom wall 111 made of a steel alloy. In particular, the corrugated bottom wall 111 is formed as a cold-formed bottom wall 111 and, in particular, has a metallic coating.

[0079] As can be seen from Fig. 1, the corrugated bottom wall 111 in the first embodiment shown in Fig. 1 is firmly bonded to a base plate outer side 113 of the base plate 103 of the receiving tray 101, said outer side facing away from the tray interior 107. As can be seen from Fig. 1, the corrugated bottom wall 111 has a plurality of contact sections 115, each of which is firmly bonded to contact areas 127 of the base plate 103 of the receiving tray 101 by a soldered connection 117, which is only schematically shown in Fig. 1.

[0080] The solder joints 117 comprise, in particular, a high-melting brazing alloy, which in particular comprises flux to reduce oxide formation.

[0081] As can be seen from Fig. 1, the corrugated bottom wall 111 has a plurality of extension sections 119, which are arranged at a distance from the bottom plate 103 of the receiving tray 101. The plurality of extension sections 119 of the corrugated bottom wall 111 and the bottom plate 103 of the receiving tray 101 define a plurality of fluid guide channels 121 for guiding a fluid. The fluid guided in the fluid guide channels 121 serves to control the temperature of the battery cells or battery modules arranged on the bottom plate 103.

[0082] The soldered connections 117 between the base plate 103 of the receiving trough 101 and the contact sections 115 of the corrugated base wall 111 are designed to provide a fluidic seal for the fluid guide channels 121.

[0083] Thus, an extension section 119 of the corrugated bottom wall 111 is arranged between each two adjacent contact sections 115 of the corrugated bottom wall 111. The respective soldered connections 117 between the respective two adjacent contact sections 115 of the corrugated bottom wall 111 and the base plate 103 of the receiving tray 101 are designed to provide a fluidic seal for the fluid guide channel 121, which is delimited by the respective extension section 119 of the corrugated bottom wall 111 and the base plate 103 of the receiving tray 101.

[0084] As shown for the embodiment of Fig. 1, the two edge-side solder joints 117, i.e. the solder joints 117 which are arranged on an edge of the base plate 103 facing the curved transition region 123 shown in Fig. 1 between the base plate 103 and the outer wall 105, are wider than the inner solder joints 117, i.e. the solder joints 117 which are spaced from the edge of the base plate 103 facing the curved transition region 123.

[0085] From Fig. 1, it can also be seen that the base plate 103 of the receiving tray 101 protrudes beyond the corrugated bottom wall 111. This provides the advantage that the curved transition region 123 between the base plate 103 and the outer wall 105 is formed as a single layer, i.e., without a soldered double layer, which facilitates the molding process of the receiving tray 101.

[0086] The two auxiliary lines 125 inserted in Figure 1 show the boundary between the outer wall 105 and the curved transition region 123, as well as the boundary between the curved transition region 123 and the base plate 103 of the receiving tray 101. The base plate 103 and the outer wall 105 of the receiving tray 101 extend straight, with the exception of the tray corners 133 visible in Figure 3, while the curved transition region 123 clearly has a curvature.

[0087] As already mentioned, the receiving tray 101 is designed as a press-hardened receiving tray 101, which means that the receiving tray 101 has a tensile strength of at least 1300 MPa, at least in sections, which enables excellent structural stability of the receiving tray 101.

[0088] In particular, the outer wall 105 of the receiving trough 101 has, at least in sections, in particular completely, a tensile strength of at least 1300 MPa.

[0089] The base plate 103 of the receiving trough 101 has, as shown in Fig. 1, a plurality of contact areas 127 which bear against the contact sections 115 of the corrugated base wall 111.

[0090] As shown in Fig. 1, the base plate 103 of the receiving tray 101 has a plurality of exposed regions 129 spaced apart from the extension sections 119 of the corrugated bottom wall 111. In particular, the base plate 103 of the receiving tray 101 has at least one section with a tensile strength of at least 1300 MPa, wherein the section in particular includes the contact regions 127 of the base plate 103, which have a tensile strength of at least 1300 MPa.

[0091] In particular, the base plate 103 of the receiving trough 101 has at least one further section with a tensile strength of less than 1300 MPa, wherein the further section comprises in particular the exposed regions 129 of the base plate 103, which have a tensile strength of less than 1300 MPa, in particular a tensile strength of 600 MPa to 1200 MPa.

[0092] The different tensile strengths within the base plate 103 are due to the manufacturing process, as the press-hardening of the receiving tray 101 takes place after the application of the soldered joints 117. This means that the pressing tool used for press-hardening presses on the contact areas 127 of the base plate 103 during the production of the receiving tray 101, and precisely does not press on the exposed areas 129 of the base plate 103. This results in the cooling from the hot-forming temperature and the tensile strength in the area of ​​the exposed areas 129 of the base plate 103 being lower than the tensile strength in the area of ​​the contact areas 127 of the base plate 103.

[0093] The battery housing 100 according to the first embodiment shown in Fig. 1 has excellent properties and can be manufactured easily and effectively.

[0094] Figure 2 shows a schematic representation of a battery housing according to a second embodiment.

[0095] The battery housing 100 according to the second embodiment shown in Fig. 2 differs from the battery housing 100 according to the first embodiment shown in Fig. 1 only in that, according to the second embodiment shown in Fig. 2, the corrugated bottom wall 111 is firmly attached to an inner side 131 of the bottom plate 103 of the receiving tray 101, said inner side facing the tray interior 107 of the receiving tray 101, by means of the corresponding soldered connections 117. For further details, please refer to the explanations for Fig. 1. This can provide underrun protection or puncture protection against stones for the battery cells and the cooling structure.

[0096] For reasons of clarity, a reduced number of reference symbols has been used in Fig. 2.

[0097] Figure 3 shows a schematic representation of a battery housing according to the second embodiment from above.

[0098] Here, an advantageous geometry of the corrugated bottom wall 111 or the cooling structure can now be seen, wherein the fluid guide channels 121 delimited by the bottom plate 103 of the receiving trough 101 and by the corrugated bottom wall 111 have a meandering shape in order to enable the introduced fluid to be distributed as evenly and as widely as possible.

[0099] Furthermore, Fig. 3 also shows that the outer wall 105 of the receiving trough 101 has four trough corners 133, with two trough corners 133 being connected by a side wall section 135 of the outer wall 105 of the receiving trough 101 and by the base plate 103 of the receiving trough 101. For forming reasons and / or to optimize usable space, the outer walls in the trough corners 133 can be positioned outwards or can be shaped more obliquely outwards than the more centrally located sections of the respective outer wall, as can be seen even more clearly in the plan view according to Figure 4.

[0100] It is emphasized that the outer wall 105 of the receiving tray 101 can also have more than four tray corners 133, in particular six, or eight tray corners 133, so that in this case a hexagonal or octagonal base plate 103 also results. In the latter cases, the tray corners 133 correspond in particular to the position or installation space requirement for vehicle wheel arches, but in stationary battery storage systems they can also result from other requirements, for example, better nestability, stackability, cooling connection accessibility, etc. For further details, reference is made to the explanations for Figures 1 and 2.

[0101] Figure 4 shows a schematic representation of a battery housing according to a third embodiment from below.

[0102] The battery housing 100 according to the third embodiment shown in Fig. 4 corresponds to the battery housing 100 according to the second embodiment shown in Fig. 3, except that according to Fig. 4 the corrugated bottom wall 111 is firmly fastened to a bottom plate outer side 113 of the bottom plate 103 of the receiving tray 101 facing away from the tray interior 107 of the receiving tray 101 by the corresponding soldered connections 117, which are not shown in Fig. 4, however.

[0103] Furthermore, the battery housing 100 of the fourth embodiment according to Fig. 4 has a plurality of crash frame profiles 137, which are arranged on at least two side wall sections 135 and are designed to absorb external forces acting on the side wall section 135 by deformation. The crash frame profiles 137 thus ensure structural reinforcement of the receiving tray 101. The crash frame profiles 137 are welded or screwed to the receiving tray 101, in particular to the outer wall 105. In particular, instead of a hollow crash frame profile 137, a sheet metal shell can also be used, which, together with the outer wall 105 of the receiving tray 101, forms a crash frame.

[0104] Figure 5 shows a schematic representation of a battery housing according to a fourth embodiment from below.

[0105] The battery housing 100 according to the embodiment shown in Fig. 5 corresponds to the second embodiment shown in Fig. 3, wherein the corrugated bottom wall 111 arranged on the bottom plate inner side 131 of the bottom plate 103 is concealed.

[0106] Fig. 5 shows that the base plate 103 of the receiving tray 101 has at least one shut-off bead 139, which is designed to limit the flow of material from the base plate 103, in particular from the area of ​​the soldered joints 117, during the thermoforming of the receiving tray 101. The shut-off bead 139 is designed, in particular, as a shut-off bead 139 or a surface notch surrounding the base plate 103. In particular, the shut-off bead 139 is arranged on the inside 131 of the base plate 103 or on both sides.

[0107] Figures 6A, 6B and 6C show a schematic representation of a method for manufacturing a battery enclosure according to an embodiment.

[0108] As shown in Fig. 6A, the method 200 includes providing 201 a one-piece, steel, flat receptacle precursor 101-1 having a bottom plate 103 and providing 203 a steel alloy corrugated bottom wall 111 having a plurality of abutment portions 115 and a plurality of extension portions 119.

[0109] According to Fig. 6A, the method then comprises the application 205 of a respective high-melting brazing alloy 117-1 to the base plate 103, in particular to corresponding contact regions 127 of the base plate 103. According to Fig. 6A, the respective high-melting brazing alloy 117-1 can alternatively or additionally also be applied to a contact section 115 of the corrugated base wall 111.

[0110] As shown in Fig. 6B, the method 200 further includes bringing the corrugated bottom wall 111 into contact 207 with the bottom plate 103 and then jointly heating 209 the corrugated bottom wall 111 and the receptacle precursor 101-1 to provide a plurality of integral solder joints 117 between the abutment portions 115 of the corrugated bottom wall 111 and the bottom plate 103.

[0111] As can be seen from Fig. 6C, the method 200 further comprises the thermoforming 211 of the receiving tray precursor 101-1 into a receiving tray 101 for receiving the majority of the battery cells or battery modules, wherein the receiving tray 101 has the base plate 103 and an outer wall 105 which is arranged circumferentially around the base plate 103, wherein the outer wall 105 delimits a tray interior 107 of the receiving tray 101, wherein on the outer wall 105 of the receiving tray 101 there is arranged a flange 109 which surrounds the outer wall 105 and extends at an angle to the outer wall 105 of the receiving tray 101.

[0112] As can be seen from Fig. 6C, the method 200 further comprises press hardening 213 the receiving tray 101 at least in sections to obtain a press-hardened receiving tray 101, wherein the press-hardened receiving tray 101 has at least in sections a tensile strength of at least 1300 MPa, such that the base plate 103 is press-hardened at least in the region of the soldered connections 117.

[0113] In particular, the hot forming 211, the at least partially press hardening 213, and the completion of the soldered joints 117 according to method step 207 can be carried out in a common method step and / or in a single pressing tool. For this purpose, a conventional pressing tool with two cooled tool halves and a tool forming surface adapted to the desired geometry of the receiving tray and, on one side, also to the actual geometry of the bottom wall is used (not shown).

[0114] In particular, the bringing 207 of the corrugated bottom wall 111 into contact with the bottom plate 103 may comprise the following further method step: pre-fixing the corrugated bottom wall 111 to the bottom plate 103 by spot welding.

[0115] In particular, the joint heating 209 of the corrugated bottom wall 111 and the receiving pan precursor 101-1 may comprise heating to at least a temperature corresponding to an austenitizing temperature Ac1 of the steel-formed receiving pan precursor 101-1, wherein in particular heating is carried out at a temperature of at least 850 °C.

[0116] In particular, the joint heating 209 cannot be carried out in a protective gas atmosphere and / or in a vacuum atmosphere.

[0117] It should be noted for all embodiments that when using the battery enclosure according to the invention, the bottom wall or base plate does not necessarily have to face the roadway and the flanges toward the vehicle interior. Rather, the receiving tray can also be installed rotated 180 degrees, so that the tray serves as a hood, and the flanges of the outer wall and the cover are positioned close to the roadway. In this case, the battery cooling system is at the maximum distance from the roadway and is particularly well protected against mechanical damage.

[0118] List of reference symbols

[0119] 100 Battery enclosure

[0120] 101 Receptacle

[0121] 101-1 Receptacle precursor

[0122] 103 Base plate

[0123] 105 Exterior wall

[0124] 107 Bathtub interior

[0125] 109 Flange

[0126] 111 Corrugated bottom wall

[0127] 113 Floor slab exterior

[0128] 115 Annex section

[0129] 117 Solder connection

[0130] 117-1 Brazing alloy

[0131] 119 Extension Section

[0132] 121 Fluid guide channel

[0133] 123 Curved transition area

[0134] 125 auxiliary line

[0135] 127 Contact area of ​​the base plate

[0136] 129 Exposed area of ​​the floor slab

[0137] 131 Inside of floor slab

[0138] 133 bathtub corners

[0139] 135 side wall section

[0140] 137 Crash frame profile

[0141] 139 shut-off bead

[0142] 200 Method for manufacturing a battery enclosure

[0143] 201 First process step: Providing a receiving tray precursor

[0144] 203 Second process step: Providing a corrugated bottom wall

[0145] 205 Third process step: Application of a high-melting brazing alloy

[0146] 207 Fourth process step: Bringing the corrugated floor wall into contact with the floor slab

[0147] 209 Fifth process step: Joint heating of the corrugated bottom wall and the receiving trough precursor 211 Sixth process step: Hot forming of the receiving trough precursor to a

[0148] Receptacle

[0149] 213 Seventh process step: Press hardening of the receiving tray at least in sections

Claims

PATENT CLAIMS 1. Battery housing (100) for accommodating a plurality of battery cells or battery modules, in particular in an electrically driven vehicle, comprising: a one-piece, hot-formed and press-hardened receiving tray (101) made of steel for accommodating the plurality of battery cells or battery modules, wherein the receiving tray (101) has a base plate (103) and an outer wall (105) which is arranged circumferentially around the base plate (103), wherein the outer wall (105) delimits a tray interior (107) of the receiving tray (101), wherein a flange (109) is arranged on the outer wall (105) of the receiving tray (101), which flange extends at an angle to the outer wall (105) of the receiving tray (101), wherein the receiving tray (101) has a tensile strength of at least 1300 MPa, at least in sections;and a corrugated bottom wall (111) made of a steel alloy, which has a plurality of contact sections (115), which are each integrally connected to the bottom plate (103) of the receiving tray (101) by a soldered connection (117), and wherein the corrugated bottom wall (111) has a plurality of extension sections (119) which are arranged at a distance from the bottom plate (103) of the receiving tray (101), wherein the plurality of extension sections (119) of the corrugated bottom wall (111) and the bottom plate (103) of the receiving tray (101) delimit a plurality of fluid guide channels (121) for guiding a fluid, wherein the soldered connections (117) are formed between the bottom plate (103) of the receiving tray (101) and the contact sections (115) of the corrugated bottom wall (111), a fluid-technical To provide sealing of the fluid guide channels (121); 2. Battery housing (100) according to claim 1, wherein an extension section (119) of the corrugated bottom wall (111) is arranged between each two adjacently arranged contact sections (115) of the corrugated bottom wall (111), and wherein the respective soldered connections (117) between the respective two adjacently arranged contact sections (115) of the corrugated bottom wall (111) and the bottom plate (103) of the receiving tray (101) are designed to provide a fluidic seal of the fluid guide channel (121), which is delimited by the respective extension section (119) of the corrugated bottom wall (111) and the bottom plate (103) of the receiving tray (101).

3. Battery housing (100) according to claim 1 or 2, wherein the bottom plate (103) of the receiving tray (101) projects beyond the corrugated bottom wall (111).

4. Battery housing (100) according to one of the preceding claims, wherein the outer wall (105) of the receiving trough (101) has a tensile strength of at least 1300 MPa at least in sections, in particular completely.

5. Battery housing (100) according to one of the preceding claims, wherein the base plate (103) of the receiving tray (101) has at least one section with a tensile strength of at least 1300 MPa and wherein the base plate (103) of the receiving tray (101) has at least one further section with a tensile strength of less than 1300 MPa, wherein the base plate (103) of the receiving tray (101) has in particular a plurality of contact regions (127) which bear against the contact sections (115) of the corrugated base wall (111), wherein the contact regions (127) have a tensile strength of at least 1300 MPa, and / or wherein the base plate (103) of the receiving tray (101) has in particular a plurality of exposed regions (129) which are spaced apart from the extension sections (119) of the corrugated base wall (111), wherein the exposed regions (129) have a tensile strength of 600 MPa to 1200 MPa.

6. Battery housing (100) according to one of the preceding claims, wherein the corrugated bottom wall (111) is arranged on a side facing the interior of the tub (107). The base plate inner side (131) of the base plate (103) of the receiving trough (101) is fastened by the soldered connections (117), or wherein the corrugated base wall (111) is fastened by the soldered connections (117) to a base plate outer side (113) of the base plate (103) of the receiving trough (101) facing away from the trough interior (107).

7. Battery housing (100) according to one of the preceding claims, wherein the corrugated bottom wall (111) of the receiving trough (101) is formed from a press-hardened steel, in particular from a press-hardened manganese-boron steel (MnB steel).

8. Battery housing (100) according to one of the preceding claims, wherein the receiving trough (101) and preferably the corrugated bottom wall (111) has a metallic coating which is applied on one side or both sides, wherein the metallic coating comprises in particular an aluminum, aluminum-silicon, aluminum-zinc, or aluminum-silicon-zinc alloy, and / or wherein the metallic coating has in particular a layer thickness between 10 μm and 50 μm, and / or wherein the metallic coating has in particular a basis weight between 60 mg / m 2 and 180 mg / m 2 has.

9. Battery housing (100) according to one of the preceding claims, wherein the corrugated bottom wall (111) is designed as a cold-formed bottom wall (111) and in particular has a metallic coating as scale protection.

10. Battery housing (100) according to one of the preceding claims, wherein the base plate (103) of the receiving tray (101) has at least one blocking bead (139) which is designed to limit a flow of material from the base plate (103), in particular from the region of the soldered connections (117), during the hot forming of the receiving tray (101).

11. Battery housing (100) according to one of the preceding claims, wherein the soldered connections (117) comprise a high-melting brazing alloy (117-1), which in particular comprises flux for reducing oxide formation.

12. Battery housing (100) according to one of the preceding claims, wherein the outer wall (105) of the receiving tray (101) has at least four tray corners (133), wherein two tray corners (133) are connected by a side wall section (135) of the outer wall (105) of the receiving tray (101) and by the base plate (103) of the receiving tray (101), wherein the battery housing (100) has a plurality of crash frame profiles (137) which are arranged on at least two side wall sections (135) and are designed to absorb forces acting on the side wall section (135) from the outside by means of a deformation.

13. A method (200) for producing a battery housing (100) for accommodating a plurality of battery cells or battery modules, in particular in an electrically driven vehicle, the method (200) comprising the following method steps: Providing (201) a one-piece, steel, receiving trough precursor (101-1) which has a base plate (103), Providing (203) a corrugated bottom wall (111) made of a steel alloy, which has a plurality of contact sections (115) and a plurality of extension sections (119), Applications (205) of a particularly high-melting brazing alloy (117-1) to a respective contact section (115) of the corrugated base wall (111) and / or to the base plate (103), Bringing (207) the corrugated bottom wall (111) into contact with the bottom plate (103), Joint heating (209) of the corrugated bottom wall (111) and the receptacle precursor (101-1) to provide a plurality of integral solder joints (117) between the contact sections (115) of the corrugated bottom wall (111) and the bottom plate (103), Thermoforming (211) of the receiving tray precursor (101-1) into a receiving tray (101) for receiving the majority of battery cells or battery modules, wherein the receiving tray (101) has the base plate (103) and an outer wall (105) which is arranged circumferentially around the base plate (103), wherein the outer wall (105) delimits a tray interior (107) of the receiving tray (101), wherein a flange (109) is arranged on the outer wall (105) of the receiving tray (101), which flange extends at an angle to the outer wall (105) of the receiving tray (101), and At least section-wise press-hardening (213) of the receiving trough (101) in order to obtain a press-hardened receiving trough (101), wherein the press-hardened receiving trough (101) has a tensile strength of at least 1300 MPa at least in section, such that the base plate (103) is press-hardened at least in the region of the soldered connections (117).

14. The method (200) according to claim 13, wherein the hot forming (211) and the at least partially press hardening (213) as well as the completion of the soldered connections (117) are carried out in a common method step and / or in a single pressing tool.

15. The method (200) according to claim 13 or 14, wherein bringing (207) the corrugated bottom wall (111) into contact with the bottom plate (103) comprises the following further method step: pre-fixing the corrugated bottom wall (111) to the bottom plate (103) by spot welding.

16. The method (200) according to any one of claims 13 to 15, wherein the joint heating (209) of the corrugated bottom wall (111) and the receiving trough precursor (101-1) comprises heating to at least one temperature which corresponds to an austenitizing temperature Ac1 of the steel-formed receiving trough precursor (101-1), wherein heating is carried out in particular at a temperature of at least 850 °C, and / or wherein the joint heating (209) is carried out in particular not in a protective gas atmosphere and / or not in a vacuum atmosphere.

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